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Overview
Comment: | Modify some comments in pager.c. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | experimental |
Files: | files | file ages | folders |
SHA1: |
5662da6d4f648e5d07d7cbea6bbd92fa |
User & Date: | dan 2010-08-09 19:17:29.000 |
Context
2010-08-10
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09:58 | Add variable pager.dbHintSize, used to limit the number of calls made to the xFileControl(FCNTL_SIZE_HINT) method. (check-in: eb3ac895bd user: dan tags: experimental) | |
2010-08-09
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19:17 | Modify some comments in pager.c. (check-in: 5662da6d4f user: dan tags: experimental) | |
16:52 | Merge latest trunk changes with experimental branch. (check-in: aecbd89032 user: dan tags: experimental) | |
Changes
Changes to src/pager.c.
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236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 | ** * A write transaction is active. ** * A RESERVED or greater lock is held on the database file. ** * The journal file is open and the first header has been written ** to it, but the header has not been synced to disk. ** * The contents of the page cache have been modified. ** ** WRITER_DBMOD: ** ** * A write transaction is active. ** * An EXCLUSIVE or greater lock is held on the database file. ** * The journal file is open and the first header has been written ** and synced to disk. ** * The contents of the page cache have been modified (and possibly ** written to disk). ** ** WRITER_FINISHED: ** ** * A write transaction is active. ** * An EXCLUSIVE or greater lock is held on the database file. ** * All writing and syncing of journal and database data has finished. ** If no error occured, all that remains is to finalize the journal to ** commit the transaction. If an error did occur, the caller will need ** to rollback the transaction. | > > > > > > > > > > > > > > | 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 | ** * A write transaction is active. ** * A RESERVED or greater lock is held on the database file. ** * The journal file is open and the first header has been written ** to it, but the header has not been synced to disk. ** * The contents of the page cache have been modified. ** ** WRITER_DBMOD: ** ** The pager transitions from WRITER_CACHEMOD into WRITER_DBMOD state ** when it modifies the contents of the database file. WAL connections ** never enter this state (since they do not modify the database file, ** just the log file). ** ** * A write transaction is active. ** * An EXCLUSIVE or greater lock is held on the database file. ** * The journal file is open and the first header has been written ** and synced to disk. ** * The contents of the page cache have been modified (and possibly ** written to disk). ** ** WRITER_FINISHED: ** ** It is not possible for a WAL connection to enter this state. ** ** A rollback-mode pager changes to WRITER_FINISHED state from WRITER_DBMOD ** state after the entire transaction has been successfully written into the ** database file. In this state the transaction may be committed simply ** by finalizing the journal file. Once in WRITER_FINISHED state, it is ** not possible to modify the database further. At this point, the upper ** layer must either commit or rollback the transaction. ** ** * A write transaction is active. ** * An EXCLUSIVE or greater lock is held on the database file. ** * All writing and syncing of journal and database data has finished. ** If no error occured, all that remains is to finalize the journal to ** commit the transaction. If an error did occur, the caller will need ** to rollback the transaction. |
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1638 1639 1640 1641 1642 1643 1644 | assert( rc==SQLITE_OK || rc==SQLITE_NOMEM ); } } return rc; } /* | | > | | | | > > | > > > | > > > > > > | 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 | assert( rc==SQLITE_OK || rc==SQLITE_NOMEM ); } } return rc; } /* ** This function is a no-op if the pager is in exclusive mode and not ** in the ERROR state. Otherwise, it switches the pager to PAGER_OPEN ** state. ** ** If the pager is not in exclusive-access mode, the database file is ** completely unlocked. If the file is unlocked and the file-system does ** not exhibit the UNDELETABLE_WHEN_OPEN property, the journal file is ** closed (if it is open). ** ** If the pager is in ERROR state when this function is called, the ** contents of the pager cache are discarded before switching back to ** the OPEN state. Regardless of whether the pager is in exclusive-mode ** or not, any journal file left in the file-system will be treated ** as a hot-journal and rolled back the next time a read-transaction ** is opened (by this or by any other connection). */ static void pager_unlock(Pager *pPager){ assert( pPager->eState==PAGER_READER || pPager->eState==PAGER_OPEN || pPager->eState==PAGER_ERROR ); sqlite3BitvecDestroy(pPager->pInJournal); pPager->pInJournal = 0; releaseAllSavepoints(pPager); if( pagerUseWal(pPager) ){ assert( !isOpen(pPager->jfd) ); |
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1715 1716 1717 1718 1719 1720 1721 | pPager->journalOff = 0; pPager->journalHdr = 0; pPager->setMaster = 0; } /* | | > | | | < | | > | | > | | 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 | pPager->journalOff = 0; pPager->journalHdr = 0; pPager->setMaster = 0; } /* ** This function is called whenever an IOERR or FULL error that requires ** the pager to transition into the ERROR state may ahve occurred. ** The first argument is a pointer to the pager structure, the second ** the error-code about to be returned by a pager API function. The ** value returned is a copy of the second argument to this function. ** ** If the second argument is SQLITE_FULL, SQLITE_IOERR or one of the ** IOERR sub-codes, the pager enters the ERROR state and the error code ** is stored in Pager.errCode. While the pager remains in the ERROR state, ** all major API calls on the Pager will immediately return Pager.errCode. ** Except, if the error-code is SQLITE_FULL, calls to PagerLookup() and ** PagerAcquire are handled as if the pager were in PAGER_READER state. ** ** The ERROR state indicates that the contents of the pager-cache ** cannot be trusted. This state can be cleared by completely discarding ** the contents of the pager-cache. If a transaction was active when ** the persistent error occurred, then the rollback journal may need ** to be replayed to restore the contents of the database file (as if ** it were a hot-journal). */ static int pager_error(Pager *pPager, int rc){ |
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2083 2084 2085 2086 2087 2088 2089 | /* When playing back page 1, restore the nReserve setting */ if( pgno==1 && pPager->nReserve!=((u8*)aData)[20] ){ pPager->nReserve = ((u8*)aData)[20]; pagerReportSize(pPager); } | | | | > > > | 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 | /* When playing back page 1, restore the nReserve setting */ if( pgno==1 && pPager->nReserve!=((u8*)aData)[20] ){ pPager->nReserve = ((u8*)aData)[20]; pagerReportSize(pPager); } /* If the pager is in CACHEMOD state, then there must be a copy of this ** page in the pager cache. In this case just update the pager cache, ** not the database file. The page is left marked dirty in this case. ** ** An exception to the above rule: If the database is in no-sync mode ** and a page is moved during an incremental vacuum then the page may ** not be in the pager cache. Later: if a malloc() or IO error occurs ** during a Movepage() call, then the page may not be in the cache ** either. So the condition described in the above paragraph is not ** assert()able. ** ** If in WRITER_DBMOD, WRITER_FINISHED or OPEN state, then we update the ** pager cache if it exists and the main file. The page is then marked ** not dirty. Since this code is only executed in PAGER_OPEN state for ** a hot-journal rollback, it is guaranteed that the page-cache is empty ** if the pager is in OPEN state. ** ** Ticket #1171: The statement journal might contain page content that is ** different from the page content at the start of the transaction. ** This occurs when a page is changed prior to the start of a statement ** then changed again within the statement. When rolling back such a ** statement we must not write to the original database unless we know ** for certain that original page contents are synced into the main rollback |
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2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 | */ if( pagerUseWal(pPager) ){ pPg = 0; }else{ pPg = pager_lookup(pPager, pgno); } assert( pPg || !MEMDB ); PAGERTRACE(("PLAYBACK %d page %d hash(%08x) %s\n", PAGERID(pPager), pgno, pager_datahash(pPager->pageSize, (u8*)aData), (isMainJrnl?"main-journal":"sub-journal") )); if( isMainJrnl ){ isSynced = pPager->noSync || (*pOffset <= pPager->journalHdr); }else{ | > | 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 | */ if( pagerUseWal(pPager) ){ pPg = 0; }else{ pPg = pager_lookup(pPager, pgno); } assert( pPg || !MEMDB ); assert( pPager->eState!=PAGER_OPEN || pPg==0 ); PAGERTRACE(("PLAYBACK %d page %d hash(%08x) %s\n", PAGERID(pPager), pgno, pager_datahash(pPager->pageSize, (u8*)aData), (isMainJrnl?"main-journal":"sub-journal") )); if( isMainJrnl ){ isSynced = pPager->noSync || (*pOffset <= pPager->journalHdr); }else{ |
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2361 2362 2363 2364 2365 2366 2367 | /* ** This function is used to change the actual size of the database ** file in the file-system. This only happens when committing a transaction, ** or rolling back a transaction (including rolling back a hot-journal). ** | | | | | > | 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 | /* ** This function is used to change the actual size of the database ** file in the file-system. This only happens when committing a transaction, ** or rolling back a transaction (including rolling back a hot-journal). ** ** If the main database file is not open, or the pager is not in either ** DBMOD or OPEN state, this function is a no-op. Otherwise, the size ** of the file is changed to nPage pages (nPage*pPager->pageSize bytes). ** If the file on disk is currently larger than nPage pages, then use the VFS ** xTruncate() method to truncate it. ** ** Or, it might might be the case that the file on disk is smaller than ** nPage pages. Some operating system implementations can get confused if ** you try to truncate a file to some size that is larger than it ** currently is, so detect this case and write a single zero byte to ** the end of the new file instead. ** ** If successful, return SQLITE_OK. If an IO error occurs while modifying ** the database file, return the error code to the caller. */ static int pager_truncate(Pager *pPager, Pgno nPage){ int rc = SQLITE_OK; assert( pPager->eState!=PAGER_ERROR ); assert( pPager->eState!=PAGER_READER ); if( isOpen(pPager->fd) && (pPager->eState>=PAGER_WRITER_DBMOD || pPager->eState==PAGER_OPEN) ){ i64 currentSize, newSize; assert( pPager->eLock==EXCLUSIVE_LOCK ); /* TODO: Is it safe to use Pager.dbFileSize here? */ rc = sqlite3OsFileSize(pPager->fd, ¤tSize); newSize = pPager->pageSize*(i64)nPage; if( rc==SQLITE_OK && currentSize!=newSize ){ if( currentSize>newSize ){ rc = sqlite3OsTruncate(pPager->fd, newSize); }else{ |
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