Python之socket_udp

UDP服务端&客户端编程

'''
udp编程
创建socket对象，socket.SOCK_DGRAM
绑定ip和port，bind()方法
传输数据
        1.接收数据，socket.recvfrom(bufsize[,flags]),获得一个2元祖(string,address)
        2.发送数据，socket.sendto(string,address) ,发送给某地址信息
释放资源
'''
import socket
server = socket.socket(type=socket.SOCK_DGRAM)
server.bind(('0.0.0.0',9999))
data = server.recv(1024)    #阻塞等待数据
data = server.recvfrom(1024) #阻塞等待数据(value,(ip,port))
server.sendto(b'hello',('127.0.0.1',10000))
server.close()

'''
udp客户端编程流程
创建socket对象，socket.SOCK_DGRAM
发送数据，socket.sendto(string,address)发送给某地址信息
接收数据，socket.recvfrom(bufsize[,flags]),获取一个2元祖(string,address)
释放资源
'''
client = socket.socket(type=socket.SOCK_DGRAM)
raddr = ('127.0.0.1',10000)
client.connect(raddr)
client.sendto(b'hello',raddr)
data = client.recv(1024)    #阻塞等待数据
data = client.recvfrom(1024)#阻塞等待数据，(value,(ip,port))
client.close()

注意：udp时无连接协议，所以可以只有任何一端，例如客户端数据发往服务端，服务端存在与否不重要
udp的socket对象创建后，时没有占用本地地址和端口的
bind()        可以指定本地地址和端口laddr，会立即占用
connect()   可以立即占用本地地址和端口，填充远端地址和端口raddr
sendto()     可以立即占用本地地址和端口，并把数据发往指定远端，只有有了本地绑定端口，sendto就可以向任何远端发送数据
send()        需要和connect()配合使用，可以使用已经从本地端口把数据发往raddr指定的远端
recv()         要求一定要在占用可本地端口后，返回接收的数据
recvfrom()   要求一定要占用了本地端口后，返回接收数据和对端地址的二元组

 udp聊天server

import threading
import socket
import logging
FORMAT = '%(asctime)s,%(threadName)s %(thread)d,%(message)s'
logging.basicConfig(level=logging.INFO,format=FORMAT)

class ChatUDPServer:
    def __init__(self,ip='127.0.0.1',port=9999):
        self.addr = (ip,port)
        self.sock = socket.socket(type=socket.SOCK_DGRAM)
        self.event = threading.Event()
        self.clients = set()
    def start(self):
        self.sock.bind(self.addr)
        threading.Thread(target=self.receive,name='receive').start()

    def receive(self):
        while not self.event.is_set():
            data,raddr= self.sock.recvfrom(1024)
            print(data)
            if data.strip() == b'quit':
                if raddr in self.clients:
                    self.clients.remove(raddr)
                    logging.info('remove leave clients')
                # self.sock.close() 面向无连接的 所以每天udp产生的时候不需要close
                continue
            self.clients.add(raddr)
            for i in self.clients:
                self.sock.sendto('ack {}'.format(data).encode(),i)

    def stop(self):
        for i in self.clients:
            self.sock.sendto(b'bye bye',i)
        self.sock.close()
        self.event.set()

def main():
    cs = ChatUDPServer()
    cs.start()
    while True:
        cmd = input("please set stop command>>>>>>")
        if cmd == 'quit':
            cs.stop()
            break
        logging.info(cs.clients)
        logging.info(threading.enumerate())

if __name__ == '__main__':
    main()

心跳机制：客户端定时往服务端发送的，服务端不需要ack回复，只记录客户端存活

class ChatUDPServer:
    def __init__(self,ip='127.0.0.1',port=9999,interval=10):
        self.addr = (ip,port)
        self.sock = socket.socket(type=socket.SOCK_DGRAM)
        self.event = threading.Event()
        self.clients = {}
        self.interval = interval
    def start(self):
        self.sock.bind(self.addr)
        threading.Thread(target=self.receive,name='receive').start()

    def receive(self):
        while not self.event.is_set():
            localset = set()　　　　　　#迭代字典时不能操作字典，把超时的放在集合里面
            data,raddr= self.sock.recvfrom(1024)
            current = datetime.datetime.now().timestamp() #return float
            if data.strip == b'^hb^':  #从client接收到指定的字符串，做判断
                print('~~~~~~~~',raddr)
                self.clients[raddr] = current
                continue
            elif data.strip() == b'quit':
                if raddr in self.clients:
                    self.clients.pop(raddr,None)
                    logging.info('remove leave clients')
                # self.sock.close() 面向无连接的 所以不需要close
                continue
            self.clients[raddr] = current
            for c,stamp in self.clients.items():
                if current - stamp > self.interval:
                    localset.add(c)
                else:
                    self.sock.sendto('ack {}'.format(data).encode(), i)
            for  i in localset:　　　　
                localset.pop(i)

    def stop(self):
        for i in self.clients:
            self.sock.sendto(b'bye bye',i)
        self.sock.close()
        self.event.set()

client端的更改

    def start(self):
        self.sock.connect(self.addr)
        self.sock.sendto(b'hello server',self.addr)
        threading.Thread(target=self.reveive,name='receive').start()
        threading.Thread(target=self._sendb,name="heartbeat",daemon=True).start()
　　　　　#daemon 随着主线程退出而退出，不用程序员关注线程退出的问题
    def _sendb(self):
        while True:
            self.sock.sendto(b'^hb^',self.addr)