benchmark_test.go

package main

import "testing"

var (
	array [1000000]int
	slice = make([]int, 1000000)
	Map   = make(map[int]int)
	r     int // to avoid the compiler optimising away the access
)

func init() {
	for i, _ := range array {
		array[i] = i
		slice[i] = i
		Map[i] = i
	}
}

func TestDummy(t *testing.T) {
	println(r) // force
}

func BenchmarkArrayAccess(b *testing.B) {
	for i := 0; i < 1000000; i++ {
		r = array[i]
	}
}

func BenchmarkSliceAccess(b *testing.B) {
	for i := 0; i < 1000000; i++ {
		r = slice[i]
	}
}

func BenchmarkMapAccess(b *testing.B) {
	for i := 0; i < 1000000; i++ {
		r = Map[i]
	}
}