dvc: reuse collected stages

Fixes #710
Fixes #711

Signed-off-by: Ruslan Kuprieiev <[email protected]>

dvc/output.py

@@ -135,13 +135,6 @@ class Dependency(object):
     def loads_from(cls, project, s_list, cwd=os.curdir):
         return [cls.loads(project, x, cwd=cwd) for x in s_list]
 
-    def stage(self):
-        for stage in self.project.stages():
-            for out in stage.outs:
-                if self.path == out.path:
-                    return stage
-        return None
-
 
 class Output(Dependency):
     PARAM_CACHE = 'cache'

dvc/project.py

@@ -239,7 +239,7 @@ class Project(object):
         else:
             stages = self.stages()
 
-        for stage in self.stages():
+        for stage in stages:
             status.update(stage.status())
 
         return status
@@ -326,12 +326,18 @@ class Project(object):
 
     def graph(self):
         G = nx.DiGraph()
+        stages = self.stages()
 
-        for stage in self.stages():
+        outs_map = {}
+        for stage in stages:
+            for o in stage.outs:
+                outs_map[o.path] = stage
+
+        for stage in stages:
             node = os.path.relpath(stage.path, self.root_dir)
             G.add_node(node, stage=stage)
             for dep in stage.deps:
-                dep_stage = dep.stage()
+                dep_stage = outs_map.get(dep.path, None)
                 if not dep_stage:
                     continue
                 dep_node = os.path.relpath(dep_stage.path, self.root_dir)