Add macros in hash and btree AMs to get the special area of their pages

This makes the code more consistent with SpGiST, GiST and GIN, that
already use this style, and the idea is to make easier the introduction
of more sanity checks for each of these AM-specific macros.  BRIN uses a
different set of macros to get a page's type and flags, so it has no
need for something similar.

Author: Matthias van de Meent
Discussion: https://postgr.es/m/CAEze2WjE3+tGO9Fs9+iZMU+z6mMZKo54W1Zt98WKqbEUHbHOBg@mail.gmail.com

1 files changed, 3 insertions, 3 deletions

diff --git a/src/backend/access/nbtree/nbtutils.c b/src/backend/access/nbtree/nbtutils.c
index 84164748b3e..96c72fc4324 100644
--- a/src/backend/access/nbtree/nbtutils.c
+++ b/src/backend/access/nbtree/nbtutils.c
@@ -1774,7 +1774,7 @@ _bt_killitems(IndexScanDesc scan)
 		}
 	}
 
-	opaque = (BTPageOpaque) PageGetSpecialPointer(page);
+	opaque = BTPageGetOpaque(page);
 	minoff = P_FIRSTDATAKEY(opaque);
 	maxoff = PageGetMaxOffsetNumber(page);
 
@@ -2474,7 +2474,7 @@ _bt_check_natts(Relation rel, bool heapkeyspace, Page page, OffsetNumber offnum)
 {
 	int16		natts = IndexRelationGetNumberOfAttributes(rel);
 	int16		nkeyatts = IndexRelationGetNumberOfKeyAttributes(rel);
-	BTPageOpaque opaque = (BTPageOpaque) PageGetSpecialPointer(page);
+	BTPageOpaque opaque = BTPageGetOpaque(page);
 	IndexTuple	itup;
 	int			tupnatts;
 
@@ -2662,7 +2662,7 @@ _bt_check_third_page(Relation rel, Relation heap, bool needheaptidspace,
 	 * Internal page insertions cannot fail here, because that would mean that
 	 * an earlier leaf level insertion that should have failed didn't
 	 */
-	opaque = (BTPageOpaque) PageGetSpecialPointer(page);
+	opaque = BTPageGetOpaque(page);
 	if (!P_ISLEAF(opaque))
 		elog(ERROR, "cannot insert oversized tuple of size %zu on internal page of index \"%s\"",
 			 itemsz, RelationGetRelationName(rel));