Go JSON 序列化性能评测：主流库 Benchmark 对比与选型实践

type User struct {
	ID        int64     `json:"id"`
	Name      string    `json:"name"`
	Email     string    `json:"email"`
	Roles     []string  `json:"roles"`
	IsActive  bool      `json:"is_active"`
	ExtraInfo MetaData  `json:"extra_info"`
	CreatedAt time.Time `json:"created_at"`
}

type MetaData struct {
	IP        string `json:"ip"`
	Device    string `json:"device"`
	LoginDays int    `json:"login_days"`
}

func BenchmarkMarshal(b *testing.B) {
	u := mockUser()
	b.Run("stdlib", func(b *testing.B) {
		for i := 0; i < b.N; i++ {
			_, _ = json.Marshal(u)
		}
	})
	b.Run("json-iterator", func(b *testing.B) {
		for i := 0; i < b.N; i++ {
			_, _ = jsoniter.Marshal(u)
		}
	})
	b.Run("go-json", func(b *testing.B) {
		for i := 0; i < b.N; i++ {
			_, _ = gojson.Marshal(u)
		}
	})
	b.Run("sonic", func(b *testing.B) {
		for i := 0; i < b.N; i++ {
			_, _ = sonic.Marshal(u)
		}
	})
}

goos: darwin
goarch: arm64
pkg: bench-json

BenchmarkMarshal/stdlib-10          	 1258603	       945.2 ns/op	     288 B/op	       2 allocs/op
BenchmarkMarshal/json-iterator-10   	 3154820	       380.1 ns/op	     256 B/op	       2 allocs/op
BenchmarkMarshal/go-json-10         	 3921045	       305.6 ns/op	     240 B/op	       1 allocs/op
BenchmarkMarshal/sonic-10           	 6842100	       175.4 ns/op	     240 B/op	       1 allocs/op

BenchmarkUnmarshal/stdlib-10        	  610234	      1950.8 ns/op	     432 B/op	       9 allocs/op
BenchmarkUnmarshal/json-iterator-10 	 1845120	       648.2 ns/op	     256 B/op	       4 allocs/op
BenchmarkUnmarshal/go-json-10       	 2105430	       570.0 ns/op	     336 B/op	       5 allocs/op
BenchmarkUnmarshal/sonic-10         	 3890124	       308.2 ns/op	     240 B/op	       2 allocs/op

var bufPool = sync.Pool{
	New: func() any {
		return bytes.NewBuffer(make([]byte, 0, 1024))
	},
}

func MarshalWithPool(v any) ([]byte, error) {
	buf := bufPool.Get().(*bytes.Buffer)
	buf.Reset()
	defer bufPool.Put(buf)

	enc := sonic.ConfigFastest.NewEncoder(buf)
	if err := enc.Encode(v); err != nil {
		return nil, err
	}
	
	// 拷贝出来或直接使用 buf.Bytes()
	res := make([]byte, buf.Len())
	copy(res, buf.Bytes())
	return res, nil
}

type BigPayload struct {
	Header  Header          `json:"header"`
	Content json.RawMessage `json:"content"` // 延迟解析或透传，避免无意义的遍历
}