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−#!/usr/bin/python
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−#
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−# Copyright 2008 Google Inc.
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−#
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−# Licensed under the Apache License, Version 2.0 (the "License");
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−# you may not use this file except in compliance with the License.
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−# You may obtain a copy of the License at
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−#
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−#      http://www.apache.org/licenses/LICENSE-2.0
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−#
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−# Unless required by applicable law or agreed to in writing, software
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−# distributed under the License is distributed on an "AS IS" BASIS,
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−# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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−# See the License for the specific language governing permissions and
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−# limitations under the License.
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−
+
−"""Convenience functions.
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−"""
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−
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−from google.appengine.api import datastore
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−
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−
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−def transactional(operation):
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−  """Decorator that wraps a method in a datastore transaction.
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−
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−  The method will be called through datastore.RunInTransaction, making the
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−  operation atomic.
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−  """
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−  def transactional_operation(*args, **kwargs):
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−    return datastore.RunInTransaction(operation, *args, **kwargs)
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−  return transactional_operation