1 files changed, 65 insertions, 0 deletions
diff --git a/third_party/rust/tokio-0.1.22/examples/udp-codec.rs b/third_party/rust/tokio-0.1.22/examples/udp-codec.rs
new file mode 100644
index 0000000000..3657d8cc17
--- /dev/null
+++ b/third_party/rust/tokio-0.1.22/examples/udp-codec.rs
@@ -0,0 +1,65 @@
+//! This example leverages `BytesCodec` to create a UDP client and server which
+//! speak a custom protocol.
+//!
+//! Here we're using the codec from tokio-io 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.
+
+#![deny(warnings)]
+
+extern crate env_logger;
+extern crate tokio;
+extern crate tokio_codec;
+extern crate tokio_io;
+
+use std::net::SocketAddr;
+
+use tokio::net::{UdpFramed, UdpSocket};
+use tokio::prelude::*;
+use tokio_codec::BytesCodec;
+
+fn main() -> Result<(), Box<std::error::Error>> {
+    let _ = env_logger::init();
+
+    let addr: SocketAddr = "127.0.0.1:0".parse()?;
+
+    // Bind both our sockets and then figure out what ports we got.
+    let a = UdpSocket::bind(&addr)?;
+    let b = UdpSocket::bind(&addr)?;
+    let b_addr = b.local_addr()?;
+
+    // We're parsing each socket with the `BytesCodec` included in `tokio_io`, and then we
+    // `split` each codec into the sink/stream halves.
+    let (a_sink, a_stream) = UdpFramed::new(a, BytesCodec::new()).split();
+    let (b_sink, b_stream) = UdpFramed::new(b, BytesCodec::new()).split();
+
+    // Start off by sending a ping from a to b, afterwards we just print out
+    // what they send us and continually send pings
+    // let pings = stream::iter((0..5).map(Ok));
+    let a = a_sink.send(("PING".into(), b_addr)).and_then(|a_sink| {
+        let mut i = 0;
+        let a_stream = a_stream.take(4).map(move |(msg, addr)| {
+            i += 1;
+            println!("[a] recv: {}", String::from_utf8_lossy(&msg));
+            (format!("PING {}", i).into(), addr)
+        });
+        a_sink.send_all(a_stream)
+    });
+
+    // The second client we have will receive the pings from `a` and then send
+    // back pongs.
+    let b_stream = b_stream.map(|(msg, addr)| {
+        println!("[b] recv: {}", String::from_utf8_lossy(&msg));
+        ("PONG".into(), addr)
+    });
+    let b = b_sink.send_all(b_stream);
+
+    // Spawn the sender of pongs and then wait for our pinger to finish.
+    tokio::run({
+        b.join(a)
+            .map(|_| ())
+            .map_err(|e| println!("error = {:?}", e))
+    });
+    Ok(())
+}