gistfile1.txt

goos: darwin
goarch: amd64
pkg: test-sort
BenchmarkSort/setsize_10/sort-4      5000000	       295 ns/op	      32 B/op	       1 allocs/op
BenchmarkSort/setsize_10/slice-4     3000000	       598 ns/op	     112 B/op	       3 allocs/op
BenchmarkSort/setsize_100/sort-4      200000	      8279 ns/op	      32 B/op	       1 allocs/op
BenchmarkSort/setsize_100/slice-4     100000	     13276 ns/op	     112 B/op	       3 allocs/op
BenchmarkSort/setsize_1000/sort-4      10000	    165268 ns/op	      32 B/op	       1 allocs/op
BenchmarkSort/setsize_1000/slice-4     10000	    209613 ns/op	     112 B/op	       3 allocs/op
BenchmarkSort/setsize_10000/sort-4      1000	   2226969 ns/op	      32 B/op	       1 allocs/op
BenchmarkSort/setsize_10000/slice-4      500	   2716022 ns/op	     112 B/op	       3 allocs/op
BenchmarkSort/setsize_100000/sort-4       50	  28135270 ns/op	      32 B/op	       1 allocs/op
BenchmarkSort/setsize_100000/slice-4      50	  33965116 ns/op	     112 B/op	       3 allocs/op
PASS
ok  	test-sort	18.454s

sort_benchmarks_test.go

package main

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

type datum struct {
	time time.Time
}

type datums []datum

func (d datums) Len() int {
	return len(d)
}

func (d datums) Less(i, j int) bool {
	return d[i].time.Before(d[j].time)
}

func (d datums) Swap(i, j int) {
	d[i], d[j] = d[j], d[i]
}

var dataset datums

func BenchmarkSort(b *testing.B) {
	rand.Seed(42)

	now := time.Now().Unix()

	for i := 10; i < 1e6; i = i * 10 {
		b.Run(fmt.Sprintf("setsize %d", i), func(b *testing.B) {
			testdata := make([]datum, 0, i)
			for i := 0; i < cap(testdata); i++ {
				d := datum{time.Unix(rand.Int63n(now), 0)}
				testdata = append(testdata, d)
			}

			dataset = make(datums, i)

			b.ResetTimer()

			benchSort(b, dataset, testdata)
		})
	}
}

func benchSort(b *testing.B, dataset, testdata datums) {
	b.Run("sort", func(b *testing.B) {
		for i := 0; i < b.N; i++ {
			copy(dataset, testdata)
			sort.Sort(dataset)
		}
	})

	b.Run("slice", func(b *testing.B) {
		for i := 0; i < b.N; i++ {
			copy(dataset, testdata)
			sort.Slice(dataset, func(i, j int) bool {
				return dataset[i].time.Before(dataset[j].time)
			})
		}
	})
}