trychange.py can store patches in a Git repo

trychange.py

Index: trychange.py
diff --git a/trychange.py b/trychange.py
index f93d9a418778fd11c5cc52ac660952941ac88297..ccacc2dfdafb9f091a0d03430cbab9989386ba85 100755
--- a/trychange.py
+++ b/trychange.py
@@ -4,10 +4,11 @@
 # found in the LICENSE file.
 
 """Client-side script to send a try job to the try server. It communicates to
-the try server by either writting to a svn repository or by directly connecting
-to the server by HTTP.
+the try server by either writting to a svn/git repository or by directly
+connecting to the server by HTTP.
 """
 
+import contextlib
 import datetime
 import errno
 import getpass
@@ -70,6 +71,8 @@ Examples:
             -f include/b.h
 """
 
+GIT_PATCH_DIR_BASENAME = os.path.join('git-try', 'patches-git')
+GIT_BRANCH_FILE = 'branch'
 
 def DieWithError(message):
   print >> sys.stderr, message
@@ -164,7 +167,10 @@ class SCM(object):
       'port': self.GetCodeReviewSetting('TRYSERVER_HTTP_PORT'),
       'host': self.GetCodeReviewSetting('TRYSERVER_HTTP_HOST'),
       'svn_repo': self.GetCodeReviewSetting('TRYSERVER_SVN_URL'),
+      'git_repo': self.GetCodeReviewSetting('TRYSERVER_GIT_URL'),
       'project': self.GetCodeReviewSetting('TRYSERVER_PROJECT'),
+      # primarily for revision=auto
+      'revision': self.GetCodeReviewSetting('TRYSERVER_REVISION'),
       'root': self.GetCodeReviewSetting('TRYSERVER_ROOT'),
       'patchlevel': self.GetCodeReviewSetting('TRYSERVER_PATCHLEVEL'),
     }
@@ -410,7 +416,9 @@ def _GenTSBotSpec(checkouts, change, changed_files, options):
 
 
 def _ParseSendChangeOptions(bot_spec, options):
-  """Parse common options passed to _SendChangeHTTP and _SendChangeSVN."""
+  """Parse common options passed to _SendChangeHTTP, _SendChangeSVN and
+  _SendChangeGit.
+  """
   values = [
     ('user', options.user),
     ('name', options.name),
@@ -481,6 +489,45 @@ def _SendChangeHTTP(bot_spec, options):
     raise NoTryServerAccess('%s is unaccessible. Got:\n%s' % (url, response))
 
 
+@contextlib.contextmanager
+def _TempFilename(name, contents=None):
+  """Create a temporary directory, append the specified name and yield.
+
+  In contrast to NamedTemporaryFile, does not keep the file open.
+  Deletes the file on __exit__.
+  """
+  temp_dir = tempfile.mkdtemp(prefix=name)
+  try:
+    path = os.path.join(temp_dir, name)
+    if contents:
+      with open(path, 'w') as f:
+        f.write(contents)
+    yield path
+  finally:
+    shutil.rmtree(temp_dir, True)
+
+
+@contextlib.contextmanager
+def _PrepareDescriptionAndPatchFiles(description, options):
+  """Create temporary files with description and patch, yield execution,
+  and delete the files.
+
+  __enter__ called on the return value returns a tuple of patch_filename and
+  description_filename.
+
+  Args:
+    description: contents of description file.
+    options: patchset options object. Must have attributes: user,
+        name (of patch) and diff (contents of patch).
+  """
+  current_time = str(datetime.datetime.now()).replace(':', '.')
+  patch_basename = '%s.%s.%s.diff' % (Escape(options.user),
+                                      Escape(options.name), current_time)
+  with _TempFilename('description', description) as description_filename:
+    with _TempFilename(patch_basename, options.diff) as patch_filename:
+      yield patch_filename, description_filename
+
+
 def _SendChangeSVN(bot_spec, options):
   """Send a change to the try server by committing a diff file on a subversion
   server."""
@@ -497,45 +544,151 @@ def _SendChangeSVN(bot_spec, options):
   if options.dry_run:
     return
 
-  # Create a temporary directory, put a uniquely named file in it with the diff
-  # content and svn import that.
-  temp_dir = tempfile.mkdtemp()
-  temp_file = tempfile.NamedTemporaryFile()
-  try:
-    try:
-      # Description
-      temp_file.write(description)
-      temp_file.flush()
-
-      # Diff file
-      current_time = str(datetime.datetime.now()).replace(':', '.')
-      file_name = (Escape(options.user) + '.' + Escape(options.name) +
-                   '.%s.diff' % current_time)
-      full_path = os.path.join(temp_dir, file_name)
-      with open(full_path, 'wb') as f:
-        f.write(options.diff)
-
-      # Committing it will trigger a try job.
-      if sys.platform == "cygwin":
-        # Small chromium-specific issue here:
-        # git-try uses /usr/bin/python on cygwin but svn.bat will be used
-        # instead of /usr/bin/svn by default. That causes bad things(tm) since
-        # Windows' svn.exe has no clue about cygwin paths. Hence force to use
-        # the cygwin version in this particular context.
-        exe = "/usr/bin/svn"
-      else:
-        exe = "svn"
-      command = [exe, 'import', '-q', temp_dir, options.svn_repo, '--file',
-                 temp_file.name]
-      if scm.SVN.AssertVersion("1.5")[0]:
-        command.append('--no-ignore')
+  with _PrepareDescriptionAndPatchFiles(description, options) as (
+       patch_filename, description_filename):
+    if sys.platform == "cygwin":
+      # Small chromium-specific issue here:
+      # git-try uses /usr/bin/python on cygwin but svn.bat will be used
+      # instead of /usr/bin/svn by default. That causes bad things(tm) since
+      # Windows' svn.exe has no clue about cygwin paths. Hence force to use
+      # the cygwin version in this particular context.
+      exe = "/usr/bin/svn"
+    else:
+      exe = "svn"
+    patch_dir = os.path.dirname(patch_filename)
+    command = [exe, 'import', '-q', patch_dir, options.svn_repo, '--file',
+               description_filename]
+    if scm.SVN.AssertVersion("1.5")[0]:
+      command.append('--no-ignore')
 
+    try:
       subprocess2.check_call(command)
     except subprocess2.CalledProcessError, e:
       raise NoTryServerAccess(str(e))
-  finally:
-    temp_file.close()
-    shutil.rmtree(temp_dir, True)
+
+
+def _GetPatchGitRepo(git_url):
+  """Get a path to a Git repo with patches with latest changes,
+  associated with the given url.
+
+  Store patches in .git/git-try/patches-git directory, a git repo. If it
+  doesn't exist yet or its origin URL is different, then clean up and clone it.
+  If it existed before, then pull changes.
+
+  Does not support SVN repo.
+
+  Returns a path to the directory with patches.
+  """
+  git_dir = scm.GIT.GetGitDir(os.getcwd())
+  patch_dir = os.path.join(git_dir, GIT_PATCH_DIR_BASENAME)
+  def do_git(*args, **kwargs):
+    kwargs.setdefault('cwd', patch_dir)
+    return scm.GIT.Capture(list(args), **kwargs)
+
+  logging.info('Looking for git repo for patches')
+  # Is there already a repo with the expected url or should we clone?
+  clone = True
+  if os.path.exists(patch_dir) and scm.GIT.IsInsideWorkTree(patch_dir):
+    existing_url = scm.GIT.Capture(
+        ['config', '--local', 'remote.origin.url'],
+        cwd=patch_dir)
+    clone = existing_url != git_url
+
+  if clone:
+    if os.path.exists(patch_dir):
+      logging.info('Cleaning up')
+      shutil.rmtree(patch_dir, True)
+    logging.info('Cloning patch repo')
+    do_git('clone', git_url, GIT_PATCH_DIR_BASENAME, cwd=git_dir)
+    email = scm.GIT.GetEmail(cwd=os.getcwd())
+    do_git('config', '--local', 'user.email', email)
+  else:
+    if scm.GIT.IsWorkTreeDirty(patch_dir):
+      logging.info('Work dir is dirty: hard reset!')
+      do_git('reset', '--hard')
+    logging.info('Updating patch repo')
+    do_git('pull', 'origin', 'master')
+
+  return os.path.abspath(patch_dir)
+
+
+def _SendChangeGit(bot_spec, options):
+  """Send a change to the try server by committing a diff file to a GIT repo"""
+  if not options.git_repo:
+    raise NoTryServerAccess('Please use the --git_repo option to specify the '
+                            'try server git repository to connect to.')
+
+  values = _ParseSendChangeOptions(bot_spec, options)
+  comment_subject = '%s.%s' % (options.user, options.name)
+  comment_body = ''.join("%s=%s\n" % (k, v) for k, v in values)
+  description = '%s\n\n%s' % (comment_subject, comment_body)
+  logging.info('Sending by GIT')
+  logging.info(description)
+  logging.info(options.git_repo)
+  logging.info(options.diff)
+  if options.dry_run:
+    return
+
+  patch_dir = _GetPatchGitRepo(options.git_repo)
+  def do_git(*args):
+    return scm.GIT.Capture(list(args), cwd=patch_dir)
+  def add_and_commit(filename, comment_filename):
+    do_git('add', filename)
+    do_git('commit', '-F', comment_filename)
+
+  assert scm.GIT.IsInsideWorkTree(patch_dir)
+  assert not scm.GIT.IsWorkTreeDirty(patch_dir)
+
+  with _PrepareDescriptionAndPatchFiles(description, options) as (
+       patch_filename, description_filename):
+    logging.info('Committing patch')
+    target_branch = ('refs/tryserver/' +
+                     os.path.basename(patch_filename).replace(' ','-'))
+    target_filename = os.path.join(patch_dir, 'patch.diff')
+    branch_file = os.path.join(patch_dir, GIT_BRANCH_FILE)
+    try:
+      # Crete a new branch and put the patch there
+      do_git('checkout', '--orphan', target_branch)
+      do_git('reset')
+      do_git('clean', '-f')
+      shutil.copyfile(patch_filename, target_filename)
+      add_and_commit(target_filename, description_filename)
+      assert not scm.GIT.IsWorkTreeDirty(patch_dir)
+
+      # Update the branch file in the master
+      do_git('checkout', 'master')
+
+      def update_branch():
+        with open(branch_file, 'w') as f:
+          f.write(target_branch)
+        add_and_commit(branch_file, description_filename)
+      def push():
+        do_git('push', 'origin', 'master', target_branch)
+      def push_fixup():
+        do_git('fetch', 'origin')
+        do_git('reset', '--hard', 'origin/master')
+        update_branch()
+
+      update_branch()
+      logging.info('Pushing patch')
+      _retry(push, push_fixup)
+    except subprocess2.CalledProcessError, e:
+      do_git('checkout', 'master')
+      do_git('reset', '--hard', 'origin/master')
+      raise NoTryServerAccess(str(e))
+
+
+def _retry(action, fixup=None, attempts=3):
+  """Calls action until it passes without exceptions"""
+  for attempt in xrange(attempts):
+    try:
+      action()
+    except subprocess2.CalledProcessError:
+      is_last = attempt == attempts - 1
+      if is_last:
+        raise
+      if fixup:
+        fixup()
 
 
 def PrintSuccess(bot_spec, options):
@@ -651,7 +804,9 @@ def gen_parser(prog):
                          " and exit.  Do not send patch.  Like --dry_run"
                          " but less verbose.")
   group.add_option("-r", "--revision",
-                    help="Revision to use for the try job; default: the "
+                    help="Revision to use for the try job. If 'auto' is "
+                         "specified, it is resolved to the revision a patch is "
+                         "generated against (Git only). Default: the "
                          "revision will be determined by the try server; see "
                          "its waterfall for more info")
   group.add_option("-c", "--clobber", action="store_true",
@@ -737,6 +892,18 @@ def gen_parser(prog):
                    help="SVN url to use to write the changes in; --use_svn is "
                         "implied when using --svn_repo")
   parser.add_option_group(group)
+
+  group = optparse.OptionGroup(parser, "Access the try server with Git")
+  group.add_option("--use_git",
+                   action="store_const",
+                   const=_SendChangeGit,
+                   dest="send_patch",
+                   help="Use GIT to talk to the try server")
+  group.add_option("-G", "--git_repo",
+                   metavar="GIT_URL",
+                   help="GIT url to use to write the changes in; --use_git is "
+                        "implied when using --git_repo")
+  parser.add_option_group(group)
   return parser
 
 
@@ -805,7 +972,6 @@ def TryChange(argv,
   try:
     changed_files = None
     # Always include os.getcwd() in the checkout settings.
-    checkouts = []
     path = os.getcwd()
 
     file_list = []
@@ -819,12 +985,29 @@ def TryChange(argv,
       # Clear file list so that the correct list will be retrieved from the
       # upstream branch.
       file_list = []
-    checkouts.append(GuessVCS(options, path, file_list))
-    checkouts[0].AutomagicalSettings()
+
+    current_vcs = GuessVCS(options, path, file_list)
+    current_vcs.AutomagicalSettings()
+    options = current_vcs.options
+    vcs_is_git = type(current_vcs) is GIT
+
+    # So far, git_repo doesn't work with SVN
+    if options.git_repo and not vcs_is_git:
+      parser.error('--git_repo option is supported only for GIT repositories')
+
+    # If revision==auto, resolve it
+    if options.revision and options.revision.lower() == 'auto':
+      if not vcs_is_git:
+        parser.error('--revision=auto is supported only for GIT repositories')
+      options.revision = scm.GIT.Capture(
+          ['rev-parse', current_vcs.diff_against],
+          cwd=path)
+
+    checkouts = [current_vcs]
     for item in options.sub_rep:
       # Pass file_list=None because we don't know the sub repo's file list.
       checkout = GuessVCS(options,
-                          os.path.join(checkouts[0].checkout_root, item),
+                          os.path.join(current_vcs.checkout_root, item),
                           None)
       if checkout.checkout_root in [c.checkout_root for c in checkouts]:
         parser.error('Specified the root %s two times.' %
@@ -833,9 +1016,10 @@ def TryChange(argv,
 
     can_http = options.port and options.host
     can_svn = options.svn_repo
+    can_git = options.git_repo
     # If there was no transport selected yet, now we must have enough data to
     # select one.
-    if not options.send_patch and not (can_http or can_svn):
+    if not options.send_patch and not (can_http or can_svn or can_git):
       parser.error('Please specify an access method.')
 
     # Convert options.diff into the content of the diff.
@@ -913,23 +1097,30 @@ def TryChange(argv,
           print '  %s' % (bot[0])
       return 0
 
-    # Send the patch.
+    # Determine sending protocol
     if options.send_patch:
       # If forced.
-      options.send_patch(bot_spec, options)
-      PrintSuccess(bot_spec, options)
-      return 0
-    try:
-      if can_http:
-        _SendChangeHTTP(bot_spec, options)
+      senders = [options.send_patch]
+    else:
+      # Try sending patch using avaialble protocols
+      all_senders = [
+        (_SendChangeHTTP, can_http),
+        (_SendChangeSVN, can_svn),
+        (_SendChangeGit, can_git)
+      ]
+      senders = [sender for sender, can in all_senders if can]
+
+    # Send the patch.
+    for sender in senders:
+      try:
+        sender(bot_spec, options)
         PrintSuccess(bot_spec, options)
         return 0
-    except NoTryServerAccess:
-      if not can_svn:
-        raise
-    _SendChangeSVN(bot_spec, options)
-    PrintSuccess(bot_spec, options)
-    return 0
+      except NoTryServerAccess:
+        is_last = sender == senders[-1]
+        if is_last:
+          raise
+    assert False, "Unreachable code"
   except (InvalidScript, NoTryServerAccess), e:
     if swallow_exception:
       return 1