Fixed (I hope) unique btree index implementation.

diff --git a/src/backend/access/nbtree/nbtinsert.c b/src/backend/access/nbtree/nbtinsert.c
index 77410b8568da4ffc5e42f6787218c38e5598f4df..9804afab428d061054f7d3f162499e3940efc4d9 100644 (file)
--- a/src/backend/access/nbtree/nbtinsert.c
+++ b/src/backend/access/nbtree/nbtinsert.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtinsert.c,v 1.8 1996/12/06 09:45:30 vadim Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtinsert.c,v 1.9 1997/01/10 10:06:20 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -17,6 +17,7 @@
 #include <utils/memutils.h>
 #include <storage/bufpage.h>
 #include <access/nbtree.h>
+#include <access/heapam.h>
 #include <storage/bufmgr.h>
 
 #ifndef HAVE_MEMMOVE
@@ -41,7 +42,7 @@ static void _bt_updateitem(Relation rel, Size keysz, Buffer buf, Oid bti_oid, BT
  *     (xid, seqno) pair.
  */
 InsertIndexResult
-_bt_doinsert(Relation rel, BTItem btitem, bool index_is_unique, bool is_update)
+_bt_doinsert(Relation rel, BTItem btitem, bool index_is_unique, Relation heapRel)
 {
     ScanKey itup_scankey;
     IndexTuple itup;
@@ -60,30 +61,6 @@ _bt_doinsert(Relation rel, BTItem btitem, bool index_is_unique, bool is_update)
     /* find the page containing this key */
     stack = _bt_search(rel, natts, itup_scankey, &buf);
 
-    /* if we're not allowing duplicates, make sure the key isn't */
-    /* already in the node */
-    if(index_is_unique && !is_update) {
-       OffsetNumber offset;
-       TupleDesc itupdesc;
-       Page page;
-
-       itupdesc = RelationGetTupleDescriptor(rel);
-       page = BufferGetPage(buf);
-
-       offset = _bt_binsrch(rel, buf, natts, itup_scankey, BT_DESCENT);
-
-       /* make sure the offset we're given points to an actual */
-       /* key on the page before trying to compare it */
-       if(!PageIsEmpty(page) &&
-          offset <= PageGetMaxOffsetNumber(page)) {
-           if(!_bt_compare(rel, itupdesc, page, 
-                           natts, itup_scankey, offset)) {
-               /* it is a duplicate */
-               elog(WARN, "Cannot insert a duplicate key into a unique index.");
-           }
-       }
-    }
-
     blkno = BufferGetBlockNumber(buf);
     
     /* trade in our read lock for a write lock */
@@ -99,6 +76,91 @@ _bt_doinsert(Relation rel, BTItem btitem, bool index_is_unique, bool is_update)
      */
     
     buf = _bt_moveright(rel, buf, natts, itup_scankey, BT_WRITE);
+
+    /* if we're not allowing duplicates, make sure the key isn't */
+    /* already in the node */
+    if ( index_is_unique )
+    {
+       OffsetNumber offset, maxoff;
+       Page page;
+
+       page = BufferGetPage(buf);
+       maxoff = PageGetMaxOffsetNumber (page);
+
+       offset = _bt_binsrch(rel, buf, natts, itup_scankey, BT_DESCENT);
+
+       /* make sure the offset we're given points to an actual */
+       /* key on the page before trying to compare it */
+       if ( !PageIsEmpty (page) && offset <= maxoff )
+       {
+           TupleDesc itupdesc;
+           BTItem btitem;
+           IndexTuple itup;
+           HeapTuple htup;
+           BTPageOpaque opaque;
+           Buffer nbuf;
+           BlockNumber blkno;
+           
+           itupdesc = RelationGetTupleDescriptor(rel);
+           nbuf = InvalidBuffer;
+           opaque = (BTPageOpaque) PageGetSpecialPointer(page);
+           while ( !_bt_compare (rel, itupdesc, page, 
+                               natts, itup_scankey, offset) )
+           {   /* they're equal */
+               btitem = (BTItem) PageGetItem(page, PageGetItemId(page, offset));
+               itup = &(btitem->bti_itup);
+               htup = heap_fetch (heapRel, SelfTimeQual, &(itup->t_tid), NULL);
+               if ( htup != (HeapTuple) NULL )
+               {       /* it is a duplicate */
+                   elog(WARN, "Cannot insert a duplicate key into a unique index.");
+               }
+               /* get next offnum */
+               if ( offset < maxoff )
+               {
+                   offset = OffsetNumberNext(offset);
+               }
+               else
+               {       /* move right ? */
+                   if ( P_RIGHTMOST (opaque) )
+                       break;
+                   if ( _bt_compare (rel, itupdesc, page, 
+                               natts, itup_scankey, P_HIKEY) )
+                       break;
+                   /* 
+                    * min key of the right page is the same,
+                    * ooh - so many dead duplicates...
+                    */
+                   blkno = opaque->btpo_next;
+                   if ( nbuf != InvalidBuffer )
+                       _bt_relbuf (rel, nbuf, BT_READ);
+                   for (nbuf = InvalidBuffer; ; )
+                   {
+                       nbuf = _bt_getbuf (rel, blkno, BT_READ);
+                       page = BufferGetPage (nbuf);
+                       maxoff = PageGetMaxOffsetNumber(page);
+                       opaque = (BTPageOpaque) PageGetSpecialPointer(page);
+                       offset = P_RIGHTMOST(opaque) ? P_HIKEY : P_FIRSTKEY;
+                       if ( ! PageIsEmpty (page) && offset <= maxoff )
+                       {       /* Found some key */
+                           break;
+                       }
+                       else
+                       {       /* Empty or "pseudo"-empty page - get next */
+                           blkno = opaque->btpo_next;
+                           _bt_relbuf (rel, nbuf, BT_READ);
+                           nbuf = InvalidBuffer;
+                           if ( blkno == P_NONE )
+                               break;
+                       }
+                   }
+                   if ( nbuf == InvalidBuffer )
+                       break;
+               }
+           }
+           if ( nbuf != InvalidBuffer )
+               _bt_relbuf(rel, nbuf, BT_READ);
+       }
+    }
     
     /* do the insertion */
     res = _bt_insertonpg(rel, buf, stack, natts, itup_scankey,