diff options
Diffstat (limited to 'src/btree.c')
-rw-r--r-- | src/btree.c | 101 |
1 files changed, 100 insertions, 1 deletions
diff --git a/src/btree.c b/src/btree.c index 9745f6d90..a8fd80e4d 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 1.83 2003/02/12 14:09:43 drh Exp $ +** $Id: btree.c,v 1.84 2003/03/19 03:14:01 drh Exp $ ** ** This file implements a external (disk-based) database using BTrees. ** For a detailed discussion of BTrees, refer to @@ -2874,6 +2874,105 @@ int sqliteBtreeDropTable(Btree *pBt, int iTable){ return rc; } +#if 0 /* UNTESTED */ +/* +** Copy all cell data from one database file into another. +** pages back the freelist. +*/ +static int copyCell(Btree *pBtFrom, BTree *pBtTo, Cell *pCell){ + Pager *pFromPager = pBtFrom->pPager; + OverflowPage *pOvfl; + Pgno ovfl, nextOvfl; + Pgno *pPrev; + int rc = SQLITE_OK; + MemPage *pNew, *pPrevPg; + Pgno new; + + if( NKEY(pBtTo, pCell->h) + NDATA(pBtTo, pCell->h) <= MX_LOCAL_PAYLOAD ){ + return SQLITE_OK; + } + pPrev = &pCell->ovfl; + pPrevPg = 0; + ovfl = SWAB32(pBtTo, pCell->ovfl); + while( ovfl && rc==SQLITE_OK ){ + rc = sqlitepager_get(pFromPager, ovfl, (void**)&pOvfl); + if( rc ) return rc; + nextOvfl = SWAB32(pBtFrom, pOvfl->iNext); + rc = allocatePage(pBtTo, &pNew, &new, 0); + if( rc==SQLITE_OK ){ + rc = sqlitepager_write(pNew); + if( rc==SQLITE_OK ){ + memcpy(pNew, pOvfl, SQLITE_PAGE_SIZE); + *pPrev = SWAB32(pBtTo, new); + if( pPrevPg ){ + sqlitepager_unref(pPrevPg); + } + pPrev = &pOvfl->iNext; + pPrevPg = pNew; + } + } + sqlitepager_unref(pOvfl); + ovfl = nextOvfl; + } + if( pPrevPg ){ + sqlitepager_unref(pPrevPg); + } + return rc; +} +#endif + + +#if 0 /* UNTESTED */ +/* +** Copy a page of data from one database over to another. +*/ +static int copyDatabasePage( + Btree *pBtFrom, + Pgno pgnoFrom, + Btree *pBtTo, + Pgno *pTo +){ + MemPage *pPageFrom, *pPage; + Pgno to; + int rc; + Cell *pCell; + int idx; + + rc = sqlitepager_get(pBtFrom->pPager, pgno, (void**)&pPageFrom); + if( rc ) return rc; + rc = allocatePage(pBt, &pPage, pTo, 0); + if( rc==SQLITE_OK ){ + rc = sqlitepager_write(pPage); + } + if( rc==SQLITE_OK ){ + memcpy(pPage, pPageFrom, SQLITE_PAGE_SIZE); + idx = SWAB16(pBt, pPage->u.hdr.firstCell); + while( idx>0 ){ + pCell = (Cell*)&pPage->u.aDisk[idx]; + idx = SWAB16(pBt, pCell->h.iNext); + if( pCell->h.leftChild ){ + Pgno newChld; + rc = copyDatabasePage(pBtFrom, SWAB32(pBtFrom, pCell->h.leftChild), + pBtTo, &newChld); + if( rc ) return rc; + pCell->h.leftChild = SWAB32(pBtFrom, newChld); + } + rc = copyCell(pBtFrom, pBtTo, pCell); + if( rc ) return rc; + } + if( pPage->u.hdr.rightChild ){ + Pgno newChld; + rc = copyDatabasePage(pBtFrom, SWAB32(pBtFrom, pPage->u.hdr.rightChild), + pBtTo, &newChld); + if( rc ) return rc; + pPage->u.hdr.rightChild = SWAB32(pBtTo, newChild); + } + } + sqlitepager_unref(pPage); + return rc; +} +#endif + /* ** Read the meta-information out of a database file. */ |