diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backup.c | 29 |
1 files changed, 23 insertions, 6 deletions
diff --git a/src/backup.c b/src/backup.c index 31d14a0ae..cda0263a3 100644 --- a/src/backup.c +++ b/src/backup.c @@ -12,7 +12,7 @@ ** This file contains the implementation of the sqlite3_backup_XXX() ** API functions and the related features. ** -** $Id: backup.c,v 1.8 2009/02/06 05:59:44 danielk1977 Exp $ +** $Id: backup.c,v 1.9 2009/02/09 18:55:46 danielk1977 Exp $ */ #include "sqliteInt.h" #include "btreeInt.h" @@ -255,6 +255,23 @@ static int backupOnePage(sqlite3_backup *p, Pgno iSrcPg, const u8 *zSrcData){ } /* +** If pFile is currently larger than iSize bytes, then truncate it to +** exactly iSize bytes. If pFile is not larger than iSize bytes, then +** this function is a no-op. +** +** Return SQLITE_OK if everything is successful, or an SQLite error +** code if an error occurs. +*/ +static int backupTruncateFile(sqlite3_file *pFile, i64 iSize){ + i64 iCurrent; + int rc = sqlite3OsFileSize(pFile, &iCurrent); + if( rc==SQLITE_OK && iCurrent>iSize ){ + rc = sqlite3OsTruncate(pFile, iSize); + } + return rc; +} + +/* ** Copy nPage pages from the source b-tree to the destination. */ int sqlite3_backup_step(sqlite3_backup *p, int nPage){ @@ -330,8 +347,6 @@ int sqlite3_backup_step(sqlite3_backup *p, int nPage){ const int nSrcPagesize = sqlite3BtreeGetPageSize(p->pSrc); const int nDestPagesize = sqlite3BtreeGetPageSize(p->pDest); int nDestTruncate; - sqlite3_file *pFile = 0; - i64 iSize; /* Update the schema version field in the destination database. This ** is to make sure that the schema-version really does change in @@ -373,11 +388,13 @@ int sqlite3_backup_step(sqlite3_backup *p, int nPage){ ** pending-byte page in the source database may need to be ** copied into the destination database. */ - iSize = (i64)nSrcPagesize * (i64)nSrcPage; - pFile = sqlite3PagerFile(pDestPager); + const i64 iSize = (i64)nSrcPagesize * (i64)nSrcPage; + sqlite3_file * const pFile = sqlite3PagerFile(pDestPager); + assert( pFile ); + assert( (i64)nDestTruncate*(i64)nDestPagesize >= iSize ); if( SQLITE_OK==(rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 1)) - && SQLITE_OK==(rc = sqlite3OsTruncate(pFile, iSize)) + && SQLITE_OK==(rc = backupTruncateFile(pFile, iSize)) && SQLITE_OK==(rc = sqlite3PagerSync(pDestPager)) ){ i64 iOff; |