随机

rand/rand.go

@@ -0,0 +1,131 @@
+package rand
+
+import (
+	"crypto/rand"
+	"io"
+	"sync"
+	"time"
+
+	mrnd "math/rand"
+
+	"github.com/charlienet/go-mixed/bytesconv"
+)
+
+const (
+	uppercase = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+	lowercase = "abcdefghijklmnopqrstuvwxyz"
+	digit     = "0123456789"
+	nomix     = "BCDFGHJKMPQRTVWXY2346789"
+	letter    = uppercase + lowercase
+	allChars  = uppercase + lowercase + digit
+	hex       = digit + "ABCDEF"
+	_         = allChars + "/+"
+)
+
+type charScope struct {
+	bytes   []byte
+	length  int
+	max     int
+	bits    int
+	mask    int
+	lenFunc func(int) int
+}
+
+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,
+	}
+
+	for scope.mask < len {
+		scope.bits++
+		scope.mask = 1<<scope.bits - 1
+	}
+
+	scope.max = scope.mask / scope.bits
+
+	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
+)
+
+var randSource mrnd.Source = mrnd.NewSource(time.Now().UnixNano())
+var randLock sync.Mutex
+
+// 生成指定长度的随机字符串
+func (scope *charScope) RandString(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; {
+		if remain == 0 {
+			cache, remain = randInt63(), scope.max
+		}
+
+		if idx := int(cache & int64(scope.mask)); idx < scope.length {
+			ret[i] = scope.bytes[idx]
+			i--
+		}
+
+		cache >>= int64(scope.bits)
+		remain--
+	}
+
+	return bytesconv.BytesToString(ret)
+}
+
+// 获取指定范围内的随机数
+func RandInt(min, max int) int {
+	n := randNumber2(max - min)
+	return n + min
+}
+
+// 生成指定范围的随机数
+func RandInt32(min, max int32) int32 {
+	return int32(RandInt(int(min), int(max)))
+}
+
+func RandBytes(len int) ([]byte, error) {
+	r := make([]byte, len)
+	_, err := io.ReadFull(rand.Reader, r)
+	return r, err
+}
+
+// func randNumber(max int64) (int64, error) {
+// 	r, err := rand.Int(rand.Reader, big.NewInt(max+1))
+// 	return r.Int64(), err
+// }
+
+func randInt63() int64 {
+	var v int64
+
+	randLock.Lock()
+	v = randSource.Int63()
+	randLock.Unlock()
+
+	return v
+}
+
+func randNumber2(max int) int {
+	rnd := mrnd.New(randSource)
+	return rnd.Intn(max)
+}