From 6efb6dfac8c89173e0474bbcb86c373ccadde680 Mon Sep 17 00:00:00 2001
From: charlie <3140647@qq.com>
Date: Thu, 31 Mar 2022 11:41:41 +0800
Subject: [PATCH] =?UTF-8?q?=E9=9A=8F=E6=9C=BA=E6=95=B0=E7=94=9F=E6=88=90?=
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---
 rand/rand.go      | 34 +++++++++++++++++------
 rand/rand_test.go | 69 ++++++++++++++++++++++++++++++++++-------------
 2 files changed, 77 insertions(+), 26 deletions(-)

diff --git a/rand/rand.go b/rand/rand.go
index e079b12..5166b94 100644
--- a/rand/rand.go
+++ b/rand/rand.go
@@ -6,6 +6,7 @@ import (
 	"sync"
 	"time"
 
+	"math/big"
 	mrnd "math/rand"
 
 	"github.com/charlienet/go-mixed/bytesconv"
@@ -75,7 +76,7 @@ var (
 )
 
 // 生成指定长度的随机字符串
-func (scope *charScope) RandString(length int) string {
+func (scope *charScope) Generate(length int) string {
 	n := length
 	if scope.lenFunc != nil {
 		n = scope.lenFunc(n)
@@ -99,15 +100,32 @@ func (scope *charScope) RandString(length int) string {
 	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
+type scopeConstraint interface {
+	~int | ~int32 | ~int64
 }
 
-// 生成指定范围的随机数
-func RandInt32(min, max int32) int32 {
-	return int32(RandInt(int(min), int(max)))
+// 生成区间 n >= 0, n < max
+func Intn[T scopeConstraint](max T) T {
+	n := mrnd.Int63n(int64(max))
+	return T(n) % max
+}
+
+// 生成区间 n >= min, n < max
+func IntRange[T scopeConstraint](min, max T) T {
+	n := Intn(max - min)
+	return T(n + min)
+}
+
+func CryptoRange[T scopeConstraint](min, max T) T {
+	n := CryptoIntn(max - min)
+	return min + n
+}
+
+func CryptoIntn[T ~int | ~int32 | ~int64](max T) T {
+	b := big.NewInt(int64(max))
+	n, _ := rand.Int(rand.Reader, b)
+
+	return T(n.Int64())
 }
 
 func RandBytes(len int) ([]byte, error) {
diff --git a/rand/rand_test.go b/rand/rand_test.go
index 91bd3d3..2e2a9fe 100644
--- a/rand/rand_test.go
+++ b/rand/rand_test.go
@@ -11,7 +11,7 @@ import (
 )
 
 func TestRandString(t *testing.T) {
-	t.Log(rand.AllChars.RandString(20))
+	t.Log(rand.AllChars.Generate(20))
 
 	// b, err := rand.RandBytes(32)
 	// t.Log(err)
@@ -19,7 +19,7 @@ func TestRandString(t *testing.T) {
 }
 
 func TestRandHex(t *testing.T) {
-	h := rand.Hex.RandString(8)
+	h := rand.Hex.Generate(8)
 	t.Log(h)
 }
 
@@ -27,43 +27,61 @@ func TestRandMax(t *testing.T) {
 	mrnd.Seed(time.Now().UnixNano())
 }
 
+func TestCryptRand(t *testing.T) {
+	t.Log(rand.CryptoIntn(56545))
+}
+
+func TestGenericsInterger(t *testing.T) {
+	var max int32 = 55
+
+	for i := 0; i < 1000; i++ {
+		if rand.Intn(max) >= max {
+			t.Fatal("生成的值大于最大值:", max)
+		}
+	}
+}
+
+func TestRange(t *testing.T) {
+	min := 20
+	max := 200000
+	for i := 0; i < 100000000; i++ {
+		n := rand.IntRange(min, max)
+		if n < min {
+			t.Fatal("生成的值小于最小值:", min, n)
+		}
+
+		if n >= max {
+			t.Fatal("生成的值大于最大值:", min, n)
+		}
+	}
+}
+
 func BenchmarkParallel(b *testing.B) {
-	rand.Hex.RandString(16)
+	rand.Hex.Generate(16)
 
 	b.RunParallel(func(pb *testing.PB) {
 		for pb.Next() {
-			rand.Hex.RandString(16)
+			rand.Hex.Generate(16)
 		}
 	})
 }
 
 func BenchmarkNoop(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		rand.AllChars.RandString(16)
+		rand.AllChars.Generate(16)
 	}
 }
 
 func BenchmarkRandString(b *testing.B) {
 
 	for i := 0; i < 10; i++ {
-		rand.Hex.RandString(10)
+		rand.Hex.Generate(10)
 	}
 
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		rand.Hex.RandString(20)
+		rand.Hex.Generate(20)
 	}
-
-	// b.Run("randString", func(b *testing.B) {
-
-	// 	for i := 0; i < b.N; i++ {
-	// 		rand.Hex.RandString(256)
-	// 	}
-	// })
-
-	// for i := 0; i < b.N; i++ {
-	// 	rand.RandBytes(16)
-	// }
 }
 
 func BenchmarkString(b *testing.B) {
@@ -116,3 +134,18 @@ func BenchmarkConcatString(b *testing.B) {
 		}
 	})
 }
+
+func BenchmarkRand(b *testing.B) {
+	b.Run("math/rand", func(b *testing.B) {
+		for i := 0; i < b.N; i++ {
+			rand.Intn(100)
+		}
+	})
+
+	b.Run("crypto/rand", func(b *testing.B) {
+		for i := 0; i < b.N; i++ {
+			rand.CryptoIntn(100)
+		}
+	})
+
+}