13 releases
0.6.0 | Feb 14, 2024 |
---|---|
0.5.2 | Apr 27, 2022 |
0.5.1 | Feb 16, 2022 |
0.5.0 | Jun 6, 2021 |
0.2.1 | Dec 19, 2019 |
#576 in Asynchronous
85 downloads per month
Used in 2 crates
17KB
197 lines
Asynchronous delay queue
A queue of delayed elements backed by futures-timer that can be used with both:
An element is inserted into the DelayQueue
and will be 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
A DelayQueue
and a channel for receiving the expired items is created using the delay_queue
function.
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.
Modification of the delay fails if the delayed item expired in the meantime. In this case an
ErrorAlreadyExpired
will be returned. If modification succeeds the handle will be returned
back to the caller.
Example
use futures_delay_queue::delay_queue;
use std::time::Duration;
#[async_std::main]
async fn main() {
let (delay_queue, rx) = delay_queue::<i32>();
let delay_handle = delay_queue.insert(1, Duration::from_millis(20));
assert!(delay_handle.reset(Duration::from_millis(40)).await.is_ok());
let delay_handle = delay_queue.insert(2, Duration::from_millis(10));
assert!(delay_handle.cancel().await.is_ok());
let delay_handle = delay_queue.insert(3, Duration::from_millis(30));
assert_eq!(rx.receive().await, Some(3));
assert_eq!(rx.receive().await, Some(1));
drop(delay_queue);
assert_eq!(rx.receive().await, None);
}
Dependencies
~5–15MB
~199K SLoC