Burster ⏩

Burster is a high quality and lightweigh crate providing stack allocated rate limiters with minimal dependencies. Guaranteed to work on no_std targets, but also comfortable on standard targets.

Supported rate limiter types

• Token bucket
• Fixed window
• Sliding window
• ..something else? Make a request or open a PR :)

Usage

On std targets usage is simple. Install the crate with default features enabled and you'll get access to straightforward utility functions for instantiating limiters.

// Instantiate a token bucket that allowes an average consume
// rate of 100 tokens per second and with bucket_size = 10
let mut bucket = burster::token_bucket(100, 10);

// Use the bucket:
if bucket.try_consume_one().is_ok() {
    // All good, enough tokens left
} else {
    // Not enough tokens for this consume
}

On no_std targets you'll have to install the crate with default features disabled and provide bindings to your platforms clock functionality in the form of a closure that returns the current timestamp as u64 milliseconds.

// Instantiate a token bucket that allowes an average consume
// rate of 100 tokens per second and with bucket_size = 10
let mut bucket = burster::TokenBucket::new_with_time_provider(100, 10, || {
    // Return current timestamp
    my_clock_fn()
});

The time provider closure should return a monotonous nondecreasing timestamp, which does not have to be bound to a specific epoch. It can, for example, simply be a timestamp from the last system boot.