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| 1 /* | |
| 2 ** 2008 Jan 22 | |
| 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 ** This file contains code for a VFS layer that acts as a wrapper around | |
| 14 ** an existing VFS. The code in this file attempts to verify that SQLite | |
| 15 ** correctly populates and syncs a journal file before writing to a | |
| 16 ** corresponding database file. | |
| 17 ** | |
| 18 ** $Id: test_journal.c,v 1.17 2009/06/26 10:39:36 danielk1977 Exp $ | |
| 19 */ | |
| 20 #if SQLITE_TEST /* This file is used for testing only */ | |
| 21 | |
| 22 #include "sqlite3.h" | |
| 23 #include "sqliteInt.h" | |
| 24 | |
| 25 /* | |
| 26 ** INTERFACE | |
| 27 ** | |
| 28 ** The public interface to this wrapper VFS is two functions: | |
| 29 ** | |
| 30 ** jt_register() | |
| 31 ** jt_unregister() | |
| 32 ** | |
| 33 ** See header comments associated with those two functions below for | |
| 34 ** details. | |
| 35 ** | |
| 36 ** LIMITATIONS | |
| 37 ** | |
| 38 ** This wrapper will not work if "PRAGMA synchronous = off" is used. | |
| 39 ** | |
| 40 ** OPERATION | |
| 41 ** | |
| 42 ** Starting a Transaction: | |
| 43 ** | |
| 44 ** When a write-transaction is started, the contents of the database is | |
| 45 ** inspected and the following data stored as part of the database file | |
| 46 ** handle (type struct jt_file): | |
| 47 ** | |
| 48 ** a) The page-size of the database file. | |
| 49 ** b) The number of pages that are in the database file. | |
| 50 ** c) The set of page numbers corresponding to free-list leaf pages. | |
| 51 ** d) A check-sum for every page in the database file. | |
| 52 ** | |
| 53 ** The start of a write-transaction is deemed to have occurred when a | |
| 54 ** 28-byte journal header is written to byte offset 0 of the journal | |
| 55 ** file. | |
| 56 ** | |
| 57 ** Syncing the Journal File: | |
| 58 ** | |
| 59 ** Whenever the xSync method is invoked to sync a journal-file, the | |
| 60 ** contents of the journal file are read. For each page written to | |
| 61 ** the journal file, a check-sum is calculated and compared to the | |
| 62 ** check-sum calculated for the corresponding database page when the | |
| 63 ** write-transaction was initialized. The success of the comparison | |
| 64 ** is assert()ed. So if SQLite has written something other than the | |
| 65 ** original content to the database file, an assert() will fail. | |
| 66 ** | |
| 67 ** Additionally, the set of page numbers for which records exist in | |
| 68 ** the journal file is added to (unioned with) the set of page numbers | |
| 69 ** corresponding to free-list leaf pages collected when the | |
| 70 ** write-transaction was initialized. This set comprises the page-numbers | |
| 71 ** corresponding to those pages that SQLite may now safely modify. | |
| 72 ** | |
| 73 ** Writing to the Database File: | |
| 74 ** | |
| 75 ** When a block of data is written to a database file, the following | |
| 76 ** invariants are asserted: | |
| 77 ** | |
| 78 ** a) That the block of data is an aligned block of page-size bytes. | |
| 79 ** | |
| 80 ** b) That if the page being written did not exist when the | |
| 81 ** transaction was started (i.e. the database file is growing), then | |
| 82 ** the journal-file must have been synced at least once since | |
| 83 ** the start of the transaction. | |
| 84 ** | |
| 85 ** c) That if the page being written did exist when the transaction | |
| 86 ** was started, then the page must have either been a free-list | |
| 87 ** leaf page at the start of the transaction, or else must have | |
| 88 ** been stored in the journal file prior to the most recent sync. | |
| 89 ** | |
| 90 ** Closing a Transaction: | |
| 91 ** | |
| 92 ** When a transaction is closed, all data collected at the start of | |
| 93 ** the transaction, or following an xSync of a journal-file, is | |
| 94 ** discarded. The end of a transaction is recognized when any one | |
| 95 ** of the following occur: | |
| 96 ** | |
| 97 ** a) A block of zeroes (or anything else that is not a valid | |
| 98 ** journal-header) is written to the start of the journal file. | |
| 99 ** | |
| 100 ** b) A journal file is truncated to zero bytes in size using xTruncate. | |
| 101 ** | |
| 102 ** c) The journal file is deleted using xDelete. | |
| 103 */ | |
| 104 | |
| 105 /* | |
| 106 ** Maximum pathname length supported by the jt backend. | |
| 107 */ | |
| 108 #define JT_MAX_PATHNAME 512 | |
| 109 | |
| 110 /* | |
| 111 ** Name used to identify this VFS. | |
| 112 */ | |
| 113 #define JT_VFS_NAME "jt" | |
| 114 | |
| 115 typedef struct jt_file jt_file; | |
| 116 struct jt_file { | |
| 117 sqlite3_file base; | |
| 118 const char *zName; /* Name of open file */ | |
| 119 int flags; /* Flags the file was opened with */ | |
| 120 | |
| 121 /* The following are only used by database file file handles */ | |
| 122 int eLock; /* Current lock held on the file */ | |
| 123 u32 nPage; /* Size of file in pages when transaction started */ | |
| 124 u32 nPagesize; /* Page size when transaction started */ | |
| 125 Bitvec *pWritable; /* Bitvec of pages that may be written to the file */ | |
| 126 u32 *aCksum; /* Checksum for first nPage pages */ | |
| 127 int nSync; /* Number of times journal file has been synced */ | |
| 128 | |
| 129 /* Only used by journal file-handles */ | |
| 130 sqlite3_int64 iMaxOff; /* Maximum offset written to this transaction */ | |
| 131 | |
| 132 jt_file *pNext; /* All files are stored in a linked list */ | |
| 133 sqlite3_file *pReal; /* The file handle for the underlying vfs */ | |
| 134 }; | |
| 135 | |
| 136 /* | |
| 137 ** Method declarations for jt_file. | |
| 138 */ | |
| 139 static int jtClose(sqlite3_file*); | |
| 140 static int jtRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); | |
| 141 static int jtWrite(sqlite3_file*,const void*,int iAmt, sqlite3_int64 iOfst); | |
| 142 static int jtTruncate(sqlite3_file*, sqlite3_int64 size); | |
| 143 static int jtSync(sqlite3_file*, int flags); | |
| 144 static int jtFileSize(sqlite3_file*, sqlite3_int64 *pSize); | |
| 145 static int jtLock(sqlite3_file*, int); | |
| 146 static int jtUnlock(sqlite3_file*, int); | |
| 147 static int jtCheckReservedLock(sqlite3_file*, int *); | |
| 148 static int jtFileControl(sqlite3_file*, int op, void *pArg); | |
| 149 static int jtSectorSize(sqlite3_file*); | |
| 150 static int jtDeviceCharacteristics(sqlite3_file*); | |
| 151 | |
| 152 /* | |
| 153 ** Method declarations for jt_vfs. | |
| 154 */ | |
| 155 static int jtOpen(sqlite3_vfs*, const char *, sqlite3_file*, int , int *); | |
| 156 static int jtDelete(sqlite3_vfs*, const char *zName, int syncDir); | |
| 157 static int jtAccess(sqlite3_vfs*, const char *zName, int flags, int *); | |
| 158 static int jtFullPathname(sqlite3_vfs*, const char *zName, int, char *zOut); | |
| 159 static void *jtDlOpen(sqlite3_vfs*, const char *zFilename); | |
| 160 static void jtDlError(sqlite3_vfs*, int nByte, char *zErrMsg); | |
| 161 static void (*jtDlSym(sqlite3_vfs*,void*, const char *zSymbol))(void); | |
| 162 static void jtDlClose(sqlite3_vfs*, void*); | |
| 163 static int jtRandomness(sqlite3_vfs*, int nByte, char *zOut); | |
| 164 static int jtSleep(sqlite3_vfs*, int microseconds); | |
| 165 static int jtCurrentTime(sqlite3_vfs*, double*); | |
| 166 | |
| 167 static sqlite3_vfs jt_vfs = { | |
| 168 1, /* iVersion */ | |
| 169 sizeof(jt_file), /* szOsFile */ | |
| 170 JT_MAX_PATHNAME, /* mxPathname */ | |
| 171 0, /* pNext */ | |
| 172 JT_VFS_NAME, /* zName */ | |
| 173 0, /* pAppData */ | |
| 174 jtOpen, /* xOpen */ | |
| 175 jtDelete, /* xDelete */ | |
| 176 jtAccess, /* xAccess */ | |
| 177 jtFullPathname, /* xFullPathname */ | |
| 178 jtDlOpen, /* xDlOpen */ | |
| 179 jtDlError, /* xDlError */ | |
| 180 jtDlSym, /* xDlSym */ | |
| 181 jtDlClose, /* xDlClose */ | |
| 182 jtRandomness, /* xRandomness */ | |
| 183 jtSleep, /* xSleep */ | |
| 184 jtCurrentTime /* xCurrentTime */ | |
| 185 }; | |
| 186 | |
| 187 static sqlite3_io_methods jt_io_methods = { | |
| 188 1, /* iVersion */ | |
| 189 jtClose, /* xClose */ | |
| 190 jtRead, /* xRead */ | |
| 191 jtWrite, /* xWrite */ | |
| 192 jtTruncate, /* xTruncate */ | |
| 193 jtSync, /* xSync */ | |
| 194 jtFileSize, /* xFileSize */ | |
| 195 jtLock, /* xLock */ | |
| 196 jtUnlock, /* xUnlock */ | |
| 197 jtCheckReservedLock, /* xCheckReservedLock */ | |
| 198 jtFileControl, /* xFileControl */ | |
| 199 jtSectorSize, /* xSectorSize */ | |
| 200 jtDeviceCharacteristics /* xDeviceCharacteristics */ | |
| 201 }; | |
| 202 | |
| 203 struct JtGlobal { | |
| 204 sqlite3_vfs *pVfs; /* Parent VFS */ | |
| 205 jt_file *pList; /* List of all open files */ | |
| 206 }; | |
| 207 static struct JtGlobal g = {0, 0}; | |
| 208 | |
| 209 /* | |
| 210 ** Functions to obtain and relinquish a mutex to protect g.pList. The | |
| 211 ** STATIC_PRNG mutex is reused, purely for the sake of convenience. | |
| 212 */ | |
| 213 static void enterJtMutex(void){ | |
| 214 sqlite3_mutex_enter(sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_PRNG)); | |
| 215 } | |
| 216 static void leaveJtMutex(void){ | |
| 217 sqlite3_mutex_leave(sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_PRNG)); | |
| 218 } | |
| 219 | |
| 220 extern int sqlite3_io_error_pending; | |
| 221 extern int sqlite3_io_error_hit; | |
| 222 static void stop_ioerr_simulation(int *piSave, int *piSave2){ | |
| 223 *piSave = sqlite3_io_error_pending; | |
| 224 *piSave2 = sqlite3_io_error_hit; | |
| 225 sqlite3_io_error_pending = -1; | |
| 226 sqlite3_io_error_hit = 0; | |
| 227 } | |
| 228 static void start_ioerr_simulation(int iSave, int iSave2){ | |
| 229 sqlite3_io_error_pending = iSave; | |
| 230 sqlite3_io_error_hit = iSave2; | |
| 231 } | |
| 232 | |
| 233 /* | |
| 234 ** The jt_file pointed to by the argument may or may not be a file-handle | |
| 235 ** open on a main database file. If it is, and a transaction is currently | |
| 236 ** opened on the file, then discard all transaction related data. | |
| 237 */ | |
| 238 static void closeTransaction(jt_file *p){ | |
| 239 sqlite3BitvecDestroy(p->pWritable); | |
| 240 sqlite3_free(p->aCksum); | |
| 241 p->pWritable = 0; | |
| 242 p->aCksum = 0; | |
| 243 p->nSync = 0; | |
| 244 } | |
| 245 | |
| 246 /* | |
| 247 ** Close an jt-file. | |
| 248 */ | |
| 249 static int jtClose(sqlite3_file *pFile){ | |
| 250 jt_file **pp; | |
| 251 jt_file *p = (jt_file *)pFile; | |
| 252 | |
| 253 closeTransaction(p); | |
| 254 enterJtMutex(); | |
| 255 if( p->zName ){ | |
| 256 for(pp=&g.pList; *pp!=p; pp=&(*pp)->pNext); | |
| 257 *pp = p->pNext; | |
| 258 } | |
| 259 leaveJtMutex(); | |
| 260 return sqlite3OsClose(p->pReal); | |
| 261 } | |
| 262 | |
| 263 /* | |
| 264 ** Read data from an jt-file. | |
| 265 */ | |
| 266 static int jtRead( | |
| 267 sqlite3_file *pFile, | |
| 268 void *zBuf, | |
| 269 int iAmt, | |
| 270 sqlite_int64 iOfst | |
| 271 ){ | |
| 272 jt_file *p = (jt_file *)pFile; | |
| 273 return sqlite3OsRead(p->pReal, zBuf, iAmt, iOfst); | |
| 274 } | |
| 275 | |
| 276 /* | |
| 277 ** Parameter zJournal is the name of a journal file that is currently | |
| 278 ** open. This function locates and returns the handle opened on the | |
| 279 ** corresponding database file by the pager that currently has the | |
| 280 ** journal file opened. This file-handle is identified by the | |
| 281 ** following properties: | |
| 282 ** | |
| 283 ** a) SQLITE_OPEN_MAIN_DB was specified when the file was opened. | |
| 284 ** | |
| 285 ** b) The file-name specified when the file was opened matches | |
| 286 ** all but the final 8 characters of the journal file name. | |
| 287 ** | |
| 288 ** c) There is currently a reserved lock on the file. | |
| 289 **/ | |
| 290 static jt_file *locateDatabaseHandle(const char *zJournal){ | |
| 291 jt_file *pMain = 0; | |
| 292 enterJtMutex(); | |
| 293 for(pMain=g.pList; pMain; pMain=pMain->pNext){ | |
| 294 int nName = strlen(zJournal) - strlen("-journal"); | |
| 295 if( (pMain->flags&SQLITE_OPEN_MAIN_DB) | |
| 296 && (strlen(pMain->zName)==nName) | |
| 297 && 0==memcmp(pMain->zName, zJournal, nName) | |
| 298 && (pMain->eLock>=SQLITE_LOCK_RESERVED) | |
| 299 ){ | |
| 300 break; | |
| 301 } | |
| 302 } | |
| 303 leaveJtMutex(); | |
| 304 return pMain; | |
| 305 } | |
| 306 | |
| 307 /* | |
| 308 ** Parameter z points to a buffer of 4 bytes in size containing a | |
| 309 ** unsigned 32-bit integer stored in big-endian format. Decode the | |
| 310 ** integer and return its value. | |
| 311 */ | |
| 312 static u32 decodeUint32(const unsigned char *z){ | |
| 313 return (z[0]<<24) + (z[1]<<16) + (z[2]<<8) + z[3]; | |
| 314 } | |
| 315 | |
| 316 /* | |
| 317 ** Calculate a checksum from the buffer of length n bytes pointed to | |
| 318 ** by parameter z. | |
| 319 */ | |
| 320 static u32 genCksum(const unsigned char *z, int n){ | |
| 321 int i; | |
| 322 u32 cksum = 0; | |
| 323 for(i=0; i<n; i++){ | |
| 324 cksum = cksum + z[i] + (cksum<<3); | |
| 325 } | |
| 326 return cksum; | |
| 327 } | |
| 328 | |
| 329 /* | |
| 330 ** The first argument, zBuf, points to a buffer containing a 28 byte | |
| 331 ** serialized journal header. This function deserializes four of the | |
| 332 ** integer fields contained in the journal header and writes their | |
| 333 ** values to the output variables. | |
| 334 ** | |
| 335 ** SQLITE_OK is returned if the journal-header is successfully | |
| 336 ** decoded. Otherwise, SQLITE_ERROR. | |
| 337 */ | |
| 338 static int decodeJournalHdr( | |
| 339 const unsigned char *zBuf, /* Input: 28 byte journal header */ | |
| 340 u32 *pnRec, /* Out: Number of journalled records */ | |
| 341 u32 *pnPage, /* Out: Original database page count */ | |
| 342 u32 *pnSector, /* Out: Sector size in bytes */ | |
| 343 u32 *pnPagesize /* Out: Page size in bytes */ | |
| 344 ){ | |
| 345 unsigned char aMagic[] = { 0xd9, 0xd5, 0x05, 0xf9, 0x20, 0xa1, 0x63, 0xd7 }; | |
| 346 if( memcmp(aMagic, zBuf, 8) ) return SQLITE_ERROR; | |
| 347 if( pnRec ) *pnRec = decodeUint32(&zBuf[8]); | |
| 348 if( pnPage ) *pnPage = decodeUint32(&zBuf[16]); | |
| 349 if( pnSector ) *pnSector = decodeUint32(&zBuf[20]); | |
| 350 if( pnPagesize ) *pnPagesize = decodeUint32(&zBuf[24]); | |
| 351 return SQLITE_OK; | |
| 352 } | |
| 353 | |
| 354 /* | |
| 355 ** This function is called when a new transaction is opened, just after | |
| 356 ** the first journal-header is written to the journal file. | |
| 357 */ | |
| 358 static int openTransaction(jt_file *pMain, jt_file *pJournal){ | |
| 359 unsigned char *aData; | |
| 360 sqlite3_file *p = pMain->pReal; | |
| 361 int rc = SQLITE_OK; | |
| 362 | |
| 363 aData = sqlite3_malloc(pMain->nPagesize); | |
| 364 pMain->pWritable = sqlite3BitvecCreate(pMain->nPage); | |
| 365 pMain->aCksum = sqlite3_malloc(sizeof(u32) * (pMain->nPage + 1)); | |
| 366 pJournal->iMaxOff = 0; | |
| 367 | |
| 368 if( !pMain->pWritable || !pMain->aCksum || !aData ){ | |
| 369 rc = SQLITE_IOERR_NOMEM; | |
| 370 }else if( pMain->nPage>0 ){ | |
| 371 u32 iTrunk; | |
| 372 int iSave; | |
| 373 int iSave2; | |
| 374 | |
| 375 stop_ioerr_simulation(&iSave, &iSave2); | |
| 376 | |
| 377 /* Read the database free-list. Add the page-number for each free-list | |
| 378 ** leaf to the jt_file.pWritable bitvec. | |
| 379 */ | |
| 380 rc = sqlite3OsRead(p, aData, pMain->nPagesize, 0); | |
| 381 iTrunk = decodeUint32(&aData[32]); | |
| 382 while( rc==SQLITE_OK && iTrunk>0 ){ | |
| 383 u32 nLeaf; | |
| 384 u32 iLeaf; | |
| 385 sqlite3_int64 iOff = (iTrunk-1)*pMain->nPagesize; | |
| 386 rc = sqlite3OsRead(p, aData, pMain->nPagesize, iOff); | |
| 387 nLeaf = decodeUint32(&aData[4]); | |
| 388 for(iLeaf=0; rc==SQLITE_OK && iLeaf<nLeaf; iLeaf++){ | |
| 389 u32 pgno = decodeUint32(&aData[8+4*iLeaf]); | |
| 390 sqlite3BitvecSet(pMain->pWritable, pgno); | |
| 391 } | |
| 392 iTrunk = decodeUint32(aData); | |
| 393 } | |
| 394 | |
| 395 /* Calculate and store a checksum for each page in the database file. */ | |
| 396 if( rc==SQLITE_OK ){ | |
| 397 int ii; | |
| 398 for(ii=0; rc==SQLITE_OK && ii<pMain->nPage; ii++){ | |
| 399 i64 iOff = (i64)(pMain->nPagesize) * (i64)ii; | |
| 400 if( iOff==PENDING_BYTE ) continue; | |
| 401 rc = sqlite3OsRead(pMain->pReal, aData, pMain->nPagesize, iOff); | |
| 402 pMain->aCksum[ii] = genCksum(aData, pMain->nPagesize); | |
| 403 } | |
| 404 } | |
| 405 | |
| 406 start_ioerr_simulation(iSave, iSave2); | |
| 407 } | |
| 408 | |
| 409 sqlite3_free(aData); | |
| 410 return rc; | |
| 411 } | |
| 412 | |
| 413 /* | |
| 414 ** The first argument to this function is a handle open on a journal file. | |
| 415 ** This function reads the journal file and adds the page number for each | |
| 416 ** page in the journal to the Bitvec object passed as the second argument. | |
| 417 */ | |
| 418 static int readJournalFile(jt_file *p, jt_file *pMain){ | |
| 419 int rc = SQLITE_OK; | |
| 420 unsigned char zBuf[28]; | |
| 421 sqlite3_file *pReal = p->pReal; | |
| 422 sqlite3_int64 iOff = 0; | |
| 423 sqlite3_int64 iSize = p->iMaxOff; | |
| 424 unsigned char *aPage; | |
| 425 int iSave; | |
| 426 int iSave2; | |
| 427 | |
| 428 aPage = sqlite3_malloc(pMain->nPagesize); | |
| 429 if( !aPage ){ | |
| 430 return SQLITE_IOERR_NOMEM; | |
| 431 } | |
| 432 | |
| 433 stop_ioerr_simulation(&iSave, &iSave2); | |
| 434 | |
| 435 while( rc==SQLITE_OK && iOff<iSize ){ | |
| 436 u32 nRec, nPage, nSector, nPagesize; | |
| 437 u32 ii; | |
| 438 | |
| 439 /* Read and decode the next journal-header from the journal file. */ | |
| 440 rc = sqlite3OsRead(pReal, zBuf, 28, iOff); | |
| 441 if( rc!=SQLITE_OK | |
| 442 || decodeJournalHdr(zBuf, &nRec, &nPage, &nSector, &nPagesize) | |
| 443 ){ | |
| 444 goto finish_rjf; | |
| 445 } | |
| 446 iOff += nSector; | |
| 447 | |
| 448 if( nRec==0 ){ | |
| 449 /* A trick. There might be another journal-header immediately | |
| 450 ** following this one. In this case, 0 records means 0 records, | |
| 451 ** not "read until the end of the file". See also ticket #2565. | |
| 452 */ | |
| 453 if( iSize>=(iOff+nSector) ){ | |
| 454 rc = sqlite3OsRead(pReal, zBuf, 28, iOff); | |
| 455 if( rc!=SQLITE_OK || 0==decodeJournalHdr(zBuf, 0, 0, 0, 0) ){ | |
| 456 continue; | |
| 457 } | |
| 458 } | |
| 459 nRec = (iSize-iOff) / (pMain->nPagesize+8); | |
| 460 } | |
| 461 | |
| 462 /* Read all the records that follow the journal-header just read. */ | |
| 463 for(ii=0; rc==SQLITE_OK && ii<nRec && iOff<iSize; ii++){ | |
| 464 u32 pgno; | |
| 465 rc = sqlite3OsRead(pReal, zBuf, 4, iOff); | |
| 466 if( rc==SQLITE_OK ){ | |
| 467 pgno = decodeUint32(zBuf); | |
| 468 if( pgno>0 && pgno<=pMain->nPage ){ | |
| 469 if( 0==sqlite3BitvecTest(pMain->pWritable, pgno) ){ | |
| 470 rc = sqlite3OsRead(pReal, aPage, pMain->nPagesize, iOff+4); | |
| 471 if( rc==SQLITE_OK ){ | |
| 472 u32 cksum = genCksum(aPage, pMain->nPagesize); | |
| 473 assert( cksum==pMain->aCksum[pgno-1] ); | |
| 474 } | |
| 475 } | |
| 476 sqlite3BitvecSet(pMain->pWritable, pgno); | |
| 477 } | |
| 478 iOff += (8 + pMain->nPagesize); | |
| 479 } | |
| 480 } | |
| 481 | |
| 482 iOff = ((iOff + (nSector-1)) / nSector) * nSector; | |
| 483 } | |
| 484 | |
| 485 finish_rjf: | |
| 486 start_ioerr_simulation(iSave, iSave2); | |
| 487 sqlite3_free(aPage); | |
| 488 if( rc==SQLITE_IOERR_SHORT_READ ){ | |
| 489 rc = SQLITE_OK; | |
| 490 } | |
| 491 return rc; | |
| 492 } | |
| 493 | |
| 494 | |
| 495 /* | |
| 496 ** Write data to an jt-file. | |
| 497 */ | |
| 498 static int jtWrite( | |
| 499 sqlite3_file *pFile, | |
| 500 const void *zBuf, | |
| 501 int iAmt, | |
| 502 sqlite_int64 iOfst | |
| 503 ){ | |
| 504 int rc; | |
| 505 jt_file *p = (jt_file *)pFile; | |
| 506 if( p->flags&SQLITE_OPEN_MAIN_JOURNAL ){ | |
| 507 if( iOfst==0 ){ | |
| 508 jt_file *pMain = locateDatabaseHandle(p->zName); | |
| 509 assert( pMain ); | |
| 510 | |
| 511 if( iAmt==28 ){ | |
| 512 /* Zeroing the first journal-file header. This is the end of a | |
| 513 ** transaction. */ | |
| 514 closeTransaction(pMain); | |
| 515 }else if( iAmt!=12 ){ | |
| 516 /* Writing the first journal header to a journal file. This happens | |
| 517 ** when a transaction is first started. */ | |
| 518 u8 *z = (u8 *)zBuf; | |
| 519 pMain->nPage = decodeUint32(&z[16]); | |
| 520 pMain->nPagesize = decodeUint32(&z[24]); | |
| 521 if( SQLITE_OK!=(rc=openTransaction(pMain, p)) ){ | |
| 522 return rc; | |
| 523 } | |
| 524 } | |
| 525 } | |
| 526 if( p->iMaxOff<(iOfst + iAmt) ){ | |
| 527 p->iMaxOff = iOfst + iAmt; | |
| 528 } | |
| 529 } | |
| 530 | |
| 531 if( p->flags&SQLITE_OPEN_MAIN_DB && p->pWritable ){ | |
| 532 if( iAmt<p->nPagesize | |
| 533 && p->nPagesize%iAmt==0 | |
| 534 && iOfst>=(PENDING_BYTE+512) | |
| 535 && iOfst+iAmt<=PENDING_BYTE+p->nPagesize | |
| 536 ){ | |
| 537 /* No-op. This special case is hit when the backup code is copying a | |
| 538 ** to a database with a larger page-size than the source database and | |
| 539 ** it needs to fill in the non-locking-region part of the original | |
| 540 ** pending-byte page. | |
| 541 */ | |
| 542 }else{ | |
| 543 u32 pgno = iOfst/p->nPagesize + 1; | |
| 544 assert( (iAmt==1||iAmt==p->nPagesize) && ((iOfst+iAmt)%p->nPagesize)==0 ); | |
| 545 assert( pgno<=p->nPage || p->nSync>0 ); | |
| 546 assert( pgno>p->nPage || sqlite3BitvecTest(p->pWritable, pgno) ); | |
| 547 } | |
| 548 } | |
| 549 | |
| 550 rc = sqlite3OsWrite(p->pReal, zBuf, iAmt, iOfst); | |
| 551 if( (p->flags&SQLITE_OPEN_MAIN_JOURNAL) && iAmt==12 ){ | |
| 552 jt_file *pMain = locateDatabaseHandle(p->zName); | |
| 553 int rc2 = readJournalFile(p, pMain); | |
| 554 if( rc==SQLITE_OK ) rc = rc2; | |
| 555 } | |
| 556 return rc; | |
| 557 } | |
| 558 | |
| 559 /* | |
| 560 ** Truncate an jt-file. | |
| 561 */ | |
| 562 static int jtTruncate(sqlite3_file *pFile, sqlite_int64 size){ | |
| 563 jt_file *p = (jt_file *)pFile; | |
| 564 if( p->flags&SQLITE_OPEN_MAIN_JOURNAL && size==0 ){ | |
| 565 /* Truncating a journal file. This is the end of a transaction. */ | |
| 566 jt_file *pMain = locateDatabaseHandle(p->zName); | |
| 567 closeTransaction(pMain); | |
| 568 } | |
| 569 if( p->flags&SQLITE_OPEN_MAIN_DB && p->pWritable ){ | |
| 570 u32 pgno; | |
| 571 u32 locking_page = (u32)(PENDING_BYTE/p->nPagesize+1); | |
| 572 for(pgno=size/p->nPagesize+1; pgno<=p->nPage; pgno++){ | |
| 573 assert( pgno==locking_page || sqlite3BitvecTest(p->pWritable, pgno) ); | |
| 574 } | |
| 575 } | |
| 576 return sqlite3OsTruncate(p->pReal, size); | |
| 577 } | |
| 578 | |
| 579 /* | |
| 580 ** Sync an jt-file. | |
| 581 */ | |
| 582 static int jtSync(sqlite3_file *pFile, int flags){ | |
| 583 jt_file *p = (jt_file *)pFile; | |
| 584 | |
| 585 if( p->flags&SQLITE_OPEN_MAIN_JOURNAL ){ | |
| 586 int rc; | |
| 587 jt_file *pMain; /* The associated database file */ | |
| 588 | |
| 589 /* The journal file is being synced. At this point, we inspect the | |
| 590 ** contents of the file up to this point and set each bit in the | |
| 591 ** jt_file.pWritable bitvec of the main database file associated with | |
| 592 ** this journal file. | |
| 593 */ | |
| 594 pMain = locateDatabaseHandle(p->zName); | |
| 595 assert(pMain); | |
| 596 | |
| 597 /* Set the bitvec values */ | |
| 598 if( pMain->pWritable ){ | |
| 599 pMain->nSync++; | |
| 600 rc = readJournalFile(p, pMain); | |
| 601 if( rc!=SQLITE_OK ){ | |
| 602 return rc; | |
| 603 } | |
| 604 } | |
| 605 } | |
| 606 | |
| 607 return sqlite3OsSync(p->pReal, flags); | |
| 608 } | |
| 609 | |
| 610 /* | |
| 611 ** Return the current file-size of an jt-file. | |
| 612 */ | |
| 613 static int jtFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){ | |
| 614 jt_file *p = (jt_file *)pFile; | |
| 615 return sqlite3OsFileSize(p->pReal, pSize); | |
| 616 } | |
| 617 | |
| 618 /* | |
| 619 ** Lock an jt-file. | |
| 620 */ | |
| 621 static int jtLock(sqlite3_file *pFile, int eLock){ | |
| 622 int rc; | |
| 623 jt_file *p = (jt_file *)pFile; | |
| 624 rc = sqlite3OsLock(p->pReal, eLock); | |
| 625 if( rc==SQLITE_OK && eLock>p->eLock ){ | |
| 626 p->eLock = eLock; | |
| 627 } | |
| 628 return rc; | |
| 629 } | |
| 630 | |
| 631 /* | |
| 632 ** Unlock an jt-file. | |
| 633 */ | |
| 634 static int jtUnlock(sqlite3_file *pFile, int eLock){ | |
| 635 int rc; | |
| 636 jt_file *p = (jt_file *)pFile; | |
| 637 rc = sqlite3OsUnlock(p->pReal, eLock); | |
| 638 if( rc==SQLITE_OK && eLock<p->eLock ){ | |
| 639 p->eLock = eLock; | |
| 640 } | |
| 641 return rc; | |
| 642 } | |
| 643 | |
| 644 /* | |
| 645 ** Check if another file-handle holds a RESERVED lock on an jt-file. | |
| 646 */ | |
| 647 static int jtCheckReservedLock(sqlite3_file *pFile, int *pResOut){ | |
| 648 jt_file *p = (jt_file *)pFile; | |
| 649 return sqlite3OsCheckReservedLock(p->pReal, pResOut); | |
| 650 } | |
| 651 | |
| 652 /* | |
| 653 ** File control method. For custom operations on an jt-file. | |
| 654 */ | |
| 655 static int jtFileControl(sqlite3_file *pFile, int op, void *pArg){ | |
| 656 jt_file *p = (jt_file *)pFile; | |
| 657 return sqlite3OsFileControl(p->pReal, op, pArg); | |
| 658 } | |
| 659 | |
| 660 /* | |
| 661 ** Return the sector-size in bytes for an jt-file. | |
| 662 */ | |
| 663 static int jtSectorSize(sqlite3_file *pFile){ | |
| 664 jt_file *p = (jt_file *)pFile; | |
| 665 return sqlite3OsSectorSize(p->pReal); | |
| 666 } | |
| 667 | |
| 668 /* | |
| 669 ** Return the device characteristic flags supported by an jt-file. | |
| 670 */ | |
| 671 static int jtDeviceCharacteristics(sqlite3_file *pFile){ | |
| 672 jt_file *p = (jt_file *)pFile; | |
| 673 return sqlite3OsDeviceCharacteristics(p->pReal); | |
| 674 } | |
| 675 | |
| 676 /* | |
| 677 ** Open an jt file handle. | |
| 678 */ | |
| 679 static int jtOpen( | |
| 680 sqlite3_vfs *pVfs, | |
| 681 const char *zName, | |
| 682 sqlite3_file *pFile, | |
| 683 int flags, | |
| 684 int *pOutFlags | |
| 685 ){ | |
| 686 int rc; | |
| 687 jt_file *p = (jt_file *)pFile; | |
| 688 pFile->pMethods = 0; | |
| 689 p->pReal = (sqlite3_file *)&p[1]; | |
| 690 p->pReal->pMethods = 0; | |
| 691 rc = sqlite3OsOpen(g.pVfs, zName, p->pReal, flags, pOutFlags); | |
| 692 assert( rc==SQLITE_OK || p->pReal->pMethods==0 ); | |
| 693 if( rc==SQLITE_OK ){ | |
| 694 pFile->pMethods = &jt_io_methods; | |
| 695 p->eLock = 0; | |
| 696 p->zName = zName; | |
| 697 p->flags = flags; | |
| 698 p->pNext = 0; | |
| 699 p->pWritable = 0; | |
| 700 p->aCksum = 0; | |
| 701 enterJtMutex(); | |
| 702 if( zName ){ | |
| 703 p->pNext = g.pList; | |
| 704 g.pList = p; | |
| 705 } | |
| 706 leaveJtMutex(); | |
| 707 } | |
| 708 return rc; | |
| 709 } | |
| 710 | |
| 711 /* | |
| 712 ** Delete the file located at zPath. If the dirSync argument is true, | |
| 713 ** ensure the file-system modifications are synced to disk before | |
| 714 ** returning. | |
| 715 */ | |
| 716 static int jtDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){ | |
| 717 int nPath = strlen(zPath); | |
| 718 if( nPath>8 && 0==strcmp("-journal", &zPath[nPath-8]) ){ | |
| 719 /* Deleting a journal file. The end of a transaction. */ | |
| 720 jt_file *pMain = locateDatabaseHandle(zPath); | |
| 721 if( pMain ){ | |
| 722 closeTransaction(pMain); | |
| 723 } | |
| 724 } | |
| 725 | |
| 726 return sqlite3OsDelete(g.pVfs, zPath, dirSync); | |
| 727 } | |
| 728 | |
| 729 /* | |
| 730 ** Test for access permissions. Return true if the requested permission | |
| 731 ** is available, or false otherwise. | |
| 732 */ | |
| 733 static int jtAccess( | |
| 734 sqlite3_vfs *pVfs, | |
| 735 const char *zPath, | |
| 736 int flags, | |
| 737 int *pResOut | |
| 738 ){ | |
| 739 return sqlite3OsAccess(g.pVfs, zPath, flags, pResOut); | |
| 740 } | |
| 741 | |
| 742 /* | |
| 743 ** Populate buffer zOut with the full canonical pathname corresponding | |
| 744 ** to the pathname in zPath. zOut is guaranteed to point to a buffer | |
| 745 ** of at least (JT_MAX_PATHNAME+1) bytes. | |
| 746 */ | |
| 747 static int jtFullPathname( | |
| 748 sqlite3_vfs *pVfs, | |
| 749 const char *zPath, | |
| 750 int nOut, | |
| 751 char *zOut | |
| 752 ){ | |
| 753 return sqlite3OsFullPathname(g.pVfs, zPath, nOut, zOut); | |
| 754 } | |
| 755 | |
| 756 /* | |
| 757 ** Open the dynamic library located at zPath and return a handle. | |
| 758 */ | |
| 759 static void *jtDlOpen(sqlite3_vfs *pVfs, const char *zPath){ | |
| 760 return g.pVfs->xDlOpen(g.pVfs, 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 jtDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){ | |
| 769 g.pVfs->xDlError(g.pVfs, nByte, zErrMsg); | |
| 770 } | |
| 771 | |
| 772 /* | |
| 773 ** Return a pointer to the symbol zSymbol in the dynamic library pHandle. | |
| 774 */ | |
| 775 static void (*jtDlSym(sqlite3_vfs *pVfs, void *p, const char *zSym))(void){ | |
| 776 return g.pVfs->xDlSym(g.pVfs, p, zSym); | |
| 777 } | |
| 778 | |
| 779 /* | |
| 780 ** Close the dynamic library handle pHandle. | |
| 781 */ | |
| 782 static void jtDlClose(sqlite3_vfs *pVfs, void *pHandle){ | |
| 783 g.pVfs->xDlClose(g.pVfs, pHandle); | |
| 784 } | |
| 785 | |
| 786 /* | |
| 787 ** Populate the buffer pointed to by zBufOut with nByte bytes of | |
| 788 ** random data. | |
| 789 */ | |
| 790 static int jtRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){ | |
| 791 return sqlite3OsRandomness(g.pVfs, nByte, zBufOut); | |
| 792 } | |
| 793 | |
| 794 /* | |
| 795 ** Sleep for nMicro microseconds. Return the number of microseconds | |
| 796 ** actually slept. | |
| 797 */ | |
| 798 static int jtSleep(sqlite3_vfs *pVfs, int nMicro){ | |
| 799 return sqlite3OsSleep(g.pVfs, nMicro); | |
| 800 } | |
| 801 | |
| 802 /* | |
| 803 ** Return the current time as a Julian Day number in *pTimeOut. | |
| 804 */ | |
| 805 static int jtCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){ | |
| 806 return sqlite3OsCurrentTime(g.pVfs, pTimeOut); | |
| 807 } | |
| 808 | |
| 809 /************************************************************************** | |
| 810 ** Start of public API. | |
| 811 */ | |
| 812 | |
| 813 /* | |
| 814 ** Configure the jt VFS as a wrapper around the VFS named by parameter | |
| 815 ** zWrap. If the isDefault parameter is true, then the jt VFS is installed | |
| 816 ** as the new default VFS for SQLite connections. If isDefault is not | |
| 817 ** true, then the jt VFS is installed as non-default. In this case it | |
| 818 ** is available via its name, "jt". | |
| 819 */ | |
| 820 int jt_register(char *zWrap, int isDefault){ | |
| 821 g.pVfs = sqlite3_vfs_find(zWrap); | |
| 822 if( g.pVfs==0 ){ | |
| 823 return SQLITE_ERROR; | |
| 824 } | |
| 825 jt_vfs.szOsFile = sizeof(jt_file) + g.pVfs->szOsFile; | |
| 826 sqlite3_vfs_register(&jt_vfs, isDefault); | |
| 827 return SQLITE_OK; | |
| 828 } | |
| 829 | |
| 830 /* | |
| 831 ** Uninstall the jt VFS, if it is installed. | |
| 832 */ | |
| 833 void jt_unregister(void){ | |
| 834 sqlite3_vfs_unregister(&jt_vfs); | |
| 835 } | |
| 836 | |
| 837 #endif | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 3108030:
Move bundled copy of sqlite one level deeper to better separate it... (Closed)
Base URL: svn://svn.chromium.org/chrome/trunk/src/