Restructure indexscan API (index_beginscan, index_getnext) per

yesterday's proposal to pghackers.  Also remove unnecessary parameters
to heap_beginscan, heap_rescan.  I modified pg_proc.h to reflect the
new numbers of parameters for the AM interface routines, but did not
force an initdb because nothing actually looks at those fields.

src/backend/access/rtree/rtget.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/rtree/Attic/rtget.c,v 1.25 2001/03/22 03:59:16 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/rtree/Attic/rtget.c,v 1.26 2002/05/20 23:51:41 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -21,10 +21,9 @@
 
 static OffsetNumber findnext(IndexScanDesc s, Page p, OffsetNumber n,
 		 ScanDirection dir);
-static RetrieveIndexResult rtscancache(IndexScanDesc s, ScanDirection dir);
-static RetrieveIndexResult rtfirst(IndexScanDesc s, ScanDirection dir);
-static RetrieveIndexResult rtnext(IndexScanDesc s, ScanDirection dir);
-static ItemPointer rtheapptr(Relation r, ItemPointer itemp);
+static bool rtscancache(IndexScanDesc s, ScanDirection dir);
+static bool rtfirst(IndexScanDesc s, ScanDirection dir);
+static bool rtnext(IndexScanDesc s, ScanDirection dir);
 
 
 Datum
@@ -32,35 +31,34 @@ rtgettuple(PG_FUNCTION_ARGS)
 {
 	IndexScanDesc s = (IndexScanDesc) PG_GETARG_POINTER(0);
 	ScanDirection dir = (ScanDirection) PG_GETARG_INT32(1);
-	RetrieveIndexResult res;
+	bool res;
 
 	/* if we have it cached in the scan desc, just return the value */
-	if ((res = rtscancache(s, dir)) != (RetrieveIndexResult) NULL)
-		PG_RETURN_POINTER(res);
+	if (rtscancache(s, dir))
+		PG_RETURN_BOOL(true);
 
 	/* not cached, so we'll have to do some work */
 	if (ItemPointerIsValid(&(s->currentItemData)))
 		res = rtnext(s, dir);
 	else
 		res = rtfirst(s, dir);
-	PG_RETURN_POINTER(res);
+	PG_RETURN_BOOL(res);
 }
 
-static RetrieveIndexResult
+static bool
 rtfirst(IndexScanDesc s, ScanDirection dir)
 {
 	Buffer		b;
 	Page		p;
 	OffsetNumber n;
 	OffsetNumber maxoff;
-	RetrieveIndexResult res;
 	RTreePageOpaque po;
 	RTreeScanOpaque so;
 	RTSTACK    *stk;
 	BlockNumber blk;
 	IndexTuple	it;
 
-	b = ReadBuffer(s->relation, P_ROOT);
+	b = ReadBuffer(s->indexRelation, P_ROOT);
 	p = BufferGetPage(b);
 	po = (RTreePageOpaque) PageGetSpecialPointer(p);
 	so = (RTreeScanOpaque) s->opaque;
@@ -75,13 +73,12 @@ rtfirst(IndexScanDesc s, ScanDirection dir)
 
 		while (n < FirstOffsetNumber || n > maxoff)
 		{
-
 			ReleaseBuffer(b);
 			if (so->s_stack == (RTSTACK *) NULL)
-				return (RetrieveIndexResult) NULL;
+				return false;
 
 			stk = so->s_stack;
-			b = ReadBuffer(s->relation, stk->rts_blk);
+			b = ReadBuffer(s->indexRelation, stk->rts_blk);
 			p = BufferGetPage(b);
 			po = (RTreePageOpaque) PageGetSpecialPointer(p);
 			maxoff = PageGetMaxOffsetNumber(p);
@@ -101,10 +98,10 @@ rtfirst(IndexScanDesc s, ScanDirection dir)
 
 			it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
 
-			res = FormRetrieveIndexResult(&(s->currentItemData), &(it->t_tid));
+			s->xs_ctup.t_self = it->t_tid;
 
 			ReleaseBuffer(b);
-			return res;
+			return true;
 		}
 		else
 		{
@@ -118,21 +115,20 @@ rtfirst(IndexScanDesc s, ScanDirection dir)
 			blk = ItemPointerGetBlockNumber(&(it->t_tid));
 
 			ReleaseBuffer(b);
-			b = ReadBuffer(s->relation, blk);
+			b = ReadBuffer(s->indexRelation, blk);
 			p = BufferGetPage(b);
 			po = (RTreePageOpaque) PageGetSpecialPointer(p);
 		}
 	}
 }
 
-static RetrieveIndexResult
+static bool
 rtnext(IndexScanDesc s, ScanDirection dir)
 {
 	Buffer		b;
 	Page		p;
 	OffsetNumber n;
 	OffsetNumber maxoff;
-	RetrieveIndexResult res;
 	RTreePageOpaque po;
 	RTreeScanOpaque so;
 	RTSTACK    *stk;
@@ -147,7 +143,7 @@ rtnext(IndexScanDesc s, ScanDirection dir)
 	else
 		n = OffsetNumberPrev(n);
 
-	b = ReadBuffer(s->relation, blk);
+	b = ReadBuffer(s->indexRelation, blk);
 	p = BufferGetPage(b);
 	po = (RTreePageOpaque) PageGetSpecialPointer(p);
 	so = (RTreeScanOpaque) s->opaque;
@@ -159,13 +155,12 @@ rtnext(IndexScanDesc s, ScanDirection dir)
 
 		while (n < FirstOffsetNumber || n > maxoff)
 		{
-
 			ReleaseBuffer(b);
 			if (so->s_stack == (RTSTACK *) NULL)
-				return (RetrieveIndexResult) NULL;
+				return false;
 
 			stk = so->s_stack;
-			b = ReadBuffer(s->relation, stk->rts_blk);
+			b = ReadBuffer(s->indexRelation, stk->rts_blk);
 			p = BufferGetPage(b);
 			maxoff = PageGetMaxOffsetNumber(p);
 			po = (RTreePageOpaque) PageGetSpecialPointer(p);
@@ -185,10 +180,10 @@ rtnext(IndexScanDesc s, ScanDirection dir)
 
 			it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
 
-			res = FormRetrieveIndexResult(&(s->currentItemData), &(it->t_tid));
+			s->xs_ctup.t_self = it->t_tid;
 
 			ReleaseBuffer(b);
-			return res;
+			return true;
 		}
 		else
 		{
@@ -202,7 +197,7 @@ rtnext(IndexScanDesc s, ScanDirection dir)
 			blk = ItemPointerGetBlockNumber(&(it->t_tid));
 
 			ReleaseBuffer(b);
-			b = ReadBuffer(s->relation, blk);
+			b = ReadBuffer(s->indexRelation, blk);
 			p = BufferGetPage(b);
 			po = (RTreePageOpaque) PageGetSpecialPointer(p);
 
@@ -243,14 +238,14 @@ findnext(IndexScanDesc s, Page p, OffsetNumber n, ScanDirection dir)
 		if (po->flags & F_LEAF)
 		{
 			if (index_keytest(it,
-							  RelationGetDescr(s->relation),
+							  RelationGetDescr(s->indexRelation),
 							  s->numberOfKeys, s->keyData))
 				break;
 		}
 		else
 		{
 			if (index_keytest(it,
-							  RelationGetDescr(s->relation),
+							  RelationGetDescr(s->indexRelation),
 							  so->s_internalNKey, so->s_internalKey))
 				break;
 		}
@@ -264,57 +259,25 @@ findnext(IndexScanDesc s, Page p, OffsetNumber n, ScanDirection dir)
 	return n;
 }
 
-static RetrieveIndexResult
+static bool
 rtscancache(IndexScanDesc s, ScanDirection dir)
-{
-	RetrieveIndexResult res;
-	ItemPointer ip;
-
-	if (!(ScanDirectionIsNoMovement(dir)
-		  && ItemPointerIsValid(&(s->currentItemData))))
-	{
-
-		return (RetrieveIndexResult) NULL;
-	}
-
-	ip = rtheapptr(s->relation, &(s->currentItemData));
-
-	if (ItemPointerIsValid(ip))
-		res = FormRetrieveIndexResult(&(s->currentItemData), ip);
-	else
-		res = (RetrieveIndexResult) NULL;
-
-	pfree(ip);
-
-	return res;
-}
-
-/*
- *	rtheapptr returns the item pointer to the tuple in the heap relation
- *	for which itemp is the index relation item pointer.
- */
-static ItemPointer
-rtheapptr(Relation r, ItemPointer itemp)
 {
 	Buffer		b;
 	Page		p;
-	IndexTuple	it;
-	ItemPointer ip;
 	OffsetNumber n;
+	IndexTuple	it;
 
-	ip = (ItemPointer) palloc(sizeof(ItemPointerData));
-	if (ItemPointerIsValid(itemp))
-	{
-		b = ReadBuffer(r, ItemPointerGetBlockNumber(itemp));
-		p = BufferGetPage(b);
-		n = ItemPointerGetOffsetNumber(itemp);
-		it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
-		memmove((char *) ip, (char *) &(it->t_tid),
-				sizeof(ItemPointerData));
-		ReleaseBuffer(b);
-	}
-	else
-		ItemPointerSetInvalid(ip);
+	if (!(ScanDirectionIsNoMovement(dir)
+		  && ItemPointerIsValid(&(s->currentItemData))))
+		return false;
 
-	return ip;
+	b = ReadBuffer(s->indexRelation,
+				   ItemPointerGetBlockNumber(&(s->currentItemData)));
+	p = BufferGetPage(b);
+	n = ItemPointerGetOffsetNumber(&(s->currentItemData));
+	it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
+	s->xs_ctup.t_self = it->t_tid;
+	ReleaseBuffer(b);
+
+	return true;
 }

src/backend/access/rtree/rtree.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/rtree/Attic/rtree.c,v 1.70 2002/03/02 21:39:19 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/rtree/Attic/rtree.c,v 1.71 2002/05/20 23:51:41 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1189,7 +1189,6 @@ rtbulkdelete(PG_FUNCTION_ARGS)
 	BlockNumber num_pages;
 	double		tuples_removed;
 	double		num_index_tuples;
-	RetrieveIndexResult res;
 	IndexScanDesc iscan;
 
 	tuples_removed = 0;
@@ -1206,23 +1205,20 @@ rtbulkdelete(PG_FUNCTION_ARGS)
 	 */
 
 	/* walk through the entire index */
-	iscan = index_beginscan(rel, false, 0, (ScanKey) NULL);
+	iscan = index_beginscan(NULL, rel, SnapshotAny, 0, (ScanKey) NULL);
 
-	while ((res = index_getnext(iscan, ForwardScanDirection))
-		   != (RetrieveIndexResult) NULL)
+	while (index_getnext_indexitem(iscan, ForwardScanDirection))
 	{
-		ItemPointer heapptr = &res->heap_iptr;
-
-		if (callback(heapptr, callback_state))
+		if (callback(&iscan->xs_ctup.t_self, callback_state))
 		{
-			ItemPointer indexptr = &res->index_iptr;
+			ItemPointerData indextup = iscan->currentItemData;
 			BlockNumber blkno;
 			OffsetNumber offnum;
 			Buffer		buf;
 			Page		page;
 
-			blkno = ItemPointerGetBlockNumber(indexptr);
-			offnum = ItemPointerGetOffsetNumber(indexptr);
+			blkno = ItemPointerGetBlockNumber(&indextup);
+			offnum = ItemPointerGetOffsetNumber(&indextup);
 
 			/* adjust any scans that will be affected by this deletion */
 			/* (namely, my own scan) */
@@ -1240,8 +1236,6 @@ rtbulkdelete(PG_FUNCTION_ARGS)
 		}
 		else
 			num_index_tuples += 1;
-
-		pfree(res);
 	}
 
 	index_endscan(iscan);

src/backend/access/rtree/rtscan.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/rtree/Attic/rtscan.c,v 1.40 2002/03/05 05:30:40 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/rtree/Attic/rtscan.c,v 1.41 2002/05/20 23:51:41 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -54,12 +54,11 @@ Datum
 rtbeginscan(PG_FUNCTION_ARGS)
 {
 	Relation	r = (Relation) PG_GETARG_POINTER(0);
-	bool		fromEnd = PG_GETARG_BOOL(1);
-	uint16		nkeys = PG_GETARG_UINT16(2);
-	ScanKey		key = (ScanKey) PG_GETARG_POINTER(3);
+	int			nkeys = PG_GETARG_INT32(1);
+	ScanKey		key = (ScanKey) PG_GETARG_POINTER(2);
 	IndexScanDesc s;
 
-	s = RelationGetIndexScan(r, fromEnd, nkeys, key);
+	s = RelationGetIndexScan(r, nkeys, key);
 
 	rtregscan(s);
 
@@ -70,8 +69,7 @@ Datum
 rtrescan(PG_FUNCTION_ARGS)
 {
 	IndexScanDesc s = (IndexScanDesc) PG_GETARG_POINTER(0);
-	bool		fromEnd = PG_GETARG_BOOL(1);
-	ScanKey		key = (ScanKey) PG_GETARG_POINTER(2);
+	ScanKey		key = (ScanKey) PG_GETARG_POINTER(1);
 	RTreeScanOpaque p;
 	RegProcedure internal_proc;
 	int			i;
@@ -82,18 +80,6 @@ rtrescan(PG_FUNCTION_ARGS)
 	ItemPointerSetInvalid(&s->currentItemData);
 	ItemPointerSetInvalid(&s->currentMarkData);
 
-	/*
-	 * Set flags.
-	 */
-	if (RelationGetNumberOfBlocks(s->relation) == 0)
-		s->flags = ScanUnmarked;
-	else if (fromEnd)
-		s->flags = ScanUnmarked | ScanUncheckedPrevious;
-	else
-		s->flags = ScanUnmarked | ScanUncheckedNext;
-
-	s->scanFromEnd = fromEnd;
-
 	if (s->numberOfKeys > 0)
 	{
 		memmove(s->keyData,
@@ -133,7 +119,7 @@ rtrescan(PG_FUNCTION_ARGS)
 			for (i = 0; i < s->numberOfKeys; i++)
 			{
 				p->s_internalKey[i].sk_argument = s->keyData[i].sk_argument;
-				internal_proc = RTMapOperator(s->relation,
+				internal_proc = RTMapOperator(s->indexRelation,
 											  s->keyData[i].sk_attno,
 											  s->keyData[i].sk_procedure);
 				ScanKeyEntryInitialize(&(p->s_internalKey[i]),
@@ -306,7 +292,7 @@ rtadjscans(Relation r, int op, BlockNumber blkno, OffsetNumber offnum)
 	relid = RelationGetRelid(r);
 	for (l = RTScans; l != (RTScanList) NULL; l = l->rtsl_next)
 	{
-		if (RelationGetRelid(l->rtsl_scan->relation) == relid)
+		if (RelationGetRelid(l->rtsl_scan->indexRelation) == relid)
 			rtadjone(l->rtsl_scan, op, blkno, offnum);
 	}
 }