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- // Package backoff implements backoff algorithms for retrying operations.
- //
- // Use Retry function for retrying operations that may fail.
- // If Retry does not meet your needs,
- // copy/paste the function into your project and modify as you wish.
- //
- // There is also Ticker type similar to time.Ticker.
- // You can use it if you need to work with channels.
- //
- // See Examples section below for usage examples.
- package backoff
- import "time"
- // BackOff is a backoff policy for retrying an operation.
- type BackOff interface {
- // NextBackOff returns the duration to wait before retrying the operation,
- // or backoff. Stop to indicate that no more retries should be made.
- //
- // Example usage:
- //
- // duration := backoff.NextBackOff();
- // if (duration == backoff.Stop) {
- // // Do not retry operation.
- // } else {
- // // Sleep for duration and retry operation.
- // }
- //
- NextBackOff() time.Duration
- // Reset to initial state.
- Reset()
- }
- // Stop indicates that no more retries should be made for use in NextBackOff().
- const Stop time.Duration = -1
- // ZeroBackOff is a fixed backoff policy whose backoff time is always zero,
- // meaning that the operation is retried immediately without waiting, indefinitely.
- type ZeroBackOff struct{}
- func (b *ZeroBackOff) Reset() {}
- func (b *ZeroBackOff) NextBackOff() time.Duration { return 0 }
- // StopBackOff is a fixed backoff policy that always returns backoff.Stop for
- // NextBackOff(), meaning that the operation should never be retried.
- type StopBackOff struct{}
- func (b *StopBackOff) Reset() {}
- func (b *StopBackOff) NextBackOff() time.Duration { return Stop }
- // ConstantBackOff is a backoff policy that always returns the same backoff delay.
- // This is in contrast to an exponential backoff policy,
- // which returns a delay that grows longer as you call NextBackOff() over and over again.
- type ConstantBackOff struct {
- Interval time.Duration
- }
- func (b *ConstantBackOff) Reset() {}
- func (b *ConstantBackOff) NextBackOff() time.Duration { return b.Interval }
- func NewConstantBackOff(d time.Duration) *ConstantBackOff {
- return &ConstantBackOff{Interval: d}
- }
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