oslo.cache/oslo_cache/backends/etcd3gw.py

74 lines
2.3 KiB
Python

# Copyright 2015 Mirantis Inc
#
# 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.
"""dogpile.cache backend that uses etcd 3.x for storage"""
from dogpile.cache import api
import etcd3gw
from oslo_cache import core
from oslo_serialization import jsonutils
__all__ = [
'Etcd3gwCacheBackend'
]
_NO_VALUE = core.NO_VALUE
class Etcd3gwCacheBackend(api.CacheBackend):
#: Default socket/lock/member/leader timeout used when none is provided.
DEFAULT_TIMEOUT = 30
#: Default hostname used when none is provided.
DEFAULT_HOST = "localhost"
#: Default port used if none provided (4001 or 2379 are the common ones).
DEFAULT_PORT = 2379
def __init__(self, arguments):
self.host = arguments.get('host', self.DEFAULT_HOST)
self.port = arguments.get('port', self.DEFAULT_PORT)
self.timeout = int(arguments.get('timeout', self.DEFAULT_TIMEOUT))
self._client = etcd3gw.client(host=self.host,
port=self.port,
timeout=self.timeout)
def get(self, key):
values = self._client.get(key, False)
if not values:
return core.NO_VALUE
value, metadata = jsonutils.loads(values[0])
return api.CachedValue(value, metadata)
def get_multi(self, keys):
"""Retrieves the value for a list of keys."""
return [self.get(key) for key in keys]
def set(self, key, value):
self.set_multi({key: value})
def set_multi(self, mapping):
lease = None
if self.timeout:
lease = self._client.lease(ttl=self.timeout)
for key, value in mapping.items():
self._client.put(key, jsonutils.dumps(value), lease)
def delete(self, key):
self._client.delete(key)
def delete_multi(self, keys):
for key in keys:
self._client.delete(key)