Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
Comment: | Make the sqlite3BtreeMoveto routine a no-op if the cursor is already pointing at the cell we are trying to move to. (CVS 4938) |
---|---|
Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
9b567ab61e7542141b7bc9c3c053c2d1 |
User & Date: | drh 2008-03-29 16:01:04.000 |
Context
2008-03-29
| ||
17:26 | Set exclusive locking mode by default on the speed4p test. (CVS 4939) (check-in: 2d9fea9533 user: drh tags: trunk) | |
16:01 | Make the sqlite3BtreeMoveto routine a no-op if the cursor is already pointing at the cell we are trying to move to. (CVS 4938) (check-in: 9b567ab61e user: drh tags: trunk) | |
12:50 | add two missing initializer values (CVS 4937) (check-in: bf28f1c260 user: rse tags: trunk) | |
Changes
Changes to src/btree.c.
1 2 3 4 5 6 7 8 9 10 11 | /* ** 2004 April 6 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* | | | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | /* ** 2004 April 6 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** $Id: btree.c,v 1.448 2008/03/29 16:01:04 drh Exp $ ** ** This file implements a external (disk-based) database using BTrees. ** See the header comment on "btreeInt.h" for additional information. ** Including a description of file format and an overview of operation. */ #include "btreeInt.h" |
︙ | ︙ | |||
2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 | #define assertCellInfo(x) #endif #ifdef _MSC_VER /* Use a real function in MSVC to work around bugs in that compiler. */ static void getCellInfo(BtCursor *pCur){ if( pCur->info.nSize==0 ){ sqlite3BtreeParseCell(pCur->pPage, pCur->idx, &pCur->info); }else{ assertCellInfo(pCur); } } #else /* if not _MSC_VER */ /* Use a macro in all other compilers so that the function is inlined */ #define getCellInfo(pCur) \ if( pCur->info.nSize==0 ){ \ sqlite3BtreeParseCell(pCur->pPage, pCur->idx, &pCur->info); \ }else{ \ assertCellInfo(pCur); \ } #endif /* _MSC_VER */ /* ** Set *pSize to the size of the buffer needed to hold the value of | > > | 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 | #define assertCellInfo(x) #endif #ifdef _MSC_VER /* Use a real function in MSVC to work around bugs in that compiler. */ static void getCellInfo(BtCursor *pCur){ if( pCur->info.nSize==0 ){ sqlite3BtreeParseCell(pCur->pPage, pCur->idx, &pCur->info); pCur->validNKey = 1; }else{ assertCellInfo(pCur); } } #else /* if not _MSC_VER */ /* Use a macro in all other compilers so that the function is inlined */ #define getCellInfo(pCur) \ if( pCur->info.nSize==0 ){ \ sqlite3BtreeParseCell(pCur->pPage, pCur->idx, &pCur->info); \ pCur->validNKey = 1; \ }else{ \ assertCellInfo(pCur); \ } #endif /* _MSC_VER */ /* ** Set *pSize to the size of the buffer needed to hold the value of |
︙ | ︙ | |||
3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 | pNewPage->idxParent = pCur->idx; pOldPage = pCur->pPage; pOldPage->idxShift = 0; releasePage(pOldPage); pCur->pPage = pNewPage; pCur->idx = 0; pCur->info.nSize = 0; if( pNewPage->nCell<1 ){ return SQLITE_CORRUPT_BKPT; } return SQLITE_OK; } /* | > | 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 | pNewPage->idxParent = pCur->idx; pOldPage = pCur->pPage; pOldPage->idxShift = 0; releasePage(pOldPage); pCur->pPage = pNewPage; pCur->idx = 0; pCur->info.nSize = 0; pCur->validNKey = 0; if( pNewPage->nCell<1 ){ return SQLITE_CORRUPT_BKPT; } return SQLITE_OK; } /* |
︙ | ︙ | |||
3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 | pParent = pPage->pParent; assert( pParent!=0 ); idxParent = pPage->idxParent; sqlite3PagerRef(pParent->pDbPage); releasePage(pPage); pCur->pPage = pParent; pCur->info.nSize = 0; assert( pParent->idxShift==0 ); pCur->idx = idxParent; } /* ** Move the cursor to the root page */ | > | 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 | pParent = pPage->pParent; assert( pParent!=0 ); idxParent = pPage->idxParent; sqlite3PagerRef(pParent->pDbPage); releasePage(pPage); pCur->pPage = pParent; pCur->info.nSize = 0; pCur->validNKey = 0; assert( pParent->idxShift==0 ); pCur->idx = idxParent; } /* ** Move the cursor to the root page */ |
︙ | ︙ | |||
3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 | return rc; } releasePage(pCur->pPage); pCur->pPage = pRoot; } pCur->idx = 0; pCur->info.nSize = 0; if( pRoot->nCell==0 && !pRoot->leaf ){ Pgno subpage; assert( pRoot->pgno==1 ); subpage = get4byte(&pRoot->aData[pRoot->hdrOffset+8]); assert( subpage>0 ); pCur->eState = CURSOR_VALID; rc = moveToChild(pCur, subpage); | > > | 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 | return rc; } releasePage(pCur->pPage); pCur->pPage = pRoot; } pCur->idx = 0; pCur->info.nSize = 0; pCur->atLast = 0; pCur->validNKey = 0; if( pRoot->nCell==0 && !pRoot->leaf ){ Pgno subpage; assert( pRoot->pgno==1 ); subpage = get4byte(&pRoot->aData[pRoot->hdrOffset+8]); assert( subpage>0 ); pCur->eState = CURSOR_VALID; rc = moveToChild(pCur, subpage); |
︙ | ︙ | |||
3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 | pgno = get4byte(&pPage->aData[pPage->hdrOffset+8]); pCur->idx = pPage->nCell; rc = moveToChild(pCur, pgno); } if( rc==SQLITE_OK ){ pCur->idx = pPage->nCell - 1; pCur->info.nSize = 0; } return SQLITE_OK; } /* Move the cursor to the first entry in the table. Return SQLITE_OK ** on success. Set *pRes to 0 if the cursor actually points to something ** or set *pRes to 1 if the table is empty. | > | 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 | pgno = get4byte(&pPage->aData[pPage->hdrOffset+8]); pCur->idx = pPage->nCell; rc = moveToChild(pCur, pgno); } if( rc==SQLITE_OK ){ pCur->idx = pPage->nCell - 1; pCur->info.nSize = 0; pCur->validNKey = 0; } return SQLITE_OK; } /* Move the cursor to the first entry in the table. Return SQLITE_OK ** on success. Set *pRes to 0 if the cursor actually points to something ** or set *pRes to 1 if the table is empty. |
︙ | ︙ | |||
3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 | if( CURSOR_INVALID==pCur->eState ){ assert( pCur->pPage->nCell==0 ); *pRes = 1; }else{ assert( pCur->eState==CURSOR_VALID ); *pRes = 0; rc = moveToRightmost(pCur); } } return rc; } /* Move the cursor so that it points to an entry near the key ** specified by pKey/nKey/pUnKey. Return a success code. | > > | 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 | if( CURSOR_INVALID==pCur->eState ){ assert( pCur->pPage->nCell==0 ); *pRes = 1; }else{ assert( pCur->eState==CURSOR_VALID ); *pRes = 0; rc = moveToRightmost(pCur); getCellInfo(pCur); pCur->atLast = rc==SQLITE_OK; } } return rc; } /* Move the cursor so that it points to an entry near the key ** specified by pKey/nKey/pUnKey. Return a success code. |
︙ | ︙ | |||
3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 | int *pRes /* Search result flag */ ){ int rc; char aSpace[200]; assert( cursorHoldsMutex(pCur) ); assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) ); rc = moveToRoot(pCur); if( rc ){ return rc; } assert( pCur->pPage ); assert( pCur->pPage->isInit ); if( pCur->eState==CURSOR_INVALID ){ | > > > > > > > > > > > > > > > | 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 | int *pRes /* Search result flag */ ){ int rc; char aSpace[200]; assert( cursorHoldsMutex(pCur) ); assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) ); /* If the cursor is already positioned at the point we are trying ** to move to, then just return without doing any work */ if( pCur->eState==CURSOR_VALID && pCur->validNKey && pCur->pPage->intKey ){ if( pCur->info.nKey==nKey ){ *pRes = 0; return SQLITE_OK; } if( pCur->atLast && pCur->info.nKey<nKey ){ *pRes = -1; return SQLITE_OK; } } rc = moveToRoot(pCur); if( rc ){ return rc; } assert( pCur->pPage ); assert( pCur->pPage->isInit ); if( pCur->eState==CURSOR_INVALID ){ |
︙ | ︙ | |||
3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 | }else{ pCur->idx = (upr+lwr)/2; } if( lwr<=upr ) for(;;){ void *pCellKey; i64 nCellKey; pCur->info.nSize = 0; if( pPage->intKey ){ u8 *pCell; pCell = findCell(pPage, pCur->idx) + pPage->childPtrSize; if( pPage->hasData ){ u32 dummy; pCell += getVarint32(pCell, &dummy); } | > | | 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 | }else{ pCur->idx = (upr+lwr)/2; } if( lwr<=upr ) for(;;){ void *pCellKey; i64 nCellKey; pCur->info.nSize = 0; pCur->validNKey = 1; if( pPage->intKey ){ u8 *pCell; pCell = findCell(pPage, pCur->idx) + pPage->childPtrSize; if( pPage->hasData ){ u32 dummy; pCell += getVarint32(pCell, &dummy); } getVarint(pCell, (u64*)&nCellKey); if( nCellKey<nKey ){ c = -1; }else if( nCellKey>nKey ){ c = +1; }else{ c = 0; } |
︙ | ︙ | |||
3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691 3692 3693 3694 3695 3696 3697 | rc = sqlite3BtreeKey(pCur, 0, nCellKey, (void *)pCellKey); c = sqlite3VdbeRecordCompare(nCellKey, pCellKey, pUnKey); sqlite3_free(pCellKey); if( rc ) goto moveto_finish; } } if( c==0 ){ if( pPage->leafData && !pPage->leaf ){ lwr = pCur->idx; upr = lwr - 1; break; }else{ if( pRes ) *pRes = 0; rc = SQLITE_OK; goto moveto_finish; } } if( c<0 ){ lwr = pCur->idx+1; }else{ upr = pCur->idx-1; } if( lwr>upr ){ break; } pCur->idx = (lwr+upr)/2; } assert( lwr==upr+1 ); assert( pPage->isInit ); if( pPage->leaf ){ | > > | 3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720 3721 3722 3723 3724 | rc = sqlite3BtreeKey(pCur, 0, nCellKey, (void *)pCellKey); c = sqlite3VdbeRecordCompare(nCellKey, pCellKey, pUnKey); sqlite3_free(pCellKey); if( rc ) goto moveto_finish; } } if( c==0 ){ pCur->info.nKey = nCellKey; if( pPage->leafData && !pPage->leaf ){ lwr = pCur->idx; upr = lwr - 1; break; }else{ if( pRes ) *pRes = 0; rc = SQLITE_OK; goto moveto_finish; } } if( c<0 ){ lwr = pCur->idx+1; }else{ upr = pCur->idx-1; } if( lwr>upr ){ pCur->info.nKey = nCellKey; break; } pCur->idx = (lwr+upr)/2; } assert( lwr==upr+1 ); assert( pPage->isInit ); if( pPage->leaf ){ |
︙ | ︙ | |||
3705 3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 | assert( pCur->idx>=0 && pCur->idx<pCur->pPage->nCell ); if( pRes ) *pRes = c; rc = SQLITE_OK; goto moveto_finish; } pCur->idx = lwr; pCur->info.nSize = 0; rc = moveToChild(pCur, chldPg); if( rc ) goto moveto_finish; } moveto_finish: if( pKey ){ /* If we created our own unpacked key at the top of this ** procedure, then destroy that key before returning. */ | > | 3732 3733 3734 3735 3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746 | assert( pCur->idx>=0 && pCur->idx<pCur->pPage->nCell ); if( pRes ) *pRes = c; rc = SQLITE_OK; goto moveto_finish; } pCur->idx = lwr; pCur->info.nSize = 0; pCur->validNKey = 0; rc = moveToChild(pCur, chldPg); if( rc ) goto moveto_finish; } moveto_finish: if( pKey ){ /* If we created our own unpacked key at the top of this ** procedure, then destroy that key before returning. */ |
︙ | ︙ | |||
3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 | pCur->skip = 0; assert( pPage->isInit ); assert( pCur->idx<pPage->nCell ); pCur->idx++; pCur->info.nSize = 0; if( pCur->idx>=pPage->nCell ){ if( !pPage->leaf ){ rc = moveToChild(pCur, get4byte(&pPage->aData[pPage->hdrOffset+8])); if( rc ) return rc; rc = moveToLeftmost(pCur); *pRes = 0; return rc; | > | 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 | pCur->skip = 0; assert( pPage->isInit ); assert( pCur->idx<pPage->nCell ); pCur->idx++; pCur->info.nSize = 0; pCur->validNKey = 0; if( pCur->idx>=pPage->nCell ){ if( !pPage->leaf ){ rc = moveToChild(pCur, get4byte(&pPage->aData[pPage->hdrOffset+8])); if( rc ) return rc; rc = moveToLeftmost(pCur); *pRes = 0; return rc; |
︙ | ︙ | |||
3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 | MemPage *pPage; assert( cursorHoldsMutex(pCur) ); rc = restoreOrClearCursorPosition(pCur); if( rc!=SQLITE_OK ){ return rc; } if( CURSOR_INVALID==pCur->eState ){ *pRes = 1; return SQLITE_OK; } if( pCur->skip<0 ){ pCur->skip = 0; *pRes = 0; | > | 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 | MemPage *pPage; assert( cursorHoldsMutex(pCur) ); rc = restoreOrClearCursorPosition(pCur); if( rc!=SQLITE_OK ){ return rc; } pCur->atLast = 0; if( CURSOR_INVALID==pCur->eState ){ *pRes = 1; return SQLITE_OK; } if( pCur->skip<0 ){ pCur->skip = 0; *pRes = 0; |
︙ | ︙ | |||
3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 | return SQLITE_OK; } sqlite3BtreeMoveToParent(pCur); pPage = pCur->pPage; } pCur->idx--; pCur->info.nSize = 0; if( pPage->leafData && !pPage->leaf ){ rc = sqlite3BtreePrevious(pCur, pRes); }else{ rc = SQLITE_OK; } } *pRes = 0; | > | 3893 3894 3895 3896 3897 3898 3899 3900 3901 3902 3903 3904 3905 3906 3907 | return SQLITE_OK; } sqlite3BtreeMoveToParent(pCur); pPage = pCur->pPage; } pCur->idx--; pCur->info.nSize = 0; pCur->validNKey = 0; if( pPage->leafData && !pPage->leaf ){ rc = sqlite3BtreePrevious(pCur, pRes); }else{ rc = SQLITE_OK; } } *pRes = 0; |
︙ | ︙ | |||
5669 5670 5671 5672 5673 5674 5675 5676 5677 5678 5679 5680 5681 5682 | rc = clearCell(pPage, oldCell); if( rc ) goto end_insert; dropCell(pPage, pCur->idx, szOld); }else if( loc<0 && pPage->nCell>0 ){ assert( pPage->leaf ); pCur->idx++; pCur->info.nSize = 0; }else{ assert( pPage->leaf ); } rc = insertCell(pPage, pCur->idx, newCell, szNew, 0, 0); if( rc!=SQLITE_OK ) goto end_insert; rc = balance(pPage, 1); /* sqlite3BtreePageDump(pCur->pBt, pCur->pgnoRoot, 1); */ | > | 5700 5701 5702 5703 5704 5705 5706 5707 5708 5709 5710 5711 5712 5713 5714 | rc = clearCell(pPage, oldCell); if( rc ) goto end_insert; dropCell(pPage, pCur->idx, szOld); }else if( loc<0 && pPage->nCell>0 ){ assert( pPage->leaf ); pCur->idx++; pCur->info.nSize = 0; pCur->validNKey = 0; }else{ assert( pPage->leaf ); } rc = insertCell(pPage, pCur->idx, newCell, szNew, 0, 0); if( rc!=SQLITE_OK ) goto end_insert; rc = balance(pPage, 1); /* sqlite3BtreePageDump(pCur->pBt, pCur->pgnoRoot, 1); */ |
︙ | ︙ |
Changes to src/btreeInt.h.
1 2 3 4 5 6 7 8 9 10 11 | /* ** 2004 April 6 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* | | | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | /* ** 2004 April 6 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** $Id: btreeInt.h,v 1.20 2008/03/29 16:01:04 drh Exp $ ** ** This file implements a external (disk-based) database using BTrees. ** For a detailed discussion of BTrees, refer to ** ** Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3: ** "Sorting And Searching", pages 473-480. Addison-Wesley ** Publishing Company, Reading, Massachusetts. |
︙ | ︙ | |||
438 439 440 441 442 443 444 445 446 447 448 449 450 451 | BtCursor *pNext, *pPrev; /* Forms a linked list of all cursors */ struct KeyInfo *pKeyInfo; /* Argument passed to comparison function */ Pgno pgnoRoot; /* The root page of this tree */ MemPage *pPage; /* Page that contains the entry */ int idx; /* Index of the entry in pPage->aCell[] */ CellInfo info; /* A parse of the cell we are pointing at */ u8 wrFlag; /* True if writable */ u8 eState; /* One of the CURSOR_XXX constants (see below) */ void *pKey; /* Saved key that was cursor's last known position */ i64 nKey; /* Size of pKey, or last integer key */ int skip; /* (skip<0) -> Prev() is a no-op. (skip>0) -> Next() is */ #ifndef SQLITE_OMIT_INCRBLOB u8 isIncrblobHandle; /* True if this cursor is an incr. io handle */ Pgno *aOverflow; /* Cache of overflow page locations */ | > > | 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 | BtCursor *pNext, *pPrev; /* Forms a linked list of all cursors */ struct KeyInfo *pKeyInfo; /* Argument passed to comparison function */ Pgno pgnoRoot; /* The root page of this tree */ MemPage *pPage; /* Page that contains the entry */ int idx; /* Index of the entry in pPage->aCell[] */ CellInfo info; /* A parse of the cell we are pointing at */ u8 wrFlag; /* True if writable */ u8 atLast; /* Cursor pointing to the last entry */ u8 validNKey; /* True if info.nKey is valid */ u8 eState; /* One of the CURSOR_XXX constants (see below) */ void *pKey; /* Saved key that was cursor's last known position */ i64 nKey; /* Size of pKey, or last integer key */ int skip; /* (skip<0) -> Prev() is a no-op. (skip>0) -> Next() is */ #ifndef SQLITE_OMIT_INCRBLOB u8 isIncrblobHandle; /* True if this cursor is an incr. io handle */ Pgno *aOverflow; /* Cache of overflow page locations */ |
︙ | ︙ |