1 #ifndef USE_LIBSQLITE3 2 /* 3 ** 2001-09-15 4 ** 5 ** The author disclaims copyright to this source code. In place of 6 ** a legal notice, here is a blessing: 7 ** 8 ** May you do good and not evil. 9 ** May you find forgiveness for yourself and forgive others. 10 ** May you share freely, never taking more than you give. 11 ** 12 ************************************************************************* 13 ** This header file defines the interface that the SQLite library 14 ** presents to client programs. If a C-function, structure, datatype, 15 ** or constant definition does not appear in this file, then it is 16 ** not a published API of SQLite, is subject to change without 17 ** notice, and should not be referenced by programs that use SQLite. 18 ** 19 ** Some of the definitions that are in this file are marked as 20 ** "experimental". Experimental interfaces are normally new 21 ** features recently added to SQLite. We do not anticipate changes 22 ** to experimental interfaces but reserve the right to make minor changes 23 ** if experience from use "in the wild" suggest such changes are prudent. 24 ** 25 ** The official C-language API documentation for SQLite is derived 26 ** from comments in this file. This file is the authoritative source 27 ** on how SQLite interfaces are supposed to operate. 28 ** 29 ** The name of this file under configuration management is "sqlite.h.in". 30 ** The makefile makes some minor changes to this file (such as inserting 31 ** the version number) and changes its name to "sqlite3.h" as 32 ** part of the build process. 33 */ 34 #ifndef SQLITE3_H 35 #define SQLITE3_H 36 #include <stdarg.h> /* Needed for the definition of va_list */ 37 38 /* 39 ** Make sure we can call this stuff from C++. 40 */ 41 #ifdef __cplusplus 42 extern "C" { 43 #endif 44 45 46 /* 47 ** Provide the ability to override linkage features of the interface. 48 */ 49 #ifndef SQLITE_EXTERN 50 # define SQLITE_EXTERN extern 51 #endif 52 #ifndef SQLITE_API 53 # define SQLITE_API 54 #endif 55 #ifndef SQLITE_CDECL 56 # define SQLITE_CDECL 57 #endif 58 #ifndef SQLITE_APICALL 59 # define SQLITE_APICALL 60 #endif 61 #ifndef SQLITE_STDCALL 62 # define SQLITE_STDCALL SQLITE_APICALL 63 #endif 64 #ifndef SQLITE_CALLBACK 65 # define SQLITE_CALLBACK 66 #endif 67 #ifndef SQLITE_SYSAPI 68 # define SQLITE_SYSAPI 69 #endif 70 71 /* 72 ** These no-op macros are used in front of interfaces to mark those 73 ** interfaces as either deprecated or experimental. New applications 74 ** should not use deprecated interfaces - they are supported for backwards 75 ** compatibility only. Application writers should be aware that 76 ** experimental interfaces are subject to change in point releases. 77 ** 78 ** These macros used to resolve to various kinds of compiler magic that 79 ** would generate warning messages when they were used. But that 80 ** compiler magic ended up generating such a flurry of bug reports 81 ** that we have taken it all out and gone back to using simple 82 ** noop macros. 83 */ 84 #define SQLITE_DEPRECATED 85 #define SQLITE_EXPERIMENTAL 86 87 /* 88 ** Ensure these symbols were not defined by some previous header file. 89 */ 90 #ifdef SQLITE_VERSION 91 # undef SQLITE_VERSION 92 #endif 93 #ifdef SQLITE_VERSION_NUMBER 94 # undef SQLITE_VERSION_NUMBER 95 #endif 96 97 /* 98 ** CAPI3REF: Compile-Time Library Version Numbers 99 ** 100 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 101 ** evaluates to a string literal that is the SQLite version in the 102 ** format "X.Y.Z" where X is the major version number (always 3 for 103 ** SQLite3) and Y is the minor version number and Z is the release number.)^ 104 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 105 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 106 ** numbers used in [SQLITE_VERSION].)^ 107 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 108 ** be larger than the release from which it is derived. Either Y will 109 ** be held constant and Z will be incremented or else Y will be incremented 110 ** and Z will be reset to zero. 111 ** 112 ** Since [version 3.6.18] ([dateof:3.6.18]), 113 ** SQLite source code has been stored in the 114 ** <a href="http://www.fossil-scm.org/">Fossil configuration management 115 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 116 ** a string which identifies a particular check-in of SQLite 117 ** within its configuration management system. ^The SQLITE_SOURCE_ID 118 ** string contains the date and time of the check-in (UTC) and a SHA1 119 ** or SHA3-256 hash of the entire source tree. If the source code has 120 ** been edited in any way since it was last checked in, then the last 121 ** four hexadecimal digits of the hash may be modified. 122 ** 123 ** See also: [sqlite3_libversion()], 124 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 125 ** [sqlite_version()] and [sqlite_source_id()]. 126 */ 127 #define SQLITE_VERSION "3.36.0" 128 #define SQLITE_VERSION_NUMBER 3036000 129 #define SQLITE_SOURCE_ID "2021-06-18 18:36:39 5c9a6c06871cb9fe42814af9c039eb6da5427a6ec28f187af7ebfb62eafa66e5" 130 131 /* 132 ** CAPI3REF: Run-Time Library Version Numbers 133 ** KEYWORDS: sqlite3_version sqlite3_sourceid 134 ** 135 ** These interfaces provide the same information as the [SQLITE_VERSION], 136 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 137 ** but are associated with the library instead of the header file. ^(Cautious 138 ** programmers might include assert() statements in their application to 139 ** verify that values returned by these interfaces match the macros in 140 ** the header, and thus ensure that the application is 141 ** compiled with matching library and header files. 142 ** 143 ** <blockquote><pre> 144 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 145 ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 146 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 147 ** </pre></blockquote>)^ 148 ** 149 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 150 ** macro. ^The sqlite3_libversion() function returns a pointer to the 151 ** to the sqlite3_version[] string constant. The sqlite3_libversion() 152 ** function is provided for use in DLLs since DLL users usually do not have 153 ** direct access to string constants within the DLL. ^The 154 ** sqlite3_libversion_number() function returns an integer equal to 155 ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 156 ** a pointer to a string constant whose value is the same as the 157 ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 158 ** using an edited copy of [the amalgamation], then the last four characters 159 ** of the hash might be different from [SQLITE_SOURCE_ID].)^ 160 ** 161 ** See also: [sqlite_version()] and [sqlite_source_id()]. 162 */ 163 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 164 SQLITE_API const char *sqlite3_libversion(void); 165 SQLITE_API const char *sqlite3_sourceid(void); 166 SQLITE_API int sqlite3_libversion_number(void); 167 168 /* 169 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 170 ** 171 ** ^The sqlite3_compileoption_used() function returns 0 or 1 172 ** indicating whether the specified option was defined at 173 ** compile time. ^The SQLITE_ prefix may be omitted from the 174 ** option name passed to sqlite3_compileoption_used(). 175 ** 176 ** ^The sqlite3_compileoption_get() function allows iterating 177 ** over the list of options that were defined at compile time by 178 ** returning the N-th compile time option string. ^If N is out of range, 179 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 180 ** prefix is omitted from any strings returned by 181 ** sqlite3_compileoption_get(). 182 ** 183 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 184 ** and sqlite3_compileoption_get() may be omitted by specifying the 185 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 186 ** 187 ** See also: SQL functions [sqlite_compileoption_used()] and 188 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 189 */ 190 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 191 SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 192 SQLITE_API const char *sqlite3_compileoption_get(int N); 193 #else 194 # define sqlite3_compileoption_used(X) 0 195 # define sqlite3_compileoption_get(X) ((void*)0) 196 #endif 197 198 /* 199 ** CAPI3REF: Test To See If The Library Is Threadsafe 200 ** 201 ** ^The sqlite3_threadsafe() function returns zero if and only if 202 ** SQLite was compiled with mutexing code omitted due to the 203 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 204 ** 205 ** SQLite can be compiled with or without mutexes. When 206 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 207 ** are enabled and SQLite is threadsafe. When the 208 ** [SQLITE_THREADSAFE] macro is 0, 209 ** the mutexes are omitted. Without the mutexes, it is not safe 210 ** to use SQLite concurrently from more than one thread. 211 ** 212 ** Enabling mutexes incurs a measurable performance penalty. 213 ** So if speed is of utmost importance, it makes sense to disable 214 ** the mutexes. But for maximum safety, mutexes should be enabled. 215 ** ^The default behavior is for mutexes to be enabled. 216 ** 217 ** This interface can be used by an application to make sure that the 218 ** version of SQLite that it is linking against was compiled with 219 ** the desired setting of the [SQLITE_THREADSAFE] macro. 220 ** 221 ** This interface only reports on the compile-time mutex setting 222 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 223 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 224 ** can be fully or partially disabled using a call to [sqlite3_config()] 225 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 226 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 227 ** sqlite3_threadsafe() function shows only the compile-time setting of 228 ** thread safety, not any run-time changes to that setting made by 229 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 230 ** is unchanged by calls to sqlite3_config().)^ 231 ** 232 ** See the [threading mode] documentation for additional information. 233 */ 234 SQLITE_API int sqlite3_threadsafe(void); 235 236 /* 237 ** CAPI3REF: Database Connection Handle 238 ** KEYWORDS: {database connection} {database connections} 239 ** 240 ** Each open SQLite database is represented by a pointer to an instance of 241 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 242 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 243 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 244 ** and [sqlite3_close_v2()] are its destructors. There are many other 245 ** interfaces (such as 246 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 247 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 248 ** sqlite3 object. 249 */ 250 typedef struct sqlite3 sqlite3; 251 252 /* 253 ** CAPI3REF: 64-Bit Integer Types 254 ** KEYWORDS: sqlite_int64 sqlite_uint64 255 ** 256 ** Because there is no cross-platform way to specify 64-bit integer types 257 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 258 ** 259 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 260 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 261 ** compatibility only. 262 ** 263 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 264 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 265 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 266 ** between 0 and +18446744073709551615 inclusive. 267 */ 268 #ifdef SQLITE_INT64_TYPE 269 typedef SQLITE_INT64_TYPE sqlite_int64; 270 # ifdef SQLITE_UINT64_TYPE 271 typedef SQLITE_UINT64_TYPE sqlite_uint64; 272 # else 273 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 274 # endif 275 #elif defined(_MSC_VER) || defined(__BORLANDC__) 276 typedef __int64 sqlite_int64; 277 typedef unsigned __int64 sqlite_uint64; 278 #else 279 typedef long long int sqlite_int64; 280 typedef unsigned long long int sqlite_uint64; 281 #endif 282 typedef sqlite_int64 sqlite3_int64; 283 typedef sqlite_uint64 sqlite3_uint64; 284 285 /* 286 ** If compiling for a processor that lacks floating point support, 287 ** substitute integer for floating-point. 288 */ 289 #ifdef SQLITE_OMIT_FLOATING_POINT 290 # define double sqlite3_int64 291 #endif 292 293 /* 294 ** CAPI3REF: Closing A Database Connection 295 ** DESTRUCTOR: sqlite3 296 ** 297 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 298 ** for the [sqlite3] object. 299 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 300 ** the [sqlite3] object is successfully destroyed and all associated 301 ** resources are deallocated. 302 ** 303 ** Ideally, applications should [sqlite3_finalize | finalize] all 304 ** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and 305 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 306 ** with the [sqlite3] object prior to attempting to close the object. 307 ** ^If the database connection is associated with unfinalized prepared 308 ** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then 309 ** sqlite3_close() will leave the database connection open and return 310 ** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared 311 ** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups, 312 ** it returns [SQLITE_OK] regardless, but instead of deallocating the database 313 ** connection immediately, it marks the database connection as an unusable 314 ** "zombie" and makes arrangements to automatically deallocate the database 315 ** connection after all prepared statements are finalized, all BLOB handles 316 ** are closed, and all backups have finished. The sqlite3_close_v2() interface 317 ** is intended for use with host languages that are garbage collected, and 318 ** where the order in which destructors are called is arbitrary. 319 ** 320 ** ^If an [sqlite3] object is destroyed while a transaction is open, 321 ** the transaction is automatically rolled back. 322 ** 323 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 324 ** must be either a NULL 325 ** pointer or an [sqlite3] object pointer obtained 326 ** from [sqlite3_open()], [sqlite3_open16()], or 327 ** [sqlite3_open_v2()], and not previously closed. 328 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 329 ** argument is a harmless no-op. 330 */ 331 SQLITE_API int sqlite3_close(sqlite3*); 332 SQLITE_API int sqlite3_close_v2(sqlite3*); 333 334 /* 335 ** The type for a callback function. 336 ** This is legacy and deprecated. It is included for historical 337 ** compatibility and is not documented. 338 */ 339 typedef int (*sqlite3_callback)(void*,int,char**, char**); 340 341 /* 342 ** CAPI3REF: One-Step Query Execution Interface 343 ** METHOD: sqlite3 344 ** 345 ** The sqlite3_exec() interface is a convenience wrapper around 346 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 347 ** that allows an application to run multiple statements of SQL 348 ** without having to use a lot of C code. 349 ** 350 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 351 ** semicolon-separate SQL statements passed into its 2nd argument, 352 ** in the context of the [database connection] passed in as its 1st 353 ** argument. ^If the callback function of the 3rd argument to 354 ** sqlite3_exec() is not NULL, then it is invoked for each result row 355 ** coming out of the evaluated SQL statements. ^The 4th argument to 356 ** sqlite3_exec() is relayed through to the 1st argument of each 357 ** callback invocation. ^If the callback pointer to sqlite3_exec() 358 ** is NULL, then no callback is ever invoked and result rows are 359 ** ignored. 360 ** 361 ** ^If an error occurs while evaluating the SQL statements passed into 362 ** sqlite3_exec(), then execution of the current statement stops and 363 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 364 ** is not NULL then any error message is written into memory obtained 365 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 366 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 367 ** on error message strings returned through the 5th parameter of 368 ** sqlite3_exec() after the error message string is no longer needed. 369 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 370 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 371 ** NULL before returning. 372 ** 373 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 374 ** routine returns SQLITE_ABORT without invoking the callback again and 375 ** without running any subsequent SQL statements. 376 ** 377 ** ^The 2nd argument to the sqlite3_exec() callback function is the 378 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 379 ** callback is an array of pointers to strings obtained as if from 380 ** [sqlite3_column_text()], one for each column. ^If an element of a 381 ** result row is NULL then the corresponding string pointer for the 382 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 383 ** sqlite3_exec() callback is an array of pointers to strings where each 384 ** entry represents the name of corresponding result column as obtained 385 ** from [sqlite3_column_name()]. 386 ** 387 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 388 ** to an empty string, or a pointer that contains only whitespace and/or 389 ** SQL comments, then no SQL statements are evaluated and the database 390 ** is not changed. 391 ** 392 ** Restrictions: 393 ** 394 ** <ul> 395 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 396 ** is a valid and open [database connection]. 397 ** <li> The application must not close the [database connection] specified by 398 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 399 ** <li> The application must not modify the SQL statement text passed into 400 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 401 ** </ul> 402 */ 403 SQLITE_API int sqlite3_exec( 404 sqlite3*, /* An open database */ 405 const char *sql, /* SQL to be evaluated */ 406 int (*callback)(void*,int,char**,char**), /* Callback function */ 407 void *, /* 1st argument to callback */ 408 char **errmsg /* Error msg written here */ 409 ); 410 411 /* 412 ** CAPI3REF: Result Codes 413 ** KEYWORDS: {result code definitions} 414 ** 415 ** Many SQLite functions return an integer result code from the set shown 416 ** here in order to indicate success or failure. 417 ** 418 ** New error codes may be added in future versions of SQLite. 419 ** 420 ** See also: [extended result code definitions] 421 */ 422 #define SQLITE_OK 0 /* Successful result */ 423 /* beginning-of-error-codes */ 424 #define SQLITE_ERROR 1 /* Generic error */ 425 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 426 #define SQLITE_PERM 3 /* Access permission denied */ 427 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 428 #define SQLITE_BUSY 5 /* The database file is locked */ 429 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 430 #define SQLITE_NOMEM 7 /* A malloc() failed */ 431 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 432 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 433 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 434 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 435 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 436 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 437 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 438 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 439 #define SQLITE_EMPTY 16 /* Internal use only */ 440 #define SQLITE_SCHEMA 17 /* The database schema changed */ 441 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 442 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 443 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 444 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 445 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 446 #define SQLITE_AUTH 23 /* Authorization denied */ 447 #define SQLITE_FORMAT 24 /* Not used */ 448 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 449 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 450 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 451 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 452 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 453 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 454 /* end-of-error-codes */ 455 456 /* 457 ** CAPI3REF: Extended Result Codes 458 ** KEYWORDS: {extended result code definitions} 459 ** 460 ** In its default configuration, SQLite API routines return one of 30 integer 461 ** [result codes]. However, experience has shown that many of 462 ** these result codes are too coarse-grained. They do not provide as 463 ** much information about problems as programmers might like. In an effort to 464 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 465 ** and later) include 466 ** support for additional result codes that provide more detailed information 467 ** about errors. These [extended result codes] are enabled or disabled 468 ** on a per database connection basis using the 469 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 470 ** the most recent error can be obtained using 471 ** [sqlite3_extended_errcode()]. 472 */ 473 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 474 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 475 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 476 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 477 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 478 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 479 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 480 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 481 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 482 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 483 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 484 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 485 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 486 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 487 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 488 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 489 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 490 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 491 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 492 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 493 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 494 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 495 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 496 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 497 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 498 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 499 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 500 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 501 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 502 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 503 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 504 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 505 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 506 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 507 #define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8)) 508 #define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8)) 509 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 510 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 511 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 512 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 513 #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8)) 514 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 515 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 516 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 517 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 518 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 519 #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) 520 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 521 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 522 #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8)) 523 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 524 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 525 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 526 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 527 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 528 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 529 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 530 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 531 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 532 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 533 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 534 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 535 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 536 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 537 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 538 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 539 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 540 #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) 541 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 542 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 543 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 544 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 545 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 546 #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) 547 548 /* 549 ** CAPI3REF: Flags For File Open Operations 550 ** 551 ** These bit values are intended for use in the 552 ** 3rd parameter to the [sqlite3_open_v2()] interface and 553 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 554 */ 555 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 556 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 557 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 558 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 559 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 560 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 561 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 562 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 563 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 564 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 565 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 566 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 567 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 568 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 569 #define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */ 570 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 571 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 572 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 573 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 574 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 575 #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ 576 577 /* Reserved: 0x00F00000 */ 578 /* Legacy compatibility: */ 579 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 580 581 582 /* 583 ** CAPI3REF: Device Characteristics 584 ** 585 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 586 ** object returns an integer which is a vector of these 587 ** bit values expressing I/O characteristics of the mass storage 588 ** device that holds the file that the [sqlite3_io_methods] 589 ** refers to. 590 ** 591 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 592 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 593 ** mean that writes of blocks that are nnn bytes in size and 594 ** are aligned to an address which is an integer multiple of 595 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 596 ** that when data is appended to a file, the data is appended 597 ** first then the size of the file is extended, never the other 598 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 599 ** information is written to disk in the same order as calls 600 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 601 ** after reboot following a crash or power loss, the only bytes in a 602 ** file that were written at the application level might have changed 603 ** and that adjacent bytes, even bytes within the same sector are 604 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 605 ** flag indicates that a file cannot be deleted when open. The 606 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 607 ** read-only media and cannot be changed even by processes with 608 ** elevated privileges. 609 ** 610 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 611 ** filesystem supports doing multiple write operations atomically when those 612 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 613 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 614 */ 615 #define SQLITE_IOCAP_ATOMIC 0x00000001 616 #define SQLITE_IOCAP_ATOMIC512 0x00000002 617 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 618 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 619 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 620 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 621 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 622 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 623 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 624 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 625 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 626 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 627 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 628 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 629 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 630 631 /* 632 ** CAPI3REF: File Locking Levels 633 ** 634 ** SQLite uses one of these integer values as the second 635 ** argument to calls it makes to the xLock() and xUnlock() methods 636 ** of an [sqlite3_io_methods] object. 637 */ 638 #define SQLITE_LOCK_NONE 0 639 #define SQLITE_LOCK_SHARED 1 640 #define SQLITE_LOCK_RESERVED 2 641 #define SQLITE_LOCK_PENDING 3 642 #define SQLITE_LOCK_EXCLUSIVE 4 643 644 /* 645 ** CAPI3REF: Synchronization Type Flags 646 ** 647 ** When SQLite invokes the xSync() method of an 648 ** [sqlite3_io_methods] object it uses a combination of 649 ** these integer values as the second argument. 650 ** 651 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 652 ** sync operation only needs to flush data to mass storage. Inode 653 ** information need not be flushed. If the lower four bits of the flag 654 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 655 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 656 ** to use Mac OS X style fullsync instead of fsync(). 657 ** 658 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 659 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 660 ** settings. The [synchronous pragma] determines when calls to the 661 ** xSync VFS method occur and applies uniformly across all platforms. 662 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 663 ** energetic or rigorous or forceful the sync operations are and 664 ** only make a difference on Mac OSX for the default SQLite code. 665 ** (Third-party VFS implementations might also make the distinction 666 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 667 ** operating systems natively supported by SQLite, only Mac OSX 668 ** cares about the difference.) 669 */ 670 #define SQLITE_SYNC_NORMAL 0x00002 671 #define SQLITE_SYNC_FULL 0x00003 672 #define SQLITE_SYNC_DATAONLY 0x00010 673 674 /* 675 ** CAPI3REF: OS Interface Open File Handle 676 ** 677 ** An [sqlite3_file] object represents an open file in the 678 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 679 ** implementations will 680 ** want to subclass this object by appending additional fields 681 ** for their own use. The pMethods entry is a pointer to an 682 ** [sqlite3_io_methods] object that defines methods for performing 683 ** I/O operations on the open file. 684 */ 685 typedef struct sqlite3_file sqlite3_file; 686 struct sqlite3_file { 687 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 688 }; 689 690 /* 691 ** CAPI3REF: OS Interface File Virtual Methods Object 692 ** 693 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 694 ** [sqlite3_file] object (or, more commonly, a subclass of the 695 ** [sqlite3_file] object) with a pointer to an instance of this object. 696 ** This object defines the methods used to perform various operations 697 ** against the open file represented by the [sqlite3_file] object. 698 ** 699 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 700 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 701 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 702 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 703 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 704 ** to NULL. 705 ** 706 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 707 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 708 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 709 ** flag may be ORed in to indicate that only the data of the file 710 ** and not its inode needs to be synced. 711 ** 712 ** The integer values to xLock() and xUnlock() are one of 713 ** <ul> 714 ** <li> [SQLITE_LOCK_NONE], 715 ** <li> [SQLITE_LOCK_SHARED], 716 ** <li> [SQLITE_LOCK_RESERVED], 717 ** <li> [SQLITE_LOCK_PENDING], or 718 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 719 ** </ul> 720 ** xLock() increases the lock. xUnlock() decreases the lock. 721 ** The xCheckReservedLock() method checks whether any database connection, 722 ** either in this process or in some other process, is holding a RESERVED, 723 ** PENDING, or EXCLUSIVE lock on the file. It returns true 724 ** if such a lock exists and false otherwise. 725 ** 726 ** The xFileControl() method is a generic interface that allows custom 727 ** VFS implementations to directly control an open file using the 728 ** [sqlite3_file_control()] interface. The second "op" argument is an 729 ** integer opcode. The third argument is a generic pointer intended to 730 ** point to a structure that may contain arguments or space in which to 731 ** write return values. Potential uses for xFileControl() might be 732 ** functions to enable blocking locks with timeouts, to change the 733 ** locking strategy (for example to use dot-file locks), to inquire 734 ** about the status of a lock, or to break stale locks. The SQLite 735 ** core reserves all opcodes less than 100 for its own use. 736 ** A [file control opcodes | list of opcodes] less than 100 is available. 737 ** Applications that define a custom xFileControl method should use opcodes 738 ** greater than 100 to avoid conflicts. VFS implementations should 739 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 740 ** recognize. 741 ** 742 ** The xSectorSize() method returns the sector size of the 743 ** device that underlies the file. The sector size is the 744 ** minimum write that can be performed without disturbing 745 ** other bytes in the file. The xDeviceCharacteristics() 746 ** method returns a bit vector describing behaviors of the 747 ** underlying device: 748 ** 749 ** <ul> 750 ** <li> [SQLITE_IOCAP_ATOMIC] 751 ** <li> [SQLITE_IOCAP_ATOMIC512] 752 ** <li> [SQLITE_IOCAP_ATOMIC1K] 753 ** <li> [SQLITE_IOCAP_ATOMIC2K] 754 ** <li> [SQLITE_IOCAP_ATOMIC4K] 755 ** <li> [SQLITE_IOCAP_ATOMIC8K] 756 ** <li> [SQLITE_IOCAP_ATOMIC16K] 757 ** <li> [SQLITE_IOCAP_ATOMIC32K] 758 ** <li> [SQLITE_IOCAP_ATOMIC64K] 759 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 760 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 761 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 762 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 763 ** <li> [SQLITE_IOCAP_IMMUTABLE] 764 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 765 ** </ul> 766 ** 767 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 768 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 769 ** mean that writes of blocks that are nnn bytes in size and 770 ** are aligned to an address which is an integer multiple of 771 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 772 ** that when data is appended to a file, the data is appended 773 ** first then the size of the file is extended, never the other 774 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 775 ** information is written to disk in the same order as calls 776 ** to xWrite(). 777 ** 778 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 779 ** in the unread portions of the buffer with zeros. A VFS that 780 ** fails to zero-fill short reads might seem to work. However, 781 ** failure to zero-fill short reads will eventually lead to 782 ** database corruption. 783 */ 784 typedef struct sqlite3_io_methods sqlite3_io_methods; 785 struct sqlite3_io_methods { 786 int iVersion; 787 int (*xClose)(sqlite3_file*); 788 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 789 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 790 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 791 int (*xSync)(sqlite3_file*, int flags); 792 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 793 int (*xLock)(sqlite3_file*, int); 794 int (*xUnlock)(sqlite3_file*, int); 795 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 796 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 797 int (*xSectorSize)(sqlite3_file*); 798 int (*xDeviceCharacteristics)(sqlite3_file*); 799 /* Methods above are valid for version 1 */ 800 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 801 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 802 void (*xShmBarrier)(sqlite3_file*); 803 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 804 /* Methods above are valid for version 2 */ 805 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 806 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 807 /* Methods above are valid for version 3 */ 808 /* Additional methods may be added in future releases */ 809 }; 810 811 /* 812 ** CAPI3REF: Standard File Control Opcodes 813 ** KEYWORDS: {file control opcodes} {file control opcode} 814 ** 815 ** These integer constants are opcodes for the xFileControl method 816 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 817 ** interface. 818 ** 819 ** <ul> 820 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 821 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 822 ** opcode causes the xFileControl method to write the current state of 823 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 824 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 825 ** into an integer that the pArg argument points to. This capability 826 ** is used during testing and is only available when the SQLITE_TEST 827 ** compile-time option is used. 828 ** 829 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 830 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 831 ** layer a hint of how large the database file will grow to be during the 832 ** current transaction. This hint is not guaranteed to be accurate but it 833 ** is often close. The underlying VFS might choose to preallocate database 834 ** file space based on this hint in order to help writes to the database 835 ** file run faster. 836 ** 837 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 838 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 839 ** implements [sqlite3_deserialize()] to set an upper bound on the size 840 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 841 ** If the integer pointed to is negative, then it is filled in with the 842 ** current limit. Otherwise the limit is set to the larger of the value 843 ** of the integer pointed to and the current database size. The integer 844 ** pointed to is set to the new limit. 845 ** 846 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 847 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 848 ** extends and truncates the database file in chunks of a size specified 849 ** by the user. The fourth argument to [sqlite3_file_control()] should 850 ** point to an integer (type int) containing the new chunk-size to use 851 ** for the nominated database. Allocating database file space in large 852 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 853 ** improve performance on some systems. 854 ** 855 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 856 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 857 ** to the [sqlite3_file] object associated with a particular database 858 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 859 ** 860 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 861 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 862 ** to the [sqlite3_file] object associated with the journal file (either 863 ** the [rollback journal] or the [write-ahead log]) for a particular database 864 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 865 ** 866 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 867 ** No longer in use. 868 ** 869 ** <li>[[SQLITE_FCNTL_SYNC]] 870 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 871 ** sent to the VFS immediately before the xSync method is invoked on a 872 ** database file descriptor. Or, if the xSync method is not invoked 873 ** because the user has configured SQLite with 874 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 875 ** of the xSync method. In most cases, the pointer argument passed with 876 ** this file-control is NULL. However, if the database file is being synced 877 ** as part of a multi-database commit, the argument points to a nul-terminated 878 ** string containing the transactions super-journal file name. VFSes that 879 ** do not need this signal should silently ignore this opcode. Applications 880 ** should not call [sqlite3_file_control()] with this opcode as doing so may 881 ** disrupt the operation of the specialized VFSes that do require it. 882 ** 883 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 884 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 885 ** and sent to the VFS after a transaction has been committed immediately 886 ** but before the database is unlocked. VFSes that do not need this signal 887 ** should silently ignore this opcode. Applications should not call 888 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 889 ** operation of the specialized VFSes that do require it. 890 ** 891 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 892 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 893 ** retry counts and intervals for certain disk I/O operations for the 894 ** windows [VFS] in order to provide robustness in the presence of 895 ** anti-virus programs. By default, the windows VFS will retry file read, 896 ** file write, and file delete operations up to 10 times, with a delay 897 ** of 25 milliseconds before the first retry and with the delay increasing 898 ** by an additional 25 milliseconds with each subsequent retry. This 899 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 900 ** to be adjusted. The values are changed for all database connections 901 ** within the same process. The argument is a pointer to an array of two 902 ** integers where the first integer is the new retry count and the second 903 ** integer is the delay. If either integer is negative, then the setting 904 ** is not changed but instead the prior value of that setting is written 905 ** into the array entry, allowing the current retry settings to be 906 ** interrogated. The zDbName parameter is ignored. 907 ** 908 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 909 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 910 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 911 ** write ahead log ([WAL file]) and shared memory 912 ** files used for transaction control 913 ** are automatically deleted when the latest connection to the database 914 ** closes. Setting persistent WAL mode causes those files to persist after 915 ** close. Persisting the files is useful when other processes that do not 916 ** have write permission on the directory containing the database file want 917 ** to read the database file, as the WAL and shared memory files must exist 918 ** in order for the database to be readable. The fourth parameter to 919 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 920 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 921 ** WAL mode. If the integer is -1, then it is overwritten with the current 922 ** WAL persistence setting. 923 ** 924 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 925 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 926 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 927 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 928 ** xDeviceCharacteristics methods. The fourth parameter to 929 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 930 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 931 ** mode. If the integer is -1, then it is overwritten with the current 932 ** zero-damage mode setting. 933 ** 934 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 935 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 936 ** a write transaction to indicate that, unless it is rolled back for some 937 ** reason, the entire database file will be overwritten by the current 938 ** transaction. This is used by VACUUM operations. 939 ** 940 ** <li>[[SQLITE_FCNTL_VFSNAME]] 941 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 942 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 943 ** final bottom-level VFS are written into memory obtained from 944 ** [sqlite3_malloc()] and the result is stored in the char* variable 945 ** that the fourth parameter of [sqlite3_file_control()] points to. 946 ** The caller is responsible for freeing the memory when done. As with 947 ** all file-control actions, there is no guarantee that this will actually 948 ** do anything. Callers should initialize the char* variable to a NULL 949 ** pointer in case this file-control is not implemented. This file-control 950 ** is intended for diagnostic use only. 951 ** 952 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 953 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 954 ** [VFSes] currently in use. ^(The argument X in 955 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 956 ** of type "[sqlite3_vfs] **". This opcodes will set *X 957 ** to a pointer to the top-level VFS.)^ 958 ** ^When there are multiple VFS shims in the stack, this opcode finds the 959 ** upper-most shim only. 960 ** 961 ** <li>[[SQLITE_FCNTL_PRAGMA]] 962 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 963 ** file control is sent to the open [sqlite3_file] object corresponding 964 ** to the database file to which the pragma statement refers. ^The argument 965 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 966 ** pointers to strings (char**) in which the second element of the array 967 ** is the name of the pragma and the third element is the argument to the 968 ** pragma or NULL if the pragma has no argument. ^The handler for an 969 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 970 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 971 ** or the equivalent and that string will become the result of the pragma or 972 ** the error message if the pragma fails. ^If the 973 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 974 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 975 ** file control returns [SQLITE_OK], then the parser assumes that the 976 ** VFS has handled the PRAGMA itself and the parser generates a no-op 977 ** prepared statement if result string is NULL, or that returns a copy 978 ** of the result string if the string is non-NULL. 979 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 980 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 981 ** that the VFS encountered an error while handling the [PRAGMA] and the 982 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 983 ** file control occurs at the beginning of pragma statement analysis and so 984 ** it is able to override built-in [PRAGMA] statements. 985 ** 986 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 987 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 988 ** file-control may be invoked by SQLite on the database file handle 989 ** shortly after it is opened in order to provide a custom VFS with access 990 ** to the connection's busy-handler callback. The argument is of type (void**) 991 ** - an array of two (void *) values. The first (void *) actually points 992 ** to a function of type (int (*)(void *)). In order to invoke the connection's 993 ** busy-handler, this function should be invoked with the second (void *) in 994 ** the array as the only argument. If it returns non-zero, then the operation 995 ** should be retried. If it returns zero, the custom VFS should abandon the 996 ** current operation. 997 ** 998 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 999 ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 1000 ** to have SQLite generate a 1001 ** temporary filename using the same algorithm that is followed to generate 1002 ** temporary filenames for TEMP tables and other internal uses. The 1003 ** argument should be a char** which will be filled with the filename 1004 ** written into memory obtained from [sqlite3_malloc()]. The caller should 1005 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 1006 ** 1007 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1008 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1009 ** maximum number of bytes that will be used for memory-mapped I/O. 1010 ** The argument is a pointer to a value of type sqlite3_int64 that 1011 ** is an advisory maximum number of bytes in the file to memory map. The 1012 ** pointer is overwritten with the old value. The limit is not changed if 1013 ** the value originally pointed to is negative, and so the current limit 1014 ** can be queried by passing in a pointer to a negative number. This 1015 ** file-control is used internally to implement [PRAGMA mmap_size]. 1016 ** 1017 ** <li>[[SQLITE_FCNTL_TRACE]] 1018 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1019 ** to the VFS about what the higher layers of the SQLite stack are doing. 1020 ** This file control is used by some VFS activity tracing [shims]. 1021 ** The argument is a zero-terminated string. Higher layers in the 1022 ** SQLite stack may generate instances of this file control if 1023 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1024 ** 1025 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1026 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1027 ** pointer to an integer and it writes a boolean into that integer depending 1028 ** on whether or not the file has been renamed, moved, or deleted since it 1029 ** was first opened. 1030 ** 1031 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1032 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1033 ** underlying native file handle associated with a file handle. This file 1034 ** control interprets its argument as a pointer to a native file handle and 1035 ** writes the resulting value there. 1036 ** 1037 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1038 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1039 ** opcode causes the xFileControl method to swap the file handle with the one 1040 ** pointed to by the pArg argument. This capability is used during testing 1041 ** and only needs to be supported when SQLITE_TEST is defined. 1042 ** 1043 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1044 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1045 ** be advantageous to block on the next WAL lock if the lock is not immediately 1046 ** available. The WAL subsystem issues this signal during rare 1047 ** circumstances in order to fix a problem with priority inversion. 1048 ** Applications should <em>not</em> use this file-control. 1049 ** 1050 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 1051 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1052 ** VFS should return SQLITE_NOTFOUND for this opcode. 1053 ** 1054 ** <li>[[SQLITE_FCNTL_RBU]] 1055 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1056 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1057 ** this opcode. 1058 ** 1059 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1060 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1061 ** the file descriptor is placed in "batch write mode", which 1062 ** means all subsequent write operations will be deferred and done 1063 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1064 ** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1065 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1066 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1067 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1068 ** no VFS interface calls on the same [sqlite3_file] file descriptor 1069 ** except for calls to the xWrite method and the xFileControl method 1070 ** with [SQLITE_FCNTL_SIZE_HINT]. 1071 ** 1072 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1073 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1074 ** operations since the previous successful call to 1075 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1076 ** This file control returns [SQLITE_OK] if and only if the writes were 1077 ** all performed successfully and have been committed to persistent storage. 1078 ** ^Regardless of whether or not it is successful, this file control takes 1079 ** the file descriptor out of batch write mode so that all subsequent 1080 ** write operations are independent. 1081 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1082 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1083 ** 1084 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1085 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1086 ** operations since the previous successful call to 1087 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1088 ** ^This file control takes the file descriptor out of batch write mode 1089 ** so that all subsequent write operations are independent. 1090 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1091 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1092 ** 1093 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1094 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS 1095 ** to block for up to M milliseconds before failing when attempting to 1096 ** obtain a file lock using the xLock or xShmLock methods of the VFS. 1097 ** The parameter is a pointer to a 32-bit signed integer that contains 1098 ** the value that M is to be set to. Before returning, the 32-bit signed 1099 ** integer is overwritten with the previous value of M. 1100 ** 1101 ** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1102 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1103 ** a database file. The argument is a pointer to a 32-bit unsigned integer. 1104 ** The "data version" for the pager is written into the pointer. The 1105 ** "data version" changes whenever any change occurs to the corresponding 1106 ** database file, either through SQL statements on the same database 1107 ** connection or through transactions committed by separate database 1108 ** connections possibly in other processes. The [sqlite3_total_changes()] 1109 ** interface can be used to find if any database on the connection has changed, 1110 ** but that interface responds to changes on TEMP as well as MAIN and does 1111 ** not provide a mechanism to detect changes to MAIN only. Also, the 1112 ** [sqlite3_total_changes()] interface responds to internal changes only and 1113 ** omits changes made by other database connections. The 1114 ** [PRAGMA data_version] command provides a mechanism to detect changes to 1115 ** a single attached database that occur due to other database connections, 1116 ** but omits changes implemented by the database connection on which it is 1117 ** called. This file control is the only mechanism to detect changes that 1118 ** happen either internally or externally and that are associated with 1119 ** a particular attached database. 1120 ** 1121 ** <li>[[SQLITE_FCNTL_CKPT_START]] 1122 ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint 1123 ** in wal mode before the client starts to copy pages from the wal 1124 ** file to the database file. 1125 ** 1126 ** <li>[[SQLITE_FCNTL_CKPT_DONE]] 1127 ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint 1128 ** in wal mode after the client has finished copying pages from the wal 1129 ** file to the database file, but before the *-shm file is updated to 1130 ** record the fact that the pages have been checkpointed. 1131 ** </ul> 1132 ** 1133 ** <li>[[SQLITE_FCNTL_EXTERNAL_READER]] 1134 ** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect 1135 ** whether or not there is a database client in another process with a wal-mode 1136 ** transaction open on the database or not. It is only available on unix.The 1137 ** (void*) argument passed with this file-control should be a pointer to a 1138 ** value of type (int). The integer value is set to 1 if the database is a wal 1139 ** mode database and there exists at least one client in another process that 1140 ** currently has an SQL transaction open on the database. It is set to 0 if 1141 ** the database is not a wal-mode db, or if there is no such connection in any 1142 ** other process. This opcode cannot be used to detect transactions opened 1143 ** by clients within the current process, only within other processes. 1144 ** </ul> 1145 ** 1146 ** <li>[[SQLITE_FCNTL_CKSM_FILE]] 1147 ** Used by the cksmvfs VFS module only. 1148 ** </ul> 1149 */ 1150 #define SQLITE_FCNTL_LOCKSTATE 1 1151 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1152 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1153 #define SQLITE_FCNTL_LAST_ERRNO 4 1154 #define SQLITE_FCNTL_SIZE_HINT 5 1155 #define SQLITE_FCNTL_CHUNK_SIZE 6 1156 #define SQLITE_FCNTL_FILE_POINTER 7 1157 #define SQLITE_FCNTL_SYNC_OMITTED 8 1158 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1159 #define SQLITE_FCNTL_PERSIST_WAL 10 1160 #define SQLITE_FCNTL_OVERWRITE 11 1161 #define SQLITE_FCNTL_VFSNAME 12 1162 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1163 #define SQLITE_FCNTL_PRAGMA 14 1164 #define SQLITE_FCNTL_BUSYHANDLER 15 1165 #define SQLITE_FCNTL_TEMPFILENAME 16 1166 #define SQLITE_FCNTL_MMAP_SIZE 18 1167 #define SQLITE_FCNTL_TRACE 19 1168 #define SQLITE_FCNTL_HAS_MOVED 20 1169 #define SQLITE_FCNTL_SYNC 21 1170 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1171 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1172 #define SQLITE_FCNTL_WAL_BLOCK 24 1173 #define SQLITE_FCNTL_ZIPVFS 25 1174 #define SQLITE_FCNTL_RBU 26 1175 #define SQLITE_FCNTL_VFS_POINTER 27 1176 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1177 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1178 #define SQLITE_FCNTL_PDB 30 1179 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1180 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1181 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1182 #define SQLITE_FCNTL_LOCK_TIMEOUT 34 1183 #define SQLITE_FCNTL_DATA_VERSION 35 1184 #define SQLITE_FCNTL_SIZE_LIMIT 36 1185 #define SQLITE_FCNTL_CKPT_DONE 37 1186 #define SQLITE_FCNTL_RESERVE_BYTES 38 1187 #define SQLITE_FCNTL_CKPT_START 39 1188 #define SQLITE_FCNTL_EXTERNAL_READER 40 1189 #define SQLITE_FCNTL_CKSM_FILE 41 1190 1191 /* deprecated names */ 1192 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1193 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1194 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1195 1196 1197 /* 1198 ** CAPI3REF: Mutex Handle 1199 ** 1200 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1201 ** abstract type for a mutex object. The SQLite core never looks 1202 ** at the internal representation of an [sqlite3_mutex]. It only 1203 ** deals with pointers to the [sqlite3_mutex] object. 1204 ** 1205 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1206 */ 1207 typedef struct sqlite3_mutex sqlite3_mutex; 1208 1209 /* 1210 ** CAPI3REF: Loadable Extension Thunk 1211 ** 1212 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1213 ** the third parameter to entry points of [loadable extensions]. This 1214 ** structure must be typedefed in order to work around compiler warnings 1215 ** on some platforms. 1216 */ 1217 typedef struct sqlite3_api_routines sqlite3_api_routines; 1218 1219 /* 1220 ** CAPI3REF: OS Interface Object 1221 ** 1222 ** An instance of the sqlite3_vfs object defines the interface between 1223 ** the SQLite core and the underlying operating system. The "vfs" 1224 ** in the name of the object stands for "virtual file system". See 1225 ** the [VFS | VFS documentation] for further information. 1226 ** 1227 ** The VFS interface is sometimes extended by adding new methods onto 1228 ** the end. Each time such an extension occurs, the iVersion field 1229 ** is incremented. The iVersion value started out as 1 in 1230 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1231 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1232 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1233 ** may be appended to the sqlite3_vfs object and the iVersion value 1234 ** may increase again in future versions of SQLite. 1235 ** Note that due to an oversight, the structure 1236 ** of the sqlite3_vfs object changed in the transition from 1237 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1238 ** and yet the iVersion field was not increased. 1239 ** 1240 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1241 ** structure used by this VFS. mxPathname is the maximum length of 1242 ** a pathname in this VFS. 1243 ** 1244 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1245 ** the pNext pointer. The [sqlite3_vfs_register()] 1246 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1247 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1248 ** searches the list. Neither the application code nor the VFS 1249 ** implementation should use the pNext pointer. 1250 ** 1251 ** The pNext field is the only field in the sqlite3_vfs 1252 ** structure that SQLite will ever modify. SQLite will only access 1253 ** or modify this field while holding a particular static mutex. 1254 ** The application should never modify anything within the sqlite3_vfs 1255 ** object once the object has been registered. 1256 ** 1257 ** The zName field holds the name of the VFS module. The name must 1258 ** be unique across all VFS modules. 1259 ** 1260 ** [[sqlite3_vfs.xOpen]] 1261 ** ^SQLite guarantees that the zFilename parameter to xOpen 1262 ** is either a NULL pointer or string obtained 1263 ** from xFullPathname() with an optional suffix added. 1264 ** ^If a suffix is added to the zFilename parameter, it will 1265 ** consist of a single "-" character followed by no more than 1266 ** 11 alphanumeric and/or "-" characters. 1267 ** ^SQLite further guarantees that 1268 ** the string will be valid and unchanged until xClose() is 1269 ** called. Because of the previous sentence, 1270 ** the [sqlite3_file] can safely store a pointer to the 1271 ** filename if it needs to remember the filename for some reason. 1272 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1273 ** must invent its own temporary name for the file. ^Whenever the 1274 ** xFilename parameter is NULL it will also be the case that the 1275 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1276 ** 1277 ** The flags argument to xOpen() includes all bits set in 1278 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1279 ** or [sqlite3_open16()] is used, then flags includes at least 1280 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1281 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1282 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1283 ** 1284 ** ^(SQLite will also add one of the following flags to the xOpen() 1285 ** call, depending on the object being opened: 1286 ** 1287 ** <ul> 1288 ** <li> [SQLITE_OPEN_MAIN_DB] 1289 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1290 ** <li> [SQLITE_OPEN_TEMP_DB] 1291 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1292 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1293 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1294 ** <li> [SQLITE_OPEN_SUPER_JOURNAL] 1295 ** <li> [SQLITE_OPEN_WAL] 1296 ** </ul>)^ 1297 ** 1298 ** The file I/O implementation can use the object type flags to 1299 ** change the way it deals with files. For example, an application 1300 ** that does not care about crash recovery or rollback might make 1301 ** the open of a journal file a no-op. Writes to this journal would 1302 ** also be no-ops, and any attempt to read the journal would return 1303 ** SQLITE_IOERR. Or the implementation might recognize that a database 1304 ** file will be doing page-aligned sector reads and writes in a random 1305 ** order and set up its I/O subsystem accordingly. 1306 ** 1307 ** SQLite might also add one of the following flags to the xOpen method: 1308 ** 1309 ** <ul> 1310 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1311 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1312 ** </ul> 1313 ** 1314 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1315 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1316 ** will be set for TEMP databases and their journals, transient 1317 ** databases, and subjournals. 1318 ** 1319 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1320 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1321 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1322 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1323 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1324 ** be created, and that it is an error if it already exists. 1325 ** It is <i>not</i> used to indicate the file should be opened 1326 ** for exclusive access. 1327 ** 1328 ** ^At least szOsFile bytes of memory are allocated by SQLite 1329 ** to hold the [sqlite3_file] structure passed as the third 1330 ** argument to xOpen. The xOpen method does not have to 1331 ** allocate the structure; it should just fill it in. Note that 1332 ** the xOpen method must set the sqlite3_file.pMethods to either 1333 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1334 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1335 ** element will be valid after xOpen returns regardless of the success 1336 ** or failure of the xOpen call. 1337 ** 1338 ** [[sqlite3_vfs.xAccess]] 1339 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1340 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1341 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1342 ** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1343 ** flag is never actually used and is not implemented in the built-in 1344 ** VFSes of SQLite. The file is named by the second argument and can be a 1345 ** directory. The xAccess method returns [SQLITE_OK] on success or some 1346 ** non-zero error code if there is an I/O error or if the name of 1347 ** the file given in the second argument is illegal. If SQLITE_OK 1348 ** is returned, then non-zero or zero is written into *pResOut to indicate 1349 ** whether or not the file is accessible. 1350 ** 1351 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1352 ** output buffer xFullPathname. The exact size of the output buffer 1353 ** is also passed as a parameter to both methods. If the output buffer 1354 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1355 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1356 ** to prevent this by setting mxPathname to a sufficiently large value. 1357 ** 1358 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1359 ** interfaces are not strictly a part of the filesystem, but they are 1360 ** included in the VFS structure for completeness. 1361 ** The xRandomness() function attempts to return nBytes bytes 1362 ** of good-quality randomness into zOut. The return value is 1363 ** the actual number of bytes of randomness obtained. 1364 ** The xSleep() method causes the calling thread to sleep for at 1365 ** least the number of microseconds given. ^The xCurrentTime() 1366 ** method returns a Julian Day Number for the current date and time as 1367 ** a floating point value. 1368 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1369 ** Day Number multiplied by 86400000 (the number of milliseconds in 1370 ** a 24-hour day). 1371 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1372 ** date and time if that method is available (if iVersion is 2 or 1373 ** greater and the function pointer is not NULL) and will fall back 1374 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1375 ** 1376 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1377 ** are not used by the SQLite core. These optional interfaces are provided 1378 ** by some VFSes to facilitate testing of the VFS code. By overriding 1379 ** system calls with functions under its control, a test program can 1380 ** simulate faults and error conditions that would otherwise be difficult 1381 ** or impossible to induce. The set of system calls that can be overridden 1382 ** varies from one VFS to another, and from one version of the same VFS to the 1383 ** next. Applications that use these interfaces must be prepared for any 1384 ** or all of these interfaces to be NULL or for their behavior to change 1385 ** from one release to the next. Applications must not attempt to access 1386 ** any of these methods if the iVersion of the VFS is less than 3. 1387 */ 1388 typedef struct sqlite3_vfs sqlite3_vfs; 1389 typedef void (*sqlite3_syscall_ptr)(void); 1390 struct sqlite3_vfs { 1391 int iVersion; /* Structure version number (currently 3) */ 1392 int szOsFile; /* Size of subclassed sqlite3_file */ 1393 int mxPathname; /* Maximum file pathname length */ 1394 sqlite3_vfs *pNext; /* Next registered VFS */ 1395 const char *zName; /* Name of this virtual file system */ 1396 void *pAppData; /* Pointer to application-specific data */ 1397 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1398 int flags, int *pOutFlags); 1399 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1400 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1401 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1402 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1403 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1404 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1405 void (*xDlClose)(sqlite3_vfs*, void*); 1406 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1407 int (*xSleep)(sqlite3_vfs*, int microseconds); 1408 int (*xCurrentTime)(sqlite3_vfs*, double*); 1409 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1410 /* 1411 ** The methods above are in version 1 of the sqlite_vfs object 1412 ** definition. Those that follow are added in version 2 or later 1413 */ 1414 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1415 /* 1416 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1417 ** Those below are for version 3 and greater. 1418 */ 1419 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1420 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1421 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1422 /* 1423 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1424 ** New fields may be appended in future versions. The iVersion 1425 ** value will increment whenever this happens. 1426 */ 1427 }; 1428 1429 /* 1430 ** CAPI3REF: Flags for the xAccess VFS method 1431 ** 1432 ** These integer constants can be used as the third parameter to 1433 ** the xAccess method of an [sqlite3_vfs] object. They determine 1434 ** what kind of permissions the xAccess method is looking for. 1435 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1436 ** simply checks whether the file exists. 1437 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1438 ** checks whether the named directory is both readable and writable 1439 ** (in other words, if files can be added, removed, and renamed within 1440 ** the directory). 1441 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1442 ** [temp_store_directory pragma], though this could change in a future 1443 ** release of SQLite. 1444 ** With SQLITE_ACCESS_READ, the xAccess method 1445 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1446 ** currently unused, though it might be used in a future release of 1447 ** SQLite. 1448 */ 1449 #define SQLITE_ACCESS_EXISTS 0 1450 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1451 #define SQLITE_ACCESS_READ 2 /* Unused */ 1452 1453 /* 1454 ** CAPI3REF: Flags for the xShmLock VFS method 1455 ** 1456 ** These integer constants define the various locking operations 1457 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1458 ** following are the only legal combinations of flags to the 1459 ** xShmLock method: 1460 ** 1461 ** <ul> 1462 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1463 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1464 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1465 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1466 ** </ul> 1467 ** 1468 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1469 ** was given on the corresponding lock. 1470 ** 1471 ** The xShmLock method can transition between unlocked and SHARED or 1472 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1473 ** and EXCLUSIVE. 1474 */ 1475 #define SQLITE_SHM_UNLOCK 1 1476 #define SQLITE_SHM_LOCK 2 1477 #define SQLITE_SHM_SHARED 4 1478 #define SQLITE_SHM_EXCLUSIVE 8 1479 1480 /* 1481 ** CAPI3REF: Maximum xShmLock index 1482 ** 1483 ** The xShmLock method on [sqlite3_io_methods] may use values 1484 ** between 0 and this upper bound as its "offset" argument. 1485 ** The SQLite core will never attempt to acquire or release a 1486 ** lock outside of this range 1487 */ 1488 #define SQLITE_SHM_NLOCK 8 1489 1490 1491 /* 1492 ** CAPI3REF: Initialize The SQLite Library 1493 ** 1494 ** ^The sqlite3_initialize() routine initializes the 1495 ** SQLite library. ^The sqlite3_shutdown() routine 1496 ** deallocates any resources that were allocated by sqlite3_initialize(). 1497 ** These routines are designed to aid in process initialization and 1498 ** shutdown on embedded systems. Workstation applications using 1499 ** SQLite normally do not need to invoke either of these routines. 1500 ** 1501 ** A call to sqlite3_initialize() is an "effective" call if it is 1502 ** the first time sqlite3_initialize() is invoked during the lifetime of 1503 ** the process, or if it is the first time sqlite3_initialize() is invoked 1504 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1505 ** of sqlite3_initialize() does any initialization. All other calls 1506 ** are harmless no-ops.)^ 1507 ** 1508 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1509 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1510 ** an effective call to sqlite3_shutdown() does any deinitialization. 1511 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1512 ** 1513 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1514 ** is not. The sqlite3_shutdown() interface must only be called from a 1515 ** single thread. All open [database connections] must be closed and all 1516 ** other SQLite resources must be deallocated prior to invoking 1517 ** sqlite3_shutdown(). 1518 ** 1519 ** Among other things, ^sqlite3_initialize() will invoke 1520 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1521 ** will invoke sqlite3_os_end(). 1522 ** 1523 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1524 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1525 ** the library (perhaps it is unable to allocate a needed resource such 1526 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1527 ** 1528 ** ^The sqlite3_initialize() routine is called internally by many other 1529 ** SQLite interfaces so that an application usually does not need to 1530 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1531 ** calls sqlite3_initialize() so the SQLite library will be automatically 1532 ** initialized when [sqlite3_open()] is called if it has not be initialized 1533 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1534 ** compile-time option, then the automatic calls to sqlite3_initialize() 1535 ** are omitted and the application must call sqlite3_initialize() directly 1536 ** prior to using any other SQLite interface. For maximum portability, 1537 ** it is recommended that applications always invoke sqlite3_initialize() 1538 ** directly prior to using any other SQLite interface. Future releases 1539 ** of SQLite may require this. In other words, the behavior exhibited 1540 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1541 ** default behavior in some future release of SQLite. 1542 ** 1543 ** The sqlite3_os_init() routine does operating-system specific 1544 ** initialization of the SQLite library. The sqlite3_os_end() 1545 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1546 ** performed by these routines include allocation or deallocation 1547 ** of static resources, initialization of global variables, 1548 ** setting up a default [sqlite3_vfs] module, or setting up 1549 ** a default configuration using [sqlite3_config()]. 1550 ** 1551 ** The application should never invoke either sqlite3_os_init() 1552 ** or sqlite3_os_end() directly. The application should only invoke 1553 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1554 ** interface is called automatically by sqlite3_initialize() and 1555 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1556 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1557 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1558 ** When [custom builds | built for other platforms] 1559 ** (using the [SQLITE_OS_OTHER=1] compile-time 1560 ** option) the application must supply a suitable implementation for 1561 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1562 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1563 ** must return [SQLITE_OK] on success and some other [error code] upon 1564 ** failure. 1565 */ 1566 SQLITE_API int sqlite3_initialize(void); 1567 SQLITE_API int sqlite3_shutdown(void); 1568 SQLITE_API int sqlite3_os_init(void); 1569 SQLITE_API int sqlite3_os_end(void); 1570 1571 /* 1572 ** CAPI3REF: Configuring The SQLite Library 1573 ** 1574 ** The sqlite3_config() interface is used to make global configuration 1575 ** changes to SQLite in order to tune SQLite to the specific needs of 1576 ** the application. The default configuration is recommended for most 1577 ** applications and so this routine is usually not necessary. It is 1578 ** provided to support rare applications with unusual needs. 1579 ** 1580 ** <b>The sqlite3_config() interface is not threadsafe. The application 1581 ** must ensure that no other SQLite interfaces are invoked by other 1582 ** threads while sqlite3_config() is running.</b> 1583 ** 1584 ** The sqlite3_config() interface 1585 ** may only be invoked prior to library initialization using 1586 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1587 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1588 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1589 ** Note, however, that ^sqlite3_config() can be called as part of the 1590 ** implementation of an application-defined [sqlite3_os_init()]. 1591 ** 1592 ** The first argument to sqlite3_config() is an integer 1593 ** [configuration option] that determines 1594 ** what property of SQLite is to be configured. Subsequent arguments 1595 ** vary depending on the [configuration option] 1596 ** in the first argument. 1597 ** 1598 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1599 ** ^If the option is unknown or SQLite is unable to set the option 1600 ** then this routine returns a non-zero [error code]. 1601 */ 1602 SQLITE_API int sqlite3_config(int, ...); 1603 1604 /* 1605 ** CAPI3REF: Configure database connections 1606 ** METHOD: sqlite3 1607 ** 1608 ** The sqlite3_db_config() interface is used to make configuration 1609 ** changes to a [database connection]. The interface is similar to 1610 ** [sqlite3_config()] except that the changes apply to a single 1611 ** [database connection] (specified in the first argument). 1612 ** 1613 ** The second argument to sqlite3_db_config(D,V,...) is the 1614 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1615 ** that indicates what aspect of the [database connection] is being configured. 1616 ** Subsequent arguments vary depending on the configuration verb. 1617 ** 1618 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1619 ** the call is considered successful. 1620 */ 1621 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1622 1623 /* 1624 ** CAPI3REF: Memory Allocation Routines 1625 ** 1626 ** An instance of this object defines the interface between SQLite 1627 ** and low-level memory allocation routines. 1628 ** 1629 ** This object is used in only one place in the SQLite interface. 1630 ** A pointer to an instance of this object is the argument to 1631 ** [sqlite3_config()] when the configuration option is 1632 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1633 ** By creating an instance of this object 1634 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1635 ** during configuration, an application can specify an alternative 1636 ** memory allocation subsystem for SQLite to use for all of its 1637 ** dynamic memory needs. 1638 ** 1639 ** Note that SQLite comes with several [built-in memory allocators] 1640 ** that are perfectly adequate for the overwhelming majority of applications 1641 ** and that this object is only useful to a tiny minority of applications 1642 ** with specialized memory allocation requirements. This object is 1643 ** also used during testing of SQLite in order to specify an alternative 1644 ** memory allocator that simulates memory out-of-memory conditions in 1645 ** order to verify that SQLite recovers gracefully from such 1646 ** conditions. 1647 ** 1648 ** The xMalloc, xRealloc, and xFree methods must work like the 1649 ** malloc(), realloc() and free() functions from the standard C library. 1650 ** ^SQLite guarantees that the second argument to 1651 ** xRealloc is always a value returned by a prior call to xRoundup. 1652 ** 1653 ** xSize should return the allocated size of a memory allocation 1654 ** previously obtained from xMalloc or xRealloc. The allocated size 1655 ** is always at least as big as the requested size but may be larger. 1656 ** 1657 ** The xRoundup method returns what would be the allocated size of 1658 ** a memory allocation given a particular requested size. Most memory 1659 ** allocators round up memory allocations at least to the next multiple 1660 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1661 ** Every memory allocation request coming in through [sqlite3_malloc()] 1662 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1663 ** that causes the corresponding memory allocation to fail. 1664 ** 1665 ** The xInit method initializes the memory allocator. For example, 1666 ** it might allocate any required mutexes or initialize internal data 1667 ** structures. The xShutdown method is invoked (indirectly) by 1668 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1669 ** by xInit. The pAppData pointer is used as the only parameter to 1670 ** xInit and xShutdown. 1671 ** 1672 ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes 1673 ** the xInit method, so the xInit method need not be threadsafe. The 1674 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1675 ** not need to be threadsafe either. For all other methods, SQLite 1676 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1677 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1678 ** it is by default) and so the methods are automatically serialized. 1679 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1680 ** methods must be threadsafe or else make their own arrangements for 1681 ** serialization. 1682 ** 1683 ** SQLite will never invoke xInit() more than once without an intervening 1684 ** call to xShutdown(). 1685 */ 1686 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1687 struct sqlite3_mem_methods { 1688 void *(*xMalloc)(int); /* Memory allocation function */ 1689 void (*xFree)(void*); /* Free a prior allocation */ 1690 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1691 int (*xSize)(void*); /* Return the size of an allocation */ 1692 int (*xRoundup)(int); /* Round up request size to allocation size */ 1693 int (*xInit)(void*); /* Initialize the memory allocator */ 1694 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1695 void *pAppData; /* Argument to xInit() and xShutdown() */ 1696 }; 1697 1698 /* 1699 ** CAPI3REF: Configuration Options 1700 ** KEYWORDS: {configuration option} 1701 ** 1702 ** These constants are the available integer configuration options that 1703 ** can be passed as the first argument to the [sqlite3_config()] interface. 1704 ** 1705 ** New configuration options may be added in future releases of SQLite. 1706 ** Existing configuration options might be discontinued. Applications 1707 ** should check the return code from [sqlite3_config()] to make sure that 1708 ** the call worked. The [sqlite3_config()] interface will return a 1709 ** non-zero [error code] if a discontinued or unsupported configuration option 1710 ** is invoked. 1711 ** 1712 ** <dl> 1713 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1714 ** <dd>There are no arguments to this option. ^This option sets the 1715 ** [threading mode] to Single-thread. In other words, it disables 1716 ** all mutexing and puts SQLite into a mode where it can only be used 1717 ** by a single thread. ^If SQLite is compiled with 1718 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1719 ** it is not possible to change the [threading mode] from its default 1720 ** value of Single-thread and so [sqlite3_config()] will return 1721 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1722 ** configuration option.</dd> 1723 ** 1724 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1725 ** <dd>There are no arguments to this option. ^This option sets the 1726 ** [threading mode] to Multi-thread. In other words, it disables 1727 ** mutexing on [database connection] and [prepared statement] objects. 1728 ** The application is responsible for serializing access to 1729 ** [database connections] and [prepared statements]. But other mutexes 1730 ** are enabled so that SQLite will be safe to use in a multi-threaded 1731 ** environment as long as no two threads attempt to use the same 1732 ** [database connection] at the same time. ^If SQLite is compiled with 1733 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1734 ** it is not possible to set the Multi-thread [threading mode] and 1735 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1736 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1737 ** 1738 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1739 ** <dd>There are no arguments to this option. ^This option sets the 1740 ** [threading mode] to Serialized. In other words, this option enables 1741 ** all mutexes including the recursive 1742 ** mutexes on [database connection] and [prepared statement] objects. 1743 ** In this mode (which is the default when SQLite is compiled with 1744 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1745 ** to [database connections] and [prepared statements] so that the 1746 ** application is free to use the same [database connection] or the 1747 ** same [prepared statement] in different threads at the same time. 1748 ** ^If SQLite is compiled with 1749 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1750 ** it is not possible to set the Serialized [threading mode] and 1751 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1752 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1753 ** 1754 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1755 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1756 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1757 ** The argument specifies 1758 ** alternative low-level memory allocation routines to be used in place of 1759 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1760 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1761 ** before the [sqlite3_config()] call returns.</dd> 1762 ** 1763 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1764 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1765 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1766 ** The [sqlite3_mem_methods] 1767 ** structure is filled with the currently defined memory allocation routines.)^ 1768 ** This option can be used to overload the default memory allocation 1769 ** routines with a wrapper that simulations memory allocation failure or 1770 ** tracks memory usage, for example. </dd> 1771 ** 1772 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1773 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1774 ** type int, interpreted as a boolean, which if true provides a hint to 1775 ** SQLite that it should avoid large memory allocations if possible. 1776 ** SQLite will run faster if it is free to make large memory allocations, 1777 ** but some application might prefer to run slower in exchange for 1778 ** guarantees about memory fragmentation that are possible if large 1779 ** allocations are avoided. This hint is normally off. 1780 ** </dd> 1781 ** 1782 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1783 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1784 ** interpreted as a boolean, which enables or disables the collection of 1785 ** memory allocation statistics. ^(When memory allocation statistics are 1786 ** disabled, the following SQLite interfaces become non-operational: 1787 ** <ul> 1788 ** <li> [sqlite3_hard_heap_limit64()] 1789 ** <li> [sqlite3_memory_used()] 1790 ** <li> [sqlite3_memory_highwater()] 1791 ** <li> [sqlite3_soft_heap_limit64()] 1792 ** <li> [sqlite3_status64()] 1793 ** </ul>)^ 1794 ** ^Memory allocation statistics are enabled by default unless SQLite is 1795 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1796 ** allocation statistics are disabled by default. 1797 ** </dd> 1798 ** 1799 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1800 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1801 ** </dd> 1802 ** 1803 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1804 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1805 ** that SQLite can use for the database page cache with the default page 1806 ** cache implementation. 1807 ** This configuration option is a no-op if an application-defined page 1808 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1809 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1810 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1811 ** and the number of cache lines (N). 1812 ** The sz argument should be the size of the largest database page 1813 ** (a power of two between 512 and 65536) plus some extra bytes for each 1814 ** page header. ^The number of extra bytes needed by the page header 1815 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1816 ** ^It is harmless, apart from the wasted memory, 1817 ** for the sz parameter to be larger than necessary. The pMem 1818 ** argument must be either a NULL pointer or a pointer to an 8-byte 1819 ** aligned block of memory of at least sz*N bytes, otherwise 1820 ** subsequent behavior is undefined. 1821 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1822 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1823 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1824 ** is exhausted. 1825 ** ^If pMem is NULL and N is non-zero, then each database connection 1826 ** does an initial bulk allocation for page cache memory 1827 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1828 ** of -1024*N bytes if N is negative, . ^If additional 1829 ** page cache memory is needed beyond what is provided by the initial 1830 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1831 ** additional cache line. </dd> 1832 ** 1833 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1834 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1835 ** that SQLite will use for all of its dynamic memory allocation needs 1836 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1837 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1838 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1839 ** [SQLITE_ERROR] if invoked otherwise. 1840 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1841 ** An 8-byte aligned pointer to the memory, 1842 ** the number of bytes in the memory buffer, and the minimum allocation size. 1843 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1844 ** to using its default memory allocator (the system malloc() implementation), 1845 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1846 ** memory pointer is not NULL then the alternative memory 1847 ** allocator is engaged to handle all of SQLites memory allocation needs. 1848 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1849 ** boundary or subsequent behavior of SQLite will be undefined. 1850 ** The minimum allocation size is capped at 2**12. Reasonable values 1851 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1852 ** 1853 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1854 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1855 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1856 ** The argument specifies alternative low-level mutex routines to be used 1857 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1858 ** the content of the [sqlite3_mutex_methods] structure before the call to 1859 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1860 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1861 ** the entire mutexing subsystem is omitted from the build and hence calls to 1862 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1863 ** return [SQLITE_ERROR].</dd> 1864 ** 1865 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1866 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1867 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1868 ** [sqlite3_mutex_methods] 1869 ** structure is filled with the currently defined mutex routines.)^ 1870 ** This option can be used to overload the default mutex allocation 1871 ** routines with a wrapper used to track mutex usage for performance 1872 ** profiling or testing, for example. ^If SQLite is compiled with 1873 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1874 ** the entire mutexing subsystem is omitted from the build and hence calls to 1875 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1876 ** return [SQLITE_ERROR].</dd> 1877 ** 1878 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1879 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1880 ** the default size of lookaside memory on each [database connection]. 1881 ** The first argument is the 1882 ** size of each lookaside buffer slot and the second is the number of 1883 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1884 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1885 ** option to [sqlite3_db_config()] can be used to change the lookaside 1886 ** configuration on individual connections.)^ </dd> 1887 ** 1888 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1889 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1890 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1891 ** the interface to a custom page cache implementation.)^ 1892 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1893 ** 1894 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1895 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1896 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1897 ** the current page cache implementation into that object.)^ </dd> 1898 ** 1899 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1900 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1901 ** global [error log]. 1902 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1903 ** function with a call signature of void(*)(void*,int,const char*), 1904 ** and a pointer to void. ^If the function pointer is not NULL, it is 1905 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1906 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1907 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1908 ** passed through as the first parameter to the application-defined logger 1909 ** function whenever that function is invoked. ^The second parameter to 1910 ** the logger function is a copy of the first parameter to the corresponding 1911 ** [sqlite3_log()] call and is intended to be a [result code] or an 1912 ** [extended result code]. ^The third parameter passed to the logger is 1913 ** log message after formatting via [sqlite3_snprintf()]. 1914 ** The SQLite logging interface is not reentrant; the logger function 1915 ** supplied by the application must not invoke any SQLite interface. 1916 ** In a multi-threaded application, the application-defined logger 1917 ** function must be threadsafe. </dd> 1918 ** 1919 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1920 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1921 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1922 ** then URI handling is globally disabled.)^ ^If URI handling is globally 1923 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1924 ** [sqlite3_open16()] or 1925 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1926 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1927 ** connection is opened. ^If it is globally disabled, filenames are 1928 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1929 ** database connection is opened. ^(By default, URI handling is globally 1930 ** disabled. The default value may be changed by compiling with the 1931 ** [SQLITE_USE_URI] symbol defined.)^ 1932 ** 1933 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1934 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1935 ** argument which is interpreted as a boolean in order to enable or disable 1936 ** the use of covering indices for full table scans in the query optimizer. 1937 ** ^The default setting is determined 1938 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1939 ** if that compile-time option is omitted. 1940 ** The ability to disable the use of covering indices for full table scans 1941 ** is because some incorrectly coded legacy applications might malfunction 1942 ** when the optimization is enabled. Providing the ability to 1943 ** disable the optimization allows the older, buggy application code to work 1944 ** without change even with newer versions of SQLite. 1945 ** 1946 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1947 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1948 ** <dd> These options are obsolete and should not be used by new code. 1949 ** They are retained for backwards compatibility but are now no-ops. 1950 ** </dd> 1951 ** 1952 ** [[SQLITE_CONFIG_SQLLOG]] 1953 ** <dt>SQLITE_CONFIG_SQLLOG 1954 ** <dd>This option is only available if sqlite is compiled with the 1955 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1956 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1957 ** The second should be of type (void*). The callback is invoked by the library 1958 ** in three separate circumstances, identified by the value passed as the 1959 ** fourth parameter. If the fourth parameter is 0, then the database connection 1960 ** passed as the second argument has just been opened. The third argument 1961 ** points to a buffer containing the name of the main database file. If the 1962 ** fourth parameter is 1, then the SQL statement that the third parameter 1963 ** points to has just been executed. Or, if the fourth parameter is 2, then 1964 ** the connection being passed as the second parameter is being closed. The 1965 ** third parameter is passed NULL In this case. An example of using this 1966 ** configuration option can be seen in the "test_sqllog.c" source file in 1967 ** the canonical SQLite source tree.</dd> 1968 ** 1969 ** [[SQLITE_CONFIG_MMAP_SIZE]] 1970 ** <dt>SQLITE_CONFIG_MMAP_SIZE 1971 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1972 ** that are the default mmap size limit (the default setting for 1973 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1974 ** ^The default setting can be overridden by each database connection using 1975 ** either the [PRAGMA mmap_size] command, or by using the 1976 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1977 ** will be silently truncated if necessary so that it does not exceed the 1978 ** compile-time maximum mmap size set by the 1979 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1980 ** ^If either argument to this option is negative, then that argument is 1981 ** changed to its compile-time default. 1982 ** 1983 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1984 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1985 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1986 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1987 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1988 ** that specifies the maximum size of the created heap. 1989 ** 1990 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1991 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1992 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1993 ** is a pointer to an integer and writes into that integer the number of extra 1994 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1995 ** The amount of extra space required can change depending on the compiler, 1996 ** target platform, and SQLite version. 1997 ** 1998 ** [[SQLITE_CONFIG_PMASZ]] 1999 ** <dt>SQLITE_CONFIG_PMASZ 2000 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 2001 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 2002 ** sorter to that integer. The default minimum PMA Size is set by the 2003 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 2004 ** to help with sort operations when multithreaded sorting 2005 ** is enabled (using the [PRAGMA threads] command) and the amount of content 2006 ** to be sorted exceeds the page size times the minimum of the 2007 ** [PRAGMA cache_size] setting and this value. 2008 ** 2009 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 2010 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 2011 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 2012 ** becomes the [statement journal] spill-to-disk threshold. 2013 ** [Statement journals] are held in memory until their size (in bytes) 2014 ** exceeds this threshold, at which point they are written to disk. 2015 ** Or if the threshold is -1, statement journals are always held 2016 ** exclusively in memory. 2017 ** Since many statement journals never become large, setting the spill 2018 ** threshold to a value such as 64KiB can greatly reduce the amount of 2019 ** I/O required to support statement rollback. 2020 ** The default value for this setting is controlled by the 2021 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 2022 ** 2023 ** [[SQLITE_CONFIG_SORTERREF_SIZE]] 2024 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE 2025 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 2026 ** of type (int) - the new value of the sorter-reference size threshold. 2027 ** Usually, when SQLite uses an external sort to order records according 2028 ** to an ORDER BY clause, all fields required by the caller are present in the 2029 ** sorted records. However, if SQLite determines based on the declared type 2030 ** of a table column that its values are likely to be very large - larger 2031 ** than the configured sorter-reference size threshold - then a reference 2032 ** is stored in each sorted record and the required column values loaded 2033 ** from the database as records are returned in sorted order. The default 2034 ** value for this option is to never use this optimization. Specifying a 2035 ** negative value for this option restores the default behaviour. 2036 ** This option is only available if SQLite is compiled with the 2037 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 2038 ** 2039 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 2040 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 2041 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 2042 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory 2043 ** database created using [sqlite3_deserialize()]. This default maximum 2044 ** size can be adjusted up or down for individual databases using the 2045 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2046 ** configuration setting is never used, then the default maximum is determined 2047 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2048 ** compile-time option is not set, then the default maximum is 1073741824. 2049 ** </dl> 2050 */ 2051 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2052 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2053 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2054 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2055 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2056 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2057 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2058 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2059 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2060 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2061 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2062 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2063 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2064 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2065 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2066 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2067 #define SQLITE_CONFIG_URI 17 /* int */ 2068 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2069 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2070 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2071 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2072 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2073 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2074 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2075 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2076 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2077 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2078 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2079 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2080 2081 /* 2082 ** CAPI3REF: Database Connection Configuration Options 2083 ** 2084 ** These constants are the available integer configuration options that 2085 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 2086 ** 2087 ** New configuration options may be added in future releases of SQLite. 2088 ** Existing configuration options might be discontinued. Applications 2089 ** should check the return code from [sqlite3_db_config()] to make sure that 2090 ** the call worked. ^The [sqlite3_db_config()] interface will return a 2091 ** non-zero [error code] if a discontinued or unsupported configuration option 2092 ** is invoked. 2093 ** 2094 ** <dl> 2095 ** [[SQLITE_DBCONFIG_LOOKASIDE]] 2096 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2097 ** <dd> ^This option takes three additional arguments that determine the 2098 ** [lookaside memory allocator] configuration for the [database connection]. 2099 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2100 ** pointer to a memory buffer to use for lookaside memory. 2101 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2102 ** may be NULL in which case SQLite will allocate the 2103 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2104 ** size of each lookaside buffer slot. ^The third argument is the number of 2105 ** slots. The size of the buffer in the first argument must be greater than 2106 ** or equal to the product of the second and third arguments. The buffer 2107 ** must be aligned to an 8-byte boundary. ^If the second argument to 2108 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2109 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2110 ** configuration for a database connection can only be changed when that 2111 ** connection is not currently using lookaside memory, or in other words 2112 ** when the "current value" returned by 2113 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2114 ** Any attempt to change the lookaside memory configuration when lookaside 2115 ** memory is in use leaves the configuration unchanged and returns 2116 ** [SQLITE_BUSY].)^</dd> 2117 ** 2118 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2119 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2120 ** <dd> ^This option is used to enable or disable the enforcement of 2121 ** [foreign key constraints]. There should be two additional arguments. 2122 ** The first argument is an integer which is 0 to disable FK enforcement, 2123 ** positive to enable FK enforcement or negative to leave FK enforcement 2124 ** unchanged. The second parameter is a pointer to an integer into which 2125 ** is written 0 or 1 to indicate whether FK enforcement is off or on 2126 ** following this call. The second parameter may be a NULL pointer, in 2127 ** which case the FK enforcement setting is not reported back. </dd> 2128 ** 2129 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2130 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2131 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2132 ** There should be two additional arguments. 2133 ** The first argument is an integer which is 0 to disable triggers, 2134 ** positive to enable triggers or negative to leave the setting unchanged. 2135 ** The second parameter is a pointer to an integer into which 2136 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 2137 ** following this call. The second parameter may be a NULL pointer, in 2138 ** which case the trigger setting is not reported back. 2139 ** 2140 ** <p>Originally this option disabled all triggers. ^(However, since 2141 ** SQLite version 3.35.0, TEMP triggers are still allowed even if 2142 ** this option is off. So, in other words, this option now only disables 2143 ** triggers in the main database schema or in the schemas of ATTACH-ed 2144 ** databases.)^ </dd> 2145 ** 2146 ** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2147 ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2148 ** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2149 ** There should be two additional arguments. 2150 ** The first argument is an integer which is 0 to disable views, 2151 ** positive to enable views or negative to leave the setting unchanged. 2152 ** The second parameter is a pointer to an integer into which 2153 ** is written 0 or 1 to indicate whether views are disabled or enabled 2154 ** following this call. The second parameter may be a NULL pointer, in 2155 ** which case the view setting is not reported back. 2156 ** 2157 ** <p>Originally this option disabled all views. ^(However, since 2158 ** SQLite version 3.35.0, TEMP views are still allowed even if 2159 ** this option is off. So, in other words, this option now only disables 2160 ** views in the main database schema or in the schemas of ATTACH-ed 2161 ** databases.)^ </dd> 2162 ** 2163 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2164 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2165 ** <dd> ^This option is used to enable or disable the 2166 ** [fts3_tokenizer()] function which is part of the 2167 ** [FTS3] full-text search engine extension. 2168 ** There should be two additional arguments. 2169 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2170 ** positive to enable fts3_tokenizer() or negative to leave the setting 2171 ** unchanged. 2172 ** The second parameter is a pointer to an integer into which 2173 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2174 ** following this call. The second parameter may be a NULL pointer, in 2175 ** which case the new setting is not reported back. </dd> 2176 ** 2177 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2178 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2179 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2180 ** interface independently of the [load_extension()] SQL function. 2181 ** The [sqlite3_enable_load_extension()] API enables or disables both the 2182 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2183 ** There should be two additional arguments. 2184 ** When the first argument to this interface is 1, then only the C-API is 2185 ** enabled and the SQL function remains disabled. If the first argument to 2186 ** this interface is 0, then both the C-API and the SQL function are disabled. 2187 ** If the first argument is -1, then no changes are made to state of either the 2188 ** C-API or the SQL function. 2189 ** The second parameter is a pointer to an integer into which 2190 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2191 ** is disabled or enabled following this call. The second parameter may 2192 ** be a NULL pointer, in which case the new setting is not reported back. 2193 ** </dd> 2194 ** 2195 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2196 ** <dd> ^This option is used to change the name of the "main" database 2197 ** schema. ^The sole argument is a pointer to a constant UTF8 string 2198 ** which will become the new schema name in place of "main". ^SQLite 2199 ** does not make a copy of the new main schema name string, so the application 2200 ** must ensure that the argument passed into this DBCONFIG option is unchanged 2201 ** until after the database connection closes. 2202 ** </dd> 2203 ** 2204 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2205 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2206 ** <dd> Usually, when a database in wal mode is closed or detached from a 2207 ** database handle, SQLite checks if this will mean that there are now no 2208 ** connections at all to the database. If so, it performs a checkpoint 2209 ** operation before closing the connection. This option may be used to 2210 ** override this behaviour. The first parameter passed to this operation 2211 ** is an integer - positive to disable checkpoints-on-close, or zero (the 2212 ** default) to enable them, and negative to leave the setting unchanged. 2213 ** The second parameter is a pointer to an integer 2214 ** into which is written 0 or 1 to indicate whether checkpoints-on-close 2215 ** have been disabled - 0 if they are not disabled, 1 if they are. 2216 ** </dd> 2217 ** 2218 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2219 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2220 ** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2221 ** a single SQL query statement will always use the same algorithm regardless 2222 ** of values of [bound parameters].)^ The QPSG disables some query optimizations 2223 ** that look at the values of bound parameters, which can make some queries 2224 ** slower. But the QPSG has the advantage of more predictable behavior. With 2225 ** the QPSG active, SQLite will always use the same query plan in the field as 2226 ** was used during testing in the lab. 2227 ** The first argument to this setting is an integer which is 0 to disable 2228 ** the QPSG, positive to enable QPSG, or negative to leave the setting 2229 ** unchanged. The second parameter is a pointer to an integer into which 2230 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2231 ** following this call. 2232 ** </dd> 2233 ** 2234 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2235 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2236 ** include output for any operations performed by trigger programs. This 2237 ** option is used to set or clear (the default) a flag that governs this 2238 ** behavior. The first parameter passed to this operation is an integer - 2239 ** positive to enable output for trigger programs, or zero to disable it, 2240 ** or negative to leave the setting unchanged. 2241 ** The second parameter is a pointer to an integer into which is written 2242 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2243 ** it is not disabled, 1 if it is. 2244 ** </dd> 2245 ** 2246 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2247 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2248 ** [VACUUM] in order to reset a database back to an empty database 2249 ** with no schema and no content. The following process works even for 2250 ** a badly corrupted database file: 2251 ** <ol> 2252 ** <li> If the database connection is newly opened, make sure it has read the 2253 ** database schema by preparing then discarding some query against the 2254 ** database, or calling sqlite3_table_column_metadata(), ignoring any 2255 ** errors. This step is only necessary if the application desires to keep 2256 ** the database in WAL mode after the reset if it was in WAL mode before 2257 ** the reset. 2258 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2259 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2260 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2261 ** </ol> 2262 ** Because resetting a database is destructive and irreversible, the 2263 ** process requires the use of this obscure API and multiple steps to help 2264 ** ensure that it does not happen by accident. 2265 ** 2266 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2267 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2268 ** "defensive" flag for a database connection. When the defensive 2269 ** flag is enabled, language features that allow ordinary SQL to 2270 ** deliberately corrupt the database file are disabled. The disabled 2271 ** features include but are not limited to the following: 2272 ** <ul> 2273 ** <li> The [PRAGMA writable_schema=ON] statement. 2274 ** <li> The [PRAGMA journal_mode=OFF] statement. 2275 ** <li> Writes to the [sqlite_dbpage] virtual table. 2276 ** <li> Direct writes to [shadow tables]. 2277 ** </ul> 2278 ** </dd> 2279 ** 2280 ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2281 ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2282 ** "writable_schema" flag. This has the same effect and is logically equivalent 2283 ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2284 ** The first argument to this setting is an integer which is 0 to disable 2285 ** the writable_schema, positive to enable writable_schema, or negative to 2286 ** leave the setting unchanged. The second parameter is a pointer to an 2287 ** integer into which is written 0 or 1 to indicate whether the writable_schema 2288 ** is enabled or disabled following this call. 2289 ** </dd> 2290 ** 2291 ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2292 ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2293 ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2294 ** the legacy behavior of the [ALTER TABLE RENAME] command such it 2295 ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2296 ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2297 ** additional information. This feature can also be turned on and off 2298 ** using the [PRAGMA legacy_alter_table] statement. 2299 ** </dd> 2300 ** 2301 ** [[SQLITE_DBCONFIG_DQS_DML]] 2302 ** <dt>SQLITE_DBCONFIG_DQS_DML</td> 2303 ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2304 ** the legacy [double-quoted string literal] misfeature for DML statements 2305 ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2306 ** default value of this setting is determined by the [-DSQLITE_DQS] 2307 ** compile-time option. 2308 ** </dd> 2309 ** 2310 ** [[SQLITE_DBCONFIG_DQS_DDL]] 2311 ** <dt>SQLITE_DBCONFIG_DQS_DDL</td> 2312 ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2313 ** the legacy [double-quoted string literal] misfeature for DDL statements, 2314 ** such as CREATE TABLE and CREATE INDEX. The 2315 ** default value of this setting is determined by the [-DSQLITE_DQS] 2316 ** compile-time option. 2317 ** </dd> 2318 ** 2319 ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] 2320 ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td> 2321 ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to 2322 ** assume that database schemas are untainted by malicious content. 2323 ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite 2324 ** takes additional defensive steps to protect the application from harm 2325 ** including: 2326 ** <ul> 2327 ** <li> Prohibit the use of SQL functions inside triggers, views, 2328 ** CHECK constraints, DEFAULT clauses, expression indexes, 2329 ** partial indexes, or generated columns 2330 ** unless those functions are tagged with [SQLITE_INNOCUOUS]. 2331 ** <li> Prohibit the use of virtual tables inside of triggers or views 2332 ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. 2333 ** </ul> 2334 ** This setting defaults to "on" for legacy compatibility, however 2335 ** all applications are advised to turn it off if possible. This setting 2336 ** can also be controlled using the [PRAGMA trusted_schema] statement. 2337 ** </dd> 2338 ** 2339 ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] 2340 ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td> 2341 ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates 2342 ** the legacy file format flag. When activated, this flag causes all newly 2343 ** created database file to have a schema format version number (the 4-byte 2344 ** integer found at offset 44 into the database header) of 1. This in turn 2345 ** means that the resulting database file will be readable and writable by 2346 ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, 2347 ** newly created databases are generally not understandable by SQLite versions 2348 ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there 2349 ** is now scarcely any need to generated database files that are compatible 2350 ** all the way back to version 3.0.0, and so this setting is of little 2351 ** practical use, but is provided so that SQLite can continue to claim the 2352 ** ability to generate new database files that are compatible with version 2353 ** 3.0.0. 2354 ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, 2355 ** the [VACUUM] command will fail with an obscure error when attempting to 2356 ** process a table with generated columns and a descending index. This is 2357 ** not considered a bug since SQLite versions 3.3.0 and earlier do not support 2358 ** either generated columns or decending indexes. 2359 ** </dd> 2360 ** </dl> 2361 */ 2362 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2363 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2364 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2365 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2366 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2367 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2368 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2369 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2370 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2371 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2372 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2373 #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2374 #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2375 #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2376 #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2377 #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2378 #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ 2379 #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ 2380 #define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */ 2381 2382 /* 2383 ** CAPI3REF: Enable Or Disable Extended Result Codes 2384 ** METHOD: sqlite3 2385 ** 2386 ** ^The sqlite3_extended_result_codes() routine enables or disables the 2387 ** [extended result codes] feature of SQLite. ^The extended result 2388 ** codes are disabled by default for historical compatibility. 2389 */ 2390 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2391 2392 /* 2393 ** CAPI3REF: Last Insert Rowid 2394 ** METHOD: sqlite3 2395 ** 2396 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2397 ** has a unique 64-bit signed 2398 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2399 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2400 ** names are not also used by explicitly declared columns. ^If 2401 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2402 ** is another alias for the rowid. 2403 ** 2404 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2405 ** the most recent successful [INSERT] into a rowid table or [virtual table] 2406 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2407 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2408 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2409 ** zero. 2410 ** 2411 ** As well as being set automatically as rows are inserted into database 2412 ** tables, the value returned by this function may be set explicitly by 2413 ** [sqlite3_set_last_insert_rowid()] 2414 ** 2415 ** Some virtual table implementations may INSERT rows into rowid tables as 2416 ** part of committing a transaction (e.g. to flush data accumulated in memory 2417 ** to disk). In this case subsequent calls to this function return the rowid 2418 ** associated with these internal INSERT operations, which leads to 2419 ** unintuitive results. Virtual table implementations that do write to rowid 2420 ** tables in this way can avoid this problem by restoring the original 2421 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2422 ** control to the user. 2423 ** 2424 ** ^(If an [INSERT] occurs within a trigger then this routine will 2425 ** return the [rowid] of the inserted row as long as the trigger is 2426 ** running. Once the trigger program ends, the value returned 2427 ** by this routine reverts to what it was before the trigger was fired.)^ 2428 ** 2429 ** ^An [INSERT] that fails due to a constraint violation is not a 2430 ** successful [INSERT] and does not change the value returned by this 2431 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2432 ** and INSERT OR ABORT make no changes to the return value of this 2433 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2434 ** encounters a constraint violation, it does not fail. The 2435 ** INSERT continues to completion after deleting rows that caused 2436 ** the constraint problem so INSERT OR REPLACE will always change 2437 ** the return value of this interface.)^ 2438 ** 2439 ** ^For the purposes of this routine, an [INSERT] is considered to 2440 ** be successful even if it is subsequently rolled back. 2441 ** 2442 ** This function is accessible to SQL statements via the 2443 ** [last_insert_rowid() SQL function]. 2444 ** 2445 ** If a separate thread performs a new [INSERT] on the same 2446 ** database connection while the [sqlite3_last_insert_rowid()] 2447 ** function is running and thus changes the last insert [rowid], 2448 ** then the value returned by [sqlite3_last_insert_rowid()] is 2449 ** unpredictable and might not equal either the old or the new 2450 ** last insert [rowid]. 2451 */ 2452 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2453 2454 /* 2455 ** CAPI3REF: Set the Last Insert Rowid value. 2456 ** METHOD: sqlite3 2457 ** 2458 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2459 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2460 ** without inserting a row into the database. 2461 */ 2462 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2463 2464 /* 2465 ** CAPI3REF: Count The Number Of Rows Modified 2466 ** METHOD: sqlite3 2467 ** 2468 ** ^This function returns the number of rows modified, inserted or 2469 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2470 ** statement on the database connection specified by the only parameter. 2471 ** ^Executing any other type of SQL statement does not modify the value 2472 ** returned by this function. 2473 ** 2474 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2475 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2476 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2477 ** 2478 ** Changes to a view that are intercepted by 2479 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2480 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2481 ** DELETE statement run on a view is always zero. Only changes made to real 2482 ** tables are counted. 2483 ** 2484 ** Things are more complicated if the sqlite3_changes() function is 2485 ** executed while a trigger program is running. This may happen if the 2486 ** program uses the [changes() SQL function], or if some other callback 2487 ** function invokes sqlite3_changes() directly. Essentially: 2488 ** 2489 ** <ul> 2490 ** <li> ^(Before entering a trigger program the value returned by 2491 ** sqlite3_changes() function is saved. After the trigger program 2492 ** has finished, the original value is restored.)^ 2493 ** 2494 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2495 ** statement sets the value returned by sqlite3_changes() 2496 ** upon completion as normal. Of course, this value will not include 2497 ** any changes performed by sub-triggers, as the sqlite3_changes() 2498 ** value will be saved and restored after each sub-trigger has run.)^ 2499 ** </ul> 2500 ** 2501 ** ^This means that if the changes() SQL function (or similar) is used 2502 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2503 ** returns the value as set when the calling statement began executing. 2504 ** ^If it is used by the second or subsequent such statement within a trigger 2505 ** program, the value returned reflects the number of rows modified by the 2506 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2507 ** 2508 ** If a separate thread makes changes on the same database connection 2509 ** while [sqlite3_changes()] is running then the value returned 2510 ** is unpredictable and not meaningful. 2511 ** 2512 ** See also: 2513 ** <ul> 2514 ** <li> the [sqlite3_total_changes()] interface 2515 ** <li> the [count_changes pragma] 2516 ** <li> the [changes() SQL function] 2517 ** <li> the [data_version pragma] 2518 ** </ul> 2519 */ 2520 SQLITE_API int sqlite3_changes(sqlite3*); 2521 2522 /* 2523 ** CAPI3REF: Total Number Of Rows Modified 2524 ** METHOD: sqlite3 2525 ** 2526 ** ^This function returns the total number of rows inserted, modified or 2527 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2528 ** since the database connection was opened, including those executed as 2529 ** part of trigger programs. ^Executing any other type of SQL statement 2530 ** does not affect the value returned by sqlite3_total_changes(). 2531 ** 2532 ** ^Changes made as part of [foreign key actions] are included in the 2533 ** count, but those made as part of REPLACE constraint resolution are 2534 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2535 ** are not counted. 2536 ** 2537 ** The [sqlite3_total_changes(D)] interface only reports the number 2538 ** of rows that changed due to SQL statement run against database 2539 ** connection D. Any changes by other database connections are ignored. 2540 ** To detect changes against a database file from other database 2541 ** connections use the [PRAGMA data_version] command or the 2542 ** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2543 ** 2544 ** If a separate thread makes changes on the same database connection 2545 ** while [sqlite3_total_changes()] is running then the value 2546 ** returned is unpredictable and not meaningful. 2547 ** 2548 ** See also: 2549 ** <ul> 2550 ** <li> the [sqlite3_changes()] interface 2551 ** <li> the [count_changes pragma] 2552 ** <li> the [changes() SQL function] 2553 ** <li> the [data_version pragma] 2554 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2555 ** </ul> 2556 */ 2557 SQLITE_API int sqlite3_total_changes(sqlite3*); 2558 2559 /* 2560 ** CAPI3REF: Interrupt A Long-Running Query 2561 ** METHOD: sqlite3 2562 ** 2563 ** ^This function causes any pending database operation to abort and 2564 ** return at its earliest opportunity. This routine is typically 2565 ** called in response to a user action such as pressing "Cancel" 2566 ** or Ctrl-C where the user wants a long query operation to halt 2567 ** immediately. 2568 ** 2569 ** ^It is safe to call this routine from a thread different from the 2570 ** thread that is currently running the database operation. But it 2571 ** is not safe to call this routine with a [database connection] that 2572 ** is closed or might close before sqlite3_interrupt() returns. 2573 ** 2574 ** ^If an SQL operation is very nearly finished at the time when 2575 ** sqlite3_interrupt() is called, then it might not have an opportunity 2576 ** to be interrupted and might continue to completion. 2577 ** 2578 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2579 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2580 ** that is inside an explicit transaction, then the entire transaction 2581 ** will be rolled back automatically. 2582 ** 2583 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2584 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2585 ** that are started after the sqlite3_interrupt() call and before the 2586 ** running statement count reaches zero are interrupted as if they had been 2587 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2588 ** that are started after the running statement count reaches zero are 2589 ** not effected by the sqlite3_interrupt(). 2590 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2591 ** SQL statements is a no-op and has no effect on SQL statements 2592 ** that are started after the sqlite3_interrupt() call returns. 2593 */ 2594 SQLITE_API void sqlite3_interrupt(sqlite3*); 2595 2596 /* 2597 ** CAPI3REF: Determine If An SQL Statement Is Complete 2598 ** 2599 ** These routines are useful during command-line input to determine if the 2600 ** currently entered text seems to form a complete SQL statement or 2601 ** if additional input is needed before sending the text into 2602 ** SQLite for parsing. ^These routines return 1 if the input string 2603 ** appears to be a complete SQL statement. ^A statement is judged to be 2604 ** complete if it ends with a semicolon token and is not a prefix of a 2605 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2606 ** string literals or quoted identifier names or comments are not 2607 ** independent tokens (they are part of the token in which they are 2608 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2609 ** and comments that follow the final semicolon are ignored. 2610 ** 2611 ** ^These routines return 0 if the statement is incomplete. ^If a 2612 ** memory allocation fails, then SQLITE_NOMEM is returned. 2613 ** 2614 ** ^These routines do not parse the SQL statements thus 2615 ** will not detect syntactically incorrect SQL. 2616 ** 2617 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2618 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2619 ** automatically by sqlite3_complete16(). If that initialization fails, 2620 ** then the return value from sqlite3_complete16() will be non-zero 2621 ** regardless of whether or not the input SQL is complete.)^ 2622 ** 2623 ** The input to [sqlite3_complete()] must be a zero-terminated 2624 ** UTF-8 string. 2625 ** 2626 ** The input to [sqlite3_complete16()] must be a zero-terminated 2627 ** UTF-16 string in native byte order. 2628 */ 2629 SQLITE_API int sqlite3_complete(const char *sql); 2630 SQLITE_API int sqlite3_complete16(const void *sql); 2631 2632 /* 2633 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2634 ** KEYWORDS: {busy-handler callback} {busy handler} 2635 ** METHOD: sqlite3 2636 ** 2637 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2638 ** that might be invoked with argument P whenever 2639 ** an attempt is made to access a database table associated with 2640 ** [database connection] D when another thread 2641 ** or process has the table locked. 2642 ** The sqlite3_busy_handler() interface is used to implement 2643 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2644 ** 2645 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2646 ** is returned immediately upon encountering the lock. ^If the busy callback 2647 ** is not NULL, then the callback might be invoked with two arguments. 2648 ** 2649 ** ^The first argument to the busy handler is a copy of the void* pointer which 2650 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2651 ** the busy handler callback is the number of times that the busy handler has 2652 ** been invoked previously for the same locking event. ^If the 2653 ** busy callback returns 0, then no additional attempts are made to 2654 ** access the database and [SQLITE_BUSY] is returned 2655 ** to the application. 2656 ** ^If the callback returns non-zero, then another attempt 2657 ** is made to access the database and the cycle repeats. 2658 ** 2659 ** The presence of a busy handler does not guarantee that it will be invoked 2660 ** when there is lock contention. ^If SQLite determines that invoking the busy 2661 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2662 ** to the application instead of invoking the 2663 ** busy handler. 2664 ** Consider a scenario where one process is holding a read lock that 2665 ** it is trying to promote to a reserved lock and 2666 ** a second process is holding a reserved lock that it is trying 2667 ** to promote to an exclusive lock. The first process cannot proceed 2668 ** because it is blocked by the second and the second process cannot 2669 ** proceed because it is blocked by the first. If both processes 2670 ** invoke the busy handlers, neither will make any progress. Therefore, 2671 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2672 ** will induce the first process to release its read lock and allow 2673 ** the second process to proceed. 2674 ** 2675 ** ^The default busy callback is NULL. 2676 ** 2677 ** ^(There can only be a single busy handler defined for each 2678 ** [database connection]. Setting a new busy handler clears any 2679 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2680 ** or evaluating [PRAGMA busy_timeout=N] will change the 2681 ** busy handler and thus clear any previously set busy handler. 2682 ** 2683 ** The busy callback should not take any actions which modify the 2684 ** database connection that invoked the busy handler. In other words, 2685 ** the busy handler is not reentrant. Any such actions 2686 ** result in undefined behavior. 2687 ** 2688 ** A busy handler must not close the database connection 2689 ** or [prepared statement] that invoked the busy handler. 2690 */ 2691 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2692 2693 /* 2694 ** CAPI3REF: Set A Busy Timeout 2695 ** METHOD: sqlite3 2696 ** 2697 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2698 ** for a specified amount of time when a table is locked. ^The handler 2699 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2700 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2701 ** the handler returns 0 which causes [sqlite3_step()] to return 2702 ** [SQLITE_BUSY]. 2703 ** 2704 ** ^Calling this routine with an argument less than or equal to zero 2705 ** turns off all busy handlers. 2706 ** 2707 ** ^(There can only be a single busy handler for a particular 2708 ** [database connection] at any given moment. If another busy handler 2709 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2710 ** this routine, that other busy handler is cleared.)^ 2711 ** 2712 ** See also: [PRAGMA busy_timeout] 2713 */ 2714 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2715 2716 /* 2717 ** CAPI3REF: Convenience Routines For Running Queries 2718 ** METHOD: sqlite3 2719 ** 2720 ** This is a legacy interface that is preserved for backwards compatibility. 2721 ** Use of this interface is not recommended. 2722 ** 2723 ** Definition: A <b>result table</b> is memory data structure created by the 2724 ** [sqlite3_get_table()] interface. A result table records the 2725 ** complete query results from one or more queries. 2726 ** 2727 ** The table conceptually has a number of rows and columns. But 2728 ** these numbers are not part of the result table itself. These 2729 ** numbers are obtained separately. Let N be the number of rows 2730 ** and M be the number of columns. 2731 ** 2732 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2733 ** There are (N+1)*M elements in the array. The first M pointers point 2734 ** to zero-terminated strings that contain the names of the columns. 2735 ** The remaining entries all point to query results. NULL values result 2736 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2737 ** string representation as returned by [sqlite3_column_text()]. 2738 ** 2739 ** A result table might consist of one or more memory allocations. 2740 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2741 ** A result table should be deallocated using [sqlite3_free_table()]. 2742 ** 2743 ** ^(As an example of the result table format, suppose a query result 2744 ** is as follows: 2745 ** 2746 ** <blockquote><pre> 2747 ** Name | Age 2748 ** ----------------------- 2749 ** Alice | 43 2750 ** Bob | 28 2751 ** Cindy | 21 2752 ** </pre></blockquote> 2753 ** 2754 ** There are two columns (M==2) and three rows (N==3). Thus the 2755 ** result table has 8 entries. Suppose the result table is stored 2756 ** in an array named azResult. Then azResult holds this content: 2757 ** 2758 ** <blockquote><pre> 2759 ** azResult[0] = "Name"; 2760 ** azResult[1] = "Age"; 2761 ** azResult[2] = "Alice"; 2762 ** azResult[3] = "43"; 2763 ** azResult[4] = "Bob"; 2764 ** azResult[5] = "28"; 2765 ** azResult[6] = "Cindy"; 2766 ** azResult[7] = "21"; 2767 ** </pre></blockquote>)^ 2768 ** 2769 ** ^The sqlite3_get_table() function evaluates one or more 2770 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2771 ** string of its 2nd parameter and returns a result table to the 2772 ** pointer given in its 3rd parameter. 2773 ** 2774 ** After the application has finished with the result from sqlite3_get_table(), 2775 ** it must pass the result table pointer to sqlite3_free_table() in order to 2776 ** release the memory that was malloced. Because of the way the 2777 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2778 ** function must not try to call [sqlite3_free()] directly. Only 2779 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2780 ** 2781 ** The sqlite3_get_table() interface is implemented as a wrapper around 2782 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2783 ** to any internal data structures of SQLite. It uses only the public 2784 ** interface defined here. As a consequence, errors that occur in the 2785 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2786 ** reflected in subsequent calls to [sqlite3_errcode()] or 2787 ** [sqlite3_errmsg()]. 2788 */ 2789 SQLITE_API int sqlite3_get_table( 2790 sqlite3 *db, /* An open database */ 2791 const char *zSql, /* SQL to be evaluated */ 2792 char ***pazResult, /* Results of the query */ 2793 int *pnRow, /* Number of result rows written here */ 2794 int *pnColumn, /* Number of result columns written here */ 2795 char **pzErrmsg /* Error msg written here */ 2796 ); 2797 SQLITE_API void sqlite3_free_table(char **result); 2798 2799 /* 2800 ** CAPI3REF: Formatted String Printing Functions 2801 ** 2802 ** These routines are work-alikes of the "printf()" family of functions 2803 ** from the standard C library. 2804 ** These routines understand most of the common formatting options from 2805 ** the standard library printf() 2806 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2807 ** See the [built-in printf()] documentation for details. 2808 ** 2809 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2810 ** results into memory obtained from [sqlite3_malloc64()]. 2811 ** The strings returned by these two routines should be 2812 ** released by [sqlite3_free()]. ^Both routines return a 2813 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2814 ** memory to hold the resulting string. 2815 ** 2816 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2817 ** the standard C library. The result is written into the 2818 ** buffer supplied as the second parameter whose size is given by 2819 ** the first parameter. Note that the order of the 2820 ** first two parameters is reversed from snprintf().)^ This is an 2821 ** historical accident that cannot be fixed without breaking 2822 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2823 ** returns a pointer to its buffer instead of the number of 2824 ** characters actually written into the buffer.)^ We admit that 2825 ** the number of characters written would be a more useful return 2826 ** value but we cannot change the implementation of sqlite3_snprintf() 2827 ** now without breaking compatibility. 2828 ** 2829 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2830 ** guarantees that the buffer is always zero-terminated. ^The first 2831 ** parameter "n" is the total size of the buffer, including space for 2832 ** the zero terminator. So the longest string that can be completely 2833 ** written will be n-1 characters. 2834 ** 2835 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2836 ** 2837 ** See also: [built-in printf()], [printf() SQL function] 2838 */ 2839 SQLITE_API char *sqlite3_mprintf(const char*,...); 2840 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2841 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2842 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2843 2844 /* 2845 ** CAPI3REF: Memory Allocation Subsystem 2846 ** 2847 ** The SQLite core uses these three routines for all of its own 2848 ** internal memory allocation needs. "Core" in the previous sentence 2849 ** does not include operating-system specific [VFS] implementation. The 2850 ** Windows VFS uses native malloc() and free() for some operations. 2851 ** 2852 ** ^The sqlite3_malloc() routine returns a pointer to a block 2853 ** of memory at least N bytes in length, where N is the parameter. 2854 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2855 ** memory, it returns a NULL pointer. ^If the parameter N to 2856 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2857 ** a NULL pointer. 2858 ** 2859 ** ^The sqlite3_malloc64(N) routine works just like 2860 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2861 ** of a signed 32-bit integer. 2862 ** 2863 ** ^Calling sqlite3_free() with a pointer previously returned 2864 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2865 ** that it might be reused. ^The sqlite3_free() routine is 2866 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2867 ** to sqlite3_free() is harmless. After being freed, memory 2868 ** should neither be read nor written. Even reading previously freed 2869 ** memory might result in a segmentation fault or other severe error. 2870 ** Memory corruption, a segmentation fault, or other severe error 2871 ** might result if sqlite3_free() is called with a non-NULL pointer that 2872 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2873 ** 2874 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 2875 ** prior memory allocation X to be at least N bytes. 2876 ** ^If the X parameter to sqlite3_realloc(X,N) 2877 ** is a NULL pointer then its behavior is identical to calling 2878 ** sqlite3_malloc(N). 2879 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2880 ** negative then the behavior is exactly the same as calling 2881 ** sqlite3_free(X). 2882 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2883 ** of at least N bytes in size or NULL if insufficient memory is available. 2884 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2885 ** of the prior allocation are copied into the beginning of buffer returned 2886 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 2887 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2888 ** prior allocation is not freed. 2889 ** 2890 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 2891 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2892 ** of a 32-bit signed integer. 2893 ** 2894 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2895 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2896 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2897 ** ^The value returned by sqlite3_msize(X) might be larger than the number 2898 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 2899 ** sqlite3_msize(X) returns zero. If X points to something that is not 2900 ** the beginning of memory allocation, or if it points to a formerly 2901 ** valid memory allocation that has now been freed, then the behavior 2902 ** of sqlite3_msize(X) is undefined and possibly harmful. 2903 ** 2904 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2905 ** sqlite3_malloc64(), and sqlite3_realloc64() 2906 ** is always aligned to at least an 8 byte boundary, or to a 2907 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2908 ** option is used. 2909 ** 2910 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2911 ** must be either NULL or else pointers obtained from a prior 2912 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2913 ** not yet been released. 2914 ** 2915 ** The application must not read or write any part of 2916 ** a block of memory after it has been released using 2917 ** [sqlite3_free()] or [sqlite3_realloc()]. 2918 */ 2919 SQLITE_API void *sqlite3_malloc(int); 2920 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 2921 SQLITE_API void *sqlite3_realloc(void*, int); 2922 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 2923 SQLITE_API void sqlite3_free(void*); 2924 SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 2925 2926 /* 2927 ** CAPI3REF: Memory Allocator Statistics 2928 ** 2929 ** SQLite provides these two interfaces for reporting on the status 2930 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2931 ** routines, which form the built-in memory allocation subsystem. 2932 ** 2933 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2934 ** of memory currently outstanding (malloced but not freed). 2935 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2936 ** value of [sqlite3_memory_used()] since the high-water mark 2937 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2938 ** [sqlite3_memory_highwater()] include any overhead 2939 ** added by SQLite in its implementation of [sqlite3_malloc()], 2940 ** but not overhead added by the any underlying system library 2941 ** routines that [sqlite3_malloc()] may call. 2942 ** 2943 ** ^The memory high-water mark is reset to the current value of 2944 ** [sqlite3_memory_used()] if and only if the parameter to 2945 ** [sqlite3_memory_highwater()] is true. ^The value returned 2946 ** by [sqlite3_memory_highwater(1)] is the high-water mark 2947 ** prior to the reset. 2948 */ 2949 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2950 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2951 2952 /* 2953 ** CAPI3REF: Pseudo-Random Number Generator 2954 ** 2955 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2956 ** select random [ROWID | ROWIDs] when inserting new records into a table that 2957 ** already uses the largest possible [ROWID]. The PRNG is also used for 2958 ** the built-in random() and randomblob() SQL functions. This interface allows 2959 ** applications to access the same PRNG for other purposes. 2960 ** 2961 ** ^A call to this routine stores N bytes of randomness into buffer P. 2962 ** ^The P parameter can be a NULL pointer. 2963 ** 2964 ** ^If this routine has not been previously called or if the previous 2965 ** call had N less than one or a NULL pointer for P, then the PRNG is 2966 ** seeded using randomness obtained from the xRandomness method of 2967 ** the default [sqlite3_vfs] object. 2968 ** ^If the previous call to this routine had an N of 1 or more and a 2969 ** non-NULL P then the pseudo-randomness is generated 2970 ** internally and without recourse to the [sqlite3_vfs] xRandomness 2971 ** method. 2972 */ 2973 SQLITE_API void sqlite3_randomness(int N, void *P); 2974 2975 /* 2976 ** CAPI3REF: Compile-Time Authorization Callbacks 2977 ** METHOD: sqlite3 2978 ** KEYWORDS: {authorizer callback} 2979 ** 2980 ** ^This routine registers an authorizer callback with a particular 2981 ** [database connection], supplied in the first argument. 2982 ** ^The authorizer callback is invoked as SQL statements are being compiled 2983 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2984 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2985 ** and [sqlite3_prepare16_v3()]. ^At various 2986 ** points during the compilation process, as logic is being created 2987 ** to perform various actions, the authorizer callback is invoked to 2988 ** see if those actions are allowed. ^The authorizer callback should 2989 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2990 ** specific action but allow the SQL statement to continue to be 2991 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2992 ** rejected with an error. ^If the authorizer callback returns 2993 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2994 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2995 ** the authorizer will fail with an error message. 2996 ** 2997 ** When the callback returns [SQLITE_OK], that means the operation 2998 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 2999 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 3000 ** authorizer will fail with an error message explaining that 3001 ** access is denied. 3002 ** 3003 ** ^The first parameter to the authorizer callback is a copy of the third 3004 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 3005 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 3006 ** the particular action to be authorized. ^The third through sixth parameters 3007 ** to the callback are either NULL pointers or zero-terminated strings 3008 ** that contain additional details about the action to be authorized. 3009 ** Applications must always be prepared to encounter a NULL pointer in any 3010 ** of the third through the sixth parameters of the authorization callback. 3011 ** 3012 ** ^If the action code is [SQLITE_READ] 3013 ** and the callback returns [SQLITE_IGNORE] then the 3014 ** [prepared statement] statement is constructed to substitute 3015 ** a NULL value in place of the table column that would have 3016 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 3017 ** return can be used to deny an untrusted user access to individual 3018 ** columns of a table. 3019 ** ^When a table is referenced by a [SELECT] but no column values are 3020 ** extracted from that table (for example in a query like 3021 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 3022 ** is invoked once for that table with a column name that is an empty string. 3023 ** ^If the action code is [SQLITE_DELETE] and the callback returns 3024 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 3025 ** [truncate optimization] is disabled and all rows are deleted individually. 3026 ** 3027 ** An authorizer is used when [sqlite3_prepare | preparing] 3028 ** SQL statements from an untrusted source, to ensure that the SQL statements 3029 ** do not try to access data they are not allowed to see, or that they do not 3030 ** try to execute malicious statements that damage the database. For 3031 ** example, an application may allow a user to enter arbitrary 3032 ** SQL queries for evaluation by a database. But the application does 3033 ** not want the user to be able to make arbitrary changes to the 3034 ** database. An authorizer could then be put in place while the 3035 ** user-entered SQL is being [sqlite3_prepare | prepared] that 3036 ** disallows everything except [SELECT] statements. 3037 ** 3038 ** Applications that need to process SQL from untrusted sources 3039 ** might also consider lowering resource limits using [sqlite3_limit()] 3040 ** and limiting database size using the [max_page_count] [PRAGMA] 3041 ** in addition to using an authorizer. 3042 ** 3043 ** ^(Only a single authorizer can be in place on a database connection 3044 ** at a time. Each call to sqlite3_set_authorizer overrides the 3045 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 3046 ** The authorizer is disabled by default. 3047 ** 3048 ** The authorizer callback must not do anything that will modify 3049 ** the database connection that invoked the authorizer callback. 3050 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3051 ** database connections for the meaning of "modify" in this paragraph. 3052 ** 3053 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 3054 ** statement might be re-prepared during [sqlite3_step()] due to a 3055 ** schema change. Hence, the application should ensure that the 3056 ** correct authorizer callback remains in place during the [sqlite3_step()]. 3057 ** 3058 ** ^Note that the authorizer callback is invoked only during 3059 ** [sqlite3_prepare()] or its variants. Authorization is not 3060 ** performed during statement evaluation in [sqlite3_step()], unless 3061 ** as stated in the previous paragraph, sqlite3_step() invokes 3062 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 3063 */ 3064 SQLITE_API int sqlite3_set_authorizer( 3065 sqlite3*, 3066 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 3067 void *pUserData 3068 ); 3069 3070 /* 3071 ** CAPI3REF: Authorizer Return Codes 3072 ** 3073 ** The [sqlite3_set_authorizer | authorizer callback function] must 3074 ** return either [SQLITE_OK] or one of these two constants in order 3075 ** to signal SQLite whether or not the action is permitted. See the 3076 ** [sqlite3_set_authorizer | authorizer documentation] for additional 3077 ** information. 3078 ** 3079 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3080 ** returned from the [sqlite3_vtab_on_conflict()] interface. 3081 */ 3082 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 3083 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 3084 3085 /* 3086 ** CAPI3REF: Authorizer Action Codes 3087 ** 3088 ** The [sqlite3_set_authorizer()] interface registers a callback function 3089 ** that is invoked to authorize certain SQL statement actions. The 3090 ** second parameter to the callback is an integer code that specifies 3091 ** what action is being authorized. These are the integer action codes that 3092 ** the authorizer callback may be passed. 3093 ** 3094 ** These action code values signify what kind of operation is to be 3095 ** authorized. The 3rd and 4th parameters to the authorization 3096 ** callback function will be parameters or NULL depending on which of these 3097 ** codes is used as the second parameter. ^(The 5th parameter to the 3098 ** authorizer callback is the name of the database ("main", "temp", 3099 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3100 ** is the name of the inner-most trigger or view that is responsible for 3101 ** the access attempt or NULL if this access attempt is directly from 3102 ** top-level SQL code. 3103 */ 3104 /******************************************* 3rd ************ 4th ***********/ 3105 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3106 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3107 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3108 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3109 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3110 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3111 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3112 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3113 #define SQLITE_DELETE 9 /* Table Name NULL */ 3114 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3115 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3116 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3117 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3118 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3119 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3120 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3121 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3122 #define SQLITE_INSERT 18 /* Table Name NULL */ 3123 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3124 #define SQLITE_READ 20 /* Table Name Column Name */ 3125 #define SQLITE_SELECT 21 /* NULL NULL */ 3126 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 3127 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 3128 #define SQLITE_ATTACH 24 /* Filename NULL */ 3129 #define SQLITE_DETACH 25 /* Database Name NULL */ 3130 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3131 #define SQLITE_REINDEX 27 /* Index Name NULL */ 3132 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 3133 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3134 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3135 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 3136 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3137 #define SQLITE_COPY 0 /* No longer used */ 3138 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 3139 3140 /* 3141 ** CAPI3REF: Tracing And Profiling Functions 3142 ** METHOD: sqlite3 3143 ** 3144 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3145 ** instead of the routines described here. 3146 ** 3147 ** These routines register callback functions that can be used for 3148 ** tracing and profiling the execution of SQL statements. 3149 ** 3150 ** ^The callback function registered by sqlite3_trace() is invoked at 3151 ** various times when an SQL statement is being run by [sqlite3_step()]. 3152 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3153 ** SQL statement text as the statement first begins executing. 3154 ** ^(Additional sqlite3_trace() callbacks might occur 3155 ** as each triggered subprogram is entered. The callbacks for triggers 3156 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 3157 ** 3158 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3159 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3160 ** 3161 ** ^The callback function registered by sqlite3_profile() is invoked 3162 ** as each SQL statement finishes. ^The profile callback contains 3163 ** the original statement text and an estimate of wall-clock time 3164 ** of how long that statement took to run. ^The profile callback 3165 ** time is in units of nanoseconds, however the current implementation 3166 ** is only capable of millisecond resolution so the six least significant 3167 ** digits in the time are meaningless. Future versions of SQLite 3168 ** might provide greater resolution on the profiler callback. Invoking 3169 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3170 ** profile callback. 3171 */ 3172 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3173 void(*xTrace)(void*,const char*), void*); 3174 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3175 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3176 3177 /* 3178 ** CAPI3REF: SQL Trace Event Codes 3179 ** KEYWORDS: SQLITE_TRACE 3180 ** 3181 ** These constants identify classes of events that can be monitored 3182 ** using the [sqlite3_trace_v2()] tracing logic. The M argument 3183 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3184 ** the following constants. ^The first argument to the trace callback 3185 ** is one of the following constants. 3186 ** 3187 ** New tracing constants may be added in future releases. 3188 ** 3189 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 3190 ** ^The T argument is one of the integer type codes above. 3191 ** ^The C argument is a copy of the context pointer passed in as the 3192 ** fourth argument to [sqlite3_trace_v2()]. 3193 ** The P and X arguments are pointers whose meanings depend on T. 3194 ** 3195 ** <dl> 3196 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3197 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3198 ** first begins running and possibly at other times during the 3199 ** execution of the prepared statement, such as at the start of each 3200 ** trigger subprogram. ^The P argument is a pointer to the 3201 ** [prepared statement]. ^The X argument is a pointer to a string which 3202 ** is the unexpanded SQL text of the prepared statement or an SQL comment 3203 ** that indicates the invocation of a trigger. ^The callback can compute 3204 ** the same text that would have been returned by the legacy [sqlite3_trace()] 3205 ** interface by using the X argument when X begins with "--" and invoking 3206 ** [sqlite3_expanded_sql(P)] otherwise. 3207 ** 3208 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3209 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3210 ** information as is provided by the [sqlite3_profile()] callback. 3211 ** ^The P argument is a pointer to the [prepared statement] and the 3212 ** X argument points to a 64-bit integer which is the estimated of 3213 ** the number of nanosecond that the prepared statement took to run. 3214 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3215 ** 3216 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3217 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3218 ** statement generates a single row of result. 3219 ** ^The P argument is a pointer to the [prepared statement] and the 3220 ** X argument is unused. 3221 ** 3222 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3223 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3224 ** connection closes. 3225 ** ^The P argument is a pointer to the [database connection] object 3226 ** and the X argument is unused. 3227 ** </dl> 3228 */ 3229 #define SQLITE_TRACE_STMT 0x01 3230 #define SQLITE_TRACE_PROFILE 0x02 3231 #define SQLITE_TRACE_ROW 0x04 3232 #define SQLITE_TRACE_CLOSE 0x08 3233 3234 /* 3235 ** CAPI3REF: SQL Trace Hook 3236 ** METHOD: sqlite3 3237 ** 3238 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3239 ** function X against [database connection] D, using property mask M 3240 ** and context pointer P. ^If the X callback is 3241 ** NULL or if the M mask is zero, then tracing is disabled. The 3242 ** M argument should be the bitwise OR-ed combination of 3243 ** zero or more [SQLITE_TRACE] constants. 3244 ** 3245 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3246 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3247 ** 3248 ** ^The X callback is invoked whenever any of the events identified by 3249 ** mask M occur. ^The integer return value from the callback is currently 3250 ** ignored, though this may change in future releases. Callback 3251 ** implementations should return zero to ensure future compatibility. 3252 ** 3253 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3254 ** ^The T argument is one of the [SQLITE_TRACE] 3255 ** constants to indicate why the callback was invoked. 3256 ** ^The C argument is a copy of the context pointer. 3257 ** The P and X arguments are pointers whose meanings depend on T. 3258 ** 3259 ** The sqlite3_trace_v2() interface is intended to replace the legacy 3260 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3261 ** are deprecated. 3262 */ 3263 SQLITE_API int sqlite3_trace_v2( 3264 sqlite3*, 3265 unsigned uMask, 3266 int(*xCallback)(unsigned,void*,void*,void*), 3267 void *pCtx 3268 ); 3269 3270 /* 3271 ** CAPI3REF: Query Progress Callbacks 3272 ** METHOD: sqlite3 3273 ** 3274 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3275 ** function X to be invoked periodically during long running calls to 3276 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3277 ** database connection D. An example use for this 3278 ** interface is to keep a GUI updated during a large query. 3279 ** 3280 ** ^The parameter P is passed through as the only parameter to the 3281 ** callback function X. ^The parameter N is the approximate number of 3282 ** [virtual machine instructions] that are evaluated between successive 3283 ** invocations of the callback X. ^If N is less than one then the progress 3284 ** handler is disabled. 3285 ** 3286 ** ^Only a single progress handler may be defined at one time per 3287 ** [database connection]; setting a new progress handler cancels the 3288 ** old one. ^Setting parameter X to NULL disables the progress handler. 3289 ** ^The progress handler is also disabled by setting N to a value less 3290 ** than 1. 3291 ** 3292 ** ^If the progress callback returns non-zero, the operation is 3293 ** interrupted. This feature can be used to implement a 3294 ** "Cancel" button on a GUI progress dialog box. 3295 ** 3296 ** The progress handler callback must not do anything that will modify 3297 ** the database connection that invoked the progress handler. 3298 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3299 ** database connections for the meaning of "modify" in this paragraph. 3300 ** 3301 */ 3302 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3303 3304 /* 3305 ** CAPI3REF: Opening A New Database Connection 3306 ** CONSTRUCTOR: sqlite3 3307 ** 3308 ** ^These routines open an SQLite database file as specified by the 3309 ** filename argument. ^The filename argument is interpreted as UTF-8 for 3310 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3311 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 3312 ** returned in *ppDb, even if an error occurs. The only exception is that 3313 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3314 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3315 ** object.)^ ^(If the database is opened (and/or created) successfully, then 3316 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3317 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3318 ** an English language description of the error following a failure of any 3319 ** of the sqlite3_open() routines. 3320 ** 3321 ** ^The default encoding will be UTF-8 for databases created using 3322 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3323 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 3324 ** 3325 ** Whether or not an error occurs when it is opened, resources 3326 ** associated with the [database connection] handle should be released by 3327 ** passing it to [sqlite3_close()] when it is no longer required. 3328 ** 3329 ** The sqlite3_open_v2() interface works like sqlite3_open() 3330 ** except that it accepts two additional parameters for additional control 3331 ** over the new database connection. ^(The flags parameter to 3332 ** sqlite3_open_v2() must include, at a minimum, one of the following 3333 ** three flag combinations:)^ 3334 ** 3335 ** <dl> 3336 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3337 ** <dd>The database is opened in read-only mode. If the database does not 3338 ** already exist, an error is returned.</dd>)^ 3339 ** 3340 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3341 ** <dd>The database is opened for reading and writing if possible, or reading 3342 ** only if the file is write protected by the operating system. In either 3343 ** case the database must already exist, otherwise an error is returned.</dd>)^ 3344 ** 3345 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3346 ** <dd>The database is opened for reading and writing, and is created if 3347 ** it does not already exist. This is the behavior that is always used for 3348 ** sqlite3_open() and sqlite3_open16().</dd>)^ 3349 ** </dl> 3350 ** 3351 ** In addition to the required flags, the following optional flags are 3352 ** also supported: 3353 ** 3354 ** <dl> 3355 ** ^(<dt>[SQLITE_OPEN_URI]</dt> 3356 ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^ 3357 ** 3358 ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt> 3359 ** <dd>The database will be opened as an in-memory database. The database 3360 ** is named by the "filename" argument for the purposes of cache-sharing, 3361 ** if shared cache mode is enabled, but the "filename" is otherwise ignored. 3362 ** </dd>)^ 3363 ** 3364 ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt> 3365 ** <dd>The new database connection will use the "multi-thread" 3366 ** [threading mode].)^ This means that separate threads are allowed 3367 ** to use SQLite at the same time, as long as each thread is using 3368 ** a different [database connection]. 3369 ** 3370 ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt> 3371 ** <dd>The new database connection will use the "serialized" 3372 ** [threading mode].)^ This means the multiple threads can safely 3373 ** attempt to use the same database connection at the same time. 3374 ** (Mutexes will block any actual concurrency, but in this mode 3375 ** there is no harm in trying.) 3376 ** 3377 ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt> 3378 ** <dd>The database is opened [shared cache] enabled, overriding 3379 ** the default shared cache setting provided by 3380 ** [sqlite3_enable_shared_cache()].)^ 3381 ** 3382 ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt> 3383 ** <dd>The database is opened [shared cache] disabled, overriding 3384 ** the default shared cache setting provided by 3385 ** [sqlite3_enable_shared_cache()].)^ 3386 ** 3387 ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt> 3388 ** <dd>The database filename is not allowed to be a symbolic link</dd> 3389 ** </dl>)^ 3390 ** 3391 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3392 ** required combinations shown above optionally combined with other 3393 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3394 ** then the behavior is undefined. 3395 ** 3396 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3397 ** [sqlite3_vfs] object that defines the operating system interface that 3398 ** the new database connection should use. ^If the fourth parameter is 3399 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3400 ** 3401 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3402 ** is created for the connection. ^This in-memory database will vanish when 3403 ** the database connection is closed. Future versions of SQLite might 3404 ** make use of additional special filenames that begin with the ":" character. 3405 ** It is recommended that when a database filename actually does begin with 3406 ** a ":" character you should prefix the filename with a pathname such as 3407 ** "./" to avoid ambiguity. 3408 ** 3409 ** ^If the filename is an empty string, then a private, temporary 3410 ** on-disk database will be created. ^This private database will be 3411 ** automatically deleted as soon as the database connection is closed. 3412 ** 3413 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3414 ** 3415 ** ^If [URI filename] interpretation is enabled, and the filename argument 3416 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3417 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3418 ** set in the third argument to sqlite3_open_v2(), or if it has 3419 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3420 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3421 ** URI filename interpretation is turned off 3422 ** by default, but future releases of SQLite might enable URI filename 3423 ** interpretation by default. See "[URI filenames]" for additional 3424 ** information. 3425 ** 3426 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3427 ** authority, then it must be either an empty string or the string 3428 ** "localhost". ^If the authority is not an empty string or "localhost", an 3429 ** error is returned to the caller. ^The fragment component of a URI, if 3430 ** present, is ignored. 3431 ** 3432 ** ^SQLite uses the path component of the URI as the name of the disk file 3433 ** which contains the database. ^If the path begins with a '/' character, 3434 ** then it is interpreted as an absolute path. ^If the path does not begin 3435 ** with a '/' (meaning that the authority section is omitted from the URI) 3436 ** then the path is interpreted as a relative path. 3437 ** ^(On windows, the first component of an absolute path 3438 ** is a drive specification (e.g. "C:").)^ 3439 ** 3440 ** [[core URI query parameters]] 3441 ** The query component of a URI may contain parameters that are interpreted 3442 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3443 ** SQLite and its built-in [VFSes] interpret the 3444 ** following query parameters: 3445 ** 3446 ** <ul> 3447 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3448 ** a VFS object that provides the operating system interface that should 3449 ** be used to access the database file on disk. ^If this option is set to 3450 ** an empty string the default VFS object is used. ^Specifying an unknown 3451 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3452 ** present, then the VFS specified by the option takes precedence over 3453 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3454 ** 3455 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3456 ** "rwc", or "memory". Attempting to set it to any other value is 3457 ** an error)^. 3458 ** ^If "ro" is specified, then the database is opened for read-only 3459 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3460 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3461 ** "rw", then the database is opened for read-write (but not create) 3462 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3463 ** been set. ^Value "rwc" is equivalent to setting both 3464 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3465 ** set to "memory" then a pure [in-memory database] that never reads 3466 ** or writes from disk is used. ^It is an error to specify a value for 3467 ** the mode parameter that is less restrictive than that specified by 3468 ** the flags passed in the third parameter to sqlite3_open_v2(). 3469 ** 3470 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3471 ** "private". ^Setting it to "shared" is equivalent to setting the 3472 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3473 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3474 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3475 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3476 ** a URI filename, its value overrides any behavior requested by setting 3477 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3478 ** 3479 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3480 ** [powersafe overwrite] property does or does not apply to the 3481 ** storage media on which the database file resides. 3482 ** 3483 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3484 ** which if set disables file locking in rollback journal modes. This 3485 ** is useful for accessing a database on a filesystem that does not 3486 ** support locking. Caution: Database corruption might result if two 3487 ** or more processes write to the same database and any one of those 3488 ** processes uses nolock=1. 3489 ** 3490 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3491 ** parameter that indicates that the database file is stored on 3492 ** read-only media. ^When immutable is set, SQLite assumes that the 3493 ** database file cannot be changed, even by a process with higher 3494 ** privilege, and so the database is opened read-only and all locking 3495 ** and change detection is disabled. Caution: Setting the immutable 3496 ** property on a database file that does in fact change can result 3497 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3498 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3499 ** 3500 ** </ul> 3501 ** 3502 ** ^Specifying an unknown parameter in the query component of a URI is not an 3503 ** error. Future versions of SQLite might understand additional query 3504 ** parameters. See "[query parameters with special meaning to SQLite]" for 3505 ** additional information. 3506 ** 3507 ** [[URI filename examples]] <h3>URI filename examples</h3> 3508 ** 3509 ** <table border="1" align=center cellpadding=5> 3510 ** <tr><th> URI filenames <th> Results 3511 ** <tr><td> file:data.db <td> 3512 ** Open the file "data.db" in the current directory. 3513 ** <tr><td> file:/home/fred/data.db<br> 3514 ** file:///home/fred/data.db <br> 3515 ** file://localhost/home/fred/data.db <br> <td> 3516 ** Open the database file "/home/fred/data.db". 3517 ** <tr><td> file://darkstar/home/fred/data.db <td> 3518 ** An error. "darkstar" is not a recognized authority. 3519 ** <tr><td style="white-space:nowrap"> 3520 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3521 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3522 ** C:. Note that the %20 escaping in this example is not strictly 3523 ** necessary - space characters can be used literally 3524 ** in URI filenames. 3525 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3526 ** Open file "data.db" in the current directory for read-only access. 3527 ** Regardless of whether or not shared-cache mode is enabled by 3528 ** default, use a private cache. 3529 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3530 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3531 ** that uses dot-files in place of posix advisory locking. 3532 ** <tr><td> file:data.db?mode=readonly <td> 3533 ** An error. "readonly" is not a valid option for the "mode" parameter. 3534 ** Use "ro" instead: "file:data.db?mode=ro". 3535 ** </table> 3536 ** 3537 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3538 ** query components of a URI. A hexadecimal escape sequence consists of a 3539 ** percent sign - "%" - followed by exactly two hexadecimal digits 3540 ** specifying an octet value. ^Before the path or query components of a 3541 ** URI filename are interpreted, they are encoded using UTF-8 and all 3542 ** hexadecimal escape sequences replaced by a single byte containing the 3543 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3544 ** the results are undefined. 3545 ** 3546 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3547 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3548 ** codepage is currently defined. Filenames containing international 3549 ** characters must be converted to UTF-8 prior to passing them into 3550 ** sqlite3_open() or sqlite3_open_v2(). 3551 ** 3552 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3553 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3554 ** features that require the use of temporary files may fail. 3555 ** 3556 ** See also: [sqlite3_temp_directory] 3557 */ 3558 SQLITE_API int sqlite3_open( 3559 const char *filename, /* Database filename (UTF-8) */ 3560 sqlite3 **ppDb /* OUT: SQLite db handle */ 3561 ); 3562 SQLITE_API int sqlite3_open16( 3563 const void *filename, /* Database filename (UTF-16) */ 3564 sqlite3 **ppDb /* OUT: SQLite db handle */ 3565 ); 3566 SQLITE_API int sqlite3_open_v2( 3567 const char *filename, /* Database filename (UTF-8) */ 3568 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3569 int flags, /* Flags */ 3570 const char *zVfs /* Name of VFS module to use */ 3571 ); 3572 3573 /* 3574 ** CAPI3REF: Obtain Values For URI Parameters 3575 ** 3576 ** These are utility routines, useful to [VFS|custom VFS implementations], 3577 ** that check if a database file was a URI that contained a specific query 3578 ** parameter, and if so obtains the value of that query parameter. 3579 ** 3580 ** The first parameter to these interfaces (hereafter referred to 3581 ** as F) must be one of: 3582 ** <ul> 3583 ** <li> A database filename pointer created by the SQLite core and 3584 ** passed into the xOpen() method of a VFS implemention, or 3585 ** <li> A filename obtained from [sqlite3_db_filename()], or 3586 ** <li> A new filename constructed using [sqlite3_create_filename()]. 3587 ** </ul> 3588 ** If the F parameter is not one of the above, then the behavior is 3589 ** undefined and probably undesirable. Older versions of SQLite were 3590 ** more tolerant of invalid F parameters than newer versions. 3591 ** 3592 ** If F is a suitable filename (as described in the previous paragraph) 3593 ** and if P is the name of the query parameter, then 3594 ** sqlite3_uri_parameter(F,P) returns the value of the P 3595 ** parameter if it exists or a NULL pointer if P does not appear as a 3596 ** query parameter on F. If P is a query parameter of F and it 3597 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3598 ** a pointer to an empty string. 3599 ** 3600 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3601 ** parameter and returns true (1) or false (0) according to the value 3602 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3603 ** value of query parameter P is one of "yes", "true", or "on" in any 3604 ** case or if the value begins with a non-zero number. The 3605 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3606 ** query parameter P is one of "no", "false", or "off" in any case or 3607 ** if the value begins with a numeric zero. If P is not a query 3608 ** parameter on F or if the value of P does not match any of the 3609 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3610 ** 3611 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3612 ** 64-bit signed integer and returns that integer, or D if P does not 3613 ** exist. If the value of P is something other than an integer, then 3614 ** zero is returned. 3615 ** 3616 ** The sqlite3_uri_key(F,N) returns a pointer to the name (not 3617 ** the value) of the N-th query parameter for filename F, or a NULL 3618 ** pointer if N is less than zero or greater than the number of query 3619 ** parameters minus 1. The N value is zero-based so N should be 0 to obtain 3620 ** the name of the first query parameter, 1 for the second parameter, and 3621 ** so forth. 3622 ** 3623 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3624 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3625 ** is not a database file pathname pointer that the SQLite core passed 3626 ** into the xOpen VFS method, then the behavior of this routine is undefined 3627 ** and probably undesirable. 3628 ** 3629 ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F 3630 ** parameter can also be the name of a rollback journal file or WAL file 3631 ** in addition to the main database file. Prior to version 3.31.0, these 3632 ** routines would only work if F was the name of the main database file. 3633 ** When the F parameter is the name of the rollback journal or WAL file, 3634 ** it has access to all the same query parameters as were found on the 3635 ** main database file. 3636 ** 3637 ** See the [URI filename] documentation for additional information. 3638 */ 3639 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3640 SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3641 SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3642 SQLITE_API const char *sqlite3_uri_key(const char *zFilename, int N); 3643 3644 /* 3645 ** CAPI3REF: Translate filenames 3646 ** 3647 ** These routines are available to [VFS|custom VFS implementations] for 3648 ** translating filenames between the main database file, the journal file, 3649 ** and the WAL file. 3650 ** 3651 ** If F is the name of an sqlite database file, journal file, or WAL file 3652 ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F) 3653 ** returns the name of the corresponding database file. 3654 ** 3655 ** If F is the name of an sqlite database file, journal file, or WAL file 3656 ** passed by the SQLite core into the VFS, or if F is a database filename 3657 ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) 3658 ** returns the name of the corresponding rollback journal file. 3659 ** 3660 ** If F is the name of an sqlite database file, journal file, or WAL file 3661 ** that was passed by the SQLite core into the VFS, or if F is a database 3662 ** filename obtained from [sqlite3_db_filename()], then 3663 ** sqlite3_filename_wal(F) returns the name of the corresponding 3664 ** WAL file. 3665 ** 3666 ** In all of the above, if F is not the name of a database, journal or WAL 3667 ** filename passed into the VFS from the SQLite core and F is not the 3668 ** return value from [sqlite3_db_filename()], then the result is 3669 ** undefined and is likely a memory access violation. 3670 */ 3671 SQLITE_API const char *sqlite3_filename_database(const char*); 3672 SQLITE_API const char *sqlite3_filename_journal(const char*); 3673 SQLITE_API const char *sqlite3_filename_wal(const char*); 3674 3675 /* 3676 ** CAPI3REF: Database File Corresponding To A Journal 3677 ** 3678 ** ^If X is the name of a rollback or WAL-mode journal file that is 3679 ** passed into the xOpen method of [sqlite3_vfs], then 3680 ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file] 3681 ** object that represents the main database file. 3682 ** 3683 ** This routine is intended for use in custom [VFS] implementations 3684 ** only. It is not a general-purpose interface. 3685 ** The argument sqlite3_file_object(X) must be a filename pointer that 3686 ** has been passed into [sqlite3_vfs].xOpen method where the 3687 ** flags parameter to xOpen contains one of the bits 3688 ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use 3689 ** of this routine results in undefined and probably undesirable 3690 ** behavior. 3691 */ 3692 SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*); 3693 3694 /* 3695 ** CAPI3REF: Create and Destroy VFS Filenames 3696 ** 3697 ** These interfces are provided for use by [VFS shim] implementations and 3698 ** are not useful outside of that context. 3699 ** 3700 ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of 3701 ** database filename D with corresponding journal file J and WAL file W and 3702 ** with N URI parameters key/values pairs in the array P. The result from 3703 ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that 3704 ** is safe to pass to routines like: 3705 ** <ul> 3706 ** <li> [sqlite3_uri_parameter()], 3707 ** <li> [sqlite3_uri_boolean()], 3708 ** <li> [sqlite3_uri_int64()], 3709 ** <li> [sqlite3_uri_key()], 3710 ** <li> [sqlite3_filename_database()], 3711 ** <li> [sqlite3_filename_journal()], or 3712 ** <li> [sqlite3_filename_wal()]. 3713 ** </ul> 3714 ** If a memory allocation error occurs, sqlite3_create_filename() might 3715 ** return a NULL pointer. The memory obtained from sqlite3_create_filename(X) 3716 ** must be released by a corresponding call to sqlite3_free_filename(Y). 3717 ** 3718 ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array 3719 ** of 2*N pointers to strings. Each pair of pointers in this array corresponds 3720 ** to a key and value for a query parameter. The P parameter may be a NULL 3721 ** pointer if N is zero. None of the 2*N pointers in the P array may be 3722 ** NULL pointers and key pointers should not be empty strings. 3723 ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may 3724 ** be NULL pointers, though they can be empty strings. 3725 ** 3726 ** The sqlite3_free_filename(Y) routine releases a memory allocation 3727 ** previously obtained from sqlite3_create_filename(). Invoking 3728 ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op. 3729 ** 3730 ** If the Y parameter to sqlite3_free_filename(Y) is anything other 3731 ** than a NULL pointer or a pointer previously acquired from 3732 ** sqlite3_create_filename(), then bad things such as heap 3733 ** corruption or segfaults may occur. The value Y should not be 3734 ** used again after sqlite3_free_filename(Y) has been called. This means 3735 ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y, 3736 ** then the corresponding [sqlite3_module.xClose() method should also be 3737 ** invoked prior to calling sqlite3_free_filename(Y). 3738 */ 3739 SQLITE_API char *sqlite3_create_filename( 3740 const char *zDatabase, 3741 const char *zJournal, 3742 const char *zWal, 3743 int nParam, 3744 const char **azParam 3745 ); 3746 SQLITE_API void sqlite3_free_filename(char*); 3747 3748 /* 3749 ** CAPI3REF: Error Codes And Messages 3750 ** METHOD: sqlite3 3751 ** 3752 ** ^If the most recent sqlite3_* API call associated with 3753 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3754 ** returns the numeric [result code] or [extended result code] for that 3755 ** API call. 3756 ** ^The sqlite3_extended_errcode() 3757 ** interface is the same except that it always returns the 3758 ** [extended result code] even when extended result codes are 3759 ** disabled. 3760 ** 3761 ** The values returned by sqlite3_errcode() and/or 3762 ** sqlite3_extended_errcode() might change with each API call. 3763 ** Except, there are some interfaces that are guaranteed to never 3764 ** change the value of the error code. The error-code preserving 3765 ** interfaces are: 3766 ** 3767 ** <ul> 3768 ** <li> sqlite3_errcode() 3769 ** <li> sqlite3_extended_errcode() 3770 ** <li> sqlite3_errmsg() 3771 ** <li> sqlite3_errmsg16() 3772 ** </ul> 3773 ** 3774 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3775 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3776 ** ^(Memory to hold the error message string is managed internally. 3777 ** The application does not need to worry about freeing the result. 3778 ** However, the error string might be overwritten or deallocated by 3779 ** subsequent calls to other SQLite interface functions.)^ 3780 ** 3781 ** ^The sqlite3_errstr() interface returns the English-language text 3782 ** that describes the [result code], as UTF-8. 3783 ** ^(Memory to hold the error message string is managed internally 3784 ** and must not be freed by the application)^. 3785 ** 3786 ** When the serialized [threading mode] is in use, it might be the 3787 ** case that a second error occurs on a separate thread in between 3788 ** the time of the first error and the call to these interfaces. 3789 ** When that happens, the second error will be reported since these 3790 ** interfaces always report the most recent result. To avoid 3791 ** this, each thread can obtain exclusive use of the [database connection] D 3792 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3793 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3794 ** all calls to the interfaces listed here are completed. 3795 ** 3796 ** If an interface fails with SQLITE_MISUSE, that means the interface 3797 ** was invoked incorrectly by the application. In that case, the 3798 ** error code and message may or may not be set. 3799 */ 3800 SQLITE_API int sqlite3_errcode(sqlite3 *db); 3801 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3802 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3803 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3804 SQLITE_API const char *sqlite3_errstr(int); 3805 3806 /* 3807 ** CAPI3REF: Prepared Statement Object 3808 ** KEYWORDS: {prepared statement} {prepared statements} 3809 ** 3810 ** An instance of this object represents a single SQL statement that 3811 ** has been compiled into binary form and is ready to be evaluated. 3812 ** 3813 ** Think of each SQL statement as a separate computer program. The 3814 ** original SQL text is source code. A prepared statement object 3815 ** is the compiled object code. All SQL must be converted into a 3816 ** prepared statement before it can be run. 3817 ** 3818 ** The life-cycle of a prepared statement object usually goes like this: 3819 ** 3820 ** <ol> 3821 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3822 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 3823 ** interfaces. 3824 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3825 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3826 ** to step 2. Do this zero or more times. 3827 ** <li> Destroy the object using [sqlite3_finalize()]. 3828 ** </ol> 3829 */ 3830 typedef struct sqlite3_stmt sqlite3_stmt; 3831 3832 /* 3833 ** CAPI3REF: Run-time Limits 3834 ** METHOD: sqlite3 3835 ** 3836 ** ^(This interface allows the size of various constructs to be limited 3837 ** on a connection by connection basis. The first parameter is the 3838 ** [database connection] whose limit is to be set or queried. The 3839 ** second parameter is one of the [limit categories] that define a 3840 ** class of constructs to be size limited. The third parameter is the 3841 ** new limit for that construct.)^ 3842 ** 3843 ** ^If the new limit is a negative number, the limit is unchanged. 3844 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3845 ** [limits | hard upper bound] 3846 ** set at compile-time by a C preprocessor macro called 3847 ** [limits | SQLITE_MAX_<i>NAME</i>]. 3848 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3849 ** ^Attempts to increase a limit above its hard upper bound are 3850 ** silently truncated to the hard upper bound. 3851 ** 3852 ** ^Regardless of whether or not the limit was changed, the 3853 ** [sqlite3_limit()] interface returns the prior value of the limit. 3854 ** ^Hence, to find the current value of a limit without changing it, 3855 ** simply invoke this interface with the third parameter set to -1. 3856 ** 3857 ** Run-time limits are intended for use in applications that manage 3858 ** both their own internal database and also databases that are controlled 3859 ** by untrusted external sources. An example application might be a 3860 ** web browser that has its own databases for storing history and 3861 ** separate databases controlled by JavaScript applications downloaded 3862 ** off the Internet. The internal databases can be given the 3863 ** large, default limits. Databases managed by external sources can 3864 ** be given much smaller limits designed to prevent a denial of service 3865 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3866 ** interface to further control untrusted SQL. The size of the database 3867 ** created by an untrusted script can be contained using the 3868 ** [max_page_count] [PRAGMA]. 3869 ** 3870 ** New run-time limit categories may be added in future releases. 3871 */ 3872 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3873 3874 /* 3875 ** CAPI3REF: Run-Time Limit Categories 3876 ** KEYWORDS: {limit category} {*limit categories} 3877 ** 3878 ** These constants define various performance limits 3879 ** that can be lowered at run-time using [sqlite3_limit()]. 3880 ** The synopsis of the meanings of the various limits is shown below. 3881 ** Additional information is available at [limits | Limits in SQLite]. 3882 ** 3883 ** <dl> 3884 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3885 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3886 ** 3887 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3888 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3889 ** 3890 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3891 ** <dd>The maximum number of columns in a table definition or in the 3892 ** result set of a [SELECT] or the maximum number of columns in an index 3893 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 3894 ** 3895 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3896 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3897 ** 3898 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3899 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3900 ** 3901 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3902 ** <dd>The maximum number of instructions in a virtual machine program 3903 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3904 ** the equivalent tries to allocate space for more than this many opcodes 3905 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3906 ** 3907 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3908 ** <dd>The maximum number of arguments on a function.</dd>)^ 3909 ** 3910 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3911 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3912 ** 3913 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3914 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3915 ** <dd>The maximum length of the pattern argument to the [LIKE] or 3916 ** [GLOB] operators.</dd>)^ 3917 ** 3918 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3919 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3920 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3921 ** 3922 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3923 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 3924 ** 3925 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3926 ** <dd>The maximum number of auxiliary worker threads that a single 3927 ** [prepared statement] may start.</dd>)^ 3928 ** </dl> 3929 */ 3930 #define SQLITE_LIMIT_LENGTH 0 3931 #define SQLITE_LIMIT_SQL_LENGTH 1 3932 #define SQLITE_LIMIT_COLUMN 2 3933 #define SQLITE_LIMIT_EXPR_DEPTH 3 3934 #define SQLITE_LIMIT_COMPOUND_SELECT 4 3935 #define SQLITE_LIMIT_VDBE_OP 5 3936 #define SQLITE_LIMIT_FUNCTION_ARG 6 3937 #define SQLITE_LIMIT_ATTACHED 7 3938 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3939 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 3940 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 3941 #define SQLITE_LIMIT_WORKER_THREADS 11 3942 3943 /* 3944 ** CAPI3REF: Prepare Flags 3945 ** 3946 ** These constants define various flags that can be passed into 3947 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3948 ** [sqlite3_prepare16_v3()] interfaces. 3949 ** 3950 ** New flags may be added in future releases of SQLite. 3951 ** 3952 ** <dl> 3953 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3954 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3955 ** that the prepared statement will be retained for a long time and 3956 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3957 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3958 ** be used just once or at most a few times and then destroyed using 3959 ** [sqlite3_finalize()] relatively soon. The current implementation acts 3960 ** on this hint by avoiding the use of [lookaside memory] so as not to 3961 ** deplete the limited store of lookaside memory. Future versions of 3962 ** SQLite may act on this hint differently. 3963 ** 3964 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 3965 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 3966 ** to be required for any prepared statement that wanted to use the 3967 ** [sqlite3_normalized_sql()] interface. However, the 3968 ** [sqlite3_normalized_sql()] interface is now available to all 3969 ** prepared statements, regardless of whether or not they use this 3970 ** flag. 3971 ** 3972 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 3973 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 3974 ** to return an error (error code SQLITE_ERROR) if the statement uses 3975 ** any virtual tables. 3976 ** </dl> 3977 */ 3978 #define SQLITE_PREPARE_PERSISTENT 0x01 3979 #define SQLITE_PREPARE_NORMALIZE 0x02 3980 #define SQLITE_PREPARE_NO_VTAB 0x04 3981 3982 /* 3983 ** CAPI3REF: Compiling An SQL Statement 3984 ** KEYWORDS: {SQL statement compiler} 3985 ** METHOD: sqlite3 3986 ** CONSTRUCTOR: sqlite3_stmt 3987 ** 3988 ** To execute an SQL statement, it must first be compiled into a byte-code 3989 ** program using one of these routines. Or, in other words, these routines 3990 ** are constructors for the [prepared statement] object. 3991 ** 3992 ** The preferred routine to use is [sqlite3_prepare_v2()]. The 3993 ** [sqlite3_prepare()] interface is legacy and should be avoided. 3994 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 3995 ** for special purposes. 3996 ** 3997 ** The use of the UTF-8 interfaces is preferred, as SQLite currently 3998 ** does all parsing using UTF-8. The UTF-16 interfaces are provided 3999 ** as a convenience. The UTF-16 interfaces work by converting the 4000 ** input text into UTF-8, then invoking the corresponding UTF-8 interface. 4001 ** 4002 ** The first argument, "db", is a [database connection] obtained from a 4003 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 4004 ** [sqlite3_open16()]. The database connection must not have been closed. 4005 ** 4006 ** The second argument, "zSql", is the statement to be compiled, encoded 4007 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 4008 ** and sqlite3_prepare_v3() 4009 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 4010 ** and sqlite3_prepare16_v3() use UTF-16. 4011 ** 4012 ** ^If the nByte argument is negative, then zSql is read up to the 4013 ** first zero terminator. ^If nByte is positive, then it is the 4014 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 4015 ** statement is generated. 4016 ** If the caller knows that the supplied string is nul-terminated, then 4017 ** there is a small performance advantage to passing an nByte parameter that 4018 ** is the number of bytes in the input string <i>including</i> 4019 ** the nul-terminator. 4020 ** 4021 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 4022 ** past the end of the first SQL statement in zSql. These routines only 4023 ** compile the first statement in zSql, so *pzTail is left pointing to 4024 ** what remains uncompiled. 4025 ** 4026 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 4027 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 4028 ** to NULL. ^If the input text contains no SQL (if the input is an empty 4029 ** string or a comment) then *ppStmt is set to NULL. 4030 ** The calling procedure is responsible for deleting the compiled 4031 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 4032 ** ppStmt may not be NULL. 4033 ** 4034 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 4035 ** otherwise an [error code] is returned. 4036 ** 4037 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 4038 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 4039 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 4040 ** are retained for backwards compatibility, but their use is discouraged. 4041 ** ^In the "vX" interfaces, the prepared statement 4042 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 4043 ** original SQL text. This causes the [sqlite3_step()] interface to 4044 ** behave differently in three ways: 4045 ** 4046 ** <ol> 4047 ** <li> 4048 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 4049 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 4050 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 4051 ** retries will occur before sqlite3_step() gives up and returns an error. 4052 ** </li> 4053 ** 4054 ** <li> 4055 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 4056 ** [error codes] or [extended error codes]. ^The legacy behavior was that 4057 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 4058 ** and the application would have to make a second call to [sqlite3_reset()] 4059 ** in order to find the underlying cause of the problem. With the "v2" prepare 4060 ** interfaces, the underlying reason for the error is returned immediately. 4061 ** </li> 4062 ** 4063 ** <li> 4064 ** ^If the specific value bound to a [parameter | host parameter] in the 4065 ** WHERE clause might influence the choice of query plan for a statement, 4066 ** then the statement will be automatically recompiled, as if there had been 4067 ** a schema change, on the first [sqlite3_step()] call following any change 4068 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 4069 ** ^The specific value of a WHERE-clause [parameter] might influence the 4070 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 4071 ** or [GLOB] operator or if the parameter is compared to an indexed column 4072 ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 4073 ** </li> 4074 ** </ol> 4075 ** 4076 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 4077 ** the extra prepFlags parameter, which is a bit array consisting of zero or 4078 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 4079 ** sqlite3_prepare_v2() interface works exactly the same as 4080 ** sqlite3_prepare_v3() with a zero prepFlags parameter. 4081 */ 4082 SQLITE_API int sqlite3_prepare( 4083 sqlite3 *db, /* Database handle */ 4084 const char *zSql, /* SQL statement, UTF-8 encoded */ 4085 int nByte, /* Maximum length of zSql in bytes. */ 4086 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4087 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4088 ); 4089 SQLITE_API int sqlite3_prepare_v2( 4090 sqlite3 *db, /* Database handle */ 4091 const char *zSql, /* SQL statement, UTF-8 encoded */ 4092 int nByte, /* Maximum length of zSql in bytes. */ 4093 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4094 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4095 ); 4096 SQLITE_API int sqlite3_prepare_v3( 4097 sqlite3 *db, /* Database handle */ 4098 const char *zSql, /* SQL statement, UTF-8 encoded */ 4099 int nByte, /* Maximum length of zSql in bytes. */ 4100 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4101 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4102 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4103 ); 4104 SQLITE_API int sqlite3_prepare16( 4105 sqlite3 *db, /* Database handle */ 4106 const void *zSql, /* SQL statement, UTF-16 encoded */ 4107 int nByte, /* Maximum length of zSql in bytes. */ 4108 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4109 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4110 ); 4111 SQLITE_API int sqlite3_prepare16_v2( 4112 sqlite3 *db, /* Database handle */ 4113 const void *zSql, /* SQL statement, UTF-16 encoded */ 4114 int nByte, /* Maximum length of zSql in bytes. */ 4115 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4116 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4117 ); 4118 SQLITE_API int sqlite3_prepare16_v3( 4119 sqlite3 *db, /* Database handle */ 4120 const void *zSql, /* SQL statement, UTF-16 encoded */ 4121 int nByte, /* Maximum length of zSql in bytes. */ 4122 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4123 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4124 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4125 ); 4126 4127 /* 4128 ** CAPI3REF: Retrieving Statement SQL 4129 ** METHOD: sqlite3_stmt 4130 ** 4131 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 4132 ** SQL text used to create [prepared statement] P if P was 4133 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 4134 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4135 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 4136 ** string containing the SQL text of prepared statement P with 4137 ** [bound parameters] expanded. 4138 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 4139 ** string containing the normalized SQL text of prepared statement P. The 4140 ** semantics used to normalize a SQL statement are unspecified and subject 4141 ** to change. At a minimum, literal values will be replaced with suitable 4142 ** placeholders. 4143 ** 4144 ** ^(For example, if a prepared statement is created using the SQL 4145 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 4146 ** and parameter :xyz is unbound, then sqlite3_sql() will return 4147 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 4148 ** will return "SELECT 2345,NULL".)^ 4149 ** 4150 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 4151 ** is available to hold the result, or if the result would exceed the 4152 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 4153 ** 4154 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 4155 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 4156 ** option causes sqlite3_expanded_sql() to always return NULL. 4157 ** 4158 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 4159 ** are managed by SQLite and are automatically freed when the prepared 4160 ** statement is finalized. 4161 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 4162 ** is obtained from [sqlite3_malloc()] and must be free by the application 4163 ** by passing it to [sqlite3_free()]. 4164 */ 4165 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 4166 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 4167 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 4168 4169 /* 4170 ** CAPI3REF: Determine If An SQL Statement Writes The Database 4171 ** METHOD: sqlite3_stmt 4172 ** 4173 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 4174 ** and only if the [prepared statement] X makes no direct changes to 4175 ** the content of the database file. 4176 ** 4177 ** Note that [application-defined SQL functions] or 4178 ** [virtual tables] might change the database indirectly as a side effect. 4179 ** ^(For example, if an application defines a function "eval()" that 4180 ** calls [sqlite3_exec()], then the following SQL statement would 4181 ** change the database file through side-effects: 4182 ** 4183 ** <blockquote><pre> 4184 ** SELECT eval('DELETE FROM t1') FROM t2; 4185 ** </pre></blockquote> 4186 ** 4187 ** But because the [SELECT] statement does not change the database file 4188 ** directly, sqlite3_stmt_readonly() would still return true.)^ 4189 ** 4190 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 4191 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 4192 ** since the statements themselves do not actually modify the database but 4193 ** rather they control the timing of when other statements modify the 4194 ** database. ^The [ATTACH] and [DETACH] statements also cause 4195 ** sqlite3_stmt_readonly() to return true since, while those statements 4196 ** change the configuration of a database connection, they do not make 4197 ** changes to the content of the database files on disk. 4198 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 4199 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 4200 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 4201 ** sqlite3_stmt_readonly() returns false for those commands. 4202 ** 4203 ** ^This routine returns false if there is any possibility that the 4204 ** statement might change the database file. ^A false return does 4205 ** not guarantee that the statement will change the database file. 4206 ** ^For example, an UPDATE statement might have a WHERE clause that 4207 ** makes it a no-op, but the sqlite3_stmt_readonly() result would still 4208 ** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a 4209 ** read-only no-op if the table already exists, but 4210 ** sqlite3_stmt_readonly() still returns false for such a statement. 4211 */ 4212 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 4213 4214 /* 4215 ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 4216 ** METHOD: sqlite3_stmt 4217 ** 4218 ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 4219 ** prepared statement S is an EXPLAIN statement, or 2 if the 4220 ** statement S is an EXPLAIN QUERY PLAN. 4221 ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 4222 ** an ordinary statement or a NULL pointer. 4223 */ 4224 SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 4225 4226 /* 4227 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 4228 ** METHOD: sqlite3_stmt 4229 ** 4230 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 4231 ** [prepared statement] S has been stepped at least once using 4232 ** [sqlite3_step(S)] but has neither run to completion (returned 4233 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 4234 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 4235 ** interface returns false if S is a NULL pointer. If S is not a 4236 ** NULL pointer and is not a pointer to a valid [prepared statement] 4237 ** object, then the behavior is undefined and probably undesirable. 4238 ** 4239 ** This interface can be used in combination [sqlite3_next_stmt()] 4240 ** to locate all prepared statements associated with a database 4241 ** connection that are in need of being reset. This can be used, 4242 ** for example, in diagnostic routines to search for prepared 4243 ** statements that are holding a transaction open. 4244 */ 4245 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 4246 4247 /* 4248 ** CAPI3REF: Dynamically Typed Value Object 4249 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 4250 ** 4251 ** SQLite uses the sqlite3_value object to represent all values 4252 ** that can be stored in a database table. SQLite uses dynamic typing 4253 ** for the values it stores. ^Values stored in sqlite3_value objects 4254 ** can be integers, floating point values, strings, BLOBs, or NULL. 4255 ** 4256 ** An sqlite3_value object may be either "protected" or "unprotected". 4257 ** Some interfaces require a protected sqlite3_value. Other interfaces 4258 ** will accept either a protected or an unprotected sqlite3_value. 4259 ** Every interface that accepts sqlite3_value arguments specifies 4260 ** whether or not it requires a protected sqlite3_value. The 4261 ** [sqlite3_value_dup()] interface can be used to construct a new 4262 ** protected sqlite3_value from an unprotected sqlite3_value. 4263 ** 4264 ** The terms "protected" and "unprotected" refer to whether or not 4265 ** a mutex is held. An internal mutex is held for a protected 4266 ** sqlite3_value object but no mutex is held for an unprotected 4267 ** sqlite3_value object. If SQLite is compiled to be single-threaded 4268 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4269 ** or if SQLite is run in one of reduced mutex modes 4270 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4271 ** then there is no distinction between protected and unprotected 4272 ** sqlite3_value objects and they can be used interchangeably. However, 4273 ** for maximum code portability it is recommended that applications 4274 ** still make the distinction between protected and unprotected 4275 ** sqlite3_value objects even when not strictly required. 4276 ** 4277 ** ^The sqlite3_value objects that are passed as parameters into the 4278 ** implementation of [application-defined SQL functions] are protected. 4279 ** ^The sqlite3_value object returned by 4280 ** [sqlite3_column_value()] is unprotected. 4281 ** Unprotected sqlite3_value objects may only be used as arguments 4282 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4283 ** [sqlite3_value_dup()]. 4284 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 4285 ** interfaces require protected sqlite3_value objects. 4286 */ 4287 typedef struct sqlite3_value sqlite3_value; 4288 4289 /* 4290 ** CAPI3REF: SQL Function Context Object 4291 ** 4292 ** The context in which an SQL function executes is stored in an 4293 ** sqlite3_context object. ^A pointer to an sqlite3_context object 4294 ** is always first parameter to [application-defined SQL functions]. 4295 ** The application-defined SQL function implementation will pass this 4296 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4297 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4298 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4299 ** and/or [sqlite3_set_auxdata()]. 4300 */ 4301 typedef struct sqlite3_context sqlite3_context; 4302 4303 /* 4304 ** CAPI3REF: Binding Values To Prepared Statements 4305 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4306 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4307 ** METHOD: sqlite3_stmt 4308 ** 4309 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4310 ** literals may be replaced by a [parameter] that matches one of following 4311 ** templates: 4312 ** 4313 ** <ul> 4314 ** <li> ? 4315 ** <li> ?NNN 4316 ** <li> :VVV 4317 ** <li> @VVV 4318 ** <li> $VVV 4319 ** </ul> 4320 ** 4321 ** In the templates above, NNN represents an integer literal, 4322 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 4323 ** parameters (also called "host parameter names" or "SQL parameters") 4324 ** can be set using the sqlite3_bind_*() routines defined here. 4325 ** 4326 ** ^The first argument to the sqlite3_bind_*() routines is always 4327 ** a pointer to the [sqlite3_stmt] object returned from 4328 ** [sqlite3_prepare_v2()] or its variants. 4329 ** 4330 ** ^The second argument is the index of the SQL parameter to be set. 4331 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 4332 ** SQL parameter is used more than once, second and subsequent 4333 ** occurrences have the same index as the first occurrence. 4334 ** ^The index for named parameters can be looked up using the 4335 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 4336 ** for "?NNN" parameters is the value of NNN. 4337 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 4338 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766). 4339 ** 4340 ** ^The third argument is the value to bind to the parameter. 4341 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4342 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4343 ** is ignored and the end result is the same as sqlite3_bind_null(). 4344 ** ^If the third parameter to sqlite3_bind_text() is not NULL, then 4345 ** it should be a pointer to well-formed UTF8 text. 4346 ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then 4347 ** it should be a pointer to well-formed UTF16 text. 4348 ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then 4349 ** it should be a pointer to a well-formed unicode string that is 4350 ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16 4351 ** otherwise. 4352 ** 4353 ** [[byte-order determination rules]] ^The byte-order of 4354 ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF) 4355 ** found in first character, which is removed, or in the absence of a BOM 4356 ** the byte order is the native byte order of the host 4357 ** machine for sqlite3_bind_text16() or the byte order specified in 4358 ** the 6th parameter for sqlite3_bind_text64().)^ 4359 ** ^If UTF16 input text contains invalid unicode 4360 ** characters, then SQLite might change those invalid characters 4361 ** into the unicode replacement character: U+FFFD. 4362 ** 4363 ** ^(In those routines that have a fourth argument, its value is the 4364 ** number of bytes in the parameter. To be clear: the value is the 4365 ** number of <u>bytes</u> in the value, not the number of characters.)^ 4366 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4367 ** is negative, then the length of the string is 4368 ** the number of bytes up to the first zero terminator. 4369 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 4370 ** the behavior is undefined. 4371 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4372 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4373 ** that parameter must be the byte offset 4374 ** where the NUL terminator would occur assuming the string were NUL 4375 ** terminated. If any NUL characters occurs at byte offsets less than 4376 ** the value of the fourth parameter then the resulting string value will 4377 ** contain embedded NULs. The result of expressions involving strings 4378 ** with embedded NULs is undefined. 4379 ** 4380 ** ^The fifth argument to the BLOB and string binding interfaces controls 4381 ** or indicates the lifetime of the object referenced by the third parameter. 4382 ** These three options exist: 4383 ** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished 4384 ** with it may be passed. ^It is called to dispose of the BLOB or string even 4385 ** if the call to the bind API fails, except the destructor is not called if 4386 ** the third parameter is a NULL pointer or the fourth parameter is negative. 4387 ** ^ (2) The special constant, [SQLITE_STATIC], may be passsed to indicate that 4388 ** the application remains responsible for disposing of the object. ^In this 4389 ** case, the object and the provided pointer to it must remain valid until 4390 ** either the prepared statement is finalized or the same SQL parameter is 4391 ** bound to something else, whichever occurs sooner. 4392 ** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the 4393 ** object is to be copied prior to the return from sqlite3_bind_*(). ^The 4394 ** object and pointer to it must remain valid until then. ^SQLite will then 4395 ** manage the lifetime of its private copy. 4396 ** 4397 ** ^The sixth argument to sqlite3_bind_text64() must be one of 4398 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4399 ** to specify the encoding of the text in the third parameter. If 4400 ** the sixth argument to sqlite3_bind_text64() is not one of the 4401 ** allowed values shown above, or if the text encoding is different 4402 ** from the encoding specified by the sixth parameter, then the behavior 4403 ** is undefined. 4404 ** 4405 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4406 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4407 ** (just an integer to hold its size) while it is being processed. 4408 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 4409 ** content is later written using 4410 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 4411 ** ^A negative value for the zeroblob results in a zero-length BLOB. 4412 ** 4413 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4414 ** [prepared statement] S to have an SQL value of NULL, but to also be 4415 ** associated with the pointer P of type T. ^D is either a NULL pointer or 4416 ** a pointer to a destructor function for P. ^SQLite will invoke the 4417 ** destructor D with a single argument of P when it is finished using 4418 ** P. The T parameter should be a static string, preferably a string 4419 ** literal. The sqlite3_bind_pointer() routine is part of the 4420 ** [pointer passing interface] added for SQLite 3.20.0. 4421 ** 4422 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4423 ** for the [prepared statement] or with a prepared statement for which 4424 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4425 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4426 ** routine is passed a [prepared statement] that has been finalized, the 4427 ** result is undefined and probably harmful. 4428 ** 4429 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4430 ** ^Unbound parameters are interpreted as NULL. 4431 ** 4432 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4433 ** [error code] if anything goes wrong. 4434 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4435 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4436 ** [SQLITE_MAX_LENGTH]. 4437 ** ^[SQLITE_RANGE] is returned if the parameter 4438 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4439 ** 4440 ** See also: [sqlite3_bind_parameter_count()], 4441 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4442 */ 4443 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4444 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4445 void(*)(void*)); 4446 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 4447 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 4448 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4449 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 4450 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4451 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4452 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4453 void(*)(void*), unsigned char encoding); 4454 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4455 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4456 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4457 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4458 4459 /* 4460 ** CAPI3REF: Number Of SQL Parameters 4461 ** METHOD: sqlite3_stmt 4462 ** 4463 ** ^This routine can be used to find the number of [SQL parameters] 4464 ** in a [prepared statement]. SQL parameters are tokens of the 4465 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4466 ** placeholders for values that are [sqlite3_bind_blob | bound] 4467 ** to the parameters at a later time. 4468 ** 4469 ** ^(This routine actually returns the index of the largest (rightmost) 4470 ** parameter. For all forms except ?NNN, this will correspond to the 4471 ** number of unique parameters. If parameters of the ?NNN form are used, 4472 ** there may be gaps in the list.)^ 4473 ** 4474 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4475 ** [sqlite3_bind_parameter_name()], and 4476 ** [sqlite3_bind_parameter_index()]. 4477 */ 4478 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 4479 4480 /* 4481 ** CAPI3REF: Name Of A Host Parameter 4482 ** METHOD: sqlite3_stmt 4483 ** 4484 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 4485 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 4486 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4487 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4488 ** respectively. 4489 ** In other words, the initial ":" or "$" or "@" or "?" 4490 ** is included as part of the name.)^ 4491 ** ^Parameters of the form "?" without a following integer have no name 4492 ** and are referred to as "nameless" or "anonymous parameters". 4493 ** 4494 ** ^The first host parameter has an index of 1, not 0. 4495 ** 4496 ** ^If the value N is out of range or if the N-th parameter is 4497 ** nameless, then NULL is returned. ^The returned string is 4498 ** always in UTF-8 encoding even if the named parameter was 4499 ** originally specified as UTF-16 in [sqlite3_prepare16()], 4500 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4501 ** 4502 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4503 ** [sqlite3_bind_parameter_count()], and 4504 ** [sqlite3_bind_parameter_index()]. 4505 */ 4506 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4507 4508 /* 4509 ** CAPI3REF: Index Of A Parameter With A Given Name 4510 ** METHOD: sqlite3_stmt 4511 ** 4512 ** ^Return the index of an SQL parameter given its name. ^The 4513 ** index value returned is suitable for use as the second 4514 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4515 ** is returned if no matching parameter is found. ^The parameter 4516 ** name must be given in UTF-8 even if the original statement 4517 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4518 ** [sqlite3_prepare16_v3()]. 4519 ** 4520 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4521 ** [sqlite3_bind_parameter_count()], and 4522 ** [sqlite3_bind_parameter_name()]. 4523 */ 4524 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4525 4526 /* 4527 ** CAPI3REF: Reset All Bindings On A Prepared Statement 4528 ** METHOD: sqlite3_stmt 4529 ** 4530 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4531 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4532 ** ^Use this routine to reset all host parameters to NULL. 4533 */ 4534 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4535 4536 /* 4537 ** CAPI3REF: Number Of Columns In A Result Set 4538 ** METHOD: sqlite3_stmt 4539 ** 4540 ** ^Return the number of columns in the result set returned by the 4541 ** [prepared statement]. ^If this routine returns 0, that means the 4542 ** [prepared statement] returns no data (for example an [UPDATE]). 4543 ** ^However, just because this routine returns a positive number does not 4544 ** mean that one or more rows of data will be returned. ^A SELECT statement 4545 ** will always have a positive sqlite3_column_count() but depending on the 4546 ** WHERE clause constraints and the table content, it might return no rows. 4547 ** 4548 ** See also: [sqlite3_data_count()] 4549 */ 4550 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 4551 4552 /* 4553 ** CAPI3REF: Column Names In A Result Set 4554 ** METHOD: sqlite3_stmt 4555 ** 4556 ** ^These routines return the name assigned to a particular column 4557 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4558 ** interface returns a pointer to a zero-terminated UTF-8 string 4559 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 4560 ** UTF-16 string. ^The first parameter is the [prepared statement] 4561 ** that implements the [SELECT] statement. ^The second parameter is the 4562 ** column number. ^The leftmost column is number 0. 4563 ** 4564 ** ^The returned string pointer is valid until either the [prepared statement] 4565 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4566 ** reprepared by the first call to [sqlite3_step()] for a particular run 4567 ** or until the next call to 4568 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4569 ** 4570 ** ^If sqlite3_malloc() fails during the processing of either routine 4571 ** (for example during a conversion from UTF-8 to UTF-16) then a 4572 ** NULL pointer is returned. 4573 ** 4574 ** ^The name of a result column is the value of the "AS" clause for 4575 ** that column, if there is an AS clause. If there is no AS clause 4576 ** then the name of the column is unspecified and may change from 4577 ** one release of SQLite to the next. 4578 */ 4579 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4580 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4581 4582 /* 4583 ** CAPI3REF: Source Of Data In A Query Result 4584 ** METHOD: sqlite3_stmt 4585 ** 4586 ** ^These routines provide a means to determine the database, table, and 4587 ** table column that is the origin of a particular result column in 4588 ** [SELECT] statement. 4589 ** ^The name of the database or table or column can be returned as 4590 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4591 ** the database name, the _table_ routines return the table name, and 4592 ** the origin_ routines return the column name. 4593 ** ^The returned string is valid until the [prepared statement] is destroyed 4594 ** using [sqlite3_finalize()] or until the statement is automatically 4595 ** reprepared by the first call to [sqlite3_step()] for a particular run 4596 ** or until the same information is requested 4597 ** again in a different encoding. 4598 ** 4599 ** ^The names returned are the original un-aliased names of the 4600 ** database, table, and column. 4601 ** 4602 ** ^The first argument to these interfaces is a [prepared statement]. 4603 ** ^These functions return information about the Nth result column returned by 4604 ** the statement, where N is the second function argument. 4605 ** ^The left-most column is column 0 for these routines. 4606 ** 4607 ** ^If the Nth column returned by the statement is an expression or 4608 ** subquery and is not a column value, then all of these functions return 4609 ** NULL. ^These routines might also return NULL if a memory allocation error 4610 ** occurs. ^Otherwise, they return the name of the attached database, table, 4611 ** or column that query result column was extracted from. 4612 ** 4613 ** ^As with all other SQLite APIs, those whose names end with "16" return 4614 ** UTF-16 encoded strings and the other functions return UTF-8. 4615 ** 4616 ** ^These APIs are only available if the library was compiled with the 4617 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4618 ** 4619 ** If two or more threads call one or more 4620 ** [sqlite3_column_database_name | column metadata interfaces] 4621 ** for the same [prepared statement] and result column 4622 ** at the same time then the results are undefined. 4623 */ 4624 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4625 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4626 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4627 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4628 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4629 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4630 4631 /* 4632 ** CAPI3REF: Declared Datatype Of A Query Result 4633 ** METHOD: sqlite3_stmt 4634 ** 4635 ** ^(The first parameter is a [prepared statement]. 4636 ** If this statement is a [SELECT] statement and the Nth column of the 4637 ** returned result set of that [SELECT] is a table column (not an 4638 ** expression or subquery) then the declared type of the table 4639 ** column is returned.)^ ^If the Nth column of the result set is an 4640 ** expression or subquery, then a NULL pointer is returned. 4641 ** ^The returned string is always UTF-8 encoded. 4642 ** 4643 ** ^(For example, given the database schema: 4644 ** 4645 ** CREATE TABLE t1(c1 VARIANT); 4646 ** 4647 ** and the following statement to be compiled: 4648 ** 4649 ** SELECT c1 + 1, c1 FROM t1; 4650 ** 4651 ** this routine would return the string "VARIANT" for the second result 4652 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4653 ** 4654 ** ^SQLite uses dynamic run-time typing. ^So just because a column 4655 ** is declared to contain a particular type does not mean that the 4656 ** data stored in that column is of the declared type. SQLite is 4657 ** strongly typed, but the typing is dynamic not static. ^Type 4658 ** is associated with individual values, not with the containers 4659 ** used to hold those values. 4660 */ 4661 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4662 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4663 4664 /* 4665 ** CAPI3REF: Evaluate An SQL Statement 4666 ** METHOD: sqlite3_stmt 4667 ** 4668 ** After a [prepared statement] has been prepared using any of 4669 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4670 ** or [sqlite3_prepare16_v3()] or one of the legacy 4671 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4672 ** must be called one or more times to evaluate the statement. 4673 ** 4674 ** The details of the behavior of the sqlite3_step() interface depend 4675 ** on whether the statement was prepared using the newer "vX" interfaces 4676 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4677 ** [sqlite3_prepare16_v2()] or the older legacy 4678 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4679 ** new "vX" interface is recommended for new applications but the legacy 4680 ** interface will continue to be supported. 4681 ** 4682 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4683 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4684 ** ^With the "v2" interface, any of the other [result codes] or 4685 ** [extended result codes] might be returned as well. 4686 ** 4687 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4688 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 4689 ** or occurs outside of an explicit transaction, then you can retry the 4690 ** statement. If the statement is not a [COMMIT] and occurs within an 4691 ** explicit transaction then you should rollback the transaction before 4692 ** continuing. 4693 ** 4694 ** ^[SQLITE_DONE] means that the statement has finished executing 4695 ** successfully. sqlite3_step() should not be called again on this virtual 4696 ** machine without first calling [sqlite3_reset()] to reset the virtual 4697 ** machine back to its initial state. 4698 ** 4699 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4700 ** is returned each time a new row of data is ready for processing by the 4701 ** caller. The values may be accessed using the [column access functions]. 4702 ** sqlite3_step() is called again to retrieve the next row of data. 4703 ** 4704 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4705 ** violation) has occurred. sqlite3_step() should not be called again on 4706 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 4707 ** ^With the legacy interface, a more specific error code (for example, 4708 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4709 ** can be obtained by calling [sqlite3_reset()] on the 4710 ** [prepared statement]. ^In the "v2" interface, 4711 ** the more specific error code is returned directly by sqlite3_step(). 4712 ** 4713 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4714 ** Perhaps it was called on a [prepared statement] that has 4715 ** already been [sqlite3_finalize | finalized] or on one that had 4716 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4717 ** be the case that the same database connection is being used by two or 4718 ** more threads at the same moment in time. 4719 ** 4720 ** For all versions of SQLite up to and including 3.6.23.1, a call to 4721 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 4722 ** other than [SQLITE_ROW] before any subsequent invocation of 4723 ** sqlite3_step(). Failure to reset the prepared statement using 4724 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4725 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4726 ** sqlite3_step() began 4727 ** calling [sqlite3_reset()] automatically in this circumstance rather 4728 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4729 ** break because any application that ever receives an SQLITE_MISUSE error 4730 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4731 ** can be used to restore the legacy behavior. 4732 ** 4733 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4734 ** API always returns a generic error code, [SQLITE_ERROR], following any 4735 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4736 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4737 ** specific [error codes] that better describes the error. 4738 ** We admit that this is a goofy design. The problem has been fixed 4739 ** with the "v2" interface. If you prepare all of your SQL statements 4740 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4741 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4742 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4743 ** then the more specific [error codes] are returned directly 4744 ** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4745 */ 4746 SQLITE_API int sqlite3_step(sqlite3_stmt*); 4747 4748 /* 4749 ** CAPI3REF: Number of columns in a result set 4750 ** METHOD: sqlite3_stmt 4751 ** 4752 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 4753 ** current row of the result set of [prepared statement] P. 4754 ** ^If prepared statement P does not have results ready to return 4755 ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 4756 ** interfaces) then sqlite3_data_count(P) returns 0. 4757 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4758 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4759 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4760 ** will return non-zero if previous call to [sqlite3_step](P) returned 4761 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4762 ** where it always returns zero since each step of that multi-step 4763 ** pragma returns 0 columns of data. 4764 ** 4765 ** See also: [sqlite3_column_count()] 4766 */ 4767 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4768 4769 /* 4770 ** CAPI3REF: Fundamental Datatypes 4771 ** KEYWORDS: SQLITE_TEXT 4772 ** 4773 ** ^(Every value in SQLite has one of five fundamental datatypes: 4774 ** 4775 ** <ul> 4776 ** <li> 64-bit signed integer 4777 ** <li> 64-bit IEEE floating point number 4778 ** <li> string 4779 ** <li> BLOB 4780 ** <li> NULL 4781 ** </ul>)^ 4782 ** 4783 ** These constants are codes for each of those types. 4784 ** 4785 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4786 ** for a completely different meaning. Software that links against both 4787 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4788 ** SQLITE_TEXT. 4789 */ 4790 #define SQLITE_INTEGER 1 4791 #define SQLITE_FLOAT 2 4792 #define SQLITE_BLOB 4 4793 #define SQLITE_NULL 5 4794 #ifdef SQLITE_TEXT 4795 # undef SQLITE_TEXT 4796 #else 4797 # define SQLITE_TEXT 3 4798 #endif 4799 #define SQLITE3_TEXT 3 4800 4801 /* 4802 ** CAPI3REF: Result Values From A Query 4803 ** KEYWORDS: {column access functions} 4804 ** METHOD: sqlite3_stmt 4805 ** 4806 ** <b>Summary:</b> 4807 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4808 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4809 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4810 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4811 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4812 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4813 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4814 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4815 ** [sqlite3_value|unprotected sqlite3_value] object. 4816 ** <tr><td> <td> <td> 4817 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4818 ** or a UTF-8 TEXT result in bytes 4819 ** <tr><td><b>sqlite3_column_bytes16 </b> 4820 ** <td>→ <td>Size of UTF-16 4821 ** TEXT in bytes 4822 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4823 ** datatype of the result 4824 ** </table></blockquote> 4825 ** 4826 ** <b>Details:</b> 4827 ** 4828 ** ^These routines return information about a single column of the current 4829 ** result row of a query. ^In every case the first argument is a pointer 4830 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4831 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4832 ** and the second argument is the index of the column for which information 4833 ** should be returned. ^The leftmost column of the result set has the index 0. 4834 ** ^The number of columns in the result can be determined using 4835 ** [sqlite3_column_count()]. 4836 ** 4837 ** If the SQL statement does not currently point to a valid row, or if the 4838 ** column index is out of range, the result is undefined. 4839 ** These routines may only be called when the most recent call to 4840 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4841 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4842 ** If any of these routines are called after [sqlite3_reset()] or 4843 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4844 ** something other than [SQLITE_ROW], the results are undefined. 4845 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4846 ** are called from a different thread while any of these routines 4847 ** are pending, then the results are undefined. 4848 ** 4849 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4850 ** each return the value of a result column in a specific data format. If 4851 ** the result column is not initially in the requested format (for example, 4852 ** if the query returns an integer but the sqlite3_column_text() interface 4853 ** is used to extract the value) then an automatic type conversion is performed. 4854 ** 4855 ** ^The sqlite3_column_type() routine returns the 4856 ** [SQLITE_INTEGER | datatype code] for the initial data type 4857 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4858 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4859 ** The return value of sqlite3_column_type() can be used to decide which 4860 ** of the first six interface should be used to extract the column value. 4861 ** The value returned by sqlite3_column_type() is only meaningful if no 4862 ** automatic type conversions have occurred for the value in question. 4863 ** After a type conversion, the result of calling sqlite3_column_type() 4864 ** is undefined, though harmless. Future 4865 ** versions of SQLite may change the behavior of sqlite3_column_type() 4866 ** following a type conversion. 4867 ** 4868 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4869 ** or sqlite3_column_bytes16() interfaces can be used to determine the size 4870 ** of that BLOB or string. 4871 ** 4872 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4873 ** routine returns the number of bytes in that BLOB or string. 4874 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4875 ** the string to UTF-8 and then returns the number of bytes. 4876 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 4877 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4878 ** the number of bytes in that string. 4879 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4880 ** 4881 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4882 ** routine returns the number of bytes in that BLOB or string. 4883 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4884 ** the string to UTF-16 and then returns the number of bytes. 4885 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4886 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4887 ** the number of bytes in that string. 4888 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4889 ** 4890 ** ^The values returned by [sqlite3_column_bytes()] and 4891 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4892 ** of the string. ^For clarity: the values returned by 4893 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4894 ** bytes in the string, not the number of characters. 4895 ** 4896 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4897 ** even empty strings, are always zero-terminated. ^The return 4898 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4899 ** 4900 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4901 ** [unprotected sqlite3_value] object. In a multithreaded environment, 4902 ** an unprotected sqlite3_value object may only be used safely with 4903 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4904 ** If the [unprotected sqlite3_value] object returned by 4905 ** [sqlite3_column_value()] is used in any other way, including calls 4906 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4907 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4908 ** Hence, the sqlite3_column_value() interface 4909 ** is normally only useful within the implementation of 4910 ** [application-defined SQL functions] or [virtual tables], not within 4911 ** top-level application code. 4912 ** 4913 ** The these routines may attempt to convert the datatype of the result. 4914 ** ^For example, if the internal representation is FLOAT and a text result 4915 ** is requested, [sqlite3_snprintf()] is used internally to perform the 4916 ** conversion automatically. ^(The following table details the conversions 4917 ** that are applied: 4918 ** 4919 ** <blockquote> 4920 ** <table border="1"> 4921 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4922 ** 4923 ** <tr><td> NULL <td> INTEGER <td> Result is 0 4924 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4925 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4926 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4927 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4928 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4929 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4930 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4931 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4932 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4933 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4934 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4935 ** <tr><td> TEXT <td> BLOB <td> No change 4936 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4937 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4938 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4939 ** </table> 4940 ** </blockquote>)^ 4941 ** 4942 ** Note that when type conversions occur, pointers returned by prior 4943 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4944 ** sqlite3_column_text16() may be invalidated. 4945 ** Type conversions and pointer invalidations might occur 4946 ** in the following cases: 4947 ** 4948 ** <ul> 4949 ** <li> The initial content is a BLOB and sqlite3_column_text() or 4950 ** sqlite3_column_text16() is called. A zero-terminator might 4951 ** need to be added to the string.</li> 4952 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4953 ** sqlite3_column_text16() is called. The content must be converted 4954 ** to UTF-16.</li> 4955 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4956 ** sqlite3_column_text() is called. The content must be converted 4957 ** to UTF-8.</li> 4958 ** </ul> 4959 ** 4960 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4961 ** not invalidate a prior pointer, though of course the content of the buffer 4962 ** that the prior pointer references will have been modified. Other kinds 4963 ** of conversion are done in place when it is possible, but sometimes they 4964 ** are not possible and in those cases prior pointers are invalidated. 4965 ** 4966 ** The safest policy is to invoke these routines 4967 ** in one of the following ways: 4968 ** 4969 ** <ul> 4970 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4971 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4972 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4973 ** </ul> 4974 ** 4975 ** In other words, you should call sqlite3_column_text(), 4976 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4977 ** into the desired format, then invoke sqlite3_column_bytes() or 4978 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4979 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4980 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4981 ** with calls to sqlite3_column_bytes(). 4982 ** 4983 ** ^The pointers returned are valid until a type conversion occurs as 4984 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4985 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4986 ** and BLOBs is freed automatically. Do not pass the pointers returned 4987 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4988 ** [sqlite3_free()]. 4989 ** 4990 ** As long as the input parameters are correct, these routines will only 4991 ** fail if an out-of-memory error occurs during a format conversion. 4992 ** Only the following subset of interfaces are subject to out-of-memory 4993 ** errors: 4994 ** 4995 ** <ul> 4996 ** <li> sqlite3_column_blob() 4997 ** <li> sqlite3_column_text() 4998 ** <li> sqlite3_column_text16() 4999 ** <li> sqlite3_column_bytes() 5000 ** <li> sqlite3_column_bytes16() 5001 ** </ul> 5002 ** 5003 ** If an out-of-memory error occurs, then the return value from these 5004 ** routines is the same as if the column had contained an SQL NULL value. 5005 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5006 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5007 ** return value is obtained and before any 5008 ** other SQLite interface is called on the same [database connection]. 5009 */ 5010 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 5011 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 5012 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 5013 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 5014 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 5015 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 5016 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 5017 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 5018 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 5019 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 5020 5021 /* 5022 ** CAPI3REF: Destroy A Prepared Statement Object 5023 ** DESTRUCTOR: sqlite3_stmt 5024 ** 5025 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 5026 ** ^If the most recent evaluation of the statement encountered no errors 5027 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 5028 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 5029 ** sqlite3_finalize(S) returns the appropriate [error code] or 5030 ** [extended error code]. 5031 ** 5032 ** ^The sqlite3_finalize(S) routine can be called at any point during 5033 ** the life cycle of [prepared statement] S: 5034 ** before statement S is ever evaluated, after 5035 ** one or more calls to [sqlite3_reset()], or after any call 5036 ** to [sqlite3_step()] regardless of whether or not the statement has 5037 ** completed execution. 5038 ** 5039 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 5040 ** 5041 ** The application must finalize every [prepared statement] in order to avoid 5042 ** resource leaks. It is a grievous error for the application to try to use 5043 ** a prepared statement after it has been finalized. Any use of a prepared 5044 ** statement after it has been finalized can result in undefined and 5045 ** undesirable behavior such as segfaults and heap corruption. 5046 */ 5047 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 5048 5049 /* 5050 ** CAPI3REF: Reset A Prepared Statement Object 5051 ** METHOD: sqlite3_stmt 5052 ** 5053 ** The sqlite3_reset() function is called to reset a [prepared statement] 5054 ** object back to its initial state, ready to be re-executed. 5055 ** ^Any SQL statement variables that had values bound to them using 5056 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 5057 ** Use [sqlite3_clear_bindings()] to reset the bindings. 5058 ** 5059 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 5060 ** back to the beginning of its program. 5061 ** 5062 ** ^If the most recent call to [sqlite3_step(S)] for the 5063 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 5064 ** or if [sqlite3_step(S)] has never before been called on S, 5065 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 5066 ** 5067 ** ^If the most recent call to [sqlite3_step(S)] for the 5068 ** [prepared statement] S indicated an error, then 5069 ** [sqlite3_reset(S)] returns an appropriate [error code]. 5070 ** 5071 ** ^The [sqlite3_reset(S)] interface does not change the values 5072 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 5073 */ 5074 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 5075 5076 /* 5077 ** CAPI3REF: Create Or Redefine SQL Functions 5078 ** KEYWORDS: {function creation routines} 5079 ** METHOD: sqlite3 5080 ** 5081 ** ^These functions (collectively known as "function creation routines") 5082 ** are used to add SQL functions or aggregates or to redefine the behavior 5083 ** of existing SQL functions or aggregates. The only differences between 5084 ** the three "sqlite3_create_function*" routines are the text encoding 5085 ** expected for the second parameter (the name of the function being 5086 ** created) and the presence or absence of a destructor callback for 5087 ** the application data pointer. Function sqlite3_create_window_function() 5088 ** is similar, but allows the user to supply the extra callback functions 5089 ** needed by [aggregate window functions]. 5090 ** 5091 ** ^The first parameter is the [database connection] to which the SQL 5092 ** function is to be added. ^If an application uses more than one database 5093 ** connection then application-defined SQL functions must be added 5094 ** to each database connection separately. 5095 ** 5096 ** ^The second parameter is the name of the SQL function to be created or 5097 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 5098 ** representation, exclusive of the zero-terminator. ^Note that the name 5099 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 5100 ** ^Any attempt to create a function with a longer name 5101 ** will result in [SQLITE_MISUSE] being returned. 5102 ** 5103 ** ^The third parameter (nArg) 5104 ** is the number of arguments that the SQL function or 5105 ** aggregate takes. ^If this parameter is -1, then the SQL function or 5106 ** aggregate may take any number of arguments between 0 and the limit 5107 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 5108 ** parameter is less than -1 or greater than 127 then the behavior is 5109 ** undefined. 5110 ** 5111 ** ^The fourth parameter, eTextRep, specifies what 5112 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 5113 ** its parameters. The application should set this parameter to 5114 ** [SQLITE_UTF16LE] if the function implementation invokes 5115 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 5116 ** implementation invokes [sqlite3_value_text16be()] on an input, or 5117 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 5118 ** otherwise. ^The same SQL function may be registered multiple times using 5119 ** different preferred text encodings, with different implementations for 5120 ** each encoding. 5121 ** ^When multiple implementations of the same function are available, SQLite 5122 ** will pick the one that involves the least amount of data conversion. 5123 ** 5124 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 5125 ** to signal that the function will always return the same result given 5126 ** the same inputs within a single SQL statement. Most SQL functions are 5127 ** deterministic. The built-in [random()] SQL function is an example of a 5128 ** function that is not deterministic. The SQLite query planner is able to 5129 ** perform additional optimizations on deterministic functions, so use 5130 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 5131 ** 5132 ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 5133 ** flag, which if present prevents the function from being invoked from 5134 ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions, 5135 ** index expressions, or the WHERE clause of partial indexes. 5136 ** 5137 ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for 5138 ** all application-defined SQL functions that do not need to be 5139 ** used inside of triggers, view, CHECK constraints, or other elements of 5140 ** the database schema. This flags is especially recommended for SQL 5141 ** functions that have side effects or reveal internal application state. 5142 ** Without this flag, an attacker might be able to modify the schema of 5143 ** a database file to include invocations of the function with parameters 5144 ** chosen by the attacker, which the application will then execute when 5145 ** the database file is opened and read. 5146 ** 5147 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 5148 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 5149 ** 5150 ** ^The sixth, seventh and eighth parameters passed to the three 5151 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 5152 ** pointers to C-language functions that implement the SQL function or 5153 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 5154 ** callback only; NULL pointers must be passed as the xStep and xFinal 5155 ** parameters. ^An aggregate SQL function requires an implementation of xStep 5156 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 5157 ** SQL function or aggregate, pass NULL pointers for all three function 5158 ** callbacks. 5159 ** 5160 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 5161 ** and xInverse) passed to sqlite3_create_window_function are pointers to 5162 ** C-language callbacks that implement the new function. xStep and xFinal 5163 ** must both be non-NULL. xValue and xInverse may either both be NULL, in 5164 ** which case a regular aggregate function is created, or must both be 5165 ** non-NULL, in which case the new function may be used as either an aggregate 5166 ** or aggregate window function. More details regarding the implementation 5167 ** of aggregate window functions are 5168 ** [user-defined window functions|available here]. 5169 ** 5170 ** ^(If the final parameter to sqlite3_create_function_v2() or 5171 ** sqlite3_create_window_function() is not NULL, then it is destructor for 5172 ** the application data pointer. The destructor is invoked when the function 5173 ** is deleted, either by being overloaded or when the database connection 5174 ** closes.)^ ^The destructor is also invoked if the call to 5175 ** sqlite3_create_function_v2() fails. ^When the destructor callback is 5176 ** invoked, it is passed a single argument which is a copy of the application 5177 ** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 5178 ** 5179 ** ^It is permitted to register multiple implementations of the same 5180 ** functions with the same name but with either differing numbers of 5181 ** arguments or differing preferred text encodings. ^SQLite will use 5182 ** the implementation that most closely matches the way in which the 5183 ** SQL function is used. ^A function implementation with a non-negative 5184 ** nArg parameter is a better match than a function implementation with 5185 ** a negative nArg. ^A function where the preferred text encoding 5186 ** matches the database encoding is a better 5187 ** match than a function where the encoding is different. 5188 ** ^A function where the encoding difference is between UTF16le and UTF16be 5189 ** is a closer match than a function where the encoding difference is 5190 ** between UTF8 and UTF16. 5191 ** 5192 ** ^Built-in functions may be overloaded by new application-defined functions. 5193 ** 5194 ** ^An application-defined function is permitted to call other 5195 ** SQLite interfaces. However, such calls must not 5196 ** close the database connection nor finalize or reset the prepared 5197 ** statement in which the function is running. 5198 */ 5199 SQLITE_API int sqlite3_create_function( 5200 sqlite3 *db, 5201 const char *zFunctionName, 5202 int nArg, 5203 int eTextRep, 5204 void *pApp, 5205 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5206 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5207 void (*xFinal)(sqlite3_context*) 5208 ); 5209 SQLITE_API int sqlite3_create_function16( 5210 sqlite3 *db, 5211 const void *zFunctionName, 5212 int nArg, 5213 int eTextRep, 5214 void *pApp, 5215 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5216 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5217 void (*xFinal)(sqlite3_context*) 5218 ); 5219 SQLITE_API int sqlite3_create_function_v2( 5220 sqlite3 *db, 5221 const char *zFunctionName, 5222 int nArg, 5223 int eTextRep, 5224 void *pApp, 5225 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5226 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5227 void (*xFinal)(sqlite3_context*), 5228 void(*xDestroy)(void*) 5229 ); 5230 SQLITE_API int sqlite3_create_window_function( 5231 sqlite3 *db, 5232 const char *zFunctionName, 5233 int nArg, 5234 int eTextRep, 5235 void *pApp, 5236 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5237 void (*xFinal)(sqlite3_context*), 5238 void (*xValue)(sqlite3_context*), 5239 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 5240 void(*xDestroy)(void*) 5241 ); 5242 5243 /* 5244 ** CAPI3REF: Text Encodings 5245 ** 5246 ** These constant define integer codes that represent the various 5247 ** text encodings supported by SQLite. 5248 */ 5249 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 5250 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 5251 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 5252 #define SQLITE_UTF16 4 /* Use native byte order */ 5253 #define SQLITE_ANY 5 /* Deprecated */ 5254 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 5255 5256 /* 5257 ** CAPI3REF: Function Flags 5258 ** 5259 ** These constants may be ORed together with the 5260 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 5261 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 5262 ** [sqlite3_create_function_v2()]. 5263 ** 5264 ** <dl> 5265 ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd> 5266 ** The SQLITE_DETERMINISTIC flag means that the new function always gives 5267 ** the same output when the input parameters are the same. 5268 ** The [abs|abs() function] is deterministic, for example, but 5269 ** [randomblob|randomblob()] is not. Functions must 5270 ** be deterministic in order to be used in certain contexts such as 5271 ** with the WHERE clause of [partial indexes] or in [generated columns]. 5272 ** SQLite might also optimize deterministic functions by factoring them 5273 ** out of inner loops. 5274 ** </dd> 5275 ** 5276 ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd> 5277 ** The SQLITE_DIRECTONLY flag means that the function may only be invoked 5278 ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in 5279 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5280 ** [expression indexes], [partial indexes], or [generated columns]. 5281 ** The SQLITE_DIRECTONLY flags is a security feature which is recommended 5282 ** for all [application-defined SQL functions], and especially for functions 5283 ** that have side-effects or that could potentially leak sensitive 5284 ** information. 5285 ** </dd> 5286 ** 5287 ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd> 5288 ** The SQLITE_INNOCUOUS flag means that the function is unlikely 5289 ** to cause problems even if misused. An innocuous function should have 5290 ** no side effects and should not depend on any values other than its 5291 ** input parameters. The [abs|abs() function] is an example of an 5292 ** innocuous function. 5293 ** The [load_extension() SQL function] is not innocuous because of its 5294 ** side effects. 5295 ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not 5296 ** exactly the same. The [random|random() function] is an example of a 5297 ** function that is innocuous but not deterministic. 5298 ** <p>Some heightened security settings 5299 ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF]) 5300 ** disable the use of SQL functions inside views and triggers and in 5301 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5302 ** [expression indexes], [partial indexes], and [generated columns] unless 5303 ** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions 5304 ** are innocuous. Developers are advised to avoid using the 5305 ** SQLITE_INNOCUOUS flag for application-defined functions unless the 5306 ** function has been carefully audited and found to be free of potentially 5307 ** security-adverse side-effects and information-leaks. 5308 ** </dd> 5309 ** 5310 ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd> 5311 ** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call 5312 ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5313 ** Specifying this flag makes no difference for scalar or aggregate user 5314 ** functions. However, if it is not specified for a user-defined window 5315 ** function, then any sub-types belonging to arguments passed to the window 5316 ** function may be discarded before the window function is called (i.e. 5317 ** sqlite3_value_subtype() will always return 0). 5318 ** </dd> 5319 ** </dl> 5320 */ 5321 #define SQLITE_DETERMINISTIC 0x000000800 5322 #define SQLITE_DIRECTONLY 0x000080000 5323 #define SQLITE_SUBTYPE 0x000100000 5324 #define SQLITE_INNOCUOUS 0x000200000 5325 5326 /* 5327 ** CAPI3REF: Deprecated Functions 5328 ** DEPRECATED 5329 ** 5330 ** These functions are [deprecated]. In order to maintain 5331 ** backwards compatibility with older code, these functions continue 5332 ** to be supported. However, new applications should avoid 5333 ** the use of these functions. To encourage programmers to avoid 5334 ** these functions, we will not explain what they do. 5335 */ 5336 #ifndef SQLITE_OMIT_DEPRECATED 5337 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5338 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5339 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5340 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 5341 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5342 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5343 void*,sqlite3_int64); 5344 #endif 5345 5346 /* 5347 ** CAPI3REF: Obtaining SQL Values 5348 ** METHOD: sqlite3_value 5349 ** 5350 ** <b>Summary:</b> 5351 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5352 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5353 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5354 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5355 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5356 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5357 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5358 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5359 ** the native byteorder 5360 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5361 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5362 ** <tr><td> <td> <td> 5363 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5364 ** or a UTF-8 TEXT in bytes 5365 ** <tr><td><b>sqlite3_value_bytes16 </b> 5366 ** <td>→ <td>Size of UTF-16 5367 ** TEXT in bytes 5368 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5369 ** datatype of the value 5370 ** <tr><td><b>sqlite3_value_numeric_type </b> 5371 ** <td>→ <td>Best numeric datatype of the value 5372 ** <tr><td><b>sqlite3_value_nochange </b> 5373 ** <td>→ <td>True if the column is unchanged in an UPDATE 5374 ** against a virtual table. 5375 ** <tr><td><b>sqlite3_value_frombind </b> 5376 ** <td>→ <td>True if value originated from a [bound parameter] 5377 ** </table></blockquote> 5378 ** 5379 ** <b>Details:</b> 5380 ** 5381 ** These routines extract type, size, and content information from 5382 ** [protected sqlite3_value] objects. Protected sqlite3_value objects 5383 ** are used to pass parameter information into the functions that 5384 ** implement [application-defined SQL functions] and [virtual tables]. 5385 ** 5386 ** These routines work only with [protected sqlite3_value] objects. 5387 ** Any attempt to use these routines on an [unprotected sqlite3_value] 5388 ** is not threadsafe. 5389 ** 5390 ** ^These routines work just like the corresponding [column access functions] 5391 ** except that these routines take a single [protected sqlite3_value] object 5392 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5393 ** 5394 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5395 ** in the native byte-order of the host machine. ^The 5396 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5397 ** extract UTF-16 strings as big-endian and little-endian respectively. 5398 ** 5399 ** ^If [sqlite3_value] object V was initialized 5400 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5401 ** and if X and Y are strings that compare equal according to strcmp(X,Y), 5402 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5403 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5404 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5405 ** 5406 ** ^(The sqlite3_value_type(V) interface returns the 5407 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5408 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5409 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5410 ** Other interfaces might change the datatype for an sqlite3_value object. 5411 ** For example, if the datatype is initially SQLITE_INTEGER and 5412 ** sqlite3_value_text(V) is called to extract a text value for that 5413 ** integer, then subsequent calls to sqlite3_value_type(V) might return 5414 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5415 ** occurs is undefined and may change from one release of SQLite to the next. 5416 ** 5417 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 5418 ** numeric affinity to the value. This means that an attempt is 5419 ** made to convert the value to an integer or floating point. If 5420 ** such a conversion is possible without loss of information (in other 5421 ** words, if the value is a string that looks like a number) 5422 ** then the conversion is performed. Otherwise no conversion occurs. 5423 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5424 ** 5425 ** ^Within the [xUpdate] method of a [virtual table], the 5426 ** sqlite3_value_nochange(X) interface returns true if and only if 5427 ** the column corresponding to X is unchanged by the UPDATE operation 5428 ** that the xUpdate method call was invoked to implement and if 5429 ** and the prior [xColumn] method call that was invoked to extracted 5430 ** the value for that column returned without setting a result (probably 5431 ** because it queried [sqlite3_vtab_nochange()] and found that the column 5432 ** was unchanging). ^Within an [xUpdate] method, any value for which 5433 ** sqlite3_value_nochange(X) is true will in all other respects appear 5434 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5435 ** than within an [xUpdate] method call for an UPDATE statement, then 5436 ** the return value is arbitrary and meaningless. 5437 ** 5438 ** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5439 ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5440 ** interfaces. ^If X comes from an SQL literal value, or a table column, 5441 ** or an expression, then sqlite3_value_frombind(X) returns zero. 5442 ** 5443 ** Please pay particular attention to the fact that the pointer returned 5444 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5445 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5446 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5447 ** or [sqlite3_value_text16()]. 5448 ** 5449 ** These routines must be called from the same thread as 5450 ** the SQL function that supplied the [sqlite3_value*] parameters. 5451 ** 5452 ** As long as the input parameter is correct, these routines can only 5453 ** fail if an out-of-memory error occurs during a format conversion. 5454 ** Only the following subset of interfaces are subject to out-of-memory 5455 ** errors: 5456 ** 5457 ** <ul> 5458 ** <li> sqlite3_value_blob() 5459 ** <li> sqlite3_value_text() 5460 ** <li> sqlite3_value_text16() 5461 ** <li> sqlite3_value_text16le() 5462 ** <li> sqlite3_value_text16be() 5463 ** <li> sqlite3_value_bytes() 5464 ** <li> sqlite3_value_bytes16() 5465 ** </ul> 5466 ** 5467 ** If an out-of-memory error occurs, then the return value from these 5468 ** routines is the same as if the column had contained an SQL NULL value. 5469 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5470 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5471 ** return value is obtained and before any 5472 ** other SQLite interface is called on the same [database connection]. 5473 */ 5474 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 5475 SQLITE_API double sqlite3_value_double(sqlite3_value*); 5476 SQLITE_API int sqlite3_value_int(sqlite3_value*); 5477 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5478 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 5479 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 5480 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 5481 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 5482 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 5483 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 5484 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 5485 SQLITE_API int sqlite3_value_type(sqlite3_value*); 5486 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 5487 SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 5488 SQLITE_API int sqlite3_value_frombind(sqlite3_value*); 5489 5490 /* 5491 ** CAPI3REF: Finding The Subtype Of SQL Values 5492 ** METHOD: sqlite3_value 5493 ** 5494 ** The sqlite3_value_subtype(V) function returns the subtype for 5495 ** an [application-defined SQL function] argument V. The subtype 5496 ** information can be used to pass a limited amount of context from 5497 ** one SQL function to another. Use the [sqlite3_result_subtype()] 5498 ** routine to set the subtype for the return value of an SQL function. 5499 */ 5500 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 5501 5502 /* 5503 ** CAPI3REF: Copy And Free SQL Values 5504 ** METHOD: sqlite3_value 5505 ** 5506 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5507 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5508 ** is a [protected sqlite3_value] object even if the input is not. 5509 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5510 ** memory allocation fails. 5511 ** 5512 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5513 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5514 ** then sqlite3_value_free(V) is a harmless no-op. 5515 */ 5516 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5517 SQLITE_API void sqlite3_value_free(sqlite3_value*); 5518 5519 /* 5520 ** CAPI3REF: Obtain Aggregate Function Context 5521 ** METHOD: sqlite3_context 5522 ** 5523 ** Implementations of aggregate SQL functions use this 5524 ** routine to allocate memory for storing their state. 5525 ** 5526 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5527 ** for a particular aggregate function, SQLite allocates 5528 ** N bytes of memory, zeroes out that memory, and returns a pointer 5529 ** to the new memory. ^On second and subsequent calls to 5530 ** sqlite3_aggregate_context() for the same aggregate function instance, 5531 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 5532 ** called once for each invocation of the xStep callback and then one 5533 ** last time when the xFinal callback is invoked. ^(When no rows match 5534 ** an aggregate query, the xStep() callback of the aggregate function 5535 ** implementation is never called and xFinal() is called exactly once. 5536 ** In those cases, sqlite3_aggregate_context() might be called for the 5537 ** first time from within xFinal().)^ 5538 ** 5539 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5540 ** when first called if N is less than or equal to zero or if a memory 5541 ** allocate error occurs. 5542 ** 5543 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5544 ** determined by the N parameter on first successful call. Changing the 5545 ** value of N in any subsequent call to sqlite3_aggregate_context() within 5546 ** the same aggregate function instance will not resize the memory 5547 ** allocation.)^ Within the xFinal callback, it is customary to set 5548 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5549 ** pointless memory allocations occur. 5550 ** 5551 ** ^SQLite automatically frees the memory allocated by 5552 ** sqlite3_aggregate_context() when the aggregate query concludes. 5553 ** 5554 ** The first parameter must be a copy of the 5555 ** [sqlite3_context | SQL function context] that is the first parameter 5556 ** to the xStep or xFinal callback routine that implements the aggregate 5557 ** function. 5558 ** 5559 ** This routine must be called from the same thread in which 5560 ** the aggregate SQL function is running. 5561 */ 5562 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5563 5564 /* 5565 ** CAPI3REF: User Data For Functions 5566 ** METHOD: sqlite3_context 5567 ** 5568 ** ^The sqlite3_user_data() interface returns a copy of 5569 ** the pointer that was the pUserData parameter (the 5th parameter) 5570 ** of the [sqlite3_create_function()] 5571 ** and [sqlite3_create_function16()] routines that originally 5572 ** registered the application defined function. 5573 ** 5574 ** This routine must be called from the same thread in which 5575 ** the application-defined function is running. 5576 */ 5577 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 5578 5579 /* 5580 ** CAPI3REF: Database Connection For Functions 5581 ** METHOD: sqlite3_context 5582 ** 5583 ** ^The sqlite3_context_db_handle() interface returns a copy of 5584 ** the pointer to the [database connection] (the 1st parameter) 5585 ** of the [sqlite3_create_function()] 5586 ** and [sqlite3_create_function16()] routines that originally 5587 ** registered the application defined function. 5588 */ 5589 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5590 5591 /* 5592 ** CAPI3REF: Function Auxiliary Data 5593 ** METHOD: sqlite3_context 5594 ** 5595 ** These functions may be used by (non-aggregate) SQL functions to 5596 ** associate metadata with argument values. If the same value is passed to 5597 ** multiple invocations of the same SQL function during query execution, under 5598 ** some circumstances the associated metadata may be preserved. An example 5599 ** of where this might be useful is in a regular-expression matching 5600 ** function. The compiled version of the regular expression can be stored as 5601 ** metadata associated with the pattern string. 5602 ** Then as long as the pattern string remains the same, 5603 ** the compiled regular expression can be reused on multiple 5604 ** invocations of the same function. 5605 ** 5606 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5607 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5608 ** value to the application-defined function. ^N is zero for the left-most 5609 ** function argument. ^If there is no metadata 5610 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5611 ** returns a NULL pointer. 5612 ** 5613 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5614 ** argument of the application-defined function. ^Subsequent 5615 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5616 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5617 ** NULL if the metadata has been discarded. 5618 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5619 ** SQLite will invoke the destructor function X with parameter P exactly 5620 ** once, when the metadata is discarded. 5621 ** SQLite is free to discard the metadata at any time, including: <ul> 5622 ** <li> ^(when the corresponding function parameter changes)^, or 5623 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5624 ** SQL statement)^, or 5625 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5626 ** parameter)^, or 5627 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5628 ** allocation error occurs.)^ </ul> 5629 ** 5630 ** Note the last bullet in particular. The destructor X in 5631 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5632 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5633 ** should be called near the end of the function implementation and the 5634 ** function implementation should not make any use of P after 5635 ** sqlite3_set_auxdata() has been called. 5636 ** 5637 ** ^(In practice, metadata is preserved between function calls for 5638 ** function parameters that are compile-time constants, including literal 5639 ** values and [parameters] and expressions composed from the same.)^ 5640 ** 5641 ** The value of the N parameter to these interfaces should be non-negative. 5642 ** Future enhancements may make use of negative N values to define new 5643 ** kinds of function caching behavior. 5644 ** 5645 ** These routines must be called from the same thread in which 5646 ** the SQL function is running. 5647 */ 5648 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 5649 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5650 5651 5652 /* 5653 ** CAPI3REF: Constants Defining Special Destructor Behavior 5654 ** 5655 ** These are special values for the destructor that is passed in as the 5656 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5657 ** argument is SQLITE_STATIC, it means that the content pointer is constant 5658 ** and will never change. It does not need to be destroyed. ^The 5659 ** SQLITE_TRANSIENT value means that the content will likely change in 5660 ** the near future and that SQLite should make its own private copy of 5661 ** the content before returning. 5662 ** 5663 ** The typedef is necessary to work around problems in certain 5664 ** C++ compilers. 5665 */ 5666 typedef void (*sqlite3_destructor_type)(void*); 5667 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 5668 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5669 5670 /* 5671 ** CAPI3REF: Setting The Result Of An SQL Function 5672 ** METHOD: sqlite3_context 5673 ** 5674 ** These routines are used by the xFunc or xFinal callbacks that 5675 ** implement SQL functions and aggregates. See 5676 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 5677 ** for additional information. 5678 ** 5679 ** These functions work very much like the [parameter binding] family of 5680 ** functions used to bind values to host parameters in prepared statements. 5681 ** Refer to the [SQL parameter] documentation for additional information. 5682 ** 5683 ** ^The sqlite3_result_blob() interface sets the result from 5684 ** an application-defined function to be the BLOB whose content is pointed 5685 ** to by the second parameter and which is N bytes long where N is the 5686 ** third parameter. 5687 ** 5688 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5689 ** interfaces set the result of the application-defined function to be 5690 ** a BLOB containing all zero bytes and N bytes in size. 5691 ** 5692 ** ^The sqlite3_result_double() interface sets the result from 5693 ** an application-defined function to be a floating point value specified 5694 ** by its 2nd argument. 5695 ** 5696 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5697 ** cause the implemented SQL function to throw an exception. 5698 ** ^SQLite uses the string pointed to by the 5699 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5700 ** as the text of an error message. ^SQLite interprets the error 5701 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 5702 ** interprets the string from sqlite3_result_error16() as UTF-16 using 5703 ** the same [byte-order determination rules] as [sqlite3_bind_text16()]. 5704 ** ^If the third parameter to sqlite3_result_error() 5705 ** or sqlite3_result_error16() is negative then SQLite takes as the error 5706 ** message all text up through the first zero character. 5707 ** ^If the third parameter to sqlite3_result_error() or 5708 ** sqlite3_result_error16() is non-negative then SQLite takes that many 5709 ** bytes (not characters) from the 2nd parameter as the error message. 5710 ** ^The sqlite3_result_error() and sqlite3_result_error16() 5711 ** routines make a private copy of the error message text before 5712 ** they return. Hence, the calling function can deallocate or 5713 ** modify the text after they return without harm. 5714 ** ^The sqlite3_result_error_code() function changes the error code 5715 ** returned by SQLite as a result of an error in a function. ^By default, 5716 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5717 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5718 ** 5719 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5720 ** error indicating that a string or BLOB is too long to represent. 5721 ** 5722 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5723 ** error indicating that a memory allocation failed. 5724 ** 5725 ** ^The sqlite3_result_int() interface sets the return value 5726 ** of the application-defined function to be the 32-bit signed integer 5727 ** value given in the 2nd argument. 5728 ** ^The sqlite3_result_int64() interface sets the return value 5729 ** of the application-defined function to be the 64-bit signed integer 5730 ** value given in the 2nd argument. 5731 ** 5732 ** ^The sqlite3_result_null() interface sets the return value 5733 ** of the application-defined function to be NULL. 5734 ** 5735 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 5736 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5737 ** set the return value of the application-defined function to be 5738 ** a text string which is represented as UTF-8, UTF-16 native byte order, 5739 ** UTF-16 little endian, or UTF-16 big endian, respectively. 5740 ** ^The sqlite3_result_text64() interface sets the return value of an 5741 ** application-defined function to be a text string in an encoding 5742 ** specified by the fifth (and last) parameter, which must be one 5743 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5744 ** ^SQLite takes the text result from the application from 5745 ** the 2nd parameter of the sqlite3_result_text* interfaces. 5746 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5747 ** is negative, then SQLite takes result text from the 2nd parameter 5748 ** through the first zero character. 5749 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5750 ** is non-negative, then as many bytes (not characters) of the text 5751 ** pointed to by the 2nd parameter are taken as the application-defined 5752 ** function result. If the 3rd parameter is non-negative, then it 5753 ** must be the byte offset into the string where the NUL terminator would 5754 ** appear if the string where NUL terminated. If any NUL characters occur 5755 ** in the string at a byte offset that is less than the value of the 3rd 5756 ** parameter, then the resulting string will contain embedded NULs and the 5757 ** result of expressions operating on strings with embedded NULs is undefined. 5758 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5759 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5760 ** function as the destructor on the text or BLOB result when it has 5761 ** finished using that result. 5762 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5763 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5764 ** assumes that the text or BLOB result is in constant space and does not 5765 ** copy the content of the parameter nor call a destructor on the content 5766 ** when it has finished using that result. 5767 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5768 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5769 ** then SQLite makes a copy of the result into space obtained 5770 ** from [sqlite3_malloc()] before it returns. 5771 ** 5772 ** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and 5773 ** sqlite3_result_text16be() routines, and for sqlite3_result_text64() 5774 ** when the encoding is not UTF8, if the input UTF16 begins with a 5775 ** byte-order mark (BOM, U+FEFF) then the BOM is removed from the 5776 ** string and the rest of the string is interpreted according to the 5777 ** byte-order specified by the BOM. ^The byte-order specified by 5778 ** the BOM at the beginning of the text overrides the byte-order 5779 ** specified by the interface procedure. ^So, for example, if 5780 ** sqlite3_result_text16le() is invoked with text that begins 5781 ** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the 5782 ** first two bytes of input are skipped and the remaining input 5783 ** is interpreted as UTF16BE text. 5784 ** 5785 ** ^For UTF16 input text to the sqlite3_result_text16(), 5786 ** sqlite3_result_text16be(), sqlite3_result_text16le(), and 5787 ** sqlite3_result_text64() routines, if the text contains invalid 5788 ** UTF16 characters, the invalid characters might be converted 5789 ** into the unicode replacement character, U+FFFD. 5790 ** 5791 ** ^The sqlite3_result_value() interface sets the result of 5792 ** the application-defined function to be a copy of the 5793 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5794 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5795 ** so that the [sqlite3_value] specified in the parameter may change or 5796 ** be deallocated after sqlite3_result_value() returns without harm. 5797 ** ^A [protected sqlite3_value] object may always be used where an 5798 ** [unprotected sqlite3_value] object is required, so either 5799 ** kind of [sqlite3_value] object can be used with this interface. 5800 ** 5801 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5802 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5803 ** also associates the host-language pointer P or type T with that 5804 ** NULL value such that the pointer can be retrieved within an 5805 ** [application-defined SQL function] using [sqlite3_value_pointer()]. 5806 ** ^If the D parameter is not NULL, then it is a pointer to a destructor 5807 ** for the P parameter. ^SQLite invokes D with P as its only argument 5808 ** when SQLite is finished with P. The T parameter should be a static 5809 ** string and preferably a string literal. The sqlite3_result_pointer() 5810 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5811 ** 5812 ** If these routines are called from within the different thread 5813 ** than the one containing the application-defined function that received 5814 ** the [sqlite3_context] pointer, the results are undefined. 5815 */ 5816 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5817 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 5818 sqlite3_uint64,void(*)(void*)); 5819 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 5820 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 5821 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 5822 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 5823 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 5824 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 5825 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 5826 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5827 SQLITE_API void sqlite3_result_null(sqlite3_context*); 5828 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5829 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5830 void(*)(void*), unsigned char encoding); 5831 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5832 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5833 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5834 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5835 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5836 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 5837 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5838 5839 5840 /* 5841 ** CAPI3REF: Setting The Subtype Of An SQL Function 5842 ** METHOD: sqlite3_context 5843 ** 5844 ** The sqlite3_result_subtype(C,T) function causes the subtype of 5845 ** the result from the [application-defined SQL function] with 5846 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 5847 ** of the subtype T are preserved in current versions of SQLite; 5848 ** higher order bits are discarded. 5849 ** The number of subtype bytes preserved by SQLite might increase 5850 ** in future releases of SQLite. 5851 */ 5852 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5853 5854 /* 5855 ** CAPI3REF: Define New Collating Sequences 5856 ** METHOD: sqlite3 5857 ** 5858 ** ^These functions add, remove, or modify a [collation] associated 5859 ** with the [database connection] specified as the first argument. 5860 ** 5861 ** ^The name of the collation is a UTF-8 string 5862 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5863 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5864 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5865 ** considered to be the same name. 5866 ** 5867 ** ^(The third argument (eTextRep) must be one of the constants: 5868 ** <ul> 5869 ** <li> [SQLITE_UTF8], 5870 ** <li> [SQLITE_UTF16LE], 5871 ** <li> [SQLITE_UTF16BE], 5872 ** <li> [SQLITE_UTF16], or 5873 ** <li> [SQLITE_UTF16_ALIGNED]. 5874 ** </ul>)^ 5875 ** ^The eTextRep argument determines the encoding of strings passed 5876 ** to the collating function callback, xCompare. 5877 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5878 ** force strings to be UTF16 with native byte order. 5879 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5880 ** on an even byte address. 5881 ** 5882 ** ^The fourth argument, pArg, is an application data pointer that is passed 5883 ** through as the first argument to the collating function callback. 5884 ** 5885 ** ^The fifth argument, xCompare, is a pointer to the collating function. 5886 ** ^Multiple collating functions can be registered using the same name but 5887 ** with different eTextRep parameters and SQLite will use whichever 5888 ** function requires the least amount of data transformation. 5889 ** ^If the xCompare argument is NULL then the collating function is 5890 ** deleted. ^When all collating functions having the same name are deleted, 5891 ** that collation is no longer usable. 5892 ** 5893 ** ^The collating function callback is invoked with a copy of the pArg 5894 ** application data pointer and with two strings in the encoding specified 5895 ** by the eTextRep argument. The two integer parameters to the collating 5896 ** function callback are the length of the two strings, in bytes. The collating 5897 ** function must return an integer that is negative, zero, or positive 5898 ** if the first string is less than, equal to, or greater than the second, 5899 ** respectively. A collating function must always return the same answer 5900 ** given the same inputs. If two or more collating functions are registered 5901 ** to the same collation name (using different eTextRep values) then all 5902 ** must give an equivalent answer when invoked with equivalent strings. 5903 ** The collating function must obey the following properties for all 5904 ** strings A, B, and C: 5905 ** 5906 ** <ol> 5907 ** <li> If A==B then B==A. 5908 ** <li> If A==B and B==C then A==C. 5909 ** <li> If A<B THEN B>A. 5910 ** <li> If A<B and B<C then A<C. 5911 ** </ol> 5912 ** 5913 ** If a collating function fails any of the above constraints and that 5914 ** collating function is registered and used, then the behavior of SQLite 5915 ** is undefined. 5916 ** 5917 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5918 ** with the addition that the xDestroy callback is invoked on pArg when 5919 ** the collating function is deleted. 5920 ** ^Collating functions are deleted when they are overridden by later 5921 ** calls to the collation creation functions or when the 5922 ** [database connection] is closed using [sqlite3_close()]. 5923 ** 5924 ** ^The xDestroy callback is <u>not</u> called if the 5925 ** sqlite3_create_collation_v2() function fails. Applications that invoke 5926 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5927 ** check the return code and dispose of the application data pointer 5928 ** themselves rather than expecting SQLite to deal with it for them. 5929 ** This is different from every other SQLite interface. The inconsistency 5930 ** is unfortunate but cannot be changed without breaking backwards 5931 ** compatibility. 5932 ** 5933 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5934 */ 5935 SQLITE_API int sqlite3_create_collation( 5936 sqlite3*, 5937 const char *zName, 5938 int eTextRep, 5939 void *pArg, 5940 int(*xCompare)(void*,int,const void*,int,const void*) 5941 ); 5942 SQLITE_API int sqlite3_create_collation_v2( 5943 sqlite3*, 5944 const char *zName, 5945 int eTextRep, 5946 void *pArg, 5947 int(*xCompare)(void*,int,const void*,int,const void*), 5948 void(*xDestroy)(void*) 5949 ); 5950 SQLITE_API int sqlite3_create_collation16( 5951 sqlite3*, 5952 const void *zName, 5953 int eTextRep, 5954 void *pArg, 5955 int(*xCompare)(void*,int,const void*,int,const void*) 5956 ); 5957 5958 /* 5959 ** CAPI3REF: Collation Needed Callbacks 5960 ** METHOD: sqlite3 5961 ** 5962 ** ^To avoid having to register all collation sequences before a database 5963 ** can be used, a single callback function may be registered with the 5964 ** [database connection] to be invoked whenever an undefined collation 5965 ** sequence is required. 5966 ** 5967 ** ^If the function is registered using the sqlite3_collation_needed() API, 5968 ** then it is passed the names of undefined collation sequences as strings 5969 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5970 ** the names are passed as UTF-16 in machine native byte order. 5971 ** ^A call to either function replaces the existing collation-needed callback. 5972 ** 5973 ** ^(When the callback is invoked, the first argument passed is a copy 5974 ** of the second argument to sqlite3_collation_needed() or 5975 ** sqlite3_collation_needed16(). The second argument is the database 5976 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5977 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5978 ** sequence function required. The fourth parameter is the name of the 5979 ** required collation sequence.)^ 5980 ** 5981 ** The callback function should register the desired collation using 5982 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5983 ** [sqlite3_create_collation_v2()]. 5984 */ 5985 SQLITE_API int sqlite3_collation_needed( 5986 sqlite3*, 5987 void*, 5988 void(*)(void*,sqlite3*,int eTextRep,const char*) 5989 ); 5990 SQLITE_API int sqlite3_collation_needed16( 5991 sqlite3*, 5992 void*, 5993 void(*)(void*,sqlite3*,int eTextRep,const void*) 5994 ); 5995 5996 #ifdef SQLITE_ENABLE_CEROD 5997 /* 5998 ** Specify the activation key for a CEROD database. Unless 5999 ** activated, none of the CEROD routines will work. 6000 */ 6001 SQLITE_API void sqlite3_activate_cerod( 6002 const char *zPassPhrase /* Activation phrase */ 6003 ); 6004 #endif 6005 6006 /* 6007 ** CAPI3REF: Suspend Execution For A Short Time 6008 ** 6009 ** The sqlite3_sleep() function causes the current thread to suspend execution 6010 ** for at least a number of milliseconds specified in its parameter. 6011 ** 6012 ** If the operating system does not support sleep requests with 6013 ** millisecond time resolution, then the time will be rounded up to 6014 ** the nearest second. The number of milliseconds of sleep actually 6015 ** requested from the operating system is returned. 6016 ** 6017 ** ^SQLite implements this interface by calling the xSleep() 6018 ** method of the default [sqlite3_vfs] object. If the xSleep() method 6019 ** of the default VFS is not implemented correctly, or not implemented at 6020 ** all, then the behavior of sqlite3_sleep() may deviate from the description 6021 ** in the previous paragraphs. 6022 */ 6023 SQLITE_API int sqlite3_sleep(int); 6024 6025 /* 6026 ** CAPI3REF: Name Of The Folder Holding Temporary Files 6027 ** 6028 ** ^(If this global variable is made to point to a string which is 6029 ** the name of a folder (a.k.a. directory), then all temporary files 6030 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 6031 ** will be placed in that directory.)^ ^If this variable 6032 ** is a NULL pointer, then SQLite performs a search for an appropriate 6033 ** temporary file directory. 6034 ** 6035 ** Applications are strongly discouraged from using this global variable. 6036 ** It is required to set a temporary folder on Windows Runtime (WinRT). 6037 ** But for all other platforms, it is highly recommended that applications 6038 ** neither read nor write this variable. This global variable is a relic 6039 ** that exists for backwards compatibility of legacy applications and should 6040 ** be avoided in new projects. 6041 ** 6042 ** It is not safe to read or modify this variable in more than one 6043 ** thread at a time. It is not safe to read or modify this variable 6044 ** if a [database connection] is being used at the same time in a separate 6045 ** thread. 6046 ** It is intended that this variable be set once 6047 ** as part of process initialization and before any SQLite interface 6048 ** routines have been called and that this variable remain unchanged 6049 ** thereafter. 6050 ** 6051 ** ^The [temp_store_directory pragma] may modify this variable and cause 6052 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6053 ** the [temp_store_directory pragma] always assumes that any string 6054 ** that this variable points to is held in memory obtained from 6055 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6056 ** using [sqlite3_free]. 6057 ** Hence, if this variable is modified directly, either it should be 6058 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6059 ** or else the use of the [temp_store_directory pragma] should be avoided. 6060 ** Except when requested by the [temp_store_directory pragma], SQLite 6061 ** does not free the memory that sqlite3_temp_directory points to. If 6062 ** the application wants that memory to be freed, it must do 6063 ** so itself, taking care to only do so after all [database connection] 6064 ** objects have been destroyed. 6065 ** 6066 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 6067 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 6068 ** features that require the use of temporary files may fail. Here is an 6069 ** example of how to do this using C++ with the Windows Runtime: 6070 ** 6071 ** <blockquote><pre> 6072 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 6073 ** TemporaryFolder->Path->Data(); 6074 ** char zPathBuf[MAX_PATH + 1]; 6075 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 6076 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 6077 ** NULL, NULL); 6078 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 6079 ** </pre></blockquote> 6080 */ 6081 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 6082 6083 /* 6084 ** CAPI3REF: Name Of The Folder Holding Database Files 6085 ** 6086 ** ^(If this global variable is made to point to a string which is 6087 ** the name of a folder (a.k.a. directory), then all database files 6088 ** specified with a relative pathname and created or accessed by 6089 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 6090 ** to be relative to that directory.)^ ^If this variable is a NULL 6091 ** pointer, then SQLite assumes that all database files specified 6092 ** with a relative pathname are relative to the current directory 6093 ** for the process. Only the windows VFS makes use of this global 6094 ** variable; it is ignored by the unix VFS. 6095 ** 6096 ** Changing the value of this variable while a database connection is 6097 ** open can result in a corrupt database. 6098 ** 6099 ** It is not safe to read or modify this variable in more than one 6100 ** thread at a time. It is not safe to read or modify this variable 6101 ** if a [database connection] is being used at the same time in a separate 6102 ** thread. 6103 ** It is intended that this variable be set once 6104 ** as part of process initialization and before any SQLite interface 6105 ** routines have been called and that this variable remain unchanged 6106 ** thereafter. 6107 ** 6108 ** ^The [data_store_directory pragma] may modify this variable and cause 6109 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6110 ** the [data_store_directory pragma] always assumes that any string 6111 ** that this variable points to is held in memory obtained from 6112 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6113 ** using [sqlite3_free]. 6114 ** Hence, if this variable is modified directly, either it should be 6115 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6116 ** or else the use of the [data_store_directory pragma] should be avoided. 6117 */ 6118 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 6119 6120 /* 6121 ** CAPI3REF: Win32 Specific Interface 6122 ** 6123 ** These interfaces are available only on Windows. The 6124 ** [sqlite3_win32_set_directory] interface is used to set the value associated 6125 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 6126 ** zValue, depending on the value of the type parameter. The zValue parameter 6127 ** should be NULL to cause the previous value to be freed via [sqlite3_free]; 6128 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 6129 ** prior to being used. The [sqlite3_win32_set_directory] interface returns 6130 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 6131 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 6132 ** [sqlite3_data_directory] variable is intended to act as a replacement for 6133 ** the current directory on the sub-platforms of Win32 where that concept is 6134 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 6135 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 6136 ** sqlite3_win32_set_directory interface except the string parameter must be 6137 ** UTF-8 or UTF-16, respectively. 6138 */ 6139 SQLITE_API int sqlite3_win32_set_directory( 6140 unsigned long type, /* Identifier for directory being set or reset */ 6141 void *zValue /* New value for directory being set or reset */ 6142 ); 6143 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 6144 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 6145 6146 /* 6147 ** CAPI3REF: Win32 Directory Types 6148 ** 6149 ** These macros are only available on Windows. They define the allowed values 6150 ** for the type argument to the [sqlite3_win32_set_directory] interface. 6151 */ 6152 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 6153 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 6154 6155 /* 6156 ** CAPI3REF: Test For Auto-Commit Mode 6157 ** KEYWORDS: {autocommit mode} 6158 ** METHOD: sqlite3 6159 ** 6160 ** ^The sqlite3_get_autocommit() interface returns non-zero or 6161 ** zero if the given database connection is or is not in autocommit mode, 6162 ** respectively. ^Autocommit mode is on by default. 6163 ** ^Autocommit mode is disabled by a [BEGIN] statement. 6164 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 6165 ** 6166 ** If certain kinds of errors occur on a statement within a multi-statement 6167 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 6168 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 6169 ** transaction might be rolled back automatically. The only way to 6170 ** find out whether SQLite automatically rolled back the transaction after 6171 ** an error is to use this function. 6172 ** 6173 ** If another thread changes the autocommit status of the database 6174 ** connection while this routine is running, then the return value 6175 ** is undefined. 6176 */ 6177 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 6178 6179 /* 6180 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 6181 ** METHOD: sqlite3_stmt 6182 ** 6183 ** ^The sqlite3_db_handle interface returns the [database connection] handle 6184 ** to which a [prepared statement] belongs. ^The [database connection] 6185 ** returned by sqlite3_db_handle is the same [database connection] 6186 ** that was the first argument 6187 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 6188 ** create the statement in the first place. 6189 */ 6190 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 6191 6192 /* 6193 ** CAPI3REF: Return The Filename For A Database Connection 6194 ** METHOD: sqlite3 6195 ** 6196 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename 6197 ** associated with database N of connection D. 6198 ** ^If there is no attached database N on the database 6199 ** connection D, or if database N is a temporary or in-memory database, then 6200 ** this function will return either a NULL pointer or an empty string. 6201 ** 6202 ** ^The string value returned by this routine is owned and managed by 6203 ** the database connection. ^The value will be valid until the database N 6204 ** is [DETACH]-ed or until the database connection closes. 6205 ** 6206 ** ^The filename returned by this function is the output of the 6207 ** xFullPathname method of the [VFS]. ^In other words, the filename 6208 ** will be an absolute pathname, even if the filename used 6209 ** to open the database originally was a URI or relative pathname. 6210 ** 6211 ** If the filename pointer returned by this routine is not NULL, then it 6212 ** can be used as the filename input parameter to these routines: 6213 ** <ul> 6214 ** <li> [sqlite3_uri_parameter()] 6215 ** <li> [sqlite3_uri_boolean()] 6216 ** <li> [sqlite3_uri_int64()] 6217 ** <li> [sqlite3_filename_database()] 6218 ** <li> [sqlite3_filename_journal()] 6219 ** <li> [sqlite3_filename_wal()] 6220 ** </ul> 6221 */ 6222 SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 6223 6224 /* 6225 ** CAPI3REF: Determine if a database is read-only 6226 ** METHOD: sqlite3 6227 ** 6228 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 6229 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 6230 ** the name of a database on connection D. 6231 */ 6232 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 6233 6234 /* 6235 ** CAPI3REF: Determine the transaction state of a database 6236 ** METHOD: sqlite3 6237 ** 6238 ** ^The sqlite3_txn_state(D,S) interface returns the current 6239 ** [transaction state] of schema S in database connection D. ^If S is NULL, 6240 ** then the highest transaction state of any schema on database connection D 6241 ** is returned. Transaction states are (in order of lowest to highest): 6242 ** <ol> 6243 ** <li value="0"> SQLITE_TXN_NONE 6244 ** <li value="1"> SQLITE_TXN_READ 6245 ** <li value="2"> SQLITE_TXN_WRITE 6246 ** </ol> 6247 ** ^If the S argument to sqlite3_txn_state(D,S) is not the name of 6248 ** a valid schema, then -1 is returned. 6249 */ 6250 SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema); 6251 6252 /* 6253 ** CAPI3REF: Allowed return values from [sqlite3_txn_state()] 6254 ** KEYWORDS: {transaction state} 6255 ** 6256 ** These constants define the current transaction state of a database file. 6257 ** ^The [sqlite3_txn_state(D,S)] interface returns one of these 6258 ** constants in order to describe the transaction state of schema S 6259 ** in [database connection] D. 6260 ** 6261 ** <dl> 6262 ** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt> 6263 ** <dd>The SQLITE_TXN_NONE state means that no transaction is currently 6264 ** pending.</dd> 6265 ** 6266 ** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt> 6267 ** <dd>The SQLITE_TXN_READ state means that the database is currently 6268 ** in a read transaction. Content has been read from the database file 6269 ** but nothing in the database file has changed. The transaction state 6270 ** will advanced to SQLITE_TXN_WRITE if any changes occur and there are 6271 ** no other conflicting concurrent write transactions. The transaction 6272 ** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or 6273 ** [COMMIT].</dd> 6274 ** 6275 ** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt> 6276 ** <dd>The SQLITE_TXN_WRITE state means that the database is currently 6277 ** in a write transaction. Content has been written to the database file 6278 ** but has not yet committed. The transaction state will change to 6279 ** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd> 6280 */ 6281 #define SQLITE_TXN_NONE 0 6282 #define SQLITE_TXN_READ 1 6283 #define SQLITE_TXN_WRITE 2 6284 6285 /* 6286 ** CAPI3REF: Find the next prepared statement 6287 ** METHOD: sqlite3 6288 ** 6289 ** ^This interface returns a pointer to the next [prepared statement] after 6290 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 6291 ** then this interface returns a pointer to the first prepared statement 6292 ** associated with the database connection pDb. ^If no prepared statement 6293 ** satisfies the conditions of this routine, it returns NULL. 6294 ** 6295 ** The [database connection] pointer D in a call to 6296 ** [sqlite3_next_stmt(D,S)] must refer to an open database 6297 ** connection and in particular must not be a NULL pointer. 6298 */ 6299 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 6300 6301 /* 6302 ** CAPI3REF: Commit And Rollback Notification Callbacks 6303 ** METHOD: sqlite3 6304 ** 6305 ** ^The sqlite3_commit_hook() interface registers a callback 6306 ** function to be invoked whenever a transaction is [COMMIT | committed]. 6307 ** ^Any callback set by a previous call to sqlite3_commit_hook() 6308 ** for the same database connection is overridden. 6309 ** ^The sqlite3_rollback_hook() interface registers a callback 6310 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 6311 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 6312 ** for the same database connection is overridden. 6313 ** ^The pArg argument is passed through to the callback. 6314 ** ^If the callback on a commit hook function returns non-zero, 6315 ** then the commit is converted into a rollback. 6316 ** 6317 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 6318 ** return the P argument from the previous call of the same function 6319 ** on the same [database connection] D, or NULL for 6320 ** the first call for each function on D. 6321 ** 6322 ** The commit and rollback hook callbacks are not reentrant. 6323 ** The callback implementation must not do anything that will modify 6324 ** the database connection that invoked the callback. Any actions 6325 ** to modify the database connection must be deferred until after the 6326 ** completion of the [sqlite3_step()] call that triggered the commit 6327 ** or rollback hook in the first place. 6328 ** Note that running any other SQL statements, including SELECT statements, 6329 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 6330 ** the database connections for the meaning of "modify" in this paragraph. 6331 ** 6332 ** ^Registering a NULL function disables the callback. 6333 ** 6334 ** ^When the commit hook callback routine returns zero, the [COMMIT] 6335 ** operation is allowed to continue normally. ^If the commit hook 6336 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 6337 ** ^The rollback hook is invoked on a rollback that results from a commit 6338 ** hook returning non-zero, just as it would be with any other rollback. 6339 ** 6340 ** ^For the purposes of this API, a transaction is said to have been 6341 ** rolled back if an explicit "ROLLBACK" statement is executed, or 6342 ** an error or constraint causes an implicit rollback to occur. 6343 ** ^The rollback callback is not invoked if a transaction is 6344 ** automatically rolled back because the database connection is closed. 6345 ** 6346 ** See also the [sqlite3_update_hook()] interface. 6347 */ 6348 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 6349 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 6350 6351 /* 6352 ** CAPI3REF: Data Change Notification Callbacks 6353 ** METHOD: sqlite3 6354 ** 6355 ** ^The sqlite3_update_hook() interface registers a callback function 6356 ** with the [database connection] identified by the first argument 6357 ** to be invoked whenever a row is updated, inserted or deleted in 6358 ** a [rowid table]. 6359 ** ^Any callback set by a previous call to this function 6360 ** for the same database connection is overridden. 6361 ** 6362 ** ^The second argument is a pointer to the function to invoke when a 6363 ** row is updated, inserted or deleted in a rowid table. 6364 ** ^The first argument to the callback is a copy of the third argument 6365 ** to sqlite3_update_hook(). 6366 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 6367 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 6368 ** to be invoked. 6369 ** ^The third and fourth arguments to the callback contain pointers to the 6370 ** database and table name containing the affected row. 6371 ** ^The final callback parameter is the [rowid] of the row. 6372 ** ^In the case of an update, this is the [rowid] after the update takes place. 6373 ** 6374 ** ^(The update hook is not invoked when internal system tables are 6375 ** modified (i.e. sqlite_sequence).)^ 6376 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6377 ** 6378 ** ^In the current implementation, the update hook 6379 ** is not invoked when conflicting rows are deleted because of an 6380 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6381 ** invoked when rows are deleted using the [truncate optimization]. 6382 ** The exceptions defined in this paragraph might change in a future 6383 ** release of SQLite. 6384 ** 6385 ** The update hook implementation must not do anything that will modify 6386 ** the database connection that invoked the update hook. Any actions 6387 ** to modify the database connection must be deferred until after the 6388 ** completion of the [sqlite3_step()] call that triggered the update hook. 6389 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6390 ** database connections for the meaning of "modify" in this paragraph. 6391 ** 6392 ** ^The sqlite3_update_hook(D,C,P) function 6393 ** returns the P argument from the previous call 6394 ** on the same [database connection] D, or NULL for 6395 ** the first call on D. 6396 ** 6397 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6398 ** and [sqlite3_preupdate_hook()] interfaces. 6399 */ 6400 SQLITE_API void *sqlite3_update_hook( 6401 sqlite3*, 6402 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6403 void* 6404 ); 6405 6406 /* 6407 ** CAPI3REF: Enable Or Disable Shared Pager Cache 6408 ** 6409 ** ^(This routine enables or disables the sharing of the database cache 6410 ** and schema data structures between [database connection | connections] 6411 ** to the same database. Sharing is enabled if the argument is true 6412 ** and disabled if the argument is false.)^ 6413 ** 6414 ** ^Cache sharing is enabled and disabled for an entire process. 6415 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6416 ** In prior versions of SQLite, 6417 ** sharing was enabled or disabled for each thread separately. 6418 ** 6419 ** ^(The cache sharing mode set by this interface effects all subsequent 6420 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6421 ** Existing database connections continue to use the sharing mode 6422 ** that was in effect at the time they were opened.)^ 6423 ** 6424 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6425 ** successfully. An [error code] is returned otherwise.)^ 6426 ** 6427 ** ^Shared cache is disabled by default. It is recommended that it stay 6428 ** that way. In other words, do not use this routine. This interface 6429 ** continues to be provided for historical compatibility, but its use is 6430 ** discouraged. Any use of shared cache is discouraged. If shared cache 6431 ** must be used, it is recommended that shared cache only be enabled for 6432 ** individual database connections using the [sqlite3_open_v2()] interface 6433 ** with the [SQLITE_OPEN_SHAREDCACHE] flag. 6434 ** 6435 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6436 ** and will always return SQLITE_MISUSE. On those systems, 6437 ** shared cache mode should be enabled per-database connection via 6438 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6439 ** 6440 ** This interface is threadsafe on processors where writing a 6441 ** 32-bit integer is atomic. 6442 ** 6443 ** See Also: [SQLite Shared-Cache Mode] 6444 */ 6445 SQLITE_API int sqlite3_enable_shared_cache(int); 6446 6447 /* 6448 ** CAPI3REF: Attempt To Free Heap Memory 6449 ** 6450 ** ^The sqlite3_release_memory() interface attempts to free N bytes 6451 ** of heap memory by deallocating non-essential memory allocations 6452 ** held by the database library. Memory used to cache database 6453 ** pages to improve performance is an example of non-essential memory. 6454 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 6455 ** which might be more or less than the amount requested. 6456 ** ^The sqlite3_release_memory() routine is a no-op returning zero 6457 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6458 ** 6459 ** See also: [sqlite3_db_release_memory()] 6460 */ 6461 SQLITE_API int sqlite3_release_memory(int); 6462 6463 /* 6464 ** CAPI3REF: Free Memory Used By A Database Connection 6465 ** METHOD: sqlite3 6466 ** 6467 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6468 ** memory as possible from database connection D. Unlike the 6469 ** [sqlite3_release_memory()] interface, this interface is in effect even 6470 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6471 ** omitted. 6472 ** 6473 ** See also: [sqlite3_release_memory()] 6474 */ 6475 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 6476 6477 /* 6478 ** CAPI3REF: Impose A Limit On Heap Size 6479 ** 6480 ** These interfaces impose limits on the amount of heap memory that will be 6481 ** by all database connections within a single process. 6482 ** 6483 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6484 ** soft limit on the amount of heap memory that may be allocated by SQLite. 6485 ** ^SQLite strives to keep heap memory utilization below the soft heap 6486 ** limit by reducing the number of pages held in the page cache 6487 ** as heap memory usages approaches the limit. 6488 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 6489 ** below the limit, it will exceed the limit rather than generate 6490 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6491 ** is advisory only. 6492 ** 6493 ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of 6494 ** N bytes on the amount of memory that will be allocated. ^The 6495 ** sqlite3_hard_heap_limit64(N) interface is similar to 6496 ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail 6497 ** when the hard heap limit is reached. 6498 ** 6499 ** ^The return value from both sqlite3_soft_heap_limit64() and 6500 ** sqlite3_hard_heap_limit64() is the size of 6501 ** the heap limit prior to the call, or negative in the case of an 6502 ** error. ^If the argument N is negative 6503 ** then no change is made to the heap limit. Hence, the current 6504 ** size of heap limits can be determined by invoking 6505 ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). 6506 ** 6507 ** ^Setting the heap limits to zero disables the heap limiter mechanism. 6508 ** 6509 ** ^The soft heap limit may not be greater than the hard heap limit. 6510 ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) 6511 ** is invoked with a value of N that is greater than the hard heap limit, 6512 ** the the soft heap limit is set to the value of the hard heap limit. 6513 ** ^The soft heap limit is automatically enabled whenever the hard heap 6514 ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and 6515 ** the soft heap limit is outside the range of 1..N, then the soft heap 6516 ** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the 6517 ** hard heap limit is enabled makes the soft heap limit equal to the 6518 ** hard heap limit. 6519 ** 6520 ** The memory allocation limits can also be adjusted using 6521 ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 6522 ** 6523 ** ^(The heap limits are not enforced in the current implementation 6524 ** if one or more of following conditions are true: 6525 ** 6526 ** <ul> 6527 ** <li> The limit value is set to zero. 6528 ** <li> Memory accounting is disabled using a combination of the 6529 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6530 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6531 ** <li> An alternative page cache implementation is specified using 6532 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6533 ** <li> The page cache allocates from its own memory pool supplied 6534 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6535 ** from the heap. 6536 ** </ul>)^ 6537 ** 6538 ** The circumstances under which SQLite will enforce the heap limits may 6539 ** changes in future releases of SQLite. 6540 */ 6541 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6542 SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 6543 6544 /* 6545 ** CAPI3REF: Deprecated Soft Heap Limit Interface 6546 ** DEPRECATED 6547 ** 6548 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6549 ** interface. This routine is provided for historical compatibility 6550 ** only. All new applications should use the 6551 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 6552 */ 6553 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6554 6555 6556 /* 6557 ** CAPI3REF: Extract Metadata About A Column Of A Table 6558 ** METHOD: sqlite3 6559 ** 6560 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6561 ** information about column C of table T in database D 6562 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6563 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 6564 ** the final five arguments with appropriate values if the specified 6565 ** column exists. ^The sqlite3_table_column_metadata() interface returns 6566 ** SQLITE_ERROR if the specified column does not exist. 6567 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6568 ** NULL pointer, then this routine simply checks for the existence of the 6569 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6570 ** does not. If the table name parameter T in a call to 6571 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6572 ** undefined behavior. 6573 ** 6574 ** ^The column is identified by the second, third and fourth parameters to 6575 ** this function. ^(The second parameter is either the name of the database 6576 ** (i.e. "main", "temp", or an attached database) containing the specified 6577 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6578 ** for the table using the same algorithm used by the database engine to 6579 ** resolve unqualified table references. 6580 ** 6581 ** ^The third and fourth parameters to this function are the table and column 6582 ** name of the desired column, respectively. 6583 ** 6584 ** ^Metadata is returned by writing to the memory locations passed as the 5th 6585 ** and subsequent parameters to this function. ^Any of these arguments may be 6586 ** NULL, in which case the corresponding element of metadata is omitted. 6587 ** 6588 ** ^(<blockquote> 6589 ** <table border="1"> 6590 ** <tr><th> Parameter <th> Output<br>Type <th> Description 6591 ** 6592 ** <tr><td> 5th <td> const char* <td> Data type 6593 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6594 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6595 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6596 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6597 ** </table> 6598 ** </blockquote>)^ 6599 ** 6600 ** ^The memory pointed to by the character pointers returned for the 6601 ** declaration type and collation sequence is valid until the next 6602 ** call to any SQLite API function. 6603 ** 6604 ** ^If the specified table is actually a view, an [error code] is returned. 6605 ** 6606 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6607 ** is not a [WITHOUT ROWID] table and an 6608 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6609 ** parameters are set for the explicitly declared column. ^(If there is no 6610 ** [INTEGER PRIMARY KEY] column, then the outputs 6611 ** for the [rowid] are set as follows: 6612 ** 6613 ** <pre> 6614 ** data type: "INTEGER" 6615 ** collation sequence: "BINARY" 6616 ** not null: 0 6617 ** primary key: 1 6618 ** auto increment: 0 6619 ** </pre>)^ 6620 ** 6621 ** ^This function causes all database schemas to be read from disk and 6622 ** parsed, if that has not already been done, and returns an error if 6623 ** any errors are encountered while loading the schema. 6624 */ 6625 SQLITE_API int sqlite3_table_column_metadata( 6626 sqlite3 *db, /* Connection handle */ 6627 const char *zDbName, /* Database name or NULL */ 6628 const char *zTableName, /* Table name */ 6629 const char *zColumnName, /* Column name */ 6630 char const **pzDataType, /* OUTPUT: Declared data type */ 6631 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6632 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6633 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6634 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6635 ); 6636 6637 /* 6638 ** CAPI3REF: Load An Extension 6639 ** METHOD: sqlite3 6640 ** 6641 ** ^This interface loads an SQLite extension library from the named file. 6642 ** 6643 ** ^The sqlite3_load_extension() interface attempts to load an 6644 ** [SQLite extension] library contained in the file zFile. If 6645 ** the file cannot be loaded directly, attempts are made to load 6646 ** with various operating-system specific extensions added. 6647 ** So for example, if "samplelib" cannot be loaded, then names like 6648 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6649 ** be tried also. 6650 ** 6651 ** ^The entry point is zProc. 6652 ** ^(zProc may be 0, in which case SQLite will try to come up with an 6653 ** entry point name on its own. It first tries "sqlite3_extension_init". 6654 ** If that does not work, it constructs a name "sqlite3_X_init" where the 6655 ** X is consists of the lower-case equivalent of all ASCII alphabetic 6656 ** characters in the filename from the last "/" to the first following 6657 ** "." and omitting any initial "lib".)^ 6658 ** ^The sqlite3_load_extension() interface returns 6659 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6660 ** ^If an error occurs and pzErrMsg is not 0, then the 6661 ** [sqlite3_load_extension()] interface shall attempt to 6662 ** fill *pzErrMsg with error message text stored in memory 6663 ** obtained from [sqlite3_malloc()]. The calling function 6664 ** should free this memory by calling [sqlite3_free()]. 6665 ** 6666 ** ^Extension loading must be enabled using 6667 ** [sqlite3_enable_load_extension()] or 6668 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6669 ** prior to calling this API, 6670 ** otherwise an error will be returned. 6671 ** 6672 ** <b>Security warning:</b> It is recommended that the 6673 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6674 ** interface. The use of the [sqlite3_enable_load_extension()] interface 6675 ** should be avoided. This will keep the SQL function [load_extension()] 6676 ** disabled and prevent SQL injections from giving attackers 6677 ** access to extension loading capabilities. 6678 ** 6679 ** See also the [load_extension() SQL function]. 6680 */ 6681 SQLITE_API int sqlite3_load_extension( 6682 sqlite3 *db, /* Load the extension into this database connection */ 6683 const char *zFile, /* Name of the shared library containing extension */ 6684 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6685 char **pzErrMsg /* Put error message here if not 0 */ 6686 ); 6687 6688 /* 6689 ** CAPI3REF: Enable Or Disable Extension Loading 6690 ** METHOD: sqlite3 6691 ** 6692 ** ^So as not to open security holes in older applications that are 6693 ** unprepared to deal with [extension loading], and as a means of disabling 6694 ** [extension loading] while evaluating user-entered SQL, the following API 6695 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6696 ** 6697 ** ^Extension loading is off by default. 6698 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6699 ** to turn extension loading on and call it with onoff==0 to turn 6700 ** it back off again. 6701 ** 6702 ** ^This interface enables or disables both the C-API 6703 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6704 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6705 ** to enable or disable only the C-API.)^ 6706 ** 6707 ** <b>Security warning:</b> It is recommended that extension loading 6708 ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6709 ** rather than this interface, so the [load_extension()] SQL function 6710 ** remains disabled. This will prevent SQL injections from giving attackers 6711 ** access to extension loading capabilities. 6712 */ 6713 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6714 6715 /* 6716 ** CAPI3REF: Automatically Load Statically Linked Extensions 6717 ** 6718 ** ^This interface causes the xEntryPoint() function to be invoked for 6719 ** each new [database connection] that is created. The idea here is that 6720 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6721 ** that is to be automatically loaded into all new database connections. 6722 ** 6723 ** ^(Even though the function prototype shows that xEntryPoint() takes 6724 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 6725 ** arguments and expects an integer result as if the signature of the 6726 ** entry point where as follows: 6727 ** 6728 ** <blockquote><pre> 6729 ** int xEntryPoint( 6730 ** sqlite3 *db, 6731 ** const char **pzErrMsg, 6732 ** const struct sqlite3_api_routines *pThunk 6733 ** ); 6734 ** </pre></blockquote>)^ 6735 ** 6736 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6737 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6738 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6739 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6740 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6741 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6742 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6743 ** 6744 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6745 ** on the list of automatic extensions is a harmless no-op. ^No entry point 6746 ** will be called more than once for each database connection that is opened. 6747 ** 6748 ** See also: [sqlite3_reset_auto_extension()] 6749 ** and [sqlite3_cancel_auto_extension()] 6750 */ 6751 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6752 6753 /* 6754 ** CAPI3REF: Cancel Automatic Extension Loading 6755 ** 6756 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6757 ** initialization routine X that was registered using a prior call to 6758 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6759 ** routine returns 1 if initialization routine X was successfully 6760 ** unregistered and it returns 0 if X was not on the list of initialization 6761 ** routines. 6762 */ 6763 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6764 6765 /* 6766 ** CAPI3REF: Reset Automatic Extension Loading 6767 ** 6768 ** ^This interface disables all automatic extensions previously 6769 ** registered using [sqlite3_auto_extension()]. 6770 */ 6771 SQLITE_API void sqlite3_reset_auto_extension(void); 6772 6773 /* 6774 ** The interface to the virtual-table mechanism is currently considered 6775 ** to be experimental. The interface might change in incompatible ways. 6776 ** If this is a problem for you, do not use the interface at this time. 6777 ** 6778 ** When the virtual-table mechanism stabilizes, we will declare the 6779 ** interface fixed, support it indefinitely, and remove this comment. 6780 */ 6781 6782 /* 6783 ** Structures used by the virtual table interface 6784 */ 6785 typedef struct sqlite3_vtab sqlite3_vtab; 6786 typedef struct sqlite3_index_info sqlite3_index_info; 6787 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6788 typedef struct sqlite3_module sqlite3_module; 6789 6790 /* 6791 ** CAPI3REF: Virtual Table Object 6792 ** KEYWORDS: sqlite3_module {virtual table module} 6793 ** 6794 ** This structure, sometimes called a "virtual table module", 6795 ** defines the implementation of a [virtual table]. 6796 ** This structure consists mostly of methods for the module. 6797 ** 6798 ** ^A virtual table module is created by filling in a persistent 6799 ** instance of this structure and passing a pointer to that instance 6800 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6801 ** ^The registration remains valid until it is replaced by a different 6802 ** module or until the [database connection] closes. The content 6803 ** of this structure must not change while it is registered with 6804 ** any database connection. 6805 */ 6806 struct sqlite3_module { 6807 int iVersion; 6808 int (*xCreate)(sqlite3*, void *pAux, 6809 int argc, const char *const*argv, 6810 sqlite3_vtab **ppVTab, char**); 6811 int (*xConnect)(sqlite3*, void *pAux, 6812 int argc, const char *const*argv, 6813 sqlite3_vtab **ppVTab, char**); 6814 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6815 int (*xDisconnect)(sqlite3_vtab *pVTab); 6816 int (*xDestroy)(sqlite3_vtab *pVTab); 6817 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6818 int (*xClose)(sqlite3_vtab_cursor*); 6819 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6820 int argc, sqlite3_value **argv); 6821 int (*xNext)(sqlite3_vtab_cursor*); 6822 int (*xEof)(sqlite3_vtab_cursor*); 6823 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6824 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6825 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6826 int (*xBegin)(sqlite3_vtab *pVTab); 6827 int (*xSync)(sqlite3_vtab *pVTab); 6828 int (*xCommit)(sqlite3_vtab *pVTab); 6829 int (*xRollback)(sqlite3_vtab *pVTab); 6830 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6831 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6832 void **ppArg); 6833 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6834 /* The methods above are in version 1 of the sqlite_module object. Those 6835 ** below are for version 2 and greater. */ 6836 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6837 int (*xRelease)(sqlite3_vtab *pVTab, int); 6838 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6839 /* The methods above are in versions 1 and 2 of the sqlite_module object. 6840 ** Those below are for version 3 and greater. */ 6841 int (*xShadowName)(const char*); 6842 }; 6843 6844 /* 6845 ** CAPI3REF: Virtual Table Indexing Information 6846 ** KEYWORDS: sqlite3_index_info 6847 ** 6848 ** The sqlite3_index_info structure and its substructures is used as part 6849 ** of the [virtual table] interface to 6850 ** pass information into and receive the reply from the [xBestIndex] 6851 ** method of a [virtual table module]. The fields under **Inputs** are the 6852 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 6853 ** results into the **Outputs** fields. 6854 ** 6855 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 6856 ** 6857 ** <blockquote>column OP expr</blockquote> 6858 ** 6859 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6860 ** stored in aConstraint[].op using one of the 6861 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6862 ** ^(The index of the column is stored in 6863 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6864 ** expr on the right-hand side can be evaluated (and thus the constraint 6865 ** is usable) and false if it cannot.)^ 6866 ** 6867 ** ^The optimizer automatically inverts terms of the form "expr OP column" 6868 ** and makes other simplifications to the WHERE clause in an attempt to 6869 ** get as many WHERE clause terms into the form shown above as possible. 6870 ** ^The aConstraint[] array only reports WHERE clause terms that are 6871 ** relevant to the particular virtual table being queried. 6872 ** 6873 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6874 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 6875 ** 6876 ** The colUsed field indicates which columns of the virtual table may be 6877 ** required by the current scan. Virtual table columns are numbered from 6878 ** zero in the order in which they appear within the CREATE TABLE statement 6879 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6880 ** the corresponding bit is set within the colUsed mask if the column may be 6881 ** required by SQLite. If the table has at least 64 columns and any column 6882 ** to the right of the first 63 is required, then bit 63 of colUsed is also 6883 ** set. In other words, column iCol may be required if the expression 6884 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6885 ** non-zero. 6886 ** 6887 ** The [xBestIndex] method must fill aConstraintUsage[] with information 6888 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 6889 ** the right-hand side of the corresponding aConstraint[] is evaluated 6890 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6891 ** is true, then the constraint is assumed to be fully handled by the 6892 ** virtual table and might not be checked again by the byte code.)^ ^(The 6893 ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag 6894 ** is left in its default setting of false, the constraint will always be 6895 ** checked separately in byte code. If the omit flag is change to true, then 6896 ** the constraint may or may not be checked in byte code. In other words, 6897 ** when the omit flag is true there is no guarantee that the constraint will 6898 ** not be checked again using byte code.)^ 6899 ** 6900 ** ^The idxNum and idxPtr values are recorded and passed into the 6901 ** [xFilter] method. 6902 ** ^[sqlite3_free()] is used to free idxPtr if and only if 6903 ** needToFreeIdxPtr is true. 6904 ** 6905 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6906 ** the correct order to satisfy the ORDER BY clause so that no separate 6907 ** sorting step is required. 6908 ** 6909 ** ^The estimatedCost value is an estimate of the cost of a particular 6910 ** strategy. A cost of N indicates that the cost of the strategy is similar 6911 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 6912 ** indicates that the expense of the operation is similar to that of a 6913 ** binary search on a unique indexed field of an SQLite table with N rows. 6914 ** 6915 ** ^The estimatedRows value is an estimate of the number of rows that 6916 ** will be returned by the strategy. 6917 ** 6918 ** The xBestIndex method may optionally populate the idxFlags field with a 6919 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6920 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6921 ** assumes that the strategy may visit at most one row. 6922 ** 6923 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6924 ** SQLite also assumes that if a call to the xUpdate() method is made as 6925 ** part of the same statement to delete or update a virtual table row and the 6926 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6927 ** any database changes. In other words, if the xUpdate() returns 6928 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6929 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6930 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6931 ** the xUpdate method are automatically rolled back by SQLite. 6932 ** 6933 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6934 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6935 ** If a virtual table extension is 6936 ** used with an SQLite version earlier than 3.8.2, the results of attempting 6937 ** to read or write the estimatedRows field are undefined (but are likely 6938 ** to include crashing the application). The estimatedRows field should 6939 ** therefore only be used if [sqlite3_libversion_number()] returns a 6940 ** value greater than or equal to 3008002. Similarly, the idxFlags field 6941 ** was added for [version 3.9.0] ([dateof:3.9.0]). 6942 ** It may therefore only be used if 6943 ** sqlite3_libversion_number() returns a value greater than or equal to 6944 ** 3009000. 6945 */ 6946 struct sqlite3_index_info { 6947 /* Inputs */ 6948 int nConstraint; /* Number of entries in aConstraint */ 6949 struct sqlite3_index_constraint { 6950 int iColumn; /* Column constrained. -1 for ROWID */ 6951 unsigned char op; /* Constraint operator */ 6952 unsigned char usable; /* True if this constraint is usable */ 6953 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6954 } *aConstraint; /* Table of WHERE clause constraints */ 6955 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6956 struct sqlite3_index_orderby { 6957 int iColumn; /* Column number */ 6958 unsigned char desc; /* True for DESC. False for ASC. */ 6959 } *aOrderBy; /* The ORDER BY clause */ 6960 /* Outputs */ 6961 struct sqlite3_index_constraint_usage { 6962 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6963 unsigned char omit; /* Do not code a test for this constraint */ 6964 } *aConstraintUsage; 6965 int idxNum; /* Number used to identify the index */ 6966 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6967 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6968 int orderByConsumed; /* True if output is already ordered */ 6969 double estimatedCost; /* Estimated cost of using this index */ 6970 /* Fields below are only available in SQLite 3.8.2 and later */ 6971 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6972 /* Fields below are only available in SQLite 3.9.0 and later */ 6973 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6974 /* Fields below are only available in SQLite 3.10.0 and later */ 6975 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6976 }; 6977 6978 /* 6979 ** CAPI3REF: Virtual Table Scan Flags 6980 ** 6981 ** Virtual table implementations are allowed to set the 6982 ** [sqlite3_index_info].idxFlags field to some combination of 6983 ** these bits. 6984 */ 6985 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6986 6987 /* 6988 ** CAPI3REF: Virtual Table Constraint Operator Codes 6989 ** 6990 ** These macros define the allowed values for the 6991 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 6992 ** an operator that is part of a constraint term in the wHERE clause of 6993 ** a query that uses a [virtual table]. 6994 */ 6995 #define SQLITE_INDEX_CONSTRAINT_EQ 2 6996 #define SQLITE_INDEX_CONSTRAINT_GT 4 6997 #define SQLITE_INDEX_CONSTRAINT_LE 8 6998 #define SQLITE_INDEX_CONSTRAINT_LT 16 6999 #define SQLITE_INDEX_CONSTRAINT_GE 32 7000 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 7001 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 7002 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 7003 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 7004 #define SQLITE_INDEX_CONSTRAINT_NE 68 7005 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69 7006 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 7007 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71 7008 #define SQLITE_INDEX_CONSTRAINT_IS 72 7009 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 7010 7011 /* 7012 ** CAPI3REF: Register A Virtual Table Implementation 7013 ** METHOD: sqlite3 7014 ** 7015 ** ^These routines are used to register a new [virtual table module] name. 7016 ** ^Module names must be registered before 7017 ** creating a new [virtual table] using the module and before using a 7018 ** preexisting [virtual table] for the module. 7019 ** 7020 ** ^The module name is registered on the [database connection] specified 7021 ** by the first parameter. ^The name of the module is given by the 7022 ** second parameter. ^The third parameter is a pointer to 7023 ** the implementation of the [virtual table module]. ^The fourth 7024 ** parameter is an arbitrary client data pointer that is passed through 7025 ** into the [xCreate] and [xConnect] methods of the virtual table module 7026 ** when a new virtual table is be being created or reinitialized. 7027 ** 7028 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 7029 ** is a pointer to a destructor for the pClientData. ^SQLite will 7030 ** invoke the destructor function (if it is not NULL) when SQLite 7031 ** no longer needs the pClientData pointer. ^The destructor will also 7032 ** be invoked if the call to sqlite3_create_module_v2() fails. 7033 ** ^The sqlite3_create_module() 7034 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 7035 ** destructor. 7036 ** 7037 ** ^If the third parameter (the pointer to the sqlite3_module object) is 7038 ** NULL then no new module is create and any existing modules with the 7039 ** same name are dropped. 7040 ** 7041 ** See also: [sqlite3_drop_modules()] 7042 */ 7043 SQLITE_API int sqlite3_create_module( 7044 sqlite3 *db, /* SQLite connection to register module with */ 7045 const char *zName, /* Name of the module */ 7046 const sqlite3_module *p, /* Methods for the module */ 7047 void *pClientData /* Client data for xCreate/xConnect */ 7048 ); 7049 SQLITE_API int sqlite3_create_module_v2( 7050 sqlite3 *db, /* SQLite connection to register module with */ 7051 const char *zName, /* Name of the module */ 7052 const sqlite3_module *p, /* Methods for the module */ 7053 void *pClientData, /* Client data for xCreate/xConnect */ 7054 void(*xDestroy)(void*) /* Module destructor function */ 7055 ); 7056 7057 /* 7058 ** CAPI3REF: Remove Unnecessary Virtual Table Implementations 7059 ** METHOD: sqlite3 7060 ** 7061 ** ^The sqlite3_drop_modules(D,L) interface removes all virtual 7062 ** table modules from database connection D except those named on list L. 7063 ** The L parameter must be either NULL or a pointer to an array of pointers 7064 ** to strings where the array is terminated by a single NULL pointer. 7065 ** ^If the L parameter is NULL, then all virtual table modules are removed. 7066 ** 7067 ** See also: [sqlite3_create_module()] 7068 */ 7069 SQLITE_API int sqlite3_drop_modules( 7070 sqlite3 *db, /* Remove modules from this connection */ 7071 const char **azKeep /* Except, do not remove the ones named here */ 7072 ); 7073 7074 /* 7075 ** CAPI3REF: Virtual Table Instance Object 7076 ** KEYWORDS: sqlite3_vtab 7077 ** 7078 ** Every [virtual table module] implementation uses a subclass 7079 ** of this object to describe a particular instance 7080 ** of the [virtual table]. Each subclass will 7081 ** be tailored to the specific needs of the module implementation. 7082 ** The purpose of this superclass is to define certain fields that are 7083 ** common to all module implementations. 7084 ** 7085 ** ^Virtual tables methods can set an error message by assigning a 7086 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 7087 ** take care that any prior string is freed by a call to [sqlite3_free()] 7088 ** prior to assigning a new string to zErrMsg. ^After the error message 7089 ** is delivered up to the client application, the string will be automatically 7090 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 7091 */ 7092 struct sqlite3_vtab { 7093 const sqlite3_module *pModule; /* The module for this virtual table */ 7094 int nRef; /* Number of open cursors */ 7095 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 7096 /* Virtual table implementations will typically add additional fields */ 7097 }; 7098 7099 /* 7100 ** CAPI3REF: Virtual Table Cursor Object 7101 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 7102 ** 7103 ** Every [virtual table module] implementation uses a subclass of the 7104 ** following structure to describe cursors that point into the 7105 ** [virtual table] and are used 7106 ** to loop through the virtual table. Cursors are created using the 7107 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 7108 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 7109 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 7110 ** of the module. Each module implementation will define 7111 ** the content of a cursor structure to suit its own needs. 7112 ** 7113 ** This superclass exists in order to define fields of the cursor that 7114 ** are common to all implementations. 7115 */ 7116 struct sqlite3_vtab_cursor { 7117 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 7118 /* Virtual table implementations will typically add additional fields */ 7119 }; 7120 7121 /* 7122 ** CAPI3REF: Declare The Schema Of A Virtual Table 7123 ** 7124 ** ^The [xCreate] and [xConnect] methods of a 7125 ** [virtual table module] call this interface 7126 ** to declare the format (the names and datatypes of the columns) of 7127 ** the virtual tables they implement. 7128 */ 7129 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 7130 7131 /* 7132 ** CAPI3REF: Overload A Function For A Virtual Table 7133 ** METHOD: sqlite3 7134 ** 7135 ** ^(Virtual tables can provide alternative implementations of functions 7136 ** using the [xFindFunction] method of the [virtual table module]. 7137 ** But global versions of those functions 7138 ** must exist in order to be overloaded.)^ 7139 ** 7140 ** ^(This API makes sure a global version of a function with a particular 7141 ** name and number of parameters exists. If no such function exists 7142 ** before this API is called, a new function is created.)^ ^The implementation 7143 ** of the new function always causes an exception to be thrown. So 7144 ** the new function is not good for anything by itself. Its only 7145 ** purpose is to be a placeholder function that can be overloaded 7146 ** by a [virtual table]. 7147 */ 7148 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 7149 7150 /* 7151 ** The interface to the virtual-table mechanism defined above (back up 7152 ** to a comment remarkably similar to this one) is currently considered 7153 ** to be experimental. The interface might change in incompatible ways. 7154 ** If this is a problem for you, do not use the interface at this time. 7155 ** 7156 ** When the virtual-table mechanism stabilizes, we will declare the 7157 ** interface fixed, support it indefinitely, and remove this comment. 7158 */ 7159 7160 /* 7161 ** CAPI3REF: A Handle To An Open BLOB 7162 ** KEYWORDS: {BLOB handle} {BLOB handles} 7163 ** 7164 ** An instance of this object represents an open BLOB on which 7165 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 7166 ** ^Objects of this type are created by [sqlite3_blob_open()] 7167 ** and destroyed by [sqlite3_blob_close()]. 7168 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 7169 ** can be used to read or write small subsections of the BLOB. 7170 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 7171 */ 7172 typedef struct sqlite3_blob sqlite3_blob; 7173 7174 /* 7175 ** CAPI3REF: Open A BLOB For Incremental I/O 7176 ** METHOD: sqlite3 7177 ** CONSTRUCTOR: sqlite3_blob 7178 ** 7179 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 7180 ** in row iRow, column zColumn, table zTable in database zDb; 7181 ** in other words, the same BLOB that would be selected by: 7182 ** 7183 ** <pre> 7184 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 7185 ** </pre>)^ 7186 ** 7187 ** ^(Parameter zDb is not the filename that contains the database, but 7188 ** rather the symbolic name of the database. For attached databases, this is 7189 ** the name that appears after the AS keyword in the [ATTACH] statement. 7190 ** For the main database file, the database name is "main". For TEMP 7191 ** tables, the database name is "temp".)^ 7192 ** 7193 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 7194 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 7195 ** read-only access. 7196 ** 7197 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 7198 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 7199 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 7200 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 7201 ** on *ppBlob after this function it returns. 7202 ** 7203 ** This function fails with SQLITE_ERROR if any of the following are true: 7204 ** <ul> 7205 ** <li> ^(Database zDb does not exist)^, 7206 ** <li> ^(Table zTable does not exist within database zDb)^, 7207 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 7208 ** <li> ^(Column zColumn does not exist)^, 7209 ** <li> ^(Row iRow is not present in the table)^, 7210 ** <li> ^(The specified column of row iRow contains a value that is not 7211 ** a TEXT or BLOB value)^, 7212 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 7213 ** constraint and the blob is being opened for read/write access)^, 7214 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 7215 ** column zColumn is part of a [child key] definition and the blob is 7216 ** being opened for read/write access)^. 7217 ** </ul> 7218 ** 7219 ** ^Unless it returns SQLITE_MISUSE, this function sets the 7220 ** [database connection] error code and message accessible via 7221 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7222 ** 7223 ** A BLOB referenced by sqlite3_blob_open() may be read using the 7224 ** [sqlite3_blob_read()] interface and modified by using 7225 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 7226 ** different row of the same table using the [sqlite3_blob_reopen()] 7227 ** interface. However, the column, table, or database of a [BLOB handle] 7228 ** cannot be changed after the [BLOB handle] is opened. 7229 ** 7230 ** ^(If the row that a BLOB handle points to is modified by an 7231 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 7232 ** then the BLOB handle is marked as "expired". 7233 ** This is true if any column of the row is changed, even a column 7234 ** other than the one the BLOB handle is open on.)^ 7235 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 7236 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 7237 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 7238 ** rolled back by the expiration of the BLOB. Such changes will eventually 7239 ** commit if the transaction continues to completion.)^ 7240 ** 7241 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 7242 ** the opened blob. ^The size of a blob may not be changed by this 7243 ** interface. Use the [UPDATE] SQL command to change the size of a 7244 ** blob. 7245 ** 7246 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 7247 ** and the built-in [zeroblob] SQL function may be used to create a 7248 ** zero-filled blob to read or write using the incremental-blob interface. 7249 ** 7250 ** To avoid a resource leak, every open [BLOB handle] should eventually 7251 ** be released by a call to [sqlite3_blob_close()]. 7252 ** 7253 ** See also: [sqlite3_blob_close()], 7254 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 7255 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 7256 */ 7257 SQLITE_API int sqlite3_blob_open( 7258 sqlite3*, 7259 const char *zDb, 7260 const char *zTable, 7261 const char *zColumn, 7262 sqlite3_int64 iRow, 7263 int flags, 7264 sqlite3_blob **ppBlob 7265 ); 7266 7267 /* 7268 ** CAPI3REF: Move a BLOB Handle to a New Row 7269 ** METHOD: sqlite3_blob 7270 ** 7271 ** ^This function is used to move an existing [BLOB handle] so that it points 7272 ** to a different row of the same database table. ^The new row is identified 7273 ** by the rowid value passed as the second argument. Only the row can be 7274 ** changed. ^The database, table and column on which the blob handle is open 7275 ** remain the same. Moving an existing [BLOB handle] to a new row is 7276 ** faster than closing the existing handle and opening a new one. 7277 ** 7278 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 7279 ** it must exist and there must be either a blob or text value stored in 7280 ** the nominated column.)^ ^If the new row is not present in the table, or if 7281 ** it does not contain a blob or text value, or if another error occurs, an 7282 ** SQLite error code is returned and the blob handle is considered aborted. 7283 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 7284 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 7285 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 7286 ** always returns zero. 7287 ** 7288 ** ^This function sets the database handle error code and message. 7289 */ 7290 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 7291 7292 /* 7293 ** CAPI3REF: Close A BLOB Handle 7294 ** DESTRUCTOR: sqlite3_blob 7295 ** 7296 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 7297 ** unconditionally. Even if this routine returns an error code, the 7298 ** handle is still closed.)^ 7299 ** 7300 ** ^If the blob handle being closed was opened for read-write access, and if 7301 ** the database is in auto-commit mode and there are no other open read-write 7302 ** blob handles or active write statements, the current transaction is 7303 ** committed. ^If an error occurs while committing the transaction, an error 7304 ** code is returned and the transaction rolled back. 7305 ** 7306 ** Calling this function with an argument that is not a NULL pointer or an 7307 ** open blob handle results in undefined behaviour. ^Calling this routine 7308 ** with a null pointer (such as would be returned by a failed call to 7309 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 7310 ** is passed a valid open blob handle, the values returned by the 7311 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 7312 */ 7313 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 7314 7315 /* 7316 ** CAPI3REF: Return The Size Of An Open BLOB 7317 ** METHOD: sqlite3_blob 7318 ** 7319 ** ^Returns the size in bytes of the BLOB accessible via the 7320 ** successfully opened [BLOB handle] in its only argument. ^The 7321 ** incremental blob I/O routines can only read or overwriting existing 7322 ** blob content; they cannot change the size of a blob. 7323 ** 7324 ** This routine only works on a [BLOB handle] which has been created 7325 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7326 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7327 ** to this routine results in undefined and probably undesirable behavior. 7328 */ 7329 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 7330 7331 /* 7332 ** CAPI3REF: Read Data From A BLOB Incrementally 7333 ** METHOD: sqlite3_blob 7334 ** 7335 ** ^(This function is used to read data from an open [BLOB handle] into a 7336 ** caller-supplied buffer. N bytes of data are copied into buffer Z 7337 ** from the open BLOB, starting at offset iOffset.)^ 7338 ** 7339 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7340 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 7341 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 7342 ** ^The size of the blob (and hence the maximum value of N+iOffset) 7343 ** can be determined using the [sqlite3_blob_bytes()] interface. 7344 ** 7345 ** ^An attempt to read from an expired [BLOB handle] fails with an 7346 ** error code of [SQLITE_ABORT]. 7347 ** 7348 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 7349 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7350 ** 7351 ** This routine only works on a [BLOB handle] which has been created 7352 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7353 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7354 ** to this routine results in undefined and probably undesirable behavior. 7355 ** 7356 ** See also: [sqlite3_blob_write()]. 7357 */ 7358 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 7359 7360 /* 7361 ** CAPI3REF: Write Data Into A BLOB Incrementally 7362 ** METHOD: sqlite3_blob 7363 ** 7364 ** ^(This function is used to write data into an open [BLOB handle] from a 7365 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 7366 ** into the open BLOB, starting at offset iOffset.)^ 7367 ** 7368 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 7369 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7370 ** ^Unless SQLITE_MISUSE is returned, this function sets the 7371 ** [database connection] error code and message accessible via 7372 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7373 ** 7374 ** ^If the [BLOB handle] passed as the first argument was not opened for 7375 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 7376 ** this function returns [SQLITE_READONLY]. 7377 ** 7378 ** This function may only modify the contents of the BLOB; it is 7379 ** not possible to increase the size of a BLOB using this API. 7380 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7381 ** [SQLITE_ERROR] is returned and no data is written. The size of the 7382 ** BLOB (and hence the maximum value of N+iOffset) can be determined 7383 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 7384 ** than zero [SQLITE_ERROR] is returned and no data is written. 7385 ** 7386 ** ^An attempt to write to an expired [BLOB handle] fails with an 7387 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 7388 ** before the [BLOB handle] expired are not rolled back by the 7389 ** expiration of the handle, though of course those changes might 7390 ** have been overwritten by the statement that expired the BLOB handle 7391 ** or by other independent statements. 7392 ** 7393 ** This routine only works on a [BLOB handle] which has been created 7394 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7395 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7396 ** to this routine results in undefined and probably undesirable behavior. 7397 ** 7398 ** See also: [sqlite3_blob_read()]. 7399 */ 7400 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7401 7402 /* 7403 ** CAPI3REF: Virtual File System Objects 7404 ** 7405 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7406 ** that SQLite uses to interact 7407 ** with the underlying operating system. Most SQLite builds come with a 7408 ** single default VFS that is appropriate for the host computer. 7409 ** New VFSes can be registered and existing VFSes can be unregistered. 7410 ** The following interfaces are provided. 7411 ** 7412 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7413 ** ^Names are case sensitive. 7414 ** ^Names are zero-terminated UTF-8 strings. 7415 ** ^If there is no match, a NULL pointer is returned. 7416 ** ^If zVfsName is NULL then the default VFS is returned. 7417 ** 7418 ** ^New VFSes are registered with sqlite3_vfs_register(). 7419 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7420 ** ^The same VFS can be registered multiple times without injury. 7421 ** ^To make an existing VFS into the default VFS, register it again 7422 ** with the makeDflt flag set. If two different VFSes with the 7423 ** same name are registered, the behavior is undefined. If a 7424 ** VFS is registered with a name that is NULL or an empty string, 7425 ** then the behavior is undefined. 7426 ** 7427 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7428 ** ^(If the default VFS is unregistered, another VFS is chosen as 7429 ** the default. The choice for the new VFS is arbitrary.)^ 7430 */ 7431 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 7432 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 7433 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 7434 7435 /* 7436 ** CAPI3REF: Mutexes 7437 ** 7438 ** The SQLite core uses these routines for thread 7439 ** synchronization. Though they are intended for internal 7440 ** use by SQLite, code that links against SQLite is 7441 ** permitted to use any of these routines. 7442 ** 7443 ** The SQLite source code contains multiple implementations 7444 ** of these mutex routines. An appropriate implementation 7445 ** is selected automatically at compile-time. The following 7446 ** implementations are available in the SQLite core: 7447 ** 7448 ** <ul> 7449 ** <li> SQLITE_MUTEX_PTHREADS 7450 ** <li> SQLITE_MUTEX_W32 7451 ** <li> SQLITE_MUTEX_NOOP 7452 ** </ul> 7453 ** 7454 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 7455 ** that does no real locking and is appropriate for use in 7456 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7457 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7458 ** and Windows. 7459 ** 7460 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 7461 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 7462 ** implementation is included with the library. In this case the 7463 ** application must supply a custom mutex implementation using the 7464 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 7465 ** before calling sqlite3_initialize() or any other public sqlite3_ 7466 ** function that calls sqlite3_initialize(). 7467 ** 7468 ** ^The sqlite3_mutex_alloc() routine allocates a new 7469 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 7470 ** routine returns NULL if it is unable to allocate the requested 7471 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 7472 ** integer constants: 7473 ** 7474 ** <ul> 7475 ** <li> SQLITE_MUTEX_FAST 7476 ** <li> SQLITE_MUTEX_RECURSIVE 7477 ** <li> SQLITE_MUTEX_STATIC_MAIN 7478 ** <li> SQLITE_MUTEX_STATIC_MEM 7479 ** <li> SQLITE_MUTEX_STATIC_OPEN 7480 ** <li> SQLITE_MUTEX_STATIC_PRNG 7481 ** <li> SQLITE_MUTEX_STATIC_LRU 7482 ** <li> SQLITE_MUTEX_STATIC_PMEM 7483 ** <li> SQLITE_MUTEX_STATIC_APP1 7484 ** <li> SQLITE_MUTEX_STATIC_APP2 7485 ** <li> SQLITE_MUTEX_STATIC_APP3 7486 ** <li> SQLITE_MUTEX_STATIC_VFS1 7487 ** <li> SQLITE_MUTEX_STATIC_VFS2 7488 ** <li> SQLITE_MUTEX_STATIC_VFS3 7489 ** </ul> 7490 ** 7491 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 7492 ** cause sqlite3_mutex_alloc() to create 7493 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 7494 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 7495 ** The mutex implementation does not need to make a distinction 7496 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 7497 ** not want to. SQLite will only request a recursive mutex in 7498 ** cases where it really needs one. If a faster non-recursive mutex 7499 ** implementation is available on the host platform, the mutex subsystem 7500 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 7501 ** 7502 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 7503 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 7504 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 7505 ** used by the current version of SQLite. Future versions of SQLite 7506 ** may add additional static mutexes. Static mutexes are for internal 7507 ** use by SQLite only. Applications that use SQLite mutexes should 7508 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 7509 ** SQLITE_MUTEX_RECURSIVE. 7510 ** 7511 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 7512 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 7513 ** returns a different mutex on every call. ^For the static 7514 ** mutex types, the same mutex is returned on every call that has 7515 ** the same type number. 7516 ** 7517 ** ^The sqlite3_mutex_free() routine deallocates a previously 7518 ** allocated dynamic mutex. Attempting to deallocate a static 7519 ** mutex results in undefined behavior. 7520 ** 7521 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 7522 ** to enter a mutex. ^If another thread is already within the mutex, 7523 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 7524 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 7525 ** upon successful entry. ^(Mutexes created using 7526 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 7527 ** In such cases, the 7528 ** mutex must be exited an equal number of times before another thread 7529 ** can enter.)^ If the same thread tries to enter any mutex other 7530 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 7531 ** 7532 ** ^(Some systems (for example, Windows 95) do not support the operation 7533 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 7534 ** will always return SQLITE_BUSY. The SQLite core only ever uses 7535 ** sqlite3_mutex_try() as an optimization so this is acceptable 7536 ** behavior.)^ 7537 ** 7538 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 7539 ** previously entered by the same thread. The behavior 7540 ** is undefined if the mutex is not currently entered by the 7541 ** calling thread or is not currently allocated. 7542 ** 7543 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 7544 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 7545 ** behave as no-ops. 7546 ** 7547 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7548 */ 7549 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 7550 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 7551 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 7552 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 7553 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 7554 7555 /* 7556 ** CAPI3REF: Mutex Methods Object 7557 ** 7558 ** An instance of this structure defines the low-level routines 7559 ** used to allocate and use mutexes. 7560 ** 7561 ** Usually, the default mutex implementations provided by SQLite are 7562 ** sufficient, however the application has the option of substituting a custom 7563 ** implementation for specialized deployments or systems for which SQLite 7564 ** does not provide a suitable implementation. In this case, the application 7565 ** creates and populates an instance of this structure to pass 7566 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7567 ** Additionally, an instance of this structure can be used as an 7568 ** output variable when querying the system for the current mutex 7569 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7570 ** 7571 ** ^The xMutexInit method defined by this structure is invoked as 7572 ** part of system initialization by the sqlite3_initialize() function. 7573 ** ^The xMutexInit routine is called by SQLite exactly once for each 7574 ** effective call to [sqlite3_initialize()]. 7575 ** 7576 ** ^The xMutexEnd method defined by this structure is invoked as 7577 ** part of system shutdown by the sqlite3_shutdown() function. The 7578 ** implementation of this method is expected to release all outstanding 7579 ** resources obtained by the mutex methods implementation, especially 7580 ** those obtained by the xMutexInit method. ^The xMutexEnd() 7581 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7582 ** 7583 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7584 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7585 ** xMutexNotheld) implement the following interfaces (respectively): 7586 ** 7587 ** <ul> 7588 ** <li> [sqlite3_mutex_alloc()] </li> 7589 ** <li> [sqlite3_mutex_free()] </li> 7590 ** <li> [sqlite3_mutex_enter()] </li> 7591 ** <li> [sqlite3_mutex_try()] </li> 7592 ** <li> [sqlite3_mutex_leave()] </li> 7593 ** <li> [sqlite3_mutex_held()] </li> 7594 ** <li> [sqlite3_mutex_notheld()] </li> 7595 ** </ul>)^ 7596 ** 7597 ** The only difference is that the public sqlite3_XXX functions enumerated 7598 ** above silently ignore any invocations that pass a NULL pointer instead 7599 ** of a valid mutex handle. The implementations of the methods defined 7600 ** by this structure are not required to handle this case. The results 7601 ** of passing a NULL pointer instead of a valid mutex handle are undefined 7602 ** (i.e. it is acceptable to provide an implementation that segfaults if 7603 ** it is passed a NULL pointer). 7604 ** 7605 ** The xMutexInit() method must be threadsafe. It must be harmless to 7606 ** invoke xMutexInit() multiple times within the same process and without 7607 ** intervening calls to xMutexEnd(). Second and subsequent calls to 7608 ** xMutexInit() must be no-ops. 7609 ** 7610 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7611 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7612 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7613 ** memory allocation for a fast or recursive mutex. 7614 ** 7615 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7616 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7617 ** If xMutexInit fails in any way, it is expected to clean up after itself 7618 ** prior to returning. 7619 */ 7620 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7621 struct sqlite3_mutex_methods { 7622 int (*xMutexInit)(void); 7623 int (*xMutexEnd)(void); 7624 sqlite3_mutex *(*xMutexAlloc)(int); 7625 void (*xMutexFree)(sqlite3_mutex *); 7626 void (*xMutexEnter)(sqlite3_mutex *); 7627 int (*xMutexTry)(sqlite3_mutex *); 7628 void (*xMutexLeave)(sqlite3_mutex *); 7629 int (*xMutexHeld)(sqlite3_mutex *); 7630 int (*xMutexNotheld)(sqlite3_mutex *); 7631 }; 7632 7633 /* 7634 ** CAPI3REF: Mutex Verification Routines 7635 ** 7636 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7637 ** are intended for use inside assert() statements. The SQLite core 7638 ** never uses these routines except inside an assert() and applications 7639 ** are advised to follow the lead of the core. The SQLite core only 7640 ** provides implementations for these routines when it is compiled 7641 ** with the SQLITE_DEBUG flag. External mutex implementations 7642 ** are only required to provide these routines if SQLITE_DEBUG is 7643 ** defined and if NDEBUG is not defined. 7644 ** 7645 ** These routines should return true if the mutex in their argument 7646 ** is held or not held, respectively, by the calling thread. 7647 ** 7648 ** The implementation is not required to provide versions of these 7649 ** routines that actually work. If the implementation does not provide working 7650 ** versions of these routines, it should at least provide stubs that always 7651 ** return true so that one does not get spurious assertion failures. 7652 ** 7653 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 7654 ** the routine should return 1. This seems counter-intuitive since 7655 ** clearly the mutex cannot be held if it does not exist. But 7656 ** the reason the mutex does not exist is because the build is not 7657 ** using mutexes. And we do not want the assert() containing the 7658 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 7659 ** the appropriate thing to do. The sqlite3_mutex_notheld() 7660 ** interface should also return 1 when given a NULL pointer. 7661 */ 7662 #ifndef NDEBUG 7663 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 7664 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 7665 #endif 7666 7667 /* 7668 ** CAPI3REF: Mutex Types 7669 ** 7670 ** The [sqlite3_mutex_alloc()] interface takes a single argument 7671 ** which is one of these integer constants. 7672 ** 7673 ** The set of static mutexes may change from one SQLite release to the 7674 ** next. Applications that override the built-in mutex logic must be 7675 ** prepared to accommodate additional static mutexes. 7676 */ 7677 #define SQLITE_MUTEX_FAST 0 7678 #define SQLITE_MUTEX_RECURSIVE 1 7679 #define SQLITE_MUTEX_STATIC_MAIN 2 7680 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7681 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7682 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7683 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7684 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7685 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7686 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7687 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7688 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7689 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7690 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7691 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7692 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7693 7694 /* Legacy compatibility: */ 7695 #define SQLITE_MUTEX_STATIC_MASTER 2 7696 7697 7698 /* 7699 ** CAPI3REF: Retrieve the mutex for a database connection 7700 ** METHOD: sqlite3 7701 ** 7702 ** ^This interface returns a pointer the [sqlite3_mutex] object that 7703 ** serializes access to the [database connection] given in the argument 7704 ** when the [threading mode] is Serialized. 7705 ** ^If the [threading mode] is Single-thread or Multi-thread then this 7706 ** routine returns a NULL pointer. 7707 */ 7708 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7709 7710 /* 7711 ** CAPI3REF: Low-Level Control Of Database Files 7712 ** METHOD: sqlite3 7713 ** KEYWORDS: {file control} 7714 ** 7715 ** ^The [sqlite3_file_control()] interface makes a direct call to the 7716 ** xFileControl method for the [sqlite3_io_methods] object associated 7717 ** with a particular database identified by the second argument. ^The 7718 ** name of the database is "main" for the main database or "temp" for the 7719 ** TEMP database, or the name that appears after the AS keyword for 7720 ** databases that are added using the [ATTACH] SQL command. 7721 ** ^A NULL pointer can be used in place of "main" to refer to the 7722 ** main database file. 7723 ** ^The third and fourth parameters to this routine 7724 ** are passed directly through to the second and third parameters of 7725 ** the xFileControl method. ^The return value of the xFileControl 7726 ** method becomes the return value of this routine. 7727 ** 7728 ** A few opcodes for [sqlite3_file_control()] are handled directly 7729 ** by the SQLite core and never invoke the 7730 ** sqlite3_io_methods.xFileControl method. 7731 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7732 ** a pointer to the underlying [sqlite3_file] object to be written into 7733 ** the space pointed to by the 4th parameter. The 7734 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 7735 ** the [sqlite3_file] object associated with the journal file instead of 7736 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 7737 ** a pointer to the underlying [sqlite3_vfs] object for the file. 7738 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 7739 ** from the pager. 7740 ** 7741 ** ^If the second parameter (zDbName) does not match the name of any 7742 ** open database file, then SQLITE_ERROR is returned. ^This error 7743 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 7744 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 7745 ** also return SQLITE_ERROR. There is no way to distinguish between 7746 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7747 ** xFileControl method. 7748 ** 7749 ** See also: [file control opcodes] 7750 */ 7751 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7752 7753 /* 7754 ** CAPI3REF: Testing Interface 7755 ** 7756 ** ^The sqlite3_test_control() interface is used to read out internal 7757 ** state of SQLite and to inject faults into SQLite for testing 7758 ** purposes. ^The first parameter is an operation code that determines 7759 ** the number, meaning, and operation of all subsequent parameters. 7760 ** 7761 ** This interface is not for use by applications. It exists solely 7762 ** for verifying the correct operation of the SQLite library. Depending 7763 ** on how the SQLite library is compiled, this interface might not exist. 7764 ** 7765 ** The details of the operation codes, their meanings, the parameters 7766 ** they take, and what they do are all subject to change without notice. 7767 ** Unlike most of the SQLite API, this function is not guaranteed to 7768 ** operate consistently from one release to the next. 7769 */ 7770 SQLITE_API int sqlite3_test_control(int op, ...); 7771 7772 /* 7773 ** CAPI3REF: Testing Interface Operation Codes 7774 ** 7775 ** These constants are the valid operation code parameters used 7776 ** as the first argument to [sqlite3_test_control()]. 7777 ** 7778 ** These parameters and their meanings are subject to change 7779 ** without notice. These values are for testing purposes only. 7780 ** Applications should not use any of these parameters or the 7781 ** [sqlite3_test_control()] interface. 7782 */ 7783 #define SQLITE_TESTCTRL_FIRST 5 7784 #define SQLITE_TESTCTRL_PRNG_SAVE 5 7785 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 7786 #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 7787 #define SQLITE_TESTCTRL_BITVEC_TEST 8 7788 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 7789 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7790 #define SQLITE_TESTCTRL_PENDING_BYTE 11 7791 #define SQLITE_TESTCTRL_ASSERT 12 7792 #define SQLITE_TESTCTRL_ALWAYS 13 7793 #define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */ 7794 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7795 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7796 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7797 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 7798 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7799 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7800 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7801 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7802 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7803 #define SQLITE_TESTCTRL_BYTEORDER 22 7804 #define SQLITE_TESTCTRL_ISINIT 23 7805 #define SQLITE_TESTCTRL_SORTER_MMAP 24 7806 #define SQLITE_TESTCTRL_IMPOSTER 25 7807 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7808 #define SQLITE_TESTCTRL_RESULT_INTREAL 27 7809 #define SQLITE_TESTCTRL_PRNG_SEED 28 7810 #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 7811 #define SQLITE_TESTCTRL_SEEK_COUNT 30 7812 #define SQLITE_TESTCTRL_TRACEFLAGS 31 7813 #define SQLITE_TESTCTRL_TUNE 32 7814 #define SQLITE_TESTCTRL_LAST 32 /* Largest TESTCTRL */ 7815 7816 /* 7817 ** CAPI3REF: SQL Keyword Checking 7818 ** 7819 ** These routines provide access to the set of SQL language keywords 7820 ** recognized by SQLite. Applications can uses these routines to determine 7821 ** whether or not a specific identifier needs to be escaped (for example, 7822 ** by enclosing in double-quotes) so as not to confuse the parser. 7823 ** 7824 ** The sqlite3_keyword_count() interface returns the number of distinct 7825 ** keywords understood by SQLite. 7826 ** 7827 ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 7828 ** makes *Z point to that keyword expressed as UTF8 and writes the number 7829 ** of bytes in the keyword into *L. The string that *Z points to is not 7830 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 7831 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 7832 ** or L are NULL or invalid pointers then calls to 7833 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 7834 ** 7835 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 7836 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 7837 ** if it is and zero if not. 7838 ** 7839 ** The parser used by SQLite is forgiving. It is often possible to use 7840 ** a keyword as an identifier as long as such use does not result in a 7841 ** parsing ambiguity. For example, the statement 7842 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 7843 ** creates a new table named "BEGIN" with three columns named 7844 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 7845 ** using keywords as identifiers. Common techniques used to avoid keyword 7846 ** name collisions include: 7847 ** <ul> 7848 ** <li> Put all identifier names inside double-quotes. This is the official 7849 ** SQL way to escape identifier names. 7850 ** <li> Put identifier names inside [...]. This is not standard SQL, 7851 ** but it is what SQL Server does and so lots of programmers use this 7852 ** technique. 7853 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start 7854 ** with "Z". 7855 ** <li> Include a digit somewhere in every identifier name. 7856 ** </ul> 7857 ** 7858 ** Note that the number of keywords understood by SQLite can depend on 7859 ** compile-time options. For example, "VACUUM" is not a keyword if 7860 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 7861 ** new keywords may be added to future releases of SQLite. 7862 */ 7863 SQLITE_API int sqlite3_keyword_count(void); 7864 SQLITE_API int sqlite3_keyword_name(int,const char**,int*); 7865 SQLITE_API int sqlite3_keyword_check(const char*,int); 7866 7867 /* 7868 ** CAPI3REF: Dynamic String Object 7869 ** KEYWORDS: {dynamic string} 7870 ** 7871 ** An instance of the sqlite3_str object contains a dynamically-sized 7872 ** string under construction. 7873 ** 7874 ** The lifecycle of an sqlite3_str object is as follows: 7875 ** <ol> 7876 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 7877 ** <li> ^Text is appended to the sqlite3_str object using various 7878 ** methods, such as [sqlite3_str_appendf()]. 7879 ** <li> ^The sqlite3_str object is destroyed and the string it created 7880 ** is returned using the [sqlite3_str_finish()] interface. 7881 ** </ol> 7882 */ 7883 typedef struct sqlite3_str sqlite3_str; 7884 7885 /* 7886 ** CAPI3REF: Create A New Dynamic String Object 7887 ** CONSTRUCTOR: sqlite3_str 7888 ** 7889 ** ^The [sqlite3_str_new(D)] interface allocates and initializes 7890 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 7891 ** [sqlite3_str_new()] must be freed by a subsequent call to 7892 ** [sqlite3_str_finish(X)]. 7893 ** 7894 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 7895 ** valid [sqlite3_str] object, though in the event of an out-of-memory 7896 ** error the returned object might be a special singleton that will 7897 ** silently reject new text, always return SQLITE_NOMEM from 7898 ** [sqlite3_str_errcode()], always return 0 for 7899 ** [sqlite3_str_length()], and always return NULL from 7900 ** [sqlite3_str_finish(X)]. It is always safe to use the value 7901 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 7902 ** to any of the other [sqlite3_str] methods. 7903 ** 7904 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 7905 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 7906 ** length of the string contained in the [sqlite3_str] object will be 7907 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 7908 ** of [SQLITE_MAX_LENGTH]. 7909 */ 7910 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*); 7911 7912 /* 7913 ** CAPI3REF: Finalize A Dynamic String 7914 ** DESTRUCTOR: sqlite3_str 7915 ** 7916 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 7917 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 7918 ** that contains the constructed string. The calling application should 7919 ** pass the returned value to [sqlite3_free()] to avoid a memory leak. 7920 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 7921 ** errors were encountered during construction of the string. ^The 7922 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 7923 ** string in [sqlite3_str] object X is zero bytes long. 7924 */ 7925 SQLITE_API char *sqlite3_str_finish(sqlite3_str*); 7926 7927 /* 7928 ** CAPI3REF: Add Content To A Dynamic String 7929 ** METHOD: sqlite3_str 7930 ** 7931 ** These interfaces add content to an sqlite3_str object previously obtained 7932 ** from [sqlite3_str_new()]. 7933 ** 7934 ** ^The [sqlite3_str_appendf(X,F,...)] and 7935 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 7936 ** functionality of SQLite to append formatted text onto the end of 7937 ** [sqlite3_str] object X. 7938 ** 7939 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 7940 ** onto the end of the [sqlite3_str] object X. N must be non-negative. 7941 ** S must contain at least N non-zero bytes of content. To append a 7942 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 7943 ** method instead. 7944 ** 7945 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 7946 ** zero-terminated string S onto the end of [sqlite3_str] object X. 7947 ** 7948 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 7949 ** single-byte character C onto the end of [sqlite3_str] object X. 7950 ** ^This method can be used, for example, to add whitespace indentation. 7951 ** 7952 ** ^The [sqlite3_str_reset(X)] method resets the string under construction 7953 ** inside [sqlite3_str] object X back to zero bytes in length. 7954 ** 7955 ** These methods do not return a result code. ^If an error occurs, that fact 7956 ** is recorded in the [sqlite3_str] object and can be recovered by a 7957 ** subsequent call to [sqlite3_str_errcode(X)]. 7958 */ 7959 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 7960 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 7961 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 7962 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 7963 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 7964 SQLITE_API void sqlite3_str_reset(sqlite3_str*); 7965 7966 /* 7967 ** CAPI3REF: Status Of A Dynamic String 7968 ** METHOD: sqlite3_str 7969 ** 7970 ** These interfaces return the current status of an [sqlite3_str] object. 7971 ** 7972 ** ^If any prior errors have occurred while constructing the dynamic string 7973 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 7974 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 7975 ** [SQLITE_NOMEM] following any out-of-memory error, or 7976 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 7977 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 7978 ** 7979 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 7980 ** of the dynamic string under construction in [sqlite3_str] object X. 7981 ** ^The length returned by [sqlite3_str_length(X)] does not include the 7982 ** zero-termination byte. 7983 ** 7984 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current 7985 ** content of the dynamic string under construction in X. The value 7986 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 7987 ** and might be freed or altered by any subsequent method on the same 7988 ** [sqlite3_str] object. Applications must not used the pointer returned 7989 ** [sqlite3_str_value(X)] after any subsequent method call on the same 7990 ** object. ^Applications may change the content of the string returned 7991 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes 7992 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 7993 ** write any byte after any subsequent sqlite3_str method call. 7994 */ 7995 SQLITE_API int sqlite3_str_errcode(sqlite3_str*); 7996 SQLITE_API int sqlite3_str_length(sqlite3_str*); 7997 SQLITE_API char *sqlite3_str_value(sqlite3_str*); 7998 7999 /* 8000 ** CAPI3REF: SQLite Runtime Status 8001 ** 8002 ** ^These interfaces are used to retrieve runtime status information 8003 ** about the performance of SQLite, and optionally to reset various 8004 ** highwater marks. ^The first argument is an integer code for 8005 ** the specific parameter to measure. ^(Recognized integer codes 8006 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 8007 ** ^The current value of the parameter is returned into *pCurrent. 8008 ** ^The highest recorded value is returned in *pHighwater. ^If the 8009 ** resetFlag is true, then the highest record value is reset after 8010 ** *pHighwater is written. ^(Some parameters do not record the highest 8011 ** value. For those parameters 8012 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 8013 ** ^(Other parameters record only the highwater mark and not the current 8014 ** value. For these latter parameters nothing is written into *pCurrent.)^ 8015 ** 8016 ** ^The sqlite3_status() and sqlite3_status64() routines return 8017 ** SQLITE_OK on success and a non-zero [error code] on failure. 8018 ** 8019 ** If either the current value or the highwater mark is too large to 8020 ** be represented by a 32-bit integer, then the values returned by 8021 ** sqlite3_status() are undefined. 8022 ** 8023 ** See also: [sqlite3_db_status()] 8024 */ 8025 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 8026 SQLITE_API int sqlite3_status64( 8027 int op, 8028 sqlite3_int64 *pCurrent, 8029 sqlite3_int64 *pHighwater, 8030 int resetFlag 8031 ); 8032 8033 8034 /* 8035 ** CAPI3REF: Status Parameters 8036 ** KEYWORDS: {status parameters} 8037 ** 8038 ** These integer constants designate various run-time status parameters 8039 ** that can be returned by [sqlite3_status()]. 8040 ** 8041 ** <dl> 8042 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 8043 ** <dd>This parameter is the current amount of memory checked out 8044 ** using [sqlite3_malloc()], either directly or indirectly. The 8045 ** figure includes calls made to [sqlite3_malloc()] by the application 8046 ** and internal memory usage by the SQLite library. Auxiliary page-cache 8047 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 8048 ** this parameter. The amount returned is the sum of the allocation 8049 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 8050 ** 8051 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 8052 ** <dd>This parameter records the largest memory allocation request 8053 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 8054 ** internal equivalents). Only the value returned in the 8055 ** *pHighwater parameter to [sqlite3_status()] is of interest. 8056 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8057 ** 8058 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 8059 ** <dd>This parameter records the number of separate memory allocations 8060 ** currently checked out.</dd>)^ 8061 ** 8062 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 8063 ** <dd>This parameter returns the number of pages used out of the 8064 ** [pagecache memory allocator] that was configured using 8065 ** [SQLITE_CONFIG_PAGECACHE]. The 8066 ** value returned is in pages, not in bytes.</dd>)^ 8067 ** 8068 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 8069 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 8070 ** <dd>This parameter returns the number of bytes of page cache 8071 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 8072 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 8073 ** returned value includes allocations that overflowed because they 8074 ** where too large (they were larger than the "sz" parameter to 8075 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 8076 ** no space was left in the page cache.</dd>)^ 8077 ** 8078 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 8079 ** <dd>This parameter records the largest memory allocation request 8080 ** handed to the [pagecache memory allocator]. Only the value returned in the 8081 ** *pHighwater parameter to [sqlite3_status()] is of interest. 8082 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8083 ** 8084 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 8085 ** <dd>No longer used.</dd> 8086 ** 8087 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 8088 ** <dd>No longer used.</dd> 8089 ** 8090 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 8091 ** <dd>No longer used.</dd> 8092 ** 8093 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 8094 ** <dd>The *pHighwater parameter records the deepest parser stack. 8095 ** The *pCurrent value is undefined. The *pHighwater value is only 8096 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 8097 ** </dl> 8098 ** 8099 ** New status parameters may be added from time to time. 8100 */ 8101 #define SQLITE_STATUS_MEMORY_USED 0 8102 #define SQLITE_STATUS_PAGECACHE_USED 1 8103 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 8104 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 8105 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 8106 #define SQLITE_STATUS_MALLOC_SIZE 5 8107 #define SQLITE_STATUS_PARSER_STACK 6 8108 #define SQLITE_STATUS_PAGECACHE_SIZE 7 8109 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 8110 #define SQLITE_STATUS_MALLOC_COUNT 9 8111 8112 /* 8113 ** CAPI3REF: Database Connection Status 8114 ** METHOD: sqlite3 8115 ** 8116 ** ^This interface is used to retrieve runtime status information 8117 ** about a single [database connection]. ^The first argument is the 8118 ** database connection object to be interrogated. ^The second argument 8119 ** is an integer constant, taken from the set of 8120 ** [SQLITE_DBSTATUS options], that 8121 ** determines the parameter to interrogate. The set of 8122 ** [SQLITE_DBSTATUS options] is likely 8123 ** to grow in future releases of SQLite. 8124 ** 8125 ** ^The current value of the requested parameter is written into *pCur 8126 ** and the highest instantaneous value is written into *pHiwtr. ^If 8127 ** the resetFlg is true, then the highest instantaneous value is 8128 ** reset back down to the current value. 8129 ** 8130 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 8131 ** non-zero [error code] on failure. 8132 ** 8133 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 8134 */ 8135 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 8136 8137 /* 8138 ** CAPI3REF: Status Parameters for database connections 8139 ** KEYWORDS: {SQLITE_DBSTATUS options} 8140 ** 8141 ** These constants are the available integer "verbs" that can be passed as 8142 ** the second argument to the [sqlite3_db_status()] interface. 8143 ** 8144 ** New verbs may be added in future releases of SQLite. Existing verbs 8145 ** might be discontinued. Applications should check the return code from 8146 ** [sqlite3_db_status()] to make sure that the call worked. 8147 ** The [sqlite3_db_status()] interface will return a non-zero error code 8148 ** if a discontinued or unsupported verb is invoked. 8149 ** 8150 ** <dl> 8151 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 8152 ** <dd>This parameter returns the number of lookaside memory slots currently 8153 ** checked out.</dd>)^ 8154 ** 8155 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 8156 ** <dd>This parameter returns the number of malloc attempts that were 8157 ** satisfied using lookaside memory. Only the high-water value is meaningful; 8158 ** the current value is always zero.)^ 8159 ** 8160 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 8161 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 8162 ** <dd>This parameter returns the number malloc attempts that might have 8163 ** been satisfied using lookaside memory but failed due to the amount of 8164 ** memory requested being larger than the lookaside slot size. 8165 ** Only the high-water value is meaningful; 8166 ** the current value is always zero.)^ 8167 ** 8168 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 8169 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 8170 ** <dd>This parameter returns the number malloc attempts that might have 8171 ** been satisfied using lookaside memory but failed due to all lookaside 8172 ** memory already being in use. 8173 ** Only the high-water value is meaningful; 8174 ** the current value is always zero.)^ 8175 ** 8176 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 8177 ** <dd>This parameter returns the approximate number of bytes of heap 8178 ** memory used by all pager caches associated with the database connection.)^ 8179 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 8180 ** 8181 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 8182 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 8183 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 8184 ** pager cache is shared between two or more connections the bytes of heap 8185 ** memory used by that pager cache is divided evenly between the attached 8186 ** connections.)^ In other words, if none of the pager caches associated 8187 ** with the database connection are shared, this request returns the same 8188 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 8189 ** shared, the value returned by this call will be smaller than that returned 8190 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 8191 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 8192 ** 8193 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 8194 ** <dd>This parameter returns the approximate number of bytes of heap 8195 ** memory used to store the schema for all databases associated 8196 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 8197 ** ^The full amount of memory used by the schemas is reported, even if the 8198 ** schema memory is shared with other database connections due to 8199 ** [shared cache mode] being enabled. 8200 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 8201 ** 8202 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 8203 ** <dd>This parameter returns the approximate number of bytes of heap 8204 ** and lookaside memory used by all prepared statements associated with 8205 ** the database connection.)^ 8206 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 8207 ** </dd> 8208 ** 8209 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 8210 ** <dd>This parameter returns the number of pager cache hits that have 8211 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 8212 ** is always 0. 8213 ** </dd> 8214 ** 8215 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 8216 ** <dd>This parameter returns the number of pager cache misses that have 8217 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 8218 ** is always 0. 8219 ** </dd> 8220 ** 8221 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 8222 ** <dd>This parameter returns the number of dirty cache entries that have 8223 ** been written to disk. Specifically, the number of pages written to the 8224 ** wal file in wal mode databases, or the number of pages written to the 8225 ** database file in rollback mode databases. Any pages written as part of 8226 ** transaction rollback or database recovery operations are not included. 8227 ** If an IO or other error occurs while writing a page to disk, the effect 8228 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 8229 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 8230 ** </dd> 8231 ** 8232 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 8233 ** <dd>This parameter returns the number of dirty cache entries that have 8234 ** been written to disk in the middle of a transaction due to the page 8235 ** cache overflowing. Transactions are more efficient if they are written 8236 ** to disk all at once. When pages spill mid-transaction, that introduces 8237 ** additional overhead. This parameter can be used help identify 8238 ** inefficiencies that can be resolved by increasing the cache size. 8239 ** </dd> 8240 ** 8241 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 8242 ** <dd>This parameter returns zero for the current value if and only if 8243 ** all foreign key constraints (deferred or immediate) have been 8244 ** resolved.)^ ^The highwater mark is always 0. 8245 ** </dd> 8246 ** </dl> 8247 */ 8248 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 8249 #define SQLITE_DBSTATUS_CACHE_USED 1 8250 #define SQLITE_DBSTATUS_SCHEMA_USED 2 8251 #define SQLITE_DBSTATUS_STMT_USED 3 8252 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 8253 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 8254 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 8255 #define SQLITE_DBSTATUS_CACHE_HIT 7 8256 #define SQLITE_DBSTATUS_CACHE_MISS 8 8257 #define SQLITE_DBSTATUS_CACHE_WRITE 9 8258 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 8259 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 8260 #define SQLITE_DBSTATUS_CACHE_SPILL 12 8261 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 8262 8263 8264 /* 8265 ** CAPI3REF: Prepared Statement Status 8266 ** METHOD: sqlite3_stmt 8267 ** 8268 ** ^(Each prepared statement maintains various 8269 ** [SQLITE_STMTSTATUS counters] that measure the number 8270 ** of times it has performed specific operations.)^ These counters can 8271 ** be used to monitor the performance characteristics of the prepared 8272 ** statements. For example, if the number of table steps greatly exceeds 8273 ** the number of table searches or result rows, that would tend to indicate 8274 ** that the prepared statement is using a full table scan rather than 8275 ** an index. 8276 ** 8277 ** ^(This interface is used to retrieve and reset counter values from 8278 ** a [prepared statement]. The first argument is the prepared statement 8279 ** object to be interrogated. The second argument 8280 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 8281 ** to be interrogated.)^ 8282 ** ^The current value of the requested counter is returned. 8283 ** ^If the resetFlg is true, then the counter is reset to zero after this 8284 ** interface call returns. 8285 ** 8286 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 8287 */ 8288 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 8289 8290 /* 8291 ** CAPI3REF: Status Parameters for prepared statements 8292 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 8293 ** 8294 ** These preprocessor macros define integer codes that name counter 8295 ** values associated with the [sqlite3_stmt_status()] interface. 8296 ** The meanings of the various counters are as follows: 8297 ** 8298 ** <dl> 8299 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 8300 ** <dd>^This is the number of times that SQLite has stepped forward in 8301 ** a table as part of a full table scan. Large numbers for this counter 8302 ** may indicate opportunities for performance improvement through 8303 ** careful use of indices.</dd> 8304 ** 8305 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 8306 ** <dd>^This is the number of sort operations that have occurred. 8307 ** A non-zero value in this counter may indicate an opportunity to 8308 ** improvement performance through careful use of indices.</dd> 8309 ** 8310 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 8311 ** <dd>^This is the number of rows inserted into transient indices that 8312 ** were created automatically in order to help joins run faster. 8313 ** A non-zero value in this counter may indicate an opportunity to 8314 ** improvement performance by adding permanent indices that do not 8315 ** need to be reinitialized each time the statement is run.</dd> 8316 ** 8317 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 8318 ** <dd>^This is the number of virtual machine operations executed 8319 ** by the prepared statement if that number is less than or equal 8320 ** to 2147483647. The number of virtual machine operations can be 8321 ** used as a proxy for the total work done by the prepared statement. 8322 ** If the number of virtual machine operations exceeds 2147483647 8323 ** then the value returned by this statement status code is undefined. 8324 ** 8325 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 8326 ** <dd>^This is the number of times that the prepare statement has been 8327 ** automatically regenerated due to schema changes or changes to 8328 ** [bound parameters] that might affect the query plan. 8329 ** 8330 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 8331 ** <dd>^This is the number of times that the prepared statement has 8332 ** been run. A single "run" for the purposes of this counter is one 8333 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 8334 ** The counter is incremented on the first [sqlite3_step()] call of each 8335 ** cycle. 8336 ** 8337 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 8338 ** <dd>^This is the approximate number of bytes of heap memory 8339 ** used to store the prepared statement. ^This value is not actually 8340 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 8341 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 8342 ** </dd> 8343 ** </dl> 8344 */ 8345 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 8346 #define SQLITE_STMTSTATUS_SORT 2 8347 #define SQLITE_STMTSTATUS_AUTOINDEX 3 8348 #define SQLITE_STMTSTATUS_VM_STEP 4 8349 #define SQLITE_STMTSTATUS_REPREPARE 5 8350 #define SQLITE_STMTSTATUS_RUN 6 8351 #define SQLITE_STMTSTATUS_MEMUSED 99 8352 8353 /* 8354 ** CAPI3REF: Custom Page Cache Object 8355 ** 8356 ** The sqlite3_pcache type is opaque. It is implemented by 8357 ** the pluggable module. The SQLite core has no knowledge of 8358 ** its size or internal structure and never deals with the 8359 ** sqlite3_pcache object except by holding and passing pointers 8360 ** to the object. 8361 ** 8362 ** See [sqlite3_pcache_methods2] for additional information. 8363 */ 8364 typedef struct sqlite3_pcache sqlite3_pcache; 8365 8366 /* 8367 ** CAPI3REF: Custom Page Cache Object 8368 ** 8369 ** The sqlite3_pcache_page object represents a single page in the 8370 ** page cache. The page cache will allocate instances of this 8371 ** object. Various methods of the page cache use pointers to instances 8372 ** of this object as parameters or as their return value. 8373 ** 8374 ** See [sqlite3_pcache_methods2] for additional information. 8375 */ 8376 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 8377 struct sqlite3_pcache_page { 8378 void *pBuf; /* The content of the page */ 8379 void *pExtra; /* Extra information associated with the page */ 8380 }; 8381 8382 /* 8383 ** CAPI3REF: Application Defined Page Cache. 8384 ** KEYWORDS: {page cache} 8385 ** 8386 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 8387 ** register an alternative page cache implementation by passing in an 8388 ** instance of the sqlite3_pcache_methods2 structure.)^ 8389 ** In many applications, most of the heap memory allocated by 8390 ** SQLite is used for the page cache. 8391 ** By implementing a 8392 ** custom page cache using this API, an application can better control 8393 ** the amount of memory consumed by SQLite, the way in which 8394 ** that memory is allocated and released, and the policies used to 8395 ** determine exactly which parts of a database file are cached and for 8396 ** how long. 8397 ** 8398 ** The alternative page cache mechanism is an 8399 ** extreme measure that is only needed by the most demanding applications. 8400 ** The built-in page cache is recommended for most uses. 8401 ** 8402 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 8403 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 8404 ** the application may discard the parameter after the call to 8405 ** [sqlite3_config()] returns.)^ 8406 ** 8407 ** [[the xInit() page cache method]] 8408 ** ^(The xInit() method is called once for each effective 8409 ** call to [sqlite3_initialize()])^ 8410 ** (usually only once during the lifetime of the process). ^(The xInit() 8411 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8412 ** The intent of the xInit() method is to set up global data structures 8413 ** required by the custom page cache implementation. 8414 ** ^(If the xInit() method is NULL, then the 8415 ** built-in default page cache is used instead of the application defined 8416 ** page cache.)^ 8417 ** 8418 ** [[the xShutdown() page cache method]] 8419 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 8420 ** It can be used to clean up 8421 ** any outstanding resources before process shutdown, if required. 8422 ** ^The xShutdown() method may be NULL. 8423 ** 8424 ** ^SQLite automatically serializes calls to the xInit method, 8425 ** so the xInit method need not be threadsafe. ^The 8426 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 8427 ** not need to be threadsafe either. All other methods must be threadsafe 8428 ** in multithreaded applications. 8429 ** 8430 ** ^SQLite will never invoke xInit() more than once without an intervening 8431 ** call to xShutdown(). 8432 ** 8433 ** [[the xCreate() page cache methods]] 8434 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 8435 ** SQLite will typically create one cache instance for each open database file, 8436 ** though this is not guaranteed. ^The 8437 ** first parameter, szPage, is the size in bytes of the pages that must 8438 ** be allocated by the cache. ^szPage will always a power of two. ^The 8439 ** second parameter szExtra is a number of bytes of extra storage 8440 ** associated with each page cache entry. ^The szExtra parameter will 8441 ** a number less than 250. SQLite will use the 8442 ** extra szExtra bytes on each page to store metadata about the underlying 8443 ** database page on disk. The value passed into szExtra depends 8444 ** on the SQLite version, the target platform, and how SQLite was compiled. 8445 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 8446 ** created will be used to cache database pages of a file stored on disk, or 8447 ** false if it is used for an in-memory database. The cache implementation 8448 ** does not have to do anything special based with the value of bPurgeable; 8449 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 8450 ** never invoke xUnpin() except to deliberately delete a page. 8451 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 8452 ** false will always have the "discard" flag set to true. 8453 ** ^Hence, a cache created with bPurgeable false will 8454 ** never contain any unpinned pages. 8455 ** 8456 ** [[the xCachesize() page cache method]] 8457 ** ^(The xCachesize() method may be called at any time by SQLite to set the 8458 ** suggested maximum cache-size (number of pages stored by) the cache 8459 ** instance passed as the first argument. This is the value configured using 8460 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 8461 ** parameter, the implementation is not required to do anything with this 8462 ** value; it is advisory only. 8463 ** 8464 ** [[the xPagecount() page cache methods]] 8465 ** The xPagecount() method must return the number of pages currently 8466 ** stored in the cache, both pinned and unpinned. 8467 ** 8468 ** [[the xFetch() page cache methods]] 8469 ** The xFetch() method locates a page in the cache and returns a pointer to 8470 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 8471 ** The pBuf element of the returned sqlite3_pcache_page object will be a 8472 ** pointer to a buffer of szPage bytes used to store the content of a 8473 ** single database page. The pExtra element of sqlite3_pcache_page will be 8474 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 8475 ** for each entry in the page cache. 8476 ** 8477 ** The page to be fetched is determined by the key. ^The minimum key value 8478 ** is 1. After it has been retrieved using xFetch, the page is considered 8479 ** to be "pinned". 8480 ** 8481 ** If the requested page is already in the page cache, then the page cache 8482 ** implementation must return a pointer to the page buffer with its content 8483 ** intact. If the requested page is not already in the cache, then the 8484 ** cache implementation should use the value of the createFlag 8485 ** parameter to help it determined what action to take: 8486 ** 8487 ** <table border=1 width=85% align=center> 8488 ** <tr><th> createFlag <th> Behavior when page is not already in cache 8489 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 8490 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 8491 ** Otherwise return NULL. 8492 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 8493 ** NULL if allocating a new page is effectively impossible. 8494 ** </table> 8495 ** 8496 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 8497 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 8498 ** failed.)^ In between the xFetch() calls, SQLite may 8499 ** attempt to unpin one or more cache pages by spilling the content of 8500 ** pinned pages to disk and synching the operating system disk cache. 8501 ** 8502 ** [[the xUnpin() page cache method]] 8503 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 8504 ** as its second argument. If the third parameter, discard, is non-zero, 8505 ** then the page must be evicted from the cache. 8506 ** ^If the discard parameter is 8507 ** zero, then the page may be discarded or retained at the discretion of 8508 ** page cache implementation. ^The page cache implementation 8509 ** may choose to evict unpinned pages at any time. 8510 ** 8511 ** The cache must not perform any reference counting. A single 8512 ** call to xUnpin() unpins the page regardless of the number of prior calls 8513 ** to xFetch(). 8514 ** 8515 ** [[the xRekey() page cache methods]] 8516 ** The xRekey() method is used to change the key value associated with the 8517 ** page passed as the second argument. If the cache 8518 ** previously contains an entry associated with newKey, it must be 8519 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 8520 ** to be pinned. 8521 ** 8522 ** When SQLite calls the xTruncate() method, the cache must discard all 8523 ** existing cache entries with page numbers (keys) greater than or equal 8524 ** to the value of the iLimit parameter passed to xTruncate(). If any 8525 ** of these pages are pinned, they are implicitly unpinned, meaning that 8526 ** they can be safely discarded. 8527 ** 8528 ** [[the xDestroy() page cache method]] 8529 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 8530 ** All resources associated with the specified cache should be freed. ^After 8531 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 8532 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 8533 ** functions. 8534 ** 8535 ** [[the xShrink() page cache method]] 8536 ** ^SQLite invokes the xShrink() method when it wants the page cache to 8537 ** free up as much of heap memory as possible. The page cache implementation 8538 ** is not obligated to free any memory, but well-behaved implementations should 8539 ** do their best. 8540 */ 8541 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 8542 struct sqlite3_pcache_methods2 { 8543 int iVersion; 8544 void *pArg; 8545 int (*xInit)(void*); 8546 void (*xShutdown)(void*); 8547 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 8548 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8549 int (*xPagecount)(sqlite3_pcache*); 8550 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8551 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 8552 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 8553 unsigned oldKey, unsigned newKey); 8554 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8555 void (*xDestroy)(sqlite3_pcache*); 8556 void (*xShrink)(sqlite3_pcache*); 8557 }; 8558 8559 /* 8560 ** This is the obsolete pcache_methods object that has now been replaced 8561 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8562 ** retained in the header file for backwards compatibility only. 8563 */ 8564 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8565 struct sqlite3_pcache_methods { 8566 void *pArg; 8567 int (*xInit)(void*); 8568 void (*xShutdown)(void*); 8569 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8570 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8571 int (*xPagecount)(sqlite3_pcache*); 8572 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8573 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8574 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8575 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8576 void (*xDestroy)(sqlite3_pcache*); 8577 }; 8578 8579 8580 /* 8581 ** CAPI3REF: Online Backup Object 8582 ** 8583 ** The sqlite3_backup object records state information about an ongoing 8584 ** online backup operation. ^The sqlite3_backup object is created by 8585 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 8586 ** [sqlite3_backup_finish()]. 8587 ** 8588 ** See Also: [Using the SQLite Online Backup API] 8589 */ 8590 typedef struct sqlite3_backup sqlite3_backup; 8591 8592 /* 8593 ** CAPI3REF: Online Backup API. 8594 ** 8595 ** The backup API copies the content of one database into another. 8596 ** It is useful either for creating backups of databases or 8597 ** for copying in-memory databases to or from persistent files. 8598 ** 8599 ** See Also: [Using the SQLite Online Backup API] 8600 ** 8601 ** ^SQLite holds a write transaction open on the destination database file 8602 ** for the duration of the backup operation. 8603 ** ^The source database is read-locked only while it is being read; 8604 ** it is not locked continuously for the entire backup operation. 8605 ** ^Thus, the backup may be performed on a live source database without 8606 ** preventing other database connections from 8607 ** reading or writing to the source database while the backup is underway. 8608 ** 8609 ** ^(To perform a backup operation: 8610 ** <ol> 8611 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8612 ** backup, 8613 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8614 ** the data between the two databases, and finally 8615 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8616 ** associated with the backup operation. 8617 ** </ol>)^ 8618 ** There should be exactly one call to sqlite3_backup_finish() for each 8619 ** successful call to sqlite3_backup_init(). 8620 ** 8621 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8622 ** 8623 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8624 ** [database connection] associated with the destination database 8625 ** and the database name, respectively. 8626 ** ^The database name is "main" for the main database, "temp" for the 8627 ** temporary database, or the name specified after the AS keyword in 8628 ** an [ATTACH] statement for an attached database. 8629 ** ^The S and M arguments passed to 8630 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8631 ** and database name of the source database, respectively. 8632 ** ^The source and destination [database connections] (parameters S and D) 8633 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8634 ** an error. 8635 ** 8636 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8637 ** there is already a read or read-write transaction open on the 8638 ** destination database. 8639 ** 8640 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8641 ** returned and an error code and error message are stored in the 8642 ** destination [database connection] D. 8643 ** ^The error code and message for the failed call to sqlite3_backup_init() 8644 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8645 ** [sqlite3_errmsg16()] functions. 8646 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 8647 ** [sqlite3_backup] object. 8648 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8649 ** sqlite3_backup_finish() functions to perform the specified backup 8650 ** operation. 8651 ** 8652 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8653 ** 8654 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8655 ** the source and destination databases specified by [sqlite3_backup] object B. 8656 ** ^If N is negative, all remaining source pages are copied. 8657 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8658 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 8659 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8660 ** from source to destination, then it returns [SQLITE_DONE]. 8661 ** ^If an error occurs while running sqlite3_backup_step(B,N), 8662 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 8663 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8664 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8665 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8666 ** 8667 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8668 ** <ol> 8669 ** <li> the destination database was opened read-only, or 8670 ** <li> the destination database is using write-ahead-log journaling 8671 ** and the destination and source page sizes differ, or 8672 ** <li> the destination database is an in-memory database and the 8673 ** destination and source page sizes differ. 8674 ** </ol>)^ 8675 ** 8676 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8677 ** the [sqlite3_busy_handler | busy-handler function] 8678 ** is invoked (if one is specified). ^If the 8679 ** busy-handler returns non-zero before the lock is available, then 8680 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8681 ** sqlite3_backup_step() can be retried later. ^If the source 8682 ** [database connection] 8683 ** is being used to write to the source database when sqlite3_backup_step() 8684 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8685 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 8686 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8687 ** [SQLITE_READONLY] is returned, then 8688 ** there is no point in retrying the call to sqlite3_backup_step(). These 8689 ** errors are considered fatal.)^ The application must accept 8690 ** that the backup operation has failed and pass the backup operation handle 8691 ** to the sqlite3_backup_finish() to release associated resources. 8692 ** 8693 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8694 ** on the destination file. ^The exclusive lock is not released until either 8695 ** sqlite3_backup_finish() is called or the backup operation is complete 8696 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8697 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 8698 ** lasts for the duration of the sqlite3_backup_step() call. 8699 ** ^Because the source database is not locked between calls to 8700 ** sqlite3_backup_step(), the source database may be modified mid-way 8701 ** through the backup process. ^If the source database is modified by an 8702 ** external process or via a database connection other than the one being 8703 ** used by the backup operation, then the backup will be automatically 8704 ** restarted by the next call to sqlite3_backup_step(). ^If the source 8705 ** database is modified by the using the same database connection as is used 8706 ** by the backup operation, then the backup database is automatically 8707 ** updated at the same time. 8708 ** 8709 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8710 ** 8711 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8712 ** application wishes to abandon the backup operation, the application 8713 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8714 ** ^The sqlite3_backup_finish() interfaces releases all 8715 ** resources associated with the [sqlite3_backup] object. 8716 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8717 ** active write-transaction on the destination database is rolled back. 8718 ** The [sqlite3_backup] object is invalid 8719 ** and may not be used following a call to sqlite3_backup_finish(). 8720 ** 8721 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8722 ** sqlite3_backup_step() errors occurred, regardless or whether or not 8723 ** sqlite3_backup_step() completed. 8724 ** ^If an out-of-memory condition or IO error occurred during any prior 8725 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8726 ** sqlite3_backup_finish() returns the corresponding [error code]. 8727 ** 8728 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8729 ** is not a permanent error and does not affect the return value of 8730 ** sqlite3_backup_finish(). 8731 ** 8732 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8733 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8734 ** 8735 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 8736 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8737 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8738 ** in the source database at the conclusion of the most recent 8739 ** sqlite3_backup_step(). 8740 ** ^(The values returned by these functions are only updated by 8741 ** sqlite3_backup_step(). If the source database is modified in a way that 8742 ** changes the size of the source database or the number of pages remaining, 8743 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 8744 ** and sqlite3_backup_remaining() until after the next 8745 ** sqlite3_backup_step().)^ 8746 ** 8747 ** <b>Concurrent Usage of Database Handles</b> 8748 ** 8749 ** ^The source [database connection] may be used by the application for other 8750 ** purposes while a backup operation is underway or being initialized. 8751 ** ^If SQLite is compiled and configured to support threadsafe database 8752 ** connections, then the source database connection may be used concurrently 8753 ** from within other threads. 8754 ** 8755 ** However, the application must guarantee that the destination 8756 ** [database connection] is not passed to any other API (by any thread) after 8757 ** sqlite3_backup_init() is called and before the corresponding call to 8758 ** sqlite3_backup_finish(). SQLite does not currently check to see 8759 ** if the application incorrectly accesses the destination [database connection] 8760 ** and so no error code is reported, but the operations may malfunction 8761 ** nevertheless. Use of the destination database connection while a 8762 ** backup is in progress might also also cause a mutex deadlock. 8763 ** 8764 ** If running in [shared cache mode], the application must 8765 ** guarantee that the shared cache used by the destination database 8766 ** is not accessed while the backup is running. In practice this means 8767 ** that the application must guarantee that the disk file being 8768 ** backed up to is not accessed by any connection within the process, 8769 ** not just the specific connection that was passed to sqlite3_backup_init(). 8770 ** 8771 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8772 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8773 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8774 ** APIs are not strictly speaking threadsafe. If they are invoked at the 8775 ** same time as another thread is invoking sqlite3_backup_step() it is 8776 ** possible that they return invalid values. 8777 */ 8778 SQLITE_API sqlite3_backup *sqlite3_backup_init( 8779 sqlite3 *pDest, /* Destination database handle */ 8780 const char *zDestName, /* Destination database name */ 8781 sqlite3 *pSource, /* Source database handle */ 8782 const char *zSourceName /* Source database name */ 8783 ); 8784 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8785 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 8786 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 8787 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 8788 8789 /* 8790 ** CAPI3REF: Unlock Notification 8791 ** METHOD: sqlite3 8792 ** 8793 ** ^When running in shared-cache mode, a database operation may fail with 8794 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8795 ** individual tables within the shared-cache cannot be obtained. See 8796 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8797 ** ^This API may be used to register a callback that SQLite will invoke 8798 ** when the connection currently holding the required lock relinquishes it. 8799 ** ^This API is only available if the library was compiled with the 8800 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8801 ** 8802 ** See Also: [Using the SQLite Unlock Notification Feature]. 8803 ** 8804 ** ^Shared-cache locks are released when a database connection concludes 8805 ** its current transaction, either by committing it or rolling it back. 8806 ** 8807 ** ^When a connection (known as the blocked connection) fails to obtain a 8808 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 8809 ** identity of the database connection (the blocking connection) that 8810 ** has locked the required resource is stored internally. ^After an 8811 ** application receives an SQLITE_LOCKED error, it may call the 8812 ** sqlite3_unlock_notify() method with the blocked connection handle as 8813 ** the first argument to register for a callback that will be invoked 8814 ** when the blocking connections current transaction is concluded. ^The 8815 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 8816 ** call that concludes the blocking connection's transaction. 8817 ** 8818 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 8819 ** there is a chance that the blocking connection will have already 8820 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 8821 ** If this happens, then the specified callback is invoked immediately, 8822 ** from within the call to sqlite3_unlock_notify().)^ 8823 ** 8824 ** ^If the blocked connection is attempting to obtain a write-lock on a 8825 ** shared-cache table, and more than one other connection currently holds 8826 ** a read-lock on the same table, then SQLite arbitrarily selects one of 8827 ** the other connections to use as the blocking connection. 8828 ** 8829 ** ^(There may be at most one unlock-notify callback registered by a 8830 ** blocked connection. If sqlite3_unlock_notify() is called when the 8831 ** blocked connection already has a registered unlock-notify callback, 8832 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 8833 ** called with a NULL pointer as its second argument, then any existing 8834 ** unlock-notify callback is canceled. ^The blocked connections 8835 ** unlock-notify callback may also be canceled by closing the blocked 8836 ** connection using [sqlite3_close()]. 8837 ** 8838 ** The unlock-notify callback is not reentrant. If an application invokes 8839 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 8840 ** crash or deadlock may be the result. 8841 ** 8842 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 8843 ** returns SQLITE_OK. 8844 ** 8845 ** <b>Callback Invocation Details</b> 8846 ** 8847 ** When an unlock-notify callback is registered, the application provides a 8848 ** single void* pointer that is passed to the callback when it is invoked. 8849 ** However, the signature of the callback function allows SQLite to pass 8850 ** it an array of void* context pointers. The first argument passed to 8851 ** an unlock-notify callback is a pointer to an array of void* pointers, 8852 ** and the second is the number of entries in the array. 8853 ** 8854 ** When a blocking connection's transaction is concluded, there may be 8855 ** more than one blocked connection that has registered for an unlock-notify 8856 ** callback. ^If two or more such blocked connections have specified the 8857 ** same callback function, then instead of invoking the callback function 8858 ** multiple times, it is invoked once with the set of void* context pointers 8859 ** specified by the blocked connections bundled together into an array. 8860 ** This gives the application an opportunity to prioritize any actions 8861 ** related to the set of unblocked database connections. 8862 ** 8863 ** <b>Deadlock Detection</b> 8864 ** 8865 ** Assuming that after registering for an unlock-notify callback a 8866 ** database waits for the callback to be issued before taking any further 8867 ** action (a reasonable assumption), then using this API may cause the 8868 ** application to deadlock. For example, if connection X is waiting for 8869 ** connection Y's transaction to be concluded, and similarly connection 8870 ** Y is waiting on connection X's transaction, then neither connection 8871 ** will proceed and the system may remain deadlocked indefinitely. 8872 ** 8873 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 8874 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 8875 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 8876 ** unlock-notify callback is registered. The system is said to be in 8877 ** a deadlocked state if connection A has registered for an unlock-notify 8878 ** callback on the conclusion of connection B's transaction, and connection 8879 ** B has itself registered for an unlock-notify callback when connection 8880 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 8881 ** the system is also considered to be deadlocked if connection B has 8882 ** registered for an unlock-notify callback on the conclusion of connection 8883 ** C's transaction, where connection C is waiting on connection A. ^Any 8884 ** number of levels of indirection are allowed. 8885 ** 8886 ** <b>The "DROP TABLE" Exception</b> 8887 ** 8888 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 8889 ** always appropriate to call sqlite3_unlock_notify(). There is however, 8890 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 8891 ** SQLite checks if there are any currently executing SELECT statements 8892 ** that belong to the same connection. If there are, SQLITE_LOCKED is 8893 ** returned. In this case there is no "blocking connection", so invoking 8894 ** sqlite3_unlock_notify() results in the unlock-notify callback being 8895 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 8896 ** or "DROP INDEX" query, an infinite loop might be the result. 8897 ** 8898 ** One way around this problem is to check the extended error code returned 8899 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 8900 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 8901 ** the special "DROP TABLE/INDEX" case, the extended error code is just 8902 ** SQLITE_LOCKED.)^ 8903 */ 8904 SQLITE_API int sqlite3_unlock_notify( 8905 sqlite3 *pBlocked, /* Waiting connection */ 8906 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 8907 void *pNotifyArg /* Argument to pass to xNotify */ 8908 ); 8909 8910 8911 /* 8912 ** CAPI3REF: String Comparison 8913 ** 8914 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 8915 ** and extensions to compare the contents of two buffers containing UTF-8 8916 ** strings in a case-independent fashion, using the same definition of "case 8917 ** independence" that SQLite uses internally when comparing identifiers. 8918 */ 8919 SQLITE_API int sqlite3_stricmp(const char *, const char *); 8920 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 8921 8922 /* 8923 ** CAPI3REF: String Globbing 8924 * 8925 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 8926 ** string X matches the [GLOB] pattern P. 8927 ** ^The definition of [GLOB] pattern matching used in 8928 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 8929 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 8930 ** is case sensitive. 8931 ** 8932 ** Note that this routine returns zero on a match and non-zero if the strings 8933 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8934 ** 8935 ** See also: [sqlite3_strlike()]. 8936 */ 8937 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 8938 8939 /* 8940 ** CAPI3REF: String LIKE Matching 8941 * 8942 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 8943 ** string X matches the [LIKE] pattern P with escape character E. 8944 ** ^The definition of [LIKE] pattern matching used in 8945 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 8946 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 8947 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 8948 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 8949 ** insensitive - equivalent upper and lower case ASCII characters match 8950 ** one another. 8951 ** 8952 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 8953 ** only ASCII characters are case folded. 8954 ** 8955 ** Note that this routine returns zero on a match and non-zero if the strings 8956 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8957 ** 8958 ** See also: [sqlite3_strglob()]. 8959 */ 8960 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 8961 8962 /* 8963 ** CAPI3REF: Error Logging Interface 8964 ** 8965 ** ^The [sqlite3_log()] interface writes a message into the [error log] 8966 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 8967 ** ^If logging is enabled, the zFormat string and subsequent arguments are 8968 ** used with [sqlite3_snprintf()] to generate the final output string. 8969 ** 8970 ** The sqlite3_log() interface is intended for use by extensions such as 8971 ** virtual tables, collating functions, and SQL functions. While there is 8972 ** nothing to prevent an application from calling sqlite3_log(), doing so 8973 ** is considered bad form. 8974 ** 8975 ** The zFormat string must not be NULL. 8976 ** 8977 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 8978 ** will not use dynamically allocated memory. The log message is stored in 8979 ** a fixed-length buffer on the stack. If the log message is longer than 8980 ** a few hundred characters, it will be truncated to the length of the 8981 ** buffer. 8982 */ 8983 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 8984 8985 /* 8986 ** CAPI3REF: Write-Ahead Log Commit Hook 8987 ** METHOD: sqlite3 8988 ** 8989 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 8990 ** is invoked each time data is committed to a database in wal mode. 8991 ** 8992 ** ^(The callback is invoked by SQLite after the commit has taken place and 8993 ** the associated write-lock on the database released)^, so the implementation 8994 ** may read, write or [checkpoint] the database as required. 8995 ** 8996 ** ^The first parameter passed to the callback function when it is invoked 8997 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 8998 ** registering the callback. ^The second is a copy of the database handle. 8999 ** ^The third parameter is the name of the database that was written to - 9000 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 9001 ** is the number of pages currently in the write-ahead log file, 9002 ** including those that were just committed. 9003 ** 9004 ** The callback function should normally return [SQLITE_OK]. ^If an error 9005 ** code is returned, that error will propagate back up through the 9006 ** SQLite code base to cause the statement that provoked the callback 9007 ** to report an error, though the commit will have still occurred. If the 9008 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 9009 ** that does not correspond to any valid SQLite error code, the results 9010 ** are undefined. 9011 ** 9012 ** A single database handle may have at most a single write-ahead log callback 9013 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 9014 ** previously registered write-ahead log callback. ^Note that the 9015 ** [sqlite3_wal_autocheckpoint()] interface and the 9016 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 9017 ** overwrite any prior [sqlite3_wal_hook()] settings. 9018 */ 9019 SQLITE_API void *sqlite3_wal_hook( 9020 sqlite3*, 9021 int(*)(void *,sqlite3*,const char*,int), 9022 void* 9023 ); 9024 9025 /* 9026 ** CAPI3REF: Configure an auto-checkpoint 9027 ** METHOD: sqlite3 9028 ** 9029 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 9030 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 9031 ** to automatically [checkpoint] 9032 ** after committing a transaction if there are N or 9033 ** more frames in the [write-ahead log] file. ^Passing zero or 9034 ** a negative value as the nFrame parameter disables automatic 9035 ** checkpoints entirely. 9036 ** 9037 ** ^The callback registered by this function replaces any existing callback 9038 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 9039 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 9040 ** configured by this function. 9041 ** 9042 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 9043 ** from SQL. 9044 ** 9045 ** ^Checkpoints initiated by this mechanism are 9046 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 9047 ** 9048 ** ^Every new [database connection] defaults to having the auto-checkpoint 9049 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 9050 ** pages. The use of this interface 9051 ** is only necessary if the default setting is found to be suboptimal 9052 ** for a particular application. 9053 */ 9054 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 9055 9056 /* 9057 ** CAPI3REF: Checkpoint a database 9058 ** METHOD: sqlite3 9059 ** 9060 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 9061 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 9062 ** 9063 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 9064 ** [write-ahead log] for database X on [database connection] D to be 9065 ** transferred into the database file and for the write-ahead log to 9066 ** be reset. See the [checkpointing] documentation for addition 9067 ** information. 9068 ** 9069 ** This interface used to be the only way to cause a checkpoint to 9070 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 9071 ** interface was added. This interface is retained for backwards 9072 ** compatibility and as a convenience for applications that need to manually 9073 ** start a callback but which do not need the full power (and corresponding 9074 ** complication) of [sqlite3_wal_checkpoint_v2()]. 9075 */ 9076 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 9077 9078 /* 9079 ** CAPI3REF: Checkpoint a database 9080 ** METHOD: sqlite3 9081 ** 9082 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 9083 ** operation on database X of [database connection] D in mode M. Status 9084 ** information is written back into integers pointed to by L and C.)^ 9085 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 9086 ** 9087 ** <dl> 9088 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 9089 ** ^Checkpoint as many frames as possible without waiting for any database 9090 ** readers or writers to finish, then sync the database file if all frames 9091 ** in the log were checkpointed. ^The [busy-handler callback] 9092 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 9093 ** ^On the other hand, passive mode might leave the checkpoint unfinished 9094 ** if there are concurrent readers or writers. 9095 ** 9096 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 9097 ** ^This mode blocks (it invokes the 9098 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 9099 ** database writer and all readers are reading from the most recent database 9100 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 9101 ** database file. ^This mode blocks new database writers while it is pending, 9102 ** but new database readers are allowed to continue unimpeded. 9103 ** 9104 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 9105 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 9106 ** that after checkpointing the log file it blocks (calls the 9107 ** [busy-handler callback]) 9108 ** until all readers are reading from the database file only. ^This ensures 9109 ** that the next writer will restart the log file from the beginning. 9110 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 9111 ** database writer attempts while it is pending, but does not impede readers. 9112 ** 9113 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 9114 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 9115 ** addition that it also truncates the log file to zero bytes just prior 9116 ** to a successful return. 9117 ** </dl> 9118 ** 9119 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 9120 ** the log file or to -1 if the checkpoint could not run because 9121 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 9122 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 9123 ** log file (including any that were already checkpointed before the function 9124 ** was called) or to -1 if the checkpoint could not run due to an error or 9125 ** because the database is not in WAL mode. ^Note that upon successful 9126 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 9127 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 9128 ** 9129 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 9130 ** any other process is running a checkpoint operation at the same time, the 9131 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 9132 ** busy-handler configured, it will not be invoked in this case. 9133 ** 9134 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 9135 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 9136 ** obtained immediately, and a busy-handler is configured, it is invoked and 9137 ** the writer lock retried until either the busy-handler returns 0 or the lock 9138 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 9139 ** database readers as described above. ^If the busy-handler returns 0 before 9140 ** the writer lock is obtained or while waiting for database readers, the 9141 ** checkpoint operation proceeds from that point in the same way as 9142 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 9143 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 9144 ** 9145 ** ^If parameter zDb is NULL or points to a zero length string, then the 9146 ** specified operation is attempted on all WAL databases [attached] to 9147 ** [database connection] db. In this case the 9148 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 9149 ** an SQLITE_BUSY error is encountered when processing one or more of the 9150 ** attached WAL databases, the operation is still attempted on any remaining 9151 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 9152 ** error occurs while processing an attached database, processing is abandoned 9153 ** and the error code is returned to the caller immediately. ^If no error 9154 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 9155 ** databases, SQLITE_OK is returned. 9156 ** 9157 ** ^If database zDb is the name of an attached database that is not in WAL 9158 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 9159 ** zDb is not NULL (or a zero length string) and is not the name of any 9160 ** attached database, SQLITE_ERROR is returned to the caller. 9161 ** 9162 ** ^Unless it returns SQLITE_MISUSE, 9163 ** the sqlite3_wal_checkpoint_v2() interface 9164 ** sets the error information that is queried by 9165 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 9166 ** 9167 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 9168 ** from SQL. 9169 */ 9170 SQLITE_API int sqlite3_wal_checkpoint_v2( 9171 sqlite3 *db, /* Database handle */ 9172 const char *zDb, /* Name of attached database (or NULL) */ 9173 int eMode, /* SQLITE_CHECKPOINT_* value */ 9174 int *pnLog, /* OUT: Size of WAL log in frames */ 9175 int *pnCkpt /* OUT: Total number of frames checkpointed */ 9176 ); 9177 9178 /* 9179 ** CAPI3REF: Checkpoint Mode Values 9180 ** KEYWORDS: {checkpoint mode} 9181 ** 9182 ** These constants define all valid values for the "checkpoint mode" passed 9183 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 9184 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 9185 ** meaning of each of these checkpoint modes. 9186 */ 9187 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 9188 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 9189 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 9190 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 9191 9192 /* 9193 ** CAPI3REF: Virtual Table Interface Configuration 9194 ** 9195 ** This function may be called by either the [xConnect] or [xCreate] method 9196 ** of a [virtual table] implementation to configure 9197 ** various facets of the virtual table interface. 9198 ** 9199 ** If this interface is invoked outside the context of an xConnect or 9200 ** xCreate virtual table method then the behavior is undefined. 9201 ** 9202 ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the 9203 ** [database connection] in which the virtual table is being created and 9204 ** which is passed in as the first argument to the [xConnect] or [xCreate] 9205 ** method that is invoking sqlite3_vtab_config(). The C parameter is one 9206 ** of the [virtual table configuration options]. The presence and meaning 9207 ** of parameters after C depend on which [virtual table configuration option] 9208 ** is used. 9209 */ 9210 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 9211 9212 /* 9213 ** CAPI3REF: Virtual Table Configuration Options 9214 ** KEYWORDS: {virtual table configuration options} 9215 ** KEYWORDS: {virtual table configuration option} 9216 ** 9217 ** These macros define the various options to the 9218 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 9219 ** can use to customize and optimize their behavior. 9220 ** 9221 ** <dl> 9222 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 9223 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> 9224 ** <dd>Calls of the form 9225 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 9226 ** where X is an integer. If X is zero, then the [virtual table] whose 9227 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 9228 ** support constraints. In this configuration (which is the default) if 9229 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 9230 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 9231 ** specified as part of the users SQL statement, regardless of the actual 9232 ** ON CONFLICT mode specified. 9233 ** 9234 ** If X is non-zero, then the virtual table implementation guarantees 9235 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 9236 ** any modifications to internal or persistent data structures have been made. 9237 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 9238 ** is able to roll back a statement or database transaction, and abandon 9239 ** or continue processing the current SQL statement as appropriate. 9240 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 9241 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 9242 ** had been ABORT. 9243 ** 9244 ** Virtual table implementations that are required to handle OR REPLACE 9245 ** must do so within the [xUpdate] method. If a call to the 9246 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 9247 ** CONFLICT policy is REPLACE, the virtual table implementation should 9248 ** silently replace the appropriate rows within the xUpdate callback and 9249 ** return SQLITE_OK. Or, if this is not possible, it may return 9250 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 9251 ** constraint handling. 9252 ** </dd> 9253 ** 9254 ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt> 9255 ** <dd>Calls of the form 9256 ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the 9257 ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9258 ** prohibits that virtual table from being used from within triggers and 9259 ** views. 9260 ** </dd> 9261 ** 9262 ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt> 9263 ** <dd>Calls of the form 9264 ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the 9265 ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9266 ** identify that virtual table as being safe to use from within triggers 9267 ** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the 9268 ** virtual table can do no serious harm even if it is controlled by a 9269 ** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS 9270 ** flag unless absolutely necessary. 9271 ** </dd> 9272 ** </dl> 9273 */ 9274 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 9275 #define SQLITE_VTAB_INNOCUOUS 2 9276 #define SQLITE_VTAB_DIRECTONLY 3 9277 9278 /* 9279 ** CAPI3REF: Determine The Virtual Table Conflict Policy 9280 ** 9281 ** This function may only be called from within a call to the [xUpdate] method 9282 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 9283 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 9284 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 9285 ** of the SQL statement that triggered the call to the [xUpdate] method of the 9286 ** [virtual table]. 9287 */ 9288 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 9289 9290 /* 9291 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 9292 ** 9293 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 9294 ** method of a [virtual table], then it might return true if the 9295 ** column is being fetched as part of an UPDATE operation during which the 9296 ** column value will not change. The virtual table implementation can use 9297 ** this hint as permission to substitute a return value that is less 9298 ** expensive to compute and that the corresponding 9299 ** [xUpdate] method understands as a "no-change" value. 9300 ** 9301 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 9302 ** the column is not changed by the UPDATE statement, then the xColumn 9303 ** method can optionally return without setting a result, without calling 9304 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 9305 ** In that case, [sqlite3_value_nochange(X)] will return true for the 9306 ** same column in the [xUpdate] method. 9307 ** 9308 ** The sqlite3_vtab_nochange() routine is an optimization. Virtual table 9309 ** implementations should continue to give a correct answer even if the 9310 ** sqlite3_vtab_nochange() interface were to always return false. In the 9311 ** current implementation, the sqlite3_vtab_nochange() interface does always 9312 ** returns false for the enhanced [UPDATE FROM] statement. 9313 */ 9314 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 9315 9316 /* 9317 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint 9318 ** 9319 ** This function may only be called from within a call to the [xBestIndex] 9320 ** method of a [virtual table]. 9321 ** 9322 ** The first argument must be the sqlite3_index_info object that is the 9323 ** first parameter to the xBestIndex() method. The second argument must be 9324 ** an index into the aConstraint[] array belonging to the sqlite3_index_info 9325 ** structure passed to xBestIndex. This function returns a pointer to a buffer 9326 ** containing the name of the collation sequence for the corresponding 9327 ** constraint. 9328 */ 9329 SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 9330 9331 /* 9332 ** CAPI3REF: Conflict resolution modes 9333 ** KEYWORDS: {conflict resolution mode} 9334 ** 9335 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 9336 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 9337 ** is for the SQL statement being evaluated. 9338 ** 9339 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 9340 ** return value from the [sqlite3_set_authorizer()] callback and that 9341 ** [SQLITE_ABORT] is also a [result code]. 9342 */ 9343 #define SQLITE_ROLLBACK 1 9344 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 9345 #define SQLITE_FAIL 3 9346 /* #define SQLITE_ABORT 4 // Also an error code */ 9347 #define SQLITE_REPLACE 5 9348 9349 /* 9350 ** CAPI3REF: Prepared Statement Scan Status Opcodes 9351 ** KEYWORDS: {scanstatus options} 9352 ** 9353 ** The following constants can be used for the T parameter to the 9354 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 9355 ** different metric for sqlite3_stmt_scanstatus() to return. 9356 ** 9357 ** When the value returned to V is a string, space to hold that string is 9358 ** managed by the prepared statement S and will be automatically freed when 9359 ** S is finalized. 9360 ** 9361 ** <dl> 9362 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 9363 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 9364 ** set to the total number of times that the X-th loop has run.</dd> 9365 ** 9366 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 9367 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 9368 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 9369 ** 9370 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 9371 ** <dd>^The "double" variable pointed to by the V parameter will be set to the 9372 ** query planner's estimate for the average number of rows output from each 9373 ** iteration of the X-th loop. If the query planner's estimates was accurate, 9374 ** then this value will approximate the quotient NVISIT/NLOOP and the 9375 ** product of this value for all prior loops with the same SELECTID will 9376 ** be the NLOOP value for the current loop. 9377 ** 9378 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 9379 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 9380 ** to a zero-terminated UTF-8 string containing the name of the index or table 9381 ** used for the X-th loop. 9382 ** 9383 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 9384 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 9385 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 9386 ** description for the X-th loop. 9387 ** 9388 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 9389 ** <dd>^The "int" variable pointed to by the V parameter will be set to the 9390 ** "select-id" for the X-th loop. The select-id identifies which query or 9391 ** subquery the loop is part of. The main query has a select-id of zero. 9392 ** The select-id is the same value as is output in the first column 9393 ** of an [EXPLAIN QUERY PLAN] query. 9394 ** </dl> 9395 */ 9396 #define SQLITE_SCANSTAT_NLOOP 0 9397 #define SQLITE_SCANSTAT_NVISIT 1 9398 #define SQLITE_SCANSTAT_EST 2 9399 #define SQLITE_SCANSTAT_NAME 3 9400 #define SQLITE_SCANSTAT_EXPLAIN 4 9401 #define SQLITE_SCANSTAT_SELECTID 5 9402 9403 /* 9404 ** CAPI3REF: Prepared Statement Scan Status 9405 ** METHOD: sqlite3_stmt 9406 ** 9407 ** This interface returns information about the predicted and measured 9408 ** performance for pStmt. Advanced applications can use this 9409 ** interface to compare the predicted and the measured performance and 9410 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 9411 ** 9412 ** Since this interface is expected to be rarely used, it is only 9413 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 9414 ** compile-time option. 9415 ** 9416 ** The "iScanStatusOp" parameter determines which status information to return. 9417 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 9418 ** of this interface is undefined. 9419 ** ^The requested measurement is written into a variable pointed to by 9420 ** the "pOut" parameter. 9421 ** Parameter "idx" identifies the specific loop to retrieve statistics for. 9422 ** Loops are numbered starting from zero. ^If idx is out of range - less than 9423 ** zero or greater than or equal to the total number of loops used to implement 9424 ** the statement - a non-zero value is returned and the variable that pOut 9425 ** points to is unchanged. 9426 ** 9427 ** ^Statistics might not be available for all loops in all statements. ^In cases 9428 ** where there exist loops with no available statistics, this function behaves 9429 ** as if the loop did not exist - it returns non-zero and leave the variable 9430 ** that pOut points to unchanged. 9431 ** 9432 ** See also: [sqlite3_stmt_scanstatus_reset()] 9433 */ 9434 SQLITE_API int sqlite3_stmt_scanstatus( 9435 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 9436 int idx, /* Index of loop to report on */ 9437 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 9438 void *pOut /* Result written here */ 9439 ); 9440 9441 /* 9442 ** CAPI3REF: Zero Scan-Status Counters 9443 ** METHOD: sqlite3_stmt 9444 ** 9445 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 9446 ** 9447 ** This API is only available if the library is built with pre-processor 9448 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 9449 */ 9450 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 9451 9452 /* 9453 ** CAPI3REF: Flush caches to disk mid-transaction 9454 ** METHOD: sqlite3 9455 ** 9456 ** ^If a write-transaction is open on [database connection] D when the 9457 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 9458 ** pages in the pager-cache that are not currently in use are written out 9459 ** to disk. A dirty page may be in use if a database cursor created by an 9460 ** active SQL statement is reading from it, or if it is page 1 of a database 9461 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 9462 ** interface flushes caches for all schemas - "main", "temp", and 9463 ** any [attached] databases. 9464 ** 9465 ** ^If this function needs to obtain extra database locks before dirty pages 9466 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 9467 ** immediately and there is a busy-handler callback configured, it is invoked 9468 ** in the usual manner. ^If the required lock still cannot be obtained, then 9469 ** the database is skipped and an attempt made to flush any dirty pages 9470 ** belonging to the next (if any) database. ^If any databases are skipped 9471 ** because locks cannot be obtained, but no other error occurs, this 9472 ** function returns SQLITE_BUSY. 9473 ** 9474 ** ^If any other error occurs while flushing dirty pages to disk (for 9475 ** example an IO error or out-of-memory condition), then processing is 9476 ** abandoned and an SQLite [error code] is returned to the caller immediately. 9477 ** 9478 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 9479 ** 9480 ** ^This function does not set the database handle error code or message 9481 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 9482 */ 9483 SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 9484 9485 /* 9486 ** CAPI3REF: The pre-update hook. 9487 ** METHOD: sqlite3 9488 ** 9489 ** ^These interfaces are only available if SQLite is compiled using the 9490 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 9491 ** 9492 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 9493 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 9494 ** on a database table. 9495 ** ^At most one preupdate hook may be registered at a time on a single 9496 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 9497 ** the previous setting. 9498 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 9499 ** with a NULL pointer as the second parameter. 9500 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 9501 ** the first parameter to callbacks. 9502 ** 9503 ** ^The preupdate hook only fires for changes to real database tables; the 9504 ** preupdate hook is not invoked for changes to [virtual tables] or to 9505 ** system tables like sqlite_sequence or sqlite_stat1. 9506 ** 9507 ** ^The second parameter to the preupdate callback is a pointer to 9508 ** the [database connection] that registered the preupdate hook. 9509 ** ^The third parameter to the preupdate callback is one of the constants 9510 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 9511 ** kind of update operation that is about to occur. 9512 ** ^(The fourth parameter to the preupdate callback is the name of the 9513 ** database within the database connection that is being modified. This 9514 ** will be "main" for the main database or "temp" for TEMP tables or 9515 ** the name given after the AS keyword in the [ATTACH] statement for attached 9516 ** databases.)^ 9517 ** ^The fifth parameter to the preupdate callback is the name of the 9518 ** table that is being modified. 9519 ** 9520 ** For an UPDATE or DELETE operation on a [rowid table], the sixth 9521 ** parameter passed to the preupdate callback is the initial [rowid] of the 9522 ** row being modified or deleted. For an INSERT operation on a rowid table, 9523 ** or any operation on a WITHOUT ROWID table, the value of the sixth 9524 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the 9525 ** seventh parameter is the final rowid value of the row being inserted 9526 ** or updated. The value of the seventh parameter passed to the callback 9527 ** function is not defined for operations on WITHOUT ROWID tables, or for 9528 ** DELETE operations on rowid tables. 9529 ** 9530 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 9531 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 9532 ** provide additional information about a preupdate event. These routines 9533 ** may only be called from within a preupdate callback. Invoking any of 9534 ** these routines from outside of a preupdate callback or with a 9535 ** [database connection] pointer that is different from the one supplied 9536 ** to the preupdate callback results in undefined and probably undesirable 9537 ** behavior. 9538 ** 9539 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 9540 ** in the row that is being inserted, updated, or deleted. 9541 ** 9542 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 9543 ** a [protected sqlite3_value] that contains the value of the Nth column of 9544 ** the table row before it is updated. The N parameter must be between 0 9545 ** and one less than the number of columns or the behavior will be 9546 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 9547 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 9548 ** behavior is undefined. The [sqlite3_value] that P points to 9549 ** will be destroyed when the preupdate callback returns. 9550 ** 9551 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 9552 ** a [protected sqlite3_value] that contains the value of the Nth column of 9553 ** the table row after it is updated. The N parameter must be between 0 9554 ** and one less than the number of columns or the behavior will be 9555 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 9556 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 9557 ** behavior is undefined. The [sqlite3_value] that P points to 9558 ** will be destroyed when the preupdate callback returns. 9559 ** 9560 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 9561 ** callback was invoked as a result of a direct insert, update, or delete 9562 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 9563 ** triggers; or 2 for changes resulting from triggers called by top-level 9564 ** triggers; and so forth. 9565 ** 9566 ** When the [sqlite3_blob_write()] API is used to update a blob column, 9567 ** the pre-update hook is invoked with SQLITE_DELETE. This is because the 9568 ** in this case the new values are not available. In this case, when a 9569 ** callback made with op==SQLITE_DELETE is actuall a write using the 9570 ** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns 9571 ** the index of the column being written. In other cases, where the 9572 ** pre-update hook is being invoked for some other reason, including a 9573 ** regular DELETE, sqlite3_preupdate_blobwrite() returns -1. 9574 ** 9575 ** See also: [sqlite3_update_hook()] 9576 */ 9577 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 9578 SQLITE_API void *sqlite3_preupdate_hook( 9579 sqlite3 *db, 9580 void(*xPreUpdate)( 9581 void *pCtx, /* Copy of third arg to preupdate_hook() */ 9582 sqlite3 *db, /* Database handle */ 9583 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 9584 char const *zDb, /* Database name */ 9585 char const *zName, /* Table name */ 9586 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 9587 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 9588 ), 9589 void* 9590 ); 9591 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 9592 SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 9593 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 9594 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 9595 SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *); 9596 #endif 9597 9598 /* 9599 ** CAPI3REF: Low-level system error code 9600 ** METHOD: sqlite3 9601 ** 9602 ** ^Attempt to return the underlying operating system error code or error 9603 ** number that caused the most recent I/O error or failure to open a file. 9604 ** The return value is OS-dependent. For example, on unix systems, after 9605 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 9606 ** called to get back the underlying "errno" that caused the problem, such 9607 ** as ENOSPC, EAUTH, EISDIR, and so forth. 9608 */ 9609 SQLITE_API int sqlite3_system_errno(sqlite3*); 9610 9611 /* 9612 ** CAPI3REF: Database Snapshot 9613 ** KEYWORDS: {snapshot} {sqlite3_snapshot} 9614 ** 9615 ** An instance of the snapshot object records the state of a [WAL mode] 9616 ** database for some specific point in history. 9617 ** 9618 ** In [WAL mode], multiple [database connections] that are open on the 9619 ** same database file can each be reading a different historical version 9620 ** of the database file. When a [database connection] begins a read 9621 ** transaction, that connection sees an unchanging copy of the database 9622 ** as it existed for the point in time when the transaction first started. 9623 ** Subsequent changes to the database from other connections are not seen 9624 ** by the reader until a new read transaction is started. 9625 ** 9626 ** The sqlite3_snapshot object records state information about an historical 9627 ** version of the database file so that it is possible to later open a new read 9628 ** transaction that sees that historical version of the database rather than 9629 ** the most recent version. 9630 */ 9631 typedef struct sqlite3_snapshot { 9632 unsigned char hidden[48]; 9633 } sqlite3_snapshot; 9634 9635 /* 9636 ** CAPI3REF: Record A Database Snapshot 9637 ** CONSTRUCTOR: sqlite3_snapshot 9638 ** 9639 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 9640 ** new [sqlite3_snapshot] object that records the current state of 9641 ** schema S in database connection D. ^On success, the 9642 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 9643 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 9644 ** If there is not already a read-transaction open on schema S when 9645 ** this function is called, one is opened automatically. 9646 ** 9647 ** The following must be true for this function to succeed. If any of 9648 ** the following statements are false when sqlite3_snapshot_get() is 9649 ** called, SQLITE_ERROR is returned. The final value of *P is undefined 9650 ** in this case. 9651 ** 9652 ** <ul> 9653 ** <li> The database handle must not be in [autocommit mode]. 9654 ** 9655 ** <li> Schema S of [database connection] D must be a [WAL mode] database. 9656 ** 9657 ** <li> There must not be a write transaction open on schema S of database 9658 ** connection D. 9659 ** 9660 ** <li> One or more transactions must have been written to the current wal 9661 ** file since it was created on disk (by any connection). This means 9662 ** that a snapshot cannot be taken on a wal mode database with no wal 9663 ** file immediately after it is first opened. At least one transaction 9664 ** must be written to it first. 9665 ** </ul> 9666 ** 9667 ** This function may also return SQLITE_NOMEM. If it is called with the 9668 ** database handle in autocommit mode but fails for some other reason, 9669 ** whether or not a read transaction is opened on schema S is undefined. 9670 ** 9671 ** The [sqlite3_snapshot] object returned from a successful call to 9672 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 9673 ** to avoid a memory leak. 9674 ** 9675 ** The [sqlite3_snapshot_get()] interface is only available when the 9676 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9677 */ 9678 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 9679 sqlite3 *db, 9680 const char *zSchema, 9681 sqlite3_snapshot **ppSnapshot 9682 ); 9683 9684 /* 9685 ** CAPI3REF: Start a read transaction on an historical snapshot 9686 ** METHOD: sqlite3_snapshot 9687 ** 9688 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 9689 ** transaction or upgrades an existing one for schema S of 9690 ** [database connection] D such that the read transaction refers to 9691 ** historical [snapshot] P, rather than the most recent change to the 9692 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 9693 ** on success or an appropriate [error code] if it fails. 9694 ** 9695 ** ^In order to succeed, the database connection must not be in 9696 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 9697 ** is already a read transaction open on schema S, then the database handle 9698 ** must have no active statements (SELECT statements that have been passed 9699 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 9700 ** SQLITE_ERROR is returned if either of these conditions is violated, or 9701 ** if schema S does not exist, or if the snapshot object is invalid. 9702 ** 9703 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified 9704 ** snapshot has been overwritten by a [checkpoint]. In this case 9705 ** SQLITE_ERROR_SNAPSHOT is returned. 9706 ** 9707 ** If there is already a read transaction open when this function is 9708 ** invoked, then the same read transaction remains open (on the same 9709 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 9710 ** is returned. If another error code - for example SQLITE_PROTOCOL or an 9711 ** SQLITE_IOERR error code - is returned, then the final state of the 9712 ** read transaction is undefined. If SQLITE_OK is returned, then the 9713 ** read transaction is now open on database snapshot P. 9714 ** 9715 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 9716 ** database connection D does not know that the database file for 9717 ** schema S is in [WAL mode]. A database connection might not know 9718 ** that the database file is in [WAL mode] if there has been no prior 9719 ** I/O on that database connection, or if the database entered [WAL mode] 9720 ** after the most recent I/O on the database connection.)^ 9721 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 9722 ** database connection in order to make it ready to use snapshots.) 9723 ** 9724 ** The [sqlite3_snapshot_open()] interface is only available when the 9725 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9726 */ 9727 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 9728 sqlite3 *db, 9729 const char *zSchema, 9730 sqlite3_snapshot *pSnapshot 9731 ); 9732 9733 /* 9734 ** CAPI3REF: Destroy a snapshot 9735 ** DESTRUCTOR: sqlite3_snapshot 9736 ** 9737 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 9738 ** The application must eventually free every [sqlite3_snapshot] object 9739 ** using this routine to avoid a memory leak. 9740 ** 9741 ** The [sqlite3_snapshot_free()] interface is only available when the 9742 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9743 */ 9744 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 9745 9746 /* 9747 ** CAPI3REF: Compare the ages of two snapshot handles. 9748 ** METHOD: sqlite3_snapshot 9749 ** 9750 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 9751 ** of two valid snapshot handles. 9752 ** 9753 ** If the two snapshot handles are not associated with the same database 9754 ** file, the result of the comparison is undefined. 9755 ** 9756 ** Additionally, the result of the comparison is only valid if both of the 9757 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 9758 ** last time the wal file was deleted. The wal file is deleted when the 9759 ** database is changed back to rollback mode or when the number of database 9760 ** clients drops to zero. If either snapshot handle was obtained before the 9761 ** wal file was last deleted, the value returned by this function 9762 ** is undefined. 9763 ** 9764 ** Otherwise, this API returns a negative value if P1 refers to an older 9765 ** snapshot than P2, zero if the two handles refer to the same database 9766 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 9767 ** 9768 ** This interface is only available if SQLite is compiled with the 9769 ** [SQLITE_ENABLE_SNAPSHOT] option. 9770 */ 9771 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 9772 sqlite3_snapshot *p1, 9773 sqlite3_snapshot *p2 9774 ); 9775 9776 /* 9777 ** CAPI3REF: Recover snapshots from a wal file 9778 ** METHOD: sqlite3_snapshot 9779 ** 9780 ** If a [WAL file] remains on disk after all database connections close 9781 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 9782 ** or because the last process to have the database opened exited without 9783 ** calling [sqlite3_close()]) and a new connection is subsequently opened 9784 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 9785 ** will only be able to open the last transaction added to the WAL file 9786 ** even though the WAL file contains other valid transactions. 9787 ** 9788 ** This function attempts to scan the WAL file associated with database zDb 9789 ** of database handle db and make all valid snapshots available to 9790 ** sqlite3_snapshot_open(). It is an error if there is already a read 9791 ** transaction open on the database, or if the database is not a WAL mode 9792 ** database. 9793 ** 9794 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 9795 ** 9796 ** This interface is only available if SQLite is compiled with the 9797 ** [SQLITE_ENABLE_SNAPSHOT] option. 9798 */ 9799 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 9800 9801 /* 9802 ** CAPI3REF: Serialize a database 9803 ** 9804 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 9805 ** that is a serialization of the S database on [database connection] D. 9806 ** If P is not a NULL pointer, then the size of the database in bytes 9807 ** is written into *P. 9808 ** 9809 ** For an ordinary on-disk database file, the serialization is just a 9810 ** copy of the disk file. For an in-memory database or a "TEMP" database, 9811 ** the serialization is the same sequence of bytes which would be written 9812 ** to disk if that database where backed up to disk. 9813 ** 9814 ** The usual case is that sqlite3_serialize() copies the serialization of 9815 ** the database into memory obtained from [sqlite3_malloc64()] and returns 9816 ** a pointer to that memory. The caller is responsible for freeing the 9817 ** returned value to avoid a memory leak. However, if the F argument 9818 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 9819 ** are made, and the sqlite3_serialize() function will return a pointer 9820 ** to the contiguous memory representation of the database that SQLite 9821 ** is currently using for that database, or NULL if the no such contiguous 9822 ** memory representation of the database exists. A contiguous memory 9823 ** representation of the database will usually only exist if there has 9824 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 9825 ** values of D and S. 9826 ** The size of the database is written into *P even if the 9827 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 9828 ** of the database exists. 9829 ** 9830 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 9831 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 9832 ** allocation error occurs. 9833 ** 9834 ** This interface is omitted if SQLite is compiled with the 9835 ** [SQLITE_OMIT_DESERIALIZE] option. 9836 */ 9837 SQLITE_API unsigned char *sqlite3_serialize( 9838 sqlite3 *db, /* The database connection */ 9839 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 9840 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 9841 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 9842 ); 9843 9844 /* 9845 ** CAPI3REF: Flags for sqlite3_serialize 9846 ** 9847 ** Zero or more of the following constants can be OR-ed together for 9848 ** the F argument to [sqlite3_serialize(D,S,P,F)]. 9849 ** 9850 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 9851 ** a pointer to contiguous in-memory database that it is currently using, 9852 ** without making a copy of the database. If SQLite is not currently using 9853 ** a contiguous in-memory database, then this option causes 9854 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 9855 ** using a contiguous in-memory database if it has been initialized by a 9856 ** prior call to [sqlite3_deserialize()]. 9857 */ 9858 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 9859 9860 /* 9861 ** CAPI3REF: Deserialize a database 9862 ** 9863 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 9864 ** [database connection] D to disconnect from database S and then 9865 ** reopen S as an in-memory database based on the serialization contained 9866 ** in P. The serialized database P is N bytes in size. M is the size of 9867 ** the buffer P, which might be larger than N. If M is larger than N, and 9868 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 9869 ** permitted to add content to the in-memory database as long as the total 9870 ** size does not exceed M bytes. 9871 ** 9872 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 9873 ** invoke sqlite3_free() on the serialization buffer when the database 9874 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 9875 ** SQLite will try to increase the buffer size using sqlite3_realloc64() 9876 ** if writes on the database cause it to grow larger than M bytes. 9877 ** 9878 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 9879 ** database is currently in a read transaction or is involved in a backup 9880 ** operation. 9881 ** 9882 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 9883 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 9884 ** [sqlite3_free()] is invoked on argument P prior to returning. 9885 ** 9886 ** This interface is omitted if SQLite is compiled with the 9887 ** [SQLITE_OMIT_DESERIALIZE] option. 9888 */ 9889 SQLITE_API int sqlite3_deserialize( 9890 sqlite3 *db, /* The database connection */ 9891 const char *zSchema, /* Which DB to reopen with the deserialization */ 9892 unsigned char *pData, /* The serialized database content */ 9893 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 9894 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 9895 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 9896 ); 9897 9898 /* 9899 ** CAPI3REF: Flags for sqlite3_deserialize() 9900 ** 9901 ** The following are allowed values for 6th argument (the F argument) to 9902 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 9903 ** 9904 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 9905 ** in the P argument is held in memory obtained from [sqlite3_malloc64()] 9906 ** and that SQLite should take ownership of this memory and automatically 9907 ** free it when it has finished using it. Without this flag, the caller 9908 ** is responsible for freeing any dynamically allocated memory. 9909 ** 9910 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 9911 ** grow the size of the database using calls to [sqlite3_realloc64()]. This 9912 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 9913 ** Without this flag, the deserialized database cannot increase in size beyond 9914 ** the number of bytes specified by the M parameter. 9915 ** 9916 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 9917 ** should be treated as read-only. 9918 */ 9919 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 9920 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 9921 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 9922 9923 /* 9924 ** Undo the hack that converts floating point types to integer for 9925 ** builds on processors without floating point support. 9926 */ 9927 #ifdef SQLITE_OMIT_FLOATING_POINT 9928 # undef double 9929 #endif 9930 9931 #ifdef __cplusplus 9932 } /* End of the 'extern "C"' block */ 9933 #endif 9934 #endif /* SQLITE3_H */ 9935 9936 /******** Begin file sqlite3rtree.h *********/ 9937 /* 9938 ** 2010 August 30 9939 ** 9940 ** The author disclaims copyright to this source code. In place of 9941 ** a legal notice, here is a blessing: 9942 ** 9943 ** May you do good and not evil. 9944 ** May you find forgiveness for yourself and forgive others. 9945 ** May you share freely, never taking more than you give. 9946 ** 9947 ************************************************************************* 9948 */ 9949 9950 #ifndef _SQLITE3RTREE_H_ 9951 #define _SQLITE3RTREE_H_ 9952 9953 9954 #ifdef __cplusplus 9955 extern "C" { 9956 #endif 9957 9958 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 9959 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 9960 9961 /* The double-precision datatype used by RTree depends on the 9962 ** SQLITE_RTREE_INT_ONLY compile-time option. 9963 */ 9964 #ifdef SQLITE_RTREE_INT_ONLY 9965 typedef sqlite3_int64 sqlite3_rtree_dbl; 9966 #else 9967 typedef double sqlite3_rtree_dbl; 9968 #endif 9969 9970 /* 9971 ** Register a geometry callback named zGeom that can be used as part of an 9972 ** R-Tree geometry query as follows: 9973 ** 9974 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 9975 */ 9976 SQLITE_API int sqlite3_rtree_geometry_callback( 9977 sqlite3 *db, 9978 const char *zGeom, 9979 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 9980 void *pContext 9981 ); 9982 9983 9984 /* 9985 ** A pointer to a structure of the following type is passed as the first 9986 ** argument to callbacks registered using rtree_geometry_callback(). 9987 */ 9988 struct sqlite3_rtree_geometry { 9989 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 9990 int nParam; /* Size of array aParam[] */ 9991 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 9992 void *pUser; /* Callback implementation user data */ 9993 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 9994 }; 9995 9996 /* 9997 ** Register a 2nd-generation geometry callback named zScore that can be 9998 ** used as part of an R-Tree geometry query as follows: 9999 ** 10000 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 10001 */ 10002 SQLITE_API int sqlite3_rtree_query_callback( 10003 sqlite3 *db, 10004 const char *zQueryFunc, 10005 int (*xQueryFunc)(sqlite3_rtree_query_info*), 10006 void *pContext, 10007 void (*xDestructor)(void*) 10008 ); 10009 10010 10011 /* 10012 ** A pointer to a structure of the following type is passed as the 10013 ** argument to scored geometry callback registered using 10014 ** sqlite3_rtree_query_callback(). 10015 ** 10016 ** Note that the first 5 fields of this structure are identical to 10017 ** sqlite3_rtree_geometry. This structure is a subclass of 10018 ** sqlite3_rtree_geometry. 10019 */ 10020 struct sqlite3_rtree_query_info { 10021 void *pContext; /* pContext from when function registered */ 10022 int nParam; /* Number of function parameters */ 10023 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 10024 void *pUser; /* callback can use this, if desired */ 10025 void (*xDelUser)(void*); /* function to free pUser */ 10026 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 10027 unsigned int *anQueue; /* Number of pending entries in the queue */ 10028 int nCoord; /* Number of coordinates */ 10029 int iLevel; /* Level of current node or entry */ 10030 int mxLevel; /* The largest iLevel value in the tree */ 10031 sqlite3_int64 iRowid; /* Rowid for current entry */ 10032 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 10033 int eParentWithin; /* Visibility of parent node */ 10034 int eWithin; /* OUT: Visibility */ 10035 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 10036 /* The following fields are only available in 3.8.11 and later */ 10037 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 10038 }; 10039 10040 /* 10041 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 10042 */ 10043 #define NOT_WITHIN 0 /* Object completely outside of query region */ 10044 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 10045 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 10046 10047 10048 #ifdef __cplusplus 10049 } /* end of the 'extern "C"' block */ 10050 #endif 10051 10052 #endif /* ifndef _SQLITE3RTREE_H_ */ 10053 10054 /******** End of sqlite3rtree.h *********/ 10055 /******** Begin file sqlite3session.h *********/ 10056 10057 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 10058 #define __SQLITESESSION_H_ 1 10059 10060 /* 10061 ** Make sure we can call this stuff from C++. 10062 */ 10063 #ifdef __cplusplus 10064 extern "C" { 10065 #endif 10066 10067 10068 /* 10069 ** CAPI3REF: Session Object Handle 10070 ** 10071 ** An instance of this object is a [session] that can be used to 10072 ** record changes to a database. 10073 */ 10074 typedef struct sqlite3_session sqlite3_session; 10075 10076 /* 10077 ** CAPI3REF: Changeset Iterator Handle 10078 ** 10079 ** An instance of this object acts as a cursor for iterating 10080 ** over the elements of a [changeset] or [patchset]. 10081 */ 10082 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 10083 10084 /* 10085 ** CAPI3REF: Create A New Session Object 10086 ** CONSTRUCTOR: sqlite3_session 10087 ** 10088 ** Create a new session object attached to database handle db. If successful, 10089 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 10090 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 10091 ** error code (e.g. SQLITE_NOMEM) is returned. 10092 ** 10093 ** It is possible to create multiple session objects attached to a single 10094 ** database handle. 10095 ** 10096 ** Session objects created using this function should be deleted using the 10097 ** [sqlite3session_delete()] function before the database handle that they 10098 ** are attached to is itself closed. If the database handle is closed before 10099 ** the session object is deleted, then the results of calling any session 10100 ** module function, including [sqlite3session_delete()] on the session object 10101 ** are undefined. 10102 ** 10103 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 10104 ** is not possible for an application to register a pre-update hook on a 10105 ** database handle that has one or more session objects attached. Nor is 10106 ** it possible to create a session object attached to a database handle for 10107 ** which a pre-update hook is already defined. The results of attempting 10108 ** either of these things are undefined. 10109 ** 10110 ** The session object will be used to create changesets for tables in 10111 ** database zDb, where zDb is either "main", or "temp", or the name of an 10112 ** attached database. It is not an error if database zDb is not attached 10113 ** to the database when the session object is created. 10114 */ 10115 SQLITE_API int sqlite3session_create( 10116 sqlite3 *db, /* Database handle */ 10117 const char *zDb, /* Name of db (e.g. "main") */ 10118 sqlite3_session **ppSession /* OUT: New session object */ 10119 ); 10120 10121 /* 10122 ** CAPI3REF: Delete A Session Object 10123 ** DESTRUCTOR: sqlite3_session 10124 ** 10125 ** Delete a session object previously allocated using 10126 ** [sqlite3session_create()]. Once a session object has been deleted, the 10127 ** results of attempting to use pSession with any other session module 10128 ** function are undefined. 10129 ** 10130 ** Session objects must be deleted before the database handle to which they 10131 ** are attached is closed. Refer to the documentation for 10132 ** [sqlite3session_create()] for details. 10133 */ 10134 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 10135 10136 /* 10137 ** CAPIREF: Conigure a Session Object 10138 ** METHOD: sqlite3_session 10139 ** 10140 ** This method is used to configure a session object after it has been 10141 ** created. At present the only valid value for the second parameter is 10142 ** [SQLITE_SESSION_OBJCONFIG_SIZE]. 10143 ** 10144 ** Arguments for sqlite3session_object_config() 10145 ** 10146 ** The following values may passed as the the 4th parameter to 10147 ** sqlite3session_object_config(). 10148 ** 10149 ** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd> 10150 ** This option is used to set, clear or query the flag that enables 10151 ** the [sqlite3session_changeset_size()] API. Because it imposes some 10152 ** computational overhead, this API is disabled by default. Argument 10153 ** pArg must point to a value of type (int). If the value is initially 10154 ** 0, then the sqlite3session_changeset_size() API is disabled. If it 10155 ** is greater than 0, then the same API is enabled. Or, if the initial 10156 ** value is less than zero, no change is made. In all cases the (int) 10157 ** variable is set to 1 if the sqlite3session_changeset_size() API is 10158 ** enabled following the current call, or 0 otherwise. 10159 ** 10160 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after 10161 ** the first table has been attached to the session object. 10162 */ 10163 SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg); 10164 10165 /* 10166 */ 10167 #define SQLITE_SESSION_OBJCONFIG_SIZE 1 10168 10169 /* 10170 ** CAPI3REF: Enable Or Disable A Session Object 10171 ** METHOD: sqlite3_session 10172 ** 10173 ** Enable or disable the recording of changes by a session object. When 10174 ** enabled, a session object records changes made to the database. When 10175 ** disabled - it does not. A newly created session object is enabled. 10176 ** Refer to the documentation for [sqlite3session_changeset()] for further 10177 ** details regarding how enabling and disabling a session object affects 10178 ** the eventual changesets. 10179 ** 10180 ** Passing zero to this function disables the session. Passing a value 10181 ** greater than zero enables it. Passing a value less than zero is a 10182 ** no-op, and may be used to query the current state of the session. 10183 ** 10184 ** The return value indicates the final state of the session object: 0 if 10185 ** the session is disabled, or 1 if it is enabled. 10186 */ 10187 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 10188 10189 /* 10190 ** CAPI3REF: Set Or Clear the Indirect Change Flag 10191 ** METHOD: sqlite3_session 10192 ** 10193 ** Each change recorded by a session object is marked as either direct or 10194 ** indirect. A change is marked as indirect if either: 10195 ** 10196 ** <ul> 10197 ** <li> The session object "indirect" flag is set when the change is 10198 ** made, or 10199 ** <li> The change is made by an SQL trigger or foreign key action 10200 ** instead of directly as a result of a users SQL statement. 10201 ** </ul> 10202 ** 10203 ** If a single row is affected by more than one operation within a session, 10204 ** then the change is considered indirect if all operations meet the criteria 10205 ** for an indirect change above, or direct otherwise. 10206 ** 10207 ** This function is used to set, clear or query the session object indirect 10208 ** flag. If the second argument passed to this function is zero, then the 10209 ** indirect flag is cleared. If it is greater than zero, the indirect flag 10210 ** is set. Passing a value less than zero does not modify the current value 10211 ** of the indirect flag, and may be used to query the current state of the 10212 ** indirect flag for the specified session object. 10213 ** 10214 ** The return value indicates the final state of the indirect flag: 0 if 10215 ** it is clear, or 1 if it is set. 10216 */ 10217 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 10218 10219 /* 10220 ** CAPI3REF: Attach A Table To A Session Object 10221 ** METHOD: sqlite3_session 10222 ** 10223 ** If argument zTab is not NULL, then it is the name of a table to attach 10224 ** to the session object passed as the first argument. All subsequent changes 10225 ** made to the table while the session object is enabled will be recorded. See 10226 ** documentation for [sqlite3session_changeset()] for further details. 10227 ** 10228 ** Or, if argument zTab is NULL, then changes are recorded for all tables 10229 ** in the database. If additional tables are added to the database (by 10230 ** executing "CREATE TABLE" statements) after this call is made, changes for 10231 ** the new tables are also recorded. 10232 ** 10233 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 10234 ** defined as part of their CREATE TABLE statement. It does not matter if the 10235 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 10236 ** KEY may consist of a single column, or may be a composite key. 10237 ** 10238 ** It is not an error if the named table does not exist in the database. Nor 10239 ** is it an error if the named table does not have a PRIMARY KEY. However, 10240 ** no changes will be recorded in either of these scenarios. 10241 ** 10242 ** Changes are not recorded for individual rows that have NULL values stored 10243 ** in one or more of their PRIMARY KEY columns. 10244 ** 10245 ** SQLITE_OK is returned if the call completes without error. Or, if an error 10246 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 10247 ** 10248 ** <h3>Special sqlite_stat1 Handling</h3> 10249 ** 10250 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 10251 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 10252 ** <pre> 10253 ** CREATE TABLE sqlite_stat1(tbl,idx,stat) 10254 ** </pre> 10255 ** 10256 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 10257 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 10258 ** are recorded for rows for which (idx IS NULL) is true. However, for such 10259 ** rows a zero-length blob (SQL value X'') is stored in the changeset or 10260 ** patchset instead of a NULL value. This allows such changesets to be 10261 ** manipulated by legacy implementations of sqlite3changeset_invert(), 10262 ** concat() and similar. 10263 ** 10264 ** The sqlite3changeset_apply() function automatically converts the 10265 ** zero-length blob back to a NULL value when updating the sqlite_stat1 10266 ** table. However, if the application calls sqlite3changeset_new(), 10267 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 10268 ** iterator directly (including on a changeset iterator passed to a 10269 ** conflict-handler callback) then the X'' value is returned. The application 10270 ** must translate X'' to NULL itself if required. 10271 ** 10272 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture 10273 ** changes made to the sqlite_stat1 table. Legacy versions of the 10274 ** sqlite3changeset_apply() function silently ignore any modifications to the 10275 ** sqlite_stat1 table that are part of a changeset or patchset. 10276 */ 10277 SQLITE_API int sqlite3session_attach( 10278 sqlite3_session *pSession, /* Session object */ 10279 const char *zTab /* Table name */ 10280 ); 10281 10282 /* 10283 ** CAPI3REF: Set a table filter on a Session Object. 10284 ** METHOD: sqlite3_session 10285 ** 10286 ** The second argument (xFilter) is the "filter callback". For changes to rows 10287 ** in tables that are not attached to the Session object, the filter is called 10288 ** to determine whether changes to the table's rows should be tracked or not. 10289 ** If xFilter returns 0, changes are not tracked. Note that once a table is 10290 ** attached, xFilter will not be called again. 10291 */ 10292 SQLITE_API void sqlite3session_table_filter( 10293 sqlite3_session *pSession, /* Session object */ 10294 int(*xFilter)( 10295 void *pCtx, /* Copy of third arg to _filter_table() */ 10296 const char *zTab /* Table name */ 10297 ), 10298 void *pCtx /* First argument passed to xFilter */ 10299 ); 10300 10301 /* 10302 ** CAPI3REF: Generate A Changeset From A Session Object 10303 ** METHOD: sqlite3_session 10304 ** 10305 ** Obtain a changeset containing changes to the tables attached to the 10306 ** session object passed as the first argument. If successful, 10307 ** set *ppChangeset to point to a buffer containing the changeset 10308 ** and *pnChangeset to the size of the changeset in bytes before returning 10309 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 10310 ** zero and return an SQLite error code. 10311 ** 10312 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 10313 ** each representing a change to a single row of an attached table. An INSERT 10314 ** change contains the values of each field of a new database row. A DELETE 10315 ** contains the original values of each field of a deleted database row. An 10316 ** UPDATE change contains the original values of each field of an updated 10317 ** database row along with the updated values for each updated non-primary-key 10318 ** column. It is not possible for an UPDATE change to represent a change that 10319 ** modifies the values of primary key columns. If such a change is made, it 10320 ** is represented in a changeset as a DELETE followed by an INSERT. 10321 ** 10322 ** Changes are not recorded for rows that have NULL values stored in one or 10323 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 10324 ** no corresponding change is present in the changesets returned by this 10325 ** function. If an existing row with one or more NULL values stored in 10326 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 10327 ** only an INSERT is appears in the changeset. Similarly, if an existing row 10328 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 10329 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 10330 ** DELETE change only. 10331 ** 10332 ** The contents of a changeset may be traversed using an iterator created 10333 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 10334 ** a database with a compatible schema using the [sqlite3changeset_apply()] 10335 ** API. 10336 ** 10337 ** Within a changeset generated by this function, all changes related to a 10338 ** single table are grouped together. In other words, when iterating through 10339 ** a changeset or when applying a changeset to a database, all changes related 10340 ** to a single table are processed before moving on to the next table. Tables 10341 ** are sorted in the same order in which they were attached (or auto-attached) 10342 ** to the sqlite3_session object. The order in which the changes related to 10343 ** a single table are stored is undefined. 10344 ** 10345 ** Following a successful call to this function, it is the responsibility of 10346 ** the caller to eventually free the buffer that *ppChangeset points to using 10347 ** [sqlite3_free()]. 10348 ** 10349 ** <h3>Changeset Generation</h3> 10350 ** 10351 ** Once a table has been attached to a session object, the session object 10352 ** records the primary key values of all new rows inserted into the table. 10353 ** It also records the original primary key and other column values of any 10354 ** deleted or updated rows. For each unique primary key value, data is only 10355 ** recorded once - the first time a row with said primary key is inserted, 10356 ** updated or deleted in the lifetime of the session. 10357 ** 10358 ** There is one exception to the previous paragraph: when a row is inserted, 10359 ** updated or deleted, if one or more of its primary key columns contain a 10360 ** NULL value, no record of the change is made. 10361 ** 10362 ** The session object therefore accumulates two types of records - those 10363 ** that consist of primary key values only (created when the user inserts 10364 ** a new record) and those that consist of the primary key values and the 10365 ** original values of other table columns (created when the users deletes 10366 ** or updates a record). 10367 ** 10368 ** When this function is called, the requested changeset is created using 10369 ** both the accumulated records and the current contents of the database 10370 ** file. Specifically: 10371 ** 10372 ** <ul> 10373 ** <li> For each record generated by an insert, the database is queried 10374 ** for a row with a matching primary key. If one is found, an INSERT 10375 ** change is added to the changeset. If no such row is found, no change 10376 ** is added to the changeset. 10377 ** 10378 ** <li> For each record generated by an update or delete, the database is 10379 ** queried for a row with a matching primary key. If such a row is 10380 ** found and one or more of the non-primary key fields have been 10381 ** modified from their original values, an UPDATE change is added to 10382 ** the changeset. Or, if no such row is found in the table, a DELETE 10383 ** change is added to the changeset. If there is a row with a matching 10384 ** primary key in the database, but all fields contain their original 10385 ** values, no change is added to the changeset. 10386 ** </ul> 10387 ** 10388 ** This means, amongst other things, that if a row is inserted and then later 10389 ** deleted while a session object is active, neither the insert nor the delete 10390 ** will be present in the changeset. Or if a row is deleted and then later a 10391 ** row with the same primary key values inserted while a session object is 10392 ** active, the resulting changeset will contain an UPDATE change instead of 10393 ** a DELETE and an INSERT. 10394 ** 10395 ** When a session object is disabled (see the [sqlite3session_enable()] API), 10396 ** it does not accumulate records when rows are inserted, updated or deleted. 10397 ** This may appear to have some counter-intuitive effects if a single row 10398 ** is written to more than once during a session. For example, if a row 10399 ** is inserted while a session object is enabled, then later deleted while 10400 ** the same session object is disabled, no INSERT record will appear in the 10401 ** changeset, even though the delete took place while the session was disabled. 10402 ** Or, if one field of a row is updated while a session is disabled, and 10403 ** another field of the same row is updated while the session is enabled, the 10404 ** resulting changeset will contain an UPDATE change that updates both fields. 10405 */ 10406 SQLITE_API int sqlite3session_changeset( 10407 sqlite3_session *pSession, /* Session object */ 10408 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 10409 void **ppChangeset /* OUT: Buffer containing changeset */ 10410 ); 10411 10412 /* 10413 ** CAPI3REF: Return An Upper-limit For The Size Of The Changeset 10414 ** METHOD: sqlite3_session 10415 ** 10416 ** By default, this function always returns 0. For it to return 10417 ** a useful result, the sqlite3_session object must have been configured 10418 ** to enable this API using sqlite3session_object_config() with the 10419 ** SQLITE_SESSION_OBJCONFIG_SIZE verb. 10420 ** 10421 ** When enabled, this function returns an upper limit, in bytes, for the size 10422 ** of the changeset that might be produced if sqlite3session_changeset() were 10423 ** called. The final changeset size might be equal to or smaller than the 10424 ** size in bytes returned by this function. 10425 */ 10426 SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession); 10427 10428 /* 10429 ** CAPI3REF: Load The Difference Between Tables Into A Session 10430 ** METHOD: sqlite3_session 10431 ** 10432 ** If it is not already attached to the session object passed as the first 10433 ** argument, this function attaches table zTbl in the same manner as the 10434 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 10435 ** does not have a primary key, this function is a no-op (but does not return 10436 ** an error). 10437 ** 10438 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 10439 ** attached to the same database handle as the session object that contains 10440 ** a table compatible with the table attached to the session by this function. 10441 ** A table is considered compatible if it: 10442 ** 10443 ** <ul> 10444 ** <li> Has the same name, 10445 ** <li> Has the same set of columns declared in the same order, and 10446 ** <li> Has the same PRIMARY KEY definition. 10447 ** </ul> 10448 ** 10449 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 10450 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 10451 ** but no changes are added to the session object. As with other session 10452 ** APIs, tables without PRIMARY KEYs are simply ignored. 10453 ** 10454 ** This function adds a set of changes to the session object that could be 10455 ** used to update the table in database zFrom (call this the "from-table") 10456 ** so that its content is the same as the table attached to the session 10457 ** object (call this the "to-table"). Specifically: 10458 ** 10459 ** <ul> 10460 ** <li> For each row (primary key) that exists in the to-table but not in 10461 ** the from-table, an INSERT record is added to the session object. 10462 ** 10463 ** <li> For each row (primary key) that exists in the to-table but not in 10464 ** the from-table, a DELETE record is added to the session object. 10465 ** 10466 ** <li> For each row (primary key) that exists in both tables, but features 10467 ** different non-PK values in each, an UPDATE record is added to the 10468 ** session. 10469 ** </ul> 10470 ** 10471 ** To clarify, if this function is called and then a changeset constructed 10472 ** using [sqlite3session_changeset()], then after applying that changeset to 10473 ** database zFrom the contents of the two compatible tables would be 10474 ** identical. 10475 ** 10476 ** It an error if database zFrom does not exist or does not contain the 10477 ** required compatible table. 10478 ** 10479 ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite 10480 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 10481 ** may be set to point to a buffer containing an English language error 10482 ** message. It is the responsibility of the caller to free this buffer using 10483 ** sqlite3_free(). 10484 */ 10485 SQLITE_API int sqlite3session_diff( 10486 sqlite3_session *pSession, 10487 const char *zFromDb, 10488 const char *zTbl, 10489 char **pzErrMsg 10490 ); 10491 10492 10493 /* 10494 ** CAPI3REF: Generate A Patchset From A Session Object 10495 ** METHOD: sqlite3_session 10496 ** 10497 ** The differences between a patchset and a changeset are that: 10498 ** 10499 ** <ul> 10500 ** <li> DELETE records consist of the primary key fields only. The 10501 ** original values of other fields are omitted. 10502 ** <li> The original values of any modified fields are omitted from 10503 ** UPDATE records. 10504 ** </ul> 10505 ** 10506 ** A patchset blob may be used with up to date versions of all 10507 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 10508 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 10509 ** attempting to use a patchset blob with old versions of the 10510 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 10511 ** 10512 ** Because the non-primary key "old.*" fields are omitted, no 10513 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 10514 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 10515 ** in the same way as for changesets. 10516 ** 10517 ** Changes within a patchset are ordered in the same way as for changesets 10518 ** generated by the sqlite3session_changeset() function (i.e. all changes for 10519 ** a single table are grouped together, tables appear in the order in which 10520 ** they were attached to the session object). 10521 */ 10522 SQLITE_API int sqlite3session_patchset( 10523 sqlite3_session *pSession, /* Session object */ 10524 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 10525 void **ppPatchset /* OUT: Buffer containing patchset */ 10526 ); 10527 10528 /* 10529 ** CAPI3REF: Test if a changeset has recorded any changes. 10530 ** 10531 ** Return non-zero if no changes to attached tables have been recorded by 10532 ** the session object passed as the first argument. Otherwise, if one or 10533 ** more changes have been recorded, return zero. 10534 ** 10535 ** Even if this function returns zero, it is possible that calling 10536 ** [sqlite3session_changeset()] on the session handle may still return a 10537 ** changeset that contains no changes. This can happen when a row in 10538 ** an attached table is modified and then later on the original values 10539 ** are restored. However, if this function returns non-zero, then it is 10540 ** guaranteed that a call to sqlite3session_changeset() will return a 10541 ** changeset containing zero changes. 10542 */ 10543 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 10544 10545 /* 10546 ** CAPI3REF: Query for the amount of heap memory used by a session object. 10547 ** 10548 ** This API returns the total amount of heap memory in bytes currently 10549 ** used by the session object passed as the only argument. 10550 */ 10551 SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession); 10552 10553 /* 10554 ** CAPI3REF: Create An Iterator To Traverse A Changeset 10555 ** CONSTRUCTOR: sqlite3_changeset_iter 10556 ** 10557 ** Create an iterator used to iterate through the contents of a changeset. 10558 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 10559 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 10560 ** SQLite error code is returned. 10561 ** 10562 ** The following functions can be used to advance and query a changeset 10563 ** iterator created by this function: 10564 ** 10565 ** <ul> 10566 ** <li> [sqlite3changeset_next()] 10567 ** <li> [sqlite3changeset_op()] 10568 ** <li> [sqlite3changeset_new()] 10569 ** <li> [sqlite3changeset_old()] 10570 ** </ul> 10571 ** 10572 ** It is the responsibility of the caller to eventually destroy the iterator 10573 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 10574 ** changeset (pChangeset) must remain valid until after the iterator is 10575 ** destroyed. 10576 ** 10577 ** Assuming the changeset blob was created by one of the 10578 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 10579 ** [sqlite3changeset_invert()] functions, all changes within the changeset 10580 ** that apply to a single table are grouped together. This means that when 10581 ** an application iterates through a changeset using an iterator created by 10582 ** this function, all changes that relate to a single table are visited 10583 ** consecutively. There is no chance that the iterator will visit a change 10584 ** the applies to table X, then one for table Y, and then later on visit 10585 ** another change for table X. 10586 ** 10587 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent 10588 ** may be modified by passing a combination of 10589 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter. 10590 ** 10591 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b> 10592 ** and therefore subject to change. 10593 */ 10594 SQLITE_API int sqlite3changeset_start( 10595 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 10596 int nChangeset, /* Size of changeset blob in bytes */ 10597 void *pChangeset /* Pointer to blob containing changeset */ 10598 ); 10599 SQLITE_API int sqlite3changeset_start_v2( 10600 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 10601 int nChangeset, /* Size of changeset blob in bytes */ 10602 void *pChangeset, /* Pointer to blob containing changeset */ 10603 int flags /* SESSION_CHANGESETSTART_* flags */ 10604 ); 10605 10606 /* 10607 ** CAPI3REF: Flags for sqlite3changeset_start_v2 10608 ** 10609 ** The following flags may passed via the 4th parameter to 10610 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]: 10611 ** 10612 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 10613 ** Invert the changeset while iterating through it. This is equivalent to 10614 ** inverting a changeset using sqlite3changeset_invert() before applying it. 10615 ** It is an error to specify this flag with a patchset. 10616 */ 10617 #define SQLITE_CHANGESETSTART_INVERT 0x0002 10618 10619 10620 /* 10621 ** CAPI3REF: Advance A Changeset Iterator 10622 ** METHOD: sqlite3_changeset_iter 10623 ** 10624 ** This function may only be used with iterators created by the function 10625 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 10626 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 10627 ** is returned and the call has no effect. 10628 ** 10629 ** Immediately after an iterator is created by sqlite3changeset_start(), it 10630 ** does not point to any change in the changeset. Assuming the changeset 10631 ** is not empty, the first call to this function advances the iterator to 10632 ** point to the first change in the changeset. Each subsequent call advances 10633 ** the iterator to point to the next change in the changeset (if any). If 10634 ** no error occurs and the iterator points to a valid change after a call 10635 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 10636 ** Otherwise, if all changes in the changeset have already been visited, 10637 ** SQLITE_DONE is returned. 10638 ** 10639 ** If an error occurs, an SQLite error code is returned. Possible error 10640 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 10641 ** SQLITE_NOMEM. 10642 */ 10643 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 10644 10645 /* 10646 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 10647 ** METHOD: sqlite3_changeset_iter 10648 ** 10649 ** The pIter argument passed to this function may either be an iterator 10650 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10651 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10652 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 10653 ** is not the case, this function returns [SQLITE_MISUSE]. 10654 ** 10655 ** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three 10656 ** outputs are set through these pointers: 10657 ** 10658 ** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], 10659 ** depending on the type of change that the iterator currently points to; 10660 ** 10661 ** *pnCol is set to the number of columns in the table affected by the change; and 10662 ** 10663 ** *pzTab is set to point to a nul-terminated utf-8 encoded string containing 10664 ** the name of the table affected by the current change. The buffer remains 10665 ** valid until either sqlite3changeset_next() is called on the iterator 10666 ** or until the conflict-handler function returns. 10667 ** 10668 ** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change 10669 ** is an indirect change, or false (0) otherwise. See the documentation for 10670 ** [sqlite3session_indirect()] for a description of direct and indirect 10671 ** changes. 10672 ** 10673 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 10674 ** SQLite error code is returned. The values of the output variables may not 10675 ** be trusted in this case. 10676 */ 10677 SQLITE_API int sqlite3changeset_op( 10678 sqlite3_changeset_iter *pIter, /* Iterator object */ 10679 const char **pzTab, /* OUT: Pointer to table name */ 10680 int *pnCol, /* OUT: Number of columns in table */ 10681 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 10682 int *pbIndirect /* OUT: True for an 'indirect' change */ 10683 ); 10684 10685 /* 10686 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 10687 ** METHOD: sqlite3_changeset_iter 10688 ** 10689 ** For each modified table, a changeset includes the following: 10690 ** 10691 ** <ul> 10692 ** <li> The number of columns in the table, and 10693 ** <li> Which of those columns make up the tables PRIMARY KEY. 10694 ** </ul> 10695 ** 10696 ** This function is used to find which columns comprise the PRIMARY KEY of 10697 ** the table modified by the change that iterator pIter currently points to. 10698 ** If successful, *pabPK is set to point to an array of nCol entries, where 10699 ** nCol is the number of columns in the table. Elements of *pabPK are set to 10700 ** 0x01 if the corresponding column is part of the tables primary key, or 10701 ** 0x00 if it is not. 10702 ** 10703 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 10704 ** in the table. 10705 ** 10706 ** If this function is called when the iterator does not point to a valid 10707 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 10708 ** SQLITE_OK is returned and the output variables populated as described 10709 ** above. 10710 */ 10711 SQLITE_API int sqlite3changeset_pk( 10712 sqlite3_changeset_iter *pIter, /* Iterator object */ 10713 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 10714 int *pnCol /* OUT: Number of entries in output array */ 10715 ); 10716 10717 /* 10718 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 10719 ** METHOD: sqlite3_changeset_iter 10720 ** 10721 ** The pIter argument passed to this function may either be an iterator 10722 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10723 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10724 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10725 ** Furthermore, it may only be called if the type of change that the iterator 10726 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 10727 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10728 ** 10729 ** Argument iVal must be greater than or equal to 0, and less than the number 10730 ** of columns in the table affected by the current change. Otherwise, 10731 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10732 ** 10733 ** If successful, this function sets *ppValue to point to a protected 10734 ** sqlite3_value object containing the iVal'th value from the vector of 10735 ** original row values stored as part of the UPDATE or DELETE change and 10736 ** returns SQLITE_OK. The name of the function comes from the fact that this 10737 ** is similar to the "old.*" columns available to update or delete triggers. 10738 ** 10739 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10740 ** is returned and *ppValue is set to NULL. 10741 */ 10742 SQLITE_API int sqlite3changeset_old( 10743 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10744 int iVal, /* Column number */ 10745 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 10746 ); 10747 10748 /* 10749 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 10750 ** METHOD: sqlite3_changeset_iter 10751 ** 10752 ** The pIter argument passed to this function may either be an iterator 10753 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10754 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10755 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10756 ** Furthermore, it may only be called if the type of change that the iterator 10757 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 10758 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10759 ** 10760 ** Argument iVal must be greater than or equal to 0, and less than the number 10761 ** of columns in the table affected by the current change. Otherwise, 10762 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10763 ** 10764 ** If successful, this function sets *ppValue to point to a protected 10765 ** sqlite3_value object containing the iVal'th value from the vector of 10766 ** new row values stored as part of the UPDATE or INSERT change and 10767 ** returns SQLITE_OK. If the change is an UPDATE and does not include 10768 ** a new value for the requested column, *ppValue is set to NULL and 10769 ** SQLITE_OK returned. The name of the function comes from the fact that 10770 ** this is similar to the "new.*" columns available to update or delete 10771 ** triggers. 10772 ** 10773 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10774 ** is returned and *ppValue is set to NULL. 10775 */ 10776 SQLITE_API int sqlite3changeset_new( 10777 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10778 int iVal, /* Column number */ 10779 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 10780 ); 10781 10782 /* 10783 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 10784 ** METHOD: sqlite3_changeset_iter 10785 ** 10786 ** This function should only be used with iterator objects passed to a 10787 ** conflict-handler callback by [sqlite3changeset_apply()] with either 10788 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 10789 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 10790 ** is set to NULL. 10791 ** 10792 ** Argument iVal must be greater than or equal to 0, and less than the number 10793 ** of columns in the table affected by the current change. Otherwise, 10794 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10795 ** 10796 ** If successful, this function sets *ppValue to point to a protected 10797 ** sqlite3_value object containing the iVal'th value from the 10798 ** "conflicting row" associated with the current conflict-handler callback 10799 ** and returns SQLITE_OK. 10800 ** 10801 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10802 ** is returned and *ppValue is set to NULL. 10803 */ 10804 SQLITE_API int sqlite3changeset_conflict( 10805 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10806 int iVal, /* Column number */ 10807 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 10808 ); 10809 10810 /* 10811 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 10812 ** METHOD: sqlite3_changeset_iter 10813 ** 10814 ** This function may only be called with an iterator passed to an 10815 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 10816 ** it sets the output variable to the total number of known foreign key 10817 ** violations in the destination database and returns SQLITE_OK. 10818 ** 10819 ** In all other cases this function returns SQLITE_MISUSE. 10820 */ 10821 SQLITE_API int sqlite3changeset_fk_conflicts( 10822 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10823 int *pnOut /* OUT: Number of FK violations */ 10824 ); 10825 10826 10827 /* 10828 ** CAPI3REF: Finalize A Changeset Iterator 10829 ** METHOD: sqlite3_changeset_iter 10830 ** 10831 ** This function is used to finalize an iterator allocated with 10832 ** [sqlite3changeset_start()]. 10833 ** 10834 ** This function should only be called on iterators created using the 10835 ** [sqlite3changeset_start()] function. If an application calls this 10836 ** function with an iterator passed to a conflict-handler by 10837 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 10838 ** call has no effect. 10839 ** 10840 ** If an error was encountered within a call to an sqlite3changeset_xxx() 10841 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 10842 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 10843 ** to that error is returned by this function. Otherwise, SQLITE_OK is 10844 ** returned. This is to allow the following pattern (pseudo-code): 10845 ** 10846 ** <pre> 10847 ** sqlite3changeset_start(); 10848 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 10849 ** // Do something with change. 10850 ** } 10851 ** rc = sqlite3changeset_finalize(); 10852 ** if( rc!=SQLITE_OK ){ 10853 ** // An error has occurred 10854 ** } 10855 ** </pre> 10856 */ 10857 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 10858 10859 /* 10860 ** CAPI3REF: Invert A Changeset 10861 ** 10862 ** This function is used to "invert" a changeset object. Applying an inverted 10863 ** changeset to a database reverses the effects of applying the uninverted 10864 ** changeset. Specifically: 10865 ** 10866 ** <ul> 10867 ** <li> Each DELETE change is changed to an INSERT, and 10868 ** <li> Each INSERT change is changed to a DELETE, and 10869 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 10870 ** </ul> 10871 ** 10872 ** This function does not change the order in which changes appear within 10873 ** the changeset. It merely reverses the sense of each individual change. 10874 ** 10875 ** If successful, a pointer to a buffer containing the inverted changeset 10876 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 10877 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 10878 ** zeroed and an SQLite error code returned. 10879 ** 10880 ** It is the responsibility of the caller to eventually call sqlite3_free() 10881 ** on the *ppOut pointer to free the buffer allocation following a successful 10882 ** call to this function. 10883 ** 10884 ** WARNING/TODO: This function currently assumes that the input is a valid 10885 ** changeset. If it is not, the results are undefined. 10886 */ 10887 SQLITE_API int sqlite3changeset_invert( 10888 int nIn, const void *pIn, /* Input changeset */ 10889 int *pnOut, void **ppOut /* OUT: Inverse of input */ 10890 ); 10891 10892 /* 10893 ** CAPI3REF: Concatenate Two Changeset Objects 10894 ** 10895 ** This function is used to concatenate two changesets, A and B, into a 10896 ** single changeset. The result is a changeset equivalent to applying 10897 ** changeset A followed by changeset B. 10898 ** 10899 ** This function combines the two input changesets using an 10900 ** sqlite3_changegroup object. Calling it produces similar results as the 10901 ** following code fragment: 10902 ** 10903 ** <pre> 10904 ** sqlite3_changegroup *pGrp; 10905 ** rc = sqlite3_changegroup_new(&pGrp); 10906 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 10907 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 10908 ** if( rc==SQLITE_OK ){ 10909 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 10910 ** }else{ 10911 ** *ppOut = 0; 10912 ** *pnOut = 0; 10913 ** } 10914 ** </pre> 10915 ** 10916 ** Refer to the sqlite3_changegroup documentation below for details. 10917 */ 10918 SQLITE_API int sqlite3changeset_concat( 10919 int nA, /* Number of bytes in buffer pA */ 10920 void *pA, /* Pointer to buffer containing changeset A */ 10921 int nB, /* Number of bytes in buffer pB */ 10922 void *pB, /* Pointer to buffer containing changeset B */ 10923 int *pnOut, /* OUT: Number of bytes in output changeset */ 10924 void **ppOut /* OUT: Buffer containing output changeset */ 10925 ); 10926 10927 10928 /* 10929 ** CAPI3REF: Changegroup Handle 10930 ** 10931 ** A changegroup is an object used to combine two or more 10932 ** [changesets] or [patchsets] 10933 */ 10934 typedef struct sqlite3_changegroup sqlite3_changegroup; 10935 10936 /* 10937 ** CAPI3REF: Create A New Changegroup Object 10938 ** CONSTRUCTOR: sqlite3_changegroup 10939 ** 10940 ** An sqlite3_changegroup object is used to combine two or more changesets 10941 ** (or patchsets) into a single changeset (or patchset). A single changegroup 10942 ** object may combine changesets or patchsets, but not both. The output is 10943 ** always in the same format as the input. 10944 ** 10945 ** If successful, this function returns SQLITE_OK and populates (*pp) with 10946 ** a pointer to a new sqlite3_changegroup object before returning. The caller 10947 ** should eventually free the returned object using a call to 10948 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 10949 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 10950 ** 10951 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 10952 ** 10953 ** <ul> 10954 ** <li> It is created using a call to sqlite3changegroup_new(). 10955 ** 10956 ** <li> Zero or more changesets (or patchsets) are added to the object 10957 ** by calling sqlite3changegroup_add(). 10958 ** 10959 ** <li> The result of combining all input changesets together is obtained 10960 ** by the application via a call to sqlite3changegroup_output(). 10961 ** 10962 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 10963 ** </ul> 10964 ** 10965 ** Any number of calls to add() and output() may be made between the calls to 10966 ** new() and delete(), and in any order. 10967 ** 10968 ** As well as the regular sqlite3changegroup_add() and 10969 ** sqlite3changegroup_output() functions, also available are the streaming 10970 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 10971 */ 10972 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 10973 10974 /* 10975 ** CAPI3REF: Add A Changeset To A Changegroup 10976 ** METHOD: sqlite3_changegroup 10977 ** 10978 ** Add all changes within the changeset (or patchset) in buffer pData (size 10979 ** nData bytes) to the changegroup. 10980 ** 10981 ** If the buffer contains a patchset, then all prior calls to this function 10982 ** on the same changegroup object must also have specified patchsets. Or, if 10983 ** the buffer contains a changeset, so must have the earlier calls to this 10984 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 10985 ** to the changegroup. 10986 ** 10987 ** Rows within the changeset and changegroup are identified by the values in 10988 ** their PRIMARY KEY columns. A change in the changeset is considered to 10989 ** apply to the same row as a change already present in the changegroup if 10990 ** the two rows have the same primary key. 10991 ** 10992 ** Changes to rows that do not already appear in the changegroup are 10993 ** simply copied into it. Or, if both the new changeset and the changegroup 10994 ** contain changes that apply to a single row, the final contents of the 10995 ** changegroup depends on the type of each change, as follows: 10996 ** 10997 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 10998 ** <tr><th style="white-space:pre">Existing Change </th> 10999 ** <th style="white-space:pre">New Change </th> 11000 ** <th>Output Change 11001 ** <tr><td>INSERT <td>INSERT <td> 11002 ** The new change is ignored. This case does not occur if the new 11003 ** changeset was recorded immediately after the changesets already 11004 ** added to the changegroup. 11005 ** <tr><td>INSERT <td>UPDATE <td> 11006 ** The INSERT change remains in the changegroup. The values in the 11007 ** INSERT change are modified as if the row was inserted by the 11008 ** existing change and then updated according to the new change. 11009 ** <tr><td>INSERT <td>DELETE <td> 11010 ** The existing INSERT is removed from the changegroup. The DELETE is 11011 ** not added. 11012 ** <tr><td>UPDATE <td>INSERT <td> 11013 ** The new change is ignored. This case does not occur if the new 11014 ** changeset was recorded immediately after the changesets already 11015 ** added to the changegroup. 11016 ** <tr><td>UPDATE <td>UPDATE <td> 11017 ** The existing UPDATE remains within the changegroup. It is amended 11018 ** so that the accompanying values are as if the row was updated once 11019 ** by the existing change and then again by the new change. 11020 ** <tr><td>UPDATE <td>DELETE <td> 11021 ** The existing UPDATE is replaced by the new DELETE within the 11022 ** changegroup. 11023 ** <tr><td>DELETE <td>INSERT <td> 11024 ** If one or more of the column values in the row inserted by the 11025 ** new change differ from those in the row deleted by the existing 11026 ** change, the existing DELETE is replaced by an UPDATE within the 11027 ** changegroup. Otherwise, if the inserted row is exactly the same 11028 ** as the deleted row, the existing DELETE is simply discarded. 11029 ** <tr><td>DELETE <td>UPDATE <td> 11030 ** The new change is ignored. This case does not occur if the new 11031 ** changeset was recorded immediately after the changesets already 11032 ** added to the changegroup. 11033 ** <tr><td>DELETE <td>DELETE <td> 11034 ** The new change is ignored. This case does not occur if the new 11035 ** changeset was recorded immediately after the changesets already 11036 ** added to the changegroup. 11037 ** </table> 11038 ** 11039 ** If the new changeset contains changes to a table that is already present 11040 ** in the changegroup, then the number of columns and the position of the 11041 ** primary key columns for the table must be consistent. If this is not the 11042 ** case, this function fails with SQLITE_SCHEMA. If the input changeset 11043 ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 11044 ** returned. Or, if an out-of-memory condition occurs during processing, this 11045 ** function returns SQLITE_NOMEM. In all cases, if an error occurs the state 11046 ** of the final contents of the changegroup is undefined. 11047 ** 11048 ** If no error occurs, SQLITE_OK is returned. 11049 */ 11050 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 11051 11052 /* 11053 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 11054 ** METHOD: sqlite3_changegroup 11055 ** 11056 ** Obtain a buffer containing a changeset (or patchset) representing the 11057 ** current contents of the changegroup. If the inputs to the changegroup 11058 ** were themselves changesets, the output is a changeset. Or, if the 11059 ** inputs were patchsets, the output is also a patchset. 11060 ** 11061 ** As with the output of the sqlite3session_changeset() and 11062 ** sqlite3session_patchset() functions, all changes related to a single 11063 ** table are grouped together in the output of this function. Tables appear 11064 ** in the same order as for the very first changeset added to the changegroup. 11065 ** If the second or subsequent changesets added to the changegroup contain 11066 ** changes for tables that do not appear in the first changeset, they are 11067 ** appended onto the end of the output changeset, again in the order in 11068 ** which they are first encountered. 11069 ** 11070 ** If an error occurs, an SQLite error code is returned and the output 11071 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 11072 ** is returned and the output variables are set to the size of and a 11073 ** pointer to the output buffer, respectively. In this case it is the 11074 ** responsibility of the caller to eventually free the buffer using a 11075 ** call to sqlite3_free(). 11076 */ 11077 SQLITE_API int sqlite3changegroup_output( 11078 sqlite3_changegroup*, 11079 int *pnData, /* OUT: Size of output buffer in bytes */ 11080 void **ppData /* OUT: Pointer to output buffer */ 11081 ); 11082 11083 /* 11084 ** CAPI3REF: Delete A Changegroup Object 11085 ** DESTRUCTOR: sqlite3_changegroup 11086 */ 11087 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 11088 11089 /* 11090 ** CAPI3REF: Apply A Changeset To A Database 11091 ** 11092 ** Apply a changeset or patchset to a database. These functions attempt to 11093 ** update the "main" database attached to handle db with the changes found in 11094 ** the changeset passed via the second and third arguments. 11095 ** 11096 ** The fourth argument (xFilter) passed to these functions is the "filter 11097 ** callback". If it is not NULL, then for each table affected by at least one 11098 ** change in the changeset, the filter callback is invoked with 11099 ** the table name as the second argument, and a copy of the context pointer 11100 ** passed as the sixth argument as the first. If the "filter callback" 11101 ** returns zero, then no attempt is made to apply any changes to the table. 11102 ** Otherwise, if the return value is non-zero or the xFilter argument to 11103 ** is NULL, all changes related to the table are attempted. 11104 ** 11105 ** For each table that is not excluded by the filter callback, this function 11106 ** tests that the target database contains a compatible table. A table is 11107 ** considered compatible if all of the following are true: 11108 ** 11109 ** <ul> 11110 ** <li> The table has the same name as the name recorded in the 11111 ** changeset, and 11112 ** <li> The table has at least as many columns as recorded in the 11113 ** changeset, and 11114 ** <li> The table has primary key columns in the same position as 11115 ** recorded in the changeset. 11116 ** </ul> 11117 ** 11118 ** If there is no compatible table, it is not an error, but none of the 11119 ** changes associated with the table are applied. A warning message is issued 11120 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 11121 ** one such warning is issued for each table in the changeset. 11122 ** 11123 ** For each change for which there is a compatible table, an attempt is made 11124 ** to modify the table contents according to the UPDATE, INSERT or DELETE 11125 ** change. If a change cannot be applied cleanly, the conflict handler 11126 ** function passed as the fifth argument to sqlite3changeset_apply() may be 11127 ** invoked. A description of exactly when the conflict handler is invoked for 11128 ** each type of change is below. 11129 ** 11130 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 11131 ** of passing anything other than a valid function pointer as the xConflict 11132 ** argument are undefined. 11133 ** 11134 ** Each time the conflict handler function is invoked, it must return one 11135 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 11136 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 11137 ** if the second argument passed to the conflict handler is either 11138 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 11139 ** returns an illegal value, any changes already made are rolled back and 11140 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 11141 ** actions are taken by sqlite3changeset_apply() depending on the value 11142 ** returned by each invocation of the conflict-handler function. Refer to 11143 ** the documentation for the three 11144 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 11145 ** 11146 ** <dl> 11147 ** <dt>DELETE Changes<dd> 11148 ** For each DELETE change, the function checks if the target database 11149 ** contains a row with the same primary key value (or values) as the 11150 ** original row values stored in the changeset. If it does, and the values 11151 ** stored in all non-primary key columns also match the values stored in 11152 ** the changeset the row is deleted from the target database. 11153 ** 11154 ** If a row with matching primary key values is found, but one or more of 11155 ** the non-primary key fields contains a value different from the original 11156 ** row value stored in the changeset, the conflict-handler function is 11157 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 11158 ** database table has more columns than are recorded in the changeset, 11159 ** only the values of those non-primary key fields are compared against 11160 ** the current database contents - any trailing database table columns 11161 ** are ignored. 11162 ** 11163 ** If no row with matching primary key values is found in the database, 11164 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 11165 ** passed as the second argument. 11166 ** 11167 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 11168 ** (which can only happen if a foreign key constraint is violated), the 11169 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 11170 ** passed as the second argument. This includes the case where the DELETE 11171 ** operation is attempted because an earlier call to the conflict handler 11172 ** function returned [SQLITE_CHANGESET_REPLACE]. 11173 ** 11174 ** <dt>INSERT Changes<dd> 11175 ** For each INSERT change, an attempt is made to insert the new row into 11176 ** the database. If the changeset row contains fewer fields than the 11177 ** database table, the trailing fields are populated with their default 11178 ** values. 11179 ** 11180 ** If the attempt to insert the row fails because the database already 11181 ** contains a row with the same primary key values, the conflict handler 11182 ** function is invoked with the second argument set to 11183 ** [SQLITE_CHANGESET_CONFLICT]. 11184 ** 11185 ** If the attempt to insert the row fails because of some other constraint 11186 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 11187 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 11188 ** This includes the case where the INSERT operation is re-attempted because 11189 ** an earlier call to the conflict handler function returned 11190 ** [SQLITE_CHANGESET_REPLACE]. 11191 ** 11192 ** <dt>UPDATE Changes<dd> 11193 ** For each UPDATE change, the function checks if the target database 11194 ** contains a row with the same primary key value (or values) as the 11195 ** original row values stored in the changeset. If it does, and the values 11196 ** stored in all modified non-primary key columns also match the values 11197 ** stored in the changeset the row is updated within the target database. 11198 ** 11199 ** If a row with matching primary key values is found, but one or more of 11200 ** the modified non-primary key fields contains a value different from an 11201 ** original row value stored in the changeset, the conflict-handler function 11202 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 11203 ** UPDATE changes only contain values for non-primary key fields that are 11204 ** to be modified, only those fields need to match the original values to 11205 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 11206 ** 11207 ** If no row with matching primary key values is found in the database, 11208 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 11209 ** passed as the second argument. 11210 ** 11211 ** If the UPDATE operation is attempted, but SQLite returns 11212 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 11213 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 11214 ** This includes the case where the UPDATE operation is attempted after 11215 ** an earlier call to the conflict handler function returned 11216 ** [SQLITE_CHANGESET_REPLACE]. 11217 ** </dl> 11218 ** 11219 ** It is safe to execute SQL statements, including those that write to the 11220 ** table that the callback related to, from within the xConflict callback. 11221 ** This can be used to further customize the application's conflict 11222 ** resolution strategy. 11223 ** 11224 ** All changes made by these functions are enclosed in a savepoint transaction. 11225 ** If any other error (aside from a constraint failure when attempting to 11226 ** write to the target database) occurs, then the savepoint transaction is 11227 ** rolled back, restoring the target database to its original state, and an 11228 ** SQLite error code returned. 11229 ** 11230 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 11231 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 11232 ** may set (*ppRebase) to point to a "rebase" that may be used with the 11233 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 11234 ** is set to the size of the buffer in bytes. It is the responsibility of the 11235 ** caller to eventually free any such buffer using sqlite3_free(). The buffer 11236 ** is only allocated and populated if one or more conflicts were encountered 11237 ** while applying the patchset. See comments surrounding the sqlite3_rebaser 11238 ** APIs for further details. 11239 ** 11240 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 11241 ** may be modified by passing a combination of 11242 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 11243 ** 11244 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 11245 ** and therefore subject to change. 11246 */ 11247 SQLITE_API int sqlite3changeset_apply( 11248 sqlite3 *db, /* Apply change to "main" db of this handle */ 11249 int nChangeset, /* Size of changeset in bytes */ 11250 void *pChangeset, /* Changeset blob */ 11251 int(*xFilter)( 11252 void *pCtx, /* Copy of sixth arg to _apply() */ 11253 const char *zTab /* Table name */ 11254 ), 11255 int(*xConflict)( 11256 void *pCtx, /* Copy of sixth arg to _apply() */ 11257 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11258 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11259 ), 11260 void *pCtx /* First argument passed to xConflict */ 11261 ); 11262 SQLITE_API int sqlite3changeset_apply_v2( 11263 sqlite3 *db, /* Apply change to "main" db of this handle */ 11264 int nChangeset, /* Size of changeset in bytes */ 11265 void *pChangeset, /* Changeset blob */ 11266 int(*xFilter)( 11267 void *pCtx, /* Copy of sixth arg to _apply() */ 11268 const char *zTab /* Table name */ 11269 ), 11270 int(*xConflict)( 11271 void *pCtx, /* Copy of sixth arg to _apply() */ 11272 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11273 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11274 ), 11275 void *pCtx, /* First argument passed to xConflict */ 11276 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 11277 int flags /* SESSION_CHANGESETAPPLY_* flags */ 11278 ); 11279 11280 /* 11281 ** CAPI3REF: Flags for sqlite3changeset_apply_v2 11282 ** 11283 ** The following flags may passed via the 9th parameter to 11284 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 11285 ** 11286 ** <dl> 11287 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 11288 ** Usually, the sessions module encloses all operations performed by 11289 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 11290 ** SAVEPOINT is committed if the changeset or patchset is successfully 11291 ** applied, or rolled back if an error occurs. Specifying this flag 11292 ** causes the sessions module to omit this savepoint. In this case, if the 11293 ** caller has an open transaction or savepoint when apply_v2() is called, 11294 ** it may revert the partially applied changeset by rolling it back. 11295 ** 11296 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 11297 ** Invert the changeset before applying it. This is equivalent to inverting 11298 ** a changeset using sqlite3changeset_invert() before applying it. It is 11299 ** an error to specify this flag with a patchset. 11300 */ 11301 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 11302 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002 11303 11304 /* 11305 ** CAPI3REF: Constants Passed To The Conflict Handler 11306 ** 11307 ** Values that may be passed as the second argument to a conflict-handler. 11308 ** 11309 ** <dl> 11310 ** <dt>SQLITE_CHANGESET_DATA<dd> 11311 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 11312 ** when processing a DELETE or UPDATE change if a row with the required 11313 ** PRIMARY KEY fields is present in the database, but one or more other 11314 ** (non primary-key) fields modified by the update do not contain the 11315 ** expected "before" values. 11316 ** 11317 ** The conflicting row, in this case, is the database row with the matching 11318 ** primary key. 11319 ** 11320 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 11321 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 11322 ** argument when processing a DELETE or UPDATE change if a row with the 11323 ** required PRIMARY KEY fields is not present in the database. 11324 ** 11325 ** There is no conflicting row in this case. The results of invoking the 11326 ** sqlite3changeset_conflict() API are undefined. 11327 ** 11328 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 11329 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 11330 ** handler while processing an INSERT change if the operation would result 11331 ** in duplicate primary key values. 11332 ** 11333 ** The conflicting row in this case is the database row with the matching 11334 ** primary key. 11335 ** 11336 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 11337 ** If foreign key handling is enabled, and applying a changeset leaves the 11338 ** database in a state containing foreign key violations, the conflict 11339 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 11340 ** exactly once before the changeset is committed. If the conflict handler 11341 ** returns CHANGESET_OMIT, the changes, including those that caused the 11342 ** foreign key constraint violation, are committed. Or, if it returns 11343 ** CHANGESET_ABORT, the changeset is rolled back. 11344 ** 11345 ** No current or conflicting row information is provided. The only function 11346 ** it is possible to call on the supplied sqlite3_changeset_iter handle 11347 ** is sqlite3changeset_fk_conflicts(). 11348 ** 11349 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 11350 ** If any other constraint violation occurs while applying a change (i.e. 11351 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 11352 ** invoked with CHANGESET_CONSTRAINT as the second argument. 11353 ** 11354 ** There is no conflicting row in this case. The results of invoking the 11355 ** sqlite3changeset_conflict() API are undefined. 11356 ** 11357 ** </dl> 11358 */ 11359 #define SQLITE_CHANGESET_DATA 1 11360 #define SQLITE_CHANGESET_NOTFOUND 2 11361 #define SQLITE_CHANGESET_CONFLICT 3 11362 #define SQLITE_CHANGESET_CONSTRAINT 4 11363 #define SQLITE_CHANGESET_FOREIGN_KEY 5 11364 11365 /* 11366 ** CAPI3REF: Constants Returned By The Conflict Handler 11367 ** 11368 ** A conflict handler callback must return one of the following three values. 11369 ** 11370 ** <dl> 11371 ** <dt>SQLITE_CHANGESET_OMIT<dd> 11372 ** If a conflict handler returns this value no special action is taken. The 11373 ** change that caused the conflict is not applied. The session module 11374 ** continues to the next change in the changeset. 11375 ** 11376 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 11377 ** This value may only be returned if the second argument to the conflict 11378 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 11379 ** is not the case, any changes applied so far are rolled back and the 11380 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 11381 ** 11382 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 11383 ** handler, then the conflicting row is either updated or deleted, depending 11384 ** on the type of change. 11385 ** 11386 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 11387 ** handler, then the conflicting row is removed from the database and a 11388 ** second attempt to apply the change is made. If this second attempt fails, 11389 ** the original row is restored to the database before continuing. 11390 ** 11391 ** <dt>SQLITE_CHANGESET_ABORT<dd> 11392 ** If this value is returned, any changes applied so far are rolled back 11393 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 11394 ** </dl> 11395 */ 11396 #define SQLITE_CHANGESET_OMIT 0 11397 #define SQLITE_CHANGESET_REPLACE 1 11398 #define SQLITE_CHANGESET_ABORT 2 11399 11400 /* 11401 ** CAPI3REF: Rebasing changesets 11402 ** EXPERIMENTAL 11403 ** 11404 ** Suppose there is a site hosting a database in state S0. And that 11405 ** modifications are made that move that database to state S1 and a 11406 ** changeset recorded (the "local" changeset). Then, a changeset based 11407 ** on S0 is received from another site (the "remote" changeset) and 11408 ** applied to the database. The database is then in state 11409 ** (S1+"remote"), where the exact state depends on any conflict 11410 ** resolution decisions (OMIT or REPLACE) made while applying "remote". 11411 ** Rebasing a changeset is to update it to take those conflict 11412 ** resolution decisions into account, so that the same conflicts 11413 ** do not have to be resolved elsewhere in the network. 11414 ** 11415 ** For example, if both the local and remote changesets contain an 11416 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 11417 ** 11418 ** local: INSERT INTO t1 VALUES(1, 'v1'); 11419 ** remote: INSERT INTO t1 VALUES(1, 'v2'); 11420 ** 11421 ** and the conflict resolution is REPLACE, then the INSERT change is 11422 ** removed from the local changeset (it was overridden). Or, if the 11423 ** conflict resolution was "OMIT", then the local changeset is modified 11424 ** to instead contain: 11425 ** 11426 ** UPDATE t1 SET b = 'v2' WHERE a=1; 11427 ** 11428 ** Changes within the local changeset are rebased as follows: 11429 ** 11430 ** <dl> 11431 ** <dt>Local INSERT<dd> 11432 ** This may only conflict with a remote INSERT. If the conflict 11433 ** resolution was OMIT, then add an UPDATE change to the rebased 11434 ** changeset. Or, if the conflict resolution was REPLACE, add 11435 ** nothing to the rebased changeset. 11436 ** 11437 ** <dt>Local DELETE<dd> 11438 ** This may conflict with a remote UPDATE or DELETE. In both cases the 11439 ** only possible resolution is OMIT. If the remote operation was a 11440 ** DELETE, then add no change to the rebased changeset. If the remote 11441 ** operation was an UPDATE, then the old.* fields of change are updated 11442 ** to reflect the new.* values in the UPDATE. 11443 ** 11444 ** <dt>Local UPDATE<dd> 11445 ** This may conflict with a remote UPDATE or DELETE. If it conflicts 11446 ** with a DELETE, and the conflict resolution was OMIT, then the update 11447 ** is changed into an INSERT. Any undefined values in the new.* record 11448 ** from the update change are filled in using the old.* values from 11449 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 11450 ** the UPDATE change is simply omitted from the rebased changeset. 11451 ** 11452 ** If conflict is with a remote UPDATE and the resolution is OMIT, then 11453 ** the old.* values are rebased using the new.* values in the remote 11454 ** change. Or, if the resolution is REPLACE, then the change is copied 11455 ** into the rebased changeset with updates to columns also updated by 11456 ** the conflicting remote UPDATE removed. If this means no columns would 11457 ** be updated, the change is omitted. 11458 ** </dl> 11459 ** 11460 ** A local change may be rebased against multiple remote changes 11461 ** simultaneously. If a single key is modified by multiple remote 11462 ** changesets, they are combined as follows before the local changeset 11463 ** is rebased: 11464 ** 11465 ** <ul> 11466 ** <li> If there has been one or more REPLACE resolutions on a 11467 ** key, it is rebased according to a REPLACE. 11468 ** 11469 ** <li> If there have been no REPLACE resolutions on a key, then 11470 ** the local changeset is rebased according to the most recent 11471 ** of the OMIT resolutions. 11472 ** </ul> 11473 ** 11474 ** Note that conflict resolutions from multiple remote changesets are 11475 ** combined on a per-field basis, not per-row. This means that in the 11476 ** case of multiple remote UPDATE operations, some fields of a single 11477 ** local change may be rebased for REPLACE while others are rebased for 11478 ** OMIT. 11479 ** 11480 ** In order to rebase a local changeset, the remote changeset must first 11481 ** be applied to the local database using sqlite3changeset_apply_v2() and 11482 ** the buffer of rebase information captured. Then: 11483 ** 11484 ** <ol> 11485 ** <li> An sqlite3_rebaser object is created by calling 11486 ** sqlite3rebaser_create(). 11487 ** <li> The new object is configured with the rebase buffer obtained from 11488 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 11489 ** If the local changeset is to be rebased against multiple remote 11490 ** changesets, then sqlite3rebaser_configure() should be called 11491 ** multiple times, in the same order that the multiple 11492 ** sqlite3changeset_apply_v2() calls were made. 11493 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 11494 ** <li> The sqlite3_rebaser object is deleted by calling 11495 ** sqlite3rebaser_delete(). 11496 ** </ol> 11497 */ 11498 typedef struct sqlite3_rebaser sqlite3_rebaser; 11499 11500 /* 11501 ** CAPI3REF: Create a changeset rebaser object. 11502 ** EXPERIMENTAL 11503 ** 11504 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 11505 ** point to the new object and return SQLITE_OK. Otherwise, if an error 11506 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 11507 ** to NULL. 11508 */ 11509 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 11510 11511 /* 11512 ** CAPI3REF: Configure a changeset rebaser object. 11513 ** EXPERIMENTAL 11514 ** 11515 ** Configure the changeset rebaser object to rebase changesets according 11516 ** to the conflict resolutions described by buffer pRebase (size nRebase 11517 ** bytes), which must have been obtained from a previous call to 11518 ** sqlite3changeset_apply_v2(). 11519 */ 11520 SQLITE_API int sqlite3rebaser_configure( 11521 sqlite3_rebaser*, 11522 int nRebase, const void *pRebase 11523 ); 11524 11525 /* 11526 ** CAPI3REF: Rebase a changeset 11527 ** EXPERIMENTAL 11528 ** 11529 ** Argument pIn must point to a buffer containing a changeset nIn bytes 11530 ** in size. This function allocates and populates a buffer with a copy 11531 ** of the changeset rebased according to the configuration of the 11532 ** rebaser object passed as the first argument. If successful, (*ppOut) 11533 ** is set to point to the new buffer containing the rebased changeset and 11534 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 11535 ** responsibility of the caller to eventually free the new buffer using 11536 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 11537 ** are set to zero and an SQLite error code returned. 11538 */ 11539 SQLITE_API int sqlite3rebaser_rebase( 11540 sqlite3_rebaser*, 11541 int nIn, const void *pIn, 11542 int *pnOut, void **ppOut 11543 ); 11544 11545 /* 11546 ** CAPI3REF: Delete a changeset rebaser object. 11547 ** EXPERIMENTAL 11548 ** 11549 ** Delete the changeset rebaser object and all associated resources. There 11550 ** should be one call to this function for each successful invocation 11551 ** of sqlite3rebaser_create(). 11552 */ 11553 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 11554 11555 /* 11556 ** CAPI3REF: Streaming Versions of API functions. 11557 ** 11558 ** The six streaming API xxx_strm() functions serve similar purposes to the 11559 ** corresponding non-streaming API functions: 11560 ** 11561 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 11562 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 11563 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 11564 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 11565 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 11566 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 11567 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 11568 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 11569 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 11570 ** </table> 11571 ** 11572 ** Non-streaming functions that accept changesets (or patchsets) as input 11573 ** require that the entire changeset be stored in a single buffer in memory. 11574 ** Similarly, those that return a changeset or patchset do so by returning 11575 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 11576 ** Normally this is convenient. However, if an application running in a 11577 ** low-memory environment is required to handle very large changesets, the 11578 ** large contiguous memory allocations required can become onerous. 11579 ** 11580 ** In order to avoid this problem, instead of a single large buffer, input 11581 ** is passed to a streaming API functions by way of a callback function that 11582 ** the sessions module invokes to incrementally request input data as it is 11583 ** required. In all cases, a pair of API function parameters such as 11584 ** 11585 ** <pre> 11586 ** int nChangeset, 11587 ** void *pChangeset, 11588 ** </pre> 11589 ** 11590 ** Is replaced by: 11591 ** 11592 ** <pre> 11593 ** int (*xInput)(void *pIn, void *pData, int *pnData), 11594 ** void *pIn, 11595 ** </pre> 11596 ** 11597 ** Each time the xInput callback is invoked by the sessions module, the first 11598 ** argument passed is a copy of the supplied pIn context pointer. The second 11599 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 11600 ** error occurs the xInput method should copy up to (*pnData) bytes of data 11601 ** into the buffer and set (*pnData) to the actual number of bytes copied 11602 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 11603 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 11604 ** error code should be returned. In all cases, if an xInput callback returns 11605 ** an error, all processing is abandoned and the streaming API function 11606 ** returns a copy of the error code to the caller. 11607 ** 11608 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 11609 ** invoked by the sessions module at any point during the lifetime of the 11610 ** iterator. If such an xInput callback returns an error, the iterator enters 11611 ** an error state, whereby all subsequent calls to iterator functions 11612 ** immediately fail with the same error code as returned by xInput. 11613 ** 11614 ** Similarly, streaming API functions that return changesets (or patchsets) 11615 ** return them in chunks by way of a callback function instead of via a 11616 ** pointer to a single large buffer. In this case, a pair of parameters such 11617 ** as: 11618 ** 11619 ** <pre> 11620 ** int *pnChangeset, 11621 ** void **ppChangeset, 11622 ** </pre> 11623 ** 11624 ** Is replaced by: 11625 ** 11626 ** <pre> 11627 ** int (*xOutput)(void *pOut, const void *pData, int nData), 11628 ** void *pOut 11629 ** </pre> 11630 ** 11631 ** The xOutput callback is invoked zero or more times to return data to 11632 ** the application. The first parameter passed to each call is a copy of the 11633 ** pOut pointer supplied by the application. The second parameter, pData, 11634 ** points to a buffer nData bytes in size containing the chunk of output 11635 ** data being returned. If the xOutput callback successfully processes the 11636 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 11637 ** it should return some other SQLite error code. In this case processing 11638 ** is immediately abandoned and the streaming API function returns a copy 11639 ** of the xOutput error code to the application. 11640 ** 11641 ** The sessions module never invokes an xOutput callback with the third 11642 ** parameter set to a value less than or equal to zero. Other than this, 11643 ** no guarantees are made as to the size of the chunks of data returned. 11644 */ 11645 SQLITE_API int sqlite3changeset_apply_strm( 11646 sqlite3 *db, /* Apply change to "main" db of this handle */ 11647 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 11648 void *pIn, /* First arg for xInput */ 11649 int(*xFilter)( 11650 void *pCtx, /* Copy of sixth arg to _apply() */ 11651 const char *zTab /* Table name */ 11652 ), 11653 int(*xConflict)( 11654 void *pCtx, /* Copy of sixth arg to _apply() */ 11655 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11656 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11657 ), 11658 void *pCtx /* First argument passed to xConflict */ 11659 ); 11660 SQLITE_API int sqlite3changeset_apply_v2_strm( 11661 sqlite3 *db, /* Apply change to "main" db of this handle */ 11662 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 11663 void *pIn, /* First arg for xInput */ 11664 int(*xFilter)( 11665 void *pCtx, /* Copy of sixth arg to _apply() */ 11666 const char *zTab /* Table name */ 11667 ), 11668 int(*xConflict)( 11669 void *pCtx, /* Copy of sixth arg to _apply() */ 11670 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11671 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11672 ), 11673 void *pCtx, /* First argument passed to xConflict */ 11674 void **ppRebase, int *pnRebase, 11675 int flags 11676 ); 11677 SQLITE_API int sqlite3changeset_concat_strm( 11678 int (*xInputA)(void *pIn, void *pData, int *pnData), 11679 void *pInA, 11680 int (*xInputB)(void *pIn, void *pData, int *pnData), 11681 void *pInB, 11682 int (*xOutput)(void *pOut, const void *pData, int nData), 11683 void *pOut 11684 ); 11685 SQLITE_API int sqlite3changeset_invert_strm( 11686 int (*xInput)(void *pIn, void *pData, int *pnData), 11687 void *pIn, 11688 int (*xOutput)(void *pOut, const void *pData, int nData), 11689 void *pOut 11690 ); 11691 SQLITE_API int sqlite3changeset_start_strm( 11692 sqlite3_changeset_iter **pp, 11693 int (*xInput)(void *pIn, void *pData, int *pnData), 11694 void *pIn 11695 ); 11696 SQLITE_API int sqlite3changeset_start_v2_strm( 11697 sqlite3_changeset_iter **pp, 11698 int (*xInput)(void *pIn, void *pData, int *pnData), 11699 void *pIn, 11700 int flags 11701 ); 11702 SQLITE_API int sqlite3session_changeset_strm( 11703 sqlite3_session *pSession, 11704 int (*xOutput)(void *pOut, const void *pData, int nData), 11705 void *pOut 11706 ); 11707 SQLITE_API int sqlite3session_patchset_strm( 11708 sqlite3_session *pSession, 11709 int (*xOutput)(void *pOut, const void *pData, int nData), 11710 void *pOut 11711 ); 11712 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 11713 int (*xInput)(void *pIn, void *pData, int *pnData), 11714 void *pIn 11715 ); 11716 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 11717 int (*xOutput)(void *pOut, const void *pData, int nData), 11718 void *pOut 11719 ); 11720 SQLITE_API int sqlite3rebaser_rebase_strm( 11721 sqlite3_rebaser *pRebaser, 11722 int (*xInput)(void *pIn, void *pData, int *pnData), 11723 void *pIn, 11724 int (*xOutput)(void *pOut, const void *pData, int nData), 11725 void *pOut 11726 ); 11727 11728 /* 11729 ** CAPI3REF: Configure global parameters 11730 ** 11731 ** The sqlite3session_config() interface is used to make global configuration 11732 ** changes to the sessions module in order to tune it to the specific needs 11733 ** of the application. 11734 ** 11735 ** The sqlite3session_config() interface is not threadsafe. If it is invoked 11736 ** while any other thread is inside any other sessions method then the 11737 ** results are undefined. Furthermore, if it is invoked after any sessions 11738 ** related objects have been created, the results are also undefined. 11739 ** 11740 ** The first argument to the sqlite3session_config() function must be one 11741 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The 11742 ** interpretation of the (void*) value passed as the second parameter and 11743 ** the effect of calling this function depends on the value of the first 11744 ** parameter. 11745 ** 11746 ** <dl> 11747 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd> 11748 ** By default, the sessions module streaming interfaces attempt to input 11749 ** and output data in approximately 1 KiB chunks. This operand may be used 11750 ** to set and query the value of this configuration setting. The pointer 11751 ** passed as the second argument must point to a value of type (int). 11752 ** If this value is greater than 0, it is used as the new streaming data 11753 ** chunk size for both input and output. Before returning, the (int) value 11754 ** pointed to by pArg is set to the final value of the streaming interface 11755 ** chunk size. 11756 ** </dl> 11757 ** 11758 ** This function returns SQLITE_OK if successful, or an SQLite error code 11759 ** otherwise. 11760 */ 11761 SQLITE_API int sqlite3session_config(int op, void *pArg); 11762 11763 /* 11764 ** CAPI3REF: Values for sqlite3session_config(). 11765 */ 11766 #define SQLITE_SESSION_CONFIG_STRMSIZE 1 11767 11768 /* 11769 ** Make sure we can call this stuff from C++. 11770 */ 11771 #ifdef __cplusplus 11772 } 11773 #endif 11774 11775 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 11776 11777 /******** End of sqlite3session.h *********/ 11778 /******** Begin file fts5.h *********/ 11779 /* 11780 ** 2014 May 31 11781 ** 11782 ** The author disclaims copyright to this source code. In place of 11783 ** a legal notice, here is a blessing: 11784 ** 11785 ** May you do good and not evil. 11786 ** May you find forgiveness for yourself and forgive others. 11787 ** May you share freely, never taking more than you give. 11788 ** 11789 ****************************************************************************** 11790 ** 11791 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 11792 ** FTS5 may be extended with: 11793 ** 11794 ** * custom tokenizers, and 11795 ** * custom auxiliary functions. 11796 */ 11797 11798 11799 #ifndef _FTS5_H 11800 #define _FTS5_H 11801 11802 11803 #ifdef __cplusplus 11804 extern "C" { 11805 #endif 11806 11807 /************************************************************************* 11808 ** CUSTOM AUXILIARY FUNCTIONS 11809 ** 11810 ** Virtual table implementations may overload SQL functions by implementing 11811 ** the sqlite3_module.xFindFunction() method. 11812 */ 11813 11814 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 11815 typedef struct Fts5Context Fts5Context; 11816 typedef struct Fts5PhraseIter Fts5PhraseIter; 11817 11818 typedef void (*fts5_extension_function)( 11819 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 11820 Fts5Context *pFts, /* First arg to pass to pApi functions */ 11821 sqlite3_context *pCtx, /* Context for returning result/error */ 11822 int nVal, /* Number of values in apVal[] array */ 11823 sqlite3_value **apVal /* Array of trailing arguments */ 11824 ); 11825 11826 struct Fts5PhraseIter { 11827 const unsigned char *a; 11828 const unsigned char *b; 11829 }; 11830 11831 /* 11832 ** EXTENSION API FUNCTIONS 11833 ** 11834 ** xUserData(pFts): 11835 ** Return a copy of the context pointer the extension function was 11836 ** registered with. 11837 ** 11838 ** xColumnTotalSize(pFts, iCol, pnToken): 11839 ** If parameter iCol is less than zero, set output variable *pnToken 11840 ** to the total number of tokens in the FTS5 table. Or, if iCol is 11841 ** non-negative but less than the number of columns in the table, return 11842 ** the total number of tokens in column iCol, considering all rows in 11843 ** the FTS5 table. 11844 ** 11845 ** If parameter iCol is greater than or equal to the number of columns 11846 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11847 ** an OOM condition or IO error), an appropriate SQLite error code is 11848 ** returned. 11849 ** 11850 ** xColumnCount(pFts): 11851 ** Return the number of columns in the table. 11852 ** 11853 ** xColumnSize(pFts, iCol, pnToken): 11854 ** If parameter iCol is less than zero, set output variable *pnToken 11855 ** to the total number of tokens in the current row. Or, if iCol is 11856 ** non-negative but less than the number of columns in the table, set 11857 ** *pnToken to the number of tokens in column iCol of the current row. 11858 ** 11859 ** If parameter iCol is greater than or equal to the number of columns 11860 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11861 ** an OOM condition or IO error), an appropriate SQLite error code is 11862 ** returned. 11863 ** 11864 ** This function may be quite inefficient if used with an FTS5 table 11865 ** created with the "columnsize=0" option. 11866 ** 11867 ** xColumnText: 11868 ** This function attempts to retrieve the text of column iCol of the 11869 ** current document. If successful, (*pz) is set to point to a buffer 11870 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 11871 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 11872 ** if an error occurs, an SQLite error code is returned and the final values 11873 ** of (*pz) and (*pn) are undefined. 11874 ** 11875 ** xPhraseCount: 11876 ** Returns the number of phrases in the current query expression. 11877 ** 11878 ** xPhraseSize: 11879 ** Returns the number of tokens in phrase iPhrase of the query. Phrases 11880 ** are numbered starting from zero. 11881 ** 11882 ** xInstCount: 11883 ** Set *pnInst to the total number of occurrences of all phrases within 11884 ** the query within the current row. Return SQLITE_OK if successful, or 11885 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 11886 ** 11887 ** This API can be quite slow if used with an FTS5 table created with the 11888 ** "detail=none" or "detail=column" option. If the FTS5 table is created 11889 ** with either "detail=none" or "detail=column" and "content=" option 11890 ** (i.e. if it is a contentless table), then this API always returns 0. 11891 ** 11892 ** xInst: 11893 ** Query for the details of phrase match iIdx within the current row. 11894 ** Phrase matches are numbered starting from zero, so the iIdx argument 11895 ** should be greater than or equal to zero and smaller than the value 11896 ** output by xInstCount(). 11897 ** 11898 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol 11899 ** to the column in which it occurs and *piOff the token offset of the 11900 ** first token of the phrase. Returns SQLITE_OK if successful, or an error 11901 ** code (i.e. SQLITE_NOMEM) if an error occurs. 11902 ** 11903 ** This API can be quite slow if used with an FTS5 table created with the 11904 ** "detail=none" or "detail=column" option. 11905 ** 11906 ** xRowid: 11907 ** Returns the rowid of the current row. 11908 ** 11909 ** xTokenize: 11910 ** Tokenize text using the tokenizer belonging to the FTS5 table. 11911 ** 11912 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 11913 ** This API function is used to query the FTS table for phrase iPhrase 11914 ** of the current query. Specifically, a query equivalent to: 11915 ** 11916 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 11917 ** 11918 ** with $p set to a phrase equivalent to the phrase iPhrase of the 11919 ** current query is executed. Any column filter that applies to 11920 ** phrase iPhrase of the current query is included in $p. For each 11921 ** row visited, the callback function passed as the fourth argument 11922 ** is invoked. The context and API objects passed to the callback 11923 ** function may be used to access the properties of each matched row. 11924 ** Invoking Api.xUserData() returns a copy of the pointer passed as 11925 ** the third argument to pUserData. 11926 ** 11927 ** If the callback function returns any value other than SQLITE_OK, the 11928 ** query is abandoned and the xQueryPhrase function returns immediately. 11929 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 11930 ** Otherwise, the error code is propagated upwards. 11931 ** 11932 ** If the query runs to completion without incident, SQLITE_OK is returned. 11933 ** Or, if some error occurs before the query completes or is aborted by 11934 ** the callback, an SQLite error code is returned. 11935 ** 11936 ** 11937 ** xSetAuxdata(pFts5, pAux, xDelete) 11938 ** 11939 ** Save the pointer passed as the second argument as the extension function's 11940 ** "auxiliary data". The pointer may then be retrieved by the current or any 11941 ** future invocation of the same fts5 extension function made as part of 11942 ** the same MATCH query using the xGetAuxdata() API. 11943 ** 11944 ** Each extension function is allocated a single auxiliary data slot for 11945 ** each FTS query (MATCH expression). If the extension function is invoked 11946 ** more than once for a single FTS query, then all invocations share a 11947 ** single auxiliary data context. 11948 ** 11949 ** If there is already an auxiliary data pointer when this function is 11950 ** invoked, then it is replaced by the new pointer. If an xDelete callback 11951 ** was specified along with the original pointer, it is invoked at this 11952 ** point. 11953 ** 11954 ** The xDelete callback, if one is specified, is also invoked on the 11955 ** auxiliary data pointer after the FTS5 query has finished. 11956 ** 11957 ** If an error (e.g. an OOM condition) occurs within this function, 11958 ** the auxiliary data is set to NULL and an error code returned. If the 11959 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 11960 ** pointer before returning. 11961 ** 11962 ** 11963 ** xGetAuxdata(pFts5, bClear) 11964 ** 11965 ** Returns the current auxiliary data pointer for the fts5 extension 11966 ** function. See the xSetAuxdata() method for details. 11967 ** 11968 ** If the bClear argument is non-zero, then the auxiliary data is cleared 11969 ** (set to NULL) before this function returns. In this case the xDelete, 11970 ** if any, is not invoked. 11971 ** 11972 ** 11973 ** xRowCount(pFts5, pnRow) 11974 ** 11975 ** This function is used to retrieve the total number of rows in the table. 11976 ** In other words, the same value that would be returned by: 11977 ** 11978 ** SELECT count(*) FROM ftstable; 11979 ** 11980 ** xPhraseFirst() 11981 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 11982 ** method, to iterate through all instances of a single query phrase within 11983 ** the current row. This is the same information as is accessible via the 11984 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 11985 ** to use, this API may be faster under some circumstances. To iterate 11986 ** through instances of phrase iPhrase, use the following code: 11987 ** 11988 ** Fts5PhraseIter iter; 11989 ** int iCol, iOff; 11990 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 11991 ** iCol>=0; 11992 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 11993 ** ){ 11994 ** // An instance of phrase iPhrase at offset iOff of column iCol 11995 ** } 11996 ** 11997 ** The Fts5PhraseIter structure is defined above. Applications should not 11998 ** modify this structure directly - it should only be used as shown above 11999 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 12000 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 12001 ** 12002 ** This API can be quite slow if used with an FTS5 table created with the 12003 ** "detail=none" or "detail=column" option. If the FTS5 table is created 12004 ** with either "detail=none" or "detail=column" and "content=" option 12005 ** (i.e. if it is a contentless table), then this API always iterates 12006 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 12007 ** 12008 ** xPhraseNext() 12009 ** See xPhraseFirst above. 12010 ** 12011 ** xPhraseFirstColumn() 12012 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 12013 ** and xPhraseNext() APIs described above. The difference is that instead 12014 ** of iterating through all instances of a phrase in the current row, these 12015 ** APIs are used to iterate through the set of columns in the current row 12016 ** that contain one or more instances of a specified phrase. For example: 12017 ** 12018 ** Fts5PhraseIter iter; 12019 ** int iCol; 12020 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 12021 ** iCol>=0; 12022 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 12023 ** ){ 12024 ** // Column iCol contains at least one instance of phrase iPhrase 12025 ** } 12026 ** 12027 ** This API can be quite slow if used with an FTS5 table created with the 12028 ** "detail=none" option. If the FTS5 table is created with either 12029 ** "detail=none" "content=" option (i.e. if it is a contentless table), 12030 ** then this API always iterates through an empty set (all calls to 12031 ** xPhraseFirstColumn() set iCol to -1). 12032 ** 12033 ** The information accessed using this API and its companion 12034 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 12035 ** (or xInst/xInstCount). The chief advantage of this API is that it is 12036 ** significantly more efficient than those alternatives when used with 12037 ** "detail=column" tables. 12038 ** 12039 ** xPhraseNextColumn() 12040 ** See xPhraseFirstColumn above. 12041 */ 12042 struct Fts5ExtensionApi { 12043 int iVersion; /* Currently always set to 3 */ 12044 12045 void *(*xUserData)(Fts5Context*); 12046 12047 int (*xColumnCount)(Fts5Context*); 12048 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 12049 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 12050 12051 int (*xTokenize)(Fts5Context*, 12052 const char *pText, int nText, /* Text to tokenize */ 12053 void *pCtx, /* Context passed to xToken() */ 12054 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 12055 ); 12056 12057 int (*xPhraseCount)(Fts5Context*); 12058 int (*xPhraseSize)(Fts5Context*, int iPhrase); 12059 12060 int (*xInstCount)(Fts5Context*, int *pnInst); 12061 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 12062 12063 sqlite3_int64 (*xRowid)(Fts5Context*); 12064 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 12065 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 12066 12067 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 12068 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 12069 ); 12070 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 12071 void *(*xGetAuxdata)(Fts5Context*, int bClear); 12072 12073 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 12074 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 12075 12076 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 12077 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 12078 }; 12079 12080 /* 12081 ** CUSTOM AUXILIARY FUNCTIONS 12082 *************************************************************************/ 12083 12084 /************************************************************************* 12085 ** CUSTOM TOKENIZERS 12086 ** 12087 ** Applications may also register custom tokenizer types. A tokenizer 12088 ** is registered by providing fts5 with a populated instance of the 12089 ** following structure. All structure methods must be defined, setting 12090 ** any member of the fts5_tokenizer struct to NULL leads to undefined 12091 ** behaviour. The structure methods are expected to function as follows: 12092 ** 12093 ** xCreate: 12094 ** This function is used to allocate and initialize a tokenizer instance. 12095 ** A tokenizer instance is required to actually tokenize text. 12096 ** 12097 ** The first argument passed to this function is a copy of the (void*) 12098 ** pointer provided by the application when the fts5_tokenizer object 12099 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 12100 ** The second and third arguments are an array of nul-terminated strings 12101 ** containing the tokenizer arguments, if any, specified following the 12102 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 12103 ** to create the FTS5 table. 12104 ** 12105 ** The final argument is an output variable. If successful, (*ppOut) 12106 ** should be set to point to the new tokenizer handle and SQLITE_OK 12107 ** returned. If an error occurs, some value other than SQLITE_OK should 12108 ** be returned. In this case, fts5 assumes that the final value of *ppOut 12109 ** is undefined. 12110 ** 12111 ** xDelete: 12112 ** This function is invoked to delete a tokenizer handle previously 12113 ** allocated using xCreate(). Fts5 guarantees that this function will 12114 ** be invoked exactly once for each successful call to xCreate(). 12115 ** 12116 ** xTokenize: 12117 ** This function is expected to tokenize the nText byte string indicated 12118 ** by argument pText. pText may or may not be nul-terminated. The first 12119 ** argument passed to this function is a pointer to an Fts5Tokenizer object 12120 ** returned by an earlier call to xCreate(). 12121 ** 12122 ** The second argument indicates the reason that FTS5 is requesting 12123 ** tokenization of the supplied text. This is always one of the following 12124 ** four values: 12125 ** 12126 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 12127 ** or removed from the FTS table. The tokenizer is being invoked to 12128 ** determine the set of tokens to add to (or delete from) the 12129 ** FTS index. 12130 ** 12131 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 12132 ** against the FTS index. The tokenizer is being called to tokenize 12133 ** a bareword or quoted string specified as part of the query. 12134 ** 12135 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 12136 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 12137 ** followed by a "*" character, indicating that the last token 12138 ** returned by the tokenizer will be treated as a token prefix. 12139 ** 12140 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 12141 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 12142 ** function. Or an fts5_api.xColumnSize() request made by the same 12143 ** on a columnsize=0 database. 12144 ** </ul> 12145 ** 12146 ** For each token in the input string, the supplied callback xToken() must 12147 ** be invoked. The first argument to it should be a copy of the pointer 12148 ** passed as the second argument to xTokenize(). The third and fourth 12149 ** arguments are a pointer to a buffer containing the token text, and the 12150 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 12151 ** of the first byte of and first byte immediately following the text from 12152 ** which the token is derived within the input. 12153 ** 12154 ** The second argument passed to the xToken() callback ("tflags") should 12155 ** normally be set to 0. The exception is if the tokenizer supports 12156 ** synonyms. In this case see the discussion below for details. 12157 ** 12158 ** FTS5 assumes the xToken() callback is invoked for each token in the 12159 ** order that they occur within the input text. 12160 ** 12161 ** If an xToken() callback returns any value other than SQLITE_OK, then 12162 ** the tokenization should be abandoned and the xTokenize() method should 12163 ** immediately return a copy of the xToken() return value. Or, if the 12164 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 12165 ** if an error occurs with the xTokenize() implementation itself, it 12166 ** may abandon the tokenization and return any error code other than 12167 ** SQLITE_OK or SQLITE_DONE. 12168 ** 12169 ** SYNONYM SUPPORT 12170 ** 12171 ** Custom tokenizers may also support synonyms. Consider a case in which a 12172 ** user wishes to query for a phrase such as "first place". Using the 12173 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 12174 ** of "first place" within the document set, but not alternative forms 12175 ** such as "1st place". In some applications, it would be better to match 12176 ** all instances of "first place" or "1st place" regardless of which form 12177 ** the user specified in the MATCH query text. 12178 ** 12179 ** There are several ways to approach this in FTS5: 12180 ** 12181 ** <ol><li> By mapping all synonyms to a single token. In this case, using 12182 ** the above example, this means that the tokenizer returns the 12183 ** same token for inputs "first" and "1st". Say that token is in 12184 ** fact "first", so that when the user inserts the document "I won 12185 ** 1st place" entries are added to the index for tokens "i", "won", 12186 ** "first" and "place". If the user then queries for '1st + place', 12187 ** the tokenizer substitutes "first" for "1st" and the query works 12188 ** as expected. 12189 ** 12190 ** <li> By querying the index for all synonyms of each query term 12191 ** separately. In this case, when tokenizing query text, the 12192 ** tokenizer may provide multiple synonyms for a single term 12193 ** within the document. FTS5 then queries the index for each 12194 ** synonym individually. For example, faced with the query: 12195 ** 12196 ** <codeblock> 12197 ** ... MATCH 'first place'</codeblock> 12198 ** 12199 ** the tokenizer offers both "1st" and "first" as synonyms for the 12200 ** first token in the MATCH query and FTS5 effectively runs a query 12201 ** similar to: 12202 ** 12203 ** <codeblock> 12204 ** ... MATCH '(first OR 1st) place'</codeblock> 12205 ** 12206 ** except that, for the purposes of auxiliary functions, the query 12207 ** still appears to contain just two phrases - "(first OR 1st)" 12208 ** being treated as a single phrase. 12209 ** 12210 ** <li> By adding multiple synonyms for a single term to the FTS index. 12211 ** Using this method, when tokenizing document text, the tokenizer 12212 ** provides multiple synonyms for each token. So that when a 12213 ** document such as "I won first place" is tokenized, entries are 12214 ** added to the FTS index for "i", "won", "first", "1st" and 12215 ** "place". 12216 ** 12217 ** This way, even if the tokenizer does not provide synonyms 12218 ** when tokenizing query text (it should not - to do so would be 12219 ** inefficient), it doesn't matter if the user queries for 12220 ** 'first + place' or '1st + place', as there are entries in the 12221 ** FTS index corresponding to both forms of the first token. 12222 ** </ol> 12223 ** 12224 ** Whether it is parsing document or query text, any call to xToken that 12225 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 12226 ** is considered to supply a synonym for the previous token. For example, 12227 ** when parsing the document "I won first place", a tokenizer that supports 12228 ** synonyms would call xToken() 5 times, as follows: 12229 ** 12230 ** <codeblock> 12231 ** xToken(pCtx, 0, "i", 1, 0, 1); 12232 ** xToken(pCtx, 0, "won", 3, 2, 5); 12233 ** xToken(pCtx, 0, "first", 5, 6, 11); 12234 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 12235 ** xToken(pCtx, 0, "place", 5, 12, 17); 12236 **</codeblock> 12237 ** 12238 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 12239 ** xToken() is called. Multiple synonyms may be specified for a single token 12240 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 12241 ** There is no limit to the number of synonyms that may be provided for a 12242 ** single token. 12243 ** 12244 ** In many cases, method (1) above is the best approach. It does not add 12245 ** extra data to the FTS index or require FTS5 to query for multiple terms, 12246 ** so it is efficient in terms of disk space and query speed. However, it 12247 ** does not support prefix queries very well. If, as suggested above, the 12248 ** token "first" is substituted for "1st" by the tokenizer, then the query: 12249 ** 12250 ** <codeblock> 12251 ** ... MATCH '1s*'</codeblock> 12252 ** 12253 ** will not match documents that contain the token "1st" (as the tokenizer 12254 ** will probably not map "1s" to any prefix of "first"). 12255 ** 12256 ** For full prefix support, method (3) may be preferred. In this case, 12257 ** because the index contains entries for both "first" and "1st", prefix 12258 ** queries such as 'fi*' or '1s*' will match correctly. However, because 12259 ** extra entries are added to the FTS index, this method uses more space 12260 ** within the database. 12261 ** 12262 ** Method (2) offers a midpoint between (1) and (3). Using this method, 12263 ** a query such as '1s*' will match documents that contain the literal 12264 ** token "1st", but not "first" (assuming the tokenizer is not able to 12265 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 12266 ** will match against "1st" and "first". This method does not require 12267 ** extra disk space, as no extra entries are added to the FTS index. 12268 ** On the other hand, it may require more CPU cycles to run MATCH queries, 12269 ** as separate queries of the FTS index are required for each synonym. 12270 ** 12271 ** When using methods (2) or (3), it is important that the tokenizer only 12272 ** provide synonyms when tokenizing document text (method (2)) or query 12273 ** text (method (3)), not both. Doing so will not cause any errors, but is 12274 ** inefficient. 12275 */ 12276 typedef struct Fts5Tokenizer Fts5Tokenizer; 12277 typedef struct fts5_tokenizer fts5_tokenizer; 12278 struct fts5_tokenizer { 12279 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 12280 void (*xDelete)(Fts5Tokenizer*); 12281 int (*xTokenize)(Fts5Tokenizer*, 12282 void *pCtx, 12283 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 12284 const char *pText, int nText, 12285 int (*xToken)( 12286 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 12287 int tflags, /* Mask of FTS5_TOKEN_* flags */ 12288 const char *pToken, /* Pointer to buffer containing token */ 12289 int nToken, /* Size of token in bytes */ 12290 int iStart, /* Byte offset of token within input text */ 12291 int iEnd /* Byte offset of end of token within input text */ 12292 ) 12293 ); 12294 }; 12295 12296 /* Flags that may be passed as the third argument to xTokenize() */ 12297 #define FTS5_TOKENIZE_QUERY 0x0001 12298 #define FTS5_TOKENIZE_PREFIX 0x0002 12299 #define FTS5_TOKENIZE_DOCUMENT 0x0004 12300 #define FTS5_TOKENIZE_AUX 0x0008 12301 12302 /* Flags that may be passed by the tokenizer implementation back to FTS5 12303 ** as the third argument to the supplied xToken callback. */ 12304 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 12305 12306 /* 12307 ** END OF CUSTOM TOKENIZERS 12308 *************************************************************************/ 12309 12310 /************************************************************************* 12311 ** FTS5 EXTENSION REGISTRATION API 12312 */ 12313 typedef struct fts5_api fts5_api; 12314 struct fts5_api { 12315 int iVersion; /* Currently always set to 2 */ 12316 12317 /* Create a new tokenizer */ 12318 int (*xCreateTokenizer)( 12319 fts5_api *pApi, 12320 const char *zName, 12321 void *pContext, 12322 fts5_tokenizer *pTokenizer, 12323 void (*xDestroy)(void*) 12324 ); 12325 12326 /* Find an existing tokenizer */ 12327 int (*xFindTokenizer)( 12328 fts5_api *pApi, 12329 const char *zName, 12330 void **ppContext, 12331 fts5_tokenizer *pTokenizer 12332 ); 12333 12334 /* Create a new auxiliary function */ 12335 int (*xCreateFunction)( 12336 fts5_api *pApi, 12337 const char *zName, 12338 void *pContext, 12339 fts5_extension_function xFunction, 12340 void (*xDestroy)(void*) 12341 ); 12342 }; 12343 12344 /* 12345 ** END OF REGISTRATION API 12346 *************************************************************************/ 12347 12348 #ifdef __cplusplus 12349 } /* end of the 'extern "C"' block */ 12350 #endif 12351 12352 #endif /* _FTS5_H */ 12353 12354 /******** End of fts5.h *********/ 12355 #else // USE_LIBSQLITE3 12356 // If users really want to link against the system sqlite3 we 12357 // need to make this file a noop. 12358 #endif 12359 /* 12360 ** 2014-09-08 12361 ** 12362 ** The author disclaims copyright to this source code. In place of 12363 ** a legal notice, here is a blessing: 12364 ** 12365 ** May you do good and not evil. 12366 ** May you find forgiveness for yourself and forgive others. 12367 ** May you share freely, never taking more than you give. 12368 ** 12369 ************************************************************************* 12370 ** 12371 ** This file contains the application interface definitions for the 12372 ** user-authentication extension feature. 12373 ** 12374 ** To compile with the user-authentication feature, append this file to 12375 ** end of an SQLite amalgamation header file ("sqlite3.h"), then add 12376 ** the SQLITE_USER_AUTHENTICATION compile-time option. See the 12377 ** user-auth.txt file in the same source directory as this file for 12378 ** additional information. 12379 */ 12380 #ifdef SQLITE_USER_AUTHENTICATION 12381 12382 #ifdef __cplusplus 12383 extern "C" { 12384 #endif 12385 12386 /* 12387 ** If a database contains the SQLITE_USER table, then the 12388 ** sqlite3_user_authenticate() interface must be invoked with an 12389 ** appropriate username and password prior to enable read and write 12390 ** access to the database. 12391 ** 12392 ** Return SQLITE_OK on success or SQLITE_ERROR if the username/password 12393 ** combination is incorrect or unknown. 12394 ** 12395 ** If the SQLITE_USER table is not present in the database file, then 12396 ** this interface is a harmless no-op returnning SQLITE_OK. 12397 */ 12398 int sqlite3_user_authenticate( 12399 sqlite3 *db, /* The database connection */ 12400 const char *zUsername, /* Username */ 12401 const char *aPW, /* Password or credentials */ 12402 int nPW /* Number of bytes in aPW[] */ 12403 ); 12404 12405 /* 12406 ** The sqlite3_user_add() interface can be used (by an admin user only) 12407 ** to create a new user. When called on a no-authentication-required 12408 ** database, this routine converts the database into an authentication- 12409 ** required database, automatically makes the added user an 12410 ** administrator, and logs in the current connection as that user. 12411 ** The sqlite3_user_add() interface only works for the "main" database, not 12412 ** for any ATTACH-ed databases. Any call to sqlite3_user_add() by a 12413 ** non-admin user results in an error. 12414 */ 12415 int sqlite3_user_add( 12416 sqlite3 *db, /* Database connection */ 12417 const char *zUsername, /* Username to be added */ 12418 const char *aPW, /* Password or credentials */ 12419 int nPW, /* Number of bytes in aPW[] */ 12420 int isAdmin /* True to give new user admin privilege */ 12421 ); 12422 12423 /* 12424 ** The sqlite3_user_change() interface can be used to change a users 12425 ** login credentials or admin privilege. Any user can change their own 12426 ** login credentials. Only an admin user can change another users login 12427 ** credentials or admin privilege setting. No user may change their own 12428 ** admin privilege setting. 12429 */ 12430 int sqlite3_user_change( 12431 sqlite3 *db, /* Database connection */ 12432 const char *zUsername, /* Username to change */ 12433 const char *aPW, /* New password or credentials */ 12434 int nPW, /* Number of bytes in aPW[] */ 12435 int isAdmin /* Modified admin privilege for the user */ 12436 ); 12437 12438 /* 12439 ** The sqlite3_user_delete() interface can be used (by an admin user only) 12440 ** to delete a user. The currently logged-in user cannot be deleted, 12441 ** which guarantees that there is always an admin user and hence that 12442 ** the database cannot be converted into a no-authentication-required 12443 ** database. 12444 */ 12445 int sqlite3_user_delete( 12446 sqlite3 *db, /* Database connection */ 12447 const char *zUsername /* Username to remove */ 12448 ); 12449 12450 #ifdef __cplusplus 12451 } /* end of the 'extern "C"' block */ 12452 #endif 12453 12454 #endif /* SQLITE_USER_AUTHENTICATION */ 12455