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Overview
Comment: | Add infrastructure to suport multiple btree implementations (CVS 894) |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
79b3aed2a74a67cbad631c4e2e4a4346 |
User & Date: | paul 2003-04-01 21:16:42.000 |
Context
2003-04-03
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01:50 | Use a intermediate table when inserting a TEMP table from a SELECT that reads from that same TEMP table. Ticket #275. (CVS 895) (check-in: 087d1e83af user: drh tags: trunk) | |
2003-04-01
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21:16 | Add infrastructure to suport multiple btree implementations (CVS 894) (check-in: 79b3aed2a7 user: paul tags: trunk) | |
2003-03-31
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13:36 | Minor follow-on changes to the recent ATTACH patch. (CVS 893) (check-in: 11378c5bf9 user: drh tags: trunk) | |
Changes
Changes to src/btree.c.
1 2 3 4 5 6 7 8 9 10 11 | /* ** 2001 September 15 ** ** 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 | /* ** 2001 September 15 ** ** 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 1.86 2003/04/01 21:16:42 paul 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. |
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45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 | ** ** The first page of the file contains a magic string used to verify that ** the file really is a valid BTree database, a pointer to a list of unused ** pages in the file, and some meta information. The root of the first ** BTree begins on page 2 of the file. (Pages are numbered beginning with ** 1, not 0.) Thus a minimum database contains 2 pages. */ #include "sqliteInt.h" #include "pager.h" #include "btree.h" #include <assert.h> /* ** Macros used for byteswapping. B is a pointer to the Btree ** structure. This is needed to access the Btree.needSwab boolean ** in order to tell if byte swapping is needed or not. ** X is an unsigned integer. SWAB16 byte swaps a 16-bit integer. ** SWAB32 byteswaps a 32-bit integer. */ | > > > > > > > | 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 | ** ** The first page of the file contains a magic string used to verify that ** the file really is a valid BTree database, a pointer to a list of unused ** pages in the file, and some meta information. The root of the first ** BTree begins on page 2 of the file. (Pages are numbered beginning with ** 1, not 0.) Thus a minimum database contains 2 pages. */ /* We don't want the btree function macros */ #define SQLITE_NO_BTREE_DEFS #include "sqliteInt.h" #include "pager.h" #include "btree.h" #include <assert.h> /* Forward declarations */ static BtOps sqliteBtreeOps; static BtCursorOps sqliteBtreeCursorOps; /* ** Macros used for byteswapping. B is a pointer to the Btree ** structure. This is needed to access the Btree.needSwab boolean ** in order to tell if byte swapping is needed or not. ** X is an unsigned integer. SWAB16 byte swaps a 16-bit integer. ** SWAB32 byteswaps a 32-bit integer. */ |
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336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 | */ #define EXTRA_SIZE (sizeof(MemPage)-SQLITE_PAGE_SIZE) /* ** Everything we need to know about an open database */ struct Btree { Pager *pPager; /* The page cache */ BtCursor *pCursor; /* A list of all open cursors */ PageOne *page1; /* First page of the database */ u8 inTrans; /* True if a transaction is in progress */ u8 inCkpt; /* True if there is a checkpoint on the transaction */ u8 readOnly; /* True if the underlying file is readonly */ u8 needSwab; /* Need to byte-swapping */ }; typedef Btree Bt; /* ** A cursor is a pointer to a particular entry in the BTree. ** The entry is identified by its MemPage and the index in ** MemPage.apCell[] of the entry. */ struct BtCursor { Btree *pBt; /* The Btree to which this cursor belongs */ BtCursor *pNext, *pPrev; /* Forms a linked list of all cursors */ BtCursor *pShared; /* Loop of cursors with the same root page */ Pgno pgnoRoot; /* The root page of this tree */ MemPage *pPage; /* Page that contains the entry */ int idx; /* Index of the entry in pPage->apCell[] */ u8 wrFlag; /* True if writable */ u8 eSkip; /* Determines if next step operation is a no-op */ u8 iMatch; /* compare result from last sqliteBtreeMoveto() */ }; /* ** Legal values for BtCursor.eSkip. */ #define SKIP_NONE 0 /* Always step the cursor */ #define SKIP_NEXT 1 /* The next sqliteBtreeNext() is a no-op */ #define SKIP_PREV 2 /* The next sqliteBtreePrevious() is a no-op */ #define SKIP_INVALID 3 /* Calls to Next() and Previous() are invalid */ /* ** Routines for byte swapping. */ u16 swab16(u16 x){ return ((x & 0xff)<<8) | ((x>>8)&0xff); } u32 swab32(u32 x){ | > > > > > | 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 | */ #define EXTRA_SIZE (sizeof(MemPage)-SQLITE_PAGE_SIZE) /* ** Everything we need to know about an open database */ struct Btree { BtOps *pOps; /* Function table */ Pager *pPager; /* The page cache */ BtCursor *pCursor; /* A list of all open cursors */ PageOne *page1; /* First page of the database */ u8 inTrans; /* True if a transaction is in progress */ u8 inCkpt; /* True if there is a checkpoint on the transaction */ u8 readOnly; /* True if the underlying file is readonly */ u8 needSwab; /* Need to byte-swapping */ }; typedef Btree Bt; /* ** A cursor is a pointer to a particular entry in the BTree. ** The entry is identified by its MemPage and the index in ** MemPage.apCell[] of the entry. */ struct BtCursor { BtCursorOps *pOps; /* Function table */ Btree *pBt; /* The Btree to which this cursor belongs */ BtCursor *pNext, *pPrev; /* Forms a linked list of all cursors */ BtCursor *pShared; /* Loop of cursors with the same root page */ Pgno pgnoRoot; /* The root page of this tree */ MemPage *pPage; /* Page that contains the entry */ int idx; /* Index of the entry in pPage->apCell[] */ u8 wrFlag; /* True if writable */ u8 eSkip; /* Determines if next step operation is a no-op */ u8 iMatch; /* compare result from last sqliteBtreeMoveto() */ }; /* ** Legal values for BtCursor.eSkip. */ #define SKIP_NONE 0 /* Always step the cursor */ #define SKIP_NEXT 1 /* The next sqliteBtreeNext() is a no-op */ #define SKIP_PREV 2 /* The next sqliteBtreePrevious() is a no-op */ #define SKIP_INVALID 3 /* Calls to Next() and Previous() are invalid */ /* Forward declarations */ static int sqliteBtreeCloseCursor(BtCursor *pCur); /* ** Routines for byte swapping. */ u16 swab16(u16 x){ return ((x & 0xff)<<8) | ((x>>8)&0xff); } u32 swab32(u32 x){ |
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705 706 707 708 709 710 711 712 713 714 715 716 717 718 | *ppBtree = 0; return rc; } sqlitepager_set_destructor(pBt->pPager, pageDestructor); pBt->pCursor = 0; pBt->page1 = 0; pBt->readOnly = sqlitepager_isreadonly(pBt->pPager); *ppBtree = pBt; return SQLITE_OK; } /* ** Close an open database and invalidate all cursors. */ | > | | 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 | *ppBtree = 0; return rc; } sqlitepager_set_destructor(pBt->pPager, pageDestructor); pBt->pCursor = 0; pBt->page1 = 0; pBt->readOnly = sqlitepager_isreadonly(pBt->pPager); pBt->pOps = &sqliteBtreeOps; *ppBtree = pBt; return SQLITE_OK; } /* ** Close an open database and invalidate all cursors. */ static int sqliteBtreeClose(Btree *pBt){ while( pBt->pCursor ){ sqliteBtreeCloseCursor(pBt->pCursor); } sqlitepager_close(pBt->pPager); sqliteFree(pBt); return SQLITE_OK; } |
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736 737 738 739 740 741 742 | ** and the database cannot be corrupted if this program ** crashes. But if the operating system crashes or there is ** an abrupt power failure when synchronous is off, the database ** could be left in an inconsistent and unrecoverable state. ** Synchronous is on by default so database corruption is not ** normally a worry. */ | | | | 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 | ** and the database cannot be corrupted if this program ** crashes. But if the operating system crashes or there is ** an abrupt power failure when synchronous is off, the database ** could be left in an inconsistent and unrecoverable state. ** Synchronous is on by default so database corruption is not ** normally a worry. */ static int sqliteBtreeSetCacheSize(Btree *pBt, int mxPage){ sqlitepager_set_cachesize(pBt->pPager, mxPage); return SQLITE_OK; } /* ** Change the way data is synced to disk in order to increase or decrease ** how well the database resists damage due to OS crashes and power ** failures. Level 1 is the same as asynchronous (no syncs() occur and ** there is a high probability of damage) Level 2 is the default. There ** is a very low but non-zero probability of damage. Level 3 reduces the ** probability of damage to near zero but with a write performance reduction. */ static int sqliteBtreeSetSafetyLevel(Btree *pBt, int level){ sqlitepager_set_safety_level(pBt->pPager, level); return SQLITE_OK; } /* ** Get a reference to page1 of the database file. This will ** also acquire a readlock on that file. |
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856 857 858 859 860 861 862 | ** sqliteBtreeCreateIndex() ** sqliteBtreeClearTable() ** sqliteBtreeDropTable() ** sqliteBtreeInsert() ** sqliteBtreeDelete() ** sqliteBtreeUpdateMeta() */ | | | 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 | ** sqliteBtreeCreateIndex() ** sqliteBtreeClearTable() ** sqliteBtreeDropTable() ** sqliteBtreeInsert() ** sqliteBtreeDelete() ** sqliteBtreeUpdateMeta() */ static int sqliteBtreeBeginTrans(Btree *pBt){ int rc; if( pBt->inTrans ) return SQLITE_ERROR; if( pBt->readOnly ) return SQLITE_READONLY; if( pBt->page1==0 ){ rc = lockBtree(pBt); if( rc!=SQLITE_OK ){ return rc; |
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885 886 887 888 889 890 891 | /* ** Commit the transaction currently in progress. ** ** This will release the write lock on the database file. If there ** are no active cursors, it also releases the read lock. */ | | | | 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 | /* ** Commit the transaction currently in progress. ** ** This will release the write lock on the database file. If there ** are no active cursors, it also releases the read lock. */ static int sqliteBtreeCommit(Btree *pBt){ int rc; rc = pBt->readOnly ? SQLITE_OK : sqlitepager_commit(pBt->pPager); pBt->inTrans = 0; pBt->inCkpt = 0; unlockBtreeIfUnused(pBt); return rc; } /* ** Rollback the transaction in progress. All cursors will be ** invalided by this operation. Any attempt to use a cursor ** that was open at the beginning of this operation will result ** in an error. ** ** This will release the write lock on the database file. If there ** are no active cursors, it also releases the read lock. */ static int sqliteBtreeRollback(Btree *pBt){ int rc; BtCursor *pCur; if( pBt->inTrans==0 ) return SQLITE_OK; pBt->inTrans = 0; pBt->inCkpt = 0; rc = pBt->readOnly ? SQLITE_OK : sqlitepager_rollback(pBt->pPager); for(pCur=pBt->pCursor; pCur; pCur=pCur->pNext){ |
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930 931 932 933 934 935 936 | ** main transaction. You must start a transaction before starting a ** checkpoint. The checkpoint is ended automatically if the transaction ** commits or rolls back. ** ** Only one checkpoint may be active at a time. It is an error to try ** to start a new checkpoint if another checkpoint is already active. */ | | | | | 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 | ** main transaction. You must start a transaction before starting a ** checkpoint. The checkpoint is ended automatically if the transaction ** commits or rolls back. ** ** Only one checkpoint may be active at a time. It is an error to try ** to start a new checkpoint if another checkpoint is already active. */ static int sqliteBtreeBeginCkpt(Btree *pBt){ int rc; if( !pBt->inTrans || pBt->inCkpt ){ return pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR; } rc = pBt->readOnly ? SQLITE_OK : sqlitepager_ckpt_begin(pBt->pPager); pBt->inCkpt = 1; return rc; } /* ** Commit a checkpoint to transaction currently in progress. If no ** checkpoint is active, this is a no-op. */ static int sqliteBtreeCommitCkpt(Btree *pBt){ int rc; if( pBt->inCkpt && !pBt->readOnly ){ rc = sqlitepager_ckpt_commit(pBt->pPager); }else{ rc = SQLITE_OK; } pBt->inCkpt = 0; return rc; } /* ** Rollback the checkpoint to the current transaction. If there ** is no active checkpoint or transaction, this routine is a no-op. ** ** All cursors will be invalided by this operation. Any attempt ** to use a cursor that was open at the beginning of this operation ** will result in an error. */ static int sqliteBtreeRollbackCkpt(Btree *pBt){ int rc; BtCursor *pCur; if( pBt->inCkpt==0 || pBt->readOnly ) return SQLITE_OK; rc = sqlitepager_ckpt_rollback(pBt->pPager); for(pCur=pBt->pCursor; pCur; pCur=pCur->pNext){ if( pCur->pPage && pCur->pPage->isInit==0 ){ sqlitepager_unref(pCur->pPage); |
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1015 1016 1017 1018 1019 1020 1021 | ** should be opened with wrFlag==1 even if they never really intend ** to write. ** ** No checking is done to make sure that page iTable really is the ** root page of a b-tree. If it is not, then the cursor acquired ** will not work correctly. */ | | | 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 | ** should be opened with wrFlag==1 even if they never really intend ** to write. ** ** No checking is done to make sure that page iTable really is the ** root page of a b-tree. If it is not, then the cursor acquired ** will not work correctly. */ static int sqliteBtreeCursor(Btree *pBt, int iTable, int wrFlag, BtCursor **ppCur){ int rc; BtCursor *pCur, *pRing; if( pBt->page1==0 ){ rc = lockBtree(pBt); if( rc!=SQLITE_OK ){ *ppCur = 0; |
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1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 | if( rc!=SQLITE_OK ){ goto create_cursor_exception; } rc = initPage(pBt, pCur->pPage, pCur->pgnoRoot, 0); if( rc!=SQLITE_OK ){ goto create_cursor_exception; } pCur->pBt = pBt; pCur->wrFlag = wrFlag; pCur->idx = 0; pCur->eSkip = SKIP_INVALID; pCur->pNext = pBt->pCursor; if( pCur->pNext ){ pCur->pNext->pPrev = pCur; | > | 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 | if( rc!=SQLITE_OK ){ goto create_cursor_exception; } rc = initPage(pBt, pCur->pPage, pCur->pgnoRoot, 0); if( rc!=SQLITE_OK ){ goto create_cursor_exception; } pCur->pOps = &sqliteBtreeCursorOps; pCur->pBt = pBt; pCur->wrFlag = wrFlag; pCur->idx = 0; pCur->eSkip = SKIP_INVALID; pCur->pNext = pBt->pCursor; if( pCur->pNext ){ pCur->pNext->pPrev = pCur; |
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1075 1076 1077 1078 1079 1080 1081 | return rc; } /* ** Close a cursor. The read lock on the database file is released ** when the last cursor is closed. */ | | | 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 | return rc; } /* ** Close a cursor. The read lock on the database file is released ** when the last cursor is closed. */ static int sqliteBtreeCloseCursor(BtCursor *pCur){ Btree *pBt = pCur->pBt; if( pCur->pPrev ){ pCur->pPrev->pNext = pCur->pNext; }else{ pBt->pCursor = pCur->pNext; } if( pCur->pNext ){ |
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1128 1129 1130 1131 1132 1133 1134 | /* ** Set *pSize to the number of bytes of key in the entry the ** cursor currently points to. Always return SQLITE_OK. ** Failure is not possible. If the cursor is not currently ** pointing to an entry (which can happen, for example, if ** the database is empty) then *pSize is set to 0. */ | | | 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 | /* ** Set *pSize to the number of bytes of key in the entry the ** cursor currently points to. Always return SQLITE_OK. ** Failure is not possible. If the cursor is not currently ** pointing to an entry (which can happen, for example, if ** the database is empty) then *pSize is set to 0. */ static int sqliteBtreeKeySize(BtCursor *pCur, int *pSize){ Cell *pCell; MemPage *pPage; pPage = pCur->pPage; assert( pPage!=0 ); if( pCur->idx >= pPage->nCell ){ *pSize = 0; |
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1217 1218 1219 1220 1221 1222 1223 | ** Change: It used to be that the amount returned will be smaller ** than the amount requested if there are not enough bytes in the key ** to satisfy the request. But now, it must be the case that there ** is enough data available to satisfy the request. If not, an exception ** is raised. The change was made in an effort to boost performance ** by eliminating unneeded tests. */ | | | 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 | ** Change: It used to be that the amount returned will be smaller ** than the amount requested if there are not enough bytes in the key ** to satisfy the request. But now, it must be the case that there ** is enough data available to satisfy the request. If not, an exception ** is raised. The change was made in an effort to boost performance ** by eliminating unneeded tests. */ static int sqliteBtreeKey(BtCursor *pCur, int offset, int amt, char *zBuf){ MemPage *pPage; assert( amt>=0 ); assert( offset>=0 ); assert( pCur->pPage!=0 ); pPage = pCur->pPage; if( pCur->idx >= pPage->nCell ){ |
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1239 1240 1241 1242 1243 1244 1245 | /* ** Set *pSize to the number of bytes of data in the entry the ** cursor currently points to. Always return SQLITE_OK. ** Failure is not possible. If the cursor is not currently ** pointing to an entry (which can happen, for example, if ** the database is empty) then *pSize is set to 0. */ | | | 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 | /* ** Set *pSize to the number of bytes of data in the entry the ** cursor currently points to. Always return SQLITE_OK. ** Failure is not possible. If the cursor is not currently ** pointing to an entry (which can happen, for example, if ** the database is empty) then *pSize is set to 0. */ static int sqliteBtreeDataSize(BtCursor *pCur, int *pSize){ Cell *pCell; MemPage *pPage; pPage = pCur->pPage; assert( pPage!=0 ); if( pCur->idx >= pPage->nCell ){ *pSize = 0; |
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1262 1263 1264 1265 1266 1267 1268 | ** Read part of the data associated with cursor pCur. A maximum ** of "amt" bytes will be transfered into zBuf[]. The transfer ** begins at "offset". The number of bytes actually read is ** returned. The amount returned will be smaller than the ** amount requested if there are not enough bytes in the data ** to satisfy the request. */ | | | 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 | ** Read part of the data associated with cursor pCur. A maximum ** of "amt" bytes will be transfered into zBuf[]. The transfer ** begins at "offset". The number of bytes actually read is ** returned. The amount returned will be smaller than the ** amount requested if there are not enough bytes in the data ** to satisfy the request. */ static int sqliteBtreeData(BtCursor *pCur, int offset, int amt, char *zBuf){ Cell *pCell; MemPage *pPage; assert( amt>=0 ); assert( offset>=0 ); assert( pCur->pPage!=0 ); pPage = pCur->pPage; |
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1300 1301 1302 1303 1304 1305 1306 | ** *pRes>0 This means pCur>pKey ** ** When one key is an exact prefix of the other, the shorter key is ** considered less than the longer one. In order to be equal the ** keys must be exactly the same length. (The length of the pCur key ** is the actual key length minus nIgnore bytes.) */ | | | 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 | ** *pRes>0 This means pCur>pKey ** ** When one key is an exact prefix of the other, the shorter key is ** considered less than the longer one. In order to be equal the ** keys must be exactly the same length. (The length of the pCur key ** is the actual key length minus nIgnore bytes.) */ static int sqliteBtreeKeyCompare( BtCursor *pCur, /* Pointer to entry to compare against */ const void *pKey, /* Key to compare against entry that pCur points to */ int nKey, /* Number of bytes in pKey */ int nIgnore, /* Ignore this many bytes at the end of pCur */ int *pResult /* Write the result here */ ){ Pgno nextPage; |
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1499 1500 1501 1502 1503 1504 1505 | 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. */ | | | | 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 | 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. */ static int sqliteBtreeFirst(BtCursor *pCur, int *pRes){ int rc; if( pCur->pPage==0 ) return SQLITE_ABORT; rc = moveToRoot(pCur); if( rc ) return rc; if( pCur->pPage->nCell==0 ){ *pRes = 1; return SQLITE_OK; } *pRes = 0; rc = moveToLeftmost(pCur); pCur->eSkip = SKIP_NONE; return rc; } /* Move the cursor to the last 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. */ static int sqliteBtreeLast(BtCursor *pCur, int *pRes){ int rc; if( pCur->pPage==0 ) return SQLITE_ABORT; rc = moveToRoot(pCur); if( rc ) return rc; assert( pCur->pPage->isInit ); if( pCur->pPage->nCell==0 ){ *pRes = 1; |
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1557 1558 1559 1560 1561 1562 1563 | ** ** *pRes==0 The cursor is left pointing at an entry that ** exactly matches pKey. ** ** *pRes>0 The cursor is left pointing at an entry that ** is larger than pKey. */ | | | 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 | ** ** *pRes==0 The cursor is left pointing at an entry that ** exactly matches pKey. ** ** *pRes>0 The cursor is left pointing at an entry that ** is larger than pKey. */ static int sqliteBtreeMoveto(BtCursor *pCur, const void *pKey, int nKey, int *pRes){ int rc; if( pCur->pPage==0 ) return SQLITE_ABORT; pCur->eSkip = SKIP_NONE; rc = moveToRoot(pCur); if( rc ) return rc; for(;;){ int lwr, upr; |
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1610 1611 1612 1613 1614 1615 1616 | /* ** Advance the cursor to the next entry in the database. If ** successful then set *pRes=0. If the cursor ** was already pointing to the last entry in the database before ** this routine was called, then set *pRes=1. */ | | | 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 | /* ** Advance the cursor to the next entry in the database. If ** successful then set *pRes=0. If the cursor ** was already pointing to the last entry in the database before ** this routine was called, then set *pRes=1. */ static int sqliteBtreeNext(BtCursor *pCur, int *pRes){ int rc; MemPage *pPage = pCur->pPage; assert( pRes!=0 ); if( pPage==0 ){ *pRes = 1; return SQLITE_ABORT; } |
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1665 1666 1667 1668 1669 1670 1671 | /* ** Step the cursor to the back to the previous entry in the database. If ** successful then set *pRes=0. If the cursor ** was already pointing to the first entry in the database before ** this routine was called, then set *pRes=1. */ | | | 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 | /* ** Step the cursor to the back to the previous entry in the database. If ** successful then set *pRes=0. If the cursor ** was already pointing to the first entry in the database before ** this routine was called, then set *pRes=1. */ static int sqliteBtreePrevious(BtCursor *pCur, int *pRes){ int rc; Pgno pgno; MemPage *pPage; pPage = pCur->pPage; if( pPage==0 ){ *pRes = 1; return SQLITE_ABORT; |
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2591 2592 2593 2594 2595 2596 2597 | /* ** Insert a new record into the BTree. The key is given by (pKey,nKey) ** and the data is given by (pData,nData). The cursor is used only to ** define what database the record should be inserted into. The cursor ** is left pointing at the new record. */ | | | 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 | /* ** Insert a new record into the BTree. The key is given by (pKey,nKey) ** and the data is given by (pData,nData). The cursor is used only to ** define what database the record should be inserted into. The cursor ** is left pointing at the new record. */ static int sqliteBtreeInsert( BtCursor *pCur, /* Insert data into the table of this cursor */ const void *pKey, int nKey, /* The key of the new record */ const void *pData, int nData /* The data of the new record */ ){ Cell newCell; int rc; int loc; |
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2659 2660 2661 2662 2663 2664 2665 | ** sqliteBtreeNext() after a delete and the cursor will be left ** pointing to the first entry after the deleted entry. Similarly, ** pCur->eSkip is set to SKIP_PREV is the cursor is left pointing to ** the entry prior to the deleted entry so that a subsequent call to ** sqliteBtreePrevious() will always leave the cursor pointing at the ** entry immediately before the one that was deleted. */ | | | 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 | ** sqliteBtreeNext() after a delete and the cursor will be left ** pointing to the first entry after the deleted entry. Similarly, ** pCur->eSkip is set to SKIP_PREV is the cursor is left pointing to ** the entry prior to the deleted entry so that a subsequent call to ** sqliteBtreePrevious() will always leave the cursor pointing at the ** entry immediately before the one that was deleted. */ static int sqliteBtreeDelete(BtCursor *pCur){ MemPage *pPage = pCur->pPage; Cell *pCell; int rc; Pgno pgnoChild; Btree *pBt = pCur->pBt; assert( pPage->isInit ); |
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2746 2747 2748 2749 2750 2751 2752 | ** number for the root page of the new table. ** ** In the current implementation, BTree tables and BTree indices are the ** the same. But in the future, we may change this so that BTree tables ** are restricted to having a 4-byte integer key and arbitrary data and ** BTree indices are restricted to having an arbitrary key and no data. */ | | | 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 | ** number for the root page of the new table. ** ** In the current implementation, BTree tables and BTree indices are the ** the same. But in the future, we may change this so that BTree tables ** are restricted to having a 4-byte integer key and arbitrary data and ** BTree indices are restricted to having an arbitrary key and no data. */ static int sqliteBtreeCreateTable(Btree *pBt, int *piTable){ MemPage *pRoot; Pgno pgnoRoot; int rc; if( !pBt->inTrans ){ /* Must start a transaction first */ return pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR; } |
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2775 2776 2777 2778 2779 2780 2781 | ** number for the root page of the new index. ** ** In the current implementation, BTree tables and BTree indices are the ** the same. But in the future, we may change this so that BTree tables ** are restricted to having a 4-byte integer key and arbitrary data and ** BTree indices are restricted to having an arbitrary key and no data. */ | | | 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 | ** number for the root page of the new index. ** ** In the current implementation, BTree tables and BTree indices are the ** the same. But in the future, we may change this so that BTree tables ** are restricted to having a 4-byte integer key and arbitrary data and ** BTree indices are restricted to having an arbitrary key and no data. */ static int sqliteBtreeCreateIndex(Btree *pBt, int *piIndex){ return sqliteBtreeCreateTable(pBt, piIndex); } /* ** Erase the given database page and all its children. Return ** the page to the freelist. */ |
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2822 2823 2824 2825 2826 2827 2828 | sqlitepager_unref(pPage); return rc; } /* ** Delete all information from a single table in the database. */ | | | 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 | sqlitepager_unref(pPage); return rc; } /* ** Delete all information from a single table in the database. */ static int sqliteBtreeClearTable(Btree *pBt, int iTable){ int rc; BtCursor *pCur; if( !pBt->inTrans ){ return pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR; } for(pCur=pBt->pCursor; pCur; pCur=pCur->pNext){ if( pCur->pgnoRoot==(Pgno)iTable ){ |
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2846 2847 2848 2849 2850 2851 2852 | } /* ** Erase all information in a table and add the root of the table to ** the freelist. Except, the root of the principle table (the one on ** page 2) is never added to the freelist. */ | | | 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 | } /* ** Erase all information in a table and add the root of the table to ** the freelist. Except, the root of the principle table (the one on ** page 2) is never added to the freelist. */ static int sqliteBtreeDropTable(Btree *pBt, int iTable){ int rc; MemPage *pPage; BtCursor *pCur; if( !pBt->inTrans ){ return pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR; } for(pCur=pBt->pCursor; pCur; pCur=pCur->pNext){ |
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2973 2974 2975 2976 2977 2978 2979 | return rc; } #endif /* ** Read the meta-information out of a database file. */ | | | | 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 | return rc; } #endif /* ** Read the meta-information out of a database file. */ static int sqliteBtreeGetMeta(Btree *pBt, int *aMeta){ PageOne *pP1; int rc; int i; rc = sqlitepager_get(pBt->pPager, 1, (void**)&pP1); if( rc ) return rc; aMeta[0] = SWAB32(pBt, pP1->nFree); for(i=0; i<sizeof(pP1->aMeta)/sizeof(pP1->aMeta[0]); i++){ aMeta[i+1] = SWAB32(pBt, pP1->aMeta[i]); } sqlitepager_unref(pP1); return SQLITE_OK; } /* ** Write meta-information back into the database. */ static int sqliteBtreeUpdateMeta(Btree *pBt, int *aMeta){ PageOne *pP1; int rc, i; if( !pBt->inTrans ){ return pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR; } pP1 = pBt->page1; rc = sqlitepager_write(pP1); |
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3017 3018 3019 3020 3021 3022 3023 | ******************************************************************************/ /* ** Print a disassembly of the given page on standard output. This routine ** is used for debugging and testing only. */ #ifdef SQLITE_TEST | | | 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 | ******************************************************************************/ /* ** Print a disassembly of the given page on standard output. This routine ** is used for debugging and testing only. */ #ifdef SQLITE_TEST static int sqliteBtreePageDump(Btree *pBt, int pgno, int recursive){ int rc; MemPage *pPage; int i, j; int nFree; u16 idx; char range[20]; unsigned char payload[20]; |
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3104 3105 3106 3107 3108 3109 3110 | ** aResult[4] = Number of free bytes on this page ** aResult[5] = Number of free blocks on the page ** aResult[6] = Page number of the left child of this entry ** aResult[7] = Page number of the right child for the whole page ** ** This routine is used for testing and debugging only. */ | | | 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 | ** aResult[4] = Number of free bytes on this page ** aResult[5] = Number of free blocks on the page ** aResult[6] = Page number of the left child of this entry ** aResult[7] = Page number of the right child for the whole page ** ** This routine is used for testing and debugging only. */ static int sqliteBtreeCursorDump(BtCursor *pCur, int *aResult){ int cnt, idx; MemPage *pPage = pCur->pPage; Btree *pBt = pCur->pBt; aResult[0] = sqlitepager_pagenumber(pPage); aResult[1] = pCur->idx; aResult[2] = pPage->nCell; if( pCur->idx>=0 && pCur->idx<pPage->nCell ){ |
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3136 3137 3138 3139 3140 3141 3142 | #endif #ifdef SQLITE_TEST /* ** Return the pager associated with a BTree. This routine is used for ** testing and debugging only. */ | | | 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 | #endif #ifdef SQLITE_TEST /* ** Return the pager associated with a BTree. This routine is used for ** testing and debugging only. */ static Pager *sqliteBtreePager(Btree *pBt){ return pBt->pPager; } #endif /* ** This structure is passed around through all the sanity checking routines ** in order to keep track of some global state information. |
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3476 3477 3478 3479 3480 3481 3482 | } /* Clean up and report errors. */ sqliteFree(sCheck.anRef); return sCheck.zErrMsg; } | > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 | } /* Clean up and report errors. */ sqliteFree(sCheck.anRef); return sCheck.zErrMsg; } static BtOps sqliteBtreeOps = { sqliteBtreeClose, sqliteBtreeSetCacheSize, sqliteBtreeSetSafetyLevel, sqliteBtreeBeginTrans, sqliteBtreeCommit, sqliteBtreeRollback, sqliteBtreeBeginCkpt, sqliteBtreeCommitCkpt, sqliteBtreeRollbackCkpt, sqliteBtreeCreateTable, sqliteBtreeCreateIndex, sqliteBtreeDropTable, sqliteBtreeClearTable, sqliteBtreeCursor, sqliteBtreeGetMeta, sqliteBtreeUpdateMeta, sqliteBtreeIntegrityCheck, #ifdef SQLITE_TEST sqliteBtreePageDump, sqliteBtreePager #endif }; static BtCursorOps sqliteBtreeCursorOps = { sqliteBtreeMoveto, sqliteBtreeDelete, sqliteBtreeInsert, sqliteBtreeFirst, sqliteBtreeLast, sqliteBtreeNext, sqliteBtreePrevious, sqliteBtreeKeySize, sqliteBtreeKey, sqliteBtreeKeyCompare, sqliteBtreeDataSize, sqliteBtreeData, sqliteBtreeCloseCursor, #ifdef SQLITE_TEST sqliteBtreeCursorDump, #endif }; |
Changes to src/btree.h.
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9 10 11 12 13 14 15 | ** May you share freely, never taking more than you give. ** ************************************************************************* ** This header file defines the interface that the sqlite B-Tree file ** subsystem. See comments in the source code for a detailed description ** of what each interface routine does. ** | | | | | | | | | | | | | | | | | > > > > > > > > > > > > > | > | | | | | | | | | | | | | | | > > > > > > | > | > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | > > > | > | > | > > > | 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 | ** May you share freely, never taking more than you give. ** ************************************************************************* ** This header file defines the interface that the sqlite B-Tree file ** subsystem. See comments in the source code for a detailed description ** of what each interface routine does. ** ** @(#) $Id: btree.h,v 1.29 2003/04/01 21:16:43 paul Exp $ */ #ifndef _BTREE_H_ #define _BTREE_H_ typedef struct Btree Btree; typedef struct BtCursor BtCursor; struct BtOps { int (*sqliteBtreeClose)(Btree*); int (*sqliteBtreeSetCacheSize)(Btree*, int); int (*sqliteBtreeSetSafetyLevel)(Btree*, int); int (*sqliteBtreeBeginTrans)(Btree*); int (*sqliteBtreeCommit)(Btree*); int (*sqliteBtreeRollback)(Btree*); int (*sqliteBtreeBeginCkpt)(Btree*); int (*sqliteBtreeCommitCkpt)(Btree*); int (*sqliteBtreeRollbackCkpt)(Btree*); int (*sqliteBtreeCreateTable)(Btree*, int*); int (*sqliteBtreeCreateIndex)(Btree*, int*); int (*sqliteBtreeDropTable)(Btree*, int); int (*sqliteBtreeClearTable)(Btree*, int); int (*sqliteBtreeCursor)(Btree*, int iTable, int wrFlag, BtCursor **ppCur); int (*sqliteBtreeGetMeta)(Btree*, int*); int (*sqliteBtreeUpdateMeta)(Btree*, int*); char *(*sqliteBtreeIntegrityCheck)(Btree*, int*, int); #ifdef SQLITE_TEST int (*sqliteBtreePageDump)(Btree*, int, int); struct Pager * (*sqliteBtreePager)(Btree*); #endif }; typedef struct BtOps BtOps; struct BtCursorOps { int (*sqliteBtreeMoveto)(BtCursor*, const void *pKey, int nKey, int *pRes); int (*sqliteBtreeDelete)(BtCursor*); int (*sqliteBtreeInsert)(BtCursor*, const void *pKey, int nKey, const void *pData, int nData); int (*sqliteBtreeFirst)(BtCursor*, int *pRes); int (*sqliteBtreeLast)(BtCursor*, int *pRes); int (*sqliteBtreeNext)(BtCursor*, int *pRes); int (*sqliteBtreePrevious)(BtCursor*, int *pRes); int (*sqliteBtreeKeySize)(BtCursor*, int *pSize); int (*sqliteBtreeKey)(BtCursor*, int offset, int amt, char *zBuf); int (*sqliteBtreeKeyCompare)(BtCursor*, const void *pKey, int nKey, int nIgnore, int *pRes); int (*sqliteBtreeDataSize)(BtCursor*, int *pSize); int (*sqliteBtreeData)(BtCursor*, int offset, int amt, char *zBuf); int (*sqliteBtreeCloseCursor)(BtCursor*); #ifdef SQLITE_TEST int (*sqliteBtreeCursorDump)(BtCursor*, int*); #endif }; typedef struct BtCursorOps BtCursorOps; #define SQLITE_N_BTREE_META 10 int sqliteBtreeOpen(const char *zFilename, int mode, int nPg, Btree **ppBtree); #if !defined(SQLITE_NO_BTREE_DEFS) #define btOps(pBt) (*((BtOps **)(pBt))) #define btCOps(pCur) (*((BtCursorOps **)(pCur))) #define sqliteBtreeClose(pBt)\ (btOps(pBt)->sqliteBtreeClose(pBt)) #define sqliteBtreeSetCacheSize(pBt, sz)\ (btOps(pBt)->sqliteBtreeSetCacheSize(pBt, sz)) #define sqliteBtreeSetSafetyLevel(pBt, sl)\ (btOps(pBt)->sqliteBtreeSetSafetyLevel(pBt, sl)) #define sqliteBtreeBeginTrans(pBt)\ (btOps(pBt)->sqliteBtreeBeginTrans(pBt)) #define sqliteBtreeCommit(pBt)\ (btOps(pBt)->sqliteBtreeCommit(pBt)) #define sqliteBtreeRollback(pBt)\ (btOps(pBt)->sqliteBtreeRollback(pBt)) #define sqliteBtreeBeginCkpt(pBt)\ (btOps(pBt)->sqliteBtreeBeginCkpt(pBt)) #define sqliteBtreeCommitCkpt(pBt)\ (btOps(pBt)->sqliteBtreeCommitCkpt(pBt)) #define sqliteBtreeRollbackCkpt(pBt)\ (btOps(pBt)->sqliteBtreeRollbackCkpt(pBt)) #define sqliteBtreeCreateTable(pBt, piTable)\ (btOps(pBt)->sqliteBtreeCreateTable(pBt, piTable)) #define sqliteBtreeCreateIndex(pBt, piIndex)\ (btOps(pBt)->sqliteBtreeCreateIndex(pBt, piIndex)) #define sqliteBtreeDropTable(pBt, iTable)\ (btOps(pBt)->sqliteBtreeDropTable(pBt, iTable)) #define sqliteBtreeClearTable(pBt, iTable)\ (btOps(pBt)->sqliteBtreeClearTable(pBt, iTable)) #define sqliteBtreeCursor(pBt, iTable, wrFlag, ppCur)\ (btOps(pBt)->sqliteBtreeCursor(pBt, iTable, wrFlag, ppCur)) #define sqliteBtreeMoveto(pCur, pKey, nKey, pRes)\ (btCOps(pCur)->sqliteBtreeMoveto(pCur, pKey, nKey, pRes)) #define sqliteBtreeDelete(pCur)\ (btCOps(pCur)->sqliteBtreeDelete(pCur)) #define sqliteBtreeInsert(pCur, pKey, nKey, pData, nData) \ (btCOps(pCur)->sqliteBtreeInsert(pCur, pKey, nKey, pData, nData)) #define sqliteBtreeFirst(pCur, pRes)\ (btCOps(pCur)->sqliteBtreeFirst(pCur, pRes)) #define sqliteBtreeLast(pCur, pRes)\ (btCOps(pCur)->sqliteBtreeLast(pCur, pRes)) #define sqliteBtreeNext(pCur, pRes)\ (btCOps(pCur)->sqliteBtreeNext(pCur, pRes)) #define sqliteBtreePrevious(pCur, pRes)\ (btCOps(pCur)->sqliteBtreePrevious(pCur, pRes)) #define sqliteBtreeKeySize(pCur, pSize)\ (btCOps(pCur)->sqliteBtreeKeySize(pCur, pSize) ) #define sqliteBtreeKey(pCur, offset, amt, zBuf)\ (btCOps(pCur)->sqliteBtreeKey(pCur, offset, amt, zBuf)) #define sqliteBtreeKeyCompare(pCur, pKey, nKey, nIgnore, pRes)\ (btCOps(pCur)->sqliteBtreeKeyCompare(pCur, pKey, nKey, nIgnore, pRes)) #define sqliteBtreeDataSize(pCur, pSize)\ (btCOps(pCur)->sqliteBtreeDataSize(pCur, pSize)) #define sqliteBtreeData(pCur, offset, amt, zBuf)\ (btCOps(pCur)->sqliteBtreeData(pCur, offset, amt, zBuf)) #define sqliteBtreeCloseCursor(pCur)\ (btCOps(pCur)->sqliteBtreeCloseCursor(pCur)) #define sqliteBtreeGetMeta(pBt, aMeta)\ (btOps(pBt)->sqliteBtreeGetMeta(pBt, aMeta)) #define sqliteBtreeUpdateMeta(pBt, aMeta)\ (btOps(pBt)->sqliteBtreeUpdateMeta(pBt, aMeta)) #define sqliteBtreeIntegrityCheck(pBt, aRoot, nRoot)\ (btOps(pBt)->sqliteBtreeIntegrityCheck(pBt, aRoot, nRoot)) #endif #ifdef SQLITE_TEST #if !defined(SQLITE_NO_BTREE_DEFS) #define sqliteBtreePageDump(pBt, pgno, recursive)\ (btOps(pBt)->sqliteBtreePageDump(pBt, pgno, recursive)) #define sqliteBtreeCursorDump(pCur, aResult)\ (btCOps(pCur)->sqliteBtreeCursorDump(pCur, aResult)) #define sqliteBtreePager(pBt)\ (btOps(pBt)->sqliteBtreePager(pBt)) #endif int btree_native_byte_order; #endif #endif /* _BTREE_H_ */ |