# asynchatPong

 # Listener using asynchat

 # Not related to BLIP - just to aid in my understanding of what's going on

 # Sends "Pong" when it gets "Ping"

 import sys

 import traceback

 import socket

 import asyncore

 import asynchat

 class asynchatPongListener(asyncore.dispatcher):

     def __init__(self, port):

         asyncore.dispatcher.__init__(self)

         self.create_socket(socket.AF_INET, socket.SOCK_STREAM)

         self.bind( ('', port) )

         self.listen(2)

         self.shouldAccept = True

     def handle_accept(self):

         if self.shouldAccept:

             sock, addr = self.accept()

             self.conn = asynchatPong(sock, self)

             self.shouldAccept = False

     def handle_error(self):

         (typ,val,trace) = sys.exc_info()

         print "Listener caught: %s %s\n%s" % (typ,val,traceback.format_exc())

         self.close()

     def handle_close(self):

         print "Listener got close"

         asyncore.dispatcher.handle_close(self)

 class asynchatPong(asynchat.async_chat):

     def __init__(self, socket, listener):

         asynchat.async_chat.__init__(self, socket)

         self._listener = listener

         self.set_terminator("Ping")

     def collect_incoming_data(self, data):

         """called when arbitrary amount of data arrives. we just eat it"""

         pass

     def found_terminator(self):

         """called when the terminator we set is found"""

         print "Found 'Ping'"

         self.push("Pong")

         print "Sent 'Pong'"

     def handle_close(self):

         print "Closed; closing listener"

         self._listener.close()

         asynchat.async_chat.handle_close(self)

 if __name__ == '__main__':

     pong = asynchatPongListener(1337)

     asyncore.loop()