Blog Eleven Labs : Présentation de Protobuf

client.go

package main

import (
	"bufio"
	"bytes"
	fmt "fmt"
	"log"
	"net/http"

	proto "github.com/golang/protobuf/proto"
)

func main() {
	post := &Post{}
	resp, err := http.Get("http://127.0.0.1:8080/posts/1.proto")
	if err != nil {
		log.Fatal(err)
	}
	defer resp.Body.Close()

	sca := bufio.NewScanner(resp.Body)
	sca.Split(bufio.ScanRunes)

	var buf bytes.Buffer
	for sca.Scan() {
		buf.WriteString(sca.Text())
	}

	err = proto.Unmarshal(buf.Bytes(), post)
	if err != nil {
		log.Fatal("unmarshaling error: ", err)
	}

	fmt.Printf("Id: %d \n", post.GetId())
	fmt.Printf("Title: %s \n", post.GetTitle())
	fmt.Printf("Author: %s \n", post.GetAuthor())
}

post.proto

syntax = "proto3";

message Post {
    int32 id = 1;
    string title = 2;
    string author = 3;
}

server.go

package main

import (
	"encoding/json"
	"log"
	"net/http"

	proto "github.com/golang/protobuf/proto"
)

var post = &Post{
	Id:     1,
	Title:  "My awesome article",
	Author: "Quentin Neyrat",
}

func jsonHandler(w http.ResponseWriter, r *http.Request) {
	out, err := json.Marshal(post)
	if err != nil {
		log.Fatalln("Failed to serialize post in json:", err)
	}

	w.Write(out)
}

func protoHandler(w http.ResponseWriter, r *http.Request) {
	out, err := proto.Marshal(post)
	if err != nil {
		log.Fatalln("Failed to serialize post in protobuf:", err)
	}

	w.Write(out)
}

func main() {
	http.HandleFunc("/posts/1.json", jsonHandler)
	http.HandleFunc("/posts/1.proto", protoHandler)
	http.ListenAndServe(":8080", nil)
}