1 /* 2 ** 2001 September 15 3 ** 4 ** The author disclaims copyright to this source code. In place of 5 ** a legal notice, here is a blessing: 6 ** 7 ** May you do good and not evil. 8 ** May you find forgiveness for yourself and forgive others. 9 ** May you share freely, never taking more than you give. 10 ** 11 ************************************************************************* 12 ** This header file defines the interface that the SQLite library 13 ** presents to client programs. If a C-function, structure, datatype, 14 ** or constant definition does not appear in this file, then it is 15 ** not a published API of SQLite, is subject to change without 16 ** notice, and should not be referenced by programs that use SQLite. 17 ** 18 ** Some of the definitions that are in this file are marked as 19 ** "experimental". Experimental interfaces are normally new 20 ** features recently added to SQLite. We do not anticipate changes 21 ** to experimental interfaces but reserve the right to make minor changes 22 ** if experience from use "in the wild" suggest such changes are prudent. 23 ** 24 ** The official C-language API documentation for SQLite is derived 25 ** from comments in this file. This file is the authoritative source 26 ** on how SQLite interfaces are supposed to operate. 27 ** 28 ** The name of this file under configuration management is "sqlite.h.in". 29 ** The makefile makes some minor changes to this file (such as inserting 30 ** the version number) and changes its name to "sqlite3.h" as 31 ** part of the build process. 32 */ 33 #ifndef _SQLITE3_H_ 34 #define _SQLITE3_H_ 35 #include <stdarg.h> /* Needed for the definition of va_list */ 36 37 /* 38 ** Make sure we can call this stuff from C++. 39 */ 40 #ifdef __cplusplus 41 extern "C" { 42 #endif 43 44 45 /* 46 ** Provide the ability to override linkage features of the interface. 47 */ 48 #ifndef SQLITE_EXTERN 49 # define SQLITE_EXTERN extern 50 #endif 51 #ifndef SQLITE_API 52 # define SQLITE_API 53 #endif 54 #ifndef SQLITE_CDECL 55 # define SQLITE_CDECL 56 #endif 57 #ifndef SQLITE_STDCALL 58 # define SQLITE_STDCALL 59 #endif 60 61 /* 62 ** These no-op macros are used in front of interfaces to mark those 63 ** interfaces as either deprecated or experimental. New applications 64 ** should not use deprecated interfaces - they are supported for backwards 65 ** compatibility only. Application writers should be aware that 66 ** experimental interfaces are subject to change in point releases. 67 ** 68 ** These macros used to resolve to various kinds of compiler magic that 69 ** would generate warning messages when they were used. But that 70 ** compiler magic ended up generating such a flurry of bug reports 71 ** that we have taken it all out and gone back to using simple 72 ** noop macros. 73 */ 74 #define SQLITE_DEPRECATED 75 #define SQLITE_EXPERIMENTAL 76 77 /* 78 ** Ensure these symbols were not defined by some previous header file. 79 */ 80 #ifdef SQLITE_VERSION 81 # undef SQLITE_VERSION 82 #endif 83 #ifdef SQLITE_VERSION_NUMBER 84 # undef SQLITE_VERSION_NUMBER 85 #endif 86 87 /* 88 ** CAPI3REF: Compile-Time Library Version Numbers 89 ** 90 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 91 ** evaluates to a string literal that is the SQLite version in the 92 ** format "X.Y.Z" where X is the major version number (always 3 for 93 ** SQLite3) and Y is the minor version number and Z is the release number.)^ 94 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 95 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 96 ** numbers used in [SQLITE_VERSION].)^ 97 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 98 ** be larger than the release from which it is derived. Either Y will 99 ** be held constant and Z will be incremented or else Y will be incremented 100 ** and Z will be reset to zero. 101 ** 102 ** Since version 3.6.18, SQLite source code has been stored in the 103 ** <a href="http://www.fossil-scm.org/">Fossil configuration management 104 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 105 ** a string which identifies a particular check-in of SQLite 106 ** within its configuration management system. ^The SQLITE_SOURCE_ID 107 ** string contains the date and time of the check-in (UTC) and an SHA1 108 ** hash of the entire source tree. 109 ** 110 ** See also: [sqlite3_libversion()], 111 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 112 ** [sqlite_version()] and [sqlite_source_id()]. 113 */ 114 #define SQLITE_VERSION "3.10.0" 115 #define SQLITE_VERSION_NUMBER 3010000 116 #define SQLITE_SOURCE_ID "2016-01-06 11:01:07 fd0a50f0797d154fefff724624f00548b5320566" 117 118 /* 119 ** CAPI3REF: Run-Time Library Version Numbers 120 ** KEYWORDS: sqlite3_version, sqlite3_sourceid 121 ** 122 ** These interfaces provide the same information as the [SQLITE_VERSION], 123 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 124 ** but are associated with the library instead of the header file. ^(Cautious 125 ** programmers might include assert() statements in their application to 126 ** verify that values returned by these interfaces match the macros in 127 ** the header, and thus ensure that the application is 128 ** compiled with matching library and header files. 129 ** 130 ** <blockquote><pre> 131 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 132 ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 133 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 134 ** </pre></blockquote>)^ 135 ** 136 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 137 ** macro. ^The sqlite3_libversion() function returns a pointer to the 138 ** to the sqlite3_version[] string constant. The sqlite3_libversion() 139 ** function is provided for use in DLLs since DLL users usually do not have 140 ** direct access to string constants within the DLL. ^The 141 ** sqlite3_libversion_number() function returns an integer equal to 142 ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 143 ** a pointer to a string constant whose value is the same as the 144 ** [SQLITE_SOURCE_ID] C preprocessor macro. 145 ** 146 ** See also: [sqlite_version()] and [sqlite_source_id()]. 147 */ 148 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 149 SQLITE_API const char *SQLITE_STDCALL sqlite3_libversion(void); 150 SQLITE_API const char *SQLITE_STDCALL sqlite3_sourceid(void); 151 SQLITE_API int SQLITE_STDCALL sqlite3_libversion_number(void); 152 153 /* 154 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 155 ** 156 ** ^The sqlite3_compileoption_used() function returns 0 or 1 157 ** indicating whether the specified option was defined at 158 ** compile time. ^The SQLITE_ prefix may be omitted from the 159 ** option name passed to sqlite3_compileoption_used(). 160 ** 161 ** ^The sqlite3_compileoption_get() function allows iterating 162 ** over the list of options that were defined at compile time by 163 ** returning the N-th compile time option string. ^If N is out of range, 164 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 165 ** prefix is omitted from any strings returned by 166 ** sqlite3_compileoption_get(). 167 ** 168 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 169 ** and sqlite3_compileoption_get() may be omitted by specifying the 170 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 171 ** 172 ** See also: SQL functions [sqlite_compileoption_used()] and 173 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 174 */ 175 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 176 SQLITE_API int SQLITE_STDCALL sqlite3_compileoption_used(const char *zOptName); 177 SQLITE_API const char *SQLITE_STDCALL sqlite3_compileoption_get(int N); 178 #endif 179 180 /* 181 ** CAPI3REF: Test To See If The Library Is Threadsafe 182 ** 183 ** ^The sqlite3_threadsafe() function returns zero if and only if 184 ** SQLite was compiled with mutexing code omitted due to the 185 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 186 ** 187 ** SQLite can be compiled with or without mutexes. When 188 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 189 ** are enabled and SQLite is threadsafe. When the 190 ** [SQLITE_THREADSAFE] macro is 0, 191 ** the mutexes are omitted. Without the mutexes, it is not safe 192 ** to use SQLite concurrently from more than one thread. 193 ** 194 ** Enabling mutexes incurs a measurable performance penalty. 195 ** So if speed is of utmost importance, it makes sense to disable 196 ** the mutexes. But for maximum safety, mutexes should be enabled. 197 ** ^The default behavior is for mutexes to be enabled. 198 ** 199 ** This interface can be used by an application to make sure that the 200 ** version of SQLite that it is linking against was compiled with 201 ** the desired setting of the [SQLITE_THREADSAFE] macro. 202 ** 203 ** This interface only reports on the compile-time mutex setting 204 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 205 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 206 ** can be fully or partially disabled using a call to [sqlite3_config()] 207 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 208 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 209 ** sqlite3_threadsafe() function shows only the compile-time setting of 210 ** thread safety, not any run-time changes to that setting made by 211 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 212 ** is unchanged by calls to sqlite3_config().)^ 213 ** 214 ** See the [threading mode] documentation for additional information. 215 */ 216 SQLITE_API int SQLITE_STDCALL sqlite3_threadsafe(void); 217 218 /* 219 ** CAPI3REF: Database Connection Handle 220 ** KEYWORDS: {database connection} {database connections} 221 ** 222 ** Each open SQLite database is represented by a pointer to an instance of 223 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 224 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 225 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 226 ** and [sqlite3_close_v2()] are its destructors. There are many other 227 ** interfaces (such as 228 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 229 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 230 ** sqlite3 object. 231 */ 232 typedef struct sqlite3 sqlite3; 233 234 /* 235 ** CAPI3REF: 64-Bit Integer Types 236 ** KEYWORDS: sqlite_int64 sqlite_uint64 237 ** 238 ** Because there is no cross-platform way to specify 64-bit integer types 239 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 240 ** 241 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 242 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 243 ** compatibility only. 244 ** 245 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 246 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 247 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 248 ** between 0 and +18446744073709551615 inclusive. 249 */ 250 #ifdef SQLITE_INT64_TYPE 251 typedef SQLITE_INT64_TYPE sqlite_int64; 252 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 253 #elif defined(_MSC_VER) || defined(__BORLANDC__) 254 typedef __int64 sqlite_int64; 255 typedef unsigned __int64 sqlite_uint64; 256 #else 257 typedef long long int sqlite_int64; 258 typedef unsigned long long int sqlite_uint64; 259 #endif 260 typedef sqlite_int64 sqlite3_int64; 261 typedef sqlite_uint64 sqlite3_uint64; 262 263 /* 264 ** If compiling for a processor that lacks floating point support, 265 ** substitute integer for floating-point. 266 */ 267 #ifdef SQLITE_OMIT_FLOATING_POINT 268 # define double sqlite3_int64 269 #endif 270 271 /* 272 ** CAPI3REF: Closing A Database Connection 273 ** DESTRUCTOR: sqlite3 274 ** 275 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 276 ** for the [sqlite3] object. 277 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 278 ** the [sqlite3] object is successfully destroyed and all associated 279 ** resources are deallocated. 280 ** 281 ** ^If the database connection is associated with unfinalized prepared 282 ** statements or unfinished sqlite3_backup objects then sqlite3_close() 283 ** will leave the database connection open and return [SQLITE_BUSY]. 284 ** ^If sqlite3_close_v2() is called with unfinalized prepared statements 285 ** and/or unfinished sqlite3_backups, then the database connection becomes 286 ** an unusable "zombie" which will automatically be deallocated when the 287 ** last prepared statement is finalized or the last sqlite3_backup is 288 ** finished. The sqlite3_close_v2() interface is intended for use with 289 ** host languages that are garbage collected, and where the order in which 290 ** destructors are called is arbitrary. 291 ** 292 ** Applications should [sqlite3_finalize | finalize] all [prepared statements], 293 ** [sqlite3_blob_close | close] all [BLOB handles], and 294 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 295 ** with the [sqlite3] object prior to attempting to close the object. ^If 296 ** sqlite3_close_v2() is called on a [database connection] that still has 297 ** outstanding [prepared statements], [BLOB handles], and/or 298 ** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 299 ** of resources is deferred until all [prepared statements], [BLOB handles], 300 ** and [sqlite3_backup] objects are also destroyed. 301 ** 302 ** ^If an [sqlite3] object is destroyed while a transaction is open, 303 ** the transaction is automatically rolled back. 304 ** 305 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 306 ** must be either a NULL 307 ** pointer or an [sqlite3] object pointer obtained 308 ** from [sqlite3_open()], [sqlite3_open16()], or 309 ** [sqlite3_open_v2()], and not previously closed. 310 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 311 ** argument is a harmless no-op. 312 */ 313 SQLITE_API int SQLITE_STDCALL sqlite3_close(sqlite3*); 314 SQLITE_API int SQLITE_STDCALL sqlite3_close_v2(sqlite3*); 315 316 /* 317 ** The type for a callback function. 318 ** This is legacy and deprecated. It is included for historical 319 ** compatibility and is not documented. 320 */ 321 typedef int (*sqlite3_callback)(void*,int,char**, char**); 322 323 /* 324 ** CAPI3REF: One-Step Query Execution Interface 325 ** METHOD: sqlite3 326 ** 327 ** The sqlite3_exec() interface is a convenience wrapper around 328 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 329 ** that allows an application to run multiple statements of SQL 330 ** without having to use a lot of C code. 331 ** 332 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 333 ** semicolon-separate SQL statements passed into its 2nd argument, 334 ** in the context of the [database connection] passed in as its 1st 335 ** argument. ^If the callback function of the 3rd argument to 336 ** sqlite3_exec() is not NULL, then it is invoked for each result row 337 ** coming out of the evaluated SQL statements. ^The 4th argument to 338 ** sqlite3_exec() is relayed through to the 1st argument of each 339 ** callback invocation. ^If the callback pointer to sqlite3_exec() 340 ** is NULL, then no callback is ever invoked and result rows are 341 ** ignored. 342 ** 343 ** ^If an error occurs while evaluating the SQL statements passed into 344 ** sqlite3_exec(), then execution of the current statement stops and 345 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 346 ** is not NULL then any error message is written into memory obtained 347 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 348 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 349 ** on error message strings returned through the 5th parameter of 350 ** of sqlite3_exec() after the error message string is no longer needed. 351 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 352 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 353 ** NULL before returning. 354 ** 355 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 356 ** routine returns SQLITE_ABORT without invoking the callback again and 357 ** without running any subsequent SQL statements. 358 ** 359 ** ^The 2nd argument to the sqlite3_exec() callback function is the 360 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 361 ** callback is an array of pointers to strings obtained as if from 362 ** [sqlite3_column_text()], one for each column. ^If an element of a 363 ** result row is NULL then the corresponding string pointer for the 364 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 365 ** sqlite3_exec() callback is an array of pointers to strings where each 366 ** entry represents the name of corresponding result column as obtained 367 ** from [sqlite3_column_name()]. 368 ** 369 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 370 ** to an empty string, or a pointer that contains only whitespace and/or 371 ** SQL comments, then no SQL statements are evaluated and the database 372 ** is not changed. 373 ** 374 ** Restrictions: 375 ** 376 ** <ul> 377 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 378 ** is a valid and open [database connection]. 379 ** <li> The application must not close the [database connection] specified by 380 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 381 ** <li> The application must not modify the SQL statement text passed into 382 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 383 ** </ul> 384 */ 385 SQLITE_API int SQLITE_STDCALL sqlite3_exec( 386 sqlite3*, /* An open database */ 387 const char *sql, /* SQL to be evaluated */ 388 int (*callback)(void*,int,char**,char**), /* Callback function */ 389 void *, /* 1st argument to callback */ 390 char **errmsg /* Error msg written here */ 391 ); 392 393 /* 394 ** CAPI3REF: Result Codes 395 ** KEYWORDS: {result code definitions} 396 ** 397 ** Many SQLite functions return an integer result code from the set shown 398 ** here in order to indicate success or failure. 399 ** 400 ** New error codes may be added in future versions of SQLite. 401 ** 402 ** See also: [extended result code definitions] 403 */ 404 #define SQLITE_OK 0 /* Successful result */ 405 /* beginning-of-error-codes */ 406 #define SQLITE_ERROR 1 /* SQL error or missing database */ 407 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 408 #define SQLITE_PERM 3 /* Access permission denied */ 409 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 410 #define SQLITE_BUSY 5 /* The database file is locked */ 411 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 412 #define SQLITE_NOMEM 7 /* A malloc() failed */ 413 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 414 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 415 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 416 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 417 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 418 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 419 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 420 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 421 #define SQLITE_EMPTY 16 /* Database is empty */ 422 #define SQLITE_SCHEMA 17 /* The database schema changed */ 423 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 424 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 425 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 426 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 427 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 428 #define SQLITE_AUTH 23 /* Authorization denied */ 429 #define SQLITE_FORMAT 24 /* Auxiliary database format error */ 430 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 431 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 432 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 433 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 434 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 435 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 436 /* end-of-error-codes */ 437 438 /* 439 ** CAPI3REF: Extended Result Codes 440 ** KEYWORDS: {extended result code definitions} 441 ** 442 ** In its default configuration, SQLite API routines return one of 30 integer 443 ** [result codes]. However, experience has shown that many of 444 ** these result codes are too coarse-grained. They do not provide as 445 ** much information about problems as programmers might like. In an effort to 446 ** address this, newer versions of SQLite (version 3.3.8 and later) include 447 ** support for additional result codes that provide more detailed information 448 ** about errors. These [extended result codes] are enabled or disabled 449 ** on a per database connection basis using the 450 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 451 ** the most recent error can be obtained using 452 ** [sqlite3_extended_errcode()]. 453 */ 454 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 455 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 456 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 457 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 458 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 459 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 460 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 461 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 462 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 463 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 464 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 465 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 466 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 467 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 468 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 469 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 470 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 471 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 472 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 473 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 474 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 475 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 476 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 477 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 478 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 479 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 480 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 481 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 482 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 483 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 484 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 485 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 486 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 487 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 488 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 489 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 490 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 491 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 492 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 493 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 494 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 495 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 496 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 497 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 498 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 499 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 500 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 501 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 502 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 503 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 504 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 505 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 506 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 507 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 508 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 509 510 /* 511 ** CAPI3REF: Flags For File Open Operations 512 ** 513 ** These bit values are intended for use in the 514 ** 3rd parameter to the [sqlite3_open_v2()] interface and 515 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 516 */ 517 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 518 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 519 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 520 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 521 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 522 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 523 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 524 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 525 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 526 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 527 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 528 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 529 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 530 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 531 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 532 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 533 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 534 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 535 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 536 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 537 538 /* Reserved: 0x00F00000 */ 539 540 /* 541 ** CAPI3REF: Device Characteristics 542 ** 543 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 544 ** object returns an integer which is a vector of these 545 ** bit values expressing I/O characteristics of the mass storage 546 ** device that holds the file that the [sqlite3_io_methods] 547 ** refers to. 548 ** 549 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 550 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 551 ** mean that writes of blocks that are nnn bytes in size and 552 ** are aligned to an address which is an integer multiple of 553 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 554 ** that when data is appended to a file, the data is appended 555 ** first then the size of the file is extended, never the other 556 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 557 ** information is written to disk in the same order as calls 558 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 559 ** after reboot following a crash or power loss, the only bytes in a 560 ** file that were written at the application level might have changed 561 ** and that adjacent bytes, even bytes within the same sector are 562 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 563 ** flag indicate that a file cannot be deleted when open. The 564 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 565 ** read-only media and cannot be changed even by processes with 566 ** elevated privileges. 567 */ 568 #define SQLITE_IOCAP_ATOMIC 0x00000001 569 #define SQLITE_IOCAP_ATOMIC512 0x00000002 570 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 571 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 572 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 573 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 574 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 575 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 576 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 577 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 578 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 579 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 580 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 581 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 582 583 /* 584 ** CAPI3REF: File Locking Levels 585 ** 586 ** SQLite uses one of these integer values as the second 587 ** argument to calls it makes to the xLock() and xUnlock() methods 588 ** of an [sqlite3_io_methods] object. 589 */ 590 #define SQLITE_LOCK_NONE 0 591 #define SQLITE_LOCK_SHARED 1 592 #define SQLITE_LOCK_RESERVED 2 593 #define SQLITE_LOCK_PENDING 3 594 #define SQLITE_LOCK_EXCLUSIVE 4 595 596 /* 597 ** CAPI3REF: Synchronization Type Flags 598 ** 599 ** When SQLite invokes the xSync() method of an 600 ** [sqlite3_io_methods] object it uses a combination of 601 ** these integer values as the second argument. 602 ** 603 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 604 ** sync operation only needs to flush data to mass storage. Inode 605 ** information need not be flushed. If the lower four bits of the flag 606 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 607 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 608 ** to use Mac OS X style fullsync instead of fsync(). 609 ** 610 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 611 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 612 ** settings. The [synchronous pragma] determines when calls to the 613 ** xSync VFS method occur and applies uniformly across all platforms. 614 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 615 ** energetic or rigorous or forceful the sync operations are and 616 ** only make a difference on Mac OSX for the default SQLite code. 617 ** (Third-party VFS implementations might also make the distinction 618 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 619 ** operating systems natively supported by SQLite, only Mac OSX 620 ** cares about the difference.) 621 */ 622 #define SQLITE_SYNC_NORMAL 0x00002 623 #define SQLITE_SYNC_FULL 0x00003 624 #define SQLITE_SYNC_DATAONLY 0x00010 625 626 /* 627 ** CAPI3REF: OS Interface Open File Handle 628 ** 629 ** An [sqlite3_file] object represents an open file in the 630 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 631 ** implementations will 632 ** want to subclass this object by appending additional fields 633 ** for their own use. The pMethods entry is a pointer to an 634 ** [sqlite3_io_methods] object that defines methods for performing 635 ** I/O operations on the open file. 636 */ 637 typedef struct sqlite3_file sqlite3_file; 638 struct sqlite3_file { 639 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 640 }; 641 642 /* 643 ** CAPI3REF: OS Interface File Virtual Methods Object 644 ** 645 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 646 ** [sqlite3_file] object (or, more commonly, a subclass of the 647 ** [sqlite3_file] object) with a pointer to an instance of this object. 648 ** This object defines the methods used to perform various operations 649 ** against the open file represented by the [sqlite3_file] object. 650 ** 651 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 652 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 653 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 654 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 655 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 656 ** to NULL. 657 ** 658 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 659 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 660 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 661 ** flag may be ORed in to indicate that only the data of the file 662 ** and not its inode needs to be synced. 663 ** 664 ** The integer values to xLock() and xUnlock() are one of 665 ** <ul> 666 ** <li> [SQLITE_LOCK_NONE], 667 ** <li> [SQLITE_LOCK_SHARED], 668 ** <li> [SQLITE_LOCK_RESERVED], 669 ** <li> [SQLITE_LOCK_PENDING], or 670 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 671 ** </ul> 672 ** xLock() increases the lock. xUnlock() decreases the lock. 673 ** The xCheckReservedLock() method checks whether any database connection, 674 ** either in this process or in some other process, is holding a RESERVED, 675 ** PENDING, or EXCLUSIVE lock on the file. It returns true 676 ** if such a lock exists and false otherwise. 677 ** 678 ** The xFileControl() method is a generic interface that allows custom 679 ** VFS implementations to directly control an open file using the 680 ** [sqlite3_file_control()] interface. The second "op" argument is an 681 ** integer opcode. The third argument is a generic pointer intended to 682 ** point to a structure that may contain arguments or space in which to 683 ** write return values. Potential uses for xFileControl() might be 684 ** functions to enable blocking locks with timeouts, to change the 685 ** locking strategy (for example to use dot-file locks), to inquire 686 ** about the status of a lock, or to break stale locks. The SQLite 687 ** core reserves all opcodes less than 100 for its own use. 688 ** A [file control opcodes | list of opcodes] less than 100 is available. 689 ** Applications that define a custom xFileControl method should use opcodes 690 ** greater than 100 to avoid conflicts. VFS implementations should 691 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 692 ** recognize. 693 ** 694 ** The xSectorSize() method returns the sector size of the 695 ** device that underlies the file. The sector size is the 696 ** minimum write that can be performed without disturbing 697 ** other bytes in the file. The xDeviceCharacteristics() 698 ** method returns a bit vector describing behaviors of the 699 ** underlying device: 700 ** 701 ** <ul> 702 ** <li> [SQLITE_IOCAP_ATOMIC] 703 ** <li> [SQLITE_IOCAP_ATOMIC512] 704 ** <li> [SQLITE_IOCAP_ATOMIC1K] 705 ** <li> [SQLITE_IOCAP_ATOMIC2K] 706 ** <li> [SQLITE_IOCAP_ATOMIC4K] 707 ** <li> [SQLITE_IOCAP_ATOMIC8K] 708 ** <li> [SQLITE_IOCAP_ATOMIC16K] 709 ** <li> [SQLITE_IOCAP_ATOMIC32K] 710 ** <li> [SQLITE_IOCAP_ATOMIC64K] 711 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 712 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 713 ** </ul> 714 ** 715 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 716 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 717 ** mean that writes of blocks that are nnn bytes in size and 718 ** are aligned to an address which is an integer multiple of 719 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 720 ** that when data is appended to a file, the data is appended 721 ** first then the size of the file is extended, never the other 722 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 723 ** information is written to disk in the same order as calls 724 ** to xWrite(). 725 ** 726 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 727 ** in the unread portions of the buffer with zeros. A VFS that 728 ** fails to zero-fill short reads might seem to work. However, 729 ** failure to zero-fill short reads will eventually lead to 730 ** database corruption. 731 */ 732 typedef struct sqlite3_io_methods sqlite3_io_methods; 733 struct sqlite3_io_methods { 734 int iVersion; 735 int (*xClose)(sqlite3_file*); 736 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 737 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 738 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 739 int (*xSync)(sqlite3_file*, int flags); 740 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 741 int (*xLock)(sqlite3_file*, int); 742 int (*xUnlock)(sqlite3_file*, int); 743 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 744 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 745 int (*xSectorSize)(sqlite3_file*); 746 int (*xDeviceCharacteristics)(sqlite3_file*); 747 /* Methods above are valid for version 1 */ 748 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 749 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 750 void (*xShmBarrier)(sqlite3_file*); 751 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 752 /* Methods above are valid for version 2 */ 753 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 754 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 755 /* Methods above are valid for version 3 */ 756 /* Additional methods may be added in future releases */ 757 }; 758 759 /* 760 ** CAPI3REF: Standard File Control Opcodes 761 ** KEYWORDS: {file control opcodes} {file control opcode} 762 ** 763 ** These integer constants are opcodes for the xFileControl method 764 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 765 ** interface. 766 ** 767 ** <ul> 768 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 769 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 770 ** opcode causes the xFileControl method to write the current state of 771 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 772 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 773 ** into an integer that the pArg argument points to. This capability 774 ** is used during testing and is only available when the SQLITE_TEST 775 ** compile-time option is used. 776 ** 777 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 778 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 779 ** layer a hint of how large the database file will grow to be during the 780 ** current transaction. This hint is not guaranteed to be accurate but it 781 ** is often close. The underlying VFS might choose to preallocate database 782 ** file space based on this hint in order to help writes to the database 783 ** file run faster. 784 ** 785 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 786 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 787 ** extends and truncates the database file in chunks of a size specified 788 ** by the user. The fourth argument to [sqlite3_file_control()] should 789 ** point to an integer (type int) containing the new chunk-size to use 790 ** for the nominated database. Allocating database file space in large 791 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 792 ** improve performance on some systems. 793 ** 794 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 795 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 796 ** to the [sqlite3_file] object associated with a particular database 797 ** connection. See the [sqlite3_file_control()] documentation for 798 ** additional information. 799 ** 800 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 801 ** No longer in use. 802 ** 803 ** <li>[[SQLITE_FCNTL_SYNC]] 804 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 805 ** sent to the VFS immediately before the xSync method is invoked on a 806 ** database file descriptor. Or, if the xSync method is not invoked 807 ** because the user has configured SQLite with 808 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 809 ** of the xSync method. In most cases, the pointer argument passed with 810 ** this file-control is NULL. However, if the database file is being synced 811 ** as part of a multi-database commit, the argument points to a nul-terminated 812 ** string containing the transactions master-journal file name. VFSes that 813 ** do not need this signal should silently ignore this opcode. Applications 814 ** should not call [sqlite3_file_control()] with this opcode as doing so may 815 ** disrupt the operation of the specialized VFSes that do require it. 816 ** 817 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 818 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 819 ** and sent to the VFS after a transaction has been committed immediately 820 ** but before the database is unlocked. VFSes that do not need this signal 821 ** should silently ignore this opcode. Applications should not call 822 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 823 ** operation of the specialized VFSes that do require it. 824 ** 825 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 826 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 827 ** retry counts and intervals for certain disk I/O operations for the 828 ** windows [VFS] in order to provide robustness in the presence of 829 ** anti-virus programs. By default, the windows VFS will retry file read, 830 ** file write, and file delete operations up to 10 times, with a delay 831 ** of 25 milliseconds before the first retry and with the delay increasing 832 ** by an additional 25 milliseconds with each subsequent retry. This 833 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 834 ** to be adjusted. The values are changed for all database connections 835 ** within the same process. The argument is a pointer to an array of two 836 ** integers where the first integer i the new retry count and the second 837 ** integer is the delay. If either integer is negative, then the setting 838 ** is not changed but instead the prior value of that setting is written 839 ** into the array entry, allowing the current retry settings to be 840 ** interrogated. The zDbName parameter is ignored. 841 ** 842 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 843 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 844 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 845 ** write ahead log and shared memory files used for transaction control 846 ** are automatically deleted when the latest connection to the database 847 ** closes. Setting persistent WAL mode causes those files to persist after 848 ** close. Persisting the files is useful when other processes that do not 849 ** have write permission on the directory containing the database file want 850 ** to read the database file, as the WAL and shared memory files must exist 851 ** in order for the database to be readable. The fourth parameter to 852 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 853 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 854 ** WAL mode. If the integer is -1, then it is overwritten with the current 855 ** WAL persistence setting. 856 ** 857 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 858 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 859 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 860 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 861 ** xDeviceCharacteristics methods. The fourth parameter to 862 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 863 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 864 ** mode. If the integer is -1, then it is overwritten with the current 865 ** zero-damage mode setting. 866 ** 867 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 868 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 869 ** a write transaction to indicate that, unless it is rolled back for some 870 ** reason, the entire database file will be overwritten by the current 871 ** transaction. This is used by VACUUM operations. 872 ** 873 ** <li>[[SQLITE_FCNTL_VFSNAME]] 874 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 875 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 876 ** final bottom-level VFS are written into memory obtained from 877 ** [sqlite3_malloc()] and the result is stored in the char* variable 878 ** that the fourth parameter of [sqlite3_file_control()] points to. 879 ** The caller is responsible for freeing the memory when done. As with 880 ** all file-control actions, there is no guarantee that this will actually 881 ** do anything. Callers should initialize the char* variable to a NULL 882 ** pointer in case this file-control is not implemented. This file-control 883 ** is intended for diagnostic use only. 884 ** 885 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 886 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 887 ** [VFSes] currently in use. ^(The argument X in 888 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 889 ** of type "[sqlite3_vfs] **". This opcodes will set *X 890 ** to a pointer to the top-level VFS.)^ 891 ** ^When there are multiple VFS shims in the stack, this opcode finds the 892 ** upper-most shim only. 893 ** 894 ** <li>[[SQLITE_FCNTL_PRAGMA]] 895 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 896 ** file control is sent to the open [sqlite3_file] object corresponding 897 ** to the database file to which the pragma statement refers. ^The argument 898 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 899 ** pointers to strings (char**) in which the second element of the array 900 ** is the name of the pragma and the third element is the argument to the 901 ** pragma or NULL if the pragma has no argument. ^The handler for an 902 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 903 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 904 ** or the equivalent and that string will become the result of the pragma or 905 ** the error message if the pragma fails. ^If the 906 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 907 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 908 ** file control returns [SQLITE_OK], then the parser assumes that the 909 ** VFS has handled the PRAGMA itself and the parser generates a no-op 910 ** prepared statement if result string is NULL, or that returns a copy 911 ** of the result string if the string is non-NULL. 912 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 913 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 914 ** that the VFS encountered an error while handling the [PRAGMA] and the 915 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 916 ** file control occurs at the beginning of pragma statement analysis and so 917 ** it is able to override built-in [PRAGMA] statements. 918 ** 919 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 920 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 921 ** file-control may be invoked by SQLite on the database file handle 922 ** shortly after it is opened in order to provide a custom VFS with access 923 ** to the connections busy-handler callback. The argument is of type (void **) 924 ** - an array of two (void *) values. The first (void *) actually points 925 ** to a function of type (int (*)(void *)). In order to invoke the connections 926 ** busy-handler, this function should be invoked with the second (void *) in 927 ** the array as the only argument. If it returns non-zero, then the operation 928 ** should be retried. If it returns zero, the custom VFS should abandon the 929 ** current operation. 930 ** 931 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 932 ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 933 ** to have SQLite generate a 934 ** temporary filename using the same algorithm that is followed to generate 935 ** temporary filenames for TEMP tables and other internal uses. The 936 ** argument should be a char** which will be filled with the filename 937 ** written into memory obtained from [sqlite3_malloc()]. The caller should 938 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 939 ** 940 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 941 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 942 ** maximum number of bytes that will be used for memory-mapped I/O. 943 ** The argument is a pointer to a value of type sqlite3_int64 that 944 ** is an advisory maximum number of bytes in the file to memory map. The 945 ** pointer is overwritten with the old value. The limit is not changed if 946 ** the value originally pointed to is negative, and so the current limit 947 ** can be queried by passing in a pointer to a negative number. This 948 ** file-control is used internally to implement [PRAGMA mmap_size]. 949 ** 950 ** <li>[[SQLITE_FCNTL_TRACE]] 951 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 952 ** to the VFS about what the higher layers of the SQLite stack are doing. 953 ** This file control is used by some VFS activity tracing [shims]. 954 ** The argument is a zero-terminated string. Higher layers in the 955 ** SQLite stack may generate instances of this file control if 956 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 957 ** 958 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 959 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 960 ** pointer to an integer and it writes a boolean into that integer depending 961 ** on whether or not the file has been renamed, moved, or deleted since it 962 ** was first opened. 963 ** 964 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 965 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 966 ** opcode causes the xFileControl method to swap the file handle with the one 967 ** pointed to by the pArg argument. This capability is used during testing 968 ** and only needs to be supported when SQLITE_TEST is defined. 969 ** 970 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 971 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 972 ** be advantageous to block on the next WAL lock if the lock is not immediately 973 ** available. The WAL subsystem issues this signal during rare 974 ** circumstances in order to fix a problem with priority inversion. 975 ** Applications should <em>not</em> use this file-control. 976 ** 977 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 978 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 979 ** VFS should return SQLITE_NOTFOUND for this opcode. 980 ** 981 ** <li>[[SQLITE_FCNTL_RBU]] 982 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 983 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 984 ** this opcode. 985 ** </ul> 986 */ 987 #define SQLITE_FCNTL_LOCKSTATE 1 988 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 989 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 990 #define SQLITE_FCNTL_LAST_ERRNO 4 991 #define SQLITE_FCNTL_SIZE_HINT 5 992 #define SQLITE_FCNTL_CHUNK_SIZE 6 993 #define SQLITE_FCNTL_FILE_POINTER 7 994 #define SQLITE_FCNTL_SYNC_OMITTED 8 995 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 996 #define SQLITE_FCNTL_PERSIST_WAL 10 997 #define SQLITE_FCNTL_OVERWRITE 11 998 #define SQLITE_FCNTL_VFSNAME 12 999 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1000 #define SQLITE_FCNTL_PRAGMA 14 1001 #define SQLITE_FCNTL_BUSYHANDLER 15 1002 #define SQLITE_FCNTL_TEMPFILENAME 16 1003 #define SQLITE_FCNTL_MMAP_SIZE 18 1004 #define SQLITE_FCNTL_TRACE 19 1005 #define SQLITE_FCNTL_HAS_MOVED 20 1006 #define SQLITE_FCNTL_SYNC 21 1007 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1008 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1009 #define SQLITE_FCNTL_WAL_BLOCK 24 1010 #define SQLITE_FCNTL_ZIPVFS 25 1011 #define SQLITE_FCNTL_RBU 26 1012 #define SQLITE_FCNTL_VFS_POINTER 27 1013 1014 /* deprecated names */ 1015 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1016 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1017 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1018 1019 1020 /* 1021 ** CAPI3REF: Mutex Handle 1022 ** 1023 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1024 ** abstract type for a mutex object. The SQLite core never looks 1025 ** at the internal representation of an [sqlite3_mutex]. It only 1026 ** deals with pointers to the [sqlite3_mutex] object. 1027 ** 1028 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1029 */ 1030 typedef struct sqlite3_mutex sqlite3_mutex; 1031 1032 /* 1033 ** CAPI3REF: OS Interface Object 1034 ** 1035 ** An instance of the sqlite3_vfs object defines the interface between 1036 ** the SQLite core and the underlying operating system. The "vfs" 1037 ** in the name of the object stands for "virtual file system". See 1038 ** the [VFS | VFS documentation] for further information. 1039 ** 1040 ** The value of the iVersion field is initially 1 but may be larger in 1041 ** future versions of SQLite. Additional fields may be appended to this 1042 ** object when the iVersion value is increased. Note that the structure 1043 ** of the sqlite3_vfs object changes in the transaction between 1044 ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 1045 ** modified. 1046 ** 1047 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1048 ** structure used by this VFS. mxPathname is the maximum length of 1049 ** a pathname in this VFS. 1050 ** 1051 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1052 ** the pNext pointer. The [sqlite3_vfs_register()] 1053 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1054 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1055 ** searches the list. Neither the application code nor the VFS 1056 ** implementation should use the pNext pointer. 1057 ** 1058 ** The pNext field is the only field in the sqlite3_vfs 1059 ** structure that SQLite will ever modify. SQLite will only access 1060 ** or modify this field while holding a particular static mutex. 1061 ** The application should never modify anything within the sqlite3_vfs 1062 ** object once the object has been registered. 1063 ** 1064 ** The zName field holds the name of the VFS module. The name must 1065 ** be unique across all VFS modules. 1066 ** 1067 ** [[sqlite3_vfs.xOpen]] 1068 ** ^SQLite guarantees that the zFilename parameter to xOpen 1069 ** is either a NULL pointer or string obtained 1070 ** from xFullPathname() with an optional suffix added. 1071 ** ^If a suffix is added to the zFilename parameter, it will 1072 ** consist of a single "-" character followed by no more than 1073 ** 11 alphanumeric and/or "-" characters. 1074 ** ^SQLite further guarantees that 1075 ** the string will be valid and unchanged until xClose() is 1076 ** called. Because of the previous sentence, 1077 ** the [sqlite3_file] can safely store a pointer to the 1078 ** filename if it needs to remember the filename for some reason. 1079 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1080 ** must invent its own temporary name for the file. ^Whenever the 1081 ** xFilename parameter is NULL it will also be the case that the 1082 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1083 ** 1084 ** The flags argument to xOpen() includes all bits set in 1085 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1086 ** or [sqlite3_open16()] is used, then flags includes at least 1087 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1088 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1089 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1090 ** 1091 ** ^(SQLite will also add one of the following flags to the xOpen() 1092 ** call, depending on the object being opened: 1093 ** 1094 ** <ul> 1095 ** <li> [SQLITE_OPEN_MAIN_DB] 1096 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1097 ** <li> [SQLITE_OPEN_TEMP_DB] 1098 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1099 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1100 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1101 ** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1102 ** <li> [SQLITE_OPEN_WAL] 1103 ** </ul>)^ 1104 ** 1105 ** The file I/O implementation can use the object type flags to 1106 ** change the way it deals with files. For example, an application 1107 ** that does not care about crash recovery or rollback might make 1108 ** the open of a journal file a no-op. Writes to this journal would 1109 ** also be no-ops, and any attempt to read the journal would return 1110 ** SQLITE_IOERR. Or the implementation might recognize that a database 1111 ** file will be doing page-aligned sector reads and writes in a random 1112 ** order and set up its I/O subsystem accordingly. 1113 ** 1114 ** SQLite might also add one of the following flags to the xOpen method: 1115 ** 1116 ** <ul> 1117 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1118 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1119 ** </ul> 1120 ** 1121 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1122 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1123 ** will be set for TEMP databases and their journals, transient 1124 ** databases, and subjournals. 1125 ** 1126 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1127 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1128 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1129 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1130 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1131 ** be created, and that it is an error if it already exists. 1132 ** It is <i>not</i> used to indicate the file should be opened 1133 ** for exclusive access. 1134 ** 1135 ** ^At least szOsFile bytes of memory are allocated by SQLite 1136 ** to hold the [sqlite3_file] structure passed as the third 1137 ** argument to xOpen. The xOpen method does not have to 1138 ** allocate the structure; it should just fill it in. Note that 1139 ** the xOpen method must set the sqlite3_file.pMethods to either 1140 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1141 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1142 ** element will be valid after xOpen returns regardless of the success 1143 ** or failure of the xOpen call. 1144 ** 1145 ** [[sqlite3_vfs.xAccess]] 1146 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1147 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1148 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1149 ** to test whether a file is at least readable. The file can be a 1150 ** directory. 1151 ** 1152 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1153 ** output buffer xFullPathname. The exact size of the output buffer 1154 ** is also passed as a parameter to both methods. If the output buffer 1155 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1156 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1157 ** to prevent this by setting mxPathname to a sufficiently large value. 1158 ** 1159 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1160 ** interfaces are not strictly a part of the filesystem, but they are 1161 ** included in the VFS structure for completeness. 1162 ** The xRandomness() function attempts to return nBytes bytes 1163 ** of good-quality randomness into zOut. The return value is 1164 ** the actual number of bytes of randomness obtained. 1165 ** The xSleep() method causes the calling thread to sleep for at 1166 ** least the number of microseconds given. ^The xCurrentTime() 1167 ** method returns a Julian Day Number for the current date and time as 1168 ** a floating point value. 1169 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1170 ** Day Number multiplied by 86400000 (the number of milliseconds in 1171 ** a 24-hour day). 1172 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1173 ** date and time if that method is available (if iVersion is 2 or 1174 ** greater and the function pointer is not NULL) and will fall back 1175 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1176 ** 1177 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1178 ** are not used by the SQLite core. These optional interfaces are provided 1179 ** by some VFSes to facilitate testing of the VFS code. By overriding 1180 ** system calls with functions under its control, a test program can 1181 ** simulate faults and error conditions that would otherwise be difficult 1182 ** or impossible to induce. The set of system calls that can be overridden 1183 ** varies from one VFS to another, and from one version of the same VFS to the 1184 ** next. Applications that use these interfaces must be prepared for any 1185 ** or all of these interfaces to be NULL or for their behavior to change 1186 ** from one release to the next. Applications must not attempt to access 1187 ** any of these methods if the iVersion of the VFS is less than 3. 1188 */ 1189 typedef struct sqlite3_vfs sqlite3_vfs; 1190 typedef void (*sqlite3_syscall_ptr)(void); 1191 struct sqlite3_vfs { 1192 int iVersion; /* Structure version number (currently 3) */ 1193 int szOsFile; /* Size of subclassed sqlite3_file */ 1194 int mxPathname; /* Maximum file pathname length */ 1195 sqlite3_vfs *pNext; /* Next registered VFS */ 1196 const char *zName; /* Name of this virtual file system */ 1197 void *pAppData; /* Pointer to application-specific data */ 1198 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1199 int flags, int *pOutFlags); 1200 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1201 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1202 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1203 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1204 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1205 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1206 void (*xDlClose)(sqlite3_vfs*, void*); 1207 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1208 int (*xSleep)(sqlite3_vfs*, int microseconds); 1209 int (*xCurrentTime)(sqlite3_vfs*, double*); 1210 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1211 /* 1212 ** The methods above are in version 1 of the sqlite_vfs object 1213 ** definition. Those that follow are added in version 2 or later 1214 */ 1215 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1216 /* 1217 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1218 ** Those below are for version 3 and greater. 1219 */ 1220 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1221 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1222 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1223 /* 1224 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1225 ** New fields may be appended in figure versions. The iVersion 1226 ** value will increment whenever this happens. 1227 */ 1228 }; 1229 1230 /* 1231 ** CAPI3REF: Flags for the xAccess VFS method 1232 ** 1233 ** These integer constants can be used as the third parameter to 1234 ** the xAccess method of an [sqlite3_vfs] object. They determine 1235 ** what kind of permissions the xAccess method is looking for. 1236 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1237 ** simply checks whether the file exists. 1238 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1239 ** checks whether the named directory is both readable and writable 1240 ** (in other words, if files can be added, removed, and renamed within 1241 ** the directory). 1242 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1243 ** [temp_store_directory pragma], though this could change in a future 1244 ** release of SQLite. 1245 ** With SQLITE_ACCESS_READ, the xAccess method 1246 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1247 ** currently unused, though it might be used in a future release of 1248 ** SQLite. 1249 */ 1250 #define SQLITE_ACCESS_EXISTS 0 1251 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1252 #define SQLITE_ACCESS_READ 2 /* Unused */ 1253 1254 /* 1255 ** CAPI3REF: Flags for the xShmLock VFS method 1256 ** 1257 ** These integer constants define the various locking operations 1258 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1259 ** following are the only legal combinations of flags to the 1260 ** xShmLock method: 1261 ** 1262 ** <ul> 1263 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1264 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1265 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1266 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1267 ** </ul> 1268 ** 1269 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1270 ** was given on the corresponding lock. 1271 ** 1272 ** The xShmLock method can transition between unlocked and SHARED or 1273 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1274 ** and EXCLUSIVE. 1275 */ 1276 #define SQLITE_SHM_UNLOCK 1 1277 #define SQLITE_SHM_LOCK 2 1278 #define SQLITE_SHM_SHARED 4 1279 #define SQLITE_SHM_EXCLUSIVE 8 1280 1281 /* 1282 ** CAPI3REF: Maximum xShmLock index 1283 ** 1284 ** The xShmLock method on [sqlite3_io_methods] may use values 1285 ** between 0 and this upper bound as its "offset" argument. 1286 ** The SQLite core will never attempt to acquire or release a 1287 ** lock outside of this range 1288 */ 1289 #define SQLITE_SHM_NLOCK 8 1290 1291 1292 /* 1293 ** CAPI3REF: Initialize The SQLite Library 1294 ** 1295 ** ^The sqlite3_initialize() routine initializes the 1296 ** SQLite library. ^The sqlite3_shutdown() routine 1297 ** deallocates any resources that were allocated by sqlite3_initialize(). 1298 ** These routines are designed to aid in process initialization and 1299 ** shutdown on embedded systems. Workstation applications using 1300 ** SQLite normally do not need to invoke either of these routines. 1301 ** 1302 ** A call to sqlite3_initialize() is an "effective" call if it is 1303 ** the first time sqlite3_initialize() is invoked during the lifetime of 1304 ** the process, or if it is the first time sqlite3_initialize() is invoked 1305 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1306 ** of sqlite3_initialize() does any initialization. All other calls 1307 ** are harmless no-ops.)^ 1308 ** 1309 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1310 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1311 ** an effective call to sqlite3_shutdown() does any deinitialization. 1312 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1313 ** 1314 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1315 ** is not. The sqlite3_shutdown() interface must only be called from a 1316 ** single thread. All open [database connections] must be closed and all 1317 ** other SQLite resources must be deallocated prior to invoking 1318 ** sqlite3_shutdown(). 1319 ** 1320 ** Among other things, ^sqlite3_initialize() will invoke 1321 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1322 ** will invoke sqlite3_os_end(). 1323 ** 1324 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1325 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1326 ** the library (perhaps it is unable to allocate a needed resource such 1327 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1328 ** 1329 ** ^The sqlite3_initialize() routine is called internally by many other 1330 ** SQLite interfaces so that an application usually does not need to 1331 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1332 ** calls sqlite3_initialize() so the SQLite library will be automatically 1333 ** initialized when [sqlite3_open()] is called if it has not be initialized 1334 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1335 ** compile-time option, then the automatic calls to sqlite3_initialize() 1336 ** are omitted and the application must call sqlite3_initialize() directly 1337 ** prior to using any other SQLite interface. For maximum portability, 1338 ** it is recommended that applications always invoke sqlite3_initialize() 1339 ** directly prior to using any other SQLite interface. Future releases 1340 ** of SQLite may require this. In other words, the behavior exhibited 1341 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1342 ** default behavior in some future release of SQLite. 1343 ** 1344 ** The sqlite3_os_init() routine does operating-system specific 1345 ** initialization of the SQLite library. The sqlite3_os_end() 1346 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1347 ** performed by these routines include allocation or deallocation 1348 ** of static resources, initialization of global variables, 1349 ** setting up a default [sqlite3_vfs] module, or setting up 1350 ** a default configuration using [sqlite3_config()]. 1351 ** 1352 ** The application should never invoke either sqlite3_os_init() 1353 ** or sqlite3_os_end() directly. The application should only invoke 1354 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1355 ** interface is called automatically by sqlite3_initialize() and 1356 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1357 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1358 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1359 ** When [custom builds | built for other platforms] 1360 ** (using the [SQLITE_OS_OTHER=1] compile-time 1361 ** option) the application must supply a suitable implementation for 1362 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1363 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1364 ** must return [SQLITE_OK] on success and some other [error code] upon 1365 ** failure. 1366 */ 1367 SQLITE_API int SQLITE_STDCALL sqlite3_initialize(void); 1368 SQLITE_API int SQLITE_STDCALL sqlite3_shutdown(void); 1369 SQLITE_API int SQLITE_STDCALL sqlite3_os_init(void); 1370 SQLITE_API int SQLITE_STDCALL sqlite3_os_end(void); 1371 1372 /* 1373 ** CAPI3REF: Configuring The SQLite Library 1374 ** 1375 ** The sqlite3_config() interface is used to make global configuration 1376 ** changes to SQLite in order to tune SQLite to the specific needs of 1377 ** the application. The default configuration is recommended for most 1378 ** applications and so this routine is usually not necessary. It is 1379 ** provided to support rare applications with unusual needs. 1380 ** 1381 ** <b>The sqlite3_config() interface is not threadsafe. The application 1382 ** must ensure that no other SQLite interfaces are invoked by other 1383 ** threads while sqlite3_config() is running.</b> 1384 ** 1385 ** The sqlite3_config() interface 1386 ** may only be invoked prior to library initialization using 1387 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1388 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1389 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1390 ** Note, however, that ^sqlite3_config() can be called as part of the 1391 ** implementation of an application-defined [sqlite3_os_init()]. 1392 ** 1393 ** The first argument to sqlite3_config() is an integer 1394 ** [configuration option] that determines 1395 ** what property of SQLite is to be configured. Subsequent arguments 1396 ** vary depending on the [configuration option] 1397 ** in the first argument. 1398 ** 1399 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1400 ** ^If the option is unknown or SQLite is unable to set the option 1401 ** then this routine returns a non-zero [error code]. 1402 */ 1403 SQLITE_API int SQLITE_CDECL sqlite3_config(int, ...); 1404 1405 /* 1406 ** CAPI3REF: Configure database connections 1407 ** METHOD: sqlite3 1408 ** 1409 ** The sqlite3_db_config() interface is used to make configuration 1410 ** changes to a [database connection]. The interface is similar to 1411 ** [sqlite3_config()] except that the changes apply to a single 1412 ** [database connection] (specified in the first argument). 1413 ** 1414 ** The second argument to sqlite3_db_config(D,V,...) is the 1415 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1416 ** that indicates what aspect of the [database connection] is being configured. 1417 ** Subsequent arguments vary depending on the configuration verb. 1418 ** 1419 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1420 ** the call is considered successful. 1421 */ 1422 SQLITE_API int SQLITE_CDECL sqlite3_db_config(sqlite3*, int op, ...); 1423 1424 /* 1425 ** CAPI3REF: Memory Allocation Routines 1426 ** 1427 ** An instance of this object defines the interface between SQLite 1428 ** and low-level memory allocation routines. 1429 ** 1430 ** This object is used in only one place in the SQLite interface. 1431 ** A pointer to an instance of this object is the argument to 1432 ** [sqlite3_config()] when the configuration option is 1433 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1434 ** By creating an instance of this object 1435 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1436 ** during configuration, an application can specify an alternative 1437 ** memory allocation subsystem for SQLite to use for all of its 1438 ** dynamic memory needs. 1439 ** 1440 ** Note that SQLite comes with several [built-in memory allocators] 1441 ** that are perfectly adequate for the overwhelming majority of applications 1442 ** and that this object is only useful to a tiny minority of applications 1443 ** with specialized memory allocation requirements. This object is 1444 ** also used during testing of SQLite in order to specify an alternative 1445 ** memory allocator that simulates memory out-of-memory conditions in 1446 ** order to verify that SQLite recovers gracefully from such 1447 ** conditions. 1448 ** 1449 ** The xMalloc, xRealloc, and xFree methods must work like the 1450 ** malloc(), realloc() and free() functions from the standard C library. 1451 ** ^SQLite guarantees that the second argument to 1452 ** xRealloc is always a value returned by a prior call to xRoundup. 1453 ** 1454 ** xSize should return the allocated size of a memory allocation 1455 ** previously obtained from xMalloc or xRealloc. The allocated size 1456 ** is always at least as big as the requested size but may be larger. 1457 ** 1458 ** The xRoundup method returns what would be the allocated size of 1459 ** a memory allocation given a particular requested size. Most memory 1460 ** allocators round up memory allocations at least to the next multiple 1461 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1462 ** Every memory allocation request coming in through [sqlite3_malloc()] 1463 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1464 ** that causes the corresponding memory allocation to fail. 1465 ** 1466 ** The xInit method initializes the memory allocator. For example, 1467 ** it might allocate any require mutexes or initialize internal data 1468 ** structures. The xShutdown method is invoked (indirectly) by 1469 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1470 ** by xInit. The pAppData pointer is used as the only parameter to 1471 ** xInit and xShutdown. 1472 ** 1473 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1474 ** the xInit method, so the xInit method need not be threadsafe. The 1475 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1476 ** not need to be threadsafe either. For all other methods, SQLite 1477 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1478 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1479 ** it is by default) and so the methods are automatically serialized. 1480 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1481 ** methods must be threadsafe or else make their own arrangements for 1482 ** serialization. 1483 ** 1484 ** SQLite will never invoke xInit() more than once without an intervening 1485 ** call to xShutdown(). 1486 */ 1487 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1488 struct sqlite3_mem_methods { 1489 void *(*xMalloc)(int); /* Memory allocation function */ 1490 void (*xFree)(void*); /* Free a prior allocation */ 1491 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1492 int (*xSize)(void*); /* Return the size of an allocation */ 1493 int (*xRoundup)(int); /* Round up request size to allocation size */ 1494 int (*xInit)(void*); /* Initialize the memory allocator */ 1495 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1496 void *pAppData; /* Argument to xInit() and xShutdown() */ 1497 }; 1498 1499 /* 1500 ** CAPI3REF: Configuration Options 1501 ** KEYWORDS: {configuration option} 1502 ** 1503 ** These constants are the available integer configuration options that 1504 ** can be passed as the first argument to the [sqlite3_config()] interface. 1505 ** 1506 ** New configuration options may be added in future releases of SQLite. 1507 ** Existing configuration options might be discontinued. Applications 1508 ** should check the return code from [sqlite3_config()] to make sure that 1509 ** the call worked. The [sqlite3_config()] interface will return a 1510 ** non-zero [error code] if a discontinued or unsupported configuration option 1511 ** is invoked. 1512 ** 1513 ** <dl> 1514 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1515 ** <dd>There are no arguments to this option. ^This option sets the 1516 ** [threading mode] to Single-thread. In other words, it disables 1517 ** all mutexing and puts SQLite into a mode where it can only be used 1518 ** by a single thread. ^If SQLite is compiled with 1519 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1520 ** it is not possible to change the [threading mode] from its default 1521 ** value of Single-thread and so [sqlite3_config()] will return 1522 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1523 ** configuration option.</dd> 1524 ** 1525 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1526 ** <dd>There are no arguments to this option. ^This option sets the 1527 ** [threading mode] to Multi-thread. In other words, it disables 1528 ** mutexing on [database connection] and [prepared statement] objects. 1529 ** The application is responsible for serializing access to 1530 ** [database connections] and [prepared statements]. But other mutexes 1531 ** are enabled so that SQLite will be safe to use in a multi-threaded 1532 ** environment as long as no two threads attempt to use the same 1533 ** [database connection] at the same time. ^If SQLite is compiled with 1534 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1535 ** it is not possible to set the Multi-thread [threading mode] and 1536 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1537 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1538 ** 1539 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1540 ** <dd>There are no arguments to this option. ^This option sets the 1541 ** [threading mode] to Serialized. In other words, this option enables 1542 ** all mutexes including the recursive 1543 ** mutexes on [database connection] and [prepared statement] objects. 1544 ** In this mode (which is the default when SQLite is compiled with 1545 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1546 ** to [database connections] and [prepared statements] so that the 1547 ** application is free to use the same [database connection] or the 1548 ** same [prepared statement] in different threads at the same time. 1549 ** ^If SQLite is compiled with 1550 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1551 ** it is not possible to set the Serialized [threading mode] and 1552 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1553 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1554 ** 1555 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1556 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1557 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1558 ** The argument specifies 1559 ** alternative low-level memory allocation routines to be used in place of 1560 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1561 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1562 ** before the [sqlite3_config()] call returns.</dd> 1563 ** 1564 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1565 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1566 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1567 ** The [sqlite3_mem_methods] 1568 ** structure is filled with the currently defined memory allocation routines.)^ 1569 ** This option can be used to overload the default memory allocation 1570 ** routines with a wrapper that simulations memory allocation failure or 1571 ** tracks memory usage, for example. </dd> 1572 ** 1573 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1574 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1575 ** interpreted as a boolean, which enables or disables the collection of 1576 ** memory allocation statistics. ^(When memory allocation statistics are 1577 ** disabled, the following SQLite interfaces become non-operational: 1578 ** <ul> 1579 ** <li> [sqlite3_memory_used()] 1580 ** <li> [sqlite3_memory_highwater()] 1581 ** <li> [sqlite3_soft_heap_limit64()] 1582 ** <li> [sqlite3_status64()] 1583 ** </ul>)^ 1584 ** ^Memory allocation statistics are enabled by default unless SQLite is 1585 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1586 ** allocation statistics are disabled by default. 1587 ** </dd> 1588 ** 1589 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1590 ** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer 1591 ** that SQLite can use for scratch memory. ^(There are three arguments 1592 ** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte 1593 ** aligned memory buffer from which the scratch allocations will be 1594 ** drawn, the size of each scratch allocation (sz), 1595 ** and the maximum number of scratch allocations (N).)^ 1596 ** The first argument must be a pointer to an 8-byte aligned buffer 1597 ** of at least sz*N bytes of memory. 1598 ** ^SQLite will not use more than one scratch buffers per thread. 1599 ** ^SQLite will never request a scratch buffer that is more than 6 1600 ** times the database page size. 1601 ** ^If SQLite needs needs additional 1602 ** scratch memory beyond what is provided by this configuration option, then 1603 ** [sqlite3_malloc()] will be used to obtain the memory needed.<p> 1604 ** ^When the application provides any amount of scratch memory using 1605 ** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large 1606 ** [sqlite3_malloc|heap allocations]. 1607 ** This can help [Robson proof|prevent memory allocation failures] due to heap 1608 ** fragmentation in low-memory embedded systems. 1609 ** </dd> 1610 ** 1611 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1612 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1613 ** that SQLite can use for the database page cache with the default page 1614 ** cache implementation. 1615 ** This configuration option is a no-op if an application-define page 1616 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1617 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1618 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1619 ** and the number of cache lines (N). 1620 ** The sz argument should be the size of the largest database page 1621 ** (a power of two between 512 and 65536) plus some extra bytes for each 1622 ** page header. ^The number of extra bytes needed by the page header 1623 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1624 ** ^It is harmless, apart from the wasted memory, 1625 ** for the sz parameter to be larger than necessary. The pMem 1626 ** argument must be either a NULL pointer or a pointer to an 8-byte 1627 ** aligned block of memory of at least sz*N bytes, otherwise 1628 ** subsequent behavior is undefined. 1629 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1630 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1631 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1632 ** is exhausted. 1633 ** ^If pMem is NULL and N is non-zero, then each database connection 1634 ** does an initial bulk allocation for page cache memory 1635 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1636 ** of -1024*N bytes if N is negative, . ^If additional 1637 ** page cache memory is needed beyond what is provided by the initial 1638 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1639 ** additional cache line. </dd> 1640 ** 1641 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1642 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1643 ** that SQLite will use for all of its dynamic memory allocation needs 1644 ** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and 1645 ** [SQLITE_CONFIG_PAGECACHE]. 1646 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1647 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1648 ** [SQLITE_ERROR] if invoked otherwise. 1649 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1650 ** An 8-byte aligned pointer to the memory, 1651 ** the number of bytes in the memory buffer, and the minimum allocation size. 1652 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1653 ** to using its default memory allocator (the system malloc() implementation), 1654 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1655 ** memory pointer is not NULL then the alternative memory 1656 ** allocator is engaged to handle all of SQLites memory allocation needs. 1657 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1658 ** boundary or subsequent behavior of SQLite will be undefined. 1659 ** The minimum allocation size is capped at 2**12. Reasonable values 1660 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1661 ** 1662 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1663 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1664 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1665 ** The argument specifies alternative low-level mutex routines to be used 1666 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1667 ** the content of the [sqlite3_mutex_methods] structure before the call to 1668 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1669 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1670 ** the entire mutexing subsystem is omitted from the build and hence calls to 1671 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1672 ** return [SQLITE_ERROR].</dd> 1673 ** 1674 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1675 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1676 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1677 ** [sqlite3_mutex_methods] 1678 ** structure is filled with the currently defined mutex routines.)^ 1679 ** This option can be used to overload the default mutex allocation 1680 ** routines with a wrapper used to track mutex usage for performance 1681 ** profiling or testing, for example. ^If SQLite is compiled with 1682 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1683 ** the entire mutexing subsystem is omitted from the build and hence calls to 1684 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1685 ** return [SQLITE_ERROR].</dd> 1686 ** 1687 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1688 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1689 ** the default size of lookaside memory on each [database connection]. 1690 ** The first argument is the 1691 ** size of each lookaside buffer slot and the second is the number of 1692 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1693 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1694 ** option to [sqlite3_db_config()] can be used to change the lookaside 1695 ** configuration on individual connections.)^ </dd> 1696 ** 1697 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1698 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1699 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1700 ** the interface to a custom page cache implementation.)^ 1701 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1702 ** 1703 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1704 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1705 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1706 ** the current page cache implementation into that object.)^ </dd> 1707 ** 1708 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1709 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1710 ** global [error log]. 1711 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1712 ** function with a call signature of void(*)(void*,int,const char*), 1713 ** and a pointer to void. ^If the function pointer is not NULL, it is 1714 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1715 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1716 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1717 ** passed through as the first parameter to the application-defined logger 1718 ** function whenever that function is invoked. ^The second parameter to 1719 ** the logger function is a copy of the first parameter to the corresponding 1720 ** [sqlite3_log()] call and is intended to be a [result code] or an 1721 ** [extended result code]. ^The third parameter passed to the logger is 1722 ** log message after formatting via [sqlite3_snprintf()]. 1723 ** The SQLite logging interface is not reentrant; the logger function 1724 ** supplied by the application must not invoke any SQLite interface. 1725 ** In a multi-threaded application, the application-defined logger 1726 ** function must be threadsafe. </dd> 1727 ** 1728 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1729 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1730 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1731 ** then URI handling is globally disabled.)^ ^If URI handling is globally 1732 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1733 ** [sqlite3_open16()] or 1734 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1735 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1736 ** connection is opened. ^If it is globally disabled, filenames are 1737 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1738 ** database connection is opened. ^(By default, URI handling is globally 1739 ** disabled. The default value may be changed by compiling with the 1740 ** [SQLITE_USE_URI] symbol defined.)^ 1741 ** 1742 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1743 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1744 ** argument which is interpreted as a boolean in order to enable or disable 1745 ** the use of covering indices for full table scans in the query optimizer. 1746 ** ^The default setting is determined 1747 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1748 ** if that compile-time option is omitted. 1749 ** The ability to disable the use of covering indices for full table scans 1750 ** is because some incorrectly coded legacy applications might malfunction 1751 ** when the optimization is enabled. Providing the ability to 1752 ** disable the optimization allows the older, buggy application code to work 1753 ** without change even with newer versions of SQLite. 1754 ** 1755 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1756 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1757 ** <dd> These options are obsolete and should not be used by new code. 1758 ** They are retained for backwards compatibility but are now no-ops. 1759 ** </dd> 1760 ** 1761 ** [[SQLITE_CONFIG_SQLLOG]] 1762 ** <dt>SQLITE_CONFIG_SQLLOG 1763 ** <dd>This option is only available if sqlite is compiled with the 1764 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1765 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1766 ** The second should be of type (void*). The callback is invoked by the library 1767 ** in three separate circumstances, identified by the value passed as the 1768 ** fourth parameter. If the fourth parameter is 0, then the database connection 1769 ** passed as the second argument has just been opened. The third argument 1770 ** points to a buffer containing the name of the main database file. If the 1771 ** fourth parameter is 1, then the SQL statement that the third parameter 1772 ** points to has just been executed. Or, if the fourth parameter is 2, then 1773 ** the connection being passed as the second parameter is being closed. The 1774 ** third parameter is passed NULL In this case. An example of using this 1775 ** configuration option can be seen in the "test_sqllog.c" source file in 1776 ** the canonical SQLite source tree.</dd> 1777 ** 1778 ** [[SQLITE_CONFIG_MMAP_SIZE]] 1779 ** <dt>SQLITE_CONFIG_MMAP_SIZE 1780 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1781 ** that are the default mmap size limit (the default setting for 1782 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1783 ** ^The default setting can be overridden by each database connection using 1784 ** either the [PRAGMA mmap_size] command, or by using the 1785 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1786 ** will be silently truncated if necessary so that it does not exceed the 1787 ** compile-time maximum mmap size set by the 1788 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1789 ** ^If either argument to this option is negative, then that argument is 1790 ** changed to its compile-time default. 1791 ** 1792 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1793 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1794 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1795 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1796 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1797 ** that specifies the maximum size of the created heap. 1798 ** 1799 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1800 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1801 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1802 ** is a pointer to an integer and writes into that integer the number of extra 1803 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1804 ** The amount of extra space required can change depending on the compiler, 1805 ** target platform, and SQLite version. 1806 ** 1807 ** [[SQLITE_CONFIG_PMASZ]] 1808 ** <dt>SQLITE_CONFIG_PMASZ 1809 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1810 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1811 ** sorter to that integer. The default minimum PMA Size is set by the 1812 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1813 ** to help with sort operations when multithreaded sorting 1814 ** is enabled (using the [PRAGMA threads] command) and the amount of content 1815 ** to be sorted exceeds the page size times the minimum of the 1816 ** [PRAGMA cache_size] setting and this value. 1817 ** </dl> 1818 */ 1819 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1820 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1821 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1822 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1823 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1824 #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1825 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1826 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1827 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1828 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1829 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1830 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1831 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1832 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1833 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1834 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1835 #define SQLITE_CONFIG_URI 17 /* int */ 1836 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1837 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1838 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1839 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1840 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1841 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1842 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 1843 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 1844 1845 /* 1846 ** CAPI3REF: Database Connection Configuration Options 1847 ** 1848 ** These constants are the available integer configuration options that 1849 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 1850 ** 1851 ** New configuration options may be added in future releases of SQLite. 1852 ** Existing configuration options might be discontinued. Applications 1853 ** should check the return code from [sqlite3_db_config()] to make sure that 1854 ** the call worked. ^The [sqlite3_db_config()] interface will return a 1855 ** non-zero [error code] if a discontinued or unsupported configuration option 1856 ** is invoked. 1857 ** 1858 ** <dl> 1859 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1860 ** <dd> ^This option takes three additional arguments that determine the 1861 ** [lookaside memory allocator] configuration for the [database connection]. 1862 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1863 ** pointer to a memory buffer to use for lookaside memory. 1864 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1865 ** may be NULL in which case SQLite will allocate the 1866 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1867 ** size of each lookaside buffer slot. ^The third argument is the number of 1868 ** slots. The size of the buffer in the first argument must be greater than 1869 ** or equal to the product of the second and third arguments. The buffer 1870 ** must be aligned to an 8-byte boundary. ^If the second argument to 1871 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1872 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1873 ** configuration for a database connection can only be changed when that 1874 ** connection is not currently using lookaside memory, or in other words 1875 ** when the "current value" returned by 1876 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1877 ** Any attempt to change the lookaside memory configuration when lookaside 1878 ** memory is in use leaves the configuration unchanged and returns 1879 ** [SQLITE_BUSY].)^</dd> 1880 ** 1881 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1882 ** <dd> ^This option is used to enable or disable the enforcement of 1883 ** [foreign key constraints]. There should be two additional arguments. 1884 ** The first argument is an integer which is 0 to disable FK enforcement, 1885 ** positive to enable FK enforcement or negative to leave FK enforcement 1886 ** unchanged. The second parameter is a pointer to an integer into which 1887 ** is written 0 or 1 to indicate whether FK enforcement is off or on 1888 ** following this call. The second parameter may be a NULL pointer, in 1889 ** which case the FK enforcement setting is not reported back. </dd> 1890 ** 1891 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1892 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1893 ** There should be two additional arguments. 1894 ** The first argument is an integer which is 0 to disable triggers, 1895 ** positive to enable triggers or negative to leave the setting unchanged. 1896 ** The second parameter is a pointer to an integer into which 1897 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 1898 ** following this call. The second parameter may be a NULL pointer, in 1899 ** which case the trigger setting is not reported back. </dd> 1900 ** 1901 ** </dl> 1902 */ 1903 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1904 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1905 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1906 1907 1908 /* 1909 ** CAPI3REF: Enable Or Disable Extended Result Codes 1910 ** METHOD: sqlite3 1911 ** 1912 ** ^The sqlite3_extended_result_codes() routine enables or disables the 1913 ** [extended result codes] feature of SQLite. ^The extended result 1914 ** codes are disabled by default for historical compatibility. 1915 */ 1916 SQLITE_API int SQLITE_STDCALL sqlite3_extended_result_codes(sqlite3*, int onoff); 1917 1918 /* 1919 ** CAPI3REF: Last Insert Rowid 1920 ** METHOD: sqlite3 1921 ** 1922 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 1923 ** has a unique 64-bit signed 1924 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1925 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1926 ** names are not also used by explicitly declared columns. ^If 1927 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 1928 ** is another alias for the rowid. 1929 ** 1930 ** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 1931 ** most recent successful [INSERT] into a rowid table or [virtual table] 1932 ** on database connection D. 1933 ** ^Inserts into [WITHOUT ROWID] tables are not recorded. 1934 ** ^If no successful [INSERT]s into rowid tables 1935 ** have ever occurred on the database connection D, 1936 ** then sqlite3_last_insert_rowid(D) returns zero. 1937 ** 1938 ** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 1939 ** method, then this routine will return the [rowid] of the inserted 1940 ** row as long as the trigger or virtual table method is running. 1941 ** But once the trigger or virtual table method ends, the value returned 1942 ** by this routine reverts to what it was before the trigger or virtual 1943 ** table method began.)^ 1944 ** 1945 ** ^An [INSERT] that fails due to a constraint violation is not a 1946 ** successful [INSERT] and does not change the value returned by this 1947 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1948 ** and INSERT OR ABORT make no changes to the return value of this 1949 ** routine when their insertion fails. ^(When INSERT OR REPLACE 1950 ** encounters a constraint violation, it does not fail. The 1951 ** INSERT continues to completion after deleting rows that caused 1952 ** the constraint problem so INSERT OR REPLACE will always change 1953 ** the return value of this interface.)^ 1954 ** 1955 ** ^For the purposes of this routine, an [INSERT] is considered to 1956 ** be successful even if it is subsequently rolled back. 1957 ** 1958 ** This function is accessible to SQL statements via the 1959 ** [last_insert_rowid() SQL function]. 1960 ** 1961 ** If a separate thread performs a new [INSERT] on the same 1962 ** database connection while the [sqlite3_last_insert_rowid()] 1963 ** function is running and thus changes the last insert [rowid], 1964 ** then the value returned by [sqlite3_last_insert_rowid()] is 1965 ** unpredictable and might not equal either the old or the new 1966 ** last insert [rowid]. 1967 */ 1968 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_last_insert_rowid(sqlite3*); 1969 1970 /* 1971 ** CAPI3REF: Count The Number Of Rows Modified 1972 ** METHOD: sqlite3 1973 ** 1974 ** ^This function returns the number of rows modified, inserted or 1975 ** deleted by the most recently completed INSERT, UPDATE or DELETE 1976 ** statement on the database connection specified by the only parameter. 1977 ** ^Executing any other type of SQL statement does not modify the value 1978 ** returned by this function. 1979 ** 1980 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 1981 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 1982 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 1983 ** 1984 ** Changes to a view that are intercepted by 1985 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 1986 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 1987 ** DELETE statement run on a view is always zero. Only changes made to real 1988 ** tables are counted. 1989 ** 1990 ** Things are more complicated if the sqlite3_changes() function is 1991 ** executed while a trigger program is running. This may happen if the 1992 ** program uses the [changes() SQL function], or if some other callback 1993 ** function invokes sqlite3_changes() directly. Essentially: 1994 ** 1995 ** <ul> 1996 ** <li> ^(Before entering a trigger program the value returned by 1997 ** sqlite3_changes() function is saved. After the trigger program 1998 ** has finished, the original value is restored.)^ 1999 ** 2000 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2001 ** statement sets the value returned by sqlite3_changes() 2002 ** upon completion as normal. Of course, this value will not include 2003 ** any changes performed by sub-triggers, as the sqlite3_changes() 2004 ** value will be saved and restored after each sub-trigger has run.)^ 2005 ** </ul> 2006 ** 2007 ** ^This means that if the changes() SQL function (or similar) is used 2008 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2009 ** returns the value as set when the calling statement began executing. 2010 ** ^If it is used by the second or subsequent such statement within a trigger 2011 ** program, the value returned reflects the number of rows modified by the 2012 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2013 ** 2014 ** See also the [sqlite3_total_changes()] interface, the 2015 ** [count_changes pragma], and the [changes() SQL function]. 2016 ** 2017 ** If a separate thread makes changes on the same database connection 2018 ** while [sqlite3_changes()] is running then the value returned 2019 ** is unpredictable and not meaningful. 2020 */ 2021 SQLITE_API int SQLITE_STDCALL sqlite3_changes(sqlite3*); 2022 2023 /* 2024 ** CAPI3REF: Total Number Of Rows Modified 2025 ** METHOD: sqlite3 2026 ** 2027 ** ^This function returns the total number of rows inserted, modified or 2028 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2029 ** since the database connection was opened, including those executed as 2030 ** part of trigger programs. ^Executing any other type of SQL statement 2031 ** does not affect the value returned by sqlite3_total_changes(). 2032 ** 2033 ** ^Changes made as part of [foreign key actions] are included in the 2034 ** count, but those made as part of REPLACE constraint resolution are 2035 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2036 ** are not counted. 2037 ** 2038 ** See also the [sqlite3_changes()] interface, the 2039 ** [count_changes pragma], and the [total_changes() SQL function]. 2040 ** 2041 ** If a separate thread makes changes on the same database connection 2042 ** while [sqlite3_total_changes()] is running then the value 2043 ** returned is unpredictable and not meaningful. 2044 */ 2045 SQLITE_API int SQLITE_STDCALL sqlite3_total_changes(sqlite3*); 2046 2047 /* 2048 ** CAPI3REF: Interrupt A Long-Running Query 2049 ** METHOD: sqlite3 2050 ** 2051 ** ^This function causes any pending database operation to abort and 2052 ** return at its earliest opportunity. This routine is typically 2053 ** called in response to a user action such as pressing "Cancel" 2054 ** or Ctrl-C where the user wants a long query operation to halt 2055 ** immediately. 2056 ** 2057 ** ^It is safe to call this routine from a thread different from the 2058 ** thread that is currently running the database operation. But it 2059 ** is not safe to call this routine with a [database connection] that 2060 ** is closed or might close before sqlite3_interrupt() returns. 2061 ** 2062 ** ^If an SQL operation is very nearly finished at the time when 2063 ** sqlite3_interrupt() is called, then it might not have an opportunity 2064 ** to be interrupted and might continue to completion. 2065 ** 2066 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2067 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2068 ** that is inside an explicit transaction, then the entire transaction 2069 ** will be rolled back automatically. 2070 ** 2071 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2072 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2073 ** that are started after the sqlite3_interrupt() call and before the 2074 ** running statements reaches zero are interrupted as if they had been 2075 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2076 ** that are started after the running statement count reaches zero are 2077 ** not effected by the sqlite3_interrupt(). 2078 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2079 ** SQL statements is a no-op and has no effect on SQL statements 2080 ** that are started after the sqlite3_interrupt() call returns. 2081 ** 2082 ** If the database connection closes while [sqlite3_interrupt()] 2083 ** is running then bad things will likely happen. 2084 */ 2085 SQLITE_API void SQLITE_STDCALL sqlite3_interrupt(sqlite3*); 2086 2087 /* 2088 ** CAPI3REF: Determine If An SQL Statement Is Complete 2089 ** 2090 ** These routines are useful during command-line input to determine if the 2091 ** currently entered text seems to form a complete SQL statement or 2092 ** if additional input is needed before sending the text into 2093 ** SQLite for parsing. ^These routines return 1 if the input string 2094 ** appears to be a complete SQL statement. ^A statement is judged to be 2095 ** complete if it ends with a semicolon token and is not a prefix of a 2096 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2097 ** string literals or quoted identifier names or comments are not 2098 ** independent tokens (they are part of the token in which they are 2099 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2100 ** and comments that follow the final semicolon are ignored. 2101 ** 2102 ** ^These routines return 0 if the statement is incomplete. ^If a 2103 ** memory allocation fails, then SQLITE_NOMEM is returned. 2104 ** 2105 ** ^These routines do not parse the SQL statements thus 2106 ** will not detect syntactically incorrect SQL. 2107 ** 2108 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2109 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2110 ** automatically by sqlite3_complete16(). If that initialization fails, 2111 ** then the return value from sqlite3_complete16() will be non-zero 2112 ** regardless of whether or not the input SQL is complete.)^ 2113 ** 2114 ** The input to [sqlite3_complete()] must be a zero-terminated 2115 ** UTF-8 string. 2116 ** 2117 ** The input to [sqlite3_complete16()] must be a zero-terminated 2118 ** UTF-16 string in native byte order. 2119 */ 2120 SQLITE_API int SQLITE_STDCALL sqlite3_complete(const char *sql); 2121 SQLITE_API int SQLITE_STDCALL sqlite3_complete16(const void *sql); 2122 2123 /* 2124 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2125 ** KEYWORDS: {busy-handler callback} {busy handler} 2126 ** METHOD: sqlite3 2127 ** 2128 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2129 ** that might be invoked with argument P whenever 2130 ** an attempt is made to access a database table associated with 2131 ** [database connection] D when another thread 2132 ** or process has the table locked. 2133 ** The sqlite3_busy_handler() interface is used to implement 2134 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2135 ** 2136 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2137 ** is returned immediately upon encountering the lock. ^If the busy callback 2138 ** is not NULL, then the callback might be invoked with two arguments. 2139 ** 2140 ** ^The first argument to the busy handler is a copy of the void* pointer which 2141 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2142 ** the busy handler callback is the number of times that the busy handler has 2143 ** been invoked previously for the same locking event. ^If the 2144 ** busy callback returns 0, then no additional attempts are made to 2145 ** access the database and [SQLITE_BUSY] is returned 2146 ** to the application. 2147 ** ^If the callback returns non-zero, then another attempt 2148 ** is made to access the database and the cycle repeats. 2149 ** 2150 ** The presence of a busy handler does not guarantee that it will be invoked 2151 ** when there is lock contention. ^If SQLite determines that invoking the busy 2152 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2153 ** to the application instead of invoking the 2154 ** busy handler. 2155 ** Consider a scenario where one process is holding a read lock that 2156 ** it is trying to promote to a reserved lock and 2157 ** a second process is holding a reserved lock that it is trying 2158 ** to promote to an exclusive lock. The first process cannot proceed 2159 ** because it is blocked by the second and the second process cannot 2160 ** proceed because it is blocked by the first. If both processes 2161 ** invoke the busy handlers, neither will make any progress. Therefore, 2162 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2163 ** will induce the first process to release its read lock and allow 2164 ** the second process to proceed. 2165 ** 2166 ** ^The default busy callback is NULL. 2167 ** 2168 ** ^(There can only be a single busy handler defined for each 2169 ** [database connection]. Setting a new busy handler clears any 2170 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2171 ** or evaluating [PRAGMA busy_timeout=N] will change the 2172 ** busy handler and thus clear any previously set busy handler. 2173 ** 2174 ** The busy callback should not take any actions which modify the 2175 ** database connection that invoked the busy handler. In other words, 2176 ** the busy handler is not reentrant. Any such actions 2177 ** result in undefined behavior. 2178 ** 2179 ** A busy handler must not close the database connection 2180 ** or [prepared statement] that invoked the busy handler. 2181 */ 2182 SQLITE_API int SQLITE_STDCALL sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 2183 2184 /* 2185 ** CAPI3REF: Set A Busy Timeout 2186 ** METHOD: sqlite3 2187 ** 2188 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2189 ** for a specified amount of time when a table is locked. ^The handler 2190 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2191 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2192 ** the handler returns 0 which causes [sqlite3_step()] to return 2193 ** [SQLITE_BUSY]. 2194 ** 2195 ** ^Calling this routine with an argument less than or equal to zero 2196 ** turns off all busy handlers. 2197 ** 2198 ** ^(There can only be a single busy handler for a particular 2199 ** [database connection] at any given moment. If another busy handler 2200 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2201 ** this routine, that other busy handler is cleared.)^ 2202 ** 2203 ** See also: [PRAGMA busy_timeout] 2204 */ 2205 SQLITE_API int SQLITE_STDCALL sqlite3_busy_timeout(sqlite3*, int ms); 2206 2207 /* 2208 ** CAPI3REF: Convenience Routines For Running Queries 2209 ** METHOD: sqlite3 2210 ** 2211 ** This is a legacy interface that is preserved for backwards compatibility. 2212 ** Use of this interface is not recommended. 2213 ** 2214 ** Definition: A <b>result table</b> is memory data structure created by the 2215 ** [sqlite3_get_table()] interface. A result table records the 2216 ** complete query results from one or more queries. 2217 ** 2218 ** The table conceptually has a number of rows and columns. But 2219 ** these numbers are not part of the result table itself. These 2220 ** numbers are obtained separately. Let N be the number of rows 2221 ** and M be the number of columns. 2222 ** 2223 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2224 ** There are (N+1)*M elements in the array. The first M pointers point 2225 ** to zero-terminated strings that contain the names of the columns. 2226 ** The remaining entries all point to query results. NULL values result 2227 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2228 ** string representation as returned by [sqlite3_column_text()]. 2229 ** 2230 ** A result table might consist of one or more memory allocations. 2231 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2232 ** A result table should be deallocated using [sqlite3_free_table()]. 2233 ** 2234 ** ^(As an example of the result table format, suppose a query result 2235 ** is as follows: 2236 ** 2237 ** <blockquote><pre> 2238 ** Name | Age 2239 ** ----------------------- 2240 ** Alice | 43 2241 ** Bob | 28 2242 ** Cindy | 21 2243 ** </pre></blockquote> 2244 ** 2245 ** There are two column (M==2) and three rows (N==3). Thus the 2246 ** result table has 8 entries. Suppose the result table is stored 2247 ** in an array names azResult. Then azResult holds this content: 2248 ** 2249 ** <blockquote><pre> 2250 ** azResult[0] = "Name"; 2251 ** azResult[1] = "Age"; 2252 ** azResult[2] = "Alice"; 2253 ** azResult[3] = "43"; 2254 ** azResult[4] = "Bob"; 2255 ** azResult[5] = "28"; 2256 ** azResult[6] = "Cindy"; 2257 ** azResult[7] = "21"; 2258 ** </pre></blockquote>)^ 2259 ** 2260 ** ^The sqlite3_get_table() function evaluates one or more 2261 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2262 ** string of its 2nd parameter and returns a result table to the 2263 ** pointer given in its 3rd parameter. 2264 ** 2265 ** After the application has finished with the result from sqlite3_get_table(), 2266 ** it must pass the result table pointer to sqlite3_free_table() in order to 2267 ** release the memory that was malloced. Because of the way the 2268 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2269 ** function must not try to call [sqlite3_free()] directly. Only 2270 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2271 ** 2272 ** The sqlite3_get_table() interface is implemented as a wrapper around 2273 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2274 ** to any internal data structures of SQLite. It uses only the public 2275 ** interface defined here. As a consequence, errors that occur in the 2276 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2277 ** reflected in subsequent calls to [sqlite3_errcode()] or 2278 ** [sqlite3_errmsg()]. 2279 */ 2280 SQLITE_API int SQLITE_STDCALL sqlite3_get_table( 2281 sqlite3 *db, /* An open database */ 2282 const char *zSql, /* SQL to be evaluated */ 2283 char ***pazResult, /* Results of the query */ 2284 int *pnRow, /* Number of result rows written here */ 2285 int *pnColumn, /* Number of result columns written here */ 2286 char **pzErrmsg /* Error msg written here */ 2287 ); 2288 SQLITE_API void SQLITE_STDCALL sqlite3_free_table(char **result); 2289 2290 /* 2291 ** CAPI3REF: Formatted String Printing Functions 2292 ** 2293 ** These routines are work-alikes of the "printf()" family of functions 2294 ** from the standard C library. 2295 ** These routines understand most of the common K&R formatting options, 2296 ** plus some additional non-standard formats, detailed below. 2297 ** Note that some of the more obscure formatting options from recent 2298 ** C-library standards are omitted from this implementation. 2299 ** 2300 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2301 ** results into memory obtained from [sqlite3_malloc()]. 2302 ** The strings returned by these two routines should be 2303 ** released by [sqlite3_free()]. ^Both routines return a 2304 ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2305 ** memory to hold the resulting string. 2306 ** 2307 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2308 ** the standard C library. The result is written into the 2309 ** buffer supplied as the second parameter whose size is given by 2310 ** the first parameter. Note that the order of the 2311 ** first two parameters is reversed from snprintf().)^ This is an 2312 ** historical accident that cannot be fixed without breaking 2313 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2314 ** returns a pointer to its buffer instead of the number of 2315 ** characters actually written into the buffer.)^ We admit that 2316 ** the number of characters written would be a more useful return 2317 ** value but we cannot change the implementation of sqlite3_snprintf() 2318 ** now without breaking compatibility. 2319 ** 2320 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2321 ** guarantees that the buffer is always zero-terminated. ^The first 2322 ** parameter "n" is the total size of the buffer, including space for 2323 ** the zero terminator. So the longest string that can be completely 2324 ** written will be n-1 characters. 2325 ** 2326 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2327 ** 2328 ** These routines all implement some additional formatting 2329 ** options that are useful for constructing SQL statements. 2330 ** All of the usual printf() formatting options apply. In addition, there 2331 ** is are "%q", "%Q", "%w" and "%z" options. 2332 ** 2333 ** ^(The %q option works like %s in that it substitutes a nul-terminated 2334 ** string from the argument list. But %q also doubles every '\'' character. 2335 ** %q is designed for use inside a string literal.)^ By doubling each '\'' 2336 ** character it escapes that character and allows it to be inserted into 2337 ** the string. 2338 ** 2339 ** For example, assume the string variable zText contains text as follows: 2340 ** 2341 ** <blockquote><pre> 2342 ** char *zText = "It's a happy day!"; 2343 ** </pre></blockquote> 2344 ** 2345 ** One can use this text in an SQL statement as follows: 2346 ** 2347 ** <blockquote><pre> 2348 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2349 ** sqlite3_exec(db, zSQL, 0, 0, 0); 2350 ** sqlite3_free(zSQL); 2351 ** </pre></blockquote> 2352 ** 2353 ** Because the %q format string is used, the '\'' character in zText 2354 ** is escaped and the SQL generated is as follows: 2355 ** 2356 ** <blockquote><pre> 2357 ** INSERT INTO table1 VALUES('It''s a happy day!') 2358 ** </pre></blockquote> 2359 ** 2360 ** This is correct. Had we used %s instead of %q, the generated SQL 2361 ** would have looked like this: 2362 ** 2363 ** <blockquote><pre> 2364 ** INSERT INTO table1 VALUES('It's a happy day!'); 2365 ** </pre></blockquote> 2366 ** 2367 ** This second example is an SQL syntax error. As a general rule you should 2368 ** always use %q instead of %s when inserting text into a string literal. 2369 ** 2370 ** ^(The %Q option works like %q except it also adds single quotes around 2371 ** the outside of the total string. Additionally, if the parameter in the 2372 ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2373 ** single quotes).)^ So, for example, one could say: 2374 ** 2375 ** <blockquote><pre> 2376 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2377 ** sqlite3_exec(db, zSQL, 0, 0, 0); 2378 ** sqlite3_free(zSQL); 2379 ** </pre></blockquote> 2380 ** 2381 ** The code above will render a correct SQL statement in the zSQL 2382 ** variable even if the zText variable is a NULL pointer. 2383 ** 2384 ** ^(The "%w" formatting option is like "%q" except that it expects to 2385 ** be contained within double-quotes instead of single quotes, and it 2386 ** escapes the double-quote character instead of the single-quote 2387 ** character.)^ The "%w" formatting option is intended for safely inserting 2388 ** table and column names into a constructed SQL statement. 2389 ** 2390 ** ^(The "%z" formatting option works like "%s" but with the 2391 ** addition that after the string has been read and copied into 2392 ** the result, [sqlite3_free()] is called on the input string.)^ 2393 */ 2394 SQLITE_API char *SQLITE_CDECL sqlite3_mprintf(const char*,...); 2395 SQLITE_API char *SQLITE_STDCALL sqlite3_vmprintf(const char*, va_list); 2396 SQLITE_API char *SQLITE_CDECL sqlite3_snprintf(int,char*,const char*, ...); 2397 SQLITE_API char *SQLITE_STDCALL sqlite3_vsnprintf(int,char*,const char*, va_list); 2398 2399 /* 2400 ** CAPI3REF: Memory Allocation Subsystem 2401 ** 2402 ** The SQLite core uses these three routines for all of its own 2403 ** internal memory allocation needs. "Core" in the previous sentence 2404 ** does not include operating-system specific VFS implementation. The 2405 ** Windows VFS uses native malloc() and free() for some operations. 2406 ** 2407 ** ^The sqlite3_malloc() routine returns a pointer to a block 2408 ** of memory at least N bytes in length, where N is the parameter. 2409 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2410 ** memory, it returns a NULL pointer. ^If the parameter N to 2411 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2412 ** a NULL pointer. 2413 ** 2414 ** ^The sqlite3_malloc64(N) routine works just like 2415 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2416 ** of a signed 32-bit integer. 2417 ** 2418 ** ^Calling sqlite3_free() with a pointer previously returned 2419 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2420 ** that it might be reused. ^The sqlite3_free() routine is 2421 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2422 ** to sqlite3_free() is harmless. After being freed, memory 2423 ** should neither be read nor written. Even reading previously freed 2424 ** memory might result in a segmentation fault or other severe error. 2425 ** Memory corruption, a segmentation fault, or other severe error 2426 ** might result if sqlite3_free() is called with a non-NULL pointer that 2427 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2428 ** 2429 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 2430 ** prior memory allocation X to be at least N bytes. 2431 ** ^If the X parameter to sqlite3_realloc(X,N) 2432 ** is a NULL pointer then its behavior is identical to calling 2433 ** sqlite3_malloc(N). 2434 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2435 ** negative then the behavior is exactly the same as calling 2436 ** sqlite3_free(X). 2437 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2438 ** of at least N bytes in size or NULL if insufficient memory is available. 2439 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2440 ** of the prior allocation are copied into the beginning of buffer returned 2441 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 2442 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2443 ** prior allocation is not freed. 2444 ** 2445 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 2446 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2447 ** of a 32-bit signed integer. 2448 ** 2449 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2450 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2451 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2452 ** ^The value returned by sqlite3_msize(X) might be larger than the number 2453 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 2454 ** sqlite3_msize(X) returns zero. If X points to something that is not 2455 ** the beginning of memory allocation, or if it points to a formerly 2456 ** valid memory allocation that has now been freed, then the behavior 2457 ** of sqlite3_msize(X) is undefined and possibly harmful. 2458 ** 2459 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2460 ** sqlite3_malloc64(), and sqlite3_realloc64() 2461 ** is always aligned to at least an 8 byte boundary, or to a 2462 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2463 ** option is used. 2464 ** 2465 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2466 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2467 ** implementation of these routines to be omitted. That capability 2468 ** is no longer provided. Only built-in memory allocators can be used. 2469 ** 2470 ** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2471 ** the system malloc() and free() directly when converting 2472 ** filenames between the UTF-8 encoding used by SQLite 2473 ** and whatever filename encoding is used by the particular Windows 2474 ** installation. Memory allocation errors were detected, but 2475 ** they were reported back as [SQLITE_CANTOPEN] or 2476 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2477 ** 2478 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2479 ** must be either NULL or else pointers obtained from a prior 2480 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2481 ** not yet been released. 2482 ** 2483 ** The application must not read or write any part of 2484 ** a block of memory after it has been released using 2485 ** [sqlite3_free()] or [sqlite3_realloc()]. 2486 */ 2487 SQLITE_API void *SQLITE_STDCALL sqlite3_malloc(int); 2488 SQLITE_API void *SQLITE_STDCALL sqlite3_malloc64(sqlite3_uint64); 2489 SQLITE_API void *SQLITE_STDCALL sqlite3_realloc(void*, int); 2490 SQLITE_API void *SQLITE_STDCALL sqlite3_realloc64(void*, sqlite3_uint64); 2491 SQLITE_API void SQLITE_STDCALL sqlite3_free(void*); 2492 SQLITE_API sqlite3_uint64 SQLITE_STDCALL sqlite3_msize(void*); 2493 2494 /* 2495 ** CAPI3REF: Memory Allocator Statistics 2496 ** 2497 ** SQLite provides these two interfaces for reporting on the status 2498 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2499 ** routines, which form the built-in memory allocation subsystem. 2500 ** 2501 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2502 ** of memory currently outstanding (malloced but not freed). 2503 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2504 ** value of [sqlite3_memory_used()] since the high-water mark 2505 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2506 ** [sqlite3_memory_highwater()] include any overhead 2507 ** added by SQLite in its implementation of [sqlite3_malloc()], 2508 ** but not overhead added by the any underlying system library 2509 ** routines that [sqlite3_malloc()] may call. 2510 ** 2511 ** ^The memory high-water mark is reset to the current value of 2512 ** [sqlite3_memory_used()] if and only if the parameter to 2513 ** [sqlite3_memory_highwater()] is true. ^The value returned 2514 ** by [sqlite3_memory_highwater(1)] is the high-water mark 2515 ** prior to the reset. 2516 */ 2517 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_used(void); 2518 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_highwater(int resetFlag); 2519 2520 /* 2521 ** CAPI3REF: Pseudo-Random Number Generator 2522 ** 2523 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2524 ** select random [ROWID | ROWIDs] when inserting new records into a table that 2525 ** already uses the largest possible [ROWID]. The PRNG is also used for 2526 ** the build-in random() and randomblob() SQL functions. This interface allows 2527 ** applications to access the same PRNG for other purposes. 2528 ** 2529 ** ^A call to this routine stores N bytes of randomness into buffer P. 2530 ** ^The P parameter can be a NULL pointer. 2531 ** 2532 ** ^If this routine has not been previously called or if the previous 2533 ** call had N less than one or a NULL pointer for P, then the PRNG is 2534 ** seeded using randomness obtained from the xRandomness method of 2535 ** the default [sqlite3_vfs] object. 2536 ** ^If the previous call to this routine had an N of 1 or more and a 2537 ** non-NULL P then the pseudo-randomness is generated 2538 ** internally and without recourse to the [sqlite3_vfs] xRandomness 2539 ** method. 2540 */ 2541 SQLITE_API void SQLITE_STDCALL sqlite3_randomness(int N, void *P); 2542 2543 /* 2544 ** CAPI3REF: Compile-Time Authorization Callbacks 2545 ** METHOD: sqlite3 2546 ** 2547 ** ^This routine registers an authorizer callback with a particular 2548 ** [database connection], supplied in the first argument. 2549 ** ^The authorizer callback is invoked as SQL statements are being compiled 2550 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2551 ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2552 ** points during the compilation process, as logic is being created 2553 ** to perform various actions, the authorizer callback is invoked to 2554 ** see if those actions are allowed. ^The authorizer callback should 2555 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2556 ** specific action but allow the SQL statement to continue to be 2557 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2558 ** rejected with an error. ^If the authorizer callback returns 2559 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2560 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2561 ** the authorizer will fail with an error message. 2562 ** 2563 ** When the callback returns [SQLITE_OK], that means the operation 2564 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 2565 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 2566 ** authorizer will fail with an error message explaining that 2567 ** access is denied. 2568 ** 2569 ** ^The first parameter to the authorizer callback is a copy of the third 2570 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2571 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 2572 ** the particular action to be authorized. ^The third through sixth parameters 2573 ** to the callback are zero-terminated strings that contain additional 2574 ** details about the action to be authorized. 2575 ** 2576 ** ^If the action code is [SQLITE_READ] 2577 ** and the callback returns [SQLITE_IGNORE] then the 2578 ** [prepared statement] statement is constructed to substitute 2579 ** a NULL value in place of the table column that would have 2580 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2581 ** return can be used to deny an untrusted user access to individual 2582 ** columns of a table. 2583 ** ^If the action code is [SQLITE_DELETE] and the callback returns 2584 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2585 ** [truncate optimization] is disabled and all rows are deleted individually. 2586 ** 2587 ** An authorizer is used when [sqlite3_prepare | preparing] 2588 ** SQL statements from an untrusted source, to ensure that the SQL statements 2589 ** do not try to access data they are not allowed to see, or that they do not 2590 ** try to execute malicious statements that damage the database. For 2591 ** example, an application may allow a user to enter arbitrary 2592 ** SQL queries for evaluation by a database. But the application does 2593 ** not want the user to be able to make arbitrary changes to the 2594 ** database. An authorizer could then be put in place while the 2595 ** user-entered SQL is being [sqlite3_prepare | prepared] that 2596 ** disallows everything except [SELECT] statements. 2597 ** 2598 ** Applications that need to process SQL from untrusted sources 2599 ** might also consider lowering resource limits using [sqlite3_limit()] 2600 ** and limiting database size using the [max_page_count] [PRAGMA] 2601 ** in addition to using an authorizer. 2602 ** 2603 ** ^(Only a single authorizer can be in place on a database connection 2604 ** at a time. Each call to sqlite3_set_authorizer overrides the 2605 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2606 ** The authorizer is disabled by default. 2607 ** 2608 ** The authorizer callback must not do anything that will modify 2609 ** the database connection that invoked the authorizer callback. 2610 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2611 ** database connections for the meaning of "modify" in this paragraph. 2612 ** 2613 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2614 ** statement might be re-prepared during [sqlite3_step()] due to a 2615 ** schema change. Hence, the application should ensure that the 2616 ** correct authorizer callback remains in place during the [sqlite3_step()]. 2617 ** 2618 ** ^Note that the authorizer callback is invoked only during 2619 ** [sqlite3_prepare()] or its variants. Authorization is not 2620 ** performed during statement evaluation in [sqlite3_step()], unless 2621 ** as stated in the previous paragraph, sqlite3_step() invokes 2622 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2623 */ 2624 SQLITE_API int SQLITE_STDCALL sqlite3_set_authorizer( 2625 sqlite3*, 2626 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2627 void *pUserData 2628 ); 2629 2630 /* 2631 ** CAPI3REF: Authorizer Return Codes 2632 ** 2633 ** The [sqlite3_set_authorizer | authorizer callback function] must 2634 ** return either [SQLITE_OK] or one of these two constants in order 2635 ** to signal SQLite whether or not the action is permitted. See the 2636 ** [sqlite3_set_authorizer | authorizer documentation] for additional 2637 ** information. 2638 ** 2639 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2640 ** returned from the [sqlite3_vtab_on_conflict()] interface. 2641 */ 2642 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2643 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2644 2645 /* 2646 ** CAPI3REF: Authorizer Action Codes 2647 ** 2648 ** The [sqlite3_set_authorizer()] interface registers a callback function 2649 ** that is invoked to authorize certain SQL statement actions. The 2650 ** second parameter to the callback is an integer code that specifies 2651 ** what action is being authorized. These are the integer action codes that 2652 ** the authorizer callback may be passed. 2653 ** 2654 ** These action code values signify what kind of operation is to be 2655 ** authorized. The 3rd and 4th parameters to the authorization 2656 ** callback function will be parameters or NULL depending on which of these 2657 ** codes is used as the second parameter. ^(The 5th parameter to the 2658 ** authorizer callback is the name of the database ("main", "temp", 2659 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2660 ** is the name of the inner-most trigger or view that is responsible for 2661 ** the access attempt or NULL if this access attempt is directly from 2662 ** top-level SQL code. 2663 */ 2664 /******************************************* 3rd ************ 4th ***********/ 2665 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2666 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2667 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2668 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2669 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2670 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2671 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2672 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2673 #define SQLITE_DELETE 9 /* Table Name NULL */ 2674 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2675 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2676 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2677 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2678 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2679 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2680 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2681 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2682 #define SQLITE_INSERT 18 /* Table Name NULL */ 2683 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2684 #define SQLITE_READ 20 /* Table Name Column Name */ 2685 #define SQLITE_SELECT 21 /* NULL NULL */ 2686 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 2687 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 2688 #define SQLITE_ATTACH 24 /* Filename NULL */ 2689 #define SQLITE_DETACH 25 /* Database Name NULL */ 2690 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2691 #define SQLITE_REINDEX 27 /* Index Name NULL */ 2692 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 2693 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2694 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2695 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 2696 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2697 #define SQLITE_COPY 0 /* No longer used */ 2698 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 2699 2700 /* 2701 ** CAPI3REF: Tracing And Profiling Functions 2702 ** METHOD: sqlite3 2703 ** 2704 ** These routines register callback functions that can be used for 2705 ** tracing and profiling the execution of SQL statements. 2706 ** 2707 ** ^The callback function registered by sqlite3_trace() is invoked at 2708 ** various times when an SQL statement is being run by [sqlite3_step()]. 2709 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2710 ** SQL statement text as the statement first begins executing. 2711 ** ^(Additional sqlite3_trace() callbacks might occur 2712 ** as each triggered subprogram is entered. The callbacks for triggers 2713 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 2714 ** 2715 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2716 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2717 ** 2718 ** ^The callback function registered by sqlite3_profile() is invoked 2719 ** as each SQL statement finishes. ^The profile callback contains 2720 ** the original statement text and an estimate of wall-clock time 2721 ** of how long that statement took to run. ^The profile callback 2722 ** time is in units of nanoseconds, however the current implementation 2723 ** is only capable of millisecond resolution so the six least significant 2724 ** digits in the time are meaningless. Future versions of SQLite 2725 ** might provide greater resolution on the profiler callback. The 2726 ** sqlite3_profile() function is considered experimental and is 2727 ** subject to change in future versions of SQLite. 2728 */ 2729 SQLITE_API void *SQLITE_STDCALL sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2730 SQLITE_API SQLITE_EXPERIMENTAL void *SQLITE_STDCALL sqlite3_profile(sqlite3*, 2731 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2732 2733 /* 2734 ** CAPI3REF: Query Progress Callbacks 2735 ** METHOD: sqlite3 2736 ** 2737 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2738 ** function X to be invoked periodically during long running calls to 2739 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2740 ** database connection D. An example use for this 2741 ** interface is to keep a GUI updated during a large query. 2742 ** 2743 ** ^The parameter P is passed through as the only parameter to the 2744 ** callback function X. ^The parameter N is the approximate number of 2745 ** [virtual machine instructions] that are evaluated between successive 2746 ** invocations of the callback X. ^If N is less than one then the progress 2747 ** handler is disabled. 2748 ** 2749 ** ^Only a single progress handler may be defined at one time per 2750 ** [database connection]; setting a new progress handler cancels the 2751 ** old one. ^Setting parameter X to NULL disables the progress handler. 2752 ** ^The progress handler is also disabled by setting N to a value less 2753 ** than 1. 2754 ** 2755 ** ^If the progress callback returns non-zero, the operation is 2756 ** interrupted. This feature can be used to implement a 2757 ** "Cancel" button on a GUI progress dialog box. 2758 ** 2759 ** The progress handler callback must not do anything that will modify 2760 ** the database connection that invoked the progress handler. 2761 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2762 ** database connections for the meaning of "modify" in this paragraph. 2763 ** 2764 */ 2765 SQLITE_API void SQLITE_STDCALL sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2766 2767 /* 2768 ** CAPI3REF: Opening A New Database Connection 2769 ** CONSTRUCTOR: sqlite3 2770 ** 2771 ** ^These routines open an SQLite database file as specified by the 2772 ** filename argument. ^The filename argument is interpreted as UTF-8 for 2773 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2774 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 2775 ** returned in *ppDb, even if an error occurs. The only exception is that 2776 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2777 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2778 ** object.)^ ^(If the database is opened (and/or created) successfully, then 2779 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2780 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2781 ** an English language description of the error following a failure of any 2782 ** of the sqlite3_open() routines. 2783 ** 2784 ** ^The default encoding will be UTF-8 for databases created using 2785 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 2786 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 2787 ** 2788 ** Whether or not an error occurs when it is opened, resources 2789 ** associated with the [database connection] handle should be released by 2790 ** passing it to [sqlite3_close()] when it is no longer required. 2791 ** 2792 ** The sqlite3_open_v2() interface works like sqlite3_open() 2793 ** except that it accepts two additional parameters for additional control 2794 ** over the new database connection. ^(The flags parameter to 2795 ** sqlite3_open_v2() can take one of 2796 ** the following three values, optionally combined with the 2797 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2798 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2799 ** 2800 ** <dl> 2801 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2802 ** <dd>The database is opened in read-only mode. If the database does not 2803 ** already exist, an error is returned.</dd>)^ 2804 ** 2805 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2806 ** <dd>The database is opened for reading and writing if possible, or reading 2807 ** only if the file is write protected by the operating system. In either 2808 ** case the database must already exist, otherwise an error is returned.</dd>)^ 2809 ** 2810 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2811 ** <dd>The database is opened for reading and writing, and is created if 2812 ** it does not already exist. This is the behavior that is always used for 2813 ** sqlite3_open() and sqlite3_open16().</dd>)^ 2814 ** </dl> 2815 ** 2816 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 2817 ** combinations shown above optionally combined with other 2818 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2819 ** then the behavior is undefined. 2820 ** 2821 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2822 ** opens in the multi-thread [threading mode] as long as the single-thread 2823 ** mode has not been set at compile-time or start-time. ^If the 2824 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2825 ** in the serialized [threading mode] unless single-thread was 2826 ** previously selected at compile-time or start-time. 2827 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2828 ** eligible to use [shared cache mode], regardless of whether or not shared 2829 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 2830 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 2831 ** participate in [shared cache mode] even if it is enabled. 2832 ** 2833 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 2834 ** [sqlite3_vfs] object that defines the operating system interface that 2835 ** the new database connection should use. ^If the fourth parameter is 2836 ** a NULL pointer then the default [sqlite3_vfs] object is used. 2837 ** 2838 ** ^If the filename is ":memory:", then a private, temporary in-memory database 2839 ** is created for the connection. ^This in-memory database will vanish when 2840 ** the database connection is closed. Future versions of SQLite might 2841 ** make use of additional special filenames that begin with the ":" character. 2842 ** It is recommended that when a database filename actually does begin with 2843 ** a ":" character you should prefix the filename with a pathname such as 2844 ** "./" to avoid ambiguity. 2845 ** 2846 ** ^If the filename is an empty string, then a private, temporary 2847 ** on-disk database will be created. ^This private database will be 2848 ** automatically deleted as soon as the database connection is closed. 2849 ** 2850 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 2851 ** 2852 ** ^If [URI filename] interpretation is enabled, and the filename argument 2853 ** begins with "file:", then the filename is interpreted as a URI. ^URI 2854 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 2855 ** set in the fourth argument to sqlite3_open_v2(), or if it has 2856 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 2857 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 2858 ** As of SQLite version 3.7.7, URI filename interpretation is turned off 2859 ** by default, but future releases of SQLite might enable URI filename 2860 ** interpretation by default. See "[URI filenames]" for additional 2861 ** information. 2862 ** 2863 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 2864 ** authority, then it must be either an empty string or the string 2865 ** "localhost". ^If the authority is not an empty string or "localhost", an 2866 ** error is returned to the caller. ^The fragment component of a URI, if 2867 ** present, is ignored. 2868 ** 2869 ** ^SQLite uses the path component of the URI as the name of the disk file 2870 ** which contains the database. ^If the path begins with a '/' character, 2871 ** then it is interpreted as an absolute path. ^If the path does not begin 2872 ** with a '/' (meaning that the authority section is omitted from the URI) 2873 ** then the path is interpreted as a relative path. 2874 ** ^(On windows, the first component of an absolute path 2875 ** is a drive specification (e.g. "C:").)^ 2876 ** 2877 ** [[core URI query parameters]] 2878 ** The query component of a URI may contain parameters that are interpreted 2879 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 2880 ** SQLite and its built-in [VFSes] interpret the 2881 ** following query parameters: 2882 ** 2883 ** <ul> 2884 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 2885 ** a VFS object that provides the operating system interface that should 2886 ** be used to access the database file on disk. ^If this option is set to 2887 ** an empty string the default VFS object is used. ^Specifying an unknown 2888 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 2889 ** present, then the VFS specified by the option takes precedence over 2890 ** the value passed as the fourth parameter to sqlite3_open_v2(). 2891 ** 2892 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 2893 ** "rwc", or "memory". Attempting to set it to any other value is 2894 ** an error)^. 2895 ** ^If "ro" is specified, then the database is opened for read-only 2896 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 2897 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 2898 ** "rw", then the database is opened for read-write (but not create) 2899 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 2900 ** been set. ^Value "rwc" is equivalent to setting both 2901 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 2902 ** set to "memory" then a pure [in-memory database] that never reads 2903 ** or writes from disk is used. ^It is an error to specify a value for 2904 ** the mode parameter that is less restrictive than that specified by 2905 ** the flags passed in the third parameter to sqlite3_open_v2(). 2906 ** 2907 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 2908 ** "private". ^Setting it to "shared" is equivalent to setting the 2909 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 2910 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 2911 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 2912 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 2913 ** a URI filename, its value overrides any behavior requested by setting 2914 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 2915 ** 2916 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 2917 ** [powersafe overwrite] property does or does not apply to the 2918 ** storage media on which the database file resides. 2919 ** 2920 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 2921 ** which if set disables file locking in rollback journal modes. This 2922 ** is useful for accessing a database on a filesystem that does not 2923 ** support locking. Caution: Database corruption might result if two 2924 ** or more processes write to the same database and any one of those 2925 ** processes uses nolock=1. 2926 ** 2927 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 2928 ** parameter that indicates that the database file is stored on 2929 ** read-only media. ^When immutable is set, SQLite assumes that the 2930 ** database file cannot be changed, even by a process with higher 2931 ** privilege, and so the database is opened read-only and all locking 2932 ** and change detection is disabled. Caution: Setting the immutable 2933 ** property on a database file that does in fact change can result 2934 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 2935 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 2936 ** 2937 ** </ul> 2938 ** 2939 ** ^Specifying an unknown parameter in the query component of a URI is not an 2940 ** error. Future versions of SQLite might understand additional query 2941 ** parameters. See "[query parameters with special meaning to SQLite]" for 2942 ** additional information. 2943 ** 2944 ** [[URI filename examples]] <h3>URI filename examples</h3> 2945 ** 2946 ** <table border="1" align=center cellpadding=5> 2947 ** <tr><th> URI filenames <th> Results 2948 ** <tr><td> file:data.db <td> 2949 ** Open the file "data.db" in the current directory. 2950 ** <tr><td> file:/home/fred/data.db<br> 2951 ** file:///home/fred/data.db <br> 2952 ** file://localhost/home/fred/data.db <br> <td> 2953 ** Open the database file "/home/fred/data.db". 2954 ** <tr><td> file://darkstar/home/fred/data.db <td> 2955 ** An error. "darkstar" is not a recognized authority. 2956 ** <tr><td style="white-space:nowrap"> 2957 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 2958 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 2959 ** C:. Note that the %20 escaping in this example is not strictly 2960 ** necessary - space characters can be used literally 2961 ** in URI filenames. 2962 ** <tr><td> file:data.db?mode=ro&cache=private <td> 2963 ** Open file "data.db" in the current directory for read-only access. 2964 ** Regardless of whether or not shared-cache mode is enabled by 2965 ** default, use a private cache. 2966 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 2967 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 2968 ** that uses dot-files in place of posix advisory locking. 2969 ** <tr><td> file:data.db?mode=readonly <td> 2970 ** An error. "readonly" is not a valid option for the "mode" parameter. 2971 ** </table> 2972 ** 2973 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 2974 ** query components of a URI. A hexadecimal escape sequence consists of a 2975 ** percent sign - "%" - followed by exactly two hexadecimal digits 2976 ** specifying an octet value. ^Before the path or query components of a 2977 ** URI filename are interpreted, they are encoded using UTF-8 and all 2978 ** hexadecimal escape sequences replaced by a single byte containing the 2979 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 2980 ** the results are undefined. 2981 ** 2982 ** <b>Note to Windows users:</b> The encoding used for the filename argument 2983 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2984 ** codepage is currently defined. Filenames containing international 2985 ** characters must be converted to UTF-8 prior to passing them into 2986 ** sqlite3_open() or sqlite3_open_v2(). 2987 ** 2988 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 2989 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 2990 ** features that require the use of temporary files may fail. 2991 ** 2992 ** See also: [sqlite3_temp_directory] 2993 */ 2994 SQLITE_API int SQLITE_STDCALL sqlite3_open( 2995 const char *filename, /* Database filename (UTF-8) */ 2996 sqlite3 **ppDb /* OUT: SQLite db handle */ 2997 ); 2998 SQLITE_API int SQLITE_STDCALL sqlite3_open16( 2999 const void *filename, /* Database filename (UTF-16) */ 3000 sqlite3 **ppDb /* OUT: SQLite db handle */ 3001 ); 3002 SQLITE_API int SQLITE_STDCALL sqlite3_open_v2( 3003 const char *filename, /* Database filename (UTF-8) */ 3004 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3005 int flags, /* Flags */ 3006 const char *zVfs /* Name of VFS module to use */ 3007 ); 3008 3009 /* 3010 ** CAPI3REF: Obtain Values For URI Parameters 3011 ** 3012 ** These are utility routines, useful to VFS implementations, that check 3013 ** to see if a database file was a URI that contained a specific query 3014 ** parameter, and if so obtains the value of that query parameter. 3015 ** 3016 ** If F is the database filename pointer passed into the xOpen() method of 3017 ** a VFS implementation when the flags parameter to xOpen() has one or 3018 ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3019 ** P is the name of the query parameter, then 3020 ** sqlite3_uri_parameter(F,P) returns the value of the P 3021 ** parameter if it exists or a NULL pointer if P does not appear as a 3022 ** query parameter on F. If P is a query parameter of F 3023 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3024 ** a pointer to an empty string. 3025 ** 3026 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3027 ** parameter and returns true (1) or false (0) according to the value 3028 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3029 ** value of query parameter P is one of "yes", "true", or "on" in any 3030 ** case or if the value begins with a non-zero number. The 3031 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3032 ** query parameter P is one of "no", "false", or "off" in any case or 3033 ** if the value begins with a numeric zero. If P is not a query 3034 ** parameter on F or if the value of P is does not match any of the 3035 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3036 ** 3037 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3038 ** 64-bit signed integer and returns that integer, or D if P does not 3039 ** exist. If the value of P is something other than an integer, then 3040 ** zero is returned. 3041 ** 3042 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3043 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3044 ** is not a database file pathname pointer that SQLite passed into the xOpen 3045 ** VFS method, then the behavior of this routine is undefined and probably 3046 ** undesirable. 3047 */ 3048 SQLITE_API const char *SQLITE_STDCALL sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3049 SQLITE_API int SQLITE_STDCALL sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3050 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3051 3052 3053 /* 3054 ** CAPI3REF: Error Codes And Messages 3055 ** METHOD: sqlite3 3056 ** 3057 ** ^If the most recent sqlite3_* API call associated with 3058 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3059 ** returns the numeric [result code] or [extended result code] for that 3060 ** API call. 3061 ** If the most recent API call was successful, 3062 ** then the return value from sqlite3_errcode() is undefined. 3063 ** ^The sqlite3_extended_errcode() 3064 ** interface is the same except that it always returns the 3065 ** [extended result code] even when extended result codes are 3066 ** disabled. 3067 ** 3068 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3069 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3070 ** ^(Memory to hold the error message string is managed internally. 3071 ** The application does not need to worry about freeing the result. 3072 ** However, the error string might be overwritten or deallocated by 3073 ** subsequent calls to other SQLite interface functions.)^ 3074 ** 3075 ** ^The sqlite3_errstr() interface returns the English-language text 3076 ** that describes the [result code], as UTF-8. 3077 ** ^(Memory to hold the error message string is managed internally 3078 ** and must not be freed by the application)^. 3079 ** 3080 ** When the serialized [threading mode] is in use, it might be the 3081 ** case that a second error occurs on a separate thread in between 3082 ** the time of the first error and the call to these interfaces. 3083 ** When that happens, the second error will be reported since these 3084 ** interfaces always report the most recent result. To avoid 3085 ** this, each thread can obtain exclusive use of the [database connection] D 3086 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3087 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3088 ** all calls to the interfaces listed here are completed. 3089 ** 3090 ** If an interface fails with SQLITE_MISUSE, that means the interface 3091 ** was invoked incorrectly by the application. In that case, the 3092 ** error code and message may or may not be set. 3093 */ 3094 SQLITE_API int SQLITE_STDCALL sqlite3_errcode(sqlite3 *db); 3095 SQLITE_API int SQLITE_STDCALL sqlite3_extended_errcode(sqlite3 *db); 3096 SQLITE_API const char *SQLITE_STDCALL sqlite3_errmsg(sqlite3*); 3097 SQLITE_API const void *SQLITE_STDCALL sqlite3_errmsg16(sqlite3*); 3098 SQLITE_API const char *SQLITE_STDCALL sqlite3_errstr(int); 3099 3100 /* 3101 ** CAPI3REF: Prepared Statement Object 3102 ** KEYWORDS: {prepared statement} {prepared statements} 3103 ** 3104 ** An instance of this object represents a single SQL statement that 3105 ** has been compiled into binary form and is ready to be evaluated. 3106 ** 3107 ** Think of each SQL statement as a separate computer program. The 3108 ** original SQL text is source code. A prepared statement object 3109 ** is the compiled object code. All SQL must be converted into a 3110 ** prepared statement before it can be run. 3111 ** 3112 ** The life-cycle of a prepared statement object usually goes like this: 3113 ** 3114 ** <ol> 3115 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3116 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 3117 ** interfaces. 3118 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3119 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3120 ** to step 2. Do this zero or more times. 3121 ** <li> Destroy the object using [sqlite3_finalize()]. 3122 ** </ol> 3123 */ 3124 typedef struct sqlite3_stmt sqlite3_stmt; 3125 3126 /* 3127 ** CAPI3REF: Run-time Limits 3128 ** METHOD: sqlite3 3129 ** 3130 ** ^(This interface allows the size of various constructs to be limited 3131 ** on a connection by connection basis. The first parameter is the 3132 ** [database connection] whose limit is to be set or queried. The 3133 ** second parameter is one of the [limit categories] that define a 3134 ** class of constructs to be size limited. The third parameter is the 3135 ** new limit for that construct.)^ 3136 ** 3137 ** ^If the new limit is a negative number, the limit is unchanged. 3138 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3139 ** [limits | hard upper bound] 3140 ** set at compile-time by a C preprocessor macro called 3141 ** [limits | SQLITE_MAX_<i>NAME</i>]. 3142 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3143 ** ^Attempts to increase a limit above its hard upper bound are 3144 ** silently truncated to the hard upper bound. 3145 ** 3146 ** ^Regardless of whether or not the limit was changed, the 3147 ** [sqlite3_limit()] interface returns the prior value of the limit. 3148 ** ^Hence, to find the current value of a limit without changing it, 3149 ** simply invoke this interface with the third parameter set to -1. 3150 ** 3151 ** Run-time limits are intended for use in applications that manage 3152 ** both their own internal database and also databases that are controlled 3153 ** by untrusted external sources. An example application might be a 3154 ** web browser that has its own databases for storing history and 3155 ** separate databases controlled by JavaScript applications downloaded 3156 ** off the Internet. The internal databases can be given the 3157 ** large, default limits. Databases managed by external sources can 3158 ** be given much smaller limits designed to prevent a denial of service 3159 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3160 ** interface to further control untrusted SQL. The size of the database 3161 ** created by an untrusted script can be contained using the 3162 ** [max_page_count] [PRAGMA]. 3163 ** 3164 ** New run-time limit categories may be added in future releases. 3165 */ 3166 SQLITE_API int SQLITE_STDCALL sqlite3_limit(sqlite3*, int id, int newVal); 3167 3168 /* 3169 ** CAPI3REF: Run-Time Limit Categories 3170 ** KEYWORDS: {limit category} {*limit categories} 3171 ** 3172 ** These constants define various performance limits 3173 ** that can be lowered at run-time using [sqlite3_limit()]. 3174 ** The synopsis of the meanings of the various limits is shown below. 3175 ** Additional information is available at [limits | Limits in SQLite]. 3176 ** 3177 ** <dl> 3178 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3179 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3180 ** 3181 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3182 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3183 ** 3184 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3185 ** <dd>The maximum number of columns in a table definition or in the 3186 ** result set of a [SELECT] or the maximum number of columns in an index 3187 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 3188 ** 3189 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3190 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3191 ** 3192 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3193 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3194 ** 3195 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3196 ** <dd>The maximum number of instructions in a virtual machine program 3197 ** used to implement an SQL statement. This limit is not currently 3198 ** enforced, though that might be added in some future release of 3199 ** SQLite.</dd>)^ 3200 ** 3201 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3202 ** <dd>The maximum number of arguments on a function.</dd>)^ 3203 ** 3204 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3205 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3206 ** 3207 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3208 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3209 ** <dd>The maximum length of the pattern argument to the [LIKE] or 3210 ** [GLOB] operators.</dd>)^ 3211 ** 3212 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3213 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3214 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3215 ** 3216 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3217 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 3218 ** 3219 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3220 ** <dd>The maximum number of auxiliary worker threads that a single 3221 ** [prepared statement] may start.</dd>)^ 3222 ** </dl> 3223 */ 3224 #define SQLITE_LIMIT_LENGTH 0 3225 #define SQLITE_LIMIT_SQL_LENGTH 1 3226 #define SQLITE_LIMIT_COLUMN 2 3227 #define SQLITE_LIMIT_EXPR_DEPTH 3 3228 #define SQLITE_LIMIT_COMPOUND_SELECT 4 3229 #define SQLITE_LIMIT_VDBE_OP 5 3230 #define SQLITE_LIMIT_FUNCTION_ARG 6 3231 #define SQLITE_LIMIT_ATTACHED 7 3232 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3233 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 3234 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 3235 #define SQLITE_LIMIT_WORKER_THREADS 11 3236 3237 /* 3238 ** CAPI3REF: Compiling An SQL Statement 3239 ** KEYWORDS: {SQL statement compiler} 3240 ** METHOD: sqlite3 3241 ** CONSTRUCTOR: sqlite3_stmt 3242 ** 3243 ** To execute an SQL query, it must first be compiled into a byte-code 3244 ** program using one of these routines. 3245 ** 3246 ** The first argument, "db", is a [database connection] obtained from a 3247 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3248 ** [sqlite3_open16()]. The database connection must not have been closed. 3249 ** 3250 ** The second argument, "zSql", is the statement to be compiled, encoded 3251 ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3252 ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3253 ** use UTF-16. 3254 ** 3255 ** ^If the nByte argument is negative, then zSql is read up to the 3256 ** first zero terminator. ^If nByte is positive, then it is the 3257 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 3258 ** statement is generated. 3259 ** If the caller knows that the supplied string is nul-terminated, then 3260 ** there is a small performance advantage to passing an nByte parameter that 3261 ** is the number of bytes in the input string <i>including</i> 3262 ** the nul-terminator. 3263 ** 3264 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3265 ** past the end of the first SQL statement in zSql. These routines only 3266 ** compile the first statement in zSql, so *pzTail is left pointing to 3267 ** what remains uncompiled. 3268 ** 3269 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3270 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3271 ** to NULL. ^If the input text contains no SQL (if the input is an empty 3272 ** string or a comment) then *ppStmt is set to NULL. 3273 ** The calling procedure is responsible for deleting the compiled 3274 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 3275 ** ppStmt may not be NULL. 3276 ** 3277 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3278 ** otherwise an [error code] is returned. 3279 ** 3280 ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3281 ** recommended for all new programs. The two older interfaces are retained 3282 ** for backwards compatibility, but their use is discouraged. 3283 ** ^In the "v2" interfaces, the prepared statement 3284 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 3285 ** original SQL text. This causes the [sqlite3_step()] interface to 3286 ** behave differently in three ways: 3287 ** 3288 ** <ol> 3289 ** <li> 3290 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3291 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 3292 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3293 ** retries will occur before sqlite3_step() gives up and returns an error. 3294 ** </li> 3295 ** 3296 ** <li> 3297 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3298 ** [error codes] or [extended error codes]. ^The legacy behavior was that 3299 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3300 ** and the application would have to make a second call to [sqlite3_reset()] 3301 ** in order to find the underlying cause of the problem. With the "v2" prepare 3302 ** interfaces, the underlying reason for the error is returned immediately. 3303 ** </li> 3304 ** 3305 ** <li> 3306 ** ^If the specific value bound to [parameter | host parameter] in the 3307 ** WHERE clause might influence the choice of query plan for a statement, 3308 ** then the statement will be automatically recompiled, as if there had been 3309 ** a schema change, on the first [sqlite3_step()] call following any change 3310 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 3311 ** ^The specific value of WHERE-clause [parameter] might influence the 3312 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 3313 ** or [GLOB] operator or if the parameter is compared to an indexed column 3314 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3315 ** </li> 3316 ** </ol> 3317 */ 3318 SQLITE_API int SQLITE_STDCALL sqlite3_prepare( 3319 sqlite3 *db, /* Database handle */ 3320 const char *zSql, /* SQL statement, UTF-8 encoded */ 3321 int nByte, /* Maximum length of zSql in bytes. */ 3322 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3323 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3324 ); 3325 SQLITE_API int SQLITE_STDCALL sqlite3_prepare_v2( 3326 sqlite3 *db, /* Database handle */ 3327 const char *zSql, /* SQL statement, UTF-8 encoded */ 3328 int nByte, /* Maximum length of zSql in bytes. */ 3329 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3330 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3331 ); 3332 SQLITE_API int SQLITE_STDCALL sqlite3_prepare16( 3333 sqlite3 *db, /* Database handle */ 3334 const void *zSql, /* SQL statement, UTF-16 encoded */ 3335 int nByte, /* Maximum length of zSql in bytes. */ 3336 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3337 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3338 ); 3339 SQLITE_API int SQLITE_STDCALL sqlite3_prepare16_v2( 3340 sqlite3 *db, /* Database handle */ 3341 const void *zSql, /* SQL statement, UTF-16 encoded */ 3342 int nByte, /* Maximum length of zSql in bytes. */ 3343 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3344 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3345 ); 3346 3347 /* 3348 ** CAPI3REF: Retrieving Statement SQL 3349 ** METHOD: sqlite3_stmt 3350 ** 3351 ** ^This interface can be used to retrieve a saved copy of the original 3352 ** SQL text used to create a [prepared statement] if that statement was 3353 ** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3354 */ 3355 SQLITE_API const char *SQLITE_STDCALL sqlite3_sql(sqlite3_stmt *pStmt); 3356 3357 /* 3358 ** CAPI3REF: Determine If An SQL Statement Writes The Database 3359 ** METHOD: sqlite3_stmt 3360 ** 3361 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3362 ** and only if the [prepared statement] X makes no direct changes to 3363 ** the content of the database file. 3364 ** 3365 ** Note that [application-defined SQL functions] or 3366 ** [virtual tables] might change the database indirectly as a side effect. 3367 ** ^(For example, if an application defines a function "eval()" that 3368 ** calls [sqlite3_exec()], then the following SQL statement would 3369 ** change the database file through side-effects: 3370 ** 3371 ** <blockquote><pre> 3372 ** SELECT eval('DELETE FROM t1') FROM t2; 3373 ** </pre></blockquote> 3374 ** 3375 ** But because the [SELECT] statement does not change the database file 3376 ** directly, sqlite3_stmt_readonly() would still return true.)^ 3377 ** 3378 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3379 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3380 ** since the statements themselves do not actually modify the database but 3381 ** rather they control the timing of when other statements modify the 3382 ** database. ^The [ATTACH] and [DETACH] statements also cause 3383 ** sqlite3_stmt_readonly() to return true since, while those statements 3384 ** change the configuration of a database connection, they do not make 3385 ** changes to the content of the database files on disk. 3386 */ 3387 SQLITE_API int SQLITE_STDCALL sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3388 3389 /* 3390 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3391 ** METHOD: sqlite3_stmt 3392 ** 3393 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3394 ** [prepared statement] S has been stepped at least once using 3395 ** [sqlite3_step(S)] but has neither run to completion (returned 3396 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3397 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3398 ** interface returns false if S is a NULL pointer. If S is not a 3399 ** NULL pointer and is not a pointer to a valid [prepared statement] 3400 ** object, then the behavior is undefined and probably undesirable. 3401 ** 3402 ** This interface can be used in combination [sqlite3_next_stmt()] 3403 ** to locate all prepared statements associated with a database 3404 ** connection that are in need of being reset. This can be used, 3405 ** for example, in diagnostic routines to search for prepared 3406 ** statements that are holding a transaction open. 3407 */ 3408 SQLITE_API int SQLITE_STDCALL sqlite3_stmt_busy(sqlite3_stmt*); 3409 3410 /* 3411 ** CAPI3REF: Dynamically Typed Value Object 3412 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3413 ** 3414 ** SQLite uses the sqlite3_value object to represent all values 3415 ** that can be stored in a database table. SQLite uses dynamic typing 3416 ** for the values it stores. ^Values stored in sqlite3_value objects 3417 ** can be integers, floating point values, strings, BLOBs, or NULL. 3418 ** 3419 ** An sqlite3_value object may be either "protected" or "unprotected". 3420 ** Some interfaces require a protected sqlite3_value. Other interfaces 3421 ** will accept either a protected or an unprotected sqlite3_value. 3422 ** Every interface that accepts sqlite3_value arguments specifies 3423 ** whether or not it requires a protected sqlite3_value. The 3424 ** [sqlite3_value_dup()] interface can be used to construct a new 3425 ** protected sqlite3_value from an unprotected sqlite3_value. 3426 ** 3427 ** The terms "protected" and "unprotected" refer to whether or not 3428 ** a mutex is held. An internal mutex is held for a protected 3429 ** sqlite3_value object but no mutex is held for an unprotected 3430 ** sqlite3_value object. If SQLite is compiled to be single-threaded 3431 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3432 ** or if SQLite is run in one of reduced mutex modes 3433 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3434 ** then there is no distinction between protected and unprotected 3435 ** sqlite3_value objects and they can be used interchangeably. However, 3436 ** for maximum code portability it is recommended that applications 3437 ** still make the distinction between protected and unprotected 3438 ** sqlite3_value objects even when not strictly required. 3439 ** 3440 ** ^The sqlite3_value objects that are passed as parameters into the 3441 ** implementation of [application-defined SQL functions] are protected. 3442 ** ^The sqlite3_value object returned by 3443 ** [sqlite3_column_value()] is unprotected. 3444 ** Unprotected sqlite3_value objects may only be used with 3445 ** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3446 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 3447 ** interfaces require protected sqlite3_value objects. 3448 */ 3449 typedef struct Mem sqlite3_value; 3450 3451 /* 3452 ** CAPI3REF: SQL Function Context Object 3453 ** 3454 ** The context in which an SQL function executes is stored in an 3455 ** sqlite3_context object. ^A pointer to an sqlite3_context object 3456 ** is always first parameter to [application-defined SQL functions]. 3457 ** The application-defined SQL function implementation will pass this 3458 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3459 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3460 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3461 ** and/or [sqlite3_set_auxdata()]. 3462 */ 3463 typedef struct sqlite3_context sqlite3_context; 3464 3465 /* 3466 ** CAPI3REF: Binding Values To Prepared Statements 3467 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3468 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3469 ** METHOD: sqlite3_stmt 3470 ** 3471 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3472 ** literals may be replaced by a [parameter] that matches one of following 3473 ** templates: 3474 ** 3475 ** <ul> 3476 ** <li> ? 3477 ** <li> ?NNN 3478 ** <li> :VVV 3479 ** <li> @VVV 3480 ** <li> $VVV 3481 ** </ul> 3482 ** 3483 ** In the templates above, NNN represents an integer literal, 3484 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 3485 ** parameters (also called "host parameter names" or "SQL parameters") 3486 ** can be set using the sqlite3_bind_*() routines defined here. 3487 ** 3488 ** ^The first argument to the sqlite3_bind_*() routines is always 3489 ** a pointer to the [sqlite3_stmt] object returned from 3490 ** [sqlite3_prepare_v2()] or its variants. 3491 ** 3492 ** ^The second argument is the index of the SQL parameter to be set. 3493 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 3494 ** SQL parameter is used more than once, second and subsequent 3495 ** occurrences have the same index as the first occurrence. 3496 ** ^The index for named parameters can be looked up using the 3497 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 3498 ** for "?NNN" parameters is the value of NNN. 3499 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 3500 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3501 ** 3502 ** ^The third argument is the value to bind to the parameter. 3503 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3504 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3505 ** is ignored and the end result is the same as sqlite3_bind_null(). 3506 ** 3507 ** ^(In those routines that have a fourth argument, its value is the 3508 ** number of bytes in the parameter. To be clear: the value is the 3509 ** number of <u>bytes</u> in the value, not the number of characters.)^ 3510 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3511 ** is negative, then the length of the string is 3512 ** the number of bytes up to the first zero terminator. 3513 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 3514 ** the behavior is undefined. 3515 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3516 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3517 ** that parameter must be the byte offset 3518 ** where the NUL terminator would occur assuming the string were NUL 3519 ** terminated. If any NUL characters occur at byte offsets less than 3520 ** the value of the fourth parameter then the resulting string value will 3521 ** contain embedded NULs. The result of expressions involving strings 3522 ** with embedded NULs is undefined. 3523 ** 3524 ** ^The fifth argument to the BLOB and string binding interfaces 3525 ** is a destructor used to dispose of the BLOB or 3526 ** string after SQLite has finished with it. ^The destructor is called 3527 ** to dispose of the BLOB or string even if the call to bind API fails. 3528 ** ^If the fifth argument is 3529 ** the special value [SQLITE_STATIC], then SQLite assumes that the 3530 ** information is in static, unmanaged space and does not need to be freed. 3531 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3532 ** SQLite makes its own private copy of the data immediately, before 3533 ** the sqlite3_bind_*() routine returns. 3534 ** 3535 ** ^The sixth argument to sqlite3_bind_text64() must be one of 3536 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3537 ** to specify the encoding of the text in the third parameter. If 3538 ** the sixth argument to sqlite3_bind_text64() is not one of the 3539 ** allowed values shown above, or if the text encoding is different 3540 ** from the encoding specified by the sixth parameter, then the behavior 3541 ** is undefined. 3542 ** 3543 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3544 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3545 ** (just an integer to hold its size) while it is being processed. 3546 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 3547 ** content is later written using 3548 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 3549 ** ^A negative value for the zeroblob results in a zero-length BLOB. 3550 ** 3551 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3552 ** for the [prepared statement] or with a prepared statement for which 3553 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3554 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3555 ** routine is passed a [prepared statement] that has been finalized, the 3556 ** result is undefined and probably harmful. 3557 ** 3558 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3559 ** ^Unbound parameters are interpreted as NULL. 3560 ** 3561 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3562 ** [error code] if anything goes wrong. 3563 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 3564 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 3565 ** [SQLITE_MAX_LENGTH]. 3566 ** ^[SQLITE_RANGE] is returned if the parameter 3567 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3568 ** 3569 ** See also: [sqlite3_bind_parameter_count()], 3570 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3571 */ 3572 SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3573 SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 3574 void(*)(void*)); 3575 SQLITE_API int SQLITE_STDCALL sqlite3_bind_double(sqlite3_stmt*, int, double); 3576 SQLITE_API int SQLITE_STDCALL sqlite3_bind_int(sqlite3_stmt*, int, int); 3577 SQLITE_API int SQLITE_STDCALL sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3578 SQLITE_API int SQLITE_STDCALL sqlite3_bind_null(sqlite3_stmt*, int); 3579 SQLITE_API int SQLITE_STDCALL sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 3580 SQLITE_API int SQLITE_STDCALL sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3581 SQLITE_API int SQLITE_STDCALL sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 3582 void(*)(void*), unsigned char encoding); 3583 SQLITE_API int SQLITE_STDCALL sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3584 SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3585 SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 3586 3587 /* 3588 ** CAPI3REF: Number Of SQL Parameters 3589 ** METHOD: sqlite3_stmt 3590 ** 3591 ** ^This routine can be used to find the number of [SQL parameters] 3592 ** in a [prepared statement]. SQL parameters are tokens of the 3593 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3594 ** placeholders for values that are [sqlite3_bind_blob | bound] 3595 ** to the parameters at a later time. 3596 ** 3597 ** ^(This routine actually returns the index of the largest (rightmost) 3598 ** parameter. For all forms except ?NNN, this will correspond to the 3599 ** number of unique parameters. If parameters of the ?NNN form are used, 3600 ** there may be gaps in the list.)^ 3601 ** 3602 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3603 ** [sqlite3_bind_parameter_name()], and 3604 ** [sqlite3_bind_parameter_index()]. 3605 */ 3606 SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_count(sqlite3_stmt*); 3607 3608 /* 3609 ** CAPI3REF: Name Of A Host Parameter 3610 ** METHOD: sqlite3_stmt 3611 ** 3612 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 3613 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 3614 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3615 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3616 ** respectively. 3617 ** In other words, the initial ":" or "$" or "@" or "?" 3618 ** is included as part of the name.)^ 3619 ** ^Parameters of the form "?" without a following integer have no name 3620 ** and are referred to as "nameless" or "anonymous parameters". 3621 ** 3622 ** ^The first host parameter has an index of 1, not 0. 3623 ** 3624 ** ^If the value N is out of range or if the N-th parameter is 3625 ** nameless, then NULL is returned. ^The returned string is 3626 ** always in UTF-8 encoding even if the named parameter was 3627 ** originally specified as UTF-16 in [sqlite3_prepare16()] or 3628 ** [sqlite3_prepare16_v2()]. 3629 ** 3630 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3631 ** [sqlite3_bind_parameter_count()], and 3632 ** [sqlite3_bind_parameter_index()]. 3633 */ 3634 SQLITE_API const char *SQLITE_STDCALL sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3635 3636 /* 3637 ** CAPI3REF: Index Of A Parameter With A Given Name 3638 ** METHOD: sqlite3_stmt 3639 ** 3640 ** ^Return the index of an SQL parameter given its name. ^The 3641 ** index value returned is suitable for use as the second 3642 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3643 ** is returned if no matching parameter is found. ^The parameter 3644 ** name must be given in UTF-8 even if the original statement 3645 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3646 ** 3647 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3648 ** [sqlite3_bind_parameter_count()], and 3649 ** [sqlite3_bind_parameter_name()]. 3650 */ 3651 SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3652 3653 /* 3654 ** CAPI3REF: Reset All Bindings On A Prepared Statement 3655 ** METHOD: sqlite3_stmt 3656 ** 3657 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3658 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3659 ** ^Use this routine to reset all host parameters to NULL. 3660 */ 3661 SQLITE_API int SQLITE_STDCALL sqlite3_clear_bindings(sqlite3_stmt*); 3662 3663 /* 3664 ** CAPI3REF: Number Of Columns In A Result Set 3665 ** METHOD: sqlite3_stmt 3666 ** 3667 ** ^Return the number of columns in the result set returned by the 3668 ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3669 ** statement that does not return data (for example an [UPDATE]). 3670 ** 3671 ** See also: [sqlite3_data_count()] 3672 */ 3673 SQLITE_API int SQLITE_STDCALL sqlite3_column_count(sqlite3_stmt *pStmt); 3674 3675 /* 3676 ** CAPI3REF: Column Names In A Result Set 3677 ** METHOD: sqlite3_stmt 3678 ** 3679 ** ^These routines return the name assigned to a particular column 3680 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3681 ** interface returns a pointer to a zero-terminated UTF-8 string 3682 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 3683 ** UTF-16 string. ^The first parameter is the [prepared statement] 3684 ** that implements the [SELECT] statement. ^The second parameter is the 3685 ** column number. ^The leftmost column is number 0. 3686 ** 3687 ** ^The returned string pointer is valid until either the [prepared statement] 3688 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3689 ** reprepared by the first call to [sqlite3_step()] for a particular run 3690 ** or until the next call to 3691 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3692 ** 3693 ** ^If sqlite3_malloc() fails during the processing of either routine 3694 ** (for example during a conversion from UTF-8 to UTF-16) then a 3695 ** NULL pointer is returned. 3696 ** 3697 ** ^The name of a result column is the value of the "AS" clause for 3698 ** that column, if there is an AS clause. If there is no AS clause 3699 ** then the name of the column is unspecified and may change from 3700 ** one release of SQLite to the next. 3701 */ 3702 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_name(sqlite3_stmt*, int N); 3703 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_name16(sqlite3_stmt*, int N); 3704 3705 /* 3706 ** CAPI3REF: Source Of Data In A Query Result 3707 ** METHOD: sqlite3_stmt 3708 ** 3709 ** ^These routines provide a means to determine the database, table, and 3710 ** table column that is the origin of a particular result column in 3711 ** [SELECT] statement. 3712 ** ^The name of the database or table or column can be returned as 3713 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3714 ** the database name, the _table_ routines return the table name, and 3715 ** the origin_ routines return the column name. 3716 ** ^The returned string is valid until the [prepared statement] is destroyed 3717 ** using [sqlite3_finalize()] or until the statement is automatically 3718 ** reprepared by the first call to [sqlite3_step()] for a particular run 3719 ** or until the same information is requested 3720 ** again in a different encoding. 3721 ** 3722 ** ^The names returned are the original un-aliased names of the 3723 ** database, table, and column. 3724 ** 3725 ** ^The first argument to these interfaces is a [prepared statement]. 3726 ** ^These functions return information about the Nth result column returned by 3727 ** the statement, where N is the second function argument. 3728 ** ^The left-most column is column 0 for these routines. 3729 ** 3730 ** ^If the Nth column returned by the statement is an expression or 3731 ** subquery and is not a column value, then all of these functions return 3732 ** NULL. ^These routine might also return NULL if a memory allocation error 3733 ** occurs. ^Otherwise, they return the name of the attached database, table, 3734 ** or column that query result column was extracted from. 3735 ** 3736 ** ^As with all other SQLite APIs, those whose names end with "16" return 3737 ** UTF-16 encoded strings and the other functions return UTF-8. 3738 ** 3739 ** ^These APIs are only available if the library was compiled with the 3740 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3741 ** 3742 ** If two or more threads call one or more of these routines against the same 3743 ** prepared statement and column at the same time then the results are 3744 ** undefined. 3745 ** 3746 ** If two or more threads call one or more 3747 ** [sqlite3_column_database_name | column metadata interfaces] 3748 ** for the same [prepared statement] and result column 3749 ** at the same time then the results are undefined. 3750 */ 3751 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_database_name(sqlite3_stmt*,int); 3752 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_database_name16(sqlite3_stmt*,int); 3753 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_table_name(sqlite3_stmt*,int); 3754 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_table_name16(sqlite3_stmt*,int); 3755 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_origin_name(sqlite3_stmt*,int); 3756 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_origin_name16(sqlite3_stmt*,int); 3757 3758 /* 3759 ** CAPI3REF: Declared Datatype Of A Query Result 3760 ** METHOD: sqlite3_stmt 3761 ** 3762 ** ^(The first parameter is a [prepared statement]. 3763 ** If this statement is a [SELECT] statement and the Nth column of the 3764 ** returned result set of that [SELECT] is a table column (not an 3765 ** expression or subquery) then the declared type of the table 3766 ** column is returned.)^ ^If the Nth column of the result set is an 3767 ** expression or subquery, then a NULL pointer is returned. 3768 ** ^The returned string is always UTF-8 encoded. 3769 ** 3770 ** ^(For example, given the database schema: 3771 ** 3772 ** CREATE TABLE t1(c1 VARIANT); 3773 ** 3774 ** and the following statement to be compiled: 3775 ** 3776 ** SELECT c1 + 1, c1 FROM t1; 3777 ** 3778 ** this routine would return the string "VARIANT" for the second result 3779 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3780 ** 3781 ** ^SQLite uses dynamic run-time typing. ^So just because a column 3782 ** is declared to contain a particular type does not mean that the 3783 ** data stored in that column is of the declared type. SQLite is 3784 ** strongly typed, but the typing is dynamic not static. ^Type 3785 ** is associated with individual values, not with the containers 3786 ** used to hold those values. 3787 */ 3788 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_decltype(sqlite3_stmt*,int); 3789 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_decltype16(sqlite3_stmt*,int); 3790 3791 /* 3792 ** CAPI3REF: Evaluate An SQL Statement 3793 ** METHOD: sqlite3_stmt 3794 ** 3795 ** After a [prepared statement] has been prepared using either 3796 ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3797 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3798 ** must be called one or more times to evaluate the statement. 3799 ** 3800 ** The details of the behavior of the sqlite3_step() interface depend 3801 ** on whether the statement was prepared using the newer "v2" interface 3802 ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3803 ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3804 ** new "v2" interface is recommended for new applications but the legacy 3805 ** interface will continue to be supported. 3806 ** 3807 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 3808 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3809 ** ^With the "v2" interface, any of the other [result codes] or 3810 ** [extended result codes] might be returned as well. 3811 ** 3812 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 3813 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 3814 ** or occurs outside of an explicit transaction, then you can retry the 3815 ** statement. If the statement is not a [COMMIT] and occurs within an 3816 ** explicit transaction then you should rollback the transaction before 3817 ** continuing. 3818 ** 3819 ** ^[SQLITE_DONE] means that the statement has finished executing 3820 ** successfully. sqlite3_step() should not be called again on this virtual 3821 ** machine without first calling [sqlite3_reset()] to reset the virtual 3822 ** machine back to its initial state. 3823 ** 3824 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 3825 ** is returned each time a new row of data is ready for processing by the 3826 ** caller. The values may be accessed using the [column access functions]. 3827 ** sqlite3_step() is called again to retrieve the next row of data. 3828 ** 3829 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 3830 ** violation) has occurred. sqlite3_step() should not be called again on 3831 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 3832 ** ^With the legacy interface, a more specific error code (for example, 3833 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3834 ** can be obtained by calling [sqlite3_reset()] on the 3835 ** [prepared statement]. ^In the "v2" interface, 3836 ** the more specific error code is returned directly by sqlite3_step(). 3837 ** 3838 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3839 ** Perhaps it was called on a [prepared statement] that has 3840 ** already been [sqlite3_finalize | finalized] or on one that had 3841 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3842 ** be the case that the same database connection is being used by two or 3843 ** more threads at the same moment in time. 3844 ** 3845 ** For all versions of SQLite up to and including 3.6.23.1, a call to 3846 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 3847 ** other than [SQLITE_ROW] before any subsequent invocation of 3848 ** sqlite3_step(). Failure to reset the prepared statement using 3849 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 3850 ** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 3851 ** calling [sqlite3_reset()] automatically in this circumstance rather 3852 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 3853 ** break because any application that ever receives an SQLITE_MISUSE error 3854 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 3855 ** can be used to restore the legacy behavior. 3856 ** 3857 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 3858 ** API always returns a generic error code, [SQLITE_ERROR], following any 3859 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 3860 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 3861 ** specific [error codes] that better describes the error. 3862 ** We admit that this is a goofy design. The problem has been fixed 3863 ** with the "v2" interface. If you prepare all of your SQL statements 3864 ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3865 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 3866 ** then the more specific [error codes] are returned directly 3867 ** by sqlite3_step(). The use of the "v2" interface is recommended. 3868 */ 3869 SQLITE_API int SQLITE_STDCALL sqlite3_step(sqlite3_stmt*); 3870 3871 /* 3872 ** CAPI3REF: Number of columns in a result set 3873 ** METHOD: sqlite3_stmt 3874 ** 3875 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 3876 ** current row of the result set of [prepared statement] P. 3877 ** ^If prepared statement P does not have results ready to return 3878 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 3879 ** interfaces) then sqlite3_data_count(P) returns 0. 3880 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 3881 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 3882 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 3883 ** will return non-zero if previous call to [sqlite3_step](P) returned 3884 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 3885 ** where it always returns zero since each step of that multi-step 3886 ** pragma returns 0 columns of data. 3887 ** 3888 ** See also: [sqlite3_column_count()] 3889 */ 3890 SQLITE_API int SQLITE_STDCALL sqlite3_data_count(sqlite3_stmt *pStmt); 3891 3892 /* 3893 ** CAPI3REF: Fundamental Datatypes 3894 ** KEYWORDS: SQLITE_TEXT 3895 ** 3896 ** ^(Every value in SQLite has one of five fundamental datatypes: 3897 ** 3898 ** <ul> 3899 ** <li> 64-bit signed integer 3900 ** <li> 64-bit IEEE floating point number 3901 ** <li> string 3902 ** <li> BLOB 3903 ** <li> NULL 3904 ** </ul>)^ 3905 ** 3906 ** These constants are codes for each of those types. 3907 ** 3908 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3909 ** for a completely different meaning. Software that links against both 3910 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 3911 ** SQLITE_TEXT. 3912 */ 3913 #define SQLITE_INTEGER 1 3914 #define SQLITE_FLOAT 2 3915 #define SQLITE_BLOB 4 3916 #define SQLITE_NULL 5 3917 #ifdef SQLITE_TEXT 3918 # undef SQLITE_TEXT 3919 #else 3920 # define SQLITE_TEXT 3 3921 #endif 3922 #define SQLITE3_TEXT 3 3923 3924 /* 3925 ** CAPI3REF: Result Values From A Query 3926 ** KEYWORDS: {column access functions} 3927 ** METHOD: sqlite3_stmt 3928 ** 3929 ** ^These routines return information about a single column of the current 3930 ** result row of a query. ^In every case the first argument is a pointer 3931 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 3932 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 3933 ** and the second argument is the index of the column for which information 3934 ** should be returned. ^The leftmost column of the result set has the index 0. 3935 ** ^The number of columns in the result can be determined using 3936 ** [sqlite3_column_count()]. 3937 ** 3938 ** If the SQL statement does not currently point to a valid row, or if the 3939 ** column index is out of range, the result is undefined. 3940 ** These routines may only be called when the most recent call to 3941 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3942 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 3943 ** If any of these routines are called after [sqlite3_reset()] or 3944 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3945 ** something other than [SQLITE_ROW], the results are undefined. 3946 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3947 ** are called from a different thread while any of these routines 3948 ** are pending, then the results are undefined. 3949 ** 3950 ** ^The sqlite3_column_type() routine returns the 3951 ** [SQLITE_INTEGER | datatype code] for the initial data type 3952 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 3953 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3954 ** returned by sqlite3_column_type() is only meaningful if no type 3955 ** conversions have occurred as described below. After a type conversion, 3956 ** the value returned by sqlite3_column_type() is undefined. Future 3957 ** versions of SQLite may change the behavior of sqlite3_column_type() 3958 ** following a type conversion. 3959 ** 3960 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3961 ** routine returns the number of bytes in that BLOB or string. 3962 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3963 ** the string to UTF-8 and then returns the number of bytes. 3964 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 3965 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 3966 ** the number of bytes in that string. 3967 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 3968 ** 3969 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 3970 ** routine returns the number of bytes in that BLOB or string. 3971 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 3972 ** the string to UTF-16 and then returns the number of bytes. 3973 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 3974 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 3975 ** the number of bytes in that string. 3976 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 3977 ** 3978 ** ^The values returned by [sqlite3_column_bytes()] and 3979 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 3980 ** of the string. ^For clarity: the values returned by 3981 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 3982 ** bytes in the string, not the number of characters. 3983 ** 3984 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 3985 ** even empty strings, are always zero-terminated. ^The return 3986 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 3987 ** 3988 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 3989 ** [unprotected sqlite3_value] object. In a multithreaded environment, 3990 ** an unprotected sqlite3_value object may only be used safely with 3991 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 3992 ** If the [unprotected sqlite3_value] object returned by 3993 ** [sqlite3_column_value()] is used in any other way, including calls 3994 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 3995 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 3996 ** 3997 ** These routines attempt to convert the value where appropriate. ^For 3998 ** example, if the internal representation is FLOAT and a text result 3999 ** is requested, [sqlite3_snprintf()] is used internally to perform the 4000 ** conversion automatically. ^(The following table details the conversions 4001 ** that are applied: 4002 ** 4003 ** <blockquote> 4004 ** <table border="1"> 4005 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4006 ** 4007 ** <tr><td> NULL <td> INTEGER <td> Result is 0 4008 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4009 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4010 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4011 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4012 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4013 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4014 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4015 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4016 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4017 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4018 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4019 ** <tr><td> TEXT <td> BLOB <td> No change 4020 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4021 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4022 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4023 ** </table> 4024 ** </blockquote>)^ 4025 ** 4026 ** Note that when type conversions occur, pointers returned by prior 4027 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4028 ** sqlite3_column_text16() may be invalidated. 4029 ** Type conversions and pointer invalidations might occur 4030 ** in the following cases: 4031 ** 4032 ** <ul> 4033 ** <li> The initial content is a BLOB and sqlite3_column_text() or 4034 ** sqlite3_column_text16() is called. A zero-terminator might 4035 ** need to be added to the string.</li> 4036 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4037 ** sqlite3_column_text16() is called. The content must be converted 4038 ** to UTF-16.</li> 4039 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4040 ** sqlite3_column_text() is called. The content must be converted 4041 ** to UTF-8.</li> 4042 ** </ul> 4043 ** 4044 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4045 ** not invalidate a prior pointer, though of course the content of the buffer 4046 ** that the prior pointer references will have been modified. Other kinds 4047 ** of conversion are done in place when it is possible, but sometimes they 4048 ** are not possible and in those cases prior pointers are invalidated. 4049 ** 4050 ** The safest policy is to invoke these routines 4051 ** in one of the following ways: 4052 ** 4053 ** <ul> 4054 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4055 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4056 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4057 ** </ul> 4058 ** 4059 ** In other words, you should call sqlite3_column_text(), 4060 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4061 ** into the desired format, then invoke sqlite3_column_bytes() or 4062 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4063 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4064 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4065 ** with calls to sqlite3_column_bytes(). 4066 ** 4067 ** ^The pointers returned are valid until a type conversion occurs as 4068 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4069 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4070 ** and BLOBs is freed automatically. Do <em>not</em> pass the pointers returned 4071 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4072 ** [sqlite3_free()]. 4073 ** 4074 ** ^(If a memory allocation error occurs during the evaluation of any 4075 ** of these routines, a default value is returned. The default value 4076 ** is either the integer 0, the floating point number 0.0, or a NULL 4077 ** pointer. Subsequent calls to [sqlite3_errcode()] will return 4078 ** [SQLITE_NOMEM].)^ 4079 */ 4080 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_blob(sqlite3_stmt*, int iCol); 4081 SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4082 SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4083 SQLITE_API double SQLITE_STDCALL sqlite3_column_double(sqlite3_stmt*, int iCol); 4084 SQLITE_API int SQLITE_STDCALL sqlite3_column_int(sqlite3_stmt*, int iCol); 4085 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_column_int64(sqlite3_stmt*, int iCol); 4086 SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_column_text(sqlite3_stmt*, int iCol); 4087 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_text16(sqlite3_stmt*, int iCol); 4088 SQLITE_API int SQLITE_STDCALL sqlite3_column_type(sqlite3_stmt*, int iCol); 4089 SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_column_value(sqlite3_stmt*, int iCol); 4090 4091 /* 4092 ** CAPI3REF: Destroy A Prepared Statement Object 4093 ** DESTRUCTOR: sqlite3_stmt 4094 ** 4095 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4096 ** ^If the most recent evaluation of the statement encountered no errors 4097 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 4098 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4099 ** sqlite3_finalize(S) returns the appropriate [error code] or 4100 ** [extended error code]. 4101 ** 4102 ** ^The sqlite3_finalize(S) routine can be called at any point during 4103 ** the life cycle of [prepared statement] S: 4104 ** before statement S is ever evaluated, after 4105 ** one or more calls to [sqlite3_reset()], or after any call 4106 ** to [sqlite3_step()] regardless of whether or not the statement has 4107 ** completed execution. 4108 ** 4109 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4110 ** 4111 ** The application must finalize every [prepared statement] in order to avoid 4112 ** resource leaks. It is a grievous error for the application to try to use 4113 ** a prepared statement after it has been finalized. Any use of a prepared 4114 ** statement after it has been finalized can result in undefined and 4115 ** undesirable behavior such as segfaults and heap corruption. 4116 */ 4117 SQLITE_API int SQLITE_STDCALL sqlite3_finalize(sqlite3_stmt *pStmt); 4118 4119 /* 4120 ** CAPI3REF: Reset A Prepared Statement Object 4121 ** METHOD: sqlite3_stmt 4122 ** 4123 ** The sqlite3_reset() function is called to reset a [prepared statement] 4124 ** object back to its initial state, ready to be re-executed. 4125 ** ^Any SQL statement variables that had values bound to them using 4126 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4127 ** Use [sqlite3_clear_bindings()] to reset the bindings. 4128 ** 4129 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4130 ** back to the beginning of its program. 4131 ** 4132 ** ^If the most recent call to [sqlite3_step(S)] for the 4133 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4134 ** or if [sqlite3_step(S)] has never before been called on S, 4135 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4136 ** 4137 ** ^If the most recent call to [sqlite3_step(S)] for the 4138 ** [prepared statement] S indicated an error, then 4139 ** [sqlite3_reset(S)] returns an appropriate [error code]. 4140 ** 4141 ** ^The [sqlite3_reset(S)] interface does not change the values 4142 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4143 */ 4144 SQLITE_API int SQLITE_STDCALL sqlite3_reset(sqlite3_stmt *pStmt); 4145 4146 /* 4147 ** CAPI3REF: Create Or Redefine SQL Functions 4148 ** KEYWORDS: {function creation routines} 4149 ** KEYWORDS: {application-defined SQL function} 4150 ** KEYWORDS: {application-defined SQL functions} 4151 ** METHOD: sqlite3 4152 ** 4153 ** ^These functions (collectively known as "function creation routines") 4154 ** are used to add SQL functions or aggregates or to redefine the behavior 4155 ** of existing SQL functions or aggregates. The only differences between 4156 ** these routines are the text encoding expected for 4157 ** the second parameter (the name of the function being created) 4158 ** and the presence or absence of a destructor callback for 4159 ** the application data pointer. 4160 ** 4161 ** ^The first parameter is the [database connection] to which the SQL 4162 ** function is to be added. ^If an application uses more than one database 4163 ** connection then application-defined SQL functions must be added 4164 ** to each database connection separately. 4165 ** 4166 ** ^The second parameter is the name of the SQL function to be created or 4167 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4168 ** representation, exclusive of the zero-terminator. ^Note that the name 4169 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4170 ** ^Any attempt to create a function with a longer name 4171 ** will result in [SQLITE_MISUSE] being returned. 4172 ** 4173 ** ^The third parameter (nArg) 4174 ** is the number of arguments that the SQL function or 4175 ** aggregate takes. ^If this parameter is -1, then the SQL function or 4176 ** aggregate may take any number of arguments between 0 and the limit 4177 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4178 ** parameter is less than -1 or greater than 127 then the behavior is 4179 ** undefined. 4180 ** 4181 ** ^The fourth parameter, eTextRep, specifies what 4182 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4183 ** its parameters. The application should set this parameter to 4184 ** [SQLITE_UTF16LE] if the function implementation invokes 4185 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4186 ** implementation invokes [sqlite3_value_text16be()] on an input, or 4187 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4188 ** otherwise. ^The same SQL function may be registered multiple times using 4189 ** different preferred text encodings, with different implementations for 4190 ** each encoding. 4191 ** ^When multiple implementations of the same function are available, SQLite 4192 ** will pick the one that involves the least amount of data conversion. 4193 ** 4194 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4195 ** to signal that the function will always return the same result given 4196 ** the same inputs within a single SQL statement. Most SQL functions are 4197 ** deterministic. The built-in [random()] SQL function is an example of a 4198 ** function that is not deterministic. The SQLite query planner is able to 4199 ** perform additional optimizations on deterministic functions, so use 4200 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4201 ** 4202 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4203 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 4204 ** 4205 ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4206 ** pointers to C-language functions that implement the SQL function or 4207 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4208 ** callback only; NULL pointers must be passed as the xStep and xFinal 4209 ** parameters. ^An aggregate SQL function requires an implementation of xStep 4210 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4211 ** SQL function or aggregate, pass NULL pointers for all three function 4212 ** callbacks. 4213 ** 4214 ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4215 ** then it is destructor for the application data pointer. 4216 ** The destructor is invoked when the function is deleted, either by being 4217 ** overloaded or when the database connection closes.)^ 4218 ** ^The destructor is also invoked if the call to 4219 ** sqlite3_create_function_v2() fails. 4220 ** ^When the destructor callback of the tenth parameter is invoked, it 4221 ** is passed a single argument which is a copy of the application data 4222 ** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4223 ** 4224 ** ^It is permitted to register multiple implementations of the same 4225 ** functions with the same name but with either differing numbers of 4226 ** arguments or differing preferred text encodings. ^SQLite will use 4227 ** the implementation that most closely matches the way in which the 4228 ** SQL function is used. ^A function implementation with a non-negative 4229 ** nArg parameter is a better match than a function implementation with 4230 ** a negative nArg. ^A function where the preferred text encoding 4231 ** matches the database encoding is a better 4232 ** match than a function where the encoding is different. 4233 ** ^A function where the encoding difference is between UTF16le and UTF16be 4234 ** is a closer match than a function where the encoding difference is 4235 ** between UTF8 and UTF16. 4236 ** 4237 ** ^Built-in functions may be overloaded by new application-defined functions. 4238 ** 4239 ** ^An application-defined function is permitted to call other 4240 ** SQLite interfaces. However, such calls must not 4241 ** close the database connection nor finalize or reset the prepared 4242 ** statement in which the function is running. 4243 */ 4244 SQLITE_API int SQLITE_STDCALL sqlite3_create_function( 4245 sqlite3 *db, 4246 const char *zFunctionName, 4247 int nArg, 4248 int eTextRep, 4249 void *pApp, 4250 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4251 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4252 void (*xFinal)(sqlite3_context*) 4253 ); 4254 SQLITE_API int SQLITE_STDCALL sqlite3_create_function16( 4255 sqlite3 *db, 4256 const void *zFunctionName, 4257 int nArg, 4258 int eTextRep, 4259 void *pApp, 4260 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4261 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4262 void (*xFinal)(sqlite3_context*) 4263 ); 4264 SQLITE_API int SQLITE_STDCALL sqlite3_create_function_v2( 4265 sqlite3 *db, 4266 const char *zFunctionName, 4267 int nArg, 4268 int eTextRep, 4269 void *pApp, 4270 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4271 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4272 void (*xFinal)(sqlite3_context*), 4273 void(*xDestroy)(void*) 4274 ); 4275 4276 /* 4277 ** CAPI3REF: Text Encodings 4278 ** 4279 ** These constant define integer codes that represent the various 4280 ** text encodings supported by SQLite. 4281 */ 4282 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4283 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4284 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4285 #define SQLITE_UTF16 4 /* Use native byte order */ 4286 #define SQLITE_ANY 5 /* Deprecated */ 4287 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4288 4289 /* 4290 ** CAPI3REF: Function Flags 4291 ** 4292 ** These constants may be ORed together with the 4293 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4294 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4295 ** [sqlite3_create_function_v2()]. 4296 */ 4297 #define SQLITE_DETERMINISTIC 0x800 4298 4299 /* 4300 ** CAPI3REF: Deprecated Functions 4301 ** DEPRECATED 4302 ** 4303 ** These functions are [deprecated]. In order to maintain 4304 ** backwards compatibility with older code, these functions continue 4305 ** to be supported. However, new applications should avoid 4306 ** the use of these functions. To encourage programmers to avoid 4307 ** these functions, we will not explain what they do. 4308 */ 4309 #ifndef SQLITE_OMIT_DEPRECATED 4310 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_aggregate_count(sqlite3_context*); 4311 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_expired(sqlite3_stmt*); 4312 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4313 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_global_recover(void); 4314 SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_thread_cleanup(void); 4315 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4316 void*,sqlite3_int64); 4317 #endif 4318 4319 /* 4320 ** CAPI3REF: Obtaining SQL Values 4321 ** METHOD: sqlite3_value 4322 ** 4323 ** The C-language implementation of SQL functions and aggregates uses 4324 ** this set of interface routines to access the parameter values on 4325 ** the function or aggregate. 4326 ** 4327 ** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4328 ** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4329 ** define callbacks that implement the SQL functions and aggregates. 4330 ** The 3rd parameter to these callbacks is an array of pointers to 4331 ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4332 ** each parameter to the SQL function. These routines are used to 4333 ** extract values from the [sqlite3_value] objects. 4334 ** 4335 ** These routines work only with [protected sqlite3_value] objects. 4336 ** Any attempt to use these routines on an [unprotected sqlite3_value] 4337 ** object results in undefined behavior. 4338 ** 4339 ** ^These routines work just like the corresponding [column access functions] 4340 ** except that these routines take a single [protected sqlite3_value] object 4341 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4342 ** 4343 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4344 ** in the native byte-order of the host machine. ^The 4345 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4346 ** extract UTF-16 strings as big-endian and little-endian respectively. 4347 ** 4348 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 4349 ** numeric affinity to the value. This means that an attempt is 4350 ** made to convert the value to an integer or floating point. If 4351 ** such a conversion is possible without loss of information (in other 4352 ** words, if the value is a string that looks like a number) 4353 ** then the conversion is performed. Otherwise no conversion occurs. 4354 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4355 ** 4356 ** Please pay particular attention to the fact that the pointer returned 4357 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4358 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4359 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4360 ** or [sqlite3_value_text16()]. 4361 ** 4362 ** These routines must be called from the same thread as 4363 ** the SQL function that supplied the [sqlite3_value*] parameters. 4364 */ 4365 SQLITE_API const void *SQLITE_STDCALL sqlite3_value_blob(sqlite3_value*); 4366 SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes(sqlite3_value*); 4367 SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes16(sqlite3_value*); 4368 SQLITE_API double SQLITE_STDCALL sqlite3_value_double(sqlite3_value*); 4369 SQLITE_API int SQLITE_STDCALL sqlite3_value_int(sqlite3_value*); 4370 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_value_int64(sqlite3_value*); 4371 SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_value_text(sqlite3_value*); 4372 SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16(sqlite3_value*); 4373 SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16le(sqlite3_value*); 4374 SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16be(sqlite3_value*); 4375 SQLITE_API int SQLITE_STDCALL sqlite3_value_type(sqlite3_value*); 4376 SQLITE_API int SQLITE_STDCALL sqlite3_value_numeric_type(sqlite3_value*); 4377 4378 /* 4379 ** CAPI3REF: Finding The Subtype Of SQL Values 4380 ** METHOD: sqlite3_value 4381 ** 4382 ** The sqlite3_value_subtype(V) function returns the subtype for 4383 ** an [application-defined SQL function] argument V. The subtype 4384 ** information can be used to pass a limited amount of context from 4385 ** one SQL function to another. Use the [sqlite3_result_subtype()] 4386 ** routine to set the subtype for the return value of an SQL function. 4387 ** 4388 ** SQLite makes no use of subtype itself. It merely passes the subtype 4389 ** from the result of one [application-defined SQL function] into the 4390 ** input of another. 4391 */ 4392 SQLITE_API unsigned int SQLITE_STDCALL sqlite3_value_subtype(sqlite3_value*); 4393 4394 /* 4395 ** CAPI3REF: Copy And Free SQL Values 4396 ** METHOD: sqlite3_value 4397 ** 4398 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 4399 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 4400 ** is a [protected sqlite3_value] object even if the input is not. 4401 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 4402 ** memory allocation fails. 4403 ** 4404 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 4405 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 4406 ** then sqlite3_value_free(V) is a harmless no-op. 4407 */ 4408 SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_value_dup(const sqlite3_value*); 4409 SQLITE_API void SQLITE_STDCALL sqlite3_value_free(sqlite3_value*); 4410 4411 /* 4412 ** CAPI3REF: Obtain Aggregate Function Context 4413 ** METHOD: sqlite3_context 4414 ** 4415 ** Implementations of aggregate SQL functions use this 4416 ** routine to allocate memory for storing their state. 4417 ** 4418 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4419 ** for a particular aggregate function, SQLite 4420 ** allocates N of memory, zeroes out that memory, and returns a pointer 4421 ** to the new memory. ^On second and subsequent calls to 4422 ** sqlite3_aggregate_context() for the same aggregate function instance, 4423 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 4424 ** called once for each invocation of the xStep callback and then one 4425 ** last time when the xFinal callback is invoked. ^(When no rows match 4426 ** an aggregate query, the xStep() callback of the aggregate function 4427 ** implementation is never called and xFinal() is called exactly once. 4428 ** In those cases, sqlite3_aggregate_context() might be called for the 4429 ** first time from within xFinal().)^ 4430 ** 4431 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4432 ** when first called if N is less than or equal to zero or if a memory 4433 ** allocate error occurs. 4434 ** 4435 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4436 ** determined by the N parameter on first successful call. Changing the 4437 ** value of N in subsequent call to sqlite3_aggregate_context() within 4438 ** the same aggregate function instance will not resize the memory 4439 ** allocation.)^ Within the xFinal callback, it is customary to set 4440 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4441 ** pointless memory allocations occur. 4442 ** 4443 ** ^SQLite automatically frees the memory allocated by 4444 ** sqlite3_aggregate_context() when the aggregate query concludes. 4445 ** 4446 ** The first parameter must be a copy of the 4447 ** [sqlite3_context | SQL function context] that is the first parameter 4448 ** to the xStep or xFinal callback routine that implements the aggregate 4449 ** function. 4450 ** 4451 ** This routine must be called from the same thread in which 4452 ** the aggregate SQL function is running. 4453 */ 4454 SQLITE_API void *SQLITE_STDCALL sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4455 4456 /* 4457 ** CAPI3REF: User Data For Functions 4458 ** METHOD: sqlite3_context 4459 ** 4460 ** ^The sqlite3_user_data() interface returns a copy of 4461 ** the pointer that was the pUserData parameter (the 5th parameter) 4462 ** of the [sqlite3_create_function()] 4463 ** and [sqlite3_create_function16()] routines that originally 4464 ** registered the application defined function. 4465 ** 4466 ** This routine must be called from the same thread in which 4467 ** the application-defined function is running. 4468 */ 4469 SQLITE_API void *SQLITE_STDCALL sqlite3_user_data(sqlite3_context*); 4470 4471 /* 4472 ** CAPI3REF: Database Connection For Functions 4473 ** METHOD: sqlite3_context 4474 ** 4475 ** ^The sqlite3_context_db_handle() interface returns a copy of 4476 ** the pointer to the [database connection] (the 1st parameter) 4477 ** of the [sqlite3_create_function()] 4478 ** and [sqlite3_create_function16()] routines that originally 4479 ** registered the application defined function. 4480 */ 4481 SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_context_db_handle(sqlite3_context*); 4482 4483 /* 4484 ** CAPI3REF: Function Auxiliary Data 4485 ** METHOD: sqlite3_context 4486 ** 4487 ** These functions may be used by (non-aggregate) SQL functions to 4488 ** associate metadata with argument values. If the same value is passed to 4489 ** multiple invocations of the same SQL function during query execution, under 4490 ** some circumstances the associated metadata may be preserved. An example 4491 ** of where this might be useful is in a regular-expression matching 4492 ** function. The compiled version of the regular expression can be stored as 4493 ** metadata associated with the pattern string. 4494 ** Then as long as the pattern string remains the same, 4495 ** the compiled regular expression can be reused on multiple 4496 ** invocations of the same function. 4497 ** 4498 ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4499 ** associated by the sqlite3_set_auxdata() function with the Nth argument 4500 ** value to the application-defined function. ^If there is no metadata 4501 ** associated with the function argument, this sqlite3_get_auxdata() interface 4502 ** returns a NULL pointer. 4503 ** 4504 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4505 ** argument of the application-defined function. ^Subsequent 4506 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4507 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4508 ** NULL if the metadata has been discarded. 4509 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4510 ** SQLite will invoke the destructor function X with parameter P exactly 4511 ** once, when the metadata is discarded. 4512 ** SQLite is free to discard the metadata at any time, including: <ul> 4513 ** <li> when the corresponding function parameter changes, or 4514 ** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4515 ** SQL statement, or 4516 ** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or 4517 ** <li> during the original sqlite3_set_auxdata() call when a memory 4518 ** allocation error occurs. </ul>)^ 4519 ** 4520 ** Note the last bullet in particular. The destructor X in 4521 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4522 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4523 ** should be called near the end of the function implementation and the 4524 ** function implementation should not make any use of P after 4525 ** sqlite3_set_auxdata() has been called. 4526 ** 4527 ** ^(In practice, metadata is preserved between function calls for 4528 ** function parameters that are compile-time constants, including literal 4529 ** values and [parameters] and expressions composed from the same.)^ 4530 ** 4531 ** These routines must be called from the same thread in which 4532 ** the SQL function is running. 4533 */ 4534 SQLITE_API void *SQLITE_STDCALL sqlite3_get_auxdata(sqlite3_context*, int N); 4535 SQLITE_API void SQLITE_STDCALL sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4536 4537 4538 /* 4539 ** CAPI3REF: Constants Defining Special Destructor Behavior 4540 ** 4541 ** These are special values for the destructor that is passed in as the 4542 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4543 ** argument is SQLITE_STATIC, it means that the content pointer is constant 4544 ** and will never change. It does not need to be destroyed. ^The 4545 ** SQLITE_TRANSIENT value means that the content will likely change in 4546 ** the near future and that SQLite should make its own private copy of 4547 ** the content before returning. 4548 ** 4549 ** The typedef is necessary to work around problems in certain 4550 ** C++ compilers. 4551 */ 4552 typedef void (*sqlite3_destructor_type)(void*); 4553 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 4554 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4555 4556 /* 4557 ** CAPI3REF: Setting The Result Of An SQL Function 4558 ** METHOD: sqlite3_context 4559 ** 4560 ** These routines are used by the xFunc or xFinal callbacks that 4561 ** implement SQL functions and aggregates. See 4562 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 4563 ** for additional information. 4564 ** 4565 ** These functions work very much like the [parameter binding] family of 4566 ** functions used to bind values to host parameters in prepared statements. 4567 ** Refer to the [SQL parameter] documentation for additional information. 4568 ** 4569 ** ^The sqlite3_result_blob() interface sets the result from 4570 ** an application-defined function to be the BLOB whose content is pointed 4571 ** to by the second parameter and which is N bytes long where N is the 4572 ** third parameter. 4573 ** 4574 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 4575 ** interfaces set the result of the application-defined function to be 4576 ** a BLOB containing all zero bytes and N bytes in size. 4577 ** 4578 ** ^The sqlite3_result_double() interface sets the result from 4579 ** an application-defined function to be a floating point value specified 4580 ** by its 2nd argument. 4581 ** 4582 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4583 ** cause the implemented SQL function to throw an exception. 4584 ** ^SQLite uses the string pointed to by the 4585 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4586 ** as the text of an error message. ^SQLite interprets the error 4587 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 4588 ** interprets the string from sqlite3_result_error16() as UTF-16 in native 4589 ** byte order. ^If the third parameter to sqlite3_result_error() 4590 ** or sqlite3_result_error16() is negative then SQLite takes as the error 4591 ** message all text up through the first zero character. 4592 ** ^If the third parameter to sqlite3_result_error() or 4593 ** sqlite3_result_error16() is non-negative then SQLite takes that many 4594 ** bytes (not characters) from the 2nd parameter as the error message. 4595 ** ^The sqlite3_result_error() and sqlite3_result_error16() 4596 ** routines make a private copy of the error message text before 4597 ** they return. Hence, the calling function can deallocate or 4598 ** modify the text after they return without harm. 4599 ** ^The sqlite3_result_error_code() function changes the error code 4600 ** returned by SQLite as a result of an error in a function. ^By default, 4601 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4602 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4603 ** 4604 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4605 ** error indicating that a string or BLOB is too long to represent. 4606 ** 4607 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4608 ** error indicating that a memory allocation failed. 4609 ** 4610 ** ^The sqlite3_result_int() interface sets the return value 4611 ** of the application-defined function to be the 32-bit signed integer 4612 ** value given in the 2nd argument. 4613 ** ^The sqlite3_result_int64() interface sets the return value 4614 ** of the application-defined function to be the 64-bit signed integer 4615 ** value given in the 2nd argument. 4616 ** 4617 ** ^The sqlite3_result_null() interface sets the return value 4618 ** of the application-defined function to be NULL. 4619 ** 4620 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 4621 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4622 ** set the return value of the application-defined function to be 4623 ** a text string which is represented as UTF-8, UTF-16 native byte order, 4624 ** UTF-16 little endian, or UTF-16 big endian, respectively. 4625 ** ^The sqlite3_result_text64() interface sets the return value of an 4626 ** application-defined function to be a text string in an encoding 4627 ** specified by the fifth (and last) parameter, which must be one 4628 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 4629 ** ^SQLite takes the text result from the application from 4630 ** the 2nd parameter of the sqlite3_result_text* interfaces. 4631 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4632 ** is negative, then SQLite takes result text from the 2nd parameter 4633 ** through the first zero character. 4634 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4635 ** is non-negative, then as many bytes (not characters) of the text 4636 ** pointed to by the 2nd parameter are taken as the application-defined 4637 ** function result. If the 3rd parameter is non-negative, then it 4638 ** must be the byte offset into the string where the NUL terminator would 4639 ** appear if the string where NUL terminated. If any NUL characters occur 4640 ** in the string at a byte offset that is less than the value of the 3rd 4641 ** parameter, then the resulting string will contain embedded NULs and the 4642 ** result of expressions operating on strings with embedded NULs is undefined. 4643 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 4644 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4645 ** function as the destructor on the text or BLOB result when it has 4646 ** finished using that result. 4647 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4648 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4649 ** assumes that the text or BLOB result is in constant space and does not 4650 ** copy the content of the parameter nor call a destructor on the content 4651 ** when it has finished using that result. 4652 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 4653 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4654 ** then SQLite makes a copy of the result into space obtained from 4655 ** from [sqlite3_malloc()] before it returns. 4656 ** 4657 ** ^The sqlite3_result_value() interface sets the result of 4658 ** the application-defined function to be a copy of the 4659 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4660 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4661 ** so that the [sqlite3_value] specified in the parameter may change or 4662 ** be deallocated after sqlite3_result_value() returns without harm. 4663 ** ^A [protected sqlite3_value] object may always be used where an 4664 ** [unprotected sqlite3_value] object is required, so either 4665 ** kind of [sqlite3_value] object can be used with this interface. 4666 ** 4667 ** If these routines are called from within the different thread 4668 ** than the one containing the application-defined function that received 4669 ** the [sqlite3_context] pointer, the results are undefined. 4670 */ 4671 SQLITE_API void SQLITE_STDCALL sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4672 SQLITE_API void SQLITE_STDCALL sqlite3_result_blob64(sqlite3_context*,const void*, 4673 sqlite3_uint64,void(*)(void*)); 4674 SQLITE_API void SQLITE_STDCALL sqlite3_result_double(sqlite3_context*, double); 4675 SQLITE_API void SQLITE_STDCALL sqlite3_result_error(sqlite3_context*, const char*, int); 4676 SQLITE_API void SQLITE_STDCALL sqlite3_result_error16(sqlite3_context*, const void*, int); 4677 SQLITE_API void SQLITE_STDCALL sqlite3_result_error_toobig(sqlite3_context*); 4678 SQLITE_API void SQLITE_STDCALL sqlite3_result_error_nomem(sqlite3_context*); 4679 SQLITE_API void SQLITE_STDCALL sqlite3_result_error_code(sqlite3_context*, int); 4680 SQLITE_API void SQLITE_STDCALL sqlite3_result_int(sqlite3_context*, int); 4681 SQLITE_API void SQLITE_STDCALL sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4682 SQLITE_API void SQLITE_STDCALL sqlite3_result_null(sqlite3_context*); 4683 SQLITE_API void SQLITE_STDCALL sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4684 SQLITE_API void SQLITE_STDCALL sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 4685 void(*)(void*), unsigned char encoding); 4686 SQLITE_API void SQLITE_STDCALL sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4687 SQLITE_API void SQLITE_STDCALL sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4688 SQLITE_API void SQLITE_STDCALL sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4689 SQLITE_API void SQLITE_STDCALL sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4690 SQLITE_API void SQLITE_STDCALL sqlite3_result_zeroblob(sqlite3_context*, int n); 4691 SQLITE_API int SQLITE_STDCALL sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 4692 4693 4694 /* 4695 ** CAPI3REF: Setting The Subtype Of An SQL Function 4696 ** METHOD: sqlite3_context 4697 ** 4698 ** The sqlite3_result_subtype(C,T) function causes the subtype of 4699 ** the result from the [application-defined SQL function] with 4700 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 4701 ** of the subtype T are preserved in current versions of SQLite; 4702 ** higher order bits are discarded. 4703 ** The number of subtype bytes preserved by SQLite might increase 4704 ** in future releases of SQLite. 4705 */ 4706 SQLITE_API void SQLITE_STDCALL sqlite3_result_subtype(sqlite3_context*,unsigned int); 4707 4708 /* 4709 ** CAPI3REF: Define New Collating Sequences 4710 ** METHOD: sqlite3 4711 ** 4712 ** ^These functions add, remove, or modify a [collation] associated 4713 ** with the [database connection] specified as the first argument. 4714 ** 4715 ** ^The name of the collation is a UTF-8 string 4716 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4717 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4718 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4719 ** considered to be the same name. 4720 ** 4721 ** ^(The third argument (eTextRep) must be one of the constants: 4722 ** <ul> 4723 ** <li> [SQLITE_UTF8], 4724 ** <li> [SQLITE_UTF16LE], 4725 ** <li> [SQLITE_UTF16BE], 4726 ** <li> [SQLITE_UTF16], or 4727 ** <li> [SQLITE_UTF16_ALIGNED]. 4728 ** </ul>)^ 4729 ** ^The eTextRep argument determines the encoding of strings passed 4730 ** to the collating function callback, xCallback. 4731 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4732 ** force strings to be UTF16 with native byte order. 4733 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4734 ** on an even byte address. 4735 ** 4736 ** ^The fourth argument, pArg, is an application data pointer that is passed 4737 ** through as the first argument to the collating function callback. 4738 ** 4739 ** ^The fifth argument, xCallback, is a pointer to the collating function. 4740 ** ^Multiple collating functions can be registered using the same name but 4741 ** with different eTextRep parameters and SQLite will use whichever 4742 ** function requires the least amount of data transformation. 4743 ** ^If the xCallback argument is NULL then the collating function is 4744 ** deleted. ^When all collating functions having the same name are deleted, 4745 ** that collation is no longer usable. 4746 ** 4747 ** ^The collating function callback is invoked with a copy of the pArg 4748 ** application data pointer and with two strings in the encoding specified 4749 ** by the eTextRep argument. The collating function must return an 4750 ** integer that is negative, zero, or positive 4751 ** if the first string is less than, equal to, or greater than the second, 4752 ** respectively. A collating function must always return the same answer 4753 ** given the same inputs. If two or more collating functions are registered 4754 ** to the same collation name (using different eTextRep values) then all 4755 ** must give an equivalent answer when invoked with equivalent strings. 4756 ** The collating function must obey the following properties for all 4757 ** strings A, B, and C: 4758 ** 4759 ** <ol> 4760 ** <li> If A==B then B==A. 4761 ** <li> If A==B and B==C then A==C. 4762 ** <li> If A<B THEN B>A. 4763 ** <li> If A<B and B<C then A<C. 4764 ** </ol> 4765 ** 4766 ** If a collating function fails any of the above constraints and that 4767 ** collating function is registered and used, then the behavior of SQLite 4768 ** is undefined. 4769 ** 4770 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4771 ** with the addition that the xDestroy callback is invoked on pArg when 4772 ** the collating function is deleted. 4773 ** ^Collating functions are deleted when they are overridden by later 4774 ** calls to the collation creation functions or when the 4775 ** [database connection] is closed using [sqlite3_close()]. 4776 ** 4777 ** ^The xDestroy callback is <u>not</u> called if the 4778 ** sqlite3_create_collation_v2() function fails. Applications that invoke 4779 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4780 ** check the return code and dispose of the application data pointer 4781 ** themselves rather than expecting SQLite to deal with it for them. 4782 ** This is different from every other SQLite interface. The inconsistency 4783 ** is unfortunate but cannot be changed without breaking backwards 4784 ** compatibility. 4785 ** 4786 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4787 */ 4788 SQLITE_API int SQLITE_STDCALL sqlite3_create_collation( 4789 sqlite3*, 4790 const char *zName, 4791 int eTextRep, 4792 void *pArg, 4793 int(*xCompare)(void*,int,const void*,int,const void*) 4794 ); 4795 SQLITE_API int SQLITE_STDCALL sqlite3_create_collation_v2( 4796 sqlite3*, 4797 const char *zName, 4798 int eTextRep, 4799 void *pArg, 4800 int(*xCompare)(void*,int,const void*,int,const void*), 4801 void(*xDestroy)(void*) 4802 ); 4803 SQLITE_API int SQLITE_STDCALL sqlite3_create_collation16( 4804 sqlite3*, 4805 const void *zName, 4806 int eTextRep, 4807 void *pArg, 4808 int(*xCompare)(void*,int,const void*,int,const void*) 4809 ); 4810 4811 /* 4812 ** CAPI3REF: Collation Needed Callbacks 4813 ** METHOD: sqlite3 4814 ** 4815 ** ^To avoid having to register all collation sequences before a database 4816 ** can be used, a single callback function may be registered with the 4817 ** [database connection] to be invoked whenever an undefined collation 4818 ** sequence is required. 4819 ** 4820 ** ^If the function is registered using the sqlite3_collation_needed() API, 4821 ** then it is passed the names of undefined collation sequences as strings 4822 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 4823 ** the names are passed as UTF-16 in machine native byte order. 4824 ** ^A call to either function replaces the existing collation-needed callback. 4825 ** 4826 ** ^(When the callback is invoked, the first argument passed is a copy 4827 ** of the second argument to sqlite3_collation_needed() or 4828 ** sqlite3_collation_needed16(). The second argument is the database 4829 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 4830 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 4831 ** sequence function required. The fourth parameter is the name of the 4832 ** required collation sequence.)^ 4833 ** 4834 ** The callback function should register the desired collation using 4835 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4836 ** [sqlite3_create_collation_v2()]. 4837 */ 4838 SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed( 4839 sqlite3*, 4840 void*, 4841 void(*)(void*,sqlite3*,int eTextRep,const char*) 4842 ); 4843 SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed16( 4844 sqlite3*, 4845 void*, 4846 void(*)(void*,sqlite3*,int eTextRep,const void*) 4847 ); 4848 4849 #ifdef SQLITE_HAS_CODEC 4850 /* 4851 ** Specify the key for an encrypted database. This routine should be 4852 ** called right after sqlite3_open(). 4853 ** 4854 ** The code to implement this API is not available in the public release 4855 ** of SQLite. 4856 */ 4857 SQLITE_API int SQLITE_STDCALL sqlite3_key( 4858 sqlite3 *db, /* Database to be rekeyed */ 4859 const void *pKey, int nKey /* The key */ 4860 ); 4861 SQLITE_API int SQLITE_STDCALL sqlite3_key_v2( 4862 sqlite3 *db, /* Database to be rekeyed */ 4863 const char *zDbName, /* Name of the database */ 4864 const void *pKey, int nKey /* The key */ 4865 ); 4866 4867 /* 4868 ** Change the key on an open database. If the current database is not 4869 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4870 ** database is decrypted. 4871 ** 4872 ** The code to implement this API is not available in the public release 4873 ** of SQLite. 4874 */ 4875 SQLITE_API int SQLITE_STDCALL sqlite3_rekey( 4876 sqlite3 *db, /* Database to be rekeyed */ 4877 const void *pKey, int nKey /* The new key */ 4878 ); 4879 SQLITE_API int SQLITE_STDCALL sqlite3_rekey_v2( 4880 sqlite3 *db, /* Database to be rekeyed */ 4881 const char *zDbName, /* Name of the database */ 4882 const void *pKey, int nKey /* The new key */ 4883 ); 4884 4885 /* 4886 ** Specify the activation key for a SEE database. Unless 4887 ** activated, none of the SEE routines will work. 4888 */ 4889 SQLITE_API void SQLITE_STDCALL sqlite3_activate_see( 4890 const char *zPassPhrase /* Activation phrase */ 4891 ); 4892 #endif 4893 4894 #ifdef SQLITE_ENABLE_CEROD 4895 /* 4896 ** Specify the activation key for a CEROD database. Unless 4897 ** activated, none of the CEROD routines will work. 4898 */ 4899 SQLITE_API void SQLITE_STDCALL sqlite3_activate_cerod( 4900 const char *zPassPhrase /* Activation phrase */ 4901 ); 4902 #endif 4903 4904 /* 4905 ** CAPI3REF: Suspend Execution For A Short Time 4906 ** 4907 ** The sqlite3_sleep() function causes the current thread to suspend execution 4908 ** for at least a number of milliseconds specified in its parameter. 4909 ** 4910 ** If the operating system does not support sleep requests with 4911 ** millisecond time resolution, then the time will be rounded up to 4912 ** the nearest second. The number of milliseconds of sleep actually 4913 ** requested from the operating system is returned. 4914 ** 4915 ** ^SQLite implements this interface by calling the xSleep() 4916 ** method of the default [sqlite3_vfs] object. If the xSleep() method 4917 ** of the default VFS is not implemented correctly, or not implemented at 4918 ** all, then the behavior of sqlite3_sleep() may deviate from the description 4919 ** in the previous paragraphs. 4920 */ 4921 SQLITE_API int SQLITE_STDCALL sqlite3_sleep(int); 4922 4923 /* 4924 ** CAPI3REF: Name Of The Folder Holding Temporary Files 4925 ** 4926 ** ^(If this global variable is made to point to a string which is 4927 ** the name of a folder (a.k.a. directory), then all temporary files 4928 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 4929 ** will be placed in that directory.)^ ^If this variable 4930 ** is a NULL pointer, then SQLite performs a search for an appropriate 4931 ** temporary file directory. 4932 ** 4933 ** Applications are strongly discouraged from using this global variable. 4934 ** It is required to set a temporary folder on Windows Runtime (WinRT). 4935 ** But for all other platforms, it is highly recommended that applications 4936 ** neither read nor write this variable. This global variable is a relic 4937 ** that exists for backwards compatibility of legacy applications and should 4938 ** be avoided in new projects. 4939 ** 4940 ** It is not safe to read or modify this variable in more than one 4941 ** thread at a time. It is not safe to read or modify this variable 4942 ** if a [database connection] is being used at the same time in a separate 4943 ** thread. 4944 ** It is intended that this variable be set once 4945 ** as part of process initialization and before any SQLite interface 4946 ** routines have been called and that this variable remain unchanged 4947 ** thereafter. 4948 ** 4949 ** ^The [temp_store_directory pragma] may modify this variable and cause 4950 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4951 ** the [temp_store_directory pragma] always assumes that any string 4952 ** that this variable points to is held in memory obtained from 4953 ** [sqlite3_malloc] and the pragma may attempt to free that memory 4954 ** using [sqlite3_free]. 4955 ** Hence, if this variable is modified directly, either it should be 4956 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 4957 ** or else the use of the [temp_store_directory pragma] should be avoided. 4958 ** Except when requested by the [temp_store_directory pragma], SQLite 4959 ** does not free the memory that sqlite3_temp_directory points to. If 4960 ** the application wants that memory to be freed, it must do 4961 ** so itself, taking care to only do so after all [database connection] 4962 ** objects have been destroyed. 4963 ** 4964 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 4965 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 4966 ** features that require the use of temporary files may fail. Here is an 4967 ** example of how to do this using C++ with the Windows Runtime: 4968 ** 4969 ** <blockquote><pre> 4970 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 4971 ** TemporaryFolder->Path->Data(); 4972 ** char zPathBuf[MAX_PATH + 1]; 4973 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 4974 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 4975 ** NULL, NULL); 4976 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 4977 ** </pre></blockquote> 4978 */ 4979 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 4980 4981 /* 4982 ** CAPI3REF: Name Of The Folder Holding Database Files 4983 ** 4984 ** ^(If this global variable is made to point to a string which is 4985 ** the name of a folder (a.k.a. directory), then all database files 4986 ** specified with a relative pathname and created or accessed by 4987 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 4988 ** to be relative to that directory.)^ ^If this variable is a NULL 4989 ** pointer, then SQLite assumes that all database files specified 4990 ** with a relative pathname are relative to the current directory 4991 ** for the process. Only the windows VFS makes use of this global 4992 ** variable; it is ignored by the unix VFS. 4993 ** 4994 ** Changing the value of this variable while a database connection is 4995 ** open can result in a corrupt database. 4996 ** 4997 ** It is not safe to read or modify this variable in more than one 4998 ** thread at a time. It is not safe to read or modify this variable 4999 ** if a [database connection] is being used at the same time in a separate 5000 ** thread. 5001 ** It is intended that this variable be set once 5002 ** as part of process initialization and before any SQLite interface 5003 ** routines have been called and that this variable remain unchanged 5004 ** thereafter. 5005 ** 5006 ** ^The [data_store_directory pragma] may modify this variable and cause 5007 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5008 ** the [data_store_directory pragma] always assumes that any string 5009 ** that this variable points to is held in memory obtained from 5010 ** [sqlite3_malloc] and the pragma may attempt to free that memory 5011 ** using [sqlite3_free]. 5012 ** Hence, if this variable is modified directly, either it should be 5013 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5014 ** or else the use of the [data_store_directory pragma] should be avoided. 5015 */ 5016 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 5017 5018 /* 5019 ** CAPI3REF: Test For Auto-Commit Mode 5020 ** KEYWORDS: {autocommit mode} 5021 ** METHOD: sqlite3 5022 ** 5023 ** ^The sqlite3_get_autocommit() interface returns non-zero or 5024 ** zero if the given database connection is or is not in autocommit mode, 5025 ** respectively. ^Autocommit mode is on by default. 5026 ** ^Autocommit mode is disabled by a [BEGIN] statement. 5027 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5028 ** 5029 ** If certain kinds of errors occur on a statement within a multi-statement 5030 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5031 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5032 ** transaction might be rolled back automatically. The only way to 5033 ** find out whether SQLite automatically rolled back the transaction after 5034 ** an error is to use this function. 5035 ** 5036 ** If another thread changes the autocommit status of the database 5037 ** connection while this routine is running, then the return value 5038 ** is undefined. 5039 */ 5040 SQLITE_API int SQLITE_STDCALL sqlite3_get_autocommit(sqlite3*); 5041 5042 /* 5043 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 5044 ** METHOD: sqlite3_stmt 5045 ** 5046 ** ^The sqlite3_db_handle interface returns the [database connection] handle 5047 ** to which a [prepared statement] belongs. ^The [database connection] 5048 ** returned by sqlite3_db_handle is the same [database connection] 5049 ** that was the first argument 5050 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5051 ** create the statement in the first place. 5052 */ 5053 SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_db_handle(sqlite3_stmt*); 5054 5055 /* 5056 ** CAPI3REF: Return The Filename For A Database Connection 5057 ** METHOD: sqlite3 5058 ** 5059 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5060 ** associated with database N of connection D. ^The main database file 5061 ** has the name "main". If there is no attached database N on the database 5062 ** connection D, or if database N is a temporary or in-memory database, then 5063 ** a NULL pointer is returned. 5064 ** 5065 ** ^The filename returned by this function is the output of the 5066 ** xFullPathname method of the [VFS]. ^In other words, the filename 5067 ** will be an absolute pathname, even if the filename used 5068 ** to open the database originally was a URI or relative pathname. 5069 */ 5070 SQLITE_API const char *SQLITE_STDCALL sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5071 5072 /* 5073 ** CAPI3REF: Determine if a database is read-only 5074 ** METHOD: sqlite3 5075 ** 5076 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5077 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5078 ** the name of a database on connection D. 5079 */ 5080 SQLITE_API int SQLITE_STDCALL sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5081 5082 /* 5083 ** CAPI3REF: Find the next prepared statement 5084 ** METHOD: sqlite3 5085 ** 5086 ** ^This interface returns a pointer to the next [prepared statement] after 5087 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5088 ** then this interface returns a pointer to the first prepared statement 5089 ** associated with the database connection pDb. ^If no prepared statement 5090 ** satisfies the conditions of this routine, it returns NULL. 5091 ** 5092 ** The [database connection] pointer D in a call to 5093 ** [sqlite3_next_stmt(D,S)] must refer to an open database 5094 ** connection and in particular must not be a NULL pointer. 5095 */ 5096 SQLITE_API sqlite3_stmt *SQLITE_STDCALL sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5097 5098 /* 5099 ** CAPI3REF: Commit And Rollback Notification Callbacks 5100 ** METHOD: sqlite3 5101 ** 5102 ** ^The sqlite3_commit_hook() interface registers a callback 5103 ** function to be invoked whenever a transaction is [COMMIT | committed]. 5104 ** ^Any callback set by a previous call to sqlite3_commit_hook() 5105 ** for the same database connection is overridden. 5106 ** ^The sqlite3_rollback_hook() interface registers a callback 5107 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5108 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 5109 ** for the same database connection is overridden. 5110 ** ^The pArg argument is passed through to the callback. 5111 ** ^If the callback on a commit hook function returns non-zero, 5112 ** then the commit is converted into a rollback. 5113 ** 5114 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5115 ** return the P argument from the previous call of the same function 5116 ** on the same [database connection] D, or NULL for 5117 ** the first call for each function on D. 5118 ** 5119 ** The commit and rollback hook callbacks are not reentrant. 5120 ** The callback implementation must not do anything that will modify 5121 ** the database connection that invoked the callback. Any actions 5122 ** to modify the database connection must be deferred until after the 5123 ** completion of the [sqlite3_step()] call that triggered the commit 5124 ** or rollback hook in the first place. 5125 ** Note that running any other SQL statements, including SELECT statements, 5126 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5127 ** the database connections for the meaning of "modify" in this paragraph. 5128 ** 5129 ** ^Registering a NULL function disables the callback. 5130 ** 5131 ** ^When the commit hook callback routine returns zero, the [COMMIT] 5132 ** operation is allowed to continue normally. ^If the commit hook 5133 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5134 ** ^The rollback hook is invoked on a rollback that results from a commit 5135 ** hook returning non-zero, just as it would be with any other rollback. 5136 ** 5137 ** ^For the purposes of this API, a transaction is said to have been 5138 ** rolled back if an explicit "ROLLBACK" statement is executed, or 5139 ** an error or constraint causes an implicit rollback to occur. 5140 ** ^The rollback callback is not invoked if a transaction is 5141 ** automatically rolled back because the database connection is closed. 5142 ** 5143 ** See also the [sqlite3_update_hook()] interface. 5144 */ 5145 SQLITE_API void *SQLITE_STDCALL sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5146 SQLITE_API void *SQLITE_STDCALL sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5147 5148 /* 5149 ** CAPI3REF: Data Change Notification Callbacks 5150 ** METHOD: sqlite3 5151 ** 5152 ** ^The sqlite3_update_hook() interface registers a callback function 5153 ** with the [database connection] identified by the first argument 5154 ** to be invoked whenever a row is updated, inserted or deleted in 5155 ** a rowid table. 5156 ** ^Any callback set by a previous call to this function 5157 ** for the same database connection is overridden. 5158 ** 5159 ** ^The second argument is a pointer to the function to invoke when a 5160 ** row is updated, inserted or deleted in a rowid table. 5161 ** ^The first argument to the callback is a copy of the third argument 5162 ** to sqlite3_update_hook(). 5163 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5164 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 5165 ** to be invoked. 5166 ** ^The third and fourth arguments to the callback contain pointers to the 5167 ** database and table name containing the affected row. 5168 ** ^The final callback parameter is the [rowid] of the row. 5169 ** ^In the case of an update, this is the [rowid] after the update takes place. 5170 ** 5171 ** ^(The update hook is not invoked when internal system tables are 5172 ** modified (i.e. sqlite_master and sqlite_sequence).)^ 5173 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5174 ** 5175 ** ^In the current implementation, the update hook 5176 ** is not invoked when duplication rows are deleted because of an 5177 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5178 ** invoked when rows are deleted using the [truncate optimization]. 5179 ** The exceptions defined in this paragraph might change in a future 5180 ** release of SQLite. 5181 ** 5182 ** The update hook implementation must not do anything that will modify 5183 ** the database connection that invoked the update hook. Any actions 5184 ** to modify the database connection must be deferred until after the 5185 ** completion of the [sqlite3_step()] call that triggered the update hook. 5186 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5187 ** database connections for the meaning of "modify" in this paragraph. 5188 ** 5189 ** ^The sqlite3_update_hook(D,C,P) function 5190 ** returns the P argument from the previous call 5191 ** on the same [database connection] D, or NULL for 5192 ** the first call on D. 5193 ** 5194 ** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] 5195 ** interfaces. 5196 */ 5197 SQLITE_API void *SQLITE_STDCALL sqlite3_update_hook( 5198 sqlite3*, 5199 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5200 void* 5201 ); 5202 5203 /* 5204 ** CAPI3REF: Enable Or Disable Shared Pager Cache 5205 ** 5206 ** ^(This routine enables or disables the sharing of the database cache 5207 ** and schema data structures between [database connection | connections] 5208 ** to the same database. Sharing is enabled if the argument is true 5209 ** and disabled if the argument is false.)^ 5210 ** 5211 ** ^Cache sharing is enabled and disabled for an entire process. 5212 ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 5213 ** sharing was enabled or disabled for each thread separately. 5214 ** 5215 ** ^(The cache sharing mode set by this interface effects all subsequent 5216 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5217 ** Existing database connections continue use the sharing mode 5218 ** that was in effect at the time they were opened.)^ 5219 ** 5220 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5221 ** successfully. An [error code] is returned otherwise.)^ 5222 ** 5223 ** ^Shared cache is disabled by default. But this might change in 5224 ** future releases of SQLite. Applications that care about shared 5225 ** cache setting should set it explicitly. 5226 ** 5227 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5228 ** and will always return SQLITE_MISUSE. On those systems, 5229 ** shared cache mode should be enabled per-database connection via 5230 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5231 ** 5232 ** This interface is threadsafe on processors where writing a 5233 ** 32-bit integer is atomic. 5234 ** 5235 ** See Also: [SQLite Shared-Cache Mode] 5236 */ 5237 SQLITE_API int SQLITE_STDCALL sqlite3_enable_shared_cache(int); 5238 5239 /* 5240 ** CAPI3REF: Attempt To Free Heap Memory 5241 ** 5242 ** ^The sqlite3_release_memory() interface attempts to free N bytes 5243 ** of heap memory by deallocating non-essential memory allocations 5244 ** held by the database library. Memory used to cache database 5245 ** pages to improve performance is an example of non-essential memory. 5246 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 5247 ** which might be more or less than the amount requested. 5248 ** ^The sqlite3_release_memory() routine is a no-op returning zero 5249 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5250 ** 5251 ** See also: [sqlite3_db_release_memory()] 5252 */ 5253 SQLITE_API int SQLITE_STDCALL sqlite3_release_memory(int); 5254 5255 /* 5256 ** CAPI3REF: Free Memory Used By A Database Connection 5257 ** METHOD: sqlite3 5258 ** 5259 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5260 ** memory as possible from database connection D. Unlike the 5261 ** [sqlite3_release_memory()] interface, this interface is in effect even 5262 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5263 ** omitted. 5264 ** 5265 ** See also: [sqlite3_release_memory()] 5266 */ 5267 SQLITE_API int SQLITE_STDCALL sqlite3_db_release_memory(sqlite3*); 5268 5269 /* 5270 ** CAPI3REF: Impose A Limit On Heap Size 5271 ** 5272 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5273 ** soft limit on the amount of heap memory that may be allocated by SQLite. 5274 ** ^SQLite strives to keep heap memory utilization below the soft heap 5275 ** limit by reducing the number of pages held in the page cache 5276 ** as heap memory usages approaches the limit. 5277 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 5278 ** below the limit, it will exceed the limit rather than generate 5279 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5280 ** is advisory only. 5281 ** 5282 ** ^The return value from sqlite3_soft_heap_limit64() is the size of 5283 ** the soft heap limit prior to the call, or negative in the case of an 5284 ** error. ^If the argument N is negative 5285 ** then no change is made to the soft heap limit. Hence, the current 5286 ** size of the soft heap limit can be determined by invoking 5287 ** sqlite3_soft_heap_limit64() with a negative argument. 5288 ** 5289 ** ^If the argument N is zero then the soft heap limit is disabled. 5290 ** 5291 ** ^(The soft heap limit is not enforced in the current implementation 5292 ** if one or more of following conditions are true: 5293 ** 5294 ** <ul> 5295 ** <li> The soft heap limit is set to zero. 5296 ** <li> Memory accounting is disabled using a combination of the 5297 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5298 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5299 ** <li> An alternative page cache implementation is specified using 5300 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5301 ** <li> The page cache allocates from its own memory pool supplied 5302 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5303 ** from the heap. 5304 ** </ul>)^ 5305 ** 5306 ** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 5307 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5308 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5309 ** the soft heap limit is enforced on every memory allocation. Without 5310 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5311 ** when memory is allocated by the page cache. Testing suggests that because 5312 ** the page cache is the predominate memory user in SQLite, most 5313 ** applications will achieve adequate soft heap limit enforcement without 5314 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5315 ** 5316 ** The circumstances under which SQLite will enforce the soft heap limit may 5317 ** changes in future releases of SQLite. 5318 */ 5319 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_soft_heap_limit64(sqlite3_int64 N); 5320 5321 /* 5322 ** CAPI3REF: Deprecated Soft Heap Limit Interface 5323 ** DEPRECATED 5324 ** 5325 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5326 ** interface. This routine is provided for historical compatibility 5327 ** only. All new applications should use the 5328 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 5329 */ 5330 SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_soft_heap_limit(int N); 5331 5332 5333 /* 5334 ** CAPI3REF: Extract Metadata About A Column Of A Table 5335 ** METHOD: sqlite3 5336 ** 5337 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 5338 ** information about column C of table T in database D 5339 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 5340 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 5341 ** the final five arguments with appropriate values if the specified 5342 ** column exists. ^The sqlite3_table_column_metadata() interface returns 5343 ** SQLITE_ERROR and if the specified column does not exist. 5344 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 5345 ** NULL pointer, then this routine simply checks for the existance of the 5346 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 5347 ** does not. 5348 ** 5349 ** ^The column is identified by the second, third and fourth parameters to 5350 ** this function. ^(The second parameter is either the name of the database 5351 ** (i.e. "main", "temp", or an attached database) containing the specified 5352 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 5353 ** for the table using the same algorithm used by the database engine to 5354 ** resolve unqualified table references. 5355 ** 5356 ** ^The third and fourth parameters to this function are the table and column 5357 ** name of the desired column, respectively. 5358 ** 5359 ** ^Metadata is returned by writing to the memory locations passed as the 5th 5360 ** and subsequent parameters to this function. ^Any of these arguments may be 5361 ** NULL, in which case the corresponding element of metadata is omitted. 5362 ** 5363 ** ^(<blockquote> 5364 ** <table border="1"> 5365 ** <tr><th> Parameter <th> Output<br>Type <th> Description 5366 ** 5367 ** <tr><td> 5th <td> const char* <td> Data type 5368 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5369 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5370 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5371 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5372 ** </table> 5373 ** </blockquote>)^ 5374 ** 5375 ** ^The memory pointed to by the character pointers returned for the 5376 ** declaration type and collation sequence is valid until the next 5377 ** call to any SQLite API function. 5378 ** 5379 ** ^If the specified table is actually a view, an [error code] is returned. 5380 ** 5381 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 5382 ** is not a [WITHOUT ROWID] table and an 5383 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5384 ** parameters are set for the explicitly declared column. ^(If there is no 5385 ** [INTEGER PRIMARY KEY] column, then the outputs 5386 ** for the [rowid] are set as follows: 5387 ** 5388 ** <pre> 5389 ** data type: "INTEGER" 5390 ** collation sequence: "BINARY" 5391 ** not null: 0 5392 ** primary key: 1 5393 ** auto increment: 0 5394 ** </pre>)^ 5395 ** 5396 ** ^This function causes all database schemas to be read from disk and 5397 ** parsed, if that has not already been done, and returns an error if 5398 ** any errors are encountered while loading the schema. 5399 */ 5400 SQLITE_API int SQLITE_STDCALL sqlite3_table_column_metadata( 5401 sqlite3 *db, /* Connection handle */ 5402 const char *zDbName, /* Database name or NULL */ 5403 const char *zTableName, /* Table name */ 5404 const char *zColumnName, /* Column name */ 5405 char const **pzDataType, /* OUTPUT: Declared data type */ 5406 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5407 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5408 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5409 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5410 ); 5411 5412 /* 5413 ** CAPI3REF: Load An Extension 5414 ** METHOD: sqlite3 5415 ** 5416 ** ^This interface loads an SQLite extension library from the named file. 5417 ** 5418 ** ^The sqlite3_load_extension() interface attempts to load an 5419 ** [SQLite extension] library contained in the file zFile. If 5420 ** the file cannot be loaded directly, attempts are made to load 5421 ** with various operating-system specific extensions added. 5422 ** So for example, if "samplelib" cannot be loaded, then names like 5423 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5424 ** be tried also. 5425 ** 5426 ** ^The entry point is zProc. 5427 ** ^(zProc may be 0, in which case SQLite will try to come up with an 5428 ** entry point name on its own. It first tries "sqlite3_extension_init". 5429 ** If that does not work, it constructs a name "sqlite3_X_init" where the 5430 ** X is consists of the lower-case equivalent of all ASCII alphabetic 5431 ** characters in the filename from the last "/" to the first following 5432 ** "." and omitting any initial "lib".)^ 5433 ** ^The sqlite3_load_extension() interface returns 5434 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5435 ** ^If an error occurs and pzErrMsg is not 0, then the 5436 ** [sqlite3_load_extension()] interface shall attempt to 5437 ** fill *pzErrMsg with error message text stored in memory 5438 ** obtained from [sqlite3_malloc()]. The calling function 5439 ** should free this memory by calling [sqlite3_free()]. 5440 ** 5441 ** ^Extension loading must be enabled using 5442 ** [sqlite3_enable_load_extension()] prior to calling this API, 5443 ** otherwise an error will be returned. 5444 ** 5445 ** See also the [load_extension() SQL function]. 5446 */ 5447 SQLITE_API int SQLITE_STDCALL sqlite3_load_extension( 5448 sqlite3 *db, /* Load the extension into this database connection */ 5449 const char *zFile, /* Name of the shared library containing extension */ 5450 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5451 char **pzErrMsg /* Put error message here if not 0 */ 5452 ); 5453 5454 /* 5455 ** CAPI3REF: Enable Or Disable Extension Loading 5456 ** METHOD: sqlite3 5457 ** 5458 ** ^So as not to open security holes in older applications that are 5459 ** unprepared to deal with [extension loading], and as a means of disabling 5460 ** [extension loading] while evaluating user-entered SQL, the following API 5461 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5462 ** 5463 ** ^Extension loading is off by default. 5464 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5465 ** to turn extension loading on and call it with onoff==0 to turn 5466 ** it back off again. 5467 */ 5468 SQLITE_API int SQLITE_STDCALL sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5469 5470 /* 5471 ** CAPI3REF: Automatically Load Statically Linked Extensions 5472 ** 5473 ** ^This interface causes the xEntryPoint() function to be invoked for 5474 ** each new [database connection] that is created. The idea here is that 5475 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5476 ** that is to be automatically loaded into all new database connections. 5477 ** 5478 ** ^(Even though the function prototype shows that xEntryPoint() takes 5479 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 5480 ** arguments and expects and integer result as if the signature of the 5481 ** entry point where as follows: 5482 ** 5483 ** <blockquote><pre> 5484 ** int xEntryPoint( 5485 ** sqlite3 *db, 5486 ** const char **pzErrMsg, 5487 ** const struct sqlite3_api_routines *pThunk 5488 ** ); 5489 ** </pre></blockquote>)^ 5490 ** 5491 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5492 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5493 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5494 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5495 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5496 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5497 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5498 ** 5499 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5500 ** on the list of automatic extensions is a harmless no-op. ^No entry point 5501 ** will be called more than once for each database connection that is opened. 5502 ** 5503 ** See also: [sqlite3_reset_auto_extension()] 5504 ** and [sqlite3_cancel_auto_extension()] 5505 */ 5506 SQLITE_API int SQLITE_STDCALL sqlite3_auto_extension(void (*xEntryPoint)(void)); 5507 5508 /* 5509 ** CAPI3REF: Cancel Automatic Extension Loading 5510 ** 5511 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 5512 ** initialization routine X that was registered using a prior call to 5513 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 5514 ** routine returns 1 if initialization routine X was successfully 5515 ** unregistered and it returns 0 if X was not on the list of initialization 5516 ** routines. 5517 */ 5518 SQLITE_API int SQLITE_STDCALL sqlite3_cancel_auto_extension(void (*xEntryPoint)(void)); 5519 5520 /* 5521 ** CAPI3REF: Reset Automatic Extension Loading 5522 ** 5523 ** ^This interface disables all automatic extensions previously 5524 ** registered using [sqlite3_auto_extension()]. 5525 */ 5526 SQLITE_API void SQLITE_STDCALL sqlite3_reset_auto_extension(void); 5527 5528 /* 5529 ** The interface to the virtual-table mechanism is currently considered 5530 ** to be experimental. The interface might change in incompatible ways. 5531 ** If this is a problem for you, do not use the interface at this time. 5532 ** 5533 ** When the virtual-table mechanism stabilizes, we will declare the 5534 ** interface fixed, support it indefinitely, and remove this comment. 5535 */ 5536 5537 /* 5538 ** Structures used by the virtual table interface 5539 */ 5540 typedef struct sqlite3_vtab sqlite3_vtab; 5541 typedef struct sqlite3_index_info sqlite3_index_info; 5542 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5543 typedef struct sqlite3_module sqlite3_module; 5544 5545 /* 5546 ** CAPI3REF: Virtual Table Object 5547 ** KEYWORDS: sqlite3_module {virtual table module} 5548 ** 5549 ** This structure, sometimes called a "virtual table module", 5550 ** defines the implementation of a [virtual tables]. 5551 ** This structure consists mostly of methods for the module. 5552 ** 5553 ** ^A virtual table module is created by filling in a persistent 5554 ** instance of this structure and passing a pointer to that instance 5555 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5556 ** ^The registration remains valid until it is replaced by a different 5557 ** module or until the [database connection] closes. The content 5558 ** of this structure must not change while it is registered with 5559 ** any database connection. 5560 */ 5561 struct sqlite3_module { 5562 int iVersion; 5563 int (*xCreate)(sqlite3*, void *pAux, 5564 int argc, const char *const*argv, 5565 sqlite3_vtab **ppVTab, char**); 5566 int (*xConnect)(sqlite3*, void *pAux, 5567 int argc, const char *const*argv, 5568 sqlite3_vtab **ppVTab, char**); 5569 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5570 int (*xDisconnect)(sqlite3_vtab *pVTab); 5571 int (*xDestroy)(sqlite3_vtab *pVTab); 5572 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5573 int (*xClose)(sqlite3_vtab_cursor*); 5574 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5575 int argc, sqlite3_value **argv); 5576 int (*xNext)(sqlite3_vtab_cursor*); 5577 int (*xEof)(sqlite3_vtab_cursor*); 5578 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5579 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5580 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5581 int (*xBegin)(sqlite3_vtab *pVTab); 5582 int (*xSync)(sqlite3_vtab *pVTab); 5583 int (*xCommit)(sqlite3_vtab *pVTab); 5584 int (*xRollback)(sqlite3_vtab *pVTab); 5585 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5586 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5587 void **ppArg); 5588 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5589 /* The methods above are in version 1 of the sqlite_module object. Those 5590 ** below are for version 2 and greater. */ 5591 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5592 int (*xRelease)(sqlite3_vtab *pVTab, int); 5593 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5594 }; 5595 5596 /* 5597 ** CAPI3REF: Virtual Table Indexing Information 5598 ** KEYWORDS: sqlite3_index_info 5599 ** 5600 ** The sqlite3_index_info structure and its substructures is used as part 5601 ** of the [virtual table] interface to 5602 ** pass information into and receive the reply from the [xBestIndex] 5603 ** method of a [virtual table module]. The fields under **Inputs** are the 5604 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 5605 ** results into the **Outputs** fields. 5606 ** 5607 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 5608 ** 5609 ** <blockquote>column OP expr</blockquote> 5610 ** 5611 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5612 ** stored in aConstraint[].op using one of the 5613 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5614 ** ^(The index of the column is stored in 5615 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5616 ** expr on the right-hand side can be evaluated (and thus the constraint 5617 ** is usable) and false if it cannot.)^ 5618 ** 5619 ** ^The optimizer automatically inverts terms of the form "expr OP column" 5620 ** and makes other simplifications to the WHERE clause in an attempt to 5621 ** get as many WHERE clause terms into the form shown above as possible. 5622 ** ^The aConstraint[] array only reports WHERE clause terms that are 5623 ** relevant to the particular virtual table being queried. 5624 ** 5625 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5626 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 5627 ** 5628 ** The colUsed field indicates which columns of the virtual table may be 5629 ** required by the current scan. Virtual table columns are numbered from 5630 ** zero in the order in which they appear within the CREATE TABLE statement 5631 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 5632 ** the corresponding bit is set within the colUsed mask if the column may be 5633 ** required by SQLite. If the table has at least 64 columns and any column 5634 ** to the right of the first 63 is required, then bit 63 of colUsed is also 5635 ** set. In other words, column iCol may be required if the expression 5636 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 5637 ** non-zero. 5638 ** 5639 ** The [xBestIndex] method must fill aConstraintUsage[] with information 5640 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 5641 ** the right-hand side of the corresponding aConstraint[] is evaluated 5642 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5643 ** is true, then the constraint is assumed to be fully handled by the 5644 ** virtual table and is not checked again by SQLite.)^ 5645 ** 5646 ** ^The idxNum and idxPtr values are recorded and passed into the 5647 ** [xFilter] method. 5648 ** ^[sqlite3_free()] is used to free idxPtr if and only if 5649 ** needToFreeIdxPtr is true. 5650 ** 5651 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5652 ** the correct order to satisfy the ORDER BY clause so that no separate 5653 ** sorting step is required. 5654 ** 5655 ** ^The estimatedCost value is an estimate of the cost of a particular 5656 ** strategy. A cost of N indicates that the cost of the strategy is similar 5657 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 5658 ** indicates that the expense of the operation is similar to that of a 5659 ** binary search on a unique indexed field of an SQLite table with N rows. 5660 ** 5661 ** ^The estimatedRows value is an estimate of the number of rows that 5662 ** will be returned by the strategy. 5663 ** 5664 ** The xBestIndex method may optionally populate the idxFlags field with a 5665 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 5666 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 5667 ** assumes that the strategy may visit at most one row. 5668 ** 5669 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 5670 ** SQLite also assumes that if a call to the xUpdate() method is made as 5671 ** part of the same statement to delete or update a virtual table row and the 5672 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 5673 ** any database changes. In other words, if the xUpdate() returns 5674 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 5675 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 5676 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 5677 ** the xUpdate method are automatically rolled back by SQLite. 5678 ** 5679 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 5680 ** structure for SQLite version 3.8.2. If a virtual table extension is 5681 ** used with an SQLite version earlier than 3.8.2, the results of attempting 5682 ** to read or write the estimatedRows field are undefined (but are likely 5683 ** to included crashing the application). The estimatedRows field should 5684 ** therefore only be used if [sqlite3_libversion_number()] returns a 5685 ** value greater than or equal to 3008002. Similarly, the idxFlags field 5686 ** was added for version 3.9.0. It may therefore only be used if 5687 ** sqlite3_libversion_number() returns a value greater than or equal to 5688 ** 3009000. 5689 */ 5690 struct sqlite3_index_info { 5691 /* Inputs */ 5692 int nConstraint; /* Number of entries in aConstraint */ 5693 struct sqlite3_index_constraint { 5694 int iColumn; /* Column on left-hand side of constraint */ 5695 unsigned char op; /* Constraint operator */ 5696 unsigned char usable; /* True if this constraint is usable */ 5697 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5698 } *aConstraint; /* Table of WHERE clause constraints */ 5699 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5700 struct sqlite3_index_orderby { 5701 int iColumn; /* Column number */ 5702 unsigned char desc; /* True for DESC. False for ASC. */ 5703 } *aOrderBy; /* The ORDER BY clause */ 5704 /* Outputs */ 5705 struct sqlite3_index_constraint_usage { 5706 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5707 unsigned char omit; /* Do not code a test for this constraint */ 5708 } *aConstraintUsage; 5709 int idxNum; /* Number used to identify the index */ 5710 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5711 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5712 int orderByConsumed; /* True if output is already ordered */ 5713 double estimatedCost; /* Estimated cost of using this index */ 5714 /* Fields below are only available in SQLite 3.8.2 and later */ 5715 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 5716 /* Fields below are only available in SQLite 3.9.0 and later */ 5717 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 5718 /* Fields below are only available in SQLite 3.10.0 and later */ 5719 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 5720 }; 5721 5722 /* 5723 ** CAPI3REF: Virtual Table Scan Flags 5724 */ 5725 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 5726 5727 /* 5728 ** CAPI3REF: Virtual Table Constraint Operator Codes 5729 ** 5730 ** These macros defined the allowed values for the 5731 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 5732 ** an operator that is part of a constraint term in the wHERE clause of 5733 ** a query that uses a [virtual table]. 5734 */ 5735 #define SQLITE_INDEX_CONSTRAINT_EQ 2 5736 #define SQLITE_INDEX_CONSTRAINT_GT 4 5737 #define SQLITE_INDEX_CONSTRAINT_LE 8 5738 #define SQLITE_INDEX_CONSTRAINT_LT 16 5739 #define SQLITE_INDEX_CONSTRAINT_GE 32 5740 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 5741 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 5742 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 5743 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 5744 5745 /* 5746 ** CAPI3REF: Register A Virtual Table Implementation 5747 ** METHOD: sqlite3 5748 ** 5749 ** ^These routines are used to register a new [virtual table module] name. 5750 ** ^Module names must be registered before 5751 ** creating a new [virtual table] using the module and before using a 5752 ** preexisting [virtual table] for the module. 5753 ** 5754 ** ^The module name is registered on the [database connection] specified 5755 ** by the first parameter. ^The name of the module is given by the 5756 ** second parameter. ^The third parameter is a pointer to 5757 ** the implementation of the [virtual table module]. ^The fourth 5758 ** parameter is an arbitrary client data pointer that is passed through 5759 ** into the [xCreate] and [xConnect] methods of the virtual table module 5760 ** when a new virtual table is be being created or reinitialized. 5761 ** 5762 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 5763 ** is a pointer to a destructor for the pClientData. ^SQLite will 5764 ** invoke the destructor function (if it is not NULL) when SQLite 5765 ** no longer needs the pClientData pointer. ^The destructor will also 5766 ** be invoked if the call to sqlite3_create_module_v2() fails. 5767 ** ^The sqlite3_create_module() 5768 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 5769 ** destructor. 5770 */ 5771 SQLITE_API int SQLITE_STDCALL sqlite3_create_module( 5772 sqlite3 *db, /* SQLite connection to register module with */ 5773 const char *zName, /* Name of the module */ 5774 const sqlite3_module *p, /* Methods for the module */ 5775 void *pClientData /* Client data for xCreate/xConnect */ 5776 ); 5777 SQLITE_API int SQLITE_STDCALL sqlite3_create_module_v2( 5778 sqlite3 *db, /* SQLite connection to register module with */ 5779 const char *zName, /* Name of the module */ 5780 const sqlite3_module *p, /* Methods for the module */ 5781 void *pClientData, /* Client data for xCreate/xConnect */ 5782 void(*xDestroy)(void*) /* Module destructor function */ 5783 ); 5784 5785 /* 5786 ** CAPI3REF: Virtual Table Instance Object 5787 ** KEYWORDS: sqlite3_vtab 5788 ** 5789 ** Every [virtual table module] implementation uses a subclass 5790 ** of this object to describe a particular instance 5791 ** of the [virtual table]. Each subclass will 5792 ** be tailored to the specific needs of the module implementation. 5793 ** The purpose of this superclass is to define certain fields that are 5794 ** common to all module implementations. 5795 ** 5796 ** ^Virtual tables methods can set an error message by assigning a 5797 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 5798 ** take care that any prior string is freed by a call to [sqlite3_free()] 5799 ** prior to assigning a new string to zErrMsg. ^After the error message 5800 ** is delivered up to the client application, the string will be automatically 5801 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 5802 */ 5803 struct sqlite3_vtab { 5804 const sqlite3_module *pModule; /* The module for this virtual table */ 5805 int nRef; /* Number of open cursors */ 5806 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 5807 /* Virtual table implementations will typically add additional fields */ 5808 }; 5809 5810 /* 5811 ** CAPI3REF: Virtual Table Cursor Object 5812 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 5813 ** 5814 ** Every [virtual table module] implementation uses a subclass of the 5815 ** following structure to describe cursors that point into the 5816 ** [virtual table] and are used 5817 ** to loop through the virtual table. Cursors are created using the 5818 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 5819 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 5820 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 5821 ** of the module. Each module implementation will define 5822 ** the content of a cursor structure to suit its own needs. 5823 ** 5824 ** This superclass exists in order to define fields of the cursor that 5825 ** are common to all implementations. 5826 */ 5827 struct sqlite3_vtab_cursor { 5828 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 5829 /* Virtual table implementations will typically add additional fields */ 5830 }; 5831 5832 /* 5833 ** CAPI3REF: Declare The Schema Of A Virtual Table 5834 ** 5835 ** ^The [xCreate] and [xConnect] methods of a 5836 ** [virtual table module] call this interface 5837 ** to declare the format (the names and datatypes of the columns) of 5838 ** the virtual tables they implement. 5839 */ 5840 SQLITE_API int SQLITE_STDCALL sqlite3_declare_vtab(sqlite3*, const char *zSQL); 5841 5842 /* 5843 ** CAPI3REF: Overload A Function For A Virtual Table 5844 ** METHOD: sqlite3 5845 ** 5846 ** ^(Virtual tables can provide alternative implementations of functions 5847 ** using the [xFindFunction] method of the [virtual table module]. 5848 ** But global versions of those functions 5849 ** must exist in order to be overloaded.)^ 5850 ** 5851 ** ^(This API makes sure a global version of a function with a particular 5852 ** name and number of parameters exists. If no such function exists 5853 ** before this API is called, a new function is created.)^ ^The implementation 5854 ** of the new function always causes an exception to be thrown. So 5855 ** the new function is not good for anything by itself. Its only 5856 ** purpose is to be a placeholder function that can be overloaded 5857 ** by a [virtual table]. 5858 */ 5859 SQLITE_API int SQLITE_STDCALL sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 5860 5861 /* 5862 ** The interface to the virtual-table mechanism defined above (back up 5863 ** to a comment remarkably similar to this one) is currently considered 5864 ** to be experimental. The interface might change in incompatible ways. 5865 ** If this is a problem for you, do not use the interface at this time. 5866 ** 5867 ** When the virtual-table mechanism stabilizes, we will declare the 5868 ** interface fixed, support it indefinitely, and remove this comment. 5869 */ 5870 5871 /* 5872 ** CAPI3REF: A Handle To An Open BLOB 5873 ** KEYWORDS: {BLOB handle} {BLOB handles} 5874 ** 5875 ** An instance of this object represents an open BLOB on which 5876 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 5877 ** ^Objects of this type are created by [sqlite3_blob_open()] 5878 ** and destroyed by [sqlite3_blob_close()]. 5879 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 5880 ** can be used to read or write small subsections of the BLOB. 5881 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 5882 */ 5883 typedef struct sqlite3_blob sqlite3_blob; 5884 5885 /* 5886 ** CAPI3REF: Open A BLOB For Incremental I/O 5887 ** METHOD: sqlite3 5888 ** CONSTRUCTOR: sqlite3_blob 5889 ** 5890 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 5891 ** in row iRow, column zColumn, table zTable in database zDb; 5892 ** in other words, the same BLOB that would be selected by: 5893 ** 5894 ** <pre> 5895 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 5896 ** </pre>)^ 5897 ** 5898 ** ^(Parameter zDb is not the filename that contains the database, but 5899 ** rather the symbolic name of the database. For attached databases, this is 5900 ** the name that appears after the AS keyword in the [ATTACH] statement. 5901 ** For the main database file, the database name is "main". For TEMP 5902 ** tables, the database name is "temp".)^ 5903 ** 5904 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 5905 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 5906 ** read-only access. 5907 ** 5908 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 5909 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 5910 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 5911 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 5912 ** on *ppBlob after this function it returns. 5913 ** 5914 ** This function fails with SQLITE_ERROR if any of the following are true: 5915 ** <ul> 5916 ** <li> ^(Database zDb does not exist)^, 5917 ** <li> ^(Table zTable does not exist within database zDb)^, 5918 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 5919 ** <li> ^(Column zColumn does not exist)^, 5920 ** <li> ^(Row iRow is not present in the table)^, 5921 ** <li> ^(The specified column of row iRow contains a value that is not 5922 ** a TEXT or BLOB value)^, 5923 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 5924 ** constraint and the blob is being opened for read/write access)^, 5925 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 5926 ** column zColumn is part of a [child key] definition and the blob is 5927 ** being opened for read/write access)^. 5928 ** </ul> 5929 ** 5930 ** ^Unless it returns SQLITE_MISUSE, this function sets the 5931 ** [database connection] error code and message accessible via 5932 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 5933 ** 5934 ** 5935 ** ^(If the row that a BLOB handle points to is modified by an 5936 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 5937 ** then the BLOB handle is marked as "expired". 5938 ** This is true if any column of the row is changed, even a column 5939 ** other than the one the BLOB handle is open on.)^ 5940 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 5941 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 5942 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 5943 ** rolled back by the expiration of the BLOB. Such changes will eventually 5944 ** commit if the transaction continues to completion.)^ 5945 ** 5946 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 5947 ** the opened blob. ^The size of a blob may not be changed by this 5948 ** interface. Use the [UPDATE] SQL command to change the size of a 5949 ** blob. 5950 ** 5951 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 5952 ** and the built-in [zeroblob] SQL function may be used to create a 5953 ** zero-filled blob to read or write using the incremental-blob interface. 5954 ** 5955 ** To avoid a resource leak, every open [BLOB handle] should eventually 5956 ** be released by a call to [sqlite3_blob_close()]. 5957 */ 5958 SQLITE_API int SQLITE_STDCALL sqlite3_blob_open( 5959 sqlite3*, 5960 const char *zDb, 5961 const char *zTable, 5962 const char *zColumn, 5963 sqlite3_int64 iRow, 5964 int flags, 5965 sqlite3_blob **ppBlob 5966 ); 5967 5968 /* 5969 ** CAPI3REF: Move a BLOB Handle to a New Row 5970 ** METHOD: sqlite3_blob 5971 ** 5972 ** ^This function is used to move an existing blob handle so that it points 5973 ** to a different row of the same database table. ^The new row is identified 5974 ** by the rowid value passed as the second argument. Only the row can be 5975 ** changed. ^The database, table and column on which the blob handle is open 5976 ** remain the same. Moving an existing blob handle to a new row can be 5977 ** faster than closing the existing handle and opening a new one. 5978 ** 5979 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 5980 ** it must exist and there must be either a blob or text value stored in 5981 ** the nominated column.)^ ^If the new row is not present in the table, or if 5982 ** it does not contain a blob or text value, or if another error occurs, an 5983 ** SQLite error code is returned and the blob handle is considered aborted. 5984 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 5985 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 5986 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 5987 ** always returns zero. 5988 ** 5989 ** ^This function sets the database handle error code and message. 5990 */ 5991 SQLITE_API int SQLITE_STDCALL sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 5992 5993 /* 5994 ** CAPI3REF: Close A BLOB Handle 5995 ** DESTRUCTOR: sqlite3_blob 5996 ** 5997 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 5998 ** unconditionally. Even if this routine returns an error code, the 5999 ** handle is still closed.)^ 6000 ** 6001 ** ^If the blob handle being closed was opened for read-write access, and if 6002 ** the database is in auto-commit mode and there are no other open read-write 6003 ** blob handles or active write statements, the current transaction is 6004 ** committed. ^If an error occurs while committing the transaction, an error 6005 ** code is returned and the transaction rolled back. 6006 ** 6007 ** Calling this function with an argument that is not a NULL pointer or an 6008 ** open blob handle results in undefined behaviour. ^Calling this routine 6009 ** with a null pointer (such as would be returned by a failed call to 6010 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6011 ** is passed a valid open blob handle, the values returned by the 6012 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6013 */ 6014 SQLITE_API int SQLITE_STDCALL sqlite3_blob_close(sqlite3_blob *); 6015 6016 /* 6017 ** CAPI3REF: Return The Size Of An Open BLOB 6018 ** METHOD: sqlite3_blob 6019 ** 6020 ** ^Returns the size in bytes of the BLOB accessible via the 6021 ** successfully opened [BLOB handle] in its only argument. ^The 6022 ** incremental blob I/O routines can only read or overwriting existing 6023 ** blob content; they cannot change the size of a blob. 6024 ** 6025 ** This routine only works on a [BLOB handle] which has been created 6026 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6027 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6028 ** to this routine results in undefined and probably undesirable behavior. 6029 */ 6030 SQLITE_API int SQLITE_STDCALL sqlite3_blob_bytes(sqlite3_blob *); 6031 6032 /* 6033 ** CAPI3REF: Read Data From A BLOB Incrementally 6034 ** METHOD: sqlite3_blob 6035 ** 6036 ** ^(This function is used to read data from an open [BLOB handle] into a 6037 ** caller-supplied buffer. N bytes of data are copied into buffer Z 6038 ** from the open BLOB, starting at offset iOffset.)^ 6039 ** 6040 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6041 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6042 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 6043 ** ^The size of the blob (and hence the maximum value of N+iOffset) 6044 ** can be determined using the [sqlite3_blob_bytes()] interface. 6045 ** 6046 ** ^An attempt to read from an expired [BLOB handle] fails with an 6047 ** error code of [SQLITE_ABORT]. 6048 ** 6049 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6050 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6051 ** 6052 ** This routine only works on a [BLOB handle] which has been created 6053 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6054 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6055 ** to this routine results in undefined and probably undesirable behavior. 6056 ** 6057 ** See also: [sqlite3_blob_write()]. 6058 */ 6059 SQLITE_API int SQLITE_STDCALL sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6060 6061 /* 6062 ** CAPI3REF: Write Data Into A BLOB Incrementally 6063 ** METHOD: sqlite3_blob 6064 ** 6065 ** ^(This function is used to write data into an open [BLOB handle] from a 6066 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 6067 ** into the open BLOB, starting at offset iOffset.)^ 6068 ** 6069 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6070 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6071 ** ^Unless SQLITE_MISUSE is returned, this function sets the 6072 ** [database connection] error code and message accessible via 6073 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6074 ** 6075 ** ^If the [BLOB handle] passed as the first argument was not opened for 6076 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6077 ** this function returns [SQLITE_READONLY]. 6078 ** 6079 ** This function may only modify the contents of the BLOB; it is 6080 ** not possible to increase the size of a BLOB using this API. 6081 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6082 ** [SQLITE_ERROR] is returned and no data is written. The size of the 6083 ** BLOB (and hence the maximum value of N+iOffset) can be determined 6084 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6085 ** than zero [SQLITE_ERROR] is returned and no data is written. 6086 ** 6087 ** ^An attempt to write to an expired [BLOB handle] fails with an 6088 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6089 ** before the [BLOB handle] expired are not rolled back by the 6090 ** expiration of the handle, though of course those changes might 6091 ** have been overwritten by the statement that expired the BLOB handle 6092 ** or by other independent statements. 6093 ** 6094 ** This routine only works on a [BLOB handle] which has been created 6095 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6096 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6097 ** to this routine results in undefined and probably undesirable behavior. 6098 ** 6099 ** See also: [sqlite3_blob_read()]. 6100 */ 6101 SQLITE_API int SQLITE_STDCALL sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6102 6103 /* 6104 ** CAPI3REF: Virtual File System Objects 6105 ** 6106 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6107 ** that SQLite uses to interact 6108 ** with the underlying operating system. Most SQLite builds come with a 6109 ** single default VFS that is appropriate for the host computer. 6110 ** New VFSes can be registered and existing VFSes can be unregistered. 6111 ** The following interfaces are provided. 6112 ** 6113 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6114 ** ^Names are case sensitive. 6115 ** ^Names are zero-terminated UTF-8 strings. 6116 ** ^If there is no match, a NULL pointer is returned. 6117 ** ^If zVfsName is NULL then the default VFS is returned. 6118 ** 6119 ** ^New VFSes are registered with sqlite3_vfs_register(). 6120 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6121 ** ^The same VFS can be registered multiple times without injury. 6122 ** ^To make an existing VFS into the default VFS, register it again 6123 ** with the makeDflt flag set. If two different VFSes with the 6124 ** same name are registered, the behavior is undefined. If a 6125 ** VFS is registered with a name that is NULL or an empty string, 6126 ** then the behavior is undefined. 6127 ** 6128 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6129 ** ^(If the default VFS is unregistered, another VFS is chosen as 6130 ** the default. The choice for the new VFS is arbitrary.)^ 6131 */ 6132 SQLITE_API sqlite3_vfs *SQLITE_STDCALL sqlite3_vfs_find(const char *zVfsName); 6133 SQLITE_API int SQLITE_STDCALL sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6134 SQLITE_API int SQLITE_STDCALL sqlite3_vfs_unregister(sqlite3_vfs*); 6135 6136 /* 6137 ** CAPI3REF: Mutexes 6138 ** 6139 ** The SQLite core uses these routines for thread 6140 ** synchronization. Though they are intended for internal 6141 ** use by SQLite, code that links against SQLite is 6142 ** permitted to use any of these routines. 6143 ** 6144 ** The SQLite source code contains multiple implementations 6145 ** of these mutex routines. An appropriate implementation 6146 ** is selected automatically at compile-time. The following 6147 ** implementations are available in the SQLite core: 6148 ** 6149 ** <ul> 6150 ** <li> SQLITE_MUTEX_PTHREADS 6151 ** <li> SQLITE_MUTEX_W32 6152 ** <li> SQLITE_MUTEX_NOOP 6153 ** </ul> 6154 ** 6155 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 6156 ** that does no real locking and is appropriate for use in 6157 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6158 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6159 ** and Windows. 6160 ** 6161 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6162 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6163 ** implementation is included with the library. In this case the 6164 ** application must supply a custom mutex implementation using the 6165 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6166 ** before calling sqlite3_initialize() or any other public sqlite3_ 6167 ** function that calls sqlite3_initialize(). 6168 ** 6169 ** ^The sqlite3_mutex_alloc() routine allocates a new 6170 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6171 ** routine returns NULL if it is unable to allocate the requested 6172 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 6173 ** integer constants: 6174 ** 6175 ** <ul> 6176 ** <li> SQLITE_MUTEX_FAST 6177 ** <li> SQLITE_MUTEX_RECURSIVE 6178 ** <li> SQLITE_MUTEX_STATIC_MASTER 6179 ** <li> SQLITE_MUTEX_STATIC_MEM 6180 ** <li> SQLITE_MUTEX_STATIC_OPEN 6181 ** <li> SQLITE_MUTEX_STATIC_PRNG 6182 ** <li> SQLITE_MUTEX_STATIC_LRU 6183 ** <li> SQLITE_MUTEX_STATIC_PMEM 6184 ** <li> SQLITE_MUTEX_STATIC_APP1 6185 ** <li> SQLITE_MUTEX_STATIC_APP2 6186 ** <li> SQLITE_MUTEX_STATIC_APP3 6187 ** <li> SQLITE_MUTEX_STATIC_VFS1 6188 ** <li> SQLITE_MUTEX_STATIC_VFS2 6189 ** <li> SQLITE_MUTEX_STATIC_VFS3 6190 ** </ul> 6191 ** 6192 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6193 ** cause sqlite3_mutex_alloc() to create 6194 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6195 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6196 ** The mutex implementation does not need to make a distinction 6197 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6198 ** not want to. SQLite will only request a recursive mutex in 6199 ** cases where it really needs one. If a faster non-recursive mutex 6200 ** implementation is available on the host platform, the mutex subsystem 6201 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 6202 ** 6203 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6204 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6205 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 6206 ** used by the current version of SQLite. Future versions of SQLite 6207 ** may add additional static mutexes. Static mutexes are for internal 6208 ** use by SQLite only. Applications that use SQLite mutexes should 6209 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6210 ** SQLITE_MUTEX_RECURSIVE. 6211 ** 6212 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6213 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6214 ** returns a different mutex on every call. ^For the static 6215 ** mutex types, the same mutex is returned on every call that has 6216 ** the same type number. 6217 ** 6218 ** ^The sqlite3_mutex_free() routine deallocates a previously 6219 ** allocated dynamic mutex. Attempting to deallocate a static 6220 ** mutex results in undefined behavior. 6221 ** 6222 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6223 ** to enter a mutex. ^If another thread is already within the mutex, 6224 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6225 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6226 ** upon successful entry. ^(Mutexes created using 6227 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6228 ** In such cases, the 6229 ** mutex must be exited an equal number of times before another thread 6230 ** can enter.)^ If the same thread tries to enter any mutex other 6231 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6232 ** 6233 ** ^(Some systems (for example, Windows 95) do not support the operation 6234 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6235 ** will always return SQLITE_BUSY. The SQLite core only ever uses 6236 ** sqlite3_mutex_try() as an optimization so this is acceptable 6237 ** behavior.)^ 6238 ** 6239 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 6240 ** previously entered by the same thread. The behavior 6241 ** is undefined if the mutex is not currently entered by the 6242 ** calling thread or is not currently allocated. 6243 ** 6244 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6245 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6246 ** behave as no-ops. 6247 ** 6248 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6249 */ 6250 SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_mutex_alloc(int); 6251 SQLITE_API void SQLITE_STDCALL sqlite3_mutex_free(sqlite3_mutex*); 6252 SQLITE_API void SQLITE_STDCALL sqlite3_mutex_enter(sqlite3_mutex*); 6253 SQLITE_API int SQLITE_STDCALL sqlite3_mutex_try(sqlite3_mutex*); 6254 SQLITE_API void SQLITE_STDCALL sqlite3_mutex_leave(sqlite3_mutex*); 6255 6256 /* 6257 ** CAPI3REF: Mutex Methods Object 6258 ** 6259 ** An instance of this structure defines the low-level routines 6260 ** used to allocate and use mutexes. 6261 ** 6262 ** Usually, the default mutex implementations provided by SQLite are 6263 ** sufficient, however the application has the option of substituting a custom 6264 ** implementation for specialized deployments or systems for which SQLite 6265 ** does not provide a suitable implementation. In this case, the application 6266 ** creates and populates an instance of this structure to pass 6267 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6268 ** Additionally, an instance of this structure can be used as an 6269 ** output variable when querying the system for the current mutex 6270 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6271 ** 6272 ** ^The xMutexInit method defined by this structure is invoked as 6273 ** part of system initialization by the sqlite3_initialize() function. 6274 ** ^The xMutexInit routine is called by SQLite exactly once for each 6275 ** effective call to [sqlite3_initialize()]. 6276 ** 6277 ** ^The xMutexEnd method defined by this structure is invoked as 6278 ** part of system shutdown by the sqlite3_shutdown() function. The 6279 ** implementation of this method is expected to release all outstanding 6280 ** resources obtained by the mutex methods implementation, especially 6281 ** those obtained by the xMutexInit method. ^The xMutexEnd() 6282 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6283 ** 6284 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6285 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6286 ** xMutexNotheld) implement the following interfaces (respectively): 6287 ** 6288 ** <ul> 6289 ** <li> [sqlite3_mutex_alloc()] </li> 6290 ** <li> [sqlite3_mutex_free()] </li> 6291 ** <li> [sqlite3_mutex_enter()] </li> 6292 ** <li> [sqlite3_mutex_try()] </li> 6293 ** <li> [sqlite3_mutex_leave()] </li> 6294 ** <li> [sqlite3_mutex_held()] </li> 6295 ** <li> [sqlite3_mutex_notheld()] </li> 6296 ** </ul>)^ 6297 ** 6298 ** The only difference is that the public sqlite3_XXX functions enumerated 6299 ** above silently ignore any invocations that pass a NULL pointer instead 6300 ** of a valid mutex handle. The implementations of the methods defined 6301 ** by this structure are not required to handle this case, the results 6302 ** of passing a NULL pointer instead of a valid mutex handle are undefined 6303 ** (i.e. it is acceptable to provide an implementation that segfaults if 6304 ** it is passed a NULL pointer). 6305 ** 6306 ** The xMutexInit() method must be threadsafe. It must be harmless to 6307 ** invoke xMutexInit() multiple times within the same process and without 6308 ** intervening calls to xMutexEnd(). Second and subsequent calls to 6309 ** xMutexInit() must be no-ops. 6310 ** 6311 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6312 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 6313 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6314 ** memory allocation for a fast or recursive mutex. 6315 ** 6316 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6317 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6318 ** If xMutexInit fails in any way, it is expected to clean up after itself 6319 ** prior to returning. 6320 */ 6321 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6322 struct sqlite3_mutex_methods { 6323 int (*xMutexInit)(void); 6324 int (*xMutexEnd)(void); 6325 sqlite3_mutex *(*xMutexAlloc)(int); 6326 void (*xMutexFree)(sqlite3_mutex *); 6327 void (*xMutexEnter)(sqlite3_mutex *); 6328 int (*xMutexTry)(sqlite3_mutex *); 6329 void (*xMutexLeave)(sqlite3_mutex *); 6330 int (*xMutexHeld)(sqlite3_mutex *); 6331 int (*xMutexNotheld)(sqlite3_mutex *); 6332 }; 6333 6334 /* 6335 ** CAPI3REF: Mutex Verification Routines 6336 ** 6337 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6338 ** are intended for use inside assert() statements. The SQLite core 6339 ** never uses these routines except inside an assert() and applications 6340 ** are advised to follow the lead of the core. The SQLite core only 6341 ** provides implementations for these routines when it is compiled 6342 ** with the SQLITE_DEBUG flag. External mutex implementations 6343 ** are only required to provide these routines if SQLITE_DEBUG is 6344 ** defined and if NDEBUG is not defined. 6345 ** 6346 ** These routines should return true if the mutex in their argument 6347 ** is held or not held, respectively, by the calling thread. 6348 ** 6349 ** The implementation is not required to provide versions of these 6350 ** routines that actually work. If the implementation does not provide working 6351 ** versions of these routines, it should at least provide stubs that always 6352 ** return true so that one does not get spurious assertion failures. 6353 ** 6354 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 6355 ** the routine should return 1. This seems counter-intuitive since 6356 ** clearly the mutex cannot be held if it does not exist. But 6357 ** the reason the mutex does not exist is because the build is not 6358 ** using mutexes. And we do not want the assert() containing the 6359 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 6360 ** the appropriate thing to do. The sqlite3_mutex_notheld() 6361 ** interface should also return 1 when given a NULL pointer. 6362 */ 6363 #ifndef NDEBUG 6364 SQLITE_API int SQLITE_STDCALL sqlite3_mutex_held(sqlite3_mutex*); 6365 SQLITE_API int SQLITE_STDCALL sqlite3_mutex_notheld(sqlite3_mutex*); 6366 #endif 6367 6368 /* 6369 ** CAPI3REF: Mutex Types 6370 ** 6371 ** The [sqlite3_mutex_alloc()] interface takes a single argument 6372 ** which is one of these integer constants. 6373 ** 6374 ** The set of static mutexes may change from one SQLite release to the 6375 ** next. Applications that override the built-in mutex logic must be 6376 ** prepared to accommodate additional static mutexes. 6377 */ 6378 #define SQLITE_MUTEX_FAST 0 6379 #define SQLITE_MUTEX_RECURSIVE 1 6380 #define SQLITE_MUTEX_STATIC_MASTER 2 6381 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6382 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6383 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6384 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 6385 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6386 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6387 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6388 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6389 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6390 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6391 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 6392 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 6393 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 6394 6395 /* 6396 ** CAPI3REF: Retrieve the mutex for a database connection 6397 ** METHOD: sqlite3 6398 ** 6399 ** ^This interface returns a pointer the [sqlite3_mutex] object that 6400 ** serializes access to the [database connection] given in the argument 6401 ** when the [threading mode] is Serialized. 6402 ** ^If the [threading mode] is Single-thread or Multi-thread then this 6403 ** routine returns a NULL pointer. 6404 */ 6405 SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_db_mutex(sqlite3*); 6406 6407 /* 6408 ** CAPI3REF: Low-Level Control Of Database Files 6409 ** METHOD: sqlite3 6410 ** 6411 ** ^The [sqlite3_file_control()] interface makes a direct call to the 6412 ** xFileControl method for the [sqlite3_io_methods] object associated 6413 ** with a particular database identified by the second argument. ^The 6414 ** name of the database is "main" for the main database or "temp" for the 6415 ** TEMP database, or the name that appears after the AS keyword for 6416 ** databases that are added using the [ATTACH] SQL command. 6417 ** ^A NULL pointer can be used in place of "main" to refer to the 6418 ** main database file. 6419 ** ^The third and fourth parameters to this routine 6420 ** are passed directly through to the second and third parameters of 6421 ** the xFileControl method. ^The return value of the xFileControl 6422 ** method becomes the return value of this routine. 6423 ** 6424 ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6425 ** a pointer to the underlying [sqlite3_file] object to be written into 6426 ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6427 ** case is a short-circuit path which does not actually invoke the 6428 ** underlying sqlite3_io_methods.xFileControl method. 6429 ** 6430 ** ^If the second parameter (zDbName) does not match the name of any 6431 ** open database file, then SQLITE_ERROR is returned. ^This error 6432 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 6433 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 6434 ** also return SQLITE_ERROR. There is no way to distinguish between 6435 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6436 ** xFileControl method. 6437 ** 6438 ** See also: [SQLITE_FCNTL_LOCKSTATE] 6439 */ 6440 SQLITE_API int SQLITE_STDCALL sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6441 6442 /* 6443 ** CAPI3REF: Testing Interface 6444 ** 6445 ** ^The sqlite3_test_control() interface is used to read out internal 6446 ** state of SQLite and to inject faults into SQLite for testing 6447 ** purposes. ^The first parameter is an operation code that determines 6448 ** the number, meaning, and operation of all subsequent parameters. 6449 ** 6450 ** This interface is not for use by applications. It exists solely 6451 ** for verifying the correct operation of the SQLite library. Depending 6452 ** on how the SQLite library is compiled, this interface might not exist. 6453 ** 6454 ** The details of the operation codes, their meanings, the parameters 6455 ** they take, and what they do are all subject to change without notice. 6456 ** Unlike most of the SQLite API, this function is not guaranteed to 6457 ** operate consistently from one release to the next. 6458 */ 6459 SQLITE_API int SQLITE_CDECL sqlite3_test_control(int op, ...); 6460 6461 /* 6462 ** CAPI3REF: Testing Interface Operation Codes 6463 ** 6464 ** These constants are the valid operation code parameters used 6465 ** as the first argument to [sqlite3_test_control()]. 6466 ** 6467 ** These parameters and their meanings are subject to change 6468 ** without notice. These values are for testing purposes only. 6469 ** Applications should not use any of these parameters or the 6470 ** [sqlite3_test_control()] interface. 6471 */ 6472 #define SQLITE_TESTCTRL_FIRST 5 6473 #define SQLITE_TESTCTRL_PRNG_SAVE 5 6474 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 6475 #define SQLITE_TESTCTRL_PRNG_RESET 7 6476 #define SQLITE_TESTCTRL_BITVEC_TEST 8 6477 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 6478 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6479 #define SQLITE_TESTCTRL_PENDING_BYTE 11 6480 #define SQLITE_TESTCTRL_ASSERT 12 6481 #define SQLITE_TESTCTRL_ALWAYS 13 6482 #define SQLITE_TESTCTRL_RESERVE 14 6483 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 6484 #define SQLITE_TESTCTRL_ISKEYWORD 16 6485 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6486 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6487 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 6488 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 6489 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 6490 #define SQLITE_TESTCTRL_BYTEORDER 22 6491 #define SQLITE_TESTCTRL_ISINIT 23 6492 #define SQLITE_TESTCTRL_SORTER_MMAP 24 6493 #define SQLITE_TESTCTRL_IMPOSTER 25 6494 #define SQLITE_TESTCTRL_LAST 25 6495 6496 /* 6497 ** CAPI3REF: SQLite Runtime Status 6498 ** 6499 ** ^These interfaces are used to retrieve runtime status information 6500 ** about the performance of SQLite, and optionally to reset various 6501 ** highwater marks. ^The first argument is an integer code for 6502 ** the specific parameter to measure. ^(Recognized integer codes 6503 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 6504 ** ^The current value of the parameter is returned into *pCurrent. 6505 ** ^The highest recorded value is returned in *pHighwater. ^If the 6506 ** resetFlag is true, then the highest record value is reset after 6507 ** *pHighwater is written. ^(Some parameters do not record the highest 6508 ** value. For those parameters 6509 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6510 ** ^(Other parameters record only the highwater mark and not the current 6511 ** value. For these latter parameters nothing is written into *pCurrent.)^ 6512 ** 6513 ** ^The sqlite3_status() and sqlite3_status64() routines return 6514 ** SQLITE_OK on success and a non-zero [error code] on failure. 6515 ** 6516 ** If either the current value or the highwater mark is too large to 6517 ** be represented by a 32-bit integer, then the values returned by 6518 ** sqlite3_status() are undefined. 6519 ** 6520 ** See also: [sqlite3_db_status()] 6521 */ 6522 SQLITE_API int SQLITE_STDCALL sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6523 SQLITE_API int SQLITE_STDCALL sqlite3_status64( 6524 int op, 6525 sqlite3_int64 *pCurrent, 6526 sqlite3_int64 *pHighwater, 6527 int resetFlag 6528 ); 6529 6530 6531 /* 6532 ** CAPI3REF: Status Parameters 6533 ** KEYWORDS: {status parameters} 6534 ** 6535 ** These integer constants designate various run-time status parameters 6536 ** that can be returned by [sqlite3_status()]. 6537 ** 6538 ** <dl> 6539 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6540 ** <dd>This parameter is the current amount of memory checked out 6541 ** using [sqlite3_malloc()], either directly or indirectly. The 6542 ** figure includes calls made to [sqlite3_malloc()] by the application 6543 ** and internal memory usage by the SQLite library. Scratch memory 6544 ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6545 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6546 ** this parameter. The amount returned is the sum of the allocation 6547 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6548 ** 6549 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6550 ** <dd>This parameter records the largest memory allocation request 6551 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6552 ** internal equivalents). Only the value returned in the 6553 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6554 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6555 ** 6556 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6557 ** <dd>This parameter records the number of separate memory allocations 6558 ** currently checked out.</dd>)^ 6559 ** 6560 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6561 ** <dd>This parameter returns the number of pages used out of the 6562 ** [pagecache memory allocator] that was configured using 6563 ** [SQLITE_CONFIG_PAGECACHE]. The 6564 ** value returned is in pages, not in bytes.</dd>)^ 6565 ** 6566 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6567 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6568 ** <dd>This parameter returns the number of bytes of page cache 6569 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6570 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 6571 ** returned value includes allocations that overflowed because they 6572 ** where too large (they were larger than the "sz" parameter to 6573 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6574 ** no space was left in the page cache.</dd>)^ 6575 ** 6576 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6577 ** <dd>This parameter records the largest memory allocation request 6578 ** handed to [pagecache memory allocator]. Only the value returned in the 6579 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6580 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6581 ** 6582 ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6583 ** <dd>This parameter returns the number of allocations used out of the 6584 ** [scratch memory allocator] configured using 6585 ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6586 ** in bytes. Since a single thread may only have one scratch allocation 6587 ** outstanding at time, this parameter also reports the number of threads 6588 ** using scratch memory at the same time.</dd>)^ 6589 ** 6590 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6591 ** <dd>This parameter returns the number of bytes of scratch memory 6592 ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6593 ** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6594 ** returned include overflows because the requested allocation was too 6595 ** larger (that is, because the requested allocation was larger than the 6596 ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6597 ** slots were available. 6598 ** </dd>)^ 6599 ** 6600 ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6601 ** <dd>This parameter records the largest memory allocation request 6602 ** handed to [scratch memory allocator]. Only the value returned in the 6603 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6604 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6605 ** 6606 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6607 ** <dd>The *pHighwater parameter records the deepest parser stack. 6608 ** The *pCurrent value is undefined. The *pHighwater value is only 6609 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6610 ** </dl> 6611 ** 6612 ** New status parameters may be added from time to time. 6613 */ 6614 #define SQLITE_STATUS_MEMORY_USED 0 6615 #define SQLITE_STATUS_PAGECACHE_USED 1 6616 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6617 #define SQLITE_STATUS_SCRATCH_USED 3 6618 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6619 #define SQLITE_STATUS_MALLOC_SIZE 5 6620 #define SQLITE_STATUS_PARSER_STACK 6 6621 #define SQLITE_STATUS_PAGECACHE_SIZE 7 6622 #define SQLITE_STATUS_SCRATCH_SIZE 8 6623 #define SQLITE_STATUS_MALLOC_COUNT 9 6624 6625 /* 6626 ** CAPI3REF: Database Connection Status 6627 ** METHOD: sqlite3 6628 ** 6629 ** ^This interface is used to retrieve runtime status information 6630 ** about a single [database connection]. ^The first argument is the 6631 ** database connection object to be interrogated. ^The second argument 6632 ** is an integer constant, taken from the set of 6633 ** [SQLITE_DBSTATUS options], that 6634 ** determines the parameter to interrogate. The set of 6635 ** [SQLITE_DBSTATUS options] is likely 6636 ** to grow in future releases of SQLite. 6637 ** 6638 ** ^The current value of the requested parameter is written into *pCur 6639 ** and the highest instantaneous value is written into *pHiwtr. ^If 6640 ** the resetFlg is true, then the highest instantaneous value is 6641 ** reset back down to the current value. 6642 ** 6643 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6644 ** non-zero [error code] on failure. 6645 ** 6646 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6647 */ 6648 SQLITE_API int SQLITE_STDCALL sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6649 6650 /* 6651 ** CAPI3REF: Status Parameters for database connections 6652 ** KEYWORDS: {SQLITE_DBSTATUS options} 6653 ** 6654 ** These constants are the available integer "verbs" that can be passed as 6655 ** the second argument to the [sqlite3_db_status()] interface. 6656 ** 6657 ** New verbs may be added in future releases of SQLite. Existing verbs 6658 ** might be discontinued. Applications should check the return code from 6659 ** [sqlite3_db_status()] to make sure that the call worked. 6660 ** The [sqlite3_db_status()] interface will return a non-zero error code 6661 ** if a discontinued or unsupported verb is invoked. 6662 ** 6663 ** <dl> 6664 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6665 ** <dd>This parameter returns the number of lookaside memory slots currently 6666 ** checked out.</dd>)^ 6667 ** 6668 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6669 ** <dd>This parameter returns the number malloc attempts that were 6670 ** satisfied using lookaside memory. Only the high-water value is meaningful; 6671 ** the current value is always zero.)^ 6672 ** 6673 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6674 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6675 ** <dd>This parameter returns the number malloc attempts that might have 6676 ** been satisfied using lookaside memory but failed due to the amount of 6677 ** memory requested being larger than the lookaside slot size. 6678 ** Only the high-water value is meaningful; 6679 ** the current value is always zero.)^ 6680 ** 6681 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6682 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6683 ** <dd>This parameter returns the number malloc attempts that might have 6684 ** been satisfied using lookaside memory but failed due to all lookaside 6685 ** memory already being in use. 6686 ** Only the high-water value is meaningful; 6687 ** the current value is always zero.)^ 6688 ** 6689 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6690 ** <dd>This parameter returns the approximate number of bytes of heap 6691 ** memory used by all pager caches associated with the database connection.)^ 6692 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6693 ** 6694 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6695 ** <dd>This parameter returns the approximate number of bytes of heap 6696 ** memory used to store the schema for all databases associated 6697 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6698 ** ^The full amount of memory used by the schemas is reported, even if the 6699 ** schema memory is shared with other database connections due to 6700 ** [shared cache mode] being enabled. 6701 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6702 ** 6703 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6704 ** <dd>This parameter returns the approximate number of bytes of heap 6705 ** and lookaside memory used by all prepared statements associated with 6706 ** the database connection.)^ 6707 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6708 ** </dd> 6709 ** 6710 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6711 ** <dd>This parameter returns the number of pager cache hits that have 6712 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6713 ** is always 0. 6714 ** </dd> 6715 ** 6716 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6717 ** <dd>This parameter returns the number of pager cache misses that have 6718 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 6719 ** is always 0. 6720 ** </dd> 6721 ** 6722 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 6723 ** <dd>This parameter returns the number of dirty cache entries that have 6724 ** been written to disk. Specifically, the number of pages written to the 6725 ** wal file in wal mode databases, or the number of pages written to the 6726 ** database file in rollback mode databases. Any pages written as part of 6727 ** transaction rollback or database recovery operations are not included. 6728 ** If an IO or other error occurs while writing a page to disk, the effect 6729 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 6730 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 6731 ** </dd> 6732 ** 6733 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 6734 ** <dd>This parameter returns zero for the current value if and only if 6735 ** all foreign key constraints (deferred or immediate) have been 6736 ** resolved.)^ ^The highwater mark is always 0. 6737 ** </dd> 6738 ** </dl> 6739 */ 6740 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 6741 #define SQLITE_DBSTATUS_CACHE_USED 1 6742 #define SQLITE_DBSTATUS_SCHEMA_USED 2 6743 #define SQLITE_DBSTATUS_STMT_USED 3 6744 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 6745 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 6746 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 6747 #define SQLITE_DBSTATUS_CACHE_HIT 7 6748 #define SQLITE_DBSTATUS_CACHE_MISS 8 6749 #define SQLITE_DBSTATUS_CACHE_WRITE 9 6750 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 6751 #define SQLITE_DBSTATUS_MAX 10 /* Largest defined DBSTATUS */ 6752 6753 6754 /* 6755 ** CAPI3REF: Prepared Statement Status 6756 ** METHOD: sqlite3_stmt 6757 ** 6758 ** ^(Each prepared statement maintains various 6759 ** [SQLITE_STMTSTATUS counters] that measure the number 6760 ** of times it has performed specific operations.)^ These counters can 6761 ** be used to monitor the performance characteristics of the prepared 6762 ** statements. For example, if the number of table steps greatly exceeds 6763 ** the number of table searches or result rows, that would tend to indicate 6764 ** that the prepared statement is using a full table scan rather than 6765 ** an index. 6766 ** 6767 ** ^(This interface is used to retrieve and reset counter values from 6768 ** a [prepared statement]. The first argument is the prepared statement 6769 ** object to be interrogated. The second argument 6770 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 6771 ** to be interrogated.)^ 6772 ** ^The current value of the requested counter is returned. 6773 ** ^If the resetFlg is true, then the counter is reset to zero after this 6774 ** interface call returns. 6775 ** 6776 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 6777 */ 6778 SQLITE_API int SQLITE_STDCALL sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 6779 6780 /* 6781 ** CAPI3REF: Status Parameters for prepared statements 6782 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 6783 ** 6784 ** These preprocessor macros define integer codes that name counter 6785 ** values associated with the [sqlite3_stmt_status()] interface. 6786 ** The meanings of the various counters are as follows: 6787 ** 6788 ** <dl> 6789 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 6790 ** <dd>^This is the number of times that SQLite has stepped forward in 6791 ** a table as part of a full table scan. Large numbers for this counter 6792 ** may indicate opportunities for performance improvement through 6793 ** careful use of indices.</dd> 6794 ** 6795 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 6796 ** <dd>^This is the number of sort operations that have occurred. 6797 ** A non-zero value in this counter may indicate an opportunity to 6798 ** improvement performance through careful use of indices.</dd> 6799 ** 6800 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 6801 ** <dd>^This is the number of rows inserted into transient indices that 6802 ** were created automatically in order to help joins run faster. 6803 ** A non-zero value in this counter may indicate an opportunity to 6804 ** improvement performance by adding permanent indices that do not 6805 ** need to be reinitialized each time the statement is run.</dd> 6806 ** 6807 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 6808 ** <dd>^This is the number of virtual machine operations executed 6809 ** by the prepared statement if that number is less than or equal 6810 ** to 2147483647. The number of virtual machine operations can be 6811 ** used as a proxy for the total work done by the prepared statement. 6812 ** If the number of virtual machine operations exceeds 2147483647 6813 ** then the value returned by this statement status code is undefined. 6814 ** </dd> 6815 ** </dl> 6816 */ 6817 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 6818 #define SQLITE_STMTSTATUS_SORT 2 6819 #define SQLITE_STMTSTATUS_AUTOINDEX 3 6820 #define SQLITE_STMTSTATUS_VM_STEP 4 6821 6822 /* 6823 ** CAPI3REF: Custom Page Cache Object 6824 ** 6825 ** The sqlite3_pcache type is opaque. It is implemented by 6826 ** the pluggable module. The SQLite core has no knowledge of 6827 ** its size or internal structure and never deals with the 6828 ** sqlite3_pcache object except by holding and passing pointers 6829 ** to the object. 6830 ** 6831 ** See [sqlite3_pcache_methods2] for additional information. 6832 */ 6833 typedef struct sqlite3_pcache sqlite3_pcache; 6834 6835 /* 6836 ** CAPI3REF: Custom Page Cache Object 6837 ** 6838 ** The sqlite3_pcache_page object represents a single page in the 6839 ** page cache. The page cache will allocate instances of this 6840 ** object. Various methods of the page cache use pointers to instances 6841 ** of this object as parameters or as their return value. 6842 ** 6843 ** See [sqlite3_pcache_methods2] for additional information. 6844 */ 6845 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 6846 struct sqlite3_pcache_page { 6847 void *pBuf; /* The content of the page */ 6848 void *pExtra; /* Extra information associated with the page */ 6849 }; 6850 6851 /* 6852 ** CAPI3REF: Application Defined Page Cache. 6853 ** KEYWORDS: {page cache} 6854 ** 6855 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 6856 ** register an alternative page cache implementation by passing in an 6857 ** instance of the sqlite3_pcache_methods2 structure.)^ 6858 ** In many applications, most of the heap memory allocated by 6859 ** SQLite is used for the page cache. 6860 ** By implementing a 6861 ** custom page cache using this API, an application can better control 6862 ** the amount of memory consumed by SQLite, the way in which 6863 ** that memory is allocated and released, and the policies used to 6864 ** determine exactly which parts of a database file are cached and for 6865 ** how long. 6866 ** 6867 ** The alternative page cache mechanism is an 6868 ** extreme measure that is only needed by the most demanding applications. 6869 ** The built-in page cache is recommended for most uses. 6870 ** 6871 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 6872 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 6873 ** the application may discard the parameter after the call to 6874 ** [sqlite3_config()] returns.)^ 6875 ** 6876 ** [[the xInit() page cache method]] 6877 ** ^(The xInit() method is called once for each effective 6878 ** call to [sqlite3_initialize()])^ 6879 ** (usually only once during the lifetime of the process). ^(The xInit() 6880 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 6881 ** The intent of the xInit() method is to set up global data structures 6882 ** required by the custom page cache implementation. 6883 ** ^(If the xInit() method is NULL, then the 6884 ** built-in default page cache is used instead of the application defined 6885 ** page cache.)^ 6886 ** 6887 ** [[the xShutdown() page cache method]] 6888 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 6889 ** It can be used to clean up 6890 ** any outstanding resources before process shutdown, if required. 6891 ** ^The xShutdown() method may be NULL. 6892 ** 6893 ** ^SQLite automatically serializes calls to the xInit method, 6894 ** so the xInit method need not be threadsafe. ^The 6895 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 6896 ** not need to be threadsafe either. All other methods must be threadsafe 6897 ** in multithreaded applications. 6898 ** 6899 ** ^SQLite will never invoke xInit() more than once without an intervening 6900 ** call to xShutdown(). 6901 ** 6902 ** [[the xCreate() page cache methods]] 6903 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 6904 ** SQLite will typically create one cache instance for each open database file, 6905 ** though this is not guaranteed. ^The 6906 ** first parameter, szPage, is the size in bytes of the pages that must 6907 ** be allocated by the cache. ^szPage will always a power of two. ^The 6908 ** second parameter szExtra is a number of bytes of extra storage 6909 ** associated with each page cache entry. ^The szExtra parameter will 6910 ** a number less than 250. SQLite will use the 6911 ** extra szExtra bytes on each page to store metadata about the underlying 6912 ** database page on disk. The value passed into szExtra depends 6913 ** on the SQLite version, the target platform, and how SQLite was compiled. 6914 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 6915 ** created will be used to cache database pages of a file stored on disk, or 6916 ** false if it is used for an in-memory database. The cache implementation 6917 ** does not have to do anything special based with the value of bPurgeable; 6918 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 6919 ** never invoke xUnpin() except to deliberately delete a page. 6920 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 6921 ** false will always have the "discard" flag set to true. 6922 ** ^Hence, a cache created with bPurgeable false will 6923 ** never contain any unpinned pages. 6924 ** 6925 ** [[the xCachesize() page cache method]] 6926 ** ^(The xCachesize() method may be called at any time by SQLite to set the 6927 ** suggested maximum cache-size (number of pages stored by) the cache 6928 ** instance passed as the first argument. This is the value configured using 6929 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 6930 ** parameter, the implementation is not required to do anything with this 6931 ** value; it is advisory only. 6932 ** 6933 ** [[the xPagecount() page cache methods]] 6934 ** The xPagecount() method must return the number of pages currently 6935 ** stored in the cache, both pinned and unpinned. 6936 ** 6937 ** [[the xFetch() page cache methods]] 6938 ** The xFetch() method locates a page in the cache and returns a pointer to 6939 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 6940 ** The pBuf element of the returned sqlite3_pcache_page object will be a 6941 ** pointer to a buffer of szPage bytes used to store the content of a 6942 ** single database page. The pExtra element of sqlite3_pcache_page will be 6943 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 6944 ** for each entry in the page cache. 6945 ** 6946 ** The page to be fetched is determined by the key. ^The minimum key value 6947 ** is 1. After it has been retrieved using xFetch, the page is considered 6948 ** to be "pinned". 6949 ** 6950 ** If the requested page is already in the page cache, then the page cache 6951 ** implementation must return a pointer to the page buffer with its content 6952 ** intact. If the requested page is not already in the cache, then the 6953 ** cache implementation should use the value of the createFlag 6954 ** parameter to help it determined what action to take: 6955 ** 6956 ** <table border=1 width=85% align=center> 6957 ** <tr><th> createFlag <th> Behavior when page is not already in cache 6958 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 6959 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 6960 ** Otherwise return NULL. 6961 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 6962 ** NULL if allocating a new page is effectively impossible. 6963 ** </table> 6964 ** 6965 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 6966 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 6967 ** failed.)^ In between the to xFetch() calls, SQLite may 6968 ** attempt to unpin one or more cache pages by spilling the content of 6969 ** pinned pages to disk and synching the operating system disk cache. 6970 ** 6971 ** [[the xUnpin() page cache method]] 6972 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 6973 ** as its second argument. If the third parameter, discard, is non-zero, 6974 ** then the page must be evicted from the cache. 6975 ** ^If the discard parameter is 6976 ** zero, then the page may be discarded or retained at the discretion of 6977 ** page cache implementation. ^The page cache implementation 6978 ** may choose to evict unpinned pages at any time. 6979 ** 6980 ** The cache must not perform any reference counting. A single 6981 ** call to xUnpin() unpins the page regardless of the number of prior calls 6982 ** to xFetch(). 6983 ** 6984 ** [[the xRekey() page cache methods]] 6985 ** The xRekey() method is used to change the key value associated with the 6986 ** page passed as the second argument. If the cache 6987 ** previously contains an entry associated with newKey, it must be 6988 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 6989 ** to be pinned. 6990 ** 6991 ** When SQLite calls the xTruncate() method, the cache must discard all 6992 ** existing cache entries with page numbers (keys) greater than or equal 6993 ** to the value of the iLimit parameter passed to xTruncate(). If any 6994 ** of these pages are pinned, they are implicitly unpinned, meaning that 6995 ** they can be safely discarded. 6996 ** 6997 ** [[the xDestroy() page cache method]] 6998 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 6999 ** All resources associated with the specified cache should be freed. ^After 7000 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 7001 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 7002 ** functions. 7003 ** 7004 ** [[the xShrink() page cache method]] 7005 ** ^SQLite invokes the xShrink() method when it wants the page cache to 7006 ** free up as much of heap memory as possible. The page cache implementation 7007 ** is not obligated to free any memory, but well-behaved implementations should 7008 ** do their best. 7009 */ 7010 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 7011 struct sqlite3_pcache_methods2 { 7012 int iVersion; 7013 void *pArg; 7014 int (*xInit)(void*); 7015 void (*xShutdown)(void*); 7016 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 7017 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7018 int (*xPagecount)(sqlite3_pcache*); 7019 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7020 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 7021 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 7022 unsigned oldKey, unsigned newKey); 7023 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7024 void (*xDestroy)(sqlite3_pcache*); 7025 void (*xShrink)(sqlite3_pcache*); 7026 }; 7027 7028 /* 7029 ** This is the obsolete pcache_methods object that has now been replaced 7030 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 7031 ** retained in the header file for backwards compatibility only. 7032 */ 7033 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 7034 struct sqlite3_pcache_methods { 7035 void *pArg; 7036 int (*xInit)(void*); 7037 void (*xShutdown)(void*); 7038 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 7039 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7040 int (*xPagecount)(sqlite3_pcache*); 7041 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7042 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 7043 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 7044 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7045 void (*xDestroy)(sqlite3_pcache*); 7046 }; 7047 7048 7049 /* 7050 ** CAPI3REF: Online Backup Object 7051 ** 7052 ** The sqlite3_backup object records state information about an ongoing 7053 ** online backup operation. ^The sqlite3_backup object is created by 7054 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 7055 ** [sqlite3_backup_finish()]. 7056 ** 7057 ** See Also: [Using the SQLite Online Backup API] 7058 */ 7059 typedef struct sqlite3_backup sqlite3_backup; 7060 7061 /* 7062 ** CAPI3REF: Online Backup API. 7063 ** 7064 ** The backup API copies the content of one database into another. 7065 ** It is useful either for creating backups of databases or 7066 ** for copying in-memory databases to or from persistent files. 7067 ** 7068 ** See Also: [Using the SQLite Online Backup API] 7069 ** 7070 ** ^SQLite holds a write transaction open on the destination database file 7071 ** for the duration of the backup operation. 7072 ** ^The source database is read-locked only while it is being read; 7073 ** it is not locked continuously for the entire backup operation. 7074 ** ^Thus, the backup may be performed on a live source database without 7075 ** preventing other database connections from 7076 ** reading or writing to the source database while the backup is underway. 7077 ** 7078 ** ^(To perform a backup operation: 7079 ** <ol> 7080 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 7081 ** backup, 7082 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 7083 ** the data between the two databases, and finally 7084 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 7085 ** associated with the backup operation. 7086 ** </ol>)^ 7087 ** There should be exactly one call to sqlite3_backup_finish() for each 7088 ** successful call to sqlite3_backup_init(). 7089 ** 7090 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 7091 ** 7092 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 7093 ** [database connection] associated with the destination database 7094 ** and the database name, respectively. 7095 ** ^The database name is "main" for the main database, "temp" for the 7096 ** temporary database, or the name specified after the AS keyword in 7097 ** an [ATTACH] statement for an attached database. 7098 ** ^The S and M arguments passed to 7099 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 7100 ** and database name of the source database, respectively. 7101 ** ^The source and destination [database connections] (parameters S and D) 7102 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 7103 ** an error. 7104 ** 7105 ** ^A call to sqlite3_backup_init() will fail, returning SQLITE_ERROR, if 7106 ** there is already a read or read-write transaction open on the 7107 ** destination database. 7108 ** 7109 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 7110 ** returned and an error code and error message are stored in the 7111 ** destination [database connection] D. 7112 ** ^The error code and message for the failed call to sqlite3_backup_init() 7113 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 7114 ** [sqlite3_errmsg16()] functions. 7115 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 7116 ** [sqlite3_backup] object. 7117 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 7118 ** sqlite3_backup_finish() functions to perform the specified backup 7119 ** operation. 7120 ** 7121 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 7122 ** 7123 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 7124 ** the source and destination databases specified by [sqlite3_backup] object B. 7125 ** ^If N is negative, all remaining source pages are copied. 7126 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 7127 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 7128 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 7129 ** from source to destination, then it returns [SQLITE_DONE]. 7130 ** ^If an error occurs while running sqlite3_backup_step(B,N), 7131 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 7132 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 7133 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 7134 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 7135 ** 7136 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 7137 ** <ol> 7138 ** <li> the destination database was opened read-only, or 7139 ** <li> the destination database is using write-ahead-log journaling 7140 ** and the destination and source page sizes differ, or 7141 ** <li> the destination database is an in-memory database and the 7142 ** destination and source page sizes differ. 7143 ** </ol>)^ 7144 ** 7145 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 7146 ** the [sqlite3_busy_handler | busy-handler function] 7147 ** is invoked (if one is specified). ^If the 7148 ** busy-handler returns non-zero before the lock is available, then 7149 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 7150 ** sqlite3_backup_step() can be retried later. ^If the source 7151 ** [database connection] 7152 ** is being used to write to the source database when sqlite3_backup_step() 7153 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 7154 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 7155 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 7156 ** [SQLITE_READONLY] is returned, then 7157 ** there is no point in retrying the call to sqlite3_backup_step(). These 7158 ** errors are considered fatal.)^ The application must accept 7159 ** that the backup operation has failed and pass the backup operation handle 7160 ** to the sqlite3_backup_finish() to release associated resources. 7161 ** 7162 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 7163 ** on the destination file. ^The exclusive lock is not released until either 7164 ** sqlite3_backup_finish() is called or the backup operation is complete 7165 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 7166 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 7167 ** lasts for the duration of the sqlite3_backup_step() call. 7168 ** ^Because the source database is not locked between calls to 7169 ** sqlite3_backup_step(), the source database may be modified mid-way 7170 ** through the backup process. ^If the source database is modified by an 7171 ** external process or via a database connection other than the one being 7172 ** used by the backup operation, then the backup will be automatically 7173 ** restarted by the next call to sqlite3_backup_step(). ^If the source 7174 ** database is modified by the using the same database connection as is used 7175 ** by the backup operation, then the backup database is automatically 7176 ** updated at the same time. 7177 ** 7178 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 7179 ** 7180 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 7181 ** application wishes to abandon the backup operation, the application 7182 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 7183 ** ^The sqlite3_backup_finish() interfaces releases all 7184 ** resources associated with the [sqlite3_backup] object. 7185 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 7186 ** active write-transaction on the destination database is rolled back. 7187 ** The [sqlite3_backup] object is invalid 7188 ** and may not be used following a call to sqlite3_backup_finish(). 7189 ** 7190 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 7191 ** sqlite3_backup_step() errors occurred, regardless or whether or not 7192 ** sqlite3_backup_step() completed. 7193 ** ^If an out-of-memory condition or IO error occurred during any prior 7194 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 7195 ** sqlite3_backup_finish() returns the corresponding [error code]. 7196 ** 7197 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 7198 ** is not a permanent error and does not affect the return value of 7199 ** sqlite3_backup_finish(). 7200 ** 7201 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 7202 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 7203 ** 7204 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 7205 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 7206 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 7207 ** in the source database at the conclusion of the most recent 7208 ** sqlite3_backup_step(). 7209 ** ^(The values returned by these functions are only updated by 7210 ** sqlite3_backup_step(). If the source database is modified in a way that 7211 ** changes the size of the source database or the number of pages remaining, 7212 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 7213 ** and sqlite3_backup_remaining() until after the next 7214 ** sqlite3_backup_step().)^ 7215 ** 7216 ** <b>Concurrent Usage of Database Handles</b> 7217 ** 7218 ** ^The source [database connection] may be used by the application for other 7219 ** purposes while a backup operation is underway or being initialized. 7220 ** ^If SQLite is compiled and configured to support threadsafe database 7221 ** connections, then the source database connection may be used concurrently 7222 ** from within other threads. 7223 ** 7224 ** However, the application must guarantee that the destination 7225 ** [database connection] is not passed to any other API (by any thread) after 7226 ** sqlite3_backup_init() is called and before the corresponding call to 7227 ** sqlite3_backup_finish(). SQLite does not currently check to see 7228 ** if the application incorrectly accesses the destination [database connection] 7229 ** and so no error code is reported, but the operations may malfunction 7230 ** nevertheless. Use of the destination database connection while a 7231 ** backup is in progress might also also cause a mutex deadlock. 7232 ** 7233 ** If running in [shared cache mode], the application must 7234 ** guarantee that the shared cache used by the destination database 7235 ** is not accessed while the backup is running. In practice this means 7236 ** that the application must guarantee that the disk file being 7237 ** backed up to is not accessed by any connection within the process, 7238 ** not just the specific connection that was passed to sqlite3_backup_init(). 7239 ** 7240 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 7241 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 7242 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 7243 ** APIs are not strictly speaking threadsafe. If they are invoked at the 7244 ** same time as another thread is invoking sqlite3_backup_step() it is 7245 ** possible that they return invalid values. 7246 */ 7247 SQLITE_API sqlite3_backup *SQLITE_STDCALL sqlite3_backup_init( 7248 sqlite3 *pDest, /* Destination database handle */ 7249 const char *zDestName, /* Destination database name */ 7250 sqlite3 *pSource, /* Source database handle */ 7251 const char *zSourceName /* Source database name */ 7252 ); 7253 SQLITE_API int SQLITE_STDCALL sqlite3_backup_step(sqlite3_backup *p, int nPage); 7254 SQLITE_API int SQLITE_STDCALL sqlite3_backup_finish(sqlite3_backup *p); 7255 SQLITE_API int SQLITE_STDCALL sqlite3_backup_remaining(sqlite3_backup *p); 7256 SQLITE_API int SQLITE_STDCALL sqlite3_backup_pagecount(sqlite3_backup *p); 7257 7258 /* 7259 ** CAPI3REF: Unlock Notification 7260 ** METHOD: sqlite3 7261 ** 7262 ** ^When running in shared-cache mode, a database operation may fail with 7263 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 7264 ** individual tables within the shared-cache cannot be obtained. See 7265 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 7266 ** ^This API may be used to register a callback that SQLite will invoke 7267 ** when the connection currently holding the required lock relinquishes it. 7268 ** ^This API is only available if the library was compiled with the 7269 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 7270 ** 7271 ** See Also: [Using the SQLite Unlock Notification Feature]. 7272 ** 7273 ** ^Shared-cache locks are released when a database connection concludes 7274 ** its current transaction, either by committing it or rolling it back. 7275 ** 7276 ** ^When a connection (known as the blocked connection) fails to obtain a 7277 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 7278 ** identity of the database connection (the blocking connection) that 7279 ** has locked the required resource is stored internally. ^After an 7280 ** application receives an SQLITE_LOCKED error, it may call the 7281 ** sqlite3_unlock_notify() method with the blocked connection handle as 7282 ** the first argument to register for a callback that will be invoked 7283 ** when the blocking connections current transaction is concluded. ^The 7284 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 7285 ** call that concludes the blocking connections transaction. 7286 ** 7287 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 7288 ** there is a chance that the blocking connection will have already 7289 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 7290 ** If this happens, then the specified callback is invoked immediately, 7291 ** from within the call to sqlite3_unlock_notify().)^ 7292 ** 7293 ** ^If the blocked connection is attempting to obtain a write-lock on a 7294 ** shared-cache table, and more than one other connection currently holds 7295 ** a read-lock on the same table, then SQLite arbitrarily selects one of 7296 ** the other connections to use as the blocking connection. 7297 ** 7298 ** ^(There may be at most one unlock-notify callback registered by a 7299 ** blocked connection. If sqlite3_unlock_notify() is called when the 7300 ** blocked connection already has a registered unlock-notify callback, 7301 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 7302 ** called with a NULL pointer as its second argument, then any existing 7303 ** unlock-notify callback is canceled. ^The blocked connections 7304 ** unlock-notify callback may also be canceled by closing the blocked 7305 ** connection using [sqlite3_close()]. 7306 ** 7307 ** The unlock-notify callback is not reentrant. If an application invokes 7308 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 7309 ** crash or deadlock may be the result. 7310 ** 7311 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 7312 ** returns SQLITE_OK. 7313 ** 7314 ** <b>Callback Invocation Details</b> 7315 ** 7316 ** When an unlock-notify callback is registered, the application provides a 7317 ** single void* pointer that is passed to the callback when it is invoked. 7318 ** However, the signature of the callback function allows SQLite to pass 7319 ** it an array of void* context pointers. The first argument passed to 7320 ** an unlock-notify callback is a pointer to an array of void* pointers, 7321 ** and the second is the number of entries in the array. 7322 ** 7323 ** When a blocking connections transaction is concluded, there may be 7324 ** more than one blocked connection that has registered for an unlock-notify 7325 ** callback. ^If two or more such blocked connections have specified the 7326 ** same callback function, then instead of invoking the callback function 7327 ** multiple times, it is invoked once with the set of void* context pointers 7328 ** specified by the blocked connections bundled together into an array. 7329 ** This gives the application an opportunity to prioritize any actions 7330 ** related to the set of unblocked database connections. 7331 ** 7332 ** <b>Deadlock Detection</b> 7333 ** 7334 ** Assuming that after registering for an unlock-notify callback a 7335 ** database waits for the callback to be issued before taking any further 7336 ** action (a reasonable assumption), then using this API may cause the 7337 ** application to deadlock. For example, if connection X is waiting for 7338 ** connection Y's transaction to be concluded, and similarly connection 7339 ** Y is waiting on connection X's transaction, then neither connection 7340 ** will proceed and the system may remain deadlocked indefinitely. 7341 ** 7342 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 7343 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 7344 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 7345 ** unlock-notify callback is registered. The system is said to be in 7346 ** a deadlocked state if connection A has registered for an unlock-notify 7347 ** callback on the conclusion of connection B's transaction, and connection 7348 ** B has itself registered for an unlock-notify callback when connection 7349 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 7350 ** the system is also considered to be deadlocked if connection B has 7351 ** registered for an unlock-notify callback on the conclusion of connection 7352 ** C's transaction, where connection C is waiting on connection A. ^Any 7353 ** number of levels of indirection are allowed. 7354 ** 7355 ** <b>The "DROP TABLE" Exception</b> 7356 ** 7357 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 7358 ** always appropriate to call sqlite3_unlock_notify(). There is however, 7359 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 7360 ** SQLite checks if there are any currently executing SELECT statements 7361 ** that belong to the same connection. If there are, SQLITE_LOCKED is 7362 ** returned. In this case there is no "blocking connection", so invoking 7363 ** sqlite3_unlock_notify() results in the unlock-notify callback being 7364 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 7365 ** or "DROP INDEX" query, an infinite loop might be the result. 7366 ** 7367 ** One way around this problem is to check the extended error code returned 7368 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 7369 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 7370 ** the special "DROP TABLE/INDEX" case, the extended error code is just 7371 ** SQLITE_LOCKED.)^ 7372 */ 7373 SQLITE_API int SQLITE_STDCALL sqlite3_unlock_notify( 7374 sqlite3 *pBlocked, /* Waiting connection */ 7375 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 7376 void *pNotifyArg /* Argument to pass to xNotify */ 7377 ); 7378 7379 7380 /* 7381 ** CAPI3REF: String Comparison 7382 ** 7383 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7384 ** and extensions to compare the contents of two buffers containing UTF-8 7385 ** strings in a case-independent fashion, using the same definition of "case 7386 ** independence" that SQLite uses internally when comparing identifiers. 7387 */ 7388 SQLITE_API int SQLITE_STDCALL sqlite3_stricmp(const char *, const char *); 7389 SQLITE_API int SQLITE_STDCALL sqlite3_strnicmp(const char *, const char *, int); 7390 7391 /* 7392 ** CAPI3REF: String Globbing 7393 * 7394 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 7395 ** string X matches the [GLOB] pattern P. 7396 ** ^The definition of [GLOB] pattern matching used in 7397 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7398 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 7399 ** is case sensitive. 7400 ** 7401 ** Note that this routine returns zero on a match and non-zero if the strings 7402 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7403 ** 7404 ** See also: [sqlite3_strlike()]. 7405 */ 7406 SQLITE_API int SQLITE_STDCALL sqlite3_strglob(const char *zGlob, const char *zStr); 7407 7408 /* 7409 ** CAPI3REF: String LIKE Matching 7410 * 7411 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 7412 ** string X matches the [LIKE] pattern P with escape character E. 7413 ** ^The definition of [LIKE] pattern matching used in 7414 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 7415 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 7416 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 7417 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 7418 ** insensitive - equivalent upper and lower case ASCII characters match 7419 ** one another. 7420 ** 7421 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 7422 ** only ASCII characters are case folded. 7423 ** 7424 ** Note that this routine returns zero on a match and non-zero if the strings 7425 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7426 ** 7427 ** See also: [sqlite3_strglob()]. 7428 */ 7429 SQLITE_API int SQLITE_STDCALL sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 7430 7431 /* 7432 ** CAPI3REF: Error Logging Interface 7433 ** 7434 ** ^The [sqlite3_log()] interface writes a message into the [error log] 7435 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7436 ** ^If logging is enabled, the zFormat string and subsequent arguments are 7437 ** used with [sqlite3_snprintf()] to generate the final output string. 7438 ** 7439 ** The sqlite3_log() interface is intended for use by extensions such as 7440 ** virtual tables, collating functions, and SQL functions. While there is 7441 ** nothing to prevent an application from calling sqlite3_log(), doing so 7442 ** is considered bad form. 7443 ** 7444 ** The zFormat string must not be NULL. 7445 ** 7446 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7447 ** will not use dynamically allocated memory. The log message is stored in 7448 ** a fixed-length buffer on the stack. If the log message is longer than 7449 ** a few hundred characters, it will be truncated to the length of the 7450 ** buffer. 7451 */ 7452 SQLITE_API void SQLITE_CDECL sqlite3_log(int iErrCode, const char *zFormat, ...); 7453 7454 /* 7455 ** CAPI3REF: Write-Ahead Log Commit Hook 7456 ** METHOD: sqlite3 7457 ** 7458 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 7459 ** is invoked each time data is committed to a database in wal mode. 7460 ** 7461 ** ^(The callback is invoked by SQLite after the commit has taken place and 7462 ** the associated write-lock on the database released)^, so the implementation 7463 ** may read, write or [checkpoint] the database as required. 7464 ** 7465 ** ^The first parameter passed to the callback function when it is invoked 7466 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 7467 ** registering the callback. ^The second is a copy of the database handle. 7468 ** ^The third parameter is the name of the database that was written to - 7469 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 7470 ** is the number of pages currently in the write-ahead log file, 7471 ** including those that were just committed. 7472 ** 7473 ** The callback function should normally return [SQLITE_OK]. ^If an error 7474 ** code is returned, that error will propagate back up through the 7475 ** SQLite code base to cause the statement that provoked the callback 7476 ** to report an error, though the commit will have still occurred. If the 7477 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 7478 ** that does not correspond to any valid SQLite error code, the results 7479 ** are undefined. 7480 ** 7481 ** A single database handle may have at most a single write-ahead log callback 7482 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 7483 ** previously registered write-ahead log callback. ^Note that the 7484 ** [sqlite3_wal_autocheckpoint()] interface and the 7485 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 7486 ** those overwrite any prior [sqlite3_wal_hook()] settings. 7487 */ 7488 SQLITE_API void *SQLITE_STDCALL sqlite3_wal_hook( 7489 sqlite3*, 7490 int(*)(void *,sqlite3*,const char*,int), 7491 void* 7492 ); 7493 7494 /* 7495 ** CAPI3REF: Configure an auto-checkpoint 7496 ** METHOD: sqlite3 7497 ** 7498 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 7499 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 7500 ** to automatically [checkpoint] 7501 ** after committing a transaction if there are N or 7502 ** more frames in the [write-ahead log] file. ^Passing zero or 7503 ** a negative value as the nFrame parameter disables automatic 7504 ** checkpoints entirely. 7505 ** 7506 ** ^The callback registered by this function replaces any existing callback 7507 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 7508 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 7509 ** configured by this function. 7510 ** 7511 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 7512 ** from SQL. 7513 ** 7514 ** ^Checkpoints initiated by this mechanism are 7515 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 7516 ** 7517 ** ^Every new [database connection] defaults to having the auto-checkpoint 7518 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 7519 ** pages. The use of this interface 7520 ** is only necessary if the default setting is found to be suboptimal 7521 ** for a particular application. 7522 */ 7523 SQLITE_API int SQLITE_STDCALL sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 7524 7525 /* 7526 ** CAPI3REF: Checkpoint a database 7527 ** METHOD: sqlite3 7528 ** 7529 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 7530 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 7531 ** 7532 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 7533 ** [write-ahead log] for database X on [database connection] D to be 7534 ** transferred into the database file and for the write-ahead log to 7535 ** be reset. See the [checkpointing] documentation for addition 7536 ** information. 7537 ** 7538 ** This interface used to be the only way to cause a checkpoint to 7539 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 7540 ** interface was added. This interface is retained for backwards 7541 ** compatibility and as a convenience for applications that need to manually 7542 ** start a callback but which do not need the full power (and corresponding 7543 ** complication) of [sqlite3_wal_checkpoint_v2()]. 7544 */ 7545 SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 7546 7547 /* 7548 ** CAPI3REF: Checkpoint a database 7549 ** METHOD: sqlite3 7550 ** 7551 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 7552 ** operation on database X of [database connection] D in mode M. Status 7553 ** information is written back into integers pointed to by L and C.)^ 7554 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 7555 ** 7556 ** <dl> 7557 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7558 ** ^Checkpoint as many frames as possible without waiting for any database 7559 ** readers or writers to finish, then sync the database file if all frames 7560 ** in the log were checkpointed. ^The [busy-handler callback] 7561 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 7562 ** ^On the other hand, passive mode might leave the checkpoint unfinished 7563 ** if there are concurrent readers or writers. 7564 ** 7565 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 7566 ** ^This mode blocks (it invokes the 7567 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 7568 ** database writer and all readers are reading from the most recent database 7569 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 7570 ** database file. ^This mode blocks new database writers while it is pending, 7571 ** but new database readers are allowed to continue unimpeded. 7572 ** 7573 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7574 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 7575 ** that after checkpointing the log file it blocks (calls the 7576 ** [busy-handler callback]) 7577 ** until all readers are reading from the database file only. ^This ensures 7578 ** that the next writer will restart the log file from the beginning. 7579 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 7580 ** database writer attempts while it is pending, but does not impede readers. 7581 ** 7582 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 7583 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 7584 ** addition that it also truncates the log file to zero bytes just prior 7585 ** to a successful return. 7586 ** </dl> 7587 ** 7588 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 7589 ** the log file or to -1 if the checkpoint could not run because 7590 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 7591 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 7592 ** log file (including any that were already checkpointed before the function 7593 ** was called) or to -1 if the checkpoint could not run due to an error or 7594 ** because the database is not in WAL mode. ^Note that upon successful 7595 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 7596 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 7597 ** 7598 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 7599 ** any other process is running a checkpoint operation at the same time, the 7600 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 7601 ** busy-handler configured, it will not be invoked in this case. 7602 ** 7603 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 7604 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 7605 ** obtained immediately, and a busy-handler is configured, it is invoked and 7606 ** the writer lock retried until either the busy-handler returns 0 or the lock 7607 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 7608 ** database readers as described above. ^If the busy-handler returns 0 before 7609 ** the writer lock is obtained or while waiting for database readers, the 7610 ** checkpoint operation proceeds from that point in the same way as 7611 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7612 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 7613 ** 7614 ** ^If parameter zDb is NULL or points to a zero length string, then the 7615 ** specified operation is attempted on all WAL databases [attached] to 7616 ** [database connection] db. In this case the 7617 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 7618 ** an SQLITE_BUSY error is encountered when processing one or more of the 7619 ** attached WAL databases, the operation is still attempted on any remaining 7620 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 7621 ** error occurs while processing an attached database, processing is abandoned 7622 ** and the error code is returned to the caller immediately. ^If no error 7623 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7624 ** databases, SQLITE_OK is returned. 7625 ** 7626 ** ^If database zDb is the name of an attached database that is not in WAL 7627 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 7628 ** zDb is not NULL (or a zero length string) and is not the name of any 7629 ** attached database, SQLITE_ERROR is returned to the caller. 7630 ** 7631 ** ^Unless it returns SQLITE_MISUSE, 7632 ** the sqlite3_wal_checkpoint_v2() interface 7633 ** sets the error information that is queried by 7634 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 7635 ** 7636 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 7637 ** from SQL. 7638 */ 7639 SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint_v2( 7640 sqlite3 *db, /* Database handle */ 7641 const char *zDb, /* Name of attached database (or NULL) */ 7642 int eMode, /* SQLITE_CHECKPOINT_* value */ 7643 int *pnLog, /* OUT: Size of WAL log in frames */ 7644 int *pnCkpt /* OUT: Total number of frames checkpointed */ 7645 ); 7646 7647 /* 7648 ** CAPI3REF: Checkpoint Mode Values 7649 ** KEYWORDS: {checkpoint mode} 7650 ** 7651 ** These constants define all valid values for the "checkpoint mode" passed 7652 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 7653 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 7654 ** meaning of each of these checkpoint modes. 7655 */ 7656 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 7657 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 7658 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 7659 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 7660 7661 /* 7662 ** CAPI3REF: Virtual Table Interface Configuration 7663 ** 7664 ** This function may be called by either the [xConnect] or [xCreate] method 7665 ** of a [virtual table] implementation to configure 7666 ** various facets of the virtual table interface. 7667 ** 7668 ** If this interface is invoked outside the context of an xConnect or 7669 ** xCreate virtual table method then the behavior is undefined. 7670 ** 7671 ** At present, there is only one option that may be configured using 7672 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7673 ** may be added in the future. 7674 */ 7675 SQLITE_API int SQLITE_CDECL sqlite3_vtab_config(sqlite3*, int op, ...); 7676 7677 /* 7678 ** CAPI3REF: Virtual Table Configuration Options 7679 ** 7680 ** These macros define the various options to the 7681 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 7682 ** can use to customize and optimize their behavior. 7683 ** 7684 ** <dl> 7685 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7686 ** <dd>Calls of the form 7687 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 7688 ** where X is an integer. If X is zero, then the [virtual table] whose 7689 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 7690 ** support constraints. In this configuration (which is the default) if 7691 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 7692 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 7693 ** specified as part of the users SQL statement, regardless of the actual 7694 ** ON CONFLICT mode specified. 7695 ** 7696 ** If X is non-zero, then the virtual table implementation guarantees 7697 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 7698 ** any modifications to internal or persistent data structures have been made. 7699 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 7700 ** is able to roll back a statement or database transaction, and abandon 7701 ** or continue processing the current SQL statement as appropriate. 7702 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 7703 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 7704 ** had been ABORT. 7705 ** 7706 ** Virtual table implementations that are required to handle OR REPLACE 7707 ** must do so within the [xUpdate] method. If a call to the 7708 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 7709 ** CONFLICT policy is REPLACE, the virtual table implementation should 7710 ** silently replace the appropriate rows within the xUpdate callback and 7711 ** return SQLITE_OK. Or, if this is not possible, it may return 7712 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 7713 ** constraint handling. 7714 ** </dl> 7715 */ 7716 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 7717 7718 /* 7719 ** CAPI3REF: Determine The Virtual Table Conflict Policy 7720 ** 7721 ** This function may only be called from within a call to the [xUpdate] method 7722 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 7723 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 7724 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 7725 ** of the SQL statement that triggered the call to the [xUpdate] method of the 7726 ** [virtual table]. 7727 */ 7728 SQLITE_API int SQLITE_STDCALL sqlite3_vtab_on_conflict(sqlite3 *); 7729 7730 /* 7731 ** CAPI3REF: Conflict resolution modes 7732 ** KEYWORDS: {conflict resolution mode} 7733 ** 7734 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 7735 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 7736 ** is for the SQL statement being evaluated. 7737 ** 7738 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 7739 ** return value from the [sqlite3_set_authorizer()] callback and that 7740 ** [SQLITE_ABORT] is also a [result code]. 7741 */ 7742 #define SQLITE_ROLLBACK 1 7743 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 7744 #define SQLITE_FAIL 3 7745 /* #define SQLITE_ABORT 4 // Also an error code */ 7746 #define SQLITE_REPLACE 5 7747 7748 /* 7749 ** CAPI3REF: Prepared Statement Scan Status Opcodes 7750 ** KEYWORDS: {scanstatus options} 7751 ** 7752 ** The following constants can be used for the T parameter to the 7753 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 7754 ** different metric for sqlite3_stmt_scanstatus() to return. 7755 ** 7756 ** When the value returned to V is a string, space to hold that string is 7757 ** managed by the prepared statement S and will be automatically freed when 7758 ** S is finalized. 7759 ** 7760 ** <dl> 7761 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 7762 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 7763 ** set to the total number of times that the X-th loop has run.</dd> 7764 ** 7765 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 7766 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 7767 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 7768 ** 7769 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 7770 ** <dd>^The "double" variable pointed to by the T parameter will be set to the 7771 ** query planner's estimate for the average number of rows output from each 7772 ** iteration of the X-th loop. If the query planner's estimates was accurate, 7773 ** then this value will approximate the quotient NVISIT/NLOOP and the 7774 ** product of this value for all prior loops with the same SELECTID will 7775 ** be the NLOOP value for the current loop. 7776 ** 7777 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 7778 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 7779 ** to a zero-terminated UTF-8 string containing the name of the index or table 7780 ** used for the X-th loop. 7781 ** 7782 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 7783 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 7784 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 7785 ** description for the X-th loop. 7786 ** 7787 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 7788 ** <dd>^The "int" variable pointed to by the T parameter will be set to the 7789 ** "select-id" for the X-th loop. The select-id identifies which query or 7790 ** subquery the loop is part of. The main query has a select-id of zero. 7791 ** The select-id is the same value as is output in the first column 7792 ** of an [EXPLAIN QUERY PLAN] query. 7793 ** </dl> 7794 */ 7795 #define SQLITE_SCANSTAT_NLOOP 0 7796 #define SQLITE_SCANSTAT_NVISIT 1 7797 #define SQLITE_SCANSTAT_EST 2 7798 #define SQLITE_SCANSTAT_NAME 3 7799 #define SQLITE_SCANSTAT_EXPLAIN 4 7800 #define SQLITE_SCANSTAT_SELECTID 5 7801 7802 /* 7803 ** CAPI3REF: Prepared Statement Scan Status 7804 ** METHOD: sqlite3_stmt 7805 ** 7806 ** This interface returns information about the predicted and measured 7807 ** performance for pStmt. Advanced applications can use this 7808 ** interface to compare the predicted and the measured performance and 7809 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 7810 ** 7811 ** Since this interface is expected to be rarely used, it is only 7812 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 7813 ** compile-time option. 7814 ** 7815 ** The "iScanStatusOp" parameter determines which status information to return. 7816 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 7817 ** of this interface is undefined. 7818 ** ^The requested measurement is written into a variable pointed to by 7819 ** the "pOut" parameter. 7820 ** Parameter "idx" identifies the specific loop to retrieve statistics for. 7821 ** Loops are numbered starting from zero. ^If idx is out of range - less than 7822 ** zero or greater than or equal to the total number of loops used to implement 7823 ** the statement - a non-zero value is returned and the variable that pOut 7824 ** points to is unchanged. 7825 ** 7826 ** ^Statistics might not be available for all loops in all statements. ^In cases 7827 ** where there exist loops with no available statistics, this function behaves 7828 ** as if the loop did not exist - it returns non-zero and leave the variable 7829 ** that pOut points to unchanged. 7830 ** 7831 ** See also: [sqlite3_stmt_scanstatus_reset()] 7832 */ 7833 SQLITE_API int SQLITE_STDCALL sqlite3_stmt_scanstatus( 7834 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 7835 int idx, /* Index of loop to report on */ 7836 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 7837 void *pOut /* Result written here */ 7838 ); 7839 7840 /* 7841 ** CAPI3REF: Zero Scan-Status Counters 7842 ** METHOD: sqlite3_stmt 7843 ** 7844 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 7845 ** 7846 ** This API is only available if the library is built with pre-processor 7847 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 7848 */ 7849 SQLITE_API void SQLITE_STDCALL sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 7850 7851 /* 7852 ** CAPI3REF: Flush caches to disk mid-transaction 7853 ** 7854 ** ^If a write-transaction is open on [database connection] D when the 7855 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 7856 ** pages in the pager-cache that are not currently in use are written out 7857 ** to disk. A dirty page may be in use if a database cursor created by an 7858 ** active SQL statement is reading from it, or if it is page 1 of a database 7859 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 7860 ** interface flushes caches for all schemas - "main", "temp", and 7861 ** any [attached] databases. 7862 ** 7863 ** ^If this function needs to obtain extra database locks before dirty pages 7864 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 7865 ** immediately and there is a busy-handler callback configured, it is invoked 7866 ** in the usual manner. ^If the required lock still cannot be obtained, then 7867 ** the database is skipped and an attempt made to flush any dirty pages 7868 ** belonging to the next (if any) database. ^If any databases are skipped 7869 ** because locks cannot be obtained, but no other error occurs, this 7870 ** function returns SQLITE_BUSY. 7871 ** 7872 ** ^If any other error occurs while flushing dirty pages to disk (for 7873 ** example an IO error or out-of-memory condition), then processing is 7874 ** abandoned and an SQLite [error code] is returned to the caller immediately. 7875 ** 7876 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 7877 ** 7878 ** ^This function does not set the database handle error code or message 7879 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 7880 */ 7881 SQLITE_API int SQLITE_STDCALL sqlite3_db_cacheflush(sqlite3*); 7882 7883 /* 7884 ** CAPI3REF: Database Snapshot 7885 ** KEYWORDS: {snapshot} 7886 ** EXPERIMENTAL 7887 ** 7888 ** An instance of the snapshot object records the state of a [WAL mode] 7889 ** database for some specific point in history. 7890 ** 7891 ** In [WAL mode], multiple [database connections] that are open on the 7892 ** same database file can each be reading a different historical version 7893 ** of the database file. When a [database connection] begins a read 7894 ** transaction, that connection sees an unchanging copy of the database 7895 ** as it existed for the point in time when the transaction first started. 7896 ** Subsequent changes to the database from other connections are not seen 7897 ** by the reader until a new read transaction is started. 7898 ** 7899 ** The sqlite3_snapshot object records state information about an historical 7900 ** version of the database file so that it is possible to later open a new read 7901 ** transaction that sees that historical version of the database rather than 7902 ** the most recent version. 7903 ** 7904 ** The constructor for this object is [sqlite3_snapshot_get()]. The 7905 ** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer 7906 ** to an historical snapshot (if possible). The destructor for 7907 ** sqlite3_snapshot objects is [sqlite3_snapshot_free()]. 7908 */ 7909 typedef struct sqlite3_snapshot sqlite3_snapshot; 7910 7911 /* 7912 ** CAPI3REF: Record A Database Snapshot 7913 ** EXPERIMENTAL 7914 ** 7915 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 7916 ** new [sqlite3_snapshot] object that records the current state of 7917 ** schema S in database connection D. ^On success, the 7918 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 7919 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 7920 ** ^If schema S of [database connection] D is not a [WAL mode] database 7921 ** that is in a read transaction, then [sqlite3_snapshot_get(D,S,P)] 7922 ** leaves the *P value unchanged and returns an appropriate [error code]. 7923 ** 7924 ** The [sqlite3_snapshot] object returned from a successful call to 7925 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 7926 ** to avoid a memory leak. 7927 ** 7928 ** The [sqlite3_snapshot_get()] interface is only available when the 7929 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 7930 */ 7931 SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_snapshot_get( 7932 sqlite3 *db, 7933 const char *zSchema, 7934 sqlite3_snapshot **ppSnapshot 7935 ); 7936 7937 /* 7938 ** CAPI3REF: Start a read transaction on an historical snapshot 7939 ** EXPERIMENTAL 7940 ** 7941 ** ^The [sqlite3_snapshot_open(D,S,P)] interface attempts to move the 7942 ** read transaction that is currently open on schema S of 7943 ** [database connection] D so that it refers to historical [snapshot] P. 7944 ** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success 7945 ** or an appropriate [error code] if it fails. 7946 ** 7947 ** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be 7948 ** the first operation, apart from other sqlite3_snapshot_open() calls, 7949 ** following the [BEGIN] that starts a new read transaction. 7950 ** ^A [snapshot] will fail to open if it has been overwritten by a 7951 ** [checkpoint]. 7952 ** 7953 ** The [sqlite3_snapshot_open()] interface is only available when the 7954 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 7955 */ 7956 SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_snapshot_open( 7957 sqlite3 *db, 7958 const char *zSchema, 7959 sqlite3_snapshot *pSnapshot 7960 ); 7961 7962 /* 7963 ** CAPI3REF: Destroy a snapshot 7964 ** EXPERIMENTAL 7965 ** 7966 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 7967 ** The application must eventually free every [sqlite3_snapshot] object 7968 ** using this routine to avoid a memory leak. 7969 ** 7970 ** The [sqlite3_snapshot_free()] interface is only available when the 7971 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 7972 */ 7973 SQLITE_API SQLITE_EXPERIMENTAL void SQLITE_STDCALL sqlite3_snapshot_free(sqlite3_snapshot*); 7974 7975 /* 7976 ** Undo the hack that converts floating point types to integer for 7977 ** builds on processors without floating point support. 7978 */ 7979 #ifdef SQLITE_OMIT_FLOATING_POINT 7980 # undef double 7981 #endif 7982 7983 #ifdef __cplusplus 7984 } /* End of the 'extern "C"' block */ 7985 #endif 7986 #endif /* _SQLITE3_H_ */ 7987 7988 /* 7989 ** 2010 August 30 7990 ** 7991 ** The author disclaims copyright to this source code. In place of 7992 ** a legal notice, here is a blessing: 7993 ** 7994 ** May you do good and not evil. 7995 ** May you find forgiveness for yourself and forgive others. 7996 ** May you share freely, never taking more than you give. 7997 ** 7998 ************************************************************************* 7999 */ 8000 8001 #ifndef _SQLITE3RTREE_H_ 8002 #define _SQLITE3RTREE_H_ 8003 8004 8005 #ifdef __cplusplus 8006 extern "C" { 8007 #endif 8008 8009 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 8010 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 8011 8012 /* The double-precision datatype used by RTree depends on the 8013 ** SQLITE_RTREE_INT_ONLY compile-time option. 8014 */ 8015 #ifdef SQLITE_RTREE_INT_ONLY 8016 typedef sqlite3_int64 sqlite3_rtree_dbl; 8017 #else 8018 typedef double sqlite3_rtree_dbl; 8019 #endif 8020 8021 /* 8022 ** Register a geometry callback named zGeom that can be used as part of an 8023 ** R-Tree geometry query as follows: 8024 ** 8025 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 8026 */ 8027 SQLITE_API int SQLITE_STDCALL sqlite3_rtree_geometry_callback( 8028 sqlite3 *db, 8029 const char *zGeom, 8030 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 8031 void *pContext 8032 ); 8033 8034 8035 /* 8036 ** A pointer to a structure of the following type is passed as the first 8037 ** argument to callbacks registered using rtree_geometry_callback(). 8038 */ 8039 struct sqlite3_rtree_geometry { 8040 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 8041 int nParam; /* Size of array aParam[] */ 8042 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 8043 void *pUser; /* Callback implementation user data */ 8044 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 8045 }; 8046 8047 /* 8048 ** Register a 2nd-generation geometry callback named zScore that can be 8049 ** used as part of an R-Tree geometry query as follows: 8050 ** 8051 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 8052 */ 8053 SQLITE_API int SQLITE_STDCALL sqlite3_rtree_query_callback( 8054 sqlite3 *db, 8055 const char *zQueryFunc, 8056 int (*xQueryFunc)(sqlite3_rtree_query_info*), 8057 void *pContext, 8058 void (*xDestructor)(void*) 8059 ); 8060 8061 8062 /* 8063 ** A pointer to a structure of the following type is passed as the 8064 ** argument to scored geometry callback registered using 8065 ** sqlite3_rtree_query_callback(). 8066 ** 8067 ** Note that the first 5 fields of this structure are identical to 8068 ** sqlite3_rtree_geometry. This structure is a subclass of 8069 ** sqlite3_rtree_geometry. 8070 */ 8071 struct sqlite3_rtree_query_info { 8072 void *pContext; /* pContext from when function registered */ 8073 int nParam; /* Number of function parameters */ 8074 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 8075 void *pUser; /* callback can use this, if desired */ 8076 void (*xDelUser)(void*); /* function to free pUser */ 8077 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 8078 unsigned int *anQueue; /* Number of pending entries in the queue */ 8079 int nCoord; /* Number of coordinates */ 8080 int iLevel; /* Level of current node or entry */ 8081 int mxLevel; /* The largest iLevel value in the tree */ 8082 sqlite3_int64 iRowid; /* Rowid for current entry */ 8083 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 8084 int eParentWithin; /* Visibility of parent node */ 8085 int eWithin; /* OUT: Visiblity */ 8086 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 8087 /* The following fields are only available in 3.8.11 and later */ 8088 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 8089 }; 8090 8091 /* 8092 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 8093 */ 8094 #define NOT_WITHIN 0 /* Object completely outside of query region */ 8095 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 8096 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 8097 8098 8099 #ifdef __cplusplus 8100 } /* end of the 'extern "C"' block */ 8101 #endif 8102 8103 #endif /* ifndef _SQLITE3RTREE_H_ */ 8104 8105 /* 8106 ** 2014 May 31 8107 ** 8108 ** The author disclaims copyright to this source code. In place of 8109 ** a legal notice, here is a blessing: 8110 ** 8111 ** May you do good and not evil. 8112 ** May you find forgiveness for yourself and forgive others. 8113 ** May you share freely, never taking more than you give. 8114 ** 8115 ****************************************************************************** 8116 ** 8117 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 8118 ** FTS5 may be extended with: 8119 ** 8120 ** * custom tokenizers, and 8121 ** * custom auxiliary functions. 8122 */ 8123 8124 8125 #ifndef _FTS5_H 8126 #define _FTS5_H 8127 8128 8129 #ifdef __cplusplus 8130 extern "C" { 8131 #endif 8132 8133 /************************************************************************* 8134 ** CUSTOM AUXILIARY FUNCTIONS 8135 ** 8136 ** Virtual table implementations may overload SQL functions by implementing 8137 ** the sqlite3_module.xFindFunction() method. 8138 */ 8139 8140 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 8141 typedef struct Fts5Context Fts5Context; 8142 typedef struct Fts5PhraseIter Fts5PhraseIter; 8143 8144 typedef void (*fts5_extension_function)( 8145 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 8146 Fts5Context *pFts, /* First arg to pass to pApi functions */ 8147 sqlite3_context *pCtx, /* Context for returning result/error */ 8148 int nVal, /* Number of values in apVal[] array */ 8149 sqlite3_value **apVal /* Array of trailing arguments */ 8150 ); 8151 8152 struct Fts5PhraseIter { 8153 const unsigned char *a; 8154 const unsigned char *b; 8155 }; 8156 8157 /* 8158 ** EXTENSION API FUNCTIONS 8159 ** 8160 ** xUserData(pFts): 8161 ** Return a copy of the context pointer the extension function was 8162 ** registered with. 8163 ** 8164 ** xColumnTotalSize(pFts, iCol, pnToken): 8165 ** If parameter iCol is less than zero, set output variable *pnToken 8166 ** to the total number of tokens in the FTS5 table. Or, if iCol is 8167 ** non-negative but less than the number of columns in the table, return 8168 ** the total number of tokens in column iCol, considering all rows in 8169 ** the FTS5 table. 8170 ** 8171 ** If parameter iCol is greater than or equal to the number of columns 8172 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 8173 ** an OOM condition or IO error), an appropriate SQLite error code is 8174 ** returned. 8175 ** 8176 ** xColumnCount(pFts): 8177 ** Return the number of columns in the table. 8178 ** 8179 ** xColumnSize(pFts, iCol, pnToken): 8180 ** If parameter iCol is less than zero, set output variable *pnToken 8181 ** to the total number of tokens in the current row. Or, if iCol is 8182 ** non-negative but less than the number of columns in the table, set 8183 ** *pnToken to the number of tokens in column iCol of the current row. 8184 ** 8185 ** If parameter iCol is greater than or equal to the number of columns 8186 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 8187 ** an OOM condition or IO error), an appropriate SQLite error code is 8188 ** returned. 8189 ** 8190 ** xColumnText: 8191 ** This function attempts to retrieve the text of column iCol of the 8192 ** current document. If successful, (*pz) is set to point to a buffer 8193 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 8194 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 8195 ** if an error occurs, an SQLite error code is returned and the final values 8196 ** of (*pz) and (*pn) are undefined. 8197 ** 8198 ** xPhraseCount: 8199 ** Returns the number of phrases in the current query expression. 8200 ** 8201 ** xPhraseSize: 8202 ** Returns the number of tokens in phrase iPhrase of the query. Phrases 8203 ** are numbered starting from zero. 8204 ** 8205 ** xInstCount: 8206 ** Set *pnInst to the total number of occurrences of all phrases within 8207 ** the query within the current row. Return SQLITE_OK if successful, or 8208 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 8209 ** 8210 ** xInst: 8211 ** Query for the details of phrase match iIdx within the current row. 8212 ** Phrase matches are numbered starting from zero, so the iIdx argument 8213 ** should be greater than or equal to zero and smaller than the value 8214 ** output by xInstCount(). 8215 ** 8216 ** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM) 8217 ** if an error occurs. 8218 ** 8219 ** xRowid: 8220 ** Returns the rowid of the current row. 8221 ** 8222 ** xTokenize: 8223 ** Tokenize text using the tokenizer belonging to the FTS5 table. 8224 ** 8225 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 8226 ** This API function is used to query the FTS table for phrase iPhrase 8227 ** of the current query. Specifically, a query equivalent to: 8228 ** 8229 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 8230 ** 8231 ** with $p set to a phrase equivalent to the phrase iPhrase of the 8232 ** current query is executed. For each row visited, the callback function 8233 ** passed as the fourth argument is invoked. The context and API objects 8234 ** passed to the callback function may be used to access the properties of 8235 ** each matched row. Invoking Api.xUserData() returns a copy of the pointer 8236 ** passed as the third argument to pUserData. 8237 ** 8238 ** If the callback function returns any value other than SQLITE_OK, the 8239 ** query is abandoned and the xQueryPhrase function returns immediately. 8240 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 8241 ** Otherwise, the error code is propagated upwards. 8242 ** 8243 ** If the query runs to completion without incident, SQLITE_OK is returned. 8244 ** Or, if some error occurs before the query completes or is aborted by 8245 ** the callback, an SQLite error code is returned. 8246 ** 8247 ** 8248 ** xSetAuxdata(pFts5, pAux, xDelete) 8249 ** 8250 ** Save the pointer passed as the second argument as the extension functions 8251 ** "auxiliary data". The pointer may then be retrieved by the current or any 8252 ** future invocation of the same fts5 extension function made as part of 8253 ** of the same MATCH query using the xGetAuxdata() API. 8254 ** 8255 ** Each extension function is allocated a single auxiliary data slot for 8256 ** each FTS query (MATCH expression). If the extension function is invoked 8257 ** more than once for a single FTS query, then all invocations share a 8258 ** single auxiliary data context. 8259 ** 8260 ** If there is already an auxiliary data pointer when this function is 8261 ** invoked, then it is replaced by the new pointer. If an xDelete callback 8262 ** was specified along with the original pointer, it is invoked at this 8263 ** point. 8264 ** 8265 ** The xDelete callback, if one is specified, is also invoked on the 8266 ** auxiliary data pointer after the FTS5 query has finished. 8267 ** 8268 ** If an error (e.g. an OOM condition) occurs within this function, an 8269 ** the auxiliary data is set to NULL and an error code returned. If the 8270 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 8271 ** pointer before returning. 8272 ** 8273 ** 8274 ** xGetAuxdata(pFts5, bClear) 8275 ** 8276 ** Returns the current auxiliary data pointer for the fts5 extension 8277 ** function. See the xSetAuxdata() method for details. 8278 ** 8279 ** If the bClear argument is non-zero, then the auxiliary data is cleared 8280 ** (set to NULL) before this function returns. In this case the xDelete, 8281 ** if any, is not invoked. 8282 ** 8283 ** 8284 ** xRowCount(pFts5, pnRow) 8285 ** 8286 ** This function is used to retrieve the total number of rows in the table. 8287 ** In other words, the same value that would be returned by: 8288 ** 8289 ** SELECT count(*) FROM ftstable; 8290 ** 8291 ** xPhraseFirst() 8292 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 8293 ** method, to iterate through all instances of a single query phrase within 8294 ** the current row. This is the same information as is accessible via the 8295 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 8296 ** to use, this API may be faster under some circumstances. To iterate 8297 ** through instances of phrase iPhrase, use the following code: 8298 ** 8299 ** Fts5PhraseIter iter; 8300 ** int iCol, iOff; 8301 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 8302 ** iOff>=0; 8303 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 8304 ** ){ 8305 ** // An instance of phrase iPhrase at offset iOff of column iCol 8306 ** } 8307 ** 8308 ** The Fts5PhraseIter structure is defined above. Applications should not 8309 ** modify this structure directly - it should only be used as shown above 8310 ** with the xPhraseFirst() and xPhraseNext() API methods. 8311 ** 8312 ** xPhraseNext() 8313 ** See xPhraseFirst above. 8314 */ 8315 struct Fts5ExtensionApi { 8316 int iVersion; /* Currently always set to 1 */ 8317 8318 void *(*xUserData)(Fts5Context*); 8319 8320 int (*xColumnCount)(Fts5Context*); 8321 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 8322 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 8323 8324 int (*xTokenize)(Fts5Context*, 8325 const char *pText, int nText, /* Text to tokenize */ 8326 void *pCtx, /* Context passed to xToken() */ 8327 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 8328 ); 8329 8330 int (*xPhraseCount)(Fts5Context*); 8331 int (*xPhraseSize)(Fts5Context*, int iPhrase); 8332 8333 int (*xInstCount)(Fts5Context*, int *pnInst); 8334 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 8335 8336 sqlite3_int64 (*xRowid)(Fts5Context*); 8337 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 8338 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 8339 8340 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 8341 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 8342 ); 8343 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 8344 void *(*xGetAuxdata)(Fts5Context*, int bClear); 8345 8346 void (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 8347 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 8348 }; 8349 8350 /* 8351 ** CUSTOM AUXILIARY FUNCTIONS 8352 *************************************************************************/ 8353 8354 /************************************************************************* 8355 ** CUSTOM TOKENIZERS 8356 ** 8357 ** Applications may also register custom tokenizer types. A tokenizer 8358 ** is registered by providing fts5 with a populated instance of the 8359 ** following structure. All structure methods must be defined, setting 8360 ** any member of the fts5_tokenizer struct to NULL leads to undefined 8361 ** behaviour. The structure methods are expected to function as follows: 8362 ** 8363 ** xCreate: 8364 ** This function is used to allocate and inititalize a tokenizer instance. 8365 ** A tokenizer instance is required to actually tokenize text. 8366 ** 8367 ** The first argument passed to this function is a copy of the (void*) 8368 ** pointer provided by the application when the fts5_tokenizer object 8369 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 8370 ** The second and third arguments are an array of nul-terminated strings 8371 ** containing the tokenizer arguments, if any, specified following the 8372 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 8373 ** to create the FTS5 table. 8374 ** 8375 ** The final argument is an output variable. If successful, (*ppOut) 8376 ** should be set to point to the new tokenizer handle and SQLITE_OK 8377 ** returned. If an error occurs, some value other than SQLITE_OK should 8378 ** be returned. In this case, fts5 assumes that the final value of *ppOut 8379 ** is undefined. 8380 ** 8381 ** xDelete: 8382 ** This function is invoked to delete a tokenizer handle previously 8383 ** allocated using xCreate(). Fts5 guarantees that this function will 8384 ** be invoked exactly once for each successful call to xCreate(). 8385 ** 8386 ** xTokenize: 8387 ** This function is expected to tokenize the nText byte string indicated 8388 ** by argument pText. pText may or may not be nul-terminated. The first 8389 ** argument passed to this function is a pointer to an Fts5Tokenizer object 8390 ** returned by an earlier call to xCreate(). 8391 ** 8392 ** The second argument indicates the reason that FTS5 is requesting 8393 ** tokenization of the supplied text. This is always one of the following 8394 ** four values: 8395 ** 8396 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 8397 ** or removed from the FTS table. The tokenizer is being invoked to 8398 ** determine the set of tokens to add to (or delete from) the 8399 ** FTS index. 8400 ** 8401 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 8402 ** against the FTS index. The tokenizer is being called to tokenize 8403 ** a bareword or quoted string specified as part of the query. 8404 ** 8405 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 8406 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 8407 ** followed by a "*" character, indicating that the last token 8408 ** returned by the tokenizer will be treated as a token prefix. 8409 ** 8410 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 8411 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 8412 ** function. Or an fts5_api.xColumnSize() request made by the same 8413 ** on a columnsize=0 database. 8414 ** </ul> 8415 ** 8416 ** For each token in the input string, the supplied callback xToken() must 8417 ** be invoked. The first argument to it should be a copy of the pointer 8418 ** passed as the second argument to xTokenize(). The third and fourth 8419 ** arguments are a pointer to a buffer containing the token text, and the 8420 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 8421 ** of the first byte of and first byte immediately following the text from 8422 ** which the token is derived within the input. 8423 ** 8424 ** The second argument passed to the xToken() callback ("tflags") should 8425 ** normally be set to 0. The exception is if the tokenizer supports 8426 ** synonyms. In this case see the discussion below for details. 8427 ** 8428 ** FTS5 assumes the xToken() callback is invoked for each token in the 8429 ** order that they occur within the input text. 8430 ** 8431 ** If an xToken() callback returns any value other than SQLITE_OK, then 8432 ** the tokenization should be abandoned and the xTokenize() method should 8433 ** immediately return a copy of the xToken() return value. Or, if the 8434 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 8435 ** if an error occurs with the xTokenize() implementation itself, it 8436 ** may abandon the tokenization and return any error code other than 8437 ** SQLITE_OK or SQLITE_DONE. 8438 ** 8439 ** SYNONYM SUPPORT 8440 ** 8441 ** Custom tokenizers may also support synonyms. Consider a case in which a 8442 ** user wishes to query for a phrase such as "first place". Using the 8443 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 8444 ** of "first place" within the document set, but not alternative forms 8445 ** such as "1st place". In some applications, it would be better to match 8446 ** all instances of "first place" or "1st place" regardless of which form 8447 ** the user specified in the MATCH query text. 8448 ** 8449 ** There are several ways to approach this in FTS5: 8450 ** 8451 ** <ol><li> By mapping all synonyms to a single token. In this case, the 8452 ** In the above example, this means that the tokenizer returns the 8453 ** same token for inputs "first" and "1st". Say that token is in 8454 ** fact "first", so that when the user inserts the document "I won 8455 ** 1st place" entries are added to the index for tokens "i", "won", 8456 ** "first" and "place". If the user then queries for '1st + place', 8457 ** the tokenizer substitutes "first" for "1st" and the query works 8458 ** as expected. 8459 ** 8460 ** <li> By adding multiple synonyms for a single term to the FTS index. 8461 ** In this case, when tokenizing query text, the tokenizer may 8462 ** provide multiple synonyms for a single term within the document. 8463 ** FTS5 then queries the index for each synonym individually. For 8464 ** example, faced with the query: 8465 ** 8466 ** <codeblock> 8467 ** ... MATCH 'first place'</codeblock> 8468 ** 8469 ** the tokenizer offers both "1st" and "first" as synonyms for the 8470 ** first token in the MATCH query and FTS5 effectively runs a query 8471 ** similar to: 8472 ** 8473 ** <codeblock> 8474 ** ... MATCH '(first OR 1st) place'</codeblock> 8475 ** 8476 ** except that, for the purposes of auxiliary functions, the query 8477 ** still appears to contain just two phrases - "(first OR 1st)" 8478 ** being treated as a single phrase. 8479 ** 8480 ** <li> By adding multiple synonyms for a single term to the FTS index. 8481 ** Using this method, when tokenizing document text, the tokenizer 8482 ** provides multiple synonyms for each token. So that when a 8483 ** document such as "I won first place" is tokenized, entries are 8484 ** added to the FTS index for "i", "won", "first", "1st" and 8485 ** "place". 8486 ** 8487 ** This way, even if the tokenizer does not provide synonyms 8488 ** when tokenizing query text (it should not - to do would be 8489 ** inefficient), it doesn't matter if the user queries for 8490 ** 'first + place' or '1st + place', as there are entires in the 8491 ** FTS index corresponding to both forms of the first token. 8492 ** </ol> 8493 ** 8494 ** Whether it is parsing document or query text, any call to xToken that 8495 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 8496 ** is considered to supply a synonym for the previous token. For example, 8497 ** when parsing the document "I won first place", a tokenizer that supports 8498 ** synonyms would call xToken() 5 times, as follows: 8499 ** 8500 ** <codeblock> 8501 ** xToken(pCtx, 0, "i", 1, 0, 1); 8502 ** xToken(pCtx, 0, "won", 3, 2, 5); 8503 ** xToken(pCtx, 0, "first", 5, 6, 11); 8504 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 8505 ** xToken(pCtx, 0, "place", 5, 12, 17); 8506 **</codeblock> 8507 ** 8508 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 8509 ** xToken() is called. Multiple synonyms may be specified for a single token 8510 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 8511 ** There is no limit to the number of synonyms that may be provided for a 8512 ** single token. 8513 ** 8514 ** In many cases, method (1) above is the best approach. It does not add 8515 ** extra data to the FTS index or require FTS5 to query for multiple terms, 8516 ** so it is efficient in terms of disk space and query speed. However, it 8517 ** does not support prefix queries very well. If, as suggested above, the 8518 ** token "first" is subsituted for "1st" by the tokenizer, then the query: 8519 ** 8520 ** <codeblock> 8521 ** ... MATCH '1s*'</codeblock> 8522 ** 8523 ** will not match documents that contain the token "1st" (as the tokenizer 8524 ** will probably not map "1s" to any prefix of "first"). 8525 ** 8526 ** For full prefix support, method (3) may be preferred. In this case, 8527 ** because the index contains entries for both "first" and "1st", prefix 8528 ** queries such as 'fi*' or '1s*' will match correctly. However, because 8529 ** extra entries are added to the FTS index, this method uses more space 8530 ** within the database. 8531 ** 8532 ** Method (2) offers a midpoint between (1) and (3). Using this method, 8533 ** a query such as '1s*' will match documents that contain the literal 8534 ** token "1st", but not "first" (assuming the tokenizer is not able to 8535 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 8536 ** will match against "1st" and "first". This method does not require 8537 ** extra disk space, as no extra entries are added to the FTS index. 8538 ** On the other hand, it may require more CPU cycles to run MATCH queries, 8539 ** as separate queries of the FTS index are required for each synonym. 8540 ** 8541 ** When using methods (2) or (3), it is important that the tokenizer only 8542 ** provide synonyms when tokenizing document text (method (2)) or query 8543 ** text (method (3)), not both. Doing so will not cause any errors, but is 8544 ** inefficient. 8545 */ 8546 typedef struct Fts5Tokenizer Fts5Tokenizer; 8547 typedef struct fts5_tokenizer fts5_tokenizer; 8548 struct fts5_tokenizer { 8549 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 8550 void (*xDelete)(Fts5Tokenizer*); 8551 int (*xTokenize)(Fts5Tokenizer*, 8552 void *pCtx, 8553 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 8554 const char *pText, int nText, 8555 int (*xToken)( 8556 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 8557 int tflags, /* Mask of FTS5_TOKEN_* flags */ 8558 const char *pToken, /* Pointer to buffer containing token */ 8559 int nToken, /* Size of token in bytes */ 8560 int iStart, /* Byte offset of token within input text */ 8561 int iEnd /* Byte offset of end of token within input text */ 8562 ) 8563 ); 8564 }; 8565 8566 /* Flags that may be passed as the third argument to xTokenize() */ 8567 #define FTS5_TOKENIZE_QUERY 0x0001 8568 #define FTS5_TOKENIZE_PREFIX 0x0002 8569 #define FTS5_TOKENIZE_DOCUMENT 0x0004 8570 #define FTS5_TOKENIZE_AUX 0x0008 8571 8572 /* Flags that may be passed by the tokenizer implementation back to FTS5 8573 ** as the third argument to the supplied xToken callback. */ 8574 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 8575 8576 /* 8577 ** END OF CUSTOM TOKENIZERS 8578 *************************************************************************/ 8579 8580 /************************************************************************* 8581 ** FTS5 EXTENSION REGISTRATION API 8582 */ 8583 typedef struct fts5_api fts5_api; 8584 struct fts5_api { 8585 int iVersion; /* Currently always set to 2 */ 8586 8587 /* Create a new tokenizer */ 8588 int (*xCreateTokenizer)( 8589 fts5_api *pApi, 8590 const char *zName, 8591 void *pContext, 8592 fts5_tokenizer *pTokenizer, 8593 void (*xDestroy)(void*) 8594 ); 8595 8596 /* Find an existing tokenizer */ 8597 int (*xFindTokenizer)( 8598 fts5_api *pApi, 8599 const char *zName, 8600 void **ppContext, 8601 fts5_tokenizer *pTokenizer 8602 ); 8603 8604 /* Create a new auxiliary function */ 8605 int (*xCreateFunction)( 8606 fts5_api *pApi, 8607 const char *zName, 8608 void *pContext, 8609 fts5_extension_function xFunction, 8610 void (*xDestroy)(void*) 8611 ); 8612 }; 8613 8614 /* 8615 ** END OF REGISTRATION API 8616 *************************************************************************/ 8617 8618 #ifdef __cplusplus 8619 } /* end of the 'extern "C"' block */ 8620 #endif 8621 8622 #endif /* _FTS5_H */ 8623 8624 8625