# 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()