Initial commit

backend/utils/rand/random.go

@@ -0,0 +1,103 @@
+package rand
+
+import (
+	"math/rand"
+	"strings"
+	"sync"
+	"time"
+)
+
+// 随机对象缓存池(解决自带随机函数全局抢锁问题)
+var randObjectPool = sync.Pool{
+	New: func() interface{} {
+		return rand.New(rand.NewSource(time.Now().UnixNano()))
+	},
+}
+var lowerChar = []rune("abcdefghijklmnopqrstuvwxyz") // strings.Split("abcdefghijklmnopqrstuvwxyz", "")
+var upperChar = []rune("ABCDEFGHIJKLMNOPQRSTUVWXYZ") // strings.Split("ABCDEFGHIJKLMNOPQRSTUVWXYZ", "")
+var numberChar = []rune("0123456789")                // strings.Split("0123456789", "")
+var numberAndChar = append(lowerChar, numberChar...)
+
+func init() {
+	rand.Seed(time.Now().UnixNano())
+}
+
+func Intn[T ~int](n T) T {
+	r := randObjectPool.Get()
+	res := r.(*rand.Rand).Intn(int(n))
+	randObjectPool.Put(r)
+	return T(res)
+}
+
+func IntnCount[T ~int](n T, count int) []T {
+	res := make([]T, count)
+	r := randObjectPool.Get()
+	for i := 0; i < count; i++ {
+		res[i] = T(r.(*rand.Rand).Intn(int(n)))
+	}
+	randObjectPool.Put(r)
+	return res
+}
+
+// Int31n 生成<n的32位整形
+func Int31n[T ~int32](n T) T {
+	r := randObjectPool.Get()
+	res := r.(*rand.Rand).Int31n(int32(n))
+	randObjectPool.Put(r)
+	return T(res)
+}
+
+// Int63n 生成小于n的64位整形
+func Int63n[T ~int64](n T) T {
+	r := randObjectPool.Get()
+	res := r.(*rand.Rand).Int63n(int64(n))
+	randObjectPool.Put(r)
+	return T(res)
+}
+
+// RangeInt 获取范围内的随机整数[min, max)
+func RangeInt[T ~int](min, max T) T {
+	if min > max {
+		min, max = max, min
+	}
+	return Intn(max-min) + min
+}
+
+// RangeString 生成随机字符串
+func RangeString(charSet []rune, n int) string {
+	r := randObjectPool.Get()
+
+	res := strings.Builder{}
+	size := len(charSet)
+	for i := 0; i < n; i++ {
+		res.WriteRune(charSet[r.(*rand.Rand).Intn(size)])
+	}
+	randObjectPool.Put(r)
+	return res.String()
+}
+
+// LowerString 生成随机指定长度小写字母
+func LowerString(n int) string {
+	return RangeString(lowerChar, n)
+}
+
+// UpperString 生成随机指定长度大写字母
+func UpperString(n int) string {
+	return RangeString(upperChar, n)
+}
+
+// NumberString 生成随机指定长度数字字符串
+func NumberString(n int) string {
+	return RangeString(numberChar, n)
+}
+
+// CharNumberString 生成随机指定长度小写字母和数字
+func CharNumberString(n int) string {
+	return RangeString(numberAndChar, n)
+}
+
+// Shuffle 执行指定次数打乱
+func Shuffle(n int, swap func(i, j int)) {
+	r := randObjectPool.Get()
+	r.(*rand.Rand).Shuffle(n, swap)
+}