1#!/usr/bin/python
2# Copyright 2014 Google Inc.
3#
4# Use of this source code is governed by a BSD-style license that can be
5# found in the LICENSE file.
6
7
8"""Parse a DEPS file and git checkout all of the dependencies.
9
10Args:
11  An optional list of deps_os values.
12
13Environment Variables:
14  GIT_EXECUTABLE: path to "git" binary; if unset, will look for one of
15  ['git', 'git.exe', 'git.bat'] in your default path.
16
17  GIT_SYNC_DEPS_PATH: file to get the dependency list from; if unset,
18  will use the file ../DEPS relative to this script's directory.
19
20  GIT_SYNC_DEPS_QUIET: if set to non-empty string, suppress messages.
21
22Git Config:
23  To disable syncing of a single repository:
24      cd path/to/repository
25      git config sync-deps.disable true
26
27  To re-enable sync:
28      cd path/to/repository
29      git config --unset sync-deps.disable
30"""
31
32
33import os
34import subprocess
35import sys
36import threading
37
38
39def git_executable():
40  """Find the git executable.
41
42  Returns:
43      A string suitable for passing to subprocess functions, or None.
44  """
45  envgit = os.environ.get('GIT_EXECUTABLE')
46  searchlist = ['git', 'git.exe', 'git.bat']
47  if envgit:
48    searchlist.insert(0, envgit)
49  with open(os.devnull, 'w') as devnull:
50    for git in searchlist:
51      try:
52        subprocess.call([git, '--version'], stdout=devnull)
53      except (OSError,):
54        continue
55      return git
56  return None
57
58
59DEFAULT_DEPS_PATH = os.path.normpath(
60  os.path.join(os.path.dirname(__file__), os.pardir, 'DEPS'))
61
62
63def usage(deps_file_path = None):
64  sys.stderr.write(
65    'Usage: run to grab dependencies, with optional platform support:\n')
66  sys.stderr.write('  python %s' % __file__)
67  if deps_file_path:
68    for deps_os in parse_file_to_dict(deps_file_path)['deps_os']:
69      sys.stderr.write(' [%s]' % deps_os)
70  else:
71    sys.stderr.write(' [DEPS_OS...]')
72  sys.stderr.write('\n\n')
73  sys.stderr.write(__doc__)
74
75
76def git_repository_sync_is_disabled(git, directory):
77  try:
78    disable = subprocess.check_output(
79      [git, 'config', 'sync-deps.disable'], cwd=directory)
80    return disable.lower().strip() in ['true', '1', 'yes', 'on']
81  except subprocess.CalledProcessError:
82    return False
83
84
85def is_git_toplevel(git, directory):
86  """Return true iff the directory is the top level of a Git repository.
87
88  Args:
89    git (string) the git executable
90
91    directory (string) the path into which the repository
92              is expected to be checked out.
93  """
94  try:
95    toplevel = subprocess.check_output(
96      [git, 'rev-parse', '--show-toplevel'], cwd=directory).strip()
97    return os.path.realpath(directory) == os.path.realpath(toplevel)
98  except subprocess.CalledProcessError:
99    return False
100
101
102def git_checkout_to_directory(git, repo, checkoutable, directory, verbose):
103  """Checkout (and clone if needed) a Git repository.
104
105  Args:
106    git (string) the git executable
107
108    repo (string) the location of the repository, suitable
109         for passing to `git clone`.
110
111    checkoutable (string) a tag, branch, or commit, suitable for
112                 passing to `git checkout`
113
114    directory (string) the path into which the repository
115              should be checked out.
116
117    verbose (boolean)
118
119  Raises an exception if any calls to git fail.
120  """
121  if not os.path.isdir(directory):
122    subprocess.check_call(
123      [git, 'clone', '--quiet', repo, directory])
124
125  if not is_git_toplevel(git, directory):
126    # if the directory exists, but isn't a git repo, you will modify
127    # the parent repostory, which isn't what you want.
128    sys.stdout.write('%s\n  IS NOT TOP-LEVEL GIT DIRECTORY.\n' % directory)
129    return
130
131  # Check to see if this repo is disabled.  Quick return.
132  if git_repository_sync_is_disabled(git, directory):
133    sys.stdout.write('%s\n  SYNC IS DISABLED.\n' % directory)
134    return
135
136  subprocess.check_call([git, 'fetch', '--quiet'], cwd=directory)
137
138  subprocess.check_call(
139    [git, 'checkout', '--quiet', checkoutable], cwd=directory)
140
141  if verbose:
142    sys.stdout.write('%s\n  @ %s\n' % (directory, checkoutable))  # Success.
143
144
145def parse_file_to_dict(path):
146  dictionary = {}
147  execfile(path, dictionary)
148  return dictionary
149
150
151def git_sync_deps(deps_file_path, command_line_os_requests, verbose):
152  """Grab dependencies, with optional platform support.
153
154  Args:
155    deps_file_path (string) Path to the DEPS file.
156
157    command_line_os_requests (list of strings) Can be empty list.
158        List of strings that should each be a key in the deps_os
159        dictionary in the DEPS file.
160
161  Raises git Exceptions.
162  """
163  git = git_executable()
164  assert git
165
166  deps_file_directory = os.path.dirname(deps_file_path)
167  deps_file = parse_file_to_dict(deps_file_path)
168  dependencies = deps_file['deps'].copy()
169  os_specific_dependencies = deps_file.get('deps_os', [])
170  for os_name in command_line_os_requests:
171    # Add OS-specific dependencies
172    if os_name in os_specific_dependencies:
173      dependencies.update(os_specific_dependencies[os_name])
174  list_of_arg_lists = []
175  for directory in dependencies:
176    if '@' in dependencies[directory]:
177      repo, checkoutable = dependencies[directory].split('@', 1)
178    else:
179      repo, checkoutable = dependencies[directory], 'origin/master'
180
181    relative_directory = os.path.join(deps_file_directory, directory)
182
183    list_of_arg_lists.append(
184      (git, repo, checkoutable, relative_directory, verbose))
185
186  multithread(git_checkout_to_directory, list_of_arg_lists)
187
188  for directory in deps_file.get('recursedeps', []):
189    recursive_path = os.path.join(deps_file_directory, directory, 'DEPS')
190    git_sync_deps(recursive_path, command_line_os_requests, verbose)
191
192
193def multithread(function, list_of_arg_lists):
194  # for args in list_of_arg_lists:
195  #   function(*args)
196  # return
197  threads = []
198  for args in list_of_arg_lists:
199    thread = threading.Thread(None, function, None, args)
200    thread.start()
201    threads.append(thread)
202  for thread in threads:
203    thread.join()
204
205
206def main(argv):
207  deps_file_path = os.environ.get('GIT_SYNC_DEPS_PATH', DEFAULT_DEPS_PATH)
208  verbose = not bool(os.environ.get('GIT_SYNC_DEPS_QUIET', False))
209
210  if '--help' in argv or '-h' in argv:
211    usage(deps_file_path)
212    return 1
213
214  git_sync_deps(deps_file_path, argv, verbose)
215  return 0
216
217
218if __name__ == '__main__':
219  exit(main(sys.argv[1:]))
220