全部博文（396）
分类： 嵌入式
2019-08-22 13:31:25
1、在.proto文件中定义消息格式
package tutorial; message Person{
required string name =1;
required int32 id =2;
optional string email =3;
enumPhoneType{
MOBILE =0;
HOME =1;
WORK =2;
}
message PhoneNumber{
required string number =1;
optional PhoneType type =2[default= HOME];
}
repeated PhoneNumber phone =4;
}
message AddressBook{
repeated Person person =1;
}
protoc -I=$SRC_DIR --cpp_out=$DST_DIR $SRC_DIR/addressbook.proto
// name inlinebool has_name()const; inlinevoid clear_name(); inlineconst::std::string& name()const; inlinevoid set_name(const::std::string& value); inlinevoid set_name(constchar* value); inline::std::string* mutable_name(); // id inlinebool has_id()const; inlinevoid clear_id(); inlineint32_t id()const; inlinevoid set_id(int32_t value); // email inlinebool has_email()const; inlinevoid clear_email(); inlineconst::std::string& email()const; inlinevoid set_email(const::std::string& value); inlinevoid set_email(constchar* value); inline::std::string* mutable_email(); // phone inlineint phone_size()const; inlinevoid clear_phone(); inlineconst::google::protobuf::RepeatedPtrField<::tutorial::Person_PhoneNumber>& phone()const; inline::google::protobuf::RepeatedPtrField<::tutorial::Person_PhoneNumber>* mutable_phone(); inlineconst::tutorial::Person_PhoneNumber& phone(int index)const; inline::tutorial::Person_PhoneNumber* mutable_phone(int index); inline::tutorial::Person_PhoneNumber* add_phone();
4、枚举与嵌套类
bool IsInitialized() const: 确认required字段是否被设置
string DebugString() const: 返回消息的可读表示，用于调试
void CopyFrom(const Person& from): 使用给定消息值copy
void Clear(): 清除所有元素为空状态
bool SerializeToString(string* output) const: 序列化消息，将存储字节的以string方式输出。注意字节是二进制，而非文本；
bool ParseFromString(const string& data): 解析给定的string
bool SerializeToOstream(ostream* output) const: 写消息给定的c++ ostream中
bool ParseFromIstream(istream* input): 从给定的c++ istream中解析出消息
7、protobuf和 oo设计#include #include #include #include"addressbook.pb.h" usingnamespace std; // This function fills in a Person message based on user input. voidPromptForAddress(tutorial::Person* person){ cout <<"Enter person ID number: "; int id; cin >> id; person->set_id(id); cin.ignore(256,'\n'); cout <<"Enter name: "; getline(cin,*person->mutable_name()); cout <<"Enter email address (blank for none): "; string email; getline(cin, email); if(!email.empty()){ person->set_email(email); } while(true){ cout <<"Enter a phone number (or leave blank to finish): "; string number; getline(cin, number); if(number.empty()){ break; } tutorial::Person::PhoneNumber* phone_number = person->add_phone(); phone_number->set_number(number); cout <<"Is this a mobile, home, or work phone? "; string type; getline(cin, type); if(type =="mobile"){ phone_number->set_type(tutorial::Person::MOBILE); }elseif(type =="home"){ phone_number->set_type(tutorial::Person::HOME); }elseif(type =="work"){ phone_number->set_type(tutorial::Person::WORK); }else{ cout <<"Unknown phone type. Using default."<< endl; } } } // Main function: Reads the entire address book from a file, // adds one person based on user input, then writes it back out to the same // file. int main(int argc,char* argv[]){ // Verify that the version of the library that we linked against is // compatible with the version of the headers we compiled against. GOOGLE_PROTOBUF_VERIFY_VERSION; if(argc !=2){ cerr <<"Usage: "<< argv[0]<<" ADDRESS_BOOK_FILE"<< endl; return-1; } tutorial::AddressBook address_book; { // Read the existing address book. fstream input(argv[1], ios::in| ios::binary); if(!input){ cout << argv[1]<<": File not found. Creating a new file."<< endl; }elseif(!address_book.ParseFromIstream(&input)){ cerr <<"Failed to parse address book."<< endl; return-1; } } // Add an address. PromptForAddress(address_book.add_person()); { // Write the new address book back to disk. fstream output(argv[1], ios::out| ios::trunc | ios::binary); if(!address_book.SerializeToOstream(&output)){ cerr <<"Failed to write address book."<< endl; return-1; } } // Optional: Delete all global objects allocated by libprotobuf. google::protobuf::ShutdownProtobufLibrary(); return0; }
#include #include #include #include"addressbook.pb.h" usingnamespace std; // Iterates though all people in the AddressBook and prints info about them. voidListPeople(const tutorial::AddressBook& address_book){ for(int i =0; i <address_book.person_size(); i++){ const tutorial::Person& person = address_book.person(i); cout <<"Person ID: "<<person.id()<< endl; cout <<" Name: "<<person.name()<< endl; if(person.has_email()){ cout <<" E-mail address: "<<person.email()<< endl; } for(int j =0; j <person.phone_size(); j++){ const tutorial::Person::PhoneNumber& phone_number = person.phone(j); switch(phone_number.type()){ casetutorial::Person::MOBILE: cout <<" Mobile phone #: "; break; casetutorial::Person::HOME: cout <<" Home phone #: "; break; casetutorial::Person::WORK: cout <<" Work phone #: "; break; } cout <<phone_number.number()<< endl; } } } // Main function: Reads the entire address book from a file and prints all // the information inside. int main(int argc,char* argv[]){ // Verify that the version of the library that we linked against is // compatible with the version of the headers we compiled against. GOOGLE_PROTOBUF_VERIFY_VERSION; if(argc !=2){ cerr <<"Usage: "<< argv[0]<<" ADDRESS_BOOK_FILE"<< endl; return-1; } tutorial::AddressBook address_book; { // Read the existing address book. fstream input(argv[1], ios::in| ios::binary); if(!address_book.ParseFromIstream(&input)){ cerr <<"Failed to parse address book."<< endl; return-1; } } ListPeople(address_book); // Optional: Delete all global objects allocated by libprotobuf. google::protobuf::ShutdownProtobufLibrary(); return0; }
