maps_and_slices_test.go

package main

import (
	"math/rand"
	"testing"
)

type mapType map[int64]struct{}
type sliceType []int64

type finder interface {
	find(int64) bool
}

func (s sliceType) find(num int64) bool {
	for i := 0; i < len(s); i++ {
		if s[i] == num {
			return true
		}
	}
	return false
}

func (m mapType) find(num int64) bool {
	_, ok := m[num]
	return ok
}

func makeSlice(size int) sliceType {
	s := make(sliceType, size)
	for i := 0; i < size; i++ {
		s[i] = rand.Int63()
	}
	return s
}

func makeMap(size int) mapType {
	m := make(mapType)
	for i := 0; i < size; i++ {
		r := rand.Int63()
		m[r] = struct{}{}
	}
	return m
}

func benchFind(t *testing.B, finder finder) {
	t.ResetTimer()
	for i := 0; i < t.N; i++ {
		_ = finder.find(rand.Int63())
	}
}

func benchMap(size int, t *testing.B) {
	benchFind(t, makeMap(size))
}

func benchSlice(size int, t *testing.B) {
	benchFind(t, makeSlice(size))
}

func BenchmarkMaps4(t *testing.B) {
	benchMap(4, t)
}

func BenchmarkSlice4(t *testing.B) {
	benchSlice(4, t)
}

func BenchmarkMaps8(t *testing.B) {
	benchMap(8, t)
}

func BenchmarkSlice8(t *testing.B) {
	benchSlice(8, t)
}

func BenchmarkMaps16(t *testing.B) {
	benchMap(16, t)
}

func BenchmarkSlice16(t *testing.B) {
	benchSlice(16, t)
}

func BenchmarkMaps32(t *testing.B) {
	benchMap(32, t)
}

func BenchmarkSlice32(t *testing.B) {
	benchSlice(32, t)
}

func BenchmarkMaps64(t *testing.B) {
	benchMap(64, t)
}

func BenchmarkSlice64(t *testing.B) {
	benchSlice(64, t)
}

func BenchmarkMaps128(t *testing.B) {
	benchMap(128, t)
}

func BenchmarkSlice128(t *testing.B) {
	benchSlice(128, t)
}

func BenchmarkMaps256(t *testing.B) {
	benchMap(256, t)
}

func BenchmarkSlice256(t *testing.B) {
	benchSlice(256, t)
}


// RESULTS:

$ go test maps_and_slices_test.go -bench .
goos: darwin
goarch: amd64
BenchmarkMaps4-8        50000000                32.2 ns/op
BenchmarkSlice4-8       50000000                27.4 ns/op
BenchmarkMaps8-8        50000000                30.8 ns/op
BenchmarkSlice8-8       50000000                28.7 ns/op
BenchmarkMaps16-8       50000000                35.1 ns/op
BenchmarkSlice16-8      50000000                30.4 ns/op
BenchmarkMaps32-8       50000000                35.4 ns/op
BenchmarkSlice32-8      30000000                35.9 ns/op
BenchmarkMaps64-8       50000000                34.6 ns/op
BenchmarkSlice64-8      30000000                50.2 ns/op
BenchmarkMaps128-8      50000000                36.0 ns/op
BenchmarkSlice128-8     20000000                83.5 ns/op
BenchmarkMaps256-8      30000000                35.2 ns/op
BenchmarkSlice256-8     10000000               123 ns/op
PASS
ok      command-line-arguments  21.756s