python网络编程-编程知识

文章目录

- socket套接字
- 客户端/服务模型
- linux文件描述符fd
- Linux网络IO模型详解
- 网络服务器Apache VS Nginx
- 生产者消费者-生成器版
- 客户端/服务端-多线程版
- IO多路复用TCPServer模型
- 异步IO多路复用TCPServer模型

socket套接字

套接字（socket）是抽象概念,表示TCP连接的一端
通过套接字可以进行数据发送或接收 {IP:Port｝==>> 套接字
TCP连接由两个套接字组成
=｛Socket1:Socket2｝
=｛IP:Port｝｛IP:Port｝

客户端/服务模型

在这里插入图片描述

linux文件描述符fd

Linux一切皆是文件,文件类型 socket.socket.fileno()

普通文件
目录文件
符号链接
设备文件
套接字
- 进程级的文件描述符表 :文件
- 系统级的文件描述符表 :外设
- 文件系统的i-Node表:目录
FIFO

Linux网络IO模型详解

阻塞式IO

在这里插入图片描述

非阻塞式IO

在这里插入图片描述

IO多路复用

在这里插入图片描述

信号驱动式IO

在这里插入图片描述

异步IO

在这里插入图片描述

五种IO比较

在这里插入图片描述

IO多路复用

在这里插入图片描述

select：线性扫描所有监听的文件描述符fd
poll：同选择性能有所优化
Epoll：使用红黑树管理数据结构,性能好

网络服务器Apache VS Nginx

Apache	Nginx
多线程	多路复用
资源占用大	更加轻量
模块多	模块化设计,社区活跃
稳定，缺陷少	静态资源、反向代理
性能较好	性能很好

生产者消费者-生成器版

import time# 消费者
def consumer():cnt = yieldwhile True:if cnt <= 0:# 暂停、让出CPUcnt = yield cntcnt -= 1time.sleep(1)print('consumer consum 1 cnt. cnt =', cnt)# 生产者 (调度器)
def producer(cnt):gen = consumer()# 激活生成器next(gen)gen.send(cnt)while True:cnt += 1print('producer producer 5 cnt. cnt =', cnt)# 调度消费者current = int(time.time())if current % 5 == 0:cnt = gen.send(cnt)else:time.sleep(1)if __name__ == '__main__':producer(0)

客户端/服务端-多线程版

客户端

# -*- encoding=utf-8 -*-
# 客户端import socketclient = socket.socket()
print('client.fileno:', client.fileno())client.connect(('127.0.0.1', 8999))while True:content = str(input('>>>'))client.send(content.encode())content = client.recv(1024)print('client recv content:', content)

服务端

import socket
import threadingdef thread_process(s):while True:content = s.recv(1024)if len(content) == 0:breaks.send(content.upper())print(str(content, encoding='utf-8'))  # 接受来自客户端的消息，并打印出来s.close()server = socket.socket()  # 1. 新建socket
server.bind(('127.0.0.1', 8999))  # 2. 绑定IP和端口（其中127.0.0.1为本机回环IP）
server.listen(5)  # 3. 监听连接while True:s, addr = server.accept()  # 4. 接受连接new_thread = threading.Thread(target=thread_process, args=(s,))print('new thread process connect addr：{}'.format(addr))new_thread.start()

IO多路复用TCPServer模型

# -*- encoding=utf-8 -*-
# IO多路复用TCPServer模型import select
import socketdef serve():server = socket.socket()server.bind(('127.0.0.1', 8999))server.listen(1)epoll = select.epoll()epoll.register(server.fileno(), select.EPOLLIN)connections = {}contents = {}while True:events = epoll.poll(10)for fileno, event in events:if fileno == server.fileno():# 当fd为当前服务器的描述符时,获取新连接s, addr = server.accept()  # 获取套接字和地址print(f"new connection from addr:{addr},fileno:{s.fileno()},socket:{s}")epoll.register(s.fileno(), select.EPOLLIN)connections[s.fileno()] = selif event == select.EPOLLIN:# 当fd不为服务器描述符为客户端描述符时,读事件就绪，有新数据可读s = connections[fileno]content = s.recv(1024)if content:# 当客户端发送数据时print(f"recv content is {content}")print(f"fileno:{fileno} event:{event}")epoll.modify(fileno, select.EPOLLOUT)contents[fileno] = contentelse:# 当客户端退出连接时print(f"recv content is null")print(f"fileno;{fileno} event:{event} ")epoll.unregister(fileno)s.close()connections.pop(fileno)elif event == select.EPOLLOUT:# 当fd不为服务器描述符为客户端描述符时,写事件就绪try:content = contents[fileno]s = connections[fileno]s.send(content)epoll.modify(s.fileno(), select.EPOLLIN)print(f"modify content is {content}")print(f"fileno;{fileno} event:{event} ")except Exception as error:epoll.unregister(fileno)s.close()connections.pop(fileno)contents.pop(fileno)print(f"modify content is failed")print(f"fileno;{fileno} event:{event} ")if __name__ == '__main__':serve()

异步IO多路复用TCPServer模型

import socket
import select
from collections import dequeclass Future:"""可等待对象 Future"""def __init__(self, loop):self.loop = loopself.done = Falseself.co = Nonedef set_done(self):self.done = Truedef set_coroutine(self, co):self.co = codef __await__(self):if not self.done:yield selfreturnclass EventLoop:"""调度器:epoll事件驱动"""current = Nonerunnable = deque()epoll = select.epoll()handler = {}@classmethoddef instance(cls):if not EventLoop.current:EventLoop.current = EventLoop()return EventLoop.currentdef create_future(self):return Future(loop=self)def register_handler(self, fileno, events, handler):self.handler[fileno] = handlerself.epoll.register(fileno, events)def unregister_handler(self, fileno):self.epoll.unregister(fileno)self.handler.pop(fileno)def add_coroutine(self, co):self.runnable.append(co)def run_coroutine(self, co):try:future: Future = co.send(None)future.set_coroutine(co)except Exception as e:print(e)print('coroutine {} stopped'.format(co.__name__))def run_forever(self):while True:while self.runnable:self.run_coroutine(co=self.runnable.popleft())events = self.epoll.poll(1)for fileno, event in events:handler = self.handler.get(fileno)handler()class SocketWrapper:"""套接字协程适配器"""def __init__(self, sock: socket.socket, loop: EventLoop):self.loop = loopself.sock = sockself.sock.setblocking(False)@propertydef fileno(self):return self.sock.fileno()def create_future_for_events(self, events):future: Future = self.loop.create_future()def handler():future.set_done()self.loop.unregister_handler(self.fileno)if future.co:self.loop.add_coroutine(future.co)self.loop.register_handler(self.fileno, events, handler)return futureasync def accept(self):while True:try:sock, addr = self.sock.accept()return SocketWrapper(sock, self.loop), addrexcept BlockingIOError:future = self.create_future_for_events(select.EPOLLIN)await futureasync def recv(self, backlog):while True:try:return self.sock.recv(backlog)except BlockingIOError:future = self.create_future_for_events(select.EPOLLIN)await futureasync def send(self, data):while True:try:return self.sock.send(data)except BlockingIOError:future = self.create_future_for_events(select.EPOLLOUT)await futureclass TCPServer:def __init__(self, loop: EventLoop):self.loop = loopself.listen_sock: SocketWrapper = self.create_listen_socket()self.loop.add_coroutine(self.serve_forever())def create_listen_socket(self, ip='localhost', port=8999):sock = socket.socket()sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)sock.bind((ip, port))sock.listen()return SocketWrapper(sock, self.loop)async def handler_client(self, sock:SocketWrapper):while True:data = await sock.recv(1024)if not data:print('client disconnected')breakawait sock.send(data.upper())async def serve_forever(self):while True:sock, addr = await self.listen_sock.accept()print(f'client connect addr = {addr}')self.loop.add_coroutine(self.handler_client(sock))if __name__ == '__main__':loop = EventLoop.instance()server = TCPServer(loop)loop.run_forever()