Benchmarks for various encodings (Gob is the fastest, obviously, JSON is ~4 times slower, CSV is ~10 times slower)

encoding_test.go

package main

import (
	"bytes"
	"encoding/csv"
	"encoding/gob"
	"encoding/json"
	"math/rand"
	"testing"
)

func makeBlob() []byte {
	blob := make([]byte, 1000000, 1000000)
	for i := 0; i < len(blob); i++ {
		blob[i] = byte(rand.Intn(0x100))
	}
	return blob
}

func BenchmarkJSONBinary(b *testing.B) {
	blob := makeBlob()
	for i := 0; i < b.N; i++ {
		if _, err := json.Marshal(blob); err != nil {
			b.Error(err)
		}
	}
}

func BenchmarkCSVBinary(b *testing.B) {
	blob := makeBlob()
	out := &bytes.Buffer{}
	w := csv.NewWriter(out)
	for i := 0; i < b.N; i++ {
		if err := w.Write([]string{string(blob)}); err != nil {
			b.Error(err)
		}
	}
}

func BenchmarkGobBinary(b *testing.B) {
	blob := makeBlob()
	out := &bytes.Buffer{}
	w := gob.NewEncoder(out)
	for i := 0; i < b.N; i++ {
		if err := w.Encode(blob); err != nil {
			b.Error(err)
		}
	}
}

func makeShortText() []byte {
	text := make([]byte, 1000, 1000)
	for i := 0; i < len(text); i++ {
		text[i] = byte(rand.Intn(26) + 'a')
	}
	return text
}

func BenchmarkJSONShortText(b *testing.B) {
	text := makeShortText()
	for i := 0; i < b.N; i++ {
		if _, err := json.Marshal(text); err != nil {
			b.Error(err)
		}
	}
}

func BenchmarkCSVShortText(b *testing.B) {
	text := makeShortText()
	out := &bytes.Buffer{}
	w := csv.NewWriter(out)
	for i := 0; i < b.N; i++ {
		if err := w.Write([]string{string(text)}); err != nil {
			b.Error(err)
		}
	}
}

func BenchmarkGobShortText(b *testing.B) {
	text := makeShortText()
	out := &bytes.Buffer{}
	w := gob.NewEncoder(out)
	for i := 0; i < b.N; i++ {
		if err := w.Encode(text); err != nil {
			b.Error(err)
		}
	}
}