/usr/lib/python2.7/dist-packages/oslo_messaging/_drivers/zmq_driver/client/zmq_routing_table.py is in python-oslo.messaging 5.10.0-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 | # 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 logging
import retrying
import time
from oslo_messaging._drivers.zmq_driver.matchmaker import zmq_matchmaker_base
from oslo_messaging._drivers.zmq_driver import zmq_async
from oslo_messaging._drivers.zmq_driver import zmq_names
from oslo_messaging._i18n import _LW
zmq = zmq_async.import_zmq()
LOG = logging.getLogger(__name__)
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,
get_hosts=self.matchmaker.get_hosts_fanout,
get_hosts_retry=self.matchmaker.get_hosts_fanout_retry)
return self.routable_hosts.get(str(target), [])
def get_routable_host(self, target):
self._update_routing_table(
target,
get_hosts=self.matchmaker.get_hosts,
get_hosts_retry=self.matchmaker.get_hosts_retry)
hosts_for_target = self.routable_hosts.get(str(target))
if not hosts_for_target:
# Matchmaker doesn't contain any target
return None
host = hosts_for_target.pop(0)
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, get_hosts, get_hosts_retry):
routing_record = self.routing_table.get(str(target))
if routing_record is None:
self._fetch_hosts(target, get_hosts, get_hosts_retry)
self._renew_routable_hosts(target)
elif self._is_tm_expired(routing_record[1]):
self._fetch_hosts(target, get_hosts, get_hosts_retry)
def _fetch_hosts(self, target, get_hosts, get_hosts_retry):
key = str(target)
if key not in self.routing_table:
try:
self.routing_table[key] = (get_hosts_retry(
target, zmq_names.socket_type_str(zmq.DEALER)),
time.time())
except retrying.RetryError:
LOG.warning(_LW("Matchmaker contains no hosts for target %s")
% key)
else:
try:
hosts = get_hosts(
target, zmq_names.socket_type_str(zmq.DEALER))
self.routing_table[key] = (hosts, time.time())
except zmq_matchmaker_base.MatchmakerUnavailable:
LOG.warning(_LW("Matchmaker contains no hosts for target %s")
% key)
def _renew_routable_hosts(self, target):
key = str(target)
try:
hosts, _ = self.routing_table[key]
self.routable_hosts[key] = list(hosts)
except KeyError:
self.routable_hosts[key] = []
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