package slack import ( "math/rand" "time" ) // This one was ripped from https://github.com/jpillora/backoff/blob/master/backoff.go // Backoff is a time.Duration counter. It starts at Min. After every // call to Duration() it is multiplied by Factor. It is capped at // Max. It returns to Min on every call to Reset(). Used in // conjunction with the time package. type backoff struct { attempts int // Initial value to scale out Initial time.Duration // Jitter value randomizes an additional delay between 0 and Jitter Jitter time.Duration // Max maximum values of the backoff Max time.Duration } // Returns the current value of the counter and then multiplies it // Factor func (b *backoff) Duration() (dur time.Duration) { // Zero-values are nonsensical, so we use // them to apply defaults if b.Max == 0 { b.Max = 10 * time.Second } if b.Initial == 0 { b.Initial = 100 * time.Millisecond } // calculate this duration if dur = time.Duration(1 << uint(b.attempts)); dur > 0 { dur = dur * b.Initial } else { dur = b.Max } if b.Jitter > 0 { dur = dur + time.Duration(rand.Intn(int(b.Jitter))) } // bump attempts count b.attempts++ return dur } //Resets the current value of the counter back to Min func (b *backoff) Reset() { b.attempts = 0 }