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 suppose 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 "3.8.9" 115 #define SQLITE_VERSION_NUMBER 3008009 116 #define SQLITE_SOURCE_ID "2015-04-08 12:16:33 8a8ffc862e96f57aa698f93de10dee28e69f6e09" 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 insure 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 ** 274 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 275 ** for the [sqlite3] object. 276 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 277 ** the [sqlite3] object is successfully destroyed and all associated 278 ** resources are deallocated. 279 ** 280 ** ^If the database connection is associated with unfinalized prepared 281 ** statements or unfinished sqlite3_backup objects then sqlite3_close() 282 ** will leave the database connection open and return [SQLITE_BUSY]. 283 ** ^If sqlite3_close_v2() is called with unfinalized prepared statements 284 ** and/or unfinished sqlite3_backups, then the database connection becomes 285 ** an unusable "zombie" which will automatically be deallocated when the 286 ** last prepared statement is finalized or the last sqlite3_backup is 287 ** finished. The sqlite3_close_v2() interface is intended for use with 288 ** host languages that are garbage collected, and where the order in which 289 ** destructors are called is arbitrary. 290 ** 291 ** Applications should [sqlite3_finalize | finalize] all [prepared statements], 292 ** [sqlite3_blob_close | close] all [BLOB handles], and 293 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 294 ** with the [sqlite3] object prior to attempting to close the object. ^If 295 ** sqlite3_close_v2() is called on a [database connection] that still has 296 ** outstanding [prepared statements], [BLOB handles], and/or 297 ** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 298 ** of resources is deferred until all [prepared statements], [BLOB handles], 299 ** and [sqlite3_backup] objects are also destroyed. 300 ** 301 ** ^If an [sqlite3] object is destroyed while a transaction is open, 302 ** the transaction is automatically rolled back. 303 ** 304 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 305 ** must be either a NULL 306 ** pointer or an [sqlite3] object pointer obtained 307 ** from [sqlite3_open()], [sqlite3_open16()], or 308 ** [sqlite3_open_v2()], and not previously closed. 309 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 310 ** argument is a harmless no-op. 311 */ 312 SQLITE_API int SQLITE_STDCALL sqlite3_close(sqlite3*); 313 SQLITE_API int SQLITE_STDCALL sqlite3_close_v2(sqlite3*); 314 315 /* 316 ** The type for a callback function. 317 ** This is legacy and deprecated. It is included for historical 318 ** compatibility and is not documented. 319 */ 320 typedef int (*sqlite3_callback)(void*,int,char**, char**); 321 322 /* 323 ** CAPI3REF: One-Step Query Execution Interface 324 ** 325 ** The sqlite3_exec() interface is a convenience wrapper around 326 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 327 ** that allows an application to run multiple statements of SQL 328 ** without having to use a lot of C code. 329 ** 330 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 331 ** semicolon-separate SQL statements passed into its 2nd argument, 332 ** in the context of the [database connection] passed in as its 1st 333 ** argument. ^If the callback function of the 3rd argument to 334 ** sqlite3_exec() is not NULL, then it is invoked for each result row 335 ** coming out of the evaluated SQL statements. ^The 4th argument to 336 ** sqlite3_exec() is relayed through to the 1st argument of each 337 ** callback invocation. ^If the callback pointer to sqlite3_exec() 338 ** is NULL, then no callback is ever invoked and result rows are 339 ** ignored. 340 ** 341 ** ^If an error occurs while evaluating the SQL statements passed into 342 ** sqlite3_exec(), then execution of the current statement stops and 343 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 344 ** is not NULL then any error message is written into memory obtained 345 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 346 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 347 ** on error message strings returned through the 5th parameter of 348 ** of sqlite3_exec() after the error message string is no longer needed. 349 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 350 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 351 ** NULL before returning. 352 ** 353 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 354 ** routine returns SQLITE_ABORT without invoking the callback again and 355 ** without running any subsequent SQL statements. 356 ** 357 ** ^The 2nd argument to the sqlite3_exec() callback function is the 358 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 359 ** callback is an array of pointers to strings obtained as if from 360 ** [sqlite3_column_text()], one for each column. ^If an element of a 361 ** result row is NULL then the corresponding string pointer for the 362 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 363 ** sqlite3_exec() callback is an array of pointers to strings where each 364 ** entry represents the name of corresponding result column as obtained 365 ** from [sqlite3_column_name()]. 366 ** 367 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 368 ** to an empty string, or a pointer that contains only whitespace and/or 369 ** SQL comments, then no SQL statements are evaluated and the database 370 ** is not changed. 371 ** 372 ** Restrictions: 373 ** 374 ** <ul> 375 ** <li> The application must insure that the 1st parameter to sqlite3_exec() 376 ** is a valid and open [database connection]. 377 ** <li> The application must not close the [database connection] specified by 378 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 379 ** <li> The application must not modify the SQL statement text passed into 380 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 381 ** </ul> 382 */ 383 SQLITE_API int SQLITE_STDCALL sqlite3_exec( 384 sqlite3*, /* An open database */ 385 const char *sql, /* SQL to be evaluated */ 386 int (*callback)(void*,int,char**,char**), /* Callback function */ 387 void *, /* 1st argument to callback */ 388 char **errmsg /* Error msg written here */ 389 ); 390 391 /* 392 ** CAPI3REF: Result Codes 393 ** KEYWORDS: {result code definitions} 394 ** 395 ** Many SQLite functions return an integer result code from the set shown 396 ** here in order to indicate success or failure. 397 ** 398 ** New error codes may be added in future versions of SQLite. 399 ** 400 ** See also: [extended result code definitions] 401 */ 402 #define SQLITE_OK 0 /* Successful result */ 403 /* beginning-of-error-codes */ 404 #define SQLITE_ERROR 1 /* SQL error or missing database */ 405 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 406 #define SQLITE_PERM 3 /* Access permission denied */ 407 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 408 #define SQLITE_BUSY 5 /* The database file is locked */ 409 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 410 #define SQLITE_NOMEM 7 /* A malloc() failed */ 411 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 412 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 413 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 414 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 415 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 416 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 417 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 418 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 419 #define SQLITE_EMPTY 16 /* Database is empty */ 420 #define SQLITE_SCHEMA 17 /* The database schema changed */ 421 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 422 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 423 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 424 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 425 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 426 #define SQLITE_AUTH 23 /* Authorization denied */ 427 #define SQLITE_FORMAT 24 /* Auxiliary database format error */ 428 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 429 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 430 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 431 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 432 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 433 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 434 /* end-of-error-codes */ 435 436 /* 437 ** CAPI3REF: Extended Result Codes 438 ** KEYWORDS: {extended result code definitions} 439 ** 440 ** In its default configuration, SQLite API routines return one of 30 integer 441 ** [result codes]. However, experience has shown that many of 442 ** these result codes are too coarse-grained. They do not provide as 443 ** much information about problems as programmers might like. In an effort to 444 ** address this, newer versions of SQLite (version 3.3.8 and later) include 445 ** support for additional result codes that provide more detailed information 446 ** about errors. These [extended result codes] are enabled or disabled 447 ** on a per database connection basis using the 448 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 449 ** the most recent error can be obtained using 450 ** [sqlite3_extended_errcode()]. 451 */ 452 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 453 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 454 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 455 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 456 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 457 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 458 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 459 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 460 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 461 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 462 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 463 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 464 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 465 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 466 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 467 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 468 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 469 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 470 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 471 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 472 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 473 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 474 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 475 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 476 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 477 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 478 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 479 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 480 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 481 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 482 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 483 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 484 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 485 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 486 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 487 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 488 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 489 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 490 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 491 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 492 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 493 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 494 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 495 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 496 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 497 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 498 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 499 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 500 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 501 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 502 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 503 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 504 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 505 506 /* 507 ** CAPI3REF: Flags For File Open Operations 508 ** 509 ** These bit values are intended for use in the 510 ** 3rd parameter to the [sqlite3_open_v2()] interface and 511 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 512 */ 513 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 514 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 515 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 516 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 517 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 518 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 519 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 520 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 521 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 522 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 523 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 524 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 525 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 526 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 527 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 528 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 529 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 530 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 531 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 532 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 533 534 /* Reserved: 0x00F00000 */ 535 536 /* 537 ** CAPI3REF: Device Characteristics 538 ** 539 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 540 ** object returns an integer which is a vector of these 541 ** bit values expressing I/O characteristics of the mass storage 542 ** device that holds the file that the [sqlite3_io_methods] 543 ** refers to. 544 ** 545 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 546 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 547 ** mean that writes of blocks that are nnn bytes in size and 548 ** are aligned to an address which is an integer multiple of 549 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 550 ** that when data is appended to a file, the data is appended 551 ** first then the size of the file is extended, never the other 552 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 553 ** information is written to disk in the same order as calls 554 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 555 ** after reboot following a crash or power loss, the only bytes in a 556 ** file that were written at the application level might have changed 557 ** and that adjacent bytes, even bytes within the same sector are 558 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 559 ** flag indicate that a file cannot be deleted when open. The 560 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 561 ** read-only media and cannot be changed even by processes with 562 ** elevated privileges. 563 */ 564 #define SQLITE_IOCAP_ATOMIC 0x00000001 565 #define SQLITE_IOCAP_ATOMIC512 0x00000002 566 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 567 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 568 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 569 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 570 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 571 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 572 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 573 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 574 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 575 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 576 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 577 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 578 579 /* 580 ** CAPI3REF: File Locking Levels 581 ** 582 ** SQLite uses one of these integer values as the second 583 ** argument to calls it makes to the xLock() and xUnlock() methods 584 ** of an [sqlite3_io_methods] object. 585 */ 586 #define SQLITE_LOCK_NONE 0 587 #define SQLITE_LOCK_SHARED 1 588 #define SQLITE_LOCK_RESERVED 2 589 #define SQLITE_LOCK_PENDING 3 590 #define SQLITE_LOCK_EXCLUSIVE 4 591 592 /* 593 ** CAPI3REF: Synchronization Type Flags 594 ** 595 ** When SQLite invokes the xSync() method of an 596 ** [sqlite3_io_methods] object it uses a combination of 597 ** these integer values as the second argument. 598 ** 599 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 600 ** sync operation only needs to flush data to mass storage. Inode 601 ** information need not be flushed. If the lower four bits of the flag 602 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 603 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 604 ** to use Mac OS X style fullsync instead of fsync(). 605 ** 606 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 607 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 608 ** settings. The [synchronous pragma] determines when calls to the 609 ** xSync VFS method occur and applies uniformly across all platforms. 610 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 611 ** energetic or rigorous or forceful the sync operations are and 612 ** only make a difference on Mac OSX for the default SQLite code. 613 ** (Third-party VFS implementations might also make the distinction 614 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 615 ** operating systems natively supported by SQLite, only Mac OSX 616 ** cares about the difference.) 617 */ 618 #define SQLITE_SYNC_NORMAL 0x00002 619 #define SQLITE_SYNC_FULL 0x00003 620 #define SQLITE_SYNC_DATAONLY 0x00010 621 622 /* 623 ** CAPI3REF: OS Interface Open File Handle 624 ** 625 ** An [sqlite3_file] object represents an open file in the 626 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 627 ** implementations will 628 ** want to subclass this object by appending additional fields 629 ** for their own use. The pMethods entry is a pointer to an 630 ** [sqlite3_io_methods] object that defines methods for performing 631 ** I/O operations on the open file. 632 */ 633 typedef struct sqlite3_file sqlite3_file; 634 struct sqlite3_file { 635 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 636 }; 637 638 /* 639 ** CAPI3REF: OS Interface File Virtual Methods Object 640 ** 641 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 642 ** [sqlite3_file] object (or, more commonly, a subclass of the 643 ** [sqlite3_file] object) with a pointer to an instance of this object. 644 ** This object defines the methods used to perform various operations 645 ** against the open file represented by the [sqlite3_file] object. 646 ** 647 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 648 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 649 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 650 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 651 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 652 ** to NULL. 653 ** 654 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 655 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 656 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 657 ** flag may be ORed in to indicate that only the data of the file 658 ** and not its inode needs to be synced. 659 ** 660 ** The integer values to xLock() and xUnlock() are one of 661 ** <ul> 662 ** <li> [SQLITE_LOCK_NONE], 663 ** <li> [SQLITE_LOCK_SHARED], 664 ** <li> [SQLITE_LOCK_RESERVED], 665 ** <li> [SQLITE_LOCK_PENDING], or 666 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 667 ** </ul> 668 ** xLock() increases the lock. xUnlock() decreases the lock. 669 ** The xCheckReservedLock() method checks whether any database connection, 670 ** either in this process or in some other process, is holding a RESERVED, 671 ** PENDING, or EXCLUSIVE lock on the file. It returns true 672 ** if such a lock exists and false otherwise. 673 ** 674 ** The xFileControl() method is a generic interface that allows custom 675 ** VFS implementations to directly control an open file using the 676 ** [sqlite3_file_control()] interface. The second "op" argument is an 677 ** integer opcode. The third argument is a generic pointer intended to 678 ** point to a structure that may contain arguments or space in which to 679 ** write return values. Potential uses for xFileControl() might be 680 ** functions to enable blocking locks with timeouts, to change the 681 ** locking strategy (for example to use dot-file locks), to inquire 682 ** about the status of a lock, or to break stale locks. The SQLite 683 ** core reserves all opcodes less than 100 for its own use. 684 ** A [file control opcodes | list of opcodes] less than 100 is available. 685 ** Applications that define a custom xFileControl method should use opcodes 686 ** greater than 100 to avoid conflicts. VFS implementations should 687 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 688 ** recognize. 689 ** 690 ** The xSectorSize() method returns the sector size of the 691 ** device that underlies the file. The sector size is the 692 ** minimum write that can be performed without disturbing 693 ** other bytes in the file. The xDeviceCharacteristics() 694 ** method returns a bit vector describing behaviors of the 695 ** underlying device: 696 ** 697 ** <ul> 698 ** <li> [SQLITE_IOCAP_ATOMIC] 699 ** <li> [SQLITE_IOCAP_ATOMIC512] 700 ** <li> [SQLITE_IOCAP_ATOMIC1K] 701 ** <li> [SQLITE_IOCAP_ATOMIC2K] 702 ** <li> [SQLITE_IOCAP_ATOMIC4K] 703 ** <li> [SQLITE_IOCAP_ATOMIC8K] 704 ** <li> [SQLITE_IOCAP_ATOMIC16K] 705 ** <li> [SQLITE_IOCAP_ATOMIC32K] 706 ** <li> [SQLITE_IOCAP_ATOMIC64K] 707 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 708 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 709 ** </ul> 710 ** 711 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 712 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 713 ** mean that writes of blocks that are nnn bytes in size and 714 ** are aligned to an address which is an integer multiple of 715 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 716 ** that when data is appended to a file, the data is appended 717 ** first then the size of the file is extended, never the other 718 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 719 ** information is written to disk in the same order as calls 720 ** to xWrite(). 721 ** 722 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 723 ** in the unread portions of the buffer with zeros. A VFS that 724 ** fails to zero-fill short reads might seem to work. However, 725 ** failure to zero-fill short reads will eventually lead to 726 ** database corruption. 727 */ 728 typedef struct sqlite3_io_methods sqlite3_io_methods; 729 struct sqlite3_io_methods { 730 int iVersion; 731 int (*xClose)(sqlite3_file*); 732 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 733 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 734 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 735 int (*xSync)(sqlite3_file*, int flags); 736 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 737 int (*xLock)(sqlite3_file*, int); 738 int (*xUnlock)(sqlite3_file*, int); 739 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 740 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 741 int (*xSectorSize)(sqlite3_file*); 742 int (*xDeviceCharacteristics)(sqlite3_file*); 743 /* Methods above are valid for version 1 */ 744 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 745 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 746 void (*xShmBarrier)(sqlite3_file*); 747 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 748 /* Methods above are valid for version 2 */ 749 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 750 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 751 /* Methods above are valid for version 3 */ 752 /* Additional methods may be added in future releases */ 753 }; 754 755 /* 756 ** CAPI3REF: Standard File Control Opcodes 757 ** KEYWORDS: {file control opcodes} {file control opcode} 758 ** 759 ** These integer constants are opcodes for the xFileControl method 760 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 761 ** interface. 762 ** 763 ** <ul> 764 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 765 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 766 ** opcode causes the xFileControl method to write the current state of 767 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 768 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 769 ** into an integer that the pArg argument points to. This capability 770 ** is used during testing and is only available when the SQLITE_TEST 771 ** compile-time option is used. 772 ** 773 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 774 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 775 ** layer a hint of how large the database file will grow to be during the 776 ** current transaction. This hint is not guaranteed to be accurate but it 777 ** is often close. The underlying VFS might choose to preallocate database 778 ** file space based on this hint in order to help writes to the database 779 ** file run faster. 780 ** 781 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 782 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 783 ** extends and truncates the database file in chunks of a size specified 784 ** by the user. The fourth argument to [sqlite3_file_control()] should 785 ** point to an integer (type int) containing the new chunk-size to use 786 ** for the nominated database. Allocating database file space in large 787 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 788 ** improve performance on some systems. 789 ** 790 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 791 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 792 ** to the [sqlite3_file] object associated with a particular database 793 ** connection. See the [sqlite3_file_control()] documentation for 794 ** additional information. 795 ** 796 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 797 ** No longer in use. 798 ** 799 ** <li>[[SQLITE_FCNTL_SYNC]] 800 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 801 ** sent to the VFS immediately before the xSync method is invoked on a 802 ** database file descriptor. Or, if the xSync method is not invoked 803 ** because the user has configured SQLite with 804 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 805 ** of the xSync method. In most cases, the pointer argument passed with 806 ** this file-control is NULL. However, if the database file is being synced 807 ** as part of a multi-database commit, the argument points to a nul-terminated 808 ** string containing the transactions master-journal file name. VFSes that 809 ** do not need this signal should silently ignore this opcode. Applications 810 ** should not call [sqlite3_file_control()] with this opcode as doing so may 811 ** disrupt the operation of the specialized VFSes that do require it. 812 ** 813 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 814 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 815 ** and sent to the VFS after a transaction has been committed immediately 816 ** but before the database is unlocked. VFSes that do not need this signal 817 ** should silently ignore this opcode. Applications should not call 818 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 819 ** operation of the specialized VFSes that do require it. 820 ** 821 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 822 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 823 ** retry counts and intervals for certain disk I/O operations for the 824 ** windows [VFS] in order to provide robustness in the presence of 825 ** anti-virus programs. By default, the windows VFS will retry file read, 826 ** file write, and file delete operations up to 10 times, with a delay 827 ** of 25 milliseconds before the first retry and with the delay increasing 828 ** by an additional 25 milliseconds with each subsequent retry. This 829 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 830 ** to be adjusted. The values are changed for all database connections 831 ** within the same process. The argument is a pointer to an array of two 832 ** integers where the first integer i the new retry count and the second 833 ** integer is the delay. If either integer is negative, then the setting 834 ** is not changed but instead the prior value of that setting is written 835 ** into the array entry, allowing the current retry settings to be 836 ** interrogated. The zDbName parameter is ignored. 837 ** 838 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 839 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 840 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 841 ** write ahead log and shared memory files used for transaction control 842 ** are automatically deleted when the latest connection to the database 843 ** closes. Setting persistent WAL mode causes those files to persist after 844 ** close. Persisting the files is useful when other processes that do not 845 ** have write permission on the directory containing the database file want 846 ** to read the database file, as the WAL and shared memory files must exist 847 ** in order for the database to be readable. The fourth parameter to 848 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 849 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 850 ** WAL mode. If the integer is -1, then it is overwritten with the current 851 ** WAL persistence setting. 852 ** 853 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 854 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 855 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 856 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 857 ** xDeviceCharacteristics methods. The fourth parameter to 858 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 859 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 860 ** mode. If the integer is -1, then it is overwritten with the current 861 ** zero-damage mode setting. 862 ** 863 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 864 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 865 ** a write transaction to indicate that, unless it is rolled back for some 866 ** reason, the entire database file will be overwritten by the current 867 ** transaction. This is used by VACUUM operations. 868 ** 869 ** <li>[[SQLITE_FCNTL_VFSNAME]] 870 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 871 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 872 ** final bottom-level VFS are written into memory obtained from 873 ** [sqlite3_malloc()] and the result is stored in the char* variable 874 ** that the fourth parameter of [sqlite3_file_control()] points to. 875 ** The caller is responsible for freeing the memory when done. As with 876 ** all file-control actions, there is no guarantee that this will actually 877 ** do anything. Callers should initialize the char* variable to a NULL 878 ** pointer in case this file-control is not implemented. This file-control 879 ** is intended for diagnostic use only. 880 ** 881 ** <li>[[SQLITE_FCNTL_PRAGMA]] 882 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 883 ** file control is sent to the open [sqlite3_file] object corresponding 884 ** to the database file to which the pragma statement refers. ^The argument 885 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 886 ** pointers to strings (char**) in which the second element of the array 887 ** is the name of the pragma and the third element is the argument to the 888 ** pragma or NULL if the pragma has no argument. ^The handler for an 889 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 890 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 891 ** or the equivalent and that string will become the result of the pragma or 892 ** the error message if the pragma fails. ^If the 893 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 894 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 895 ** file control returns [SQLITE_OK], then the parser assumes that the 896 ** VFS has handled the PRAGMA itself and the parser generates a no-op 897 ** prepared statement if result string is NULL, or that returns a copy 898 ** of the result string if the string is non-NULL. 899 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 900 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 901 ** that the VFS encountered an error while handling the [PRAGMA] and the 902 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 903 ** file control occurs at the beginning of pragma statement analysis and so 904 ** it is able to override built-in [PRAGMA] statements. 905 ** 906 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 907 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 908 ** file-control may be invoked by SQLite on the database file handle 909 ** shortly after it is opened in order to provide a custom VFS with access 910 ** to the connections busy-handler callback. The argument is of type (void **) 911 ** - an array of two (void *) values. The first (void *) actually points 912 ** to a function of type (int (*)(void *)). In order to invoke the connections 913 ** busy-handler, this function should be invoked with the second (void *) in 914 ** the array as the only argument. If it returns non-zero, then the operation 915 ** should be retried. If it returns zero, the custom VFS should abandon the 916 ** current operation. 917 ** 918 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 919 ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 920 ** to have SQLite generate a 921 ** temporary filename using the same algorithm that is followed to generate 922 ** temporary filenames for TEMP tables and other internal uses. The 923 ** argument should be a char** which will be filled with the filename 924 ** written into memory obtained from [sqlite3_malloc()]. The caller should 925 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 926 ** 927 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 928 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 929 ** maximum number of bytes that will be used for memory-mapped I/O. 930 ** The argument is a pointer to a value of type sqlite3_int64 that 931 ** is an advisory maximum number of bytes in the file to memory map. The 932 ** pointer is overwritten with the old value. The limit is not changed if 933 ** the value originally pointed to is negative, and so the current limit 934 ** can be queried by passing in a pointer to a negative number. This 935 ** file-control is used internally to implement [PRAGMA mmap_size]. 936 ** 937 ** <li>[[SQLITE_FCNTL_TRACE]] 938 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 939 ** to the VFS about what the higher layers of the SQLite stack are doing. 940 ** This file control is used by some VFS activity tracing [shims]. 941 ** The argument is a zero-terminated string. Higher layers in the 942 ** SQLite stack may generate instances of this file control if 943 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 944 ** 945 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 946 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 947 ** pointer to an integer and it writes a boolean into that integer depending 948 ** on whether or not the file has been renamed, moved, or deleted since it 949 ** was first opened. 950 ** 951 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 952 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 953 ** opcode causes the xFileControl method to swap the file handle with the one 954 ** pointed to by the pArg argument. This capability is used during testing 955 ** and only needs to be supported when SQLITE_TEST is defined. 956 ** 957 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 958 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 959 ** be advantageous to block on the next WAL lock if the lock is not immediately 960 ** available. The WAL subsystem issues this signal during rare 961 ** circumstances in order to fix a problem with priority inversion. 962 ** Applications should <em>not</em> use this file-control. 963 ** 964 ** </ul> 965 */ 966 #define SQLITE_FCNTL_LOCKSTATE 1 967 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 968 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 969 #define SQLITE_FCNTL_LAST_ERRNO 4 970 #define SQLITE_FCNTL_SIZE_HINT 5 971 #define SQLITE_FCNTL_CHUNK_SIZE 6 972 #define SQLITE_FCNTL_FILE_POINTER 7 973 #define SQLITE_FCNTL_SYNC_OMITTED 8 974 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 975 #define SQLITE_FCNTL_PERSIST_WAL 10 976 #define SQLITE_FCNTL_OVERWRITE 11 977 #define SQLITE_FCNTL_VFSNAME 12 978 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 979 #define SQLITE_FCNTL_PRAGMA 14 980 #define SQLITE_FCNTL_BUSYHANDLER 15 981 #define SQLITE_FCNTL_TEMPFILENAME 16 982 #define SQLITE_FCNTL_MMAP_SIZE 18 983 #define SQLITE_FCNTL_TRACE 19 984 #define SQLITE_FCNTL_HAS_MOVED 20 985 #define SQLITE_FCNTL_SYNC 21 986 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 987 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 988 #define SQLITE_FCNTL_WAL_BLOCK 24 989 990 /* deprecated names */ 991 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 992 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 993 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 994 995 996 /* 997 ** CAPI3REF: Mutex Handle 998 ** 999 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1000 ** abstract type for a mutex object. The SQLite core never looks 1001 ** at the internal representation of an [sqlite3_mutex]. It only 1002 ** deals with pointers to the [sqlite3_mutex] object. 1003 ** 1004 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1005 */ 1006 typedef struct sqlite3_mutex sqlite3_mutex; 1007 1008 /* 1009 ** CAPI3REF: OS Interface Object 1010 ** 1011 ** An instance of the sqlite3_vfs object defines the interface between 1012 ** the SQLite core and the underlying operating system. The "vfs" 1013 ** in the name of the object stands for "virtual file system". See 1014 ** the [VFS | VFS documentation] for further information. 1015 ** 1016 ** The value of the iVersion field is initially 1 but may be larger in 1017 ** future versions of SQLite. Additional fields may be appended to this 1018 ** object when the iVersion value is increased. Note that the structure 1019 ** of the sqlite3_vfs object changes in the transaction between 1020 ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 1021 ** modified. 1022 ** 1023 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1024 ** structure used by this VFS. mxPathname is the maximum length of 1025 ** a pathname in this VFS. 1026 ** 1027 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1028 ** the pNext pointer. The [sqlite3_vfs_register()] 1029 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1030 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1031 ** searches the list. Neither the application code nor the VFS 1032 ** implementation should use the pNext pointer. 1033 ** 1034 ** The pNext field is the only field in the sqlite3_vfs 1035 ** structure that SQLite will ever modify. SQLite will only access 1036 ** or modify this field while holding a particular static mutex. 1037 ** The application should never modify anything within the sqlite3_vfs 1038 ** object once the object has been registered. 1039 ** 1040 ** The zName field holds the name of the VFS module. The name must 1041 ** be unique across all VFS modules. 1042 ** 1043 ** [[sqlite3_vfs.xOpen]] 1044 ** ^SQLite guarantees that the zFilename parameter to xOpen 1045 ** is either a NULL pointer or string obtained 1046 ** from xFullPathname() with an optional suffix added. 1047 ** ^If a suffix is added to the zFilename parameter, it will 1048 ** consist of a single "-" character followed by no more than 1049 ** 11 alphanumeric and/or "-" characters. 1050 ** ^SQLite further guarantees that 1051 ** the string will be valid and unchanged until xClose() is 1052 ** called. Because of the previous sentence, 1053 ** the [sqlite3_file] can safely store a pointer to the 1054 ** filename if it needs to remember the filename for some reason. 1055 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1056 ** must invent its own temporary name for the file. ^Whenever the 1057 ** xFilename parameter is NULL it will also be the case that the 1058 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1059 ** 1060 ** The flags argument to xOpen() includes all bits set in 1061 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1062 ** or [sqlite3_open16()] is used, then flags includes at least 1063 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1064 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1065 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1066 ** 1067 ** ^(SQLite will also add one of the following flags to the xOpen() 1068 ** call, depending on the object being opened: 1069 ** 1070 ** <ul> 1071 ** <li> [SQLITE_OPEN_MAIN_DB] 1072 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1073 ** <li> [SQLITE_OPEN_TEMP_DB] 1074 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1075 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1076 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1077 ** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1078 ** <li> [SQLITE_OPEN_WAL] 1079 ** </ul>)^ 1080 ** 1081 ** The file I/O implementation can use the object type flags to 1082 ** change the way it deals with files. For example, an application 1083 ** that does not care about crash recovery or rollback might make 1084 ** the open of a journal file a no-op. Writes to this journal would 1085 ** also be no-ops, and any attempt to read the journal would return 1086 ** SQLITE_IOERR. Or the implementation might recognize that a database 1087 ** file will be doing page-aligned sector reads and writes in a random 1088 ** order and set up its I/O subsystem accordingly. 1089 ** 1090 ** SQLite might also add one of the following flags to the xOpen method: 1091 ** 1092 ** <ul> 1093 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1094 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1095 ** </ul> 1096 ** 1097 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1098 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1099 ** will be set for TEMP databases and their journals, transient 1100 ** databases, and subjournals. 1101 ** 1102 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1103 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1104 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1105 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1106 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1107 ** be created, and that it is an error if it already exists. 1108 ** It is <i>not</i> used to indicate the file should be opened 1109 ** for exclusive access. 1110 ** 1111 ** ^At least szOsFile bytes of memory are allocated by SQLite 1112 ** to hold the [sqlite3_file] structure passed as the third 1113 ** argument to xOpen. The xOpen method does not have to 1114 ** allocate the structure; it should just fill it in. Note that 1115 ** the xOpen method must set the sqlite3_file.pMethods to either 1116 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1117 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1118 ** element will be valid after xOpen returns regardless of the success 1119 ** or failure of the xOpen call. 1120 ** 1121 ** [[sqlite3_vfs.xAccess]] 1122 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1123 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1124 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1125 ** to test whether a file is at least readable. The file can be a 1126 ** directory. 1127 ** 1128 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1129 ** output buffer xFullPathname. The exact size of the output buffer 1130 ** is also passed as a parameter to both methods. If the output buffer 1131 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1132 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1133 ** to prevent this by setting mxPathname to a sufficiently large value. 1134 ** 1135 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1136 ** interfaces are not strictly a part of the filesystem, but they are 1137 ** included in the VFS structure for completeness. 1138 ** The xRandomness() function attempts to return nBytes bytes 1139 ** of good-quality randomness into zOut. The return value is 1140 ** the actual number of bytes of randomness obtained. 1141 ** The xSleep() method causes the calling thread to sleep for at 1142 ** least the number of microseconds given. ^The xCurrentTime() 1143 ** method returns a Julian Day Number for the current date and time as 1144 ** a floating point value. 1145 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1146 ** Day Number multiplied by 86400000 (the number of milliseconds in 1147 ** a 24-hour day). 1148 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1149 ** date and time if that method is available (if iVersion is 2 or 1150 ** greater and the function pointer is not NULL) and will fall back 1151 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1152 ** 1153 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1154 ** are not used by the SQLite core. These optional interfaces are provided 1155 ** by some VFSes to facilitate testing of the VFS code. By overriding 1156 ** system calls with functions under its control, a test program can 1157 ** simulate faults and error conditions that would otherwise be difficult 1158 ** or impossible to induce. The set of system calls that can be overridden 1159 ** varies from one VFS to another, and from one version of the same VFS to the 1160 ** next. Applications that use these interfaces must be prepared for any 1161 ** or all of these interfaces to be NULL or for their behavior to change 1162 ** from one release to the next. Applications must not attempt to access 1163 ** any of these methods if the iVersion of the VFS is less than 3. 1164 */ 1165 typedef struct sqlite3_vfs sqlite3_vfs; 1166 typedef void (*sqlite3_syscall_ptr)(void); 1167 struct sqlite3_vfs { 1168 int iVersion; /* Structure version number (currently 3) */ 1169 int szOsFile; /* Size of subclassed sqlite3_file */ 1170 int mxPathname; /* Maximum file pathname length */ 1171 sqlite3_vfs *pNext; /* Next registered VFS */ 1172 const char *zName; /* Name of this virtual file system */ 1173 void *pAppData; /* Pointer to application-specific data */ 1174 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1175 int flags, int *pOutFlags); 1176 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1177 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1178 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1179 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1180 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1181 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1182 void (*xDlClose)(sqlite3_vfs*, void*); 1183 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1184 int (*xSleep)(sqlite3_vfs*, int microseconds); 1185 int (*xCurrentTime)(sqlite3_vfs*, double*); 1186 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1187 /* 1188 ** The methods above are in version 1 of the sqlite_vfs object 1189 ** definition. Those that follow are added in version 2 or later 1190 */ 1191 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1192 /* 1193 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1194 ** Those below are for version 3 and greater. 1195 */ 1196 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1197 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1198 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1199 /* 1200 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1201 ** New fields may be appended in figure versions. The iVersion 1202 ** value will increment whenever this happens. 1203 */ 1204 }; 1205 1206 /* 1207 ** CAPI3REF: Flags for the xAccess VFS method 1208 ** 1209 ** These integer constants can be used as the third parameter to 1210 ** the xAccess method of an [sqlite3_vfs] object. They determine 1211 ** what kind of permissions the xAccess method is looking for. 1212 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1213 ** simply checks whether the file exists. 1214 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1215 ** checks whether the named directory is both readable and writable 1216 ** (in other words, if files can be added, removed, and renamed within 1217 ** the directory). 1218 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1219 ** [temp_store_directory pragma], though this could change in a future 1220 ** release of SQLite. 1221 ** With SQLITE_ACCESS_READ, the xAccess method 1222 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1223 ** currently unused, though it might be used in a future release of 1224 ** SQLite. 1225 */ 1226 #define SQLITE_ACCESS_EXISTS 0 1227 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1228 #define SQLITE_ACCESS_READ 2 /* Unused */ 1229 1230 /* 1231 ** CAPI3REF: Flags for the xShmLock VFS method 1232 ** 1233 ** These integer constants define the various locking operations 1234 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1235 ** following are the only legal combinations of flags to the 1236 ** xShmLock method: 1237 ** 1238 ** <ul> 1239 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1240 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1241 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1242 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1243 ** </ul> 1244 ** 1245 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1246 ** was given on the corresponding lock. 1247 ** 1248 ** The xShmLock method can transition between unlocked and SHARED or 1249 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1250 ** and EXCLUSIVE. 1251 */ 1252 #define SQLITE_SHM_UNLOCK 1 1253 #define SQLITE_SHM_LOCK 2 1254 #define SQLITE_SHM_SHARED 4 1255 #define SQLITE_SHM_EXCLUSIVE 8 1256 1257 /* 1258 ** CAPI3REF: Maximum xShmLock index 1259 ** 1260 ** The xShmLock method on [sqlite3_io_methods] may use values 1261 ** between 0 and this upper bound as its "offset" argument. 1262 ** The SQLite core will never attempt to acquire or release a 1263 ** lock outside of this range 1264 */ 1265 #define SQLITE_SHM_NLOCK 8 1266 1267 1268 /* 1269 ** CAPI3REF: Initialize The SQLite Library 1270 ** 1271 ** ^The sqlite3_initialize() routine initializes the 1272 ** SQLite library. ^The sqlite3_shutdown() routine 1273 ** deallocates any resources that were allocated by sqlite3_initialize(). 1274 ** These routines are designed to aid in process initialization and 1275 ** shutdown on embedded systems. Workstation applications using 1276 ** SQLite normally do not need to invoke either of these routines. 1277 ** 1278 ** A call to sqlite3_initialize() is an "effective" call if it is 1279 ** the first time sqlite3_initialize() is invoked during the lifetime of 1280 ** the process, or if it is the first time sqlite3_initialize() is invoked 1281 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1282 ** of sqlite3_initialize() does any initialization. All other calls 1283 ** are harmless no-ops.)^ 1284 ** 1285 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1286 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1287 ** an effective call to sqlite3_shutdown() does any deinitialization. 1288 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1289 ** 1290 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1291 ** is not. The sqlite3_shutdown() interface must only be called from a 1292 ** single thread. All open [database connections] must be closed and all 1293 ** other SQLite resources must be deallocated prior to invoking 1294 ** sqlite3_shutdown(). 1295 ** 1296 ** Among other things, ^sqlite3_initialize() will invoke 1297 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1298 ** will invoke sqlite3_os_end(). 1299 ** 1300 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1301 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1302 ** the library (perhaps it is unable to allocate a needed resource such 1303 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1304 ** 1305 ** ^The sqlite3_initialize() routine is called internally by many other 1306 ** SQLite interfaces so that an application usually does not need to 1307 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1308 ** calls sqlite3_initialize() so the SQLite library will be automatically 1309 ** initialized when [sqlite3_open()] is called if it has not be initialized 1310 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1311 ** compile-time option, then the automatic calls to sqlite3_initialize() 1312 ** are omitted and the application must call sqlite3_initialize() directly 1313 ** prior to using any other SQLite interface. For maximum portability, 1314 ** it is recommended that applications always invoke sqlite3_initialize() 1315 ** directly prior to using any other SQLite interface. Future releases 1316 ** of SQLite may require this. In other words, the behavior exhibited 1317 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1318 ** default behavior in some future release of SQLite. 1319 ** 1320 ** The sqlite3_os_init() routine does operating-system specific 1321 ** initialization of the SQLite library. The sqlite3_os_end() 1322 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1323 ** performed by these routines include allocation or deallocation 1324 ** of static resources, initialization of global variables, 1325 ** setting up a default [sqlite3_vfs] module, or setting up 1326 ** a default configuration using [sqlite3_config()]. 1327 ** 1328 ** The application should never invoke either sqlite3_os_init() 1329 ** or sqlite3_os_end() directly. The application should only invoke 1330 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1331 ** interface is called automatically by sqlite3_initialize() and 1332 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1333 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1334 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1335 ** When [custom builds | built for other platforms] 1336 ** (using the [SQLITE_OS_OTHER=1] compile-time 1337 ** option) the application must supply a suitable implementation for 1338 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1339 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1340 ** must return [SQLITE_OK] on success and some other [error code] upon 1341 ** failure. 1342 */ 1343 SQLITE_API int SQLITE_STDCALL sqlite3_initialize(void); 1344 SQLITE_API int SQLITE_STDCALL sqlite3_shutdown(void); 1345 SQLITE_API int SQLITE_STDCALL sqlite3_os_init(void); 1346 SQLITE_API int SQLITE_STDCALL sqlite3_os_end(void); 1347 1348 /* 1349 ** CAPI3REF: Configuring The SQLite Library 1350 ** 1351 ** The sqlite3_config() interface is used to make global configuration 1352 ** changes to SQLite in order to tune SQLite to the specific needs of 1353 ** the application. The default configuration is recommended for most 1354 ** applications and so this routine is usually not necessary. It is 1355 ** provided to support rare applications with unusual needs. 1356 ** 1357 ** The sqlite3_config() interface is not threadsafe. The application 1358 ** must insure that no other SQLite interfaces are invoked by other 1359 ** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 1360 ** may only be invoked prior to library initialization using 1361 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1362 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1363 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1364 ** Note, however, that ^sqlite3_config() can be called as part of the 1365 ** implementation of an application-defined [sqlite3_os_init()]. 1366 ** 1367 ** The first argument to sqlite3_config() is an integer 1368 ** [configuration option] that determines 1369 ** what property of SQLite is to be configured. Subsequent arguments 1370 ** vary depending on the [configuration option] 1371 ** in the first argument. 1372 ** 1373 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1374 ** ^If the option is unknown or SQLite is unable to set the option 1375 ** then this routine returns a non-zero [error code]. 1376 */ 1377 SQLITE_API int SQLITE_CDECL sqlite3_config(int, ...); 1378 1379 /* 1380 ** CAPI3REF: Configure database connections 1381 ** 1382 ** The sqlite3_db_config() interface is used to make configuration 1383 ** changes to a [database connection]. The interface is similar to 1384 ** [sqlite3_config()] except that the changes apply to a single 1385 ** [database connection] (specified in the first argument). 1386 ** 1387 ** The second argument to sqlite3_db_config(D,V,...) is the 1388 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1389 ** that indicates what aspect of the [database connection] is being configured. 1390 ** Subsequent arguments vary depending on the configuration verb. 1391 ** 1392 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1393 ** the call is considered successful. 1394 */ 1395 SQLITE_API int SQLITE_CDECL sqlite3_db_config(sqlite3*, int op, ...); 1396 1397 /* 1398 ** CAPI3REF: Memory Allocation Routines 1399 ** 1400 ** An instance of this object defines the interface between SQLite 1401 ** and low-level memory allocation routines. 1402 ** 1403 ** This object is used in only one place in the SQLite interface. 1404 ** A pointer to an instance of this object is the argument to 1405 ** [sqlite3_config()] when the configuration option is 1406 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1407 ** By creating an instance of this object 1408 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1409 ** during configuration, an application can specify an alternative 1410 ** memory allocation subsystem for SQLite to use for all of its 1411 ** dynamic memory needs. 1412 ** 1413 ** Note that SQLite comes with several [built-in memory allocators] 1414 ** that are perfectly adequate for the overwhelming majority of applications 1415 ** and that this object is only useful to a tiny minority of applications 1416 ** with specialized memory allocation requirements. This object is 1417 ** also used during testing of SQLite in order to specify an alternative 1418 ** memory allocator that simulates memory out-of-memory conditions in 1419 ** order to verify that SQLite recovers gracefully from such 1420 ** conditions. 1421 ** 1422 ** The xMalloc, xRealloc, and xFree methods must work like the 1423 ** malloc(), realloc() and free() functions from the standard C library. 1424 ** ^SQLite guarantees that the second argument to 1425 ** xRealloc is always a value returned by a prior call to xRoundup. 1426 ** 1427 ** xSize should return the allocated size of a memory allocation 1428 ** previously obtained from xMalloc or xRealloc. The allocated size 1429 ** is always at least as big as the requested size but may be larger. 1430 ** 1431 ** The xRoundup method returns what would be the allocated size of 1432 ** a memory allocation given a particular requested size. Most memory 1433 ** allocators round up memory allocations at least to the next multiple 1434 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1435 ** Every memory allocation request coming in through [sqlite3_malloc()] 1436 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1437 ** that causes the corresponding memory allocation to fail. 1438 ** 1439 ** The xInit method initializes the memory allocator. For example, 1440 ** it might allocate any require mutexes or initialize internal data 1441 ** structures. The xShutdown method is invoked (indirectly) by 1442 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1443 ** by xInit. The pAppData pointer is used as the only parameter to 1444 ** xInit and xShutdown. 1445 ** 1446 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1447 ** the xInit method, so the xInit method need not be threadsafe. The 1448 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1449 ** not need to be threadsafe either. For all other methods, SQLite 1450 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1451 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1452 ** it is by default) and so the methods are automatically serialized. 1453 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1454 ** methods must be threadsafe or else make their own arrangements for 1455 ** serialization. 1456 ** 1457 ** SQLite will never invoke xInit() more than once without an intervening 1458 ** call to xShutdown(). 1459 */ 1460 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1461 struct sqlite3_mem_methods { 1462 void *(*xMalloc)(int); /* Memory allocation function */ 1463 void (*xFree)(void*); /* Free a prior allocation */ 1464 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1465 int (*xSize)(void*); /* Return the size of an allocation */ 1466 int (*xRoundup)(int); /* Round up request size to allocation size */ 1467 int (*xInit)(void*); /* Initialize the memory allocator */ 1468 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1469 void *pAppData; /* Argument to xInit() and xShutdown() */ 1470 }; 1471 1472 /* 1473 ** CAPI3REF: Configuration Options 1474 ** KEYWORDS: {configuration option} 1475 ** 1476 ** These constants are the available integer configuration options that 1477 ** can be passed as the first argument to the [sqlite3_config()] interface. 1478 ** 1479 ** New configuration options may be added in future releases of SQLite. 1480 ** Existing configuration options might be discontinued. Applications 1481 ** should check the return code from [sqlite3_config()] to make sure that 1482 ** the call worked. The [sqlite3_config()] interface will return a 1483 ** non-zero [error code] if a discontinued or unsupported configuration option 1484 ** is invoked. 1485 ** 1486 ** <dl> 1487 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1488 ** <dd>There are no arguments to this option. ^This option sets the 1489 ** [threading mode] to Single-thread. In other words, it disables 1490 ** all mutexing and puts SQLite into a mode where it can only be used 1491 ** by a single thread. ^If SQLite is compiled with 1492 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1493 ** it is not possible to change the [threading mode] from its default 1494 ** value of Single-thread and so [sqlite3_config()] will return 1495 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1496 ** configuration option.</dd> 1497 ** 1498 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1499 ** <dd>There are no arguments to this option. ^This option sets the 1500 ** [threading mode] to Multi-thread. In other words, it disables 1501 ** mutexing on [database connection] and [prepared statement] objects. 1502 ** The application is responsible for serializing access to 1503 ** [database connections] and [prepared statements]. But other mutexes 1504 ** are enabled so that SQLite will be safe to use in a multi-threaded 1505 ** environment as long as no two threads attempt to use the same 1506 ** [database connection] at the same time. ^If SQLite is compiled with 1507 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1508 ** it is not possible to set the Multi-thread [threading mode] and 1509 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1510 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1511 ** 1512 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1513 ** <dd>There are no arguments to this option. ^This option sets the 1514 ** [threading mode] to Serialized. In other words, this option enables 1515 ** all mutexes including the recursive 1516 ** mutexes on [database connection] and [prepared statement] objects. 1517 ** In this mode (which is the default when SQLite is compiled with 1518 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1519 ** to [database connections] and [prepared statements] so that the 1520 ** application is free to use the same [database connection] or the 1521 ** same [prepared statement] in different threads at the same time. 1522 ** ^If SQLite is compiled with 1523 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1524 ** it is not possible to set the Serialized [threading mode] and 1525 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1526 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1527 ** 1528 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1529 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1530 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1531 ** The argument specifies 1532 ** alternative low-level memory allocation routines to be used in place of 1533 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1534 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1535 ** before the [sqlite3_config()] call returns.</dd> 1536 ** 1537 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1538 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1539 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1540 ** The [sqlite3_mem_methods] 1541 ** structure is filled with the currently defined memory allocation routines.)^ 1542 ** This option can be used to overload the default memory allocation 1543 ** routines with a wrapper that simulations memory allocation failure or 1544 ** tracks memory usage, for example. </dd> 1545 ** 1546 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1547 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1548 ** interpreted as a boolean, which enables or disables the collection of 1549 ** memory allocation statistics. ^(When memory allocation statistics are 1550 ** disabled, the following SQLite interfaces become non-operational: 1551 ** <ul> 1552 ** <li> [sqlite3_memory_used()] 1553 ** <li> [sqlite3_memory_highwater()] 1554 ** <li> [sqlite3_soft_heap_limit64()] 1555 ** <li> [sqlite3_status64()] 1556 ** </ul>)^ 1557 ** ^Memory allocation statistics are enabled by default unless SQLite is 1558 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1559 ** allocation statistics are disabled by default. 1560 ** </dd> 1561 ** 1562 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1563 ** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer 1564 ** that SQLite can use for scratch memory. ^(There are three arguments 1565 ** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte 1566 ** aligned memory buffer from which the scratch allocations will be 1567 ** drawn, the size of each scratch allocation (sz), 1568 ** and the maximum number of scratch allocations (N).)^ 1569 ** The first argument must be a pointer to an 8-byte aligned buffer 1570 ** of at least sz*N bytes of memory. 1571 ** ^SQLite will not use more than one scratch buffers per thread. 1572 ** ^SQLite will never request a scratch buffer that is more than 6 1573 ** times the database page size. 1574 ** ^If SQLite needs needs additional 1575 ** scratch memory beyond what is provided by this configuration option, then 1576 ** [sqlite3_malloc()] will be used to obtain the memory needed.<p> 1577 ** ^When the application provides any amount of scratch memory using 1578 ** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large 1579 ** [sqlite3_malloc|heap allocations]. 1580 ** This can help [Robson proof|prevent memory allocation failures] due to heap 1581 ** fragmentation in low-memory embedded systems. 1582 ** </dd> 1583 ** 1584 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1585 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a static memory buffer 1586 ** that SQLite can use for the database page cache with the default page 1587 ** cache implementation. 1588 ** This configuration should not be used if an application-define page 1589 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2] 1590 ** configuration option. 1591 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1592 ** 8-byte aligned 1593 ** memory, the size of each page buffer (sz), and the number of pages (N). 1594 ** The sz argument should be the size of the largest database page 1595 ** (a power of two between 512 and 65536) plus some extra bytes for each 1596 ** page header. ^The number of extra bytes needed by the page header 1597 ** can be determined using the [SQLITE_CONFIG_PCACHE_HDRSZ] option 1598 ** to [sqlite3_config()]. 1599 ** ^It is harmless, apart from the wasted memory, 1600 ** for the sz parameter to be larger than necessary. The first 1601 ** argument should pointer to an 8-byte aligned block of memory that 1602 ** is at least sz*N bytes of memory, otherwise subsequent behavior is 1603 ** undefined. 1604 ** ^SQLite will use the memory provided by the first argument to satisfy its 1605 ** memory needs for the first N pages that it adds to cache. ^If additional 1606 ** page cache memory is needed beyond what is provided by this option, then 1607 ** SQLite goes to [sqlite3_malloc()] for the additional storage space.</dd> 1608 ** 1609 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1610 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1611 ** that SQLite will use for all of its dynamic memory allocation needs 1612 ** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and 1613 ** [SQLITE_CONFIG_PAGECACHE]. 1614 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1615 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1616 ** [SQLITE_ERROR] if invoked otherwise. 1617 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1618 ** An 8-byte aligned pointer to the memory, 1619 ** the number of bytes in the memory buffer, and the minimum allocation size. 1620 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1621 ** to using its default memory allocator (the system malloc() implementation), 1622 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1623 ** memory pointer is not NULL then the alternative memory 1624 ** allocator is engaged to handle all of SQLites memory allocation needs. 1625 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1626 ** boundary or subsequent behavior of SQLite will be undefined. 1627 ** The minimum allocation size is capped at 2**12. Reasonable values 1628 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1629 ** 1630 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1631 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1632 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1633 ** The argument specifies alternative low-level mutex routines to be used 1634 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1635 ** the content of the [sqlite3_mutex_methods] structure before the call to 1636 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1637 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1638 ** the entire mutexing subsystem is omitted from the build and hence calls to 1639 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1640 ** return [SQLITE_ERROR].</dd> 1641 ** 1642 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1643 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1644 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1645 ** [sqlite3_mutex_methods] 1646 ** structure is filled with the currently defined mutex routines.)^ 1647 ** This option can be used to overload the default mutex allocation 1648 ** routines with a wrapper used to track mutex usage for performance 1649 ** profiling or testing, for example. ^If SQLite is compiled with 1650 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1651 ** the entire mutexing subsystem is omitted from the build and hence calls to 1652 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1653 ** return [SQLITE_ERROR].</dd> 1654 ** 1655 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1656 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1657 ** the default size of lookaside memory on each [database connection]. 1658 ** The first argument is the 1659 ** size of each lookaside buffer slot and the second is the number of 1660 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1661 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1662 ** option to [sqlite3_db_config()] can be used to change the lookaside 1663 ** configuration on individual connections.)^ </dd> 1664 ** 1665 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1666 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1667 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1668 ** the interface to a custom page cache implementation.)^ 1669 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1670 ** 1671 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1672 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1673 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1674 ** the current page cache implementation into that object.)^ </dd> 1675 ** 1676 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1677 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1678 ** global [error log]. 1679 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1680 ** function with a call signature of void(*)(void*,int,const char*), 1681 ** and a pointer to void. ^If the function pointer is not NULL, it is 1682 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1683 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1684 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1685 ** passed through as the first parameter to the application-defined logger 1686 ** function whenever that function is invoked. ^The second parameter to 1687 ** the logger function is a copy of the first parameter to the corresponding 1688 ** [sqlite3_log()] call and is intended to be a [result code] or an 1689 ** [extended result code]. ^The third parameter passed to the logger is 1690 ** log message after formatting via [sqlite3_snprintf()]. 1691 ** The SQLite logging interface is not reentrant; the logger function 1692 ** supplied by the application must not invoke any SQLite interface. 1693 ** In a multi-threaded application, the application-defined logger 1694 ** function must be threadsafe. </dd> 1695 ** 1696 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1697 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1698 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1699 ** then URI handling is globally disabled.)^ ^If URI handling is globally 1700 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1701 ** [sqlite3_open16()] or 1702 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1703 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1704 ** connection is opened. ^If it is globally disabled, filenames are 1705 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1706 ** database connection is opened. ^(By default, URI handling is globally 1707 ** disabled. The default value may be changed by compiling with the 1708 ** [SQLITE_USE_URI] symbol defined.)^ 1709 ** 1710 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1711 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1712 ** argument which is interpreted as a boolean in order to enable or disable 1713 ** the use of covering indices for full table scans in the query optimizer. 1714 ** ^The default setting is determined 1715 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1716 ** if that compile-time option is omitted. 1717 ** The ability to disable the use of covering indices for full table scans 1718 ** is because some incorrectly coded legacy applications might malfunction 1719 ** when the optimization is enabled. Providing the ability to 1720 ** disable the optimization allows the older, buggy application code to work 1721 ** without change even with newer versions of SQLite. 1722 ** 1723 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1724 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1725 ** <dd> These options are obsolete and should not be used by new code. 1726 ** They are retained for backwards compatibility but are now no-ops. 1727 ** </dd> 1728 ** 1729 ** [[SQLITE_CONFIG_SQLLOG]] 1730 ** <dt>SQLITE_CONFIG_SQLLOG 1731 ** <dd>This option is only available if sqlite is compiled with the 1732 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1733 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1734 ** The second should be of type (void*). The callback is invoked by the library 1735 ** in three separate circumstances, identified by the value passed as the 1736 ** fourth parameter. If the fourth parameter is 0, then the database connection 1737 ** passed as the second argument has just been opened. The third argument 1738 ** points to a buffer containing the name of the main database file. If the 1739 ** fourth parameter is 1, then the SQL statement that the third parameter 1740 ** points to has just been executed. Or, if the fourth parameter is 2, then 1741 ** the connection being passed as the second parameter is being closed. The 1742 ** third parameter is passed NULL In this case. An example of using this 1743 ** configuration option can be seen in the "test_sqllog.c" source file in 1744 ** the canonical SQLite source tree.</dd> 1745 ** 1746 ** [[SQLITE_CONFIG_MMAP_SIZE]] 1747 ** <dt>SQLITE_CONFIG_MMAP_SIZE 1748 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1749 ** that are the default mmap size limit (the default setting for 1750 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1751 ** ^The default setting can be overridden by each database connection using 1752 ** either the [PRAGMA mmap_size] command, or by using the 1753 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1754 ** will be silently truncated if necessary so that it does not exceed the 1755 ** compile-time maximum mmap size set by the 1756 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1757 ** ^If either argument to this option is negative, then that argument is 1758 ** changed to its compile-time default. 1759 ** 1760 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1761 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1762 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1763 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1764 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1765 ** that specifies the maximum size of the created heap. 1766 ** 1767 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1768 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1769 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1770 ** is a pointer to an integer and writes into that integer the number of extra 1771 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1772 ** The amount of extra space required can change depending on the compiler, 1773 ** target platform, and SQLite version. 1774 ** 1775 ** [[SQLITE_CONFIG_PMASZ]] 1776 ** <dt>SQLITE_CONFIG_PMASZ 1777 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1778 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1779 ** sorter to that integer. The default minimum PMA Size is set by the 1780 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1781 ** to help with sort operations when multithreaded sorting 1782 ** is enabled (using the [PRAGMA threads] command) and the amount of content 1783 ** to be sorted exceeds the page size times the minimum of the 1784 ** [PRAGMA cache_size] setting and this value. 1785 ** </dl> 1786 */ 1787 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1788 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1789 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1790 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1791 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1792 #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1793 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1794 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1795 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1796 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1797 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1798 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1799 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1800 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1801 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1802 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1803 #define SQLITE_CONFIG_URI 17 /* int */ 1804 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1805 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1806 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1807 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1808 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1809 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1810 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 1811 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 1812 1813 /* 1814 ** CAPI3REF: Database Connection Configuration Options 1815 ** 1816 ** These constants are the available integer configuration options that 1817 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 1818 ** 1819 ** New configuration options may be added in future releases of SQLite. 1820 ** Existing configuration options might be discontinued. Applications 1821 ** should check the return code from [sqlite3_db_config()] to make sure that 1822 ** the call worked. ^The [sqlite3_db_config()] interface will return a 1823 ** non-zero [error code] if a discontinued or unsupported configuration option 1824 ** is invoked. 1825 ** 1826 ** <dl> 1827 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1828 ** <dd> ^This option takes three additional arguments that determine the 1829 ** [lookaside memory allocator] configuration for the [database connection]. 1830 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1831 ** pointer to a memory buffer to use for lookaside memory. 1832 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1833 ** may be NULL in which case SQLite will allocate the 1834 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1835 ** size of each lookaside buffer slot. ^The third argument is the number of 1836 ** slots. The size of the buffer in the first argument must be greater than 1837 ** or equal to the product of the second and third arguments. The buffer 1838 ** must be aligned to an 8-byte boundary. ^If the second argument to 1839 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1840 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1841 ** configuration for a database connection can only be changed when that 1842 ** connection is not currently using lookaside memory, or in other words 1843 ** when the "current value" returned by 1844 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1845 ** Any attempt to change the lookaside memory configuration when lookaside 1846 ** memory is in use leaves the configuration unchanged and returns 1847 ** [SQLITE_BUSY].)^</dd> 1848 ** 1849 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1850 ** <dd> ^This option is used to enable or disable the enforcement of 1851 ** [foreign key constraints]. There should be two additional arguments. 1852 ** The first argument is an integer which is 0 to disable FK enforcement, 1853 ** positive to enable FK enforcement or negative to leave FK enforcement 1854 ** unchanged. The second parameter is a pointer to an integer into which 1855 ** is written 0 or 1 to indicate whether FK enforcement is off or on 1856 ** following this call. The second parameter may be a NULL pointer, in 1857 ** which case the FK enforcement setting is not reported back. </dd> 1858 ** 1859 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1860 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1861 ** There should be two additional arguments. 1862 ** The first argument is an integer which is 0 to disable triggers, 1863 ** positive to enable triggers or negative to leave the setting unchanged. 1864 ** The second parameter is a pointer to an integer into which 1865 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 1866 ** following this call. The second parameter may be a NULL pointer, in 1867 ** which case the trigger setting is not reported back. </dd> 1868 ** 1869 ** </dl> 1870 */ 1871 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1872 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1873 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1874 1875 1876 /* 1877 ** CAPI3REF: Enable Or Disable Extended Result Codes 1878 ** 1879 ** ^The sqlite3_extended_result_codes() routine enables or disables the 1880 ** [extended result codes] feature of SQLite. ^The extended result 1881 ** codes are disabled by default for historical compatibility. 1882 */ 1883 SQLITE_API int SQLITE_STDCALL sqlite3_extended_result_codes(sqlite3*, int onoff); 1884 1885 /* 1886 ** CAPI3REF: Last Insert Rowid 1887 ** 1888 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 1889 ** has a unique 64-bit signed 1890 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1891 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1892 ** names are not also used by explicitly declared columns. ^If 1893 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 1894 ** is another alias for the rowid. 1895 ** 1896 ** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 1897 ** most recent successful [INSERT] into a rowid table or [virtual table] 1898 ** on database connection D. 1899 ** ^Inserts into [WITHOUT ROWID] tables are not recorded. 1900 ** ^If no successful [INSERT]s into rowid tables 1901 ** have ever occurred on the database connection D, 1902 ** then sqlite3_last_insert_rowid(D) returns zero. 1903 ** 1904 ** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 1905 ** method, then this routine will return the [rowid] of the inserted 1906 ** row as long as the trigger or virtual table method is running. 1907 ** But once the trigger or virtual table method ends, the value returned 1908 ** by this routine reverts to what it was before the trigger or virtual 1909 ** table method began.)^ 1910 ** 1911 ** ^An [INSERT] that fails due to a constraint violation is not a 1912 ** successful [INSERT] and does not change the value returned by this 1913 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1914 ** and INSERT OR ABORT make no changes to the return value of this 1915 ** routine when their insertion fails. ^(When INSERT OR REPLACE 1916 ** encounters a constraint violation, it does not fail. The 1917 ** INSERT continues to completion after deleting rows that caused 1918 ** the constraint problem so INSERT OR REPLACE will always change 1919 ** the return value of this interface.)^ 1920 ** 1921 ** ^For the purposes of this routine, an [INSERT] is considered to 1922 ** be successful even if it is subsequently rolled back. 1923 ** 1924 ** This function is accessible to SQL statements via the 1925 ** [last_insert_rowid() SQL function]. 1926 ** 1927 ** If a separate thread performs a new [INSERT] on the same 1928 ** database connection while the [sqlite3_last_insert_rowid()] 1929 ** function is running and thus changes the last insert [rowid], 1930 ** then the value returned by [sqlite3_last_insert_rowid()] is 1931 ** unpredictable and might not equal either the old or the new 1932 ** last insert [rowid]. 1933 */ 1934 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_last_insert_rowid(sqlite3*); 1935 1936 /* 1937 ** CAPI3REF: Count The Number Of Rows Modified 1938 ** 1939 ** ^This function returns the number of rows modified, inserted or 1940 ** deleted by the most recently completed INSERT, UPDATE or DELETE 1941 ** statement on the database connection specified by the only parameter. 1942 ** ^Executing any other type of SQL statement does not modify the value 1943 ** returned by this function. 1944 ** 1945 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 1946 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 1947 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 1948 ** 1949 ** Changes to a view that are intercepted by 1950 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 1951 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 1952 ** DELETE statement run on a view is always zero. Only changes made to real 1953 ** tables are counted. 1954 ** 1955 ** Things are more complicated if the sqlite3_changes() function is 1956 ** executed while a trigger program is running. This may happen if the 1957 ** program uses the [changes() SQL function], or if some other callback 1958 ** function invokes sqlite3_changes() directly. Essentially: 1959 ** 1960 ** <ul> 1961 ** <li> ^(Before entering a trigger program the value returned by 1962 ** sqlite3_changes() function is saved. After the trigger program 1963 ** has finished, the original value is restored.)^ 1964 ** 1965 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 1966 ** statement sets the value returned by sqlite3_changes() 1967 ** upon completion as normal. Of course, this value will not include 1968 ** any changes performed by sub-triggers, as the sqlite3_changes() 1969 ** value will be saved and restored after each sub-trigger has run.)^ 1970 ** </ul> 1971 ** 1972 ** ^This means that if the changes() SQL function (or similar) is used 1973 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 1974 ** returns the value as set when the calling statement began executing. 1975 ** ^If it is used by the second or subsequent such statement within a trigger 1976 ** program, the value returned reflects the number of rows modified by the 1977 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 1978 ** 1979 ** See also the [sqlite3_total_changes()] interface, the 1980 ** [count_changes pragma], and the [changes() SQL function]. 1981 ** 1982 ** If a separate thread makes changes on the same database connection 1983 ** while [sqlite3_changes()] is running then the value returned 1984 ** is unpredictable and not meaningful. 1985 */ 1986 SQLITE_API int SQLITE_STDCALL sqlite3_changes(sqlite3*); 1987 1988 /* 1989 ** CAPI3REF: Total Number Of Rows Modified 1990 ** 1991 ** ^This function returns the total number of rows inserted, modified or 1992 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 1993 ** since the database connection was opened, including those executed as 1994 ** part of trigger programs. ^Executing any other type of SQL statement 1995 ** does not affect the value returned by sqlite3_total_changes(). 1996 ** 1997 ** ^Changes made as part of [foreign key actions] are included in the 1998 ** count, but those made as part of REPLACE constraint resolution are 1999 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2000 ** are not counted. 2001 ** 2002 ** See also the [sqlite3_changes()] interface, the 2003 ** [count_changes pragma], and the [total_changes() SQL function]. 2004 ** 2005 ** If a separate thread makes changes on the same database connection 2006 ** while [sqlite3_total_changes()] is running then the value 2007 ** returned is unpredictable and not meaningful. 2008 */ 2009 SQLITE_API int SQLITE_STDCALL sqlite3_total_changes(sqlite3*); 2010 2011 /* 2012 ** CAPI3REF: Interrupt A Long-Running Query 2013 ** 2014 ** ^This function causes any pending database operation to abort and 2015 ** return at its earliest opportunity. This routine is typically 2016 ** called in response to a user action such as pressing "Cancel" 2017 ** or Ctrl-C where the user wants a long query operation to halt 2018 ** immediately. 2019 ** 2020 ** ^It is safe to call this routine from a thread different from the 2021 ** thread that is currently running the database operation. But it 2022 ** is not safe to call this routine with a [database connection] that 2023 ** is closed or might close before sqlite3_interrupt() returns. 2024 ** 2025 ** ^If an SQL operation is very nearly finished at the time when 2026 ** sqlite3_interrupt() is called, then it might not have an opportunity 2027 ** to be interrupted and might continue to completion. 2028 ** 2029 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2030 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2031 ** that is inside an explicit transaction, then the entire transaction 2032 ** will be rolled back automatically. 2033 ** 2034 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2035 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2036 ** that are started after the sqlite3_interrupt() call and before the 2037 ** running statements reaches zero are interrupted as if they had been 2038 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2039 ** that are started after the running statement count reaches zero are 2040 ** not effected by the sqlite3_interrupt(). 2041 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2042 ** SQL statements is a no-op and has no effect on SQL statements 2043 ** that are started after the sqlite3_interrupt() call returns. 2044 ** 2045 ** If the database connection closes while [sqlite3_interrupt()] 2046 ** is running then bad things will likely happen. 2047 */ 2048 SQLITE_API void SQLITE_STDCALL sqlite3_interrupt(sqlite3*); 2049 2050 /* 2051 ** CAPI3REF: Determine If An SQL Statement Is Complete 2052 ** 2053 ** These routines are useful during command-line input to determine if the 2054 ** currently entered text seems to form a complete SQL statement or 2055 ** if additional input is needed before sending the text into 2056 ** SQLite for parsing. ^These routines return 1 if the input string 2057 ** appears to be a complete SQL statement. ^A statement is judged to be 2058 ** complete if it ends with a semicolon token and is not a prefix of a 2059 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2060 ** string literals or quoted identifier names or comments are not 2061 ** independent tokens (they are part of the token in which they are 2062 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2063 ** and comments that follow the final semicolon are ignored. 2064 ** 2065 ** ^These routines return 0 if the statement is incomplete. ^If a 2066 ** memory allocation fails, then SQLITE_NOMEM is returned. 2067 ** 2068 ** ^These routines do not parse the SQL statements thus 2069 ** will not detect syntactically incorrect SQL. 2070 ** 2071 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2072 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2073 ** automatically by sqlite3_complete16(). If that initialization fails, 2074 ** then the return value from sqlite3_complete16() will be non-zero 2075 ** regardless of whether or not the input SQL is complete.)^ 2076 ** 2077 ** The input to [sqlite3_complete()] must be a zero-terminated 2078 ** UTF-8 string. 2079 ** 2080 ** The input to [sqlite3_complete16()] must be a zero-terminated 2081 ** UTF-16 string in native byte order. 2082 */ 2083 SQLITE_API int SQLITE_STDCALL sqlite3_complete(const char *sql); 2084 SQLITE_API int SQLITE_STDCALL sqlite3_complete16(const void *sql); 2085 2086 /* 2087 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2088 ** KEYWORDS: {busy-handler callback} {busy handler} 2089 ** 2090 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2091 ** that might be invoked with argument P whenever 2092 ** an attempt is made to access a database table associated with 2093 ** [database connection] D when another thread 2094 ** or process has the table locked. 2095 ** The sqlite3_busy_handler() interface is used to implement 2096 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2097 ** 2098 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2099 ** is returned immediately upon encountering the lock. ^If the busy callback 2100 ** is not NULL, then the callback might be invoked with two arguments. 2101 ** 2102 ** ^The first argument to the busy handler is a copy of the void* pointer which 2103 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2104 ** the busy handler callback is the number of times that the busy handler has 2105 ** been invoked previously for the same locking event. ^If the 2106 ** busy callback returns 0, then no additional attempts are made to 2107 ** access the database and [SQLITE_BUSY] is returned 2108 ** to the application. 2109 ** ^If the callback returns non-zero, then another attempt 2110 ** is made to access the database and the cycle repeats. 2111 ** 2112 ** The presence of a busy handler does not guarantee that it will be invoked 2113 ** when there is lock contention. ^If SQLite determines that invoking the busy 2114 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2115 ** to the application instead of invoking the 2116 ** busy handler. 2117 ** Consider a scenario where one process is holding a read lock that 2118 ** it is trying to promote to a reserved lock and 2119 ** a second process is holding a reserved lock that it is trying 2120 ** to promote to an exclusive lock. The first process cannot proceed 2121 ** because it is blocked by the second and the second process cannot 2122 ** proceed because it is blocked by the first. If both processes 2123 ** invoke the busy handlers, neither will make any progress. Therefore, 2124 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2125 ** will induce the first process to release its read lock and allow 2126 ** the second process to proceed. 2127 ** 2128 ** ^The default busy callback is NULL. 2129 ** 2130 ** ^(There can only be a single busy handler defined for each 2131 ** [database connection]. Setting a new busy handler clears any 2132 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2133 ** or evaluating [PRAGMA busy_timeout=N] will change the 2134 ** busy handler and thus clear any previously set busy handler. 2135 ** 2136 ** The busy callback should not take any actions which modify the 2137 ** database connection that invoked the busy handler. In other words, 2138 ** the busy handler is not reentrant. Any such actions 2139 ** result in undefined behavior. 2140 ** 2141 ** A busy handler must not close the database connection 2142 ** or [prepared statement] that invoked the busy handler. 2143 */ 2144 SQLITE_API int SQLITE_STDCALL sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 2145 2146 /* 2147 ** CAPI3REF: Set A Busy Timeout 2148 ** 2149 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2150 ** for a specified amount of time when a table is locked. ^The handler 2151 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2152 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2153 ** the handler returns 0 which causes [sqlite3_step()] to return 2154 ** [SQLITE_BUSY]. 2155 ** 2156 ** ^Calling this routine with an argument less than or equal to zero 2157 ** turns off all busy handlers. 2158 ** 2159 ** ^(There can only be a single busy handler for a particular 2160 ** [database connection] at any given moment. If another busy handler 2161 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2162 ** this routine, that other busy handler is cleared.)^ 2163 ** 2164 ** See also: [PRAGMA busy_timeout] 2165 */ 2166 SQLITE_API int SQLITE_STDCALL sqlite3_busy_timeout(sqlite3*, int ms); 2167 2168 /* 2169 ** CAPI3REF: Convenience Routines For Running Queries 2170 ** 2171 ** This is a legacy interface that is preserved for backwards compatibility. 2172 ** Use of this interface is not recommended. 2173 ** 2174 ** Definition: A <b>result table</b> is memory data structure created by the 2175 ** [sqlite3_get_table()] interface. A result table records the 2176 ** complete query results from one or more queries. 2177 ** 2178 ** The table conceptually has a number of rows and columns. But 2179 ** these numbers are not part of the result table itself. These 2180 ** numbers are obtained separately. Let N be the number of rows 2181 ** and M be the number of columns. 2182 ** 2183 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2184 ** There are (N+1)*M elements in the array. The first M pointers point 2185 ** to zero-terminated strings that contain the names of the columns. 2186 ** The remaining entries all point to query results. NULL values result 2187 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2188 ** string representation as returned by [sqlite3_column_text()]. 2189 ** 2190 ** A result table might consist of one or more memory allocations. 2191 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2192 ** A result table should be deallocated using [sqlite3_free_table()]. 2193 ** 2194 ** ^(As an example of the result table format, suppose a query result 2195 ** is as follows: 2196 ** 2197 ** <blockquote><pre> 2198 ** Name | Age 2199 ** ----------------------- 2200 ** Alice | 43 2201 ** Bob | 28 2202 ** Cindy | 21 2203 ** </pre></blockquote> 2204 ** 2205 ** There are two column (M==2) and three rows (N==3). Thus the 2206 ** result table has 8 entries. Suppose the result table is stored 2207 ** in an array names azResult. Then azResult holds this content: 2208 ** 2209 ** <blockquote><pre> 2210 ** azResult[0] = "Name"; 2211 ** azResult[1] = "Age"; 2212 ** azResult[2] = "Alice"; 2213 ** azResult[3] = "43"; 2214 ** azResult[4] = "Bob"; 2215 ** azResult[5] = "28"; 2216 ** azResult[6] = "Cindy"; 2217 ** azResult[7] = "21"; 2218 ** </pre></blockquote>)^ 2219 ** 2220 ** ^The sqlite3_get_table() function evaluates one or more 2221 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2222 ** string of its 2nd parameter and returns a result table to the 2223 ** pointer given in its 3rd parameter. 2224 ** 2225 ** After the application has finished with the result from sqlite3_get_table(), 2226 ** it must pass the result table pointer to sqlite3_free_table() in order to 2227 ** release the memory that was malloced. Because of the way the 2228 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2229 ** function must not try to call [sqlite3_free()] directly. Only 2230 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2231 ** 2232 ** The sqlite3_get_table() interface is implemented as a wrapper around 2233 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2234 ** to any internal data structures of SQLite. It uses only the public 2235 ** interface defined here. As a consequence, errors that occur in the 2236 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2237 ** reflected in subsequent calls to [sqlite3_errcode()] or 2238 ** [sqlite3_errmsg()]. 2239 */ 2240 SQLITE_API int SQLITE_STDCALL sqlite3_get_table( 2241 sqlite3 *db, /* An open database */ 2242 const char *zSql, /* SQL to be evaluated */ 2243 char ***pazResult, /* Results of the query */ 2244 int *pnRow, /* Number of result rows written here */ 2245 int *pnColumn, /* Number of result columns written here */ 2246 char **pzErrmsg /* Error msg written here */ 2247 ); 2248 SQLITE_API void SQLITE_STDCALL sqlite3_free_table(char **result); 2249 2250 /* 2251 ** CAPI3REF: Formatted String Printing Functions 2252 ** 2253 ** These routines are work-alikes of the "printf()" family of functions 2254 ** from the standard C library. 2255 ** These routines understand most of the common K&R formatting options, 2256 ** plus some additional non-standard formats, detailed below. 2257 ** Note that some of the more obscure formatting options from recent 2258 ** C-library standards are omitted from this implementation. 2259 ** 2260 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2261 ** results into memory obtained from [sqlite3_malloc()]. 2262 ** The strings returned by these two routines should be 2263 ** released by [sqlite3_free()]. ^Both routines return a 2264 ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2265 ** memory to hold the resulting string. 2266 ** 2267 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2268 ** the standard C library. The result is written into the 2269 ** buffer supplied as the second parameter whose size is given by 2270 ** the first parameter. Note that the order of the 2271 ** first two parameters is reversed from snprintf().)^ This is an 2272 ** historical accident that cannot be fixed without breaking 2273 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2274 ** returns a pointer to its buffer instead of the number of 2275 ** characters actually written into the buffer.)^ We admit that 2276 ** the number of characters written would be a more useful return 2277 ** value but we cannot change the implementation of sqlite3_snprintf() 2278 ** now without breaking compatibility. 2279 ** 2280 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2281 ** guarantees that the buffer is always zero-terminated. ^The first 2282 ** parameter "n" is the total size of the buffer, including space for 2283 ** the zero terminator. So the longest string that can be completely 2284 ** written will be n-1 characters. 2285 ** 2286 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2287 ** 2288 ** These routines all implement some additional formatting 2289 ** options that are useful for constructing SQL statements. 2290 ** All of the usual printf() formatting options apply. In addition, there 2291 ** is are "%q", "%Q", "%w" and "%z" options. 2292 ** 2293 ** ^(The %q option works like %s in that it substitutes a nul-terminated 2294 ** string from the argument list. But %q also doubles every '\'' character. 2295 ** %q is designed for use inside a string literal.)^ By doubling each '\'' 2296 ** character it escapes that character and allows it to be inserted into 2297 ** the string. 2298 ** 2299 ** For example, assume the string variable zText contains text as follows: 2300 ** 2301 ** <blockquote><pre> 2302 ** char *zText = "It's a happy day!"; 2303 ** </pre></blockquote> 2304 ** 2305 ** One can use this text in an SQL statement as follows: 2306 ** 2307 ** <blockquote><pre> 2308 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2309 ** sqlite3_exec(db, zSQL, 0, 0, 0); 2310 ** sqlite3_free(zSQL); 2311 ** </pre></blockquote> 2312 ** 2313 ** Because the %q format string is used, the '\'' character in zText 2314 ** is escaped and the SQL generated is as follows: 2315 ** 2316 ** <blockquote><pre> 2317 ** INSERT INTO table1 VALUES('It''s a happy day!') 2318 ** </pre></blockquote> 2319 ** 2320 ** This is correct. Had we used %s instead of %q, the generated SQL 2321 ** would have looked like this: 2322 ** 2323 ** <blockquote><pre> 2324 ** INSERT INTO table1 VALUES('It's a happy day!'); 2325 ** </pre></blockquote> 2326 ** 2327 ** This second example is an SQL syntax error. As a general rule you should 2328 ** always use %q instead of %s when inserting text into a string literal. 2329 ** 2330 ** ^(The %Q option works like %q except it also adds single quotes around 2331 ** the outside of the total string. Additionally, if the parameter in the 2332 ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2333 ** single quotes).)^ So, for example, one could say: 2334 ** 2335 ** <blockquote><pre> 2336 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2337 ** sqlite3_exec(db, zSQL, 0, 0, 0); 2338 ** sqlite3_free(zSQL); 2339 ** </pre></blockquote> 2340 ** 2341 ** The code above will render a correct SQL statement in the zSQL 2342 ** variable even if the zText variable is a NULL pointer. 2343 ** 2344 ** ^(The "%w" formatting option is like "%q" except that it expects to 2345 ** be contained within double-quotes instead of single quotes, and it 2346 ** escapes the double-quote character instead of the single-quote 2347 ** character.)^ The "%w" formatting option is intended for safely inserting 2348 ** table and column names into a constructed SQL statement. 2349 ** 2350 ** ^(The "%z" formatting option works like "%s" but with the 2351 ** addition that after the string has been read and copied into 2352 ** the result, [sqlite3_free()] is called on the input string.)^ 2353 */ 2354 SQLITE_API char *SQLITE_CDECL sqlite3_mprintf(const char*,...); 2355 SQLITE_API char *SQLITE_STDCALL sqlite3_vmprintf(const char*, va_list); 2356 SQLITE_API char *SQLITE_CDECL sqlite3_snprintf(int,char*,const char*, ...); 2357 SQLITE_API char *SQLITE_STDCALL sqlite3_vsnprintf(int,char*,const char*, va_list); 2358 2359 /* 2360 ** CAPI3REF: Memory Allocation Subsystem 2361 ** 2362 ** The SQLite core uses these three routines for all of its own 2363 ** internal memory allocation needs. "Core" in the previous sentence 2364 ** does not include operating-system specific VFS implementation. The 2365 ** Windows VFS uses native malloc() and free() for some operations. 2366 ** 2367 ** ^The sqlite3_malloc() routine returns a pointer to a block 2368 ** of memory at least N bytes in length, where N is the parameter. 2369 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2370 ** memory, it returns a NULL pointer. ^If the parameter N to 2371 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2372 ** a NULL pointer. 2373 ** 2374 ** ^The sqlite3_malloc64(N) routine works just like 2375 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2376 ** of a signed 32-bit integer. 2377 ** 2378 ** ^Calling sqlite3_free() with a pointer previously returned 2379 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2380 ** that it might be reused. ^The sqlite3_free() routine is 2381 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2382 ** to sqlite3_free() is harmless. After being freed, memory 2383 ** should neither be read nor written. Even reading previously freed 2384 ** memory might result in a segmentation fault or other severe error. 2385 ** Memory corruption, a segmentation fault, or other severe error 2386 ** might result if sqlite3_free() is called with a non-NULL pointer that 2387 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2388 ** 2389 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 2390 ** prior memory allocation X to be at least N bytes. 2391 ** ^If the X parameter to sqlite3_realloc(X,N) 2392 ** is a NULL pointer then its behavior is identical to calling 2393 ** sqlite3_malloc(N). 2394 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2395 ** negative then the behavior is exactly the same as calling 2396 ** sqlite3_free(X). 2397 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2398 ** of at least N bytes in size or NULL if insufficient memory is available. 2399 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2400 ** of the prior allocation are copied into the beginning of buffer returned 2401 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 2402 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2403 ** prior allocation is not freed. 2404 ** 2405 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 2406 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2407 ** of a 32-bit signed integer. 2408 ** 2409 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2410 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2411 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2412 ** ^The value returned by sqlite3_msize(X) might be larger than the number 2413 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 2414 ** sqlite3_msize(X) returns zero. If X points to something that is not 2415 ** the beginning of memory allocation, or if it points to a formerly 2416 ** valid memory allocation that has now been freed, then the behavior 2417 ** of sqlite3_msize(X) is undefined and possibly harmful. 2418 ** 2419 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2420 ** sqlite3_malloc64(), and sqlite3_realloc64() 2421 ** is always aligned to at least an 8 byte boundary, or to a 2422 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2423 ** option is used. 2424 ** 2425 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2426 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2427 ** implementation of these routines to be omitted. That capability 2428 ** is no longer provided. Only built-in memory allocators can be used. 2429 ** 2430 ** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2431 ** the system malloc() and free() directly when converting 2432 ** filenames between the UTF-8 encoding used by SQLite 2433 ** and whatever filename encoding is used by the particular Windows 2434 ** installation. Memory allocation errors were detected, but 2435 ** they were reported back as [SQLITE_CANTOPEN] or 2436 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2437 ** 2438 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2439 ** must be either NULL or else pointers obtained from a prior 2440 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2441 ** not yet been released. 2442 ** 2443 ** The application must not read or write any part of 2444 ** a block of memory after it has been released using 2445 ** [sqlite3_free()] or [sqlite3_realloc()]. 2446 */ 2447 SQLITE_API void *SQLITE_STDCALL sqlite3_malloc(int); 2448 SQLITE_API void *SQLITE_STDCALL sqlite3_malloc64(sqlite3_uint64); 2449 SQLITE_API void *SQLITE_STDCALL sqlite3_realloc(void*, int); 2450 SQLITE_API void *SQLITE_STDCALL sqlite3_realloc64(void*, sqlite3_uint64); 2451 SQLITE_API void SQLITE_STDCALL sqlite3_free(void*); 2452 SQLITE_API sqlite3_uint64 SQLITE_STDCALL sqlite3_msize(void*); 2453 2454 /* 2455 ** CAPI3REF: Memory Allocator Statistics 2456 ** 2457 ** SQLite provides these two interfaces for reporting on the status 2458 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2459 ** routines, which form the built-in memory allocation subsystem. 2460 ** 2461 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2462 ** of memory currently outstanding (malloced but not freed). 2463 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2464 ** value of [sqlite3_memory_used()] since the high-water mark 2465 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2466 ** [sqlite3_memory_highwater()] include any overhead 2467 ** added by SQLite in its implementation of [sqlite3_malloc()], 2468 ** but not overhead added by the any underlying system library 2469 ** routines that [sqlite3_malloc()] may call. 2470 ** 2471 ** ^The memory high-water mark is reset to the current value of 2472 ** [sqlite3_memory_used()] if and only if the parameter to 2473 ** [sqlite3_memory_highwater()] is true. ^The value returned 2474 ** by [sqlite3_memory_highwater(1)] is the high-water mark 2475 ** prior to the reset. 2476 */ 2477 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_used(void); 2478 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_highwater(int resetFlag); 2479 2480 /* 2481 ** CAPI3REF: Pseudo-Random Number Generator 2482 ** 2483 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2484 ** select random [ROWID | ROWIDs] when inserting new records into a table that 2485 ** already uses the largest possible [ROWID]. The PRNG is also used for 2486 ** the build-in random() and randomblob() SQL functions. This interface allows 2487 ** applications to access the same PRNG for other purposes. 2488 ** 2489 ** ^A call to this routine stores N bytes of randomness into buffer P. 2490 ** ^The P parameter can be a NULL pointer. 2491 ** 2492 ** ^If this routine has not been previously called or if the previous 2493 ** call had N less than one or a NULL pointer for P, then the PRNG is 2494 ** seeded using randomness obtained from the xRandomness method of 2495 ** the default [sqlite3_vfs] object. 2496 ** ^If the previous call to this routine had an N of 1 or more and a 2497 ** non-NULL P then the pseudo-randomness is generated 2498 ** internally and without recourse to the [sqlite3_vfs] xRandomness 2499 ** method. 2500 */ 2501 SQLITE_API void SQLITE_STDCALL sqlite3_randomness(int N, void *P); 2502 2503 /* 2504 ** CAPI3REF: Compile-Time Authorization Callbacks 2505 ** 2506 ** ^This routine registers an authorizer callback with a particular 2507 ** [database connection], supplied in the first argument. 2508 ** ^The authorizer callback is invoked as SQL statements are being compiled 2509 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2510 ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2511 ** points during the compilation process, as logic is being created 2512 ** to perform various actions, the authorizer callback is invoked to 2513 ** see if those actions are allowed. ^The authorizer callback should 2514 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2515 ** specific action but allow the SQL statement to continue to be 2516 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2517 ** rejected with an error. ^If the authorizer callback returns 2518 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2519 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2520 ** the authorizer will fail with an error message. 2521 ** 2522 ** When the callback returns [SQLITE_OK], that means the operation 2523 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 2524 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 2525 ** authorizer will fail with an error message explaining that 2526 ** access is denied. 2527 ** 2528 ** ^The first parameter to the authorizer callback is a copy of the third 2529 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2530 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 2531 ** the particular action to be authorized. ^The third through sixth parameters 2532 ** to the callback are zero-terminated strings that contain additional 2533 ** details about the action to be authorized. 2534 ** 2535 ** ^If the action code is [SQLITE_READ] 2536 ** and the callback returns [SQLITE_IGNORE] then the 2537 ** [prepared statement] statement is constructed to substitute 2538 ** a NULL value in place of the table column that would have 2539 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2540 ** return can be used to deny an untrusted user access to individual 2541 ** columns of a table. 2542 ** ^If the action code is [SQLITE_DELETE] and the callback returns 2543 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2544 ** [truncate optimization] is disabled and all rows are deleted individually. 2545 ** 2546 ** An authorizer is used when [sqlite3_prepare | preparing] 2547 ** SQL statements from an untrusted source, to ensure that the SQL statements 2548 ** do not try to access data they are not allowed to see, or that they do not 2549 ** try to execute malicious statements that damage the database. For 2550 ** example, an application may allow a user to enter arbitrary 2551 ** SQL queries for evaluation by a database. But the application does 2552 ** not want the user to be able to make arbitrary changes to the 2553 ** database. An authorizer could then be put in place while the 2554 ** user-entered SQL is being [sqlite3_prepare | prepared] that 2555 ** disallows everything except [SELECT] statements. 2556 ** 2557 ** Applications that need to process SQL from untrusted sources 2558 ** might also consider lowering resource limits using [sqlite3_limit()] 2559 ** and limiting database size using the [max_page_count] [PRAGMA] 2560 ** in addition to using an authorizer. 2561 ** 2562 ** ^(Only a single authorizer can be in place on a database connection 2563 ** at a time. Each call to sqlite3_set_authorizer overrides the 2564 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2565 ** The authorizer is disabled by default. 2566 ** 2567 ** The authorizer callback must not do anything that will modify 2568 ** the database connection that invoked the authorizer callback. 2569 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2570 ** database connections for the meaning of "modify" in this paragraph. 2571 ** 2572 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2573 ** statement might be re-prepared during [sqlite3_step()] due to a 2574 ** schema change. Hence, the application should ensure that the 2575 ** correct authorizer callback remains in place during the [sqlite3_step()]. 2576 ** 2577 ** ^Note that the authorizer callback is invoked only during 2578 ** [sqlite3_prepare()] or its variants. Authorization is not 2579 ** performed during statement evaluation in [sqlite3_step()], unless 2580 ** as stated in the previous paragraph, sqlite3_step() invokes 2581 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2582 */ 2583 SQLITE_API int SQLITE_STDCALL sqlite3_set_authorizer( 2584 sqlite3*, 2585 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2586 void *pUserData 2587 ); 2588 2589 /* 2590 ** CAPI3REF: Authorizer Return Codes 2591 ** 2592 ** The [sqlite3_set_authorizer | authorizer callback function] must 2593 ** return either [SQLITE_OK] or one of these two constants in order 2594 ** to signal SQLite whether or not the action is permitted. See the 2595 ** [sqlite3_set_authorizer | authorizer documentation] for additional 2596 ** information. 2597 ** 2598 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2599 ** returned from the [sqlite3_vtab_on_conflict()] interface. 2600 */ 2601 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2602 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2603 2604 /* 2605 ** CAPI3REF: Authorizer Action Codes 2606 ** 2607 ** The [sqlite3_set_authorizer()] interface registers a callback function 2608 ** that is invoked to authorize certain SQL statement actions. The 2609 ** second parameter to the callback is an integer code that specifies 2610 ** what action is being authorized. These are the integer action codes that 2611 ** the authorizer callback may be passed. 2612 ** 2613 ** These action code values signify what kind of operation is to be 2614 ** authorized. The 3rd and 4th parameters to the authorization 2615 ** callback function will be parameters or NULL depending on which of these 2616 ** codes is used as the second parameter. ^(The 5th parameter to the 2617 ** authorizer callback is the name of the database ("main", "temp", 2618 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2619 ** is the name of the inner-most trigger or view that is responsible for 2620 ** the access attempt or NULL if this access attempt is directly from 2621 ** top-level SQL code. 2622 */ 2623 /******************************************* 3rd ************ 4th ***********/ 2624 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2625 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2626 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2627 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2628 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2629 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2630 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2631 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2632 #define SQLITE_DELETE 9 /* Table Name NULL */ 2633 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2634 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2635 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2636 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2637 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2638 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2639 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2640 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2641 #define SQLITE_INSERT 18 /* Table Name NULL */ 2642 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2643 #define SQLITE_READ 20 /* Table Name Column Name */ 2644 #define SQLITE_SELECT 21 /* NULL NULL */ 2645 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 2646 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 2647 #define SQLITE_ATTACH 24 /* Filename NULL */ 2648 #define SQLITE_DETACH 25 /* Database Name NULL */ 2649 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2650 #define SQLITE_REINDEX 27 /* Index Name NULL */ 2651 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 2652 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2653 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2654 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 2655 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2656 #define SQLITE_COPY 0 /* No longer used */ 2657 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 2658 2659 /* 2660 ** CAPI3REF: Tracing And Profiling Functions 2661 ** 2662 ** These routines register callback functions that can be used for 2663 ** tracing and profiling the execution of SQL statements. 2664 ** 2665 ** ^The callback function registered by sqlite3_trace() is invoked at 2666 ** various times when an SQL statement is being run by [sqlite3_step()]. 2667 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2668 ** SQL statement text as the statement first begins executing. 2669 ** ^(Additional sqlite3_trace() callbacks might occur 2670 ** as each triggered subprogram is entered. The callbacks for triggers 2671 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 2672 ** 2673 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2674 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2675 ** 2676 ** ^The callback function registered by sqlite3_profile() is invoked 2677 ** as each SQL statement finishes. ^The profile callback contains 2678 ** the original statement text and an estimate of wall-clock time 2679 ** of how long that statement took to run. ^The profile callback 2680 ** time is in units of nanoseconds, however the current implementation 2681 ** is only capable of millisecond resolution so the six least significant 2682 ** digits in the time are meaningless. Future versions of SQLite 2683 ** might provide greater resolution on the profiler callback. The 2684 ** sqlite3_profile() function is considered experimental and is 2685 ** subject to change in future versions of SQLite. 2686 */ 2687 SQLITE_API void *SQLITE_STDCALL sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2688 SQLITE_API SQLITE_EXPERIMENTAL void *SQLITE_STDCALL sqlite3_profile(sqlite3*, 2689 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2690 2691 /* 2692 ** CAPI3REF: Query Progress Callbacks 2693 ** 2694 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2695 ** function X to be invoked periodically during long running calls to 2696 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2697 ** database connection D. An example use for this 2698 ** interface is to keep a GUI updated during a large query. 2699 ** 2700 ** ^The parameter P is passed through as the only parameter to the 2701 ** callback function X. ^The parameter N is the approximate number of 2702 ** [virtual machine instructions] that are evaluated between successive 2703 ** invocations of the callback X. ^If N is less than one then the progress 2704 ** handler is disabled. 2705 ** 2706 ** ^Only a single progress handler may be defined at one time per 2707 ** [database connection]; setting a new progress handler cancels the 2708 ** old one. ^Setting parameter X to NULL disables the progress handler. 2709 ** ^The progress handler is also disabled by setting N to a value less 2710 ** than 1. 2711 ** 2712 ** ^If the progress callback returns non-zero, the operation is 2713 ** interrupted. This feature can be used to implement a 2714 ** "Cancel" button on a GUI progress dialog box. 2715 ** 2716 ** The progress handler callback must not do anything that will modify 2717 ** the database connection that invoked the progress handler. 2718 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2719 ** database connections for the meaning of "modify" in this paragraph. 2720 ** 2721 */ 2722 SQLITE_API void SQLITE_STDCALL sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2723 2724 /* 2725 ** CAPI3REF: Opening A New Database Connection 2726 ** 2727 ** ^These routines open an SQLite database file as specified by the 2728 ** filename argument. ^The filename argument is interpreted as UTF-8 for 2729 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2730 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 2731 ** returned in *ppDb, even if an error occurs. The only exception is that 2732 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2733 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2734 ** object.)^ ^(If the database is opened (and/or created) successfully, then 2735 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2736 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2737 ** an English language description of the error following a failure of any 2738 ** of the sqlite3_open() routines. 2739 ** 2740 ** ^The default encoding will be UTF-8 for databases created using 2741 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 2742 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 2743 ** 2744 ** Whether or not an error occurs when it is opened, resources 2745 ** associated with the [database connection] handle should be released by 2746 ** passing it to [sqlite3_close()] when it is no longer required. 2747 ** 2748 ** The sqlite3_open_v2() interface works like sqlite3_open() 2749 ** except that it accepts two additional parameters for additional control 2750 ** over the new database connection. ^(The flags parameter to 2751 ** sqlite3_open_v2() can take one of 2752 ** the following three values, optionally combined with the 2753 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2754 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2755 ** 2756 ** <dl> 2757 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2758 ** <dd>The database is opened in read-only mode. If the database does not 2759 ** already exist, an error is returned.</dd>)^ 2760 ** 2761 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2762 ** <dd>The database is opened for reading and writing if possible, or reading 2763 ** only if the file is write protected by the operating system. In either 2764 ** case the database must already exist, otherwise an error is returned.</dd>)^ 2765 ** 2766 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2767 ** <dd>The database is opened for reading and writing, and is created if 2768 ** it does not already exist. This is the behavior that is always used for 2769 ** sqlite3_open() and sqlite3_open16().</dd>)^ 2770 ** </dl> 2771 ** 2772 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 2773 ** combinations shown above optionally combined with other 2774 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2775 ** then the behavior is undefined. 2776 ** 2777 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2778 ** opens in the multi-thread [threading mode] as long as the single-thread 2779 ** mode has not been set at compile-time or start-time. ^If the 2780 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2781 ** in the serialized [threading mode] unless single-thread was 2782 ** previously selected at compile-time or start-time. 2783 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2784 ** eligible to use [shared cache mode], regardless of whether or not shared 2785 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 2786 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 2787 ** participate in [shared cache mode] even if it is enabled. 2788 ** 2789 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 2790 ** [sqlite3_vfs] object that defines the operating system interface that 2791 ** the new database connection should use. ^If the fourth parameter is 2792 ** a NULL pointer then the default [sqlite3_vfs] object is used. 2793 ** 2794 ** ^If the filename is ":memory:", then a private, temporary in-memory database 2795 ** is created for the connection. ^This in-memory database will vanish when 2796 ** the database connection is closed. Future versions of SQLite might 2797 ** make use of additional special filenames that begin with the ":" character. 2798 ** It is recommended that when a database filename actually does begin with 2799 ** a ":" character you should prefix the filename with a pathname such as 2800 ** "./" to avoid ambiguity. 2801 ** 2802 ** ^If the filename is an empty string, then a private, temporary 2803 ** on-disk database will be created. ^This private database will be 2804 ** automatically deleted as soon as the database connection is closed. 2805 ** 2806 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 2807 ** 2808 ** ^If [URI filename] interpretation is enabled, and the filename argument 2809 ** begins with "file:", then the filename is interpreted as a URI. ^URI 2810 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 2811 ** set in the fourth argument to sqlite3_open_v2(), or if it has 2812 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 2813 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 2814 ** As of SQLite version 3.7.7, URI filename interpretation is turned off 2815 ** by default, but future releases of SQLite might enable URI filename 2816 ** interpretation by default. See "[URI filenames]" for additional 2817 ** information. 2818 ** 2819 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 2820 ** authority, then it must be either an empty string or the string 2821 ** "localhost". ^If the authority is not an empty string or "localhost", an 2822 ** error is returned to the caller. ^The fragment component of a URI, if 2823 ** present, is ignored. 2824 ** 2825 ** ^SQLite uses the path component of the URI as the name of the disk file 2826 ** which contains the database. ^If the path begins with a '/' character, 2827 ** then it is interpreted as an absolute path. ^If the path does not begin 2828 ** with a '/' (meaning that the authority section is omitted from the URI) 2829 ** then the path is interpreted as a relative path. 2830 ** ^(On windows, the first component of an absolute path 2831 ** is a drive specification (e.g. "C:").)^ 2832 ** 2833 ** [[core URI query parameters]] 2834 ** The query component of a URI may contain parameters that are interpreted 2835 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 2836 ** SQLite and its built-in [VFSes] interpret the 2837 ** following query parameters: 2838 ** 2839 ** <ul> 2840 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 2841 ** a VFS object that provides the operating system interface that should 2842 ** be used to access the database file on disk. ^If this option is set to 2843 ** an empty string the default VFS object is used. ^Specifying an unknown 2844 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 2845 ** present, then the VFS specified by the option takes precedence over 2846 ** the value passed as the fourth parameter to sqlite3_open_v2(). 2847 ** 2848 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 2849 ** "rwc", or "memory". Attempting to set it to any other value is 2850 ** an error)^. 2851 ** ^If "ro" is specified, then the database is opened for read-only 2852 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 2853 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 2854 ** "rw", then the database is opened for read-write (but not create) 2855 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 2856 ** been set. ^Value "rwc" is equivalent to setting both 2857 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 2858 ** set to "memory" then a pure [in-memory database] that never reads 2859 ** or writes from disk is used. ^It is an error to specify a value for 2860 ** the mode parameter that is less restrictive than that specified by 2861 ** the flags passed in the third parameter to sqlite3_open_v2(). 2862 ** 2863 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 2864 ** "private". ^Setting it to "shared" is equivalent to setting the 2865 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 2866 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 2867 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 2868 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 2869 ** a URI filename, its value overrides any behavior requested by setting 2870 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 2871 ** 2872 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 2873 ** [powersafe overwrite] property does or does not apply to the 2874 ** storage media on which the database file resides. 2875 ** 2876 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 2877 ** which if set disables file locking in rollback journal modes. This 2878 ** is useful for accessing a database on a filesystem that does not 2879 ** support locking. Caution: Database corruption might result if two 2880 ** or more processes write to the same database and any one of those 2881 ** processes uses nolock=1. 2882 ** 2883 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 2884 ** parameter that indicates that the database file is stored on 2885 ** read-only media. ^When immutable is set, SQLite assumes that the 2886 ** database file cannot be changed, even by a process with higher 2887 ** privilege, and so the database is opened read-only and all locking 2888 ** and change detection is disabled. Caution: Setting the immutable 2889 ** property on a database file that does in fact change can result 2890 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 2891 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 2892 ** 2893 ** </ul> 2894 ** 2895 ** ^Specifying an unknown parameter in the query component of a URI is not an 2896 ** error. Future versions of SQLite might understand additional query 2897 ** parameters. See "[query parameters with special meaning to SQLite]" for 2898 ** additional information. 2899 ** 2900 ** [[URI filename examples]] <h3>URI filename examples</h3> 2901 ** 2902 ** <table border="1" align=center cellpadding=5> 2903 ** <tr><th> URI filenames <th> Results 2904 ** <tr><td> file:data.db <td> 2905 ** Open the file "data.db" in the current directory. 2906 ** <tr><td> file:/home/fred/data.db<br> 2907 ** file:///home/fred/data.db <br> 2908 ** file://localhost/home/fred/data.db <br> <td> 2909 ** Open the database file "/home/fred/data.db". 2910 ** <tr><td> file://darkstar/home/fred/data.db <td> 2911 ** An error. "darkstar" is not a recognized authority. 2912 ** <tr><td style="white-space:nowrap"> 2913 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 2914 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 2915 ** C:. Note that the %20 escaping in this example is not strictly 2916 ** necessary - space characters can be used literally 2917 ** in URI filenames. 2918 ** <tr><td> file:data.db?mode=ro&cache=private <td> 2919 ** Open file "data.db" in the current directory for read-only access. 2920 ** Regardless of whether or not shared-cache mode is enabled by 2921 ** default, use a private cache. 2922 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 2923 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 2924 ** that uses dot-files in place of posix advisory locking. 2925 ** <tr><td> file:data.db?mode=readonly <td> 2926 ** An error. "readonly" is not a valid option for the "mode" parameter. 2927 ** </table> 2928 ** 2929 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 2930 ** query components of a URI. A hexadecimal escape sequence consists of a 2931 ** percent sign - "%" - followed by exactly two hexadecimal digits 2932 ** specifying an octet value. ^Before the path or query components of a 2933 ** URI filename are interpreted, they are encoded using UTF-8 and all 2934 ** hexadecimal escape sequences replaced by a single byte containing the 2935 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 2936 ** the results are undefined. 2937 ** 2938 ** <b>Note to Windows users:</b> The encoding used for the filename argument 2939 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2940 ** codepage is currently defined. Filenames containing international 2941 ** characters must be converted to UTF-8 prior to passing them into 2942 ** sqlite3_open() or sqlite3_open_v2(). 2943 ** 2944 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 2945 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 2946 ** features that require the use of temporary files may fail. 2947 ** 2948 ** See also: [sqlite3_temp_directory] 2949 */ 2950 SQLITE_API int SQLITE_STDCALL sqlite3_open( 2951 const char *filename, /* Database filename (UTF-8) */ 2952 sqlite3 **ppDb /* OUT: SQLite db handle */ 2953 ); 2954 SQLITE_API int SQLITE_STDCALL sqlite3_open16( 2955 const void *filename, /* Database filename (UTF-16) */ 2956 sqlite3 **ppDb /* OUT: SQLite db handle */ 2957 ); 2958 SQLITE_API int SQLITE_STDCALL sqlite3_open_v2( 2959 const char *filename, /* Database filename (UTF-8) */ 2960 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2961 int flags, /* Flags */ 2962 const char *zVfs /* Name of VFS module to use */ 2963 ); 2964 2965 /* 2966 ** CAPI3REF: Obtain Values For URI Parameters 2967 ** 2968 ** These are utility routines, useful to VFS implementations, that check 2969 ** to see if a database file was a URI that contained a specific query 2970 ** parameter, and if so obtains the value of that query parameter. 2971 ** 2972 ** If F is the database filename pointer passed into the xOpen() method of 2973 ** a VFS implementation when the flags parameter to xOpen() has one or 2974 ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 2975 ** P is the name of the query parameter, then 2976 ** sqlite3_uri_parameter(F,P) returns the value of the P 2977 ** parameter if it exists or a NULL pointer if P does not appear as a 2978 ** query parameter on F. If P is a query parameter of F 2979 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 2980 ** a pointer to an empty string. 2981 ** 2982 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 2983 ** parameter and returns true (1) or false (0) according to the value 2984 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 2985 ** value of query parameter P is one of "yes", "true", or "on" in any 2986 ** case or if the value begins with a non-zero number. The 2987 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 2988 ** query parameter P is one of "no", "false", or "off" in any case or 2989 ** if the value begins with a numeric zero. If P is not a query 2990 ** parameter on F or if the value of P is does not match any of the 2991 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 2992 ** 2993 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 2994 ** 64-bit signed integer and returns that integer, or D if P does not 2995 ** exist. If the value of P is something other than an integer, then 2996 ** zero is returned. 2997 ** 2998 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 2999 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3000 ** is not a database file pathname pointer that SQLite passed into the xOpen 3001 ** VFS method, then the behavior of this routine is undefined and probably 3002 ** undesirable. 3003 */ 3004 SQLITE_API const char *SQLITE_STDCALL sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3005 SQLITE_API int SQLITE_STDCALL sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3006 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3007 3008 3009 /* 3010 ** CAPI3REF: Error Codes And Messages 3011 ** 3012 ** ^If the most recent sqlite3_* API call associated with 3013 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3014 ** returns the numeric [result code] or [extended result code] for that 3015 ** API call. 3016 ** If the most recent API call was successful, 3017 ** then the return value from sqlite3_errcode() is undefined. 3018 ** ^The sqlite3_extended_errcode() 3019 ** interface is the same except that it always returns the 3020 ** [extended result code] even when extended result codes are 3021 ** disabled. 3022 ** 3023 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3024 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3025 ** ^(Memory to hold the error message string is managed internally. 3026 ** The application does not need to worry about freeing the result. 3027 ** However, the error string might be overwritten or deallocated by 3028 ** subsequent calls to other SQLite interface functions.)^ 3029 ** 3030 ** ^The sqlite3_errstr() interface returns the English-language text 3031 ** that describes the [result code], as UTF-8. 3032 ** ^(Memory to hold the error message string is managed internally 3033 ** and must not be freed by the application)^. 3034 ** 3035 ** When the serialized [threading mode] is in use, it might be the 3036 ** case that a second error occurs on a separate thread in between 3037 ** the time of the first error and the call to these interfaces. 3038 ** When that happens, the second error will be reported since these 3039 ** interfaces always report the most recent result. To avoid 3040 ** this, each thread can obtain exclusive use of the [database connection] D 3041 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3042 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3043 ** all calls to the interfaces listed here are completed. 3044 ** 3045 ** If an interface fails with SQLITE_MISUSE, that means the interface 3046 ** was invoked incorrectly by the application. In that case, the 3047 ** error code and message may or may not be set. 3048 */ 3049 SQLITE_API int SQLITE_STDCALL sqlite3_errcode(sqlite3 *db); 3050 SQLITE_API int SQLITE_STDCALL sqlite3_extended_errcode(sqlite3 *db); 3051 SQLITE_API const char *SQLITE_STDCALL sqlite3_errmsg(sqlite3*); 3052 SQLITE_API const void *SQLITE_STDCALL sqlite3_errmsg16(sqlite3*); 3053 SQLITE_API const char *SQLITE_STDCALL sqlite3_errstr(int); 3054 3055 /* 3056 ** CAPI3REF: SQL Statement Object 3057 ** KEYWORDS: {prepared statement} {prepared statements} 3058 ** 3059 ** An instance of this object represents a single SQL statement. 3060 ** This object is variously known as a "prepared statement" or a 3061 ** "compiled SQL statement" or simply as a "statement". 3062 ** 3063 ** The life of a statement object goes something like this: 3064 ** 3065 ** <ol> 3066 ** <li> Create the object using [sqlite3_prepare_v2()] or a related 3067 ** function. 3068 ** <li> Bind values to [host parameters] using the sqlite3_bind_*() 3069 ** interfaces. 3070 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3071 ** <li> Reset the statement using [sqlite3_reset()] then go back 3072 ** to step 2. Do this zero or more times. 3073 ** <li> Destroy the object using [sqlite3_finalize()]. 3074 ** </ol> 3075 ** 3076 ** Refer to documentation on individual methods above for additional 3077 ** information. 3078 */ 3079 typedef struct sqlite3_stmt sqlite3_stmt; 3080 3081 /* 3082 ** CAPI3REF: Run-time Limits 3083 ** 3084 ** ^(This interface allows the size of various constructs to be limited 3085 ** on a connection by connection basis. The first parameter is the 3086 ** [database connection] whose limit is to be set or queried. The 3087 ** second parameter is one of the [limit categories] that define a 3088 ** class of constructs to be size limited. The third parameter is the 3089 ** new limit for that construct.)^ 3090 ** 3091 ** ^If the new limit is a negative number, the limit is unchanged. 3092 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3093 ** [limits | hard upper bound] 3094 ** set at compile-time by a C preprocessor macro called 3095 ** [limits | SQLITE_MAX_<i>NAME</i>]. 3096 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3097 ** ^Attempts to increase a limit above its hard upper bound are 3098 ** silently truncated to the hard upper bound. 3099 ** 3100 ** ^Regardless of whether or not the limit was changed, the 3101 ** [sqlite3_limit()] interface returns the prior value of the limit. 3102 ** ^Hence, to find the current value of a limit without changing it, 3103 ** simply invoke this interface with the third parameter set to -1. 3104 ** 3105 ** Run-time limits are intended for use in applications that manage 3106 ** both their own internal database and also databases that are controlled 3107 ** by untrusted external sources. An example application might be a 3108 ** web browser that has its own databases for storing history and 3109 ** separate databases controlled by JavaScript applications downloaded 3110 ** off the Internet. The internal databases can be given the 3111 ** large, default limits. Databases managed by external sources can 3112 ** be given much smaller limits designed to prevent a denial of service 3113 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3114 ** interface to further control untrusted SQL. The size of the database 3115 ** created by an untrusted script can be contained using the 3116 ** [max_page_count] [PRAGMA]. 3117 ** 3118 ** New run-time limit categories may be added in future releases. 3119 */ 3120 SQLITE_API int SQLITE_STDCALL sqlite3_limit(sqlite3*, int id, int newVal); 3121 3122 /* 3123 ** CAPI3REF: Run-Time Limit Categories 3124 ** KEYWORDS: {limit category} {*limit categories} 3125 ** 3126 ** These constants define various performance limits 3127 ** that can be lowered at run-time using [sqlite3_limit()]. 3128 ** The synopsis of the meanings of the various limits is shown below. 3129 ** Additional information is available at [limits | Limits in SQLite]. 3130 ** 3131 ** <dl> 3132 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3133 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3134 ** 3135 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3136 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3137 ** 3138 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3139 ** <dd>The maximum number of columns in a table definition or in the 3140 ** result set of a [SELECT] or the maximum number of columns in an index 3141 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 3142 ** 3143 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3144 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3145 ** 3146 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3147 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3148 ** 3149 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3150 ** <dd>The maximum number of instructions in a virtual machine program 3151 ** used to implement an SQL statement. This limit is not currently 3152 ** enforced, though that might be added in some future release of 3153 ** SQLite.</dd>)^ 3154 ** 3155 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3156 ** <dd>The maximum number of arguments on a function.</dd>)^ 3157 ** 3158 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3159 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3160 ** 3161 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3162 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3163 ** <dd>The maximum length of the pattern argument to the [LIKE] or 3164 ** [GLOB] operators.</dd>)^ 3165 ** 3166 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3167 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3168 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3169 ** 3170 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3171 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 3172 ** 3173 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3174 ** <dd>The maximum number of auxiliary worker threads that a single 3175 ** [prepared statement] may start.</dd>)^ 3176 ** </dl> 3177 */ 3178 #define SQLITE_LIMIT_LENGTH 0 3179 #define SQLITE_LIMIT_SQL_LENGTH 1 3180 #define SQLITE_LIMIT_COLUMN 2 3181 #define SQLITE_LIMIT_EXPR_DEPTH 3 3182 #define SQLITE_LIMIT_COMPOUND_SELECT 4 3183 #define SQLITE_LIMIT_VDBE_OP 5 3184 #define SQLITE_LIMIT_FUNCTION_ARG 6 3185 #define SQLITE_LIMIT_ATTACHED 7 3186 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3187 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 3188 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 3189 #define SQLITE_LIMIT_WORKER_THREADS 11 3190 3191 /* 3192 ** CAPI3REF: Compiling An SQL Statement 3193 ** KEYWORDS: {SQL statement compiler} 3194 ** 3195 ** To execute an SQL query, it must first be compiled into a byte-code 3196 ** program using one of these routines. 3197 ** 3198 ** The first argument, "db", is a [database connection] obtained from a 3199 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3200 ** [sqlite3_open16()]. The database connection must not have been closed. 3201 ** 3202 ** The second argument, "zSql", is the statement to be compiled, encoded 3203 ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3204 ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3205 ** use UTF-16. 3206 ** 3207 ** ^If the nByte argument is negative, then zSql is read up to the 3208 ** first zero terminator. ^If nByte is positive, then it is the 3209 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 3210 ** statement is generated. 3211 ** If the caller knows that the supplied string is nul-terminated, then 3212 ** there is a small performance advantage to passing an nByte parameter that 3213 ** is the number of bytes in the input string <i>including</i> 3214 ** the nul-terminator. 3215 ** 3216 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3217 ** past the end of the first SQL statement in zSql. These routines only 3218 ** compile the first statement in zSql, so *pzTail is left pointing to 3219 ** what remains uncompiled. 3220 ** 3221 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3222 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3223 ** to NULL. ^If the input text contains no SQL (if the input is an empty 3224 ** string or a comment) then *ppStmt is set to NULL. 3225 ** The calling procedure is responsible for deleting the compiled 3226 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 3227 ** ppStmt may not be NULL. 3228 ** 3229 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3230 ** otherwise an [error code] is returned. 3231 ** 3232 ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3233 ** recommended for all new programs. The two older interfaces are retained 3234 ** for backwards compatibility, but their use is discouraged. 3235 ** ^In the "v2" interfaces, the prepared statement 3236 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 3237 ** original SQL text. This causes the [sqlite3_step()] interface to 3238 ** behave differently in three ways: 3239 ** 3240 ** <ol> 3241 ** <li> 3242 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3243 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 3244 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3245 ** retries will occur before sqlite3_step() gives up and returns an error. 3246 ** </li> 3247 ** 3248 ** <li> 3249 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3250 ** [error codes] or [extended error codes]. ^The legacy behavior was that 3251 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3252 ** and the application would have to make a second call to [sqlite3_reset()] 3253 ** in order to find the underlying cause of the problem. With the "v2" prepare 3254 ** interfaces, the underlying reason for the error is returned immediately. 3255 ** </li> 3256 ** 3257 ** <li> 3258 ** ^If the specific value bound to [parameter | host parameter] in the 3259 ** WHERE clause might influence the choice of query plan for a statement, 3260 ** then the statement will be automatically recompiled, as if there had been 3261 ** a schema change, on the first [sqlite3_step()] call following any change 3262 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 3263 ** ^The specific value of WHERE-clause [parameter] might influence the 3264 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 3265 ** or [GLOB] operator or if the parameter is compared to an indexed column 3266 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3267 ** </li> 3268 ** </ol> 3269 */ 3270 SQLITE_API int SQLITE_STDCALL sqlite3_prepare( 3271 sqlite3 *db, /* Database handle */ 3272 const char *zSql, /* SQL statement, UTF-8 encoded */ 3273 int nByte, /* Maximum length of zSql in bytes. */ 3274 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3275 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3276 ); 3277 SQLITE_API int SQLITE_STDCALL sqlite3_prepare_v2( 3278 sqlite3 *db, /* Database handle */ 3279 const char *zSql, /* SQL statement, UTF-8 encoded */ 3280 int nByte, /* Maximum length of zSql in bytes. */ 3281 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3282 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3283 ); 3284 SQLITE_API int SQLITE_STDCALL sqlite3_prepare16( 3285 sqlite3 *db, /* Database handle */ 3286 const void *zSql, /* SQL statement, UTF-16 encoded */ 3287 int nByte, /* Maximum length of zSql in bytes. */ 3288 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3289 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3290 ); 3291 SQLITE_API int SQLITE_STDCALL sqlite3_prepare16_v2( 3292 sqlite3 *db, /* Database handle */ 3293 const void *zSql, /* SQL statement, UTF-16 encoded */ 3294 int nByte, /* Maximum length of zSql in bytes. */ 3295 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3296 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3297 ); 3298 3299 /* 3300 ** CAPI3REF: Retrieving Statement SQL 3301 ** 3302 ** ^This interface can be used to retrieve a saved copy of the original 3303 ** SQL text used to create a [prepared statement] if that statement was 3304 ** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3305 */ 3306 SQLITE_API const char *SQLITE_STDCALL sqlite3_sql(sqlite3_stmt *pStmt); 3307 3308 /* 3309 ** CAPI3REF: Determine If An SQL Statement Writes The Database 3310 ** 3311 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3312 ** and only if the [prepared statement] X makes no direct changes to 3313 ** the content of the database file. 3314 ** 3315 ** Note that [application-defined SQL functions] or 3316 ** [virtual tables] might change the database indirectly as a side effect. 3317 ** ^(For example, if an application defines a function "eval()" that 3318 ** calls [sqlite3_exec()], then the following SQL statement would 3319 ** change the database file through side-effects: 3320 ** 3321 ** <blockquote><pre> 3322 ** SELECT eval('DELETE FROM t1') FROM t2; 3323 ** </pre></blockquote> 3324 ** 3325 ** But because the [SELECT] statement does not change the database file 3326 ** directly, sqlite3_stmt_readonly() would still return true.)^ 3327 ** 3328 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3329 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3330 ** since the statements themselves do not actually modify the database but 3331 ** rather they control the timing of when other statements modify the 3332 ** database. ^The [ATTACH] and [DETACH] statements also cause 3333 ** sqlite3_stmt_readonly() to return true since, while those statements 3334 ** change the configuration of a database connection, they do not make 3335 ** changes to the content of the database files on disk. 3336 */ 3337 SQLITE_API int SQLITE_STDCALL sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3338 3339 /* 3340 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3341 ** 3342 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3343 ** [prepared statement] S has been stepped at least once using 3344 ** [sqlite3_step(S)] but has not run to completion and/or has not 3345 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3346 ** interface returns false if S is a NULL pointer. If S is not a 3347 ** NULL pointer and is not a pointer to a valid [prepared statement] 3348 ** object, then the behavior is undefined and probably undesirable. 3349 ** 3350 ** This interface can be used in combination [sqlite3_next_stmt()] 3351 ** to locate all prepared statements associated with a database 3352 ** connection that are in need of being reset. This can be used, 3353 ** for example, in diagnostic routines to search for prepared 3354 ** statements that are holding a transaction open. 3355 */ 3356 SQLITE_API int SQLITE_STDCALL sqlite3_stmt_busy(sqlite3_stmt*); 3357 3358 /* 3359 ** CAPI3REF: Dynamically Typed Value Object 3360 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3361 ** 3362 ** SQLite uses the sqlite3_value object to represent all values 3363 ** that can be stored in a database table. SQLite uses dynamic typing 3364 ** for the values it stores. ^Values stored in sqlite3_value objects 3365 ** can be integers, floating point values, strings, BLOBs, or NULL. 3366 ** 3367 ** An sqlite3_value object may be either "protected" or "unprotected". 3368 ** Some interfaces require a protected sqlite3_value. Other interfaces 3369 ** will accept either a protected or an unprotected sqlite3_value. 3370 ** Every interface that accepts sqlite3_value arguments specifies 3371 ** whether or not it requires a protected sqlite3_value. 3372 ** 3373 ** The terms "protected" and "unprotected" refer to whether or not 3374 ** a mutex is held. An internal mutex is held for a protected 3375 ** sqlite3_value object but no mutex is held for an unprotected 3376 ** sqlite3_value object. If SQLite is compiled to be single-threaded 3377 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3378 ** or if SQLite is run in one of reduced mutex modes 3379 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3380 ** then there is no distinction between protected and unprotected 3381 ** sqlite3_value objects and they can be used interchangeably. However, 3382 ** for maximum code portability it is recommended that applications 3383 ** still make the distinction between protected and unprotected 3384 ** sqlite3_value objects even when not strictly required. 3385 ** 3386 ** ^The sqlite3_value objects that are passed as parameters into the 3387 ** implementation of [application-defined SQL functions] are protected. 3388 ** ^The sqlite3_value object returned by 3389 ** [sqlite3_column_value()] is unprotected. 3390 ** Unprotected sqlite3_value objects may only be used with 3391 ** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3392 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 3393 ** interfaces require protected sqlite3_value objects. 3394 */ 3395 typedef struct Mem sqlite3_value; 3396 3397 /* 3398 ** CAPI3REF: SQL Function Context Object 3399 ** 3400 ** The context in which an SQL function executes is stored in an 3401 ** sqlite3_context object. ^A pointer to an sqlite3_context object 3402 ** is always first parameter to [application-defined SQL functions]. 3403 ** The application-defined SQL function implementation will pass this 3404 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3405 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3406 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3407 ** and/or [sqlite3_set_auxdata()]. 3408 */ 3409 typedef struct sqlite3_context sqlite3_context; 3410 3411 /* 3412 ** CAPI3REF: Binding Values To Prepared Statements 3413 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3414 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3415 ** 3416 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3417 ** literals may be replaced by a [parameter] that matches one of following 3418 ** templates: 3419 ** 3420 ** <ul> 3421 ** <li> ? 3422 ** <li> ?NNN 3423 ** <li> :VVV 3424 ** <li> @VVV 3425 ** <li> $VVV 3426 ** </ul> 3427 ** 3428 ** In the templates above, NNN represents an integer literal, 3429 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 3430 ** parameters (also called "host parameter names" or "SQL parameters") 3431 ** can be set using the sqlite3_bind_*() routines defined here. 3432 ** 3433 ** ^The first argument to the sqlite3_bind_*() routines is always 3434 ** a pointer to the [sqlite3_stmt] object returned from 3435 ** [sqlite3_prepare_v2()] or its variants. 3436 ** 3437 ** ^The second argument is the index of the SQL parameter to be set. 3438 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 3439 ** SQL parameter is used more than once, second and subsequent 3440 ** occurrences have the same index as the first occurrence. 3441 ** ^The index for named parameters can be looked up using the 3442 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 3443 ** for "?NNN" parameters is the value of NNN. 3444 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 3445 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3446 ** 3447 ** ^The third argument is the value to bind to the parameter. 3448 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3449 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3450 ** is ignored and the end result is the same as sqlite3_bind_null(). 3451 ** 3452 ** ^(In those routines that have a fourth argument, its value is the 3453 ** number of bytes in the parameter. To be clear: the value is the 3454 ** number of <u>bytes</u> in the value, not the number of characters.)^ 3455 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3456 ** is negative, then the length of the string is 3457 ** the number of bytes up to the first zero terminator. 3458 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 3459 ** the behavior is undefined. 3460 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3461 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3462 ** that parameter must be the byte offset 3463 ** where the NUL terminator would occur assuming the string were NUL 3464 ** terminated. If any NUL characters occur at byte offsets less than 3465 ** the value of the fourth parameter then the resulting string value will 3466 ** contain embedded NULs. The result of expressions involving strings 3467 ** with embedded NULs is undefined. 3468 ** 3469 ** ^The fifth argument to the BLOB and string binding interfaces 3470 ** is a destructor used to dispose of the BLOB or 3471 ** string after SQLite has finished with it. ^The destructor is called 3472 ** to dispose of the BLOB or string even if the call to bind API fails. 3473 ** ^If the fifth argument is 3474 ** the special value [SQLITE_STATIC], then SQLite assumes that the 3475 ** information is in static, unmanaged space and does not need to be freed. 3476 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3477 ** SQLite makes its own private copy of the data immediately, before 3478 ** the sqlite3_bind_*() routine returns. 3479 ** 3480 ** ^The sixth argument to sqlite3_bind_text64() must be one of 3481 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3482 ** to specify the encoding of the text in the third parameter. If 3483 ** the sixth argument to sqlite3_bind_text64() is not one of the 3484 ** allowed values shown above, or if the text encoding is different 3485 ** from the encoding specified by the sixth parameter, then the behavior 3486 ** is undefined. 3487 ** 3488 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3489 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3490 ** (just an integer to hold its size) while it is being processed. 3491 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 3492 ** content is later written using 3493 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 3494 ** ^A negative value for the zeroblob results in a zero-length BLOB. 3495 ** 3496 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3497 ** for the [prepared statement] or with a prepared statement for which 3498 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3499 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3500 ** routine is passed a [prepared statement] that has been finalized, the 3501 ** result is undefined and probably harmful. 3502 ** 3503 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3504 ** ^Unbound parameters are interpreted as NULL. 3505 ** 3506 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3507 ** [error code] if anything goes wrong. 3508 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 3509 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 3510 ** [SQLITE_MAX_LENGTH]. 3511 ** ^[SQLITE_RANGE] is returned if the parameter 3512 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3513 ** 3514 ** See also: [sqlite3_bind_parameter_count()], 3515 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3516 */ 3517 SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3518 SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 3519 void(*)(void*)); 3520 SQLITE_API int SQLITE_STDCALL sqlite3_bind_double(sqlite3_stmt*, int, double); 3521 SQLITE_API int SQLITE_STDCALL sqlite3_bind_int(sqlite3_stmt*, int, int); 3522 SQLITE_API int SQLITE_STDCALL sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3523 SQLITE_API int SQLITE_STDCALL sqlite3_bind_null(sqlite3_stmt*, int); 3524 SQLITE_API int SQLITE_STDCALL sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 3525 SQLITE_API int SQLITE_STDCALL sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3526 SQLITE_API int SQLITE_STDCALL sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 3527 void(*)(void*), unsigned char encoding); 3528 SQLITE_API int SQLITE_STDCALL sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3529 SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3530 3531 /* 3532 ** CAPI3REF: Number Of SQL Parameters 3533 ** 3534 ** ^This routine can be used to find the number of [SQL parameters] 3535 ** in a [prepared statement]. SQL parameters are tokens of the 3536 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3537 ** placeholders for values that are [sqlite3_bind_blob | bound] 3538 ** to the parameters at a later time. 3539 ** 3540 ** ^(This routine actually returns the index of the largest (rightmost) 3541 ** parameter. For all forms except ?NNN, this will correspond to the 3542 ** number of unique parameters. If parameters of the ?NNN form are used, 3543 ** there may be gaps in the list.)^ 3544 ** 3545 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3546 ** [sqlite3_bind_parameter_name()], and 3547 ** [sqlite3_bind_parameter_index()]. 3548 */ 3549 SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_count(sqlite3_stmt*); 3550 3551 /* 3552 ** CAPI3REF: Name Of A Host Parameter 3553 ** 3554 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 3555 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 3556 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3557 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3558 ** respectively. 3559 ** In other words, the initial ":" or "$" or "@" or "?" 3560 ** is included as part of the name.)^ 3561 ** ^Parameters of the form "?" without a following integer have no name 3562 ** and are referred to as "nameless" or "anonymous parameters". 3563 ** 3564 ** ^The first host parameter has an index of 1, not 0. 3565 ** 3566 ** ^If the value N is out of range or if the N-th parameter is 3567 ** nameless, then NULL is returned. ^The returned string is 3568 ** always in UTF-8 encoding even if the named parameter was 3569 ** originally specified as UTF-16 in [sqlite3_prepare16()] or 3570 ** [sqlite3_prepare16_v2()]. 3571 ** 3572 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3573 ** [sqlite3_bind_parameter_count()], and 3574 ** [sqlite3_bind_parameter_index()]. 3575 */ 3576 SQLITE_API const char *SQLITE_STDCALL sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3577 3578 /* 3579 ** CAPI3REF: Index Of A Parameter With A Given Name 3580 ** 3581 ** ^Return the index of an SQL parameter given its name. ^The 3582 ** index value returned is suitable for use as the second 3583 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3584 ** is returned if no matching parameter is found. ^The parameter 3585 ** name must be given in UTF-8 even if the original statement 3586 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3587 ** 3588 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3589 ** [sqlite3_bind_parameter_count()], and 3590 ** [sqlite3_bind_parameter_index()]. 3591 */ 3592 SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3593 3594 /* 3595 ** CAPI3REF: Reset All Bindings On A Prepared Statement 3596 ** 3597 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3598 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3599 ** ^Use this routine to reset all host parameters to NULL. 3600 */ 3601 SQLITE_API int SQLITE_STDCALL sqlite3_clear_bindings(sqlite3_stmt*); 3602 3603 /* 3604 ** CAPI3REF: Number Of Columns In A Result Set 3605 ** 3606 ** ^Return the number of columns in the result set returned by the 3607 ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3608 ** statement that does not return data (for example an [UPDATE]). 3609 ** 3610 ** See also: [sqlite3_data_count()] 3611 */ 3612 SQLITE_API int SQLITE_STDCALL sqlite3_column_count(sqlite3_stmt *pStmt); 3613 3614 /* 3615 ** CAPI3REF: Column Names In A Result Set 3616 ** 3617 ** ^These routines return the name assigned to a particular column 3618 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3619 ** interface returns a pointer to a zero-terminated UTF-8 string 3620 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 3621 ** UTF-16 string. ^The first parameter is the [prepared statement] 3622 ** that implements the [SELECT] statement. ^The second parameter is the 3623 ** column number. ^The leftmost column is number 0. 3624 ** 3625 ** ^The returned string pointer is valid until either the [prepared statement] 3626 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3627 ** reprepared by the first call to [sqlite3_step()] for a particular run 3628 ** or until the next call to 3629 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3630 ** 3631 ** ^If sqlite3_malloc() fails during the processing of either routine 3632 ** (for example during a conversion from UTF-8 to UTF-16) then a 3633 ** NULL pointer is returned. 3634 ** 3635 ** ^The name of a result column is the value of the "AS" clause for 3636 ** that column, if there is an AS clause. If there is no AS clause 3637 ** then the name of the column is unspecified and may change from 3638 ** one release of SQLite to the next. 3639 */ 3640 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_name(sqlite3_stmt*, int N); 3641 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_name16(sqlite3_stmt*, int N); 3642 3643 /* 3644 ** CAPI3REF: Source Of Data In A Query Result 3645 ** 3646 ** ^These routines provide a means to determine the database, table, and 3647 ** table column that is the origin of a particular result column in 3648 ** [SELECT] statement. 3649 ** ^The name of the database or table or column can be returned as 3650 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3651 ** the database name, the _table_ routines return the table name, and 3652 ** the origin_ routines return the column name. 3653 ** ^The returned string is valid until the [prepared statement] is destroyed 3654 ** using [sqlite3_finalize()] or until the statement is automatically 3655 ** reprepared by the first call to [sqlite3_step()] for a particular run 3656 ** or until the same information is requested 3657 ** again in a different encoding. 3658 ** 3659 ** ^The names returned are the original un-aliased names of the 3660 ** database, table, and column. 3661 ** 3662 ** ^The first argument to these interfaces is a [prepared statement]. 3663 ** ^These functions return information about the Nth result column returned by 3664 ** the statement, where N is the second function argument. 3665 ** ^The left-most column is column 0 for these routines. 3666 ** 3667 ** ^If the Nth column returned by the statement is an expression or 3668 ** subquery and is not a column value, then all of these functions return 3669 ** NULL. ^These routine might also return NULL if a memory allocation error 3670 ** occurs. ^Otherwise, they return the name of the attached database, table, 3671 ** or column that query result column was extracted from. 3672 ** 3673 ** ^As with all other SQLite APIs, those whose names end with "16" return 3674 ** UTF-16 encoded strings and the other functions return UTF-8. 3675 ** 3676 ** ^These APIs are only available if the library was compiled with the 3677 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3678 ** 3679 ** If two or more threads call one or more of these routines against the same 3680 ** prepared statement and column at the same time then the results are 3681 ** undefined. 3682 ** 3683 ** If two or more threads call one or more 3684 ** [sqlite3_column_database_name | column metadata interfaces] 3685 ** for the same [prepared statement] and result column 3686 ** at the same time then the results are undefined. 3687 */ 3688 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_database_name(sqlite3_stmt*,int); 3689 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_database_name16(sqlite3_stmt*,int); 3690 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_table_name(sqlite3_stmt*,int); 3691 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_table_name16(sqlite3_stmt*,int); 3692 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_origin_name(sqlite3_stmt*,int); 3693 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_origin_name16(sqlite3_stmt*,int); 3694 3695 /* 3696 ** CAPI3REF: Declared Datatype Of A Query Result 3697 ** 3698 ** ^(The first parameter is a [prepared statement]. 3699 ** If this statement is a [SELECT] statement and the Nth column of the 3700 ** returned result set of that [SELECT] is a table column (not an 3701 ** expression or subquery) then the declared type of the table 3702 ** column is returned.)^ ^If the Nth column of the result set is an 3703 ** expression or subquery, then a NULL pointer is returned. 3704 ** ^The returned string is always UTF-8 encoded. 3705 ** 3706 ** ^(For example, given the database schema: 3707 ** 3708 ** CREATE TABLE t1(c1 VARIANT); 3709 ** 3710 ** and the following statement to be compiled: 3711 ** 3712 ** SELECT c1 + 1, c1 FROM t1; 3713 ** 3714 ** this routine would return the string "VARIANT" for the second result 3715 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3716 ** 3717 ** ^SQLite uses dynamic run-time typing. ^So just because a column 3718 ** is declared to contain a particular type does not mean that the 3719 ** data stored in that column is of the declared type. SQLite is 3720 ** strongly typed, but the typing is dynamic not static. ^Type 3721 ** is associated with individual values, not with the containers 3722 ** used to hold those values. 3723 */ 3724 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_decltype(sqlite3_stmt*,int); 3725 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_decltype16(sqlite3_stmt*,int); 3726 3727 /* 3728 ** CAPI3REF: Evaluate An SQL Statement 3729 ** 3730 ** After a [prepared statement] has been prepared using either 3731 ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3732 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3733 ** must be called one or more times to evaluate the statement. 3734 ** 3735 ** The details of the behavior of the sqlite3_step() interface depend 3736 ** on whether the statement was prepared using the newer "v2" interface 3737 ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3738 ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3739 ** new "v2" interface is recommended for new applications but the legacy 3740 ** interface will continue to be supported. 3741 ** 3742 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 3743 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3744 ** ^With the "v2" interface, any of the other [result codes] or 3745 ** [extended result codes] might be returned as well. 3746 ** 3747 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 3748 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 3749 ** or occurs outside of an explicit transaction, then you can retry the 3750 ** statement. If the statement is not a [COMMIT] and occurs within an 3751 ** explicit transaction then you should rollback the transaction before 3752 ** continuing. 3753 ** 3754 ** ^[SQLITE_DONE] means that the statement has finished executing 3755 ** successfully. sqlite3_step() should not be called again on this virtual 3756 ** machine without first calling [sqlite3_reset()] to reset the virtual 3757 ** machine back to its initial state. 3758 ** 3759 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 3760 ** is returned each time a new row of data is ready for processing by the 3761 ** caller. The values may be accessed using the [column access functions]. 3762 ** sqlite3_step() is called again to retrieve the next row of data. 3763 ** 3764 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 3765 ** violation) has occurred. sqlite3_step() should not be called again on 3766 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 3767 ** ^With the legacy interface, a more specific error code (for example, 3768 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3769 ** can be obtained by calling [sqlite3_reset()] on the 3770 ** [prepared statement]. ^In the "v2" interface, 3771 ** the more specific error code is returned directly by sqlite3_step(). 3772 ** 3773 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3774 ** Perhaps it was called on a [prepared statement] that has 3775 ** already been [sqlite3_finalize | finalized] or on one that had 3776 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3777 ** be the case that the same database connection is being used by two or 3778 ** more threads at the same moment in time. 3779 ** 3780 ** For all versions of SQLite up to and including 3.6.23.1, a call to 3781 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 3782 ** other than [SQLITE_ROW] before any subsequent invocation of 3783 ** sqlite3_step(). Failure to reset the prepared statement using 3784 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 3785 ** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 3786 ** calling [sqlite3_reset()] automatically in this circumstance rather 3787 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 3788 ** break because any application that ever receives an SQLITE_MISUSE error 3789 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 3790 ** can be used to restore the legacy behavior. 3791 ** 3792 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 3793 ** API always returns a generic error code, [SQLITE_ERROR], following any 3794 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 3795 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 3796 ** specific [error codes] that better describes the error. 3797 ** We admit that this is a goofy design. The problem has been fixed 3798 ** with the "v2" interface. If you prepare all of your SQL statements 3799 ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3800 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 3801 ** then the more specific [error codes] are returned directly 3802 ** by sqlite3_step(). The use of the "v2" interface is recommended. 3803 */ 3804 SQLITE_API int SQLITE_STDCALL sqlite3_step(sqlite3_stmt*); 3805 3806 /* 3807 ** CAPI3REF: Number of columns in a result set 3808 ** 3809 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 3810 ** current row of the result set of [prepared statement] P. 3811 ** ^If prepared statement P does not have results ready to return 3812 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 3813 ** interfaces) then sqlite3_data_count(P) returns 0. 3814 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 3815 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 3816 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 3817 ** will return non-zero if previous call to [sqlite3_step](P) returned 3818 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 3819 ** where it always returns zero since each step of that multi-step 3820 ** pragma returns 0 columns of data. 3821 ** 3822 ** See also: [sqlite3_column_count()] 3823 */ 3824 SQLITE_API int SQLITE_STDCALL sqlite3_data_count(sqlite3_stmt *pStmt); 3825 3826 /* 3827 ** CAPI3REF: Fundamental Datatypes 3828 ** KEYWORDS: SQLITE_TEXT 3829 ** 3830 ** ^(Every value in SQLite has one of five fundamental datatypes: 3831 ** 3832 ** <ul> 3833 ** <li> 64-bit signed integer 3834 ** <li> 64-bit IEEE floating point number 3835 ** <li> string 3836 ** <li> BLOB 3837 ** <li> NULL 3838 ** </ul>)^ 3839 ** 3840 ** These constants are codes for each of those types. 3841 ** 3842 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3843 ** for a completely different meaning. Software that links against both 3844 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 3845 ** SQLITE_TEXT. 3846 */ 3847 #define SQLITE_INTEGER 1 3848 #define SQLITE_FLOAT 2 3849 #define SQLITE_BLOB 4 3850 #define SQLITE_NULL 5 3851 #ifdef SQLITE_TEXT 3852 # undef SQLITE_TEXT 3853 #else 3854 # define SQLITE_TEXT 3 3855 #endif 3856 #define SQLITE3_TEXT 3 3857 3858 /* 3859 ** CAPI3REF: Result Values From A Query 3860 ** KEYWORDS: {column access functions} 3861 ** 3862 ** These routines form the "result set" interface. 3863 ** 3864 ** ^These routines return information about a single column of the current 3865 ** result row of a query. ^In every case the first argument is a pointer 3866 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 3867 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 3868 ** and the second argument is the index of the column for which information 3869 ** should be returned. ^The leftmost column of the result set has the index 0. 3870 ** ^The number of columns in the result can be determined using 3871 ** [sqlite3_column_count()]. 3872 ** 3873 ** If the SQL statement does not currently point to a valid row, or if the 3874 ** column index is out of range, the result is undefined. 3875 ** These routines may only be called when the most recent call to 3876 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3877 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 3878 ** If any of these routines are called after [sqlite3_reset()] or 3879 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3880 ** something other than [SQLITE_ROW], the results are undefined. 3881 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3882 ** are called from a different thread while any of these routines 3883 ** are pending, then the results are undefined. 3884 ** 3885 ** ^The sqlite3_column_type() routine returns the 3886 ** [SQLITE_INTEGER | datatype code] for the initial data type 3887 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 3888 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3889 ** returned by sqlite3_column_type() is only meaningful if no type 3890 ** conversions have occurred as described below. After a type conversion, 3891 ** the value returned by sqlite3_column_type() is undefined. Future 3892 ** versions of SQLite may change the behavior of sqlite3_column_type() 3893 ** following a type conversion. 3894 ** 3895 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3896 ** routine returns the number of bytes in that BLOB or string. 3897 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3898 ** the string to UTF-8 and then returns the number of bytes. 3899 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 3900 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 3901 ** the number of bytes in that string. 3902 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 3903 ** 3904 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 3905 ** routine returns the number of bytes in that BLOB or string. 3906 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 3907 ** the string to UTF-16 and then returns the number of bytes. 3908 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 3909 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 3910 ** the number of bytes in that string. 3911 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 3912 ** 3913 ** ^The values returned by [sqlite3_column_bytes()] and 3914 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 3915 ** of the string. ^For clarity: the values returned by 3916 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 3917 ** bytes in the string, not the number of characters. 3918 ** 3919 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 3920 ** even empty strings, are always zero-terminated. ^The return 3921 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 3922 ** 3923 ** ^The object returned by [sqlite3_column_value()] is an 3924 ** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 3925 ** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 3926 ** If the [unprotected sqlite3_value] object returned by 3927 ** [sqlite3_column_value()] is used in any other way, including calls 3928 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 3929 ** or [sqlite3_value_bytes()], then the behavior is undefined. 3930 ** 3931 ** These routines attempt to convert the value where appropriate. ^For 3932 ** example, if the internal representation is FLOAT and a text result 3933 ** is requested, [sqlite3_snprintf()] is used internally to perform the 3934 ** conversion automatically. ^(The following table details the conversions 3935 ** that are applied: 3936 ** 3937 ** <blockquote> 3938 ** <table border="1"> 3939 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 3940 ** 3941 ** <tr><td> NULL <td> INTEGER <td> Result is 0 3942 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 3943 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 3944 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 3945 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 3946 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 3947 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 3948 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 3949 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 3950 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 3951 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 3952 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 3953 ** <tr><td> TEXT <td> BLOB <td> No change 3954 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 3955 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 3956 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 3957 ** </table> 3958 ** </blockquote>)^ 3959 ** 3960 ** The table above makes reference to standard C library functions atoi() 3961 ** and atof(). SQLite does not really use these functions. It has its 3962 ** own equivalent internal routines. The atoi() and atof() names are 3963 ** used in the table for brevity and because they are familiar to most 3964 ** C programmers. 3965 ** 3966 ** Note that when type conversions occur, pointers returned by prior 3967 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 3968 ** sqlite3_column_text16() may be invalidated. 3969 ** Type conversions and pointer invalidations might occur 3970 ** in the following cases: 3971 ** 3972 ** <ul> 3973 ** <li> The initial content is a BLOB and sqlite3_column_text() or 3974 ** sqlite3_column_text16() is called. A zero-terminator might 3975 ** need to be added to the string.</li> 3976 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 3977 ** sqlite3_column_text16() is called. The content must be converted 3978 ** to UTF-16.</li> 3979 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 3980 ** sqlite3_column_text() is called. The content must be converted 3981 ** to UTF-8.</li> 3982 ** </ul> 3983 ** 3984 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 3985 ** not invalidate a prior pointer, though of course the content of the buffer 3986 ** that the prior pointer references will have been modified. Other kinds 3987 ** of conversion are done in place when it is possible, but sometimes they 3988 ** are not possible and in those cases prior pointers are invalidated. 3989 ** 3990 ** The safest and easiest to remember policy is to invoke these routines 3991 ** in one of the following ways: 3992 ** 3993 ** <ul> 3994 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 3995 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 3996 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 3997 ** </ul> 3998 ** 3999 ** In other words, you should call sqlite3_column_text(), 4000 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4001 ** into the desired format, then invoke sqlite3_column_bytes() or 4002 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4003 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4004 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4005 ** with calls to sqlite3_column_bytes(). 4006 ** 4007 ** ^The pointers returned are valid until a type conversion occurs as 4008 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4009 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4010 ** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned 4011 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4012 ** [sqlite3_free()]. 4013 ** 4014 ** ^(If a memory allocation error occurs during the evaluation of any 4015 ** of these routines, a default value is returned. The default value 4016 ** is either the integer 0, the floating point number 0.0, or a NULL 4017 ** pointer. Subsequent calls to [sqlite3_errcode()] will return 4018 ** [SQLITE_NOMEM].)^ 4019 */ 4020 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_blob(sqlite3_stmt*, int iCol); 4021 SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4022 SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4023 SQLITE_API double SQLITE_STDCALL sqlite3_column_double(sqlite3_stmt*, int iCol); 4024 SQLITE_API int SQLITE_STDCALL sqlite3_column_int(sqlite3_stmt*, int iCol); 4025 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_column_int64(sqlite3_stmt*, int iCol); 4026 SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_column_text(sqlite3_stmt*, int iCol); 4027 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_text16(sqlite3_stmt*, int iCol); 4028 SQLITE_API int SQLITE_STDCALL sqlite3_column_type(sqlite3_stmt*, int iCol); 4029 SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_column_value(sqlite3_stmt*, int iCol); 4030 4031 /* 4032 ** CAPI3REF: Destroy A Prepared Statement Object 4033 ** 4034 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4035 ** ^If the most recent evaluation of the statement encountered no errors 4036 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 4037 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4038 ** sqlite3_finalize(S) returns the appropriate [error code] or 4039 ** [extended error code]. 4040 ** 4041 ** ^The sqlite3_finalize(S) routine can be called at any point during 4042 ** the life cycle of [prepared statement] S: 4043 ** before statement S is ever evaluated, after 4044 ** one or more calls to [sqlite3_reset()], or after any call 4045 ** to [sqlite3_step()] regardless of whether or not the statement has 4046 ** completed execution. 4047 ** 4048 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4049 ** 4050 ** The application must finalize every [prepared statement] in order to avoid 4051 ** resource leaks. It is a grievous error for the application to try to use 4052 ** a prepared statement after it has been finalized. Any use of a prepared 4053 ** statement after it has been finalized can result in undefined and 4054 ** undesirable behavior such as segfaults and heap corruption. 4055 */ 4056 SQLITE_API int SQLITE_STDCALL sqlite3_finalize(sqlite3_stmt *pStmt); 4057 4058 /* 4059 ** CAPI3REF: Reset A Prepared Statement Object 4060 ** 4061 ** The sqlite3_reset() function is called to reset a [prepared statement] 4062 ** object back to its initial state, ready to be re-executed. 4063 ** ^Any SQL statement variables that had values bound to them using 4064 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4065 ** Use [sqlite3_clear_bindings()] to reset the bindings. 4066 ** 4067 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4068 ** back to the beginning of its program. 4069 ** 4070 ** ^If the most recent call to [sqlite3_step(S)] for the 4071 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4072 ** or if [sqlite3_step(S)] has never before been called on S, 4073 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4074 ** 4075 ** ^If the most recent call to [sqlite3_step(S)] for the 4076 ** [prepared statement] S indicated an error, then 4077 ** [sqlite3_reset(S)] returns an appropriate [error code]. 4078 ** 4079 ** ^The [sqlite3_reset(S)] interface does not change the values 4080 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4081 */ 4082 SQLITE_API int SQLITE_STDCALL sqlite3_reset(sqlite3_stmt *pStmt); 4083 4084 /* 4085 ** CAPI3REF: Create Or Redefine SQL Functions 4086 ** KEYWORDS: {function creation routines} 4087 ** KEYWORDS: {application-defined SQL function} 4088 ** KEYWORDS: {application-defined SQL functions} 4089 ** 4090 ** ^These functions (collectively known as "function creation routines") 4091 ** are used to add SQL functions or aggregates or to redefine the behavior 4092 ** of existing SQL functions or aggregates. The only differences between 4093 ** these routines are the text encoding expected for 4094 ** the second parameter (the name of the function being created) 4095 ** and the presence or absence of a destructor callback for 4096 ** the application data pointer. 4097 ** 4098 ** ^The first parameter is the [database connection] to which the SQL 4099 ** function is to be added. ^If an application uses more than one database 4100 ** connection then application-defined SQL functions must be added 4101 ** to each database connection separately. 4102 ** 4103 ** ^The second parameter is the name of the SQL function to be created or 4104 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4105 ** representation, exclusive of the zero-terminator. ^Note that the name 4106 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4107 ** ^Any attempt to create a function with a longer name 4108 ** will result in [SQLITE_MISUSE] being returned. 4109 ** 4110 ** ^The third parameter (nArg) 4111 ** is the number of arguments that the SQL function or 4112 ** aggregate takes. ^If this parameter is -1, then the SQL function or 4113 ** aggregate may take any number of arguments between 0 and the limit 4114 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4115 ** parameter is less than -1 or greater than 127 then the behavior is 4116 ** undefined. 4117 ** 4118 ** ^The fourth parameter, eTextRep, specifies what 4119 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4120 ** its parameters. The application should set this parameter to 4121 ** [SQLITE_UTF16LE] if the function implementation invokes 4122 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4123 ** implementation invokes [sqlite3_value_text16be()] on an input, or 4124 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4125 ** otherwise. ^The same SQL function may be registered multiple times using 4126 ** different preferred text encodings, with different implementations for 4127 ** each encoding. 4128 ** ^When multiple implementations of the same function are available, SQLite 4129 ** will pick the one that involves the least amount of data conversion. 4130 ** 4131 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4132 ** to signal that the function will always return the same result given 4133 ** the same inputs within a single SQL statement. Most SQL functions are 4134 ** deterministic. The built-in [random()] SQL function is an example of a 4135 ** function that is not deterministic. The SQLite query planner is able to 4136 ** perform additional optimizations on deterministic functions, so use 4137 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4138 ** 4139 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4140 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 4141 ** 4142 ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4143 ** pointers to C-language functions that implement the SQL function or 4144 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4145 ** callback only; NULL pointers must be passed as the xStep and xFinal 4146 ** parameters. ^An aggregate SQL function requires an implementation of xStep 4147 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4148 ** SQL function or aggregate, pass NULL pointers for all three function 4149 ** callbacks. 4150 ** 4151 ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4152 ** then it is destructor for the application data pointer. 4153 ** The destructor is invoked when the function is deleted, either by being 4154 ** overloaded or when the database connection closes.)^ 4155 ** ^The destructor is also invoked if the call to 4156 ** sqlite3_create_function_v2() fails. 4157 ** ^When the destructor callback of the tenth parameter is invoked, it 4158 ** is passed a single argument which is a copy of the application data 4159 ** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4160 ** 4161 ** ^It is permitted to register multiple implementations of the same 4162 ** functions with the same name but with either differing numbers of 4163 ** arguments or differing preferred text encodings. ^SQLite will use 4164 ** the implementation that most closely matches the way in which the 4165 ** SQL function is used. ^A function implementation with a non-negative 4166 ** nArg parameter is a better match than a function implementation with 4167 ** a negative nArg. ^A function where the preferred text encoding 4168 ** matches the database encoding is a better 4169 ** match than a function where the encoding is different. 4170 ** ^A function where the encoding difference is between UTF16le and UTF16be 4171 ** is a closer match than a function where the encoding difference is 4172 ** between UTF8 and UTF16. 4173 ** 4174 ** ^Built-in functions may be overloaded by new application-defined functions. 4175 ** 4176 ** ^An application-defined function is permitted to call other 4177 ** SQLite interfaces. However, such calls must not 4178 ** close the database connection nor finalize or reset the prepared 4179 ** statement in which the function is running. 4180 */ 4181 SQLITE_API int SQLITE_STDCALL sqlite3_create_function( 4182 sqlite3 *db, 4183 const char *zFunctionName, 4184 int nArg, 4185 int eTextRep, 4186 void *pApp, 4187 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4188 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4189 void (*xFinal)(sqlite3_context*) 4190 ); 4191 SQLITE_API int SQLITE_STDCALL sqlite3_create_function16( 4192 sqlite3 *db, 4193 const void *zFunctionName, 4194 int nArg, 4195 int eTextRep, 4196 void *pApp, 4197 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4198 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4199 void (*xFinal)(sqlite3_context*) 4200 ); 4201 SQLITE_API int SQLITE_STDCALL sqlite3_create_function_v2( 4202 sqlite3 *db, 4203 const char *zFunctionName, 4204 int nArg, 4205 int eTextRep, 4206 void *pApp, 4207 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4208 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4209 void (*xFinal)(sqlite3_context*), 4210 void(*xDestroy)(void*) 4211 ); 4212 4213 /* 4214 ** CAPI3REF: Text Encodings 4215 ** 4216 ** These constant define integer codes that represent the various 4217 ** text encodings supported by SQLite. 4218 */ 4219 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4220 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4221 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4222 #define SQLITE_UTF16 4 /* Use native byte order */ 4223 #define SQLITE_ANY 5 /* Deprecated */ 4224 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4225 4226 /* 4227 ** CAPI3REF: Function Flags 4228 ** 4229 ** These constants may be ORed together with the 4230 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4231 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4232 ** [sqlite3_create_function_v2()]. 4233 */ 4234 #define SQLITE_DETERMINISTIC 0x800 4235 4236 /* 4237 ** CAPI3REF: Deprecated Functions 4238 ** DEPRECATED 4239 ** 4240 ** These functions are [deprecated]. In order to maintain 4241 ** backwards compatibility with older code, these functions continue 4242 ** to be supported. However, new applications should avoid 4243 ** the use of these functions. To encourage programmers to avoid 4244 ** these functions, we will not explain what they do. 4245 */ 4246 #ifndef SQLITE_OMIT_DEPRECATED 4247 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_aggregate_count(sqlite3_context*); 4248 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_expired(sqlite3_stmt*); 4249 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4250 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_global_recover(void); 4251 SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_thread_cleanup(void); 4252 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4253 void*,sqlite3_int64); 4254 #endif 4255 4256 /* 4257 ** CAPI3REF: Obtaining SQL Function Parameter Values 4258 ** 4259 ** The C-language implementation of SQL functions and aggregates uses 4260 ** this set of interface routines to access the parameter values on 4261 ** the function or aggregate. 4262 ** 4263 ** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4264 ** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4265 ** define callbacks that implement the SQL functions and aggregates. 4266 ** The 3rd parameter to these callbacks is an array of pointers to 4267 ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4268 ** each parameter to the SQL function. These routines are used to 4269 ** extract values from the [sqlite3_value] objects. 4270 ** 4271 ** These routines work only with [protected sqlite3_value] objects. 4272 ** Any attempt to use these routines on an [unprotected sqlite3_value] 4273 ** object results in undefined behavior. 4274 ** 4275 ** ^These routines work just like the corresponding [column access functions] 4276 ** except that these routines take a single [protected sqlite3_value] object 4277 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4278 ** 4279 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4280 ** in the native byte-order of the host machine. ^The 4281 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4282 ** extract UTF-16 strings as big-endian and little-endian respectively. 4283 ** 4284 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 4285 ** numeric affinity to the value. This means that an attempt is 4286 ** made to convert the value to an integer or floating point. If 4287 ** such a conversion is possible without loss of information (in other 4288 ** words, if the value is a string that looks like a number) 4289 ** then the conversion is performed. Otherwise no conversion occurs. 4290 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4291 ** 4292 ** Please pay particular attention to the fact that the pointer returned 4293 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4294 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4295 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4296 ** or [sqlite3_value_text16()]. 4297 ** 4298 ** These routines must be called from the same thread as 4299 ** the SQL function that supplied the [sqlite3_value*] parameters. 4300 */ 4301 SQLITE_API const void *SQLITE_STDCALL sqlite3_value_blob(sqlite3_value*); 4302 SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes(sqlite3_value*); 4303 SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes16(sqlite3_value*); 4304 SQLITE_API double SQLITE_STDCALL sqlite3_value_double(sqlite3_value*); 4305 SQLITE_API int SQLITE_STDCALL sqlite3_value_int(sqlite3_value*); 4306 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_value_int64(sqlite3_value*); 4307 SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_value_text(sqlite3_value*); 4308 SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16(sqlite3_value*); 4309 SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16le(sqlite3_value*); 4310 SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16be(sqlite3_value*); 4311 SQLITE_API int SQLITE_STDCALL sqlite3_value_type(sqlite3_value*); 4312 SQLITE_API int SQLITE_STDCALL sqlite3_value_numeric_type(sqlite3_value*); 4313 4314 /* 4315 ** CAPI3REF: Obtain Aggregate Function Context 4316 ** 4317 ** Implementations of aggregate SQL functions use this 4318 ** routine to allocate memory for storing their state. 4319 ** 4320 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4321 ** for a particular aggregate function, SQLite 4322 ** allocates N of memory, zeroes out that memory, and returns a pointer 4323 ** to the new memory. ^On second and subsequent calls to 4324 ** sqlite3_aggregate_context() for the same aggregate function instance, 4325 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 4326 ** called once for each invocation of the xStep callback and then one 4327 ** last time when the xFinal callback is invoked. ^(When no rows match 4328 ** an aggregate query, the xStep() callback of the aggregate function 4329 ** implementation is never called and xFinal() is called exactly once. 4330 ** In those cases, sqlite3_aggregate_context() might be called for the 4331 ** first time from within xFinal().)^ 4332 ** 4333 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4334 ** when first called if N is less than or equal to zero or if a memory 4335 ** allocate error occurs. 4336 ** 4337 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4338 ** determined by the N parameter on first successful call. Changing the 4339 ** value of N in subsequent call to sqlite3_aggregate_context() within 4340 ** the same aggregate function instance will not resize the memory 4341 ** allocation.)^ Within the xFinal callback, it is customary to set 4342 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4343 ** pointless memory allocations occur. 4344 ** 4345 ** ^SQLite automatically frees the memory allocated by 4346 ** sqlite3_aggregate_context() when the aggregate query concludes. 4347 ** 4348 ** The first parameter must be a copy of the 4349 ** [sqlite3_context | SQL function context] that is the first parameter 4350 ** to the xStep or xFinal callback routine that implements the aggregate 4351 ** function. 4352 ** 4353 ** This routine must be called from the same thread in which 4354 ** the aggregate SQL function is running. 4355 */ 4356 SQLITE_API void *SQLITE_STDCALL sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4357 4358 /* 4359 ** CAPI3REF: User Data For Functions 4360 ** 4361 ** ^The sqlite3_user_data() interface returns a copy of 4362 ** the pointer that was the pUserData parameter (the 5th parameter) 4363 ** of the [sqlite3_create_function()] 4364 ** and [sqlite3_create_function16()] routines that originally 4365 ** registered the application defined function. 4366 ** 4367 ** This routine must be called from the same thread in which 4368 ** the application-defined function is running. 4369 */ 4370 SQLITE_API void *SQLITE_STDCALL sqlite3_user_data(sqlite3_context*); 4371 4372 /* 4373 ** CAPI3REF: Database Connection For Functions 4374 ** 4375 ** ^The sqlite3_context_db_handle() interface returns a copy of 4376 ** the pointer to the [database connection] (the 1st parameter) 4377 ** of the [sqlite3_create_function()] 4378 ** and [sqlite3_create_function16()] routines that originally 4379 ** registered the application defined function. 4380 */ 4381 SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_context_db_handle(sqlite3_context*); 4382 4383 /* 4384 ** CAPI3REF: Function Auxiliary Data 4385 ** 4386 ** These functions may be used by (non-aggregate) SQL functions to 4387 ** associate metadata with argument values. If the same value is passed to 4388 ** multiple invocations of the same SQL function during query execution, under 4389 ** some circumstances the associated metadata may be preserved. An example 4390 ** of where this might be useful is in a regular-expression matching 4391 ** function. The compiled version of the regular expression can be stored as 4392 ** metadata associated with the pattern string. 4393 ** Then as long as the pattern string remains the same, 4394 ** the compiled regular expression can be reused on multiple 4395 ** invocations of the same function. 4396 ** 4397 ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4398 ** associated by the sqlite3_set_auxdata() function with the Nth argument 4399 ** value to the application-defined function. ^If there is no metadata 4400 ** associated with the function argument, this sqlite3_get_auxdata() interface 4401 ** returns a NULL pointer. 4402 ** 4403 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4404 ** argument of the application-defined function. ^Subsequent 4405 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4406 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4407 ** NULL if the metadata has been discarded. 4408 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4409 ** SQLite will invoke the destructor function X with parameter P exactly 4410 ** once, when the metadata is discarded. 4411 ** SQLite is free to discard the metadata at any time, including: <ul> 4412 ** <li> when the corresponding function parameter changes, or 4413 ** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4414 ** SQL statement, or 4415 ** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or 4416 ** <li> during the original sqlite3_set_auxdata() call when a memory 4417 ** allocation error occurs. </ul>)^ 4418 ** 4419 ** Note the last bullet in particular. The destructor X in 4420 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4421 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4422 ** should be called near the end of the function implementation and the 4423 ** function implementation should not make any use of P after 4424 ** sqlite3_set_auxdata() has been called. 4425 ** 4426 ** ^(In practice, metadata is preserved between function calls for 4427 ** function parameters that are compile-time constants, including literal 4428 ** values and [parameters] and expressions composed from the same.)^ 4429 ** 4430 ** These routines must be called from the same thread in which 4431 ** the SQL function is running. 4432 */ 4433 SQLITE_API void *SQLITE_STDCALL sqlite3_get_auxdata(sqlite3_context*, int N); 4434 SQLITE_API void SQLITE_STDCALL sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4435 4436 4437 /* 4438 ** CAPI3REF: Constants Defining Special Destructor Behavior 4439 ** 4440 ** These are special values for the destructor that is passed in as the 4441 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4442 ** argument is SQLITE_STATIC, it means that the content pointer is constant 4443 ** and will never change. It does not need to be destroyed. ^The 4444 ** SQLITE_TRANSIENT value means that the content will likely change in 4445 ** the near future and that SQLite should make its own private copy of 4446 ** the content before returning. 4447 ** 4448 ** The typedef is necessary to work around problems in certain 4449 ** C++ compilers. 4450 */ 4451 typedef void (*sqlite3_destructor_type)(void*); 4452 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 4453 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4454 4455 /* 4456 ** CAPI3REF: Setting The Result Of An SQL Function 4457 ** 4458 ** These routines are used by the xFunc or xFinal callbacks that 4459 ** implement SQL functions and aggregates. See 4460 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 4461 ** for additional information. 4462 ** 4463 ** These functions work very much like the [parameter binding] family of 4464 ** functions used to bind values to host parameters in prepared statements. 4465 ** Refer to the [SQL parameter] documentation for additional information. 4466 ** 4467 ** ^The sqlite3_result_blob() interface sets the result from 4468 ** an application-defined function to be the BLOB whose content is pointed 4469 ** to by the second parameter and which is N bytes long where N is the 4470 ** third parameter. 4471 ** 4472 ** ^The sqlite3_result_zeroblob() interfaces set the result of 4473 ** the application-defined function to be a BLOB containing all zero 4474 ** bytes and N bytes in size, where N is the value of the 2nd parameter. 4475 ** 4476 ** ^The sqlite3_result_double() interface sets the result from 4477 ** an application-defined function to be a floating point value specified 4478 ** by its 2nd argument. 4479 ** 4480 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4481 ** cause the implemented SQL function to throw an exception. 4482 ** ^SQLite uses the string pointed to by the 4483 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4484 ** as the text of an error message. ^SQLite interprets the error 4485 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 4486 ** interprets the string from sqlite3_result_error16() as UTF-16 in native 4487 ** byte order. ^If the third parameter to sqlite3_result_error() 4488 ** or sqlite3_result_error16() is negative then SQLite takes as the error 4489 ** message all text up through the first zero character. 4490 ** ^If the third parameter to sqlite3_result_error() or 4491 ** sqlite3_result_error16() is non-negative then SQLite takes that many 4492 ** bytes (not characters) from the 2nd parameter as the error message. 4493 ** ^The sqlite3_result_error() and sqlite3_result_error16() 4494 ** routines make a private copy of the error message text before 4495 ** they return. Hence, the calling function can deallocate or 4496 ** modify the text after they return without harm. 4497 ** ^The sqlite3_result_error_code() function changes the error code 4498 ** returned by SQLite as a result of an error in a function. ^By default, 4499 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4500 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4501 ** 4502 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4503 ** error indicating that a string or BLOB is too long to represent. 4504 ** 4505 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4506 ** error indicating that a memory allocation failed. 4507 ** 4508 ** ^The sqlite3_result_int() interface sets the return value 4509 ** of the application-defined function to be the 32-bit signed integer 4510 ** value given in the 2nd argument. 4511 ** ^The sqlite3_result_int64() interface sets the return value 4512 ** of the application-defined function to be the 64-bit signed integer 4513 ** value given in the 2nd argument. 4514 ** 4515 ** ^The sqlite3_result_null() interface sets the return value 4516 ** of the application-defined function to be NULL. 4517 ** 4518 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 4519 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4520 ** set the return value of the application-defined function to be 4521 ** a text string which is represented as UTF-8, UTF-16 native byte order, 4522 ** UTF-16 little endian, or UTF-16 big endian, respectively. 4523 ** ^The sqlite3_result_text64() interface sets the return value of an 4524 ** application-defined function to be a text string in an encoding 4525 ** specified by the fifth (and last) parameter, which must be one 4526 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 4527 ** ^SQLite takes the text result from the application from 4528 ** the 2nd parameter of the sqlite3_result_text* interfaces. 4529 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4530 ** is negative, then SQLite takes result text from the 2nd parameter 4531 ** through the first zero character. 4532 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4533 ** is non-negative, then as many bytes (not characters) of the text 4534 ** pointed to by the 2nd parameter are taken as the application-defined 4535 ** function result. If the 3rd parameter is non-negative, then it 4536 ** must be the byte offset into the string where the NUL terminator would 4537 ** appear if the string where NUL terminated. If any NUL characters occur 4538 ** in the string at a byte offset that is less than the value of the 3rd 4539 ** parameter, then the resulting string will contain embedded NULs and the 4540 ** result of expressions operating on strings with embedded NULs is undefined. 4541 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 4542 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4543 ** function as the destructor on the text or BLOB result when it has 4544 ** finished using that result. 4545 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4546 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4547 ** assumes that the text or BLOB result is in constant space and does not 4548 ** copy the content of the parameter nor call a destructor on the content 4549 ** when it has finished using that result. 4550 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 4551 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4552 ** then SQLite makes a copy of the result into space obtained from 4553 ** from [sqlite3_malloc()] before it returns. 4554 ** 4555 ** ^The sqlite3_result_value() interface sets the result of 4556 ** the application-defined function to be a copy the 4557 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4558 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4559 ** so that the [sqlite3_value] specified in the parameter may change or 4560 ** be deallocated after sqlite3_result_value() returns without harm. 4561 ** ^A [protected sqlite3_value] object may always be used where an 4562 ** [unprotected sqlite3_value] object is required, so either 4563 ** kind of [sqlite3_value] object can be used with this interface. 4564 ** 4565 ** If these routines are called from within the different thread 4566 ** than the one containing the application-defined function that received 4567 ** the [sqlite3_context] pointer, the results are undefined. 4568 */ 4569 SQLITE_API void SQLITE_STDCALL sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4570 SQLITE_API void SQLITE_STDCALL sqlite3_result_blob64(sqlite3_context*,const void*, 4571 sqlite3_uint64,void(*)(void*)); 4572 SQLITE_API void SQLITE_STDCALL sqlite3_result_double(sqlite3_context*, double); 4573 SQLITE_API void SQLITE_STDCALL sqlite3_result_error(sqlite3_context*, const char*, int); 4574 SQLITE_API void SQLITE_STDCALL sqlite3_result_error16(sqlite3_context*, const void*, int); 4575 SQLITE_API void SQLITE_STDCALL sqlite3_result_error_toobig(sqlite3_context*); 4576 SQLITE_API void SQLITE_STDCALL sqlite3_result_error_nomem(sqlite3_context*); 4577 SQLITE_API void SQLITE_STDCALL sqlite3_result_error_code(sqlite3_context*, int); 4578 SQLITE_API void SQLITE_STDCALL sqlite3_result_int(sqlite3_context*, int); 4579 SQLITE_API void SQLITE_STDCALL sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4580 SQLITE_API void SQLITE_STDCALL sqlite3_result_null(sqlite3_context*); 4581 SQLITE_API void SQLITE_STDCALL sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4582 SQLITE_API void SQLITE_STDCALL sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 4583 void(*)(void*), unsigned char encoding); 4584 SQLITE_API void SQLITE_STDCALL sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4585 SQLITE_API void SQLITE_STDCALL sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4586 SQLITE_API void SQLITE_STDCALL sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4587 SQLITE_API void SQLITE_STDCALL sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4588 SQLITE_API void SQLITE_STDCALL sqlite3_result_zeroblob(sqlite3_context*, int n); 4589 4590 /* 4591 ** CAPI3REF: Define New Collating Sequences 4592 ** 4593 ** ^These functions add, remove, or modify a [collation] associated 4594 ** with the [database connection] specified as the first argument. 4595 ** 4596 ** ^The name of the collation is a UTF-8 string 4597 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4598 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4599 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4600 ** considered to be the same name. 4601 ** 4602 ** ^(The third argument (eTextRep) must be one of the constants: 4603 ** <ul> 4604 ** <li> [SQLITE_UTF8], 4605 ** <li> [SQLITE_UTF16LE], 4606 ** <li> [SQLITE_UTF16BE], 4607 ** <li> [SQLITE_UTF16], or 4608 ** <li> [SQLITE_UTF16_ALIGNED]. 4609 ** </ul>)^ 4610 ** ^The eTextRep argument determines the encoding of strings passed 4611 ** to the collating function callback, xCallback. 4612 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4613 ** force strings to be UTF16 with native byte order. 4614 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4615 ** on an even byte address. 4616 ** 4617 ** ^The fourth argument, pArg, is an application data pointer that is passed 4618 ** through as the first argument to the collating function callback. 4619 ** 4620 ** ^The fifth argument, xCallback, is a pointer to the collating function. 4621 ** ^Multiple collating functions can be registered using the same name but 4622 ** with different eTextRep parameters and SQLite will use whichever 4623 ** function requires the least amount of data transformation. 4624 ** ^If the xCallback argument is NULL then the collating function is 4625 ** deleted. ^When all collating functions having the same name are deleted, 4626 ** that collation is no longer usable. 4627 ** 4628 ** ^The collating function callback is invoked with a copy of the pArg 4629 ** application data pointer and with two strings in the encoding specified 4630 ** by the eTextRep argument. The collating function must return an 4631 ** integer that is negative, zero, or positive 4632 ** if the first string is less than, equal to, or greater than the second, 4633 ** respectively. A collating function must always return the same answer 4634 ** given the same inputs. If two or more collating functions are registered 4635 ** to the same collation name (using different eTextRep values) then all 4636 ** must give an equivalent answer when invoked with equivalent strings. 4637 ** The collating function must obey the following properties for all 4638 ** strings A, B, and C: 4639 ** 4640 ** <ol> 4641 ** <li> If A==B then B==A. 4642 ** <li> If A==B and B==C then A==C. 4643 ** <li> If A<B THEN B>A. 4644 ** <li> If A<B and B<C then A<C. 4645 ** </ol> 4646 ** 4647 ** If a collating function fails any of the above constraints and that 4648 ** collating function is registered and used, then the behavior of SQLite 4649 ** is undefined. 4650 ** 4651 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4652 ** with the addition that the xDestroy callback is invoked on pArg when 4653 ** the collating function is deleted. 4654 ** ^Collating functions are deleted when they are overridden by later 4655 ** calls to the collation creation functions or when the 4656 ** [database connection] is closed using [sqlite3_close()]. 4657 ** 4658 ** ^The xDestroy callback is <u>not</u> called if the 4659 ** sqlite3_create_collation_v2() function fails. Applications that invoke 4660 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4661 ** check the return code and dispose of the application data pointer 4662 ** themselves rather than expecting SQLite to deal with it for them. 4663 ** This is different from every other SQLite interface. The inconsistency 4664 ** is unfortunate but cannot be changed without breaking backwards 4665 ** compatibility. 4666 ** 4667 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4668 */ 4669 SQLITE_API int SQLITE_STDCALL sqlite3_create_collation( 4670 sqlite3*, 4671 const char *zName, 4672 int eTextRep, 4673 void *pArg, 4674 int(*xCompare)(void*,int,const void*,int,const void*) 4675 ); 4676 SQLITE_API int SQLITE_STDCALL sqlite3_create_collation_v2( 4677 sqlite3*, 4678 const char *zName, 4679 int eTextRep, 4680 void *pArg, 4681 int(*xCompare)(void*,int,const void*,int,const void*), 4682 void(*xDestroy)(void*) 4683 ); 4684 SQLITE_API int SQLITE_STDCALL sqlite3_create_collation16( 4685 sqlite3*, 4686 const void *zName, 4687 int eTextRep, 4688 void *pArg, 4689 int(*xCompare)(void*,int,const void*,int,const void*) 4690 ); 4691 4692 /* 4693 ** CAPI3REF: Collation Needed Callbacks 4694 ** 4695 ** ^To avoid having to register all collation sequences before a database 4696 ** can be used, a single callback function may be registered with the 4697 ** [database connection] to be invoked whenever an undefined collation 4698 ** sequence is required. 4699 ** 4700 ** ^If the function is registered using the sqlite3_collation_needed() API, 4701 ** then it is passed the names of undefined collation sequences as strings 4702 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 4703 ** the names are passed as UTF-16 in machine native byte order. 4704 ** ^A call to either function replaces the existing collation-needed callback. 4705 ** 4706 ** ^(When the callback is invoked, the first argument passed is a copy 4707 ** of the second argument to sqlite3_collation_needed() or 4708 ** sqlite3_collation_needed16(). The second argument is the database 4709 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 4710 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 4711 ** sequence function required. The fourth parameter is the name of the 4712 ** required collation sequence.)^ 4713 ** 4714 ** The callback function should register the desired collation using 4715 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4716 ** [sqlite3_create_collation_v2()]. 4717 */ 4718 SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed( 4719 sqlite3*, 4720 void*, 4721 void(*)(void*,sqlite3*,int eTextRep,const char*) 4722 ); 4723 SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed16( 4724 sqlite3*, 4725 void*, 4726 void(*)(void*,sqlite3*,int eTextRep,const void*) 4727 ); 4728 4729 #ifdef SQLITE_HAS_CODEC 4730 /* 4731 ** Specify the key for an encrypted database. This routine should be 4732 ** called right after sqlite3_open(). 4733 ** 4734 ** The code to implement this API is not available in the public release 4735 ** of SQLite. 4736 */ 4737 SQLITE_API int SQLITE_STDCALL sqlite3_key( 4738 sqlite3 *db, /* Database to be rekeyed */ 4739 const void *pKey, int nKey /* The key */ 4740 ); 4741 SQLITE_API int SQLITE_STDCALL sqlite3_key_v2( 4742 sqlite3 *db, /* Database to be rekeyed */ 4743 const char *zDbName, /* Name of the database */ 4744 const void *pKey, int nKey /* The key */ 4745 ); 4746 4747 /* 4748 ** Change the key on an open database. If the current database is not 4749 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4750 ** database is decrypted. 4751 ** 4752 ** The code to implement this API is not available in the public release 4753 ** of SQLite. 4754 */ 4755 SQLITE_API int SQLITE_STDCALL sqlite3_rekey( 4756 sqlite3 *db, /* Database to be rekeyed */ 4757 const void *pKey, int nKey /* The new key */ 4758 ); 4759 SQLITE_API int SQLITE_STDCALL sqlite3_rekey_v2( 4760 sqlite3 *db, /* Database to be rekeyed */ 4761 const char *zDbName, /* Name of the database */ 4762 const void *pKey, int nKey /* The new key */ 4763 ); 4764 4765 /* 4766 ** Specify the activation key for a SEE database. Unless 4767 ** activated, none of the SEE routines will work. 4768 */ 4769 SQLITE_API void SQLITE_STDCALL sqlite3_activate_see( 4770 const char *zPassPhrase /* Activation phrase */ 4771 ); 4772 #endif 4773 4774 #ifdef SQLITE_ENABLE_CEROD 4775 /* 4776 ** Specify the activation key for a CEROD database. Unless 4777 ** activated, none of the CEROD routines will work. 4778 */ 4779 SQLITE_API void SQLITE_STDCALL sqlite3_activate_cerod( 4780 const char *zPassPhrase /* Activation phrase */ 4781 ); 4782 #endif 4783 4784 /* 4785 ** CAPI3REF: Suspend Execution For A Short Time 4786 ** 4787 ** The sqlite3_sleep() function causes the current thread to suspend execution 4788 ** for at least a number of milliseconds specified in its parameter. 4789 ** 4790 ** If the operating system does not support sleep requests with 4791 ** millisecond time resolution, then the time will be rounded up to 4792 ** the nearest second. The number of milliseconds of sleep actually 4793 ** requested from the operating system is returned. 4794 ** 4795 ** ^SQLite implements this interface by calling the xSleep() 4796 ** method of the default [sqlite3_vfs] object. If the xSleep() method 4797 ** of the default VFS is not implemented correctly, or not implemented at 4798 ** all, then the behavior of sqlite3_sleep() may deviate from the description 4799 ** in the previous paragraphs. 4800 */ 4801 SQLITE_API int SQLITE_STDCALL sqlite3_sleep(int); 4802 4803 /* 4804 ** CAPI3REF: Name Of The Folder Holding Temporary Files 4805 ** 4806 ** ^(If this global variable is made to point to a string which is 4807 ** the name of a folder (a.k.a. directory), then all temporary files 4808 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 4809 ** will be placed in that directory.)^ ^If this variable 4810 ** is a NULL pointer, then SQLite performs a search for an appropriate 4811 ** temporary file directory. 4812 ** 4813 ** Applications are strongly discouraged from using this global variable. 4814 ** It is required to set a temporary folder on Windows Runtime (WinRT). 4815 ** But for all other platforms, it is highly recommended that applications 4816 ** neither read nor write this variable. This global variable is a relic 4817 ** that exists for backwards compatibility of legacy applications and should 4818 ** be avoided in new projects. 4819 ** 4820 ** It is not safe to read or modify this variable in more than one 4821 ** thread at a time. It is not safe to read or modify this variable 4822 ** if a [database connection] is being used at the same time in a separate 4823 ** thread. 4824 ** It is intended that this variable be set once 4825 ** as part of process initialization and before any SQLite interface 4826 ** routines have been called and that this variable remain unchanged 4827 ** thereafter. 4828 ** 4829 ** ^The [temp_store_directory pragma] may modify this variable and cause 4830 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4831 ** the [temp_store_directory pragma] always assumes that any string 4832 ** that this variable points to is held in memory obtained from 4833 ** [sqlite3_malloc] and the pragma may attempt to free that memory 4834 ** using [sqlite3_free]. 4835 ** Hence, if this variable is modified directly, either it should be 4836 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 4837 ** or else the use of the [temp_store_directory pragma] should be avoided. 4838 ** Except when requested by the [temp_store_directory pragma], SQLite 4839 ** does not free the memory that sqlite3_temp_directory points to. If 4840 ** the application wants that memory to be freed, it must do 4841 ** so itself, taking care to only do so after all [database connection] 4842 ** objects have been destroyed. 4843 ** 4844 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 4845 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 4846 ** features that require the use of temporary files may fail. Here is an 4847 ** example of how to do this using C++ with the Windows Runtime: 4848 ** 4849 ** <blockquote><pre> 4850 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 4851 ** TemporaryFolder->Path->Data(); 4852 ** char zPathBuf[MAX_PATH + 1]; 4853 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 4854 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 4855 ** NULL, NULL); 4856 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 4857 ** </pre></blockquote> 4858 */ 4859 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 4860 4861 /* 4862 ** CAPI3REF: Name Of The Folder Holding Database Files 4863 ** 4864 ** ^(If this global variable is made to point to a string which is 4865 ** the name of a folder (a.k.a. directory), then all database files 4866 ** specified with a relative pathname and created or accessed by 4867 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 4868 ** to be relative to that directory.)^ ^If this variable is a NULL 4869 ** pointer, then SQLite assumes that all database files specified 4870 ** with a relative pathname are relative to the current directory 4871 ** for the process. Only the windows VFS makes use of this global 4872 ** variable; it is ignored by the unix VFS. 4873 ** 4874 ** Changing the value of this variable while a database connection is 4875 ** open can result in a corrupt database. 4876 ** 4877 ** It is not safe to read or modify this variable in more than one 4878 ** thread at a time. It is not safe to read or modify this variable 4879 ** if a [database connection] is being used at the same time in a separate 4880 ** thread. 4881 ** It is intended that this variable be set once 4882 ** as part of process initialization and before any SQLite interface 4883 ** routines have been called and that this variable remain unchanged 4884 ** thereafter. 4885 ** 4886 ** ^The [data_store_directory pragma] may modify this variable and cause 4887 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4888 ** the [data_store_directory pragma] always assumes that any string 4889 ** that this variable points to is held in memory obtained from 4890 ** [sqlite3_malloc] and the pragma may attempt to free that memory 4891 ** using [sqlite3_free]. 4892 ** Hence, if this variable is modified directly, either it should be 4893 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 4894 ** or else the use of the [data_store_directory pragma] should be avoided. 4895 */ 4896 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 4897 4898 /* 4899 ** CAPI3REF: Test For Auto-Commit Mode 4900 ** KEYWORDS: {autocommit mode} 4901 ** 4902 ** ^The sqlite3_get_autocommit() interface returns non-zero or 4903 ** zero if the given database connection is or is not in autocommit mode, 4904 ** respectively. ^Autocommit mode is on by default. 4905 ** ^Autocommit mode is disabled by a [BEGIN] statement. 4906 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 4907 ** 4908 ** If certain kinds of errors occur on a statement within a multi-statement 4909 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 4910 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 4911 ** transaction might be rolled back automatically. The only way to 4912 ** find out whether SQLite automatically rolled back the transaction after 4913 ** an error is to use this function. 4914 ** 4915 ** If another thread changes the autocommit status of the database 4916 ** connection while this routine is running, then the return value 4917 ** is undefined. 4918 */ 4919 SQLITE_API int SQLITE_STDCALL sqlite3_get_autocommit(sqlite3*); 4920 4921 /* 4922 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 4923 ** 4924 ** ^The sqlite3_db_handle interface returns the [database connection] handle 4925 ** to which a [prepared statement] belongs. ^The [database connection] 4926 ** returned by sqlite3_db_handle is the same [database connection] 4927 ** that was the first argument 4928 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 4929 ** create the statement in the first place. 4930 */ 4931 SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_db_handle(sqlite3_stmt*); 4932 4933 /* 4934 ** CAPI3REF: Return The Filename For A Database Connection 4935 ** 4936 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 4937 ** associated with database N of connection D. ^The main database file 4938 ** has the name "main". If there is no attached database N on the database 4939 ** connection D, or if database N is a temporary or in-memory database, then 4940 ** a NULL pointer is returned. 4941 ** 4942 ** ^The filename returned by this function is the output of the 4943 ** xFullPathname method of the [VFS]. ^In other words, the filename 4944 ** will be an absolute pathname, even if the filename used 4945 ** to open the database originally was a URI or relative pathname. 4946 */ 4947 SQLITE_API const char *SQLITE_STDCALL sqlite3_db_filename(sqlite3 *db, const char *zDbName); 4948 4949 /* 4950 ** CAPI3REF: Determine if a database is read-only 4951 ** 4952 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 4953 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 4954 ** the name of a database on connection D. 4955 */ 4956 SQLITE_API int SQLITE_STDCALL sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 4957 4958 /* 4959 ** CAPI3REF: Find the next prepared statement 4960 ** 4961 ** ^This interface returns a pointer to the next [prepared statement] after 4962 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 4963 ** then this interface returns a pointer to the first prepared statement 4964 ** associated with the database connection pDb. ^If no prepared statement 4965 ** satisfies the conditions of this routine, it returns NULL. 4966 ** 4967 ** The [database connection] pointer D in a call to 4968 ** [sqlite3_next_stmt(D,S)] must refer to an open database 4969 ** connection and in particular must not be a NULL pointer. 4970 */ 4971 SQLITE_API sqlite3_stmt *SQLITE_STDCALL sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 4972 4973 /* 4974 ** CAPI3REF: Commit And Rollback Notification Callbacks 4975 ** 4976 ** ^The sqlite3_commit_hook() interface registers a callback 4977 ** function to be invoked whenever a transaction is [COMMIT | committed]. 4978 ** ^Any callback set by a previous call to sqlite3_commit_hook() 4979 ** for the same database connection is overridden. 4980 ** ^The sqlite3_rollback_hook() interface registers a callback 4981 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 4982 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 4983 ** for the same database connection is overridden. 4984 ** ^The pArg argument is passed through to the callback. 4985 ** ^If the callback on a commit hook function returns non-zero, 4986 ** then the commit is converted into a rollback. 4987 ** 4988 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 4989 ** return the P argument from the previous call of the same function 4990 ** on the same [database connection] D, or NULL for 4991 ** the first call for each function on D. 4992 ** 4993 ** The commit and rollback hook callbacks are not reentrant. 4994 ** The callback implementation must not do anything that will modify 4995 ** the database connection that invoked the callback. Any actions 4996 ** to modify the database connection must be deferred until after the 4997 ** completion of the [sqlite3_step()] call that triggered the commit 4998 ** or rollback hook in the first place. 4999 ** Note that running any other SQL statements, including SELECT statements, 5000 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5001 ** the database connections for the meaning of "modify" in this paragraph. 5002 ** 5003 ** ^Registering a NULL function disables the callback. 5004 ** 5005 ** ^When the commit hook callback routine returns zero, the [COMMIT] 5006 ** operation is allowed to continue normally. ^If the commit hook 5007 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5008 ** ^The rollback hook is invoked on a rollback that results from a commit 5009 ** hook returning non-zero, just as it would be with any other rollback. 5010 ** 5011 ** ^For the purposes of this API, a transaction is said to have been 5012 ** rolled back if an explicit "ROLLBACK" statement is executed, or 5013 ** an error or constraint causes an implicit rollback to occur. 5014 ** ^The rollback callback is not invoked if a transaction is 5015 ** automatically rolled back because the database connection is closed. 5016 ** 5017 ** See also the [sqlite3_update_hook()] interface. 5018 */ 5019 SQLITE_API void *SQLITE_STDCALL sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5020 SQLITE_API void *SQLITE_STDCALL sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5021 5022 /* 5023 ** CAPI3REF: Data Change Notification Callbacks 5024 ** 5025 ** ^The sqlite3_update_hook() interface registers a callback function 5026 ** with the [database connection] identified by the first argument 5027 ** to be invoked whenever a row is updated, inserted or deleted in 5028 ** a rowid table. 5029 ** ^Any callback set by a previous call to this function 5030 ** for the same database connection is overridden. 5031 ** 5032 ** ^The second argument is a pointer to the function to invoke when a 5033 ** row is updated, inserted or deleted in a rowid table. 5034 ** ^The first argument to the callback is a copy of the third argument 5035 ** to sqlite3_update_hook(). 5036 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5037 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 5038 ** to be invoked. 5039 ** ^The third and fourth arguments to the callback contain pointers to the 5040 ** database and table name containing the affected row. 5041 ** ^The final callback parameter is the [rowid] of the row. 5042 ** ^In the case of an update, this is the [rowid] after the update takes place. 5043 ** 5044 ** ^(The update hook is not invoked when internal system tables are 5045 ** modified (i.e. sqlite_master and sqlite_sequence).)^ 5046 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5047 ** 5048 ** ^In the current implementation, the update hook 5049 ** is not invoked when duplication rows are deleted because of an 5050 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5051 ** invoked when rows are deleted using the [truncate optimization]. 5052 ** The exceptions defined in this paragraph might change in a future 5053 ** release of SQLite. 5054 ** 5055 ** The update hook implementation must not do anything that will modify 5056 ** the database connection that invoked the update hook. Any actions 5057 ** to modify the database connection must be deferred until after the 5058 ** completion of the [sqlite3_step()] call that triggered the update hook. 5059 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5060 ** database connections for the meaning of "modify" in this paragraph. 5061 ** 5062 ** ^The sqlite3_update_hook(D,C,P) function 5063 ** returns the P argument from the previous call 5064 ** on the same [database connection] D, or NULL for 5065 ** the first call on D. 5066 ** 5067 ** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] 5068 ** interfaces. 5069 */ 5070 SQLITE_API void *SQLITE_STDCALL sqlite3_update_hook( 5071 sqlite3*, 5072 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5073 void* 5074 ); 5075 5076 /* 5077 ** CAPI3REF: Enable Or Disable Shared Pager Cache 5078 ** 5079 ** ^(This routine enables or disables the sharing of the database cache 5080 ** and schema data structures between [database connection | connections] 5081 ** to the same database. Sharing is enabled if the argument is true 5082 ** and disabled if the argument is false.)^ 5083 ** 5084 ** ^Cache sharing is enabled and disabled for an entire process. 5085 ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 5086 ** sharing was enabled or disabled for each thread separately. 5087 ** 5088 ** ^(The cache sharing mode set by this interface effects all subsequent 5089 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5090 ** Existing database connections continue use the sharing mode 5091 ** that was in effect at the time they were opened.)^ 5092 ** 5093 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5094 ** successfully. An [error code] is returned otherwise.)^ 5095 ** 5096 ** ^Shared cache is disabled by default. But this might change in 5097 ** future releases of SQLite. Applications that care about shared 5098 ** cache setting should set it explicitly. 5099 ** 5100 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5101 ** and will always return SQLITE_MISUSE. On those systems, 5102 ** shared cache mode should be enabled per-database connection via 5103 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5104 ** 5105 ** This interface is threadsafe on processors where writing a 5106 ** 32-bit integer is atomic. 5107 ** 5108 ** See Also: [SQLite Shared-Cache Mode] 5109 */ 5110 SQLITE_API int SQLITE_STDCALL sqlite3_enable_shared_cache(int); 5111 5112 /* 5113 ** CAPI3REF: Attempt To Free Heap Memory 5114 ** 5115 ** ^The sqlite3_release_memory() interface attempts to free N bytes 5116 ** of heap memory by deallocating non-essential memory allocations 5117 ** held by the database library. Memory used to cache database 5118 ** pages to improve performance is an example of non-essential memory. 5119 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 5120 ** which might be more or less than the amount requested. 5121 ** ^The sqlite3_release_memory() routine is a no-op returning zero 5122 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5123 ** 5124 ** See also: [sqlite3_db_release_memory()] 5125 */ 5126 SQLITE_API int SQLITE_STDCALL sqlite3_release_memory(int); 5127 5128 /* 5129 ** CAPI3REF: Free Memory Used By A Database Connection 5130 ** 5131 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5132 ** memory as possible from database connection D. Unlike the 5133 ** [sqlite3_release_memory()] interface, this interface is in effect even 5134 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5135 ** omitted. 5136 ** 5137 ** See also: [sqlite3_release_memory()] 5138 */ 5139 SQLITE_API int SQLITE_STDCALL sqlite3_db_release_memory(sqlite3*); 5140 5141 /* 5142 ** CAPI3REF: Impose A Limit On Heap Size 5143 ** 5144 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5145 ** soft limit on the amount of heap memory that may be allocated by SQLite. 5146 ** ^SQLite strives to keep heap memory utilization below the soft heap 5147 ** limit by reducing the number of pages held in the page cache 5148 ** as heap memory usages approaches the limit. 5149 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 5150 ** below the limit, it will exceed the limit rather than generate 5151 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5152 ** is advisory only. 5153 ** 5154 ** ^The return value from sqlite3_soft_heap_limit64() is the size of 5155 ** the soft heap limit prior to the call, or negative in the case of an 5156 ** error. ^If the argument N is negative 5157 ** then no change is made to the soft heap limit. Hence, the current 5158 ** size of the soft heap limit can be determined by invoking 5159 ** sqlite3_soft_heap_limit64() with a negative argument. 5160 ** 5161 ** ^If the argument N is zero then the soft heap limit is disabled. 5162 ** 5163 ** ^(The soft heap limit is not enforced in the current implementation 5164 ** if one or more of following conditions are true: 5165 ** 5166 ** <ul> 5167 ** <li> The soft heap limit is set to zero. 5168 ** <li> Memory accounting is disabled using a combination of the 5169 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5170 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5171 ** <li> An alternative page cache implementation is specified using 5172 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5173 ** <li> The page cache allocates from its own memory pool supplied 5174 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5175 ** from the heap. 5176 ** </ul>)^ 5177 ** 5178 ** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 5179 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5180 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5181 ** the soft heap limit is enforced on every memory allocation. Without 5182 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5183 ** when memory is allocated by the page cache. Testing suggests that because 5184 ** the page cache is the predominate memory user in SQLite, most 5185 ** applications will achieve adequate soft heap limit enforcement without 5186 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5187 ** 5188 ** The circumstances under which SQLite will enforce the soft heap limit may 5189 ** changes in future releases of SQLite. 5190 */ 5191 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_soft_heap_limit64(sqlite3_int64 N); 5192 5193 /* 5194 ** CAPI3REF: Deprecated Soft Heap Limit Interface 5195 ** DEPRECATED 5196 ** 5197 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5198 ** interface. This routine is provided for historical compatibility 5199 ** only. All new applications should use the 5200 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 5201 */ 5202 SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_soft_heap_limit(int N); 5203 5204 5205 /* 5206 ** CAPI3REF: Extract Metadata About A Column Of A Table 5207 ** 5208 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 5209 ** information about column C of table T in database D 5210 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 5211 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 5212 ** the final five arguments with appropriate values if the specified 5213 ** column exists. ^The sqlite3_table_column_metadata() interface returns 5214 ** SQLITE_ERROR and if the specified column does not exist. 5215 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 5216 ** NULL pointer, then this routine simply checks for the existance of the 5217 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 5218 ** does not. 5219 ** 5220 ** ^The column is identified by the second, third and fourth parameters to 5221 ** this function. ^(The second parameter is either the name of the database 5222 ** (i.e. "main", "temp", or an attached database) containing the specified 5223 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 5224 ** for the table using the same algorithm used by the database engine to 5225 ** resolve unqualified table references. 5226 ** 5227 ** ^The third and fourth parameters to this function are the table and column 5228 ** name of the desired column, respectively. 5229 ** 5230 ** ^Metadata is returned by writing to the memory locations passed as the 5th 5231 ** and subsequent parameters to this function. ^Any of these arguments may be 5232 ** NULL, in which case the corresponding element of metadata is omitted. 5233 ** 5234 ** ^(<blockquote> 5235 ** <table border="1"> 5236 ** <tr><th> Parameter <th> Output<br>Type <th> Description 5237 ** 5238 ** <tr><td> 5th <td> const char* <td> Data type 5239 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5240 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5241 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5242 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5243 ** </table> 5244 ** </blockquote>)^ 5245 ** 5246 ** ^The memory pointed to by the character pointers returned for the 5247 ** declaration type and collation sequence is valid until the next 5248 ** call to any SQLite API function. 5249 ** 5250 ** ^If the specified table is actually a view, an [error code] is returned. 5251 ** 5252 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 5253 ** is not a [WITHOUT ROWID] table and an 5254 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5255 ** parameters are set for the explicitly declared column. ^(If there is no 5256 ** [INTEGER PRIMARY KEY] column, then the outputs 5257 ** for the [rowid] are set as follows: 5258 ** 5259 ** <pre> 5260 ** data type: "INTEGER" 5261 ** collation sequence: "BINARY" 5262 ** not null: 0 5263 ** primary key: 1 5264 ** auto increment: 0 5265 ** </pre>)^ 5266 ** 5267 ** ^This function causes all database schemas to be read from disk and 5268 ** parsed, if that has not already been done, and returns an error if 5269 ** any errors are encountered while loading the schema. 5270 */ 5271 SQLITE_API int SQLITE_STDCALL sqlite3_table_column_metadata( 5272 sqlite3 *db, /* Connection handle */ 5273 const char *zDbName, /* Database name or NULL */ 5274 const char *zTableName, /* Table name */ 5275 const char *zColumnName, /* Column name */ 5276 char const **pzDataType, /* OUTPUT: Declared data type */ 5277 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5278 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5279 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5280 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5281 ); 5282 5283 /* 5284 ** CAPI3REF: Load An Extension 5285 ** 5286 ** ^This interface loads an SQLite extension library from the named file. 5287 ** 5288 ** ^The sqlite3_load_extension() interface attempts to load an 5289 ** [SQLite extension] library contained in the file zFile. If 5290 ** the file cannot be loaded directly, attempts are made to load 5291 ** with various operating-system specific extensions added. 5292 ** So for example, if "samplelib" cannot be loaded, then names like 5293 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5294 ** be tried also. 5295 ** 5296 ** ^The entry point is zProc. 5297 ** ^(zProc may be 0, in which case SQLite will try to come up with an 5298 ** entry point name on its own. It first tries "sqlite3_extension_init". 5299 ** If that does not work, it constructs a name "sqlite3_X_init" where the 5300 ** X is consists of the lower-case equivalent of all ASCII alphabetic 5301 ** characters in the filename from the last "/" to the first following 5302 ** "." and omitting any initial "lib".)^ 5303 ** ^The sqlite3_load_extension() interface returns 5304 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5305 ** ^If an error occurs and pzErrMsg is not 0, then the 5306 ** [sqlite3_load_extension()] interface shall attempt to 5307 ** fill *pzErrMsg with error message text stored in memory 5308 ** obtained from [sqlite3_malloc()]. The calling function 5309 ** should free this memory by calling [sqlite3_free()]. 5310 ** 5311 ** ^Extension loading must be enabled using 5312 ** [sqlite3_enable_load_extension()] prior to calling this API, 5313 ** otherwise an error will be returned. 5314 ** 5315 ** See also the [load_extension() SQL function]. 5316 */ 5317 SQLITE_API int SQLITE_STDCALL sqlite3_load_extension( 5318 sqlite3 *db, /* Load the extension into this database connection */ 5319 const char *zFile, /* Name of the shared library containing extension */ 5320 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5321 char **pzErrMsg /* Put error message here if not 0 */ 5322 ); 5323 5324 /* 5325 ** CAPI3REF: Enable Or Disable Extension Loading 5326 ** 5327 ** ^So as not to open security holes in older applications that are 5328 ** unprepared to deal with [extension loading], and as a means of disabling 5329 ** [extension loading] while evaluating user-entered SQL, the following API 5330 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5331 ** 5332 ** ^Extension loading is off by default. 5333 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5334 ** to turn extension loading on and call it with onoff==0 to turn 5335 ** it back off again. 5336 */ 5337 SQLITE_API int SQLITE_STDCALL sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5338 5339 /* 5340 ** CAPI3REF: Automatically Load Statically Linked Extensions 5341 ** 5342 ** ^This interface causes the xEntryPoint() function to be invoked for 5343 ** each new [database connection] that is created. The idea here is that 5344 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5345 ** that is to be automatically loaded into all new database connections. 5346 ** 5347 ** ^(Even though the function prototype shows that xEntryPoint() takes 5348 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 5349 ** arguments and expects and integer result as if the signature of the 5350 ** entry point where as follows: 5351 ** 5352 ** <blockquote><pre> 5353 ** int xEntryPoint( 5354 ** sqlite3 *db, 5355 ** const char **pzErrMsg, 5356 ** const struct sqlite3_api_routines *pThunk 5357 ** ); 5358 ** </pre></blockquote>)^ 5359 ** 5360 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5361 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5362 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5363 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5364 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5365 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5366 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5367 ** 5368 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5369 ** on the list of automatic extensions is a harmless no-op. ^No entry point 5370 ** will be called more than once for each database connection that is opened. 5371 ** 5372 ** See also: [sqlite3_reset_auto_extension()] 5373 ** and [sqlite3_cancel_auto_extension()] 5374 */ 5375 SQLITE_API int SQLITE_STDCALL sqlite3_auto_extension(void (*xEntryPoint)(void)); 5376 5377 /* 5378 ** CAPI3REF: Cancel Automatic Extension Loading 5379 ** 5380 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 5381 ** initialization routine X that was registered using a prior call to 5382 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 5383 ** routine returns 1 if initialization routine X was successfully 5384 ** unregistered and it returns 0 if X was not on the list of initialization 5385 ** routines. 5386 */ 5387 SQLITE_API int SQLITE_STDCALL sqlite3_cancel_auto_extension(void (*xEntryPoint)(void)); 5388 5389 /* 5390 ** CAPI3REF: Reset Automatic Extension Loading 5391 ** 5392 ** ^This interface disables all automatic extensions previously 5393 ** registered using [sqlite3_auto_extension()]. 5394 */ 5395 SQLITE_API void SQLITE_STDCALL sqlite3_reset_auto_extension(void); 5396 5397 /* 5398 ** The interface to the virtual-table mechanism is currently considered 5399 ** to be experimental. The interface might change in incompatible ways. 5400 ** If this is a problem for you, do not use the interface at this time. 5401 ** 5402 ** When the virtual-table mechanism stabilizes, we will declare the 5403 ** interface fixed, support it indefinitely, and remove this comment. 5404 */ 5405 5406 /* 5407 ** Structures used by the virtual table interface 5408 */ 5409 typedef struct sqlite3_vtab sqlite3_vtab; 5410 typedef struct sqlite3_index_info sqlite3_index_info; 5411 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5412 typedef struct sqlite3_module sqlite3_module; 5413 5414 /* 5415 ** CAPI3REF: Virtual Table Object 5416 ** KEYWORDS: sqlite3_module {virtual table module} 5417 ** 5418 ** This structure, sometimes called a "virtual table module", 5419 ** defines the implementation of a [virtual tables]. 5420 ** This structure consists mostly of methods for the module. 5421 ** 5422 ** ^A virtual table module is created by filling in a persistent 5423 ** instance of this structure and passing a pointer to that instance 5424 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5425 ** ^The registration remains valid until it is replaced by a different 5426 ** module or until the [database connection] closes. The content 5427 ** of this structure must not change while it is registered with 5428 ** any database connection. 5429 */ 5430 struct sqlite3_module { 5431 int iVersion; 5432 int (*xCreate)(sqlite3*, void *pAux, 5433 int argc, const char *const*argv, 5434 sqlite3_vtab **ppVTab, char**); 5435 int (*xConnect)(sqlite3*, void *pAux, 5436 int argc, const char *const*argv, 5437 sqlite3_vtab **ppVTab, char**); 5438 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5439 int (*xDisconnect)(sqlite3_vtab *pVTab); 5440 int (*xDestroy)(sqlite3_vtab *pVTab); 5441 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5442 int (*xClose)(sqlite3_vtab_cursor*); 5443 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5444 int argc, sqlite3_value **argv); 5445 int (*xNext)(sqlite3_vtab_cursor*); 5446 int (*xEof)(sqlite3_vtab_cursor*); 5447 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5448 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5449 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5450 int (*xBegin)(sqlite3_vtab *pVTab); 5451 int (*xSync)(sqlite3_vtab *pVTab); 5452 int (*xCommit)(sqlite3_vtab *pVTab); 5453 int (*xRollback)(sqlite3_vtab *pVTab); 5454 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5455 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5456 void **ppArg); 5457 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5458 /* The methods above are in version 1 of the sqlite_module object. Those 5459 ** below are for version 2 and greater. */ 5460 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5461 int (*xRelease)(sqlite3_vtab *pVTab, int); 5462 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5463 }; 5464 5465 /* 5466 ** CAPI3REF: Virtual Table Indexing Information 5467 ** KEYWORDS: sqlite3_index_info 5468 ** 5469 ** The sqlite3_index_info structure and its substructures is used as part 5470 ** of the [virtual table] interface to 5471 ** pass information into and receive the reply from the [xBestIndex] 5472 ** method of a [virtual table module]. The fields under **Inputs** are the 5473 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 5474 ** results into the **Outputs** fields. 5475 ** 5476 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 5477 ** 5478 ** <blockquote>column OP expr</blockquote> 5479 ** 5480 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5481 ** stored in aConstraint[].op using one of the 5482 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5483 ** ^(The index of the column is stored in 5484 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5485 ** expr on the right-hand side can be evaluated (and thus the constraint 5486 ** is usable) and false if it cannot.)^ 5487 ** 5488 ** ^The optimizer automatically inverts terms of the form "expr OP column" 5489 ** and makes other simplifications to the WHERE clause in an attempt to 5490 ** get as many WHERE clause terms into the form shown above as possible. 5491 ** ^The aConstraint[] array only reports WHERE clause terms that are 5492 ** relevant to the particular virtual table being queried. 5493 ** 5494 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5495 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 5496 ** 5497 ** The [xBestIndex] method must fill aConstraintUsage[] with information 5498 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 5499 ** the right-hand side of the corresponding aConstraint[] is evaluated 5500 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5501 ** is true, then the constraint is assumed to be fully handled by the 5502 ** virtual table and is not checked again by SQLite.)^ 5503 ** 5504 ** ^The idxNum and idxPtr values are recorded and passed into the 5505 ** [xFilter] method. 5506 ** ^[sqlite3_free()] is used to free idxPtr if and only if 5507 ** needToFreeIdxPtr is true. 5508 ** 5509 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5510 ** the correct order to satisfy the ORDER BY clause so that no separate 5511 ** sorting step is required. 5512 ** 5513 ** ^The estimatedCost value is an estimate of the cost of a particular 5514 ** strategy. A cost of N indicates that the cost of the strategy is similar 5515 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 5516 ** indicates that the expense of the operation is similar to that of a 5517 ** binary search on a unique indexed field of an SQLite table with N rows. 5518 ** 5519 ** ^The estimatedRows value is an estimate of the number of rows that 5520 ** will be returned by the strategy. 5521 ** 5522 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 5523 ** structure for SQLite version 3.8.2. If a virtual table extension is 5524 ** used with an SQLite version earlier than 3.8.2, the results of attempting 5525 ** to read or write the estimatedRows field are undefined (but are likely 5526 ** to included crashing the application). The estimatedRows field should 5527 ** therefore only be used if [sqlite3_libversion_number()] returns a 5528 ** value greater than or equal to 3008002. 5529 */ 5530 struct sqlite3_index_info { 5531 /* Inputs */ 5532 int nConstraint; /* Number of entries in aConstraint */ 5533 struct sqlite3_index_constraint { 5534 int iColumn; /* Column on left-hand side of constraint */ 5535 unsigned char op; /* Constraint operator */ 5536 unsigned char usable; /* True if this constraint is usable */ 5537 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5538 } *aConstraint; /* Table of WHERE clause constraints */ 5539 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5540 struct sqlite3_index_orderby { 5541 int iColumn; /* Column number */ 5542 unsigned char desc; /* True for DESC. False for ASC. */ 5543 } *aOrderBy; /* The ORDER BY clause */ 5544 /* Outputs */ 5545 struct sqlite3_index_constraint_usage { 5546 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5547 unsigned char omit; /* Do not code a test for this constraint */ 5548 } *aConstraintUsage; 5549 int idxNum; /* Number used to identify the index */ 5550 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5551 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5552 int orderByConsumed; /* True if output is already ordered */ 5553 double estimatedCost; /* Estimated cost of using this index */ 5554 /* Fields below are only available in SQLite 3.8.2 and later */ 5555 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 5556 }; 5557 5558 /* 5559 ** CAPI3REF: Virtual Table Constraint Operator Codes 5560 ** 5561 ** These macros defined the allowed values for the 5562 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 5563 ** an operator that is part of a constraint term in the wHERE clause of 5564 ** a query that uses a [virtual table]. 5565 */ 5566 #define SQLITE_INDEX_CONSTRAINT_EQ 2 5567 #define SQLITE_INDEX_CONSTRAINT_GT 4 5568 #define SQLITE_INDEX_CONSTRAINT_LE 8 5569 #define SQLITE_INDEX_CONSTRAINT_LT 16 5570 #define SQLITE_INDEX_CONSTRAINT_GE 32 5571 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 5572 5573 /* 5574 ** CAPI3REF: Register A Virtual Table Implementation 5575 ** 5576 ** ^These routines are used to register a new [virtual table module] name. 5577 ** ^Module names must be registered before 5578 ** creating a new [virtual table] using the module and before using a 5579 ** preexisting [virtual table] for the module. 5580 ** 5581 ** ^The module name is registered on the [database connection] specified 5582 ** by the first parameter. ^The name of the module is given by the 5583 ** second parameter. ^The third parameter is a pointer to 5584 ** the implementation of the [virtual table module]. ^The fourth 5585 ** parameter is an arbitrary client data pointer that is passed through 5586 ** into the [xCreate] and [xConnect] methods of the virtual table module 5587 ** when a new virtual table is be being created or reinitialized. 5588 ** 5589 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 5590 ** is a pointer to a destructor for the pClientData. ^SQLite will 5591 ** invoke the destructor function (if it is not NULL) when SQLite 5592 ** no longer needs the pClientData pointer. ^The destructor will also 5593 ** be invoked if the call to sqlite3_create_module_v2() fails. 5594 ** ^The sqlite3_create_module() 5595 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 5596 ** destructor. 5597 */ 5598 SQLITE_API int SQLITE_STDCALL sqlite3_create_module( 5599 sqlite3 *db, /* SQLite connection to register module with */ 5600 const char *zName, /* Name of the module */ 5601 const sqlite3_module *p, /* Methods for the module */ 5602 void *pClientData /* Client data for xCreate/xConnect */ 5603 ); 5604 SQLITE_API int SQLITE_STDCALL sqlite3_create_module_v2( 5605 sqlite3 *db, /* SQLite connection to register module with */ 5606 const char *zName, /* Name of the module */ 5607 const sqlite3_module *p, /* Methods for the module */ 5608 void *pClientData, /* Client data for xCreate/xConnect */ 5609 void(*xDestroy)(void*) /* Module destructor function */ 5610 ); 5611 5612 /* 5613 ** CAPI3REF: Virtual Table Instance Object 5614 ** KEYWORDS: sqlite3_vtab 5615 ** 5616 ** Every [virtual table module] implementation uses a subclass 5617 ** of this object to describe a particular instance 5618 ** of the [virtual table]. Each subclass will 5619 ** be tailored to the specific needs of the module implementation. 5620 ** The purpose of this superclass is to define certain fields that are 5621 ** common to all module implementations. 5622 ** 5623 ** ^Virtual tables methods can set an error message by assigning a 5624 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 5625 ** take care that any prior string is freed by a call to [sqlite3_free()] 5626 ** prior to assigning a new string to zErrMsg. ^After the error message 5627 ** is delivered up to the client application, the string will be automatically 5628 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 5629 */ 5630 struct sqlite3_vtab { 5631 const sqlite3_module *pModule; /* The module for this virtual table */ 5632 int nRef; /* Number of open cursors */ 5633 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 5634 /* Virtual table implementations will typically add additional fields */ 5635 }; 5636 5637 /* 5638 ** CAPI3REF: Virtual Table Cursor Object 5639 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 5640 ** 5641 ** Every [virtual table module] implementation uses a subclass of the 5642 ** following structure to describe cursors that point into the 5643 ** [virtual table] and are used 5644 ** to loop through the virtual table. Cursors are created using the 5645 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 5646 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 5647 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 5648 ** of the module. Each module implementation will define 5649 ** the content of a cursor structure to suit its own needs. 5650 ** 5651 ** This superclass exists in order to define fields of the cursor that 5652 ** are common to all implementations. 5653 */ 5654 struct sqlite3_vtab_cursor { 5655 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 5656 /* Virtual table implementations will typically add additional fields */ 5657 }; 5658 5659 /* 5660 ** CAPI3REF: Declare The Schema Of A Virtual Table 5661 ** 5662 ** ^The [xCreate] and [xConnect] methods of a 5663 ** [virtual table module] call this interface 5664 ** to declare the format (the names and datatypes of the columns) of 5665 ** the virtual tables they implement. 5666 */ 5667 SQLITE_API int SQLITE_STDCALL sqlite3_declare_vtab(sqlite3*, const char *zSQL); 5668 5669 /* 5670 ** CAPI3REF: Overload A Function For A Virtual Table 5671 ** 5672 ** ^(Virtual tables can provide alternative implementations of functions 5673 ** using the [xFindFunction] method of the [virtual table module]. 5674 ** But global versions of those functions 5675 ** must exist in order to be overloaded.)^ 5676 ** 5677 ** ^(This API makes sure a global version of a function with a particular 5678 ** name and number of parameters exists. If no such function exists 5679 ** before this API is called, a new function is created.)^ ^The implementation 5680 ** of the new function always causes an exception to be thrown. So 5681 ** the new function is not good for anything by itself. Its only 5682 ** purpose is to be a placeholder function that can be overloaded 5683 ** by a [virtual table]. 5684 */ 5685 SQLITE_API int SQLITE_STDCALL sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 5686 5687 /* 5688 ** The interface to the virtual-table mechanism defined above (back up 5689 ** to a comment remarkably similar to this one) is currently considered 5690 ** to be experimental. The interface might change in incompatible ways. 5691 ** If this is a problem for you, do not use the interface at this time. 5692 ** 5693 ** When the virtual-table mechanism stabilizes, we will declare the 5694 ** interface fixed, support it indefinitely, and remove this comment. 5695 */ 5696 5697 /* 5698 ** CAPI3REF: A Handle To An Open BLOB 5699 ** KEYWORDS: {BLOB handle} {BLOB handles} 5700 ** 5701 ** An instance of this object represents an open BLOB on which 5702 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 5703 ** ^Objects of this type are created by [sqlite3_blob_open()] 5704 ** and destroyed by [sqlite3_blob_close()]. 5705 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 5706 ** can be used to read or write small subsections of the BLOB. 5707 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 5708 */ 5709 typedef struct sqlite3_blob sqlite3_blob; 5710 5711 /* 5712 ** CAPI3REF: Open A BLOB For Incremental I/O 5713 ** 5714 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 5715 ** in row iRow, column zColumn, table zTable in database zDb; 5716 ** in other words, the same BLOB that would be selected by: 5717 ** 5718 ** <pre> 5719 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 5720 ** </pre>)^ 5721 ** 5722 ** ^(Parameter zDb is not the filename that contains the database, but 5723 ** rather the symbolic name of the database. For attached databases, this is 5724 ** the name that appears after the AS keyword in the [ATTACH] statement. 5725 ** For the main database file, the database name is "main". For TEMP 5726 ** tables, the database name is "temp".)^ 5727 ** 5728 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 5729 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 5730 ** read-only access. 5731 ** 5732 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 5733 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 5734 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 5735 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 5736 ** on *ppBlob after this function it returns. 5737 ** 5738 ** This function fails with SQLITE_ERROR if any of the following are true: 5739 ** <ul> 5740 ** <li> ^(Database zDb does not exist)^, 5741 ** <li> ^(Table zTable does not exist within database zDb)^, 5742 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 5743 ** <li> ^(Column zColumn does not exist)^, 5744 ** <li> ^(Row iRow is not present in the table)^, 5745 ** <li> ^(The specified column of row iRow contains a value that is not 5746 ** a TEXT or BLOB value)^, 5747 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 5748 ** constraint and the blob is being opened for read/write access)^, 5749 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 5750 ** column zColumn is part of a [child key] definition and the blob is 5751 ** being opened for read/write access)^. 5752 ** </ul> 5753 ** 5754 ** ^Unless it returns SQLITE_MISUSE, this function sets the 5755 ** [database connection] error code and message accessible via 5756 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 5757 ** 5758 ** 5759 ** ^(If the row that a BLOB handle points to is modified by an 5760 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 5761 ** then the BLOB handle is marked as "expired". 5762 ** This is true if any column of the row is changed, even a column 5763 ** other than the one the BLOB handle is open on.)^ 5764 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 5765 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 5766 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 5767 ** rolled back by the expiration of the BLOB. Such changes will eventually 5768 ** commit if the transaction continues to completion.)^ 5769 ** 5770 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 5771 ** the opened blob. ^The size of a blob may not be changed by this 5772 ** interface. Use the [UPDATE] SQL command to change the size of a 5773 ** blob. 5774 ** 5775 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 5776 ** and the built-in [zeroblob] SQL function may be used to create a 5777 ** zero-filled blob to read or write using the incremental-blob interface. 5778 ** 5779 ** To avoid a resource leak, every open [BLOB handle] should eventually 5780 ** be released by a call to [sqlite3_blob_close()]. 5781 */ 5782 SQLITE_API int SQLITE_STDCALL sqlite3_blob_open( 5783 sqlite3*, 5784 const char *zDb, 5785 const char *zTable, 5786 const char *zColumn, 5787 sqlite3_int64 iRow, 5788 int flags, 5789 sqlite3_blob **ppBlob 5790 ); 5791 5792 /* 5793 ** CAPI3REF: Move a BLOB Handle to a New Row 5794 ** 5795 ** ^This function is used to move an existing blob handle so that it points 5796 ** to a different row of the same database table. ^The new row is identified 5797 ** by the rowid value passed as the second argument. Only the row can be 5798 ** changed. ^The database, table and column on which the blob handle is open 5799 ** remain the same. Moving an existing blob handle to a new row can be 5800 ** faster than closing the existing handle and opening a new one. 5801 ** 5802 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 5803 ** it must exist and there must be either a blob or text value stored in 5804 ** the nominated column.)^ ^If the new row is not present in the table, or if 5805 ** it does not contain a blob or text value, or if another error occurs, an 5806 ** SQLite error code is returned and the blob handle is considered aborted. 5807 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 5808 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 5809 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 5810 ** always returns zero. 5811 ** 5812 ** ^This function sets the database handle error code and message. 5813 */ 5814 SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 5815 5816 /* 5817 ** CAPI3REF: Close A BLOB Handle 5818 ** 5819 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 5820 ** unconditionally. Even if this routine returns an error code, the 5821 ** handle is still closed.)^ 5822 ** 5823 ** ^If the blob handle being closed was opened for read-write access, and if 5824 ** the database is in auto-commit mode and there are no other open read-write 5825 ** blob handles or active write statements, the current transaction is 5826 ** committed. ^If an error occurs while committing the transaction, an error 5827 ** code is returned and the transaction rolled back. 5828 ** 5829 ** Calling this function with an argument that is not a NULL pointer or an 5830 ** open blob handle results in undefined behaviour. ^Calling this routine 5831 ** with a null pointer (such as would be returned by a failed call to 5832 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 5833 ** is passed a valid open blob handle, the values returned by the 5834 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 5835 */ 5836 SQLITE_API int SQLITE_STDCALL sqlite3_blob_close(sqlite3_blob *); 5837 5838 /* 5839 ** CAPI3REF: Return The Size Of An Open BLOB 5840 ** 5841 ** ^Returns the size in bytes of the BLOB accessible via the 5842 ** successfully opened [BLOB handle] in its only argument. ^The 5843 ** incremental blob I/O routines can only read or overwriting existing 5844 ** blob content; they cannot change the size of a blob. 5845 ** 5846 ** This routine only works on a [BLOB handle] which has been created 5847 ** by a prior successful call to [sqlite3_blob_open()] and which has not 5848 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5849 ** to this routine results in undefined and probably undesirable behavior. 5850 */ 5851 SQLITE_API int SQLITE_STDCALL sqlite3_blob_bytes(sqlite3_blob *); 5852 5853 /* 5854 ** CAPI3REF: Read Data From A BLOB Incrementally 5855 ** 5856 ** ^(This function is used to read data from an open [BLOB handle] into a 5857 ** caller-supplied buffer. N bytes of data are copied into buffer Z 5858 ** from the open BLOB, starting at offset iOffset.)^ 5859 ** 5860 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 5861 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 5862 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 5863 ** ^The size of the blob (and hence the maximum value of N+iOffset) 5864 ** can be determined using the [sqlite3_blob_bytes()] interface. 5865 ** 5866 ** ^An attempt to read from an expired [BLOB handle] fails with an 5867 ** error code of [SQLITE_ABORT]. 5868 ** 5869 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 5870 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 5871 ** 5872 ** This routine only works on a [BLOB handle] which has been created 5873 ** by a prior successful call to [sqlite3_blob_open()] and which has not 5874 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5875 ** to this routine results in undefined and probably undesirable behavior. 5876 ** 5877 ** See also: [sqlite3_blob_write()]. 5878 */ 5879 SQLITE_API int SQLITE_STDCALL sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 5880 5881 /* 5882 ** CAPI3REF: Write Data Into A BLOB Incrementally 5883 ** 5884 ** ^(This function is used to write data into an open [BLOB handle] from a 5885 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 5886 ** into the open BLOB, starting at offset iOffset.)^ 5887 ** 5888 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 5889 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 5890 ** ^Unless SQLITE_MISUSE is returned, this function sets the 5891 ** [database connection] error code and message accessible via 5892 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 5893 ** 5894 ** ^If the [BLOB handle] passed as the first argument was not opened for 5895 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 5896 ** this function returns [SQLITE_READONLY]. 5897 ** 5898 ** This function may only modify the contents of the BLOB; it is 5899 ** not possible to increase the size of a BLOB using this API. 5900 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 5901 ** [SQLITE_ERROR] is returned and no data is written. The size of the 5902 ** BLOB (and hence the maximum value of N+iOffset) can be determined 5903 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 5904 ** than zero [SQLITE_ERROR] is returned and no data is written. 5905 ** 5906 ** ^An attempt to write to an expired [BLOB handle] fails with an 5907 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 5908 ** before the [BLOB handle] expired are not rolled back by the 5909 ** expiration of the handle, though of course those changes might 5910 ** have been overwritten by the statement that expired the BLOB handle 5911 ** or by other independent statements. 5912 ** 5913 ** This routine only works on a [BLOB handle] which has been created 5914 ** by a prior successful call to [sqlite3_blob_open()] and which has not 5915 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5916 ** to this routine results in undefined and probably undesirable behavior. 5917 ** 5918 ** See also: [sqlite3_blob_read()]. 5919 */ 5920 SQLITE_API int SQLITE_STDCALL sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 5921 5922 /* 5923 ** CAPI3REF: Virtual File System Objects 5924 ** 5925 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 5926 ** that SQLite uses to interact 5927 ** with the underlying operating system. Most SQLite builds come with a 5928 ** single default VFS that is appropriate for the host computer. 5929 ** New VFSes can be registered and existing VFSes can be unregistered. 5930 ** The following interfaces are provided. 5931 ** 5932 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 5933 ** ^Names are case sensitive. 5934 ** ^Names are zero-terminated UTF-8 strings. 5935 ** ^If there is no match, a NULL pointer is returned. 5936 ** ^If zVfsName is NULL then the default VFS is returned. 5937 ** 5938 ** ^New VFSes are registered with sqlite3_vfs_register(). 5939 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 5940 ** ^The same VFS can be registered multiple times without injury. 5941 ** ^To make an existing VFS into the default VFS, register it again 5942 ** with the makeDflt flag set. If two different VFSes with the 5943 ** same name are registered, the behavior is undefined. If a 5944 ** VFS is registered with a name that is NULL or an empty string, 5945 ** then the behavior is undefined. 5946 ** 5947 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 5948 ** ^(If the default VFS is unregistered, another VFS is chosen as 5949 ** the default. The choice for the new VFS is arbitrary.)^ 5950 */ 5951 SQLITE_API sqlite3_vfs *SQLITE_STDCALL sqlite3_vfs_find(const char *zVfsName); 5952 SQLITE_API int SQLITE_STDCALL sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 5953 SQLITE_API int SQLITE_STDCALL sqlite3_vfs_unregister(sqlite3_vfs*); 5954 5955 /* 5956 ** CAPI3REF: Mutexes 5957 ** 5958 ** The SQLite core uses these routines for thread 5959 ** synchronization. Though they are intended for internal 5960 ** use by SQLite, code that links against SQLite is 5961 ** permitted to use any of these routines. 5962 ** 5963 ** The SQLite source code contains multiple implementations 5964 ** of these mutex routines. An appropriate implementation 5965 ** is selected automatically at compile-time. The following 5966 ** implementations are available in the SQLite core: 5967 ** 5968 ** <ul> 5969 ** <li> SQLITE_MUTEX_PTHREADS 5970 ** <li> SQLITE_MUTEX_W32 5971 ** <li> SQLITE_MUTEX_NOOP 5972 ** </ul> 5973 ** 5974 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 5975 ** that does no real locking and is appropriate for use in 5976 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 5977 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 5978 ** and Windows. 5979 ** 5980 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 5981 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 5982 ** implementation is included with the library. In this case the 5983 ** application must supply a custom mutex implementation using the 5984 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 5985 ** before calling sqlite3_initialize() or any other public sqlite3_ 5986 ** function that calls sqlite3_initialize(). 5987 ** 5988 ** ^The sqlite3_mutex_alloc() routine allocates a new 5989 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 5990 ** routine returns NULL if it is unable to allocate the requested 5991 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 5992 ** integer constants: 5993 ** 5994 ** <ul> 5995 ** <li> SQLITE_MUTEX_FAST 5996 ** <li> SQLITE_MUTEX_RECURSIVE 5997 ** <li> SQLITE_MUTEX_STATIC_MASTER 5998 ** <li> SQLITE_MUTEX_STATIC_MEM 5999 ** <li> SQLITE_MUTEX_STATIC_OPEN 6000 ** <li> SQLITE_MUTEX_STATIC_PRNG 6001 ** <li> SQLITE_MUTEX_STATIC_LRU 6002 ** <li> SQLITE_MUTEX_STATIC_PMEM 6003 ** <li> SQLITE_MUTEX_STATIC_APP1 6004 ** <li> SQLITE_MUTEX_STATIC_APP2 6005 ** <li> SQLITE_MUTEX_STATIC_APP3 6006 ** </ul> 6007 ** 6008 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6009 ** cause sqlite3_mutex_alloc() to create 6010 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6011 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6012 ** The mutex implementation does not need to make a distinction 6013 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6014 ** not want to. SQLite will only request a recursive mutex in 6015 ** cases where it really needs one. If a faster non-recursive mutex 6016 ** implementation is available on the host platform, the mutex subsystem 6017 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 6018 ** 6019 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6020 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6021 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 6022 ** used by the current version of SQLite. Future versions of SQLite 6023 ** may add additional static mutexes. Static mutexes are for internal 6024 ** use by SQLite only. Applications that use SQLite mutexes should 6025 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6026 ** SQLITE_MUTEX_RECURSIVE. 6027 ** 6028 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6029 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6030 ** returns a different mutex on every call. ^For the static 6031 ** mutex types, the same mutex is returned on every call that has 6032 ** the same type number. 6033 ** 6034 ** ^The sqlite3_mutex_free() routine deallocates a previously 6035 ** allocated dynamic mutex. Attempting to deallocate a static 6036 ** mutex results in undefined behavior. 6037 ** 6038 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6039 ** to enter a mutex. ^If another thread is already within the mutex, 6040 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6041 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6042 ** upon successful entry. ^(Mutexes created using 6043 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6044 ** In such cases, the 6045 ** mutex must be exited an equal number of times before another thread 6046 ** can enter.)^ If the same thread tries to enter any mutex other 6047 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6048 ** 6049 ** ^(Some systems (for example, Windows 95) do not support the operation 6050 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6051 ** will always return SQLITE_BUSY. The SQLite core only ever uses 6052 ** sqlite3_mutex_try() as an optimization so this is acceptable 6053 ** behavior.)^ 6054 ** 6055 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 6056 ** previously entered by the same thread. The behavior 6057 ** is undefined if the mutex is not currently entered by the 6058 ** calling thread or is not currently allocated. 6059 ** 6060 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6061 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6062 ** behave as no-ops. 6063 ** 6064 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6065 */ 6066 SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_mutex_alloc(int); 6067 SQLITE_API void SQLITE_STDCALL sqlite3_mutex_free(sqlite3_mutex*); 6068 SQLITE_API void SQLITE_STDCALL sqlite3_mutex_enter(sqlite3_mutex*); 6069 SQLITE_API int SQLITE_STDCALL sqlite3_mutex_try(sqlite3_mutex*); 6070 SQLITE_API void SQLITE_STDCALL sqlite3_mutex_leave(sqlite3_mutex*); 6071 6072 /* 6073 ** CAPI3REF: Mutex Methods Object 6074 ** 6075 ** An instance of this structure defines the low-level routines 6076 ** used to allocate and use mutexes. 6077 ** 6078 ** Usually, the default mutex implementations provided by SQLite are 6079 ** sufficient, however the application has the option of substituting a custom 6080 ** implementation for specialized deployments or systems for which SQLite 6081 ** does not provide a suitable implementation. In this case, the application 6082 ** creates and populates an instance of this structure to pass 6083 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6084 ** Additionally, an instance of this structure can be used as an 6085 ** output variable when querying the system for the current mutex 6086 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6087 ** 6088 ** ^The xMutexInit method defined by this structure is invoked as 6089 ** part of system initialization by the sqlite3_initialize() function. 6090 ** ^The xMutexInit routine is called by SQLite exactly once for each 6091 ** effective call to [sqlite3_initialize()]. 6092 ** 6093 ** ^The xMutexEnd method defined by this structure is invoked as 6094 ** part of system shutdown by the sqlite3_shutdown() function. The 6095 ** implementation of this method is expected to release all outstanding 6096 ** resources obtained by the mutex methods implementation, especially 6097 ** those obtained by the xMutexInit method. ^The xMutexEnd() 6098 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6099 ** 6100 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6101 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6102 ** xMutexNotheld) implement the following interfaces (respectively): 6103 ** 6104 ** <ul> 6105 ** <li> [sqlite3_mutex_alloc()] </li> 6106 ** <li> [sqlite3_mutex_free()] </li> 6107 ** <li> [sqlite3_mutex_enter()] </li> 6108 ** <li> [sqlite3_mutex_try()] </li> 6109 ** <li> [sqlite3_mutex_leave()] </li> 6110 ** <li> [sqlite3_mutex_held()] </li> 6111 ** <li> [sqlite3_mutex_notheld()] </li> 6112 ** </ul>)^ 6113 ** 6114 ** The only difference is that the public sqlite3_XXX functions enumerated 6115 ** above silently ignore any invocations that pass a NULL pointer instead 6116 ** of a valid mutex handle. The implementations of the methods defined 6117 ** by this structure are not required to handle this case, the results 6118 ** of passing a NULL pointer instead of a valid mutex handle are undefined 6119 ** (i.e. it is acceptable to provide an implementation that segfaults if 6120 ** it is passed a NULL pointer). 6121 ** 6122 ** The xMutexInit() method must be threadsafe. It must be harmless to 6123 ** invoke xMutexInit() multiple times within the same process and without 6124 ** intervening calls to xMutexEnd(). Second and subsequent calls to 6125 ** xMutexInit() must be no-ops. 6126 ** 6127 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6128 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 6129 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6130 ** memory allocation for a fast or recursive mutex. 6131 ** 6132 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6133 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6134 ** If xMutexInit fails in any way, it is expected to clean up after itself 6135 ** prior to returning. 6136 */ 6137 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6138 struct sqlite3_mutex_methods { 6139 int (*xMutexInit)(void); 6140 int (*xMutexEnd)(void); 6141 sqlite3_mutex *(*xMutexAlloc)(int); 6142 void (*xMutexFree)(sqlite3_mutex *); 6143 void (*xMutexEnter)(sqlite3_mutex *); 6144 int (*xMutexTry)(sqlite3_mutex *); 6145 void (*xMutexLeave)(sqlite3_mutex *); 6146 int (*xMutexHeld)(sqlite3_mutex *); 6147 int (*xMutexNotheld)(sqlite3_mutex *); 6148 }; 6149 6150 /* 6151 ** CAPI3REF: Mutex Verification Routines 6152 ** 6153 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6154 ** are intended for use inside assert() statements. The SQLite core 6155 ** never uses these routines except inside an assert() and applications 6156 ** are advised to follow the lead of the core. The SQLite core only 6157 ** provides implementations for these routines when it is compiled 6158 ** with the SQLITE_DEBUG flag. External mutex implementations 6159 ** are only required to provide these routines if SQLITE_DEBUG is 6160 ** defined and if NDEBUG is not defined. 6161 ** 6162 ** These routines should return true if the mutex in their argument 6163 ** is held or not held, respectively, by the calling thread. 6164 ** 6165 ** The implementation is not required to provide versions of these 6166 ** routines that actually work. If the implementation does not provide working 6167 ** versions of these routines, it should at least provide stubs that always 6168 ** return true so that one does not get spurious assertion failures. 6169 ** 6170 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 6171 ** the routine should return 1. This seems counter-intuitive since 6172 ** clearly the mutex cannot be held if it does not exist. But 6173 ** the reason the mutex does not exist is because the build is not 6174 ** using mutexes. And we do not want the assert() containing the 6175 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 6176 ** the appropriate thing to do. The sqlite3_mutex_notheld() 6177 ** interface should also return 1 when given a NULL pointer. 6178 */ 6179 #ifndef NDEBUG 6180 SQLITE_API int SQLITE_STDCALL sqlite3_mutex_held(sqlite3_mutex*); 6181 SQLITE_API int SQLITE_STDCALL sqlite3_mutex_notheld(sqlite3_mutex*); 6182 #endif 6183 6184 /* 6185 ** CAPI3REF: Mutex Types 6186 ** 6187 ** The [sqlite3_mutex_alloc()] interface takes a single argument 6188 ** which is one of these integer constants. 6189 ** 6190 ** The set of static mutexes may change from one SQLite release to the 6191 ** next. Applications that override the built-in mutex logic must be 6192 ** prepared to accommodate additional static mutexes. 6193 */ 6194 #define SQLITE_MUTEX_FAST 0 6195 #define SQLITE_MUTEX_RECURSIVE 1 6196 #define SQLITE_MUTEX_STATIC_MASTER 2 6197 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6198 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6199 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6200 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 6201 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6202 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6203 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6204 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6205 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6206 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6207 6208 /* 6209 ** CAPI3REF: Retrieve the mutex for a database connection 6210 ** 6211 ** ^This interface returns a pointer the [sqlite3_mutex] object that 6212 ** serializes access to the [database connection] given in the argument 6213 ** when the [threading mode] is Serialized. 6214 ** ^If the [threading mode] is Single-thread or Multi-thread then this 6215 ** routine returns a NULL pointer. 6216 */ 6217 SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_db_mutex(sqlite3*); 6218 6219 /* 6220 ** CAPI3REF: Low-Level Control Of Database Files 6221 ** 6222 ** ^The [sqlite3_file_control()] interface makes a direct call to the 6223 ** xFileControl method for the [sqlite3_io_methods] object associated 6224 ** with a particular database identified by the second argument. ^The 6225 ** name of the database is "main" for the main database or "temp" for the 6226 ** TEMP database, or the name that appears after the AS keyword for 6227 ** databases that are added using the [ATTACH] SQL command. 6228 ** ^A NULL pointer can be used in place of "main" to refer to the 6229 ** main database file. 6230 ** ^The third and fourth parameters to this routine 6231 ** are passed directly through to the second and third parameters of 6232 ** the xFileControl method. ^The return value of the xFileControl 6233 ** method becomes the return value of this routine. 6234 ** 6235 ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6236 ** a pointer to the underlying [sqlite3_file] object to be written into 6237 ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6238 ** case is a short-circuit path which does not actually invoke the 6239 ** underlying sqlite3_io_methods.xFileControl method. 6240 ** 6241 ** ^If the second parameter (zDbName) does not match the name of any 6242 ** open database file, then SQLITE_ERROR is returned. ^This error 6243 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 6244 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 6245 ** also return SQLITE_ERROR. There is no way to distinguish between 6246 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6247 ** xFileControl method. 6248 ** 6249 ** See also: [SQLITE_FCNTL_LOCKSTATE] 6250 */ 6251 SQLITE_API int SQLITE_STDCALL sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6252 6253 /* 6254 ** CAPI3REF: Testing Interface 6255 ** 6256 ** ^The sqlite3_test_control() interface is used to read out internal 6257 ** state of SQLite and to inject faults into SQLite for testing 6258 ** purposes. ^The first parameter is an operation code that determines 6259 ** the number, meaning, and operation of all subsequent parameters. 6260 ** 6261 ** This interface is not for use by applications. It exists solely 6262 ** for verifying the correct operation of the SQLite library. Depending 6263 ** on how the SQLite library is compiled, this interface might not exist. 6264 ** 6265 ** The details of the operation codes, their meanings, the parameters 6266 ** they take, and what they do are all subject to change without notice. 6267 ** Unlike most of the SQLite API, this function is not guaranteed to 6268 ** operate consistently from one release to the next. 6269 */ 6270 SQLITE_API int SQLITE_CDECL sqlite3_test_control(int op, ...); 6271 6272 /* 6273 ** CAPI3REF: Testing Interface Operation Codes 6274 ** 6275 ** These constants are the valid operation code parameters used 6276 ** as the first argument to [sqlite3_test_control()]. 6277 ** 6278 ** These parameters and their meanings are subject to change 6279 ** without notice. These values are for testing purposes only. 6280 ** Applications should not use any of these parameters or the 6281 ** [sqlite3_test_control()] interface. 6282 */ 6283 #define SQLITE_TESTCTRL_FIRST 5 6284 #define SQLITE_TESTCTRL_PRNG_SAVE 5 6285 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 6286 #define SQLITE_TESTCTRL_PRNG_RESET 7 6287 #define SQLITE_TESTCTRL_BITVEC_TEST 8 6288 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 6289 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6290 #define SQLITE_TESTCTRL_PENDING_BYTE 11 6291 #define SQLITE_TESTCTRL_ASSERT 12 6292 #define SQLITE_TESTCTRL_ALWAYS 13 6293 #define SQLITE_TESTCTRL_RESERVE 14 6294 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 6295 #define SQLITE_TESTCTRL_ISKEYWORD 16 6296 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6297 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6298 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 6299 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 6300 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 6301 #define SQLITE_TESTCTRL_BYTEORDER 22 6302 #define SQLITE_TESTCTRL_ISINIT 23 6303 #define SQLITE_TESTCTRL_SORTER_MMAP 24 6304 #define SQLITE_TESTCTRL_IMPOSTER 25 6305 #define SQLITE_TESTCTRL_LAST 25 6306 6307 /* 6308 ** CAPI3REF: SQLite Runtime Status 6309 ** 6310 ** ^These interfaces are used to retrieve runtime status information 6311 ** about the performance of SQLite, and optionally to reset various 6312 ** highwater marks. ^The first argument is an integer code for 6313 ** the specific parameter to measure. ^(Recognized integer codes 6314 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 6315 ** ^The current value of the parameter is returned into *pCurrent. 6316 ** ^The highest recorded value is returned in *pHighwater. ^If the 6317 ** resetFlag is true, then the highest record value is reset after 6318 ** *pHighwater is written. ^(Some parameters do not record the highest 6319 ** value. For those parameters 6320 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6321 ** ^(Other parameters record only the highwater mark and not the current 6322 ** value. For these latter parameters nothing is written into *pCurrent.)^ 6323 ** 6324 ** ^The sqlite3_status() and sqlite3_status64() routines return 6325 ** SQLITE_OK on success and a non-zero [error code] on failure. 6326 ** 6327 ** If either the current value or the highwater mark is too large to 6328 ** be represented by a 32-bit integer, then the values returned by 6329 ** sqlite3_status() are undefined. 6330 ** 6331 ** See also: [sqlite3_db_status()] 6332 */ 6333 SQLITE_API int SQLITE_STDCALL sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6334 SQLITE_API int SQLITE_STDCALL sqlite3_status64( 6335 int op, 6336 sqlite3_int64 *pCurrent, 6337 sqlite3_int64 *pHighwater, 6338 int resetFlag 6339 ); 6340 6341 6342 /* 6343 ** CAPI3REF: Status Parameters 6344 ** KEYWORDS: {status parameters} 6345 ** 6346 ** These integer constants designate various run-time status parameters 6347 ** that can be returned by [sqlite3_status()]. 6348 ** 6349 ** <dl> 6350 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6351 ** <dd>This parameter is the current amount of memory checked out 6352 ** using [sqlite3_malloc()], either directly or indirectly. The 6353 ** figure includes calls made to [sqlite3_malloc()] by the application 6354 ** and internal memory usage by the SQLite library. Scratch memory 6355 ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6356 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6357 ** this parameter. The amount returned is the sum of the allocation 6358 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6359 ** 6360 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6361 ** <dd>This parameter records the largest memory allocation request 6362 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6363 ** internal equivalents). Only the value returned in the 6364 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6365 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6366 ** 6367 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6368 ** <dd>This parameter records the number of separate memory allocations 6369 ** currently checked out.</dd>)^ 6370 ** 6371 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6372 ** <dd>This parameter returns the number of pages used out of the 6373 ** [pagecache memory allocator] that was configured using 6374 ** [SQLITE_CONFIG_PAGECACHE]. The 6375 ** value returned is in pages, not in bytes.</dd>)^ 6376 ** 6377 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6378 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6379 ** <dd>This parameter returns the number of bytes of page cache 6380 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6381 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 6382 ** returned value includes allocations that overflowed because they 6383 ** where too large (they were larger than the "sz" parameter to 6384 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6385 ** no space was left in the page cache.</dd>)^ 6386 ** 6387 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6388 ** <dd>This parameter records the largest memory allocation request 6389 ** handed to [pagecache memory allocator]. Only the value returned in the 6390 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6391 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6392 ** 6393 ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6394 ** <dd>This parameter returns the number of allocations used out of the 6395 ** [scratch memory allocator] configured using 6396 ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6397 ** in bytes. Since a single thread may only have one scratch allocation 6398 ** outstanding at time, this parameter also reports the number of threads 6399 ** using scratch memory at the same time.</dd>)^ 6400 ** 6401 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6402 ** <dd>This parameter returns the number of bytes of scratch memory 6403 ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6404 ** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6405 ** returned include overflows because the requested allocation was too 6406 ** larger (that is, because the requested allocation was larger than the 6407 ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6408 ** slots were available. 6409 ** </dd>)^ 6410 ** 6411 ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6412 ** <dd>This parameter records the largest memory allocation request 6413 ** handed to [scratch memory allocator]. Only the value returned in the 6414 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6415 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6416 ** 6417 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6418 ** <dd>This parameter records the deepest parser stack. It is only 6419 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6420 ** </dl> 6421 ** 6422 ** New status parameters may be added from time to time. 6423 */ 6424 #define SQLITE_STATUS_MEMORY_USED 0 6425 #define SQLITE_STATUS_PAGECACHE_USED 1 6426 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6427 #define SQLITE_STATUS_SCRATCH_USED 3 6428 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6429 #define SQLITE_STATUS_MALLOC_SIZE 5 6430 #define SQLITE_STATUS_PARSER_STACK 6 6431 #define SQLITE_STATUS_PAGECACHE_SIZE 7 6432 #define SQLITE_STATUS_SCRATCH_SIZE 8 6433 #define SQLITE_STATUS_MALLOC_COUNT 9 6434 6435 /* 6436 ** CAPI3REF: Database Connection Status 6437 ** 6438 ** ^This interface is used to retrieve runtime status information 6439 ** about a single [database connection]. ^The first argument is the 6440 ** database connection object to be interrogated. ^The second argument 6441 ** is an integer constant, taken from the set of 6442 ** [SQLITE_DBSTATUS options], that 6443 ** determines the parameter to interrogate. The set of 6444 ** [SQLITE_DBSTATUS options] is likely 6445 ** to grow in future releases of SQLite. 6446 ** 6447 ** ^The current value of the requested parameter is written into *pCur 6448 ** and the highest instantaneous value is written into *pHiwtr. ^If 6449 ** the resetFlg is true, then the highest instantaneous value is 6450 ** reset back down to the current value. 6451 ** 6452 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6453 ** non-zero [error code] on failure. 6454 ** 6455 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6456 */ 6457 SQLITE_API int SQLITE_STDCALL sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6458 6459 /* 6460 ** CAPI3REF: Status Parameters for database connections 6461 ** KEYWORDS: {SQLITE_DBSTATUS options} 6462 ** 6463 ** These constants are the available integer "verbs" that can be passed as 6464 ** the second argument to the [sqlite3_db_status()] interface. 6465 ** 6466 ** New verbs may be added in future releases of SQLite. Existing verbs 6467 ** might be discontinued. Applications should check the return code from 6468 ** [sqlite3_db_status()] to make sure that the call worked. 6469 ** The [sqlite3_db_status()] interface will return a non-zero error code 6470 ** if a discontinued or unsupported verb is invoked. 6471 ** 6472 ** <dl> 6473 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6474 ** <dd>This parameter returns the number of lookaside memory slots currently 6475 ** checked out.</dd>)^ 6476 ** 6477 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6478 ** <dd>This parameter returns the number malloc attempts that were 6479 ** satisfied using lookaside memory. Only the high-water value is meaningful; 6480 ** the current value is always zero.)^ 6481 ** 6482 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6483 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6484 ** <dd>This parameter returns the number malloc attempts that might have 6485 ** been satisfied using lookaside memory but failed due to the amount of 6486 ** memory requested being larger than the lookaside slot size. 6487 ** Only the high-water value is meaningful; 6488 ** the current value is always zero.)^ 6489 ** 6490 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6491 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6492 ** <dd>This parameter returns the number malloc attempts that might have 6493 ** been satisfied using lookaside memory but failed due to all lookaside 6494 ** memory already being in use. 6495 ** Only the high-water value is meaningful; 6496 ** the current value is always zero.)^ 6497 ** 6498 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6499 ** <dd>This parameter returns the approximate number of bytes of heap 6500 ** memory used by all pager caches associated with the database connection.)^ 6501 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6502 ** 6503 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6504 ** <dd>This parameter returns the approximate number of bytes of heap 6505 ** memory used to store the schema for all databases associated 6506 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6507 ** ^The full amount of memory used by the schemas is reported, even if the 6508 ** schema memory is shared with other database connections due to 6509 ** [shared cache mode] being enabled. 6510 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6511 ** 6512 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6513 ** <dd>This parameter returns the approximate number of bytes of heap 6514 ** and lookaside memory used by all prepared statements associated with 6515 ** the database connection.)^ 6516 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6517 ** </dd> 6518 ** 6519 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6520 ** <dd>This parameter returns the number of pager cache hits that have 6521 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6522 ** is always 0. 6523 ** </dd> 6524 ** 6525 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6526 ** <dd>This parameter returns the number of pager cache misses that have 6527 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 6528 ** is always 0. 6529 ** </dd> 6530 ** 6531 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 6532 ** <dd>This parameter returns the number of dirty cache entries that have 6533 ** been written to disk. Specifically, the number of pages written to the 6534 ** wal file in wal mode databases, or the number of pages written to the 6535 ** database file in rollback mode databases. Any pages written as part of 6536 ** transaction rollback or database recovery operations are not included. 6537 ** If an IO or other error occurs while writing a page to disk, the effect 6538 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 6539 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 6540 ** </dd> 6541 ** 6542 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 6543 ** <dd>This parameter returns zero for the current value if and only if 6544 ** all foreign key constraints (deferred or immediate) have been 6545 ** resolved.)^ ^The highwater mark is always 0. 6546 ** </dd> 6547 ** </dl> 6548 */ 6549 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 6550 #define SQLITE_DBSTATUS_CACHE_USED 1 6551 #define SQLITE_DBSTATUS_SCHEMA_USED 2 6552 #define SQLITE_DBSTATUS_STMT_USED 3 6553 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 6554 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 6555 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 6556 #define SQLITE_DBSTATUS_CACHE_HIT 7 6557 #define SQLITE_DBSTATUS_CACHE_MISS 8 6558 #define SQLITE_DBSTATUS_CACHE_WRITE 9 6559 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 6560 #define SQLITE_DBSTATUS_MAX 10 /* Largest defined DBSTATUS */ 6561 6562 6563 /* 6564 ** CAPI3REF: Prepared Statement Status 6565 ** 6566 ** ^(Each prepared statement maintains various 6567 ** [SQLITE_STMTSTATUS counters] that measure the number 6568 ** of times it has performed specific operations.)^ These counters can 6569 ** be used to monitor the performance characteristics of the prepared 6570 ** statements. For example, if the number of table steps greatly exceeds 6571 ** the number of table searches or result rows, that would tend to indicate 6572 ** that the prepared statement is using a full table scan rather than 6573 ** an index. 6574 ** 6575 ** ^(This interface is used to retrieve and reset counter values from 6576 ** a [prepared statement]. The first argument is the prepared statement 6577 ** object to be interrogated. The second argument 6578 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 6579 ** to be interrogated.)^ 6580 ** ^The current value of the requested counter is returned. 6581 ** ^If the resetFlg is true, then the counter is reset to zero after this 6582 ** interface call returns. 6583 ** 6584 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 6585 */ 6586 SQLITE_API int SQLITE_STDCALL sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 6587 6588 /* 6589 ** CAPI3REF: Status Parameters for prepared statements 6590 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 6591 ** 6592 ** These preprocessor macros define integer codes that name counter 6593 ** values associated with the [sqlite3_stmt_status()] interface. 6594 ** The meanings of the various counters are as follows: 6595 ** 6596 ** <dl> 6597 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 6598 ** <dd>^This is the number of times that SQLite has stepped forward in 6599 ** a table as part of a full table scan. Large numbers for this counter 6600 ** may indicate opportunities for performance improvement through 6601 ** careful use of indices.</dd> 6602 ** 6603 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 6604 ** <dd>^This is the number of sort operations that have occurred. 6605 ** A non-zero value in this counter may indicate an opportunity to 6606 ** improvement performance through careful use of indices.</dd> 6607 ** 6608 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 6609 ** <dd>^This is the number of rows inserted into transient indices that 6610 ** were created automatically in order to help joins run faster. 6611 ** A non-zero value in this counter may indicate an opportunity to 6612 ** improvement performance by adding permanent indices that do not 6613 ** need to be reinitialized each time the statement is run.</dd> 6614 ** 6615 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 6616 ** <dd>^This is the number of virtual machine operations executed 6617 ** by the prepared statement if that number is less than or equal 6618 ** to 2147483647. The number of virtual machine operations can be 6619 ** used as a proxy for the total work done by the prepared statement. 6620 ** If the number of virtual machine operations exceeds 2147483647 6621 ** then the value returned by this statement status code is undefined. 6622 ** </dd> 6623 ** </dl> 6624 */ 6625 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 6626 #define SQLITE_STMTSTATUS_SORT 2 6627 #define SQLITE_STMTSTATUS_AUTOINDEX 3 6628 #define SQLITE_STMTSTATUS_VM_STEP 4 6629 6630 /* 6631 ** CAPI3REF: Custom Page Cache Object 6632 ** 6633 ** The sqlite3_pcache type is opaque. It is implemented by 6634 ** the pluggable module. The SQLite core has no knowledge of 6635 ** its size or internal structure and never deals with the 6636 ** sqlite3_pcache object except by holding and passing pointers 6637 ** to the object. 6638 ** 6639 ** See [sqlite3_pcache_methods2] for additional information. 6640 */ 6641 typedef struct sqlite3_pcache sqlite3_pcache; 6642 6643 /* 6644 ** CAPI3REF: Custom Page Cache Object 6645 ** 6646 ** The sqlite3_pcache_page object represents a single page in the 6647 ** page cache. The page cache will allocate instances of this 6648 ** object. Various methods of the page cache use pointers to instances 6649 ** of this object as parameters or as their return value. 6650 ** 6651 ** See [sqlite3_pcache_methods2] for additional information. 6652 */ 6653 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 6654 struct sqlite3_pcache_page { 6655 void *pBuf; /* The content of the page */ 6656 void *pExtra; /* Extra information associated with the page */ 6657 }; 6658 6659 /* 6660 ** CAPI3REF: Application Defined Page Cache. 6661 ** KEYWORDS: {page cache} 6662 ** 6663 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 6664 ** register an alternative page cache implementation by passing in an 6665 ** instance of the sqlite3_pcache_methods2 structure.)^ 6666 ** In many applications, most of the heap memory allocated by 6667 ** SQLite is used for the page cache. 6668 ** By implementing a 6669 ** custom page cache using this API, an application can better control 6670 ** the amount of memory consumed by SQLite, the way in which 6671 ** that memory is allocated and released, and the policies used to 6672 ** determine exactly which parts of a database file are cached and for 6673 ** how long. 6674 ** 6675 ** The alternative page cache mechanism is an 6676 ** extreme measure that is only needed by the most demanding applications. 6677 ** The built-in page cache is recommended for most uses. 6678 ** 6679 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 6680 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 6681 ** the application may discard the parameter after the call to 6682 ** [sqlite3_config()] returns.)^ 6683 ** 6684 ** [[the xInit() page cache method]] 6685 ** ^(The xInit() method is called once for each effective 6686 ** call to [sqlite3_initialize()])^ 6687 ** (usually only once during the lifetime of the process). ^(The xInit() 6688 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 6689 ** The intent of the xInit() method is to set up global data structures 6690 ** required by the custom page cache implementation. 6691 ** ^(If the xInit() method is NULL, then the 6692 ** built-in default page cache is used instead of the application defined 6693 ** page cache.)^ 6694 ** 6695 ** [[the xShutdown() page cache method]] 6696 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 6697 ** It can be used to clean up 6698 ** any outstanding resources before process shutdown, if required. 6699 ** ^The xShutdown() method may be NULL. 6700 ** 6701 ** ^SQLite automatically serializes calls to the xInit method, 6702 ** so the xInit method need not be threadsafe. ^The 6703 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 6704 ** not need to be threadsafe either. All other methods must be threadsafe 6705 ** in multithreaded applications. 6706 ** 6707 ** ^SQLite will never invoke xInit() more than once without an intervening 6708 ** call to xShutdown(). 6709 ** 6710 ** [[the xCreate() page cache methods]] 6711 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 6712 ** SQLite will typically create one cache instance for each open database file, 6713 ** though this is not guaranteed. ^The 6714 ** first parameter, szPage, is the size in bytes of the pages that must 6715 ** be allocated by the cache. ^szPage will always a power of two. ^The 6716 ** second parameter szExtra is a number of bytes of extra storage 6717 ** associated with each page cache entry. ^The szExtra parameter will 6718 ** a number less than 250. SQLite will use the 6719 ** extra szExtra bytes on each page to store metadata about the underlying 6720 ** database page on disk. The value passed into szExtra depends 6721 ** on the SQLite version, the target platform, and how SQLite was compiled. 6722 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 6723 ** created will be used to cache database pages of a file stored on disk, or 6724 ** false if it is used for an in-memory database. The cache implementation 6725 ** does not have to do anything special based with the value of bPurgeable; 6726 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 6727 ** never invoke xUnpin() except to deliberately delete a page. 6728 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 6729 ** false will always have the "discard" flag set to true. 6730 ** ^Hence, a cache created with bPurgeable false will 6731 ** never contain any unpinned pages. 6732 ** 6733 ** [[the xCachesize() page cache method]] 6734 ** ^(The xCachesize() method may be called at any time by SQLite to set the 6735 ** suggested maximum cache-size (number of pages stored by) the cache 6736 ** instance passed as the first argument. This is the value configured using 6737 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 6738 ** parameter, the implementation is not required to do anything with this 6739 ** value; it is advisory only. 6740 ** 6741 ** [[the xPagecount() page cache methods]] 6742 ** The xPagecount() method must return the number of pages currently 6743 ** stored in the cache, both pinned and unpinned. 6744 ** 6745 ** [[the xFetch() page cache methods]] 6746 ** The xFetch() method locates a page in the cache and returns a pointer to 6747 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 6748 ** The pBuf element of the returned sqlite3_pcache_page object will be a 6749 ** pointer to a buffer of szPage bytes used to store the content of a 6750 ** single database page. The pExtra element of sqlite3_pcache_page will be 6751 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 6752 ** for each entry in the page cache. 6753 ** 6754 ** The page to be fetched is determined by the key. ^The minimum key value 6755 ** is 1. After it has been retrieved using xFetch, the page is considered 6756 ** to be "pinned". 6757 ** 6758 ** If the requested page is already in the page cache, then the page cache 6759 ** implementation must return a pointer to the page buffer with its content 6760 ** intact. If the requested page is not already in the cache, then the 6761 ** cache implementation should use the value of the createFlag 6762 ** parameter to help it determined what action to take: 6763 ** 6764 ** <table border=1 width=85% align=center> 6765 ** <tr><th> createFlag <th> Behavior when page is not already in cache 6766 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 6767 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 6768 ** Otherwise return NULL. 6769 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 6770 ** NULL if allocating a new page is effectively impossible. 6771 ** </table> 6772 ** 6773 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 6774 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 6775 ** failed.)^ In between the to xFetch() calls, SQLite may 6776 ** attempt to unpin one or more cache pages by spilling the content of 6777 ** pinned pages to disk and synching the operating system disk cache. 6778 ** 6779 ** [[the xUnpin() page cache method]] 6780 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 6781 ** as its second argument. If the third parameter, discard, is non-zero, 6782 ** then the page must be evicted from the cache. 6783 ** ^If the discard parameter is 6784 ** zero, then the page may be discarded or retained at the discretion of 6785 ** page cache implementation. ^The page cache implementation 6786 ** may choose to evict unpinned pages at any time. 6787 ** 6788 ** The cache must not perform any reference counting. A single 6789 ** call to xUnpin() unpins the page regardless of the number of prior calls 6790 ** to xFetch(). 6791 ** 6792 ** [[the xRekey() page cache methods]] 6793 ** The xRekey() method is used to change the key value associated with the 6794 ** page passed as the second argument. If the cache 6795 ** previously contains an entry associated with newKey, it must be 6796 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 6797 ** to be pinned. 6798 ** 6799 ** When SQLite calls the xTruncate() method, the cache must discard all 6800 ** existing cache entries with page numbers (keys) greater than or equal 6801 ** to the value of the iLimit parameter passed to xTruncate(). If any 6802 ** of these pages are pinned, they are implicitly unpinned, meaning that 6803 ** they can be safely discarded. 6804 ** 6805 ** [[the xDestroy() page cache method]] 6806 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 6807 ** All resources associated with the specified cache should be freed. ^After 6808 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 6809 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 6810 ** functions. 6811 ** 6812 ** [[the xShrink() page cache method]] 6813 ** ^SQLite invokes the xShrink() method when it wants the page cache to 6814 ** free up as much of heap memory as possible. The page cache implementation 6815 ** is not obligated to free any memory, but well-behaved implementations should 6816 ** do their best. 6817 */ 6818 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 6819 struct sqlite3_pcache_methods2 { 6820 int iVersion; 6821 void *pArg; 6822 int (*xInit)(void*); 6823 void (*xShutdown)(void*); 6824 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 6825 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6826 int (*xPagecount)(sqlite3_pcache*); 6827 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6828 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 6829 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 6830 unsigned oldKey, unsigned newKey); 6831 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6832 void (*xDestroy)(sqlite3_pcache*); 6833 void (*xShrink)(sqlite3_pcache*); 6834 }; 6835 6836 /* 6837 ** This is the obsolete pcache_methods object that has now been replaced 6838 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 6839 ** retained in the header file for backwards compatibility only. 6840 */ 6841 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 6842 struct sqlite3_pcache_methods { 6843 void *pArg; 6844 int (*xInit)(void*); 6845 void (*xShutdown)(void*); 6846 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 6847 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6848 int (*xPagecount)(sqlite3_pcache*); 6849 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6850 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 6851 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 6852 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6853 void (*xDestroy)(sqlite3_pcache*); 6854 }; 6855 6856 6857 /* 6858 ** CAPI3REF: Online Backup Object 6859 ** 6860 ** The sqlite3_backup object records state information about an ongoing 6861 ** online backup operation. ^The sqlite3_backup object is created by 6862 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 6863 ** [sqlite3_backup_finish()]. 6864 ** 6865 ** See Also: [Using the SQLite Online Backup API] 6866 */ 6867 typedef struct sqlite3_backup sqlite3_backup; 6868 6869 /* 6870 ** CAPI3REF: Online Backup API. 6871 ** 6872 ** The backup API copies the content of one database into another. 6873 ** It is useful either for creating backups of databases or 6874 ** for copying in-memory databases to or from persistent files. 6875 ** 6876 ** See Also: [Using the SQLite Online Backup API] 6877 ** 6878 ** ^SQLite holds a write transaction open on the destination database file 6879 ** for the duration of the backup operation. 6880 ** ^The source database is read-locked only while it is being read; 6881 ** it is not locked continuously for the entire backup operation. 6882 ** ^Thus, the backup may be performed on a live source database without 6883 ** preventing other database connections from 6884 ** reading or writing to the source database while the backup is underway. 6885 ** 6886 ** ^(To perform a backup operation: 6887 ** <ol> 6888 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 6889 ** backup, 6890 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 6891 ** the data between the two databases, and finally 6892 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 6893 ** associated with the backup operation. 6894 ** </ol>)^ 6895 ** There should be exactly one call to sqlite3_backup_finish() for each 6896 ** successful call to sqlite3_backup_init(). 6897 ** 6898 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 6899 ** 6900 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 6901 ** [database connection] associated with the destination database 6902 ** and the database name, respectively. 6903 ** ^The database name is "main" for the main database, "temp" for the 6904 ** temporary database, or the name specified after the AS keyword in 6905 ** an [ATTACH] statement for an attached database. 6906 ** ^The S and M arguments passed to 6907 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 6908 ** and database name of the source database, respectively. 6909 ** ^The source and destination [database connections] (parameters S and D) 6910 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 6911 ** an error. 6912 ** 6913 ** ^A call to sqlite3_backup_init() will fail, returning SQLITE_ERROR, if 6914 ** there is already a read or read-write transaction open on the 6915 ** destination database. 6916 ** 6917 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 6918 ** returned and an error code and error message are stored in the 6919 ** destination [database connection] D. 6920 ** ^The error code and message for the failed call to sqlite3_backup_init() 6921 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 6922 ** [sqlite3_errmsg16()] functions. 6923 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 6924 ** [sqlite3_backup] object. 6925 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 6926 ** sqlite3_backup_finish() functions to perform the specified backup 6927 ** operation. 6928 ** 6929 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 6930 ** 6931 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 6932 ** the source and destination databases specified by [sqlite3_backup] object B. 6933 ** ^If N is negative, all remaining source pages are copied. 6934 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 6935 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 6936 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 6937 ** from source to destination, then it returns [SQLITE_DONE]. 6938 ** ^If an error occurs while running sqlite3_backup_step(B,N), 6939 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 6940 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 6941 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 6942 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 6943 ** 6944 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 6945 ** <ol> 6946 ** <li> the destination database was opened read-only, or 6947 ** <li> the destination database is using write-ahead-log journaling 6948 ** and the destination and source page sizes differ, or 6949 ** <li> the destination database is an in-memory database and the 6950 ** destination and source page sizes differ. 6951 ** </ol>)^ 6952 ** 6953 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 6954 ** the [sqlite3_busy_handler | busy-handler function] 6955 ** is invoked (if one is specified). ^If the 6956 ** busy-handler returns non-zero before the lock is available, then 6957 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 6958 ** sqlite3_backup_step() can be retried later. ^If the source 6959 ** [database connection] 6960 ** is being used to write to the source database when sqlite3_backup_step() 6961 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 6962 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 6963 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 6964 ** [SQLITE_READONLY] is returned, then 6965 ** there is no point in retrying the call to sqlite3_backup_step(). These 6966 ** errors are considered fatal.)^ The application must accept 6967 ** that the backup operation has failed and pass the backup operation handle 6968 ** to the sqlite3_backup_finish() to release associated resources. 6969 ** 6970 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 6971 ** on the destination file. ^The exclusive lock is not released until either 6972 ** sqlite3_backup_finish() is called or the backup operation is complete 6973 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 6974 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 6975 ** lasts for the duration of the sqlite3_backup_step() call. 6976 ** ^Because the source database is not locked between calls to 6977 ** sqlite3_backup_step(), the source database may be modified mid-way 6978 ** through the backup process. ^If the source database is modified by an 6979 ** external process or via a database connection other than the one being 6980 ** used by the backup operation, then the backup will be automatically 6981 ** restarted by the next call to sqlite3_backup_step(). ^If the source 6982 ** database is modified by the using the same database connection as is used 6983 ** by the backup operation, then the backup database is automatically 6984 ** updated at the same time. 6985 ** 6986 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 6987 ** 6988 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 6989 ** application wishes to abandon the backup operation, the application 6990 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 6991 ** ^The sqlite3_backup_finish() interfaces releases all 6992 ** resources associated with the [sqlite3_backup] object. 6993 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 6994 ** active write-transaction on the destination database is rolled back. 6995 ** The [sqlite3_backup] object is invalid 6996 ** and may not be used following a call to sqlite3_backup_finish(). 6997 ** 6998 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 6999 ** sqlite3_backup_step() errors occurred, regardless or whether or not 7000 ** sqlite3_backup_step() completed. 7001 ** ^If an out-of-memory condition or IO error occurred during any prior 7002 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 7003 ** sqlite3_backup_finish() returns the corresponding [error code]. 7004 ** 7005 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 7006 ** is not a permanent error and does not affect the return value of 7007 ** sqlite3_backup_finish(). 7008 ** 7009 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 7010 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 7011 ** 7012 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 7013 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 7014 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 7015 ** in the source database at the conclusion of the most recent 7016 ** sqlite3_backup_step(). 7017 ** ^(The values returned by these functions are only updated by 7018 ** sqlite3_backup_step(). If the source database is modified in a way that 7019 ** changes the size of the source database or the number of pages remaining, 7020 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 7021 ** and sqlite3_backup_remaining() until after the next 7022 ** sqlite3_backup_step().)^ 7023 ** 7024 ** <b>Concurrent Usage of Database Handles</b> 7025 ** 7026 ** ^The source [database connection] may be used by the application for other 7027 ** purposes while a backup operation is underway or being initialized. 7028 ** ^If SQLite is compiled and configured to support threadsafe database 7029 ** connections, then the source database connection may be used concurrently 7030 ** from within other threads. 7031 ** 7032 ** However, the application must guarantee that the destination 7033 ** [database connection] is not passed to any other API (by any thread) after 7034 ** sqlite3_backup_init() is called and before the corresponding call to 7035 ** sqlite3_backup_finish(). SQLite does not currently check to see 7036 ** if the application incorrectly accesses the destination [database connection] 7037 ** and so no error code is reported, but the operations may malfunction 7038 ** nevertheless. Use of the destination database connection while a 7039 ** backup is in progress might also also cause a mutex deadlock. 7040 ** 7041 ** If running in [shared cache mode], the application must 7042 ** guarantee that the shared cache used by the destination database 7043 ** is not accessed while the backup is running. In practice this means 7044 ** that the application must guarantee that the disk file being 7045 ** backed up to is not accessed by any connection within the process, 7046 ** not just the specific connection that was passed to sqlite3_backup_init(). 7047 ** 7048 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 7049 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 7050 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 7051 ** APIs are not strictly speaking threadsafe. If they are invoked at the 7052 ** same time as another thread is invoking sqlite3_backup_step() it is 7053 ** possible that they return invalid values. 7054 */ 7055 SQLITE_API sqlite3_backup *SQLITE_STDCALL sqlite3_backup_init( 7056 sqlite3 *pDest, /* Destination database handle */ 7057 const char *zDestName, /* Destination database name */ 7058 sqlite3 *pSource, /* Source database handle */ 7059 const char *zSourceName /* Source database name */ 7060 ); 7061 SQLITE_API int SQLITE_STDCALL sqlite3_backup_step(sqlite3_backup *p, int nPage); 7062 SQLITE_API int SQLITE_STDCALL sqlite3_backup_finish(sqlite3_backup *p); 7063 SQLITE_API int SQLITE_STDCALL sqlite3_backup_remaining(sqlite3_backup *p); 7064 SQLITE_API int SQLITE_STDCALL sqlite3_backup_pagecount(sqlite3_backup *p); 7065 7066 /* 7067 ** CAPI3REF: Unlock Notification 7068 ** 7069 ** ^When running in shared-cache mode, a database operation may fail with 7070 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 7071 ** individual tables within the shared-cache cannot be obtained. See 7072 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 7073 ** ^This API may be used to register a callback that SQLite will invoke 7074 ** when the connection currently holding the required lock relinquishes it. 7075 ** ^This API is only available if the library was compiled with the 7076 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 7077 ** 7078 ** See Also: [Using the SQLite Unlock Notification Feature]. 7079 ** 7080 ** ^Shared-cache locks are released when a database connection concludes 7081 ** its current transaction, either by committing it or rolling it back. 7082 ** 7083 ** ^When a connection (known as the blocked connection) fails to obtain a 7084 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 7085 ** identity of the database connection (the blocking connection) that 7086 ** has locked the required resource is stored internally. ^After an 7087 ** application receives an SQLITE_LOCKED error, it may call the 7088 ** sqlite3_unlock_notify() method with the blocked connection handle as 7089 ** the first argument to register for a callback that will be invoked 7090 ** when the blocking connections current transaction is concluded. ^The 7091 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 7092 ** call that concludes the blocking connections transaction. 7093 ** 7094 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 7095 ** there is a chance that the blocking connection will have already 7096 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 7097 ** If this happens, then the specified callback is invoked immediately, 7098 ** from within the call to sqlite3_unlock_notify().)^ 7099 ** 7100 ** ^If the blocked connection is attempting to obtain a write-lock on a 7101 ** shared-cache table, and more than one other connection currently holds 7102 ** a read-lock on the same table, then SQLite arbitrarily selects one of 7103 ** the other connections to use as the blocking connection. 7104 ** 7105 ** ^(There may be at most one unlock-notify callback registered by a 7106 ** blocked connection. If sqlite3_unlock_notify() is called when the 7107 ** blocked connection already has a registered unlock-notify callback, 7108 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 7109 ** called with a NULL pointer as its second argument, then any existing 7110 ** unlock-notify callback is canceled. ^The blocked connections 7111 ** unlock-notify callback may also be canceled by closing the blocked 7112 ** connection using [sqlite3_close()]. 7113 ** 7114 ** The unlock-notify callback is not reentrant. If an application invokes 7115 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 7116 ** crash or deadlock may be the result. 7117 ** 7118 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 7119 ** returns SQLITE_OK. 7120 ** 7121 ** <b>Callback Invocation Details</b> 7122 ** 7123 ** When an unlock-notify callback is registered, the application provides a 7124 ** single void* pointer that is passed to the callback when it is invoked. 7125 ** However, the signature of the callback function allows SQLite to pass 7126 ** it an array of void* context pointers. The first argument passed to 7127 ** an unlock-notify callback is a pointer to an array of void* pointers, 7128 ** and the second is the number of entries in the array. 7129 ** 7130 ** When a blocking connections transaction is concluded, there may be 7131 ** more than one blocked connection that has registered for an unlock-notify 7132 ** callback. ^If two or more such blocked connections have specified the 7133 ** same callback function, then instead of invoking the callback function 7134 ** multiple times, it is invoked once with the set of void* context pointers 7135 ** specified by the blocked connections bundled together into an array. 7136 ** This gives the application an opportunity to prioritize any actions 7137 ** related to the set of unblocked database connections. 7138 ** 7139 ** <b>Deadlock Detection</b> 7140 ** 7141 ** Assuming that after registering for an unlock-notify callback a 7142 ** database waits for the callback to be issued before taking any further 7143 ** action (a reasonable assumption), then using this API may cause the 7144 ** application to deadlock. For example, if connection X is waiting for 7145 ** connection Y's transaction to be concluded, and similarly connection 7146 ** Y is waiting on connection X's transaction, then neither connection 7147 ** will proceed and the system may remain deadlocked indefinitely. 7148 ** 7149 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 7150 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 7151 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 7152 ** unlock-notify callback is registered. The system is said to be in 7153 ** a deadlocked state if connection A has registered for an unlock-notify 7154 ** callback on the conclusion of connection B's transaction, and connection 7155 ** B has itself registered for an unlock-notify callback when connection 7156 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 7157 ** the system is also considered to be deadlocked if connection B has 7158 ** registered for an unlock-notify callback on the conclusion of connection 7159 ** C's transaction, where connection C is waiting on connection A. ^Any 7160 ** number of levels of indirection are allowed. 7161 ** 7162 ** <b>The "DROP TABLE" Exception</b> 7163 ** 7164 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 7165 ** always appropriate to call sqlite3_unlock_notify(). There is however, 7166 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 7167 ** SQLite checks if there are any currently executing SELECT statements 7168 ** that belong to the same connection. If there are, SQLITE_LOCKED is 7169 ** returned. In this case there is no "blocking connection", so invoking 7170 ** sqlite3_unlock_notify() results in the unlock-notify callback being 7171 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 7172 ** or "DROP INDEX" query, an infinite loop might be the result. 7173 ** 7174 ** One way around this problem is to check the extended error code returned 7175 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 7176 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 7177 ** the special "DROP TABLE/INDEX" case, the extended error code is just 7178 ** SQLITE_LOCKED.)^ 7179 */ 7180 SQLITE_API int SQLITE_STDCALL sqlite3_unlock_notify( 7181 sqlite3 *pBlocked, /* Waiting connection */ 7182 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 7183 void *pNotifyArg /* Argument to pass to xNotify */ 7184 ); 7185 7186 7187 /* 7188 ** CAPI3REF: String Comparison 7189 ** 7190 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7191 ** and extensions to compare the contents of two buffers containing UTF-8 7192 ** strings in a case-independent fashion, using the same definition of "case 7193 ** independence" that SQLite uses internally when comparing identifiers. 7194 */ 7195 SQLITE_API int SQLITE_STDCALL sqlite3_stricmp(const char *, const char *); 7196 SQLITE_API int SQLITE_STDCALL sqlite3_strnicmp(const char *, const char *, int); 7197 7198 /* 7199 ** CAPI3REF: String Globbing 7200 * 7201 ** ^The [sqlite3_strglob(P,X)] interface returns zero if string X matches 7202 ** the glob pattern P, and it returns non-zero if string X does not match 7203 ** the glob pattern P. ^The definition of glob pattern matching used in 7204 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7205 ** SQL dialect used by SQLite. ^The sqlite3_strglob(P,X) function is case 7206 ** sensitive. 7207 ** 7208 ** Note that this routine returns zero on a match and non-zero if the strings 7209 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7210 */ 7211 SQLITE_API int SQLITE_STDCALL sqlite3_strglob(const char *zGlob, const char *zStr); 7212 7213 /* 7214 ** CAPI3REF: Error Logging Interface 7215 ** 7216 ** ^The [sqlite3_log()] interface writes a message into the [error log] 7217 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7218 ** ^If logging is enabled, the zFormat string and subsequent arguments are 7219 ** used with [sqlite3_snprintf()] to generate the final output string. 7220 ** 7221 ** The sqlite3_log() interface is intended for use by extensions such as 7222 ** virtual tables, collating functions, and SQL functions. While there is 7223 ** nothing to prevent an application from calling sqlite3_log(), doing so 7224 ** is considered bad form. 7225 ** 7226 ** The zFormat string must not be NULL. 7227 ** 7228 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7229 ** will not use dynamically allocated memory. The log message is stored in 7230 ** a fixed-length buffer on the stack. If the log message is longer than 7231 ** a few hundred characters, it will be truncated to the length of the 7232 ** buffer. 7233 */ 7234 SQLITE_API void SQLITE_CDECL sqlite3_log(int iErrCode, const char *zFormat, ...); 7235 7236 /* 7237 ** CAPI3REF: Write-Ahead Log Commit Hook 7238 ** 7239 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 7240 ** is invoked each time data is committed to a database in wal mode. 7241 ** 7242 ** ^(The callback is invoked by SQLite after the commit has taken place and 7243 ** the associated write-lock on the database released)^, so the implementation 7244 ** may read, write or [checkpoint] the database as required. 7245 ** 7246 ** ^The first parameter passed to the callback function when it is invoked 7247 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 7248 ** registering the callback. ^The second is a copy of the database handle. 7249 ** ^The third parameter is the name of the database that was written to - 7250 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 7251 ** is the number of pages currently in the write-ahead log file, 7252 ** including those that were just committed. 7253 ** 7254 ** The callback function should normally return [SQLITE_OK]. ^If an error 7255 ** code is returned, that error will propagate back up through the 7256 ** SQLite code base to cause the statement that provoked the callback 7257 ** to report an error, though the commit will have still occurred. If the 7258 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 7259 ** that does not correspond to any valid SQLite error code, the results 7260 ** are undefined. 7261 ** 7262 ** A single database handle may have at most a single write-ahead log callback 7263 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 7264 ** previously registered write-ahead log callback. ^Note that the 7265 ** [sqlite3_wal_autocheckpoint()] interface and the 7266 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 7267 ** those overwrite any prior [sqlite3_wal_hook()] settings. 7268 */ 7269 SQLITE_API void *SQLITE_STDCALL sqlite3_wal_hook( 7270 sqlite3*, 7271 int(*)(void *,sqlite3*,const char*,int), 7272 void* 7273 ); 7274 7275 /* 7276 ** CAPI3REF: Configure an auto-checkpoint 7277 ** 7278 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 7279 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 7280 ** to automatically [checkpoint] 7281 ** after committing a transaction if there are N or 7282 ** more frames in the [write-ahead log] file. ^Passing zero or 7283 ** a negative value as the nFrame parameter disables automatic 7284 ** checkpoints entirely. 7285 ** 7286 ** ^The callback registered by this function replaces any existing callback 7287 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 7288 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 7289 ** configured by this function. 7290 ** 7291 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 7292 ** from SQL. 7293 ** 7294 ** ^Checkpoints initiated by this mechanism are 7295 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 7296 ** 7297 ** ^Every new [database connection] defaults to having the auto-checkpoint 7298 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 7299 ** pages. The use of this interface 7300 ** is only necessary if the default setting is found to be suboptimal 7301 ** for a particular application. 7302 */ 7303 SQLITE_API int SQLITE_STDCALL sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 7304 7305 /* 7306 ** CAPI3REF: Checkpoint a database 7307 ** 7308 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 7309 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 7310 ** 7311 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 7312 ** [write-ahead log] for database X on [database connection] D to be 7313 ** transferred into the database file and for the write-ahead log to 7314 ** be reset. See the [checkpointing] documentation for addition 7315 ** information. 7316 ** 7317 ** This interface used to be the only way to cause a checkpoint to 7318 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 7319 ** interface was added. This interface is retained for backwards 7320 ** compatibility and as a convenience for applications that need to manually 7321 ** start a callback but which do not need the full power (and corresponding 7322 ** complication) of [sqlite3_wal_checkpoint_v2()]. 7323 */ 7324 SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 7325 7326 /* 7327 ** CAPI3REF: Checkpoint a database 7328 ** 7329 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 7330 ** operation on database X of [database connection] D in mode M. Status 7331 ** information is written back into integers pointed to by L and C.)^ 7332 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 7333 ** 7334 ** <dl> 7335 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7336 ** ^Checkpoint as many frames as possible without waiting for any database 7337 ** readers or writers to finish, then sync the database file if all frames 7338 ** in the log were checkpointed. ^The [busy-handler callback] 7339 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 7340 ** ^On the other hand, passive mode might leave the checkpoint unfinished 7341 ** if there are concurrent readers or writers. 7342 ** 7343 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 7344 ** ^This mode blocks (it invokes the 7345 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 7346 ** database writer and all readers are reading from the most recent database 7347 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 7348 ** database file. ^This mode blocks new database writers while it is pending, 7349 ** but new database readers are allowed to continue unimpeded. 7350 ** 7351 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7352 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 7353 ** that after checkpointing the log file it blocks (calls the 7354 ** [busy-handler callback]) 7355 ** until all readers are reading from the database file only. ^This ensures 7356 ** that the next writer will restart the log file from the beginning. 7357 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 7358 ** database writer attempts while it is pending, but does not impede readers. 7359 ** 7360 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 7361 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 7362 ** addition that it also truncates the log file to zero bytes just prior 7363 ** to a successful return. 7364 ** </dl> 7365 ** 7366 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 7367 ** the log file or to -1 if the checkpoint could not run because 7368 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 7369 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 7370 ** log file (including any that were already checkpointed before the function 7371 ** was called) or to -1 if the checkpoint could not run due to an error or 7372 ** because the database is not in WAL mode. ^Note that upon successful 7373 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 7374 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 7375 ** 7376 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 7377 ** any other process is running a checkpoint operation at the same time, the 7378 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 7379 ** busy-handler configured, it will not be invoked in this case. 7380 ** 7381 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 7382 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 7383 ** obtained immediately, and a busy-handler is configured, it is invoked and 7384 ** the writer lock retried until either the busy-handler returns 0 or the lock 7385 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 7386 ** database readers as described above. ^If the busy-handler returns 0 before 7387 ** the writer lock is obtained or while waiting for database readers, the 7388 ** checkpoint operation proceeds from that point in the same way as 7389 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7390 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 7391 ** 7392 ** ^If parameter zDb is NULL or points to a zero length string, then the 7393 ** specified operation is attempted on all WAL databases [attached] to 7394 ** [database connection] db. In this case the 7395 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 7396 ** an SQLITE_BUSY error is encountered when processing one or more of the 7397 ** attached WAL databases, the operation is still attempted on any remaining 7398 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 7399 ** error occurs while processing an attached database, processing is abandoned 7400 ** and the error code is returned to the caller immediately. ^If no error 7401 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7402 ** databases, SQLITE_OK is returned. 7403 ** 7404 ** ^If database zDb is the name of an attached database that is not in WAL 7405 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 7406 ** zDb is not NULL (or a zero length string) and is not the name of any 7407 ** attached database, SQLITE_ERROR is returned to the caller. 7408 ** 7409 ** ^Unless it returns SQLITE_MISUSE, 7410 ** the sqlite3_wal_checkpoint_v2() interface 7411 ** sets the error information that is queried by 7412 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 7413 ** 7414 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 7415 ** from SQL. 7416 */ 7417 SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint_v2( 7418 sqlite3 *db, /* Database handle */ 7419 const char *zDb, /* Name of attached database (or NULL) */ 7420 int eMode, /* SQLITE_CHECKPOINT_* value */ 7421 int *pnLog, /* OUT: Size of WAL log in frames */ 7422 int *pnCkpt /* OUT: Total number of frames checkpointed */ 7423 ); 7424 7425 /* 7426 ** CAPI3REF: Checkpoint Mode Values 7427 ** KEYWORDS: {checkpoint mode} 7428 ** 7429 ** These constants define all valid values for the "checkpoint mode" passed 7430 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 7431 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 7432 ** meaning of each of these checkpoint modes. 7433 */ 7434 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 7435 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 7436 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 7437 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 7438 7439 /* 7440 ** CAPI3REF: Virtual Table Interface Configuration 7441 ** 7442 ** This function may be called by either the [xConnect] or [xCreate] method 7443 ** of a [virtual table] implementation to configure 7444 ** various facets of the virtual table interface. 7445 ** 7446 ** If this interface is invoked outside the context of an xConnect or 7447 ** xCreate virtual table method then the behavior is undefined. 7448 ** 7449 ** At present, there is only one option that may be configured using 7450 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7451 ** may be added in the future. 7452 */ 7453 SQLITE_API int SQLITE_CDECL sqlite3_vtab_config(sqlite3*, int op, ...); 7454 7455 /* 7456 ** CAPI3REF: Virtual Table Configuration Options 7457 ** 7458 ** These macros define the various options to the 7459 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 7460 ** can use to customize and optimize their behavior. 7461 ** 7462 ** <dl> 7463 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7464 ** <dd>Calls of the form 7465 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 7466 ** where X is an integer. If X is zero, then the [virtual table] whose 7467 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 7468 ** support constraints. In this configuration (which is the default) if 7469 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 7470 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 7471 ** specified as part of the users SQL statement, regardless of the actual 7472 ** ON CONFLICT mode specified. 7473 ** 7474 ** If X is non-zero, then the virtual table implementation guarantees 7475 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 7476 ** any modifications to internal or persistent data structures have been made. 7477 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 7478 ** is able to roll back a statement or database transaction, and abandon 7479 ** or continue processing the current SQL statement as appropriate. 7480 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 7481 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 7482 ** had been ABORT. 7483 ** 7484 ** Virtual table implementations that are required to handle OR REPLACE 7485 ** must do so within the [xUpdate] method. If a call to the 7486 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 7487 ** CONFLICT policy is REPLACE, the virtual table implementation should 7488 ** silently replace the appropriate rows within the xUpdate callback and 7489 ** return SQLITE_OK. Or, if this is not possible, it may return 7490 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 7491 ** constraint handling. 7492 ** </dl> 7493 */ 7494 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 7495 7496 /* 7497 ** CAPI3REF: Determine The Virtual Table Conflict Policy 7498 ** 7499 ** This function may only be called from within a call to the [xUpdate] method 7500 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 7501 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 7502 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 7503 ** of the SQL statement that triggered the call to the [xUpdate] method of the 7504 ** [virtual table]. 7505 */ 7506 SQLITE_API int SQLITE_STDCALL sqlite3_vtab_on_conflict(sqlite3 *); 7507 7508 /* 7509 ** CAPI3REF: Conflict resolution modes 7510 ** KEYWORDS: {conflict resolution mode} 7511 ** 7512 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 7513 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 7514 ** is for the SQL statement being evaluated. 7515 ** 7516 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 7517 ** return value from the [sqlite3_set_authorizer()] callback and that 7518 ** [SQLITE_ABORT] is also a [result code]. 7519 */ 7520 #define SQLITE_ROLLBACK 1 7521 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 7522 #define SQLITE_FAIL 3 7523 /* #define SQLITE_ABORT 4 // Also an error code */ 7524 #define SQLITE_REPLACE 5 7525 7526 /* 7527 ** CAPI3REF: Prepared Statement Scan Status Opcodes 7528 ** KEYWORDS: {scanstatus options} 7529 ** 7530 ** The following constants can be used for the T parameter to the 7531 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 7532 ** different metric for sqlite3_stmt_scanstatus() to return. 7533 ** 7534 ** When the value returned to V is a string, space to hold that string is 7535 ** managed by the prepared statement S and will be automatically freed when 7536 ** S is finalized. 7537 ** 7538 ** <dl> 7539 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 7540 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 7541 ** set to the total number of times that the X-th loop has run.</dd> 7542 ** 7543 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 7544 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 7545 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 7546 ** 7547 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 7548 ** <dd>^The "double" variable pointed to by the T parameter will be set to the 7549 ** query planner's estimate for the average number of rows output from each 7550 ** iteration of the X-th loop. If the query planner's estimates was accurate, 7551 ** then this value will approximate the quotient NVISIT/NLOOP and the 7552 ** product of this value for all prior loops with the same SELECTID will 7553 ** be the NLOOP value for the current loop. 7554 ** 7555 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 7556 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 7557 ** to a zero-terminated UTF-8 string containing the name of the index or table 7558 ** used for the X-th loop. 7559 ** 7560 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 7561 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 7562 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 7563 ** description for the X-th loop. 7564 ** 7565 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 7566 ** <dd>^The "int" variable pointed to by the T parameter will be set to the 7567 ** "select-id" for the X-th loop. The select-id identifies which query or 7568 ** subquery the loop is part of. The main query has a select-id of zero. 7569 ** The select-id is the same value as is output in the first column 7570 ** of an [EXPLAIN QUERY PLAN] query. 7571 ** </dl> 7572 */ 7573 #define SQLITE_SCANSTAT_NLOOP 0 7574 #define SQLITE_SCANSTAT_NVISIT 1 7575 #define SQLITE_SCANSTAT_EST 2 7576 #define SQLITE_SCANSTAT_NAME 3 7577 #define SQLITE_SCANSTAT_EXPLAIN 4 7578 #define SQLITE_SCANSTAT_SELECTID 5 7579 7580 /* 7581 ** CAPI3REF: Prepared Statement Scan Status 7582 ** 7583 ** This interface returns information about the predicted and measured 7584 ** performance for pStmt. Advanced applications can use this 7585 ** interface to compare the predicted and the measured performance and 7586 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 7587 ** 7588 ** Since this interface is expected to be rarely used, it is only 7589 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 7590 ** compile-time option. 7591 ** 7592 ** The "iScanStatusOp" parameter determines which status information to return. 7593 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 7594 ** of this interface is undefined. 7595 ** ^The requested measurement is written into a variable pointed to by 7596 ** the "pOut" parameter. 7597 ** Parameter "idx" identifies the specific loop to retrieve statistics for. 7598 ** Loops are numbered starting from zero. ^If idx is out of range - less than 7599 ** zero or greater than or equal to the total number of loops used to implement 7600 ** the statement - a non-zero value is returned and the variable that pOut 7601 ** points to is unchanged. 7602 ** 7603 ** ^Statistics might not be available for all loops in all statements. ^In cases 7604 ** where there exist loops with no available statistics, this function behaves 7605 ** as if the loop did not exist - it returns non-zero and leave the variable 7606 ** that pOut points to unchanged. 7607 ** 7608 ** See also: [sqlite3_stmt_scanstatus_reset()] 7609 */ 7610 SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_stmt_scanstatus( 7611 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 7612 int idx, /* Index of loop to report on */ 7613 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 7614 void *pOut /* Result written here */ 7615 ); 7616 7617 /* 7618 ** CAPI3REF: Zero Scan-Status Counters 7619 ** 7620 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 7621 ** 7622 ** This API is only available if the library is built with pre-processor 7623 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 7624 */ 7625 SQLITE_API SQLITE_EXPERIMENTAL void SQLITE_STDCALL sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 7626 7627 7628 /* 7629 ** Undo the hack that converts floating point types to integer for 7630 ** builds on processors without floating point support. 7631 */ 7632 #ifdef SQLITE_OMIT_FLOATING_POINT 7633 # undef double 7634 #endif 7635 7636 #ifdef __cplusplus 7637 } /* End of the 'extern "C"' block */ 7638 #endif 7639 #endif /* _SQLITE3_H_ */ 7640 7641 /* 7642 ** 2010 August 30 7643 ** 7644 ** The author disclaims copyright to this source code. In place of 7645 ** a legal notice, here is a blessing: 7646 ** 7647 ** May you do good and not evil. 7648 ** May you find forgiveness for yourself and forgive others. 7649 ** May you share freely, never taking more than you give. 7650 ** 7651 ************************************************************************* 7652 */ 7653 7654 #ifndef _SQLITE3RTREE_H_ 7655 #define _SQLITE3RTREE_H_ 7656 7657 7658 #ifdef __cplusplus 7659 extern "C" { 7660 #endif 7661 7662 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 7663 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 7664 7665 /* The double-precision datatype used by RTree depends on the 7666 ** SQLITE_RTREE_INT_ONLY compile-time option. 7667 */ 7668 #ifdef SQLITE_RTREE_INT_ONLY 7669 typedef sqlite3_int64 sqlite3_rtree_dbl; 7670 #else 7671 typedef double sqlite3_rtree_dbl; 7672 #endif 7673 7674 /* 7675 ** Register a geometry callback named zGeom that can be used as part of an 7676 ** R-Tree geometry query as follows: 7677 ** 7678 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 7679 */ 7680 SQLITE_API int SQLITE_STDCALL sqlite3_rtree_geometry_callback( 7681 sqlite3 *db, 7682 const char *zGeom, 7683 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 7684 void *pContext 7685 ); 7686 7687 7688 /* 7689 ** A pointer to a structure of the following type is passed as the first 7690 ** argument to callbacks registered using rtree_geometry_callback(). 7691 */ 7692 struct sqlite3_rtree_geometry { 7693 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 7694 int nParam; /* Size of array aParam[] */ 7695 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 7696 void *pUser; /* Callback implementation user data */ 7697 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 7698 }; 7699 7700 /* 7701 ** Register a 2nd-generation geometry callback named zScore that can be 7702 ** used as part of an R-Tree geometry query as follows: 7703 ** 7704 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 7705 */ 7706 SQLITE_API int SQLITE_STDCALL sqlite3_rtree_query_callback( 7707 sqlite3 *db, 7708 const char *zQueryFunc, 7709 int (*xQueryFunc)(sqlite3_rtree_query_info*), 7710 void *pContext, 7711 void (*xDestructor)(void*) 7712 ); 7713 7714 7715 /* 7716 ** A pointer to a structure of the following type is passed as the 7717 ** argument to scored geometry callback registered using 7718 ** sqlite3_rtree_query_callback(). 7719 ** 7720 ** Note that the first 5 fields of this structure are identical to 7721 ** sqlite3_rtree_geometry. This structure is a subclass of 7722 ** sqlite3_rtree_geometry. 7723 */ 7724 struct sqlite3_rtree_query_info { 7725 void *pContext; /* pContext from when function registered */ 7726 int nParam; /* Number of function parameters */ 7727 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 7728 void *pUser; /* callback can use this, if desired */ 7729 void (*xDelUser)(void*); /* function to free pUser */ 7730 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 7731 unsigned int *anQueue; /* Number of pending entries in the queue */ 7732 int nCoord; /* Number of coordinates */ 7733 int iLevel; /* Level of current node or entry */ 7734 int mxLevel; /* The largest iLevel value in the tree */ 7735 sqlite3_int64 iRowid; /* Rowid for current entry */ 7736 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 7737 int eParentWithin; /* Visibility of parent node */ 7738 int eWithin; /* OUT: Visiblity */ 7739 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 7740 }; 7741 7742 /* 7743 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 7744 */ 7745 #define NOT_WITHIN 0 /* Object completely outside of query region */ 7746 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 7747 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 7748 7749 7750 #ifdef __cplusplus 7751 } /* end of the 'extern "C"' block */ 7752 #endif 7753 7754 #endif /* ifndef _SQLITE3RTREE_H_ */ 7755 7756