Consolidate DROP handling for some object types.

This gets rid of a significant amount of duplicative code.

KaiGai Kohei, reviewed in earlier versions by Dimitri Fontaine, with
further review and cleanup by me.

Author: robertmhaas

src/backend/catalog/objectaddress.c

@@ -66,22 +66,6 @@
 #include "utils/syscache.h"
 #include "utils/tqual.h"
 
-static ObjectAddress get_object_address_unqualified(ObjectType objtype,
-							   List *qualname, bool missing_ok);
-static ObjectAddress get_relation_by_qualified_name(ObjectType objtype,
-							   List *objname, Relation *relp,
-							   LOCKMODE lockmode, bool missing_ok);
-static ObjectAddress get_object_address_relobject(ObjectType objtype,
-							 List *objname, Relation *relp, bool missing_ok);
-static ObjectAddress get_object_address_attribute(ObjectType objtype,
-							 List *objname, Relation *relp,
-							 LOCKMODE lockmode, bool missing_ok);
-static ObjectAddress get_object_address_type(ObjectType objtype,
-						List *objname, bool missing_ok);
-static ObjectAddress get_object_address_opcf(ObjectType objtype, List *objname,
-						List *objargs, bool missing_ok);
-static bool object_exists(ObjectAddress address);
-
 /*
  * ObjectProperty
  *
@@ -93,137 +77,180 @@ typedef struct
 	Oid			class_oid;			/* oid of catalog */
 	Oid			oid_index_oid; 		/* oid of index on system oid column */
 	int			oid_catcache_id;	/* id of catcache on system oid column  */
+	AttrNumber	attnum_namespace;	/* attnum of namespace field */
 } ObjectPropertyType;
 
 static ObjectPropertyType ObjectProperty[] =
 {
 	{
 		CastRelationId,
 		CastOidIndexId,
-		-1
+		-1,
+		InvalidAttrNumber
 	},
 	{
 		CollationRelationId,
 		CollationOidIndexId,
-		COLLOID
+		COLLOID,
+		Anum_pg_collation_collnamespace
 	},
 	{
 		ConstraintRelationId,
 		ConstraintOidIndexId,
-		CONSTROID
+		CONSTROID,
+		Anum_pg_constraint_connamespace
 	},
 	{
 		ConversionRelationId,
 		ConversionOidIndexId,
-		CONVOID
+		CONVOID,
+		Anum_pg_conversion_connamespace
 	},
 	{
 		DatabaseRelationId,
 		DatabaseOidIndexId,
-		DATABASEOID
+		DATABASEOID,
+		InvalidAttrNumber
 	},
 	{
 		ExtensionRelationId,
 		ExtensionOidIndexId,
-		-1
+		-1,
+		Anum_pg_extension_extnamespace
 	},
 	{
 		ForeignDataWrapperRelationId,
 		ForeignDataWrapperOidIndexId,
-		FOREIGNDATAWRAPPEROID
+		FOREIGNDATAWRAPPEROID,
+		InvalidAttrNumber
 	},
 	{
 		ForeignServerRelationId,
 		ForeignServerOidIndexId,
-		FOREIGNSERVEROID
+		FOREIGNSERVEROID,
+		InvalidAttrNumber
 	},
 	{
 		ProcedureRelationId,
 		ProcedureOidIndexId,
-		PROCOID
+		PROCOID,
+		Anum_pg_proc_pronamespace
 	},
 	{
 		LanguageRelationId,
 		LanguageOidIndexId,
-		LANGOID
+		LANGOID,
+		InvalidAttrNumber,
 	},
 	{
 		LargeObjectMetadataRelationId,
 		LargeObjectMetadataOidIndexId,
-		-1
+		-1,
+		InvalidAttrNumber
 	},
 	{
 		OperatorClassRelationId,
 		OpclassOidIndexId,
-		CLAOID
+		CLAOID,
+		Anum_pg_opclass_opcnamespace,
 	},
 	{
 		OperatorRelationId,
 		OperatorOidIndexId,
-		OPEROID
+		OPEROID,
+		Anum_pg_operator_oprnamespace
 	},
 	{
 		OperatorFamilyRelationId,
 		OpfamilyOidIndexId,
-		OPFAMILYOID
+		OPFAMILYOID,
+		Anum_pg_opfamily_opfnamespace
 	},
 	{
 		AuthIdRelationId,
 		AuthIdOidIndexId,
-		AUTHOID
+		AUTHOID,
+		InvalidAttrNumber
 	},
 	{
 		RewriteRelationId,
 		RewriteOidIndexId,
-		-1
+		-1,
+		InvalidAttrNumber
 	},
 	{
 		NamespaceRelationId,
 		NamespaceOidIndexId,
-		NAMESPACEOID
+		NAMESPACEOID,
+		InvalidAttrNumber
 	},
 	{
 		RelationRelationId,
 		ClassOidIndexId,
-		RELOID
+		RELOID,
+		Anum_pg_class_relnamespace
 	},
 	{
 		TableSpaceRelationId,
 		TablespaceOidIndexId,
 		TABLESPACEOID,
+		InvalidAttrNumber
 	},
 	{
 		TriggerRelationId,
 		TriggerOidIndexId,
-		-1
+		-1,
+		InvalidAttrNumber
 	},
 	{
 		TSConfigRelationId,
 		TSConfigOidIndexId,
-		TSCONFIGOID
+		TSCONFIGOID,
+		Anum_pg_ts_config_cfgnamespace
 	},
 	{
 		TSDictionaryRelationId,
 		TSDictionaryOidIndexId,
-		TSDICTOID
+		TSDICTOID,
+		Anum_pg_ts_dict_dictnamespace
 	},
 	{
 		TSParserRelationId,
 		TSParserOidIndexId,
-		TSPARSEROID
+		TSPARSEROID,
+		Anum_pg_ts_parser_prsnamespace
 	},
 	{
 		TSTemplateRelationId,
 		TSTemplateOidIndexId,
-		TSTEMPLATEOID
+		TSTEMPLATEOID,
+		Anum_pg_ts_template_tmplnamespace,
 	},
 	{
 		TypeRelationId,
 		TypeOidIndexId,
-		TYPEOID
+		TYPEOID,
+		Anum_pg_type_typnamespace
 	}
 };
 
+static ObjectAddress get_object_address_unqualified(ObjectType objtype,
+							   List *qualname, bool missing_ok);
+static ObjectAddress get_relation_by_qualified_name(ObjectType objtype,
+							   List *objname, Relation *relp,
+							   LOCKMODE lockmode, bool missing_ok);
+static ObjectAddress get_object_address_relobject(ObjectType objtype,
+							 List *objname, Relation *relp, bool missing_ok);
+static ObjectAddress get_object_address_attribute(ObjectType objtype,
+							 List *objname, Relation *relp,
+							 LOCKMODE lockmode, bool missing_ok);
+static ObjectAddress get_object_address_type(ObjectType objtype,
+						List *objname, bool missing_ok);
+static ObjectAddress get_object_address_opcf(ObjectType objtype, List *objname,
+						List *objargs, bool missing_ok);
+static bool object_exists(ObjectAddress address);
+static ObjectPropertyType *get_object_property_data(Oid class_id);
+
 /*
  * Translate an object name and arguments (as passed by the parser) to an
  * ObjectAddress.
@@ -828,6 +855,7 @@ object_exists(ObjectAddress address)
 	ScanKeyData skey[1];
 	SysScanDesc sd;
 	bool		found;
+	ObjectPropertyType	   *property;
 
 	/* Sub-objects require special treatment. */
 	if (address.objectSubId != 0)
@@ -847,35 +875,22 @@ object_exists(ObjectAddress address)
 		}
 		return found;
 	}
-	else 
-	{
-		int			index;
 
-		/*
-		 * Weird backward compatibility hack: ObjectAddress notation uses
-		 * LargeObjectRelationId for large objects, but since PostgreSQL
-		 * 9.0, the relevant catalog is actually LargeObjectMetadataRelationId.
-		 */
-		if (address.classId == LargeObjectRelationId)
-			address.classId = LargeObjectMetadataRelationId;
+	/*
+	 * Weird backward compatibility hack: ObjectAddress notation uses
+	 * LargeObjectRelationId for large objects, but since PostgreSQL
+	 * 9.0, the relevant catalog is actually LargeObjectMetadataRelationId.
+	 */
+	if (address.classId == LargeObjectRelationId)
+		address.classId = LargeObjectMetadataRelationId;
 
-		/*
-		 * For object types that have a relevant syscache, we use it; for
-		 * everything else, we'll have to do an index-scan.  Search the
-		 * ObjectProperty array to find out which it is.
-		 */
-		for (index = 0; index < lengthof(ObjectProperty); index++)
-		{
-			if (ObjectProperty[index].class_oid == address.classId)
-			{
-				cache = ObjectProperty[index].oid_catcache_id;
-				indexoid = ObjectProperty[index].oid_index_oid;
-				break;
-			}
-		}
-		if (index == lengthof(ObjectProperty))
-			elog(ERROR, "unrecognized classid: %u", address.classId);
-	}
+	/*
+	 * For object types that have a relevant syscache, we use it; for
+	 * everything else, we'll have to do an index-scan.
+	 */
+	property = get_object_property_data(address.classId);
+	cache = property->oid_catcache_id;
+	indexoid = property->oid_index_oid;
 
 	/* Found a syscache? */
 	if (cache != -1)
@@ -895,7 +910,6 @@ object_exists(ObjectAddress address)
 	return found;
 }
 
-
 /*
  * Check ownership of an object previously identified by get_object_address.
  */
@@ -1060,3 +1074,58 @@ check_object_ownership(Oid roleid, ObjectType objtype, ObjectAddress address,
 				 (int) objtype);
 	}
 }
+
+/*
+ * get_object_namespace
+ *
+ * Find the schema containing the specified object.  For non-schema objects,
+ * this function returns InvalidOid.
+ */
+Oid
+get_object_namespace(const ObjectAddress *address)
+{
+	int			cache;
+	HeapTuple	tuple;
+	bool		isnull;
+	Oid			oid;
+	ObjectPropertyType	   *property;
+
+	/* If not owned by a namespace, just return InvalidOid. */
+	property = get_object_property_data(address->classId);
+	if (property->attnum_namespace == InvalidAttrNumber)
+		return InvalidOid;
+
+	/* Currently, we can only handle object types with system caches. */
+	cache = property->oid_catcache_id;
+	Assert(cache != -1);
+
+	/* Fetch tuple from syscache and extract namespace attribute. */
+	tuple = SearchSysCache1(cache, ObjectIdGetDatum(address->objectId));
+	if (!HeapTupleIsValid(tuple))
+		elog(ERROR, "cache lookup failed for cache %d oid %u",
+			 cache, address->objectId);
+	oid = DatumGetObjectId(SysCacheGetAttr(cache,
+										   tuple,
+										   property->attnum_namespace,
+										   &isnull));
+	Assert(!isnull);
+	ReleaseSysCache(tuple);
+
+	return oid;
+}
+
+/*
+ * Find ObjectProperty structure by class_id.
+ */
+static ObjectPropertyType *
+get_object_property_data(Oid class_id)
+{
+	int			index;
+
+	for (index = 0; index < lengthof(ObjectProperty); index++)
+		if (ObjectProperty[index].class_oid == class_id)
+			return &ObjectProperty[index];
+
+	elog(ERROR, "unrecognized class id: %u", class_id);
+	return NULL;		/* not reached */
+}

src/backend/commands/Makefile

@@ -14,7 +14,7 @@ include $(top_builddir)/src/Makefile.global
 
 OBJS = aggregatecmds.o alter.o analyze.o async.o cluster.o comment.o  \
 	collationcmds.o constraint.o conversioncmds.o copy.o \
-	dbcommands.o define.o discard.o explain.o extension.o \
+	dbcommands.o define.o discard.o dropcmds.o explain.o extension.o \
 	foreigncmds.o functioncmds.o \
 	indexcmds.o lockcmds.o operatorcmds.o opclasscmds.o \
 	portalcmds.o prepare.o proclang.o \