FYI. msquic-async crate

[masa-koz]

I created msquic-async MsQuic based quic library that supports async operation for rust.
https://github.com/masa-koz/msquic-async-rs

Using this crate, you can use MsQuic as below.

    let mut stream = conn
        .open_outbound_stream(msquic_async::StreamType::Bidirectional, false)
        .await?;
    stream.write_all("hello".as_bytes()).await?;
    let mut buf = [0u8; 1024];
    let len = stream.read(&mut buf).await?;
    info!("received: {}", String::from_utf8_lossy(&buf[0..len]));

Regards,

[nibanks]

I haven't looked at the details of the crate. How do you handle buffers on the send and receive path? Do you use send buffering (i.e. copies data)? On the receive path, do you return pending or do you copy the buffers somewhere?

[masa-koz]

On the send path, Stream::poll_write() copies data. But Stream::zerocopy_write() accepts a bytes::Bytes and pass it to MsQuic directly.
On the recieve path, msquic-async always stores the buffer and returns QUIC_STATUS_PENDING in the handler of STREAM_EVENT_RECEIVE. Stream::poll_read() takes the buffer and copies the data into user's buffer. Stream::poll_read_chunk() takes the buffer and return it. The buffer, StreamRecvBuffer implements bytes::Buf, so user can process it.

[masa-koz]

I've published this in crates.io.
https://crates.io/crates/msquic-async

[masa-koz]

I published h3-msquic-async to use MsQuic with h3.