# Distributed mutually exclusive locks in MongoDB.
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This crate contains only sync implementation.
If you need a async version, use [`mongo-lock-async`](https://crates.io/crates/mongo-lock-async) crate.

This implementation relies on system time. Ensure that NTP clients on your servers are configured properly.

## Installation
Add this crate to `Cargo.toml`

```toml
[dependencies]
mongo_lock = "0"
```

## Usage
```rust
fn main() {
    let mongo = mongodb::sync::Client::with_uri_str("mongodb://localhost").unwrap();

    // We need to ensure that mongodb collection has a proper index.
    mongo_lock::prepare_database(&mongo).unwrap();

    if let Ok(Some(lock)) =
        mongo_lock::Lock::try_acquire(
            &mongo,
            "my-key",
            std::time::Duration::from_secs(30)
        )
    {
        println!("Lock acquired.");

        // The lock will be released automatically after leaving the scope.
    }
}
```