protobson

Description

protobson is a Go library consisting of a BSON codec for Protobuf messages that can be used with mongo-go-driver.

This library uses the second major version of the Go Protobuf API.

Main difference from original library is ability to set custom field naming - all you need is to make two functions to get document field name from proto field descriptor and versa.

Overview

• Usage
• Credits

Usage

Complete example can be seen in example directory

Below is a snippet making use of this codec by registering it with the MongoDB Go library:

package main

import (
	"log"
    "reflect"

    "go.mongodb.org/mongo-driver/bson"
    "go.mongodb.org/mongo-driver/mongo/options"
    "google.golang.org/protobuf/proto"

    "github.com/custom-app/protobson"
)

func main() {
    regBuilder := bson.NewRegistryBuilder()
    codec := protobson.NewCodec()

    msgType := reflect.TypeOf((*proto.Message)(nil)).Elem()
    registry := regBuilder.RegisterHookDecoder(msgType, codec).RegisterHookEncoder(msgType, codec).Build()

    opts := options.Client().SetRegistry(registry)
    opts.ApplyURI("mongodb://localhost:27017")
	client, err := mongo.Connect(context.Background(), opts)
	if err != nil {
		log.Panicln(err)
	}
	...
}

Note the use of RegisterHookDecoder and RegisterHookEncoder methods. Those ensure that given codec will be used to encode and decode values which type implement the interface. Since every Protobuf message implements the proto.Message interface, the codec will work with any message value.

Credits

This library is originally based on protomongo, part of the MIT-licensed dataform project by Tada Science, Inc.