def __init__(self, id, outgoing):
self.id = id
self.outgoing = outgoing
self.incoming = TimeoutDeferredQueue()
self.responses = TimeoutDeferredQueue()
self.queue = None
self.closed = False
self.reason = None
class AMQChannel(object):
def __init__(self, id, outgoing):
self.id = id
self.outgoing = outgoing
self.incoming = TimeoutDeferredQueue()
self.responses = TimeoutDeferredQueue()
self.queue = None
self.closed = False
self.reason = None
def close(self, reason):
if self.closed:
return
self.closed = True
self.reason = reason
self.incoming.close()
self.responses.close()
def dispatch(self, frame, work):
payload = frame.payload
if isinstance(payload, Method):
if payload.method.response:
self.queue = self.responses
else:
self.queue = self.incoming
work.put(self.incoming)
self.queue.put(frame)
@defer.inlineCallbacks
def invoke(self, method, args, content = None):
if self.closed:
raise Closed(self.reason)
frame = Frame(self.id, Method(method, *args))
self.outgoing.put(frame)
if method.content:
if content == None:
content = Content()
self.writeContent(method.klass, content, self.outgoing)
try:
# here we depend on all nowait fields being named nowait
f = method.fields.byname["nowait"]
nowait = args[method.fields.index(f)]
except KeyError:
nowait = False
try:
if not nowait and method.responses:
msg = yield self.responses.get()
resp = msg.payload
# There might be a problem if we have more than one command
# with nowait=False running in the same time.
# The order RabbitMQ server sends responses is undefined.
# If the response for second request comes first we would
# end up in ValueError being raised.
# This is dirty hack: check that we get what we want and
# remove message to the queue otherwise.
# Moreover I don't quite understand the
while resp.method not in method.responses:
self.responses.put(msg)
# More explanation is given by uncommening the print statement:
# print "Expected: %r, Got: %r" %\
# (method.responses, resp.method, )
# Results I obtained in situation which would fail:
#Expected: [Method(name=consume-ok, id=21)], Got: Method(name=declare-ok, id=11)
#Expected: [Method(name=bind-ok, id=21)], Got: Method(name=consume-ok, id=21)
msg = yield self.responses.get()
resp = msg.payload
if resp.method.content:
content = yield readContent(self.responses)
else:
content = None
if resp.method in method.responses:
defer.returnValue(Message(resp.method, resp.args, content))
else:
# With the hack above we should never go into
# this branch.
# If something is messed up we will end up
# in never firing Deferred. For this reason
# this is more a hack than the actual solution.
raise ValueError(resp)
except QueueClosed, e:
if self.closed:
raise Closed(self.reason)
else:
raise e
