diff options
Diffstat (limited to 'src/btree.c')
| -rw-r--r-- | src/btree.c | 227 |
1 files changed, 7 insertions, 220 deletions
diff --git a/src/btree.c b/src/btree.c index d48f20880..b4a70bd97 100644 --- a/src/btree.c +++ b/src/btree.c @@ -9,7 +9,7 @@ ** May you share freely, never taking more than you give. ** ************************************************************************* -** $Id: btree.c,v 1.563 2009/01/31 14:54:07 danielk1977 Exp $ +** $Id: btree.c,v 1.564 2009/02/03 16:51:25 danielk1977 Exp $ ** ** This file implements a external (disk-based) database using BTrees. ** See the header comment on "btreeInt.h" for additional information. @@ -7239,225 +7239,6 @@ const char *sqlite3BtreeGetJournalname(Btree *p){ return sqlite3PagerJournalname(p->pBt->pPager); } -#ifndef SQLITE_OMIT_VACUUM -/* -** Copy the complete content of pBtFrom into pBtTo. A transaction -** must be active for both files. -** -** The size of file pTo may be reduced by this operation. -** If anything goes wrong, the transaction on pTo is rolled back. -** -** If successful, CommitPhaseOne() may be called on pTo before returning. -** The caller should finish committing the transaction on pTo by calling -** sqlite3BtreeCommit(). -*/ -static int btreeCopyFile(Btree *pTo, Btree *pFrom){ - int rc = SQLITE_OK; - Pgno i; - - Pgno nFromPage; /* Number of pages in pFrom */ - Pgno nToPage; /* Number of pages in pTo */ - Pgno nNewPage; /* Number of pages in pTo after the copy */ - - Pgno iSkip; /* Pending byte page in pTo */ - int nToPageSize; /* Page size of pTo in bytes */ - int nFromPageSize; /* Page size of pFrom in bytes */ - - BtShared *pBtTo = pTo->pBt; - BtShared *pBtFrom = pFrom->pBt; - pBtTo->db = pTo->db; - pBtFrom->db = pFrom->db; - - nToPageSize = pBtTo->pageSize; - nFromPageSize = pBtFrom->pageSize; - - assert( pTo->inTrans==TRANS_WRITE ); - assert( pFrom->inTrans==TRANS_WRITE ); - if( NEVER(pBtTo->pCursor) ){ - return SQLITE_BUSY; - } - - nToPage = pagerPagecount(pBtTo); - nFromPage = pagerPagecount(pBtFrom); - iSkip = PENDING_BYTE_PAGE(pBtTo); - - /* Variable nNewPage is the number of pages required to store the - ** contents of pFrom using the current page-size of pTo. - */ - nNewPage = (Pgno) - (((i64)nFromPage*(i64)nFromPageSize+(i64)nToPageSize-1)/(i64)nToPageSize); - - for(i=1; rc==SQLITE_OK && (i<=nToPage || i<=nNewPage); i++){ - - /* Journal the original page. - ** - ** iSkip is the page number of the locking page (PENDING_BYTE_PAGE) - ** in database *pTo (before the copy). This page is never written - ** into the journal file. Unless i==iSkip or the page was not - ** present in pTo before the copy operation, journal page i from pTo. - */ - if( i!=iSkip && i<=nToPage ){ - DbPage *pDbPage = 0; - rc = sqlite3PagerGet(pBtTo->pPager, i, &pDbPage); - if( rc==SQLITE_OK ){ - rc = sqlite3PagerWrite(pDbPage); - if( rc==SQLITE_OK && i>nFromPage ){ - /* Yeah. It seems wierd to call DontWrite() right after Write(). But - ** that is because the names of those procedures do not exactly - ** represent what they do. Write() really means "put this page in the - ** rollback journal and mark it as dirty so that it will be written - ** to the database file later." DontWrite() undoes the second part of - ** that and prevents the page from being written to the database. The - ** page is still on the rollback journal, though. And that is the - ** whole point of this block: to put pages on the rollback journal. - */ - sqlite3PagerDontWrite(pDbPage); - } - sqlite3PagerUnref(pDbPage); - } - } - - /* Overwrite the data in page i of the target database */ - if( rc==SQLITE_OK && i!=iSkip && i<=nNewPage ){ - - DbPage *pToPage = 0; - sqlite3_int64 iOff; - - rc = sqlite3PagerGet(pBtTo->pPager, i, &pToPage); - if( rc==SQLITE_OK ){ - rc = sqlite3PagerWrite(pToPage); - } - - for( - iOff=(i-1)*nToPageSize; - rc==SQLITE_OK && iOff<i*nToPageSize; - iOff += nFromPageSize - ){ - DbPage *pFromPage = 0; - Pgno iFrom = (Pgno)(iOff/nFromPageSize)+1; - - if( iFrom==PENDING_BYTE_PAGE(pBtFrom) ){ - continue; - } - - rc = sqlite3PagerGet(pBtFrom->pPager, iFrom, &pFromPage); - if( rc==SQLITE_OK ){ - char *zTo = sqlite3PagerGetData(pToPage); - char *zFrom = sqlite3PagerGetData(pFromPage); - int nCopy; - - if( nFromPageSize>=nToPageSize ){ - zFrom += ((i-1)*nToPageSize - ((iFrom-1)*nFromPageSize)); - nCopy = nToPageSize; - }else{ - zTo += (((iFrom-1)*nFromPageSize) - (i-1)*nToPageSize); - nCopy = nFromPageSize; - } - - memcpy(zTo, zFrom, nCopy); - sqlite3PagerUnref(pFromPage); - } - } - - if( pToPage ){ - MemPage *p = (MemPage *)sqlite3PagerGetExtra(pToPage); - p->isInit = 0; - sqlite3PagerUnref(pToPage); - } - } - } - - /* If things have worked so far, the database file may need to be - ** truncated. The complex part is that it may need to be truncated to - ** a size that is not an integer multiple of nToPageSize - the current - ** page size used by the pager associated with B-Tree pTo. - ** - ** For example, say the page-size of pTo is 2048 bytes and the original - ** number of pages is 5 (10 KB file). If pFrom has a page size of 1024 - ** bytes and 9 pages, then the file needs to be truncated to 9KB. - */ - if( rc==SQLITE_OK ){ - sqlite3_file *pFile = sqlite3PagerFile(pBtTo->pPager); - i64 iSize = (i64)nFromPageSize * (i64)nFromPage; - i64 iNow = (i64)((nToPage>nNewPage)?nToPage:nNewPage) * (i64)nToPageSize; - i64 iPending = ((i64)PENDING_BYTE_PAGE(pBtTo)-1) *(i64)nToPageSize; - - assert( iSize<=iNow ); - - /* Commit phase one syncs the journal file associated with pTo - ** containing the original data. It does not sync the database file - ** itself. After doing this it is safe to use OsTruncate() and other - ** file APIs on the database file directly. - */ - pBtTo->db = pTo->db; - if( nFromPageSize==nToPageSize ){ - sqlite3PagerTruncateImage(pBtTo->pPager, nFromPage); - iNow = iSize; - } - rc = sqlite3PagerCommitPhaseOne(pBtTo->pPager, 0, 1); - if( iSize<iNow && rc==SQLITE_OK ){ - rc = sqlite3OsTruncate(pFile, iSize); - } - - /* The loop that copied data from database pFrom to pTo did not - ** populate the locking page of database pTo. If the page-size of - ** pFrom is smaller than that of pTo, this means some data will - ** not have been copied. - ** - ** This block copies the missing data from database pFrom to pTo - ** using file APIs. This is safe because at this point we know that - ** all of the original data from pTo has been synced into the - ** journal file. At this point it would be safe to do anything at - ** all to the database file except truncate it to zero bytes. - */ - if( rc==SQLITE_OK && nFromPageSize<nToPageSize && iSize>iPending){ - i64 iOff; - for( - iOff=iPending; - rc==SQLITE_OK && iOff<(iPending+nToPageSize); - iOff += nFromPageSize - ){ - DbPage *pFromPage = 0; - Pgno iFrom = (Pgno)(iOff/nFromPageSize)+1; - - if( iFrom==PENDING_BYTE_PAGE(pBtFrom) || iFrom>nFromPage ){ - continue; - } - - rc = sqlite3PagerGet(pBtFrom->pPager, iFrom, &pFromPage); - if( rc==SQLITE_OK ){ - char *zFrom = sqlite3PagerGetData(pFromPage); - rc = sqlite3OsWrite(pFile, zFrom, nFromPageSize, iOff); - sqlite3PagerUnref(pFromPage); - } - } - } - } - - /* Sync the database file */ - if( rc==SQLITE_OK ){ - rc = sqlite3PagerSync(pBtTo->pPager); - } - if( rc==SQLITE_OK ){ - pBtTo->pageSizeFixed = 0; - }else{ - sqlite3BtreeRollback(pTo); - } - - return rc; -} -int sqlite3BtreeCopyFile(Btree *pTo, Btree *pFrom){ - int rc; - sqlite3BtreeEnter(pTo); - sqlite3BtreeEnter(pFrom); - rc = btreeCopyFile(pTo, pFrom); - sqlite3BtreeLeave(pFrom); - sqlite3BtreeLeave(pTo); - return rc; -} - -#endif /* SQLITE_OMIT_VACUUM */ - /* ** Return non-zero if a transaction is active. */ @@ -7483,6 +7264,12 @@ int sqlite3BtreeIsInReadTrans(Btree *p){ return p->inTrans!=TRANS_NONE; } +int sqlite3BtreeIsInBackup(Btree *p){ + assert( p ); + assert( sqlite3_mutex_held(p->db->mutex) ); + return p->nBackup!=0; +} + /* ** This function returns a pointer to a blob of memory associated with ** a single shared-btree. The memory is used by client code for its own |