1 /* 2 ** 2001-09-15 3 ** 4 ** The author disclaims copyright to this source code. In place of 5 ** a legal notice, here is a blessing: 6 ** 7 ** May you do good and not evil. 8 ** May you find forgiveness for yourself and forgive others. 9 ** May you share freely, never taking more than you give. 10 ** 11 ************************************************************************* 12 ** This header file defines the interface that the SQLite library 13 ** presents to client programs. If a C-function, structure, datatype, 14 ** or constant definition does not appear in this file, then it is 15 ** not a published API of SQLite, is subject to change without 16 ** notice, and should not be referenced by programs that use SQLite. 17 ** 18 ** Some of the definitions that are in this file are marked as 19 ** "experimental". Experimental interfaces are normally new 20 ** features recently added to SQLite. We do not anticipate changes 21 ** to experimental interfaces but reserve the right to make minor changes 22 ** if experience from use "in the wild" suggest such changes are prudent. 23 ** 24 ** The official C-language API documentation for SQLite is derived 25 ** from comments in this file. This file is the authoritative source 26 ** on how SQLite interfaces are supposed to operate. 27 ** 28 ** The name of this file under configuration management is "sqlite.h.in". 29 ** The makefile makes some minor changes to this file (such as inserting 30 ** the version number) and changes its name to "sqlite3.h" as 31 ** part of the build process. 32 */ 33 #ifndef SQLITE3_H 34 #define SQLITE3_H 35 #include <stdarg.h> /* Needed for the definition of va_list */ 36 37 /* 38 ** Make sure we can call this stuff from C++. 39 */ 40 #ifdef __cplusplus 41 extern "C" { 42 #endif 43 44 45 /* 46 ** Facilitate override of interface linkage and calling conventions. 47 ** Be aware that these macros may not be used within this particular 48 ** translation of the amalgamation and its associated header file. 49 ** 50 ** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the 51 ** compiler that the target identifier should have external linkage. 52 ** 53 ** The SQLITE_CDECL macro is used to set the calling convention for 54 ** public functions that accept a variable number of arguments. 55 ** 56 ** The SQLITE_APICALL macro is used to set the calling convention for 57 ** public functions that accept a fixed number of arguments. 58 ** 59 ** The SQLITE_STDCALL macro is no longer used and is now deprecated. 60 ** 61 ** The SQLITE_CALLBACK macro is used to set the calling convention for 62 ** function pointers. 63 ** 64 ** The SQLITE_SYSAPI macro is used to set the calling convention for 65 ** functions provided by the operating system. 66 ** 67 ** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and 68 ** SQLITE_SYSAPI macros are used only when building for environments 69 ** that require non-default calling conventions. 70 */ 71 #ifndef SQLITE_EXTERN 72 # define SQLITE_EXTERN extern 73 #endif 74 #ifndef SQLITE_API 75 # define SQLITE_API 76 #endif 77 #ifndef SQLITE_CDECL 78 # define SQLITE_CDECL 79 #endif 80 #ifndef SQLITE_APICALL 81 # define SQLITE_APICALL 82 #endif 83 #ifndef SQLITE_STDCALL 84 # define SQLITE_STDCALL SQLITE_APICALL 85 #endif 86 #ifndef SQLITE_CALLBACK 87 # define SQLITE_CALLBACK 88 #endif 89 #ifndef SQLITE_SYSAPI 90 # define SQLITE_SYSAPI 91 #endif 92 93 /* 94 ** These no-op macros are used in front of interfaces to mark those 95 ** interfaces as either deprecated or experimental. New applications 96 ** should not use deprecated interfaces - they are supported for backwards 97 ** compatibility only. Application writers should be aware that 98 ** experimental interfaces are subject to change in point releases. 99 ** 100 ** These macros used to resolve to various kinds of compiler magic that 101 ** would generate warning messages when they were used. But that 102 ** compiler magic ended up generating such a flurry of bug reports 103 ** that we have taken it all out and gone back to using simple 104 ** noop macros. 105 */ 106 #define SQLITE_DEPRECATED 107 #define SQLITE_EXPERIMENTAL 108 109 /* 110 ** Ensure these symbols were not defined by some previous header file. 111 */ 112 #ifdef SQLITE_VERSION 113 # undef SQLITE_VERSION 114 #endif 115 #ifdef SQLITE_VERSION_NUMBER 116 # undef SQLITE_VERSION_NUMBER 117 #endif 118 119 /* 120 ** CAPI3REF: Compile-Time Library Version Numbers 121 ** 122 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 123 ** evaluates to a string literal that is the SQLite version in the 124 ** format "X.Y.Z" where X is the major version number (always 3 for 125 ** SQLite3) and Y is the minor version number and Z is the release number.)^ 126 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 127 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 128 ** numbers used in [SQLITE_VERSION].)^ 129 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 130 ** be larger than the release from which it is derived. Either Y will 131 ** be held constant and Z will be incremented or else Y will be incremented 132 ** and Z will be reset to zero. 133 ** 134 ** Since [version 3.6.18] ([dateof:3.6.18]), 135 ** SQLite source code has been stored in the 136 ** <a href="http://www.fossil-scm.org/">Fossil configuration management 137 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 138 ** a string which identifies a particular check-in of SQLite 139 ** within its configuration management system. ^The SQLITE_SOURCE_ID 140 ** string contains the date and time of the check-in (UTC) and a SHA1 141 ** or SHA3-256 hash of the entire source tree. If the source code has 142 ** been edited in any way since it was last checked in, then the last 143 ** four hexadecimal digits of the hash may be modified. 144 ** 145 ** See also: [sqlite3_libversion()], 146 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 147 ** [sqlite_version()] and [sqlite_source_id()]. 148 */ 149 #define SQLITE_VERSION "3.39.0" 150 #define SQLITE_VERSION_NUMBER 3039000 151 #define SQLITE_SOURCE_ID "2022-06-25 14:57:57 14e166f40dbfa6e055543f8301525f2ca2e96a02a57269818b9e69e162e98918" 152 153 /* 154 ** CAPI3REF: Run-Time Library Version Numbers 155 ** KEYWORDS: sqlite3_version sqlite3_sourceid 156 ** 157 ** These interfaces provide the same information as the [SQLITE_VERSION], 158 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 159 ** but are associated with the library instead of the header file. ^(Cautious 160 ** programmers might include assert() statements in their application to 161 ** verify that values returned by these interfaces match the macros in 162 ** the header, and thus ensure that the application is 163 ** compiled with matching library and header files. 164 ** 165 ** <blockquote><pre> 166 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 167 ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 168 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 169 ** </pre></blockquote>)^ 170 ** 171 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 172 ** macro. ^The sqlite3_libversion() function returns a pointer to the 173 ** to the sqlite3_version[] string constant. The sqlite3_libversion() 174 ** function is provided for use in DLLs since DLL users usually do not have 175 ** direct access to string constants within the DLL. ^The 176 ** sqlite3_libversion_number() function returns an integer equal to 177 ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 178 ** a pointer to a string constant whose value is the same as the 179 ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 180 ** using an edited copy of [the amalgamation], then the last four characters 181 ** of the hash might be different from [SQLITE_SOURCE_ID].)^ 182 ** 183 ** See also: [sqlite_version()] and [sqlite_source_id()]. 184 */ 185 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 186 SQLITE_API const char *sqlite3_libversion(void); 187 SQLITE_API const char *sqlite3_sourceid(void); 188 SQLITE_API int sqlite3_libversion_number(void); 189 190 /* 191 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 192 ** 193 ** ^The sqlite3_compileoption_used() function returns 0 or 1 194 ** indicating whether the specified option was defined at 195 ** compile time. ^The SQLITE_ prefix may be omitted from the 196 ** option name passed to sqlite3_compileoption_used(). 197 ** 198 ** ^The sqlite3_compileoption_get() function allows iterating 199 ** over the list of options that were defined at compile time by 200 ** returning the N-th compile time option string. ^If N is out of range, 201 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 202 ** prefix is omitted from any strings returned by 203 ** sqlite3_compileoption_get(). 204 ** 205 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 206 ** and sqlite3_compileoption_get() may be omitted by specifying the 207 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 208 ** 209 ** See also: SQL functions [sqlite_compileoption_used()] and 210 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 211 */ 212 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 213 SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 214 SQLITE_API const char *sqlite3_compileoption_get(int N); 215 #else 216 # define sqlite3_compileoption_used(X) 0 217 # define sqlite3_compileoption_get(X) ((void*)0) 218 #endif 219 220 /* 221 ** CAPI3REF: Test To See If The Library Is Threadsafe 222 ** 223 ** ^The sqlite3_threadsafe() function returns zero if and only if 224 ** SQLite was compiled with mutexing code omitted due to the 225 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 226 ** 227 ** SQLite can be compiled with or without mutexes. When 228 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 229 ** are enabled and SQLite is threadsafe. When the 230 ** [SQLITE_THREADSAFE] macro is 0, 231 ** the mutexes are omitted. Without the mutexes, it is not safe 232 ** to use SQLite concurrently from more than one thread. 233 ** 234 ** Enabling mutexes incurs a measurable performance penalty. 235 ** So if speed is of utmost importance, it makes sense to disable 236 ** the mutexes. But for maximum safety, mutexes should be enabled. 237 ** ^The default behavior is for mutexes to be enabled. 238 ** 239 ** This interface can be used by an application to make sure that the 240 ** version of SQLite that it is linking against was compiled with 241 ** the desired setting of the [SQLITE_THREADSAFE] macro. 242 ** 243 ** This interface only reports on the compile-time mutex setting 244 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 245 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 246 ** can be fully or partially disabled using a call to [sqlite3_config()] 247 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 248 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 249 ** sqlite3_threadsafe() function shows only the compile-time setting of 250 ** thread safety, not any run-time changes to that setting made by 251 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 252 ** is unchanged by calls to sqlite3_config().)^ 253 ** 254 ** See the [threading mode] documentation for additional information. 255 */ 256 SQLITE_API int sqlite3_threadsafe(void); 257 258 /* 259 ** CAPI3REF: Database Connection Handle 260 ** KEYWORDS: {database connection} {database connections} 261 ** 262 ** Each open SQLite database is represented by a pointer to an instance of 263 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 264 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 265 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 266 ** and [sqlite3_close_v2()] are its destructors. There are many other 267 ** interfaces (such as 268 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 269 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 270 ** sqlite3 object. 271 */ 272 typedef struct sqlite3 sqlite3; 273 274 /* 275 ** CAPI3REF: 64-Bit Integer Types 276 ** KEYWORDS: sqlite_int64 sqlite_uint64 277 ** 278 ** Because there is no cross-platform way to specify 64-bit integer types 279 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 280 ** 281 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 282 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 283 ** compatibility only. 284 ** 285 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 286 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 287 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 288 ** between 0 and +18446744073709551615 inclusive. 289 */ 290 #ifdef SQLITE_INT64_TYPE 291 typedef SQLITE_INT64_TYPE sqlite_int64; 292 # ifdef SQLITE_UINT64_TYPE 293 typedef SQLITE_UINT64_TYPE sqlite_uint64; 294 # else 295 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 296 # endif 297 #elif defined(_MSC_VER) || defined(__BORLANDC__) 298 typedef __int64 sqlite_int64; 299 typedef unsigned __int64 sqlite_uint64; 300 #else 301 typedef long long int sqlite_int64; 302 typedef unsigned long long int sqlite_uint64; 303 #endif 304 typedef sqlite_int64 sqlite3_int64; 305 typedef sqlite_uint64 sqlite3_uint64; 306 307 /* 308 ** If compiling for a processor that lacks floating point support, 309 ** substitute integer for floating-point. 310 */ 311 #ifdef SQLITE_OMIT_FLOATING_POINT 312 # define double sqlite3_int64 313 #endif 314 315 /* 316 ** CAPI3REF: Closing A Database Connection 317 ** DESTRUCTOR: sqlite3 318 ** 319 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 320 ** for the [sqlite3] object. 321 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 322 ** the [sqlite3] object is successfully destroyed and all associated 323 ** resources are deallocated. 324 ** 325 ** Ideally, applications should [sqlite3_finalize | finalize] all 326 ** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and 327 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 328 ** with the [sqlite3] object prior to attempting to close the object. 329 ** ^If the database connection is associated with unfinalized prepared 330 ** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then 331 ** sqlite3_close() will leave the database connection open and return 332 ** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared 333 ** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups, 334 ** it returns [SQLITE_OK] regardless, but instead of deallocating the database 335 ** connection immediately, it marks the database connection as an unusable 336 ** "zombie" and makes arrangements to automatically deallocate the database 337 ** connection after all prepared statements are finalized, all BLOB handles 338 ** are closed, and all backups have finished. The sqlite3_close_v2() interface 339 ** is intended for use with host languages that are garbage collected, and 340 ** where the order in which destructors are called is arbitrary. 341 ** 342 ** ^If an [sqlite3] object is destroyed while a transaction is open, 343 ** the transaction is automatically rolled back. 344 ** 345 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 346 ** must be either a NULL 347 ** pointer or an [sqlite3] object pointer obtained 348 ** from [sqlite3_open()], [sqlite3_open16()], or 349 ** [sqlite3_open_v2()], and not previously closed. 350 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 351 ** argument is a harmless no-op. 352 */ 353 SQLITE_API int sqlite3_close(sqlite3*); 354 SQLITE_API int sqlite3_close_v2(sqlite3*); 355 356 /* 357 ** The type for a callback function. 358 ** This is legacy and deprecated. It is included for historical 359 ** compatibility and is not documented. 360 */ 361 typedef int (*sqlite3_callback)(void*,int,char**, char**); 362 363 /* 364 ** CAPI3REF: One-Step Query Execution Interface 365 ** METHOD: sqlite3 366 ** 367 ** The sqlite3_exec() interface is a convenience wrapper around 368 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 369 ** that allows an application to run multiple statements of SQL 370 ** without having to use a lot of C code. 371 ** 372 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 373 ** semicolon-separate SQL statements passed into its 2nd argument, 374 ** in the context of the [database connection] passed in as its 1st 375 ** argument. ^If the callback function of the 3rd argument to 376 ** sqlite3_exec() is not NULL, then it is invoked for each result row 377 ** coming out of the evaluated SQL statements. ^The 4th argument to 378 ** sqlite3_exec() is relayed through to the 1st argument of each 379 ** callback invocation. ^If the callback pointer to sqlite3_exec() 380 ** is NULL, then no callback is ever invoked and result rows are 381 ** ignored. 382 ** 383 ** ^If an error occurs while evaluating the SQL statements passed into 384 ** sqlite3_exec(), then execution of the current statement stops and 385 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 386 ** is not NULL then any error message is written into memory obtained 387 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 388 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 389 ** on error message strings returned through the 5th parameter of 390 ** sqlite3_exec() after the error message string is no longer needed. 391 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 392 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 393 ** NULL before returning. 394 ** 395 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 396 ** routine returns SQLITE_ABORT without invoking the callback again and 397 ** without running any subsequent SQL statements. 398 ** 399 ** ^The 2nd argument to the sqlite3_exec() callback function is the 400 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 401 ** callback is an array of pointers to strings obtained as if from 402 ** [sqlite3_column_text()], one for each column. ^If an element of a 403 ** result row is NULL then the corresponding string pointer for the 404 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 405 ** sqlite3_exec() callback is an array of pointers to strings where each 406 ** entry represents the name of corresponding result column as obtained 407 ** from [sqlite3_column_name()]. 408 ** 409 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 410 ** to an empty string, or a pointer that contains only whitespace and/or 411 ** SQL comments, then no SQL statements are evaluated and the database 412 ** is not changed. 413 ** 414 ** Restrictions: 415 ** 416 ** <ul> 417 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 418 ** is a valid and open [database connection]. 419 ** <li> The application must not close the [database connection] specified by 420 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 421 ** <li> The application must not modify the SQL statement text passed into 422 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 423 ** </ul> 424 */ 425 SQLITE_API int sqlite3_exec( 426 sqlite3*, /* An open database */ 427 const char *sql, /* SQL to be evaluated */ 428 int (*callback)(void*,int,char**,char**), /* Callback function */ 429 void *, /* 1st argument to callback */ 430 char **errmsg /* Error msg written here */ 431 ); 432 433 /* 434 ** CAPI3REF: Result Codes 435 ** KEYWORDS: {result code definitions} 436 ** 437 ** Many SQLite functions return an integer result code from the set shown 438 ** here in order to indicate success or failure. 439 ** 440 ** New error codes may be added in future versions of SQLite. 441 ** 442 ** See also: [extended result code definitions] 443 */ 444 #define SQLITE_OK 0 /* Successful result */ 445 /* beginning-of-error-codes */ 446 #define SQLITE_ERROR 1 /* Generic error */ 447 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 448 #define SQLITE_PERM 3 /* Access permission denied */ 449 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 450 #define SQLITE_BUSY 5 /* The database file is locked */ 451 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 452 #define SQLITE_NOMEM 7 /* A malloc() failed */ 453 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 454 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 455 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 456 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 457 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 458 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 459 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 460 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 461 #define SQLITE_EMPTY 16 /* Internal use only */ 462 #define SQLITE_SCHEMA 17 /* The database schema changed */ 463 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 464 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 465 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 466 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 467 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 468 #define SQLITE_AUTH 23 /* Authorization denied */ 469 #define SQLITE_FORMAT 24 /* Not used */ 470 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 471 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 472 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 473 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 474 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 475 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 476 /* end-of-error-codes */ 477 478 /* 479 ** CAPI3REF: Extended Result Codes 480 ** KEYWORDS: {extended result code definitions} 481 ** 482 ** In its default configuration, SQLite API routines return one of 30 integer 483 ** [result codes]. However, experience has shown that many of 484 ** these result codes are too coarse-grained. They do not provide as 485 ** much information about problems as programmers might like. In an effort to 486 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 487 ** and later) include 488 ** support for additional result codes that provide more detailed information 489 ** about errors. These [extended result codes] are enabled or disabled 490 ** on a per database connection basis using the 491 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 492 ** the most recent error can be obtained using 493 ** [sqlite3_extended_errcode()]. 494 */ 495 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 496 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 497 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 498 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 499 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 500 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 501 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 502 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 503 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 504 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 505 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 506 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 507 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 508 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 509 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 510 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 511 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 512 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 513 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 514 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 515 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 516 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 517 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 518 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 519 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 520 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 521 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 522 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 523 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 524 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 525 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 526 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 527 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 528 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 529 #define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8)) 530 #define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8)) 531 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 532 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 533 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 534 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 535 #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8)) 536 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 537 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 538 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 539 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 540 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 541 #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) 542 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 543 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 544 #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8)) 545 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 546 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 547 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 548 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 549 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 550 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 551 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 552 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 553 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 554 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 555 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 556 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 557 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 558 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 559 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 560 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 561 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 562 #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) 563 #define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8)) 564 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 565 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 566 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 567 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 568 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 569 #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */ 570 571 /* 572 ** CAPI3REF: Flags For File Open Operations 573 ** 574 ** These bit values are intended for use in the 575 ** 3rd parameter to the [sqlite3_open_v2()] interface and 576 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 577 ** 578 ** Only those flags marked as "Ok for sqlite3_open_v2()" may be 579 ** used as the third argument to the [sqlite3_open_v2()] interface. 580 ** The other flags have historically been ignored by sqlite3_open_v2(), 581 ** though future versions of SQLite might change so that an error is 582 ** raised if any of the disallowed bits are passed into sqlite3_open_v2(). 583 ** Applications should not depend on the historical behavior. 584 ** 585 ** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into 586 ** [sqlite3_open_v2()] does *not* cause the underlying database file 587 ** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into 588 ** [sqlite3_open_v2()] has historically be a no-op and might become an 589 ** error in future versions of SQLite. 590 */ 591 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 592 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 593 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 594 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 595 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 596 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 597 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 598 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 599 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 600 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 601 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 602 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 603 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 604 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 605 #define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */ 606 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 607 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 608 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 609 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 610 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 611 #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ 612 #define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */ 613 614 /* Reserved: 0x00F00000 */ 615 /* Legacy compatibility: */ 616 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 617 618 619 /* 620 ** CAPI3REF: Device Characteristics 621 ** 622 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 623 ** object returns an integer which is a vector of these 624 ** bit values expressing I/O characteristics of the mass storage 625 ** device that holds the file that the [sqlite3_io_methods] 626 ** refers to. 627 ** 628 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 629 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 630 ** mean that writes of blocks that are nnn bytes in size and 631 ** are aligned to an address which is an integer multiple of 632 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 633 ** that when data is appended to a file, the data is appended 634 ** first then the size of the file is extended, never the other 635 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 636 ** information is written to disk in the same order as calls 637 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 638 ** after reboot following a crash or power loss, the only bytes in a 639 ** file that were written at the application level might have changed 640 ** and that adjacent bytes, even bytes within the same sector are 641 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 642 ** flag indicates that a file cannot be deleted when open. The 643 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 644 ** read-only media and cannot be changed even by processes with 645 ** elevated privileges. 646 ** 647 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 648 ** filesystem supports doing multiple write operations atomically when those 649 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 650 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 651 */ 652 #define SQLITE_IOCAP_ATOMIC 0x00000001 653 #define SQLITE_IOCAP_ATOMIC512 0x00000002 654 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 655 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 656 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 657 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 658 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 659 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 660 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 661 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 662 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 663 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 664 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 665 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 666 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 667 668 /* 669 ** CAPI3REF: File Locking Levels 670 ** 671 ** SQLite uses one of these integer values as the second 672 ** argument to calls it makes to the xLock() and xUnlock() methods 673 ** of an [sqlite3_io_methods] object. 674 */ 675 #define SQLITE_LOCK_NONE 0 676 #define SQLITE_LOCK_SHARED 1 677 #define SQLITE_LOCK_RESERVED 2 678 #define SQLITE_LOCK_PENDING 3 679 #define SQLITE_LOCK_EXCLUSIVE 4 680 681 /* 682 ** CAPI3REF: Synchronization Type Flags 683 ** 684 ** When SQLite invokes the xSync() method of an 685 ** [sqlite3_io_methods] object it uses a combination of 686 ** these integer values as the second argument. 687 ** 688 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 689 ** sync operation only needs to flush data to mass storage. Inode 690 ** information need not be flushed. If the lower four bits of the flag 691 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 692 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 693 ** to use Mac OS X style fullsync instead of fsync(). 694 ** 695 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 696 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 697 ** settings. The [synchronous pragma] determines when calls to the 698 ** xSync VFS method occur and applies uniformly across all platforms. 699 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 700 ** energetic or rigorous or forceful the sync operations are and 701 ** only make a difference on Mac OSX for the default SQLite code. 702 ** (Third-party VFS implementations might also make the distinction 703 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 704 ** operating systems natively supported by SQLite, only Mac OSX 705 ** cares about the difference.) 706 */ 707 #define SQLITE_SYNC_NORMAL 0x00002 708 #define SQLITE_SYNC_FULL 0x00003 709 #define SQLITE_SYNC_DATAONLY 0x00010 710 711 /* 712 ** CAPI3REF: OS Interface Open File Handle 713 ** 714 ** An [sqlite3_file] object represents an open file in the 715 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 716 ** implementations will 717 ** want to subclass this object by appending additional fields 718 ** for their own use. The pMethods entry is a pointer to an 719 ** [sqlite3_io_methods] object that defines methods for performing 720 ** I/O operations on the open file. 721 */ 722 typedef struct sqlite3_file sqlite3_file; 723 struct sqlite3_file { 724 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 725 }; 726 727 /* 728 ** CAPI3REF: OS Interface File Virtual Methods Object 729 ** 730 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 731 ** [sqlite3_file] object (or, more commonly, a subclass of the 732 ** [sqlite3_file] object) with a pointer to an instance of this object. 733 ** This object defines the methods used to perform various operations 734 ** against the open file represented by the [sqlite3_file] object. 735 ** 736 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 737 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 738 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 739 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 740 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 741 ** to NULL. 742 ** 743 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 744 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 745 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 746 ** flag may be ORed in to indicate that only the data of the file 747 ** and not its inode needs to be synced. 748 ** 749 ** The integer values to xLock() and xUnlock() are one of 750 ** <ul> 751 ** <li> [SQLITE_LOCK_NONE], 752 ** <li> [SQLITE_LOCK_SHARED], 753 ** <li> [SQLITE_LOCK_RESERVED], 754 ** <li> [SQLITE_LOCK_PENDING], or 755 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 756 ** </ul> 757 ** xLock() increases the lock. xUnlock() decreases the lock. 758 ** The xCheckReservedLock() method checks whether any database connection, 759 ** either in this process or in some other process, is holding a RESERVED, 760 ** PENDING, or EXCLUSIVE lock on the file. It returns true 761 ** if such a lock exists and false otherwise. 762 ** 763 ** The xFileControl() method is a generic interface that allows custom 764 ** VFS implementations to directly control an open file using the 765 ** [sqlite3_file_control()] interface. The second "op" argument is an 766 ** integer opcode. The third argument is a generic pointer intended to 767 ** point to a structure that may contain arguments or space in which to 768 ** write return values. Potential uses for xFileControl() might be 769 ** functions to enable blocking locks with timeouts, to change the 770 ** locking strategy (for example to use dot-file locks), to inquire 771 ** about the status of a lock, or to break stale locks. The SQLite 772 ** core reserves all opcodes less than 100 for its own use. 773 ** A [file control opcodes | list of opcodes] less than 100 is available. 774 ** Applications that define a custom xFileControl method should use opcodes 775 ** greater than 100 to avoid conflicts. VFS implementations should 776 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 777 ** recognize. 778 ** 779 ** The xSectorSize() method returns the sector size of the 780 ** device that underlies the file. The sector size is the 781 ** minimum write that can be performed without disturbing 782 ** other bytes in the file. The xDeviceCharacteristics() 783 ** method returns a bit vector describing behaviors of the 784 ** underlying device: 785 ** 786 ** <ul> 787 ** <li> [SQLITE_IOCAP_ATOMIC] 788 ** <li> [SQLITE_IOCAP_ATOMIC512] 789 ** <li> [SQLITE_IOCAP_ATOMIC1K] 790 ** <li> [SQLITE_IOCAP_ATOMIC2K] 791 ** <li> [SQLITE_IOCAP_ATOMIC4K] 792 ** <li> [SQLITE_IOCAP_ATOMIC8K] 793 ** <li> [SQLITE_IOCAP_ATOMIC16K] 794 ** <li> [SQLITE_IOCAP_ATOMIC32K] 795 ** <li> [SQLITE_IOCAP_ATOMIC64K] 796 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 797 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 798 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 799 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 800 ** <li> [SQLITE_IOCAP_IMMUTABLE] 801 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 802 ** </ul> 803 ** 804 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 805 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 806 ** mean that writes of blocks that are nnn bytes in size and 807 ** are aligned to an address which is an integer multiple of 808 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 809 ** that when data is appended to a file, the data is appended 810 ** first then the size of the file is extended, never the other 811 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 812 ** information is written to disk in the same order as calls 813 ** to xWrite(). 814 ** 815 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 816 ** in the unread portions of the buffer with zeros. A VFS that 817 ** fails to zero-fill short reads might seem to work. However, 818 ** failure to zero-fill short reads will eventually lead to 819 ** database corruption. 820 */ 821 typedef struct sqlite3_io_methods sqlite3_io_methods; 822 struct sqlite3_io_methods { 823 int iVersion; 824 int (*xClose)(sqlite3_file*); 825 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 826 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 827 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 828 int (*xSync)(sqlite3_file*, int flags); 829 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 830 int (*xLock)(sqlite3_file*, int); 831 int (*xUnlock)(sqlite3_file*, int); 832 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 833 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 834 int (*xSectorSize)(sqlite3_file*); 835 int (*xDeviceCharacteristics)(sqlite3_file*); 836 /* Methods above are valid for version 1 */ 837 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 838 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 839 void (*xShmBarrier)(sqlite3_file*); 840 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 841 /* Methods above are valid for version 2 */ 842 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 843 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 844 /* Methods above are valid for version 3 */ 845 /* Additional methods may be added in future releases */ 846 }; 847 848 /* 849 ** CAPI3REF: Standard File Control Opcodes 850 ** KEYWORDS: {file control opcodes} {file control opcode} 851 ** 852 ** These integer constants are opcodes for the xFileControl method 853 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 854 ** interface. 855 ** 856 ** <ul> 857 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 858 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 859 ** opcode causes the xFileControl method to write the current state of 860 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 861 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 862 ** into an integer that the pArg argument points to. This capability 863 ** is used during testing and is only available when the SQLITE_TEST 864 ** compile-time option is used. 865 ** 866 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 867 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 868 ** layer a hint of how large the database file will grow to be during the 869 ** current transaction. This hint is not guaranteed to be accurate but it 870 ** is often close. The underlying VFS might choose to preallocate database 871 ** file space based on this hint in order to help writes to the database 872 ** file run faster. 873 ** 874 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 875 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 876 ** implements [sqlite3_deserialize()] to set an upper bound on the size 877 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 878 ** If the integer pointed to is negative, then it is filled in with the 879 ** current limit. Otherwise the limit is set to the larger of the value 880 ** of the integer pointed to and the current database size. The integer 881 ** pointed to is set to the new limit. 882 ** 883 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 884 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 885 ** extends and truncates the database file in chunks of a size specified 886 ** by the user. The fourth argument to [sqlite3_file_control()] should 887 ** point to an integer (type int) containing the new chunk-size to use 888 ** for the nominated database. Allocating database file space in large 889 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 890 ** improve performance on some systems. 891 ** 892 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 893 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 894 ** to the [sqlite3_file] object associated with a particular database 895 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 896 ** 897 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 898 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 899 ** to the [sqlite3_file] object associated with the journal file (either 900 ** the [rollback journal] or the [write-ahead log]) for a particular database 901 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 902 ** 903 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 904 ** No longer in use. 905 ** 906 ** <li>[[SQLITE_FCNTL_SYNC]] 907 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 908 ** sent to the VFS immediately before the xSync method is invoked on a 909 ** database file descriptor. Or, if the xSync method is not invoked 910 ** because the user has configured SQLite with 911 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 912 ** of the xSync method. In most cases, the pointer argument passed with 913 ** this file-control is NULL. However, if the database file is being synced 914 ** as part of a multi-database commit, the argument points to a nul-terminated 915 ** string containing the transactions super-journal file name. VFSes that 916 ** do not need this signal should silently ignore this opcode. Applications 917 ** should not call [sqlite3_file_control()] with this opcode as doing so may 918 ** disrupt the operation of the specialized VFSes that do require it. 919 ** 920 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 921 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 922 ** and sent to the VFS after a transaction has been committed immediately 923 ** but before the database is unlocked. VFSes that do not need this signal 924 ** should silently ignore this opcode. Applications should not call 925 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 926 ** operation of the specialized VFSes that do require it. 927 ** 928 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 929 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 930 ** retry counts and intervals for certain disk I/O operations for the 931 ** windows [VFS] in order to provide robustness in the presence of 932 ** anti-virus programs. By default, the windows VFS will retry file read, 933 ** file write, and file delete operations up to 10 times, with a delay 934 ** of 25 milliseconds before the first retry and with the delay increasing 935 ** by an additional 25 milliseconds with each subsequent retry. This 936 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 937 ** to be adjusted. The values are changed for all database connections 938 ** within the same process. The argument is a pointer to an array of two 939 ** integers where the first integer is the new retry count and the second 940 ** integer is the delay. If either integer is negative, then the setting 941 ** is not changed but instead the prior value of that setting is written 942 ** into the array entry, allowing the current retry settings to be 943 ** interrogated. The zDbName parameter is ignored. 944 ** 945 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 946 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 947 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 948 ** write ahead log ([WAL file]) and shared memory 949 ** files used for transaction control 950 ** are automatically deleted when the latest connection to the database 951 ** closes. Setting persistent WAL mode causes those files to persist after 952 ** close. Persisting the files is useful when other processes that do not 953 ** have write permission on the directory containing the database file want 954 ** to read the database file, as the WAL and shared memory files must exist 955 ** in order for the database to be readable. The fourth parameter to 956 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 957 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 958 ** WAL mode. If the integer is -1, then it is overwritten with the current 959 ** WAL persistence setting. 960 ** 961 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 962 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 963 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 964 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 965 ** xDeviceCharacteristics methods. The fourth parameter to 966 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 967 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 968 ** mode. If the integer is -1, then it is overwritten with the current 969 ** zero-damage mode setting. 970 ** 971 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 972 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 973 ** a write transaction to indicate that, unless it is rolled back for some 974 ** reason, the entire database file will be overwritten by the current 975 ** transaction. This is used by VACUUM operations. 976 ** 977 ** <li>[[SQLITE_FCNTL_VFSNAME]] 978 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 979 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 980 ** final bottom-level VFS are written into memory obtained from 981 ** [sqlite3_malloc()] and the result is stored in the char* variable 982 ** that the fourth parameter of [sqlite3_file_control()] points to. 983 ** The caller is responsible for freeing the memory when done. As with 984 ** all file-control actions, there is no guarantee that this will actually 985 ** do anything. Callers should initialize the char* variable to a NULL 986 ** pointer in case this file-control is not implemented. This file-control 987 ** is intended for diagnostic use only. 988 ** 989 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 990 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 991 ** [VFSes] currently in use. ^(The argument X in 992 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 993 ** of type "[sqlite3_vfs] **". This opcodes will set *X 994 ** to a pointer to the top-level VFS.)^ 995 ** ^When there are multiple VFS shims in the stack, this opcode finds the 996 ** upper-most shim only. 997 ** 998 ** <li>[[SQLITE_FCNTL_PRAGMA]] 999 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 1000 ** file control is sent to the open [sqlite3_file] object corresponding 1001 ** to the database file to which the pragma statement refers. ^The argument 1002 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 1003 ** pointers to strings (char**) in which the second element of the array 1004 ** is the name of the pragma and the third element is the argument to the 1005 ** pragma or NULL if the pragma has no argument. ^The handler for an 1006 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 1007 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 1008 ** or the equivalent and that string will become the result of the pragma or 1009 ** the error message if the pragma fails. ^If the 1010 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 1011 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 1012 ** file control returns [SQLITE_OK], then the parser assumes that the 1013 ** VFS has handled the PRAGMA itself and the parser generates a no-op 1014 ** prepared statement if result string is NULL, or that returns a copy 1015 ** of the result string if the string is non-NULL. 1016 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 1017 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 1018 ** that the VFS encountered an error while handling the [PRAGMA] and the 1019 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 1020 ** file control occurs at the beginning of pragma statement analysis and so 1021 ** it is able to override built-in [PRAGMA] statements. 1022 ** 1023 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 1024 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 1025 ** file-control may be invoked by SQLite on the database file handle 1026 ** shortly after it is opened in order to provide a custom VFS with access 1027 ** to the connection's busy-handler callback. The argument is of type (void**) 1028 ** - an array of two (void *) values. The first (void *) actually points 1029 ** to a function of type (int (*)(void *)). In order to invoke the connection's 1030 ** busy-handler, this function should be invoked with the second (void *) in 1031 ** the array as the only argument. If it returns non-zero, then the operation 1032 ** should be retried. If it returns zero, the custom VFS should abandon the 1033 ** current operation. 1034 ** 1035 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 1036 ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 1037 ** to have SQLite generate a 1038 ** temporary filename using the same algorithm that is followed to generate 1039 ** temporary filenames for TEMP tables and other internal uses. The 1040 ** argument should be a char** which will be filled with the filename 1041 ** written into memory obtained from [sqlite3_malloc()]. The caller should 1042 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 1043 ** 1044 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1045 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1046 ** maximum number of bytes that will be used for memory-mapped I/O. 1047 ** The argument is a pointer to a value of type sqlite3_int64 that 1048 ** is an advisory maximum number of bytes in the file to memory map. The 1049 ** pointer is overwritten with the old value. The limit is not changed if 1050 ** the value originally pointed to is negative, and so the current limit 1051 ** can be queried by passing in a pointer to a negative number. This 1052 ** file-control is used internally to implement [PRAGMA mmap_size]. 1053 ** 1054 ** <li>[[SQLITE_FCNTL_TRACE]] 1055 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1056 ** to the VFS about what the higher layers of the SQLite stack are doing. 1057 ** This file control is used by some VFS activity tracing [shims]. 1058 ** The argument is a zero-terminated string. Higher layers in the 1059 ** SQLite stack may generate instances of this file control if 1060 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1061 ** 1062 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1063 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1064 ** pointer to an integer and it writes a boolean into that integer depending 1065 ** on whether or not the file has been renamed, moved, or deleted since it 1066 ** was first opened. 1067 ** 1068 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1069 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1070 ** underlying native file handle associated with a file handle. This file 1071 ** control interprets its argument as a pointer to a native file handle and 1072 ** writes the resulting value there. 1073 ** 1074 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1075 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1076 ** opcode causes the xFileControl method to swap the file handle with the one 1077 ** pointed to by the pArg argument. This capability is used during testing 1078 ** and only needs to be supported when SQLITE_TEST is defined. 1079 ** 1080 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1081 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1082 ** be advantageous to block on the next WAL lock if the lock is not immediately 1083 ** available. The WAL subsystem issues this signal during rare 1084 ** circumstances in order to fix a problem with priority inversion. 1085 ** Applications should <em>not</em> use this file-control. 1086 ** 1087 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 1088 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1089 ** VFS should return SQLITE_NOTFOUND for this opcode. 1090 ** 1091 ** <li>[[SQLITE_FCNTL_RBU]] 1092 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1093 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1094 ** this opcode. 1095 ** 1096 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1097 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1098 ** the file descriptor is placed in "batch write mode", which 1099 ** means all subsequent write operations will be deferred and done 1100 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1101 ** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1102 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1103 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1104 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1105 ** no VFS interface calls on the same [sqlite3_file] file descriptor 1106 ** except for calls to the xWrite method and the xFileControl method 1107 ** with [SQLITE_FCNTL_SIZE_HINT]. 1108 ** 1109 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1110 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1111 ** operations since the previous successful call to 1112 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1113 ** This file control returns [SQLITE_OK] if and only if the writes were 1114 ** all performed successfully and have been committed to persistent storage. 1115 ** ^Regardless of whether or not it is successful, this file control takes 1116 ** the file descriptor out of batch write mode so that all subsequent 1117 ** write operations are independent. 1118 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1119 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1120 ** 1121 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1122 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1123 ** operations since the previous successful call to 1124 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1125 ** ^This file control takes the file descriptor out of batch write mode 1126 ** so that all subsequent write operations are independent. 1127 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1128 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1129 ** 1130 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1131 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS 1132 ** to block for up to M milliseconds before failing when attempting to 1133 ** obtain a file lock using the xLock or xShmLock methods of the VFS. 1134 ** The parameter is a pointer to a 32-bit signed integer that contains 1135 ** the value that M is to be set to. Before returning, the 32-bit signed 1136 ** integer is overwritten with the previous value of M. 1137 ** 1138 ** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1139 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1140 ** a database file. The argument is a pointer to a 32-bit unsigned integer. 1141 ** The "data version" for the pager is written into the pointer. The 1142 ** "data version" changes whenever any change occurs to the corresponding 1143 ** database file, either through SQL statements on the same database 1144 ** connection or through transactions committed by separate database 1145 ** connections possibly in other processes. The [sqlite3_total_changes()] 1146 ** interface can be used to find if any database on the connection has changed, 1147 ** but that interface responds to changes on TEMP as well as MAIN and does 1148 ** not provide a mechanism to detect changes to MAIN only. Also, the 1149 ** [sqlite3_total_changes()] interface responds to internal changes only and 1150 ** omits changes made by other database connections. The 1151 ** [PRAGMA data_version] command provides a mechanism to detect changes to 1152 ** a single attached database that occur due to other database connections, 1153 ** but omits changes implemented by the database connection on which it is 1154 ** called. This file control is the only mechanism to detect changes that 1155 ** happen either internally or externally and that are associated with 1156 ** a particular attached database. 1157 ** 1158 ** <li>[[SQLITE_FCNTL_CKPT_START]] 1159 ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint 1160 ** in wal mode before the client starts to copy pages from the wal 1161 ** file to the database file. 1162 ** 1163 ** <li>[[SQLITE_FCNTL_CKPT_DONE]] 1164 ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint 1165 ** in wal mode after the client has finished copying pages from the wal 1166 ** file to the database file, but before the *-shm file is updated to 1167 ** record the fact that the pages have been checkpointed. 1168 ** </ul> 1169 ** 1170 ** <li>[[SQLITE_FCNTL_EXTERNAL_READER]] 1171 ** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect 1172 ** whether or not there is a database client in another process with a wal-mode 1173 ** transaction open on the database or not. It is only available on unix.The 1174 ** (void*) argument passed with this file-control should be a pointer to a 1175 ** value of type (int). The integer value is set to 1 if the database is a wal 1176 ** mode database and there exists at least one client in another process that 1177 ** currently has an SQL transaction open on the database. It is set to 0 if 1178 ** the database is not a wal-mode db, or if there is no such connection in any 1179 ** other process. This opcode cannot be used to detect transactions opened 1180 ** by clients within the current process, only within other processes. 1181 ** </ul> 1182 ** 1183 ** <li>[[SQLITE_FCNTL_CKSM_FILE]] 1184 ** Used by the cksmvfs VFS module only. 1185 ** </ul> 1186 */ 1187 #define SQLITE_FCNTL_LOCKSTATE 1 1188 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1189 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1190 #define SQLITE_FCNTL_LAST_ERRNO 4 1191 #define SQLITE_FCNTL_SIZE_HINT 5 1192 #define SQLITE_FCNTL_CHUNK_SIZE 6 1193 #define SQLITE_FCNTL_FILE_POINTER 7 1194 #define SQLITE_FCNTL_SYNC_OMITTED 8 1195 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1196 #define SQLITE_FCNTL_PERSIST_WAL 10 1197 #define SQLITE_FCNTL_OVERWRITE 11 1198 #define SQLITE_FCNTL_VFSNAME 12 1199 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1200 #define SQLITE_FCNTL_PRAGMA 14 1201 #define SQLITE_FCNTL_BUSYHANDLER 15 1202 #define SQLITE_FCNTL_TEMPFILENAME 16 1203 #define SQLITE_FCNTL_MMAP_SIZE 18 1204 #define SQLITE_FCNTL_TRACE 19 1205 #define SQLITE_FCNTL_HAS_MOVED 20 1206 #define SQLITE_FCNTL_SYNC 21 1207 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1208 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1209 #define SQLITE_FCNTL_WAL_BLOCK 24 1210 #define SQLITE_FCNTL_ZIPVFS 25 1211 #define SQLITE_FCNTL_RBU 26 1212 #define SQLITE_FCNTL_VFS_POINTER 27 1213 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1214 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1215 #define SQLITE_FCNTL_PDB 30 1216 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1217 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1218 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1219 #define SQLITE_FCNTL_LOCK_TIMEOUT 34 1220 #define SQLITE_FCNTL_DATA_VERSION 35 1221 #define SQLITE_FCNTL_SIZE_LIMIT 36 1222 #define SQLITE_FCNTL_CKPT_DONE 37 1223 #define SQLITE_FCNTL_RESERVE_BYTES 38 1224 #define SQLITE_FCNTL_CKPT_START 39 1225 #define SQLITE_FCNTL_EXTERNAL_READER 40 1226 #define SQLITE_FCNTL_CKSM_FILE 41 1227 1228 /* deprecated names */ 1229 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1230 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1231 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1232 1233 1234 /* 1235 ** CAPI3REF: Mutex Handle 1236 ** 1237 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1238 ** abstract type for a mutex object. The SQLite core never looks 1239 ** at the internal representation of an [sqlite3_mutex]. It only 1240 ** deals with pointers to the [sqlite3_mutex] object. 1241 ** 1242 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1243 */ 1244 typedef struct sqlite3_mutex sqlite3_mutex; 1245 1246 /* 1247 ** CAPI3REF: Loadable Extension Thunk 1248 ** 1249 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1250 ** the third parameter to entry points of [loadable extensions]. This 1251 ** structure must be typedefed in order to work around compiler warnings 1252 ** on some platforms. 1253 */ 1254 typedef struct sqlite3_api_routines sqlite3_api_routines; 1255 1256 /* 1257 ** CAPI3REF: OS Interface Object 1258 ** 1259 ** An instance of the sqlite3_vfs object defines the interface between 1260 ** the SQLite core and the underlying operating system. The "vfs" 1261 ** in the name of the object stands for "virtual file system". See 1262 ** the [VFS | VFS documentation] for further information. 1263 ** 1264 ** The VFS interface is sometimes extended by adding new methods onto 1265 ** the end. Each time such an extension occurs, the iVersion field 1266 ** is incremented. The iVersion value started out as 1 in 1267 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1268 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1269 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1270 ** may be appended to the sqlite3_vfs object and the iVersion value 1271 ** may increase again in future versions of SQLite. 1272 ** Note that due to an oversight, the structure 1273 ** of the sqlite3_vfs object changed in the transition from 1274 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1275 ** and yet the iVersion field was not increased. 1276 ** 1277 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1278 ** structure used by this VFS. mxPathname is the maximum length of 1279 ** a pathname in this VFS. 1280 ** 1281 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1282 ** the pNext pointer. The [sqlite3_vfs_register()] 1283 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1284 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1285 ** searches the list. Neither the application code nor the VFS 1286 ** implementation should use the pNext pointer. 1287 ** 1288 ** The pNext field is the only field in the sqlite3_vfs 1289 ** structure that SQLite will ever modify. SQLite will only access 1290 ** or modify this field while holding a particular static mutex. 1291 ** The application should never modify anything within the sqlite3_vfs 1292 ** object once the object has been registered. 1293 ** 1294 ** The zName field holds the name of the VFS module. The name must 1295 ** be unique across all VFS modules. 1296 ** 1297 ** [[sqlite3_vfs.xOpen]] 1298 ** ^SQLite guarantees that the zFilename parameter to xOpen 1299 ** is either a NULL pointer or string obtained 1300 ** from xFullPathname() with an optional suffix added. 1301 ** ^If a suffix is added to the zFilename parameter, it will 1302 ** consist of a single "-" character followed by no more than 1303 ** 11 alphanumeric and/or "-" characters. 1304 ** ^SQLite further guarantees that 1305 ** the string will be valid and unchanged until xClose() is 1306 ** called. Because of the previous sentence, 1307 ** the [sqlite3_file] can safely store a pointer to the 1308 ** filename if it needs to remember the filename for some reason. 1309 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1310 ** must invent its own temporary name for the file. ^Whenever the 1311 ** xFilename parameter is NULL it will also be the case that the 1312 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1313 ** 1314 ** The flags argument to xOpen() includes all bits set in 1315 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1316 ** or [sqlite3_open16()] is used, then flags includes at least 1317 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1318 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1319 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1320 ** 1321 ** ^(SQLite will also add one of the following flags to the xOpen() 1322 ** call, depending on the object being opened: 1323 ** 1324 ** <ul> 1325 ** <li> [SQLITE_OPEN_MAIN_DB] 1326 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1327 ** <li> [SQLITE_OPEN_TEMP_DB] 1328 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1329 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1330 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1331 ** <li> [SQLITE_OPEN_SUPER_JOURNAL] 1332 ** <li> [SQLITE_OPEN_WAL] 1333 ** </ul>)^ 1334 ** 1335 ** The file I/O implementation can use the object type flags to 1336 ** change the way it deals with files. For example, an application 1337 ** that does not care about crash recovery or rollback might make 1338 ** the open of a journal file a no-op. Writes to this journal would 1339 ** also be no-ops, and any attempt to read the journal would return 1340 ** SQLITE_IOERR. Or the implementation might recognize that a database 1341 ** file will be doing page-aligned sector reads and writes in a random 1342 ** order and set up its I/O subsystem accordingly. 1343 ** 1344 ** SQLite might also add one of the following flags to the xOpen method: 1345 ** 1346 ** <ul> 1347 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1348 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1349 ** </ul> 1350 ** 1351 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1352 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1353 ** will be set for TEMP databases and their journals, transient 1354 ** databases, and subjournals. 1355 ** 1356 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1357 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1358 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1359 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1360 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1361 ** be created, and that it is an error if it already exists. 1362 ** It is <i>not</i> used to indicate the file should be opened 1363 ** for exclusive access. 1364 ** 1365 ** ^At least szOsFile bytes of memory are allocated by SQLite 1366 ** to hold the [sqlite3_file] structure passed as the third 1367 ** argument to xOpen. The xOpen method does not have to 1368 ** allocate the structure; it should just fill it in. Note that 1369 ** the xOpen method must set the sqlite3_file.pMethods to either 1370 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1371 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1372 ** element will be valid after xOpen returns regardless of the success 1373 ** or failure of the xOpen call. 1374 ** 1375 ** [[sqlite3_vfs.xAccess]] 1376 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1377 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1378 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1379 ** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1380 ** flag is never actually used and is not implemented in the built-in 1381 ** VFSes of SQLite. The file is named by the second argument and can be a 1382 ** directory. The xAccess method returns [SQLITE_OK] on success or some 1383 ** non-zero error code if there is an I/O error or if the name of 1384 ** the file given in the second argument is illegal. If SQLITE_OK 1385 ** is returned, then non-zero or zero is written into *pResOut to indicate 1386 ** whether or not the file is accessible. 1387 ** 1388 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1389 ** output buffer xFullPathname. The exact size of the output buffer 1390 ** is also passed as a parameter to both methods. If the output buffer 1391 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1392 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1393 ** to prevent this by setting mxPathname to a sufficiently large value. 1394 ** 1395 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1396 ** interfaces are not strictly a part of the filesystem, but they are 1397 ** included in the VFS structure for completeness. 1398 ** The xRandomness() function attempts to return nBytes bytes 1399 ** of good-quality randomness into zOut. The return value is 1400 ** the actual number of bytes of randomness obtained. 1401 ** The xSleep() method causes the calling thread to sleep for at 1402 ** least the number of microseconds given. ^The xCurrentTime() 1403 ** method returns a Julian Day Number for the current date and time as 1404 ** a floating point value. 1405 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1406 ** Day Number multiplied by 86400000 (the number of milliseconds in 1407 ** a 24-hour day). 1408 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1409 ** date and time if that method is available (if iVersion is 2 or 1410 ** greater and the function pointer is not NULL) and will fall back 1411 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1412 ** 1413 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1414 ** are not used by the SQLite core. These optional interfaces are provided 1415 ** by some VFSes to facilitate testing of the VFS code. By overriding 1416 ** system calls with functions under its control, a test program can 1417 ** simulate faults and error conditions that would otherwise be difficult 1418 ** or impossible to induce. The set of system calls that can be overridden 1419 ** varies from one VFS to another, and from one version of the same VFS to the 1420 ** next. Applications that use these interfaces must be prepared for any 1421 ** or all of these interfaces to be NULL or for their behavior to change 1422 ** from one release to the next. Applications must not attempt to access 1423 ** any of these methods if the iVersion of the VFS is less than 3. 1424 */ 1425 typedef struct sqlite3_vfs sqlite3_vfs; 1426 typedef void (*sqlite3_syscall_ptr)(void); 1427 struct sqlite3_vfs { 1428 int iVersion; /* Structure version number (currently 3) */ 1429 int szOsFile; /* Size of subclassed sqlite3_file */ 1430 int mxPathname; /* Maximum file pathname length */ 1431 sqlite3_vfs *pNext; /* Next registered VFS */ 1432 const char *zName; /* Name of this virtual file system */ 1433 void *pAppData; /* Pointer to application-specific data */ 1434 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1435 int flags, int *pOutFlags); 1436 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1437 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1438 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1439 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1440 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1441 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1442 void (*xDlClose)(sqlite3_vfs*, void*); 1443 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1444 int (*xSleep)(sqlite3_vfs*, int microseconds); 1445 int (*xCurrentTime)(sqlite3_vfs*, double*); 1446 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1447 /* 1448 ** The methods above are in version 1 of the sqlite_vfs object 1449 ** definition. Those that follow are added in version 2 or later 1450 */ 1451 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1452 /* 1453 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1454 ** Those below are for version 3 and greater. 1455 */ 1456 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1457 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1458 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1459 /* 1460 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1461 ** New fields may be appended in future versions. The iVersion 1462 ** value will increment whenever this happens. 1463 */ 1464 }; 1465 1466 /* 1467 ** CAPI3REF: Flags for the xAccess VFS method 1468 ** 1469 ** These integer constants can be used as the third parameter to 1470 ** the xAccess method of an [sqlite3_vfs] object. They determine 1471 ** what kind of permissions the xAccess method is looking for. 1472 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1473 ** simply checks whether the file exists. 1474 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1475 ** checks whether the named directory is both readable and writable 1476 ** (in other words, if files can be added, removed, and renamed within 1477 ** the directory). 1478 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1479 ** [temp_store_directory pragma], though this could change in a future 1480 ** release of SQLite. 1481 ** With SQLITE_ACCESS_READ, the xAccess method 1482 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1483 ** currently unused, though it might be used in a future release of 1484 ** SQLite. 1485 */ 1486 #define SQLITE_ACCESS_EXISTS 0 1487 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1488 #define SQLITE_ACCESS_READ 2 /* Unused */ 1489 1490 /* 1491 ** CAPI3REF: Flags for the xShmLock VFS method 1492 ** 1493 ** These integer constants define the various locking operations 1494 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1495 ** following are the only legal combinations of flags to the 1496 ** xShmLock method: 1497 ** 1498 ** <ul> 1499 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1500 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1501 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1502 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1503 ** </ul> 1504 ** 1505 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1506 ** was given on the corresponding lock. 1507 ** 1508 ** The xShmLock method can transition between unlocked and SHARED or 1509 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1510 ** and EXCLUSIVE. 1511 */ 1512 #define SQLITE_SHM_UNLOCK 1 1513 #define SQLITE_SHM_LOCK 2 1514 #define SQLITE_SHM_SHARED 4 1515 #define SQLITE_SHM_EXCLUSIVE 8 1516 1517 /* 1518 ** CAPI3REF: Maximum xShmLock index 1519 ** 1520 ** The xShmLock method on [sqlite3_io_methods] may use values 1521 ** between 0 and this upper bound as its "offset" argument. 1522 ** The SQLite core will never attempt to acquire or release a 1523 ** lock outside of this range 1524 */ 1525 #define SQLITE_SHM_NLOCK 8 1526 1527 1528 /* 1529 ** CAPI3REF: Initialize The SQLite Library 1530 ** 1531 ** ^The sqlite3_initialize() routine initializes the 1532 ** SQLite library. ^The sqlite3_shutdown() routine 1533 ** deallocates any resources that were allocated by sqlite3_initialize(). 1534 ** These routines are designed to aid in process initialization and 1535 ** shutdown on embedded systems. Workstation applications using 1536 ** SQLite normally do not need to invoke either of these routines. 1537 ** 1538 ** A call to sqlite3_initialize() is an "effective" call if it is 1539 ** the first time sqlite3_initialize() is invoked during the lifetime of 1540 ** the process, or if it is the first time sqlite3_initialize() is invoked 1541 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1542 ** of sqlite3_initialize() does any initialization. All other calls 1543 ** are harmless no-ops.)^ 1544 ** 1545 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1546 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1547 ** an effective call to sqlite3_shutdown() does any deinitialization. 1548 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1549 ** 1550 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1551 ** is not. The sqlite3_shutdown() interface must only be called from a 1552 ** single thread. All open [database connections] must be closed and all 1553 ** other SQLite resources must be deallocated prior to invoking 1554 ** sqlite3_shutdown(). 1555 ** 1556 ** Among other things, ^sqlite3_initialize() will invoke 1557 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1558 ** will invoke sqlite3_os_end(). 1559 ** 1560 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1561 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1562 ** the library (perhaps it is unable to allocate a needed resource such 1563 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1564 ** 1565 ** ^The sqlite3_initialize() routine is called internally by many other 1566 ** SQLite interfaces so that an application usually does not need to 1567 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1568 ** calls sqlite3_initialize() so the SQLite library will be automatically 1569 ** initialized when [sqlite3_open()] is called if it has not be initialized 1570 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1571 ** compile-time option, then the automatic calls to sqlite3_initialize() 1572 ** are omitted and the application must call sqlite3_initialize() directly 1573 ** prior to using any other SQLite interface. For maximum portability, 1574 ** it is recommended that applications always invoke sqlite3_initialize() 1575 ** directly prior to using any other SQLite interface. Future releases 1576 ** of SQLite may require this. In other words, the behavior exhibited 1577 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1578 ** default behavior in some future release of SQLite. 1579 ** 1580 ** The sqlite3_os_init() routine does operating-system specific 1581 ** initialization of the SQLite library. The sqlite3_os_end() 1582 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1583 ** performed by these routines include allocation or deallocation 1584 ** of static resources, initialization of global variables, 1585 ** setting up a default [sqlite3_vfs] module, or setting up 1586 ** a default configuration using [sqlite3_config()]. 1587 ** 1588 ** The application should never invoke either sqlite3_os_init() 1589 ** or sqlite3_os_end() directly. The application should only invoke 1590 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1591 ** interface is called automatically by sqlite3_initialize() and 1592 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1593 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1594 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1595 ** When [custom builds | built for other platforms] 1596 ** (using the [SQLITE_OS_OTHER=1] compile-time 1597 ** option) the application must supply a suitable implementation for 1598 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1599 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1600 ** must return [SQLITE_OK] on success and some other [error code] upon 1601 ** failure. 1602 */ 1603 SQLITE_API int sqlite3_initialize(void); 1604 SQLITE_API int sqlite3_shutdown(void); 1605 SQLITE_API int sqlite3_os_init(void); 1606 SQLITE_API int sqlite3_os_end(void); 1607 1608 /* 1609 ** CAPI3REF: Configuring The SQLite Library 1610 ** 1611 ** The sqlite3_config() interface is used to make global configuration 1612 ** changes to SQLite in order to tune SQLite to the specific needs of 1613 ** the application. The default configuration is recommended for most 1614 ** applications and so this routine is usually not necessary. It is 1615 ** provided to support rare applications with unusual needs. 1616 ** 1617 ** <b>The sqlite3_config() interface is not threadsafe. The application 1618 ** must ensure that no other SQLite interfaces are invoked by other 1619 ** threads while sqlite3_config() is running.</b> 1620 ** 1621 ** The sqlite3_config() interface 1622 ** may only be invoked prior to library initialization using 1623 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1624 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1625 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1626 ** Note, however, that ^sqlite3_config() can be called as part of the 1627 ** implementation of an application-defined [sqlite3_os_init()]. 1628 ** 1629 ** The first argument to sqlite3_config() is an integer 1630 ** [configuration option] that determines 1631 ** what property of SQLite is to be configured. Subsequent arguments 1632 ** vary depending on the [configuration option] 1633 ** in the first argument. 1634 ** 1635 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1636 ** ^If the option is unknown or SQLite is unable to set the option 1637 ** then this routine returns a non-zero [error code]. 1638 */ 1639 SQLITE_API int sqlite3_config(int, ...); 1640 1641 /* 1642 ** CAPI3REF: Configure database connections 1643 ** METHOD: sqlite3 1644 ** 1645 ** The sqlite3_db_config() interface is used to make configuration 1646 ** changes to a [database connection]. The interface is similar to 1647 ** [sqlite3_config()] except that the changes apply to a single 1648 ** [database connection] (specified in the first argument). 1649 ** 1650 ** The second argument to sqlite3_db_config(D,V,...) is the 1651 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1652 ** that indicates what aspect of the [database connection] is being configured. 1653 ** Subsequent arguments vary depending on the configuration verb. 1654 ** 1655 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1656 ** the call is considered successful. 1657 */ 1658 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1659 1660 /* 1661 ** CAPI3REF: Memory Allocation Routines 1662 ** 1663 ** An instance of this object defines the interface between SQLite 1664 ** and low-level memory allocation routines. 1665 ** 1666 ** This object is used in only one place in the SQLite interface. 1667 ** A pointer to an instance of this object is the argument to 1668 ** [sqlite3_config()] when the configuration option is 1669 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1670 ** By creating an instance of this object 1671 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1672 ** during configuration, an application can specify an alternative 1673 ** memory allocation subsystem for SQLite to use for all of its 1674 ** dynamic memory needs. 1675 ** 1676 ** Note that SQLite comes with several [built-in memory allocators] 1677 ** that are perfectly adequate for the overwhelming majority of applications 1678 ** and that this object is only useful to a tiny minority of applications 1679 ** with specialized memory allocation requirements. This object is 1680 ** also used during testing of SQLite in order to specify an alternative 1681 ** memory allocator that simulates memory out-of-memory conditions in 1682 ** order to verify that SQLite recovers gracefully from such 1683 ** conditions. 1684 ** 1685 ** The xMalloc, xRealloc, and xFree methods must work like the 1686 ** malloc(), realloc() and free() functions from the standard C library. 1687 ** ^SQLite guarantees that the second argument to 1688 ** xRealloc is always a value returned by a prior call to xRoundup. 1689 ** 1690 ** xSize should return the allocated size of a memory allocation 1691 ** previously obtained from xMalloc or xRealloc. The allocated size 1692 ** is always at least as big as the requested size but may be larger. 1693 ** 1694 ** The xRoundup method returns what would be the allocated size of 1695 ** a memory allocation given a particular requested size. Most memory 1696 ** allocators round up memory allocations at least to the next multiple 1697 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1698 ** Every memory allocation request coming in through [sqlite3_malloc()] 1699 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1700 ** that causes the corresponding memory allocation to fail. 1701 ** 1702 ** The xInit method initializes the memory allocator. For example, 1703 ** it might allocate any required mutexes or initialize internal data 1704 ** structures. The xShutdown method is invoked (indirectly) by 1705 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1706 ** by xInit. The pAppData pointer is used as the only parameter to 1707 ** xInit and xShutdown. 1708 ** 1709 ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes 1710 ** the xInit method, so the xInit method need not be threadsafe. The 1711 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1712 ** not need to be threadsafe either. For all other methods, SQLite 1713 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1714 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1715 ** it is by default) and so the methods are automatically serialized. 1716 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1717 ** methods must be threadsafe or else make their own arrangements for 1718 ** serialization. 1719 ** 1720 ** SQLite will never invoke xInit() more than once without an intervening 1721 ** call to xShutdown(). 1722 */ 1723 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1724 struct sqlite3_mem_methods { 1725 void *(*xMalloc)(int); /* Memory allocation function */ 1726 void (*xFree)(void*); /* Free a prior allocation */ 1727 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1728 int (*xSize)(void*); /* Return the size of an allocation */ 1729 int (*xRoundup)(int); /* Round up request size to allocation size */ 1730 int (*xInit)(void*); /* Initialize the memory allocator */ 1731 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1732 void *pAppData; /* Argument to xInit() and xShutdown() */ 1733 }; 1734 1735 /* 1736 ** CAPI3REF: Configuration Options 1737 ** KEYWORDS: {configuration option} 1738 ** 1739 ** These constants are the available integer configuration options that 1740 ** can be passed as the first argument to the [sqlite3_config()] interface. 1741 ** 1742 ** New configuration options may be added in future releases of SQLite. 1743 ** Existing configuration options might be discontinued. Applications 1744 ** should check the return code from [sqlite3_config()] to make sure that 1745 ** the call worked. The [sqlite3_config()] interface will return a 1746 ** non-zero [error code] if a discontinued or unsupported configuration option 1747 ** is invoked. 1748 ** 1749 ** <dl> 1750 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1751 ** <dd>There are no arguments to this option. ^This option sets the 1752 ** [threading mode] to Single-thread. In other words, it disables 1753 ** all mutexing and puts SQLite into a mode where it can only be used 1754 ** by a single thread. ^If SQLite is compiled with 1755 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1756 ** it is not possible to change the [threading mode] from its default 1757 ** value of Single-thread and so [sqlite3_config()] will return 1758 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1759 ** configuration option.</dd> 1760 ** 1761 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1762 ** <dd>There are no arguments to this option. ^This option sets the 1763 ** [threading mode] to Multi-thread. In other words, it disables 1764 ** mutexing on [database connection] and [prepared statement] objects. 1765 ** The application is responsible for serializing access to 1766 ** [database connections] and [prepared statements]. But other mutexes 1767 ** are enabled so that SQLite will be safe to use in a multi-threaded 1768 ** environment as long as no two threads attempt to use the same 1769 ** [database connection] at the same time. ^If SQLite is compiled with 1770 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1771 ** it is not possible to set the Multi-thread [threading mode] and 1772 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1773 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1774 ** 1775 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1776 ** <dd>There are no arguments to this option. ^This option sets the 1777 ** [threading mode] to Serialized. In other words, this option enables 1778 ** all mutexes including the recursive 1779 ** mutexes on [database connection] and [prepared statement] objects. 1780 ** In this mode (which is the default when SQLite is compiled with 1781 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1782 ** to [database connections] and [prepared statements] so that the 1783 ** application is free to use the same [database connection] or the 1784 ** same [prepared statement] in different threads at the same time. 1785 ** ^If SQLite is compiled with 1786 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1787 ** it is not possible to set the Serialized [threading mode] and 1788 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1789 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1790 ** 1791 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1792 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1793 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1794 ** The argument specifies 1795 ** alternative low-level memory allocation routines to be used in place of 1796 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1797 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1798 ** before the [sqlite3_config()] call returns.</dd> 1799 ** 1800 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1801 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1802 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1803 ** The [sqlite3_mem_methods] 1804 ** structure is filled with the currently defined memory allocation routines.)^ 1805 ** This option can be used to overload the default memory allocation 1806 ** routines with a wrapper that simulations memory allocation failure or 1807 ** tracks memory usage, for example. </dd> 1808 ** 1809 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1810 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1811 ** type int, interpreted as a boolean, which if true provides a hint to 1812 ** SQLite that it should avoid large memory allocations if possible. 1813 ** SQLite will run faster if it is free to make large memory allocations, 1814 ** but some application might prefer to run slower in exchange for 1815 ** guarantees about memory fragmentation that are possible if large 1816 ** allocations are avoided. This hint is normally off. 1817 ** </dd> 1818 ** 1819 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1820 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1821 ** interpreted as a boolean, which enables or disables the collection of 1822 ** memory allocation statistics. ^(When memory allocation statistics are 1823 ** disabled, the following SQLite interfaces become non-operational: 1824 ** <ul> 1825 ** <li> [sqlite3_hard_heap_limit64()] 1826 ** <li> [sqlite3_memory_used()] 1827 ** <li> [sqlite3_memory_highwater()] 1828 ** <li> [sqlite3_soft_heap_limit64()] 1829 ** <li> [sqlite3_status64()] 1830 ** </ul>)^ 1831 ** ^Memory allocation statistics are enabled by default unless SQLite is 1832 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1833 ** allocation statistics are disabled by default. 1834 ** </dd> 1835 ** 1836 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1837 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1838 ** </dd> 1839 ** 1840 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1841 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1842 ** that SQLite can use for the database page cache with the default page 1843 ** cache implementation. 1844 ** This configuration option is a no-op if an application-defined page 1845 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1846 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1847 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1848 ** and the number of cache lines (N). 1849 ** The sz argument should be the size of the largest database page 1850 ** (a power of two between 512 and 65536) plus some extra bytes for each 1851 ** page header. ^The number of extra bytes needed by the page header 1852 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1853 ** ^It is harmless, apart from the wasted memory, 1854 ** for the sz parameter to be larger than necessary. The pMem 1855 ** argument must be either a NULL pointer or a pointer to an 8-byte 1856 ** aligned block of memory of at least sz*N bytes, otherwise 1857 ** subsequent behavior is undefined. 1858 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1859 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1860 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1861 ** is exhausted. 1862 ** ^If pMem is NULL and N is non-zero, then each database connection 1863 ** does an initial bulk allocation for page cache memory 1864 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1865 ** of -1024*N bytes if N is negative, . ^If additional 1866 ** page cache memory is needed beyond what is provided by the initial 1867 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1868 ** additional cache line. </dd> 1869 ** 1870 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1871 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1872 ** that SQLite will use for all of its dynamic memory allocation needs 1873 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1874 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1875 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1876 ** [SQLITE_ERROR] if invoked otherwise. 1877 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1878 ** An 8-byte aligned pointer to the memory, 1879 ** the number of bytes in the memory buffer, and the minimum allocation size. 1880 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1881 ** to using its default memory allocator (the system malloc() implementation), 1882 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1883 ** memory pointer is not NULL then the alternative memory 1884 ** allocator is engaged to handle all of SQLites memory allocation needs. 1885 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1886 ** boundary or subsequent behavior of SQLite will be undefined. 1887 ** The minimum allocation size is capped at 2**12. Reasonable values 1888 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1889 ** 1890 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1891 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1892 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1893 ** The argument specifies alternative low-level mutex routines to be used 1894 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1895 ** the content of the [sqlite3_mutex_methods] structure before the call to 1896 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1897 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1898 ** the entire mutexing subsystem is omitted from the build and hence calls to 1899 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1900 ** return [SQLITE_ERROR].</dd> 1901 ** 1902 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1903 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1904 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1905 ** [sqlite3_mutex_methods] 1906 ** structure is filled with the currently defined mutex routines.)^ 1907 ** This option can be used to overload the default mutex allocation 1908 ** routines with a wrapper used to track mutex usage for performance 1909 ** profiling or testing, for example. ^If SQLite is compiled with 1910 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1911 ** the entire mutexing subsystem is omitted from the build and hence calls to 1912 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1913 ** return [SQLITE_ERROR].</dd> 1914 ** 1915 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1916 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1917 ** the default size of lookaside memory on each [database connection]. 1918 ** The first argument is the 1919 ** size of each lookaside buffer slot and the second is the number of 1920 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1921 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1922 ** option to [sqlite3_db_config()] can be used to change the lookaside 1923 ** configuration on individual connections.)^ </dd> 1924 ** 1925 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1926 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1927 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1928 ** the interface to a custom page cache implementation.)^ 1929 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1930 ** 1931 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1932 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1933 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1934 ** the current page cache implementation into that object.)^ </dd> 1935 ** 1936 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1937 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1938 ** global [error log]. 1939 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1940 ** function with a call signature of void(*)(void*,int,const char*), 1941 ** and a pointer to void. ^If the function pointer is not NULL, it is 1942 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1943 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1944 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1945 ** passed through as the first parameter to the application-defined logger 1946 ** function whenever that function is invoked. ^The second parameter to 1947 ** the logger function is a copy of the first parameter to the corresponding 1948 ** [sqlite3_log()] call and is intended to be a [result code] or an 1949 ** [extended result code]. ^The third parameter passed to the logger is 1950 ** log message after formatting via [sqlite3_snprintf()]. 1951 ** The SQLite logging interface is not reentrant; the logger function 1952 ** supplied by the application must not invoke any SQLite interface. 1953 ** In a multi-threaded application, the application-defined logger 1954 ** function must be threadsafe. </dd> 1955 ** 1956 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1957 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1958 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1959 ** then URI handling is globally disabled.)^ ^If URI handling is globally 1960 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1961 ** [sqlite3_open16()] or 1962 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1963 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1964 ** connection is opened. ^If it is globally disabled, filenames are 1965 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1966 ** database connection is opened. ^(By default, URI handling is globally 1967 ** disabled. The default value may be changed by compiling with the 1968 ** [SQLITE_USE_URI] symbol defined.)^ 1969 ** 1970 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1971 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1972 ** argument which is interpreted as a boolean in order to enable or disable 1973 ** the use of covering indices for full table scans in the query optimizer. 1974 ** ^The default setting is determined 1975 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1976 ** if that compile-time option is omitted. 1977 ** The ability to disable the use of covering indices for full table scans 1978 ** is because some incorrectly coded legacy applications might malfunction 1979 ** when the optimization is enabled. Providing the ability to 1980 ** disable the optimization allows the older, buggy application code to work 1981 ** without change even with newer versions of SQLite. 1982 ** 1983 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1984 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1985 ** <dd> These options are obsolete and should not be used by new code. 1986 ** They are retained for backwards compatibility but are now no-ops. 1987 ** </dd> 1988 ** 1989 ** [[SQLITE_CONFIG_SQLLOG]] 1990 ** <dt>SQLITE_CONFIG_SQLLOG 1991 ** <dd>This option is only available if sqlite is compiled with the 1992 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1993 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1994 ** The second should be of type (void*). The callback is invoked by the library 1995 ** in three separate circumstances, identified by the value passed as the 1996 ** fourth parameter. If the fourth parameter is 0, then the database connection 1997 ** passed as the second argument has just been opened. The third argument 1998 ** points to a buffer containing the name of the main database file. If the 1999 ** fourth parameter is 1, then the SQL statement that the third parameter 2000 ** points to has just been executed. Or, if the fourth parameter is 2, then 2001 ** the connection being passed as the second parameter is being closed. The 2002 ** third parameter is passed NULL In this case. An example of using this 2003 ** configuration option can be seen in the "test_sqllog.c" source file in 2004 ** the canonical SQLite source tree.</dd> 2005 ** 2006 ** [[SQLITE_CONFIG_MMAP_SIZE]] 2007 ** <dt>SQLITE_CONFIG_MMAP_SIZE 2008 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 2009 ** that are the default mmap size limit (the default setting for 2010 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 2011 ** ^The default setting can be overridden by each database connection using 2012 ** either the [PRAGMA mmap_size] command, or by using the 2013 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 2014 ** will be silently truncated if necessary so that it does not exceed the 2015 ** compile-time maximum mmap size set by the 2016 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 2017 ** ^If either argument to this option is negative, then that argument is 2018 ** changed to its compile-time default. 2019 ** 2020 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 2021 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 2022 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 2023 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 2024 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 2025 ** that specifies the maximum size of the created heap. 2026 ** 2027 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 2028 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 2029 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 2030 ** is a pointer to an integer and writes into that integer the number of extra 2031 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 2032 ** The amount of extra space required can change depending on the compiler, 2033 ** target platform, and SQLite version. 2034 ** 2035 ** [[SQLITE_CONFIG_PMASZ]] 2036 ** <dt>SQLITE_CONFIG_PMASZ 2037 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 2038 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 2039 ** sorter to that integer. The default minimum PMA Size is set by the 2040 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 2041 ** to help with sort operations when multithreaded sorting 2042 ** is enabled (using the [PRAGMA threads] command) and the amount of content 2043 ** to be sorted exceeds the page size times the minimum of the 2044 ** [PRAGMA cache_size] setting and this value. 2045 ** 2046 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 2047 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 2048 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 2049 ** becomes the [statement journal] spill-to-disk threshold. 2050 ** [Statement journals] are held in memory until their size (in bytes) 2051 ** exceeds this threshold, at which point they are written to disk. 2052 ** Or if the threshold is -1, statement journals are always held 2053 ** exclusively in memory. 2054 ** Since many statement journals never become large, setting the spill 2055 ** threshold to a value such as 64KiB can greatly reduce the amount of 2056 ** I/O required to support statement rollback. 2057 ** The default value for this setting is controlled by the 2058 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 2059 ** 2060 ** [[SQLITE_CONFIG_SORTERREF_SIZE]] 2061 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE 2062 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 2063 ** of type (int) - the new value of the sorter-reference size threshold. 2064 ** Usually, when SQLite uses an external sort to order records according 2065 ** to an ORDER BY clause, all fields required by the caller are present in the 2066 ** sorted records. However, if SQLite determines based on the declared type 2067 ** of a table column that its values are likely to be very large - larger 2068 ** than the configured sorter-reference size threshold - then a reference 2069 ** is stored in each sorted record and the required column values loaded 2070 ** from the database as records are returned in sorted order. The default 2071 ** value for this option is to never use this optimization. Specifying a 2072 ** negative value for this option restores the default behaviour. 2073 ** This option is only available if SQLite is compiled with the 2074 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 2075 ** 2076 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 2077 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 2078 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 2079 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory 2080 ** database created using [sqlite3_deserialize()]. This default maximum 2081 ** size can be adjusted up or down for individual databases using the 2082 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2083 ** configuration setting is never used, then the default maximum is determined 2084 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2085 ** compile-time option is not set, then the default maximum is 1073741824. 2086 ** </dl> 2087 */ 2088 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2089 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2090 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2091 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2092 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2093 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2094 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2095 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2096 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2097 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2098 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2099 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2100 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2101 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2102 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2103 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2104 #define SQLITE_CONFIG_URI 17 /* int */ 2105 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2106 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2107 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2108 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2109 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2110 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2111 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2112 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2113 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2114 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2115 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2116 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2117 2118 /* 2119 ** CAPI3REF: Database Connection Configuration Options 2120 ** 2121 ** These constants are the available integer configuration options that 2122 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 2123 ** 2124 ** New configuration options may be added in future releases of SQLite. 2125 ** Existing configuration options might be discontinued. Applications 2126 ** should check the return code from [sqlite3_db_config()] to make sure that 2127 ** the call worked. ^The [sqlite3_db_config()] interface will return a 2128 ** non-zero [error code] if a discontinued or unsupported configuration option 2129 ** is invoked. 2130 ** 2131 ** <dl> 2132 ** [[SQLITE_DBCONFIG_LOOKASIDE]] 2133 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2134 ** <dd> ^This option takes three additional arguments that determine the 2135 ** [lookaside memory allocator] configuration for the [database connection]. 2136 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2137 ** pointer to a memory buffer to use for lookaside memory. 2138 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2139 ** may be NULL in which case SQLite will allocate the 2140 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2141 ** size of each lookaside buffer slot. ^The third argument is the number of 2142 ** slots. The size of the buffer in the first argument must be greater than 2143 ** or equal to the product of the second and third arguments. The buffer 2144 ** must be aligned to an 8-byte boundary. ^If the second argument to 2145 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2146 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2147 ** configuration for a database connection can only be changed when that 2148 ** connection is not currently using lookaside memory, or in other words 2149 ** when the "current value" returned by 2150 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2151 ** Any attempt to change the lookaside memory configuration when lookaside 2152 ** memory is in use leaves the configuration unchanged and returns 2153 ** [SQLITE_BUSY].)^</dd> 2154 ** 2155 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2156 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2157 ** <dd> ^This option is used to enable or disable the enforcement of 2158 ** [foreign key constraints]. There should be two additional arguments. 2159 ** The first argument is an integer which is 0 to disable FK enforcement, 2160 ** positive to enable FK enforcement or negative to leave FK enforcement 2161 ** unchanged. The second parameter is a pointer to an integer into which 2162 ** is written 0 or 1 to indicate whether FK enforcement is off or on 2163 ** following this call. The second parameter may be a NULL pointer, in 2164 ** which case the FK enforcement setting is not reported back. </dd> 2165 ** 2166 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2167 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2168 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2169 ** There should be two additional arguments. 2170 ** The first argument is an integer which is 0 to disable triggers, 2171 ** positive to enable triggers or negative to leave the setting unchanged. 2172 ** The second parameter is a pointer to an integer into which 2173 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 2174 ** following this call. The second parameter may be a NULL pointer, in 2175 ** which case the trigger setting is not reported back. 2176 ** 2177 ** <p>Originally this option disabled all triggers. ^(However, since 2178 ** SQLite version 3.35.0, TEMP triggers are still allowed even if 2179 ** this option is off. So, in other words, this option now only disables 2180 ** triggers in the main database schema or in the schemas of ATTACH-ed 2181 ** databases.)^ </dd> 2182 ** 2183 ** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2184 ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2185 ** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2186 ** There should be two additional arguments. 2187 ** The first argument is an integer which is 0 to disable views, 2188 ** positive to enable views or negative to leave the setting unchanged. 2189 ** The second parameter is a pointer to an integer into which 2190 ** is written 0 or 1 to indicate whether views are disabled or enabled 2191 ** following this call. The second parameter may be a NULL pointer, in 2192 ** which case the view setting is not reported back. 2193 ** 2194 ** <p>Originally this option disabled all views. ^(However, since 2195 ** SQLite version 3.35.0, TEMP views are still allowed even if 2196 ** this option is off. So, in other words, this option now only disables 2197 ** views in the main database schema or in the schemas of ATTACH-ed 2198 ** databases.)^ </dd> 2199 ** 2200 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2201 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2202 ** <dd> ^This option is used to enable or disable the 2203 ** [fts3_tokenizer()] function which is part of the 2204 ** [FTS3] full-text search engine extension. 2205 ** There should be two additional arguments. 2206 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2207 ** positive to enable fts3_tokenizer() or negative to leave the setting 2208 ** unchanged. 2209 ** The second parameter is a pointer to an integer into which 2210 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2211 ** following this call. The second parameter may be a NULL pointer, in 2212 ** which case the new setting is not reported back. </dd> 2213 ** 2214 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2215 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2216 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2217 ** interface independently of the [load_extension()] SQL function. 2218 ** The [sqlite3_enable_load_extension()] API enables or disables both the 2219 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2220 ** There should be two additional arguments. 2221 ** When the first argument to this interface is 1, then only the C-API is 2222 ** enabled and the SQL function remains disabled. If the first argument to 2223 ** this interface is 0, then both the C-API and the SQL function are disabled. 2224 ** If the first argument is -1, then no changes are made to state of either the 2225 ** C-API or the SQL function. 2226 ** The second parameter is a pointer to an integer into which 2227 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2228 ** is disabled or enabled following this call. The second parameter may 2229 ** be a NULL pointer, in which case the new setting is not reported back. 2230 ** </dd> 2231 ** 2232 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2233 ** <dd> ^This option is used to change the name of the "main" database 2234 ** schema. ^The sole argument is a pointer to a constant UTF8 string 2235 ** which will become the new schema name in place of "main". ^SQLite 2236 ** does not make a copy of the new main schema name string, so the application 2237 ** must ensure that the argument passed into this DBCONFIG option is unchanged 2238 ** until after the database connection closes. 2239 ** </dd> 2240 ** 2241 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2242 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2243 ** <dd> Usually, when a database in wal mode is closed or detached from a 2244 ** database handle, SQLite checks if this will mean that there are now no 2245 ** connections at all to the database. If so, it performs a checkpoint 2246 ** operation before closing the connection. This option may be used to 2247 ** override this behaviour. The first parameter passed to this operation 2248 ** is an integer - positive to disable checkpoints-on-close, or zero (the 2249 ** default) to enable them, and negative to leave the setting unchanged. 2250 ** The second parameter is a pointer to an integer 2251 ** into which is written 0 or 1 to indicate whether checkpoints-on-close 2252 ** have been disabled - 0 if they are not disabled, 1 if they are. 2253 ** </dd> 2254 ** 2255 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2256 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2257 ** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2258 ** a single SQL query statement will always use the same algorithm regardless 2259 ** of values of [bound parameters].)^ The QPSG disables some query optimizations 2260 ** that look at the values of bound parameters, which can make some queries 2261 ** slower. But the QPSG has the advantage of more predictable behavior. With 2262 ** the QPSG active, SQLite will always use the same query plan in the field as 2263 ** was used during testing in the lab. 2264 ** The first argument to this setting is an integer which is 0 to disable 2265 ** the QPSG, positive to enable QPSG, or negative to leave the setting 2266 ** unchanged. The second parameter is a pointer to an integer into which 2267 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2268 ** following this call. 2269 ** </dd> 2270 ** 2271 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2272 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2273 ** include output for any operations performed by trigger programs. This 2274 ** option is used to set or clear (the default) a flag that governs this 2275 ** behavior. The first parameter passed to this operation is an integer - 2276 ** positive to enable output for trigger programs, or zero to disable it, 2277 ** or negative to leave the setting unchanged. 2278 ** The second parameter is a pointer to an integer into which is written 2279 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2280 ** it is not disabled, 1 if it is. 2281 ** </dd> 2282 ** 2283 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2284 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2285 ** [VACUUM] in order to reset a database back to an empty database 2286 ** with no schema and no content. The following process works even for 2287 ** a badly corrupted database file: 2288 ** <ol> 2289 ** <li> If the database connection is newly opened, make sure it has read the 2290 ** database schema by preparing then discarding some query against the 2291 ** database, or calling sqlite3_table_column_metadata(), ignoring any 2292 ** errors. This step is only necessary if the application desires to keep 2293 ** the database in WAL mode after the reset if it was in WAL mode before 2294 ** the reset. 2295 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2296 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2297 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2298 ** </ol> 2299 ** Because resetting a database is destructive and irreversible, the 2300 ** process requires the use of this obscure API and multiple steps to help 2301 ** ensure that it does not happen by accident. 2302 ** 2303 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2304 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2305 ** "defensive" flag for a database connection. When the defensive 2306 ** flag is enabled, language features that allow ordinary SQL to 2307 ** deliberately corrupt the database file are disabled. The disabled 2308 ** features include but are not limited to the following: 2309 ** <ul> 2310 ** <li> The [PRAGMA writable_schema=ON] statement. 2311 ** <li> The [PRAGMA journal_mode=OFF] statement. 2312 ** <li> Writes to the [sqlite_dbpage] virtual table. 2313 ** <li> Direct writes to [shadow tables]. 2314 ** </ul> 2315 ** </dd> 2316 ** 2317 ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2318 ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2319 ** "writable_schema" flag. This has the same effect and is logically equivalent 2320 ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2321 ** The first argument to this setting is an integer which is 0 to disable 2322 ** the writable_schema, positive to enable writable_schema, or negative to 2323 ** leave the setting unchanged. The second parameter is a pointer to an 2324 ** integer into which is written 0 or 1 to indicate whether the writable_schema 2325 ** is enabled or disabled following this call. 2326 ** </dd> 2327 ** 2328 ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2329 ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2330 ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2331 ** the legacy behavior of the [ALTER TABLE RENAME] command such it 2332 ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2333 ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2334 ** additional information. This feature can also be turned on and off 2335 ** using the [PRAGMA legacy_alter_table] statement. 2336 ** </dd> 2337 ** 2338 ** [[SQLITE_DBCONFIG_DQS_DML]] 2339 ** <dt>SQLITE_DBCONFIG_DQS_DML</td> 2340 ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2341 ** the legacy [double-quoted string literal] misfeature for DML statements 2342 ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2343 ** default value of this setting is determined by the [-DSQLITE_DQS] 2344 ** compile-time option. 2345 ** </dd> 2346 ** 2347 ** [[SQLITE_DBCONFIG_DQS_DDL]] 2348 ** <dt>SQLITE_DBCONFIG_DQS_DDL</td> 2349 ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2350 ** the legacy [double-quoted string literal] misfeature for DDL statements, 2351 ** such as CREATE TABLE and CREATE INDEX. The 2352 ** default value of this setting is determined by the [-DSQLITE_DQS] 2353 ** compile-time option. 2354 ** </dd> 2355 ** 2356 ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] 2357 ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td> 2358 ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to 2359 ** assume that database schemas are untainted by malicious content. 2360 ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite 2361 ** takes additional defensive steps to protect the application from harm 2362 ** including: 2363 ** <ul> 2364 ** <li> Prohibit the use of SQL functions inside triggers, views, 2365 ** CHECK constraints, DEFAULT clauses, expression indexes, 2366 ** partial indexes, or generated columns 2367 ** unless those functions are tagged with [SQLITE_INNOCUOUS]. 2368 ** <li> Prohibit the use of virtual tables inside of triggers or views 2369 ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. 2370 ** </ul> 2371 ** This setting defaults to "on" for legacy compatibility, however 2372 ** all applications are advised to turn it off if possible. This setting 2373 ** can also be controlled using the [PRAGMA trusted_schema] statement. 2374 ** </dd> 2375 ** 2376 ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] 2377 ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td> 2378 ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates 2379 ** the legacy file format flag. When activated, this flag causes all newly 2380 ** created database file to have a schema format version number (the 4-byte 2381 ** integer found at offset 44 into the database header) of 1. This in turn 2382 ** means that the resulting database file will be readable and writable by 2383 ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, 2384 ** newly created databases are generally not understandable by SQLite versions 2385 ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there 2386 ** is now scarcely any need to generated database files that are compatible 2387 ** all the way back to version 3.0.0, and so this setting is of little 2388 ** practical use, but is provided so that SQLite can continue to claim the 2389 ** ability to generate new database files that are compatible with version 2390 ** 3.0.0. 2391 ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, 2392 ** the [VACUUM] command will fail with an obscure error when attempting to 2393 ** process a table with generated columns and a descending index. This is 2394 ** not considered a bug since SQLite versions 3.3.0 and earlier do not support 2395 ** either generated columns or decending indexes. 2396 ** </dd> 2397 ** </dl> 2398 */ 2399 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2400 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2401 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2402 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2403 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2404 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2405 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2406 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2407 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2408 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2409 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2410 #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2411 #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2412 #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2413 #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2414 #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2415 #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ 2416 #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ 2417 #define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */ 2418 2419 /* 2420 ** CAPI3REF: Enable Or Disable Extended Result Codes 2421 ** METHOD: sqlite3 2422 ** 2423 ** ^The sqlite3_extended_result_codes() routine enables or disables the 2424 ** [extended result codes] feature of SQLite. ^The extended result 2425 ** codes are disabled by default for historical compatibility. 2426 */ 2427 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2428 2429 /* 2430 ** CAPI3REF: Last Insert Rowid 2431 ** METHOD: sqlite3 2432 ** 2433 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2434 ** has a unique 64-bit signed 2435 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2436 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2437 ** names are not also used by explicitly declared columns. ^If 2438 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2439 ** is another alias for the rowid. 2440 ** 2441 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2442 ** the most recent successful [INSERT] into a rowid table or [virtual table] 2443 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2444 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2445 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2446 ** zero. 2447 ** 2448 ** As well as being set automatically as rows are inserted into database 2449 ** tables, the value returned by this function may be set explicitly by 2450 ** [sqlite3_set_last_insert_rowid()] 2451 ** 2452 ** Some virtual table implementations may INSERT rows into rowid tables as 2453 ** part of committing a transaction (e.g. to flush data accumulated in memory 2454 ** to disk). In this case subsequent calls to this function return the rowid 2455 ** associated with these internal INSERT operations, which leads to 2456 ** unintuitive results. Virtual table implementations that do write to rowid 2457 ** tables in this way can avoid this problem by restoring the original 2458 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2459 ** control to the user. 2460 ** 2461 ** ^(If an [INSERT] occurs within a trigger then this routine will 2462 ** return the [rowid] of the inserted row as long as the trigger is 2463 ** running. Once the trigger program ends, the value returned 2464 ** by this routine reverts to what it was before the trigger was fired.)^ 2465 ** 2466 ** ^An [INSERT] that fails due to a constraint violation is not a 2467 ** successful [INSERT] and does not change the value returned by this 2468 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2469 ** and INSERT OR ABORT make no changes to the return value of this 2470 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2471 ** encounters a constraint violation, it does not fail. The 2472 ** INSERT continues to completion after deleting rows that caused 2473 ** the constraint problem so INSERT OR REPLACE will always change 2474 ** the return value of this interface.)^ 2475 ** 2476 ** ^For the purposes of this routine, an [INSERT] is considered to 2477 ** be successful even if it is subsequently rolled back. 2478 ** 2479 ** This function is accessible to SQL statements via the 2480 ** [last_insert_rowid() SQL function]. 2481 ** 2482 ** If a separate thread performs a new [INSERT] on the same 2483 ** database connection while the [sqlite3_last_insert_rowid()] 2484 ** function is running and thus changes the last insert [rowid], 2485 ** then the value returned by [sqlite3_last_insert_rowid()] is 2486 ** unpredictable and might not equal either the old or the new 2487 ** last insert [rowid]. 2488 */ 2489 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2490 2491 /* 2492 ** CAPI3REF: Set the Last Insert Rowid value. 2493 ** METHOD: sqlite3 2494 ** 2495 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2496 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2497 ** without inserting a row into the database. 2498 */ 2499 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2500 2501 /* 2502 ** CAPI3REF: Count The Number Of Rows Modified 2503 ** METHOD: sqlite3 2504 ** 2505 ** ^These functions return the number of rows modified, inserted or 2506 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2507 ** statement on the database connection specified by the only parameter. 2508 ** The two functions are identical except for the type of the return value 2509 ** and that if the number of rows modified by the most recent INSERT, UPDATE 2510 ** or DELETE is greater than the maximum value supported by type "int", then 2511 ** the return value of sqlite3_changes() is undefined. ^Executing any other 2512 ** type of SQL statement does not modify the value returned by these functions. 2513 ** 2514 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2515 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2516 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2517 ** 2518 ** Changes to a view that are intercepted by 2519 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2520 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2521 ** DELETE statement run on a view is always zero. Only changes made to real 2522 ** tables are counted. 2523 ** 2524 ** Things are more complicated if the sqlite3_changes() function is 2525 ** executed while a trigger program is running. This may happen if the 2526 ** program uses the [changes() SQL function], or if some other callback 2527 ** function invokes sqlite3_changes() directly. Essentially: 2528 ** 2529 ** <ul> 2530 ** <li> ^(Before entering a trigger program the value returned by 2531 ** sqlite3_changes() function is saved. After the trigger program 2532 ** has finished, the original value is restored.)^ 2533 ** 2534 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2535 ** statement sets the value returned by sqlite3_changes() 2536 ** upon completion as normal. Of course, this value will not include 2537 ** any changes performed by sub-triggers, as the sqlite3_changes() 2538 ** value will be saved and restored after each sub-trigger has run.)^ 2539 ** </ul> 2540 ** 2541 ** ^This means that if the changes() SQL function (or similar) is used 2542 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2543 ** returns the value as set when the calling statement began executing. 2544 ** ^If it is used by the second or subsequent such statement within a trigger 2545 ** program, the value returned reflects the number of rows modified by the 2546 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2547 ** 2548 ** If a separate thread makes changes on the same database connection 2549 ** while [sqlite3_changes()] is running then the value returned 2550 ** is unpredictable and not meaningful. 2551 ** 2552 ** See also: 2553 ** <ul> 2554 ** <li> the [sqlite3_total_changes()] interface 2555 ** <li> the [count_changes pragma] 2556 ** <li> the [changes() SQL function] 2557 ** <li> the [data_version pragma] 2558 ** </ul> 2559 */ 2560 SQLITE_API int sqlite3_changes(sqlite3*); 2561 SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*); 2562 2563 /* 2564 ** CAPI3REF: Total Number Of Rows Modified 2565 ** METHOD: sqlite3 2566 ** 2567 ** ^These functions return the total number of rows inserted, modified or 2568 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2569 ** since the database connection was opened, including those executed as 2570 ** part of trigger programs. The two functions are identical except for the 2571 ** type of the return value and that if the number of rows modified by the 2572 ** connection exceeds the maximum value supported by type "int", then 2573 ** the return value of sqlite3_total_changes() is undefined. ^Executing 2574 ** any other type of SQL statement does not affect the value returned by 2575 ** sqlite3_total_changes(). 2576 ** 2577 ** ^Changes made as part of [foreign key actions] are included in the 2578 ** count, but those made as part of REPLACE constraint resolution are 2579 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2580 ** are not counted. 2581 ** 2582 ** The [sqlite3_total_changes(D)] interface only reports the number 2583 ** of rows that changed due to SQL statement run against database 2584 ** connection D. Any changes by other database connections are ignored. 2585 ** To detect changes against a database file from other database 2586 ** connections use the [PRAGMA data_version] command or the 2587 ** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2588 ** 2589 ** If a separate thread makes changes on the same database connection 2590 ** while [sqlite3_total_changes()] is running then the value 2591 ** returned is unpredictable and not meaningful. 2592 ** 2593 ** See also: 2594 ** <ul> 2595 ** <li> the [sqlite3_changes()] interface 2596 ** <li> the [count_changes pragma] 2597 ** <li> the [changes() SQL function] 2598 ** <li> the [data_version pragma] 2599 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2600 ** </ul> 2601 */ 2602 SQLITE_API int sqlite3_total_changes(sqlite3*); 2603 SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*); 2604 2605 /* 2606 ** CAPI3REF: Interrupt A Long-Running Query 2607 ** METHOD: sqlite3 2608 ** 2609 ** ^This function causes any pending database operation to abort and 2610 ** return at its earliest opportunity. This routine is typically 2611 ** called in response to a user action such as pressing "Cancel" 2612 ** or Ctrl-C where the user wants a long query operation to halt 2613 ** immediately. 2614 ** 2615 ** ^It is safe to call this routine from a thread different from the 2616 ** thread that is currently running the database operation. But it 2617 ** is not safe to call this routine with a [database connection] that 2618 ** is closed or might close before sqlite3_interrupt() returns. 2619 ** 2620 ** ^If an SQL operation is very nearly finished at the time when 2621 ** sqlite3_interrupt() is called, then it might not have an opportunity 2622 ** to be interrupted and might continue to completion. 2623 ** 2624 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2625 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2626 ** that is inside an explicit transaction, then the entire transaction 2627 ** will be rolled back automatically. 2628 ** 2629 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2630 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2631 ** that are started after the sqlite3_interrupt() call and before the 2632 ** running statement count reaches zero are interrupted as if they had been 2633 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2634 ** that are started after the running statement count reaches zero are 2635 ** not effected by the sqlite3_interrupt(). 2636 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2637 ** SQL statements is a no-op and has no effect on SQL statements 2638 ** that are started after the sqlite3_interrupt() call returns. 2639 */ 2640 SQLITE_API void sqlite3_interrupt(sqlite3*); 2641 2642 /* 2643 ** CAPI3REF: Determine If An SQL Statement Is Complete 2644 ** 2645 ** These routines are useful during command-line input to determine if the 2646 ** currently entered text seems to form a complete SQL statement or 2647 ** if additional input is needed before sending the text into 2648 ** SQLite for parsing. ^These routines return 1 if the input string 2649 ** appears to be a complete SQL statement. ^A statement is judged to be 2650 ** complete if it ends with a semicolon token and is not a prefix of a 2651 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2652 ** string literals or quoted identifier names or comments are not 2653 ** independent tokens (they are part of the token in which they are 2654 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2655 ** and comments that follow the final semicolon are ignored. 2656 ** 2657 ** ^These routines return 0 if the statement is incomplete. ^If a 2658 ** memory allocation fails, then SQLITE_NOMEM is returned. 2659 ** 2660 ** ^These routines do not parse the SQL statements thus 2661 ** will not detect syntactically incorrect SQL. 2662 ** 2663 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2664 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2665 ** automatically by sqlite3_complete16(). If that initialization fails, 2666 ** then the return value from sqlite3_complete16() will be non-zero 2667 ** regardless of whether or not the input SQL is complete.)^ 2668 ** 2669 ** The input to [sqlite3_complete()] must be a zero-terminated 2670 ** UTF-8 string. 2671 ** 2672 ** The input to [sqlite3_complete16()] must be a zero-terminated 2673 ** UTF-16 string in native byte order. 2674 */ 2675 SQLITE_API int sqlite3_complete(const char *sql); 2676 SQLITE_API int sqlite3_complete16(const void *sql); 2677 2678 /* 2679 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2680 ** KEYWORDS: {busy-handler callback} {busy handler} 2681 ** METHOD: sqlite3 2682 ** 2683 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2684 ** that might be invoked with argument P whenever 2685 ** an attempt is made to access a database table associated with 2686 ** [database connection] D when another thread 2687 ** or process has the table locked. 2688 ** The sqlite3_busy_handler() interface is used to implement 2689 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2690 ** 2691 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2692 ** is returned immediately upon encountering the lock. ^If the busy callback 2693 ** is not NULL, then the callback might be invoked with two arguments. 2694 ** 2695 ** ^The first argument to the busy handler is a copy of the void* pointer which 2696 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2697 ** the busy handler callback is the number of times that the busy handler has 2698 ** been invoked previously for the same locking event. ^If the 2699 ** busy callback returns 0, then no additional attempts are made to 2700 ** access the database and [SQLITE_BUSY] is returned 2701 ** to the application. 2702 ** ^If the callback returns non-zero, then another attempt 2703 ** is made to access the database and the cycle repeats. 2704 ** 2705 ** The presence of a busy handler does not guarantee that it will be invoked 2706 ** when there is lock contention. ^If SQLite determines that invoking the busy 2707 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2708 ** to the application instead of invoking the 2709 ** busy handler. 2710 ** Consider a scenario where one process is holding a read lock that 2711 ** it is trying to promote to a reserved lock and 2712 ** a second process is holding a reserved lock that it is trying 2713 ** to promote to an exclusive lock. The first process cannot proceed 2714 ** because it is blocked by the second and the second process cannot 2715 ** proceed because it is blocked by the first. If both processes 2716 ** invoke the busy handlers, neither will make any progress. Therefore, 2717 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2718 ** will induce the first process to release its read lock and allow 2719 ** the second process to proceed. 2720 ** 2721 ** ^The default busy callback is NULL. 2722 ** 2723 ** ^(There can only be a single busy handler defined for each 2724 ** [database connection]. Setting a new busy handler clears any 2725 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2726 ** or evaluating [PRAGMA busy_timeout=N] will change the 2727 ** busy handler and thus clear any previously set busy handler. 2728 ** 2729 ** The busy callback should not take any actions which modify the 2730 ** database connection that invoked the busy handler. In other words, 2731 ** the busy handler is not reentrant. Any such actions 2732 ** result in undefined behavior. 2733 ** 2734 ** A busy handler must not close the database connection 2735 ** or [prepared statement] that invoked the busy handler. 2736 */ 2737 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2738 2739 /* 2740 ** CAPI3REF: Set A Busy Timeout 2741 ** METHOD: sqlite3 2742 ** 2743 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2744 ** for a specified amount of time when a table is locked. ^The handler 2745 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2746 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2747 ** the handler returns 0 which causes [sqlite3_step()] to return 2748 ** [SQLITE_BUSY]. 2749 ** 2750 ** ^Calling this routine with an argument less than or equal to zero 2751 ** turns off all busy handlers. 2752 ** 2753 ** ^(There can only be a single busy handler for a particular 2754 ** [database connection] at any given moment. If another busy handler 2755 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2756 ** this routine, that other busy handler is cleared.)^ 2757 ** 2758 ** See also: [PRAGMA busy_timeout] 2759 */ 2760 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2761 2762 /* 2763 ** CAPI3REF: Convenience Routines For Running Queries 2764 ** METHOD: sqlite3 2765 ** 2766 ** This is a legacy interface that is preserved for backwards compatibility. 2767 ** Use of this interface is not recommended. 2768 ** 2769 ** Definition: A <b>result table</b> is memory data structure created by the 2770 ** [sqlite3_get_table()] interface. A result table records the 2771 ** complete query results from one or more queries. 2772 ** 2773 ** The table conceptually has a number of rows and columns. But 2774 ** these numbers are not part of the result table itself. These 2775 ** numbers are obtained separately. Let N be the number of rows 2776 ** and M be the number of columns. 2777 ** 2778 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2779 ** There are (N+1)*M elements in the array. The first M pointers point 2780 ** to zero-terminated strings that contain the names of the columns. 2781 ** The remaining entries all point to query results. NULL values result 2782 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2783 ** string representation as returned by [sqlite3_column_text()]. 2784 ** 2785 ** A result table might consist of one or more memory allocations. 2786 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2787 ** A result table should be deallocated using [sqlite3_free_table()]. 2788 ** 2789 ** ^(As an example of the result table format, suppose a query result 2790 ** is as follows: 2791 ** 2792 ** <blockquote><pre> 2793 ** Name | Age 2794 ** ----------------------- 2795 ** Alice | 43 2796 ** Bob | 28 2797 ** Cindy | 21 2798 ** </pre></blockquote> 2799 ** 2800 ** There are two columns (M==2) and three rows (N==3). Thus the 2801 ** result table has 8 entries. Suppose the result table is stored 2802 ** in an array named azResult. Then azResult holds this content: 2803 ** 2804 ** <blockquote><pre> 2805 ** azResult[0] = "Name"; 2806 ** azResult[1] = "Age"; 2807 ** azResult[2] = "Alice"; 2808 ** azResult[3] = "43"; 2809 ** azResult[4] = "Bob"; 2810 ** azResult[5] = "28"; 2811 ** azResult[6] = "Cindy"; 2812 ** azResult[7] = "21"; 2813 ** </pre></blockquote>)^ 2814 ** 2815 ** ^The sqlite3_get_table() function evaluates one or more 2816 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2817 ** string of its 2nd parameter and returns a result table to the 2818 ** pointer given in its 3rd parameter. 2819 ** 2820 ** After the application has finished with the result from sqlite3_get_table(), 2821 ** it must pass the result table pointer to sqlite3_free_table() in order to 2822 ** release the memory that was malloced. Because of the way the 2823 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2824 ** function must not try to call [sqlite3_free()] directly. Only 2825 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2826 ** 2827 ** The sqlite3_get_table() interface is implemented as a wrapper around 2828 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2829 ** to any internal data structures of SQLite. It uses only the public 2830 ** interface defined here. As a consequence, errors that occur in the 2831 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2832 ** reflected in subsequent calls to [sqlite3_errcode()] or 2833 ** [sqlite3_errmsg()]. 2834 */ 2835 SQLITE_API int sqlite3_get_table( 2836 sqlite3 *db, /* An open database */ 2837 const char *zSql, /* SQL to be evaluated */ 2838 char ***pazResult, /* Results of the query */ 2839 int *pnRow, /* Number of result rows written here */ 2840 int *pnColumn, /* Number of result columns written here */ 2841 char **pzErrmsg /* Error msg written here */ 2842 ); 2843 SQLITE_API void sqlite3_free_table(char **result); 2844 2845 /* 2846 ** CAPI3REF: Formatted String Printing Functions 2847 ** 2848 ** These routines are work-alikes of the "printf()" family of functions 2849 ** from the standard C library. 2850 ** These routines understand most of the common formatting options from 2851 ** the standard library printf() 2852 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2853 ** See the [built-in printf()] documentation for details. 2854 ** 2855 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2856 ** results into memory obtained from [sqlite3_malloc64()]. 2857 ** The strings returned by these two routines should be 2858 ** released by [sqlite3_free()]. ^Both routines return a 2859 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2860 ** memory to hold the resulting string. 2861 ** 2862 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2863 ** the standard C library. The result is written into the 2864 ** buffer supplied as the second parameter whose size is given by 2865 ** the first parameter. Note that the order of the 2866 ** first two parameters is reversed from snprintf().)^ This is an 2867 ** historical accident that cannot be fixed without breaking 2868 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2869 ** returns a pointer to its buffer instead of the number of 2870 ** characters actually written into the buffer.)^ We admit that 2871 ** the number of characters written would be a more useful return 2872 ** value but we cannot change the implementation of sqlite3_snprintf() 2873 ** now without breaking compatibility. 2874 ** 2875 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2876 ** guarantees that the buffer is always zero-terminated. ^The first 2877 ** parameter "n" is the total size of the buffer, including space for 2878 ** the zero terminator. So the longest string that can be completely 2879 ** written will be n-1 characters. 2880 ** 2881 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2882 ** 2883 ** See also: [built-in printf()], [printf() SQL function] 2884 */ 2885 SQLITE_API char *sqlite3_mprintf(const char*,...); 2886 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2887 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2888 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2889 2890 /* 2891 ** CAPI3REF: Memory Allocation Subsystem 2892 ** 2893 ** The SQLite core uses these three routines for all of its own 2894 ** internal memory allocation needs. "Core" in the previous sentence 2895 ** does not include operating-system specific [VFS] implementation. The 2896 ** Windows VFS uses native malloc() and free() for some operations. 2897 ** 2898 ** ^The sqlite3_malloc() routine returns a pointer to a block 2899 ** of memory at least N bytes in length, where N is the parameter. 2900 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2901 ** memory, it returns a NULL pointer. ^If the parameter N to 2902 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2903 ** a NULL pointer. 2904 ** 2905 ** ^The sqlite3_malloc64(N) routine works just like 2906 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2907 ** of a signed 32-bit integer. 2908 ** 2909 ** ^Calling sqlite3_free() with a pointer previously returned 2910 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2911 ** that it might be reused. ^The sqlite3_free() routine is 2912 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2913 ** to sqlite3_free() is harmless. After being freed, memory 2914 ** should neither be read nor written. Even reading previously freed 2915 ** memory might result in a segmentation fault or other severe error. 2916 ** Memory corruption, a segmentation fault, or other severe error 2917 ** might result if sqlite3_free() is called with a non-NULL pointer that 2918 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2919 ** 2920 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 2921 ** prior memory allocation X to be at least N bytes. 2922 ** ^If the X parameter to sqlite3_realloc(X,N) 2923 ** is a NULL pointer then its behavior is identical to calling 2924 ** sqlite3_malloc(N). 2925 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2926 ** negative then the behavior is exactly the same as calling 2927 ** sqlite3_free(X). 2928 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2929 ** of at least N bytes in size or NULL if insufficient memory is available. 2930 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2931 ** of the prior allocation are copied into the beginning of buffer returned 2932 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 2933 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2934 ** prior allocation is not freed. 2935 ** 2936 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 2937 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2938 ** of a 32-bit signed integer. 2939 ** 2940 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2941 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2942 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2943 ** ^The value returned by sqlite3_msize(X) might be larger than the number 2944 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 2945 ** sqlite3_msize(X) returns zero. If X points to something that is not 2946 ** the beginning of memory allocation, or if it points to a formerly 2947 ** valid memory allocation that has now been freed, then the behavior 2948 ** of sqlite3_msize(X) is undefined and possibly harmful. 2949 ** 2950 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2951 ** sqlite3_malloc64(), and sqlite3_realloc64() 2952 ** is always aligned to at least an 8 byte boundary, or to a 2953 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2954 ** option is used. 2955 ** 2956 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2957 ** must be either NULL or else pointers obtained from a prior 2958 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2959 ** not yet been released. 2960 ** 2961 ** The application must not read or write any part of 2962 ** a block of memory after it has been released using 2963 ** [sqlite3_free()] or [sqlite3_realloc()]. 2964 */ 2965 SQLITE_API void *sqlite3_malloc(int); 2966 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 2967 SQLITE_API void *sqlite3_realloc(void*, int); 2968 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 2969 SQLITE_API void sqlite3_free(void*); 2970 SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 2971 2972 /* 2973 ** CAPI3REF: Memory Allocator Statistics 2974 ** 2975 ** SQLite provides these two interfaces for reporting on the status 2976 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2977 ** routines, which form the built-in memory allocation subsystem. 2978 ** 2979 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2980 ** of memory currently outstanding (malloced but not freed). 2981 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2982 ** value of [sqlite3_memory_used()] since the high-water mark 2983 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2984 ** [sqlite3_memory_highwater()] include any overhead 2985 ** added by SQLite in its implementation of [sqlite3_malloc()], 2986 ** but not overhead added by the any underlying system library 2987 ** routines that [sqlite3_malloc()] may call. 2988 ** 2989 ** ^The memory high-water mark is reset to the current value of 2990 ** [sqlite3_memory_used()] if and only if the parameter to 2991 ** [sqlite3_memory_highwater()] is true. ^The value returned 2992 ** by [sqlite3_memory_highwater(1)] is the high-water mark 2993 ** prior to the reset. 2994 */ 2995 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2996 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2997 2998 /* 2999 ** CAPI3REF: Pseudo-Random Number Generator 3000 ** 3001 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 3002 ** select random [ROWID | ROWIDs] when inserting new records into a table that 3003 ** already uses the largest possible [ROWID]. The PRNG is also used for 3004 ** the built-in random() and randomblob() SQL functions. This interface allows 3005 ** applications to access the same PRNG for other purposes. 3006 ** 3007 ** ^A call to this routine stores N bytes of randomness into buffer P. 3008 ** ^The P parameter can be a NULL pointer. 3009 ** 3010 ** ^If this routine has not been previously called or if the previous 3011 ** call had N less than one or a NULL pointer for P, then the PRNG is 3012 ** seeded using randomness obtained from the xRandomness method of 3013 ** the default [sqlite3_vfs] object. 3014 ** ^If the previous call to this routine had an N of 1 or more and a 3015 ** non-NULL P then the pseudo-randomness is generated 3016 ** internally and without recourse to the [sqlite3_vfs] xRandomness 3017 ** method. 3018 */ 3019 SQLITE_API void sqlite3_randomness(int N, void *P); 3020 3021 /* 3022 ** CAPI3REF: Compile-Time Authorization Callbacks 3023 ** METHOD: sqlite3 3024 ** KEYWORDS: {authorizer callback} 3025 ** 3026 ** ^This routine registers an authorizer callback with a particular 3027 ** [database connection], supplied in the first argument. 3028 ** ^The authorizer callback is invoked as SQL statements are being compiled 3029 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 3030 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 3031 ** and [sqlite3_prepare16_v3()]. ^At various 3032 ** points during the compilation process, as logic is being created 3033 ** to perform various actions, the authorizer callback is invoked to 3034 ** see if those actions are allowed. ^The authorizer callback should 3035 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 3036 ** specific action but allow the SQL statement to continue to be 3037 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 3038 ** rejected with an error. ^If the authorizer callback returns 3039 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 3040 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 3041 ** the authorizer will fail with an error message. 3042 ** 3043 ** When the callback returns [SQLITE_OK], that means the operation 3044 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 3045 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 3046 ** authorizer will fail with an error message explaining that 3047 ** access is denied. 3048 ** 3049 ** ^The first parameter to the authorizer callback is a copy of the third 3050 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 3051 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 3052 ** the particular action to be authorized. ^The third through sixth parameters 3053 ** to the callback are either NULL pointers or zero-terminated strings 3054 ** that contain additional details about the action to be authorized. 3055 ** Applications must always be prepared to encounter a NULL pointer in any 3056 ** of the third through the sixth parameters of the authorization callback. 3057 ** 3058 ** ^If the action code is [SQLITE_READ] 3059 ** and the callback returns [SQLITE_IGNORE] then the 3060 ** [prepared statement] statement is constructed to substitute 3061 ** a NULL value in place of the table column that would have 3062 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 3063 ** return can be used to deny an untrusted user access to individual 3064 ** columns of a table. 3065 ** ^When a table is referenced by a [SELECT] but no column values are 3066 ** extracted from that table (for example in a query like 3067 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 3068 ** is invoked once for that table with a column name that is an empty string. 3069 ** ^If the action code is [SQLITE_DELETE] and the callback returns 3070 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 3071 ** [truncate optimization] is disabled and all rows are deleted individually. 3072 ** 3073 ** An authorizer is used when [sqlite3_prepare | preparing] 3074 ** SQL statements from an untrusted source, to ensure that the SQL statements 3075 ** do not try to access data they are not allowed to see, or that they do not 3076 ** try to execute malicious statements that damage the database. For 3077 ** example, an application may allow a user to enter arbitrary 3078 ** SQL queries for evaluation by a database. But the application does 3079 ** not want the user to be able to make arbitrary changes to the 3080 ** database. An authorizer could then be put in place while the 3081 ** user-entered SQL is being [sqlite3_prepare | prepared] that 3082 ** disallows everything except [SELECT] statements. 3083 ** 3084 ** Applications that need to process SQL from untrusted sources 3085 ** might also consider lowering resource limits using [sqlite3_limit()] 3086 ** and limiting database size using the [max_page_count] [PRAGMA] 3087 ** in addition to using an authorizer. 3088 ** 3089 ** ^(Only a single authorizer can be in place on a database connection 3090 ** at a time. Each call to sqlite3_set_authorizer overrides the 3091 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 3092 ** The authorizer is disabled by default. 3093 ** 3094 ** The authorizer callback must not do anything that will modify 3095 ** the database connection that invoked the authorizer callback. 3096 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3097 ** database connections for the meaning of "modify" in this paragraph. 3098 ** 3099 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 3100 ** statement might be re-prepared during [sqlite3_step()] due to a 3101 ** schema change. Hence, the application should ensure that the 3102 ** correct authorizer callback remains in place during the [sqlite3_step()]. 3103 ** 3104 ** ^Note that the authorizer callback is invoked only during 3105 ** [sqlite3_prepare()] or its variants. Authorization is not 3106 ** performed during statement evaluation in [sqlite3_step()], unless 3107 ** as stated in the previous paragraph, sqlite3_step() invokes 3108 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 3109 */ 3110 SQLITE_API int sqlite3_set_authorizer( 3111 sqlite3*, 3112 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 3113 void *pUserData 3114 ); 3115 3116 /* 3117 ** CAPI3REF: Authorizer Return Codes 3118 ** 3119 ** The [sqlite3_set_authorizer | authorizer callback function] must 3120 ** return either [SQLITE_OK] or one of these two constants in order 3121 ** to signal SQLite whether or not the action is permitted. See the 3122 ** [sqlite3_set_authorizer | authorizer documentation] for additional 3123 ** information. 3124 ** 3125 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3126 ** returned from the [sqlite3_vtab_on_conflict()] interface. 3127 */ 3128 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 3129 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 3130 3131 /* 3132 ** CAPI3REF: Authorizer Action Codes 3133 ** 3134 ** The [sqlite3_set_authorizer()] interface registers a callback function 3135 ** that is invoked to authorize certain SQL statement actions. The 3136 ** second parameter to the callback is an integer code that specifies 3137 ** what action is being authorized. These are the integer action codes that 3138 ** the authorizer callback may be passed. 3139 ** 3140 ** These action code values signify what kind of operation is to be 3141 ** authorized. The 3rd and 4th parameters to the authorization 3142 ** callback function will be parameters or NULL depending on which of these 3143 ** codes is used as the second parameter. ^(The 5th parameter to the 3144 ** authorizer callback is the name of the database ("main", "temp", 3145 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3146 ** is the name of the inner-most trigger or view that is responsible for 3147 ** the access attempt or NULL if this access attempt is directly from 3148 ** top-level SQL code. 3149 */ 3150 /******************************************* 3rd ************ 4th ***********/ 3151 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3152 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3153 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3154 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3155 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3156 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3157 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3158 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3159 #define SQLITE_DELETE 9 /* Table Name NULL */ 3160 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3161 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3162 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3163 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3164 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3165 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3166 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3167 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3168 #define SQLITE_INSERT 18 /* Table Name NULL */ 3169 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3170 #define SQLITE_READ 20 /* Table Name Column Name */ 3171 #define SQLITE_SELECT 21 /* NULL NULL */ 3172 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 3173 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 3174 #define SQLITE_ATTACH 24 /* Filename NULL */ 3175 #define SQLITE_DETACH 25 /* Database Name NULL */ 3176 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3177 #define SQLITE_REINDEX 27 /* Index Name NULL */ 3178 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 3179 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3180 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3181 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 3182 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3183 #define SQLITE_COPY 0 /* No longer used */ 3184 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 3185 3186 /* 3187 ** CAPI3REF: Tracing And Profiling Functions 3188 ** METHOD: sqlite3 3189 ** 3190 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3191 ** instead of the routines described here. 3192 ** 3193 ** These routines register callback functions that can be used for 3194 ** tracing and profiling the execution of SQL statements. 3195 ** 3196 ** ^The callback function registered by sqlite3_trace() is invoked at 3197 ** various times when an SQL statement is being run by [sqlite3_step()]. 3198 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3199 ** SQL statement text as the statement first begins executing. 3200 ** ^(Additional sqlite3_trace() callbacks might occur 3201 ** as each triggered subprogram is entered. The callbacks for triggers 3202 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 3203 ** 3204 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3205 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3206 ** 3207 ** ^The callback function registered by sqlite3_profile() is invoked 3208 ** as each SQL statement finishes. ^The profile callback contains 3209 ** the original statement text and an estimate of wall-clock time 3210 ** of how long that statement took to run. ^The profile callback 3211 ** time is in units of nanoseconds, however the current implementation 3212 ** is only capable of millisecond resolution so the six least significant 3213 ** digits in the time are meaningless. Future versions of SQLite 3214 ** might provide greater resolution on the profiler callback. Invoking 3215 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3216 ** profile callback. 3217 */ 3218 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3219 void(*xTrace)(void*,const char*), void*); 3220 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3221 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3222 3223 /* 3224 ** CAPI3REF: SQL Trace Event Codes 3225 ** KEYWORDS: SQLITE_TRACE 3226 ** 3227 ** These constants identify classes of events that can be monitored 3228 ** using the [sqlite3_trace_v2()] tracing logic. The M argument 3229 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3230 ** the following constants. ^The first argument to the trace callback 3231 ** is one of the following constants. 3232 ** 3233 ** New tracing constants may be added in future releases. 3234 ** 3235 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 3236 ** ^The T argument is one of the integer type codes above. 3237 ** ^The C argument is a copy of the context pointer passed in as the 3238 ** fourth argument to [sqlite3_trace_v2()]. 3239 ** The P and X arguments are pointers whose meanings depend on T. 3240 ** 3241 ** <dl> 3242 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3243 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3244 ** first begins running and possibly at other times during the 3245 ** execution of the prepared statement, such as at the start of each 3246 ** trigger subprogram. ^The P argument is a pointer to the 3247 ** [prepared statement]. ^The X argument is a pointer to a string which 3248 ** is the unexpanded SQL text of the prepared statement or an SQL comment 3249 ** that indicates the invocation of a trigger. ^The callback can compute 3250 ** the same text that would have been returned by the legacy [sqlite3_trace()] 3251 ** interface by using the X argument when X begins with "--" and invoking 3252 ** [sqlite3_expanded_sql(P)] otherwise. 3253 ** 3254 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3255 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3256 ** information as is provided by the [sqlite3_profile()] callback. 3257 ** ^The P argument is a pointer to the [prepared statement] and the 3258 ** X argument points to a 64-bit integer which is the estimated of 3259 ** the number of nanosecond that the prepared statement took to run. 3260 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3261 ** 3262 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3263 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3264 ** statement generates a single row of result. 3265 ** ^The P argument is a pointer to the [prepared statement] and the 3266 ** X argument is unused. 3267 ** 3268 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3269 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3270 ** connection closes. 3271 ** ^The P argument is a pointer to the [database connection] object 3272 ** and the X argument is unused. 3273 ** </dl> 3274 */ 3275 #define SQLITE_TRACE_STMT 0x01 3276 #define SQLITE_TRACE_PROFILE 0x02 3277 #define SQLITE_TRACE_ROW 0x04 3278 #define SQLITE_TRACE_CLOSE 0x08 3279 3280 /* 3281 ** CAPI3REF: SQL Trace Hook 3282 ** METHOD: sqlite3 3283 ** 3284 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3285 ** function X against [database connection] D, using property mask M 3286 ** and context pointer P. ^If the X callback is 3287 ** NULL or if the M mask is zero, then tracing is disabled. The 3288 ** M argument should be the bitwise OR-ed combination of 3289 ** zero or more [SQLITE_TRACE] constants. 3290 ** 3291 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3292 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3293 ** 3294 ** ^The X callback is invoked whenever any of the events identified by 3295 ** mask M occur. ^The integer return value from the callback is currently 3296 ** ignored, though this may change in future releases. Callback 3297 ** implementations should return zero to ensure future compatibility. 3298 ** 3299 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3300 ** ^The T argument is one of the [SQLITE_TRACE] 3301 ** constants to indicate why the callback was invoked. 3302 ** ^The C argument is a copy of the context pointer. 3303 ** The P and X arguments are pointers whose meanings depend on T. 3304 ** 3305 ** The sqlite3_trace_v2() interface is intended to replace the legacy 3306 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3307 ** are deprecated. 3308 */ 3309 SQLITE_API int sqlite3_trace_v2( 3310 sqlite3*, 3311 unsigned uMask, 3312 int(*xCallback)(unsigned,void*,void*,void*), 3313 void *pCtx 3314 ); 3315 3316 /* 3317 ** CAPI3REF: Query Progress Callbacks 3318 ** METHOD: sqlite3 3319 ** 3320 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3321 ** function X to be invoked periodically during long running calls to 3322 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3323 ** database connection D. An example use for this 3324 ** interface is to keep a GUI updated during a large query. 3325 ** 3326 ** ^The parameter P is passed through as the only parameter to the 3327 ** callback function X. ^The parameter N is the approximate number of 3328 ** [virtual machine instructions] that are evaluated between successive 3329 ** invocations of the callback X. ^If N is less than one then the progress 3330 ** handler is disabled. 3331 ** 3332 ** ^Only a single progress handler may be defined at one time per 3333 ** [database connection]; setting a new progress handler cancels the 3334 ** old one. ^Setting parameter X to NULL disables the progress handler. 3335 ** ^The progress handler is also disabled by setting N to a value less 3336 ** than 1. 3337 ** 3338 ** ^If the progress callback returns non-zero, the operation is 3339 ** interrupted. This feature can be used to implement a 3340 ** "Cancel" button on a GUI progress dialog box. 3341 ** 3342 ** The progress handler callback must not do anything that will modify 3343 ** the database connection that invoked the progress handler. 3344 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3345 ** database connections for the meaning of "modify" in this paragraph. 3346 ** 3347 */ 3348 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3349 3350 /* 3351 ** CAPI3REF: Opening A New Database Connection 3352 ** CONSTRUCTOR: sqlite3 3353 ** 3354 ** ^These routines open an SQLite database file as specified by the 3355 ** filename argument. ^The filename argument is interpreted as UTF-8 for 3356 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3357 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 3358 ** returned in *ppDb, even if an error occurs. The only exception is that 3359 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3360 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3361 ** object.)^ ^(If the database is opened (and/or created) successfully, then 3362 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3363 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3364 ** an English language description of the error following a failure of any 3365 ** of the sqlite3_open() routines. 3366 ** 3367 ** ^The default encoding will be UTF-8 for databases created using 3368 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3369 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 3370 ** 3371 ** Whether or not an error occurs when it is opened, resources 3372 ** associated with the [database connection] handle should be released by 3373 ** passing it to [sqlite3_close()] when it is no longer required. 3374 ** 3375 ** The sqlite3_open_v2() interface works like sqlite3_open() 3376 ** except that it accepts two additional parameters for additional control 3377 ** over the new database connection. ^(The flags parameter to 3378 ** sqlite3_open_v2() must include, at a minimum, one of the following 3379 ** three flag combinations:)^ 3380 ** 3381 ** <dl> 3382 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3383 ** <dd>The database is opened in read-only mode. If the database does not 3384 ** already exist, an error is returned.</dd>)^ 3385 ** 3386 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3387 ** <dd>The database is opened for reading and writing if possible, or reading 3388 ** only if the file is write protected by the operating system. In either 3389 ** case the database must already exist, otherwise an error is returned.</dd>)^ 3390 ** 3391 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3392 ** <dd>The database is opened for reading and writing, and is created if 3393 ** it does not already exist. This is the behavior that is always used for 3394 ** sqlite3_open() and sqlite3_open16().</dd>)^ 3395 ** </dl> 3396 ** 3397 ** In addition to the required flags, the following optional flags are 3398 ** also supported: 3399 ** 3400 ** <dl> 3401 ** ^(<dt>[SQLITE_OPEN_URI]</dt> 3402 ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^ 3403 ** 3404 ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt> 3405 ** <dd>The database will be opened as an in-memory database. The database 3406 ** is named by the "filename" argument for the purposes of cache-sharing, 3407 ** if shared cache mode is enabled, but the "filename" is otherwise ignored. 3408 ** </dd>)^ 3409 ** 3410 ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt> 3411 ** <dd>The new database connection will use the "multi-thread" 3412 ** [threading mode].)^ This means that separate threads are allowed 3413 ** to use SQLite at the same time, as long as each thread is using 3414 ** a different [database connection]. 3415 ** 3416 ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt> 3417 ** <dd>The new database connection will use the "serialized" 3418 ** [threading mode].)^ This means the multiple threads can safely 3419 ** attempt to use the same database connection at the same time. 3420 ** (Mutexes will block any actual concurrency, but in this mode 3421 ** there is no harm in trying.) 3422 ** 3423 ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt> 3424 ** <dd>The database is opened [shared cache] enabled, overriding 3425 ** the default shared cache setting provided by 3426 ** [sqlite3_enable_shared_cache()].)^ 3427 ** 3428 ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt> 3429 ** <dd>The database is opened [shared cache] disabled, overriding 3430 ** the default shared cache setting provided by 3431 ** [sqlite3_enable_shared_cache()].)^ 3432 ** 3433 ** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt> 3434 ** <dd>The database connection comes up in "extended result code mode". 3435 ** In other words, the database behaves has if 3436 ** [sqlite3_extended_result_codes(db,1)] where called on the database 3437 ** connection as soon as the connection is created. In addition to setting 3438 ** the extended result code mode, this flag also causes [sqlite3_open_v2()] 3439 ** to return an extended result code.</dd> 3440 ** 3441 ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt> 3442 ** <dd>The database filename is not allowed to be a symbolic link</dd> 3443 ** </dl>)^ 3444 ** 3445 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3446 ** required combinations shown above optionally combined with other 3447 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3448 ** then the behavior is undefined. Historic versions of SQLite 3449 ** have silently ignored surplus bits in the flags parameter to 3450 ** sqlite3_open_v2(), however that behavior might not be carried through 3451 ** into future versions of SQLite and so applications should not rely 3452 ** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op 3453 ** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause 3454 ** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE 3455 ** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not 3456 ** by sqlite3_open_v2(). 3457 ** 3458 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3459 ** [sqlite3_vfs] object that defines the operating system interface that 3460 ** the new database connection should use. ^If the fourth parameter is 3461 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3462 ** 3463 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3464 ** is created for the connection. ^This in-memory database will vanish when 3465 ** the database connection is closed. Future versions of SQLite might 3466 ** make use of additional special filenames that begin with the ":" character. 3467 ** It is recommended that when a database filename actually does begin with 3468 ** a ":" character you should prefix the filename with a pathname such as 3469 ** "./" to avoid ambiguity. 3470 ** 3471 ** ^If the filename is an empty string, then a private, temporary 3472 ** on-disk database will be created. ^This private database will be 3473 ** automatically deleted as soon as the database connection is closed. 3474 ** 3475 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3476 ** 3477 ** ^If [URI filename] interpretation is enabled, and the filename argument 3478 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3479 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3480 ** set in the third argument to sqlite3_open_v2(), or if it has 3481 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3482 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3483 ** URI filename interpretation is turned off 3484 ** by default, but future releases of SQLite might enable URI filename 3485 ** interpretation by default. See "[URI filenames]" for additional 3486 ** information. 3487 ** 3488 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3489 ** authority, then it must be either an empty string or the string 3490 ** "localhost". ^If the authority is not an empty string or "localhost", an 3491 ** error is returned to the caller. ^The fragment component of a URI, if 3492 ** present, is ignored. 3493 ** 3494 ** ^SQLite uses the path component of the URI as the name of the disk file 3495 ** which contains the database. ^If the path begins with a '/' character, 3496 ** then it is interpreted as an absolute path. ^If the path does not begin 3497 ** with a '/' (meaning that the authority section is omitted from the URI) 3498 ** then the path is interpreted as a relative path. 3499 ** ^(On windows, the first component of an absolute path 3500 ** is a drive specification (e.g. "C:").)^ 3501 ** 3502 ** [[core URI query parameters]] 3503 ** The query component of a URI may contain parameters that are interpreted 3504 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3505 ** SQLite and its built-in [VFSes] interpret the 3506 ** following query parameters: 3507 ** 3508 ** <ul> 3509 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3510 ** a VFS object that provides the operating system interface that should 3511 ** be used to access the database file on disk. ^If this option is set to 3512 ** an empty string the default VFS object is used. ^Specifying an unknown 3513 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3514 ** present, then the VFS specified by the option takes precedence over 3515 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3516 ** 3517 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3518 ** "rwc", or "memory". Attempting to set it to any other value is 3519 ** an error)^. 3520 ** ^If "ro" is specified, then the database is opened for read-only 3521 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3522 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3523 ** "rw", then the database is opened for read-write (but not create) 3524 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3525 ** been set. ^Value "rwc" is equivalent to setting both 3526 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3527 ** set to "memory" then a pure [in-memory database] that never reads 3528 ** or writes from disk is used. ^It is an error to specify a value for 3529 ** the mode parameter that is less restrictive than that specified by 3530 ** the flags passed in the third parameter to sqlite3_open_v2(). 3531 ** 3532 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3533 ** "private". ^Setting it to "shared" is equivalent to setting the 3534 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3535 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3536 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3537 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3538 ** a URI filename, its value overrides any behavior requested by setting 3539 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3540 ** 3541 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3542 ** [powersafe overwrite] property does or does not apply to the 3543 ** storage media on which the database file resides. 3544 ** 3545 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3546 ** which if set disables file locking in rollback journal modes. This 3547 ** is useful for accessing a database on a filesystem that does not 3548 ** support locking. Caution: Database corruption might result if two 3549 ** or more processes write to the same database and any one of those 3550 ** processes uses nolock=1. 3551 ** 3552 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3553 ** parameter that indicates that the database file is stored on 3554 ** read-only media. ^When immutable is set, SQLite assumes that the 3555 ** database file cannot be changed, even by a process with higher 3556 ** privilege, and so the database is opened read-only and all locking 3557 ** and change detection is disabled. Caution: Setting the immutable 3558 ** property on a database file that does in fact change can result 3559 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3560 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3561 ** 3562 ** </ul> 3563 ** 3564 ** ^Specifying an unknown parameter in the query component of a URI is not an 3565 ** error. Future versions of SQLite might understand additional query 3566 ** parameters. See "[query parameters with special meaning to SQLite]" for 3567 ** additional information. 3568 ** 3569 ** [[URI filename examples]] <h3>URI filename examples</h3> 3570 ** 3571 ** <table border="1" align=center cellpadding=5> 3572 ** <tr><th> URI filenames <th> Results 3573 ** <tr><td> file:data.db <td> 3574 ** Open the file "data.db" in the current directory. 3575 ** <tr><td> file:/home/fred/data.db<br> 3576 ** file:///home/fred/data.db <br> 3577 ** file://localhost/home/fred/data.db <br> <td> 3578 ** Open the database file "/home/fred/data.db". 3579 ** <tr><td> file://darkstar/home/fred/data.db <td> 3580 ** An error. "darkstar" is not a recognized authority. 3581 ** <tr><td style="white-space:nowrap"> 3582 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3583 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3584 ** C:. Note that the %20 escaping in this example is not strictly 3585 ** necessary - space characters can be used literally 3586 ** in URI filenames. 3587 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3588 ** Open file "data.db" in the current directory for read-only access. 3589 ** Regardless of whether or not shared-cache mode is enabled by 3590 ** default, use a private cache. 3591 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3592 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3593 ** that uses dot-files in place of posix advisory locking. 3594 ** <tr><td> file:data.db?mode=readonly <td> 3595 ** An error. "readonly" is not a valid option for the "mode" parameter. 3596 ** Use "ro" instead: "file:data.db?mode=ro". 3597 ** </table> 3598 ** 3599 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3600 ** query components of a URI. A hexadecimal escape sequence consists of a 3601 ** percent sign - "%" - followed by exactly two hexadecimal digits 3602 ** specifying an octet value. ^Before the path or query components of a 3603 ** URI filename are interpreted, they are encoded using UTF-8 and all 3604 ** hexadecimal escape sequences replaced by a single byte containing the 3605 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3606 ** the results are undefined. 3607 ** 3608 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3609 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3610 ** codepage is currently defined. Filenames containing international 3611 ** characters must be converted to UTF-8 prior to passing them into 3612 ** sqlite3_open() or sqlite3_open_v2(). 3613 ** 3614 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3615 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3616 ** features that require the use of temporary files may fail. 3617 ** 3618 ** See also: [sqlite3_temp_directory] 3619 */ 3620 SQLITE_API int sqlite3_open( 3621 const char *filename, /* Database filename (UTF-8) */ 3622 sqlite3 **ppDb /* OUT: SQLite db handle */ 3623 ); 3624 SQLITE_API int sqlite3_open16( 3625 const void *filename, /* Database filename (UTF-16) */ 3626 sqlite3 **ppDb /* OUT: SQLite db handle */ 3627 ); 3628 SQLITE_API int sqlite3_open_v2( 3629 const char *filename, /* Database filename (UTF-8) */ 3630 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3631 int flags, /* Flags */ 3632 const char *zVfs /* Name of VFS module to use */ 3633 ); 3634 3635 /* 3636 ** CAPI3REF: Obtain Values For URI Parameters 3637 ** 3638 ** These are utility routines, useful to [VFS|custom VFS implementations], 3639 ** that check if a database file was a URI that contained a specific query 3640 ** parameter, and if so obtains the value of that query parameter. 3641 ** 3642 ** The first parameter to these interfaces (hereafter referred to 3643 ** as F) must be one of: 3644 ** <ul> 3645 ** <li> A database filename pointer created by the SQLite core and 3646 ** passed into the xOpen() method of a VFS implemention, or 3647 ** <li> A filename obtained from [sqlite3_db_filename()], or 3648 ** <li> A new filename constructed using [sqlite3_create_filename()]. 3649 ** </ul> 3650 ** If the F parameter is not one of the above, then the behavior is 3651 ** undefined and probably undesirable. Older versions of SQLite were 3652 ** more tolerant of invalid F parameters than newer versions. 3653 ** 3654 ** If F is a suitable filename (as described in the previous paragraph) 3655 ** and if P is the name of the query parameter, then 3656 ** sqlite3_uri_parameter(F,P) returns the value of the P 3657 ** parameter if it exists or a NULL pointer if P does not appear as a 3658 ** query parameter on F. If P is a query parameter of F and it 3659 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3660 ** a pointer to an empty string. 3661 ** 3662 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3663 ** parameter and returns true (1) or false (0) according to the value 3664 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3665 ** value of query parameter P is one of "yes", "true", or "on" in any 3666 ** case or if the value begins with a non-zero number. The 3667 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3668 ** query parameter P is one of "no", "false", or "off" in any case or 3669 ** if the value begins with a numeric zero. If P is not a query 3670 ** parameter on F or if the value of P does not match any of the 3671 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3672 ** 3673 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3674 ** 64-bit signed integer and returns that integer, or D if P does not 3675 ** exist. If the value of P is something other than an integer, then 3676 ** zero is returned. 3677 ** 3678 ** The sqlite3_uri_key(F,N) returns a pointer to the name (not 3679 ** the value) of the N-th query parameter for filename F, or a NULL 3680 ** pointer if N is less than zero or greater than the number of query 3681 ** parameters minus 1. The N value is zero-based so N should be 0 to obtain 3682 ** the name of the first query parameter, 1 for the second parameter, and 3683 ** so forth. 3684 ** 3685 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3686 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3687 ** is not a database file pathname pointer that the SQLite core passed 3688 ** into the xOpen VFS method, then the behavior of this routine is undefined 3689 ** and probably undesirable. 3690 ** 3691 ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F 3692 ** parameter can also be the name of a rollback journal file or WAL file 3693 ** in addition to the main database file. Prior to version 3.31.0, these 3694 ** routines would only work if F was the name of the main database file. 3695 ** When the F parameter is the name of the rollback journal or WAL file, 3696 ** it has access to all the same query parameters as were found on the 3697 ** main database file. 3698 ** 3699 ** See the [URI filename] documentation for additional information. 3700 */ 3701 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3702 SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3703 SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3704 SQLITE_API const char *sqlite3_uri_key(const char *zFilename, int N); 3705 3706 /* 3707 ** CAPI3REF: Translate filenames 3708 ** 3709 ** These routines are available to [VFS|custom VFS implementations] for 3710 ** translating filenames between the main database file, the journal file, 3711 ** and the WAL file. 3712 ** 3713 ** If F is the name of an sqlite database file, journal file, or WAL file 3714 ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F) 3715 ** returns the name of the corresponding database file. 3716 ** 3717 ** If F is the name of an sqlite database file, journal file, or WAL file 3718 ** passed by the SQLite core into the VFS, or if F is a database filename 3719 ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) 3720 ** returns the name of the corresponding rollback journal file. 3721 ** 3722 ** If F is the name of an sqlite database file, journal file, or WAL file 3723 ** that was passed by the SQLite core into the VFS, or if F is a database 3724 ** filename obtained from [sqlite3_db_filename()], then 3725 ** sqlite3_filename_wal(F) returns the name of the corresponding 3726 ** WAL file. 3727 ** 3728 ** In all of the above, if F is not the name of a database, journal or WAL 3729 ** filename passed into the VFS from the SQLite core and F is not the 3730 ** return value from [sqlite3_db_filename()], then the result is 3731 ** undefined and is likely a memory access violation. 3732 */ 3733 SQLITE_API const char *sqlite3_filename_database(const char*); 3734 SQLITE_API const char *sqlite3_filename_journal(const char*); 3735 SQLITE_API const char *sqlite3_filename_wal(const char*); 3736 3737 /* 3738 ** CAPI3REF: Database File Corresponding To A Journal 3739 ** 3740 ** ^If X is the name of a rollback or WAL-mode journal file that is 3741 ** passed into the xOpen method of [sqlite3_vfs], then 3742 ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file] 3743 ** object that represents the main database file. 3744 ** 3745 ** This routine is intended for use in custom [VFS] implementations 3746 ** only. It is not a general-purpose interface. 3747 ** The argument sqlite3_file_object(X) must be a filename pointer that 3748 ** has been passed into [sqlite3_vfs].xOpen method where the 3749 ** flags parameter to xOpen contains one of the bits 3750 ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use 3751 ** of this routine results in undefined and probably undesirable 3752 ** behavior. 3753 */ 3754 SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*); 3755 3756 /* 3757 ** CAPI3REF: Create and Destroy VFS Filenames 3758 ** 3759 ** These interfces are provided for use by [VFS shim] implementations and 3760 ** are not useful outside of that context. 3761 ** 3762 ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of 3763 ** database filename D with corresponding journal file J and WAL file W and 3764 ** with N URI parameters key/values pairs in the array P. The result from 3765 ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that 3766 ** is safe to pass to routines like: 3767 ** <ul> 3768 ** <li> [sqlite3_uri_parameter()], 3769 ** <li> [sqlite3_uri_boolean()], 3770 ** <li> [sqlite3_uri_int64()], 3771 ** <li> [sqlite3_uri_key()], 3772 ** <li> [sqlite3_filename_database()], 3773 ** <li> [sqlite3_filename_journal()], or 3774 ** <li> [sqlite3_filename_wal()]. 3775 ** </ul> 3776 ** If a memory allocation error occurs, sqlite3_create_filename() might 3777 ** return a NULL pointer. The memory obtained from sqlite3_create_filename(X) 3778 ** must be released by a corresponding call to sqlite3_free_filename(Y). 3779 ** 3780 ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array 3781 ** of 2*N pointers to strings. Each pair of pointers in this array corresponds 3782 ** to a key and value for a query parameter. The P parameter may be a NULL 3783 ** pointer if N is zero. None of the 2*N pointers in the P array may be 3784 ** NULL pointers and key pointers should not be empty strings. 3785 ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may 3786 ** be NULL pointers, though they can be empty strings. 3787 ** 3788 ** The sqlite3_free_filename(Y) routine releases a memory allocation 3789 ** previously obtained from sqlite3_create_filename(). Invoking 3790 ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op. 3791 ** 3792 ** If the Y parameter to sqlite3_free_filename(Y) is anything other 3793 ** than a NULL pointer or a pointer previously acquired from 3794 ** sqlite3_create_filename(), then bad things such as heap 3795 ** corruption or segfaults may occur. The value Y should not be 3796 ** used again after sqlite3_free_filename(Y) has been called. This means 3797 ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y, 3798 ** then the corresponding [sqlite3_module.xClose() method should also be 3799 ** invoked prior to calling sqlite3_free_filename(Y). 3800 */ 3801 SQLITE_API char *sqlite3_create_filename( 3802 const char *zDatabase, 3803 const char *zJournal, 3804 const char *zWal, 3805 int nParam, 3806 const char **azParam 3807 ); 3808 SQLITE_API void sqlite3_free_filename(char*); 3809 3810 /* 3811 ** CAPI3REF: Error Codes And Messages 3812 ** METHOD: sqlite3 3813 ** 3814 ** ^If the most recent sqlite3_* API call associated with 3815 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3816 ** returns the numeric [result code] or [extended result code] for that 3817 ** API call. 3818 ** ^The sqlite3_extended_errcode() 3819 ** interface is the same except that it always returns the 3820 ** [extended result code] even when extended result codes are 3821 ** disabled. 3822 ** 3823 ** The values returned by sqlite3_errcode() and/or 3824 ** sqlite3_extended_errcode() might change with each API call. 3825 ** Except, there are some interfaces that are guaranteed to never 3826 ** change the value of the error code. The error-code preserving 3827 ** interfaces include the following: 3828 ** 3829 ** <ul> 3830 ** <li> sqlite3_errcode() 3831 ** <li> sqlite3_extended_errcode() 3832 ** <li> sqlite3_errmsg() 3833 ** <li> sqlite3_errmsg16() 3834 ** <li> sqlite3_error_offset() 3835 ** </ul> 3836 ** 3837 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3838 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3839 ** ^(Memory to hold the error message string is managed internally. 3840 ** The application does not need to worry about freeing the result. 3841 ** However, the error string might be overwritten or deallocated by 3842 ** subsequent calls to other SQLite interface functions.)^ 3843 ** 3844 ** ^The sqlite3_errstr() interface returns the English-language text 3845 ** that describes the [result code], as UTF-8. 3846 ** ^(Memory to hold the error message string is managed internally 3847 ** and must not be freed by the application)^. 3848 ** 3849 ** ^If the most recent error references a specific token in the input 3850 ** SQL, the sqlite3_error_offset() interface returns the byte offset 3851 ** of the start of that token. ^The byte offset returned by 3852 ** sqlite3_error_offset() assumes that the input SQL is UTF8. 3853 ** ^If the most recent error does not reference a specific token in the input 3854 ** SQL, then the sqlite3_error_offset() function returns -1. 3855 ** 3856 ** When the serialized [threading mode] is in use, it might be the 3857 ** case that a second error occurs on a separate thread in between 3858 ** the time of the first error and the call to these interfaces. 3859 ** When that happens, the second error will be reported since these 3860 ** interfaces always report the most recent result. To avoid 3861 ** this, each thread can obtain exclusive use of the [database connection] D 3862 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3863 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3864 ** all calls to the interfaces listed here are completed. 3865 ** 3866 ** If an interface fails with SQLITE_MISUSE, that means the interface 3867 ** was invoked incorrectly by the application. In that case, the 3868 ** error code and message may or may not be set. 3869 */ 3870 SQLITE_API int sqlite3_errcode(sqlite3 *db); 3871 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3872 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3873 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3874 SQLITE_API const char *sqlite3_errstr(int); 3875 SQLITE_API int sqlite3_error_offset(sqlite3 *db); 3876 3877 /* 3878 ** CAPI3REF: Prepared Statement Object 3879 ** KEYWORDS: {prepared statement} {prepared statements} 3880 ** 3881 ** An instance of this object represents a single SQL statement that 3882 ** has been compiled into binary form and is ready to be evaluated. 3883 ** 3884 ** Think of each SQL statement as a separate computer program. The 3885 ** original SQL text is source code. A prepared statement object 3886 ** is the compiled object code. All SQL must be converted into a 3887 ** prepared statement before it can be run. 3888 ** 3889 ** The life-cycle of a prepared statement object usually goes like this: 3890 ** 3891 ** <ol> 3892 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3893 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 3894 ** interfaces. 3895 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3896 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3897 ** to step 2. Do this zero or more times. 3898 ** <li> Destroy the object using [sqlite3_finalize()]. 3899 ** </ol> 3900 */ 3901 typedef struct sqlite3_stmt sqlite3_stmt; 3902 3903 /* 3904 ** CAPI3REF: Run-time Limits 3905 ** METHOD: sqlite3 3906 ** 3907 ** ^(This interface allows the size of various constructs to be limited 3908 ** on a connection by connection basis. The first parameter is the 3909 ** [database connection] whose limit is to be set or queried. The 3910 ** second parameter is one of the [limit categories] that define a 3911 ** class of constructs to be size limited. The third parameter is the 3912 ** new limit for that construct.)^ 3913 ** 3914 ** ^If the new limit is a negative number, the limit is unchanged. 3915 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3916 ** [limits | hard upper bound] 3917 ** set at compile-time by a C preprocessor macro called 3918 ** [limits | SQLITE_MAX_<i>NAME</i>]. 3919 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3920 ** ^Attempts to increase a limit above its hard upper bound are 3921 ** silently truncated to the hard upper bound. 3922 ** 3923 ** ^Regardless of whether or not the limit was changed, the 3924 ** [sqlite3_limit()] interface returns the prior value of the limit. 3925 ** ^Hence, to find the current value of a limit without changing it, 3926 ** simply invoke this interface with the third parameter set to -1. 3927 ** 3928 ** Run-time limits are intended for use in applications that manage 3929 ** both their own internal database and also databases that are controlled 3930 ** by untrusted external sources. An example application might be a 3931 ** web browser that has its own databases for storing history and 3932 ** separate databases controlled by JavaScript applications downloaded 3933 ** off the Internet. The internal databases can be given the 3934 ** large, default limits. Databases managed by external sources can 3935 ** be given much smaller limits designed to prevent a denial of service 3936 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3937 ** interface to further control untrusted SQL. The size of the database 3938 ** created by an untrusted script can be contained using the 3939 ** [max_page_count] [PRAGMA]. 3940 ** 3941 ** New run-time limit categories may be added in future releases. 3942 */ 3943 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3944 3945 /* 3946 ** CAPI3REF: Run-Time Limit Categories 3947 ** KEYWORDS: {limit category} {*limit categories} 3948 ** 3949 ** These constants define various performance limits 3950 ** that can be lowered at run-time using [sqlite3_limit()]. 3951 ** The synopsis of the meanings of the various limits is shown below. 3952 ** Additional information is available at [limits | Limits in SQLite]. 3953 ** 3954 ** <dl> 3955 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3956 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3957 ** 3958 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3959 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3960 ** 3961 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3962 ** <dd>The maximum number of columns in a table definition or in the 3963 ** result set of a [SELECT] or the maximum number of columns in an index 3964 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 3965 ** 3966 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3967 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3968 ** 3969 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3970 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3971 ** 3972 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3973 ** <dd>The maximum number of instructions in a virtual machine program 3974 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3975 ** the equivalent tries to allocate space for more than this many opcodes 3976 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3977 ** 3978 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3979 ** <dd>The maximum number of arguments on a function.</dd>)^ 3980 ** 3981 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3982 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3983 ** 3984 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3985 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3986 ** <dd>The maximum length of the pattern argument to the [LIKE] or 3987 ** [GLOB] operators.</dd>)^ 3988 ** 3989 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3990 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3991 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3992 ** 3993 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3994 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 3995 ** 3996 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3997 ** <dd>The maximum number of auxiliary worker threads that a single 3998 ** [prepared statement] may start.</dd>)^ 3999 ** </dl> 4000 */ 4001 #define SQLITE_LIMIT_LENGTH 0 4002 #define SQLITE_LIMIT_SQL_LENGTH 1 4003 #define SQLITE_LIMIT_COLUMN 2 4004 #define SQLITE_LIMIT_EXPR_DEPTH 3 4005 #define SQLITE_LIMIT_COMPOUND_SELECT 4 4006 #define SQLITE_LIMIT_VDBE_OP 5 4007 #define SQLITE_LIMIT_FUNCTION_ARG 6 4008 #define SQLITE_LIMIT_ATTACHED 7 4009 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 4010 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 4011 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 4012 #define SQLITE_LIMIT_WORKER_THREADS 11 4013 4014 /* 4015 ** CAPI3REF: Prepare Flags 4016 ** 4017 ** These constants define various flags that can be passed into 4018 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 4019 ** [sqlite3_prepare16_v3()] interfaces. 4020 ** 4021 ** New flags may be added in future releases of SQLite. 4022 ** 4023 ** <dl> 4024 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 4025 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 4026 ** that the prepared statement will be retained for a long time and 4027 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 4028 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will 4029 ** be used just once or at most a few times and then destroyed using 4030 ** [sqlite3_finalize()] relatively soon. The current implementation acts 4031 ** on this hint by avoiding the use of [lookaside memory] so as not to 4032 ** deplete the limited store of lookaside memory. Future versions of 4033 ** SQLite may act on this hint differently. 4034 ** 4035 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 4036 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 4037 ** to be required for any prepared statement that wanted to use the 4038 ** [sqlite3_normalized_sql()] interface. However, the 4039 ** [sqlite3_normalized_sql()] interface is now available to all 4040 ** prepared statements, regardless of whether or not they use this 4041 ** flag. 4042 ** 4043 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 4044 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 4045 ** to return an error (error code SQLITE_ERROR) if the statement uses 4046 ** any virtual tables. 4047 ** </dl> 4048 */ 4049 #define SQLITE_PREPARE_PERSISTENT 0x01 4050 #define SQLITE_PREPARE_NORMALIZE 0x02 4051 #define SQLITE_PREPARE_NO_VTAB 0x04 4052 4053 /* 4054 ** CAPI3REF: Compiling An SQL Statement 4055 ** KEYWORDS: {SQL statement compiler} 4056 ** METHOD: sqlite3 4057 ** CONSTRUCTOR: sqlite3_stmt 4058 ** 4059 ** To execute an SQL statement, it must first be compiled into a byte-code 4060 ** program using one of these routines. Or, in other words, these routines 4061 ** are constructors for the [prepared statement] object. 4062 ** 4063 ** The preferred routine to use is [sqlite3_prepare_v2()]. The 4064 ** [sqlite3_prepare()] interface is legacy and should be avoided. 4065 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 4066 ** for special purposes. 4067 ** 4068 ** The use of the UTF-8 interfaces is preferred, as SQLite currently 4069 ** does all parsing using UTF-8. The UTF-16 interfaces are provided 4070 ** as a convenience. The UTF-16 interfaces work by converting the 4071 ** input text into UTF-8, then invoking the corresponding UTF-8 interface. 4072 ** 4073 ** The first argument, "db", is a [database connection] obtained from a 4074 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 4075 ** [sqlite3_open16()]. The database connection must not have been closed. 4076 ** 4077 ** The second argument, "zSql", is the statement to be compiled, encoded 4078 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 4079 ** and sqlite3_prepare_v3() 4080 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 4081 ** and sqlite3_prepare16_v3() use UTF-16. 4082 ** 4083 ** ^If the nByte argument is negative, then zSql is read up to the 4084 ** first zero terminator. ^If nByte is positive, then it is the 4085 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 4086 ** statement is generated. 4087 ** If the caller knows that the supplied string is nul-terminated, then 4088 ** there is a small performance advantage to passing an nByte parameter that 4089 ** is the number of bytes in the input string <i>including</i> 4090 ** the nul-terminator. 4091 ** 4092 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 4093 ** past the end of the first SQL statement in zSql. These routines only 4094 ** compile the first statement in zSql, so *pzTail is left pointing to 4095 ** what remains uncompiled. 4096 ** 4097 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 4098 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 4099 ** to NULL. ^If the input text contains no SQL (if the input is an empty 4100 ** string or a comment) then *ppStmt is set to NULL. 4101 ** The calling procedure is responsible for deleting the compiled 4102 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 4103 ** ppStmt may not be NULL. 4104 ** 4105 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 4106 ** otherwise an [error code] is returned. 4107 ** 4108 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 4109 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 4110 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 4111 ** are retained for backwards compatibility, but their use is discouraged. 4112 ** ^In the "vX" interfaces, the prepared statement 4113 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 4114 ** original SQL text. This causes the [sqlite3_step()] interface to 4115 ** behave differently in three ways: 4116 ** 4117 ** <ol> 4118 ** <li> 4119 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 4120 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 4121 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 4122 ** retries will occur before sqlite3_step() gives up and returns an error. 4123 ** </li> 4124 ** 4125 ** <li> 4126 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 4127 ** [error codes] or [extended error codes]. ^The legacy behavior was that 4128 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 4129 ** and the application would have to make a second call to [sqlite3_reset()] 4130 ** in order to find the underlying cause of the problem. With the "v2" prepare 4131 ** interfaces, the underlying reason for the error is returned immediately. 4132 ** </li> 4133 ** 4134 ** <li> 4135 ** ^If the specific value bound to a [parameter | host parameter] in the 4136 ** WHERE clause might influence the choice of query plan for a statement, 4137 ** then the statement will be automatically recompiled, as if there had been 4138 ** a schema change, on the first [sqlite3_step()] call following any change 4139 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 4140 ** ^The specific value of a WHERE-clause [parameter] might influence the 4141 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 4142 ** or [GLOB] operator or if the parameter is compared to an indexed column 4143 ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 4144 ** </li> 4145 ** </ol> 4146 ** 4147 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 4148 ** the extra prepFlags parameter, which is a bit array consisting of zero or 4149 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 4150 ** sqlite3_prepare_v2() interface works exactly the same as 4151 ** sqlite3_prepare_v3() with a zero prepFlags parameter. 4152 */ 4153 SQLITE_API int sqlite3_prepare( 4154 sqlite3 *db, /* Database handle */ 4155 const char *zSql, /* SQL statement, UTF-8 encoded */ 4156 int nByte, /* Maximum length of zSql in bytes. */ 4157 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4158 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4159 ); 4160 SQLITE_API int sqlite3_prepare_v2( 4161 sqlite3 *db, /* Database handle */ 4162 const char *zSql, /* SQL statement, UTF-8 encoded */ 4163 int nByte, /* Maximum length of zSql in bytes. */ 4164 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4165 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4166 ); 4167 SQLITE_API int sqlite3_prepare_v3( 4168 sqlite3 *db, /* Database handle */ 4169 const char *zSql, /* SQL statement, UTF-8 encoded */ 4170 int nByte, /* Maximum length of zSql in bytes. */ 4171 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4172 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4173 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4174 ); 4175 SQLITE_API int sqlite3_prepare16( 4176 sqlite3 *db, /* Database handle */ 4177 const void *zSql, /* SQL statement, UTF-16 encoded */ 4178 int nByte, /* Maximum length of zSql in bytes. */ 4179 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4180 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4181 ); 4182 SQLITE_API int sqlite3_prepare16_v2( 4183 sqlite3 *db, /* Database handle */ 4184 const void *zSql, /* SQL statement, UTF-16 encoded */ 4185 int nByte, /* Maximum length of zSql in bytes. */ 4186 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4187 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4188 ); 4189 SQLITE_API int sqlite3_prepare16_v3( 4190 sqlite3 *db, /* Database handle */ 4191 const void *zSql, /* SQL statement, UTF-16 encoded */ 4192 int nByte, /* Maximum length of zSql in bytes. */ 4193 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4194 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4195 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4196 ); 4197 4198 /* 4199 ** CAPI3REF: Retrieving Statement SQL 4200 ** METHOD: sqlite3_stmt 4201 ** 4202 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 4203 ** SQL text used to create [prepared statement] P if P was 4204 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 4205 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4206 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 4207 ** string containing the SQL text of prepared statement P with 4208 ** [bound parameters] expanded. 4209 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 4210 ** string containing the normalized SQL text of prepared statement P. The 4211 ** semantics used to normalize a SQL statement are unspecified and subject 4212 ** to change. At a minimum, literal values will be replaced with suitable 4213 ** placeholders. 4214 ** 4215 ** ^(For example, if a prepared statement is created using the SQL 4216 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 4217 ** and parameter :xyz is unbound, then sqlite3_sql() will return 4218 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 4219 ** will return "SELECT 2345,NULL".)^ 4220 ** 4221 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 4222 ** is available to hold the result, or if the result would exceed the 4223 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 4224 ** 4225 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 4226 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 4227 ** option causes sqlite3_expanded_sql() to always return NULL. 4228 ** 4229 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 4230 ** are managed by SQLite and are automatically freed when the prepared 4231 ** statement is finalized. 4232 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 4233 ** is obtained from [sqlite3_malloc()] and must be freed by the application 4234 ** by passing it to [sqlite3_free()]. 4235 ** 4236 ** ^The sqlite3_normalized_sql() interface is only available if 4237 ** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined. 4238 */ 4239 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 4240 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 4241 #ifdef SQLITE_ENABLE_NORMALIZE 4242 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 4243 #endif 4244 4245 /* 4246 ** CAPI3REF: Determine If An SQL Statement Writes The Database 4247 ** METHOD: sqlite3_stmt 4248 ** 4249 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 4250 ** and only if the [prepared statement] X makes no direct changes to 4251 ** the content of the database file. 4252 ** 4253 ** Note that [application-defined SQL functions] or 4254 ** [virtual tables] might change the database indirectly as a side effect. 4255 ** ^(For example, if an application defines a function "eval()" that 4256 ** calls [sqlite3_exec()], then the following SQL statement would 4257 ** change the database file through side-effects: 4258 ** 4259 ** <blockquote><pre> 4260 ** SELECT eval('DELETE FROM t1') FROM t2; 4261 ** </pre></blockquote> 4262 ** 4263 ** But because the [SELECT] statement does not change the database file 4264 ** directly, sqlite3_stmt_readonly() would still return true.)^ 4265 ** 4266 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 4267 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 4268 ** since the statements themselves do not actually modify the database but 4269 ** rather they control the timing of when other statements modify the 4270 ** database. ^The [ATTACH] and [DETACH] statements also cause 4271 ** sqlite3_stmt_readonly() to return true since, while those statements 4272 ** change the configuration of a database connection, they do not make 4273 ** changes to the content of the database files on disk. 4274 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 4275 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 4276 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 4277 ** sqlite3_stmt_readonly() returns false for those commands. 4278 ** 4279 ** ^This routine returns false if there is any possibility that the 4280 ** statement might change the database file. ^A false return does 4281 ** not guarantee that the statement will change the database file. 4282 ** ^For example, an UPDATE statement might have a WHERE clause that 4283 ** makes it a no-op, but the sqlite3_stmt_readonly() result would still 4284 ** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a 4285 ** read-only no-op if the table already exists, but 4286 ** sqlite3_stmt_readonly() still returns false for such a statement. 4287 ** 4288 ** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN] 4289 ** statement, then sqlite3_stmt_readonly(X) returns the same value as 4290 ** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted. 4291 */ 4292 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 4293 4294 /* 4295 ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 4296 ** METHOD: sqlite3_stmt 4297 ** 4298 ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 4299 ** prepared statement S is an EXPLAIN statement, or 2 if the 4300 ** statement S is an EXPLAIN QUERY PLAN. 4301 ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 4302 ** an ordinary statement or a NULL pointer. 4303 */ 4304 SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 4305 4306 /* 4307 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 4308 ** METHOD: sqlite3_stmt 4309 ** 4310 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 4311 ** [prepared statement] S has been stepped at least once using 4312 ** [sqlite3_step(S)] but has neither run to completion (returned 4313 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 4314 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 4315 ** interface returns false if S is a NULL pointer. If S is not a 4316 ** NULL pointer and is not a pointer to a valid [prepared statement] 4317 ** object, then the behavior is undefined and probably undesirable. 4318 ** 4319 ** This interface can be used in combination [sqlite3_next_stmt()] 4320 ** to locate all prepared statements associated with a database 4321 ** connection that are in need of being reset. This can be used, 4322 ** for example, in diagnostic routines to search for prepared 4323 ** statements that are holding a transaction open. 4324 */ 4325 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 4326 4327 /* 4328 ** CAPI3REF: Dynamically Typed Value Object 4329 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 4330 ** 4331 ** SQLite uses the sqlite3_value object to represent all values 4332 ** that can be stored in a database table. SQLite uses dynamic typing 4333 ** for the values it stores. ^Values stored in sqlite3_value objects 4334 ** can be integers, floating point values, strings, BLOBs, or NULL. 4335 ** 4336 ** An sqlite3_value object may be either "protected" or "unprotected". 4337 ** Some interfaces require a protected sqlite3_value. Other interfaces 4338 ** will accept either a protected or an unprotected sqlite3_value. 4339 ** Every interface that accepts sqlite3_value arguments specifies 4340 ** whether or not it requires a protected sqlite3_value. The 4341 ** [sqlite3_value_dup()] interface can be used to construct a new 4342 ** protected sqlite3_value from an unprotected sqlite3_value. 4343 ** 4344 ** The terms "protected" and "unprotected" refer to whether or not 4345 ** a mutex is held. An internal mutex is held for a protected 4346 ** sqlite3_value object but no mutex is held for an unprotected 4347 ** sqlite3_value object. If SQLite is compiled to be single-threaded 4348 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4349 ** or if SQLite is run in one of reduced mutex modes 4350 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4351 ** then there is no distinction between protected and unprotected 4352 ** sqlite3_value objects and they can be used interchangeably. However, 4353 ** for maximum code portability it is recommended that applications 4354 ** still make the distinction between protected and unprotected 4355 ** sqlite3_value objects even when not strictly required. 4356 ** 4357 ** ^The sqlite3_value objects that are passed as parameters into the 4358 ** implementation of [application-defined SQL functions] are protected. 4359 ** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()] 4360 ** are protected. 4361 ** ^The sqlite3_value object returned by 4362 ** [sqlite3_column_value()] is unprotected. 4363 ** Unprotected sqlite3_value objects may only be used as arguments 4364 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4365 ** [sqlite3_value_dup()]. 4366 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 4367 ** interfaces require protected sqlite3_value objects. 4368 */ 4369 typedef struct sqlite3_value sqlite3_value; 4370 4371 /* 4372 ** CAPI3REF: SQL Function Context Object 4373 ** 4374 ** The context in which an SQL function executes is stored in an 4375 ** sqlite3_context object. ^A pointer to an sqlite3_context object 4376 ** is always first parameter to [application-defined SQL functions]. 4377 ** The application-defined SQL function implementation will pass this 4378 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4379 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4380 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4381 ** and/or [sqlite3_set_auxdata()]. 4382 */ 4383 typedef struct sqlite3_context sqlite3_context; 4384 4385 /* 4386 ** CAPI3REF: Binding Values To Prepared Statements 4387 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4388 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4389 ** METHOD: sqlite3_stmt 4390 ** 4391 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4392 ** literals may be replaced by a [parameter] that matches one of following 4393 ** templates: 4394 ** 4395 ** <ul> 4396 ** <li> ? 4397 ** <li> ?NNN 4398 ** <li> :VVV 4399 ** <li> @VVV 4400 ** <li> $VVV 4401 ** </ul> 4402 ** 4403 ** In the templates above, NNN represents an integer literal, 4404 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 4405 ** parameters (also called "host parameter names" or "SQL parameters") 4406 ** can be set using the sqlite3_bind_*() routines defined here. 4407 ** 4408 ** ^The first argument to the sqlite3_bind_*() routines is always 4409 ** a pointer to the [sqlite3_stmt] object returned from 4410 ** [sqlite3_prepare_v2()] or its variants. 4411 ** 4412 ** ^The second argument is the index of the SQL parameter to be set. 4413 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 4414 ** SQL parameter is used more than once, second and subsequent 4415 ** occurrences have the same index as the first occurrence. 4416 ** ^The index for named parameters can be looked up using the 4417 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 4418 ** for "?NNN" parameters is the value of NNN. 4419 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 4420 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766). 4421 ** 4422 ** ^The third argument is the value to bind to the parameter. 4423 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4424 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4425 ** is ignored and the end result is the same as sqlite3_bind_null(). 4426 ** ^If the third parameter to sqlite3_bind_text() is not NULL, then 4427 ** it should be a pointer to well-formed UTF8 text. 4428 ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then 4429 ** it should be a pointer to well-formed UTF16 text. 4430 ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then 4431 ** it should be a pointer to a well-formed unicode string that is 4432 ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16 4433 ** otherwise. 4434 ** 4435 ** [[byte-order determination rules]] ^The byte-order of 4436 ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF) 4437 ** found in first character, which is removed, or in the absence of a BOM 4438 ** the byte order is the native byte order of the host 4439 ** machine for sqlite3_bind_text16() or the byte order specified in 4440 ** the 6th parameter for sqlite3_bind_text64().)^ 4441 ** ^If UTF16 input text contains invalid unicode 4442 ** characters, then SQLite might change those invalid characters 4443 ** into the unicode replacement character: U+FFFD. 4444 ** 4445 ** ^(In those routines that have a fourth argument, its value is the 4446 ** number of bytes in the parameter. To be clear: the value is the 4447 ** number of <u>bytes</u> in the value, not the number of characters.)^ 4448 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4449 ** is negative, then the length of the string is 4450 ** the number of bytes up to the first zero terminator. 4451 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 4452 ** the behavior is undefined. 4453 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4454 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4455 ** that parameter must be the byte offset 4456 ** where the NUL terminator would occur assuming the string were NUL 4457 ** terminated. If any NUL characters occurs at byte offsets less than 4458 ** the value of the fourth parameter then the resulting string value will 4459 ** contain embedded NULs. The result of expressions involving strings 4460 ** with embedded NULs is undefined. 4461 ** 4462 ** ^The fifth argument to the BLOB and string binding interfaces controls 4463 ** or indicates the lifetime of the object referenced by the third parameter. 4464 ** These three options exist: 4465 ** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished 4466 ** with it may be passed. ^It is called to dispose of the BLOB or string even 4467 ** if the call to the bind API fails, except the destructor is not called if 4468 ** the third parameter is a NULL pointer or the fourth parameter is negative. 4469 ** ^ (2) The special constant, [SQLITE_STATIC], may be passsed to indicate that 4470 ** the application remains responsible for disposing of the object. ^In this 4471 ** case, the object and the provided pointer to it must remain valid until 4472 ** either the prepared statement is finalized or the same SQL parameter is 4473 ** bound to something else, whichever occurs sooner. 4474 ** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the 4475 ** object is to be copied prior to the return from sqlite3_bind_*(). ^The 4476 ** object and pointer to it must remain valid until then. ^SQLite will then 4477 ** manage the lifetime of its private copy. 4478 ** 4479 ** ^The sixth argument to sqlite3_bind_text64() must be one of 4480 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4481 ** to specify the encoding of the text in the third parameter. If 4482 ** the sixth argument to sqlite3_bind_text64() is not one of the 4483 ** allowed values shown above, or if the text encoding is different 4484 ** from the encoding specified by the sixth parameter, then the behavior 4485 ** is undefined. 4486 ** 4487 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4488 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4489 ** (just an integer to hold its size) while it is being processed. 4490 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 4491 ** content is later written using 4492 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 4493 ** ^A negative value for the zeroblob results in a zero-length BLOB. 4494 ** 4495 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4496 ** [prepared statement] S to have an SQL value of NULL, but to also be 4497 ** associated with the pointer P of type T. ^D is either a NULL pointer or 4498 ** a pointer to a destructor function for P. ^SQLite will invoke the 4499 ** destructor D with a single argument of P when it is finished using 4500 ** P. The T parameter should be a static string, preferably a string 4501 ** literal. The sqlite3_bind_pointer() routine is part of the 4502 ** [pointer passing interface] added for SQLite 3.20.0. 4503 ** 4504 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4505 ** for the [prepared statement] or with a prepared statement for which 4506 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4507 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4508 ** routine is passed a [prepared statement] that has been finalized, the 4509 ** result is undefined and probably harmful. 4510 ** 4511 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4512 ** ^Unbound parameters are interpreted as NULL. 4513 ** 4514 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4515 ** [error code] if anything goes wrong. 4516 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4517 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4518 ** [SQLITE_MAX_LENGTH]. 4519 ** ^[SQLITE_RANGE] is returned if the parameter 4520 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4521 ** 4522 ** See also: [sqlite3_bind_parameter_count()], 4523 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4524 */ 4525 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4526 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4527 void(*)(void*)); 4528 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 4529 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 4530 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4531 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 4532 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4533 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4534 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4535 void(*)(void*), unsigned char encoding); 4536 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4537 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4538 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4539 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4540 4541 /* 4542 ** CAPI3REF: Number Of SQL Parameters 4543 ** METHOD: sqlite3_stmt 4544 ** 4545 ** ^This routine can be used to find the number of [SQL parameters] 4546 ** in a [prepared statement]. SQL parameters are tokens of the 4547 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4548 ** placeholders for values that are [sqlite3_bind_blob | bound] 4549 ** to the parameters at a later time. 4550 ** 4551 ** ^(This routine actually returns the index of the largest (rightmost) 4552 ** parameter. For all forms except ?NNN, this will correspond to the 4553 ** number of unique parameters. If parameters of the ?NNN form are used, 4554 ** there may be gaps in the list.)^ 4555 ** 4556 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4557 ** [sqlite3_bind_parameter_name()], and 4558 ** [sqlite3_bind_parameter_index()]. 4559 */ 4560 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 4561 4562 /* 4563 ** CAPI3REF: Name Of A Host Parameter 4564 ** METHOD: sqlite3_stmt 4565 ** 4566 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 4567 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 4568 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4569 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4570 ** respectively. 4571 ** In other words, the initial ":" or "$" or "@" or "?" 4572 ** is included as part of the name.)^ 4573 ** ^Parameters of the form "?" without a following integer have no name 4574 ** and are referred to as "nameless" or "anonymous parameters". 4575 ** 4576 ** ^The first host parameter has an index of 1, not 0. 4577 ** 4578 ** ^If the value N is out of range or if the N-th parameter is 4579 ** nameless, then NULL is returned. ^The returned string is 4580 ** always in UTF-8 encoding even if the named parameter was 4581 ** originally specified as UTF-16 in [sqlite3_prepare16()], 4582 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4583 ** 4584 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4585 ** [sqlite3_bind_parameter_count()], and 4586 ** [sqlite3_bind_parameter_index()]. 4587 */ 4588 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4589 4590 /* 4591 ** CAPI3REF: Index Of A Parameter With A Given Name 4592 ** METHOD: sqlite3_stmt 4593 ** 4594 ** ^Return the index of an SQL parameter given its name. ^The 4595 ** index value returned is suitable for use as the second 4596 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4597 ** is returned if no matching parameter is found. ^The parameter 4598 ** name must be given in UTF-8 even if the original statement 4599 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4600 ** [sqlite3_prepare16_v3()]. 4601 ** 4602 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4603 ** [sqlite3_bind_parameter_count()], and 4604 ** [sqlite3_bind_parameter_name()]. 4605 */ 4606 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4607 4608 /* 4609 ** CAPI3REF: Reset All Bindings On A Prepared Statement 4610 ** METHOD: sqlite3_stmt 4611 ** 4612 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4613 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4614 ** ^Use this routine to reset all host parameters to NULL. 4615 */ 4616 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4617 4618 /* 4619 ** CAPI3REF: Number Of Columns In A Result Set 4620 ** METHOD: sqlite3_stmt 4621 ** 4622 ** ^Return the number of columns in the result set returned by the 4623 ** [prepared statement]. ^If this routine returns 0, that means the 4624 ** [prepared statement] returns no data (for example an [UPDATE]). 4625 ** ^However, just because this routine returns a positive number does not 4626 ** mean that one or more rows of data will be returned. ^A SELECT statement 4627 ** will always have a positive sqlite3_column_count() but depending on the 4628 ** WHERE clause constraints and the table content, it might return no rows. 4629 ** 4630 ** See also: [sqlite3_data_count()] 4631 */ 4632 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 4633 4634 /* 4635 ** CAPI3REF: Column Names In A Result Set 4636 ** METHOD: sqlite3_stmt 4637 ** 4638 ** ^These routines return the name assigned to a particular column 4639 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4640 ** interface returns a pointer to a zero-terminated UTF-8 string 4641 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 4642 ** UTF-16 string. ^The first parameter is the [prepared statement] 4643 ** that implements the [SELECT] statement. ^The second parameter is the 4644 ** column number. ^The leftmost column is number 0. 4645 ** 4646 ** ^The returned string pointer is valid until either the [prepared statement] 4647 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4648 ** reprepared by the first call to [sqlite3_step()] for a particular run 4649 ** or until the next call to 4650 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4651 ** 4652 ** ^If sqlite3_malloc() fails during the processing of either routine 4653 ** (for example during a conversion from UTF-8 to UTF-16) then a 4654 ** NULL pointer is returned. 4655 ** 4656 ** ^The name of a result column is the value of the "AS" clause for 4657 ** that column, if there is an AS clause. If there is no AS clause 4658 ** then the name of the column is unspecified and may change from 4659 ** one release of SQLite to the next. 4660 */ 4661 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4662 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4663 4664 /* 4665 ** CAPI3REF: Source Of Data In A Query Result 4666 ** METHOD: sqlite3_stmt 4667 ** 4668 ** ^These routines provide a means to determine the database, table, and 4669 ** table column that is the origin of a particular result column in 4670 ** [SELECT] statement. 4671 ** ^The name of the database or table or column can be returned as 4672 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4673 ** the database name, the _table_ routines return the table name, and 4674 ** the origin_ routines return the column name. 4675 ** ^The returned string is valid until the [prepared statement] is destroyed 4676 ** using [sqlite3_finalize()] or until the statement is automatically 4677 ** reprepared by the first call to [sqlite3_step()] for a particular run 4678 ** or until the same information is requested 4679 ** again in a different encoding. 4680 ** 4681 ** ^The names returned are the original un-aliased names of the 4682 ** database, table, and column. 4683 ** 4684 ** ^The first argument to these interfaces is a [prepared statement]. 4685 ** ^These functions return information about the Nth result column returned by 4686 ** the statement, where N is the second function argument. 4687 ** ^The left-most column is column 0 for these routines. 4688 ** 4689 ** ^If the Nth column returned by the statement is an expression or 4690 ** subquery and is not a column value, then all of these functions return 4691 ** NULL. ^These routines might also return NULL if a memory allocation error 4692 ** occurs. ^Otherwise, they return the name of the attached database, table, 4693 ** or column that query result column was extracted from. 4694 ** 4695 ** ^As with all other SQLite APIs, those whose names end with "16" return 4696 ** UTF-16 encoded strings and the other functions return UTF-8. 4697 ** 4698 ** ^These APIs are only available if the library was compiled with the 4699 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4700 ** 4701 ** If two or more threads call one or more 4702 ** [sqlite3_column_database_name | column metadata interfaces] 4703 ** for the same [prepared statement] and result column 4704 ** at the same time then the results are undefined. 4705 */ 4706 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4707 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4708 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4709 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4710 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4711 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4712 4713 /* 4714 ** CAPI3REF: Declared Datatype Of A Query Result 4715 ** METHOD: sqlite3_stmt 4716 ** 4717 ** ^(The first parameter is a [prepared statement]. 4718 ** If this statement is a [SELECT] statement and the Nth column of the 4719 ** returned result set of that [SELECT] is a table column (not an 4720 ** expression or subquery) then the declared type of the table 4721 ** column is returned.)^ ^If the Nth column of the result set is an 4722 ** expression or subquery, then a NULL pointer is returned. 4723 ** ^The returned string is always UTF-8 encoded. 4724 ** 4725 ** ^(For example, given the database schema: 4726 ** 4727 ** CREATE TABLE t1(c1 VARIANT); 4728 ** 4729 ** and the following statement to be compiled: 4730 ** 4731 ** SELECT c1 + 1, c1 FROM t1; 4732 ** 4733 ** this routine would return the string "VARIANT" for the second result 4734 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4735 ** 4736 ** ^SQLite uses dynamic run-time typing. ^So just because a column 4737 ** is declared to contain a particular type does not mean that the 4738 ** data stored in that column is of the declared type. SQLite is 4739 ** strongly typed, but the typing is dynamic not static. ^Type 4740 ** is associated with individual values, not with the containers 4741 ** used to hold those values. 4742 */ 4743 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4744 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4745 4746 /* 4747 ** CAPI3REF: Evaluate An SQL Statement 4748 ** METHOD: sqlite3_stmt 4749 ** 4750 ** After a [prepared statement] has been prepared using any of 4751 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4752 ** or [sqlite3_prepare16_v3()] or one of the legacy 4753 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4754 ** must be called one or more times to evaluate the statement. 4755 ** 4756 ** The details of the behavior of the sqlite3_step() interface depend 4757 ** on whether the statement was prepared using the newer "vX" interfaces 4758 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4759 ** [sqlite3_prepare16_v2()] or the older legacy 4760 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4761 ** new "vX" interface is recommended for new applications but the legacy 4762 ** interface will continue to be supported. 4763 ** 4764 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4765 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4766 ** ^With the "v2" interface, any of the other [result codes] or 4767 ** [extended result codes] might be returned as well. 4768 ** 4769 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4770 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 4771 ** or occurs outside of an explicit transaction, then you can retry the 4772 ** statement. If the statement is not a [COMMIT] and occurs within an 4773 ** explicit transaction then you should rollback the transaction before 4774 ** continuing. 4775 ** 4776 ** ^[SQLITE_DONE] means that the statement has finished executing 4777 ** successfully. sqlite3_step() should not be called again on this virtual 4778 ** machine without first calling [sqlite3_reset()] to reset the virtual 4779 ** machine back to its initial state. 4780 ** 4781 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4782 ** is returned each time a new row of data is ready for processing by the 4783 ** caller. The values may be accessed using the [column access functions]. 4784 ** sqlite3_step() is called again to retrieve the next row of data. 4785 ** 4786 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4787 ** violation) has occurred. sqlite3_step() should not be called again on 4788 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 4789 ** ^With the legacy interface, a more specific error code (for example, 4790 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4791 ** can be obtained by calling [sqlite3_reset()] on the 4792 ** [prepared statement]. ^In the "v2" interface, 4793 ** the more specific error code is returned directly by sqlite3_step(). 4794 ** 4795 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4796 ** Perhaps it was called on a [prepared statement] that has 4797 ** already been [sqlite3_finalize | finalized] or on one that had 4798 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4799 ** be the case that the same database connection is being used by two or 4800 ** more threads at the same moment in time. 4801 ** 4802 ** For all versions of SQLite up to and including 3.6.23.1, a call to 4803 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 4804 ** other than [SQLITE_ROW] before any subsequent invocation of 4805 ** sqlite3_step(). Failure to reset the prepared statement using 4806 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4807 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4808 ** sqlite3_step() began 4809 ** calling [sqlite3_reset()] automatically in this circumstance rather 4810 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4811 ** break because any application that ever receives an SQLITE_MISUSE error 4812 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4813 ** can be used to restore the legacy behavior. 4814 ** 4815 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4816 ** API always returns a generic error code, [SQLITE_ERROR], following any 4817 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4818 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4819 ** specific [error codes] that better describes the error. 4820 ** We admit that this is a goofy design. The problem has been fixed 4821 ** with the "v2" interface. If you prepare all of your SQL statements 4822 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4823 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4824 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4825 ** then the more specific [error codes] are returned directly 4826 ** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4827 */ 4828 SQLITE_API int sqlite3_step(sqlite3_stmt*); 4829 4830 /* 4831 ** CAPI3REF: Number of columns in a result set 4832 ** METHOD: sqlite3_stmt 4833 ** 4834 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 4835 ** current row of the result set of [prepared statement] P. 4836 ** ^If prepared statement P does not have results ready to return 4837 ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 4838 ** interfaces) then sqlite3_data_count(P) returns 0. 4839 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4840 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4841 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4842 ** will return non-zero if previous call to [sqlite3_step](P) returned 4843 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4844 ** where it always returns zero since each step of that multi-step 4845 ** pragma returns 0 columns of data. 4846 ** 4847 ** See also: [sqlite3_column_count()] 4848 */ 4849 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4850 4851 /* 4852 ** CAPI3REF: Fundamental Datatypes 4853 ** KEYWORDS: SQLITE_TEXT 4854 ** 4855 ** ^(Every value in SQLite has one of five fundamental datatypes: 4856 ** 4857 ** <ul> 4858 ** <li> 64-bit signed integer 4859 ** <li> 64-bit IEEE floating point number 4860 ** <li> string 4861 ** <li> BLOB 4862 ** <li> NULL 4863 ** </ul>)^ 4864 ** 4865 ** These constants are codes for each of those types. 4866 ** 4867 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4868 ** for a completely different meaning. Software that links against both 4869 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4870 ** SQLITE_TEXT. 4871 */ 4872 #define SQLITE_INTEGER 1 4873 #define SQLITE_FLOAT 2 4874 #define SQLITE_BLOB 4 4875 #define SQLITE_NULL 5 4876 #ifdef SQLITE_TEXT 4877 # undef SQLITE_TEXT 4878 #else 4879 # define SQLITE_TEXT 3 4880 #endif 4881 #define SQLITE3_TEXT 3 4882 4883 /* 4884 ** CAPI3REF: Result Values From A Query 4885 ** KEYWORDS: {column access functions} 4886 ** METHOD: sqlite3_stmt 4887 ** 4888 ** <b>Summary:</b> 4889 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4890 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4891 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4892 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4893 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4894 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4895 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4896 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4897 ** [sqlite3_value|unprotected sqlite3_value] object. 4898 ** <tr><td> <td> <td> 4899 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4900 ** or a UTF-8 TEXT result in bytes 4901 ** <tr><td><b>sqlite3_column_bytes16 </b> 4902 ** <td>→ <td>Size of UTF-16 4903 ** TEXT in bytes 4904 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4905 ** datatype of the result 4906 ** </table></blockquote> 4907 ** 4908 ** <b>Details:</b> 4909 ** 4910 ** ^These routines return information about a single column of the current 4911 ** result row of a query. ^In every case the first argument is a pointer 4912 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4913 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4914 ** and the second argument is the index of the column for which information 4915 ** should be returned. ^The leftmost column of the result set has the index 0. 4916 ** ^The number of columns in the result can be determined using 4917 ** [sqlite3_column_count()]. 4918 ** 4919 ** If the SQL statement does not currently point to a valid row, or if the 4920 ** column index is out of range, the result is undefined. 4921 ** These routines may only be called when the most recent call to 4922 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4923 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4924 ** If any of these routines are called after [sqlite3_reset()] or 4925 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4926 ** something other than [SQLITE_ROW], the results are undefined. 4927 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4928 ** are called from a different thread while any of these routines 4929 ** are pending, then the results are undefined. 4930 ** 4931 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4932 ** each return the value of a result column in a specific data format. If 4933 ** the result column is not initially in the requested format (for example, 4934 ** if the query returns an integer but the sqlite3_column_text() interface 4935 ** is used to extract the value) then an automatic type conversion is performed. 4936 ** 4937 ** ^The sqlite3_column_type() routine returns the 4938 ** [SQLITE_INTEGER | datatype code] for the initial data type 4939 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4940 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4941 ** The return value of sqlite3_column_type() can be used to decide which 4942 ** of the first six interface should be used to extract the column value. 4943 ** The value returned by sqlite3_column_type() is only meaningful if no 4944 ** automatic type conversions have occurred for the value in question. 4945 ** After a type conversion, the result of calling sqlite3_column_type() 4946 ** is undefined, though harmless. Future 4947 ** versions of SQLite may change the behavior of sqlite3_column_type() 4948 ** following a type conversion. 4949 ** 4950 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4951 ** or sqlite3_column_bytes16() interfaces can be used to determine the size 4952 ** of that BLOB or string. 4953 ** 4954 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4955 ** routine returns the number of bytes in that BLOB or string. 4956 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4957 ** the string to UTF-8 and then returns the number of bytes. 4958 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 4959 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4960 ** the number of bytes in that string. 4961 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4962 ** 4963 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4964 ** routine returns the number of bytes in that BLOB or string. 4965 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4966 ** the string to UTF-16 and then returns the number of bytes. 4967 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4968 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4969 ** the number of bytes in that string. 4970 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4971 ** 4972 ** ^The values returned by [sqlite3_column_bytes()] and 4973 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4974 ** of the string. ^For clarity: the values returned by 4975 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4976 ** bytes in the string, not the number of characters. 4977 ** 4978 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4979 ** even empty strings, are always zero-terminated. ^The return 4980 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4981 ** 4982 ** ^Strings returned by sqlite3_column_text16() always have the endianness 4983 ** which is native to the platform, regardless of the text encoding set 4984 ** for the database. 4985 ** 4986 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4987 ** [unprotected sqlite3_value] object. In a multithreaded environment, 4988 ** an unprotected sqlite3_value object may only be used safely with 4989 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4990 ** If the [unprotected sqlite3_value] object returned by 4991 ** [sqlite3_column_value()] is used in any other way, including calls 4992 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4993 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4994 ** Hence, the sqlite3_column_value() interface 4995 ** is normally only useful within the implementation of 4996 ** [application-defined SQL functions] or [virtual tables], not within 4997 ** top-level application code. 4998 ** 4999 ** These routines may attempt to convert the datatype of the result. 5000 ** ^For example, if the internal representation is FLOAT and a text result 5001 ** is requested, [sqlite3_snprintf()] is used internally to perform the 5002 ** conversion automatically. ^(The following table details the conversions 5003 ** that are applied: 5004 ** 5005 ** <blockquote> 5006 ** <table border="1"> 5007 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 5008 ** 5009 ** <tr><td> NULL <td> INTEGER <td> Result is 0 5010 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 5011 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 5012 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 5013 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 5014 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 5015 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 5016 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 5017 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 5018 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 5019 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 5020 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 5021 ** <tr><td> TEXT <td> BLOB <td> No change 5022 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 5023 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 5024 ** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator 5025 ** </table> 5026 ** </blockquote>)^ 5027 ** 5028 ** Note that when type conversions occur, pointers returned by prior 5029 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 5030 ** sqlite3_column_text16() may be invalidated. 5031 ** Type conversions and pointer invalidations might occur 5032 ** in the following cases: 5033 ** 5034 ** <ul> 5035 ** <li> The initial content is a BLOB and sqlite3_column_text() or 5036 ** sqlite3_column_text16() is called. A zero-terminator might 5037 ** need to be added to the string.</li> 5038 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 5039 ** sqlite3_column_text16() is called. The content must be converted 5040 ** to UTF-16.</li> 5041 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 5042 ** sqlite3_column_text() is called. The content must be converted 5043 ** to UTF-8.</li> 5044 ** </ul> 5045 ** 5046 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 5047 ** not invalidate a prior pointer, though of course the content of the buffer 5048 ** that the prior pointer references will have been modified. Other kinds 5049 ** of conversion are done in place when it is possible, but sometimes they 5050 ** are not possible and in those cases prior pointers are invalidated. 5051 ** 5052 ** The safest policy is to invoke these routines 5053 ** in one of the following ways: 5054 ** 5055 ** <ul> 5056 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 5057 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 5058 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 5059 ** </ul> 5060 ** 5061 ** In other words, you should call sqlite3_column_text(), 5062 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 5063 ** into the desired format, then invoke sqlite3_column_bytes() or 5064 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 5065 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 5066 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 5067 ** with calls to sqlite3_column_bytes(). 5068 ** 5069 ** ^The pointers returned are valid until a type conversion occurs as 5070 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 5071 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 5072 ** and BLOBs is freed automatically. Do not pass the pointers returned 5073 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 5074 ** [sqlite3_free()]. 5075 ** 5076 ** As long as the input parameters are correct, these routines will only 5077 ** fail if an out-of-memory error occurs during a format conversion. 5078 ** Only the following subset of interfaces are subject to out-of-memory 5079 ** errors: 5080 ** 5081 ** <ul> 5082 ** <li> sqlite3_column_blob() 5083 ** <li> sqlite3_column_text() 5084 ** <li> sqlite3_column_text16() 5085 ** <li> sqlite3_column_bytes() 5086 ** <li> sqlite3_column_bytes16() 5087 ** </ul> 5088 ** 5089 ** If an out-of-memory error occurs, then the return value from these 5090 ** routines is the same as if the column had contained an SQL NULL value. 5091 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5092 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5093 ** return value is obtained and before any 5094 ** other SQLite interface is called on the same [database connection]. 5095 */ 5096 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 5097 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 5098 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 5099 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 5100 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 5101 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 5102 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 5103 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 5104 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 5105 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 5106 5107 /* 5108 ** CAPI3REF: Destroy A Prepared Statement Object 5109 ** DESTRUCTOR: sqlite3_stmt 5110 ** 5111 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 5112 ** ^If the most recent evaluation of the statement encountered no errors 5113 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 5114 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 5115 ** sqlite3_finalize(S) returns the appropriate [error code] or 5116 ** [extended error code]. 5117 ** 5118 ** ^The sqlite3_finalize(S) routine can be called at any point during 5119 ** the life cycle of [prepared statement] S: 5120 ** before statement S is ever evaluated, after 5121 ** one or more calls to [sqlite3_reset()], or after any call 5122 ** to [sqlite3_step()] regardless of whether or not the statement has 5123 ** completed execution. 5124 ** 5125 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 5126 ** 5127 ** The application must finalize every [prepared statement] in order to avoid 5128 ** resource leaks. It is a grievous error for the application to try to use 5129 ** a prepared statement after it has been finalized. Any use of a prepared 5130 ** statement after it has been finalized can result in undefined and 5131 ** undesirable behavior such as segfaults and heap corruption. 5132 */ 5133 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 5134 5135 /* 5136 ** CAPI3REF: Reset A Prepared Statement Object 5137 ** METHOD: sqlite3_stmt 5138 ** 5139 ** The sqlite3_reset() function is called to reset a [prepared statement] 5140 ** object back to its initial state, ready to be re-executed. 5141 ** ^Any SQL statement variables that had values bound to them using 5142 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 5143 ** Use [sqlite3_clear_bindings()] to reset the bindings. 5144 ** 5145 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 5146 ** back to the beginning of its program. 5147 ** 5148 ** ^If the most recent call to [sqlite3_step(S)] for the 5149 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 5150 ** or if [sqlite3_step(S)] has never before been called on S, 5151 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 5152 ** 5153 ** ^If the most recent call to [sqlite3_step(S)] for the 5154 ** [prepared statement] S indicated an error, then 5155 ** [sqlite3_reset(S)] returns an appropriate [error code]. 5156 ** 5157 ** ^The [sqlite3_reset(S)] interface does not change the values 5158 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 5159 */ 5160 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 5161 5162 /* 5163 ** CAPI3REF: Create Or Redefine SQL Functions 5164 ** KEYWORDS: {function creation routines} 5165 ** METHOD: sqlite3 5166 ** 5167 ** ^These functions (collectively known as "function creation routines") 5168 ** are used to add SQL functions or aggregates or to redefine the behavior 5169 ** of existing SQL functions or aggregates. The only differences between 5170 ** the three "sqlite3_create_function*" routines are the text encoding 5171 ** expected for the second parameter (the name of the function being 5172 ** created) and the presence or absence of a destructor callback for 5173 ** the application data pointer. Function sqlite3_create_window_function() 5174 ** is similar, but allows the user to supply the extra callback functions 5175 ** needed by [aggregate window functions]. 5176 ** 5177 ** ^The first parameter is the [database connection] to which the SQL 5178 ** function is to be added. ^If an application uses more than one database 5179 ** connection then application-defined SQL functions must be added 5180 ** to each database connection separately. 5181 ** 5182 ** ^The second parameter is the name of the SQL function to be created or 5183 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 5184 ** representation, exclusive of the zero-terminator. ^Note that the name 5185 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 5186 ** ^Any attempt to create a function with a longer name 5187 ** will result in [SQLITE_MISUSE] being returned. 5188 ** 5189 ** ^The third parameter (nArg) 5190 ** is the number of arguments that the SQL function or 5191 ** aggregate takes. ^If this parameter is -1, then the SQL function or 5192 ** aggregate may take any number of arguments between 0 and the limit 5193 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 5194 ** parameter is less than -1 or greater than 127 then the behavior is 5195 ** undefined. 5196 ** 5197 ** ^The fourth parameter, eTextRep, specifies what 5198 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 5199 ** its parameters. The application should set this parameter to 5200 ** [SQLITE_UTF16LE] if the function implementation invokes 5201 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 5202 ** implementation invokes [sqlite3_value_text16be()] on an input, or 5203 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 5204 ** otherwise. ^The same SQL function may be registered multiple times using 5205 ** different preferred text encodings, with different implementations for 5206 ** each encoding. 5207 ** ^When multiple implementations of the same function are available, SQLite 5208 ** will pick the one that involves the least amount of data conversion. 5209 ** 5210 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 5211 ** to signal that the function will always return the same result given 5212 ** the same inputs within a single SQL statement. Most SQL functions are 5213 ** deterministic. The built-in [random()] SQL function is an example of a 5214 ** function that is not deterministic. The SQLite query planner is able to 5215 ** perform additional optimizations on deterministic functions, so use 5216 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 5217 ** 5218 ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 5219 ** flag, which if present prevents the function from being invoked from 5220 ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions, 5221 ** index expressions, or the WHERE clause of partial indexes. 5222 ** 5223 ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for 5224 ** all application-defined SQL functions that do not need to be 5225 ** used inside of triggers, view, CHECK constraints, or other elements of 5226 ** the database schema. This flags is especially recommended for SQL 5227 ** functions that have side effects or reveal internal application state. 5228 ** Without this flag, an attacker might be able to modify the schema of 5229 ** a database file to include invocations of the function with parameters 5230 ** chosen by the attacker, which the application will then execute when 5231 ** the database file is opened and read. 5232 ** 5233 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 5234 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 5235 ** 5236 ** ^The sixth, seventh and eighth parameters passed to the three 5237 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 5238 ** pointers to C-language functions that implement the SQL function or 5239 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 5240 ** callback only; NULL pointers must be passed as the xStep and xFinal 5241 ** parameters. ^An aggregate SQL function requires an implementation of xStep 5242 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 5243 ** SQL function or aggregate, pass NULL pointers for all three function 5244 ** callbacks. 5245 ** 5246 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 5247 ** and xInverse) passed to sqlite3_create_window_function are pointers to 5248 ** C-language callbacks that implement the new function. xStep and xFinal 5249 ** must both be non-NULL. xValue and xInverse may either both be NULL, in 5250 ** which case a regular aggregate function is created, or must both be 5251 ** non-NULL, in which case the new function may be used as either an aggregate 5252 ** or aggregate window function. More details regarding the implementation 5253 ** of aggregate window functions are 5254 ** [user-defined window functions|available here]. 5255 ** 5256 ** ^(If the final parameter to sqlite3_create_function_v2() or 5257 ** sqlite3_create_window_function() is not NULL, then it is destructor for 5258 ** the application data pointer. The destructor is invoked when the function 5259 ** is deleted, either by being overloaded or when the database connection 5260 ** closes.)^ ^The destructor is also invoked if the call to 5261 ** sqlite3_create_function_v2() fails. ^When the destructor callback is 5262 ** invoked, it is passed a single argument which is a copy of the application 5263 ** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 5264 ** 5265 ** ^It is permitted to register multiple implementations of the same 5266 ** functions with the same name but with either differing numbers of 5267 ** arguments or differing preferred text encodings. ^SQLite will use 5268 ** the implementation that most closely matches the way in which the 5269 ** SQL function is used. ^A function implementation with a non-negative 5270 ** nArg parameter is a better match than a function implementation with 5271 ** a negative nArg. ^A function where the preferred text encoding 5272 ** matches the database encoding is a better 5273 ** match than a function where the encoding is different. 5274 ** ^A function where the encoding difference is between UTF16le and UTF16be 5275 ** is a closer match than a function where the encoding difference is 5276 ** between UTF8 and UTF16. 5277 ** 5278 ** ^Built-in functions may be overloaded by new application-defined functions. 5279 ** 5280 ** ^An application-defined function is permitted to call other 5281 ** SQLite interfaces. However, such calls must not 5282 ** close the database connection nor finalize or reset the prepared 5283 ** statement in which the function is running. 5284 */ 5285 SQLITE_API int sqlite3_create_function( 5286 sqlite3 *db, 5287 const char *zFunctionName, 5288 int nArg, 5289 int eTextRep, 5290 void *pApp, 5291 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5292 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5293 void (*xFinal)(sqlite3_context*) 5294 ); 5295 SQLITE_API int sqlite3_create_function16( 5296 sqlite3 *db, 5297 const void *zFunctionName, 5298 int nArg, 5299 int eTextRep, 5300 void *pApp, 5301 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5302 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5303 void (*xFinal)(sqlite3_context*) 5304 ); 5305 SQLITE_API int sqlite3_create_function_v2( 5306 sqlite3 *db, 5307 const char *zFunctionName, 5308 int nArg, 5309 int eTextRep, 5310 void *pApp, 5311 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5312 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5313 void (*xFinal)(sqlite3_context*), 5314 void(*xDestroy)(void*) 5315 ); 5316 SQLITE_API int sqlite3_create_window_function( 5317 sqlite3 *db, 5318 const char *zFunctionName, 5319 int nArg, 5320 int eTextRep, 5321 void *pApp, 5322 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5323 void (*xFinal)(sqlite3_context*), 5324 void (*xValue)(sqlite3_context*), 5325 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 5326 void(*xDestroy)(void*) 5327 ); 5328 5329 /* 5330 ** CAPI3REF: Text Encodings 5331 ** 5332 ** These constant define integer codes that represent the various 5333 ** text encodings supported by SQLite. 5334 */ 5335 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 5336 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 5337 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 5338 #define SQLITE_UTF16 4 /* Use native byte order */ 5339 #define SQLITE_ANY 5 /* Deprecated */ 5340 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 5341 5342 /* 5343 ** CAPI3REF: Function Flags 5344 ** 5345 ** These constants may be ORed together with the 5346 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 5347 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 5348 ** [sqlite3_create_function_v2()]. 5349 ** 5350 ** <dl> 5351 ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd> 5352 ** The SQLITE_DETERMINISTIC flag means that the new function always gives 5353 ** the same output when the input parameters are the same. 5354 ** The [abs|abs() function] is deterministic, for example, but 5355 ** [randomblob|randomblob()] is not. Functions must 5356 ** be deterministic in order to be used in certain contexts such as 5357 ** with the WHERE clause of [partial indexes] or in [generated columns]. 5358 ** SQLite might also optimize deterministic functions by factoring them 5359 ** out of inner loops. 5360 ** </dd> 5361 ** 5362 ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd> 5363 ** The SQLITE_DIRECTONLY flag means that the function may only be invoked 5364 ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in 5365 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5366 ** [expression indexes], [partial indexes], or [generated columns]. 5367 ** The SQLITE_DIRECTONLY flags is a security feature which is recommended 5368 ** for all [application-defined SQL functions], and especially for functions 5369 ** that have side-effects or that could potentially leak sensitive 5370 ** information. 5371 ** </dd> 5372 ** 5373 ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd> 5374 ** The SQLITE_INNOCUOUS flag means that the function is unlikely 5375 ** to cause problems even if misused. An innocuous function should have 5376 ** no side effects and should not depend on any values other than its 5377 ** input parameters. The [abs|abs() function] is an example of an 5378 ** innocuous function. 5379 ** The [load_extension() SQL function] is not innocuous because of its 5380 ** side effects. 5381 ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not 5382 ** exactly the same. The [random|random() function] is an example of a 5383 ** function that is innocuous but not deterministic. 5384 ** <p>Some heightened security settings 5385 ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF]) 5386 ** disable the use of SQL functions inside views and triggers and in 5387 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5388 ** [expression indexes], [partial indexes], and [generated columns] unless 5389 ** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions 5390 ** are innocuous. Developers are advised to avoid using the 5391 ** SQLITE_INNOCUOUS flag for application-defined functions unless the 5392 ** function has been carefully audited and found to be free of potentially 5393 ** security-adverse side-effects and information-leaks. 5394 ** </dd> 5395 ** 5396 ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd> 5397 ** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call 5398 ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5399 ** Specifying this flag makes no difference for scalar or aggregate user 5400 ** functions. However, if it is not specified for a user-defined window 5401 ** function, then any sub-types belonging to arguments passed to the window 5402 ** function may be discarded before the window function is called (i.e. 5403 ** sqlite3_value_subtype() will always return 0). 5404 ** </dd> 5405 ** </dl> 5406 */ 5407 #define SQLITE_DETERMINISTIC 0x000000800 5408 #define SQLITE_DIRECTONLY 0x000080000 5409 #define SQLITE_SUBTYPE 0x000100000 5410 #define SQLITE_INNOCUOUS 0x000200000 5411 5412 /* 5413 ** CAPI3REF: Deprecated Functions 5414 ** DEPRECATED 5415 ** 5416 ** These functions are [deprecated]. In order to maintain 5417 ** backwards compatibility with older code, these functions continue 5418 ** to be supported. However, new applications should avoid 5419 ** the use of these functions. To encourage programmers to avoid 5420 ** these functions, we will not explain what they do. 5421 */ 5422 #ifndef SQLITE_OMIT_DEPRECATED 5423 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5424 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5425 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5426 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 5427 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5428 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5429 void*,sqlite3_int64); 5430 #endif 5431 5432 /* 5433 ** CAPI3REF: Obtaining SQL Values 5434 ** METHOD: sqlite3_value 5435 ** 5436 ** <b>Summary:</b> 5437 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5438 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5439 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5440 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5441 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5442 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5443 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5444 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5445 ** the native byteorder 5446 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5447 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5448 ** <tr><td> <td> <td> 5449 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5450 ** or a UTF-8 TEXT in bytes 5451 ** <tr><td><b>sqlite3_value_bytes16 </b> 5452 ** <td>→ <td>Size of UTF-16 5453 ** TEXT in bytes 5454 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5455 ** datatype of the value 5456 ** <tr><td><b>sqlite3_value_numeric_type </b> 5457 ** <td>→ <td>Best numeric datatype of the value 5458 ** <tr><td><b>sqlite3_value_nochange </b> 5459 ** <td>→ <td>True if the column is unchanged in an UPDATE 5460 ** against a virtual table. 5461 ** <tr><td><b>sqlite3_value_frombind </b> 5462 ** <td>→ <td>True if value originated from a [bound parameter] 5463 ** </table></blockquote> 5464 ** 5465 ** <b>Details:</b> 5466 ** 5467 ** These routines extract type, size, and content information from 5468 ** [protected sqlite3_value] objects. Protected sqlite3_value objects 5469 ** are used to pass parameter information into the functions that 5470 ** implement [application-defined SQL functions] and [virtual tables]. 5471 ** 5472 ** These routines work only with [protected sqlite3_value] objects. 5473 ** Any attempt to use these routines on an [unprotected sqlite3_value] 5474 ** is not threadsafe. 5475 ** 5476 ** ^These routines work just like the corresponding [column access functions] 5477 ** except that these routines take a single [protected sqlite3_value] object 5478 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5479 ** 5480 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5481 ** in the native byte-order of the host machine. ^The 5482 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5483 ** extract UTF-16 strings as big-endian and little-endian respectively. 5484 ** 5485 ** ^If [sqlite3_value] object V was initialized 5486 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5487 ** and if X and Y are strings that compare equal according to strcmp(X,Y), 5488 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5489 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5490 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5491 ** 5492 ** ^(The sqlite3_value_type(V) interface returns the 5493 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5494 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5495 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5496 ** Other interfaces might change the datatype for an sqlite3_value object. 5497 ** For example, if the datatype is initially SQLITE_INTEGER and 5498 ** sqlite3_value_text(V) is called to extract a text value for that 5499 ** integer, then subsequent calls to sqlite3_value_type(V) might return 5500 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5501 ** occurs is undefined and may change from one release of SQLite to the next. 5502 ** 5503 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 5504 ** numeric affinity to the value. This means that an attempt is 5505 ** made to convert the value to an integer or floating point. If 5506 ** such a conversion is possible without loss of information (in other 5507 ** words, if the value is a string that looks like a number) 5508 ** then the conversion is performed. Otherwise no conversion occurs. 5509 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5510 ** 5511 ** ^Within the [xUpdate] method of a [virtual table], the 5512 ** sqlite3_value_nochange(X) interface returns true if and only if 5513 ** the column corresponding to X is unchanged by the UPDATE operation 5514 ** that the xUpdate method call was invoked to implement and if 5515 ** and the prior [xColumn] method call that was invoked to extracted 5516 ** the value for that column returned without setting a result (probably 5517 ** because it queried [sqlite3_vtab_nochange()] and found that the column 5518 ** was unchanging). ^Within an [xUpdate] method, any value for which 5519 ** sqlite3_value_nochange(X) is true will in all other respects appear 5520 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5521 ** than within an [xUpdate] method call for an UPDATE statement, then 5522 ** the return value is arbitrary and meaningless. 5523 ** 5524 ** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5525 ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5526 ** interfaces. ^If X comes from an SQL literal value, or a table column, 5527 ** or an expression, then sqlite3_value_frombind(X) returns zero. 5528 ** 5529 ** Please pay particular attention to the fact that the pointer returned 5530 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5531 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5532 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5533 ** or [sqlite3_value_text16()]. 5534 ** 5535 ** These routines must be called from the same thread as 5536 ** the SQL function that supplied the [sqlite3_value*] parameters. 5537 ** 5538 ** As long as the input parameter is correct, these routines can only 5539 ** fail if an out-of-memory error occurs during a format conversion. 5540 ** Only the following subset of interfaces are subject to out-of-memory 5541 ** errors: 5542 ** 5543 ** <ul> 5544 ** <li> sqlite3_value_blob() 5545 ** <li> sqlite3_value_text() 5546 ** <li> sqlite3_value_text16() 5547 ** <li> sqlite3_value_text16le() 5548 ** <li> sqlite3_value_text16be() 5549 ** <li> sqlite3_value_bytes() 5550 ** <li> sqlite3_value_bytes16() 5551 ** </ul> 5552 ** 5553 ** If an out-of-memory error occurs, then the return value from these 5554 ** routines is the same as if the column had contained an SQL NULL value. 5555 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5556 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5557 ** return value is obtained and before any 5558 ** other SQLite interface is called on the same [database connection]. 5559 */ 5560 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 5561 SQLITE_API double sqlite3_value_double(sqlite3_value*); 5562 SQLITE_API int sqlite3_value_int(sqlite3_value*); 5563 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5564 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 5565 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 5566 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 5567 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 5568 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 5569 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 5570 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 5571 SQLITE_API int sqlite3_value_type(sqlite3_value*); 5572 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 5573 SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 5574 SQLITE_API int sqlite3_value_frombind(sqlite3_value*); 5575 5576 /* 5577 ** CAPI3REF: Finding The Subtype Of SQL Values 5578 ** METHOD: sqlite3_value 5579 ** 5580 ** The sqlite3_value_subtype(V) function returns the subtype for 5581 ** an [application-defined SQL function] argument V. The subtype 5582 ** information can be used to pass a limited amount of context from 5583 ** one SQL function to another. Use the [sqlite3_result_subtype()] 5584 ** routine to set the subtype for the return value of an SQL function. 5585 */ 5586 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 5587 5588 /* 5589 ** CAPI3REF: Copy And Free SQL Values 5590 ** METHOD: sqlite3_value 5591 ** 5592 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5593 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5594 ** is a [protected sqlite3_value] object even if the input is not. 5595 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5596 ** memory allocation fails. ^If V is a [pointer value], then the result 5597 ** of sqlite3_value_dup(V) is a NULL value. 5598 ** 5599 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5600 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5601 ** then sqlite3_value_free(V) is a harmless no-op. 5602 */ 5603 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5604 SQLITE_API void sqlite3_value_free(sqlite3_value*); 5605 5606 /* 5607 ** CAPI3REF: Obtain Aggregate Function Context 5608 ** METHOD: sqlite3_context 5609 ** 5610 ** Implementations of aggregate SQL functions use this 5611 ** routine to allocate memory for storing their state. 5612 ** 5613 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5614 ** for a particular aggregate function, SQLite allocates 5615 ** N bytes of memory, zeroes out that memory, and returns a pointer 5616 ** to the new memory. ^On second and subsequent calls to 5617 ** sqlite3_aggregate_context() for the same aggregate function instance, 5618 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 5619 ** called once for each invocation of the xStep callback and then one 5620 ** last time when the xFinal callback is invoked. ^(When no rows match 5621 ** an aggregate query, the xStep() callback of the aggregate function 5622 ** implementation is never called and xFinal() is called exactly once. 5623 ** In those cases, sqlite3_aggregate_context() might be called for the 5624 ** first time from within xFinal().)^ 5625 ** 5626 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5627 ** when first called if N is less than or equal to zero or if a memory 5628 ** allocate error occurs. 5629 ** 5630 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5631 ** determined by the N parameter on first successful call. Changing the 5632 ** value of N in any subsequent call to sqlite3_aggregate_context() within 5633 ** the same aggregate function instance will not resize the memory 5634 ** allocation.)^ Within the xFinal callback, it is customary to set 5635 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5636 ** pointless memory allocations occur. 5637 ** 5638 ** ^SQLite automatically frees the memory allocated by 5639 ** sqlite3_aggregate_context() when the aggregate query concludes. 5640 ** 5641 ** The first parameter must be a copy of the 5642 ** [sqlite3_context | SQL function context] that is the first parameter 5643 ** to the xStep or xFinal callback routine that implements the aggregate 5644 ** function. 5645 ** 5646 ** This routine must be called from the same thread in which 5647 ** the aggregate SQL function is running. 5648 */ 5649 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5650 5651 /* 5652 ** CAPI3REF: User Data For Functions 5653 ** METHOD: sqlite3_context 5654 ** 5655 ** ^The sqlite3_user_data() interface returns a copy of 5656 ** the pointer that was the pUserData parameter (the 5th parameter) 5657 ** of the [sqlite3_create_function()] 5658 ** and [sqlite3_create_function16()] routines that originally 5659 ** registered the application defined function. 5660 ** 5661 ** This routine must be called from the same thread in which 5662 ** the application-defined function is running. 5663 */ 5664 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 5665 5666 /* 5667 ** CAPI3REF: Database Connection For Functions 5668 ** METHOD: sqlite3_context 5669 ** 5670 ** ^The sqlite3_context_db_handle() interface returns a copy of 5671 ** the pointer to the [database connection] (the 1st parameter) 5672 ** of the [sqlite3_create_function()] 5673 ** and [sqlite3_create_function16()] routines that originally 5674 ** registered the application defined function. 5675 */ 5676 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5677 5678 /* 5679 ** CAPI3REF: Function Auxiliary Data 5680 ** METHOD: sqlite3_context 5681 ** 5682 ** These functions may be used by (non-aggregate) SQL functions to 5683 ** associate metadata with argument values. If the same value is passed to 5684 ** multiple invocations of the same SQL function during query execution, under 5685 ** some circumstances the associated metadata may be preserved. An example 5686 ** of where this might be useful is in a regular-expression matching 5687 ** function. The compiled version of the regular expression can be stored as 5688 ** metadata associated with the pattern string. 5689 ** Then as long as the pattern string remains the same, 5690 ** the compiled regular expression can be reused on multiple 5691 ** invocations of the same function. 5692 ** 5693 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5694 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5695 ** value to the application-defined function. ^N is zero for the left-most 5696 ** function argument. ^If there is no metadata 5697 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5698 ** returns a NULL pointer. 5699 ** 5700 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5701 ** argument of the application-defined function. ^Subsequent 5702 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5703 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5704 ** NULL if the metadata has been discarded. 5705 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5706 ** SQLite will invoke the destructor function X with parameter P exactly 5707 ** once, when the metadata is discarded. 5708 ** SQLite is free to discard the metadata at any time, including: <ul> 5709 ** <li> ^(when the corresponding function parameter changes)^, or 5710 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5711 ** SQL statement)^, or 5712 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5713 ** parameter)^, or 5714 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5715 ** allocation error occurs.)^ </ul> 5716 ** 5717 ** Note the last bullet in particular. The destructor X in 5718 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5719 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5720 ** should be called near the end of the function implementation and the 5721 ** function implementation should not make any use of P after 5722 ** sqlite3_set_auxdata() has been called. 5723 ** 5724 ** ^(In practice, metadata is preserved between function calls for 5725 ** function parameters that are compile-time constants, including literal 5726 ** values and [parameters] and expressions composed from the same.)^ 5727 ** 5728 ** The value of the N parameter to these interfaces should be non-negative. 5729 ** Future enhancements may make use of negative N values to define new 5730 ** kinds of function caching behavior. 5731 ** 5732 ** These routines must be called from the same thread in which 5733 ** the SQL function is running. 5734 */ 5735 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 5736 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5737 5738 5739 /* 5740 ** CAPI3REF: Constants Defining Special Destructor Behavior 5741 ** 5742 ** These are special values for the destructor that is passed in as the 5743 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5744 ** argument is SQLITE_STATIC, it means that the content pointer is constant 5745 ** and will never change. It does not need to be destroyed. ^The 5746 ** SQLITE_TRANSIENT value means that the content will likely change in 5747 ** the near future and that SQLite should make its own private copy of 5748 ** the content before returning. 5749 ** 5750 ** The typedef is necessary to work around problems in certain 5751 ** C++ compilers. 5752 */ 5753 typedef void (*sqlite3_destructor_type)(void*); 5754 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 5755 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5756 5757 /* 5758 ** CAPI3REF: Setting The Result Of An SQL Function 5759 ** METHOD: sqlite3_context 5760 ** 5761 ** These routines are used by the xFunc or xFinal callbacks that 5762 ** implement SQL functions and aggregates. See 5763 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 5764 ** for additional information. 5765 ** 5766 ** These functions work very much like the [parameter binding] family of 5767 ** functions used to bind values to host parameters in prepared statements. 5768 ** Refer to the [SQL parameter] documentation for additional information. 5769 ** 5770 ** ^The sqlite3_result_blob() interface sets the result from 5771 ** an application-defined function to be the BLOB whose content is pointed 5772 ** to by the second parameter and which is N bytes long where N is the 5773 ** third parameter. 5774 ** 5775 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5776 ** interfaces set the result of the application-defined function to be 5777 ** a BLOB containing all zero bytes and N bytes in size. 5778 ** 5779 ** ^The sqlite3_result_double() interface sets the result from 5780 ** an application-defined function to be a floating point value specified 5781 ** by its 2nd argument. 5782 ** 5783 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5784 ** cause the implemented SQL function to throw an exception. 5785 ** ^SQLite uses the string pointed to by the 5786 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5787 ** as the text of an error message. ^SQLite interprets the error 5788 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 5789 ** interprets the string from sqlite3_result_error16() as UTF-16 using 5790 ** the same [byte-order determination rules] as [sqlite3_bind_text16()]. 5791 ** ^If the third parameter to sqlite3_result_error() 5792 ** or sqlite3_result_error16() is negative then SQLite takes as the error 5793 ** message all text up through the first zero character. 5794 ** ^If the third parameter to sqlite3_result_error() or 5795 ** sqlite3_result_error16() is non-negative then SQLite takes that many 5796 ** bytes (not characters) from the 2nd parameter as the error message. 5797 ** ^The sqlite3_result_error() and sqlite3_result_error16() 5798 ** routines make a private copy of the error message text before 5799 ** they return. Hence, the calling function can deallocate or 5800 ** modify the text after they return without harm. 5801 ** ^The sqlite3_result_error_code() function changes the error code 5802 ** returned by SQLite as a result of an error in a function. ^By default, 5803 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5804 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5805 ** 5806 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5807 ** error indicating that a string or BLOB is too long to represent. 5808 ** 5809 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5810 ** error indicating that a memory allocation failed. 5811 ** 5812 ** ^The sqlite3_result_int() interface sets the return value 5813 ** of the application-defined function to be the 32-bit signed integer 5814 ** value given in the 2nd argument. 5815 ** ^The sqlite3_result_int64() interface sets the return value 5816 ** of the application-defined function to be the 64-bit signed integer 5817 ** value given in the 2nd argument. 5818 ** 5819 ** ^The sqlite3_result_null() interface sets the return value 5820 ** of the application-defined function to be NULL. 5821 ** 5822 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 5823 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5824 ** set the return value of the application-defined function to be 5825 ** a text string which is represented as UTF-8, UTF-16 native byte order, 5826 ** UTF-16 little endian, or UTF-16 big endian, respectively. 5827 ** ^The sqlite3_result_text64() interface sets the return value of an 5828 ** application-defined function to be a text string in an encoding 5829 ** specified by the fifth (and last) parameter, which must be one 5830 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5831 ** ^SQLite takes the text result from the application from 5832 ** the 2nd parameter of the sqlite3_result_text* interfaces. 5833 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5834 ** is negative, then SQLite takes result text from the 2nd parameter 5835 ** through the first zero character. 5836 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5837 ** is non-negative, then as many bytes (not characters) of the text 5838 ** pointed to by the 2nd parameter are taken as the application-defined 5839 ** function result. If the 3rd parameter is non-negative, then it 5840 ** must be the byte offset into the string where the NUL terminator would 5841 ** appear if the string where NUL terminated. If any NUL characters occur 5842 ** in the string at a byte offset that is less than the value of the 3rd 5843 ** parameter, then the resulting string will contain embedded NULs and the 5844 ** result of expressions operating on strings with embedded NULs is undefined. 5845 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5846 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5847 ** function as the destructor on the text or BLOB result when it has 5848 ** finished using that result. 5849 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5850 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5851 ** assumes that the text or BLOB result is in constant space and does not 5852 ** copy the content of the parameter nor call a destructor on the content 5853 ** when it has finished using that result. 5854 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5855 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5856 ** then SQLite makes a copy of the result into space obtained 5857 ** from [sqlite3_malloc()] before it returns. 5858 ** 5859 ** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and 5860 ** sqlite3_result_text16be() routines, and for sqlite3_result_text64() 5861 ** when the encoding is not UTF8, if the input UTF16 begins with a 5862 ** byte-order mark (BOM, U+FEFF) then the BOM is removed from the 5863 ** string and the rest of the string is interpreted according to the 5864 ** byte-order specified by the BOM. ^The byte-order specified by 5865 ** the BOM at the beginning of the text overrides the byte-order 5866 ** specified by the interface procedure. ^So, for example, if 5867 ** sqlite3_result_text16le() is invoked with text that begins 5868 ** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the 5869 ** first two bytes of input are skipped and the remaining input 5870 ** is interpreted as UTF16BE text. 5871 ** 5872 ** ^For UTF16 input text to the sqlite3_result_text16(), 5873 ** sqlite3_result_text16be(), sqlite3_result_text16le(), and 5874 ** sqlite3_result_text64() routines, if the text contains invalid 5875 ** UTF16 characters, the invalid characters might be converted 5876 ** into the unicode replacement character, U+FFFD. 5877 ** 5878 ** ^The sqlite3_result_value() interface sets the result of 5879 ** the application-defined function to be a copy of the 5880 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5881 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5882 ** so that the [sqlite3_value] specified in the parameter may change or 5883 ** be deallocated after sqlite3_result_value() returns without harm. 5884 ** ^A [protected sqlite3_value] object may always be used where an 5885 ** [unprotected sqlite3_value] object is required, so either 5886 ** kind of [sqlite3_value] object can be used with this interface. 5887 ** 5888 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5889 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5890 ** also associates the host-language pointer P or type T with that 5891 ** NULL value such that the pointer can be retrieved within an 5892 ** [application-defined SQL function] using [sqlite3_value_pointer()]. 5893 ** ^If the D parameter is not NULL, then it is a pointer to a destructor 5894 ** for the P parameter. ^SQLite invokes D with P as its only argument 5895 ** when SQLite is finished with P. The T parameter should be a static 5896 ** string and preferably a string literal. The sqlite3_result_pointer() 5897 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5898 ** 5899 ** If these routines are called from within the different thread 5900 ** than the one containing the application-defined function that received 5901 ** the [sqlite3_context] pointer, the results are undefined. 5902 */ 5903 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5904 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 5905 sqlite3_uint64,void(*)(void*)); 5906 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 5907 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 5908 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 5909 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 5910 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 5911 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 5912 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 5913 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5914 SQLITE_API void sqlite3_result_null(sqlite3_context*); 5915 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5916 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5917 void(*)(void*), unsigned char encoding); 5918 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5919 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5920 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5921 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5922 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5923 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 5924 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5925 5926 5927 /* 5928 ** CAPI3REF: Setting The Subtype Of An SQL Function 5929 ** METHOD: sqlite3_context 5930 ** 5931 ** The sqlite3_result_subtype(C,T) function causes the subtype of 5932 ** the result from the [application-defined SQL function] with 5933 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 5934 ** of the subtype T are preserved in current versions of SQLite; 5935 ** higher order bits are discarded. 5936 ** The number of subtype bytes preserved by SQLite might increase 5937 ** in future releases of SQLite. 5938 */ 5939 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5940 5941 /* 5942 ** CAPI3REF: Define New Collating Sequences 5943 ** METHOD: sqlite3 5944 ** 5945 ** ^These functions add, remove, or modify a [collation] associated 5946 ** with the [database connection] specified as the first argument. 5947 ** 5948 ** ^The name of the collation is a UTF-8 string 5949 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5950 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5951 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5952 ** considered to be the same name. 5953 ** 5954 ** ^(The third argument (eTextRep) must be one of the constants: 5955 ** <ul> 5956 ** <li> [SQLITE_UTF8], 5957 ** <li> [SQLITE_UTF16LE], 5958 ** <li> [SQLITE_UTF16BE], 5959 ** <li> [SQLITE_UTF16], or 5960 ** <li> [SQLITE_UTF16_ALIGNED]. 5961 ** </ul>)^ 5962 ** ^The eTextRep argument determines the encoding of strings passed 5963 ** to the collating function callback, xCompare. 5964 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5965 ** force strings to be UTF16 with native byte order. 5966 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5967 ** on an even byte address. 5968 ** 5969 ** ^The fourth argument, pArg, is an application data pointer that is passed 5970 ** through as the first argument to the collating function callback. 5971 ** 5972 ** ^The fifth argument, xCompare, is a pointer to the collating function. 5973 ** ^Multiple collating functions can be registered using the same name but 5974 ** with different eTextRep parameters and SQLite will use whichever 5975 ** function requires the least amount of data transformation. 5976 ** ^If the xCompare argument is NULL then the collating function is 5977 ** deleted. ^When all collating functions having the same name are deleted, 5978 ** that collation is no longer usable. 5979 ** 5980 ** ^The collating function callback is invoked with a copy of the pArg 5981 ** application data pointer and with two strings in the encoding specified 5982 ** by the eTextRep argument. The two integer parameters to the collating 5983 ** function callback are the length of the two strings, in bytes. The collating 5984 ** function must return an integer that is negative, zero, or positive 5985 ** if the first string is less than, equal to, or greater than the second, 5986 ** respectively. A collating function must always return the same answer 5987 ** given the same inputs. If two or more collating functions are registered 5988 ** to the same collation name (using different eTextRep values) then all 5989 ** must give an equivalent answer when invoked with equivalent strings. 5990 ** The collating function must obey the following properties for all 5991 ** strings A, B, and C: 5992 ** 5993 ** <ol> 5994 ** <li> If A==B then B==A. 5995 ** <li> If A==B and B==C then A==C. 5996 ** <li> If A<B THEN B>A. 5997 ** <li> If A<B and B<C then A<C. 5998 ** </ol> 5999 ** 6000 ** If a collating function fails any of the above constraints and that 6001 ** collating function is registered and used, then the behavior of SQLite 6002 ** is undefined. 6003 ** 6004 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 6005 ** with the addition that the xDestroy callback is invoked on pArg when 6006 ** the collating function is deleted. 6007 ** ^Collating functions are deleted when they are overridden by later 6008 ** calls to the collation creation functions or when the 6009 ** [database connection] is closed using [sqlite3_close()]. 6010 ** 6011 ** ^The xDestroy callback is <u>not</u> called if the 6012 ** sqlite3_create_collation_v2() function fails. Applications that invoke 6013 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 6014 ** check the return code and dispose of the application data pointer 6015 ** themselves rather than expecting SQLite to deal with it for them. 6016 ** This is different from every other SQLite interface. The inconsistency 6017 ** is unfortunate but cannot be changed without breaking backwards 6018 ** compatibility. 6019 ** 6020 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 6021 */ 6022 SQLITE_API int sqlite3_create_collation( 6023 sqlite3*, 6024 const char *zName, 6025 int eTextRep, 6026 void *pArg, 6027 int(*xCompare)(void*,int,const void*,int,const void*) 6028 ); 6029 SQLITE_API int sqlite3_create_collation_v2( 6030 sqlite3*, 6031 const char *zName, 6032 int eTextRep, 6033 void *pArg, 6034 int(*xCompare)(void*,int,const void*,int,const void*), 6035 void(*xDestroy)(void*) 6036 ); 6037 SQLITE_API int sqlite3_create_collation16( 6038 sqlite3*, 6039 const void *zName, 6040 int eTextRep, 6041 void *pArg, 6042 int(*xCompare)(void*,int,const void*,int,const void*) 6043 ); 6044 6045 /* 6046 ** CAPI3REF: Collation Needed Callbacks 6047 ** METHOD: sqlite3 6048 ** 6049 ** ^To avoid having to register all collation sequences before a database 6050 ** can be used, a single callback function may be registered with the 6051 ** [database connection] to be invoked whenever an undefined collation 6052 ** sequence is required. 6053 ** 6054 ** ^If the function is registered using the sqlite3_collation_needed() API, 6055 ** then it is passed the names of undefined collation sequences as strings 6056 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 6057 ** the names are passed as UTF-16 in machine native byte order. 6058 ** ^A call to either function replaces the existing collation-needed callback. 6059 ** 6060 ** ^(When the callback is invoked, the first argument passed is a copy 6061 ** of the second argument to sqlite3_collation_needed() or 6062 ** sqlite3_collation_needed16(). The second argument is the database 6063 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 6064 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 6065 ** sequence function required. The fourth parameter is the name of the 6066 ** required collation sequence.)^ 6067 ** 6068 ** The callback function should register the desired collation using 6069 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 6070 ** [sqlite3_create_collation_v2()]. 6071 */ 6072 SQLITE_API int sqlite3_collation_needed( 6073 sqlite3*, 6074 void*, 6075 void(*)(void*,sqlite3*,int eTextRep,const char*) 6076 ); 6077 SQLITE_API int sqlite3_collation_needed16( 6078 sqlite3*, 6079 void*, 6080 void(*)(void*,sqlite3*,int eTextRep,const void*) 6081 ); 6082 6083 #ifdef SQLITE_ENABLE_CEROD 6084 /* 6085 ** Specify the activation key for a CEROD database. Unless 6086 ** activated, none of the CEROD routines will work. 6087 */ 6088 SQLITE_API void sqlite3_activate_cerod( 6089 const char *zPassPhrase /* Activation phrase */ 6090 ); 6091 #endif 6092 6093 /* 6094 ** CAPI3REF: Suspend Execution For A Short Time 6095 ** 6096 ** The sqlite3_sleep() function causes the current thread to suspend execution 6097 ** for at least a number of milliseconds specified in its parameter. 6098 ** 6099 ** If the operating system does not support sleep requests with 6100 ** millisecond time resolution, then the time will be rounded up to 6101 ** the nearest second. The number of milliseconds of sleep actually 6102 ** requested from the operating system is returned. 6103 ** 6104 ** ^SQLite implements this interface by calling the xSleep() 6105 ** method of the default [sqlite3_vfs] object. If the xSleep() method 6106 ** of the default VFS is not implemented correctly, or not implemented at 6107 ** all, then the behavior of sqlite3_sleep() may deviate from the description 6108 ** in the previous paragraphs. 6109 */ 6110 SQLITE_API int sqlite3_sleep(int); 6111 6112 /* 6113 ** CAPI3REF: Name Of The Folder Holding Temporary Files 6114 ** 6115 ** ^(If this global variable is made to point to a string which is 6116 ** the name of a folder (a.k.a. directory), then all temporary files 6117 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 6118 ** will be placed in that directory.)^ ^If this variable 6119 ** is a NULL pointer, then SQLite performs a search for an appropriate 6120 ** temporary file directory. 6121 ** 6122 ** Applications are strongly discouraged from using this global variable. 6123 ** It is required to set a temporary folder on Windows Runtime (WinRT). 6124 ** But for all other platforms, it is highly recommended that applications 6125 ** neither read nor write this variable. This global variable is a relic 6126 ** that exists for backwards compatibility of legacy applications and should 6127 ** be avoided in new projects. 6128 ** 6129 ** It is not safe to read or modify this variable in more than one 6130 ** thread at a time. It is not safe to read or modify this variable 6131 ** if a [database connection] is being used at the same time in a separate 6132 ** thread. 6133 ** It is intended that this variable be set once 6134 ** as part of process initialization and before any SQLite interface 6135 ** routines have been called and that this variable remain unchanged 6136 ** thereafter. 6137 ** 6138 ** ^The [temp_store_directory pragma] may modify this variable and cause 6139 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6140 ** the [temp_store_directory pragma] always assumes that any string 6141 ** that this variable points to is held in memory obtained from 6142 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6143 ** using [sqlite3_free]. 6144 ** Hence, if this variable is modified directly, either it should be 6145 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6146 ** or else the use of the [temp_store_directory pragma] should be avoided. 6147 ** Except when requested by the [temp_store_directory pragma], SQLite 6148 ** does not free the memory that sqlite3_temp_directory points to. If 6149 ** the application wants that memory to be freed, it must do 6150 ** so itself, taking care to only do so after all [database connection] 6151 ** objects have been destroyed. 6152 ** 6153 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 6154 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 6155 ** features that require the use of temporary files may fail. Here is an 6156 ** example of how to do this using C++ with the Windows Runtime: 6157 ** 6158 ** <blockquote><pre> 6159 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 6160 ** TemporaryFolder->Path->Data(); 6161 ** char zPathBuf[MAX_PATH + 1]; 6162 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 6163 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 6164 ** NULL, NULL); 6165 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 6166 ** </pre></blockquote> 6167 */ 6168 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 6169 6170 /* 6171 ** CAPI3REF: Name Of The Folder Holding Database Files 6172 ** 6173 ** ^(If this global variable is made to point to a string which is 6174 ** the name of a folder (a.k.a. directory), then all database files 6175 ** specified with a relative pathname and created or accessed by 6176 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 6177 ** to be relative to that directory.)^ ^If this variable is a NULL 6178 ** pointer, then SQLite assumes that all database files specified 6179 ** with a relative pathname are relative to the current directory 6180 ** for the process. Only the windows VFS makes use of this global 6181 ** variable; it is ignored by the unix VFS. 6182 ** 6183 ** Changing the value of this variable while a database connection is 6184 ** open can result in a corrupt database. 6185 ** 6186 ** It is not safe to read or modify this variable in more than one 6187 ** thread at a time. It is not safe to read or modify this variable 6188 ** if a [database connection] is being used at the same time in a separate 6189 ** thread. 6190 ** It is intended that this variable be set once 6191 ** as part of process initialization and before any SQLite interface 6192 ** routines have been called and that this variable remain unchanged 6193 ** thereafter. 6194 ** 6195 ** ^The [data_store_directory pragma] may modify this variable and cause 6196 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6197 ** the [data_store_directory pragma] always assumes that any string 6198 ** that this variable points to is held in memory obtained from 6199 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6200 ** using [sqlite3_free]. 6201 ** Hence, if this variable is modified directly, either it should be 6202 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6203 ** or else the use of the [data_store_directory pragma] should be avoided. 6204 */ 6205 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 6206 6207 /* 6208 ** CAPI3REF: Win32 Specific Interface 6209 ** 6210 ** These interfaces are available only on Windows. The 6211 ** [sqlite3_win32_set_directory] interface is used to set the value associated 6212 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 6213 ** zValue, depending on the value of the type parameter. The zValue parameter 6214 ** should be NULL to cause the previous value to be freed via [sqlite3_free]; 6215 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 6216 ** prior to being used. The [sqlite3_win32_set_directory] interface returns 6217 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 6218 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 6219 ** [sqlite3_data_directory] variable is intended to act as a replacement for 6220 ** the current directory on the sub-platforms of Win32 where that concept is 6221 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 6222 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 6223 ** sqlite3_win32_set_directory interface except the string parameter must be 6224 ** UTF-8 or UTF-16, respectively. 6225 */ 6226 SQLITE_API int sqlite3_win32_set_directory( 6227 unsigned long type, /* Identifier for directory being set or reset */ 6228 void *zValue /* New value for directory being set or reset */ 6229 ); 6230 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 6231 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 6232 6233 /* 6234 ** CAPI3REF: Win32 Directory Types 6235 ** 6236 ** These macros are only available on Windows. They define the allowed values 6237 ** for the type argument to the [sqlite3_win32_set_directory] interface. 6238 */ 6239 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 6240 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 6241 6242 /* 6243 ** CAPI3REF: Test For Auto-Commit Mode 6244 ** KEYWORDS: {autocommit mode} 6245 ** METHOD: sqlite3 6246 ** 6247 ** ^The sqlite3_get_autocommit() interface returns non-zero or 6248 ** zero if the given database connection is or is not in autocommit mode, 6249 ** respectively. ^Autocommit mode is on by default. 6250 ** ^Autocommit mode is disabled by a [BEGIN] statement. 6251 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 6252 ** 6253 ** If certain kinds of errors occur on a statement within a multi-statement 6254 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 6255 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 6256 ** transaction might be rolled back automatically. The only way to 6257 ** find out whether SQLite automatically rolled back the transaction after 6258 ** an error is to use this function. 6259 ** 6260 ** If another thread changes the autocommit status of the database 6261 ** connection while this routine is running, then the return value 6262 ** is undefined. 6263 */ 6264 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 6265 6266 /* 6267 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 6268 ** METHOD: sqlite3_stmt 6269 ** 6270 ** ^The sqlite3_db_handle interface returns the [database connection] handle 6271 ** to which a [prepared statement] belongs. ^The [database connection] 6272 ** returned by sqlite3_db_handle is the same [database connection] 6273 ** that was the first argument 6274 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 6275 ** create the statement in the first place. 6276 */ 6277 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 6278 6279 /* 6280 ** CAPI3REF: Return The Schema Name For A Database Connection 6281 ** METHOD: sqlite3 6282 ** 6283 ** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name 6284 ** for the N-th database on database connection D, or a NULL pointer of N is 6285 ** out of range. An N alue of 0 means the main database file. An N of 1 is 6286 ** the "temp" schema. Larger values of N correspond to various ATTACH-ed 6287 ** databases. 6288 ** 6289 ** Space to hold the string that is returned by sqlite3_db_name() is managed 6290 ** by SQLite itself. The string might be deallocated by any operation that 6291 ** changes the schema, including [ATTACH] or [DETACH] or calls to 6292 ** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that 6293 ** occur on a different thread. Applications that need to 6294 ** remember the string long-term should make their own copy. Applications that 6295 ** are accessing the same database connection simultaneously on multiple 6296 ** threads should mutex-protect calls to this API and should make their own 6297 ** private copy of the result prior to releasing the mutex. 6298 */ 6299 SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N); 6300 6301 /* 6302 ** CAPI3REF: Return The Filename For A Database Connection 6303 ** METHOD: sqlite3 6304 ** 6305 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename 6306 ** associated with database N of connection D. 6307 ** ^If there is no attached database N on the database 6308 ** connection D, or if database N is a temporary or in-memory database, then 6309 ** this function will return either a NULL pointer or an empty string. 6310 ** 6311 ** ^The string value returned by this routine is owned and managed by 6312 ** the database connection. ^The value will be valid until the database N 6313 ** is [DETACH]-ed or until the database connection closes. 6314 ** 6315 ** ^The filename returned by this function is the output of the 6316 ** xFullPathname method of the [VFS]. ^In other words, the filename 6317 ** will be an absolute pathname, even if the filename used 6318 ** to open the database originally was a URI or relative pathname. 6319 ** 6320 ** If the filename pointer returned by this routine is not NULL, then it 6321 ** can be used as the filename input parameter to these routines: 6322 ** <ul> 6323 ** <li> [sqlite3_uri_parameter()] 6324 ** <li> [sqlite3_uri_boolean()] 6325 ** <li> [sqlite3_uri_int64()] 6326 ** <li> [sqlite3_filename_database()] 6327 ** <li> [sqlite3_filename_journal()] 6328 ** <li> [sqlite3_filename_wal()] 6329 ** </ul> 6330 */ 6331 SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 6332 6333 /* 6334 ** CAPI3REF: Determine if a database is read-only 6335 ** METHOD: sqlite3 6336 ** 6337 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 6338 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 6339 ** the name of a database on connection D. 6340 */ 6341 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 6342 6343 /* 6344 ** CAPI3REF: Determine the transaction state of a database 6345 ** METHOD: sqlite3 6346 ** 6347 ** ^The sqlite3_txn_state(D,S) interface returns the current 6348 ** [transaction state] of schema S in database connection D. ^If S is NULL, 6349 ** then the highest transaction state of any schema on database connection D 6350 ** is returned. Transaction states are (in order of lowest to highest): 6351 ** <ol> 6352 ** <li value="0"> SQLITE_TXN_NONE 6353 ** <li value="1"> SQLITE_TXN_READ 6354 ** <li value="2"> SQLITE_TXN_WRITE 6355 ** </ol> 6356 ** ^If the S argument to sqlite3_txn_state(D,S) is not the name of 6357 ** a valid schema, then -1 is returned. 6358 */ 6359 SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema); 6360 6361 /* 6362 ** CAPI3REF: Allowed return values from [sqlite3_txn_state()] 6363 ** KEYWORDS: {transaction state} 6364 ** 6365 ** These constants define the current transaction state of a database file. 6366 ** ^The [sqlite3_txn_state(D,S)] interface returns one of these 6367 ** constants in order to describe the transaction state of schema S 6368 ** in [database connection] D. 6369 ** 6370 ** <dl> 6371 ** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt> 6372 ** <dd>The SQLITE_TXN_NONE state means that no transaction is currently 6373 ** pending.</dd> 6374 ** 6375 ** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt> 6376 ** <dd>The SQLITE_TXN_READ state means that the database is currently 6377 ** in a read transaction. Content has been read from the database file 6378 ** but nothing in the database file has changed. The transaction state 6379 ** will advanced to SQLITE_TXN_WRITE if any changes occur and there are 6380 ** no other conflicting concurrent write transactions. The transaction 6381 ** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or 6382 ** [COMMIT].</dd> 6383 ** 6384 ** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt> 6385 ** <dd>The SQLITE_TXN_WRITE state means that the database is currently 6386 ** in a write transaction. Content has been written to the database file 6387 ** but has not yet committed. The transaction state will change to 6388 ** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd> 6389 */ 6390 #define SQLITE_TXN_NONE 0 6391 #define SQLITE_TXN_READ 1 6392 #define SQLITE_TXN_WRITE 2 6393 6394 /* 6395 ** CAPI3REF: Find the next prepared statement 6396 ** METHOD: sqlite3 6397 ** 6398 ** ^This interface returns a pointer to the next [prepared statement] after 6399 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 6400 ** then this interface returns a pointer to the first prepared statement 6401 ** associated with the database connection pDb. ^If no prepared statement 6402 ** satisfies the conditions of this routine, it returns NULL. 6403 ** 6404 ** The [database connection] pointer D in a call to 6405 ** [sqlite3_next_stmt(D,S)] must refer to an open database 6406 ** connection and in particular must not be a NULL pointer. 6407 */ 6408 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 6409 6410 /* 6411 ** CAPI3REF: Commit And Rollback Notification Callbacks 6412 ** METHOD: sqlite3 6413 ** 6414 ** ^The sqlite3_commit_hook() interface registers a callback 6415 ** function to be invoked whenever a transaction is [COMMIT | committed]. 6416 ** ^Any callback set by a previous call to sqlite3_commit_hook() 6417 ** for the same database connection is overridden. 6418 ** ^The sqlite3_rollback_hook() interface registers a callback 6419 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 6420 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 6421 ** for the same database connection is overridden. 6422 ** ^The pArg argument is passed through to the callback. 6423 ** ^If the callback on a commit hook function returns non-zero, 6424 ** then the commit is converted into a rollback. 6425 ** 6426 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 6427 ** return the P argument from the previous call of the same function 6428 ** on the same [database connection] D, or NULL for 6429 ** the first call for each function on D. 6430 ** 6431 ** The commit and rollback hook callbacks are not reentrant. 6432 ** The callback implementation must not do anything that will modify 6433 ** the database connection that invoked the callback. Any actions 6434 ** to modify the database connection must be deferred until after the 6435 ** completion of the [sqlite3_step()] call that triggered the commit 6436 ** or rollback hook in the first place. 6437 ** Note that running any other SQL statements, including SELECT statements, 6438 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 6439 ** the database connections for the meaning of "modify" in this paragraph. 6440 ** 6441 ** ^Registering a NULL function disables the callback. 6442 ** 6443 ** ^When the commit hook callback routine returns zero, the [COMMIT] 6444 ** operation is allowed to continue normally. ^If the commit hook 6445 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 6446 ** ^The rollback hook is invoked on a rollback that results from a commit 6447 ** hook returning non-zero, just as it would be with any other rollback. 6448 ** 6449 ** ^For the purposes of this API, a transaction is said to have been 6450 ** rolled back if an explicit "ROLLBACK" statement is executed, or 6451 ** an error or constraint causes an implicit rollback to occur. 6452 ** ^The rollback callback is not invoked if a transaction is 6453 ** automatically rolled back because the database connection is closed. 6454 ** 6455 ** See also the [sqlite3_update_hook()] interface. 6456 */ 6457 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 6458 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 6459 6460 /* 6461 ** CAPI3REF: Autovacuum Compaction Amount Callback 6462 ** METHOD: sqlite3 6463 ** 6464 ** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback 6465 ** function C that is invoked prior to each autovacuum of the database 6466 ** file. ^The callback is passed a copy of the generic data pointer (P), 6467 ** the schema-name of the attached database that is being autovacuumed, 6468 ** the the size of the database file in pages, the number of free pages, 6469 ** and the number of bytes per page, respectively. The callback should 6470 ** return the number of free pages that should be removed by the 6471 ** autovacuum. ^If the callback returns zero, then no autovacuum happens. 6472 ** ^If the value returned is greater than or equal to the number of 6473 ** free pages, then a complete autovacuum happens. 6474 ** 6475 ** <p>^If there are multiple ATTACH-ed database files that are being 6476 ** modified as part of a transaction commit, then the autovacuum pages 6477 ** callback is invoked separately for each file. 6478 ** 6479 ** <p><b>The callback is not reentrant.</b> The callback function should 6480 ** not attempt to invoke any other SQLite interface. If it does, bad 6481 ** things may happen, including segmentation faults and corrupt database 6482 ** files. The callback function should be a simple function that 6483 ** does some arithmetic on its input parameters and returns a result. 6484 ** 6485 ** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional 6486 ** destructor for the P parameter. ^If X is not NULL, then X(P) is 6487 ** invoked whenever the database connection closes or when the callback 6488 ** is overwritten by another invocation of sqlite3_autovacuum_pages(). 6489 ** 6490 ** <p>^There is only one autovacuum pages callback per database connection. 6491 ** ^Each call to the sqlite3_autovacuum_pages() interface overrides all 6492 ** previous invocations for that database connection. ^If the callback 6493 ** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer, 6494 ** then the autovacuum steps callback is cancelled. The return value 6495 ** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might 6496 ** be some other error code if something goes wrong. The current 6497 ** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other 6498 ** return codes might be added in future releases. 6499 ** 6500 ** <p>If no autovacuum pages callback is specified (the usual case) or 6501 ** a NULL pointer is provided for the callback, 6502 ** then the default behavior is to vacuum all free pages. So, in other 6503 ** words, the default behavior is the same as if the callback function 6504 ** were something like this: 6505 ** 6506 ** <blockquote><pre> 6507 ** unsigned int demonstration_autovac_pages_callback( 6508 ** void *pClientData, 6509 ** const char *zSchema, 6510 ** unsigned int nDbPage, 6511 ** unsigned int nFreePage, 6512 ** unsigned int nBytePerPage 6513 ** ){ 6514 ** return nFreePage; 6515 ** } 6516 ** </pre></blockquote> 6517 */ 6518 SQLITE_API int sqlite3_autovacuum_pages( 6519 sqlite3 *db, 6520 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int), 6521 void*, 6522 void(*)(void*) 6523 ); 6524 6525 6526 /* 6527 ** CAPI3REF: Data Change Notification Callbacks 6528 ** METHOD: sqlite3 6529 ** 6530 ** ^The sqlite3_update_hook() interface registers a callback function 6531 ** with the [database connection] identified by the first argument 6532 ** to be invoked whenever a row is updated, inserted or deleted in 6533 ** a [rowid table]. 6534 ** ^Any callback set by a previous call to this function 6535 ** for the same database connection is overridden. 6536 ** 6537 ** ^The second argument is a pointer to the function to invoke when a 6538 ** row is updated, inserted or deleted in a rowid table. 6539 ** ^The first argument to the callback is a copy of the third argument 6540 ** to sqlite3_update_hook(). 6541 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 6542 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 6543 ** to be invoked. 6544 ** ^The third and fourth arguments to the callback contain pointers to the 6545 ** database and table name containing the affected row. 6546 ** ^The final callback parameter is the [rowid] of the row. 6547 ** ^In the case of an update, this is the [rowid] after the update takes place. 6548 ** 6549 ** ^(The update hook is not invoked when internal system tables are 6550 ** modified (i.e. sqlite_sequence).)^ 6551 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6552 ** 6553 ** ^In the current implementation, the update hook 6554 ** is not invoked when conflicting rows are deleted because of an 6555 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6556 ** invoked when rows are deleted using the [truncate optimization]. 6557 ** The exceptions defined in this paragraph might change in a future 6558 ** release of SQLite. 6559 ** 6560 ** The update hook implementation must not do anything that will modify 6561 ** the database connection that invoked the update hook. Any actions 6562 ** to modify the database connection must be deferred until after the 6563 ** completion of the [sqlite3_step()] call that triggered the update hook. 6564 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6565 ** database connections for the meaning of "modify" in this paragraph. 6566 ** 6567 ** ^The sqlite3_update_hook(D,C,P) function 6568 ** returns the P argument from the previous call 6569 ** on the same [database connection] D, or NULL for 6570 ** the first call on D. 6571 ** 6572 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6573 ** and [sqlite3_preupdate_hook()] interfaces. 6574 */ 6575 SQLITE_API void *sqlite3_update_hook( 6576 sqlite3*, 6577 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6578 void* 6579 ); 6580 6581 /* 6582 ** CAPI3REF: Enable Or Disable Shared Pager Cache 6583 ** 6584 ** ^(This routine enables or disables the sharing of the database cache 6585 ** and schema data structures between [database connection | connections] 6586 ** to the same database. Sharing is enabled if the argument is true 6587 ** and disabled if the argument is false.)^ 6588 ** 6589 ** ^Cache sharing is enabled and disabled for an entire process. 6590 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6591 ** In prior versions of SQLite, 6592 ** sharing was enabled or disabled for each thread separately. 6593 ** 6594 ** ^(The cache sharing mode set by this interface effects all subsequent 6595 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6596 ** Existing database connections continue to use the sharing mode 6597 ** that was in effect at the time they were opened.)^ 6598 ** 6599 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6600 ** successfully. An [error code] is returned otherwise.)^ 6601 ** 6602 ** ^Shared cache is disabled by default. It is recommended that it stay 6603 ** that way. In other words, do not use this routine. This interface 6604 ** continues to be provided for historical compatibility, but its use is 6605 ** discouraged. Any use of shared cache is discouraged. If shared cache 6606 ** must be used, it is recommended that shared cache only be enabled for 6607 ** individual database connections using the [sqlite3_open_v2()] interface 6608 ** with the [SQLITE_OPEN_SHAREDCACHE] flag. 6609 ** 6610 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6611 ** and will always return SQLITE_MISUSE. On those systems, 6612 ** shared cache mode should be enabled per-database connection via 6613 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6614 ** 6615 ** This interface is threadsafe on processors where writing a 6616 ** 32-bit integer is atomic. 6617 ** 6618 ** See Also: [SQLite Shared-Cache Mode] 6619 */ 6620 SQLITE_API int sqlite3_enable_shared_cache(int); 6621 6622 /* 6623 ** CAPI3REF: Attempt To Free Heap Memory 6624 ** 6625 ** ^The sqlite3_release_memory() interface attempts to free N bytes 6626 ** of heap memory by deallocating non-essential memory allocations 6627 ** held by the database library. Memory used to cache database 6628 ** pages to improve performance is an example of non-essential memory. 6629 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 6630 ** which might be more or less than the amount requested. 6631 ** ^The sqlite3_release_memory() routine is a no-op returning zero 6632 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6633 ** 6634 ** See also: [sqlite3_db_release_memory()] 6635 */ 6636 SQLITE_API int sqlite3_release_memory(int); 6637 6638 /* 6639 ** CAPI3REF: Free Memory Used By A Database Connection 6640 ** METHOD: sqlite3 6641 ** 6642 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6643 ** memory as possible from database connection D. Unlike the 6644 ** [sqlite3_release_memory()] interface, this interface is in effect even 6645 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6646 ** omitted. 6647 ** 6648 ** See also: [sqlite3_release_memory()] 6649 */ 6650 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 6651 6652 /* 6653 ** CAPI3REF: Impose A Limit On Heap Size 6654 ** 6655 ** These interfaces impose limits on the amount of heap memory that will be 6656 ** by all database connections within a single process. 6657 ** 6658 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6659 ** soft limit on the amount of heap memory that may be allocated by SQLite. 6660 ** ^SQLite strives to keep heap memory utilization below the soft heap 6661 ** limit by reducing the number of pages held in the page cache 6662 ** as heap memory usages approaches the limit. 6663 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 6664 ** below the limit, it will exceed the limit rather than generate 6665 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6666 ** is advisory only. 6667 ** 6668 ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of 6669 ** N bytes on the amount of memory that will be allocated. ^The 6670 ** sqlite3_hard_heap_limit64(N) interface is similar to 6671 ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail 6672 ** when the hard heap limit is reached. 6673 ** 6674 ** ^The return value from both sqlite3_soft_heap_limit64() and 6675 ** sqlite3_hard_heap_limit64() is the size of 6676 ** the heap limit prior to the call, or negative in the case of an 6677 ** error. ^If the argument N is negative 6678 ** then no change is made to the heap limit. Hence, the current 6679 ** size of heap limits can be determined by invoking 6680 ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). 6681 ** 6682 ** ^Setting the heap limits to zero disables the heap limiter mechanism. 6683 ** 6684 ** ^The soft heap limit may not be greater than the hard heap limit. 6685 ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) 6686 ** is invoked with a value of N that is greater than the hard heap limit, 6687 ** the the soft heap limit is set to the value of the hard heap limit. 6688 ** ^The soft heap limit is automatically enabled whenever the hard heap 6689 ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and 6690 ** the soft heap limit is outside the range of 1..N, then the soft heap 6691 ** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the 6692 ** hard heap limit is enabled makes the soft heap limit equal to the 6693 ** hard heap limit. 6694 ** 6695 ** The memory allocation limits can also be adjusted using 6696 ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 6697 ** 6698 ** ^(The heap limits are not enforced in the current implementation 6699 ** if one or more of following conditions are true: 6700 ** 6701 ** <ul> 6702 ** <li> The limit value is set to zero. 6703 ** <li> Memory accounting is disabled using a combination of the 6704 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6705 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6706 ** <li> An alternative page cache implementation is specified using 6707 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6708 ** <li> The page cache allocates from its own memory pool supplied 6709 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6710 ** from the heap. 6711 ** </ul>)^ 6712 ** 6713 ** The circumstances under which SQLite will enforce the heap limits may 6714 ** changes in future releases of SQLite. 6715 */ 6716 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6717 SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 6718 6719 /* 6720 ** CAPI3REF: Deprecated Soft Heap Limit Interface 6721 ** DEPRECATED 6722 ** 6723 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6724 ** interface. This routine is provided for historical compatibility 6725 ** only. All new applications should use the 6726 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 6727 */ 6728 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6729 6730 6731 /* 6732 ** CAPI3REF: Extract Metadata About A Column Of A Table 6733 ** METHOD: sqlite3 6734 ** 6735 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6736 ** information about column C of table T in database D 6737 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6738 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 6739 ** the final five arguments with appropriate values if the specified 6740 ** column exists. ^The sqlite3_table_column_metadata() interface returns 6741 ** SQLITE_ERROR if the specified column does not exist. 6742 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6743 ** NULL pointer, then this routine simply checks for the existence of the 6744 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6745 ** does not. If the table name parameter T in a call to 6746 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6747 ** undefined behavior. 6748 ** 6749 ** ^The column is identified by the second, third and fourth parameters to 6750 ** this function. ^(The second parameter is either the name of the database 6751 ** (i.e. "main", "temp", or an attached database) containing the specified 6752 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6753 ** for the table using the same algorithm used by the database engine to 6754 ** resolve unqualified table references. 6755 ** 6756 ** ^The third and fourth parameters to this function are the table and column 6757 ** name of the desired column, respectively. 6758 ** 6759 ** ^Metadata is returned by writing to the memory locations passed as the 5th 6760 ** and subsequent parameters to this function. ^Any of these arguments may be 6761 ** NULL, in which case the corresponding element of metadata is omitted. 6762 ** 6763 ** ^(<blockquote> 6764 ** <table border="1"> 6765 ** <tr><th> Parameter <th> Output<br>Type <th> Description 6766 ** 6767 ** <tr><td> 5th <td> const char* <td> Data type 6768 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6769 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6770 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6771 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6772 ** </table> 6773 ** </blockquote>)^ 6774 ** 6775 ** ^The memory pointed to by the character pointers returned for the 6776 ** declaration type and collation sequence is valid until the next 6777 ** call to any SQLite API function. 6778 ** 6779 ** ^If the specified table is actually a view, an [error code] is returned. 6780 ** 6781 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6782 ** is not a [WITHOUT ROWID] table and an 6783 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6784 ** parameters are set for the explicitly declared column. ^(If there is no 6785 ** [INTEGER PRIMARY KEY] column, then the outputs 6786 ** for the [rowid] are set as follows: 6787 ** 6788 ** <pre> 6789 ** data type: "INTEGER" 6790 ** collation sequence: "BINARY" 6791 ** not null: 0 6792 ** primary key: 1 6793 ** auto increment: 0 6794 ** </pre>)^ 6795 ** 6796 ** ^This function causes all database schemas to be read from disk and 6797 ** parsed, if that has not already been done, and returns an error if 6798 ** any errors are encountered while loading the schema. 6799 */ 6800 SQLITE_API int sqlite3_table_column_metadata( 6801 sqlite3 *db, /* Connection handle */ 6802 const char *zDbName, /* Database name or NULL */ 6803 const char *zTableName, /* Table name */ 6804 const char *zColumnName, /* Column name */ 6805 char const **pzDataType, /* OUTPUT: Declared data type */ 6806 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6807 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6808 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6809 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6810 ); 6811 6812 /* 6813 ** CAPI3REF: Load An Extension 6814 ** METHOD: sqlite3 6815 ** 6816 ** ^This interface loads an SQLite extension library from the named file. 6817 ** 6818 ** ^The sqlite3_load_extension() interface attempts to load an 6819 ** [SQLite extension] library contained in the file zFile. If 6820 ** the file cannot be loaded directly, attempts are made to load 6821 ** with various operating-system specific extensions added. 6822 ** So for example, if "samplelib" cannot be loaded, then names like 6823 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6824 ** be tried also. 6825 ** 6826 ** ^The entry point is zProc. 6827 ** ^(zProc may be 0, in which case SQLite will try to come up with an 6828 ** entry point name on its own. It first tries "sqlite3_extension_init". 6829 ** If that does not work, it constructs a name "sqlite3_X_init" where the 6830 ** X is consists of the lower-case equivalent of all ASCII alphabetic 6831 ** characters in the filename from the last "/" to the first following 6832 ** "." and omitting any initial "lib".)^ 6833 ** ^The sqlite3_load_extension() interface returns 6834 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6835 ** ^If an error occurs and pzErrMsg is not 0, then the 6836 ** [sqlite3_load_extension()] interface shall attempt to 6837 ** fill *pzErrMsg with error message text stored in memory 6838 ** obtained from [sqlite3_malloc()]. The calling function 6839 ** should free this memory by calling [sqlite3_free()]. 6840 ** 6841 ** ^Extension loading must be enabled using 6842 ** [sqlite3_enable_load_extension()] or 6843 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6844 ** prior to calling this API, 6845 ** otherwise an error will be returned. 6846 ** 6847 ** <b>Security warning:</b> It is recommended that the 6848 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6849 ** interface. The use of the [sqlite3_enable_load_extension()] interface 6850 ** should be avoided. This will keep the SQL function [load_extension()] 6851 ** disabled and prevent SQL injections from giving attackers 6852 ** access to extension loading capabilities. 6853 ** 6854 ** See also the [load_extension() SQL function]. 6855 */ 6856 SQLITE_API int sqlite3_load_extension( 6857 sqlite3 *db, /* Load the extension into this database connection */ 6858 const char *zFile, /* Name of the shared library containing extension */ 6859 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6860 char **pzErrMsg /* Put error message here if not 0 */ 6861 ); 6862 6863 /* 6864 ** CAPI3REF: Enable Or Disable Extension Loading 6865 ** METHOD: sqlite3 6866 ** 6867 ** ^So as not to open security holes in older applications that are 6868 ** unprepared to deal with [extension loading], and as a means of disabling 6869 ** [extension loading] while evaluating user-entered SQL, the following API 6870 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6871 ** 6872 ** ^Extension loading is off by default. 6873 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6874 ** to turn extension loading on and call it with onoff==0 to turn 6875 ** it back off again. 6876 ** 6877 ** ^This interface enables or disables both the C-API 6878 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6879 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6880 ** to enable or disable only the C-API.)^ 6881 ** 6882 ** <b>Security warning:</b> It is recommended that extension loading 6883 ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6884 ** rather than this interface, so the [load_extension()] SQL function 6885 ** remains disabled. This will prevent SQL injections from giving attackers 6886 ** access to extension loading capabilities. 6887 */ 6888 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6889 6890 /* 6891 ** CAPI3REF: Automatically Load Statically Linked Extensions 6892 ** 6893 ** ^This interface causes the xEntryPoint() function to be invoked for 6894 ** each new [database connection] that is created. The idea here is that 6895 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6896 ** that is to be automatically loaded into all new database connections. 6897 ** 6898 ** ^(Even though the function prototype shows that xEntryPoint() takes 6899 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 6900 ** arguments and expects an integer result as if the signature of the 6901 ** entry point where as follows: 6902 ** 6903 ** <blockquote><pre> 6904 ** int xEntryPoint( 6905 ** sqlite3 *db, 6906 ** const char **pzErrMsg, 6907 ** const struct sqlite3_api_routines *pThunk 6908 ** ); 6909 ** </pre></blockquote>)^ 6910 ** 6911 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6912 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6913 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6914 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6915 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6916 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6917 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6918 ** 6919 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6920 ** on the list of automatic extensions is a harmless no-op. ^No entry point 6921 ** will be called more than once for each database connection that is opened. 6922 ** 6923 ** See also: [sqlite3_reset_auto_extension()] 6924 ** and [sqlite3_cancel_auto_extension()] 6925 */ 6926 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6927 6928 /* 6929 ** CAPI3REF: Cancel Automatic Extension Loading 6930 ** 6931 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6932 ** initialization routine X that was registered using a prior call to 6933 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6934 ** routine returns 1 if initialization routine X was successfully 6935 ** unregistered and it returns 0 if X was not on the list of initialization 6936 ** routines. 6937 */ 6938 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6939 6940 /* 6941 ** CAPI3REF: Reset Automatic Extension Loading 6942 ** 6943 ** ^This interface disables all automatic extensions previously 6944 ** registered using [sqlite3_auto_extension()]. 6945 */ 6946 SQLITE_API void sqlite3_reset_auto_extension(void); 6947 6948 /* 6949 ** The interface to the virtual-table mechanism is currently considered 6950 ** to be experimental. The interface might change in incompatible ways. 6951 ** If this is a problem for you, do not use the interface at this time. 6952 ** 6953 ** When the virtual-table mechanism stabilizes, we will declare the 6954 ** interface fixed, support it indefinitely, and remove this comment. 6955 */ 6956 6957 /* 6958 ** Structures used by the virtual table interface 6959 */ 6960 typedef struct sqlite3_vtab sqlite3_vtab; 6961 typedef struct sqlite3_index_info sqlite3_index_info; 6962 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6963 typedef struct sqlite3_module sqlite3_module; 6964 6965 /* 6966 ** CAPI3REF: Virtual Table Object 6967 ** KEYWORDS: sqlite3_module {virtual table module} 6968 ** 6969 ** This structure, sometimes called a "virtual table module", 6970 ** defines the implementation of a [virtual table]. 6971 ** This structure consists mostly of methods for the module. 6972 ** 6973 ** ^A virtual table module is created by filling in a persistent 6974 ** instance of this structure and passing a pointer to that instance 6975 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6976 ** ^The registration remains valid until it is replaced by a different 6977 ** module or until the [database connection] closes. The content 6978 ** of this structure must not change while it is registered with 6979 ** any database connection. 6980 */ 6981 struct sqlite3_module { 6982 int iVersion; 6983 int (*xCreate)(sqlite3*, void *pAux, 6984 int argc, const char *const*argv, 6985 sqlite3_vtab **ppVTab, char**); 6986 int (*xConnect)(sqlite3*, void *pAux, 6987 int argc, const char *const*argv, 6988 sqlite3_vtab **ppVTab, char**); 6989 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6990 int (*xDisconnect)(sqlite3_vtab *pVTab); 6991 int (*xDestroy)(sqlite3_vtab *pVTab); 6992 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6993 int (*xClose)(sqlite3_vtab_cursor*); 6994 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6995 int argc, sqlite3_value **argv); 6996 int (*xNext)(sqlite3_vtab_cursor*); 6997 int (*xEof)(sqlite3_vtab_cursor*); 6998 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6999 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 7000 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 7001 int (*xBegin)(sqlite3_vtab *pVTab); 7002 int (*xSync)(sqlite3_vtab *pVTab); 7003 int (*xCommit)(sqlite3_vtab *pVTab); 7004 int (*xRollback)(sqlite3_vtab *pVTab); 7005 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 7006 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 7007 void **ppArg); 7008 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 7009 /* The methods above are in version 1 of the sqlite_module object. Those 7010 ** below are for version 2 and greater. */ 7011 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 7012 int (*xRelease)(sqlite3_vtab *pVTab, int); 7013 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 7014 /* The methods above are in versions 1 and 2 of the sqlite_module object. 7015 ** Those below are for version 3 and greater. */ 7016 int (*xShadowName)(const char*); 7017 }; 7018 7019 /* 7020 ** CAPI3REF: Virtual Table Indexing Information 7021 ** KEYWORDS: sqlite3_index_info 7022 ** 7023 ** The sqlite3_index_info structure and its substructures is used as part 7024 ** of the [virtual table] interface to 7025 ** pass information into and receive the reply from the [xBestIndex] 7026 ** method of a [virtual table module]. The fields under **Inputs** are the 7027 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 7028 ** results into the **Outputs** fields. 7029 ** 7030 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 7031 ** 7032 ** <blockquote>column OP expr</blockquote> 7033 ** 7034 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 7035 ** stored in aConstraint[].op using one of the 7036 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 7037 ** ^(The index of the column is stored in 7038 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 7039 ** expr on the right-hand side can be evaluated (and thus the constraint 7040 ** is usable) and false if it cannot.)^ 7041 ** 7042 ** ^The optimizer automatically inverts terms of the form "expr OP column" 7043 ** and makes other simplifications to the WHERE clause in an attempt to 7044 ** get as many WHERE clause terms into the form shown above as possible. 7045 ** ^The aConstraint[] array only reports WHERE clause terms that are 7046 ** relevant to the particular virtual table being queried. 7047 ** 7048 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 7049 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 7050 ** 7051 ** The colUsed field indicates which columns of the virtual table may be 7052 ** required by the current scan. Virtual table columns are numbered from 7053 ** zero in the order in which they appear within the CREATE TABLE statement 7054 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 7055 ** the corresponding bit is set within the colUsed mask if the column may be 7056 ** required by SQLite. If the table has at least 64 columns and any column 7057 ** to the right of the first 63 is required, then bit 63 of colUsed is also 7058 ** set. In other words, column iCol may be required if the expression 7059 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 7060 ** non-zero. 7061 ** 7062 ** The [xBestIndex] method must fill aConstraintUsage[] with information 7063 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 7064 ** the right-hand side of the corresponding aConstraint[] is evaluated 7065 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 7066 ** is true, then the constraint is assumed to be fully handled by the 7067 ** virtual table and might not be checked again by the byte code.)^ ^(The 7068 ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag 7069 ** is left in its default setting of false, the constraint will always be 7070 ** checked separately in byte code. If the omit flag is change to true, then 7071 ** the constraint may or may not be checked in byte code. In other words, 7072 ** when the omit flag is true there is no guarantee that the constraint will 7073 ** not be checked again using byte code.)^ 7074 ** 7075 ** ^The idxNum and idxPtr values are recorded and passed into the 7076 ** [xFilter] method. 7077 ** ^[sqlite3_free()] is used to free idxPtr if and only if 7078 ** needToFreeIdxPtr is true. 7079 ** 7080 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 7081 ** the correct order to satisfy the ORDER BY clause so that no separate 7082 ** sorting step is required. 7083 ** 7084 ** ^The estimatedCost value is an estimate of the cost of a particular 7085 ** strategy. A cost of N indicates that the cost of the strategy is similar 7086 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 7087 ** indicates that the expense of the operation is similar to that of a 7088 ** binary search on a unique indexed field of an SQLite table with N rows. 7089 ** 7090 ** ^The estimatedRows value is an estimate of the number of rows that 7091 ** will be returned by the strategy. 7092 ** 7093 ** The xBestIndex method may optionally populate the idxFlags field with a 7094 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 7095 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 7096 ** assumes that the strategy may visit at most one row. 7097 ** 7098 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 7099 ** SQLite also assumes that if a call to the xUpdate() method is made as 7100 ** part of the same statement to delete or update a virtual table row and the 7101 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 7102 ** any database changes. In other words, if the xUpdate() returns 7103 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 7104 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 7105 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 7106 ** the xUpdate method are automatically rolled back by SQLite. 7107 ** 7108 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 7109 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 7110 ** If a virtual table extension is 7111 ** used with an SQLite version earlier than 3.8.2, the results of attempting 7112 ** to read or write the estimatedRows field are undefined (but are likely 7113 ** to include crashing the application). The estimatedRows field should 7114 ** therefore only be used if [sqlite3_libversion_number()] returns a 7115 ** value greater than or equal to 3008002. Similarly, the idxFlags field 7116 ** was added for [version 3.9.0] ([dateof:3.9.0]). 7117 ** It may therefore only be used if 7118 ** sqlite3_libversion_number() returns a value greater than or equal to 7119 ** 3009000. 7120 */ 7121 struct sqlite3_index_info { 7122 /* Inputs */ 7123 int nConstraint; /* Number of entries in aConstraint */ 7124 struct sqlite3_index_constraint { 7125 int iColumn; /* Column constrained. -1 for ROWID */ 7126 unsigned char op; /* Constraint operator */ 7127 unsigned char usable; /* True if this constraint is usable */ 7128 int iTermOffset; /* Used internally - xBestIndex should ignore */ 7129 } *aConstraint; /* Table of WHERE clause constraints */ 7130 int nOrderBy; /* Number of terms in the ORDER BY clause */ 7131 struct sqlite3_index_orderby { 7132 int iColumn; /* Column number */ 7133 unsigned char desc; /* True for DESC. False for ASC. */ 7134 } *aOrderBy; /* The ORDER BY clause */ 7135 /* Outputs */ 7136 struct sqlite3_index_constraint_usage { 7137 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 7138 unsigned char omit; /* Do not code a test for this constraint */ 7139 } *aConstraintUsage; 7140 int idxNum; /* Number used to identify the index */ 7141 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 7142 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 7143 int orderByConsumed; /* True if output is already ordered */ 7144 double estimatedCost; /* Estimated cost of using this index */ 7145 /* Fields below are only available in SQLite 3.8.2 and later */ 7146 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 7147 /* Fields below are only available in SQLite 3.9.0 and later */ 7148 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 7149 /* Fields below are only available in SQLite 3.10.0 and later */ 7150 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 7151 }; 7152 7153 /* 7154 ** CAPI3REF: Virtual Table Scan Flags 7155 ** 7156 ** Virtual table implementations are allowed to set the 7157 ** [sqlite3_index_info].idxFlags field to some combination of 7158 ** these bits. 7159 */ 7160 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 7161 7162 /* 7163 ** CAPI3REF: Virtual Table Constraint Operator Codes 7164 ** 7165 ** These macros define the allowed values for the 7166 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 7167 ** an operator that is part of a constraint term in the WHERE clause of 7168 ** a query that uses a [virtual table]. 7169 ** 7170 ** ^The left-hand operand of the operator is given by the corresponding 7171 ** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand 7172 ** operand is the rowid. 7173 ** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET 7174 ** operators have no left-hand operand, and so for those operators the 7175 ** corresponding aConstraint[].iColumn is meaningless and should not be 7176 ** used. 7177 ** 7178 ** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through 7179 ** value 255 are reserved to represent functions that are overloaded 7180 ** by the [xFindFunction|xFindFunction method] of the virtual table 7181 ** implementation. 7182 ** 7183 ** The right-hand operands for each constraint might be accessible using 7184 ** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand 7185 ** operand is only available if it appears as a single constant literal 7186 ** in the input SQL. If the right-hand operand is another column or an 7187 ** expression (even a constant expression) or a parameter, then the 7188 ** sqlite3_vtab_rhs_value() probably will not be able to extract it. 7189 ** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and 7190 ** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand 7191 ** and hence calls to sqlite3_vtab_rhs_value() for those operators will 7192 ** always return SQLITE_NOTFOUND. 7193 ** 7194 ** The collating sequence to be used for comparison can be found using 7195 ** the [sqlite3_vtab_collation()] interface. For most real-world virtual 7196 ** tables, the collating sequence of constraints does not matter (for example 7197 ** because the constraints are numeric) and so the sqlite3_vtab_collation() 7198 ** interface is no commonly needed. 7199 */ 7200 #define SQLITE_INDEX_CONSTRAINT_EQ 2 7201 #define SQLITE_INDEX_CONSTRAINT_GT 4 7202 #define SQLITE_INDEX_CONSTRAINT_LE 8 7203 #define SQLITE_INDEX_CONSTRAINT_LT 16 7204 #define SQLITE_INDEX_CONSTRAINT_GE 32 7205 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 7206 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 7207 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 7208 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 7209 #define SQLITE_INDEX_CONSTRAINT_NE 68 7210 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69 7211 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 7212 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71 7213 #define SQLITE_INDEX_CONSTRAINT_IS 72 7214 #define SQLITE_INDEX_CONSTRAINT_LIMIT 73 7215 #define SQLITE_INDEX_CONSTRAINT_OFFSET 74 7216 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 7217 7218 /* 7219 ** CAPI3REF: Register A Virtual Table Implementation 7220 ** METHOD: sqlite3 7221 ** 7222 ** ^These routines are used to register a new [virtual table module] name. 7223 ** ^Module names must be registered before 7224 ** creating a new [virtual table] using the module and before using a 7225 ** preexisting [virtual table] for the module. 7226 ** 7227 ** ^The module name is registered on the [database connection] specified 7228 ** by the first parameter. ^The name of the module is given by the 7229 ** second parameter. ^The third parameter is a pointer to 7230 ** the implementation of the [virtual table module]. ^The fourth 7231 ** parameter is an arbitrary client data pointer that is passed through 7232 ** into the [xCreate] and [xConnect] methods of the virtual table module 7233 ** when a new virtual table is be being created or reinitialized. 7234 ** 7235 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 7236 ** is a pointer to a destructor for the pClientData. ^SQLite will 7237 ** invoke the destructor function (if it is not NULL) when SQLite 7238 ** no longer needs the pClientData pointer. ^The destructor will also 7239 ** be invoked if the call to sqlite3_create_module_v2() fails. 7240 ** ^The sqlite3_create_module() 7241 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 7242 ** destructor. 7243 ** 7244 ** ^If the third parameter (the pointer to the sqlite3_module object) is 7245 ** NULL then no new module is created and any existing modules with the 7246 ** same name are dropped. 7247 ** 7248 ** See also: [sqlite3_drop_modules()] 7249 */ 7250 SQLITE_API int sqlite3_create_module( 7251 sqlite3 *db, /* SQLite connection to register module with */ 7252 const char *zName, /* Name of the module */ 7253 const sqlite3_module *p, /* Methods for the module */ 7254 void *pClientData /* Client data for xCreate/xConnect */ 7255 ); 7256 SQLITE_API int sqlite3_create_module_v2( 7257 sqlite3 *db, /* SQLite connection to register module with */ 7258 const char *zName, /* Name of the module */ 7259 const sqlite3_module *p, /* Methods for the module */ 7260 void *pClientData, /* Client data for xCreate/xConnect */ 7261 void(*xDestroy)(void*) /* Module destructor function */ 7262 ); 7263 7264 /* 7265 ** CAPI3REF: Remove Unnecessary Virtual Table Implementations 7266 ** METHOD: sqlite3 7267 ** 7268 ** ^The sqlite3_drop_modules(D,L) interface removes all virtual 7269 ** table modules from database connection D except those named on list L. 7270 ** The L parameter must be either NULL or a pointer to an array of pointers 7271 ** to strings where the array is terminated by a single NULL pointer. 7272 ** ^If the L parameter is NULL, then all virtual table modules are removed. 7273 ** 7274 ** See also: [sqlite3_create_module()] 7275 */ 7276 SQLITE_API int sqlite3_drop_modules( 7277 sqlite3 *db, /* Remove modules from this connection */ 7278 const char **azKeep /* Except, do not remove the ones named here */ 7279 ); 7280 7281 /* 7282 ** CAPI3REF: Virtual Table Instance Object 7283 ** KEYWORDS: sqlite3_vtab 7284 ** 7285 ** Every [virtual table module] implementation uses a subclass 7286 ** of this object to describe a particular instance 7287 ** of the [virtual table]. Each subclass will 7288 ** be tailored to the specific needs of the module implementation. 7289 ** The purpose of this superclass is to define certain fields that are 7290 ** common to all module implementations. 7291 ** 7292 ** ^Virtual tables methods can set an error message by assigning a 7293 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 7294 ** take care that any prior string is freed by a call to [sqlite3_free()] 7295 ** prior to assigning a new string to zErrMsg. ^After the error message 7296 ** is delivered up to the client application, the string will be automatically 7297 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 7298 */ 7299 struct sqlite3_vtab { 7300 const sqlite3_module *pModule; /* The module for this virtual table */ 7301 int nRef; /* Number of open cursors */ 7302 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 7303 /* Virtual table implementations will typically add additional fields */ 7304 }; 7305 7306 /* 7307 ** CAPI3REF: Virtual Table Cursor Object 7308 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 7309 ** 7310 ** Every [virtual table module] implementation uses a subclass of the 7311 ** following structure to describe cursors that point into the 7312 ** [virtual table] and are used 7313 ** to loop through the virtual table. Cursors are created using the 7314 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 7315 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 7316 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 7317 ** of the module. Each module implementation will define 7318 ** the content of a cursor structure to suit its own needs. 7319 ** 7320 ** This superclass exists in order to define fields of the cursor that 7321 ** are common to all implementations. 7322 */ 7323 struct sqlite3_vtab_cursor { 7324 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 7325 /* Virtual table implementations will typically add additional fields */ 7326 }; 7327 7328 /* 7329 ** CAPI3REF: Declare The Schema Of A Virtual Table 7330 ** 7331 ** ^The [xCreate] and [xConnect] methods of a 7332 ** [virtual table module] call this interface 7333 ** to declare the format (the names and datatypes of the columns) of 7334 ** the virtual tables they implement. 7335 */ 7336 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 7337 7338 /* 7339 ** CAPI3REF: Overload A Function For A Virtual Table 7340 ** METHOD: sqlite3 7341 ** 7342 ** ^(Virtual tables can provide alternative implementations of functions 7343 ** using the [xFindFunction] method of the [virtual table module]. 7344 ** But global versions of those functions 7345 ** must exist in order to be overloaded.)^ 7346 ** 7347 ** ^(This API makes sure a global version of a function with a particular 7348 ** name and number of parameters exists. If no such function exists 7349 ** before this API is called, a new function is created.)^ ^The implementation 7350 ** of the new function always causes an exception to be thrown. So 7351 ** the new function is not good for anything by itself. Its only 7352 ** purpose is to be a placeholder function that can be overloaded 7353 ** by a [virtual table]. 7354 */ 7355 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 7356 7357 /* 7358 ** The interface to the virtual-table mechanism defined above (back up 7359 ** to a comment remarkably similar to this one) is currently considered 7360 ** to be experimental. The interface might change in incompatible ways. 7361 ** If this is a problem for you, do not use the interface at this time. 7362 ** 7363 ** When the virtual-table mechanism stabilizes, we will declare the 7364 ** interface fixed, support it indefinitely, and remove this comment. 7365 */ 7366 7367 /* 7368 ** CAPI3REF: A Handle To An Open BLOB 7369 ** KEYWORDS: {BLOB handle} {BLOB handles} 7370 ** 7371 ** An instance of this object represents an open BLOB on which 7372 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 7373 ** ^Objects of this type are created by [sqlite3_blob_open()] 7374 ** and destroyed by [sqlite3_blob_close()]. 7375 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 7376 ** can be used to read or write small subsections of the BLOB. 7377 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 7378 */ 7379 typedef struct sqlite3_blob sqlite3_blob; 7380 7381 /* 7382 ** CAPI3REF: Open A BLOB For Incremental I/O 7383 ** METHOD: sqlite3 7384 ** CONSTRUCTOR: sqlite3_blob 7385 ** 7386 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 7387 ** in row iRow, column zColumn, table zTable in database zDb; 7388 ** in other words, the same BLOB that would be selected by: 7389 ** 7390 ** <pre> 7391 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 7392 ** </pre>)^ 7393 ** 7394 ** ^(Parameter zDb is not the filename that contains the database, but 7395 ** rather the symbolic name of the database. For attached databases, this is 7396 ** the name that appears after the AS keyword in the [ATTACH] statement. 7397 ** For the main database file, the database name is "main". For TEMP 7398 ** tables, the database name is "temp".)^ 7399 ** 7400 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 7401 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 7402 ** read-only access. 7403 ** 7404 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 7405 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 7406 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 7407 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 7408 ** on *ppBlob after this function it returns. 7409 ** 7410 ** This function fails with SQLITE_ERROR if any of the following are true: 7411 ** <ul> 7412 ** <li> ^(Database zDb does not exist)^, 7413 ** <li> ^(Table zTable does not exist within database zDb)^, 7414 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 7415 ** <li> ^(Column zColumn does not exist)^, 7416 ** <li> ^(Row iRow is not present in the table)^, 7417 ** <li> ^(The specified column of row iRow contains a value that is not 7418 ** a TEXT or BLOB value)^, 7419 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 7420 ** constraint and the blob is being opened for read/write access)^, 7421 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 7422 ** column zColumn is part of a [child key] definition and the blob is 7423 ** being opened for read/write access)^. 7424 ** </ul> 7425 ** 7426 ** ^Unless it returns SQLITE_MISUSE, this function sets the 7427 ** [database connection] error code and message accessible via 7428 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7429 ** 7430 ** A BLOB referenced by sqlite3_blob_open() may be read using the 7431 ** [sqlite3_blob_read()] interface and modified by using 7432 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 7433 ** different row of the same table using the [sqlite3_blob_reopen()] 7434 ** interface. However, the column, table, or database of a [BLOB handle] 7435 ** cannot be changed after the [BLOB handle] is opened. 7436 ** 7437 ** ^(If the row that a BLOB handle points to is modified by an 7438 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 7439 ** then the BLOB handle is marked as "expired". 7440 ** This is true if any column of the row is changed, even a column 7441 ** other than the one the BLOB handle is open on.)^ 7442 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 7443 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 7444 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 7445 ** rolled back by the expiration of the BLOB. Such changes will eventually 7446 ** commit if the transaction continues to completion.)^ 7447 ** 7448 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 7449 ** the opened blob. ^The size of a blob may not be changed by this 7450 ** interface. Use the [UPDATE] SQL command to change the size of a 7451 ** blob. 7452 ** 7453 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 7454 ** and the built-in [zeroblob] SQL function may be used to create a 7455 ** zero-filled blob to read or write using the incremental-blob interface. 7456 ** 7457 ** To avoid a resource leak, every open [BLOB handle] should eventually 7458 ** be released by a call to [sqlite3_blob_close()]. 7459 ** 7460 ** See also: [sqlite3_blob_close()], 7461 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 7462 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 7463 */ 7464 SQLITE_API int sqlite3_blob_open( 7465 sqlite3*, 7466 const char *zDb, 7467 const char *zTable, 7468 const char *zColumn, 7469 sqlite3_int64 iRow, 7470 int flags, 7471 sqlite3_blob **ppBlob 7472 ); 7473 7474 /* 7475 ** CAPI3REF: Move a BLOB Handle to a New Row 7476 ** METHOD: sqlite3_blob 7477 ** 7478 ** ^This function is used to move an existing [BLOB handle] so that it points 7479 ** to a different row of the same database table. ^The new row is identified 7480 ** by the rowid value passed as the second argument. Only the row can be 7481 ** changed. ^The database, table and column on which the blob handle is open 7482 ** remain the same. Moving an existing [BLOB handle] to a new row is 7483 ** faster than closing the existing handle and opening a new one. 7484 ** 7485 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 7486 ** it must exist and there must be either a blob or text value stored in 7487 ** the nominated column.)^ ^If the new row is not present in the table, or if 7488 ** it does not contain a blob or text value, or if another error occurs, an 7489 ** SQLite error code is returned and the blob handle is considered aborted. 7490 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 7491 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 7492 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 7493 ** always returns zero. 7494 ** 7495 ** ^This function sets the database handle error code and message. 7496 */ 7497 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 7498 7499 /* 7500 ** CAPI3REF: Close A BLOB Handle 7501 ** DESTRUCTOR: sqlite3_blob 7502 ** 7503 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 7504 ** unconditionally. Even if this routine returns an error code, the 7505 ** handle is still closed.)^ 7506 ** 7507 ** ^If the blob handle being closed was opened for read-write access, and if 7508 ** the database is in auto-commit mode and there are no other open read-write 7509 ** blob handles or active write statements, the current transaction is 7510 ** committed. ^If an error occurs while committing the transaction, an error 7511 ** code is returned and the transaction rolled back. 7512 ** 7513 ** Calling this function with an argument that is not a NULL pointer or an 7514 ** open blob handle results in undefined behaviour. ^Calling this routine 7515 ** with a null pointer (such as would be returned by a failed call to 7516 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 7517 ** is passed a valid open blob handle, the values returned by the 7518 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 7519 */ 7520 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 7521 7522 /* 7523 ** CAPI3REF: Return The Size Of An Open BLOB 7524 ** METHOD: sqlite3_blob 7525 ** 7526 ** ^Returns the size in bytes of the BLOB accessible via the 7527 ** successfully opened [BLOB handle] in its only argument. ^The 7528 ** incremental blob I/O routines can only read or overwriting existing 7529 ** blob content; they cannot change the size of a blob. 7530 ** 7531 ** This routine only works on a [BLOB handle] which has been created 7532 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7533 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7534 ** to this routine results in undefined and probably undesirable behavior. 7535 */ 7536 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 7537 7538 /* 7539 ** CAPI3REF: Read Data From A BLOB Incrementally 7540 ** METHOD: sqlite3_blob 7541 ** 7542 ** ^(This function is used to read data from an open [BLOB handle] into a 7543 ** caller-supplied buffer. N bytes of data are copied into buffer Z 7544 ** from the open BLOB, starting at offset iOffset.)^ 7545 ** 7546 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7547 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 7548 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 7549 ** ^The size of the blob (and hence the maximum value of N+iOffset) 7550 ** can be determined using the [sqlite3_blob_bytes()] interface. 7551 ** 7552 ** ^An attempt to read from an expired [BLOB handle] fails with an 7553 ** error code of [SQLITE_ABORT]. 7554 ** 7555 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 7556 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7557 ** 7558 ** This routine only works on a [BLOB handle] which has been created 7559 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7560 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7561 ** to this routine results in undefined and probably undesirable behavior. 7562 ** 7563 ** See also: [sqlite3_blob_write()]. 7564 */ 7565 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 7566 7567 /* 7568 ** CAPI3REF: Write Data Into A BLOB Incrementally 7569 ** METHOD: sqlite3_blob 7570 ** 7571 ** ^(This function is used to write data into an open [BLOB handle] from a 7572 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 7573 ** into the open BLOB, starting at offset iOffset.)^ 7574 ** 7575 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 7576 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7577 ** ^Unless SQLITE_MISUSE is returned, this function sets the 7578 ** [database connection] error code and message accessible via 7579 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7580 ** 7581 ** ^If the [BLOB handle] passed as the first argument was not opened for 7582 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 7583 ** this function returns [SQLITE_READONLY]. 7584 ** 7585 ** This function may only modify the contents of the BLOB; it is 7586 ** not possible to increase the size of a BLOB using this API. 7587 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7588 ** [SQLITE_ERROR] is returned and no data is written. The size of the 7589 ** BLOB (and hence the maximum value of N+iOffset) can be determined 7590 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 7591 ** than zero [SQLITE_ERROR] is returned and no data is written. 7592 ** 7593 ** ^An attempt to write to an expired [BLOB handle] fails with an 7594 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 7595 ** before the [BLOB handle] expired are not rolled back by the 7596 ** expiration of the handle, though of course those changes might 7597 ** have been overwritten by the statement that expired the BLOB handle 7598 ** or by other independent statements. 7599 ** 7600 ** This routine only works on a [BLOB handle] which has been created 7601 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7602 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7603 ** to this routine results in undefined and probably undesirable behavior. 7604 ** 7605 ** See also: [sqlite3_blob_read()]. 7606 */ 7607 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7608 7609 /* 7610 ** CAPI3REF: Virtual File System Objects 7611 ** 7612 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7613 ** that SQLite uses to interact 7614 ** with the underlying operating system. Most SQLite builds come with a 7615 ** single default VFS that is appropriate for the host computer. 7616 ** New VFSes can be registered and existing VFSes can be unregistered. 7617 ** The following interfaces are provided. 7618 ** 7619 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7620 ** ^Names are case sensitive. 7621 ** ^Names are zero-terminated UTF-8 strings. 7622 ** ^If there is no match, a NULL pointer is returned. 7623 ** ^If zVfsName is NULL then the default VFS is returned. 7624 ** 7625 ** ^New VFSes are registered with sqlite3_vfs_register(). 7626 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7627 ** ^The same VFS can be registered multiple times without injury. 7628 ** ^To make an existing VFS into the default VFS, register it again 7629 ** with the makeDflt flag set. If two different VFSes with the 7630 ** same name are registered, the behavior is undefined. If a 7631 ** VFS is registered with a name that is NULL or an empty string, 7632 ** then the behavior is undefined. 7633 ** 7634 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7635 ** ^(If the default VFS is unregistered, another VFS is chosen as 7636 ** the default. The choice for the new VFS is arbitrary.)^ 7637 */ 7638 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 7639 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 7640 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 7641 7642 /* 7643 ** CAPI3REF: Mutexes 7644 ** 7645 ** The SQLite core uses these routines for thread 7646 ** synchronization. Though they are intended for internal 7647 ** use by SQLite, code that links against SQLite is 7648 ** permitted to use any of these routines. 7649 ** 7650 ** The SQLite source code contains multiple implementations 7651 ** of these mutex routines. An appropriate implementation 7652 ** is selected automatically at compile-time. The following 7653 ** implementations are available in the SQLite core: 7654 ** 7655 ** <ul> 7656 ** <li> SQLITE_MUTEX_PTHREADS 7657 ** <li> SQLITE_MUTEX_W32 7658 ** <li> SQLITE_MUTEX_NOOP 7659 ** </ul> 7660 ** 7661 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 7662 ** that does no real locking and is appropriate for use in 7663 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7664 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7665 ** and Windows. 7666 ** 7667 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 7668 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 7669 ** implementation is included with the library. In this case the 7670 ** application must supply a custom mutex implementation using the 7671 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 7672 ** before calling sqlite3_initialize() or any other public sqlite3_ 7673 ** function that calls sqlite3_initialize(). 7674 ** 7675 ** ^The sqlite3_mutex_alloc() routine allocates a new 7676 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 7677 ** routine returns NULL if it is unable to allocate the requested 7678 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 7679 ** integer constants: 7680 ** 7681 ** <ul> 7682 ** <li> SQLITE_MUTEX_FAST 7683 ** <li> SQLITE_MUTEX_RECURSIVE 7684 ** <li> SQLITE_MUTEX_STATIC_MAIN 7685 ** <li> SQLITE_MUTEX_STATIC_MEM 7686 ** <li> SQLITE_MUTEX_STATIC_OPEN 7687 ** <li> SQLITE_MUTEX_STATIC_PRNG 7688 ** <li> SQLITE_MUTEX_STATIC_LRU 7689 ** <li> SQLITE_MUTEX_STATIC_PMEM 7690 ** <li> SQLITE_MUTEX_STATIC_APP1 7691 ** <li> SQLITE_MUTEX_STATIC_APP2 7692 ** <li> SQLITE_MUTEX_STATIC_APP3 7693 ** <li> SQLITE_MUTEX_STATIC_VFS1 7694 ** <li> SQLITE_MUTEX_STATIC_VFS2 7695 ** <li> SQLITE_MUTEX_STATIC_VFS3 7696 ** </ul> 7697 ** 7698 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 7699 ** cause sqlite3_mutex_alloc() to create 7700 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 7701 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 7702 ** The mutex implementation does not need to make a distinction 7703 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 7704 ** not want to. SQLite will only request a recursive mutex in 7705 ** cases where it really needs one. If a faster non-recursive mutex 7706 ** implementation is available on the host platform, the mutex subsystem 7707 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 7708 ** 7709 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 7710 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 7711 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 7712 ** used by the current version of SQLite. Future versions of SQLite 7713 ** may add additional static mutexes. Static mutexes are for internal 7714 ** use by SQLite only. Applications that use SQLite mutexes should 7715 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 7716 ** SQLITE_MUTEX_RECURSIVE. 7717 ** 7718 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 7719 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 7720 ** returns a different mutex on every call. ^For the static 7721 ** mutex types, the same mutex is returned on every call that has 7722 ** the same type number. 7723 ** 7724 ** ^The sqlite3_mutex_free() routine deallocates a previously 7725 ** allocated dynamic mutex. Attempting to deallocate a static 7726 ** mutex results in undefined behavior. 7727 ** 7728 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 7729 ** to enter a mutex. ^If another thread is already within the mutex, 7730 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 7731 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 7732 ** upon successful entry. ^(Mutexes created using 7733 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 7734 ** In such cases, the 7735 ** mutex must be exited an equal number of times before another thread 7736 ** can enter.)^ If the same thread tries to enter any mutex other 7737 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 7738 ** 7739 ** ^(Some systems (for example, Windows 95) do not support the operation 7740 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 7741 ** will always return SQLITE_BUSY. The SQLite core only ever uses 7742 ** sqlite3_mutex_try() as an optimization so this is acceptable 7743 ** behavior.)^ 7744 ** 7745 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 7746 ** previously entered by the same thread. The behavior 7747 ** is undefined if the mutex is not currently entered by the 7748 ** calling thread or is not currently allocated. 7749 ** 7750 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 7751 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 7752 ** behave as no-ops. 7753 ** 7754 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7755 */ 7756 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 7757 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 7758 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 7759 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 7760 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 7761 7762 /* 7763 ** CAPI3REF: Mutex Methods Object 7764 ** 7765 ** An instance of this structure defines the low-level routines 7766 ** used to allocate and use mutexes. 7767 ** 7768 ** Usually, the default mutex implementations provided by SQLite are 7769 ** sufficient, however the application has the option of substituting a custom 7770 ** implementation for specialized deployments or systems for which SQLite 7771 ** does not provide a suitable implementation. In this case, the application 7772 ** creates and populates an instance of this structure to pass 7773 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7774 ** Additionally, an instance of this structure can be used as an 7775 ** output variable when querying the system for the current mutex 7776 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7777 ** 7778 ** ^The xMutexInit method defined by this structure is invoked as 7779 ** part of system initialization by the sqlite3_initialize() function. 7780 ** ^The xMutexInit routine is called by SQLite exactly once for each 7781 ** effective call to [sqlite3_initialize()]. 7782 ** 7783 ** ^The xMutexEnd method defined by this structure is invoked as 7784 ** part of system shutdown by the sqlite3_shutdown() function. The 7785 ** implementation of this method is expected to release all outstanding 7786 ** resources obtained by the mutex methods implementation, especially 7787 ** those obtained by the xMutexInit method. ^The xMutexEnd() 7788 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7789 ** 7790 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7791 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7792 ** xMutexNotheld) implement the following interfaces (respectively): 7793 ** 7794 ** <ul> 7795 ** <li> [sqlite3_mutex_alloc()] </li> 7796 ** <li> [sqlite3_mutex_free()] </li> 7797 ** <li> [sqlite3_mutex_enter()] </li> 7798 ** <li> [sqlite3_mutex_try()] </li> 7799 ** <li> [sqlite3_mutex_leave()] </li> 7800 ** <li> [sqlite3_mutex_held()] </li> 7801 ** <li> [sqlite3_mutex_notheld()] </li> 7802 ** </ul>)^ 7803 ** 7804 ** The only difference is that the public sqlite3_XXX functions enumerated 7805 ** above silently ignore any invocations that pass a NULL pointer instead 7806 ** of a valid mutex handle. The implementations of the methods defined 7807 ** by this structure are not required to handle this case. The results 7808 ** of passing a NULL pointer instead of a valid mutex handle are undefined 7809 ** (i.e. it is acceptable to provide an implementation that segfaults if 7810 ** it is passed a NULL pointer). 7811 ** 7812 ** The xMutexInit() method must be threadsafe. It must be harmless to 7813 ** invoke xMutexInit() multiple times within the same process and without 7814 ** intervening calls to xMutexEnd(). Second and subsequent calls to 7815 ** xMutexInit() must be no-ops. 7816 ** 7817 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7818 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7819 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7820 ** memory allocation for a fast or recursive mutex. 7821 ** 7822 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7823 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7824 ** If xMutexInit fails in any way, it is expected to clean up after itself 7825 ** prior to returning. 7826 */ 7827 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7828 struct sqlite3_mutex_methods { 7829 int (*xMutexInit)(void); 7830 int (*xMutexEnd)(void); 7831 sqlite3_mutex *(*xMutexAlloc)(int); 7832 void (*xMutexFree)(sqlite3_mutex *); 7833 void (*xMutexEnter)(sqlite3_mutex *); 7834 int (*xMutexTry)(sqlite3_mutex *); 7835 void (*xMutexLeave)(sqlite3_mutex *); 7836 int (*xMutexHeld)(sqlite3_mutex *); 7837 int (*xMutexNotheld)(sqlite3_mutex *); 7838 }; 7839 7840 /* 7841 ** CAPI3REF: Mutex Verification Routines 7842 ** 7843 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7844 ** are intended for use inside assert() statements. The SQLite core 7845 ** never uses these routines except inside an assert() and applications 7846 ** are advised to follow the lead of the core. The SQLite core only 7847 ** provides implementations for these routines when it is compiled 7848 ** with the SQLITE_DEBUG flag. External mutex implementations 7849 ** are only required to provide these routines if SQLITE_DEBUG is 7850 ** defined and if NDEBUG is not defined. 7851 ** 7852 ** These routines should return true if the mutex in their argument 7853 ** is held or not held, respectively, by the calling thread. 7854 ** 7855 ** The implementation is not required to provide versions of these 7856 ** routines that actually work. If the implementation does not provide working 7857 ** versions of these routines, it should at least provide stubs that always 7858 ** return true so that one does not get spurious assertion failures. 7859 ** 7860 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 7861 ** the routine should return 1. This seems counter-intuitive since 7862 ** clearly the mutex cannot be held if it does not exist. But 7863 ** the reason the mutex does not exist is because the build is not 7864 ** using mutexes. And we do not want the assert() containing the 7865 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 7866 ** the appropriate thing to do. The sqlite3_mutex_notheld() 7867 ** interface should also return 1 when given a NULL pointer. 7868 */ 7869 #ifndef NDEBUG 7870 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 7871 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 7872 #endif 7873 7874 /* 7875 ** CAPI3REF: Mutex Types 7876 ** 7877 ** The [sqlite3_mutex_alloc()] interface takes a single argument 7878 ** which is one of these integer constants. 7879 ** 7880 ** The set of static mutexes may change from one SQLite release to the 7881 ** next. Applications that override the built-in mutex logic must be 7882 ** prepared to accommodate additional static mutexes. 7883 */ 7884 #define SQLITE_MUTEX_FAST 0 7885 #define SQLITE_MUTEX_RECURSIVE 1 7886 #define SQLITE_MUTEX_STATIC_MAIN 2 7887 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7888 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7889 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7890 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7891 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7892 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7893 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7894 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7895 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7896 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7897 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7898 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7899 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7900 7901 /* Legacy compatibility: */ 7902 #define SQLITE_MUTEX_STATIC_MASTER 2 7903 7904 7905 /* 7906 ** CAPI3REF: Retrieve the mutex for a database connection 7907 ** METHOD: sqlite3 7908 ** 7909 ** ^This interface returns a pointer the [sqlite3_mutex] object that 7910 ** serializes access to the [database connection] given in the argument 7911 ** when the [threading mode] is Serialized. 7912 ** ^If the [threading mode] is Single-thread or Multi-thread then this 7913 ** routine returns a NULL pointer. 7914 */ 7915 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7916 7917 /* 7918 ** CAPI3REF: Low-Level Control Of Database Files 7919 ** METHOD: sqlite3 7920 ** KEYWORDS: {file control} 7921 ** 7922 ** ^The [sqlite3_file_control()] interface makes a direct call to the 7923 ** xFileControl method for the [sqlite3_io_methods] object associated 7924 ** with a particular database identified by the second argument. ^The 7925 ** name of the database is "main" for the main database or "temp" for the 7926 ** TEMP database, or the name that appears after the AS keyword for 7927 ** databases that are added using the [ATTACH] SQL command. 7928 ** ^A NULL pointer can be used in place of "main" to refer to the 7929 ** main database file. 7930 ** ^The third and fourth parameters to this routine 7931 ** are passed directly through to the second and third parameters of 7932 ** the xFileControl method. ^The return value of the xFileControl 7933 ** method becomes the return value of this routine. 7934 ** 7935 ** A few opcodes for [sqlite3_file_control()] are handled directly 7936 ** by the SQLite core and never invoke the 7937 ** sqlite3_io_methods.xFileControl method. 7938 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7939 ** a pointer to the underlying [sqlite3_file] object to be written into 7940 ** the space pointed to by the 4th parameter. The 7941 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 7942 ** the [sqlite3_file] object associated with the journal file instead of 7943 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 7944 ** a pointer to the underlying [sqlite3_vfs] object for the file. 7945 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 7946 ** from the pager. 7947 ** 7948 ** ^If the second parameter (zDbName) does not match the name of any 7949 ** open database file, then SQLITE_ERROR is returned. ^This error 7950 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 7951 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 7952 ** also return SQLITE_ERROR. There is no way to distinguish between 7953 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7954 ** xFileControl method. 7955 ** 7956 ** See also: [file control opcodes] 7957 */ 7958 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7959 7960 /* 7961 ** CAPI3REF: Testing Interface 7962 ** 7963 ** ^The sqlite3_test_control() interface is used to read out internal 7964 ** state of SQLite and to inject faults into SQLite for testing 7965 ** purposes. ^The first parameter is an operation code that determines 7966 ** the number, meaning, and operation of all subsequent parameters. 7967 ** 7968 ** This interface is not for use by applications. It exists solely 7969 ** for verifying the correct operation of the SQLite library. Depending 7970 ** on how the SQLite library is compiled, this interface might not exist. 7971 ** 7972 ** The details of the operation codes, their meanings, the parameters 7973 ** they take, and what they do are all subject to change without notice. 7974 ** Unlike most of the SQLite API, this function is not guaranteed to 7975 ** operate consistently from one release to the next. 7976 */ 7977 SQLITE_API int sqlite3_test_control(int op, ...); 7978 7979 /* 7980 ** CAPI3REF: Testing Interface Operation Codes 7981 ** 7982 ** These constants are the valid operation code parameters used 7983 ** as the first argument to [sqlite3_test_control()]. 7984 ** 7985 ** These parameters and their meanings are subject to change 7986 ** without notice. These values are for testing purposes only. 7987 ** Applications should not use any of these parameters or the 7988 ** [sqlite3_test_control()] interface. 7989 */ 7990 #define SQLITE_TESTCTRL_FIRST 5 7991 #define SQLITE_TESTCTRL_PRNG_SAVE 5 7992 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 7993 #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 7994 #define SQLITE_TESTCTRL_BITVEC_TEST 8 7995 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 7996 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7997 #define SQLITE_TESTCTRL_PENDING_BYTE 11 7998 #define SQLITE_TESTCTRL_ASSERT 12 7999 #define SQLITE_TESTCTRL_ALWAYS 13 8000 #define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */ 8001 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 8002 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 8003 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 8004 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 8005 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 8006 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 8007 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 8008 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 8009 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 8010 #define SQLITE_TESTCTRL_BYTEORDER 22 8011 #define SQLITE_TESTCTRL_ISINIT 23 8012 #define SQLITE_TESTCTRL_SORTER_MMAP 24 8013 #define SQLITE_TESTCTRL_IMPOSTER 25 8014 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26 8015 #define SQLITE_TESTCTRL_RESULT_INTREAL 27 8016 #define SQLITE_TESTCTRL_PRNG_SEED 28 8017 #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 8018 #define SQLITE_TESTCTRL_SEEK_COUNT 30 8019 #define SQLITE_TESTCTRL_TRACEFLAGS 31 8020 #define SQLITE_TESTCTRL_TUNE 32 8021 #define SQLITE_TESTCTRL_LOGEST 33 8022 #define SQLITE_TESTCTRL_LAST 33 /* Largest TESTCTRL */ 8023 8024 /* 8025 ** CAPI3REF: SQL Keyword Checking 8026 ** 8027 ** These routines provide access to the set of SQL language keywords 8028 ** recognized by SQLite. Applications can uses these routines to determine 8029 ** whether or not a specific identifier needs to be escaped (for example, 8030 ** by enclosing in double-quotes) so as not to confuse the parser. 8031 ** 8032 ** The sqlite3_keyword_count() interface returns the number of distinct 8033 ** keywords understood by SQLite. 8034 ** 8035 ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 8036 ** makes *Z point to that keyword expressed as UTF8 and writes the number 8037 ** of bytes in the keyword into *L. The string that *Z points to is not 8038 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 8039 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 8040 ** or L are NULL or invalid pointers then calls to 8041 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 8042 ** 8043 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 8044 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 8045 ** if it is and zero if not. 8046 ** 8047 ** The parser used by SQLite is forgiving. It is often possible to use 8048 ** a keyword as an identifier as long as such use does not result in a 8049 ** parsing ambiguity. For example, the statement 8050 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 8051 ** creates a new table named "BEGIN" with three columns named 8052 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 8053 ** using keywords as identifiers. Common techniques used to avoid keyword 8054 ** name collisions include: 8055 ** <ul> 8056 ** <li> Put all identifier names inside double-quotes. This is the official 8057 ** SQL way to escape identifier names. 8058 ** <li> Put identifier names inside [...]. This is not standard SQL, 8059 ** but it is what SQL Server does and so lots of programmers use this 8060 ** technique. 8061 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start 8062 ** with "Z". 8063 ** <li> Include a digit somewhere in every identifier name. 8064 ** </ul> 8065 ** 8066 ** Note that the number of keywords understood by SQLite can depend on 8067 ** compile-time options. For example, "VACUUM" is not a keyword if 8068 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 8069 ** new keywords may be added to future releases of SQLite. 8070 */ 8071 SQLITE_API int sqlite3_keyword_count(void); 8072 SQLITE_API int sqlite3_keyword_name(int,const char**,int*); 8073 SQLITE_API int sqlite3_keyword_check(const char*,int); 8074 8075 /* 8076 ** CAPI3REF: Dynamic String Object 8077 ** KEYWORDS: {dynamic string} 8078 ** 8079 ** An instance of the sqlite3_str object contains a dynamically-sized 8080 ** string under construction. 8081 ** 8082 ** The lifecycle of an sqlite3_str object is as follows: 8083 ** <ol> 8084 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 8085 ** <li> ^Text is appended to the sqlite3_str object using various 8086 ** methods, such as [sqlite3_str_appendf()]. 8087 ** <li> ^The sqlite3_str object is destroyed and the string it created 8088 ** is returned using the [sqlite3_str_finish()] interface. 8089 ** </ol> 8090 */ 8091 typedef struct sqlite3_str sqlite3_str; 8092 8093 /* 8094 ** CAPI3REF: Create A New Dynamic String Object 8095 ** CONSTRUCTOR: sqlite3_str 8096 ** 8097 ** ^The [sqlite3_str_new(D)] interface allocates and initializes 8098 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 8099 ** [sqlite3_str_new()] must be freed by a subsequent call to 8100 ** [sqlite3_str_finish(X)]. 8101 ** 8102 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 8103 ** valid [sqlite3_str] object, though in the event of an out-of-memory 8104 ** error the returned object might be a special singleton that will 8105 ** silently reject new text, always return SQLITE_NOMEM from 8106 ** [sqlite3_str_errcode()], always return 0 for 8107 ** [sqlite3_str_length()], and always return NULL from 8108 ** [sqlite3_str_finish(X)]. It is always safe to use the value 8109 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 8110 ** to any of the other [sqlite3_str] methods. 8111 ** 8112 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 8113 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 8114 ** length of the string contained in the [sqlite3_str] object will be 8115 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 8116 ** of [SQLITE_MAX_LENGTH]. 8117 */ 8118 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*); 8119 8120 /* 8121 ** CAPI3REF: Finalize A Dynamic String 8122 ** DESTRUCTOR: sqlite3_str 8123 ** 8124 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 8125 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 8126 ** that contains the constructed string. The calling application should 8127 ** pass the returned value to [sqlite3_free()] to avoid a memory leak. 8128 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 8129 ** errors were encountered during construction of the string. ^The 8130 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 8131 ** string in [sqlite3_str] object X is zero bytes long. 8132 */ 8133 SQLITE_API char *sqlite3_str_finish(sqlite3_str*); 8134 8135 /* 8136 ** CAPI3REF: Add Content To A Dynamic String 8137 ** METHOD: sqlite3_str 8138 ** 8139 ** These interfaces add content to an sqlite3_str object previously obtained 8140 ** from [sqlite3_str_new()]. 8141 ** 8142 ** ^The [sqlite3_str_appendf(X,F,...)] and 8143 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 8144 ** functionality of SQLite to append formatted text onto the end of 8145 ** [sqlite3_str] object X. 8146 ** 8147 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 8148 ** onto the end of the [sqlite3_str] object X. N must be non-negative. 8149 ** S must contain at least N non-zero bytes of content. To append a 8150 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 8151 ** method instead. 8152 ** 8153 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 8154 ** zero-terminated string S onto the end of [sqlite3_str] object X. 8155 ** 8156 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 8157 ** single-byte character C onto the end of [sqlite3_str] object X. 8158 ** ^This method can be used, for example, to add whitespace indentation. 8159 ** 8160 ** ^The [sqlite3_str_reset(X)] method resets the string under construction 8161 ** inside [sqlite3_str] object X back to zero bytes in length. 8162 ** 8163 ** These methods do not return a result code. ^If an error occurs, that fact 8164 ** is recorded in the [sqlite3_str] object and can be recovered by a 8165 ** subsequent call to [sqlite3_str_errcode(X)]. 8166 */ 8167 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 8168 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 8169 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 8170 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 8171 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 8172 SQLITE_API void sqlite3_str_reset(sqlite3_str*); 8173 8174 /* 8175 ** CAPI3REF: Status Of A Dynamic String 8176 ** METHOD: sqlite3_str 8177 ** 8178 ** These interfaces return the current status of an [sqlite3_str] object. 8179 ** 8180 ** ^If any prior errors have occurred while constructing the dynamic string 8181 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 8182 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 8183 ** [SQLITE_NOMEM] following any out-of-memory error, or 8184 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 8185 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 8186 ** 8187 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 8188 ** of the dynamic string under construction in [sqlite3_str] object X. 8189 ** ^The length returned by [sqlite3_str_length(X)] does not include the 8190 ** zero-termination byte. 8191 ** 8192 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current 8193 ** content of the dynamic string under construction in X. The value 8194 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 8195 ** and might be freed or altered by any subsequent method on the same 8196 ** [sqlite3_str] object. Applications must not used the pointer returned 8197 ** [sqlite3_str_value(X)] after any subsequent method call on the same 8198 ** object. ^Applications may change the content of the string returned 8199 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes 8200 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 8201 ** write any byte after any subsequent sqlite3_str method call. 8202 */ 8203 SQLITE_API int sqlite3_str_errcode(sqlite3_str*); 8204 SQLITE_API int sqlite3_str_length(sqlite3_str*); 8205 SQLITE_API char *sqlite3_str_value(sqlite3_str*); 8206 8207 /* 8208 ** CAPI3REF: SQLite Runtime Status 8209 ** 8210 ** ^These interfaces are used to retrieve runtime status information 8211 ** about the performance of SQLite, and optionally to reset various 8212 ** highwater marks. ^The first argument is an integer code for 8213 ** the specific parameter to measure. ^(Recognized integer codes 8214 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 8215 ** ^The current value of the parameter is returned into *pCurrent. 8216 ** ^The highest recorded value is returned in *pHighwater. ^If the 8217 ** resetFlag is true, then the highest record value is reset after 8218 ** *pHighwater is written. ^(Some parameters do not record the highest 8219 ** value. For those parameters 8220 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 8221 ** ^(Other parameters record only the highwater mark and not the current 8222 ** value. For these latter parameters nothing is written into *pCurrent.)^ 8223 ** 8224 ** ^The sqlite3_status() and sqlite3_status64() routines return 8225 ** SQLITE_OK on success and a non-zero [error code] on failure. 8226 ** 8227 ** If either the current value or the highwater mark is too large to 8228 ** be represented by a 32-bit integer, then the values returned by 8229 ** sqlite3_status() are undefined. 8230 ** 8231 ** See also: [sqlite3_db_status()] 8232 */ 8233 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 8234 SQLITE_API int sqlite3_status64( 8235 int op, 8236 sqlite3_int64 *pCurrent, 8237 sqlite3_int64 *pHighwater, 8238 int resetFlag 8239 ); 8240 8241 8242 /* 8243 ** CAPI3REF: Status Parameters 8244 ** KEYWORDS: {status parameters} 8245 ** 8246 ** These integer constants designate various run-time status parameters 8247 ** that can be returned by [sqlite3_status()]. 8248 ** 8249 ** <dl> 8250 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 8251 ** <dd>This parameter is the current amount of memory checked out 8252 ** using [sqlite3_malloc()], either directly or indirectly. The 8253 ** figure includes calls made to [sqlite3_malloc()] by the application 8254 ** and internal memory usage by the SQLite library. Auxiliary page-cache 8255 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 8256 ** this parameter. The amount returned is the sum of the allocation 8257 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 8258 ** 8259 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 8260 ** <dd>This parameter records the largest memory allocation request 8261 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 8262 ** internal equivalents). Only the value returned in the 8263 ** *pHighwater parameter to [sqlite3_status()] is of interest. 8264 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8265 ** 8266 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 8267 ** <dd>This parameter records the number of separate memory allocations 8268 ** currently checked out.</dd>)^ 8269 ** 8270 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 8271 ** <dd>This parameter returns the number of pages used out of the 8272 ** [pagecache memory allocator] that was configured using 8273 ** [SQLITE_CONFIG_PAGECACHE]. The 8274 ** value returned is in pages, not in bytes.</dd>)^ 8275 ** 8276 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 8277 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 8278 ** <dd>This parameter returns the number of bytes of page cache 8279 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 8280 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 8281 ** returned value includes allocations that overflowed because they 8282 ** where too large (they were larger than the "sz" parameter to 8283 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 8284 ** no space was left in the page cache.</dd>)^ 8285 ** 8286 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 8287 ** <dd>This parameter records the largest memory allocation request 8288 ** handed to the [pagecache memory allocator]. Only the value returned in the 8289 ** *pHighwater parameter to [sqlite3_status()] is of interest. 8290 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8291 ** 8292 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 8293 ** <dd>No longer used.</dd> 8294 ** 8295 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 8296 ** <dd>No longer used.</dd> 8297 ** 8298 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 8299 ** <dd>No longer used.</dd> 8300 ** 8301 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 8302 ** <dd>The *pHighwater parameter records the deepest parser stack. 8303 ** The *pCurrent value is undefined. The *pHighwater value is only 8304 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 8305 ** </dl> 8306 ** 8307 ** New status parameters may be added from time to time. 8308 */ 8309 #define SQLITE_STATUS_MEMORY_USED 0 8310 #define SQLITE_STATUS_PAGECACHE_USED 1 8311 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 8312 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 8313 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 8314 #define SQLITE_STATUS_MALLOC_SIZE 5 8315 #define SQLITE_STATUS_PARSER_STACK 6 8316 #define SQLITE_STATUS_PAGECACHE_SIZE 7 8317 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 8318 #define SQLITE_STATUS_MALLOC_COUNT 9 8319 8320 /* 8321 ** CAPI3REF: Database Connection Status 8322 ** METHOD: sqlite3 8323 ** 8324 ** ^This interface is used to retrieve runtime status information 8325 ** about a single [database connection]. ^The first argument is the 8326 ** database connection object to be interrogated. ^The second argument 8327 ** is an integer constant, taken from the set of 8328 ** [SQLITE_DBSTATUS options], that 8329 ** determines the parameter to interrogate. The set of 8330 ** [SQLITE_DBSTATUS options] is likely 8331 ** to grow in future releases of SQLite. 8332 ** 8333 ** ^The current value of the requested parameter is written into *pCur 8334 ** and the highest instantaneous value is written into *pHiwtr. ^If 8335 ** the resetFlg is true, then the highest instantaneous value is 8336 ** reset back down to the current value. 8337 ** 8338 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 8339 ** non-zero [error code] on failure. 8340 ** 8341 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 8342 */ 8343 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 8344 8345 /* 8346 ** CAPI3REF: Status Parameters for database connections 8347 ** KEYWORDS: {SQLITE_DBSTATUS options} 8348 ** 8349 ** These constants are the available integer "verbs" that can be passed as 8350 ** the second argument to the [sqlite3_db_status()] interface. 8351 ** 8352 ** New verbs may be added in future releases of SQLite. Existing verbs 8353 ** might be discontinued. Applications should check the return code from 8354 ** [sqlite3_db_status()] to make sure that the call worked. 8355 ** The [sqlite3_db_status()] interface will return a non-zero error code 8356 ** if a discontinued or unsupported verb is invoked. 8357 ** 8358 ** <dl> 8359 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 8360 ** <dd>This parameter returns the number of lookaside memory slots currently 8361 ** checked out.</dd>)^ 8362 ** 8363 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 8364 ** <dd>This parameter returns the number of malloc attempts that were 8365 ** satisfied using lookaside memory. Only the high-water value is meaningful; 8366 ** the current value is always zero.)^ 8367 ** 8368 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 8369 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 8370 ** <dd>This parameter returns the number malloc attempts that might have 8371 ** been satisfied using lookaside memory but failed due to the amount of 8372 ** memory requested being larger than the lookaside slot size. 8373 ** Only the high-water value is meaningful; 8374 ** the current value is always zero.)^ 8375 ** 8376 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 8377 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 8378 ** <dd>This parameter returns the number malloc attempts that might have 8379 ** been satisfied using lookaside memory but failed due to all lookaside 8380 ** memory already being in use. 8381 ** Only the high-water value is meaningful; 8382 ** the current value is always zero.)^ 8383 ** 8384 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 8385 ** <dd>This parameter returns the approximate number of bytes of heap 8386 ** memory used by all pager caches associated with the database connection.)^ 8387 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 8388 ** 8389 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 8390 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 8391 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 8392 ** pager cache is shared between two or more connections the bytes of heap 8393 ** memory used by that pager cache is divided evenly between the attached 8394 ** connections.)^ In other words, if none of the pager caches associated 8395 ** with the database connection are shared, this request returns the same 8396 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 8397 ** shared, the value returned by this call will be smaller than that returned 8398 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 8399 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 8400 ** 8401 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 8402 ** <dd>This parameter returns the approximate number of bytes of heap 8403 ** memory used to store the schema for all databases associated 8404 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 8405 ** ^The full amount of memory used by the schemas is reported, even if the 8406 ** schema memory is shared with other database connections due to 8407 ** [shared cache mode] being enabled. 8408 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 8409 ** 8410 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 8411 ** <dd>This parameter returns the approximate number of bytes of heap 8412 ** and lookaside memory used by all prepared statements associated with 8413 ** the database connection.)^ 8414 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 8415 ** </dd> 8416 ** 8417 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 8418 ** <dd>This parameter returns the number of pager cache hits that have 8419 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 8420 ** is always 0. 8421 ** </dd> 8422 ** 8423 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 8424 ** <dd>This parameter returns the number of pager cache misses that have 8425 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 8426 ** is always 0. 8427 ** </dd> 8428 ** 8429 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 8430 ** <dd>This parameter returns the number of dirty cache entries that have 8431 ** been written to disk. Specifically, the number of pages written to the 8432 ** wal file in wal mode databases, or the number of pages written to the 8433 ** database file in rollback mode databases. Any pages written as part of 8434 ** transaction rollback or database recovery operations are not included. 8435 ** If an IO or other error occurs while writing a page to disk, the effect 8436 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 8437 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 8438 ** </dd> 8439 ** 8440 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 8441 ** <dd>This parameter returns the number of dirty cache entries that have 8442 ** been written to disk in the middle of a transaction due to the page 8443 ** cache overflowing. Transactions are more efficient if they are written 8444 ** to disk all at once. When pages spill mid-transaction, that introduces 8445 ** additional overhead. This parameter can be used help identify 8446 ** inefficiencies that can be resolved by increasing the cache size. 8447 ** </dd> 8448 ** 8449 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 8450 ** <dd>This parameter returns zero for the current value if and only if 8451 ** all foreign key constraints (deferred or immediate) have been 8452 ** resolved.)^ ^The highwater mark is always 0. 8453 ** </dd> 8454 ** </dl> 8455 */ 8456 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 8457 #define SQLITE_DBSTATUS_CACHE_USED 1 8458 #define SQLITE_DBSTATUS_SCHEMA_USED 2 8459 #define SQLITE_DBSTATUS_STMT_USED 3 8460 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 8461 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 8462 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 8463 #define SQLITE_DBSTATUS_CACHE_HIT 7 8464 #define SQLITE_DBSTATUS_CACHE_MISS 8 8465 #define SQLITE_DBSTATUS_CACHE_WRITE 9 8466 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 8467 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 8468 #define SQLITE_DBSTATUS_CACHE_SPILL 12 8469 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 8470 8471 8472 /* 8473 ** CAPI3REF: Prepared Statement Status 8474 ** METHOD: sqlite3_stmt 8475 ** 8476 ** ^(Each prepared statement maintains various 8477 ** [SQLITE_STMTSTATUS counters] that measure the number 8478 ** of times it has performed specific operations.)^ These counters can 8479 ** be used to monitor the performance characteristics of the prepared 8480 ** statements. For example, if the number of table steps greatly exceeds 8481 ** the number of table searches or result rows, that would tend to indicate 8482 ** that the prepared statement is using a full table scan rather than 8483 ** an index. 8484 ** 8485 ** ^(This interface is used to retrieve and reset counter values from 8486 ** a [prepared statement]. The first argument is the prepared statement 8487 ** object to be interrogated. The second argument 8488 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 8489 ** to be interrogated.)^ 8490 ** ^The current value of the requested counter is returned. 8491 ** ^If the resetFlg is true, then the counter is reset to zero after this 8492 ** interface call returns. 8493 ** 8494 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 8495 */ 8496 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 8497 8498 /* 8499 ** CAPI3REF: Status Parameters for prepared statements 8500 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 8501 ** 8502 ** These preprocessor macros define integer codes that name counter 8503 ** values associated with the [sqlite3_stmt_status()] interface. 8504 ** The meanings of the various counters are as follows: 8505 ** 8506 ** <dl> 8507 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 8508 ** <dd>^This is the number of times that SQLite has stepped forward in 8509 ** a table as part of a full table scan. Large numbers for this counter 8510 ** may indicate opportunities for performance improvement through 8511 ** careful use of indices.</dd> 8512 ** 8513 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 8514 ** <dd>^This is the number of sort operations that have occurred. 8515 ** A non-zero value in this counter may indicate an opportunity to 8516 ** improvement performance through careful use of indices.</dd> 8517 ** 8518 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 8519 ** <dd>^This is the number of rows inserted into transient indices that 8520 ** were created automatically in order to help joins run faster. 8521 ** A non-zero value in this counter may indicate an opportunity to 8522 ** improvement performance by adding permanent indices that do not 8523 ** need to be reinitialized each time the statement is run.</dd> 8524 ** 8525 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 8526 ** <dd>^This is the number of virtual machine operations executed 8527 ** by the prepared statement if that number is less than or equal 8528 ** to 2147483647. The number of virtual machine operations can be 8529 ** used as a proxy for the total work done by the prepared statement. 8530 ** If the number of virtual machine operations exceeds 2147483647 8531 ** then the value returned by this statement status code is undefined. 8532 ** 8533 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 8534 ** <dd>^This is the number of times that the prepare statement has been 8535 ** automatically regenerated due to schema changes or changes to 8536 ** [bound parameters] that might affect the query plan. 8537 ** 8538 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 8539 ** <dd>^This is the number of times that the prepared statement has 8540 ** been run. A single "run" for the purposes of this counter is one 8541 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 8542 ** The counter is incremented on the first [sqlite3_step()] call of each 8543 ** cycle. 8544 ** 8545 ** [[SQLITE_STMTSTATUS_FILTER_MISS]] 8546 ** [[SQLITE_STMTSTATUS_FILTER HIT]] 8547 ** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br> 8548 ** SQLITE_STMTSTATUS_FILTER_MISS</dt> 8549 ** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join 8550 ** step was bypassed because a Bloom filter returned not-found. The 8551 ** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of 8552 ** times that the Bloom filter returned a find, and thus the join step 8553 ** had to be processed as normal. 8554 ** 8555 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 8556 ** <dd>^This is the approximate number of bytes of heap memory 8557 ** used to store the prepared statement. ^This value is not actually 8558 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 8559 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 8560 ** </dd> 8561 ** </dl> 8562 */ 8563 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 8564 #define SQLITE_STMTSTATUS_SORT 2 8565 #define SQLITE_STMTSTATUS_AUTOINDEX 3 8566 #define SQLITE_STMTSTATUS_VM_STEP 4 8567 #define SQLITE_STMTSTATUS_REPREPARE 5 8568 #define SQLITE_STMTSTATUS_RUN 6 8569 #define SQLITE_STMTSTATUS_FILTER_MISS 7 8570 #define SQLITE_STMTSTATUS_FILTER_HIT 8 8571 #define SQLITE_STMTSTATUS_MEMUSED 99 8572 8573 /* 8574 ** CAPI3REF: Custom Page Cache Object 8575 ** 8576 ** The sqlite3_pcache type is opaque. It is implemented by 8577 ** the pluggable module. The SQLite core has no knowledge of 8578 ** its size or internal structure and never deals with the 8579 ** sqlite3_pcache object except by holding and passing pointers 8580 ** to the object. 8581 ** 8582 ** See [sqlite3_pcache_methods2] for additional information. 8583 */ 8584 typedef struct sqlite3_pcache sqlite3_pcache; 8585 8586 /* 8587 ** CAPI3REF: Custom Page Cache Object 8588 ** 8589 ** The sqlite3_pcache_page object represents a single page in the 8590 ** page cache. The page cache will allocate instances of this 8591 ** object. Various methods of the page cache use pointers to instances 8592 ** of this object as parameters or as their return value. 8593 ** 8594 ** See [sqlite3_pcache_methods2] for additional information. 8595 */ 8596 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 8597 struct sqlite3_pcache_page { 8598 void *pBuf; /* The content of the page */ 8599 void *pExtra; /* Extra information associated with the page */ 8600 }; 8601 8602 /* 8603 ** CAPI3REF: Application Defined Page Cache. 8604 ** KEYWORDS: {page cache} 8605 ** 8606 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 8607 ** register an alternative page cache implementation by passing in an 8608 ** instance of the sqlite3_pcache_methods2 structure.)^ 8609 ** In many applications, most of the heap memory allocated by 8610 ** SQLite is used for the page cache. 8611 ** By implementing a 8612 ** custom page cache using this API, an application can better control 8613 ** the amount of memory consumed by SQLite, the way in which 8614 ** that memory is allocated and released, and the policies used to 8615 ** determine exactly which parts of a database file are cached and for 8616 ** how long. 8617 ** 8618 ** The alternative page cache mechanism is an 8619 ** extreme measure that is only needed by the most demanding applications. 8620 ** The built-in page cache is recommended for most uses. 8621 ** 8622 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 8623 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 8624 ** the application may discard the parameter after the call to 8625 ** [sqlite3_config()] returns.)^ 8626 ** 8627 ** [[the xInit() page cache method]] 8628 ** ^(The xInit() method is called once for each effective 8629 ** call to [sqlite3_initialize()])^ 8630 ** (usually only once during the lifetime of the process). ^(The xInit() 8631 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8632 ** The intent of the xInit() method is to set up global data structures 8633 ** required by the custom page cache implementation. 8634 ** ^(If the xInit() method is NULL, then the 8635 ** built-in default page cache is used instead of the application defined 8636 ** page cache.)^ 8637 ** 8638 ** [[the xShutdown() page cache method]] 8639 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 8640 ** It can be used to clean up 8641 ** any outstanding resources before process shutdown, if required. 8642 ** ^The xShutdown() method may be NULL. 8643 ** 8644 ** ^SQLite automatically serializes calls to the xInit method, 8645 ** so the xInit method need not be threadsafe. ^The 8646 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 8647 ** not need to be threadsafe either. All other methods must be threadsafe 8648 ** in multithreaded applications. 8649 ** 8650 ** ^SQLite will never invoke xInit() more than once without an intervening 8651 ** call to xShutdown(). 8652 ** 8653 ** [[the xCreate() page cache methods]] 8654 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 8655 ** SQLite will typically create one cache instance for each open database file, 8656 ** though this is not guaranteed. ^The 8657 ** first parameter, szPage, is the size in bytes of the pages that must 8658 ** be allocated by the cache. ^szPage will always a power of two. ^The 8659 ** second parameter szExtra is a number of bytes of extra storage 8660 ** associated with each page cache entry. ^The szExtra parameter will 8661 ** a number less than 250. SQLite will use the 8662 ** extra szExtra bytes on each page to store metadata about the underlying 8663 ** database page on disk. The value passed into szExtra depends 8664 ** on the SQLite version, the target platform, and how SQLite was compiled. 8665 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 8666 ** created will be used to cache database pages of a file stored on disk, or 8667 ** false if it is used for an in-memory database. The cache implementation 8668 ** does not have to do anything special based with the value of bPurgeable; 8669 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 8670 ** never invoke xUnpin() except to deliberately delete a page. 8671 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 8672 ** false will always have the "discard" flag set to true. 8673 ** ^Hence, a cache created with bPurgeable false will 8674 ** never contain any unpinned pages. 8675 ** 8676 ** [[the xCachesize() page cache method]] 8677 ** ^(The xCachesize() method may be called at any time by SQLite to set the 8678 ** suggested maximum cache-size (number of pages stored by) the cache 8679 ** instance passed as the first argument. This is the value configured using 8680 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 8681 ** parameter, the implementation is not required to do anything with this 8682 ** value; it is advisory only. 8683 ** 8684 ** [[the xPagecount() page cache methods]] 8685 ** The xPagecount() method must return the number of pages currently 8686 ** stored in the cache, both pinned and unpinned. 8687 ** 8688 ** [[the xFetch() page cache methods]] 8689 ** The xFetch() method locates a page in the cache and returns a pointer to 8690 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 8691 ** The pBuf element of the returned sqlite3_pcache_page object will be a 8692 ** pointer to a buffer of szPage bytes used to store the content of a 8693 ** single database page. The pExtra element of sqlite3_pcache_page will be 8694 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 8695 ** for each entry in the page cache. 8696 ** 8697 ** The page to be fetched is determined by the key. ^The minimum key value 8698 ** is 1. After it has been retrieved using xFetch, the page is considered 8699 ** to be "pinned". 8700 ** 8701 ** If the requested page is already in the page cache, then the page cache 8702 ** implementation must return a pointer to the page buffer with its content 8703 ** intact. If the requested page is not already in the cache, then the 8704 ** cache implementation should use the value of the createFlag 8705 ** parameter to help it determined what action to take: 8706 ** 8707 ** <table border=1 width=85% align=center> 8708 ** <tr><th> createFlag <th> Behavior when page is not already in cache 8709 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 8710 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 8711 ** Otherwise return NULL. 8712 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 8713 ** NULL if allocating a new page is effectively impossible. 8714 ** </table> 8715 ** 8716 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 8717 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 8718 ** failed.)^ In between the xFetch() calls, SQLite may 8719 ** attempt to unpin one or more cache pages by spilling the content of 8720 ** pinned pages to disk and synching the operating system disk cache. 8721 ** 8722 ** [[the xUnpin() page cache method]] 8723 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 8724 ** as its second argument. If the third parameter, discard, is non-zero, 8725 ** then the page must be evicted from the cache. 8726 ** ^If the discard parameter is 8727 ** zero, then the page may be discarded or retained at the discretion of 8728 ** page cache implementation. ^The page cache implementation 8729 ** may choose to evict unpinned pages at any time. 8730 ** 8731 ** The cache must not perform any reference counting. A single 8732 ** call to xUnpin() unpins the page regardless of the number of prior calls 8733 ** to xFetch(). 8734 ** 8735 ** [[the xRekey() page cache methods]] 8736 ** The xRekey() method is used to change the key value associated with the 8737 ** page passed as the second argument. If the cache 8738 ** previously contains an entry associated with newKey, it must be 8739 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 8740 ** to be pinned. 8741 ** 8742 ** When SQLite calls the xTruncate() method, the cache must discard all 8743 ** existing cache entries with page numbers (keys) greater than or equal 8744 ** to the value of the iLimit parameter passed to xTruncate(). If any 8745 ** of these pages are pinned, they are implicitly unpinned, meaning that 8746 ** they can be safely discarded. 8747 ** 8748 ** [[the xDestroy() page cache method]] 8749 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 8750 ** All resources associated with the specified cache should be freed. ^After 8751 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 8752 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 8753 ** functions. 8754 ** 8755 ** [[the xShrink() page cache method]] 8756 ** ^SQLite invokes the xShrink() method when it wants the page cache to 8757 ** free up as much of heap memory as possible. The page cache implementation 8758 ** is not obligated to free any memory, but well-behaved implementations should 8759 ** do their best. 8760 */ 8761 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 8762 struct sqlite3_pcache_methods2 { 8763 int iVersion; 8764 void *pArg; 8765 int (*xInit)(void*); 8766 void (*xShutdown)(void*); 8767 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 8768 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8769 int (*xPagecount)(sqlite3_pcache*); 8770 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8771 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 8772 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 8773 unsigned oldKey, unsigned newKey); 8774 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8775 void (*xDestroy)(sqlite3_pcache*); 8776 void (*xShrink)(sqlite3_pcache*); 8777 }; 8778 8779 /* 8780 ** This is the obsolete pcache_methods object that has now been replaced 8781 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8782 ** retained in the header file for backwards compatibility only. 8783 */ 8784 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8785 struct sqlite3_pcache_methods { 8786 void *pArg; 8787 int (*xInit)(void*); 8788 void (*xShutdown)(void*); 8789 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8790 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8791 int (*xPagecount)(sqlite3_pcache*); 8792 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8793 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8794 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8795 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8796 void (*xDestroy)(sqlite3_pcache*); 8797 }; 8798 8799 8800 /* 8801 ** CAPI3REF: Online Backup Object 8802 ** 8803 ** The sqlite3_backup object records state information about an ongoing 8804 ** online backup operation. ^The sqlite3_backup object is created by 8805 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 8806 ** [sqlite3_backup_finish()]. 8807 ** 8808 ** See Also: [Using the SQLite Online Backup API] 8809 */ 8810 typedef struct sqlite3_backup sqlite3_backup; 8811 8812 /* 8813 ** CAPI3REF: Online Backup API. 8814 ** 8815 ** The backup API copies the content of one database into another. 8816 ** It is useful either for creating backups of databases or 8817 ** for copying in-memory databases to or from persistent files. 8818 ** 8819 ** See Also: [Using the SQLite Online Backup API] 8820 ** 8821 ** ^SQLite holds a write transaction open on the destination database file 8822 ** for the duration of the backup operation. 8823 ** ^The source database is read-locked only while it is being read; 8824 ** it is not locked continuously for the entire backup operation. 8825 ** ^Thus, the backup may be performed on a live source database without 8826 ** preventing other database connections from 8827 ** reading or writing to the source database while the backup is underway. 8828 ** 8829 ** ^(To perform a backup operation: 8830 ** <ol> 8831 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8832 ** backup, 8833 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8834 ** the data between the two databases, and finally 8835 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8836 ** associated with the backup operation. 8837 ** </ol>)^ 8838 ** There should be exactly one call to sqlite3_backup_finish() for each 8839 ** successful call to sqlite3_backup_init(). 8840 ** 8841 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8842 ** 8843 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8844 ** [database connection] associated with the destination database 8845 ** and the database name, respectively. 8846 ** ^The database name is "main" for the main database, "temp" for the 8847 ** temporary database, or the name specified after the AS keyword in 8848 ** an [ATTACH] statement for an attached database. 8849 ** ^The S and M arguments passed to 8850 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8851 ** and database name of the source database, respectively. 8852 ** ^The source and destination [database connections] (parameters S and D) 8853 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8854 ** an error. 8855 ** 8856 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8857 ** there is already a read or read-write transaction open on the 8858 ** destination database. 8859 ** 8860 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8861 ** returned and an error code and error message are stored in the 8862 ** destination [database connection] D. 8863 ** ^The error code and message for the failed call to sqlite3_backup_init() 8864 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8865 ** [sqlite3_errmsg16()] functions. 8866 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 8867 ** [sqlite3_backup] object. 8868 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8869 ** sqlite3_backup_finish() functions to perform the specified backup 8870 ** operation. 8871 ** 8872 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8873 ** 8874 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8875 ** the source and destination databases specified by [sqlite3_backup] object B. 8876 ** ^If N is negative, all remaining source pages are copied. 8877 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8878 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 8879 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8880 ** from source to destination, then it returns [SQLITE_DONE]. 8881 ** ^If an error occurs while running sqlite3_backup_step(B,N), 8882 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 8883 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8884 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8885 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8886 ** 8887 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8888 ** <ol> 8889 ** <li> the destination database was opened read-only, or 8890 ** <li> the destination database is using write-ahead-log journaling 8891 ** and the destination and source page sizes differ, or 8892 ** <li> the destination database is an in-memory database and the 8893 ** destination and source page sizes differ. 8894 ** </ol>)^ 8895 ** 8896 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8897 ** the [sqlite3_busy_handler | busy-handler function] 8898 ** is invoked (if one is specified). ^If the 8899 ** busy-handler returns non-zero before the lock is available, then 8900 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8901 ** sqlite3_backup_step() can be retried later. ^If the source 8902 ** [database connection] 8903 ** is being used to write to the source database when sqlite3_backup_step() 8904 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8905 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 8906 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8907 ** [SQLITE_READONLY] is returned, then 8908 ** there is no point in retrying the call to sqlite3_backup_step(). These 8909 ** errors are considered fatal.)^ The application must accept 8910 ** that the backup operation has failed and pass the backup operation handle 8911 ** to the sqlite3_backup_finish() to release associated resources. 8912 ** 8913 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8914 ** on the destination file. ^The exclusive lock is not released until either 8915 ** sqlite3_backup_finish() is called or the backup operation is complete 8916 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8917 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 8918 ** lasts for the duration of the sqlite3_backup_step() call. 8919 ** ^Because the source database is not locked between calls to 8920 ** sqlite3_backup_step(), the source database may be modified mid-way 8921 ** through the backup process. ^If the source database is modified by an 8922 ** external process or via a database connection other than the one being 8923 ** used by the backup operation, then the backup will be automatically 8924 ** restarted by the next call to sqlite3_backup_step(). ^If the source 8925 ** database is modified by the using the same database connection as is used 8926 ** by the backup operation, then the backup database is automatically 8927 ** updated at the same time. 8928 ** 8929 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8930 ** 8931 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8932 ** application wishes to abandon the backup operation, the application 8933 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8934 ** ^The sqlite3_backup_finish() interfaces releases all 8935 ** resources associated with the [sqlite3_backup] object. 8936 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8937 ** active write-transaction on the destination database is rolled back. 8938 ** The [sqlite3_backup] object is invalid 8939 ** and may not be used following a call to sqlite3_backup_finish(). 8940 ** 8941 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8942 ** sqlite3_backup_step() errors occurred, regardless or whether or not 8943 ** sqlite3_backup_step() completed. 8944 ** ^If an out-of-memory condition or IO error occurred during any prior 8945 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8946 ** sqlite3_backup_finish() returns the corresponding [error code]. 8947 ** 8948 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8949 ** is not a permanent error and does not affect the return value of 8950 ** sqlite3_backup_finish(). 8951 ** 8952 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8953 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8954 ** 8955 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 8956 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8957 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8958 ** in the source database at the conclusion of the most recent 8959 ** sqlite3_backup_step(). 8960 ** ^(The values returned by these functions are only updated by 8961 ** sqlite3_backup_step(). If the source database is modified in a way that 8962 ** changes the size of the source database or the number of pages remaining, 8963 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 8964 ** and sqlite3_backup_remaining() until after the next 8965 ** sqlite3_backup_step().)^ 8966 ** 8967 ** <b>Concurrent Usage of Database Handles</b> 8968 ** 8969 ** ^The source [database connection] may be used by the application for other 8970 ** purposes while a backup operation is underway or being initialized. 8971 ** ^If SQLite is compiled and configured to support threadsafe database 8972 ** connections, then the source database connection may be used concurrently 8973 ** from within other threads. 8974 ** 8975 ** However, the application must guarantee that the destination 8976 ** [database connection] is not passed to any other API (by any thread) after 8977 ** sqlite3_backup_init() is called and before the corresponding call to 8978 ** sqlite3_backup_finish(). SQLite does not currently check to see 8979 ** if the application incorrectly accesses the destination [database connection] 8980 ** and so no error code is reported, but the operations may malfunction 8981 ** nevertheless. Use of the destination database connection while a 8982 ** backup is in progress might also also cause a mutex deadlock. 8983 ** 8984 ** If running in [shared cache mode], the application must 8985 ** guarantee that the shared cache used by the destination database 8986 ** is not accessed while the backup is running. In practice this means 8987 ** that the application must guarantee that the disk file being 8988 ** backed up to is not accessed by any connection within the process, 8989 ** not just the specific connection that was passed to sqlite3_backup_init(). 8990 ** 8991 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8992 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8993 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8994 ** APIs are not strictly speaking threadsafe. If they are invoked at the 8995 ** same time as another thread is invoking sqlite3_backup_step() it is 8996 ** possible that they return invalid values. 8997 */ 8998 SQLITE_API sqlite3_backup *sqlite3_backup_init( 8999 sqlite3 *pDest, /* Destination database handle */ 9000 const char *zDestName, /* Destination database name */ 9001 sqlite3 *pSource, /* Source database handle */ 9002 const char *zSourceName /* Source database name */ 9003 ); 9004 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 9005 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 9006 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 9007 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 9008 9009 /* 9010 ** CAPI3REF: Unlock Notification 9011 ** METHOD: sqlite3 9012 ** 9013 ** ^When running in shared-cache mode, a database operation may fail with 9014 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 9015 ** individual tables within the shared-cache cannot be obtained. See 9016 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 9017 ** ^This API may be used to register a callback that SQLite will invoke 9018 ** when the connection currently holding the required lock relinquishes it. 9019 ** ^This API is only available if the library was compiled with the 9020 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 9021 ** 9022 ** See Also: [Using the SQLite Unlock Notification Feature]. 9023 ** 9024 ** ^Shared-cache locks are released when a database connection concludes 9025 ** its current transaction, either by committing it or rolling it back. 9026 ** 9027 ** ^When a connection (known as the blocked connection) fails to obtain a 9028 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 9029 ** identity of the database connection (the blocking connection) that 9030 ** has locked the required resource is stored internally. ^After an 9031 ** application receives an SQLITE_LOCKED error, it may call the 9032 ** sqlite3_unlock_notify() method with the blocked connection handle as 9033 ** the first argument to register for a callback that will be invoked 9034 ** when the blocking connections current transaction is concluded. ^The 9035 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 9036 ** call that concludes the blocking connection's transaction. 9037 ** 9038 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 9039 ** there is a chance that the blocking connection will have already 9040 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 9041 ** If this happens, then the specified callback is invoked immediately, 9042 ** from within the call to sqlite3_unlock_notify().)^ 9043 ** 9044 ** ^If the blocked connection is attempting to obtain a write-lock on a 9045 ** shared-cache table, and more than one other connection currently holds 9046 ** a read-lock on the same table, then SQLite arbitrarily selects one of 9047 ** the other connections to use as the blocking connection. 9048 ** 9049 ** ^(There may be at most one unlock-notify callback registered by a 9050 ** blocked connection. If sqlite3_unlock_notify() is called when the 9051 ** blocked connection already has a registered unlock-notify callback, 9052 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 9053 ** called with a NULL pointer as its second argument, then any existing 9054 ** unlock-notify callback is canceled. ^The blocked connections 9055 ** unlock-notify callback may also be canceled by closing the blocked 9056 ** connection using [sqlite3_close()]. 9057 ** 9058 ** The unlock-notify callback is not reentrant. If an application invokes 9059 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 9060 ** crash or deadlock may be the result. 9061 ** 9062 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 9063 ** returns SQLITE_OK. 9064 ** 9065 ** <b>Callback Invocation Details</b> 9066 ** 9067 ** When an unlock-notify callback is registered, the application provides a 9068 ** single void* pointer that is passed to the callback when it is invoked. 9069 ** However, the signature of the callback function allows SQLite to pass 9070 ** it an array of void* context pointers. The first argument passed to 9071 ** an unlock-notify callback is a pointer to an array of void* pointers, 9072 ** and the second is the number of entries in the array. 9073 ** 9074 ** When a blocking connection's transaction is concluded, there may be 9075 ** more than one blocked connection that has registered for an unlock-notify 9076 ** callback. ^If two or more such blocked connections have specified the 9077 ** same callback function, then instead of invoking the callback function 9078 ** multiple times, it is invoked once with the set of void* context pointers 9079 ** specified by the blocked connections bundled together into an array. 9080 ** This gives the application an opportunity to prioritize any actions 9081 ** related to the set of unblocked database connections. 9082 ** 9083 ** <b>Deadlock Detection</b> 9084 ** 9085 ** Assuming that after registering for an unlock-notify callback a 9086 ** database waits for the callback to be issued before taking any further 9087 ** action (a reasonable assumption), then using this API may cause the 9088 ** application to deadlock. For example, if connection X is waiting for 9089 ** connection Y's transaction to be concluded, and similarly connection 9090 ** Y is waiting on connection X's transaction, then neither connection 9091 ** will proceed and the system may remain deadlocked indefinitely. 9092 ** 9093 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 9094 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 9095 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 9096 ** unlock-notify callback is registered. The system is said to be in 9097 ** a deadlocked state if connection A has registered for an unlock-notify 9098 ** callback on the conclusion of connection B's transaction, and connection 9099 ** B has itself registered for an unlock-notify callback when connection 9100 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 9101 ** the system is also considered to be deadlocked if connection B has 9102 ** registered for an unlock-notify callback on the conclusion of connection 9103 ** C's transaction, where connection C is waiting on connection A. ^Any 9104 ** number of levels of indirection are allowed. 9105 ** 9106 ** <b>The "DROP TABLE" Exception</b> 9107 ** 9108 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 9109 ** always appropriate to call sqlite3_unlock_notify(). There is however, 9110 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 9111 ** SQLite checks if there are any currently executing SELECT statements 9112 ** that belong to the same connection. If there are, SQLITE_LOCKED is 9113 ** returned. In this case there is no "blocking connection", so invoking 9114 ** sqlite3_unlock_notify() results in the unlock-notify callback being 9115 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 9116 ** or "DROP INDEX" query, an infinite loop might be the result. 9117 ** 9118 ** One way around this problem is to check the extended error code returned 9119 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 9120 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 9121 ** the special "DROP TABLE/INDEX" case, the extended error code is just 9122 ** SQLITE_LOCKED.)^ 9123 */ 9124 SQLITE_API int sqlite3_unlock_notify( 9125 sqlite3 *pBlocked, /* Waiting connection */ 9126 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 9127 void *pNotifyArg /* Argument to pass to xNotify */ 9128 ); 9129 9130 9131 /* 9132 ** CAPI3REF: String Comparison 9133 ** 9134 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 9135 ** and extensions to compare the contents of two buffers containing UTF-8 9136 ** strings in a case-independent fashion, using the same definition of "case 9137 ** independence" that SQLite uses internally when comparing identifiers. 9138 */ 9139 SQLITE_API int sqlite3_stricmp(const char *, const char *); 9140 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 9141 9142 /* 9143 ** CAPI3REF: String Globbing 9144 * 9145 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 9146 ** string X matches the [GLOB] pattern P. 9147 ** ^The definition of [GLOB] pattern matching used in 9148 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 9149 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 9150 ** is case sensitive. 9151 ** 9152 ** Note that this routine returns zero on a match and non-zero if the strings 9153 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9154 ** 9155 ** See also: [sqlite3_strlike()]. 9156 */ 9157 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 9158 9159 /* 9160 ** CAPI3REF: String LIKE Matching 9161 * 9162 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 9163 ** string X matches the [LIKE] pattern P with escape character E. 9164 ** ^The definition of [LIKE] pattern matching used in 9165 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 9166 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 9167 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 9168 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 9169 ** insensitive - equivalent upper and lower case ASCII characters match 9170 ** one another. 9171 ** 9172 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 9173 ** only ASCII characters are case folded. 9174 ** 9175 ** Note that this routine returns zero on a match and non-zero if the strings 9176 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9177 ** 9178 ** See also: [sqlite3_strglob()]. 9179 */ 9180 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 9181 9182 /* 9183 ** CAPI3REF: Error Logging Interface 9184 ** 9185 ** ^The [sqlite3_log()] interface writes a message into the [error log] 9186 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 9187 ** ^If logging is enabled, the zFormat string and subsequent arguments are 9188 ** used with [sqlite3_snprintf()] to generate the final output string. 9189 ** 9190 ** The sqlite3_log() interface is intended for use by extensions such as 9191 ** virtual tables, collating functions, and SQL functions. While there is 9192 ** nothing to prevent an application from calling sqlite3_log(), doing so 9193 ** is considered bad form. 9194 ** 9195 ** The zFormat string must not be NULL. 9196 ** 9197 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 9198 ** will not use dynamically allocated memory. The log message is stored in 9199 ** a fixed-length buffer on the stack. If the log message is longer than 9200 ** a few hundred characters, it will be truncated to the length of the 9201 ** buffer. 9202 */ 9203 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 9204 9205 /* 9206 ** CAPI3REF: Write-Ahead Log Commit Hook 9207 ** METHOD: sqlite3 9208 ** 9209 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 9210 ** is invoked each time data is committed to a database in wal mode. 9211 ** 9212 ** ^(The callback is invoked by SQLite after the commit has taken place and 9213 ** the associated write-lock on the database released)^, so the implementation 9214 ** may read, write or [checkpoint] the database as required. 9215 ** 9216 ** ^The first parameter passed to the callback function when it is invoked 9217 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 9218 ** registering the callback. ^The second is a copy of the database handle. 9219 ** ^The third parameter is the name of the database that was written to - 9220 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 9221 ** is the number of pages currently in the write-ahead log file, 9222 ** including those that were just committed. 9223 ** 9224 ** The callback function should normally return [SQLITE_OK]. ^If an error 9225 ** code is returned, that error will propagate back up through the 9226 ** SQLite code base to cause the statement that provoked the callback 9227 ** to report an error, though the commit will have still occurred. If the 9228 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 9229 ** that does not correspond to any valid SQLite error code, the results 9230 ** are undefined. 9231 ** 9232 ** A single database handle may have at most a single write-ahead log callback 9233 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 9234 ** previously registered write-ahead log callback. ^The return value is 9235 ** a copy of the third parameter from the previous call, if any, or 0. 9236 ** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the 9237 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 9238 ** overwrite any prior [sqlite3_wal_hook()] settings. 9239 */ 9240 SQLITE_API void *sqlite3_wal_hook( 9241 sqlite3*, 9242 int(*)(void *,sqlite3*,const char*,int), 9243 void* 9244 ); 9245 9246 /* 9247 ** CAPI3REF: Configure an auto-checkpoint 9248 ** METHOD: sqlite3 9249 ** 9250 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 9251 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 9252 ** to automatically [checkpoint] 9253 ** after committing a transaction if there are N or 9254 ** more frames in the [write-ahead log] file. ^Passing zero or 9255 ** a negative value as the nFrame parameter disables automatic 9256 ** checkpoints entirely. 9257 ** 9258 ** ^The callback registered by this function replaces any existing callback 9259 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 9260 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 9261 ** configured by this function. 9262 ** 9263 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 9264 ** from SQL. 9265 ** 9266 ** ^Checkpoints initiated by this mechanism are 9267 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 9268 ** 9269 ** ^Every new [database connection] defaults to having the auto-checkpoint 9270 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 9271 ** pages. The use of this interface 9272 ** is only necessary if the default setting is found to be suboptimal 9273 ** for a particular application. 9274 */ 9275 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 9276 9277 /* 9278 ** CAPI3REF: Checkpoint a database 9279 ** METHOD: sqlite3 9280 ** 9281 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 9282 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 9283 ** 9284 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 9285 ** [write-ahead log] for database X on [database connection] D to be 9286 ** transferred into the database file and for the write-ahead log to 9287 ** be reset. See the [checkpointing] documentation for addition 9288 ** information. 9289 ** 9290 ** This interface used to be the only way to cause a checkpoint to 9291 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 9292 ** interface was added. This interface is retained for backwards 9293 ** compatibility and as a convenience for applications that need to manually 9294 ** start a callback but which do not need the full power (and corresponding 9295 ** complication) of [sqlite3_wal_checkpoint_v2()]. 9296 */ 9297 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 9298 9299 /* 9300 ** CAPI3REF: Checkpoint a database 9301 ** METHOD: sqlite3 9302 ** 9303 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 9304 ** operation on database X of [database connection] D in mode M. Status 9305 ** information is written back into integers pointed to by L and C.)^ 9306 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 9307 ** 9308 ** <dl> 9309 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 9310 ** ^Checkpoint as many frames as possible without waiting for any database 9311 ** readers or writers to finish, then sync the database file if all frames 9312 ** in the log were checkpointed. ^The [busy-handler callback] 9313 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 9314 ** ^On the other hand, passive mode might leave the checkpoint unfinished 9315 ** if there are concurrent readers or writers. 9316 ** 9317 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 9318 ** ^This mode blocks (it invokes the 9319 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 9320 ** database writer and all readers are reading from the most recent database 9321 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 9322 ** database file. ^This mode blocks new database writers while it is pending, 9323 ** but new database readers are allowed to continue unimpeded. 9324 ** 9325 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 9326 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 9327 ** that after checkpointing the log file it blocks (calls the 9328 ** [busy-handler callback]) 9329 ** until all readers are reading from the database file only. ^This ensures 9330 ** that the next writer will restart the log file from the beginning. 9331 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 9332 ** database writer attempts while it is pending, but does not impede readers. 9333 ** 9334 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 9335 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 9336 ** addition that it also truncates the log file to zero bytes just prior 9337 ** to a successful return. 9338 ** </dl> 9339 ** 9340 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 9341 ** the log file or to -1 if the checkpoint could not run because 9342 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 9343 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 9344 ** log file (including any that were already checkpointed before the function 9345 ** was called) or to -1 if the checkpoint could not run due to an error or 9346 ** because the database is not in WAL mode. ^Note that upon successful 9347 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 9348 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 9349 ** 9350 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 9351 ** any other process is running a checkpoint operation at the same time, the 9352 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 9353 ** busy-handler configured, it will not be invoked in this case. 9354 ** 9355 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 9356 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 9357 ** obtained immediately, and a busy-handler is configured, it is invoked and 9358 ** the writer lock retried until either the busy-handler returns 0 or the lock 9359 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 9360 ** database readers as described above. ^If the busy-handler returns 0 before 9361 ** the writer lock is obtained or while waiting for database readers, the 9362 ** checkpoint operation proceeds from that point in the same way as 9363 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 9364 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 9365 ** 9366 ** ^If parameter zDb is NULL or points to a zero length string, then the 9367 ** specified operation is attempted on all WAL databases [attached] to 9368 ** [database connection] db. In this case the 9369 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 9370 ** an SQLITE_BUSY error is encountered when processing one or more of the 9371 ** attached WAL databases, the operation is still attempted on any remaining 9372 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 9373 ** error occurs while processing an attached database, processing is abandoned 9374 ** and the error code is returned to the caller immediately. ^If no error 9375 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 9376 ** databases, SQLITE_OK is returned. 9377 ** 9378 ** ^If database zDb is the name of an attached database that is not in WAL 9379 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 9380 ** zDb is not NULL (or a zero length string) and is not the name of any 9381 ** attached database, SQLITE_ERROR is returned to the caller. 9382 ** 9383 ** ^Unless it returns SQLITE_MISUSE, 9384 ** the sqlite3_wal_checkpoint_v2() interface 9385 ** sets the error information that is queried by 9386 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 9387 ** 9388 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 9389 ** from SQL. 9390 */ 9391 SQLITE_API int sqlite3_wal_checkpoint_v2( 9392 sqlite3 *db, /* Database handle */ 9393 const char *zDb, /* Name of attached database (or NULL) */ 9394 int eMode, /* SQLITE_CHECKPOINT_* value */ 9395 int *pnLog, /* OUT: Size of WAL log in frames */ 9396 int *pnCkpt /* OUT: Total number of frames checkpointed */ 9397 ); 9398 9399 /* 9400 ** CAPI3REF: Checkpoint Mode Values 9401 ** KEYWORDS: {checkpoint mode} 9402 ** 9403 ** These constants define all valid values for the "checkpoint mode" passed 9404 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 9405 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 9406 ** meaning of each of these checkpoint modes. 9407 */ 9408 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 9409 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 9410 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 9411 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 9412 9413 /* 9414 ** CAPI3REF: Virtual Table Interface Configuration 9415 ** 9416 ** This function may be called by either the [xConnect] or [xCreate] method 9417 ** of a [virtual table] implementation to configure 9418 ** various facets of the virtual table interface. 9419 ** 9420 ** If this interface is invoked outside the context of an xConnect or 9421 ** xCreate virtual table method then the behavior is undefined. 9422 ** 9423 ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the 9424 ** [database connection] in which the virtual table is being created and 9425 ** which is passed in as the first argument to the [xConnect] or [xCreate] 9426 ** method that is invoking sqlite3_vtab_config(). The C parameter is one 9427 ** of the [virtual table configuration options]. The presence and meaning 9428 ** of parameters after C depend on which [virtual table configuration option] 9429 ** is used. 9430 */ 9431 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 9432 9433 /* 9434 ** CAPI3REF: Virtual Table Configuration Options 9435 ** KEYWORDS: {virtual table configuration options} 9436 ** KEYWORDS: {virtual table configuration option} 9437 ** 9438 ** These macros define the various options to the 9439 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 9440 ** can use to customize and optimize their behavior. 9441 ** 9442 ** <dl> 9443 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 9444 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> 9445 ** <dd>Calls of the form 9446 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 9447 ** where X is an integer. If X is zero, then the [virtual table] whose 9448 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 9449 ** support constraints. In this configuration (which is the default) if 9450 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 9451 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 9452 ** specified as part of the users SQL statement, regardless of the actual 9453 ** ON CONFLICT mode specified. 9454 ** 9455 ** If X is non-zero, then the virtual table implementation guarantees 9456 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 9457 ** any modifications to internal or persistent data structures have been made. 9458 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 9459 ** is able to roll back a statement or database transaction, and abandon 9460 ** or continue processing the current SQL statement as appropriate. 9461 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 9462 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 9463 ** had been ABORT. 9464 ** 9465 ** Virtual table implementations that are required to handle OR REPLACE 9466 ** must do so within the [xUpdate] method. If a call to the 9467 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 9468 ** CONFLICT policy is REPLACE, the virtual table implementation should 9469 ** silently replace the appropriate rows within the xUpdate callback and 9470 ** return SQLITE_OK. Or, if this is not possible, it may return 9471 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 9472 ** constraint handling. 9473 ** </dd> 9474 ** 9475 ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt> 9476 ** <dd>Calls of the form 9477 ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the 9478 ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9479 ** prohibits that virtual table from being used from within triggers and 9480 ** views. 9481 ** </dd> 9482 ** 9483 ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt> 9484 ** <dd>Calls of the form 9485 ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the 9486 ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9487 ** identify that virtual table as being safe to use from within triggers 9488 ** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the 9489 ** virtual table can do no serious harm even if it is controlled by a 9490 ** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS 9491 ** flag unless absolutely necessary. 9492 ** </dd> 9493 ** </dl> 9494 */ 9495 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 9496 #define SQLITE_VTAB_INNOCUOUS 2 9497 #define SQLITE_VTAB_DIRECTONLY 3 9498 9499 /* 9500 ** CAPI3REF: Determine The Virtual Table Conflict Policy 9501 ** 9502 ** This function may only be called from within a call to the [xUpdate] method 9503 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 9504 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 9505 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 9506 ** of the SQL statement that triggered the call to the [xUpdate] method of the 9507 ** [virtual table]. 9508 */ 9509 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 9510 9511 /* 9512 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 9513 ** 9514 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 9515 ** method of a [virtual table], then it might return true if the 9516 ** column is being fetched as part of an UPDATE operation during which the 9517 ** column value will not change. The virtual table implementation can use 9518 ** this hint as permission to substitute a return value that is less 9519 ** expensive to compute and that the corresponding 9520 ** [xUpdate] method understands as a "no-change" value. 9521 ** 9522 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 9523 ** the column is not changed by the UPDATE statement, then the xColumn 9524 ** method can optionally return without setting a result, without calling 9525 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 9526 ** In that case, [sqlite3_value_nochange(X)] will return true for the 9527 ** same column in the [xUpdate] method. 9528 ** 9529 ** The sqlite3_vtab_nochange() routine is an optimization. Virtual table 9530 ** implementations should continue to give a correct answer even if the 9531 ** sqlite3_vtab_nochange() interface were to always return false. In the 9532 ** current implementation, the sqlite3_vtab_nochange() interface does always 9533 ** returns false for the enhanced [UPDATE FROM] statement. 9534 */ 9535 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 9536 9537 /* 9538 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint 9539 ** METHOD: sqlite3_index_info 9540 ** 9541 ** This function may only be called from within a call to the [xBestIndex] 9542 ** method of a [virtual table]. This function returns a pointer to a string 9543 ** that is the name of the appropriate collation sequence to use for text 9544 ** comparisons on the constraint identified by its arguments. 9545 ** 9546 ** The first argument must be the pointer to the [sqlite3_index_info] object 9547 ** that is the first parameter to the xBestIndex() method. The second argument 9548 ** must be an index into the aConstraint[] array belonging to the 9549 ** sqlite3_index_info structure passed to xBestIndex. 9550 ** 9551 ** Important: 9552 ** The first parameter must be the same pointer that is passed into the 9553 ** xBestMethod() method. The first parameter may not be a pointer to a 9554 ** different [sqlite3_index_info] object, even an exact copy. 9555 ** 9556 ** The return value is computed as follows: 9557 ** 9558 ** <ol> 9559 ** <li><p> If the constraint comes from a WHERE clause expression that contains 9560 ** a [COLLATE operator], then the name of the collation specified by 9561 ** that COLLATE operator is returned. 9562 ** <li><p> If there is no COLLATE operator, but the column that is the subject 9563 ** of the constraint specifies an alternative collating sequence via 9564 ** a [COLLATE clause] on the column definition within the CREATE TABLE 9565 ** statement that was passed into [sqlite3_declare_vtab()], then the 9566 ** name of that alternative collating sequence is returned. 9567 ** <li><p> Otherwise, "BINARY" is returned. 9568 ** </ol> 9569 */ 9570 SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 9571 9572 /* 9573 ** CAPI3REF: Determine if a virtual table query is DISTINCT 9574 ** METHOD: sqlite3_index_info 9575 ** 9576 ** This API may only be used from within an [xBestIndex|xBestIndex method] 9577 ** of a [virtual table] implementation. The result of calling this 9578 ** interface from outside of xBestIndex() is undefined and probably harmful. 9579 ** 9580 ** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and 9581 ** 3. The integer returned by sqlite3_vtab_distinct() 9582 ** gives the virtual table additional information about how the query 9583 ** planner wants the output to be ordered. As long as the virtual table 9584 ** can meet the ordering requirements of the query planner, it may set 9585 ** the "orderByConsumed" flag. 9586 ** 9587 ** <ol><li value="0"><p> 9588 ** ^If the sqlite3_vtab_distinct() interface returns 0, that means 9589 ** that the query planner needs the virtual table to return all rows in the 9590 ** sort order defined by the "nOrderBy" and "aOrderBy" fields of the 9591 ** [sqlite3_index_info] object. This is the default expectation. If the 9592 ** virtual table outputs all rows in sorted order, then it is always safe for 9593 ** the xBestIndex method to set the "orderByConsumed" flag, regardless of 9594 ** the return value from sqlite3_vtab_distinct(). 9595 ** <li value="1"><p> 9596 ** ^(If the sqlite3_vtab_distinct() interface returns 1, that means 9597 ** that the query planner does not need the rows to be returned in sorted order 9598 ** as long as all rows with the same values in all columns identified by the 9599 ** "aOrderBy" field are adjacent.)^ This mode is used when the query planner 9600 ** is doing a GROUP BY. 9601 ** <li value="2"><p> 9602 ** ^(If the sqlite3_vtab_distinct() interface returns 2, that means 9603 ** that the query planner does not need the rows returned in any particular 9604 ** order, as long as rows with the same values in all "aOrderBy" columns 9605 ** are adjacent.)^ ^(Furthermore, only a single row for each particular 9606 ** combination of values in the columns identified by the "aOrderBy" field 9607 ** needs to be returned.)^ ^It is always ok for two or more rows with the same 9608 ** values in all "aOrderBy" columns to be returned, as long as all such rows 9609 ** are adjacent. ^The virtual table may, if it chooses, omit extra rows 9610 ** that have the same value for all columns identified by "aOrderBy". 9611 ** ^However omitting the extra rows is optional. 9612 ** This mode is used for a DISTINCT query. 9613 ** <li value="3"><p> 9614 ** ^(If the sqlite3_vtab_distinct() interface returns 3, that means 9615 ** that the query planner needs only distinct rows but it does need the 9616 ** rows to be sorted.)^ ^The virtual table implementation is free to omit 9617 ** rows that are identical in all aOrderBy columns, if it wants to, but 9618 ** it is not required to omit any rows. This mode is used for queries 9619 ** that have both DISTINCT and ORDER BY clauses. 9620 ** </ol> 9621 ** 9622 ** ^For the purposes of comparing virtual table output values to see if the 9623 ** values are same value for sorting purposes, two NULL values are considered 9624 ** to be the same. In other words, the comparison operator is "IS" 9625 ** (or "IS NOT DISTINCT FROM") and not "==". 9626 ** 9627 ** If a virtual table implementation is unable to meet the requirements 9628 ** specified above, then it must not set the "orderByConsumed" flag in the 9629 ** [sqlite3_index_info] object or an incorrect answer may result. 9630 ** 9631 ** ^A virtual table implementation is always free to return rows in any order 9632 ** it wants, as long as the "orderByConsumed" flag is not set. ^When the 9633 ** the "orderByConsumed" flag is unset, the query planner will add extra 9634 ** [bytecode] to ensure that the final results returned by the SQL query are 9635 ** ordered correctly. The use of the "orderByConsumed" flag and the 9636 ** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful 9637 ** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed" 9638 ** flag might help queries against a virtual table to run faster. Being 9639 ** overly aggressive and setting the "orderByConsumed" flag when it is not 9640 ** valid to do so, on the other hand, might cause SQLite to return incorrect 9641 ** results. 9642 */ 9643 SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*); 9644 9645 /* 9646 ** CAPI3REF: Identify and handle IN constraints in xBestIndex 9647 ** 9648 ** This interface may only be used from within an 9649 ** [xBestIndex|xBestIndex() method] of a [virtual table] implementation. 9650 ** The result of invoking this interface from any other context is 9651 ** undefined and probably harmful. 9652 ** 9653 ** ^(A constraint on a virtual table of the form 9654 ** "[IN operator|column IN (...)]" is 9655 ** communicated to the xBestIndex method as a 9656 ** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use 9657 ** this constraint, it must set the corresponding 9658 ** aConstraintUsage[].argvIndex to a postive integer. ^(Then, under 9659 ** the usual mode of handling IN operators, SQLite generates [bytecode] 9660 ** that invokes the [xFilter|xFilter() method] once for each value 9661 ** on the right-hand side of the IN operator.)^ Thus the virtual table 9662 ** only sees a single value from the right-hand side of the IN operator 9663 ** at a time. 9664 ** 9665 ** In some cases, however, it would be advantageous for the virtual 9666 ** table to see all values on the right-hand of the IN operator all at 9667 ** once. The sqlite3_vtab_in() interfaces facilitates this in two ways: 9668 ** 9669 ** <ol> 9670 ** <li><p> 9671 ** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero) 9672 ** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint 9673 ** is an [IN operator] that can be processed all at once. ^In other words, 9674 ** sqlite3_vtab_in() with -1 in the third argument is a mechanism 9675 ** by which the virtual table can ask SQLite if all-at-once processing 9676 ** of the IN operator is even possible. 9677 ** 9678 ** <li><p> 9679 ** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates 9680 ** to SQLite that the virtual table does or does not want to process 9681 ** the IN operator all-at-once, respectively. ^Thus when the third 9682 ** parameter (F) is non-negative, this interface is the mechanism by 9683 ** which the virtual table tells SQLite how it wants to process the 9684 ** IN operator. 9685 ** </ol> 9686 ** 9687 ** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times 9688 ** within the same xBestIndex method call. ^For any given P,N pair, 9689 ** the return value from sqlite3_vtab_in(P,N,F) will always be the same 9690 ** within the same xBestIndex call. ^If the interface returns true 9691 ** (non-zero), that means that the constraint is an IN operator 9692 ** that can be processed all-at-once. ^If the constraint is not an IN 9693 ** operator or cannot be processed all-at-once, then the interface returns 9694 ** false. 9695 ** 9696 ** ^(All-at-once processing of the IN operator is selected if both of the 9697 ** following conditions are met: 9698 ** 9699 ** <ol> 9700 ** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive 9701 ** integer. This is how the virtual table tells SQLite that it wants to 9702 ** use the N-th constraint. 9703 ** 9704 ** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was 9705 ** non-negative had F>=1. 9706 ** </ol>)^ 9707 ** 9708 ** ^If either or both of the conditions above are false, then SQLite uses 9709 ** the traditional one-at-a-time processing strategy for the IN constraint. 9710 ** ^If both conditions are true, then the argvIndex-th parameter to the 9711 ** xFilter method will be an [sqlite3_value] that appears to be NULL, 9712 ** but which can be passed to [sqlite3_vtab_in_first()] and 9713 ** [sqlite3_vtab_in_next()] to find all values on the right-hand side 9714 ** of the IN constraint. 9715 */ 9716 SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle); 9717 9718 /* 9719 ** CAPI3REF: Find all elements on the right-hand side of an IN constraint. 9720 ** 9721 ** These interfaces are only useful from within the 9722 ** [xFilter|xFilter() method] of a [virtual table] implementation. 9723 ** The result of invoking these interfaces from any other context 9724 ** is undefined and probably harmful. 9725 ** 9726 ** The X parameter in a call to sqlite3_vtab_in_first(X,P) or 9727 ** sqlite3_vtab_in_next(X,P) must be one of the parameters to the 9728 ** xFilter method which invokes these routines, and specifically 9729 ** a parameter that was previously selected for all-at-once IN constraint 9730 ** processing use the [sqlite3_vtab_in()] interface in the 9731 ** [xBestIndex|xBestIndex method]. ^(If the X parameter is not 9732 ** an xFilter argument that was selected for all-at-once IN constraint 9733 ** processing, then these routines return [SQLITE_MISUSE])^ or perhaps 9734 ** exhibit some other undefined or harmful behavior. 9735 ** 9736 ** ^(Use these routines to access all values on the right-hand side 9737 ** of the IN constraint using code like the following: 9738 ** 9739 ** <blockquote><pre> 9740 ** for(rc=sqlite3_vtab_in_first(pList, &pVal); 9741 ** rc==SQLITE_OK && pVal 9742 ** rc=sqlite3_vtab_in_next(pList, &pVal) 9743 ** ){ 9744 ** // do something with pVal 9745 ** } 9746 ** if( rc!=SQLITE_OK ){ 9747 ** // an error has occurred 9748 ** } 9749 ** </pre></blockquote>)^ 9750 ** 9751 ** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P) 9752 ** routines return SQLITE_OK and set *P to point to the first or next value 9753 ** on the RHS of the IN constraint. ^If there are no more values on the 9754 ** right hand side of the IN constraint, then *P is set to NULL and these 9755 ** routines return [SQLITE_DONE]. ^The return value might be 9756 ** some other value, such as SQLITE_NOMEM, in the event of a malfunction. 9757 ** 9758 ** The *ppOut values returned by these routines are only valid until the 9759 ** next call to either of these routines or until the end of the xFilter 9760 ** method from which these routines were called. If the virtual table 9761 ** implementation needs to retain the *ppOut values for longer, it must make 9762 ** copies. The *ppOut values are [protected sqlite3_value|protected]. 9763 */ 9764 SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut); 9765 SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut); 9766 9767 /* 9768 ** CAPI3REF: Constraint values in xBestIndex() 9769 ** METHOD: sqlite3_index_info 9770 ** 9771 ** This API may only be used from within the [xBestIndex|xBestIndex method] 9772 ** of a [virtual table] implementation. The result of calling this interface 9773 ** from outside of an xBestIndex method are undefined and probably harmful. 9774 ** 9775 ** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within 9776 ** the [xBestIndex] method of a [virtual table] implementation, with P being 9777 ** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and 9778 ** J being a 0-based index into P->aConstraint[], then this routine 9779 ** attempts to set *V to the value of the right-hand operand of 9780 ** that constraint if the right-hand operand is known. ^If the 9781 ** right-hand operand is not known, then *V is set to a NULL pointer. 9782 ** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if 9783 ** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V) 9784 ** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th 9785 ** constraint is not available. ^The sqlite3_vtab_rhs_value() interface 9786 ** can return an result code other than SQLITE_OK or SQLITE_NOTFOUND if 9787 ** something goes wrong. 9788 ** 9789 ** The sqlite3_vtab_rhs_value() interface is usually only successful if 9790 ** the right-hand operand of a constraint is a literal value in the original 9791 ** SQL statement. If the right-hand operand is an expression or a reference 9792 ** to some other column or a [host parameter], then sqlite3_vtab_rhs_value() 9793 ** will probably return [SQLITE_NOTFOUND]. 9794 ** 9795 ** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and 9796 ** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such 9797 ** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^ 9798 ** 9799 ** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value 9800 ** and remains valid for the duration of the xBestIndex method call. 9801 ** ^When xBestIndex returns, the sqlite3_value object returned by 9802 ** sqlite3_vtab_rhs_value() is automatically deallocated. 9803 ** 9804 ** The "_rhs_" in the name of this routine is an abbreviation for 9805 ** "Right-Hand Side". 9806 */ 9807 SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal); 9808 9809 /* 9810 ** CAPI3REF: Conflict resolution modes 9811 ** KEYWORDS: {conflict resolution mode} 9812 ** 9813 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 9814 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 9815 ** is for the SQL statement being evaluated. 9816 ** 9817 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 9818 ** return value from the [sqlite3_set_authorizer()] callback and that 9819 ** [SQLITE_ABORT] is also a [result code]. 9820 */ 9821 #define SQLITE_ROLLBACK 1 9822 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 9823 #define SQLITE_FAIL 3 9824 /* #define SQLITE_ABORT 4 // Also an error code */ 9825 #define SQLITE_REPLACE 5 9826 9827 /* 9828 ** CAPI3REF: Prepared Statement Scan Status Opcodes 9829 ** KEYWORDS: {scanstatus options} 9830 ** 9831 ** The following constants can be used for the T parameter to the 9832 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 9833 ** different metric for sqlite3_stmt_scanstatus() to return. 9834 ** 9835 ** When the value returned to V is a string, space to hold that string is 9836 ** managed by the prepared statement S and will be automatically freed when 9837 ** S is finalized. 9838 ** 9839 ** <dl> 9840 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 9841 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 9842 ** set to the total number of times that the X-th loop has run.</dd> 9843 ** 9844 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 9845 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 9846 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 9847 ** 9848 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 9849 ** <dd>^The "double" variable pointed to by the V parameter will be set to the 9850 ** query planner's estimate for the average number of rows output from each 9851 ** iteration of the X-th loop. If the query planner's estimates was accurate, 9852 ** then this value will approximate the quotient NVISIT/NLOOP and the 9853 ** product of this value for all prior loops with the same SELECTID will 9854 ** be the NLOOP value for the current loop. 9855 ** 9856 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 9857 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 9858 ** to a zero-terminated UTF-8 string containing the name of the index or table 9859 ** used for the X-th loop. 9860 ** 9861 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 9862 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 9863 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 9864 ** description for the X-th loop. 9865 ** 9866 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 9867 ** <dd>^The "int" variable pointed to by the V parameter will be set to the 9868 ** "select-id" for the X-th loop. The select-id identifies which query or 9869 ** subquery the loop is part of. The main query has a select-id of zero. 9870 ** The select-id is the same value as is output in the first column 9871 ** of an [EXPLAIN QUERY PLAN] query. 9872 ** </dl> 9873 */ 9874 #define SQLITE_SCANSTAT_NLOOP 0 9875 #define SQLITE_SCANSTAT_NVISIT 1 9876 #define SQLITE_SCANSTAT_EST 2 9877 #define SQLITE_SCANSTAT_NAME 3 9878 #define SQLITE_SCANSTAT_EXPLAIN 4 9879 #define SQLITE_SCANSTAT_SELECTID 5 9880 9881 /* 9882 ** CAPI3REF: Prepared Statement Scan Status 9883 ** METHOD: sqlite3_stmt 9884 ** 9885 ** This interface returns information about the predicted and measured 9886 ** performance for pStmt. Advanced applications can use this 9887 ** interface to compare the predicted and the measured performance and 9888 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 9889 ** 9890 ** Since this interface is expected to be rarely used, it is only 9891 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 9892 ** compile-time option. 9893 ** 9894 ** The "iScanStatusOp" parameter determines which status information to return. 9895 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 9896 ** of this interface is undefined. 9897 ** ^The requested measurement is written into a variable pointed to by 9898 ** the "pOut" parameter. 9899 ** Parameter "idx" identifies the specific loop to retrieve statistics for. 9900 ** Loops are numbered starting from zero. ^If idx is out of range - less than 9901 ** zero or greater than or equal to the total number of loops used to implement 9902 ** the statement - a non-zero value is returned and the variable that pOut 9903 ** points to is unchanged. 9904 ** 9905 ** ^Statistics might not be available for all loops in all statements. ^In cases 9906 ** where there exist loops with no available statistics, this function behaves 9907 ** as if the loop did not exist - it returns non-zero and leave the variable 9908 ** that pOut points to unchanged. 9909 ** 9910 ** See also: [sqlite3_stmt_scanstatus_reset()] 9911 */ 9912 SQLITE_API int sqlite3_stmt_scanstatus( 9913 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 9914 int idx, /* Index of loop to report on */ 9915 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 9916 void *pOut /* Result written here */ 9917 ); 9918 9919 /* 9920 ** CAPI3REF: Zero Scan-Status Counters 9921 ** METHOD: sqlite3_stmt 9922 ** 9923 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 9924 ** 9925 ** This API is only available if the library is built with pre-processor 9926 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 9927 */ 9928 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 9929 9930 /* 9931 ** CAPI3REF: Flush caches to disk mid-transaction 9932 ** METHOD: sqlite3 9933 ** 9934 ** ^If a write-transaction is open on [database connection] D when the 9935 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 9936 ** pages in the pager-cache that are not currently in use are written out 9937 ** to disk. A dirty page may be in use if a database cursor created by an 9938 ** active SQL statement is reading from it, or if it is page 1 of a database 9939 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 9940 ** interface flushes caches for all schemas - "main", "temp", and 9941 ** any [attached] databases. 9942 ** 9943 ** ^If this function needs to obtain extra database locks before dirty pages 9944 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 9945 ** immediately and there is a busy-handler callback configured, it is invoked 9946 ** in the usual manner. ^If the required lock still cannot be obtained, then 9947 ** the database is skipped and an attempt made to flush any dirty pages 9948 ** belonging to the next (if any) database. ^If any databases are skipped 9949 ** because locks cannot be obtained, but no other error occurs, this 9950 ** function returns SQLITE_BUSY. 9951 ** 9952 ** ^If any other error occurs while flushing dirty pages to disk (for 9953 ** example an IO error or out-of-memory condition), then processing is 9954 ** abandoned and an SQLite [error code] is returned to the caller immediately. 9955 ** 9956 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 9957 ** 9958 ** ^This function does not set the database handle error code or message 9959 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 9960 */ 9961 SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 9962 9963 /* 9964 ** CAPI3REF: The pre-update hook. 9965 ** METHOD: sqlite3 9966 ** 9967 ** ^These interfaces are only available if SQLite is compiled using the 9968 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 9969 ** 9970 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 9971 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 9972 ** on a database table. 9973 ** ^At most one preupdate hook may be registered at a time on a single 9974 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 9975 ** the previous setting. 9976 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 9977 ** with a NULL pointer as the second parameter. 9978 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 9979 ** the first parameter to callbacks. 9980 ** 9981 ** ^The preupdate hook only fires for changes to real database tables; the 9982 ** preupdate hook is not invoked for changes to [virtual tables] or to 9983 ** system tables like sqlite_sequence or sqlite_stat1. 9984 ** 9985 ** ^The second parameter to the preupdate callback is a pointer to 9986 ** the [database connection] that registered the preupdate hook. 9987 ** ^The third parameter to the preupdate callback is one of the constants 9988 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 9989 ** kind of update operation that is about to occur. 9990 ** ^(The fourth parameter to the preupdate callback is the name of the 9991 ** database within the database connection that is being modified. This 9992 ** will be "main" for the main database or "temp" for TEMP tables or 9993 ** the name given after the AS keyword in the [ATTACH] statement for attached 9994 ** databases.)^ 9995 ** ^The fifth parameter to the preupdate callback is the name of the 9996 ** table that is being modified. 9997 ** 9998 ** For an UPDATE or DELETE operation on a [rowid table], the sixth 9999 ** parameter passed to the preupdate callback is the initial [rowid] of the 10000 ** row being modified or deleted. For an INSERT operation on a rowid table, 10001 ** or any operation on a WITHOUT ROWID table, the value of the sixth 10002 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the 10003 ** seventh parameter is the final rowid value of the row being inserted 10004 ** or updated. The value of the seventh parameter passed to the callback 10005 ** function is not defined for operations on WITHOUT ROWID tables, or for 10006 ** DELETE operations on rowid tables. 10007 ** 10008 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 10009 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 10010 ** provide additional information about a preupdate event. These routines 10011 ** may only be called from within a preupdate callback. Invoking any of 10012 ** these routines from outside of a preupdate callback or with a 10013 ** [database connection] pointer that is different from the one supplied 10014 ** to the preupdate callback results in undefined and probably undesirable 10015 ** behavior. 10016 ** 10017 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 10018 ** in the row that is being inserted, updated, or deleted. 10019 ** 10020 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 10021 ** a [protected sqlite3_value] that contains the value of the Nth column of 10022 ** the table row before it is updated. The N parameter must be between 0 10023 ** and one less than the number of columns or the behavior will be 10024 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 10025 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 10026 ** behavior is undefined. The [sqlite3_value] that P points to 10027 ** will be destroyed when the preupdate callback returns. 10028 ** 10029 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 10030 ** a [protected sqlite3_value] that contains the value of the Nth column of 10031 ** the table row after it is updated. The N parameter must be between 0 10032 ** and one less than the number of columns or the behavior will be 10033 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 10034 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 10035 ** behavior is undefined. The [sqlite3_value] that P points to 10036 ** will be destroyed when the preupdate callback returns. 10037 ** 10038 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 10039 ** callback was invoked as a result of a direct insert, update, or delete 10040 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 10041 ** triggers; or 2 for changes resulting from triggers called by top-level 10042 ** triggers; and so forth. 10043 ** 10044 ** When the [sqlite3_blob_write()] API is used to update a blob column, 10045 ** the pre-update hook is invoked with SQLITE_DELETE. This is because the 10046 ** in this case the new values are not available. In this case, when a 10047 ** callback made with op==SQLITE_DELETE is actuall a write using the 10048 ** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns 10049 ** the index of the column being written. In other cases, where the 10050 ** pre-update hook is being invoked for some other reason, including a 10051 ** regular DELETE, sqlite3_preupdate_blobwrite() returns -1. 10052 ** 10053 ** See also: [sqlite3_update_hook()] 10054 */ 10055 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 10056 SQLITE_API void *sqlite3_preupdate_hook( 10057 sqlite3 *db, 10058 void(*xPreUpdate)( 10059 void *pCtx, /* Copy of third arg to preupdate_hook() */ 10060 sqlite3 *db, /* Database handle */ 10061 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 10062 char const *zDb, /* Database name */ 10063 char const *zName, /* Table name */ 10064 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 10065 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 10066 ), 10067 void* 10068 ); 10069 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 10070 SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 10071 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 10072 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 10073 SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *); 10074 #endif 10075 10076 /* 10077 ** CAPI3REF: Low-level system error code 10078 ** METHOD: sqlite3 10079 ** 10080 ** ^Attempt to return the underlying operating system error code or error 10081 ** number that caused the most recent I/O error or failure to open a file. 10082 ** The return value is OS-dependent. For example, on unix systems, after 10083 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 10084 ** called to get back the underlying "errno" that caused the problem, such 10085 ** as ENOSPC, EAUTH, EISDIR, and so forth. 10086 */ 10087 SQLITE_API int sqlite3_system_errno(sqlite3*); 10088 10089 /* 10090 ** CAPI3REF: Database Snapshot 10091 ** KEYWORDS: {snapshot} {sqlite3_snapshot} 10092 ** 10093 ** An instance of the snapshot object records the state of a [WAL mode] 10094 ** database for some specific point in history. 10095 ** 10096 ** In [WAL mode], multiple [database connections] that are open on the 10097 ** same database file can each be reading a different historical version 10098 ** of the database file. When a [database connection] begins a read 10099 ** transaction, that connection sees an unchanging copy of the database 10100 ** as it existed for the point in time when the transaction first started. 10101 ** Subsequent changes to the database from other connections are not seen 10102 ** by the reader until a new read transaction is started. 10103 ** 10104 ** The sqlite3_snapshot object records state information about an historical 10105 ** version of the database file so that it is possible to later open a new read 10106 ** transaction that sees that historical version of the database rather than 10107 ** the most recent version. 10108 */ 10109 typedef struct sqlite3_snapshot { 10110 unsigned char hidden[48]; 10111 } sqlite3_snapshot; 10112 10113 /* 10114 ** CAPI3REF: Record A Database Snapshot 10115 ** CONSTRUCTOR: sqlite3_snapshot 10116 ** 10117 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 10118 ** new [sqlite3_snapshot] object that records the current state of 10119 ** schema S in database connection D. ^On success, the 10120 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 10121 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 10122 ** If there is not already a read-transaction open on schema S when 10123 ** this function is called, one is opened automatically. 10124 ** 10125 ** The following must be true for this function to succeed. If any of 10126 ** the following statements are false when sqlite3_snapshot_get() is 10127 ** called, SQLITE_ERROR is returned. The final value of *P is undefined 10128 ** in this case. 10129 ** 10130 ** <ul> 10131 ** <li> The database handle must not be in [autocommit mode]. 10132 ** 10133 ** <li> Schema S of [database connection] D must be a [WAL mode] database. 10134 ** 10135 ** <li> There must not be a write transaction open on schema S of database 10136 ** connection D. 10137 ** 10138 ** <li> One or more transactions must have been written to the current wal 10139 ** file since it was created on disk (by any connection). This means 10140 ** that a snapshot cannot be taken on a wal mode database with no wal 10141 ** file immediately after it is first opened. At least one transaction 10142 ** must be written to it first. 10143 ** </ul> 10144 ** 10145 ** This function may also return SQLITE_NOMEM. If it is called with the 10146 ** database handle in autocommit mode but fails for some other reason, 10147 ** whether or not a read transaction is opened on schema S is undefined. 10148 ** 10149 ** The [sqlite3_snapshot] object returned from a successful call to 10150 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 10151 ** to avoid a memory leak. 10152 ** 10153 ** The [sqlite3_snapshot_get()] interface is only available when the 10154 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10155 */ 10156 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 10157 sqlite3 *db, 10158 const char *zSchema, 10159 sqlite3_snapshot **ppSnapshot 10160 ); 10161 10162 /* 10163 ** CAPI3REF: Start a read transaction on an historical snapshot 10164 ** METHOD: sqlite3_snapshot 10165 ** 10166 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 10167 ** transaction or upgrades an existing one for schema S of 10168 ** [database connection] D such that the read transaction refers to 10169 ** historical [snapshot] P, rather than the most recent change to the 10170 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 10171 ** on success or an appropriate [error code] if it fails. 10172 ** 10173 ** ^In order to succeed, the database connection must not be in 10174 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 10175 ** is already a read transaction open on schema S, then the database handle 10176 ** must have no active statements (SELECT statements that have been passed 10177 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 10178 ** SQLITE_ERROR is returned if either of these conditions is violated, or 10179 ** if schema S does not exist, or if the snapshot object is invalid. 10180 ** 10181 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified 10182 ** snapshot has been overwritten by a [checkpoint]. In this case 10183 ** SQLITE_ERROR_SNAPSHOT is returned. 10184 ** 10185 ** If there is already a read transaction open when this function is 10186 ** invoked, then the same read transaction remains open (on the same 10187 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 10188 ** is returned. If another error code - for example SQLITE_PROTOCOL or an 10189 ** SQLITE_IOERR error code - is returned, then the final state of the 10190 ** read transaction is undefined. If SQLITE_OK is returned, then the 10191 ** read transaction is now open on database snapshot P. 10192 ** 10193 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 10194 ** database connection D does not know that the database file for 10195 ** schema S is in [WAL mode]. A database connection might not know 10196 ** that the database file is in [WAL mode] if there has been no prior 10197 ** I/O on that database connection, or if the database entered [WAL mode] 10198 ** after the most recent I/O on the database connection.)^ 10199 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 10200 ** database connection in order to make it ready to use snapshots.) 10201 ** 10202 ** The [sqlite3_snapshot_open()] interface is only available when the 10203 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10204 */ 10205 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 10206 sqlite3 *db, 10207 const char *zSchema, 10208 sqlite3_snapshot *pSnapshot 10209 ); 10210 10211 /* 10212 ** CAPI3REF: Destroy a snapshot 10213 ** DESTRUCTOR: sqlite3_snapshot 10214 ** 10215 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 10216 ** The application must eventually free every [sqlite3_snapshot] object 10217 ** using this routine to avoid a memory leak. 10218 ** 10219 ** The [sqlite3_snapshot_free()] interface is only available when the 10220 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10221 */ 10222 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 10223 10224 /* 10225 ** CAPI3REF: Compare the ages of two snapshot handles. 10226 ** METHOD: sqlite3_snapshot 10227 ** 10228 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 10229 ** of two valid snapshot handles. 10230 ** 10231 ** If the two snapshot handles are not associated with the same database 10232 ** file, the result of the comparison is undefined. 10233 ** 10234 ** Additionally, the result of the comparison is only valid if both of the 10235 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 10236 ** last time the wal file was deleted. The wal file is deleted when the 10237 ** database is changed back to rollback mode or when the number of database 10238 ** clients drops to zero. If either snapshot handle was obtained before the 10239 ** wal file was last deleted, the value returned by this function 10240 ** is undefined. 10241 ** 10242 ** Otherwise, this API returns a negative value if P1 refers to an older 10243 ** snapshot than P2, zero if the two handles refer to the same database 10244 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 10245 ** 10246 ** This interface is only available if SQLite is compiled with the 10247 ** [SQLITE_ENABLE_SNAPSHOT] option. 10248 */ 10249 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 10250 sqlite3_snapshot *p1, 10251 sqlite3_snapshot *p2 10252 ); 10253 10254 /* 10255 ** CAPI3REF: Recover snapshots from a wal file 10256 ** METHOD: sqlite3_snapshot 10257 ** 10258 ** If a [WAL file] remains on disk after all database connections close 10259 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 10260 ** or because the last process to have the database opened exited without 10261 ** calling [sqlite3_close()]) and a new connection is subsequently opened 10262 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 10263 ** will only be able to open the last transaction added to the WAL file 10264 ** even though the WAL file contains other valid transactions. 10265 ** 10266 ** This function attempts to scan the WAL file associated with database zDb 10267 ** of database handle db and make all valid snapshots available to 10268 ** sqlite3_snapshot_open(). It is an error if there is already a read 10269 ** transaction open on the database, or if the database is not a WAL mode 10270 ** database. 10271 ** 10272 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 10273 ** 10274 ** This interface is only available if SQLite is compiled with the 10275 ** [SQLITE_ENABLE_SNAPSHOT] option. 10276 */ 10277 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 10278 10279 /* 10280 ** CAPI3REF: Serialize a database 10281 ** 10282 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 10283 ** that is a serialization of the S database on [database connection] D. 10284 ** If P is not a NULL pointer, then the size of the database in bytes 10285 ** is written into *P. 10286 ** 10287 ** For an ordinary on-disk database file, the serialization is just a 10288 ** copy of the disk file. For an in-memory database or a "TEMP" database, 10289 ** the serialization is the same sequence of bytes which would be written 10290 ** to disk if that database where backed up to disk. 10291 ** 10292 ** The usual case is that sqlite3_serialize() copies the serialization of 10293 ** the database into memory obtained from [sqlite3_malloc64()] and returns 10294 ** a pointer to that memory. The caller is responsible for freeing the 10295 ** returned value to avoid a memory leak. However, if the F argument 10296 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 10297 ** are made, and the sqlite3_serialize() function will return a pointer 10298 ** to the contiguous memory representation of the database that SQLite 10299 ** is currently using for that database, or NULL if the no such contiguous 10300 ** memory representation of the database exists. A contiguous memory 10301 ** representation of the database will usually only exist if there has 10302 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 10303 ** values of D and S. 10304 ** The size of the database is written into *P even if the 10305 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 10306 ** of the database exists. 10307 ** 10308 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 10309 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 10310 ** allocation error occurs. 10311 ** 10312 ** This interface is omitted if SQLite is compiled with the 10313 ** [SQLITE_OMIT_DESERIALIZE] option. 10314 */ 10315 SQLITE_API unsigned char *sqlite3_serialize( 10316 sqlite3 *db, /* The database connection */ 10317 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 10318 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 10319 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 10320 ); 10321 10322 /* 10323 ** CAPI3REF: Flags for sqlite3_serialize 10324 ** 10325 ** Zero or more of the following constants can be OR-ed together for 10326 ** the F argument to [sqlite3_serialize(D,S,P,F)]. 10327 ** 10328 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 10329 ** a pointer to contiguous in-memory database that it is currently using, 10330 ** without making a copy of the database. If SQLite is not currently using 10331 ** a contiguous in-memory database, then this option causes 10332 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 10333 ** using a contiguous in-memory database if it has been initialized by a 10334 ** prior call to [sqlite3_deserialize()]. 10335 */ 10336 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 10337 10338 /* 10339 ** CAPI3REF: Deserialize a database 10340 ** 10341 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 10342 ** [database connection] D to disconnect from database S and then 10343 ** reopen S as an in-memory database based on the serialization contained 10344 ** in P. The serialized database P is N bytes in size. M is the size of 10345 ** the buffer P, which might be larger than N. If M is larger than N, and 10346 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 10347 ** permitted to add content to the in-memory database as long as the total 10348 ** size does not exceed M bytes. 10349 ** 10350 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 10351 ** invoke sqlite3_free() on the serialization buffer when the database 10352 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 10353 ** SQLite will try to increase the buffer size using sqlite3_realloc64() 10354 ** if writes on the database cause it to grow larger than M bytes. 10355 ** 10356 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 10357 ** database is currently in a read transaction or is involved in a backup 10358 ** operation. 10359 ** 10360 ** It is not possible to deserialized into the TEMP database. If the 10361 ** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the 10362 ** function returns SQLITE_ERROR. 10363 ** 10364 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 10365 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 10366 ** [sqlite3_free()] is invoked on argument P prior to returning. 10367 ** 10368 ** This interface is omitted if SQLite is compiled with the 10369 ** [SQLITE_OMIT_DESERIALIZE] option. 10370 */ 10371 SQLITE_API int sqlite3_deserialize( 10372 sqlite3 *db, /* The database connection */ 10373 const char *zSchema, /* Which DB to reopen with the deserialization */ 10374 unsigned char *pData, /* The serialized database content */ 10375 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 10376 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 10377 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 10378 ); 10379 10380 /* 10381 ** CAPI3REF: Flags for sqlite3_deserialize() 10382 ** 10383 ** The following are allowed values for 6th argument (the F argument) to 10384 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 10385 ** 10386 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 10387 ** in the P argument is held in memory obtained from [sqlite3_malloc64()] 10388 ** and that SQLite should take ownership of this memory and automatically 10389 ** free it when it has finished using it. Without this flag, the caller 10390 ** is responsible for freeing any dynamically allocated memory. 10391 ** 10392 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 10393 ** grow the size of the database using calls to [sqlite3_realloc64()]. This 10394 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 10395 ** Without this flag, the deserialized database cannot increase in size beyond 10396 ** the number of bytes specified by the M parameter. 10397 ** 10398 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 10399 ** should be treated as read-only. 10400 */ 10401 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 10402 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 10403 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 10404 10405 /* 10406 ** Undo the hack that converts floating point types to integer for 10407 ** builds on processors without floating point support. 10408 */ 10409 #ifdef SQLITE_OMIT_FLOATING_POINT 10410 # undef double 10411 #endif 10412 10413 #ifdef __cplusplus 10414 } /* End of the 'extern "C"' block */ 10415 #endif 10416 #endif /* SQLITE3_H */ 10417 10418 /******** Begin file sqlite3rtree.h *********/ 10419 /* 10420 ** 2010 August 30 10421 ** 10422 ** The author disclaims copyright to this source code. In place of 10423 ** a legal notice, here is a blessing: 10424 ** 10425 ** May you do good and not evil. 10426 ** May you find forgiveness for yourself and forgive others. 10427 ** May you share freely, never taking more than you give. 10428 ** 10429 ************************************************************************* 10430 */ 10431 10432 #ifndef _SQLITE3RTREE_H_ 10433 #define _SQLITE3RTREE_H_ 10434 10435 10436 #ifdef __cplusplus 10437 extern "C" { 10438 #endif 10439 10440 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 10441 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 10442 10443 /* The double-precision datatype used by RTree depends on the 10444 ** SQLITE_RTREE_INT_ONLY compile-time option. 10445 */ 10446 #ifdef SQLITE_RTREE_INT_ONLY 10447 typedef sqlite3_int64 sqlite3_rtree_dbl; 10448 #else 10449 typedef double sqlite3_rtree_dbl; 10450 #endif 10451 10452 /* 10453 ** Register a geometry callback named zGeom that can be used as part of an 10454 ** R-Tree geometry query as follows: 10455 ** 10456 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 10457 */ 10458 SQLITE_API int sqlite3_rtree_geometry_callback( 10459 sqlite3 *db, 10460 const char *zGeom, 10461 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 10462 void *pContext 10463 ); 10464 10465 10466 /* 10467 ** A pointer to a structure of the following type is passed as the first 10468 ** argument to callbacks registered using rtree_geometry_callback(). 10469 */ 10470 struct sqlite3_rtree_geometry { 10471 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 10472 int nParam; /* Size of array aParam[] */ 10473 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 10474 void *pUser; /* Callback implementation user data */ 10475 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 10476 }; 10477 10478 /* 10479 ** Register a 2nd-generation geometry callback named zScore that can be 10480 ** used as part of an R-Tree geometry query as follows: 10481 ** 10482 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 10483 */ 10484 SQLITE_API int sqlite3_rtree_query_callback( 10485 sqlite3 *db, 10486 const char *zQueryFunc, 10487 int (*xQueryFunc)(sqlite3_rtree_query_info*), 10488 void *pContext, 10489 void (*xDestructor)(void*) 10490 ); 10491 10492 10493 /* 10494 ** A pointer to a structure of the following type is passed as the 10495 ** argument to scored geometry callback registered using 10496 ** sqlite3_rtree_query_callback(). 10497 ** 10498 ** Note that the first 5 fields of this structure are identical to 10499 ** sqlite3_rtree_geometry. This structure is a subclass of 10500 ** sqlite3_rtree_geometry. 10501 */ 10502 struct sqlite3_rtree_query_info { 10503 void *pContext; /* pContext from when function registered */ 10504 int nParam; /* Number of function parameters */ 10505 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 10506 void *pUser; /* callback can use this, if desired */ 10507 void (*xDelUser)(void*); /* function to free pUser */ 10508 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 10509 unsigned int *anQueue; /* Number of pending entries in the queue */ 10510 int nCoord; /* Number of coordinates */ 10511 int iLevel; /* Level of current node or entry */ 10512 int mxLevel; /* The largest iLevel value in the tree */ 10513 sqlite3_int64 iRowid; /* Rowid for current entry */ 10514 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 10515 int eParentWithin; /* Visibility of parent node */ 10516 int eWithin; /* OUT: Visibility */ 10517 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 10518 /* The following fields are only available in 3.8.11 and later */ 10519 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 10520 }; 10521 10522 /* 10523 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 10524 */ 10525 #define NOT_WITHIN 0 /* Object completely outside of query region */ 10526 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 10527 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 10528 10529 10530 #ifdef __cplusplus 10531 } /* end of the 'extern "C"' block */ 10532 #endif 10533 10534 #endif /* ifndef _SQLITE3RTREE_H_ */ 10535 10536 /******** End of sqlite3rtree.h *********/ 10537 /******** Begin file sqlite3session.h *********/ 10538 10539 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 10540 #define __SQLITESESSION_H_ 1 10541 10542 /* 10543 ** Make sure we can call this stuff from C++. 10544 */ 10545 #ifdef __cplusplus 10546 extern "C" { 10547 #endif 10548 10549 10550 /* 10551 ** CAPI3REF: Session Object Handle 10552 ** 10553 ** An instance of this object is a [session] that can be used to 10554 ** record changes to a database. 10555 */ 10556 typedef struct sqlite3_session sqlite3_session; 10557 10558 /* 10559 ** CAPI3REF: Changeset Iterator Handle 10560 ** 10561 ** An instance of this object acts as a cursor for iterating 10562 ** over the elements of a [changeset] or [patchset]. 10563 */ 10564 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 10565 10566 /* 10567 ** CAPI3REF: Create A New Session Object 10568 ** CONSTRUCTOR: sqlite3_session 10569 ** 10570 ** Create a new session object attached to database handle db. If successful, 10571 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 10572 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 10573 ** error code (e.g. SQLITE_NOMEM) is returned. 10574 ** 10575 ** It is possible to create multiple session objects attached to a single 10576 ** database handle. 10577 ** 10578 ** Session objects created using this function should be deleted using the 10579 ** [sqlite3session_delete()] function before the database handle that they 10580 ** are attached to is itself closed. If the database handle is closed before 10581 ** the session object is deleted, then the results of calling any session 10582 ** module function, including [sqlite3session_delete()] on the session object 10583 ** are undefined. 10584 ** 10585 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 10586 ** is not possible for an application to register a pre-update hook on a 10587 ** database handle that has one or more session objects attached. Nor is 10588 ** it possible to create a session object attached to a database handle for 10589 ** which a pre-update hook is already defined. The results of attempting 10590 ** either of these things are undefined. 10591 ** 10592 ** The session object will be used to create changesets for tables in 10593 ** database zDb, where zDb is either "main", or "temp", or the name of an 10594 ** attached database. It is not an error if database zDb is not attached 10595 ** to the database when the session object is created. 10596 */ 10597 SQLITE_API int sqlite3session_create( 10598 sqlite3 *db, /* Database handle */ 10599 const char *zDb, /* Name of db (e.g. "main") */ 10600 sqlite3_session **ppSession /* OUT: New session object */ 10601 ); 10602 10603 /* 10604 ** CAPI3REF: Delete A Session Object 10605 ** DESTRUCTOR: sqlite3_session 10606 ** 10607 ** Delete a session object previously allocated using 10608 ** [sqlite3session_create()]. Once a session object has been deleted, the 10609 ** results of attempting to use pSession with any other session module 10610 ** function are undefined. 10611 ** 10612 ** Session objects must be deleted before the database handle to which they 10613 ** are attached is closed. Refer to the documentation for 10614 ** [sqlite3session_create()] for details. 10615 */ 10616 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 10617 10618 /* 10619 ** CAPIREF: Conigure a Session Object 10620 ** METHOD: sqlite3_session 10621 ** 10622 ** This method is used to configure a session object after it has been 10623 ** created. At present the only valid value for the second parameter is 10624 ** [SQLITE_SESSION_OBJCONFIG_SIZE]. 10625 ** 10626 ** Arguments for sqlite3session_object_config() 10627 ** 10628 ** The following values may passed as the the 4th parameter to 10629 ** sqlite3session_object_config(). 10630 ** 10631 ** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd> 10632 ** This option is used to set, clear or query the flag that enables 10633 ** the [sqlite3session_changeset_size()] API. Because it imposes some 10634 ** computational overhead, this API is disabled by default. Argument 10635 ** pArg must point to a value of type (int). If the value is initially 10636 ** 0, then the sqlite3session_changeset_size() API is disabled. If it 10637 ** is greater than 0, then the same API is enabled. Or, if the initial 10638 ** value is less than zero, no change is made. In all cases the (int) 10639 ** variable is set to 1 if the sqlite3session_changeset_size() API is 10640 ** enabled following the current call, or 0 otherwise. 10641 ** 10642 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after 10643 ** the first table has been attached to the session object. 10644 */ 10645 SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg); 10646 10647 /* 10648 */ 10649 #define SQLITE_SESSION_OBJCONFIG_SIZE 1 10650 10651 /* 10652 ** CAPI3REF: Enable Or Disable A Session Object 10653 ** METHOD: sqlite3_session 10654 ** 10655 ** Enable or disable the recording of changes by a session object. When 10656 ** enabled, a session object records changes made to the database. When 10657 ** disabled - it does not. A newly created session object is enabled. 10658 ** Refer to the documentation for [sqlite3session_changeset()] for further 10659 ** details regarding how enabling and disabling a session object affects 10660 ** the eventual changesets. 10661 ** 10662 ** Passing zero to this function disables the session. Passing a value 10663 ** greater than zero enables it. Passing a value less than zero is a 10664 ** no-op, and may be used to query the current state of the session. 10665 ** 10666 ** The return value indicates the final state of the session object: 0 if 10667 ** the session is disabled, or 1 if it is enabled. 10668 */ 10669 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 10670 10671 /* 10672 ** CAPI3REF: Set Or Clear the Indirect Change Flag 10673 ** METHOD: sqlite3_session 10674 ** 10675 ** Each change recorded by a session object is marked as either direct or 10676 ** indirect. A change is marked as indirect if either: 10677 ** 10678 ** <ul> 10679 ** <li> The session object "indirect" flag is set when the change is 10680 ** made, or 10681 ** <li> The change is made by an SQL trigger or foreign key action 10682 ** instead of directly as a result of a users SQL statement. 10683 ** </ul> 10684 ** 10685 ** If a single row is affected by more than one operation within a session, 10686 ** then the change is considered indirect if all operations meet the criteria 10687 ** for an indirect change above, or direct otherwise. 10688 ** 10689 ** This function is used to set, clear or query the session object indirect 10690 ** flag. If the second argument passed to this function is zero, then the 10691 ** indirect flag is cleared. If it is greater than zero, the indirect flag 10692 ** is set. Passing a value less than zero does not modify the current value 10693 ** of the indirect flag, and may be used to query the current state of the 10694 ** indirect flag for the specified session object. 10695 ** 10696 ** The return value indicates the final state of the indirect flag: 0 if 10697 ** it is clear, or 1 if it is set. 10698 */ 10699 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 10700 10701 /* 10702 ** CAPI3REF: Attach A Table To A Session Object 10703 ** METHOD: sqlite3_session 10704 ** 10705 ** If argument zTab is not NULL, then it is the name of a table to attach 10706 ** to the session object passed as the first argument. All subsequent changes 10707 ** made to the table while the session object is enabled will be recorded. See 10708 ** documentation for [sqlite3session_changeset()] for further details. 10709 ** 10710 ** Or, if argument zTab is NULL, then changes are recorded for all tables 10711 ** in the database. If additional tables are added to the database (by 10712 ** executing "CREATE TABLE" statements) after this call is made, changes for 10713 ** the new tables are also recorded. 10714 ** 10715 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 10716 ** defined as part of their CREATE TABLE statement. It does not matter if the 10717 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 10718 ** KEY may consist of a single column, or may be a composite key. 10719 ** 10720 ** It is not an error if the named table does not exist in the database. Nor 10721 ** is it an error if the named table does not have a PRIMARY KEY. However, 10722 ** no changes will be recorded in either of these scenarios. 10723 ** 10724 ** Changes are not recorded for individual rows that have NULL values stored 10725 ** in one or more of their PRIMARY KEY columns. 10726 ** 10727 ** SQLITE_OK is returned if the call completes without error. Or, if an error 10728 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 10729 ** 10730 ** <h3>Special sqlite_stat1 Handling</h3> 10731 ** 10732 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 10733 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 10734 ** <pre> 10735 ** CREATE TABLE sqlite_stat1(tbl,idx,stat) 10736 ** </pre> 10737 ** 10738 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 10739 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 10740 ** are recorded for rows for which (idx IS NULL) is true. However, for such 10741 ** rows a zero-length blob (SQL value X'') is stored in the changeset or 10742 ** patchset instead of a NULL value. This allows such changesets to be 10743 ** manipulated by legacy implementations of sqlite3changeset_invert(), 10744 ** concat() and similar. 10745 ** 10746 ** The sqlite3changeset_apply() function automatically converts the 10747 ** zero-length blob back to a NULL value when updating the sqlite_stat1 10748 ** table. However, if the application calls sqlite3changeset_new(), 10749 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 10750 ** iterator directly (including on a changeset iterator passed to a 10751 ** conflict-handler callback) then the X'' value is returned. The application 10752 ** must translate X'' to NULL itself if required. 10753 ** 10754 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture 10755 ** changes made to the sqlite_stat1 table. Legacy versions of the 10756 ** sqlite3changeset_apply() function silently ignore any modifications to the 10757 ** sqlite_stat1 table that are part of a changeset or patchset. 10758 */ 10759 SQLITE_API int sqlite3session_attach( 10760 sqlite3_session *pSession, /* Session object */ 10761 const char *zTab /* Table name */ 10762 ); 10763 10764 /* 10765 ** CAPI3REF: Set a table filter on a Session Object. 10766 ** METHOD: sqlite3_session 10767 ** 10768 ** The second argument (xFilter) is the "filter callback". For changes to rows 10769 ** in tables that are not attached to the Session object, the filter is called 10770 ** to determine whether changes to the table's rows should be tracked or not. 10771 ** If xFilter returns 0, changes are not tracked. Note that once a table is 10772 ** attached, xFilter will not be called again. 10773 */ 10774 SQLITE_API void sqlite3session_table_filter( 10775 sqlite3_session *pSession, /* Session object */ 10776 int(*xFilter)( 10777 void *pCtx, /* Copy of third arg to _filter_table() */ 10778 const char *zTab /* Table name */ 10779 ), 10780 void *pCtx /* First argument passed to xFilter */ 10781 ); 10782 10783 /* 10784 ** CAPI3REF: Generate A Changeset From A Session Object 10785 ** METHOD: sqlite3_session 10786 ** 10787 ** Obtain a changeset containing changes to the tables attached to the 10788 ** session object passed as the first argument. If successful, 10789 ** set *ppChangeset to point to a buffer containing the changeset 10790 ** and *pnChangeset to the size of the changeset in bytes before returning 10791 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 10792 ** zero and return an SQLite error code. 10793 ** 10794 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 10795 ** each representing a change to a single row of an attached table. An INSERT 10796 ** change contains the values of each field of a new database row. A DELETE 10797 ** contains the original values of each field of a deleted database row. An 10798 ** UPDATE change contains the original values of each field of an updated 10799 ** database row along with the updated values for each updated non-primary-key 10800 ** column. It is not possible for an UPDATE change to represent a change that 10801 ** modifies the values of primary key columns. If such a change is made, it 10802 ** is represented in a changeset as a DELETE followed by an INSERT. 10803 ** 10804 ** Changes are not recorded for rows that have NULL values stored in one or 10805 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 10806 ** no corresponding change is present in the changesets returned by this 10807 ** function. If an existing row with one or more NULL values stored in 10808 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 10809 ** only an INSERT is appears in the changeset. Similarly, if an existing row 10810 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 10811 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 10812 ** DELETE change only. 10813 ** 10814 ** The contents of a changeset may be traversed using an iterator created 10815 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 10816 ** a database with a compatible schema using the [sqlite3changeset_apply()] 10817 ** API. 10818 ** 10819 ** Within a changeset generated by this function, all changes related to a 10820 ** single table are grouped together. In other words, when iterating through 10821 ** a changeset or when applying a changeset to a database, all changes related 10822 ** to a single table are processed before moving on to the next table. Tables 10823 ** are sorted in the same order in which they were attached (or auto-attached) 10824 ** to the sqlite3_session object. The order in which the changes related to 10825 ** a single table are stored is undefined. 10826 ** 10827 ** Following a successful call to this function, it is the responsibility of 10828 ** the caller to eventually free the buffer that *ppChangeset points to using 10829 ** [sqlite3_free()]. 10830 ** 10831 ** <h3>Changeset Generation</h3> 10832 ** 10833 ** Once a table has been attached to a session object, the session object 10834 ** records the primary key values of all new rows inserted into the table. 10835 ** It also records the original primary key and other column values of any 10836 ** deleted or updated rows. For each unique primary key value, data is only 10837 ** recorded once - the first time a row with said primary key is inserted, 10838 ** updated or deleted in the lifetime of the session. 10839 ** 10840 ** There is one exception to the previous paragraph: when a row is inserted, 10841 ** updated or deleted, if one or more of its primary key columns contain a 10842 ** NULL value, no record of the change is made. 10843 ** 10844 ** The session object therefore accumulates two types of records - those 10845 ** that consist of primary key values only (created when the user inserts 10846 ** a new record) and those that consist of the primary key values and the 10847 ** original values of other table columns (created when the users deletes 10848 ** or updates a record). 10849 ** 10850 ** When this function is called, the requested changeset is created using 10851 ** both the accumulated records and the current contents of the database 10852 ** file. Specifically: 10853 ** 10854 ** <ul> 10855 ** <li> For each record generated by an insert, the database is queried 10856 ** for a row with a matching primary key. If one is found, an INSERT 10857 ** change is added to the changeset. If no such row is found, no change 10858 ** is added to the changeset. 10859 ** 10860 ** <li> For each record generated by an update or delete, the database is 10861 ** queried for a row with a matching primary key. If such a row is 10862 ** found and one or more of the non-primary key fields have been 10863 ** modified from their original values, an UPDATE change is added to 10864 ** the changeset. Or, if no such row is found in the table, a DELETE 10865 ** change is added to the changeset. If there is a row with a matching 10866 ** primary key in the database, but all fields contain their original 10867 ** values, no change is added to the changeset. 10868 ** </ul> 10869 ** 10870 ** This means, amongst other things, that if a row is inserted and then later 10871 ** deleted while a session object is active, neither the insert nor the delete 10872 ** will be present in the changeset. Or if a row is deleted and then later a 10873 ** row with the same primary key values inserted while a session object is 10874 ** active, the resulting changeset will contain an UPDATE change instead of 10875 ** a DELETE and an INSERT. 10876 ** 10877 ** When a session object is disabled (see the [sqlite3session_enable()] API), 10878 ** it does not accumulate records when rows are inserted, updated or deleted. 10879 ** This may appear to have some counter-intuitive effects if a single row 10880 ** is written to more than once during a session. For example, if a row 10881 ** is inserted while a session object is enabled, then later deleted while 10882 ** the same session object is disabled, no INSERT record will appear in the 10883 ** changeset, even though the delete took place while the session was disabled. 10884 ** Or, if one field of a row is updated while a session is disabled, and 10885 ** another field of the same row is updated while the session is enabled, the 10886 ** resulting changeset will contain an UPDATE change that updates both fields. 10887 */ 10888 SQLITE_API int sqlite3session_changeset( 10889 sqlite3_session *pSession, /* Session object */ 10890 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 10891 void **ppChangeset /* OUT: Buffer containing changeset */ 10892 ); 10893 10894 /* 10895 ** CAPI3REF: Return An Upper-limit For The Size Of The Changeset 10896 ** METHOD: sqlite3_session 10897 ** 10898 ** By default, this function always returns 0. For it to return 10899 ** a useful result, the sqlite3_session object must have been configured 10900 ** to enable this API using sqlite3session_object_config() with the 10901 ** SQLITE_SESSION_OBJCONFIG_SIZE verb. 10902 ** 10903 ** When enabled, this function returns an upper limit, in bytes, for the size 10904 ** of the changeset that might be produced if sqlite3session_changeset() were 10905 ** called. The final changeset size might be equal to or smaller than the 10906 ** size in bytes returned by this function. 10907 */ 10908 SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession); 10909 10910 /* 10911 ** CAPI3REF: Load The Difference Between Tables Into A Session 10912 ** METHOD: sqlite3_session 10913 ** 10914 ** If it is not already attached to the session object passed as the first 10915 ** argument, this function attaches table zTbl in the same manner as the 10916 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 10917 ** does not have a primary key, this function is a no-op (but does not return 10918 ** an error). 10919 ** 10920 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 10921 ** attached to the same database handle as the session object that contains 10922 ** a table compatible with the table attached to the session by this function. 10923 ** A table is considered compatible if it: 10924 ** 10925 ** <ul> 10926 ** <li> Has the same name, 10927 ** <li> Has the same set of columns declared in the same order, and 10928 ** <li> Has the same PRIMARY KEY definition. 10929 ** </ul> 10930 ** 10931 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 10932 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 10933 ** but no changes are added to the session object. As with other session 10934 ** APIs, tables without PRIMARY KEYs are simply ignored. 10935 ** 10936 ** This function adds a set of changes to the session object that could be 10937 ** used to update the table in database zFrom (call this the "from-table") 10938 ** so that its content is the same as the table attached to the session 10939 ** object (call this the "to-table"). Specifically: 10940 ** 10941 ** <ul> 10942 ** <li> For each row (primary key) that exists in the to-table but not in 10943 ** the from-table, an INSERT record is added to the session object. 10944 ** 10945 ** <li> For each row (primary key) that exists in the to-table but not in 10946 ** the from-table, a DELETE record is added to the session object. 10947 ** 10948 ** <li> For each row (primary key) that exists in both tables, but features 10949 ** different non-PK values in each, an UPDATE record is added to the 10950 ** session. 10951 ** </ul> 10952 ** 10953 ** To clarify, if this function is called and then a changeset constructed 10954 ** using [sqlite3session_changeset()], then after applying that changeset to 10955 ** database zFrom the contents of the two compatible tables would be 10956 ** identical. 10957 ** 10958 ** It an error if database zFrom does not exist or does not contain the 10959 ** required compatible table. 10960 ** 10961 ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite 10962 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 10963 ** may be set to point to a buffer containing an English language error 10964 ** message. It is the responsibility of the caller to free this buffer using 10965 ** sqlite3_free(). 10966 */ 10967 SQLITE_API int sqlite3session_diff( 10968 sqlite3_session *pSession, 10969 const char *zFromDb, 10970 const char *zTbl, 10971 char **pzErrMsg 10972 ); 10973 10974 10975 /* 10976 ** CAPI3REF: Generate A Patchset From A Session Object 10977 ** METHOD: sqlite3_session 10978 ** 10979 ** The differences between a patchset and a changeset are that: 10980 ** 10981 ** <ul> 10982 ** <li> DELETE records consist of the primary key fields only. The 10983 ** original values of other fields are omitted. 10984 ** <li> The original values of any modified fields are omitted from 10985 ** UPDATE records. 10986 ** </ul> 10987 ** 10988 ** A patchset blob may be used with up to date versions of all 10989 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 10990 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 10991 ** attempting to use a patchset blob with old versions of the 10992 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 10993 ** 10994 ** Because the non-primary key "old.*" fields are omitted, no 10995 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 10996 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 10997 ** in the same way as for changesets. 10998 ** 10999 ** Changes within a patchset are ordered in the same way as for changesets 11000 ** generated by the sqlite3session_changeset() function (i.e. all changes for 11001 ** a single table are grouped together, tables appear in the order in which 11002 ** they were attached to the session object). 11003 */ 11004 SQLITE_API int sqlite3session_patchset( 11005 sqlite3_session *pSession, /* Session object */ 11006 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 11007 void **ppPatchset /* OUT: Buffer containing patchset */ 11008 ); 11009 11010 /* 11011 ** CAPI3REF: Test if a changeset has recorded any changes. 11012 ** 11013 ** Return non-zero if no changes to attached tables have been recorded by 11014 ** the session object passed as the first argument. Otherwise, if one or 11015 ** more changes have been recorded, return zero. 11016 ** 11017 ** Even if this function returns zero, it is possible that calling 11018 ** [sqlite3session_changeset()] on the session handle may still return a 11019 ** changeset that contains no changes. This can happen when a row in 11020 ** an attached table is modified and then later on the original values 11021 ** are restored. However, if this function returns non-zero, then it is 11022 ** guaranteed that a call to sqlite3session_changeset() will return a 11023 ** changeset containing zero changes. 11024 */ 11025 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 11026 11027 /* 11028 ** CAPI3REF: Query for the amount of heap memory used by a session object. 11029 ** 11030 ** This API returns the total amount of heap memory in bytes currently 11031 ** used by the session object passed as the only argument. 11032 */ 11033 SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession); 11034 11035 /* 11036 ** CAPI3REF: Create An Iterator To Traverse A Changeset 11037 ** CONSTRUCTOR: sqlite3_changeset_iter 11038 ** 11039 ** Create an iterator used to iterate through the contents of a changeset. 11040 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 11041 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 11042 ** SQLite error code is returned. 11043 ** 11044 ** The following functions can be used to advance and query a changeset 11045 ** iterator created by this function: 11046 ** 11047 ** <ul> 11048 ** <li> [sqlite3changeset_next()] 11049 ** <li> [sqlite3changeset_op()] 11050 ** <li> [sqlite3changeset_new()] 11051 ** <li> [sqlite3changeset_old()] 11052 ** </ul> 11053 ** 11054 ** It is the responsibility of the caller to eventually destroy the iterator 11055 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 11056 ** changeset (pChangeset) must remain valid until after the iterator is 11057 ** destroyed. 11058 ** 11059 ** Assuming the changeset blob was created by one of the 11060 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 11061 ** [sqlite3changeset_invert()] functions, all changes within the changeset 11062 ** that apply to a single table are grouped together. This means that when 11063 ** an application iterates through a changeset using an iterator created by 11064 ** this function, all changes that relate to a single table are visited 11065 ** consecutively. There is no chance that the iterator will visit a change 11066 ** the applies to table X, then one for table Y, and then later on visit 11067 ** another change for table X. 11068 ** 11069 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent 11070 ** may be modified by passing a combination of 11071 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter. 11072 ** 11073 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b> 11074 ** and therefore subject to change. 11075 */ 11076 SQLITE_API int sqlite3changeset_start( 11077 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 11078 int nChangeset, /* Size of changeset blob in bytes */ 11079 void *pChangeset /* Pointer to blob containing changeset */ 11080 ); 11081 SQLITE_API int sqlite3changeset_start_v2( 11082 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 11083 int nChangeset, /* Size of changeset blob in bytes */ 11084 void *pChangeset, /* Pointer to blob containing changeset */ 11085 int flags /* SESSION_CHANGESETSTART_* flags */ 11086 ); 11087 11088 /* 11089 ** CAPI3REF: Flags for sqlite3changeset_start_v2 11090 ** 11091 ** The following flags may passed via the 4th parameter to 11092 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]: 11093 ** 11094 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 11095 ** Invert the changeset while iterating through it. This is equivalent to 11096 ** inverting a changeset using sqlite3changeset_invert() before applying it. 11097 ** It is an error to specify this flag with a patchset. 11098 */ 11099 #define SQLITE_CHANGESETSTART_INVERT 0x0002 11100 11101 11102 /* 11103 ** CAPI3REF: Advance A Changeset Iterator 11104 ** METHOD: sqlite3_changeset_iter 11105 ** 11106 ** This function may only be used with iterators created by the function 11107 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 11108 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 11109 ** is returned and the call has no effect. 11110 ** 11111 ** Immediately after an iterator is created by sqlite3changeset_start(), it 11112 ** does not point to any change in the changeset. Assuming the changeset 11113 ** is not empty, the first call to this function advances the iterator to 11114 ** point to the first change in the changeset. Each subsequent call advances 11115 ** the iterator to point to the next change in the changeset (if any). If 11116 ** no error occurs and the iterator points to a valid change after a call 11117 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 11118 ** Otherwise, if all changes in the changeset have already been visited, 11119 ** SQLITE_DONE is returned. 11120 ** 11121 ** If an error occurs, an SQLite error code is returned. Possible error 11122 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 11123 ** SQLITE_NOMEM. 11124 */ 11125 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 11126 11127 /* 11128 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 11129 ** METHOD: sqlite3_changeset_iter 11130 ** 11131 ** The pIter argument passed to this function may either be an iterator 11132 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11133 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11134 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 11135 ** is not the case, this function returns [SQLITE_MISUSE]. 11136 ** 11137 ** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three 11138 ** outputs are set through these pointers: 11139 ** 11140 ** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], 11141 ** depending on the type of change that the iterator currently points to; 11142 ** 11143 ** *pnCol is set to the number of columns in the table affected by the change; and 11144 ** 11145 ** *pzTab is set to point to a nul-terminated utf-8 encoded string containing 11146 ** the name of the table affected by the current change. The buffer remains 11147 ** valid until either sqlite3changeset_next() is called on the iterator 11148 ** or until the conflict-handler function returns. 11149 ** 11150 ** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change 11151 ** is an indirect change, or false (0) otherwise. See the documentation for 11152 ** [sqlite3session_indirect()] for a description of direct and indirect 11153 ** changes. 11154 ** 11155 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 11156 ** SQLite error code is returned. The values of the output variables may not 11157 ** be trusted in this case. 11158 */ 11159 SQLITE_API int sqlite3changeset_op( 11160 sqlite3_changeset_iter *pIter, /* Iterator object */ 11161 const char **pzTab, /* OUT: Pointer to table name */ 11162 int *pnCol, /* OUT: Number of columns in table */ 11163 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 11164 int *pbIndirect /* OUT: True for an 'indirect' change */ 11165 ); 11166 11167 /* 11168 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 11169 ** METHOD: sqlite3_changeset_iter 11170 ** 11171 ** For each modified table, a changeset includes the following: 11172 ** 11173 ** <ul> 11174 ** <li> The number of columns in the table, and 11175 ** <li> Which of those columns make up the tables PRIMARY KEY. 11176 ** </ul> 11177 ** 11178 ** This function is used to find which columns comprise the PRIMARY KEY of 11179 ** the table modified by the change that iterator pIter currently points to. 11180 ** If successful, *pabPK is set to point to an array of nCol entries, where 11181 ** nCol is the number of columns in the table. Elements of *pabPK are set to 11182 ** 0x01 if the corresponding column is part of the tables primary key, or 11183 ** 0x00 if it is not. 11184 ** 11185 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 11186 ** in the table. 11187 ** 11188 ** If this function is called when the iterator does not point to a valid 11189 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 11190 ** SQLITE_OK is returned and the output variables populated as described 11191 ** above. 11192 */ 11193 SQLITE_API int sqlite3changeset_pk( 11194 sqlite3_changeset_iter *pIter, /* Iterator object */ 11195 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 11196 int *pnCol /* OUT: Number of entries in output array */ 11197 ); 11198 11199 /* 11200 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 11201 ** METHOD: sqlite3_changeset_iter 11202 ** 11203 ** The pIter argument passed to this function may either be an iterator 11204 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11205 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11206 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 11207 ** Furthermore, it may only be called if the type of change that the iterator 11208 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 11209 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 11210 ** 11211 ** Argument iVal must be greater than or equal to 0, and less than the number 11212 ** of columns in the table affected by the current change. Otherwise, 11213 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11214 ** 11215 ** If successful, this function sets *ppValue to point to a protected 11216 ** sqlite3_value object containing the iVal'th value from the vector of 11217 ** original row values stored as part of the UPDATE or DELETE change and 11218 ** returns SQLITE_OK. The name of the function comes from the fact that this 11219 ** is similar to the "old.*" columns available to update or delete triggers. 11220 ** 11221 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11222 ** is returned and *ppValue is set to NULL. 11223 */ 11224 SQLITE_API int sqlite3changeset_old( 11225 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11226 int iVal, /* Column number */ 11227 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 11228 ); 11229 11230 /* 11231 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 11232 ** METHOD: sqlite3_changeset_iter 11233 ** 11234 ** The pIter argument passed to this function may either be an iterator 11235 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11236 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11237 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 11238 ** Furthermore, it may only be called if the type of change that the iterator 11239 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 11240 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 11241 ** 11242 ** Argument iVal must be greater than or equal to 0, and less than the number 11243 ** of columns in the table affected by the current change. Otherwise, 11244 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11245 ** 11246 ** If successful, this function sets *ppValue to point to a protected 11247 ** sqlite3_value object containing the iVal'th value from the vector of 11248 ** new row values stored as part of the UPDATE or INSERT change and 11249 ** returns SQLITE_OK. If the change is an UPDATE and does not include 11250 ** a new value for the requested column, *ppValue is set to NULL and 11251 ** SQLITE_OK returned. The name of the function comes from the fact that 11252 ** this is similar to the "new.*" columns available to update or delete 11253 ** triggers. 11254 ** 11255 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11256 ** is returned and *ppValue is set to NULL. 11257 */ 11258 SQLITE_API int sqlite3changeset_new( 11259 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11260 int iVal, /* Column number */ 11261 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 11262 ); 11263 11264 /* 11265 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 11266 ** METHOD: sqlite3_changeset_iter 11267 ** 11268 ** This function should only be used with iterator objects passed to a 11269 ** conflict-handler callback by [sqlite3changeset_apply()] with either 11270 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 11271 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 11272 ** is set to NULL. 11273 ** 11274 ** Argument iVal must be greater than or equal to 0, and less than the number 11275 ** of columns in the table affected by the current change. Otherwise, 11276 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11277 ** 11278 ** If successful, this function sets *ppValue to point to a protected 11279 ** sqlite3_value object containing the iVal'th value from the 11280 ** "conflicting row" associated with the current conflict-handler callback 11281 ** and returns SQLITE_OK. 11282 ** 11283 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11284 ** is returned and *ppValue is set to NULL. 11285 */ 11286 SQLITE_API int sqlite3changeset_conflict( 11287 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11288 int iVal, /* Column number */ 11289 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 11290 ); 11291 11292 /* 11293 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 11294 ** METHOD: sqlite3_changeset_iter 11295 ** 11296 ** This function may only be called with an iterator passed to an 11297 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 11298 ** it sets the output variable to the total number of known foreign key 11299 ** violations in the destination database and returns SQLITE_OK. 11300 ** 11301 ** In all other cases this function returns SQLITE_MISUSE. 11302 */ 11303 SQLITE_API int sqlite3changeset_fk_conflicts( 11304 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11305 int *pnOut /* OUT: Number of FK violations */ 11306 ); 11307 11308 11309 /* 11310 ** CAPI3REF: Finalize A Changeset Iterator 11311 ** METHOD: sqlite3_changeset_iter 11312 ** 11313 ** This function is used to finalize an iterator allocated with 11314 ** [sqlite3changeset_start()]. 11315 ** 11316 ** This function should only be called on iterators created using the 11317 ** [sqlite3changeset_start()] function. If an application calls this 11318 ** function with an iterator passed to a conflict-handler by 11319 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 11320 ** call has no effect. 11321 ** 11322 ** If an error was encountered within a call to an sqlite3changeset_xxx() 11323 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 11324 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 11325 ** to that error is returned by this function. Otherwise, SQLITE_OK is 11326 ** returned. This is to allow the following pattern (pseudo-code): 11327 ** 11328 ** <pre> 11329 ** sqlite3changeset_start(); 11330 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 11331 ** // Do something with change. 11332 ** } 11333 ** rc = sqlite3changeset_finalize(); 11334 ** if( rc!=SQLITE_OK ){ 11335 ** // An error has occurred 11336 ** } 11337 ** </pre> 11338 */ 11339 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 11340 11341 /* 11342 ** CAPI3REF: Invert A Changeset 11343 ** 11344 ** This function is used to "invert" a changeset object. Applying an inverted 11345 ** changeset to a database reverses the effects of applying the uninverted 11346 ** changeset. Specifically: 11347 ** 11348 ** <ul> 11349 ** <li> Each DELETE change is changed to an INSERT, and 11350 ** <li> Each INSERT change is changed to a DELETE, and 11351 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 11352 ** </ul> 11353 ** 11354 ** This function does not change the order in which changes appear within 11355 ** the changeset. It merely reverses the sense of each individual change. 11356 ** 11357 ** If successful, a pointer to a buffer containing the inverted changeset 11358 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 11359 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 11360 ** zeroed and an SQLite error code returned. 11361 ** 11362 ** It is the responsibility of the caller to eventually call sqlite3_free() 11363 ** on the *ppOut pointer to free the buffer allocation following a successful 11364 ** call to this function. 11365 ** 11366 ** WARNING/TODO: This function currently assumes that the input is a valid 11367 ** changeset. If it is not, the results are undefined. 11368 */ 11369 SQLITE_API int sqlite3changeset_invert( 11370 int nIn, const void *pIn, /* Input changeset */ 11371 int *pnOut, void **ppOut /* OUT: Inverse of input */ 11372 ); 11373 11374 /* 11375 ** CAPI3REF: Concatenate Two Changeset Objects 11376 ** 11377 ** This function is used to concatenate two changesets, A and B, into a 11378 ** single changeset. The result is a changeset equivalent to applying 11379 ** changeset A followed by changeset B. 11380 ** 11381 ** This function combines the two input changesets using an 11382 ** sqlite3_changegroup object. Calling it produces similar results as the 11383 ** following code fragment: 11384 ** 11385 ** <pre> 11386 ** sqlite3_changegroup *pGrp; 11387 ** rc = sqlite3_changegroup_new(&pGrp); 11388 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 11389 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 11390 ** if( rc==SQLITE_OK ){ 11391 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 11392 ** }else{ 11393 ** *ppOut = 0; 11394 ** *pnOut = 0; 11395 ** } 11396 ** </pre> 11397 ** 11398 ** Refer to the sqlite3_changegroup documentation below for details. 11399 */ 11400 SQLITE_API int sqlite3changeset_concat( 11401 int nA, /* Number of bytes in buffer pA */ 11402 void *pA, /* Pointer to buffer containing changeset A */ 11403 int nB, /* Number of bytes in buffer pB */ 11404 void *pB, /* Pointer to buffer containing changeset B */ 11405 int *pnOut, /* OUT: Number of bytes in output changeset */ 11406 void **ppOut /* OUT: Buffer containing output changeset */ 11407 ); 11408 11409 11410 /* 11411 ** CAPI3REF: Changegroup Handle 11412 ** 11413 ** A changegroup is an object used to combine two or more 11414 ** [changesets] or [patchsets] 11415 */ 11416 typedef struct sqlite3_changegroup sqlite3_changegroup; 11417 11418 /* 11419 ** CAPI3REF: Create A New Changegroup Object 11420 ** CONSTRUCTOR: sqlite3_changegroup 11421 ** 11422 ** An sqlite3_changegroup object is used to combine two or more changesets 11423 ** (or patchsets) into a single changeset (or patchset). A single changegroup 11424 ** object may combine changesets or patchsets, but not both. The output is 11425 ** always in the same format as the input. 11426 ** 11427 ** If successful, this function returns SQLITE_OK and populates (*pp) with 11428 ** a pointer to a new sqlite3_changegroup object before returning. The caller 11429 ** should eventually free the returned object using a call to 11430 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 11431 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 11432 ** 11433 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 11434 ** 11435 ** <ul> 11436 ** <li> It is created using a call to sqlite3changegroup_new(). 11437 ** 11438 ** <li> Zero or more changesets (or patchsets) are added to the object 11439 ** by calling sqlite3changegroup_add(). 11440 ** 11441 ** <li> The result of combining all input changesets together is obtained 11442 ** by the application via a call to sqlite3changegroup_output(). 11443 ** 11444 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 11445 ** </ul> 11446 ** 11447 ** Any number of calls to add() and output() may be made between the calls to 11448 ** new() and delete(), and in any order. 11449 ** 11450 ** As well as the regular sqlite3changegroup_add() and 11451 ** sqlite3changegroup_output() functions, also available are the streaming 11452 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 11453 */ 11454 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 11455 11456 /* 11457 ** CAPI3REF: Add A Changeset To A Changegroup 11458 ** METHOD: sqlite3_changegroup 11459 ** 11460 ** Add all changes within the changeset (or patchset) in buffer pData (size 11461 ** nData bytes) to the changegroup. 11462 ** 11463 ** If the buffer contains a patchset, then all prior calls to this function 11464 ** on the same changegroup object must also have specified patchsets. Or, if 11465 ** the buffer contains a changeset, so must have the earlier calls to this 11466 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 11467 ** to the changegroup. 11468 ** 11469 ** Rows within the changeset and changegroup are identified by the values in 11470 ** their PRIMARY KEY columns. A change in the changeset is considered to 11471 ** apply to the same row as a change already present in the changegroup if 11472 ** the two rows have the same primary key. 11473 ** 11474 ** Changes to rows that do not already appear in the changegroup are 11475 ** simply copied into it. Or, if both the new changeset and the changegroup 11476 ** contain changes that apply to a single row, the final contents of the 11477 ** changegroup depends on the type of each change, as follows: 11478 ** 11479 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 11480 ** <tr><th style="white-space:pre">Existing Change </th> 11481 ** <th style="white-space:pre">New Change </th> 11482 ** <th>Output Change 11483 ** <tr><td>INSERT <td>INSERT <td> 11484 ** The new change is ignored. This case does not occur if the new 11485 ** changeset was recorded immediately after the changesets already 11486 ** added to the changegroup. 11487 ** <tr><td>INSERT <td>UPDATE <td> 11488 ** The INSERT change remains in the changegroup. The values in the 11489 ** INSERT change are modified as if the row was inserted by the 11490 ** existing change and then updated according to the new change. 11491 ** <tr><td>INSERT <td>DELETE <td> 11492 ** The existing INSERT is removed from the changegroup. The DELETE is 11493 ** not added. 11494 ** <tr><td>UPDATE <td>INSERT <td> 11495 ** The new change is ignored. This case does not occur if the new 11496 ** changeset was recorded immediately after the changesets already 11497 ** added to the changegroup. 11498 ** <tr><td>UPDATE <td>UPDATE <td> 11499 ** The existing UPDATE remains within the changegroup. It is amended 11500 ** so that the accompanying values are as if the row was updated once 11501 ** by the existing change and then again by the new change. 11502 ** <tr><td>UPDATE <td>DELETE <td> 11503 ** The existing UPDATE is replaced by the new DELETE within the 11504 ** changegroup. 11505 ** <tr><td>DELETE <td>INSERT <td> 11506 ** If one or more of the column values in the row inserted by the 11507 ** new change differ from those in the row deleted by the existing 11508 ** change, the existing DELETE is replaced by an UPDATE within the 11509 ** changegroup. Otherwise, if the inserted row is exactly the same 11510 ** as the deleted row, the existing DELETE is simply discarded. 11511 ** <tr><td>DELETE <td>UPDATE <td> 11512 ** The new change is ignored. This case does not occur if the new 11513 ** changeset was recorded immediately after the changesets already 11514 ** added to the changegroup. 11515 ** <tr><td>DELETE <td>DELETE <td> 11516 ** The new change is ignored. This case does not occur if the new 11517 ** changeset was recorded immediately after the changesets already 11518 ** added to the changegroup. 11519 ** </table> 11520 ** 11521 ** If the new changeset contains changes to a table that is already present 11522 ** in the changegroup, then the number of columns and the position of the 11523 ** primary key columns for the table must be consistent. If this is not the 11524 ** case, this function fails with SQLITE_SCHEMA. If the input changeset 11525 ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 11526 ** returned. Or, if an out-of-memory condition occurs during processing, this 11527 ** function returns SQLITE_NOMEM. In all cases, if an error occurs the state 11528 ** of the final contents of the changegroup is undefined. 11529 ** 11530 ** If no error occurs, SQLITE_OK is returned. 11531 */ 11532 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 11533 11534 /* 11535 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 11536 ** METHOD: sqlite3_changegroup 11537 ** 11538 ** Obtain a buffer containing a changeset (or patchset) representing the 11539 ** current contents of the changegroup. If the inputs to the changegroup 11540 ** were themselves changesets, the output is a changeset. Or, if the 11541 ** inputs were patchsets, the output is also a patchset. 11542 ** 11543 ** As with the output of the sqlite3session_changeset() and 11544 ** sqlite3session_patchset() functions, all changes related to a single 11545 ** table are grouped together in the output of this function. Tables appear 11546 ** in the same order as for the very first changeset added to the changegroup. 11547 ** If the second or subsequent changesets added to the changegroup contain 11548 ** changes for tables that do not appear in the first changeset, they are 11549 ** appended onto the end of the output changeset, again in the order in 11550 ** which they are first encountered. 11551 ** 11552 ** If an error occurs, an SQLite error code is returned and the output 11553 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 11554 ** is returned and the output variables are set to the size of and a 11555 ** pointer to the output buffer, respectively. In this case it is the 11556 ** responsibility of the caller to eventually free the buffer using a 11557 ** call to sqlite3_free(). 11558 */ 11559 SQLITE_API int sqlite3changegroup_output( 11560 sqlite3_changegroup*, 11561 int *pnData, /* OUT: Size of output buffer in bytes */ 11562 void **ppData /* OUT: Pointer to output buffer */ 11563 ); 11564 11565 /* 11566 ** CAPI3REF: Delete A Changegroup Object 11567 ** DESTRUCTOR: sqlite3_changegroup 11568 */ 11569 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 11570 11571 /* 11572 ** CAPI3REF: Apply A Changeset To A Database 11573 ** 11574 ** Apply a changeset or patchset to a database. These functions attempt to 11575 ** update the "main" database attached to handle db with the changes found in 11576 ** the changeset passed via the second and third arguments. 11577 ** 11578 ** The fourth argument (xFilter) passed to these functions is the "filter 11579 ** callback". If it is not NULL, then for each table affected by at least one 11580 ** change in the changeset, the filter callback is invoked with 11581 ** the table name as the second argument, and a copy of the context pointer 11582 ** passed as the sixth argument as the first. If the "filter callback" 11583 ** returns zero, then no attempt is made to apply any changes to the table. 11584 ** Otherwise, if the return value is non-zero or the xFilter argument to 11585 ** is NULL, all changes related to the table are attempted. 11586 ** 11587 ** For each table that is not excluded by the filter callback, this function 11588 ** tests that the target database contains a compatible table. A table is 11589 ** considered compatible if all of the following are true: 11590 ** 11591 ** <ul> 11592 ** <li> The table has the same name as the name recorded in the 11593 ** changeset, and 11594 ** <li> The table has at least as many columns as recorded in the 11595 ** changeset, and 11596 ** <li> The table has primary key columns in the same position as 11597 ** recorded in the changeset. 11598 ** </ul> 11599 ** 11600 ** If there is no compatible table, it is not an error, but none of the 11601 ** changes associated with the table are applied. A warning message is issued 11602 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 11603 ** one such warning is issued for each table in the changeset. 11604 ** 11605 ** For each change for which there is a compatible table, an attempt is made 11606 ** to modify the table contents according to the UPDATE, INSERT or DELETE 11607 ** change. If a change cannot be applied cleanly, the conflict handler 11608 ** function passed as the fifth argument to sqlite3changeset_apply() may be 11609 ** invoked. A description of exactly when the conflict handler is invoked for 11610 ** each type of change is below. 11611 ** 11612 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 11613 ** of passing anything other than a valid function pointer as the xConflict 11614 ** argument are undefined. 11615 ** 11616 ** Each time the conflict handler function is invoked, it must return one 11617 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 11618 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 11619 ** if the second argument passed to the conflict handler is either 11620 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 11621 ** returns an illegal value, any changes already made are rolled back and 11622 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 11623 ** actions are taken by sqlite3changeset_apply() depending on the value 11624 ** returned by each invocation of the conflict-handler function. Refer to 11625 ** the documentation for the three 11626 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 11627 ** 11628 ** <dl> 11629 ** <dt>DELETE Changes<dd> 11630 ** For each DELETE change, the function checks if the target database 11631 ** contains a row with the same primary key value (or values) as the 11632 ** original row values stored in the changeset. If it does, and the values 11633 ** stored in all non-primary key columns also match the values stored in 11634 ** the changeset the row is deleted from the target database. 11635 ** 11636 ** If a row with matching primary key values is found, but one or more of 11637 ** the non-primary key fields contains a value different from the original 11638 ** row value stored in the changeset, the conflict-handler function is 11639 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 11640 ** database table has more columns than are recorded in the changeset, 11641 ** only the values of those non-primary key fields are compared against 11642 ** the current database contents - any trailing database table columns 11643 ** are ignored. 11644 ** 11645 ** If no row with matching primary key values is found in the database, 11646 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 11647 ** passed as the second argument. 11648 ** 11649 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 11650 ** (which can only happen if a foreign key constraint is violated), the 11651 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 11652 ** passed as the second argument. This includes the case where the DELETE 11653 ** operation is attempted because an earlier call to the conflict handler 11654 ** function returned [SQLITE_CHANGESET_REPLACE]. 11655 ** 11656 ** <dt>INSERT Changes<dd> 11657 ** For each INSERT change, an attempt is made to insert the new row into 11658 ** the database. If the changeset row contains fewer fields than the 11659 ** database table, the trailing fields are populated with their default 11660 ** values. 11661 ** 11662 ** If the attempt to insert the row fails because the database already 11663 ** contains a row with the same primary key values, the conflict handler 11664 ** function is invoked with the second argument set to 11665 ** [SQLITE_CHANGESET_CONFLICT]. 11666 ** 11667 ** If the attempt to insert the row fails because of some other constraint 11668 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 11669 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 11670 ** This includes the case where the INSERT operation is re-attempted because 11671 ** an earlier call to the conflict handler function returned 11672 ** [SQLITE_CHANGESET_REPLACE]. 11673 ** 11674 ** <dt>UPDATE Changes<dd> 11675 ** For each UPDATE change, the function checks if the target database 11676 ** contains a row with the same primary key value (or values) as the 11677 ** original row values stored in the changeset. If it does, and the values 11678 ** stored in all modified non-primary key columns also match the values 11679 ** stored in the changeset the row is updated within the target database. 11680 ** 11681 ** If a row with matching primary key values is found, but one or more of 11682 ** the modified non-primary key fields contains a value different from an 11683 ** original row value stored in the changeset, the conflict-handler function 11684 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 11685 ** UPDATE changes only contain values for non-primary key fields that are 11686 ** to be modified, only those fields need to match the original values to 11687 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 11688 ** 11689 ** If no row with matching primary key values is found in the database, 11690 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 11691 ** passed as the second argument. 11692 ** 11693 ** If the UPDATE operation is attempted, but SQLite returns 11694 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 11695 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 11696 ** This includes the case where the UPDATE operation is attempted after 11697 ** an earlier call to the conflict handler function returned 11698 ** [SQLITE_CHANGESET_REPLACE]. 11699 ** </dl> 11700 ** 11701 ** It is safe to execute SQL statements, including those that write to the 11702 ** table that the callback related to, from within the xConflict callback. 11703 ** This can be used to further customize the application's conflict 11704 ** resolution strategy. 11705 ** 11706 ** All changes made by these functions are enclosed in a savepoint transaction. 11707 ** If any other error (aside from a constraint failure when attempting to 11708 ** write to the target database) occurs, then the savepoint transaction is 11709 ** rolled back, restoring the target database to its original state, and an 11710 ** SQLite error code returned. 11711 ** 11712 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 11713 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 11714 ** may set (*ppRebase) to point to a "rebase" that may be used with the 11715 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 11716 ** is set to the size of the buffer in bytes. It is the responsibility of the 11717 ** caller to eventually free any such buffer using sqlite3_free(). The buffer 11718 ** is only allocated and populated if one or more conflicts were encountered 11719 ** while applying the patchset. See comments surrounding the sqlite3_rebaser 11720 ** APIs for further details. 11721 ** 11722 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 11723 ** may be modified by passing a combination of 11724 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 11725 ** 11726 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 11727 ** and therefore subject to change. 11728 */ 11729 SQLITE_API int sqlite3changeset_apply( 11730 sqlite3 *db, /* Apply change to "main" db of this handle */ 11731 int nChangeset, /* Size of changeset in bytes */ 11732 void *pChangeset, /* Changeset blob */ 11733 int(*xFilter)( 11734 void *pCtx, /* Copy of sixth arg to _apply() */ 11735 const char *zTab /* Table name */ 11736 ), 11737 int(*xConflict)( 11738 void *pCtx, /* Copy of sixth arg to _apply() */ 11739 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11740 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11741 ), 11742 void *pCtx /* First argument passed to xConflict */ 11743 ); 11744 SQLITE_API int sqlite3changeset_apply_v2( 11745 sqlite3 *db, /* Apply change to "main" db of this handle */ 11746 int nChangeset, /* Size of changeset in bytes */ 11747 void *pChangeset, /* Changeset blob */ 11748 int(*xFilter)( 11749 void *pCtx, /* Copy of sixth arg to _apply() */ 11750 const char *zTab /* Table name */ 11751 ), 11752 int(*xConflict)( 11753 void *pCtx, /* Copy of sixth arg to _apply() */ 11754 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11755 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11756 ), 11757 void *pCtx, /* First argument passed to xConflict */ 11758 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 11759 int flags /* SESSION_CHANGESETAPPLY_* flags */ 11760 ); 11761 11762 /* 11763 ** CAPI3REF: Flags for sqlite3changeset_apply_v2 11764 ** 11765 ** The following flags may passed via the 9th parameter to 11766 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 11767 ** 11768 ** <dl> 11769 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 11770 ** Usually, the sessions module encloses all operations performed by 11771 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 11772 ** SAVEPOINT is committed if the changeset or patchset is successfully 11773 ** applied, or rolled back if an error occurs. Specifying this flag 11774 ** causes the sessions module to omit this savepoint. In this case, if the 11775 ** caller has an open transaction or savepoint when apply_v2() is called, 11776 ** it may revert the partially applied changeset by rolling it back. 11777 ** 11778 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 11779 ** Invert the changeset before applying it. This is equivalent to inverting 11780 ** a changeset using sqlite3changeset_invert() before applying it. It is 11781 ** an error to specify this flag with a patchset. 11782 */ 11783 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 11784 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002 11785 11786 /* 11787 ** CAPI3REF: Constants Passed To The Conflict Handler 11788 ** 11789 ** Values that may be passed as the second argument to a conflict-handler. 11790 ** 11791 ** <dl> 11792 ** <dt>SQLITE_CHANGESET_DATA<dd> 11793 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 11794 ** when processing a DELETE or UPDATE change if a row with the required 11795 ** PRIMARY KEY fields is present in the database, but one or more other 11796 ** (non primary-key) fields modified by the update do not contain the 11797 ** expected "before" values. 11798 ** 11799 ** The conflicting row, in this case, is the database row with the matching 11800 ** primary key. 11801 ** 11802 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 11803 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 11804 ** argument when processing a DELETE or UPDATE change if a row with the 11805 ** required PRIMARY KEY fields is not present in the database. 11806 ** 11807 ** There is no conflicting row in this case. The results of invoking the 11808 ** sqlite3changeset_conflict() API are undefined. 11809 ** 11810 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 11811 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 11812 ** handler while processing an INSERT change if the operation would result 11813 ** in duplicate primary key values. 11814 ** 11815 ** The conflicting row in this case is the database row with the matching 11816 ** primary key. 11817 ** 11818 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 11819 ** If foreign key handling is enabled, and applying a changeset leaves the 11820 ** database in a state containing foreign key violations, the conflict 11821 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 11822 ** exactly once before the changeset is committed. If the conflict handler 11823 ** returns CHANGESET_OMIT, the changes, including those that caused the 11824 ** foreign key constraint violation, are committed. Or, if it returns 11825 ** CHANGESET_ABORT, the changeset is rolled back. 11826 ** 11827 ** No current or conflicting row information is provided. The only function 11828 ** it is possible to call on the supplied sqlite3_changeset_iter handle 11829 ** is sqlite3changeset_fk_conflicts(). 11830 ** 11831 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 11832 ** If any other constraint violation occurs while applying a change (i.e. 11833 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 11834 ** invoked with CHANGESET_CONSTRAINT as the second argument. 11835 ** 11836 ** There is no conflicting row in this case. The results of invoking the 11837 ** sqlite3changeset_conflict() API are undefined. 11838 ** 11839 ** </dl> 11840 */ 11841 #define SQLITE_CHANGESET_DATA 1 11842 #define SQLITE_CHANGESET_NOTFOUND 2 11843 #define SQLITE_CHANGESET_CONFLICT 3 11844 #define SQLITE_CHANGESET_CONSTRAINT 4 11845 #define SQLITE_CHANGESET_FOREIGN_KEY 5 11846 11847 /* 11848 ** CAPI3REF: Constants Returned By The Conflict Handler 11849 ** 11850 ** A conflict handler callback must return one of the following three values. 11851 ** 11852 ** <dl> 11853 ** <dt>SQLITE_CHANGESET_OMIT<dd> 11854 ** If a conflict handler returns this value no special action is taken. The 11855 ** change that caused the conflict is not applied. The session module 11856 ** continues to the next change in the changeset. 11857 ** 11858 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 11859 ** This value may only be returned if the second argument to the conflict 11860 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 11861 ** is not the case, any changes applied so far are rolled back and the 11862 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 11863 ** 11864 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 11865 ** handler, then the conflicting row is either updated or deleted, depending 11866 ** on the type of change. 11867 ** 11868 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 11869 ** handler, then the conflicting row is removed from the database and a 11870 ** second attempt to apply the change is made. If this second attempt fails, 11871 ** the original row is restored to the database before continuing. 11872 ** 11873 ** <dt>SQLITE_CHANGESET_ABORT<dd> 11874 ** If this value is returned, any changes applied so far are rolled back 11875 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 11876 ** </dl> 11877 */ 11878 #define SQLITE_CHANGESET_OMIT 0 11879 #define SQLITE_CHANGESET_REPLACE 1 11880 #define SQLITE_CHANGESET_ABORT 2 11881 11882 /* 11883 ** CAPI3REF: Rebasing changesets 11884 ** EXPERIMENTAL 11885 ** 11886 ** Suppose there is a site hosting a database in state S0. And that 11887 ** modifications are made that move that database to state S1 and a 11888 ** changeset recorded (the "local" changeset). Then, a changeset based 11889 ** on S0 is received from another site (the "remote" changeset) and 11890 ** applied to the database. The database is then in state 11891 ** (S1+"remote"), where the exact state depends on any conflict 11892 ** resolution decisions (OMIT or REPLACE) made while applying "remote". 11893 ** Rebasing a changeset is to update it to take those conflict 11894 ** resolution decisions into account, so that the same conflicts 11895 ** do not have to be resolved elsewhere in the network. 11896 ** 11897 ** For example, if both the local and remote changesets contain an 11898 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 11899 ** 11900 ** local: INSERT INTO t1 VALUES(1, 'v1'); 11901 ** remote: INSERT INTO t1 VALUES(1, 'v2'); 11902 ** 11903 ** and the conflict resolution is REPLACE, then the INSERT change is 11904 ** removed from the local changeset (it was overridden). Or, if the 11905 ** conflict resolution was "OMIT", then the local changeset is modified 11906 ** to instead contain: 11907 ** 11908 ** UPDATE t1 SET b = 'v2' WHERE a=1; 11909 ** 11910 ** Changes within the local changeset are rebased as follows: 11911 ** 11912 ** <dl> 11913 ** <dt>Local INSERT<dd> 11914 ** This may only conflict with a remote INSERT. If the conflict 11915 ** resolution was OMIT, then add an UPDATE change to the rebased 11916 ** changeset. Or, if the conflict resolution was REPLACE, add 11917 ** nothing to the rebased changeset. 11918 ** 11919 ** <dt>Local DELETE<dd> 11920 ** This may conflict with a remote UPDATE or DELETE. In both cases the 11921 ** only possible resolution is OMIT. If the remote operation was a 11922 ** DELETE, then add no change to the rebased changeset. If the remote 11923 ** operation was an UPDATE, then the old.* fields of change are updated 11924 ** to reflect the new.* values in the UPDATE. 11925 ** 11926 ** <dt>Local UPDATE<dd> 11927 ** This may conflict with a remote UPDATE or DELETE. If it conflicts 11928 ** with a DELETE, and the conflict resolution was OMIT, then the update 11929 ** is changed into an INSERT. Any undefined values in the new.* record 11930 ** from the update change are filled in using the old.* values from 11931 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 11932 ** the UPDATE change is simply omitted from the rebased changeset. 11933 ** 11934 ** If conflict is with a remote UPDATE and the resolution is OMIT, then 11935 ** the old.* values are rebased using the new.* values in the remote 11936 ** change. Or, if the resolution is REPLACE, then the change is copied 11937 ** into the rebased changeset with updates to columns also updated by 11938 ** the conflicting remote UPDATE removed. If this means no columns would 11939 ** be updated, the change is omitted. 11940 ** </dl> 11941 ** 11942 ** A local change may be rebased against multiple remote changes 11943 ** simultaneously. If a single key is modified by multiple remote 11944 ** changesets, they are combined as follows before the local changeset 11945 ** is rebased: 11946 ** 11947 ** <ul> 11948 ** <li> If there has been one or more REPLACE resolutions on a 11949 ** key, it is rebased according to a REPLACE. 11950 ** 11951 ** <li> If there have been no REPLACE resolutions on a key, then 11952 ** the local changeset is rebased according to the most recent 11953 ** of the OMIT resolutions. 11954 ** </ul> 11955 ** 11956 ** Note that conflict resolutions from multiple remote changesets are 11957 ** combined on a per-field basis, not per-row. This means that in the 11958 ** case of multiple remote UPDATE operations, some fields of a single 11959 ** local change may be rebased for REPLACE while others are rebased for 11960 ** OMIT. 11961 ** 11962 ** In order to rebase a local changeset, the remote changeset must first 11963 ** be applied to the local database using sqlite3changeset_apply_v2() and 11964 ** the buffer of rebase information captured. Then: 11965 ** 11966 ** <ol> 11967 ** <li> An sqlite3_rebaser object is created by calling 11968 ** sqlite3rebaser_create(). 11969 ** <li> The new object is configured with the rebase buffer obtained from 11970 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 11971 ** If the local changeset is to be rebased against multiple remote 11972 ** changesets, then sqlite3rebaser_configure() should be called 11973 ** multiple times, in the same order that the multiple 11974 ** sqlite3changeset_apply_v2() calls were made. 11975 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 11976 ** <li> The sqlite3_rebaser object is deleted by calling 11977 ** sqlite3rebaser_delete(). 11978 ** </ol> 11979 */ 11980 typedef struct sqlite3_rebaser sqlite3_rebaser; 11981 11982 /* 11983 ** CAPI3REF: Create a changeset rebaser object. 11984 ** EXPERIMENTAL 11985 ** 11986 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 11987 ** point to the new object and return SQLITE_OK. Otherwise, if an error 11988 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 11989 ** to NULL. 11990 */ 11991 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 11992 11993 /* 11994 ** CAPI3REF: Configure a changeset rebaser object. 11995 ** EXPERIMENTAL 11996 ** 11997 ** Configure the changeset rebaser object to rebase changesets according 11998 ** to the conflict resolutions described by buffer pRebase (size nRebase 11999 ** bytes), which must have been obtained from a previous call to 12000 ** sqlite3changeset_apply_v2(). 12001 */ 12002 SQLITE_API int sqlite3rebaser_configure( 12003 sqlite3_rebaser*, 12004 int nRebase, const void *pRebase 12005 ); 12006 12007 /* 12008 ** CAPI3REF: Rebase a changeset 12009 ** EXPERIMENTAL 12010 ** 12011 ** Argument pIn must point to a buffer containing a changeset nIn bytes 12012 ** in size. This function allocates and populates a buffer with a copy 12013 ** of the changeset rebased according to the configuration of the 12014 ** rebaser object passed as the first argument. If successful, (*ppOut) 12015 ** is set to point to the new buffer containing the rebased changeset and 12016 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 12017 ** responsibility of the caller to eventually free the new buffer using 12018 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 12019 ** are set to zero and an SQLite error code returned. 12020 */ 12021 SQLITE_API int sqlite3rebaser_rebase( 12022 sqlite3_rebaser*, 12023 int nIn, const void *pIn, 12024 int *pnOut, void **ppOut 12025 ); 12026 12027 /* 12028 ** CAPI3REF: Delete a changeset rebaser object. 12029 ** EXPERIMENTAL 12030 ** 12031 ** Delete the changeset rebaser object and all associated resources. There 12032 ** should be one call to this function for each successful invocation 12033 ** of sqlite3rebaser_create(). 12034 */ 12035 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 12036 12037 /* 12038 ** CAPI3REF: Streaming Versions of API functions. 12039 ** 12040 ** The six streaming API xxx_strm() functions serve similar purposes to the 12041 ** corresponding non-streaming API functions: 12042 ** 12043 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 12044 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 12045 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 12046 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 12047 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 12048 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 12049 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 12050 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 12051 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 12052 ** </table> 12053 ** 12054 ** Non-streaming functions that accept changesets (or patchsets) as input 12055 ** require that the entire changeset be stored in a single buffer in memory. 12056 ** Similarly, those that return a changeset or patchset do so by returning 12057 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 12058 ** Normally this is convenient. However, if an application running in a 12059 ** low-memory environment is required to handle very large changesets, the 12060 ** large contiguous memory allocations required can become onerous. 12061 ** 12062 ** In order to avoid this problem, instead of a single large buffer, input 12063 ** is passed to a streaming API functions by way of a callback function that 12064 ** the sessions module invokes to incrementally request input data as it is 12065 ** required. In all cases, a pair of API function parameters such as 12066 ** 12067 ** <pre> 12068 ** int nChangeset, 12069 ** void *pChangeset, 12070 ** </pre> 12071 ** 12072 ** Is replaced by: 12073 ** 12074 ** <pre> 12075 ** int (*xInput)(void *pIn, void *pData, int *pnData), 12076 ** void *pIn, 12077 ** </pre> 12078 ** 12079 ** Each time the xInput callback is invoked by the sessions module, the first 12080 ** argument passed is a copy of the supplied pIn context pointer. The second 12081 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 12082 ** error occurs the xInput method should copy up to (*pnData) bytes of data 12083 ** into the buffer and set (*pnData) to the actual number of bytes copied 12084 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 12085 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 12086 ** error code should be returned. In all cases, if an xInput callback returns 12087 ** an error, all processing is abandoned and the streaming API function 12088 ** returns a copy of the error code to the caller. 12089 ** 12090 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 12091 ** invoked by the sessions module at any point during the lifetime of the 12092 ** iterator. If such an xInput callback returns an error, the iterator enters 12093 ** an error state, whereby all subsequent calls to iterator functions 12094 ** immediately fail with the same error code as returned by xInput. 12095 ** 12096 ** Similarly, streaming API functions that return changesets (or patchsets) 12097 ** return them in chunks by way of a callback function instead of via a 12098 ** pointer to a single large buffer. In this case, a pair of parameters such 12099 ** as: 12100 ** 12101 ** <pre> 12102 ** int *pnChangeset, 12103 ** void **ppChangeset, 12104 ** </pre> 12105 ** 12106 ** Is replaced by: 12107 ** 12108 ** <pre> 12109 ** int (*xOutput)(void *pOut, const void *pData, int nData), 12110 ** void *pOut 12111 ** </pre> 12112 ** 12113 ** The xOutput callback is invoked zero or more times to return data to 12114 ** the application. The first parameter passed to each call is a copy of the 12115 ** pOut pointer supplied by the application. The second parameter, pData, 12116 ** points to a buffer nData bytes in size containing the chunk of output 12117 ** data being returned. If the xOutput callback successfully processes the 12118 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 12119 ** it should return some other SQLite error code. In this case processing 12120 ** is immediately abandoned and the streaming API function returns a copy 12121 ** of the xOutput error code to the application. 12122 ** 12123 ** The sessions module never invokes an xOutput callback with the third 12124 ** parameter set to a value less than or equal to zero. Other than this, 12125 ** no guarantees are made as to the size of the chunks of data returned. 12126 */ 12127 SQLITE_API int sqlite3changeset_apply_strm( 12128 sqlite3 *db, /* Apply change to "main" db of this handle */ 12129 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 12130 void *pIn, /* First arg for xInput */ 12131 int(*xFilter)( 12132 void *pCtx, /* Copy of sixth arg to _apply() */ 12133 const char *zTab /* Table name */ 12134 ), 12135 int(*xConflict)( 12136 void *pCtx, /* Copy of sixth arg to _apply() */ 12137 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12138 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12139 ), 12140 void *pCtx /* First argument passed to xConflict */ 12141 ); 12142 SQLITE_API int sqlite3changeset_apply_v2_strm( 12143 sqlite3 *db, /* Apply change to "main" db of this handle */ 12144 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 12145 void *pIn, /* First arg for xInput */ 12146 int(*xFilter)( 12147 void *pCtx, /* Copy of sixth arg to _apply() */ 12148 const char *zTab /* Table name */ 12149 ), 12150 int(*xConflict)( 12151 void *pCtx, /* Copy of sixth arg to _apply() */ 12152 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12153 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12154 ), 12155 void *pCtx, /* First argument passed to xConflict */ 12156 void **ppRebase, int *pnRebase, 12157 int flags 12158 ); 12159 SQLITE_API int sqlite3changeset_concat_strm( 12160 int (*xInputA)(void *pIn, void *pData, int *pnData), 12161 void *pInA, 12162 int (*xInputB)(void *pIn, void *pData, int *pnData), 12163 void *pInB, 12164 int (*xOutput)(void *pOut, const void *pData, int nData), 12165 void *pOut 12166 ); 12167 SQLITE_API int sqlite3changeset_invert_strm( 12168 int (*xInput)(void *pIn, void *pData, int *pnData), 12169 void *pIn, 12170 int (*xOutput)(void *pOut, const void *pData, int nData), 12171 void *pOut 12172 ); 12173 SQLITE_API int sqlite3changeset_start_strm( 12174 sqlite3_changeset_iter **pp, 12175 int (*xInput)(void *pIn, void *pData, int *pnData), 12176 void *pIn 12177 ); 12178 SQLITE_API int sqlite3changeset_start_v2_strm( 12179 sqlite3_changeset_iter **pp, 12180 int (*xInput)(void *pIn, void *pData, int *pnData), 12181 void *pIn, 12182 int flags 12183 ); 12184 SQLITE_API int sqlite3session_changeset_strm( 12185 sqlite3_session *pSession, 12186 int (*xOutput)(void *pOut, const void *pData, int nData), 12187 void *pOut 12188 ); 12189 SQLITE_API int sqlite3session_patchset_strm( 12190 sqlite3_session *pSession, 12191 int (*xOutput)(void *pOut, const void *pData, int nData), 12192 void *pOut 12193 ); 12194 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 12195 int (*xInput)(void *pIn, void *pData, int *pnData), 12196 void *pIn 12197 ); 12198 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 12199 int (*xOutput)(void *pOut, const void *pData, int nData), 12200 void *pOut 12201 ); 12202 SQLITE_API int sqlite3rebaser_rebase_strm( 12203 sqlite3_rebaser *pRebaser, 12204 int (*xInput)(void *pIn, void *pData, int *pnData), 12205 void *pIn, 12206 int (*xOutput)(void *pOut, const void *pData, int nData), 12207 void *pOut 12208 ); 12209 12210 /* 12211 ** CAPI3REF: Configure global parameters 12212 ** 12213 ** The sqlite3session_config() interface is used to make global configuration 12214 ** changes to the sessions module in order to tune it to the specific needs 12215 ** of the application. 12216 ** 12217 ** The sqlite3session_config() interface is not threadsafe. If it is invoked 12218 ** while any other thread is inside any other sessions method then the 12219 ** results are undefined. Furthermore, if it is invoked after any sessions 12220 ** related objects have been created, the results are also undefined. 12221 ** 12222 ** The first argument to the sqlite3session_config() function must be one 12223 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The 12224 ** interpretation of the (void*) value passed as the second parameter and 12225 ** the effect of calling this function depends on the value of the first 12226 ** parameter. 12227 ** 12228 ** <dl> 12229 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd> 12230 ** By default, the sessions module streaming interfaces attempt to input 12231 ** and output data in approximately 1 KiB chunks. This operand may be used 12232 ** to set and query the value of this configuration setting. The pointer 12233 ** passed as the second argument must point to a value of type (int). 12234 ** If this value is greater than 0, it is used as the new streaming data 12235 ** chunk size for both input and output. Before returning, the (int) value 12236 ** pointed to by pArg is set to the final value of the streaming interface 12237 ** chunk size. 12238 ** </dl> 12239 ** 12240 ** This function returns SQLITE_OK if successful, or an SQLite error code 12241 ** otherwise. 12242 */ 12243 SQLITE_API int sqlite3session_config(int op, void *pArg); 12244 12245 /* 12246 ** CAPI3REF: Values for sqlite3session_config(). 12247 */ 12248 #define SQLITE_SESSION_CONFIG_STRMSIZE 1 12249 12250 /* 12251 ** Make sure we can call this stuff from C++. 12252 */ 12253 #ifdef __cplusplus 12254 } 12255 #endif 12256 12257 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 12258 12259 /******** End of sqlite3session.h *********/ 12260 /******** Begin file fts5.h *********/ 12261 /* 12262 ** 2014 May 31 12263 ** 12264 ** The author disclaims copyright to this source code. In place of 12265 ** a legal notice, here is a blessing: 12266 ** 12267 ** May you do good and not evil. 12268 ** May you find forgiveness for yourself and forgive others. 12269 ** May you share freely, never taking more than you give. 12270 ** 12271 ****************************************************************************** 12272 ** 12273 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 12274 ** FTS5 may be extended with: 12275 ** 12276 ** * custom tokenizers, and 12277 ** * custom auxiliary functions. 12278 */ 12279 12280 12281 #ifndef _FTS5_H 12282 #define _FTS5_H 12283 12284 12285 #ifdef __cplusplus 12286 extern "C" { 12287 #endif 12288 12289 /************************************************************************* 12290 ** CUSTOM AUXILIARY FUNCTIONS 12291 ** 12292 ** Virtual table implementations may overload SQL functions by implementing 12293 ** the sqlite3_module.xFindFunction() method. 12294 */ 12295 12296 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 12297 typedef struct Fts5Context Fts5Context; 12298 typedef struct Fts5PhraseIter Fts5PhraseIter; 12299 12300 typedef void (*fts5_extension_function)( 12301 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 12302 Fts5Context *pFts, /* First arg to pass to pApi functions */ 12303 sqlite3_context *pCtx, /* Context for returning result/error */ 12304 int nVal, /* Number of values in apVal[] array */ 12305 sqlite3_value **apVal /* Array of trailing arguments */ 12306 ); 12307 12308 struct Fts5PhraseIter { 12309 const unsigned char *a; 12310 const unsigned char *b; 12311 }; 12312 12313 /* 12314 ** EXTENSION API FUNCTIONS 12315 ** 12316 ** xUserData(pFts): 12317 ** Return a copy of the context pointer the extension function was 12318 ** registered with. 12319 ** 12320 ** xColumnTotalSize(pFts, iCol, pnToken): 12321 ** If parameter iCol is less than zero, set output variable *pnToken 12322 ** to the total number of tokens in the FTS5 table. Or, if iCol is 12323 ** non-negative but less than the number of columns in the table, return 12324 ** the total number of tokens in column iCol, considering all rows in 12325 ** the FTS5 table. 12326 ** 12327 ** If parameter iCol is greater than or equal to the number of columns 12328 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 12329 ** an OOM condition or IO error), an appropriate SQLite error code is 12330 ** returned. 12331 ** 12332 ** xColumnCount(pFts): 12333 ** Return the number of columns in the table. 12334 ** 12335 ** xColumnSize(pFts, iCol, pnToken): 12336 ** If parameter iCol is less than zero, set output variable *pnToken 12337 ** to the total number of tokens in the current row. Or, if iCol is 12338 ** non-negative but less than the number of columns in the table, set 12339 ** *pnToken to the number of tokens in column iCol of the current row. 12340 ** 12341 ** If parameter iCol is greater than or equal to the number of columns 12342 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 12343 ** an OOM condition or IO error), an appropriate SQLite error code is 12344 ** returned. 12345 ** 12346 ** This function may be quite inefficient if used with an FTS5 table 12347 ** created with the "columnsize=0" option. 12348 ** 12349 ** xColumnText: 12350 ** This function attempts to retrieve the text of column iCol of the 12351 ** current document. If successful, (*pz) is set to point to a buffer 12352 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 12353 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 12354 ** if an error occurs, an SQLite error code is returned and the final values 12355 ** of (*pz) and (*pn) are undefined. 12356 ** 12357 ** xPhraseCount: 12358 ** Returns the number of phrases in the current query expression. 12359 ** 12360 ** xPhraseSize: 12361 ** Returns the number of tokens in phrase iPhrase of the query. Phrases 12362 ** are numbered starting from zero. 12363 ** 12364 ** xInstCount: 12365 ** Set *pnInst to the total number of occurrences of all phrases within 12366 ** the query within the current row. Return SQLITE_OK if successful, or 12367 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 12368 ** 12369 ** This API can be quite slow if used with an FTS5 table created with the 12370 ** "detail=none" or "detail=column" option. If the FTS5 table is created 12371 ** with either "detail=none" or "detail=column" and "content=" option 12372 ** (i.e. if it is a contentless table), then this API always returns 0. 12373 ** 12374 ** xInst: 12375 ** Query for the details of phrase match iIdx within the current row. 12376 ** Phrase matches are numbered starting from zero, so the iIdx argument 12377 ** should be greater than or equal to zero and smaller than the value 12378 ** output by xInstCount(). 12379 ** 12380 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol 12381 ** to the column in which it occurs and *piOff the token offset of the 12382 ** first token of the phrase. Returns SQLITE_OK if successful, or an error 12383 ** code (i.e. SQLITE_NOMEM) if an error occurs. 12384 ** 12385 ** This API can be quite slow if used with an FTS5 table created with the 12386 ** "detail=none" or "detail=column" option. 12387 ** 12388 ** xRowid: 12389 ** Returns the rowid of the current row. 12390 ** 12391 ** xTokenize: 12392 ** Tokenize text using the tokenizer belonging to the FTS5 table. 12393 ** 12394 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 12395 ** This API function is used to query the FTS table for phrase iPhrase 12396 ** of the current query. Specifically, a query equivalent to: 12397 ** 12398 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 12399 ** 12400 ** with $p set to a phrase equivalent to the phrase iPhrase of the 12401 ** current query is executed. Any column filter that applies to 12402 ** phrase iPhrase of the current query is included in $p. For each 12403 ** row visited, the callback function passed as the fourth argument 12404 ** is invoked. The context and API objects passed to the callback 12405 ** function may be used to access the properties of each matched row. 12406 ** Invoking Api.xUserData() returns a copy of the pointer passed as 12407 ** the third argument to pUserData. 12408 ** 12409 ** If the callback function returns any value other than SQLITE_OK, the 12410 ** query is abandoned and the xQueryPhrase function returns immediately. 12411 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 12412 ** Otherwise, the error code is propagated upwards. 12413 ** 12414 ** If the query runs to completion without incident, SQLITE_OK is returned. 12415 ** Or, if some error occurs before the query completes or is aborted by 12416 ** the callback, an SQLite error code is returned. 12417 ** 12418 ** 12419 ** xSetAuxdata(pFts5, pAux, xDelete) 12420 ** 12421 ** Save the pointer passed as the second argument as the extension function's 12422 ** "auxiliary data". The pointer may then be retrieved by the current or any 12423 ** future invocation of the same fts5 extension function made as part of 12424 ** the same MATCH query using the xGetAuxdata() API. 12425 ** 12426 ** Each extension function is allocated a single auxiliary data slot for 12427 ** each FTS query (MATCH expression). If the extension function is invoked 12428 ** more than once for a single FTS query, then all invocations share a 12429 ** single auxiliary data context. 12430 ** 12431 ** If there is already an auxiliary data pointer when this function is 12432 ** invoked, then it is replaced by the new pointer. If an xDelete callback 12433 ** was specified along with the original pointer, it is invoked at this 12434 ** point. 12435 ** 12436 ** The xDelete callback, if one is specified, is also invoked on the 12437 ** auxiliary data pointer after the FTS5 query has finished. 12438 ** 12439 ** If an error (e.g. an OOM condition) occurs within this function, 12440 ** the auxiliary data is set to NULL and an error code returned. If the 12441 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 12442 ** pointer before returning. 12443 ** 12444 ** 12445 ** xGetAuxdata(pFts5, bClear) 12446 ** 12447 ** Returns the current auxiliary data pointer for the fts5 extension 12448 ** function. See the xSetAuxdata() method for details. 12449 ** 12450 ** If the bClear argument is non-zero, then the auxiliary data is cleared 12451 ** (set to NULL) before this function returns. In this case the xDelete, 12452 ** if any, is not invoked. 12453 ** 12454 ** 12455 ** xRowCount(pFts5, pnRow) 12456 ** 12457 ** This function is used to retrieve the total number of rows in the table. 12458 ** In other words, the same value that would be returned by: 12459 ** 12460 ** SELECT count(*) FROM ftstable; 12461 ** 12462 ** xPhraseFirst() 12463 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 12464 ** method, to iterate through all instances of a single query phrase within 12465 ** the current row. This is the same information as is accessible via the 12466 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 12467 ** to use, this API may be faster under some circumstances. To iterate 12468 ** through instances of phrase iPhrase, use the following code: 12469 ** 12470 ** Fts5PhraseIter iter; 12471 ** int iCol, iOff; 12472 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 12473 ** iCol>=0; 12474 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 12475 ** ){ 12476 ** // An instance of phrase iPhrase at offset iOff of column iCol 12477 ** } 12478 ** 12479 ** The Fts5PhraseIter structure is defined above. Applications should not 12480 ** modify this structure directly - it should only be used as shown above 12481 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 12482 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 12483 ** 12484 ** This API can be quite slow if used with an FTS5 table created with the 12485 ** "detail=none" or "detail=column" option. If the FTS5 table is created 12486 ** with either "detail=none" or "detail=column" and "content=" option 12487 ** (i.e. if it is a contentless table), then this API always iterates 12488 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 12489 ** 12490 ** xPhraseNext() 12491 ** See xPhraseFirst above. 12492 ** 12493 ** xPhraseFirstColumn() 12494 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 12495 ** and xPhraseNext() APIs described above. The difference is that instead 12496 ** of iterating through all instances of a phrase in the current row, these 12497 ** APIs are used to iterate through the set of columns in the current row 12498 ** that contain one or more instances of a specified phrase. For example: 12499 ** 12500 ** Fts5PhraseIter iter; 12501 ** int iCol; 12502 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 12503 ** iCol>=0; 12504 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 12505 ** ){ 12506 ** // Column iCol contains at least one instance of phrase iPhrase 12507 ** } 12508 ** 12509 ** This API can be quite slow if used with an FTS5 table created with the 12510 ** "detail=none" option. If the FTS5 table is created with either 12511 ** "detail=none" "content=" option (i.e. if it is a contentless table), 12512 ** then this API always iterates through an empty set (all calls to 12513 ** xPhraseFirstColumn() set iCol to -1). 12514 ** 12515 ** The information accessed using this API and its companion 12516 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 12517 ** (or xInst/xInstCount). The chief advantage of this API is that it is 12518 ** significantly more efficient than those alternatives when used with 12519 ** "detail=column" tables. 12520 ** 12521 ** xPhraseNextColumn() 12522 ** See xPhraseFirstColumn above. 12523 */ 12524 struct Fts5ExtensionApi { 12525 int iVersion; /* Currently always set to 3 */ 12526 12527 void *(*xUserData)(Fts5Context*); 12528 12529 int (*xColumnCount)(Fts5Context*); 12530 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 12531 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 12532 12533 int (*xTokenize)(Fts5Context*, 12534 const char *pText, int nText, /* Text to tokenize */ 12535 void *pCtx, /* Context passed to xToken() */ 12536 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 12537 ); 12538 12539 int (*xPhraseCount)(Fts5Context*); 12540 int (*xPhraseSize)(Fts5Context*, int iPhrase); 12541 12542 int (*xInstCount)(Fts5Context*, int *pnInst); 12543 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 12544 12545 sqlite3_int64 (*xRowid)(Fts5Context*); 12546 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 12547 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 12548 12549 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 12550 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 12551 ); 12552 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 12553 void *(*xGetAuxdata)(Fts5Context*, int bClear); 12554 12555 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 12556 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 12557 12558 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 12559 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 12560 }; 12561 12562 /* 12563 ** CUSTOM AUXILIARY FUNCTIONS 12564 *************************************************************************/ 12565 12566 /************************************************************************* 12567 ** CUSTOM TOKENIZERS 12568 ** 12569 ** Applications may also register custom tokenizer types. A tokenizer 12570 ** is registered by providing fts5 with a populated instance of the 12571 ** following structure. All structure methods must be defined, setting 12572 ** any member of the fts5_tokenizer struct to NULL leads to undefined 12573 ** behaviour. The structure methods are expected to function as follows: 12574 ** 12575 ** xCreate: 12576 ** This function is used to allocate and initialize a tokenizer instance. 12577 ** A tokenizer instance is required to actually tokenize text. 12578 ** 12579 ** The first argument passed to this function is a copy of the (void*) 12580 ** pointer provided by the application when the fts5_tokenizer object 12581 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 12582 ** The second and third arguments are an array of nul-terminated strings 12583 ** containing the tokenizer arguments, if any, specified following the 12584 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 12585 ** to create the FTS5 table. 12586 ** 12587 ** The final argument is an output variable. If successful, (*ppOut) 12588 ** should be set to point to the new tokenizer handle and SQLITE_OK 12589 ** returned. If an error occurs, some value other than SQLITE_OK should 12590 ** be returned. In this case, fts5 assumes that the final value of *ppOut 12591 ** is undefined. 12592 ** 12593 ** xDelete: 12594 ** This function is invoked to delete a tokenizer handle previously 12595 ** allocated using xCreate(). Fts5 guarantees that this function will 12596 ** be invoked exactly once for each successful call to xCreate(). 12597 ** 12598 ** xTokenize: 12599 ** This function is expected to tokenize the nText byte string indicated 12600 ** by argument pText. pText may or may not be nul-terminated. The first 12601 ** argument passed to this function is a pointer to an Fts5Tokenizer object 12602 ** returned by an earlier call to xCreate(). 12603 ** 12604 ** The second argument indicates the reason that FTS5 is requesting 12605 ** tokenization of the supplied text. This is always one of the following 12606 ** four values: 12607 ** 12608 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 12609 ** or removed from the FTS table. The tokenizer is being invoked to 12610 ** determine the set of tokens to add to (or delete from) the 12611 ** FTS index. 12612 ** 12613 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 12614 ** against the FTS index. The tokenizer is being called to tokenize 12615 ** a bareword or quoted string specified as part of the query. 12616 ** 12617 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 12618 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 12619 ** followed by a "*" character, indicating that the last token 12620 ** returned by the tokenizer will be treated as a token prefix. 12621 ** 12622 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 12623 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 12624 ** function. Or an fts5_api.xColumnSize() request made by the same 12625 ** on a columnsize=0 database. 12626 ** </ul> 12627 ** 12628 ** For each token in the input string, the supplied callback xToken() must 12629 ** be invoked. The first argument to it should be a copy of the pointer 12630 ** passed as the second argument to xTokenize(). The third and fourth 12631 ** arguments are a pointer to a buffer containing the token text, and the 12632 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 12633 ** of the first byte of and first byte immediately following the text from 12634 ** which the token is derived within the input. 12635 ** 12636 ** The second argument passed to the xToken() callback ("tflags") should 12637 ** normally be set to 0. The exception is if the tokenizer supports 12638 ** synonyms. In this case see the discussion below for details. 12639 ** 12640 ** FTS5 assumes the xToken() callback is invoked for each token in the 12641 ** order that they occur within the input text. 12642 ** 12643 ** If an xToken() callback returns any value other than SQLITE_OK, then 12644 ** the tokenization should be abandoned and the xTokenize() method should 12645 ** immediately return a copy of the xToken() return value. Or, if the 12646 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 12647 ** if an error occurs with the xTokenize() implementation itself, it 12648 ** may abandon the tokenization and return any error code other than 12649 ** SQLITE_OK or SQLITE_DONE. 12650 ** 12651 ** SYNONYM SUPPORT 12652 ** 12653 ** Custom tokenizers may also support synonyms. Consider a case in which a 12654 ** user wishes to query for a phrase such as "first place". Using the 12655 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 12656 ** of "first place" within the document set, but not alternative forms 12657 ** such as "1st place". In some applications, it would be better to match 12658 ** all instances of "first place" or "1st place" regardless of which form 12659 ** the user specified in the MATCH query text. 12660 ** 12661 ** There are several ways to approach this in FTS5: 12662 ** 12663 ** <ol><li> By mapping all synonyms to a single token. In this case, using 12664 ** the above example, this means that the tokenizer returns the 12665 ** same token for inputs "first" and "1st". Say that token is in 12666 ** fact "first", so that when the user inserts the document "I won 12667 ** 1st place" entries are added to the index for tokens "i", "won", 12668 ** "first" and "place". If the user then queries for '1st + place', 12669 ** the tokenizer substitutes "first" for "1st" and the query works 12670 ** as expected. 12671 ** 12672 ** <li> By querying the index for all synonyms of each query term 12673 ** separately. In this case, when tokenizing query text, the 12674 ** tokenizer may provide multiple synonyms for a single term 12675 ** within the document. FTS5 then queries the index for each 12676 ** synonym individually. For example, faced with the query: 12677 ** 12678 ** <codeblock> 12679 ** ... MATCH 'first place'</codeblock> 12680 ** 12681 ** the tokenizer offers both "1st" and "first" as synonyms for the 12682 ** first token in the MATCH query and FTS5 effectively runs a query 12683 ** similar to: 12684 ** 12685 ** <codeblock> 12686 ** ... MATCH '(first OR 1st) place'</codeblock> 12687 ** 12688 ** except that, for the purposes of auxiliary functions, the query 12689 ** still appears to contain just two phrases - "(first OR 1st)" 12690 ** being treated as a single phrase. 12691 ** 12692 ** <li> By adding multiple synonyms for a single term to the FTS index. 12693 ** Using this method, when tokenizing document text, the tokenizer 12694 ** provides multiple synonyms for each token. So that when a 12695 ** document such as "I won first place" is tokenized, entries are 12696 ** added to the FTS index for "i", "won", "first", "1st" and 12697 ** "place". 12698 ** 12699 ** This way, even if the tokenizer does not provide synonyms 12700 ** when tokenizing query text (it should not - to do so would be 12701 ** inefficient), it doesn't matter if the user queries for 12702 ** 'first + place' or '1st + place', as there are entries in the 12703 ** FTS index corresponding to both forms of the first token. 12704 ** </ol> 12705 ** 12706 ** Whether it is parsing document or query text, any call to xToken that 12707 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 12708 ** is considered to supply a synonym for the previous token. For example, 12709 ** when parsing the document "I won first place", a tokenizer that supports 12710 ** synonyms would call xToken() 5 times, as follows: 12711 ** 12712 ** <codeblock> 12713 ** xToken(pCtx, 0, "i", 1, 0, 1); 12714 ** xToken(pCtx, 0, "won", 3, 2, 5); 12715 ** xToken(pCtx, 0, "first", 5, 6, 11); 12716 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 12717 ** xToken(pCtx, 0, "place", 5, 12, 17); 12718 **</codeblock> 12719 ** 12720 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 12721 ** xToken() is called. Multiple synonyms may be specified for a single token 12722 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 12723 ** There is no limit to the number of synonyms that may be provided for a 12724 ** single token. 12725 ** 12726 ** In many cases, method (1) above is the best approach. It does not add 12727 ** extra data to the FTS index or require FTS5 to query for multiple terms, 12728 ** so it is efficient in terms of disk space and query speed. However, it 12729 ** does not support prefix queries very well. If, as suggested above, the 12730 ** token "first" is substituted for "1st" by the tokenizer, then the query: 12731 ** 12732 ** <codeblock> 12733 ** ... MATCH '1s*'</codeblock> 12734 ** 12735 ** will not match documents that contain the token "1st" (as the tokenizer 12736 ** will probably not map "1s" to any prefix of "first"). 12737 ** 12738 ** For full prefix support, method (3) may be preferred. In this case, 12739 ** because the index contains entries for both "first" and "1st", prefix 12740 ** queries such as 'fi*' or '1s*' will match correctly. However, because 12741 ** extra entries are added to the FTS index, this method uses more space 12742 ** within the database. 12743 ** 12744 ** Method (2) offers a midpoint between (1) and (3). Using this method, 12745 ** a query such as '1s*' will match documents that contain the literal 12746 ** token "1st", but not "first" (assuming the tokenizer is not able to 12747 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 12748 ** will match against "1st" and "first". This method does not require 12749 ** extra disk space, as no extra entries are added to the FTS index. 12750 ** On the other hand, it may require more CPU cycles to run MATCH queries, 12751 ** as separate queries of the FTS index are required for each synonym. 12752 ** 12753 ** When using methods (2) or (3), it is important that the tokenizer only 12754 ** provide synonyms when tokenizing document text (method (2)) or query 12755 ** text (method (3)), not both. Doing so will not cause any errors, but is 12756 ** inefficient. 12757 */ 12758 typedef struct Fts5Tokenizer Fts5Tokenizer; 12759 typedef struct fts5_tokenizer fts5_tokenizer; 12760 struct fts5_tokenizer { 12761 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 12762 void (*xDelete)(Fts5Tokenizer*); 12763 int (*xTokenize)(Fts5Tokenizer*, 12764 void *pCtx, 12765 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 12766 const char *pText, int nText, 12767 int (*xToken)( 12768 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 12769 int tflags, /* Mask of FTS5_TOKEN_* flags */ 12770 const char *pToken, /* Pointer to buffer containing token */ 12771 int nToken, /* Size of token in bytes */ 12772 int iStart, /* Byte offset of token within input text */ 12773 int iEnd /* Byte offset of end of token within input text */ 12774 ) 12775 ); 12776 }; 12777 12778 /* Flags that may be passed as the third argument to xTokenize() */ 12779 #define FTS5_TOKENIZE_QUERY 0x0001 12780 #define FTS5_TOKENIZE_PREFIX 0x0002 12781 #define FTS5_TOKENIZE_DOCUMENT 0x0004 12782 #define FTS5_TOKENIZE_AUX 0x0008 12783 12784 /* Flags that may be passed by the tokenizer implementation back to FTS5 12785 ** as the third argument to the supplied xToken callback. */ 12786 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 12787 12788 /* 12789 ** END OF CUSTOM TOKENIZERS 12790 *************************************************************************/ 12791 12792 /************************************************************************* 12793 ** FTS5 EXTENSION REGISTRATION API 12794 */ 12795 typedef struct fts5_api fts5_api; 12796 struct fts5_api { 12797 int iVersion; /* Currently always set to 2 */ 12798 12799 /* Create a new tokenizer */ 12800 int (*xCreateTokenizer)( 12801 fts5_api *pApi, 12802 const char *zName, 12803 void *pContext, 12804 fts5_tokenizer *pTokenizer, 12805 void (*xDestroy)(void*) 12806 ); 12807 12808 /* Find an existing tokenizer */ 12809 int (*xFindTokenizer)( 12810 fts5_api *pApi, 12811 const char *zName, 12812 void **ppContext, 12813 fts5_tokenizer *pTokenizer 12814 ); 12815 12816 /* Create a new auxiliary function */ 12817 int (*xCreateFunction)( 12818 fts5_api *pApi, 12819 const char *zName, 12820 void *pContext, 12821 fts5_extension_function xFunction, 12822 void (*xDestroy)(void*) 12823 ); 12824 }; 12825 12826 /* 12827 ** END OF REGISTRATION API 12828 *************************************************************************/ 12829 12830 #ifdef __cplusplus 12831 } /* end of the 'extern "C"' block */ 12832 #endif 12833 12834 #endif /* _FTS5_H */ 12835 12836 /******** End of fts5.h *********/ 12837