Docserver: Further refactoring to the new GithubFileSystem to make it update

chrome/common/extensions/docs/server2/file_system.py

 # 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.
 
 from future import Gettable, Future
 
 
-class FileNotFoundError(Exception):
+class _BaseFileSystemException(Exception):
+  def __init__(self, message):
+    Exception.__init__(self, message)
+
+  @classmethod
+  def RaiseInFuture(cls, message):
+    def boom(): raise cls(message)
+    return Future(delegate=Gettable(boom))
+
+
+class FileNotFoundError(_BaseFileSystemException):
   '''Raised when a file isn't found for read or stat.
   '''
   def __init__(self, filename):
-    Exception.__init__(self, filename)
+    _BaseFileSystemException.__init__(self, filename)
 
 
-class FileSystemError(Exception):
+class FileSystemError(_BaseFileSystemException):
   '''Raised on when there are errors reading or statting files, such as a
   network timeout.
   '''
   def __init__(self, filename):
-    Exception.__init__(self, filename)
+    _BaseFileSystemException.__init__(self, filename)
 
 
 class StatInfo(object):
   '''The result of calling Stat on a FileSystem.
   '''
   def __init__(self, version, child_versions=None):
     self.version = version
     self.child_versions = child_versions
 
   def __eq__(self, other):
@@ skipping 102 matching lines @@
           yield walkinfo
 
     for walkinfo in walk(root):
       yield walkinfo
 
   def __repr__(self):
     return '<%s>' % type(self).__name__
 
   def __str__(self):
     return repr(self)