rebaseline_server: serve JSON from static file, rather than generating it live

gm/rebaseline_server/imagepairset.py

 #!/usr/bin/python
 

[epoger, 2014/03/19 21:13:51]

Reason for the change: We want to be able to store lots of different image diff
summaries anywhere (Google Storage, local disk, etc.) and review them anytime,
rather than requiring a rebaseline_server process to be running.  This takes us
a step in that direction.

 """
 Copyright 2014 Google Inc.
 
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 
 ImagePairSet class; see its docstring below.
 """
 
 # System-level imports
 import posixpath
 
 # Local imports
 import column
 
 # Keys used within dictionary representation of ImagePairSet.
 # NOTE: Keep these in sync with static/constants.js
 KEY__EXTRACOLUMNHEADERS = 'extraColumnHeaders'
 KEY__IMAGEPAIRS = 'imagePairs'
 KEY__IMAGESETS = 'imageSets'
 KEY__IMAGESETS__FIELD__BASE_URL = 'baseUrl'
 KEY__IMAGESETS__FIELD__DESCRIPTION = 'description'
 KEY__IMAGESETS__SET__DIFFS = 'diffs'
 KEY__IMAGESETS__SET__IMAGE_A = 'imageA'
 KEY__IMAGESETS__SET__IMAGE_B = 'imageB'
 KEY__IMAGESETS__SET__WHITEDIFFS = 'whiteDiffs'
 
 DEFAULT_DESCRIPTIONS = ('setA', 'setB')
-DIFF_BASE_URL = '/static/generated-images'
 
 
 class ImagePairSet(object):
   """A collection of ImagePairs, representing two arbitrary sets of images.
 
   These could be:
   - images generated before and after a code patch
   - expected and actual images for some tests
   - or any other pairwise set of images.
   """
 
-  def __init__(self, descriptions=None):
+  def __init__(self, diff_base_url, descriptions=None):
     """
     Args:
+      diff_base_url: base URL indicating where diff images can be loaded from
       descriptions: a (string, string) tuple describing the two image sets.
           If not specified, DEFAULT_DESCRIPTIONS will be used.
     """
     self._column_header_factories = {}
     self._descriptions = descriptions or DEFAULT_DESCRIPTIONS
     self._extra_column_tallies = {}  # maps column_id -> values
                                      #                -> instances_per_value
     self._image_pair_dicts = []
     self._image_base_url = None
-    self._diff_base_url = DIFF_BASE_URL
+    self._diff_base_url = diff_base_url
 
   def add_image_pair(self, image_pair):
     """Adds an ImagePair; this may be repeated any number of times."""
     # Special handling when we add the first ImagePair...
     if not self._image_pair_dicts:
       self._image_base_url = image_pair.base_url
 
     if image_pair.base_url != self._image_base_url:
       raise Exception('added ImagePair with base_url "%s" instead of "%s"' % (
           image_pair.base_url, self._image_base_url))
@@ skipping 91 matching lines @@
                 key_base_url: posixpath.join(
                     self._diff_base_url, 'diffs'),
             },
             KEY__IMAGESETS__SET__WHITEDIFFS: {
                 key_description: 'differing pixels in white',
                 key_base_url: posixpath.join(
                     self._diff_base_url, 'whitediffs'),
             },
         },
     }