9 releases (4 breaking)

0.5.0 Feb 27, 2023
0.4.2 Feb 19, 2023
0.3.2 Jan 10, 2023
0.2.0 Jan 9, 2023
0.1.0 Jan 9, 2023

#1953 in Web programming

MIT license

299 lines


A library to asynchronously generate Snowflake IDs.

What is a snowflake

Snowflakes were developed by twitter for creating time sortable ids, which are able to be quickly generated without syncronisation even in distributed compute clusters.

Snowflakes have the following layout:

Snowflake ID layout


First you need to include dependencies. These are the recommended features. Tokio may be slimmed down by enabling individual features instead of full.

hexafreeze = "0.5"
tokio = {version = "1", features = ["full"]}

Generator is the interface for the generation of snowflakes. Snowflakes require an epoch, basically the start time of the Snowflake, it needs to be in the past and be less than ~ 69 years ago. DEFAULT_EPOCH should be fine for most applications until 2079. It is thread-safe, therefore you do not need a Mutex to contain it. It is recommend to use the same generator in all places in a rust application, something like once_cell may be useful for this.

use hexafreeze::Generator;
use hexafreeze::DEFAULT_EPOCH;

async fn main() {
    // If your system is not distributed using `0` as the `node_id` is perfectly fine.
    // The `DEFAULT_EPOCH` always needs to be dereferenced.
    let gen = Generator::new(0, *DEFAULT_EPOCH).unwrap();

    // The `generate` function is async and non-blocking.
    let id: i64 = gen.generate().await.unwrap();


  • Unlike Twitter's reference implementation, the sequence does not get reset every millisecond.


~129K SLoC