diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/btree.c | 43 |
1 files changed, 17 insertions, 26 deletions
diff --git a/src/btree.c b/src/btree.c index e4a7aa160..2575c774c 100644 --- a/src/btree.c +++ b/src/btree.c @@ -4424,7 +4424,6 @@ static int copyPayload( ** ** 0: The operation is a read. Populate the overflow cache. ** 1: The operation is a write. Populate the overflow cache. -** 2: The operation is a read. Do not populate the overflow cache. ** ** A total of "amt" bytes are read or written beginning at "offset". ** Data is read to or from the buffer pBuf. @@ -4432,13 +4431,13 @@ static int copyPayload( ** The content being read or written might appear on the main page ** or be scattered out on multiple overflow pages. ** -** If the current cursor entry uses one or more overflow pages and the -** eOp argument is not 2, this function may allocate space for and lazily -** populates the overflow page-list cache array (BtCursor.aOverflow). +** If the current cursor entry uses one or more overflow pages +** this function may allocate space for and lazily populate +** the overflow page-list cache array (BtCursor.aOverflow). ** Subsequent calls use this cache to make seeking to the supplied offset ** more efficient. ** -** Once an overflow page-list cache has been allocated, it may be +** Once an overflow page-list cache has been allocated, it must be ** invalidated if some other cursor writes to the same table, or if ** the cursor is moved to a different row. Additionally, in auto-vacuum ** mode, the following events may invalidate an overflow page-list cache. @@ -4464,10 +4463,10 @@ static int accessPayload( #endif assert( pPage ); + assert( eOp==0 || eOp==1 ); assert( pCur->eState==CURSOR_VALID ); assert( pCur->aiIdx[pCur->iPage]<pPage->nCell ); assert( cursorHoldsMutex(pCur) ); - assert( eOp!=2 || offset==0 ); /* Always start from beginning for eOp==2 */ getCellInfo(pCur); aPayload = pCur->info.pPayload; @@ -4489,7 +4488,7 @@ static int accessPayload( if( a+offset>pCur->info.nLocal ){ a = pCur->info.nLocal - offset; } - rc = copyPayload(&aPayload[offset], pBuf, a, (eOp & 0x01), pPage->pDbPage); + rc = copyPayload(&aPayload[offset], pBuf, a, eOp, pPage->pDbPage); offset = 0; pBuf += a; amt -= a; @@ -4505,14 +4504,13 @@ static int accessPayload( nextPage = get4byte(&aPayload[pCur->info.nLocal]); /* If the BtCursor.aOverflow[] has not been allocated, allocate it now. - ** Except, do not allocate aOverflow[] for eOp==2. ** ** The aOverflow[] array is sized at one entry for each overflow page ** in the overflow chain. The page number of the first overflow page is ** stored in aOverflow[0], etc. A value of 0 in the aOverflow[] array ** means "not yet known" (the cache is lazily populated). */ - if( eOp!=2 && (pCur->curFlags & BTCF_ValidOvfl)==0 ){ + if( (pCur->curFlags & BTCF_ValidOvfl)==0 ){ int nOvfl = (pCur->info.nPayload-pCur->info.nLocal+ovflSize-1)/ovflSize; if( nOvfl>pCur->nOvflAlloc ){ Pgno *aNew = (Pgno*)sqlite3Realloc( @@ -4533,9 +4531,7 @@ static int accessPayload( ** entry for the first required overflow page is valid, skip ** directly to it. */ - if( (pCur->curFlags & BTCF_ValidOvfl)!=0 - && pCur->aOverflow[offset/ovflSize] - ){ + if( pCur->aOverflow[offset/ovflSize] ){ iIdx = (offset/ovflSize); nextPage = pCur->aOverflow[iIdx]; offset = (offset%ovflSize); @@ -4544,12 +4540,10 @@ static int accessPayload( assert( rc==SQLITE_OK && amt>0 ); while( nextPage ){ /* If required, populate the overflow page-list cache. */ - if( (pCur->curFlags & BTCF_ValidOvfl)!=0 ){ - assert( pCur->aOverflow[iIdx]==0 - || pCur->aOverflow[iIdx]==nextPage - || CORRUPT_DB ); - pCur->aOverflow[iIdx] = nextPage; - } + assert( pCur->aOverflow[iIdx]==0 + || pCur->aOverflow[iIdx]==nextPage + || CORRUPT_DB ); + pCur->aOverflow[iIdx] = nextPage; if( offset>=ovflSize ){ /* The only reason to read this page is to obtain the page @@ -4557,11 +4551,7 @@ static int accessPayload( ** data is not required. So first try to lookup the overflow ** page-list cache, if any, then fall back to the getOverflowPage() ** function. - ** - ** Note that the aOverflow[] array must be allocated because eOp!=2 - ** here. If eOp==2, then offset==0 and this branch is never taken. */ - assert( eOp!=2 ); assert( pCur->curFlags & BTCF_ValidOvfl ); assert( pCur->pBtree->db==pBt->db ); if( pCur->aOverflow[iIdx+1] ){ @@ -4596,7 +4586,7 @@ static int accessPayload( ** output buffer, bypassing the page-cache altogether. This speeds ** up loading large records that span many overflow pages. */ - if( (eOp&0x01)==0 /* (1) */ + if( eOp==0 /* (1) */ && offset==0 /* (2) */ && pBt->inTransaction==TRANS_READ /* (3) */ && (fd = sqlite3PagerFile(pBt->pPager))->pMethods /* (4) */ @@ -4616,12 +4606,12 @@ static int accessPayload( { DbPage *pDbPage; rc = sqlite3PagerGet(pBt->pPager, nextPage, &pDbPage, - ((eOp&0x01)==0 ? PAGER_GET_READONLY : 0) + (eOp==0 ? PAGER_GET_READONLY : 0) ); if( rc==SQLITE_OK ){ aPayload = sqlite3PagerGetData(pDbPage); nextPage = get4byte(aPayload); - rc = copyPayload(&aPayload[offset+4], pBuf, a, (eOp&0x01), pDbPage); + rc = copyPayload(&aPayload[offset+4], pBuf, a, eOp, pDbPage); sqlite3PagerUnref(pDbPage); offset = 0; } @@ -5253,7 +5243,8 @@ int sqlite3BtreeMovetoUnpacked( goto moveto_finish; } pCur->aiIdx[pCur->iPage] = (u16)idx; - rc = accessPayload(pCur, 0, nCell, (unsigned char*)pCellKey, 2); + rc = accessPayload(pCur, 0, nCell, (unsigned char*)pCellKey, 0); + pCur->curFlags &= ~BTCF_ValidOvfl; if( rc ){ sqlite3_free(pCellKey); goto moveto_finish; |