Crate futures_delay_queue

A queue of delayed elements running backed by async-std and futures-timer.

Once an element is inserted into the DelayQueue, it is yielded once the specified deadline has been reached.

The delayed items can be consumed through a channel returned at creation.

Implementation

The delays are spawned and a timeout races against a reset channel that can be triggered with the DelayHandle. If the timeout occurs before cancelation or a reset the item is yielded through the receiver channel.

Usage

Elements are inserted into DelayQueue using the insert or insert_at methods. A deadline is provided with the item and a DelayHandle is returned. The delay handle is used to remove the entry.

The delays can be configured with the [reset_at or the [reset] method or canceled by calling the cancel method. Dropping the handle will not cancel the delay.

Example

use futures_delay_queue::delay_queue;
use std::time::Duration;

#[async_std::main]
async fn main() {
    let (delay_queue, rx) = delay_queue::<i32>(3);

    let delay_handle = delay_queue.insert(1, Duration::from_millis(20));
    delay_handle.reset(Duration::from_millis(40)).await;
    let delay_handle = delay_queue.insert(2, Duration::from_millis(10));
    delay_handle.cancel().await;
    let delay_handle = delay_queue.insert(3, Duration::from_millis(30));

    assert_eq!(rx.recv().await, Some(3));
    assert_eq!(rx.recv().await, Some(1));

    drop(delay_queue);
    assert_eq!(rx.recv().await, None);
}

Structs

DelayHandle	A handle to cancel the corresponding delay of an item in DelayQueue.
DelayQueue	A queue for managing delayed items.

Functions

delay_queue

Creates a delay queue and a multi consumer channel for receiving expired items.