#!/usr/bin/env python
     # encoding: utf-8
     #
     # Copyright (c) 2009 Doug Hellmann All rights reserved.
     #
     """
     """
     #end_pymotw_header
     
     import asynchat
     import logging
     import socket
     
     
     class EchoClient(asynchat.async_chat):
         """Sends messages to the server and receives responses.
         """
     
         # Artificially reduce buffer sizes to illustrate
         # sending and receiving partial messages.
         ac_in_buffer_size = 64
         ac_out_buffer_size = 64
         
         def __init__(self, host, port, message):
             self.message = message
             self.received_data = []
             self.logger = logging.getLogger('EchoClient')
             asynchat.async_chat.__init__(self)
             self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
             self.logger.debug('connecting to %s', (host, port))
             self.connect((host, port))
             return
             
         def handle_connect(self):
             self.logger.debug('handle_connect()')
             # Send the command
             self.push('ECHO %d\n' % len(self.message))
             # Send the data
             self.push_with_producer(EchoProducer(self.message, buffer_size=self.ac_out_buffer_size))
             # We expect the data to come back as-is, 
             # so set a length-based terminator
             self.set_terminator(len(self.message))
         
         def collect_incoming_data(self, data):
             """Read an incoming message from the client and put it into our outgoing queue."""
             self.logger.debug('collect_incoming_data() -> (%d)\n"""%s"""', len(data), data)
             self.received_data.append(data)
     
         def found_terminator(self):
             self.logger.debug('found_terminator()')
             received_message = ''.join(self.received_data)
             if received_message == self.message:
                 self.logger.debug('RECEIVED COPY OF MESSAGE')
             else:
                 self.logger.debug('ERROR IN TRANSMISSION')
                 self.logger.debug('EXPECTED "%s"', self.message)
                 self.logger.debug('RECEIVED "%s"', received_message)
             return
     
     class EchoProducer(asynchat.simple_producer):
     
         logger = logging.getLogger('EchoProducer')
     
         def more(self):
             response = asynchat.simple_producer.more(self)
             self.logger.debug('more() -> (%s bytes)\n"""%s"""', len(response), response)
             return response