# 客户端 import struct import json import socket import os client = socket.socket() client.connect(('127.0.0.1', 8080)) file_size = os.path.getsize(r'/Users/jiboyuan/PycharmProjects/aboutsocket/10 解决粘包问题终极版.mp4') file_path = r'/Users/jiboyuan/PycharmProjects/aboutsocket/10 解决粘包问题终极版.mp4' data_dic = { 'file_name': '**上线啦.mp4', 'file_size': file_size } header_json = json.dumps(data_dic) header_bytes = header_json.encode('utf-8') # 制作字典的报头 header = struct.pack('i', len(header_bytes)) # 发送报头 client.send(header) # 发字典数据 client.send(header_bytes) # 打开文件发送文件数据 with open(file_path,'rb') as f: for line in f: client.send(line) # 服务端 import socket import json import struct server = socket.socket() server.bind(('127.0.0.1', 8080)) server.listen(5) while True: conn, addr = server.accept() while True: try: header = conn.recv(4) if len(header) == 0:break dic_len = struct.unpack('i', header)[0] real_dic = json.loads(conn.recv(dic_len).decode('utf-8')) print(real_dic) file_name = real_dic.get('file_name') file_size = real_dic.get('file_size') recv_size = 0 with open(file_name, 'wb') as f: while recv_size < file_size: recv_data = conn.recv(1024) f.write(recv_data) recv_size += len(recv_data) except ConnectionResetError: break
# 服务端 import socket server = socket.socket(type=socket.SOCK_DGRAM) server.bind(('127.0.0.1', 8080)) msg, addr = server.recvfrom(1024) print(msg.decode('utf-8')) server.sendto(b'hello', addr) server.close() #客户端 import socket client = socket.socket(type=socket.SOCK_DGRAM) server_addr = ('127.0.0.1', 8080) client.sendto(b'hello server baby!', server_addr) msg, addr = client.recvfrom(1024) print(msg, addr)
udp特点 >>> 无链接,类似于发短信,发了就行对方爱回不回,没有任何关系
将服务端关了,客户端起起来照样能够发数据。因为不需要考虑服务端能不能收到
# 验证udp协议有无粘包问题 import socket server = socket.socket(type=socket.SOCK_DGRAM) server.bind(('127.0.0.1',8080)) print(server.recvfrom(1024)) print(server.recvfrom(1024)) print(server.recvfrom(1024)) import socket client = socket.socket(type=socket.SOCK_DGRAM) server_addr = ('127.0.0.1',8080) client.sendto(b'hello',server_addr) client.sendto(b'hello',server_addr) client.sendto(b'hello',server_addr)
# 服务端 import socket server = socket.socket(type=socket.SOCK_DGRAM) server.bind(('127.0.0.1', 8080)) while True: msg, addr = server.recvfrom(1024) print(addr) print(msg.decode('utf-8')) info = input('>>>:').encode('utf-8') server.sendto(info, addr) server.close() # 多个客户端 import socket client = socket.socket(type=socket.SOCK_DGRAM) server_addr = ('127.0.0.1', 8080) while True: info = input('>>>:') info = ('来自客户端1的消息:%s'%info).encode('utf-8') # 改中文备注即可 client.sendto(info, server_addr) msg, addr = client.recvfrom(1024) print(msg.decode('utf-8'), addr) client.close()
UDP协议就类似于发短信
# TCP socketserver使用 import socketserver class MyTcpServer(socketserver.BaseRequestHandler): def handle(self): while True: try: data = self.request.recv(1024) # 对于tcp,self.request相当于conn对象 if len(data) == 0:break print(data) self.request.send(data.upper()) except ConnectionResetError: break if __name__ == '__main__': server = socketserver.ThreadingTCPServer(('127.0.0.1',8081),MyTcpServer) server.serve_forever() # UDP socketserver使用 import socketserver class MyUdpServer(socketserver.BaseRequestHandler): def handle(self): while True: data, sock = self.request print(data) sock.sendto(data.upper(), self.client_address) if __name__ == '__main__': server = socketserver.ThreadingUDPServer(('127.0.0.1', 8080), MyUdpServer) server.serve_forever()
批处理(磁带)
- 脱机批处理系统
>>> 提高计算机CPU利用率的问题(问题:串行时并没有空间上的复用)
串行:一个程序完完整整的运行完毕,才能运行下一个程序
多道技术:
- 空间上的复用(多个程序共一套硬件设备,它是多道技术实现时间上的复用的基础,
不然还要去硬盘读数据)
- 时间上的复用(单个cpu的电脑上,起多个应用程序。cpu快速切换,给人的感觉是同时运行)
cpu两种情况下才会切换:(先保存当前程序的运行状态)
- 一个任务占用cpu时间过长或被操作系统强行剥夺走cpu的执行权限(比起串行效率反而降低)
- 一个任务执行过程中遇到io操作,也会被操作系统强行剥夺走cpu的执行权限(比起串行效率提高)
并发:看上去像同时进行的
并行:同时运行
补充:单核的计算机不可能实现并行!