test.go

package main

import (
	"bytes"
	"compress/gzip"
	"fmt"
	"io/ioutil"
	"net/http"
	"testing"

	"github.com/andybalholm/brotli"
)

func main() {
	res, err := http.Get("https://www.google.com/")
	if err != nil {
		panic(err)
	}

	data, err := ioutil.ReadAll(res.Body)
	if err != nil {
		panic(err)
	}

	buf := bytes.Buffer{}
	buf.Grow(len(data))

	b := brotli.NewWriter(&buf)
	n := 0
	a := testing.AllocsPerRun(1000, func() {
		if _, err := b.Write(data); err != nil {
			panic(err)
		}
		if err := b.Flush(); err != nil {
			panic(err)
		}
		n += buf.Len()
		buf.Reset()
		b.Reset(&buf)
	})
	fmt.Println("allocs per run:", a)

	g := gzip.NewWriter(&buf)
	m := 0
	a = testing.AllocsPerRun(1000, func() {
		if _, err := g.Write(data); err != nil {
			panic(err)
		}
		if err := g.Flush(); err != nil {
			panic(err)
		}
		m += buf.Len()
		buf.Reset()
		g.Reset(&buf)
	})
	fmt.Println("allocs per run:", a)

	fmt.Println("brotli:", n, "gzip:", m, "ratio:", 1-float64(n)/float64(m))
}

test_test.go

package main

import (
	"bytes"
	"compress/gzip"
	"io/ioutil"
	"net/http"
	"testing"

	"github.com/andybalholm/brotli"
)

var data []byte

func init() {
	res, err := http.Get("https://www.google.com/")
	if err != nil {
		panic(err)
	}

	data, err = ioutil.ReadAll(res.Body)
	if err != nil {
		panic(err)
	}
}

func BenchmarkBrotli(b *testing.B) {
	buf := bytes.Buffer{}
	buf.Grow(len(data))

	o := brotli.NewWriter(&buf)
	for i := 0; i < b.N; i++ {
		if _, err := o.Write(data); err != nil {
			panic(err)
		}
		if err := o.Flush(); err != nil {
			panic(err)
		}
		buf.Reset()
		o.Reset(&buf)
	}
}

func BenchmarkGzip(b *testing.B) {
	buf := bytes.Buffer{}
	buf.Grow(len(data))

	g := gzip.NewWriter(&buf)
	for i := 0; i < b.N; i++ {
		if _, err := g.Write(data); err != nil {
			panic(err)
		}
		if err := g.Flush(); err != nil {
			panic(err)
		}
		buf.Reset()
		g.Reset(&buf)
	}
}