fure

A crate for retrying futures.

[Policy] trait will help you define different retry policies.

Some builtin policies can be found in [policies] module.

By default this create uses tokio timers for [crate::policies::interval] and [crate::policies::backoff] policies, but async-std is also available as feature async-std.

Examples.

Interval retry.

Starts with sending a request, setting up a 1 second timer, and waits for either of them.

If the timer completes first (it means that the request didn't complete in 1 second) one more request fires.

If the request completes first and it has an [Ok] response it is returned, if request has an [Err] response, timer resets and a new request fires.

At most 4 requests will be fired.

When one of runninng requests completes with an [Ok] result it will be returned.

use fure::policies::{interval, attempts};
use std::time::Duration;

let get_body = || async {
    reqwest::get("https://www.rust-lang.org")
        .await?
        .text()
        .await
};
let policy = attempts(interval(Duration::from_secs(1)), 3);
let body = fure::retry(get_body, policy).await?;
println!("body = {}", body);

Sequential retry with backoff.

Retries attempts requests with an exponential backoff and a jitter.

use fure::{policies::{backoff, cond}, backoff::{exponential, jitter}};
use std::time::Duration;

let get_body = || async {
    reqwest::get("https://www.rust-lang.org")
        .await?
        .text()
        .await
};
let exp_backoff = exponential(Duration::from_secs(1), 2, Some(Duration::from_secs(10)))
    .map(jitter);
let policy = cond(backoff(exp_backoff), |result| !matches!(result, Some(Ok(_))));
let body = fure::retry(get_body, policy).await?;
println!("body = {}", body);

License: MIT