Source code for keystone.common.cache.core
# Copyright 2013 Metacloud
#
# 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.
"""Keystone Caching Layer Implementation."""
import dogpile.cache
from dogpile.cache import api
from oslo_cache import core as cache
from keystone.common.cache import _context_cache
import keystone.conf
CONF = keystone.conf.CONF
CACHE_REGION = cache.create_region()
register_model_handler = _context_cache._register_model_handler
[docs]def get_memoization_decorator(group, expiration_group=None, region=None):
if region is None:
region = CACHE_REGION
return cache.get_memoization_decorator(CONF, region, group,
expiration_group=expiration_group)
# NOTE(stevemar): When memcache_pool, mongo and noop backends are removed
# we no longer need to register the backends here.
dogpile.cache.register_backend(
'keystone.common.cache.noop',
'keystone.common.cache.backends.noop',
'NoopCacheBackend')
dogpile.cache.register_backend(
'keystone.cache.mongo',
'keystone.common.cache.backends.mongo',
'MongoCacheBackend')
dogpile.cache.register_backend(
'keystone.cache.memcache_pool',
'keystone.common.cache.backends.memcache_pool',
'PooledMemcachedBackend')
# TODO(morganfainberg): Move this logic up into oslo.cache directly
# so we can handle region-wide invalidations or alternatively propose
# a fix to dogpile.cache to make region-wide invalidates possible to
# work across distributed processes.
class _RegionInvalidator(object):
def __init__(self, region, region_name):
self.region = region
self.region_name = region_name
region_key = '_RegionExpiration.%(type)s.%(region_name)s'
self.soft_region_key = region_key % {'type': 'soft',
'region_name': self.region_name}
self.hard_region_key = region_key % {'type': 'hard',
'region_name': self.region_name}
@property
def hard_invalidated(self):
invalidated = self.region.backend.get(self.hard_region_key)
if invalidated is not api.NO_VALUE:
return invalidated.payload
return None
@hard_invalidated.setter
def hard_invalidated(self, value):
self.region.set(self.hard_region_key, value)
@hard_invalidated.deleter
def hard_invalidated(self):
self.region.delete(self.hard_region_key)
@property
def soft_invalidated(self):
invalidated = self.region.backend.get(self.soft_region_key)
if invalidated is not api.NO_VALUE:
return invalidated.payload
return None
@soft_invalidated.setter
def soft_invalidated(self, value):
self.region.set(self.soft_region_key, value)
@soft_invalidated.deleter
def soft_invalidated(self):
self.region.delete(self.soft_region_key)
[docs]def apply_invalidation_patch(region, region_name):
"""Patch the region interfaces to ensure we share the expiration time.
This method is used to patch region.invalidate, region._hard_invalidated,
and region._soft_invalidated.
"""
# Patch the region object. This logic needs to be moved up into dogpile
# itself. Patching the internal interfaces, unfortunately, is the only
# way to handle this at the moment.
invalidator = _RegionInvalidator(region=region, region_name=region_name)
setattr(region, '_hard_invalidated', invalidator.hard_invalidated)
setattr(region, '_soft_invalidated', invalidator.soft_invalidated)