rr.py

import os
import sys
import threading

import zmq

def worker(identity, wurl):
    ctx = zmq.Context.instance()
    s = ctx.socket(zmq.REP)
    s.identity = identity
    s.connect(wurl)
    while True:
        msg = s.recv_multipart()
        print("%s received: %s" % (identity, msg))
        s.send_multipart(msg + ['ack', 'from', identity])


def client(identity, curl):
    ctx = zmq.Context.instance()
    s = ctx.socket(zmq.REQ)
    s.identity = identity
    s.connect(curl)
    return s

        
def _relay(ins, outs):
    msg = ins.recv_multipart()
    print("%s received %s" % (ins.identity, msg))
    # the identity prefix is 3 parts for REQ-REP,
    # but 2 parts for ROUTER-DEALER
    if msg[1] == b'':
        n = 3
    else:
        n = 2
    # reverse the identities
    msg[:n] = msg[:n][::-1]
    outs.send_multipart(msg)
    print("%s sent %s" % (outs.identity, msg))

def relay(curl, wurl):
    ctx = zmq.Context.instance()
    
    router1 = ctx.socket(zmq.ROUTER)
    router1.identity = 'ROUTER 1'
    router1.bind(curl)
    router2 = ctx.socket(zmq.ROUTER)
    router2.identity = 'ROUTER 2'
    router2.bind(wurl)
    
    poller = zmq.Poller()
    poller.register(router1, zmq.POLLIN)
    poller.register(router2, zmq.POLLIN)
    
    while True:
        events = dict(poller.poll())
        if router1 in events:
            _relay(router1, router2)
        elif router2 in events:
            _relay(router2, router1)


curl = "inproc://curl"
wurl = "inproc://wurl"

relayer = threading.Thread(target=relay, args=(curl, wurl))
relayer.start()

worker_identities = ['REP1', 'REP2']
workers = [ threading.Thread(target=worker, args=(ident, wurl)) for ident in worker_identities]
[ w.start() for w in workers ]

req1 = client('REQ1', curl)
req2 = client('REQ2', curl)

for wid in worker_identities:
    msg = [wid, "hello from %s" % req1.identity]
    print("REQ1 sent %s" % msg)
    req1.send_multipart(msg)
    msg = [wid, "hello from %s" % req2.identity]
    print("REQ2 sent %s" % msg)
    req2.send_multipart(msg)
    print("REQ1 received: %s" % req1.recv_multipart())
    print("REQ2 received: %s" % req2.recv_multipart())