2019独角兽企业重金招聘Python工程师标准>>> 
之前的是使用原始的socket然后add_handler加入fd到ioloop监听, 其实tornado提供了更高级的抽象, TCPServer和IOStream
服务器代码
python">#! /usr/bin/env python
#coding=utf-8
from tornado.tcpserver import TCPServer
from tornado.ioloop import IOLoop
class Connection(object):
clients = set()
def __init__(self, stream, address):
Connection.clients.add(self)
self._stream = stream
self._address = address
self._stream.set_close_callback(self.on_close)
self.read_message()
print "A new user has entered the chat room.", address
def read_message(self):
self._stream.read_until('\n', self.broadcast_messages)
def broadcast_messages(self, data):
print "User said:", data[:-1], self._address
for conn in Connection.clients:
conn.send_message(data)
self.read_message()
def send_message(self, data):
self._stream.write(data)
def on_close(self):
print "A user has left the chat room.", self._address
Connection.clients.remove(self)
class ChatServer(TCPServer):
def handle_stream(self, stream, address):
"""当连接到来时,这个函数被调用,传入stream(IOStream对象, 而不是原始的fd)和address,
之后就可以用IOStream对象方法收发消息了
"""
print "New connection :", address, stream
Connection(stream, address)
print "connection num is:", len(Connection.clients)
if __name__ == '__main__':
print "Server start ......"
server = ChatServer()
server.listen(8000)
IOLoop.instance().start()------------------------------2014-4-12整理在上面-----------------------------
据说tornado的IOLoop用于tcp服务性能要比twisted还高
参照 ioloop.py
监听的epoll events
python"># Our events map exactly to the epoll events <IOLoop.XXXX>)
NONE = 0
READ = _EPOLLIN
WRITE = _EPOLLOUT
ERROR = _EPOLLERR | _EPOLLHUP三个用于tcp网络编程的接口
python">def add_handler(self, fd, handler, events):
"""Registers the given handler to receive the given events for fd.
The ``events`` argument is a bitwise or of the constants
``IOLoop.READ``, ``IOLoop.WRITE``, and ``IOLoop.ERROR``.
When an event occurs, ``handler(fd, events)`` will be run.
"""
raise NotImplementedError()
def update_handler(self, fd, events):
"""Changes the events we listen for fd."""
raise NotImplementedError()
def remove_handler(self, fd):
"""Stop listening for events on fd."""
raise NotImplementedError()
下面是一个echo server
python">#!/usr/bin/env python
# -*- coding:utf-8 -*-
import Queue
import socket
from functools import partial
from tornado.ioloop import IOLoop
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) # 关闭程序释放端口
sock.setblocking(0) # 将socket设置为非阻塞
server_address = ("127.0.0.1", 9999)
sock.bind(server_address)
sock.listen(20)
fd_map = {} # 文件描述符到socket的映射
message_queue_map = {} # socket到消息队列的映射
fd = sock.fileno()
fd_map[fd] = sock
ioloop = IOLoop.instance()
def handle_client(fd, event, cli_addr):
s = fd_map[fd]
if event & IOLoop.READ:
data = s.recv(1024)
if data:
print "Received %r from %s" % (data, cli_addr)
# 接收到消息更改事件为写, 用于发送数据到对端
ioloop.update_handler(fd, IOLoop.WRITE)
message_queue_map[s].put(data)
else:
print "Closing %s" % cli_addr
ioloop.remove_handler(fd)
s.close()
del message_queue_map[s]
if event & IOLoop.WRITE:
try:
next_msg = message_queue_map[s].get_nowait()
except Queue.Empty:
print "%s queue empty" % cli_addr
ioloop.update_handler(fd, IOLoop.READ)
else:
print "Sending %s to %s" % (next_msg, cli_addr)
s.send(next_msg)
if event & IOLoop.ERROR:
print "Exception on %s" % cli_addr
ioloop.remove_handler(fd)
s.close()
del message_queue_map[s]
"""把socket加入ioloop循环监听是否有READ(可读即有连接)事件到来,如果有则接受连接"""
def handle_server(fd, event):
s = fd_map[fd]
if event & IOLoop.READ:
conn, cli_addr = s.accept()
conn.setblocking(0)
conn_fd = conn.fileno()
fd_map[conn_fd] = conn
handle = partial(handle_client, cli_addr="%s:%d" % (cli_addr)) # 将cli_addr作为默认参数
# 将连接和handle注册为读事件加入到 tornado ioloop
ioloop.add_handler(conn_fd, handle, IOLoop.READ)
message_queue_map[conn] = Queue.Queue() # 创建对应的消息队列
ioloop.add_handler(fd, handle_server, IOLoop.READ)
ioloop.start()