init

src/relay.rs

@@ -0,0 +1,55 @@
+use color_eyre::Result;
+use tokio::io::{AsyncRead, AsyncWrite, copy_bidirectional};
+
+/// Bidirectional relay between two async streams.
+/// Returns when either direction hits EOF or an error.
+pub async fn relay<A, B>(mut a: A, mut b: B) -> Result<()>
+where
+    A: AsyncRead + AsyncWrite + Unpin,
+    B: AsyncRead + AsyncWrite + Unpin,
+{
+    copy_bidirectional(&mut a, &mut b).await?;
+    Ok(())
+}
+
+/// Wrapper to combine a QUIC send+recv into a single AsyncRead+AsyncWrite.
+pub struct QuicBiStream {
+    pub send: quinn::SendStream,
+    pub recv: quinn::RecvStream,
+}
+
+impl tokio::io::AsyncRead for QuicBiStream {
+    fn poll_read(
+        mut self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+        buf: &mut tokio::io::ReadBuf<'_>,
+    ) -> std::task::Poll<std::io::Result<()>> {
+        std::pin::Pin::new(&mut self.recv).poll_read(cx, buf)
+    }
+}
+
+impl tokio::io::AsyncWrite for QuicBiStream {
+    fn poll_write(
+        mut self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+        buf: &[u8],
+    ) -> std::task::Poll<std::io::Result<usize>> {
+        std::pin::Pin::new(&mut self.send)
+            .poll_write(cx, buf)
+            .map(|r| r.map_err(std::io::Error::other))
+    }
+
+    fn poll_flush(
+        mut self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<std::io::Result<()>> {
+        std::pin::Pin::new(&mut self.send).poll_flush(cx)
+    }
+
+    fn poll_shutdown(
+        mut self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<std::io::Result<()>> {
+        std::pin::Pin::new(&mut self.send).poll_shutdown(cx)
+    }
+}