410 lines
14 KiB
Python
410 lines
14 KiB
Python
|
|
# Copyright 2013 Red Hat, 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.
|
|
|
|
__all__ = ['AMQPDriverBase']
|
|
|
|
import logging
|
|
import Queue
|
|
import threading
|
|
import uuid
|
|
|
|
from oslo import messaging
|
|
from oslo.messaging._drivers import amqp as rpc_amqp
|
|
from oslo.messaging._drivers import base
|
|
from oslo.messaging._drivers import common as rpc_common
|
|
|
|
LOG = logging.getLogger(__name__)
|
|
|
|
|
|
class AMQPIncomingMessage(base.IncomingMessage):
|
|
|
|
def __init__(self, listener, ctxt, message, msg_id, reply_q):
|
|
super(AMQPIncomingMessage, self).__init__(listener, ctxt, message)
|
|
|
|
self.msg_id = msg_id
|
|
self.reply_q = reply_q
|
|
|
|
def _send_reply(self, conn, reply=None, failure=None,
|
|
ending=False, log_failure=True):
|
|
if failure:
|
|
failure = rpc_common.serialize_remote_exception(failure,
|
|
log_failure)
|
|
|
|
msg = {'result': reply, 'failure': failure}
|
|
if ending:
|
|
msg['ending'] = True
|
|
|
|
rpc_amqp._add_unique_id(msg)
|
|
|
|
# If a reply_q exists, add the msg_id to the reply and pass the
|
|
# reply_q to direct_send() to use it as the response queue.
|
|
# Otherwise use the msg_id for backward compatibility.
|
|
if self.reply_q:
|
|
msg['_msg_id'] = self.msg_id
|
|
conn.direct_send(self.reply_q, rpc_common.serialize_msg(msg))
|
|
else:
|
|
conn.direct_send(self.msg_id, rpc_common.serialize_msg(msg))
|
|
|
|
def reply(self, reply=None, failure=None, log_failure=True):
|
|
with self.listener.driver._get_connection() as conn:
|
|
self._send_reply(conn, reply, failure, log_failure=log_failure)
|
|
self._send_reply(conn, ending=True)
|
|
|
|
|
|
class AMQPListener(base.Listener):
|
|
|
|
def __init__(self, driver, target, conn):
|
|
super(AMQPListener, self).__init__(driver, target)
|
|
self.conn = conn
|
|
self.msg_id_cache = rpc_amqp._MsgIdCache()
|
|
self.incoming = []
|
|
|
|
def __call__(self, message):
|
|
# FIXME(markmc): logging isn't driver specific
|
|
rpc_common._safe_log(LOG.debug, 'received %s', message)
|
|
|
|
self.msg_id_cache.check_duplicate_message(message)
|
|
ctxt = rpc_amqp.unpack_context(self.conf, message)
|
|
|
|
self.incoming.append(AMQPIncomingMessage(self,
|
|
ctxt.to_dict(),
|
|
message,
|
|
ctxt.msg_id,
|
|
ctxt.reply_q))
|
|
|
|
def poll(self):
|
|
while True:
|
|
if self.incoming:
|
|
return self.incoming.pop(0)
|
|
self.conn.consume(limit=1)
|
|
|
|
|
|
class ReplyWaiters(object):
|
|
|
|
WAKE_UP = object()
|
|
|
|
def __init__(self):
|
|
self._queues = {}
|
|
self._wrn_threshold = 10
|
|
|
|
def get(self, msg_id, timeout):
|
|
try:
|
|
return self._queues[msg_id].get(block=True, timeout=timeout)
|
|
except Queue.Empty:
|
|
raise messaging.MessagingTimeout('Timed out waiting for a reply '
|
|
'to message ID %s' % msg_id)
|
|
|
|
def check(self, msg_id):
|
|
try:
|
|
return self._queues[msg_id].get(block=False)
|
|
except Queue.Empty:
|
|
return None
|
|
|
|
def put(self, msg_id, message_data):
|
|
queue = self._queues.get(msg_id)
|
|
if not queue:
|
|
LOG.warn('No calling threads waiting for msg_id : %(msg_id)s'
|
|
', message : %(data)s', {'msg_id': msg_id,
|
|
'data': message_data})
|
|
LOG.warn('_queues: %s' % str(self._queues))
|
|
else:
|
|
queue.put(message_data)
|
|
|
|
def wake_all(self, except_id):
|
|
msg_ids = [i for i in self._queues.keys() if i != except_id]
|
|
for msg_id in msg_ids:
|
|
self.put(msg_id, self.WAKE_UP)
|
|
|
|
def add(self, msg_id, queue):
|
|
self._queues[msg_id] = queue
|
|
if len(self._queues) > self._wrn_threshold:
|
|
LOG.warn('Number of call queues is greater than warning '
|
|
'threshold: %d. There could be a leak.' %
|
|
self._wrn_threshold)
|
|
self._wrn_threshold *= 2
|
|
|
|
def remove(self, msg_id):
|
|
del self._queues[msg_id]
|
|
|
|
|
|
class ReplyWaiter(object):
|
|
|
|
def __init__(self, conf, reply_q, conn, allowed_remote_exmods):
|
|
self.conf = conf
|
|
self.conn = conn
|
|
self.reply_q = reply_q
|
|
self.allowed_remote_exmods = allowed_remote_exmods
|
|
|
|
self.conn_lock = threading.Lock()
|
|
self.incoming = []
|
|
self.msg_id_cache = rpc_amqp._MsgIdCache()
|
|
self.waiters = ReplyWaiters()
|
|
|
|
conn.declare_direct_consumer(reply_q, self)
|
|
|
|
def __call__(self, message):
|
|
self.incoming.append(message)
|
|
|
|
def listen(self, msg_id):
|
|
queue = Queue.Queue()
|
|
self.waiters.add(msg_id, queue)
|
|
|
|
def unlisten(self, msg_id):
|
|
self.waiters.remove(msg_id)
|
|
|
|
def _process_reply(self, data):
|
|
result = None
|
|
ending = False
|
|
self.msg_id_cache.check_duplicate_message(data)
|
|
if data['failure']:
|
|
failure = data['failure']
|
|
result = rpc_common.deserialize_remote_exception(
|
|
failure, self.allowed_remote_exmods)
|
|
elif data.get('ending', False):
|
|
ending = True
|
|
else:
|
|
result = data['result']
|
|
return result, ending
|
|
|
|
def _poll_connection(self, msg_id, timeout):
|
|
while True:
|
|
while self.incoming:
|
|
message_data = self.incoming.pop(0)
|
|
|
|
incoming_msg_id = message_data.pop('_msg_id', None)
|
|
if incoming_msg_id == msg_id:
|
|
return self._process_reply(message_data)
|
|
|
|
self.waiters.put(incoming_msg_id, message_data)
|
|
|
|
try:
|
|
self.conn.consume(limit=1, timeout=timeout)
|
|
except rpc_common.Timeout:
|
|
raise messaging.MessagingTimeout('Timed out waiting for a '
|
|
'reply to message ID %s'
|
|
% msg_id)
|
|
|
|
def _poll_queue(self, msg_id, timeout):
|
|
message = self.waiters.get(msg_id, timeout)
|
|
if message is self.waiters.WAKE_UP:
|
|
return None, None, True # lock was released
|
|
|
|
reply, ending = self._process_reply(message)
|
|
return reply, ending, False
|
|
|
|
def _check_queue(self, msg_id):
|
|
while True:
|
|
message = self.waiters.check(msg_id)
|
|
if message is self.waiters.WAKE_UP:
|
|
continue
|
|
if message is None:
|
|
return None, None, True # queue is empty
|
|
|
|
reply, ending = self._process_reply(message)
|
|
return reply, ending, False
|
|
|
|
def wait(self, msg_id, timeout):
|
|
#
|
|
# NOTE(markmc): we're waiting for a reply for msg_id to come in for on
|
|
# the reply_q, but there may be other threads also waiting for replies
|
|
# to other msg_ids
|
|
#
|
|
# Only one thread can be consuming from the queue using this connection
|
|
# and we don't want to hold open a connection per thread, so instead we
|
|
# have the first thread take responsibility for passing replies not
|
|
# intended for itself to the appropriate thread.
|
|
#
|
|
final_reply = None
|
|
while True:
|
|
if self.conn_lock.acquire(False):
|
|
# Ok, we're the thread responsible for polling the connection
|
|
try:
|
|
# Check the queue to see if a previous lock-holding thread
|
|
# queued up a reply already
|
|
while True:
|
|
reply, ending, empty = self._check_queue(msg_id)
|
|
if empty:
|
|
break
|
|
if not ending:
|
|
final_reply = reply
|
|
else:
|
|
return final_reply
|
|
|
|
# Now actually poll the connection
|
|
while True:
|
|
reply, ending = self._poll_connection(msg_id, timeout)
|
|
if not ending:
|
|
final_reply = reply
|
|
else:
|
|
return final_reply
|
|
finally:
|
|
self.conn_lock.release()
|
|
# We've got our reply, tell the other threads to wake up
|
|
# so that one of them will take over the responsibility for
|
|
# polling the connection
|
|
self.waiters.wake_all(msg_id)
|
|
else:
|
|
# We're going to wait for the first thread to pass us our reply
|
|
reply, ending, trylock = self._poll_queue(msg_id, timeout)
|
|
if trylock:
|
|
# The first thread got its reply, let's try and take over
|
|
# the responsibility for polling
|
|
continue
|
|
if not ending:
|
|
final_reply = reply
|
|
else:
|
|
return final_reply
|
|
|
|
|
|
class AMQPDriverBase(base.BaseDriver):
|
|
|
|
def __init__(self, conf, url, connection_pool,
|
|
default_exchange=None, allowed_remote_exmods=[]):
|
|
super(AMQPDriverBase, self).__init__(conf, url, default_exchange,
|
|
allowed_remote_exmods)
|
|
|
|
self._server_params = self._server_params_from_url(self._url)
|
|
|
|
self._default_exchange = default_exchange
|
|
|
|
# FIXME(markmc): temp hack
|
|
if self._default_exchange:
|
|
self.conf.set_override('control_exchange', self._default_exchange)
|
|
|
|
self._connection_pool = connection_pool
|
|
|
|
self._reply_q_lock = threading.Lock()
|
|
self._reply_q = None
|
|
self._reply_q_conn = None
|
|
self._waiter = None
|
|
|
|
def _server_params_from_url(self, url):
|
|
sp = {}
|
|
|
|
if url.virtual_host is not None:
|
|
sp['virtual_host'] = url.virtual_host
|
|
|
|
if url.hosts:
|
|
# FIXME(markmc): support multiple hosts
|
|
host = url.hosts[0]
|
|
|
|
sp['hostname'] = host.hostname
|
|
if host.port is not None:
|
|
sp['port'] = host.port
|
|
sp['username'] = host.username or ''
|
|
sp['password'] = host.password or ''
|
|
|
|
return sp
|
|
|
|
def _get_connection(self, pooled=True):
|
|
# FIXME(markmc): we don't yet have a connection pool for each
|
|
# Transport instance, so we'll only use the pool with the
|
|
# transport configuration from the config file
|
|
server_params = self._server_params or None
|
|
if server_params:
|
|
pooled = False
|
|
return rpc_amqp.ConnectionContext(self.conf,
|
|
self._connection_pool,
|
|
pooled=pooled,
|
|
server_params=server_params)
|
|
|
|
def _get_reply_q(self):
|
|
with self._reply_q_lock:
|
|
if self._reply_q is not None:
|
|
return self._reply_q
|
|
|
|
reply_q = 'reply_' + uuid.uuid4().hex
|
|
|
|
conn = self._get_connection(pooled=False)
|
|
|
|
self._waiter = ReplyWaiter(self.conf, reply_q, conn,
|
|
self._allowed_remote_exmods)
|
|
|
|
self._reply_q = reply_q
|
|
self._reply_q_conn = conn
|
|
|
|
return self._reply_q
|
|
|
|
def _send(self, target, ctxt, message,
|
|
wait_for_reply=None, timeout=None, envelope=True):
|
|
|
|
# FIXME(markmc): remove this temporary hack
|
|
class Context(object):
|
|
def __init__(self, d):
|
|
self.d = d
|
|
|
|
def to_dict(self):
|
|
return self.d
|
|
|
|
context = Context(ctxt)
|
|
msg = message
|
|
|
|
if wait_for_reply:
|
|
msg_id = uuid.uuid4().hex
|
|
msg.update({'_msg_id': msg_id})
|
|
LOG.debug('MSG_ID is %s' % (msg_id))
|
|
msg.update({'_reply_q': self._get_reply_q()})
|
|
|
|
rpc_amqp._add_unique_id(msg)
|
|
rpc_amqp.pack_context(msg, context)
|
|
|
|
if envelope:
|
|
msg = rpc_common.serialize_msg(msg)
|
|
|
|
if wait_for_reply:
|
|
self._waiter.listen(msg_id)
|
|
|
|
try:
|
|
with self._get_connection() as conn:
|
|
if target.fanout:
|
|
conn.fanout_send(target.topic, msg)
|
|
else:
|
|
topic = target.topic
|
|
if target.server:
|
|
topic = '%s.%s' % (target.topic, target.server)
|
|
conn.topic_send(topic, msg, timeout=timeout)
|
|
|
|
if wait_for_reply:
|
|
result = self._waiter.wait(msg_id, timeout)
|
|
if isinstance(result, Exception):
|
|
raise result
|
|
return result
|
|
finally:
|
|
if wait_for_reply:
|
|
self._waiter.unlisten(msg_id)
|
|
|
|
def send(self, target, ctxt, message, wait_for_reply=None, timeout=None):
|
|
return self._send(target, ctxt, message, wait_for_reply, timeout)
|
|
|
|
def send_notification(self, target, ctxt, message, version):
|
|
return self._send(target, ctxt, message, envelope=(version == 2.0))
|
|
|
|
def listen(self, target):
|
|
conn = self._get_connection(pooled=False)
|
|
|
|
listener = AMQPListener(self, target, conn)
|
|
|
|
conn.declare_topic_consumer(target.topic, listener)
|
|
conn.declare_topic_consumer('%s.%s' % (target.topic, target.server),
|
|
listener)
|
|
conn.declare_fanout_consumer(target.topic, listener)
|
|
|
|
return listener
|
|
|
|
def cleanup(self):
|
|
if self._connection_pool:
|
|
self._connection_pool.empty()
|
|
self._connection_pool = None
|