app/soc/mapreduce/cache_list_items.py

# Copyright 2013 the Melange authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""Mapreduce to cache datastore entities for lists."""

import json
import pickle

from google.appengine.ext import ndb

from mapreduce import context


def mapProcess(entity):
  # TODO: (Aruna) Fix this import
  from melange.utils import lists

  ctx = context.get()
  params = ctx.mapreduce_spec.mapper.params

  list_id = params['list_id']
  col_funcs = [(c.col_id, c.getValue) for c in lists.getList(list_id).columns]
  query_pickle = params['query_pickle']

  query = pickle.loads(query_pickle)
  data_id = lists.getDataId(query)

  if query.filter('__key__', entity.key()).get():
    item = json.dumps(lists.toListItemDict(entity, col_funcs))

    yield (data_id, item)


def reduceProcess(data_id, entities):
  # TODO: (Aruna) Fix these import
  from melange.logic import cached_list
  from melange.utils import lists

  ctx = context.get()
  params = ctx.mapreduce_spec.mapper.params

  list_id = params['list_id']

  ndb.transaction(lambda: cached_list.setCacheItems(
      data_id, map(json.loads, entities), lists.getList(list_id).valid_period))