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.

4 files changed, 14 insertions, 14 deletions

diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index cf8c8164b7e..8b41ab0828e 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -1025,7 +1025,7 @@ acquire_sample_rows(Relation onerel, int elevel,
 		targbuffer = ReadBufferExtended(onerel, MAIN_FORKNUM, targblock,
 										RBM_NORMAL, vac_strategy);
 		LockBuffer(targbuffer, BUFFER_LOCK_SHARE);
-		targpage = BufferGetPage(targbuffer);
+		targpage = BufferGetPage(targbuffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 		maxoffset = PageGetMaxOffsetNumber(targpage);
 
 		/* Inner loop over all tuples on the selected page */
diff --git a/src/backend/commands/sequence.c b/src/backend/commands/sequence.c
index c98f9811119..f38126f4f98 100644
--- a/src/backend/commands/sequence.c
+++ b/src/backend/commands/sequence.c
@@ -337,7 +337,7 @@ fill_seq_with_data(Relation rel, HeapTuple tuple)
 	buf = ReadBuffer(rel, P_NEW);
 	Assert(BufferGetBlockNumber(buf) == 0);
 
-	page = BufferGetPage(buf);
+	page = BufferGetPage(buf, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 	PageInit(page, BufferGetPageSize(buf), sizeof(sequence_magic));
 	sm = (sequence_magic *) PageGetSpecialPointer(page);
@@ -462,7 +462,7 @@ AlterSequence(AlterSeqStmt *stmt)
 	{
 		xl_seq_rec	xlrec;
 		XLogRecPtr	recptr;
-		Page		page = BufferGetPage(buf);
+		Page		page = BufferGetPage(buf, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 		XLogBeginInsert();
 		XLogRegisterBuffer(0, buf, REGBUF_WILL_INIT);
@@ -584,7 +584,7 @@ nextval_internal(Oid relid)
 
 	/* lock page' buffer and read tuple */
 	seq = read_seq_tuple(elm, seqrel, &buf, &seqtuple);
-	page = BufferGetPage(buf);
+	page = BufferGetPage(buf, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 	last = next = result = seq->last_value;
 	incby = seq->increment_by;
@@ -923,7 +923,7 @@ do_setval(Oid relid, int64 next, bool iscalled)
 	{
 		xl_seq_rec	xlrec;
 		XLogRecPtr	recptr;
-		Page		page = BufferGetPage(buf);
+		Page		page = BufferGetPage(buf, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 		XLogBeginInsert();
 		XLogRegisterBuffer(0, buf, REGBUF_WILL_INIT);
@@ -1115,7 +1115,7 @@ read_seq_tuple(SeqTable elm, Relation rel, Buffer *buf, HeapTuple seqtuple)
 	*buf = ReadBuffer(rel, 0);
 	LockBuffer(*buf, BUFFER_LOCK_EXCLUSIVE);
 
-	page = BufferGetPage(*buf);
+	page = BufferGetPage(*buf, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 	sm = (sequence_magic *) PageGetSpecialPointer(page);
 
 	if (sm->magic != SEQ_MAGIC)
@@ -1591,7 +1591,7 @@ seq_redo(XLogReaderState *record)
 		elog(PANIC, "seq_redo: unknown op code %u", info);
 
 	buffer = XLogInitBufferForRedo(record, 0);
-	page = (Page) BufferGetPage(buffer);
+	page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 	/*
 	 * We always reinit the page.  However, since this WAL record type is also
diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c
index 6f728ff0fc9..33107e02a9d 100644
--- a/src/backend/commands/trigger.c
+++ b/src/backend/commands/trigger.c
@@ -2798,7 +2798,7 @@ ltrmark:;
 		 */
 		LockBuffer(buffer, BUFFER_LOCK_SHARE);
 
-		page = BufferGetPage(buffer);
+		page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 		lp = PageGetItemId(page, ItemPointerGetOffsetNumber(tid));
 
 		Assert(ItemIdIsNormal(lp));
diff --git a/src/backend/commands/vacuumlazy.c b/src/backend/commands/vacuumlazy.c
index 52e19b30614..3f48ef40701 100644
--- a/src/backend/commands/vacuumlazy.c
+++ b/src/backend/commands/vacuumlazy.c
@@ -803,7 +803,7 @@ lazy_scan_heap(Relation onerel, LVRelStats *vacrelstats,
 
 		vacrelstats->scanned_pages++;
 
-		page = BufferGetPage(buf);
+		page = BufferGetPage(buf, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 		if (PageIsNew(page))
 		{
@@ -1378,7 +1378,7 @@ lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats)
 									&vmbuffer);
 
 		/* Now that we've compacted the page, record its available space */
-		page = BufferGetPage(buf);
+		page = BufferGetPage(buf, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 		freespace = PageGetHeapFreeSpace(page);
 
 		UnlockReleaseBuffer(buf);
@@ -1414,7 +1414,7 @@ static int
 lazy_vacuum_page(Relation onerel, BlockNumber blkno, Buffer buffer,
 				 int tupindex, LVRelStats *vacrelstats, Buffer *vmbuffer)
 {
-	Page		page = BufferGetPage(buffer);
+	Page		page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 	OffsetNumber unused[MaxOffsetNumber];
 	int			uncnt = 0;
 	TransactionId visibility_cutoff_xid;
@@ -1511,7 +1511,7 @@ lazy_vacuum_page(Relation onerel, BlockNumber blkno, Buffer buffer,
 static bool
 lazy_check_needs_freeze(Buffer buf, bool *hastup)
 {
-	Page		page = BufferGetPage(buf);
+	Page		page = BufferGetPage(buf, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 	OffsetNumber offnum,
 				maxoff;
 	HeapTupleHeader tupleheader;
@@ -1863,7 +1863,7 @@ count_nondeletable_pages(Relation onerel, LVRelStats *vacrelstats)
 		/* In this phase we only need shared access to the buffer */
 		LockBuffer(buf, BUFFER_LOCK_SHARE);
 
-		page = BufferGetPage(buf);
+		page = BufferGetPage(buf, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 		if (PageIsNew(page) || PageIsEmpty(page))
 		{
@@ -2031,7 +2031,7 @@ heap_page_is_all_visible(Relation rel, Buffer buf,
 						 TransactionId *visibility_cutoff_xid,
 						 bool *all_frozen)
 {
-	Page		page = BufferGetPage(buf);
+	Page		page = BufferGetPage(buf, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 	BlockNumber blockno = BufferGetBlockNumber(buf);
 	OffsetNumber offnum,
 				maxoff;