1 /* 2 ** 2001 September 15 3 ** 4 ** The author disclaims copyright to this source code. In place of 5 ** a legal notice, here is a blessing: 6 ** 7 ** May you do good and not evil. 8 ** May you find forgiveness for yourself and forgive others. 9 ** May you share freely, never taking more than you give. 10 ** 11 ************************************************************************* 12 ** This header file defines the interface that the sqlite B-Tree file 13 ** subsystem. See comments in the source code for a detailed description 14 ** of what each interface routine does. 15 ** 16 ** @(#) $Id$ 17 */ 18 #ifndef _BTREE_H_ 19 #define _BTREE_H_ 20 21 /* 22 ** Forward declarations of structure 23 */ 24 typedef struct Btree Btree; 25 typedef struct BtCursor BtCursor; 26 typedef struct BtOps BtOps; 27 typedef struct BtCursorOps BtCursorOps; 28 29 30 /* 31 ** An instance of the following structure contains pointers to all 32 ** methods against an open BTree. Alternative BTree implementations 33 ** (examples: file based versus in-memory) can be created by substituting 34 ** different methods. Users of the BTree cannot tell the difference. 35 ** 36 ** In C++ we could do this by defining a virtual base class and then 37 ** creating subclasses for each different implementation. But this is 38 ** C not C++ so we have to be a little more explicit. 39 */ 40 struct BtOps { 41 int (*Close)(Btree*); 42 int (*SetCacheSize)(Btree*, int); 43 int (*SetSafetyLevel)(Btree*, int); 44 int (*BeginTrans)(Btree*); 45 int (*Commit)(Btree*); 46 int (*Rollback)(Btree*); 47 int (*BeginCkpt)(Btree*); 48 int (*CommitCkpt)(Btree*); 49 int (*RollbackCkpt)(Btree*); 50 int (*CreateTable)(Btree*, int*); 51 int (*CreateIndex)(Btree*, int*); 52 int (*DropTable)(Btree*, int); 53 int (*ClearTable)(Btree*, int); 54 int (*Cursor)(Btree*, int iTable, int wrFlag, BtCursor **ppCur); 55 int (*GetMeta)(Btree*, int*); 56 int (*UpdateMeta)(Btree*, int*); 57 char *(*IntegrityCheck)(Btree*, int*, int); 58 const char *(*GetFilename)(Btree*); 59 int (*Copyfile)(Btree*,Btree*); 60 struct Pager *(*Pager)(Btree*); 61 #ifdef SQLITE_TEST 62 int (*PageDump)(Btree*, int, int); 63 #endif 64 }; 65 66 /* 67 ** An instance of this structure defines all of the methods that can 68 ** be executed against a cursor. 69 */ 70 struct BtCursorOps { 71 int (*Moveto)(BtCursor*, const void *pKey, int nKey, int *pRes); 72 int (*Delete)(BtCursor*); 73 int (*Insert)(BtCursor*, const void *pKey, int nKey, 74 const void *pData, int nData); 75 int (*First)(BtCursor*, int *pRes); 76 int (*Last)(BtCursor*, int *pRes); 77 int (*Next)(BtCursor*, int *pRes); 78 int (*Previous)(BtCursor*, int *pRes); 79 int (*KeySize)(BtCursor*, int *pSize); 80 int (*Key)(BtCursor*, int offset, int amt, char *zBuf); 81 int (*KeyCompare)(BtCursor*, const void *pKey, int nKey, 82 int nIgnore, int *pRes); 83 int (*DataSize)(BtCursor*, int *pSize); 84 int (*Data)(BtCursor*, int offset, int amt, char *zBuf); 85 int (*CloseCursor)(BtCursor*); 86 #ifdef SQLITE_TEST 87 int (*CursorDump)(BtCursor*, int*); 88 #endif 89 }; 90 91 /* 92 ** The number of 4-byte "meta" values contained on the first page of each 93 ** database file. 94 */ 95 #define SQLITE_N_BTREE_META 10 96 97 int sqliteBtreeOpen(const char *zFilename, int mode, int nPg, Btree **ppBtree); 98 int sqliteRbtreeOpen(const char *zFilename, int mode, int nPg, Btree **ppBtree); 99 100 #define btOps(pBt) (*((BtOps **)(pBt))) 101 #define btCOps(pCur) (*((BtCursorOps **)(pCur))) 102 103 #define sqliteBtreeClose(pBt) (btOps(pBt)->Close(pBt)) 104 #define sqliteBtreeSetCacheSize(pBt, sz) (btOps(pBt)->SetCacheSize(pBt, sz)) 105 #define sqliteBtreeSetSafetyLevel(pBt, sl) (btOps(pBt)->SetSafetyLevel(pBt, sl)) 106 #define sqliteBtreeBeginTrans(pBt) (btOps(pBt)->BeginTrans(pBt)) 107 #define sqliteBtreeCommit(pBt) (btOps(pBt)->Commit(pBt)) 108 #define sqliteBtreeRollback(pBt) (btOps(pBt)->Rollback(pBt)) 109 #define sqliteBtreeBeginCkpt(pBt) (btOps(pBt)->BeginCkpt(pBt)) 110 #define sqliteBtreeCommitCkpt(pBt) (btOps(pBt)->CommitCkpt(pBt)) 111 #define sqliteBtreeRollbackCkpt(pBt) (btOps(pBt)->RollbackCkpt(pBt)) 112 #define sqliteBtreeCreateTable(pBt,piTable)\ 113 (btOps(pBt)->CreateTable(pBt,piTable)) 114 #define sqliteBtreeCreateIndex(pBt, piIndex)\ 115 (btOps(pBt)->CreateIndex(pBt, piIndex)) 116 #define sqliteBtreeDropTable(pBt, iTable) (btOps(pBt)->DropTable(pBt, iTable)) 117 #define sqliteBtreeClearTable(pBt, iTable)\ 118 (btOps(pBt)->ClearTable(pBt, iTable)) 119 #define sqliteBtreeCursor(pBt, iTable, wrFlag, ppCur)\ 120 (btOps(pBt)->Cursor(pBt, iTable, wrFlag, ppCur)) 121 #define sqliteBtreeMoveto(pCur, pKey, nKey, pRes)\ 122 (btCOps(pCur)->Moveto(pCur, pKey, nKey, pRes)) 123 #define sqliteBtreeDelete(pCur) (btCOps(pCur)->Delete(pCur)) 124 #define sqliteBtreeInsert(pCur, pKey, nKey, pData, nData) \ 125 (btCOps(pCur)->Insert(pCur, pKey, nKey, pData, nData)) 126 #define sqliteBtreeFirst(pCur, pRes) (btCOps(pCur)->First(pCur, pRes)) 127 #define sqliteBtreeLast(pCur, pRes) (btCOps(pCur)->Last(pCur, pRes)) 128 #define sqliteBtreeNext(pCur, pRes) (btCOps(pCur)->Next(pCur, pRes)) 129 #define sqliteBtreePrevious(pCur, pRes) (btCOps(pCur)->Previous(pCur, pRes)) 130 #define sqliteBtreeKeySize(pCur, pSize) (btCOps(pCur)->KeySize(pCur, pSize) ) 131 #define sqliteBtreeKey(pCur, offset, amt, zBuf)\ 132 (btCOps(pCur)->Key(pCur, offset, amt, zBuf)) 133 #define sqliteBtreeKeyCompare(pCur, pKey, nKey, nIgnore, pRes)\ 134 (btCOps(pCur)->KeyCompare(pCur, pKey, nKey, nIgnore, pRes)) 135 #define sqliteBtreeDataSize(pCur, pSize) (btCOps(pCur)->DataSize(pCur, pSize)) 136 #define sqliteBtreeData(pCur, offset, amt, zBuf)\ 137 (btCOps(pCur)->Data(pCur, offset, amt, zBuf)) 138 #define sqliteBtreeCloseCursor(pCur) (btCOps(pCur)->CloseCursor(pCur)) 139 #define sqliteBtreeGetMeta(pBt, aMeta) (btOps(pBt)->GetMeta(pBt, aMeta)) 140 #define sqliteBtreeUpdateMeta(pBt, aMeta) (btOps(pBt)->UpdateMeta(pBt, aMeta)) 141 #define sqliteBtreeIntegrityCheck(pBt, aRoot, nRoot)\ 142 (btOps(pBt)->IntegrityCheck(pBt, aRoot, nRoot)) 143 #define sqliteBtreeGetFilename(pBt) (btOps(pBt)->GetFilename(pBt)) 144 #define sqliteBtreeCopyFile(pBt1, pBt2) (btOps(pBt1)->Copyfile(pBt1, pBt2)) 145 #define sqliteBtreePager(pBt) (btOps(pBt)->Pager(pBt)) 146 147 #ifdef SQLITE_TEST 148 #define sqliteBtreePageDump(pBt, pgno, recursive)\ 149 (btOps(pBt)->PageDump(pBt, pgno, recursive)) 150 #define sqliteBtreeCursorDump(pCur, aResult)\ 151 (btCOps(pCur)->CursorDump(pCur, aResult)) 152 int btree_native_byte_order; 153 #endif /* SQLITE_TEST */ 154 155 156 #endif /* _BTREE_H_ */ 157
