Remove dependency on HeapTuple from predicate locking functions.

The following changes make the predicate locking functions more
generic and suitable for use by future access methods:

- PredicateLockTuple() is renamed to PredicateLockTID().  It takes
  ItemPointer and inserting transaction ID instead of HeapTuple.

- CheckForSerializableConflictIn() takes blocknum instead of buffer.

- CheckForSerializableConflictOut() no longer takes HeapTuple or buffer.

Author: Ashwin Agrawal
Reviewed-by: Andres Freund, Kuntal Ghosh, Thomas Munro
Discussion: https://postgr.es/m/CALfoeiv0k3hkEb3Oqk%3DziWqtyk2Jys1UOK5hwRBNeANT_yX%2Bng%40mail.gmail.com

2 files changed, 7 insertions, 4 deletions

diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h
index 00a17f5f717..47fda28daa1 100644
--- a/src/include/access/heapam.h
+++ b/src/include/access/heapam.h
@@ -220,5 +220,7 @@ extern bool ResolveCminCmaxDuringDecoding(struct HTAB *tuplecid_data,
 										  HeapTuple htup,
 										  Buffer buffer,
 										  CommandId *cmin, CommandId *cmax);
+extern void HeapCheckForSerializableConflictOut(bool valid, Relation relation, HeapTuple tuple,
+												Buffer buffer, Snapshot snapshot);
 
 #endif							/* HEAPAM_H */
diff --git a/src/include/storage/predicate.h b/src/include/storage/predicate.h
index a6cc1a1bf04..9df44ed0dc7 100644
--- a/src/include/storage/predicate.h
+++ b/src/include/storage/predicate.h
@@ -57,16 +57,17 @@ extern void SetSerializableTransactionSnapshot(Snapshot snapshot,
 extern void RegisterPredicateLockingXid(TransactionId xid);
 extern void PredicateLockRelation(Relation relation, Snapshot snapshot);
 extern void PredicateLockPage(Relation relation, BlockNumber blkno, Snapshot snapshot);
-extern void PredicateLockTuple(Relation relation, HeapTuple tuple, Snapshot snapshot);
+extern void PredicateLockTID(Relation relation, ItemPointer tid, Snapshot snapshot,
+							 TransactionId insert_xid);
 extern void PredicateLockPageSplit(Relation relation, BlockNumber oldblkno, BlockNumber newblkno);
 extern void PredicateLockPageCombine(Relation relation, BlockNumber oldblkno, BlockNumber newblkno);
 extern void TransferPredicateLocksToHeapRelation(Relation relation);
 extern void ReleasePredicateLocks(bool isCommit, bool isReadOnlySafe);
 
 /* conflict detection (may also trigger rollback) */
-extern void CheckForSerializableConflictOut(bool valid, Relation relation, HeapTuple tuple,
-											Buffer buffer, Snapshot snapshot);
-extern void CheckForSerializableConflictIn(Relation relation, HeapTuple tuple, Buffer buffer);
+extern bool CheckForSerializableConflictOutNeeded(Relation relation, Snapshot snapshot);
+extern void CheckForSerializableConflictOut(Relation relation, TransactionId xid, Snapshot snapshot);
+extern void CheckForSerializableConflictIn(Relation relation, ItemPointer tid, BlockNumber blkno);
 extern void CheckTableForSerializableConflictIn(Relation relation);
 
 /* final rollback checking */