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82 lines
2.7 KiB
Rust
82 lines
2.7 KiB
Rust
//! This is a basic example of leveraging `UdpCodec` to create a simple UDP
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//! client and server which speak a custom protocol.
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//!
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//! Here we're using the a custom codec to convert a UDP socket to a stream of
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//! client messages. These messages are then processed and returned back as a
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//! new message with a new destination. Overall, we then use this to construct a
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//! "ping pong" pair where two sockets are sending messages back and forth.
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extern crate tokio_core;
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extern crate env_logger;
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extern crate futures;
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use std::io;
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use std::net::SocketAddr;
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use std::str;
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use futures::{Future, Stream, Sink};
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use tokio_core::net::{UdpSocket, UdpCodec};
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use tokio_core::reactor::Core;
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pub struct LineCodec;
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impl UdpCodec for LineCodec {
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type In = (SocketAddr, Vec<u8>);
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type Out = (SocketAddr, Vec<u8>);
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fn decode(&mut self, addr: &SocketAddr, buf: &[u8]) -> io::Result<Self::In> {
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Ok((*addr, buf.to_vec()))
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}
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fn encode(&mut self,
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(addr, buf): (SocketAddr, Vec<u8>),
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into: &mut Vec<u8>) -> SocketAddr {
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into.extend(buf);
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return addr
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}
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}
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fn main() {
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drop(env_logger::init());
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let mut core = Core::new().unwrap();
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let handle = core.handle();
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let addr: SocketAddr = "127.0.0.1:0".parse().unwrap();
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// Bind both our sockets and then figure out what ports we got.
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let a = UdpSocket::bind(&addr, &handle).unwrap();
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let b = UdpSocket::bind(&addr, &handle).unwrap();
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let b_addr = b.local_addr().unwrap();
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// We're parsing each socket with the `LineCodec` defined above, and then we
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// `split` each codec into the sink/stream halves.
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let (a_sink, a_stream) = a.framed(LineCodec).split();
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let (b_sink, b_stream) = b.framed(LineCodec).split();
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// Start off by sending a ping from a to b, afterwards we just print out
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// what they send us and continually send pings
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// let pings = stream::iter((0..5).map(Ok));
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let a = a_sink.send((b_addr, b"PING".to_vec())).and_then(|a_sink| {
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let mut i = 0;
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let a_stream = a_stream.take(4).map(move |(addr, msg)| {
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i += 1;
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println!("[a] recv: {}", String::from_utf8_lossy(&msg));
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(addr, format!("PING {}", i).into_bytes())
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});
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a_sink.send_all(a_stream)
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});
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// The second client we have will receive the pings from `a` and then send
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// back pongs.
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let b_stream = b_stream.map(|(addr, msg)| {
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println!("[b] recv: {}", String::from_utf8_lossy(&msg));
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(addr, b"PONG".to_vec())
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});
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let b = b_sink.send_all(b_stream);
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// Spawn the sender of pongs and then wait for our pinger to finish.
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handle.spawn(b.then(|_| Ok(())));
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drop(core.run(a));
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}
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