Method newRetryTimer

retry.go:52–95

newRetryTimer creates a timer with exponentially increasing delays until the maximum retry attempts are reached.

(ctx context.Context, maxRetry int, baseSleep, maxSleep time.Duration, jitter float64)

// newRetryTimer creates a timer with exponentially increasing
// delays until the maximum retry attempts are reached.
func (c *Client) newRetryTimer(ctx context.Context, maxRetry int, baseSleep, maxSleep time.Duration, jitter float64) iter.Seq[int] {
	// computes the exponential backoff duration according to
	// https://www.awsarchitectureblog.com/2015/03/backoff.html
	exponentialBackoffWait := func(attempt int) time.Duration {
		// normalize jitter to the range [0, 1.0]
		if jitter < NoJitter {
			jitter = NoJitter
		}
		if jitter > MaxJitter {
			jitter = MaxJitter
		}

		// sleep = random_between(0, min(maxSleep, base * 2 ** attempt))
		sleep := baseSleep * time.Duration(1<<uint(attempt))
		if sleep > maxSleep {
			sleep = maxSleep
		}
		if math.Abs(jitter-NoJitter) > 1e-9 {
			sleep -= time.Duration(c.random.Float64() * float64(sleep) * jitter)
		}
		return sleep
	}

	return func(yield func(int) bool) {
		// if context is already canceled, skip yield
		select {
		case <-ctx.Done():
			return
		default:
		}

		for i := range maxRetry {
			if !yield(i) {
				return
			}

			select {
			case <-time.After(exponentialBackoffWait(i)):
			case <-ctx.Done():
				return
			}
		}
	}
}

// List of AWS S3 error codes which are retryable.
var retryableS3Codes = set.CreateStringSet(