rebaseline_server: constrain setADir/setBDir to consistently refer to single directories, not lists

gm/rebaseline_server/compare_rendered_pictures.py

 #!/usr/bin/python
 
 """
 Copyright 2014 Google Inc.
 
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 
 Compare results of two render_pictures runs.
 
@@ skipping 67 matching lines @@
     gm_json.JSONKEY_ACTUALRESULTS,
     gm_json.JSONKEY_EXPECTEDRESULTS,
 ]
 
 
 class RenderedPicturesComparisons(results.BaseComparisons):
   """Loads results from multiple render_pictures runs into an ImagePairSet.
   """
 
   def __init__(self,
-               setA_dirs, setB_dirs,
+               setA_dir, setB_dir,
                setA_section, setB_section,
                image_diff_db,
                image_base_gs_url=DEFAULT_IMAGE_BASE_GS_URL, diff_base_url=None,
                setA_label=None, setB_label=None,
                gs=None, truncate_results=False, prefetch_only=False,
                download_all_images=False):
     """Constructor: downloads images and generates diffs.
 
     Once the object has been created (which may take a while), you can call its
     get_packaged_results_of_type() method to quickly retrieve the results...
     unless you have set prefetch_only to True, in which case we will
     asynchronously warm up the ImageDiffDB cache but not fill in self._results.
 
     Args:
-      setA_dirs: list of root directories to copy all JSON summaries from,
-          and to use as setA within the comparisons. These directories may be
-          gs:// URLs, special "repo:" URLs, or local filepaths.
-      setB_dirs: list of root directories to copy all JSON summaries from,
-          and to use as setB within the comparisons. These directories may be
-          gs:// URLs, special "repo:" URLs, or local filepaths.
+      setA_dir: root directory to copy all JSON summaries from, and to use as
+          setA within the comparisons. This directory may be specified as a
+          gs:// URL, special "repo:" URL, or local filepath.
+      setB_dir: root directory to copy all JSON summaries from, and to use as
+          setB within the comparisons. This directory may be specified as a
+          gs:// URL, special "repo:" URL, or local filepath.
       setA_section: which section within setA to examine; must be one of
           ALLOWED_SECTION_NAMES
       setB_section: which section within setB to examine; must be one of
           ALLOWED_SECTION_NAMES
       image_diff_db: ImageDiffDB instance
       image_base_gs_url: "gs://" URL pointing at the Google Storage bucket/dir
           under which all render_pictures result images can
           be found; this will be used to read images for comparison within
           this code, and included in the ImagePairSet (as an HTTP URL) so its
           consumers know where to download the images from
@@ skipping 33 matching lines @@
       self._setA_label = setA_label or setA_section
       self._setB_label = setB_label or setB_section
     else:
       self._setA_label = setA_label or 'setA'
       self._setB_label = setB_label or 'setB'
 
     tempdir = tempfile.mkdtemp()
     try:
       setA_root = os.path.join(tempdir, 'setA')
       setB_root = os.path.join(tempdir, 'setB')
-      setA_repo_revision = None
-      setB_repo_revision = None
-      for source_dir in setA_dirs:
-        self._copy_dir_contents(source_dir=source_dir, dest_dir=setA_root)
-        # TODO(stephana): There is a potential race condition here... we copy
-        # the contents out of the source_dir, and THEN we get the commithash
-        # of source_dir.  If source_dir points at a git checkout, and that
-        # checkout is updated (by a different thread/process) during this
-        # operation, then the contents and commithash will be out of sync.
-        setA_repo_revision = self._get_repo_revision(
-            source_dir=source_dir, assert_if_not=setA_repo_revision)
-      for source_dir in setB_dirs:
-        self._copy_dir_contents(source_dir=source_dir, dest_dir=setB_root)
-        setB_repo_revision = self._get_repo_revision(
-            source_dir=source_dir, assert_if_not=setB_repo_revision)
+      # TODO(stephana): There is a potential race condition here... we copy
+      # the contents out of the source_dir, and THEN we get the commithash
+      # of source_dir.  If source_dir points at a git checkout, and that
+      # checkout is updated (by a different thread/process) during this
+      # operation, then the contents and commithash will be out of sync.
+      self._copy_dir_contents(source_dir=setA_dir, dest_dir=setA_root)
+      setA_repo_revision = self._get_repo_revision(source_dir=setA_dir)
+      self._copy_dir_contents(source_dir=setB_dir, dest_dir=setB_root)
+      setB_repo_revision = self._get_repo_revision(source_dir=setB_dir)
 
       self._setA_descriptions = {
-          results.KEY__SET_DESCRIPTIONS__DIR: setA_dirs,
+          results.KEY__SET_DESCRIPTIONS__DIR: setA_dir,
           results.KEY__SET_DESCRIPTIONS__REPO_REVISION: setA_repo_revision,
           results.KEY__SET_DESCRIPTIONS__SECTION: setA_section,
       }
       self._setB_descriptions = {
-          results.KEY__SET_DESCRIPTIONS__DIR: setB_dirs,
+          results.KEY__SET_DESCRIPTIONS__DIR: setB_dir,
           results.KEY__SET_DESCRIPTIONS__REPO_REVISION: setB_repo_revision,
           results.KEY__SET_DESCRIPTIONS__SECTION: setB_section,
       }
 
       time_start = int(time.time())
       self._results = self._load_result_pairs(
           setA_root=setA_root, setB_root=setB_root,
           setA_section=setA_section, setB_section=setB_section)
       if self._results:
         self._timestamp = int(time.time())
@@ skipping 266 matching lines @@
     if gs_utils.GSUtils.is_gs_url(source_dir):
       (bucket, path) = gs_utils.GSUtils.split_gs_url(source_dir)
       self._gs.download_dir_contents(source_bucket=bucket, source_dir=path,
                                      dest_dir=dest_dir)
     elif source_dir.lower().startswith(REPO_URL_PREFIX):
       repo_dir = os.path.join(REPO_BASEPATH, source_dir[len(REPO_URL_PREFIX):])
       shutil.copytree(repo_dir, dest_dir)
     else:
       shutil.copytree(source_dir, dest_dir)
 
-  def _get_repo_revision(self, source_dir, assert_if_not=None):
+  def _get_repo_revision(self, source_dir):
     """Get the commit hash of source_dir, IF it refers to a git checkout.
 
     Args:
       source_dir: path to source dir (GS URL, local filepath, or a special
           "repo:" URL type that points at a file within our Skia checkout;
           only the "repo:" URL type will have a commit hash.
-      assert_if_not: if not None, raise an Exception if source_dir has a
-          commit hash and that hash is not equal to this
     """
     if source_dir.lower().startswith(REPO_URL_PREFIX):
       repo_dir = os.path.join(REPO_BASEPATH, source_dir[len(REPO_URL_PREFIX):])
-      revision = subprocess.check_output(
+      return subprocess.check_output(
           args=[git_utils.GIT, 'rev-parse', 'HEAD'], cwd=repo_dir).strip()
-      if assert_if_not and revision != assert_if_not:
-        raise Exception('found revision %s that did not match %s' % (
-            revision, assert_if_not))
-      return revision
     else:
       return None