Give git map-branches extra information behind -v and -vv flags.

git_common.py

 # Copyright 2014 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.
 
 # Monkeypatch IMapIterator so that Ctrl-C can kill everything properly.
 # Derived from https://gist.github.com/aljungberg/626518
 import multiprocessing.pool
 from multiprocessing.pool import IMapIterator
 def wrapper(func):
   def wrap(self, timeout=None):
@@ skipping 73 matching lines @@
     # crbug.com/315421
     r'The requested URL returned error: 500 while accessing',
 
     # crbug.com/388876
     r'Connection timed out',
 )
 
 GIT_TRANSIENT_ERRORS_RE = re.compile('|'.join(GIT_TRANSIENT_ERRORS),
                                      re.IGNORECASE)
 
+# First version where the for-each-ref command's format string supported the
+# upstream:track token.
+MIN_UPSTREAM_TRACK_GIT_VERSION = (1, 9)
 
 class BadCommitRefException(Exception):
   def __init__(self, refs):
     msg = ('one of %s does not seem to be a valid commitref.' %
            str(refs))
     super(BadCommitRefException, self).__init__(msg)
 
 
 def memoize_one(**kwargs):
   """Memoizes a single-argument pure function.
@@ skipping 325 matching lines @@
     base = actual_merge_base
     manual_merge_base(branch, base, parent)
 
   return base
 
 
 def hash_multi(*reflike):
   return run('rev-parse', *reflike).splitlines()
 
 
-def hash_one(reflike):
-  return run('rev-parse', reflike)
+def hash_one(reflike, short=False):
+  args = ['rev-parse', reflike]
+  if short:
+    args.insert(1, '--short')
+  return run(*args)
 
 
 def in_rebase():
   git_dir = run('rev-parse', '--git-dir')
   return (
     os.path.exists(os.path.join(git_dir, 'rebase-merge')) or
     os.path.exists(os.path.join(git_dir, 'rebase-apply')))
 
 
 def intern_f(f, kind='blob'):
@@ skipping 258 matching lines @@
     return None
   return ret
 
 
 def upstream(branch):
   try:
     return run('rev-parse', '--abbrev-ref', '--symbolic-full-name',
                branch+'@{upstream}')
   except subprocess2.CalledProcessError:
     return None
+
+def get_git_version():
+  """Returns a tuple that contains the numeric components of the current git
+  version."""
+  version_string = run('--version')
+  version_match = re.search(r'(\d+.)+(\d+)', version_string)
+  version = version_match.group() if version_match else ''
+
+  return tuple(int(x) for x in version.split('.'))
+
+
+def get_all_tracking_info():
+  format_string = (
+      '--format=%(refname:short):%(objectname:short):%(upstream:short):')
+
+  # This is not covered by the depot_tools CQ which only has git version 1.8.
+  if get_git_version() >= MIN_UPSTREAM_TRACK_GIT_VERSION:  # pragma: no cover
+    format_string += '%(upstream:track)'
+
+  info_map = {}
+  data = run('for-each-ref', format_string, 'refs/heads')
+  TrackingInfo = collections.namedtuple(
+      'TrackingInfo', 'hash upstream ahead behind')
+  for line in data.splitlines():
+    (branch, branch_hash, upstream_branch, tracking_status) = line.split(':')
+
+    ahead_match = re.search(r'ahead (\d+)', tracking_status)
+    ahead = int(ahead_match.group(1)) if ahead_match else None
+
+    behind_match = re.search(r'behind (\d+)', tracking_status)
+    behind = int(behind_match.group(1)) if behind_match else None
+
+    info_map[branch] = TrackingInfo(
+        hash=branch_hash, upstream=upstream_branch, ahead=ahead, behind=behind)
+
+  # Set None for upstreams which are not branches (e.g empty upstream, remotes
+  # and deleted upstream branches).
+  missing_upstreams = {}
+  for info in info_map.values():
+    if info.upstream not in info_map and info.upstream not in missing_upstreams:
+      missing_upstreams[info.upstream] = None
+
+  return dict(info_map.items() + missing_upstreams.items())