b_test.go

// go test -run none -bench .
package b

import (
	"math/rand"
	"sort"
	"testing"
)

const M = 8192

func crunch(data []int) int {
	var sum int
	for _, v := range data {
		if v > 0 {
			sum++
		}
	}
	return sum
}

func makeRandomList() []int {
	data := make([]int, M)
	rand.Seed(0)
	for i := range data {
		data[i] = rand.Intn(2)
	}
	return data
}

func BenchmarkSortedArray(b *testing.B) {
	data := makeRandomList()
	sort.Ints(data) // sort it
	for i := 0; i < b.N; i++ {
		crunch(data)
	}
}

func BenchmarkUnsortedArray(b *testing.B) {
	data := makeRandomList()
	for i := 0; i < b.N; i++ {
		crunch(data)
	}
}