如何使用asyncio正确编写自定义套接字服务器？

Question

Python 2 有一个带有 asyncore.dispatcher 的实现类 我需要在 Python 3 中实现相同的功能。

class Server(asyncore.dispatcher):

    def __init__(self, host, port, socketMap=None):
        asyncore.dispatcher.__init__(self, None, *socketMap*)
        self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
        self.set_reuse_addr()
        self.bind((host, port))
        self.listen(5)
    def handle_accept(self):
        sock, addr = self.accept()
        handler = Handler(self, sock, self._map)

    def run(self):

        while True:
            asyncore.loop(0.001, True, self._map, 1)

        self.handle_close()


class Handler(asyncore.dispatcher):
    def __init__(self, server, sock, socketMap):
        self._server = server
        asyncore.dispatcher.__init__(self, sock, socketMap)

    def handle_read(self):
        buf = self.recv(8192)
        print(buf)
    def handle_write(self): 

        sent = self.send("hello")

也许有实施示例或者他们可以告诉我从哪里开始 我试着写

async def echo(connection: socket,
               loop: AbstractEventLoop) -> None:
    while data := await loop.sock_recv(connection, 1024):
        await loop.sock_sendall(connection, data)
 
async def listen_for_connection(server_socket: socket,
                                loop: AbstractEventLoop):
    while True:
        connection, address = await loop.sock_accept(server_socket)
        connection.setblocking(False)
        print(f"Got a connection from {address}")
        asyncio.create_task(echo(connection, loop))
async def main():
    server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    server_address = ('localhost', 8000)
    server_socket.setblocking(False)
    server_socket.bind(server_address)
    server_socket.listen() 
    await listen_for_connection(server_socket, asyncio.get_event_loop()) 
asyncio.run(main())

我现在不知道如何创建与服务器类似的类（asyncore.dispatcher）

Answer 1

要启动一个简单的异步回显服务器来侦听某个地址/端口，您可以使用以下示例：

import asyncio


async def handle_echo(reader, writer):
    data = await reader.read(100)

    message = data.decode()
    addr = writer.get_extra_info("peername")

    print(f"Received {message} from {addr}")
    print(f"Send: {message}")

    writer.write(data)
    await writer.drain()

    print("Closing the connection")
    writer.close()


async def main():
    server = await asyncio.start_server(handle_echo, "127.0.0.1", 5000)

    addr = server.sockets[0].getsockname()
    print(f"Serving on {addr}")

    async with server:
        await server.serve_forever()


asyncio.run(main())

运行代码将启动服务器。在另一个终端中，您可以键入以下命令：

$ echo "Hello World" | curl telnet://127.0.0.1:5000

服务器将响应

Hello World