Get rid of Resource.needed_by (formerly Resource.requirers)

Apparently this is not used by anything. It appears to have been made
effectively obsolete by ee48d93, and
the last actual reference to it was removed in
786f367.

converge/converger.py

@@ -37,10 +37,6 @@ def check_resource_cleanup(self, rsrc, template_key, data):
         '''
         Delete the Resource if appropriate.
         '''
-        # Clear out deleted resources from the needed_by list
-        rsrc.clear_needed_by(rsrc_key for rsrc_key, key in data.items()
-                                      if key is None)
-
         if rsrc.template_key != template_key:
             rsrc.delete()
 

converge/resource.py

@@ -12,7 +12,7 @@
 
 resources = datastore.Datastore('Resource',
                                 'key', 'stack_key', 'name', 'template_key',
-                                'needed_by', 'requires',
+                                'requires',
                                 'replaces', 'replaced_by',
                                 'props_data', 'phys_id',
                                 'status')
@@ -37,7 +37,7 @@ class Resource(object):
     simulation.
     '''
     def __init__(self, name, stack, defn, template_key=None,
-                 needed_by=set(), requires=set(),
+                 requires=set(),
                  replaces=None, replaced_by=None,
                  props_data=None, phys_id=None,
                  status=COMPLETE,
@@ -47,7 +47,6 @@ def __init__(self, name, stack, defn, template_key=None,
         self.stack = stack
         self.defn = defn
         self.template_key = template_key
-        self.needed_by = needed_by
         self.requires = requires
         self.replaces = replaces
         self.replaced_by = replaced_by
@@ -61,7 +60,6 @@ def _load_from_store(cls, key, get_stack):
         return cls(loaded.name, get_stack(loaded.stack_key),
                    None,
                    loaded.template_key,
-                   loaded.needed_by,
                    loaded.requires,
                    loaded.replaces,
                    loaded.replaced_by,
@@ -86,7 +84,6 @@ def store(self):
             'name': self.name,
             'stack_key': self.stack.key,
             'template_key': self.template_key,
-            'needed_by': self.needed_by,
             'requires': self.requires,
             'replaces': self.replaces,
             'replaced_by': self.replaced_by,
@@ -160,18 +157,14 @@ def update(self, template_key, resource_data):
     def make_replacement(self, template_key, resource_data):
         rsrc = Resource(self.name, self.stack,
                         self.defn, template_key,
-                        needed_by=self.needed_by, replaces=self.key)
+                        replaces=self.key)
         rsrc.store()
 
         self.replaced_by = rsrc.key
         self.store()
 
         return rsrc
 
-    def clear_needed_by(self, gone_requirers):
-        self.needed_by -= set(gone_requirers)
-        self.store()
-
     def delete(self):
         if self.status == IN_PROGRESS:
             logger.info('[%s(%d)] Previous update still in progress')

converge/stack.py

@@ -199,10 +199,6 @@ def get_resource(rsrc_name):
             if rsrc is None:
                 rsrc = resource.Resource(rsrc_name, self,
                                          definitions[rsrc_name], self.tmpl.key)
-
-            nb = set(rsrcs[r].key for r in tmpl_deps.required_by(rsrc_name))
-            rsrc.needed_by = rsrc.needed_by | nb
-
             return rsrc
 
         # Resources that will form the update part of the graph