1 #!/usr/bin/python

     2 #

     3 # Copyright 2008 Google Inc.

     4 #

     5 # Licensed under the Apache License, Version 2.0 (the "License");

     6 # you may not use this file except in compliance with the License.

     7 # You may obtain a copy of the License at

     8 #

     9 #      http://www.apache.org/licenses/LICENSE-2.0

    10 #

    11 # Unless required by applicable law or agreed to in writing, software

    12 # distributed under the License is distributed on an "AS IS" BASIS,

    13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

    14 # See the License for the specific language governing permissions and

    15 # limitations under the License.

    16 

    17 """Convenience functions.

    18 """

    19 

    20 from google.appengine.api import datastore

    21 

    22 

    23 def transactional(operation):

    24   """Decorator that wraps a method in a datastore transaction.

    25 

    26   The method will be called through datastore.RunInTransaction, making the

    27   operation atomic.

    28   """

    29   def transactional_operation(*args, **kwargs):

    30     return datastore.RunInTransaction(operation, *args, **kwargs)

    31   return transactional_operation