Python socket programming design and implementation: send file to server, server compute, receive file back

问题

Here's my current algorithm.

Client site:

initialize socket
send file to server
receive file from server
close socket

Server site:

initialize socket and listen Now in a new thread per request:
receive file from client
computer resulting file (40 second operation)
send resulting file
close socket

For implementation I'm using Python with socket and threading modules, as shown in this tutorial, then I'm repeating the send/receive code on the other sides.

That's my first server/client development experience that involves moving large files. If the design is bad or a different architecture is advised or you have a better tutorial/documents I can use, let me know.

server.py

import socket
from threading import Thread

TCP_IP = 'localhost'
TCP_PORT = 9001
BUFFER_SIZE = 1024

class ClientThread(Thread):

    def __init__(self,ip,port,sock):
        Thread.__init__(self)
        self.ip = ip
        self.port = port
        self.sock = sock
        print (" New thread started for "+ip+":"+str(port))

    def run(self):
        filename='mytext.txt'
        f = open(filename,'rb')
        while True:
            l = f.read(BUFFER_SIZE)
            while (l):
                self.sock.send(l)
                #print('Sent ',repr(l))
                l = f.read(BUFFER_SIZE)
            if not l:
                f.close()
                # self.sock.close()
                break

        with open('server_received_file', 'wb') as f:
            print('file opened')
            while True:
                #print('receiving data...')
                data = self.socks.recv(BUFFER_SIZE)
                print('data=%s', (data))
                if not data:
                    f.close()
                    print ('file close()')
                    break
                # write data to a file
                f.write(data)


tcpsock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcpsock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
tcpsock.bind((TCP_IP, TCP_PORT))
threads = []

while True:
    tcpsock.listen(5)
    print ("Waiting for incoming connections...")
    (conn, (ip,port)) = tcpsock.accept()
    print ('Got connection from ', (ip,port))
    newthread = ClientThread(ip,port,conn)
    newthread.start()
    threads.append(newthread)

for t in threads:
    t.join()

client.py

import socket

TCP_IP = 'localhost'
TCP_PORT = 9001
BUFFER_SIZE = 1024

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((TCP_IP, TCP_PORT))
with open('client_received_file', 'wb') as f:
    print ('file opened')
    while True:
        #print('receiving data...')
        data = s.recv(BUFFER_SIZE)
        print('data=%s', data)
        if not data:
            f.close()
            print ('file close()')
            break
        # write data to a file
        f.write(data)


filename='result.txt'
f = open(filename,'rb')
while True:
    l = f.read(BUFFER_SIZE)
    while (l):
        s.send(l)
        #print('Sent ',repr(l))
        l = f.read(BUFFER_SIZE)
    if not l:
        f.close()
        s.close()
        break

print('Successfully get the file')
s.close()
print('connection closed')

Depending on the input files, the client_received_file is a bit smaller than expected whereas the server_received_file is always empty.

回答1:

You should bind your server before listening.

See https://docs.python.org/2/howto/sockets.html

来源：https://stackoverflow.com/questions/46615493/python-socket-programming-design-and-implementation-send-file-to-server-server

标签

python

sockets

client-server

file-transfer