Function slottle::fibonacci

pub fn fibonacci(base: Duration, max: Duration) -> Interval

Create fibonacci delay interval base on failure count.

Give base as an "unit" duration and max as maximum duration. This function will calculate all available fibonacci sequence items (without first 2 item [0, 1]). The fibonacci sequence size will also be used for the log size of throttle.

Algorithm

// let base = Duration::from_millis(10);    // for example
// let max = Duration::from_millis(60);     // for example

// let max_ratio = 6;                       // == max / base
// let fibo_seq = [1, 2, 3, 5];             // last item always <= max_ratio

// assert_eq!(throttle_log.size(), fibo_seq.len());

let how_long_should_delay = fibo_seq[throttle_log.failure_count()] * base;

Panic

This function will panic when max < base or base == Duration::new(0, 0).