#rate #rate-limiting #limiter #gcra

gcr

A fast, simple, and small Generic Cell Rate (GCR) algorithm implementation with zero dependencies

4 releases

new 0.1.3 Oct 29, 2024
0.1.2 Oct 23, 2024
0.1.1 Oct 22, 2024
0.1.0 Oct 22, 2024

#481 in Algorithms

Download history 2/week @ 2024-07-29 360/week @ 2024-10-21

360 downloads per month

MIT license

15KB
192 lines

Generic Cell Rate (GCR) algorithm

crates.io docs.rs

A fast, simple, and small Generic Cell Rate (GCR) algorithm implementation with zero dependencies that allows for dynamic rate adjustment.

Usage

use gcr::Gcr;

let mut rate = Gcr::new(10, Duration::from_secs(1), Some(30)).unwrap();
    // 10 units allowed every second with a max burst of 30 units at once

rate.request(20).unwrap(); // Leftover capacity is now 10
rate.request(20).unwrap_err(); // Returns `DeniedFor(1 second)`

Rate adjustment

Gcr::adjust can be used to change the rate of the limiter while preserving the current capacity.

It accepts the same parameters as Gcr::new.

rate.adjust(20, Duration::from_secs(1), Some(30)).unwrap();
    // 20 units allowed every second with a max burst of 30 units at once

Capacity

Gcr::capacity can be used to get the current capacity of the rate limiter without making a request.

rate.capacity();

No runtime deps