make version of ts_mon compatible with appengine

appengine/chromium_build_logs/third_party/oauth2client/file.py

-# Copyright (C) 2010 Google Inc.
+# Copyright 2014 Google Inc. All rights reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #      http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
 """Utilities for OAuth.
 
 Utilities for making it easier to work with OAuth 2.0
 credentials.
 """
 
 __author__ = 'jcgregorio@google.com (Joe Gregorio)'
 
 import os
-import stat
 import threading
 
-from anyjson import simplejson
-from client import Storage as BaseStorage
-from client import Credentials
+from oauth2client.client import Credentials
+from oauth2client.client import Storage as BaseStorage
+
+
+class CredentialsFileSymbolicLinkError(Exception):
+  """Credentials files must not be symbolic links."""
 
 
 class Storage(BaseStorage):
   """Store and retrieve a single credential to and from a file."""
 
   def __init__(self, filename):
     self._filename = filename
     self._lock = threading.Lock()
 
+  def _validate_file(self):
+    if os.path.islink(self._filename):
+      raise CredentialsFileSymbolicLinkError(
+          'File: %s is a symbolic link.' % self._filename)
+
   def acquire_lock(self):
     """Acquires any lock necessary to access this Storage.
 
     This lock is not reentrant."""
     self._lock.acquire()
 
   def release_lock(self):
     """Release the Storage lock.
 
     Trying to release a lock that isn't held will result in a
     RuntimeError.
     """
     self._lock.release()
 
   def locked_get(self):
     """Retrieve Credential from file.
 
     Returns:
       oauth2client.client.Credentials
+
+    Raises:
+      CredentialsFileSymbolicLinkError if the file is a symbolic link.
     """
     credentials = None
+    self._validate_file()
     try:
       f = open(self._filename, 'rb')
       content = f.read()
       f.close()
     except IOError:
       return credentials
 
     try:
       credentials = Credentials.new_from_json(content)
       credentials.set_store(self)
     except ValueError:
       pass
 
     return credentials
 
   def _create_file_if_needed(self):
     """Create an empty file if necessary.
 
     This method will not initialize the file. Instead it implements a
     simple version of "touch" to ensure the file has been created.
     """
     if not os.path.exists(self._filename):
-      old_umask = os.umask(0177)
+      old_umask = os.umask(0o177)
       try:
         open(self._filename, 'a+b').close()
       finally:
         os.umask(old_umask)
 
-
   def locked_put(self, credentials):
     """Write Credentials to file.
 
     Args:
       credentials: Credentials, the credentials to store.
+
+    Raises:
+      CredentialsFileSymbolicLinkError if the file is a symbolic link.
     """
 
     self._create_file_if_needed()
-    f = open(self._filename, 'wb')
+    self._validate_file()
+    f = open(self._filename, 'w')
     f.write(credentials.to_json())
     f.close()
+
+  def locked_delete(self):
+    """Delete Credentials file.
+
+    Args:
+      credentials: Credentials, the credentials to store.
+    """
+
+    os.unlink(self._filename)