[Findit] Re-org code.

appengine/findit/model/versioned_config.py

-# Copyright 2015 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.
-
-"""Versioned singleton entity with the global configuration."""
-
-import logging
-
-from google.appengine.ext import ndb
-
-from model.versioned_model import VersionedModel
-
-
-class VersionedConfig(VersionedModel):
-  """Singleton entity with the global configuration of the service.
-
-  All changes are stored in the revision log.
-  """
-
-  # When this revision of configuration was created.
-  updated_ts = ndb.DateTimeProperty(indexed=False, auto_now=True)
-
-  # Who created this revision of configuration.
-  updated_by = ndb.StringProperty(indexed=False)
-
-  @classmethod
-  def Get(cls, version=None):
-    """Returns the version of the config entity, the latest if not specified."""
-    config_data = cls.GetVersion(version=version)
-    return config_data or cls() if version is None else config_data
-
-  def Update(self, user, is_admin, **kwargs):
-    """Apply ``kwargs`` dict to the entity and stores the entity if changed."""
-    if not is_admin:
-      raise Exception('Only admin could update config.')
-
-    dirty = False
-    for k, v in kwargs.iteritems():
-      assert k in self._properties, k
-      if getattr(self, k) != v:
-        setattr(self, k, v)
-        dirty = True
-
-    if dirty:
-      user_name = user.email().split('@')[0]
-      self.updated_by = user_name
-      self.Save()
-      logging.info('Config %s was updated by %s', self.__class__, user_name)
-
-    return dirty