pickle.loads() 的问题 - 输入不足

Question

I'm trying to make a small multiplayer game and thus need to send objects. Have created server and client and everything is working for sending bytes eg (str("").encode(utf-8)) .

But when I tried to use pickle I've started bumping into issues. Have I made any mistakes below?

Server.py:

import socket
import threading
import pickle

HEADER = 8          #Contains info about incoming msg SIZE! first 8 bytes contains size
FORMAT = "utf-8"
PORT = 5558
SERVER = socket.gethostbyname(socket.gethostname())
ADDR = (SERVER, PORT)
DISCONNECT_MSG = "!Disconnect"

server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_socket.bind(ADDR)

def handle_client(client_socket, client_addr):
    print(f"[NEW CONNECTION] {client_addr} connected!")

    while True:
        try:
            msg = pickle.loads(client_socket.recv(2048))
            print(f"[RECEIVED] {client_addr} - {msg}")
            if msg == DISCONNECT_MSG:
                print(f"[DISCONNECTED] client {client_addr} has disconnected")
                client_socket.close()
                return False
        except socket.error as e:
            print(e)

def start_server(server):
    server.listen()
    print("[STARTED] server is online!")

    while True:
        client_socket, client_addr = server.accept()
        thread = threading.Thread(target=handle_client, args=(client_socket, client_addr))
        thread.start()
        print(f"[ACTIVE CONNECTIONS] {threading.activeCount() - 1}")

print("[STARTING] server is starting...")
start_server(server_socket)

Client.py

import socket
import pickle

HEADER = 8
FORMAT = "utf-8"
PORT = 5558
SERVER = socket.gethostbyname(socket.gethostname())
ADDR = (SERVER, PORT)
DISCONNECT_MSG = "!Disconnect"

class Client:

    def __init__(self):
        self.client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

    def connect_to_server(self, server_address):
        """
        :param server_address: tuple(IP, PORT)
        :return:
        """
        self.get_client_socket().connect(server_address)

    def get_client_socket(self):
        return self.client_socket

    def send_object(self, object):
            msg = pickle.dumps(object)
            self.get_client_socket().sendall(msg)

client = Client()
client.connect_to_server(ADDR)
d = "1"
client.send_object(d)
#client.send_object(DISCONNECT_MSG)

I've also tried to put while loop into send_object() but then after couple of successful receivements I get:

msg = pickle.loads(client_socket.recv(2048))
_pickle.UnpicklingError: invalid load key, '\x00'.

Answer 1

After some research it appears that before trying to unpickle an object you first need to check if received message is not None. Because server is constantly trying to receive message from client, but that is another issue. Code modification in server.py:

def handle_client(client_socket, client_addr):
    print(f"[NEW CONNECTION] {client_addr} connected!")

        while True:
        try:
            msg = client_socket.recv(2048)
            if msg:
                new_msg = pickle.loads(msg[HEADER:])
                print(f"[RECEIVED] {client_addr} - {new_msg}")
                if msg == DISCONNECT_MSG:
                    print(f"[DISCONNECTED] client {client_addr} has disconnected")
                    client_socket.close()
                    return False
        except socket.error as e:
            print(e)

Note -> Until DISCONNECT message is not sent from client it will use much processor time (issue mentioned above)