Support async trait such as `tokio::io::AsyncRead`

[iamazy]

Hi, I hava try this crate but got some errors because tokio-uring doesn't implement some async trait for tokio_uring::net::TcpStream etc.

The one of the error messages is as follows:

error[E0277]: the trait bound `tokio_uring::net::TcpStream: tokio::io::AsyncRead` is not satisfied
   --> src/connection.rs:276:66
    |
276 |                     .map(|stream| tokio_util::codec::Framed::new(stream, codec))?;
    |                                   ------------------------------ ^^^^^^ the trait `tokio::io::AsyncRead` is not implemented for `tokio_uring::net::TcpStream`
    |                                   |
    |                                   required by a bound introduced by this call
    |
    = help: the following other types implement trait `tokio::io::AsyncRead`:
              &[u8]
              &mut T
              Box<T>
              BufStream<RW>
              DuplexStream
              Pin<P>
              std::io::Cursor<T>
              tokio::fs::File
            and 17 others
note: required by a bound in `tokio_util::codec::Framed::<T, U>::new`

Is there any plan to support these traits?

[Noah Kennedy]

There are plans to support AsyncRead/Write via IORING_OP_POLL_ADD, which allows us to do readiness-based IO with io_uring, but those implementations wouldn't have the efficiency benefits of io_uring, and would perform about the same as using epoll.

Unfortunately, AsyncRead/Write are pretty strongly tied to the readiness-based model of epoll and kqueue, and aren't a good fit for io_uring. A set of owned buffer traits is probably needed instead.

[Kai Mast]

Is the plan then to have a separate tokio-uring-util crate that provides codecs that work with tokio-uring?