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 ** Add the ability to override 'extern' 47 */ 48 #ifndef SQLITE_EXTERN 49 # define SQLITE_EXTERN extern 50 #endif 51 52 #ifndef SQLITE_API 53 # define SQLITE_API 54 #endif 55 56 57 /* 58 ** These no-op macros are used in front of interfaces to mark those 59 ** interfaces as either deprecated or experimental. New applications 60 ** should not use deprecated interfaces - they are support for backwards 61 ** compatibility only. Application writers should be aware that 62 ** experimental interfaces are subject to change in point releases. 63 ** 64 ** These macros used to resolve to various kinds of compiler magic that 65 ** would generate warning messages when they were used. But that 66 ** compiler magic ended up generating such a flurry of bug reports 67 ** that we have taken it all out and gone back to using simple 68 ** noop macros. 69 */ 70 #define SQLITE_DEPRECATED 71 #define SQLITE_EXPERIMENTAL 72 73 /* 74 ** Ensure these symbols were not defined by some previous header file. 75 */ 76 #ifdef SQLITE_VERSION 77 # undef SQLITE_VERSION 78 #endif 79 #ifdef SQLITE_VERSION_NUMBER 80 # undef SQLITE_VERSION_NUMBER 81 #endif 82 83 /* 84 ** CAPI3REF: Compile-Time Library Version Numbers 85 ** 86 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 87 ** evaluates to a string literal that is the SQLite version in the 88 ** format "X.Y.Z" where X is the major version number (always 3 for 89 ** SQLite3) and Y is the minor version number and Z is the release number.)^ 90 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 91 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 92 ** numbers used in [SQLITE_VERSION].)^ 93 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 94 ** be larger than the release from which it is derived. Either Y will 95 ** be held constant and Z will be incremented or else Y will be incremented 96 ** and Z will be reset to zero. 97 ** 98 ** Since version 3.6.18, SQLite source code has been stored in the 99 ** <a href="http://www.fossil-scm.org/">Fossil configuration management 100 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 101 ** a string which identifies a particular check-in of SQLite 102 ** within its configuration management system. ^The SQLITE_SOURCE_ID 103 ** string contains the date and time of the check-in (UTC) and an SHA1 104 ** hash of the entire source tree. 105 ** 106 ** See also: [sqlite3_libversion()], 107 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 108 ** [sqlite_version()] and [sqlite_source_id()]. 109 */ 110 #define SQLITE_VERSION "3.7.6.3" 111 #define SQLITE_VERSION_NUMBER 3007006 112 #define SQLITE_SOURCE_ID "2011-05-19 13:26:54 ed1da510a239ea767a01dc332b667119fa3c908e" 113 114 /* 115 ** CAPI3REF: Run-Time Library Version Numbers 116 ** KEYWORDS: sqlite3_version, sqlite3_sourceid 117 ** 118 ** These interfaces provide the same information as the [SQLITE_VERSION], 119 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 120 ** but are associated with the library instead of the header file. ^(Cautious 121 ** programmers might include assert() statements in their application to 122 ** verify that values returned by these interfaces match the macros in 123 ** the header, and thus insure that the application is 124 ** compiled with matching library and header files. 125 ** 126 ** <blockquote><pre> 127 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 128 ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 129 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 130 ** </pre></blockquote>)^ 131 ** 132 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 133 ** macro. ^The sqlite3_libversion() function returns a pointer to the 134 ** to the sqlite3_version[] string constant. The sqlite3_libversion() 135 ** function is provided for use in DLLs since DLL users usually do not have 136 ** direct access to string constants within the DLL. ^The 137 ** sqlite3_libversion_number() function returns an integer equal to 138 ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 139 ** a pointer to a string constant whose value is the same as the 140 ** [SQLITE_SOURCE_ID] C preprocessor macro. 141 ** 142 ** See also: [sqlite_version()] and [sqlite_source_id()]. 143 */ 144 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 145 SQLITE_API const char *sqlite3_libversion(void); 146 SQLITE_API const char *sqlite3_sourceid(void); 147 SQLITE_API int sqlite3_libversion_number(void); 148 149 /* 150 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 151 ** 152 ** ^The sqlite3_compileoption_used() function returns 0 or 1 153 ** indicating whether the specified option was defined at 154 ** compile time. ^The SQLITE_ prefix may be omitted from the 155 ** option name passed to sqlite3_compileoption_used(). 156 ** 157 ** ^The sqlite3_compileoption_get() function allows iterating 158 ** over the list of options that were defined at compile time by 159 ** returning the N-th compile time option string. ^If N is out of range, 160 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 161 ** prefix is omitted from any strings returned by 162 ** sqlite3_compileoption_get(). 163 ** 164 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 165 ** and sqlite3_compileoption_get() may be omitted by specifying the 166 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 167 ** 168 ** See also: SQL functions [sqlite_compileoption_used()] and 169 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 170 */ 171 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 172 SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 173 SQLITE_API const char *sqlite3_compileoption_get(int N); 174 #endif 175 176 /* 177 ** CAPI3REF: Test To See If The Library Is Threadsafe 178 ** 179 ** ^The sqlite3_threadsafe() function returns zero if and only if 180 ** SQLite was compiled mutexing code omitted due to the 181 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 182 ** 183 ** SQLite can be compiled with or without mutexes. When 184 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 185 ** are enabled and SQLite is threadsafe. When the 186 ** [SQLITE_THREADSAFE] macro is 0, 187 ** the mutexes are omitted. Without the mutexes, it is not safe 188 ** to use SQLite concurrently from more than one thread. 189 ** 190 ** Enabling mutexes incurs a measurable performance penalty. 191 ** So if speed is of utmost importance, it makes sense to disable 192 ** the mutexes. But for maximum safety, mutexes should be enabled. 193 ** ^The default behavior is for mutexes to be enabled. 194 ** 195 ** This interface can be used by an application to make sure that the 196 ** version of SQLite that it is linking against was compiled with 197 ** the desired setting of the [SQLITE_THREADSAFE] macro. 198 ** 199 ** This interface only reports on the compile-time mutex setting 200 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 201 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 202 ** can be fully or partially disabled using a call to [sqlite3_config()] 203 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 204 ** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the 205 ** sqlite3_threadsafe() function shows only the compile-time setting of 206 ** thread safety, not any run-time changes to that setting made by 207 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 208 ** is unchanged by calls to sqlite3_config().)^ 209 ** 210 ** See the [threading mode] documentation for additional information. 211 */ 212 SQLITE_API int sqlite3_threadsafe(void); 213 214 /* 215 ** CAPI3REF: Database Connection Handle 216 ** KEYWORDS: {database connection} {database connections} 217 ** 218 ** Each open SQLite database is represented by a pointer to an instance of 219 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 220 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 221 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 222 ** is its destructor. There are many other interfaces (such as 223 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 224 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 225 ** sqlite3 object. 226 */ 227 typedef struct sqlite3 sqlite3; 228 229 /* 230 ** CAPI3REF: 64-Bit Integer Types 231 ** KEYWORDS: sqlite_int64 sqlite_uint64 232 ** 233 ** Because there is no cross-platform way to specify 64-bit integer types 234 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 235 ** 236 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 237 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 238 ** compatibility only. 239 ** 240 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 241 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 242 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 243 ** between 0 and +18446744073709551615 inclusive. 244 */ 245 #ifdef SQLITE_INT64_TYPE 246 typedef SQLITE_INT64_TYPE sqlite_int64; 247 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 248 #elif defined(_MSC_VER) || defined(__BORLANDC__) 249 typedef __int64 sqlite_int64; 250 typedef unsigned __int64 sqlite_uint64; 251 #else 252 typedef long long int sqlite_int64; 253 typedef unsigned long long int sqlite_uint64; 254 #endif 255 typedef sqlite_int64 sqlite3_int64; 256 typedef sqlite_uint64 sqlite3_uint64; 257 258 /* 259 ** If compiling for a processor that lacks floating point support, 260 ** substitute integer for floating-point. 261 */ 262 #ifdef SQLITE_OMIT_FLOATING_POINT 263 # define double sqlite3_int64 264 #endif 265 266 /* 267 ** CAPI3REF: Closing A Database Connection 268 ** 269 ** ^The sqlite3_close() routine is the destructor for the [sqlite3] object. 270 ** ^Calls to sqlite3_close() return SQLITE_OK if the [sqlite3] object is 271 ** successfully destroyed and all associated resources are deallocated. 272 ** 273 ** Applications must [sqlite3_finalize | finalize] all [prepared statements] 274 ** and [sqlite3_blob_close | close] all [BLOB handles] associated with 275 ** the [sqlite3] object prior to attempting to close the object. ^If 276 ** sqlite3_close() is called on a [database connection] that still has 277 ** outstanding [prepared statements] or [BLOB handles], then it returns 278 ** SQLITE_BUSY. 279 ** 280 ** ^If [sqlite3_close()] is invoked while a transaction is open, 281 ** the transaction is automatically rolled back. 282 ** 283 ** The C parameter to [sqlite3_close(C)] must be either a NULL 284 ** pointer or an [sqlite3] object pointer obtained 285 ** from [sqlite3_open()], [sqlite3_open16()], or 286 ** [sqlite3_open_v2()], and not previously closed. 287 ** ^Calling sqlite3_close() with a NULL pointer argument is a 288 ** harmless no-op. 289 */ 290 SQLITE_API int sqlite3_close(sqlite3 *); 291 292 /* 293 ** The type for a callback function. 294 ** This is legacy and deprecated. It is included for historical 295 ** compatibility and is not documented. 296 */ 297 typedef int (*sqlite3_callback)(void*,int,char**, char**); 298 299 /* 300 ** CAPI3REF: One-Step Query Execution Interface 301 ** 302 ** The sqlite3_exec() interface is a convenience wrapper around 303 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 304 ** that allows an application to run multiple statements of SQL 305 ** without having to use a lot of C code. 306 ** 307 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 308 ** semicolon-separate SQL statements passed into its 2nd argument, 309 ** in the context of the [database connection] passed in as its 1st 310 ** argument. ^If the callback function of the 3rd argument to 311 ** sqlite3_exec() is not NULL, then it is invoked for each result row 312 ** coming out of the evaluated SQL statements. ^The 4th argument to 313 ** to sqlite3_exec() is relayed through to the 1st argument of each 314 ** callback invocation. ^If the callback pointer to sqlite3_exec() 315 ** is NULL, then no callback is ever invoked and result rows are 316 ** ignored. 317 ** 318 ** ^If an error occurs while evaluating the SQL statements passed into 319 ** sqlite3_exec(), then execution of the current statement stops and 320 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 321 ** is not NULL then any error message is written into memory obtained 322 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 323 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 324 ** on error message strings returned through the 5th parameter of 325 ** of sqlite3_exec() after the error message string is no longer needed. 326 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 327 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 328 ** NULL before returning. 329 ** 330 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 331 ** routine returns SQLITE_ABORT without invoking the callback again and 332 ** without running any subsequent SQL statements. 333 ** 334 ** ^The 2nd argument to the sqlite3_exec() callback function is the 335 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 336 ** callback is an array of pointers to strings obtained as if from 337 ** [sqlite3_column_text()], one for each column. ^If an element of a 338 ** result row is NULL then the corresponding string pointer for the 339 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 340 ** sqlite3_exec() callback is an array of pointers to strings where each 341 ** entry represents the name of corresponding result column as obtained 342 ** from [sqlite3_column_name()]. 343 ** 344 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 345 ** to an empty string, or a pointer that contains only whitespace and/or 346 ** SQL comments, then no SQL statements are evaluated and the database 347 ** is not changed. 348 ** 349 ** Restrictions: 350 ** 351 ** <ul> 352 ** <li> The application must insure that the 1st parameter to sqlite3_exec() 353 ** is a valid and open [database connection]. 354 ** <li> The application must not close [database connection] specified by 355 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 356 ** <li> The application must not modify the SQL statement text passed into 357 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 358 ** </ul> 359 */ 360 SQLITE_API int sqlite3_exec( 361 sqlite3*, /* An open database */ 362 const char *sql, /* SQL to be evaluated */ 363 int (*callback)(void*,int,char**,char**), /* Callback function */ 364 void *, /* 1st argument to callback */ 365 char **errmsg /* Error msg written here */ 366 ); 367 368 /* 369 ** CAPI3REF: Result Codes 370 ** KEYWORDS: SQLITE_OK {error code} {error codes} 371 ** KEYWORDS: {result code} {result codes} 372 ** 373 ** Many SQLite functions return an integer result code from the set shown 374 ** here in order to indicates success or failure. 375 ** 376 ** New error codes may be added in future versions of SQLite. 377 ** 378 ** See also: [SQLITE_IOERR_READ | extended result codes] 379 */ 380 #define SQLITE_OK 0 /* Successful result */ 381 /* beginning-of-error-codes */ 382 #define SQLITE_ERROR 1 /* SQL error or missing database */ 383 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 384 #define SQLITE_PERM 3 /* Access permission denied */ 385 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 386 #define SQLITE_BUSY 5 /* The database file is locked */ 387 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 388 #define SQLITE_NOMEM 7 /* A malloc() failed */ 389 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 390 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 391 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 392 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 393 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 394 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 395 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 396 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 397 #define SQLITE_EMPTY 16 /* Database is empty */ 398 #define SQLITE_SCHEMA 17 /* The database schema changed */ 399 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 400 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 401 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 402 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 403 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 404 #define SQLITE_AUTH 23 /* Authorization denied */ 405 #define SQLITE_FORMAT 24 /* Auxiliary database format error */ 406 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 407 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 408 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 409 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 410 /* end-of-error-codes */ 411 412 /* 413 ** CAPI3REF: Extended Result Codes 414 ** KEYWORDS: {extended error code} {extended error codes} 415 ** KEYWORDS: {extended result code} {extended result codes} 416 ** 417 ** In its default configuration, SQLite API routines return one of 26 integer 418 ** [SQLITE_OK | result codes]. However, experience has shown that many of 419 ** these result codes are too coarse-grained. They do not provide as 420 ** much information about problems as programmers might like. In an effort to 421 ** address this, newer versions of SQLite (version 3.3.8 and later) include 422 ** support for additional result codes that provide more detailed information 423 ** about errors. The extended result codes are enabled or disabled 424 ** on a per database connection basis using the 425 ** [sqlite3_extended_result_codes()] API. 426 ** 427 ** Some of the available extended result codes are listed here. 428 ** One may expect the number of extended result codes will be expand 429 ** over time. Software that uses extended result codes should expect 430 ** to see new result codes in future releases of SQLite. 431 ** 432 ** The SQLITE_OK result code will never be extended. It will always 433 ** be exactly zero. 434 */ 435 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 436 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 437 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 438 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 439 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 440 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 441 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 442 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 443 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 444 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 445 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 446 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 447 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 448 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 449 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 450 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 451 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 452 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 453 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 454 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 455 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 456 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 457 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 458 459 /* 460 ** CAPI3REF: Flags For File Open Operations 461 ** 462 ** These bit values are intended for use in the 463 ** 3rd parameter to the [sqlite3_open_v2()] interface and 464 ** in the 4th parameter to the xOpen method of the 465 ** [sqlite3_vfs] object. 466 */ 467 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 468 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 469 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 470 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 471 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 472 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 473 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 474 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 475 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 476 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 477 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 478 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 479 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 480 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 481 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 482 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 483 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 484 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 485 486 /* Reserved: 0x00F00000 */ 487 488 /* 489 ** CAPI3REF: Device Characteristics 490 ** 491 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 492 ** object returns an integer which is a vector of the these 493 ** bit values expressing I/O characteristics of the mass storage 494 ** device that holds the file that the [sqlite3_io_methods] 495 ** refers to. 496 ** 497 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 498 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 499 ** mean that writes of blocks that are nnn bytes in size and 500 ** are aligned to an address which is an integer multiple of 501 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 502 ** that when data is appended to a file, the data is appended 503 ** first then the size of the file is extended, never the other 504 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 505 ** information is written to disk in the same order as calls 506 ** to xWrite(). 507 */ 508 #define SQLITE_IOCAP_ATOMIC 0x00000001 509 #define SQLITE_IOCAP_ATOMIC512 0x00000002 510 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 511 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 512 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 513 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 514 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 515 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 516 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 517 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 518 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 519 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 520 521 /* 522 ** CAPI3REF: File Locking Levels 523 ** 524 ** SQLite uses one of these integer values as the second 525 ** argument to calls it makes to the xLock() and xUnlock() methods 526 ** of an [sqlite3_io_methods] object. 527 */ 528 #define SQLITE_LOCK_NONE 0 529 #define SQLITE_LOCK_SHARED 1 530 #define SQLITE_LOCK_RESERVED 2 531 #define SQLITE_LOCK_PENDING 3 532 #define SQLITE_LOCK_EXCLUSIVE 4 533 534 /* 535 ** CAPI3REF: Synchronization Type Flags 536 ** 537 ** When SQLite invokes the xSync() method of an 538 ** [sqlite3_io_methods] object it uses a combination of 539 ** these integer values as the second argument. 540 ** 541 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 542 ** sync operation only needs to flush data to mass storage. Inode 543 ** information need not be flushed. If the lower four bits of the flag 544 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 545 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 546 ** to use Mac OS X style fullsync instead of fsync(). 547 ** 548 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 549 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 550 ** settings. The [synchronous pragma] determines when calls to the 551 ** xSync VFS method occur and applies uniformly across all platforms. 552 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 553 ** energetic or rigorous or forceful the sync operations are and 554 ** only make a difference on Mac OSX for the default SQLite code. 555 ** (Third-party VFS implementations might also make the distinction 556 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 557 ** operating systems natively supported by SQLite, only Mac OSX 558 ** cares about the difference.) 559 */ 560 #define SQLITE_SYNC_NORMAL 0x00002 561 #define SQLITE_SYNC_FULL 0x00003 562 #define SQLITE_SYNC_DATAONLY 0x00010 563 564 /* 565 ** CAPI3REF: OS Interface Open File Handle 566 ** 567 ** An [sqlite3_file] object represents an open file in the 568 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 569 ** implementations will 570 ** want to subclass this object by appending additional fields 571 ** for their own use. The pMethods entry is a pointer to an 572 ** [sqlite3_io_methods] object that defines methods for performing 573 ** I/O operations on the open file. 574 */ 575 typedef struct sqlite3_file sqlite3_file; 576 struct sqlite3_file { 577 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 578 }; 579 580 /* 581 ** CAPI3REF: OS Interface File Virtual Methods Object 582 ** 583 ** Every file opened by the [sqlite3_vfs] xOpen method populates an 584 ** [sqlite3_file] object (or, more commonly, a subclass of the 585 ** [sqlite3_file] object) with a pointer to an instance of this object. 586 ** This object defines the methods used to perform various operations 587 ** against the open file represented by the [sqlite3_file] object. 588 ** 589 ** If the xOpen method sets the sqlite3_file.pMethods element 590 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 591 ** may be invoked even if the xOpen reported that it failed. The 592 ** only way to prevent a call to xClose following a failed xOpen 593 ** is for the xOpen to set the sqlite3_file.pMethods element to NULL. 594 ** 595 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 596 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 597 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 598 ** flag may be ORed in to indicate that only the data of the file 599 ** and not its inode needs to be synced. 600 ** 601 ** The integer values to xLock() and xUnlock() are one of 602 ** <ul> 603 ** <li> [SQLITE_LOCK_NONE], 604 ** <li> [SQLITE_LOCK_SHARED], 605 ** <li> [SQLITE_LOCK_RESERVED], 606 ** <li> [SQLITE_LOCK_PENDING], or 607 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 608 ** </ul> 609 ** xLock() increases the lock. xUnlock() decreases the lock. 610 ** The xCheckReservedLock() method checks whether any database connection, 611 ** either in this process or in some other process, is holding a RESERVED, 612 ** PENDING, or EXCLUSIVE lock on the file. It returns true 613 ** if such a lock exists and false otherwise. 614 ** 615 ** The xFileControl() method is a generic interface that allows custom 616 ** VFS implementations to directly control an open file using the 617 ** [sqlite3_file_control()] interface. The second "op" argument is an 618 ** integer opcode. The third argument is a generic pointer intended to 619 ** point to a structure that may contain arguments or space in which to 620 ** write return values. Potential uses for xFileControl() might be 621 ** functions to enable blocking locks with timeouts, to change the 622 ** locking strategy (for example to use dot-file locks), to inquire 623 ** about the status of a lock, or to break stale locks. The SQLite 624 ** core reserves all opcodes less than 100 for its own use. 625 ** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. 626 ** Applications that define a custom xFileControl method should use opcodes 627 ** greater than 100 to avoid conflicts. VFS implementations should 628 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 629 ** recognize. 630 ** 631 ** The xSectorSize() method returns the sector size of the 632 ** device that underlies the file. The sector size is the 633 ** minimum write that can be performed without disturbing 634 ** other bytes in the file. The xDeviceCharacteristics() 635 ** method returns a bit vector describing behaviors of the 636 ** underlying device: 637 ** 638 ** <ul> 639 ** <li> [SQLITE_IOCAP_ATOMIC] 640 ** <li> [SQLITE_IOCAP_ATOMIC512] 641 ** <li> [SQLITE_IOCAP_ATOMIC1K] 642 ** <li> [SQLITE_IOCAP_ATOMIC2K] 643 ** <li> [SQLITE_IOCAP_ATOMIC4K] 644 ** <li> [SQLITE_IOCAP_ATOMIC8K] 645 ** <li> [SQLITE_IOCAP_ATOMIC16K] 646 ** <li> [SQLITE_IOCAP_ATOMIC32K] 647 ** <li> [SQLITE_IOCAP_ATOMIC64K] 648 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 649 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 650 ** </ul> 651 ** 652 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 653 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 654 ** mean that writes of blocks that are nnn bytes in size and 655 ** are aligned to an address which is an integer multiple of 656 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 657 ** that when data is appended to a file, the data is appended 658 ** first then the size of the file is extended, never the other 659 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 660 ** information is written to disk in the same order as calls 661 ** to xWrite(). 662 ** 663 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 664 ** in the unread portions of the buffer with zeros. A VFS that 665 ** fails to zero-fill short reads might seem to work. However, 666 ** failure to zero-fill short reads will eventually lead to 667 ** database corruption. 668 */ 669 typedef struct sqlite3_io_methods sqlite3_io_methods; 670 struct sqlite3_io_methods { 671 int iVersion; 672 int (*xClose)(sqlite3_file*); 673 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 674 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 675 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 676 int (*xSync)(sqlite3_file*, int flags); 677 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 678 int (*xLock)(sqlite3_file*, int); 679 int (*xUnlock)(sqlite3_file*, int); 680 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 681 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 682 int (*xSectorSize)(sqlite3_file*); 683 int (*xDeviceCharacteristics)(sqlite3_file*); 684 /* Methods above are valid for version 1 */ 685 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 686 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 687 void (*xShmBarrier)(sqlite3_file*); 688 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 689 /* Methods above are valid for version 2 */ 690 /* Additional methods may be added in future releases */ 691 }; 692 693 /* 694 ** CAPI3REF: Standard File Control Opcodes 695 ** 696 ** These integer constants are opcodes for the xFileControl method 697 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 698 ** interface. 699 ** 700 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 701 ** opcode causes the xFileControl method to write the current state of 702 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 703 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 704 ** into an integer that the pArg argument points to. This capability 705 ** is used during testing and only needs to be supported when SQLITE_TEST 706 ** is defined. 707 ** 708 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 709 ** layer a hint of how large the database file will grow to be during the 710 ** current transaction. This hint is not guaranteed to be accurate but it 711 ** is often close. The underlying VFS might choose to preallocate database 712 ** file space based on this hint in order to help writes to the database 713 ** file run faster. 714 ** 715 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 716 ** extends and truncates the database file in chunks of a size specified 717 ** by the user. The fourth argument to [sqlite3_file_control()] should 718 ** point to an integer (type int) containing the new chunk-size to use 719 ** for the nominated database. Allocating database file space in large 720 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 721 ** improve performance on some systems. 722 ** 723 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 724 ** to the [sqlite3_file] object associated with a particular database 725 ** connection. See the [sqlite3_file_control()] documentation for 726 ** additional information. 727 ** 728 ** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by 729 ** SQLite and sent to all VFSes in place of a call to the xSync method 730 ** when the database connection has [PRAGMA synchronous] set to OFF.)^ 731 ** Some specialized VFSes need this signal in order to operate correctly 732 ** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most 733 ** VFSes do not need this signal and should silently ignore this opcode. 734 ** Applications should not call [sqlite3_file_control()] with this 735 ** opcode as doing so may disrupt the operation of the specialized VFSes 736 ** that do require it. 737 */ 738 #define SQLITE_FCNTL_LOCKSTATE 1 739 #define SQLITE_GET_LOCKPROXYFILE 2 740 #define SQLITE_SET_LOCKPROXYFILE 3 741 #define SQLITE_LAST_ERRNO 4 742 #define SQLITE_FCNTL_SIZE_HINT 5 743 #define SQLITE_FCNTL_CHUNK_SIZE 6 744 #define SQLITE_FCNTL_FILE_POINTER 7 745 #define SQLITE_FCNTL_SYNC_OMITTED 8 746 747 748 /* 749 ** CAPI3REF: Mutex Handle 750 ** 751 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 752 ** abstract type for a mutex object. The SQLite core never looks 753 ** at the internal representation of an [sqlite3_mutex]. It only 754 ** deals with pointers to the [sqlite3_mutex] object. 755 ** 756 ** Mutexes are created using [sqlite3_mutex_alloc()]. 757 */ 758 typedef struct sqlite3_mutex sqlite3_mutex; 759 760 /* 761 ** CAPI3REF: OS Interface Object 762 ** 763 ** An instance of the sqlite3_vfs object defines the interface between 764 ** the SQLite core and the underlying operating system. The "vfs" 765 ** in the name of the object stands for "virtual file system". 766 ** 767 ** The value of the iVersion field is initially 1 but may be larger in 768 ** future versions of SQLite. Additional fields may be appended to this 769 ** object when the iVersion value is increased. Note that the structure 770 ** of the sqlite3_vfs object changes in the transaction between 771 ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 772 ** modified. 773 ** 774 ** The szOsFile field is the size of the subclassed [sqlite3_file] 775 ** structure used by this VFS. mxPathname is the maximum length of 776 ** a pathname in this VFS. 777 ** 778 ** Registered sqlite3_vfs objects are kept on a linked list formed by 779 ** the pNext pointer. The [sqlite3_vfs_register()] 780 ** and [sqlite3_vfs_unregister()] interfaces manage this list 781 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 782 ** searches the list. Neither the application code nor the VFS 783 ** implementation should use the pNext pointer. 784 ** 785 ** The pNext field is the only field in the sqlite3_vfs 786 ** structure that SQLite will ever modify. SQLite will only access 787 ** or modify this field while holding a particular static mutex. 788 ** The application should never modify anything within the sqlite3_vfs 789 ** object once the object has been registered. 790 ** 791 ** The zName field holds the name of the VFS module. The name must 792 ** be unique across all VFS modules. 793 ** 794 ** ^SQLite guarantees that the zFilename parameter to xOpen 795 ** is either a NULL pointer or string obtained 796 ** from xFullPathname() with an optional suffix added. 797 ** ^If a suffix is added to the zFilename parameter, it will 798 ** consist of a single "-" character followed by no more than 799 ** 10 alphanumeric and/or "-" characters. 800 ** ^SQLite further guarantees that 801 ** the string will be valid and unchanged until xClose() is 802 ** called. Because of the previous sentence, 803 ** the [sqlite3_file] can safely store a pointer to the 804 ** filename if it needs to remember the filename for some reason. 805 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 806 ** must invent its own temporary name for the file. ^Whenever the 807 ** xFilename parameter is NULL it will also be the case that the 808 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 809 ** 810 ** The flags argument to xOpen() includes all bits set in 811 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 812 ** or [sqlite3_open16()] is used, then flags includes at least 813 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 814 ** If xOpen() opens a file read-only then it sets *pOutFlags to 815 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 816 ** 817 ** ^(SQLite will also add one of the following flags to the xOpen() 818 ** call, depending on the object being opened: 819 ** 820 ** <ul> 821 ** <li> [SQLITE_OPEN_MAIN_DB] 822 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 823 ** <li> [SQLITE_OPEN_TEMP_DB] 824 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 825 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 826 ** <li> [SQLITE_OPEN_SUBJOURNAL] 827 ** <li> [SQLITE_OPEN_MASTER_JOURNAL] 828 ** <li> [SQLITE_OPEN_WAL] 829 ** </ul>)^ 830 ** 831 ** The file I/O implementation can use the object type flags to 832 ** change the way it deals with files. For example, an application 833 ** that does not care about crash recovery or rollback might make 834 ** the open of a journal file a no-op. Writes to this journal would 835 ** also be no-ops, and any attempt to read the journal would return 836 ** SQLITE_IOERR. Or the implementation might recognize that a database 837 ** file will be doing page-aligned sector reads and writes in a random 838 ** order and set up its I/O subsystem accordingly. 839 ** 840 ** SQLite might also add one of the following flags to the xOpen method: 841 ** 842 ** <ul> 843 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 844 ** <li> [SQLITE_OPEN_EXCLUSIVE] 845 ** </ul> 846 ** 847 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 848 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 849 ** will be set for TEMP databases and their journals, transient 850 ** databases, and subjournals. 851 ** 852 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 853 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 854 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 855 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 856 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 857 ** be created, and that it is an error if it already exists. 858 ** It is <i>not</i> used to indicate the file should be opened 859 ** for exclusive access. 860 ** 861 ** ^At least szOsFile bytes of memory are allocated by SQLite 862 ** to hold the [sqlite3_file] structure passed as the third 863 ** argument to xOpen. The xOpen method does not have to 864 ** allocate the structure; it should just fill it in. Note that 865 ** the xOpen method must set the sqlite3_file.pMethods to either 866 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 867 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 868 ** element will be valid after xOpen returns regardless of the success 869 ** or failure of the xOpen call. 870 ** 871 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 872 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 873 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 874 ** to test whether a file is at least readable. The file can be a 875 ** directory. 876 ** 877 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 878 ** output buffer xFullPathname. The exact size of the output buffer 879 ** is also passed as a parameter to both methods. If the output buffer 880 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 881 ** handled as a fatal error by SQLite, vfs implementations should endeavor 882 ** to prevent this by setting mxPathname to a sufficiently large value. 883 ** 884 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 885 ** interfaces are not strictly a part of the filesystem, but they are 886 ** included in the VFS structure for completeness. 887 ** The xRandomness() function attempts to return nBytes bytes 888 ** of good-quality randomness into zOut. The return value is 889 ** the actual number of bytes of randomness obtained. 890 ** The xSleep() method causes the calling thread to sleep for at 891 ** least the number of microseconds given. ^The xCurrentTime() 892 ** method returns a Julian Day Number for the current date and time as 893 ** a floating point value. 894 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 895 ** Day Number multipled by 86400000 (the number of milliseconds in 896 ** a 24-hour day). 897 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 898 ** date and time if that method is available (if iVersion is 2 or 899 ** greater and the function pointer is not NULL) and will fall back 900 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 901 ** 902 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 903 ** are not used by the SQLite core. These optional interfaces are provided 904 ** by some VFSes to facilitate testing of the VFS code. By overriding 905 ** system calls with functions under its control, a test program can 906 ** simulate faults and error conditions that would otherwise be difficult 907 ** or impossible to induce. The set of system calls that can be overridden 908 ** varies from one VFS to another, and from one version of the same VFS to the 909 ** next. Applications that use these interfaces must be prepared for any 910 ** or all of these interfaces to be NULL or for their behavior to change 911 ** from one release to the next. Applications must not attempt to access 912 ** any of these methods if the iVersion of the VFS is less than 3. 913 */ 914 typedef struct sqlite3_vfs sqlite3_vfs; 915 typedef void (*sqlite3_syscall_ptr)(void); 916 struct sqlite3_vfs { 917 int iVersion; /* Structure version number (currently 3) */ 918 int szOsFile; /* Size of subclassed sqlite3_file */ 919 int mxPathname; /* Maximum file pathname length */ 920 sqlite3_vfs *pNext; /* Next registered VFS */ 921 const char *zName; /* Name of this virtual file system */ 922 void *pAppData; /* Pointer to application-specific data */ 923 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 924 int flags, int *pOutFlags); 925 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 926 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 927 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 928 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 929 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 930 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 931 void (*xDlClose)(sqlite3_vfs*, void*); 932 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 933 int (*xSleep)(sqlite3_vfs*, int microseconds); 934 int (*xCurrentTime)(sqlite3_vfs*, double*); 935 int (*xGetLastError)(sqlite3_vfs*, int, char *); 936 /* 937 ** The methods above are in version 1 of the sqlite_vfs object 938 ** definition. Those that follow are added in version 2 or later 939 */ 940 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 941 /* 942 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 943 ** Those below are for version 3 and greater. 944 */ 945 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 946 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 947 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 948 /* 949 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 950 ** New fields may be appended in figure versions. The iVersion 951 ** value will increment whenever this happens. 952 */ 953 }; 954 955 /* 956 ** CAPI3REF: Flags for the xAccess VFS method 957 ** 958 ** These integer constants can be used as the third parameter to 959 ** the xAccess method of an [sqlite3_vfs] object. They determine 960 ** what kind of permissions the xAccess method is looking for. 961 ** With SQLITE_ACCESS_EXISTS, the xAccess method 962 ** simply checks whether the file exists. 963 ** With SQLITE_ACCESS_READWRITE, the xAccess method 964 ** checks whether the named directory is both readable and writable 965 ** (in other words, if files can be added, removed, and renamed within 966 ** the directory). 967 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 968 ** [temp_store_directory pragma], though this could change in a future 969 ** release of SQLite. 970 ** With SQLITE_ACCESS_READ, the xAccess method 971 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 972 ** currently unused, though it might be used in a future release of 973 ** SQLite. 974 */ 975 #define SQLITE_ACCESS_EXISTS 0 976 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 977 #define SQLITE_ACCESS_READ 2 /* Unused */ 978 979 /* 980 ** CAPI3REF: Flags for the xShmLock VFS method 981 ** 982 ** These integer constants define the various locking operations 983 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 984 ** following are the only legal combinations of flags to the 985 ** xShmLock method: 986 ** 987 ** <ul> 988 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 989 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 990 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 991 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 992 ** </ul> 993 ** 994 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 995 ** was given no the corresponding lock. 996 ** 997 ** The xShmLock method can transition between unlocked and SHARED or 998 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 999 ** and EXCLUSIVE. 1000 */ 1001 #define SQLITE_SHM_UNLOCK 1 1002 #define SQLITE_SHM_LOCK 2 1003 #define SQLITE_SHM_SHARED 4 1004 #define SQLITE_SHM_EXCLUSIVE 8 1005 1006 /* 1007 ** CAPI3REF: Maximum xShmLock index 1008 ** 1009 ** The xShmLock method on [sqlite3_io_methods] may use values 1010 ** between 0 and this upper bound as its "offset" argument. 1011 ** The SQLite core will never attempt to acquire or release a 1012 ** lock outside of this range 1013 */ 1014 #define SQLITE_SHM_NLOCK 8 1015 1016 1017 /* 1018 ** CAPI3REF: Initialize The SQLite Library 1019 ** 1020 ** ^The sqlite3_initialize() routine initializes the 1021 ** SQLite library. ^The sqlite3_shutdown() routine 1022 ** deallocates any resources that were allocated by sqlite3_initialize(). 1023 ** These routines are designed to aid in process initialization and 1024 ** shutdown on embedded systems. Workstation applications using 1025 ** SQLite normally do not need to invoke either of these routines. 1026 ** 1027 ** A call to sqlite3_initialize() is an "effective" call if it is 1028 ** the first time sqlite3_initialize() is invoked during the lifetime of 1029 ** the process, or if it is the first time sqlite3_initialize() is invoked 1030 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1031 ** of sqlite3_initialize() does any initialization. All other calls 1032 ** are harmless no-ops.)^ 1033 ** 1034 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1035 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1036 ** an effective call to sqlite3_shutdown() does any deinitialization. 1037 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1038 ** 1039 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1040 ** is not. The sqlite3_shutdown() interface must only be called from a 1041 ** single thread. All open [database connections] must be closed and all 1042 ** other SQLite resources must be deallocated prior to invoking 1043 ** sqlite3_shutdown(). 1044 ** 1045 ** Among other things, ^sqlite3_initialize() will invoke 1046 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1047 ** will invoke sqlite3_os_end(). 1048 ** 1049 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1050 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1051 ** the library (perhaps it is unable to allocate a needed resource such 1052 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1053 ** 1054 ** ^The sqlite3_initialize() routine is called internally by many other 1055 ** SQLite interfaces so that an application usually does not need to 1056 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1057 ** calls sqlite3_initialize() so the SQLite library will be automatically 1058 ** initialized when [sqlite3_open()] is called if it has not be initialized 1059 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1060 ** compile-time option, then the automatic calls to sqlite3_initialize() 1061 ** are omitted and the application must call sqlite3_initialize() directly 1062 ** prior to using any other SQLite interface. For maximum portability, 1063 ** it is recommended that applications always invoke sqlite3_initialize() 1064 ** directly prior to using any other SQLite interface. Future releases 1065 ** of SQLite may require this. In other words, the behavior exhibited 1066 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1067 ** default behavior in some future release of SQLite. 1068 ** 1069 ** The sqlite3_os_init() routine does operating-system specific 1070 ** initialization of the SQLite library. The sqlite3_os_end() 1071 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1072 ** performed by these routines include allocation or deallocation 1073 ** of static resources, initialization of global variables, 1074 ** setting up a default [sqlite3_vfs] module, or setting up 1075 ** a default configuration using [sqlite3_config()]. 1076 ** 1077 ** The application should never invoke either sqlite3_os_init() 1078 ** or sqlite3_os_end() directly. The application should only invoke 1079 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1080 ** interface is called automatically by sqlite3_initialize() and 1081 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1082 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1083 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1084 ** When [custom builds | built for other platforms] 1085 ** (using the [SQLITE_OS_OTHER=1] compile-time 1086 ** option) the application must supply a suitable implementation for 1087 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1088 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1089 ** must return [SQLITE_OK] on success and some other [error code] upon 1090 ** failure. 1091 */ 1092 SQLITE_API int sqlite3_initialize(void); 1093 SQLITE_API int sqlite3_shutdown(void); 1094 SQLITE_API int sqlite3_os_init(void); 1095 SQLITE_API int sqlite3_os_end(void); 1096 1097 /* 1098 ** CAPI3REF: Configuring The SQLite Library 1099 ** 1100 ** The sqlite3_config() interface is used to make global configuration 1101 ** changes to SQLite in order to tune SQLite to the specific needs of 1102 ** the application. The default configuration is recommended for most 1103 ** applications and so this routine is usually not necessary. It is 1104 ** provided to support rare applications with unusual needs. 1105 ** 1106 ** The sqlite3_config() interface is not threadsafe. The application 1107 ** must insure that no other SQLite interfaces are invoked by other 1108 ** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 1109 ** may only be invoked prior to library initialization using 1110 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1111 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1112 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1113 ** Note, however, that ^sqlite3_config() can be called as part of the 1114 ** implementation of an application-defined [sqlite3_os_init()]. 1115 ** 1116 ** The first argument to sqlite3_config() is an integer 1117 ** [SQLITE_CONFIG_SINGLETHREAD | configuration option] that determines 1118 ** what property of SQLite is to be configured. Subsequent arguments 1119 ** vary depending on the [SQLITE_CONFIG_SINGLETHREAD | configuration option] 1120 ** in the first argument. 1121 ** 1122 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1123 ** ^If the option is unknown or SQLite is unable to set the option 1124 ** then this routine returns a non-zero [error code]. 1125 */ 1126 SQLITE_API int sqlite3_config(int, ...); 1127 1128 /* 1129 ** CAPI3REF: Configure database connections 1130 ** 1131 ** The sqlite3_db_config() interface is used to make configuration 1132 ** changes to a [database connection]. The interface is similar to 1133 ** [sqlite3_config()] except that the changes apply to a single 1134 ** [database connection] (specified in the first argument). 1135 ** 1136 ** The second argument to sqlite3_db_config(D,V,...) is the 1137 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1138 ** that indicates what aspect of the [database connection] is being configured. 1139 ** Subsequent arguments vary depending on the configuration verb. 1140 ** 1141 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1142 ** the call is considered successful. 1143 */ 1144 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1145 1146 /* 1147 ** CAPI3REF: Memory Allocation Routines 1148 ** 1149 ** An instance of this object defines the interface between SQLite 1150 ** and low-level memory allocation routines. 1151 ** 1152 ** This object is used in only one place in the SQLite interface. 1153 ** A pointer to an instance of this object is the argument to 1154 ** [sqlite3_config()] when the configuration option is 1155 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1156 ** By creating an instance of this object 1157 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1158 ** during configuration, an application can specify an alternative 1159 ** memory allocation subsystem for SQLite to use for all of its 1160 ** dynamic memory needs. 1161 ** 1162 ** Note that SQLite comes with several [built-in memory allocators] 1163 ** that are perfectly adequate for the overwhelming majority of applications 1164 ** and that this object is only useful to a tiny minority of applications 1165 ** with specialized memory allocation requirements. This object is 1166 ** also used during testing of SQLite in order to specify an alternative 1167 ** memory allocator that simulates memory out-of-memory conditions in 1168 ** order to verify that SQLite recovers gracefully from such 1169 ** conditions. 1170 ** 1171 ** The xMalloc and xFree methods must work like the 1172 ** malloc() and free() functions from the standard C library. 1173 ** The xRealloc method must work like realloc() from the standard C library 1174 ** with the exception that if the second argument to xRealloc is zero, 1175 ** xRealloc must be a no-op - it must not perform any allocation or 1176 ** deallocation. ^SQLite guarantees that the second argument to 1177 ** xRealloc is always a value returned by a prior call to xRoundup. 1178 ** And so in cases where xRoundup always returns a positive number, 1179 ** xRealloc can perform exactly as the standard library realloc() and 1180 ** still be in compliance with this specification. 1181 ** 1182 ** xSize should return the allocated size of a memory allocation 1183 ** previously obtained from xMalloc or xRealloc. The allocated size 1184 ** is always at least as big as the requested size but may be larger. 1185 ** 1186 ** The xRoundup method returns what would be the allocated size of 1187 ** a memory allocation given a particular requested size. Most memory 1188 ** allocators round up memory allocations at least to the next multiple 1189 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1190 ** Every memory allocation request coming in through [sqlite3_malloc()] 1191 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1192 ** that causes the corresponding memory allocation to fail. 1193 ** 1194 ** The xInit method initializes the memory allocator. (For example, 1195 ** it might allocate any require mutexes or initialize internal data 1196 ** structures. The xShutdown method is invoked (indirectly) by 1197 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1198 ** by xInit. The pAppData pointer is used as the only parameter to 1199 ** xInit and xShutdown. 1200 ** 1201 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1202 ** the xInit method, so the xInit method need not be threadsafe. The 1203 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1204 ** not need to be threadsafe either. For all other methods, SQLite 1205 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1206 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1207 ** it is by default) and so the methods are automatically serialized. 1208 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1209 ** methods must be threadsafe or else make their own arrangements for 1210 ** serialization. 1211 ** 1212 ** SQLite will never invoke xInit() more than once without an intervening 1213 ** call to xShutdown(). 1214 */ 1215 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1216 struct sqlite3_mem_methods { 1217 void *(*xMalloc)(int); /* Memory allocation function */ 1218 void (*xFree)(void*); /* Free a prior allocation */ 1219 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1220 int (*xSize)(void*); /* Return the size of an allocation */ 1221 int (*xRoundup)(int); /* Round up request size to allocation size */ 1222 int (*xInit)(void*); /* Initialize the memory allocator */ 1223 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1224 void *pAppData; /* Argument to xInit() and xShutdown() */ 1225 }; 1226 1227 /* 1228 ** CAPI3REF: Configuration Options 1229 ** 1230 ** These constants are the available integer configuration options that 1231 ** can be passed as the first argument to the [sqlite3_config()] interface. 1232 ** 1233 ** New configuration options may be added in future releases of SQLite. 1234 ** Existing configuration options might be discontinued. Applications 1235 ** should check the return code from [sqlite3_config()] to make sure that 1236 ** the call worked. The [sqlite3_config()] interface will return a 1237 ** non-zero [error code] if a discontinued or unsupported configuration option 1238 ** is invoked. 1239 ** 1240 ** <dl> 1241 ** <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1242 ** <dd>There are no arguments to this option. ^This option sets the 1243 ** [threading mode] to Single-thread. In other words, it disables 1244 ** all mutexing and puts SQLite into a mode where it can only be used 1245 ** by a single thread. ^If SQLite is compiled with 1246 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1247 ** it is not possible to change the [threading mode] from its default 1248 ** value of Single-thread and so [sqlite3_config()] will return 1249 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1250 ** configuration option.</dd> 1251 ** 1252 ** <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1253 ** <dd>There are no arguments to this option. ^This option sets the 1254 ** [threading mode] to Multi-thread. In other words, it disables 1255 ** mutexing on [database connection] and [prepared statement] objects. 1256 ** The application is responsible for serializing access to 1257 ** [database connections] and [prepared statements]. But other mutexes 1258 ** are enabled so that SQLite will be safe to use in a multi-threaded 1259 ** environment as long as no two threads attempt to use the same 1260 ** [database connection] at the same time. ^If SQLite is compiled with 1261 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1262 ** it is not possible to set the Multi-thread [threading mode] and 1263 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1264 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1265 ** 1266 ** <dt>SQLITE_CONFIG_SERIALIZED</dt> 1267 ** <dd>There are no arguments to this option. ^This option sets the 1268 ** [threading mode] to Serialized. In other words, this option enables 1269 ** all mutexes including the recursive 1270 ** mutexes on [database connection] and [prepared statement] objects. 1271 ** In this mode (which is the default when SQLite is compiled with 1272 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1273 ** to [database connections] and [prepared statements] so that the 1274 ** application is free to use the same [database connection] or the 1275 ** same [prepared statement] in different threads at the same time. 1276 ** ^If SQLite is compiled with 1277 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1278 ** it is not possible to set the Serialized [threading mode] and 1279 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1280 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1281 ** 1282 ** <dt>SQLITE_CONFIG_MALLOC</dt> 1283 ** <dd> ^(This option takes a single argument which is a pointer to an 1284 ** instance of the [sqlite3_mem_methods] structure. The argument specifies 1285 ** alternative low-level memory allocation routines to be used in place of 1286 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1287 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1288 ** before the [sqlite3_config()] call returns.</dd> 1289 ** 1290 ** <dt>SQLITE_CONFIG_GETMALLOC</dt> 1291 ** <dd> ^(This option takes a single argument which is a pointer to an 1292 ** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] 1293 ** structure is filled with the currently defined memory allocation routines.)^ 1294 ** This option can be used to overload the default memory allocation 1295 ** routines with a wrapper that simulations memory allocation failure or 1296 ** tracks memory usage, for example. </dd> 1297 ** 1298 ** <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1299 ** <dd> ^This option takes single argument of type int, interpreted as a 1300 ** boolean, which enables or disables the collection of memory allocation 1301 ** statistics. ^(When memory allocation statistics are disabled, the 1302 ** following SQLite interfaces become non-operational: 1303 ** <ul> 1304 ** <li> [sqlite3_memory_used()] 1305 ** <li> [sqlite3_memory_highwater()] 1306 ** <li> [sqlite3_soft_heap_limit64()] 1307 ** <li> [sqlite3_status()] 1308 ** </ul>)^ 1309 ** ^Memory allocation statistics are enabled by default unless SQLite is 1310 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1311 ** allocation statistics are disabled by default. 1312 ** </dd> 1313 ** 1314 ** <dt>SQLITE_CONFIG_SCRATCH</dt> 1315 ** <dd> ^This option specifies a static memory buffer that SQLite can use for 1316 ** scratch memory. There are three arguments: A pointer an 8-byte 1317 ** aligned memory buffer from which the scratch allocations will be 1318 ** drawn, the size of each scratch allocation (sz), 1319 ** and the maximum number of scratch allocations (N). The sz 1320 ** argument must be a multiple of 16. 1321 ** The first argument must be a pointer to an 8-byte aligned buffer 1322 ** of at least sz*N bytes of memory. 1323 ** ^SQLite will use no more than two scratch buffers per thread. So 1324 ** N should be set to twice the expected maximum number of threads. 1325 ** ^SQLite will never require a scratch buffer that is more than 6 1326 ** times the database page size. ^If SQLite needs needs additional 1327 ** scratch memory beyond what is provided by this configuration option, then 1328 ** [sqlite3_malloc()] will be used to obtain the memory needed.</dd> 1329 ** 1330 ** <dt>SQLITE_CONFIG_PAGECACHE</dt> 1331 ** <dd> ^This option specifies a static memory buffer that SQLite can use for 1332 ** the database page cache with the default page cache implemenation. 1333 ** This configuration should not be used if an application-define page 1334 ** cache implementation is loaded using the SQLITE_CONFIG_PCACHE option. 1335 ** There are three arguments to this option: A pointer to 8-byte aligned 1336 ** memory, the size of each page buffer (sz), and the number of pages (N). 1337 ** The sz argument should be the size of the largest database page 1338 ** (a power of two between 512 and 32768) plus a little extra for each 1339 ** page header. ^The page header size is 20 to 40 bytes depending on 1340 ** the host architecture. ^It is harmless, apart from the wasted memory, 1341 ** to make sz a little too large. The first 1342 ** argument should point to an allocation of at least sz*N bytes of memory. 1343 ** ^SQLite will use the memory provided by the first argument to satisfy its 1344 ** memory needs for the first N pages that it adds to cache. ^If additional 1345 ** page cache memory is needed beyond what is provided by this option, then 1346 ** SQLite goes to [sqlite3_malloc()] for the additional storage space. 1347 ** The pointer in the first argument must 1348 ** be aligned to an 8-byte boundary or subsequent behavior of SQLite 1349 ** will be undefined.</dd> 1350 ** 1351 ** <dt>SQLITE_CONFIG_HEAP</dt> 1352 ** <dd> ^This option specifies a static memory buffer that SQLite will use 1353 ** for all of its dynamic memory allocation needs beyond those provided 1354 ** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. 1355 ** There are three arguments: An 8-byte aligned pointer to the memory, 1356 ** the number of bytes in the memory buffer, and the minimum allocation size. 1357 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1358 ** to using its default memory allocator (the system malloc() implementation), 1359 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1360 ** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or 1361 ** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory 1362 ** allocator is engaged to handle all of SQLites memory allocation needs. 1363 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1364 ** boundary or subsequent behavior of SQLite will be undefined. 1365 ** The minimum allocation size is capped at 2^12. Reasonable values 1366 ** for the minimum allocation size are 2^5 through 2^8.</dd> 1367 ** 1368 ** <dt>SQLITE_CONFIG_MUTEX</dt> 1369 ** <dd> ^(This option takes a single argument which is a pointer to an 1370 ** instance of the [sqlite3_mutex_methods] structure. The argument specifies 1371 ** alternative low-level mutex routines to be used in place 1372 ** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the 1373 ** content of the [sqlite3_mutex_methods] structure before the call to 1374 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1375 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1376 ** the entire mutexing subsystem is omitted from the build and hence calls to 1377 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1378 ** return [SQLITE_ERROR].</dd> 1379 ** 1380 ** <dt>SQLITE_CONFIG_GETMUTEX</dt> 1381 ** <dd> ^(This option takes a single argument which is a pointer to an 1382 ** instance of the [sqlite3_mutex_methods] structure. The 1383 ** [sqlite3_mutex_methods] 1384 ** structure is filled with the currently defined mutex routines.)^ 1385 ** This option can be used to overload the default mutex allocation 1386 ** routines with a wrapper used to track mutex usage for performance 1387 ** profiling or testing, for example. ^If SQLite is compiled with 1388 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1389 ** the entire mutexing subsystem is omitted from the build and hence calls to 1390 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1391 ** return [SQLITE_ERROR].</dd> 1392 ** 1393 ** <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1394 ** <dd> ^(This option takes two arguments that determine the default 1395 ** memory allocation for the lookaside memory allocator on each 1396 ** [database connection]. The first argument is the 1397 ** size of each lookaside buffer slot and the second is the number of 1398 ** slots allocated to each database connection.)^ ^(This option sets the 1399 ** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1400 ** verb to [sqlite3_db_config()] can be used to change the lookaside 1401 ** configuration on individual connections.)^ </dd> 1402 ** 1403 ** <dt>SQLITE_CONFIG_PCACHE</dt> 1404 ** <dd> ^(This option takes a single argument which is a pointer to 1405 ** an [sqlite3_pcache_methods] object. This object specifies the interface 1406 ** to a custom page cache implementation.)^ ^SQLite makes a copy of the 1407 ** object and uses it for page cache memory allocations.</dd> 1408 ** 1409 ** <dt>SQLITE_CONFIG_GETPCACHE</dt> 1410 ** <dd> ^(This option takes a single argument which is a pointer to an 1411 ** [sqlite3_pcache_methods] object. SQLite copies of the current 1412 ** page cache implementation into that object.)^ </dd> 1413 ** 1414 ** <dt>SQLITE_CONFIG_LOG</dt> 1415 ** <dd> ^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1416 ** function with a call signature of void(*)(void*,int,const char*), 1417 ** and a pointer to void. ^If the function pointer is not NULL, it is 1418 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1419 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1420 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1421 ** passed through as the first parameter to the application-defined logger 1422 ** function whenever that function is invoked. ^The second parameter to 1423 ** the logger function is a copy of the first parameter to the corresponding 1424 ** [sqlite3_log()] call and is intended to be a [result code] or an 1425 ** [extended result code]. ^The third parameter passed to the logger is 1426 ** log message after formatting via [sqlite3_snprintf()]. 1427 ** The SQLite logging interface is not reentrant; the logger function 1428 ** supplied by the application must not invoke any SQLite interface. 1429 ** In a multi-threaded application, the application-defined logger 1430 ** function must be threadsafe. </dd> 1431 ** 1432 ** </dl> 1433 */ 1434 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1435 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1436 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1437 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1438 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1439 #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1440 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1441 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1442 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1443 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1444 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1445 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1446 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1447 #define SQLITE_CONFIG_PCACHE 14 /* sqlite3_pcache_methods* */ 1448 #define SQLITE_CONFIG_GETPCACHE 15 /* sqlite3_pcache_methods* */ 1449 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1450 1451 /* 1452 ** CAPI3REF: Database Connection Configuration Options 1453 ** 1454 ** These constants are the available integer configuration options that 1455 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 1456 ** 1457 ** New configuration options may be added in future releases of SQLite. 1458 ** Existing configuration options might be discontinued. Applications 1459 ** should check the return code from [sqlite3_db_config()] to make sure that 1460 ** the call worked. ^The [sqlite3_db_config()] interface will return a 1461 ** non-zero [error code] if a discontinued or unsupported configuration option 1462 ** is invoked. 1463 ** 1464 ** <dl> 1465 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1466 ** <dd> ^This option takes three additional arguments that determine the 1467 ** [lookaside memory allocator] configuration for the [database connection]. 1468 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1469 ** pointer to a memory buffer to use for lookaside memory. 1470 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1471 ** may be NULL in which case SQLite will allocate the 1472 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1473 ** size of each lookaside buffer slot. ^The third argument is the number of 1474 ** slots. The size of the buffer in the first argument must be greater than 1475 ** or equal to the product of the second and third arguments. The buffer 1476 ** must be aligned to an 8-byte boundary. ^If the second argument to 1477 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1478 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1479 ** configuration for a database connection can only be changed when that 1480 ** connection is not currently using lookaside memory, or in other words 1481 ** when the "current value" returned by 1482 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1483 ** Any attempt to change the lookaside memory configuration when lookaside 1484 ** memory is in use leaves the configuration unchanged and returns 1485 ** [SQLITE_BUSY].)^</dd> 1486 ** 1487 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1488 ** <dd> ^This option is used to enable or disable the enforcement of 1489 ** [foreign key constraints]. There should be two additional arguments. 1490 ** The first argument is an integer which is 0 to disable FK enforcement, 1491 ** positive to enable FK enforcement or negative to leave FK enforcement 1492 ** unchanged. The second parameter is a pointer to an integer into which 1493 ** is written 0 or 1 to indicate whether FK enforcement is off or on 1494 ** following this call. The second parameter may be a NULL pointer, in 1495 ** which case the FK enforcement setting is not reported back. </dd> 1496 ** 1497 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1498 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1499 ** There should be two additional arguments. 1500 ** The first argument is an integer which is 0 to disable triggers, 1501 ** positive to enable triggers or negative to leave the setting unchanged. 1502 ** The second parameter is a pointer to an integer into which 1503 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 1504 ** following this call. The second parameter may be a NULL pointer, in 1505 ** which case the trigger setting is not reported back. </dd> 1506 ** 1507 ** </dl> 1508 */ 1509 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1510 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1511 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1512 1513 1514 /* 1515 ** CAPI3REF: Enable Or Disable Extended Result Codes 1516 ** 1517 ** ^The sqlite3_extended_result_codes() routine enables or disables the 1518 ** [extended result codes] feature of SQLite. ^The extended result 1519 ** codes are disabled by default for historical compatibility. 1520 */ 1521 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 1522 1523 /* 1524 ** CAPI3REF: Last Insert Rowid 1525 ** 1526 ** ^Each entry in an SQLite table has a unique 64-bit signed 1527 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1528 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1529 ** names are not also used by explicitly declared columns. ^If 1530 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 1531 ** is another alias for the rowid. 1532 ** 1533 ** ^This routine returns the [rowid] of the most recent 1534 ** successful [INSERT] into the database from the [database connection] 1535 ** in the first argument. ^If no successful [INSERT]s 1536 ** have ever occurred on that database connection, zero is returned. 1537 ** 1538 ** ^(If an [INSERT] occurs within a trigger, then the [rowid] of the inserted 1539 ** row is returned by this routine as long as the trigger is running. 1540 ** But once the trigger terminates, the value returned by this routine 1541 ** reverts to the last value inserted before the trigger fired.)^ 1542 ** 1543 ** ^An [INSERT] that fails due to a constraint violation is not a 1544 ** successful [INSERT] and does not change the value returned by this 1545 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1546 ** and INSERT OR ABORT make no changes to the return value of this 1547 ** routine when their insertion fails. ^(When INSERT OR REPLACE 1548 ** encounters a constraint violation, it does not fail. The 1549 ** INSERT continues to completion after deleting rows that caused 1550 ** the constraint problem so INSERT OR REPLACE will always change 1551 ** the return value of this interface.)^ 1552 ** 1553 ** ^For the purposes of this routine, an [INSERT] is considered to 1554 ** be successful even if it is subsequently rolled back. 1555 ** 1556 ** This function is accessible to SQL statements via the 1557 ** [last_insert_rowid() SQL function]. 1558 ** 1559 ** If a separate thread performs a new [INSERT] on the same 1560 ** database connection while the [sqlite3_last_insert_rowid()] 1561 ** function is running and thus changes the last insert [rowid], 1562 ** then the value returned by [sqlite3_last_insert_rowid()] is 1563 ** unpredictable and might not equal either the old or the new 1564 ** last insert [rowid]. 1565 */ 1566 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 1567 1568 /* 1569 ** CAPI3REF: Count The Number Of Rows Modified 1570 ** 1571 ** ^This function returns the number of database rows that were changed 1572 ** or inserted or deleted by the most recently completed SQL statement 1573 ** on the [database connection] specified by the first parameter. 1574 ** ^(Only changes that are directly specified by the [INSERT], [UPDATE], 1575 ** or [DELETE] statement are counted. Auxiliary changes caused by 1576 ** triggers or [foreign key actions] are not counted.)^ Use the 1577 ** [sqlite3_total_changes()] function to find the total number of changes 1578 ** including changes caused by triggers and foreign key actions. 1579 ** 1580 ** ^Changes to a view that are simulated by an [INSTEAD OF trigger] 1581 ** are not counted. Only real table changes are counted. 1582 ** 1583 ** ^(A "row change" is a change to a single row of a single table 1584 ** caused by an INSERT, DELETE, or UPDATE statement. Rows that 1585 ** are changed as side effects of [REPLACE] constraint resolution, 1586 ** rollback, ABORT processing, [DROP TABLE], or by any other 1587 ** mechanisms do not count as direct row changes.)^ 1588 ** 1589 ** A "trigger context" is a scope of execution that begins and 1590 ** ends with the script of a [CREATE TRIGGER | trigger]. 1591 ** Most SQL statements are 1592 ** evaluated outside of any trigger. This is the "top level" 1593 ** trigger context. If a trigger fires from the top level, a 1594 ** new trigger context is entered for the duration of that one 1595 ** trigger. Subtriggers create subcontexts for their duration. 1596 ** 1597 ** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does 1598 ** not create a new trigger context. 1599 ** 1600 ** ^This function returns the number of direct row changes in the 1601 ** most recent INSERT, UPDATE, or DELETE statement within the same 1602 ** trigger context. 1603 ** 1604 ** ^Thus, when called from the top level, this function returns the 1605 ** number of changes in the most recent INSERT, UPDATE, or DELETE 1606 ** that also occurred at the top level. ^(Within the body of a trigger, 1607 ** the sqlite3_changes() interface can be called to find the number of 1608 ** changes in the most recently completed INSERT, UPDATE, or DELETE 1609 ** statement within the body of the same trigger. 1610 ** However, the number returned does not include changes 1611 ** caused by subtriggers since those have their own context.)^ 1612 ** 1613 ** See also the [sqlite3_total_changes()] interface, the 1614 ** [count_changes pragma], and the [changes() SQL function]. 1615 ** 1616 ** If a separate thread makes changes on the same database connection 1617 ** while [sqlite3_changes()] is running then the value returned 1618 ** is unpredictable and not meaningful. 1619 */ 1620 SQLITE_API int sqlite3_changes(sqlite3*); 1621 1622 /* 1623 ** CAPI3REF: Total Number Of Rows Modified 1624 ** 1625 ** ^This function returns the number of row changes caused by [INSERT], 1626 ** [UPDATE] or [DELETE] statements since the [database connection] was opened. 1627 ** ^(The count returned by sqlite3_total_changes() includes all changes 1628 ** from all [CREATE TRIGGER | trigger] contexts and changes made by 1629 ** [foreign key actions]. However, 1630 ** the count does not include changes used to implement [REPLACE] constraints, 1631 ** do rollbacks or ABORT processing, or [DROP TABLE] processing. The 1632 ** count does not include rows of views that fire an [INSTEAD OF trigger], 1633 ** though if the INSTEAD OF trigger makes changes of its own, those changes 1634 ** are counted.)^ 1635 ** ^The sqlite3_total_changes() function counts the changes as soon as 1636 ** the statement that makes them is completed (when the statement handle 1637 ** is passed to [sqlite3_reset()] or [sqlite3_finalize()]). 1638 ** 1639 ** See also the [sqlite3_changes()] interface, the 1640 ** [count_changes pragma], and the [total_changes() SQL function]. 1641 ** 1642 ** If a separate thread makes changes on the same database connection 1643 ** while [sqlite3_total_changes()] is running then the value 1644 ** returned is unpredictable and not meaningful. 1645 */ 1646 SQLITE_API int sqlite3_total_changes(sqlite3*); 1647 1648 /* 1649 ** CAPI3REF: Interrupt A Long-Running Query 1650 ** 1651 ** ^This function causes any pending database operation to abort and 1652 ** return at its earliest opportunity. This routine is typically 1653 ** called in response to a user action such as pressing "Cancel" 1654 ** or Ctrl-C where the user wants a long query operation to halt 1655 ** immediately. 1656 ** 1657 ** ^It is safe to call this routine from a thread different from the 1658 ** thread that is currently running the database operation. But it 1659 ** is not safe to call this routine with a [database connection] that 1660 ** is closed or might close before sqlite3_interrupt() returns. 1661 ** 1662 ** ^If an SQL operation is very nearly finished at the time when 1663 ** sqlite3_interrupt() is called, then it might not have an opportunity 1664 ** to be interrupted and might continue to completion. 1665 ** 1666 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 1667 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 1668 ** that is inside an explicit transaction, then the entire transaction 1669 ** will be rolled back automatically. 1670 ** 1671 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 1672 ** SQL statements on [database connection] D complete. ^Any new SQL statements 1673 ** that are started after the sqlite3_interrupt() call and before the 1674 ** running statements reaches zero are interrupted as if they had been 1675 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 1676 ** that are started after the running statement count reaches zero are 1677 ** not effected by the sqlite3_interrupt(). 1678 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 1679 ** SQL statements is a no-op and has no effect on SQL statements 1680 ** that are started after the sqlite3_interrupt() call returns. 1681 ** 1682 ** If the database connection closes while [sqlite3_interrupt()] 1683 ** is running then bad things will likely happen. 1684 */ 1685 SQLITE_API void sqlite3_interrupt(sqlite3*); 1686 1687 /* 1688 ** CAPI3REF: Determine If An SQL Statement Is Complete 1689 ** 1690 ** These routines are useful during command-line input to determine if the 1691 ** currently entered text seems to form a complete SQL statement or 1692 ** if additional input is needed before sending the text into 1693 ** SQLite for parsing. ^These routines return 1 if the input string 1694 ** appears to be a complete SQL statement. ^A statement is judged to be 1695 ** complete if it ends with a semicolon token and is not a prefix of a 1696 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 1697 ** string literals or quoted identifier names or comments are not 1698 ** independent tokens (they are part of the token in which they are 1699 ** embedded) and thus do not count as a statement terminator. ^Whitespace 1700 ** and comments that follow the final semicolon are ignored. 1701 ** 1702 ** ^These routines return 0 if the statement is incomplete. ^If a 1703 ** memory allocation fails, then SQLITE_NOMEM is returned. 1704 ** 1705 ** ^These routines do not parse the SQL statements thus 1706 ** will not detect syntactically incorrect SQL. 1707 ** 1708 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 1709 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 1710 ** automatically by sqlite3_complete16(). If that initialization fails, 1711 ** then the return value from sqlite3_complete16() will be non-zero 1712 ** regardless of whether or not the input SQL is complete.)^ 1713 ** 1714 ** The input to [sqlite3_complete()] must be a zero-terminated 1715 ** UTF-8 string. 1716 ** 1717 ** The input to [sqlite3_complete16()] must be a zero-terminated 1718 ** UTF-16 string in native byte order. 1719 */ 1720 SQLITE_API int sqlite3_complete(const char *sql); 1721 SQLITE_API int sqlite3_complete16(const void *sql); 1722 1723 /* 1724 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 1725 ** 1726 ** ^This routine sets a callback function that might be invoked whenever 1727 ** an attempt is made to open a database table that another thread 1728 ** or process has locked. 1729 ** 1730 ** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] 1731 ** is returned immediately upon encountering the lock. ^If the busy callback 1732 ** is not NULL, then the callback might be invoked with two arguments. 1733 ** 1734 ** ^The first argument to the busy handler is a copy of the void* pointer which 1735 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 1736 ** the busy handler callback is the number of times that the busy handler has 1737 ** been invoked for this locking event. ^If the 1738 ** busy callback returns 0, then no additional attempts are made to 1739 ** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. 1740 ** ^If the callback returns non-zero, then another attempt 1741 ** is made to open the database for reading and the cycle repeats. 1742 ** 1743 ** The presence of a busy handler does not guarantee that it will be invoked 1744 ** when there is lock contention. ^If SQLite determines that invoking the busy 1745 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 1746 ** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. 1747 ** Consider a scenario where one process is holding a read lock that 1748 ** it is trying to promote to a reserved lock and 1749 ** a second process is holding a reserved lock that it is trying 1750 ** to promote to an exclusive lock. The first process cannot proceed 1751 ** because it is blocked by the second and the second process cannot 1752 ** proceed because it is blocked by the first. If both processes 1753 ** invoke the busy handlers, neither will make any progress. Therefore, 1754 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 1755 ** will induce the first process to release its read lock and allow 1756 ** the second process to proceed. 1757 ** 1758 ** ^The default busy callback is NULL. 1759 ** 1760 ** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] 1761 ** when SQLite is in the middle of a large transaction where all the 1762 ** changes will not fit into the in-memory cache. SQLite will 1763 ** already hold a RESERVED lock on the database file, but it needs 1764 ** to promote this lock to EXCLUSIVE so that it can spill cache 1765 ** pages into the database file without harm to concurrent 1766 ** readers. ^If it is unable to promote the lock, then the in-memory 1767 ** cache will be left in an inconsistent state and so the error 1768 ** code is promoted from the relatively benign [SQLITE_BUSY] to 1769 ** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion 1770 ** forces an automatic rollback of the changes. See the 1771 ** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError"> 1772 ** CorruptionFollowingBusyError</a> wiki page for a discussion of why 1773 ** this is important. 1774 ** 1775 ** ^(There can only be a single busy handler defined for each 1776 ** [database connection]. Setting a new busy handler clears any 1777 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 1778 ** will also set or clear the busy handler. 1779 ** 1780 ** The busy callback should not take any actions which modify the 1781 ** database connection that invoked the busy handler. Any such actions 1782 ** result in undefined behavior. 1783 ** 1784 ** A busy handler must not close the database connection 1785 ** or [prepared statement] that invoked the busy handler. 1786 */ 1787 SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 1788 1789 /* 1790 ** CAPI3REF: Set A Busy Timeout 1791 ** 1792 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 1793 ** for a specified amount of time when a table is locked. ^The handler 1794 ** will sleep multiple times until at least "ms" milliseconds of sleeping 1795 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 1796 ** the handler returns 0 which causes [sqlite3_step()] to return 1797 ** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. 1798 ** 1799 ** ^Calling this routine with an argument less than or equal to zero 1800 ** turns off all busy handlers. 1801 ** 1802 ** ^(There can only be a single busy handler for a particular 1803 ** [database connection] any any given moment. If another busy handler 1804 ** was defined (using [sqlite3_busy_handler()]) prior to calling 1805 ** this routine, that other busy handler is cleared.)^ 1806 */ 1807 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 1808 1809 /* 1810 ** CAPI3REF: Convenience Routines For Running Queries 1811 ** 1812 ** This is a legacy interface that is preserved for backwards compatibility. 1813 ** Use of this interface is not recommended. 1814 ** 1815 ** Definition: A <b>result table</b> is memory data structure created by the 1816 ** [sqlite3_get_table()] interface. A result table records the 1817 ** complete query results from one or more queries. 1818 ** 1819 ** The table conceptually has a number of rows and columns. But 1820 ** these numbers are not part of the result table itself. These 1821 ** numbers are obtained separately. Let N be the number of rows 1822 ** and M be the number of columns. 1823 ** 1824 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 1825 ** There are (N+1)*M elements in the array. The first M pointers point 1826 ** to zero-terminated strings that contain the names of the columns. 1827 ** The remaining entries all point to query results. NULL values result 1828 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 1829 ** string representation as returned by [sqlite3_column_text()]. 1830 ** 1831 ** A result table might consist of one or more memory allocations. 1832 ** It is not safe to pass a result table directly to [sqlite3_free()]. 1833 ** A result table should be deallocated using [sqlite3_free_table()]. 1834 ** 1835 ** ^(As an example of the result table format, suppose a query result 1836 ** is as follows: 1837 ** 1838 ** <blockquote><pre> 1839 ** Name | Age 1840 ** ----------------------- 1841 ** Alice | 43 1842 ** Bob | 28 1843 ** Cindy | 21 1844 ** </pre></blockquote> 1845 ** 1846 ** There are two column (M==2) and three rows (N==3). Thus the 1847 ** result table has 8 entries. Suppose the result table is stored 1848 ** in an array names azResult. Then azResult holds this content: 1849 ** 1850 ** <blockquote><pre> 1851 ** azResult[0] = "Name"; 1852 ** azResult[1] = "Age"; 1853 ** azResult[2] = "Alice"; 1854 ** azResult[3] = "43"; 1855 ** azResult[4] = "Bob"; 1856 ** azResult[5] = "28"; 1857 ** azResult[6] = "Cindy"; 1858 ** azResult[7] = "21"; 1859 ** </pre></blockquote>)^ 1860 ** 1861 ** ^The sqlite3_get_table() function evaluates one or more 1862 ** semicolon-separated SQL statements in the zero-terminated UTF-8 1863 ** string of its 2nd parameter and returns a result table to the 1864 ** pointer given in its 3rd parameter. 1865 ** 1866 ** After the application has finished with the result from sqlite3_get_table(), 1867 ** it must pass the result table pointer to sqlite3_free_table() in order to 1868 ** release the memory that was malloced. Because of the way the 1869 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 1870 ** function must not try to call [sqlite3_free()] directly. Only 1871 ** [sqlite3_free_table()] is able to release the memory properly and safely. 1872 ** 1873 ** The sqlite3_get_table() interface is implemented as a wrapper around 1874 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 1875 ** to any internal data structures of SQLite. It uses only the public 1876 ** interface defined here. As a consequence, errors that occur in the 1877 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 1878 ** reflected in subsequent calls to [sqlite3_errcode()] or 1879 ** [sqlite3_errmsg()]. 1880 */ 1881 SQLITE_API int sqlite3_get_table( 1882 sqlite3 *db, /* An open database */ 1883 const char *zSql, /* SQL to be evaluated */ 1884 char ***pazResult, /* Results of the query */ 1885 int *pnRow, /* Number of result rows written here */ 1886 int *pnColumn, /* Number of result columns written here */ 1887 char **pzErrmsg /* Error msg written here */ 1888 ); 1889 SQLITE_API void sqlite3_free_table(char **result); 1890 1891 /* 1892 ** CAPI3REF: Formatted String Printing Functions 1893 ** 1894 ** These routines are work-alikes of the "printf()" family of functions 1895 ** from the standard C library. 1896 ** 1897 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 1898 ** results into memory obtained from [sqlite3_malloc()]. 1899 ** The strings returned by these two routines should be 1900 ** released by [sqlite3_free()]. ^Both routines return a 1901 ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 1902 ** memory to hold the resulting string. 1903 ** 1904 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 1905 ** the standard C library. The result is written into the 1906 ** buffer supplied as the second parameter whose size is given by 1907 ** the first parameter. Note that the order of the 1908 ** first two parameters is reversed from snprintf().)^ This is an 1909 ** historical accident that cannot be fixed without breaking 1910 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 1911 ** returns a pointer to its buffer instead of the number of 1912 ** characters actually written into the buffer.)^ We admit that 1913 ** the number of characters written would be a more useful return 1914 ** value but we cannot change the implementation of sqlite3_snprintf() 1915 ** now without breaking compatibility. 1916 ** 1917 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 1918 ** guarantees that the buffer is always zero-terminated. ^The first 1919 ** parameter "n" is the total size of the buffer, including space for 1920 ** the zero terminator. So the longest string that can be completely 1921 ** written will be n-1 characters. 1922 ** 1923 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 1924 ** 1925 ** These routines all implement some additional formatting 1926 ** options that are useful for constructing SQL statements. 1927 ** All of the usual printf() formatting options apply. In addition, there 1928 ** is are "%q", "%Q", and "%z" options. 1929 ** 1930 ** ^(The %q option works like %s in that it substitutes a null-terminated 1931 ** string from the argument list. But %q also doubles every '\'' character. 1932 ** %q is designed for use inside a string literal.)^ By doubling each '\'' 1933 ** character it escapes that character and allows it to be inserted into 1934 ** the string. 1935 ** 1936 ** For example, assume the string variable zText contains text as follows: 1937 ** 1938 ** <blockquote><pre> 1939 ** char *zText = "It's a happy day!"; 1940 ** </pre></blockquote> 1941 ** 1942 ** One can use this text in an SQL statement as follows: 1943 ** 1944 ** <blockquote><pre> 1945 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 1946 ** sqlite3_exec(db, zSQL, 0, 0, 0); 1947 ** sqlite3_free(zSQL); 1948 ** </pre></blockquote> 1949 ** 1950 ** Because the %q format string is used, the '\'' character in zText 1951 ** is escaped and the SQL generated is as follows: 1952 ** 1953 ** <blockquote><pre> 1954 ** INSERT INTO table1 VALUES('It''s a happy day!') 1955 ** </pre></blockquote> 1956 ** 1957 ** This is correct. Had we used %s instead of %q, the generated SQL 1958 ** would have looked like this: 1959 ** 1960 ** <blockquote><pre> 1961 ** INSERT INTO table1 VALUES('It's a happy day!'); 1962 ** </pre></blockquote> 1963 ** 1964 ** This second example is an SQL syntax error. As a general rule you should 1965 ** always use %q instead of %s when inserting text into a string literal. 1966 ** 1967 ** ^(The %Q option works like %q except it also adds single quotes around 1968 ** the outside of the total string. Additionally, if the parameter in the 1969 ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 1970 ** single quotes).)^ So, for example, one could say: 1971 ** 1972 ** <blockquote><pre> 1973 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 1974 ** sqlite3_exec(db, zSQL, 0, 0, 0); 1975 ** sqlite3_free(zSQL); 1976 ** </pre></blockquote> 1977 ** 1978 ** The code above will render a correct SQL statement in the zSQL 1979 ** variable even if the zText variable is a NULL pointer. 1980 ** 1981 ** ^(The "%z" formatting option works like "%s" but with the 1982 ** addition that after the string has been read and copied into 1983 ** the result, [sqlite3_free()] is called on the input string.)^ 1984 */ 1985 SQLITE_API char *sqlite3_mprintf(const char*,...); 1986 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 1987 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 1988 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 1989 1990 /* 1991 ** CAPI3REF: Memory Allocation Subsystem 1992 ** 1993 ** The SQLite core uses these three routines for all of its own 1994 ** internal memory allocation needs. "Core" in the previous sentence 1995 ** does not include operating-system specific VFS implementation. The 1996 ** Windows VFS uses native malloc() and free() for some operations. 1997 ** 1998 ** ^The sqlite3_malloc() routine returns a pointer to a block 1999 ** of memory at least N bytes in length, where N is the parameter. 2000 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2001 ** memory, it returns a NULL pointer. ^If the parameter N to 2002 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2003 ** a NULL pointer. 2004 ** 2005 ** ^Calling sqlite3_free() with a pointer previously returned 2006 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2007 ** that it might be reused. ^The sqlite3_free() routine is 2008 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2009 ** to sqlite3_free() is harmless. After being freed, memory 2010 ** should neither be read nor written. Even reading previously freed 2011 ** memory might result in a segmentation fault or other severe error. 2012 ** Memory corruption, a segmentation fault, or other severe error 2013 ** might result if sqlite3_free() is called with a non-NULL pointer that 2014 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2015 ** 2016 ** ^(The sqlite3_realloc() interface attempts to resize a 2017 ** prior memory allocation to be at least N bytes, where N is the 2018 ** second parameter. The memory allocation to be resized is the first 2019 ** parameter.)^ ^ If the first parameter to sqlite3_realloc() 2020 ** is a NULL pointer then its behavior is identical to calling 2021 ** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). 2022 ** ^If the second parameter to sqlite3_realloc() is zero or 2023 ** negative then the behavior is exactly the same as calling 2024 ** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). 2025 ** ^sqlite3_realloc() returns a pointer to a memory allocation 2026 ** of at least N bytes in size or NULL if sufficient memory is unavailable. 2027 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2028 ** of the prior allocation are copied into the beginning of buffer returned 2029 ** by sqlite3_realloc() and the prior allocation is freed. 2030 ** ^If sqlite3_realloc() returns NULL, then the prior allocation 2031 ** is not freed. 2032 ** 2033 ** ^The memory returned by sqlite3_malloc() and sqlite3_realloc() 2034 ** is always aligned to at least an 8 byte boundary, or to a 2035 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2036 ** option is used. 2037 ** 2038 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2039 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2040 ** implementation of these routines to be omitted. That capability 2041 ** is no longer provided. Only built-in memory allocators can be used. 2042 ** 2043 ** The Windows OS interface layer calls 2044 ** the system malloc() and free() directly when converting 2045 ** filenames between the UTF-8 encoding used by SQLite 2046 ** and whatever filename encoding is used by the particular Windows 2047 ** installation. Memory allocation errors are detected, but 2048 ** they are reported back as [SQLITE_CANTOPEN] or 2049 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2050 ** 2051 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2052 ** must be either NULL or else pointers obtained from a prior 2053 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2054 ** not yet been released. 2055 ** 2056 ** The application must not read or write any part of 2057 ** a block of memory after it has been released using 2058 ** [sqlite3_free()] or [sqlite3_realloc()]. 2059 */ 2060 SQLITE_API void *sqlite3_malloc(int); 2061 SQLITE_API void *sqlite3_realloc(void*, int); 2062 SQLITE_API void sqlite3_free(void*); 2063 2064 /* 2065 ** CAPI3REF: Memory Allocator Statistics 2066 ** 2067 ** SQLite provides these two interfaces for reporting on the status 2068 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2069 ** routines, which form the built-in memory allocation subsystem. 2070 ** 2071 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2072 ** of memory currently outstanding (malloced but not freed). 2073 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2074 ** value of [sqlite3_memory_used()] since the high-water mark 2075 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2076 ** [sqlite3_memory_highwater()] include any overhead 2077 ** added by SQLite in its implementation of [sqlite3_malloc()], 2078 ** but not overhead added by the any underlying system library 2079 ** routines that [sqlite3_malloc()] may call. 2080 ** 2081 ** ^The memory high-water mark is reset to the current value of 2082 ** [sqlite3_memory_used()] if and only if the parameter to 2083 ** [sqlite3_memory_highwater()] is true. ^The value returned 2084 ** by [sqlite3_memory_highwater(1)] is the high-water mark 2085 ** prior to the reset. 2086 */ 2087 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2088 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2089 2090 /* 2091 ** CAPI3REF: Pseudo-Random Number Generator 2092 ** 2093 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2094 ** select random [ROWID | ROWIDs] when inserting new records into a table that 2095 ** already uses the largest possible [ROWID]. The PRNG is also used for 2096 ** the build-in random() and randomblob() SQL functions. This interface allows 2097 ** applications to access the same PRNG for other purposes. 2098 ** 2099 ** ^A call to this routine stores N bytes of randomness into buffer P. 2100 ** 2101 ** ^The first time this routine is invoked (either internally or by 2102 ** the application) the PRNG is seeded using randomness obtained 2103 ** from the xRandomness method of the default [sqlite3_vfs] object. 2104 ** ^On all subsequent invocations, the pseudo-randomness is generated 2105 ** internally and without recourse to the [sqlite3_vfs] xRandomness 2106 ** method. 2107 */ 2108 SQLITE_API void sqlite3_randomness(int N, void *P); 2109 2110 /* 2111 ** CAPI3REF: Compile-Time Authorization Callbacks 2112 ** 2113 ** ^This routine registers an authorizer callback with a particular 2114 ** [database connection], supplied in the first argument. 2115 ** ^The authorizer callback is invoked as SQL statements are being compiled 2116 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2117 ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2118 ** points during the compilation process, as logic is being created 2119 ** to perform various actions, the authorizer callback is invoked to 2120 ** see if those actions are allowed. ^The authorizer callback should 2121 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2122 ** specific action but allow the SQL statement to continue to be 2123 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2124 ** rejected with an error. ^If the authorizer callback returns 2125 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2126 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2127 ** the authorizer will fail with an error message. 2128 ** 2129 ** When the callback returns [SQLITE_OK], that means the operation 2130 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 2131 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 2132 ** authorizer will fail with an error message explaining that 2133 ** access is denied. 2134 ** 2135 ** ^The first parameter to the authorizer callback is a copy of the third 2136 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2137 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 2138 ** the particular action to be authorized. ^The third through sixth parameters 2139 ** to the callback are zero-terminated strings that contain additional 2140 ** details about the action to be authorized. 2141 ** 2142 ** ^If the action code is [SQLITE_READ] 2143 ** and the callback returns [SQLITE_IGNORE] then the 2144 ** [prepared statement] statement is constructed to substitute 2145 ** a NULL value in place of the table column that would have 2146 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2147 ** return can be used to deny an untrusted user access to individual 2148 ** columns of a table. 2149 ** ^If the action code is [SQLITE_DELETE] and the callback returns 2150 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2151 ** [truncate optimization] is disabled and all rows are deleted individually. 2152 ** 2153 ** An authorizer is used when [sqlite3_prepare | preparing] 2154 ** SQL statements from an untrusted source, to ensure that the SQL statements 2155 ** do not try to access data they are not allowed to see, or that they do not 2156 ** try to execute malicious statements that damage the database. For 2157 ** example, an application may allow a user to enter arbitrary 2158 ** SQL queries for evaluation by a database. But the application does 2159 ** not want the user to be able to make arbitrary changes to the 2160 ** database. An authorizer could then be put in place while the 2161 ** user-entered SQL is being [sqlite3_prepare | prepared] that 2162 ** disallows everything except [SELECT] statements. 2163 ** 2164 ** Applications that need to process SQL from untrusted sources 2165 ** might also consider lowering resource limits using [sqlite3_limit()] 2166 ** and limiting database size using the [max_page_count] [PRAGMA] 2167 ** in addition to using an authorizer. 2168 ** 2169 ** ^(Only a single authorizer can be in place on a database connection 2170 ** at a time. Each call to sqlite3_set_authorizer overrides the 2171 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2172 ** The authorizer is disabled by default. 2173 ** 2174 ** The authorizer callback must not do anything that will modify 2175 ** the database connection that invoked the authorizer callback. 2176 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2177 ** database connections for the meaning of "modify" in this paragraph. 2178 ** 2179 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2180 ** statement might be re-prepared during [sqlite3_step()] due to a 2181 ** schema change. Hence, the application should ensure that the 2182 ** correct authorizer callback remains in place during the [sqlite3_step()]. 2183 ** 2184 ** ^Note that the authorizer callback is invoked only during 2185 ** [sqlite3_prepare()] or its variants. Authorization is not 2186 ** performed during statement evaluation in [sqlite3_step()], unless 2187 ** as stated in the previous paragraph, sqlite3_step() invokes 2188 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2189 */ 2190 SQLITE_API int sqlite3_set_authorizer( 2191 sqlite3*, 2192 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2193 void *pUserData 2194 ); 2195 2196 /* 2197 ** CAPI3REF: Authorizer Return Codes 2198 ** 2199 ** The [sqlite3_set_authorizer | authorizer callback function] must 2200 ** return either [SQLITE_OK] or one of these two constants in order 2201 ** to signal SQLite whether or not the action is permitted. See the 2202 ** [sqlite3_set_authorizer | authorizer documentation] for additional 2203 ** information. 2204 */ 2205 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2206 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2207 2208 /* 2209 ** CAPI3REF: Authorizer Action Codes 2210 ** 2211 ** The [sqlite3_set_authorizer()] interface registers a callback function 2212 ** that is invoked to authorize certain SQL statement actions. The 2213 ** second parameter to the callback is an integer code that specifies 2214 ** what action is being authorized. These are the integer action codes that 2215 ** the authorizer callback may be passed. 2216 ** 2217 ** These action code values signify what kind of operation is to be 2218 ** authorized. The 3rd and 4th parameters to the authorization 2219 ** callback function will be parameters or NULL depending on which of these 2220 ** codes is used as the second parameter. ^(The 5th parameter to the 2221 ** authorizer callback is the name of the database ("main", "temp", 2222 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2223 ** is the name of the inner-most trigger or view that is responsible for 2224 ** the access attempt or NULL if this access attempt is directly from 2225 ** top-level SQL code. 2226 */ 2227 /******************************************* 3rd ************ 4th ***********/ 2228 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2229 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2230 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2231 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2232 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2233 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2234 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2235 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2236 #define SQLITE_DELETE 9 /* Table Name NULL */ 2237 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2238 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2239 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2240 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2241 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2242 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2243 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2244 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2245 #define SQLITE_INSERT 18 /* Table Name NULL */ 2246 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2247 #define SQLITE_READ 20 /* Table Name Column Name */ 2248 #define SQLITE_SELECT 21 /* NULL NULL */ 2249 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 2250 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 2251 #define SQLITE_ATTACH 24 /* Filename NULL */ 2252 #define SQLITE_DETACH 25 /* Database Name NULL */ 2253 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2254 #define SQLITE_REINDEX 27 /* Index Name NULL */ 2255 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 2256 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2257 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2258 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 2259 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2260 #define SQLITE_COPY 0 /* No longer used */ 2261 2262 /* 2263 ** CAPI3REF: Tracing And Profiling Functions 2264 ** 2265 ** These routines register callback functions that can be used for 2266 ** tracing and profiling the execution of SQL statements. 2267 ** 2268 ** ^The callback function registered by sqlite3_trace() is invoked at 2269 ** various times when an SQL statement is being run by [sqlite3_step()]. 2270 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2271 ** SQL statement text as the statement first begins executing. 2272 ** ^(Additional sqlite3_trace() callbacks might occur 2273 ** as each triggered subprogram is entered. The callbacks for triggers 2274 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 2275 ** 2276 ** ^The callback function registered by sqlite3_profile() is invoked 2277 ** as each SQL statement finishes. ^The profile callback contains 2278 ** the original statement text and an estimate of wall-clock time 2279 ** of how long that statement took to run. ^The profile callback 2280 ** time is in units of nanoseconds, however the current implementation 2281 ** is only capable of millisecond resolution so the six least significant 2282 ** digits in the time are meaningless. Future versions of SQLite 2283 ** might provide greater resolution on the profiler callback. The 2284 ** sqlite3_profile() function is considered experimental and is 2285 ** subject to change in future versions of SQLite. 2286 */ 2287 SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2288 SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, 2289 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2290 2291 /* 2292 ** CAPI3REF: Query Progress Callbacks 2293 ** 2294 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2295 ** function X to be invoked periodically during long running calls to 2296 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2297 ** database connection D. An example use for this 2298 ** interface is to keep a GUI updated during a large query. 2299 ** 2300 ** ^The parameter P is passed through as the only parameter to the 2301 ** callback function X. ^The parameter N is the number of 2302 ** [virtual machine instructions] that are evaluated between successive 2303 ** invocations of the callback X. 2304 ** 2305 ** ^Only a single progress handler may be defined at one time per 2306 ** [database connection]; setting a new progress handler cancels the 2307 ** old one. ^Setting parameter X to NULL disables the progress handler. 2308 ** ^The progress handler is also disabled by setting N to a value less 2309 ** than 1. 2310 ** 2311 ** ^If the progress callback returns non-zero, the operation is 2312 ** interrupted. This feature can be used to implement a 2313 ** "Cancel" button on a GUI progress dialog box. 2314 ** 2315 ** The progress handler callback must not do anything that will modify 2316 ** the database connection that invoked the progress handler. 2317 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2318 ** database connections for the meaning of "modify" in this paragraph. 2319 ** 2320 */ 2321 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2322 2323 /* 2324 ** CAPI3REF: Opening A New Database Connection 2325 ** 2326 ** ^These routines open an SQLite database file whose name is given by the 2327 ** filename argument. ^The filename argument is interpreted as UTF-8 for 2328 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2329 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 2330 ** returned in *ppDb, even if an error occurs. The only exception is that 2331 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2332 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2333 ** object.)^ ^(If the database is opened (and/or created) successfully, then 2334 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2335 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2336 ** an English language description of the error following a failure of any 2337 ** of the sqlite3_open() routines. 2338 ** 2339 ** ^The default encoding for the database will be UTF-8 if 2340 ** sqlite3_open() or sqlite3_open_v2() is called and 2341 ** UTF-16 in the native byte order if sqlite3_open16() is used. 2342 ** 2343 ** Whether or not an error occurs when it is opened, resources 2344 ** associated with the [database connection] handle should be released by 2345 ** passing it to [sqlite3_close()] when it is no longer required. 2346 ** 2347 ** The sqlite3_open_v2() interface works like sqlite3_open() 2348 ** except that it accepts two additional parameters for additional control 2349 ** over the new database connection. ^(The flags parameter to 2350 ** sqlite3_open_v2() can take one of 2351 ** the following three values, optionally combined with the 2352 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2353 ** and/or [SQLITE_OPEN_PRIVATECACHE] flags:)^ 2354 ** 2355 ** <dl> 2356 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2357 ** <dd>The database is opened in read-only mode. If the database does not 2358 ** already exist, an error is returned.</dd>)^ 2359 ** 2360 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2361 ** <dd>The database is opened for reading and writing if possible, or reading 2362 ** only if the file is write protected by the operating system. In either 2363 ** case the database must already exist, otherwise an error is returned.</dd>)^ 2364 ** 2365 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2366 ** <dd>The database is opened for reading and writing, and is created if 2367 ** it does not already exist. This is the behavior that is always used for 2368 ** sqlite3_open() and sqlite3_open16().</dd>)^ 2369 ** </dl> 2370 ** 2371 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 2372 ** combinations shown above or one of the combinations shown above combined 2373 ** with the [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], 2374 ** [SQLITE_OPEN_SHAREDCACHE] and/or [SQLITE_OPEN_PRIVATECACHE] flags, 2375 ** then the behavior is undefined. 2376 ** 2377 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2378 ** opens in the multi-thread [threading mode] as long as the single-thread 2379 ** mode has not been set at compile-time or start-time. ^If the 2380 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2381 ** in the serialized [threading mode] unless single-thread was 2382 ** previously selected at compile-time or start-time. 2383 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2384 ** eligible to use [shared cache mode], regardless of whether or not shared 2385 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 2386 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 2387 ** participate in [shared cache mode] even if it is enabled. 2388 ** 2389 ** ^If the filename is ":memory:", then a private, temporary in-memory database 2390 ** is created for the connection. ^This in-memory database will vanish when 2391 ** the database connection is closed. Future versions of SQLite might 2392 ** make use of additional special filenames that begin with the ":" character. 2393 ** It is recommended that when a database filename actually does begin with 2394 ** a ":" character you should prefix the filename with a pathname such as 2395 ** "./" to avoid ambiguity. 2396 ** 2397 ** ^If the filename is an empty string, then a private, temporary 2398 ** on-disk database will be created. ^This private database will be 2399 ** automatically deleted as soon as the database connection is closed. 2400 ** 2401 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 2402 ** [sqlite3_vfs] object that defines the operating system interface that 2403 ** the new database connection should use. ^If the fourth parameter is 2404 ** a NULL pointer then the default [sqlite3_vfs] object is used. 2405 ** 2406 ** <b>Note to Windows users:</b> The encoding used for the filename argument 2407 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2408 ** codepage is currently defined. Filenames containing international 2409 ** characters must be converted to UTF-8 prior to passing them into 2410 ** sqlite3_open() or sqlite3_open_v2(). 2411 */ 2412 SQLITE_API int sqlite3_open( 2413 const char *filename, /* Database filename (UTF-8) */ 2414 sqlite3 **ppDb /* OUT: SQLite db handle */ 2415 ); 2416 SQLITE_API int sqlite3_open16( 2417 const void *filename, /* Database filename (UTF-16) */ 2418 sqlite3 **ppDb /* OUT: SQLite db handle */ 2419 ); 2420 SQLITE_API int sqlite3_open_v2( 2421 const char *filename, /* Database filename (UTF-8) */ 2422 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2423 int flags, /* Flags */ 2424 const char *zVfs /* Name of VFS module to use */ 2425 ); 2426 2427 /* 2428 ** CAPI3REF: Error Codes And Messages 2429 ** 2430 ** ^The sqlite3_errcode() interface returns the numeric [result code] or 2431 ** [extended result code] for the most recent failed sqlite3_* API call 2432 ** associated with a [database connection]. If a prior API call failed 2433 ** but the most recent API call succeeded, the return value from 2434 ** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode() 2435 ** interface is the same except that it always returns the 2436 ** [extended result code] even when extended result codes are 2437 ** disabled. 2438 ** 2439 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 2440 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 2441 ** ^(Memory to hold the error message string is managed internally. 2442 ** The application does not need to worry about freeing the result. 2443 ** However, the error string might be overwritten or deallocated by 2444 ** subsequent calls to other SQLite interface functions.)^ 2445 ** 2446 ** When the serialized [threading mode] is in use, it might be the 2447 ** case that a second error occurs on a separate thread in between 2448 ** the time of the first error and the call to these interfaces. 2449 ** When that happens, the second error will be reported since these 2450 ** interfaces always report the most recent result. To avoid 2451 ** this, each thread can obtain exclusive use of the [database connection] D 2452 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 2453 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 2454 ** all calls to the interfaces listed here are completed. 2455 ** 2456 ** If an interface fails with SQLITE_MISUSE, that means the interface 2457 ** was invoked incorrectly by the application. In that case, the 2458 ** error code and message may or may not be set. 2459 */ 2460 SQLITE_API int sqlite3_errcode(sqlite3 *db); 2461 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 2462 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 2463 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 2464 2465 /* 2466 ** CAPI3REF: SQL Statement Object 2467 ** KEYWORDS: {prepared statement} {prepared statements} 2468 ** 2469 ** An instance of this object represents a single SQL statement. 2470 ** This object is variously known as a "prepared statement" or a 2471 ** "compiled SQL statement" or simply as a "statement". 2472 ** 2473 ** The life of a statement object goes something like this: 2474 ** 2475 ** <ol> 2476 ** <li> Create the object using [sqlite3_prepare_v2()] or a related 2477 ** function. 2478 ** <li> Bind values to [host parameters] using the sqlite3_bind_*() 2479 ** interfaces. 2480 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 2481 ** <li> Reset the statement using [sqlite3_reset()] then go back 2482 ** to step 2. Do this zero or more times. 2483 ** <li> Destroy the object using [sqlite3_finalize()]. 2484 ** </ol> 2485 ** 2486 ** Refer to documentation on individual methods above for additional 2487 ** information. 2488 */ 2489 typedef struct sqlite3_stmt sqlite3_stmt; 2490 2491 /* 2492 ** CAPI3REF: Run-time Limits 2493 ** 2494 ** ^(This interface allows the size of various constructs to be limited 2495 ** on a connection by connection basis. The first parameter is the 2496 ** [database connection] whose limit is to be set or queried. The 2497 ** second parameter is one of the [limit categories] that define a 2498 ** class of constructs to be size limited. The third parameter is the 2499 ** new limit for that construct.)^ 2500 ** 2501 ** ^If the new limit is a negative number, the limit is unchanged. 2502 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 2503 ** [limits | hard upper bound] 2504 ** set at compile-time by a C preprocessor macro called 2505 ** [limits | SQLITE_MAX_<i>NAME</i>]. 2506 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 2507 ** ^Attempts to increase a limit above its hard upper bound are 2508 ** silently truncated to the hard upper bound. 2509 ** 2510 ** ^Regardless of whether or not the limit was changed, the 2511 ** [sqlite3_limit()] interface returns the prior value of the limit. 2512 ** ^Hence, to find the current value of a limit without changing it, 2513 ** simply invoke this interface with the third parameter set to -1. 2514 ** 2515 ** Run-time limits are intended for use in applications that manage 2516 ** both their own internal database and also databases that are controlled 2517 ** by untrusted external sources. An example application might be a 2518 ** web browser that has its own databases for storing history and 2519 ** separate databases controlled by JavaScript applications downloaded 2520 ** off the Internet. The internal databases can be given the 2521 ** large, default limits. Databases managed by external sources can 2522 ** be given much smaller limits designed to prevent a denial of service 2523 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 2524 ** interface to further control untrusted SQL. The size of the database 2525 ** created by an untrusted script can be contained using the 2526 ** [max_page_count] [PRAGMA]. 2527 ** 2528 ** New run-time limit categories may be added in future releases. 2529 */ 2530 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 2531 2532 /* 2533 ** CAPI3REF: Run-Time Limit Categories 2534 ** KEYWORDS: {limit category} {*limit categories} 2535 ** 2536 ** These constants define various performance limits 2537 ** that can be lowered at run-time using [sqlite3_limit()]. 2538 ** The synopsis of the meanings of the various limits is shown below. 2539 ** Additional information is available at [limits | Limits in SQLite]. 2540 ** 2541 ** <dl> 2542 ** ^(<dt>SQLITE_LIMIT_LENGTH</dt> 2543 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 2544 ** 2545 ** ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 2546 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 2547 ** 2548 ** ^(<dt>SQLITE_LIMIT_COLUMN</dt> 2549 ** <dd>The maximum number of columns in a table definition or in the 2550 ** result set of a [SELECT] or the maximum number of columns in an index 2551 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 2552 ** 2553 ** ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 2554 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 2555 ** 2556 ** ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 2557 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 2558 ** 2559 ** ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 2560 ** <dd>The maximum number of instructions in a virtual machine program 2561 ** used to implement an SQL statement. This limit is not currently 2562 ** enforced, though that might be added in some future release of 2563 ** SQLite.</dd>)^ 2564 ** 2565 ** ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 2566 ** <dd>The maximum number of arguments on a function.</dd>)^ 2567 ** 2568 ** ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 2569 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 2570 ** 2571 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 2572 ** <dd>The maximum length of the pattern argument to the [LIKE] or 2573 ** [GLOB] operators.</dd>)^ 2574 ** 2575 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 2576 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 2577 ** 2578 ** ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 2579 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 2580 ** </dl> 2581 */ 2582 #define SQLITE_LIMIT_LENGTH 0 2583 #define SQLITE_LIMIT_SQL_LENGTH 1 2584 #define SQLITE_LIMIT_COLUMN 2 2585 #define SQLITE_LIMIT_EXPR_DEPTH 3 2586 #define SQLITE_LIMIT_COMPOUND_SELECT 4 2587 #define SQLITE_LIMIT_VDBE_OP 5 2588 #define SQLITE_LIMIT_FUNCTION_ARG 6 2589 #define SQLITE_LIMIT_ATTACHED 7 2590 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 2591 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 2592 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 2593 2594 /* 2595 ** CAPI3REF: Compiling An SQL Statement 2596 ** KEYWORDS: {SQL statement compiler} 2597 ** 2598 ** To execute an SQL query, it must first be compiled into a byte-code 2599 ** program using one of these routines. 2600 ** 2601 ** The first argument, "db", is a [database connection] obtained from a 2602 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 2603 ** [sqlite3_open16()]. The database connection must not have been closed. 2604 ** 2605 ** The second argument, "zSql", is the statement to be compiled, encoded 2606 ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 2607 ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 2608 ** use UTF-16. 2609 ** 2610 ** ^If the nByte argument is less than zero, then zSql is read up to the 2611 ** first zero terminator. ^If nByte is non-negative, then it is the maximum 2612 ** number of bytes read from zSql. ^When nByte is non-negative, the 2613 ** zSql string ends at either the first '\000' or '\u0000' character or 2614 ** the nByte-th byte, whichever comes first. If the caller knows 2615 ** that the supplied string is nul-terminated, then there is a small 2616 ** performance advantage to be gained by passing an nByte parameter that 2617 ** is equal to the number of bytes in the input string <i>including</i> 2618 ** the nul-terminator bytes. 2619 ** 2620 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 2621 ** past the end of the first SQL statement in zSql. These routines only 2622 ** compile the first statement in zSql, so *pzTail is left pointing to 2623 ** what remains uncompiled. 2624 ** 2625 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 2626 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 2627 ** to NULL. ^If the input text contains no SQL (if the input is an empty 2628 ** string or a comment) then *ppStmt is set to NULL. 2629 ** The calling procedure is responsible for deleting the compiled 2630 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 2631 ** ppStmt may not be NULL. 2632 ** 2633 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 2634 ** otherwise an [error code] is returned. 2635 ** 2636 ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 2637 ** recommended for all new programs. The two older interfaces are retained 2638 ** for backwards compatibility, but their use is discouraged. 2639 ** ^In the "v2" interfaces, the prepared statement 2640 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 2641 ** original SQL text. This causes the [sqlite3_step()] interface to 2642 ** behave differently in three ways: 2643 ** 2644 ** <ol> 2645 ** <li> 2646 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 2647 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 2648 ** statement and try to run it again. 2649 ** </li> 2650 ** 2651 ** <li> 2652 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 2653 ** [error codes] or [extended error codes]. ^The legacy behavior was that 2654 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 2655 ** and the application would have to make a second call to [sqlite3_reset()] 2656 ** in order to find the underlying cause of the problem. With the "v2" prepare 2657 ** interfaces, the underlying reason for the error is returned immediately. 2658 ** </li> 2659 ** 2660 ** <li> 2661 ** ^If the specific value bound to [parameter | host parameter] in the 2662 ** WHERE clause might influence the choice of query plan for a statement, 2663 ** then the statement will be automatically recompiled, as if there had been 2664 ** a schema change, on the first [sqlite3_step()] call following any change 2665 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 2666 ** ^The specific value of WHERE-clause [parameter] might influence the 2667 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 2668 ** or [GLOB] operator or if the parameter is compared to an indexed column 2669 ** and the [SQLITE_ENABLE_STAT2] compile-time option is enabled. 2670 ** the 2671 ** </li> 2672 ** </ol> 2673 */ 2674 SQLITE_API int sqlite3_prepare( 2675 sqlite3 *db, /* Database handle */ 2676 const char *zSql, /* SQL statement, UTF-8 encoded */ 2677 int nByte, /* Maximum length of zSql in bytes. */ 2678 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2679 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2680 ); 2681 SQLITE_API int sqlite3_prepare_v2( 2682 sqlite3 *db, /* Database handle */ 2683 const char *zSql, /* SQL statement, UTF-8 encoded */ 2684 int nByte, /* Maximum length of zSql in bytes. */ 2685 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2686 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2687 ); 2688 SQLITE_API int sqlite3_prepare16( 2689 sqlite3 *db, /* Database handle */ 2690 const void *zSql, /* SQL statement, UTF-16 encoded */ 2691 int nByte, /* Maximum length of zSql in bytes. */ 2692 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2693 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2694 ); 2695 SQLITE_API int sqlite3_prepare16_v2( 2696 sqlite3 *db, /* Database handle */ 2697 const void *zSql, /* SQL statement, UTF-16 encoded */ 2698 int nByte, /* Maximum length of zSql in bytes. */ 2699 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2700 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2701 ); 2702 2703 /* 2704 ** CAPI3REF: Retrieving Statement SQL 2705 ** 2706 ** ^This interface can be used to retrieve a saved copy of the original 2707 ** SQL text used to create a [prepared statement] if that statement was 2708 ** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 2709 */ 2710 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 2711 2712 /* 2713 ** CAPI3REF: Determine If An SQL Statement Writes The Database 2714 ** 2715 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 2716 ** and only if the [prepared statement] X makes no direct changes to 2717 ** the content of the database file. 2718 ** 2719 ** Note that [application-defined SQL functions] or 2720 ** [virtual tables] might change the database indirectly as a side effect. 2721 ** ^(For example, if an application defines a function "eval()" that 2722 ** calls [sqlite3_exec()], then the following SQL statement would 2723 ** change the database file through side-effects: 2724 ** 2725 ** <blockquote><pre> 2726 ** SELECT eval('DELETE FROM t1') FROM t2; 2727 ** </pre></blockquote> 2728 ** 2729 ** But because the [SELECT] statement does not change the database file 2730 ** directly, sqlite3_stmt_readonly() would still return true.)^ 2731 ** 2732 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 2733 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 2734 ** since the statements themselves do not actually modify the database but 2735 ** rather they control the timing of when other statements modify the 2736 ** database. ^The [ATTACH] and [DETACH] statements also cause 2737 ** sqlite3_stmt_readonly() to return true since, while those statements 2738 ** change the configuration of a database connection, they do not make 2739 ** changes to the content of the database files on disk. 2740 */ 2741 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 2742 2743 /* 2744 ** CAPI3REF: Dynamically Typed Value Object 2745 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 2746 ** 2747 ** SQLite uses the sqlite3_value object to represent all values 2748 ** that can be stored in a database table. SQLite uses dynamic typing 2749 ** for the values it stores. ^Values stored in sqlite3_value objects 2750 ** can be integers, floating point values, strings, BLOBs, or NULL. 2751 ** 2752 ** An sqlite3_value object may be either "protected" or "unprotected". 2753 ** Some interfaces require a protected sqlite3_value. Other interfaces 2754 ** will accept either a protected or an unprotected sqlite3_value. 2755 ** Every interface that accepts sqlite3_value arguments specifies 2756 ** whether or not it requires a protected sqlite3_value. 2757 ** 2758 ** The terms "protected" and "unprotected" refer to whether or not 2759 ** a mutex is held. An internal mutex is held for a protected 2760 ** sqlite3_value object but no mutex is held for an unprotected 2761 ** sqlite3_value object. If SQLite is compiled to be single-threaded 2762 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 2763 ** or if SQLite is run in one of reduced mutex modes 2764 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 2765 ** then there is no distinction between protected and unprotected 2766 ** sqlite3_value objects and they can be used interchangeably. However, 2767 ** for maximum code portability it is recommended that applications 2768 ** still make the distinction between protected and unprotected 2769 ** sqlite3_value objects even when not strictly required. 2770 ** 2771 ** ^The sqlite3_value objects that are passed as parameters into the 2772 ** implementation of [application-defined SQL functions] are protected. 2773 ** ^The sqlite3_value object returned by 2774 ** [sqlite3_column_value()] is unprotected. 2775 ** Unprotected sqlite3_value objects may only be used with 2776 ** [sqlite3_result_value()] and [sqlite3_bind_value()]. 2777 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 2778 ** interfaces require protected sqlite3_value objects. 2779 */ 2780 typedef struct Mem sqlite3_value; 2781 2782 /* 2783 ** CAPI3REF: SQL Function Context Object 2784 ** 2785 ** The context in which an SQL function executes is stored in an 2786 ** sqlite3_context object. ^A pointer to an sqlite3_context object 2787 ** is always first parameter to [application-defined SQL functions]. 2788 ** The application-defined SQL function implementation will pass this 2789 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 2790 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 2791 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 2792 ** and/or [sqlite3_set_auxdata()]. 2793 */ 2794 typedef struct sqlite3_context sqlite3_context; 2795 2796 /* 2797 ** CAPI3REF: Binding Values To Prepared Statements 2798 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 2799 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 2800 ** 2801 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 2802 ** literals may be replaced by a [parameter] that matches one of following 2803 ** templates: 2804 ** 2805 ** <ul> 2806 ** <li> ? 2807 ** <li> ?NNN 2808 ** <li> :VVV 2809 ** <li> @VVV 2810 ** <li> $VVV 2811 ** </ul> 2812 ** 2813 ** In the templates above, NNN represents an integer literal, 2814 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 2815 ** parameters (also called "host parameter names" or "SQL parameters") 2816 ** can be set using the sqlite3_bind_*() routines defined here. 2817 ** 2818 ** ^The first argument to the sqlite3_bind_*() routines is always 2819 ** a pointer to the [sqlite3_stmt] object returned from 2820 ** [sqlite3_prepare_v2()] or its variants. 2821 ** 2822 ** ^The second argument is the index of the SQL parameter to be set. 2823 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 2824 ** SQL parameter is used more than once, second and subsequent 2825 ** occurrences have the same index as the first occurrence. 2826 ** ^The index for named parameters can be looked up using the 2827 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 2828 ** for "?NNN" parameters is the value of NNN. 2829 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 2830 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 2831 ** 2832 ** ^The third argument is the value to bind to the parameter. 2833 ** 2834 ** ^(In those routines that have a fourth argument, its value is the 2835 ** number of bytes in the parameter. To be clear: the value is the 2836 ** number of <u>bytes</u> in the value, not the number of characters.)^ 2837 ** ^If the fourth parameter is negative, the length of the string is 2838 ** the number of bytes up to the first zero terminator. 2839 ** 2840 ** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and 2841 ** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or 2842 ** string after SQLite has finished with it. ^The destructor is called 2843 ** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(), 2844 ** sqlite3_bind_text(), or sqlite3_bind_text16() fails. 2845 ** ^If the fifth argument is 2846 ** the special value [SQLITE_STATIC], then SQLite assumes that the 2847 ** information is in static, unmanaged space and does not need to be freed. 2848 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 2849 ** SQLite makes its own private copy of the data immediately, before 2850 ** the sqlite3_bind_*() routine returns. 2851 ** 2852 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 2853 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 2854 ** (just an integer to hold its size) while it is being processed. 2855 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 2856 ** content is later written using 2857 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 2858 ** ^A negative value for the zeroblob results in a zero-length BLOB. 2859 ** 2860 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 2861 ** for the [prepared statement] or with a prepared statement for which 2862 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 2863 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 2864 ** routine is passed a [prepared statement] that has been finalized, the 2865 ** result is undefined and probably harmful. 2866 ** 2867 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 2868 ** ^Unbound parameters are interpreted as NULL. 2869 ** 2870 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 2871 ** [error code] if anything goes wrong. 2872 ** ^[SQLITE_RANGE] is returned if the parameter 2873 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 2874 ** 2875 ** See also: [sqlite3_bind_parameter_count()], 2876 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 2877 */ 2878 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 2879 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 2880 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 2881 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 2882 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 2883 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); 2884 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 2885 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 2886 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 2887 2888 /* 2889 ** CAPI3REF: Number Of SQL Parameters 2890 ** 2891 ** ^This routine can be used to find the number of [SQL parameters] 2892 ** in a [prepared statement]. SQL parameters are tokens of the 2893 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 2894 ** placeholders for values that are [sqlite3_bind_blob | bound] 2895 ** to the parameters at a later time. 2896 ** 2897 ** ^(This routine actually returns the index of the largest (rightmost) 2898 ** parameter. For all forms except ?NNN, this will correspond to the 2899 ** number of unique parameters. If parameters of the ?NNN form are used, 2900 ** there may be gaps in the list.)^ 2901 ** 2902 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 2903 ** [sqlite3_bind_parameter_name()], and 2904 ** [sqlite3_bind_parameter_index()]. 2905 */ 2906 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 2907 2908 /* 2909 ** CAPI3REF: Name Of A Host Parameter 2910 ** 2911 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 2912 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 2913 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 2914 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 2915 ** respectively. 2916 ** In other words, the initial ":" or "$" or "@" or "?" 2917 ** is included as part of the name.)^ 2918 ** ^Parameters of the form "?" without a following integer have no name 2919 ** and are referred to as "nameless" or "anonymous parameters". 2920 ** 2921 ** ^The first host parameter has an index of 1, not 0. 2922 ** 2923 ** ^If the value N is out of range or if the N-th parameter is 2924 ** nameless, then NULL is returned. ^The returned string is 2925 ** always in UTF-8 encoding even if the named parameter was 2926 ** originally specified as UTF-16 in [sqlite3_prepare16()] or 2927 ** [sqlite3_prepare16_v2()]. 2928 ** 2929 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 2930 ** [sqlite3_bind_parameter_count()], and 2931 ** [sqlite3_bind_parameter_index()]. 2932 */ 2933 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 2934 2935 /* 2936 ** CAPI3REF: Index Of A Parameter With A Given Name 2937 ** 2938 ** ^Return the index of an SQL parameter given its name. ^The 2939 ** index value returned is suitable for use as the second 2940 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 2941 ** is returned if no matching parameter is found. ^The parameter 2942 ** name must be given in UTF-8 even if the original statement 2943 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 2944 ** 2945 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 2946 ** [sqlite3_bind_parameter_count()], and 2947 ** [sqlite3_bind_parameter_index()]. 2948 */ 2949 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 2950 2951 /* 2952 ** CAPI3REF: Reset All Bindings On A Prepared Statement 2953 ** 2954 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 2955 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 2956 ** ^Use this routine to reset all host parameters to NULL. 2957 */ 2958 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 2959 2960 /* 2961 ** CAPI3REF: Number Of Columns In A Result Set 2962 ** 2963 ** ^Return the number of columns in the result set returned by the 2964 ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 2965 ** statement that does not return data (for example an [UPDATE]). 2966 ** 2967 ** See also: [sqlite3_data_count()] 2968 */ 2969 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 2970 2971 /* 2972 ** CAPI3REF: Column Names In A Result Set 2973 ** 2974 ** ^These routines return the name assigned to a particular column 2975 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 2976 ** interface returns a pointer to a zero-terminated UTF-8 string 2977 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 2978 ** UTF-16 string. ^The first parameter is the [prepared statement] 2979 ** that implements the [SELECT] statement. ^The second parameter is the 2980 ** column number. ^The leftmost column is number 0. 2981 ** 2982 ** ^The returned string pointer is valid until either the [prepared statement] 2983 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 2984 ** reprepared by the first call to [sqlite3_step()] for a particular run 2985 ** or until the next call to 2986 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 2987 ** 2988 ** ^If sqlite3_malloc() fails during the processing of either routine 2989 ** (for example during a conversion from UTF-8 to UTF-16) then a 2990 ** NULL pointer is returned. 2991 ** 2992 ** ^The name of a result column is the value of the "AS" clause for 2993 ** that column, if there is an AS clause. If there is no AS clause 2994 ** then the name of the column is unspecified and may change from 2995 ** one release of SQLite to the next. 2996 */ 2997 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 2998 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 2999 3000 /* 3001 ** CAPI3REF: Source Of Data In A Query Result 3002 ** 3003 ** ^These routines provide a means to determine the database, table, and 3004 ** table column that is the origin of a particular result column in 3005 ** [SELECT] statement. 3006 ** ^The name of the database or table or column can be returned as 3007 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3008 ** the database name, the _table_ routines return the table name, and 3009 ** the origin_ routines return the column name. 3010 ** ^The returned string is valid until the [prepared statement] is destroyed 3011 ** using [sqlite3_finalize()] or until the statement is automatically 3012 ** reprepared by the first call to [sqlite3_step()] for a particular run 3013 ** or until the same information is requested 3014 ** again in a different encoding. 3015 ** 3016 ** ^The names returned are the original un-aliased names of the 3017 ** database, table, and column. 3018 ** 3019 ** ^The first argument to these interfaces is a [prepared statement]. 3020 ** ^These functions return information about the Nth result column returned by 3021 ** the statement, where N is the second function argument. 3022 ** ^The left-most column is column 0 for these routines. 3023 ** 3024 ** ^If the Nth column returned by the statement is an expression or 3025 ** subquery and is not a column value, then all of these functions return 3026 ** NULL. ^These routine might also return NULL if a memory allocation error 3027 ** occurs. ^Otherwise, they return the name of the attached database, table, 3028 ** or column that query result column was extracted from. 3029 ** 3030 ** ^As with all other SQLite APIs, those whose names end with "16" return 3031 ** UTF-16 encoded strings and the other functions return UTF-8. 3032 ** 3033 ** ^These APIs are only available if the library was compiled with the 3034 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3035 ** 3036 ** If two or more threads call one or more of these routines against the same 3037 ** prepared statement and column at the same time then the results are 3038 ** undefined. 3039 ** 3040 ** If two or more threads call one or more 3041 ** [sqlite3_column_database_name | column metadata interfaces] 3042 ** for the same [prepared statement] and result column 3043 ** at the same time then the results are undefined. 3044 */ 3045 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 3046 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 3047 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 3048 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 3049 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 3050 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 3051 3052 /* 3053 ** CAPI3REF: Declared Datatype Of A Query Result 3054 ** 3055 ** ^(The first parameter is a [prepared statement]. 3056 ** If this statement is a [SELECT] statement and the Nth column of the 3057 ** returned result set of that [SELECT] is a table column (not an 3058 ** expression or subquery) then the declared type of the table 3059 ** column is returned.)^ ^If the Nth column of the result set is an 3060 ** expression or subquery, then a NULL pointer is returned. 3061 ** ^The returned string is always UTF-8 encoded. 3062 ** 3063 ** ^(For example, given the database schema: 3064 ** 3065 ** CREATE TABLE t1(c1 VARIANT); 3066 ** 3067 ** and the following statement to be compiled: 3068 ** 3069 ** SELECT c1 + 1, c1 FROM t1; 3070 ** 3071 ** this routine would return the string "VARIANT" for the second result 3072 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3073 ** 3074 ** ^SQLite uses dynamic run-time typing. ^So just because a column 3075 ** is declared to contain a particular type does not mean that the 3076 ** data stored in that column is of the declared type. SQLite is 3077 ** strongly typed, but the typing is dynamic not static. ^Type 3078 ** is associated with individual values, not with the containers 3079 ** used to hold those values. 3080 */ 3081 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 3082 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 3083 3084 /* 3085 ** CAPI3REF: Evaluate An SQL Statement 3086 ** 3087 ** After a [prepared statement] has been prepared using either 3088 ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3089 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3090 ** must be called one or more times to evaluate the statement. 3091 ** 3092 ** The details of the behavior of the sqlite3_step() interface depend 3093 ** on whether the statement was prepared using the newer "v2" interface 3094 ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3095 ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3096 ** new "v2" interface is recommended for new applications but the legacy 3097 ** interface will continue to be supported. 3098 ** 3099 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 3100 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3101 ** ^With the "v2" interface, any of the other [result codes] or 3102 ** [extended result codes] might be returned as well. 3103 ** 3104 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 3105 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 3106 ** or occurs outside of an explicit transaction, then you can retry the 3107 ** statement. If the statement is not a [COMMIT] and occurs within a 3108 ** explicit transaction then you should rollback the transaction before 3109 ** continuing. 3110 ** 3111 ** ^[SQLITE_DONE] means that the statement has finished executing 3112 ** successfully. sqlite3_step() should not be called again on this virtual 3113 ** machine without first calling [sqlite3_reset()] to reset the virtual 3114 ** machine back to its initial state. 3115 ** 3116 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 3117 ** is returned each time a new row of data is ready for processing by the 3118 ** caller. The values may be accessed using the [column access functions]. 3119 ** sqlite3_step() is called again to retrieve the next row of data. 3120 ** 3121 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 3122 ** violation) has occurred. sqlite3_step() should not be called again on 3123 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 3124 ** ^With the legacy interface, a more specific error code (for example, 3125 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3126 ** can be obtained by calling [sqlite3_reset()] on the 3127 ** [prepared statement]. ^In the "v2" interface, 3128 ** the more specific error code is returned directly by sqlite3_step(). 3129 ** 3130 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3131 ** Perhaps it was called on a [prepared statement] that has 3132 ** already been [sqlite3_finalize | finalized] or on one that had 3133 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3134 ** be the case that the same database connection is being used by two or 3135 ** more threads at the same moment in time. 3136 ** 3137 ** For all versions of SQLite up to and including 3.6.23.1, a call to 3138 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 3139 ** other than [SQLITE_ROW] before any subsequent invocation of 3140 ** sqlite3_step(). Failure to reset the prepared statement using 3141 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 3142 ** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 3143 ** calling [sqlite3_reset()] automatically in this circumstance rather 3144 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 3145 ** break because any application that ever receives an SQLITE_MISUSE error 3146 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 3147 ** can be used to restore the legacy behavior. 3148 ** 3149 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 3150 ** API always returns a generic error code, [SQLITE_ERROR], following any 3151 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 3152 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 3153 ** specific [error codes] that better describes the error. 3154 ** We admit that this is a goofy design. The problem has been fixed 3155 ** with the "v2" interface. If you prepare all of your SQL statements 3156 ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3157 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 3158 ** then the more specific [error codes] are returned directly 3159 ** by sqlite3_step(). The use of the "v2" interface is recommended. 3160 */ 3161 SQLITE_API int sqlite3_step(sqlite3_stmt*); 3162 3163 /* 3164 ** CAPI3REF: Number of columns in a result set 3165 ** 3166 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 3167 ** current row of the result set of [prepared statement] P. 3168 ** ^If prepared statement P does not have results ready to return 3169 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 3170 ** interfaces) then sqlite3_data_count(P) returns 0. 3171 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 3172 ** 3173 ** See also: [sqlite3_column_count()] 3174 */ 3175 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 3176 3177 /* 3178 ** CAPI3REF: Fundamental Datatypes 3179 ** KEYWORDS: SQLITE_TEXT 3180 ** 3181 ** ^(Every value in SQLite has one of five fundamental datatypes: 3182 ** 3183 ** <ul> 3184 ** <li> 64-bit signed integer 3185 ** <li> 64-bit IEEE floating point number 3186 ** <li> string 3187 ** <li> BLOB 3188 ** <li> NULL 3189 ** </ul>)^ 3190 ** 3191 ** These constants are codes for each of those types. 3192 ** 3193 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3194 ** for a completely different meaning. Software that links against both 3195 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 3196 ** SQLITE_TEXT. 3197 */ 3198 #define SQLITE_INTEGER 1 3199 #define SQLITE_FLOAT 2 3200 #define SQLITE_BLOB 4 3201 #define SQLITE_NULL 5 3202 #ifdef SQLITE_TEXT 3203 # undef SQLITE_TEXT 3204 #else 3205 # define SQLITE_TEXT 3 3206 #endif 3207 #define SQLITE3_TEXT 3 3208 3209 /* 3210 ** CAPI3REF: Result Values From A Query 3211 ** KEYWORDS: {column access functions} 3212 ** 3213 ** These routines form the "result set" interface. 3214 ** 3215 ** ^These routines return information about a single column of the current 3216 ** result row of a query. ^In every case the first argument is a pointer 3217 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 3218 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 3219 ** and the second argument is the index of the column for which information 3220 ** should be returned. ^The leftmost column of the result set has the index 0. 3221 ** ^The number of columns in the result can be determined using 3222 ** [sqlite3_column_count()]. 3223 ** 3224 ** If the SQL statement does not currently point to a valid row, or if the 3225 ** column index is out of range, the result is undefined. 3226 ** These routines may only be called when the most recent call to 3227 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3228 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 3229 ** If any of these routines are called after [sqlite3_reset()] or 3230 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3231 ** something other than [SQLITE_ROW], the results are undefined. 3232 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3233 ** are called from a different thread while any of these routines 3234 ** are pending, then the results are undefined. 3235 ** 3236 ** ^The sqlite3_column_type() routine returns the 3237 ** [SQLITE_INTEGER | datatype code] for the initial data type 3238 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 3239 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3240 ** returned by sqlite3_column_type() is only meaningful if no type 3241 ** conversions have occurred as described below. After a type conversion, 3242 ** the value returned by sqlite3_column_type() is undefined. Future 3243 ** versions of SQLite may change the behavior of sqlite3_column_type() 3244 ** following a type conversion. 3245 ** 3246 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3247 ** routine returns the number of bytes in that BLOB or string. 3248 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3249 ** the string to UTF-8 and then returns the number of bytes. 3250 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 3251 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 3252 ** the number of bytes in that string. 3253 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 3254 ** 3255 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 3256 ** routine returns the number of bytes in that BLOB or string. 3257 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 3258 ** the string to UTF-16 and then returns the number of bytes. 3259 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 3260 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 3261 ** the number of bytes in that string. 3262 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 3263 ** 3264 ** ^The values returned by [sqlite3_column_bytes()] and 3265 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 3266 ** of the string. ^For clarity: the values returned by 3267 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 3268 ** bytes in the string, not the number of characters. 3269 ** 3270 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 3271 ** even empty strings, are always zero terminated. ^The return 3272 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 3273 ** 3274 ** ^The object returned by [sqlite3_column_value()] is an 3275 ** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 3276 ** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 3277 ** If the [unprotected sqlite3_value] object returned by 3278 ** [sqlite3_column_value()] is used in any other way, including calls 3279 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 3280 ** or [sqlite3_value_bytes()], then the behavior is undefined. 3281 ** 3282 ** These routines attempt to convert the value where appropriate. ^For 3283 ** example, if the internal representation is FLOAT and a text result 3284 ** is requested, [sqlite3_snprintf()] is used internally to perform the 3285 ** conversion automatically. ^(The following table details the conversions 3286 ** that are applied: 3287 ** 3288 ** <blockquote> 3289 ** <table border="1"> 3290 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 3291 ** 3292 ** <tr><td> NULL <td> INTEGER <td> Result is 0 3293 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 3294 ** <tr><td> NULL <td> TEXT <td> Result is NULL pointer 3295 ** <tr><td> NULL <td> BLOB <td> Result is NULL pointer 3296 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 3297 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 3298 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 3299 ** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer 3300 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 3301 ** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT 3302 ** <tr><td> TEXT <td> INTEGER <td> Use atoi() 3303 ** <tr><td> TEXT <td> FLOAT <td> Use atof() 3304 ** <tr><td> TEXT <td> BLOB <td> No change 3305 ** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi() 3306 ** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof() 3307 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 3308 ** </table> 3309 ** </blockquote>)^ 3310 ** 3311 ** The table above makes reference to standard C library functions atoi() 3312 ** and atof(). SQLite does not really use these functions. It has its 3313 ** own equivalent internal routines. The atoi() and atof() names are 3314 ** used in the table for brevity and because they are familiar to most 3315 ** C programmers. 3316 ** 3317 ** Note that when type conversions occur, pointers returned by prior 3318 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 3319 ** sqlite3_column_text16() may be invalidated. 3320 ** Type conversions and pointer invalidations might occur 3321 ** in the following cases: 3322 ** 3323 ** <ul> 3324 ** <li> The initial content is a BLOB and sqlite3_column_text() or 3325 ** sqlite3_column_text16() is called. A zero-terminator might 3326 ** need to be added to the string.</li> 3327 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 3328 ** sqlite3_column_text16() is called. The content must be converted 3329 ** to UTF-16.</li> 3330 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 3331 ** sqlite3_column_text() is called. The content must be converted 3332 ** to UTF-8.</li> 3333 ** </ul> 3334 ** 3335 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 3336 ** not invalidate a prior pointer, though of course the content of the buffer 3337 ** that the prior pointer references will have been modified. Other kinds 3338 ** of conversion are done in place when it is possible, but sometimes they 3339 ** are not possible and in those cases prior pointers are invalidated. 3340 ** 3341 ** The safest and easiest to remember policy is to invoke these routines 3342 ** in one of the following ways: 3343 ** 3344 ** <ul> 3345 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 3346 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 3347 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 3348 ** </ul> 3349 ** 3350 ** In other words, you should call sqlite3_column_text(), 3351 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 3352 ** into the desired format, then invoke sqlite3_column_bytes() or 3353 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 3354 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 3355 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 3356 ** with calls to sqlite3_column_bytes(). 3357 ** 3358 ** ^The pointers returned are valid until a type conversion occurs as 3359 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 3360 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 3361 ** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned 3362 ** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 3363 ** [sqlite3_free()]. 3364 ** 3365 ** ^(If a memory allocation error occurs during the evaluation of any 3366 ** of these routines, a default value is returned. The default value 3367 ** is either the integer 0, the floating point number 0.0, or a NULL 3368 ** pointer. Subsequent calls to [sqlite3_errcode()] will return 3369 ** [SQLITE_NOMEM].)^ 3370 */ 3371 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 3372 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 3373 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 3374 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 3375 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 3376 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 3377 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 3378 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 3379 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 3380 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 3381 3382 /* 3383 ** CAPI3REF: Destroy A Prepared Statement Object 3384 ** 3385 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 3386 ** ^If the most recent evaluation of the statement encountered no errors or 3387 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 3388 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 3389 ** sqlite3_finalize(S) returns the appropriate [error code] or 3390 ** [extended error code]. 3391 ** 3392 ** ^The sqlite3_finalize(S) routine can be called at any point during 3393 ** the life cycle of [prepared statement] S: 3394 ** before statement S is ever evaluated, after 3395 ** one or more calls to [sqlite3_reset()], or after any call 3396 ** to [sqlite3_step()] regardless of whether or not the statement has 3397 ** completed execution. 3398 ** 3399 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 3400 ** 3401 ** The application must finalize every [prepared statement] in order to avoid 3402 ** resource leaks. It is a grievous error for the application to try to use 3403 ** a prepared statement after it has been finalized. Any use of a prepared 3404 ** statement after it has been finalized can result in undefined and 3405 ** undesirable behavior such as segfaults and heap corruption. 3406 */ 3407 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 3408 3409 /* 3410 ** CAPI3REF: Reset A Prepared Statement Object 3411 ** 3412 ** The sqlite3_reset() function is called to reset a [prepared statement] 3413 ** object back to its initial state, ready to be re-executed. 3414 ** ^Any SQL statement variables that had values bound to them using 3415 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 3416 ** Use [sqlite3_clear_bindings()] to reset the bindings. 3417 ** 3418 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 3419 ** back to the beginning of its program. 3420 ** 3421 ** ^If the most recent call to [sqlite3_step(S)] for the 3422 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 3423 ** or if [sqlite3_step(S)] has never before been called on S, 3424 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 3425 ** 3426 ** ^If the most recent call to [sqlite3_step(S)] for the 3427 ** [prepared statement] S indicated an error, then 3428 ** [sqlite3_reset(S)] returns an appropriate [error code]. 3429 ** 3430 ** ^The [sqlite3_reset(S)] interface does not change the values 3431 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 3432 */ 3433 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 3434 3435 /* 3436 ** CAPI3REF: Create Or Redefine SQL Functions 3437 ** KEYWORDS: {function creation routines} 3438 ** KEYWORDS: {application-defined SQL function} 3439 ** KEYWORDS: {application-defined SQL functions} 3440 ** 3441 ** ^These functions (collectively known as "function creation routines") 3442 ** are used to add SQL functions or aggregates or to redefine the behavior 3443 ** of existing SQL functions or aggregates. The only differences between 3444 ** these routines are the text encoding expected for 3445 ** the second parameter (the name of the function being created) 3446 ** and the presence or absence of a destructor callback for 3447 ** the application data pointer. 3448 ** 3449 ** ^The first parameter is the [database connection] to which the SQL 3450 ** function is to be added. ^If an application uses more than one database 3451 ** connection then application-defined SQL functions must be added 3452 ** to each database connection separately. 3453 ** 3454 ** ^The second parameter is the name of the SQL function to be created or 3455 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 3456 ** representation, exclusive of the zero-terminator. ^Note that the name 3457 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 3458 ** ^Any attempt to create a function with a longer name 3459 ** will result in [SQLITE_MISUSE] being returned. 3460 ** 3461 ** ^The third parameter (nArg) 3462 ** is the number of arguments that the SQL function or 3463 ** aggregate takes. ^If this parameter is -1, then the SQL function or 3464 ** aggregate may take any number of arguments between 0 and the limit 3465 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 3466 ** parameter is less than -1 or greater than 127 then the behavior is 3467 ** undefined. 3468 ** 3469 ** ^The fourth parameter, eTextRep, specifies what 3470 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 3471 ** its parameters. Every SQL function implementation must be able to work 3472 ** with UTF-8, UTF-16le, or UTF-16be. But some implementations may be 3473 ** more efficient with one encoding than another. ^An application may 3474 ** invoke sqlite3_create_function() or sqlite3_create_function16() multiple 3475 ** times with the same function but with different values of eTextRep. 3476 ** ^When multiple implementations of the same function are available, SQLite 3477 ** will pick the one that involves the least amount of data conversion. 3478 ** If there is only a single implementation which does not care what text 3479 ** encoding is used, then the fourth argument should be [SQLITE_ANY]. 3480 ** 3481 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 3482 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 3483 ** 3484 ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 3485 ** pointers to C-language functions that implement the SQL function or 3486 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 3487 ** callback only; NULL pointers must be passed as the xStep and xFinal 3488 ** parameters. ^An aggregate SQL function requires an implementation of xStep 3489 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 3490 ** SQL function or aggregate, pass NULL pointers for all three function 3491 ** callbacks. 3492 ** 3493 ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 3494 ** then it is destructor for the application data pointer. 3495 ** The destructor is invoked when the function is deleted, either by being 3496 ** overloaded or when the database connection closes.)^ 3497 ** ^The destructor is also invoked if the call to 3498 ** sqlite3_create_function_v2() fails. 3499 ** ^When the destructor callback of the tenth parameter is invoked, it 3500 ** is passed a single argument which is a copy of the application data 3501 ** pointer which was the fifth parameter to sqlite3_create_function_v2(). 3502 ** 3503 ** ^It is permitted to register multiple implementations of the same 3504 ** functions with the same name but with either differing numbers of 3505 ** arguments or differing preferred text encodings. ^SQLite will use 3506 ** the implementation that most closely matches the way in which the 3507 ** SQL function is used. ^A function implementation with a non-negative 3508 ** nArg parameter is a better match than a function implementation with 3509 ** a negative nArg. ^A function where the preferred text encoding 3510 ** matches the database encoding is a better 3511 ** match than a function where the encoding is different. 3512 ** ^A function where the encoding difference is between UTF16le and UTF16be 3513 ** is a closer match than a function where the encoding difference is 3514 ** between UTF8 and UTF16. 3515 ** 3516 ** ^Built-in functions may be overloaded by new application-defined functions. 3517 ** 3518 ** ^An application-defined function is permitted to call other 3519 ** SQLite interfaces. However, such calls must not 3520 ** close the database connection nor finalize or reset the prepared 3521 ** statement in which the function is running. 3522 */ 3523 SQLITE_API int sqlite3_create_function( 3524 sqlite3 *db, 3525 const char *zFunctionName, 3526 int nArg, 3527 int eTextRep, 3528 void *pApp, 3529 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3530 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3531 void (*xFinal)(sqlite3_context*) 3532 ); 3533 SQLITE_API int sqlite3_create_function16( 3534 sqlite3 *db, 3535 const void *zFunctionName, 3536 int nArg, 3537 int eTextRep, 3538 void *pApp, 3539 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3540 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3541 void (*xFinal)(sqlite3_context*) 3542 ); 3543 SQLITE_API int sqlite3_create_function_v2( 3544 sqlite3 *db, 3545 const char *zFunctionName, 3546 int nArg, 3547 int eTextRep, 3548 void *pApp, 3549 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3550 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3551 void (*xFinal)(sqlite3_context*), 3552 void(*xDestroy)(void*) 3553 ); 3554 3555 /* 3556 ** CAPI3REF: Text Encodings 3557 ** 3558 ** These constant define integer codes that represent the various 3559 ** text encodings supported by SQLite. 3560 */ 3561 #define SQLITE_UTF8 1 3562 #define SQLITE_UTF16LE 2 3563 #define SQLITE_UTF16BE 3 3564 #define SQLITE_UTF16 4 /* Use native byte order */ 3565 #define SQLITE_ANY 5 /* sqlite3_create_function only */ 3566 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 3567 3568 /* 3569 ** CAPI3REF: Deprecated Functions 3570 ** DEPRECATED 3571 ** 3572 ** These functions are [deprecated]. In order to maintain 3573 ** backwards compatibility with older code, these functions continue 3574 ** to be supported. However, new applications should avoid 3575 ** the use of these functions. To help encourage people to avoid 3576 ** using these functions, we are not going to tell you what they do. 3577 */ 3578 #ifndef SQLITE_OMIT_DEPRECATED 3579 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 3580 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 3581 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 3582 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 3583 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 3584 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64); 3585 #endif 3586 3587 /* 3588 ** CAPI3REF: Obtaining SQL Function Parameter Values 3589 ** 3590 ** The C-language implementation of SQL functions and aggregates uses 3591 ** this set of interface routines to access the parameter values on 3592 ** the function or aggregate. 3593 ** 3594 ** The xFunc (for scalar functions) or xStep (for aggregates) parameters 3595 ** to [sqlite3_create_function()] and [sqlite3_create_function16()] 3596 ** define callbacks that implement the SQL functions and aggregates. 3597 ** The 3rd parameter to these callbacks is an array of pointers to 3598 ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 3599 ** each parameter to the SQL function. These routines are used to 3600 ** extract values from the [sqlite3_value] objects. 3601 ** 3602 ** These routines work only with [protected sqlite3_value] objects. 3603 ** Any attempt to use these routines on an [unprotected sqlite3_value] 3604 ** object results in undefined behavior. 3605 ** 3606 ** ^These routines work just like the corresponding [column access functions] 3607 ** except that these routines take a single [protected sqlite3_value] object 3608 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 3609 ** 3610 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 3611 ** in the native byte-order of the host machine. ^The 3612 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 3613 ** extract UTF-16 strings as big-endian and little-endian respectively. 3614 ** 3615 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 3616 ** numeric affinity to the value. This means that an attempt is 3617 ** made to convert the value to an integer or floating point. If 3618 ** such a conversion is possible without loss of information (in other 3619 ** words, if the value is a string that looks like a number) 3620 ** then the conversion is performed. Otherwise no conversion occurs. 3621 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 3622 ** 3623 ** Please pay particular attention to the fact that the pointer returned 3624 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 3625 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 3626 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 3627 ** or [sqlite3_value_text16()]. 3628 ** 3629 ** These routines must be called from the same thread as 3630 ** the SQL function that supplied the [sqlite3_value*] parameters. 3631 */ 3632 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 3633 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 3634 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 3635 SQLITE_API double sqlite3_value_double(sqlite3_value*); 3636 SQLITE_API int sqlite3_value_int(sqlite3_value*); 3637 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 3638 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 3639 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 3640 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 3641 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 3642 SQLITE_API int sqlite3_value_type(sqlite3_value*); 3643 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 3644 3645 /* 3646 ** CAPI3REF: Obtain Aggregate Function Context 3647 ** 3648 ** Implementations of aggregate SQL functions use this 3649 ** routine to allocate memory for storing their state. 3650 ** 3651 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 3652 ** for a particular aggregate function, SQLite 3653 ** allocates N of memory, zeroes out that memory, and returns a pointer 3654 ** to the new memory. ^On second and subsequent calls to 3655 ** sqlite3_aggregate_context() for the same aggregate function instance, 3656 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 3657 ** called once for each invocation of the xStep callback and then one 3658 ** last time when the xFinal callback is invoked. ^(When no rows match 3659 ** an aggregate query, the xStep() callback of the aggregate function 3660 ** implementation is never called and xFinal() is called exactly once. 3661 ** In those cases, sqlite3_aggregate_context() might be called for the 3662 ** first time from within xFinal().)^ 3663 ** 3664 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer if N is 3665 ** less than or equal to zero or if a memory allocate error occurs. 3666 ** 3667 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 3668 ** determined by the N parameter on first successful call. Changing the 3669 ** value of N in subsequent call to sqlite3_aggregate_context() within 3670 ** the same aggregate function instance will not resize the memory 3671 ** allocation.)^ 3672 ** 3673 ** ^SQLite automatically frees the memory allocated by 3674 ** sqlite3_aggregate_context() when the aggregate query concludes. 3675 ** 3676 ** The first parameter must be a copy of the 3677 ** [sqlite3_context | SQL function context] that is the first parameter 3678 ** to the xStep or xFinal callback routine that implements the aggregate 3679 ** function. 3680 ** 3681 ** This routine must be called from the same thread in which 3682 ** the aggregate SQL function is running. 3683 */ 3684 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 3685 3686 /* 3687 ** CAPI3REF: User Data For Functions 3688 ** 3689 ** ^The sqlite3_user_data() interface returns a copy of 3690 ** the pointer that was the pUserData parameter (the 5th parameter) 3691 ** of the [sqlite3_create_function()] 3692 ** and [sqlite3_create_function16()] routines that originally 3693 ** registered the application defined function. 3694 ** 3695 ** This routine must be called from the same thread in which 3696 ** the application-defined function is running. 3697 */ 3698 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 3699 3700 /* 3701 ** CAPI3REF: Database Connection For Functions 3702 ** 3703 ** ^The sqlite3_context_db_handle() interface returns a copy of 3704 ** the pointer to the [database connection] (the 1st parameter) 3705 ** of the [sqlite3_create_function()] 3706 ** and [sqlite3_create_function16()] routines that originally 3707 ** registered the application defined function. 3708 */ 3709 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 3710 3711 /* 3712 ** CAPI3REF: Function Auxiliary Data 3713 ** 3714 ** The following two functions may be used by scalar SQL functions to 3715 ** associate metadata with argument values. If the same value is passed to 3716 ** multiple invocations of the same SQL function during query execution, under 3717 ** some circumstances the associated metadata may be preserved. This may 3718 ** be used, for example, to add a regular-expression matching scalar 3719 ** function. The compiled version of the regular expression is stored as 3720 ** metadata associated with the SQL value passed as the regular expression 3721 ** pattern. The compiled regular expression can be reused on multiple 3722 ** invocations of the same function so that the original pattern string 3723 ** does not need to be recompiled on each invocation. 3724 ** 3725 ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 3726 ** associated by the sqlite3_set_auxdata() function with the Nth argument 3727 ** value to the application-defined function. ^If no metadata has been ever 3728 ** been set for the Nth argument of the function, or if the corresponding 3729 ** function parameter has changed since the meta-data was set, 3730 ** then sqlite3_get_auxdata() returns a NULL pointer. 3731 ** 3732 ** ^The sqlite3_set_auxdata() interface saves the metadata 3733 ** pointed to by its 3rd parameter as the metadata for the N-th 3734 ** argument of the application-defined function. Subsequent 3735 ** calls to sqlite3_get_auxdata() might return this data, if it has 3736 ** not been destroyed. 3737 ** ^If it is not NULL, SQLite will invoke the destructor 3738 ** function given by the 4th parameter to sqlite3_set_auxdata() on 3739 ** the metadata when the corresponding function parameter changes 3740 ** or when the SQL statement completes, whichever comes first. 3741 ** 3742 ** SQLite is free to call the destructor and drop metadata on any 3743 ** parameter of any function at any time. ^The only guarantee is that 3744 ** the destructor will be called before the metadata is dropped. 3745 ** 3746 ** ^(In practice, metadata is preserved between function calls for 3747 ** expressions that are constant at compile time. This includes literal 3748 ** values and [parameters].)^ 3749 ** 3750 ** These routines must be called from the same thread in which 3751 ** the SQL function is running. 3752 */ 3753 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 3754 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 3755 3756 3757 /* 3758 ** CAPI3REF: Constants Defining Special Destructor Behavior 3759 ** 3760 ** These are special values for the destructor that is passed in as the 3761 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 3762 ** argument is SQLITE_STATIC, it means that the content pointer is constant 3763 ** and will never change. It does not need to be destroyed. ^The 3764 ** SQLITE_TRANSIENT value means that the content will likely change in 3765 ** the near future and that SQLite should make its own private copy of 3766 ** the content before returning. 3767 ** 3768 ** The typedef is necessary to work around problems in certain 3769 ** C++ compilers. See ticket #2191. 3770 */ 3771 typedef void (*sqlite3_destructor_type)(void*); 3772 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 3773 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 3774 3775 /* 3776 ** CAPI3REF: Setting The Result Of An SQL Function 3777 ** 3778 ** These routines are used by the xFunc or xFinal callbacks that 3779 ** implement SQL functions and aggregates. See 3780 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 3781 ** for additional information. 3782 ** 3783 ** These functions work very much like the [parameter binding] family of 3784 ** functions used to bind values to host parameters in prepared statements. 3785 ** Refer to the [SQL parameter] documentation for additional information. 3786 ** 3787 ** ^The sqlite3_result_blob() interface sets the result from 3788 ** an application-defined function to be the BLOB whose content is pointed 3789 ** to by the second parameter and which is N bytes long where N is the 3790 ** third parameter. 3791 ** 3792 ** ^The sqlite3_result_zeroblob() interfaces set the result of 3793 ** the application-defined function to be a BLOB containing all zero 3794 ** bytes and N bytes in size, where N is the value of the 2nd parameter. 3795 ** 3796 ** ^The sqlite3_result_double() interface sets the result from 3797 ** an application-defined function to be a floating point value specified 3798 ** by its 2nd argument. 3799 ** 3800 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 3801 ** cause the implemented SQL function to throw an exception. 3802 ** ^SQLite uses the string pointed to by the 3803 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 3804 ** as the text of an error message. ^SQLite interprets the error 3805 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 3806 ** interprets the string from sqlite3_result_error16() as UTF-16 in native 3807 ** byte order. ^If the third parameter to sqlite3_result_error() 3808 ** or sqlite3_result_error16() is negative then SQLite takes as the error 3809 ** message all text up through the first zero character. 3810 ** ^If the third parameter to sqlite3_result_error() or 3811 ** sqlite3_result_error16() is non-negative then SQLite takes that many 3812 ** bytes (not characters) from the 2nd parameter as the error message. 3813 ** ^The sqlite3_result_error() and sqlite3_result_error16() 3814 ** routines make a private copy of the error message text before 3815 ** they return. Hence, the calling function can deallocate or 3816 ** modify the text after they return without harm. 3817 ** ^The sqlite3_result_error_code() function changes the error code 3818 ** returned by SQLite as a result of an error in a function. ^By default, 3819 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 3820 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 3821 ** 3822 ** ^The sqlite3_result_toobig() interface causes SQLite to throw an error 3823 ** indicating that a string or BLOB is too long to represent. 3824 ** 3825 ** ^The sqlite3_result_nomem() interface causes SQLite to throw an error 3826 ** indicating that a memory allocation failed. 3827 ** 3828 ** ^The sqlite3_result_int() interface sets the return value 3829 ** of the application-defined function to be the 32-bit signed integer 3830 ** value given in the 2nd argument. 3831 ** ^The sqlite3_result_int64() interface sets the return value 3832 ** of the application-defined function to be the 64-bit signed integer 3833 ** value given in the 2nd argument. 3834 ** 3835 ** ^The sqlite3_result_null() interface sets the return value 3836 ** of the application-defined function to be NULL. 3837 ** 3838 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 3839 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 3840 ** set the return value of the application-defined function to be 3841 ** a text string which is represented as UTF-8, UTF-16 native byte order, 3842 ** UTF-16 little endian, or UTF-16 big endian, respectively. 3843 ** ^SQLite takes the text result from the application from 3844 ** the 2nd parameter of the sqlite3_result_text* interfaces. 3845 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 3846 ** is negative, then SQLite takes result text from the 2nd parameter 3847 ** through the first zero character. 3848 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 3849 ** is non-negative, then as many bytes (not characters) of the text 3850 ** pointed to by the 2nd parameter are taken as the application-defined 3851 ** function result. 3852 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 3853 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 3854 ** function as the destructor on the text or BLOB result when it has 3855 ** finished using that result. 3856 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 3857 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 3858 ** assumes that the text or BLOB result is in constant space and does not 3859 ** copy the content of the parameter nor call a destructor on the content 3860 ** when it has finished using that result. 3861 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 3862 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 3863 ** then SQLite makes a copy of the result into space obtained from 3864 ** from [sqlite3_malloc()] before it returns. 3865 ** 3866 ** ^The sqlite3_result_value() interface sets the result of 3867 ** the application-defined function to be a copy the 3868 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 3869 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 3870 ** so that the [sqlite3_value] specified in the parameter may change or 3871 ** be deallocated after sqlite3_result_value() returns without harm. 3872 ** ^A [protected sqlite3_value] object may always be used where an 3873 ** [unprotected sqlite3_value] object is required, so either 3874 ** kind of [sqlite3_value] object can be used with this interface. 3875 ** 3876 ** If these routines are called from within the different thread 3877 ** than the one containing the application-defined function that received 3878 ** the [sqlite3_context] pointer, the results are undefined. 3879 */ 3880 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 3881 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 3882 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 3883 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 3884 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 3885 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 3886 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 3887 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 3888 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 3889 SQLITE_API void sqlite3_result_null(sqlite3_context*); 3890 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 3891 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 3892 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 3893 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 3894 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 3895 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 3896 3897 /* 3898 ** CAPI3REF: Define New Collating Sequences 3899 ** 3900 ** ^These functions add, remove, or modify a [collation] associated 3901 ** with the [database connection] specified as the first argument. 3902 ** 3903 ** ^The name of the collation is a UTF-8 string 3904 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 3905 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 3906 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 3907 ** considered to be the same name. 3908 ** 3909 ** ^(The third argument (eTextRep) must be one of the constants: 3910 ** <ul> 3911 ** <li> [SQLITE_UTF8], 3912 ** <li> [SQLITE_UTF16LE], 3913 ** <li> [SQLITE_UTF16BE], 3914 ** <li> [SQLITE_UTF16], or 3915 ** <li> [SQLITE_UTF16_ALIGNED]. 3916 ** </ul>)^ 3917 ** ^The eTextRep argument determines the encoding of strings passed 3918 ** to the collating function callback, xCallback. 3919 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 3920 ** force strings to be UTF16 with native byte order. 3921 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 3922 ** on an even byte address. 3923 ** 3924 ** ^The fourth argument, pArg, is an application data pointer that is passed 3925 ** through as the first argument to the collating function callback. 3926 ** 3927 ** ^The fifth argument, xCallback, is a pointer to the collating function. 3928 ** ^Multiple collating functions can be registered using the same name but 3929 ** with different eTextRep parameters and SQLite will use whichever 3930 ** function requires the least amount of data transformation. 3931 ** ^If the xCallback argument is NULL then the collating function is 3932 ** deleted. ^When all collating functions having the same name are deleted, 3933 ** that collation is no longer usable. 3934 ** 3935 ** ^The collating function callback is invoked with a copy of the pArg 3936 ** application data pointer and with two strings in the encoding specified 3937 ** by the eTextRep argument. The collating function must return an 3938 ** integer that is negative, zero, or positive 3939 ** if the first string is less than, equal to, or greater than the second, 3940 ** respectively. A collating function must always return the same answer 3941 ** given the same inputs. If two or more collating functions are registered 3942 ** to the same collation name (using different eTextRep values) then all 3943 ** must give an equivalent answer when invoked with equivalent strings. 3944 ** The collating function must obey the following properties for all 3945 ** strings A, B, and C: 3946 ** 3947 ** <ol> 3948 ** <li> If A==B then B==A. 3949 ** <li> If A==B and B==C then A==C. 3950 ** <li> If A<B THEN B>A. 3951 ** <li> If A<B and B<C then A<C. 3952 ** </ol> 3953 ** 3954 ** If a collating function fails any of the above constraints and that 3955 ** collating function is registered and used, then the behavior of SQLite 3956 ** is undefined. 3957 ** 3958 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 3959 ** with the addition that the xDestroy callback is invoked on pArg when 3960 ** the collating function is deleted. 3961 ** ^Collating functions are deleted when they are overridden by later 3962 ** calls to the collation creation functions or when the 3963 ** [database connection] is closed using [sqlite3_close()]. 3964 ** 3965 ** ^The xDestroy callback is <u>not</u> called if the 3966 ** sqlite3_create_collation_v2() function fails. Applications that invoke 3967 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 3968 ** check the return code and dispose of the application data pointer 3969 ** themselves rather than expecting SQLite to deal with it for them. 3970 ** This is different from every other SQLite interface. The inconsistency 3971 ** is unfortunate but cannot be changed without breaking backwards 3972 ** compatibility. 3973 ** 3974 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 3975 */ 3976 SQLITE_API int sqlite3_create_collation( 3977 sqlite3*, 3978 const char *zName, 3979 int eTextRep, 3980 void *pArg, 3981 int(*xCompare)(void*,int,const void*,int,const void*) 3982 ); 3983 SQLITE_API int sqlite3_create_collation_v2( 3984 sqlite3*, 3985 const char *zName, 3986 int eTextRep, 3987 void *pArg, 3988 int(*xCompare)(void*,int,const void*,int,const void*), 3989 void(*xDestroy)(void*) 3990 ); 3991 SQLITE_API int sqlite3_create_collation16( 3992 sqlite3*, 3993 const void *zName, 3994 int eTextRep, 3995 void *pArg, 3996 int(*xCompare)(void*,int,const void*,int,const void*) 3997 ); 3998 3999 /* 4000 ** CAPI3REF: Collation Needed Callbacks 4001 ** 4002 ** ^To avoid having to register all collation sequences before a database 4003 ** can be used, a single callback function may be registered with the 4004 ** [database connection] to be invoked whenever an undefined collation 4005 ** sequence is required. 4006 ** 4007 ** ^If the function is registered using the sqlite3_collation_needed() API, 4008 ** then it is passed the names of undefined collation sequences as strings 4009 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 4010 ** the names are passed as UTF-16 in machine native byte order. 4011 ** ^A call to either function replaces the existing collation-needed callback. 4012 ** 4013 ** ^(When the callback is invoked, the first argument passed is a copy 4014 ** of the second argument to sqlite3_collation_needed() or 4015 ** sqlite3_collation_needed16(). The second argument is the database 4016 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 4017 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 4018 ** sequence function required. The fourth parameter is the name of the 4019 ** required collation sequence.)^ 4020 ** 4021 ** The callback function should register the desired collation using 4022 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4023 ** [sqlite3_create_collation_v2()]. 4024 */ 4025 SQLITE_API int sqlite3_collation_needed( 4026 sqlite3*, 4027 void*, 4028 void(*)(void*,sqlite3*,int eTextRep,const char*) 4029 ); 4030 SQLITE_API int sqlite3_collation_needed16( 4031 sqlite3*, 4032 void*, 4033 void(*)(void*,sqlite3*,int eTextRep,const void*) 4034 ); 4035 4036 #ifdef SQLITE_HAS_CODEC 4037 /* 4038 ** Specify the key for an encrypted database. This routine should be 4039 ** called right after sqlite3_open(). 4040 ** 4041 ** The code to implement this API is not available in the public release 4042 ** of SQLite. 4043 */ 4044 SQLITE_API int sqlite3_key( 4045 sqlite3 *db, /* Database to be rekeyed */ 4046 const void *pKey, int nKey /* The key */ 4047 ); 4048 4049 /* 4050 ** Change the key on an open database. If the current database is not 4051 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4052 ** database is decrypted. 4053 ** 4054 ** The code to implement this API is not available in the public release 4055 ** of SQLite. 4056 */ 4057 SQLITE_API int sqlite3_rekey( 4058 sqlite3 *db, /* Database to be rekeyed */ 4059 const void *pKey, int nKey /* The new key */ 4060 ); 4061 4062 /* 4063 ** Specify the activation key for a SEE database. Unless 4064 ** activated, none of the SEE routines will work. 4065 */ 4066 SQLITE_API void sqlite3_activate_see( 4067 const char *zPassPhrase /* Activation phrase */ 4068 ); 4069 #endif 4070 4071 #ifdef SQLITE_ENABLE_CEROD 4072 /* 4073 ** Specify the activation key for a CEROD database. Unless 4074 ** activated, none of the CEROD routines will work. 4075 */ 4076 SQLITE_API void sqlite3_activate_cerod( 4077 const char *zPassPhrase /* Activation phrase */ 4078 ); 4079 #endif 4080 4081 /* 4082 ** CAPI3REF: Suspend Execution For A Short Time 4083 ** 4084 ** The sqlite3_sleep() function causes the current thread to suspend execution 4085 ** for at least a number of milliseconds specified in its parameter. 4086 ** 4087 ** If the operating system does not support sleep requests with 4088 ** millisecond time resolution, then the time will be rounded up to 4089 ** the nearest second. The number of milliseconds of sleep actually 4090 ** requested from the operating system is returned. 4091 ** 4092 ** ^SQLite implements this interface by calling the xSleep() 4093 ** method of the default [sqlite3_vfs] object. If the xSleep() method 4094 ** of the default VFS is not implemented correctly, or not implemented at 4095 ** all, then the behavior of sqlite3_sleep() may deviate from the description 4096 ** in the previous paragraphs. 4097 */ 4098 SQLITE_API int sqlite3_sleep(int); 4099 4100 /* 4101 ** CAPI3REF: Name Of The Folder Holding Temporary Files 4102 ** 4103 ** ^(If this global variable is made to point to a string which is 4104 ** the name of a folder (a.k.a. directory), then all temporary files 4105 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 4106 ** will be placed in that directory.)^ ^If this variable 4107 ** is a NULL pointer, then SQLite performs a search for an appropriate 4108 ** temporary file directory. 4109 ** 4110 ** It is not safe to read or modify this variable in more than one 4111 ** thread at a time. It is not safe to read or modify this variable 4112 ** if a [database connection] is being used at the same time in a separate 4113 ** thread. 4114 ** It is intended that this variable be set once 4115 ** as part of process initialization and before any SQLite interface 4116 ** routines have been called and that this variable remain unchanged 4117 ** thereafter. 4118 ** 4119 ** ^The [temp_store_directory pragma] may modify this variable and cause 4120 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4121 ** the [temp_store_directory pragma] always assumes that any string 4122 ** that this variable points to is held in memory obtained from 4123 ** [sqlite3_malloc] and the pragma may attempt to free that memory 4124 ** using [sqlite3_free]. 4125 ** Hence, if this variable is modified directly, either it should be 4126 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 4127 ** or else the use of the [temp_store_directory pragma] should be avoided. 4128 */ 4129 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 4130 4131 /* 4132 ** CAPI3REF: Test For Auto-Commit Mode 4133 ** KEYWORDS: {autocommit mode} 4134 ** 4135 ** ^The sqlite3_get_autocommit() interface returns non-zero or 4136 ** zero if the given database connection is or is not in autocommit mode, 4137 ** respectively. ^Autocommit mode is on by default. 4138 ** ^Autocommit mode is disabled by a [BEGIN] statement. 4139 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 4140 ** 4141 ** If certain kinds of errors occur on a statement within a multi-statement 4142 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 4143 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 4144 ** transaction might be rolled back automatically. The only way to 4145 ** find out whether SQLite automatically rolled back the transaction after 4146 ** an error is to use this function. 4147 ** 4148 ** If another thread changes the autocommit status of the database 4149 ** connection while this routine is running, then the return value 4150 ** is undefined. 4151 */ 4152 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 4153 4154 /* 4155 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 4156 ** 4157 ** ^The sqlite3_db_handle interface returns the [database connection] handle 4158 ** to which a [prepared statement] belongs. ^The [database connection] 4159 ** returned by sqlite3_db_handle is the same [database connection] 4160 ** that was the first argument 4161 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 4162 ** create the statement in the first place. 4163 */ 4164 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 4165 4166 /* 4167 ** CAPI3REF: Find the next prepared statement 4168 ** 4169 ** ^This interface returns a pointer to the next [prepared statement] after 4170 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 4171 ** then this interface returns a pointer to the first prepared statement 4172 ** associated with the database connection pDb. ^If no prepared statement 4173 ** satisfies the conditions of this routine, it returns NULL. 4174 ** 4175 ** The [database connection] pointer D in a call to 4176 ** [sqlite3_next_stmt(D,S)] must refer to an open database 4177 ** connection and in particular must not be a NULL pointer. 4178 */ 4179 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 4180 4181 /* 4182 ** CAPI3REF: Commit And Rollback Notification Callbacks 4183 ** 4184 ** ^The sqlite3_commit_hook() interface registers a callback 4185 ** function to be invoked whenever a transaction is [COMMIT | committed]. 4186 ** ^Any callback set by a previous call to sqlite3_commit_hook() 4187 ** for the same database connection is overridden. 4188 ** ^The sqlite3_rollback_hook() interface registers a callback 4189 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 4190 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 4191 ** for the same database connection is overridden. 4192 ** ^The pArg argument is passed through to the callback. 4193 ** ^If the callback on a commit hook function returns non-zero, 4194 ** then the commit is converted into a rollback. 4195 ** 4196 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 4197 ** return the P argument from the previous call of the same function 4198 ** on the same [database connection] D, or NULL for 4199 ** the first call for each function on D. 4200 ** 4201 ** The callback implementation must not do anything that will modify 4202 ** the database connection that invoked the callback. Any actions 4203 ** to modify the database connection must be deferred until after the 4204 ** completion of the [sqlite3_step()] call that triggered the commit 4205 ** or rollback hook in the first place. 4206 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 4207 ** database connections for the meaning of "modify" in this paragraph. 4208 ** 4209 ** ^Registering a NULL function disables the callback. 4210 ** 4211 ** ^When the commit hook callback routine returns zero, the [COMMIT] 4212 ** operation is allowed to continue normally. ^If the commit hook 4213 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 4214 ** ^The rollback hook is invoked on a rollback that results from a commit 4215 ** hook returning non-zero, just as it would be with any other rollback. 4216 ** 4217 ** ^For the purposes of this API, a transaction is said to have been 4218 ** rolled back if an explicit "ROLLBACK" statement is executed, or 4219 ** an error or constraint causes an implicit rollback to occur. 4220 ** ^The rollback callback is not invoked if a transaction is 4221 ** automatically rolled back because the database connection is closed. 4222 ** 4223 ** See also the [sqlite3_update_hook()] interface. 4224 */ 4225 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 4226 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 4227 4228 /* 4229 ** CAPI3REF: Data Change Notification Callbacks 4230 ** 4231 ** ^The sqlite3_update_hook() interface registers a callback function 4232 ** with the [database connection] identified by the first argument 4233 ** to be invoked whenever a row is updated, inserted or deleted. 4234 ** ^Any callback set by a previous call to this function 4235 ** for the same database connection is overridden. 4236 ** 4237 ** ^The second argument is a pointer to the function to invoke when a 4238 ** row is updated, inserted or deleted. 4239 ** ^The first argument to the callback is a copy of the third argument 4240 ** to sqlite3_update_hook(). 4241 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 4242 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 4243 ** to be invoked. 4244 ** ^The third and fourth arguments to the callback contain pointers to the 4245 ** database and table name containing the affected row. 4246 ** ^The final callback parameter is the [rowid] of the row. 4247 ** ^In the case of an update, this is the [rowid] after the update takes place. 4248 ** 4249 ** ^(The update hook is not invoked when internal system tables are 4250 ** modified (i.e. sqlite_master and sqlite_sequence).)^ 4251 ** 4252 ** ^In the current implementation, the update hook 4253 ** is not invoked when duplication rows are deleted because of an 4254 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 4255 ** invoked when rows are deleted using the [truncate optimization]. 4256 ** The exceptions defined in this paragraph might change in a future 4257 ** release of SQLite. 4258 ** 4259 ** The update hook implementation must not do anything that will modify 4260 ** the database connection that invoked the update hook. Any actions 4261 ** to modify the database connection must be deferred until after the 4262 ** completion of the [sqlite3_step()] call that triggered the update hook. 4263 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 4264 ** database connections for the meaning of "modify" in this paragraph. 4265 ** 4266 ** ^The sqlite3_update_hook(D,C,P) function 4267 ** returns the P argument from the previous call 4268 ** on the same [database connection] D, or NULL for 4269 ** the first call on D. 4270 ** 4271 ** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] 4272 ** interfaces. 4273 */ 4274 SQLITE_API void *sqlite3_update_hook( 4275 sqlite3*, 4276 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 4277 void* 4278 ); 4279 4280 /* 4281 ** CAPI3REF: Enable Or Disable Shared Pager Cache 4282 ** KEYWORDS: {shared cache} 4283 ** 4284 ** ^(This routine enables or disables the sharing of the database cache 4285 ** and schema data structures between [database connection | connections] 4286 ** to the same database. Sharing is enabled if the argument is true 4287 ** and disabled if the argument is false.)^ 4288 ** 4289 ** ^Cache sharing is enabled and disabled for an entire process. 4290 ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 4291 ** sharing was enabled or disabled for each thread separately. 4292 ** 4293 ** ^(The cache sharing mode set by this interface effects all subsequent 4294 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 4295 ** Existing database connections continue use the sharing mode 4296 ** that was in effect at the time they were opened.)^ 4297 ** 4298 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 4299 ** successfully. An [error code] is returned otherwise.)^ 4300 ** 4301 ** ^Shared cache is disabled by default. But this might change in 4302 ** future releases of SQLite. Applications that care about shared 4303 ** cache setting should set it explicitly. 4304 ** 4305 ** See Also: [SQLite Shared-Cache Mode] 4306 */ 4307 SQLITE_API int sqlite3_enable_shared_cache(int); 4308 4309 /* 4310 ** CAPI3REF: Attempt To Free Heap Memory 4311 ** 4312 ** ^The sqlite3_release_memory() interface attempts to free N bytes 4313 ** of heap memory by deallocating non-essential memory allocations 4314 ** held by the database library. Memory used to cache database 4315 ** pages to improve performance is an example of non-essential memory. 4316 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 4317 ** which might be more or less than the amount requested. 4318 ** ^The sqlite3_release_memory() routine is a no-op returning zero 4319 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 4320 */ 4321 SQLITE_API int sqlite3_release_memory(int); 4322 4323 /* 4324 ** CAPI3REF: Impose A Limit On Heap Size 4325 ** 4326 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 4327 ** soft limit on the amount of heap memory that may be allocated by SQLite. 4328 ** ^SQLite strives to keep heap memory utilization below the soft heap 4329 ** limit by reducing the number of pages held in the page cache 4330 ** as heap memory usages approaches the limit. 4331 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 4332 ** below the limit, it will exceed the limit rather than generate 4333 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 4334 ** is advisory only. 4335 ** 4336 ** ^The return value from sqlite3_soft_heap_limit64() is the size of 4337 ** the soft heap limit prior to the call. ^If the argument N is negative 4338 ** then no change is made to the soft heap limit. Hence, the current 4339 ** size of the soft heap limit can be determined by invoking 4340 ** sqlite3_soft_heap_limit64() with a negative argument. 4341 ** 4342 ** ^If the argument N is zero then the soft heap limit is disabled. 4343 ** 4344 ** ^(The soft heap limit is not enforced in the current implementation 4345 ** if one or more of following conditions are true: 4346 ** 4347 ** <ul> 4348 ** <li> The soft heap limit is set to zero. 4349 ** <li> Memory accounting is disabled using a combination of the 4350 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 4351 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 4352 ** <li> An alternative page cache implementation is specified using 4353 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE],...). 4354 ** <li> The page cache allocates from its own memory pool supplied 4355 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 4356 ** from the heap. 4357 ** </ul>)^ 4358 ** 4359 ** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 4360 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 4361 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 4362 ** the soft heap limit is enforced on every memory allocation. Without 4363 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 4364 ** when memory is allocated by the page cache. Testing suggests that because 4365 ** the page cache is the predominate memory user in SQLite, most 4366 ** applications will achieve adequate soft heap limit enforcement without 4367 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 4368 ** 4369 ** The circumstances under which SQLite will enforce the soft heap limit may 4370 ** changes in future releases of SQLite. 4371 */ 4372 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 4373 4374 /* 4375 ** CAPI3REF: Deprecated Soft Heap Limit Interface 4376 ** DEPRECATED 4377 ** 4378 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 4379 ** interface. This routine is provided for historical compatibility 4380 ** only. All new applications should use the 4381 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 4382 */ 4383 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 4384 4385 4386 /* 4387 ** CAPI3REF: Extract Metadata About A Column Of A Table 4388 ** 4389 ** ^This routine returns metadata about a specific column of a specific 4390 ** database table accessible using the [database connection] handle 4391 ** passed as the first function argument. 4392 ** 4393 ** ^The column is identified by the second, third and fourth parameters to 4394 ** this function. ^The second parameter is either the name of the database 4395 ** (i.e. "main", "temp", or an attached database) containing the specified 4396 ** table or NULL. ^If it is NULL, then all attached databases are searched 4397 ** for the table using the same algorithm used by the database engine to 4398 ** resolve unqualified table references. 4399 ** 4400 ** ^The third and fourth parameters to this function are the table and column 4401 ** name of the desired column, respectively. Neither of these parameters 4402 ** may be NULL. 4403 ** 4404 ** ^Metadata is returned by writing to the memory locations passed as the 5th 4405 ** and subsequent parameters to this function. ^Any of these arguments may be 4406 ** NULL, in which case the corresponding element of metadata is omitted. 4407 ** 4408 ** ^(<blockquote> 4409 ** <table border="1"> 4410 ** <tr><th> Parameter <th> Output<br>Type <th> Description 4411 ** 4412 ** <tr><td> 5th <td> const char* <td> Data type 4413 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 4414 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 4415 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 4416 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 4417 ** </table> 4418 ** </blockquote>)^ 4419 ** 4420 ** ^The memory pointed to by the character pointers returned for the 4421 ** declaration type and collation sequence is valid only until the next 4422 ** call to any SQLite API function. 4423 ** 4424 ** ^If the specified table is actually a view, an [error code] is returned. 4425 ** 4426 ** ^If the specified column is "rowid", "oid" or "_rowid_" and an 4427 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 4428 ** parameters are set for the explicitly declared column. ^(If there is no 4429 ** explicitly declared [INTEGER PRIMARY KEY] column, then the output 4430 ** parameters are set as follows: 4431 ** 4432 ** <pre> 4433 ** data type: "INTEGER" 4434 ** collation sequence: "BINARY" 4435 ** not null: 0 4436 ** primary key: 1 4437 ** auto increment: 0 4438 ** </pre>)^ 4439 ** 4440 ** ^(This function may load one or more schemas from database files. If an 4441 ** error occurs during this process, or if the requested table or column 4442 ** cannot be found, an [error code] is returned and an error message left 4443 ** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^ 4444 ** 4445 ** ^This API is only available if the library was compiled with the 4446 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 4447 */ 4448 SQLITE_API int sqlite3_table_column_metadata( 4449 sqlite3 *db, /* Connection handle */ 4450 const char *zDbName, /* Database name or NULL */ 4451 const char *zTableName, /* Table name */ 4452 const char *zColumnName, /* Column name */ 4453 char const **pzDataType, /* OUTPUT: Declared data type */ 4454 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 4455 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 4456 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 4457 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 4458 ); 4459 4460 /* 4461 ** CAPI3REF: Load An Extension 4462 ** 4463 ** ^This interface loads an SQLite extension library from the named file. 4464 ** 4465 ** ^The sqlite3_load_extension() interface attempts to load an 4466 ** SQLite extension library contained in the file zFile. 4467 ** 4468 ** ^The entry point is zProc. 4469 ** ^zProc may be 0, in which case the name of the entry point 4470 ** defaults to "sqlite3_extension_init". 4471 ** ^The sqlite3_load_extension() interface returns 4472 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 4473 ** ^If an error occurs and pzErrMsg is not 0, then the 4474 ** [sqlite3_load_extension()] interface shall attempt to 4475 ** fill *pzErrMsg with error message text stored in memory 4476 ** obtained from [sqlite3_malloc()]. The calling function 4477 ** should free this memory by calling [sqlite3_free()]. 4478 ** 4479 ** ^Extension loading must be enabled using 4480 ** [sqlite3_enable_load_extension()] prior to calling this API, 4481 ** otherwise an error will be returned. 4482 ** 4483 ** See also the [load_extension() SQL function]. 4484 */ 4485 SQLITE_API int sqlite3_load_extension( 4486 sqlite3 *db, /* Load the extension into this database connection */ 4487 const char *zFile, /* Name of the shared library containing extension */ 4488 const char *zProc, /* Entry point. Derived from zFile if 0 */ 4489 char **pzErrMsg /* Put error message here if not 0 */ 4490 ); 4491 4492 /* 4493 ** CAPI3REF: Enable Or Disable Extension Loading 4494 ** 4495 ** ^So as not to open security holes in older applications that are 4496 ** unprepared to deal with extension loading, and as a means of disabling 4497 ** extension loading while evaluating user-entered SQL, the following API 4498 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 4499 ** 4500 ** ^Extension loading is off by default. See ticket #1863. 4501 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 4502 ** to turn extension loading on and call it with onoff==0 to turn 4503 ** it back off again. 4504 */ 4505 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 4506 4507 /* 4508 ** CAPI3REF: Automatically Load Statically Linked Extensions 4509 ** 4510 ** ^This interface causes the xEntryPoint() function to be invoked for 4511 ** each new [database connection] that is created. The idea here is that 4512 ** xEntryPoint() is the entry point for a statically linked SQLite extension 4513 ** that is to be automatically loaded into all new database connections. 4514 ** 4515 ** ^(Even though the function prototype shows that xEntryPoint() takes 4516 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 4517 ** arguments and expects and integer result as if the signature of the 4518 ** entry point where as follows: 4519 ** 4520 ** <blockquote><pre> 4521 ** int xEntryPoint( 4522 ** sqlite3 *db, 4523 ** const char **pzErrMsg, 4524 ** const struct sqlite3_api_routines *pThunk 4525 ** ); 4526 ** </pre></blockquote>)^ 4527 ** 4528 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 4529 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 4530 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 4531 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 4532 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 4533 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 4534 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 4535 ** 4536 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 4537 ** on the list of automatic extensions is a harmless no-op. ^No entry point 4538 ** will be called more than once for each database connection that is opened. 4539 ** 4540 ** See also: [sqlite3_reset_auto_extension()]. 4541 */ 4542 SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void)); 4543 4544 /* 4545 ** CAPI3REF: Reset Automatic Extension Loading 4546 ** 4547 ** ^This interface disables all automatic extensions previously 4548 ** registered using [sqlite3_auto_extension()]. 4549 */ 4550 SQLITE_API void sqlite3_reset_auto_extension(void); 4551 4552 /* 4553 ** The interface to the virtual-table mechanism is currently considered 4554 ** to be experimental. The interface might change in incompatible ways. 4555 ** If this is a problem for you, do not use the interface at this time. 4556 ** 4557 ** When the virtual-table mechanism stabilizes, we will declare the 4558 ** interface fixed, support it indefinitely, and remove this comment. 4559 */ 4560 4561 /* 4562 ** Structures used by the virtual table interface 4563 */ 4564 typedef struct sqlite3_vtab sqlite3_vtab; 4565 typedef struct sqlite3_index_info sqlite3_index_info; 4566 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 4567 typedef struct sqlite3_module sqlite3_module; 4568 4569 /* 4570 ** CAPI3REF: Virtual Table Object 4571 ** KEYWORDS: sqlite3_module {virtual table module} 4572 ** 4573 ** This structure, sometimes called a "virtual table module", 4574 ** defines the implementation of a [virtual tables]. 4575 ** This structure consists mostly of methods for the module. 4576 ** 4577 ** ^A virtual table module is created by filling in a persistent 4578 ** instance of this structure and passing a pointer to that instance 4579 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 4580 ** ^The registration remains valid until it is replaced by a different 4581 ** module or until the [database connection] closes. The content 4582 ** of this structure must not change while it is registered with 4583 ** any database connection. 4584 */ 4585 struct sqlite3_module { 4586 int iVersion; 4587 int (*xCreate)(sqlite3*, void *pAux, 4588 int argc, const char *const*argv, 4589 sqlite3_vtab **ppVTab, char**); 4590 int (*xConnect)(sqlite3*, void *pAux, 4591 int argc, const char *const*argv, 4592 sqlite3_vtab **ppVTab, char**); 4593 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 4594 int (*xDisconnect)(sqlite3_vtab *pVTab); 4595 int (*xDestroy)(sqlite3_vtab *pVTab); 4596 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 4597 int (*xClose)(sqlite3_vtab_cursor*); 4598 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 4599 int argc, sqlite3_value **argv); 4600 int (*xNext)(sqlite3_vtab_cursor*); 4601 int (*xEof)(sqlite3_vtab_cursor*); 4602 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 4603 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 4604 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 4605 int (*xBegin)(sqlite3_vtab *pVTab); 4606 int (*xSync)(sqlite3_vtab *pVTab); 4607 int (*xCommit)(sqlite3_vtab *pVTab); 4608 int (*xRollback)(sqlite3_vtab *pVTab); 4609 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 4610 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 4611 void **ppArg); 4612 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 4613 }; 4614 4615 /* 4616 ** CAPI3REF: Virtual Table Indexing Information 4617 ** KEYWORDS: sqlite3_index_info 4618 ** 4619 ** The sqlite3_index_info structure and its substructures is used as part 4620 ** of the [virtual table] interface to 4621 ** pass information into and receive the reply from the [xBestIndex] 4622 ** method of a [virtual table module]. The fields under **Inputs** are the 4623 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 4624 ** results into the **Outputs** fields. 4625 ** 4626 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 4627 ** 4628 ** <blockquote>column OP expr</blockquote> 4629 ** 4630 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 4631 ** stored in aConstraint[].op using one of the 4632 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 4633 ** ^(The index of the column is stored in 4634 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 4635 ** expr on the right-hand side can be evaluated (and thus the constraint 4636 ** is usable) and false if it cannot.)^ 4637 ** 4638 ** ^The optimizer automatically inverts terms of the form "expr OP column" 4639 ** and makes other simplifications to the WHERE clause in an attempt to 4640 ** get as many WHERE clause terms into the form shown above as possible. 4641 ** ^The aConstraint[] array only reports WHERE clause terms that are 4642 ** relevant to the particular virtual table being queried. 4643 ** 4644 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 4645 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 4646 ** 4647 ** The [xBestIndex] method must fill aConstraintUsage[] with information 4648 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 4649 ** the right-hand side of the corresponding aConstraint[] is evaluated 4650 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 4651 ** is true, then the constraint is assumed to be fully handled by the 4652 ** virtual table and is not checked again by SQLite.)^ 4653 ** 4654 ** ^The idxNum and idxPtr values are recorded and passed into the 4655 ** [xFilter] method. 4656 ** ^[sqlite3_free()] is used to free idxPtr if and only if 4657 ** needToFreeIdxPtr is true. 4658 ** 4659 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 4660 ** the correct order to satisfy the ORDER BY clause so that no separate 4661 ** sorting step is required. 4662 ** 4663 ** ^The estimatedCost value is an estimate of the cost of doing the 4664 ** particular lookup. A full scan of a table with N entries should have 4665 ** a cost of N. A binary search of a table of N entries should have a 4666 ** cost of approximately log(N). 4667 */ 4668 struct sqlite3_index_info { 4669 /* Inputs */ 4670 int nConstraint; /* Number of entries in aConstraint */ 4671 struct sqlite3_index_constraint { 4672 int iColumn; /* Column on left-hand side of constraint */ 4673 unsigned char op; /* Constraint operator */ 4674 unsigned char usable; /* True if this constraint is usable */ 4675 int iTermOffset; /* Used internally - xBestIndex should ignore */ 4676 } *aConstraint; /* Table of WHERE clause constraints */ 4677 int nOrderBy; /* Number of terms in the ORDER BY clause */ 4678 struct sqlite3_index_orderby { 4679 int iColumn; /* Column number */ 4680 unsigned char desc; /* True for DESC. False for ASC. */ 4681 } *aOrderBy; /* The ORDER BY clause */ 4682 /* Outputs */ 4683 struct sqlite3_index_constraint_usage { 4684 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 4685 unsigned char omit; /* Do not code a test for this constraint */ 4686 } *aConstraintUsage; 4687 int idxNum; /* Number used to identify the index */ 4688 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 4689 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 4690 int orderByConsumed; /* True if output is already ordered */ 4691 double estimatedCost; /* Estimated cost of using this index */ 4692 }; 4693 4694 /* 4695 ** CAPI3REF: Virtual Table Constraint Operator Codes 4696 ** 4697 ** These macros defined the allowed values for the 4698 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 4699 ** an operator that is part of a constraint term in the wHERE clause of 4700 ** a query that uses a [virtual table]. 4701 */ 4702 #define SQLITE_INDEX_CONSTRAINT_EQ 2 4703 #define SQLITE_INDEX_CONSTRAINT_GT 4 4704 #define SQLITE_INDEX_CONSTRAINT_LE 8 4705 #define SQLITE_INDEX_CONSTRAINT_LT 16 4706 #define SQLITE_INDEX_CONSTRAINT_GE 32 4707 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 4708 4709 /* 4710 ** CAPI3REF: Register A Virtual Table Implementation 4711 ** 4712 ** ^These routines are used to register a new [virtual table module] name. 4713 ** ^Module names must be registered before 4714 ** creating a new [virtual table] using the module and before using a 4715 ** preexisting [virtual table] for the module. 4716 ** 4717 ** ^The module name is registered on the [database connection] specified 4718 ** by the first parameter. ^The name of the module is given by the 4719 ** second parameter. ^The third parameter is a pointer to 4720 ** the implementation of the [virtual table module]. ^The fourth 4721 ** parameter is an arbitrary client data pointer that is passed through 4722 ** into the [xCreate] and [xConnect] methods of the virtual table module 4723 ** when a new virtual table is be being created or reinitialized. 4724 ** 4725 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 4726 ** is a pointer to a destructor for the pClientData. ^SQLite will 4727 ** invoke the destructor function (if it is not NULL) when SQLite 4728 ** no longer needs the pClientData pointer. ^The destructor will also 4729 ** be invoked if the call to sqlite3_create_module_v2() fails. 4730 ** ^The sqlite3_create_module() 4731 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 4732 ** destructor. 4733 */ 4734 SQLITE_API int sqlite3_create_module( 4735 sqlite3 *db, /* SQLite connection to register module with */ 4736 const char *zName, /* Name of the module */ 4737 const sqlite3_module *p, /* Methods for the module */ 4738 void *pClientData /* Client data for xCreate/xConnect */ 4739 ); 4740 SQLITE_API int sqlite3_create_module_v2( 4741 sqlite3 *db, /* SQLite connection to register module with */ 4742 const char *zName, /* Name of the module */ 4743 const sqlite3_module *p, /* Methods for the module */ 4744 void *pClientData, /* Client data for xCreate/xConnect */ 4745 void(*xDestroy)(void*) /* Module destructor function */ 4746 ); 4747 4748 /* 4749 ** CAPI3REF: Virtual Table Instance Object 4750 ** KEYWORDS: sqlite3_vtab 4751 ** 4752 ** Every [virtual table module] implementation uses a subclass 4753 ** of this object to describe a particular instance 4754 ** of the [virtual table]. Each subclass will 4755 ** be tailored to the specific needs of the module implementation. 4756 ** The purpose of this superclass is to define certain fields that are 4757 ** common to all module implementations. 4758 ** 4759 ** ^Virtual tables methods can set an error message by assigning a 4760 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 4761 ** take care that any prior string is freed by a call to [sqlite3_free()] 4762 ** prior to assigning a new string to zErrMsg. ^After the error message 4763 ** is delivered up to the client application, the string will be automatically 4764 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 4765 */ 4766 struct sqlite3_vtab { 4767 const sqlite3_module *pModule; /* The module for this virtual table */ 4768 int nRef; /* NO LONGER USED */ 4769 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 4770 /* Virtual table implementations will typically add additional fields */ 4771 }; 4772 4773 /* 4774 ** CAPI3REF: Virtual Table Cursor Object 4775 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 4776 ** 4777 ** Every [virtual table module] implementation uses a subclass of the 4778 ** following structure to describe cursors that point into the 4779 ** [virtual table] and are used 4780 ** to loop through the virtual table. Cursors are created using the 4781 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 4782 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 4783 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 4784 ** of the module. Each module implementation will define 4785 ** the content of a cursor structure to suit its own needs. 4786 ** 4787 ** This superclass exists in order to define fields of the cursor that 4788 ** are common to all implementations. 4789 */ 4790 struct sqlite3_vtab_cursor { 4791 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 4792 /* Virtual table implementations will typically add additional fields */ 4793 }; 4794 4795 /* 4796 ** CAPI3REF: Declare The Schema Of A Virtual Table 4797 ** 4798 ** ^The [xCreate] and [xConnect] methods of a 4799 ** [virtual table module] call this interface 4800 ** to declare the format (the names and datatypes of the columns) of 4801 ** the virtual tables they implement. 4802 */ 4803 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 4804 4805 /* 4806 ** CAPI3REF: Overload A Function For A Virtual Table 4807 ** 4808 ** ^(Virtual tables can provide alternative implementations of functions 4809 ** using the [xFindFunction] method of the [virtual table module]. 4810 ** But global versions of those functions 4811 ** must exist in order to be overloaded.)^ 4812 ** 4813 ** ^(This API makes sure a global version of a function with a particular 4814 ** name and number of parameters exists. If no such function exists 4815 ** before this API is called, a new function is created.)^ ^The implementation 4816 ** of the new function always causes an exception to be thrown. So 4817 ** the new function is not good for anything by itself. Its only 4818 ** purpose is to be a placeholder function that can be overloaded 4819 ** by a [virtual table]. 4820 */ 4821 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 4822 4823 /* 4824 ** The interface to the virtual-table mechanism defined above (back up 4825 ** to a comment remarkably similar to this one) is currently considered 4826 ** to be experimental. The interface might change in incompatible ways. 4827 ** If this is a problem for you, do not use the interface at this time. 4828 ** 4829 ** When the virtual-table mechanism stabilizes, we will declare the 4830 ** interface fixed, support it indefinitely, and remove this comment. 4831 */ 4832 4833 /* 4834 ** CAPI3REF: A Handle To An Open BLOB 4835 ** KEYWORDS: {BLOB handle} {BLOB handles} 4836 ** 4837 ** An instance of this object represents an open BLOB on which 4838 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 4839 ** ^Objects of this type are created by [sqlite3_blob_open()] 4840 ** and destroyed by [sqlite3_blob_close()]. 4841 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 4842 ** can be used to read or write small subsections of the BLOB. 4843 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 4844 */ 4845 typedef struct sqlite3_blob sqlite3_blob; 4846 4847 /* 4848 ** CAPI3REF: Open A BLOB For Incremental I/O 4849 ** 4850 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 4851 ** in row iRow, column zColumn, table zTable in database zDb; 4852 ** in other words, the same BLOB that would be selected by: 4853 ** 4854 ** <pre> 4855 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 4856 ** </pre>)^ 4857 ** 4858 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 4859 ** and write access. ^If it is zero, the BLOB is opened for read access. 4860 ** ^It is not possible to open a column that is part of an index or primary 4861 ** key for writing. ^If [foreign key constraints] are enabled, it is 4862 ** not possible to open a column that is part of a [child key] for writing. 4863 ** 4864 ** ^Note that the database name is not the filename that contains 4865 ** the database but rather the symbolic name of the database that 4866 ** appears after the AS keyword when the database is connected using [ATTACH]. 4867 ** ^For the main database file, the database name is "main". 4868 ** ^For TEMP tables, the database name is "temp". 4869 ** 4870 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written 4871 ** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set 4872 ** to be a null pointer.)^ 4873 ** ^This function sets the [database connection] error code and message 4874 ** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related 4875 ** functions. ^Note that the *ppBlob variable is always initialized in a 4876 ** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob 4877 ** regardless of the success or failure of this routine. 4878 ** 4879 ** ^(If the row that a BLOB handle points to is modified by an 4880 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 4881 ** then the BLOB handle is marked as "expired". 4882 ** This is true if any column of the row is changed, even a column 4883 ** other than the one the BLOB handle is open on.)^ 4884 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 4885 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 4886 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 4887 ** rolled back by the expiration of the BLOB. Such changes will eventually 4888 ** commit if the transaction continues to completion.)^ 4889 ** 4890 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 4891 ** the opened blob. ^The size of a blob may not be changed by this 4892 ** interface. Use the [UPDATE] SQL command to change the size of a 4893 ** blob. 4894 ** 4895 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 4896 ** and the built-in [zeroblob] SQL function can be used, if desired, 4897 ** to create an empty, zero-filled blob in which to read or write using 4898 ** this interface. 4899 ** 4900 ** To avoid a resource leak, every open [BLOB handle] should eventually 4901 ** be released by a call to [sqlite3_blob_close()]. 4902 */ 4903 SQLITE_API int sqlite3_blob_open( 4904 sqlite3*, 4905 const char *zDb, 4906 const char *zTable, 4907 const char *zColumn, 4908 sqlite3_int64 iRow, 4909 int flags, 4910 sqlite3_blob **ppBlob 4911 ); 4912 4913 /* 4914 ** CAPI3REF: Move a BLOB Handle to a New Row 4915 ** 4916 ** ^This function is used to move an existing blob handle so that it points 4917 ** to a different row of the same database table. ^The new row is identified 4918 ** by the rowid value passed as the second argument. Only the row can be 4919 ** changed. ^The database, table and column on which the blob handle is open 4920 ** remain the same. Moving an existing blob handle to a new row can be 4921 ** faster than closing the existing handle and opening a new one. 4922 ** 4923 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 4924 ** it must exist and there must be either a blob or text value stored in 4925 ** the nominated column.)^ ^If the new row is not present in the table, or if 4926 ** it does not contain a blob or text value, or if another error occurs, an 4927 ** SQLite error code is returned and the blob handle is considered aborted. 4928 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 4929 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 4930 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 4931 ** always returns zero. 4932 ** 4933 ** ^This function sets the database handle error code and message. 4934 */ 4935 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 4936 4937 /* 4938 ** CAPI3REF: Close A BLOB Handle 4939 ** 4940 ** ^Closes an open [BLOB handle]. 4941 ** 4942 ** ^Closing a BLOB shall cause the current transaction to commit 4943 ** if there are no other BLOBs, no pending prepared statements, and the 4944 ** database connection is in [autocommit mode]. 4945 ** ^If any writes were made to the BLOB, they might be held in cache 4946 ** until the close operation if they will fit. 4947 ** 4948 ** ^(Closing the BLOB often forces the changes 4949 ** out to disk and so if any I/O errors occur, they will likely occur 4950 ** at the time when the BLOB is closed. Any errors that occur during 4951 ** closing are reported as a non-zero return value.)^ 4952 ** 4953 ** ^(The BLOB is closed unconditionally. Even if this routine returns 4954 ** an error code, the BLOB is still closed.)^ 4955 ** 4956 ** ^Calling this routine with a null pointer (such as would be returned 4957 ** by a failed call to [sqlite3_blob_open()]) is a harmless no-op. 4958 */ 4959 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 4960 4961 /* 4962 ** CAPI3REF: Return The Size Of An Open BLOB 4963 ** 4964 ** ^Returns the size in bytes of the BLOB accessible via the 4965 ** successfully opened [BLOB handle] in its only argument. ^The 4966 ** incremental blob I/O routines can only read or overwriting existing 4967 ** blob content; they cannot change the size of a blob. 4968 ** 4969 ** This routine only works on a [BLOB handle] which has been created 4970 ** by a prior successful call to [sqlite3_blob_open()] and which has not 4971 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 4972 ** to this routine results in undefined and probably undesirable behavior. 4973 */ 4974 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 4975 4976 /* 4977 ** CAPI3REF: Read Data From A BLOB Incrementally 4978 ** 4979 ** ^(This function is used to read data from an open [BLOB handle] into a 4980 ** caller-supplied buffer. N bytes of data are copied into buffer Z 4981 ** from the open BLOB, starting at offset iOffset.)^ 4982 ** 4983 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 4984 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 4985 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 4986 ** ^The size of the blob (and hence the maximum value of N+iOffset) 4987 ** can be determined using the [sqlite3_blob_bytes()] interface. 4988 ** 4989 ** ^An attempt to read from an expired [BLOB handle] fails with an 4990 ** error code of [SQLITE_ABORT]. 4991 ** 4992 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 4993 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 4994 ** 4995 ** This routine only works on a [BLOB handle] which has been created 4996 ** by a prior successful call to [sqlite3_blob_open()] and which has not 4997 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 4998 ** to this routine results in undefined and probably undesirable behavior. 4999 ** 5000 ** See also: [sqlite3_blob_write()]. 5001 */ 5002 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 5003 5004 /* 5005 ** CAPI3REF: Write Data Into A BLOB Incrementally 5006 ** 5007 ** ^This function is used to write data into an open [BLOB handle] from a 5008 ** caller-supplied buffer. ^N bytes of data are copied from the buffer Z 5009 ** into the open BLOB, starting at offset iOffset. 5010 ** 5011 ** ^If the [BLOB handle] passed as the first argument was not opened for 5012 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 5013 ** this function returns [SQLITE_READONLY]. 5014 ** 5015 ** ^This function may only modify the contents of the BLOB; it is 5016 ** not possible to increase the size of a BLOB using this API. 5017 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 5018 ** [SQLITE_ERROR] is returned and no data is written. ^If N is 5019 ** less than zero [SQLITE_ERROR] is returned and no data is written. 5020 ** The size of the BLOB (and hence the maximum value of N+iOffset) 5021 ** can be determined using the [sqlite3_blob_bytes()] interface. 5022 ** 5023 ** ^An attempt to write to an expired [BLOB handle] fails with an 5024 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 5025 ** before the [BLOB handle] expired are not rolled back by the 5026 ** expiration of the handle, though of course those changes might 5027 ** have been overwritten by the statement that expired the BLOB handle 5028 ** or by other independent statements. 5029 ** 5030 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 5031 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 5032 ** 5033 ** This routine only works on a [BLOB handle] which has been created 5034 ** by a prior successful call to [sqlite3_blob_open()] and which has not 5035 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5036 ** to this routine results in undefined and probably undesirable behavior. 5037 ** 5038 ** See also: [sqlite3_blob_read()]. 5039 */ 5040 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 5041 5042 /* 5043 ** CAPI3REF: Virtual File System Objects 5044 ** 5045 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 5046 ** that SQLite uses to interact 5047 ** with the underlying operating system. Most SQLite builds come with a 5048 ** single default VFS that is appropriate for the host computer. 5049 ** New VFSes can be registered and existing VFSes can be unregistered. 5050 ** The following interfaces are provided. 5051 ** 5052 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 5053 ** ^Names are case sensitive. 5054 ** ^Names are zero-terminated UTF-8 strings. 5055 ** ^If there is no match, a NULL pointer is returned. 5056 ** ^If zVfsName is NULL then the default VFS is returned. 5057 ** 5058 ** ^New VFSes are registered with sqlite3_vfs_register(). 5059 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 5060 ** ^The same VFS can be registered multiple times without injury. 5061 ** ^To make an existing VFS into the default VFS, register it again 5062 ** with the makeDflt flag set. If two different VFSes with the 5063 ** same name are registered, the behavior is undefined. If a 5064 ** VFS is registered with a name that is NULL or an empty string, 5065 ** then the behavior is undefined. 5066 ** 5067 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 5068 ** ^(If the default VFS is unregistered, another VFS is chosen as 5069 ** the default. The choice for the new VFS is arbitrary.)^ 5070 */ 5071 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 5072 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 5073 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 5074 5075 /* 5076 ** CAPI3REF: Mutexes 5077 ** 5078 ** The SQLite core uses these routines for thread 5079 ** synchronization. Though they are intended for internal 5080 ** use by SQLite, code that links against SQLite is 5081 ** permitted to use any of these routines. 5082 ** 5083 ** The SQLite source code contains multiple implementations 5084 ** of these mutex routines. An appropriate implementation 5085 ** is selected automatically at compile-time. ^(The following 5086 ** implementations are available in the SQLite core: 5087 ** 5088 ** <ul> 5089 ** <li> SQLITE_MUTEX_OS2 5090 ** <li> SQLITE_MUTEX_PTHREAD 5091 ** <li> SQLITE_MUTEX_W32 5092 ** <li> SQLITE_MUTEX_NOOP 5093 ** </ul>)^ 5094 ** 5095 ** ^The SQLITE_MUTEX_NOOP implementation is a set of routines 5096 ** that does no real locking and is appropriate for use in 5097 ** a single-threaded application. ^The SQLITE_MUTEX_OS2, 5098 ** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations 5099 ** are appropriate for use on OS/2, Unix, and Windows. 5100 ** 5101 ** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 5102 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 5103 ** implementation is included with the library. In this case the 5104 ** application must supply a custom mutex implementation using the 5105 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 5106 ** before calling sqlite3_initialize() or any other public sqlite3_ 5107 ** function that calls sqlite3_initialize().)^ 5108 ** 5109 ** ^The sqlite3_mutex_alloc() routine allocates a new 5110 ** mutex and returns a pointer to it. ^If it returns NULL 5111 ** that means that a mutex could not be allocated. ^SQLite 5112 ** will unwind its stack and return an error. ^(The argument 5113 ** to sqlite3_mutex_alloc() is one of these integer constants: 5114 ** 5115 ** <ul> 5116 ** <li> SQLITE_MUTEX_FAST 5117 ** <li> SQLITE_MUTEX_RECURSIVE 5118 ** <li> SQLITE_MUTEX_STATIC_MASTER 5119 ** <li> SQLITE_MUTEX_STATIC_MEM 5120 ** <li> SQLITE_MUTEX_STATIC_MEM2 5121 ** <li> SQLITE_MUTEX_STATIC_PRNG 5122 ** <li> SQLITE_MUTEX_STATIC_LRU 5123 ** <li> SQLITE_MUTEX_STATIC_LRU2 5124 ** </ul>)^ 5125 ** 5126 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 5127 ** cause sqlite3_mutex_alloc() to create 5128 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 5129 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 5130 ** The mutex implementation does not need to make a distinction 5131 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 5132 ** not want to. ^SQLite will only request a recursive mutex in 5133 ** cases where it really needs one. ^If a faster non-recursive mutex 5134 ** implementation is available on the host platform, the mutex subsystem 5135 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 5136 ** 5137 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 5138 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 5139 ** a pointer to a static preexisting mutex. ^Six static mutexes are 5140 ** used by the current version of SQLite. Future versions of SQLite 5141 ** may add additional static mutexes. Static mutexes are for internal 5142 ** use by SQLite only. Applications that use SQLite mutexes should 5143 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 5144 ** SQLITE_MUTEX_RECURSIVE. 5145 ** 5146 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 5147 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 5148 ** returns a different mutex on every call. ^But for the static 5149 ** mutex types, the same mutex is returned on every call that has 5150 ** the same type number. 5151 ** 5152 ** ^The sqlite3_mutex_free() routine deallocates a previously 5153 ** allocated dynamic mutex. ^SQLite is careful to deallocate every 5154 ** dynamic mutex that it allocates. The dynamic mutexes must not be in 5155 ** use when they are deallocated. Attempting to deallocate a static 5156 ** mutex results in undefined behavior. ^SQLite never deallocates 5157 ** a static mutex. 5158 ** 5159 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 5160 ** to enter a mutex. ^If another thread is already within the mutex, 5161 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 5162 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 5163 ** upon successful entry. ^(Mutexes created using 5164 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 5165 ** In such cases the, 5166 ** mutex must be exited an equal number of times before another thread 5167 ** can enter.)^ ^(If the same thread tries to enter any other 5168 ** kind of mutex more than once, the behavior is undefined. 5169 ** SQLite will never exhibit 5170 ** such behavior in its own use of mutexes.)^ 5171 ** 5172 ** ^(Some systems (for example, Windows 95) do not support the operation 5173 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 5174 ** will always return SQLITE_BUSY. The SQLite core only ever uses 5175 ** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^ 5176 ** 5177 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 5178 ** previously entered by the same thread. ^(The behavior 5179 ** is undefined if the mutex is not currently entered by the 5180 ** calling thread or is not currently allocated. SQLite will 5181 ** never do either.)^ 5182 ** 5183 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 5184 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 5185 ** behave as no-ops. 5186 ** 5187 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 5188 */ 5189 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 5190 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 5191 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 5192 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 5193 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 5194 5195 /* 5196 ** CAPI3REF: Mutex Methods Object 5197 ** 5198 ** An instance of this structure defines the low-level routines 5199 ** used to allocate and use mutexes. 5200 ** 5201 ** Usually, the default mutex implementations provided by SQLite are 5202 ** sufficient, however the user has the option of substituting a custom 5203 ** implementation for specialized deployments or systems for which SQLite 5204 ** does not provide a suitable implementation. In this case, the user 5205 ** creates and populates an instance of this structure to pass 5206 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 5207 ** Additionally, an instance of this structure can be used as an 5208 ** output variable when querying the system for the current mutex 5209 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 5210 ** 5211 ** ^The xMutexInit method defined by this structure is invoked as 5212 ** part of system initialization by the sqlite3_initialize() function. 5213 ** ^The xMutexInit routine is called by SQLite exactly once for each 5214 ** effective call to [sqlite3_initialize()]. 5215 ** 5216 ** ^The xMutexEnd method defined by this structure is invoked as 5217 ** part of system shutdown by the sqlite3_shutdown() function. The 5218 ** implementation of this method is expected to release all outstanding 5219 ** resources obtained by the mutex methods implementation, especially 5220 ** those obtained by the xMutexInit method. ^The xMutexEnd() 5221 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 5222 ** 5223 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 5224 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 5225 ** xMutexNotheld) implement the following interfaces (respectively): 5226 ** 5227 ** <ul> 5228 ** <li> [sqlite3_mutex_alloc()] </li> 5229 ** <li> [sqlite3_mutex_free()] </li> 5230 ** <li> [sqlite3_mutex_enter()] </li> 5231 ** <li> [sqlite3_mutex_try()] </li> 5232 ** <li> [sqlite3_mutex_leave()] </li> 5233 ** <li> [sqlite3_mutex_held()] </li> 5234 ** <li> [sqlite3_mutex_notheld()] </li> 5235 ** </ul>)^ 5236 ** 5237 ** The only difference is that the public sqlite3_XXX functions enumerated 5238 ** above silently ignore any invocations that pass a NULL pointer instead 5239 ** of a valid mutex handle. The implementations of the methods defined 5240 ** by this structure are not required to handle this case, the results 5241 ** of passing a NULL pointer instead of a valid mutex handle are undefined 5242 ** (i.e. it is acceptable to provide an implementation that segfaults if 5243 ** it is passed a NULL pointer). 5244 ** 5245 ** The xMutexInit() method must be threadsafe. ^It must be harmless to 5246 ** invoke xMutexInit() multiple times within the same process and without 5247 ** intervening calls to xMutexEnd(). Second and subsequent calls to 5248 ** xMutexInit() must be no-ops. 5249 ** 5250 ** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 5251 ** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory 5252 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 5253 ** memory allocation for a fast or recursive mutex. 5254 ** 5255 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 5256 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 5257 ** If xMutexInit fails in any way, it is expected to clean up after itself 5258 ** prior to returning. 5259 */ 5260 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 5261 struct sqlite3_mutex_methods { 5262 int (*xMutexInit)(void); 5263 int (*xMutexEnd)(void); 5264 sqlite3_mutex *(*xMutexAlloc)(int); 5265 void (*xMutexFree)(sqlite3_mutex *); 5266 void (*xMutexEnter)(sqlite3_mutex *); 5267 int (*xMutexTry)(sqlite3_mutex *); 5268 void (*xMutexLeave)(sqlite3_mutex *); 5269 int (*xMutexHeld)(sqlite3_mutex *); 5270 int (*xMutexNotheld)(sqlite3_mutex *); 5271 }; 5272 5273 /* 5274 ** CAPI3REF: Mutex Verification Routines 5275 ** 5276 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 5277 ** are intended for use inside assert() statements. ^The SQLite core 5278 ** never uses these routines except inside an assert() and applications 5279 ** are advised to follow the lead of the core. ^The SQLite core only 5280 ** provides implementations for these routines when it is compiled 5281 ** with the SQLITE_DEBUG flag. ^External mutex implementations 5282 ** are only required to provide these routines if SQLITE_DEBUG is 5283 ** defined and if NDEBUG is not defined. 5284 ** 5285 ** ^These routines should return true if the mutex in their argument 5286 ** is held or not held, respectively, by the calling thread. 5287 ** 5288 ** ^The implementation is not required to provided versions of these 5289 ** routines that actually work. If the implementation does not provide working 5290 ** versions of these routines, it should at least provide stubs that always 5291 ** return true so that one does not get spurious assertion failures. 5292 ** 5293 ** ^If the argument to sqlite3_mutex_held() is a NULL pointer then 5294 ** the routine should return 1. This seems counter-intuitive since 5295 ** clearly the mutex cannot be held if it does not exist. But the 5296 ** the reason the mutex does not exist is because the build is not 5297 ** using mutexes. And we do not want the assert() containing the 5298 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 5299 ** the appropriate thing to do. ^The sqlite3_mutex_notheld() 5300 ** interface should also return 1 when given a NULL pointer. 5301 */ 5302 #ifndef NDEBUG 5303 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 5304 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 5305 #endif 5306 5307 /* 5308 ** CAPI3REF: Mutex Types 5309 ** 5310 ** The [sqlite3_mutex_alloc()] interface takes a single argument 5311 ** which is one of these integer constants. 5312 ** 5313 ** The set of static mutexes may change from one SQLite release to the 5314 ** next. Applications that override the built-in mutex logic must be 5315 ** prepared to accommodate additional static mutexes. 5316 */ 5317 #define SQLITE_MUTEX_FAST 0 5318 #define SQLITE_MUTEX_RECURSIVE 1 5319 #define SQLITE_MUTEX_STATIC_MASTER 2 5320 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 5321 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 5322 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 5323 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 5324 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 5325 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 5326 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 5327 5328 /* 5329 ** CAPI3REF: Retrieve the mutex for a database connection 5330 ** 5331 ** ^This interface returns a pointer the [sqlite3_mutex] object that 5332 ** serializes access to the [database connection] given in the argument 5333 ** when the [threading mode] is Serialized. 5334 ** ^If the [threading mode] is Single-thread or Multi-thread then this 5335 ** routine returns a NULL pointer. 5336 */ 5337 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 5338 5339 /* 5340 ** CAPI3REF: Low-Level Control Of Database Files 5341 ** 5342 ** ^The [sqlite3_file_control()] interface makes a direct call to the 5343 ** xFileControl method for the [sqlite3_io_methods] object associated 5344 ** with a particular database identified by the second argument. ^The 5345 ** name of the database is "main" for the main database or "temp" for the 5346 ** TEMP database, or the name that appears after the AS keyword for 5347 ** databases that are added using the [ATTACH] SQL command. 5348 ** ^A NULL pointer can be used in place of "main" to refer to the 5349 ** main database file. 5350 ** ^The third and fourth parameters to this routine 5351 ** are passed directly through to the second and third parameters of 5352 ** the xFileControl method. ^The return value of the xFileControl 5353 ** method becomes the return value of this routine. 5354 ** 5355 ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 5356 ** a pointer to the underlying [sqlite3_file] object to be written into 5357 ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 5358 ** case is a short-circuit path which does not actually invoke the 5359 ** underlying sqlite3_io_methods.xFileControl method. 5360 ** 5361 ** ^If the second parameter (zDbName) does not match the name of any 5362 ** open database file, then SQLITE_ERROR is returned. ^This error 5363 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 5364 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 5365 ** also return SQLITE_ERROR. There is no way to distinguish between 5366 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 5367 ** xFileControl method. 5368 ** 5369 ** See also: [SQLITE_FCNTL_LOCKSTATE] 5370 */ 5371 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 5372 5373 /* 5374 ** CAPI3REF: Testing Interface 5375 ** 5376 ** ^The sqlite3_test_control() interface is used to read out internal 5377 ** state of SQLite and to inject faults into SQLite for testing 5378 ** purposes. ^The first parameter is an operation code that determines 5379 ** the number, meaning, and operation of all subsequent parameters. 5380 ** 5381 ** This interface is not for use by applications. It exists solely 5382 ** for verifying the correct operation of the SQLite library. Depending 5383 ** on how the SQLite library is compiled, this interface might not exist. 5384 ** 5385 ** The details of the operation codes, their meanings, the parameters 5386 ** they take, and what they do are all subject to change without notice. 5387 ** Unlike most of the SQLite API, this function is not guaranteed to 5388 ** operate consistently from one release to the next. 5389 */ 5390 SQLITE_API int sqlite3_test_control(int op, ...); 5391 5392 /* 5393 ** CAPI3REF: Testing Interface Operation Codes 5394 ** 5395 ** These constants are the valid operation code parameters used 5396 ** as the first argument to [sqlite3_test_control()]. 5397 ** 5398 ** These parameters and their meanings are subject to change 5399 ** without notice. These values are for testing purposes only. 5400 ** Applications should not use any of these parameters or the 5401 ** [sqlite3_test_control()] interface. 5402 */ 5403 #define SQLITE_TESTCTRL_FIRST 5 5404 #define SQLITE_TESTCTRL_PRNG_SAVE 5 5405 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 5406 #define SQLITE_TESTCTRL_PRNG_RESET 7 5407 #define SQLITE_TESTCTRL_BITVEC_TEST 8 5408 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 5409 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 5410 #define SQLITE_TESTCTRL_PENDING_BYTE 11 5411 #define SQLITE_TESTCTRL_ASSERT 12 5412 #define SQLITE_TESTCTRL_ALWAYS 13 5413 #define SQLITE_TESTCTRL_RESERVE 14 5414 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 5415 #define SQLITE_TESTCTRL_ISKEYWORD 16 5416 #define SQLITE_TESTCTRL_PGHDRSZ 17 5417 #define SQLITE_TESTCTRL_SCRATCHMALLOC 18 5418 #define SQLITE_TESTCTRL_LAST 18 5419 5420 /* 5421 ** CAPI3REF: SQLite Runtime Status 5422 ** 5423 ** ^This interface is used to retrieve runtime status information 5424 ** about the performance of SQLite, and optionally to reset various 5425 ** highwater marks. ^The first argument is an integer code for 5426 ** the specific parameter to measure. ^(Recognized integer codes 5427 ** are of the form [SQLITE_STATUS_MEMORY_USED | SQLITE_STATUS_...].)^ 5428 ** ^The current value of the parameter is returned into *pCurrent. 5429 ** ^The highest recorded value is returned in *pHighwater. ^If the 5430 ** resetFlag is true, then the highest record value is reset after 5431 ** *pHighwater is written. ^(Some parameters do not record the highest 5432 ** value. For those parameters 5433 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 5434 ** ^(Other parameters record only the highwater mark and not the current 5435 ** value. For these latter parameters nothing is written into *pCurrent.)^ 5436 ** 5437 ** ^The sqlite3_status() routine returns SQLITE_OK on success and a 5438 ** non-zero [error code] on failure. 5439 ** 5440 ** This routine is threadsafe but is not atomic. This routine can be 5441 ** called while other threads are running the same or different SQLite 5442 ** interfaces. However the values returned in *pCurrent and 5443 ** *pHighwater reflect the status of SQLite at different points in time 5444 ** and it is possible that another thread might change the parameter 5445 ** in between the times when *pCurrent and *pHighwater are written. 5446 ** 5447 ** See also: [sqlite3_db_status()] 5448 */ 5449 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 5450 5451 5452 /* 5453 ** CAPI3REF: Status Parameters 5454 ** 5455 ** These integer constants designate various run-time status parameters 5456 ** that can be returned by [sqlite3_status()]. 5457 ** 5458 ** <dl> 5459 ** ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 5460 ** <dd>This parameter is the current amount of memory checked out 5461 ** using [sqlite3_malloc()], either directly or indirectly. The 5462 ** figure includes calls made to [sqlite3_malloc()] by the application 5463 ** and internal memory usage by the SQLite library. Scratch memory 5464 ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 5465 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 5466 ** this parameter. The amount returned is the sum of the allocation 5467 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 5468 ** 5469 ** ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 5470 ** <dd>This parameter records the largest memory allocation request 5471 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 5472 ** internal equivalents). Only the value returned in the 5473 ** *pHighwater parameter to [sqlite3_status()] is of interest. 5474 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 5475 ** 5476 ** ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 5477 ** <dd>This parameter records the number of separate memory allocations 5478 ** currently checked out.</dd>)^ 5479 ** 5480 ** ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 5481 ** <dd>This parameter returns the number of pages used out of the 5482 ** [pagecache memory allocator] that was configured using 5483 ** [SQLITE_CONFIG_PAGECACHE]. The 5484 ** value returned is in pages, not in bytes.</dd>)^ 5485 ** 5486 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 5487 ** <dd>This parameter returns the number of bytes of page cache 5488 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 5489 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 5490 ** returned value includes allocations that overflowed because they 5491 ** where too large (they were larger than the "sz" parameter to 5492 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 5493 ** no space was left in the page cache.</dd>)^ 5494 ** 5495 ** ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 5496 ** <dd>This parameter records the largest memory allocation request 5497 ** handed to [pagecache memory allocator]. Only the value returned in the 5498 ** *pHighwater parameter to [sqlite3_status()] is of interest. 5499 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 5500 ** 5501 ** ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 5502 ** <dd>This parameter returns the number of allocations used out of the 5503 ** [scratch memory allocator] configured using 5504 ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 5505 ** in bytes. Since a single thread may only have one scratch allocation 5506 ** outstanding at time, this parameter also reports the number of threads 5507 ** using scratch memory at the same time.</dd>)^ 5508 ** 5509 ** ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 5510 ** <dd>This parameter returns the number of bytes of scratch memory 5511 ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 5512 ** buffer and where forced to overflow to [sqlite3_malloc()]. The values 5513 ** returned include overflows because the requested allocation was too 5514 ** larger (that is, because the requested allocation was larger than the 5515 ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 5516 ** slots were available. 5517 ** </dd>)^ 5518 ** 5519 ** ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 5520 ** <dd>This parameter records the largest memory allocation request 5521 ** handed to [scratch memory allocator]. Only the value returned in the 5522 ** *pHighwater parameter to [sqlite3_status()] is of interest. 5523 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 5524 ** 5525 ** ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 5526 ** <dd>This parameter records the deepest parser stack. It is only 5527 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 5528 ** </dl> 5529 ** 5530 ** New status parameters may be added from time to time. 5531 */ 5532 #define SQLITE_STATUS_MEMORY_USED 0 5533 #define SQLITE_STATUS_PAGECACHE_USED 1 5534 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 5535 #define SQLITE_STATUS_SCRATCH_USED 3 5536 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 5537 #define SQLITE_STATUS_MALLOC_SIZE 5 5538 #define SQLITE_STATUS_PARSER_STACK 6 5539 #define SQLITE_STATUS_PAGECACHE_SIZE 7 5540 #define SQLITE_STATUS_SCRATCH_SIZE 8 5541 #define SQLITE_STATUS_MALLOC_COUNT 9 5542 5543 /* 5544 ** CAPI3REF: Database Connection Status 5545 ** 5546 ** ^This interface is used to retrieve runtime status information 5547 ** about a single [database connection]. ^The first argument is the 5548 ** database connection object to be interrogated. ^The second argument 5549 ** is an integer constant, taken from the set of 5550 ** [SQLITE_DBSTATUS_LOOKASIDE_USED | SQLITE_DBSTATUS_*] macros, that 5551 ** determines the parameter to interrogate. The set of 5552 ** [SQLITE_DBSTATUS_LOOKASIDE_USED | SQLITE_DBSTATUS_*] macros is likely 5553 ** to grow in future releases of SQLite. 5554 ** 5555 ** ^The current value of the requested parameter is written into *pCur 5556 ** and the highest instantaneous value is written into *pHiwtr. ^If 5557 ** the resetFlg is true, then the highest instantaneous value is 5558 ** reset back down to the current value. 5559 ** 5560 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 5561 ** non-zero [error code] on failure. 5562 ** 5563 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 5564 */ 5565 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 5566 5567 /* 5568 ** CAPI3REF: Status Parameters for database connections 5569 ** 5570 ** These constants are the available integer "verbs" that can be passed as 5571 ** the second argument to the [sqlite3_db_status()] interface. 5572 ** 5573 ** New verbs may be added in future releases of SQLite. Existing verbs 5574 ** might be discontinued. Applications should check the return code from 5575 ** [sqlite3_db_status()] to make sure that the call worked. 5576 ** The [sqlite3_db_status()] interface will return a non-zero error code 5577 ** if a discontinued or unsupported verb is invoked. 5578 ** 5579 ** <dl> 5580 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 5581 ** <dd>This parameter returns the number of lookaside memory slots currently 5582 ** checked out.</dd>)^ 5583 ** 5584 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 5585 ** <dd>This parameter returns the number malloc attempts that were 5586 ** satisfied using lookaside memory. Only the high-water value is meaningful; 5587 ** the current value is always zero.)^ 5588 ** 5589 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 5590 ** <dd>This parameter returns the number malloc attempts that might have 5591 ** been satisfied using lookaside memory but failed due to the amount of 5592 ** memory requested being larger than the lookaside slot size. 5593 ** Only the high-water value is meaningful; 5594 ** the current value is always zero.)^ 5595 ** 5596 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 5597 ** <dd>This parameter returns the number malloc attempts that might have 5598 ** been satisfied using lookaside memory but failed due to all lookaside 5599 ** memory already being in use. 5600 ** Only the high-water value is meaningful; 5601 ** the current value is always zero.)^ 5602 ** 5603 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 5604 ** <dd>This parameter returns the approximate number of of bytes of heap 5605 ** memory used by all pager caches associated with the database connection.)^ 5606 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 5607 ** 5608 ** ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 5609 ** <dd>This parameter returns the approximate number of of bytes of heap 5610 ** memory used to store the schema for all databases associated 5611 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 5612 ** ^The full amount of memory used by the schemas is reported, even if the 5613 ** schema memory is shared with other database connections due to 5614 ** [shared cache mode] being enabled. 5615 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 5616 ** 5617 ** ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 5618 ** <dd>This parameter returns the approximate number of of bytes of heap 5619 ** and lookaside memory used by all prepared statements associated with 5620 ** the database connection.)^ 5621 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 5622 ** </dd> 5623 ** </dl> 5624 */ 5625 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 5626 #define SQLITE_DBSTATUS_CACHE_USED 1 5627 #define SQLITE_DBSTATUS_SCHEMA_USED 2 5628 #define SQLITE_DBSTATUS_STMT_USED 3 5629 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 5630 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 5631 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 5632 #define SQLITE_DBSTATUS_MAX 6 /* Largest defined DBSTATUS */ 5633 5634 5635 /* 5636 ** CAPI3REF: Prepared Statement Status 5637 ** 5638 ** ^(Each prepared statement maintains various 5639 ** [SQLITE_STMTSTATUS_SORT | counters] that measure the number 5640 ** of times it has performed specific operations.)^ These counters can 5641 ** be used to monitor the performance characteristics of the prepared 5642 ** statements. For example, if the number of table steps greatly exceeds 5643 ** the number of table searches or result rows, that would tend to indicate 5644 ** that the prepared statement is using a full table scan rather than 5645 ** an index. 5646 ** 5647 ** ^(This interface is used to retrieve and reset counter values from 5648 ** a [prepared statement]. The first argument is the prepared statement 5649 ** object to be interrogated. The second argument 5650 ** is an integer code for a specific [SQLITE_STMTSTATUS_SORT | counter] 5651 ** to be interrogated.)^ 5652 ** ^The current value of the requested counter is returned. 5653 ** ^If the resetFlg is true, then the counter is reset to zero after this 5654 ** interface call returns. 5655 ** 5656 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 5657 */ 5658 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 5659 5660 /* 5661 ** CAPI3REF: Status Parameters for prepared statements 5662 ** 5663 ** These preprocessor macros define integer codes that name counter 5664 ** values associated with the [sqlite3_stmt_status()] interface. 5665 ** The meanings of the various counters are as follows: 5666 ** 5667 ** <dl> 5668 ** <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 5669 ** <dd>^This is the number of times that SQLite has stepped forward in 5670 ** a table as part of a full table scan. Large numbers for this counter 5671 ** may indicate opportunities for performance improvement through 5672 ** careful use of indices.</dd> 5673 ** 5674 ** <dt>SQLITE_STMTSTATUS_SORT</dt> 5675 ** <dd>^This is the number of sort operations that have occurred. 5676 ** A non-zero value in this counter may indicate an opportunity to 5677 ** improvement performance through careful use of indices.</dd> 5678 ** 5679 ** <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 5680 ** <dd>^This is the number of rows inserted into transient indices that 5681 ** were created automatically in order to help joins run faster. 5682 ** A non-zero value in this counter may indicate an opportunity to 5683 ** improvement performance by adding permanent indices that do not 5684 ** need to be reinitialized each time the statement is run.</dd> 5685 ** 5686 ** </dl> 5687 */ 5688 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 5689 #define SQLITE_STMTSTATUS_SORT 2 5690 #define SQLITE_STMTSTATUS_AUTOINDEX 3 5691 5692 /* 5693 ** CAPI3REF: Custom Page Cache Object 5694 ** 5695 ** The sqlite3_pcache type is opaque. It is implemented by 5696 ** the pluggable module. The SQLite core has no knowledge of 5697 ** its size or internal structure and never deals with the 5698 ** sqlite3_pcache object except by holding and passing pointers 5699 ** to the object. 5700 ** 5701 ** See [sqlite3_pcache_methods] for additional information. 5702 */ 5703 typedef struct sqlite3_pcache sqlite3_pcache; 5704 5705 /* 5706 ** CAPI3REF: Application Defined Page Cache. 5707 ** KEYWORDS: {page cache} 5708 ** 5709 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE], ...) interface can 5710 ** register an alternative page cache implementation by passing in an 5711 ** instance of the sqlite3_pcache_methods structure.)^ 5712 ** In many applications, most of the heap memory allocated by 5713 ** SQLite is used for the page cache. 5714 ** By implementing a 5715 ** custom page cache using this API, an application can better control 5716 ** the amount of memory consumed by SQLite, the way in which 5717 ** that memory is allocated and released, and the policies used to 5718 ** determine exactly which parts of a database file are cached and for 5719 ** how long. 5720 ** 5721 ** The alternative page cache mechanism is an 5722 ** extreme measure that is only needed by the most demanding applications. 5723 ** The built-in page cache is recommended for most uses. 5724 ** 5725 ** ^(The contents of the sqlite3_pcache_methods structure are copied to an 5726 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 5727 ** the application may discard the parameter after the call to 5728 ** [sqlite3_config()] returns.)^ 5729 ** 5730 ** ^(The xInit() method is called once for each effective 5731 ** call to [sqlite3_initialize()])^ 5732 ** (usually only once during the lifetime of the process). ^(The xInit() 5733 ** method is passed a copy of the sqlite3_pcache_methods.pArg value.)^ 5734 ** The intent of the xInit() method is to set up global data structures 5735 ** required by the custom page cache implementation. 5736 ** ^(If the xInit() method is NULL, then the 5737 ** built-in default page cache is used instead of the application defined 5738 ** page cache.)^ 5739 ** 5740 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 5741 ** It can be used to clean up 5742 ** any outstanding resources before process shutdown, if required. 5743 ** ^The xShutdown() method may be NULL. 5744 ** 5745 ** ^SQLite automatically serializes calls to the xInit method, 5746 ** so the xInit method need not be threadsafe. ^The 5747 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 5748 ** not need to be threadsafe either. All other methods must be threadsafe 5749 ** in multithreaded applications. 5750 ** 5751 ** ^SQLite will never invoke xInit() more than once without an intervening 5752 ** call to xShutdown(). 5753 ** 5754 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 5755 ** SQLite will typically create one cache instance for each open database file, 5756 ** though this is not guaranteed. ^The 5757 ** first parameter, szPage, is the size in bytes of the pages that must 5758 ** be allocated by the cache. ^szPage will not be a power of two. ^szPage 5759 ** will the page size of the database file that is to be cached plus an 5760 ** increment (here called "R") of less than 250. SQLite will use the 5761 ** extra R bytes on each page to store metadata about the underlying 5762 ** database page on disk. The value of R depends 5763 ** on the SQLite version, the target platform, and how SQLite was compiled. 5764 ** ^(R is constant for a particular build of SQLite. Except, there are two 5765 ** distinct values of R when SQLite is compiled with the proprietary 5766 ** ZIPVFS extension.)^ ^The second argument to 5767 ** xCreate(), bPurgeable, is true if the cache being created will 5768 ** be used to cache database pages of a file stored on disk, or 5769 ** false if it is used for an in-memory database. The cache implementation 5770 ** does not have to do anything special based with the value of bPurgeable; 5771 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 5772 ** never invoke xUnpin() except to deliberately delete a page. 5773 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 5774 ** false will always have the "discard" flag set to true. 5775 ** ^Hence, a cache created with bPurgeable false will 5776 ** never contain any unpinned pages. 5777 ** 5778 ** ^(The xCachesize() method may be called at any time by SQLite to set the 5779 ** suggested maximum cache-size (number of pages stored by) the cache 5780 ** instance passed as the first argument. This is the value configured using 5781 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 5782 ** parameter, the implementation is not required to do anything with this 5783 ** value; it is advisory only. 5784 ** 5785 ** The xPagecount() method must return the number of pages currently 5786 ** stored in the cache, both pinned and unpinned. 5787 ** 5788 ** The xFetch() method locates a page in the cache and returns a pointer to 5789 ** the page, or a NULL pointer. 5790 ** A "page", in this context, means a buffer of szPage bytes aligned at an 5791 ** 8-byte boundary. The page to be fetched is determined by the key. ^The 5792 ** mimimum key value is 1. After it has been retrieved using xFetch, the page 5793 ** is considered to be "pinned". 5794 ** 5795 ** If the requested page is already in the page cache, then the page cache 5796 ** implementation must return a pointer to the page buffer with its content 5797 ** intact. If the requested page is not already in the cache, then the 5798 ** cache implementation should use the value of the createFlag 5799 ** parameter to help it determined what action to take: 5800 ** 5801 ** <table border=1 width=85% align=center> 5802 ** <tr><th> createFlag <th> Behaviour when page is not already in cache 5803 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 5804 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 5805 ** Otherwise return NULL. 5806 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 5807 ** NULL if allocating a new page is effectively impossible. 5808 ** </table> 5809 ** 5810 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 5811 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 5812 ** failed.)^ In between the to xFetch() calls, SQLite may 5813 ** attempt to unpin one or more cache pages by spilling the content of 5814 ** pinned pages to disk and synching the operating system disk cache. 5815 ** 5816 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 5817 ** as its second argument. If the third parameter, discard, is non-zero, 5818 ** then the page must be evicted from the cache. 5819 ** ^If the discard parameter is 5820 ** zero, then the page may be discarded or retained at the discretion of 5821 ** page cache implementation. ^The page cache implementation 5822 ** may choose to evict unpinned pages at any time. 5823 ** 5824 ** The cache must not perform any reference counting. A single 5825 ** call to xUnpin() unpins the page regardless of the number of prior calls 5826 ** to xFetch(). 5827 ** 5828 ** The xRekey() method is used to change the key value associated with the 5829 ** page passed as the second argument. If the cache 5830 ** previously contains an entry associated with newKey, it must be 5831 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 5832 ** to be pinned. 5833 ** 5834 ** When SQLite calls the xTruncate() method, the cache must discard all 5835 ** existing cache entries with page numbers (keys) greater than or equal 5836 ** to the value of the iLimit parameter passed to xTruncate(). If any 5837 ** of these pages are pinned, they are implicitly unpinned, meaning that 5838 ** they can be safely discarded. 5839 ** 5840 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 5841 ** All resources associated with the specified cache should be freed. ^After 5842 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 5843 ** handle invalid, and will not use it with any other sqlite3_pcache_methods 5844 ** functions. 5845 */ 5846 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 5847 struct sqlite3_pcache_methods { 5848 void *pArg; 5849 int (*xInit)(void*); 5850 void (*xShutdown)(void*); 5851 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 5852 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 5853 int (*xPagecount)(sqlite3_pcache*); 5854 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 5855 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 5856 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 5857 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 5858 void (*xDestroy)(sqlite3_pcache*); 5859 }; 5860 5861 /* 5862 ** CAPI3REF: Online Backup Object 5863 ** 5864 ** The sqlite3_backup object records state information about an ongoing 5865 ** online backup operation. ^The sqlite3_backup object is created by 5866 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 5867 ** [sqlite3_backup_finish()]. 5868 ** 5869 ** See Also: [Using the SQLite Online Backup API] 5870 */ 5871 typedef struct sqlite3_backup sqlite3_backup; 5872 5873 /* 5874 ** CAPI3REF: Online Backup API. 5875 ** 5876 ** The backup API copies the content of one database into another. 5877 ** It is useful either for creating backups of databases or 5878 ** for copying in-memory databases to or from persistent files. 5879 ** 5880 ** See Also: [Using the SQLite Online Backup API] 5881 ** 5882 ** ^SQLite holds a write transaction open on the destination database file 5883 ** for the duration of the backup operation. 5884 ** ^The source database is read-locked only while it is being read; 5885 ** it is not locked continuously for the entire backup operation. 5886 ** ^Thus, the backup may be performed on a live source database without 5887 ** preventing other database connections from 5888 ** reading or writing to the source database while the backup is underway. 5889 ** 5890 ** ^(To perform a backup operation: 5891 ** <ol> 5892 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 5893 ** backup, 5894 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 5895 ** the data between the two databases, and finally 5896 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 5897 ** associated with the backup operation. 5898 ** </ol>)^ 5899 ** There should be exactly one call to sqlite3_backup_finish() for each 5900 ** successful call to sqlite3_backup_init(). 5901 ** 5902 ** <b>sqlite3_backup_init()</b> 5903 ** 5904 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 5905 ** [database connection] associated with the destination database 5906 ** and the database name, respectively. 5907 ** ^The database name is "main" for the main database, "temp" for the 5908 ** temporary database, or the name specified after the AS keyword in 5909 ** an [ATTACH] statement for an attached database. 5910 ** ^The S and M arguments passed to 5911 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 5912 ** and database name of the source database, respectively. 5913 ** ^The source and destination [database connections] (parameters S and D) 5914 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 5915 ** an error. 5916 ** 5917 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 5918 ** returned and an error code and error message are stored in the 5919 ** destination [database connection] D. 5920 ** ^The error code and message for the failed call to sqlite3_backup_init() 5921 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 5922 ** [sqlite3_errmsg16()] functions. 5923 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 5924 ** [sqlite3_backup] object. 5925 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 5926 ** sqlite3_backup_finish() functions to perform the specified backup 5927 ** operation. 5928 ** 5929 ** <b>sqlite3_backup_step()</b> 5930 ** 5931 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 5932 ** the source and destination databases specified by [sqlite3_backup] object B. 5933 ** ^If N is negative, all remaining source pages are copied. 5934 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 5935 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 5936 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 5937 ** from source to destination, then it returns [SQLITE_DONE]. 5938 ** ^If an error occurs while running sqlite3_backup_step(B,N), 5939 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 5940 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 5941 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 5942 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 5943 ** 5944 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 5945 ** <ol> 5946 ** <li> the destination database was opened read-only, or 5947 ** <li> the destination database is using write-ahead-log journaling 5948 ** and the destination and source page sizes differ, or 5949 ** <li> the destination database is an in-memory database and the 5950 ** destination and source page sizes differ. 5951 ** </ol>)^ 5952 ** 5953 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 5954 ** the [sqlite3_busy_handler | busy-handler function] 5955 ** is invoked (if one is specified). ^If the 5956 ** busy-handler returns non-zero before the lock is available, then 5957 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 5958 ** sqlite3_backup_step() can be retried later. ^If the source 5959 ** [database connection] 5960 ** is being used to write to the source database when sqlite3_backup_step() 5961 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 5962 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 5963 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 5964 ** [SQLITE_READONLY] is returned, then 5965 ** there is no point in retrying the call to sqlite3_backup_step(). These 5966 ** errors are considered fatal.)^ The application must accept 5967 ** that the backup operation has failed and pass the backup operation handle 5968 ** to the sqlite3_backup_finish() to release associated resources. 5969 ** 5970 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 5971 ** on the destination file. ^The exclusive lock is not released until either 5972 ** sqlite3_backup_finish() is called or the backup operation is complete 5973 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 5974 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 5975 ** lasts for the duration of the sqlite3_backup_step() call. 5976 ** ^Because the source database is not locked between calls to 5977 ** sqlite3_backup_step(), the source database may be modified mid-way 5978 ** through the backup process. ^If the source database is modified by an 5979 ** external process or via a database connection other than the one being 5980 ** used by the backup operation, then the backup will be automatically 5981 ** restarted by the next call to sqlite3_backup_step(). ^If the source 5982 ** database is modified by the using the same database connection as is used 5983 ** by the backup operation, then the backup database is automatically 5984 ** updated at the same time. 5985 ** 5986 ** <b>sqlite3_backup_finish()</b> 5987 ** 5988 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 5989 ** application wishes to abandon the backup operation, the application 5990 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 5991 ** ^The sqlite3_backup_finish() interfaces releases all 5992 ** resources associated with the [sqlite3_backup] object. 5993 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 5994 ** active write-transaction on the destination database is rolled back. 5995 ** The [sqlite3_backup] object is invalid 5996 ** and may not be used following a call to sqlite3_backup_finish(). 5997 ** 5998 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 5999 ** sqlite3_backup_step() errors occurred, regardless or whether or not 6000 ** sqlite3_backup_step() completed. 6001 ** ^If an out-of-memory condition or IO error occurred during any prior 6002 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 6003 ** sqlite3_backup_finish() returns the corresponding [error code]. 6004 ** 6005 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 6006 ** is not a permanent error and does not affect the return value of 6007 ** sqlite3_backup_finish(). 6008 ** 6009 ** <b>sqlite3_backup_remaining(), sqlite3_backup_pagecount()</b> 6010 ** 6011 ** ^Each call to sqlite3_backup_step() sets two values inside 6012 ** the [sqlite3_backup] object: the number of pages still to be backed 6013 ** up and the total number of pages in the source database file. 6014 ** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces 6015 ** retrieve these two values, respectively. 6016 ** 6017 ** ^The values returned by these functions are only updated by 6018 ** sqlite3_backup_step(). ^If the source database is modified during a backup 6019 ** operation, then the values are not updated to account for any extra 6020 ** pages that need to be updated or the size of the source database file 6021 ** changing. 6022 ** 6023 ** <b>Concurrent Usage of Database Handles</b> 6024 ** 6025 ** ^The source [database connection] may be used by the application for other 6026 ** purposes while a backup operation is underway or being initialized. 6027 ** ^If SQLite is compiled and configured to support threadsafe database 6028 ** connections, then the source database connection may be used concurrently 6029 ** from within other threads. 6030 ** 6031 ** However, the application must guarantee that the destination 6032 ** [database connection] is not passed to any other API (by any thread) after 6033 ** sqlite3_backup_init() is called and before the corresponding call to 6034 ** sqlite3_backup_finish(). SQLite does not currently check to see 6035 ** if the application incorrectly accesses the destination [database connection] 6036 ** and so no error code is reported, but the operations may malfunction 6037 ** nevertheless. Use of the destination database connection while a 6038 ** backup is in progress might also also cause a mutex deadlock. 6039 ** 6040 ** If running in [shared cache mode], the application must 6041 ** guarantee that the shared cache used by the destination database 6042 ** is not accessed while the backup is running. In practice this means 6043 ** that the application must guarantee that the disk file being 6044 ** backed up to is not accessed by any connection within the process, 6045 ** not just the specific connection that was passed to sqlite3_backup_init(). 6046 ** 6047 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 6048 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 6049 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 6050 ** APIs are not strictly speaking threadsafe. If they are invoked at the 6051 ** same time as another thread is invoking sqlite3_backup_step() it is 6052 ** possible that they return invalid values. 6053 */ 6054 SQLITE_API sqlite3_backup *sqlite3_backup_init( 6055 sqlite3 *pDest, /* Destination database handle */ 6056 const char *zDestName, /* Destination database name */ 6057 sqlite3 *pSource, /* Source database handle */ 6058 const char *zSourceName /* Source database name */ 6059 ); 6060 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 6061 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 6062 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 6063 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 6064 6065 /* 6066 ** CAPI3REF: Unlock Notification 6067 ** 6068 ** ^When running in shared-cache mode, a database operation may fail with 6069 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 6070 ** individual tables within the shared-cache cannot be obtained. See 6071 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 6072 ** ^This API may be used to register a callback that SQLite will invoke 6073 ** when the connection currently holding the required lock relinquishes it. 6074 ** ^This API is only available if the library was compiled with the 6075 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 6076 ** 6077 ** See Also: [Using the SQLite Unlock Notification Feature]. 6078 ** 6079 ** ^Shared-cache locks are released when a database connection concludes 6080 ** its current transaction, either by committing it or rolling it back. 6081 ** 6082 ** ^When a connection (known as the blocked connection) fails to obtain a 6083 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 6084 ** identity of the database connection (the blocking connection) that 6085 ** has locked the required resource is stored internally. ^After an 6086 ** application receives an SQLITE_LOCKED error, it may call the 6087 ** sqlite3_unlock_notify() method with the blocked connection handle as 6088 ** the first argument to register for a callback that will be invoked 6089 ** when the blocking connections current transaction is concluded. ^The 6090 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 6091 ** call that concludes the blocking connections transaction. 6092 ** 6093 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 6094 ** there is a chance that the blocking connection will have already 6095 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 6096 ** If this happens, then the specified callback is invoked immediately, 6097 ** from within the call to sqlite3_unlock_notify().)^ 6098 ** 6099 ** ^If the blocked connection is attempting to obtain a write-lock on a 6100 ** shared-cache table, and more than one other connection currently holds 6101 ** a read-lock on the same table, then SQLite arbitrarily selects one of 6102 ** the other connections to use as the blocking connection. 6103 ** 6104 ** ^(There may be at most one unlock-notify callback registered by a 6105 ** blocked connection. If sqlite3_unlock_notify() is called when the 6106 ** blocked connection already has a registered unlock-notify callback, 6107 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 6108 ** called with a NULL pointer as its second argument, then any existing 6109 ** unlock-notify callback is canceled. ^The blocked connections 6110 ** unlock-notify callback may also be canceled by closing the blocked 6111 ** connection using [sqlite3_close()]. 6112 ** 6113 ** The unlock-notify callback is not reentrant. If an application invokes 6114 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 6115 ** crash or deadlock may be the result. 6116 ** 6117 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 6118 ** returns SQLITE_OK. 6119 ** 6120 ** <b>Callback Invocation Details</b> 6121 ** 6122 ** When an unlock-notify callback is registered, the application provides a 6123 ** single void* pointer that is passed to the callback when it is invoked. 6124 ** However, the signature of the callback function allows SQLite to pass 6125 ** it an array of void* context pointers. The first argument passed to 6126 ** an unlock-notify callback is a pointer to an array of void* pointers, 6127 ** and the second is the number of entries in the array. 6128 ** 6129 ** When a blocking connections transaction is concluded, there may be 6130 ** more than one blocked connection that has registered for an unlock-notify 6131 ** callback. ^If two or more such blocked connections have specified the 6132 ** same callback function, then instead of invoking the callback function 6133 ** multiple times, it is invoked once with the set of void* context pointers 6134 ** specified by the blocked connections bundled together into an array. 6135 ** This gives the application an opportunity to prioritize any actions 6136 ** related to the set of unblocked database connections. 6137 ** 6138 ** <b>Deadlock Detection</b> 6139 ** 6140 ** Assuming that after registering for an unlock-notify callback a 6141 ** database waits for the callback to be issued before taking any further 6142 ** action (a reasonable assumption), then using this API may cause the 6143 ** application to deadlock. For example, if connection X is waiting for 6144 ** connection Y's transaction to be concluded, and similarly connection 6145 ** Y is waiting on connection X's transaction, then neither connection 6146 ** will proceed and the system may remain deadlocked indefinitely. 6147 ** 6148 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 6149 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 6150 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 6151 ** unlock-notify callback is registered. The system is said to be in 6152 ** a deadlocked state if connection A has registered for an unlock-notify 6153 ** callback on the conclusion of connection B's transaction, and connection 6154 ** B has itself registered for an unlock-notify callback when connection 6155 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 6156 ** the system is also considered to be deadlocked if connection B has 6157 ** registered for an unlock-notify callback on the conclusion of connection 6158 ** C's transaction, where connection C is waiting on connection A. ^Any 6159 ** number of levels of indirection are allowed. 6160 ** 6161 ** <b>The "DROP TABLE" Exception</b> 6162 ** 6163 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 6164 ** always appropriate to call sqlite3_unlock_notify(). There is however, 6165 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 6166 ** SQLite checks if there are any currently executing SELECT statements 6167 ** that belong to the same connection. If there are, SQLITE_LOCKED is 6168 ** returned. In this case there is no "blocking connection", so invoking 6169 ** sqlite3_unlock_notify() results in the unlock-notify callback being 6170 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 6171 ** or "DROP INDEX" query, an infinite loop might be the result. 6172 ** 6173 ** One way around this problem is to check the extended error code returned 6174 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 6175 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 6176 ** the special "DROP TABLE/INDEX" case, the extended error code is just 6177 ** SQLITE_LOCKED.)^ 6178 */ 6179 SQLITE_API int sqlite3_unlock_notify( 6180 sqlite3 *pBlocked, /* Waiting connection */ 6181 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 6182 void *pNotifyArg /* Argument to pass to xNotify */ 6183 ); 6184 6185 6186 /* 6187 ** CAPI3REF: String Comparison 6188 ** 6189 ** ^The [sqlite3_strnicmp()] API allows applications and extensions to 6190 ** compare the contents of two buffers containing UTF-8 strings in a 6191 ** case-independent fashion, using the same definition of case independence 6192 ** that SQLite uses internally when comparing identifiers. 6193 */ 6194 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 6195 6196 /* 6197 ** CAPI3REF: Error Logging Interface 6198 ** 6199 ** ^The [sqlite3_log()] interface writes a message into the error log 6200 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 6201 ** ^If logging is enabled, the zFormat string and subsequent arguments are 6202 ** used with [sqlite3_snprintf()] to generate the final output string. 6203 ** 6204 ** The sqlite3_log() interface is intended for use by extensions such as 6205 ** virtual tables, collating functions, and SQL functions. While there is 6206 ** nothing to prevent an application from calling sqlite3_log(), doing so 6207 ** is considered bad form. 6208 ** 6209 ** The zFormat string must not be NULL. 6210 ** 6211 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 6212 ** will not use dynamically allocated memory. The log message is stored in 6213 ** a fixed-length buffer on the stack. If the log message is longer than 6214 ** a few hundred characters, it will be truncated to the length of the 6215 ** buffer. 6216 */ 6217 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 6218 6219 /* 6220 ** CAPI3REF: Write-Ahead Log Commit Hook 6221 ** 6222 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 6223 ** will be invoked each time a database connection commits data to a 6224 ** [write-ahead log] (i.e. whenever a transaction is committed in 6225 ** [journal_mode | journal_mode=WAL mode]). 6226 ** 6227 ** ^The callback is invoked by SQLite after the commit has taken place and 6228 ** the associated write-lock on the database released, so the implementation 6229 ** may read, write or [checkpoint] the database as required. 6230 ** 6231 ** ^The first parameter passed to the callback function when it is invoked 6232 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 6233 ** registering the callback. ^The second is a copy of the database handle. 6234 ** ^The third parameter is the name of the database that was written to - 6235 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 6236 ** is the number of pages currently in the write-ahead log file, 6237 ** including those that were just committed. 6238 ** 6239 ** The callback function should normally return [SQLITE_OK]. ^If an error 6240 ** code is returned, that error will propagate back up through the 6241 ** SQLite code base to cause the statement that provoked the callback 6242 ** to report an error, though the commit will have still occurred. If the 6243 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 6244 ** that does not correspond to any valid SQLite error code, the results 6245 ** are undefined. 6246 ** 6247 ** A single database handle may have at most a single write-ahead log callback 6248 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 6249 ** previously registered write-ahead log callback. ^Note that the 6250 ** [sqlite3_wal_autocheckpoint()] interface and the 6251 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 6252 ** those overwrite any prior [sqlite3_wal_hook()] settings. 6253 */ 6254 SQLITE_API void *sqlite3_wal_hook( 6255 sqlite3*, 6256 int(*)(void *,sqlite3*,const char*,int), 6257 void* 6258 ); 6259 6260 /* 6261 ** CAPI3REF: Configure an auto-checkpoint 6262 ** 6263 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 6264 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 6265 ** to automatically [checkpoint] 6266 ** after committing a transaction if there are N or 6267 ** more frames in the [write-ahead log] file. ^Passing zero or 6268 ** a negative value as the nFrame parameter disables automatic 6269 ** checkpoints entirely. 6270 ** 6271 ** ^The callback registered by this function replaces any existing callback 6272 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 6273 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 6274 ** configured by this function. 6275 ** 6276 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 6277 ** from SQL. 6278 ** 6279 ** ^Every new [database connection] defaults to having the auto-checkpoint 6280 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 6281 ** pages. The use of this interface 6282 ** is only necessary if the default setting is found to be suboptimal 6283 ** for a particular application. 6284 */ 6285 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 6286 6287 /* 6288 ** CAPI3REF: Checkpoint a database 6289 ** 6290 ** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X 6291 ** on [database connection] D to be [checkpointed]. ^If X is NULL or an 6292 ** empty string, then a checkpoint is run on all databases of 6293 ** connection D. ^If the database connection D is not in 6294 ** [WAL | write-ahead log mode] then this interface is a harmless no-op. 6295 ** 6296 ** ^The [wal_checkpoint pragma] can be used to invoke this interface 6297 ** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the 6298 ** [wal_autocheckpoint pragma] can be used to cause this interface to be 6299 ** run whenever the WAL reaches a certain size threshold. 6300 ** 6301 ** See also: [sqlite3_wal_checkpoint_v2()] 6302 */ 6303 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 6304 6305 /* 6306 ** CAPI3REF: Checkpoint a database 6307 ** 6308 ** Run a checkpoint operation on WAL database zDb attached to database 6309 ** handle db. The specific operation is determined by the value of the 6310 ** eMode parameter: 6311 ** 6312 ** <dl> 6313 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 6314 ** Checkpoint as many frames as possible without waiting for any database 6315 ** readers or writers to finish. Sync the db file if all frames in the log 6316 ** are checkpointed. This mode is the same as calling 6317 ** sqlite3_wal_checkpoint(). The busy-handler callback is never invoked. 6318 ** 6319 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 6320 ** This mode blocks (calls the busy-handler callback) until there is no 6321 ** database writer and all readers are reading from the most recent database 6322 ** snapshot. It then checkpoints all frames in the log file and syncs the 6323 ** database file. This call blocks database writers while it is running, 6324 ** but not database readers. 6325 ** 6326 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 6327 ** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after 6328 ** checkpointing the log file it blocks (calls the busy-handler callback) 6329 ** until all readers are reading from the database file only. This ensures 6330 ** that the next client to write to the database file restarts the log file 6331 ** from the beginning. This call blocks database writers while it is running, 6332 ** but not database readers. 6333 ** </dl> 6334 ** 6335 ** If pnLog is not NULL, then *pnLog is set to the total number of frames in 6336 ** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to 6337 ** the total number of checkpointed frames (including any that were already 6338 ** checkpointed when this function is called). *pnLog and *pnCkpt may be 6339 ** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK. 6340 ** If no values are available because of an error, they are both set to -1 6341 ** before returning to communicate this to the caller. 6342 ** 6343 ** All calls obtain an exclusive "checkpoint" lock on the database file. If 6344 ** any other process is running a checkpoint operation at the same time, the 6345 ** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a 6346 ** busy-handler configured, it will not be invoked in this case. 6347 ** 6348 ** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive 6349 ** "writer" lock on the database file. If the writer lock cannot be obtained 6350 ** immediately, and a busy-handler is configured, it is invoked and the writer 6351 ** lock retried until either the busy-handler returns 0 or the lock is 6352 ** successfully obtained. The busy-handler is also invoked while waiting for 6353 ** database readers as described above. If the busy-handler returns 0 before 6354 ** the writer lock is obtained or while waiting for database readers, the 6355 ** checkpoint operation proceeds from that point in the same way as 6356 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 6357 ** without blocking any further. SQLITE_BUSY is returned in this case. 6358 ** 6359 ** If parameter zDb is NULL or points to a zero length string, then the 6360 ** specified operation is attempted on all WAL databases. In this case the 6361 ** values written to output parameters *pnLog and *pnCkpt are undefined. If 6362 ** an SQLITE_BUSY error is encountered when processing one or more of the 6363 ** attached WAL databases, the operation is still attempted on any remaining 6364 ** attached databases and SQLITE_BUSY is returned to the caller. If any other 6365 ** error occurs while processing an attached database, processing is abandoned 6366 ** and the error code returned to the caller immediately. If no error 6367 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 6368 ** databases, SQLITE_OK is returned. 6369 ** 6370 ** If database zDb is the name of an attached database that is not in WAL 6371 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If 6372 ** zDb is not NULL (or a zero length string) and is not the name of any 6373 ** attached database, SQLITE_ERROR is returned to the caller. 6374 */ 6375 SQLITE_API int sqlite3_wal_checkpoint_v2( 6376 sqlite3 *db, /* Database handle */ 6377 const char *zDb, /* Name of attached database (or NULL) */ 6378 int eMode, /* SQLITE_CHECKPOINT_* value */ 6379 int *pnLog, /* OUT: Size of WAL log in frames */ 6380 int *pnCkpt /* OUT: Total number of frames checkpointed */ 6381 ); 6382 6383 /* 6384 ** CAPI3REF: Checkpoint operation parameters 6385 ** 6386 ** These constants can be used as the 3rd parameter to 6387 ** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()] 6388 ** documentation for additional information about the meaning and use of 6389 ** each of these values. 6390 */ 6391 #define SQLITE_CHECKPOINT_PASSIVE 0 6392 #define SQLITE_CHECKPOINT_FULL 1 6393 #define SQLITE_CHECKPOINT_RESTART 2 6394 6395 6396 /* Begin recover.patch for Chromium */ 6397 /* 6398 ** Call to initialize the recover virtual-table modules (see recover.c). 6399 ** 6400 ** This could be loaded by default in main.c, but that would make the 6401 ** virtual table available to Web SQL. Breaking it out allows only 6402 ** selected users to enable it (currently sql/recovery.cc). 6403 */ 6404 int recoverVtableInit(sqlite3 *db); 6405 /* End recover.patch for Chromium */ 6406 6407 /* 6408 ** Undo the hack that converts floating point types to integer for 6409 ** builds on processors without floating point support. 6410 */ 6411 #ifdef SQLITE_OMIT_FLOATING_POINT 6412 # undef double 6413 #endif 6414 6415 #ifdef __cplusplus 6416 } /* End of the 'extern "C"' block */ 6417 #endif 6418 #endif 6419 6420 /* 6421 ** 2010 August 30 6422 ** 6423 ** The author disclaims copyright to this source code. In place of 6424 ** a legal notice, here is a blessing: 6425 ** 6426 ** May you do good and not evil. 6427 ** May you find forgiveness for yourself and forgive others. 6428 ** May you share freely, never taking more than you give. 6429 ** 6430 ************************************************************************* 6431 */ 6432 6433 #ifndef _SQLITE3RTREE_H_ 6434 #define _SQLITE3RTREE_H_ 6435 6436 6437 #ifdef __cplusplus 6438 extern "C" { 6439 #endif 6440 6441 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 6442 6443 /* 6444 ** Register a geometry callback named zGeom that can be used as part of an 6445 ** R-Tree geometry query as follows: 6446 ** 6447 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 6448 */ 6449 SQLITE_API int sqlite3_rtree_geometry_callback( 6450 sqlite3 *db, 6451 const char *zGeom, 6452 int (*xGeom)(sqlite3_rtree_geometry *, int nCoord, double *aCoord, int *pRes), 6453 void *pContext 6454 ); 6455 6456 6457 /* 6458 ** A pointer to a structure of the following type is passed as the first 6459 ** argument to callbacks registered using rtree_geometry_callback(). 6460 */ 6461 struct sqlite3_rtree_geometry { 6462 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 6463 int nParam; /* Size of array aParam[] */ 6464 double *aParam; /* Parameters passed to SQL geom function */ 6465 void *pUser; /* Callback implementation user data */ 6466 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 6467 }; 6468 6469 6470 #ifdef __cplusplus 6471 } /* end of the 'extern "C"' block */ 6472 #endif 6473 6474 #endif /* ifndef _SQLITE3RTREE_H_ */ 6475 6476
