rebaseline_server: cache results in long-running ImageDiffDB instance

gm/rebaseline_server/imagediffdb.py

 #!/usr/bin/python
 
 """
 Copyright 2013 Google Inc.
 
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 
 Calulate differences between image pairs, and store them in a database.
 """
@@ skipping 203 matching lines @@
     """
     Args:
       storage_root: string; root path within the DB will store all of its stuff
     """
     self._storage_root = storage_root
 
     # Dictionary of DiffRecords, keyed by (expected_image_locator,
     # actual_image_locator) tuples.
     self._diff_dict = {}
 
+  def get_storage_root(self):

[rmistry, 2014/07/09 13:14:04]

[Optional] Can also do:

@property
def storage_root(self):
  return self._storage_root

http://stackoverflow.com/questions/6618002/python-property-versus-getters-and...

[epoger, 2014/07/09 14:57:36]

Good point.  Fixed this one, and added a TODO for others in this file.

+    return self._storage_root
+
   def add_image_pair(self,
                      expected_image_url, expected_image_locator,
                      actual_image_url, actual_image_locator):
     """Download this pair of images (unless we already have them on local disk),
     and prepare a DiffRecord for them.
 
     TODO(epoger): Make this asynchronously download images, rather than blocking
     until the images have been downloaded and processed.
     When we do that, we should probably add a new method that will block
     until all of the images have been downloaded and processed.  Otherwise,
@@ skipping 90 matching lines @@
 
   Args:
     expected_image_locator: locator string pointing at expected image
     actual_image_locator: locator string pointing at actual image
 
   Returns: already-sanitized locator where the diffs between expected and
       actual images can be found
   """
   return "%s-vs-%s" % (_sanitize_locator(expected_image_locator),
                        _sanitize_locator(actual_image_locator))