mirror of
https://github.com/tokio-rs/tokio.git
synced 2025-09-25 12:00:35 +00:00
81 lines
2.5 KiB
Rust
81 lines
2.5 KiB
Rust
//! This example leverages `BytesCodec` to create a UDP client and server which
|
|
//! speak a custom protocol.
|
|
//!
|
|
//! Here we're using the codec from `tokio-codec` to convert a UDP socket to a stream of
|
|
//! client messages. These messages are then processed and returned back as a
|
|
//! new message with a new destination. Overall, we then use this to construct a
|
|
//! "ping pong" pair where two sockets are sending messages back and forth.
|
|
|
|
#![warn(rust_2018_idioms)]
|
|
|
|
use tokio::net::UdpSocket;
|
|
use tokio::{io, time};
|
|
use tokio_stream::StreamExt;
|
|
use tokio_util::codec::BytesCodec;
|
|
use tokio_util::udp::UdpFramed;
|
|
|
|
use bytes::Bytes;
|
|
use futures::{FutureExt, SinkExt};
|
|
use std::env;
|
|
use std::error::Error;
|
|
use std::net::SocketAddr;
|
|
use std::time::Duration;
|
|
|
|
#[tokio::main]
|
|
async fn main() -> Result<(), Box<dyn Error>> {
|
|
let addr = env::args()
|
|
.nth(1)
|
|
.unwrap_or_else(|| "127.0.0.1:0".to_string());
|
|
|
|
// Bind both our sockets and then figure out what ports we got.
|
|
let a = UdpSocket::bind(&addr).await?;
|
|
let b = UdpSocket::bind(&addr).await?;
|
|
|
|
let b_addr = b.local_addr()?;
|
|
|
|
let mut a = UdpFramed::new(a, BytesCodec::new());
|
|
let mut b = UdpFramed::new(b, BytesCodec::new());
|
|
|
|
// Start off by sending a ping from a to b, afterwards we just print out
|
|
// what they send us and continually send pings
|
|
let a = ping(&mut a, b_addr);
|
|
|
|
// The second client we have will receive the pings from `a` and then send
|
|
// back pongs.
|
|
let b = pong(&mut b);
|
|
|
|
// Run both futures simultaneously of `a` and `b` sending messages back and forth.
|
|
match tokio::try_join!(a, b) {
|
|
Err(e) => println!("an error occurred; error = {:?}", e),
|
|
_ => println!("done!"),
|
|
}
|
|
|
|
Ok(())
|
|
}
|
|
|
|
async fn ping(socket: &mut UdpFramed<BytesCodec>, b_addr: SocketAddr) -> Result<(), io::Error> {
|
|
socket.send((Bytes::from(&b"PING"[..]), b_addr)).await?;
|
|
|
|
for _ in 0..4usize {
|
|
let (bytes, addr) = socket.next().map(|e| e.unwrap()).await?;
|
|
|
|
println!("[a] recv: {}", String::from_utf8_lossy(&bytes));
|
|
|
|
socket.send((Bytes::from(&b"PING"[..]), addr)).await?;
|
|
}
|
|
|
|
Ok(())
|
|
}
|
|
|
|
async fn pong(socket: &mut UdpFramed<BytesCodec>) -> Result<(), io::Error> {
|
|
let timeout = Duration::from_millis(200);
|
|
|
|
while let Ok(Some(Ok((bytes, addr)))) = time::timeout(timeout, socket.next()).await {
|
|
println!("[b] recv: {}", String::from_utf8_lossy(&bytes));
|
|
|
|
socket.send((Bytes::from(&b"PONG"[..]), addr)).await?;
|
|
}
|
|
|
|
Ok(())
|
|
}
|