python基础----socketserver多并发实现、FTP上传多并发

一、socketserver多并发                                                             

基于tcp的套接字，关键就是两个循环，一个链接循环，一个通信循环

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

    (1)server类

    (2)request类

    (3)继承关系

以下述代码为例，分析socketserver源码：

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

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

1. 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
2. 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
3. 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)
4. 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)
5. 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....

    (5)源码分析总结

基于tcp的socketserver我们自己定义的类中的

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

基于udp的socketserver我们自己定义的类中的

1. 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)>)
2. self.client_address即客户端地址

二、FTP上传多并发                                                                      

 1 import socketserver     #导入多并发模块
 2 import struct
 3 import json
 4 import subprocess
 5 import os
 6
 7 class MYTCPServer(socketserver.BaseRequestHandler):
 8
 9     max_packet_size = 8192
10
11     coding=‘utf-8‘
12     BASE_DIR=os.path.dirname(os.path.abspath(__file__))
13
14     server_dir=‘file_upload‘
15
16     def handle(self):
17         while True:
18             try:
19                 head_struct = self.request.recv(4)
20                 if not head_struct:break
21
22                 head_len = struct.unpack(‘i‘, head_struct)[0]
23                 head_json = self.request.recv(head_len).decode(self.coding)
24                 head_dic = json.loads(head_json)
25
26                 print(head_dic)
27                 #head_dic={‘cmd‘:‘put‘,‘filename‘:‘a.txt‘,‘filesize‘:123123}
28                 cmd=head_dic[‘cmd‘]
29                 if hasattr(self,cmd):
30                     func=getattr(self,cmd)
31                     func(head_dic)
32             except Exception:
33                 break
34
35     def put(self,args):
36         file_path=os.path.normpath(os.path.join(
37             self.BASE_DIR,
38             self.server_dir,
39             args[‘filename‘]
40         ))
41
42         filesize=args[‘filesize‘]
43         recv_size=0
44         print(‘----->‘,file_path)
45         with open(file_path,‘wb‘) as f:
46             while recv_size < filesize:
47                 recv_data=self.request.recv(self.max_packet_size)
48                 f.write(recv_data)
49                 recv_size+=len(recv_data)
50                 print(‘recvsize:%s filesize:%s‘ %(recv_size,filesize))
51
52
53
54
55 if __name__ == ‘__main__‘:
56     obj=socketserver.ThreadingTCPServer((‘127.0.0.1‘,8080),MYTCPServer)
57     obj.serve_forever()

ftp_server

 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
11     socket_type = socket.SOCK_STREAM
12
13     allow_reuse_address = False
14
15     max_packet_size = 8192
16
17     coding=‘utf-8‘
18
19     request_queue_size = 5
20
21     def __init__(self, server_address, connect=True):
22         self.server_address=server_address
23         self.socket = socket.socket(self.address_family,
24                                     self.socket_type)
25         if connect:
26             try:
27                 self.client_connect()
28             except:
29                 self.client_close()
30                 raise
31
32     def client_connect(self):
33         self.socket.connect(self.server_address)
34
35     def client_close(self):
36         self.socket.close()
37
38     def run(self):
39         while True:
40             inp=input(">>: ").strip()
41             if not inp:continue
42             l=inp.split()
43             cmd=l[0]
44             if hasattr(self,cmd):
45                 func=getattr(self,cmd)
46                 func(l)
47
48
49     def put(self,args):
50         cmd=args[0]
51         filename=args[1]
52         if not os.path.isfile(filename):
53             print(‘file:%s is not exists‘ %filename)
54             return
55         else:
56             filesize=os.path.getsize(filename)
57
58         head_dic={‘cmd‘:cmd,‘filename‘:os.path.basename(filename),‘filesize‘:filesize}
59         print(head_dic)
60         head_json=json.dumps(head_dic)
61         head_json_bytes=bytes(head_json,encoding=self.coding)
62
63         head_struct=struct.pack(‘i‘,len(head_json_bytes))
64         self.socket.send(head_struct)
65         self.socket.send(head_json_bytes)
66         send_size=0
67         with open(filename,‘rb‘) as f:
68             for line in f:
69                 self.socket.send(line)
70                 send_size+=len(line)
71                 print(send_size)
72             else:
73                 print(‘upload successful‘)
74
75
76
77
78 client=MYTCPClient((‘127.0.0.1‘,8080))
79
80 client.run()

ftp_client