Modify BufferGetPage() to prepare for "snapshot too old" feature

This patch is a no-op patch which is intended to reduce the chances
of failures of omission once the functional part of the "snapshot
too old" patch goes in.  It adds parameters for snapshot, relation,
and an enum to specify whether the snapshot age check needs to be
done for the page at this point.  This initial patch passes NULL
for the first two new parameters and BGP_NO_SNAPSHOT_TEST for the
third.  The follow-on patch will change the places where the test
needs to be made.

1 files changed, 8 insertions, 6 deletions

diff --git a/src/backend/access/gist/gistbuild.c b/src/backend/access/gist/gistbuild.c
index 4e43a6932a..8e7389c05f 100644
--- a/src/backend/access/gist/gistbuild.c
+++ b/src/backend/access/gist/gistbuild.c
@@ -169,7 +169,7 @@ gistbuild(Relation heap, Relation index, IndexInfo *indexInfo)
 	/* initialize the root page */
 	buffer = gistNewBuffer(index);
 	Assert(BufferGetBlockNumber(buffer) == GIST_ROOT_BLKNO);
-	page = BufferGetPage(buffer);
+	page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 	START_CRIT_SECTION();
 
@@ -589,7 +589,7 @@ gistProcessItup(GISTBuildState *buildstate, IndexTuple itup,
 		buffer = ReadBuffer(indexrel, blkno);
 		LockBuffer(buffer, GIST_EXCLUSIVE);
 
-		page = (Page) BufferGetPage(buffer);
+		page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 		childoffnum = gistchoose(indexrel, page, itup, giststate);
 		iid = PageGetItemId(page, childoffnum);
 		idxtuple = (IndexTuple) PageGetItem(page, iid);
@@ -699,7 +699,8 @@ gistbufferinginserttuples(GISTBuildState *buildstate, Buffer buffer, int level,
 	 */
 	if (is_split && BufferGetBlockNumber(buffer) == GIST_ROOT_BLKNO)
 	{
-		Page		page = BufferGetPage(buffer);
+		Page		page = BufferGetPage(buffer, NULL, NULL,
+										 BGP_NO_SNAPSHOT_TEST);
 		OffsetNumber off;
 		OffsetNumber maxoff;
 
@@ -866,7 +867,7 @@ gistBufferingFindCorrectParent(GISTBuildState *buildstate,
 	}
 
 	buffer = ReadBuffer(buildstate->indexrel, parent);
-	page = BufferGetPage(buffer);
+	page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 	LockBuffer(buffer, GIST_EXCLUSIVE);
 	gistcheckpage(buildstate->indexrel, buffer);
 	maxoff = PageGetMaxOffsetNumber(page);
@@ -1067,7 +1068,7 @@ gistGetMaxLevel(Relation index)
 		 * pro forma.
 		 */
 		LockBuffer(buffer, GIST_SHARE);
-		page = (Page) BufferGetPage(buffer);
+		page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 		if (GistPageIsLeaf(page))
 		{
@@ -1167,7 +1168,8 @@ gistMemorizeAllDownlinks(GISTBuildState *buildstate, Buffer parentbuf)
 	OffsetNumber maxoff;
 	OffsetNumber off;
 	BlockNumber parentblkno = BufferGetBlockNumber(parentbuf);
-	Page		page = BufferGetPage(parentbuf);
+	Page		page = BufferGetPage(parentbuf, NULL, NULL,
+									 BGP_NO_SNAPSHOT_TEST);
 
 	Assert(!GistPageIsLeaf(page));