| Index: third_party/sqlite/src/src/pcache.h
|
| diff --git a/third_party/sqlite/src/src/pcache.h b/third_party/sqlite/src/src/pcache.h
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..33735d2cbb2dc159ca988e91f90b8658f91e5394
|
| --- /dev/null
|
| +++ b/third_party/sqlite/src/src/pcache.h
|
| @@ -0,0 +1,155 @@
|
| +/*
|
| +** 2008 August 05
|
| +**
|
| +** 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.
|
| +*/
|
| +
|
| +#ifndef _PCACHE_H_
|
| +
|
| +typedef struct PgHdr PgHdr;
|
| +typedef struct PCache PCache;
|
| +
|
| +/*
|
| +** Every page in the cache is controlled by an instance of the following
|
| +** structure.
|
| +*/
|
| +struct PgHdr {
|
| + void *pData; /* Content of this page */
|
| + void *pExtra; /* Extra content */
|
| + PgHdr *pDirty; /* Transient list of dirty pages */
|
| + Pgno pgno; /* Page number for this page */
|
| + Pager *pPager; /* The pager this page is part of */
|
| +#ifdef SQLITE_CHECK_PAGES
|
| + u32 pageHash; /* Hash of page content */
|
| +#endif
|
| + u16 flags; /* PGHDR flags defined below */
|
| +
|
| + /**********************************************************************
|
| + ** Elements above are public. All that follows is private to pcache.c
|
| + ** and should not be accessed by other modules.
|
| + */
|
| + i16 nRef; /* Number of users of this page */
|
| + PCache *pCache; /* Cache that owns this page */
|
| +
|
| + PgHdr *pDirtyNext; /* Next element in list of dirty pages */
|
| + PgHdr *pDirtyPrev; /* Previous element in list of dirty pages */
|
| +};
|
| +
|
| +/* Bit values for PgHdr.flags */
|
| +#define PGHDR_DIRTY 0x002 /* Page has changed */
|
| +#define PGHDR_NEED_SYNC 0x004 /* Fsync the rollback journal before
|
| + ** writing this page to the database */
|
| +#define PGHDR_NEED_READ 0x008 /* Content is unread */
|
| +#define PGHDR_REUSE_UNLIKELY 0x010 /* A hint that reuse is unlikely */
|
| +#define PGHDR_DONT_WRITE 0x020 /* Do not write content to disk */
|
| +
|
| +/* Initialize and shutdown the page cache subsystem */
|
| +int sqlite3PcacheInitialize(void);
|
| +void sqlite3PcacheShutdown(void);
|
| +
|
| +/* Page cache buffer management:
|
| +** These routines implement SQLITE_CONFIG_PAGECACHE.
|
| +*/
|
| +void sqlite3PCacheBufferSetup(void *, int sz, int n);
|
| +
|
| +/* Create a new pager cache.
|
| +** Under memory stress, invoke xStress to try to make pages clean.
|
| +** Only clean and unpinned pages can be reclaimed.
|
| +*/
|
| +void sqlite3PcacheOpen(
|
| + int szPage, /* Size of every page */
|
| + int szExtra, /* Extra space associated with each page */
|
| + int bPurgeable, /* True if pages are on backing store */
|
| + int (*xStress)(void*, PgHdr*), /* Call to try to make pages clean */
|
| + void *pStress, /* Argument to xStress */
|
| + PCache *pToInit /* Preallocated space for the PCache */
|
| +);
|
| +
|
| +/* Modify the page-size after the cache has been created. */
|
| +void sqlite3PcacheSetPageSize(PCache *, int);
|
| +
|
| +/* Return the size in bytes of a PCache object. Used to preallocate
|
| +** storage space.
|
| +*/
|
| +int sqlite3PcacheSize(void);
|
| +
|
| +/* One release per successful fetch. Page is pinned until released.
|
| +** Reference counted.
|
| +*/
|
| +int sqlite3PcacheFetch(PCache*, Pgno, int createFlag, PgHdr**);
|
| +void sqlite3PcacheRelease(PgHdr*);
|
| +
|
| +void sqlite3PcacheDrop(PgHdr*); /* Remove page from cache */
|
| +void sqlite3PcacheMakeDirty(PgHdr*); /* Make sure page is marked dirty */
|
| +void sqlite3PcacheMakeClean(PgHdr*); /* Mark a single page as clean */
|
| +void sqlite3PcacheCleanAll(PCache*); /* Mark all dirty list pages as clean */
|
| +
|
| +/* Change a page number. Used by incr-vacuum. */
|
| +void sqlite3PcacheMove(PgHdr*, Pgno);
|
| +
|
| +/* Remove all pages with pgno>x. Reset the cache if x==0 */
|
| +void sqlite3PcacheTruncate(PCache*, Pgno x);
|
| +
|
| +/* Get a list of all dirty pages in the cache, sorted by page number */
|
| +PgHdr *sqlite3PcacheDirtyList(PCache*);
|
| +
|
| +/* Reset and close the cache object */
|
| +void sqlite3PcacheClose(PCache*);
|
| +
|
| +/* Clear flags from pages of the page cache */
|
| +void sqlite3PcacheClearSyncFlags(PCache *);
|
| +
|
| +/* Discard the contents of the cache */
|
| +void sqlite3PcacheClear(PCache*);
|
| +
|
| +/* Return the total number of outstanding page references */
|
| +int sqlite3PcacheRefCount(PCache*);
|
| +
|
| +/* Increment the reference count of an existing page */
|
| +void sqlite3PcacheRef(PgHdr*);
|
| +
|
| +int sqlite3PcachePageRefcount(PgHdr*);
|
| +
|
| +/* Return the total number of pages stored in the cache */
|
| +int sqlite3PcachePagecount(PCache*);
|
| +
|
| +#if defined(SQLITE_CHECK_PAGES) || defined(SQLITE_DEBUG)
|
| +/* Iterate through all dirty pages currently stored in the cache. This
|
| +** interface is only available if SQLITE_CHECK_PAGES is defined when the
|
| +** library is built.
|
| +*/
|
| +void sqlite3PcacheIterateDirty(PCache *pCache, void (*xIter)(PgHdr *));
|
| +#endif
|
| +
|
| +/* Set and get the suggested cache-size for the specified pager-cache.
|
| +**
|
| +** If no global maximum is configured, then the system attempts to limit
|
| +** the total number of pages cached by purgeable pager-caches to the sum
|
| +** of the suggested cache-sizes.
|
| +*/
|
| +void sqlite3PcacheSetCachesize(PCache *, int);
|
| +#ifdef SQLITE_TEST
|
| +int sqlite3PcacheGetCachesize(PCache *);
|
| +#endif
|
| +
|
| +#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
|
| +/* Try to return memory used by the pcache module to the main memory heap */
|
| +int sqlite3PcacheReleaseMemory(int);
|
| +#endif
|
| +
|
| +#ifdef SQLITE_TEST
|
| +void sqlite3PcacheStats(int*,int*,int*,int*);
|
| +#endif
|
| +
|
| +void sqlite3PCacheSetDefault(void);
|
| +
|
| +#endif /* _PCACHE_H_ */
|
|
|