ProtoBuffer 简单例子

最近学了一下protobuf，写了一个简单的例子，如下：

person.proto文件

message Person{
	required string name = 1;
	required int32 age = 2;
	optional string email = 3;
	enum PhoneType{ 
		MOBILE = 1;
		HOME = 2;
		WORK = 3;
	}
	message Phone{
		required int32 id = 1;
		optional PhoneType type = 2 [default = HOME];
	}
	repeated string phoneNum = 4;  //对应于cpp的vector
}

安装好protoc以后，执行protoc person.proto --cpp_out=. 生成 person.pb.h和person.pb.cpp

写文件(write_person.cpp)：

#include 
#include "person.pb.h"
#include 
#include 

using namespace std;

int main(){
	string buffer;
	Person person;
	person.set_name("chemical");
	person.set_age(29);
	person.set_email("[email protected]");
	person.add_phonenum("abc");
	person.add_phonenum("def");
	fstream output("myfile",ios::out|ios::binary);
	person.SerializeToString(&buffer); //用这个方法，通常不用SerializeToOstream
	output.write(buffer.c_str(),buffer.size());
	return 0;
}

编译时要把生成的cpp和源文件一起编译，如下：g++ write_person.cpp person.pb.cpp -o write_person -I your_proto_include_path -L your_proto_lib_path -lprotoc -lprotobuf运行时记得要加上LD_LIBRARY_PATH=your_proto_lib_path

读文件(read_person.cpp)：

#include 
#include "person.pb.h"
#include 
#include 

using namespace std;

int main(){
	Person *person = new Person;
	char buffer[BUFSIZ];
	fstream input("myfile",ios::in|ios::binary);
	input.read(buffer,sizeof(Person));
	person->ParseFromString(buffer);  //用这个方法，通常不用ParseFromString
	cout << person->name() << person->phonenum(0) << endl;
	return 0;
}

编译运行方法同上：g++ read_person.cpp person.pb.cpp -o read_person -I your_proto_include_path -L your_proto_lib_path -lprotoc -lprotobuf