update connect example (#1787)

examples/connect.rs

@@ -16,8 +16,9 @@
 
 #![warn(rust_2018_idioms)]
 
+use futures::StreamExt;
 use tokio::io;
-use tokio_util::codec::{FramedRead, FramedWrite};
+use tokio_util::codec::{BytesCodec, FramedRead, FramedWrite};
 
 use std::env;
 use std::error::Error;
@@ -41,8 +42,9 @@ async fn main() -> Result<(), Box<dyn Error>> {
         .ok_or("this program requires at least one argument")?;
     let addr = addr.parse::<SocketAddr>()?;
 
-    let stdin = FramedRead::new(io::stdin(), codec::Bytes);
+    let stdin = FramedRead::new(io::stdin(), BytesCodec::new());
-    let stdout = FramedWrite::new(io::stdout(), codec::Bytes);
+    let stdin = stdin.map(|i| i.map(|bytes| bytes.freeze()));
+    let stdout = FramedWrite::new(io::stdout(), BytesCodec::new());
 
     if tcp {
         tcp::connect(&addr, stdin, stdout).await?;
@@ -54,25 +56,26 @@ async fn main() -> Result<(), Box<dyn Error>> {
 }
 
 mod tcp {
-    use super::codec;
+    use bytes::Bytes;
-    use futures::StreamExt;
+    use futures::{future, Sink, SinkExt, Stream, StreamExt};
-    use futures::{future, Sink, SinkExt};
     use std::{error::Error, io, net::SocketAddr};
     use tokio::net::TcpStream;
-    use tokio::stream::Stream;
+    use tokio_util::codec::{BytesCodec, FramedRead, FramedWrite};
-    use tokio_util::codec::{FramedRead, FramedWrite};
 
     pub async fn connect(
         addr: &SocketAddr,
-        mut stdin: impl Stream<Item = Result<Vec<u8>, io::Error>> + Unpin,
+        mut stdin: impl Stream<Item = Result<Bytes, io::Error>> + Unpin,
-        mut stdout: impl Sink<Vec<u8>, Error = io::Error> + Unpin,
+        mut stdout: impl Sink<Bytes, Error = io::Error> + Unpin,
     ) -> Result<(), Box<dyn Error>> {
         let mut stream = TcpStream::connect(addr).await?;
         let (r, w) = stream.split();
-        let mut sink = FramedWrite::new(w, codec::Bytes);
+        let mut sink = FramedWrite::new(w, BytesCodec::new());
-        let mut stream = FramedRead::new(r, codec::Bytes)
+        // filter map Result<BytesMut, Error> stream into just a Bytes stream to match stdout Sink
+        // on the event of an Error, log the error and end the stream
+        let mut stream = FramedRead::new(r, BytesCodec::new())
             .filter_map(|i| match i {
-                Ok(i) => future::ready(Some(i)),
+                //BytesMut into Bytes
+                Ok(i) => future::ready(Some(i.freeze())),
                 Err(e) => {
                     println!("failed to read from socket; error={}", e);
                     future::ready(None)
@@ -88,19 +91,18 @@ mod tcp {
 }
 
 mod udp {
-    use tokio::net::udp::{RecvHalf, SendHalf};
+    use bytes::Bytes;
-    use tokio::net::UdpSocket;
+    use futures::{future, Sink, SinkExt, Stream, StreamExt};
-    use tokio::stream::{Stream, StreamExt};
-
-    use futures::{future, Sink, SinkExt};
     use std::error::Error;
     use std::io;
     use std::net::SocketAddr;
+    use tokio::net::udp::{RecvHalf, SendHalf};
+    use tokio::net::UdpSocket;
 
     pub async fn connect(
         addr: &SocketAddr,
-        stdin: impl Stream<Item = Result<Vec<u8>, io::Error>> + Unpin,
+        stdin: impl Stream<Item = Result<Bytes, io::Error>> + Unpin,
-        stdout: impl Sink<Vec<u8>, Error = io::Error> + Unpin,
+        stdout: impl Sink<Bytes, Error = io::Error> + Unpin,
     ) -> Result<(), Box<dyn Error>> {
         // We'll bind our UDP socket to a local IP/port, but for now we
         // basically let the OS pick both of those.
@@ -120,7 +122,7 @@ mod udp {
     }
 
     async fn send(
-        mut stdin: impl Stream<Item = Result<Vec<u8>, io::Error>> + Unpin,
+        mut stdin: impl Stream<Item = Result<Bytes, io::Error>> + Unpin,
         writer: &mut SendHalf,
     ) -> Result<(), io::Error> {
         while let Some(item) = stdin.next().await {
@@ -132,7 +134,7 @@ mod udp {
     }
 
     async fn recv(
-        mut stdout: impl Sink<Vec<u8>, Error = io::Error> + Unpin,
+        mut stdout: impl Sink<Bytes, Error = io::Error> + Unpin,
         reader: &mut RecvHalf,
     ) -> Result<(), io::Error> {
         loop {
@@ -140,47 +142,8 @@ mod udp {
             let n = reader.recv(&mut buf[..]).await?;
 
             if n > 0 {
-                stdout.send(buf).await?;
+                stdout.send(Bytes::from(buf)).await?;
             }
         }
     }
 }
-
-mod codec {
-    use bytes::{BufMut, BytesMut};
-    use std::io;
-    use tokio_util::codec::{Decoder, Encoder};
-
-    /// A simple `Codec` implementation that just ships bytes around.
-    ///
-    /// This type is used for "framing" a TCP/UDP stream of bytes but it's really
-    /// just a convenient method for us to work with streams/sinks for now.
-    /// This'll just take any data read and interpret it as a "frame" and
-    /// conversely just shove data into the output location without looking at
-    /// it.
-    pub struct Bytes;
-
-    impl Decoder for Bytes {
-        type Item = Vec<u8>;
-        type Error = io::Error;
-
-        fn decode(&mut self, buf: &mut BytesMut) -> io::Result<Option<Vec<u8>>> {
-            if !buf.is_empty() {
-                let len = buf.len();
-                Ok(Some(buf.split_to(len).into_iter().collect()))
-            } else {
-                Ok(None)
-            }
-        }
-    }
-
-    impl Encoder for Bytes {
-        type Item = Vec<u8>;
-        type Error = io::Error;
-
-        fn encode(&mut self, data: Vec<u8>, buf: &mut BytesMut) -> io::Result<()> {
-            buf.put(&data[..]);
-            Ok(())
-        }
-    }
-}