Tokio server code.

server.rs

// tokio = { version = "1.21.2", features = ["full"] }

use tokio::net::TcpListener;
use tokio::io::{AsyncReadExt, AsyncWriteExt};

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let listener = TcpListener::bind("127.0.0.1:6379").await?;
    loop {
        let (mut socket, _) = listener.accept().await?;
        tokio::spawn(async move {
            let mut buf = vec![0; 1024];
            loop {
                match socket.read(&mut buf).await {
                    Ok(n) => {
                        println!("read {} bytes", n);
                        if n == 0 {
                            println!("socket closed by remote node, return");
                            return;
                        }
                        // Copy the data back to socket
                        if let Err(e) = socket.write_all(&buf[..n]).await {
                            println!("failed to write to socket; err = {:?}", e);
                            return;
                        }
                    }
                    Err(e) => {
                        println!("failed to read from socket; err = {:?}", e);
                        return;
                    }
                }
            }
        });
    }
}