feat: Seeder

rand/seeder.go

@@ -0,0 +1,99 @@
+package rand
+
+import (
+	cryptoRand "crypto/rand"
+	"encoding/binary"
+	"golang.org/x/exp/rand"
+	"hash/maphash"
+	mathRand "math/rand"
+	"runtime"
+	"time"
+)
+
+type SeedType string
+
+const (
+	UnixNanoSeed     SeedType = "UnixNano"
+	MapHashSeed      SeedType = "MapHash"
+	CryptoRandSeed   SeedType = "CryptoRand"
+	RandomStringSeed SeedType = "RandomString"
+)
+
+type Seeder struct {
+	seedType SeedType
+}
+
+func NewSeeder(seedType SeedType) *Seeder {
+	return &Seeder{
+		seedType: seedType,
+	}
+}
+
+func (r *Seeder) UnixNano() int64 {
+	// 获取当前时间戳
+	timestamp := time.Now().UnixNano()
+
+	// 生成一个随机数
+	var randomBytes [8]byte
+	_, err := rand.Read(randomBytes[:])
+	if err != nil {
+		panic("failed to generate random bytes")
+	}
+	randomPart := int64(binary.LittleEndian.Uint64(randomBytes[:]))
+
+	// 获取 Goroutine ID（或其他唯一标识）
+	goroutineID := int64(runtime.NumGoroutine())
+
+	// 结合时间戳、随机数和 Goroutine ID
+	seed := timestamp ^ randomPart ^ goroutineID
+
+	return seed
+}
+
+func (r *Seeder) MapHash() int64 {
+	return int64(new(maphash.Hash).Sum64())
+}
+
+func (r *Seeder) CryptoRand() int64 {
+	var b [8]byte
+	_, err := cryptoRand.Read(b[:])
+	if err != nil {
+		panic("cannot seed math/rand package with cryptographically secure random number generator")
+	}
+	seed := int64(binary.LittleEndian.Uint64(b[:]))
+	return seed
+}
+
+var Alpha = "abcdefghijkmnpqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ23456789"
+
+func (r *Seeder) RandomString() int64 {
+	const size = 8
+	buf := make([]byte, size)
+	for i := 0; i < size; i++ {
+		buf[i] = Alpha[mathRand.Intn(len(Alpha))]
+	}
+	seed := int64(binary.LittleEndian.Uint64(buf[:]))
+
+	return seed
+}
+
+func (r *Seeder) Seed() int64 {
+	switch r.seedType {
+	default:
+		fallthrough
+	case UnixNanoSeed:
+		return r.UnixNano()
+	case MapHashSeed:
+		return r.MapHash()
+	case CryptoRandSeed:
+		return r.CryptoRand()
+	case RandomStringSeed:
+		return r.RandomString()
+	}
+}
+
+// Seed generates a seed based on the specified SeedType.
+func Seed(seedType SeedType) int64 {
+	randomizer := NewSeeder(seedType)
+	return randomizer.Seed()
+}