protobuf使用

编写结构

// Filename: person.proto

syntax="proto3";
package person;

message Person {
    string name = 1;
    int32 id = 2;
    uint32 age = 3;

    enum PhoneType {
        MOBILE = 0;
        HOME = 1;
        WORK = 2;
    }

    message PhoneNumber {
        string number = 1;
        PhoneType type = 2;
    }

    repeated PhoneNumber phone = 4;
}

生成C++文件

$ protoc -I=. --cpp_out=. person.proto
$ ls
person.pb.cc  person.pb.h  person.proto

编写例子

#include <iostream>
#include <iomanip>
#include "person.pb.h"

int main()
{
	person::Person person;	
	person.set_name("furong");
	person.set_id(1);
	person.set_age(10);
	
	person::Person_PhoneNumber *phone = person.add_phone();
	phone->set_number("010-110");
	phone = person.add_phone();
	phone->set_number("130-1234-5678");
	phone->set_type(person::Person::WORK);
	std::cout << "number = " << phone->number() << std::endl;
	phone->clear_number();
	
	uint32_t size = person.ByteSize();
	unsigned char byteArray[size];
	person.SerializeToArray(byteArray, size);
	
	for (int i = 0; i < size; i++)
	{
		std::cout << std::hex << std::setiosflags(std::ios::uppercase) << std::setfill('0') << std::setw(2) << static_cast<int>(byteArray[i]) << ' ';
	}
	
	std::cout << std::endl;
	
	person::Person parse_person;
	parse_person.ParseFromArray(byteArray, size);
	
	std::cout << "*****************************" << std::endl;
	std::cout << "id: " << parse_person.id() << std::endl;
	std::cout << "name: " << parse_person.name() << std::endl;
	std::cout << "age: " << std::dec << parse_person.age() << std::endl;
	
	for (int i = 0; i < parse_person.phone_size(); i++)
	{
		const person::Person_PhoneNumber &phone = parse_person.phone(i);
		std::cout << "phone_type: " << phone.type() << std::endl;
		std::cout << "phone_number: " << phone.number() << std::endl;
	}
	std::cout << "*****************************" << std::endl;
	
	return 0;
}

编译运行

$ g++ main.cpp person.pb.cc -I include -L lib -lprotobuf
$ ./a.out 
number = 130-1234-5678
0A 06 66 75 72 6F 6E 67 10 01 18 0A 22 09 0A 07 30 31 30 2D 31 31 30 22 02 10 02 
*****************************
id: 1
name: furong
age: 10
phone_type: 0
phone_number: 010-110
phone_type: 2
phone_number: 
*****************************