Xray-core/common/dice/dice.go

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2020-11-25 13:01:53 +02:00
// Package dice contains common functions to generate random number.
// It also initialize math/rand with the time in seconds at launch time.
package dice // import "github.com/xtls/xray-core/v1/common/dice"
import (
"math/rand"
"time"
)
// Roll returns a non-negative number between 0 (inclusive) and n (exclusive).
func Roll(n int) int {
if n == 1 {
return 0
}
return rand.Intn(n)
}
// Roll returns a non-negative number between 0 (inclusive) and n (exclusive).
func RollDeterministic(n int, seed int64) int {
if n == 1 {
return 0
}
return rand.New(rand.NewSource(seed)).Intn(n)
}
// RollUint16 returns a random uint16 value.
func RollUint16() uint16 {
return uint16(rand.Int63() >> 47)
}
func RollUint64() uint64 {
return rand.Uint64()
}
func NewDeterministicDice(seed int64) *DeterministicDice {
return &DeterministicDice{rand.New(rand.NewSource(seed))}
}
type DeterministicDice struct {
*rand.Rand
}
func (dd *DeterministicDice) Roll(n int) int {
if n == 1 {
return 0
}
return dd.Intn(n)
}
func init() {
rand.Seed(time.Now().Unix())
}