old_contents: # 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.
  
  import datetime
  
  from oslo.utils import timeutils
  
  from keystone.common import kvs
  from keystone import config
  from keystone.contrib import revoke
  from keystone import exception
  
  
  CONF = config.CONF
  
  _EVENT_KEY = 'os-revoke-events'
  _KVS_BACKEND = 'openstack.kvs.Memory'
  
  
  class Revoke(revoke.Driver):
      def __init__(self, **kwargs):
          super(Revoke, self).__init__()
          self._store = kvs.get_key_value_store('os-revoke-driver')
          self._store.configure(backing_store=_KVS_BACKEND, **kwargs)
  
      def _get_event(self):
          try:
              return self._store.get(_EVENT_KEY)
          except exception.NotFound:
              return []
  
      def _prune_expired_events_and_get(self, last_fetch=None, new_event=None):
          pruned = []
          results = []
          expire_delta = datetime.timedelta(seconds=CONF.token.expiration)
          oldest = timeutils.utcnow() - expire_delta
          # TODO(ayoung): Store the time of the oldest event so that the
          # prune process can be skipped if none of the events have timed out.
          with self._store.get_lock(_EVENT_KEY) as lock:
              events = self._get_event()
              if new_event is not None:
                  events.append(new_event)
  
              for event in events:
                  revoked_at = event.revoked_at
                  if revoked_at > oldest:
                      pruned.append(event)
                      if last_fetch is None or revoked_at > last_fetch:
                          results.append(event)
              self._store.set(_EVENT_KEY, pruned, lock)
          return results
  
      def get_events(self, last_fetch=None):
          return self._prune_expired_events_and_get(last_fetch=last_fetch)
  
      def revoke(self, event):
          self._prune_expired_events_and_get(new_event=event)
  
new_contents: # 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.
  
  import datetime
  
  from oslo.utils import timeutils
  
  from keystone.common import kvs
  from keystone import config
  from keystone.contrib import revoke
  from keystone import exception
  from keystone.openstack.common import versionutils
  
  
  CONF = config.CONF
  
  _EVENT_KEY = 'os-revoke-events'
  _KVS_BACKEND = 'openstack.kvs.Memory'
  
  
  class Revoke(revoke.Driver):
  
      @versionutils.deprecated(
          versionutils.deprecated.JUNO,
          in_favor_of='keystone.contrib.revoke.backends.sql',
          remove_in=+1,
          what='keystone.contrib.revoke.backends.kvs')
      def __init__(self, **kwargs):
          super(Revoke, self).__init__()
          self._store = kvs.get_key_value_store('os-revoke-driver')
          self._store.configure(backing_store=_KVS_BACKEND, **kwargs)
  
      def _get_event(self):
          try:
              return self._store.get(_EVENT_KEY)
          except exception.NotFound:
              return []
  
      def _prune_expired_events_and_get(self, last_fetch=None, new_event=None):
          pruned = []
          results = []
          expire_delta = datetime.timedelta(seconds=CONF.token.expiration)
          oldest = timeutils.utcnow() - expire_delta
          # TODO(ayoung): Store the time of the oldest event so that the
          # prune process can be skipped if none of the events have timed out.
          with self._store.get_lock(_EVENT_KEY) as lock:
              events = self._get_event()
              if new_event is not None:
                  events.append(new_event)
  
              for event in events:
                  revoked_at = event.revoked_at
                  if revoked_at > oldest:
                      pruned.append(event)
                      if last_fetch is None or revoked_at > last_fetch:
                          results.append(event)
              self._store.set(_EVENT_KEY, pruned, lock)
          return results
  
      def get_events(self, last_fetch=None):
          return self._prune_expired_events_and_get(last_fetch=last_fetch)
  
      def revoke(self, event):
          self._prune_expired_events_and_get(new_event=event)
  
subject: Mark the revoke kvs backend deprecated, for removal in Kilo