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, 47 insertions, 48 deletions

diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index 2877999500c..bbbb5aa2cfc 100644
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.123 2000/11/12 00:36:56 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.124 2000/11/16 22:30:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -48,9 +48,9 @@
 static void CopyTo(Relation rel, bool binary, bool oids, FILE *fp, char *delim, char *null_print);
 static void CopyFrom(Relation rel, bool binary, bool oids, FILE *fp, char *delim, char *null_print);
 static Oid	GetOutputFunction(Oid type);
-static Oid	GetTypeElement(Oid type);
 static Oid	GetInputFunction(Oid type);
-static Oid	IsTypeByVal(Oid type);
+static Oid	GetTypeElement(Oid type);
+static bool IsTypeByVal(Oid type);
 static void CopyReadNewline(FILE *fp, int *newline);
 static char *CopyReadAttribute(FILE *fp, bool *isnull, char *delim, int *newline, char *null_print);
 
@@ -669,7 +669,7 @@ CopyFrom(Relation rel, bool binary, bool oids, FILE *fp,
 			continue;
 		}
 #endif	 /* _DROP_COLUMN_HACK__ */
-		byval[i] = (bool) IsTypeByVal(attr[i]->atttypid);
+		byval[i] = IsTypeByVal(attr[i]->atttypid);
 	}
 
 	lineno = 0;
@@ -893,65 +893,64 @@ static Oid
 GetOutputFunction(Oid type)
 {
 	HeapTuple	typeTuple;
-
-	typeTuple = SearchSysCacheTuple(TYPEOID,
-									ObjectIdGetDatum(type),
-									0, 0, 0);
-
-	if (HeapTupleIsValid(typeTuple))
-		return (int) ((Form_pg_type) GETSTRUCT(typeTuple))->typoutput;
-
-	elog(ERROR, "GetOutputFunction: Cache lookup of type %u failed", type);
-	return InvalidOid;
+	Oid			result;
+
+	typeTuple = SearchSysCache(TYPEOID,
+							   ObjectIdGetDatum(type),
+							   0, 0, 0);
+	if (!HeapTupleIsValid(typeTuple))
+		elog(ERROR, "GetOutputFunction: Cache lookup of type %u failed", type);
+	result = ((Form_pg_type) GETSTRUCT(typeTuple))->typoutput;
+	ReleaseSysCache(typeTuple);
+	return result;
 }
 
 static Oid
-GetTypeElement(Oid type)
+GetInputFunction(Oid type)
 {
 	HeapTuple	typeTuple;
-
-	typeTuple = SearchSysCacheTuple(TYPEOID,
-									ObjectIdGetDatum(type),
-									0, 0, 0);
-
-	if (HeapTupleIsValid(typeTuple))
-		return (int) ((Form_pg_type) GETSTRUCT(typeTuple))->typelem;
-
-	elog(ERROR, "GetOutputFunction: Cache lookup of type %u failed", type);
-	return InvalidOid;
+	Oid			result;
+
+	typeTuple = SearchSysCache(TYPEOID,
+							   ObjectIdGetDatum(type),
+							   0, 0, 0);
+	if (!HeapTupleIsValid(typeTuple))
+		elog(ERROR, "GetInputFunction: Cache lookup of type %u failed", type);
+	result = ((Form_pg_type) GETSTRUCT(typeTuple))->typinput;
+	ReleaseSysCache(typeTuple);
+	return result;
 }
 
 static Oid
-GetInputFunction(Oid type)
+GetTypeElement(Oid type)
 {
 	HeapTuple	typeTuple;
-
-	typeTuple = SearchSysCacheTuple(TYPEOID,
-									ObjectIdGetDatum(type),
-									0, 0, 0);
-
-	if (HeapTupleIsValid(typeTuple))
-		return (int) ((Form_pg_type) GETSTRUCT(typeTuple))->typinput;
-
-	elog(ERROR, "GetInputFunction: Cache lookup of type %u failed", type);
-	return InvalidOid;
+	Oid			result;
+
+	typeTuple = SearchSysCache(TYPEOID,
+							   ObjectIdGetDatum(type),
+							   0, 0, 0);
+	if (!HeapTupleIsValid(typeTuple))
+		elog(ERROR, "GetTypeElement: Cache lookup of type %u failed", type);
+	result = ((Form_pg_type) GETSTRUCT(typeTuple))->typelem;
+	ReleaseSysCache(typeTuple);
+	return result;
 }
 
-static Oid
+static bool
 IsTypeByVal(Oid type)
 {
 	HeapTuple	typeTuple;
-
-	typeTuple = SearchSysCacheTuple(TYPEOID,
-									ObjectIdGetDatum(type),
-									0, 0, 0);
-
-	if (HeapTupleIsValid(typeTuple))
-		return (int) ((Form_pg_type) GETSTRUCT(typeTuple))->typbyval;
-
-	elog(ERROR, "GetInputFunction: Cache lookup of type %u failed", type);
-
-	return InvalidOid;
+	bool		result;
+
+	typeTuple = SearchSysCache(TYPEOID,
+							   ObjectIdGetDatum(type),
+							   0, 0, 0);
+	if (!HeapTupleIsValid(typeTuple))
+		elog(ERROR, "IsTypeByVal: Cache lookup of type %u failed", type);
+	result = ((Form_pg_type) GETSTRUCT(typeTuple))->typbyval;
+	ReleaseSysCache(typeTuple);
+	return result;
 }