This document is for Kombu's development version, which can be significantly different from previous releases. Get the stable docs here: 5.0.

Source code for kombu.transport.pyro

"""Pyro transport module for kombu.

Pyro transport, and Kombu Broker daemon.

Requires the :mod:`Pyro4` library to be installed.

Features
========
* Type: Virtual
* Supports Direct: Yes
* Supports Topic: Yes
* Supports Fanout: No
* Supports Priority: No
* Supports TTL: No

Connection String
=================

To use the Pyro transport with Kombu, use an url of the form:

.. code-block::

    pyro://localhost/kombu.broker

The hostname is where the transport will be looking for a Pyro name server,
which is used in turn to locate the kombu.broker Pyro service.
This broker can be launched by simply executing this transport module directly,
with the command: ``python -m kombu.transport.pyro``

Transport Options
=================
"""


import sys
from queue import Empty, Queue

from kombu.exceptions import reraise
from kombu.log import get_logger
from kombu.utils.objects import cached_property

from . import virtual

try:
    import Pyro4 as pyro
    from Pyro4.errors import NamingError
    from Pyro4.util import SerializerBase
except ImportError:          # pragma: no cover
    pyro = NamingError = SerializerBase = None

DEFAULT_PORT = 9090
E_NAMESERVER = """\
Unable to locate pyro nameserver on host {0.hostname}\
"""
E_LOOKUP = """\
Unable to lookup '{0.virtual_host}' in pyro nameserver on host {0.hostname}\
"""

logger = get_logger(__name__)


[docs]class Channel(virtual.Channel): """Pyro Channel."""
[docs] def close(self): super().close() if self.shared_queues: self.shared_queues._pyroRelease()
[docs] def queues(self): return self.shared_queues.get_queue_names()
def _new_queue(self, queue, **kwargs): if queue not in self.queues(): self.shared_queues.new_queue(queue) def _has_queue(self, queue, **kwargs): return self.shared_queues.has_queue(queue) def _get(self, queue, timeout=None): queue = self._queue_for(queue) return self.shared_queues.get(queue) def _queue_for(self, queue): if queue not in self.queues(): self.shared_queues.new_queue(queue) return queue def _put(self, queue, message, **kwargs): queue = self._queue_for(queue) self.shared_queues.put(queue, message) def _size(self, queue): return self.shared_queues.size(queue) def _delete(self, queue, *args, **kwargs): self.shared_queues.delete(queue) def _purge(self, queue): return self.shared_queues.purge(queue)
[docs] def after_reply_message_received(self, queue): pass
@cached_property def shared_queues(self): return self.connection.shared_queues
[docs]class Transport(virtual.Transport): """Pyro Transport.""" Channel = Channel #: memory backend state is global. state = virtual.BrokerState() default_port = DEFAULT_PORT driver_type = driver_name = 'pyro' def _open(self): logger.debug("trying Pyro nameserver to find the broker daemon") conninfo = self.client try: nameserver = pyro.locateNS(host=conninfo.hostname, port=self.default_port) except NamingError: reraise(NamingError, NamingError(E_NAMESERVER.format(conninfo)), sys.exc_info()[2]) try: # name of registered pyro object uri = nameserver.lookup(conninfo.virtual_host) return pyro.Proxy(uri) except NamingError: reraise(NamingError, NamingError(E_LOOKUP.format(conninfo)), sys.exc_info()[2])
[docs] def driver_version(self): return pyro.__version__
@cached_property def shared_queues(self): return self._open()
if pyro is not None: SerializerBase.register_dict_to_class("queue.Empty", lambda cls, data: Empty()) @pyro.expose @pyro.behavior(instance_mode="single") class KombuBroker: """Kombu Broker used by the Pyro transport. You have to run this as a separate (Pyro) service. """ def __init__(self): self.queues = {} def get_queue_names(self): return list(self.queues) def new_queue(self, queue): if queue in self.queues: return # silently ignore the fact that queue already exists self.queues[queue] = Queue() def has_queue(self, queue): return queue in self.queues def get(self, queue): return self.queues[queue].get(block=False) def put(self, queue, message): self.queues[queue].put(message) def size(self, queue): return self.queues[queue].qsize() def delete(self, queue): del self.queues[queue] def purge(self, queue): while True: try: self.queues[queue].get(blocking=False) except Empty: break # launch a Kombu Broker daemon with the command: # ``python -m kombu.transport.pyro`` if __name__ == "__main__": print("Launching Broker for Kombu's Pyro transport.") with pyro.Daemon() as daemon: print("(Expecting a Pyro name server at {}:{})" .format(pyro.config.NS_HOST, pyro.config.NS_PORT)) with pyro.locateNS() as ns: print("You can connect with Kombu using the url " "'pyro://{}/kombu.broker'".format(pyro.config.NS_HOST)) uri = daemon.register(KombuBroker) ns.register("kombu.broker", uri) daemon.requestLoop()