# 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.
```rust
// 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.
```rust
// 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.