linked-futures

Overview

This crate provides the way to "link" futures into a single block, which stops executing once any of these futures complete.

Under the hood, it uses FuturesUnordered to execute multiple futures efficiently. In order to avoid boxing, custom one-of type from one-of-futures crate is generated for each link_futures block.

License: MIT

Usage

Add this to your Cargo.toml: toml [dependencies] linked-futures = "0.1"

Example

```rust use std::time::{Duration, Instant};

use futures::{pinmut, SinkExt, StreamExt}; use futures::channel::mpsc; use futures::executor::blockon; use tokio::clock; use tokio::timer::{delay, Interval};

use linkedfutures::{linkfutures, linked_block};

linked_block!(PeriodicStoppableSender, PeriodicStoppableSenderFutureIdentifier; Forwarder, Reader, Generator, Stop );

[tokio::main]

async fn main() { let (mut tx1, mut rx1) = mpsc::channel::(1); let (mut tx2, mut rx2) = mpsc::channel::(1);

let mut interval = Interval::new(clock::now(), Duration::from_millis(100));

let generator = async {
    while let Some(instant) = interval.next().await {
        tx1.send(instant).await;
    }
};
let forwarder = async {
    while let Some(instant) = rx1.next().await {
        tx2.send(instant).await;
    }
};
let reader = async {
    while let Some(instant) = rx2.next().await {
        println!("instant: {:?}", instant);
    }
};
let stop = async { 
    delay(clock::now() + Duration::from_secs(1)).await; 
};
let linked = link_futures!(
   PeriodicStoppableSender, 
   PeriodicStoppableSenderFutureIdentifier;
   Generator => generator,
   Forwarder => forwarder,
   Reader => reader,
   Stop => stop
);
block_on(async {
    pin_mut!(linked);
    let (completed_future_identifier, _) = linked.await;
    match completed_future_identifier {
        PeriodicStoppableSenderFutureIdentifier::Stop => 
            println!("linked block stopped normally"),
        n => 
            panic!("linked block unexpectedly terminated by future: {:?}", n),
    }
});

} ```