基于tornado的异步TCPServer以及TCPClient

背景

关于tornado，我这里就不详细讲了，有兴趣的同学可以通过以下两篇博客了解一下：

http://yunjianfei.iteye.com/blog/2185476

http://yunjianfei.iteye.com/blog/2185446

我们一般用tornado来编写web程序，但实际上，tornado底层的代码非常优秀，也可以用这些代码来编写TCP应用。

代码

tornado最突出的特点就是“异步”，所以，我这里编写了一个异步的TCPServer和一个异步的TCPClient来帮助大家理解，下面直接看代码：

文件：tcp_server.py

#!/usr/bin/env python2.7 # -*- coding: utf-8 -*- from tornado import ioloop, httpclient, gen from tornado.gen import Task from tornado.tcpserver import TCPServer import pdb, time, logging from tornado import stack_context from tornado.escape import native_str #Init logging def init_logging():  logger = logging.getLogger()  logger.setLevel(logging.DEBUG)  sh = logging.StreamHandler()  formatter = logging.Formatter('%(asctime)s -%(module)s:%(filename)s-L%(lineno)d-%(levelname)s: %(message)s')  sh.setFormatter(formatter)  logger.addHandler(sh)  logging.info("Current log level is : %s", logging.getLevelName(logger.getEffectiveLevel())) class MyServer(TCPServer):  def __init__(self, io_loop=None, **kwargs):   TCPServer.__init__(self, io_loop=io_loop, **kwargs)  def handle_stream(self, stream, address):   TCPConnection(stream, address, io_loop=self.io_loop) class TCPConnection(object):  def __init__(self, stream, address, io_loop):   self.io_loop = io_loop   self.stream = stream   self.address = address   self.address_family = stream.socket.family   self.EOF = b' END'   self._clear_request_state()   self._message_callback = stack_context.wrap(self._on_message)   self.stream.set_close_callback(self._on_connection_close)   self.stream.read_until(self.EOF, self._message_callback)  def _on_timeout(self):   logging.info("Send message..")   self.write("Hello client!" + self.EOF)  def _on_message(self, data):   try:    timeout = 5    data = native_str(data.decode('latin1'))    logging.info("Received: %s", data)    self.io_loop.add_timeout(self.io_loop.time() + timeout, self._on_timeout)   except Exception, ex:    logging.error("Exception: %s", str(ex))  def _clear_request_state(self):   """Clears the per-request state.   """   self._write_callback = None   self._close_callback = None  def set_close_callback(self, callback):   """Sets a callback that will be run when the connection is closed.   """   self._close_callback = stack_context.wrap(callback)  def _on_connection_close(self):   if self._close_callback is not None:    callback = self._close_callback    self._close_callback = None    callback()   self._clear_request_state()  def close(self):   self.stream.close()   # Remove this reference to self, which would otherwise cause a   self._clear_request_state()  def write(self, chunk, callback=None):   """Writes a chunk of output to the stream."""   if not self.stream.closed():    self._write_callback = stack_context.wrap(callback)    self.stream.write(chunk, self._on_write_complete)  def _on_write_complete(self):   if self._write_callback is not None:    callback = self._write_callback    self._write_callback = None    callback() def main():  init_logging()  server = MyServer()  server.listen(8001)  ioloop.IOLoop.instance().start() if __name__ == "__main__":  try:   main()  except Exception, ex:   print "Ocurred Exception: %s" % str(ex)   quit() 

文件： tcp_client.py

#!/usr/bin/env python2.7 # -*- coding: utf-8 -*- from tornado import ioloop, httpclient, gen from tornado.gen import Task import pdb, time, logging import tornado.ioloop import tornado.iostream import socket #Init logging def init_logging():  logger = logging.getLogger()  logger.setLevel(logging.DEBUG)  sh = logging.StreamHandler()  formatter = logging.Formatter('%(asctime)s -%(module)s:%(filename)s-L%(lineno)d-%(levelname)s: %(message)s')  sh.setFormatter(formatter)  logger.addHandler(sh)  logging.info("Current log level is : %s", logging.getLevelName(logger.getEffectiveLevel())) class TCPClient(object):  def __init__(self, host, port, io_loop=None):   self.host = host   self.port = port   self.io_loop = io_loop   self.shutdown = False   self.stream = None   self.sock_fd = None   self.EOF = b' END'  def get_stream(self):   self.sock_fd = socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0)   self.stream = tornado.iostream.IOStream(self.sock_fd)   self.stream.set_close_callback(self.on_close)  def connect(self):   self.get_stream()   self.stream.connect((self.host, self.port), self.send_message)  def on_receive(self, data):   logging.info("Received: %s", data)   self.stream.close()  def on_close(self):   if self.shutdown:    self.io_loop.stop()  def send_message(self):   logging.info("Send message....")   self.stream.write(b"Hello Server!" + self.EOF)   self.stream.read_until(self.EOF, self.on_receive)   logging.info("After send....")  def set_shutdown(self):   self.shutdown = True def main():  init_logging()  io_loop = tornado.ioloop.IOLoop.instance()  c1 = TCPClient("127.0.0.1", 8001, io_loop)  c2 = TCPClient("127.0.0.1", 8001, io_loop)  c1.connect()  c2.connect()  c2.set_shutdown()  logging.info("**********************start ioloop******************")  io_loop.start() if __name__ == "__main__":  try:   main()  except Exception, ex:   print "Ocurred Exception: %s" % str(ex)   quit() 

分别运行tcp_server.py和tcp_client.py，通过测试结果，可以非常明显的了解到tornado的“异步”，以及强大的性能。

测试结果如下：

tcp_server:

tcp_client: