diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/btree.c | 13 | ||||
| -rw-r--r-- | src/btree.h | 8 | ||||
| -rw-r--r-- | src/pager.c | 13 | ||||
| -rw-r--r-- | src/pager.h | 1 | ||||
| -rw-r--r-- | src/pragma.c | 8 |
5 files changed, 39 insertions, 4 deletions
diff --git a/src/btree.c b/src/btree.c index d24f6a876..1223f78e4 100644 --- a/src/btree.c +++ b/src/btree.c @@ -8177,6 +8177,13 @@ int sqlite3BtreeDropTable(Btree *p, int iTable, int *piMoved){ ** The schema layer numbers meta values differently. At the schema ** layer (and the SetCookie and ReadCookie opcodes) the number of ** free pages is not visible. So Cookie[0] is the same as Meta[1]. +** +** This routine treats Meta[BTREE_DATA_VERSION] as a special case. Instead +** of reading the value out of the header, it instead loads the "DataVersion" +** from the pager. The BTREE_DATA_VERSION value is not actually stored in the +** database file. It is a number computed by the pager. But its access +** pattern is the same as header meta values, and so it is convenient to +** read it from this routine. */ void sqlite3BtreeGetMeta(Btree *p, int idx, u32 *pMeta){ BtShared *pBt = p->pBt; @@ -8187,7 +8194,11 @@ void sqlite3BtreeGetMeta(Btree *p, int idx, u32 *pMeta){ assert( pBt->pPage1 ); assert( idx>=0 && idx<=15 ); - *pMeta = get4byte(&pBt->pPage1->aData[36 + idx*4]); + if( idx==BTREE_DATA_VERSION ){ + *pMeta = sqlite3PagerDataVersion(pBt->pPager); + }else{ + *pMeta = get4byte(&pBt->pPage1->aData[36 + idx*4]); + } /* If auto-vacuum is disabled in this build and this is an auto-vacuum ** database, mark the database as read-only. */ diff --git a/src/btree.h b/src/btree.h index 281e57daf..b57d500c7 100644 --- a/src/btree.h +++ b/src/btree.h @@ -19,7 +19,7 @@ /* TODO: This definition is just included so other modules compile. It ** needs to be revisited. */ -#define SQLITE_N_BTREE_META 10 +#define SQLITE_N_BTREE_META 16 /* ** If defined as non-zero, auto-vacuum is enabled by default. Otherwise @@ -134,6 +134,11 @@ int sqlite3BtreeNewDb(Btree *p); ** 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_FREE_PAGE_COUNT 0 #define BTREE_SCHEMA_VERSION 1 @@ -144,6 +149,7 @@ int sqlite3BtreeNewDb(Btree *p); #define BTREE_USER_VERSION 6 #define BTREE_INCR_VACUUM 7 #define BTREE_APPLICATION_ID 8 +#define BTREE_DATA_VERSION 15 /* A virtual meta-value */ /* ** Values that may be OR'd together to form the second argument of an diff --git a/src/pager.c b/src/pager.c index a2ae9cc41..67b95f718 100644 --- a/src/pager.c +++ b/src/pager.c @@ -646,6 +646,7 @@ struct Pager { u8 setMaster; /* True if a m-j name has been written to jrnl */ u8 doNotSpill; /* Do not spill the cache when non-zero */ u8 subjInMemory; /* True to use in-memory sub-journals */ + u8 bUseFetch; /* True to use xFetch() */ Pgno dbSize; /* Number of pages in the database */ Pgno dbOrigSize; /* dbSize before the current transaction */ Pgno dbFileSize; /* Number of pages in the database file */ @@ -663,9 +664,9 @@ struct Pager { sqlite3_backup *pBackup; /* Pointer to list of ongoing backup processes */ PagerSavepoint *aSavepoint; /* Array of active savepoints */ int nSavepoint; /* Number of elements in aSavepoint[] */ + u32 iDataVersion; /* Changes whenever database content changes */ char dbFileVers[16]; /* Changes whenever database file changes */ - u8 bUseFetch; /* True to use xFetch() */ int nMmapOut; /* Number of mmap pages currently outstanding */ sqlite3_int64 szMmap; /* Desired maximum mmap size */ PgHdr *pMmapFreelist; /* List of free mmap page headers (pDirty) */ @@ -1681,11 +1682,20 @@ static int writeMasterJournal(Pager *pPager, const char *zMaster){ ** Discard the entire contents of the in-memory page-cache. */ static void pager_reset(Pager *pPager){ + pPager->iDataVersion++; sqlite3BackupRestart(pPager->pBackup); sqlite3PcacheClear(pPager->pPCache); } /* +** Return the pPager->iDataVersion value +*/ +u32 sqlite3PagerDataVersion(Pager *pPager){ + assert( pPager->eState>PAGER_OPEN ); + return pPager->iDataVersion; +} + +/* ** Free all structures in the Pager.aSavepoint[] array and set both ** Pager.aSavepoint and Pager.nSavepoint to zero. Close the sub-journal ** if it is open and the pager is not in exclusive mode. @@ -6307,6 +6317,7 @@ int sqlite3PagerCommitPhaseTwo(Pager *pPager){ } PAGERTRACE(("COMMIT %d\n", PAGERID(pPager))); + pPager->iDataVersion++; rc = pager_end_transaction(pPager, pPager->setMaster, 1); return pager_error(pPager, rc); } diff --git a/src/pager.h b/src/pager.h index 764c7bd19..e07fa88fc 100644 --- a/src/pager.h +++ b/src/pager.h @@ -172,6 +172,7 @@ int sqlite3PagerSharedLock(Pager *pPager); /* Functions used to query pager state and configuration. */ u8 sqlite3PagerIsreadonly(Pager*); +u32 sqlite3PagerDataVersion(Pager*); int sqlite3PagerRefcount(Pager*); int sqlite3PagerMemUsed(Pager*); const char *sqlite3PagerFilename(Pager*, int); diff --git a/src/pragma.c b/src/pragma.c index cbeb81eee..1312beef0 100644 --- a/src/pragma.c +++ b/src/pragma.c @@ -154,6 +154,12 @@ static const struct sPragmaNames { /* ePragFlag: */ 0, /* iArg: */ 0 }, #endif +#if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS) + { /* zName: */ "data_version", + /* ePragTyp: */ PragTyp_HEADER_VALUE, + /* ePragFlag: */ PragFlag_ReadOnly, + /* iArg: */ BTREE_DATA_VERSION }, +#endif #if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS) { /* zName: */ "database_list", /* ePragTyp: */ PragTyp_DATABASE_LIST, @@ -471,7 +477,7 @@ static const struct sPragmaNames { /* iArg: */ SQLITE_WriteSchema|SQLITE_RecoveryMode }, #endif }; -/* Number of pragmas: 57 on by default, 70 total. */ +/* Number of pragmas: 58 on by default, 71 total. */ /* End of the automatically generated pragma table. ***************************************************************************/ |