1.简介与安装

简介: 无, 懂的都懂

安装

sudo apt install protobuf-compiler protobuf-c-compiler libprotobuf-dev

编译依赖

pkg-config --cflags --libs protobuf

-pthread -lprotobuf -pthread

编译选项: -pthread
链接选项: -lprotobuf -pthread

2.实例

1.代码

实例1

addressbook.proto

syntax = "proto3";package tutorial;message Person {string name = 1;string email = 2;
}message AddressBook {repeated Person people = 1;
}

1_addressbook_protobuf实例.cc

#include <iostream>
#include <fstream>
#include <string>
#include "addressbook.pb.h"void WriteAddressBook()
{tutorial::AddressBook address_book;// 添加一个 Persontutorial::Person *person = address_book.add_people();person->set_name("Alice");person->set_email("alice@example.com");// 写入到文件std::ofstream output("addressbook.data", std::ios::binary);if (!address_book.SerializeToOstream(&output)){std::cerr << "Failed to write address book." << std::endl;return;}
}void ReadAddressBook()
{tutorial::AddressBook address_book;// 从文件读取std::ifstream input("addressbook.data", std::ios::binary);if (!address_book.ParseFromIstream(&input)){std::cerr << "Failed to read address book." << std::endl;return;}// 输出读取到的人名for (int i = 0; i < address_book.people_size(); ++i){const tutorial::Person &person = address_book.people(i);std::cout << "Name: " << person.name() << ", Email: " << person.email() << std::endl;}
}int main()
{WriteAddressBook();ReadAddressBook();return 0;
}

实例2

person.proto

syntax = "proto3";  // 使用Protocol Buffers v3语法package example;  // 定义包名，便于组织和避免命名冲突message Person {  // 定义名为Person的消息类型string name = 1;  // 字符串类型字段，标签为1int32 id = 2;    // 整型字段，标签为2bool is_active = 3;  // 布尔型字段，标签为3repeated string email = 4;  // 重复字段，表示字符串列表，标签为4
}

2_protobuf_person_序列号到字节.cc

#include "person.pb.h"
#include <fstream>
#include <iostream>
#include <stdint.h>
#include <vector>
using namespace std;// 写入文件
void WriteToFile(const std::string& filename, const example::Person& person) {std::fstream output(filename, std::ios::out | std::ios::trunc | std::ios::binary);if (!person.SerializeToOstream(&output)) {std::cerr << "Failed to write person." << std::endl;}
}// 从文件读取
void ReadFromFile(const std::string& filename, example::Person& person) {std::fstream input(filename, std::ios::in | std::ios::binary);if (!person.ParseFromIstream(&input)) {std::cerr << "Failed to parse person." << std::endl;}
}// 打印反序列化后的数据
void PrintPerson(const example::Person& person) {std::cout << "Name: " << person.name() << std::endl;std::cout << "ID: " << person.id() << std::endl;std::cout << "Is Active: " << person.is_active() << std::endl;// 打印反序列化后的数据for (int i = 0; i < person.email_size(); ++i) {std::cout << "Email " << i + 1 << ": " << person.email(i) << std::endl;}
}int main() {// 创建并填充一个Person对象example::Person person;person.set_name("Alice");person.set_id(123);person.set_is_active(true);person.add_email("alice@example.com");person.add_email("alice.personal@gmail.com");// 1.序列化到 字节uint8_t buf[256] = { 0 };bool ret = person.SerializeToArray(buf, sizeof(buf));// 2.反序列化从 字节example::Person new_person;ret = new_person.ParseFromArray(buf, sizeof(buf));cout << "result ret: " << ret << endl;PrintPerson(new_person);// 3.读写probuf测试WriteToFile("person.bin", person);  // 写入文件ReadFromFile("person.bin", new_person); // 从文件读取PrintPerson(new_person);            // 打印反序列化后的数据return 0;
}

2.scons编译

SConstruct

import os
## 模板2
env = Environment()
env["PROGSUFFIX"] = ".out"            # 可执行后缀.out
env["CCFLAGS"] = " -g3 -O0 -Wall"       # gdb 调试开关
# -pthread -lprotobuf
env.MergeFlags(["!pkg-config protobuf --cflags --libs"])def build_protobuf(file_path):file,file_ext = os.path.splitext(file_path)print(file,file_ext)if file_ext != ".proto":raise f"{file_path} not .proto file"cmd=f"protoc --cpp_out=. {file}.proto"Command(f"{file}.pb.h",file_path,cmd)build_protobuf("addressbook.proto")
env.Program(Split("1_addressbook_protobuf实例.cc addressbook.pb.cc"))
build_protobuf("person.proto")
env.Program(Split("2_protobuf_person_序列号到字节.cc person.pb.cc"))

注意:
protobuf编译方法
protoc --cpp_out=. addressbook.proto

生成 addressbook.pb.cc addressbook.pb.h

scons中并没有直接构建protobuf方法, 可以使用scons Command(target_file, src_file, cmd)
Command使用说明: 如果src_file 时间戳比 target_file 新, 则执行cmd命令
示例: Command("addressbook.pb.h", "addressbook.proto", "rotoc --cpp_out=. addressbook.proto")

---

scons

scons: Reading SConscript files …
addressbook .proto
person .proto
scons: done reading SConscript files.
scons: Building targets …
protoc --cpp_out=. addressbook.proto
g++ -o 1_addressbook_protobuf实例.o -c -g3 -O0 -Wall -pthread 1_addressbook_protobuf实例.cc
g++ -o addressbook.pb.o -c -g3 -O0 -Wall -pthread addressbook.pb.cc
g++ -o 1_addressbook_protobuf实例.out -pthread 1_addressbook_protobuf实例.o addressbook.pb.o -lprotobuf
protoc --cpp_out=. person.proto
g++ -o 2_protobuf_person_序列号到字节.o -c -g3 -O0 -Wall -pthread 2_protobuf_person_序列号到字节.cc
g++ -o person.pb.o -c -g3 -O0 -Wall -pthread person.pb.cc
g++ -o 2_protobuf_person_序列号到字节.out -pthread 2_protobuf_person_序列号到字节.o person.pb.o -lprotobuf
scons: done building targets.

3.验证测试

./1_addressbook_protobuf实例.out

Name: Alice, Email: alice@example.com

./2_protobuf_person_序列号到字节.out

result ret: 0
Name: Alice
ID: 123
Is Active: 1
Email 1: alice@example.com
Email 2: alice.personal@gmail.com
Name: Alice
ID: 123
Is Active: 1
Email 1: alice@example.com
Email 2: alice.personal@gmail.com

3.其它实例

无

gitee 在线代码

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