go-libp2p-core/connmgr/presets.go

68 lines
1.7 KiB
Go

package connmgr
import (
"math"
"time"
)
// DecayNone applies no decay.
func DecayNone() DecayFn {
return func(value DecayingValue) (_ int, rm bool) {
return value.Value, false
}
}
// DecayFixed subtracts from by the provided minuend, and deletes the tag when
// first reaching 0 or negative.
func DecayFixed(minuend int) DecayFn {
return func(value DecayingValue) (_ int, rm bool) {
v := value.Value - minuend
return v, v <= 0
}
}
// DecayLinear applies a fractional coefficient to the value of the current tag,
// rounding down via math.Floor. It erases the tag when the result is zero.
func DecayLinear(coef float64) DecayFn {
return func(value DecayingValue) (after int, rm bool) {
v := math.Floor(float64(value.Value) * coef)
return int(v), v <= 0
}
}
// DecayExpireWhenInactive expires a tag after a certain period of no bumps.
func DecayExpireWhenInactive(after time.Duration) DecayFn {
return func(value DecayingValue) (_ int, rm bool) {
rm = value.LastVisit.Sub(time.Now()) >= after
return 0, rm
}
}
// BumpSumUnbounded adds the incoming value to the peer's score.
func BumpSumUnbounded() BumpFn {
return func(value DecayingValue, delta int) (after int) {
return value.Value + delta
}
}
// BumpSumBounded keeps summing the incoming score, keeping it within a
// [min, max] range.
func BumpSumBounded(min, max int) BumpFn {
return func(value DecayingValue, delta int) (after int) {
v := value.Value + delta
if v >= max {
return max
} else if v <= min {
return min
}
return v
}
}
// BumpOverwrite replaces the current value of the tag with the incoming one.
func BumpOverwrite() BumpFn {
return func(value DecayingValue, delta int) (after int) {
return delta
}
}