有没有一种有效的方法来计算golang的执行时间？

Question

我正在寻找计算执行时间的最佳方法.

func main() {
    start := time.Now()

    time.Sleep(time.Second * 2)

    //something doing here

    elapsed := time.Since(start)
    fmt.Printf("page took %s", elapsed)
}

上面的代码工作正常.

但是当我使用模板时,我必须为每个模板函数再次编写它.

有没有一种有效的方法来计算执行时间,包括模板？

Answer 1

如果您要对整个函数进行计时,那么您可以使用它defer来消除一些重复的代码.

func elapsed(what string) func() {
    start := time.Now()
    return func() {
        fmt.Printf("%s took %v\n", what, time.Since(start))
    }
}

func main() {
    defer elapsed("page")()  // <-- The trailing () is the deferred call
    time.Sleep(time.Second * 2)
}

操场的例子

Answer 2

Cerise提供的解决方案非常完美.

另外,如果你不想显式传递函数名,你可以像这样完成它:

func SomeFunction(list *[]string) {
    defer TimeTrack(time.Now())
    // Do whatever you want.
}

func TimeTrack(start time.Time) {
    elapsed := time.Since(start)

    // Skip this function, and fetch the PC and file for its parent.
    pc, _, _, _ := runtime.Caller(1)

    // Retrieve a function object this functions parent.
    funcObj := runtime.FuncForPC(pc)

    // Regex to extract just the function name (and not the module path).
    runtimeFunc := regexp.MustCompile(`^.*\.(.*)$`)
    name := runtimeFunc.ReplaceAllString(funcObj.Name(), "$1")

    log.Println(fmt.Sprintf("%s took %s", name, elapsed))
}

结果,你会得到:

SomeFunction took 15.483µs

有关更多信息,请参阅此文章:Go Function Tracing

分享知识.:)

Answer 3

使用初始化函数

package main

import (
    "fmt"
    "time"
)

var start time.Time

func init() {
    start = time.Now()
}

func getChars(s string) {
    for _, c := range s {
        fmt.Printf("%c at time %v\n", c, time.Since(start))
        time.Sleep(10 * time.Millisecond)
    }
}

func main() {
    fmt.Println("main execution started at time", time.Since(start))

    getChars("Hello")

    fmt.Println("\nmain execution stopped at time", time.Since(start))
}