From 8b65cf4c5edabdcae45ceaef7b9ac236879aae50 Mon Sep 17 00:00:00 2001
From: Kevin Grittner <kgrittn@postgresql.org>
Date: Fri, 8 Apr 2016 14:30:10 -0500
Subject: 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.
---
 src/backend/access/gin/ginvacuum.c | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

(limited to 'src/backend/access/gin/ginvacuum.c')

diff --git a/src/backend/access/gin/ginvacuum.c b/src/backend/access/gin/ginvacuum.c
index 6a4b98a4e7e..f26dc799b5d 100644
--- a/src/backend/access/gin/ginvacuum.c
+++ b/src/backend/access/gin/ginvacuum.c
@@ -87,7 +87,8 @@ ginVacuumItemPointers(GinVacuumState *gvs, ItemPointerData *items,
 static void
 xlogVacuumPage(Relation index, Buffer buffer)
 {
-	Page		page = BufferGetPage(buffer);
+	Page		page = BufferGetPage(buffer, NULL, NULL,
+									 BGP_NO_SNAPSHOT_TEST);
 	XLogRecPtr	recptr;
 
 	/* This is only used for entry tree leaf pages. */
@@ -118,7 +119,7 @@ ginVacuumPostingTreeLeaves(GinVacuumState *gvs, BlockNumber blkno, bool isRoot,
 
 	buffer = ReadBufferExtended(gvs->index, MAIN_FORKNUM, blkno,
 								RBM_NORMAL, gvs->strategy);
-	page = BufferGetPage(buffer);
+	page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 	/*
 	 * We should be sure that we don't concurrent with inserts, insert process
@@ -212,14 +213,14 @@ ginDeletePage(GinVacuumState *gvs, BlockNumber deleteBlkno, BlockNumber leftBlkn
 	START_CRIT_SECTION();
 
 	/* Unlink the page by changing left sibling's rightlink */
-	page = BufferGetPage(dBuffer);
+	page = BufferGetPage(dBuffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 	rightlink = GinPageGetOpaque(page)->rightlink;
 
-	page = BufferGetPage(lBuffer);
+	page = BufferGetPage(lBuffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 	GinPageGetOpaque(page)->rightlink = rightlink;
 
 	/* Delete downlink from parent */
-	parentPage = BufferGetPage(pBuffer);
+	parentPage = BufferGetPage(pBuffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 #ifdef USE_ASSERT_CHECKING
 	do
 	{
@@ -230,7 +231,7 @@ ginDeletePage(GinVacuumState *gvs, BlockNumber deleteBlkno, BlockNumber leftBlkn
 #endif
 	GinPageDeletePostingItem(parentPage, myoff);
 
-	page = BufferGetPage(dBuffer);
+	page = BufferGetPage(dBuffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 	/*
 	 * we shouldn't change rightlink field to save workability of running
@@ -268,7 +269,8 @@ ginDeletePage(GinVacuumState *gvs, BlockNumber deleteBlkno, BlockNumber leftBlkn
 		recptr = XLogInsert(RM_GIN_ID, XLOG_GIN_DELETE_PAGE);
 		PageSetLSN(page, recptr);
 		PageSetLSN(parentPage, recptr);
-		PageSetLSN(BufferGetPage(lBuffer), recptr);
+		PageSetLSN(BufferGetPage(lBuffer, NULL, NULL,
+								 BGP_NO_SNAPSHOT_TEST), recptr);
 	}
 
 	if (!isParentRoot)
@@ -324,7 +326,7 @@ ginScanToDelete(GinVacuumState *gvs, BlockNumber blkno, bool isRoot,
 
 	buffer = ReadBufferExtended(gvs->index, MAIN_FORKNUM, blkno,
 								RBM_NORMAL, gvs->strategy);
-	page = BufferGetPage(buffer);
+	page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 	Assert(GinPageIsData(page));
 
@@ -407,7 +409,8 @@ ginVacuumPostingTree(GinVacuumState *gvs, BlockNumber rootBlkno)
 static Page
 ginVacuumEntryPage(GinVacuumState *gvs, Buffer buffer, BlockNumber *roots, uint32 *nroot)
 {
-	Page		origpage = BufferGetPage(buffer),
+	Page		origpage = BufferGetPage(buffer, NULL, NULL,
+										 BGP_NO_SNAPSHOT_TEST),
 				tmppage;
 	OffsetNumber i,
 				maxoff = PageGetMaxOffsetNumber(origpage);
@@ -554,7 +557,8 @@ ginbulkdelete(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
 	/* find leaf page */
 	for (;;)
 	{
-		Page		page = BufferGetPage(buffer);
+		Page		page = BufferGetPage(buffer, NULL, NULL,
+										 BGP_NO_SNAPSHOT_TEST);
 		IndexTuple	itup;
 
 		LockBuffer(buffer, GIN_SHARE);
@@ -589,7 +593,8 @@ ginbulkdelete(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
 
 	for (;;)
 	{
-		Page		page = BufferGetPage(buffer);
+		Page		page = BufferGetPage(buffer, NULL, NULL,
+										 BGP_NO_SNAPSHOT_TEST);
 		Page		resPage;
 		uint32		i;
 
@@ -703,7 +708,7 @@ ginvacuumcleanup(IndexVacuumInfo *info, IndexBulkDeleteResult *stats)
 		buffer = ReadBufferExtended(index, MAIN_FORKNUM, blkno,
 									RBM_NORMAL, info->strategy);
 		LockBuffer(buffer, GIN_SHARE);
-		page = (Page) BufferGetPage(buffer);
+		page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 		if (PageIsNew(page) || GinPageIsDeleted(page))
 		{
-- 
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