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** 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.
** 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.
/* TODO: This definition is just included so other modules compile. It
** needs to be revisited.
** If defined as non-zero, auto-vacuum is enabled by default. Otherwise
** it must be turned on for each database using "PRAGMA auto_vacuum = 1".
#define BTREE_AUTOVACUUM_NONE 0 /* Do not do auto-vacuum */
#define BTREE_AUTOVACUUM_FULL 1 /* Do full auto-vacuum */
#define BTREE_AUTOVACUUM_INCR 2 /* Incremental vacuum */
** Forward declarations of structure
typedef struct Btree Btree;
typedef struct BtCursor BtCursor;
typedef struct BtShared BtShared;
typedef struct BtreePayload BtreePayload;
int sqlite3BtreeOpen(
sqlite3_vfs *pVfs, /* VFS to use with this b-tree */
const char *zFilename, /* Name of database file to open */
sqlite3 *db, /* Associated database connection */
Btree **ppBtree, /* Return open Btree* here */
int flags, /* Flags */
int vfsFlags /* Flags passed through to VFS open */
/* The flags parameter to sqlite3BtreeOpen can be the bitwise or of the
** following values.
** NOTE: These values must match the corresponding PAGER_ values in
** pager.h.
#define BTREE_OMIT_JOURNAL 1 /* Do not create or use a rollback journal */
#define BTREE_MEMORY 2 /* This is an in-memory DB */
#define BTREE_SINGLE 4 /* The file contains at most 1 b-tree */
#define BTREE_UNORDERED 8 /* Use of a hash implementation is OK */
int sqlite3BtreeClose(Btree*);
int sqlite3BtreeSetCacheSize(Btree*,int);
int sqlite3BtreeSetSpillSize(Btree*,int);
int sqlite3BtreeSetMmapLimit(Btree*,sqlite3_int64);
int sqlite3BtreeSetPagerFlags(Btree*,unsigned);
int sqlite3BtreeSetPageSize(Btree *p, int nPagesize, int nReserve, int eFix);
int sqlite3BtreeGetPageSize(Btree*);
int sqlite3BtreeMaxPageCount(Btree*,int);
u32 sqlite3BtreeLastPage(Btree*);
int sqlite3BtreeSecureDelete(Btree*,int);
int sqlite3BtreeGetOptimalReserve(Btree*);
int sqlite3BtreeGetReserveNoMutex(Btree *p);
int sqlite3BtreeSetAutoVacuum(Btree *, int);
int sqlite3BtreeGetAutoVacuum(Btree *);
int sqlite3BtreeBeginTrans(Btree*,int,int*);
int sqlite3BtreeCommitPhaseOne(Btree*, const char *zMaster);
int sqlite3BtreeCommitPhaseTwo(Btree*, int);
int sqlite3BtreeCommit(Btree*);
int sqlite3BtreeRollback(Btree*,int,int);
int sqlite3BtreeBeginStmt(Btree*,int);
int sqlite3BtreeCreateTable(Btree*, int*, int flags);
int sqlite3BtreeIsInTrans(Btree*);
int sqlite3BtreeIsInReadTrans(Btree*);
int sqlite3BtreeIsInBackup(Btree*);
void *sqlite3BtreeSchema(Btree *, int, void(*)(void *));
int sqlite3BtreeSchemaLocked(Btree *pBtree);
int sqlite3BtreeLockTable(Btree *pBtree, int iTab, u8 isWriteLock);
int sqlite3BtreeSavepoint(Btree *, int, int);
const char *sqlite3BtreeGetFilename(Btree *);
const char *sqlite3BtreeGetJournalname(Btree *);
int sqlite3BtreeCopyFile(Btree *, Btree *);
int sqlite3BtreeIncrVacuum(Btree *);
/* The flags parameter to sqlite3BtreeCreateTable can be the bitwise OR
** of the flags shown below.
** Every SQLite table must have either BTREE_INTKEY or BTREE_BLOBKEY set.
** With BTREE_INTKEY, the table key is a 64-bit integer and arbitrary data
** is stored in the leaves. (BTREE_INTKEY is used for SQL tables.) With
** BTREE_BLOBKEY, the key is an arbitrary BLOB and no content is stored
** anywhere - the key is the content. (BTREE_BLOBKEY is used for SQL
** indices.)
#define BTREE_INTKEY 1 /* Table has only 64-bit signed integer keys */
#define BTREE_BLOBKEY 2 /* Table has keys only - no data */
int sqlite3BtreeDropTable(Btree*, int, int*);
int sqlite3BtreeClearTable(Btree*, int, int*);
int sqlite3BtreeClearTableOfCursor(BtCursor*);
int sqlite3BtreeTripAllCursors(Btree*, int, int);
void sqlite3BtreeGetMeta(Btree *pBtree, int idx, u32 *pValue);
int sqlite3BtreeUpdateMeta(Btree*, int idx, u32 value);
int sqlite3BtreeNewDb(Btree *p);
** The second parameter to sqlite3BtreeGetMeta or sqlite3BtreeUpdateMeta
** should be one of the following values. The integer values are assigned
** to constants so that the offset of the corresponding field in an
** SQLite database header may be found using the following formula:
** offset = 36 + (idx * 4)
** For example, the free-page-count field is located at byte offset 36 of
** the database file header. The incr-vacuum-flag field is located at
** byte offset 64 (== 36+4*7).
** The BTREE_DATA_VERSION value is not really a value stored in the header.
** It is a read-only number computed by the pager. But we merge it with
** the header value access routines since its access pattern is the same.
** Call it a "virtual meta value".
#define BTREE_DATA_VERSION 15 /* A virtual meta-value */
** Kinds of hints that can be passed into the sqlite3BtreeCursorHint()
** interface.
** BTREE_HINT_RANGE (arguments: Expr*, Mem*)
** The first argument is an Expr* (which is guaranteed to be constant for
** the lifetime of the cursor) that defines constraints on which rows
** might be fetched with this cursor. The Expr* tree may contain
** TK_REGISTER nodes that refer to values stored in the array of registers
** passed as the second parameter. In other words, if Expr.op==TK_REGISTER
** then the value of the node is the value in Mem[pExpr.iTable]. Any
** TK_COLUMN node in the expression tree refers to the Expr.iColumn-th
** column of the b-tree of the cursor. The Expr tree will not contain
** any function calls nor subqueries nor references to b-trees other than
** the cursor being hinted.
** The design of the _RANGE hint is aid b-tree implementations that try
** to prefetch content from remote machines - to provide those
** implementations with limits on what needs to be prefetched and thereby
** reduce network bandwidth.
** Note that BTREE_HINT_FLAGS with BTREE_BULKLOAD is the only hint used by
** standard SQLite. The other hints are provided for extentions that use
** the SQLite parser and code generator but substitute their own storage
** engine.
#define BTREE_HINT_RANGE 0 /* Range constraints on queries */
** Values that may be OR'd together to form the argument to the
** BTREE_HINT_FLAGS hint for sqlite3BtreeCursorHint():
** The BTREE_BULKLOAD flag is set on index cursors when the index is going
** to be filled with content that is already in sorted order.
** The BTREE_SEEK_EQ flag is set on cursors that will get OP_SeekGE or
** OP_SeekLE opcodes for a range search, but where the range of entries
** selected will all have the same key. In other words, the cursor will
** be used only for equality key searches.
#define BTREE_BULKLOAD 0x00000001 /* Used to full index in sorted order */
#define BTREE_SEEK_EQ 0x00000002 /* EQ seeks only - no range seeks */
** Flags passed as the third argument to sqlite3BtreeCursor().
** For read-only cursors the wrFlag argument is always zero. For read-write
** cursors it may be set to either (BTREE_WRCSR|BTREE_FORDELETE) or just
** (BTREE_WRCSR). If the BTREE_FORDELETE bit is set, then the cursor will
** only be used by SQLite for the following:
** * to seek to and then delete specific entries, and/or
** * to read values that will be used to create keys that other
** BTREE_FORDELETE cursors will seek to and delete.
** The BTREE_FORDELETE flag is an optimization hint. It is not used by
** by this, the native b-tree engine of SQLite, but it is available to
** alternative storage engines that might be substituted in place of this
** b-tree system. For alternative storage engines in which a delete of
** the main table row automatically deletes corresponding index rows,
** the FORDELETE flag hint allows those alternative storage engines to
** skip a lot of work. Namely: FORDELETE cursors may treat all SEEK
** and DELETE operations as no-ops, and any READ operation against a
** FORDELETE cursor may return a null row: 0x01 0x00.
#define BTREE_WRCSR 0x00000004 /* read-write cursor */
#define BTREE_FORDELETE 0x00000008 /* Cursor is for seek/delete only */
int sqlite3BtreeCursor(
Btree*, /* BTree containing table to open */
int iTable, /* Index of root page */
int wrFlag, /* 1 for writing. 0 for read-only */
struct KeyInfo*, /* First argument to compare function */
BtCursor *pCursor /* Space to write cursor structure */
BtCursor *sqlite3BtreeFakeValidCursor(void);
int sqlite3BtreeCursorSize(void);
void sqlite3BtreeCursorZero(BtCursor*);
void sqlite3BtreeCursorHintFlags(BtCursor*, unsigned);
void sqlite3BtreeCursorHint(BtCursor*, int, ...);
int sqlite3BtreeCloseCursor(BtCursor*);
int sqlite3BtreeMovetoUnpacked(
UnpackedRecord *pUnKey,
i64 intKey,
int bias,
int *pRes
int sqlite3BtreeCursorHasMoved(BtCursor*);
int sqlite3BtreeCursorRestore(BtCursor*, int*);
int sqlite3BtreeDelete(BtCursor*, u8 flags);
/* Allowed flags for sqlite3BtreeDelete() and sqlite3BtreeInsert() */
#define BTREE_SAVEPOSITION 0x02 /* Leave cursor pointing at NEXT or PREV */
#define BTREE_AUXDELETE 0x04 /* not the primary delete operation */
#define BTREE_APPEND 0x08 /* Insert is likely an append */
/* An instance of the BtreePayload object describes the content of a single
** entry in either an index or table btree.
** Index btrees (used for indexes and also WITHOUT ROWID tables) contain
** an arbitrary key and no data. These btrees have pKey,nKey set to the
** key and the pData,nData,nZero fields are uninitialized. The aMem,nMem
** fields give an array of Mem objects that are a decomposition of the key.
** The nMem field might be zero, indicating that no decomposition is available.
** Table btrees (used for rowid tables) contain an integer rowid used as
** the key and passed in the nKey field. The pKey field is zero.
** pData,nData hold the content of the new entry. nZero extra zero bytes
** are appended to the end of the content when constructing the entry.
** The aMem,nMem fields are uninitialized for table btrees.
** Field usage summary:
** Table BTrees Index Btrees
** pKey always NULL encoded key
** nKey the ROWID length of pKey
** pData data not used
** aMem not used decomposed key value
** nMem not used entries in aMem
** nData length of pData not used
** nZero extra zeros after pData not used
** This object is used to pass information into sqlite3BtreeInsert(). The
** same information used to be passed as five separate parameters. But placing
** the information into this object helps to keep the interface more
** organized and understandable, and it also helps the resulting code to
** run a little faster by using fewer registers for parameter passing.
struct BtreePayload {
const void *pKey; /* Key content for indexes. NULL for tables */
sqlite3_int64 nKey; /* Size of pKey for indexes. PRIMARY KEY for tabs */
const void *pData; /* Data for tables. */
sqlite3_value *aMem; /* First of nMem value in the unpacked pKey */
u16 nMem; /* Number of aMem[] value. Might be zero */
int nData; /* Size of pData. 0 if none. */
int nZero; /* Extra zero data appended after pData,nData */
int sqlite3BtreeInsert(BtCursor*, const BtreePayload *pPayload,
int flags, int seekResult);
int sqlite3BtreeFirst(BtCursor*, int *pRes);
int sqlite3BtreeLast(BtCursor*, int *pRes);
int sqlite3BtreeNext(BtCursor*, int flags);
int sqlite3BtreeEof(BtCursor*);
int sqlite3BtreePrevious(BtCursor*, int flags);
i64 sqlite3BtreeIntegerKey(BtCursor*);
i64 sqlite3BtreeOffset(BtCursor*);
int sqlite3BtreePayload(BtCursor*, u32 offset, u32 amt, void*);
const void *sqlite3BtreePayloadFetch(BtCursor*, u32 *pAmt);
u32 sqlite3BtreePayloadSize(BtCursor*);
sqlite3_int64 sqlite3BtreeMaxRecordSize(BtCursor*);
char *sqlite3BtreeIntegrityCheck(Btree*, int *aRoot, int nRoot, int, int*);
struct Pager *sqlite3BtreePager(Btree*);
i64 sqlite3BtreeRowCountEst(BtCursor*);
int sqlite3BtreePayloadChecked(BtCursor*, u32 offset, u32 amt, void*);
int sqlite3BtreePutData(BtCursor*, u32 offset, u32 amt, void*);
void sqlite3BtreeIncrblobCursor(BtCursor *);
void sqlite3BtreeClearCursor(BtCursor *);
int sqlite3BtreeSetVersion(Btree *pBt, int iVersion);
int sqlite3BtreeCursorHasHint(BtCursor*, unsigned int mask);
int sqlite3BtreeIsReadonly(Btree *pBt);
int sqlite3HeaderSizeBtree(void);
#ifndef NDEBUG
int sqlite3BtreeCursorIsValid(BtCursor*);
int sqlite3BtreeCursorIsValidNN(BtCursor*);
int sqlite3BtreeCount(BtCursor *, i64 *);
int sqlite3BtreeCursorInfo(BtCursor*, int*, int);
void sqlite3BtreeCursorList(Btree*);
int sqlite3BtreeCheckpoint(Btree*, int, int *, int *);
** If we are not using shared cache, then there is no need to
** use mutexes to access the BtShared structures. So make the
** Enter and Leave procedures no-ops.
void sqlite3BtreeEnter(Btree*);
void sqlite3BtreeEnterAll(sqlite3*);
int sqlite3BtreeSharable(Btree*);
void sqlite3BtreeEnterCursor(BtCursor*);
int sqlite3BtreeConnectionCount(Btree*);
# define sqlite3BtreeEnter(X)
# define sqlite3BtreeEnterAll(X)
# define sqlite3BtreeSharable(X) 0
# define sqlite3BtreeEnterCursor(X)
# define sqlite3BtreeConnectionCount(X) 1
void sqlite3BtreeLeave(Btree*);
void sqlite3BtreeLeaveCursor(BtCursor*);
void sqlite3BtreeLeaveAll(sqlite3*);
#ifndef NDEBUG
/* These routines are used inside assert() statements only. */
int sqlite3BtreeHoldsMutex(Btree*);
int sqlite3BtreeHoldsAllMutexes(sqlite3*);
int sqlite3SchemaMutexHeld(sqlite3*,int,Schema*);
# define sqlite3BtreeLeave(X)
# define sqlite3BtreeLeaveCursor(X)
# define sqlite3BtreeLeaveAll(X)
# define sqlite3BtreeHoldsMutex(X) 1
# define sqlite3BtreeHoldsAllMutexes(X) 1
# define sqlite3SchemaMutexHeld(X,Y,Z) 1
#endif /* SQLITE_BTREE_H */