rebaseline_server: cache results in long-running ImageDiffDB instance

gm/rebaseline_server/server.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.
 
 HTTP server for our HTML rebaseline viewer.
 """
@@ skipping 26 matching lines @@
 # Imports from local dir
 #
 # pylint: disable=C0301
 # Note: we import results under a different name, to avoid confusion with the
 # Server.results() property. See discussion at
 # https://codereview.chromium.org/195943004/diff/1/gm/rebaseline_server/server.py#newcode44
 # pylint: enable=C0301
 import compare_configs
 import compare_to_expectations
 import download_actuals
+import imagediffdb
 import imagepairset
 import results as results_mod
 
 PATHSPLIT_RE = re.compile('/([^/]+)/(.+)')
 
 # A simple dictionary of file name extensions to MIME types. The empty string
 # entry is used as the default when no extension was given or if the extension
 # has no entry in this dictionary.
 MIME_TYPE_MAP = {'': 'application/octet-stream',
                  'html': 'text/html',
@@ skipping 169 matching lines @@
     _create_index(
         file_path=os.path.join(
             PARENT_DIRECTORY, STATIC_CONTENTS_SUBDIR, GENERATED_HTML_SUBDIR,
             "index.html"),
         config_pairs=config_pairs)
 
     # Reentrant lock that must be held whenever updating EITHER of:
     # 1. self._results
     # 2. the expected or actual results on local disk
     self.results_rlock = threading.RLock()
-    # self._results will be filled in by calls to update_results()
+
+    # These will be filled in by calls to update_results()
     self._results = None
+    self._image_diff_db = None
 
   @property
   def results(self):
     """ Returns the most recently generated results, or None if we don't have
     any valid results (update_results() has not completed yet). """
     return self._results
 
   @property
   def is_exported(self):
     """ Returns true iff HTTP clients on other hosts are allowed to access
@@ skipping 86 matching lines @@
       # updated expectations into a temp directory, and leaving the rest of
       # the checkout alone.  This could be done using "git show", or by
       # downloading individual expectation JSON files from
       # skia.googlesource.com .
       if self._reload_seconds:
         logging.info(
             'Updating expected GM results in %s by syncing Skia repo ...' %
             compare_to_expectations.DEFAULT_EXPECTATIONS_DIR)
         _run_command(['gclient', 'sync'], TRUNK_DIRECTORY)
 
+      if not self._image_diff_db:
+        self._image_diff_db = imagediffdb.ImageDiffDB(
+            storage_root=os.path.join(
+              PARENT_DIRECTORY, STATIC_CONTENTS_SUBDIR,
+              GENERATED_IMAGES_SUBDIR))
+
       self._results = compare_to_expectations.ExpectationComparisons(
+          image_diff_db=self._image_diff_db,
           actuals_root=self._actuals_dir,
-          generated_images_root=os.path.join(
-              PARENT_DIRECTORY, STATIC_CONTENTS_SUBDIR,
-              GENERATED_IMAGES_SUBDIR),
           diff_base_url=posixpath.join(
               os.pardir, STATIC_CONTENTS_SUBDIR, GENERATED_IMAGES_SUBDIR),
           builder_regex_list=self._builder_regex_list)
 
       json_dir = os.path.join(
           PARENT_DIRECTORY, STATIC_CONTENTS_SUBDIR, GENERATED_JSON_SUBDIR)
       if not os.path.isdir(json_dir):
         os.makedirs(json_dir)
 
       for config_pair in self._config_pairs:
@@ skipping 334 matching lines @@
                    json_filename=args.json_filename,
                    gm_summaries_bucket=args.gm_summaries_bucket,
                    port=args.port, export=args.export, editable=args.editable,
                    reload_seconds=args.reload, config_pairs=config_pairs,
                    builder_regex_list=args.builders)
   _SERVER.run()
 
 
 if __name__ == '__main__':
   main()