Golang 获得文件名最快的代码实现方式比较

获得文件名最快的代码实现方式比较百万次获得文件名称的需要的时间比较

zhengzizhi

4771人浏览 · 2017-06-22 11:48:47

zhengzizhi · 2017-06-22 11:48:47 发布

package main

import (
   "fmt"
   "os"
   "path/filepath"
   "strings"
   "time"
)

//获得文件名最快的代码实现方式比较
func main() {
   filename := "/root/Desktop/模特唐嘉灵2.jpg"
   //方案一
   startTime1 := time.Now()
   for i := 0; i < 1000000; i++ {
       _ = filepath.Base(filename)
   }
   endTime1 := time.Now()

   //方案二
   startTime2 := time.Now()
   for i := 0; i < 1000000; i++ {
       start := strings.LastIndex(filename, string(os.PathSeparator)) + 1
       data := []rune(filename)
       _ = string(data[start:])

   }
   endTime2 := time.Now()

   //方案三
   startTime3 := time.Now()
   for i := 0; i < 1000000; i++ {
       arr := strings.Split(filename, string(os.PathSeparator))
       _ = arr[len(arr)-1]
   }
   endTime3 := time.Now()

   var duration1 time.Duration = endTime1.Sub(startTime1)
   var second1 float64 = duration1.Seconds()

   var duration2 time.Duration = endTime2.Sub(startTime2)
   var second2 float64 = duration2.Seconds()

   var duration3 time.Duration = endTime3.Sub(startTime3)
   var second3 float64 = duration3.Seconds()

   //输出运行耗时：
   fmt.Println(second1) //方案一
   fmt.Println(second2) //方案二
   fmt.Println(second3) //方案三

}

控制台打印输出百万次获得文件名称的需要的时间：

2017/06/22 11:44:01 debugger.go:97: launching process with args: [/root/code/go/src/contoso.org/hello/debug]
API server listening at: 127.0.0.1:2345
2017/06/22 11:44:01 debugger.go:505: continuing
0.025708834    //方案一，它最快
0.240723813   //方案二，它最慢
0.210655292   //方案三