Change SearchSysCache coding conventions so that a reference count is

maintained for each cache entry.  A cache entry will not be freed until
the matching ReleaseSysCache call has been executed.  This eliminates
worries about cache entries getting dropped while still in use.  See
my posting to pg-hackers of even date for more info.

1 files changed, 32 insertions, 33 deletions

diff --git a/src/backend/catalog/pg_proc.c b/src/backend/catalog/pg_proc.c
index 26861047b24..9d3ce5c50d6 100644
--- a/src/backend/catalog/pg_proc.c
+++ b/src/backend/catalog/pg_proc.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/catalog/pg_proc.c,v 1.49 2000/10/07 00:58:15 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/catalog/pg_proc.c,v 1.50 2000/11/16 22:30:17 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -71,7 +71,7 @@ ProcedureCreate(char *procedureName,
 	Oid			toid;
 	NameData	procname;
 	TupleDesc	tupDesc;
-	Oid		retval;
+	Oid			retval;
 
 	/* ----------------
 	 *	sanity checks
@@ -80,15 +80,12 @@ ProcedureCreate(char *procedureName,
 	Assert(PointerIsValid(prosrc));
 	Assert(PointerIsValid(probin));
 
-	tup = SearchSysCacheTuple(LANGNAME,
-							  PointerGetDatum(languageName),
-							  0, 0, 0);
-
-	if (!HeapTupleIsValid(tup))
+	languageObjectId = GetSysCacheOid(LANGNAME,
+									  PointerGetDatum(languageName),
+									  0, 0, 0);
+	if (!OidIsValid(languageObjectId))
 		elog(ERROR, "ProcedureCreate: no such language '%s'", languageName);
 
-	languageObjectId = tup->t_data->t_oid;
-
 	parameterCount = 0;
 	MemSet(typev, 0, FUNC_MAX_ARGS * sizeof(Oid));
 	foreach(x, argList)
@@ -124,13 +121,12 @@ ProcedureCreate(char *procedureName,
 		typev[parameterCount++] = toid;
 	}
 
-	tup = SearchSysCacheTuple(PROCNAME,
-							  PointerGetDatum(procedureName),
-							  UInt16GetDatum(parameterCount),
-							  PointerGetDatum(typev),
-							  0);
-
-	if (HeapTupleIsValid(tup))
+	/* Check for duplicate definition */
+	if (SearchSysCacheExists(PROCNAME,
+							 PointerGetDatum(procedureName),
+							 UInt16GetDatum(parameterCount),
+							 PointerGetDatum(typev),
+							 0))
 		elog(ERROR, "ProcedureCreate: procedure %s already exists with same arguments",
 			 procedureName);
 
@@ -161,12 +157,12 @@ ProcedureCreate(char *procedureName,
 
 			prosrctext = DatumGetTextP(DirectFunctionCall1(textin,
 													CStringGetDatum(prosrc)));
-			tup = SearchSysCacheTuple(PROSRC,
-									  PointerGetDatum(prosrctext),
-									  0, 0, 0);
+			retval = GetSysCacheOid(PROSRC,
+									PointerGetDatum(prosrctext),
+									0, 0, 0);
 			pfree(prosrctext);
-			if (HeapTupleIsValid(tup))
-				return tup->t_data->t_oid;
+			if (OidIsValid(retval))
+				return retval;
 #else
 			elog(ERROR, "lookup for procedure by source needs fix (Jan)");
 #endif	 /* SETS_FIXED */
@@ -351,7 +347,7 @@ checkretval(Oid rettype, List *queryTreeList)
 	List	   *tlist;
 	List	   *tlistitem;
 	int			tlistlen;
-	Type		typ;
+	Oid			typerelid;
 	Resdom	   *resnode;
 	Relation	reln;
 	Oid			relid;
@@ -375,11 +371,9 @@ checkretval(Oid rettype, List *queryTreeList)
 	}
 
 	/* by here, the function is declared to return some type */
-	if ((typ = typeidType(rettype)) == NULL)
-		elog(ERROR, "can't find return type %u for function", rettype);
-
 	if (cmd != CMD_SELECT)
-		elog(ERROR, "function declared to return %s, but final query is not a SELECT", typeTypeName(typ));
+		elog(ERROR, "function declared to return %s, but final query is not a SELECT",
+			 typeidTypeName(rettype));
 
 	/*
 	 * Count the non-junk entries in the result targetlist.
@@ -390,14 +384,17 @@ checkretval(Oid rettype, List *queryTreeList)
 	 * For base-type returns, the target list should have exactly one entry,
 	 * and its type should agree with what the user declared.
 	 */
-	if (typeTypeRelid(typ) == InvalidOid)
+	typerelid = typeidTypeRelid(rettype);
+	if (typerelid == InvalidOid)
 	{
 		if (tlistlen != 1)
-			elog(ERROR, "function declared to return %s returns multiple columns in final SELECT", typeTypeName(typ));
+			elog(ERROR, "function declared to return %s returns multiple columns in final SELECT",
+				 typeidTypeName(rettype));
 
 		resnode = (Resdom *) ((TargetEntry *) lfirst(tlist))->resdom;
 		if (resnode->restype != rettype)
-			elog(ERROR, "return type mismatch in function: declared to return %s, returns %s", typeTypeName(typ), typeidTypeName(resnode->restype));
+			elog(ERROR, "return type mismatch in function: declared to return %s, returns %s",
+				 typeidTypeName(rettype), typeidTypeName(resnode->restype));
 
 		return;
 	}
@@ -422,12 +419,13 @@ checkretval(Oid rettype, List *queryTreeList)
 	 * declared return type, and be sure that attributes 1 .. n in the target
 	 * list match the declared types.
 	 */
-	reln = heap_open(typeTypeRelid(typ), AccessShareLock);
+	reln = heap_open(typerelid, AccessShareLock);
 	relid = reln->rd_id;
 	relnatts = reln->rd_rel->relnatts;
 
 	if (tlistlen != relnatts)
-		elog(ERROR, "function declared to return %s does not SELECT the right number of columns (%d)", typeTypeName(typ), relnatts);
+		elog(ERROR, "function declared to return %s does not SELECT the right number of columns (%d)",
+			 typeidTypeName(rettype), relnatts);
 
 	/* expect attributes 1 .. n in order */
 	i = 0;
@@ -441,7 +439,7 @@ checkretval(Oid rettype, List *queryTreeList)
 		tletype = exprType(tle->expr);
 		if (tletype != reln->rd_att->attrs[i]->atttypid)
 			elog(ERROR, "function declared to return %s returns %s instead of %s at column %d",
-				 typeTypeName(typ),
+				 typeidTypeName(rettype),
 				 typeidTypeName(tletype),
 				 typeidTypeName(reln->rd_att->attrs[i]->atttypid),
 				 i+1);
@@ -450,7 +448,8 @@ checkretval(Oid rettype, List *queryTreeList)
 
 	/* this shouldn't happen, but let's just check... */
 	if (i != relnatts)
-		elog(ERROR, "function declared to return %s does not SELECT the right number of columns (%d)", typeTypeName(typ), relnatts);
+		elog(ERROR, "function declared to return %s does not SELECT the right number of columns (%d)",
+			 typeidTypeName(rettype), relnatts);
 
 	heap_close(reln, AccessShareLock);
 }