From cd3931c635777fd6ca256192644d3c3e0cdc8483 Mon Sep 17 00:00:00 2001
From: Anant Patil <anant.patil@hp.com>
Date: Mon, 20 Jul 2015 11:09:18 +0530
Subject: [PATCH] Convergence: Refactor convergence dependency

A new property is added to fetch convergence dependencies from the
stack.

Change-Id: If2eb29f9222f21390513fad5702dc4718d5c4165
---
 heat/engine/stack.py  | 32 +++++++++++++++++++++-----------
 heat/engine/worker.py | 10 ++--------
 2 files changed, 23 insertions(+), 19 deletions(-)

diff --git a/heat/engine/stack.py b/heat/engine/stack.py
index 77d77f0f85..98156b582e 100755
--- a/heat/engine/stack.py
+++ b/heat/engine/stack.py
@@ -144,6 +144,7 @@ class Stack(collections.Mapping):
         self.current_deps = current_deps
         self.cache_data = cache_data
         self._worker_client = None
+        self._convg_deps = None
 
         if use_stored_context:
             self.context = self.stored_context()
@@ -971,8 +972,13 @@ class Stack(collections.Mapping):
 
     def _converge_create_or_update(self):
         self._update_or_store_resources()
-        self.convergence_dependencies = self._convergence_dependencies(
-            self.ext_rsrcs_db, self.dependencies)
+        self._compute_convg_dependencies(self.ext_rsrcs_db, self.dependencies)
+        # Store list of edges
+        self.current_deps = {
+            'edges': [[rqr, rqd] for rqr, rqd in
+                      self.convergence_dependencies.graph().edges()]}
+        self.store()
+
         LOG.info(_LI('convergence_dependencies: %s'),
                  self.convergence_dependencies)
 
@@ -985,12 +991,6 @@ class Stack(collections.Mapping):
         sync_point.create(
             self.context, self.id, self.current_traversal, True, self.id)
 
-        # Store list of edges
-        self.current_deps = {
-            'edges': [[rqr, rqd] for rqr, rqd in
-                      self.convergence_dependencies.graph().edges()]}
-        self.store()
-
         leaves = set(self.convergence_dependencies.leaves())
         if not any(leaves):
             self.mark_complete(self.current_traversal)
@@ -1070,8 +1070,8 @@ class Stack(collections.Mapping):
                 )
                 rsrcs[existing_rsrc_db.name] = existing_rsrc_db
 
-    def _convergence_dependencies(self, existing_resources,
-                                  curr_template_dep):
+    def _compute_convg_dependencies(self, existing_resources,
+                                    curr_template_dep):
         dep = curr_template_dep.translate(lambda res: (res.id, True))
         if existing_resources:
             for rsrc_id, rsrc in existing_resources.items():
@@ -1085,7 +1085,17 @@ class Stack(collections.Mapping):
 
                 if (rsrc.id, True) in dep:
                     dep += (rsrc_id, False), (rsrc_id, True)
-        return dep
+
+        self._convg_deps = dep
+
+    @property
+    def convergence_dependencies(self):
+        if self._convg_deps is None:
+            current_deps = ([tuple(i), (tuple(j) if j is not None else None)]
+                            for i, j in self.current_deps['edges'])
+            self._convg_deps = dependencies.Dependencies(edges=current_deps)
+
+        return self._convg_deps
 
     @scheduler.wrappertask
     def update_task(self, newstack, action=UPDATE, event=None):
diff --git a/heat/engine/worker.py b/heat/engine/worker.py
index 0a5408495b..c4eefa7202 100644
--- a/heat/engine/worker.py
+++ b/heat/engine/worker.py
@@ -24,7 +24,6 @@ from heat.common import exception
 from heat.common.i18n import _LE
 from heat.common.i18n import _LI
 from heat.common import messaging as rpc_messaging
-from heat.engine import dependencies
 from heat.engine import resource
 from heat.engine import stack as parser
 from heat.engine import sync_point
@@ -180,14 +179,9 @@ class WorkerService(service.Service):
 
         return False
 
-    def _compute_dependencies(self, stack):
-        current_deps = ([tuple(i), (tuple(j) if j is not None else None)]
-                        for i, j in stack.current_deps['edges'])
-        return dependencies.Dependencies(edges=current_deps)
-
     def _retrigger_check_resource(self, cnxt, is_update, resource_id, stack):
         current_traversal = stack.current_traversal
-        graph = self._compute_dependencies(stack).graph()
+        graph = stack.convergence_dependencies.graph()
         key = (resource_id, is_update)
         predecessors = graph[key]
 
@@ -204,7 +198,7 @@ class WorkerService(service.Service):
     def _initiate_propagate_resource(self, cnxt, resource_id,
                                      current_traversal, is_update, rsrc,
                                      stack):
-        deps = self._compute_dependencies(stack)
+        deps = stack.convergence_dependencies
         graph = deps.graph()
         graph_key = (resource_id, is_update)