Python fallback for git cache bootstrap

git_cache.py

 #!/usr/bin/env python
 # 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.
 
 """A git command for managing a local cache of git repositories."""
 
 from __future__ import print_function
 import errno
 import logging
 import optparse
 import os
 import tempfile
 import time
 import subprocess
 import sys
 import urlparse
+import zipfile
 
 from download_from_google_storage import Gsutil
 import gclient_utils
 import subcommand
 
 try:
   # pylint: disable=E0602
   WinErr = WindowsError
 except NameError:
   class WinErr(Exception):
@@ skipping 187 matching lines @@
                  '+refs/heads/*:refs/heads/*'], cwd=cwd)
     for ref in self.refs:
       ref = ref.lstrip('+').rstrip('/')
       if ref.startswith('refs/'):
         refspec = '+%s:%s' % (ref, ref)
       else:
         refspec = '+refs/%s/*:refs/%s/*' % (ref, ref)
       self.RunGit(['config', '--add', 'remote.origin.fetch', refspec], cwd=cwd)
 
   def bootstrap_repo(self, directory):
-    """Bootstrap the repo from Google Stroage if possible.
+    """Bootstrap the repo from Google Stroage if possible."""
 
-    Requires 7z on Windows and Unzip on Linux/Mac.
-    """
-    if sys.platform.startswith('win'):
-      if not self.FindExecutable('7z'):
-        self.print('''
-Cannot find 7z in the path.  If you want git cache to be able to bootstrap from
-Google Storage, please install 7z from:
-
-http://www.7-zip.org/download.html
-''')
-        return False
-    else:
-      if not self.FindExecutable('unzip'):
-        self.print('''
-Cannot find unzip in the path.  If you want git cache to be able to bootstrap
-from Google Storage, please ensure unzip is present on your system.
-''')
-        return False
+    python_fallback = False
+    if sys.platform.startswith('win') and not self.FindExecutable('7z'):
+      python_fallback = True
+    elif sys.platform.startswith('darwin'):
+      # The OSX version of unzip doesn't support zip64.
+      python_fallback = True
+    elif not self.FindExecutable('unzip'):
+      python_fallback = True
 
     gs_folder = 'gs://%s/%s' % (self.bootstrap_bucket, self.basedir)
     gsutil = Gsutil(
         self.gsutil_exe, boto_path=os.devnull, bypass_prodaccess=True)
     # Get the most recent version of the zipfile.
     _, ls_out, _ = gsutil.check_call('ls', gs_folder)
     ls_out_sorted = sorted(ls_out.splitlines())
     if not ls_out_sorted:
       # This repo is not on Google Storage.
       return False
     latest_checkout = ls_out_sorted[-1]
 
     # Download zip file to a temporary directory.
     try:
       tempdir = tempfile.mkdtemp()
       self.print('Downloading %s' % latest_checkout)
       code, out, err = gsutil.check_call('cp', latest_checkout, tempdir)
       if code:
         self.print('%s\n%s' % (out, err))
         return False
       filename = os.path.join(tempdir, latest_checkout.split('/')[-1])
 
-      # Unpack the file with 7z on Windows, or unzip everywhere else.
-      if sys.platform.startswith('win'):
-        cmd = ['7z', 'x', '-o%s' % directory, '-tzip', filename]
+      # Unpack the file with 7z on Windows, unzip on linux, or fallback.
+      if not python_fallback:
+        if sys.platform.startswith('win'):
+          cmd = ['7z', 'x', '-o%s' % directory, '-tzip', filename]
+        else:
+          cmd = ['unzip', filename, '-d', directory]
+        retcode = subprocess.call(cmd)
       else:
-        cmd = ['unzip', filename, '-d', directory]
-      retcode = subprocess.call(cmd)
+        try:
+          with zipfile.ZipFile(filename, 'r') as f:
+            f.printdir()
+            f.extractall(directory)
+        except Exception as e:
+          self.print('Encountered error: %s' % str(e), file=sys.stderr)
+          retcode = 1
+        else:
+          retcode = 0
     finally:
       # Clean up the downloaded zipfile.
       gclient_utils.rmtree(tempdir)
 
     if retcode:
       self.print(
           'Extracting bootstrap zipfile %s failed.\n'
           'Resuming normal operations.' % filename)
       return False
     return True
@@ skipping 222 matching lines @@
     return options, args
 
 
 def main(argv):
   dispatcher = subcommand.CommandDispatcher(__name__)
   return dispatcher.execute(OptionParser(), argv)
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))