Snowflake ID Generator (Rust)

A compact, easy-to-use Rust implementation of a Snowflake-style 64-bit ID generator. This crate provides both single-threaded and multi-threaded generators, and supports synchronous (blocking) and asynchronous (non-blocking) usage patterns.

Key goals:

Small and focused API
Correct bit layout and overflow handling
Usable from sync and async contexts

Features

64-bit unique IDs composed of timestamp, worker ID and a per-millisecond sequence.
Configurable custom epoch.
Sync and async generators.
Single-threaded and multi-threaded implementations.

Examples

Example (async, multi-threaded):

use snowflake_id_generator::multi_thread::async_generator::SnowflakeGenerator;

#[tokio::main]
async fn main() {
    // worker_id, custom_epoch_ms
    let generator = SnowflakeGenerator::new(0, 1).expect("valid generator");
    let id = generator.generate_id().await;
    println!("Generated ID: {}", id);
}

Example (sync, single-threaded):

use snowflake_id_generator::single_thread::sync_generator::SnowflakeGenerator;

fn main() {
    let mut generator = SnowflakeGenerator::new(0, 1).expect("valid generator");
    let id = generator.generate_id().expect("generate id");
    println!("Generated ID: {}", id);
}

Project Structure

See the src/ modules for more generators and utilities:

src/common.rs — core SnowflakeState, bit layout and helpers
src/single_thread.rs — single-threaded sync/async generators
src/multi_thread.rs — multi-threaded sync/async generators

ID Layout

The 64-bit ID layout used by this generator (from most-significant bit to least):

1 bit: unused/sign (always 0)
41 bits: timestamp in milliseconds since the custom epoch
10 bits: worker ID (0..1023)
12 bits: per-millisecond sequence (0..4095)

This layout allows unique IDs across workers and within the same millisecond.

Errors

Common error conditions provided by the crate include:

Worker ID out of allowed range (0..1023).
Epoch set in the future.
System clock issues that would cause timestamps earlier than the epoch.

Refer to the crate's error types in src/common.rs for exact variants and Display messages.

Contributing

Contributions are welcome. Please:

Open an issue to discuss large changes.
Submit small, focused pull requests.
Add tests for bug fixes and new functionality.

License

This project is licensed under the terms in the repository's LICENSE file.

snowflake-id-generator 0.2.0