我如何使用异步套接字在连接的客户端之间切换

Posted 2023-03-15

【中文标题】我如何使用异步套接字在连接的客户端之间切换

【英文标题】：how do i switch between connected clients with asyncio sockets

【发布时间】：2022-01-14 20:00:04

【问题描述】：

我正在尝试制作一个套接字服务器，它能够使用 asyncio 套接字连接多个客户端，并且能够轻松地在它通信的客户端之间切换，同时仍然连接所有客户端。我以为会有某种类型的客户端 FD，比如在套接字中，但是我查看了文档并没有找到任何东西，或者我错过了。

这是我的服务器代码：

import socket
import asyncio


host = "localhost"

port = 9998

list_of_auths = ['desktop-llpeu0p\\tomiss', 'desktop-llpeu0p\\tomisss',
                 'desktop-llpeu0p\\tomissss', 'desktop-llpeu0p\\tomisssss']

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print('socket initiated.')
confirmed = 'CONFIRMED'
deny = 'denied'
#(so i dont forget) to get recv in async do: var = (await reader.read(4096)).decode('utf-8') if -1 then it will read all
#(so i dont forget) to write sendall do: writer.write(var.encode('utf-8')) should be used with await writer.drain()

async def handle_client(reader, writer):
    idrecv = (await reader.read(255)).decode('utf-8')
    if idrecv in list_of_auths:
        writer.write(confirmed.encode('utf-8'))
    else:
        writer.write(deny.encode('utf-8'))
        writer.close()
    request = None
    while request != 'quit':
        print("second checkpoint")

    writer.close()

async def run_server():
    print("first checkpoint")
    server = await asyncio.start_server(handle_client, host, port)
    async with server:
        await server.serve_forever()
asyncio.run(run_server())

此代码允许多个客户端同时连接；但是，它只能让我与最后一个连接的人进行通信。

【参考方案1】：

我建议这样实现：

class SocketHandler(asyncio.Protocol):
    def __init__(self):
        asyncio.Protocol.__init__(self)
        self.transport = None
        self.peername = None
        # your other code

    def connection_made(self, transport):
        """ incoming connection """
        global ALL_CONNECTIONS
        self.transport = transport
        self.peername = transport.get_extra_info('peername')
        ALL_CONNECTIONS.append(self)
        # your other code

    def connection_lost(self, exception):
        self.close()
        # your other code

    def data_received(self, data):
        # your code handling incoming data
    

    def close(self):
        try:
            self.transport.close()
        except AttributeError:
            pass


# global list to store all connections
ALL_CONNECTIONS = []

def send_to_all(message):
    """ sending a message to all connected clients """
    global ALL_CONNECTIONS
    for sh in ALL_CONNECTIONS:
        # here you can also check sh.peername to know which client it is
        if sh.transport is not None:
            sh.transport.write(message)


port = 5060
loop = asyncio.get_event_loop()
coro = loop.create_server(SocketHandler, '', port)
server = loop.run_until_complete(coro)
loop.run_forever()

这样，到服务器的每个连接都由SocketHandler 的实例表示。每当您在此实例中处理一些数据时，您就知道它是哪个客户端连接。

【讨论】：

一旦我拥有了大约 4 个客户端的全局列表，编写器函数的代码是什么？

成功了，谢谢