改进grand随机数生成设计，底层使用crypto/rand+缓冲区实现高速的随机数生成；gtime模块增加FuncCost函数执行耗时计算

g/net/ghttp/ghttp_server_session.go

@@ -26,7 +26,7 @@ type Session struct {
     server *Server                  // 所属Server
 }
 
-// 生成一个唯一的sessionid字符串
+// 生成一个唯一的sessionid字符串，长度16
 func makeSessionId() string {
     return strings.ToUpper(strconv.FormatInt(gtime.Nanosecond(), 32) + grand.RandStr(3))
 }

g/os/gtime/gtime.go

@@ -306,4 +306,11 @@ func ParseTimeFromContent(content string, format...string) *Time {
         }
     }
     return nil
+}
+
+// 计算函数f执行的时间，单位纳秒
+func FuncCost(f func()) int64 {
+    t := Nanosecond()
+    f()
+    return Nanosecond() - t
 }

g/util/gconv/gconv.go

@@ -15,7 +15,7 @@ import (
     "strings"
 )
 
-// 将变量i转换为字符串指定的类型t，非必须参数extraParams泳衣额外的参数传递
+// 将变量i转换为字符串指定的类型t，非必须参数extraParams用以额外的参数传递
 func Convert(i interface{}, t string, extraParams...interface{}) interface{} {
     switch t {
         case "int":             return Int(i)

g/util/grand/grand.go

@@ -7,18 +7,9 @@
 // 随机数管理
 package grand
 
-import (
-    "time"
-)
-
 var letters = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789")
 var digits  = []rune("0123456789")
 
-// 自定义的 rand.Intn
-func intn (max int) int {
-    return int(time.Now().UnixNano())%max
-}
-
 // 获得一个 min, max 之间的随机数(min <= x <= max)
 func Rand (min, max int) int {
     if min >= max {

g/util/grand/grand_intn.go

@@ -0,0 +1,45 @@
+// Copyright 2018 gf Author(https://gitee.com/johng/gf). All Rights Reserved.
+//
+// This Source Code Form is subject to the terms of the MIT License.
+// If a copy of the MIT was not distributed with this file,
+// You can obtain one at https://gitee.com/johng/gf.
+
+package grand
+
+import (
+    "crypto/rand"
+    "encoding/binary"
+)
+
+const (
+    gBUFFER_SIZE = 10000 // 缓冲区uint64数量大小
+)
+
+var (
+    bufferChan = make(chan uint64, gBUFFER_SIZE)
+)
+
+// 使用缓冲区实现快速的随机数生成
+func init() {
+    buffer := make([]byte, 1024)
+    go func() {
+        for {
+            if n, err := rand.Read(buffer); err != nil {
+                panic(err)
+            } else {
+                for i := 0; i < n - 8; i += 8 {
+                    bufferChan <- binary.LittleEndian.Uint64(buffer[i : i + 8])
+                }
+            }
+        }
+    }()
+}
+
+// 自定义的 rand.Intn ，绝对随机
+func intn (max int) int {
+    n := int(<- bufferChan)%max
+    if n < 0 {
+        return -n
+    }
+    return n
+}

g/util/grand/grand_test.go

@@ -15,6 +15,6 @@ import (
 
 func Benchmark_Rand(b *testing.B) {
     for i := 0; i < b.N; i++ {
-        grand.Rand(0, 200)
+        grand.Rand(0, 999999999)
     }
 }

geg/other/test.go

@@ -3,13 +3,11 @@ package main
 import (
     "fmt"
     "gitee.com/johng/gf/g/os/gtime"
+    "strconv"
 )
 
 func main() {
-    s := `
-[INFO] 2018-11-04 12:48:01  2018-11-04 12:48:01 ["handle eventMedlinker\\Med3Svr\\App\\Events\\Task\\InviteUserVerifyEvent::__set_state(array(\n   'deviceNum' => '25a715ff8d4835197299d7dab067841e',\n   'userIdList' => \n  array (\n    0 => '62506063',\n  ),\n   'dataId' => '',\n   'eventTime' => NULL,\n))"] [med3-svr-6c8c9b9f4f-fl6g9]
-
-`
-    t := gtime.ParseTimeFromContent(s)
-    fmt.Println(t.String())
+    fmt.Println(strconv.FormatInt(gtime.Nanosecond(), 32))
+    fmt.Println(gtime.Second())
+    fmt.Println(gtime.Nanosecond())
 }

geg/util/grand/grand.go

@@ -0,0 +1,12 @@
+package main
+
+import (
+    "fmt"
+    "gitee.com/johng/gf/g/util/grand"
+)
+
+func main() {
+    for i := 0; i < 10; i++ {
+        fmt.Println(grand.Rand(0, 99999))
+    }
+}

geg/util/grand/rand.go

@@ -0,0 +1,83 @@
+package main
+
+import (
+    crand "crypto/rand"
+    "encoding/binary"
+    "fmt"
+    "gitee.com/johng/gf/g/os/gtime"
+    mrand "math/rand"
+    "os"
+    "time"
+)
+
+// int 随机
+func a1() {
+    s1 := mrand.NewSource(time.Now().UnixNano())
+    r1 := mrand.New(s1)
+    for i := 0; i < 10; i++ {
+        fmt.Printf("%d ", r1.Intn(100))
+    }
+    fmt.Printf("\n")
+}
+
+// 0/1 true/false  随机
+func a2() {
+    // Go编程这本书上例子.
+    ch := make(chan int, 1)
+    for i := 0; i < 10; i++ {
+        select {
+        case ch <- 0:
+        case ch <- 1:
+        }
+        r := <-ch
+        fmt.Printf("%d ", r)
+    }
+    fmt.Printf("\n")
+}
+
+//真随机 -- 用标准库封装好的
+func a3() {
+    b := make([]byte, 16)
+    // On Unix-like systems, Reader reads from /dev/urandom.
+    // On Windows systems, Reader uses the CryptGenRandom API.
+    _, err := crand.Read(b) //返回长度为0 - 32 的值
+    if err != nil {
+        fmt.Println("[a3] ", err)
+        return
+    }
+    fmt.Println("[a3] b:", b)
+}
+
+//真随机 -- 我们直接调真随机文件生成了事。 但注意，它是阻塞式的。
+func a4() {
+    f, err := os.Open("/dev/random")
+    if err != nil {
+        fmt.Println("[a4] ", err)
+        return
+    }
+    defer f.Close()
+
+    b1 := make([]byte, 16)
+    _, err = f.Read(b1)
+    if err != nil {
+        fmt.Println("[a4] ", err)
+        return
+    }
+    fmt.Println("[a4] Read /dev/random:", b1)
+}
+
+// a3 的另一种实现方式
+func a5() {
+    var ret int32
+    binary.Read(crand.Reader, binary.LittleEndian, &ret)
+    fmt.Println("[a5] ret:", ret)
+}
+
+func main() {
+    fmt.Println("a1:", gtime.FuncCost(a1))
+    fmt.Println("a2:", gtime.FuncCost(a2))
+    fmt.Println("a3:", gtime.FuncCost(a3))
+    fmt.Println("a4:", gtime.FuncCost(a4))
+    fmt.Println("a5:", gtime.FuncCost(a5))
+}
+