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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 page cache
** subsystem. The page cache subsystem reads and writes a file a page
** at a time and provides a journal for rollback.
*/
#ifndef SQLITE_PAGER_H
#define SQLITE_PAGER_H
/*
** Default maximum size for persistent journal files. A negative
** value means no limit. This value may be overridden using the
** sqlite3PagerJournalSizeLimit() API. See also "PRAGMA journal_size_limit".
*/
#ifndef SQLITE_DEFAULT_JOURNAL_SIZE_LIMIT
#define SQLITE_DEFAULT_JOURNAL_SIZE_LIMIT -1
#endif
/*
** The type used to represent a page number. The first page in a file
** is called page 1. 0 is used to represent "not a page".
*/
typedef u32 Pgno;
/*
** Each open file is managed by a separate instance of the "Pager" structure.
*/
typedef struct Pager Pager;
/*
** Handle type for pages.
*/
typedef struct PgHdr DbPage;
/*
** Page number PAGER_SJ_PGNO is never used in an SQLite database (it is
** reserved for working around a windows/posix incompatibility). It is
** used in the journal to signify that the remainder of the journal file
** is devoted to storing a super-journal name - there are no more pages to
** roll back. See comments for function writeSuperJournal() in pager.c
** for details.
*/
#define PAGER_SJ_PGNO_COMPUTED(x) ((Pgno)((PENDING_BYTE/((x)->pageSize))+1))
#define PAGER_SJ_PGNO(x) ((x)->lckPgno)
/*
** Allowed values for the flags parameter to sqlite3PagerOpen().
**
** NOTE: These values must match the corresponding BTREE_ values in btree.h.
*/
#define PAGER_OMIT_JOURNAL 0x0001 /* Do not use a rollback journal */
#define PAGER_MEMORY 0x0002 /* In-memory database */
/*
** Valid values for the second argument to sqlite3PagerLockingMode().
*/
#define PAGER_LOCKINGMODE_QUERY -1
#define PAGER_LOCKINGMODE_NORMAL 0
#define PAGER_LOCKINGMODE_EXCLUSIVE 1
/*
** Numeric constants that encode the journalmode.
**
** The numeric values encoded here (other than PAGER_JOURNALMODE_QUERY)
** are exposed in the API via the "PRAGMA journal_mode" command and
** therefore cannot be changed without a compatibility break.
*/
#define PAGER_JOURNALMODE_QUERY (-1) /* Query the value of journalmode */
#define PAGER_JOURNALMODE_DELETE 0 /* Commit by deleting journal file */
#define PAGER_JOURNALMODE_PERSIST 1 /* Commit by zeroing journal header */
#define PAGER_JOURNALMODE_OFF 2 /* Journal omitted. */
#define PAGER_JOURNALMODE_TRUNCATE 3 /* Commit by truncating journal */
#define PAGER_JOURNALMODE_MEMORY 4 /* In-memory journal file */
#define PAGER_JOURNALMODE_WAL 5 /* Use write-ahead logging */
/*
** Flags that make up the mask passed to sqlite3PagerGet().
*/
#define PAGER_GET_NOCONTENT 0x01 /* Do not load data from disk */
#define PAGER_GET_READONLY 0x02 /* Read-only page is acceptable */
/*
** Flags for sqlite3PagerSetFlags()
**
** Value constraints (enforced via assert()):
** PAGER_FULLFSYNC == SQLITE_FullFSync
** PAGER_CKPT_FULLFSYNC == SQLITE_CkptFullFSync
** PAGER_CACHE_SPILL == SQLITE_CacheSpill
*/
#define PAGER_SYNCHRONOUS_OFF 0x01 /* PRAGMA synchronous=OFF */
#define PAGER_SYNCHRONOUS_NORMAL 0x02 /* PRAGMA synchronous=NORMAL */
#define PAGER_SYNCHRONOUS_FULL 0x03 /* PRAGMA synchronous=FULL */
#define PAGER_SYNCHRONOUS_EXTRA 0x04 /* PRAGMA synchronous=EXTRA */
#define PAGER_SYNCHRONOUS_MASK 0x07 /* Mask for four values above */
#define PAGER_FULLFSYNC 0x08 /* PRAGMA fullfsync=ON */
#define PAGER_CKPT_FULLFSYNC 0x10 /* PRAGMA checkpoint_fullfsync=ON */
#define PAGER_CACHESPILL 0x20 /* PRAGMA cache_spill=ON */
#define PAGER_FLAGS_MASK 0x38 /* All above except SYNCHRONOUS */
/*
** The remainder of this file contains the declarations of the functions
** that make up the Pager sub-system API. See source code comments for
** a detailed description of each routine.
*/
/* Open and close a Pager connection. */
int sqlite3PagerOpen(
sqlite3_vfs*,
Pager **ppPager,
const char*,
int,
int,
int,
void(*)(DbPage*)
);
int sqlite3PagerClose(Pager *pPager, sqlite3*);
int sqlite3PagerReadFileheader(Pager*, int, unsigned char*);
/* Functions used to configure a Pager object. */
void sqlite3PagerSetBusyHandler(Pager*, int(*)(void *), void *);
int sqlite3PagerSetPagesize(Pager*, u32*, int);
Pgno sqlite3PagerMaxPageCount(Pager*, Pgno);
void sqlite3PagerSetCachesize(Pager*, int);
int sqlite3PagerSetSpillsize(Pager*, int);
void sqlite3PagerSetMmapLimit(Pager *, sqlite3_int64);
void sqlite3PagerShrink(Pager*);
void sqlite3PagerSetFlags(Pager*,unsigned);
int sqlite3PagerLockingMode(Pager *, int);
int sqlite3PagerSetJournalMode(Pager *, int);
int sqlite3PagerGetJournalMode(Pager*);
int sqlite3PagerOkToChangeJournalMode(Pager*);
i64 sqlite3PagerJournalSizeLimit(Pager *, i64);
sqlite3_backup **sqlite3PagerBackupPtr(Pager*);
int sqlite3PagerFlush(Pager*);
/* Functions used to obtain and release page references. */
int sqlite3PagerGet(Pager *pPager, Pgno pgno, DbPage **ppPage, int clrFlag);
DbPage *sqlite3PagerLookup(Pager *pPager, Pgno pgno);
void sqlite3PagerRef(DbPage*);
void sqlite3PagerUnref(DbPage*);
void sqlite3PagerUnrefNotNull(DbPage*);
void sqlite3PagerUnrefPageOne(DbPage*);
/* Operations on page references. */
int sqlite3PagerWrite(DbPage*);
void sqlite3PagerDontWrite(DbPage*);
int sqlite3PagerMovepage(Pager*,DbPage*,Pgno,int);
int sqlite3PagerPageRefcount(DbPage*);
void *sqlite3PagerGetData(DbPage *);
void *sqlite3PagerGetExtra(DbPage *);
/* Functions used to manage pager transactions and savepoints. */
void sqlite3PagerPagecount(Pager*, int*);
int sqlite3PagerBegin(Pager*, int exFlag, int);
int sqlite3PagerCommitPhaseOne(Pager*,const char *zSuper, int);
int sqlite3PagerExclusiveLock(Pager*);
int sqlite3PagerSync(Pager *pPager, const char *zSuper);
int sqlite3PagerCommitPhaseTwo(Pager*);
int sqlite3PagerRollback(Pager*);
int sqlite3PagerOpenSavepoint(Pager *pPager, int n);
int sqlite3PagerSavepoint(Pager *pPager, int op, int iSavepoint);
int sqlite3PagerSharedLock(Pager *pPager);
#ifndef SQLITE_OMIT_WAL
int sqlite3PagerCheckpoint(Pager *pPager, sqlite3*, int, int*, int*);
int sqlite3PagerWalSupported(Pager *pPager);
int sqlite3PagerWalCallback(Pager *pPager);
int sqlite3PagerOpenWal(Pager *pPager, int *pisOpen);
int sqlite3PagerCloseWal(Pager *pPager, sqlite3*);
# ifdef SQLITE_ENABLE_SNAPSHOT
int sqlite3PagerSnapshotGet(Pager*, sqlite3_snapshot **ppSnapshot);
int sqlite3PagerSnapshotOpen(Pager*, sqlite3_snapshot *pSnapshot);
int sqlite3PagerSnapshotRecover(Pager *pPager);
int sqlite3PagerSnapshotCheck(Pager *pPager, sqlite3_snapshot *pSnapshot);
void sqlite3PagerSnapshotUnlock(Pager *pPager);
# endif
#endif
#if !defined(SQLITE_OMIT_WAL) && defined(SQLITE_ENABLE_SETLK_TIMEOUT)
int sqlite3PagerWalWriteLock(Pager*, int);
void sqlite3PagerWalDb(Pager*, sqlite3*);
#else
# define sqlite3PagerWalWriteLock(y,z) SQLITE_OK
# define sqlite3PagerWalDb(x,y)
#endif
#ifdef SQLITE_DIRECT_OVERFLOW_READ
int sqlite3PagerDirectReadOk(Pager *pPager, Pgno pgno);
#endif
#ifdef SQLITE_ENABLE_ZIPVFS
int sqlite3PagerWalFramesize(Pager *pPager);
#endif
/* Functions used to query pager state and configuration. */
u8 sqlite3PagerIsreadonly(Pager*);
u32 sqlite3PagerDataVersion(Pager*);
#ifdef SQLITE_DEBUG
int sqlite3PagerRefcount(Pager*);
#endif
int sqlite3PagerMemUsed(Pager*);
const char *sqlite3PagerFilename(const Pager*, int);
sqlite3_vfs *sqlite3PagerVfs(Pager*);
sqlite3_file *sqlite3PagerFile(Pager*);
sqlite3_file *sqlite3PagerJrnlFile(Pager*);
const char *sqlite3PagerJournalname(Pager*);
void *sqlite3PagerTempSpace(Pager*);
int sqlite3PagerIsMemdb(Pager*);
void sqlite3PagerCacheStat(Pager *, int, int, u64*);
void sqlite3PagerClearCache(Pager*);
int sqlite3SectorSize(sqlite3_file *);
/* Functions used to truncate the database file. */
void sqlite3PagerTruncateImage(Pager*,Pgno);
void sqlite3PagerRekey(DbPage*, Pgno, u16);
/* Functions to support testing and debugging. */
#if !defined(NDEBUG) || defined(SQLITE_TEST)
Pgno sqlite3PagerPagenumber(DbPage*);
int sqlite3PagerIswriteable(DbPage*);
#endif
#ifdef SQLITE_TEST
int *sqlite3PagerStats(Pager*);
void sqlite3PagerRefdump(Pager*);
void disable_simulated_io_errors(void);
void enable_simulated_io_errors(void);
#else
# define disable_simulated_io_errors()
# define enable_simulated_io_errors()
#endif
#if defined(SQLITE_USE_SEH) && !defined(SQLITE_OMIT_WAL)
int sqlite3PagerWalSystemErrno(Pager*);
#endif
#endif /* SQLITE_PAGER_H */
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