func DefaultBackoff()

in client.go [523:540]

• 17 lines of code
• 8 McCabe index (conditional complexity)

func DefaultBackoff(min, max time.Duration, attemptNum int, resp *http.Response) time.Duration {
	if resp != nil {
		if resp.StatusCode == http.StatusTooManyRequests || resp.StatusCode == http.StatusServiceUnavailable {
			if s, ok := resp.Header["Retry-After"]; ok {
				if sleep, err := strconv.ParseInt(s[0], 10, 64); err == nil {
					return time.Second * time.Duration(sleep)
				}
			}
		}
	}

	mult := math.Pow(2, float64(attemptNum)) * float64(min)
	sleep := time.Duration(mult)
	if float64(sleep) != mult || sleep > max {
		sleep = max
	}
	return sleep
}