svndiff.py: add ability to compare before-and-after JSON files, not just raw images

tools/rebaseline_imagefiles.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.
 '''
 
 '''
 Rebaselines GM test results as individual image files
 (the "old way", before https://goto.google.com/ChecksumTransitionDetail ).
 
 Once we have switched our expectations to JSON form for all platforms,
 we can delete this file.
 
 There is a lot of code duplicated between here and rebaseline.py, but
 that's fine because we will delete this file soon.
+
+TODO(epoger): Fix indentation in this file (2-space indents, not 4-space).
 '''
 
 # System-level imports
 import os
 import re
 import subprocess
 import sys
 import urllib2
 
 # Imports from within Skia
@@ skipping 41 matching lines @@
                  add_new=False, missing_json_is_fatal=False):
         self._expectations_root = expectations_root
         self._tests = tests
         self._configs = configs
         self._json_base_url = json_base_url
         self._json_filename = json_filename
         self._exception_handler = exception_handler
         self._dry_run = dry_run
         self._add_new = add_new
         self._missing_json_is_fatal = missing_json_is_fatal
-        self._googlestorage_gm_actuals_root = (
-            'http://chromium-skia-gm.commondatastorage.googleapis.com/gm')
-        self._testname_pattern = re.compile('(\S+)_(\S+).png')
+        self._image_filename_re = re.compile(gm_json.IMAGE_FILENAME_PATTERN)
         self._is_svn_checkout = (
             os.path.exists(os.path.join(expectations_root, '.svn')) or
             os.path.exists(os.path.join(expectations_root, os.pardir, '.svn')))
         self._is_git_checkout = (
             os.path.exists(os.path.join(expectations_root, '.git')) or
             os.path.exists(os.path.join(expectations_root, os.pardir, '.git')))
 
     # If dry_run is False, execute subprocess.call(cmd).
     # If dry_run is True, print the command we would have otherwise run.
     # Raises a CommandFailedException if the command fails.
     def _Call(self, cmd):
         if self._dry_run:
             print '%s' % ' '.join(cmd)
             return
         if subprocess.call(cmd) != 0:
             raise CommandFailedException('error running command: ' +
                                          ' '.join(cmd))
 
     # Download a single actual result from GoogleStorage.
     # Raises an exception if it fails.
     def _DownloadFromGoogleStorage(self, infilename, outfilename, all_results):
-        test_name = self._testname_pattern.match(infilename).group(1)
+        test_name = self._image_filename_re.match(infilename).group(1)
         if not test_name:
             raise Exception('unable to find test_name for infilename %s' %
                             infilename)
         try:
             hash_type, hash_value = all_results[infilename]
         except KeyError:
             raise Exception('unable to find filename %s in all_results dict' %
                             infilename)
         except ValueError as e:
             raise Exception(
                 'ValueError reading filename %s from all_results dict: %s' % (
                     infilename, e))
-        url = '%s/%s/%s/%s.png' % (self._googlestorage_gm_actuals_root,
-                                   hash_type, test_name, hash_value)
+        url = gm_json.CreateGmActualUrl(
+            test_name=test_name, hash_type=hash_type, hash_digest=hash_value)
         try:
             self._DownloadFile(source_url=url, dest_filename=outfilename)
         except CommandFailedException:
             raise Exception('Couldn\'t fetch gs_url %s as outfile %s' % (
                 url, outfilename))
 
     # Download a single file, raising a CommandFailedException if it fails.
     def _DownloadFile(self, source_url, dest_filename):
         # Download into a temporary file and then rename it afterwards,
         # so that we don't corrupt the existing file if it fails midway thru.
@@ skipping 134 matching lines @@
             return
 
         json_url = '/'.join([self._json_base_url,
                              subdir, builder, subdir,
                              self._json_filename])
         all_results = self._GetActualResults(json_url=json_url)
         filenames = self._GetFilesToRebaseline(json_url=json_url,
                                                add_new=self._add_new)
         skipped_files = []
         for filename in filenames:
-            (test, config) = self._testname_pattern.match(filename).groups()
+            (test, config) = self._image_filename_re.match(filename).groups()
             if self._tests:
                 if test not in self._tests:
                     skipped_files.append(filename)
                     continue
             if self._configs:
                 if config not in self._configs:
                     skipped_files.append(filename)
                     continue
             outfilename = os.path.join(self._expectations_root, subdir,
                                        filename);
             try:
                 self._RebaselineOneFile(expectations_subdir=subdir,
                                         builder_name=builder,
                                         infilename=filename,
                                         outfilename=outfilename,
                                         all_results=all_results)
             except BaseException as e:
                 self._exception_handler.RaiseExceptionOrContinue(e)