Function relay_until_eof

crates/openshell-supervisor-network/src/l7/rest.rs:2318–2341

Relay all bytes from reader to writer until EOF or idle timeout. Used for HTTP responses with no explicit framing (no Content-Length, no Transfer-Encoding) where the body is delimited by connection close. An idle timeout prevents blocking when servers keep the TCP connection alive longer than expected (e.g. CDN keep-alive timers).

(reader: &mut R, writer: &mut W)

/// An idle timeout prevents blocking when servers keep the TCP connection
/// alive longer than expected (e.g. CDN keep-alive timers).
async fn relay_until_eof<R, W>(reader: &mut R, writer: &mut W) -> Result<()>
where
    R: AsyncRead + Unpin,
    W: AsyncWrite + Unpin,
{
    let mut buf = [0u8; RELAY_BUF_SIZE];
    loop {
        match tokio::time::timeout(RELAY_EOF_IDLE_TIMEOUT, reader.read(&mut buf)).await {
            Ok(Ok(0)) => return Ok(()),
            Ok(Ok(n)) => {
                writer.write_all(&buf[..n]).await.into_diagnostic()?;
                writer.flush().await.into_diagnostic()?;
            }
            Ok(Err(e)) => return Err(miette::miette!("{e}")),
            Err(_) => {
                debug!(
                    "relay_until_eof idle timeout after {:?}",
                    RELAY_EOF_IDLE_TIMEOUT
                );
                return Ok(());
            }
        }
    }
}

/// Relay all bytes from reader to writer until EOF without an idle timeout.
///