• 并发编程之socketserver模块


    一、socketserver模块介绍

    基于tcp套接字,关键的就是两个循环,一个是链接循环,一个是通信循环

    socketserver模块中分两大类:srever类(解决链接问题)和request类(解决通信问题)

    以下述代码为例,分析socketserver源码:

    ftpserver=socketserver.ThreadingTCPServer(('127.0.0.1',8080),FtpServer)
    ftpserver.serve_forever()

    查找属性的顺序:ThreadingTCPServer->ThreadingMixIn->TCPServer->BaseServer

    实例化得到ftpserver,先找类ThreadingTCPServer的__init__,在TCPServer中找到,进而执行server_bind,server_active
    
    找ftpserver下的serve_forever,在BaseServer中找到,进而执行self._handle_request_noblock(),该方法同样是在BaseServer中
    
    执行self._handle_request_noblock()进而执行request, client_address = self.get_request()(就是TCPServer中的self.socket.accept()),然后执行self.process_request(request, client_address)
    
    在ThreadingMixIn中找到process_request,开启多线程应对并发,进而执行process_request_thread,执行self.finish_request(request, client_address)
    
    上述四部分完成了链接循环,本部分开始进入处理通讯部分,在BaseServer中找到finish_request,触发我们自己定义的类的实例化,去找__init__方法,而我们自己定义的类没有该方法,则去它的父类也就是BaseRequestHandler中找....

    源码分析总结:

    基于tcp的socketserver我们自己定义的类中的

    self.server即套接字对象
      
    self.request即一个链接
      
    self.client_address即客户端地址

    基于udp的socketserver我们自己定义的类中的

    self.request是一个元组(第一个元素是客户端发来的数据,第二部分是服务端的udp套接字对象),如(b'adsf', <socket.socket fd=200, family=AddressFamily.AF_INET, type=SocketKind.SOCK_DGRAM, proto=0, 
    laddr=('127.0.0.1', 8080)>) self.client_address即客户端地址 

    二、socketserver应用

     1 import socketserver
     2 class MyTCPhandle(socketserver.BaseRequestHandler):  #必须继承socketserver.BaseRequestHandler这个类
     3     def handle(self): #必须要实现一个handle方法
     4         # print(self.request)  #self.request相当于conn
     5         # print(self.client_address)  #('127.0.0.1', 51393)  self.client_address相当于addr
     6         while True:
     7             try:
     8                 data = self.request.recv(1024)  #IO操作
     9                 self.request.send(data.upper())
    10             except Exception:
    11                 break
    12         self.request.close()
    13 if __name__ == '__main__':
    14         server = socketserver.ThreadingTCPServer(('127.0.0.1',8080),MyTCPhandle) #开启线程。accept方法也包括了
    15         server.allow_reuse_address = True  #默认为False,设为True,相当于 server.setsockopt(SOL_SOCKET,SO_REUSEADDR,1) 重用地址
    16         server.serve_forever() #一直开启,相当于我们以前做的链接循环
    服务端
     1 from socket import *
     2 client  = socket(AF_INET,SOCK_STREAM)
     3 client.connect(('127.0.0.1',8080))
     4 while True:
     5     cmd = input('>>:').strip()
     6     if not cmd:continue
     7     client.send(cmd.encode('utf-8'))
     8     data = client.recv(1024)
     9     print('接受的是:%s'%data.decode('utf-8'))
    10 client.close()
    客户端

    三、上传下载文件(这里只是上传)

     1 import socket
     2 import struct
     3 import json
     4 import subprocess
     5 import os
     6 
     7 class MYTCPServer:
     8     address_family = socket.AF_INET
     9     socket_type = socket.SOCK_STREAM
    10     allow_reuse_address = False
    11     max_packet_size = 8192
    12     coding='utf-8'
    13     request_queue_size = 5
    14     server_dir='file_upload'
    15     def __init__(self, server_address, bind_and_activate=True):
    16         self.server_address=server_address
    17         self.socket = socket.socket(self.address_family,
    18                                     self.socket_type)
    19         if bind_and_activate:
    20             try:
    21                 self.server_bind()
    22                 self.server_activate()
    23             except:
    24                 self.server_close()
    25                 raise
    26 
    27     def server_bind(self):
    28         if self.allow_reuse_address:
    29             self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    30         self.socket.bind(self.server_address)
    31         self.server_address = self.socket.getsockname()
    32 
    33     def server_activate(self):
    34         self.socket.listen(self.request_queue_size)
    35 
    36     def server_close(self):
    37         self.socket.close()
    38 
    39     def get_request(self):
    40         return self.socket.accept()
    41 
    42     def close_request(self, request):
    43         request.close()
    44 
    45     def run(self):
    46         while True:
    47             self.conn,self.client_addr=self.get_request()
    48             print('from client ',self.client_addr)
    49             while True:
    50                 try:
    51                     head_struct = self.conn.recv(4)
    52                     if not head_struct:break
    53 
    54                     head_len = struct.unpack('i', head_struct)[0]
    55                     head_json = self.conn.recv(head_len).decode(self.coding)
    56                     head_dic = json.loads(head_json)
    57 
    58                     print(head_dic)
    59                     #head_dic={'cmd':'put','filename':'a.txt','filesize':123123}
    60                     cmd=head_dic['cmd']
    61                     if hasattr(self,cmd):
    62                         func=getattr(self,cmd)
    63                         func(head_dic)
    64                 except Exception:
    65                     break
    66 
    67     def put(self,args):
    68         file_path=os.path.normpath(os.path.join(
    69             self.server_dir,
    70             args['filename']
    71         ))
    72 
    73         filesize=args['filesize']
    74         recv_size=0
    75         print('----->',file_path)
    76         with open(file_path,'wb') as f:
    77             while recv_size < filesize:
    78                 recv_data=self.conn.recv(self.max_packet_size)
    79                 f.write(recv_data)
    80                 recv_size+=len(recv_data)
    81                 print('recvsize:%s filesize:%s' %(recv_size,filesize))
    82 
    83 
    84 tcpserver1=MYTCPServer(('127.0.0.1',8080))
    85 
    86 tcpserver1.run()
    服务端
     1 import socket
     2 import struct
     3 import json
     4 import os
     5 
     6 
     7 
     8 class MYTCPClient:
     9     address_family = socket.AF_INET
    10     socket_type = socket.SOCK_STREAM
    11     allow_reuse_address = False
    12     max_packet_size = 8192
    13     coding='utf-8'
    14     request_queue_size = 5
    15     def __init__(self, server_address, connect=True):
    16         self.server_address=server_address
    17         self.socket = socket.socket(self.address_family,
    18                                     self.socket_type)
    19         if connect:
    20             try:
    21                 self.client_connect()
    22             except:
    23                 self.client_close()
    24                 raise
    25     def client_connect(self):
    26         self.socket.connect(self.server_address)
    27     def client_close(self):
    28         self.socket.close()
    29     def run(self):
    30         while True:
    31             inp=input(">>: ").strip()
    32             if not inp:continue
    33             l=inp.split()
    34             cmd=l[0]
    35             if hasattr(self,cmd):
    36                 func=getattr(self,cmd)
    37                 func(l)
    38 
    39 
    40     def put(self,args):
    41         cmd=args[0]
    42         filename=args[1]
    43         if not os.path.isfile(filename):
    44             print('file:%s is not exists' %filename)
    45             return
    46         else:
    47             filesize=os.path.getsize(filename)
    48 
    49         head_dic={'cmd':cmd,'filename':os.path.basename(filename),'filesize':filesize}
    50         print(head_dic)
    51         head_json=json.dumps(head_dic)
    52         head_json_bytes=bytes(head_json,encoding=self.coding)
    53 
    54         head_struct=struct.pack('i',len(head_json_bytes))
    55         self.socket.send(head_struct)
    56         self.socket.send(head_json_bytes)
    57         send_size=0
    58         with open(filename,'rb') as f:
    59             for line in f:
    60                 self.socket.send(line)
    61                 send_size+=len(line)
    62                 print(send_size)
    63             else:
    64                 print('upload successful')
    65 client=MYTCPClient(('127.0.0.1',8080))
    66 client.run()
    客户端

     

  • 相关阅读:
    instance of type of object.prototype.tostring 区别
    字符串属性及方法大总结
    数组属性及方法大总结
    在Vue中遇到的各种坑 及性能提升
    find、filter、map的区别
    react 的CDN 连接
    react开启一个项目 webpack版本出错
    react中的jsx详细理解
    Vue 在beaforeCreate时获取data中的数据
    vue点击时动态改变样式 ------- 最简单的方法
  • 原文地址:https://www.cnblogs.com/lianxuebin/p/8585542.html
Copyright © 2020-2023  润新知