golang-latency-printer.go

import (
	"fmt"
	"time"
)

type LatencyPrinter struct {
	beginTime time.Time
}

func (h *LatencyPrinter) Begin() {
	h.beginTime = time.Now()
}

func (h *LatencyPrinter) End(s string) {
	fmt.Println(s, ". latency:", time.Since(h.beginTime))
}

func main() {
	var h LatencyPrinter
	h.Begin()
	defer h.End("test latency")
}