Xray-core/common/dice/dice.go
A1lo a994bf8b04
chore: fix some errors detected by staticcheck (#3089)
* chore: fix some errors detected by staticcheck

* feat: remove `rand.Seed()` usage for possibly using "fastrand64" runtime to avoid locking

ref: https://pkg.go.dev/math/rand#Seed
2024-03-03 10:52:22 -05:00

48 lines
1,013 B
Go

// 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/common/dice"
import (
"math/rand"
)
// 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)
}