67 lines
2.4 KiB
Python
67 lines
2.4 KiB
Python
# Copyright 2016 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.
|
|
|
|
import time
|
|
|
|
from oslo_messaging._drivers.zmq_driver import zmq_async
|
|
from oslo_messaging._drivers.zmq_driver import zmq_names
|
|
|
|
zmq = zmq_async.import_zmq()
|
|
|
|
|
|
class RoutingTable(object):
|
|
"""This class implements local routing-table cache
|
|
taken from matchmaker. Its purpose is to give the next routable
|
|
host id (remote DEALER's id) by request for specific target in
|
|
round-robin fashion.
|
|
"""
|
|
|
|
def __init__(self, conf, matchmaker):
|
|
self.conf = conf
|
|
self.matchmaker = matchmaker
|
|
self.routing_table = {}
|
|
self.routable_hosts = {}
|
|
|
|
def get_all_hosts(self, target):
|
|
self._update_routing_table(target)
|
|
return list(self.routable_hosts.get(str(target), []))
|
|
|
|
def get_routable_host(self, target):
|
|
self._update_routing_table(target)
|
|
hosts_for_target = self.routable_hosts[str(target)]
|
|
host = hosts_for_target.pop()
|
|
if not hosts_for_target:
|
|
self._renew_routable_hosts(target)
|
|
return host
|
|
|
|
def _is_tm_expired(self, tm):
|
|
return 0 <= self.conf.oslo_messaging_zmq.zmq_target_expire \
|
|
<= time.time() - tm
|
|
|
|
def _update_routing_table(self, target):
|
|
routing_record = self.routing_table.get(str(target))
|
|
if routing_record is None:
|
|
self._fetch_hosts(target)
|
|
self._renew_routable_hosts(target)
|
|
elif self._is_tm_expired(routing_record[1]):
|
|
self._fetch_hosts(target)
|
|
|
|
def _fetch_hosts(self, target):
|
|
self.routing_table[str(target)] = (self.matchmaker.get_hosts(
|
|
target, zmq_names.socket_type_str(zmq.DEALER)), time.time())
|
|
|
|
def _renew_routable_hosts(self, target):
|
|
hosts, _ = self.routing_table[str(target)]
|
|
self.routable_hosts[str(target)] = list(hosts)
|