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)