json.go

/*
Copyright © 2020 Henry Huang <hhh@rutcode.com>

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/

package json

import (
	"bytes"
	"encoding/json"

	"github.com/golang/protobuf/jsonpb"
	"github.com/golang/protobuf/proto"
	"github.com/iTrellis/trellis/service/codec"
	"github.com/oxtoacart/bpool"
)

var jsonpbMarshaler = &jsonpb.Marshaler{}

// create buffer pool with 16 instances each preallocated with 256 bytes
var bufferPool = bpool.NewSizedBufferPool(16, 256)

func NewCodec() codec.Codec {
	return &Marshaler{}
}

type Marshaler struct{}

func (Marshaler) Marshal(v interface{}) ([]byte, error) {
	if pb, ok := v.(proto.Message); ok {
		buf := bufferPool.Get()
		defer bufferPool.Put(buf)
		if err := jsonpbMarshaler.Marshal(buf, pb); err != nil {
			return nil, err
		}
		return buf.Bytes(), nil
	}
	return json.Marshal(v)
}

func (Marshaler) Unmarshal(d []byte, v interface{}) error {
	if pb, ok := v.(proto.Message); ok {
		return jsonpb.Unmarshal(bytes.NewReader(d), pb)
	}
	return json.Unmarshal(d, v)
}

func (Marshaler) String() string {
	return "json"
}