Cancel stream with status code?

[gitmalong]

Hi! How can I cancel a stream on server side with returning a certain status code? Is that even supported?

[dkozma]

Wanted to follow up with an actual implementation example (and also follow up since it has been over a year since this was initially posted).

I'm struggling a bit on trying to figure out how I can send an error when something happens in a task - see the following example:

async fn bidi_handler(
    &self,
    request: Request<Streaming<MyRequest>>
) -> Result<Response<Self::MyResponseStream>, Status> {
    let mut request_stream = request.into_inner();
    let (tx, mut rx) = mpsc::channel(128);

    let handle = tokio::spawn(async move {
        while Some(something) = request_stream.next().await {
            // Do something based on request stream
            let result = process(something);
            tx.send(result).await.expect("Could not send to channel");

            // Test panic to show issue
            panic!("Error in spawned task");
        }
    })

    // I can't `await` here to get the error without spawning another task since it will block the return.
    //
    // handle.await.unwrap_or(|err| tx.send(Err(
    //     Status::new(Code::Internal, err.to_string());
    // ));

    Ok(Response::new(ReceiverStream::new(rx)))
}

Not sure if there is a way around this or another pattern that can be used.