Revert no-op changes to BufferGetPage()

The reverted changes were intended to force a choice of whether any
newly-added BufferGetPage() calls needed to be accompanied by a
test of the snapshot age, to support the "snapshot too old"
feature.  Such an accompanying test is needed in about 7% of the
cases, where the page is being used as part of a scan rather than
positioning for other purposes (such as DML or vacuuming).  The
additional effort required for back-patching, and the doubt whether
the intended benefit would really be there, have indicated it is
best just to rely on developers to do the right thing based on
comments and existing usage, as we do with many other conventions.

This change should have little or no effect on generated executable
code.

Motivated by the back-patching pain of Tom Lane and Robert Haas

1 files changed, 23 insertions, 27 deletions

diff --git a/src/backend/access/spgist/spgxlog.c b/src/backend/access/spgist/spgxlog.c
index b5fc2663f03..01a4e0f2528 100644
--- a/src/backend/access/spgist/spgxlog.c
+++ b/src/backend/access/spgist/spgxlog.c
@@ -79,7 +79,7 @@ spgRedoCreateIndex(XLogReaderState *record)
 
 	buffer = XLogInitBufferForRedo(record, 0);
 	Assert(BufferGetBlockNumber(buffer) == SPGIST_METAPAGE_BLKNO);
-	page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+	page = (Page) BufferGetPage(buffer);
 	SpGistInitMetapage(page);
 	PageSetLSN(page, lsn);
 	MarkBufferDirty(buffer);
@@ -88,7 +88,7 @@ spgRedoCreateIndex(XLogReaderState *record)
 	buffer = XLogInitBufferForRedo(record, 1);
 	Assert(BufferGetBlockNumber(buffer) == SPGIST_ROOT_BLKNO);
 	SpGistInitBuffer(buffer, SPGIST_LEAF);
-	page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+	page = (Page) BufferGetPage(buffer);
 	PageSetLSN(page, lsn);
 	MarkBufferDirty(buffer);
 	UnlockReleaseBuffer(buffer);
@@ -96,7 +96,7 @@ spgRedoCreateIndex(XLogReaderState *record)
 	buffer = XLogInitBufferForRedo(record, 2);
 	Assert(BufferGetBlockNumber(buffer) == SPGIST_NULL_BLKNO);
 	SpGistInitBuffer(buffer, SPGIST_LEAF | SPGIST_NULLS);
-	page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+	page = (Page) BufferGetPage(buffer);
 	PageSetLSN(page, lsn);
 	MarkBufferDirty(buffer);
 	UnlockReleaseBuffer(buffer);
@@ -136,7 +136,7 @@ spgRedoAddLeaf(XLogReaderState *record)
 
 	if (action == BLK_NEEDS_REDO)
 	{
-		page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+		page = BufferGetPage(buffer);
 
 		/* insert new tuple */
 		if (xldata->offnumLeaf != xldata->offnumHeadLeaf)
@@ -183,7 +183,7 @@ spgRedoAddLeaf(XLogReaderState *record)
 
 			XLogRecGetBlockTag(record, 0, NULL, NULL, &blknoLeaf);
 
-			page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+			page = BufferGetPage(buffer);
 
 			tuple = (SpGistInnerTuple) PageGetItem(page,
 								  PageGetItemId(page, xldata->offnumParent));
@@ -249,7 +249,7 @@ spgRedoMoveLeafs(XLogReaderState *record)
 	{
 		int			i;
 
-		page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+		page = BufferGetPage(buffer);
 
 		for (i = 0; i < nInsert; i++)
 		{
@@ -278,7 +278,7 @@ spgRedoMoveLeafs(XLogReaderState *record)
 	/* Delete tuples from the source page, inserting a redirection pointer */
 	if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
 	{
-		page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+		page = BufferGetPage(buffer);
 
 		spgPageIndexMultiDelete(&state, page, toDelete, xldata->nMoves,
 						state.isBuild ? SPGIST_PLACEHOLDER : SPGIST_REDIRECT,
@@ -297,7 +297,7 @@ spgRedoMoveLeafs(XLogReaderState *record)
 	{
 		SpGistInnerTuple tuple;
 
-		page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+		page = BufferGetPage(buffer);
 
 		tuple = (SpGistInnerTuple) PageGetItem(page,
 								  PageGetItemId(page, xldata->offnumParent));
@@ -338,7 +338,7 @@ spgRedoAddNode(XLogReaderState *record)
 		Assert(xldata->parentBlk == -1);
 		if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
 		{
-			page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+			page = BufferGetPage(buffer);
 
 			PageIndexTupleDelete(page, xldata->offnum);
 			if (PageAddItem(page, (Item) innerTuple, innerTupleHdr.size,
@@ -381,7 +381,7 @@ spgRedoAddNode(XLogReaderState *record)
 			action = XLogReadBufferForRedo(record, 1, &buffer);
 		if (action == BLK_NEEDS_REDO)
 		{
-			page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+			page = BufferGetPage(buffer);
 
 			addOrReplaceTuple(page, (Item) innerTuple,
 							  innerTupleHdr.size, xldata->offnumNew);
@@ -410,7 +410,7 @@ spgRedoAddNode(XLogReaderState *record)
 		{
 			SpGistDeadTuple dt;
 
-			page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+			page = BufferGetPage(buffer);
 
 			if (state.isBuild)
 				dt = spgFormDeadTuple(&state, SPGIST_PLACEHOLDER,
@@ -462,7 +462,7 @@ spgRedoAddNode(XLogReaderState *record)
 			{
 				SpGistInnerTuple parentTuple;
 
-				page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+				page = BufferGetPage(buffer);
 
 				parentTuple = (SpGistInnerTuple) PageGetItem(page,
 								  PageGetItemId(page, xldata->offnumParent));
@@ -522,7 +522,7 @@ spgRedoSplitTuple(XLogReaderState *record)
 			action = XLogReadBufferForRedo(record, 1, &buffer);
 		if (action == BLK_NEEDS_REDO)
 		{
-			page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+			page = BufferGetPage(buffer);
 
 			addOrReplaceTuple(page, (Item) postfixTuple,
 							  postfixTupleHdr.size, xldata->offnumPostfix);
@@ -537,7 +537,7 @@ spgRedoSplitTuple(XLogReaderState *record)
 	/* now handle the original page */
 	if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
 	{
-		page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+		page = BufferGetPage(buffer);
 
 		PageIndexTupleDelete(page, xldata->offnumPrefix);
 		if (PageAddItem(page, (Item) prefixTuple, prefixTupleHdr.size,
@@ -608,7 +608,7 @@ spgRedoPickSplit(XLogReaderState *record)
 	{
 		/* just re-init the source page */
 		srcBuffer = XLogInitBufferForRedo(record, 0);
-		srcPage = BufferGetPage(srcBuffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+		srcPage = (Page) BufferGetPage(srcBuffer);
 
 		SpGistInitBuffer(srcBuffer,
 					 SPGIST_LEAF | (xldata->storesNulls ? SPGIST_NULLS : 0));
@@ -625,7 +625,7 @@ spgRedoPickSplit(XLogReaderState *record)
 		srcPage = NULL;
 		if (XLogReadBufferForRedo(record, 0, &srcBuffer) == BLK_NEEDS_REDO)
 		{
-			srcPage = BufferGetPage(srcBuffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+			srcPage = BufferGetPage(srcBuffer);
 
 			/*
 			 * We have it a bit easier here than in doPickSplit(), because we
@@ -661,8 +661,7 @@ spgRedoPickSplit(XLogReaderState *record)
 	{
 		/* just re-init the dest page */
 		destBuffer = XLogInitBufferForRedo(record, 1);
-		destPage = BufferGetPage(destBuffer, NULL, NULL,
-								 BGP_NO_SNAPSHOT_TEST);
+		destPage = (Page) BufferGetPage(destBuffer);
 
 		SpGistInitBuffer(destBuffer,
 					 SPGIST_LEAF | (xldata->storesNulls ? SPGIST_NULLS : 0));
@@ -675,8 +674,7 @@ spgRedoPickSplit(XLogReaderState *record)
 		 * full-page-image case, but for safety let's hold it till later.
 		 */
 		if (XLogReadBufferForRedo(record, 1, &destBuffer) == BLK_NEEDS_REDO)
-			destPage = BufferGetPage(destBuffer, NULL, NULL,
-									 BGP_NO_SNAPSHOT_TEST);
+			destPage = (Page) BufferGetPage(destBuffer);
 		else
 			destPage = NULL;	/* don't do any page updates */
 	}
@@ -724,7 +722,7 @@ spgRedoPickSplit(XLogReaderState *record)
 
 	if (action == BLK_NEEDS_REDO)
 	{
-		page = BufferGetPage(innerBuffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+		page = BufferGetPage(innerBuffer);
 
 		addOrReplaceTuple(page, (Item) innerTuple, innerTupleHdr.size,
 						  xldata->offnumInner);
@@ -764,8 +762,7 @@ spgRedoPickSplit(XLogReaderState *record)
 		{
 			SpGistInnerTuple parent;
 
-			page = BufferGetPage(parentBuffer, NULL, NULL,
-								 BGP_NO_SNAPSHOT_TEST);
+			page = BufferGetPage(parentBuffer);
 
 			parent = (SpGistInnerTuple) PageGetItem(page,
 								  PageGetItemId(page, xldata->offnumParent));
@@ -816,7 +813,7 @@ spgRedoVacuumLeaf(XLogReaderState *record)
 
 	if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
 	{
-		page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+		page = BufferGetPage(buffer);
 
 		spgPageIndexMultiDelete(&state, page,
 								toDead, xldata->nDead,
@@ -879,7 +876,7 @@ spgRedoVacuumRoot(XLogReaderState *record)
 
 	if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
 	{
-		page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+		page = BufferGetPage(buffer);
 
 		/* The tuple numbers are in order */
 		PageIndexMultiDelete(page, toDelete, xldata->nDelete);
@@ -920,8 +917,7 @@ spgRedoVacuumRedirect(XLogReaderState *record)
 
 	if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
 	{
-		Page		page = BufferGetPage(buffer, NULL, NULL,
-										 BGP_NO_SNAPSHOT_TEST);
+		Page		page = BufferGetPage(buffer);
 		SpGistPageOpaque opaque = SpGistPageGetOpaque(page);
 		int			i;