depot/third_party/tvl/fun/clbot/backoffutil/backoffutil.go
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GitOrigin-RevId: 3fc1143a04da49a92c3663813c6a0c1e8ccd477f
2020-09-29 23:42:59 -04:00

43 lines
1.4 KiB
Go

// Package backoffutil provides useful utilities for backoff.
package backoffutil
import (
"time"
backoff "github.com/cenkalti/backoff/v4"
)
// ZeroStartingBackOff is a backoff.BackOff that returns "0" as the first Duration after a reset.
// This is useful for constructing loops and just enforcing a backoff duration on every loop, rather than incorporating this logic into the loop directly.
type ZeroStartingBackOff struct {
bo backoff.BackOff
initial bool
}
// NewZeroStartingBackOff creates a new ZeroStartingBackOff.
func NewZeroStartingBackOff(bo backoff.BackOff) *ZeroStartingBackOff {
return &ZeroStartingBackOff{bo: bo, initial: true}
}
// NewDefaultBackOff creates a sensibly configured BackOff that starts at zero.
func NewDefaultBackOff() backoff.BackOff {
ebo := backoff.NewExponentialBackOff()
ebo.MaxElapsedTime = 0
return NewZeroStartingBackOff(ebo)
}
// NextBackOff returns the next back off duration to use.
// For the first call after a call to Reset(), this is 0. For each subsequent duration, the underlying BackOff is consulted.
func (bo *ZeroStartingBackOff) NextBackOff() time.Duration {
if bo.initial == true {
bo.initial = false
return 0
}
return bo.bo.NextBackOff()
}
// Reset resets to the initial state, and also passes a Reset through to the underlying BackOff.
func (bo *ZeroStartingBackOff) Reset() {
bo.initial = true
bo.bo.Reset()
}