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Overview
Comment: | Performance optimizations in the pager_write() routine of pager.c. |
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SHA1: |
bc5febef921bd12ca7760e9d07d3be0e |
User & Date: | drh 2013-12-13 20:45:50.607 |
Context
2013-12-14
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13:44 | Allow the SQLITE_DETERMINISTIC flag to be ORed into the preferred text encoding of application-defined functions, to mark the function as deterministic. (check-in: 5716fc2341 user: drh tags: trunk) | |
2013-12-13
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20:45 | Performance optimizations in the pager_write() routine of pager.c. (check-in: bc5febef92 user: drh tags: trunk) | |
19:48 | Reduce the number of calls to the subjRequiresPage() routine inside of pager. (check-in: e50ff39a93 user: drh tags: trunk) | |
Changes
Changes to src/pager.c.
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1034 1035 1036 1037 1038 1039 1040 | } return 0; } /* ** Return true if the page is already in the journal file. */ | | | | 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 | } return 0; } /* ** Return true if the page is already in the journal file. */ static int pageInJournal(Pager *pPager, PgHdr *pPg){ return sqlite3BitvecTest(pPager->pInJournal, pPg->pgno); } /* ** Read a 32-bit integer from the given file descriptor. Store the integer ** that is read in *pRes. Return SQLITE_OK if everything worked, or an ** error code is something goes wrong. ** |
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4331 4332 4333 4334 4335 4336 4337 | if( pPager->journalMode!=PAGER_JOURNALMODE_OFF ){ /* Open the sub-journal, if it has not already been opened */ assert( pPager->useJournal ); assert( isOpen(pPager->jfd) || pagerUseWal(pPager) ); assert( isOpen(pPager->sjfd) || pPager->nSubRec==0 ); assert( pagerUseWal(pPager) | | | 4331 4332 4333 4334 4335 4336 4337 4338 4339 4340 4341 4342 4343 4344 4345 | if( pPager->journalMode!=PAGER_JOURNALMODE_OFF ){ /* Open the sub-journal, if it has not already been opened */ assert( pPager->useJournal ); assert( isOpen(pPager->jfd) || pagerUseWal(pPager) ); assert( isOpen(pPager->sjfd) || pPager->nSubRec==0 ); assert( pagerUseWal(pPager) || pageInJournal(pPager, pPg) || pPg->pgno>pPager->dbOrigSize ); rc = openSubJournal(pPager); /* If the sub-journal was opened successfully (or was already open), ** write the journal record into the file. */ if( rc==SQLITE_OK ){ |
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5632 5633 5634 5635 5636 5637 5638 | ** Mark a single data page as writeable. The page is written into the ** main journal or sub-journal as required. If the page is written into ** one of the journals, the corresponding bit is set in the ** Pager.pInJournal bitvec and the PagerSavepoint.pInSavepoint bitvecs ** of any open savepoints as appropriate. */ static int pager_write(PgHdr *pPg){ | < > | 5632 5633 5634 5635 5636 5637 5638 5639 5640 5641 5642 5643 5644 5645 5646 5647 5648 | ** Mark a single data page as writeable. The page is written into the ** main journal or sub-journal as required. If the page is written into ** one of the journals, the corresponding bit is set in the ** Pager.pInJournal bitvec and the PagerSavepoint.pInSavepoint bitvecs ** of any open savepoints as appropriate. */ static int pager_write(PgHdr *pPg){ Pager *pPager = pPg->pPager; int rc = SQLITE_OK; int inJournal; /* This routine is not called unless a write-transaction has already ** been started. The journal file may or may not be open at this point. ** It is never called in the ERROR state. */ assert( pPager->eState==PAGER_WRITER_LOCKED || pPager->eState==PAGER_WRITER_CACHEMOD |
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5670 5671 5672 5673 5674 5675 5676 | assert( pPager->eState>=PAGER_WRITER_CACHEMOD ); assert( assert_pager_state(pPager) ); /* Mark the page as dirty. If the page has already been written ** to the journal then we can return right away. */ sqlite3PcacheMakeDirty(pPg); | > | | | | 5670 5671 5672 5673 5674 5675 5676 5677 5678 5679 5680 5681 5682 5683 5684 5685 5686 5687 5688 5689 5690 5691 5692 5693 5694 5695 5696 5697 5698 5699 5700 5701 5702 5703 5704 5705 5706 | assert( pPager->eState>=PAGER_WRITER_CACHEMOD ); assert( assert_pager_state(pPager) ); /* Mark the page as dirty. If the page has already been written ** to the journal then we can return right away. */ sqlite3PcacheMakeDirty(pPg); inJournal = pageInJournal(pPager, pPg); if( inJournal && (pPager->nSavepoint==0 || !subjRequiresPage(pPg)) ){ assert( !pagerUseWal(pPager) ); }else{ /* The transaction journal now exists and we have a RESERVED or an ** EXCLUSIVE lock on the main database file. Write the current page to ** the transaction journal if it is not there already. */ if( !inJournal && !pagerUseWal(pPager) ){ assert( pagerUseWal(pPager)==0 ); if( pPg->pgno<=pPager->dbOrigSize && isOpen(pPager->jfd) ){ u32 cksum; char *pData2; i64 iOff = pPager->journalOff; /* We should never write to the journal file the page that ** contains the database locks. The following assert verifies ** that we do not. */ assert( pPg->pgno!=PAGER_MJ_PGNO(pPager) ); assert( pPager->journalHdr<=pPager->journalOff ); CODEC2(pPager, pPg->pData, pPg->pgno, 7, return SQLITE_NOMEM, pData2); cksum = pager_cksum(pPager, (u8*)pData2); /* Even if an IO or diskfull error occurs while journalling the ** page in the block above, set the need-sync flag for the page. ** Otherwise, when the transaction is rolled back, the logic in ** playback_one_page() will think that the page needs to be restored ** in the database file. And if an IO error occurs while doing so, |
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5743 5744 5745 5746 5747 5748 5749 | } /* If the statement journal is open and the page is not in it, ** then write the current page to the statement journal. Note that ** the statement journal format differs from the standard journal format ** in that it omits the checksums and the header. */ | | | 5744 5745 5746 5747 5748 5749 5750 5751 5752 5753 5754 5755 5756 5757 5758 | } /* If the statement journal is open and the page is not in it, ** then write the current page to the statement journal. Note that ** the statement journal format differs from the standard journal format ** in that it omits the checksums and the header. */ if( pPager->nSavepoint>0 && subjRequiresPage(pPg) ){ rc = subjournalPage(pPg); } } /* Update the database size and return. */ if( pPager->dbSize<pPg->pgno ){ |
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6745 6746 6747 6748 6749 6750 6751 | ** If the isCommit flag is set, there is no need to remember that ** the journal needs to be sync()ed before database page pPg->pgno ** can be written to. The caller has already promised not to write to it. */ if( (pPg->flags&PGHDR_NEED_SYNC) && !isCommit ){ needSyncPgno = pPg->pgno; assert( pPager->journalMode==PAGER_JOURNALMODE_OFF || | | | 6746 6747 6748 6749 6750 6751 6752 6753 6754 6755 6756 6757 6758 6759 6760 | ** If the isCommit flag is set, there is no need to remember that ** the journal needs to be sync()ed before database page pPg->pgno ** can be written to. The caller has already promised not to write to it. */ if( (pPg->flags&PGHDR_NEED_SYNC) && !isCommit ){ needSyncPgno = pPg->pgno; assert( pPager->journalMode==PAGER_JOURNALMODE_OFF || pageInJournal(pPager, pPg) || pPg->pgno>pPager->dbOrigSize ); assert( pPg->flags&PGHDR_DIRTY ); } /* If the cache contains a page with page-number pgno, remove it ** from its hash chain. Also, if the PGHDR_NEED_SYNC flag was set for ** page pgno before the 'move' operation, it needs to be retained ** for the page moved there. |
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