qom: Change object property iterator API contract

Currently the ObjectProperty iterator API works as follows:

  ObjectPropertyIterator *iter;

  iter = object_property_iter_init(obj);
  while ((prop = object_property_iter_next(iter))) {
     ...
  }
  object_property_iter_free(iter);

This has the benefit that the ObjectPropertyIterator struct
can be opaque, but has the downside that callers need to
explicitly call a free function. It is also not in keeping
with iterator style used elsewhere in QEMU/GLib2.

This patch changes the API to use stack allocation instead:

  ObjectPropertyIterator iter;

  object_property_iter_init(&iter, obj);
  while ((prop = object_property_iter_next(&iter))) {
     ...
  }

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[AF: Fused ObjectPropertyIterator struct with typedef]
Signed-off-by: Andreas Färber <afaerber@suse.de>

1 files changed, 4 insertions, 18 deletions

diff --git a/qom/object.c b/qom/object.c
index 5d4c80b..5ff97ab 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -67,11 +67,6 @@ struct TypeImpl
     InterfaceImpl interfaces[MAX_INTERFACES];
 };
 
-struct ObjectPropertyIterator {
-    ObjectClass *nextclass;
-    GHashTableIter iter;
-};
-
 static Type type_interface;
 
 static GHashTable *type_table_get(void)
@@ -999,20 +994,11 @@ ObjectProperty *object_property_find(Object *obj, const char *name,
     return NULL;
 }
 
-ObjectPropertyIterator *object_property_iter_init(Object *obj)
+void object_property_iter_init(ObjectPropertyIterator *iter,
+                               Object *obj)
 {
-    ObjectPropertyIterator *ret = g_new0(ObjectPropertyIterator, 1);
-    g_hash_table_iter_init(&ret->iter, obj->properties);
-    ret->nextclass = object_get_class(obj);
-    return ret;
-}
-
-void object_property_iter_free(ObjectPropertyIterator *iter)
-{
-    if (!iter) {
-        return;
-    }
-    g_free(iter);
+    g_hash_table_iter_init(&iter->iter, obj->properties);
+    iter->nextclass = object_get_class(obj);
 }
 
 ObjectProperty *object_property_iter_next(ObjectPropertyIterator *iter)