rebaseline_server: include setA/setB descriptions in output JSON

This is needed for rebaselining using the shared rebaseline_server instance:
by telling the client which git revision was used to fetch expectations, we
allow the client to pass that back along with new baselines (so the server
knows which revision to patch).

This is also handy in that it allows the server to tell the client more about the
different result sets (which files they were generated from).

BUG=skia:1918
NOTRY=true
R=rmistry@google.com

Author: epoger@google.com

Review URL: https://codereview.chromium.org/474813002

1 files changed, 53 insertions, 5 deletions

diff --git a/gm/rebaseline_server/compare_rendered_pictures.py b/gm/rebaseline_server/compare_rendered_pictures.py
index 85dff2711e..265f997de9 100755
--- a/gm/rebaseline_server/compare_rendered_pictures.py
+++ b/gm/rebaseline_server/compare_rendered_pictures.py
@@ -16,6 +16,7 @@ were generated from GMs or SKPs), and rename it accordingly.
 import logging
 import os
 import shutil
+import subprocess
 import tempfile
 import time
 
@@ -23,6 +24,7 @@ import time
 import fix_pythonpath  # pylint: disable=W0611
 
 # Imports from within Skia
+from py.utils import git_utils
 from py.utils import gs_utils
 from py.utils import url_utils
 import buildbot_globals
@@ -148,15 +150,37 @@ class RenderedPicturesComparisons(results.BaseComparisons):
     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)
+
+      self._setA_descriptions = {
+          results.KEY__SET_DESCRIPTIONS__DIR: setA_dirs,
+          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__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, setA_section=setA_section,
-          setB_root=setB_root, setB_section=setB_section)
+          setA_root=setA_root, setB_root=setB_root,
+          setA_section=setA_section, setB_section=setB_section)
       if self._results:
         self._timestamp = int(time.time())
         logging.info('Number of download file collisions: %s' %
@@ -166,15 +190,18 @@ class RenderedPicturesComparisons(results.BaseComparisons):
     finally:
       shutil.rmtree(tempdir)
 
-  def _load_result_pairs(self, setA_root, setA_section, setB_root,
-                         setB_section):
+  def _load_result_pairs(self, setA_root, setB_root,
+                         setA_section, setB_section):
     """Loads all JSON image summaries from 2 directory trees and compares them.
 
+    TODO(stephana): This method is only called from within __init__(); it might
+    make more sense to just roll the content of this method into __init__().
+
     Args:
       setA_root: root directory containing JSON summaries of rendering results
+      setB_root: root directory containing JSON summaries of rendering results
       setA_section: which section (gm_json.JSONKEY_ACTUALRESULTS or
           gm_json.JSONKEY_EXPECTEDRESULTS) to load from the summaries in setA
-      setB_root: root directory containing JSON summaries of rendering results
       setB_section: which section (gm_json.JSONKEY_ACTUALRESULTS or
           gm_json.JSONKEY_EXPECTEDRESULTS) to load from the summaries in setB
 
@@ -400,3 +427,24 @@ class RenderedPicturesComparisons(results.BaseComparisons):
       shutil.copytree(repo_dir, dest_dir)
     else:
       shutil.copytree(source_dir, dest_dir)
+
+  def _get_repo_revision(self, source_dir, assert_if_not=None):
+    """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(
+          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