qom: add a fast path to object_class_dynamic_cast
For leaf classes, in many cases the callbacks will simply downcast
the object back to the original class. Add this fast path to
object_class_dynamic_cast, object_dynamic_cast will inherit it.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1368188203-3407-4-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/qom/object.c b/qom/object.c
index 35f4694..0aa0c07 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -457,7 +457,12 @@
return NULL;
}
+ /* A simple fast path that can trigger a lot for leaf classes. */
type = class->type;
+ if (type->name == typename) {
+ return class;
+ }
+
target_type = type_get_by_name(typename);
if (!target_type) {
/* target class type unknown, so fail the cast */
