blob: ba566370fb668f8007ac04aef9837f8380e35875 [file] [log] [blame]
# Copyright 2009 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.
"""Module contains logic memcaching functions.
"""
from google.appengine.api import memcache
from google.appengine.ext import db
import soc.cache.base
def key(model, filter, order, *args, **kwargs):
"""Returns the memcache key for this query.
"""
new_filter = {}
for filter_key, value in filter.iteritems():
if isinstance(value, db.Model):
new_value = value.key().id_or_name()
else:
new_value = value
new_filter[filter_key] = new_value
return 'query_for_%(kind)s_%(filter)s_%(order)s' % {
'kind': repr(model.kind()),
'filter': repr(new_filter),
'order': repr(order),
}
def get(model, filter, order, *args, **kwargs):
"""Retrieves the data for the specified query from the memcache.
"""
memcache_key = key(model, filter, order)
# pylint: disable=E1101
return memcache.get(memcache_key), memcache_key
def add(data, memcache_key, *args, **kwargs):
"""Adds the data for the specified query in the memcache.
The data is added if and only if it is not already stored.
Args:
data: the data to be cached
"""
# Store data for fifteen minutes to force a refresh every so often
retention = 15*60
# pylint: disable=E1101
memcache.add(memcache_key, data, retention)
def set(data, memcache_key):
"""Sets the data for the specified query in the memcache.
The data is always added to memcache.
Args:
data: the data to be cached
"""
# Store data for fifteen minutes to force a refresh every so often
retention = 15*60
# pylint: disable=E1101
memcache.set(memcache_key, data, retention)
def flush(model, filter):
"""Removes the data for the current user from the memcache.
"""
memcache_key = key(model, filter)
# pylint: disable=E1101
memcache.delete(memcache_key)
# define the cache functions
cache = soc.cache.base.getSoftCacher(get, add)
force_cache = soc.cache.base.getHardCacher(key, set)