Create new routines systable_beginscan_ordered, systable_getnext_ordered,

systable_endscan_ordered that have API similar to systable_beginscan etc
(in particular, the passed-in scankeys have heap not index attnums),
but guarantee ordered output, unlike the existing functions.  For the moment
these are just very thin wrappers around index_beginscan/index_getnext/etc.
Someday they might need to get smarter; but for now this is just a code
refactoring exercise to reduce the number of direct callers of index_getnext,
in preparation for changing that function's API.

In passing, remove index_getnext_indexitem, which has been dead code for
quite some time, and will have even less use than that in the presence
of run-time-lossy indexes.

1 files changed, 6 insertions, 5 deletions

diff --git a/src/backend/utils/cache/ts_cache.c b/src/backend/utils/cache/ts_cache.c
index 08ae22528a4..81ff577125e 100644
--- a/src/backend/utils/cache/ts_cache.c
+++ b/src/backend/utils/cache/ts_cache.c
@@ -20,7 +20,7 @@
  * Copyright (c) 2006-2008, PostgreSQL Global Development Group
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/cache/ts_cache.c,v 1.6 2008/03/26 21:10:39 alvherre Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/cache/ts_cache.c,v 1.7 2008/04/12 23:14:21 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -419,7 +419,7 @@ lookup_ts_config_cache(Oid cfgId)
 		Relation	maprel;
 		Relation	mapidx;
 		ScanKeyData mapskey;
-		IndexScanDesc mapscan;
+		SysScanDesc mapscan;
 		HeapTuple	maptup;
 		ListDictionary maplists[MAXTOKENTYPE + 1];
 		Oid			mapdicts[MAXDICTSPERTT];
@@ -488,9 +488,10 @@ lookup_ts_config_cache(Oid cfgId)
 
 		maprel = heap_open(TSConfigMapRelationId, AccessShareLock);
 		mapidx = index_open(TSConfigMapIndexId, AccessShareLock);
-		mapscan = index_beginscan(maprel, mapidx, SnapshotNow, 1, &mapskey);
+		mapscan = systable_beginscan_ordered(maprel, mapidx,
+											 SnapshotNow, 1, &mapskey);
 
-		while ((maptup = index_getnext(mapscan, ForwardScanDirection)) != NULL)
+		while ((maptup = systable_getnext_ordered(mapscan, ForwardScanDirection)) != NULL)
 		{
 			Form_pg_ts_config_map cfgmap = (Form_pg_ts_config_map) GETSTRUCT(maptup);
 			int			toktype = cfgmap->maptokentype;
@@ -524,7 +525,7 @@ lookup_ts_config_cache(Oid cfgId)
 			}
 		}
 
-		index_endscan(mapscan);
+		systable_endscan_ordered(mapscan);
 		index_close(mapidx, AccessShareLock);
 		heap_close(maprel, AccessShareLock);