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| 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 /* | |
| 53 ** These no-op macros are used in front of interfaces to mark those | |
| 54 ** interfaces as either deprecated or experimental. New applications | |
| 55 ** should not use deprecated interfaces - they are support for backwards | |
| 56 ** compatibility only. Application writers should be aware that | |
| 57 ** experimental interfaces are subject to change in point releases. | |
| 58 ** | |
| 59 ** These macros used to resolve to various kinds of compiler magic that | |
| 60 ** would generate warning messages when they were used. But that | |
| 61 ** compiler magic ended up generating such a flurry of bug reports | |
| 62 ** that we have taken it all out and gone back to using simple | |
| 63 ** noop macros. | |
| 64 */ | |
| 65 #define SQLITE_DEPRECATED | |
| 66 #define SQLITE_EXPERIMENTAL | |
| 67 | |
| 68 /* | |
| 69 ** Ensure these symbols were not defined by some previous header file. | |
| 70 */ | |
| 71 #ifdef SQLITE_VERSION | |
| 72 # undef SQLITE_VERSION | |
| 73 #endif | |
| 74 #ifdef SQLITE_VERSION_NUMBER | |
| 75 # undef SQLITE_VERSION_NUMBER | |
| 76 #endif | |
| 77 | |
| 78 /* | |
| 79 ** CAPI3REF: Compile-Time Library Version Numbers {H10010} <S60100> | |
| 80 ** | |
| 81 ** The SQLITE_VERSION and SQLITE_VERSION_NUMBER #defines in | |
| 82 ** the sqlite3.h file specify the version of SQLite with which | |
| 83 ** that header file is associated. | |
| 84 ** | |
| 85 ** The "version" of SQLite is a string of the form "W.X.Y" or "W.X.Y.Z". | |
| 86 ** The W value is major version number and is always 3 in SQLite3. | |
| 87 ** The W value only changes when backwards compatibility is | |
| 88 ** broken and we intend to never break backwards compatibility. | |
| 89 ** The X value is the minor version number and only changes when | |
| 90 ** there are major feature enhancements that are forwards compatible | |
| 91 ** but not backwards compatible. | |
| 92 ** The Y value is the release number and is incremented with | |
| 93 ** each release but resets back to 0 whenever X is incremented. | |
| 94 ** The Z value only appears on branch releases. | |
| 95 ** | |
| 96 ** The SQLITE_VERSION_NUMBER is an integer that is computed as | |
| 97 ** follows: | |
| 98 ** | |
| 99 ** <blockquote><pre> | |
| 100 ** SQLITE_VERSION_NUMBER = W*1000000 + X*1000 + Y | |
| 101 ** </pre></blockquote> | |
| 102 ** | |
| 103 ** Since version 3.6.18, SQLite source code has been stored in the | |
| 104 ** <a href="http://www.fossil-scm.org/">fossil configuration management | |
| 105 ** system</a>. The SQLITE_SOURCE_ID | |
| 106 ** macro is a string which identifies a particular check-in of SQLite | |
| 107 ** within its configuration management system. The string contains the | |
| 108 ** date and time of the check-in (UTC) and an SHA1 hash of the entire | |
| 109 ** source tree. | |
| 110 ** | |
| 111 ** See also: [sqlite3_libversion()], | |
| 112 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], | |
| 113 ** [sqlite_version()] and [sqlite_source_id()]. | |
| 114 ** | |
| 115 ** Requirements: [H10011] [H10014] | |
| 116 */ | |
| 117 #define SQLITE_VERSION "--VERS--" | |
| 118 #define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- | |
| 119 #define SQLITE_SOURCE_ID "--SOURCE-ID--" | |
| 120 | |
| 121 /* | |
| 122 ** CAPI3REF: Run-Time Library Version Numbers {H10020} <S60100> | |
| 123 ** KEYWORDS: sqlite3_version | |
| 124 ** | |
| 125 ** These interfaces provide the same information as the [SQLITE_VERSION], | |
| 126 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] #defines in the header, | |
| 127 ** but are associated with the library instead of the header file. Cautious | |
| 128 ** programmers might include assert() statements in their application to | |
| 129 ** verify that values returned by these interfaces match the macros in | |
| 130 ** the header, and thus insure that the application is | |
| 131 ** compiled with matching library and header files. | |
| 132 ** | |
| 133 ** <blockquote><pre> | |
| 134 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); | |
| 135 ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); | |
| 136 ** assert( strcmp(sqlite3_libversion,SQLITE_VERSION)==0 ); | |
| 137 ** </pre></blockquote> | |
| 138 ** | |
| 139 ** The sqlite3_libversion() function returns the same information as is | |
| 140 ** in the sqlite3_version[] string constant. The function is provided | |
| 141 ** for use in DLLs since DLL users usually do not have direct access to string | |
| 142 ** constants within the DLL. Similarly, the sqlite3_sourceid() function | |
| 143 ** returns the same information as is in the [SQLITE_SOURCE_ID] #define of | |
| 144 ** the header file. | |
| 145 ** | |
| 146 ** See also: [sqlite_version()] and [sqlite_source_id()]. | |
| 147 ** | |
| 148 ** Requirements: [H10021] [H10022] [H10023] | |
| 149 */ | |
| 150 SQLITE_EXTERN const char sqlite3_version[]; | |
| 151 const char *sqlite3_libversion(void); | |
| 152 const char *sqlite3_sourceid(void); | |
| 153 int sqlite3_libversion_number(void); | |
| 154 | |
| 155 /* | |
| 156 ** CAPI3REF: Test To See If The Library Is Threadsafe {H10100} <S60100> | |
| 157 ** | |
| 158 ** SQLite can be compiled with or without mutexes. When | |
| 159 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes | |
| 160 ** are enabled and SQLite is threadsafe. When the | |
| 161 ** [SQLITE_THREADSAFE] macro is 0, | |
| 162 ** the mutexes are omitted. Without the mutexes, it is not safe | |
| 163 ** to use SQLite concurrently from more than one thread. | |
| 164 ** | |
| 165 ** Enabling mutexes incurs a measurable performance penalty. | |
| 166 ** So if speed is of utmost importance, it makes sense to disable | |
| 167 ** the mutexes. But for maximum safety, mutexes should be enabled. | |
| 168 ** The default behavior is for mutexes to be enabled. | |
| 169 ** | |
| 170 ** This interface can be used by an application to make sure that the | |
| 171 ** version of SQLite that it is linking against was compiled with | |
| 172 ** the desired setting of the [SQLITE_THREADSAFE] macro. | |
| 173 ** | |
| 174 ** This interface only reports on the compile-time mutex setting | |
| 175 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with | |
| 176 ** SQLITE_THREADSAFE=1 then mutexes are enabled by default but | |
| 177 ** can be fully or partially disabled using a call to [sqlite3_config()] | |
| 178 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], | |
| 179 ** or [SQLITE_CONFIG_MUTEX]. The return value of this function shows | |
| 180 ** only the default compile-time setting, not any run-time changes | |
| 181 ** to that setting. | |
| 182 ** | |
| 183 ** See the [threading mode] documentation for additional information. | |
| 184 ** | |
| 185 ** Requirements: [H10101] [H10102] | |
| 186 */ | |
| 187 int sqlite3_threadsafe(void); | |
| 188 | |
| 189 /* | |
| 190 ** CAPI3REF: Database Connection Handle {H12000} <S40200> | |
| 191 ** KEYWORDS: {database connection} {database connections} | |
| 192 ** | |
| 193 ** Each open SQLite database is represented by a pointer to an instance of | |
| 194 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 | |
| 195 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and | |
| 196 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] | |
| 197 ** is its destructor. There are many other interfaces (such as | |
| 198 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and | |
| 199 ** [sqlite3_busy_timeout()] to name but three) that are methods on an | |
| 200 ** sqlite3 object. | |
| 201 */ | |
| 202 typedef struct sqlite3 sqlite3; | |
| 203 | |
| 204 /* | |
| 205 ** CAPI3REF: 64-Bit Integer Types {H10200} <S10110> | |
| 206 ** KEYWORDS: sqlite_int64 sqlite_uint64 | |
| 207 ** | |
| 208 ** Because there is no cross-platform way to specify 64-bit integer types | |
| 209 ** SQLite includes typedefs for 64-bit signed and unsigned integers. | |
| 210 ** | |
| 211 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. | |
| 212 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards | |
| 213 ** compatibility only. | |
| 214 ** | |
| 215 ** Requirements: [H10201] [H10202] | |
| 216 */ | |
| 217 #ifdef SQLITE_INT64_TYPE | |
| 218 typedef SQLITE_INT64_TYPE sqlite_int64; | |
| 219 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; | |
| 220 #elif defined(_MSC_VER) || defined(__BORLANDC__) | |
| 221 typedef __int64 sqlite_int64; | |
| 222 typedef unsigned __int64 sqlite_uint64; | |
| 223 #else | |
| 224 typedef long long int sqlite_int64; | |
| 225 typedef unsigned long long int sqlite_uint64; | |
| 226 #endif | |
| 227 typedef sqlite_int64 sqlite3_int64; | |
| 228 typedef sqlite_uint64 sqlite3_uint64; | |
| 229 | |
| 230 /* | |
| 231 ** If compiling for a processor that lacks floating point support, | |
| 232 ** substitute integer for floating-point. | |
| 233 */ | |
| 234 #ifdef SQLITE_OMIT_FLOATING_POINT | |
| 235 # define double sqlite3_int64 | |
| 236 #endif | |
| 237 | |
| 238 /* | |
| 239 ** CAPI3REF: Closing A Database Connection {H12010} <S30100><S40200> | |
| 240 ** | |
| 241 ** This routine is the destructor for the [sqlite3] object. | |
| 242 ** | |
| 243 ** Applications should [sqlite3_finalize | finalize] all [prepared statements] | |
| 244 ** and [sqlite3_blob_close | close] all [BLOB handles] associated with | |
| 245 ** the [sqlite3] object prior to attempting to close the object. | |
| 246 ** The [sqlite3_next_stmt()] interface can be used to locate all | |
| 247 ** [prepared statements] associated with a [database connection] if desired. | |
| 248 ** Typical code might look like this: | |
| 249 ** | |
| 250 ** <blockquote><pre> | |
| 251 ** sqlite3_stmt *pStmt; | |
| 252 ** while( (pStmt = sqlite3_next_stmt(db, 0))!=0 ){ | |
| 253 ** sqlite3_finalize(pStmt); | |
| 254 ** } | |
| 255 ** </pre></blockquote> | |
| 256 ** | |
| 257 ** If [sqlite3_close()] is invoked while a transaction is open, | |
| 258 ** the transaction is automatically rolled back. | |
| 259 ** | |
| 260 ** The C parameter to [sqlite3_close(C)] must be either a NULL | |
| 261 ** pointer or an [sqlite3] object pointer obtained | |
| 262 ** from [sqlite3_open()], [sqlite3_open16()], or | |
| 263 ** [sqlite3_open_v2()], and not previously closed. | |
| 264 ** | |
| 265 ** Requirements: | |
| 266 ** [H12011] [H12012] [H12013] [H12014] [H12015] [H12019] | |
| 267 */ | |
| 268 int sqlite3_close(sqlite3 *); | |
| 269 | |
| 270 /* | |
| 271 ** The type for a callback function. | |
| 272 ** This is legacy and deprecated. It is included for historical | |
| 273 ** compatibility and is not documented. | |
| 274 */ | |
| 275 typedef int (*sqlite3_callback)(void*,int,char**, char**); | |
| 276 | |
| 277 /* | |
| 278 ** CAPI3REF: One-Step Query Execution Interface {H12100} <S10000> | |
| 279 ** | |
| 280 ** The sqlite3_exec() interface is a convenient way of running one or more | |
| 281 ** SQL statements without having to write a lot of C code. The UTF-8 encoded | |
| 282 ** SQL statements are passed in as the second parameter to sqlite3_exec(). | |
| 283 ** The statements are evaluated one by one until either an error or | |
| 284 ** an interrupt is encountered, or until they are all done. The 3rd parameter | |
| 285 ** is an optional callback that is invoked once for each row of any query | |
| 286 ** results produced by the SQL statements. The 5th parameter tells where | |
| 287 ** to write any error messages. | |
| 288 ** | |
| 289 ** The error message passed back through the 5th parameter is held | |
| 290 ** in memory obtained from [sqlite3_malloc()]. To avoid a memory leak, | |
| 291 ** the calling application should call [sqlite3_free()] on any error | |
| 292 ** message returned through the 5th parameter when it has finished using | |
| 293 ** the error message. | |
| 294 ** | |
| 295 ** If the SQL statement in the 2nd parameter is NULL or an empty string | |
| 296 ** or a string containing only whitespace and comments, then no SQL | |
| 297 ** statements are evaluated and the database is not changed. | |
| 298 ** | |
| 299 ** The sqlite3_exec() interface is implemented in terms of | |
| 300 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()]. | |
| 301 ** The sqlite3_exec() routine does nothing to the database that cannot be done | |
| 302 ** by [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()]. | |
| 303 ** | |
| 304 ** The first parameter to [sqlite3_exec()] must be an valid and open | |
| 305 ** [database connection]. | |
| 306 ** | |
| 307 ** The database connection must not be closed while | |
| 308 ** [sqlite3_exec()] is running. | |
| 309 ** | |
| 310 ** The calling function should use [sqlite3_free()] to free | |
| 311 ** the memory that *errmsg is left pointing at once the error | |
| 312 ** message is no longer needed. | |
| 313 ** | |
| 314 ** The SQL statement text in the 2nd parameter to [sqlite3_exec()] | |
| 315 ** must remain unchanged while [sqlite3_exec()] is running. | |
| 316 ** | |
| 317 ** Requirements: | |
| 318 ** [H12101] [H12102] [H12104] [H12105] [H12107] [H12110] [H12113] [H12116] | |
| 319 ** [H12119] [H12122] [H12125] [H12131] [H12134] [H12137] [H12138] | |
| 320 */ | |
| 321 int sqlite3_exec( | |
| 322 sqlite3*, /* An open database */ | |
| 323 const char *sql, /* SQL to be evaluated */ | |
| 324 int (*callback)(void*,int,char**,char**), /* Callback function */ | |
| 325 void *, /* 1st argument to callback */ | |
| 326 char **errmsg /* Error msg written here */ | |
| 327 ); | |
| 328 | |
| 329 /* | |
| 330 ** CAPI3REF: Result Codes {H10210} <S10700> | |
| 331 ** KEYWORDS: SQLITE_OK {error code} {error codes} | |
| 332 ** KEYWORDS: {result code} {result codes} | |
| 333 ** | |
| 334 ** Many SQLite functions return an integer result code from the set shown | |
| 335 ** here in order to indicates success or failure. | |
| 336 ** | |
| 337 ** New error codes may be added in future versions of SQLite. | |
| 338 ** | |
| 339 ** See also: [SQLITE_IOERR_READ | extended result codes] | |
| 340 */ | |
| 341 #define SQLITE_OK 0 /* Successful result */ | |
| 342 /* beginning-of-error-codes */ | |
| 343 #define SQLITE_ERROR 1 /* SQL error or missing database */ | |
| 344 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ | |
| 345 #define SQLITE_PERM 3 /* Access permission denied */ | |
| 346 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ | |
| 347 #define SQLITE_BUSY 5 /* The database file is locked */ | |
| 348 #define SQLITE_LOCKED 6 /* A table in the database is locked */ | |
| 349 #define SQLITE_NOMEM 7 /* A malloc() failed */ | |
| 350 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ | |
| 351 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ | |
| 352 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ | |
| 353 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ | |
| 354 #define SQLITE_NOTFOUND 12 /* NOT USED. Table or record not found */ | |
| 355 #define SQLITE_FULL 13 /* Insertion failed because database is full */ | |
| 356 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ | |
| 357 #define SQLITE_PROTOCOL 15 /* NOT USED. Database lock protocol error */ | |
| 358 #define SQLITE_EMPTY 16 /* Database is empty */ | |
| 359 #define SQLITE_SCHEMA 17 /* The database schema changed */ | |
| 360 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ | |
| 361 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ | |
| 362 #define SQLITE_MISMATCH 20 /* Data type mismatch */ | |
| 363 #define SQLITE_MISUSE 21 /* Library used incorrectly */ | |
| 364 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ | |
| 365 #define SQLITE_AUTH 23 /* Authorization denied */ | |
| 366 #define SQLITE_FORMAT 24 /* Auxiliary database format error */ | |
| 367 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ | |
| 368 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ | |
| 369 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ | |
| 370 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ | |
| 371 /* end-of-error-codes */ | |
| 372 | |
| 373 /* | |
| 374 ** CAPI3REF: Extended Result Codes {H10220} <S10700> | |
| 375 ** KEYWORDS: {extended error code} {extended error codes} | |
| 376 ** KEYWORDS: {extended result code} {extended result codes} | |
| 377 ** | |
| 378 ** In its default configuration, SQLite API routines return one of 26 integer | |
| 379 ** [SQLITE_OK | result codes]. However, experience has shown that many of | |
| 380 ** these result codes are too coarse-grained. They do not provide as | |
| 381 ** much information about problems as programmers might like. In an effort to | |
| 382 ** address this, newer versions of SQLite (version 3.3.8 and later) include | |
| 383 ** support for additional result codes that provide more detailed information | |
| 384 ** about errors. The extended result codes are enabled or disabled | |
| 385 ** on a per database connection basis using the | |
| 386 ** [sqlite3_extended_result_codes()] API. | |
| 387 ** | |
| 388 ** Some of the available extended result codes are listed here. | |
| 389 ** One may expect the number of extended result codes will be expand | |
| 390 ** over time. Software that uses extended result codes should expect | |
| 391 ** to see new result codes in future releases of SQLite. | |
| 392 ** | |
| 393 ** The SQLITE_OK result code will never be extended. It will always | |
| 394 ** be exactly zero. | |
| 395 */ | |
| 396 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) | |
| 397 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) | |
| 398 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) | |
| 399 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) | |
| 400 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) | |
| 401 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) | |
| 402 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) | |
| 403 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) | |
| 404 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) | |
| 405 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) | |
| 406 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) | |
| 407 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) | |
| 408 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) | |
| 409 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) | |
| 410 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) | |
| 411 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) | |
| 412 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) | |
| 413 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8) ) | |
| 414 | |
| 415 /* | |
| 416 ** CAPI3REF: Flags For File Open Operations {H10230} <H11120> <H12700> | |
| 417 ** | |
| 418 ** These bit values are intended for use in the | |
| 419 ** 3rd parameter to the [sqlite3_open_v2()] interface and | |
| 420 ** in the 4th parameter to the xOpen method of the | |
| 421 ** [sqlite3_vfs] object. | |
| 422 */ | |
| 423 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ | |
| 424 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ | |
| 425 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ | |
| 426 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ | |
| 427 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ | |
| 428 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ | |
| 429 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ | |
| 430 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ | |
| 431 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ | |
| 432 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ | |
| 433 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ | |
| 434 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ | |
| 435 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ | |
| 436 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ | |
| 437 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ | |
| 438 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ | |
| 439 | |
| 440 /* | |
| 441 ** CAPI3REF: Device Characteristics {H10240} <H11120> | |
| 442 ** | |
| 443 ** The xDeviceCapabilities method of the [sqlite3_io_methods] | |
| 444 ** object returns an integer which is a vector of the these | |
| 445 ** bit values expressing I/O characteristics of the mass storage | |
| 446 ** device that holds the file that the [sqlite3_io_methods] | |
| 447 ** refers to. | |
| 448 ** | |
| 449 ** The SQLITE_IOCAP_ATOMIC property means that all writes of | |
| 450 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values | |
| 451 ** mean that writes of blocks that are nnn bytes in size and | |
| 452 ** are aligned to an address which is an integer multiple of | |
| 453 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means | |
| 454 ** that when data is appended to a file, the data is appended | |
| 455 ** first then the size of the file is extended, never the other | |
| 456 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that | |
| 457 ** information is written to disk in the same order as calls | |
| 458 ** to xWrite(). | |
| 459 */ | |
| 460 #define SQLITE_IOCAP_ATOMIC 0x00000001 | |
| 461 #define SQLITE_IOCAP_ATOMIC512 0x00000002 | |
| 462 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 | |
| 463 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 | |
| 464 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 | |
| 465 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 | |
| 466 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 | |
| 467 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 | |
| 468 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 | |
| 469 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 | |
| 470 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 | |
| 471 | |
| 472 /* | |
| 473 ** CAPI3REF: File Locking Levels {H10250} <H11120> <H11310> | |
| 474 ** | |
| 475 ** SQLite uses one of these integer values as the second | |
| 476 ** argument to calls it makes to the xLock() and xUnlock() methods | |
| 477 ** of an [sqlite3_io_methods] object. | |
| 478 */ | |
| 479 #define SQLITE_LOCK_NONE 0 | |
| 480 #define SQLITE_LOCK_SHARED 1 | |
| 481 #define SQLITE_LOCK_RESERVED 2 | |
| 482 #define SQLITE_LOCK_PENDING 3 | |
| 483 #define SQLITE_LOCK_EXCLUSIVE 4 | |
| 484 | |
| 485 /* | |
| 486 ** CAPI3REF: Synchronization Type Flags {H10260} <H11120> | |
| 487 ** | |
| 488 ** When SQLite invokes the xSync() method of an | |
| 489 ** [sqlite3_io_methods] object it uses a combination of | |
| 490 ** these integer values as the second argument. | |
| 491 ** | |
| 492 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the | |
| 493 ** sync operation only needs to flush data to mass storage. Inode | |
| 494 ** information need not be flushed. If the lower four bits of the flag | |
| 495 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. | |
| 496 ** If the lower four bits equal SQLITE_SYNC_FULL, that means | |
| 497 ** to use Mac OS X style fullsync instead of fsync(). | |
| 498 */ | |
| 499 #define SQLITE_SYNC_NORMAL 0x00002 | |
| 500 #define SQLITE_SYNC_FULL 0x00003 | |
| 501 #define SQLITE_SYNC_DATAONLY 0x00010 | |
| 502 | |
| 503 /* | |
| 504 ** CAPI3REF: OS Interface Open File Handle {H11110} <S20110> | |
| 505 ** | |
| 506 ** An [sqlite3_file] object represents an open file in the | |
| 507 ** [sqlite3_vfs | OS interface layer]. Individual OS interface | |
| 508 ** implementations will | |
| 509 ** want to subclass this object by appending additional fields | |
| 510 ** for their own use. The pMethods entry is a pointer to an | |
| 511 ** [sqlite3_io_methods] object that defines methods for performing | |
| 512 ** I/O operations on the open file. | |
| 513 */ | |
| 514 typedef struct sqlite3_file sqlite3_file; | |
| 515 struct sqlite3_file { | |
| 516 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ | |
| 517 }; | |
| 518 | |
| 519 /* | |
| 520 ** CAPI3REF: OS Interface File Virtual Methods Object {H11120} <S20110> | |
| 521 ** | |
| 522 ** Every file opened by the [sqlite3_vfs] xOpen method populates an | |
| 523 ** [sqlite3_file] object (or, more commonly, a subclass of the | |
| 524 ** [sqlite3_file] object) with a pointer to an instance of this object. | |
| 525 ** This object defines the methods used to perform various operations | |
| 526 ** against the open file represented by the [sqlite3_file] object. | |
| 527 ** | |
| 528 ** If the xOpen method sets the sqlite3_file.pMethods element | |
| 529 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method | |
| 530 ** may be invoked even if the xOpen reported that it failed. The | |
| 531 ** only way to prevent a call to xClose following a failed xOpen | |
| 532 ** is for the xOpen to set the sqlite3_file.pMethods element to NULL. | |
| 533 ** | |
| 534 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or | |
| 535 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). | |
| 536 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] | |
| 537 ** flag may be ORed in to indicate that only the data of the file | |
| 538 ** and not its inode needs to be synced. | |
| 539 ** | |
| 540 ** The integer values to xLock() and xUnlock() are one of | |
| 541 ** <ul> | |
| 542 ** <li> [SQLITE_LOCK_NONE], | |
| 543 ** <li> [SQLITE_LOCK_SHARED], | |
| 544 ** <li> [SQLITE_LOCK_RESERVED], | |
| 545 ** <li> [SQLITE_LOCK_PENDING], or | |
| 546 ** <li> [SQLITE_LOCK_EXCLUSIVE]. | |
| 547 ** </ul> | |
| 548 ** xLock() increases the lock. xUnlock() decreases the lock. | |
| 549 ** The xCheckReservedLock() method checks whether any database connection, | |
| 550 ** either in this process or in some other process, is holding a RESERVED, | |
| 551 ** PENDING, or EXCLUSIVE lock on the file. It returns true | |
| 552 ** if such a lock exists and false otherwise. | |
| 553 ** | |
| 554 ** The xFileControl() method is a generic interface that allows custom | |
| 555 ** VFS implementations to directly control an open file using the | |
| 556 ** [sqlite3_file_control()] interface. The second "op" argument is an | |
| 557 ** integer opcode. The third argument is a generic pointer intended to | |
| 558 ** point to a structure that may contain arguments or space in which to | |
| 559 ** write return values. Potential uses for xFileControl() might be | |
| 560 ** functions to enable blocking locks with timeouts, to change the | |
| 561 ** locking strategy (for example to use dot-file locks), to inquire | |
| 562 ** about the status of a lock, or to break stale locks. The SQLite | |
| 563 ** core reserves all opcodes less than 100 for its own use. | |
| 564 ** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. | |
| 565 ** Applications that define a custom xFileControl method should use opcodes | |
| 566 ** greater than 100 to avoid conflicts. | |
| 567 ** | |
| 568 ** The xSectorSize() method returns the sector size of the | |
| 569 ** device that underlies the file. The sector size is the | |
| 570 ** minimum write that can be performed without disturbing | |
| 571 ** other bytes in the file. The xDeviceCharacteristics() | |
| 572 ** method returns a bit vector describing behaviors of the | |
| 573 ** underlying device: | |
| 574 ** | |
| 575 ** <ul> | |
| 576 ** <li> [SQLITE_IOCAP_ATOMIC] | |
| 577 ** <li> [SQLITE_IOCAP_ATOMIC512] | |
| 578 ** <li> [SQLITE_IOCAP_ATOMIC1K] | |
| 579 ** <li> [SQLITE_IOCAP_ATOMIC2K] | |
| 580 ** <li> [SQLITE_IOCAP_ATOMIC4K] | |
| 581 ** <li> [SQLITE_IOCAP_ATOMIC8K] | |
| 582 ** <li> [SQLITE_IOCAP_ATOMIC16K] | |
| 583 ** <li> [SQLITE_IOCAP_ATOMIC32K] | |
| 584 ** <li> [SQLITE_IOCAP_ATOMIC64K] | |
| 585 ** <li> [SQLITE_IOCAP_SAFE_APPEND] | |
| 586 ** <li> [SQLITE_IOCAP_SEQUENTIAL] | |
| 587 ** </ul> | |
| 588 ** | |
| 589 ** The SQLITE_IOCAP_ATOMIC property means that all writes of | |
| 590 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values | |
| 591 ** mean that writes of blocks that are nnn bytes in size and | |
| 592 ** are aligned to an address which is an integer multiple of | |
| 593 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means | |
| 594 ** that when data is appended to a file, the data is appended | |
| 595 ** first then the size of the file is extended, never the other | |
| 596 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that | |
| 597 ** information is written to disk in the same order as calls | |
| 598 ** to xWrite(). | |
| 599 ** | |
| 600 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill | |
| 601 ** in the unread portions of the buffer with zeros. A VFS that | |
| 602 ** fails to zero-fill short reads might seem to work. However, | |
| 603 ** failure to zero-fill short reads will eventually lead to | |
| 604 ** database corruption. | |
| 605 */ | |
| 606 typedef struct sqlite3_io_methods sqlite3_io_methods; | |
| 607 struct sqlite3_io_methods { | |
| 608 int iVersion; | |
| 609 int (*xClose)(sqlite3_file*); | |
| 610 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); | |
| 611 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); | |
| 612 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); | |
| 613 int (*xSync)(sqlite3_file*, int flags); | |
| 614 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); | |
| 615 int (*xLock)(sqlite3_file*, int); | |
| 616 int (*xUnlock)(sqlite3_file*, int); | |
| 617 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); | |
| 618 int (*xFileControl)(sqlite3_file*, int op, void *pArg); | |
| 619 int (*xSectorSize)(sqlite3_file*); | |
| 620 int (*xDeviceCharacteristics)(sqlite3_file*); | |
| 621 /* Additional methods may be added in future releases */ | |
| 622 }; | |
| 623 | |
| 624 /* | |
| 625 ** CAPI3REF: Standard File Control Opcodes {H11310} <S30800> | |
| 626 ** | |
| 627 ** These integer constants are opcodes for the xFileControl method | |
| 628 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] | |
| 629 ** interface. | |
| 630 ** | |
| 631 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This | |
| 632 ** opcode causes the xFileControl method to write the current state of | |
| 633 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], | |
| 634 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) | |
| 635 ** into an integer that the pArg argument points to. This capability | |
| 636 ** is used during testing and only needs to be supported when SQLITE_TEST | |
| 637 ** is defined. | |
| 638 */ | |
| 639 #define SQLITE_FCNTL_LOCKSTATE 1 | |
| 640 #define SQLITE_GET_LOCKPROXYFILE 2 | |
| 641 #define SQLITE_SET_LOCKPROXYFILE 3 | |
| 642 #define SQLITE_LAST_ERRNO 4 | |
| 643 | |
| 644 /* | |
| 645 ** CAPI3REF: Mutex Handle {H17110} <S20130> | |
| 646 ** | |
| 647 ** The mutex module within SQLite defines [sqlite3_mutex] to be an | |
| 648 ** abstract type for a mutex object. The SQLite core never looks | |
| 649 ** at the internal representation of an [sqlite3_mutex]. It only | |
| 650 ** deals with pointers to the [sqlite3_mutex] object. | |
| 651 ** | |
| 652 ** Mutexes are created using [sqlite3_mutex_alloc()]. | |
| 653 */ | |
| 654 typedef struct sqlite3_mutex sqlite3_mutex; | |
| 655 | |
| 656 /* | |
| 657 ** CAPI3REF: OS Interface Object {H11140} <S20100> | |
| 658 ** | |
| 659 ** An instance of the sqlite3_vfs object defines the interface between | |
| 660 ** the SQLite core and the underlying operating system. The "vfs" | |
| 661 ** in the name of the object stands for "virtual file system". | |
| 662 ** | |
| 663 ** The value of the iVersion field is initially 1 but may be larger in | |
| 664 ** future versions of SQLite. Additional fields may be appended to this | |
| 665 ** object when the iVersion value is increased. Note that the structure | |
| 666 ** of the sqlite3_vfs object changes in the transaction between | |
| 667 ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not | |
| 668 ** modified. | |
| 669 ** | |
| 670 ** The szOsFile field is the size of the subclassed [sqlite3_file] | |
| 671 ** structure used by this VFS. mxPathname is the maximum length of | |
| 672 ** a pathname in this VFS. | |
| 673 ** | |
| 674 ** Registered sqlite3_vfs objects are kept on a linked list formed by | |
| 675 ** the pNext pointer. The [sqlite3_vfs_register()] | |
| 676 ** and [sqlite3_vfs_unregister()] interfaces manage this list | |
| 677 ** in a thread-safe way. The [sqlite3_vfs_find()] interface | |
| 678 ** searches the list. Neither the application code nor the VFS | |
| 679 ** implementation should use the pNext pointer. | |
| 680 ** | |
| 681 ** The pNext field is the only field in the sqlite3_vfs | |
| 682 ** structure that SQLite will ever modify. SQLite will only access | |
| 683 ** or modify this field while holding a particular static mutex. | |
| 684 ** The application should never modify anything within the sqlite3_vfs | |
| 685 ** object once the object has been registered. | |
| 686 ** | |
| 687 ** The zName field holds the name of the VFS module. The name must | |
| 688 ** be unique across all VFS modules. | |
| 689 ** | |
| 690 ** SQLite will guarantee that the zFilename parameter to xOpen | |
| 691 ** is either a NULL pointer or string obtained | |
| 692 ** from xFullPathname(). SQLite further guarantees that | |
| 693 ** the string will be valid and unchanged until xClose() is | |
| 694 ** called. Because of the previous sentence, | |
| 695 ** the [sqlite3_file] can safely store a pointer to the | |
| 696 ** filename if it needs to remember the filename for some reason. | |
| 697 ** If the zFilename parameter is xOpen is a NULL pointer then xOpen | |
| 698 ** must invent its own temporary name for the file. Whenever the | |
| 699 ** xFilename parameter is NULL it will also be the case that the | |
| 700 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. | |
| 701 ** | |
| 702 ** The flags argument to xOpen() includes all bits set in | |
| 703 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] | |
| 704 ** or [sqlite3_open16()] is used, then flags includes at least | |
| 705 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. | |
| 706 ** If xOpen() opens a file read-only then it sets *pOutFlags to | |
| 707 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. | |
| 708 ** | |
| 709 ** SQLite will also add one of the following flags to the xOpen() | |
| 710 ** call, depending on the object being opened: | |
| 711 ** | |
| 712 ** <ul> | |
| 713 ** <li> [SQLITE_OPEN_MAIN_DB] | |
| 714 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] | |
| 715 ** <li> [SQLITE_OPEN_TEMP_DB] | |
| 716 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] | |
| 717 ** <li> [SQLITE_OPEN_TRANSIENT_DB] | |
| 718 ** <li> [SQLITE_OPEN_SUBJOURNAL] | |
| 719 ** <li> [SQLITE_OPEN_MASTER_JOURNAL] | |
| 720 ** </ul> | |
| 721 ** | |
| 722 ** The file I/O implementation can use the object type flags to | |
| 723 ** change the way it deals with files. For example, an application | |
| 724 ** that does not care about crash recovery or rollback might make | |
| 725 ** the open of a journal file a no-op. Writes to this journal would | |
| 726 ** also be no-ops, and any attempt to read the journal would return | |
| 727 ** SQLITE_IOERR. Or the implementation might recognize that a database | |
| 728 ** file will be doing page-aligned sector reads and writes in a random | |
| 729 ** order and set up its I/O subsystem accordingly. | |
| 730 ** | |
| 731 ** SQLite might also add one of the following flags to the xOpen method: | |
| 732 ** | |
| 733 ** <ul> | |
| 734 ** <li> [SQLITE_OPEN_DELETEONCLOSE] | |
| 735 ** <li> [SQLITE_OPEN_EXCLUSIVE] | |
| 736 ** </ul> | |
| 737 ** | |
| 738 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be | |
| 739 ** deleted when it is closed. The [SQLITE_OPEN_DELETEONCLOSE] | |
| 740 ** will be set for TEMP databases, journals and for subjournals. | |
| 741 ** | |
| 742 ** The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction | |
| 743 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly | |
| 744 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() | |
| 745 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the | |
| 746 ** SQLITE_OPEN_CREATE, is used to indicate that file should always | |
| 747 ** be created, and that it is an error if it already exists. | |
| 748 ** It is <i>not</i> used to indicate the file should be opened | |
| 749 ** for exclusive access. | |
| 750 ** | |
| 751 ** At least szOsFile bytes of memory are allocated by SQLite | |
| 752 ** to hold the [sqlite3_file] structure passed as the third | |
| 753 ** argument to xOpen. The xOpen method does not have to | |
| 754 ** allocate the structure; it should just fill it in. Note that | |
| 755 ** the xOpen method must set the sqlite3_file.pMethods to either | |
| 756 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do | |
| 757 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods | |
| 758 ** element will be valid after xOpen returns regardless of the success | |
| 759 ** or failure of the xOpen call. | |
| 760 ** | |
| 761 ** The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] | |
| 762 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to | |
| 763 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] | |
| 764 ** to test whether a file is at least readable. The file can be a | |
| 765 ** directory. | |
| 766 ** | |
| 767 ** SQLite will always allocate at least mxPathname+1 bytes for the | |
| 768 ** output buffer xFullPathname. The exact size of the output buffer | |
| 769 ** is also passed as a parameter to both methods. If the output buffer | |
| 770 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is | |
| 771 ** handled as a fatal error by SQLite, vfs implementations should endeavor | |
| 772 ** to prevent this by setting mxPathname to a sufficiently large value. | |
| 773 ** | |
| 774 ** The xRandomness(), xSleep(), and xCurrentTime() interfaces | |
| 775 ** are not strictly a part of the filesystem, but they are | |
| 776 ** included in the VFS structure for completeness. | |
| 777 ** The xRandomness() function attempts to return nBytes bytes | |
| 778 ** of good-quality randomness into zOut. The return value is | |
| 779 ** the actual number of bytes of randomness obtained. | |
| 780 ** The xSleep() method causes the calling thread to sleep for at | |
| 781 ** least the number of microseconds given. The xCurrentTime() | |
| 782 ** method returns a Julian Day Number for the current date and time. | |
| 783 ** | |
| 784 */ | |
| 785 typedef struct sqlite3_vfs sqlite3_vfs; | |
| 786 struct sqlite3_vfs { | |
| 787 int iVersion; /* Structure version number */ | |
| 788 int szOsFile; /* Size of subclassed sqlite3_file */ | |
| 789 int mxPathname; /* Maximum file pathname length */ | |
| 790 sqlite3_vfs *pNext; /* Next registered VFS */ | |
| 791 const char *zName; /* Name of this virtual file system */ | |
| 792 void *pAppData; /* Pointer to application-specific data */ | |
| 793 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, | |
| 794 int flags, int *pOutFlags); | |
| 795 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); | |
| 796 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); | |
| 797 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); | |
| 798 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); | |
| 799 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); | |
| 800 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); | |
| 801 void (*xDlClose)(sqlite3_vfs*, void*); | |
| 802 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); | |
| 803 int (*xSleep)(sqlite3_vfs*, int microseconds); | |
| 804 int (*xCurrentTime)(sqlite3_vfs*, double*); | |
| 805 int (*xGetLastError)(sqlite3_vfs*, int, char *); | |
| 806 /* New fields may be appended in figure versions. The iVersion | |
| 807 ** value will increment whenever this happens. */ | |
| 808 }; | |
| 809 | |
| 810 /* | |
| 811 ** CAPI3REF: Flags for the xAccess VFS method {H11190} <H11140> | |
| 812 ** | |
| 813 ** These integer constants can be used as the third parameter to | |
| 814 ** the xAccess method of an [sqlite3_vfs] object. {END} They determine | |
| 815 ** what kind of permissions the xAccess method is looking for. | |
| 816 ** With SQLITE_ACCESS_EXISTS, the xAccess method | |
| 817 ** simply checks whether the file exists. | |
| 818 ** With SQLITE_ACCESS_READWRITE, the xAccess method | |
| 819 ** checks whether the file is both readable and writable. | |
| 820 ** With SQLITE_ACCESS_READ, the xAccess method | |
| 821 ** checks whether the file is readable. | |
| 822 */ | |
| 823 #define SQLITE_ACCESS_EXISTS 0 | |
| 824 #define SQLITE_ACCESS_READWRITE 1 | |
| 825 #define SQLITE_ACCESS_READ 2 | |
| 826 | |
| 827 /* | |
| 828 ** CAPI3REF: Initialize The SQLite Library {H10130} <S20000><S30100> | |
| 829 ** | |
| 830 ** The sqlite3_initialize() routine initializes the | |
| 831 ** SQLite library. The sqlite3_shutdown() routine | |
| 832 ** deallocates any resources that were allocated by sqlite3_initialize(). | |
| 833 ** | |
| 834 ** A call to sqlite3_initialize() is an "effective" call if it is | |
| 835 ** the first time sqlite3_initialize() is invoked during the lifetime of | |
| 836 ** the process, or if it is the first time sqlite3_initialize() is invoked | |
| 837 ** following a call to sqlite3_shutdown(). Only an effective call | |
| 838 ** of sqlite3_initialize() does any initialization. All other calls | |
| 839 ** are harmless no-ops. | |
| 840 ** | |
| 841 ** A call to sqlite3_shutdown() is an "effective" call if it is the first | |
| 842 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). Only | |
| 843 ** an effective call to sqlite3_shutdown() does any deinitialization. | |
| 844 ** All other calls to sqlite3_shutdown() are harmless no-ops. | |
| 845 ** | |
| 846 ** Among other things, sqlite3_initialize() shall invoke | |
| 847 ** sqlite3_os_init(). Similarly, sqlite3_shutdown() | |
| 848 ** shall invoke sqlite3_os_end(). | |
| 849 ** | |
| 850 ** The sqlite3_initialize() routine returns [SQLITE_OK] on success. | |
| 851 ** If for some reason, sqlite3_initialize() is unable to initialize | |
| 852 ** the library (perhaps it is unable to allocate a needed resource such | |
| 853 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. | |
| 854 ** | |
| 855 ** The sqlite3_initialize() routine is called internally by many other | |
| 856 ** SQLite interfaces so that an application usually does not need to | |
| 857 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] | |
| 858 ** calls sqlite3_initialize() so the SQLite library will be automatically | |
| 859 ** initialized when [sqlite3_open()] is called if it has not be initialized | |
| 860 ** already. However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] | |
| 861 ** compile-time option, then the automatic calls to sqlite3_initialize() | |
| 862 ** are omitted and the application must call sqlite3_initialize() directly | |
| 863 ** prior to using any other SQLite interface. For maximum portability, | |
| 864 ** it is recommended that applications always invoke sqlite3_initialize() | |
| 865 ** directly prior to using any other SQLite interface. Future releases | |
| 866 ** of SQLite may require this. In other words, the behavior exhibited | |
| 867 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the | |
| 868 ** default behavior in some future release of SQLite. | |
| 869 ** | |
| 870 ** The sqlite3_os_init() routine does operating-system specific | |
| 871 ** initialization of the SQLite library. The sqlite3_os_end() | |
| 872 ** routine undoes the effect of sqlite3_os_init(). Typical tasks | |
| 873 ** performed by these routines include allocation or deallocation | |
| 874 ** of static resources, initialization of global variables, | |
| 875 ** setting up a default [sqlite3_vfs] module, or setting up | |
| 876 ** a default configuration using [sqlite3_config()]. | |
| 877 ** | |
| 878 ** The application should never invoke either sqlite3_os_init() | |
| 879 ** or sqlite3_os_end() directly. The application should only invoke | |
| 880 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() | |
| 881 ** interface is called automatically by sqlite3_initialize() and | |
| 882 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate | |
| 883 ** implementations for sqlite3_os_init() and sqlite3_os_end() | |
| 884 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. | |
| 885 ** When [custom builds | built for other platforms] | |
| 886 ** (using the [SQLITE_OS_OTHER=1] compile-time | |
| 887 ** option) the application must supply a suitable implementation for | |
| 888 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied | |
| 889 ** implementation of sqlite3_os_init() or sqlite3_os_end() | |
| 890 ** must return [SQLITE_OK] on success and some other [error code] upon | |
| 891 ** failure. | |
| 892 */ | |
| 893 int sqlite3_initialize(void); | |
| 894 int sqlite3_shutdown(void); | |
| 895 int sqlite3_os_init(void); | |
| 896 int sqlite3_os_end(void); | |
| 897 | |
| 898 /* | |
| 899 ** CAPI3REF: Configuring The SQLite Library {H14100} <S20000><S30200> | |
| 900 ** EXPERIMENTAL | |
| 901 ** | |
| 902 ** The sqlite3_config() interface is used to make global configuration | |
| 903 ** changes to SQLite in order to tune SQLite to the specific needs of | |
| 904 ** the application. The default configuration is recommended for most | |
| 905 ** applications and so this routine is usually not necessary. It is | |
| 906 ** provided to support rare applications with unusual needs. | |
| 907 ** | |
| 908 ** The sqlite3_config() interface is not threadsafe. The application | |
| 909 ** must insure that no other SQLite interfaces are invoked by other | |
| 910 ** threads while sqlite3_config() is running. Furthermore, sqlite3_config() | |
| 911 ** may only be invoked prior to library initialization using | |
| 912 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. | |
| 913 ** Note, however, that sqlite3_config() can be called as part of the | |
| 914 ** implementation of an application-defined [sqlite3_os_init()]. | |
| 915 ** | |
| 916 ** The first argument to sqlite3_config() is an integer | |
| 917 ** [SQLITE_CONFIG_SINGLETHREAD | configuration option] that determines | |
| 918 ** what property of SQLite is to be configured. Subsequent arguments | |
| 919 ** vary depending on the [SQLITE_CONFIG_SINGLETHREAD | configuration option] | |
| 920 ** in the first argument. | |
| 921 ** | |
| 922 ** When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. | |
| 923 ** If the option is unknown or SQLite is unable to set the option | |
| 924 ** then this routine returns a non-zero [error code]. | |
| 925 ** | |
| 926 ** Requirements: | |
| 927 ** [H14103] [H14106] [H14120] [H14123] [H14126] [H14129] [H14132] [H14135] | |
| 928 ** [H14138] [H14141] [H14144] [H14147] [H14150] [H14153] [H14156] [H14159] | |
| 929 ** [H14162] [H14165] [H14168] | |
| 930 */ | |
| 931 SQLITE_EXPERIMENTAL int sqlite3_config(int, ...); | |
| 932 | |
| 933 /* | |
| 934 ** CAPI3REF: Configure database connections {H14200} <S20000> | |
| 935 ** EXPERIMENTAL | |
| 936 ** | |
| 937 ** The sqlite3_db_config() interface is used to make configuration | |
| 938 ** changes to a [database connection]. The interface is similar to | |
| 939 ** [sqlite3_config()] except that the changes apply to a single | |
| 940 ** [database connection] (specified in the first argument). The | |
| 941 ** sqlite3_db_config() interface can only be used immediately after | |
| 942 ** the database connection is created using [sqlite3_open()], | |
| 943 ** [sqlite3_open16()], or [sqlite3_open_v2()]. | |
| 944 ** | |
| 945 ** The second argument to sqlite3_db_config(D,V,...) is the | |
| 946 ** configuration verb - an integer code that indicates what | |
| 947 ** aspect of the [database connection] is being configured. | |
| 948 ** The only choice for this value is [SQLITE_DBCONFIG_LOOKASIDE]. | |
| 949 ** New verbs are likely to be added in future releases of SQLite. | |
| 950 ** Additional arguments depend on the verb. | |
| 951 ** | |
| 952 ** Requirements: | |
| 953 ** [H14203] [H14206] [H14209] [H14212] [H14215] | |
| 954 */ | |
| 955 SQLITE_EXPERIMENTAL int sqlite3_db_config(sqlite3*, int op, ...); | |
| 956 | |
| 957 /* | |
| 958 ** CAPI3REF: Memory Allocation Routines {H10155} <S20120> | |
| 959 ** EXPERIMENTAL | |
| 960 ** | |
| 961 ** An instance of this object defines the interface between SQLite | |
| 962 ** and low-level memory allocation routines. | |
| 963 ** | |
| 964 ** This object is used in only one place in the SQLite interface. | |
| 965 ** A pointer to an instance of this object is the argument to | |
| 966 ** [sqlite3_config()] when the configuration option is | |
| 967 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. | |
| 968 ** By creating an instance of this object | |
| 969 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) | |
| 970 ** during configuration, an application can specify an alternative | |
| 971 ** memory allocation subsystem for SQLite to use for all of its | |
| 972 ** dynamic memory needs. | |
| 973 ** | |
| 974 ** Note that SQLite comes with several [built-in memory allocators] | |
| 975 ** that are perfectly adequate for the overwhelming majority of applications | |
| 976 ** and that this object is only useful to a tiny minority of applications | |
| 977 ** with specialized memory allocation requirements. This object is | |
| 978 ** also used during testing of SQLite in order to specify an alternative | |
| 979 ** memory allocator that simulates memory out-of-memory conditions in | |
| 980 ** order to verify that SQLite recovers gracefully from such | |
| 981 ** conditions. | |
| 982 ** | |
| 983 ** The xMalloc and xFree methods must work like the | |
| 984 ** malloc() and free() functions from the standard C library. | |
| 985 ** The xRealloc method must work like realloc() from the standard C library | |
| 986 ** with the exception that if the second argument to xRealloc is zero, | |
| 987 ** xRealloc must be a no-op - it must not perform any allocation or | |
| 988 ** deallocation. SQLite guaranteeds that the second argument to | |
| 989 ** xRealloc is always a value returned by a prior call to xRoundup. | |
| 990 ** And so in cases where xRoundup always returns a positive number, | |
| 991 ** xRealloc can perform exactly as the standard library realloc() and | |
| 992 ** still be in compliance with this specification. | |
| 993 ** | |
| 994 ** xSize should return the allocated size of a memory allocation | |
| 995 ** previously obtained from xMalloc or xRealloc. The allocated size | |
| 996 ** is always at least as big as the requested size but may be larger. | |
| 997 ** | |
| 998 ** The xRoundup method returns what would be the allocated size of | |
| 999 ** a memory allocation given a particular requested size. Most memory | |
| 1000 ** allocators round up memory allocations at least to the next multiple | |
| 1001 ** of 8. Some allocators round up to a larger multiple or to a power of 2. | |
| 1002 ** Every memory allocation request coming in through [sqlite3_malloc()] | |
| 1003 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, | |
| 1004 ** that causes the corresponding memory allocation to fail. | |
| 1005 ** | |
| 1006 ** The xInit method initializes the memory allocator. (For example, | |
| 1007 ** it might allocate any require mutexes or initialize internal data | |
| 1008 ** structures. The xShutdown method is invoked (indirectly) by | |
| 1009 ** [sqlite3_shutdown()] and should deallocate any resources acquired | |
| 1010 ** by xInit. The pAppData pointer is used as the only parameter to | |
| 1011 ** xInit and xShutdown. | |
| 1012 ** | |
| 1013 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes | |
| 1014 ** the xInit method, so the xInit method need not be threadsafe. The | |
| 1015 ** xShutdown method is only called from [sqlite3_shutdown()] so it does | |
| 1016 ** not need to be threadsafe either. For all other methods, SQLite | |
| 1017 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the | |
| 1018 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which | |
| 1019 ** it is by default) and so the methods are automatically serialized. | |
| 1020 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other | |
| 1021 ** methods must be threadsafe or else make their own arrangements for | |
| 1022 ** serialization. | |
| 1023 ** | |
| 1024 ** SQLite will never invoke xInit() more than once without an intervening | |
| 1025 ** call to xShutdown(). | |
| 1026 */ | |
| 1027 typedef struct sqlite3_mem_methods sqlite3_mem_methods; | |
| 1028 struct sqlite3_mem_methods { | |
| 1029 void *(*xMalloc)(int); /* Memory allocation function */ | |
| 1030 void (*xFree)(void*); /* Free a prior allocation */ | |
| 1031 void *(*xRealloc)(void*,int); /* Resize an allocation */ | |
| 1032 int (*xSize)(void*); /* Return the size of an allocation */ | |
| 1033 int (*xRoundup)(int); /* Round up request size to allocation size */ | |
| 1034 int (*xInit)(void*); /* Initialize the memory allocator */ | |
| 1035 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ | |
| 1036 void *pAppData; /* Argument to xInit() and xShutdown() */ | |
| 1037 }; | |
| 1038 | |
| 1039 /* | |
| 1040 ** CAPI3REF: Configuration Options {H10160} <S20000> | |
| 1041 ** EXPERIMENTAL | |
| 1042 ** | |
| 1043 ** These constants are the available integer configuration options that | |
| 1044 ** can be passed as the first argument to the [sqlite3_config()] interface. | |
| 1045 ** | |
| 1046 ** New configuration options may be added in future releases of SQLite. | |
| 1047 ** Existing configuration options might be discontinued. Applications | |
| 1048 ** should check the return code from [sqlite3_config()] to make sure that | |
| 1049 ** the call worked. The [sqlite3_config()] interface will return a | |
| 1050 ** non-zero [error code] if a discontinued or unsupported configuration option | |
| 1051 ** is invoked. | |
| 1052 ** | |
| 1053 ** <dl> | |
| 1054 ** <dt>SQLITE_CONFIG_SINGLETHREAD</dt> | |
| 1055 ** <dd>There are no arguments to this option. This option disables | |
| 1056 ** all mutexing and puts SQLite into a mode where it can only be used | |
| 1057 ** by a single thread.</dd> | |
| 1058 ** | |
| 1059 ** <dt>SQLITE_CONFIG_MULTITHREAD</dt> | |
| 1060 ** <dd>There are no arguments to this option. This option disables | |
| 1061 ** mutexing on [database connection] and [prepared statement] objects. | |
| 1062 ** The application is responsible for serializing access to | |
| 1063 ** [database connections] and [prepared statements]. But other mutexes | |
| 1064 ** are enabled so that SQLite will be safe to use in a multi-threaded | |
| 1065 ** environment as long as no two threads attempt to use the same | |
| 1066 ** [database connection] at the same time. See the [threading mode] | |
| 1067 ** documentation for additional information.</dd> | |
| 1068 ** | |
| 1069 ** <dt>SQLITE_CONFIG_SERIALIZED</dt> | |
| 1070 ** <dd>There are no arguments to this option. This option enables | |
| 1071 ** all mutexes including the recursive | |
| 1072 ** mutexes on [database connection] and [prepared statement] objects. | |
| 1073 ** In this mode (which is the default when SQLite is compiled with | |
| 1074 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access | |
| 1075 ** to [database connections] and [prepared statements] so that the | |
| 1076 ** application is free to use the same [database connection] or the | |
| 1077 ** same [prepared statement] in different threads at the same time. | |
| 1078 ** See the [threading mode] documentation for additional information.</dd> | |
| 1079 ** | |
| 1080 ** <dt>SQLITE_CONFIG_MALLOC</dt> | |
| 1081 ** <dd>This option takes a single argument which is a pointer to an | |
| 1082 ** instance of the [sqlite3_mem_methods] structure. The argument specifies | |
| 1083 ** alternative low-level memory allocation routines to be used in place of | |
| 1084 ** the memory allocation routines built into SQLite.</dd> | |
| 1085 ** | |
| 1086 ** <dt>SQLITE_CONFIG_GETMALLOC</dt> | |
| 1087 ** <dd>This option takes a single argument which is a pointer to an | |
| 1088 ** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] | |
| 1089 ** structure is filled with the currently defined memory allocation routines. | |
| 1090 ** This option can be used to overload the default memory allocation | |
| 1091 ** routines with a wrapper that simulations memory allocation failure or | |
| 1092 ** tracks memory usage, for example.</dd> | |
| 1093 ** | |
| 1094 ** <dt>SQLITE_CONFIG_MEMSTATUS</dt> | |
| 1095 ** <dd>This option takes single argument of type int, interpreted as a | |
| 1096 ** boolean, which enables or disables the collection of memory allocation | |
| 1097 ** statistics. When disabled, the following SQLite interfaces become | |
| 1098 ** non-operational: | |
| 1099 ** <ul> | |
| 1100 ** <li> [sqlite3_memory_used()] | |
| 1101 ** <li> [sqlite3_memory_highwater()] | |
| 1102 ** <li> [sqlite3_soft_heap_limit()] | |
| 1103 ** <li> [sqlite3_status()] | |
| 1104 ** </ul> | |
| 1105 ** </dd> | |
| 1106 ** | |
| 1107 ** <dt>SQLITE_CONFIG_SCRATCH</dt> | |
| 1108 ** <dd>This option specifies a static memory buffer that SQLite can use for | |
| 1109 ** scratch memory. There are three arguments: A pointer an 8-byte | |
| 1110 ** aligned memory buffer from which the scrach allocations will be | |
| 1111 ** drawn, the size of each scratch allocation (sz), | |
| 1112 ** and the maximum number of scratch allocations (N). The sz | |
| 1113 ** argument must be a multiple of 16. The sz parameter should be a few bytes | |
| 1114 ** larger than the actual scratch space required due to internal overhead. | |
| 1115 ** The first argument should pointer to an 8-byte aligned buffer | |
| 1116 ** of at least sz*N bytes of memory. | |
| 1117 ** SQLite will use no more than one scratch buffer at once per thread, so | |
| 1118 ** N should be set to the expected maximum number of threads. The sz | |
| 1119 ** parameter should be 6 times the size of the largest database page size. | |
| 1120 ** Scratch buffers are used as part of the btree balance operation. If | |
| 1121 ** The btree balancer needs additional memory beyond what is provided by | |
| 1122 ** scratch buffers or if no scratch buffer space is specified, then SQLite | |
| 1123 ** goes to [sqlite3_malloc()] to obtain the memory it needs.</dd> | |
| 1124 ** | |
| 1125 ** <dt>SQLITE_CONFIG_PAGECACHE</dt> | |
| 1126 ** <dd>This option specifies a static memory buffer that SQLite can use for | |
| 1127 ** the database page cache with the default page cache implemenation. | |
| 1128 ** This configuration should not be used if an application-define page | |
| 1129 ** cache implementation is loaded using the SQLITE_CONFIG_PCACHE option. | |
| 1130 ** There are three arguments to this option: A pointer to 8-byte aligned | |
| 1131 ** memory, the size of each page buffer (sz), and the number of pages (N). | |
| 1132 ** The sz argument should be the size of the largest database page | |
| 1133 ** (a power of two between 512 and 32768) plus a little extra for each | |
| 1134 ** page header. The page header size is 20 to 40 bytes depending on | |
| 1135 ** the host architecture. It is harmless, apart from the wasted memory, | |
| 1136 ** to make sz a little too large. The first | |
| 1137 ** argument should point to an allocation of at least sz*N bytes of memory. | |
| 1138 ** SQLite will use the memory provided by the first argument to satisfy its | |
| 1139 ** memory needs for the first N pages that it adds to cache. If additional | |
| 1140 ** page cache memory is needed beyond what is provided by this option, then | |
| 1141 ** SQLite goes to [sqlite3_malloc()] for the additional storage space. | |
| 1142 ** The implementation might use one or more of the N buffers to hold | |
| 1143 ** memory accounting information. The pointer in the first argument must | |
| 1144 ** be aligned to an 8-byte boundary or subsequent behavior of SQLite | |
| 1145 ** will be undefined.</dd> | |
| 1146 ** | |
| 1147 ** <dt>SQLITE_CONFIG_HEAP</dt> | |
| 1148 ** <dd>This option specifies a static memory buffer that SQLite will use | |
| 1149 ** for all of its dynamic memory allocation needs beyond those provided | |
| 1150 ** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. | |
| 1151 ** There are three arguments: An 8-byte aligned pointer to the memory, | |
| 1152 ** the number of bytes in the memory buffer, and the minimum allocation size. | |
| 1153 ** If the first pointer (the memory pointer) is NULL, then SQLite reverts | |
| 1154 ** to using its default memory allocator (the system malloc() implementation), | |
| 1155 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. If the | |
| 1156 ** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or | |
| 1157 ** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory | |
| 1158 ** allocator is engaged to handle all of SQLites memory allocation needs. | |
| 1159 ** The first pointer (the memory pointer) must be aligned to an 8-byte | |
| 1160 ** boundary or subsequent behavior of SQLite will be undefined.</dd> | |
| 1161 ** | |
| 1162 ** <dt>SQLITE_CONFIG_MUTEX</dt> | |
| 1163 ** <dd>This option takes a single argument which is a pointer to an | |
| 1164 ** instance of the [sqlite3_mutex_methods] structure. The argument specifies | |
| 1165 ** alternative low-level mutex routines to be used in place | |
| 1166 ** the mutex routines built into SQLite.</dd> | |
| 1167 ** | |
| 1168 ** <dt>SQLITE_CONFIG_GETMUTEX</dt> | |
| 1169 ** <dd>This option takes a single argument which is a pointer to an | |
| 1170 ** instance of the [sqlite3_mutex_methods] structure. The | |
| 1171 ** [sqlite3_mutex_methods] | |
| 1172 ** structure is filled with the currently defined mutex routines. | |
| 1173 ** This option can be used to overload the default mutex allocation | |
| 1174 ** routines with a wrapper used to track mutex usage for performance | |
| 1175 ** profiling or testing, for example.</dd> | |
| 1176 ** | |
| 1177 ** <dt>SQLITE_CONFIG_LOOKASIDE</dt> | |
| 1178 ** <dd>This option takes two arguments that determine the default | |
| 1179 ** memory allocation lookaside optimization. The first argument is the | |
| 1180 ** size of each lookaside buffer slot and the second is the number of | |
| 1181 ** slots allocated to each database connection. This option sets the | |
| 1182 ** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] | |
| 1183 ** verb to [sqlite3_db_config()] can be used to change the lookaside | |
| 1184 ** configuration on individual connections.</dd> | |
| 1185 ** | |
| 1186 ** <dt>SQLITE_CONFIG_PCACHE</dt> | |
| 1187 ** <dd>This option takes a single argument which is a pointer to | |
| 1188 ** an [sqlite3_pcache_methods] object. This object specifies the interface | |
| 1189 ** to a custom page cache implementation. SQLite makes a copy of the | |
| 1190 ** object and uses it for page cache memory allocations.</dd> | |
| 1191 ** | |
| 1192 ** <dt>SQLITE_CONFIG_GETPCACHE</dt> | |
| 1193 ** <dd>This option takes a single argument which is a pointer to an | |
| 1194 ** [sqlite3_pcache_methods] object. SQLite copies of the current | |
| 1195 ** page cache implementation into that object.</dd> | |
| 1196 ** | |
| 1197 ** </dl> | |
| 1198 */ | |
| 1199 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ | |
| 1200 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ | |
| 1201 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ | |
| 1202 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ | |
| 1203 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ | |
| 1204 #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ | |
| 1205 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ | |
| 1206 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ | |
| 1207 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ | |
| 1208 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ | |
| 1209 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ | |
| 1210 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ | |
| 1211 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ | |
| 1212 #define SQLITE_CONFIG_PCACHE 14 /* sqlite3_pcache_methods* */ | |
| 1213 #define SQLITE_CONFIG_GETPCACHE 15 /* sqlite3_pcache_methods* */ | |
| 1214 | |
| 1215 /* | |
| 1216 ** CAPI3REF: Configuration Options {H10170} <S20000> | |
| 1217 ** EXPERIMENTAL | |
| 1218 ** | |
| 1219 ** These constants are the available integer configuration options that | |
| 1220 ** can be passed as the second argument to the [sqlite3_db_config()] interface. | |
| 1221 ** | |
| 1222 ** New configuration options may be added in future releases of SQLite. | |
| 1223 ** Existing configuration options might be discontinued. Applications | |
| 1224 ** should check the return code from [sqlite3_db_config()] to make sure that | |
| 1225 ** the call worked. The [sqlite3_db_config()] interface will return a | |
| 1226 ** non-zero [error code] if a discontinued or unsupported configuration option | |
| 1227 ** is invoked. | |
| 1228 ** | |
| 1229 ** <dl> | |
| 1230 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> | |
| 1231 ** <dd>This option takes three additional arguments that determine the | |
| 1232 ** [lookaside memory allocator] configuration for the [database connection]. | |
| 1233 ** The first argument (the third parameter to [sqlite3_db_config()] is a | |
| 1234 ** pointer to an memory buffer to use for lookaside memory. | |
| 1235 ** The first argument may be NULL in which case SQLite will allocate the | |
| 1236 ** lookaside buffer itself using [sqlite3_malloc()]. The second argument is the | |
| 1237 ** size of each lookaside buffer slot and the third argument is the number of | |
| 1238 ** slots. The size of the buffer in the first argument must be greater than | |
| 1239 ** or equal to the product of the second and third arguments. The buffer | |
| 1240 ** must be aligned to an 8-byte boundary. If the second argument is not | |
| 1241 ** a multiple of 8, it is internally rounded down to the next smaller | |
| 1242 ** multiple of 8. See also: [SQLITE_CONFIG_LOOKASIDE]</dd> | |
| 1243 ** | |
| 1244 ** </dl> | |
| 1245 */ | |
| 1246 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ | |
| 1247 | |
| 1248 | |
| 1249 /* | |
| 1250 ** CAPI3REF: Enable Or Disable Extended Result Codes {H12200} <S10700> | |
| 1251 ** | |
| 1252 ** The sqlite3_extended_result_codes() routine enables or disables the | |
| 1253 ** [extended result codes] feature of SQLite. The extended result | |
| 1254 ** codes are disabled by default for historical compatibility considerations. | |
| 1255 ** | |
| 1256 ** Requirements: | |
| 1257 ** [H12201] [H12202] | |
| 1258 */ | |
| 1259 int sqlite3_extended_result_codes(sqlite3*, int onoff); | |
| 1260 | |
| 1261 /* | |
| 1262 ** CAPI3REF: Last Insert Rowid {H12220} <S10700> | |
| 1263 ** | |
| 1264 ** Each entry in an SQLite table has a unique 64-bit signed | |
| 1265 ** integer key called the [ROWID | "rowid"]. The rowid is always available | |
| 1266 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those | |
| 1267 ** names are not also used by explicitly declared columns. If | |
| 1268 ** the table has a column of type [INTEGER PRIMARY KEY] then that column | |
| 1269 ** is another alias for the rowid. | |
| 1270 ** | |
| 1271 ** This routine returns the [rowid] of the most recent | |
| 1272 ** successful [INSERT] into the database from the [database connection] | |
| 1273 ** in the first argument. If no successful [INSERT]s | |
| 1274 ** have ever occurred on that database connection, zero is returned. | |
| 1275 ** | |
| 1276 ** If an [INSERT] occurs within a trigger, then the [rowid] of the inserted | |
| 1277 ** row is returned by this routine as long as the trigger is running. | |
| 1278 ** But once the trigger terminates, the value returned by this routine | |
| 1279 ** reverts to the last value inserted before the trigger fired. | |
| 1280 ** | |
| 1281 ** An [INSERT] that fails due to a constraint violation is not a | |
| 1282 ** successful [INSERT] and does not change the value returned by this | |
| 1283 ** routine. Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, | |
| 1284 ** and INSERT OR ABORT make no changes to the return value of this | |
| 1285 ** routine when their insertion fails. When INSERT OR REPLACE | |
| 1286 ** encounters a constraint violation, it does not fail. The | |
| 1287 ** INSERT continues to completion after deleting rows that caused | |
| 1288 ** the constraint problem so INSERT OR REPLACE will always change | |
| 1289 ** the return value of this interface. | |
| 1290 ** | |
| 1291 ** For the purposes of this routine, an [INSERT] is considered to | |
| 1292 ** be successful even if it is subsequently rolled back. | |
| 1293 ** | |
| 1294 ** Requirements: | |
| 1295 ** [H12221] [H12223] | |
| 1296 ** | |
| 1297 ** If a separate thread performs a new [INSERT] on the same | |
| 1298 ** database connection while the [sqlite3_last_insert_rowid()] | |
| 1299 ** function is running and thus changes the last insert [rowid], | |
| 1300 ** then the value returned by [sqlite3_last_insert_rowid()] is | |
| 1301 ** unpredictable and might not equal either the old or the new | |
| 1302 ** last insert [rowid]. | |
| 1303 */ | |
| 1304 sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); | |
| 1305 | |
| 1306 /* | |
| 1307 ** CAPI3REF: Count The Number Of Rows Modified {H12240} <S10600> | |
| 1308 ** | |
| 1309 ** This function returns the number of database rows that were changed | |
| 1310 ** or inserted or deleted by the most recently completed SQL statement | |
| 1311 ** on the [database connection] specified by the first parameter. | |
| 1312 ** Only changes that are directly specified by the [INSERT], [UPDATE], | |
| 1313 ** or [DELETE] statement are counted. Auxiliary changes caused by | |
| 1314 ** triggers are not counted. Use the [sqlite3_total_changes()] function | |
| 1315 ** to find the total number of changes including changes caused by triggers. | |
| 1316 ** | |
| 1317 ** Changes to a view that are simulated by an [INSTEAD OF trigger] | |
| 1318 ** are not counted. Only real table changes are counted. | |
| 1319 ** | |
| 1320 ** A "row change" is a change to a single row of a single table | |
| 1321 ** caused by an INSERT, DELETE, or UPDATE statement. Rows that | |
| 1322 ** are changed as side effects of [REPLACE] constraint resolution, | |
| 1323 ** rollback, ABORT processing, [DROP TABLE], or by any other | |
| 1324 ** mechanisms do not count as direct row changes. | |
| 1325 ** | |
| 1326 ** A "trigger context" is a scope of execution that begins and | |
| 1327 ** ends with the script of a [CREATE TRIGGER | trigger]. | |
| 1328 ** Most SQL statements are | |
| 1329 ** evaluated outside of any trigger. This is the "top level" | |
| 1330 ** trigger context. If a trigger fires from the top level, a | |
| 1331 ** new trigger context is entered for the duration of that one | |
| 1332 ** trigger. Subtriggers create subcontexts for their duration. | |
| 1333 ** | |
| 1334 ** Calling [sqlite3_exec()] or [sqlite3_step()] recursively does | |
| 1335 ** not create a new trigger context. | |
| 1336 ** | |
| 1337 ** This function returns the number of direct row changes in the | |
| 1338 ** most recent INSERT, UPDATE, or DELETE statement within the same | |
| 1339 ** trigger context. | |
| 1340 ** | |
| 1341 ** Thus, when called from the top level, this function returns the | |
| 1342 ** number of changes in the most recent INSERT, UPDATE, or DELETE | |
| 1343 ** that also occurred at the top level. Within the body of a trigger, | |
| 1344 ** the sqlite3_changes() interface can be called to find the number of | |
| 1345 ** changes in the most recently completed INSERT, UPDATE, or DELETE | |
| 1346 ** statement within the body of the same trigger. | |
| 1347 ** However, the number returned does not include changes | |
| 1348 ** caused by subtriggers since those have their own context. | |
| 1349 ** | |
| 1350 ** See also the [sqlite3_total_changes()] interface and the | |
| 1351 ** [count_changes pragma]. | |
| 1352 ** | |
| 1353 ** Requirements: | |
| 1354 ** [H12241] [H12243] | |
| 1355 ** | |
| 1356 ** If a separate thread makes changes on the same database connection | |
| 1357 ** while [sqlite3_changes()] is running then the value returned | |
| 1358 ** is unpredictable and not meaningful. | |
| 1359 */ | |
| 1360 int sqlite3_changes(sqlite3*); | |
| 1361 | |
| 1362 /* | |
| 1363 ** CAPI3REF: Total Number Of Rows Modified {H12260} <S10600> | |
| 1364 ** | |
| 1365 ** This function returns the number of row changes caused by [INSERT], | |
| 1366 ** [UPDATE] or [DELETE] statements since the [database connection] was opened. | |
| 1367 ** The count includes all changes from all | |
| 1368 ** [CREATE TRIGGER | trigger] contexts. However, | |
| 1369 ** the count does not include changes used to implement [REPLACE] constraints, | |
| 1370 ** do rollbacks or ABORT processing, or [DROP TABLE] processing. The | |
| 1371 ** count does not include rows of views that fire an [INSTEAD OF trigger], | |
| 1372 ** though if the INSTEAD OF trigger makes changes of its own, those changes | |
| 1373 ** are counted. | |
| 1374 ** The changes are counted as soon as the statement that makes them is | |
| 1375 ** completed (when the statement handle is passed to [sqlite3_reset()] or | |
| 1376 ** [sqlite3_finalize()]). | |
| 1377 ** | |
| 1378 ** See also the [sqlite3_changes()] interface and the | |
| 1379 ** [count_changes pragma]. | |
| 1380 ** | |
| 1381 ** Requirements: | |
| 1382 ** [H12261] [H12263] | |
| 1383 ** | |
| 1384 ** If a separate thread makes changes on the same database connection | |
| 1385 ** while [sqlite3_total_changes()] is running then the value | |
| 1386 ** returned is unpredictable and not meaningful. | |
| 1387 */ | |
| 1388 int sqlite3_total_changes(sqlite3*); | |
| 1389 | |
| 1390 /* | |
| 1391 ** CAPI3REF: Interrupt A Long-Running Query {H12270} <S30500> | |
| 1392 ** | |
| 1393 ** This function causes any pending database operation to abort and | |
| 1394 ** return at its earliest opportunity. This routine is typically | |
| 1395 ** called in response to a user action such as pressing "Cancel" | |
| 1396 ** or Ctrl-C where the user wants a long query operation to halt | |
| 1397 ** immediately. | |
| 1398 ** | |
| 1399 ** It is safe to call this routine from a thread different from the | |
| 1400 ** thread that is currently running the database operation. But it | |
| 1401 ** is not safe to call this routine with a [database connection] that | |
| 1402 ** is closed or might close before sqlite3_interrupt() returns. | |
| 1403 ** | |
| 1404 ** If an SQL operation is very nearly finished at the time when | |
| 1405 ** sqlite3_interrupt() is called, then it might not have an opportunity | |
| 1406 ** to be interrupted and might continue to completion. | |
| 1407 ** | |
| 1408 ** An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. | |
| 1409 ** If the interrupted SQL operation is an INSERT, UPDATE, or DELETE | |
| 1410 ** that is inside an explicit transaction, then the entire transaction | |
| 1411 ** will be rolled back automatically. | |
| 1412 ** | |
| 1413 ** The sqlite3_interrupt(D) call is in effect until all currently running | |
| 1414 ** SQL statements on [database connection] D complete. Any new SQL statements | |
| 1415 ** that are started after the sqlite3_interrupt() call and before the | |
| 1416 ** running statements reaches zero are interrupted as if they had been | |
| 1417 ** running prior to the sqlite3_interrupt() call. New SQL statements | |
| 1418 ** that are started after the running statement count reaches zero are | |
| 1419 ** not effected by the sqlite3_interrupt(). | |
| 1420 ** A call to sqlite3_interrupt(D) that occurs when there are no running | |
| 1421 ** SQL statements is a no-op and has no effect on SQL statements | |
| 1422 ** that are started after the sqlite3_interrupt() call returns. | |
| 1423 ** | |
| 1424 ** Requirements: | |
| 1425 ** [H12271] [H12272] | |
| 1426 ** | |
| 1427 ** If the database connection closes while [sqlite3_interrupt()] | |
| 1428 ** is running then bad things will likely happen. | |
| 1429 */ | |
| 1430 void sqlite3_interrupt(sqlite3*); | |
| 1431 | |
| 1432 /* | |
| 1433 ** CAPI3REF: Determine If An SQL Statement Is Complete {H10510} <S70200> | |
| 1434 ** | |
| 1435 ** These routines are useful during command-line input to determine if the | |
| 1436 ** currently entered text seems to form a complete SQL statement or | |
| 1437 ** if additional input is needed before sending the text into | |
| 1438 ** SQLite for parsing. These routines return 1 if the input string | |
| 1439 ** appears to be a complete SQL statement. A statement is judged to be | |
| 1440 ** complete if it ends with a semicolon token and is not a prefix of a | |
| 1441 ** well-formed CREATE TRIGGER statement. Semicolons that are embedded within | |
| 1442 ** string literals or quoted identifier names or comments are not | |
| 1443 ** independent tokens (they are part of the token in which they are | |
| 1444 ** embedded) and thus do not count as a statement terminator. Whitespace | |
| 1445 ** and comments that follow the final semicolon are ignored. | |
| 1446 ** | |
| 1447 ** These routines return 0 if the statement is incomplete. If a | |
| 1448 ** memory allocation fails, then SQLITE_NOMEM is returned. | |
| 1449 ** | |
| 1450 ** These routines do not parse the SQL statements thus | |
| 1451 ** will not detect syntactically incorrect SQL. | |
| 1452 ** | |
| 1453 ** If SQLite has not been initialized using [sqlite3_initialize()] prior | |
| 1454 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked | |
| 1455 ** automatically by sqlite3_complete16(). If that initialization fails, | |
| 1456 ** then the return value from sqlite3_complete16() will be non-zero | |
| 1457 ** regardless of whether or not the input SQL is complete. | |
| 1458 ** | |
| 1459 ** Requirements: [H10511] [H10512] | |
| 1460 ** | |
| 1461 ** The input to [sqlite3_complete()] must be a zero-terminated | |
| 1462 ** UTF-8 string. | |
| 1463 ** | |
| 1464 ** The input to [sqlite3_complete16()] must be a zero-terminated | |
| 1465 ** UTF-16 string in native byte order. | |
| 1466 */ | |
| 1467 int sqlite3_complete(const char *sql); | |
| 1468 int sqlite3_complete16(const void *sql); | |
| 1469 | |
| 1470 /* | |
| 1471 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors {H12310} <S40400> | |
| 1472 ** | |
| 1473 ** This routine sets a callback function that might be invoked whenever | |
| 1474 ** an attempt is made to open a database table that another thread | |
| 1475 ** or process has locked. | |
| 1476 ** | |
| 1477 ** If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] | |
| 1478 ** is returned immediately upon encountering the lock. If the busy callback | |
| 1479 ** is not NULL, then the callback will be invoked with two arguments. | |
| 1480 ** | |
| 1481 ** The first argument to the handler is a copy of the void* pointer which | |
| 1482 ** is the third argument to sqlite3_busy_handler(). The second argument to | |
| 1483 ** the handler callback is the number of times that the busy handler has | |
| 1484 ** been invoked for this locking event. If the | |
| 1485 ** busy callback returns 0, then no additional attempts are made to | |
| 1486 ** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. | |
| 1487 ** If the callback returns non-zero, then another attempt | |
| 1488 ** is made to open the database for reading and the cycle repeats. | |
| 1489 ** | |
| 1490 ** The presence of a busy handler does not guarantee that it will be invoked | |
| 1491 ** when there is lock contention. If SQLite determines that invoking the busy | |
| 1492 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] | |
| 1493 ** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. | |
| 1494 ** Consider a scenario where one process is holding a read lock that | |
| 1495 ** it is trying to promote to a reserved lock and | |
| 1496 ** a second process is holding a reserved lock that it is trying | |
| 1497 ** to promote to an exclusive lock. The first process cannot proceed | |
| 1498 ** because it is blocked by the second and the second process cannot | |
| 1499 ** proceed because it is blocked by the first. If both processes | |
| 1500 ** invoke the busy handlers, neither will make any progress. Therefore, | |
| 1501 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this | |
| 1502 ** will induce the first process to release its read lock and allow | |
| 1503 ** the second process to proceed. | |
| 1504 ** | |
| 1505 ** The default busy callback is NULL. | |
| 1506 ** | |
| 1507 ** The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] | |
| 1508 ** when SQLite is in the middle of a large transaction where all the | |
| 1509 ** changes will not fit into the in-memory cache. SQLite will | |
| 1510 ** already hold a RESERVED lock on the database file, but it needs | |
| 1511 ** to promote this lock to EXCLUSIVE so that it can spill cache | |
| 1512 ** pages into the database file without harm to concurrent | |
| 1513 ** readers. If it is unable to promote the lock, then the in-memory | |
| 1514 ** cache will be left in an inconsistent state and so the error | |
| 1515 ** code is promoted from the relatively benign [SQLITE_BUSY] to | |
| 1516 ** the more severe [SQLITE_IOERR_BLOCKED]. This error code promotion | |
| 1517 ** forces an automatic rollback of the changes. See the | |
| 1518 ** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError"> | |
| 1519 ** CorruptionFollowingBusyError</a> wiki page for a discussion of why | |
| 1520 ** this is important. | |
| 1521 ** | |
| 1522 ** There can only be a single busy handler defined for each | |
| 1523 ** [database connection]. Setting a new busy handler clears any | |
| 1524 ** previously set handler. Note that calling [sqlite3_busy_timeout()] | |
| 1525 ** will also set or clear the busy handler. | |
| 1526 ** | |
| 1527 ** The busy callback should not take any actions which modify the | |
| 1528 ** database connection that invoked the busy handler. Any such actions | |
| 1529 ** result in undefined behavior. | |
| 1530 ** | |
| 1531 ** Requirements: | |
| 1532 ** [H12311] [H12312] [H12314] [H12316] [H12318] | |
| 1533 ** | |
| 1534 ** A busy handler must not close the database connection | |
| 1535 ** or [prepared statement] that invoked the busy handler. | |
| 1536 */ | |
| 1537 int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); | |
| 1538 | |
| 1539 /* | |
| 1540 ** CAPI3REF: Set A Busy Timeout {H12340} <S40410> | |
| 1541 ** | |
| 1542 ** This routine sets a [sqlite3_busy_handler | busy handler] that sleeps | |
| 1543 ** for a specified amount of time when a table is locked. The handler | |
| 1544 ** will sleep multiple times until at least "ms" milliseconds of sleeping | |
| 1545 ** have accumulated. {H12343} After "ms" milliseconds of sleeping, | |
| 1546 ** the handler returns 0 which causes [sqlite3_step()] to return | |
| 1547 ** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. | |
| 1548 ** | |
| 1549 ** Calling this routine with an argument less than or equal to zero | |
| 1550 ** turns off all busy handlers. | |
| 1551 ** | |
| 1552 ** There can only be a single busy handler for a particular | |
| 1553 ** [database connection] any any given moment. If another busy handler | |
| 1554 ** was defined (using [sqlite3_busy_handler()]) prior to calling | |
| 1555 ** this routine, that other busy handler is cleared. | |
| 1556 ** | |
| 1557 ** Requirements: | |
| 1558 ** [H12341] [H12343] [H12344] | |
| 1559 */ | |
| 1560 int sqlite3_busy_timeout(sqlite3*, int ms); | |
| 1561 | |
| 1562 /* | |
| 1563 ** CAPI3REF: Convenience Routines For Running Queries {H12370} <S10000> | |
| 1564 ** | |
| 1565 ** Definition: A <b>result table</b> is memory data structure created by the | |
| 1566 ** [sqlite3_get_table()] interface. A result table records the | |
| 1567 ** complete query results from one or more queries. | |
| 1568 ** | |
| 1569 ** The table conceptually has a number of rows and columns. But | |
| 1570 ** these numbers are not part of the result table itself. These | |
| 1571 ** numbers are obtained separately. Let N be the number of rows | |
| 1572 ** and M be the number of columns. | |
| 1573 ** | |
| 1574 ** A result table is an array of pointers to zero-terminated UTF-8 strings. | |
| 1575 ** There are (N+1)*M elements in the array. The first M pointers point | |
| 1576 ** to zero-terminated strings that contain the names of the columns. | |
| 1577 ** The remaining entries all point to query results. NULL values result | |
| 1578 ** in NULL pointers. All other values are in their UTF-8 zero-terminated | |
| 1579 ** string representation as returned by [sqlite3_column_text()]. | |
| 1580 ** | |
| 1581 ** A result table might consist of one or more memory allocations. | |
| 1582 ** It is not safe to pass a result table directly to [sqlite3_free()]. | |
| 1583 ** A result table should be deallocated using [sqlite3_free_table()]. | |
| 1584 ** | |
| 1585 ** As an example of the result table format, suppose a query result | |
| 1586 ** is as follows: | |
| 1587 ** | |
| 1588 ** <blockquote><pre> | |
| 1589 ** Name | Age | |
| 1590 ** ----------------------- | |
| 1591 ** Alice | 43 | |
| 1592 ** Bob | 28 | |
| 1593 ** Cindy | 21 | |
| 1594 ** </pre></blockquote> | |
| 1595 ** | |
| 1596 ** There are two column (M==2) and three rows (N==3). Thus the | |
| 1597 ** result table has 8 entries. Suppose the result table is stored | |
| 1598 ** in an array names azResult. Then azResult holds this content: | |
| 1599 ** | |
| 1600 ** <blockquote><pre> | |
| 1601 ** azResult[0] = "Name"; | |
| 1602 ** azResult[1] = "Age"; | |
| 1603 ** azResult[2] = "Alice"; | |
| 1604 ** azResult[3] = "43"; | |
| 1605 ** azResult[4] = "Bob"; | |
| 1606 ** azResult[5] = "28"; | |
| 1607 ** azResult[6] = "Cindy"; | |
| 1608 ** azResult[7] = "21"; | |
| 1609 ** </pre></blockquote> | |
| 1610 ** | |
| 1611 ** The sqlite3_get_table() function evaluates one or more | |
| 1612 ** semicolon-separated SQL statements in the zero-terminated UTF-8 | |
| 1613 ** string of its 2nd parameter. It returns a result table to the | |
| 1614 ** pointer given in its 3rd parameter. | |
| 1615 ** | |
| 1616 ** After the calling function has finished using the result, it should | |
| 1617 ** pass the pointer to the result table to sqlite3_free_table() in order to | |
| 1618 ** release the memory that was malloced. Because of the way the | |
| 1619 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling | |
| 1620 ** function must not try to call [sqlite3_free()] directly. Only | |
| 1621 ** [sqlite3_free_table()] is able to release the memory properly and safely. | |
| 1622 ** | |
| 1623 ** The sqlite3_get_table() interface is implemented as a wrapper around | |
| 1624 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access | |
| 1625 ** to any internal data structures of SQLite. It uses only the public | |
| 1626 ** interface defined here. As a consequence, errors that occur in the | |
| 1627 ** wrapper layer outside of the internal [sqlite3_exec()] call are not | |
| 1628 ** reflected in subsequent calls to [sqlite3_errcode()] or [sqlite3_errmsg()]. | |
| 1629 ** | |
| 1630 ** Requirements: | |
| 1631 ** [H12371] [H12373] [H12374] [H12376] [H12379] [H12382] | |
| 1632 */ | |
| 1633 int sqlite3_get_table( | |
| 1634 sqlite3 *db, /* An open database */ | |
| 1635 const char *zSql, /* SQL to be evaluated */ | |
| 1636 char ***pazResult, /* Results of the query */ | |
| 1637 int *pnRow, /* Number of result rows written here */ | |
| 1638 int *pnColumn, /* Number of result columns written here */ | |
| 1639 char **pzErrmsg /* Error msg written here */ | |
| 1640 ); | |
| 1641 void sqlite3_free_table(char **result); | |
| 1642 | |
| 1643 /* | |
| 1644 ** CAPI3REF: Formatted String Printing Functions {H17400} <S70000><S20000> | |
| 1645 ** | |
| 1646 ** These routines are work-alikes of the "printf()" family of functions | |
| 1647 ** from the standard C library. | |
| 1648 ** | |
| 1649 ** The sqlite3_mprintf() and sqlite3_vmprintf() routines write their | |
| 1650 ** results into memory obtained from [sqlite3_malloc()]. | |
| 1651 ** The strings returned by these two routines should be | |
| 1652 ** released by [sqlite3_free()]. Both routines return a | |
| 1653 ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough | |
| 1654 ** memory to hold the resulting string. | |
| 1655 ** | |
| 1656 ** In sqlite3_snprintf() routine is similar to "snprintf()" from | |
| 1657 ** the standard C library. The result is written into the | |
| 1658 ** buffer supplied as the second parameter whose size is given by | |
| 1659 ** the first parameter. Note that the order of the | |
| 1660 ** first two parameters is reversed from snprintf(). This is an | |
| 1661 ** historical accident that cannot be fixed without breaking | |
| 1662 ** backwards compatibility. Note also that sqlite3_snprintf() | |
| 1663 ** returns a pointer to its buffer instead of the number of | |
| 1664 ** characters actually written into the buffer. We admit that | |
| 1665 ** the number of characters written would be a more useful return | |
| 1666 ** value but we cannot change the implementation of sqlite3_snprintf() | |
| 1667 ** now without breaking compatibility. | |
| 1668 ** | |
| 1669 ** As long as the buffer size is greater than zero, sqlite3_snprintf() | |
| 1670 ** guarantees that the buffer is always zero-terminated. The first | |
| 1671 ** parameter "n" is the total size of the buffer, including space for | |
| 1672 ** the zero terminator. So the longest string that can be completely | |
| 1673 ** written will be n-1 characters. | |
| 1674 ** | |
| 1675 ** These routines all implement some additional formatting | |
| 1676 ** options that are useful for constructing SQL statements. | |
| 1677 ** All of the usual printf() formatting options apply. In addition, there | |
| 1678 ** is are "%q", "%Q", and "%z" options. | |
| 1679 ** | |
| 1680 ** The %q option works like %s in that it substitutes a null-terminated | |
| 1681 ** string from the argument list. But %q also doubles every '\'' character. | |
| 1682 ** %q is designed for use inside a string literal. By doubling each '\'' | |
| 1683 ** character it escapes that character and allows it to be inserted into | |
| 1684 ** the string. | |
| 1685 ** | |
| 1686 ** For example, assume the string variable zText contains text as follows: | |
| 1687 ** | |
| 1688 ** <blockquote><pre> | |
| 1689 ** char *zText = "It's a happy day!"; | |
| 1690 ** </pre></blockquote> | |
| 1691 ** | |
| 1692 ** One can use this text in an SQL statement as follows: | |
| 1693 ** | |
| 1694 ** <blockquote><pre> | |
| 1695 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); | |
| 1696 ** sqlite3_exec(db, zSQL, 0, 0, 0); | |
| 1697 ** sqlite3_free(zSQL); | |
| 1698 ** </pre></blockquote> | |
| 1699 ** | |
| 1700 ** Because the %q format string is used, the '\'' character in zText | |
| 1701 ** is escaped and the SQL generated is as follows: | |
| 1702 ** | |
| 1703 ** <blockquote><pre> | |
| 1704 ** INSERT INTO table1 VALUES('It''s a happy day!') | |
| 1705 ** </pre></blockquote> | |
| 1706 ** | |
| 1707 ** This is correct. Had we used %s instead of %q, the generated SQL | |
| 1708 ** would have looked like this: | |
| 1709 ** | |
| 1710 ** <blockquote><pre> | |
| 1711 ** INSERT INTO table1 VALUES('It's a happy day!'); | |
| 1712 ** </pre></blockquote> | |
| 1713 ** | |
| 1714 ** This second example is an SQL syntax error. As a general rule you should | |
| 1715 ** always use %q instead of %s when inserting text into a string literal. | |
| 1716 ** | |
| 1717 ** The %Q option works like %q except it also adds single quotes around | |
| 1718 ** the outside of the total string. Additionally, if the parameter in the | |
| 1719 ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without | |
| 1720 ** single quotes) in place of the %Q option. So, for example, one could say: | |
| 1721 ** | |
| 1722 ** <blockquote><pre> | |
| 1723 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); | |
| 1724 ** sqlite3_exec(db, zSQL, 0, 0, 0); | |
| 1725 ** sqlite3_free(zSQL); | |
| 1726 ** </pre></blockquote> | |
| 1727 ** | |
| 1728 ** The code above will render a correct SQL statement in the zSQL | |
| 1729 ** variable even if the zText variable is a NULL pointer. | |
| 1730 ** | |
| 1731 ** The "%z" formatting option works exactly like "%s" with the | |
| 1732 ** addition that after the string has been read and copied into | |
| 1733 ** the result, [sqlite3_free()] is called on the input string. {END} | |
| 1734 ** | |
| 1735 ** Requirements: | |
| 1736 ** [H17403] [H17406] [H17407] | |
| 1737 */ | |
| 1738 char *sqlite3_mprintf(const char*,...); | |
| 1739 char *sqlite3_vmprintf(const char*, va_list); | |
| 1740 char *sqlite3_snprintf(int,char*,const char*, ...); | |
| 1741 | |
| 1742 /* | |
| 1743 ** CAPI3REF: Memory Allocation Subsystem {H17300} <S20000> | |
| 1744 ** | |
| 1745 ** The SQLite core uses these three routines for all of its own | |
| 1746 ** internal memory allocation needs. "Core" in the previous sentence | |
| 1747 ** does not include operating-system specific VFS implementation. The | |
| 1748 ** Windows VFS uses native malloc() and free() for some operations. | |
| 1749 ** | |
| 1750 ** The sqlite3_malloc() routine returns a pointer to a block | |
| 1751 ** of memory at least N bytes in length, where N is the parameter. | |
| 1752 ** If sqlite3_malloc() is unable to obtain sufficient free | |
| 1753 ** memory, it returns a NULL pointer. If the parameter N to | |
| 1754 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns | |
| 1755 ** a NULL pointer. | |
| 1756 ** | |
| 1757 ** Calling sqlite3_free() with a pointer previously returned | |
| 1758 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so | |
| 1759 ** that it might be reused. The sqlite3_free() routine is | |
| 1760 ** a no-op if is called with a NULL pointer. Passing a NULL pointer | |
| 1761 ** to sqlite3_free() is harmless. After being freed, memory | |
| 1762 ** should neither be read nor written. Even reading previously freed | |
| 1763 ** memory might result in a segmentation fault or other severe error. | |
| 1764 ** Memory corruption, a segmentation fault, or other severe error | |
| 1765 ** might result if sqlite3_free() is called with a non-NULL pointer that | |
| 1766 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). | |
| 1767 ** | |
| 1768 ** The sqlite3_realloc() interface attempts to resize a | |
| 1769 ** prior memory allocation to be at least N bytes, where N is the | |
| 1770 ** second parameter. The memory allocation to be resized is the first | |
| 1771 ** parameter. If the first parameter to sqlite3_realloc() | |
| 1772 ** is a NULL pointer then its behavior is identical to calling | |
| 1773 ** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). | |
| 1774 ** If the second parameter to sqlite3_realloc() is zero or | |
| 1775 ** negative then the behavior is exactly the same as calling | |
| 1776 ** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). | |
| 1777 ** sqlite3_realloc() returns a pointer to a memory allocation | |
| 1778 ** of at least N bytes in size or NULL if sufficient memory is unavailable. | |
| 1779 ** If M is the size of the prior allocation, then min(N,M) bytes | |
| 1780 ** of the prior allocation are copied into the beginning of buffer returned | |
| 1781 ** by sqlite3_realloc() and the prior allocation is freed. | |
| 1782 ** If sqlite3_realloc() returns NULL, then the prior allocation | |
| 1783 ** is not freed. | |
| 1784 ** | |
| 1785 ** The memory returned by sqlite3_malloc() and sqlite3_realloc() | |
| 1786 ** is always aligned to at least an 8 byte boundary. {END} | |
| 1787 ** | |
| 1788 ** The default implementation of the memory allocation subsystem uses | |
| 1789 ** the malloc(), realloc() and free() provided by the standard C library. | |
| 1790 ** {H17382} However, if SQLite is compiled with the | |
| 1791 ** SQLITE_MEMORY_SIZE=<i>NNN</i> C preprocessor macro (where <i>NNN</i> | |
| 1792 ** is an integer), then SQLite create a static array of at least | |
| 1793 ** <i>NNN</i> bytes in size and uses that array for all of its dynamic | |
| 1794 ** memory allocation needs. {END} Additional memory allocator options | |
| 1795 ** may be added in future releases. | |
| 1796 ** | |
| 1797 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define | |
| 1798 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in | |
| 1799 ** implementation of these routines to be omitted. That capability | |
| 1800 ** is no longer provided. Only built-in memory allocators can be used. | |
| 1801 ** | |
| 1802 ** The Windows OS interface layer calls | |
| 1803 ** the system malloc() and free() directly when converting | |
| 1804 ** filenames between the UTF-8 encoding used by SQLite | |
| 1805 ** and whatever filename encoding is used by the particular Windows | |
| 1806 ** installation. Memory allocation errors are detected, but | |
| 1807 ** they are reported back as [SQLITE_CANTOPEN] or | |
| 1808 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. | |
| 1809 ** | |
| 1810 ** Requirements: | |
| 1811 ** [H17303] [H17304] [H17305] [H17306] [H17310] [H17312] [H17315] [H17318] | |
| 1812 ** [H17321] [H17322] [H17323] | |
| 1813 ** | |
| 1814 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] | |
| 1815 ** must be either NULL or else pointers obtained from a prior | |
| 1816 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have | |
| 1817 ** not yet been released. | |
| 1818 ** | |
| 1819 ** The application must not read or write any part of | |
| 1820 ** a block of memory after it has been released using | |
| 1821 ** [sqlite3_free()] or [sqlite3_realloc()]. | |
| 1822 */ | |
| 1823 void *sqlite3_malloc(int); | |
| 1824 void *sqlite3_realloc(void*, int); | |
| 1825 void sqlite3_free(void*); | |
| 1826 | |
| 1827 /* | |
| 1828 ** CAPI3REF: Memory Allocator Statistics {H17370} <S30210> | |
| 1829 ** | |
| 1830 ** SQLite provides these two interfaces for reporting on the status | |
| 1831 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] | |
| 1832 ** routines, which form the built-in memory allocation subsystem. | |
| 1833 ** | |
| 1834 ** Requirements: | |
| 1835 ** [H17371] [H17373] [H17374] [H17375] | |
| 1836 */ | |
| 1837 sqlite3_int64 sqlite3_memory_used(void); | |
| 1838 sqlite3_int64 sqlite3_memory_highwater(int resetFlag); | |
| 1839 | |
| 1840 /* | |
| 1841 ** CAPI3REF: Pseudo-Random Number Generator {H17390} <S20000> | |
| 1842 ** | |
| 1843 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to | |
| 1844 ** select random [ROWID | ROWIDs] when inserting new records into a table that | |
| 1845 ** already uses the largest possible [ROWID]. The PRNG is also used for | |
| 1846 ** the build-in random() and randomblob() SQL functions. This interface allows | |
| 1847 ** applications to access the same PRNG for other purposes. | |
| 1848 ** | |
| 1849 ** A call to this routine stores N bytes of randomness into buffer P. | |
| 1850 ** | |
| 1851 ** The first time this routine is invoked (either internally or by | |
| 1852 ** the application) the PRNG is seeded using randomness obtained | |
| 1853 ** from the xRandomness method of the default [sqlite3_vfs] object. | |
| 1854 ** On all subsequent invocations, the pseudo-randomness is generated | |
| 1855 ** internally and without recourse to the [sqlite3_vfs] xRandomness | |
| 1856 ** method. | |
| 1857 ** | |
| 1858 ** Requirements: | |
| 1859 ** [H17392] | |
| 1860 */ | |
| 1861 void sqlite3_randomness(int N, void *P); | |
| 1862 | |
| 1863 /* | |
| 1864 ** CAPI3REF: Compile-Time Authorization Callbacks {H12500} <S70100> | |
| 1865 ** | |
| 1866 ** This routine registers a authorizer callback with a particular | |
| 1867 ** [database connection], supplied in the first argument. | |
| 1868 ** The authorizer callback is invoked as SQL statements are being compiled | |
| 1869 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], | |
| 1870 ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. At various | |
| 1871 ** points during the compilation process, as logic is being created | |
| 1872 ** to perform various actions, the authorizer callback is invoked to | |
| 1873 ** see if those actions are allowed. The authorizer callback should | |
| 1874 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the | |
| 1875 ** specific action but allow the SQL statement to continue to be | |
| 1876 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be | |
| 1877 ** rejected with an error. If the authorizer callback returns | |
| 1878 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] | |
| 1879 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered | |
| 1880 ** the authorizer will fail with an error message. | |
| 1881 ** | |
| 1882 ** When the callback returns [SQLITE_OK], that means the operation | |
| 1883 ** requested is ok. When the callback returns [SQLITE_DENY], the | |
| 1884 ** [sqlite3_prepare_v2()] or equivalent call that triggered the | |
| 1885 ** authorizer will fail with an error message explaining that | |
| 1886 ** access is denied. | |
| 1887 ** | |
| 1888 ** The first parameter to the authorizer callback is a copy of the third | |
| 1889 ** parameter to the sqlite3_set_authorizer() interface. The second parameter | |
| 1890 ** to the callback is an integer [SQLITE_COPY | action code] that specifies | |
| 1891 ** the particular action to be authorized. The third through sixth parameters | |
| 1892 ** to the callback are zero-terminated strings that contain additional | |
| 1893 ** details about the action to be authorized. | |
| 1894 ** | |
| 1895 ** If the action code is [SQLITE_READ] | |
| 1896 ** and the callback returns [SQLITE_IGNORE] then the | |
| 1897 ** [prepared statement] statement is constructed to substitute | |
| 1898 ** a NULL value in place of the table column that would have | |
| 1899 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] | |
| 1900 ** return can be used to deny an untrusted user access to individual | |
| 1901 ** columns of a table. | |
| 1902 ** If the action code is [SQLITE_DELETE] and the callback returns | |
| 1903 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the | |
| 1904 ** [truncate optimization] is disabled and all rows are deleted individually. | |
| 1905 ** | |
| 1906 ** An authorizer is used when [sqlite3_prepare | preparing] | |
| 1907 ** SQL statements from an untrusted source, to ensure that the SQL statements | |
| 1908 ** do not try to access data they are not allowed to see, or that they do not | |
| 1909 ** try to execute malicious statements that damage the database. For | |
| 1910 ** example, an application may allow a user to enter arbitrary | |
| 1911 ** SQL queries for evaluation by a database. But the application does | |
| 1912 ** not want the user to be able to make arbitrary changes to the | |
| 1913 ** database. An authorizer could then be put in place while the | |
| 1914 ** user-entered SQL is being [sqlite3_prepare | prepared] that | |
| 1915 ** disallows everything except [SELECT] statements. | |
| 1916 ** | |
| 1917 ** Applications that need to process SQL from untrusted sources | |
| 1918 ** might also consider lowering resource limits using [sqlite3_limit()] | |
| 1919 ** and limiting database size using the [max_page_count] [PRAGMA] | |
| 1920 ** in addition to using an authorizer. | |
| 1921 ** | |
| 1922 ** Only a single authorizer can be in place on a database connection | |
| 1923 ** at a time. Each call to sqlite3_set_authorizer overrides the | |
| 1924 ** previous call. Disable the authorizer by installing a NULL callback. | |
| 1925 ** The authorizer is disabled by default. | |
| 1926 ** | |
| 1927 ** The authorizer callback must not do anything that will modify | |
| 1928 ** the database connection that invoked the authorizer callback. | |
| 1929 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their | |
| 1930 ** database connections for the meaning of "modify" in this paragraph. | |
| 1931 ** | |
| 1932 ** When [sqlite3_prepare_v2()] is used to prepare a statement, the | |
| 1933 ** statement might be re-prepared during [sqlite3_step()] due to a | |
| 1934 ** schema change. Hence, the application should ensure that the | |
| 1935 ** correct authorizer callback remains in place during the [sqlite3_step()]. | |
| 1936 ** | |
| 1937 ** Note that the authorizer callback is invoked only during | |
| 1938 ** [sqlite3_prepare()] or its variants. Authorization is not | |
| 1939 ** performed during statement evaluation in [sqlite3_step()], unless | |
| 1940 ** as stated in the previous paragraph, sqlite3_step() invokes | |
| 1941 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. | |
| 1942 ** | |
| 1943 ** Requirements: | |
| 1944 ** [H12501] [H12502] [H12503] [H12504] [H12505] [H12506] [H12507] [H12510] | |
| 1945 ** [H12511] [H12512] [H12520] [H12521] [H12522] | |
| 1946 */ | |
| 1947 int sqlite3_set_authorizer( | |
| 1948 sqlite3*, | |
| 1949 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), | |
| 1950 void *pUserData | |
| 1951 ); | |
| 1952 | |
| 1953 /* | |
| 1954 ** CAPI3REF: Authorizer Return Codes {H12590} <H12500> | |
| 1955 ** | |
| 1956 ** The [sqlite3_set_authorizer | authorizer callback function] must | |
| 1957 ** return either [SQLITE_OK] or one of these two constants in order | |
| 1958 ** to signal SQLite whether or not the action is permitted. See the | |
| 1959 ** [sqlite3_set_authorizer | authorizer documentation] for additional | |
| 1960 ** information. | |
| 1961 */ | |
| 1962 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ | |
| 1963 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ | |
| 1964 | |
| 1965 /* | |
| 1966 ** CAPI3REF: Authorizer Action Codes {H12550} <H12500> | |
| 1967 ** | |
| 1968 ** The [sqlite3_set_authorizer()] interface registers a callback function | |
| 1969 ** that is invoked to authorize certain SQL statement actions. The | |
| 1970 ** second parameter to the callback is an integer code that specifies | |
| 1971 ** what action is being authorized. These are the integer action codes that | |
| 1972 ** the authorizer callback may be passed. | |
| 1973 ** | |
| 1974 ** These action code values signify what kind of operation is to be | |
| 1975 ** authorized. The 3rd and 4th parameters to the authorization | |
| 1976 ** callback function will be parameters or NULL depending on which of these | |
| 1977 ** codes is used as the second parameter. The 5th parameter to the | |
| 1978 ** authorizer callback is the name of the database ("main", "temp", | |
| 1979 ** etc.) if applicable. The 6th parameter to the authorizer callback | |
| 1980 ** is the name of the inner-most trigger or view that is responsible for | |
| 1981 ** the access attempt or NULL if this access attempt is directly from | |
| 1982 ** top-level SQL code. | |
| 1983 ** | |
| 1984 ** Requirements: | |
| 1985 ** [H12551] [H12552] [H12553] [H12554] | |
| 1986 */ | |
| 1987 /******************************************* 3rd ************ 4th ***********/ | |
| 1988 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ | |
| 1989 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ | |
| 1990 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ | |
| 1991 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ | |
| 1992 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ | |
| 1993 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ | |
| 1994 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ | |
| 1995 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ | |
| 1996 #define SQLITE_DELETE 9 /* Table Name NULL */ | |
| 1997 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ | |
| 1998 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ | |
| 1999 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ | |
| 2000 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ | |
| 2001 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ | |
| 2002 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ | |
| 2003 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ | |
| 2004 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ | |
| 2005 #define SQLITE_INSERT 18 /* Table Name NULL */ | |
| 2006 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ | |
| 2007 #define SQLITE_READ 20 /* Table Name Column Name */ | |
| 2008 #define SQLITE_SELECT 21 /* NULL NULL */ | |
| 2009 #define SQLITE_TRANSACTION 22 /* Operation NULL */ | |
| 2010 #define SQLITE_UPDATE 23 /* Table Name Column Name */ | |
| 2011 #define SQLITE_ATTACH 24 /* Filename NULL */ | |
| 2012 #define SQLITE_DETACH 25 /* Database Name NULL */ | |
| 2013 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ | |
| 2014 #define SQLITE_REINDEX 27 /* Index Name NULL */ | |
| 2015 #define SQLITE_ANALYZE 28 /* Table Name NULL */ | |
| 2016 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ | |
| 2017 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ | |
| 2018 #define SQLITE_FUNCTION 31 /* NULL Function Name */ | |
| 2019 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ | |
| 2020 #define SQLITE_COPY 0 /* No longer used */ | |
| 2021 | |
| 2022 /* | |
| 2023 ** CAPI3REF: Tracing And Profiling Functions {H12280} <S60400> | |
| 2024 ** EXPERIMENTAL | |
| 2025 ** | |
| 2026 ** These routines register callback functions that can be used for | |
| 2027 ** tracing and profiling the execution of SQL statements. | |
| 2028 ** | |
| 2029 ** The callback function registered by sqlite3_trace() is invoked at | |
| 2030 ** various times when an SQL statement is being run by [sqlite3_step()]. | |
| 2031 ** The callback returns a UTF-8 rendering of the SQL statement text | |
| 2032 ** as the statement first begins executing. Additional callbacks occur | |
| 2033 ** as each triggered subprogram is entered. The callbacks for triggers | |
| 2034 ** contain a UTF-8 SQL comment that identifies the trigger. | |
| 2035 ** | |
| 2036 ** The callback function registered by sqlite3_profile() is invoked | |
| 2037 ** as each SQL statement finishes. The profile callback contains | |
| 2038 ** the original statement text and an estimate of wall-clock time | |
| 2039 ** of how long that statement took to run. | |
| 2040 ** | |
| 2041 ** Requirements: | |
| 2042 ** [H12281] [H12282] [H12283] [H12284] [H12285] [H12287] [H12288] [H12289] | |
| 2043 ** [H12290] | |
| 2044 */ | |
| 2045 SQLITE_EXPERIMENTAL void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char
*), void*); | |
| 2046 SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, | |
| 2047 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); | |
| 2048 | |
| 2049 /* | |
| 2050 ** CAPI3REF: Query Progress Callbacks {H12910} <S60400> | |
| 2051 ** | |
| 2052 ** This routine configures a callback function - the | |
| 2053 ** progress callback - that is invoked periodically during long | |
| 2054 ** running calls to [sqlite3_exec()], [sqlite3_step()] and | |
| 2055 ** [sqlite3_get_table()]. An example use for this | |
| 2056 ** interface is to keep a GUI updated during a large query. | |
| 2057 ** | |
| 2058 ** If the progress callback returns non-zero, the operation is | |
| 2059 ** interrupted. This feature can be used to implement a | |
| 2060 ** "Cancel" button on a GUI progress dialog box. | |
| 2061 ** | |
| 2062 ** The progress handler must not do anything that will modify | |
| 2063 ** the database connection that invoked the progress handler. | |
| 2064 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their | |
| 2065 ** database connections for the meaning of "modify" in this paragraph. | |
| 2066 ** | |
| 2067 ** Requirements: | |
| 2068 ** [H12911] [H12912] [H12913] [H12914] [H12915] [H12916] [H12917] [H12918] | |
| 2069 ** | |
| 2070 */ | |
| 2071 void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); | |
| 2072 | |
| 2073 /* | |
| 2074 ** CAPI3REF: Opening A New Database Connection {H12700} <S40200> | |
| 2075 ** | |
| 2076 ** These routines open an SQLite database file whose name is given by the | |
| 2077 ** filename argument. The filename argument is interpreted as UTF-8 for | |
| 2078 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte | |
| 2079 ** order for sqlite3_open16(). A [database connection] handle is usually | |
| 2080 ** returned in *ppDb, even if an error occurs. The only exception is that | |
| 2081 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, | |
| 2082 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] | |
| 2083 ** object. If the database is opened (and/or created) successfully, then | |
| 2084 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned. The | |
| 2085 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain | |
| 2086 ** an English language description of the error. | |
| 2087 ** | |
| 2088 ** The default encoding for the database will be UTF-8 if | |
| 2089 ** sqlite3_open() or sqlite3_open_v2() is called and | |
| 2090 ** UTF-16 in the native byte order if sqlite3_open16() is used. | |
| 2091 ** | |
| 2092 ** Whether or not an error occurs when it is opened, resources | |
| 2093 ** associated with the [database connection] handle should be released by | |
| 2094 ** passing it to [sqlite3_close()] when it is no longer required. | |
| 2095 ** | |
| 2096 ** The sqlite3_open_v2() interface works like sqlite3_open() | |
| 2097 ** except that it accepts two additional parameters for additional control | |
| 2098 ** over the new database connection. The flags parameter can take one of | |
| 2099 ** the following three values, optionally combined with the | |
| 2100 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], | |
| 2101 ** and/or [SQLITE_OPEN_PRIVATECACHE] flags: | |
| 2102 ** | |
| 2103 ** <dl> | |
| 2104 ** <dt>[SQLITE_OPEN_READONLY]</dt> | |
| 2105 ** <dd>The database is opened in read-only mode. If the database does not | |
| 2106 ** already exist, an error is returned.</dd> | |
| 2107 ** | |
| 2108 ** <dt>[SQLITE_OPEN_READWRITE]</dt> | |
| 2109 ** <dd>The database is opened for reading and writing if possible, or reading | |
| 2110 ** only if the file is write protected by the operating system. In either | |
| 2111 ** case the database must already exist, otherwise an error is returned.</dd> | |
| 2112 ** | |
| 2113 ** <dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> | |
| 2114 ** <dd>The database is opened for reading and writing, and is creates it if | |
| 2115 ** it does not already exist. This is the behavior that is always used for | |
| 2116 ** sqlite3_open() and sqlite3_open16().</dd> | |
| 2117 ** </dl> | |
| 2118 ** | |
| 2119 ** If the 3rd parameter to sqlite3_open_v2() is not one of the | |
| 2120 ** combinations shown above or one of the combinations shown above combined | |
| 2121 ** with the [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], | |
| 2122 ** [SQLITE_OPEN_SHAREDCACHE] and/or [SQLITE_OPEN_SHAREDCACHE] flags, | |
| 2123 ** then the behavior is undefined. | |
| 2124 ** | |
| 2125 ** If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection | |
| 2126 ** opens in the multi-thread [threading mode] as long as the single-thread | |
| 2127 ** mode has not been set at compile-time or start-time. If the | |
| 2128 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens | |
| 2129 ** in the serialized [threading mode] unless single-thread was | |
| 2130 ** previously selected at compile-time or start-time. | |
| 2131 ** The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be | |
| 2132 ** eligible to use [shared cache mode], regardless of whether or not shared | |
| 2133 ** cache is enabled using [sqlite3_enable_shared_cache()]. The | |
| 2134 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not | |
| 2135 ** participate in [shared cache mode] even if it is enabled. | |
| 2136 ** | |
| 2137 ** If the filename is ":memory:", then a private, temporary in-memory database | |
| 2138 ** is created for the connection. This in-memory database will vanish when | |
| 2139 ** the database connection is closed. Future versions of SQLite might | |
| 2140 ** make use of additional special filenames that begin with the ":" character. | |
| 2141 ** It is recommended that when a database filename actually does begin with | |
| 2142 ** a ":" character you should prefix the filename with a pathname such as | |
| 2143 ** "./" to avoid ambiguity. | |
| 2144 ** | |
| 2145 ** If the filename is an empty string, then a private, temporary | |
| 2146 ** on-disk database will be created. This private database will be | |
| 2147 ** automatically deleted as soon as the database connection is closed. | |
| 2148 ** | |
| 2149 ** The fourth parameter to sqlite3_open_v2() is the name of the | |
| 2150 ** [sqlite3_vfs] object that defines the operating system interface that | |
| 2151 ** the new database connection should use. If the fourth parameter is | |
| 2152 ** a NULL pointer then the default [sqlite3_vfs] object is used. | |
| 2153 ** | |
| 2154 ** <b>Note to Windows users:</b> The encoding used for the filename argument | |
| 2155 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever | |
| 2156 ** codepage is currently defined. Filenames containing international | |
| 2157 ** characters must be converted to UTF-8 prior to passing them into | |
| 2158 ** sqlite3_open() or sqlite3_open_v2(). | |
| 2159 ** | |
| 2160 ** Requirements: | |
| 2161 ** [H12701] [H12702] [H12703] [H12704] [H12706] [H12707] [H12709] [H12711] | |
| 2162 ** [H12712] [H12713] [H12714] [H12717] [H12719] [H12721] [H12723] | |
| 2163 */ | |
| 2164 int sqlite3_open( | |
| 2165 const char *filename, /* Database filename (UTF-8) */ | |
| 2166 sqlite3 **ppDb /* OUT: SQLite db handle */ | |
| 2167 ); | |
| 2168 int sqlite3_open16( | |
| 2169 const void *filename, /* Database filename (UTF-16) */ | |
| 2170 sqlite3 **ppDb /* OUT: SQLite db handle */ | |
| 2171 ); | |
| 2172 int sqlite3_open_v2( | |
| 2173 const char *filename, /* Database filename (UTF-8) */ | |
| 2174 sqlite3 **ppDb, /* OUT: SQLite db handle */ | |
| 2175 int flags, /* Flags */ | |
| 2176 const char *zVfs /* Name of VFS module to use */ | |
| 2177 ); | |
| 2178 | |
| 2179 /* | |
| 2180 ** CAPI3REF: Error Codes And Messages {H12800} <S60200> | |
| 2181 ** | |
| 2182 ** The sqlite3_errcode() interface returns the numeric [result code] or | |
| 2183 ** [extended result code] for the most recent failed sqlite3_* API call | |
| 2184 ** associated with a [database connection]. If a prior API call failed | |
| 2185 ** but the most recent API call succeeded, the return value from | |
| 2186 ** sqlite3_errcode() is undefined. The sqlite3_extended_errcode() | |
| 2187 ** interface is the same except that it always returns the | |
| 2188 ** [extended result code] even when extended result codes are | |
| 2189 ** disabled. | |
| 2190 ** | |
| 2191 ** The sqlite3_errmsg() and sqlite3_errmsg16() return English-language | |
| 2192 ** text that describes the error, as either UTF-8 or UTF-16 respectively. | |
| 2193 ** Memory to hold the error message string is managed internally. | |
| 2194 ** The application does not need to worry about freeing the result. | |
| 2195 ** However, the error string might be overwritten or deallocated by | |
| 2196 ** subsequent calls to other SQLite interface functions. | |
| 2197 ** | |
| 2198 ** When the serialized [threading mode] is in use, it might be the | |
| 2199 ** case that a second error occurs on a separate thread in between | |
| 2200 ** the time of the first error and the call to these interfaces. | |
| 2201 ** When that happens, the second error will be reported since these | |
| 2202 ** interfaces always report the most recent result. To avoid | |
| 2203 ** this, each thread can obtain exclusive use of the [database connection] D | |
| 2204 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning | |
| 2205 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after | |
| 2206 ** all calls to the interfaces listed here are completed. | |
| 2207 ** | |
| 2208 ** If an interface fails with SQLITE_MISUSE, that means the interface | |
| 2209 ** was invoked incorrectly by the application. In that case, the | |
| 2210 ** error code and message may or may not be set. | |
| 2211 ** | |
| 2212 ** Requirements: | |
| 2213 ** [H12801] [H12802] [H12803] [H12807] [H12808] [H12809] | |
| 2214 */ | |
| 2215 int sqlite3_errcode(sqlite3 *db); | |
| 2216 int sqlite3_extended_errcode(sqlite3 *db); | |
| 2217 const char *sqlite3_errmsg(sqlite3*); | |
| 2218 const void *sqlite3_errmsg16(sqlite3*); | |
| 2219 | |
| 2220 /* | |
| 2221 ** CAPI3REF: SQL Statement Object {H13000} <H13010> | |
| 2222 ** KEYWORDS: {prepared statement} {prepared statements} | |
| 2223 ** | |
| 2224 ** An instance of this object represents a single SQL statement. | |
| 2225 ** This object is variously known as a "prepared statement" or a | |
| 2226 ** "compiled SQL statement" or simply as a "statement". | |
| 2227 ** | |
| 2228 ** The life of a statement object goes something like this: | |
| 2229 ** | |
| 2230 ** <ol> | |
| 2231 ** <li> Create the object using [sqlite3_prepare_v2()] or a related | |
| 2232 ** function. | |
| 2233 ** <li> Bind values to [host parameters] using the sqlite3_bind_*() | |
| 2234 ** interfaces. | |
| 2235 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. | |
| 2236 ** <li> Reset the statement using [sqlite3_reset()] then go back | |
| 2237 ** to step 2. Do this zero or more times. | |
| 2238 ** <li> Destroy the object using [sqlite3_finalize()]. | |
| 2239 ** </ol> | |
| 2240 ** | |
| 2241 ** Refer to documentation on individual methods above for additional | |
| 2242 ** information. | |
| 2243 */ | |
| 2244 typedef struct sqlite3_stmt sqlite3_stmt; | |
| 2245 | |
| 2246 /* | |
| 2247 ** CAPI3REF: Run-time Limits {H12760} <S20600> | |
| 2248 ** | |
| 2249 ** This interface allows the size of various constructs to be limited | |
| 2250 ** on a connection by connection basis. The first parameter is the | |
| 2251 ** [database connection] whose limit is to be set or queried. The | |
| 2252 ** second parameter is one of the [limit categories] that define a | |
| 2253 ** class of constructs to be size limited. The third parameter is the | |
| 2254 ** new limit for that construct. The function returns the old limit. | |
| 2255 ** | |
| 2256 ** If the new limit is a negative number, the limit is unchanged. | |
| 2257 ** For the limit category of SQLITE_LIMIT_XYZ there is a | |
| 2258 ** [limits | hard upper bound] | |
| 2259 ** set by a compile-time C preprocessor macro named | |
| 2260 ** [limits | SQLITE_MAX_XYZ]. | |
| 2261 ** (The "_LIMIT_" in the name is changed to "_MAX_".) | |
| 2262 ** Attempts to increase a limit above its hard upper bound are | |
| 2263 ** silently truncated to the hard upper limit. | |
| 2264 ** | |
| 2265 ** Run time limits are intended for use in applications that manage | |
| 2266 ** both their own internal database and also databases that are controlled | |
| 2267 ** by untrusted external sources. An example application might be a | |
| 2268 ** web browser that has its own databases for storing history and | |
| 2269 ** separate databases controlled by JavaScript applications downloaded | |
| 2270 ** off the Internet. The internal databases can be given the | |
| 2271 ** large, default limits. Databases managed by external sources can | |
| 2272 ** be given much smaller limits designed to prevent a denial of service | |
| 2273 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] | |
| 2274 ** interface to further control untrusted SQL. The size of the database | |
| 2275 ** created by an untrusted script can be contained using the | |
| 2276 ** [max_page_count] [PRAGMA]. | |
| 2277 ** | |
| 2278 ** New run-time limit categories may be added in future releases. | |
| 2279 ** | |
| 2280 ** Requirements: | |
| 2281 ** [H12762] [H12766] [H12769] | |
| 2282 */ | |
| 2283 int sqlite3_limit(sqlite3*, int id, int newVal); | |
| 2284 | |
| 2285 /* | |
| 2286 ** CAPI3REF: Run-Time Limit Categories {H12790} <H12760> | |
| 2287 ** KEYWORDS: {limit category} {limit categories} | |
| 2288 ** | |
| 2289 ** These constants define various performance limits | |
| 2290 ** that can be lowered at run-time using [sqlite3_limit()]. | |
| 2291 ** The synopsis of the meanings of the various limits is shown below. | |
| 2292 ** Additional information is available at [limits | Limits in SQLite]. | |
| 2293 ** | |
| 2294 ** <dl> | |
| 2295 ** <dt>SQLITE_LIMIT_LENGTH</dt> | |
| 2296 ** <dd>The maximum size of any string or BLOB or table row.<dd> | |
| 2297 ** | |
| 2298 ** <dt>SQLITE_LIMIT_SQL_LENGTH</dt> | |
| 2299 ** <dd>The maximum length of an SQL statement.</dd> | |
| 2300 ** | |
| 2301 ** <dt>SQLITE_LIMIT_COLUMN</dt> | |
| 2302 ** <dd>The maximum number of columns in a table definition or in the | |
| 2303 ** result set of a [SELECT] or the maximum number of columns in an index | |
| 2304 ** or in an ORDER BY or GROUP BY clause.</dd> | |
| 2305 ** | |
| 2306 ** <dt>SQLITE_LIMIT_EXPR_DEPTH</dt> | |
| 2307 ** <dd>The maximum depth of the parse tree on any expression.</dd> | |
| 2308 ** | |
| 2309 ** <dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> | |
| 2310 ** <dd>The maximum number of terms in a compound SELECT statement.</dd> | |
| 2311 ** | |
| 2312 ** <dt>SQLITE_LIMIT_VDBE_OP</dt> | |
| 2313 ** <dd>The maximum number of instructions in a virtual machine program | |
| 2314 ** used to implement an SQL statement.</dd> | |
| 2315 ** | |
| 2316 ** <dt>SQLITE_LIMIT_FUNCTION_ARG</dt> | |
| 2317 ** <dd>The maximum number of arguments on a function.</dd> | |
| 2318 ** | |
| 2319 ** <dt>SQLITE_LIMIT_ATTACHED</dt> | |
| 2320 ** <dd>The maximum number of [ATTACH | attached databases].</dd> | |
| 2321 ** | |
| 2322 ** <dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> | |
| 2323 ** <dd>The maximum length of the pattern argument to the [LIKE] or | |
| 2324 ** [GLOB] operators.</dd> | |
| 2325 ** | |
| 2326 ** <dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> | |
| 2327 ** <dd>The maximum number of variables in an SQL statement that can | |
| 2328 ** be bound.</dd> | |
| 2329 ** | |
| 2330 ** <dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> | |
| 2331 ** <dd>The maximum depth of recursion for triggers.</dd> | |
| 2332 ** </dl> | |
| 2333 */ | |
| 2334 #define SQLITE_LIMIT_LENGTH 0 | |
| 2335 #define SQLITE_LIMIT_SQL_LENGTH 1 | |
| 2336 #define SQLITE_LIMIT_COLUMN 2 | |
| 2337 #define SQLITE_LIMIT_EXPR_DEPTH 3 | |
| 2338 #define SQLITE_LIMIT_COMPOUND_SELECT 4 | |
| 2339 #define SQLITE_LIMIT_VDBE_OP 5 | |
| 2340 #define SQLITE_LIMIT_FUNCTION_ARG 6 | |
| 2341 #define SQLITE_LIMIT_ATTACHED 7 | |
| 2342 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 | |
| 2343 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 | |
| 2344 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 | |
| 2345 | |
| 2346 /* | |
| 2347 ** CAPI3REF: Compiling An SQL Statement {H13010} <S10000> | |
| 2348 ** KEYWORDS: {SQL statement compiler} | |
| 2349 ** | |
| 2350 ** To execute an SQL query, it must first be compiled into a byte-code | |
| 2351 ** program using one of these routines. | |
| 2352 ** | |
| 2353 ** The first argument, "db", is a [database connection] obtained from a | |
| 2354 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or | |
| 2355 ** [sqlite3_open16()]. The database connection must not have been closed. | |
| 2356 ** | |
| 2357 ** The second argument, "zSql", is the statement to be compiled, encoded | |
| 2358 ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() | |
| 2359 ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() | |
| 2360 ** use UTF-16. | |
| 2361 ** | |
| 2362 ** If the nByte argument is less than zero, then zSql is read up to the | |
| 2363 ** first zero terminator. If nByte is non-negative, then it is the maximum | |
| 2364 ** number of bytes read from zSql. When nByte is non-negative, the | |
| 2365 ** zSql string ends at either the first '\000' or '\u0000' character or | |
| 2366 ** the nByte-th byte, whichever comes first. If the caller knows | |
| 2367 ** that the supplied string is nul-terminated, then there is a small | |
| 2368 ** performance advantage to be gained by passing an nByte parameter that | |
| 2369 ** is equal to the number of bytes in the input string <i>including</i> | |
| 2370 ** the nul-terminator bytes. | |
| 2371 ** | |
| 2372 ** If pzTail is not NULL then *pzTail is made to point to the first byte | |
| 2373 ** past the end of the first SQL statement in zSql. These routines only | |
| 2374 ** compile the first statement in zSql, so *pzTail is left pointing to | |
| 2375 ** what remains uncompiled. | |
| 2376 ** | |
| 2377 ** *ppStmt is left pointing to a compiled [prepared statement] that can be | |
| 2378 ** executed using [sqlite3_step()]. If there is an error, *ppStmt is set | |
| 2379 ** to NULL. If the input text contains no SQL (if the input is an empty | |
| 2380 ** string or a comment) then *ppStmt is set to NULL. | |
| 2381 ** The calling procedure is responsible for deleting the compiled | |
| 2382 ** SQL statement using [sqlite3_finalize()] after it has finished with it. | |
| 2383 ** ppStmt may not be NULL. | |
| 2384 ** | |
| 2385 ** On success, [SQLITE_OK] is returned, otherwise an [error code] is returned. | |
| 2386 ** | |
| 2387 ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are | |
| 2388 ** recommended for all new programs. The two older interfaces are retained | |
| 2389 ** for backwards compatibility, but their use is discouraged. | |
| 2390 ** In the "v2" interfaces, the prepared statement | |
| 2391 ** that is returned (the [sqlite3_stmt] object) contains a copy of the | |
| 2392 ** original SQL text. This causes the [sqlite3_step()] interface to | |
| 2393 ** behave a differently in two ways: | |
| 2394 ** | |
| 2395 ** <ol> | |
| 2396 ** <li> | |
| 2397 ** If the database schema changes, instead of returning [SQLITE_SCHEMA] as it | |
| 2398 ** always used to do, [sqlite3_step()] will automatically recompile the SQL | |
| 2399 ** statement and try to run it again. If the schema has changed in | |
| 2400 ** a way that makes the statement no longer valid, [sqlite3_step()] will still | |
| 2401 ** return [SQLITE_SCHEMA]. But unlike the legacy behavior, [SQLITE_SCHEMA] is | |
| 2402 ** now a fatal error. Calling [sqlite3_prepare_v2()] again will not make the | |
| 2403 ** error go away. Note: use [sqlite3_errmsg()] to find the text | |
| 2404 ** of the parsing error that results in an [SQLITE_SCHEMA] return. | |
| 2405 ** </li> | |
| 2406 ** | |
| 2407 ** <li> | |
| 2408 ** When an error occurs, [sqlite3_step()] will return one of the detailed | |
| 2409 ** [error codes] or [extended error codes]. The legacy behavior was that | |
| 2410 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code | |
| 2411 ** and you would have to make a second call to [sqlite3_reset()] in order | |
| 2412 ** to find the underlying cause of the problem. With the "v2" prepare | |
| 2413 ** interfaces, the underlying reason for the error is returned immediately. | |
| 2414 ** </li> | |
| 2415 ** </ol> | |
| 2416 ** | |
| 2417 ** Requirements: | |
| 2418 ** [H13011] [H13012] [H13013] [H13014] [H13015] [H13016] [H13019] [H13021] | |
| 2419 ** | |
| 2420 */ | |
| 2421 int sqlite3_prepare( | |
| 2422 sqlite3 *db, /* Database handle */ | |
| 2423 const char *zSql, /* SQL statement, UTF-8 encoded */ | |
| 2424 int nByte, /* Maximum length of zSql in bytes. */ | |
| 2425 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ | |
| 2426 const char **pzTail /* OUT: Pointer to unused portion of zSql */ | |
| 2427 ); | |
| 2428 int sqlite3_prepare_v2( | |
| 2429 sqlite3 *db, /* Database handle */ | |
| 2430 const char *zSql, /* SQL statement, UTF-8 encoded */ | |
| 2431 int nByte, /* Maximum length of zSql in bytes. */ | |
| 2432 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ | |
| 2433 const char **pzTail /* OUT: Pointer to unused portion of zSql */ | |
| 2434 ); | |
| 2435 int sqlite3_prepare16( | |
| 2436 sqlite3 *db, /* Database handle */ | |
| 2437 const void *zSql, /* SQL statement, UTF-16 encoded */ | |
| 2438 int nByte, /* Maximum length of zSql in bytes. */ | |
| 2439 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ | |
| 2440 const void **pzTail /* OUT: Pointer to unused portion of zSql */ | |
| 2441 ); | |
| 2442 int sqlite3_prepare16_v2( | |
| 2443 sqlite3 *db, /* Database handle */ | |
| 2444 const void *zSql, /* SQL statement, UTF-16 encoded */ | |
| 2445 int nByte, /* Maximum length of zSql in bytes. */ | |
| 2446 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ | |
| 2447 const void **pzTail /* OUT: Pointer to unused portion of zSql */ | |
| 2448 ); | |
| 2449 | |
| 2450 /* | |
| 2451 ** CAPI3REF: Retrieving Statement SQL {H13100} <H13000> | |
| 2452 ** | |
| 2453 ** This interface can be used to retrieve a saved copy of the original | |
| 2454 ** SQL text used to create a [prepared statement] if that statement was | |
| 2455 ** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. | |
| 2456 ** | |
| 2457 ** Requirements: | |
| 2458 ** [H13101] [H13102] [H13103] | |
| 2459 */ | |
| 2460 const char *sqlite3_sql(sqlite3_stmt *pStmt); | |
| 2461 | |
| 2462 /* | |
| 2463 ** CAPI3REF: Dynamically Typed Value Object {H15000} <S20200> | |
| 2464 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} | |
| 2465 ** | |
| 2466 ** SQLite uses the sqlite3_value object to represent all values | |
| 2467 ** that can be stored in a database table. SQLite uses dynamic typing | |
| 2468 ** for the values it stores. Values stored in sqlite3_value objects | |
| 2469 ** can be integers, floating point values, strings, BLOBs, or NULL. | |
| 2470 ** | |
| 2471 ** An sqlite3_value object may be either "protected" or "unprotected". | |
| 2472 ** Some interfaces require a protected sqlite3_value. Other interfaces | |
| 2473 ** will accept either a protected or an unprotected sqlite3_value. | |
| 2474 ** Every interface that accepts sqlite3_value arguments specifies | |
| 2475 ** whether or not it requires a protected sqlite3_value. | |
| 2476 ** | |
| 2477 ** The terms "protected" and "unprotected" refer to whether or not | |
| 2478 ** a mutex is held. A internal mutex is held for a protected | |
| 2479 ** sqlite3_value object but no mutex is held for an unprotected | |
| 2480 ** sqlite3_value object. If SQLite is compiled to be single-threaded | |
| 2481 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) | |
| 2482 ** or if SQLite is run in one of reduced mutex modes | |
| 2483 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] | |
| 2484 ** then there is no distinction between protected and unprotected | |
| 2485 ** sqlite3_value objects and they can be used interchangeably. However, | |
| 2486 ** for maximum code portability it is recommended that applications | |
| 2487 ** still make the distinction between between protected and unprotected | |
| 2488 ** sqlite3_value objects even when not strictly required. | |
| 2489 ** | |
| 2490 ** The sqlite3_value objects that are passed as parameters into the | |
| 2491 ** implementation of [application-defined SQL functions] are protected. | |
| 2492 ** The sqlite3_value object returned by | |
| 2493 ** [sqlite3_column_value()] is unprotected. | |
| 2494 ** Unprotected sqlite3_value objects may only be used with | |
| 2495 ** [sqlite3_result_value()] and [sqlite3_bind_value()]. | |
| 2496 ** The [sqlite3_value_blob | sqlite3_value_type()] family of | |
| 2497 ** interfaces require protected sqlite3_value objects. | |
| 2498 */ | |
| 2499 typedef struct Mem sqlite3_value; | |
| 2500 | |
| 2501 /* | |
| 2502 ** CAPI3REF: SQL Function Context Object {H16001} <S20200> | |
| 2503 ** | |
| 2504 ** The context in which an SQL function executes is stored in an | |
| 2505 ** sqlite3_context object. A pointer to an sqlite3_context object | |
| 2506 ** is always first parameter to [application-defined SQL functions]. | |
| 2507 ** The application-defined SQL function implementation will pass this | |
| 2508 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], | |
| 2509 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], | |
| 2510 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], | |
| 2511 ** and/or [sqlite3_set_auxdata()]. | |
| 2512 */ | |
| 2513 typedef struct sqlite3_context sqlite3_context; | |
| 2514 | |
| 2515 /* | |
| 2516 ** CAPI3REF: Binding Values To Prepared Statements {H13500} <S70300> | |
| 2517 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} | |
| 2518 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} | |
| 2519 ** | |
| 2520 ** In the SQL strings input to [sqlite3_prepare_v2()] and its variants, | |
| 2521 ** literals may be replaced by a [parameter] that matches one of following | |
| 2522 ** templates: | |
| 2523 ** | |
| 2524 ** <ul> | |
| 2525 ** <li> ? | |
| 2526 ** <li> ?NNN | |
| 2527 ** <li> :VVV | |
| 2528 ** <li> @VVV | |
| 2529 ** <li> $VVV | |
| 2530 ** </ul> | |
| 2531 ** | |
| 2532 ** In the templates above, NNN represents an integer literal, | |
| 2533 ** and VVV represents an alphanumeric identifer. The values of these | |
| 2534 ** parameters (also called "host parameter names" or "SQL parameters") | |
| 2535 ** can be set using the sqlite3_bind_*() routines defined here. | |
| 2536 ** | |
| 2537 ** The first argument to the sqlite3_bind_*() routines is always | |
| 2538 ** a pointer to the [sqlite3_stmt] object returned from | |
| 2539 ** [sqlite3_prepare_v2()] or its variants. | |
| 2540 ** | |
| 2541 ** The second argument is the index of the SQL parameter to be set. | |
| 2542 ** The leftmost SQL parameter has an index of 1. When the same named | |
| 2543 ** SQL parameter is used more than once, second and subsequent | |
| 2544 ** occurrences have the same index as the first occurrence. | |
| 2545 ** The index for named parameters can be looked up using the | |
| 2546 ** [sqlite3_bind_parameter_index()] API if desired. The index | |
| 2547 ** for "?NNN" parameters is the value of NNN. | |
| 2548 ** The NNN value must be between 1 and the [sqlite3_limit()] | |
| 2549 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). | |
| 2550 ** | |
| 2551 ** The third argument is the value to bind to the parameter. | |
| 2552 ** | |
| 2553 ** In those routines that have a fourth argument, its value is the | |
| 2554 ** number of bytes in the parameter. To be clear: the value is the | |
| 2555 ** number of <u>bytes</u> in the value, not the number of characters. | |
| 2556 ** If the fourth parameter is negative, the length of the string is | |
| 2557 ** the number of bytes up to the first zero terminator. | |
| 2558 ** | |
| 2559 ** The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and | |
| 2560 ** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or | |
| 2561 ** string after SQLite has finished with it. If the fifth argument is | |
| 2562 ** the special value [SQLITE_STATIC], then SQLite assumes that the | |
| 2563 ** information is in static, unmanaged space and does not need to be freed. | |
| 2564 ** If the fifth argument has the value [SQLITE_TRANSIENT], then | |
| 2565 ** SQLite makes its own private copy of the data immediately, before | |
| 2566 ** the sqlite3_bind_*() routine returns. | |
| 2567 ** | |
| 2568 ** The sqlite3_bind_zeroblob() routine binds a BLOB of length N that | |
| 2569 ** is filled with zeroes. A zeroblob uses a fixed amount of memory | |
| 2570 ** (just an integer to hold its size) while it is being processed. | |
| 2571 ** Zeroblobs are intended to serve as placeholders for BLOBs whose | |
| 2572 ** content is later written using | |
| 2573 ** [sqlite3_blob_open | incremental BLOB I/O] routines. | |
| 2574 ** A negative value for the zeroblob results in a zero-length BLOB. | |
| 2575 ** | |
| 2576 ** The sqlite3_bind_*() routines must be called after | |
| 2577 ** [sqlite3_prepare_v2()] (and its variants) or [sqlite3_reset()] and | |
| 2578 ** before [sqlite3_step()]. | |
| 2579 ** Bindings are not cleared by the [sqlite3_reset()] routine. | |
| 2580 ** Unbound parameters are interpreted as NULL. | |
| 2581 ** | |
| 2582 ** These routines return [SQLITE_OK] on success or an error code if | |
| 2583 ** anything goes wrong. [SQLITE_RANGE] is returned if the parameter | |
| 2584 ** index is out of range. [SQLITE_NOMEM] is returned if malloc() fails. | |
| 2585 ** [SQLITE_MISUSE] might be returned if these routines are called on a | |
| 2586 ** virtual machine that is the wrong state or which has already been finalized. | |
| 2587 ** Detection of misuse is unreliable. Applications should not depend | |
| 2588 ** on SQLITE_MISUSE returns. SQLITE_MISUSE is intended to indicate a | |
| 2589 ** a logic error in the application. Future versions of SQLite might | |
| 2590 ** panic rather than return SQLITE_MISUSE. | |
| 2591 ** | |
| 2592 ** See also: [sqlite3_bind_parameter_count()], | |
| 2593 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. | |
| 2594 ** | |
| 2595 ** Requirements: | |
| 2596 ** [H13506] [H13509] [H13512] [H13515] [H13518] [H13521] [H13524] [H13527] | |
| 2597 ** [H13530] [H13533] [H13536] [H13539] [H13542] [H13545] [H13548] [H13551] | |
| 2598 ** | |
| 2599 */ | |
| 2600 int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); | |
| 2601 int sqlite3_bind_double(sqlite3_stmt*, int, double); | |
| 2602 int sqlite3_bind_int(sqlite3_stmt*, int, int); | |
| 2603 int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); | |
| 2604 int sqlite3_bind_null(sqlite3_stmt*, int); | |
| 2605 int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); | |
| 2606 int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); | |
| 2607 int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); | |
| 2608 int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); | |
| 2609 | |
| 2610 /* | |
| 2611 ** CAPI3REF: Number Of SQL Parameters {H13600} <S70300> | |
| 2612 ** | |
| 2613 ** This routine can be used to find the number of [SQL parameters] | |
| 2614 ** in a [prepared statement]. SQL parameters are tokens of the | |
| 2615 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as | |
| 2616 ** placeholders for values that are [sqlite3_bind_blob | bound] | |
| 2617 ** to the parameters at a later time. | |
| 2618 ** | |
| 2619 ** This routine actually returns the index of the largest (rightmost) | |
| 2620 ** parameter. For all forms except ?NNN, this will correspond to the | |
| 2621 ** number of unique parameters. If parameters of the ?NNN are used, | |
| 2622 ** there may be gaps in the list. | |
| 2623 ** | |
| 2624 ** See also: [sqlite3_bind_blob|sqlite3_bind()], | |
| 2625 ** [sqlite3_bind_parameter_name()], and | |
| 2626 ** [sqlite3_bind_parameter_index()]. | |
| 2627 ** | |
| 2628 ** Requirements: | |
| 2629 ** [H13601] | |
| 2630 */ | |
| 2631 int sqlite3_bind_parameter_count(sqlite3_stmt*); | |
| 2632 | |
| 2633 /* | |
| 2634 ** CAPI3REF: Name Of A Host Parameter {H13620} <S70300> | |
| 2635 ** | |
| 2636 ** This routine returns a pointer to the name of the n-th | |
| 2637 ** [SQL parameter] in a [prepared statement]. | |
| 2638 ** SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" | |
| 2639 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" | |
| 2640 ** respectively. | |
| 2641 ** In other words, the initial ":" or "$" or "@" or "?" | |
| 2642 ** is included as part of the name. | |
| 2643 ** Parameters of the form "?" without a following integer have no name | |
| 2644 ** and are also referred to as "anonymous parameters". | |
| 2645 ** | |
| 2646 ** The first host parameter has an index of 1, not 0. | |
| 2647 ** | |
| 2648 ** If the value n is out of range or if the n-th parameter is | |
| 2649 ** nameless, then NULL is returned. The returned string is | |
| 2650 ** always in UTF-8 encoding even if the named parameter was | |
| 2651 ** originally specified as UTF-16 in [sqlite3_prepare16()] or | |
| 2652 ** [sqlite3_prepare16_v2()]. | |
| 2653 ** | |
| 2654 ** See also: [sqlite3_bind_blob|sqlite3_bind()], | |
| 2655 ** [sqlite3_bind_parameter_count()], and | |
| 2656 ** [sqlite3_bind_parameter_index()]. | |
| 2657 ** | |
| 2658 ** Requirements: | |
| 2659 ** [H13621] | |
| 2660 */ | |
| 2661 const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); | |
| 2662 | |
| 2663 /* | |
| 2664 ** CAPI3REF: Index Of A Parameter With A Given Name {H13640} <S70300> | |
| 2665 ** | |
| 2666 ** Return the index of an SQL parameter given its name. The | |
| 2667 ** index value returned is suitable for use as the second | |
| 2668 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. A zero | |
| 2669 ** is returned if no matching parameter is found. The parameter | |
| 2670 ** name must be given in UTF-8 even if the original statement | |
| 2671 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. | |
| 2672 ** | |
| 2673 ** See also: [sqlite3_bind_blob|sqlite3_bind()], | |
| 2674 ** [sqlite3_bind_parameter_count()], and | |
| 2675 ** [sqlite3_bind_parameter_index()]. | |
| 2676 ** | |
| 2677 ** Requirements: | |
| 2678 ** [H13641] | |
| 2679 */ | |
| 2680 int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); | |
| 2681 | |
| 2682 /* | |
| 2683 ** CAPI3REF: Reset All Bindings On A Prepared Statement {H13660} <S70300> | |
| 2684 ** | |
| 2685 ** Contrary to the intuition of many, [sqlite3_reset()] does not reset | |
| 2686 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. | |
| 2687 ** Use this routine to reset all host parameters to NULL. | |
| 2688 ** | |
| 2689 ** Requirements: | |
| 2690 ** [H13661] | |
| 2691 */ | |
| 2692 int sqlite3_clear_bindings(sqlite3_stmt*); | |
| 2693 | |
| 2694 /* | |
| 2695 ** CAPI3REF: Number Of Columns In A Result Set {H13710} <S10700> | |
| 2696 ** | |
| 2697 ** Return the number of columns in the result set returned by the | |
| 2698 ** [prepared statement]. This routine returns 0 if pStmt is an SQL | |
| 2699 ** statement that does not return data (for example an [UPDATE]). | |
| 2700 ** | |
| 2701 ** Requirements: | |
| 2702 ** [H13711] | |
| 2703 */ | |
| 2704 int sqlite3_column_count(sqlite3_stmt *pStmt); | |
| 2705 | |
| 2706 /* | |
| 2707 ** CAPI3REF: Column Names In A Result Set {H13720} <S10700> | |
| 2708 ** | |
| 2709 ** These routines return the name assigned to a particular column | |
| 2710 ** in the result set of a [SELECT] statement. The sqlite3_column_name() | |
| 2711 ** interface returns a pointer to a zero-terminated UTF-8 string | |
| 2712 ** and sqlite3_column_name16() returns a pointer to a zero-terminated | |
| 2713 ** UTF-16 string. The first parameter is the [prepared statement] | |
| 2714 ** that implements the [SELECT] statement. The second parameter is the | |
| 2715 ** column number. The leftmost column is number 0. | |
| 2716 ** | |
| 2717 ** The returned string pointer is valid until either the [prepared statement] | |
| 2718 ** is destroyed by [sqlite3_finalize()] or until the next call to | |
| 2719 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. | |
| 2720 ** | |
| 2721 ** If sqlite3_malloc() fails during the processing of either routine | |
| 2722 ** (for example during a conversion from UTF-8 to UTF-16) then a | |
| 2723 ** NULL pointer is returned. | |
| 2724 ** | |
| 2725 ** The name of a result column is the value of the "AS" clause for | |
| 2726 ** that column, if there is an AS clause. If there is no AS clause | |
| 2727 ** then the name of the column is unspecified and may change from | |
| 2728 ** one release of SQLite to the next. | |
| 2729 ** | |
| 2730 ** Requirements: | |
| 2731 ** [H13721] [H13723] [H13724] [H13725] [H13726] [H13727] | |
| 2732 */ | |
| 2733 const char *sqlite3_column_name(sqlite3_stmt*, int N); | |
| 2734 const void *sqlite3_column_name16(sqlite3_stmt*, int N); | |
| 2735 | |
| 2736 /* | |
| 2737 ** CAPI3REF: Source Of Data In A Query Result {H13740} <S10700> | |
| 2738 ** | |
| 2739 ** These routines provide a means to determine what column of what | |
| 2740 ** table in which database a result of a [SELECT] statement comes from. | |
| 2741 ** The name of the database or table or column can be returned as | |
| 2742 ** either a UTF-8 or UTF-16 string. The _database_ routines return | |
| 2743 ** the database name, the _table_ routines return the table name, and | |
| 2744 ** the origin_ routines return the column name. | |
| 2745 ** The returned string is valid until the [prepared statement] is destroyed | |
| 2746 ** using [sqlite3_finalize()] or until the same information is requested | |
| 2747 ** again in a different encoding. | |
| 2748 ** | |
| 2749 ** The names returned are the original un-aliased names of the | |
| 2750 ** database, table, and column. | |
| 2751 ** | |
| 2752 ** The first argument to the following calls is a [prepared statement]. | |
| 2753 ** These functions return information about the Nth column returned by | |
| 2754 ** the statement, where N is the second function argument. | |
| 2755 ** | |
| 2756 ** If the Nth column returned by the statement is an expression or | |
| 2757 ** subquery and is not a column value, then all of these functions return | |
| 2758 ** NULL. These routine might also return NULL if a memory allocation error | |
| 2759 ** occurs. Otherwise, they return the name of the attached database, table | |
| 2760 ** and column that query result column was extracted from. | |
| 2761 ** | |
| 2762 ** As with all other SQLite APIs, those postfixed with "16" return | |
| 2763 ** UTF-16 encoded strings, the other functions return UTF-8. {END} | |
| 2764 ** | |
| 2765 ** These APIs are only available if the library was compiled with the | |
| 2766 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. | |
| 2767 ** | |
| 2768 ** {A13751} | |
| 2769 ** If two or more threads call one or more of these routines against the same | |
| 2770 ** prepared statement and column at the same time then the results are | |
| 2771 ** undefined. | |
| 2772 ** | |
| 2773 ** Requirements: | |
| 2774 ** [H13741] [H13742] [H13743] [H13744] [H13745] [H13746] [H13748] | |
| 2775 ** | |
| 2776 ** If two or more threads call one or more | |
| 2777 ** [sqlite3_column_database_name | column metadata interfaces] | |
| 2778 ** for the same [prepared statement] and result column | |
| 2779 ** at the same time then the results are undefined. | |
| 2780 */ | |
| 2781 const char *sqlite3_column_database_name(sqlite3_stmt*,int); | |
| 2782 const void *sqlite3_column_database_name16(sqlite3_stmt*,int); | |
| 2783 const char *sqlite3_column_table_name(sqlite3_stmt*,int); | |
| 2784 const void *sqlite3_column_table_name16(sqlite3_stmt*,int); | |
| 2785 const char *sqlite3_column_origin_name(sqlite3_stmt*,int); | |
| 2786 const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); | |
| 2787 | |
| 2788 /* | |
| 2789 ** CAPI3REF: Declared Datatype Of A Query Result {H13760} <S10700> | |
| 2790 ** | |
| 2791 ** The first parameter is a [prepared statement]. | |
| 2792 ** If this statement is a [SELECT] statement and the Nth column of the | |
| 2793 ** returned result set of that [SELECT] is a table column (not an | |
| 2794 ** expression or subquery) then the declared type of the table | |
| 2795 ** column is returned. If the Nth column of the result set is an | |
| 2796 ** expression or subquery, then a NULL pointer is returned. | |
| 2797 ** The returned string is always UTF-8 encoded. {END} | |
| 2798 ** | |
| 2799 ** For example, given the database schema: | |
| 2800 ** | |
| 2801 ** CREATE TABLE t1(c1 VARIANT); | |
| 2802 ** | |
| 2803 ** and the following statement to be compiled: | |
| 2804 ** | |
| 2805 ** SELECT c1 + 1, c1 FROM t1; | |
| 2806 ** | |
| 2807 ** this routine would return the string "VARIANT" for the second result | |
| 2808 ** column (i==1), and a NULL pointer for the first result column (i==0). | |
| 2809 ** | |
| 2810 ** SQLite uses dynamic run-time typing. So just because a column | |
| 2811 ** is declared to contain a particular type does not mean that the | |
| 2812 ** data stored in that column is of the declared type. SQLite is | |
| 2813 ** strongly typed, but the typing is dynamic not static. Type | |
| 2814 ** is associated with individual values, not with the containers | |
| 2815 ** used to hold those values. | |
| 2816 ** | |
| 2817 ** Requirements: | |
| 2818 ** [H13761] [H13762] [H13763] | |
| 2819 */ | |
| 2820 const char *sqlite3_column_decltype(sqlite3_stmt*,int); | |
| 2821 const void *sqlite3_column_decltype16(sqlite3_stmt*,int); | |
| 2822 | |
| 2823 /* | |
| 2824 ** CAPI3REF: Evaluate An SQL Statement {H13200} <S10000> | |
| 2825 ** | |
| 2826 ** After a [prepared statement] has been prepared using either | |
| 2827 ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy | |
| 2828 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function | |
| 2829 ** must be called one or more times to evaluate the statement. | |
| 2830 ** | |
| 2831 ** The details of the behavior of the sqlite3_step() interface depend | |
| 2832 ** on whether the statement was prepared using the newer "v2" interface | |
| 2833 ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy | |
| 2834 ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the | |
| 2835 ** new "v2" interface is recommended for new applications but the legacy | |
| 2836 ** interface will continue to be supported. | |
| 2837 ** | |
| 2838 ** In the legacy interface, the return value will be either [SQLITE_BUSY], | |
| 2839 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. | |
| 2840 ** With the "v2" interface, any of the other [result codes] or | |
| 2841 ** [extended result codes] might be returned as well. | |
| 2842 ** | |
| 2843 ** [SQLITE_BUSY] means that the database engine was unable to acquire the | |
| 2844 ** database locks it needs to do its job. If the statement is a [COMMIT] | |
| 2845 ** or occurs outside of an explicit transaction, then you can retry the | |
| 2846 ** statement. If the statement is not a [COMMIT] and occurs within a | |
| 2847 ** explicit transaction then you should rollback the transaction before | |
| 2848 ** continuing. | |
| 2849 ** | |
| 2850 ** [SQLITE_DONE] means that the statement has finished executing | |
| 2851 ** successfully. sqlite3_step() should not be called again on this virtual | |
| 2852 ** machine without first calling [sqlite3_reset()] to reset the virtual | |
| 2853 ** machine back to its initial state. | |
| 2854 ** | |
| 2855 ** If the SQL statement being executed returns any data, then [SQLITE_ROW] | |
| 2856 ** is returned each time a new row of data is ready for processing by the | |
| 2857 ** caller. The values may be accessed using the [column access functions]. | |
| 2858 ** sqlite3_step() is called again to retrieve the next row of data. | |
| 2859 ** | |
| 2860 ** [SQLITE_ERROR] means that a run-time error (such as a constraint | |
| 2861 ** violation) has occurred. sqlite3_step() should not be called again on | |
| 2862 ** the VM. More information may be found by calling [sqlite3_errmsg()]. | |
| 2863 ** With the legacy interface, a more specific error code (for example, | |
| 2864 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) | |
| 2865 ** can be obtained by calling [sqlite3_reset()] on the | |
| 2866 ** [prepared statement]. In the "v2" interface, | |
| 2867 ** the more specific error code is returned directly by sqlite3_step(). | |
| 2868 ** | |
| 2869 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. | |
| 2870 ** Perhaps it was called on a [prepared statement] that has | |
| 2871 ** already been [sqlite3_finalize | finalized] or on one that had | |
| 2872 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could | |
| 2873 ** be the case that the same database connection is being used by two or | |
| 2874 ** more threads at the same moment in time. | |
| 2875 ** | |
| 2876 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() | |
| 2877 ** API always returns a generic error code, [SQLITE_ERROR], following any | |
| 2878 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call | |
| 2879 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the | |
| 2880 ** specific [error codes] that better describes the error. | |
| 2881 ** We admit that this is a goofy design. The problem has been fixed | |
| 2882 ** with the "v2" interface. If you prepare all of your SQL statements | |
| 2883 ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead | |
| 2884 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, | |
| 2885 ** then the more specific [error codes] are returned directly | |
| 2886 ** by sqlite3_step(). The use of the "v2" interface is recommended. | |
| 2887 ** | |
| 2888 ** Requirements: | |
| 2889 ** [H13202] [H15304] [H15306] [H15308] [H15310] | |
| 2890 */ | |
| 2891 int sqlite3_step(sqlite3_stmt*); | |
| 2892 | |
| 2893 /* | |
| 2894 ** CAPI3REF: Number of columns in a result set {H13770} <S10700> | |
| 2895 ** | |
| 2896 ** Returns the number of values in the current row of the result set. | |
| 2897 ** | |
| 2898 ** Requirements: | |
| 2899 ** [H13771] [H13772] | |
| 2900 */ | |
| 2901 int sqlite3_data_count(sqlite3_stmt *pStmt); | |
| 2902 | |
| 2903 /* | |
| 2904 ** CAPI3REF: Fundamental Datatypes {H10265} <S10110><S10120> | |
| 2905 ** KEYWORDS: SQLITE_TEXT | |
| 2906 ** | |
| 2907 ** {H10266} Every value in SQLite has one of five fundamental datatypes: | |
| 2908 ** | |
| 2909 ** <ul> | |
| 2910 ** <li> 64-bit signed integer | |
| 2911 ** <li> 64-bit IEEE floating point number | |
| 2912 ** <li> string | |
| 2913 ** <li> BLOB | |
| 2914 ** <li> NULL | |
| 2915 ** </ul> {END} | |
| 2916 ** | |
| 2917 ** These constants are codes for each of those types. | |
| 2918 ** | |
| 2919 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 | |
| 2920 ** for a completely different meaning. Software that links against both | |
| 2921 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not | |
| 2922 ** SQLITE_TEXT. | |
| 2923 */ | |
| 2924 #define SQLITE_INTEGER 1 | |
| 2925 #define SQLITE_FLOAT 2 | |
| 2926 #define SQLITE_BLOB 4 | |
| 2927 #define SQLITE_NULL 5 | |
| 2928 #ifdef SQLITE_TEXT | |
| 2929 # undef SQLITE_TEXT | |
| 2930 #else | |
| 2931 # define SQLITE_TEXT 3 | |
| 2932 #endif | |
| 2933 #define SQLITE3_TEXT 3 | |
| 2934 | |
| 2935 /* | |
| 2936 ** CAPI3REF: Result Values From A Query {H13800} <S10700> | |
| 2937 ** KEYWORDS: {column access functions} | |
| 2938 ** | |
| 2939 ** These routines form the "result set query" interface. | |
| 2940 ** | |
| 2941 ** These routines return information about a single column of the current | |
| 2942 ** result row of a query. In every case the first argument is a pointer | |
| 2943 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] | |
| 2944 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) | |
| 2945 ** and the second argument is the index of the column for which information | |
| 2946 ** should be returned. The leftmost column of the result set has the index 0. | |
| 2947 ** | |
| 2948 ** If the SQL statement does not currently point to a valid row, or if the | |
| 2949 ** column index is out of range, the result is undefined. | |
| 2950 ** These routines may only be called when the most recent call to | |
| 2951 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither | |
| 2952 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. | |
| 2953 ** If any of these routines are called after [sqlite3_reset()] or | |
| 2954 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned | |
| 2955 ** something other than [SQLITE_ROW], the results are undefined. | |
| 2956 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] | |
| 2957 ** are called from a different thread while any of these routines | |
| 2958 ** are pending, then the results are undefined. | |
| 2959 ** | |
| 2960 ** The sqlite3_column_type() routine returns the | |
| 2961 ** [SQLITE_INTEGER | datatype code] for the initial data type | |
| 2962 ** of the result column. The returned value is one of [SQLITE_INTEGER], | |
| 2963 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value | |
| 2964 ** returned by sqlite3_column_type() is only meaningful if no type | |
| 2965 ** conversions have occurred as described below. After a type conversion, | |
| 2966 ** the value returned by sqlite3_column_type() is undefined. Future | |
| 2967 ** versions of SQLite may change the behavior of sqlite3_column_type() | |
| 2968 ** following a type conversion. | |
| 2969 ** | |
| 2970 ** If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() | |
| 2971 ** routine returns the number of bytes in that BLOB or string. | |
| 2972 ** If the result is a UTF-16 string, then sqlite3_column_bytes() converts | |
| 2973 ** the string to UTF-8 and then returns the number of bytes. | |
| 2974 ** If the result is a numeric value then sqlite3_column_bytes() uses | |
| 2975 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns | |
| 2976 ** the number of bytes in that string. | |
| 2977 ** The value returned does not include the zero terminator at the end | |
| 2978 ** of the string. For clarity: the value returned is the number of | |
| 2979 ** bytes in the string, not the number of characters. | |
| 2980 ** | |
| 2981 ** Strings returned by sqlite3_column_text() and sqlite3_column_text16(), | |
| 2982 ** even empty strings, are always zero terminated. The return | |
| 2983 ** value from sqlite3_column_blob() for a zero-length BLOB is an arbitrary | |
| 2984 ** pointer, possibly even a NULL pointer. | |
| 2985 ** | |
| 2986 ** The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes() | |
| 2987 ** but leaves the result in UTF-16 in native byte order instead of UTF-8. | |
| 2988 ** The zero terminator is not included in this count. | |
| 2989 ** | |
| 2990 ** The object returned by [sqlite3_column_value()] is an | |
| 2991 ** [unprotected sqlite3_value] object. An unprotected sqlite3_value object | |
| 2992 ** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. | |
| 2993 ** If the [unprotected sqlite3_value] object returned by | |
| 2994 ** [sqlite3_column_value()] is used in any other way, including calls | |
| 2995 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], | |
| 2996 ** or [sqlite3_value_bytes()], then the behavior is undefined. | |
| 2997 ** | |
| 2998 ** These routines attempt to convert the value where appropriate. For | |
| 2999 ** example, if the internal representation is FLOAT and a text result | |
| 3000 ** is requested, [sqlite3_snprintf()] is used internally to perform the | |
| 3001 ** conversion automatically. The following table details the conversions | |
| 3002 ** that are applied: | |
| 3003 ** | |
| 3004 ** <blockquote> | |
| 3005 ** <table border="1"> | |
| 3006 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion | |
| 3007 ** | |
| 3008 ** <tr><td> NULL <td> INTEGER <td> Result is 0 | |
| 3009 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 | |
| 3010 ** <tr><td> NULL <td> TEXT <td> Result is NULL pointer | |
| 3011 ** <tr><td> NULL <td> BLOB <td> Result is NULL pointer | |
| 3012 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float | |
| 3013 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer | |
| 3014 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT | |
| 3015 ** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer | |
| 3016 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float | |
| 3017 ** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT | |
| 3018 ** <tr><td> TEXT <td> INTEGER <td> Use atoi() | |
| 3019 ** <tr><td> TEXT <td> FLOAT <td> Use atof() | |
| 3020 ** <tr><td> TEXT <td> BLOB <td> No change | |
| 3021 ** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi() | |
| 3022 ** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof() | |
| 3023 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed | |
| 3024 ** </table> | |
| 3025 ** </blockquote> | |
| 3026 ** | |
| 3027 ** The table above makes reference to standard C library functions atoi() | |
| 3028 ** and atof(). SQLite does not really use these functions. It has its | |
| 3029 ** own equivalent internal routines. The atoi() and atof() names are | |
| 3030 ** used in the table for brevity and because they are familiar to most | |
| 3031 ** C programmers. | |
| 3032 ** | |
| 3033 ** Note that when type conversions occur, pointers returned by prior | |
| 3034 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or | |
| 3035 ** sqlite3_column_text16() may be invalidated. | |
| 3036 ** Type conversions and pointer invalidations might occur | |
| 3037 ** in the following cases: | |
| 3038 ** | |
| 3039 ** <ul> | |
| 3040 ** <li> The initial content is a BLOB and sqlite3_column_text() or | |
| 3041 ** sqlite3_column_text16() is called. A zero-terminator might | |
| 3042 ** need to be added to the string.</li> | |
| 3043 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or | |
| 3044 ** sqlite3_column_text16() is called. The content must be converted | |
| 3045 ** to UTF-16.</li> | |
| 3046 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or | |
| 3047 ** sqlite3_column_text() is called. The content must be converted | |
| 3048 ** to UTF-8.</li> | |
| 3049 ** </ul> | |
| 3050 ** | |
| 3051 ** Conversions between UTF-16be and UTF-16le are always done in place and do | |
| 3052 ** not invalidate a prior pointer, though of course the content of the buffer | |
| 3053 ** that the prior pointer points to will have been modified. Other kinds | |
| 3054 ** of conversion are done in place when it is possible, but sometimes they | |
| 3055 ** are not possible and in those cases prior pointers are invalidated. | |
| 3056 ** | |
| 3057 ** The safest and easiest to remember policy is to invoke these routines | |
| 3058 ** in one of the following ways: | |
| 3059 ** | |
| 3060 ** <ul> | |
| 3061 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> | |
| 3062 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> | |
| 3063 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> | |
| 3064 ** </ul> | |
| 3065 ** | |
| 3066 ** In other words, you should call sqlite3_column_text(), | |
| 3067 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result | |
| 3068 ** into the desired format, then invoke sqlite3_column_bytes() or | |
| 3069 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls | |
| 3070 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to | |
| 3071 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() | |
| 3072 ** with calls to sqlite3_column_bytes(). | |
| 3073 ** | |
| 3074 ** The pointers returned are valid until a type conversion occurs as | |
| 3075 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or | |
| 3076 ** [sqlite3_finalize()] is called. The memory space used to hold strings | |
| 3077 ** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned | |
| 3078 ** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into | |
| 3079 ** [sqlite3_free()]. | |
| 3080 ** | |
| 3081 ** If a memory allocation error occurs during the evaluation of any | |
| 3082 ** of these routines, a default value is returned. The default value | |
| 3083 ** is either the integer 0, the floating point number 0.0, or a NULL | |
| 3084 ** pointer. Subsequent calls to [sqlite3_errcode()] will return | |
| 3085 ** [SQLITE_NOMEM]. | |
| 3086 ** | |
| 3087 ** Requirements: | |
| 3088 ** [H13803] [H13806] [H13809] [H13812] [H13815] [H13818] [H13821] [H13824] | |
| 3089 ** [H13827] [H13830] | |
| 3090 */ | |
| 3091 const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); | |
| 3092 int sqlite3_column_bytes(sqlite3_stmt*, int iCol); | |
| 3093 int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); | |
| 3094 double sqlite3_column_double(sqlite3_stmt*, int iCol); | |
| 3095 int sqlite3_column_int(sqlite3_stmt*, int iCol); | |
| 3096 sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); | |
| 3097 const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); | |
| 3098 const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); | |
| 3099 int sqlite3_column_type(sqlite3_stmt*, int iCol); | |
| 3100 sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); | |
| 3101 | |
| 3102 /* | |
| 3103 ** CAPI3REF: Destroy A Prepared Statement Object {H13300} <S70300><S30100> | |
| 3104 ** | |
| 3105 ** The sqlite3_finalize() function is called to delete a [prepared statement]. | |
| 3106 ** If the statement was executed successfully or not executed at all, then | |
| 3107 ** SQLITE_OK is returned. If execution of the statement failed then an | |
| 3108 ** [error code] or [extended error code] is returned. | |
| 3109 ** | |
| 3110 ** This routine can be called at any point during the execution of the | |
| 3111 ** [prepared statement]. If the virtual machine has not | |
| 3112 ** completed execution when this routine is called, that is like | |
| 3113 ** encountering an error or an [sqlite3_interrupt | interrupt]. | |
| 3114 ** Incomplete updates may be rolled back and transactions canceled, | |
| 3115 ** depending on the circumstances, and the | |
| 3116 ** [error code] returned will be [SQLITE_ABORT]. | |
| 3117 ** | |
| 3118 ** Requirements: | |
| 3119 ** [H11302] [H11304] | |
| 3120 */ | |
| 3121 int sqlite3_finalize(sqlite3_stmt *pStmt); | |
| 3122 | |
| 3123 /* | |
| 3124 ** CAPI3REF: Reset A Prepared Statement Object {H13330} <S70300> | |
| 3125 ** | |
| 3126 ** The sqlite3_reset() function is called to reset a [prepared statement] | |
| 3127 ** object back to its initial state, ready to be re-executed. | |
| 3128 ** Any SQL statement variables that had values bound to them using | |
| 3129 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. | |
| 3130 ** Use [sqlite3_clear_bindings()] to reset the bindings. | |
| 3131 ** | |
| 3132 ** {H11332} The [sqlite3_reset(S)] interface resets the [prepared statement] S | |
| 3133 ** back to the beginning of its program. | |
| 3134 ** | |
| 3135 ** {H11334} If the most recent call to [sqlite3_step(S)] for the | |
| 3136 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], | |
| 3137 ** or if [sqlite3_step(S)] has never before been called on S, | |
| 3138 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. | |
| 3139 ** | |
| 3140 ** {H11336} If the most recent call to [sqlite3_step(S)] for the | |
| 3141 ** [prepared statement] S indicated an error, then | |
| 3142 ** [sqlite3_reset(S)] returns an appropriate [error code]. | |
| 3143 ** | |
| 3144 ** {H11338} The [sqlite3_reset(S)] interface does not change the values | |
| 3145 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. | |
| 3146 */ | |
| 3147 int sqlite3_reset(sqlite3_stmt *pStmt); | |
| 3148 | |
| 3149 /* | |
| 3150 ** CAPI3REF: Create Or Redefine SQL Functions {H16100} <S20200> | |
| 3151 ** KEYWORDS: {function creation routines} | |
| 3152 ** KEYWORDS: {application-defined SQL function} | |
| 3153 ** KEYWORDS: {application-defined SQL functions} | |
| 3154 ** | |
| 3155 ** These two functions (collectively known as "function creation routines") | |
| 3156 ** are used to add SQL functions or aggregates or to redefine the behavior | |
| 3157 ** of existing SQL functions or aggregates. The only difference between the | |
| 3158 ** two is that the second parameter, the name of the (scalar) function or | |
| 3159 ** aggregate, is encoded in UTF-8 for sqlite3_create_function() and UTF-16 | |
| 3160 ** for sqlite3_create_function16(). | |
| 3161 ** | |
| 3162 ** The first parameter is the [database connection] to which the SQL | |
| 3163 ** function is to be added. If a single program uses more than one database | |
| 3164 ** connection internally, then SQL functions must be added individually to | |
| 3165 ** each database connection. | |
| 3166 ** | |
| 3167 ** The second parameter is the name of the SQL function to be created or | |
| 3168 ** redefined. The length of the name is limited to 255 bytes, exclusive of | |
| 3169 ** the zero-terminator. Note that the name length limit is in bytes, not | |
| 3170 ** characters. Any attempt to create a function with a longer name | |
| 3171 ** will result in [SQLITE_ERROR] being returned. | |
| 3172 ** | |
| 3173 ** The third parameter (nArg) | |
| 3174 ** is the number of arguments that the SQL function or | |
| 3175 ** aggregate takes. If this parameter is -1, then the SQL function or | |
| 3176 ** aggregate may take any number of arguments between 0 and the limit | |
| 3177 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third | |
| 3178 ** parameter is less than -1 or greater than 127 then the behavior is | |
| 3179 ** undefined. | |
| 3180 ** | |
| 3181 ** The fourth parameter, eTextRep, specifies what | |
| 3182 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for | |
| 3183 ** its parameters. Any SQL function implementation should be able to work | |
| 3184 ** work with UTF-8, UTF-16le, or UTF-16be. But some implementations may be | |
| 3185 ** more efficient with one encoding than another. An application may | |
| 3186 ** invoke sqlite3_create_function() or sqlite3_create_function16() multiple | |
| 3187 ** times with the same function but with different values of eTextRep. | |
| 3188 ** When multiple implementations of the same function are available, SQLite | |
| 3189 ** will pick the one that involves the least amount of data conversion. | |
| 3190 ** If there is only a single implementation which does not care what text | |
| 3191 ** encoding is used, then the fourth argument should be [SQLITE_ANY]. | |
| 3192 ** | |
| 3193 ** The fifth parameter is an arbitrary pointer. The implementation of the | |
| 3194 ** function can gain access to this pointer using [sqlite3_user_data()]. | |
| 3195 ** | |
| 3196 ** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are | |
| 3197 ** pointers to C-language functions that implement the SQL function or | |
| 3198 ** aggregate. A scalar SQL function requires an implementation of the xFunc | |
| 3199 ** callback only, NULL pointers should be passed as the xStep and xFinal | |
| 3200 ** parameters. An aggregate SQL function requires an implementation of xStep | |
| 3201 ** and xFinal and NULL should be passed for xFunc. To delete an existing | |
| 3202 ** SQL function or aggregate, pass NULL for all three function callbacks. | |
| 3203 ** | |
| 3204 ** It is permitted to register multiple implementations of the same | |
| 3205 ** functions with the same name but with either differing numbers of | |
| 3206 ** arguments or differing preferred text encodings. SQLite will use | |
| 3207 ** the implementation that most closely matches the way in which the | |
| 3208 ** SQL function is used. A function implementation with a non-negative | |
| 3209 ** nArg parameter is a better match than a function implementation with | |
| 3210 ** a negative nArg. A function where the preferred text encoding | |
| 3211 ** matches the database encoding is a better | |
| 3212 ** match than a function where the encoding is different. | |
| 3213 ** A function where the encoding difference is between UTF16le and UTF16be | |
| 3214 ** is a closer match than a function where the encoding difference is | |
| 3215 ** between UTF8 and UTF16. | |
| 3216 ** | |
| 3217 ** Built-in functions may be overloaded by new application-defined functions. | |
| 3218 ** The first application-defined function with a given name overrides all | |
| 3219 ** built-in functions in the same [database connection] with the same name. | |
| 3220 ** Subsequent application-defined functions of the same name only override | |
| 3221 ** prior application-defined functions that are an exact match for the | |
| 3222 ** number of parameters and preferred encoding. | |
| 3223 ** | |
| 3224 ** An application-defined function is permitted to call other | |
| 3225 ** SQLite interfaces. However, such calls must not | |
| 3226 ** close the database connection nor finalize or reset the prepared | |
| 3227 ** statement in which the function is running. | |
| 3228 ** | |
| 3229 ** Requirements: | |
| 3230 ** [H16103] [H16106] [H16109] [H16112] [H16118] [H16121] [H16127] | |
| 3231 ** [H16130] [H16133] [H16136] [H16139] [H16142] | |
| 3232 */ | |
| 3233 int sqlite3_create_function( | |
| 3234 sqlite3 *db, | |
| 3235 const char *zFunctionName, | |
| 3236 int nArg, | |
| 3237 int eTextRep, | |
| 3238 void *pApp, | |
| 3239 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), | |
| 3240 void (*xStep)(sqlite3_context*,int,sqlite3_value**), | |
| 3241 void (*xFinal)(sqlite3_context*) | |
| 3242 ); | |
| 3243 int sqlite3_create_function16( | |
| 3244 sqlite3 *db, | |
| 3245 const void *zFunctionName, | |
| 3246 int nArg, | |
| 3247 int eTextRep, | |
| 3248 void *pApp, | |
| 3249 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), | |
| 3250 void (*xStep)(sqlite3_context*,int,sqlite3_value**), | |
| 3251 void (*xFinal)(sqlite3_context*) | |
| 3252 ); | |
| 3253 | |
| 3254 /* | |
| 3255 ** CAPI3REF: Text Encodings {H10267} <S50200> <H16100> | |
| 3256 ** | |
| 3257 ** These constant define integer codes that represent the various | |
| 3258 ** text encodings supported by SQLite. | |
| 3259 */ | |
| 3260 #define SQLITE_UTF8 1 | |
| 3261 #define SQLITE_UTF16LE 2 | |
| 3262 #define SQLITE_UTF16BE 3 | |
| 3263 #define SQLITE_UTF16 4 /* Use native byte order */ | |
| 3264 #define SQLITE_ANY 5 /* sqlite3_create_function only */ | |
| 3265 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ | |
| 3266 | |
| 3267 /* | |
| 3268 ** CAPI3REF: Deprecated Functions | |
| 3269 ** DEPRECATED | |
| 3270 ** | |
| 3271 ** These functions are [deprecated]. In order to maintain | |
| 3272 ** backwards compatibility with older code, these functions continue | |
| 3273 ** to be supported. However, new applications should avoid | |
| 3274 ** the use of these functions. To help encourage people to avoid | |
| 3275 ** using these functions, we are not going to tell you what they do. | |
| 3276 */ | |
| 3277 #ifndef SQLITE_OMIT_DEPRECATED | |
| 3278 SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); | |
| 3279 SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); | |
| 3280 SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); | |
| 3281 SQLITE_DEPRECATED int sqlite3_global_recover(void); | |
| 3282 SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); | |
| 3283 SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void
*,sqlite3_int64); | |
| 3284 #endif | |
| 3285 | |
| 3286 /* | |
| 3287 ** CAPI3REF: Obtaining SQL Function Parameter Values {H15100} <S20200> | |
| 3288 ** | |
| 3289 ** The C-language implementation of SQL functions and aggregates uses | |
| 3290 ** this set of interface routines to access the parameter values on | |
| 3291 ** the function or aggregate. | |
| 3292 ** | |
| 3293 ** The xFunc (for scalar functions) or xStep (for aggregates) parameters | |
| 3294 ** to [sqlite3_create_function()] and [sqlite3_create_function16()] | |
| 3295 ** define callbacks that implement the SQL functions and aggregates. | |
| 3296 ** The 4th parameter to these callbacks is an array of pointers to | |
| 3297 ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for | |
| 3298 ** each parameter to the SQL function. These routines are used to | |
| 3299 ** extract values from the [sqlite3_value] objects. | |
| 3300 ** | |
| 3301 ** These routines work only with [protected sqlite3_value] objects. | |
| 3302 ** Any attempt to use these routines on an [unprotected sqlite3_value] | |
| 3303 ** object results in undefined behavior. | |
| 3304 ** | |
| 3305 ** These routines work just like the corresponding [column access functions] | |
| 3306 ** except that these routines take a single [protected sqlite3_value] object | |
| 3307 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. | |
| 3308 ** | |
| 3309 ** The sqlite3_value_text16() interface extracts a UTF-16 string | |
| 3310 ** in the native byte-order of the host machine. The | |
| 3311 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces | |
| 3312 ** extract UTF-16 strings as big-endian and little-endian respectively. | |
| 3313 ** | |
| 3314 ** The sqlite3_value_numeric_type() interface attempts to apply | |
| 3315 ** numeric affinity to the value. This means that an attempt is | |
| 3316 ** made to convert the value to an integer or floating point. If | |
| 3317 ** such a conversion is possible without loss of information (in other | |
| 3318 ** words, if the value is a string that looks like a number) | |
| 3319 ** then the conversion is performed. Otherwise no conversion occurs. | |
| 3320 ** The [SQLITE_INTEGER | datatype] after conversion is returned. | |
| 3321 ** | |
| 3322 ** Please pay particular attention to the fact that the pointer returned | |
| 3323 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or | |
| 3324 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to | |
| 3325 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], | |
| 3326 ** or [sqlite3_value_text16()]. | |
| 3327 ** | |
| 3328 ** These routines must be called from the same thread as | |
| 3329 ** the SQL function that supplied the [sqlite3_value*] parameters. | |
| 3330 ** | |
| 3331 ** Requirements: | |
| 3332 ** [H15103] [H15106] [H15109] [H15112] [H15115] [H15118] [H15121] [H15124] | |
| 3333 ** [H15127] [H15130] [H15133] [H15136] | |
| 3334 */ | |
| 3335 const void *sqlite3_value_blob(sqlite3_value*); | |
| 3336 int sqlite3_value_bytes(sqlite3_value*); | |
| 3337 int sqlite3_value_bytes16(sqlite3_value*); | |
| 3338 double sqlite3_value_double(sqlite3_value*); | |
| 3339 int sqlite3_value_int(sqlite3_value*); | |
| 3340 sqlite3_int64 sqlite3_value_int64(sqlite3_value*); | |
| 3341 const unsigned char *sqlite3_value_text(sqlite3_value*); | |
| 3342 const void *sqlite3_value_text16(sqlite3_value*); | |
| 3343 const void *sqlite3_value_text16le(sqlite3_value*); | |
| 3344 const void *sqlite3_value_text16be(sqlite3_value*); | |
| 3345 int sqlite3_value_type(sqlite3_value*); | |
| 3346 int sqlite3_value_numeric_type(sqlite3_value*); | |
| 3347 | |
| 3348 /* | |
| 3349 ** CAPI3REF: Obtain Aggregate Function Context {H16210} <S20200> | |
| 3350 ** | |
| 3351 ** The implementation of aggregate SQL functions use this routine to allocate | |
| 3352 ** a structure for storing their state. | |
| 3353 ** | |
| 3354 ** The first time the sqlite3_aggregate_context() routine is called for a | |
| 3355 ** particular aggregate, SQLite allocates nBytes of memory, zeroes out that | |
| 3356 ** memory, and returns a pointer to it. On second and subsequent calls to | |
| 3357 ** sqlite3_aggregate_context() for the same aggregate function index, | |
| 3358 ** the same buffer is returned. The implementation of the aggregate can use | |
| 3359 ** the returned buffer to accumulate data. | |
| 3360 ** | |
| 3361 ** SQLite automatically frees the allocated buffer when the aggregate | |
| 3362 ** query concludes. | |
| 3363 ** | |
| 3364 ** The first parameter should be a copy of the | |
| 3365 ** [sqlite3_context | SQL function context] that is the first parameter | |
| 3366 ** to the callback routine that implements the aggregate function. | |
| 3367 ** | |
| 3368 ** This routine must be called from the same thread in which | |
| 3369 ** the aggregate SQL function is running. | |
| 3370 ** | |
| 3371 ** Requirements: | |
| 3372 ** [H16211] [H16213] [H16215] [H16217] | |
| 3373 */ | |
| 3374 void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); | |
| 3375 | |
| 3376 /* | |
| 3377 ** CAPI3REF: User Data For Functions {H16240} <S20200> | |
| 3378 ** | |
| 3379 ** The sqlite3_user_data() interface returns a copy of | |
| 3380 ** the pointer that was the pUserData parameter (the 5th parameter) | |
| 3381 ** of the [sqlite3_create_function()] | |
| 3382 ** and [sqlite3_create_function16()] routines that originally | |
| 3383 ** registered the application defined function. {END} | |
| 3384 ** | |
| 3385 ** This routine must be called from the same thread in which | |
| 3386 ** the application-defined function is running. | |
| 3387 ** | |
| 3388 ** Requirements: | |
| 3389 ** [H16243] | |
| 3390 */ | |
| 3391 void *sqlite3_user_data(sqlite3_context*); | |
| 3392 | |
| 3393 /* | |
| 3394 ** CAPI3REF: Database Connection For Functions {H16250} <S60600><S20200> | |
| 3395 ** | |
| 3396 ** The sqlite3_context_db_handle() interface returns a copy of | |
| 3397 ** the pointer to the [database connection] (the 1st parameter) | |
| 3398 ** of the [sqlite3_create_function()] | |
| 3399 ** and [sqlite3_create_function16()] routines that originally | |
| 3400 ** registered the application defined function. | |
| 3401 ** | |
| 3402 ** Requirements: | |
| 3403 ** [H16253] | |
| 3404 */ | |
| 3405 sqlite3 *sqlite3_context_db_handle(sqlite3_context*); | |
| 3406 | |
| 3407 /* | |
| 3408 ** CAPI3REF: Function Auxiliary Data {H16270} <S20200> | |
| 3409 ** | |
| 3410 ** The following two functions may be used by scalar SQL functions to | |
| 3411 ** associate metadata with argument values. If the same value is passed to | |
| 3412 ** multiple invocations of the same SQL function during query execution, under | |
| 3413 ** some circumstances the associated metadata may be preserved. This may | |
| 3414 ** be used, for example, to add a regular-expression matching scalar | |
| 3415 ** function. The compiled version of the regular expression is stored as | |
| 3416 ** metadata associated with the SQL value passed as the regular expression | |
| 3417 ** pattern. The compiled regular expression can be reused on multiple | |
| 3418 ** invocations of the same function so that the original pattern string | |
| 3419 ** does not need to be recompiled on each invocation. | |
| 3420 ** | |
| 3421 ** The sqlite3_get_auxdata() interface returns a pointer to the metadata | |
| 3422 ** associated by the sqlite3_set_auxdata() function with the Nth argument | |
| 3423 ** value to the application-defined function. If no metadata has been ever | |
| 3424 ** been set for the Nth argument of the function, or if the corresponding | |
| 3425 ** function parameter has changed since the meta-data was set, | |
| 3426 ** then sqlite3_get_auxdata() returns a NULL pointer. | |
| 3427 ** | |
| 3428 ** The sqlite3_set_auxdata() interface saves the metadata | |
| 3429 ** pointed to by its 3rd parameter as the metadata for the N-th | |
| 3430 ** argument of the application-defined function. Subsequent | |
| 3431 ** calls to sqlite3_get_auxdata() might return this data, if it has | |
| 3432 ** not been destroyed. | |
| 3433 ** If it is not NULL, SQLite will invoke the destructor | |
| 3434 ** function given by the 4th parameter to sqlite3_set_auxdata() on | |
| 3435 ** the metadata when the corresponding function parameter changes | |
| 3436 ** or when the SQL statement completes, whichever comes first. | |
| 3437 ** | |
| 3438 ** SQLite is free to call the destructor and drop metadata on any | |
| 3439 ** parameter of any function at any time. The only guarantee is that | |
| 3440 ** the destructor will be called before the metadata is dropped. | |
| 3441 ** | |
| 3442 ** In practice, metadata is preserved between function calls for | |
| 3443 ** expressions that are constant at compile time. This includes literal | |
| 3444 ** values and SQL variables. | |
| 3445 ** | |
| 3446 ** These routines must be called from the same thread in which | |
| 3447 ** the SQL function is running. | |
| 3448 ** | |
| 3449 ** Requirements: | |
| 3450 ** [H16272] [H16274] [H16276] [H16277] [H16278] [H16279] | |
| 3451 */ | |
| 3452 void *sqlite3_get_auxdata(sqlite3_context*, int N); | |
| 3453 void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); | |
| 3454 | |
| 3455 | |
| 3456 /* | |
| 3457 ** CAPI3REF: Constants Defining Special Destructor Behavior {H10280} <S30100> | |
| 3458 ** | |
| 3459 ** These are special values for the destructor that is passed in as the | |
| 3460 ** final argument to routines like [sqlite3_result_blob()]. If the destructor | |
| 3461 ** argument is SQLITE_STATIC, it means that the content pointer is constant | |
| 3462 ** and will never change. It does not need to be destroyed. The | |
| 3463 ** SQLITE_TRANSIENT value means that the content will likely change in | |
| 3464 ** the near future and that SQLite should make its own private copy of | |
| 3465 ** the content before returning. | |
| 3466 ** | |
| 3467 ** The typedef is necessary to work around problems in certain | |
| 3468 ** C++ compilers. See ticket #2191. | |
| 3469 */ | |
| 3470 typedef void (*sqlite3_destructor_type)(void*); | |
| 3471 #define SQLITE_STATIC ((sqlite3_destructor_type)0) | |
| 3472 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) | |
| 3473 | |
| 3474 /* | |
| 3475 ** CAPI3REF: Setting The Result Of An SQL Function {H16400} <S20200> | |
| 3476 ** | |
| 3477 ** These routines are used by the xFunc or xFinal callbacks that | |
| 3478 ** implement SQL functions and aggregates. See | |
| 3479 ** [sqlite3_create_function()] and [sqlite3_create_function16()] | |
| 3480 ** for additional information. | |
| 3481 ** | |
| 3482 ** These functions work very much like the [parameter binding] family of | |
| 3483 ** functions used to bind values to host parameters in prepared statements. | |
| 3484 ** Refer to the [SQL parameter] documentation for additional information. | |
| 3485 ** | |
| 3486 ** The sqlite3_result_blob() interface sets the result from | |
| 3487 ** an application-defined function to be the BLOB whose content is pointed | |
| 3488 ** to by the second parameter and which is N bytes long where N is the | |
| 3489 ** third parameter. | |
| 3490 ** | |
| 3491 ** The sqlite3_result_zeroblob() interfaces set the result of | |
| 3492 ** the application-defined function to be a BLOB containing all zero | |
| 3493 ** bytes and N bytes in size, where N is the value of the 2nd parameter. | |
| 3494 ** | |
| 3495 ** The sqlite3_result_double() interface sets the result from | |
| 3496 ** an application-defined function to be a floating point value specified | |
| 3497 ** by its 2nd argument. | |
| 3498 ** | |
| 3499 ** The sqlite3_result_error() and sqlite3_result_error16() functions | |
| 3500 ** cause the implemented SQL function to throw an exception. | |
| 3501 ** SQLite uses the string pointed to by the | |
| 3502 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() | |
| 3503 ** as the text of an error message. SQLite interprets the error | |
| 3504 ** message string from sqlite3_result_error() as UTF-8. SQLite | |
| 3505 ** interprets the string from sqlite3_result_error16() as UTF-16 in native | |
| 3506 ** byte order. If the third parameter to sqlite3_result_error() | |
| 3507 ** or sqlite3_result_error16() is negative then SQLite takes as the error | |
| 3508 ** message all text up through the first zero character. | |
| 3509 ** If the third parameter to sqlite3_result_error() or | |
| 3510 ** sqlite3_result_error16() is non-negative then SQLite takes that many | |
| 3511 ** bytes (not characters) from the 2nd parameter as the error message. | |
| 3512 ** The sqlite3_result_error() and sqlite3_result_error16() | |
| 3513 ** routines make a private copy of the error message text before | |
| 3514 ** they return. Hence, the calling function can deallocate or | |
| 3515 ** modify the text after they return without harm. | |
| 3516 ** The sqlite3_result_error_code() function changes the error code | |
| 3517 ** returned by SQLite as a result of an error in a function. By default, | |
| 3518 ** the error code is SQLITE_ERROR. A subsequent call to sqlite3_result_error() | |
| 3519 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. | |
| 3520 ** | |
| 3521 ** The sqlite3_result_toobig() interface causes SQLite to throw an error | |
| 3522 ** indicating that a string or BLOB is to long to represent. | |
| 3523 ** | |
| 3524 ** The sqlite3_result_nomem() interface causes SQLite to throw an error | |
| 3525 ** indicating that a memory allocation failed. | |
| 3526 ** | |
| 3527 ** The sqlite3_result_int() interface sets the return value | |
| 3528 ** of the application-defined function to be the 32-bit signed integer | |
| 3529 ** value given in the 2nd argument. | |
| 3530 ** The sqlite3_result_int64() interface sets the return value | |
| 3531 ** of the application-defined function to be the 64-bit signed integer | |
| 3532 ** value given in the 2nd argument. | |
| 3533 ** | |
| 3534 ** The sqlite3_result_null() interface sets the return value | |
| 3535 ** of the application-defined function to be NULL. | |
| 3536 ** | |
| 3537 ** The sqlite3_result_text(), sqlite3_result_text16(), | |
| 3538 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces | |
| 3539 ** set the return value of the application-defined function to be | |
| 3540 ** a text string which is represented as UTF-8, UTF-16 native byte order, | |
| 3541 ** UTF-16 little endian, or UTF-16 big endian, respectively. | |
| 3542 ** SQLite takes the text result from the application from | |
| 3543 ** the 2nd parameter of the sqlite3_result_text* interfaces. | |
| 3544 ** If the 3rd parameter to the sqlite3_result_text* interfaces | |
| 3545 ** is negative, then SQLite takes result text from the 2nd parameter | |
| 3546 ** through the first zero character. | |
| 3547 ** If the 3rd parameter to the sqlite3_result_text* interfaces | |
| 3548 ** is non-negative, then as many bytes (not characters) of the text | |
| 3549 ** pointed to by the 2nd parameter are taken as the application-defined | |
| 3550 ** function result. | |
| 3551 ** If the 4th parameter to the sqlite3_result_text* interfaces | |
| 3552 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that | |
| 3553 ** function as the destructor on the text or BLOB result when it has | |
| 3554 ** finished using that result. | |
| 3555 ** If the 4th parameter to the sqlite3_result_text* interfaces or to | |
| 3556 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite | |
| 3557 ** assumes that the text or BLOB result is in constant space and does not | |
| 3558 ** copy the content of the parameter nor call a destructor on the content | |
| 3559 ** when it has finished using that result. | |
| 3560 ** If the 4th parameter to the sqlite3_result_text* interfaces | |
| 3561 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT | |
| 3562 ** then SQLite makes a copy of the result into space obtained from | |
| 3563 ** from [sqlite3_malloc()] before it returns. | |
| 3564 ** | |
| 3565 ** The sqlite3_result_value() interface sets the result of | |
| 3566 ** the application-defined function to be a copy the | |
| 3567 ** [unprotected sqlite3_value] object specified by the 2nd parameter. The | |
| 3568 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] | |
| 3569 ** so that the [sqlite3_value] specified in the parameter may change or | |
| 3570 ** be deallocated after sqlite3_result_value() returns without harm. | |
| 3571 ** A [protected sqlite3_value] object may always be used where an | |
| 3572 ** [unprotected sqlite3_value] object is required, so either | |
| 3573 ** kind of [sqlite3_value] object can be used with this interface. | |
| 3574 ** | |
| 3575 ** If these routines are called from within the different thread | |
| 3576 ** than the one containing the application-defined function that received | |
| 3577 ** the [sqlite3_context] pointer, the results are undefined. | |
| 3578 ** | |
| 3579 ** Requirements: | |
| 3580 ** [H16403] [H16406] [H16409] [H16412] [H16415] [H16418] [H16421] [H16424] | |
| 3581 ** [H16427] [H16430] [H16433] [H16436] [H16439] [H16442] [H16445] [H16448] | |
| 3582 ** [H16451] [H16454] [H16457] [H16460] [H16463] | |
| 3583 */ | |
| 3584 void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); | |
| 3585 void sqlite3_result_double(sqlite3_context*, double); | |
| 3586 void sqlite3_result_error(sqlite3_context*, const char*, int); | |
| 3587 void sqlite3_result_error16(sqlite3_context*, const void*, int); | |
| 3588 void sqlite3_result_error_toobig(sqlite3_context*); | |
| 3589 void sqlite3_result_error_nomem(sqlite3_context*); | |
| 3590 void sqlite3_result_error_code(sqlite3_context*, int); | |
| 3591 void sqlite3_result_int(sqlite3_context*, int); | |
| 3592 void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); | |
| 3593 void sqlite3_result_null(sqlite3_context*); | |
| 3594 void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); | |
| 3595 void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); | |
| 3596 void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); | |
| 3597 void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); | |
| 3598 void sqlite3_result_value(sqlite3_context*, sqlite3_value*); | |
| 3599 void sqlite3_result_zeroblob(sqlite3_context*, int n); | |
| 3600 | |
| 3601 /* | |
| 3602 ** CAPI3REF: Define New Collating Sequences {H16600} <S20300> | |
| 3603 ** | |
| 3604 ** These functions are used to add new collation sequences to the | |
| 3605 ** [database connection] specified as the first argument. | |
| 3606 ** | |
| 3607 ** The name of the new collation sequence is specified as a UTF-8 string | |
| 3608 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() | |
| 3609 ** and a UTF-16 string for sqlite3_create_collation16(). In all cases | |
| 3610 ** the name is passed as the second function argument. | |
| 3611 ** | |
| 3612 ** The third argument may be one of the constants [SQLITE_UTF8], | |
| 3613 ** [SQLITE_UTF16LE], or [SQLITE_UTF16BE], indicating that the user-supplied | |
| 3614 ** routine expects to be passed pointers to strings encoded using UTF-8, | |
| 3615 ** UTF-16 little-endian, or UTF-16 big-endian, respectively. The | |
| 3616 ** third argument might also be [SQLITE_UTF16] to indicate that the routine | |
| 3617 ** expects pointers to be UTF-16 strings in the native byte order, or the | |
| 3618 ** argument can be [SQLITE_UTF16_ALIGNED] if the | |
| 3619 ** the routine expects pointers to 16-bit word aligned strings | |
| 3620 ** of UTF-16 in the native byte order. | |
| 3621 ** | |
| 3622 ** A pointer to the user supplied routine must be passed as the fifth | |
| 3623 ** argument. If it is NULL, this is the same as deleting the collation | |
| 3624 ** sequence (so that SQLite cannot call it anymore). | |
| 3625 ** Each time the application supplied function is invoked, it is passed | |
| 3626 ** as its first parameter a copy of the void* passed as the fourth argument | |
| 3627 ** to sqlite3_create_collation() or sqlite3_create_collation16(). | |
| 3628 ** | |
| 3629 ** The remaining arguments to the application-supplied routine are two strings, | |
| 3630 ** each represented by a (length, data) pair and encoded in the encoding | |
| 3631 ** that was passed as the third argument when the collation sequence was | |
| 3632 ** registered. {END} The application defined collation routine should | |
| 3633 ** return negative, zero or positive if the first string is less than, | |
| 3634 ** equal to, or greater than the second string. i.e. (STRING1 - STRING2). | |
| 3635 ** | |
| 3636 ** The sqlite3_create_collation_v2() works like sqlite3_create_collation() | |
| 3637 ** except that it takes an extra argument which is a destructor for | |
| 3638 ** the collation. The destructor is called when the collation is | |
| 3639 ** destroyed and is passed a copy of the fourth parameter void* pointer | |
| 3640 ** of the sqlite3_create_collation_v2(). | |
| 3641 ** Collations are destroyed when they are overridden by later calls to the | |
| 3642 ** collation creation functions or when the [database connection] is closed | |
| 3643 ** using [sqlite3_close()]. | |
| 3644 ** | |
| 3645 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. | |
| 3646 ** | |
| 3647 ** Requirements: | |
| 3648 ** [H16603] [H16604] [H16606] [H16609] [H16612] [H16615] [H16618] [H16621] | |
| 3649 ** [H16624] [H16627] [H16630] | |
| 3650 */ | |
| 3651 int sqlite3_create_collation( | |
| 3652 sqlite3*, | |
| 3653 const char *zName, | |
| 3654 int eTextRep, | |
| 3655 void*, | |
| 3656 int(*xCompare)(void*,int,const void*,int,const void*) | |
| 3657 ); | |
| 3658 int sqlite3_create_collation_v2( | |
| 3659 sqlite3*, | |
| 3660 const char *zName, | |
| 3661 int eTextRep, | |
| 3662 void*, | |
| 3663 int(*xCompare)(void*,int,const void*,int,const void*), | |
| 3664 void(*xDestroy)(void*) | |
| 3665 ); | |
| 3666 int sqlite3_create_collation16( | |
| 3667 sqlite3*, | |
| 3668 const void *zName, | |
| 3669 int eTextRep, | |
| 3670 void*, | |
| 3671 int(*xCompare)(void*,int,const void*,int,const void*) | |
| 3672 ); | |
| 3673 | |
| 3674 /* | |
| 3675 ** CAPI3REF: Collation Needed Callbacks {H16700} <S20300> | |
| 3676 ** | |
| 3677 ** To avoid having to register all collation sequences before a database | |
| 3678 ** can be used, a single callback function may be registered with the | |
| 3679 ** [database connection] to be called whenever an undefined collation | |
| 3680 ** sequence is required. | |
| 3681 ** | |
| 3682 ** If the function is registered using the sqlite3_collation_needed() API, | |
| 3683 ** then it is passed the names of undefined collation sequences as strings | |
| 3684 ** encoded in UTF-8. {H16703} If sqlite3_collation_needed16() is used, | |
| 3685 ** the names are passed as UTF-16 in machine native byte order. | |
| 3686 ** A call to either function replaces any existing callback. | |
| 3687 ** | |
| 3688 ** When the callback is invoked, the first argument passed is a copy | |
| 3689 ** of the second argument to sqlite3_collation_needed() or | |
| 3690 ** sqlite3_collation_needed16(). The second argument is the database | |
| 3691 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], | |
| 3692 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation | |
| 3693 ** sequence function required. The fourth parameter is the name of the | |
| 3694 ** required collation sequence. | |
| 3695 ** | |
| 3696 ** The callback function should register the desired collation using | |
| 3697 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or | |
| 3698 ** [sqlite3_create_collation_v2()]. | |
| 3699 ** | |
| 3700 ** Requirements: | |
| 3701 ** [H16702] [H16704] [H16706] | |
| 3702 */ | |
| 3703 int sqlite3_collation_needed( | |
| 3704 sqlite3*, | |
| 3705 void*, | |
| 3706 void(*)(void*,sqlite3*,int eTextRep,const char*) | |
| 3707 ); | |
| 3708 int sqlite3_collation_needed16( | |
| 3709 sqlite3*, | |
| 3710 void*, | |
| 3711 void(*)(void*,sqlite3*,int eTextRep,const void*) | |
| 3712 ); | |
| 3713 | |
| 3714 /* | |
| 3715 ** Specify the key for an encrypted database. This routine should be | |
| 3716 ** called right after sqlite3_open(). | |
| 3717 ** | |
| 3718 ** The code to implement this API is not available in the public release | |
| 3719 ** of SQLite. | |
| 3720 */ | |
| 3721 int sqlite3_key( | |
| 3722 sqlite3 *db, /* Database to be rekeyed */ | |
| 3723 const void *pKey, int nKey /* The key */ | |
| 3724 ); | |
| 3725 | |
| 3726 /* | |
| 3727 ** Change the key on an open database. If the current database is not | |
| 3728 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the | |
| 3729 ** database is decrypted. | |
| 3730 ** | |
| 3731 ** The code to implement this API is not available in the public release | |
| 3732 ** of SQLite. | |
| 3733 */ | |
| 3734 int sqlite3_rekey( | |
| 3735 sqlite3 *db, /* Database to be rekeyed */ | |
| 3736 const void *pKey, int nKey /* The new key */ | |
| 3737 ); | |
| 3738 | |
| 3739 /* | |
| 3740 ** CAPI3REF: Suspend Execution For A Short Time {H10530} <S40410> | |
| 3741 ** | |
| 3742 ** The sqlite3_sleep() function causes the current thread to suspend execution | |
| 3743 ** for at least a number of milliseconds specified in its parameter. | |
| 3744 ** | |
| 3745 ** If the operating system does not support sleep requests with | |
| 3746 ** millisecond time resolution, then the time will be rounded up to | |
| 3747 ** the nearest second. The number of milliseconds of sleep actually | |
| 3748 ** requested from the operating system is returned. | |
| 3749 ** | |
| 3750 ** SQLite implements this interface by calling the xSleep() | |
| 3751 ** method of the default [sqlite3_vfs] object. | |
| 3752 ** | |
| 3753 ** Requirements: [H10533] [H10536] | |
| 3754 */ | |
| 3755 int sqlite3_sleep(int); | |
| 3756 | |
| 3757 /* | |
| 3758 ** CAPI3REF: Name Of The Folder Holding Temporary Files {H10310} <S20000> | |
| 3759 ** | |
| 3760 ** If this global variable is made to point to a string which is | |
| 3761 ** the name of a folder (a.k.a. directory), then all temporary files | |
| 3762 ** created by SQLite will be placed in that directory. If this variable | |
| 3763 ** is a NULL pointer, then SQLite performs a search for an appropriate | |
| 3764 ** temporary file directory. | |
| 3765 ** | |
| 3766 ** It is not safe to read or modify this variable in more than one | |
| 3767 ** thread at a time. It is not safe to read or modify this variable | |
| 3768 ** if a [database connection] is being used at the same time in a separate | |
| 3769 ** thread. | |
| 3770 ** It is intended that this variable be set once | |
| 3771 ** as part of process initialization and before any SQLite interface | |
| 3772 ** routines have been called and that this variable remain unchanged | |
| 3773 ** thereafter. | |
| 3774 ** | |
| 3775 ** The [temp_store_directory pragma] may modify this variable and cause | |
| 3776 ** it to point to memory obtained from [sqlite3_malloc]. Furthermore, | |
| 3777 ** the [temp_store_directory pragma] always assumes that any string | |
| 3778 ** that this variable points to is held in memory obtained from | |
| 3779 ** [sqlite3_malloc] and the pragma may attempt to free that memory | |
| 3780 ** using [sqlite3_free]. | |
| 3781 ** Hence, if this variable is modified directly, either it should be | |
| 3782 ** made NULL or made to point to memory obtained from [sqlite3_malloc] | |
| 3783 ** or else the use of the [temp_store_directory pragma] should be avoided. | |
| 3784 */ | |
| 3785 SQLITE_EXTERN char *sqlite3_temp_directory; | |
| 3786 | |
| 3787 /* | |
| 3788 ** CAPI3REF: Test For Auto-Commit Mode {H12930} <S60200> | |
| 3789 ** KEYWORDS: {autocommit mode} | |
| 3790 ** | |
| 3791 ** The sqlite3_get_autocommit() interface returns non-zero or | |
| 3792 ** zero if the given database connection is or is not in autocommit mode, | |
| 3793 ** respectively. Autocommit mode is on by default. | |
| 3794 ** Autocommit mode is disabled by a [BEGIN] statement. | |
| 3795 ** Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. | |
| 3796 ** | |
| 3797 ** If certain kinds of errors occur on a statement within a multi-statement | |
| 3798 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], | |
| 3799 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the | |
| 3800 ** transaction might be rolled back automatically. The only way to | |
| 3801 ** find out whether SQLite automatically rolled back the transaction after | |
| 3802 ** an error is to use this function. | |
| 3803 ** | |
| 3804 ** If another thread changes the autocommit status of the database | |
| 3805 ** connection while this routine is running, then the return value | |
| 3806 ** is undefined. | |
| 3807 ** | |
| 3808 ** Requirements: [H12931] [H12932] [H12933] [H12934] | |
| 3809 */ | |
| 3810 int sqlite3_get_autocommit(sqlite3*); | |
| 3811 | |
| 3812 /* | |
| 3813 ** CAPI3REF: Find The Database Handle Of A Prepared Statement {H13120} <S60600> | |
| 3814 ** | |
| 3815 ** The sqlite3_db_handle interface returns the [database connection] handle | |
| 3816 ** to which a [prepared statement] belongs. The [database connection] | |
| 3817 ** returned by sqlite3_db_handle is the same [database connection] that was the
first argument | |
| 3818 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to | |
| 3819 ** create the statement in the first place. | |
| 3820 ** | |
| 3821 ** Requirements: [H13123] | |
| 3822 */ | |
| 3823 sqlite3 *sqlite3_db_handle(sqlite3_stmt*); | |
| 3824 | |
| 3825 /* | |
| 3826 ** CAPI3REF: Find the next prepared statement {H13140} <S60600> | |
| 3827 ** | |
| 3828 ** This interface returns a pointer to the next [prepared statement] after | |
| 3829 ** pStmt associated with the [database connection] pDb. If pStmt is NULL | |
| 3830 ** then this interface returns a pointer to the first prepared statement | |
| 3831 ** associated with the database connection pDb. If no prepared statement | |
| 3832 ** satisfies the conditions of this routine, it returns NULL. | |
| 3833 ** | |
| 3834 ** The [database connection] pointer D in a call to | |
| 3835 ** [sqlite3_next_stmt(D,S)] must refer to an open database | |
| 3836 ** connection and in particular must not be a NULL pointer. | |
| 3837 ** | |
| 3838 ** Requirements: [H13143] [H13146] [H13149] [H13152] | |
| 3839 */ | |
| 3840 sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); | |
| 3841 | |
| 3842 /* | |
| 3843 ** CAPI3REF: Commit And Rollback Notification Callbacks {H12950} <S60400> | |
| 3844 ** | |
| 3845 ** The sqlite3_commit_hook() interface registers a callback | |
| 3846 ** function to be invoked whenever a transaction is [COMMIT | committed]. | |
| 3847 ** Any callback set by a previous call to sqlite3_commit_hook() | |
| 3848 ** for the same database connection is overridden. | |
| 3849 ** The sqlite3_rollback_hook() interface registers a callback | |
| 3850 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. | |
| 3851 ** Any callback set by a previous call to sqlite3_commit_hook() | |
| 3852 ** for the same database connection is overridden. | |
| 3853 ** The pArg argument is passed through to the callback. | |
| 3854 ** If the callback on a commit hook function returns non-zero, | |
| 3855 ** then the commit is converted into a rollback. | |
| 3856 ** | |
| 3857 ** If another function was previously registered, its | |
| 3858 ** pArg value is returned. Otherwise NULL is returned. | |
| 3859 ** | |
| 3860 ** The callback implementation must not do anything that will modify | |
| 3861 ** the database connection that invoked the callback. Any actions | |
| 3862 ** to modify the database connection must be deferred until after the | |
| 3863 ** completion of the [sqlite3_step()] call that triggered the commit | |
| 3864 ** or rollback hook in the first place. | |
| 3865 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their | |
| 3866 ** database connections for the meaning of "modify" in this paragraph. | |
| 3867 ** | |
| 3868 ** Registering a NULL function disables the callback. | |
| 3869 ** | |
| 3870 ** When the commit hook callback routine returns zero, the [COMMIT] | |
| 3871 ** operation is allowed to continue normally. If the commit hook | |
| 3872 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. | |
| 3873 ** The rollback hook is invoked on a rollback that results from a commit | |
| 3874 ** hook returning non-zero, just as it would be with any other rollback. | |
| 3875 ** | |
| 3876 ** For the purposes of this API, a transaction is said to have been | |
| 3877 ** rolled back if an explicit "ROLLBACK" statement is executed, or | |
| 3878 ** an error or constraint causes an implicit rollback to occur. | |
| 3879 ** The rollback callback is not invoked if a transaction is | |
| 3880 ** automatically rolled back because the database connection is closed. | |
| 3881 ** The rollback callback is not invoked if a transaction is | |
| 3882 ** rolled back because a commit callback returned non-zero. | |
| 3883 ** <todo> Check on this </todo> | |
| 3884 ** | |
| 3885 ** See also the [sqlite3_update_hook()] interface. | |
| 3886 ** | |
| 3887 ** Requirements: | |
| 3888 ** [H12951] [H12952] [H12953] [H12954] [H12955] | |
| 3889 ** [H12961] [H12962] [H12963] [H12964] | |
| 3890 */ | |
| 3891 void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); | |
| 3892 void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); | |
| 3893 | |
| 3894 /* | |
| 3895 ** CAPI3REF: Data Change Notification Callbacks {H12970} <S60400> | |
| 3896 ** | |
| 3897 ** The sqlite3_update_hook() interface registers a callback function | |
| 3898 ** with the [database connection] identified by the first argument | |
| 3899 ** to be invoked whenever a row is updated, inserted or deleted. | |
| 3900 ** Any callback set by a previous call to this function | |
| 3901 ** for the same database connection is overridden. | |
| 3902 ** | |
| 3903 ** The second argument is a pointer to the function to invoke when a | |
| 3904 ** row is updated, inserted or deleted. | |
| 3905 ** The first argument to the callback is a copy of the third argument | |
| 3906 ** to sqlite3_update_hook(). | |
| 3907 ** The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], | |
| 3908 ** or [SQLITE_UPDATE], depending on the operation that caused the callback | |
| 3909 ** to be invoked. | |
| 3910 ** The third and fourth arguments to the callback contain pointers to the | |
| 3911 ** database and table name containing the affected row. | |
| 3912 ** The final callback parameter is the [rowid] of the row. | |
| 3913 ** In the case of an update, this is the [rowid] after the update takes place. | |
| 3914 ** | |
| 3915 ** The update hook is not invoked when internal system tables are | |
| 3916 ** modified (i.e. sqlite_master and sqlite_sequence). | |
| 3917 ** | |
| 3918 ** In the current implementation, the update hook | |
| 3919 ** is not invoked when duplication rows are deleted because of an | |
| 3920 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. Nor is the update hook | |
| 3921 ** invoked when rows are deleted using the [truncate optimization]. | |
| 3922 ** The exceptions defined in this paragraph might change in a future | |
| 3923 ** release of SQLite. | |
| 3924 ** | |
| 3925 ** The update hook implementation must not do anything that will modify | |
| 3926 ** the database connection that invoked the update hook. Any actions | |
| 3927 ** to modify the database connection must be deferred until after the | |
| 3928 ** completion of the [sqlite3_step()] call that triggered the update hook. | |
| 3929 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their | |
| 3930 ** database connections for the meaning of "modify" in this paragraph. | |
| 3931 ** | |
| 3932 ** If another function was previously registered, its pArg value | |
| 3933 ** is returned. Otherwise NULL is returned. | |
| 3934 ** | |
| 3935 ** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] | |
| 3936 ** interfaces. | |
| 3937 ** | |
| 3938 ** Requirements: | |
| 3939 ** [H12971] [H12973] [H12975] [H12977] [H12979] [H12981] [H12983] [H12986] | |
| 3940 */ | |
| 3941 void *sqlite3_update_hook( | |
| 3942 sqlite3*, | |
| 3943 void(*)(void *,int ,char const *,char const *,sqlite3_int64), | |
| 3944 void* | |
| 3945 ); | |
| 3946 | |
| 3947 /* | |
| 3948 ** CAPI3REF: Enable Or Disable Shared Pager Cache {H10330} <S30900> | |
| 3949 ** KEYWORDS: {shared cache} | |
| 3950 ** | |
| 3951 ** This routine enables or disables the sharing of the database cache | |
| 3952 ** and schema data structures between [database connection | connections] | |
| 3953 ** to the same database. Sharing is enabled if the argument is true | |
| 3954 ** and disabled if the argument is false. | |
| 3955 ** | |
| 3956 ** Cache sharing is enabled and disabled for an entire process. | |
| 3957 ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, | |
| 3958 ** sharing was enabled or disabled for each thread separately. | |
| 3959 ** | |
| 3960 ** The cache sharing mode set by this interface effects all subsequent | |
| 3961 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. | |
| 3962 ** Existing database connections continue use the sharing mode | |
| 3963 ** that was in effect at the time they were opened. | |
| 3964 ** | |
| 3965 ** Virtual tables cannot be used with a shared cache. When shared | |
| 3966 ** cache is enabled, the [sqlite3_create_module()] API used to register | |
| 3967 ** virtual tables will always return an error. | |
| 3968 ** | |
| 3969 ** This routine returns [SQLITE_OK] if shared cache was enabled or disabled | |
| 3970 ** successfully. An [error code] is returned otherwise. | |
| 3971 ** | |
| 3972 ** Shared cache is disabled by default. But this might change in | |
| 3973 ** future releases of SQLite. Applications that care about shared | |
| 3974 ** cache setting should set it explicitly. | |
| 3975 ** | |
| 3976 ** See Also: [SQLite Shared-Cache Mode] | |
| 3977 ** | |
| 3978 ** Requirements: [H10331] [H10336] [H10337] [H10339] | |
| 3979 */ | |
| 3980 int sqlite3_enable_shared_cache(int); | |
| 3981 | |
| 3982 /* | |
| 3983 ** CAPI3REF: Attempt To Free Heap Memory {H17340} <S30220> | |
| 3984 ** | |
| 3985 ** The sqlite3_release_memory() interface attempts to free N bytes | |
| 3986 ** of heap memory by deallocating non-essential memory allocations | |
| 3987 ** held by the database library. {END} Memory used to cache database | |
| 3988 ** pages to improve performance is an example of non-essential memory. | |
| 3989 ** sqlite3_release_memory() returns the number of bytes actually freed, | |
| 3990 ** which might be more or less than the amount requested. | |
| 3991 ** | |
| 3992 ** Requirements: [H17341] [H17342] | |
| 3993 */ | |
| 3994 int sqlite3_release_memory(int); | |
| 3995 | |
| 3996 /* | |
| 3997 ** CAPI3REF: Impose A Limit On Heap Size {H17350} <S30220> | |
| 3998 ** | |
| 3999 ** The sqlite3_soft_heap_limit() interface places a "soft" limit | |
| 4000 ** on the amount of heap memory that may be allocated by SQLite. | |
| 4001 ** If an internal allocation is requested that would exceed the | |
| 4002 ** soft heap limit, [sqlite3_release_memory()] is invoked one or | |
| 4003 ** more times to free up some space before the allocation is performed. | |
| 4004 ** | |
| 4005 ** The limit is called "soft", because if [sqlite3_release_memory()] | |
| 4006 ** cannot free sufficient memory to prevent the limit from being exceeded, | |
| 4007 ** the memory is allocated anyway and the current operation proceeds. | |
| 4008 ** | |
| 4009 ** A negative or zero value for N means that there is no soft heap limit and | |
| 4010 ** [sqlite3_release_memory()] will only be called when memory is exhausted. | |
| 4011 ** The default value for the soft heap limit is zero. | |
| 4012 ** | |
| 4013 ** SQLite makes a best effort to honor the soft heap limit. | |
| 4014 ** But if the soft heap limit cannot be honored, execution will | |
| 4015 ** continue without error or notification. This is why the limit is | |
| 4016 ** called a "soft" limit. It is advisory only. | |
| 4017 ** | |
| 4018 ** Prior to SQLite version 3.5.0, this routine only constrained the memory | |
| 4019 ** allocated by a single thread - the same thread in which this routine | |
| 4020 ** runs. Beginning with SQLite version 3.5.0, the soft heap limit is | |
| 4021 ** applied to all threads. The value specified for the soft heap limit | |
| 4022 ** is an upper bound on the total memory allocation for all threads. In | |
| 4023 ** version 3.5.0 there is no mechanism for limiting the heap usage for | |
| 4024 ** individual threads. | |
| 4025 ** | |
| 4026 ** Requirements: | |
| 4027 ** [H16351] [H16352] [H16353] [H16354] [H16355] [H16358] | |
| 4028 */ | |
| 4029 void sqlite3_soft_heap_limit(int); | |
| 4030 | |
| 4031 /* | |
| 4032 ** CAPI3REF: Extract Metadata About A Column Of A Table {H12850} <S60300> | |
| 4033 ** | |
| 4034 ** This routine returns metadata about a specific column of a specific | |
| 4035 ** database table accessible using the [database connection] handle | |
| 4036 ** passed as the first function argument. | |
| 4037 ** | |
| 4038 ** The column is identified by the second, third and fourth parameters to | |
| 4039 ** this function. The second parameter is either the name of the database | |
| 4040 ** (i.e. "main", "temp" or an attached database) containing the specified | |
| 4041 ** table or NULL. If it is NULL, then all attached databases are searched | |
| 4042 ** for the table using the same algorithm used by the database engine to | |
| 4043 ** resolve unqualified table references. | |
| 4044 ** | |
| 4045 ** The third and fourth parameters to this function are the table and column | |
| 4046 ** name of the desired column, respectively. Neither of these parameters | |
| 4047 ** may be NULL. | |
| 4048 ** | |
| 4049 ** Metadata is returned by writing to the memory locations passed as the 5th | |
| 4050 ** and subsequent parameters to this function. Any of these arguments may be | |
| 4051 ** NULL, in which case the corresponding element of metadata is omitted. | |
| 4052 ** | |
| 4053 ** <blockquote> | |
| 4054 ** <table border="1"> | |
| 4055 ** <tr><th> Parameter <th> Output<br>Type <th> Description | |
| 4056 ** | |
| 4057 ** <tr><td> 5th <td> const char* <td> Data type | |
| 4058 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence | |
| 4059 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint | |
| 4060 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY | |
| 4061 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] | |
| 4062 ** </table> | |
| 4063 ** </blockquote> | |
| 4064 ** | |
| 4065 ** The memory pointed to by the character pointers returned for the | |
| 4066 ** declaration type and collation sequence is valid only until the next | |
| 4067 ** call to any SQLite API function. | |
| 4068 ** | |
| 4069 ** If the specified table is actually a view, an [error code] is returned. | |
| 4070 ** | |
| 4071 ** If the specified column is "rowid", "oid" or "_rowid_" and an | |
| 4072 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output | |
| 4073 ** parameters are set for the explicitly declared column. If there is no | |
| 4074 ** explicitly declared [INTEGER PRIMARY KEY] column, then the output | |
| 4075 ** parameters are set as follows: | |
| 4076 ** | |
| 4077 ** <pre> | |
| 4078 ** data type: "INTEGER" | |
| 4079 ** collation sequence: "BINARY" | |
| 4080 ** not null: 0 | |
| 4081 ** primary key: 1 | |
| 4082 ** auto increment: 0 | |
| 4083 ** </pre> | |
| 4084 ** | |
| 4085 ** This function may load one or more schemas from database files. If an | |
| 4086 ** error occurs during this process, or if the requested table or column | |
| 4087 ** cannot be found, an [error code] is returned and an error message left | |
| 4088 ** in the [database connection] (to be retrieved using sqlite3_errmsg()). | |
| 4089 ** | |
| 4090 ** This API is only available if the library was compiled with the | |
| 4091 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. | |
| 4092 */ | |
| 4093 int sqlite3_table_column_metadata( | |
| 4094 sqlite3 *db, /* Connection handle */ | |
| 4095 const char *zDbName, /* Database name or NULL */ | |
| 4096 const char *zTableName, /* Table name */ | |
| 4097 const char *zColumnName, /* Column name */ | |
| 4098 char const **pzDataType, /* OUTPUT: Declared data type */ | |
| 4099 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ | |
| 4100 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ | |
| 4101 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ | |
| 4102 int *pAutoinc /* OUTPUT: True if column is auto-increment */ | |
| 4103 ); | |
| 4104 | |
| 4105 /* | |
| 4106 ** CAPI3REF: Load An Extension {H12600} <S20500> | |
| 4107 ** | |
| 4108 ** This interface loads an SQLite extension library from the named file. | |
| 4109 ** | |
| 4110 ** {H12601} The sqlite3_load_extension() interface attempts to load an | |
| 4111 ** SQLite extension library contained in the file zFile. | |
| 4112 ** | |
| 4113 ** {H12602} The entry point is zProc. | |
| 4114 ** | |
| 4115 ** {H12603} zProc may be 0, in which case the name of the entry point | |
| 4116 ** defaults to "sqlite3_extension_init". | |
| 4117 ** | |
| 4118 ** {H12604} The sqlite3_load_extension() interface shall return | |
| 4119 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. | |
| 4120 ** | |
| 4121 ** {H12605} If an error occurs and pzErrMsg is not 0, then the | |
| 4122 ** [sqlite3_load_extension()] interface shall attempt to | |
| 4123 ** fill *pzErrMsg with error message text stored in memory | |
| 4124 ** obtained from [sqlite3_malloc()]. {END} The calling function | |
| 4125 ** should free this memory by calling [sqlite3_free()]. | |
| 4126 ** | |
| 4127 ** {H12606} Extension loading must be enabled using | |
| 4128 ** [sqlite3_enable_load_extension()] prior to calling this API, | |
| 4129 ** otherwise an error will be returned. | |
| 4130 */ | |
| 4131 int sqlite3_load_extension( | |
| 4132 sqlite3 *db, /* Load the extension into this database connection */ | |
| 4133 const char *zFile, /* Name of the shared library containing extension */ | |
| 4134 const char *zProc, /* Entry point. Derived from zFile if 0 */ | |
| 4135 char **pzErrMsg /* Put error message here if not 0 */ | |
| 4136 ); | |
| 4137 | |
| 4138 /* | |
| 4139 ** CAPI3REF: Enable Or Disable Extension Loading {H12620} <S20500> | |
| 4140 ** | |
| 4141 ** So as not to open security holes in older applications that are | |
| 4142 ** unprepared to deal with extension loading, and as a means of disabling | |
| 4143 ** extension loading while evaluating user-entered SQL, the following API | |
| 4144 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. | |
| 4145 ** | |
| 4146 ** Extension loading is off by default. See ticket #1863. | |
| 4147 ** | |
| 4148 ** {H12621} Call the sqlite3_enable_load_extension() routine with onoff==1 | |
| 4149 ** to turn extension loading on and call it with onoff==0 to turn | |
| 4150 ** it back off again. | |
| 4151 ** | |
| 4152 ** {H12622} Extension loading is off by default. | |
| 4153 */ | |
| 4154 int sqlite3_enable_load_extension(sqlite3 *db, int onoff); | |
| 4155 | |
| 4156 /* | |
| 4157 ** CAPI3REF: Automatically Load An Extensions {H12640} <S20500> | |
| 4158 ** | |
| 4159 ** This API can be invoked at program startup in order to register | |
| 4160 ** one or more statically linked extensions that will be available | |
| 4161 ** to all new [database connections]. {END} | |
| 4162 ** | |
| 4163 ** This routine stores a pointer to the extension in an array that is | |
| 4164 ** obtained from [sqlite3_malloc()]. If you run a memory leak checker | |
| 4165 ** on your program and it reports a leak because of this array, invoke | |
| 4166 ** [sqlite3_reset_auto_extension()] prior to shutdown to free the memory. | |
| 4167 ** | |
| 4168 ** {H12641} This function registers an extension entry point that is | |
| 4169 ** automatically invoked whenever a new [database connection] | |
| 4170 ** is opened using [sqlite3_open()], [sqlite3_open16()], | |
| 4171 ** or [sqlite3_open_v2()]. | |
| 4172 ** | |
| 4173 ** {H12642} Duplicate extensions are detected so calling this routine | |
| 4174 ** multiple times with the same extension is harmless. | |
| 4175 ** | |
| 4176 ** {H12643} This routine stores a pointer to the extension in an array | |
| 4177 ** that is obtained from [sqlite3_malloc()]. | |
| 4178 ** | |
| 4179 ** {H12644} Automatic extensions apply across all threads. | |
| 4180 */ | |
| 4181 int sqlite3_auto_extension(void (*xEntryPoint)(void)); | |
| 4182 | |
| 4183 /* | |
| 4184 ** CAPI3REF: Reset Automatic Extension Loading {H12660} <S20500> | |
| 4185 ** | |
| 4186 ** This function disables all previously registered automatic | |
| 4187 ** extensions. {END} It undoes the effect of all prior | |
| 4188 ** [sqlite3_auto_extension()] calls. | |
| 4189 ** | |
| 4190 ** {H12661} This function disables all previously registered | |
| 4191 ** automatic extensions. | |
| 4192 ** | |
| 4193 ** {H12662} This function disables automatic extensions in all threads. | |
| 4194 */ | |
| 4195 void sqlite3_reset_auto_extension(void); | |
| 4196 | |
| 4197 /* | |
| 4198 ****** EXPERIMENTAL - subject to change without notice ************** | |
| 4199 ** | |
| 4200 ** The interface to the virtual-table mechanism is currently considered | |
| 4201 ** to be experimental. The interface might change in incompatible ways. | |
| 4202 ** If this is a problem for you, do not use the interface at this time. | |
| 4203 ** | |
| 4204 ** When the virtual-table mechanism stabilizes, we will declare the | |
| 4205 ** interface fixed, support it indefinitely, and remove this comment. | |
| 4206 */ | |
| 4207 | |
| 4208 /* | |
| 4209 ** Structures used by the virtual table interface | |
| 4210 */ | |
| 4211 typedef struct sqlite3_vtab sqlite3_vtab; | |
| 4212 typedef struct sqlite3_index_info sqlite3_index_info; | |
| 4213 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; | |
| 4214 typedef struct sqlite3_module sqlite3_module; | |
| 4215 | |
| 4216 /* | |
| 4217 ** CAPI3REF: Virtual Table Object {H18000} <S20400> | |
| 4218 ** KEYWORDS: sqlite3_module {virtual table module} | |
| 4219 ** EXPERIMENTAL | |
| 4220 ** | |
| 4221 ** This structure, sometimes called a a "virtual table module", | |
| 4222 ** defines the implementation of a [virtual tables]. | |
| 4223 ** This structure consists mostly of methods for the module. | |
| 4224 ** | |
| 4225 ** A virtual table module is created by filling in a persistent | |
| 4226 ** instance of this structure and passing a pointer to that instance | |
| 4227 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. | |
| 4228 ** The registration remains valid until it is replaced by a different | |
| 4229 ** module or until the [database connection] closes. The content | |
| 4230 ** of this structure must not change while it is registered with | |
| 4231 ** any database connection. | |
| 4232 */ | |
| 4233 struct sqlite3_module { | |
| 4234 int iVersion; | |
| 4235 int (*xCreate)(sqlite3*, void *pAux, | |
| 4236 int argc, const char *const*argv, | |
| 4237 sqlite3_vtab **ppVTab, char**); | |
| 4238 int (*xConnect)(sqlite3*, void *pAux, | |
| 4239 int argc, const char *const*argv, | |
| 4240 sqlite3_vtab **ppVTab, char**); | |
| 4241 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); | |
| 4242 int (*xDisconnect)(sqlite3_vtab *pVTab); | |
| 4243 int (*xDestroy)(sqlite3_vtab *pVTab); | |
| 4244 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); | |
| 4245 int (*xClose)(sqlite3_vtab_cursor*); | |
| 4246 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, | |
| 4247 int argc, sqlite3_value **argv); | |
| 4248 int (*xNext)(sqlite3_vtab_cursor*); | |
| 4249 int (*xEof)(sqlite3_vtab_cursor*); | |
| 4250 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); | |
| 4251 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); | |
| 4252 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); | |
| 4253 int (*xBegin)(sqlite3_vtab *pVTab); | |
| 4254 int (*xSync)(sqlite3_vtab *pVTab); | |
| 4255 int (*xCommit)(sqlite3_vtab *pVTab); | |
| 4256 int (*xRollback)(sqlite3_vtab *pVTab); | |
| 4257 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, | |
| 4258 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), | |
| 4259 void **ppArg); | |
| 4260 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); | |
| 4261 }; | |
| 4262 | |
| 4263 /* | |
| 4264 ** CAPI3REF: Virtual Table Indexing Information {H18100} <S20400> | |
| 4265 ** KEYWORDS: sqlite3_index_info | |
| 4266 ** EXPERIMENTAL | |
| 4267 ** | |
| 4268 ** The sqlite3_index_info structure and its substructures is used to | |
| 4269 ** pass information into and receive the reply from the [xBestIndex] | |
| 4270 ** method of a [virtual table module]. The fields under **Inputs** are the | |
| 4271 ** inputs to xBestIndex and are read-only. xBestIndex inserts its | |
| 4272 ** results into the **Outputs** fields. | |
| 4273 ** | |
| 4274 ** The aConstraint[] array records WHERE clause constraints of the form: | |
| 4275 ** | |
| 4276 ** <pre>column OP expr</pre> | |
| 4277 ** | |
| 4278 ** where OP is =, <, <=, >, or >=. The particular operator is | |
| 4279 ** stored in aConstraint[].op. The index of the column is stored in | |
| 4280 ** aConstraint[].iColumn. aConstraint[].usable is TRUE if the | |
| 4281 ** expr on the right-hand side can be evaluated (and thus the constraint | |
| 4282 ** is usable) and false if it cannot. | |
| 4283 ** | |
| 4284 ** The optimizer automatically inverts terms of the form "expr OP column" | |
| 4285 ** and makes other simplifications to the WHERE clause in an attempt to | |
| 4286 ** get as many WHERE clause terms into the form shown above as possible. | |
| 4287 ** The aConstraint[] array only reports WHERE clause terms in the correct | |
| 4288 ** form that refer to the particular virtual table being queried. | |
| 4289 ** | |
| 4290 ** Information about the ORDER BY clause is stored in aOrderBy[]. | |
| 4291 ** Each term of aOrderBy records a column of the ORDER BY clause. | |
| 4292 ** | |
| 4293 ** The [xBestIndex] method must fill aConstraintUsage[] with information | |
| 4294 ** about what parameters to pass to xFilter. If argvIndex>0 then | |
| 4295 ** the right-hand side of the corresponding aConstraint[] is evaluated | |
| 4296 ** and becomes the argvIndex-th entry in argv. If aConstraintUsage[].omit | |
| 4297 ** is true, then the constraint is assumed to be fully handled by the | |
| 4298 ** virtual table and is not checked again by SQLite. | |
| 4299 ** | |
| 4300 ** The idxNum and idxPtr values are recorded and passed into the | |
| 4301 ** [xFilter] method. | |
| 4302 ** [sqlite3_free()] is used to free idxPtr if and only iff | |
| 4303 ** needToFreeIdxPtr is true. | |
| 4304 ** | |
| 4305 ** The orderByConsumed means that output from [xFilter]/[xNext] will occur in | |
| 4306 ** the correct order to satisfy the ORDER BY clause so that no separate | |
| 4307 ** sorting step is required. | |
| 4308 ** | |
| 4309 ** The estimatedCost value is an estimate of the cost of doing the | |
| 4310 ** particular lookup. A full scan of a table with N entries should have | |
| 4311 ** a cost of N. A binary search of a table of N entries should have a | |
| 4312 ** cost of approximately log(N). | |
| 4313 */ | |
| 4314 struct sqlite3_index_info { | |
| 4315 /* Inputs */ | |
| 4316 int nConstraint; /* Number of entries in aConstraint */ | |
| 4317 struct sqlite3_index_constraint { | |
| 4318 int iColumn; /* Column on left-hand side of constraint */ | |
| 4319 unsigned char op; /* Constraint operator */ | |
| 4320 unsigned char usable; /* True if this constraint is usable */ | |
| 4321 int iTermOffset; /* Used internally - xBestIndex should ignore */ | |
| 4322 } *aConstraint; /* Table of WHERE clause constraints */ | |
| 4323 int nOrderBy; /* Number of terms in the ORDER BY clause */ | |
| 4324 struct sqlite3_index_orderby { | |
| 4325 int iColumn; /* Column number */ | |
| 4326 unsigned char desc; /* True for DESC. False for ASC. */ | |
| 4327 } *aOrderBy; /* The ORDER BY clause */ | |
| 4328 /* Outputs */ | |
| 4329 struct sqlite3_index_constraint_usage { | |
| 4330 int argvIndex; /* if >0, constraint is part of argv to xFilter */ | |
| 4331 unsigned char omit; /* Do not code a test for this constraint */ | |
| 4332 } *aConstraintUsage; | |
| 4333 int idxNum; /* Number used to identify the index */ | |
| 4334 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ | |
| 4335 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ | |
| 4336 int orderByConsumed; /* True if output is already ordered */ | |
| 4337 double estimatedCost; /* Estimated cost of using this index */ | |
| 4338 }; | |
| 4339 #define SQLITE_INDEX_CONSTRAINT_EQ 2 | |
| 4340 #define SQLITE_INDEX_CONSTRAINT_GT 4 | |
| 4341 #define SQLITE_INDEX_CONSTRAINT_LE 8 | |
| 4342 #define SQLITE_INDEX_CONSTRAINT_LT 16 | |
| 4343 #define SQLITE_INDEX_CONSTRAINT_GE 32 | |
| 4344 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 | |
| 4345 | |
| 4346 /* | |
| 4347 ** CAPI3REF: Register A Virtual Table Implementation {H18200} <S20400> | |
| 4348 ** EXPERIMENTAL | |
| 4349 ** | |
| 4350 ** This routine is used to register a new [virtual table module] name. | |
| 4351 ** Module names must be registered before | |
| 4352 ** creating a new [virtual table] using the module, or before using a | |
| 4353 ** preexisting [virtual table] for the module. | |
| 4354 ** | |
| 4355 ** The module name is registered on the [database connection] specified | |
| 4356 ** by the first parameter. The name of the module is given by the | |
| 4357 ** second parameter. The third parameter is a pointer to | |
| 4358 ** the implementation of the [virtual table module]. The fourth | |
| 4359 ** parameter is an arbitrary client data pointer that is passed through | |
| 4360 ** into the [xCreate] and [xConnect] methods of the virtual table module | |
| 4361 ** when a new virtual table is be being created or reinitialized. | |
| 4362 ** | |
| 4363 ** This interface has exactly the same effect as calling | |
| 4364 ** [sqlite3_create_module_v2()] with a NULL client data destructor. | |
| 4365 */ | |
| 4366 SQLITE_EXPERIMENTAL int sqlite3_create_module( | |
| 4367 sqlite3 *db, /* SQLite connection to register module with */ | |
| 4368 const char *zName, /* Name of the module */ | |
| 4369 const sqlite3_module *p, /* Methods for the module */ | |
| 4370 void *pClientData /* Client data for xCreate/xConnect */ | |
| 4371 ); | |
| 4372 | |
| 4373 /* | |
| 4374 ** CAPI3REF: Register A Virtual Table Implementation {H18210} <S20400> | |
| 4375 ** EXPERIMENTAL | |
| 4376 ** | |
| 4377 ** This routine is identical to the [sqlite3_create_module()] method, | |
| 4378 ** except that it has an extra parameter to specify | |
| 4379 ** a destructor function for the client data pointer. SQLite will | |
| 4380 ** invoke the destructor function (if it is not NULL) when SQLite | |
| 4381 ** no longer needs the pClientData pointer. | |
| 4382 */ | |
| 4383 SQLITE_EXPERIMENTAL int sqlite3_create_module_v2( | |
| 4384 sqlite3 *db, /* SQLite connection to register module with */ | |
| 4385 const char *zName, /* Name of the module */ | |
| 4386 const sqlite3_module *p, /* Methods for the module */ | |
| 4387 void *pClientData, /* Client data for xCreate/xConnect */ | |
| 4388 void(*xDestroy)(void*) /* Module destructor function */ | |
| 4389 ); | |
| 4390 | |
| 4391 /* | |
| 4392 ** CAPI3REF: Virtual Table Instance Object {H18010} <S20400> | |
| 4393 ** KEYWORDS: sqlite3_vtab | |
| 4394 ** EXPERIMENTAL | |
| 4395 ** | |
| 4396 ** Every [virtual table module] implementation uses a subclass | |
| 4397 ** of the following structure to describe a particular instance | |
| 4398 ** of the [virtual table]. Each subclass will | |
| 4399 ** be tailored to the specific needs of the module implementation. | |
| 4400 ** The purpose of this superclass is to define certain fields that are | |
| 4401 ** common to all module implementations. | |
| 4402 ** | |
| 4403 ** Virtual tables methods can set an error message by assigning a | |
| 4404 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should | |
| 4405 ** take care that any prior string is freed by a call to [sqlite3_free()] | |
| 4406 ** prior to assigning a new string to zErrMsg. After the error message | |
| 4407 ** is delivered up to the client application, the string will be automatically | |
| 4408 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. | |
| 4409 */ | |
| 4410 struct sqlite3_vtab { | |
| 4411 const sqlite3_module *pModule; /* The module for this virtual table */ | |
| 4412 int nRef; /* NO LONGER USED */ | |
| 4413 char *zErrMsg; /* Error message from sqlite3_mprintf() */ | |
| 4414 /* Virtual table implementations will typically add additional fields */ | |
| 4415 }; | |
| 4416 | |
| 4417 /* | |
| 4418 ** CAPI3REF: Virtual Table Cursor Object {H18020} <S20400> | |
| 4419 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} | |
| 4420 ** EXPERIMENTAL | |
| 4421 ** | |
| 4422 ** Every [virtual table module] implementation uses a subclass of the | |
| 4423 ** following structure to describe cursors that point into the | |
| 4424 ** [virtual table] and are used | |
| 4425 ** to loop through the virtual table. Cursors are created using the | |
| 4426 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed | |
| 4427 ** by the [sqlite3_module.xClose | xClose] method. Cussors are used | |
| 4428 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods | |
| 4429 ** of the module. Each module implementation will define | |
| 4430 ** the content of a cursor structure to suit its own needs. | |
| 4431 ** | |
| 4432 ** This superclass exists in order to define fields of the cursor that | |
| 4433 ** are common to all implementations. | |
| 4434 */ | |
| 4435 struct sqlite3_vtab_cursor { | |
| 4436 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ | |
| 4437 /* Virtual table implementations will typically add additional fields */ | |
| 4438 }; | |
| 4439 | |
| 4440 /* | |
| 4441 ** CAPI3REF: Declare The Schema Of A Virtual Table {H18280} <S20400> | |
| 4442 ** EXPERIMENTAL | |
| 4443 ** | |
| 4444 ** The [xCreate] and [xConnect] methods of a | |
| 4445 ** [virtual table module] call this interface | |
| 4446 ** to declare the format (the names and datatypes of the columns) of | |
| 4447 ** the virtual tables they implement. | |
| 4448 */ | |
| 4449 SQLITE_EXPERIMENTAL int sqlite3_declare_vtab(sqlite3*, const char *zSQL); | |
| 4450 | |
| 4451 /* | |
| 4452 ** CAPI3REF: Overload A Function For A Virtual Table {H18300} <S20400> | |
| 4453 ** EXPERIMENTAL | |
| 4454 ** | |
| 4455 ** Virtual tables can provide alternative implementations of functions | |
| 4456 ** using the [xFindFunction] method of the [virtual table module]. | |
| 4457 ** But global versions of those functions | |
| 4458 ** must exist in order to be overloaded. | |
| 4459 ** | |
| 4460 ** This API makes sure a global version of a function with a particular | |
| 4461 ** name and number of parameters exists. If no such function exists | |
| 4462 ** before this API is called, a new function is created. The implementation | |
| 4463 ** of the new function always causes an exception to be thrown. So | |
| 4464 ** the new function is not good for anything by itself. Its only | |
| 4465 ** purpose is to be a placeholder function that can be overloaded | |
| 4466 ** by a [virtual table]. | |
| 4467 */ | |
| 4468 SQLITE_EXPERIMENTAL int sqlite3_overload_function(sqlite3*, const char *zFuncNam
e, int nArg); | |
| 4469 | |
| 4470 /* | |
| 4471 ** The interface to the virtual-table mechanism defined above (back up | |
| 4472 ** to a comment remarkably similar to this one) is currently considered | |
| 4473 ** to be experimental. The interface might change in incompatible ways. | |
| 4474 ** If this is a problem for you, do not use the interface at this time. | |
| 4475 ** | |
| 4476 ** When the virtual-table mechanism stabilizes, we will declare the | |
| 4477 ** interface fixed, support it indefinitely, and remove this comment. | |
| 4478 ** | |
| 4479 ****** EXPERIMENTAL - subject to change without notice ************** | |
| 4480 */ | |
| 4481 | |
| 4482 /* | |
| 4483 ** CAPI3REF: A Handle To An Open BLOB {H17800} <S30230> | |
| 4484 ** KEYWORDS: {BLOB handle} {BLOB handles} | |
| 4485 ** | |
| 4486 ** An instance of this object represents an open BLOB on which | |
| 4487 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. | |
| 4488 ** Objects of this type are created by [sqlite3_blob_open()] | |
| 4489 ** and destroyed by [sqlite3_blob_close()]. | |
| 4490 ** The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces | |
| 4491 ** can be used to read or write small subsections of the BLOB. | |
| 4492 ** The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. | |
| 4493 */ | |
| 4494 typedef struct sqlite3_blob sqlite3_blob; | |
| 4495 | |
| 4496 /* | |
| 4497 ** CAPI3REF: Open A BLOB For Incremental I/O {H17810} <S30230> | |
| 4498 ** | |
| 4499 ** This interfaces opens a [BLOB handle | handle] to the BLOB located | |
| 4500 ** in row iRow, column zColumn, table zTable in database zDb; | |
| 4501 ** in other words, the same BLOB that would be selected by: | |
| 4502 ** | |
| 4503 ** <pre> | |
| 4504 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; | |
| 4505 ** </pre> {END} | |
| 4506 ** | |
| 4507 ** If the flags parameter is non-zero, then the BLOB is opened for read | |
| 4508 ** and write access. If it is zero, the BLOB is opened for read access. | |
| 4509 ** | |
| 4510 ** Note that the database name is not the filename that contains | |
| 4511 ** the database but rather the symbolic name of the database that | |
| 4512 ** is assigned when the database is connected using [ATTACH]. | |
| 4513 ** For the main database file, the database name is "main". | |
| 4514 ** For TEMP tables, the database name is "temp". | |
| 4515 ** | |
| 4516 ** On success, [SQLITE_OK] is returned and the new [BLOB handle] is written | |
| 4517 ** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set | |
| 4518 ** to be a null pointer. | |
| 4519 ** This function sets the [database connection] error code and message | |
| 4520 ** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related | |
| 4521 ** functions. Note that the *ppBlob variable is always initialized in a | |
| 4522 ** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob | |
| 4523 ** regardless of the success or failure of this routine. | |
| 4524 ** | |
| 4525 ** If the row that a BLOB handle points to is modified by an | |
| 4526 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects | |
| 4527 ** then the BLOB handle is marked as "expired". | |
| 4528 ** This is true if any column of the row is changed, even a column | |
| 4529 ** other than the one the BLOB handle is open on. | |
| 4530 ** Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for | |
| 4531 ** a expired BLOB handle fail with an return code of [SQLITE_ABORT]. | |
| 4532 ** Changes written into a BLOB prior to the BLOB expiring are not | |
| 4533 ** rollback by the expiration of the BLOB. Such changes will eventually | |
| 4534 ** commit if the transaction continues to completion. | |
| 4535 ** | |
| 4536 ** Use the [sqlite3_blob_bytes()] interface to determine the size of | |
| 4537 ** the opened blob. The size of a blob may not be changed by this | |
| 4538 ** interface. Use the [UPDATE] SQL command to change the size of a | |
| 4539 ** blob. | |
| 4540 ** | |
| 4541 ** The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces | |
| 4542 ** and the built-in [zeroblob] SQL function can be used, if desired, | |
| 4543 ** to create an empty, zero-filled blob in which to read or write using | |
| 4544 ** this interface. | |
| 4545 ** | |
| 4546 ** To avoid a resource leak, every open [BLOB handle] should eventually | |
| 4547 ** be released by a call to [sqlite3_blob_close()]. | |
| 4548 ** | |
| 4549 ** Requirements: | |
| 4550 ** [H17813] [H17814] [H17816] [H17819] [H17821] [H17824] | |
| 4551 */ | |
| 4552 int sqlite3_blob_open( | |
| 4553 sqlite3*, | |
| 4554 const char *zDb, | |
| 4555 const char *zTable, | |
| 4556 const char *zColumn, | |
| 4557 sqlite3_int64 iRow, | |
| 4558 int flags, | |
| 4559 sqlite3_blob **ppBlob | |
| 4560 ); | |
| 4561 | |
| 4562 /* | |
| 4563 ** CAPI3REF: Close A BLOB Handle {H17830} <S30230> | |
| 4564 ** | |
| 4565 ** Closes an open [BLOB handle]. | |
| 4566 ** | |
| 4567 ** Closing a BLOB shall cause the current transaction to commit | |
| 4568 ** if there are no other BLOBs, no pending prepared statements, and the | |
| 4569 ** database connection is in [autocommit mode]. | |
| 4570 ** If any writes were made to the BLOB, they might be held in cache | |
| 4571 ** until the close operation if they will fit. | |
| 4572 ** | |
| 4573 ** Closing the BLOB often forces the changes | |
| 4574 ** out to disk and so if any I/O errors occur, they will likely occur | |
| 4575 ** at the time when the BLOB is closed. Any errors that occur during | |
| 4576 ** closing are reported as a non-zero return value. | |
| 4577 ** | |
| 4578 ** The BLOB is closed unconditionally. Even if this routine returns | |
| 4579 ** an error code, the BLOB is still closed. | |
| 4580 ** | |
| 4581 ** Calling this routine with a null pointer (which as would be returned | |
| 4582 ** by failed call to [sqlite3_blob_open()]) is a harmless no-op. | |
| 4583 ** | |
| 4584 ** Requirements: | |
| 4585 ** [H17833] [H17836] [H17839] | |
| 4586 */ | |
| 4587 int sqlite3_blob_close(sqlite3_blob *); | |
| 4588 | |
| 4589 /* | |
| 4590 ** CAPI3REF: Return The Size Of An Open BLOB {H17840} <S30230> | |
| 4591 ** | |
| 4592 ** Returns the size in bytes of the BLOB accessible via the | |
| 4593 ** successfully opened [BLOB handle] in its only argument. The | |
| 4594 ** incremental blob I/O routines can only read or overwriting existing | |
| 4595 ** blob content; they cannot change the size of a blob. | |
| 4596 ** | |
| 4597 ** This routine only works on a [BLOB handle] which has been created | |
| 4598 ** by a prior successful call to [sqlite3_blob_open()] and which has not | |
| 4599 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in | |
| 4600 ** to this routine results in undefined and probably undesirable behavior. | |
| 4601 ** | |
| 4602 ** Requirements: | |
| 4603 ** [H17843] | |
| 4604 */ | |
| 4605 int sqlite3_blob_bytes(sqlite3_blob *); | |
| 4606 | |
| 4607 /* | |
| 4608 ** CAPI3REF: Read Data From A BLOB Incrementally {H17850} <S30230> | |
| 4609 ** | |
| 4610 ** This function is used to read data from an open [BLOB handle] into a | |
| 4611 ** caller-supplied buffer. N bytes of data are copied into buffer Z | |
| 4612 ** from the open BLOB, starting at offset iOffset. | |
| 4613 ** | |
| 4614 ** If offset iOffset is less than N bytes from the end of the BLOB, | |
| 4615 ** [SQLITE_ERROR] is returned and no data is read. If N or iOffset is | |
| 4616 ** less than zero, [SQLITE_ERROR] is returned and no data is read. | |
| 4617 ** The size of the blob (and hence the maximum value of N+iOffset) | |
| 4618 ** can be determined using the [sqlite3_blob_bytes()] interface. | |
| 4619 ** | |
| 4620 ** An attempt to read from an expired [BLOB handle] fails with an | |
| 4621 ** error code of [SQLITE_ABORT]. | |
| 4622 ** | |
| 4623 ** On success, SQLITE_OK is returned. | |
| 4624 ** Otherwise, an [error code] or an [extended error code] is returned. | |
| 4625 ** | |
| 4626 ** This routine only works on a [BLOB handle] which has been created | |
| 4627 ** by a prior successful call to [sqlite3_blob_open()] and which has not | |
| 4628 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in | |
| 4629 ** to this routine results in undefined and probably undesirable behavior. | |
| 4630 ** | |
| 4631 ** See also: [sqlite3_blob_write()]. | |
| 4632 ** | |
| 4633 ** Requirements: | |
| 4634 ** [H17853] [H17856] [H17859] [H17862] [H17863] [H17865] [H17868] | |
| 4635 */ | |
| 4636 int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); | |
| 4637 | |
| 4638 /* | |
| 4639 ** CAPI3REF: Write Data Into A BLOB Incrementally {H17870} <S30230> | |
| 4640 ** | |
| 4641 ** This function is used to write data into an open [BLOB handle] from a | |
| 4642 ** caller-supplied buffer. N bytes of data are copied from the buffer Z | |
| 4643 ** into the open BLOB, starting at offset iOffset. | |
| 4644 ** | |
| 4645 ** If the [BLOB handle] passed as the first argument was not opened for | |
| 4646 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), | |
| 4647 ** this function returns [SQLITE_READONLY]. | |
| 4648 ** | |
| 4649 ** This function may only modify the contents of the BLOB; it is | |
| 4650 ** not possible to increase the size of a BLOB using this API. | |
| 4651 ** If offset iOffset is less than N bytes from the end of the BLOB, | |
| 4652 ** [SQLITE_ERROR] is returned and no data is written. If N is | |
| 4653 ** less than zero [SQLITE_ERROR] is returned and no data is written. | |
| 4654 ** The size of the BLOB (and hence the maximum value of N+iOffset) | |
| 4655 ** can be determined using the [sqlite3_blob_bytes()] interface. | |
| 4656 ** | |
| 4657 ** An attempt to write to an expired [BLOB handle] fails with an | |
| 4658 ** error code of [SQLITE_ABORT]. Writes to the BLOB that occurred | |
| 4659 ** before the [BLOB handle] expired are not rolled back by the | |
| 4660 ** expiration of the handle, though of course those changes might | |
| 4661 ** have been overwritten by the statement that expired the BLOB handle | |
| 4662 ** or by other independent statements. | |
| 4663 ** | |
| 4664 ** On success, SQLITE_OK is returned. | |
| 4665 ** Otherwise, an [error code] or an [extended error code] is returned. | |
| 4666 ** | |
| 4667 ** This routine only works on a [BLOB handle] which has been created | |
| 4668 ** by a prior successful call to [sqlite3_blob_open()] and which has not | |
| 4669 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in | |
| 4670 ** to this routine results in undefined and probably undesirable behavior. | |
| 4671 ** | |
| 4672 ** See also: [sqlite3_blob_read()]. | |
| 4673 ** | |
| 4674 ** Requirements: | |
| 4675 ** [H17873] [H17874] [H17875] [H17876] [H17877] [H17879] [H17882] [H17885] | |
| 4676 ** [H17888] | |
| 4677 */ | |
| 4678 int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); | |
| 4679 | |
| 4680 /* Begin preload-cache.patch for Chromium */ | |
| 4681 /* | |
| 4682 ** Preload the databases into the pager cache, up to the maximum size of the | |
| 4683 ** pager cache. | |
| 4684 ** | |
| 4685 ** For a database to be loaded successfully, the pager must be active. That is, | |
| 4686 ** there must be an open statement on that database. See sqlite3pager_loadall | |
| 4687 ** | |
| 4688 ** There might be many databases attached to the given connection. We iterate | |
| 4689 ** them all and try to load them. If none are loadable successfully, we return | |
| 4690 ** an error. Otherwise, we return OK. | |
| 4691 */ | |
| 4692 int sqlite3Preload(sqlite3 *db); | |
| 4693 /* End preload-cache.patch for Chromium */ | |
| 4694 | |
| 4695 /* | |
| 4696 ** CAPI3REF: Virtual File System Objects {H11200} <S20100> | |
| 4697 ** | |
| 4698 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object | |
| 4699 ** that SQLite uses to interact | |
| 4700 ** with the underlying operating system. Most SQLite builds come with a | |
| 4701 ** single default VFS that is appropriate for the host computer. | |
| 4702 ** New VFSes can be registered and existing VFSes can be unregistered. | |
| 4703 ** The following interfaces are provided. | |
| 4704 ** | |
| 4705 ** The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. | |
| 4706 ** Names are case sensitive. | |
| 4707 ** Names are zero-terminated UTF-8 strings. | |
| 4708 ** If there is no match, a NULL pointer is returned. | |
| 4709 ** If zVfsName is NULL then the default VFS is returned. | |
| 4710 ** | |
| 4711 ** New VFSes are registered with sqlite3_vfs_register(). | |
| 4712 ** Each new VFS becomes the default VFS if the makeDflt flag is set. | |
| 4713 ** The same VFS can be registered multiple times without injury. | |
| 4714 ** To make an existing VFS into the default VFS, register it again | |
| 4715 ** with the makeDflt flag set. If two different VFSes with the | |
| 4716 ** same name are registered, the behavior is undefined. If a | |
| 4717 ** VFS is registered with a name that is NULL or an empty string, | |
| 4718 ** then the behavior is undefined. | |
| 4719 ** | |
| 4720 ** Unregister a VFS with the sqlite3_vfs_unregister() interface. | |
| 4721 ** If the default VFS is unregistered, another VFS is chosen as | |
| 4722 ** the default. The choice for the new VFS is arbitrary. | |
| 4723 ** | |
| 4724 ** Requirements: | |
| 4725 ** [H11203] [H11206] [H11209] [H11212] [H11215] [H11218] | |
| 4726 */ | |
| 4727 sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); | |
| 4728 int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); | |
| 4729 int sqlite3_vfs_unregister(sqlite3_vfs*); | |
| 4730 | |
| 4731 /* | |
| 4732 ** CAPI3REF: Mutexes {H17000} <S20000> | |
| 4733 ** | |
| 4734 ** The SQLite core uses these routines for thread | |
| 4735 ** synchronization. Though they are intended for internal | |
| 4736 ** use by SQLite, code that links against SQLite is | |
| 4737 ** permitted to use any of these routines. | |
| 4738 ** | |
| 4739 ** The SQLite source code contains multiple implementations | |
| 4740 ** of these mutex routines. An appropriate implementation | |
| 4741 ** is selected automatically at compile-time. The following | |
| 4742 ** implementations are available in the SQLite core: | |
| 4743 ** | |
| 4744 ** <ul> | |
| 4745 ** <li> SQLITE_MUTEX_OS2 | |
| 4746 ** <li> SQLITE_MUTEX_PTHREAD | |
| 4747 ** <li> SQLITE_MUTEX_W32 | |
| 4748 ** <li> SQLITE_MUTEX_NOOP | |
| 4749 ** </ul> | |
| 4750 ** | |
| 4751 ** The SQLITE_MUTEX_NOOP implementation is a set of routines | |
| 4752 ** that does no real locking and is appropriate for use in | |
| 4753 ** a single-threaded application. The SQLITE_MUTEX_OS2, | |
| 4754 ** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations | |
| 4755 ** are appropriate for use on OS/2, Unix, and Windows. | |
| 4756 ** | |
| 4757 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor | |
| 4758 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex | |
| 4759 ** implementation is included with the library. In this case the | |
| 4760 ** application must supply a custom mutex implementation using the | |
| 4761 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function | |
| 4762 ** before calling sqlite3_initialize() or any other public sqlite3_ | |
| 4763 ** function that calls sqlite3_initialize(). | |
| 4764 ** | |
| 4765 ** {H17011} The sqlite3_mutex_alloc() routine allocates a new | |
| 4766 ** mutex and returns a pointer to it. {H17012} If it returns NULL | |
| 4767 ** that means that a mutex could not be allocated. {H17013} SQLite | |
| 4768 ** will unwind its stack and return an error. {H17014} The argument | |
| 4769 ** to sqlite3_mutex_alloc() is one of these integer constants: | |
| 4770 ** | |
| 4771 ** <ul> | |
| 4772 ** <li> SQLITE_MUTEX_FAST | |
| 4773 ** <li> SQLITE_MUTEX_RECURSIVE | |
| 4774 ** <li> SQLITE_MUTEX_STATIC_MASTER | |
| 4775 ** <li> SQLITE_MUTEX_STATIC_MEM | |
| 4776 ** <li> SQLITE_MUTEX_STATIC_MEM2 | |
| 4777 ** <li> SQLITE_MUTEX_STATIC_PRNG | |
| 4778 ** <li> SQLITE_MUTEX_STATIC_LRU | |
| 4779 ** <li> SQLITE_MUTEX_STATIC_LRU2 | |
| 4780 ** </ul> | |
| 4781 ** | |
| 4782 ** {H17015} The first two constants cause sqlite3_mutex_alloc() to create | |
| 4783 ** a new mutex. The new mutex is recursive when SQLITE_MUTEX_RECURSIVE | |
| 4784 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. {END} | |
| 4785 ** The mutex implementation does not need to make a distinction | |
| 4786 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does | |
| 4787 ** not want to. {H17016} But SQLite will only request a recursive mutex in | |
| 4788 ** cases where it really needs one. {END} If a faster non-recursive mutex | |
| 4789 ** implementation is available on the host platform, the mutex subsystem | |
| 4790 ** might return such a mutex in response to SQLITE_MUTEX_FAST. | |
| 4791 ** | |
| 4792 ** {H17017} The other allowed parameters to sqlite3_mutex_alloc() each return | |
| 4793 ** a pointer to a static preexisting mutex. {END} Six static mutexes are | |
| 4794 ** used by the current version of SQLite. Future versions of SQLite | |
| 4795 ** may add additional static mutexes. Static mutexes are for internal | |
| 4796 ** use by SQLite only. Applications that use SQLite mutexes should | |
| 4797 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or | |
| 4798 ** SQLITE_MUTEX_RECURSIVE. | |
| 4799 ** | |
| 4800 ** {H17018} Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST | |
| 4801 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() | |
| 4802 ** returns a different mutex on every call. {H17034} But for the static | |
| 4803 ** mutex types, the same mutex is returned on every call that has | |
| 4804 ** the same type number. | |
| 4805 ** | |
| 4806 ** {H17019} The sqlite3_mutex_free() routine deallocates a previously | |
| 4807 ** allocated dynamic mutex. {H17020} SQLite is careful to deallocate every | |
| 4808 ** dynamic mutex that it allocates. {A17021} The dynamic mutexes must not be in | |
| 4809 ** use when they are deallocated. {A17022} Attempting to deallocate a static | |
| 4810 ** mutex results in undefined behavior. {H17023} SQLite never deallocates | |
| 4811 ** a static mutex. {END} | |
| 4812 ** | |
| 4813 ** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt | |
| 4814 ** to enter a mutex. {H17024} If another thread is already within the mutex, | |
| 4815 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return | |
| 4816 ** SQLITE_BUSY. {H17025} The sqlite3_mutex_try() interface returns [SQLITE_OK] | |
| 4817 ** upon successful entry. {H17026} Mutexes created using | |
| 4818 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. | |
| 4819 ** {H17027} In such cases the, | |
| 4820 ** mutex must be exited an equal number of times before another thread | |
| 4821 ** can enter. {A17028} If the same thread tries to enter any other | |
| 4822 ** kind of mutex more than once, the behavior is undefined. | |
| 4823 ** {H17029} SQLite will never exhibit | |
| 4824 ** such behavior in its own use of mutexes. | |
| 4825 ** | |
| 4826 ** Some systems (for example, Windows 95) do not support the operation | |
| 4827 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() | |
| 4828 ** will always return SQLITE_BUSY. {H17030} The SQLite core only ever uses | |
| 4829 ** sqlite3_mutex_try() as an optimization so this is acceptable behavior. | |
| 4830 ** | |
| 4831 ** {H17031} The sqlite3_mutex_leave() routine exits a mutex that was | |
| 4832 ** previously entered by the same thread. {A17032} The behavior | |
| 4833 ** is undefined if the mutex is not currently entered by the | |
| 4834 ** calling thread or is not currently allocated. {H17033} SQLite will | |
| 4835 ** never do either. {END} | |
| 4836 ** | |
| 4837 ** If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or | |
| 4838 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines | |
| 4839 ** behave as no-ops. | |
| 4840 ** | |
| 4841 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. | |
| 4842 */ | |
| 4843 sqlite3_mutex *sqlite3_mutex_alloc(int); | |
| 4844 void sqlite3_mutex_free(sqlite3_mutex*); | |
| 4845 void sqlite3_mutex_enter(sqlite3_mutex*); | |
| 4846 int sqlite3_mutex_try(sqlite3_mutex*); | |
| 4847 void sqlite3_mutex_leave(sqlite3_mutex*); | |
| 4848 | |
| 4849 /* | |
| 4850 ** CAPI3REF: Mutex Methods Object {H17120} <S20130> | |
| 4851 ** EXPERIMENTAL | |
| 4852 ** | |
| 4853 ** An instance of this structure defines the low-level routines | |
| 4854 ** used to allocate and use mutexes. | |
| 4855 ** | |
| 4856 ** Usually, the default mutex implementations provided by SQLite are | |
| 4857 ** sufficient, however the user has the option of substituting a custom | |
| 4858 ** implementation for specialized deployments or systems for which SQLite | |
| 4859 ** does not provide a suitable implementation. In this case, the user | |
| 4860 ** creates and populates an instance of this structure to pass | |
| 4861 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. | |
| 4862 ** Additionally, an instance of this structure can be used as an | |
| 4863 ** output variable when querying the system for the current mutex | |
| 4864 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. | |
| 4865 ** | |
| 4866 ** The xMutexInit method defined by this structure is invoked as | |
| 4867 ** part of system initialization by the sqlite3_initialize() function. | |
| 4868 ** {H17001} The xMutexInit routine shall be called by SQLite once for each | |
| 4869 ** effective call to [sqlite3_initialize()]. | |
| 4870 ** | |
| 4871 ** The xMutexEnd method defined by this structure is invoked as | |
| 4872 ** part of system shutdown by the sqlite3_shutdown() function. The | |
| 4873 ** implementation of this method is expected to release all outstanding | |
| 4874 ** resources obtained by the mutex methods implementation, especially | |
| 4875 ** those obtained by the xMutexInit method. {H17003} The xMutexEnd() | |
| 4876 ** interface shall be invoked once for each call to [sqlite3_shutdown()]. | |
| 4877 ** | |
| 4878 ** The remaining seven methods defined by this structure (xMutexAlloc, | |
| 4879 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and | |
| 4880 ** xMutexNotheld) implement the following interfaces (respectively): | |
| 4881 ** | |
| 4882 ** <ul> | |
| 4883 ** <li> [sqlite3_mutex_alloc()] </li> | |
| 4884 ** <li> [sqlite3_mutex_free()] </li> | |
| 4885 ** <li> [sqlite3_mutex_enter()] </li> | |
| 4886 ** <li> [sqlite3_mutex_try()] </li> | |
| 4887 ** <li> [sqlite3_mutex_leave()] </li> | |
| 4888 ** <li> [sqlite3_mutex_held()] </li> | |
| 4889 ** <li> [sqlite3_mutex_notheld()] </li> | |
| 4890 ** </ul> | |
| 4891 ** | |
| 4892 ** The only difference is that the public sqlite3_XXX functions enumerated | |
| 4893 ** above silently ignore any invocations that pass a NULL pointer instead | |
| 4894 ** of a valid mutex handle. The implementations of the methods defined | |
| 4895 ** by this structure are not required to handle this case, the results | |
| 4896 ** of passing a NULL pointer instead of a valid mutex handle are undefined | |
| 4897 ** (i.e. it is acceptable to provide an implementation that segfaults if | |
| 4898 ** it is passed a NULL pointer). | |
| 4899 ** | |
| 4900 ** The xMutexInit() method must be threadsafe. It must be harmless to | |
| 4901 ** invoke xMutexInit() mutiple times within the same process and without | |
| 4902 ** intervening calls to xMutexEnd(). Second and subsequent calls to | |
| 4903 ** xMutexInit() must be no-ops. | |
| 4904 ** | |
| 4905 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] | |
| 4906 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory | |
| 4907 ** allocation for a static mutex. However xMutexAlloc() may use SQLite | |
| 4908 ** memory allocation for a fast or recursive mutex. | |
| 4909 ** | |
| 4910 ** SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is | |
| 4911 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. | |
| 4912 ** If xMutexInit fails in any way, it is expected to clean up after itself | |
| 4913 ** prior to returning. | |
| 4914 */ | |
| 4915 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; | |
| 4916 struct sqlite3_mutex_methods { | |
| 4917 int (*xMutexInit)(void); | |
| 4918 int (*xMutexEnd)(void); | |
| 4919 sqlite3_mutex *(*xMutexAlloc)(int); | |
| 4920 void (*xMutexFree)(sqlite3_mutex *); | |
| 4921 void (*xMutexEnter)(sqlite3_mutex *); | |
| 4922 int (*xMutexTry)(sqlite3_mutex *); | |
| 4923 void (*xMutexLeave)(sqlite3_mutex *); | |
| 4924 int (*xMutexHeld)(sqlite3_mutex *); | |
| 4925 int (*xMutexNotheld)(sqlite3_mutex *); | |
| 4926 }; | |
| 4927 | |
| 4928 /* | |
| 4929 ** CAPI3REF: Mutex Verification Routines {H17080} <S20130> <S30800> | |
| 4930 ** | |
| 4931 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines | |
| 4932 ** are intended for use inside assert() statements. {H17081} The SQLite core | |
| 4933 ** never uses these routines except inside an assert() and applications | |
| 4934 ** are advised to follow the lead of the core. {H17082} The core only | |
| 4935 ** provides implementations for these routines when it is compiled | |
| 4936 ** with the SQLITE_DEBUG flag. {A17087} External mutex implementations | |
| 4937 ** are only required to provide these routines if SQLITE_DEBUG is | |
| 4938 ** defined and if NDEBUG is not defined. | |
| 4939 ** | |
| 4940 ** {H17083} These routines should return true if the mutex in their argument | |
| 4941 ** is held or not held, respectively, by the calling thread. | |
| 4942 ** | |
| 4943 ** {X17084} The implementation is not required to provided versions of these | |
| 4944 ** routines that actually work. If the implementation does not provide working | |
| 4945 ** versions of these routines, it should at least provide stubs that always | |
| 4946 ** return true so that one does not get spurious assertion failures. | |
| 4947 ** | |
| 4948 ** {H17085} If the argument to sqlite3_mutex_held() is a NULL pointer then | |
| 4949 ** the routine should return 1. {END} This seems counter-intuitive since | |
| 4950 ** clearly the mutex cannot be held if it does not exist. But the | |
| 4951 ** the reason the mutex does not exist is because the build is not | |
| 4952 ** using mutexes. And we do not want the assert() containing the | |
| 4953 ** call to sqlite3_mutex_held() to fail, so a non-zero return is | |
| 4954 ** the appropriate thing to do. {H17086} The sqlite3_mutex_notheld() | |
| 4955 ** interface should also return 1 when given a NULL pointer. | |
| 4956 */ | |
| 4957 int sqlite3_mutex_held(sqlite3_mutex*); | |
| 4958 int sqlite3_mutex_notheld(sqlite3_mutex*); | |
| 4959 | |
| 4960 /* | |
| 4961 ** CAPI3REF: Mutex Types {H17001} <H17000> | |
| 4962 ** | |
| 4963 ** The [sqlite3_mutex_alloc()] interface takes a single argument | |
| 4964 ** which is one of these integer constants. | |
| 4965 ** | |
| 4966 ** The set of static mutexes may change from one SQLite release to the | |
| 4967 ** next. Applications that override the built-in mutex logic must be | |
| 4968 ** prepared to accommodate additional static mutexes. | |
| 4969 */ | |
| 4970 #define SQLITE_MUTEX_FAST 0 | |
| 4971 #define SQLITE_MUTEX_RECURSIVE 1 | |
| 4972 #define SQLITE_MUTEX_STATIC_MASTER 2 | |
| 4973 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ | |
| 4974 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ | |
| 4975 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ | |
| 4976 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ | |
| 4977 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ | |
| 4978 #define SQLITE_MUTEX_STATIC_LRU2 7 /* lru page list */ | |
| 4979 | |
| 4980 /* | |
| 4981 ** CAPI3REF: Retrieve the mutex for a database connection {H17002} <H17000> | |
| 4982 ** | |
| 4983 ** This interface returns a pointer the [sqlite3_mutex] object that | |
| 4984 ** serializes access to the [database connection] given in the argument | |
| 4985 ** when the [threading mode] is Serialized. | |
| 4986 ** If the [threading mode] is Single-thread or Multi-thread then this | |
| 4987 ** routine returns a NULL pointer. | |
| 4988 */ | |
| 4989 sqlite3_mutex *sqlite3_db_mutex(sqlite3*); | |
| 4990 | |
| 4991 /* | |
| 4992 ** CAPI3REF: Low-Level Control Of Database Files {H11300} <S30800> | |
| 4993 ** | |
| 4994 ** {H11301} The [sqlite3_file_control()] interface makes a direct call to the | |
| 4995 ** xFileControl method for the [sqlite3_io_methods] object associated | |
| 4996 ** with a particular database identified by the second argument. {H11302} The | |
| 4997 ** name of the database is the name assigned to the database by the | |
| 4998 ** <a href="lang_attach.html">ATTACH</a> SQL command that opened the | |
| 4999 ** database. {H11303} To control the main database file, use the name "main" | |
| 5000 ** or a NULL pointer. {H11304} The third and fourth parameters to this routine | |
| 5001 ** are passed directly through to the second and third parameters of | |
| 5002 ** the xFileControl method. {H11305} The return value of the xFileControl | |
| 5003 ** method becomes the return value of this routine. | |
| 5004 ** | |
| 5005 ** {H11306} If the second parameter (zDbName) does not match the name of any | |
| 5006 ** open database file, then SQLITE_ERROR is returned. {H11307} This error | |
| 5007 ** code is not remembered and will not be recalled by [sqlite3_errcode()] | |
| 5008 ** or [sqlite3_errmsg()]. {A11308} The underlying xFileControl method might | |
| 5009 ** also return SQLITE_ERROR. {A11309} There is no way to distinguish between | |
| 5010 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying | |
| 5011 ** xFileControl method. {END} | |
| 5012 ** | |
| 5013 ** See also: [SQLITE_FCNTL_LOCKSTATE] | |
| 5014 */ | |
| 5015 int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); | |
| 5016 | |
| 5017 /* | |
| 5018 ** CAPI3REF: Testing Interface {H11400} <S30800> | |
| 5019 ** | |
| 5020 ** The sqlite3_test_control() interface is used to read out internal | |
| 5021 ** state of SQLite and to inject faults into SQLite for testing | |
| 5022 ** purposes. The first parameter is an operation code that determines | |
| 5023 ** the number, meaning, and operation of all subsequent parameters. | |
| 5024 ** | |
| 5025 ** This interface is not for use by applications. It exists solely | |
| 5026 ** for verifying the correct operation of the SQLite library. Depending | |
| 5027 ** on how the SQLite library is compiled, this interface might not exist. | |
| 5028 ** | |
| 5029 ** The details of the operation codes, their meanings, the parameters | |
| 5030 ** they take, and what they do are all subject to change without notice. | |
| 5031 ** Unlike most of the SQLite API, this function is not guaranteed to | |
| 5032 ** operate consistently from one release to the next. | |
| 5033 */ | |
| 5034 int sqlite3_test_control(int op, ...); | |
| 5035 | |
| 5036 /* | |
| 5037 ** CAPI3REF: Testing Interface Operation Codes {H11410} <H11400> | |
| 5038 ** | |
| 5039 ** These constants are the valid operation code parameters used | |
| 5040 ** as the first argument to [sqlite3_test_control()]. | |
| 5041 ** | |
| 5042 ** These parameters and their meanings are subject to change | |
| 5043 ** without notice. These values are for testing purposes only. | |
| 5044 ** Applications should not use any of these parameters or the | |
| 5045 ** [sqlite3_test_control()] interface. | |
| 5046 */ | |
| 5047 #define SQLITE_TESTCTRL_PRNG_SAVE 5 | |
| 5048 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 | |
| 5049 #define SQLITE_TESTCTRL_PRNG_RESET 7 | |
| 5050 #define SQLITE_TESTCTRL_BITVEC_TEST 8 | |
| 5051 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 | |
| 5052 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 | |
| 5053 #define SQLITE_TESTCTRL_PENDING_BYTE 11 | |
| 5054 #define SQLITE_TESTCTRL_ASSERT 12 | |
| 5055 #define SQLITE_TESTCTRL_ALWAYS 13 | |
| 5056 #define SQLITE_TESTCTRL_RESERVE 14 | |
| 5057 | |
| 5058 /* | |
| 5059 ** CAPI3REF: SQLite Runtime Status {H17200} <S60200> | |
| 5060 ** EXPERIMENTAL | |
| 5061 ** | |
| 5062 ** This interface is used to retrieve runtime status information | |
| 5063 ** about the preformance of SQLite, and optionally to reset various | |
| 5064 ** highwater marks. The first argument is an integer code for | |
| 5065 ** the specific parameter to measure. Recognized integer codes | |
| 5066 ** are of the form [SQLITE_STATUS_MEMORY_USED | SQLITE_STATUS_...]. | |
| 5067 ** The current value of the parameter is returned into *pCurrent. | |
| 5068 ** The highest recorded value is returned in *pHighwater. If the | |
| 5069 ** resetFlag is true, then the highest record value is reset after | |
| 5070 ** *pHighwater is written. Some parameters do not record the highest | |
| 5071 ** value. For those parameters | |
| 5072 ** nothing is written into *pHighwater and the resetFlag is ignored. | |
| 5073 ** Other parameters record only the highwater mark and not the current | |
| 5074 ** value. For these latter parameters nothing is written into *pCurrent. | |
| 5075 ** | |
| 5076 ** This routine returns SQLITE_OK on success and a non-zero | |
| 5077 ** [error code] on failure. | |
| 5078 ** | |
| 5079 ** This routine is threadsafe but is not atomic. This routine can be | |
| 5080 ** called while other threads are running the same or different SQLite | |
| 5081 ** interfaces. However the values returned in *pCurrent and | |
| 5082 ** *pHighwater reflect the status of SQLite at different points in time | |
| 5083 ** and it is possible that another thread might change the parameter | |
| 5084 ** in between the times when *pCurrent and *pHighwater are written. | |
| 5085 ** | |
| 5086 ** See also: [sqlite3_db_status()] | |
| 5087 */ | |
| 5088 SQLITE_EXPERIMENTAL int sqlite3_status(int op, int *pCurrent, int *pHighwater, i
nt resetFlag); | |
| 5089 | |
| 5090 | |
| 5091 /* | |
| 5092 ** CAPI3REF: Status Parameters {H17250} <H17200> | |
| 5093 ** EXPERIMENTAL | |
| 5094 ** | |
| 5095 ** These integer constants designate various run-time status parameters | |
| 5096 ** that can be returned by [sqlite3_status()]. | |
| 5097 ** | |
| 5098 ** <dl> | |
| 5099 ** <dt>SQLITE_STATUS_MEMORY_USED</dt> | |
| 5100 ** <dd>This parameter is the current amount of memory checked out | |
| 5101 ** using [sqlite3_malloc()], either directly or indirectly. The | |
| 5102 ** figure includes calls made to [sqlite3_malloc()] by the application | |
| 5103 ** and internal memory usage by the SQLite library. Scratch memory | |
| 5104 ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache | |
| 5105 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in | |
| 5106 ** this parameter. The amount returned is the sum of the allocation | |
| 5107 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd> | |
| 5108 ** | |
| 5109 ** <dt>SQLITE_STATUS_MALLOC_SIZE</dt> | |
| 5110 ** <dd>This parameter records the largest memory allocation request | |
| 5111 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their | |
| 5112 ** internal equivalents). Only the value returned in the | |
| 5113 ** *pHighwater parameter to [sqlite3_status()] is of interest. | |
| 5114 ** The value written into the *pCurrent parameter is undefined.</dd> | |
| 5115 ** | |
| 5116 ** <dt>SQLITE_STATUS_PAGECACHE_USED</dt> | |
| 5117 ** <dd>This parameter returns the number of pages used out of the | |
| 5118 ** [pagecache memory allocator] that was configured using | |
| 5119 ** [SQLITE_CONFIG_PAGECACHE]. The | |
| 5120 ** value returned is in pages, not in bytes.</dd> | |
| 5121 ** | |
| 5122 ** <dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> | |
| 5123 ** <dd>This parameter returns the number of bytes of page cache | |
| 5124 ** allocation which could not be statisfied by the [SQLITE_CONFIG_PAGECACHE] | |
| 5125 ** buffer and where forced to overflow to [sqlite3_malloc()]. The | |
| 5126 ** returned value includes allocations that overflowed because they | |
| 5127 ** where too large (they were larger than the "sz" parameter to | |
| 5128 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because | |
| 5129 ** no space was left in the page cache.</dd> | |
| 5130 ** | |
| 5131 ** <dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> | |
| 5132 ** <dd>This parameter records the largest memory allocation request | |
| 5133 ** handed to [pagecache memory allocator]. Only the value returned in the | |
| 5134 ** *pHighwater parameter to [sqlite3_status()] is of interest. | |
| 5135 ** The value written into the *pCurrent parameter is undefined.</dd> | |
| 5136 ** | |
| 5137 ** <dt>SQLITE_STATUS_SCRATCH_USED</dt> | |
| 5138 ** <dd>This parameter returns the number of allocations used out of the | |
| 5139 ** [scratch memory allocator] configured using | |
| 5140 ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not | |
| 5141 ** in bytes. Since a single thread may only have one scratch allocation | |
| 5142 ** outstanding at time, this parameter also reports the number of threads | |
| 5143 ** using scratch memory at the same time.</dd> | |
| 5144 ** | |
| 5145 ** <dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> | |
| 5146 ** <dd>This parameter returns the number of bytes of scratch memory | |
| 5147 ** allocation which could not be statisfied by the [SQLITE_CONFIG_SCRATCH] | |
| 5148 ** buffer and where forced to overflow to [sqlite3_malloc()]. The values | |
| 5149 ** returned include overflows because the requested allocation was too | |
| 5150 ** larger (that is, because the requested allocation was larger than the | |
| 5151 ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer | |
| 5152 ** slots were available. | |
| 5153 ** </dd> | |
| 5154 ** | |
| 5155 ** <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> | |
| 5156 ** <dd>This parameter records the largest memory allocation request | |
| 5157 ** handed to [scratch memory allocator]. Only the value returned in the | |
| 5158 ** *pHighwater parameter to [sqlite3_status()] is of interest. | |
| 5159 ** The value written into the *pCurrent parameter is undefined.</dd> | |
| 5160 ** | |
| 5161 ** <dt>SQLITE_STATUS_PARSER_STACK</dt> | |
| 5162 ** <dd>This parameter records the deepest parser stack. It is only | |
| 5163 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd> | |
| 5164 ** </dl> | |
| 5165 ** | |
| 5166 ** New status parameters may be added from time to time. | |
| 5167 */ | |
| 5168 #define SQLITE_STATUS_MEMORY_USED 0 | |
| 5169 #define SQLITE_STATUS_PAGECACHE_USED 1 | |
| 5170 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 | |
| 5171 #define SQLITE_STATUS_SCRATCH_USED 3 | |
| 5172 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 | |
| 5173 #define SQLITE_STATUS_MALLOC_SIZE 5 | |
| 5174 #define SQLITE_STATUS_PARSER_STACK 6 | |
| 5175 #define SQLITE_STATUS_PAGECACHE_SIZE 7 | |
| 5176 #define SQLITE_STATUS_SCRATCH_SIZE 8 | |
| 5177 | |
| 5178 /* | |
| 5179 ** CAPI3REF: Database Connection Status {H17500} <S60200> | |
| 5180 ** EXPERIMENTAL | |
| 5181 ** | |
| 5182 ** This interface is used to retrieve runtime status information | |
| 5183 ** about a single [database connection]. The first argument is the | |
| 5184 ** database connection object to be interrogated. The second argument | |
| 5185 ** is the parameter to interrogate. Currently, the only allowed value | |
| 5186 ** for the second parameter is [SQLITE_DBSTATUS_LOOKASIDE_USED]. | |
| 5187 ** Additional options will likely appear in future releases of SQLite. | |
| 5188 ** | |
| 5189 ** The current value of the requested parameter is written into *pCur | |
| 5190 ** and the highest instantaneous value is written into *pHiwtr. If | |
| 5191 ** the resetFlg is true, then the highest instantaneous value is | |
| 5192 ** reset back down to the current value. | |
| 5193 ** | |
| 5194 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. | |
| 5195 */ | |
| 5196 SQLITE_EXPERIMENTAL int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiw
tr, int resetFlg); | |
| 5197 | |
| 5198 /* | |
| 5199 ** CAPI3REF: Status Parameters for database connections {H17520} <H17500> | |
| 5200 ** EXPERIMENTAL | |
| 5201 ** | |
| 5202 ** These constants are the available integer "verbs" that can be passed as | |
| 5203 ** the second argument to the [sqlite3_db_status()] interface. | |
| 5204 ** | |
| 5205 ** New verbs may be added in future releases of SQLite. Existing verbs | |
| 5206 ** might be discontinued. Applications should check the return code from | |
| 5207 ** [sqlite3_db_status()] to make sure that the call worked. | |
| 5208 ** The [sqlite3_db_status()] interface will return a non-zero error code | |
| 5209 ** if a discontinued or unsupported verb is invoked. | |
| 5210 ** | |
| 5211 ** <dl> | |
| 5212 ** <dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> | |
| 5213 ** <dd>This parameter returns the number of lookaside memory slots currently | |
| 5214 ** checked out.</dd> | |
| 5215 ** </dl> | |
| 5216 */ | |
| 5217 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 | |
| 5218 | |
| 5219 | |
| 5220 /* | |
| 5221 ** CAPI3REF: Prepared Statement Status {H17550} <S60200> | |
| 5222 ** EXPERIMENTAL | |
| 5223 ** | |
| 5224 ** Each prepared statement maintains various | |
| 5225 ** [SQLITE_STMTSTATUS_SORT | counters] that measure the number | |
| 5226 ** of times it has performed specific operations. These counters can | |
| 5227 ** be used to monitor the performance characteristics of the prepared | |
| 5228 ** statements. For example, if the number of table steps greatly exceeds | |
| 5229 ** the number of table searches or result rows, that would tend to indicate | |
| 5230 ** that the prepared statement is using a full table scan rather than | |
| 5231 ** an index. | |
| 5232 ** | |
| 5233 ** This interface is used to retrieve and reset counter values from | |
| 5234 ** a [prepared statement]. The first argument is the prepared statement | |
| 5235 ** object to be interrogated. The second argument | |
| 5236 ** is an integer code for a specific [SQLITE_STMTSTATUS_SORT | counter] | |
| 5237 ** to be interrogated. | |
| 5238 ** The current value of the requested counter is returned. | |
| 5239 ** If the resetFlg is true, then the counter is reset to zero after this | |
| 5240 ** interface call returns. | |
| 5241 ** | |
| 5242 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. | |
| 5243 */ | |
| 5244 SQLITE_EXPERIMENTAL int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); | |
| 5245 | |
| 5246 /* | |
| 5247 ** CAPI3REF: Status Parameters for prepared statements {H17570} <H17550> | |
| 5248 ** EXPERIMENTAL | |
| 5249 ** | |
| 5250 ** These preprocessor macros define integer codes that name counter | |
| 5251 ** values associated with the [sqlite3_stmt_status()] interface. | |
| 5252 ** The meanings of the various counters are as follows: | |
| 5253 ** | |
| 5254 ** <dl> | |
| 5255 ** <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> | |
| 5256 ** <dd>This is the number of times that SQLite has stepped forward in | |
| 5257 ** a table as part of a full table scan. Large numbers for this counter | |
| 5258 ** may indicate opportunities for performance improvement through | |
| 5259 ** careful use of indices.</dd> | |
| 5260 ** | |
| 5261 ** <dt>SQLITE_STMTSTATUS_SORT</dt> | |
| 5262 ** <dd>This is the number of sort operations that have occurred. | |
| 5263 ** A non-zero value in this counter may indicate an opportunity to | |
| 5264 ** improvement performance through careful use of indices.</dd> | |
| 5265 ** | |
| 5266 ** </dl> | |
| 5267 */ | |
| 5268 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 | |
| 5269 #define SQLITE_STMTSTATUS_SORT 2 | |
| 5270 | |
| 5271 /* | |
| 5272 ** CAPI3REF: Custom Page Cache Object | |
| 5273 ** EXPERIMENTAL | |
| 5274 ** | |
| 5275 ** The sqlite3_pcache type is opaque. It is implemented by | |
| 5276 ** the pluggable module. The SQLite core has no knowledge of | |
| 5277 ** its size or internal structure and never deals with the | |
| 5278 ** sqlite3_pcache object except by holding and passing pointers | |
| 5279 ** to the object. | |
| 5280 ** | |
| 5281 ** See [sqlite3_pcache_methods] for additional information. | |
| 5282 */ | |
| 5283 typedef struct sqlite3_pcache sqlite3_pcache; | |
| 5284 | |
| 5285 /* | |
| 5286 ** CAPI3REF: Application Defined Page Cache. | |
| 5287 ** KEYWORDS: {page cache} | |
| 5288 ** EXPERIMENTAL | |
| 5289 ** | |
| 5290 ** The [sqlite3_config]([SQLITE_CONFIG_PCACHE], ...) interface can | |
| 5291 ** register an alternative page cache implementation by passing in an | |
| 5292 ** instance of the sqlite3_pcache_methods structure. The majority of the | |
| 5293 ** heap memory used by SQLite is used by the page cache to cache data read | |
| 5294 ** from, or ready to be written to, the database file. By implementing a | |
| 5295 ** custom page cache using this API, an application can control more | |
| 5296 ** precisely the amount of memory consumed by SQLite, the way in which | |
| 5297 ** that memory is allocated and released, and the policies used to | |
| 5298 ** determine exactly which parts of a database file are cached and for | |
| 5299 ** how long. | |
| 5300 ** | |
| 5301 ** The contents of the sqlite3_pcache_methods structure are copied to an | |
| 5302 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence | |
| 5303 ** the application may discard the parameter after the call to | |
| 5304 ** [sqlite3_config()] returns. | |
| 5305 ** | |
| 5306 ** The xInit() method is called once for each call to [sqlite3_initialize()] | |
| 5307 ** (usually only once during the lifetime of the process). It is passed | |
| 5308 ** a copy of the sqlite3_pcache_methods.pArg value. It can be used to set | |
| 5309 ** up global structures and mutexes required by the custom page cache | |
| 5310 ** implementation. | |
| 5311 ** | |
| 5312 ** The xShutdown() method is called from within [sqlite3_shutdown()], | |
| 5313 ** if the application invokes this API. It can be used to clean up | |
| 5314 ** any outstanding resources before process shutdown, if required. | |
| 5315 ** | |
| 5316 ** SQLite holds a [SQLITE_MUTEX_RECURSIVE] mutex when it invokes | |
| 5317 ** the xInit method, so the xInit method need not be threadsafe. The | |
| 5318 ** xShutdown method is only called from [sqlite3_shutdown()] so it does | |
| 5319 ** not need to be threadsafe either. All other methods must be threadsafe | |
| 5320 ** in multithreaded applications. | |
| 5321 ** | |
| 5322 ** SQLite will never invoke xInit() more than once without an intervening | |
| 5323 ** call to xShutdown(). | |
| 5324 ** | |
| 5325 ** The xCreate() method is used to construct a new cache instance. SQLite | |
| 5326 ** will typically create one cache instance for each open database file, | |
| 5327 ** though this is not guaranteed. The | |
| 5328 ** first parameter, szPage, is the size in bytes of the pages that must | |
| 5329 ** be allocated by the cache. szPage will not be a power of two. szPage | |
| 5330 ** will the page size of the database file that is to be cached plus an | |
| 5331 ** increment (here called "R") of about 100 or 200. SQLite will use the | |
| 5332 ** extra R bytes on each page to store metadata about the underlying | |
| 5333 ** database page on disk. The value of R depends | |
| 5334 ** on the SQLite version, the target platform, and how SQLite was compiled. | |
| 5335 ** R is constant for a particular build of SQLite. The second argument to | |
| 5336 ** xCreate(), bPurgeable, is true if the cache being created will | |
| 5337 ** be used to cache database pages of a file stored on disk, or | |
| 5338 ** false if it is used for an in-memory database. The cache implementation | |
| 5339 ** does not have to do anything special based with the value of bPurgeable; | |
| 5340 ** it is purely advisory. On a cache where bPurgeable is false, SQLite will | |
| 5341 ** never invoke xUnpin() except to deliberately delete a page. | |
| 5342 ** In other words, a cache created with bPurgeable set to false will | |
| 5343 ** never contain any unpinned pages. | |
| 5344 ** | |
| 5345 ** The xCachesize() method may be called at any time by SQLite to set the | |
| 5346 ** suggested maximum cache-size (number of pages stored by) the cache | |
| 5347 ** instance passed as the first argument. This is the value configured using | |
| 5348 ** the SQLite "[PRAGMA cache_size]" command. As with the bPurgeable parameter, | |
| 5349 ** the implementation is not required to do anything with this | |
| 5350 ** value; it is advisory only. | |
| 5351 ** | |
| 5352 ** The xPagecount() method should return the number of pages currently | |
| 5353 ** stored in the cache. | |
| 5354 ** | |
| 5355 ** The xFetch() method is used to fetch a page and return a pointer to it. | |
| 5356 ** A 'page', in this context, is a buffer of szPage bytes aligned at an | |
| 5357 ** 8-byte boundary. The page to be fetched is determined by the key. The | |
| 5358 ** mimimum key value is 1. After it has been retrieved using xFetch, the page | |
| 5359 ** is considered to be "pinned". | |
| 5360 ** | |
| 5361 ** If the requested page is already in the page cache, then the page cache | |
| 5362 ** implementation must return a pointer to the page buffer with its content | |
| 5363 ** intact. If the requested page is not already in the cache, then the | |
| 5364 ** behavior of the cache implementation is determined by the value of the | |
| 5365 ** createFlag parameter passed to xFetch, according to the following table: | |
| 5366 ** | |
| 5367 ** <table border=1 width=85% align=center> | |
| 5368 ** <tr><th> createFlag <th> Behaviour when page is not already in cache | |
| 5369 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. | |
| 5370 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. | |
| 5371 ** Otherwise return NULL. | |
| 5372 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return | |
| 5373 ** NULL if allocating a new page is effectively impossible. | |
| 5374 ** </table> | |
| 5375 ** | |
| 5376 ** SQLite will normally invoke xFetch() with a createFlag of 0 or 1. If | |
| 5377 ** a call to xFetch() with createFlag==1 returns NULL, then SQLite will | |
| 5378 ** attempt to unpin one or more cache pages by spilling the content of | |
| 5379 ** pinned pages to disk and synching the operating system disk cache. After | |
| 5380 ** attempting to unpin pages, the xFetch() method will be invoked again with | |
| 5381 ** a createFlag of 2. | |
| 5382 ** | |
| 5383 ** xUnpin() is called by SQLite with a pointer to a currently pinned page | |
| 5384 ** as its second argument. If the third parameter, discard, is non-zero, | |
| 5385 ** then the page should be evicted from the cache. In this case SQLite | |
| 5386 ** assumes that the next time the page is retrieved from the cache using | |
| 5387 ** the xFetch() method, it will be zeroed. If the discard parameter is | |
| 5388 ** zero, then the page is considered to be unpinned. The cache implementation | |
| 5389 ** may choose to evict unpinned pages at any time. | |
| 5390 ** | |
| 5391 ** The cache is not required to perform any reference counting. A single | |
| 5392 ** call to xUnpin() unpins the page regardless of the number of prior calls | |
| 5393 ** to xFetch(). | |
| 5394 ** | |
| 5395 ** The xRekey() method is used to change the key value associated with the | |
| 5396 ** page passed as the second argument from oldKey to newKey. If the cache | |
| 5397 ** previously contains an entry associated with newKey, it should be | |
| 5398 ** discarded. Any prior cache entry associated with newKey is guaranteed not | |
| 5399 ** to be pinned. | |
| 5400 ** | |
| 5401 ** When SQLite calls the xTruncate() method, the cache must discard all | |
| 5402 ** existing cache entries with page numbers (keys) greater than or equal | |
| 5403 ** to the value of the iLimit parameter passed to xTruncate(). If any | |
| 5404 ** of these pages are pinned, they are implicitly unpinned, meaning that | |
| 5405 ** they can be safely discarded. | |
| 5406 ** | |
| 5407 ** The xDestroy() method is used to delete a cache allocated by xCreate(). | |
| 5408 ** All resources associated with the specified cache should be freed. After | |
| 5409 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] | |
| 5410 ** handle invalid, and will not use it with any other sqlite3_pcache_methods | |
| 5411 ** functions. | |
| 5412 */ | |
| 5413 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; | |
| 5414 struct sqlite3_pcache_methods { | |
| 5415 void *pArg; | |
| 5416 int (*xInit)(void*); | |
| 5417 void (*xShutdown)(void*); | |
| 5418 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); | |
| 5419 void (*xCachesize)(sqlite3_pcache*, int nCachesize); | |
| 5420 int (*xPagecount)(sqlite3_pcache*); | |
| 5421 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); | |
| 5422 void (*xUnpin)(sqlite3_pcache*, void*, int discard); | |
| 5423 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); | |
| 5424 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); | |
| 5425 void (*xDestroy)(sqlite3_pcache*); | |
| 5426 }; | |
| 5427 | |
| 5428 /* | |
| 5429 ** CAPI3REF: Online Backup Object | |
| 5430 ** EXPERIMENTAL | |
| 5431 ** | |
| 5432 ** The sqlite3_backup object records state information about an ongoing | |
| 5433 ** online backup operation. The sqlite3_backup object is created by | |
| 5434 ** a call to [sqlite3_backup_init()] and is destroyed by a call to | |
| 5435 ** [sqlite3_backup_finish()]. | |
| 5436 ** | |
| 5437 ** See Also: [Using the SQLite Online Backup API] | |
| 5438 */ | |
| 5439 typedef struct sqlite3_backup sqlite3_backup; | |
| 5440 | |
| 5441 /* | |
| 5442 ** CAPI3REF: Online Backup API. | |
| 5443 ** EXPERIMENTAL | |
| 5444 ** | |
| 5445 ** This API is used to overwrite the contents of one database with that | |
| 5446 ** of another. It is useful either for creating backups of databases or | |
| 5447 ** for copying in-memory databases to or from persistent files. | |
| 5448 ** | |
| 5449 ** See Also: [Using the SQLite Online Backup API] | |
| 5450 ** | |
| 5451 ** Exclusive access is required to the destination database for the | |
| 5452 ** duration of the operation. However the source database is only | |
| 5453 ** read-locked while it is actually being read, it is not locked | |
| 5454 ** continuously for the entire operation. Thus, the backup may be | |
| 5455 ** performed on a live database without preventing other users from | |
| 5456 ** writing to the database for an extended period of time. | |
| 5457 ** | |
| 5458 ** To perform a backup operation: | |
| 5459 ** <ol> | |
| 5460 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the | |
| 5461 ** backup, | |
| 5462 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer | |
| 5463 ** the data between the two databases, and finally | |
| 5464 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources | |
| 5465 ** associated with the backup operation. | |
| 5466 ** </ol> | |
| 5467 ** There should be exactly one call to sqlite3_backup_finish() for each | |
| 5468 ** successful call to sqlite3_backup_init(). | |
| 5469 ** | |
| 5470 ** <b>sqlite3_backup_init()</b> | |
| 5471 ** | |
| 5472 ** The first two arguments passed to [sqlite3_backup_init()] are the database | |
| 5473 ** handle associated with the destination database and the database name | |
| 5474 ** used to attach the destination database to the handle. The database name | |
| 5475 ** is "main" for the main database, "temp" for the temporary database, or | |
| 5476 ** the name specified as part of the [ATTACH] statement if the destination is | |
| 5477 ** an attached database. The third and fourth arguments passed to | |
| 5478 ** sqlite3_backup_init() identify the [database connection] | |
| 5479 ** and database name used | |
| 5480 ** to access the source database. The values passed for the source and | |
| 5481 ** destination [database connection] parameters must not be the same. | |
| 5482 ** | |
| 5483 ** If an error occurs within sqlite3_backup_init(), then NULL is returned | |
| 5484 ** and an error code and error message written into the [database connection] | |
| 5485 ** passed as the first argument. They may be retrieved using the | |
| 5486 ** [sqlite3_errcode()], [sqlite3_errmsg()], and [sqlite3_errmsg16()] functions. | |
| 5487 ** Otherwise, if successful, a pointer to an [sqlite3_backup] object is | |
| 5488 ** returned. This pointer may be used with the sqlite3_backup_step() and | |
| 5489 ** sqlite3_backup_finish() functions to perform the specified backup | |
| 5490 ** operation. | |
| 5491 ** | |
| 5492 ** <b>sqlite3_backup_step()</b> | |
| 5493 ** | |
| 5494 ** Function [sqlite3_backup_step()] is used to copy up to nPage pages between | |
| 5495 ** the source and destination databases, where nPage is the value of the | |
| 5496 ** second parameter passed to sqlite3_backup_step(). If nPage is a negative | |
| 5497 ** value, all remaining source pages are copied. If the required pages are | |
| 5498 ** succesfully copied, but there are still more pages to copy before the | |
| 5499 ** backup is complete, it returns [SQLITE_OK]. If no error occured and there | |
| 5500 ** are no more pages to copy, then [SQLITE_DONE] is returned. If an error | |
| 5501 ** occurs, then an SQLite error code is returned. As well as [SQLITE_OK] and | |
| 5502 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], | |
| 5503 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an | |
| 5504 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. | |
| 5505 ** | |
| 5506 ** As well as the case where the destination database file was opened for | |
| 5507 ** read-only access, sqlite3_backup_step() may return [SQLITE_READONLY] if | |
| 5508 ** the destination is an in-memory database with a different page size | |
| 5509 ** from the source database. | |
| 5510 ** | |
| 5511 ** If sqlite3_backup_step() cannot obtain a required file-system lock, then | |
| 5512 ** the [sqlite3_busy_handler | busy-handler function] | |
| 5513 ** is invoked (if one is specified). If the | |
| 5514 ** busy-handler returns non-zero before the lock is available, then | |
| 5515 ** [SQLITE_BUSY] is returned to the caller. In this case the call to | |
| 5516 ** sqlite3_backup_step() can be retried later. If the source | |
| 5517 ** [database connection] | |
| 5518 ** is being used to write to the source database when sqlite3_backup_step() | |
| 5519 ** is called, then [SQLITE_LOCKED] is returned immediately. Again, in this | |
| 5520 ** case the call to sqlite3_backup_step() can be retried later on. If | |
| 5521 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or | |
| 5522 ** [SQLITE_READONLY] is returned, then | |
| 5523 ** there is no point in retrying the call to sqlite3_backup_step(). These | |
| 5524 ** errors are considered fatal. At this point the application must accept | |
| 5525 ** that the backup operation has failed and pass the backup operation handle | |
| 5526 ** to the sqlite3_backup_finish() to release associated resources. | |
| 5527 ** | |
| 5528 ** Following the first call to sqlite3_backup_step(), an exclusive lock is | |
| 5529 ** obtained on the destination file. It is not released until either | |
| 5530 ** sqlite3_backup_finish() is called or the backup operation is complete | |
| 5531 ** and sqlite3_backup_step() returns [SQLITE_DONE]. Additionally, each time | |
| 5532 ** a call to sqlite3_backup_step() is made a [shared lock] is obtained on | |
| 5533 ** the source database file. This lock is released before the | |
| 5534 ** sqlite3_backup_step() call returns. Because the source database is not | |
| 5535 ** locked between calls to sqlite3_backup_step(), it may be modified mid-way | |
| 5536 ** through the backup procedure. If the source database is modified by an | |
| 5537 ** external process or via a database connection other than the one being | |
| 5538 ** used by the backup operation, then the backup will be transparently | |
| 5539 ** restarted by the next call to sqlite3_backup_step(). If the source | |
| 5540 ** database is modified by the using the same database connection as is used | |
| 5541 ** by the backup operation, then the backup database is transparently | |
| 5542 ** updated at the same time. | |
| 5543 ** | |
| 5544 ** <b>sqlite3_backup_finish()</b> | |
| 5545 ** | |
| 5546 ** Once sqlite3_backup_step() has returned [SQLITE_DONE], or when the | |
| 5547 ** application wishes to abandon the backup operation, the [sqlite3_backup] | |
| 5548 ** object should be passed to sqlite3_backup_finish(). This releases all | |
| 5549 ** resources associated with the backup operation. If sqlite3_backup_step() | |
| 5550 ** has not yet returned [SQLITE_DONE], then any active write-transaction on the | |
| 5551 ** destination database is rolled back. The [sqlite3_backup] object is invalid | |
| 5552 ** and may not be used following a call to sqlite3_backup_finish(). | |
| 5553 ** | |
| 5554 ** The value returned by sqlite3_backup_finish is [SQLITE_OK] if no error | |
| 5555 ** occurred, regardless or whether or not sqlite3_backup_step() was called | |
| 5556 ** a sufficient number of times to complete the backup operation. Or, if | |
| 5557 ** an out-of-memory condition or IO error occured during a call to | |
| 5558 ** sqlite3_backup_step() then [SQLITE_NOMEM] or an | |
| 5559 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] error code | |
| 5560 ** is returned. In this case the error code and an error message are | |
| 5561 ** written to the destination [database connection]. | |
| 5562 ** | |
| 5563 ** A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() is | |
| 5564 ** not a permanent error and does not affect the return value of | |
| 5565 ** sqlite3_backup_finish(). | |
| 5566 ** | |
| 5567 ** <b>sqlite3_backup_remaining(), sqlite3_backup_pagecount()</b> | |
| 5568 ** | |
| 5569 ** Each call to sqlite3_backup_step() sets two values stored internally | |
| 5570 ** by an [sqlite3_backup] object. The number of pages still to be backed | |
| 5571 ** up, which may be queried by sqlite3_backup_remaining(), and the total | |
| 5572 ** number of pages in the source database file, which may be queried by | |
| 5573 ** sqlite3_backup_pagecount(). | |
| 5574 ** | |
| 5575 ** The values returned by these functions are only updated by | |
| 5576 ** sqlite3_backup_step(). If the source database is modified during a backup | |
| 5577 ** operation, then the values are not updated to account for any extra | |
| 5578 ** pages that need to be updated or the size of the source database file | |
| 5579 ** changing. | |
| 5580 ** | |
| 5581 ** <b>Concurrent Usage of Database Handles</b> | |
| 5582 ** | |
| 5583 ** The source [database connection] may be used by the application for other | |
| 5584 ** purposes while a backup operation is underway or being initialized. | |
| 5585 ** If SQLite is compiled and configured to support threadsafe database | |
| 5586 ** connections, then the source database connection may be used concurrently | |
| 5587 ** from within other threads. | |
| 5588 ** | |
| 5589 ** However, the application must guarantee that the destination database | |
| 5590 ** connection handle is not passed to any other API (by any thread) after | |
| 5591 ** sqlite3_backup_init() is called and before the corresponding call to | |
| 5592 ** sqlite3_backup_finish(). Unfortunately SQLite does not currently check | |
| 5593 ** for this, if the application does use the destination [database connection] | |
| 5594 ** for some other purpose during a backup operation, things may appear to | |
| 5595 ** work correctly but in fact be subtly malfunctioning. Use of the | |
| 5596 ** destination database connection while a backup is in progress might | |
| 5597 ** also cause a mutex deadlock. | |
| 5598 ** | |
| 5599 ** Furthermore, if running in [shared cache mode], the application must | |
| 5600 ** guarantee that the shared cache used by the destination database | |
| 5601 ** is not accessed while the backup is running. In practice this means | |
| 5602 ** that the application must guarantee that the file-system file being | |
| 5603 ** backed up to is not accessed by any connection within the process, | |
| 5604 ** not just the specific connection that was passed to sqlite3_backup_init(). | |
| 5605 ** | |
| 5606 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple | |
| 5607 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). | |
| 5608 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() | |
| 5609 ** APIs are not strictly speaking threadsafe. If they are invoked at the | |
| 5610 ** same time as another thread is invoking sqlite3_backup_step() it is | |
| 5611 ** possible that they return invalid values. | |
| 5612 */ | |
| 5613 sqlite3_backup *sqlite3_backup_init( | |
| 5614 sqlite3 *pDest, /* Destination database handle */ | |
| 5615 const char *zDestName, /* Destination database name */ | |
| 5616 sqlite3 *pSource, /* Source database handle */ | |
| 5617 const char *zSourceName /* Source database name */ | |
| 5618 ); | |
| 5619 int sqlite3_backup_step(sqlite3_backup *p, int nPage); | |
| 5620 int sqlite3_backup_finish(sqlite3_backup *p); | |
| 5621 int sqlite3_backup_remaining(sqlite3_backup *p); | |
| 5622 int sqlite3_backup_pagecount(sqlite3_backup *p); | |
| 5623 | |
| 5624 /* | |
| 5625 ** CAPI3REF: Unlock Notification | |
| 5626 ** EXPERIMENTAL | |
| 5627 ** | |
| 5628 ** When running in shared-cache mode, a database operation may fail with | |
| 5629 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or | |
| 5630 ** individual tables within the shared-cache cannot be obtained. See | |
| 5631 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. | |
| 5632 ** This API may be used to register a callback that SQLite will invoke | |
| 5633 ** when the connection currently holding the required lock relinquishes it. | |
| 5634 ** This API is only available if the library was compiled with the | |
| 5635 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. | |
| 5636 ** | |
| 5637 ** See Also: [Using the SQLite Unlock Notification Feature]. | |
| 5638 ** | |
| 5639 ** Shared-cache locks are released when a database connection concludes | |
| 5640 ** its current transaction, either by committing it or rolling it back. | |
| 5641 ** | |
| 5642 ** When a connection (known as the blocked connection) fails to obtain a | |
| 5643 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the | |
| 5644 ** identity of the database connection (the blocking connection) that | |
| 5645 ** has locked the required resource is stored internally. After an | |
| 5646 ** application receives an SQLITE_LOCKED error, it may call the | |
| 5647 ** sqlite3_unlock_notify() method with the blocked connection handle as | |
| 5648 ** the first argument to register for a callback that will be invoked | |
| 5649 ** when the blocking connections current transaction is concluded. The | |
| 5650 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] | |
| 5651 ** call that concludes the blocking connections transaction. | |
| 5652 ** | |
| 5653 ** If sqlite3_unlock_notify() is called in a multi-threaded application, | |
| 5654 ** there is a chance that the blocking connection will have already | |
| 5655 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. | |
| 5656 ** If this happens, then the specified callback is invoked immediately, | |
| 5657 ** from within the call to sqlite3_unlock_notify(). | |
| 5658 ** | |
| 5659 ** If the blocked connection is attempting to obtain a write-lock on a | |
| 5660 ** shared-cache table, and more than one other connection currently holds | |
| 5661 ** a read-lock on the same table, then SQLite arbitrarily selects one of | |
| 5662 ** the other connections to use as the blocking connection. | |
| 5663 ** | |
| 5664 ** There may be at most one unlock-notify callback registered by a | |
| 5665 ** blocked connection. If sqlite3_unlock_notify() is called when the | |
| 5666 ** blocked connection already has a registered unlock-notify callback, | |
| 5667 ** then the new callback replaces the old. If sqlite3_unlock_notify() is | |
| 5668 ** called with a NULL pointer as its second argument, then any existing | |
| 5669 ** unlock-notify callback is cancelled. The blocked connections | |
| 5670 ** unlock-notify callback may also be canceled by closing the blocked | |
| 5671 ** connection using [sqlite3_close()]. | |
| 5672 ** | |
| 5673 ** The unlock-notify callback is not reentrant. If an application invokes | |
| 5674 ** any sqlite3_xxx API functions from within an unlock-notify callback, a | |
| 5675 ** crash or deadlock may be the result. | |
| 5676 ** | |
| 5677 ** Unless deadlock is detected (see below), sqlite3_unlock_notify() always | |
| 5678 ** returns SQLITE_OK. | |
| 5679 ** | |
| 5680 ** <b>Callback Invocation Details</b> | |
| 5681 ** | |
| 5682 ** When an unlock-notify callback is registered, the application provides a | |
| 5683 ** single void* pointer that is passed to the callback when it is invoked. | |
| 5684 ** However, the signature of the callback function allows SQLite to pass | |
| 5685 ** it an array of void* context pointers. The first argument passed to | |
| 5686 ** an unlock-notify callback is a pointer to an array of void* pointers, | |
| 5687 ** and the second is the number of entries in the array. | |
| 5688 ** | |
| 5689 ** When a blocking connections transaction is concluded, there may be | |
| 5690 ** more than one blocked connection that has registered for an unlock-notify | |
| 5691 ** callback. If two or more such blocked connections have specified the | |
| 5692 ** same callback function, then instead of invoking the callback function | |
| 5693 ** multiple times, it is invoked once with the set of void* context pointers | |
| 5694 ** specified by the blocked connections bundled together into an array. | |
| 5695 ** This gives the application an opportunity to prioritize any actions | |
| 5696 ** related to the set of unblocked database connections. | |
| 5697 ** | |
| 5698 ** <b>Deadlock Detection</b> | |
| 5699 ** | |
| 5700 ** Assuming that after registering for an unlock-notify callback a | |
| 5701 ** database waits for the callback to be issued before taking any further | |
| 5702 ** action (a reasonable assumption), then using this API may cause the | |
| 5703 ** application to deadlock. For example, if connection X is waiting for | |
| 5704 ** connection Y's transaction to be concluded, and similarly connection | |
| 5705 ** Y is waiting on connection X's transaction, then neither connection | |
| 5706 ** will proceed and the system may remain deadlocked indefinitely. | |
| 5707 ** | |
| 5708 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock | |
| 5709 ** detection. If a given call to sqlite3_unlock_notify() would put the | |
| 5710 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no | |
| 5711 ** unlock-notify callback is registered. The system is said to be in | |
| 5712 ** a deadlocked state if connection A has registered for an unlock-notify | |
| 5713 ** callback on the conclusion of connection B's transaction, and connection | |
| 5714 ** B has itself registered for an unlock-notify callback when connection | |
| 5715 ** A's transaction is concluded. Indirect deadlock is also detected, so | |
| 5716 ** the system is also considered to be deadlocked if connection B has | |
| 5717 ** registered for an unlock-notify callback on the conclusion of connection | |
| 5718 ** C's transaction, where connection C is waiting on connection A. Any | |
| 5719 ** number of levels of indirection are allowed. | |
| 5720 ** | |
| 5721 ** <b>The "DROP TABLE" Exception</b> | |
| 5722 ** | |
| 5723 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost | |
| 5724 ** always appropriate to call sqlite3_unlock_notify(). There is however, | |
| 5725 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, | |
| 5726 ** SQLite checks if there are any currently executing SELECT statements | |
| 5727 ** that belong to the same connection. If there are, SQLITE_LOCKED is | |
| 5728 ** returned. In this case there is no "blocking connection", so invoking | |
| 5729 ** sqlite3_unlock_notify() results in the unlock-notify callback being | |
| 5730 ** invoked immediately. If the application then re-attempts the "DROP TABLE" | |
| 5731 ** or "DROP INDEX" query, an infinite loop might be the result. | |
| 5732 ** | |
| 5733 ** One way around this problem is to check the extended error code returned | |
| 5734 ** by an sqlite3_step() call. If there is a blocking connection, then the | |
| 5735 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in | |
| 5736 ** the special "DROP TABLE/INDEX" case, the extended error code is just | |
| 5737 ** SQLITE_LOCKED. | |
| 5738 */ | |
| 5739 int sqlite3_unlock_notify( | |
| 5740 sqlite3 *pBlocked, /* Waiting connection */ | |
| 5741 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ | |
| 5742 void *pNotifyArg /* Argument to pass to xNotify */ | |
| 5743 ); | |
| 5744 | |
| 5745 | |
| 5746 /* | |
| 5747 ** CAPI3REF: String Comparison | |
| 5748 ** EXPERIMENTAL | |
| 5749 ** | |
| 5750 ** The [sqlite3_strnicmp()] API allows applications and extensions to | |
| 5751 ** compare the contents of two buffers containing UTF-8 strings in a | |
| 5752 ** case-indendent fashion, using the same definition of case independence | |
| 5753 ** that SQLite uses internally when comparing identifiers. | |
| 5754 */ | |
| 5755 int sqlite3_strnicmp(const char *, const char *, int); | |
| 5756 | |
| 5757 /* | |
| 5758 ** Undo the hack that converts floating point types to integer for | |
| 5759 ** builds on processors without floating point support. | |
| 5760 */ | |
| 5761 #ifdef SQLITE_OMIT_FLOATING_POINT | |
| 5762 # undef double | |
| 5763 #endif | |
| 5764 | |
| 5765 #ifdef __cplusplus | |
| 5766 } /* End of the 'extern "C"' block */ | |
| 5767 #endif | |
| 5768 #endif | |
| OLD | NEW |