Change many routines to return ObjectAddress rather than OID

The changed routines are mostly those that can be directly called by
ProcessUtilitySlow; the intention is to make the affected object
information more precise, in support for future event trigger changes.
Originally it was envisioned that the OID of the affected object would
be enough, and in most cases that is correct, but upon actually
implementing the event trigger changes it turned out that ObjectAddress
is more widely useful.

Additionally, some command execution routines grew an output argument
that's an object address which provides further info about the executed
command.  To wit:

* for ALTER DOMAIN / ADD CONSTRAINT, it corresponds to the address of
  the new constraint

* for ALTER OBJECT / SET SCHEMA, it corresponds to the address of the
  schema that originally contained the object.

* for ALTER EXTENSION {ADD, DROP} OBJECT, it corresponds to the address
  of the object added to or dropped from the extension.

There's no user-visible change in this commit, and no functional change
either.

Discussion: 20150218213255.GC6717@tamriel.snowman.net
Reviewed-By: Stephen Frost, Andres Freund

1 files changed, 43 insertions, 21 deletions

diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c
index 3b95552a60f..aa733575e46 100644
--- a/src/backend/commands/extension.c
+++ b/src/backend/commands/extension.c
@@ -1170,7 +1170,7 @@ find_update_path(List *evi_list,
 /*
  * CREATE EXTENSION
  */
-Oid
+ObjectAddress
 CreateExtension(CreateExtensionStmt *stmt)
 {
 	DefElem    *d_schema = NULL;
@@ -1188,6 +1188,7 @@ CreateExtension(CreateExtensionStmt *stmt)
 	List	   *requiredSchemas;
 	Oid			extensionOid;
 	ListCell   *lc;
+	ObjectAddress address;
 
 	/* Check extension name validity before any filesystem access */
 	check_valid_extension_name(stmt->extname);
@@ -1206,7 +1207,7 @@ CreateExtension(CreateExtensionStmt *stmt)
 					(errcode(ERRCODE_DUPLICATE_OBJECT),
 					 errmsg("extension \"%s\" already exists, skipping",
 							stmt->extname)));
-			return InvalidOid;
+			return InvalidObjectAddress;
 		}
 		else
 			ereport(ERROR,
@@ -1443,12 +1444,13 @@ CreateExtension(CreateExtensionStmt *stmt)
 	/*
 	 * Insert new tuple into pg_extension, and create dependency entries.
 	 */
-	extensionOid = InsertExtensionTuple(control->name, extowner,
-										schemaOid, control->relocatable,
-										versionName,
-										PointerGetDatum(NULL),
-										PointerGetDatum(NULL),
-										requiredExtensions);
+	address = InsertExtensionTuple(control->name, extowner,
+								   schemaOid, control->relocatable,
+								   versionName,
+								   PointerGetDatum(NULL),
+								   PointerGetDatum(NULL),
+								   requiredExtensions);
+	extensionOid = address.objectId;
 
 	/*
 	 * Apply any control-file comment on extension
@@ -1471,7 +1473,7 @@ CreateExtension(CreateExtensionStmt *stmt)
 	ApplyExtensionUpdates(extensionOid, pcontrol,
 						  versionName, updateVersions);
 
-	return extensionOid;
+	return address;
 }
 
 /*
@@ -1487,7 +1489,7 @@ CreateExtension(CreateExtensionStmt *stmt)
  * extConfig and extCondition should be arrays or PointerGetDatum(NULL).
  * We declare them as plain Datum to avoid needing array.h in extension.h.
  */
-Oid
+ObjectAddress
 InsertExtensionTuple(const char *extName, Oid extOwner,
 					 Oid schemaOid, bool relocatable, const char *extVersion,
 					 Datum extConfig, Datum extCondition,
@@ -1564,7 +1566,7 @@ InsertExtensionTuple(const char *extName, Oid extOwner,
 	/* Post creation hook for new extension */
 	InvokeObjectPostCreateHook(ExtensionRelationId, extensionOid, 0);
 
-	return extensionOid;
+	return myself;
 }
 
 /*
@@ -2399,8 +2401,8 @@ extension_config_remove(Oid extensionoid, Oid tableoid)
 /*
  * Execute ALTER EXTENSION SET SCHEMA
  */
-Oid
-AlterExtensionNamespace(List *names, const char *newschema)
+ObjectAddress
+AlterExtensionNamespace(List *names, const char *newschema, Oid *oldschema)
 {
 	char	   *extensionName;
 	Oid			extensionOid;
@@ -2416,6 +2418,7 @@ AlterExtensionNamespace(List *names, const char *newschema)
 	SysScanDesc depScan;
 	HeapTuple	depTup;
 	ObjectAddresses *objsMoved;
+	ObjectAddress extAddr;
 
 	if (list_length(names) != 1)
 		ereport(ERROR,
@@ -2480,7 +2483,7 @@ AlterExtensionNamespace(List *names, const char *newschema)
 	if (extForm->extnamespace == nspOid)
 	{
 		heap_close(extRel, RowExclusiveLock);
-		return InvalidOid;
+		return InvalidObjectAddress;
 	}
 
 	/* Check extension is supposed to be relocatable */
@@ -2557,6 +2560,10 @@ AlterExtensionNamespace(List *names, const char *newschema)
 							   get_namespace_name(oldNspOid))));
 	}
 
+	/* report old schema, if caller wants it */
+	if (oldschema)
+		*oldschema = oldNspOid;
+
 	systable_endscan(depScan);
 
 	relation_close(depRel, AccessShareLock);
@@ -2575,13 +2582,15 @@ AlterExtensionNamespace(List *names, const char *newschema)
 
 	InvokeObjectPostAlterHook(ExtensionRelationId, extensionOid, 0);
 
-	return extensionOid;
+	ObjectAddressSet(extAddr, ExtensionRelationId, extensionOid);
+
+	return extAddr;
 }
 
 /*
  * Execute ALTER EXTENSION UPDATE
  */
-Oid
+ObjectAddress
 ExecAlterExtensionStmt(AlterExtensionStmt *stmt)
 {
 	DefElem    *d_new_version = NULL;
@@ -2597,6 +2606,7 @@ ExecAlterExtensionStmt(AlterExtensionStmt *stmt)
 	Datum		datum;
 	bool		isnull;
 	ListCell   *lc;
+	ObjectAddress address;
 
 	/*
 	 * We use global variables to track the extension being created, so we can
@@ -2698,7 +2708,7 @@ ExecAlterExtensionStmt(AlterExtensionStmt *stmt)
 		ereport(NOTICE,
 		   (errmsg("version \"%s\" of extension \"%s\" is already installed",
 				   versionName, stmt->extname)));
-		return InvalidOid;
+		return InvalidObjectAddress;
 	}
 
 	/*
@@ -2715,7 +2725,9 @@ ExecAlterExtensionStmt(AlterExtensionStmt *stmt)
 	ApplyExtensionUpdates(extensionOid, control,
 						  oldVersionName, updateVersions);
 
-	return extensionOid;
+	ObjectAddressSet(address, ExtensionRelationId, extensionOid);
+
+	return address;
 }
 
 /*
@@ -2879,9 +2891,15 @@ ApplyExtensionUpdates(Oid extensionOid,
 
 /*
  * Execute ALTER EXTENSION ADD/DROP
+ *
+ * Return value is the address of the altered extension.
+ *
+ * objAddr is an output argument which, if not NULL, is set to the address of
+ * the added/dropped object.
  */
-Oid
-ExecAlterExtensionContentsStmt(AlterExtensionContentsStmt *stmt)
+ObjectAddress
+ExecAlterExtensionContentsStmt(AlterExtensionContentsStmt *stmt,
+							   ObjectAddress *objAddr)
 {
 	ObjectAddress extension;
 	ObjectAddress object;
@@ -2906,6 +2924,10 @@ ExecAlterExtensionContentsStmt(AlterExtensionContentsStmt *stmt)
 	object = get_object_address(stmt->objtype, stmt->objname, stmt->objargs,
 								&relation, ShareUpdateExclusiveLock, false);
 
+	Assert(object.objectSubId == 0);
+	if (objAddr)
+		*objAddr = object;
+
 	/* Permission check: must own target object, too */
 	check_object_ownership(GetUserId(), stmt->objtype, object,
 						   stmt->objname, stmt->objargs, relation);
@@ -2984,5 +3006,5 @@ ExecAlterExtensionContentsStmt(AlterExtensionContentsStmt *stmt)
 	if (relation != NULL)
 		relation_close(relation, NoLock);
 
-	return extension.objectId;
+	return extension;
 }