Standardize get_whatever_oid functions for other object types.

- Rename TSParserGetPrsid to get_ts_parser_oid.
- Rename TSDictionaryGetDictid to get_ts_dict_oid.
- Rename TSTemplateGetTmplid to get_ts_template_oid.
- Rename TSConfigGetCfgid to get_ts_config_oid.
- Rename FindConversionByName to get_conversion_oid.
- Rename GetConstraintName to get_constraint_oid.
- Add new functions get_opclass_oid, get_opfamily_oid, get_rewrite_oid,
  get_rewrite_oid_without_relid, get_trigger_oid, and get_cast_oid.

The name of each function matches the corresponding catalog.

Thanks to KaiGai Kohei for the review.

1 files changed, 85 insertions, 1 deletions

diff --git a/src/backend/rewrite/rewriteSupport.c b/src/backend/rewrite/rewriteSupport.c
index 8f668f5791e..0e39b060735 100644
--- a/src/backend/rewrite/rewriteSupport.c
+++ b/src/backend/rewrite/rewriteSupport.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/rewrite/rewriteSupport.c,v 1.69 2010/02/14 18:42:15 rhaas Exp $
+ *	  $PostgreSQL: pgsql/src/backend/rewrite/rewriteSupport.c,v 1.70 2010/08/05 15:25:35 rhaas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -17,9 +17,14 @@
 #include "access/heapam.h"
 #include "catalog/indexing.h"
 #include "catalog/pg_class.h"
+#include "catalog/pg_rewrite.h"
 #include "rewrite/rewriteSupport.h"
+#include "utils/fmgroids.h"
 #include "utils/inval.h"
+#include "utils/lsyscache.h"
+#include "utils/rel.h"
 #include "utils/syscache.h"
+#include "utils/tqual.h"
 
 
 /*
@@ -86,3 +91,82 @@ SetRelationRuleStatus(Oid relationId, bool relHasRules,
 	heap_freetuple(tuple);
 	heap_close(relationRelation, RowExclusiveLock);
 }
+
+/*
+ * Find rule oid.
+ *
+ * If missing_ok is false, throw an error if rule name not found.  If
+ * true, just return InvalidOid.
+ */
+Oid
+get_rewrite_oid(Oid relid, const char *rulename, bool missing_ok)
+{
+	HeapTuple	tuple;
+	Oid			ruleoid;
+
+	/* Find the rule's pg_rewrite tuple, get its OID */
+	tuple = SearchSysCache2(RULERELNAME,
+							ObjectIdGetDatum(relid),
+							PointerGetDatum(rulename));
+	if (!HeapTupleIsValid(tuple))
+	{
+		if (missing_ok)
+			return InvalidOid;
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("rule \"%s\" for relation \"%s\" does not exist",
+						rulename, get_rel_name(relid))));
+	}
+	Assert(relid == ((Form_pg_rewrite) GETSTRUCT(tuple))->ev_class);
+	ruleoid = HeapTupleGetOid(tuple);
+	ReleaseSysCache(tuple);
+	return ruleoid;
+}
+
+/*
+ * Find rule oid, given only a rule name but no rel OID.
+ *
+ * If there's more than one, it's an error.  If there aren't any, that's an
+ * error, too.  In general, this should be avoided - it is provided to support
+ * syntax that is compatible with pre-7.3 versions of PG, where rule names
+ * were unique across the entire database.
+ */
+Oid
+get_rewrite_oid_without_relid(const char *rulename, Oid *reloid)
+{
+	Relation	RewriteRelation;
+	HeapScanDesc scanDesc;
+	ScanKeyData scanKeyData;
+	HeapTuple	htup;
+	Oid			ruleoid;
+
+	/* Search pg_rewrite for such a rule */
+	ScanKeyInit(&scanKeyData,
+				Anum_pg_rewrite_rulename,
+				BTEqualStrategyNumber, F_NAMEEQ,
+				CStringGetDatum(rulename));
+
+	RewriteRelation = heap_open(RewriteRelationId, AccessShareLock);
+	scanDesc = heap_beginscan(RewriteRelation, SnapshotNow, 1, &scanKeyData);
+
+	htup = heap_getnext(scanDesc, ForwardScanDirection);
+	if (!HeapTupleIsValid(htup))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("rule \"%s\" does not exist", rulename)));
+
+	ruleoid = HeapTupleGetOid(htup);
+	if (reloid != NULL)
+		*reloid = ((Form_pg_rewrite) GETSTRUCT(htup))->ev_class;
+
+	if (HeapTupleIsValid(htup = heap_getnext(scanDesc, ForwardScanDirection)))
+		ereport(ERROR,
+				(errcode(ERRCODE_DUPLICATE_OBJECT),
+				 errmsg("there are multiple rules named \"%s\"", rulename),
+				 errhint("Specify a relation name as well as a rule name.")));
+
+	heap_endscan(scanDesc);
+	heap_close(RewriteRelation, AccessShareLock);
+
+	return ruleoid;
+}