166 lines
5.6 KiB
C
166 lines
5.6 KiB
C
/*
|
|
** 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 _PAGER_H_
|
|
#define _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_MJ_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 master journal name - there are no more pages to
|
|
** roll back. See comments for function writeMasterJournal() in pager.c
|
|
** for details.
|
|
*/
|
|
#define PAGER_MJ_PGNO(x) ((Pgno)((PENDING_BYTE/((x)->pageSize))+1))
|
|
|
|
/*
|
|
** 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_NO_READLOCK 0x0002 /* Omit readlocks on readonly files */
|
|
|
|
/*
|
|
** Valid values for the second argument to sqlite3PagerLockingMode().
|
|
*/
|
|
#define PAGER_LOCKINGMODE_QUERY -1
|
|
#define PAGER_LOCKINGMODE_NORMAL 0
|
|
#define PAGER_LOCKINGMODE_EXCLUSIVE 1
|
|
|
|
/*
|
|
** Valid values for the second argument to sqlite3PagerJournalMode().
|
|
*/
|
|
#define PAGER_JOURNALMODE_QUERY -1
|
|
#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 */
|
|
|
|
/*
|
|
** 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);
|
|
int sqlite3PagerReadFileheader(Pager*, int, unsigned char*);
|
|
|
|
/* Functions used to configure a Pager object. */
|
|
void sqlite3PagerSetBusyhandler(Pager*, int(*)(void *), void *);
|
|
int sqlite3PagerSetPagesize(Pager*, u16*, int);
|
|
int sqlite3PagerMaxPageCount(Pager*, int);
|
|
void sqlite3PagerSetCachesize(Pager*, int);
|
|
void sqlite3PagerSetSafetyLevel(Pager*,int,int);
|
|
int sqlite3PagerLockingMode(Pager *, int);
|
|
int sqlite3PagerJournalMode(Pager *, int);
|
|
i64 sqlite3PagerJournalSizeLimit(Pager *, i64);
|
|
sqlite3_backup **sqlite3PagerBackupPtr(Pager*);
|
|
|
|
/* Functions used to obtain and release page references. */
|
|
int sqlite3PagerAcquire(Pager *pPager, Pgno pgno, DbPage **ppPage, int clrFlag);
|
|
#define sqlite3PagerGet(A,B,C) sqlite3PagerAcquire(A,B,C,0)
|
|
DbPage *sqlite3PagerLookup(Pager *pPager, Pgno pgno);
|
|
void sqlite3PagerRef(DbPage*);
|
|
void sqlite3PagerUnref(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. */
|
|
int sqlite3PagerPagecount(Pager*, int*);
|
|
int sqlite3PagerBegin(Pager*, int exFlag, int);
|
|
int sqlite3PagerCommitPhaseOne(Pager*,const char *zMaster, int);
|
|
int sqlite3PagerSync(Pager *pPager);
|
|
int sqlite3PagerCommitPhaseTwo(Pager*);
|
|
int sqlite3PagerRollback(Pager*);
|
|
int sqlite3PagerOpenSavepoint(Pager *pPager, int n);
|
|
int sqlite3PagerSavepoint(Pager *pPager, int op, int iSavepoint);
|
|
int sqlite3PagerSharedLock(Pager *pPager);
|
|
|
|
/* Functions used to query pager state and configuration. */
|
|
u8 sqlite3PagerIsreadonly(Pager*);
|
|
int sqlite3PagerRefcount(Pager*);
|
|
const char *sqlite3PagerFilename(Pager*);
|
|
const sqlite3_vfs *sqlite3PagerVfs(Pager*);
|
|
sqlite3_file *sqlite3PagerFile(Pager*);
|
|
const char *sqlite3PagerJournalname(Pager*);
|
|
int sqlite3PagerNosync(Pager*);
|
|
void *sqlite3PagerTempSpace(Pager*);
|
|
int sqlite3PagerIsMemdb(Pager*);
|
|
|
|
/* Functions used to truncate the database file. */
|
|
void sqlite3PagerTruncateImage(Pager*,Pgno);
|
|
|
|
/* 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
|
|
|
|
#endif /* _PAGER_H_ */
|