Wrap calls to SearchSysCache and related functions using macros.

The purpose of this change is to eliminate the need for every caller
of SearchSysCache, SearchSysCacheCopy, SearchSysCacheExists,
GetSysCacheOid, and SearchSysCacheList to know the maximum number
of allowable keys for a syscache entry (currently 4).  This will
make it far easier to increase the maximum number of keys in a
future release should we choose to do so, and it makes the code
shorter, too.

Design and review by Tom Lane.

1 files changed, 51 insertions, 1 deletions

diff --git a/src/include/utils/syscache.h b/src/include/utils/syscache.h
index 8cdd7e79ee1..9faefbe8d7a 100644
--- a/src/include/utils/syscache.h
+++ b/src/include/utils/syscache.h
@@ -9,7 +9,7 @@
  * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/utils/syscache.h,v 1.78 2010/01/05 21:54:00 rhaas Exp $
+ * $PostgreSQL: pgsql/src/include/utils/syscache.h,v 1.79 2010/02/14 18:42:18 rhaas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -113,6 +113,56 @@ extern Datum SysCacheGetAttr(int cacheId, HeapTuple tup,
 extern struct catclist *SearchSysCacheList(int cacheId, int nkeys,
 				   Datum key1, Datum key2, Datum key3, Datum key4);
 
+/*
+ * The use of the macros below rather than direct calls to the corresponding
+ * functions is encouraged, as it insulates the caller from changes in the
+ * maximum number of keys.
+ */
+#define SearchSysCache1(cacheId, key1) \
+	SearchSysCache(cacheId, key1, 0, 0, 0)
+#define SearchSysCache2(cacheId, key1, key2) \
+	SearchSysCache(cacheId, key1, key2, 0, 0)
+#define SearchSysCache3(cacheId, key1, key2, key3) \
+	SearchSysCache(cacheId, key1, key2, key3, 0)
+#define SearchSysCache4(cacheId, key1, key2, key3, key4) \
+	SearchSysCache(cacheId, key1, key2, key3, key4)
+
+#define SearchSysCacheCopy1(cacheId, key1) \
+	SearchSysCacheCopy(cacheId, key1, 0, 0, 0)
+#define SearchSysCacheCopy2(cacheId, key1, key2) \
+	SearchSysCacheCopy(cacheId, key1, key2, 0, 0)
+#define SearchSysCacheCopy3(cacheId, key1, key2, key3) \
+	SearchSysCacheCopy(cacheId, key1, key2, key3, 0)
+#define SearchSysCacheCopy4(cacheId, key1, key2, key3, key4) \
+	SearchSysCacheCopy(cacheId, key1, key2, key3, key4)
+
+#define SearchSysCacheExists1(cacheId, key1) \
+	SearchSysCacheExists(cacheId, key1, 0, 0, 0)
+#define SearchSysCacheExists2(cacheId, key1, key2) \
+	SearchSysCacheExists(cacheId, key1, key2, 0, 0)
+#define SearchSysCacheExists3(cacheId, key1, key2, key3) \
+	SearchSysCacheExists(cacheId, key1, key2, key3, 0)
+#define SearchSysCacheExists4(cacheId, key1, key2, key3, key4) \
+	SearchSysCacheExists(cacheId, key1, key2, key3, key4)
+
+#define GetSysCacheOid1(cacheId, key1) \
+	GetSysCacheOid(cacheId, key1, 0, 0, 0)
+#define GetSysCacheOid2(cacheId, key1, key2) \
+	GetSysCacheOid(cacheId, key1, key2, 0, 0)
+#define GetSysCacheOid3(cacheId, key1, key2, key3) \
+	GetSysCacheOid(cacheId, key1, key2, key3, 0)
+#define GetSysCacheOid4(cacheId, key1, key2, key3, key4) \
+	GetSysCacheOid(cacheId, key1, key2, key3, key4)
+
+#define SearchSysCacheList1(cacheId, key1) \
+	SearchSysCacheList(cacheId, 1, key1, 0, 0, 0)
+#define SearchSysCacheList2(cacheId, key1, key2) \
+	SearchSysCacheList(cacheId, 2, key1, key2, 0, 0)
+#define SearchSysCacheList3(cacheId, key1, key2, key3) \
+	SearchSysCacheList(cacheId, 3, key1, key2, key3, 0)
+#define SearchSysCacheList4(cacheId, key1, key2, key3, key4) \
+	SearchSysCacheList(cacheId, 4, key1, key2, key3, key4)
+
 #define ReleaseSysCacheList(x)	ReleaseCatCacheList(x)
 
 #endif   /* SYSCACHE_H */