Add a platform filtering and executable setting abilities to download_from_google_storage.

download_from_google_storage.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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.
 
 """Download files from Google Storage based on SHA1 sums."""
 
 
 import hashlib
 import optparse
 import os
 import Queue
 import re
+import stat
 import sys
 import threading
 import time
 
 import subprocess2
 
 
 GSUTIL_DEFAULT_PATH = os.path.join(
     os.path.dirname(os.path.abspath(__file__)),
     'third_party', 'gsutil', 'gsutil')
@@ skipping 154 matching lines @@
           file_url, output_filename)))
       continue
     # Fetch the file.
     out_q.put('%d> Downloading %s...' % (
         thread_num, output_filename))
     code, _, err = gsutil.check_call('cp', '-q', file_url, output_filename)
     if code != 0:
       out_q.put('%d> %s' % (thread_num, err))
       ret_codes.put((code, err))
 
+    # Mark executable if necessary. We key off of the custom header
+    # "x-goog-meta-executable".
+    #
+    # TODO(hinoka): It is supposedly faster to use "gsutil stat" but that
+    # doesn't appear to be supported by the gsutil currently in our tree. When
+    # we update, this code should use that instead of "gsutil ls -L".
+    if not sys.platform.startswith('win'):
+      code, out, _ = gsutil.check_call('ls', '-L', file_url)
+      if code != 0:
+        out_q.put('%d> %s' % (thread_num, err))
+        ret_codes.put((code, err))
+      elif re.search('x-goog-meta-executable:', out):
+        st = os.stat(output_filename)
+        os.chmod(output_filename, st.st_mode | stat.S_IEXEC)
 
 def printer_worker(output_queue):
   while True:
     line = output_queue.get()
     # Its plausible we want to print empty lines.
     if line is None:
       break
     print line
 
 
@@ skipping 77 matching lines @@
   parser.add_option('-d', '--directory', action='store_true',
                     help='The target is a directory.  '
                          'Cannot be used with -s/--sha1_file.')
   parser.add_option('-s', '--sha1_file', action='store_true',
                     help='The target is a file containing a sha1 sum.  '
                          'Cannot be used with -d/--directory.')
   parser.add_option('-g', '--config', action='store_true',
                     help='Alias for "gsutil config".  Run this if you want '
                          'to initialize your saved Google Storage '
                          'credentials.')
+  parser.add_option('-p', '--platform', 
+                    help='A regular expression that is compared against '
+                         'Python\'s sys.platform. If this option is specified, '
+                         'the download will happen only if there is a match.')
 
   (options, args) = parser.parse_args()
-  # First, make sure we can find a working instance of gsutil.
+
+  # Make sure we should run at all based on platform matching.
+  if options.platform:
+    if not re.match(options.platform, sys.platform):
+      print('The current platform doesn\'t match "%s", skipping.' %
+            options.platform)
+      return 0
+
+  # Make sure we can find a working instance of gsutil.
   if os.path.exists(GSUTIL_DEFAULT_PATH):
     gsutil = Gsutil(GSUTIL_DEFAULT_PATH, boto_path=options.boto)
   else:
     gsutil = None
     for path in os.environ["PATH"].split(os.pathsep):
       if os.path.exists(path) and 'gsutil' in os.listdir(path):
         gsutil = Gsutil(os.path.join(path, 'gsutil'), boto_path=options.boto)
     if not gsutil:
       parser.error('gsutil not found in %s, bad depot_tools checkout?' %
                   GSUTIL_DEFAULT_PATH)
@@ skipping 45 matching lines @@
     return code
 
   return download_from_google_storage(
       input_filename, base_url, gsutil, options.num_threads, options.directory,
       options.recursive, options.force, options.output, options.ignore_errors,
       options.sha1_file)
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv))