Websocket方案：回调或协程

在制定交易策略之前，通常需要从 cex websocket 接口检索数据。因此，采用优秀的 websocket 数据检索解决方案至关重要。本文将比较两种不同的 websocket 客户端实现。

协程和回调的区别

协程

在 websocket 的上下文中，可以利用协程来有效地处理异步任务。例如，可以采用异步协程以非阻塞方式管理传入消息。以下是设置服务器的简单代码示例：

设置服务器的代码示例：

#!/usr/bin/env python
import asyncio
import websockets

# the websocket parameter is an instance of the WebSocketServerProtocol class, 
# and it represents the communication channel between the server and 
# a specific client connected to the WebSocket server
async def handler(websocket):
    while True:
        message = await websocket.recv()
        print(message)
        # Send the same message back to the client
        await websocket.send(f"Server echoing: {message}")

# will be called each time a new client connects to the server
async def main():
    # "" represents loopback interface that allows 
    # communication between processes on the same device.
    async with websockets.serve(handler, "", 8001):
        await asyncio.Future()  # run forever

if __name__ == "__main__":
    asyncio.run(main())

客户端代码：

import asyncio
import websockets

async def connect_to_server():
    uri = "ws://localhost:8001"  # Change the URI to match your server address

    async with websockets.connect(uri) as websocket:
        while True:
            message = input("Enter a message to send to the server (or 'exit' to quit): ")
            
            if message.lower() == 'exit':
                break

            await websocket.send(message)
            
            # Receive and print the echoed message from the server
            response = await websocket.recv()
            print(f"Received from server: {response}")

if __name__ == "__main__":
    asyncio.run(connect_to_server())

回调

在 websockets 领域，回调可用于定义在特定事件（如接收消息、建立连接或遇到错误）发生时执行的函数。现在让我们使用回调方案重写客户端代码：

import websocket

def on_message(ws, message):
    print(f"Received from server: {message}")

def connect_to_server():
    uri = "ws://localhost:8001"  # Change the URI to match your server address

    ws = websocket.WebSocketApp(uri, on_message=on_message)
    
    while True:
        user_input = input("Enter a message to send to the server (or 'exit' to quit): ")
        
        if user_input.lower() == 'exit':
            break

        ws.send(user_input)
    
    ws.close()

if __name__ == "__main__":
    connect_to_server()

区别

回调在较旧的异步代码中很普遍，并且可以在严重依赖事件驱动架构的系统中使用。另一方面，协程是现代 Python 异步编程的首选方法，尤其是引入了 async/await 语法后。

我喜欢协程方案主要是因为它为异步编程提供了更优雅、更易读的解决方案，使其成为现代 Python 开发中的首选方法。

作者：0xCryptoQuant