Add retries to file operations for Windows.

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
@@ skipping 163 matching lines @@
     self.url = url
     self.fetch_specs = set([self.parse_fetch_spec(ref) for ref in (refs or [])])
     self.basedir = self.UrlToCacheDir(url)
     self.mirror_path = os.path.join(self.GetCachePath(), self.basedir)
     if print_func:
       self.print = self.print_without_file
       self.print_func = print_func
     else:
       self.print = print
 
-  def print_without_file(self, message, **kwargs):
+  def print_without_file(self, message, **_kwargs):
     self.print_func(message)
 
   @property
   def bootstrap_bucket(self):
     if 'chrome-internal' in self.url:
       return 'chrome-git-cache'
     else:
       return 'chromium-git-cache'
 
   @classmethod
@@ skipping 28 matching lines @@
           cachepath = subprocess.check_output(
               [cls.git_exe, 'config', '--global', 'cache.cachepath']).strip()
         except subprocess.CalledProcessError:
           cachepath = None
         if not cachepath:
           raise RuntimeError(
               'No global cache.cachepath git configuration found.')
         setattr(cls, 'cachepath', cachepath)
       return getattr(cls, 'cachepath')
 
+  def Rename(self, src, dst, count=3):
+    sleep_time = 1

[nodir, 2016/11/11 01:53:59]

Strange indentation 

+    while True:
+      try:
+        os.rename(src, dst)
+        return
+      except OSError as e:
+        # This is somehow racy on Windows.
+        # Catching OSError because WindowsError isn't portable and
+        # pylint complains.
+        if not count:
+          raise
+
+        self.print('Error moving [%s] to [%s] (%d retries remaining): %s' % (
+            src, dst, count, str(e)))

[nodir, 2016/11/11 01:53:59]

str unnecessary?

+        time.sleep(sleep_time)
+        count -= 1
+        sleep_time *= 2
+
+
   def RunGit(self, cmd, **kwargs):
     """Run git in a subprocess."""
     cwd = kwargs.setdefault('cwd', self.mirror_path)
     kwargs.setdefault('print_stdout', False)
     kwargs.setdefault('filter_fn', self.print)
     env = kwargs.get('env') or kwargs.setdefault('env', os.environ.copy())
     env.setdefault('GIT_ASKPASS', 'true')
     env.setdefault('SSH_ASKPASS', 'true')
     self.print('running "git %s" in "%s"' % (' '.join(cmd), cwd))
     gclient_utils.CheckCallAndFilter([self.git_exe] + cmd, **kwargs)
@@ skipping 74 matching lines @@
           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.rm_file_or_tree(tempdir)

[nodir, 2016/11/11 01:53:59]

Retry here please

 
     if retcode:
       self.print(
           'Extracting bootstrap zipfile %s failed.\n'
           'Resuming normal operations.' % filename)
       return False
     return True
 
   def exists(self):
     return os.path.isfile(os.path.join(self.mirror_path, 'config'))
@@ skipping 96 matching lines @@
       # This is a major failure, we need to clean and force a bootstrap.
       gclient_utils.rmtree(rundir)
       self.print(GIT_CACHE_CORRUPT_MESSAGE)
       tempdir = self._ensure_bootstrapped(depth, bootstrap, force=True)
       assert tempdir
       self._fetch(tempdir or self.mirror_path, verbose, depth)
     finally:
       if tempdir:
         if os.path.exists(self.mirror_path):
           gclient_utils.rmtree(self.mirror_path)
-        os.rename(tempdir, self.mirror_path)
+        self.Rename(tempdir, self.mirror_path)
       if not ignore_lock:
         lockfile.unlock()
 
   def update_bootstrap(self, prune=False):
     # The files are named <git number>.zip
     gen_number = subprocess.check_output(
         [self.git_exe, 'number', 'master'], cwd=self.mirror_path).strip()
     # Run Garbage Collect to compress packfile.
     self.RunGit(['gc', '--prune=all'])
     # Creating a temp file and then deleting it ensures we can use this name.
@@ skipping 267 matching lines @@
   dispatcher = subcommand.CommandDispatcher(__name__)
   return dispatcher.execute(OptionParser(), argv)
 
 
 if __name__ == '__main__':
   try:
     sys.exit(main(sys.argv[1:]))
   except KeyboardInterrupt:
     sys.stderr.write('interrupted\n')
     sys.exit(1)