every.channel: sanitized baseline

third_party/iroh-live/web-transport-iroh/src/send.rs

@@ -0,0 +1,142 @@
+use std::{
+    io,
+    pin::Pin,
+    task::{Context, Poll},
+};
+
+use bytes::{Buf, Bytes};
+
+use crate::{ClosedStream, SessionError, WriteError};
+
+/// A stream that can be used to send bytes. See [`quinn::SendStream`].
+///
+/// This wrapper is mainly needed for error codes, which is unfortunate.
+/// WebTransport uses u32 error codes and they're mapped in a reserved HTTP/3 error space.
+#[derive(Debug)]
+pub struct SendStream {
+    stream: quinn::SendStream,
+}
+
+impl SendStream {
+    pub(crate) fn new(stream: quinn::SendStream) -> Self {
+        Self { stream }
+    }
+
+    /// Abruptly reset the stream with the provided error code. See [`quinn::SendStream::reset`].
+    /// This is a u32 with WebTransport because we share the error space with HTTP/3.
+    pub fn reset(&mut self, code: u32) -> Result<(), ClosedStream> {
+        let code = web_transport_proto::error_to_http3(code);
+        let code = quinn::VarInt::try_from(code).unwrap();
+        self.stream.reset(code).map_err(Into::into)
+    }
+
+    /// Wait until the stream has been stopped and return the error code. See [`quinn::SendStream::stopped`].
+    ///
+    /// Unlike Quinn, this returns None if the code is not a valid WebTransport error code.
+    /// Also unlike Quinn, this returns a SessionError, not a StoppedError, because 0-RTT is not supported.
+    pub async fn stopped(&mut self) -> Result<Option<u32>, SessionError> {
+        match self.stream.stopped().await {
+            Ok(Some(code)) => Ok(web_transport_proto::error_from_http3(code.into_inner())),
+            Ok(None) => Ok(None),
+            Err(quinn::StoppedError::ConnectionLost(e)) => Err(e.into()),
+            Err(quinn::StoppedError::ZeroRttRejected) => unreachable!("0-RTT not supported"),
+        }
+    }
+
+    // Unfortunately, we have to wrap WriteError for a bunch of functions.
+
+    /// Write some data to the stream, returning the size written. See [`quinn::SendStream::write`].
+    pub async fn write(&mut self, buf: &[u8]) -> Result<usize, WriteError> {
+        self.stream.write(buf).await.map_err(Into::into)
+    }
+
+    /// Write all of the data to the stream. See [`quinn::SendStream::write_all`].
+    pub async fn write_all(&mut self, buf: &[u8]) -> Result<(), WriteError> {
+        self.stream.write_all(buf).await.map_err(Into::into)
+    }
+
+    /// Write chunks of data to the stream. See [`quinn::SendStream::write_chunks`].
+    pub async fn write_chunks(&mut self, bufs: &mut [Bytes]) -> Result<quinn::Written, WriteError> {
+        self.stream.write_chunks(bufs).await.map_err(Into::into)
+    }
+
+    /// Write a chunk of data to the stream. See [`quinn::SendStream::write_chunk`].
+    pub async fn write_chunk(&mut self, buf: Bytes) -> Result<(), WriteError> {
+        self.stream.write_chunk(buf).await.map_err(Into::into)
+    }
+
+    /// Write all of the chunks of data to the stream. See [`quinn::SendStream::write_all_chunks`].
+    pub async fn write_all_chunks(&mut self, bufs: &mut [Bytes]) -> Result<(), WriteError> {
+        self.stream.write_all_chunks(bufs).await.map_err(Into::into)
+    }
+
+    /// Mark the stream as finished, such that no more data can be written. See [`quinn::SendStream::finish`].
+    pub fn finish(&mut self) -> Result<(), ClosedStream> {
+        self.stream.finish().map_err(Into::into)
+    }
+
+    pub fn set_priority(&self, order: i32) -> Result<(), ClosedStream> {
+        self.stream.set_priority(order).map_err(Into::into)
+    }
+
+    pub fn priority(&self) -> Result<i32, ClosedStream> {
+        self.stream.priority().map_err(Into::into)
+    }
+}
+
+impl tokio::io::AsyncWrite for SendStream {
+    fn poll_write(
+        mut self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+        buf: &[u8],
+    ) -> Poll<io::Result<usize>> {
+        // We have to use this syntax because quinn added its own poll_write method.
+        tokio::io::AsyncWrite::poll_write(Pin::new(&mut self.stream), cx, buf)
+    }
+
+    fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<io::Result<()>> {
+        Pin::new(&mut self.stream).poll_flush(cx)
+    }
+
+    fn poll_shutdown(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<io::Result<()>> {
+        Pin::new(&mut self.stream).poll_shutdown(cx)
+    }
+}
+
+impl web_transport_trait::SendStream for SendStream {
+    type Error = WriteError;
+
+    fn set_priority(&mut self, order: u8) {
+        self.stream.set_priority(order.into()).ok();
+    }
+
+    fn reset(&mut self, code: u32) {
+        Self::reset(self, code).ok();
+    }
+
+    fn finish(&mut self) -> Result<(), Self::Error> {
+        Self::finish(self).map_err(|_| WriteError::ClosedStream)?;
+        Ok(())
+    }
+
+    async fn write(&mut self, buf: &[u8]) -> Result<usize, Self::Error> {
+        Self::write(self, buf).await
+    }
+
+    async fn write_buf<B: Buf + Send>(&mut self, buf: &mut B) -> Result<usize, Self::Error> {
+        // This can avoid making a copy when Buf is Bytes, as Quinn will allocate anyway.
+        let size = buf.chunk().len();
+        let chunk = buf.copy_to_bytes(size);
+        self.write_chunk(chunk).await?;
+        Ok(size)
+    }
+
+    async fn write_chunk(&mut self, chunk: Bytes) -> Result<(), Self::Error> {
+        self.write_chunk(chunk).await
+    }
+
+    async fn closed(&mut self) -> Result<(), Self::Error> {
+        self.stopped().await?;
+        Ok(())
+    }
+}