Changed around the sockets in the bridge for claritly, tidied up the main code and added some module docs

examples/chat_bridge.py

@@ -4,13 +4,13 @@ from zmq.devices import Device
 
         
 if __name__ == "__main__":
-    usage = 'usage: chat_bridge pub_address sub_address'
+    usage = 'usage: chat_bridge sub_address pub_address'
     if len (sys.argv) != 3:
         print usage
         sys.exit(1)
 
-    pub_addr = sys.argv[1]
-    sub_addr = sys.argv[2]
+    sub_addr = sys.argv[1]
+    pub_addr = sys.argv[2]
     print "Recieving on %s" % sub_addr
     print "Sending on %s" % pub_addr
     device = Device(FORWARDER, SUB, PUB)

examples/distributed_websocket_chat.py

@@ -1,5 +1,19 @@
-import os, sys
+"""This is a websocket chat example with many servers. A client can connect to
+any of the servers and their messages will be received by all clients connected
+to any of the servers.
 
+Run the examples like this:
+
+$ python examples/chat_bridge.py tcp://127.0.0.1:12345 tcp://127.0.0.1:12346
+
+and the servers like this (changing the port for each one obviously):
+
+$ python examples/distributed_websocket_chat.py -p tcp://127.0.0.1:12345 -s tcp://127.0.0.1:12346 7000
+
+So all messages are published to port 12345 and the device forwards all the
+messages to 12346 where they are subscribed to
+"""
+import os, sys
 import eventlet
 from collections import defaultdict
 from eventlet import spawn_n, sleep
@@ -30,7 +44,8 @@ class IDName(object):
 
     def unpack_message(self, msg):
         sender, message = msg
-        sender_name = 'you said' if sender.id == self.id else '%s says' % sender
+        sender_name = 'you said' if sender.id == self.id \
+                                 else '%s says' % sender
         return "%s: %s" % (sender_name, message)
 
 
@@ -39,11 +54,7 @@ participants = defaultdict(IDName)
 def subscribe_and_distribute(sub_socket):
     global participants
     while True:
-        try:
-
-            msg = sub_socket.recv_pyobj()
-        except:
-            print 'exception in recv'
+        msg = sub_socket.recv_pyobj()
         for ws, name_id in participants.items():
             to_send = name_id.unpack_message(msg)
             if to_send:
@@ -69,8 +80,6 @@ def handle(ws):
                 m = 'Changed name from %s' % old_name
             pub_socket.send_pyobj(name_id.pack_message(m))
             sleep()
-    except:
-        raise
     finally:
         del participants[ws]
                   
@@ -105,16 +114,13 @@ if __name__ == "__main__":
         pub_socket = ctx.socket(zmq.PUB)
         pub_socket.connect(pub_addr)
         print "Publishing to %s" % pub_addr
-    except:
-        raise
-
-    try:
         sub_socket = ctx.socket(zmq.SUB)
         sub_socket.connect(sub_addr)
         sub_socket.setsockopt(zmq.SUBSCRIBE, "")
         print "Subscribing to %s" % sub_addr
     except:
-        raise
+        print "Couldn't create sockets\n", usage
+        sys.exit(1)
 
     spawn_n(subscribe_and_distribute, sub_socket)
     listener = eventlet.listen(('127.0.0.1', port))