跳到主要内容

WebSocket

问题​

Rust 中如何实现 WebSocket 通信？

答案​

最常用的是 tokio-tungstenite（异步）和 tungstenite（同步）。

服务端（配合 axum）​

use axum::{
    extract::ws::{Message, WebSocket, WebSocketUpgrade},
    response::IntoResponse,
    routing::get,
    Router,
};
use futures::{StreamExt, SinkExt};

async fn ws_handler(ws: WebSocketUpgrade) -> impl IntoResponse {
    ws.on_upgrade(handle_socket)
}

async fn handle_socket(mut socket: WebSocket) {
    // 接收消息
    while let Some(Ok(msg)) = socket.next().await {
        match msg {
            Message::Text(text) => {
                println!("收到: {}", text);
                // Echo 回去
                if socket.send(Message::Text(format!("Echo: {}", text))).await.is_err() {
                    break;
                }
            }
            Message::Close(_) => break,
            _ => {}
        }
    }
    println!("WebSocket 连接关闭");
}

#[tokio::main]
async fn main() {
    let app = Router::new().route("/ws", get(ws_handler));
    let listener = tokio::net::TcpListener::bind("0.0.0.0:3000").await.unwrap();
    axum::serve(listener, app).await.unwrap();
}

客户端​

use tokio_tungstenite::connect_async;
use futures::{StreamExt, SinkExt};
use tungstenite::Message;

async fn ws_client() -> Result<(), Box<dyn std::error::Error>> {
    let (mut ws_stream, _) = connect_async("ws://127.0.0.1:3000/ws").await?;

    // 发送消息
    ws_stream.send(Message::Text("Hello".into())).await?;

    // 接收消息
    if let Some(Ok(msg)) = ws_stream.next().await {
        println!("收到: {}", msg);
    }

    Ok(())
}

心跳与重连​

use tokio::time::{interval, Duration};

async fn handle_socket_with_heartbeat(mut socket: WebSocket) {
    let mut heartbeat = interval(Duration::from_secs(30));

    loop {
        tokio::select! {
            Some(Ok(msg)) = socket.next() => {
                match msg {
                    Message::Text(text) => { /* 处理消息 */ }
                    Message::Ping(data) => {
                        let _ = socket.send(Message::Pong(data)).await;
                    }
                    Message::Close(_) => break,
                    _ => {}
                }
            }
            _ = heartbeat.tick() => {
                if socket.send(Message::Ping(vec![])).await.is_err() {
                    break; // 连接断开
                }
            }
        }
    }
}

常见面试问题​

Q1: WebSocket 和 gRPC 流式通信的区别？​

答案：

维度WebSocketgRPC 流
协议WebSocket 协议HTTP/2
序列化自定义（通常 JSON）Protobuf
类型安全手动Proto 定义
浏览器原生支持需 grpc-web
适用场景聊天、实时推送服务间流式数据

相关链接​