src/btree.h

   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 #ifndef _BTREE_H_
  17 #define _BTREE_H_
  18
  19 /* TODO: This definition is just included so other modules compile. It
  20 ** needs to be revisited.
  21 */
  22 #define SQLITE_N_BTREE_META 10
  23
  24 /*
  25 ** If defined as non-zero, auto-vacuum is enabled by default. Otherwise
  26 ** it must be turned on for each database using "PRAGMA auto_vacuum = 1".
  27 */
  28 #ifndef SQLITE_DEFAULT_AUTOVACUUM
  29   #define SQLITE_DEFAULT_AUTOVACUUM 0
  30 #endif
  31
  32 #define BTREE_AUTOVACUUM_NONE 0        /* Do not do auto-vacuum */
  33 #define BTREE_AUTOVACUUM_FULL 1        /* Do full auto-vacuum */
  34 #define BTREE_AUTOVACUUM_INCR 2        /* Incremental vacuum */
  35
  36 /*
  37 ** Forward declarations of structure
  38 */
  39 typedef struct Btree Btree;
  40 typedef struct BtCursor BtCursor;
  41 typedef struct BtShared BtShared;
  42
  43
  44 int sqlite3BtreeOpen(
  45   sqlite3_vfs *pVfs,       /* VFS to use with this b-tree */
  46   const char *zFilename,   /* Name of database file to open */
  47   sqlite3 *db,             /* Associated database connection */
  48   Btree **ppBtree,         /* Return open Btree* here */
  49   int flags,               /* Flags */
  50   int vfsFlags             /* Flags passed through to VFS open */
  51 );
  52
  53 /* The flags parameter to sqlite3BtreeOpen can be the bitwise or of the
  54 ** following values.
  55 **
  56 ** NOTE:  These values must match the corresponding PAGER_ values in
  57 ** pager.h.
  58 */
  59 #define BTREE_OMIT_JOURNAL  1  /* Do not create or use a rollback journal */
  60 #define BTREE_MEMORY        2  /* This is an in-memory DB */
  61 #define BTREE_SINGLE        4  /* The file contains at most 1 b-tree */
  62 #define BTREE_UNORDERED     8  /* Use of a hash implementation is OK */
  63
  64 int sqlite3BtreeClose(Btree*);
  65 int sqlite3BtreeSetCacheSize(Btree*,int);
  66 int sqlite3BtreeSetSafetyLevel(Btree*,int,int,int);
  67 int sqlite3BtreeSyncDisabled(Btree*);
  68 int sqlite3BtreeSetPageSize(Btree *p, int nPagesize, int nReserve, int eFix);
  69 int sqlite3BtreeGetPageSize(Btree*);
  70 int sqlite3BtreeMaxPageCount(Btree*,int);
  71 u32 sqlite3BtreeLastPage(Btree*);
  72 int sqlite3BtreeSecureDelete(Btree*,int);
  73 int sqlite3BtreeGetReserve(Btree*);
  74 int sqlite3BtreeSetAutoVacuum(Btree *, int);
  75 int sqlite3BtreeGetAutoVacuum(Btree *);
  76 int sqlite3BtreeBeginTrans(Btree*,int);
  77 int sqlite3BtreeCommitPhaseOne(Btree*, const char *zMaster);
  78 int sqlite3BtreeCommitPhaseTwo(Btree*, int);
  79 int sqlite3BtreeCommit(Btree*);
  80 int sqlite3BtreeRollback(Btree*,int);
  81 int sqlite3BtreeBeginStmt(Btree*,int);
  82 int sqlite3BtreeCreateTable(Btree*, int*, int flags);
  83 int sqlite3BtreeIsInTrans(Btree*);
  84 int sqlite3BtreeIsInReadTrans(Btree*);
  85 int sqlite3BtreeIsInBackup(Btree*);
  86 void *sqlite3BtreeSchema(Btree *, int, void(*)(void *));
  87 int sqlite3BtreeSchemaLocked(Btree *pBtree);
  88 int sqlite3BtreeLockTable(Btree *pBtree, int iTab, u8 isWriteLock);
  89 int sqlite3BtreeSavepoint(Btree *, int, int);
  90
  91 const char *sqlite3BtreeGetFilename(Btree *);
  92 const char *sqlite3BtreeGetJournalname(Btree *);
  93 int sqlite3BtreeCopyFile(Btree *, Btree *);
  94
  95 int sqlite3BtreeIncrVacuum(Btree *);
  96
  97 /* The flags parameter to sqlite3BtreeCreateTable can be the bitwise OR
  98 ** of the flags shown below.
  99 **
 100 ** Every SQLite table must have either BTREE_INTKEY or BTREE_BLOBKEY set.
 101 ** With BTREE_INTKEY, the table key is a 64-bit integer and arbitrary data
 102 ** is stored in the leaves.  (BTREE_INTKEY is used for SQL tables.)  With
 103 ** BTREE_BLOBKEY, the key is an arbitrary BLOB and no content is stored
 104 ** anywhere - the key is the content.  (BTREE_BLOBKEY is used for SQL
 105 ** indices.)
 106 */
 107 #define BTREE_INTKEY     1    /* Table has only 64-bit signed integer keys */
 108 #define BTREE_BLOBKEY    2    /* Table has keys only - no data */
 109
 110 int sqlite3BtreeDropTable(Btree*, int, int*);
 111 int sqlite3BtreeClearTable(Btree*, int, int*);
 112 void sqlite3BtreeTripAllCursors(Btree*, int);
 113
 114 void sqlite3BtreeGetMeta(Btree *pBtree, int idx, u32 *pValue);
 115 int sqlite3BtreeUpdateMeta(Btree*, int idx, u32 value);
 116
 117 /*
 118 ** The second parameter to sqlite3BtreeGetMeta or sqlite3BtreeUpdateMeta
 119 ** should be one of the following values. The integer values are assigned
 120 ** to constants so that the offset of the corresponding field in an
 121 ** SQLite database header may be found using the following formula:
 122 **
 123 **   offset = 36 + (idx * 4)
 124 **
 125 ** For example, the free-page-count field is located at byte offset 36 of
 126 ** the database file header. The incr-vacuum-flag field is located at
 127 ** byte offset 64 (== 36+4*7).
 128 */
 129 #define BTREE_FREE_PAGE_COUNT     0
 130 #define BTREE_SCHEMA_VERSION      1
 131 #define BTREE_FILE_FORMAT         2
 132 #define BTREE_DEFAULT_CACHE_SIZE  3
 133 #define BTREE_LARGEST_ROOT_PAGE   4
 134 #define BTREE_TEXT_ENCODING       5
 135 #define BTREE_USER_VERSION        6
 136 #define BTREE_INCR_VACUUM         7
 137
 138 int sqlite3BtreeCursor(
 139   Btree*,                              /* BTree containing table to open */
 140   int iTable,                          /* Index of root page */
 141   int wrFlag,                          /* 1 for writing.  0 for read-only */
 142   struct KeyInfo*,                     /* First argument to compare function */
 143   BtCursor *pCursor                    /* Space to write cursor structure */
 144 );
 145 int sqlite3BtreeCursorSize(void);
 146 void sqlite3BtreeCursorZero(BtCursor*);
 147
 148 int sqlite3BtreeCloseCursor(BtCursor*);
 149 int sqlite3BtreeMovetoUnpacked(
 150   BtCursor*,
 151   UnpackedRecord *pUnKey,
 152   i64 intKey,
 153   int bias,
 154   int *pRes
 155 );
 156 int sqlite3BtreeCursorHasMoved(BtCursor*, int*);
 157 int sqlite3BtreeDelete(BtCursor*);
 158 int sqlite3BtreeInsert(BtCursor*, const void *pKey, i64 nKey,
 159                                   const void *pData, int nData,
 160                                   int nZero, int bias, int seekResult);
 161 int sqlite3BtreeFirst(BtCursor*, int *pRes);
 162 int sqlite3BtreeLast(BtCursor*, int *pRes);
 163 int sqlite3BtreeNext(BtCursor*, int *pRes);
 164 int sqlite3BtreeEof(BtCursor*);
 165 int sqlite3BtreePrevious(BtCursor*, int *pRes);
 166 int sqlite3BtreeKeySize(BtCursor*, i64 *pSize);
 167 int sqlite3BtreeKey(BtCursor*, u32 offset, u32 amt, void*);
 168 const void *sqlite3BtreeKeyFetch(BtCursor*, int *pAmt);
 169 const void *sqlite3BtreeDataFetch(BtCursor*, int *pAmt);
 170 int sqlite3BtreeDataSize(BtCursor*, u32 *pSize);
 171 int sqlite3BtreeData(BtCursor*, u32 offset, u32 amt, void*);
 172 void sqlite3BtreeSetCachedRowid(BtCursor*, sqlite3_int64);
 173 sqlite3_int64 sqlite3BtreeGetCachedRowid(BtCursor*);
 174
 175 char *sqlite3BtreeIntegrityCheck(Btree*, int *aRoot, int nRoot, int, int*);
 176 struct Pager *sqlite3BtreePager(Btree*);
 177
 178 int sqlite3BtreePutData(BtCursor*, u32 offset, u32 amt, void*);
 179 void sqlite3BtreeCacheOverflow(BtCursor *);
 180 void sqlite3BtreeClearCursor(BtCursor *);
 181
 182 int sqlite3BtreeSetVersion(Btree *pBt, int iVersion);
 183
 184 #ifndef NDEBUG
 185 int sqlite3BtreeCursorIsValid(BtCursor*);
 186 #endif
 187
 188 #ifndef SQLITE_OMIT_BTREECOUNT
 189 int sqlite3BtreeCount(BtCursor *, i64 *);
 190 #endif
 191
 192 #ifdef SQLITE_TEST
 193 int sqlite3BtreeCursorInfo(BtCursor*, int*, int);
 194 void sqlite3BtreeCursorList(Btree*);
 195 #endif
 196
 197 #ifndef SQLITE_OMIT_WAL
 198   int sqlite3BtreeCheckpoint(Btree*, int, int *, int *);
 199 #endif
 200
 201 /*
 202 ** If we are not using shared cache, then there is no need to
 203 ** use mutexes to access the BtShared structures.  So make the
 204 ** Enter and Leave procedures no-ops.
 205 */
 206 #ifndef SQLITE_OMIT_SHARED_CACHE
 207   void sqlite3BtreeEnter(Btree*);
 208   void sqlite3BtreeEnterAll(sqlite3*);
 209 #else
 210 # define sqlite3BtreeEnter(X)
 211 # define sqlite3BtreeEnterAll(X)
 212 #endif
 213
 214 #if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE
 215   int sqlite3BtreeSharable(Btree*);
 216   void sqlite3BtreeLeave(Btree*);
 217   void sqlite3BtreeEnterCursor(BtCursor*);
 218   void sqlite3BtreeLeaveCursor(BtCursor*);
 219   void sqlite3BtreeLeaveAll(sqlite3*);
 220 #ifndef NDEBUG
 221   /* These routines are used inside assert() statements only. */
 222   int sqlite3BtreeHoldsMutex(Btree*);
 223   int sqlite3BtreeHoldsAllMutexes(sqlite3*);
 224   int sqlite3SchemaMutexHeld(sqlite3*,int,Schema*);
 225 #endif
 226 #else
 227
 228 # define sqlite3BtreeSharable(X) 0
 229 # define sqlite3BtreeLeave(X)
 230 # define sqlite3BtreeEnterCursor(X)
 231 # define sqlite3BtreeLeaveCursor(X)
 232 # define sqlite3BtreeLeaveAll(X)
 233
 234 # define sqlite3BtreeHoldsMutex(X) 1
 235 # define sqlite3BtreeHoldsAllMutexes(X) 1
 236 # define sqlite3SchemaMutexHeld(X,Y,Z) 1
 237 #endif
 238
 239
 240 #endif /* _BTREE_H_ */