I'm looking for the best way to calculate execution time in go.
func main() {
start := time.Now()
time.Sleep(time.Second * 2)
//something doing here
elapsed := time.Since(start)
fmt.Printf("page took %s", elapsed)
}
The code above works fine.
But when I use templates, I have to write it again for each template function.
Is there an efficient way to calculating execution time including templates ?
If you are timing an entire function, then you can use defer to eliminate some of the repetitive code.
func elapsed(what string) func() {
start := time.Now()
return func() {
fmt.Printf("%s took %v
", what, time.Since(start))
}
}
func main() {
defer elapsed("page")()
time.Sleep(time.Second * 2)
}
The solution provided by Cerise is perfect.
In addition, if you don't want to pass function name explicitly, you could accomplish it like this:
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))
}
As a result, you would get:
SomeFunction took 15.483µs
For more information, Refer this article: Go Function Tracing
Share the knowledge. :)
Use init function
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
", 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("
main execution stopped at time", time.Since(start))
}
You can easily get the execution time on your console using a defer function
defer functions execute even if the code get an error so you always get the execution time.
time package is used to get the time difference.
func main() {
now := time.Now()
defer func() {
fmt.Println(time.Now().Sub(now))
}()
// Here you can do whatever you want
}
Or you can use this code
func main() {
now := time.Now()
defer func() {
fmt.Println(time.Since(now))
}()
// Here you can do whatever you want
}
check the code in Playground for more. I added some functionality to recover from an error at the same time print the execution time, even if in the case of a panic error.