Merge "Get rid of the Resource.resource_class() method"

heat/engine/resource.py

@@ -391,19 +391,6 @@ class Resource(object):
         # common resources have not nested, StackResource overrides it
         return False
 
-    def resource_class(self):
-        """Return the resource class.
-
-        This is used to compare old and new resources when updating, to ensure
-        that in-place updates are possible. This method shold return the
-        highest common class in the hierarchy whose subclasses are all capable
-        of converting to each other's types via handle_update().
-
-        This mechanism may disappear again in future, so third-party resource
-        types should not rely on it.
-        """
-        return type(self)
-
     def has_hook(self, hook):
         # Clear the cache to make sure the data is up to date:
         self._data = None

heat/engine/resources/template_resource.py

@@ -65,11 +65,6 @@ class TemplateResource(stack_resource.StackResource):
         if self.validation_exception is None:
             self._generate_schema(self.t)
 
-    def resource_class(self):
-        # All TemplateResource subclasses can be converted to each other with
-        # a stack update, so allow them to cross-update in place.
-        return TemplateResource
-
     def _get_resource_info(self, rsrc_defn):
         try:
             tri = self.stack.env.get_resource_info(

heat/engine/update.py

@@ -135,10 +135,9 @@ class StackUpdate(object):
     @scheduler.wrappertask
     def _process_new_resource_update(self, new_res):
         res_name = new_res.name
-        res_class = new_res.resource_class()
 
         if (res_name in self.existing_stack and
-                self.existing_stack[res_name].resource_class() is res_class):
+                type(self.existing_stack[res_name]) is type(new_res)):
             existing_res = self.existing_stack[res_name]
             try:
                 yield self._update_in_place(existing_res,