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Overview
Comment: | Add the MemPage.xParseCell method and provide various implementations (variations on the former btreeParseCellPtr()) depending on the page type. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
41d03d883c4f7ca279eb9dd679f3ab81 |
User & Date: | drh 2015-06-19 17:19:34.228 |
Context
2015-06-19
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20:31 | Performance improvements in btreeParseCell() by inlining the varint decoder. (check-in: 172a864d14 user: drh tags: trunk) | |
18:24 | Performance improvements in btreeParseCell() by inlining the varint decoder. (check-in: faab0ed928 user: drh tags: btree-opt) | |
17:19 | Add the MemPage.xParseCell method and provide various implementations (variations on the former btreeParseCellPtr()) depending on the page type. (check-in: 41d03d883c user: drh tags: trunk) | |
15:07 | Make cellSizePtr() a method on the MemPage object, with alternative implementations depending on the page type. This results is a small performance improvement and size reduction. (check-in: 02f7e9d7d7 user: drh tags: trunk) | |
Changes
Changes to src/btree.c.
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976 977 978 979 980 981 982 | iCell--; } } return findCell(pPage, iCell); } /* | > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | > | > | > > > | > > > > > > > > > > > > > > > > > > | | | | > | > > | > > > | | | < < > > > > > > > > > > > > > > > | > | > | > > > > > < < < < < < < < < < < < | < < < < < < < < < < < < | > > > < < | < > | | 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 | iCell--; } } return findCell(pPage, iCell); } /* ** This is common tail processing for btreeParseCellPtr() and ** btreeParseCellPtrIndex() for the case when the cell does not fit entirely ** on a single B-tree page. Make necessary adjustments to the CellInfo ** structure. */ static SQLITE_NOINLINE void btreeParseCellAdjustSizeForOverflow( MemPage *pPage, /* Page containing the cell */ u8 *pCell, /* Pointer to the cell text. */ CellInfo *pInfo /* Fill in this structure */ ){ /* If the payload will not fit completely on the local page, we have ** to decide how much to store locally and how much to spill onto ** overflow pages. The strategy is to minimize the amount of unused ** space on overflow pages while keeping the amount of local storage ** in between minLocal and maxLocal. ** ** Warning: changing the way overflow payload is distributed in any ** way will result in an incompatible file format. */ int minLocal; /* Minimum amount of payload held locally */ int maxLocal; /* Maximum amount of payload held locally */ int surplus; /* Overflow payload available for local storage */ minLocal = pPage->minLocal; maxLocal = pPage->maxLocal; surplus = minLocal + (pInfo->nPayload - minLocal)%(pPage->pBt->usableSize-4); testcase( surplus==maxLocal ); testcase( surplus==maxLocal+1 ); if( surplus <= maxLocal ){ pInfo->nLocal = (u16)surplus; }else{ pInfo->nLocal = (u16)minLocal; } pInfo->iOverflow = (u16)(&pInfo->pPayload[pInfo->nLocal] - pCell); pInfo->nSize = pInfo->iOverflow + 4; } /* ** The following routines are implementations of the MemPage.xParseCell() ** method. ** ** Parse a cell content block and fill in the CellInfo structure. ** ** btreeParseCellPtr() => table btree leaf nodes ** btreeParseCellNoPayload() => table btree internal nodes ** btreeParseCellPtrIndex() => index btree nodes ** ** There is also a wrapper function btreeParseCell() that works for ** all MemPage types and that references the cell by index rather than ** by pointer. */ static void btreeParseCellPtrNoPayload( MemPage *pPage, /* Page containing the cell */ u8 *pCell, /* Pointer to the cell text. */ CellInfo *pInfo /* Fill in this structure */ ){ assert( sqlite3_mutex_held(pPage->pBt->mutex) ); assert( pPage->leaf==0 ); assert( pPage->noPayload ); assert( pPage->childPtrSize==4 ); pInfo->nSize = 4 + getVarint(&pCell[4], (u64*)&pInfo->nKey); pInfo->nPayload = 0; pInfo->nLocal = 0; pInfo->iOverflow = 0; pInfo->pPayload = 0; return; } static void btreeParseCellPtr( MemPage *pPage, /* Page containing the cell */ u8 *pCell, /* Pointer to the cell text. */ CellInfo *pInfo /* Fill in this structure */ ){ u8 *pIter; /* For scanning through pCell */ u32 nPayload; /* Number of bytes of cell payload */ assert( sqlite3_mutex_held(pPage->pBt->mutex) ); assert( pPage->leaf==0 || pPage->leaf==1 ); assert( pPage->intKeyLeaf || pPage->noPayload ); assert( pPage->noPayload==0 ); assert( pPage->intKeyLeaf ); assert( pPage->childPtrSize==0 ); pIter = pCell + getVarint32(pCell, nPayload); pIter += getVarint(pIter, (u64*)&pInfo->nKey); pInfo->nPayload = nPayload; pInfo->pPayload = pIter; testcase( nPayload==pPage->maxLocal ); testcase( nPayload==pPage->maxLocal+1 ); if( nPayload<=pPage->maxLocal ){ /* This is the (easy) common case where the entire payload fits ** on the local page. No overflow is required. */ pInfo->nSize = nPayload + (u16)(pIter - pCell); if( pInfo->nSize<4 ) pInfo->nSize = 4; pInfo->nLocal = (u16)nPayload; pInfo->iOverflow = 0; }else{ btreeParseCellAdjustSizeForOverflow(pPage, pCell, pInfo); } } static void btreeParseCellPtrIndex( MemPage *pPage, /* Page containing the cell */ u8 *pCell, /* Pointer to the cell text. */ CellInfo *pInfo /* Fill in this structure */ ){ u8 *pIter; /* For scanning through pCell */ u32 nPayload; /* Number of bytes of cell payload */ assert( sqlite3_mutex_held(pPage->pBt->mutex) ); assert( pPage->leaf==0 || pPage->leaf==1 ); assert( pPage->intKeyLeaf==0 ); assert( pPage->noPayload==0 ); pIter = pCell + pPage->childPtrSize; nPayload = *pIter; if( nPayload>=0x80 ){ u8 *pEnd = &pIter[9]; nPayload &= 0x7f; do{ nPayload = (nPayload<<7) | (*++pIter & 0x7f); }while( *(pIter)>=0x80 && pIter<pEnd ); } pIter++; pInfo->nKey = nPayload; pInfo->nPayload = nPayload; pInfo->pPayload = pIter; testcase( nPayload==pPage->maxLocal ); testcase( nPayload==pPage->maxLocal+1 ); if( nPayload<=pPage->maxLocal ){ /* This is the (easy) common case where the entire payload fits ** on the local page. No overflow is required. */ pInfo->nSize = nPayload + (u16)(pIter - pCell); if( pInfo->nSize<4 ) pInfo->nSize = 4; pInfo->nLocal = (u16)nPayload; pInfo->iOverflow = 0; }else{ btreeParseCellAdjustSizeForOverflow(pPage, pCell, pInfo); } } static void btreeParseCell( MemPage *pPage, /* Page containing the cell */ int iCell, /* The cell index. First cell is 0 */ CellInfo *pInfo /* Fill in this structure */ ){ pPage->xParseCell(pPage, findCell(pPage, iCell), pInfo); } /* ** The following routines are implementations of the MemPage.xCellSize ** method. ** ** Compute the total number of bytes that a Cell needs in the cell ** data area of the btree-page. The return number includes the cell ** data header and the local payload, but not any overflow page or ** the space used by the cell pointer. ** ** cellSizePtrNoPayload() => table internal nodes ** cellSizePtr() => all index nodes & table leaf nodes */ static u16 cellSizePtr(MemPage *pPage, u8 *pCell){ u8 *pIter = pCell + pPage->childPtrSize; /* For looping over bytes of pCell */ u8 *pEnd; /* End mark for a varint */ u32 nSize; /* Size value to return */ #ifdef SQLITE_DEBUG /* The value returned by this function should always be the same as ** the (CellInfo.nSize) value found by doing a full parse of the ** cell. If SQLITE_DEBUG is defined, an assert() at the bottom of ** this function verifies that this invariant is not violated. */ CellInfo debuginfo; pPage->xParseCell(pPage, pCell, &debuginfo); #endif assert( pPage->noPayload==0 ); nSize = *pIter; if( nSize>=0x80 ){ pEnd = &pIter[9]; nSize &= 0x7f; |
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1126 1127 1128 1129 1130 1131 1132 | #ifdef SQLITE_DEBUG /* The value returned by this function should always be the same as ** the (CellInfo.nSize) value found by doing a full parse of the ** cell. If SQLITE_DEBUG is defined, an assert() at the bottom of ** this function verifies that this invariant is not violated. */ CellInfo debuginfo; | | | 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 | #ifdef SQLITE_DEBUG /* The value returned by this function should always be the same as ** the (CellInfo.nSize) value found by doing a full parse of the ** cell. If SQLITE_DEBUG is defined, an assert() at the bottom of ** this function verifies that this invariant is not violated. */ CellInfo debuginfo; pPage->xParseCell(pPage, pCell, &debuginfo); #endif assert( pPage->childPtrSize==4 ); pEnd = pIter + 9; while( (*pIter++)&0x80 && pIter<pEnd ); assert( debuginfo.nSize==(u16)(pIter - pCell) || CORRUPT_DB ); return (u16)(pIter - pCell); |
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1155 1156 1157 1158 1159 1160 1161 | ** to an overflow page, insert an entry into the pointer-map ** for the overflow page. */ static void ptrmapPutOvflPtr(MemPage *pPage, u8 *pCell, int *pRC){ CellInfo info; if( *pRC ) return; assert( pCell!=0 ); | | | 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 | ** to an overflow page, insert an entry into the pointer-map ** for the overflow page. */ static void ptrmapPutOvflPtr(MemPage *pPage, u8 *pCell, int *pRC){ CellInfo info; if( *pRC ) return; assert( pCell!=0 ); pPage->xParseCell(pPage, pCell, &info); if( info.iOverflow ){ Pgno ovfl = get4byte(&pCell[info.iOverflow]); ptrmapPut(pPage->pBt, ovfl, PTRMAP_OVERFLOW1, pPage->pgno, pRC); } } #endif |
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1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 | /* EVIDENCE-OF: R-20501-61796 A value of 13 means the page is a leaf ** table b-tree page. */ assert( (PTF_LEAFDATA|PTF_INTKEY|PTF_LEAF)==13 ); pPage->intKey = 1; if( pPage->leaf ){ pPage->intKeyLeaf = 1; pPage->noPayload = 0; }else{ pPage->intKeyLeaf = 0; pPage->noPayload = 1; pPage->xCellSize = cellSizePtrNoPayload; } pPage->maxLocal = pBt->maxLeaf; pPage->minLocal = pBt->minLeaf; }else if( flagByte==PTF_ZERODATA ){ /* EVIDENCE-OF: R-27225-53936 A value of 2 means the page is an interior ** index b-tree page. */ assert( (PTF_ZERODATA)==2 ); /* EVIDENCE-OF: R-16571-11615 A value of 10 means the page is a leaf ** index b-tree page. */ assert( (PTF_ZERODATA|PTF_LEAF)==10 ); pPage->intKey = 0; pPage->intKeyLeaf = 0; pPage->noPayload = 0; pPage->maxLocal = pBt->maxLocal; pPage->minLocal = pBt->minLocal; }else{ /* EVIDENCE-OF: R-47608-56469 Any other value for the b-tree page type is ** an error. */ return SQLITE_CORRUPT_BKPT; } | > > > | 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 | /* EVIDENCE-OF: R-20501-61796 A value of 13 means the page is a leaf ** table b-tree page. */ assert( (PTF_LEAFDATA|PTF_INTKEY|PTF_LEAF)==13 ); pPage->intKey = 1; if( pPage->leaf ){ pPage->intKeyLeaf = 1; pPage->noPayload = 0; pPage->xParseCell = btreeParseCellPtr; }else{ pPage->intKeyLeaf = 0; pPage->noPayload = 1; pPage->xCellSize = cellSizePtrNoPayload; pPage->xParseCell = btreeParseCellPtrNoPayload; } pPage->maxLocal = pBt->maxLeaf; pPage->minLocal = pBt->minLeaf; }else if( flagByte==PTF_ZERODATA ){ /* EVIDENCE-OF: R-27225-53936 A value of 2 means the page is an interior ** index b-tree page. */ assert( (PTF_ZERODATA)==2 ); /* EVIDENCE-OF: R-16571-11615 A value of 10 means the page is a leaf ** index b-tree page. */ assert( (PTF_ZERODATA|PTF_LEAF)==10 ); pPage->intKey = 0; pPage->intKeyLeaf = 0; pPage->noPayload = 0; pPage->xParseCell = btreeParseCellPtrIndex; pPage->maxLocal = pBt->maxLocal; pPage->minLocal = pBt->minLocal; }else{ /* EVIDENCE-OF: R-47608-56469 Any other value for the b-tree page type is ** an error. */ return SQLITE_CORRUPT_BKPT; } |
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3143 3144 3145 3146 3147 3148 3149 | if( rc ) return rc; nCell = pPage->nCell; for(i=0; i<nCell; i++){ u8 *pCell = findCell(pPage, i); if( eType==PTRMAP_OVERFLOW1 ){ CellInfo info; | | | 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 | if( rc ) return rc; nCell = pPage->nCell; for(i=0; i<nCell; i++){ u8 *pCell = findCell(pPage, i); if( eType==PTRMAP_OVERFLOW1 ){ CellInfo info; pPage->xParseCell(pPage, pCell, &info); if( info.iOverflow && pCell+info.iOverflow+3<=pPage->aData+pPage->maskPage && iFrom==get4byte(&pCell[info.iOverflow]) ){ put4byte(&pCell[info.iOverflow], iTo); break; } |
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4988 4989 4990 4991 4992 4993 4994 | ** ** If the record is corrupt, the xRecordCompare routine may read ** up to two varints past the end of the buffer. An extra 18 ** bytes of padding is allocated at the end of the buffer in ** case this happens. */ void *pCellKey; u8 * const pCellBody = pCell - pPage->childPtrSize; | | | 5058 5059 5060 5061 5062 5063 5064 5065 5066 5067 5068 5069 5070 5071 5072 | ** ** If the record is corrupt, the xRecordCompare routine may read ** up to two varints past the end of the buffer. An extra 18 ** bytes of padding is allocated at the end of the buffer in ** case this happens. */ void *pCellKey; u8 * const pCellBody = pCell - pPage->childPtrSize; pPage->xParseCell(pPage, pCellBody, &pCur->info); nCell = (int)pCur->info.nKey; testcase( nCell<0 ); /* True if key size is 2^32 or more */ testcase( nCell==0 ); /* Invalid key size: 0x80 0x80 0x00 */ testcase( nCell==1 ); /* Invalid key size: 0x80 0x80 0x01 */ testcase( nCell==2 ); /* Minimum legal index key size */ if( nCell<2 ){ rc = SQLITE_CORRUPT_BKPT; |
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5777 5778 5779 5780 5781 5782 5783 | CellInfo info; Pgno ovflPgno; int rc; int nOvfl; u32 ovflPageSize; assert( sqlite3_mutex_held(pPage->pBt->mutex) ); | | | 5847 5848 5849 5850 5851 5852 5853 5854 5855 5856 5857 5858 5859 5860 5861 | CellInfo info; Pgno ovflPgno; int rc; int nOvfl; u32 ovflPageSize; assert( sqlite3_mutex_held(pPage->pBt->mutex) ); pPage->xParseCell(pPage, pCell, &info); *pnSize = info.nSize; if( info.iOverflow==0 ){ return SQLITE_OK; /* No overflow pages. Return without doing anything */ } if( pCell+info.iOverflow+3 > pPage->aData+pPage->maskPage ){ return SQLITE_CORRUPT_BKPT; /* Cell extends past end of page */ } |
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5931 5932 5933 5934 5935 5936 5937 | ** ** Use a call to btreeParseCellPtr() to verify that the values above ** were computed correctly. */ #if SQLITE_DEBUG { CellInfo info; | | | 6001 6002 6003 6004 6005 6006 6007 6008 6009 6010 6011 6012 6013 6014 6015 | ** ** Use a call to btreeParseCellPtr() to verify that the values above ** were computed correctly. */ #if SQLITE_DEBUG { CellInfo info; pPage->xParseCell(pPage, pCell, &info); assert( nHeader=(int)(info.pPayload - pCell) ); assert( info.nKey==nKey ); assert( *pnSize == info.nSize ); assert( spaceLeft == info.nLocal ); assert( pPrior == &pCell[info.iOverflow] ); } #endif |
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6580 6581 6582 6583 6584 6585 6586 | assert( pPage->isInit ); for(j=0; j<pPage->nCell; j++){ CellInfo info; u8 *z; z = findCell(pPage, j); | | | 6650 6651 6652 6653 6654 6655 6656 6657 6658 6659 6660 6661 6662 6663 6664 | assert( pPage->isInit ); for(j=0; j<pPage->nCell; j++){ CellInfo info; u8 *z; z = findCell(pPage, j); pPage->xParseCell(pPage, z, &info); if( info.iOverflow ){ Pgno ovfl = get4byte(&z[info.iOverflow]); ptrmapGet(pBt, ovfl, &e, &n); assert( n==pPage->pgno && e==PTRMAP_OVERFLOW1 ); } if( !pPage->leaf ){ Pgno child = get4byte(z); |
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7211 7212 7213 7214 7215 7216 7217 | /* If the tree is a leaf-data tree, and the siblings are leaves, ** then there is no divider cell in apCell[]. Instead, the divider ** cell consists of the integer key for the right-most cell of ** the sibling-page assembled above only. */ CellInfo info; j--; | | | 7281 7282 7283 7284 7285 7286 7287 7288 7289 7290 7291 7292 7293 7294 7295 | /* If the tree is a leaf-data tree, and the siblings are leaves, ** then there is no divider cell in apCell[]. Instead, the divider ** cell consists of the integer key for the right-most cell of ** the sibling-page assembled above only. */ CellInfo info; j--; pNew->xParseCell(pNew, apCell[j], &info); pCell = pTemp; sz = 4 + putVarint(&pCell[4], info.nKey); pTemp = 0; }else{ pCell -= 4; /* Obscure case for non-leaf-data trees: If the cell at pCell was ** previously stored on a leaf node, and its reported size was 4 |
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8711 8712 8713 8714 8715 8716 8717 | /* Check payload overflow pages */ pCheck->zPfx = "On tree page %d cell %d: "; pCheck->v1 = iPage; pCheck->v2 = i; pCell = findCell(pPage,i); | | | 8781 8782 8783 8784 8785 8786 8787 8788 8789 8790 8791 8792 8793 8794 8795 | /* Check payload overflow pages */ pCheck->zPfx = "On tree page %d cell %d: "; pCheck->v1 = iPage; pCheck->v2 = i; pCell = findCell(pPage,i); pPage->xParseCell(pPage, pCell, &info); sz = info.nPayload; /* For intKey pages, check that the keys are in order. */ if( pPage->intKey ){ if( i==0 ){ nMinKey = nMaxKey = info.nKey; }else if( info.nKey <= nMaxKey ){ |
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Changes to src/btreeInt.h.
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227 228 229 230 231 232 233 234 235 236 237 238 239 240 | ** small cells will be rare, but they are possible. */ #define MX_CELL(pBt) ((pBt->pageSize-8)/6) /* Forward declarations */ typedef struct MemPage MemPage; typedef struct BtLock BtLock; /* ** This is a magic string that appears at the beginning of every ** SQLite database in order to identify the file as a real database. ** ** You can change this value at compile-time by specifying a ** -DSQLITE_FILE_HEADER="..." on the compiler command-line. The | > | 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 | ** small cells will be rare, but they are possible. */ #define MX_CELL(pBt) ((pBt->pageSize-8)/6) /* Forward declarations */ typedef struct MemPage MemPage; typedef struct BtLock BtLock; typedef struct CellInfo CellInfo; /* ** This is a magic string that appears at the beginning of every ** SQLite database in order to identify the file as a real database. ** ** You can change this value at compile-time by specifying a ** -DSQLITE_FILE_HEADER="..." on the compiler command-line. The |
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291 292 293 294 295 296 297 | ** non-overflow cell */ u8 *apOvfl[5]; /* Pointers to the body of overflow cells */ BtShared *pBt; /* Pointer to BtShared that this page is part of */ u8 *aData; /* Pointer to disk image of the page data */ u8 *aDataEnd; /* One byte past the end of usable data */ u8 *aCellIdx; /* The cell index area */ DbPage *pDbPage; /* Pager page handle */ | | > | 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 | ** non-overflow cell */ u8 *apOvfl[5]; /* Pointers to the body of overflow cells */ BtShared *pBt; /* Pointer to BtShared that this page is part of */ u8 *aData; /* Pointer to disk image of the page data */ u8 *aDataEnd; /* One byte past the end of usable data */ u8 *aCellIdx; /* The cell index area */ DbPage *pDbPage; /* Pager page handle */ u16 (*xCellSize)(MemPage*,u8*); /* cellSizePtr method */ void (*xParseCell)(MemPage*,u8*,CellInfo*); /* btreeParseCell method */ Pgno pgno; /* Page number for this page */ }; /* ** The in-memory image of a disk page has the auxiliary information appended ** to the end. EXTRA_SIZE is the number of bytes of space needed to hold ** that extra information. |
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457 458 459 460 461 462 463 | #define BTS_PENDING 0x0040 /* Waiting for read-locks to clear */ /* ** An instance of the following structure is used to hold information ** about a cell. The parseCellPtr() function fills in this structure ** based on information extract from the raw disk page. */ | < | 459 460 461 462 463 464 465 466 467 468 469 470 471 472 | #define BTS_PENDING 0x0040 /* Waiting for read-locks to clear */ /* ** An instance of the following structure is used to hold information ** about a cell. The parseCellPtr() function fills in this structure ** based on information extract from the raw disk page. */ struct CellInfo { i64 nKey; /* The key for INTKEY tables, or nPayload otherwise */ u8 *pPayload; /* Pointer to the start of payload */ u32 nPayload; /* Bytes of payload */ u16 nLocal; /* Amount of payload held locally, not on overflow */ u16 iOverflow; /* Offset to overflow page number. Zero if no overflow */ u16 nSize; /* Size of the cell content on the main b-tree page */ |
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