Update bisect_lib with the changes committed in the infra/build repo.

experimental/bisect_lib/fetch_intervening_revisions.py

Index: experimental/bisect_lib/fetch_intervening_revisions.py
diff --git a/experimental/bisect_lib/fetch_intervening_revisions.py b/experimental/bisect_lib/fetch_intervening_revisions.py
new file mode 100755
index 0000000000000000000000000000000000000000..6b86ca243ea369296e6ca72b2ea7da84bb16b12c
--- /dev/null
+++ b/experimental/bisect_lib/fetch_intervening_revisions.py
@@ -0,0 +1,102 @@
+#!/usr/bin/python
+#
+# Copyright 2015 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Gets list of revisions between two commits and their commit positions.
+
+Example usage:
+  ./fetchInterveningRevisions.py 343b531d31 7b43807df3 chromium
+  ./fetchInterveningRevisions.py 235eff9574 1e4681c33f v8
+
+Note: Another implementation of this functionality can be found in
+findit/common/gitRepository.py (https://goo.gl/Rr8j9O).
+"""
+
+import argparse
+import json
+import os
+import re
+import sys
+import urllib2
+
+import depot_map  # pylint: disable=relative-import
+
+_GITILES_PADDING = ')]}\'\n'
+_URL_TEMPLATE = ('https://chromium.googlesource.com/%s/+log/%s..%s'
+                 '?format=json&n=%d')
+
+# Gitiles paginates the list of commits; since we want to get all of the
+# commits at once, the page size should be larger than the largest revision
+# range that we expect to get.
+_PAGE_SIZE = 512
+
+def FetchInterveningRevisions(start, end, depot_name):
+  """Fetches a list of revision in between two commits.
+
+  Args:
+    start (str): A git commit hash in the Chromium src repository.
+    end (str): Another git commit hash, after start.
+    depot_name (str): A respository name.
+
+  Returns:
+    A list of pairs (commit hash, commit position), from earliest to latest,
+    for all commits in between the two given commits, not including either
+    of the given commits.
+
+  Raises:
+    urllib2.URLError: The request to gitiles failed.
+    ValueError: The response wasn't valid JSON.
+    KeyError: The JSON didn't contain the expected data.
+  """
+  revisions = _FetchRangeFromGitiles(start, end, depot_name)
+  # The response from gitiles includes the end revision and is ordered
+  # from latest to earliest.
+  return [_CommitPair(r) for r in reversed(revisions[1:])]
+
+
+def _FetchRangeFromGitiles(start, end, depot_name):
+  """Fetches a list of revision dicts from gitiles.
+
+  Make multiple requests to get multiple pages, if necessary.
+  """
+  revisions = []
+  url = _URL_TEMPLATE % (
+      depot_map.DEPOT_PATH_MAP[depot_name], start, end, _PAGE_SIZE)
+  current_page_url = url
+  while True:
+    response = urllib2.urlopen(current_page_url).read()
+    response_json = response[len(_GITILES_PADDING):]  # Remove padding.
+    response_dict = json.loads(response_json)
+    revisions.extend(response_dict['log'])
+    if 'next' not in response_dict:
+      break
+    current_page_url = url + '&s=' + response_dict['next']
+  return revisions
+
+
+def _CommitPair(commit_dict):
+  return (commit_dict['commit'],
+          _CommitPositionFromMessage(commit_dict['message']))
+
+
+def _CommitPositionFromMessage(message):
+  for line in reversed(message.splitlines()):
+    if line.startswith('Cr-Commit-Position:'):
+      return line.split('#')[1].split('}')[0]
+  return None
+
+
+def Main():
+  parser = argparse.ArgumentParser()
+  parser.addArgument('start')
+  parser.addArgument('end')
+  parser.addArgument('depot', choices=list(depot_map.DEPOT_PATH_MAP))
+  args = parser.parseArgs()
+  revision_pairs = FetchInterveningRevisions(args.start, args.end, args.depot)
+  print json.dumps(revision_pairs)
+
+
+if __name__ == '__main__':
+  Main()