🗂️ interruptible

Stops a future producer or stream from producing values when interrupted.

For a future that returns either Result<T, ()> or ControlFlow<T, ()>, calling fut.interruptible_*(tx) causes the returned value to be Err(()) or Break(T) if an interruption signal is received while that future is executing.

This means the future is progressed to completion, but the return value signals the producer to stop yielding futures.

For a stream, when the interrupt signal is received, the current future is run to completion, but the stream is not polled for the next item.

Usage

Add the following to Cargo.toml

interruptible = "0.2.1"

# Enables `InterruptibleStreamExt`
interruptible = { version = "0.2.1", features = ["stream"] }

# Enables:
#
# * `InterruptibleFutureExt::{interruptible_control_ctrl_c, interruptible_result_ctrl_c}`
# * `InterruptibleStreamExt::interruptible_ctrl_c` if the `"stream"` feature is also enabled.
interruptible = { version = "0.2.1", features = ["ctrl_c"] }

Examples

Future<Output = ControlFlow<B, C>>

use std::ops::ControlFlow;

use futures::FutureExt;
use tokio::{
    join,
    sync::{mpsc, oneshot},
};

use interruptible::{InterruptSignal, InterruptibleFutureExt};

#[tokio::main(flavor = "current_thread")]
async fn main() {
    let (interrupt_tx, mut interrupt_rx) = mpsc::channel::<InterruptSignal>(16);
    let (ready_tx, ready_rx) = oneshot::channel::<()>();

    let interruptible_control = async {
        let () = ready_rx.await.expect("Expected to be notified to start.");
        ControlFlow::Continue(())
    }
    .boxed()
    .interruptible_control(&mut interrupt_rx);

    let interrupter = async move {
        interrupt_tx
            .send(InterruptSignal)
            .await
            .expect("Expected to send `InterruptSignal`.");
        ready_tx
            .send(())
            .expect("Expected to notify sleep to start.");
    };

    let (control_flow, ()) = join!(interruptible_control, interrupter);

    assert_eq!(ControlFlow::Break(InterruptSignal), control_flow);
}

InterruptibleStreamExt with features = ["stream"]

Stops a stream from producing values when an interrupt signal is received.

See the interrupt_strategy module for different ways the stream interruption can be handled.

#[cfg(not(feature = "stream"))]
fn main() {}

#[cfg(feature = "stream")]
#[tokio::main(flavor = "current_thread")]
async fn main() {

use futures::{stream, StreamExt};
use tokio::sync::mpsc;

use interruptible::{
    InterruptibleStreamExt, InterruptSignal, Interruptibility, PollOutcome,
};

    let (interrupt_tx, mut interrupt_rx) = mpsc::channel::<InterruptSignal>(16);

    let mut interruptible_stream =
        stream::unfold(0u32, move |n| async move { Some((n, n + 1)) })
            .interruptible(interrupt_rx.into());

    interrupt_tx
        .send(InterruptSignal)
        .await
        .expect("Expected to send `InterruptSignal`.");

    assert_eq!(
        Some(PollOutcome::Interrupted(None)),
        interruptible_stream.next().await
    );
    assert_eq!(None, interruptible_stream.next().await);
}

License

Licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or https://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.