Docserver: Pull knowledge of host file systems into a single

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

-# Copyright 2013 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 caching_file_system import CachingFileSystem
-from local_file_system import LocalFileSystem
-from offline_file_system import OfflineFileSystem
-from subversion_file_system import SubversionFileSystem
-
-class HostFileSystemCreator(object):
-  '''Creates host file systems with configuration information. By default, SVN
-  file systems are created, although a constructor method can be passed in to
-  override this behavior (likely for testing purposes).
-  '''
-  def __init__(self,
-               object_store_creator,
-               offline=False,
-               constructor_for_test=None):
-    self._object_store_creator = object_store_creator
-    # Determines whether or not created file systems will be wrapped in an
-    # OfflineFileSystem.
-    self._offline = offline
-    # Provides custom create behavior, useful in tests.
-    self._constructor_for_test = constructor_for_test
-
-  def Create(self, branch='trunk', revision=None, offline=None):
-    '''Creates either SVN file systems or specialized file systems from the
-    constructor passed into this instance. Wraps the resulting file system in
-    an Offline file system if the offline flag is set, and finally wraps it in a
-    Caching file system.
-    '''
-    if self._constructor_for_test is not None:
-      file_system = self._constructor_for_test(branch=branch, revision=revision)
-    else:
-      file_system = SubversionFileSystem.Create(branch=branch,
-                                                revision=revision)
-    if offline or (offline is None and self._offline):
-      file_system = OfflineFileSystem(file_system)
-    return CachingFileSystem(file_system, self._object_store_creator)
-
-  @staticmethod
-  def ForLocal(object_store_creator):
-    '''Used in creating a server instance on localhost.
-    '''
-    return HostFileSystemCreator(
-        object_store_creator,
-        constructor_for_test=lambda **_: LocalFileSystem.Create())
-
-  @staticmethod
-  def ForTest(file_system, object_store_creator):
-    '''Used in creating a test server instance. The HostFileSystemCreator
-    returned here will always return |file_system| when its Create() method is
-    called.
-    '''
-    return HostFileSystemCreator(
-        object_store_creator,
-        constructor_for_test=lambda **_: file_system)