tokio-simplified 0.1.15

A simplified API to interract with tokio sinks and streams
Documentation

A Simplified API to work with Tokio's SplitSink and SplitStream

Motivation

Although Tokio is extremely powerful, somme of its features have been less than intuitive to me. So I built this crate to simplify interracting with Tokio in the ways that I usually do:

  • Writing to an IO without really wanting to do much with what happens then
  • Subscribing one or several callbacks to an IO.

Usage

This API should only be used from inside a Tokio Runtime: it will try to spawn Tokio Tasks and will thus panic if it's not the case.

Standard Usage: Multiple Callbacks

fn tokio_main() {
    let (sink, stream) = LineCodec.framed(tcp_stream).split();
    let io = IoManager::new(sink, stream);
    let writer = io.get_writer();
    io.subscribe(move |frame| {
        writer.write(frame);
    });
    io.subscribe(move |frame| {
        println!("{}", frame);
    })
}

Filtering

You can use filters to have your callbacks only be called when the frame matches some criterion.

fn tokio_main() {
    let (sink, stream) = LineCodec.framed(tcp_stream).split();
    let io = IoManager::with_filter(sink, stream, |frame, writer| {
        if frame.to_ascii_lowercase().contains("hello there") {
            writer.write("General Kenobi!");
            return None;
        }
        Some(frame)
    });
    let writer = io.get_writer();
    io.subscribe(move |frame| {
        writer.write(frame);
    });
    io.subscribe(move |frame| {
        println!("{}", frame);
    })
}

Single Callback Tip

Every time you use subscribe(callback), you endure the cost of one more futures::sync::mpsc::channel, and of one frame.clone() per callback call. It's not a high cost, but if you only have one callback, you can cut these costs by passing your callback as a filter that always returns None.

fn tokio_main() {
    let (sink, stream) = LineCodec.framed(tcp_stream).split();
    let io = IoManager::with_filter(sink, stream, |frame, writer| {
        writer.write(frame);
        None
    });
}