status-go/vendor/github.com/raulk/go-watchdog/watermarks.go

43 lines
1.4 KiB
Go

package watchdog
// NewWatermarkPolicy creates a watchdog policy that schedules GC at concrete
// watermarks. When queried, it will determine the next trigger point based
// on the current utilisation. If the last watermark is surpassed,
// the policy will be disarmed. It is recommended to set an extreme watermark
// as the last element (e.g. 0.99) to prevent the policy from disarming too soon.
func NewWatermarkPolicy(watermarks ...float64) PolicyCtor {
return func(limit uint64) (Policy, error) {
p := new(watermarkPolicy)
p.limit = limit
p.thresholds = make([]uint64, 0, len(watermarks))
for _, m := range watermarks {
p.thresholds = append(p.thresholds, uint64(float64(limit)*m))
}
Logger.Infof("initialized watermark watchdog policy; watermarks: %v; thresholds: %v", p.watermarks, p.thresholds)
return p, nil
}
}
type watermarkPolicy struct {
// watermarks are the percentual amounts of limit.
watermarks []float64
// thresholds are the absolute trigger points of this policy.
thresholds []uint64
limit uint64
}
var _ Policy = (*watermarkPolicy)(nil)
func (w *watermarkPolicy) Evaluate(_ UtilizationType, used uint64) (next uint64) {
Logger.Debugf("watermark policy: evaluating; utilization: %d/%d (used/limit)", used, w.limit)
var i int
for ; i < len(w.thresholds); i++ {
t := w.thresholds[i]
if used < t {
return t
}
}
// we reached the maximum threshold, so we disable this policy.
return PolicyTempDisabled
}