rslock - Redlock for Redis in Rust

This is an implementation of Redlock, the distributed locking mechanism built on top of Redis.

Warning

Before release 1.0.0, this crate will have breaking changes between minor versions. You can upgrade to patch versions without worrying about breaking changes.

Features

• Lock extending
• Async runtime support (async-std and tokio)
• Async redis

Install

cargo add rslock

Note

The default feature of this crate will provide async-std. You may optionally use tokio by supplying the tokio-comp feature flag when installing, but tokio has limitations that will not grant access to some parts of the API (read more here).

Build

cargo build --release

Usage

use std::time::Duration;

use rslock::LockManager;

#[tokio::main]
async fn main() {
    let rl = LockManager::new(vec![
        "redis://127.0.0.1:6380/",
        "redis://127.0.0.1:6381/",
        "redis://127.0.0.1:6382/",
    ]);

    let lock;
    loop {
        // Create the lock
        if let Ok(l) = rl
            .lock("mutex".as_bytes(), Duration::from_millis(1000))
            .await
        {
            lock = l;
            break;
        }
    }

    // Extend the lock
    match rl.extend(&lock, Duration::from_millis(1000)).await {
        Ok(_) => println!("lock extended!"),
        Err(_) => println!("lock couldn't be extended"),
    }

    // Unlock the lock
    rl.unlock(&lock).await;
}

Extending Locks

Extending a lock effectively renews its duration instead of adding extra time to it. For instance, if a 1000ms lock is extended by 1000ms after 500ms pass, it will only last for a total of 1500ms, not 2000ms. This approach is consistent with the Node.js Redlock implementation. See the extend script.

Tests

Run tests with:

cargo test

Examples

Start the redis servers mentioned in the example code:

docker compose -f examples/docker-compose.yml up -d

Run the examples:

cargo run --example basic
cargo run --example shared_lock

Stop the redis servers:

docker compose -f examples/docker-compose.yml down

Contribute

If you find bugs or want to help otherwise, please open an issue.

License

BSD. See LICENSE.