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-rw-r--r--src/btree.c101
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.
*/