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Overview
Comment: | Allocate a buffer containing the full path-name to the associated WAL file when a pager is created. This saves having to construct a new buffer each time a new read-transaction is opened and SQLite checks for the existance of a WAL file. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
3053a4ad15343a56efa430503797b77b |
User & Date: | dan 2010-07-05 19:03:36.000 |
Context
2010-07-05
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19:13 | Simplify the previous commit by removing the pagerCheckForOrDeleteWAL() wrapper. (check-in: a1324d125e user: dan tags: trunk) | |
19:03 | Allocate a buffer containing the full path-name to the associated WAL file when a pager is created. This saves having to construct a new buffer each time a new read-transaction is opened and SQLite checks for the existance of a WAL file. (check-in: 3053a4ad15 user: dan tags: trunk) | |
17:43 | When rolling back page 1 from a journal, restore the "nReserve" setting in case it has been corrupted by a prior crash. (check-in: c0d124da88 user: drh tags: trunk) | |
Changes
Changes to src/pager.c.
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403 404 405 406 407 408 409 410 411 412 413 414 415 416 | void *pCodec; /* First argument to xCodec... methods */ #endif char *pTmpSpace; /* Pager.pageSize bytes of space for tmp use */ PCache *pPCache; /* Pointer to page cache object */ sqlite3_backup *pBackup; /* Pointer to list of ongoing backup processes */ #ifndef SQLITE_OMIT_WAL Wal *pWal; /* Write-ahead log used by "journal_mode=wal" */ #endif }; /* ** The following global variables hold counters used for ** testing purposes only. These variables do not exist in ** a non-testing build. These variables are not thread-safe. | > | 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 | void *pCodec; /* First argument to xCodec... methods */ #endif char *pTmpSpace; /* Pager.pageSize bytes of space for tmp use */ PCache *pPCache; /* Pointer to page cache object */ sqlite3_backup *pBackup; /* Pointer to list of ongoing backup processes */ #ifndef SQLITE_OMIT_WAL Wal *pWal; /* Write-ahead log used by "journal_mode=wal" */ char *zWal; /* File name for write-ahead log */ #endif }; /* ** The following global variables hold counters used for ** testing purposes only. These variables do not exist in ** a non-testing build. These variables are not thread-safe. |
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2448 2449 2450 2451 2452 2453 2454 | ** nothing if the *-wal file does not exist. ** ** Return SQLITE_OK on success. If on an IO or OOM error occurs, return ** an SQLite error code. */ static int pagerCheckForOrDeleteWAL(Pager *pPager, int *pExists){ int rc; /* Return code */ | | < < < < | | | | < < | 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 | ** nothing if the *-wal file does not exist. ** ** Return SQLITE_OK on success. If on an IO or OOM error occurs, return ** an SQLite error code. */ static int pagerCheckForOrDeleteWAL(Pager *pPager, int *pExists){ int rc; /* Return code */ char *zWal = pPager->zWal; /* Name of the WAL file */ assert( !pPager->tempFile ); if( pExists ){ rc = sqlite3OsAccess(pPager->pVfs, zWal, SQLITE_ACCESS_EXISTS, pExists); }else{ rc = sqlite3OsDelete(pPager->pVfs, zWal, 0); } return rc; } /* ** Check if the *-wal file that corresponds to the database opened by pPager ** exists if the database is not empy, or verify that the *-wal file does |
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3761 3762 3763 3764 3765 3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 | pPtr = (u8 *)sqlite3MallocZero( ROUND8(sizeof(*pPager)) + /* Pager structure */ ROUND8(pcacheSize) + /* PCache object */ ROUND8(pVfs->szOsFile) + /* The main db file */ journalFileSize * 2 + /* The two journal files */ nPathname + 1 + /* zFilename */ nPathname + 8 + 1 /* zJournal */ ); assert( EIGHT_BYTE_ALIGNMENT(SQLITE_INT_TO_PTR(journalFileSize)) ); if( !pPtr ){ sqlite3_free(zPathname); return SQLITE_NOMEM; } pPager = (Pager*)(pPtr); pPager->pPCache = (PCache*)(pPtr += ROUND8(sizeof(*pPager))); pPager->fd = (sqlite3_file*)(pPtr += ROUND8(pcacheSize)); pPager->sjfd = (sqlite3_file*)(pPtr += ROUND8(pVfs->szOsFile)); pPager->jfd = (sqlite3_file*)(pPtr += journalFileSize); pPager->zFilename = (char*)(pPtr += journalFileSize); assert( EIGHT_BYTE_ALIGNMENT(pPager->jfd) ); /* Fill in the Pager.zFilename and Pager.zJournal buffers, if required. */ if( zPathname ){ pPager->zJournal = (char*)(pPtr += nPathname + 1); memcpy(pPager->zFilename, zPathname, nPathname); memcpy(pPager->zJournal, zPathname, nPathname); memcpy(&pPager->zJournal[nPathname], "-journal", 8); | > > > | > > > > > > > > > | 3756 3757 3758 3759 3760 3761 3762 3763 3764 3765 3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795 3796 3797 3798 3799 3800 3801 3802 | pPtr = (u8 *)sqlite3MallocZero( ROUND8(sizeof(*pPager)) + /* Pager structure */ ROUND8(pcacheSize) + /* PCache object */ ROUND8(pVfs->szOsFile) + /* The main db file */ journalFileSize * 2 + /* The two journal files */ nPathname + 1 + /* zFilename */ nPathname + 8 + 1 /* zJournal */ #ifndef SQLITE_OMIT_WAL + nPathname + 4 + 1 /* zWal */ #endif ); assert( EIGHT_BYTE_ALIGNMENT(SQLITE_INT_TO_PTR(journalFileSize)) ); if( !pPtr ){ sqlite3_free(zPathname); return SQLITE_NOMEM; } pPager = (Pager*)(pPtr); pPager->pPCache = (PCache*)(pPtr += ROUND8(sizeof(*pPager))); pPager->fd = (sqlite3_file*)(pPtr += ROUND8(pcacheSize)); pPager->sjfd = (sqlite3_file*)(pPtr += ROUND8(pVfs->szOsFile)); pPager->jfd = (sqlite3_file*)(pPtr += journalFileSize); pPager->zFilename = (char*)(pPtr += journalFileSize); assert( EIGHT_BYTE_ALIGNMENT(pPager->jfd) ); /* Fill in the Pager.zFilename and Pager.zJournal buffers, if required. */ if( zPathname ){ pPager->zJournal = (char*)(pPtr += nPathname + 1); memcpy(pPager->zFilename, zPathname, nPathname); memcpy(pPager->zJournal, zPathname, nPathname); memcpy(&pPager->zJournal[nPathname], "-journal", 8); if( pPager->zFilename[0]==0 ){ pPager->zJournal[0] = 0; } #ifndef SQLITE_OMIT_WAL else{ pPager->zWal = &pPager->zJournal[nPathname+8+1]; memcpy(pPager->zWal, zPathname, nPathname); memcpy(&pPager->zWal[nPathname], "-wal", 4); } #endif sqlite3_free(zPathname); } pPager->pVfs = pVfs; pPager->vfsFlags = vfsFlags; /* Open the pager file. */ |
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6074 6075 6076 6077 6078 6079 6080 | if( !sqlite3PagerWalSupported(pPager) ) return SQLITE_CANTOPEN; /* Open the connection to the log file. If this operation fails, ** (e.g. due to malloc() failure), unlock the database file and ** return an error code. */ rc = sqlite3WalOpen(pPager->pVfs, pPager->fd, | | | 6081 6082 6083 6084 6085 6086 6087 6088 6089 6090 6091 6092 6093 6094 6095 | if( !sqlite3PagerWalSupported(pPager) ) return SQLITE_CANTOPEN; /* Open the connection to the log file. If this operation fails, ** (e.g. due to malloc() failure), unlock the database file and ** return an error code. */ rc = sqlite3WalOpen(pPager->pVfs, pPager->fd, pPager->zWal, &pPager->pWal); if( rc==SQLITE_OK ){ pPager->journalMode = PAGER_JOURNALMODE_WAL; } }else{ *pisOpen = 1; } |
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6111 6112 6113 6114 6115 6116 6117 | int logexists = 0; rc = sqlite3OsLock(pPager->fd, SQLITE_LOCK_SHARED); if( rc==SQLITE_OK ){ rc = pagerCheckForOrDeleteWAL(pPager, &logexists); } if( rc==SQLITE_OK && logexists ){ rc = sqlite3WalOpen(pPager->pVfs, pPager->fd, | | | 6118 6119 6120 6121 6122 6123 6124 6125 6126 6127 6128 6129 6130 6131 6132 | int logexists = 0; rc = sqlite3OsLock(pPager->fd, SQLITE_LOCK_SHARED); if( rc==SQLITE_OK ){ rc = pagerCheckForOrDeleteWAL(pPager, &logexists); } if( rc==SQLITE_OK && logexists ){ rc = sqlite3WalOpen(pPager->pVfs, pPager->fd, pPager->zWal, &pPager->pWal); } } /* Checkpoint and close the log. Because an EXCLUSIVE lock is held on ** the database file, the log and log-summary files will be deleted. */ if( rc==SQLITE_OK && pPager->pWal ){ |
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Changes to src/wal.c.
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413 414 415 416 417 418 419 | u16 szPage; /* Database page size */ i16 readLock; /* Which read lock is being held. -1 for none */ u8 exclusiveMode; /* Non-zero if connection is in exclusive mode */ u8 isWIndexOpen; /* True if ShmOpen() called on pDbFd */ u8 writeLock; /* True if in a write transaction */ u8 ckptLock; /* True if holding a checkpoint lock */ WalIndexHdr hdr; /* Wal-index header for current transaction */ | | | 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 | u16 szPage; /* Database page size */ i16 readLock; /* Which read lock is being held. -1 for none */ u8 exclusiveMode; /* Non-zero if connection is in exclusive mode */ u8 isWIndexOpen; /* True if ShmOpen() called on pDbFd */ u8 writeLock; /* True if in a write transaction */ u8 ckptLock; /* True if holding a checkpoint lock */ WalIndexHdr hdr; /* Wal-index header for current transaction */ const char *zWalName; /* Name of WAL file */ u32 nCkpt; /* Checkpoint sequence counter in the wal-header */ #ifdef SQLITE_DEBUG u8 lockError; /* True if a locking error has occurred */ #endif }; /* |
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1168 1169 1170 1171 1172 1173 1174 | if( pWal->isWIndexOpen ){ sqlite3OsShmClose(pWal->pDbFd, isDelete); pWal->isWIndexOpen = 0; } } /* | | | > | < < | < | | < | | 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 | if( pWal->isWIndexOpen ){ sqlite3OsShmClose(pWal->pDbFd, isDelete); pWal->isWIndexOpen = 0; } } /* ** Open a connection to the WAL file zWalName. The database file must ** already be opened on connection pDbFd. The buffer that zWalName points ** to must remain valid for the lifetime of the returned Wal* handle. ** ** A SHARED lock should be held on the database file when this function ** is called. The purpose of this SHARED lock is to prevent any other ** client from unlinking the WAL or wal-index file. If another process ** were to do this just after this client opened one of these files, the ** system would be badly broken. ** ** If the log file is successfully opened, SQLITE_OK is returned and ** *ppWal is set to point to a new WAL handle. If an error occurs, ** an SQLite error code is returned and *ppWal is left unmodified. */ int sqlite3WalOpen( sqlite3_vfs *pVfs, /* vfs module to open wal and wal-index */ sqlite3_file *pDbFd, /* The open database file */ const char *zWalName, /* Name of the WAL file */ Wal **ppWal /* OUT: Allocated Wal handle */ ){ int rc; /* Return Code */ Wal *pRet; /* Object to allocate and return */ int flags; /* Flags passed to OsOpen() */ assert( zWalName && zWalName[0] ); assert( pDbFd ); /* In the amalgamation, the os_unix.c and os_win.c source files come before ** this source file. Verify that the #defines of the locking byte offsets ** in os_unix.c and os_win.c agree with the WALINDEX_LOCK_OFFSET value. */ #ifdef WIN_SHM_BASE assert( WIN_SHM_BASE==WALINDEX_LOCK_OFFSET ); #endif #ifdef UNIX_SHM_BASE assert( UNIX_SHM_BASE==WALINDEX_LOCK_OFFSET ); #endif /* Allocate an instance of struct Wal to return. */ *ppWal = 0; pRet = (Wal*)sqlite3MallocZero(sizeof(Wal) + pVfs->szOsFile); if( !pRet ){ return SQLITE_NOMEM; } pRet->pVfs = pVfs; pRet->pWalFd = (sqlite3_file *)&pRet[1]; pRet->pDbFd = pDbFd; pRet->readLock = -1; sqlite3_randomness(8, &pRet->hdr.aSalt); pRet->zWalName = zWalName; rc = sqlite3OsShmOpen(pDbFd); /* Open file handle on the write-ahead log file. */ if( rc==SQLITE_OK ){ pRet->isWIndexOpen = 1; flags = (SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|SQLITE_OPEN_MAIN_JOURNAL); rc = sqlite3OsOpen(pVfs, zWalName, pRet->pWalFd, flags, &flags); } if( rc!=SQLITE_OK ){ walIndexClose(pRet, 0); sqlite3OsClose(pRet->pWalFd); sqlite3_free(pRet); }else{ |
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