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 "3.25.2" 128 #define SQLITE_VERSION_NUMBER 3025002 129 #define SQLITE_SOURCE_ID "2018-09-25 19:08:10 fb90e7189ae6d62e77ba3a308ca5d683f90bbe633cf681865365b8e92792d1c7" 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 #endif 194 195 /* 196 ** CAPI3REF: Test To See If The Library Is Threadsafe 197 ** 198 ** ^The sqlite3_threadsafe() function returns zero if and only if 199 ** SQLite was compiled with mutexing code omitted due to the 200 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 201 ** 202 ** SQLite can be compiled with or without mutexes. When 203 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 204 ** are enabled and SQLite is threadsafe. When the 205 ** [SQLITE_THREADSAFE] macro is 0, 206 ** the mutexes are omitted. Without the mutexes, it is not safe 207 ** to use SQLite concurrently from more than one thread. 208 ** 209 ** Enabling mutexes incurs a measurable performance penalty. 210 ** So if speed is of utmost importance, it makes sense to disable 211 ** the mutexes. But for maximum safety, mutexes should be enabled. 212 ** ^The default behavior is for mutexes to be enabled. 213 ** 214 ** This interface can be used by an application to make sure that the 215 ** version of SQLite that it is linking against was compiled with 216 ** the desired setting of the [SQLITE_THREADSAFE] macro. 217 ** 218 ** This interface only reports on the compile-time mutex setting 219 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 220 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 221 ** can be fully or partially disabled using a call to [sqlite3_config()] 222 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 223 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 224 ** sqlite3_threadsafe() function shows only the compile-time setting of 225 ** thread safety, not any run-time changes to that setting made by 226 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 227 ** is unchanged by calls to sqlite3_config().)^ 228 ** 229 ** See the [threading mode] documentation for additional information. 230 */ 231 SQLITE_API int sqlite3_threadsafe(void); 232 233 /* 234 ** CAPI3REF: Database Connection Handle 235 ** KEYWORDS: {database connection} {database connections} 236 ** 237 ** Each open SQLite database is represented by a pointer to an instance of 238 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 239 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 240 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 241 ** and [sqlite3_close_v2()] are its destructors. There are many other 242 ** interfaces (such as 243 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 244 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 245 ** sqlite3 object. 246 */ 247 typedef struct sqlite3 sqlite3; 248 249 /* 250 ** CAPI3REF: 64-Bit Integer Types 251 ** KEYWORDS: sqlite_int64 sqlite_uint64 252 ** 253 ** Because there is no cross-platform way to specify 64-bit integer types 254 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 255 ** 256 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 257 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 258 ** compatibility only. 259 ** 260 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 261 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 262 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 263 ** between 0 and +18446744073709551615 inclusive. 264 */ 265 #ifdef SQLITE_INT64_TYPE 266 typedef SQLITE_INT64_TYPE sqlite_int64; 267 # ifdef SQLITE_UINT64_TYPE 268 typedef SQLITE_UINT64_TYPE sqlite_uint64; 269 # else 270 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 271 # endif 272 #elif defined(_MSC_VER) || defined(__BORLANDC__) 273 typedef __int64 sqlite_int64; 274 typedef unsigned __int64 sqlite_uint64; 275 #else 276 typedef long long int sqlite_int64; 277 typedef unsigned long long int sqlite_uint64; 278 #endif 279 typedef sqlite_int64 sqlite3_int64; 280 typedef sqlite_uint64 sqlite3_uint64; 281 282 /* 283 ** If compiling for a processor that lacks floating point support, 284 ** substitute integer for floating-point. 285 */ 286 #ifdef SQLITE_OMIT_FLOATING_POINT 287 # define double sqlite3_int64 288 #endif 289 290 /* 291 ** CAPI3REF: Closing A Database Connection 292 ** DESTRUCTOR: sqlite3 293 ** 294 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 295 ** for the [sqlite3] object. 296 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 297 ** the [sqlite3] object is successfully destroyed and all associated 298 ** resources are deallocated. 299 ** 300 ** ^If the database connection is associated with unfinalized prepared 301 ** statements or unfinished sqlite3_backup objects then sqlite3_close() 302 ** will leave the database connection open and return [SQLITE_BUSY]. 303 ** ^If sqlite3_close_v2() is called with unfinalized prepared statements 304 ** and/or unfinished sqlite3_backups, then the database connection becomes 305 ** an unusable "zombie" which will automatically be deallocated when the 306 ** last prepared statement is finalized or the last sqlite3_backup is 307 ** finished. The sqlite3_close_v2() interface is intended for use with 308 ** host languages that are garbage collected, and where the order in which 309 ** destructors are called is arbitrary. 310 ** 311 ** Applications should [sqlite3_finalize | finalize] all [prepared statements], 312 ** [sqlite3_blob_close | close] all [BLOB handles], and 313 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 314 ** with the [sqlite3] object prior to attempting to close the object. ^If 315 ** sqlite3_close_v2() is called on a [database connection] that still has 316 ** outstanding [prepared statements], [BLOB handles], and/or 317 ** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 318 ** of resources is deferred until all [prepared statements], [BLOB handles], 319 ** and [sqlite3_backup] objects are also destroyed. 320 ** 321 ** ^If an [sqlite3] object is destroyed while a transaction is open, 322 ** the transaction is automatically rolled back. 323 ** 324 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 325 ** must be either a NULL 326 ** pointer or an [sqlite3] object pointer obtained 327 ** from [sqlite3_open()], [sqlite3_open16()], or 328 ** [sqlite3_open_v2()], and not previously closed. 329 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 330 ** argument is a harmless no-op. 331 */ 332 SQLITE_API int sqlite3_close(sqlite3*); 333 SQLITE_API int sqlite3_close_v2(sqlite3*); 334 335 /* 336 ** The type for a callback function. 337 ** This is legacy and deprecated. It is included for historical 338 ** compatibility and is not documented. 339 */ 340 typedef int (*sqlite3_callback)(void*,int,char**, char**); 341 342 /* 343 ** CAPI3REF: One-Step Query Execution Interface 344 ** METHOD: sqlite3 345 ** 346 ** The sqlite3_exec() interface is a convenience wrapper around 347 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 348 ** that allows an application to run multiple statements of SQL 349 ** without having to use a lot of C code. 350 ** 351 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 352 ** semicolon-separate SQL statements passed into its 2nd argument, 353 ** in the context of the [database connection] passed in as its 1st 354 ** argument. ^If the callback function of the 3rd argument to 355 ** sqlite3_exec() is not NULL, then it is invoked for each result row 356 ** coming out of the evaluated SQL statements. ^The 4th argument to 357 ** sqlite3_exec() is relayed through to the 1st argument of each 358 ** callback invocation. ^If the callback pointer to sqlite3_exec() 359 ** is NULL, then no callback is ever invoked and result rows are 360 ** ignored. 361 ** 362 ** ^If an error occurs while evaluating the SQL statements passed into 363 ** sqlite3_exec(), then execution of the current statement stops and 364 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 365 ** is not NULL then any error message is written into memory obtained 366 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 367 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 368 ** on error message strings returned through the 5th parameter of 369 ** sqlite3_exec() after the error message string is no longer needed. 370 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 371 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 372 ** NULL before returning. 373 ** 374 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 375 ** routine returns SQLITE_ABORT without invoking the callback again and 376 ** without running any subsequent SQL statements. 377 ** 378 ** ^The 2nd argument to the sqlite3_exec() callback function is the 379 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 380 ** callback is an array of pointers to strings obtained as if from 381 ** [sqlite3_column_text()], one for each column. ^If an element of a 382 ** result row is NULL then the corresponding string pointer for the 383 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 384 ** sqlite3_exec() callback is an array of pointers to strings where each 385 ** entry represents the name of corresponding result column as obtained 386 ** from [sqlite3_column_name()]. 387 ** 388 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 389 ** to an empty string, or a pointer that contains only whitespace and/or 390 ** SQL comments, then no SQL statements are evaluated and the database 391 ** is not changed. 392 ** 393 ** Restrictions: 394 ** 395 ** <ul> 396 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 397 ** is a valid and open [database connection]. 398 ** <li> The application must not close the [database connection] specified by 399 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 400 ** <li> The application must not modify the SQL statement text passed into 401 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 402 ** </ul> 403 */ 404 SQLITE_API int sqlite3_exec( 405 sqlite3*, /* An open database */ 406 const char *sql, /* SQL to be evaluated */ 407 int (*callback)(void*,int,char**,char**), /* Callback function */ 408 void *, /* 1st argument to callback */ 409 char **errmsg /* Error msg written here */ 410 ); 411 412 /* 413 ** CAPI3REF: Result Codes 414 ** KEYWORDS: {result code definitions} 415 ** 416 ** Many SQLite functions return an integer result code from the set shown 417 ** here in order to indicate success or failure. 418 ** 419 ** New error codes may be added in future versions of SQLite. 420 ** 421 ** See also: [extended result code definitions] 422 */ 423 #define SQLITE_OK 0 /* Successful result */ 424 /* beginning-of-error-codes */ 425 #define SQLITE_ERROR 1 /* Generic error */ 426 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 427 #define SQLITE_PERM 3 /* Access permission denied */ 428 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 429 #define SQLITE_BUSY 5 /* The database file is locked */ 430 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 431 #define SQLITE_NOMEM 7 /* A malloc() failed */ 432 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 433 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 434 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 435 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 436 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 437 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 438 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 439 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 440 #define SQLITE_EMPTY 16 /* Internal use only */ 441 #define SQLITE_SCHEMA 17 /* The database schema changed */ 442 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 443 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 444 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 445 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 446 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 447 #define SQLITE_AUTH 23 /* Authorization denied */ 448 #define SQLITE_FORMAT 24 /* Not used */ 449 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 450 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 451 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 452 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 453 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 454 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 455 /* end-of-error-codes */ 456 457 /* 458 ** CAPI3REF: Extended Result Codes 459 ** KEYWORDS: {extended result code definitions} 460 ** 461 ** In its default configuration, SQLite API routines return one of 30 integer 462 ** [result codes]. However, experience has shown that many of 463 ** these result codes are too coarse-grained. They do not provide as 464 ** much information about problems as programmers might like. In an effort to 465 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 466 ** and later) include 467 ** support for additional result codes that provide more detailed information 468 ** about errors. These [extended result codes] are enabled or disabled 469 ** on a per database connection basis using the 470 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 471 ** the most recent error can be obtained using 472 ** [sqlite3_extended_errcode()]. 473 */ 474 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 475 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 476 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 477 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 478 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 479 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 480 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 481 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 482 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 483 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 484 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 485 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 486 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 487 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 488 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 489 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 490 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 491 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 492 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 493 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 494 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 495 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 496 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 497 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 498 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 499 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 500 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 501 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 502 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 503 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 504 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 505 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 506 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 507 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 508 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 509 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 510 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 511 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 512 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 513 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 514 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 515 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 516 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 517 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 518 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 519 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 520 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 521 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 522 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 523 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 524 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 525 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 526 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 527 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 528 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 529 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 530 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 531 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 532 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 533 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 534 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 535 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 536 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 537 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 538 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 539 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 540 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 541 542 /* 543 ** CAPI3REF: Flags For File Open Operations 544 ** 545 ** These bit values are intended for use in the 546 ** 3rd parameter to the [sqlite3_open_v2()] interface and 547 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 548 */ 549 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 550 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 551 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 552 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 553 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 554 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 555 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 556 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 557 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 558 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 559 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 560 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 561 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 562 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 563 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 564 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 565 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 566 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 567 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 568 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 569 570 /* Reserved: 0x00F00000 */ 571 572 /* 573 ** CAPI3REF: Device Characteristics 574 ** 575 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 576 ** object returns an integer which is a vector of these 577 ** bit values expressing I/O characteristics of the mass storage 578 ** device that holds the file that the [sqlite3_io_methods] 579 ** refers to. 580 ** 581 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 582 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 583 ** mean that writes of blocks that are nnn bytes in size and 584 ** are aligned to an address which is an integer multiple of 585 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 586 ** that when data is appended to a file, the data is appended 587 ** first then the size of the file is extended, never the other 588 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 589 ** information is written to disk in the same order as calls 590 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 591 ** after reboot following a crash or power loss, the only bytes in a 592 ** file that were written at the application level might have changed 593 ** and that adjacent bytes, even bytes within the same sector are 594 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 595 ** flag indicates that a file cannot be deleted when open. The 596 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 597 ** read-only media and cannot be changed even by processes with 598 ** elevated privileges. 599 ** 600 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 601 ** filesystem supports doing multiple write operations atomically when those 602 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 603 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 604 */ 605 #define SQLITE_IOCAP_ATOMIC 0x00000001 606 #define SQLITE_IOCAP_ATOMIC512 0x00000002 607 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 608 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 609 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 610 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 611 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 612 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 613 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 614 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 615 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 616 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 617 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 618 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 619 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 620 621 /* 622 ** CAPI3REF: File Locking Levels 623 ** 624 ** SQLite uses one of these integer values as the second 625 ** argument to calls it makes to the xLock() and xUnlock() methods 626 ** of an [sqlite3_io_methods] object. 627 */ 628 #define SQLITE_LOCK_NONE 0 629 #define SQLITE_LOCK_SHARED 1 630 #define SQLITE_LOCK_RESERVED 2 631 #define SQLITE_LOCK_PENDING 3 632 #define SQLITE_LOCK_EXCLUSIVE 4 633 634 /* 635 ** CAPI3REF: Synchronization Type Flags 636 ** 637 ** When SQLite invokes the xSync() method of an 638 ** [sqlite3_io_methods] object it uses a combination of 639 ** these integer values as the second argument. 640 ** 641 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 642 ** sync operation only needs to flush data to mass storage. Inode 643 ** information need not be flushed. If the lower four bits of the flag 644 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 645 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 646 ** to use Mac OS X style fullsync instead of fsync(). 647 ** 648 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 649 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 650 ** settings. The [synchronous pragma] determines when calls to the 651 ** xSync VFS method occur and applies uniformly across all platforms. 652 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 653 ** energetic or rigorous or forceful the sync operations are and 654 ** only make a difference on Mac OSX for the default SQLite code. 655 ** (Third-party VFS implementations might also make the distinction 656 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 657 ** operating systems natively supported by SQLite, only Mac OSX 658 ** cares about the difference.) 659 */ 660 #define SQLITE_SYNC_NORMAL 0x00002 661 #define SQLITE_SYNC_FULL 0x00003 662 #define SQLITE_SYNC_DATAONLY 0x00010 663 664 /* 665 ** CAPI3REF: OS Interface Open File Handle 666 ** 667 ** An [sqlite3_file] object represents an open file in the 668 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 669 ** implementations will 670 ** want to subclass this object by appending additional fields 671 ** for their own use. The pMethods entry is a pointer to an 672 ** [sqlite3_io_methods] object that defines methods for performing 673 ** I/O operations on the open file. 674 */ 675 typedef struct sqlite3_file sqlite3_file; 676 struct sqlite3_file { 677 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 678 }; 679 680 /* 681 ** CAPI3REF: OS Interface File Virtual Methods Object 682 ** 683 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 684 ** [sqlite3_file] object (or, more commonly, a subclass of the 685 ** [sqlite3_file] object) with a pointer to an instance of this object. 686 ** This object defines the methods used to perform various operations 687 ** against the open file represented by the [sqlite3_file] object. 688 ** 689 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 690 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 691 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 692 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 693 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 694 ** to NULL. 695 ** 696 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 697 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 698 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 699 ** flag may be ORed in to indicate that only the data of the file 700 ** and not its inode needs to be synced. 701 ** 702 ** The integer values to xLock() and xUnlock() are one of 703 ** <ul> 704 ** <li> [SQLITE_LOCK_NONE], 705 ** <li> [SQLITE_LOCK_SHARED], 706 ** <li> [SQLITE_LOCK_RESERVED], 707 ** <li> [SQLITE_LOCK_PENDING], or 708 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 709 ** </ul> 710 ** xLock() increases the lock. xUnlock() decreases the lock. 711 ** The xCheckReservedLock() method checks whether any database connection, 712 ** either in this process or in some other process, is holding a RESERVED, 713 ** PENDING, or EXCLUSIVE lock on the file. It returns true 714 ** if such a lock exists and false otherwise. 715 ** 716 ** The xFileControl() method is a generic interface that allows custom 717 ** VFS implementations to directly control an open file using the 718 ** [sqlite3_file_control()] interface. The second "op" argument is an 719 ** integer opcode. The third argument is a generic pointer intended to 720 ** point to a structure that may contain arguments or space in which to 721 ** write return values. Potential uses for xFileControl() might be 722 ** functions to enable blocking locks with timeouts, to change the 723 ** locking strategy (for example to use dot-file locks), to inquire 724 ** about the status of a lock, or to break stale locks. The SQLite 725 ** core reserves all opcodes less than 100 for its own use. 726 ** A [file control opcodes | list of opcodes] less than 100 is available. 727 ** Applications that define a custom xFileControl method should use opcodes 728 ** greater than 100 to avoid conflicts. VFS implementations should 729 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 730 ** recognize. 731 ** 732 ** The xSectorSize() method returns the sector size of the 733 ** device that underlies the file. The sector size is the 734 ** minimum write that can be performed without disturbing 735 ** other bytes in the file. The xDeviceCharacteristics() 736 ** method returns a bit vector describing behaviors of the 737 ** underlying device: 738 ** 739 ** <ul> 740 ** <li> [SQLITE_IOCAP_ATOMIC] 741 ** <li> [SQLITE_IOCAP_ATOMIC512] 742 ** <li> [SQLITE_IOCAP_ATOMIC1K] 743 ** <li> [SQLITE_IOCAP_ATOMIC2K] 744 ** <li> [SQLITE_IOCAP_ATOMIC4K] 745 ** <li> [SQLITE_IOCAP_ATOMIC8K] 746 ** <li> [SQLITE_IOCAP_ATOMIC16K] 747 ** <li> [SQLITE_IOCAP_ATOMIC32K] 748 ** <li> [SQLITE_IOCAP_ATOMIC64K] 749 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 750 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 751 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 752 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 753 ** <li> [SQLITE_IOCAP_IMMUTABLE] 754 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 755 ** </ul> 756 ** 757 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 758 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 759 ** mean that writes of blocks that are nnn bytes in size and 760 ** are aligned to an address which is an integer multiple of 761 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 762 ** that when data is appended to a file, the data is appended 763 ** first then the size of the file is extended, never the other 764 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 765 ** information is written to disk in the same order as calls 766 ** to xWrite(). 767 ** 768 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 769 ** in the unread portions of the buffer with zeros. A VFS that 770 ** fails to zero-fill short reads might seem to work. However, 771 ** failure to zero-fill short reads will eventually lead to 772 ** database corruption. 773 */ 774 typedef struct sqlite3_io_methods sqlite3_io_methods; 775 struct sqlite3_io_methods { 776 int iVersion; 777 int (*xClose)(sqlite3_file*); 778 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 779 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 780 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 781 int (*xSync)(sqlite3_file*, int flags); 782 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 783 int (*xLock)(sqlite3_file*, int); 784 int (*xUnlock)(sqlite3_file*, int); 785 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 786 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 787 int (*xSectorSize)(sqlite3_file*); 788 int (*xDeviceCharacteristics)(sqlite3_file*); 789 /* Methods above are valid for version 1 */ 790 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 791 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 792 void (*xShmBarrier)(sqlite3_file*); 793 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 794 /* Methods above are valid for version 2 */ 795 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 796 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 797 /* Methods above are valid for version 3 */ 798 /* Additional methods may be added in future releases */ 799 }; 800 801 /* 802 ** CAPI3REF: Standard File Control Opcodes 803 ** KEYWORDS: {file control opcodes} {file control opcode} 804 ** 805 ** These integer constants are opcodes for the xFileControl method 806 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 807 ** interface. 808 ** 809 ** <ul> 810 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 811 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 812 ** opcode causes the xFileControl method to write the current state of 813 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 814 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 815 ** into an integer that the pArg argument points to. This capability 816 ** is used during testing and is only available when the SQLITE_TEST 817 ** compile-time option is used. 818 ** 819 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 820 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 821 ** layer a hint of how large the database file will grow to be during the 822 ** current transaction. This hint is not guaranteed to be accurate but it 823 ** is often close. The underlying VFS might choose to preallocate database 824 ** file space based on this hint in order to help writes to the database 825 ** file run faster. 826 ** 827 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 828 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 829 ** extends and truncates the database file in chunks of a size specified 830 ** by the user. The fourth argument to [sqlite3_file_control()] should 831 ** point to an integer (type int) containing the new chunk-size to use 832 ** for the nominated database. Allocating database file space in large 833 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 834 ** improve performance on some systems. 835 ** 836 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 837 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 838 ** to the [sqlite3_file] object associated with a particular database 839 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 840 ** 841 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 842 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 843 ** to the [sqlite3_file] object associated with the journal file (either 844 ** the [rollback journal] or the [write-ahead log]) for a particular database 845 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 846 ** 847 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 848 ** No longer in use. 849 ** 850 ** <li>[[SQLITE_FCNTL_SYNC]] 851 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 852 ** sent to the VFS immediately before the xSync method is invoked on a 853 ** database file descriptor. Or, if the xSync method is not invoked 854 ** because the user has configured SQLite with 855 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 856 ** of the xSync method. In most cases, the pointer argument passed with 857 ** this file-control is NULL. However, if the database file is being synced 858 ** as part of a multi-database commit, the argument points to a nul-terminated 859 ** string containing the transactions master-journal file name. VFSes that 860 ** do not need this signal should silently ignore this opcode. Applications 861 ** should not call [sqlite3_file_control()] with this opcode as doing so may 862 ** disrupt the operation of the specialized VFSes that do require it. 863 ** 864 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 865 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 866 ** and sent to the VFS after a transaction has been committed immediately 867 ** but before the database is unlocked. VFSes that do not need this signal 868 ** should silently ignore this opcode. Applications should not call 869 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 870 ** operation of the specialized VFSes that do require it. 871 ** 872 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 873 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 874 ** retry counts and intervals for certain disk I/O operations for the 875 ** windows [VFS] in order to provide robustness in the presence of 876 ** anti-virus programs. By default, the windows VFS will retry file read, 877 ** file write, and file delete operations up to 10 times, with a delay 878 ** of 25 milliseconds before the first retry and with the delay increasing 879 ** by an additional 25 milliseconds with each subsequent retry. This 880 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 881 ** to be adjusted. The values are changed for all database connections 882 ** within the same process. The argument is a pointer to an array of two 883 ** integers where the first integer is the new retry count and the second 884 ** integer is the delay. If either integer is negative, then the setting 885 ** is not changed but instead the prior value of that setting is written 886 ** into the array entry, allowing the current retry settings to be 887 ** interrogated. The zDbName parameter is ignored. 888 ** 889 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 890 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 891 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 892 ** write ahead log ([WAL file]) and shared memory 893 ** files used for transaction control 894 ** are automatically deleted when the latest connection to the database 895 ** closes. Setting persistent WAL mode causes those files to persist after 896 ** close. Persisting the files is useful when other processes that do not 897 ** have write permission on the directory containing the database file want 898 ** to read the database file, as the WAL and shared memory files must exist 899 ** in order for the database to be readable. The fourth parameter to 900 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 901 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 902 ** WAL mode. If the integer is -1, then it is overwritten with the current 903 ** WAL persistence setting. 904 ** 905 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 906 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 907 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 908 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 909 ** xDeviceCharacteristics methods. The fourth parameter to 910 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 911 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 912 ** mode. If the integer is -1, then it is overwritten with the current 913 ** zero-damage mode setting. 914 ** 915 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 916 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 917 ** a write transaction to indicate that, unless it is rolled back for some 918 ** reason, the entire database file will be overwritten by the current 919 ** transaction. This is used by VACUUM operations. 920 ** 921 ** <li>[[SQLITE_FCNTL_VFSNAME]] 922 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 923 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 924 ** final bottom-level VFS are written into memory obtained from 925 ** [sqlite3_malloc()] and the result is stored in the char* variable 926 ** that the fourth parameter of [sqlite3_file_control()] points to. 927 ** The caller is responsible for freeing the memory when done. As with 928 ** all file-control actions, there is no guarantee that this will actually 929 ** do anything. Callers should initialize the char* variable to a NULL 930 ** pointer in case this file-control is not implemented. This file-control 931 ** is intended for diagnostic use only. 932 ** 933 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 934 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 935 ** [VFSes] currently in use. ^(The argument X in 936 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 937 ** of type "[sqlite3_vfs] **". This opcodes will set *X 938 ** to a pointer to the top-level VFS.)^ 939 ** ^When there are multiple VFS shims in the stack, this opcode finds the 940 ** upper-most shim only. 941 ** 942 ** <li>[[SQLITE_FCNTL_PRAGMA]] 943 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 944 ** file control is sent to the open [sqlite3_file] object corresponding 945 ** to the database file to which the pragma statement refers. ^The argument 946 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 947 ** pointers to strings (char**) in which the second element of the array 948 ** is the name of the pragma and the third element is the argument to the 949 ** pragma or NULL if the pragma has no argument. ^The handler for an 950 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 951 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 952 ** or the equivalent and that string will become the result of the pragma or 953 ** the error message if the pragma fails. ^If the 954 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 955 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 956 ** file control returns [SQLITE_OK], then the parser assumes that the 957 ** VFS has handled the PRAGMA itself and the parser generates a no-op 958 ** prepared statement if result string is NULL, or that returns a copy 959 ** of the result string if the string is non-NULL. 960 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 961 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 962 ** that the VFS encountered an error while handling the [PRAGMA] and the 963 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 964 ** file control occurs at the beginning of pragma statement analysis and so 965 ** it is able to override built-in [PRAGMA] statements. 966 ** 967 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 968 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 969 ** file-control may be invoked by SQLite on the database file handle 970 ** shortly after it is opened in order to provide a custom VFS with access 971 ** to the connections busy-handler callback. The argument is of type (void **) 972 ** - an array of two (void *) values. The first (void *) actually points 973 ** to a function of type (int (*)(void *)). In order to invoke the connections 974 ** busy-handler, this function should be invoked with the second (void *) in 975 ** the array as the only argument. If it returns non-zero, then the operation 976 ** should be retried. If it returns zero, the custom VFS should abandon the 977 ** current operation. 978 ** 979 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 980 ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 981 ** to have SQLite generate a 982 ** temporary filename using the same algorithm that is followed to generate 983 ** temporary filenames for TEMP tables and other internal uses. The 984 ** argument should be a char** which will be filled with the filename 985 ** written into memory obtained from [sqlite3_malloc()]. The caller should 986 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 987 ** 988 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 989 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 990 ** maximum number of bytes that will be used for memory-mapped I/O. 991 ** The argument is a pointer to a value of type sqlite3_int64 that 992 ** is an advisory maximum number of bytes in the file to memory map. The 993 ** pointer is overwritten with the old value. The limit is not changed if 994 ** the value originally pointed to is negative, and so the current limit 995 ** can be queried by passing in a pointer to a negative number. This 996 ** file-control is used internally to implement [PRAGMA mmap_size]. 997 ** 998 ** <li>[[SQLITE_FCNTL_TRACE]] 999 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1000 ** to the VFS about what the higher layers of the SQLite stack are doing. 1001 ** This file control is used by some VFS activity tracing [shims]. 1002 ** The argument is a zero-terminated string. Higher layers in the 1003 ** SQLite stack may generate instances of this file control if 1004 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1005 ** 1006 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1007 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1008 ** pointer to an integer and it writes a boolean into that integer depending 1009 ** on whether or not the file has been renamed, moved, or deleted since it 1010 ** was first opened. 1011 ** 1012 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1013 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1014 ** underlying native file handle associated with a file handle. This file 1015 ** control interprets its argument as a pointer to a native file handle and 1016 ** writes the resulting value there. 1017 ** 1018 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1019 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1020 ** opcode causes the xFileControl method to swap the file handle with the one 1021 ** pointed to by the pArg argument. This capability is used during testing 1022 ** and only needs to be supported when SQLITE_TEST is defined. 1023 ** 1024 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1025 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1026 ** be advantageous to block on the next WAL lock if the lock is not immediately 1027 ** available. The WAL subsystem issues this signal during rare 1028 ** circumstances in order to fix a problem with priority inversion. 1029 ** Applications should <em>not</em> use this file-control. 1030 ** 1031 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 1032 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1033 ** VFS should return SQLITE_NOTFOUND for this opcode. 1034 ** 1035 ** <li>[[SQLITE_FCNTL_RBU]] 1036 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1037 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1038 ** this opcode. 1039 ** 1040 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1041 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1042 ** the file descriptor is placed in "batch write mode", which 1043 ** means all subsequent write operations will be deferred and done 1044 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1045 ** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1046 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1047 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1048 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1049 ** no VFS interface calls on the same [sqlite3_file] file descriptor 1050 ** except for calls to the xWrite method and the xFileControl method 1051 ** with [SQLITE_FCNTL_SIZE_HINT]. 1052 ** 1053 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1054 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1055 ** operations since the previous successful call to 1056 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1057 ** This file control returns [SQLITE_OK] if and only if the writes were 1058 ** all performed successfully and have been committed to persistent storage. 1059 ** ^Regardless of whether or not it is successful, this file control takes 1060 ** the file descriptor out of batch write mode so that all subsequent 1061 ** write operations are independent. 1062 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1063 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1064 ** 1065 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1066 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1067 ** operations since the previous successful call to 1068 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1069 ** ^This file control takes the file descriptor out of batch write mode 1070 ** so that all subsequent write operations are independent. 1071 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1072 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1073 ** 1074 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1075 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain 1076 ** a file lock using the xLock or xShmLock methods of the VFS to wait 1077 ** for up to M milliseconds before failing, where M is the single 1078 ** unsigned integer parameter. 1079 ** 1080 ** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1081 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1082 ** a database file. The argument is a pointer to a 32-bit unsigned integer. 1083 ** The "data version" for the pager is written into the pointer. The 1084 ** "data version" changes whenever any change occurs to the corresponding 1085 ** database file, either through SQL statements on the same database 1086 ** connection or through transactions committed by separate database 1087 ** connections possibly in other processes. The [sqlite3_total_changes()] 1088 ** interface can be used to find if any database on the connection has changed, 1089 ** but that interface responds to changes on TEMP as well as MAIN and does 1090 ** not provide a mechanism to detect changes to MAIN only. Also, the 1091 ** [sqlite3_total_changes()] interface responds to internal changes only and 1092 ** omits changes made by other database connections. The 1093 ** [PRAGMA data_version] command provide a mechanism to detect changes to 1094 ** a single attached database that occur due to other database connections, 1095 ** but omits changes implemented by the database connection on which it is 1096 ** called. This file control is the only mechanism to detect changes that 1097 ** happen either internally or externally and that are associated with 1098 ** a particular attached database. 1099 ** </ul> 1100 */ 1101 #define SQLITE_FCNTL_LOCKSTATE 1 1102 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1103 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1104 #define SQLITE_FCNTL_LAST_ERRNO 4 1105 #define SQLITE_FCNTL_SIZE_HINT 5 1106 #define SQLITE_FCNTL_CHUNK_SIZE 6 1107 #define SQLITE_FCNTL_FILE_POINTER 7 1108 #define SQLITE_FCNTL_SYNC_OMITTED 8 1109 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1110 #define SQLITE_FCNTL_PERSIST_WAL 10 1111 #define SQLITE_FCNTL_OVERWRITE 11 1112 #define SQLITE_FCNTL_VFSNAME 12 1113 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1114 #define SQLITE_FCNTL_PRAGMA 14 1115 #define SQLITE_FCNTL_BUSYHANDLER 15 1116 #define SQLITE_FCNTL_TEMPFILENAME 16 1117 #define SQLITE_FCNTL_MMAP_SIZE 18 1118 #define SQLITE_FCNTL_TRACE 19 1119 #define SQLITE_FCNTL_HAS_MOVED 20 1120 #define SQLITE_FCNTL_SYNC 21 1121 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1122 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1123 #define SQLITE_FCNTL_WAL_BLOCK 24 1124 #define SQLITE_FCNTL_ZIPVFS 25 1125 #define SQLITE_FCNTL_RBU 26 1126 #define SQLITE_FCNTL_VFS_POINTER 27 1127 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1128 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1129 #define SQLITE_FCNTL_PDB 30 1130 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1131 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1132 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1133 #define SQLITE_FCNTL_LOCK_TIMEOUT 34 1134 #define SQLITE_FCNTL_DATA_VERSION 35 1135 1136 /* deprecated names */ 1137 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1138 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1139 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1140 1141 1142 /* 1143 ** CAPI3REF: Mutex Handle 1144 ** 1145 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1146 ** abstract type for a mutex object. The SQLite core never looks 1147 ** at the internal representation of an [sqlite3_mutex]. It only 1148 ** deals with pointers to the [sqlite3_mutex] object. 1149 ** 1150 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1151 */ 1152 typedef struct sqlite3_mutex sqlite3_mutex; 1153 1154 /* 1155 ** CAPI3REF: Loadable Extension Thunk 1156 ** 1157 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1158 ** the third parameter to entry points of [loadable extensions]. This 1159 ** structure must be typedefed in order to work around compiler warnings 1160 ** on some platforms. 1161 */ 1162 typedef struct sqlite3_api_routines sqlite3_api_routines; 1163 1164 /* 1165 ** CAPI3REF: OS Interface Object 1166 ** 1167 ** An instance of the sqlite3_vfs object defines the interface between 1168 ** the SQLite core and the underlying operating system. The "vfs" 1169 ** in the name of the object stands for "virtual file system". See 1170 ** the [VFS | VFS documentation] for further information. 1171 ** 1172 ** The VFS interface is sometimes extended by adding new methods onto 1173 ** the end. Each time such an extension occurs, the iVersion field 1174 ** is incremented. The iVersion value started out as 1 in 1175 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1176 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1177 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1178 ** may be appended to the sqlite3_vfs object and the iVersion value 1179 ** may increase again in future versions of SQLite. 1180 ** Note that the structure 1181 ** of the sqlite3_vfs object changes in the transition from 1182 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1183 ** and yet the iVersion field was not modified. 1184 ** 1185 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1186 ** structure used by this VFS. mxPathname is the maximum length of 1187 ** a pathname in this VFS. 1188 ** 1189 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1190 ** the pNext pointer. The [sqlite3_vfs_register()] 1191 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1192 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1193 ** searches the list. Neither the application code nor the VFS 1194 ** implementation should use the pNext pointer. 1195 ** 1196 ** The pNext field is the only field in the sqlite3_vfs 1197 ** structure that SQLite will ever modify. SQLite will only access 1198 ** or modify this field while holding a particular static mutex. 1199 ** The application should never modify anything within the sqlite3_vfs 1200 ** object once the object has been registered. 1201 ** 1202 ** The zName field holds the name of the VFS module. The name must 1203 ** be unique across all VFS modules. 1204 ** 1205 ** [[sqlite3_vfs.xOpen]] 1206 ** ^SQLite guarantees that the zFilename parameter to xOpen 1207 ** is either a NULL pointer or string obtained 1208 ** from xFullPathname() with an optional suffix added. 1209 ** ^If a suffix is added to the zFilename parameter, it will 1210 ** consist of a single "-" character followed by no more than 1211 ** 11 alphanumeric and/or "-" characters. 1212 ** ^SQLite further guarantees that 1213 ** the string will be valid and unchanged until xClose() is 1214 ** called. Because of the previous sentence, 1215 ** the [sqlite3_file] can safely store a pointer to the 1216 ** filename if it needs to remember the filename for some reason. 1217 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1218 ** must invent its own temporary name for the file. ^Whenever the 1219 ** xFilename parameter is NULL it will also be the case that the 1220 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1221 ** 1222 ** The flags argument to xOpen() includes all bits set in 1223 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1224 ** or [sqlite3_open16()] is used, then flags includes at least 1225 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1226 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1227 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1228 ** 1229 ** ^(SQLite will also add one of the following flags to the xOpen() 1230 ** call, depending on the object being opened: 1231 ** 1232 ** <ul> 1233 ** <li> [SQLITE_OPEN_MAIN_DB] 1234 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1235 ** <li> [SQLITE_OPEN_TEMP_DB] 1236 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1237 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1238 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1239 ** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1240 ** <li> [SQLITE_OPEN_WAL] 1241 ** </ul>)^ 1242 ** 1243 ** The file I/O implementation can use the object type flags to 1244 ** change the way it deals with files. For example, an application 1245 ** that does not care about crash recovery or rollback might make 1246 ** the open of a journal file a no-op. Writes to this journal would 1247 ** also be no-ops, and any attempt to read the journal would return 1248 ** SQLITE_IOERR. Or the implementation might recognize that a database 1249 ** file will be doing page-aligned sector reads and writes in a random 1250 ** order and set up its I/O subsystem accordingly. 1251 ** 1252 ** SQLite might also add one of the following flags to the xOpen method: 1253 ** 1254 ** <ul> 1255 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1256 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1257 ** </ul> 1258 ** 1259 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1260 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1261 ** will be set for TEMP databases and their journals, transient 1262 ** databases, and subjournals. 1263 ** 1264 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1265 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1266 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1267 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1268 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1269 ** be created, and that it is an error if it already exists. 1270 ** It is <i>not</i> used to indicate the file should be opened 1271 ** for exclusive access. 1272 ** 1273 ** ^At least szOsFile bytes of memory are allocated by SQLite 1274 ** to hold the [sqlite3_file] structure passed as the third 1275 ** argument to xOpen. The xOpen method does not have to 1276 ** allocate the structure; it should just fill it in. Note that 1277 ** the xOpen method must set the sqlite3_file.pMethods to either 1278 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1279 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1280 ** element will be valid after xOpen returns regardless of the success 1281 ** or failure of the xOpen call. 1282 ** 1283 ** [[sqlite3_vfs.xAccess]] 1284 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1285 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1286 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1287 ** to test whether a file is at least readable. The file can be a 1288 ** directory. 1289 ** 1290 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1291 ** output buffer xFullPathname. The exact size of the output buffer 1292 ** is also passed as a parameter to both methods. If the output buffer 1293 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1294 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1295 ** to prevent this by setting mxPathname to a sufficiently large value. 1296 ** 1297 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1298 ** interfaces are not strictly a part of the filesystem, but they are 1299 ** included in the VFS structure for completeness. 1300 ** The xRandomness() function attempts to return nBytes bytes 1301 ** of good-quality randomness into zOut. The return value is 1302 ** the actual number of bytes of randomness obtained. 1303 ** The xSleep() method causes the calling thread to sleep for at 1304 ** least the number of microseconds given. ^The xCurrentTime() 1305 ** method returns a Julian Day Number for the current date and time as 1306 ** a floating point value. 1307 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1308 ** Day Number multiplied by 86400000 (the number of milliseconds in 1309 ** a 24-hour day). 1310 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1311 ** date and time if that method is available (if iVersion is 2 or 1312 ** greater and the function pointer is not NULL) and will fall back 1313 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1314 ** 1315 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1316 ** are not used by the SQLite core. These optional interfaces are provided 1317 ** by some VFSes to facilitate testing of the VFS code. By overriding 1318 ** system calls with functions under its control, a test program can 1319 ** simulate faults and error conditions that would otherwise be difficult 1320 ** or impossible to induce. The set of system calls that can be overridden 1321 ** varies from one VFS to another, and from one version of the same VFS to the 1322 ** next. Applications that use these interfaces must be prepared for any 1323 ** or all of these interfaces to be NULL or for their behavior to change 1324 ** from one release to the next. Applications must not attempt to access 1325 ** any of these methods if the iVersion of the VFS is less than 3. 1326 */ 1327 typedef struct sqlite3_vfs sqlite3_vfs; 1328 typedef void (*sqlite3_syscall_ptr)(void); 1329 struct sqlite3_vfs { 1330 int iVersion; /* Structure version number (currently 3) */ 1331 int szOsFile; /* Size of subclassed sqlite3_file */ 1332 int mxPathname; /* Maximum file pathname length */ 1333 sqlite3_vfs *pNext; /* Next registered VFS */ 1334 const char *zName; /* Name of this virtual file system */ 1335 void *pAppData; /* Pointer to application-specific data */ 1336 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1337 int flags, int *pOutFlags); 1338 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1339 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1340 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1341 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1342 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1343 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1344 void (*xDlClose)(sqlite3_vfs*, void*); 1345 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1346 int (*xSleep)(sqlite3_vfs*, int microseconds); 1347 int (*xCurrentTime)(sqlite3_vfs*, double*); 1348 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1349 /* 1350 ** The methods above are in version 1 of the sqlite_vfs object 1351 ** definition. Those that follow are added in version 2 or later 1352 */ 1353 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1354 /* 1355 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1356 ** Those below are for version 3 and greater. 1357 */ 1358 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1359 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1360 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1361 /* 1362 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1363 ** New fields may be appended in future versions. The iVersion 1364 ** value will increment whenever this happens. 1365 */ 1366 }; 1367 1368 /* 1369 ** CAPI3REF: Flags for the xAccess VFS method 1370 ** 1371 ** These integer constants can be used as the third parameter to 1372 ** the xAccess method of an [sqlite3_vfs] object. They determine 1373 ** what kind of permissions the xAccess method is looking for. 1374 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1375 ** simply checks whether the file exists. 1376 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1377 ** checks whether the named directory is both readable and writable 1378 ** (in other words, if files can be added, removed, and renamed within 1379 ** the directory). 1380 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1381 ** [temp_store_directory pragma], though this could change in a future 1382 ** release of SQLite. 1383 ** With SQLITE_ACCESS_READ, the xAccess method 1384 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1385 ** currently unused, though it might be used in a future release of 1386 ** SQLite. 1387 */ 1388 #define SQLITE_ACCESS_EXISTS 0 1389 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1390 #define SQLITE_ACCESS_READ 2 /* Unused */ 1391 1392 /* 1393 ** CAPI3REF: Flags for the xShmLock VFS method 1394 ** 1395 ** These integer constants define the various locking operations 1396 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1397 ** following are the only legal combinations of flags to the 1398 ** xShmLock method: 1399 ** 1400 ** <ul> 1401 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1402 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1403 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1404 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1405 ** </ul> 1406 ** 1407 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1408 ** was given on the corresponding lock. 1409 ** 1410 ** The xShmLock method can transition between unlocked and SHARED or 1411 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1412 ** and EXCLUSIVE. 1413 */ 1414 #define SQLITE_SHM_UNLOCK 1 1415 #define SQLITE_SHM_LOCK 2 1416 #define SQLITE_SHM_SHARED 4 1417 #define SQLITE_SHM_EXCLUSIVE 8 1418 1419 /* 1420 ** CAPI3REF: Maximum xShmLock index 1421 ** 1422 ** The xShmLock method on [sqlite3_io_methods] may use values 1423 ** between 0 and this upper bound as its "offset" argument. 1424 ** The SQLite core will never attempt to acquire or release a 1425 ** lock outside of this range 1426 */ 1427 #define SQLITE_SHM_NLOCK 8 1428 1429 1430 /* 1431 ** CAPI3REF: Initialize The SQLite Library 1432 ** 1433 ** ^The sqlite3_initialize() routine initializes the 1434 ** SQLite library. ^The sqlite3_shutdown() routine 1435 ** deallocates any resources that were allocated by sqlite3_initialize(). 1436 ** These routines are designed to aid in process initialization and 1437 ** shutdown on embedded systems. Workstation applications using 1438 ** SQLite normally do not need to invoke either of these routines. 1439 ** 1440 ** A call to sqlite3_initialize() is an "effective" call if it is 1441 ** the first time sqlite3_initialize() is invoked during the lifetime of 1442 ** the process, or if it is the first time sqlite3_initialize() is invoked 1443 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1444 ** of sqlite3_initialize() does any initialization. All other calls 1445 ** are harmless no-ops.)^ 1446 ** 1447 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1448 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1449 ** an effective call to sqlite3_shutdown() does any deinitialization. 1450 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1451 ** 1452 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1453 ** is not. The sqlite3_shutdown() interface must only be called from a 1454 ** single thread. All open [database connections] must be closed and all 1455 ** other SQLite resources must be deallocated prior to invoking 1456 ** sqlite3_shutdown(). 1457 ** 1458 ** Among other things, ^sqlite3_initialize() will invoke 1459 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1460 ** will invoke sqlite3_os_end(). 1461 ** 1462 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1463 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1464 ** the library (perhaps it is unable to allocate a needed resource such 1465 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1466 ** 1467 ** ^The sqlite3_initialize() routine is called internally by many other 1468 ** SQLite interfaces so that an application usually does not need to 1469 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1470 ** calls sqlite3_initialize() so the SQLite library will be automatically 1471 ** initialized when [sqlite3_open()] is called if it has not be initialized 1472 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1473 ** compile-time option, then the automatic calls to sqlite3_initialize() 1474 ** are omitted and the application must call sqlite3_initialize() directly 1475 ** prior to using any other SQLite interface. For maximum portability, 1476 ** it is recommended that applications always invoke sqlite3_initialize() 1477 ** directly prior to using any other SQLite interface. Future releases 1478 ** of SQLite may require this. In other words, the behavior exhibited 1479 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1480 ** default behavior in some future release of SQLite. 1481 ** 1482 ** The sqlite3_os_init() routine does operating-system specific 1483 ** initialization of the SQLite library. The sqlite3_os_end() 1484 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1485 ** performed by these routines include allocation or deallocation 1486 ** of static resources, initialization of global variables, 1487 ** setting up a default [sqlite3_vfs] module, or setting up 1488 ** a default configuration using [sqlite3_config()]. 1489 ** 1490 ** The application should never invoke either sqlite3_os_init() 1491 ** or sqlite3_os_end() directly. The application should only invoke 1492 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1493 ** interface is called automatically by sqlite3_initialize() and 1494 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1495 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1496 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1497 ** When [custom builds | built for other platforms] 1498 ** (using the [SQLITE_OS_OTHER=1] compile-time 1499 ** option) the application must supply a suitable implementation for 1500 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1501 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1502 ** must return [SQLITE_OK] on success and some other [error code] upon 1503 ** failure. 1504 */ 1505 SQLITE_API int sqlite3_initialize(void); 1506 SQLITE_API int sqlite3_shutdown(void); 1507 SQLITE_API int sqlite3_os_init(void); 1508 SQLITE_API int sqlite3_os_end(void); 1509 1510 /* 1511 ** CAPI3REF: Configuring The SQLite Library 1512 ** 1513 ** The sqlite3_config() interface is used to make global configuration 1514 ** changes to SQLite in order to tune SQLite to the specific needs of 1515 ** the application. The default configuration is recommended for most 1516 ** applications and so this routine is usually not necessary. It is 1517 ** provided to support rare applications with unusual needs. 1518 ** 1519 ** <b>The sqlite3_config() interface is not threadsafe. The application 1520 ** must ensure that no other SQLite interfaces are invoked by other 1521 ** threads while sqlite3_config() is running.</b> 1522 ** 1523 ** The sqlite3_config() interface 1524 ** may only be invoked prior to library initialization using 1525 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1526 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1527 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1528 ** Note, however, that ^sqlite3_config() can be called as part of the 1529 ** implementation of an application-defined [sqlite3_os_init()]. 1530 ** 1531 ** The first argument to sqlite3_config() is an integer 1532 ** [configuration option] that determines 1533 ** what property of SQLite is to be configured. Subsequent arguments 1534 ** vary depending on the [configuration option] 1535 ** in the first argument. 1536 ** 1537 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1538 ** ^If the option is unknown or SQLite is unable to set the option 1539 ** then this routine returns a non-zero [error code]. 1540 */ 1541 SQLITE_API int sqlite3_config(int, ...); 1542 1543 /* 1544 ** CAPI3REF: Configure database connections 1545 ** METHOD: sqlite3 1546 ** 1547 ** The sqlite3_db_config() interface is used to make configuration 1548 ** changes to a [database connection]. The interface is similar to 1549 ** [sqlite3_config()] except that the changes apply to a single 1550 ** [database connection] (specified in the first argument). 1551 ** 1552 ** The second argument to sqlite3_db_config(D,V,...) is the 1553 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1554 ** that indicates what aspect of the [database connection] is being configured. 1555 ** Subsequent arguments vary depending on the configuration verb. 1556 ** 1557 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1558 ** the call is considered successful. 1559 */ 1560 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1561 1562 /* 1563 ** CAPI3REF: Memory Allocation Routines 1564 ** 1565 ** An instance of this object defines the interface between SQLite 1566 ** and low-level memory allocation routines. 1567 ** 1568 ** This object is used in only one place in the SQLite interface. 1569 ** A pointer to an instance of this object is the argument to 1570 ** [sqlite3_config()] when the configuration option is 1571 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1572 ** By creating an instance of this object 1573 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1574 ** during configuration, an application can specify an alternative 1575 ** memory allocation subsystem for SQLite to use for all of its 1576 ** dynamic memory needs. 1577 ** 1578 ** Note that SQLite comes with several [built-in memory allocators] 1579 ** that are perfectly adequate for the overwhelming majority of applications 1580 ** and that this object is only useful to a tiny minority of applications 1581 ** with specialized memory allocation requirements. This object is 1582 ** also used during testing of SQLite in order to specify an alternative 1583 ** memory allocator that simulates memory out-of-memory conditions in 1584 ** order to verify that SQLite recovers gracefully from such 1585 ** conditions. 1586 ** 1587 ** The xMalloc, xRealloc, and xFree methods must work like the 1588 ** malloc(), realloc() and free() functions from the standard C library. 1589 ** ^SQLite guarantees that the second argument to 1590 ** xRealloc is always a value returned by a prior call to xRoundup. 1591 ** 1592 ** xSize should return the allocated size of a memory allocation 1593 ** previously obtained from xMalloc or xRealloc. The allocated size 1594 ** is always at least as big as the requested size but may be larger. 1595 ** 1596 ** The xRoundup method returns what would be the allocated size of 1597 ** a memory allocation given a particular requested size. Most memory 1598 ** allocators round up memory allocations at least to the next multiple 1599 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1600 ** Every memory allocation request coming in through [sqlite3_malloc()] 1601 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1602 ** that causes the corresponding memory allocation to fail. 1603 ** 1604 ** The xInit method initializes the memory allocator. For example, 1605 ** it might allocate any require mutexes or initialize internal data 1606 ** structures. The xShutdown method is invoked (indirectly) by 1607 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1608 ** by xInit. The pAppData pointer is used as the only parameter to 1609 ** xInit and xShutdown. 1610 ** 1611 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1612 ** the xInit method, so the xInit method need not be threadsafe. The 1613 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1614 ** not need to be threadsafe either. For all other methods, SQLite 1615 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1616 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1617 ** it is by default) and so the methods are automatically serialized. 1618 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1619 ** methods must be threadsafe or else make their own arrangements for 1620 ** serialization. 1621 ** 1622 ** SQLite will never invoke xInit() more than once without an intervening 1623 ** call to xShutdown(). 1624 */ 1625 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1626 struct sqlite3_mem_methods { 1627 void *(*xMalloc)(int); /* Memory allocation function */ 1628 void (*xFree)(void*); /* Free a prior allocation */ 1629 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1630 int (*xSize)(void*); /* Return the size of an allocation */ 1631 int (*xRoundup)(int); /* Round up request size to allocation size */ 1632 int (*xInit)(void*); /* Initialize the memory allocator */ 1633 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1634 void *pAppData; /* Argument to xInit() and xShutdown() */ 1635 }; 1636 1637 /* 1638 ** CAPI3REF: Configuration Options 1639 ** KEYWORDS: {configuration option} 1640 ** 1641 ** These constants are the available integer configuration options that 1642 ** can be passed as the first argument to the [sqlite3_config()] interface. 1643 ** 1644 ** New configuration options may be added in future releases of SQLite. 1645 ** Existing configuration options might be discontinued. Applications 1646 ** should check the return code from [sqlite3_config()] to make sure that 1647 ** the call worked. The [sqlite3_config()] interface will return a 1648 ** non-zero [error code] if a discontinued or unsupported configuration option 1649 ** is invoked. 1650 ** 1651 ** <dl> 1652 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1653 ** <dd>There are no arguments to this option. ^This option sets the 1654 ** [threading mode] to Single-thread. In other words, it disables 1655 ** all mutexing and puts SQLite into a mode where it can only be used 1656 ** by a single thread. ^If SQLite is compiled with 1657 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1658 ** it is not possible to change the [threading mode] from its default 1659 ** value of Single-thread and so [sqlite3_config()] will return 1660 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1661 ** configuration option.</dd> 1662 ** 1663 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1664 ** <dd>There are no arguments to this option. ^This option sets the 1665 ** [threading mode] to Multi-thread. In other words, it disables 1666 ** mutexing on [database connection] and [prepared statement] objects. 1667 ** The application is responsible for serializing access to 1668 ** [database connections] and [prepared statements]. But other mutexes 1669 ** are enabled so that SQLite will be safe to use in a multi-threaded 1670 ** environment as long as no two threads attempt to use the same 1671 ** [database connection] at the same time. ^If SQLite is compiled with 1672 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1673 ** it is not possible to set the Multi-thread [threading mode] and 1674 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1675 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1676 ** 1677 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1678 ** <dd>There are no arguments to this option. ^This option sets the 1679 ** [threading mode] to Serialized. In other words, this option enables 1680 ** all mutexes including the recursive 1681 ** mutexes on [database connection] and [prepared statement] objects. 1682 ** In this mode (which is the default when SQLite is compiled with 1683 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1684 ** to [database connections] and [prepared statements] so that the 1685 ** application is free to use the same [database connection] or the 1686 ** same [prepared statement] in different threads at the same time. 1687 ** ^If SQLite is compiled with 1688 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1689 ** it is not possible to set the Serialized [threading mode] and 1690 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1691 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1692 ** 1693 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1694 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1695 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1696 ** The argument specifies 1697 ** alternative low-level memory allocation routines to be used in place of 1698 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1699 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1700 ** before the [sqlite3_config()] call returns.</dd> 1701 ** 1702 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1703 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1704 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1705 ** The [sqlite3_mem_methods] 1706 ** structure is filled with the currently defined memory allocation routines.)^ 1707 ** This option can be used to overload the default memory allocation 1708 ** routines with a wrapper that simulations memory allocation failure or 1709 ** tracks memory usage, for example. </dd> 1710 ** 1711 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1712 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1713 ** type int, interpreted as a boolean, which if true provides a hint to 1714 ** SQLite that it should avoid large memory allocations if possible. 1715 ** SQLite will run faster if it is free to make large memory allocations, 1716 ** but some application might prefer to run slower in exchange for 1717 ** guarantees about memory fragmentation that are possible if large 1718 ** allocations are avoided. This hint is normally off. 1719 ** </dd> 1720 ** 1721 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1722 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1723 ** interpreted as a boolean, which enables or disables the collection of 1724 ** memory allocation statistics. ^(When memory allocation statistics are 1725 ** disabled, the following SQLite interfaces become non-operational: 1726 ** <ul> 1727 ** <li> [sqlite3_memory_used()] 1728 ** <li> [sqlite3_memory_highwater()] 1729 ** <li> [sqlite3_soft_heap_limit64()] 1730 ** <li> [sqlite3_status64()] 1731 ** </ul>)^ 1732 ** ^Memory allocation statistics are enabled by default unless SQLite is 1733 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1734 ** allocation statistics are disabled by default. 1735 ** </dd> 1736 ** 1737 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1738 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1739 ** </dd> 1740 ** 1741 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1742 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1743 ** that SQLite can use for the database page cache with the default page 1744 ** cache implementation. 1745 ** This configuration option is a no-op if an application-define page 1746 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1747 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1748 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1749 ** and the number of cache lines (N). 1750 ** The sz argument should be the size of the largest database page 1751 ** (a power of two between 512 and 65536) plus some extra bytes for each 1752 ** page header. ^The number of extra bytes needed by the page header 1753 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1754 ** ^It is harmless, apart from the wasted memory, 1755 ** for the sz parameter to be larger than necessary. The pMem 1756 ** argument must be either a NULL pointer or a pointer to an 8-byte 1757 ** aligned block of memory of at least sz*N bytes, otherwise 1758 ** subsequent behavior is undefined. 1759 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1760 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1761 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1762 ** is exhausted. 1763 ** ^If pMem is NULL and N is non-zero, then each database connection 1764 ** does an initial bulk allocation for page cache memory 1765 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1766 ** of -1024*N bytes if N is negative, . ^If additional 1767 ** page cache memory is needed beyond what is provided by the initial 1768 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1769 ** additional cache line. </dd> 1770 ** 1771 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1772 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1773 ** that SQLite will use for all of its dynamic memory allocation needs 1774 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1775 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1776 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1777 ** [SQLITE_ERROR] if invoked otherwise. 1778 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1779 ** An 8-byte aligned pointer to the memory, 1780 ** the number of bytes in the memory buffer, and the minimum allocation size. 1781 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1782 ** to using its default memory allocator (the system malloc() implementation), 1783 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1784 ** memory pointer is not NULL then the alternative memory 1785 ** allocator is engaged to handle all of SQLites memory allocation needs. 1786 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1787 ** boundary or subsequent behavior of SQLite will be undefined. 1788 ** The minimum allocation size is capped at 2**12. Reasonable values 1789 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1790 ** 1791 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1792 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1793 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1794 ** The argument specifies alternative low-level mutex routines to be used 1795 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1796 ** the content of the [sqlite3_mutex_methods] structure before the call to 1797 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1798 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1799 ** the entire mutexing subsystem is omitted from the build and hence calls to 1800 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1801 ** return [SQLITE_ERROR].</dd> 1802 ** 1803 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1804 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1805 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1806 ** [sqlite3_mutex_methods] 1807 ** structure is filled with the currently defined mutex routines.)^ 1808 ** This option can be used to overload the default mutex allocation 1809 ** routines with a wrapper used to track mutex usage for performance 1810 ** profiling or testing, for example. ^If SQLite is compiled with 1811 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1812 ** the entire mutexing subsystem is omitted from the build and hence calls to 1813 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1814 ** return [SQLITE_ERROR].</dd> 1815 ** 1816 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1817 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1818 ** the default size of lookaside memory on each [database connection]. 1819 ** The first argument is the 1820 ** size of each lookaside buffer slot and the second is the number of 1821 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1822 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1823 ** option to [sqlite3_db_config()] can be used to change the lookaside 1824 ** configuration on individual connections.)^ </dd> 1825 ** 1826 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1827 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1828 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1829 ** the interface to a custom page cache implementation.)^ 1830 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1831 ** 1832 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1833 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1834 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1835 ** the current page cache implementation into that object.)^ </dd> 1836 ** 1837 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1838 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1839 ** global [error log]. 1840 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1841 ** function with a call signature of void(*)(void*,int,const char*), 1842 ** and a pointer to void. ^If the function pointer is not NULL, it is 1843 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1844 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1845 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1846 ** passed through as the first parameter to the application-defined logger 1847 ** function whenever that function is invoked. ^The second parameter to 1848 ** the logger function is a copy of the first parameter to the corresponding 1849 ** [sqlite3_log()] call and is intended to be a [result code] or an 1850 ** [extended result code]. ^The third parameter passed to the logger is 1851 ** log message after formatting via [sqlite3_snprintf()]. 1852 ** The SQLite logging interface is not reentrant; the logger function 1853 ** supplied by the application must not invoke any SQLite interface. 1854 ** In a multi-threaded application, the application-defined logger 1855 ** function must be threadsafe. </dd> 1856 ** 1857 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1858 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1859 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1860 ** then URI handling is globally disabled.)^ ^If URI handling is globally 1861 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1862 ** [sqlite3_open16()] or 1863 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1864 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1865 ** connection is opened. ^If it is globally disabled, filenames are 1866 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1867 ** database connection is opened. ^(By default, URI handling is globally 1868 ** disabled. The default value may be changed by compiling with the 1869 ** [SQLITE_USE_URI] symbol defined.)^ 1870 ** 1871 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1872 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1873 ** argument which is interpreted as a boolean in order to enable or disable 1874 ** the use of covering indices for full table scans in the query optimizer. 1875 ** ^The default setting is determined 1876 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1877 ** if that compile-time option is omitted. 1878 ** The ability to disable the use of covering indices for full table scans 1879 ** is because some incorrectly coded legacy applications might malfunction 1880 ** when the optimization is enabled. Providing the ability to 1881 ** disable the optimization allows the older, buggy application code to work 1882 ** without change even with newer versions of SQLite. 1883 ** 1884 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1885 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1886 ** <dd> These options are obsolete and should not be used by new code. 1887 ** They are retained for backwards compatibility but are now no-ops. 1888 ** </dd> 1889 ** 1890 ** [[SQLITE_CONFIG_SQLLOG]] 1891 ** <dt>SQLITE_CONFIG_SQLLOG 1892 ** <dd>This option is only available if sqlite is compiled with the 1893 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1894 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1895 ** The second should be of type (void*). The callback is invoked by the library 1896 ** in three separate circumstances, identified by the value passed as the 1897 ** fourth parameter. If the fourth parameter is 0, then the database connection 1898 ** passed as the second argument has just been opened. The third argument 1899 ** points to a buffer containing the name of the main database file. If the 1900 ** fourth parameter is 1, then the SQL statement that the third parameter 1901 ** points to has just been executed. Or, if the fourth parameter is 2, then 1902 ** the connection being passed as the second parameter is being closed. The 1903 ** third parameter is passed NULL In this case. An example of using this 1904 ** configuration option can be seen in the "test_sqllog.c" source file in 1905 ** the canonical SQLite source tree.</dd> 1906 ** 1907 ** [[SQLITE_CONFIG_MMAP_SIZE]] 1908 ** <dt>SQLITE_CONFIG_MMAP_SIZE 1909 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1910 ** that are the default mmap size limit (the default setting for 1911 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1912 ** ^The default setting can be overridden by each database connection using 1913 ** either the [PRAGMA mmap_size] command, or by using the 1914 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1915 ** will be silently truncated if necessary so that it does not exceed the 1916 ** compile-time maximum mmap size set by the 1917 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1918 ** ^If either argument to this option is negative, then that argument is 1919 ** changed to its compile-time default. 1920 ** 1921 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1922 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1923 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1924 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1925 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1926 ** that specifies the maximum size of the created heap. 1927 ** 1928 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1929 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1930 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1931 ** is a pointer to an integer and writes into that integer the number of extra 1932 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1933 ** The amount of extra space required can change depending on the compiler, 1934 ** target platform, and SQLite version. 1935 ** 1936 ** [[SQLITE_CONFIG_PMASZ]] 1937 ** <dt>SQLITE_CONFIG_PMASZ 1938 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1939 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1940 ** sorter to that integer. The default minimum PMA Size is set by the 1941 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1942 ** to help with sort operations when multithreaded sorting 1943 ** is enabled (using the [PRAGMA threads] command) and the amount of content 1944 ** to be sorted exceeds the page size times the minimum of the 1945 ** [PRAGMA cache_size] setting and this value. 1946 ** 1947 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1948 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1949 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1950 ** becomes the [statement journal] spill-to-disk threshold. 1951 ** [Statement journals] are held in memory until their size (in bytes) 1952 ** exceeds this threshold, at which point they are written to disk. 1953 ** Or if the threshold is -1, statement journals are always held 1954 ** exclusively in memory. 1955 ** Since many statement journals never become large, setting the spill 1956 ** threshold to a value such as 64KiB can greatly reduce the amount of 1957 ** I/O required to support statement rollback. 1958 ** The default value for this setting is controlled by the 1959 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 1960 ** 1961 ** [[SQLITE_CONFIG_SORTERREF_SIZE]] 1962 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE 1963 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 1964 ** of type (int) - the new value of the sorter-reference size threshold. 1965 ** Usually, when SQLite uses an external sort to order records according 1966 ** to an ORDER BY clause, all fields required by the caller are present in the 1967 ** sorted records. However, if SQLite determines based on the declared type 1968 ** of a table column that its values are likely to be very large - larger 1969 ** than the configured sorter-reference size threshold - then a reference 1970 ** is stored in each sorted record and the required column values loaded 1971 ** from the database as records are returned in sorted order. The default 1972 ** value for this option is to never use this optimization. Specifying a 1973 ** negative value for this option restores the default behaviour. 1974 ** This option is only available if SQLite is compiled with the 1975 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 1976 ** </dl> 1977 */ 1978 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1979 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1980 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1981 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1982 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1983 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 1984 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1985 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1986 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1987 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1988 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1989 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1990 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1991 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1992 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1993 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1994 #define SQLITE_CONFIG_URI 17 /* int */ 1995 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1996 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1997 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1998 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1999 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2000 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2001 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2002 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2003 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2004 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2005 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2006 2007 /* 2008 ** CAPI3REF: Database Connection Configuration Options 2009 ** 2010 ** These constants are the available integer configuration options that 2011 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 2012 ** 2013 ** New configuration options may be added in future releases of SQLite. 2014 ** Existing configuration options might be discontinued. Applications 2015 ** should check the return code from [sqlite3_db_config()] to make sure that 2016 ** the call worked. ^The [sqlite3_db_config()] interface will return a 2017 ** non-zero [error code] if a discontinued or unsupported configuration option 2018 ** is invoked. 2019 ** 2020 ** <dl> 2021 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2022 ** <dd> ^This option takes three additional arguments that determine the 2023 ** [lookaside memory allocator] configuration for the [database connection]. 2024 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2025 ** pointer to a memory buffer to use for lookaside memory. 2026 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2027 ** may be NULL in which case SQLite will allocate the 2028 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2029 ** size of each lookaside buffer slot. ^The third argument is the number of 2030 ** slots. The size of the buffer in the first argument must be greater than 2031 ** or equal to the product of the second and third arguments. The buffer 2032 ** must be aligned to an 8-byte boundary. ^If the second argument to 2033 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2034 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2035 ** configuration for a database connection can only be changed when that 2036 ** connection is not currently using lookaside memory, or in other words 2037 ** when the "current value" returned by 2038 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2039 ** Any attempt to change the lookaside memory configuration when lookaside 2040 ** memory is in use leaves the configuration unchanged and returns 2041 ** [SQLITE_BUSY].)^</dd> 2042 ** 2043 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2044 ** <dd> ^This option is used to enable or disable the enforcement of 2045 ** [foreign key constraints]. There should be two additional arguments. 2046 ** The first argument is an integer which is 0 to disable FK enforcement, 2047 ** positive to enable FK enforcement or negative to leave FK enforcement 2048 ** unchanged. The second parameter is a pointer to an integer into which 2049 ** is written 0 or 1 to indicate whether FK enforcement is off or on 2050 ** following this call. The second parameter may be a NULL pointer, in 2051 ** which case the FK enforcement setting is not reported back. </dd> 2052 ** 2053 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2054 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2055 ** There should be two additional arguments. 2056 ** The first argument is an integer which is 0 to disable triggers, 2057 ** positive to enable triggers or negative to leave the setting unchanged. 2058 ** The second parameter is a pointer to an integer into which 2059 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 2060 ** following this call. The second parameter may be a NULL pointer, in 2061 ** which case the trigger setting is not reported back. </dd> 2062 ** 2063 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2064 ** <dd> ^This option is used to enable or disable the two-argument 2065 ** version of the [fts3_tokenizer()] function which is part of the 2066 ** [FTS3] full-text search engine extension. 2067 ** There should be two additional arguments. 2068 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2069 ** positive to enable fts3_tokenizer() or negative to leave the setting 2070 ** unchanged. 2071 ** The second parameter is a pointer to an integer into which 2072 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2073 ** following this call. The second parameter may be a NULL pointer, in 2074 ** which case the new setting is not reported back. </dd> 2075 ** 2076 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2077 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2078 ** interface independently of the [load_extension()] SQL function. 2079 ** The [sqlite3_enable_load_extension()] API enables or disables both the 2080 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2081 ** There should be two additional arguments. 2082 ** When the first argument to this interface is 1, then only the C-API is 2083 ** enabled and the SQL function remains disabled. If the first argument to 2084 ** this interface is 0, then both the C-API and the SQL function are disabled. 2085 ** If the first argument is -1, then no changes are made to state of either the 2086 ** C-API or the SQL function. 2087 ** The second parameter is a pointer to an integer into which 2088 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2089 ** is disabled or enabled following this call. The second parameter may 2090 ** be a NULL pointer, in which case the new setting is not reported back. 2091 ** </dd> 2092 ** 2093 ** <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2094 ** <dd> ^This option is used to change the name of the "main" database 2095 ** schema. ^The sole argument is a pointer to a constant UTF8 string 2096 ** which will become the new schema name in place of "main". ^SQLite 2097 ** does not make a copy of the new main schema name string, so the application 2098 ** must ensure that the argument passed into this DBCONFIG option is unchanged 2099 ** until after the database connection closes. 2100 ** </dd> 2101 ** 2102 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2103 ** <dd> Usually, when a database in wal mode is closed or detached from a 2104 ** database handle, SQLite checks if this will mean that there are now no 2105 ** connections at all to the database. If so, it performs a checkpoint 2106 ** operation before closing the connection. This option may be used to 2107 ** override this behaviour. The first parameter passed to this operation 2108 ** is an integer - positive to disable checkpoints-on-close, or zero (the 2109 ** default) to enable them, and negative to leave the setting unchanged. 2110 ** The second parameter is a pointer to an integer 2111 ** into which is written 0 or 1 to indicate whether checkpoints-on-close 2112 ** have been disabled - 0 if they are not disabled, 1 if they are. 2113 ** </dd> 2114 ** 2115 ** <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2116 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2117 ** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2118 ** a single SQL query statement will always use the same algorithm regardless 2119 ** of values of [bound parameters].)^ The QPSG disables some query optimizations 2120 ** that look at the values of bound parameters, which can make some queries 2121 ** slower. But the QPSG has the advantage of more predictable behavior. With 2122 ** the QPSG active, SQLite will always use the same query plan in the field as 2123 ** was used during testing in the lab. 2124 ** The first argument to this setting is an integer which is 0 to disable 2125 ** the QPSG, positive to enable QPSG, or negative to leave the setting 2126 ** unchanged. The second parameter is a pointer to an integer into which 2127 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2128 ** following this call. 2129 ** </dd> 2130 ** 2131 ** <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2132 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2133 ** include output for any operations performed by trigger programs. This 2134 ** option is used to set or clear (the default) a flag that governs this 2135 ** behavior. The first parameter passed to this operation is an integer - 2136 ** positive to enable output for trigger programs, or zero to disable it, 2137 ** or negative to leave the setting unchanged. 2138 ** The second parameter is a pointer to an integer into which is written 2139 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2140 ** it is not disabled, 1 if it is. 2141 ** </dd> 2142 ** 2143 ** <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2144 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2145 ** [VACUUM] in order to reset a database back to an empty database 2146 ** with no schema and no content. The following process works even for 2147 ** a badly corrupted database file: 2148 ** <ol> 2149 ** <li> If the database connection is newly opened, make sure it has read the 2150 ** database schema by preparing then discarding some query against the 2151 ** database, or calling sqlite3_table_column_metadata(), ignoring any 2152 ** errors. This step is only necessary if the application desires to keep 2153 ** the database in WAL mode after the reset if it was in WAL mode before 2154 ** the reset. 2155 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2156 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2157 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2158 ** </ol> 2159 ** Because resetting a database is destructive and irreversible, the 2160 ** process requires the use of this obscure API and multiple steps to help 2161 ** ensure that it does not happen by accident. 2162 ** </dd> 2163 ** </dl> 2164 */ 2165 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2166 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2167 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2168 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2169 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2170 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2171 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2172 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2173 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2174 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2175 #define SQLITE_DBCONFIG_MAX 1009 /* Largest DBCONFIG */ 2176 2177 /* 2178 ** CAPI3REF: Enable Or Disable Extended Result Codes 2179 ** METHOD: sqlite3 2180 ** 2181 ** ^The sqlite3_extended_result_codes() routine enables or disables the 2182 ** [extended result codes] feature of SQLite. ^The extended result 2183 ** codes are disabled by default for historical compatibility. 2184 */ 2185 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2186 2187 /* 2188 ** CAPI3REF: Last Insert Rowid 2189 ** METHOD: sqlite3 2190 ** 2191 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2192 ** has a unique 64-bit signed 2193 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2194 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2195 ** names are not also used by explicitly declared columns. ^If 2196 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2197 ** is another alias for the rowid. 2198 ** 2199 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2200 ** the most recent successful [INSERT] into a rowid table or [virtual table] 2201 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2202 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2203 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2204 ** zero. 2205 ** 2206 ** As well as being set automatically as rows are inserted into database 2207 ** tables, the value returned by this function may be set explicitly by 2208 ** [sqlite3_set_last_insert_rowid()] 2209 ** 2210 ** Some virtual table implementations may INSERT rows into rowid tables as 2211 ** part of committing a transaction (e.g. to flush data accumulated in memory 2212 ** to disk). In this case subsequent calls to this function return the rowid 2213 ** associated with these internal INSERT operations, which leads to 2214 ** unintuitive results. Virtual table implementations that do write to rowid 2215 ** tables in this way can avoid this problem by restoring the original 2216 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2217 ** control to the user. 2218 ** 2219 ** ^(If an [INSERT] occurs within a trigger then this routine will 2220 ** return the [rowid] of the inserted row as long as the trigger is 2221 ** running. Once the trigger program ends, the value returned 2222 ** by this routine reverts to what it was before the trigger was fired.)^ 2223 ** 2224 ** ^An [INSERT] that fails due to a constraint violation is not a 2225 ** successful [INSERT] and does not change the value returned by this 2226 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2227 ** and INSERT OR ABORT make no changes to the return value of this 2228 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2229 ** encounters a constraint violation, it does not fail. The 2230 ** INSERT continues to completion after deleting rows that caused 2231 ** the constraint problem so INSERT OR REPLACE will always change 2232 ** the return value of this interface.)^ 2233 ** 2234 ** ^For the purposes of this routine, an [INSERT] is considered to 2235 ** be successful even if it is subsequently rolled back. 2236 ** 2237 ** This function is accessible to SQL statements via the 2238 ** [last_insert_rowid() SQL function]. 2239 ** 2240 ** If a separate thread performs a new [INSERT] on the same 2241 ** database connection while the [sqlite3_last_insert_rowid()] 2242 ** function is running and thus changes the last insert [rowid], 2243 ** then the value returned by [sqlite3_last_insert_rowid()] is 2244 ** unpredictable and might not equal either the old or the new 2245 ** last insert [rowid]. 2246 */ 2247 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2248 2249 /* 2250 ** CAPI3REF: Set the Last Insert Rowid value. 2251 ** METHOD: sqlite3 2252 ** 2253 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2254 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2255 ** without inserting a row into the database. 2256 */ 2257 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2258 2259 /* 2260 ** CAPI3REF: Count The Number Of Rows Modified 2261 ** METHOD: sqlite3 2262 ** 2263 ** ^This function returns the number of rows modified, inserted or 2264 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2265 ** statement on the database connection specified by the only parameter. 2266 ** ^Executing any other type of SQL statement does not modify the value 2267 ** returned by this function. 2268 ** 2269 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2270 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2271 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2272 ** 2273 ** Changes to a view that are intercepted by 2274 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2275 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2276 ** DELETE statement run on a view is always zero. Only changes made to real 2277 ** tables are counted. 2278 ** 2279 ** Things are more complicated if the sqlite3_changes() function is 2280 ** executed while a trigger program is running. This may happen if the 2281 ** program uses the [changes() SQL function], or if some other callback 2282 ** function invokes sqlite3_changes() directly. Essentially: 2283 ** 2284 ** <ul> 2285 ** <li> ^(Before entering a trigger program the value returned by 2286 ** sqlite3_changes() function is saved. After the trigger program 2287 ** has finished, the original value is restored.)^ 2288 ** 2289 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2290 ** statement sets the value returned by sqlite3_changes() 2291 ** upon completion as normal. Of course, this value will not include 2292 ** any changes performed by sub-triggers, as the sqlite3_changes() 2293 ** value will be saved and restored after each sub-trigger has run.)^ 2294 ** </ul> 2295 ** 2296 ** ^This means that if the changes() SQL function (or similar) is used 2297 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2298 ** returns the value as set when the calling statement began executing. 2299 ** ^If it is used by the second or subsequent such statement within a trigger 2300 ** program, the value returned reflects the number of rows modified by the 2301 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2302 ** 2303 ** If a separate thread makes changes on the same database connection 2304 ** while [sqlite3_changes()] is running then the value returned 2305 ** is unpredictable and not meaningful. 2306 ** 2307 ** See also: 2308 ** <ul> 2309 ** <li> the [sqlite3_total_changes()] interface 2310 ** <li> the [count_changes pragma] 2311 ** <li> the [changes() SQL function] 2312 ** <li> the [data_version pragma] 2313 ** </ul> 2314 */ 2315 SQLITE_API int sqlite3_changes(sqlite3*); 2316 2317 /* 2318 ** CAPI3REF: Total Number Of Rows Modified 2319 ** METHOD: sqlite3 2320 ** 2321 ** ^This function returns the total number of rows inserted, modified or 2322 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2323 ** since the database connection was opened, including those executed as 2324 ** part of trigger programs. ^Executing any other type of SQL statement 2325 ** does not affect the value returned by sqlite3_total_changes(). 2326 ** 2327 ** ^Changes made as part of [foreign key actions] are included in the 2328 ** count, but those made as part of REPLACE constraint resolution are 2329 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2330 ** are not counted. 2331 ** 2332 ** This the [sqlite3_total_changes(D)] interface only reports the number 2333 ** of rows that changed due to SQL statement run against database 2334 ** connection D. Any changes by other database connections are ignored. 2335 ** To detect changes against a database file from other database 2336 ** connections use the [PRAGMA data_version] command or the 2337 ** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2338 ** 2339 ** If a separate thread makes changes on the same database connection 2340 ** while [sqlite3_total_changes()] is running then the value 2341 ** returned is unpredictable and not meaningful. 2342 ** 2343 ** See also: 2344 ** <ul> 2345 ** <li> the [sqlite3_changes()] interface 2346 ** <li> the [count_changes pragma] 2347 ** <li> the [changes() SQL function] 2348 ** <li> the [data_version pragma] 2349 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2350 ** </ul> 2351 */ 2352 SQLITE_API int sqlite3_total_changes(sqlite3*); 2353 2354 /* 2355 ** CAPI3REF: Interrupt A Long-Running Query 2356 ** METHOD: sqlite3 2357 ** 2358 ** ^This function causes any pending database operation to abort and 2359 ** return at its earliest opportunity. This routine is typically 2360 ** called in response to a user action such as pressing "Cancel" 2361 ** or Ctrl-C where the user wants a long query operation to halt 2362 ** immediately. 2363 ** 2364 ** ^It is safe to call this routine from a thread different from the 2365 ** thread that is currently running the database operation. But it 2366 ** is not safe to call this routine with a [database connection] that 2367 ** is closed or might close before sqlite3_interrupt() returns. 2368 ** 2369 ** ^If an SQL operation is very nearly finished at the time when 2370 ** sqlite3_interrupt() is called, then it might not have an opportunity 2371 ** to be interrupted and might continue to completion. 2372 ** 2373 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2374 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2375 ** that is inside an explicit transaction, then the entire transaction 2376 ** will be rolled back automatically. 2377 ** 2378 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2379 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2380 ** that are started after the sqlite3_interrupt() call and before the 2381 ** running statements reaches zero are interrupted as if they had been 2382 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2383 ** that are started after the running statement count reaches zero are 2384 ** not effected by the sqlite3_interrupt(). 2385 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2386 ** SQL statements is a no-op and has no effect on SQL statements 2387 ** that are started after the sqlite3_interrupt() call returns. 2388 */ 2389 SQLITE_API void sqlite3_interrupt(sqlite3*); 2390 2391 /* 2392 ** CAPI3REF: Determine If An SQL Statement Is Complete 2393 ** 2394 ** These routines are useful during command-line input to determine if the 2395 ** currently entered text seems to form a complete SQL statement or 2396 ** if additional input is needed before sending the text into 2397 ** SQLite for parsing. ^These routines return 1 if the input string 2398 ** appears to be a complete SQL statement. ^A statement is judged to be 2399 ** complete if it ends with a semicolon token and is not a prefix of a 2400 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2401 ** string literals or quoted identifier names or comments are not 2402 ** independent tokens (they are part of the token in which they are 2403 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2404 ** and comments that follow the final semicolon are ignored. 2405 ** 2406 ** ^These routines return 0 if the statement is incomplete. ^If a 2407 ** memory allocation fails, then SQLITE_NOMEM is returned. 2408 ** 2409 ** ^These routines do not parse the SQL statements thus 2410 ** will not detect syntactically incorrect SQL. 2411 ** 2412 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2413 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2414 ** automatically by sqlite3_complete16(). If that initialization fails, 2415 ** then the return value from sqlite3_complete16() will be non-zero 2416 ** regardless of whether or not the input SQL is complete.)^ 2417 ** 2418 ** The input to [sqlite3_complete()] must be a zero-terminated 2419 ** UTF-8 string. 2420 ** 2421 ** The input to [sqlite3_complete16()] must be a zero-terminated 2422 ** UTF-16 string in native byte order. 2423 */ 2424 SQLITE_API int sqlite3_complete(const char *sql); 2425 SQLITE_API int sqlite3_complete16(const void *sql); 2426 2427 /* 2428 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2429 ** KEYWORDS: {busy-handler callback} {busy handler} 2430 ** METHOD: sqlite3 2431 ** 2432 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2433 ** that might be invoked with argument P whenever 2434 ** an attempt is made to access a database table associated with 2435 ** [database connection] D when another thread 2436 ** or process has the table locked. 2437 ** The sqlite3_busy_handler() interface is used to implement 2438 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2439 ** 2440 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2441 ** is returned immediately upon encountering the lock. ^If the busy callback 2442 ** is not NULL, then the callback might be invoked with two arguments. 2443 ** 2444 ** ^The first argument to the busy handler is a copy of the void* pointer which 2445 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2446 ** the busy handler callback is the number of times that the busy handler has 2447 ** been invoked previously for the same locking event. ^If the 2448 ** busy callback returns 0, then no additional attempts are made to 2449 ** access the database and [SQLITE_BUSY] is returned 2450 ** to the application. 2451 ** ^If the callback returns non-zero, then another attempt 2452 ** is made to access the database and the cycle repeats. 2453 ** 2454 ** The presence of a busy handler does not guarantee that it will be invoked 2455 ** when there is lock contention. ^If SQLite determines that invoking the busy 2456 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2457 ** to the application instead of invoking the 2458 ** busy handler. 2459 ** Consider a scenario where one process is holding a read lock that 2460 ** it is trying to promote to a reserved lock and 2461 ** a second process is holding a reserved lock that it is trying 2462 ** to promote to an exclusive lock. The first process cannot proceed 2463 ** because it is blocked by the second and the second process cannot 2464 ** proceed because it is blocked by the first. If both processes 2465 ** invoke the busy handlers, neither will make any progress. Therefore, 2466 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2467 ** will induce the first process to release its read lock and allow 2468 ** the second process to proceed. 2469 ** 2470 ** ^The default busy callback is NULL. 2471 ** 2472 ** ^(There can only be a single busy handler defined for each 2473 ** [database connection]. Setting a new busy handler clears any 2474 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2475 ** or evaluating [PRAGMA busy_timeout=N] will change the 2476 ** busy handler and thus clear any previously set busy handler. 2477 ** 2478 ** The busy callback should not take any actions which modify the 2479 ** database connection that invoked the busy handler. In other words, 2480 ** the busy handler is not reentrant. Any such actions 2481 ** result in undefined behavior. 2482 ** 2483 ** A busy handler must not close the database connection 2484 ** or [prepared statement] that invoked the busy handler. 2485 */ 2486 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2487 2488 /* 2489 ** CAPI3REF: Set A Busy Timeout 2490 ** METHOD: sqlite3 2491 ** 2492 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2493 ** for a specified amount of time when a table is locked. ^The handler 2494 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2495 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2496 ** the handler returns 0 which causes [sqlite3_step()] to return 2497 ** [SQLITE_BUSY]. 2498 ** 2499 ** ^Calling this routine with an argument less than or equal to zero 2500 ** turns off all busy handlers. 2501 ** 2502 ** ^(There can only be a single busy handler for a particular 2503 ** [database connection] at any given moment. If another busy handler 2504 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2505 ** this routine, that other busy handler is cleared.)^ 2506 ** 2507 ** See also: [PRAGMA busy_timeout] 2508 */ 2509 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2510 2511 /* 2512 ** CAPI3REF: Convenience Routines For Running Queries 2513 ** METHOD: sqlite3 2514 ** 2515 ** This is a legacy interface that is preserved for backwards compatibility. 2516 ** Use of this interface is not recommended. 2517 ** 2518 ** Definition: A <b>result table</b> is memory data structure created by the 2519 ** [sqlite3_get_table()] interface. A result table records the 2520 ** complete query results from one or more queries. 2521 ** 2522 ** The table conceptually has a number of rows and columns. But 2523 ** these numbers are not part of the result table itself. These 2524 ** numbers are obtained separately. Let N be the number of rows 2525 ** and M be the number of columns. 2526 ** 2527 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2528 ** There are (N+1)*M elements in the array. The first M pointers point 2529 ** to zero-terminated strings that contain the names of the columns. 2530 ** The remaining entries all point to query results. NULL values result 2531 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2532 ** string representation as returned by [sqlite3_column_text()]. 2533 ** 2534 ** A result table might consist of one or more memory allocations. 2535 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2536 ** A result table should be deallocated using [sqlite3_free_table()]. 2537 ** 2538 ** ^(As an example of the result table format, suppose a query result 2539 ** is as follows: 2540 ** 2541 ** <blockquote><pre> 2542 ** Name | Age 2543 ** ----------------------- 2544 ** Alice | 43 2545 ** Bob | 28 2546 ** Cindy | 21 2547 ** </pre></blockquote> 2548 ** 2549 ** There are two column (M==2) and three rows (N==3). Thus the 2550 ** result table has 8 entries. Suppose the result table is stored 2551 ** in an array names azResult. Then azResult holds this content: 2552 ** 2553 ** <blockquote><pre> 2554 ** azResult[0] = "Name"; 2555 ** azResult[1] = "Age"; 2556 ** azResult[2] = "Alice"; 2557 ** azResult[3] = "43"; 2558 ** azResult[4] = "Bob"; 2559 ** azResult[5] = "28"; 2560 ** azResult[6] = "Cindy"; 2561 ** azResult[7] = "21"; 2562 ** </pre></blockquote>)^ 2563 ** 2564 ** ^The sqlite3_get_table() function evaluates one or more 2565 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2566 ** string of its 2nd parameter and returns a result table to the 2567 ** pointer given in its 3rd parameter. 2568 ** 2569 ** After the application has finished with the result from sqlite3_get_table(), 2570 ** it must pass the result table pointer to sqlite3_free_table() in order to 2571 ** release the memory that was malloced. Because of the way the 2572 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2573 ** function must not try to call [sqlite3_free()] directly. Only 2574 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2575 ** 2576 ** The sqlite3_get_table() interface is implemented as a wrapper around 2577 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2578 ** to any internal data structures of SQLite. It uses only the public 2579 ** interface defined here. As a consequence, errors that occur in the 2580 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2581 ** reflected in subsequent calls to [sqlite3_errcode()] or 2582 ** [sqlite3_errmsg()]. 2583 */ 2584 SQLITE_API int sqlite3_get_table( 2585 sqlite3 *db, /* An open database */ 2586 const char *zSql, /* SQL to be evaluated */ 2587 char ***pazResult, /* Results of the query */ 2588 int *pnRow, /* Number of result rows written here */ 2589 int *pnColumn, /* Number of result columns written here */ 2590 char **pzErrmsg /* Error msg written here */ 2591 ); 2592 SQLITE_API void sqlite3_free_table(char **result); 2593 2594 /* 2595 ** CAPI3REF: Formatted String Printing Functions 2596 ** 2597 ** These routines are work-alikes of the "printf()" family of functions 2598 ** from the standard C library. 2599 ** These routines understand most of the common formatting options from 2600 ** the standard library printf() 2601 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2602 ** See the [built-in printf()] documentation for details. 2603 ** 2604 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2605 ** results into memory obtained from [sqlite3_malloc64()]. 2606 ** The strings returned by these two routines should be 2607 ** released by [sqlite3_free()]. ^Both routines return a 2608 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2609 ** memory to hold the resulting string. 2610 ** 2611 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2612 ** the standard C library. The result is written into the 2613 ** buffer supplied as the second parameter whose size is given by 2614 ** the first parameter. Note that the order of the 2615 ** first two parameters is reversed from snprintf().)^ This is an 2616 ** historical accident that cannot be fixed without breaking 2617 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2618 ** returns a pointer to its buffer instead of the number of 2619 ** characters actually written into the buffer.)^ We admit that 2620 ** the number of characters written would be a more useful return 2621 ** value but we cannot change the implementation of sqlite3_snprintf() 2622 ** now without breaking compatibility. 2623 ** 2624 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2625 ** guarantees that the buffer is always zero-terminated. ^The first 2626 ** parameter "n" is the total size of the buffer, including space for 2627 ** the zero terminator. So the longest string that can be completely 2628 ** written will be n-1 characters. 2629 ** 2630 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2631 ** 2632 ** See also: [built-in printf()], [printf() SQL function] 2633 */ 2634 SQLITE_API char *sqlite3_mprintf(const char*,...); 2635 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2636 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2637 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2638 2639 /* 2640 ** CAPI3REF: Memory Allocation Subsystem 2641 ** 2642 ** The SQLite core uses these three routines for all of its own 2643 ** internal memory allocation needs. "Core" in the previous sentence 2644 ** does not include operating-system specific VFS implementation. The 2645 ** Windows VFS uses native malloc() and free() for some operations. 2646 ** 2647 ** ^The sqlite3_malloc() routine returns a pointer to a block 2648 ** of memory at least N bytes in length, where N is the parameter. 2649 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2650 ** memory, it returns a NULL pointer. ^If the parameter N to 2651 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2652 ** a NULL pointer. 2653 ** 2654 ** ^The sqlite3_malloc64(N) routine works just like 2655 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2656 ** of a signed 32-bit integer. 2657 ** 2658 ** ^Calling sqlite3_free() with a pointer previously returned 2659 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2660 ** that it might be reused. ^The sqlite3_free() routine is 2661 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2662 ** to sqlite3_free() is harmless. After being freed, memory 2663 ** should neither be read nor written. Even reading previously freed 2664 ** memory might result in a segmentation fault or other severe error. 2665 ** Memory corruption, a segmentation fault, or other severe error 2666 ** might result if sqlite3_free() is called with a non-NULL pointer that 2667 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2668 ** 2669 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 2670 ** prior memory allocation X to be at least N bytes. 2671 ** ^If the X parameter to sqlite3_realloc(X,N) 2672 ** is a NULL pointer then its behavior is identical to calling 2673 ** sqlite3_malloc(N). 2674 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2675 ** negative then the behavior is exactly the same as calling 2676 ** sqlite3_free(X). 2677 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2678 ** of at least N bytes in size or NULL if insufficient memory is available. 2679 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2680 ** of the prior allocation are copied into the beginning of buffer returned 2681 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 2682 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2683 ** prior allocation is not freed. 2684 ** 2685 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 2686 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2687 ** of a 32-bit signed integer. 2688 ** 2689 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2690 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2691 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2692 ** ^The value returned by sqlite3_msize(X) might be larger than the number 2693 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 2694 ** sqlite3_msize(X) returns zero. If X points to something that is not 2695 ** the beginning of memory allocation, or if it points to a formerly 2696 ** valid memory allocation that has now been freed, then the behavior 2697 ** of sqlite3_msize(X) is undefined and possibly harmful. 2698 ** 2699 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2700 ** sqlite3_malloc64(), and sqlite3_realloc64() 2701 ** is always aligned to at least an 8 byte boundary, or to a 2702 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2703 ** option is used. 2704 ** 2705 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2706 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2707 ** implementation of these routines to be omitted. That capability 2708 ** is no longer provided. Only built-in memory allocators can be used. 2709 ** 2710 ** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2711 ** the system malloc() and free() directly when converting 2712 ** filenames between the UTF-8 encoding used by SQLite 2713 ** and whatever filename encoding is used by the particular Windows 2714 ** installation. Memory allocation errors were detected, but 2715 ** they were reported back as [SQLITE_CANTOPEN] or 2716 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2717 ** 2718 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2719 ** must be either NULL or else pointers obtained from a prior 2720 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2721 ** not yet been released. 2722 ** 2723 ** The application must not read or write any part of 2724 ** a block of memory after it has been released using 2725 ** [sqlite3_free()] or [sqlite3_realloc()]. 2726 */ 2727 SQLITE_API void *sqlite3_malloc(int); 2728 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 2729 SQLITE_API void *sqlite3_realloc(void*, int); 2730 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 2731 SQLITE_API void sqlite3_free(void*); 2732 SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 2733 2734 /* 2735 ** CAPI3REF: Memory Allocator Statistics 2736 ** 2737 ** SQLite provides these two interfaces for reporting on the status 2738 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2739 ** routines, which form the built-in memory allocation subsystem. 2740 ** 2741 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2742 ** of memory currently outstanding (malloced but not freed). 2743 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2744 ** value of [sqlite3_memory_used()] since the high-water mark 2745 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2746 ** [sqlite3_memory_highwater()] include any overhead 2747 ** added by SQLite in its implementation of [sqlite3_malloc()], 2748 ** but not overhead added by the any underlying system library 2749 ** routines that [sqlite3_malloc()] may call. 2750 ** 2751 ** ^The memory high-water mark is reset to the current value of 2752 ** [sqlite3_memory_used()] if and only if the parameter to 2753 ** [sqlite3_memory_highwater()] is true. ^The value returned 2754 ** by [sqlite3_memory_highwater(1)] is the high-water mark 2755 ** prior to the reset. 2756 */ 2757 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2758 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2759 2760 /* 2761 ** CAPI3REF: Pseudo-Random Number Generator 2762 ** 2763 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2764 ** select random [ROWID | ROWIDs] when inserting new records into a table that 2765 ** already uses the largest possible [ROWID]. The PRNG is also used for 2766 ** the build-in random() and randomblob() SQL functions. This interface allows 2767 ** applications to access the same PRNG for other purposes. 2768 ** 2769 ** ^A call to this routine stores N bytes of randomness into buffer P. 2770 ** ^The P parameter can be a NULL pointer. 2771 ** 2772 ** ^If this routine has not been previously called or if the previous 2773 ** call had N less than one or a NULL pointer for P, then the PRNG is 2774 ** seeded using randomness obtained from the xRandomness method of 2775 ** the default [sqlite3_vfs] object. 2776 ** ^If the previous call to this routine had an N of 1 or more and a 2777 ** non-NULL P then the pseudo-randomness is generated 2778 ** internally and without recourse to the [sqlite3_vfs] xRandomness 2779 ** method. 2780 */ 2781 SQLITE_API void sqlite3_randomness(int N, void *P); 2782 2783 /* 2784 ** CAPI3REF: Compile-Time Authorization Callbacks 2785 ** METHOD: sqlite3 2786 ** KEYWORDS: {authorizer callback} 2787 ** 2788 ** ^This routine registers an authorizer callback with a particular 2789 ** [database connection], supplied in the first argument. 2790 ** ^The authorizer callback is invoked as SQL statements are being compiled 2791 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2792 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2793 ** and [sqlite3_prepare16_v3()]. ^At various 2794 ** points during the compilation process, as logic is being created 2795 ** to perform various actions, the authorizer callback is invoked to 2796 ** see if those actions are allowed. ^The authorizer callback should 2797 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2798 ** specific action but allow the SQL statement to continue to be 2799 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2800 ** rejected with an error. ^If the authorizer callback returns 2801 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2802 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2803 ** the authorizer will fail with an error message. 2804 ** 2805 ** When the callback returns [SQLITE_OK], that means the operation 2806 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 2807 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 2808 ** authorizer will fail with an error message explaining that 2809 ** access is denied. 2810 ** 2811 ** ^The first parameter to the authorizer callback is a copy of the third 2812 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2813 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 2814 ** the particular action to be authorized. ^The third through sixth parameters 2815 ** to the callback are either NULL pointers or zero-terminated strings 2816 ** that contain additional details about the action to be authorized. 2817 ** Applications must always be prepared to encounter a NULL pointer in any 2818 ** of the third through the sixth parameters of the authorization callback. 2819 ** 2820 ** ^If the action code is [SQLITE_READ] 2821 ** and the callback returns [SQLITE_IGNORE] then the 2822 ** [prepared statement] statement is constructed to substitute 2823 ** a NULL value in place of the table column that would have 2824 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2825 ** return can be used to deny an untrusted user access to individual 2826 ** columns of a table. 2827 ** ^When a table is referenced by a [SELECT] but no column values are 2828 ** extracted from that table (for example in a query like 2829 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 2830 ** is invoked once for that table with a column name that is an empty string. 2831 ** ^If the action code is [SQLITE_DELETE] and the callback returns 2832 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2833 ** [truncate optimization] is disabled and all rows are deleted individually. 2834 ** 2835 ** An authorizer is used when [sqlite3_prepare | preparing] 2836 ** SQL statements from an untrusted source, to ensure that the SQL statements 2837 ** do not try to access data they are not allowed to see, or that they do not 2838 ** try to execute malicious statements that damage the database. For 2839 ** example, an application may allow a user to enter arbitrary 2840 ** SQL queries for evaluation by a database. But the application does 2841 ** not want the user to be able to make arbitrary changes to the 2842 ** database. An authorizer could then be put in place while the 2843 ** user-entered SQL is being [sqlite3_prepare | prepared] that 2844 ** disallows everything except [SELECT] statements. 2845 ** 2846 ** Applications that need to process SQL from untrusted sources 2847 ** might also consider lowering resource limits using [sqlite3_limit()] 2848 ** and limiting database size using the [max_page_count] [PRAGMA] 2849 ** in addition to using an authorizer. 2850 ** 2851 ** ^(Only a single authorizer can be in place on a database connection 2852 ** at a time. Each call to sqlite3_set_authorizer overrides the 2853 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2854 ** The authorizer is disabled by default. 2855 ** 2856 ** The authorizer callback must not do anything that will modify 2857 ** the database connection that invoked the authorizer callback. 2858 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2859 ** database connections for the meaning of "modify" in this paragraph. 2860 ** 2861 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2862 ** statement might be re-prepared during [sqlite3_step()] due to a 2863 ** schema change. Hence, the application should ensure that the 2864 ** correct authorizer callback remains in place during the [sqlite3_step()]. 2865 ** 2866 ** ^Note that the authorizer callback is invoked only during 2867 ** [sqlite3_prepare()] or its variants. Authorization is not 2868 ** performed during statement evaluation in [sqlite3_step()], unless 2869 ** as stated in the previous paragraph, sqlite3_step() invokes 2870 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2871 */ 2872 SQLITE_API int sqlite3_set_authorizer( 2873 sqlite3*, 2874 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2875 void *pUserData 2876 ); 2877 2878 /* 2879 ** CAPI3REF: Authorizer Return Codes 2880 ** 2881 ** The [sqlite3_set_authorizer | authorizer callback function] must 2882 ** return either [SQLITE_OK] or one of these two constants in order 2883 ** to signal SQLite whether or not the action is permitted. See the 2884 ** [sqlite3_set_authorizer | authorizer documentation] for additional 2885 ** information. 2886 ** 2887 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2888 ** returned from the [sqlite3_vtab_on_conflict()] interface. 2889 */ 2890 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2891 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2892 2893 /* 2894 ** CAPI3REF: Authorizer Action Codes 2895 ** 2896 ** The [sqlite3_set_authorizer()] interface registers a callback function 2897 ** that is invoked to authorize certain SQL statement actions. The 2898 ** second parameter to the callback is an integer code that specifies 2899 ** what action is being authorized. These are the integer action codes that 2900 ** the authorizer callback may be passed. 2901 ** 2902 ** These action code values signify what kind of operation is to be 2903 ** authorized. The 3rd and 4th parameters to the authorization 2904 ** callback function will be parameters or NULL depending on which of these 2905 ** codes is used as the second parameter. ^(The 5th parameter to the 2906 ** authorizer callback is the name of the database ("main", "temp", 2907 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2908 ** is the name of the inner-most trigger or view that is responsible for 2909 ** the access attempt or NULL if this access attempt is directly from 2910 ** top-level SQL code. 2911 */ 2912 /******************************************* 3rd ************ 4th ***********/ 2913 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2914 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2915 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2916 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2917 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2918 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2919 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2920 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2921 #define SQLITE_DELETE 9 /* Table Name NULL */ 2922 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2923 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2924 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2925 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2926 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2927 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2928 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2929 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2930 #define SQLITE_INSERT 18 /* Table Name NULL */ 2931 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2932 #define SQLITE_READ 20 /* Table Name Column Name */ 2933 #define SQLITE_SELECT 21 /* NULL NULL */ 2934 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 2935 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 2936 #define SQLITE_ATTACH 24 /* Filename NULL */ 2937 #define SQLITE_DETACH 25 /* Database Name NULL */ 2938 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2939 #define SQLITE_REINDEX 27 /* Index Name NULL */ 2940 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 2941 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2942 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2943 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 2944 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2945 #define SQLITE_COPY 0 /* No longer used */ 2946 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 2947 2948 /* 2949 ** CAPI3REF: Tracing And Profiling Functions 2950 ** METHOD: sqlite3 2951 ** 2952 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 2953 ** instead of the routines described here. 2954 ** 2955 ** These routines register callback functions that can be used for 2956 ** tracing and profiling the execution of SQL statements. 2957 ** 2958 ** ^The callback function registered by sqlite3_trace() is invoked at 2959 ** various times when an SQL statement is being run by [sqlite3_step()]. 2960 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2961 ** SQL statement text as the statement first begins executing. 2962 ** ^(Additional sqlite3_trace() callbacks might occur 2963 ** as each triggered subprogram is entered. The callbacks for triggers 2964 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 2965 ** 2966 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2967 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2968 ** 2969 ** ^The callback function registered by sqlite3_profile() is invoked 2970 ** as each SQL statement finishes. ^The profile callback contains 2971 ** the original statement text and an estimate of wall-clock time 2972 ** of how long that statement took to run. ^The profile callback 2973 ** time is in units of nanoseconds, however the current implementation 2974 ** is only capable of millisecond resolution so the six least significant 2975 ** digits in the time are meaningless. Future versions of SQLite 2976 ** might provide greater resolution on the profiler callback. The 2977 ** sqlite3_profile() function is considered experimental and is 2978 ** subject to change in future versions of SQLite. 2979 */ 2980 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 2981 void(*xTrace)(void*,const char*), void*); 2982 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 2983 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2984 2985 /* 2986 ** CAPI3REF: SQL Trace Event Codes 2987 ** KEYWORDS: SQLITE_TRACE 2988 ** 2989 ** These constants identify classes of events that can be monitored 2990 ** using the [sqlite3_trace_v2()] tracing logic. The M argument 2991 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 2992 ** the following constants. ^The first argument to the trace callback 2993 ** is one of the following constants. 2994 ** 2995 ** New tracing constants may be added in future releases. 2996 ** 2997 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 2998 ** ^The T argument is one of the integer type codes above. 2999 ** ^The C argument is a copy of the context pointer passed in as the 3000 ** fourth argument to [sqlite3_trace_v2()]. 3001 ** The P and X arguments are pointers whose meanings depend on T. 3002 ** 3003 ** <dl> 3004 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3005 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3006 ** first begins running and possibly at other times during the 3007 ** execution of the prepared statement, such as at the start of each 3008 ** trigger subprogram. ^The P argument is a pointer to the 3009 ** [prepared statement]. ^The X argument is a pointer to a string which 3010 ** is the unexpanded SQL text of the prepared statement or an SQL comment 3011 ** that indicates the invocation of a trigger. ^The callback can compute 3012 ** the same text that would have been returned by the legacy [sqlite3_trace()] 3013 ** interface by using the X argument when X begins with "--" and invoking 3014 ** [sqlite3_expanded_sql(P)] otherwise. 3015 ** 3016 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3017 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3018 ** information as is provided by the [sqlite3_profile()] callback. 3019 ** ^The P argument is a pointer to the [prepared statement] and the 3020 ** X argument points to a 64-bit integer which is the estimated of 3021 ** the number of nanosecond that the prepared statement took to run. 3022 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3023 ** 3024 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3025 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3026 ** statement generates a single row of result. 3027 ** ^The P argument is a pointer to the [prepared statement] and the 3028 ** X argument is unused. 3029 ** 3030 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3031 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3032 ** connection closes. 3033 ** ^The P argument is a pointer to the [database connection] object 3034 ** and the X argument is unused. 3035 ** </dl> 3036 */ 3037 #define SQLITE_TRACE_STMT 0x01 3038 #define SQLITE_TRACE_PROFILE 0x02 3039 #define SQLITE_TRACE_ROW 0x04 3040 #define SQLITE_TRACE_CLOSE 0x08 3041 3042 /* 3043 ** CAPI3REF: SQL Trace Hook 3044 ** METHOD: sqlite3 3045 ** 3046 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3047 ** function X against [database connection] D, using property mask M 3048 ** and context pointer P. ^If the X callback is 3049 ** NULL or if the M mask is zero, then tracing is disabled. The 3050 ** M argument should be the bitwise OR-ed combination of 3051 ** zero or more [SQLITE_TRACE] constants. 3052 ** 3053 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3054 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3055 ** 3056 ** ^The X callback is invoked whenever any of the events identified by 3057 ** mask M occur. ^The integer return value from the callback is currently 3058 ** ignored, though this may change in future releases. Callback 3059 ** implementations should return zero to ensure future compatibility. 3060 ** 3061 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3062 ** ^The T argument is one of the [SQLITE_TRACE] 3063 ** constants to indicate why the callback was invoked. 3064 ** ^The C argument is a copy of the context pointer. 3065 ** The P and X arguments are pointers whose meanings depend on T. 3066 ** 3067 ** The sqlite3_trace_v2() interface is intended to replace the legacy 3068 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3069 ** are deprecated. 3070 */ 3071 SQLITE_API int sqlite3_trace_v2( 3072 sqlite3*, 3073 unsigned uMask, 3074 int(*xCallback)(unsigned,void*,void*,void*), 3075 void *pCtx 3076 ); 3077 3078 /* 3079 ** CAPI3REF: Query Progress Callbacks 3080 ** METHOD: sqlite3 3081 ** 3082 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3083 ** function X to be invoked periodically during long running calls to 3084 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3085 ** database connection D. An example use for this 3086 ** interface is to keep a GUI updated during a large query. 3087 ** 3088 ** ^The parameter P is passed through as the only parameter to the 3089 ** callback function X. ^The parameter N is the approximate number of 3090 ** [virtual machine instructions] that are evaluated between successive 3091 ** invocations of the callback X. ^If N is less than one then the progress 3092 ** handler is disabled. 3093 ** 3094 ** ^Only a single progress handler may be defined at one time per 3095 ** [database connection]; setting a new progress handler cancels the 3096 ** old one. ^Setting parameter X to NULL disables the progress handler. 3097 ** ^The progress handler is also disabled by setting N to a value less 3098 ** than 1. 3099 ** 3100 ** ^If the progress callback returns non-zero, the operation is 3101 ** interrupted. This feature can be used to implement a 3102 ** "Cancel" button on a GUI progress dialog box. 3103 ** 3104 ** The progress handler callback must not do anything that will modify 3105 ** the database connection that invoked the progress handler. 3106 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3107 ** database connections for the meaning of "modify" in this paragraph. 3108 ** 3109 */ 3110 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3111 3112 /* 3113 ** CAPI3REF: Opening A New Database Connection 3114 ** CONSTRUCTOR: sqlite3 3115 ** 3116 ** ^These routines open an SQLite database file as specified by the 3117 ** filename argument. ^The filename argument is interpreted as UTF-8 for 3118 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3119 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 3120 ** returned in *ppDb, even if an error occurs. The only exception is that 3121 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3122 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3123 ** object.)^ ^(If the database is opened (and/or created) successfully, then 3124 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3125 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3126 ** an English language description of the error following a failure of any 3127 ** of the sqlite3_open() routines. 3128 ** 3129 ** ^The default encoding will be UTF-8 for databases created using 3130 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3131 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 3132 ** 3133 ** Whether or not an error occurs when it is opened, resources 3134 ** associated with the [database connection] handle should be released by 3135 ** passing it to [sqlite3_close()] when it is no longer required. 3136 ** 3137 ** The sqlite3_open_v2() interface works like sqlite3_open() 3138 ** except that it accepts two additional parameters for additional control 3139 ** over the new database connection. ^(The flags parameter to 3140 ** sqlite3_open_v2() can take one of 3141 ** the following three values, optionally combined with the 3142 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 3143 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 3144 ** 3145 ** <dl> 3146 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3147 ** <dd>The database is opened in read-only mode. If the database does not 3148 ** already exist, an error is returned.</dd>)^ 3149 ** 3150 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3151 ** <dd>The database is opened for reading and writing if possible, or reading 3152 ** only if the file is write protected by the operating system. In either 3153 ** case the database must already exist, otherwise an error is returned.</dd>)^ 3154 ** 3155 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3156 ** <dd>The database is opened for reading and writing, and is created if 3157 ** it does not already exist. This is the behavior that is always used for 3158 ** sqlite3_open() and sqlite3_open16().</dd>)^ 3159 ** </dl> 3160 ** 3161 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3162 ** combinations shown above optionally combined with other 3163 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3164 ** then the behavior is undefined. 3165 ** 3166 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 3167 ** opens in the multi-thread [threading mode] as long as the single-thread 3168 ** mode has not been set at compile-time or start-time. ^If the 3169 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 3170 ** in the serialized [threading mode] unless single-thread was 3171 ** previously selected at compile-time or start-time. 3172 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 3173 ** eligible to use [shared cache mode], regardless of whether or not shared 3174 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3175 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3176 ** participate in [shared cache mode] even if it is enabled. 3177 ** 3178 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3179 ** [sqlite3_vfs] object that defines the operating system interface that 3180 ** the new database connection should use. ^If the fourth parameter is 3181 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3182 ** 3183 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3184 ** is created for the connection. ^This in-memory database will vanish when 3185 ** the database connection is closed. Future versions of SQLite might 3186 ** make use of additional special filenames that begin with the ":" character. 3187 ** It is recommended that when a database filename actually does begin with 3188 ** a ":" character you should prefix the filename with a pathname such as 3189 ** "./" to avoid ambiguity. 3190 ** 3191 ** ^If the filename is an empty string, then a private, temporary 3192 ** on-disk database will be created. ^This private database will be 3193 ** automatically deleted as soon as the database connection is closed. 3194 ** 3195 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3196 ** 3197 ** ^If [URI filename] interpretation is enabled, and the filename argument 3198 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3199 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3200 ** set in the third argument to sqlite3_open_v2(), or if it has 3201 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3202 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3203 ** URI filename interpretation is turned off 3204 ** by default, but future releases of SQLite might enable URI filename 3205 ** interpretation by default. See "[URI filenames]" for additional 3206 ** information. 3207 ** 3208 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3209 ** authority, then it must be either an empty string or the string 3210 ** "localhost". ^If the authority is not an empty string or "localhost", an 3211 ** error is returned to the caller. ^The fragment component of a URI, if 3212 ** present, is ignored. 3213 ** 3214 ** ^SQLite uses the path component of the URI as the name of the disk file 3215 ** which contains the database. ^If the path begins with a '/' character, 3216 ** then it is interpreted as an absolute path. ^If the path does not begin 3217 ** with a '/' (meaning that the authority section is omitted from the URI) 3218 ** then the path is interpreted as a relative path. 3219 ** ^(On windows, the first component of an absolute path 3220 ** is a drive specification (e.g. "C:").)^ 3221 ** 3222 ** [[core URI query parameters]] 3223 ** The query component of a URI may contain parameters that are interpreted 3224 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3225 ** SQLite and its built-in [VFSes] interpret the 3226 ** following query parameters: 3227 ** 3228 ** <ul> 3229 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3230 ** a VFS object that provides the operating system interface that should 3231 ** be used to access the database file on disk. ^If this option is set to 3232 ** an empty string the default VFS object is used. ^Specifying an unknown 3233 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3234 ** present, then the VFS specified by the option takes precedence over 3235 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3236 ** 3237 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3238 ** "rwc", or "memory". Attempting to set it to any other value is 3239 ** an error)^. 3240 ** ^If "ro" is specified, then the database is opened for read-only 3241 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3242 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3243 ** "rw", then the database is opened for read-write (but not create) 3244 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3245 ** been set. ^Value "rwc" is equivalent to setting both 3246 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3247 ** set to "memory" then a pure [in-memory database] that never reads 3248 ** or writes from disk is used. ^It is an error to specify a value for 3249 ** the mode parameter that is less restrictive than that specified by 3250 ** the flags passed in the third parameter to sqlite3_open_v2(). 3251 ** 3252 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3253 ** "private". ^Setting it to "shared" is equivalent to setting the 3254 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3255 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3256 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3257 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3258 ** a URI filename, its value overrides any behavior requested by setting 3259 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3260 ** 3261 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3262 ** [powersafe overwrite] property does or does not apply to the 3263 ** storage media on which the database file resides. 3264 ** 3265 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3266 ** which if set disables file locking in rollback journal modes. This 3267 ** is useful for accessing a database on a filesystem that does not 3268 ** support locking. Caution: Database corruption might result if two 3269 ** or more processes write to the same database and any one of those 3270 ** processes uses nolock=1. 3271 ** 3272 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3273 ** parameter that indicates that the database file is stored on 3274 ** read-only media. ^When immutable is set, SQLite assumes that the 3275 ** database file cannot be changed, even by a process with higher 3276 ** privilege, and so the database is opened read-only and all locking 3277 ** and change detection is disabled. Caution: Setting the immutable 3278 ** property on a database file that does in fact change can result 3279 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3280 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3281 ** 3282 ** </ul> 3283 ** 3284 ** ^Specifying an unknown parameter in the query component of a URI is not an 3285 ** error. Future versions of SQLite might understand additional query 3286 ** parameters. See "[query parameters with special meaning to SQLite]" for 3287 ** additional information. 3288 ** 3289 ** [[URI filename examples]] <h3>URI filename examples</h3> 3290 ** 3291 ** <table border="1" align=center cellpadding=5> 3292 ** <tr><th> URI filenames <th> Results 3293 ** <tr><td> file:data.db <td> 3294 ** Open the file "data.db" in the current directory. 3295 ** <tr><td> file:/home/fred/data.db<br> 3296 ** file:///home/fred/data.db <br> 3297 ** file://localhost/home/fred/data.db <br> <td> 3298 ** Open the database file "/home/fred/data.db". 3299 ** <tr><td> file://darkstar/home/fred/data.db <td> 3300 ** An error. "darkstar" is not a recognized authority. 3301 ** <tr><td style="white-space:nowrap"> 3302 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3303 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3304 ** C:. Note that the %20 escaping in this example is not strictly 3305 ** necessary - space characters can be used literally 3306 ** in URI filenames. 3307 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3308 ** Open file "data.db" in the current directory for read-only access. 3309 ** Regardless of whether or not shared-cache mode is enabled by 3310 ** default, use a private cache. 3311 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3312 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3313 ** that uses dot-files in place of posix advisory locking. 3314 ** <tr><td> file:data.db?mode=readonly <td> 3315 ** An error. "readonly" is not a valid option for the "mode" parameter. 3316 ** </table> 3317 ** 3318 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3319 ** query components of a URI. A hexadecimal escape sequence consists of a 3320 ** percent sign - "%" - followed by exactly two hexadecimal digits 3321 ** specifying an octet value. ^Before the path or query components of a 3322 ** URI filename are interpreted, they are encoded using UTF-8 and all 3323 ** hexadecimal escape sequences replaced by a single byte containing the 3324 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3325 ** the results are undefined. 3326 ** 3327 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3328 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3329 ** codepage is currently defined. Filenames containing international 3330 ** characters must be converted to UTF-8 prior to passing them into 3331 ** sqlite3_open() or sqlite3_open_v2(). 3332 ** 3333 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3334 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3335 ** features that require the use of temporary files may fail. 3336 ** 3337 ** See also: [sqlite3_temp_directory] 3338 */ 3339 SQLITE_API int sqlite3_open( 3340 const char *filename, /* Database filename (UTF-8) */ 3341 sqlite3 **ppDb /* OUT: SQLite db handle */ 3342 ); 3343 SQLITE_API int sqlite3_open16( 3344 const void *filename, /* Database filename (UTF-16) */ 3345 sqlite3 **ppDb /* OUT: SQLite db handle */ 3346 ); 3347 SQLITE_API int sqlite3_open_v2( 3348 const char *filename, /* Database filename (UTF-8) */ 3349 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3350 int flags, /* Flags */ 3351 const char *zVfs /* Name of VFS module to use */ 3352 ); 3353 3354 /* 3355 ** CAPI3REF: Obtain Values For URI Parameters 3356 ** 3357 ** These are utility routines, useful to VFS implementations, that check 3358 ** to see if a database file was a URI that contained a specific query 3359 ** parameter, and if so obtains the value of that query parameter. 3360 ** 3361 ** If F is the database filename pointer passed into the xOpen() method of 3362 ** a VFS implementation when the flags parameter to xOpen() has one or 3363 ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3364 ** P is the name of the query parameter, then 3365 ** sqlite3_uri_parameter(F,P) returns the value of the P 3366 ** parameter if it exists or a NULL pointer if P does not appear as a 3367 ** query parameter on F. If P is a query parameter of F 3368 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3369 ** a pointer to an empty string. 3370 ** 3371 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3372 ** parameter and returns true (1) or false (0) according to the value 3373 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3374 ** value of query parameter P is one of "yes", "true", or "on" in any 3375 ** case or if the value begins with a non-zero number. The 3376 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3377 ** query parameter P is one of "no", "false", or "off" in any case or 3378 ** if the value begins with a numeric zero. If P is not a query 3379 ** parameter on F or if the value of P is does not match any of the 3380 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3381 ** 3382 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3383 ** 64-bit signed integer and returns that integer, or D if P does not 3384 ** exist. If the value of P is something other than an integer, then 3385 ** zero is returned. 3386 ** 3387 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3388 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3389 ** is not a database file pathname pointer that SQLite passed into the xOpen 3390 ** VFS method, then the behavior of this routine is undefined and probably 3391 ** undesirable. 3392 */ 3393 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3394 SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3395 SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3396 3397 3398 /* 3399 ** CAPI3REF: Error Codes And Messages 3400 ** METHOD: sqlite3 3401 ** 3402 ** ^If the most recent sqlite3_* API call associated with 3403 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3404 ** returns the numeric [result code] or [extended result code] for that 3405 ** API call. 3406 ** ^The sqlite3_extended_errcode() 3407 ** interface is the same except that it always returns the 3408 ** [extended result code] even when extended result codes are 3409 ** disabled. 3410 ** 3411 ** The values returned by sqlite3_errcode() and/or 3412 ** sqlite3_extended_errcode() might change with each API call. 3413 ** Except, there are some interfaces that are guaranteed to never 3414 ** change the value of the error code. The error-code preserving 3415 ** interfaces are: 3416 ** 3417 ** <ul> 3418 ** <li> sqlite3_errcode() 3419 ** <li> sqlite3_extended_errcode() 3420 ** <li> sqlite3_errmsg() 3421 ** <li> sqlite3_errmsg16() 3422 ** </ul> 3423 ** 3424 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3425 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3426 ** ^(Memory to hold the error message string is managed internally. 3427 ** The application does not need to worry about freeing the result. 3428 ** However, the error string might be overwritten or deallocated by 3429 ** subsequent calls to other SQLite interface functions.)^ 3430 ** 3431 ** ^The sqlite3_errstr() interface returns the English-language text 3432 ** that describes the [result code], as UTF-8. 3433 ** ^(Memory to hold the error message string is managed internally 3434 ** and must not be freed by the application)^. 3435 ** 3436 ** When the serialized [threading mode] is in use, it might be the 3437 ** case that a second error occurs on a separate thread in between 3438 ** the time of the first error and the call to these interfaces. 3439 ** When that happens, the second error will be reported since these 3440 ** interfaces always report the most recent result. To avoid 3441 ** this, each thread can obtain exclusive use of the [database connection] D 3442 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3443 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3444 ** all calls to the interfaces listed here are completed. 3445 ** 3446 ** If an interface fails with SQLITE_MISUSE, that means the interface 3447 ** was invoked incorrectly by the application. In that case, the 3448 ** error code and message may or may not be set. 3449 */ 3450 SQLITE_API int sqlite3_errcode(sqlite3 *db); 3451 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3452 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3453 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3454 SQLITE_API const char *sqlite3_errstr(int); 3455 3456 /* 3457 ** CAPI3REF: Prepared Statement Object 3458 ** KEYWORDS: {prepared statement} {prepared statements} 3459 ** 3460 ** An instance of this object represents a single SQL statement that 3461 ** has been compiled into binary form and is ready to be evaluated. 3462 ** 3463 ** Think of each SQL statement as a separate computer program. The 3464 ** original SQL text is source code. A prepared statement object 3465 ** is the compiled object code. All SQL must be converted into a 3466 ** prepared statement before it can be run. 3467 ** 3468 ** The life-cycle of a prepared statement object usually goes like this: 3469 ** 3470 ** <ol> 3471 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3472 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 3473 ** interfaces. 3474 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3475 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3476 ** to step 2. Do this zero or more times. 3477 ** <li> Destroy the object using [sqlite3_finalize()]. 3478 ** </ol> 3479 */ 3480 typedef struct sqlite3_stmt sqlite3_stmt; 3481 3482 /* 3483 ** CAPI3REF: Run-time Limits 3484 ** METHOD: sqlite3 3485 ** 3486 ** ^(This interface allows the size of various constructs to be limited 3487 ** on a connection by connection basis. The first parameter is the 3488 ** [database connection] whose limit is to be set or queried. The 3489 ** second parameter is one of the [limit categories] that define a 3490 ** class of constructs to be size limited. The third parameter is the 3491 ** new limit for that construct.)^ 3492 ** 3493 ** ^If the new limit is a negative number, the limit is unchanged. 3494 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3495 ** [limits | hard upper bound] 3496 ** set at compile-time by a C preprocessor macro called 3497 ** [limits | SQLITE_MAX_<i>NAME</i>]. 3498 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3499 ** ^Attempts to increase a limit above its hard upper bound are 3500 ** silently truncated to the hard upper bound. 3501 ** 3502 ** ^Regardless of whether or not the limit was changed, the 3503 ** [sqlite3_limit()] interface returns the prior value of the limit. 3504 ** ^Hence, to find the current value of a limit without changing it, 3505 ** simply invoke this interface with the third parameter set to -1. 3506 ** 3507 ** Run-time limits are intended for use in applications that manage 3508 ** both their own internal database and also databases that are controlled 3509 ** by untrusted external sources. An example application might be a 3510 ** web browser that has its own databases for storing history and 3511 ** separate databases controlled by JavaScript applications downloaded 3512 ** off the Internet. The internal databases can be given the 3513 ** large, default limits. Databases managed by external sources can 3514 ** be given much smaller limits designed to prevent a denial of service 3515 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3516 ** interface to further control untrusted SQL. The size of the database 3517 ** created by an untrusted script can be contained using the 3518 ** [max_page_count] [PRAGMA]. 3519 ** 3520 ** New run-time limit categories may be added in future releases. 3521 */ 3522 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3523 3524 /* 3525 ** CAPI3REF: Run-Time Limit Categories 3526 ** KEYWORDS: {limit category} {*limit categories} 3527 ** 3528 ** These constants define various performance limits 3529 ** that can be lowered at run-time using [sqlite3_limit()]. 3530 ** The synopsis of the meanings of the various limits is shown below. 3531 ** Additional information is available at [limits | Limits in SQLite]. 3532 ** 3533 ** <dl> 3534 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3535 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3536 ** 3537 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3538 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3539 ** 3540 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3541 ** <dd>The maximum number of columns in a table definition or in the 3542 ** result set of a [SELECT] or the maximum number of columns in an index 3543 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 3544 ** 3545 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3546 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3547 ** 3548 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3549 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3550 ** 3551 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3552 ** <dd>The maximum number of instructions in a virtual machine program 3553 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3554 ** the equivalent tries to allocate space for more than this many opcodes 3555 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3556 ** 3557 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3558 ** <dd>The maximum number of arguments on a function.</dd>)^ 3559 ** 3560 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3561 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3562 ** 3563 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3564 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3565 ** <dd>The maximum length of the pattern argument to the [LIKE] or 3566 ** [GLOB] operators.</dd>)^ 3567 ** 3568 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3569 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3570 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3571 ** 3572 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3573 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 3574 ** 3575 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3576 ** <dd>The maximum number of auxiliary worker threads that a single 3577 ** [prepared statement] may start.</dd>)^ 3578 ** </dl> 3579 */ 3580 #define SQLITE_LIMIT_LENGTH 0 3581 #define SQLITE_LIMIT_SQL_LENGTH 1 3582 #define SQLITE_LIMIT_COLUMN 2 3583 #define SQLITE_LIMIT_EXPR_DEPTH 3 3584 #define SQLITE_LIMIT_COMPOUND_SELECT 4 3585 #define SQLITE_LIMIT_VDBE_OP 5 3586 #define SQLITE_LIMIT_FUNCTION_ARG 6 3587 #define SQLITE_LIMIT_ATTACHED 7 3588 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3589 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 3590 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 3591 #define SQLITE_LIMIT_WORKER_THREADS 11 3592 3593 /* 3594 ** CAPI3REF: Prepare Flags 3595 ** 3596 ** These constants define various flags that can be passed into 3597 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3598 ** [sqlite3_prepare16_v3()] interfaces. 3599 ** 3600 ** New flags may be added in future releases of SQLite. 3601 ** 3602 ** <dl> 3603 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3604 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3605 ** that the prepared statement will be retained for a long time and 3606 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3607 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3608 ** be used just once or at most a few times and then destroyed using 3609 ** [sqlite3_finalize()] relatively soon. The current implementation acts 3610 ** on this hint by avoiding the use of [lookaside memory] so as not to 3611 ** deplete the limited store of lookaside memory. Future versions of 3612 ** SQLite may act on this hint differently. 3613 ** </dl> 3614 */ 3615 #define SQLITE_PREPARE_PERSISTENT 0x01 3616 3617 /* 3618 ** CAPI3REF: Compiling An SQL Statement 3619 ** KEYWORDS: {SQL statement compiler} 3620 ** METHOD: sqlite3 3621 ** CONSTRUCTOR: sqlite3_stmt 3622 ** 3623 ** To execute an SQL statement, it must first be compiled into a byte-code 3624 ** program using one of these routines. Or, in other words, these routines 3625 ** are constructors for the [prepared statement] object. 3626 ** 3627 ** The preferred routine to use is [sqlite3_prepare_v2()]. The 3628 ** [sqlite3_prepare()] interface is legacy and should be avoided. 3629 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 3630 ** for special purposes. 3631 ** 3632 ** The use of the UTF-8 interfaces is preferred, as SQLite currently 3633 ** does all parsing using UTF-8. The UTF-16 interfaces are provided 3634 ** as a convenience. The UTF-16 interfaces work by converting the 3635 ** input text into UTF-8, then invoking the corresponding UTF-8 interface. 3636 ** 3637 ** The first argument, "db", is a [database connection] obtained from a 3638 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3639 ** [sqlite3_open16()]. The database connection must not have been closed. 3640 ** 3641 ** The second argument, "zSql", is the statement to be compiled, encoded 3642 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 3643 ** and sqlite3_prepare_v3() 3644 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 3645 ** and sqlite3_prepare16_v3() use UTF-16. 3646 ** 3647 ** ^If the nByte argument is negative, then zSql is read up to the 3648 ** first zero terminator. ^If nByte is positive, then it is the 3649 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 3650 ** statement is generated. 3651 ** If the caller knows that the supplied string is nul-terminated, then 3652 ** there is a small performance advantage to passing an nByte parameter that 3653 ** is the number of bytes in the input string <i>including</i> 3654 ** the nul-terminator. 3655 ** 3656 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3657 ** past the end of the first SQL statement in zSql. These routines only 3658 ** compile the first statement in zSql, so *pzTail is left pointing to 3659 ** what remains uncompiled. 3660 ** 3661 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3662 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3663 ** to NULL. ^If the input text contains no SQL (if the input is an empty 3664 ** string or a comment) then *ppStmt is set to NULL. 3665 ** The calling procedure is responsible for deleting the compiled 3666 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 3667 ** ppStmt may not be NULL. 3668 ** 3669 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3670 ** otherwise an [error code] is returned. 3671 ** 3672 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 3673 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 3674 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 3675 ** are retained for backwards compatibility, but their use is discouraged. 3676 ** ^In the "vX" interfaces, the prepared statement 3677 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 3678 ** original SQL text. This causes the [sqlite3_step()] interface to 3679 ** behave differently in three ways: 3680 ** 3681 ** <ol> 3682 ** <li> 3683 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3684 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 3685 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3686 ** retries will occur before sqlite3_step() gives up and returns an error. 3687 ** </li> 3688 ** 3689 ** <li> 3690 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3691 ** [error codes] or [extended error codes]. ^The legacy behavior was that 3692 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3693 ** and the application would have to make a second call to [sqlite3_reset()] 3694 ** in order to find the underlying cause of the problem. With the "v2" prepare 3695 ** interfaces, the underlying reason for the error is returned immediately. 3696 ** </li> 3697 ** 3698 ** <li> 3699 ** ^If the specific value bound to [parameter | host parameter] in the 3700 ** WHERE clause might influence the choice of query plan for a statement, 3701 ** then the statement will be automatically recompiled, as if there had been 3702 ** a schema change, on the first [sqlite3_step()] call following any change 3703 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 3704 ** ^The specific value of WHERE-clause [parameter] might influence the 3705 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 3706 ** or [GLOB] operator or if the parameter is compared to an indexed column 3707 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3708 ** </li> 3709 ** </ol> 3710 ** 3711 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 3712 ** the extra prepFlags parameter, which is a bit array consisting of zero or 3713 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 3714 ** sqlite3_prepare_v2() interface works exactly the same as 3715 ** sqlite3_prepare_v3() with a zero prepFlags parameter. 3716 */ 3717 SQLITE_API int sqlite3_prepare( 3718 sqlite3 *db, /* Database handle */ 3719 const char *zSql, /* SQL statement, UTF-8 encoded */ 3720 int nByte, /* Maximum length of zSql in bytes. */ 3721 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3722 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3723 ); 3724 SQLITE_API int sqlite3_prepare_v2( 3725 sqlite3 *db, /* Database handle */ 3726 const char *zSql, /* SQL statement, UTF-8 encoded */ 3727 int nByte, /* Maximum length of zSql in bytes. */ 3728 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3729 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3730 ); 3731 SQLITE_API int sqlite3_prepare_v3( 3732 sqlite3 *db, /* Database handle */ 3733 const char *zSql, /* SQL statement, UTF-8 encoded */ 3734 int nByte, /* Maximum length of zSql in bytes. */ 3735 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3736 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3737 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3738 ); 3739 SQLITE_API int sqlite3_prepare16( 3740 sqlite3 *db, /* Database handle */ 3741 const void *zSql, /* SQL statement, UTF-16 encoded */ 3742 int nByte, /* Maximum length of zSql in bytes. */ 3743 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3744 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3745 ); 3746 SQLITE_API int sqlite3_prepare16_v2( 3747 sqlite3 *db, /* Database handle */ 3748 const void *zSql, /* SQL statement, UTF-16 encoded */ 3749 int nByte, /* Maximum length of zSql in bytes. */ 3750 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3751 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3752 ); 3753 SQLITE_API int sqlite3_prepare16_v3( 3754 sqlite3 *db, /* Database handle */ 3755 const void *zSql, /* SQL statement, UTF-16 encoded */ 3756 int nByte, /* Maximum length of zSql in bytes. */ 3757 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3758 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3759 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3760 ); 3761 3762 /* 3763 ** CAPI3REF: Retrieving Statement SQL 3764 ** METHOD: sqlite3_stmt 3765 ** 3766 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3767 ** SQL text used to create [prepared statement] P if P was 3768 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 3769 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 3770 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3771 ** string containing the SQL text of prepared statement P with 3772 ** [bound parameters] expanded. 3773 ** 3774 ** ^(For example, if a prepared statement is created using the SQL 3775 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3776 ** and parameter :xyz is unbound, then sqlite3_sql() will return 3777 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3778 ** will return "SELECT 2345,NULL".)^ 3779 ** 3780 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3781 ** is available to hold the result, or if the result would exceed the 3782 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3783 ** 3784 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3785 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3786 ** option causes sqlite3_expanded_sql() to always return NULL. 3787 ** 3788 ** ^The string returned by sqlite3_sql(P) is managed by SQLite and is 3789 ** automatically freed when the prepared statement is finalized. 3790 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3791 ** is obtained from [sqlite3_malloc()] and must be free by the application 3792 ** by passing it to [sqlite3_free()]. 3793 */ 3794 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 3795 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3796 3797 /* 3798 ** CAPI3REF: Determine If An SQL Statement Writes The Database 3799 ** METHOD: sqlite3_stmt 3800 ** 3801 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3802 ** and only if the [prepared statement] X makes no direct changes to 3803 ** the content of the database file. 3804 ** 3805 ** Note that [application-defined SQL functions] or 3806 ** [virtual tables] might change the database indirectly as a side effect. 3807 ** ^(For example, if an application defines a function "eval()" that 3808 ** calls [sqlite3_exec()], then the following SQL statement would 3809 ** change the database file through side-effects: 3810 ** 3811 ** <blockquote><pre> 3812 ** SELECT eval('DELETE FROM t1') FROM t2; 3813 ** </pre></blockquote> 3814 ** 3815 ** But because the [SELECT] statement does not change the database file 3816 ** directly, sqlite3_stmt_readonly() would still return true.)^ 3817 ** 3818 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3819 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3820 ** since the statements themselves do not actually modify the database but 3821 ** rather they control the timing of when other statements modify the 3822 ** database. ^The [ATTACH] and [DETACH] statements also cause 3823 ** sqlite3_stmt_readonly() to return true since, while those statements 3824 ** change the configuration of a database connection, they do not make 3825 ** changes to the content of the database files on disk. 3826 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 3827 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 3828 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 3829 ** sqlite3_stmt_readonly() returns false for those commands. 3830 */ 3831 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3832 3833 /* 3834 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3835 ** METHOD: sqlite3_stmt 3836 ** 3837 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3838 ** [prepared statement] S has been stepped at least once using 3839 ** [sqlite3_step(S)] but has neither run to completion (returned 3840 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3841 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3842 ** interface returns false if S is a NULL pointer. If S is not a 3843 ** NULL pointer and is not a pointer to a valid [prepared statement] 3844 ** object, then the behavior is undefined and probably undesirable. 3845 ** 3846 ** This interface can be used in combination [sqlite3_next_stmt()] 3847 ** to locate all prepared statements associated with a database 3848 ** connection that are in need of being reset. This can be used, 3849 ** for example, in diagnostic routines to search for prepared 3850 ** statements that are holding a transaction open. 3851 */ 3852 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 3853 3854 /* 3855 ** CAPI3REF: Dynamically Typed Value Object 3856 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3857 ** 3858 ** SQLite uses the sqlite3_value object to represent all values 3859 ** that can be stored in a database table. SQLite uses dynamic typing 3860 ** for the values it stores. ^Values stored in sqlite3_value objects 3861 ** can be integers, floating point values, strings, BLOBs, or NULL. 3862 ** 3863 ** An sqlite3_value object may be either "protected" or "unprotected". 3864 ** Some interfaces require a protected sqlite3_value. Other interfaces 3865 ** will accept either a protected or an unprotected sqlite3_value. 3866 ** Every interface that accepts sqlite3_value arguments specifies 3867 ** whether or not it requires a protected sqlite3_value. The 3868 ** [sqlite3_value_dup()] interface can be used to construct a new 3869 ** protected sqlite3_value from an unprotected sqlite3_value. 3870 ** 3871 ** The terms "protected" and "unprotected" refer to whether or not 3872 ** a mutex is held. An internal mutex is held for a protected 3873 ** sqlite3_value object but no mutex is held for an unprotected 3874 ** sqlite3_value object. If SQLite is compiled to be single-threaded 3875 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3876 ** or if SQLite is run in one of reduced mutex modes 3877 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3878 ** then there is no distinction between protected and unprotected 3879 ** sqlite3_value objects and they can be used interchangeably. However, 3880 ** for maximum code portability it is recommended that applications 3881 ** still make the distinction between protected and unprotected 3882 ** sqlite3_value objects even when not strictly required. 3883 ** 3884 ** ^The sqlite3_value objects that are passed as parameters into the 3885 ** implementation of [application-defined SQL functions] are protected. 3886 ** ^The sqlite3_value object returned by 3887 ** [sqlite3_column_value()] is unprotected. 3888 ** Unprotected sqlite3_value objects may only be used as arguments 3889 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and 3890 ** [sqlite3_value_dup()]. 3891 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 3892 ** interfaces require protected sqlite3_value objects. 3893 */ 3894 typedef struct sqlite3_value sqlite3_value; 3895 3896 /* 3897 ** CAPI3REF: SQL Function Context Object 3898 ** 3899 ** The context in which an SQL function executes is stored in an 3900 ** sqlite3_context object. ^A pointer to an sqlite3_context object 3901 ** is always first parameter to [application-defined SQL functions]. 3902 ** The application-defined SQL function implementation will pass this 3903 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3904 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3905 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3906 ** and/or [sqlite3_set_auxdata()]. 3907 */ 3908 typedef struct sqlite3_context sqlite3_context; 3909 3910 /* 3911 ** CAPI3REF: Binding Values To Prepared Statements 3912 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3913 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3914 ** METHOD: sqlite3_stmt 3915 ** 3916 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3917 ** literals may be replaced by a [parameter] that matches one of following 3918 ** templates: 3919 ** 3920 ** <ul> 3921 ** <li> ? 3922 ** <li> ?NNN 3923 ** <li> :VVV 3924 ** <li> @VVV 3925 ** <li> $VVV 3926 ** </ul> 3927 ** 3928 ** In the templates above, NNN represents an integer literal, 3929 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 3930 ** parameters (also called "host parameter names" or "SQL parameters") 3931 ** can be set using the sqlite3_bind_*() routines defined here. 3932 ** 3933 ** ^The first argument to the sqlite3_bind_*() routines is always 3934 ** a pointer to the [sqlite3_stmt] object returned from 3935 ** [sqlite3_prepare_v2()] or its variants. 3936 ** 3937 ** ^The second argument is the index of the SQL parameter to be set. 3938 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 3939 ** SQL parameter is used more than once, second and subsequent 3940 ** occurrences have the same index as the first occurrence. 3941 ** ^The index for named parameters can be looked up using the 3942 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 3943 ** for "?NNN" parameters is the value of NNN. 3944 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 3945 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3946 ** 3947 ** ^The third argument is the value to bind to the parameter. 3948 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3949 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3950 ** is ignored and the end result is the same as sqlite3_bind_null(). 3951 ** 3952 ** ^(In those routines that have a fourth argument, its value is the 3953 ** number of bytes in the parameter. To be clear: the value is the 3954 ** number of <u>bytes</u> in the value, not the number of characters.)^ 3955 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3956 ** is negative, then the length of the string is 3957 ** the number of bytes up to the first zero terminator. 3958 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 3959 ** the behavior is undefined. 3960 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3961 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3962 ** that parameter must be the byte offset 3963 ** where the NUL terminator would occur assuming the string were NUL 3964 ** terminated. If any NUL characters occur at byte offsets less than 3965 ** the value of the fourth parameter then the resulting string value will 3966 ** contain embedded NULs. The result of expressions involving strings 3967 ** with embedded NULs is undefined. 3968 ** 3969 ** ^The fifth argument to the BLOB and string binding interfaces 3970 ** is a destructor used to dispose of the BLOB or 3971 ** string after SQLite has finished with it. ^The destructor is called 3972 ** to dispose of the BLOB or string even if the call to bind API fails. 3973 ** ^If the fifth argument is 3974 ** the special value [SQLITE_STATIC], then SQLite assumes that the 3975 ** information is in static, unmanaged space and does not need to be freed. 3976 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3977 ** SQLite makes its own private copy of the data immediately, before 3978 ** the sqlite3_bind_*() routine returns. 3979 ** 3980 ** ^The sixth argument to sqlite3_bind_text64() must be one of 3981 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3982 ** to specify the encoding of the text in the third parameter. If 3983 ** the sixth argument to sqlite3_bind_text64() is not one of the 3984 ** allowed values shown above, or if the text encoding is different 3985 ** from the encoding specified by the sixth parameter, then the behavior 3986 ** is undefined. 3987 ** 3988 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3989 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3990 ** (just an integer to hold its size) while it is being processed. 3991 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 3992 ** content is later written using 3993 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 3994 ** ^A negative value for the zeroblob results in a zero-length BLOB. 3995 ** 3996 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 3997 ** [prepared statement] S to have an SQL value of NULL, but to also be 3998 ** associated with the pointer P of type T. ^D is either a NULL pointer or 3999 ** a pointer to a destructor function for P. ^SQLite will invoke the 4000 ** destructor D with a single argument of P when it is finished using 4001 ** P. The T parameter should be a static string, preferably a string 4002 ** literal. The sqlite3_bind_pointer() routine is part of the 4003 ** [pointer passing interface] added for SQLite 3.20.0. 4004 ** 4005 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4006 ** for the [prepared statement] or with a prepared statement for which 4007 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4008 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4009 ** routine is passed a [prepared statement] that has been finalized, the 4010 ** result is undefined and probably harmful. 4011 ** 4012 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4013 ** ^Unbound parameters are interpreted as NULL. 4014 ** 4015 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4016 ** [error code] if anything goes wrong. 4017 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4018 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4019 ** [SQLITE_MAX_LENGTH]. 4020 ** ^[SQLITE_RANGE] is returned if the parameter 4021 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4022 ** 4023 ** See also: [sqlite3_bind_parameter_count()], 4024 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4025 */ 4026 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4027 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4028 void(*)(void*)); 4029 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 4030 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 4031 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4032 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 4033 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4034 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4035 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4036 void(*)(void*), unsigned char encoding); 4037 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4038 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4039 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4040 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4041 4042 /* 4043 ** CAPI3REF: Number Of SQL Parameters 4044 ** METHOD: sqlite3_stmt 4045 ** 4046 ** ^This routine can be used to find the number of [SQL parameters] 4047 ** in a [prepared statement]. SQL parameters are tokens of the 4048 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4049 ** placeholders for values that are [sqlite3_bind_blob | bound] 4050 ** to the parameters at a later time. 4051 ** 4052 ** ^(This routine actually returns the index of the largest (rightmost) 4053 ** parameter. For all forms except ?NNN, this will correspond to the 4054 ** number of unique parameters. If parameters of the ?NNN form are used, 4055 ** there may be gaps in the list.)^ 4056 ** 4057 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4058 ** [sqlite3_bind_parameter_name()], and 4059 ** [sqlite3_bind_parameter_index()]. 4060 */ 4061 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 4062 4063 /* 4064 ** CAPI3REF: Name Of A Host Parameter 4065 ** METHOD: sqlite3_stmt 4066 ** 4067 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 4068 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 4069 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4070 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4071 ** respectively. 4072 ** In other words, the initial ":" or "$" or "@" or "?" 4073 ** is included as part of the name.)^ 4074 ** ^Parameters of the form "?" without a following integer have no name 4075 ** and are referred to as "nameless" or "anonymous parameters". 4076 ** 4077 ** ^The first host parameter has an index of 1, not 0. 4078 ** 4079 ** ^If the value N is out of range or if the N-th parameter is 4080 ** nameless, then NULL is returned. ^The returned string is 4081 ** always in UTF-8 encoding even if the named parameter was 4082 ** originally specified as UTF-16 in [sqlite3_prepare16()], 4083 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4084 ** 4085 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4086 ** [sqlite3_bind_parameter_count()], and 4087 ** [sqlite3_bind_parameter_index()]. 4088 */ 4089 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4090 4091 /* 4092 ** CAPI3REF: Index Of A Parameter With A Given Name 4093 ** METHOD: sqlite3_stmt 4094 ** 4095 ** ^Return the index of an SQL parameter given its name. ^The 4096 ** index value returned is suitable for use as the second 4097 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4098 ** is returned if no matching parameter is found. ^The parameter 4099 ** name must be given in UTF-8 even if the original statement 4100 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4101 ** [sqlite3_prepare16_v3()]. 4102 ** 4103 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4104 ** [sqlite3_bind_parameter_count()], and 4105 ** [sqlite3_bind_parameter_name()]. 4106 */ 4107 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4108 4109 /* 4110 ** CAPI3REF: Reset All Bindings On A Prepared Statement 4111 ** METHOD: sqlite3_stmt 4112 ** 4113 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4114 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4115 ** ^Use this routine to reset all host parameters to NULL. 4116 */ 4117 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4118 4119 /* 4120 ** CAPI3REF: Number Of Columns In A Result Set 4121 ** METHOD: sqlite3_stmt 4122 ** 4123 ** ^Return the number of columns in the result set returned by the 4124 ** [prepared statement]. ^If this routine returns 0, that means the 4125 ** [prepared statement] returns no data (for example an [UPDATE]). 4126 ** ^However, just because this routine returns a positive number does not 4127 ** mean that one or more rows of data will be returned. ^A SELECT statement 4128 ** will always have a positive sqlite3_column_count() but depending on the 4129 ** WHERE clause constraints and the table content, it might return no rows. 4130 ** 4131 ** See also: [sqlite3_data_count()] 4132 */ 4133 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 4134 4135 /* 4136 ** CAPI3REF: Column Names In A Result Set 4137 ** METHOD: sqlite3_stmt 4138 ** 4139 ** ^These routines return the name assigned to a particular column 4140 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4141 ** interface returns a pointer to a zero-terminated UTF-8 string 4142 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 4143 ** UTF-16 string. ^The first parameter is the [prepared statement] 4144 ** that implements the [SELECT] statement. ^The second parameter is the 4145 ** column number. ^The leftmost column is number 0. 4146 ** 4147 ** ^The returned string pointer is valid until either the [prepared statement] 4148 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4149 ** reprepared by the first call to [sqlite3_step()] for a particular run 4150 ** or until the next call to 4151 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4152 ** 4153 ** ^If sqlite3_malloc() fails during the processing of either routine 4154 ** (for example during a conversion from UTF-8 to UTF-16) then a 4155 ** NULL pointer is returned. 4156 ** 4157 ** ^The name of a result column is the value of the "AS" clause for 4158 ** that column, if there is an AS clause. If there is no AS clause 4159 ** then the name of the column is unspecified and may change from 4160 ** one release of SQLite to the next. 4161 */ 4162 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4163 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4164 4165 /* 4166 ** CAPI3REF: Source Of Data In A Query Result 4167 ** METHOD: sqlite3_stmt 4168 ** 4169 ** ^These routines provide a means to determine the database, table, and 4170 ** table column that is the origin of a particular result column in 4171 ** [SELECT] statement. 4172 ** ^The name of the database or table or column can be returned as 4173 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4174 ** the database name, the _table_ routines return the table name, and 4175 ** the origin_ routines return the column name. 4176 ** ^The returned string is valid until the [prepared statement] is destroyed 4177 ** using [sqlite3_finalize()] or until the statement is automatically 4178 ** reprepared by the first call to [sqlite3_step()] for a particular run 4179 ** or until the same information is requested 4180 ** again in a different encoding. 4181 ** 4182 ** ^The names returned are the original un-aliased names of the 4183 ** database, table, and column. 4184 ** 4185 ** ^The first argument to these interfaces is a [prepared statement]. 4186 ** ^These functions return information about the Nth result column returned by 4187 ** the statement, where N is the second function argument. 4188 ** ^The left-most column is column 0 for these routines. 4189 ** 4190 ** ^If the Nth column returned by the statement is an expression or 4191 ** subquery and is not a column value, then all of these functions return 4192 ** NULL. ^These routine might also return NULL if a memory allocation error 4193 ** occurs. ^Otherwise, they return the name of the attached database, table, 4194 ** or column that query result column was extracted from. 4195 ** 4196 ** ^As with all other SQLite APIs, those whose names end with "16" return 4197 ** UTF-16 encoded strings and the other functions return UTF-8. 4198 ** 4199 ** ^These APIs are only available if the library was compiled with the 4200 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4201 ** 4202 ** If two or more threads call one or more of these routines against the same 4203 ** prepared statement and column at the same time then the results are 4204 ** undefined. 4205 ** 4206 ** If two or more threads call one or more 4207 ** [sqlite3_column_database_name | column metadata interfaces] 4208 ** for the same [prepared statement] and result column 4209 ** at the same time then the results are undefined. 4210 */ 4211 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4212 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4213 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4214 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4215 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4216 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4217 4218 /* 4219 ** CAPI3REF: Declared Datatype Of A Query Result 4220 ** METHOD: sqlite3_stmt 4221 ** 4222 ** ^(The first parameter is a [prepared statement]. 4223 ** If this statement is a [SELECT] statement and the Nth column of the 4224 ** returned result set of that [SELECT] is a table column (not an 4225 ** expression or subquery) then the declared type of the table 4226 ** column is returned.)^ ^If the Nth column of the result set is an 4227 ** expression or subquery, then a NULL pointer is returned. 4228 ** ^The returned string is always UTF-8 encoded. 4229 ** 4230 ** ^(For example, given the database schema: 4231 ** 4232 ** CREATE TABLE t1(c1 VARIANT); 4233 ** 4234 ** and the following statement to be compiled: 4235 ** 4236 ** SELECT c1 + 1, c1 FROM t1; 4237 ** 4238 ** this routine would return the string "VARIANT" for the second result 4239 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4240 ** 4241 ** ^SQLite uses dynamic run-time typing. ^So just because a column 4242 ** is declared to contain a particular type does not mean that the 4243 ** data stored in that column is of the declared type. SQLite is 4244 ** strongly typed, but the typing is dynamic not static. ^Type 4245 ** is associated with individual values, not with the containers 4246 ** used to hold those values. 4247 */ 4248 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4249 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4250 4251 /* 4252 ** CAPI3REF: Evaluate An SQL Statement 4253 ** METHOD: sqlite3_stmt 4254 ** 4255 ** After a [prepared statement] has been prepared using any of 4256 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4257 ** or [sqlite3_prepare16_v3()] or one of the legacy 4258 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4259 ** must be called one or more times to evaluate the statement. 4260 ** 4261 ** The details of the behavior of the sqlite3_step() interface depend 4262 ** on whether the statement was prepared using the newer "vX" interfaces 4263 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4264 ** [sqlite3_prepare16_v2()] or the older legacy 4265 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4266 ** new "vX" interface is recommended for new applications but the legacy 4267 ** interface will continue to be supported. 4268 ** 4269 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4270 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4271 ** ^With the "v2" interface, any of the other [result codes] or 4272 ** [extended result codes] might be returned as well. 4273 ** 4274 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4275 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 4276 ** or occurs outside of an explicit transaction, then you can retry the 4277 ** statement. If the statement is not a [COMMIT] and occurs within an 4278 ** explicit transaction then you should rollback the transaction before 4279 ** continuing. 4280 ** 4281 ** ^[SQLITE_DONE] means that the statement has finished executing 4282 ** successfully. sqlite3_step() should not be called again on this virtual 4283 ** machine without first calling [sqlite3_reset()] to reset the virtual 4284 ** machine back to its initial state. 4285 ** 4286 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4287 ** is returned each time a new row of data is ready for processing by the 4288 ** caller. The values may be accessed using the [column access functions]. 4289 ** sqlite3_step() is called again to retrieve the next row of data. 4290 ** 4291 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4292 ** violation) has occurred. sqlite3_step() should not be called again on 4293 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 4294 ** ^With the legacy interface, a more specific error code (for example, 4295 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4296 ** can be obtained by calling [sqlite3_reset()] on the 4297 ** [prepared statement]. ^In the "v2" interface, 4298 ** the more specific error code is returned directly by sqlite3_step(). 4299 ** 4300 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4301 ** Perhaps it was called on a [prepared statement] that has 4302 ** already been [sqlite3_finalize | finalized] or on one that had 4303 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4304 ** be the case that the same database connection is being used by two or 4305 ** more threads at the same moment in time. 4306 ** 4307 ** For all versions of SQLite up to and including 3.6.23.1, a call to 4308 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 4309 ** other than [SQLITE_ROW] before any subsequent invocation of 4310 ** sqlite3_step(). Failure to reset the prepared statement using 4311 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4312 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4313 ** sqlite3_step() began 4314 ** calling [sqlite3_reset()] automatically in this circumstance rather 4315 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4316 ** break because any application that ever receives an SQLITE_MISUSE error 4317 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4318 ** can be used to restore the legacy behavior. 4319 ** 4320 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4321 ** API always returns a generic error code, [SQLITE_ERROR], following any 4322 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4323 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4324 ** specific [error codes] that better describes the error. 4325 ** We admit that this is a goofy design. The problem has been fixed 4326 ** with the "v2" interface. If you prepare all of your SQL statements 4327 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4328 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4329 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4330 ** then the more specific [error codes] are returned directly 4331 ** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4332 */ 4333 SQLITE_API int sqlite3_step(sqlite3_stmt*); 4334 4335 /* 4336 ** CAPI3REF: Number of columns in a result set 4337 ** METHOD: sqlite3_stmt 4338 ** 4339 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 4340 ** current row of the result set of [prepared statement] P. 4341 ** ^If prepared statement P does not have results ready to return 4342 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 4343 ** interfaces) then sqlite3_data_count(P) returns 0. 4344 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4345 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4346 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4347 ** will return non-zero if previous call to [sqlite3_step](P) returned 4348 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4349 ** where it always returns zero since each step of that multi-step 4350 ** pragma returns 0 columns of data. 4351 ** 4352 ** See also: [sqlite3_column_count()] 4353 */ 4354 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4355 4356 /* 4357 ** CAPI3REF: Fundamental Datatypes 4358 ** KEYWORDS: SQLITE_TEXT 4359 ** 4360 ** ^(Every value in SQLite has one of five fundamental datatypes: 4361 ** 4362 ** <ul> 4363 ** <li> 64-bit signed integer 4364 ** <li> 64-bit IEEE floating point number 4365 ** <li> string 4366 ** <li> BLOB 4367 ** <li> NULL 4368 ** </ul>)^ 4369 ** 4370 ** These constants are codes for each of those types. 4371 ** 4372 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4373 ** for a completely different meaning. Software that links against both 4374 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4375 ** SQLITE_TEXT. 4376 */ 4377 #define SQLITE_INTEGER 1 4378 #define SQLITE_FLOAT 2 4379 #define SQLITE_BLOB 4 4380 #define SQLITE_NULL 5 4381 #ifdef SQLITE_TEXT 4382 # undef SQLITE_TEXT 4383 #else 4384 # define SQLITE_TEXT 3 4385 #endif 4386 #define SQLITE3_TEXT 3 4387 4388 /* 4389 ** CAPI3REF: Result Values From A Query 4390 ** KEYWORDS: {column access functions} 4391 ** METHOD: sqlite3_stmt 4392 ** 4393 ** <b>Summary:</b> 4394 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4395 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4396 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4397 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4398 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4399 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4400 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4401 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4402 ** [sqlite3_value|unprotected sqlite3_value] object. 4403 ** <tr><td> <td> <td> 4404 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4405 ** or a UTF-8 TEXT result in bytes 4406 ** <tr><td><b>sqlite3_column_bytes16 </b> 4407 ** <td>→ <td>Size of UTF-16 4408 ** TEXT in bytes 4409 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4410 ** datatype of the result 4411 ** </table></blockquote> 4412 ** 4413 ** <b>Details:</b> 4414 ** 4415 ** ^These routines return information about a single column of the current 4416 ** result row of a query. ^In every case the first argument is a pointer 4417 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4418 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4419 ** and the second argument is the index of the column for which information 4420 ** should be returned. ^The leftmost column of the result set has the index 0. 4421 ** ^The number of columns in the result can be determined using 4422 ** [sqlite3_column_count()]. 4423 ** 4424 ** If the SQL statement does not currently point to a valid row, or if the 4425 ** column index is out of range, the result is undefined. 4426 ** These routines may only be called when the most recent call to 4427 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4428 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4429 ** If any of these routines are called after [sqlite3_reset()] or 4430 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4431 ** something other than [SQLITE_ROW], the results are undefined. 4432 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4433 ** are called from a different thread while any of these routines 4434 ** are pending, then the results are undefined. 4435 ** 4436 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4437 ** each return the value of a result column in a specific data format. If 4438 ** the result column is not initially in the requested format (for example, 4439 ** if the query returns an integer but the sqlite3_column_text() interface 4440 ** is used to extract the value) then an automatic type conversion is performed. 4441 ** 4442 ** ^The sqlite3_column_type() routine returns the 4443 ** [SQLITE_INTEGER | datatype code] for the initial data type 4444 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4445 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4446 ** The return value of sqlite3_column_type() can be used to decide which 4447 ** of the first six interface should be used to extract the column value. 4448 ** The value returned by sqlite3_column_type() is only meaningful if no 4449 ** automatic type conversions have occurred for the value in question. 4450 ** After a type conversion, the result of calling sqlite3_column_type() 4451 ** is undefined, though harmless. Future 4452 ** versions of SQLite may change the behavior of sqlite3_column_type() 4453 ** following a type conversion. 4454 ** 4455 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4456 ** or sqlite3_column_bytes16() interfaces can be used to determine the size 4457 ** of that BLOB or string. 4458 ** 4459 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4460 ** routine returns the number of bytes in that BLOB or string. 4461 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4462 ** the string to UTF-8 and then returns the number of bytes. 4463 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 4464 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4465 ** the number of bytes in that string. 4466 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4467 ** 4468 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4469 ** routine returns the number of bytes in that BLOB or string. 4470 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4471 ** the string to UTF-16 and then returns the number of bytes. 4472 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4473 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4474 ** the number of bytes in that string. 4475 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4476 ** 4477 ** ^The values returned by [sqlite3_column_bytes()] and 4478 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4479 ** of the string. ^For clarity: the values returned by 4480 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4481 ** bytes in the string, not the number of characters. 4482 ** 4483 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4484 ** even empty strings, are always zero-terminated. ^The return 4485 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4486 ** 4487 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4488 ** [unprotected sqlite3_value] object. In a multithreaded environment, 4489 ** an unprotected sqlite3_value object may only be used safely with 4490 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4491 ** If the [unprotected sqlite3_value] object returned by 4492 ** [sqlite3_column_value()] is used in any other way, including calls 4493 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4494 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4495 ** Hence, the sqlite3_column_value() interface 4496 ** is normally only useful within the implementation of 4497 ** [application-defined SQL functions] or [virtual tables], not within 4498 ** top-level application code. 4499 ** 4500 ** The these routines may attempt to convert the datatype of the result. 4501 ** ^For example, if the internal representation is FLOAT and a text result 4502 ** is requested, [sqlite3_snprintf()] is used internally to perform the 4503 ** conversion automatically. ^(The following table details the conversions 4504 ** that are applied: 4505 ** 4506 ** <blockquote> 4507 ** <table border="1"> 4508 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4509 ** 4510 ** <tr><td> NULL <td> INTEGER <td> Result is 0 4511 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4512 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4513 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4514 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4515 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4516 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4517 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4518 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4519 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4520 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4521 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4522 ** <tr><td> TEXT <td> BLOB <td> No change 4523 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4524 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4525 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4526 ** </table> 4527 ** </blockquote>)^ 4528 ** 4529 ** Note that when type conversions occur, pointers returned by prior 4530 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4531 ** sqlite3_column_text16() may be invalidated. 4532 ** Type conversions and pointer invalidations might occur 4533 ** in the following cases: 4534 ** 4535 ** <ul> 4536 ** <li> The initial content is a BLOB and sqlite3_column_text() or 4537 ** sqlite3_column_text16() is called. A zero-terminator might 4538 ** need to be added to the string.</li> 4539 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4540 ** sqlite3_column_text16() is called. The content must be converted 4541 ** to UTF-16.</li> 4542 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4543 ** sqlite3_column_text() is called. The content must be converted 4544 ** to UTF-8.</li> 4545 ** </ul> 4546 ** 4547 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4548 ** not invalidate a prior pointer, though of course the content of the buffer 4549 ** that the prior pointer references will have been modified. Other kinds 4550 ** of conversion are done in place when it is possible, but sometimes they 4551 ** are not possible and in those cases prior pointers are invalidated. 4552 ** 4553 ** The safest policy is to invoke these routines 4554 ** in one of the following ways: 4555 ** 4556 ** <ul> 4557 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4558 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4559 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4560 ** </ul> 4561 ** 4562 ** In other words, you should call sqlite3_column_text(), 4563 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4564 ** into the desired format, then invoke sqlite3_column_bytes() or 4565 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4566 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4567 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4568 ** with calls to sqlite3_column_bytes(). 4569 ** 4570 ** ^The pointers returned are valid until a type conversion occurs as 4571 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4572 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4573 ** and BLOBs is freed automatically. Do not pass the pointers returned 4574 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4575 ** [sqlite3_free()]. 4576 ** 4577 ** As long as the input parameters are correct, these routines will only 4578 ** fail if an out-of-memory error occurs during a format conversion. 4579 ** Only the following subset of interfaces are subject to out-of-memory 4580 ** errors: 4581 ** 4582 ** <ul> 4583 ** <li> sqlite3_column_blob() 4584 ** <li> sqlite3_column_text() 4585 ** <li> sqlite3_column_text16() 4586 ** <li> sqlite3_column_bytes() 4587 ** <li> sqlite3_column_bytes16() 4588 ** </ul> 4589 ** 4590 ** If an out-of-memory error occurs, then the return value from these 4591 ** routines is the same as if the column had contained an SQL NULL value. 4592 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 4593 ** by invoking the [sqlite3_errcode()] immediately after the suspect 4594 ** return value is obtained and before any 4595 ** other SQLite interface is called on the same [database connection]. 4596 */ 4597 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4598 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 4599 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 4600 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4601 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4602 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4603 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4604 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4605 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4606 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 4607 4608 /* 4609 ** CAPI3REF: Destroy A Prepared Statement Object 4610 ** DESTRUCTOR: sqlite3_stmt 4611 ** 4612 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4613 ** ^If the most recent evaluation of the statement encountered no errors 4614 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 4615 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4616 ** sqlite3_finalize(S) returns the appropriate [error code] or 4617 ** [extended error code]. 4618 ** 4619 ** ^The sqlite3_finalize(S) routine can be called at any point during 4620 ** the life cycle of [prepared statement] S: 4621 ** before statement S is ever evaluated, after 4622 ** one or more calls to [sqlite3_reset()], or after any call 4623 ** to [sqlite3_step()] regardless of whether or not the statement has 4624 ** completed execution. 4625 ** 4626 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4627 ** 4628 ** The application must finalize every [prepared statement] in order to avoid 4629 ** resource leaks. It is a grievous error for the application to try to use 4630 ** a prepared statement after it has been finalized. Any use of a prepared 4631 ** statement after it has been finalized can result in undefined and 4632 ** undesirable behavior such as segfaults and heap corruption. 4633 */ 4634 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 4635 4636 /* 4637 ** CAPI3REF: Reset A Prepared Statement Object 4638 ** METHOD: sqlite3_stmt 4639 ** 4640 ** The sqlite3_reset() function is called to reset a [prepared statement] 4641 ** object back to its initial state, ready to be re-executed. 4642 ** ^Any SQL statement variables that had values bound to them using 4643 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4644 ** Use [sqlite3_clear_bindings()] to reset the bindings. 4645 ** 4646 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4647 ** back to the beginning of its program. 4648 ** 4649 ** ^If the most recent call to [sqlite3_step(S)] for the 4650 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4651 ** or if [sqlite3_step(S)] has never before been called on S, 4652 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4653 ** 4654 ** ^If the most recent call to [sqlite3_step(S)] for the 4655 ** [prepared statement] S indicated an error, then 4656 ** [sqlite3_reset(S)] returns an appropriate [error code]. 4657 ** 4658 ** ^The [sqlite3_reset(S)] interface does not change the values 4659 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4660 */ 4661 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 4662 4663 /* 4664 ** CAPI3REF: Create Or Redefine SQL Functions 4665 ** KEYWORDS: {function creation routines} 4666 ** KEYWORDS: {application-defined SQL function} 4667 ** KEYWORDS: {application-defined SQL functions} 4668 ** METHOD: sqlite3 4669 ** 4670 ** ^These functions (collectively known as "function creation routines") 4671 ** are used to add SQL functions or aggregates or to redefine the behavior 4672 ** of existing SQL functions or aggregates. The only differences between 4673 ** the three "sqlite3_create_function*" routines are the text encoding 4674 ** expected for the second parameter (the name of the function being 4675 ** created) and the presence or absence of a destructor callback for 4676 ** the application data pointer. Function sqlite3_create_window_function() 4677 ** is similar, but allows the user to supply the extra callback functions 4678 ** needed by [aggregate window functions]. 4679 ** 4680 ** ^The first parameter is the [database connection] to which the SQL 4681 ** function is to be added. ^If an application uses more than one database 4682 ** connection then application-defined SQL functions must be added 4683 ** to each database connection separately. 4684 ** 4685 ** ^The second parameter is the name of the SQL function to be created or 4686 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4687 ** representation, exclusive of the zero-terminator. ^Note that the name 4688 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4689 ** ^Any attempt to create a function with a longer name 4690 ** will result in [SQLITE_MISUSE] being returned. 4691 ** 4692 ** ^The third parameter (nArg) 4693 ** is the number of arguments that the SQL function or 4694 ** aggregate takes. ^If this parameter is -1, then the SQL function or 4695 ** aggregate may take any number of arguments between 0 and the limit 4696 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4697 ** parameter is less than -1 or greater than 127 then the behavior is 4698 ** undefined. 4699 ** 4700 ** ^The fourth parameter, eTextRep, specifies what 4701 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4702 ** its parameters. The application should set this parameter to 4703 ** [SQLITE_UTF16LE] if the function implementation invokes 4704 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4705 ** implementation invokes [sqlite3_value_text16be()] on an input, or 4706 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4707 ** otherwise. ^The same SQL function may be registered multiple times using 4708 ** different preferred text encodings, with different implementations for 4709 ** each encoding. 4710 ** ^When multiple implementations of the same function are available, SQLite 4711 ** will pick the one that involves the least amount of data conversion. 4712 ** 4713 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4714 ** to signal that the function will always return the same result given 4715 ** the same inputs within a single SQL statement. Most SQL functions are 4716 ** deterministic. The built-in [random()] SQL function is an example of a 4717 ** function that is not deterministic. The SQLite query planner is able to 4718 ** perform additional optimizations on deterministic functions, so use 4719 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4720 ** 4721 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4722 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 4723 ** 4724 ** ^The sixth, seventh and eighth parameters passed to the three 4725 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 4726 ** pointers to C-language functions that implement the SQL function or 4727 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4728 ** callback only; NULL pointers must be passed as the xStep and xFinal 4729 ** parameters. ^An aggregate SQL function requires an implementation of xStep 4730 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4731 ** SQL function or aggregate, pass NULL pointers for all three function 4732 ** callbacks. 4733 ** 4734 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 4735 ** and xInverse) passed to sqlite3_create_window_function are pointers to 4736 ** C-language callbacks that implement the new function. xStep and xFinal 4737 ** must both be non-NULL. xValue and xInverse may either both be NULL, in 4738 ** which case a regular aggregate function is created, or must both be 4739 ** non-NULL, in which case the new function may be used as either an aggregate 4740 ** or aggregate window function. More details regarding the implementation 4741 ** of aggregate window functions are 4742 ** [user-defined window functions|available here]. 4743 ** 4744 ** ^(If the final parameter to sqlite3_create_function_v2() or 4745 ** sqlite3_create_window_function() is not NULL, then it is destructor for 4746 ** the application data pointer. The destructor is invoked when the function 4747 ** is deleted, either by being overloaded or when the database connection 4748 ** closes.)^ ^The destructor is also invoked if the call to 4749 ** sqlite3_create_function_v2() fails. ^When the destructor callback is 4750 ** invoked, it is passed a single argument which is a copy of the application 4751 ** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 4752 ** 4753 ** ^It is permitted to register multiple implementations of the same 4754 ** functions with the same name but with either differing numbers of 4755 ** arguments or differing preferred text encodings. ^SQLite will use 4756 ** the implementation that most closely matches the way in which the 4757 ** SQL function is used. ^A function implementation with a non-negative 4758 ** nArg parameter is a better match than a function implementation with 4759 ** a negative nArg. ^A function where the preferred text encoding 4760 ** matches the database encoding is a better 4761 ** match than a function where the encoding is different. 4762 ** ^A function where the encoding difference is between UTF16le and UTF16be 4763 ** is a closer match than a function where the encoding difference is 4764 ** between UTF8 and UTF16. 4765 ** 4766 ** ^Built-in functions may be overloaded by new application-defined functions. 4767 ** 4768 ** ^An application-defined function is permitted to call other 4769 ** SQLite interfaces. However, such calls must not 4770 ** close the database connection nor finalize or reset the prepared 4771 ** statement in which the function is running. 4772 */ 4773 SQLITE_API int sqlite3_create_function( 4774 sqlite3 *db, 4775 const char *zFunctionName, 4776 int nArg, 4777 int eTextRep, 4778 void *pApp, 4779 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4780 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4781 void (*xFinal)(sqlite3_context*) 4782 ); 4783 SQLITE_API int sqlite3_create_function16( 4784 sqlite3 *db, 4785 const void *zFunctionName, 4786 int nArg, 4787 int eTextRep, 4788 void *pApp, 4789 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4790 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4791 void (*xFinal)(sqlite3_context*) 4792 ); 4793 SQLITE_API int sqlite3_create_function_v2( 4794 sqlite3 *db, 4795 const char *zFunctionName, 4796 int nArg, 4797 int eTextRep, 4798 void *pApp, 4799 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4800 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4801 void (*xFinal)(sqlite3_context*), 4802 void(*xDestroy)(void*) 4803 ); 4804 SQLITE_API int sqlite3_create_window_function( 4805 sqlite3 *db, 4806 const char *zFunctionName, 4807 int nArg, 4808 int eTextRep, 4809 void *pApp, 4810 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4811 void (*xFinal)(sqlite3_context*), 4812 void (*xValue)(sqlite3_context*), 4813 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 4814 void(*xDestroy)(void*) 4815 ); 4816 4817 /* 4818 ** CAPI3REF: Text Encodings 4819 ** 4820 ** These constant define integer codes that represent the various 4821 ** text encodings supported by SQLite. 4822 */ 4823 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4824 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4825 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4826 #define SQLITE_UTF16 4 /* Use native byte order */ 4827 #define SQLITE_ANY 5 /* Deprecated */ 4828 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4829 4830 /* 4831 ** CAPI3REF: Function Flags 4832 ** 4833 ** These constants may be ORed together with the 4834 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4835 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4836 ** [sqlite3_create_function_v2()]. 4837 */ 4838 #define SQLITE_DETERMINISTIC 0x800 4839 4840 /* 4841 ** CAPI3REF: Deprecated Functions 4842 ** DEPRECATED 4843 ** 4844 ** These functions are [deprecated]. In order to maintain 4845 ** backwards compatibility with older code, these functions continue 4846 ** to be supported. However, new applications should avoid 4847 ** the use of these functions. To encourage programmers to avoid 4848 ** these functions, we will not explain what they do. 4849 */ 4850 #ifndef SQLITE_OMIT_DEPRECATED 4851 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4852 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4853 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4854 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 4855 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4856 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4857 void*,sqlite3_int64); 4858 #endif 4859 4860 /* 4861 ** CAPI3REF: Obtaining SQL Values 4862 ** METHOD: sqlite3_value 4863 ** 4864 ** <b>Summary:</b> 4865 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4866 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 4867 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 4868 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 4869 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 4870 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 4871 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 4872 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 4873 ** the native byteorder 4874 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 4875 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 4876 ** <tr><td> <td> <td> 4877 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 4878 ** or a UTF-8 TEXT in bytes 4879 ** <tr><td><b>sqlite3_value_bytes16 </b> 4880 ** <td>→ <td>Size of UTF-16 4881 ** TEXT in bytes 4882 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 4883 ** datatype of the value 4884 ** <tr><td><b>sqlite3_value_numeric_type </b> 4885 ** <td>→ <td>Best numeric datatype of the value 4886 ** <tr><td><b>sqlite3_value_nochange </b> 4887 ** <td>→ <td>True if the column is unchanged in an UPDATE 4888 ** against a virtual table. 4889 ** </table></blockquote> 4890 ** 4891 ** <b>Details:</b> 4892 ** 4893 ** These routines extract type, size, and content information from 4894 ** [protected sqlite3_value] objects. Protected sqlite3_value objects 4895 ** are used to pass parameter information into implementation of 4896 ** [application-defined SQL functions] and [virtual tables]. 4897 ** 4898 ** These routines work only with [protected sqlite3_value] objects. 4899 ** Any attempt to use these routines on an [unprotected sqlite3_value] 4900 ** is not threadsafe. 4901 ** 4902 ** ^These routines work just like the corresponding [column access functions] 4903 ** except that these routines take a single [protected sqlite3_value] object 4904 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4905 ** 4906 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4907 ** in the native byte-order of the host machine. ^The 4908 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4909 ** extract UTF-16 strings as big-endian and little-endian respectively. 4910 ** 4911 ** ^If [sqlite3_value] object V was initialized 4912 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 4913 ** and if X and Y are strings that compare equal according to strcmp(X,Y), 4914 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 4915 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 4916 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 4917 ** 4918 ** ^(The sqlite3_value_type(V) interface returns the 4919 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the 4920 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 4921 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 4922 ** Other interfaces might change the datatype for an sqlite3_value object. 4923 ** For example, if the datatype is initially SQLITE_INTEGER and 4924 ** sqlite3_value_text(V) is called to extract a text value for that 4925 ** integer, then subsequent calls to sqlite3_value_type(V) might return 4926 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 4927 ** occurs is undefined and may change from one release of SQLite to the next. 4928 ** 4929 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 4930 ** numeric affinity to the value. This means that an attempt is 4931 ** made to convert the value to an integer or floating point. If 4932 ** such a conversion is possible without loss of information (in other 4933 ** words, if the value is a string that looks like a number) 4934 ** then the conversion is performed. Otherwise no conversion occurs. 4935 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4936 ** 4937 ** ^Within the [xUpdate] method of a [virtual table], the 4938 ** sqlite3_value_nochange(X) interface returns true if and only if 4939 ** the column corresponding to X is unchanged by the UPDATE operation 4940 ** that the xUpdate method call was invoked to implement and if 4941 ** and the prior [xColumn] method call that was invoked to extracted 4942 ** the value for that column returned without setting a result (probably 4943 ** because it queried [sqlite3_vtab_nochange()] and found that the column 4944 ** was unchanging). ^Within an [xUpdate] method, any value for which 4945 ** sqlite3_value_nochange(X) is true will in all other respects appear 4946 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 4947 ** than within an [xUpdate] method call for an UPDATE statement, then 4948 ** the return value is arbitrary and meaningless. 4949 ** 4950 ** Please pay particular attention to the fact that the pointer returned 4951 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4952 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4953 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4954 ** or [sqlite3_value_text16()]. 4955 ** 4956 ** These routines must be called from the same thread as 4957 ** the SQL function that supplied the [sqlite3_value*] parameters. 4958 ** 4959 ** As long as the input parameter is correct, these routines can only 4960 ** fail if an out-of-memory error occurs during a format conversion. 4961 ** Only the following subset of interfaces are subject to out-of-memory 4962 ** errors: 4963 ** 4964 ** <ul> 4965 ** <li> sqlite3_value_blob() 4966 ** <li> sqlite3_value_text() 4967 ** <li> sqlite3_value_text16() 4968 ** <li> sqlite3_value_text16le() 4969 ** <li> sqlite3_value_text16be() 4970 ** <li> sqlite3_value_bytes() 4971 ** <li> sqlite3_value_bytes16() 4972 ** </ul> 4973 ** 4974 ** If an out-of-memory error occurs, then the return value from these 4975 ** routines is the same as if the column had contained an SQL NULL value. 4976 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 4977 ** by invoking the [sqlite3_errcode()] immediately after the suspect 4978 ** return value is obtained and before any 4979 ** other SQLite interface is called on the same [database connection]. 4980 */ 4981 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 4982 SQLITE_API double sqlite3_value_double(sqlite3_value*); 4983 SQLITE_API int sqlite3_value_int(sqlite3_value*); 4984 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4985 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 4986 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 4987 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 4988 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 4989 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 4990 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 4991 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 4992 SQLITE_API int sqlite3_value_type(sqlite3_value*); 4993 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 4994 SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 4995 4996 /* 4997 ** CAPI3REF: Finding The Subtype Of SQL Values 4998 ** METHOD: sqlite3_value 4999 ** 5000 ** The sqlite3_value_subtype(V) function returns the subtype for 5001 ** an [application-defined SQL function] argument V. The subtype 5002 ** information can be used to pass a limited amount of context from 5003 ** one SQL function to another. Use the [sqlite3_result_subtype()] 5004 ** routine to set the subtype for the return value of an SQL function. 5005 */ 5006 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 5007 5008 /* 5009 ** CAPI3REF: Copy And Free SQL Values 5010 ** METHOD: sqlite3_value 5011 ** 5012 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5013 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5014 ** is a [protected sqlite3_value] object even if the input is not. 5015 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5016 ** memory allocation fails. 5017 ** 5018 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5019 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5020 ** then sqlite3_value_free(V) is a harmless no-op. 5021 */ 5022 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5023 SQLITE_API void sqlite3_value_free(sqlite3_value*); 5024 5025 /* 5026 ** CAPI3REF: Obtain Aggregate Function Context 5027 ** METHOD: sqlite3_context 5028 ** 5029 ** Implementations of aggregate SQL functions use this 5030 ** routine to allocate memory for storing their state. 5031 ** 5032 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5033 ** for a particular aggregate function, SQLite 5034 ** allocates N of memory, zeroes out that memory, and returns a pointer 5035 ** to the new memory. ^On second and subsequent calls to 5036 ** sqlite3_aggregate_context() for the same aggregate function instance, 5037 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 5038 ** called once for each invocation of the xStep callback and then one 5039 ** last time when the xFinal callback is invoked. ^(When no rows match 5040 ** an aggregate query, the xStep() callback of the aggregate function 5041 ** implementation is never called and xFinal() is called exactly once. 5042 ** In those cases, sqlite3_aggregate_context() might be called for the 5043 ** first time from within xFinal().)^ 5044 ** 5045 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5046 ** when first called if N is less than or equal to zero or if a memory 5047 ** allocate error occurs. 5048 ** 5049 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5050 ** determined by the N parameter on first successful call. Changing the 5051 ** value of N in subsequent call to sqlite3_aggregate_context() within 5052 ** the same aggregate function instance will not resize the memory 5053 ** allocation.)^ Within the xFinal callback, it is customary to set 5054 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5055 ** pointless memory allocations occur. 5056 ** 5057 ** ^SQLite automatically frees the memory allocated by 5058 ** sqlite3_aggregate_context() when the aggregate query concludes. 5059 ** 5060 ** The first parameter must be a copy of the 5061 ** [sqlite3_context | SQL function context] that is the first parameter 5062 ** to the xStep or xFinal callback routine that implements the aggregate 5063 ** function. 5064 ** 5065 ** This routine must be called from the same thread in which 5066 ** the aggregate SQL function is running. 5067 */ 5068 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5069 5070 /* 5071 ** CAPI3REF: User Data For Functions 5072 ** METHOD: sqlite3_context 5073 ** 5074 ** ^The sqlite3_user_data() interface returns a copy of 5075 ** the pointer that was the pUserData parameter (the 5th parameter) 5076 ** of the [sqlite3_create_function()] 5077 ** and [sqlite3_create_function16()] routines that originally 5078 ** registered the application defined function. 5079 ** 5080 ** This routine must be called from the same thread in which 5081 ** the application-defined function is running. 5082 */ 5083 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 5084 5085 /* 5086 ** CAPI3REF: Database Connection For Functions 5087 ** METHOD: sqlite3_context 5088 ** 5089 ** ^The sqlite3_context_db_handle() interface returns a copy of 5090 ** the pointer to the [database connection] (the 1st parameter) 5091 ** of the [sqlite3_create_function()] 5092 ** and [sqlite3_create_function16()] routines that originally 5093 ** registered the application defined function. 5094 */ 5095 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5096 5097 /* 5098 ** CAPI3REF: Function Auxiliary Data 5099 ** METHOD: sqlite3_context 5100 ** 5101 ** These functions may be used by (non-aggregate) SQL functions to 5102 ** associate metadata with argument values. If the same value is passed to 5103 ** multiple invocations of the same SQL function during query execution, under 5104 ** some circumstances the associated metadata may be preserved. An example 5105 ** of where this might be useful is in a regular-expression matching 5106 ** function. The compiled version of the regular expression can be stored as 5107 ** metadata associated with the pattern string. 5108 ** Then as long as the pattern string remains the same, 5109 ** the compiled regular expression can be reused on multiple 5110 ** invocations of the same function. 5111 ** 5112 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5113 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5114 ** value to the application-defined function. ^N is zero for the left-most 5115 ** function argument. ^If there is no metadata 5116 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5117 ** returns a NULL pointer. 5118 ** 5119 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5120 ** argument of the application-defined function. ^Subsequent 5121 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5122 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5123 ** NULL if the metadata has been discarded. 5124 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5125 ** SQLite will invoke the destructor function X with parameter P exactly 5126 ** once, when the metadata is discarded. 5127 ** SQLite is free to discard the metadata at any time, including: <ul> 5128 ** <li> ^(when the corresponding function parameter changes)^, or 5129 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5130 ** SQL statement)^, or 5131 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5132 ** parameter)^, or 5133 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5134 ** allocation error occurs.)^ </ul> 5135 ** 5136 ** Note the last bullet in particular. The destructor X in 5137 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5138 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5139 ** should be called near the end of the function implementation and the 5140 ** function implementation should not make any use of P after 5141 ** sqlite3_set_auxdata() has been called. 5142 ** 5143 ** ^(In practice, metadata is preserved between function calls for 5144 ** function parameters that are compile-time constants, including literal 5145 ** values and [parameters] and expressions composed from the same.)^ 5146 ** 5147 ** The value of the N parameter to these interfaces should be non-negative. 5148 ** Future enhancements may make use of negative N values to define new 5149 ** kinds of function caching behavior. 5150 ** 5151 ** These routines must be called from the same thread in which 5152 ** the SQL function is running. 5153 */ 5154 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 5155 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5156 5157 5158 /* 5159 ** CAPI3REF: Constants Defining Special Destructor Behavior 5160 ** 5161 ** These are special values for the destructor that is passed in as the 5162 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5163 ** argument is SQLITE_STATIC, it means that the content pointer is constant 5164 ** and will never change. It does not need to be destroyed. ^The 5165 ** SQLITE_TRANSIENT value means that the content will likely change in 5166 ** the near future and that SQLite should make its own private copy of 5167 ** the content before returning. 5168 ** 5169 ** The typedef is necessary to work around problems in certain 5170 ** C++ compilers. 5171 */ 5172 typedef void (*sqlite3_destructor_type)(void*); 5173 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 5174 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5175 5176 /* 5177 ** CAPI3REF: Setting The Result Of An SQL Function 5178 ** METHOD: sqlite3_context 5179 ** 5180 ** These routines are used by the xFunc or xFinal callbacks that 5181 ** implement SQL functions and aggregates. See 5182 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 5183 ** for additional information. 5184 ** 5185 ** These functions work very much like the [parameter binding] family of 5186 ** functions used to bind values to host parameters in prepared statements. 5187 ** Refer to the [SQL parameter] documentation for additional information. 5188 ** 5189 ** ^The sqlite3_result_blob() interface sets the result from 5190 ** an application-defined function to be the BLOB whose content is pointed 5191 ** to by the second parameter and which is N bytes long where N is the 5192 ** third parameter. 5193 ** 5194 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5195 ** interfaces set the result of the application-defined function to be 5196 ** a BLOB containing all zero bytes and N bytes in size. 5197 ** 5198 ** ^The sqlite3_result_double() interface sets the result from 5199 ** an application-defined function to be a floating point value specified 5200 ** by its 2nd argument. 5201 ** 5202 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5203 ** cause the implemented SQL function to throw an exception. 5204 ** ^SQLite uses the string pointed to by the 5205 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5206 ** as the text of an error message. ^SQLite interprets the error 5207 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 5208 ** interprets the string from sqlite3_result_error16() as UTF-16 in native 5209 ** byte order. ^If the third parameter to sqlite3_result_error() 5210 ** or sqlite3_result_error16() is negative then SQLite takes as the error 5211 ** message all text up through the first zero character. 5212 ** ^If the third parameter to sqlite3_result_error() or 5213 ** sqlite3_result_error16() is non-negative then SQLite takes that many 5214 ** bytes (not characters) from the 2nd parameter as the error message. 5215 ** ^The sqlite3_result_error() and sqlite3_result_error16() 5216 ** routines make a private copy of the error message text before 5217 ** they return. Hence, the calling function can deallocate or 5218 ** modify the text after they return without harm. 5219 ** ^The sqlite3_result_error_code() function changes the error code 5220 ** returned by SQLite as a result of an error in a function. ^By default, 5221 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5222 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5223 ** 5224 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5225 ** error indicating that a string or BLOB is too long to represent. 5226 ** 5227 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5228 ** error indicating that a memory allocation failed. 5229 ** 5230 ** ^The sqlite3_result_int() interface sets the return value 5231 ** of the application-defined function to be the 32-bit signed integer 5232 ** value given in the 2nd argument. 5233 ** ^The sqlite3_result_int64() interface sets the return value 5234 ** of the application-defined function to be the 64-bit signed integer 5235 ** value given in the 2nd argument. 5236 ** 5237 ** ^The sqlite3_result_null() interface sets the return value 5238 ** of the application-defined function to be NULL. 5239 ** 5240 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 5241 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5242 ** set the return value of the application-defined function to be 5243 ** a text string which is represented as UTF-8, UTF-16 native byte order, 5244 ** UTF-16 little endian, or UTF-16 big endian, respectively. 5245 ** ^The sqlite3_result_text64() interface sets the return value of an 5246 ** application-defined function to be a text string in an encoding 5247 ** specified by the fifth (and last) parameter, which must be one 5248 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5249 ** ^SQLite takes the text result from the application from 5250 ** the 2nd parameter of the sqlite3_result_text* interfaces. 5251 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5252 ** is negative, then SQLite takes result text from the 2nd parameter 5253 ** through the first zero character. 5254 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5255 ** is non-negative, then as many bytes (not characters) of the text 5256 ** pointed to by the 2nd parameter are taken as the application-defined 5257 ** function result. If the 3rd parameter is non-negative, then it 5258 ** must be the byte offset into the string where the NUL terminator would 5259 ** appear if the string where NUL terminated. If any NUL characters occur 5260 ** in the string at a byte offset that is less than the value of the 3rd 5261 ** parameter, then the resulting string will contain embedded NULs and the 5262 ** result of expressions operating on strings with embedded NULs is undefined. 5263 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5264 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5265 ** function as the destructor on the text or BLOB result when it has 5266 ** finished using that result. 5267 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5268 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5269 ** assumes that the text or BLOB result is in constant space and does not 5270 ** copy the content of the parameter nor call a destructor on the content 5271 ** when it has finished using that result. 5272 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5273 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5274 ** then SQLite makes a copy of the result into space obtained 5275 ** from [sqlite3_malloc()] before it returns. 5276 ** 5277 ** ^The sqlite3_result_value() interface sets the result of 5278 ** the application-defined function to be a copy of the 5279 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5280 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5281 ** so that the [sqlite3_value] specified in the parameter may change or 5282 ** be deallocated after sqlite3_result_value() returns without harm. 5283 ** ^A [protected sqlite3_value] object may always be used where an 5284 ** [unprotected sqlite3_value] object is required, so either 5285 ** kind of [sqlite3_value] object can be used with this interface. 5286 ** 5287 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5288 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5289 ** also associates the host-language pointer P or type T with that 5290 ** NULL value such that the pointer can be retrieved within an 5291 ** [application-defined SQL function] using [sqlite3_value_pointer()]. 5292 ** ^If the D parameter is not NULL, then it is a pointer to a destructor 5293 ** for the P parameter. ^SQLite invokes D with P as its only argument 5294 ** when SQLite is finished with P. The T parameter should be a static 5295 ** string and preferably a string literal. The sqlite3_result_pointer() 5296 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5297 ** 5298 ** If these routines are called from within the different thread 5299 ** than the one containing the application-defined function that received 5300 ** the [sqlite3_context] pointer, the results are undefined. 5301 */ 5302 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5303 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 5304 sqlite3_uint64,void(*)(void*)); 5305 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 5306 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 5307 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 5308 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 5309 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 5310 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 5311 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 5312 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5313 SQLITE_API void sqlite3_result_null(sqlite3_context*); 5314 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5315 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5316 void(*)(void*), unsigned char encoding); 5317 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5318 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5319 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5320 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5321 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5322 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 5323 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5324 5325 5326 /* 5327 ** CAPI3REF: Setting The Subtype Of An SQL Function 5328 ** METHOD: sqlite3_context 5329 ** 5330 ** The sqlite3_result_subtype(C,T) function causes the subtype of 5331 ** the result from the [application-defined SQL function] with 5332 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 5333 ** of the subtype T are preserved in current versions of SQLite; 5334 ** higher order bits are discarded. 5335 ** The number of subtype bytes preserved by SQLite might increase 5336 ** in future releases of SQLite. 5337 */ 5338 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5339 5340 /* 5341 ** CAPI3REF: Define New Collating Sequences 5342 ** METHOD: sqlite3 5343 ** 5344 ** ^These functions add, remove, or modify a [collation] associated 5345 ** with the [database connection] specified as the first argument. 5346 ** 5347 ** ^The name of the collation is a UTF-8 string 5348 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5349 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5350 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5351 ** considered to be the same name. 5352 ** 5353 ** ^(The third argument (eTextRep) must be one of the constants: 5354 ** <ul> 5355 ** <li> [SQLITE_UTF8], 5356 ** <li> [SQLITE_UTF16LE], 5357 ** <li> [SQLITE_UTF16BE], 5358 ** <li> [SQLITE_UTF16], or 5359 ** <li> [SQLITE_UTF16_ALIGNED]. 5360 ** </ul>)^ 5361 ** ^The eTextRep argument determines the encoding of strings passed 5362 ** to the collating function callback, xCallback. 5363 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5364 ** force strings to be UTF16 with native byte order. 5365 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5366 ** on an even byte address. 5367 ** 5368 ** ^The fourth argument, pArg, is an application data pointer that is passed 5369 ** through as the first argument to the collating function callback. 5370 ** 5371 ** ^The fifth argument, xCallback, is a pointer to the collating function. 5372 ** ^Multiple collating functions can be registered using the same name but 5373 ** with different eTextRep parameters and SQLite will use whichever 5374 ** function requires the least amount of data transformation. 5375 ** ^If the xCallback argument is NULL then the collating function is 5376 ** deleted. ^When all collating functions having the same name are deleted, 5377 ** that collation is no longer usable. 5378 ** 5379 ** ^The collating function callback is invoked with a copy of the pArg 5380 ** application data pointer and with two strings in the encoding specified 5381 ** by the eTextRep argument. The collating function must return an 5382 ** integer that is negative, zero, or positive 5383 ** if the first string is less than, equal to, or greater than the second, 5384 ** respectively. A collating function must always return the same answer 5385 ** given the same inputs. If two or more collating functions are registered 5386 ** to the same collation name (using different eTextRep values) then all 5387 ** must give an equivalent answer when invoked with equivalent strings. 5388 ** The collating function must obey the following properties for all 5389 ** strings A, B, and C: 5390 ** 5391 ** <ol> 5392 ** <li> If A==B then B==A. 5393 ** <li> If A==B and B==C then A==C. 5394 ** <li> If A<B THEN B>A. 5395 ** <li> If A<B and B<C then A<C. 5396 ** </ol> 5397 ** 5398 ** If a collating function fails any of the above constraints and that 5399 ** collating function is registered and used, then the behavior of SQLite 5400 ** is undefined. 5401 ** 5402 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5403 ** with the addition that the xDestroy callback is invoked on pArg when 5404 ** the collating function is deleted. 5405 ** ^Collating functions are deleted when they are overridden by later 5406 ** calls to the collation creation functions or when the 5407 ** [database connection] is closed using [sqlite3_close()]. 5408 ** 5409 ** ^The xDestroy callback is <u>not</u> called if the 5410 ** sqlite3_create_collation_v2() function fails. Applications that invoke 5411 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5412 ** check the return code and dispose of the application data pointer 5413 ** themselves rather than expecting SQLite to deal with it for them. 5414 ** This is different from every other SQLite interface. The inconsistency 5415 ** is unfortunate but cannot be changed without breaking backwards 5416 ** compatibility. 5417 ** 5418 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5419 */ 5420 SQLITE_API int sqlite3_create_collation( 5421 sqlite3*, 5422 const char *zName, 5423 int eTextRep, 5424 void *pArg, 5425 int(*xCompare)(void*,int,const void*,int,const void*) 5426 ); 5427 SQLITE_API int sqlite3_create_collation_v2( 5428 sqlite3*, 5429 const char *zName, 5430 int eTextRep, 5431 void *pArg, 5432 int(*xCompare)(void*,int,const void*,int,const void*), 5433 void(*xDestroy)(void*) 5434 ); 5435 SQLITE_API int sqlite3_create_collation16( 5436 sqlite3*, 5437 const void *zName, 5438 int eTextRep, 5439 void *pArg, 5440 int(*xCompare)(void*,int,const void*,int,const void*) 5441 ); 5442 5443 /* 5444 ** CAPI3REF: Collation Needed Callbacks 5445 ** METHOD: sqlite3 5446 ** 5447 ** ^To avoid having to register all collation sequences before a database 5448 ** can be used, a single callback function may be registered with the 5449 ** [database connection] to be invoked whenever an undefined collation 5450 ** sequence is required. 5451 ** 5452 ** ^If the function is registered using the sqlite3_collation_needed() API, 5453 ** then it is passed the names of undefined collation sequences as strings 5454 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5455 ** the names are passed as UTF-16 in machine native byte order. 5456 ** ^A call to either function replaces the existing collation-needed callback. 5457 ** 5458 ** ^(When the callback is invoked, the first argument passed is a copy 5459 ** of the second argument to sqlite3_collation_needed() or 5460 ** sqlite3_collation_needed16(). The second argument is the database 5461 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5462 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5463 ** sequence function required. The fourth parameter is the name of the 5464 ** required collation sequence.)^ 5465 ** 5466 ** The callback function should register the desired collation using 5467 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5468 ** [sqlite3_create_collation_v2()]. 5469 */ 5470 SQLITE_API int sqlite3_collation_needed( 5471 sqlite3*, 5472 void*, 5473 void(*)(void*,sqlite3*,int eTextRep,const char*) 5474 ); 5475 SQLITE_API int sqlite3_collation_needed16( 5476 sqlite3*, 5477 void*, 5478 void(*)(void*,sqlite3*,int eTextRep,const void*) 5479 ); 5480 5481 #ifdef SQLITE_HAS_CODEC 5482 /* 5483 ** Specify the key for an encrypted database. This routine should be 5484 ** called right after sqlite3_open(). 5485 ** 5486 ** The code to implement this API is not available in the public release 5487 ** of SQLite. 5488 */ 5489 SQLITE_API int sqlite3_key( 5490 sqlite3 *db, /* Database to be rekeyed */ 5491 const void *pKey, int nKey /* The key */ 5492 ); 5493 SQLITE_API int sqlite3_key_v2( 5494 sqlite3 *db, /* Database to be rekeyed */ 5495 const char *zDbName, /* Name of the database */ 5496 const void *pKey, int nKey /* The key */ 5497 ); 5498 5499 /* 5500 ** Change the key on an open database. If the current database is not 5501 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5502 ** database is decrypted. 5503 ** 5504 ** The code to implement this API is not available in the public release 5505 ** of SQLite. 5506 */ 5507 SQLITE_API int sqlite3_rekey( 5508 sqlite3 *db, /* Database to be rekeyed */ 5509 const void *pKey, int nKey /* The new key */ 5510 ); 5511 SQLITE_API int sqlite3_rekey_v2( 5512 sqlite3 *db, /* Database to be rekeyed */ 5513 const char *zDbName, /* Name of the database */ 5514 const void *pKey, int nKey /* The new key */ 5515 ); 5516 5517 /* 5518 ** Specify the activation key for a SEE database. Unless 5519 ** activated, none of the SEE routines will work. 5520 */ 5521 SQLITE_API void sqlite3_activate_see( 5522 const char *zPassPhrase /* Activation phrase */ 5523 ); 5524 #endif 5525 5526 #ifdef SQLITE_ENABLE_CEROD 5527 /* 5528 ** Specify the activation key for a CEROD database. Unless 5529 ** activated, none of the CEROD routines will work. 5530 */ 5531 SQLITE_API void sqlite3_activate_cerod( 5532 const char *zPassPhrase /* Activation phrase */ 5533 ); 5534 #endif 5535 5536 /* 5537 ** CAPI3REF: Suspend Execution For A Short Time 5538 ** 5539 ** The sqlite3_sleep() function causes the current thread to suspend execution 5540 ** for at least a number of milliseconds specified in its parameter. 5541 ** 5542 ** If the operating system does not support sleep requests with 5543 ** millisecond time resolution, then the time will be rounded up to 5544 ** the nearest second. The number of milliseconds of sleep actually 5545 ** requested from the operating system is returned. 5546 ** 5547 ** ^SQLite implements this interface by calling the xSleep() 5548 ** method of the default [sqlite3_vfs] object. If the xSleep() method 5549 ** of the default VFS is not implemented correctly, or not implemented at 5550 ** all, then the behavior of sqlite3_sleep() may deviate from the description 5551 ** in the previous paragraphs. 5552 */ 5553 SQLITE_API int sqlite3_sleep(int); 5554 5555 /* 5556 ** CAPI3REF: Name Of The Folder Holding Temporary Files 5557 ** 5558 ** ^(If this global variable is made to point to a string which is 5559 ** the name of a folder (a.k.a. directory), then all temporary files 5560 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5561 ** will be placed in that directory.)^ ^If this variable 5562 ** is a NULL pointer, then SQLite performs a search for an appropriate 5563 ** temporary file directory. 5564 ** 5565 ** Applications are strongly discouraged from using this global variable. 5566 ** It is required to set a temporary folder on Windows Runtime (WinRT). 5567 ** But for all other platforms, it is highly recommended that applications 5568 ** neither read nor write this variable. This global variable is a relic 5569 ** that exists for backwards compatibility of legacy applications and should 5570 ** be avoided in new projects. 5571 ** 5572 ** It is not safe to read or modify this variable in more than one 5573 ** thread at a time. It is not safe to read or modify this variable 5574 ** if a [database connection] is being used at the same time in a separate 5575 ** thread. 5576 ** It is intended that this variable be set once 5577 ** as part of process initialization and before any SQLite interface 5578 ** routines have been called and that this variable remain unchanged 5579 ** thereafter. 5580 ** 5581 ** ^The [temp_store_directory pragma] may modify this variable and cause 5582 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5583 ** the [temp_store_directory pragma] always assumes that any string 5584 ** that this variable points to is held in memory obtained from 5585 ** [sqlite3_malloc] and the pragma may attempt to free that memory 5586 ** using [sqlite3_free]. 5587 ** Hence, if this variable is modified directly, either it should be 5588 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5589 ** or else the use of the [temp_store_directory pragma] should be avoided. 5590 ** Except when requested by the [temp_store_directory pragma], SQLite 5591 ** does not free the memory that sqlite3_temp_directory points to. If 5592 ** the application wants that memory to be freed, it must do 5593 ** so itself, taking care to only do so after all [database connection] 5594 ** objects have been destroyed. 5595 ** 5596 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5597 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5598 ** features that require the use of temporary files may fail. Here is an 5599 ** example of how to do this using C++ with the Windows Runtime: 5600 ** 5601 ** <blockquote><pre> 5602 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5603 ** TemporaryFolder->Path->Data(); 5604 ** char zPathBuf[MAX_PATH + 1]; 5605 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 5606 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5607 ** NULL, NULL); 5608 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5609 ** </pre></blockquote> 5610 */ 5611 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 5612 5613 /* 5614 ** CAPI3REF: Name Of The Folder Holding Database Files 5615 ** 5616 ** ^(If this global variable is made to point to a string which is 5617 ** the name of a folder (a.k.a. directory), then all database files 5618 ** specified with a relative pathname and created or accessed by 5619 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5620 ** to be relative to that directory.)^ ^If this variable is a NULL 5621 ** pointer, then SQLite assumes that all database files specified 5622 ** with a relative pathname are relative to the current directory 5623 ** for the process. Only the windows VFS makes use of this global 5624 ** variable; it is ignored by the unix VFS. 5625 ** 5626 ** Changing the value of this variable while a database connection is 5627 ** open can result in a corrupt database. 5628 ** 5629 ** It is not safe to read or modify this variable in more than one 5630 ** thread at a time. It is not safe to read or modify this variable 5631 ** if a [database connection] is being used at the same time in a separate 5632 ** thread. 5633 ** It is intended that this variable be set once 5634 ** as part of process initialization and before any SQLite interface 5635 ** routines have been called and that this variable remain unchanged 5636 ** thereafter. 5637 ** 5638 ** ^The [data_store_directory pragma] may modify this variable and cause 5639 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5640 ** the [data_store_directory pragma] always assumes that any string 5641 ** that this variable points to is held in memory obtained from 5642 ** [sqlite3_malloc] and the pragma may attempt to free that memory 5643 ** using [sqlite3_free]. 5644 ** Hence, if this variable is modified directly, either it should be 5645 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5646 ** or else the use of the [data_store_directory pragma] should be avoided. 5647 */ 5648 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 5649 5650 /* 5651 ** CAPI3REF: Win32 Specific Interface 5652 ** 5653 ** These interfaces are available only on Windows. The 5654 ** [sqlite3_win32_set_directory] interface is used to set the value associated 5655 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 5656 ** zValue, depending on the value of the type parameter. The zValue parameter 5657 ** should be NULL to cause the previous value to be freed via [sqlite3_free]; 5658 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 5659 ** prior to being used. The [sqlite3_win32_set_directory] interface returns 5660 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 5661 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 5662 ** [sqlite3_data_directory] variable is intended to act as a replacement for 5663 ** the current directory on the sub-platforms of Win32 where that concept is 5664 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 5665 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 5666 ** sqlite3_win32_set_directory interface except the string parameter must be 5667 ** UTF-8 or UTF-16, respectively. 5668 */ 5669 SQLITE_API int sqlite3_win32_set_directory( 5670 unsigned long type, /* Identifier for directory being set or reset */ 5671 void *zValue /* New value for directory being set or reset */ 5672 ); 5673 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 5674 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 5675 5676 /* 5677 ** CAPI3REF: Win32 Directory Types 5678 ** 5679 ** These macros are only available on Windows. They define the allowed values 5680 ** for the type argument to the [sqlite3_win32_set_directory] interface. 5681 */ 5682 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 5683 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 5684 5685 /* 5686 ** CAPI3REF: Test For Auto-Commit Mode 5687 ** KEYWORDS: {autocommit mode} 5688 ** METHOD: sqlite3 5689 ** 5690 ** ^The sqlite3_get_autocommit() interface returns non-zero or 5691 ** zero if the given database connection is or is not in autocommit mode, 5692 ** respectively. ^Autocommit mode is on by default. 5693 ** ^Autocommit mode is disabled by a [BEGIN] statement. 5694 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5695 ** 5696 ** If certain kinds of errors occur on a statement within a multi-statement 5697 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5698 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5699 ** transaction might be rolled back automatically. The only way to 5700 ** find out whether SQLite automatically rolled back the transaction after 5701 ** an error is to use this function. 5702 ** 5703 ** If another thread changes the autocommit status of the database 5704 ** connection while this routine is running, then the return value 5705 ** is undefined. 5706 */ 5707 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 5708 5709 /* 5710 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 5711 ** METHOD: sqlite3_stmt 5712 ** 5713 ** ^The sqlite3_db_handle interface returns the [database connection] handle 5714 ** to which a [prepared statement] belongs. ^The [database connection] 5715 ** returned by sqlite3_db_handle is the same [database connection] 5716 ** that was the first argument 5717 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5718 ** create the statement in the first place. 5719 */ 5720 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 5721 5722 /* 5723 ** CAPI3REF: Return The Filename For A Database Connection 5724 ** METHOD: sqlite3 5725 ** 5726 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5727 ** associated with database N of connection D. ^The main database file 5728 ** has the name "main". If there is no attached database N on the database 5729 ** connection D, or if database N is a temporary or in-memory database, then 5730 ** a NULL pointer is returned. 5731 ** 5732 ** ^The filename returned by this function is the output of the 5733 ** xFullPathname method of the [VFS]. ^In other words, the filename 5734 ** will be an absolute pathname, even if the filename used 5735 ** to open the database originally was a URI or relative pathname. 5736 */ 5737 SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5738 5739 /* 5740 ** CAPI3REF: Determine if a database is read-only 5741 ** METHOD: sqlite3 5742 ** 5743 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5744 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5745 ** the name of a database on connection D. 5746 */ 5747 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5748 5749 /* 5750 ** CAPI3REF: Find the next prepared statement 5751 ** METHOD: sqlite3 5752 ** 5753 ** ^This interface returns a pointer to the next [prepared statement] after 5754 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5755 ** then this interface returns a pointer to the first prepared statement 5756 ** associated with the database connection pDb. ^If no prepared statement 5757 ** satisfies the conditions of this routine, it returns NULL. 5758 ** 5759 ** The [database connection] pointer D in a call to 5760 ** [sqlite3_next_stmt(D,S)] must refer to an open database 5761 ** connection and in particular must not be a NULL pointer. 5762 */ 5763 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5764 5765 /* 5766 ** CAPI3REF: Commit And Rollback Notification Callbacks 5767 ** METHOD: sqlite3 5768 ** 5769 ** ^The sqlite3_commit_hook() interface registers a callback 5770 ** function to be invoked whenever a transaction is [COMMIT | committed]. 5771 ** ^Any callback set by a previous call to sqlite3_commit_hook() 5772 ** for the same database connection is overridden. 5773 ** ^The sqlite3_rollback_hook() interface registers a callback 5774 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5775 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 5776 ** for the same database connection is overridden. 5777 ** ^The pArg argument is passed through to the callback. 5778 ** ^If the callback on a commit hook function returns non-zero, 5779 ** then the commit is converted into a rollback. 5780 ** 5781 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5782 ** return the P argument from the previous call of the same function 5783 ** on the same [database connection] D, or NULL for 5784 ** the first call for each function on D. 5785 ** 5786 ** The commit and rollback hook callbacks are not reentrant. 5787 ** The callback implementation must not do anything that will modify 5788 ** the database connection that invoked the callback. Any actions 5789 ** to modify the database connection must be deferred until after the 5790 ** completion of the [sqlite3_step()] call that triggered the commit 5791 ** or rollback hook in the first place. 5792 ** Note that running any other SQL statements, including SELECT statements, 5793 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5794 ** the database connections for the meaning of "modify" in this paragraph. 5795 ** 5796 ** ^Registering a NULL function disables the callback. 5797 ** 5798 ** ^When the commit hook callback routine returns zero, the [COMMIT] 5799 ** operation is allowed to continue normally. ^If the commit hook 5800 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5801 ** ^The rollback hook is invoked on a rollback that results from a commit 5802 ** hook returning non-zero, just as it would be with any other rollback. 5803 ** 5804 ** ^For the purposes of this API, a transaction is said to have been 5805 ** rolled back if an explicit "ROLLBACK" statement is executed, or 5806 ** an error or constraint causes an implicit rollback to occur. 5807 ** ^The rollback callback is not invoked if a transaction is 5808 ** automatically rolled back because the database connection is closed. 5809 ** 5810 ** See also the [sqlite3_update_hook()] interface. 5811 */ 5812 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5813 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5814 5815 /* 5816 ** CAPI3REF: Data Change Notification Callbacks 5817 ** METHOD: sqlite3 5818 ** 5819 ** ^The sqlite3_update_hook() interface registers a callback function 5820 ** with the [database connection] identified by the first argument 5821 ** to be invoked whenever a row is updated, inserted or deleted in 5822 ** a [rowid table]. 5823 ** ^Any callback set by a previous call to this function 5824 ** for the same database connection is overridden. 5825 ** 5826 ** ^The second argument is a pointer to the function to invoke when a 5827 ** row is updated, inserted or deleted in a rowid table. 5828 ** ^The first argument to the callback is a copy of the third argument 5829 ** to sqlite3_update_hook(). 5830 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5831 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 5832 ** to be invoked. 5833 ** ^The third and fourth arguments to the callback contain pointers to the 5834 ** database and table name containing the affected row. 5835 ** ^The final callback parameter is the [rowid] of the row. 5836 ** ^In the case of an update, this is the [rowid] after the update takes place. 5837 ** 5838 ** ^(The update hook is not invoked when internal system tables are 5839 ** modified (i.e. sqlite_master and sqlite_sequence).)^ 5840 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5841 ** 5842 ** ^In the current implementation, the update hook 5843 ** is not invoked when conflicting rows are deleted because of an 5844 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5845 ** invoked when rows are deleted using the [truncate optimization]. 5846 ** The exceptions defined in this paragraph might change in a future 5847 ** release of SQLite. 5848 ** 5849 ** The update hook implementation must not do anything that will modify 5850 ** the database connection that invoked the update hook. Any actions 5851 ** to modify the database connection must be deferred until after the 5852 ** completion of the [sqlite3_step()] call that triggered the update hook. 5853 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5854 ** database connections for the meaning of "modify" in this paragraph. 5855 ** 5856 ** ^The sqlite3_update_hook(D,C,P) function 5857 ** returns the P argument from the previous call 5858 ** on the same [database connection] D, or NULL for 5859 ** the first call on D. 5860 ** 5861 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 5862 ** and [sqlite3_preupdate_hook()] interfaces. 5863 */ 5864 SQLITE_API void *sqlite3_update_hook( 5865 sqlite3*, 5866 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5867 void* 5868 ); 5869 5870 /* 5871 ** CAPI3REF: Enable Or Disable Shared Pager Cache 5872 ** 5873 ** ^(This routine enables or disables the sharing of the database cache 5874 ** and schema data structures between [database connection | connections] 5875 ** to the same database. Sharing is enabled if the argument is true 5876 ** and disabled if the argument is false.)^ 5877 ** 5878 ** ^Cache sharing is enabled and disabled for an entire process. 5879 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 5880 ** In prior versions of SQLite, 5881 ** sharing was enabled or disabled for each thread separately. 5882 ** 5883 ** ^(The cache sharing mode set by this interface effects all subsequent 5884 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5885 ** Existing database connections continue use the sharing mode 5886 ** that was in effect at the time they were opened.)^ 5887 ** 5888 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5889 ** successfully. An [error code] is returned otherwise.)^ 5890 ** 5891 ** ^Shared cache is disabled by default. But this might change in 5892 ** future releases of SQLite. Applications that care about shared 5893 ** cache setting should set it explicitly. 5894 ** 5895 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5896 ** and will always return SQLITE_MISUSE. On those systems, 5897 ** shared cache mode should be enabled per-database connection via 5898 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5899 ** 5900 ** This interface is threadsafe on processors where writing a 5901 ** 32-bit integer is atomic. 5902 ** 5903 ** See Also: [SQLite Shared-Cache Mode] 5904 */ 5905 SQLITE_API int sqlite3_enable_shared_cache(int); 5906 5907 /* 5908 ** CAPI3REF: Attempt To Free Heap Memory 5909 ** 5910 ** ^The sqlite3_release_memory() interface attempts to free N bytes 5911 ** of heap memory by deallocating non-essential memory allocations 5912 ** held by the database library. Memory used to cache database 5913 ** pages to improve performance is an example of non-essential memory. 5914 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 5915 ** which might be more or less than the amount requested. 5916 ** ^The sqlite3_release_memory() routine is a no-op returning zero 5917 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5918 ** 5919 ** See also: [sqlite3_db_release_memory()] 5920 */ 5921 SQLITE_API int sqlite3_release_memory(int); 5922 5923 /* 5924 ** CAPI3REF: Free Memory Used By A Database Connection 5925 ** METHOD: sqlite3 5926 ** 5927 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5928 ** memory as possible from database connection D. Unlike the 5929 ** [sqlite3_release_memory()] interface, this interface is in effect even 5930 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5931 ** omitted. 5932 ** 5933 ** See also: [sqlite3_release_memory()] 5934 */ 5935 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 5936 5937 /* 5938 ** CAPI3REF: Impose A Limit On Heap Size 5939 ** 5940 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5941 ** soft limit on the amount of heap memory that may be allocated by SQLite. 5942 ** ^SQLite strives to keep heap memory utilization below the soft heap 5943 ** limit by reducing the number of pages held in the page cache 5944 ** as heap memory usages approaches the limit. 5945 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 5946 ** below the limit, it will exceed the limit rather than generate 5947 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5948 ** is advisory only. 5949 ** 5950 ** ^The return value from sqlite3_soft_heap_limit64() is the size of 5951 ** the soft heap limit prior to the call, or negative in the case of an 5952 ** error. ^If the argument N is negative 5953 ** then no change is made to the soft heap limit. Hence, the current 5954 ** size of the soft heap limit can be determined by invoking 5955 ** sqlite3_soft_heap_limit64() with a negative argument. 5956 ** 5957 ** ^If the argument N is zero then the soft heap limit is disabled. 5958 ** 5959 ** ^(The soft heap limit is not enforced in the current implementation 5960 ** if one or more of following conditions are true: 5961 ** 5962 ** <ul> 5963 ** <li> The soft heap limit is set to zero. 5964 ** <li> Memory accounting is disabled using a combination of the 5965 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5966 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5967 ** <li> An alternative page cache implementation is specified using 5968 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5969 ** <li> The page cache allocates from its own memory pool supplied 5970 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5971 ** from the heap. 5972 ** </ul>)^ 5973 ** 5974 ** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]), 5975 ** the soft heap limit is enforced 5976 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5977 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5978 ** the soft heap limit is enforced on every memory allocation. Without 5979 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5980 ** when memory is allocated by the page cache. Testing suggests that because 5981 ** the page cache is the predominate memory user in SQLite, most 5982 ** applications will achieve adequate soft heap limit enforcement without 5983 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5984 ** 5985 ** The circumstances under which SQLite will enforce the soft heap limit may 5986 ** changes in future releases of SQLite. 5987 */ 5988 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 5989 5990 /* 5991 ** CAPI3REF: Deprecated Soft Heap Limit Interface 5992 ** DEPRECATED 5993 ** 5994 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5995 ** interface. This routine is provided for historical compatibility 5996 ** only. All new applications should use the 5997 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 5998 */ 5999 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6000 6001 6002 /* 6003 ** CAPI3REF: Extract Metadata About A Column Of A Table 6004 ** METHOD: sqlite3 6005 ** 6006 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6007 ** information about column C of table T in database D 6008 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6009 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 6010 ** the final five arguments with appropriate values if the specified 6011 ** column exists. ^The sqlite3_table_column_metadata() interface returns 6012 ** SQLITE_ERROR and if the specified column does not exist. 6013 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6014 ** NULL pointer, then this routine simply checks for the existence of the 6015 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6016 ** does not. If the table name parameter T in a call to 6017 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6018 ** undefined behavior. 6019 ** 6020 ** ^The column is identified by the second, third and fourth parameters to 6021 ** this function. ^(The second parameter is either the name of the database 6022 ** (i.e. "main", "temp", or an attached database) containing the specified 6023 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6024 ** for the table using the same algorithm used by the database engine to 6025 ** resolve unqualified table references. 6026 ** 6027 ** ^The third and fourth parameters to this function are the table and column 6028 ** name of the desired column, respectively. 6029 ** 6030 ** ^Metadata is returned by writing to the memory locations passed as the 5th 6031 ** and subsequent parameters to this function. ^Any of these arguments may be 6032 ** NULL, in which case the corresponding element of metadata is omitted. 6033 ** 6034 ** ^(<blockquote> 6035 ** <table border="1"> 6036 ** <tr><th> Parameter <th> Output<br>Type <th> Description 6037 ** 6038 ** <tr><td> 5th <td> const char* <td> Data type 6039 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6040 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6041 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6042 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6043 ** </table> 6044 ** </blockquote>)^ 6045 ** 6046 ** ^The memory pointed to by the character pointers returned for the 6047 ** declaration type and collation sequence is valid until the next 6048 ** call to any SQLite API function. 6049 ** 6050 ** ^If the specified table is actually a view, an [error code] is returned. 6051 ** 6052 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6053 ** is not a [WITHOUT ROWID] table and an 6054 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6055 ** parameters are set for the explicitly declared column. ^(If there is no 6056 ** [INTEGER PRIMARY KEY] column, then the outputs 6057 ** for the [rowid] are set as follows: 6058 ** 6059 ** <pre> 6060 ** data type: "INTEGER" 6061 ** collation sequence: "BINARY" 6062 ** not null: 0 6063 ** primary key: 1 6064 ** auto increment: 0 6065 ** </pre>)^ 6066 ** 6067 ** ^This function causes all database schemas to be read from disk and 6068 ** parsed, if that has not already been done, and returns an error if 6069 ** any errors are encountered while loading the schema. 6070 */ 6071 SQLITE_API int sqlite3_table_column_metadata( 6072 sqlite3 *db, /* Connection handle */ 6073 const char *zDbName, /* Database name or NULL */ 6074 const char *zTableName, /* Table name */ 6075 const char *zColumnName, /* Column name */ 6076 char const **pzDataType, /* OUTPUT: Declared data type */ 6077 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6078 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6079 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6080 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6081 ); 6082 6083 /* 6084 ** CAPI3REF: Load An Extension 6085 ** METHOD: sqlite3 6086 ** 6087 ** ^This interface loads an SQLite extension library from the named file. 6088 ** 6089 ** ^The sqlite3_load_extension() interface attempts to load an 6090 ** [SQLite extension] library contained in the file zFile. If 6091 ** the file cannot be loaded directly, attempts are made to load 6092 ** with various operating-system specific extensions added. 6093 ** So for example, if "samplelib" cannot be loaded, then names like 6094 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6095 ** be tried also. 6096 ** 6097 ** ^The entry point is zProc. 6098 ** ^(zProc may be 0, in which case SQLite will try to come up with an 6099 ** entry point name on its own. It first tries "sqlite3_extension_init". 6100 ** If that does not work, it constructs a name "sqlite3_X_init" where the 6101 ** X is consists of the lower-case equivalent of all ASCII alphabetic 6102 ** characters in the filename from the last "/" to the first following 6103 ** "." and omitting any initial "lib".)^ 6104 ** ^The sqlite3_load_extension() interface returns 6105 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6106 ** ^If an error occurs and pzErrMsg is not 0, then the 6107 ** [sqlite3_load_extension()] interface shall attempt to 6108 ** fill *pzErrMsg with error message text stored in memory 6109 ** obtained from [sqlite3_malloc()]. The calling function 6110 ** should free this memory by calling [sqlite3_free()]. 6111 ** 6112 ** ^Extension loading must be enabled using 6113 ** [sqlite3_enable_load_extension()] or 6114 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6115 ** prior to calling this API, 6116 ** otherwise an error will be returned. 6117 ** 6118 ** <b>Security warning:</b> It is recommended that the 6119 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6120 ** interface. The use of the [sqlite3_enable_load_extension()] interface 6121 ** should be avoided. This will keep the SQL function [load_extension()] 6122 ** disabled and prevent SQL injections from giving attackers 6123 ** access to extension loading capabilities. 6124 ** 6125 ** See also the [load_extension() SQL function]. 6126 */ 6127 SQLITE_API int sqlite3_load_extension( 6128 sqlite3 *db, /* Load the extension into this database connection */ 6129 const char *zFile, /* Name of the shared library containing extension */ 6130 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6131 char **pzErrMsg /* Put error message here if not 0 */ 6132 ); 6133 6134 /* 6135 ** CAPI3REF: Enable Or Disable Extension Loading 6136 ** METHOD: sqlite3 6137 ** 6138 ** ^So as not to open security holes in older applications that are 6139 ** unprepared to deal with [extension loading], and as a means of disabling 6140 ** [extension loading] while evaluating user-entered SQL, the following API 6141 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6142 ** 6143 ** ^Extension loading is off by default. 6144 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6145 ** to turn extension loading on and call it with onoff==0 to turn 6146 ** it back off again. 6147 ** 6148 ** ^This interface enables or disables both the C-API 6149 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6150 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6151 ** to enable or disable only the C-API.)^ 6152 ** 6153 ** <b>Security warning:</b> It is recommended that extension loading 6154 ** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6155 ** rather than this interface, so the [load_extension()] SQL function 6156 ** remains disabled. This will prevent SQL injections from giving attackers 6157 ** access to extension loading capabilities. 6158 */ 6159 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6160 6161 /* 6162 ** CAPI3REF: Automatically Load Statically Linked Extensions 6163 ** 6164 ** ^This interface causes the xEntryPoint() function to be invoked for 6165 ** each new [database connection] that is created. The idea here is that 6166 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6167 ** that is to be automatically loaded into all new database connections. 6168 ** 6169 ** ^(Even though the function prototype shows that xEntryPoint() takes 6170 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 6171 ** arguments and expects an integer result as if the signature of the 6172 ** entry point where as follows: 6173 ** 6174 ** <blockquote><pre> 6175 ** int xEntryPoint( 6176 ** sqlite3 *db, 6177 ** const char **pzErrMsg, 6178 ** const struct sqlite3_api_routines *pThunk 6179 ** ); 6180 ** </pre></blockquote>)^ 6181 ** 6182 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6183 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6184 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6185 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6186 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6187 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6188 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6189 ** 6190 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6191 ** on the list of automatic extensions is a harmless no-op. ^No entry point 6192 ** will be called more than once for each database connection that is opened. 6193 ** 6194 ** See also: [sqlite3_reset_auto_extension()] 6195 ** and [sqlite3_cancel_auto_extension()] 6196 */ 6197 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6198 6199 /* 6200 ** CAPI3REF: Cancel Automatic Extension Loading 6201 ** 6202 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6203 ** initialization routine X that was registered using a prior call to 6204 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6205 ** routine returns 1 if initialization routine X was successfully 6206 ** unregistered and it returns 0 if X was not on the list of initialization 6207 ** routines. 6208 */ 6209 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6210 6211 /* 6212 ** CAPI3REF: Reset Automatic Extension Loading 6213 ** 6214 ** ^This interface disables all automatic extensions previously 6215 ** registered using [sqlite3_auto_extension()]. 6216 */ 6217 SQLITE_API void sqlite3_reset_auto_extension(void); 6218 6219 /* 6220 ** The interface to the virtual-table mechanism is currently considered 6221 ** to be experimental. The interface might change in incompatible ways. 6222 ** If this is a problem for you, do not use the interface at this time. 6223 ** 6224 ** When the virtual-table mechanism stabilizes, we will declare the 6225 ** interface fixed, support it indefinitely, and remove this comment. 6226 */ 6227 6228 /* 6229 ** Structures used by the virtual table interface 6230 */ 6231 typedef struct sqlite3_vtab sqlite3_vtab; 6232 typedef struct sqlite3_index_info sqlite3_index_info; 6233 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6234 typedef struct sqlite3_module sqlite3_module; 6235 6236 /* 6237 ** CAPI3REF: Virtual Table Object 6238 ** KEYWORDS: sqlite3_module {virtual table module} 6239 ** 6240 ** This structure, sometimes called a "virtual table module", 6241 ** defines the implementation of a [virtual tables]. 6242 ** This structure consists mostly of methods for the module. 6243 ** 6244 ** ^A virtual table module is created by filling in a persistent 6245 ** instance of this structure and passing a pointer to that instance 6246 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6247 ** ^The registration remains valid until it is replaced by a different 6248 ** module or until the [database connection] closes. The content 6249 ** of this structure must not change while it is registered with 6250 ** any database connection. 6251 */ 6252 struct sqlite3_module { 6253 int iVersion; 6254 int (*xCreate)(sqlite3*, void *pAux, 6255 int argc, const char *const*argv, 6256 sqlite3_vtab **ppVTab, char**); 6257 int (*xConnect)(sqlite3*, void *pAux, 6258 int argc, const char *const*argv, 6259 sqlite3_vtab **ppVTab, char**); 6260 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6261 int (*xDisconnect)(sqlite3_vtab *pVTab); 6262 int (*xDestroy)(sqlite3_vtab *pVTab); 6263 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6264 int (*xClose)(sqlite3_vtab_cursor*); 6265 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6266 int argc, sqlite3_value **argv); 6267 int (*xNext)(sqlite3_vtab_cursor*); 6268 int (*xEof)(sqlite3_vtab_cursor*); 6269 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6270 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6271 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6272 int (*xBegin)(sqlite3_vtab *pVTab); 6273 int (*xSync)(sqlite3_vtab *pVTab); 6274 int (*xCommit)(sqlite3_vtab *pVTab); 6275 int (*xRollback)(sqlite3_vtab *pVTab); 6276 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6277 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6278 void **ppArg); 6279 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6280 /* The methods above are in version 1 of the sqlite_module object. Those 6281 ** below are for version 2 and greater. */ 6282 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6283 int (*xRelease)(sqlite3_vtab *pVTab, int); 6284 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6285 }; 6286 6287 /* 6288 ** CAPI3REF: Virtual Table Indexing Information 6289 ** KEYWORDS: sqlite3_index_info 6290 ** 6291 ** The sqlite3_index_info structure and its substructures is used as part 6292 ** of the [virtual table] interface to 6293 ** pass information into and receive the reply from the [xBestIndex] 6294 ** method of a [virtual table module]. The fields under **Inputs** are the 6295 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 6296 ** results into the **Outputs** fields. 6297 ** 6298 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 6299 ** 6300 ** <blockquote>column OP expr</blockquote> 6301 ** 6302 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6303 ** stored in aConstraint[].op using one of the 6304 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6305 ** ^(The index of the column is stored in 6306 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6307 ** expr on the right-hand side can be evaluated (and thus the constraint 6308 ** is usable) and false if it cannot.)^ 6309 ** 6310 ** ^The optimizer automatically inverts terms of the form "expr OP column" 6311 ** and makes other simplifications to the WHERE clause in an attempt to 6312 ** get as many WHERE clause terms into the form shown above as possible. 6313 ** ^The aConstraint[] array only reports WHERE clause terms that are 6314 ** relevant to the particular virtual table being queried. 6315 ** 6316 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6317 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 6318 ** 6319 ** The colUsed field indicates which columns of the virtual table may be 6320 ** required by the current scan. Virtual table columns are numbered from 6321 ** zero in the order in which they appear within the CREATE TABLE statement 6322 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6323 ** the corresponding bit is set within the colUsed mask if the column may be 6324 ** required by SQLite. If the table has at least 64 columns and any column 6325 ** to the right of the first 63 is required, then bit 63 of colUsed is also 6326 ** set. In other words, column iCol may be required if the expression 6327 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6328 ** non-zero. 6329 ** 6330 ** The [xBestIndex] method must fill aConstraintUsage[] with information 6331 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 6332 ** the right-hand side of the corresponding aConstraint[] is evaluated 6333 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6334 ** is true, then the constraint is assumed to be fully handled by the 6335 ** virtual table and is not checked again by SQLite.)^ 6336 ** 6337 ** ^The idxNum and idxPtr values are recorded and passed into the 6338 ** [xFilter] method. 6339 ** ^[sqlite3_free()] is used to free idxPtr if and only if 6340 ** needToFreeIdxPtr is true. 6341 ** 6342 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6343 ** the correct order to satisfy the ORDER BY clause so that no separate 6344 ** sorting step is required. 6345 ** 6346 ** ^The estimatedCost value is an estimate of the cost of a particular 6347 ** strategy. A cost of N indicates that the cost of the strategy is similar 6348 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 6349 ** indicates that the expense of the operation is similar to that of a 6350 ** binary search on a unique indexed field of an SQLite table with N rows. 6351 ** 6352 ** ^The estimatedRows value is an estimate of the number of rows that 6353 ** will be returned by the strategy. 6354 ** 6355 ** The xBestIndex method may optionally populate the idxFlags field with a 6356 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6357 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6358 ** assumes that the strategy may visit at most one row. 6359 ** 6360 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6361 ** SQLite also assumes that if a call to the xUpdate() method is made as 6362 ** part of the same statement to delete or update a virtual table row and the 6363 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6364 ** any database changes. In other words, if the xUpdate() returns 6365 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6366 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6367 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6368 ** the xUpdate method are automatically rolled back by SQLite. 6369 ** 6370 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6371 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6372 ** If a virtual table extension is 6373 ** used with an SQLite version earlier than 3.8.2, the results of attempting 6374 ** to read or write the estimatedRows field are undefined (but are likely 6375 ** to included crashing the application). The estimatedRows field should 6376 ** therefore only be used if [sqlite3_libversion_number()] returns a 6377 ** value greater than or equal to 3008002. Similarly, the idxFlags field 6378 ** was added for [version 3.9.0] ([dateof:3.9.0]). 6379 ** It may therefore only be used if 6380 ** sqlite3_libversion_number() returns a value greater than or equal to 6381 ** 3009000. 6382 */ 6383 struct sqlite3_index_info { 6384 /* Inputs */ 6385 int nConstraint; /* Number of entries in aConstraint */ 6386 struct sqlite3_index_constraint { 6387 int iColumn; /* Column constrained. -1 for ROWID */ 6388 unsigned char op; /* Constraint operator */ 6389 unsigned char usable; /* True if this constraint is usable */ 6390 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6391 } *aConstraint; /* Table of WHERE clause constraints */ 6392 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6393 struct sqlite3_index_orderby { 6394 int iColumn; /* Column number */ 6395 unsigned char desc; /* True for DESC. False for ASC. */ 6396 } *aOrderBy; /* The ORDER BY clause */ 6397 /* Outputs */ 6398 struct sqlite3_index_constraint_usage { 6399 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6400 unsigned char omit; /* Do not code a test for this constraint */ 6401 } *aConstraintUsage; 6402 int idxNum; /* Number used to identify the index */ 6403 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6404 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6405 int orderByConsumed; /* True if output is already ordered */ 6406 double estimatedCost; /* Estimated cost of using this index */ 6407 /* Fields below are only available in SQLite 3.8.2 and later */ 6408 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6409 /* Fields below are only available in SQLite 3.9.0 and later */ 6410 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6411 /* Fields below are only available in SQLite 3.10.0 and later */ 6412 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6413 }; 6414 6415 /* 6416 ** CAPI3REF: Virtual Table Scan Flags 6417 ** 6418 ** Virtual table implementations are allowed to set the 6419 ** [sqlite3_index_info].idxFlags field to some combination of 6420 ** these bits. 6421 */ 6422 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6423 6424 /* 6425 ** CAPI3REF: Virtual Table Constraint Operator Codes 6426 ** 6427 ** These macros defined the allowed values for the 6428 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 6429 ** an operator that is part of a constraint term in the wHERE clause of 6430 ** a query that uses a [virtual table]. 6431 */ 6432 #define SQLITE_INDEX_CONSTRAINT_EQ 2 6433 #define SQLITE_INDEX_CONSTRAINT_GT 4 6434 #define SQLITE_INDEX_CONSTRAINT_LE 8 6435 #define SQLITE_INDEX_CONSTRAINT_LT 16 6436 #define SQLITE_INDEX_CONSTRAINT_GE 32 6437 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 6438 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 6439 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 6440 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6441 #define SQLITE_INDEX_CONSTRAINT_NE 68 6442 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69 6443 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 6444 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71 6445 #define SQLITE_INDEX_CONSTRAINT_IS 72 6446 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 6447 6448 /* 6449 ** CAPI3REF: Register A Virtual Table Implementation 6450 ** METHOD: sqlite3 6451 ** 6452 ** ^These routines are used to register a new [virtual table module] name. 6453 ** ^Module names must be registered before 6454 ** creating a new [virtual table] using the module and before using a 6455 ** preexisting [virtual table] for the module. 6456 ** 6457 ** ^The module name is registered on the [database connection] specified 6458 ** by the first parameter. ^The name of the module is given by the 6459 ** second parameter. ^The third parameter is a pointer to 6460 ** the implementation of the [virtual table module]. ^The fourth 6461 ** parameter is an arbitrary client data pointer that is passed through 6462 ** into the [xCreate] and [xConnect] methods of the virtual table module 6463 ** when a new virtual table is be being created or reinitialized. 6464 ** 6465 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6466 ** is a pointer to a destructor for the pClientData. ^SQLite will 6467 ** invoke the destructor function (if it is not NULL) when SQLite 6468 ** no longer needs the pClientData pointer. ^The destructor will also 6469 ** be invoked if the call to sqlite3_create_module_v2() fails. 6470 ** ^The sqlite3_create_module() 6471 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 6472 ** destructor. 6473 */ 6474 SQLITE_API int sqlite3_create_module( 6475 sqlite3 *db, /* SQLite connection to register module with */ 6476 const char *zName, /* Name of the module */ 6477 const sqlite3_module *p, /* Methods for the module */ 6478 void *pClientData /* Client data for xCreate/xConnect */ 6479 ); 6480 SQLITE_API int sqlite3_create_module_v2( 6481 sqlite3 *db, /* SQLite connection to register module with */ 6482 const char *zName, /* Name of the module */ 6483 const sqlite3_module *p, /* Methods for the module */ 6484 void *pClientData, /* Client data for xCreate/xConnect */ 6485 void(*xDestroy)(void*) /* Module destructor function */ 6486 ); 6487 6488 /* 6489 ** CAPI3REF: Virtual Table Instance Object 6490 ** KEYWORDS: sqlite3_vtab 6491 ** 6492 ** Every [virtual table module] implementation uses a subclass 6493 ** of this object to describe a particular instance 6494 ** of the [virtual table]. Each subclass will 6495 ** be tailored to the specific needs of the module implementation. 6496 ** The purpose of this superclass is to define certain fields that are 6497 ** common to all module implementations. 6498 ** 6499 ** ^Virtual tables methods can set an error message by assigning a 6500 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6501 ** take care that any prior string is freed by a call to [sqlite3_free()] 6502 ** prior to assigning a new string to zErrMsg. ^After the error message 6503 ** is delivered up to the client application, the string will be automatically 6504 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6505 */ 6506 struct sqlite3_vtab { 6507 const sqlite3_module *pModule; /* The module for this virtual table */ 6508 int nRef; /* Number of open cursors */ 6509 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6510 /* Virtual table implementations will typically add additional fields */ 6511 }; 6512 6513 /* 6514 ** CAPI3REF: Virtual Table Cursor Object 6515 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6516 ** 6517 ** Every [virtual table module] implementation uses a subclass of the 6518 ** following structure to describe cursors that point into the 6519 ** [virtual table] and are used 6520 ** to loop through the virtual table. Cursors are created using the 6521 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6522 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6523 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6524 ** of the module. Each module implementation will define 6525 ** the content of a cursor structure to suit its own needs. 6526 ** 6527 ** This superclass exists in order to define fields of the cursor that 6528 ** are common to all implementations. 6529 */ 6530 struct sqlite3_vtab_cursor { 6531 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6532 /* Virtual table implementations will typically add additional fields */ 6533 }; 6534 6535 /* 6536 ** CAPI3REF: Declare The Schema Of A Virtual Table 6537 ** 6538 ** ^The [xCreate] and [xConnect] methods of a 6539 ** [virtual table module] call this interface 6540 ** to declare the format (the names and datatypes of the columns) of 6541 ** the virtual tables they implement. 6542 */ 6543 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6544 6545 /* 6546 ** CAPI3REF: Overload A Function For A Virtual Table 6547 ** METHOD: sqlite3 6548 ** 6549 ** ^(Virtual tables can provide alternative implementations of functions 6550 ** using the [xFindFunction] method of the [virtual table module]. 6551 ** But global versions of those functions 6552 ** must exist in order to be overloaded.)^ 6553 ** 6554 ** ^(This API makes sure a global version of a function with a particular 6555 ** name and number of parameters exists. If no such function exists 6556 ** before this API is called, a new function is created.)^ ^The implementation 6557 ** of the new function always causes an exception to be thrown. So 6558 ** the new function is not good for anything by itself. Its only 6559 ** purpose is to be a placeholder function that can be overloaded 6560 ** by a [virtual table]. 6561 */ 6562 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6563 6564 /* 6565 ** The interface to the virtual-table mechanism defined above (back up 6566 ** to a comment remarkably similar to this one) is currently considered 6567 ** to be experimental. The interface might change in incompatible ways. 6568 ** If this is a problem for you, do not use the interface at this time. 6569 ** 6570 ** When the virtual-table mechanism stabilizes, we will declare the 6571 ** interface fixed, support it indefinitely, and remove this comment. 6572 */ 6573 6574 /* 6575 ** CAPI3REF: A Handle To An Open BLOB 6576 ** KEYWORDS: {BLOB handle} {BLOB handles} 6577 ** 6578 ** An instance of this object represents an open BLOB on which 6579 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6580 ** ^Objects of this type are created by [sqlite3_blob_open()] 6581 ** and destroyed by [sqlite3_blob_close()]. 6582 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6583 ** can be used to read or write small subsections of the BLOB. 6584 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6585 */ 6586 typedef struct sqlite3_blob sqlite3_blob; 6587 6588 /* 6589 ** CAPI3REF: Open A BLOB For Incremental I/O 6590 ** METHOD: sqlite3 6591 ** CONSTRUCTOR: sqlite3_blob 6592 ** 6593 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6594 ** in row iRow, column zColumn, table zTable in database zDb; 6595 ** in other words, the same BLOB that would be selected by: 6596 ** 6597 ** <pre> 6598 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6599 ** </pre>)^ 6600 ** 6601 ** ^(Parameter zDb is not the filename that contains the database, but 6602 ** rather the symbolic name of the database. For attached databases, this is 6603 ** the name that appears after the AS keyword in the [ATTACH] statement. 6604 ** For the main database file, the database name is "main". For TEMP 6605 ** tables, the database name is "temp".)^ 6606 ** 6607 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 6608 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 6609 ** read-only access. 6610 ** 6611 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6612 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6613 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6614 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6615 ** on *ppBlob after this function it returns. 6616 ** 6617 ** This function fails with SQLITE_ERROR if any of the following are true: 6618 ** <ul> 6619 ** <li> ^(Database zDb does not exist)^, 6620 ** <li> ^(Table zTable does not exist within database zDb)^, 6621 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6622 ** <li> ^(Column zColumn does not exist)^, 6623 ** <li> ^(Row iRow is not present in the table)^, 6624 ** <li> ^(The specified column of row iRow contains a value that is not 6625 ** a TEXT or BLOB value)^, 6626 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6627 ** constraint and the blob is being opened for read/write access)^, 6628 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6629 ** column zColumn is part of a [child key] definition and the blob is 6630 ** being opened for read/write access)^. 6631 ** </ul> 6632 ** 6633 ** ^Unless it returns SQLITE_MISUSE, this function sets the 6634 ** [database connection] error code and message accessible via 6635 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6636 ** 6637 ** A BLOB referenced by sqlite3_blob_open() may be read using the 6638 ** [sqlite3_blob_read()] interface and modified by using 6639 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 6640 ** different row of the same table using the [sqlite3_blob_reopen()] 6641 ** interface. However, the column, table, or database of a [BLOB handle] 6642 ** cannot be changed after the [BLOB handle] is opened. 6643 ** 6644 ** ^(If the row that a BLOB handle points to is modified by an 6645 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6646 ** then the BLOB handle is marked as "expired". 6647 ** This is true if any column of the row is changed, even a column 6648 ** other than the one the BLOB handle is open on.)^ 6649 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6650 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6651 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 6652 ** rolled back by the expiration of the BLOB. Such changes will eventually 6653 ** commit if the transaction continues to completion.)^ 6654 ** 6655 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6656 ** the opened blob. ^The size of a blob may not be changed by this 6657 ** interface. Use the [UPDATE] SQL command to change the size of a 6658 ** blob. 6659 ** 6660 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6661 ** and the built-in [zeroblob] SQL function may be used to create a 6662 ** zero-filled blob to read or write using the incremental-blob interface. 6663 ** 6664 ** To avoid a resource leak, every open [BLOB handle] should eventually 6665 ** be released by a call to [sqlite3_blob_close()]. 6666 ** 6667 ** See also: [sqlite3_blob_close()], 6668 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 6669 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 6670 */ 6671 SQLITE_API int sqlite3_blob_open( 6672 sqlite3*, 6673 const char *zDb, 6674 const char *zTable, 6675 const char *zColumn, 6676 sqlite3_int64 iRow, 6677 int flags, 6678 sqlite3_blob **ppBlob 6679 ); 6680 6681 /* 6682 ** CAPI3REF: Move a BLOB Handle to a New Row 6683 ** METHOD: sqlite3_blob 6684 ** 6685 ** ^This function is used to move an existing [BLOB handle] so that it points 6686 ** to a different row of the same database table. ^The new row is identified 6687 ** by the rowid value passed as the second argument. Only the row can be 6688 ** changed. ^The database, table and column on which the blob handle is open 6689 ** remain the same. Moving an existing [BLOB handle] to a new row is 6690 ** faster than closing the existing handle and opening a new one. 6691 ** 6692 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6693 ** it must exist and there must be either a blob or text value stored in 6694 ** the nominated column.)^ ^If the new row is not present in the table, or if 6695 ** it does not contain a blob or text value, or if another error occurs, an 6696 ** SQLite error code is returned and the blob handle is considered aborted. 6697 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6698 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6699 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6700 ** always returns zero. 6701 ** 6702 ** ^This function sets the database handle error code and message. 6703 */ 6704 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6705 6706 /* 6707 ** CAPI3REF: Close A BLOB Handle 6708 ** DESTRUCTOR: sqlite3_blob 6709 ** 6710 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6711 ** unconditionally. Even if this routine returns an error code, the 6712 ** handle is still closed.)^ 6713 ** 6714 ** ^If the blob handle being closed was opened for read-write access, and if 6715 ** the database is in auto-commit mode and there are no other open read-write 6716 ** blob handles or active write statements, the current transaction is 6717 ** committed. ^If an error occurs while committing the transaction, an error 6718 ** code is returned and the transaction rolled back. 6719 ** 6720 ** Calling this function with an argument that is not a NULL pointer or an 6721 ** open blob handle results in undefined behaviour. ^Calling this routine 6722 ** with a null pointer (such as would be returned by a failed call to 6723 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6724 ** is passed a valid open blob handle, the values returned by the 6725 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6726 */ 6727 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 6728 6729 /* 6730 ** CAPI3REF: Return The Size Of An Open BLOB 6731 ** METHOD: sqlite3_blob 6732 ** 6733 ** ^Returns the size in bytes of the BLOB accessible via the 6734 ** successfully opened [BLOB handle] in its only argument. ^The 6735 ** incremental blob I/O routines can only read or overwriting existing 6736 ** blob content; they cannot change the size of a blob. 6737 ** 6738 ** This routine only works on a [BLOB handle] which has been created 6739 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6740 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6741 ** to this routine results in undefined and probably undesirable behavior. 6742 */ 6743 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 6744 6745 /* 6746 ** CAPI3REF: Read Data From A BLOB Incrementally 6747 ** METHOD: sqlite3_blob 6748 ** 6749 ** ^(This function is used to read data from an open [BLOB handle] into a 6750 ** caller-supplied buffer. N bytes of data are copied into buffer Z 6751 ** from the open BLOB, starting at offset iOffset.)^ 6752 ** 6753 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6754 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6755 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 6756 ** ^The size of the blob (and hence the maximum value of N+iOffset) 6757 ** can be determined using the [sqlite3_blob_bytes()] interface. 6758 ** 6759 ** ^An attempt to read from an expired [BLOB handle] fails with an 6760 ** error code of [SQLITE_ABORT]. 6761 ** 6762 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6763 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6764 ** 6765 ** This routine only works on a [BLOB handle] which has been created 6766 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6767 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6768 ** to this routine results in undefined and probably undesirable behavior. 6769 ** 6770 ** See also: [sqlite3_blob_write()]. 6771 */ 6772 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6773 6774 /* 6775 ** CAPI3REF: Write Data Into A BLOB Incrementally 6776 ** METHOD: sqlite3_blob 6777 ** 6778 ** ^(This function is used to write data into an open [BLOB handle] from a 6779 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 6780 ** into the open BLOB, starting at offset iOffset.)^ 6781 ** 6782 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6783 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6784 ** ^Unless SQLITE_MISUSE is returned, this function sets the 6785 ** [database connection] error code and message accessible via 6786 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6787 ** 6788 ** ^If the [BLOB handle] passed as the first argument was not opened for 6789 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6790 ** this function returns [SQLITE_READONLY]. 6791 ** 6792 ** This function may only modify the contents of the BLOB; it is 6793 ** not possible to increase the size of a BLOB using this API. 6794 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6795 ** [SQLITE_ERROR] is returned and no data is written. The size of the 6796 ** BLOB (and hence the maximum value of N+iOffset) can be determined 6797 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6798 ** than zero [SQLITE_ERROR] is returned and no data is written. 6799 ** 6800 ** ^An attempt to write to an expired [BLOB handle] fails with an 6801 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6802 ** before the [BLOB handle] expired are not rolled back by the 6803 ** expiration of the handle, though of course those changes might 6804 ** have been overwritten by the statement that expired the BLOB handle 6805 ** or by other independent statements. 6806 ** 6807 ** This routine only works on a [BLOB handle] which has been created 6808 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6809 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6810 ** to this routine results in undefined and probably undesirable behavior. 6811 ** 6812 ** See also: [sqlite3_blob_read()]. 6813 */ 6814 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6815 6816 /* 6817 ** CAPI3REF: Virtual File System Objects 6818 ** 6819 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6820 ** that SQLite uses to interact 6821 ** with the underlying operating system. Most SQLite builds come with a 6822 ** single default VFS that is appropriate for the host computer. 6823 ** New VFSes can be registered and existing VFSes can be unregistered. 6824 ** The following interfaces are provided. 6825 ** 6826 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6827 ** ^Names are case sensitive. 6828 ** ^Names are zero-terminated UTF-8 strings. 6829 ** ^If there is no match, a NULL pointer is returned. 6830 ** ^If zVfsName is NULL then the default VFS is returned. 6831 ** 6832 ** ^New VFSes are registered with sqlite3_vfs_register(). 6833 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6834 ** ^The same VFS can be registered multiple times without injury. 6835 ** ^To make an existing VFS into the default VFS, register it again 6836 ** with the makeDflt flag set. If two different VFSes with the 6837 ** same name are registered, the behavior is undefined. If a 6838 ** VFS is registered with a name that is NULL or an empty string, 6839 ** then the behavior is undefined. 6840 ** 6841 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6842 ** ^(If the default VFS is unregistered, another VFS is chosen as 6843 ** the default. The choice for the new VFS is arbitrary.)^ 6844 */ 6845 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 6846 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6847 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 6848 6849 /* 6850 ** CAPI3REF: Mutexes 6851 ** 6852 ** The SQLite core uses these routines for thread 6853 ** synchronization. Though they are intended for internal 6854 ** use by SQLite, code that links against SQLite is 6855 ** permitted to use any of these routines. 6856 ** 6857 ** The SQLite source code contains multiple implementations 6858 ** of these mutex routines. An appropriate implementation 6859 ** is selected automatically at compile-time. The following 6860 ** implementations are available in the SQLite core: 6861 ** 6862 ** <ul> 6863 ** <li> SQLITE_MUTEX_PTHREADS 6864 ** <li> SQLITE_MUTEX_W32 6865 ** <li> SQLITE_MUTEX_NOOP 6866 ** </ul> 6867 ** 6868 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 6869 ** that does no real locking and is appropriate for use in 6870 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6871 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6872 ** and Windows. 6873 ** 6874 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6875 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6876 ** implementation is included with the library. In this case the 6877 ** application must supply a custom mutex implementation using the 6878 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6879 ** before calling sqlite3_initialize() or any other public sqlite3_ 6880 ** function that calls sqlite3_initialize(). 6881 ** 6882 ** ^The sqlite3_mutex_alloc() routine allocates a new 6883 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6884 ** routine returns NULL if it is unable to allocate the requested 6885 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 6886 ** integer constants: 6887 ** 6888 ** <ul> 6889 ** <li> SQLITE_MUTEX_FAST 6890 ** <li> SQLITE_MUTEX_RECURSIVE 6891 ** <li> SQLITE_MUTEX_STATIC_MASTER 6892 ** <li> SQLITE_MUTEX_STATIC_MEM 6893 ** <li> SQLITE_MUTEX_STATIC_OPEN 6894 ** <li> SQLITE_MUTEX_STATIC_PRNG 6895 ** <li> SQLITE_MUTEX_STATIC_LRU 6896 ** <li> SQLITE_MUTEX_STATIC_PMEM 6897 ** <li> SQLITE_MUTEX_STATIC_APP1 6898 ** <li> SQLITE_MUTEX_STATIC_APP2 6899 ** <li> SQLITE_MUTEX_STATIC_APP3 6900 ** <li> SQLITE_MUTEX_STATIC_VFS1 6901 ** <li> SQLITE_MUTEX_STATIC_VFS2 6902 ** <li> SQLITE_MUTEX_STATIC_VFS3 6903 ** </ul> 6904 ** 6905 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6906 ** cause sqlite3_mutex_alloc() to create 6907 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6908 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6909 ** The mutex implementation does not need to make a distinction 6910 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6911 ** not want to. SQLite will only request a recursive mutex in 6912 ** cases where it really needs one. If a faster non-recursive mutex 6913 ** implementation is available on the host platform, the mutex subsystem 6914 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 6915 ** 6916 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6917 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6918 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 6919 ** used by the current version of SQLite. Future versions of SQLite 6920 ** may add additional static mutexes. Static mutexes are for internal 6921 ** use by SQLite only. Applications that use SQLite mutexes should 6922 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6923 ** SQLITE_MUTEX_RECURSIVE. 6924 ** 6925 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6926 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6927 ** returns a different mutex on every call. ^For the static 6928 ** mutex types, the same mutex is returned on every call that has 6929 ** the same type number. 6930 ** 6931 ** ^The sqlite3_mutex_free() routine deallocates a previously 6932 ** allocated dynamic mutex. Attempting to deallocate a static 6933 ** mutex results in undefined behavior. 6934 ** 6935 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6936 ** to enter a mutex. ^If another thread is already within the mutex, 6937 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6938 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6939 ** upon successful entry. ^(Mutexes created using 6940 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6941 ** In such cases, the 6942 ** mutex must be exited an equal number of times before another thread 6943 ** can enter.)^ If the same thread tries to enter any mutex other 6944 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6945 ** 6946 ** ^(Some systems (for example, Windows 95) do not support the operation 6947 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6948 ** will always return SQLITE_BUSY. The SQLite core only ever uses 6949 ** sqlite3_mutex_try() as an optimization so this is acceptable 6950 ** behavior.)^ 6951 ** 6952 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 6953 ** previously entered by the same thread. The behavior 6954 ** is undefined if the mutex is not currently entered by the 6955 ** calling thread or is not currently allocated. 6956 ** 6957 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6958 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6959 ** behave as no-ops. 6960 ** 6961 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6962 */ 6963 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 6964 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 6965 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 6966 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 6967 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 6968 6969 /* 6970 ** CAPI3REF: Mutex Methods Object 6971 ** 6972 ** An instance of this structure defines the low-level routines 6973 ** used to allocate and use mutexes. 6974 ** 6975 ** Usually, the default mutex implementations provided by SQLite are 6976 ** sufficient, however the application has the option of substituting a custom 6977 ** implementation for specialized deployments or systems for which SQLite 6978 ** does not provide a suitable implementation. In this case, the application 6979 ** creates and populates an instance of this structure to pass 6980 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6981 ** Additionally, an instance of this structure can be used as an 6982 ** output variable when querying the system for the current mutex 6983 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6984 ** 6985 ** ^The xMutexInit method defined by this structure is invoked as 6986 ** part of system initialization by the sqlite3_initialize() function. 6987 ** ^The xMutexInit routine is called by SQLite exactly once for each 6988 ** effective call to [sqlite3_initialize()]. 6989 ** 6990 ** ^The xMutexEnd method defined by this structure is invoked as 6991 ** part of system shutdown by the sqlite3_shutdown() function. The 6992 ** implementation of this method is expected to release all outstanding 6993 ** resources obtained by the mutex methods implementation, especially 6994 ** those obtained by the xMutexInit method. ^The xMutexEnd() 6995 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6996 ** 6997 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6998 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6999 ** xMutexNotheld) implement the following interfaces (respectively): 7000 ** 7001 ** <ul> 7002 ** <li> [sqlite3_mutex_alloc()] </li> 7003 ** <li> [sqlite3_mutex_free()] </li> 7004 ** <li> [sqlite3_mutex_enter()] </li> 7005 ** <li> [sqlite3_mutex_try()] </li> 7006 ** <li> [sqlite3_mutex_leave()] </li> 7007 ** <li> [sqlite3_mutex_held()] </li> 7008 ** <li> [sqlite3_mutex_notheld()] </li> 7009 ** </ul>)^ 7010 ** 7011 ** The only difference is that the public sqlite3_XXX functions enumerated 7012 ** above silently ignore any invocations that pass a NULL pointer instead 7013 ** of a valid mutex handle. The implementations of the methods defined 7014 ** by this structure are not required to handle this case, the results 7015 ** of passing a NULL pointer instead of a valid mutex handle are undefined 7016 ** (i.e. it is acceptable to provide an implementation that segfaults if 7017 ** it is passed a NULL pointer). 7018 ** 7019 ** The xMutexInit() method must be threadsafe. It must be harmless to 7020 ** invoke xMutexInit() multiple times within the same process and without 7021 ** intervening calls to xMutexEnd(). Second and subsequent calls to 7022 ** xMutexInit() must be no-ops. 7023 ** 7024 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7025 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7026 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7027 ** memory allocation for a fast or recursive mutex. 7028 ** 7029 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7030 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7031 ** If xMutexInit fails in any way, it is expected to clean up after itself 7032 ** prior to returning. 7033 */ 7034 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7035 struct sqlite3_mutex_methods { 7036 int (*xMutexInit)(void); 7037 int (*xMutexEnd)(void); 7038 sqlite3_mutex *(*xMutexAlloc)(int); 7039 void (*xMutexFree)(sqlite3_mutex *); 7040 void (*xMutexEnter)(sqlite3_mutex *); 7041 int (*xMutexTry)(sqlite3_mutex *); 7042 void (*xMutexLeave)(sqlite3_mutex *); 7043 int (*xMutexHeld)(sqlite3_mutex *); 7044 int (*xMutexNotheld)(sqlite3_mutex *); 7045 }; 7046 7047 /* 7048 ** CAPI3REF: Mutex Verification Routines 7049 ** 7050 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7051 ** are intended for use inside assert() statements. The SQLite core 7052 ** never uses these routines except inside an assert() and applications 7053 ** are advised to follow the lead of the core. The SQLite core only 7054 ** provides implementations for these routines when it is compiled 7055 ** with the SQLITE_DEBUG flag. External mutex implementations 7056 ** are only required to provide these routines if SQLITE_DEBUG is 7057 ** defined and if NDEBUG is not defined. 7058 ** 7059 ** These routines should return true if the mutex in their argument 7060 ** is held or not held, respectively, by the calling thread. 7061 ** 7062 ** The implementation is not required to provide versions of these 7063 ** routines that actually work. If the implementation does not provide working 7064 ** versions of these routines, it should at least provide stubs that always 7065 ** return true so that one does not get spurious assertion failures. 7066 ** 7067 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 7068 ** the routine should return 1. This seems counter-intuitive since 7069 ** clearly the mutex cannot be held if it does not exist. But 7070 ** the reason the mutex does not exist is because the build is not 7071 ** using mutexes. And we do not want the assert() containing the 7072 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 7073 ** the appropriate thing to do. The sqlite3_mutex_notheld() 7074 ** interface should also return 1 when given a NULL pointer. 7075 */ 7076 #ifndef NDEBUG 7077 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 7078 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 7079 #endif 7080 7081 /* 7082 ** CAPI3REF: Mutex Types 7083 ** 7084 ** The [sqlite3_mutex_alloc()] interface takes a single argument 7085 ** which is one of these integer constants. 7086 ** 7087 ** The set of static mutexes may change from one SQLite release to the 7088 ** next. Applications that override the built-in mutex logic must be 7089 ** prepared to accommodate additional static mutexes. 7090 */ 7091 #define SQLITE_MUTEX_FAST 0 7092 #define SQLITE_MUTEX_RECURSIVE 1 7093 #define SQLITE_MUTEX_STATIC_MASTER 2 7094 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7095 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7096 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7097 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7098 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7099 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7100 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7101 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7102 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7103 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7104 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7105 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7106 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7107 7108 /* 7109 ** CAPI3REF: Retrieve the mutex for a database connection 7110 ** METHOD: sqlite3 7111 ** 7112 ** ^This interface returns a pointer the [sqlite3_mutex] object that 7113 ** serializes access to the [database connection] given in the argument 7114 ** when the [threading mode] is Serialized. 7115 ** ^If the [threading mode] is Single-thread or Multi-thread then this 7116 ** routine returns a NULL pointer. 7117 */ 7118 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7119 7120 /* 7121 ** CAPI3REF: Low-Level Control Of Database Files 7122 ** METHOD: sqlite3 7123 ** KEYWORDS: {file control} 7124 ** 7125 ** ^The [sqlite3_file_control()] interface makes a direct call to the 7126 ** xFileControl method for the [sqlite3_io_methods] object associated 7127 ** with a particular database identified by the second argument. ^The 7128 ** name of the database is "main" for the main database or "temp" for the 7129 ** TEMP database, or the name that appears after the AS keyword for 7130 ** databases that are added using the [ATTACH] SQL command. 7131 ** ^A NULL pointer can be used in place of "main" to refer to the 7132 ** main database file. 7133 ** ^The third and fourth parameters to this routine 7134 ** are passed directly through to the second and third parameters of 7135 ** the xFileControl method. ^The return value of the xFileControl 7136 ** method becomes the return value of this routine. 7137 ** 7138 ** A few opcodes for [sqlite3_file_control()] are handled directly 7139 ** by the SQLite core and never invoke the 7140 ** sqlite3_io_methods.xFileControl method. 7141 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7142 ** a pointer to the underlying [sqlite3_file] object to be written into 7143 ** the space pointed to by the 4th parameter. The 7144 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 7145 ** the [sqlite3_file] object associated with the journal file instead of 7146 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 7147 ** a pointer to the underlying [sqlite3_vfs] object for the file. 7148 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 7149 ** from the pager. 7150 ** 7151 ** ^If the second parameter (zDbName) does not match the name of any 7152 ** open database file, then SQLITE_ERROR is returned. ^This error 7153 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 7154 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 7155 ** also return SQLITE_ERROR. There is no way to distinguish between 7156 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7157 ** xFileControl method. 7158 ** 7159 ** See also: [file control opcodes] 7160 */ 7161 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7162 7163 /* 7164 ** CAPI3REF: Testing Interface 7165 ** 7166 ** ^The sqlite3_test_control() interface is used to read out internal 7167 ** state of SQLite and to inject faults into SQLite for testing 7168 ** purposes. ^The first parameter is an operation code that determines 7169 ** the number, meaning, and operation of all subsequent parameters. 7170 ** 7171 ** This interface is not for use by applications. It exists solely 7172 ** for verifying the correct operation of the SQLite library. Depending 7173 ** on how the SQLite library is compiled, this interface might not exist. 7174 ** 7175 ** The details of the operation codes, their meanings, the parameters 7176 ** they take, and what they do are all subject to change without notice. 7177 ** Unlike most of the SQLite API, this function is not guaranteed to 7178 ** operate consistently from one release to the next. 7179 */ 7180 SQLITE_API int sqlite3_test_control(int op, ...); 7181 7182 /* 7183 ** CAPI3REF: Testing Interface Operation Codes 7184 ** 7185 ** These constants are the valid operation code parameters used 7186 ** as the first argument to [sqlite3_test_control()]. 7187 ** 7188 ** These parameters and their meanings are subject to change 7189 ** without notice. These values are for testing purposes only. 7190 ** Applications should not use any of these parameters or the 7191 ** [sqlite3_test_control()] interface. 7192 */ 7193 #define SQLITE_TESTCTRL_FIRST 5 7194 #define SQLITE_TESTCTRL_PRNG_SAVE 5 7195 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 7196 #define SQLITE_TESTCTRL_PRNG_RESET 7 7197 #define SQLITE_TESTCTRL_BITVEC_TEST 8 7198 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 7199 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7200 #define SQLITE_TESTCTRL_PENDING_BYTE 11 7201 #define SQLITE_TESTCTRL_ASSERT 12 7202 #define SQLITE_TESTCTRL_ALWAYS 13 7203 #define SQLITE_TESTCTRL_RESERVE 14 7204 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7205 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7206 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7207 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7208 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7209 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7210 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7211 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7212 #define SQLITE_TESTCTRL_BYTEORDER 22 7213 #define SQLITE_TESTCTRL_ISINIT 23 7214 #define SQLITE_TESTCTRL_SORTER_MMAP 24 7215 #define SQLITE_TESTCTRL_IMPOSTER 25 7216 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7217 #define SQLITE_TESTCTRL_LAST 26 /* Largest TESTCTRL */ 7218 7219 /* 7220 ** CAPI3REF: SQL Keyword Checking 7221 ** 7222 ** These routines provide access to the set of SQL language keywords 7223 ** recognized by SQLite. Applications can uses these routines to determine 7224 ** whether or not a specific identifier needs to be escaped (for example, 7225 ** by enclosing in double-quotes) so as not to confuse the parser. 7226 ** 7227 ** The sqlite3_keyword_count() interface returns the number of distinct 7228 ** keywords understood by SQLite. 7229 ** 7230 ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 7231 ** makes *Z point to that keyword expressed as UTF8 and writes the number 7232 ** of bytes in the keyword into *L. The string that *Z points to is not 7233 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 7234 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 7235 ** or L are NULL or invalid pointers then calls to 7236 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 7237 ** 7238 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 7239 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 7240 ** if it is and zero if not. 7241 ** 7242 ** The parser used by SQLite is forgiving. It is often possible to use 7243 ** a keyword as an identifier as long as such use does not result in a 7244 ** parsing ambiguity. For example, the statement 7245 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 7246 ** creates a new table named "BEGIN" with three columns named 7247 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 7248 ** using keywords as identifiers. Common techniques used to avoid keyword 7249 ** name collisions include: 7250 ** <ul> 7251 ** <li> Put all identifier names inside double-quotes. This is the official 7252 ** SQL way to escape identifier names. 7253 ** <li> Put identifier names inside [...]. This is not standard SQL, 7254 ** but it is what SQL Server does and so lots of programmers use this 7255 ** technique. 7256 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start 7257 ** with "Z". 7258 ** <li> Include a digit somewhere in every identifier name. 7259 ** </ul> 7260 ** 7261 ** Note that the number of keywords understood by SQLite can depend on 7262 ** compile-time options. For example, "VACUUM" is not a keyword if 7263 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 7264 ** new keywords may be added to future releases of SQLite. 7265 */ 7266 SQLITE_API int sqlite3_keyword_count(void); 7267 SQLITE_API int sqlite3_keyword_name(int,const char**,int*); 7268 SQLITE_API int sqlite3_keyword_check(const char*,int); 7269 7270 /* 7271 ** CAPI3REF: Dynamic String Object 7272 ** KEYWORDS: {dynamic string} 7273 ** 7274 ** An instance of the sqlite3_str object contains a dynamically-sized 7275 ** string under construction. 7276 ** 7277 ** The lifecycle of an sqlite3_str object is as follows: 7278 ** <ol> 7279 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 7280 ** <li> ^Text is appended to the sqlite3_str object using various 7281 ** methods, such as [sqlite3_str_appendf()]. 7282 ** <li> ^The sqlite3_str object is destroyed and the string it created 7283 ** is returned using the [sqlite3_str_finish()] interface. 7284 ** </ol> 7285 */ 7286 typedef struct sqlite3_str sqlite3_str; 7287 7288 /* 7289 ** CAPI3REF: Create A New Dynamic String Object 7290 ** CONSTRUCTOR: sqlite3_str 7291 ** 7292 ** ^The [sqlite3_str_new(D)] interface allocates and initializes 7293 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 7294 ** [sqlite3_str_new()] must be freed by a subsequent call to 7295 ** [sqlite3_str_finish(X)]. 7296 ** 7297 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 7298 ** valid [sqlite3_str] object, though in the event of an out-of-memory 7299 ** error the returned object might be a special singleton that will 7300 ** silently reject new text, always return SQLITE_NOMEM from 7301 ** [sqlite3_str_errcode()], always return 0 for 7302 ** [sqlite3_str_length()], and always return NULL from 7303 ** [sqlite3_str_finish(X)]. It is always safe to use the value 7304 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 7305 ** to any of the other [sqlite3_str] methods. 7306 ** 7307 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 7308 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 7309 ** length of the string contained in the [sqlite3_str] object will be 7310 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 7311 ** of [SQLITE_MAX_LENGTH]. 7312 */ 7313 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*); 7314 7315 /* 7316 ** CAPI3REF: Finalize A Dynamic String 7317 ** DESTRUCTOR: sqlite3_str 7318 ** 7319 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 7320 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 7321 ** that contains the constructed string. The calling application should 7322 ** pass the returned value to [sqlite3_free()] to avoid a memory leak. 7323 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 7324 ** errors were encountered during construction of the string. ^The 7325 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 7326 ** string in [sqlite3_str] object X is zero bytes long. 7327 */ 7328 SQLITE_API char *sqlite3_str_finish(sqlite3_str*); 7329 7330 /* 7331 ** CAPI3REF: Add Content To A Dynamic String 7332 ** METHOD: sqlite3_str 7333 ** 7334 ** These interfaces add content to an sqlite3_str object previously obtained 7335 ** from [sqlite3_str_new()]. 7336 ** 7337 ** ^The [sqlite3_str_appendf(X,F,...)] and 7338 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 7339 ** functionality of SQLite to append formatted text onto the end of 7340 ** [sqlite3_str] object X. 7341 ** 7342 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 7343 ** onto the end of the [sqlite3_str] object X. N must be non-negative. 7344 ** S must contain at least N non-zero bytes of content. To append a 7345 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 7346 ** method instead. 7347 ** 7348 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 7349 ** zero-terminated string S onto the end of [sqlite3_str] object X. 7350 ** 7351 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 7352 ** single-byte character C onto the end of [sqlite3_str] object X. 7353 ** ^This method can be used, for example, to add whitespace indentation. 7354 ** 7355 ** ^The [sqlite3_str_reset(X)] method resets the string under construction 7356 ** inside [sqlite3_str] object X back to zero bytes in length. 7357 ** 7358 ** These methods do not return a result code. ^If an error occurs, that fact 7359 ** is recorded in the [sqlite3_str] object and can be recovered by a 7360 ** subsequent call to [sqlite3_str_errcode(X)]. 7361 */ 7362 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 7363 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 7364 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 7365 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 7366 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 7367 SQLITE_API void sqlite3_str_reset(sqlite3_str*); 7368 7369 /* 7370 ** CAPI3REF: Status Of A Dynamic String 7371 ** METHOD: sqlite3_str 7372 ** 7373 ** These interfaces return the current status of an [sqlite3_str] object. 7374 ** 7375 ** ^If any prior errors have occurred while constructing the dynamic string 7376 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 7377 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 7378 ** [SQLITE_NOMEM] following any out-of-memory error, or 7379 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 7380 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 7381 ** 7382 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 7383 ** of the dynamic string under construction in [sqlite3_str] object X. 7384 ** ^The length returned by [sqlite3_str_length(X)] does not include the 7385 ** zero-termination byte. 7386 ** 7387 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current 7388 ** content of the dynamic string under construction in X. The value 7389 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 7390 ** and might be freed or altered by any subsequent method on the same 7391 ** [sqlite3_str] object. Applications must not used the pointer returned 7392 ** [sqlite3_str_value(X)] after any subsequent method call on the same 7393 ** object. ^Applications may change the content of the string returned 7394 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes 7395 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 7396 ** write any byte after any subsequent sqlite3_str method call. 7397 */ 7398 SQLITE_API int sqlite3_str_errcode(sqlite3_str*); 7399 SQLITE_API int sqlite3_str_length(sqlite3_str*); 7400 SQLITE_API char *sqlite3_str_value(sqlite3_str*); 7401 7402 /* 7403 ** CAPI3REF: SQLite Runtime Status 7404 ** 7405 ** ^These interfaces are used to retrieve runtime status information 7406 ** about the performance of SQLite, and optionally to reset various 7407 ** highwater marks. ^The first argument is an integer code for 7408 ** the specific parameter to measure. ^(Recognized integer codes 7409 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 7410 ** ^The current value of the parameter is returned into *pCurrent. 7411 ** ^The highest recorded value is returned in *pHighwater. ^If the 7412 ** resetFlag is true, then the highest record value is reset after 7413 ** *pHighwater is written. ^(Some parameters do not record the highest 7414 ** value. For those parameters 7415 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 7416 ** ^(Other parameters record only the highwater mark and not the current 7417 ** value. For these latter parameters nothing is written into *pCurrent.)^ 7418 ** 7419 ** ^The sqlite3_status() and sqlite3_status64() routines return 7420 ** SQLITE_OK on success and a non-zero [error code] on failure. 7421 ** 7422 ** If either the current value or the highwater mark is too large to 7423 ** be represented by a 32-bit integer, then the values returned by 7424 ** sqlite3_status() are undefined. 7425 ** 7426 ** See also: [sqlite3_db_status()] 7427 */ 7428 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 7429 SQLITE_API int sqlite3_status64( 7430 int op, 7431 sqlite3_int64 *pCurrent, 7432 sqlite3_int64 *pHighwater, 7433 int resetFlag 7434 ); 7435 7436 7437 /* 7438 ** CAPI3REF: Status Parameters 7439 ** KEYWORDS: {status parameters} 7440 ** 7441 ** These integer constants designate various run-time status parameters 7442 ** that can be returned by [sqlite3_status()]. 7443 ** 7444 ** <dl> 7445 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 7446 ** <dd>This parameter is the current amount of memory checked out 7447 ** using [sqlite3_malloc()], either directly or indirectly. The 7448 ** figure includes calls made to [sqlite3_malloc()] by the application 7449 ** and internal memory usage by the SQLite library. Auxiliary page-cache 7450 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 7451 ** this parameter. The amount returned is the sum of the allocation 7452 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 7453 ** 7454 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 7455 ** <dd>This parameter records the largest memory allocation request 7456 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 7457 ** internal equivalents). Only the value returned in the 7458 ** *pHighwater parameter to [sqlite3_status()] is of interest. 7459 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 7460 ** 7461 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 7462 ** <dd>This parameter records the number of separate memory allocations 7463 ** currently checked out.</dd>)^ 7464 ** 7465 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 7466 ** <dd>This parameter returns the number of pages used out of the 7467 ** [pagecache memory allocator] that was configured using 7468 ** [SQLITE_CONFIG_PAGECACHE]. The 7469 ** value returned is in pages, not in bytes.</dd>)^ 7470 ** 7471 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 7472 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 7473 ** <dd>This parameter returns the number of bytes of page cache 7474 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 7475 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 7476 ** returned value includes allocations that overflowed because they 7477 ** where too large (they were larger than the "sz" parameter to 7478 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 7479 ** no space was left in the page cache.</dd>)^ 7480 ** 7481 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 7482 ** <dd>This parameter records the largest memory allocation request 7483 ** handed to [pagecache memory allocator]. Only the value returned in the 7484 ** *pHighwater parameter to [sqlite3_status()] is of interest. 7485 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 7486 ** 7487 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 7488 ** <dd>No longer used.</dd> 7489 ** 7490 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 7491 ** <dd>No longer used.</dd> 7492 ** 7493 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 7494 ** <dd>No longer used.</dd> 7495 ** 7496 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 7497 ** <dd>The *pHighwater parameter records the deepest parser stack. 7498 ** The *pCurrent value is undefined. The *pHighwater value is only 7499 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 7500 ** </dl> 7501 ** 7502 ** New status parameters may be added from time to time. 7503 */ 7504 #define SQLITE_STATUS_MEMORY_USED 0 7505 #define SQLITE_STATUS_PAGECACHE_USED 1 7506 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 7507 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 7508 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 7509 #define SQLITE_STATUS_MALLOC_SIZE 5 7510 #define SQLITE_STATUS_PARSER_STACK 6 7511 #define SQLITE_STATUS_PAGECACHE_SIZE 7 7512 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 7513 #define SQLITE_STATUS_MALLOC_COUNT 9 7514 7515 /* 7516 ** CAPI3REF: Database Connection Status 7517 ** METHOD: sqlite3 7518 ** 7519 ** ^This interface is used to retrieve runtime status information 7520 ** about a single [database connection]. ^The first argument is the 7521 ** database connection object to be interrogated. ^The second argument 7522 ** is an integer constant, taken from the set of 7523 ** [SQLITE_DBSTATUS options], that 7524 ** determines the parameter to interrogate. The set of 7525 ** [SQLITE_DBSTATUS options] is likely 7526 ** to grow in future releases of SQLite. 7527 ** 7528 ** ^The current value of the requested parameter is written into *pCur 7529 ** and the highest instantaneous value is written into *pHiwtr. ^If 7530 ** the resetFlg is true, then the highest instantaneous value is 7531 ** reset back down to the current value. 7532 ** 7533 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 7534 ** non-zero [error code] on failure. 7535 ** 7536 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 7537 */ 7538 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 7539 7540 /* 7541 ** CAPI3REF: Status Parameters for database connections 7542 ** KEYWORDS: {SQLITE_DBSTATUS options} 7543 ** 7544 ** These constants are the available integer "verbs" that can be passed as 7545 ** the second argument to the [sqlite3_db_status()] interface. 7546 ** 7547 ** New verbs may be added in future releases of SQLite. Existing verbs 7548 ** might be discontinued. Applications should check the return code from 7549 ** [sqlite3_db_status()] to make sure that the call worked. 7550 ** The [sqlite3_db_status()] interface will return a non-zero error code 7551 ** if a discontinued or unsupported verb is invoked. 7552 ** 7553 ** <dl> 7554 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 7555 ** <dd>This parameter returns the number of lookaside memory slots currently 7556 ** checked out.</dd>)^ 7557 ** 7558 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 7559 ** <dd>This parameter returns the number malloc attempts that were 7560 ** satisfied using lookaside memory. Only the high-water value is meaningful; 7561 ** the current value is always zero.)^ 7562 ** 7563 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 7564 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 7565 ** <dd>This parameter returns the number malloc attempts that might have 7566 ** been satisfied using lookaside memory but failed due to the amount of 7567 ** memory requested being larger than the lookaside slot size. 7568 ** Only the high-water value is meaningful; 7569 ** the current value is always zero.)^ 7570 ** 7571 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 7572 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 7573 ** <dd>This parameter returns the number malloc attempts that might have 7574 ** been satisfied using lookaside memory but failed due to all lookaside 7575 ** memory already being in use. 7576 ** Only the high-water value is meaningful; 7577 ** the current value is always zero.)^ 7578 ** 7579 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 7580 ** <dd>This parameter returns the approximate number of bytes of heap 7581 ** memory used by all pager caches associated with the database connection.)^ 7582 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 7583 ** 7584 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 7585 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 7586 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 7587 ** pager cache is shared between two or more connections the bytes of heap 7588 ** memory used by that pager cache is divided evenly between the attached 7589 ** connections.)^ In other words, if none of the pager caches associated 7590 ** with the database connection are shared, this request returns the same 7591 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 7592 ** shared, the value returned by this call will be smaller than that returned 7593 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 7594 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 7595 ** 7596 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 7597 ** <dd>This parameter returns the approximate number of bytes of heap 7598 ** memory used to store the schema for all databases associated 7599 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 7600 ** ^The full amount of memory used by the schemas is reported, even if the 7601 ** schema memory is shared with other database connections due to 7602 ** [shared cache mode] being enabled. 7603 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 7604 ** 7605 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 7606 ** <dd>This parameter returns the approximate number of bytes of heap 7607 ** and lookaside memory used by all prepared statements associated with 7608 ** the database connection.)^ 7609 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 7610 ** </dd> 7611 ** 7612 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 7613 ** <dd>This parameter returns the number of pager cache hits that have 7614 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 7615 ** is always 0. 7616 ** </dd> 7617 ** 7618 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 7619 ** <dd>This parameter returns the number of pager cache misses that have 7620 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 7621 ** is always 0. 7622 ** </dd> 7623 ** 7624 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 7625 ** <dd>This parameter returns the number of dirty cache entries that have 7626 ** been written to disk. Specifically, the number of pages written to the 7627 ** wal file in wal mode databases, or the number of pages written to the 7628 ** database file in rollback mode databases. Any pages written as part of 7629 ** transaction rollback or database recovery operations are not included. 7630 ** If an IO or other error occurs while writing a page to disk, the effect 7631 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 7632 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 7633 ** </dd> 7634 ** 7635 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 7636 ** <dd>This parameter returns the number of dirty cache entries that have 7637 ** been written to disk in the middle of a transaction due to the page 7638 ** cache overflowing. Transactions are more efficient if they are written 7639 ** to disk all at once. When pages spill mid-transaction, that introduces 7640 ** additional overhead. This parameter can be used help identify 7641 ** inefficiencies that can be resolve by increasing the cache size. 7642 ** </dd> 7643 ** 7644 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 7645 ** <dd>This parameter returns zero for the current value if and only if 7646 ** all foreign key constraints (deferred or immediate) have been 7647 ** resolved.)^ ^The highwater mark is always 0. 7648 ** </dd> 7649 ** </dl> 7650 */ 7651 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 7652 #define SQLITE_DBSTATUS_CACHE_USED 1 7653 #define SQLITE_DBSTATUS_SCHEMA_USED 2 7654 #define SQLITE_DBSTATUS_STMT_USED 3 7655 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 7656 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 7657 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 7658 #define SQLITE_DBSTATUS_CACHE_HIT 7 7659 #define SQLITE_DBSTATUS_CACHE_MISS 8 7660 #define SQLITE_DBSTATUS_CACHE_WRITE 9 7661 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 7662 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 7663 #define SQLITE_DBSTATUS_CACHE_SPILL 12 7664 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 7665 7666 7667 /* 7668 ** CAPI3REF: Prepared Statement Status 7669 ** METHOD: sqlite3_stmt 7670 ** 7671 ** ^(Each prepared statement maintains various 7672 ** [SQLITE_STMTSTATUS counters] that measure the number 7673 ** of times it has performed specific operations.)^ These counters can 7674 ** be used to monitor the performance characteristics of the prepared 7675 ** statements. For example, if the number of table steps greatly exceeds 7676 ** the number of table searches or result rows, that would tend to indicate 7677 ** that the prepared statement is using a full table scan rather than 7678 ** an index. 7679 ** 7680 ** ^(This interface is used to retrieve and reset counter values from 7681 ** a [prepared statement]. The first argument is the prepared statement 7682 ** object to be interrogated. The second argument 7683 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 7684 ** to be interrogated.)^ 7685 ** ^The current value of the requested counter is returned. 7686 ** ^If the resetFlg is true, then the counter is reset to zero after this 7687 ** interface call returns. 7688 ** 7689 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7690 */ 7691 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7692 7693 /* 7694 ** CAPI3REF: Status Parameters for prepared statements 7695 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7696 ** 7697 ** These preprocessor macros define integer codes that name counter 7698 ** values associated with the [sqlite3_stmt_status()] interface. 7699 ** The meanings of the various counters are as follows: 7700 ** 7701 ** <dl> 7702 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7703 ** <dd>^This is the number of times that SQLite has stepped forward in 7704 ** a table as part of a full table scan. Large numbers for this counter 7705 ** may indicate opportunities for performance improvement through 7706 ** careful use of indices.</dd> 7707 ** 7708 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7709 ** <dd>^This is the number of sort operations that have occurred. 7710 ** A non-zero value in this counter may indicate an opportunity to 7711 ** improvement performance through careful use of indices.</dd> 7712 ** 7713 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7714 ** <dd>^This is the number of rows inserted into transient indices that 7715 ** were created automatically in order to help joins run faster. 7716 ** A non-zero value in this counter may indicate an opportunity to 7717 ** improvement performance by adding permanent indices that do not 7718 ** need to be reinitialized each time the statement is run.</dd> 7719 ** 7720 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7721 ** <dd>^This is the number of virtual machine operations executed 7722 ** by the prepared statement if that number is less than or equal 7723 ** to 2147483647. The number of virtual machine operations can be 7724 ** used as a proxy for the total work done by the prepared statement. 7725 ** If the number of virtual machine operations exceeds 2147483647 7726 ** then the value returned by this statement status code is undefined. 7727 ** 7728 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 7729 ** <dd>^This is the number of times that the prepare statement has been 7730 ** automatically regenerated due to schema changes or change to 7731 ** [bound parameters] that might affect the query plan. 7732 ** 7733 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 7734 ** <dd>^This is the number of times that the prepared statement has 7735 ** been run. A single "run" for the purposes of this counter is one 7736 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 7737 ** The counter is incremented on the first [sqlite3_step()] call of each 7738 ** cycle. 7739 ** 7740 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 7741 ** <dd>^This is the approximate number of bytes of heap memory 7742 ** used to store the prepared statement. ^This value is not actually 7743 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 7744 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 7745 ** </dd> 7746 ** </dl> 7747 */ 7748 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7749 #define SQLITE_STMTSTATUS_SORT 2 7750 #define SQLITE_STMTSTATUS_AUTOINDEX 3 7751 #define SQLITE_STMTSTATUS_VM_STEP 4 7752 #define SQLITE_STMTSTATUS_REPREPARE 5 7753 #define SQLITE_STMTSTATUS_RUN 6 7754 #define SQLITE_STMTSTATUS_MEMUSED 99 7755 7756 /* 7757 ** CAPI3REF: Custom Page Cache Object 7758 ** 7759 ** The sqlite3_pcache type is opaque. It is implemented by 7760 ** the pluggable module. The SQLite core has no knowledge of 7761 ** its size or internal structure and never deals with the 7762 ** sqlite3_pcache object except by holding and passing pointers 7763 ** to the object. 7764 ** 7765 ** See [sqlite3_pcache_methods2] for additional information. 7766 */ 7767 typedef struct sqlite3_pcache sqlite3_pcache; 7768 7769 /* 7770 ** CAPI3REF: Custom Page Cache Object 7771 ** 7772 ** The sqlite3_pcache_page object represents a single page in the 7773 ** page cache. The page cache will allocate instances of this 7774 ** object. Various methods of the page cache use pointers to instances 7775 ** of this object as parameters or as their return value. 7776 ** 7777 ** See [sqlite3_pcache_methods2] for additional information. 7778 */ 7779 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 7780 struct sqlite3_pcache_page { 7781 void *pBuf; /* The content of the page */ 7782 void *pExtra; /* Extra information associated with the page */ 7783 }; 7784 7785 /* 7786 ** CAPI3REF: Application Defined Page Cache. 7787 ** KEYWORDS: {page cache} 7788 ** 7789 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 7790 ** register an alternative page cache implementation by passing in an 7791 ** instance of the sqlite3_pcache_methods2 structure.)^ 7792 ** In many applications, most of the heap memory allocated by 7793 ** SQLite is used for the page cache. 7794 ** By implementing a 7795 ** custom page cache using this API, an application can better control 7796 ** the amount of memory consumed by SQLite, the way in which 7797 ** that memory is allocated and released, and the policies used to 7798 ** determine exactly which parts of a database file are cached and for 7799 ** how long. 7800 ** 7801 ** The alternative page cache mechanism is an 7802 ** extreme measure that is only needed by the most demanding applications. 7803 ** The built-in page cache is recommended for most uses. 7804 ** 7805 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 7806 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 7807 ** the application may discard the parameter after the call to 7808 ** [sqlite3_config()] returns.)^ 7809 ** 7810 ** [[the xInit() page cache method]] 7811 ** ^(The xInit() method is called once for each effective 7812 ** call to [sqlite3_initialize()])^ 7813 ** (usually only once during the lifetime of the process). ^(The xInit() 7814 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 7815 ** The intent of the xInit() method is to set up global data structures 7816 ** required by the custom page cache implementation. 7817 ** ^(If the xInit() method is NULL, then the 7818 ** built-in default page cache is used instead of the application defined 7819 ** page cache.)^ 7820 ** 7821 ** [[the xShutdown() page cache method]] 7822 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 7823 ** It can be used to clean up 7824 ** any outstanding resources before process shutdown, if required. 7825 ** ^The xShutdown() method may be NULL. 7826 ** 7827 ** ^SQLite automatically serializes calls to the xInit method, 7828 ** so the xInit method need not be threadsafe. ^The 7829 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 7830 ** not need to be threadsafe either. All other methods must be threadsafe 7831 ** in multithreaded applications. 7832 ** 7833 ** ^SQLite will never invoke xInit() more than once without an intervening 7834 ** call to xShutdown(). 7835 ** 7836 ** [[the xCreate() page cache methods]] 7837 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 7838 ** SQLite will typically create one cache instance for each open database file, 7839 ** though this is not guaranteed. ^The 7840 ** first parameter, szPage, is the size in bytes of the pages that must 7841 ** be allocated by the cache. ^szPage will always a power of two. ^The 7842 ** second parameter szExtra is a number of bytes of extra storage 7843 ** associated with each page cache entry. ^The szExtra parameter will 7844 ** a number less than 250. SQLite will use the 7845 ** extra szExtra bytes on each page to store metadata about the underlying 7846 ** database page on disk. The value passed into szExtra depends 7847 ** on the SQLite version, the target platform, and how SQLite was compiled. 7848 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 7849 ** created will be used to cache database pages of a file stored on disk, or 7850 ** false if it is used for an in-memory database. The cache implementation 7851 ** does not have to do anything special based with the value of bPurgeable; 7852 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 7853 ** never invoke xUnpin() except to deliberately delete a page. 7854 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 7855 ** false will always have the "discard" flag set to true. 7856 ** ^Hence, a cache created with bPurgeable false will 7857 ** never contain any unpinned pages. 7858 ** 7859 ** [[the xCachesize() page cache method]] 7860 ** ^(The xCachesize() method may be called at any time by SQLite to set the 7861 ** suggested maximum cache-size (number of pages stored by) the cache 7862 ** instance passed as the first argument. This is the value configured using 7863 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 7864 ** parameter, the implementation is not required to do anything with this 7865 ** value; it is advisory only. 7866 ** 7867 ** [[the xPagecount() page cache methods]] 7868 ** The xPagecount() method must return the number of pages currently 7869 ** stored in the cache, both pinned and unpinned. 7870 ** 7871 ** [[the xFetch() page cache methods]] 7872 ** The xFetch() method locates a page in the cache and returns a pointer to 7873 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 7874 ** The pBuf element of the returned sqlite3_pcache_page object will be a 7875 ** pointer to a buffer of szPage bytes used to store the content of a 7876 ** single database page. The pExtra element of sqlite3_pcache_page will be 7877 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 7878 ** for each entry in the page cache. 7879 ** 7880 ** The page to be fetched is determined by the key. ^The minimum key value 7881 ** is 1. After it has been retrieved using xFetch, the page is considered 7882 ** to be "pinned". 7883 ** 7884 ** If the requested page is already in the page cache, then the page cache 7885 ** implementation must return a pointer to the page buffer with its content 7886 ** intact. If the requested page is not already in the cache, then the 7887 ** cache implementation should use the value of the createFlag 7888 ** parameter to help it determined what action to take: 7889 ** 7890 ** <table border=1 width=85% align=center> 7891 ** <tr><th> createFlag <th> Behavior when page is not already in cache 7892 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 7893 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 7894 ** Otherwise return NULL. 7895 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 7896 ** NULL if allocating a new page is effectively impossible. 7897 ** </table> 7898 ** 7899 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 7900 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 7901 ** failed.)^ In between the to xFetch() calls, SQLite may 7902 ** attempt to unpin one or more cache pages by spilling the content of 7903 ** pinned pages to disk and synching the operating system disk cache. 7904 ** 7905 ** [[the xUnpin() page cache method]] 7906 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 7907 ** as its second argument. If the third parameter, discard, is non-zero, 7908 ** then the page must be evicted from the cache. 7909 ** ^If the discard parameter is 7910 ** zero, then the page may be discarded or retained at the discretion of 7911 ** page cache implementation. ^The page cache implementation 7912 ** may choose to evict unpinned pages at any time. 7913 ** 7914 ** The cache must not perform any reference counting. A single 7915 ** call to xUnpin() unpins the page regardless of the number of prior calls 7916 ** to xFetch(). 7917 ** 7918 ** [[the xRekey() page cache methods]] 7919 ** The xRekey() method is used to change the key value associated with the 7920 ** page passed as the second argument. If the cache 7921 ** previously contains an entry associated with newKey, it must be 7922 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 7923 ** to be pinned. 7924 ** 7925 ** When SQLite calls the xTruncate() method, the cache must discard all 7926 ** existing cache entries with page numbers (keys) greater than or equal 7927 ** to the value of the iLimit parameter passed to xTruncate(). If any 7928 ** of these pages are pinned, they are implicitly unpinned, meaning that 7929 ** they can be safely discarded. 7930 ** 7931 ** [[the xDestroy() page cache method]] 7932 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 7933 ** All resources associated with the specified cache should be freed. ^After 7934 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 7935 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 7936 ** functions. 7937 ** 7938 ** [[the xShrink() page cache method]] 7939 ** ^SQLite invokes the xShrink() method when it wants the page cache to 7940 ** free up as much of heap memory as possible. The page cache implementation 7941 ** is not obligated to free any memory, but well-behaved implementations should 7942 ** do their best. 7943 */ 7944 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 7945 struct sqlite3_pcache_methods2 { 7946 int iVersion; 7947 void *pArg; 7948 int (*xInit)(void*); 7949 void (*xShutdown)(void*); 7950 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 7951 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7952 int (*xPagecount)(sqlite3_pcache*); 7953 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7954 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 7955 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 7956 unsigned oldKey, unsigned newKey); 7957 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7958 void (*xDestroy)(sqlite3_pcache*); 7959 void (*xShrink)(sqlite3_pcache*); 7960 }; 7961 7962 /* 7963 ** This is the obsolete pcache_methods object that has now been replaced 7964 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 7965 ** retained in the header file for backwards compatibility only. 7966 */ 7967 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 7968 struct sqlite3_pcache_methods { 7969 void *pArg; 7970 int (*xInit)(void*); 7971 void (*xShutdown)(void*); 7972 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 7973 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7974 int (*xPagecount)(sqlite3_pcache*); 7975 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7976 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 7977 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 7978 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7979 void (*xDestroy)(sqlite3_pcache*); 7980 }; 7981 7982 7983 /* 7984 ** CAPI3REF: Online Backup Object 7985 ** 7986 ** The sqlite3_backup object records state information about an ongoing 7987 ** online backup operation. ^The sqlite3_backup object is created by 7988 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 7989 ** [sqlite3_backup_finish()]. 7990 ** 7991 ** See Also: [Using the SQLite Online Backup API] 7992 */ 7993 typedef struct sqlite3_backup sqlite3_backup; 7994 7995 /* 7996 ** CAPI3REF: Online Backup API. 7997 ** 7998 ** The backup API copies the content of one database into another. 7999 ** It is useful either for creating backups of databases or 8000 ** for copying in-memory databases to or from persistent files. 8001 ** 8002 ** See Also: [Using the SQLite Online Backup API] 8003 ** 8004 ** ^SQLite holds a write transaction open on the destination database file 8005 ** for the duration of the backup operation. 8006 ** ^The source database is read-locked only while it is being read; 8007 ** it is not locked continuously for the entire backup operation. 8008 ** ^Thus, the backup may be performed on a live source database without 8009 ** preventing other database connections from 8010 ** reading or writing to the source database while the backup is underway. 8011 ** 8012 ** ^(To perform a backup operation: 8013 ** <ol> 8014 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8015 ** backup, 8016 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8017 ** the data between the two databases, and finally 8018 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8019 ** associated with the backup operation. 8020 ** </ol>)^ 8021 ** There should be exactly one call to sqlite3_backup_finish() for each 8022 ** successful call to sqlite3_backup_init(). 8023 ** 8024 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8025 ** 8026 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8027 ** [database connection] associated with the destination database 8028 ** and the database name, respectively. 8029 ** ^The database name is "main" for the main database, "temp" for the 8030 ** temporary database, or the name specified after the AS keyword in 8031 ** an [ATTACH] statement for an attached database. 8032 ** ^The S and M arguments passed to 8033 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8034 ** and database name of the source database, respectively. 8035 ** ^The source and destination [database connections] (parameters S and D) 8036 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8037 ** an error. 8038 ** 8039 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8040 ** there is already a read or read-write transaction open on the 8041 ** destination database. 8042 ** 8043 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8044 ** returned and an error code and error message are stored in the 8045 ** destination [database connection] D. 8046 ** ^The error code and message for the failed call to sqlite3_backup_init() 8047 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8048 ** [sqlite3_errmsg16()] functions. 8049 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 8050 ** [sqlite3_backup] object. 8051 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8052 ** sqlite3_backup_finish() functions to perform the specified backup 8053 ** operation. 8054 ** 8055 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8056 ** 8057 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8058 ** the source and destination databases specified by [sqlite3_backup] object B. 8059 ** ^If N is negative, all remaining source pages are copied. 8060 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8061 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 8062 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8063 ** from source to destination, then it returns [SQLITE_DONE]. 8064 ** ^If an error occurs while running sqlite3_backup_step(B,N), 8065 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 8066 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8067 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8068 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8069 ** 8070 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8071 ** <ol> 8072 ** <li> the destination database was opened read-only, or 8073 ** <li> the destination database is using write-ahead-log journaling 8074 ** and the destination and source page sizes differ, or 8075 ** <li> the destination database is an in-memory database and the 8076 ** destination and source page sizes differ. 8077 ** </ol>)^ 8078 ** 8079 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8080 ** the [sqlite3_busy_handler | busy-handler function] 8081 ** is invoked (if one is specified). ^If the 8082 ** busy-handler returns non-zero before the lock is available, then 8083 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8084 ** sqlite3_backup_step() can be retried later. ^If the source 8085 ** [database connection] 8086 ** is being used to write to the source database when sqlite3_backup_step() 8087 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8088 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 8089 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8090 ** [SQLITE_READONLY] is returned, then 8091 ** there is no point in retrying the call to sqlite3_backup_step(). These 8092 ** errors are considered fatal.)^ The application must accept 8093 ** that the backup operation has failed and pass the backup operation handle 8094 ** to the sqlite3_backup_finish() to release associated resources. 8095 ** 8096 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8097 ** on the destination file. ^The exclusive lock is not released until either 8098 ** sqlite3_backup_finish() is called or the backup operation is complete 8099 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8100 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 8101 ** lasts for the duration of the sqlite3_backup_step() call. 8102 ** ^Because the source database is not locked between calls to 8103 ** sqlite3_backup_step(), the source database may be modified mid-way 8104 ** through the backup process. ^If the source database is modified by an 8105 ** external process or via a database connection other than the one being 8106 ** used by the backup operation, then the backup will be automatically 8107 ** restarted by the next call to sqlite3_backup_step(). ^If the source 8108 ** database is modified by the using the same database connection as is used 8109 ** by the backup operation, then the backup database is automatically 8110 ** updated at the same time. 8111 ** 8112 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8113 ** 8114 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8115 ** application wishes to abandon the backup operation, the application 8116 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8117 ** ^The sqlite3_backup_finish() interfaces releases all 8118 ** resources associated with the [sqlite3_backup] object. 8119 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8120 ** active write-transaction on the destination database is rolled back. 8121 ** The [sqlite3_backup] object is invalid 8122 ** and may not be used following a call to sqlite3_backup_finish(). 8123 ** 8124 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8125 ** sqlite3_backup_step() errors occurred, regardless or whether or not 8126 ** sqlite3_backup_step() completed. 8127 ** ^If an out-of-memory condition or IO error occurred during any prior 8128 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8129 ** sqlite3_backup_finish() returns the corresponding [error code]. 8130 ** 8131 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8132 ** is not a permanent error and does not affect the return value of 8133 ** sqlite3_backup_finish(). 8134 ** 8135 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8136 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8137 ** 8138 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 8139 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8140 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8141 ** in the source database at the conclusion of the most recent 8142 ** sqlite3_backup_step(). 8143 ** ^(The values returned by these functions are only updated by 8144 ** sqlite3_backup_step(). If the source database is modified in a way that 8145 ** changes the size of the source database or the number of pages remaining, 8146 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 8147 ** and sqlite3_backup_remaining() until after the next 8148 ** sqlite3_backup_step().)^ 8149 ** 8150 ** <b>Concurrent Usage of Database Handles</b> 8151 ** 8152 ** ^The source [database connection] may be used by the application for other 8153 ** purposes while a backup operation is underway or being initialized. 8154 ** ^If SQLite is compiled and configured to support threadsafe database 8155 ** connections, then the source database connection may be used concurrently 8156 ** from within other threads. 8157 ** 8158 ** However, the application must guarantee that the destination 8159 ** [database connection] is not passed to any other API (by any thread) after 8160 ** sqlite3_backup_init() is called and before the corresponding call to 8161 ** sqlite3_backup_finish(). SQLite does not currently check to see 8162 ** if the application incorrectly accesses the destination [database connection] 8163 ** and so no error code is reported, but the operations may malfunction 8164 ** nevertheless. Use of the destination database connection while a 8165 ** backup is in progress might also also cause a mutex deadlock. 8166 ** 8167 ** If running in [shared cache mode], the application must 8168 ** guarantee that the shared cache used by the destination database 8169 ** is not accessed while the backup is running. In practice this means 8170 ** that the application must guarantee that the disk file being 8171 ** backed up to is not accessed by any connection within the process, 8172 ** not just the specific connection that was passed to sqlite3_backup_init(). 8173 ** 8174 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8175 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8176 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8177 ** APIs are not strictly speaking threadsafe. If they are invoked at the 8178 ** same time as another thread is invoking sqlite3_backup_step() it is 8179 ** possible that they return invalid values. 8180 */ 8181 SQLITE_API sqlite3_backup *sqlite3_backup_init( 8182 sqlite3 *pDest, /* Destination database handle */ 8183 const char *zDestName, /* Destination database name */ 8184 sqlite3 *pSource, /* Source database handle */ 8185 const char *zSourceName /* Source database name */ 8186 ); 8187 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8188 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 8189 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 8190 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 8191 8192 /* 8193 ** CAPI3REF: Unlock Notification 8194 ** METHOD: sqlite3 8195 ** 8196 ** ^When running in shared-cache mode, a database operation may fail with 8197 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8198 ** individual tables within the shared-cache cannot be obtained. See 8199 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8200 ** ^This API may be used to register a callback that SQLite will invoke 8201 ** when the connection currently holding the required lock relinquishes it. 8202 ** ^This API is only available if the library was compiled with the 8203 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8204 ** 8205 ** See Also: [Using the SQLite Unlock Notification Feature]. 8206 ** 8207 ** ^Shared-cache locks are released when a database connection concludes 8208 ** its current transaction, either by committing it or rolling it back. 8209 ** 8210 ** ^When a connection (known as the blocked connection) fails to obtain a 8211 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 8212 ** identity of the database connection (the blocking connection) that 8213 ** has locked the required resource is stored internally. ^After an 8214 ** application receives an SQLITE_LOCKED error, it may call the 8215 ** sqlite3_unlock_notify() method with the blocked connection handle as 8216 ** the first argument to register for a callback that will be invoked 8217 ** when the blocking connections current transaction is concluded. ^The 8218 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 8219 ** call that concludes the blocking connections transaction. 8220 ** 8221 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 8222 ** there is a chance that the blocking connection will have already 8223 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 8224 ** If this happens, then the specified callback is invoked immediately, 8225 ** from within the call to sqlite3_unlock_notify().)^ 8226 ** 8227 ** ^If the blocked connection is attempting to obtain a write-lock on a 8228 ** shared-cache table, and more than one other connection currently holds 8229 ** a read-lock on the same table, then SQLite arbitrarily selects one of 8230 ** the other connections to use as the blocking connection. 8231 ** 8232 ** ^(There may be at most one unlock-notify callback registered by a 8233 ** blocked connection. If sqlite3_unlock_notify() is called when the 8234 ** blocked connection already has a registered unlock-notify callback, 8235 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 8236 ** called with a NULL pointer as its second argument, then any existing 8237 ** unlock-notify callback is canceled. ^The blocked connections 8238 ** unlock-notify callback may also be canceled by closing the blocked 8239 ** connection using [sqlite3_close()]. 8240 ** 8241 ** The unlock-notify callback is not reentrant. If an application invokes 8242 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 8243 ** crash or deadlock may be the result. 8244 ** 8245 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 8246 ** returns SQLITE_OK. 8247 ** 8248 ** <b>Callback Invocation Details</b> 8249 ** 8250 ** When an unlock-notify callback is registered, the application provides a 8251 ** single void* pointer that is passed to the callback when it is invoked. 8252 ** However, the signature of the callback function allows SQLite to pass 8253 ** it an array of void* context pointers. The first argument passed to 8254 ** an unlock-notify callback is a pointer to an array of void* pointers, 8255 ** and the second is the number of entries in the array. 8256 ** 8257 ** When a blocking connections transaction is concluded, there may be 8258 ** more than one blocked connection that has registered for an unlock-notify 8259 ** callback. ^If two or more such blocked connections have specified the 8260 ** same callback function, then instead of invoking the callback function 8261 ** multiple times, it is invoked once with the set of void* context pointers 8262 ** specified by the blocked connections bundled together into an array. 8263 ** This gives the application an opportunity to prioritize any actions 8264 ** related to the set of unblocked database connections. 8265 ** 8266 ** <b>Deadlock Detection</b> 8267 ** 8268 ** Assuming that after registering for an unlock-notify callback a 8269 ** database waits for the callback to be issued before taking any further 8270 ** action (a reasonable assumption), then using this API may cause the 8271 ** application to deadlock. For example, if connection X is waiting for 8272 ** connection Y's transaction to be concluded, and similarly connection 8273 ** Y is waiting on connection X's transaction, then neither connection 8274 ** will proceed and the system may remain deadlocked indefinitely. 8275 ** 8276 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 8277 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 8278 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 8279 ** unlock-notify callback is registered. The system is said to be in 8280 ** a deadlocked state if connection A has registered for an unlock-notify 8281 ** callback on the conclusion of connection B's transaction, and connection 8282 ** B has itself registered for an unlock-notify callback when connection 8283 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 8284 ** the system is also considered to be deadlocked if connection B has 8285 ** registered for an unlock-notify callback on the conclusion of connection 8286 ** C's transaction, where connection C is waiting on connection A. ^Any 8287 ** number of levels of indirection are allowed. 8288 ** 8289 ** <b>The "DROP TABLE" Exception</b> 8290 ** 8291 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 8292 ** always appropriate to call sqlite3_unlock_notify(). There is however, 8293 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 8294 ** SQLite checks if there are any currently executing SELECT statements 8295 ** that belong to the same connection. If there are, SQLITE_LOCKED is 8296 ** returned. In this case there is no "blocking connection", so invoking 8297 ** sqlite3_unlock_notify() results in the unlock-notify callback being 8298 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 8299 ** or "DROP INDEX" query, an infinite loop might be the result. 8300 ** 8301 ** One way around this problem is to check the extended error code returned 8302 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 8303 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 8304 ** the special "DROP TABLE/INDEX" case, the extended error code is just 8305 ** SQLITE_LOCKED.)^ 8306 */ 8307 SQLITE_API int sqlite3_unlock_notify( 8308 sqlite3 *pBlocked, /* Waiting connection */ 8309 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 8310 void *pNotifyArg /* Argument to pass to xNotify */ 8311 ); 8312 8313 8314 /* 8315 ** CAPI3REF: String Comparison 8316 ** 8317 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 8318 ** and extensions to compare the contents of two buffers containing UTF-8 8319 ** strings in a case-independent fashion, using the same definition of "case 8320 ** independence" that SQLite uses internally when comparing identifiers. 8321 */ 8322 SQLITE_API int sqlite3_stricmp(const char *, const char *); 8323 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 8324 8325 /* 8326 ** CAPI3REF: String Globbing 8327 * 8328 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 8329 ** string X matches the [GLOB] pattern P. 8330 ** ^The definition of [GLOB] pattern matching used in 8331 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 8332 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 8333 ** is case sensitive. 8334 ** 8335 ** Note that this routine returns zero on a match and non-zero if the strings 8336 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8337 ** 8338 ** See also: [sqlite3_strlike()]. 8339 */ 8340 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 8341 8342 /* 8343 ** CAPI3REF: String LIKE Matching 8344 * 8345 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 8346 ** string X matches the [LIKE] pattern P with escape character E. 8347 ** ^The definition of [LIKE] pattern matching used in 8348 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 8349 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 8350 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 8351 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 8352 ** insensitive - equivalent upper and lower case ASCII characters match 8353 ** one another. 8354 ** 8355 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 8356 ** only ASCII characters are case folded. 8357 ** 8358 ** Note that this routine returns zero on a match and non-zero if the strings 8359 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8360 ** 8361 ** See also: [sqlite3_strglob()]. 8362 */ 8363 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 8364 8365 /* 8366 ** CAPI3REF: Error Logging Interface 8367 ** 8368 ** ^The [sqlite3_log()] interface writes a message into the [error log] 8369 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 8370 ** ^If logging is enabled, the zFormat string and subsequent arguments are 8371 ** used with [sqlite3_snprintf()] to generate the final output string. 8372 ** 8373 ** The sqlite3_log() interface is intended for use by extensions such as 8374 ** virtual tables, collating functions, and SQL functions. While there is 8375 ** nothing to prevent an application from calling sqlite3_log(), doing so 8376 ** is considered bad form. 8377 ** 8378 ** The zFormat string must not be NULL. 8379 ** 8380 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 8381 ** will not use dynamically allocated memory. The log message is stored in 8382 ** a fixed-length buffer on the stack. If the log message is longer than 8383 ** a few hundred characters, it will be truncated to the length of the 8384 ** buffer. 8385 */ 8386 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 8387 8388 /* 8389 ** CAPI3REF: Write-Ahead Log Commit Hook 8390 ** METHOD: sqlite3 8391 ** 8392 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 8393 ** is invoked each time data is committed to a database in wal mode. 8394 ** 8395 ** ^(The callback is invoked by SQLite after the commit has taken place and 8396 ** the associated write-lock on the database released)^, so the implementation 8397 ** may read, write or [checkpoint] the database as required. 8398 ** 8399 ** ^The first parameter passed to the callback function when it is invoked 8400 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 8401 ** registering the callback. ^The second is a copy of the database handle. 8402 ** ^The third parameter is the name of the database that was written to - 8403 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 8404 ** is the number of pages currently in the write-ahead log file, 8405 ** including those that were just committed. 8406 ** 8407 ** The callback function should normally return [SQLITE_OK]. ^If an error 8408 ** code is returned, that error will propagate back up through the 8409 ** SQLite code base to cause the statement that provoked the callback 8410 ** to report an error, though the commit will have still occurred. If the 8411 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 8412 ** that does not correspond to any valid SQLite error code, the results 8413 ** are undefined. 8414 ** 8415 ** A single database handle may have at most a single write-ahead log callback 8416 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 8417 ** previously registered write-ahead log callback. ^Note that the 8418 ** [sqlite3_wal_autocheckpoint()] interface and the 8419 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 8420 ** overwrite any prior [sqlite3_wal_hook()] settings. 8421 */ 8422 SQLITE_API void *sqlite3_wal_hook( 8423 sqlite3*, 8424 int(*)(void *,sqlite3*,const char*,int), 8425 void* 8426 ); 8427 8428 /* 8429 ** CAPI3REF: Configure an auto-checkpoint 8430 ** METHOD: sqlite3 8431 ** 8432 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 8433 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 8434 ** to automatically [checkpoint] 8435 ** after committing a transaction if there are N or 8436 ** more frames in the [write-ahead log] file. ^Passing zero or 8437 ** a negative value as the nFrame parameter disables automatic 8438 ** checkpoints entirely. 8439 ** 8440 ** ^The callback registered by this function replaces any existing callback 8441 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 8442 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 8443 ** configured by this function. 8444 ** 8445 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 8446 ** from SQL. 8447 ** 8448 ** ^Checkpoints initiated by this mechanism are 8449 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 8450 ** 8451 ** ^Every new [database connection] defaults to having the auto-checkpoint 8452 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 8453 ** pages. The use of this interface 8454 ** is only necessary if the default setting is found to be suboptimal 8455 ** for a particular application. 8456 */ 8457 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 8458 8459 /* 8460 ** CAPI3REF: Checkpoint a database 8461 ** METHOD: sqlite3 8462 ** 8463 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 8464 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 8465 ** 8466 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 8467 ** [write-ahead log] for database X on [database connection] D to be 8468 ** transferred into the database file and for the write-ahead log to 8469 ** be reset. See the [checkpointing] documentation for addition 8470 ** information. 8471 ** 8472 ** This interface used to be the only way to cause a checkpoint to 8473 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 8474 ** interface was added. This interface is retained for backwards 8475 ** compatibility and as a convenience for applications that need to manually 8476 ** start a callback but which do not need the full power (and corresponding 8477 ** complication) of [sqlite3_wal_checkpoint_v2()]. 8478 */ 8479 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 8480 8481 /* 8482 ** CAPI3REF: Checkpoint a database 8483 ** METHOD: sqlite3 8484 ** 8485 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 8486 ** operation on database X of [database connection] D in mode M. Status 8487 ** information is written back into integers pointed to by L and C.)^ 8488 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 8489 ** 8490 ** <dl> 8491 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 8492 ** ^Checkpoint as many frames as possible without waiting for any database 8493 ** readers or writers to finish, then sync the database file if all frames 8494 ** in the log were checkpointed. ^The [busy-handler callback] 8495 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 8496 ** ^On the other hand, passive mode might leave the checkpoint unfinished 8497 ** if there are concurrent readers or writers. 8498 ** 8499 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 8500 ** ^This mode blocks (it invokes the 8501 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 8502 ** database writer and all readers are reading from the most recent database 8503 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 8504 ** database file. ^This mode blocks new database writers while it is pending, 8505 ** but new database readers are allowed to continue unimpeded. 8506 ** 8507 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 8508 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 8509 ** that after checkpointing the log file it blocks (calls the 8510 ** [busy-handler callback]) 8511 ** until all readers are reading from the database file only. ^This ensures 8512 ** that the next writer will restart the log file from the beginning. 8513 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 8514 ** database writer attempts while it is pending, but does not impede readers. 8515 ** 8516 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 8517 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 8518 ** addition that it also truncates the log file to zero bytes just prior 8519 ** to a successful return. 8520 ** </dl> 8521 ** 8522 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 8523 ** the log file or to -1 if the checkpoint could not run because 8524 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 8525 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 8526 ** log file (including any that were already checkpointed before the function 8527 ** was called) or to -1 if the checkpoint could not run due to an error or 8528 ** because the database is not in WAL mode. ^Note that upon successful 8529 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 8530 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 8531 ** 8532 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 8533 ** any other process is running a checkpoint operation at the same time, the 8534 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 8535 ** busy-handler configured, it will not be invoked in this case. 8536 ** 8537 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 8538 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 8539 ** obtained immediately, and a busy-handler is configured, it is invoked and 8540 ** the writer lock retried until either the busy-handler returns 0 or the lock 8541 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 8542 ** database readers as described above. ^If the busy-handler returns 0 before 8543 ** the writer lock is obtained or while waiting for database readers, the 8544 ** checkpoint operation proceeds from that point in the same way as 8545 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 8546 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 8547 ** 8548 ** ^If parameter zDb is NULL or points to a zero length string, then the 8549 ** specified operation is attempted on all WAL databases [attached] to 8550 ** [database connection] db. In this case the 8551 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 8552 ** an SQLITE_BUSY error is encountered when processing one or more of the 8553 ** attached WAL databases, the operation is still attempted on any remaining 8554 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 8555 ** error occurs while processing an attached database, processing is abandoned 8556 ** and the error code is returned to the caller immediately. ^If no error 8557 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 8558 ** databases, SQLITE_OK is returned. 8559 ** 8560 ** ^If database zDb is the name of an attached database that is not in WAL 8561 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 8562 ** zDb is not NULL (or a zero length string) and is not the name of any 8563 ** attached database, SQLITE_ERROR is returned to the caller. 8564 ** 8565 ** ^Unless it returns SQLITE_MISUSE, 8566 ** the sqlite3_wal_checkpoint_v2() interface 8567 ** sets the error information that is queried by 8568 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 8569 ** 8570 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 8571 ** from SQL. 8572 */ 8573 SQLITE_API int sqlite3_wal_checkpoint_v2( 8574 sqlite3 *db, /* Database handle */ 8575 const char *zDb, /* Name of attached database (or NULL) */ 8576 int eMode, /* SQLITE_CHECKPOINT_* value */ 8577 int *pnLog, /* OUT: Size of WAL log in frames */ 8578 int *pnCkpt /* OUT: Total number of frames checkpointed */ 8579 ); 8580 8581 /* 8582 ** CAPI3REF: Checkpoint Mode Values 8583 ** KEYWORDS: {checkpoint mode} 8584 ** 8585 ** These constants define all valid values for the "checkpoint mode" passed 8586 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 8587 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 8588 ** meaning of each of these checkpoint modes. 8589 */ 8590 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 8591 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 8592 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 8593 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 8594 8595 /* 8596 ** CAPI3REF: Virtual Table Interface Configuration 8597 ** 8598 ** This function may be called by either the [xConnect] or [xCreate] method 8599 ** of a [virtual table] implementation to configure 8600 ** various facets of the virtual table interface. 8601 ** 8602 ** If this interface is invoked outside the context of an xConnect or 8603 ** xCreate virtual table method then the behavior is undefined. 8604 ** 8605 ** At present, there is only one option that may be configured using 8606 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 8607 ** may be added in the future. 8608 */ 8609 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 8610 8611 /* 8612 ** CAPI3REF: Virtual Table Configuration Options 8613 ** 8614 ** These macros define the various options to the 8615 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 8616 ** can use to customize and optimize their behavior. 8617 ** 8618 ** <dl> 8619 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 8620 ** <dd>Calls of the form 8621 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 8622 ** where X is an integer. If X is zero, then the [virtual table] whose 8623 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 8624 ** support constraints. In this configuration (which is the default) if 8625 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 8626 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 8627 ** specified as part of the users SQL statement, regardless of the actual 8628 ** ON CONFLICT mode specified. 8629 ** 8630 ** If X is non-zero, then the virtual table implementation guarantees 8631 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 8632 ** any modifications to internal or persistent data structures have been made. 8633 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 8634 ** is able to roll back a statement or database transaction, and abandon 8635 ** or continue processing the current SQL statement as appropriate. 8636 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 8637 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 8638 ** had been ABORT. 8639 ** 8640 ** Virtual table implementations that are required to handle OR REPLACE 8641 ** must do so within the [xUpdate] method. If a call to the 8642 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 8643 ** CONFLICT policy is REPLACE, the virtual table implementation should 8644 ** silently replace the appropriate rows within the xUpdate callback and 8645 ** return SQLITE_OK. Or, if this is not possible, it may return 8646 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 8647 ** constraint handling. 8648 ** </dl> 8649 */ 8650 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 8651 8652 /* 8653 ** CAPI3REF: Determine The Virtual Table Conflict Policy 8654 ** 8655 ** This function may only be called from within a call to the [xUpdate] method 8656 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 8657 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 8658 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 8659 ** of the SQL statement that triggered the call to the [xUpdate] method of the 8660 ** [virtual table]. 8661 */ 8662 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 8663 8664 /* 8665 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 8666 ** 8667 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 8668 ** method of a [virtual table], then it returns true if and only if the 8669 ** column is being fetched as part of an UPDATE operation during which the 8670 ** column value will not change. Applications might use this to substitute 8671 ** a return value that is less expensive to compute and that the corresponding 8672 ** [xUpdate] method understands as a "no-change" value. 8673 ** 8674 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 8675 ** the column is not changed by the UPDATE statement, then the xColumn 8676 ** method can optionally return without setting a result, without calling 8677 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 8678 ** In that case, [sqlite3_value_nochange(X)] will return true for the 8679 ** same column in the [xUpdate] method. 8680 */ 8681 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 8682 8683 /* 8684 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint 8685 ** 8686 ** This function may only be called from within a call to the [xBestIndex] 8687 ** method of a [virtual table]. 8688 ** 8689 ** The first argument must be the sqlite3_index_info object that is the 8690 ** first parameter to the xBestIndex() method. The second argument must be 8691 ** an index into the aConstraint[] array belonging to the sqlite3_index_info 8692 ** structure passed to xBestIndex. This function returns a pointer to a buffer 8693 ** containing the name of the collation sequence for the corresponding 8694 ** constraint. 8695 */ 8696 SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 8697 8698 /* 8699 ** CAPI3REF: Conflict resolution modes 8700 ** KEYWORDS: {conflict resolution mode} 8701 ** 8702 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 8703 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 8704 ** is for the SQL statement being evaluated. 8705 ** 8706 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 8707 ** return value from the [sqlite3_set_authorizer()] callback and that 8708 ** [SQLITE_ABORT] is also a [result code]. 8709 */ 8710 #define SQLITE_ROLLBACK 1 8711 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 8712 #define SQLITE_FAIL 3 8713 /* #define SQLITE_ABORT 4 // Also an error code */ 8714 #define SQLITE_REPLACE 5 8715 8716 /* 8717 ** CAPI3REF: Prepared Statement Scan Status Opcodes 8718 ** KEYWORDS: {scanstatus options} 8719 ** 8720 ** The following constants can be used for the T parameter to the 8721 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 8722 ** different metric for sqlite3_stmt_scanstatus() to return. 8723 ** 8724 ** When the value returned to V is a string, space to hold that string is 8725 ** managed by the prepared statement S and will be automatically freed when 8726 ** S is finalized. 8727 ** 8728 ** <dl> 8729 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 8730 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 8731 ** set to the total number of times that the X-th loop has run.</dd> 8732 ** 8733 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 8734 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 8735 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 8736 ** 8737 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 8738 ** <dd>^The "double" variable pointed to by the T parameter will be set to the 8739 ** query planner's estimate for the average number of rows output from each 8740 ** iteration of the X-th loop. If the query planner's estimates was accurate, 8741 ** then this value will approximate the quotient NVISIT/NLOOP and the 8742 ** product of this value for all prior loops with the same SELECTID will 8743 ** be the NLOOP value for the current loop. 8744 ** 8745 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8746 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 8747 ** to a zero-terminated UTF-8 string containing the name of the index or table 8748 ** used for the X-th loop. 8749 ** 8750 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 8751 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 8752 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 8753 ** description for the X-th loop. 8754 ** 8755 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 8756 ** <dd>^The "int" variable pointed to by the T parameter will be set to the 8757 ** "select-id" for the X-th loop. The select-id identifies which query or 8758 ** subquery the loop is part of. The main query has a select-id of zero. 8759 ** The select-id is the same value as is output in the first column 8760 ** of an [EXPLAIN QUERY PLAN] query. 8761 ** </dl> 8762 */ 8763 #define SQLITE_SCANSTAT_NLOOP 0 8764 #define SQLITE_SCANSTAT_NVISIT 1 8765 #define SQLITE_SCANSTAT_EST 2 8766 #define SQLITE_SCANSTAT_NAME 3 8767 #define SQLITE_SCANSTAT_EXPLAIN 4 8768 #define SQLITE_SCANSTAT_SELECTID 5 8769 8770 /* 8771 ** CAPI3REF: Prepared Statement Scan Status 8772 ** METHOD: sqlite3_stmt 8773 ** 8774 ** This interface returns information about the predicted and measured 8775 ** performance for pStmt. Advanced applications can use this 8776 ** interface to compare the predicted and the measured performance and 8777 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 8778 ** 8779 ** Since this interface is expected to be rarely used, it is only 8780 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 8781 ** compile-time option. 8782 ** 8783 ** The "iScanStatusOp" parameter determines which status information to return. 8784 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 8785 ** of this interface is undefined. 8786 ** ^The requested measurement is written into a variable pointed to by 8787 ** the "pOut" parameter. 8788 ** Parameter "idx" identifies the specific loop to retrieve statistics for. 8789 ** Loops are numbered starting from zero. ^If idx is out of range - less than 8790 ** zero or greater than or equal to the total number of loops used to implement 8791 ** the statement - a non-zero value is returned and the variable that pOut 8792 ** points to is unchanged. 8793 ** 8794 ** ^Statistics might not be available for all loops in all statements. ^In cases 8795 ** where there exist loops with no available statistics, this function behaves 8796 ** as if the loop did not exist - it returns non-zero and leave the variable 8797 ** that pOut points to unchanged. 8798 ** 8799 ** See also: [sqlite3_stmt_scanstatus_reset()] 8800 */ 8801 SQLITE_API int sqlite3_stmt_scanstatus( 8802 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 8803 int idx, /* Index of loop to report on */ 8804 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 8805 void *pOut /* Result written here */ 8806 ); 8807 8808 /* 8809 ** CAPI3REF: Zero Scan-Status Counters 8810 ** METHOD: sqlite3_stmt 8811 ** 8812 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 8813 ** 8814 ** This API is only available if the library is built with pre-processor 8815 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 8816 */ 8817 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 8818 8819 /* 8820 ** CAPI3REF: Flush caches to disk mid-transaction 8821 ** 8822 ** ^If a write-transaction is open on [database connection] D when the 8823 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 8824 ** pages in the pager-cache that are not currently in use are written out 8825 ** to disk. A dirty page may be in use if a database cursor created by an 8826 ** active SQL statement is reading from it, or if it is page 1 of a database 8827 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 8828 ** interface flushes caches for all schemas - "main", "temp", and 8829 ** any [attached] databases. 8830 ** 8831 ** ^If this function needs to obtain extra database locks before dirty pages 8832 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 8833 ** immediately and there is a busy-handler callback configured, it is invoked 8834 ** in the usual manner. ^If the required lock still cannot be obtained, then 8835 ** the database is skipped and an attempt made to flush any dirty pages 8836 ** belonging to the next (if any) database. ^If any databases are skipped 8837 ** because locks cannot be obtained, but no other error occurs, this 8838 ** function returns SQLITE_BUSY. 8839 ** 8840 ** ^If any other error occurs while flushing dirty pages to disk (for 8841 ** example an IO error or out-of-memory condition), then processing is 8842 ** abandoned and an SQLite [error code] is returned to the caller immediately. 8843 ** 8844 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 8845 ** 8846 ** ^This function does not set the database handle error code or message 8847 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 8848 */ 8849 SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 8850 8851 /* 8852 ** CAPI3REF: The pre-update hook. 8853 ** 8854 ** ^These interfaces are only available if SQLite is compiled using the 8855 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 8856 ** 8857 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 8858 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 8859 ** on a database table. 8860 ** ^At most one preupdate hook may be registered at a time on a single 8861 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 8862 ** the previous setting. 8863 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 8864 ** with a NULL pointer as the second parameter. 8865 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 8866 ** the first parameter to callbacks. 8867 ** 8868 ** ^The preupdate hook only fires for changes to real database tables; the 8869 ** preupdate hook is not invoked for changes to [virtual tables] or to 8870 ** system tables like sqlite_master or sqlite_stat1. 8871 ** 8872 ** ^The second parameter to the preupdate callback is a pointer to 8873 ** the [database connection] that registered the preupdate hook. 8874 ** ^The third parameter to the preupdate callback is one of the constants 8875 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 8876 ** kind of update operation that is about to occur. 8877 ** ^(The fourth parameter to the preupdate callback is the name of the 8878 ** database within the database connection that is being modified. This 8879 ** will be "main" for the main database or "temp" for TEMP tables or 8880 ** the name given after the AS keyword in the [ATTACH] statement for attached 8881 ** databases.)^ 8882 ** ^The fifth parameter to the preupdate callback is the name of the 8883 ** table that is being modified. 8884 ** 8885 ** For an UPDATE or DELETE operation on a [rowid table], the sixth 8886 ** parameter passed to the preupdate callback is the initial [rowid] of the 8887 ** row being modified or deleted. For an INSERT operation on a rowid table, 8888 ** or any operation on a WITHOUT ROWID table, the value of the sixth 8889 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the 8890 ** seventh parameter is the final rowid value of the row being inserted 8891 ** or updated. The value of the seventh parameter passed to the callback 8892 ** function is not defined for operations on WITHOUT ROWID tables, or for 8893 ** INSERT operations on rowid tables. 8894 ** 8895 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 8896 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 8897 ** provide additional information about a preupdate event. These routines 8898 ** may only be called from within a preupdate callback. Invoking any of 8899 ** these routines from outside of a preupdate callback or with a 8900 ** [database connection] pointer that is different from the one supplied 8901 ** to the preupdate callback results in undefined and probably undesirable 8902 ** behavior. 8903 ** 8904 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 8905 ** in the row that is being inserted, updated, or deleted. 8906 ** 8907 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 8908 ** a [protected sqlite3_value] that contains the value of the Nth column of 8909 ** the table row before it is updated. The N parameter must be between 0 8910 ** and one less than the number of columns or the behavior will be 8911 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 8912 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 8913 ** behavior is undefined. The [sqlite3_value] that P points to 8914 ** will be destroyed when the preupdate callback returns. 8915 ** 8916 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 8917 ** a [protected sqlite3_value] that contains the value of the Nth column of 8918 ** the table row after it is updated. The N parameter must be between 0 8919 ** and one less than the number of columns or the behavior will be 8920 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 8921 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 8922 ** behavior is undefined. The [sqlite3_value] that P points to 8923 ** will be destroyed when the preupdate callback returns. 8924 ** 8925 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 8926 ** callback was invoked as a result of a direct insert, update, or delete 8927 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 8928 ** triggers; or 2 for changes resulting from triggers called by top-level 8929 ** triggers; and so forth. 8930 ** 8931 ** See also: [sqlite3_update_hook()] 8932 */ 8933 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 8934 SQLITE_API void *sqlite3_preupdate_hook( 8935 sqlite3 *db, 8936 void(*xPreUpdate)( 8937 void *pCtx, /* Copy of third arg to preupdate_hook() */ 8938 sqlite3 *db, /* Database handle */ 8939 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 8940 char const *zDb, /* Database name */ 8941 char const *zName, /* Table name */ 8942 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 8943 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 8944 ), 8945 void* 8946 ); 8947 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 8948 SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 8949 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 8950 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 8951 #endif 8952 8953 /* 8954 ** CAPI3REF: Low-level system error code 8955 ** 8956 ** ^Attempt to return the underlying operating system error code or error 8957 ** number that caused the most recent I/O error or failure to open a file. 8958 ** The return value is OS-dependent. For example, on unix systems, after 8959 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 8960 ** called to get back the underlying "errno" that caused the problem, such 8961 ** as ENOSPC, EAUTH, EISDIR, and so forth. 8962 */ 8963 SQLITE_API int sqlite3_system_errno(sqlite3*); 8964 8965 /* 8966 ** CAPI3REF: Database Snapshot 8967 ** KEYWORDS: {snapshot} {sqlite3_snapshot} 8968 ** 8969 ** An instance of the snapshot object records the state of a [WAL mode] 8970 ** database for some specific point in history. 8971 ** 8972 ** In [WAL mode], multiple [database connections] that are open on the 8973 ** same database file can each be reading a different historical version 8974 ** of the database file. When a [database connection] begins a read 8975 ** transaction, that connection sees an unchanging copy of the database 8976 ** as it existed for the point in time when the transaction first started. 8977 ** Subsequent changes to the database from other connections are not seen 8978 ** by the reader until a new read transaction is started. 8979 ** 8980 ** The sqlite3_snapshot object records state information about an historical 8981 ** version of the database file so that it is possible to later open a new read 8982 ** transaction that sees that historical version of the database rather than 8983 ** the most recent version. 8984 */ 8985 typedef struct sqlite3_snapshot { 8986 unsigned char hidden[48]; 8987 } sqlite3_snapshot; 8988 8989 /* 8990 ** CAPI3REF: Record A Database Snapshot 8991 ** CONSTRUCTOR: sqlite3_snapshot 8992 ** 8993 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 8994 ** new [sqlite3_snapshot] object that records the current state of 8995 ** schema S in database connection D. ^On success, the 8996 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 8997 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 8998 ** If there is not already a read-transaction open on schema S when 8999 ** this function is called, one is opened automatically. 9000 ** 9001 ** The following must be true for this function to succeed. If any of 9002 ** the following statements are false when sqlite3_snapshot_get() is 9003 ** called, SQLITE_ERROR is returned. The final value of *P is undefined 9004 ** in this case. 9005 ** 9006 ** <ul> 9007 ** <li> The database handle must not be in [autocommit mode]. 9008 ** 9009 ** <li> Schema S of [database connection] D must be a [WAL mode] database. 9010 ** 9011 ** <li> There must not be a write transaction open on schema S of database 9012 ** connection D. 9013 ** 9014 ** <li> One or more transactions must have been written to the current wal 9015 ** file since it was created on disk (by any connection). This means 9016 ** that a snapshot cannot be taken on a wal mode database with no wal 9017 ** file immediately after it is first opened. At least one transaction 9018 ** must be written to it first. 9019 ** </ul> 9020 ** 9021 ** This function may also return SQLITE_NOMEM. If it is called with the 9022 ** database handle in autocommit mode but fails for some other reason, 9023 ** whether or not a read transaction is opened on schema S is undefined. 9024 ** 9025 ** The [sqlite3_snapshot] object returned from a successful call to 9026 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 9027 ** to avoid a memory leak. 9028 ** 9029 ** The [sqlite3_snapshot_get()] interface is only available when the 9030 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9031 */ 9032 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 9033 sqlite3 *db, 9034 const char *zSchema, 9035 sqlite3_snapshot **ppSnapshot 9036 ); 9037 9038 /* 9039 ** CAPI3REF: Start a read transaction on an historical snapshot 9040 ** METHOD: sqlite3_snapshot 9041 ** 9042 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 9043 ** transaction or upgrades an existing one for schema S of 9044 ** [database connection] D such that the read transaction refers to 9045 ** historical [snapshot] P, rather than the most recent change to the 9046 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 9047 ** on success or an appropriate [error code] if it fails. 9048 ** 9049 ** ^In order to succeed, the database connection must not be in 9050 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 9051 ** is already a read transaction open on schema S, then the database handle 9052 ** must have no active statements (SELECT statements that have been passed 9053 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 9054 ** SQLITE_ERROR is returned if either of these conditions is violated, or 9055 ** if schema S does not exist, or if the snapshot object is invalid. 9056 ** 9057 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified 9058 ** snapshot has been overwritten by a [checkpoint]. In this case 9059 ** SQLITE_ERROR_SNAPSHOT is returned. 9060 ** 9061 ** If there is already a read transaction open when this function is 9062 ** invoked, then the same read transaction remains open (on the same 9063 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 9064 ** is returned. If another error code - for example SQLITE_PROTOCOL or an 9065 ** SQLITE_IOERR error code - is returned, then the final state of the 9066 ** read transaction is undefined. If SQLITE_OK is returned, then the 9067 ** read transaction is now open on database snapshot P. 9068 ** 9069 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 9070 ** database connection D does not know that the database file for 9071 ** schema S is in [WAL mode]. A database connection might not know 9072 ** that the database file is in [WAL mode] if there has been no prior 9073 ** I/O on that database connection, or if the database entered [WAL mode] 9074 ** after the most recent I/O on the database connection.)^ 9075 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 9076 ** database connection in order to make it ready to use snapshots.) 9077 ** 9078 ** The [sqlite3_snapshot_open()] interface is only available when the 9079 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9080 */ 9081 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 9082 sqlite3 *db, 9083 const char *zSchema, 9084 sqlite3_snapshot *pSnapshot 9085 ); 9086 9087 /* 9088 ** CAPI3REF: Destroy a snapshot 9089 ** DESTRUCTOR: sqlite3_snapshot 9090 ** 9091 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 9092 ** The application must eventually free every [sqlite3_snapshot] object 9093 ** using this routine to avoid a memory leak. 9094 ** 9095 ** The [sqlite3_snapshot_free()] interface is only available when the 9096 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9097 */ 9098 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 9099 9100 /* 9101 ** CAPI3REF: Compare the ages of two snapshot handles. 9102 ** METHOD: sqlite3_snapshot 9103 ** 9104 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 9105 ** of two valid snapshot handles. 9106 ** 9107 ** If the two snapshot handles are not associated with the same database 9108 ** file, the result of the comparison is undefined. 9109 ** 9110 ** Additionally, the result of the comparison is only valid if both of the 9111 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 9112 ** last time the wal file was deleted. The wal file is deleted when the 9113 ** database is changed back to rollback mode or when the number of database 9114 ** clients drops to zero. If either snapshot handle was obtained before the 9115 ** wal file was last deleted, the value returned by this function 9116 ** is undefined. 9117 ** 9118 ** Otherwise, this API returns a negative value if P1 refers to an older 9119 ** snapshot than P2, zero if the two handles refer to the same database 9120 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 9121 ** 9122 ** This interface is only available if SQLite is compiled with the 9123 ** [SQLITE_ENABLE_SNAPSHOT] option. 9124 */ 9125 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 9126 sqlite3_snapshot *p1, 9127 sqlite3_snapshot *p2 9128 ); 9129 9130 /* 9131 ** CAPI3REF: Recover snapshots from a wal file 9132 ** METHOD: sqlite3_snapshot 9133 ** 9134 ** If a [WAL file] remains on disk after all database connections close 9135 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 9136 ** or because the last process to have the database opened exited without 9137 ** calling [sqlite3_close()]) and a new connection is subsequently opened 9138 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 9139 ** will only be able to open the last transaction added to the WAL file 9140 ** even though the WAL file contains other valid transactions. 9141 ** 9142 ** This function attempts to scan the WAL file associated with database zDb 9143 ** of database handle db and make all valid snapshots available to 9144 ** sqlite3_snapshot_open(). It is an error if there is already a read 9145 ** transaction open on the database, or if the database is not a WAL mode 9146 ** database. 9147 ** 9148 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 9149 ** 9150 ** This interface is only available if SQLite is compiled with the 9151 ** [SQLITE_ENABLE_SNAPSHOT] option. 9152 */ 9153 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 9154 9155 /* 9156 ** CAPI3REF: Serialize a database 9157 ** 9158 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 9159 ** that is a serialization of the S database on [database connection] D. 9160 ** If P is not a NULL pointer, then the size of the database in bytes 9161 ** is written into *P. 9162 ** 9163 ** For an ordinary on-disk database file, the serialization is just a 9164 ** copy of the disk file. For an in-memory database or a "TEMP" database, 9165 ** the serialization is the same sequence of bytes which would be written 9166 ** to disk if that database where backed up to disk. 9167 ** 9168 ** The usual case is that sqlite3_serialize() copies the serialization of 9169 ** the database into memory obtained from [sqlite3_malloc64()] and returns 9170 ** a pointer to that memory. The caller is responsible for freeing the 9171 ** returned value to avoid a memory leak. However, if the F argument 9172 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 9173 ** are made, and the sqlite3_serialize() function will return a pointer 9174 ** to the contiguous memory representation of the database that SQLite 9175 ** is currently using for that database, or NULL if the no such contiguous 9176 ** memory representation of the database exists. A contiguous memory 9177 ** representation of the database will usually only exist if there has 9178 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 9179 ** values of D and S. 9180 ** The size of the database is written into *P even if the 9181 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 9182 ** of the database exists. 9183 ** 9184 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 9185 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 9186 ** allocation error occurs. 9187 ** 9188 ** This interface is only available if SQLite is compiled with the 9189 ** [SQLITE_ENABLE_DESERIALIZE] option. 9190 */ 9191 SQLITE_API unsigned char *sqlite3_serialize( 9192 sqlite3 *db, /* The database connection */ 9193 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 9194 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 9195 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 9196 ); 9197 9198 /* 9199 ** CAPI3REF: Flags for sqlite3_serialize 9200 ** 9201 ** Zero or more of the following constants can be OR-ed together for 9202 ** the F argument to [sqlite3_serialize(D,S,P,F)]. 9203 ** 9204 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 9205 ** a pointer to contiguous in-memory database that it is currently using, 9206 ** without making a copy of the database. If SQLite is not currently using 9207 ** a contiguous in-memory database, then this option causes 9208 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 9209 ** using a contiguous in-memory database if it has been initialized by a 9210 ** prior call to [sqlite3_deserialize()]. 9211 */ 9212 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 9213 9214 /* 9215 ** CAPI3REF: Deserialize a database 9216 ** 9217 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 9218 ** [database connection] D to disconnect from database S and then 9219 ** reopen S as an in-memory database based on the serialization contained 9220 ** in P. The serialized database P is N bytes in size. M is the size of 9221 ** the buffer P, which might be larger than N. If M is larger than N, and 9222 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 9223 ** permitted to add content to the in-memory database as long as the total 9224 ** size does not exceed M bytes. 9225 ** 9226 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 9227 ** invoke sqlite3_free() on the serialization buffer when the database 9228 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 9229 ** SQLite will try to increase the buffer size using sqlite3_realloc64() 9230 ** if writes on the database cause it to grow larger than M bytes. 9231 ** 9232 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 9233 ** database is currently in a read transaction or is involved in a backup 9234 ** operation. 9235 ** 9236 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 9237 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 9238 ** [sqlite3_free()] is invoked on argument P prior to returning. 9239 ** 9240 ** This interface is only available if SQLite is compiled with the 9241 ** [SQLITE_ENABLE_DESERIALIZE] option. 9242 */ 9243 SQLITE_API int sqlite3_deserialize( 9244 sqlite3 *db, /* The database connection */ 9245 const char *zSchema, /* Which DB to reopen with the deserialization */ 9246 unsigned char *pData, /* The serialized database content */ 9247 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 9248 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 9249 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 9250 ); 9251 9252 /* 9253 ** CAPI3REF: Flags for sqlite3_deserialize() 9254 ** 9255 ** The following are allowed values for 6th argument (the F argument) to 9256 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 9257 ** 9258 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 9259 ** in the P argument is held in memory obtained from [sqlite3_malloc64()] 9260 ** and that SQLite should take ownership of this memory and automatically 9261 ** free it when it has finished using it. Without this flag, the caller 9262 ** is responsible for freeing any dynamically allocated memory. 9263 ** 9264 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 9265 ** grow the size of the database using calls to [sqlite3_realloc64()]. This 9266 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 9267 ** Without this flag, the deserialized database cannot increase in size beyond 9268 ** the number of bytes specified by the M parameter. 9269 ** 9270 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 9271 ** should be treated as read-only. 9272 */ 9273 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 9274 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 9275 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 9276 9277 /* 9278 ** Undo the hack that converts floating point types to integer for 9279 ** builds on processors without floating point support. 9280 */ 9281 #ifdef SQLITE_OMIT_FLOATING_POINT 9282 # undef double 9283 #endif 9284 9285 #ifdef __cplusplus 9286 } /* End of the 'extern "C"' block */ 9287 #endif 9288 #endif /* SQLITE3_H */ 9289 9290 /******** Begin file sqlite3rtree.h *********/ 9291 /* 9292 ** 2010 August 30 9293 ** 9294 ** The author disclaims copyright to this source code. In place of 9295 ** a legal notice, here is a blessing: 9296 ** 9297 ** May you do good and not evil. 9298 ** May you find forgiveness for yourself and forgive others. 9299 ** May you share freely, never taking more than you give. 9300 ** 9301 ************************************************************************* 9302 */ 9303 9304 #ifndef _SQLITE3RTREE_H_ 9305 #define _SQLITE3RTREE_H_ 9306 9307 9308 #ifdef __cplusplus 9309 extern "C" { 9310 #endif 9311 9312 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 9313 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 9314 9315 /* The double-precision datatype used by RTree depends on the 9316 ** SQLITE_RTREE_INT_ONLY compile-time option. 9317 */ 9318 #ifdef SQLITE_RTREE_INT_ONLY 9319 typedef sqlite3_int64 sqlite3_rtree_dbl; 9320 #else 9321 typedef double sqlite3_rtree_dbl; 9322 #endif 9323 9324 /* 9325 ** Register a geometry callback named zGeom that can be used as part of an 9326 ** R-Tree geometry query as follows: 9327 ** 9328 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 9329 */ 9330 SQLITE_API int sqlite3_rtree_geometry_callback( 9331 sqlite3 *db, 9332 const char *zGeom, 9333 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 9334 void *pContext 9335 ); 9336 9337 9338 /* 9339 ** A pointer to a structure of the following type is passed as the first 9340 ** argument to callbacks registered using rtree_geometry_callback(). 9341 */ 9342 struct sqlite3_rtree_geometry { 9343 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 9344 int nParam; /* Size of array aParam[] */ 9345 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 9346 void *pUser; /* Callback implementation user data */ 9347 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 9348 }; 9349 9350 /* 9351 ** Register a 2nd-generation geometry callback named zScore that can be 9352 ** used as part of an R-Tree geometry query as follows: 9353 ** 9354 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 9355 */ 9356 SQLITE_API int sqlite3_rtree_query_callback( 9357 sqlite3 *db, 9358 const char *zQueryFunc, 9359 int (*xQueryFunc)(sqlite3_rtree_query_info*), 9360 void *pContext, 9361 void (*xDestructor)(void*) 9362 ); 9363 9364 9365 /* 9366 ** A pointer to a structure of the following type is passed as the 9367 ** argument to scored geometry callback registered using 9368 ** sqlite3_rtree_query_callback(). 9369 ** 9370 ** Note that the first 5 fields of this structure are identical to 9371 ** sqlite3_rtree_geometry. This structure is a subclass of 9372 ** sqlite3_rtree_geometry. 9373 */ 9374 struct sqlite3_rtree_query_info { 9375 void *pContext; /* pContext from when function registered */ 9376 int nParam; /* Number of function parameters */ 9377 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 9378 void *pUser; /* callback can use this, if desired */ 9379 void (*xDelUser)(void*); /* function to free pUser */ 9380 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 9381 unsigned int *anQueue; /* Number of pending entries in the queue */ 9382 int nCoord; /* Number of coordinates */ 9383 int iLevel; /* Level of current node or entry */ 9384 int mxLevel; /* The largest iLevel value in the tree */ 9385 sqlite3_int64 iRowid; /* Rowid for current entry */ 9386 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 9387 int eParentWithin; /* Visibility of parent node */ 9388 int eWithin; /* OUT: Visiblity */ 9389 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 9390 /* The following fields are only available in 3.8.11 and later */ 9391 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 9392 }; 9393 9394 /* 9395 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 9396 */ 9397 #define NOT_WITHIN 0 /* Object completely outside of query region */ 9398 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 9399 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 9400 9401 9402 #ifdef __cplusplus 9403 } /* end of the 'extern "C"' block */ 9404 #endif 9405 9406 #endif /* ifndef _SQLITE3RTREE_H_ */ 9407 9408 /******** End of sqlite3rtree.h *********/ 9409 /******** Begin file sqlite3session.h *********/ 9410 9411 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 9412 #define __SQLITESESSION_H_ 1 9413 9414 /* 9415 ** Make sure we can call this stuff from C++. 9416 */ 9417 #ifdef __cplusplus 9418 extern "C" { 9419 #endif 9420 9421 9422 /* 9423 ** CAPI3REF: Session Object Handle 9424 ** 9425 ** An instance of this object is a [session] that can be used to 9426 ** record changes to a database. 9427 */ 9428 typedef struct sqlite3_session sqlite3_session; 9429 9430 /* 9431 ** CAPI3REF: Changeset Iterator Handle 9432 ** 9433 ** An instance of this object acts as a cursor for iterating 9434 ** over the elements of a [changeset] or [patchset]. 9435 */ 9436 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 9437 9438 /* 9439 ** CAPI3REF: Create A New Session Object 9440 ** CONSTRUCTOR: sqlite3_session 9441 ** 9442 ** Create a new session object attached to database handle db. If successful, 9443 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 9444 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 9445 ** error code (e.g. SQLITE_NOMEM) is returned. 9446 ** 9447 ** It is possible to create multiple session objects attached to a single 9448 ** database handle. 9449 ** 9450 ** Session objects created using this function should be deleted using the 9451 ** [sqlite3session_delete()] function before the database handle that they 9452 ** are attached to is itself closed. If the database handle is closed before 9453 ** the session object is deleted, then the results of calling any session 9454 ** module function, including [sqlite3session_delete()] on the session object 9455 ** are undefined. 9456 ** 9457 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 9458 ** is not possible for an application to register a pre-update hook on a 9459 ** database handle that has one or more session objects attached. Nor is 9460 ** it possible to create a session object attached to a database handle for 9461 ** which a pre-update hook is already defined. The results of attempting 9462 ** either of these things are undefined. 9463 ** 9464 ** The session object will be used to create changesets for tables in 9465 ** database zDb, where zDb is either "main", or "temp", or the name of an 9466 ** attached database. It is not an error if database zDb is not attached 9467 ** to the database when the session object is created. 9468 */ 9469 SQLITE_API int sqlite3session_create( 9470 sqlite3 *db, /* Database handle */ 9471 const char *zDb, /* Name of db (e.g. "main") */ 9472 sqlite3_session **ppSession /* OUT: New session object */ 9473 ); 9474 9475 /* 9476 ** CAPI3REF: Delete A Session Object 9477 ** DESTRUCTOR: sqlite3_session 9478 ** 9479 ** Delete a session object previously allocated using 9480 ** [sqlite3session_create()]. Once a session object has been deleted, the 9481 ** results of attempting to use pSession with any other session module 9482 ** function are undefined. 9483 ** 9484 ** Session objects must be deleted before the database handle to which they 9485 ** are attached is closed. Refer to the documentation for 9486 ** [sqlite3session_create()] for details. 9487 */ 9488 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 9489 9490 9491 /* 9492 ** CAPI3REF: Enable Or Disable A Session Object 9493 ** METHOD: sqlite3_session 9494 ** 9495 ** Enable or disable the recording of changes by a session object. When 9496 ** enabled, a session object records changes made to the database. When 9497 ** disabled - it does not. A newly created session object is enabled. 9498 ** Refer to the documentation for [sqlite3session_changeset()] for further 9499 ** details regarding how enabling and disabling a session object affects 9500 ** the eventual changesets. 9501 ** 9502 ** Passing zero to this function disables the session. Passing a value 9503 ** greater than zero enables it. Passing a value less than zero is a 9504 ** no-op, and may be used to query the current state of the session. 9505 ** 9506 ** The return value indicates the final state of the session object: 0 if 9507 ** the session is disabled, or 1 if it is enabled. 9508 */ 9509 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 9510 9511 /* 9512 ** CAPI3REF: Set Or Clear the Indirect Change Flag 9513 ** METHOD: sqlite3_session 9514 ** 9515 ** Each change recorded by a session object is marked as either direct or 9516 ** indirect. A change is marked as indirect if either: 9517 ** 9518 ** <ul> 9519 ** <li> The session object "indirect" flag is set when the change is 9520 ** made, or 9521 ** <li> The change is made by an SQL trigger or foreign key action 9522 ** instead of directly as a result of a users SQL statement. 9523 ** </ul> 9524 ** 9525 ** If a single row is affected by more than one operation within a session, 9526 ** then the change is considered indirect if all operations meet the criteria 9527 ** for an indirect change above, or direct otherwise. 9528 ** 9529 ** This function is used to set, clear or query the session object indirect 9530 ** flag. If the second argument passed to this function is zero, then the 9531 ** indirect flag is cleared. If it is greater than zero, the indirect flag 9532 ** is set. Passing a value less than zero does not modify the current value 9533 ** of the indirect flag, and may be used to query the current state of the 9534 ** indirect flag for the specified session object. 9535 ** 9536 ** The return value indicates the final state of the indirect flag: 0 if 9537 ** it is clear, or 1 if it is set. 9538 */ 9539 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 9540 9541 /* 9542 ** CAPI3REF: Attach A Table To A Session Object 9543 ** METHOD: sqlite3_session 9544 ** 9545 ** If argument zTab is not NULL, then it is the name of a table to attach 9546 ** to the session object passed as the first argument. All subsequent changes 9547 ** made to the table while the session object is enabled will be recorded. See 9548 ** documentation for [sqlite3session_changeset()] for further details. 9549 ** 9550 ** Or, if argument zTab is NULL, then changes are recorded for all tables 9551 ** in the database. If additional tables are added to the database (by 9552 ** executing "CREATE TABLE" statements) after this call is made, changes for 9553 ** the new tables are also recorded. 9554 ** 9555 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 9556 ** defined as part of their CREATE TABLE statement. It does not matter if the 9557 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 9558 ** KEY may consist of a single column, or may be a composite key. 9559 ** 9560 ** It is not an error if the named table does not exist in the database. Nor 9561 ** is it an error if the named table does not have a PRIMARY KEY. However, 9562 ** no changes will be recorded in either of these scenarios. 9563 ** 9564 ** Changes are not recorded for individual rows that have NULL values stored 9565 ** in one or more of their PRIMARY KEY columns. 9566 ** 9567 ** SQLITE_OK is returned if the call completes without error. Or, if an error 9568 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 9569 ** 9570 ** <h3>Special sqlite_stat1 Handling</h3> 9571 ** 9572 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 9573 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 9574 ** <pre> 9575 ** CREATE TABLE sqlite_stat1(tbl,idx,stat) 9576 ** </pre> 9577 ** 9578 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 9579 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 9580 ** are recorded for rows for which (idx IS NULL) is true. However, for such 9581 ** rows a zero-length blob (SQL value X'') is stored in the changeset or 9582 ** patchset instead of a NULL value. This allows such changesets to be 9583 ** manipulated by legacy implementations of sqlite3changeset_invert(), 9584 ** concat() and similar. 9585 ** 9586 ** The sqlite3changeset_apply() function automatically converts the 9587 ** zero-length blob back to a NULL value when updating the sqlite_stat1 9588 ** table. However, if the application calls sqlite3changeset_new(), 9589 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 9590 ** iterator directly (including on a changeset iterator passed to a 9591 ** conflict-handler callback) then the X'' value is returned. The application 9592 ** must translate X'' to NULL itself if required. 9593 ** 9594 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture 9595 ** changes made to the sqlite_stat1 table. Legacy versions of the 9596 ** sqlite3changeset_apply() function silently ignore any modifications to the 9597 ** sqlite_stat1 table that are part of a changeset or patchset. 9598 */ 9599 SQLITE_API int sqlite3session_attach( 9600 sqlite3_session *pSession, /* Session object */ 9601 const char *zTab /* Table name */ 9602 ); 9603 9604 /* 9605 ** CAPI3REF: Set a table filter on a Session Object. 9606 ** METHOD: sqlite3_session 9607 ** 9608 ** The second argument (xFilter) is the "filter callback". For changes to rows 9609 ** in tables that are not attached to the Session object, the filter is called 9610 ** to determine whether changes to the table's rows should be tracked or not. 9611 ** If xFilter returns 0, changes is not tracked. Note that once a table is 9612 ** attached, xFilter will not be called again. 9613 */ 9614 SQLITE_API void sqlite3session_table_filter( 9615 sqlite3_session *pSession, /* Session object */ 9616 int(*xFilter)( 9617 void *pCtx, /* Copy of third arg to _filter_table() */ 9618 const char *zTab /* Table name */ 9619 ), 9620 void *pCtx /* First argument passed to xFilter */ 9621 ); 9622 9623 /* 9624 ** CAPI3REF: Generate A Changeset From A Session Object 9625 ** METHOD: sqlite3_session 9626 ** 9627 ** Obtain a changeset containing changes to the tables attached to the 9628 ** session object passed as the first argument. If successful, 9629 ** set *ppChangeset to point to a buffer containing the changeset 9630 ** and *pnChangeset to the size of the changeset in bytes before returning 9631 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 9632 ** zero and return an SQLite error code. 9633 ** 9634 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 9635 ** each representing a change to a single row of an attached table. An INSERT 9636 ** change contains the values of each field of a new database row. A DELETE 9637 ** contains the original values of each field of a deleted database row. An 9638 ** UPDATE change contains the original values of each field of an updated 9639 ** database row along with the updated values for each updated non-primary-key 9640 ** column. It is not possible for an UPDATE change to represent a change that 9641 ** modifies the values of primary key columns. If such a change is made, it 9642 ** is represented in a changeset as a DELETE followed by an INSERT. 9643 ** 9644 ** Changes are not recorded for rows that have NULL values stored in one or 9645 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 9646 ** no corresponding change is present in the changesets returned by this 9647 ** function. If an existing row with one or more NULL values stored in 9648 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 9649 ** only an INSERT is appears in the changeset. Similarly, if an existing row 9650 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 9651 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 9652 ** DELETE change only. 9653 ** 9654 ** The contents of a changeset may be traversed using an iterator created 9655 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 9656 ** a database with a compatible schema using the [sqlite3changeset_apply()] 9657 ** API. 9658 ** 9659 ** Within a changeset generated by this function, all changes related to a 9660 ** single table are grouped together. In other words, when iterating through 9661 ** a changeset or when applying a changeset to a database, all changes related 9662 ** to a single table are processed before moving on to the next table. Tables 9663 ** are sorted in the same order in which they were attached (or auto-attached) 9664 ** to the sqlite3_session object. The order in which the changes related to 9665 ** a single table are stored is undefined. 9666 ** 9667 ** Following a successful call to this function, it is the responsibility of 9668 ** the caller to eventually free the buffer that *ppChangeset points to using 9669 ** [sqlite3_free()]. 9670 ** 9671 ** <h3>Changeset Generation</h3> 9672 ** 9673 ** Once a table has been attached to a session object, the session object 9674 ** records the primary key values of all new rows inserted into the table. 9675 ** It also records the original primary key and other column values of any 9676 ** deleted or updated rows. For each unique primary key value, data is only 9677 ** recorded once - the first time a row with said primary key is inserted, 9678 ** updated or deleted in the lifetime of the session. 9679 ** 9680 ** There is one exception to the previous paragraph: when a row is inserted, 9681 ** updated or deleted, if one or more of its primary key columns contain a 9682 ** NULL value, no record of the change is made. 9683 ** 9684 ** The session object therefore accumulates two types of records - those 9685 ** that consist of primary key values only (created when the user inserts 9686 ** a new record) and those that consist of the primary key values and the 9687 ** original values of other table columns (created when the users deletes 9688 ** or updates a record). 9689 ** 9690 ** When this function is called, the requested changeset is created using 9691 ** both the accumulated records and the current contents of the database 9692 ** file. Specifically: 9693 ** 9694 ** <ul> 9695 ** <li> For each record generated by an insert, the database is queried 9696 ** for a row with a matching primary key. If one is found, an INSERT 9697 ** change is added to the changeset. If no such row is found, no change 9698 ** is added to the changeset. 9699 ** 9700 ** <li> For each record generated by an update or delete, the database is 9701 ** queried for a row with a matching primary key. If such a row is 9702 ** found and one or more of the non-primary key fields have been 9703 ** modified from their original values, an UPDATE change is added to 9704 ** the changeset. Or, if no such row is found in the table, a DELETE 9705 ** change is added to the changeset. If there is a row with a matching 9706 ** primary key in the database, but all fields contain their original 9707 ** values, no change is added to the changeset. 9708 ** </ul> 9709 ** 9710 ** This means, amongst other things, that if a row is inserted and then later 9711 ** deleted while a session object is active, neither the insert nor the delete 9712 ** will be present in the changeset. Or if a row is deleted and then later a 9713 ** row with the same primary key values inserted while a session object is 9714 ** active, the resulting changeset will contain an UPDATE change instead of 9715 ** a DELETE and an INSERT. 9716 ** 9717 ** When a session object is disabled (see the [sqlite3session_enable()] API), 9718 ** it does not accumulate records when rows are inserted, updated or deleted. 9719 ** This may appear to have some counter-intuitive effects if a single row 9720 ** is written to more than once during a session. For example, if a row 9721 ** is inserted while a session object is enabled, then later deleted while 9722 ** the same session object is disabled, no INSERT record will appear in the 9723 ** changeset, even though the delete took place while the session was disabled. 9724 ** Or, if one field of a row is updated while a session is disabled, and 9725 ** another field of the same row is updated while the session is enabled, the 9726 ** resulting changeset will contain an UPDATE change that updates both fields. 9727 */ 9728 SQLITE_API int sqlite3session_changeset( 9729 sqlite3_session *pSession, /* Session object */ 9730 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 9731 void **ppChangeset /* OUT: Buffer containing changeset */ 9732 ); 9733 9734 /* 9735 ** CAPI3REF: Load The Difference Between Tables Into A Session 9736 ** METHOD: sqlite3_session 9737 ** 9738 ** If it is not already attached to the session object passed as the first 9739 ** argument, this function attaches table zTbl in the same manner as the 9740 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 9741 ** does not have a primary key, this function is a no-op (but does not return 9742 ** an error). 9743 ** 9744 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 9745 ** attached to the same database handle as the session object that contains 9746 ** a table compatible with the table attached to the session by this function. 9747 ** A table is considered compatible if it: 9748 ** 9749 ** <ul> 9750 ** <li> Has the same name, 9751 ** <li> Has the same set of columns declared in the same order, and 9752 ** <li> Has the same PRIMARY KEY definition. 9753 ** </ul> 9754 ** 9755 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 9756 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 9757 ** but no changes are added to the session object. As with other session 9758 ** APIs, tables without PRIMARY KEYs are simply ignored. 9759 ** 9760 ** This function adds a set of changes to the session object that could be 9761 ** used to update the table in database zFrom (call this the "from-table") 9762 ** so that its content is the same as the table attached to the session 9763 ** object (call this the "to-table"). Specifically: 9764 ** 9765 ** <ul> 9766 ** <li> For each row (primary key) that exists in the to-table but not in 9767 ** the from-table, an INSERT record is added to the session object. 9768 ** 9769 ** <li> For each row (primary key) that exists in the to-table but not in 9770 ** the from-table, a DELETE record is added to the session object. 9771 ** 9772 ** <li> For each row (primary key) that exists in both tables, but features 9773 ** different non-PK values in each, an UPDATE record is added to the 9774 ** session. 9775 ** </ul> 9776 ** 9777 ** To clarify, if this function is called and then a changeset constructed 9778 ** using [sqlite3session_changeset()], then after applying that changeset to 9779 ** database zFrom the contents of the two compatible tables would be 9780 ** identical. 9781 ** 9782 ** It an error if database zFrom does not exist or does not contain the 9783 ** required compatible table. 9784 ** 9785 ** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite 9786 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 9787 ** may be set to point to a buffer containing an English language error 9788 ** message. It is the responsibility of the caller to free this buffer using 9789 ** sqlite3_free(). 9790 */ 9791 SQLITE_API int sqlite3session_diff( 9792 sqlite3_session *pSession, 9793 const char *zFromDb, 9794 const char *zTbl, 9795 char **pzErrMsg 9796 ); 9797 9798 9799 /* 9800 ** CAPI3REF: Generate A Patchset From A Session Object 9801 ** METHOD: sqlite3_session 9802 ** 9803 ** The differences between a patchset and a changeset are that: 9804 ** 9805 ** <ul> 9806 ** <li> DELETE records consist of the primary key fields only. The 9807 ** original values of other fields are omitted. 9808 ** <li> The original values of any modified fields are omitted from 9809 ** UPDATE records. 9810 ** </ul> 9811 ** 9812 ** A patchset blob may be used with up to date versions of all 9813 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 9814 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 9815 ** attempting to use a patchset blob with old versions of the 9816 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 9817 ** 9818 ** Because the non-primary key "old.*" fields are omitted, no 9819 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 9820 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 9821 ** in the same way as for changesets. 9822 ** 9823 ** Changes within a patchset are ordered in the same way as for changesets 9824 ** generated by the sqlite3session_changeset() function (i.e. all changes for 9825 ** a single table are grouped together, tables appear in the order in which 9826 ** they were attached to the session object). 9827 */ 9828 SQLITE_API int sqlite3session_patchset( 9829 sqlite3_session *pSession, /* Session object */ 9830 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 9831 void **ppPatchset /* OUT: Buffer containing patchset */ 9832 ); 9833 9834 /* 9835 ** CAPI3REF: Test if a changeset has recorded any changes. 9836 ** 9837 ** Return non-zero if no changes to attached tables have been recorded by 9838 ** the session object passed as the first argument. Otherwise, if one or 9839 ** more changes have been recorded, return zero. 9840 ** 9841 ** Even if this function returns zero, it is possible that calling 9842 ** [sqlite3session_changeset()] on the session handle may still return a 9843 ** changeset that contains no changes. This can happen when a row in 9844 ** an attached table is modified and then later on the original values 9845 ** are restored. However, if this function returns non-zero, then it is 9846 ** guaranteed that a call to sqlite3session_changeset() will return a 9847 ** changeset containing zero changes. 9848 */ 9849 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 9850 9851 /* 9852 ** CAPI3REF: Create An Iterator To Traverse A Changeset 9853 ** CONSTRUCTOR: sqlite3_changeset_iter 9854 ** 9855 ** Create an iterator used to iterate through the contents of a changeset. 9856 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 9857 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 9858 ** SQLite error code is returned. 9859 ** 9860 ** The following functions can be used to advance and query a changeset 9861 ** iterator created by this function: 9862 ** 9863 ** <ul> 9864 ** <li> [sqlite3changeset_next()] 9865 ** <li> [sqlite3changeset_op()] 9866 ** <li> [sqlite3changeset_new()] 9867 ** <li> [sqlite3changeset_old()] 9868 ** </ul> 9869 ** 9870 ** It is the responsibility of the caller to eventually destroy the iterator 9871 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 9872 ** changeset (pChangeset) must remain valid until after the iterator is 9873 ** destroyed. 9874 ** 9875 ** Assuming the changeset blob was created by one of the 9876 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 9877 ** [sqlite3changeset_invert()] functions, all changes within the changeset 9878 ** that apply to a single table are grouped together. This means that when 9879 ** an application iterates through a changeset using an iterator created by 9880 ** this function, all changes that relate to a single table are visited 9881 ** consecutively. There is no chance that the iterator will visit a change 9882 ** the applies to table X, then one for table Y, and then later on visit 9883 ** another change for table X. 9884 */ 9885 SQLITE_API int sqlite3changeset_start( 9886 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 9887 int nChangeset, /* Size of changeset blob in bytes */ 9888 void *pChangeset /* Pointer to blob containing changeset */ 9889 ); 9890 9891 9892 /* 9893 ** CAPI3REF: Advance A Changeset Iterator 9894 ** METHOD: sqlite3_changeset_iter 9895 ** 9896 ** This function may only be used with iterators created by function 9897 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 9898 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 9899 ** is returned and the call has no effect. 9900 ** 9901 ** Immediately after an iterator is created by sqlite3changeset_start(), it 9902 ** does not point to any change in the changeset. Assuming the changeset 9903 ** is not empty, the first call to this function advances the iterator to 9904 ** point to the first change in the changeset. Each subsequent call advances 9905 ** the iterator to point to the next change in the changeset (if any). If 9906 ** no error occurs and the iterator points to a valid change after a call 9907 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 9908 ** Otherwise, if all changes in the changeset have already been visited, 9909 ** SQLITE_DONE is returned. 9910 ** 9911 ** If an error occurs, an SQLite error code is returned. Possible error 9912 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 9913 ** SQLITE_NOMEM. 9914 */ 9915 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 9916 9917 /* 9918 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 9919 ** METHOD: sqlite3_changeset_iter 9920 ** 9921 ** The pIter argument passed to this function may either be an iterator 9922 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9923 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 9924 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 9925 ** is not the case, this function returns [SQLITE_MISUSE]. 9926 ** 9927 ** If argument pzTab is not NULL, then *pzTab is set to point to a 9928 ** nul-terminated utf-8 encoded string containing the name of the table 9929 ** affected by the current change. The buffer remains valid until either 9930 ** sqlite3changeset_next() is called on the iterator or until the 9931 ** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 9932 ** set to the number of columns in the table affected by the change. If 9933 ** pbIncorrect is not NULL, then *pbIndirect is set to true (1) if the change 9934 ** is an indirect change, or false (0) otherwise. See the documentation for 9935 ** [sqlite3session_indirect()] for a description of direct and indirect 9936 ** changes. Finally, if pOp is not NULL, then *pOp is set to one of 9937 ** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 9938 ** type of change that the iterator currently points to. 9939 ** 9940 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 9941 ** SQLite error code is returned. The values of the output variables may not 9942 ** be trusted in this case. 9943 */ 9944 SQLITE_API int sqlite3changeset_op( 9945 sqlite3_changeset_iter *pIter, /* Iterator object */ 9946 const char **pzTab, /* OUT: Pointer to table name */ 9947 int *pnCol, /* OUT: Number of columns in table */ 9948 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 9949 int *pbIndirect /* OUT: True for an 'indirect' change */ 9950 ); 9951 9952 /* 9953 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 9954 ** METHOD: sqlite3_changeset_iter 9955 ** 9956 ** For each modified table, a changeset includes the following: 9957 ** 9958 ** <ul> 9959 ** <li> The number of columns in the table, and 9960 ** <li> Which of those columns make up the tables PRIMARY KEY. 9961 ** </ul> 9962 ** 9963 ** This function is used to find which columns comprise the PRIMARY KEY of 9964 ** the table modified by the change that iterator pIter currently points to. 9965 ** If successful, *pabPK is set to point to an array of nCol entries, where 9966 ** nCol is the number of columns in the table. Elements of *pabPK are set to 9967 ** 0x01 if the corresponding column is part of the tables primary key, or 9968 ** 0x00 if it is not. 9969 ** 9970 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 9971 ** in the table. 9972 ** 9973 ** If this function is called when the iterator does not point to a valid 9974 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 9975 ** SQLITE_OK is returned and the output variables populated as described 9976 ** above. 9977 */ 9978 SQLITE_API int sqlite3changeset_pk( 9979 sqlite3_changeset_iter *pIter, /* Iterator object */ 9980 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 9981 int *pnCol /* OUT: Number of entries in output array */ 9982 ); 9983 9984 /* 9985 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 9986 ** METHOD: sqlite3_changeset_iter 9987 ** 9988 ** The pIter argument passed to this function may either be an iterator 9989 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9990 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 9991 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 9992 ** Furthermore, it may only be called if the type of change that the iterator 9993 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 9994 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 9995 ** 9996 ** Argument iVal must be greater than or equal to 0, and less than the number 9997 ** of columns in the table affected by the current change. Otherwise, 9998 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9999 ** 10000 ** If successful, this function sets *ppValue to point to a protected 10001 ** sqlite3_value object containing the iVal'th value from the vector of 10002 ** original row values stored as part of the UPDATE or DELETE change and 10003 ** returns SQLITE_OK. The name of the function comes from the fact that this 10004 ** is similar to the "old.*" columns available to update or delete triggers. 10005 ** 10006 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10007 ** is returned and *ppValue is set to NULL. 10008 */ 10009 SQLITE_API int sqlite3changeset_old( 10010 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10011 int iVal, /* Column number */ 10012 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 10013 ); 10014 10015 /* 10016 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 10017 ** METHOD: sqlite3_changeset_iter 10018 ** 10019 ** The pIter argument passed to this function may either be an iterator 10020 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10021 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10022 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10023 ** Furthermore, it may only be called if the type of change that the iterator 10024 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 10025 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10026 ** 10027 ** Argument iVal must be greater than or equal to 0, and less than the number 10028 ** of columns in the table affected by the current change. Otherwise, 10029 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10030 ** 10031 ** If successful, this function sets *ppValue to point to a protected 10032 ** sqlite3_value object containing the iVal'th value from the vector of 10033 ** new row values stored as part of the UPDATE or INSERT change and 10034 ** returns SQLITE_OK. If the change is an UPDATE and does not include 10035 ** a new value for the requested column, *ppValue is set to NULL and 10036 ** SQLITE_OK returned. The name of the function comes from the fact that 10037 ** this is similar to the "new.*" columns available to update or delete 10038 ** triggers. 10039 ** 10040 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10041 ** is returned and *ppValue is set to NULL. 10042 */ 10043 SQLITE_API int sqlite3changeset_new( 10044 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10045 int iVal, /* Column number */ 10046 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 10047 ); 10048 10049 /* 10050 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 10051 ** METHOD: sqlite3_changeset_iter 10052 ** 10053 ** This function should only be used with iterator objects passed to a 10054 ** conflict-handler callback by [sqlite3changeset_apply()] with either 10055 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 10056 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 10057 ** is set to NULL. 10058 ** 10059 ** Argument iVal must be greater than or equal to 0, and less than the number 10060 ** of columns in the table affected by the current change. Otherwise, 10061 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10062 ** 10063 ** If successful, this function sets *ppValue to point to a protected 10064 ** sqlite3_value object containing the iVal'th value from the 10065 ** "conflicting row" associated with the current conflict-handler callback 10066 ** and returns SQLITE_OK. 10067 ** 10068 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10069 ** is returned and *ppValue is set to NULL. 10070 */ 10071 SQLITE_API int sqlite3changeset_conflict( 10072 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10073 int iVal, /* Column number */ 10074 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 10075 ); 10076 10077 /* 10078 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 10079 ** METHOD: sqlite3_changeset_iter 10080 ** 10081 ** This function may only be called with an iterator passed to an 10082 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 10083 ** it sets the output variable to the total number of known foreign key 10084 ** violations in the destination database and returns SQLITE_OK. 10085 ** 10086 ** In all other cases this function returns SQLITE_MISUSE. 10087 */ 10088 SQLITE_API int sqlite3changeset_fk_conflicts( 10089 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10090 int *pnOut /* OUT: Number of FK violations */ 10091 ); 10092 10093 10094 /* 10095 ** CAPI3REF: Finalize A Changeset Iterator 10096 ** METHOD: sqlite3_changeset_iter 10097 ** 10098 ** This function is used to finalize an iterator allocated with 10099 ** [sqlite3changeset_start()]. 10100 ** 10101 ** This function should only be called on iterators created using the 10102 ** [sqlite3changeset_start()] function. If an application calls this 10103 ** function with an iterator passed to a conflict-handler by 10104 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 10105 ** call has no effect. 10106 ** 10107 ** If an error was encountered within a call to an sqlite3changeset_xxx() 10108 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 10109 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 10110 ** to that error is returned by this function. Otherwise, SQLITE_OK is 10111 ** returned. This is to allow the following pattern (pseudo-code): 10112 ** 10113 ** <pre> 10114 ** sqlite3changeset_start(); 10115 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 10116 ** // Do something with change. 10117 ** } 10118 ** rc = sqlite3changeset_finalize(); 10119 ** if( rc!=SQLITE_OK ){ 10120 ** // An error has occurred 10121 ** } 10122 ** </pre> 10123 */ 10124 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 10125 10126 /* 10127 ** CAPI3REF: Invert A Changeset 10128 ** 10129 ** This function is used to "invert" a changeset object. Applying an inverted 10130 ** changeset to a database reverses the effects of applying the uninverted 10131 ** changeset. Specifically: 10132 ** 10133 ** <ul> 10134 ** <li> Each DELETE change is changed to an INSERT, and 10135 ** <li> Each INSERT change is changed to a DELETE, and 10136 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 10137 ** </ul> 10138 ** 10139 ** This function does not change the order in which changes appear within 10140 ** the changeset. It merely reverses the sense of each individual change. 10141 ** 10142 ** If successful, a pointer to a buffer containing the inverted changeset 10143 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 10144 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 10145 ** zeroed and an SQLite error code returned. 10146 ** 10147 ** It is the responsibility of the caller to eventually call sqlite3_free() 10148 ** on the *ppOut pointer to free the buffer allocation following a successful 10149 ** call to this function. 10150 ** 10151 ** WARNING/TODO: This function currently assumes that the input is a valid 10152 ** changeset. If it is not, the results are undefined. 10153 */ 10154 SQLITE_API int sqlite3changeset_invert( 10155 int nIn, const void *pIn, /* Input changeset */ 10156 int *pnOut, void **ppOut /* OUT: Inverse of input */ 10157 ); 10158 10159 /* 10160 ** CAPI3REF: Concatenate Two Changeset Objects 10161 ** 10162 ** This function is used to concatenate two changesets, A and B, into a 10163 ** single changeset. The result is a changeset equivalent to applying 10164 ** changeset A followed by changeset B. 10165 ** 10166 ** This function combines the two input changesets using an 10167 ** sqlite3_changegroup object. Calling it produces similar results as the 10168 ** following code fragment: 10169 ** 10170 ** <pre> 10171 ** sqlite3_changegroup *pGrp; 10172 ** rc = sqlite3_changegroup_new(&pGrp); 10173 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 10174 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 10175 ** if( rc==SQLITE_OK ){ 10176 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 10177 ** }else{ 10178 ** *ppOut = 0; 10179 ** *pnOut = 0; 10180 ** } 10181 ** </pre> 10182 ** 10183 ** Refer to the sqlite3_changegroup documentation below for details. 10184 */ 10185 SQLITE_API int sqlite3changeset_concat( 10186 int nA, /* Number of bytes in buffer pA */ 10187 void *pA, /* Pointer to buffer containing changeset A */ 10188 int nB, /* Number of bytes in buffer pB */ 10189 void *pB, /* Pointer to buffer containing changeset B */ 10190 int *pnOut, /* OUT: Number of bytes in output changeset */ 10191 void **ppOut /* OUT: Buffer containing output changeset */ 10192 ); 10193 10194 10195 /* 10196 ** CAPI3REF: Changegroup Handle 10197 ** 10198 ** A changegroup is an object used to combine two or more 10199 ** [changesets] or [patchsets] 10200 */ 10201 typedef struct sqlite3_changegroup sqlite3_changegroup; 10202 10203 /* 10204 ** CAPI3REF: Create A New Changegroup Object 10205 ** CONSTRUCTOR: sqlite3_changegroup 10206 ** 10207 ** An sqlite3_changegroup object is used to combine two or more changesets 10208 ** (or patchsets) into a single changeset (or patchset). A single changegroup 10209 ** object may combine changesets or patchsets, but not both. The output is 10210 ** always in the same format as the input. 10211 ** 10212 ** If successful, this function returns SQLITE_OK and populates (*pp) with 10213 ** a pointer to a new sqlite3_changegroup object before returning. The caller 10214 ** should eventually free the returned object using a call to 10215 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 10216 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 10217 ** 10218 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 10219 ** 10220 ** <ul> 10221 ** <li> It is created using a call to sqlite3changegroup_new(). 10222 ** 10223 ** <li> Zero or more changesets (or patchsets) are added to the object 10224 ** by calling sqlite3changegroup_add(). 10225 ** 10226 ** <li> The result of combining all input changesets together is obtained 10227 ** by the application via a call to sqlite3changegroup_output(). 10228 ** 10229 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 10230 ** </ul> 10231 ** 10232 ** Any number of calls to add() and output() may be made between the calls to 10233 ** new() and delete(), and in any order. 10234 ** 10235 ** As well as the regular sqlite3changegroup_add() and 10236 ** sqlite3changegroup_output() functions, also available are the streaming 10237 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 10238 */ 10239 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 10240 10241 /* 10242 ** CAPI3REF: Add A Changeset To A Changegroup 10243 ** METHOD: sqlite3_changegroup 10244 ** 10245 ** Add all changes within the changeset (or patchset) in buffer pData (size 10246 ** nData bytes) to the changegroup. 10247 ** 10248 ** If the buffer contains a patchset, then all prior calls to this function 10249 ** on the same changegroup object must also have specified patchsets. Or, if 10250 ** the buffer contains a changeset, so must have the earlier calls to this 10251 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 10252 ** to the changegroup. 10253 ** 10254 ** Rows within the changeset and changegroup are identified by the values in 10255 ** their PRIMARY KEY columns. A change in the changeset is considered to 10256 ** apply to the same row as a change already present in the changegroup if 10257 ** the two rows have the same primary key. 10258 ** 10259 ** Changes to rows that do not already appear in the changegroup are 10260 ** simply copied into it. Or, if both the new changeset and the changegroup 10261 ** contain changes that apply to a single row, the final contents of the 10262 ** changegroup depends on the type of each change, as follows: 10263 ** 10264 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 10265 ** <tr><th style="white-space:pre">Existing Change </th> 10266 ** <th style="white-space:pre">New Change </th> 10267 ** <th>Output Change 10268 ** <tr><td>INSERT <td>INSERT <td> 10269 ** The new change is ignored. This case does not occur if the new 10270 ** changeset was recorded immediately after the changesets already 10271 ** added to the changegroup. 10272 ** <tr><td>INSERT <td>UPDATE <td> 10273 ** The INSERT change remains in the changegroup. The values in the 10274 ** INSERT change are modified as if the row was inserted by the 10275 ** existing change and then updated according to the new change. 10276 ** <tr><td>INSERT <td>DELETE <td> 10277 ** The existing INSERT is removed from the changegroup. The DELETE is 10278 ** not added. 10279 ** <tr><td>UPDATE <td>INSERT <td> 10280 ** The new change is ignored. This case does not occur if the new 10281 ** changeset was recorded immediately after the changesets already 10282 ** added to the changegroup. 10283 ** <tr><td>UPDATE <td>UPDATE <td> 10284 ** The existing UPDATE remains within the changegroup. It is amended 10285 ** so that the accompanying values are as if the row was updated once 10286 ** by the existing change and then again by the new change. 10287 ** <tr><td>UPDATE <td>DELETE <td> 10288 ** The existing UPDATE is replaced by the new DELETE within the 10289 ** changegroup. 10290 ** <tr><td>DELETE <td>INSERT <td> 10291 ** If one or more of the column values in the row inserted by the 10292 ** new change differ from those in the row deleted by the existing 10293 ** change, the existing DELETE is replaced by an UPDATE within the 10294 ** changegroup. Otherwise, if the inserted row is exactly the same 10295 ** as the deleted row, the existing DELETE is simply discarded. 10296 ** <tr><td>DELETE <td>UPDATE <td> 10297 ** The new change is ignored. This case does not occur if the new 10298 ** changeset was recorded immediately after the changesets already 10299 ** added to the changegroup. 10300 ** <tr><td>DELETE <td>DELETE <td> 10301 ** The new change is ignored. This case does not occur if the new 10302 ** changeset was recorded immediately after the changesets already 10303 ** added to the changegroup. 10304 ** </table> 10305 ** 10306 ** If the new changeset contains changes to a table that is already present 10307 ** in the changegroup, then the number of columns and the position of the 10308 ** primary key columns for the table must be consistent. If this is not the 10309 ** case, this function fails with SQLITE_SCHEMA. If the input changeset 10310 ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 10311 ** returned. Or, if an out-of-memory condition occurs during processing, this 10312 ** function returns SQLITE_NOMEM. In all cases, if an error occurs the 10313 ** final contents of the changegroup is undefined. 10314 ** 10315 ** If no error occurs, SQLITE_OK is returned. 10316 */ 10317 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 10318 10319 /* 10320 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 10321 ** METHOD: sqlite3_changegroup 10322 ** 10323 ** Obtain a buffer containing a changeset (or patchset) representing the 10324 ** current contents of the changegroup. If the inputs to the changegroup 10325 ** were themselves changesets, the output is a changeset. Or, if the 10326 ** inputs were patchsets, the output is also a patchset. 10327 ** 10328 ** As with the output of the sqlite3session_changeset() and 10329 ** sqlite3session_patchset() functions, all changes related to a single 10330 ** table are grouped together in the output of this function. Tables appear 10331 ** in the same order as for the very first changeset added to the changegroup. 10332 ** If the second or subsequent changesets added to the changegroup contain 10333 ** changes for tables that do not appear in the first changeset, they are 10334 ** appended onto the end of the output changeset, again in the order in 10335 ** which they are first encountered. 10336 ** 10337 ** If an error occurs, an SQLite error code is returned and the output 10338 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 10339 ** is returned and the output variables are set to the size of and a 10340 ** pointer to the output buffer, respectively. In this case it is the 10341 ** responsibility of the caller to eventually free the buffer using a 10342 ** call to sqlite3_free(). 10343 */ 10344 SQLITE_API int sqlite3changegroup_output( 10345 sqlite3_changegroup*, 10346 int *pnData, /* OUT: Size of output buffer in bytes */ 10347 void **ppData /* OUT: Pointer to output buffer */ 10348 ); 10349 10350 /* 10351 ** CAPI3REF: Delete A Changegroup Object 10352 ** DESTRUCTOR: sqlite3_changegroup 10353 */ 10354 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 10355 10356 /* 10357 ** CAPI3REF: Apply A Changeset To A Database 10358 ** 10359 ** Apply a changeset or patchset to a database. These functions attempt to 10360 ** update the "main" database attached to handle db with the changes found in 10361 ** the changeset passed via the second and third arguments. 10362 ** 10363 ** The fourth argument (xFilter) passed to these functions is the "filter 10364 ** callback". If it is not NULL, then for each table affected by at least one 10365 ** change in the changeset, the filter callback is invoked with 10366 ** the table name as the second argument, and a copy of the context pointer 10367 ** passed as the sixth argument as the first. If the "filter callback" 10368 ** returns zero, then no attempt is made to apply any changes to the table. 10369 ** Otherwise, if the return value is non-zero or the xFilter argument to 10370 ** is NULL, all changes related to the table are attempted. 10371 ** 10372 ** For each table that is not excluded by the filter callback, this function 10373 ** tests that the target database contains a compatible table. A table is 10374 ** considered compatible if all of the following are true: 10375 ** 10376 ** <ul> 10377 ** <li> The table has the same name as the name recorded in the 10378 ** changeset, and 10379 ** <li> The table has at least as many columns as recorded in the 10380 ** changeset, and 10381 ** <li> The table has primary key columns in the same position as 10382 ** recorded in the changeset. 10383 ** </ul> 10384 ** 10385 ** If there is no compatible table, it is not an error, but none of the 10386 ** changes associated with the table are applied. A warning message is issued 10387 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 10388 ** one such warning is issued for each table in the changeset. 10389 ** 10390 ** For each change for which there is a compatible table, an attempt is made 10391 ** to modify the table contents according to the UPDATE, INSERT or DELETE 10392 ** change. If a change cannot be applied cleanly, the conflict handler 10393 ** function passed as the fifth argument to sqlite3changeset_apply() may be 10394 ** invoked. A description of exactly when the conflict handler is invoked for 10395 ** each type of change is below. 10396 ** 10397 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 10398 ** of passing anything other than a valid function pointer as the xConflict 10399 ** argument are undefined. 10400 ** 10401 ** Each time the conflict handler function is invoked, it must return one 10402 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 10403 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 10404 ** if the second argument passed to the conflict handler is either 10405 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 10406 ** returns an illegal value, any changes already made are rolled back and 10407 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 10408 ** actions are taken by sqlite3changeset_apply() depending on the value 10409 ** returned by each invocation of the conflict-handler function. Refer to 10410 ** the documentation for the three 10411 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 10412 ** 10413 ** <dl> 10414 ** <dt>DELETE Changes<dd> 10415 ** For each DELETE change, the function checks if the target database 10416 ** contains a row with the same primary key value (or values) as the 10417 ** original row values stored in the changeset. If it does, and the values 10418 ** stored in all non-primary key columns also match the values stored in 10419 ** the changeset the row is deleted from the target database. 10420 ** 10421 ** If a row with matching primary key values is found, but one or more of 10422 ** the non-primary key fields contains a value different from the original 10423 ** row value stored in the changeset, the conflict-handler function is 10424 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 10425 ** database table has more columns than are recorded in the changeset, 10426 ** only the values of those non-primary key fields are compared against 10427 ** the current database contents - any trailing database table columns 10428 ** are ignored. 10429 ** 10430 ** If no row with matching primary key values is found in the database, 10431 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 10432 ** passed as the second argument. 10433 ** 10434 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 10435 ** (which can only happen if a foreign key constraint is violated), the 10436 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 10437 ** passed as the second argument. This includes the case where the DELETE 10438 ** operation is attempted because an earlier call to the conflict handler 10439 ** function returned [SQLITE_CHANGESET_REPLACE]. 10440 ** 10441 ** <dt>INSERT Changes<dd> 10442 ** For each INSERT change, an attempt is made to insert the new row into 10443 ** the database. If the changeset row contains fewer fields than the 10444 ** database table, the trailing fields are populated with their default 10445 ** values. 10446 ** 10447 ** If the attempt to insert the row fails because the database already 10448 ** contains a row with the same primary key values, the conflict handler 10449 ** function is invoked with the second argument set to 10450 ** [SQLITE_CHANGESET_CONFLICT]. 10451 ** 10452 ** If the attempt to insert the row fails because of some other constraint 10453 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 10454 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 10455 ** This includes the case where the INSERT operation is re-attempted because 10456 ** an earlier call to the conflict handler function returned 10457 ** [SQLITE_CHANGESET_REPLACE]. 10458 ** 10459 ** <dt>UPDATE Changes<dd> 10460 ** For each UPDATE change, the function checks if the target database 10461 ** contains a row with the same primary key value (or values) as the 10462 ** original row values stored in the changeset. If it does, and the values 10463 ** stored in all modified non-primary key columns also match the values 10464 ** stored in the changeset the row is updated within the target database. 10465 ** 10466 ** If a row with matching primary key values is found, but one or more of 10467 ** the modified non-primary key fields contains a value different from an 10468 ** original row value stored in the changeset, the conflict-handler function 10469 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 10470 ** UPDATE changes only contain values for non-primary key fields that are 10471 ** to be modified, only those fields need to match the original values to 10472 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 10473 ** 10474 ** If no row with matching primary key values is found in the database, 10475 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 10476 ** passed as the second argument. 10477 ** 10478 ** If the UPDATE operation is attempted, but SQLite returns 10479 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 10480 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 10481 ** This includes the case where the UPDATE operation is attempted after 10482 ** an earlier call to the conflict handler function returned 10483 ** [SQLITE_CHANGESET_REPLACE]. 10484 ** </dl> 10485 ** 10486 ** It is safe to execute SQL statements, including those that write to the 10487 ** table that the callback related to, from within the xConflict callback. 10488 ** This can be used to further customize the applications conflict 10489 ** resolution strategy. 10490 ** 10491 ** All changes made by these functions are enclosed in a savepoint transaction. 10492 ** If any other error (aside from a constraint failure when attempting to 10493 ** write to the target database) occurs, then the savepoint transaction is 10494 ** rolled back, restoring the target database to its original state, and an 10495 ** SQLite error code returned. 10496 ** 10497 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 10498 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 10499 ** may set (*ppRebase) to point to a "rebase" that may be used with the 10500 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 10501 ** is set to the size of the buffer in bytes. It is the responsibility of the 10502 ** caller to eventually free any such buffer using sqlite3_free(). The buffer 10503 ** is only allocated and populated if one or more conflicts were encountered 10504 ** while applying the patchset. See comments surrounding the sqlite3_rebaser 10505 ** APIs for further details. 10506 ** 10507 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 10508 ** may be modified by passing a combination of 10509 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 10510 ** 10511 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 10512 ** and therefore subject to change. 10513 */ 10514 SQLITE_API int sqlite3changeset_apply( 10515 sqlite3 *db, /* Apply change to "main" db of this handle */ 10516 int nChangeset, /* Size of changeset in bytes */ 10517 void *pChangeset, /* Changeset blob */ 10518 int(*xFilter)( 10519 void *pCtx, /* Copy of sixth arg to _apply() */ 10520 const char *zTab /* Table name */ 10521 ), 10522 int(*xConflict)( 10523 void *pCtx, /* Copy of sixth arg to _apply() */ 10524 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 10525 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 10526 ), 10527 void *pCtx /* First argument passed to xConflict */ 10528 ); 10529 SQLITE_API int sqlite3changeset_apply_v2( 10530 sqlite3 *db, /* Apply change to "main" db of this handle */ 10531 int nChangeset, /* Size of changeset in bytes */ 10532 void *pChangeset, /* Changeset blob */ 10533 int(*xFilter)( 10534 void *pCtx, /* Copy of sixth arg to _apply() */ 10535 const char *zTab /* Table name */ 10536 ), 10537 int(*xConflict)( 10538 void *pCtx, /* Copy of sixth arg to _apply() */ 10539 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 10540 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 10541 ), 10542 void *pCtx, /* First argument passed to xConflict */ 10543 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 10544 int flags /* Combination of SESSION_APPLY_* flags */ 10545 ); 10546 10547 /* 10548 ** CAPI3REF: Flags for sqlite3changeset_apply_v2 10549 ** 10550 ** The following flags may passed via the 9th parameter to 10551 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 10552 ** 10553 ** <dl> 10554 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 10555 ** Usually, the sessions module encloses all operations performed by 10556 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 10557 ** SAVEPOINT is committed if the changeset or patchset is successfully 10558 ** applied, or rolled back if an error occurs. Specifying this flag 10559 ** causes the sessions module to omit this savepoint. In this case, if the 10560 ** caller has an open transaction or savepoint when apply_v2() is called, 10561 ** it may revert the partially applied changeset by rolling it back. 10562 */ 10563 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 10564 10565 /* 10566 ** CAPI3REF: Constants Passed To The Conflict Handler 10567 ** 10568 ** Values that may be passed as the second argument to a conflict-handler. 10569 ** 10570 ** <dl> 10571 ** <dt>SQLITE_CHANGESET_DATA<dd> 10572 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 10573 ** when processing a DELETE or UPDATE change if a row with the required 10574 ** PRIMARY KEY fields is present in the database, but one or more other 10575 ** (non primary-key) fields modified by the update do not contain the 10576 ** expected "before" values. 10577 ** 10578 ** The conflicting row, in this case, is the database row with the matching 10579 ** primary key. 10580 ** 10581 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 10582 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 10583 ** argument when processing a DELETE or UPDATE change if a row with the 10584 ** required PRIMARY KEY fields is not present in the database. 10585 ** 10586 ** There is no conflicting row in this case. The results of invoking the 10587 ** sqlite3changeset_conflict() API are undefined. 10588 ** 10589 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 10590 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 10591 ** handler while processing an INSERT change if the operation would result 10592 ** in duplicate primary key values. 10593 ** 10594 ** The conflicting row in this case is the database row with the matching 10595 ** primary key. 10596 ** 10597 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 10598 ** If foreign key handling is enabled, and applying a changeset leaves the 10599 ** database in a state containing foreign key violations, the conflict 10600 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 10601 ** exactly once before the changeset is committed. If the conflict handler 10602 ** returns CHANGESET_OMIT, the changes, including those that caused the 10603 ** foreign key constraint violation, are committed. Or, if it returns 10604 ** CHANGESET_ABORT, the changeset is rolled back. 10605 ** 10606 ** No current or conflicting row information is provided. The only function 10607 ** it is possible to call on the supplied sqlite3_changeset_iter handle 10608 ** is sqlite3changeset_fk_conflicts(). 10609 ** 10610 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 10611 ** If any other constraint violation occurs while applying a change (i.e. 10612 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 10613 ** invoked with CHANGESET_CONSTRAINT as the second argument. 10614 ** 10615 ** There is no conflicting row in this case. The results of invoking the 10616 ** sqlite3changeset_conflict() API are undefined. 10617 ** 10618 ** </dl> 10619 */ 10620 #define SQLITE_CHANGESET_DATA 1 10621 #define SQLITE_CHANGESET_NOTFOUND 2 10622 #define SQLITE_CHANGESET_CONFLICT 3 10623 #define SQLITE_CHANGESET_CONSTRAINT 4 10624 #define SQLITE_CHANGESET_FOREIGN_KEY 5 10625 10626 /* 10627 ** CAPI3REF: Constants Returned By The Conflict Handler 10628 ** 10629 ** A conflict handler callback must return one of the following three values. 10630 ** 10631 ** <dl> 10632 ** <dt>SQLITE_CHANGESET_OMIT<dd> 10633 ** If a conflict handler returns this value no special action is taken. The 10634 ** change that caused the conflict is not applied. The session module 10635 ** continues to the next change in the changeset. 10636 ** 10637 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 10638 ** This value may only be returned if the second argument to the conflict 10639 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 10640 ** is not the case, any changes applied so far are rolled back and the 10641 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 10642 ** 10643 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 10644 ** handler, then the conflicting row is either updated or deleted, depending 10645 ** on the type of change. 10646 ** 10647 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 10648 ** handler, then the conflicting row is removed from the database and a 10649 ** second attempt to apply the change is made. If this second attempt fails, 10650 ** the original row is restored to the database before continuing. 10651 ** 10652 ** <dt>SQLITE_CHANGESET_ABORT<dd> 10653 ** If this value is returned, any changes applied so far are rolled back 10654 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 10655 ** </dl> 10656 */ 10657 #define SQLITE_CHANGESET_OMIT 0 10658 #define SQLITE_CHANGESET_REPLACE 1 10659 #define SQLITE_CHANGESET_ABORT 2 10660 10661 /* 10662 ** CAPI3REF: Rebasing changesets 10663 ** EXPERIMENTAL 10664 ** 10665 ** Suppose there is a site hosting a database in state S0. And that 10666 ** modifications are made that move that database to state S1 and a 10667 ** changeset recorded (the "local" changeset). Then, a changeset based 10668 ** on S0 is received from another site (the "remote" changeset) and 10669 ** applied to the database. The database is then in state 10670 ** (S1+"remote"), where the exact state depends on any conflict 10671 ** resolution decisions (OMIT or REPLACE) made while applying "remote". 10672 ** Rebasing a changeset is to update it to take those conflict 10673 ** resolution decisions into account, so that the same conflicts 10674 ** do not have to be resolved elsewhere in the network. 10675 ** 10676 ** For example, if both the local and remote changesets contain an 10677 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 10678 ** 10679 ** local: INSERT INTO t1 VALUES(1, 'v1'); 10680 ** remote: INSERT INTO t1 VALUES(1, 'v2'); 10681 ** 10682 ** and the conflict resolution is REPLACE, then the INSERT change is 10683 ** removed from the local changeset (it was overridden). Or, if the 10684 ** conflict resolution was "OMIT", then the local changeset is modified 10685 ** to instead contain: 10686 ** 10687 ** UPDATE t1 SET b = 'v2' WHERE a=1; 10688 ** 10689 ** Changes within the local changeset are rebased as follows: 10690 ** 10691 ** <dl> 10692 ** <dt>Local INSERT<dd> 10693 ** This may only conflict with a remote INSERT. If the conflict 10694 ** resolution was OMIT, then add an UPDATE change to the rebased 10695 ** changeset. Or, if the conflict resolution was REPLACE, add 10696 ** nothing to the rebased changeset. 10697 ** 10698 ** <dt>Local DELETE<dd> 10699 ** This may conflict with a remote UPDATE or DELETE. In both cases the 10700 ** only possible resolution is OMIT. If the remote operation was a 10701 ** DELETE, then add no change to the rebased changeset. If the remote 10702 ** operation was an UPDATE, then the old.* fields of change are updated 10703 ** to reflect the new.* values in the UPDATE. 10704 ** 10705 ** <dt>Local UPDATE<dd> 10706 ** This may conflict with a remote UPDATE or DELETE. If it conflicts 10707 ** with a DELETE, and the conflict resolution was OMIT, then the update 10708 ** is changed into an INSERT. Any undefined values in the new.* record 10709 ** from the update change are filled in using the old.* values from 10710 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 10711 ** the UPDATE change is simply omitted from the rebased changeset. 10712 ** 10713 ** If conflict is with a remote UPDATE and the resolution is OMIT, then 10714 ** the old.* values are rebased using the new.* values in the remote 10715 ** change. Or, if the resolution is REPLACE, then the change is copied 10716 ** into the rebased changeset with updates to columns also updated by 10717 ** the conflicting remote UPDATE removed. If this means no columns would 10718 ** be updated, the change is omitted. 10719 ** </dl> 10720 ** 10721 ** A local change may be rebased against multiple remote changes 10722 ** simultaneously. If a single key is modified by multiple remote 10723 ** changesets, they are combined as follows before the local changeset 10724 ** is rebased: 10725 ** 10726 ** <ul> 10727 ** <li> If there has been one or more REPLACE resolutions on a 10728 ** key, it is rebased according to a REPLACE. 10729 ** 10730 ** <li> If there have been no REPLACE resolutions on a key, then 10731 ** the local changeset is rebased according to the most recent 10732 ** of the OMIT resolutions. 10733 ** </ul> 10734 ** 10735 ** Note that conflict resolutions from multiple remote changesets are 10736 ** combined on a per-field basis, not per-row. This means that in the 10737 ** case of multiple remote UPDATE operations, some fields of a single 10738 ** local change may be rebased for REPLACE while others are rebased for 10739 ** OMIT. 10740 ** 10741 ** In order to rebase a local changeset, the remote changeset must first 10742 ** be applied to the local database using sqlite3changeset_apply_v2() and 10743 ** the buffer of rebase information captured. Then: 10744 ** 10745 ** <ol> 10746 ** <li> An sqlite3_rebaser object is created by calling 10747 ** sqlite3rebaser_create(). 10748 ** <li> The new object is configured with the rebase buffer obtained from 10749 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 10750 ** If the local changeset is to be rebased against multiple remote 10751 ** changesets, then sqlite3rebaser_configure() should be called 10752 ** multiple times, in the same order that the multiple 10753 ** sqlite3changeset_apply_v2() calls were made. 10754 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 10755 ** <li> The sqlite3_rebaser object is deleted by calling 10756 ** sqlite3rebaser_delete(). 10757 ** </ol> 10758 */ 10759 typedef struct sqlite3_rebaser sqlite3_rebaser; 10760 10761 /* 10762 ** CAPI3REF: Create a changeset rebaser object. 10763 ** EXPERIMENTAL 10764 ** 10765 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 10766 ** point to the new object and return SQLITE_OK. Otherwise, if an error 10767 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 10768 ** to NULL. 10769 */ 10770 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 10771 10772 /* 10773 ** CAPI3REF: Configure a changeset rebaser object. 10774 ** EXPERIMENTAL 10775 ** 10776 ** Configure the changeset rebaser object to rebase changesets according 10777 ** to the conflict resolutions described by buffer pRebase (size nRebase 10778 ** bytes), which must have been obtained from a previous call to 10779 ** sqlite3changeset_apply_v2(). 10780 */ 10781 SQLITE_API int sqlite3rebaser_configure( 10782 sqlite3_rebaser*, 10783 int nRebase, const void *pRebase 10784 ); 10785 10786 /* 10787 ** CAPI3REF: Rebase a changeset 10788 ** EXPERIMENTAL 10789 ** 10790 ** Argument pIn must point to a buffer containing a changeset nIn bytes 10791 ** in size. This function allocates and populates a buffer with a copy 10792 ** of the changeset rebased rebased according to the configuration of the 10793 ** rebaser object passed as the first argument. If successful, (*ppOut) 10794 ** is set to point to the new buffer containing the rebased changset and 10795 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 10796 ** responsibility of the caller to eventually free the new buffer using 10797 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 10798 ** are set to zero and an SQLite error code returned. 10799 */ 10800 SQLITE_API int sqlite3rebaser_rebase( 10801 sqlite3_rebaser*, 10802 int nIn, const void *pIn, 10803 int *pnOut, void **ppOut 10804 ); 10805 10806 /* 10807 ** CAPI3REF: Delete a changeset rebaser object. 10808 ** EXPERIMENTAL 10809 ** 10810 ** Delete the changeset rebaser object and all associated resources. There 10811 ** should be one call to this function for each successful invocation 10812 ** of sqlite3rebaser_create(). 10813 */ 10814 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 10815 10816 /* 10817 ** CAPI3REF: Streaming Versions of API functions. 10818 ** 10819 ** The six streaming API xxx_strm() functions serve similar purposes to the 10820 ** corresponding non-streaming API functions: 10821 ** 10822 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 10823 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 10824 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 10825 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 10826 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 10827 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 10828 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 10829 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 10830 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 10831 ** </table> 10832 ** 10833 ** Non-streaming functions that accept changesets (or patchsets) as input 10834 ** require that the entire changeset be stored in a single buffer in memory. 10835 ** Similarly, those that return a changeset or patchset do so by returning 10836 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 10837 ** Normally this is convenient. However, if an application running in a 10838 ** low-memory environment is required to handle very large changesets, the 10839 ** large contiguous memory allocations required can become onerous. 10840 ** 10841 ** In order to avoid this problem, instead of a single large buffer, input 10842 ** is passed to a streaming API functions by way of a callback function that 10843 ** the sessions module invokes to incrementally request input data as it is 10844 ** required. In all cases, a pair of API function parameters such as 10845 ** 10846 ** <pre> 10847 ** int nChangeset, 10848 ** void *pChangeset, 10849 ** </pre> 10850 ** 10851 ** Is replaced by: 10852 ** 10853 ** <pre> 10854 ** int (*xInput)(void *pIn, void *pData, int *pnData), 10855 ** void *pIn, 10856 ** </pre> 10857 ** 10858 ** Each time the xInput callback is invoked by the sessions module, the first 10859 ** argument passed is a copy of the supplied pIn context pointer. The second 10860 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 10861 ** error occurs the xInput method should copy up to (*pnData) bytes of data 10862 ** into the buffer and set (*pnData) to the actual number of bytes copied 10863 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 10864 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 10865 ** error code should be returned. In all cases, if an xInput callback returns 10866 ** an error, all processing is abandoned and the streaming API function 10867 ** returns a copy of the error code to the caller. 10868 ** 10869 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 10870 ** invoked by the sessions module at any point during the lifetime of the 10871 ** iterator. If such an xInput callback returns an error, the iterator enters 10872 ** an error state, whereby all subsequent calls to iterator functions 10873 ** immediately fail with the same error code as returned by xInput. 10874 ** 10875 ** Similarly, streaming API functions that return changesets (or patchsets) 10876 ** return them in chunks by way of a callback function instead of via a 10877 ** pointer to a single large buffer. In this case, a pair of parameters such 10878 ** as: 10879 ** 10880 ** <pre> 10881 ** int *pnChangeset, 10882 ** void **ppChangeset, 10883 ** </pre> 10884 ** 10885 ** Is replaced by: 10886 ** 10887 ** <pre> 10888 ** int (*xOutput)(void *pOut, const void *pData, int nData), 10889 ** void *pOut 10890 ** </pre> 10891 ** 10892 ** The xOutput callback is invoked zero or more times to return data to 10893 ** the application. The first parameter passed to each call is a copy of the 10894 ** pOut pointer supplied by the application. The second parameter, pData, 10895 ** points to a buffer nData bytes in size containing the chunk of output 10896 ** data being returned. If the xOutput callback successfully processes the 10897 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 10898 ** it should return some other SQLite error code. In this case processing 10899 ** is immediately abandoned and the streaming API function returns a copy 10900 ** of the xOutput error code to the application. 10901 ** 10902 ** The sessions module never invokes an xOutput callback with the third 10903 ** parameter set to a value less than or equal to zero. Other than this, 10904 ** no guarantees are made as to the size of the chunks of data returned. 10905 */ 10906 SQLITE_API int sqlite3changeset_apply_strm( 10907 sqlite3 *db, /* Apply change to "main" db of this handle */ 10908 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 10909 void *pIn, /* First arg for xInput */ 10910 int(*xFilter)( 10911 void *pCtx, /* Copy of sixth arg to _apply() */ 10912 const char *zTab /* Table name */ 10913 ), 10914 int(*xConflict)( 10915 void *pCtx, /* Copy of sixth arg to _apply() */ 10916 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 10917 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 10918 ), 10919 void *pCtx /* First argument passed to xConflict */ 10920 ); 10921 SQLITE_API int sqlite3changeset_apply_v2_strm( 10922 sqlite3 *db, /* Apply change to "main" db of this handle */ 10923 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 10924 void *pIn, /* First arg for xInput */ 10925 int(*xFilter)( 10926 void *pCtx, /* Copy of sixth arg to _apply() */ 10927 const char *zTab /* Table name */ 10928 ), 10929 int(*xConflict)( 10930 void *pCtx, /* Copy of sixth arg to _apply() */ 10931 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 10932 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 10933 ), 10934 void *pCtx, /* First argument passed to xConflict */ 10935 void **ppRebase, int *pnRebase, 10936 int flags 10937 ); 10938 SQLITE_API int sqlite3changeset_concat_strm( 10939 int (*xInputA)(void *pIn, void *pData, int *pnData), 10940 void *pInA, 10941 int (*xInputB)(void *pIn, void *pData, int *pnData), 10942 void *pInB, 10943 int (*xOutput)(void *pOut, const void *pData, int nData), 10944 void *pOut 10945 ); 10946 SQLITE_API int sqlite3changeset_invert_strm( 10947 int (*xInput)(void *pIn, void *pData, int *pnData), 10948 void *pIn, 10949 int (*xOutput)(void *pOut, const void *pData, int nData), 10950 void *pOut 10951 ); 10952 SQLITE_API int sqlite3changeset_start_strm( 10953 sqlite3_changeset_iter **pp, 10954 int (*xInput)(void *pIn, void *pData, int *pnData), 10955 void *pIn 10956 ); 10957 SQLITE_API int sqlite3session_changeset_strm( 10958 sqlite3_session *pSession, 10959 int (*xOutput)(void *pOut, const void *pData, int nData), 10960 void *pOut 10961 ); 10962 SQLITE_API int sqlite3session_patchset_strm( 10963 sqlite3_session *pSession, 10964 int (*xOutput)(void *pOut, const void *pData, int nData), 10965 void *pOut 10966 ); 10967 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 10968 int (*xInput)(void *pIn, void *pData, int *pnData), 10969 void *pIn 10970 ); 10971 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 10972 int (*xOutput)(void *pOut, const void *pData, int nData), 10973 void *pOut 10974 ); 10975 SQLITE_API int sqlite3rebaser_rebase_strm( 10976 sqlite3_rebaser *pRebaser, 10977 int (*xInput)(void *pIn, void *pData, int *pnData), 10978 void *pIn, 10979 int (*xOutput)(void *pOut, const void *pData, int nData), 10980 void *pOut 10981 ); 10982 10983 10984 /* 10985 ** Make sure we can call this stuff from C++. 10986 */ 10987 #ifdef __cplusplus 10988 } 10989 #endif 10990 10991 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 10992 10993 /******** End of sqlite3session.h *********/ 10994 /******** Begin file fts5.h *********/ 10995 /* 10996 ** 2014 May 31 10997 ** 10998 ** The author disclaims copyright to this source code. In place of 10999 ** a legal notice, here is a blessing: 11000 ** 11001 ** May you do good and not evil. 11002 ** May you find forgiveness for yourself and forgive others. 11003 ** May you share freely, never taking more than you give. 11004 ** 11005 ****************************************************************************** 11006 ** 11007 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 11008 ** FTS5 may be extended with: 11009 ** 11010 ** * custom tokenizers, and 11011 ** * custom auxiliary functions. 11012 */ 11013 11014 11015 #ifndef _FTS5_H 11016 #define _FTS5_H 11017 11018 11019 #ifdef __cplusplus 11020 extern "C" { 11021 #endif 11022 11023 /************************************************************************* 11024 ** CUSTOM AUXILIARY FUNCTIONS 11025 ** 11026 ** Virtual table implementations may overload SQL functions by implementing 11027 ** the sqlite3_module.xFindFunction() method. 11028 */ 11029 11030 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 11031 typedef struct Fts5Context Fts5Context; 11032 typedef struct Fts5PhraseIter Fts5PhraseIter; 11033 11034 typedef void (*fts5_extension_function)( 11035 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 11036 Fts5Context *pFts, /* First arg to pass to pApi functions */ 11037 sqlite3_context *pCtx, /* Context for returning result/error */ 11038 int nVal, /* Number of values in apVal[] array */ 11039 sqlite3_value **apVal /* Array of trailing arguments */ 11040 ); 11041 11042 struct Fts5PhraseIter { 11043 const unsigned char *a; 11044 const unsigned char *b; 11045 }; 11046 11047 /* 11048 ** EXTENSION API FUNCTIONS 11049 ** 11050 ** xUserData(pFts): 11051 ** Return a copy of the context pointer the extension function was 11052 ** registered with. 11053 ** 11054 ** xColumnTotalSize(pFts, iCol, pnToken): 11055 ** If parameter iCol is less than zero, set output variable *pnToken 11056 ** to the total number of tokens in the FTS5 table. Or, if iCol is 11057 ** non-negative but less than the number of columns in the table, return 11058 ** the total number of tokens in column iCol, considering all rows in 11059 ** the FTS5 table. 11060 ** 11061 ** If parameter iCol is greater than or equal to the number of columns 11062 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11063 ** an OOM condition or IO error), an appropriate SQLite error code is 11064 ** returned. 11065 ** 11066 ** xColumnCount(pFts): 11067 ** Return the number of columns in the table. 11068 ** 11069 ** xColumnSize(pFts, iCol, pnToken): 11070 ** If parameter iCol is less than zero, set output variable *pnToken 11071 ** to the total number of tokens in the current row. Or, if iCol is 11072 ** non-negative but less than the number of columns in the table, set 11073 ** *pnToken to the number of tokens in column iCol of the current row. 11074 ** 11075 ** If parameter iCol is greater than or equal to the number of columns 11076 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11077 ** an OOM condition or IO error), an appropriate SQLite error code is 11078 ** returned. 11079 ** 11080 ** This function may be quite inefficient if used with an FTS5 table 11081 ** created with the "columnsize=0" option. 11082 ** 11083 ** xColumnText: 11084 ** This function attempts to retrieve the text of column iCol of the 11085 ** current document. If successful, (*pz) is set to point to a buffer 11086 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 11087 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 11088 ** if an error occurs, an SQLite error code is returned and the final values 11089 ** of (*pz) and (*pn) are undefined. 11090 ** 11091 ** xPhraseCount: 11092 ** Returns the number of phrases in the current query expression. 11093 ** 11094 ** xPhraseSize: 11095 ** Returns the number of tokens in phrase iPhrase of the query. Phrases 11096 ** are numbered starting from zero. 11097 ** 11098 ** xInstCount: 11099 ** Set *pnInst to the total number of occurrences of all phrases within 11100 ** the query within the current row. Return SQLITE_OK if successful, or 11101 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 11102 ** 11103 ** This API can be quite slow if used with an FTS5 table created with the 11104 ** "detail=none" or "detail=column" option. If the FTS5 table is created 11105 ** with either "detail=none" or "detail=column" and "content=" option 11106 ** (i.e. if it is a contentless table), then this API always returns 0. 11107 ** 11108 ** xInst: 11109 ** Query for the details of phrase match iIdx within the current row. 11110 ** Phrase matches are numbered starting from zero, so the iIdx argument 11111 ** should be greater than or equal to zero and smaller than the value 11112 ** output by xInstCount(). 11113 ** 11114 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol 11115 ** to the column in which it occurs and *piOff the token offset of the 11116 ** first token of the phrase. The exception is if the table was created 11117 ** with the offsets=0 option specified. In this case *piOff is always 11118 ** set to -1. 11119 ** 11120 ** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM) 11121 ** if an error occurs. 11122 ** 11123 ** This API can be quite slow if used with an FTS5 table created with the 11124 ** "detail=none" or "detail=column" option. 11125 ** 11126 ** xRowid: 11127 ** Returns the rowid of the current row. 11128 ** 11129 ** xTokenize: 11130 ** Tokenize text using the tokenizer belonging to the FTS5 table. 11131 ** 11132 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 11133 ** This API function is used to query the FTS table for phrase iPhrase 11134 ** of the current query. Specifically, a query equivalent to: 11135 ** 11136 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 11137 ** 11138 ** with $p set to a phrase equivalent to the phrase iPhrase of the 11139 ** current query is executed. Any column filter that applies to 11140 ** phrase iPhrase of the current query is included in $p. For each 11141 ** row visited, the callback function passed as the fourth argument 11142 ** is invoked. The context and API objects passed to the callback 11143 ** function may be used to access the properties of each matched row. 11144 ** Invoking Api.xUserData() returns a copy of the pointer passed as 11145 ** the third argument to pUserData. 11146 ** 11147 ** If the callback function returns any value other than SQLITE_OK, the 11148 ** query is abandoned and the xQueryPhrase function returns immediately. 11149 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 11150 ** Otherwise, the error code is propagated upwards. 11151 ** 11152 ** If the query runs to completion without incident, SQLITE_OK is returned. 11153 ** Or, if some error occurs before the query completes or is aborted by 11154 ** the callback, an SQLite error code is returned. 11155 ** 11156 ** 11157 ** xSetAuxdata(pFts5, pAux, xDelete) 11158 ** 11159 ** Save the pointer passed as the second argument as the extension functions 11160 ** "auxiliary data". The pointer may then be retrieved by the current or any 11161 ** future invocation of the same fts5 extension function made as part of 11162 ** of the same MATCH query using the xGetAuxdata() API. 11163 ** 11164 ** Each extension function is allocated a single auxiliary data slot for 11165 ** each FTS query (MATCH expression). If the extension function is invoked 11166 ** more than once for a single FTS query, then all invocations share a 11167 ** single auxiliary data context. 11168 ** 11169 ** If there is already an auxiliary data pointer when this function is 11170 ** invoked, then it is replaced by the new pointer. If an xDelete callback 11171 ** was specified along with the original pointer, it is invoked at this 11172 ** point. 11173 ** 11174 ** The xDelete callback, if one is specified, is also invoked on the 11175 ** auxiliary data pointer after the FTS5 query has finished. 11176 ** 11177 ** If an error (e.g. an OOM condition) occurs within this function, an 11178 ** the auxiliary data is set to NULL and an error code returned. If the 11179 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 11180 ** pointer before returning. 11181 ** 11182 ** 11183 ** xGetAuxdata(pFts5, bClear) 11184 ** 11185 ** Returns the current auxiliary data pointer for the fts5 extension 11186 ** function. See the xSetAuxdata() method for details. 11187 ** 11188 ** If the bClear argument is non-zero, then the auxiliary data is cleared 11189 ** (set to NULL) before this function returns. In this case the xDelete, 11190 ** if any, is not invoked. 11191 ** 11192 ** 11193 ** xRowCount(pFts5, pnRow) 11194 ** 11195 ** This function is used to retrieve the total number of rows in the table. 11196 ** In other words, the same value that would be returned by: 11197 ** 11198 ** SELECT count(*) FROM ftstable; 11199 ** 11200 ** xPhraseFirst() 11201 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 11202 ** method, to iterate through all instances of a single query phrase within 11203 ** the current row. This is the same information as is accessible via the 11204 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 11205 ** to use, this API may be faster under some circumstances. To iterate 11206 ** through instances of phrase iPhrase, use the following code: 11207 ** 11208 ** Fts5PhraseIter iter; 11209 ** int iCol, iOff; 11210 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 11211 ** iCol>=0; 11212 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 11213 ** ){ 11214 ** // An instance of phrase iPhrase at offset iOff of column iCol 11215 ** } 11216 ** 11217 ** The Fts5PhraseIter structure is defined above. Applications should not 11218 ** modify this structure directly - it should only be used as shown above 11219 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 11220 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 11221 ** 11222 ** This API can be quite slow if used with an FTS5 table created with the 11223 ** "detail=none" or "detail=column" option. If the FTS5 table is created 11224 ** with either "detail=none" or "detail=column" and "content=" option 11225 ** (i.e. if it is a contentless table), then this API always iterates 11226 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 11227 ** 11228 ** xPhraseNext() 11229 ** See xPhraseFirst above. 11230 ** 11231 ** xPhraseFirstColumn() 11232 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 11233 ** and xPhraseNext() APIs described above. The difference is that instead 11234 ** of iterating through all instances of a phrase in the current row, these 11235 ** APIs are used to iterate through the set of columns in the current row 11236 ** that contain one or more instances of a specified phrase. For example: 11237 ** 11238 ** Fts5PhraseIter iter; 11239 ** int iCol; 11240 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 11241 ** iCol>=0; 11242 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 11243 ** ){ 11244 ** // Column iCol contains at least one instance of phrase iPhrase 11245 ** } 11246 ** 11247 ** This API can be quite slow if used with an FTS5 table created with the 11248 ** "detail=none" option. If the FTS5 table is created with either 11249 ** "detail=none" "content=" option (i.e. if it is a contentless table), 11250 ** then this API always iterates through an empty set (all calls to 11251 ** xPhraseFirstColumn() set iCol to -1). 11252 ** 11253 ** The information accessed using this API and its companion 11254 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 11255 ** (or xInst/xInstCount). The chief advantage of this API is that it is 11256 ** significantly more efficient than those alternatives when used with 11257 ** "detail=column" tables. 11258 ** 11259 ** xPhraseNextColumn() 11260 ** See xPhraseFirstColumn above. 11261 */ 11262 struct Fts5ExtensionApi { 11263 int iVersion; /* Currently always set to 3 */ 11264 11265 void *(*xUserData)(Fts5Context*); 11266 11267 int (*xColumnCount)(Fts5Context*); 11268 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 11269 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 11270 11271 int (*xTokenize)(Fts5Context*, 11272 const char *pText, int nText, /* Text to tokenize */ 11273 void *pCtx, /* Context passed to xToken() */ 11274 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 11275 ); 11276 11277 int (*xPhraseCount)(Fts5Context*); 11278 int (*xPhraseSize)(Fts5Context*, int iPhrase); 11279 11280 int (*xInstCount)(Fts5Context*, int *pnInst); 11281 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 11282 11283 sqlite3_int64 (*xRowid)(Fts5Context*); 11284 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 11285 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 11286 11287 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 11288 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 11289 ); 11290 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 11291 void *(*xGetAuxdata)(Fts5Context*, int bClear); 11292 11293 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 11294 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 11295 11296 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 11297 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 11298 }; 11299 11300 /* 11301 ** CUSTOM AUXILIARY FUNCTIONS 11302 *************************************************************************/ 11303 11304 /************************************************************************* 11305 ** CUSTOM TOKENIZERS 11306 ** 11307 ** Applications may also register custom tokenizer types. A tokenizer 11308 ** is registered by providing fts5 with a populated instance of the 11309 ** following structure. All structure methods must be defined, setting 11310 ** any member of the fts5_tokenizer struct to NULL leads to undefined 11311 ** behaviour. The structure methods are expected to function as follows: 11312 ** 11313 ** xCreate: 11314 ** This function is used to allocate and initialize a tokenizer instance. 11315 ** A tokenizer instance is required to actually tokenize text. 11316 ** 11317 ** The first argument passed to this function is a copy of the (void*) 11318 ** pointer provided by the application when the fts5_tokenizer object 11319 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 11320 ** The second and third arguments are an array of nul-terminated strings 11321 ** containing the tokenizer arguments, if any, specified following the 11322 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 11323 ** to create the FTS5 table. 11324 ** 11325 ** The final argument is an output variable. If successful, (*ppOut) 11326 ** should be set to point to the new tokenizer handle and SQLITE_OK 11327 ** returned. If an error occurs, some value other than SQLITE_OK should 11328 ** be returned. In this case, fts5 assumes that the final value of *ppOut 11329 ** is undefined. 11330 ** 11331 ** xDelete: 11332 ** This function is invoked to delete a tokenizer handle previously 11333 ** allocated using xCreate(). Fts5 guarantees that this function will 11334 ** be invoked exactly once for each successful call to xCreate(). 11335 ** 11336 ** xTokenize: 11337 ** This function is expected to tokenize the nText byte string indicated 11338 ** by argument pText. pText may or may not be nul-terminated. The first 11339 ** argument passed to this function is a pointer to an Fts5Tokenizer object 11340 ** returned by an earlier call to xCreate(). 11341 ** 11342 ** The second argument indicates the reason that FTS5 is requesting 11343 ** tokenization of the supplied text. This is always one of the following 11344 ** four values: 11345 ** 11346 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 11347 ** or removed from the FTS table. The tokenizer is being invoked to 11348 ** determine the set of tokens to add to (or delete from) the 11349 ** FTS index. 11350 ** 11351 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 11352 ** against the FTS index. The tokenizer is being called to tokenize 11353 ** a bareword or quoted string specified as part of the query. 11354 ** 11355 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 11356 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 11357 ** followed by a "*" character, indicating that the last token 11358 ** returned by the tokenizer will be treated as a token prefix. 11359 ** 11360 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 11361 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 11362 ** function. Or an fts5_api.xColumnSize() request made by the same 11363 ** on a columnsize=0 database. 11364 ** </ul> 11365 ** 11366 ** For each token in the input string, the supplied callback xToken() must 11367 ** be invoked. The first argument to it should be a copy of the pointer 11368 ** passed as the second argument to xTokenize(). The third and fourth 11369 ** arguments are a pointer to a buffer containing the token text, and the 11370 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 11371 ** of the first byte of and first byte immediately following the text from 11372 ** which the token is derived within the input. 11373 ** 11374 ** The second argument passed to the xToken() callback ("tflags") should 11375 ** normally be set to 0. The exception is if the tokenizer supports 11376 ** synonyms. In this case see the discussion below for details. 11377 ** 11378 ** FTS5 assumes the xToken() callback is invoked for each token in the 11379 ** order that they occur within the input text. 11380 ** 11381 ** If an xToken() callback returns any value other than SQLITE_OK, then 11382 ** the tokenization should be abandoned and the xTokenize() method should 11383 ** immediately return a copy of the xToken() return value. Or, if the 11384 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 11385 ** if an error occurs with the xTokenize() implementation itself, it 11386 ** may abandon the tokenization and return any error code other than 11387 ** SQLITE_OK or SQLITE_DONE. 11388 ** 11389 ** SYNONYM SUPPORT 11390 ** 11391 ** Custom tokenizers may also support synonyms. Consider a case in which a 11392 ** user wishes to query for a phrase such as "first place". Using the 11393 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 11394 ** of "first place" within the document set, but not alternative forms 11395 ** such as "1st place". In some applications, it would be better to match 11396 ** all instances of "first place" or "1st place" regardless of which form 11397 ** the user specified in the MATCH query text. 11398 ** 11399 ** There are several ways to approach this in FTS5: 11400 ** 11401 ** <ol><li> By mapping all synonyms to a single token. In this case, the 11402 ** In the above example, this means that the tokenizer returns the 11403 ** same token for inputs "first" and "1st". Say that token is in 11404 ** fact "first", so that when the user inserts the document "I won 11405 ** 1st place" entries are added to the index for tokens "i", "won", 11406 ** "first" and "place". If the user then queries for '1st + place', 11407 ** the tokenizer substitutes "first" for "1st" and the query works 11408 ** as expected. 11409 ** 11410 ** <li> By adding multiple synonyms for a single term to the FTS index. 11411 ** In this case, when tokenizing query text, the tokenizer may 11412 ** provide multiple synonyms for a single term within the document. 11413 ** FTS5 then queries the index for each synonym individually. For 11414 ** example, faced with the query: 11415 ** 11416 ** <codeblock> 11417 ** ... MATCH 'first place'</codeblock> 11418 ** 11419 ** the tokenizer offers both "1st" and "first" as synonyms for the 11420 ** first token in the MATCH query and FTS5 effectively runs a query 11421 ** similar to: 11422 ** 11423 ** <codeblock> 11424 ** ... MATCH '(first OR 1st) place'</codeblock> 11425 ** 11426 ** except that, for the purposes of auxiliary functions, the query 11427 ** still appears to contain just two phrases - "(first OR 1st)" 11428 ** being treated as a single phrase. 11429 ** 11430 ** <li> By adding multiple synonyms for a single term to the FTS index. 11431 ** Using this method, when tokenizing document text, the tokenizer 11432 ** provides multiple synonyms for each token. So that when a 11433 ** document such as "I won first place" is tokenized, entries are 11434 ** added to the FTS index for "i", "won", "first", "1st" and 11435 ** "place". 11436 ** 11437 ** This way, even if the tokenizer does not provide synonyms 11438 ** when tokenizing query text (it should not - to do would be 11439 ** inefficient), it doesn't matter if the user queries for 11440 ** 'first + place' or '1st + place', as there are entries in the 11441 ** FTS index corresponding to both forms of the first token. 11442 ** </ol> 11443 ** 11444 ** Whether it is parsing document or query text, any call to xToken that 11445 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 11446 ** is considered to supply a synonym for the previous token. For example, 11447 ** when parsing the document "I won first place", a tokenizer that supports 11448 ** synonyms would call xToken() 5 times, as follows: 11449 ** 11450 ** <codeblock> 11451 ** xToken(pCtx, 0, "i", 1, 0, 1); 11452 ** xToken(pCtx, 0, "won", 3, 2, 5); 11453 ** xToken(pCtx, 0, "first", 5, 6, 11); 11454 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 11455 ** xToken(pCtx, 0, "place", 5, 12, 17); 11456 **</codeblock> 11457 ** 11458 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 11459 ** xToken() is called. Multiple synonyms may be specified for a single token 11460 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 11461 ** There is no limit to the number of synonyms that may be provided for a 11462 ** single token. 11463 ** 11464 ** In many cases, method (1) above is the best approach. It does not add 11465 ** extra data to the FTS index or require FTS5 to query for multiple terms, 11466 ** so it is efficient in terms of disk space and query speed. However, it 11467 ** does not support prefix queries very well. If, as suggested above, the 11468 ** token "first" is substituted for "1st" by the tokenizer, then the query: 11469 ** 11470 ** <codeblock> 11471 ** ... MATCH '1s*'</codeblock> 11472 ** 11473 ** will not match documents that contain the token "1st" (as the tokenizer 11474 ** will probably not map "1s" to any prefix of "first"). 11475 ** 11476 ** For full prefix support, method (3) may be preferred. In this case, 11477 ** because the index contains entries for both "first" and "1st", prefix 11478 ** queries such as 'fi*' or '1s*' will match correctly. However, because 11479 ** extra entries are added to the FTS index, this method uses more space 11480 ** within the database. 11481 ** 11482 ** Method (2) offers a midpoint between (1) and (3). Using this method, 11483 ** a query such as '1s*' will match documents that contain the literal 11484 ** token "1st", but not "first" (assuming the tokenizer is not able to 11485 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 11486 ** will match against "1st" and "first". This method does not require 11487 ** extra disk space, as no extra entries are added to the FTS index. 11488 ** On the other hand, it may require more CPU cycles to run MATCH queries, 11489 ** as separate queries of the FTS index are required for each synonym. 11490 ** 11491 ** When using methods (2) or (3), it is important that the tokenizer only 11492 ** provide synonyms when tokenizing document text (method (2)) or query 11493 ** text (method (3)), not both. Doing so will not cause any errors, but is 11494 ** inefficient. 11495 */ 11496 typedef struct Fts5Tokenizer Fts5Tokenizer; 11497 typedef struct fts5_tokenizer fts5_tokenizer; 11498 struct fts5_tokenizer { 11499 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 11500 void (*xDelete)(Fts5Tokenizer*); 11501 int (*xTokenize)(Fts5Tokenizer*, 11502 void *pCtx, 11503 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 11504 const char *pText, int nText, 11505 int (*xToken)( 11506 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 11507 int tflags, /* Mask of FTS5_TOKEN_* flags */ 11508 const char *pToken, /* Pointer to buffer containing token */ 11509 int nToken, /* Size of token in bytes */ 11510 int iStart, /* Byte offset of token within input text */ 11511 int iEnd /* Byte offset of end of token within input text */ 11512 ) 11513 ); 11514 }; 11515 11516 /* Flags that may be passed as the third argument to xTokenize() */ 11517 #define FTS5_TOKENIZE_QUERY 0x0001 11518 #define FTS5_TOKENIZE_PREFIX 0x0002 11519 #define FTS5_TOKENIZE_DOCUMENT 0x0004 11520 #define FTS5_TOKENIZE_AUX 0x0008 11521 11522 /* Flags that may be passed by the tokenizer implementation back to FTS5 11523 ** as the third argument to the supplied xToken callback. */ 11524 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 11525 11526 /* 11527 ** END OF CUSTOM TOKENIZERS 11528 *************************************************************************/ 11529 11530 /************************************************************************* 11531 ** FTS5 EXTENSION REGISTRATION API 11532 */ 11533 typedef struct fts5_api fts5_api; 11534 struct fts5_api { 11535 int iVersion; /* Currently always set to 2 */ 11536 11537 /* Create a new tokenizer */ 11538 int (*xCreateTokenizer)( 11539 fts5_api *pApi, 11540 const char *zName, 11541 void *pContext, 11542 fts5_tokenizer *pTokenizer, 11543 void (*xDestroy)(void*) 11544 ); 11545 11546 /* Find an existing tokenizer */ 11547 int (*xFindTokenizer)( 11548 fts5_api *pApi, 11549 const char *zName, 11550 void **ppContext, 11551 fts5_tokenizer *pTokenizer 11552 ); 11553 11554 /* Create a new auxiliary function */ 11555 int (*xCreateFunction)( 11556 fts5_api *pApi, 11557 const char *zName, 11558 void *pContext, 11559 fts5_extension_function xFunction, 11560 void (*xDestroy)(void*) 11561 ); 11562 }; 11563 11564 /* 11565 ** END OF REGISTRATION API 11566 *************************************************************************/ 11567 11568 #ifdef __cplusplus 11569 } /* end of the 'extern "C"' block */ 11570 #endif 11571 11572 #endif /* _FTS5_H */ 11573 11574 /******** End of fts5.h *********/ 11575 #else // USE_LIBSQLITE3 11576 // If users really want to link against the system sqlite3 we 11577 // need to make this file a noop. 11578 #endif 11579 /* 11580 ** 2014-09-08 11581 ** 11582 ** The author disclaims copyright to this source code. In place of 11583 ** a legal notice, here is a blessing: 11584 ** 11585 ** May you do good and not evil. 11586 ** May you find forgiveness for yourself and forgive others. 11587 ** May you share freely, never taking more than you give. 11588 ** 11589 ************************************************************************* 11590 ** 11591 ** This file contains the application interface definitions for the 11592 ** user-authentication extension feature. 11593 ** 11594 ** To compile with the user-authentication feature, append this file to 11595 ** end of an SQLite amalgamation header file ("sqlite3.h"), then add 11596 ** the SQLITE_USER_AUTHENTICATION compile-time option. See the 11597 ** user-auth.txt file in the same source directory as this file for 11598 ** additional information. 11599 */ 11600 #ifdef SQLITE_USER_AUTHENTICATION 11601 11602 #ifdef __cplusplus 11603 extern "C" { 11604 #endif 11605 11606 /* 11607 ** If a database contains the SQLITE_USER table, then the 11608 ** sqlite3_user_authenticate() interface must be invoked with an 11609 ** appropriate username and password prior to enable read and write 11610 ** access to the database. 11611 ** 11612 ** Return SQLITE_OK on success or SQLITE_ERROR if the username/password 11613 ** combination is incorrect or unknown. 11614 ** 11615 ** If the SQLITE_USER table is not present in the database file, then 11616 ** this interface is a harmless no-op returnning SQLITE_OK. 11617 */ 11618 int sqlite3_user_authenticate( 11619 sqlite3 *db, /* The database connection */ 11620 const char *zUsername, /* Username */ 11621 const char *aPW, /* Password or credentials */ 11622 int nPW /* Number of bytes in aPW[] */ 11623 ); 11624 11625 /* 11626 ** The sqlite3_user_add() interface can be used (by an admin user only) 11627 ** to create a new user. When called on a no-authentication-required 11628 ** database, this routine converts the database into an authentication- 11629 ** required database, automatically makes the added user an 11630 ** administrator, and logs in the current connection as that user. 11631 ** The sqlite3_user_add() interface only works for the "main" database, not 11632 ** for any ATTACH-ed databases. Any call to sqlite3_user_add() by a 11633 ** non-admin user results in an error. 11634 */ 11635 int sqlite3_user_add( 11636 sqlite3 *db, /* Database connection */ 11637 const char *zUsername, /* Username to be added */ 11638 const char *aPW, /* Password or credentials */ 11639 int nPW, /* Number of bytes in aPW[] */ 11640 int isAdmin /* True to give new user admin privilege */ 11641 ); 11642 11643 /* 11644 ** The sqlite3_user_change() interface can be used to change a users 11645 ** login credentials or admin privilege. Any user can change their own 11646 ** login credentials. Only an admin user can change another users login 11647 ** credentials or admin privilege setting. No user may change their own 11648 ** admin privilege setting. 11649 */ 11650 int sqlite3_user_change( 11651 sqlite3 *db, /* Database connection */ 11652 const char *zUsername, /* Username to change */ 11653 const char *aPW, /* New password or credentials */ 11654 int nPW, /* Number of bytes in aPW[] */ 11655 int isAdmin /* Modified admin privilege for the user */ 11656 ); 11657 11658 /* 11659 ** The sqlite3_user_delete() interface can be used (by an admin user only) 11660 ** to delete a user. The currently logged-in user cannot be deleted, 11661 ** which guarantees that there is always an admin user and hence that 11662 ** the database cannot be converted into a no-authentication-required 11663 ** database. 11664 */ 11665 int sqlite3_user_delete( 11666 sqlite3 *db, /* Database connection */ 11667 const char *zUsername /* Username to remove */ 11668 ); 11669 11670 #ifdef __cplusplus 11671 } /* end of the 'extern "C"' block */ 11672 #endif 11673 11674 #endif /* SQLITE_USER_AUTHENTICATION */ 11675