main_test.go

package main

import (
	"fmt"
	"sort"
	"testing"
)

type testT struct {
	Name  string
	Price int
}

type testTSlice []*testT

func (t testTSlice) Len() int {
	return len(t)
}

func less(t testTSlice, i, j int) bool {
	return t[i].Price < t[j].Price
}

func (t testTSlice) Less(i, j int) bool {
	return less(t, i, j)
}

func swap(t testTSlice, i, j int) {
	t[i], t[j] = t[j], t[i]
}

func (t testTSlice) Swap(i, j int) {
	t[i], t[j] = t[j], t[i]
}

func newTestData(size int) testTSlice {
	tests := make(testTSlice, size)
	for i := size - 1; i >= 0; i-- {
		tests[i] = &testT{
			Name:  fmt.Sprintf("Item %d", i),
			Price: i * 100,
		}
	}
	return tests
}

func BenchmarkSort(b *testing.B) {
	tests := make([]testTSlice, b.N)
	for i := 0; i < b.N; i++ {
		tests[i] = newTestData(1000)
	}
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		sort.Sort(tests[i])
	}
}

func BenchmarkSlice(b *testing.B) {
	tests := make([]testTSlice, b.N)
	for i := 0; i < b.N; i++ {
		tests[i] = newTestData(1000)
	}
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		td := tests[i]
		sort.Slice(td, func(i, j int) bool {
			return less(td, i, j)
		})
	}
}

RUN

$ GOMAXPROCS=1 GOROOT=~/src/github.com/golang/go go test -bench  .
testing: warning: no tests to run
BenchmarkSort  	   30000	     57616 ns/op
BenchmarkSlice 	   30000	     43650 ns/op
PASS
ok  	github.com/k2wanko/sort-bench	38.994s

$ GOMAXPROCS=1 GOROOT=~/src/github.com/golang/go go test -bench . -benchmem
testing: warning: no tests to run
BenchmarkSort  	   20000	     62222 ns/op	      32 B/op	       1 allocs/op
BenchmarkSlice 	   30000	     50571 ns/op	      64 B/op	       2 allocs/op
PASS
ok  	github.com/k2wanko/sort-bench	37.401s

$ GOMAXPROCS=1 GOROOT=~/src/github.com/golang/go go test -bench . -benchmem
testing: warning: no tests to run
BenchmarkSort  	   20000	     70767 ns/op	      32 B/op	       1 allocs/op
BenchmarkSlice 	   20000	     69151 ns/op	      64 B/op	       2 allocs/op
PASS
ok  	github.com/k2wanko/sort-bench	41.482s