txZMQ 0.1

Twisted bindings for ZeroMQ

txZMQ allows to integrate easily ZeroMQ sockets into Twisted event loop (reactor).

Requirements:

• ZeroMQ library >= 2.1 (heavily tested with 2.1.4)

Python packages required:

• pyzmq

• Twisted

txZMQ introduces support for general ZeroMQ sockets by class ZmqConnection that can do basic event loop integration, sending-receiving messages in non-blocking manner, scatter-gather for multipart messages.

Special descendants of that class, ZmqPubConnection and ZmqSubConnection add special nice features for PUB/SUB sockets.

Other socket types could be easily derived from ZmqConnection except for REQ/REP sockets that may require more work, as reply should be send immediately upon receiving message (currently ZmqConnection will try to read all available message and write queued messages in parallel).

Example:

import sys

from optparse import OptionParser

from twisted.internet import reactor, defer
from twisted.python import log

observer = log.FileLogObserver(sys.stderr)
log.addObserver(observer.emit)

parser = OptionParser("")
parser.add_option("-m", "--method", dest="method", help="0MQ socket connection: bind|connect")
parser.add_option("-e", "--endpoint", dest="endpoint", help="0MQ Endpoint")
parser.add_option("-M", "--mode", dest="mode", help="Mode: publisher|subscriber")

parser.set_defaults(method="connect", endpoint="epgm://eth1;239.0.5.3:10011")

(options, args) = parser.parse_args()

from txZMQ import ZmqFactory, ZmqEndpoint, ZmqPubConnection, ZmqSubConnection
import time

zf = ZmqFactory()
e = ZmqEndpoint(options.method, options.endpoint)

if options.mode == "publisher":
    s = ZmqPubConnection(zf, e)

    def publish():
        data = str(time.time())
        print "publishing %r" % data
        s.publish(data)

        reactor.callLater(1, publish)

    publish()
else:
    s = ZmqSubConnection(zf, e)
    s.subscribe("")

    def doPrint(*args):
        print "message received: %r" % (args, )

    s.gotMessage = doPrint


reactor.run()