随机数生成优化

rand/rand.go

@@ -3,11 +3,8 @@ package rand
 import (
 	"crypto/rand"
 	"io"
-	"sync"
-	"time"
 
 	"math/big"
-	mrnd "math/rand"
 
 	"github.com/charlienet/go-mixed/bytesconv"
 )
@@ -23,36 +20,33 @@ const (
 	_         = allChars + "/+"
 )
 
-var (
-	randSource mrnd.Source = mrnd.NewSource(time.Now().UnixNano())
-	randLock   sync.Mutex
-)
-
-func init() {
-	mrnd.Seed(time.Now().UnixNano())
-}
+var rng = NewRandGenerator()
 
 type charScope struct {
-	bytes   []byte
-	length  int
-	max     int
-	bits    int
-	mask    int
-	lenFunc func(int) int
+	bytes  []byte
+	length int
+	max    int
+	bits   int
+	mask   int
 }
 
+var (
+	Uppercase = StringScope(uppercase) // 大写字母
+	Lowercase = StringScope(lowercase) // 小写字母
+	Digit     = StringScope(digit)     // 数字
+	Nomix     = StringScope(nomix)     // 不混淆字符
+	Letter    = StringScope(letter)    // 字母
+	Hex       = StringScope(hex)       // 十六进制字符
+	AllChars  = StringScope(allChars)  // 所有字符
+)
+
 func StringScope(str string) *charScope {
-	return strScope(str, nil)
-}
-
-func strScope(str string, f func(int) int) *charScope {
 	len := len(str)
 
 	scope := &charScope{
-		bytes:   bytesconv.StringToBytes(str),
-		length:  len,
-		lenFunc: f,
-		bits:    1,
+		bytes:  bytesconv.StringToBytes(str),
+		length: len,
+		bits:   1,
 	}
 
 	for scope.mask < len {
@@ -65,27 +59,14 @@ func strScope(str string, f func(int) int) *charScope {
 	return scope
 }
 
-var (
-	Uppercase = StringScope(uppercase)                          // 大写字母
-	Lowercase = StringScope(lowercase)                          // 小写字母
-	Digit     = StringScope(digit)                              // 数字
-	Nomix     = StringScope(nomix)                              // 不混淆字符
-	Letter    = StringScope(letter)                             // 字母
-	Hex       = strScope(hex, func(n int) int { return n * 2 }) // 十六进制字符
-	AllChars  = StringScope(allChars)                           // 所有字符
-)
-
 // 生成指定长度的随机字符串
 func (scope *charScope) Generate(length int) string {
 	n := length
-	if scope.lenFunc != nil {
-		n = scope.lenFunc(n)
-	}
-
 	ret := make([]byte, n)
-	for i, cache, remain := n-1, randInt63(), scope.max; i >= 0; {
+
+	for i, cache, remain := n-1, rng.Int63(), scope.max; i >= 0; {
 		if remain == 0 {
-			cache, remain = randInt63(), scope.max
+			cache, remain = rng.Int63(), scope.max
 		}
 
 		if idx := int(cache & int64(scope.mask)); idx < scope.length {
@@ -106,7 +87,7 @@ type scopeConstraint interface {
 
 // 生成区间 n >= 0, n < max
 func Intn[T scopeConstraint](max T) T {
-	n := mrnd.Int63n(int64(max))
+	n := rng.Int63n(int64(max))
 	return T(n) % max
 }
 
@@ -133,17 +114,3 @@ func RandBytes(len int) ([]byte, error) {
 	_, err := io.ReadFull(rand.Reader, r)
 	return r, err
 }
-
-func randInt63() int64 {
-	var v int64
-
-	randLock.Lock()
-	v = randSource.Int63()
-	randLock.Unlock()
-
-	return v
-}
-
-func randNumber2(max int) int {
-	return mrnd.Intn(max)
-}

rand/rand_generator.go

@@ -0,0 +1,102 @@
+package rand
+
+import (
+	mrnd "math/rand"
+	"runtime"
+	"sync/atomic"
+	"time"
+)
+
+var (
+	seed  = time.Now().UnixNano()                 // 随机数种子
+	souce = mrnd.NewSource(time.Now().UnixNano()) // 用于初始化的随机数生成器
+)
+
+type randGenerator struct {
+	source mrnd.Source
+	r      uint32
+}
+
+func NewRandGenerator() *randGenerator {
+	return &randGenerator{
+		source: mrnd.NewSource(getSeed()),
+	}
+}
+
+func getSeed() int64 {
+	seed ^= souce.Int63()
+	return seed
+}
+
+// Int63n returns, as an int64, a non-negative pseudo-random number in the half-open interval [0,n).
+// It panics if n <= 0.
+func (r *randGenerator) Int63n(n int64) int64 {
+	if n <= 0 {
+		panic("invalid argument to Int63n")
+	}
+	if n&(n-1) == 0 { // n is power of two, can mask
+		return r.Int63() & (n - 1)
+	}
+	max := int64((1 << 63) - 1 - (1<<63)%uint64(n))
+	v := r.Int63()
+	for v > max {
+		v = r.Int63()
+	}
+
+	return v % n
+}
+
+func (r *randGenerator) Int31() int32 {
+	return int32(r.Int63() >> 32)
+}
+
+func (r *randGenerator) Int31n(n int32) int32 {
+	if n <= 0 {
+		panic("invalid argument to Int31n")
+	}
+
+	if n&(n-1) == 0 { // n is power of two, can mask
+		return r.Int31() & (n - 1)
+	}
+	max := int32((1 << 31) - 1 - (1<<31)%uint32(n))
+	v := r.Int31()
+	for v > max {
+		v = r.Int31()
+	}
+	return v % n
+}
+
+func (r *randGenerator) Int() int {
+	u := uint(r.Int63())
+	return int(u << 1 >> 1) // clear sign bit if int == int32
+}
+
+// Intn returns, as an int, a non-negative pseudo-random number in the half-open interval [0,n).
+// It panics if n <= 0.
+func (r *randGenerator) Intn(n int) int {
+	if n <= 0 {
+		panic("invalid argument to Intn")
+	}
+	if n <= 1<<31-1 {
+		return int(r.Int31n(int32(n)))
+	}
+	return int(r.Int63n(int64(n)))
+}
+
+func (r *randGenerator) Int63() int64 {
+	r.lock()
+	i := r.source.Int63()
+	r.unlock()
+
+	return i
+}
+
+func (g *randGenerator) lock() {
+	for !atomic.CompareAndSwapUint32(&g.r, 0, 1) {
+		runtime.Gosched()
+	}
+}
+
+func (g *randGenerator) unlock() {
+	atomic.StoreUint32(&g.r, 0)
+}

rand/rand_test.go

@@ -56,6 +56,27 @@ func TestRange(t *testing.T) {
 	}
 }
 
+func TestGenerator(t *testing.T) {
+	g := rand.NewRandGenerator()
+
+	for i := 0; i < 100; i++ {
+		t.Log(g.Int63())
+	}
+}
+
+func TestMutiGenerator(t *testing.T) {
+	set := make(map[int64]struct{}, 1000)
+
+	for i := 0; i < 1000; i++ {
+		r := rand.NewRandGenerator().Int63()
+		if _, ok := set[r]; ok {
+			t.Fatal("生成的随机数重复")
+		}
+
+		set[r] = struct{}{}
+	}
+}
+
 func BenchmarkParallel(b *testing.B) {
 	rand.Hex.Generate(16)
 
@@ -72,15 +93,46 @@ func BenchmarkNoop(b *testing.B) {
 	}
 }
 
-func BenchmarkRandString(b *testing.B) {
+func BenchmarkHexString(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		rand.RandBytes(16)
+	}
+}
 
-	for i := 0; i < 10; i++ {
-		rand.Hex.Generate(10)
+func BenchmarkHexParallel(b *testing.B) {
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			rand.RandBytes(16)
+		}
+	})
+}
+
+func BenchmarkGenerator(b *testing.B) {
+	r := rand.NewRandGenerator()
+	for i := 0; i < b.N; i++ {
+		r.Int63()
+	}
+}
+
+func BenchmarkParallelGenerator(b *testing.B) {
+	r := rand.NewRandGenerator()
+	for i:=0; i<10; i++{
+		go r.Int63()
 	}
 
+	b.ResetTimer()
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			r.Int63()
+		}
+	})
+}
+
+func BenchmarkRandString(b *testing.B) {
+	b.Log(rand.Hex.Generate(16))
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		rand.Hex.Generate(20)
+		rand.Hex.Generate(16)
 	}
 }