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| 1 /* | |
| 2 ** 2007 September 14 | |
| 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 ** | |
| 13 ** OVERVIEW: | |
| 14 ** | |
| 15 ** This file contains some example code demonstrating how the SQLite | |
| 16 ** vfs feature can be used to have SQLite operate directly on an | |
| 17 ** embedded media, without using an intermediate file system. | |
| 18 ** | |
| 19 ** Because this is only a demo designed to run on a workstation, the | |
| 20 ** underlying media is simulated using a regular file-system file. The | |
| 21 ** size of the file is fixed when it is first created (default size 10 MB). | |
| 22 ** From SQLite's point of view, this space is used to store a single | |
| 23 ** database file and the journal file. | |
| 24 ** | |
| 25 ** Any statement journal created is stored in volatile memory obtained | |
| 26 ** from sqlite3_malloc(). Any attempt to create a temporary database file | |
| 27 ** will fail (SQLITE_IOERR). To prevent SQLite from attempting this, | |
| 28 ** it should be configured to store all temporary database files in | |
| 29 ** main memory (see pragma "temp_store" or the SQLITE_TEMP_STORE compile | |
| 30 ** time option). | |
| 31 ** | |
| 32 ** ASSUMPTIONS: | |
| 33 ** | |
| 34 ** After it has been created, the blob file is accessed using the | |
| 35 ** following three functions only: | |
| 36 ** | |
| 37 ** mediaRead(); - Read a 512 byte block from the file. | |
| 38 ** mediaWrite(); - Write a 512 byte block to the file. | |
| 39 ** mediaSync(); - Tell the media hardware to sync. | |
| 40 ** | |
| 41 ** It is assumed that these can be easily implemented by any "real" | |
| 42 ** media vfs driver adapting this code. | |
| 43 ** | |
| 44 ** FILE FORMAT: | |
| 45 ** | |
| 46 ** The basic principle is that the "database file" is stored at the | |
| 47 ** beginning of the 10 MB blob and grows in a forward direction. The | |
| 48 ** "journal file" is stored at the end of the 10MB blob and grows | |
| 49 ** in the reverse direction. If, during a transaction, insufficient | |
| 50 ** space is available to expand either the journal or database file, | |
| 51 ** an SQLITE_FULL error is returned. The database file is never allowed | |
| 52 ** to consume more than 90% of the blob space. If SQLite tries to | |
| 53 ** create a file larger than this, SQLITE_FULL is returned. | |
| 54 ** | |
| 55 ** No allowance is made for "wear-leveling", as is required by. | |
| 56 ** embedded devices in the absence of equivalent hardware features. | |
| 57 ** | |
| 58 ** The first 512 block byte of the file is reserved for storing the | |
| 59 ** size of the "database file". It is updated as part of the sync() | |
| 60 ** operation. On startup, it can only be trusted if no journal file | |
| 61 ** exists. If a journal-file does exist, then it stores the real size | |
| 62 ** of the database region. The second and subsequent blocks store the | |
| 63 ** actual database content. | |
| 64 ** | |
| 65 ** The size of the "journal file" is not stored persistently in the | |
| 66 ** file. When the system is running, the size of the journal file is | |
| 67 ** stored in volatile memory. When recovering from a crash, this vfs | |
| 68 ** reports a very large size for the journal file. The normal journal | |
| 69 ** header and checksum mechanisms serve to prevent SQLite from | |
| 70 ** processing any data that lies past the logical end of the journal. | |
| 71 ** | |
| 72 ** When SQLite calls OsDelete() to delete the journal file, the final | |
| 73 ** 512 bytes of the blob (the area containing the first journal header) | |
| 74 ** are zeroed. | |
| 75 ** | |
| 76 ** LOCKING: | |
| 77 ** | |
| 78 ** File locking is a no-op. Only one connection may be open at any one | |
| 79 ** time using this demo vfs. | |
| 80 */ | |
| 81 | |
| 82 #include "sqlite3.h" | |
| 83 #include <assert.h> | |
| 84 #include <string.h> | |
| 85 | |
| 86 /* | |
| 87 ** Maximum pathname length supported by the fs backend. | |
| 88 */ | |
| 89 #define BLOCKSIZE 512 | |
| 90 #define BLOBSIZE 10485760 | |
| 91 | |
| 92 /* | |
| 93 ** Name used to identify this VFS. | |
| 94 */ | |
| 95 #define FS_VFS_NAME "fs" | |
| 96 | |
| 97 typedef struct fs_real_file fs_real_file; | |
| 98 struct fs_real_file { | |
| 99 sqlite3_file *pFile; | |
| 100 const char *zName; | |
| 101 int nDatabase; /* Current size of database region */ | |
| 102 int nJournal; /* Current size of journal region */ | |
| 103 int nBlob; /* Total size of allocated blob */ | |
| 104 int nRef; /* Number of pointers to this structure */ | |
| 105 fs_real_file *pNext; | |
| 106 fs_real_file **ppThis; | |
| 107 }; | |
| 108 | |
| 109 typedef struct fs_file fs_file; | |
| 110 struct fs_file { | |
| 111 sqlite3_file base; | |
| 112 int eType; | |
| 113 fs_real_file *pReal; | |
| 114 }; | |
| 115 | |
| 116 typedef struct tmp_file tmp_file; | |
| 117 struct tmp_file { | |
| 118 sqlite3_file base; | |
| 119 int nSize; | |
| 120 int nAlloc; | |
| 121 char *zAlloc; | |
| 122 }; | |
| 123 | |
| 124 /* Values for fs_file.eType. */ | |
| 125 #define DATABASE_FILE 1 | |
| 126 #define JOURNAL_FILE 2 | |
| 127 | |
| 128 /* | |
| 129 ** Method declarations for fs_file. | |
| 130 */ | |
| 131 static int fsClose(sqlite3_file*); | |
| 132 static int fsRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); | |
| 133 static int fsWrite(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); | |
| 134 static int fsTruncate(sqlite3_file*, sqlite3_int64 size); | |
| 135 static int fsSync(sqlite3_file*, int flags); | |
| 136 static int fsFileSize(sqlite3_file*, sqlite3_int64 *pSize); | |
| 137 static int fsLock(sqlite3_file*, int); | |
| 138 static int fsUnlock(sqlite3_file*, int); | |
| 139 static int fsCheckReservedLock(sqlite3_file*, int *pResOut); | |
| 140 static int fsFileControl(sqlite3_file*, int op, void *pArg); | |
| 141 static int fsSectorSize(sqlite3_file*); | |
| 142 static int fsDeviceCharacteristics(sqlite3_file*); | |
| 143 | |
| 144 /* | |
| 145 ** Method declarations for tmp_file. | |
| 146 */ | |
| 147 static int tmpClose(sqlite3_file*); | |
| 148 static int tmpRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); | |
| 149 static int tmpWrite(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); | |
| 150 static int tmpTruncate(sqlite3_file*, sqlite3_int64 size); | |
| 151 static int tmpSync(sqlite3_file*, int flags); | |
| 152 static int tmpFileSize(sqlite3_file*, sqlite3_int64 *pSize); | |
| 153 static int tmpLock(sqlite3_file*, int); | |
| 154 static int tmpUnlock(sqlite3_file*, int); | |
| 155 static int tmpCheckReservedLock(sqlite3_file*, int *pResOut); | |
| 156 static int tmpFileControl(sqlite3_file*, int op, void *pArg); | |
| 157 static int tmpSectorSize(sqlite3_file*); | |
| 158 static int tmpDeviceCharacteristics(sqlite3_file*); | |
| 159 | |
| 160 /* | |
| 161 ** Method declarations for fs_vfs. | |
| 162 */ | |
| 163 static int fsOpen(sqlite3_vfs*, const char *, sqlite3_file*, int , int *); | |
| 164 static int fsDelete(sqlite3_vfs*, const char *zName, int syncDir); | |
| 165 static int fsAccess(sqlite3_vfs*, const char *zName, int flags, int *); | |
| 166 static int fsFullPathname(sqlite3_vfs*, const char *zName, int nOut,char *zOut); | |
| 167 static void *fsDlOpen(sqlite3_vfs*, const char *zFilename); | |
| 168 static void fsDlError(sqlite3_vfs*, int nByte, char *zErrMsg); | |
| 169 static void (*fsDlSym(sqlite3_vfs*,void*, const char *zSymbol))(void); | |
| 170 static void fsDlClose(sqlite3_vfs*, void*); | |
| 171 static int fsRandomness(sqlite3_vfs*, int nByte, char *zOut); | |
| 172 static int fsSleep(sqlite3_vfs*, int microseconds); | |
| 173 static int fsCurrentTime(sqlite3_vfs*, double*); | |
| 174 | |
| 175 | |
| 176 typedef struct fs_vfs_t fs_vfs_t; | |
| 177 struct fs_vfs_t { | |
| 178 sqlite3_vfs base; | |
| 179 fs_real_file *pFileList; | |
| 180 sqlite3_vfs *pParent; | |
| 181 }; | |
| 182 | |
| 183 static fs_vfs_t fs_vfs = { | |
| 184 { | |
| 185 1, /* iVersion */ | |
| 186 0, /* szOsFile */ | |
| 187 0, /* mxPathname */ | |
| 188 0, /* pNext */ | |
| 189 FS_VFS_NAME, /* zName */ | |
| 190 0, /* pAppData */ | |
| 191 fsOpen, /* xOpen */ | |
| 192 fsDelete, /* xDelete */ | |
| 193 fsAccess, /* xAccess */ | |
| 194 fsFullPathname, /* xFullPathname */ | |
| 195 fsDlOpen, /* xDlOpen */ | |
| 196 fsDlError, /* xDlError */ | |
| 197 fsDlSym, /* xDlSym */ | |
| 198 fsDlClose, /* xDlClose */ | |
| 199 fsRandomness, /* xRandomness */ | |
| 200 fsSleep, /* xSleep */ | |
| 201 fsCurrentTime, /* xCurrentTime */ | |
| 202 0 /* xCurrentTimeInt64 */ | |
| 203 }, | |
| 204 0, /* pFileList */ | |
| 205 0 /* pParent */ | |
| 206 }; | |
| 207 | |
| 208 static sqlite3_io_methods fs_io_methods = { | |
| 209 1, /* iVersion */ | |
| 210 fsClose, /* xClose */ | |
| 211 fsRead, /* xRead */ | |
| 212 fsWrite, /* xWrite */ | |
| 213 fsTruncate, /* xTruncate */ | |
| 214 fsSync, /* xSync */ | |
| 215 fsFileSize, /* xFileSize */ | |
| 216 fsLock, /* xLock */ | |
| 217 fsUnlock, /* xUnlock */ | |
| 218 fsCheckReservedLock, /* xCheckReservedLock */ | |
| 219 fsFileControl, /* xFileControl */ | |
| 220 fsSectorSize, /* xSectorSize */ | |
| 221 fsDeviceCharacteristics, /* xDeviceCharacteristics */ | |
| 222 0, /* xShmMap */ | |
| 223 0, /* xShmLock */ | |
| 224 0, /* xShmBarrier */ | |
| 225 0 /* xShmUnmap */ | |
| 226 }; | |
| 227 | |
| 228 | |
| 229 static sqlite3_io_methods tmp_io_methods = { | |
| 230 1, /* iVersion */ | |
| 231 tmpClose, /* xClose */ | |
| 232 tmpRead, /* xRead */ | |
| 233 tmpWrite, /* xWrite */ | |
| 234 tmpTruncate, /* xTruncate */ | |
| 235 tmpSync, /* xSync */ | |
| 236 tmpFileSize, /* xFileSize */ | |
| 237 tmpLock, /* xLock */ | |
| 238 tmpUnlock, /* xUnlock */ | |
| 239 tmpCheckReservedLock, /* xCheckReservedLock */ | |
| 240 tmpFileControl, /* xFileControl */ | |
| 241 tmpSectorSize, /* xSectorSize */ | |
| 242 tmpDeviceCharacteristics, /* xDeviceCharacteristics */ | |
| 243 0, /* xShmMap */ | |
| 244 0, /* xShmLock */ | |
| 245 0, /* xShmBarrier */ | |
| 246 0 /* xShmUnmap */ | |
| 247 }; | |
| 248 | |
| 249 /* Useful macros used in several places */ | |
| 250 #define MIN(x,y) ((x)<(y)?(x):(y)) | |
| 251 #define MAX(x,y) ((x)>(y)?(x):(y)) | |
| 252 | |
| 253 | |
| 254 /* | |
| 255 ** Close a tmp-file. | |
| 256 */ | |
| 257 static int tmpClose(sqlite3_file *pFile){ | |
| 258 tmp_file *pTmp = (tmp_file *)pFile; | |
| 259 sqlite3_free(pTmp->zAlloc); | |
| 260 return SQLITE_OK; | |
| 261 } | |
| 262 | |
| 263 /* | |
| 264 ** Read data from a tmp-file. | |
| 265 */ | |
| 266 static int tmpRead( | |
| 267 sqlite3_file *pFile, | |
| 268 void *zBuf, | |
| 269 int iAmt, | |
| 270 sqlite_int64 iOfst | |
| 271 ){ | |
| 272 tmp_file *pTmp = (tmp_file *)pFile; | |
| 273 if( (iAmt+iOfst)>pTmp->nSize ){ | |
| 274 return SQLITE_IOERR_SHORT_READ; | |
| 275 } | |
| 276 memcpy(zBuf, &pTmp->zAlloc[iOfst], iAmt); | |
| 277 return SQLITE_OK; | |
| 278 } | |
| 279 | |
| 280 /* | |
| 281 ** Write data to a tmp-file. | |
| 282 */ | |
| 283 static int tmpWrite( | |
| 284 sqlite3_file *pFile, | |
| 285 const void *zBuf, | |
| 286 int iAmt, | |
| 287 sqlite_int64 iOfst | |
| 288 ){ | |
| 289 tmp_file *pTmp = (tmp_file *)pFile; | |
| 290 if( (iAmt+iOfst)>pTmp->nAlloc ){ | |
| 291 int nNew = (int)(2*(iAmt+iOfst+pTmp->nAlloc)); | |
| 292 char *zNew = sqlite3_realloc(pTmp->zAlloc, nNew); | |
| 293 if( !zNew ){ | |
| 294 return SQLITE_NOMEM; | |
| 295 } | |
| 296 pTmp->zAlloc = zNew; | |
| 297 pTmp->nAlloc = nNew; | |
| 298 } | |
| 299 memcpy(&pTmp->zAlloc[iOfst], zBuf, iAmt); | |
| 300 pTmp->nSize = (int)MAX(pTmp->nSize, iOfst+iAmt); | |
| 301 return SQLITE_OK; | |
| 302 } | |
| 303 | |
| 304 /* | |
| 305 ** Truncate a tmp-file. | |
| 306 */ | |
| 307 static int tmpTruncate(sqlite3_file *pFile, sqlite_int64 size){ | |
| 308 tmp_file *pTmp = (tmp_file *)pFile; | |
| 309 pTmp->nSize = (int)MIN(pTmp->nSize, size); | |
| 310 return SQLITE_OK; | |
| 311 } | |
| 312 | |
| 313 /* | |
| 314 ** Sync a tmp-file. | |
| 315 */ | |
| 316 static int tmpSync(sqlite3_file *pFile, int flags){ | |
| 317 return SQLITE_OK; | |
| 318 } | |
| 319 | |
| 320 /* | |
| 321 ** Return the current file-size of a tmp-file. | |
| 322 */ | |
| 323 static int tmpFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){ | |
| 324 tmp_file *pTmp = (tmp_file *)pFile; | |
| 325 *pSize = pTmp->nSize; | |
| 326 return SQLITE_OK; | |
| 327 } | |
| 328 | |
| 329 /* | |
| 330 ** Lock a tmp-file. | |
| 331 */ | |
| 332 static int tmpLock(sqlite3_file *pFile, int eLock){ | |
| 333 return SQLITE_OK; | |
| 334 } | |
| 335 | |
| 336 /* | |
| 337 ** Unlock a tmp-file. | |
| 338 */ | |
| 339 static int tmpUnlock(sqlite3_file *pFile, int eLock){ | |
| 340 return SQLITE_OK; | |
| 341 } | |
| 342 | |
| 343 /* | |
| 344 ** Check if another file-handle holds a RESERVED lock on a tmp-file. | |
| 345 */ | |
| 346 static int tmpCheckReservedLock(sqlite3_file *pFile, int *pResOut){ | |
| 347 *pResOut = 0; | |
| 348 return SQLITE_OK; | |
| 349 } | |
| 350 | |
| 351 /* | |
| 352 ** File control method. For custom operations on a tmp-file. | |
| 353 */ | |
| 354 static int tmpFileControl(sqlite3_file *pFile, int op, void *pArg){ | |
| 355 return SQLITE_OK; | |
| 356 } | |
| 357 | |
| 358 /* | |
| 359 ** Return the sector-size in bytes for a tmp-file. | |
| 360 */ | |
| 361 static int tmpSectorSize(sqlite3_file *pFile){ | |
| 362 return 0; | |
| 363 } | |
| 364 | |
| 365 /* | |
| 366 ** Return the device characteristic flags supported by a tmp-file. | |
| 367 */ | |
| 368 static int tmpDeviceCharacteristics(sqlite3_file *pFile){ | |
| 369 return 0; | |
| 370 } | |
| 371 | |
| 372 /* | |
| 373 ** Close an fs-file. | |
| 374 */ | |
| 375 static int fsClose(sqlite3_file *pFile){ | |
| 376 int rc = SQLITE_OK; | |
| 377 fs_file *p = (fs_file *)pFile; | |
| 378 fs_real_file *pReal = p->pReal; | |
| 379 | |
| 380 /* Decrement the real_file ref-count. */ | |
| 381 pReal->nRef--; | |
| 382 assert(pReal->nRef>=0); | |
| 383 | |
| 384 /* When the ref-count reaches 0, destroy the structure */ | |
| 385 if( pReal->nRef==0 ){ | |
| 386 *pReal->ppThis = pReal->pNext; | |
| 387 if( pReal->pNext ){ | |
| 388 pReal->pNext->ppThis = pReal->ppThis; | |
| 389 } | |
| 390 rc = pReal->pFile->pMethods->xClose(pReal->pFile); | |
| 391 sqlite3_free(pReal); | |
| 392 } | |
| 393 | |
| 394 return rc; | |
| 395 } | |
| 396 | |
| 397 /* | |
| 398 ** Read data from an fs-file. | |
| 399 */ | |
| 400 static int fsRead( | |
| 401 sqlite3_file *pFile, | |
| 402 void *zBuf, | |
| 403 int iAmt, | |
| 404 sqlite_int64 iOfst | |
| 405 ){ | |
| 406 int rc = SQLITE_OK; | |
| 407 fs_file *p = (fs_file *)pFile; | |
| 408 fs_real_file *pReal = p->pReal; | |
| 409 sqlite3_file *pF = pReal->pFile; | |
| 410 | |
| 411 if( (p->eType==DATABASE_FILE && (iAmt+iOfst)>pReal->nDatabase) | |
| 412 || (p->eType==JOURNAL_FILE && (iAmt+iOfst)>pReal->nJournal) | |
| 413 ){ | |
| 414 rc = SQLITE_IOERR_SHORT_READ; | |
| 415 }else if( p->eType==DATABASE_FILE ){ | |
| 416 rc = pF->pMethods->xRead(pF, zBuf, iAmt, iOfst+BLOCKSIZE); | |
| 417 }else{ | |
| 418 /* Journal file. */ | |
| 419 int iRem = iAmt; | |
| 420 int iBuf = 0; | |
| 421 int ii = (int)iOfst; | |
| 422 while( iRem>0 && rc==SQLITE_OK ){ | |
| 423 int iRealOff = pReal->nBlob - BLOCKSIZE*((ii/BLOCKSIZE)+1) + ii%BLOCKSIZE; | |
| 424 int iRealAmt = MIN(iRem, BLOCKSIZE - (iRealOff%BLOCKSIZE)); | |
| 425 | |
| 426 rc = pF->pMethods->xRead(pF, &((char *)zBuf)[iBuf], iRealAmt, iRealOff); | |
| 427 ii += iRealAmt; | |
| 428 iBuf += iRealAmt; | |
| 429 iRem -= iRealAmt; | |
| 430 } | |
| 431 } | |
| 432 | |
| 433 return rc; | |
| 434 } | |
| 435 | |
| 436 /* | |
| 437 ** Write data to an fs-file. | |
| 438 */ | |
| 439 static int fsWrite( | |
| 440 sqlite3_file *pFile, | |
| 441 const void *zBuf, | |
| 442 int iAmt, | |
| 443 sqlite_int64 iOfst | |
| 444 ){ | |
| 445 int rc = SQLITE_OK; | |
| 446 fs_file *p = (fs_file *)pFile; | |
| 447 fs_real_file *pReal = p->pReal; | |
| 448 sqlite3_file *pF = pReal->pFile; | |
| 449 | |
| 450 if( p->eType==DATABASE_FILE ){ | |
| 451 if( (iAmt+iOfst+BLOCKSIZE)>(pReal->nBlob-pReal->nJournal) ){ | |
| 452 rc = SQLITE_FULL; | |
| 453 }else{ | |
| 454 rc = pF->pMethods->xWrite(pF, zBuf, iAmt, iOfst+BLOCKSIZE); | |
| 455 if( rc==SQLITE_OK ){ | |
| 456 pReal->nDatabase = (int)MAX(pReal->nDatabase, iAmt+iOfst); | |
| 457 } | |
| 458 } | |
| 459 }else{ | |
| 460 /* Journal file. */ | |
| 461 int iRem = iAmt; | |
| 462 int iBuf = 0; | |
| 463 int ii = (int)iOfst; | |
| 464 while( iRem>0 && rc==SQLITE_OK ){ | |
| 465 int iRealOff = pReal->nBlob - BLOCKSIZE*((ii/BLOCKSIZE)+1) + ii%BLOCKSIZE; | |
| 466 int iRealAmt = MIN(iRem, BLOCKSIZE - (iRealOff%BLOCKSIZE)); | |
| 467 | |
| 468 if( iRealOff<(pReal->nDatabase+BLOCKSIZE) ){ | |
| 469 rc = SQLITE_FULL; | |
| 470 }else{ | |
| 471 rc = pF->pMethods->xWrite(pF, &((char *)zBuf)[iBuf], iRealAmt,iRealOff); | |
| 472 ii += iRealAmt; | |
| 473 iBuf += iRealAmt; | |
| 474 iRem -= iRealAmt; | |
| 475 } | |
| 476 } | |
| 477 if( rc==SQLITE_OK ){ | |
| 478 pReal->nJournal = (int)MAX(pReal->nJournal, iAmt+iOfst); | |
| 479 } | |
| 480 } | |
| 481 | |
| 482 return rc; | |
| 483 } | |
| 484 | |
| 485 /* | |
| 486 ** Truncate an fs-file. | |
| 487 */ | |
| 488 static int fsTruncate(sqlite3_file *pFile, sqlite_int64 size){ | |
| 489 fs_file *p = (fs_file *)pFile; | |
| 490 fs_real_file *pReal = p->pReal; | |
| 491 if( p->eType==DATABASE_FILE ){ | |
| 492 pReal->nDatabase = (int)MIN(pReal->nDatabase, size); | |
| 493 }else{ | |
| 494 pReal->nJournal = (int)MIN(pReal->nJournal, size); | |
| 495 } | |
| 496 return SQLITE_OK; | |
| 497 } | |
| 498 | |
| 499 /* | |
| 500 ** Sync an fs-file. | |
| 501 */ | |
| 502 static int fsSync(sqlite3_file *pFile, int flags){ | |
| 503 fs_file *p = (fs_file *)pFile; | |
| 504 fs_real_file *pReal = p->pReal; | |
| 505 sqlite3_file *pRealFile = pReal->pFile; | |
| 506 int rc = SQLITE_OK; | |
| 507 | |
| 508 if( p->eType==DATABASE_FILE ){ | |
| 509 unsigned char zSize[4]; | |
| 510 zSize[0] = (pReal->nDatabase&0xFF000000)>>24; | |
| 511 zSize[1] = (pReal->nDatabase&0x00FF0000)>>16; | |
| 512 zSize[2] = (pReal->nDatabase&0x0000FF00)>>8; | |
| 513 zSize[3] = (pReal->nDatabase&0x000000FF); | |
| 514 rc = pRealFile->pMethods->xWrite(pRealFile, zSize, 4, 0); | |
| 515 } | |
| 516 if( rc==SQLITE_OK ){ | |
| 517 rc = pRealFile->pMethods->xSync(pRealFile, flags&(~SQLITE_SYNC_DATAONLY)); | |
| 518 } | |
| 519 | |
| 520 return rc; | |
| 521 } | |
| 522 | |
| 523 /* | |
| 524 ** Return the current file-size of an fs-file. | |
| 525 */ | |
| 526 static int fsFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){ | |
| 527 fs_file *p = (fs_file *)pFile; | |
| 528 fs_real_file *pReal = p->pReal; | |
| 529 if( p->eType==DATABASE_FILE ){ | |
| 530 *pSize = pReal->nDatabase; | |
| 531 }else{ | |
| 532 *pSize = pReal->nJournal; | |
| 533 } | |
| 534 return SQLITE_OK; | |
| 535 } | |
| 536 | |
| 537 /* | |
| 538 ** Lock an fs-file. | |
| 539 */ | |
| 540 static int fsLock(sqlite3_file *pFile, int eLock){ | |
| 541 return SQLITE_OK; | |
| 542 } | |
| 543 | |
| 544 /* | |
| 545 ** Unlock an fs-file. | |
| 546 */ | |
| 547 static int fsUnlock(sqlite3_file *pFile, int eLock){ | |
| 548 return SQLITE_OK; | |
| 549 } | |
| 550 | |
| 551 /* | |
| 552 ** Check if another file-handle holds a RESERVED lock on an fs-file. | |
| 553 */ | |
| 554 static int fsCheckReservedLock(sqlite3_file *pFile, int *pResOut){ | |
| 555 *pResOut = 0; | |
| 556 return SQLITE_OK; | |
| 557 } | |
| 558 | |
| 559 /* | |
| 560 ** File control method. For custom operations on an fs-file. | |
| 561 */ | |
| 562 static int fsFileControl(sqlite3_file *pFile, int op, void *pArg){ | |
| 563 return SQLITE_OK; | |
| 564 } | |
| 565 | |
| 566 /* | |
| 567 ** Return the sector-size in bytes for an fs-file. | |
| 568 */ | |
| 569 static int fsSectorSize(sqlite3_file *pFile){ | |
| 570 return BLOCKSIZE; | |
| 571 } | |
| 572 | |
| 573 /* | |
| 574 ** Return the device characteristic flags supported by an fs-file. | |
| 575 */ | |
| 576 static int fsDeviceCharacteristics(sqlite3_file *pFile){ | |
| 577 return 0; | |
| 578 } | |
| 579 | |
| 580 /* | |
| 581 ** Open an fs file handle. | |
| 582 */ | |
| 583 static int fsOpen( | |
| 584 sqlite3_vfs *pVfs, | |
| 585 const char *zName, | |
| 586 sqlite3_file *pFile, | |
| 587 int flags, | |
| 588 int *pOutFlags | |
| 589 ){ | |
| 590 fs_vfs_t *pFsVfs = (fs_vfs_t *)pVfs; | |
| 591 fs_file *p = (fs_file *)pFile; | |
| 592 fs_real_file *pReal = 0; | |
| 593 int eType; | |
| 594 int nName; | |
| 595 int rc = SQLITE_OK; | |
| 596 | |
| 597 if( 0==(flags&(SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_MAIN_JOURNAL)) ){ | |
| 598 tmp_file *p2 = (tmp_file *)pFile; | |
| 599 memset(p2, 0, sizeof(*p2)); | |
| 600 p2->base.pMethods = &tmp_io_methods; | |
| 601 return SQLITE_OK; | |
| 602 } | |
| 603 | |
| 604 eType = ((flags&(SQLITE_OPEN_MAIN_DB))?DATABASE_FILE:JOURNAL_FILE); | |
| 605 p->base.pMethods = &fs_io_methods; | |
| 606 p->eType = eType; | |
| 607 | |
| 608 assert(strlen("-journal")==8); | |
| 609 nName = (int)strlen(zName)-((eType==JOURNAL_FILE)?8:0); | |
| 610 pReal=pFsVfs->pFileList; | |
| 611 for(; pReal && strncmp(pReal->zName, zName, nName); pReal=pReal->pNext); | |
| 612 | |
| 613 if( !pReal ){ | |
| 614 int real_flags = (flags&~(SQLITE_OPEN_MAIN_DB))|SQLITE_OPEN_TEMP_DB; | |
| 615 sqlite3_int64 size; | |
| 616 sqlite3_file *pRealFile; | |
| 617 sqlite3_vfs *pParent = pFsVfs->pParent; | |
| 618 assert(eType==DATABASE_FILE); | |
| 619 | |
| 620 pReal = (fs_real_file *)sqlite3_malloc(sizeof(*pReal)+pParent->szOsFile); | |
| 621 if( !pReal ){ | |
| 622 rc = SQLITE_NOMEM; | |
| 623 goto open_out; | |
| 624 } | |
| 625 memset(pReal, 0, sizeof(*pReal)+pParent->szOsFile); | |
| 626 pReal->zName = zName; | |
| 627 pReal->pFile = (sqlite3_file *)(&pReal[1]); | |
| 628 | |
| 629 rc = pParent->xOpen(pParent, zName, pReal->pFile, real_flags, pOutFlags); | |
| 630 if( rc!=SQLITE_OK ){ | |
| 631 goto open_out; | |
| 632 } | |
| 633 pRealFile = pReal->pFile; | |
| 634 | |
| 635 rc = pRealFile->pMethods->xFileSize(pRealFile, &size); | |
| 636 if( rc!=SQLITE_OK ){ | |
| 637 goto open_out; | |
| 638 } | |
| 639 if( size==0 ){ | |
| 640 rc = pRealFile->pMethods->xWrite(pRealFile, "\0", 1, BLOBSIZE-1); | |
| 641 pReal->nBlob = BLOBSIZE; | |
| 642 }else{ | |
| 643 unsigned char zS[4]; | |
| 644 pReal->nBlob = (int)size; | |
| 645 rc = pRealFile->pMethods->xRead(pRealFile, zS, 4, 0); | |
| 646 pReal->nDatabase = (zS[0]<<24)+(zS[1]<<16)+(zS[2]<<8)+zS[3]; | |
| 647 if( rc==SQLITE_OK ){ | |
| 648 rc = pRealFile->pMethods->xRead(pRealFile, zS, 4, pReal->nBlob-4); | |
| 649 if( zS[0] || zS[1] || zS[2] || zS[3] ){ | |
| 650 pReal->nJournal = pReal->nBlob; | |
| 651 } | |
| 652 } | |
| 653 } | |
| 654 | |
| 655 if( rc==SQLITE_OK ){ | |
| 656 pReal->pNext = pFsVfs->pFileList; | |
| 657 if( pReal->pNext ){ | |
| 658 pReal->pNext->ppThis = &pReal->pNext; | |
| 659 } | |
| 660 pReal->ppThis = &pFsVfs->pFileList; | |
| 661 pFsVfs->pFileList = pReal; | |
| 662 } | |
| 663 } | |
| 664 | |
| 665 open_out: | |
| 666 if( pReal ){ | |
| 667 if( rc==SQLITE_OK ){ | |
| 668 p->pReal = pReal; | |
| 669 pReal->nRef++; | |
| 670 }else{ | |
| 671 if( pReal->pFile->pMethods ){ | |
| 672 pReal->pFile->pMethods->xClose(pReal->pFile); | |
| 673 } | |
| 674 sqlite3_free(pReal); | |
| 675 } | |
| 676 } | |
| 677 return rc; | |
| 678 } | |
| 679 | |
| 680 /* | |
| 681 ** Delete the file located at zPath. If the dirSync argument is true, | |
| 682 ** ensure the file-system modifications are synced to disk before | |
| 683 ** returning. | |
| 684 */ | |
| 685 static int fsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){ | |
| 686 int rc = SQLITE_OK; | |
| 687 fs_vfs_t *pFsVfs = (fs_vfs_t *)pVfs; | |
| 688 fs_real_file *pReal; | |
| 689 sqlite3_file *pF; | |
| 690 int nName = (int)strlen(zPath) - 8; | |
| 691 | |
| 692 assert(strlen("-journal")==8); | |
| 693 assert(strcmp("-journal", &zPath[nName])==0); | |
| 694 | |
| 695 pReal = pFsVfs->pFileList; | |
| 696 for(; pReal && strncmp(pReal->zName, zPath, nName); pReal=pReal->pNext); | |
| 697 if( pReal ){ | |
| 698 pF = pReal->pFile; | |
| 699 rc = pF->pMethods->xWrite(pF, "\0\0\0\0", 4, pReal->nBlob-BLOCKSIZE); | |
| 700 if( rc==SQLITE_OK ){ | |
| 701 pReal->nJournal = 0; | |
| 702 } | |
| 703 } | |
| 704 return rc; | |
| 705 } | |
| 706 | |
| 707 /* | |
| 708 ** Test for access permissions. Return true if the requested permission | |
| 709 ** is available, or false otherwise. | |
| 710 */ | |
| 711 static int fsAccess( | |
| 712 sqlite3_vfs *pVfs, | |
| 713 const char *zPath, | |
| 714 int flags, | |
| 715 int *pResOut | |
| 716 ){ | |
| 717 fs_vfs_t *pFsVfs = (fs_vfs_t *)pVfs; | |
| 718 fs_real_file *pReal; | |
| 719 int isJournal = 0; | |
| 720 int nName = (int)strlen(zPath); | |
| 721 | |
| 722 if( flags!=SQLITE_ACCESS_EXISTS ){ | |
| 723 sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent; | |
| 724 return pParent->xAccess(pParent, zPath, flags, pResOut); | |
| 725 } | |
| 726 | |
| 727 assert(strlen("-journal")==8); | |
| 728 if( nName>8 && strcmp("-journal", &zPath[nName-8])==0 ){ | |
| 729 nName -= 8; | |
| 730 isJournal = 1; | |
| 731 } | |
| 732 | |
| 733 pReal = pFsVfs->pFileList; | |
| 734 for(; pReal && strncmp(pReal->zName, zPath, nName); pReal=pReal->pNext); | |
| 735 | |
| 736 *pResOut = (pReal && (!isJournal || pReal->nJournal>0)); | |
| 737 return SQLITE_OK; | |
| 738 } | |
| 739 | |
| 740 /* | |
| 741 ** Populate buffer zOut with the full canonical pathname corresponding | |
| 742 ** to the pathname in zPath. zOut is guaranteed to point to a buffer | |
| 743 ** of at least (FS_MAX_PATHNAME+1) bytes. | |
| 744 */ | |
| 745 static int fsFullPathname( | |
| 746 sqlite3_vfs *pVfs, /* Pointer to vfs object */ | |
| 747 const char *zPath, /* Possibly relative input path */ | |
| 748 int nOut, /* Size of output buffer in bytes */ | |
| 749 char *zOut /* Output buffer */ | |
| 750 ){ | |
| 751 sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent; | |
| 752 return pParent->xFullPathname(pParent, zPath, nOut, zOut); | |
| 753 } | |
| 754 | |
| 755 /* | |
| 756 ** Open the dynamic library located at zPath and return a handle. | |
| 757 */ | |
| 758 static void *fsDlOpen(sqlite3_vfs *pVfs, const char *zPath){ | |
| 759 sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent; | |
| 760 return pParent->xDlOpen(pParent, zPath); | |
| 761 } | |
| 762 | |
| 763 /* | |
| 764 ** Populate the buffer zErrMsg (size nByte bytes) with a human readable | |
| 765 ** utf-8 string describing the most recent error encountered associated | |
| 766 ** with dynamic libraries. | |
| 767 */ | |
| 768 static void fsDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){ | |
| 769 sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent; | |
| 770 pParent->xDlError(pParent, nByte, zErrMsg); | |
| 771 } | |
| 772 | |
| 773 /* | |
| 774 ** Return a pointer to the symbol zSymbol in the dynamic library pHandle. | |
| 775 */ | |
| 776 static void (*fsDlSym(sqlite3_vfs *pVfs, void *pH, const char *zSym))(void){ | |
| 777 sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent; | |
| 778 return pParent->xDlSym(pParent, pH, zSym); | |
| 779 } | |
| 780 | |
| 781 /* | |
| 782 ** Close the dynamic library handle pHandle. | |
| 783 */ | |
| 784 static void fsDlClose(sqlite3_vfs *pVfs, void *pHandle){ | |
| 785 sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent; | |
| 786 pParent->xDlClose(pParent, pHandle); | |
| 787 } | |
| 788 | |
| 789 /* | |
| 790 ** Populate the buffer pointed to by zBufOut with nByte bytes of | |
| 791 ** random data. | |
| 792 */ | |
| 793 static int fsRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){ | |
| 794 sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent; | |
| 795 return pParent->xRandomness(pParent, nByte, zBufOut); | |
| 796 } | |
| 797 | |
| 798 /* | |
| 799 ** Sleep for nMicro microseconds. Return the number of microseconds | |
| 800 ** actually slept. | |
| 801 */ | |
| 802 static int fsSleep(sqlite3_vfs *pVfs, int nMicro){ | |
| 803 sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent; | |
| 804 return pParent->xSleep(pParent, nMicro); | |
| 805 } | |
| 806 | |
| 807 /* | |
| 808 ** Return the current time as a Julian Day number in *pTimeOut. | |
| 809 */ | |
| 810 static int fsCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){ | |
| 811 sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent; | |
| 812 return pParent->xCurrentTime(pParent, pTimeOut); | |
| 813 } | |
| 814 | |
| 815 /* | |
| 816 ** This procedure registers the fs vfs with SQLite. If the argument is | |
| 817 ** true, the fs vfs becomes the new default vfs. It is the only publicly | |
| 818 ** available function in this file. | |
| 819 */ | |
| 820 int fs_register(void){ | |
| 821 if( fs_vfs.pParent ) return SQLITE_OK; | |
| 822 fs_vfs.pParent = sqlite3_vfs_find(0); | |
| 823 fs_vfs.base.mxPathname = fs_vfs.pParent->mxPathname; | |
| 824 fs_vfs.base.szOsFile = MAX(sizeof(tmp_file), sizeof(fs_file)); | |
| 825 return sqlite3_vfs_register(&fs_vfs.base, 0); | |
| 826 } | |
| 827 | |
| 828 #ifdef SQLITE_TEST | |
| 829 int SqlitetestOnefile_Init() {return fs_register();} | |
| 830 #endif | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 2846743003:
[sql] Remove SQLite 3.10.2 reference directory. (Closed)
