protobuf之实例使用（三）

news/2025/2/12 7:44:05/

protobuf安装后，在含有protoc执行文件的路径下，执行protoc程序，可以将.proto文件转换为.h和.cc文件。

1 .proto文件

syntax = "proto2"; 
package contacts;//定义联系人message
message PeopleInfo 
{required string name = 1;    //姓名required int32 age = 2;      //年龄required string sex = 3;    //姓名
}

2 protoc转换.proto文件

执行protoc进程，如下：

protoc --proto_path=/home/ceshi/protobuftest  --cpp_out=/home/ceshi/protobuftest  /home/ceshi/protobuftest/hello.proto

简要说明：

protoc 转换进程

--path_path  .proto文件存放的路径

--cpp_out   生成后的.h和.cc文件存放路径

3.h和.cc文件

（1）.h 文件

// Generated by the protocol buffer compiler.  DO NOT EDIT!
// source: hello.proto#ifndef PROTOBUF_hello_2eproto__INCLUDED
#define PROTOBUF_hello_2eproto__INCLUDED#include <string>#include <google/protobuf/stubs/common.h>#if GOOGLE_PROTOBUF_VERSION < 2005000
#error This file was generated by a newer version of protoc which is
#error incompatible with your Protocol Buffer headers.  Please update
#error your headers.
#endif
#if 2005000 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
#error This file was generated by an older version of protoc which is
#error incompatible with your Protocol Buffer headers.  Please
#error regenerate this file with a newer version of protoc.
#endif#include <google/protobuf/generated_message_util.h>
#include <google/protobuf/message.h>
#include <google/protobuf/repeated_field.h>
#include <google/protobuf/extension_set.h>
#include <google/protobuf/unknown_field_set.h>
// @@protoc_insertion_point(includes)namespace contacts {// Internal implementation detail -- do not call these.
void  protobuf_AddDesc_hello_2eproto();
void protobuf_AssignDesc_hello_2eproto();
void protobuf_ShutdownFile_hello_2eproto();class PeopleInfo;// ===================================================================class PeopleInfo : public ::google::protobuf::Message {public:PeopleInfo();virtual ~PeopleInfo();PeopleInfo(const PeopleInfo& from);inline PeopleInfo& operator=(const PeopleInfo& from) {CopyFrom(from);return *this;}inline const ::google::protobuf::UnknownFieldSet& unknown_fields() const {return _unknown_fields_;}inline ::google::protobuf::UnknownFieldSet* mutable_unknown_fields() {return &_unknown_fields_;}static const ::google::protobuf::Descriptor* descriptor();static const PeopleInfo& default_instance();void Swap(PeopleInfo* other);// implements Message ----------------------------------------------PeopleInfo* New() const;void CopyFrom(const ::google::protobuf::Message& from);void MergeFrom(const ::google::protobuf::Message& from);void CopyFrom(const PeopleInfo& from);void MergeFrom(const PeopleInfo& from);void Clear();bool IsInitialized() const;int ByteSize() const;bool MergePartialFromCodedStream(::google::protobuf::io::CodedInputStream* input);void SerializeWithCachedSizes(::google::protobuf::io::CodedOutputStream* output) const;::google::protobuf::uint8* SerializeWithCachedSizesToArray(::google::protobuf::uint8* output) const;int GetCachedSize() const { return _cached_size_; }private:void SharedCtor();void SharedDtor();void SetCachedSize(int size) const;public:::google::protobuf::Metadata GetMetadata() const;// nested types ----------------------------------------------------// accessors -------------------------------------------------------// required string name = 1;inline bool has_name() const;inline void clear_name();static const int kNameFieldNumber = 1;inline const ::std::string& name() const;inline void set_name(const ::std::string& value);inline void set_name(const char* value);inline void set_name(const char* value, size_t size);inline ::std::string* mutable_name();inline ::std::string* release_name();inline void set_allocated_name(::std::string* name);// required int32 age = 2;inline bool has_age() const;inline void clear_age();static const int kAgeFieldNumber = 2;inline ::google::protobuf::int32 age() const;inline void set_age(::google::protobuf::int32 value);// required string sex = 3;inline bool has_sex() const;inline void clear_sex();static const int kSexFieldNumber = 3;inline const ::std::string& sex() const;inline void set_sex(const ::std::string& value);inline void set_sex(const char* value);inline void set_sex(const char* value, size_t size);inline ::std::string* mutable_sex();inline ::std::string* release_sex();inline void set_allocated_sex(::std::string* sex);// @@protoc_insertion_point(class_scope:contacts.PeopleInfo)private:inline void set_has_name();inline void clear_has_name();inline void set_has_age();inline void clear_has_age();inline void set_has_sex();inline void clear_has_sex();::google::protobuf::UnknownFieldSet _unknown_fields_;::std::string* name_;::std::string* sex_;::google::protobuf::int32 age_;mutable int _cached_size_;::google::protobuf::uint32 _has_bits_[(3 + 31) / 32];friend void  protobuf_AddDesc_hello_2eproto();friend void protobuf_AssignDesc_hello_2eproto();friend void protobuf_ShutdownFile_hello_2eproto();void InitAsDefaultInstance();static PeopleInfo* default_instance_;
};
// ===================================================================// ===================================================================// PeopleInfo// required string name = 1;
inline bool PeopleInfo::has_name() const {return (_has_bits_[0] & 0x00000001u) != 0;
}
inline void PeopleInfo::set_has_name() {_has_bits_[0] |= 0x00000001u;
}
inline void PeopleInfo::clear_has_name() {_has_bits_[0] &= ~0x00000001u;
}
inline void PeopleInfo::clear_name() {if (name_ != &::google::protobuf::internal::kEmptyString) {name_->clear();}clear_has_name();
}
inline const ::std::string& PeopleInfo::name() const {return *name_;
}
inline void PeopleInfo::set_name(const ::std::string& value) {set_has_name();if (name_ == &::google::protobuf::internal::kEmptyString) {name_ = new ::std::string;}name_->assign(value);
}
inline void PeopleInfo::set_name(const char* value) {set_has_name();if (name_ == &::google::protobuf::internal::kEmptyString) {name_ = new ::std::string;}name_->assign(value);
}
inline void PeopleInfo::set_name(const char* value, size_t size) {set_has_name();if (name_ == &::google::protobuf::internal::kEmptyString) {name_ = new ::std::string;}name_->assign(reinterpret_cast<const char*>(value), size);
}
inline ::std::string* PeopleInfo::mutable_name() {set_has_name();if (name_ == &::google::protobuf::internal::kEmptyString) {name_ = new ::std::string;}return name_;
}
inline ::std::string* PeopleInfo::release_name() {clear_has_name();if (name_ == &::google::protobuf::internal::kEmptyString) {return NULL;} else {::std::string* temp = name_;name_ = const_cast< ::std::string*>(&::google::protobuf::internal::kEmptyString);return temp;}
}
inline void PeopleInfo::set_allocated_name(::std::string* name) {if (name_ != &::google::protobuf::internal::kEmptyString) {delete name_;}if (name) {set_has_name();name_ = name;} else {clear_has_name();name_ = const_cast< ::std::string*>(&::google::protobuf::internal::kEmptyString);}
}// required int32 age = 2;
inline bool PeopleInfo::has_age() const {return (_has_bits_[0] & 0x00000002u) != 0;
}
inline void PeopleInfo::set_has_age() {_has_bits_[0] |= 0x00000002u;
}
inline void PeopleInfo::clear_has_age() {_has_bits_[0] &= ~0x00000002u;
}
inline void PeopleInfo::clear_age() {age_ = 0;clear_has_age();
}
inline ::google::protobuf::int32 PeopleInfo::age() const {return age_;
}
inline void PeopleInfo::set_age(::google::protobuf::int32 value) {set_has_age();age_ = value;
}// required string sex = 3;
inline bool PeopleInfo::has_sex() const {return (_has_bits_[0] & 0x00000004u) != 0;
}
inline void PeopleInfo::set_has_sex() {_has_bits_[0] |= 0x00000004u;
}
inline void PeopleInfo::clear_has_sex() {_has_bits_[0] &= ~0x00000004u;
}
inline void PeopleInfo::clear_sex() {if (sex_ != &::google::protobuf::internal::kEmptyString) {sex_->clear();}clear_has_sex();
}
inline const ::std::string& PeopleInfo::sex() const {return *sex_;
}
inline void PeopleInfo::set_sex(const ::std::string& value) {set_has_sex();if (sex_ == &::google::protobuf::internal::kEmptyString) {sex_ = new ::std::string;}sex_->assign(value);
}
inline void PeopleInfo::set_sex(const char* value) {set_has_sex();if (sex_ == &::google::protobuf::internal::kEmptyString) {sex_ = new ::std::string;}sex_->assign(value);
}
inline void PeopleInfo::set_sex(const char* value, size_t size) {set_has_sex();if (sex_ == &::google::protobuf::internal::kEmptyString) {sex_ = new ::std::string;}sex_->assign(reinterpret_cast<const char*>(value), size);
}
inline ::std::string* PeopleInfo::mutable_sex() {set_has_sex();if (sex_ == &::google::protobuf::internal::kEmptyString) {sex_ = new ::std::string;}return sex_;
}
inline ::std::string* PeopleInfo::release_sex() {clear_has_sex();if (sex_ == &::google::protobuf::internal::kEmptyString) {return NULL;} else {::std::string* temp = sex_;sex_ = const_cast< ::std::string*>(&::google::protobuf::internal::kEmptyString);return temp;}
}
inline void PeopleInfo::set_allocated_sex(::std::string* sex) {if (sex_ != &::google::protobuf::internal::kEmptyString) {delete sex_;}if (sex) {set_has_sex();sex_ = sex;} else {clear_has_sex();sex_ = const_cast< ::std::string*>(&::google::protobuf::internal::kEmptyString);}
}// @@protoc_insertion_point(namespace_scope)}  // namespace contacts#ifndef SWIG
namespace google {
namespace protobuf {}  // namespace google
}  // namespace protobuf
#endif  // SWIG// @@protoc_insertion_point(global_scope)#endif  // PROTOBUF_hello_2eproto__INCLUDED

（2）.cc文件

// Generated by the protocol buffer compiler.  DO NOT EDIT!
// source: hello.proto#define INTERNAL_SUPPRESS_PROTOBUF_FIELD_DEPRECATION
#include "hello.pb.h"#include <algorithm>#include <google/protobuf/stubs/common.h>
#include <google/protobuf/stubs/once.h>
#include <google/protobuf/io/coded_stream.h>
#include <google/protobuf/wire_format_lite_inl.h>
#include <google/protobuf/descriptor.h>
#include <google/protobuf/generated_message_reflection.h>
#include <google/protobuf/reflection_ops.h>
#include <google/protobuf/wire_format.h>
// @@protoc_insertion_point(includes)namespace contacts {namespace {const ::google::protobuf::Descriptor* PeopleInfo_descriptor_ = NULL;
const ::google::protobuf::internal::GeneratedMessageReflection*PeopleInfo_reflection_ = NULL;}  // namespacevoid protobuf_AssignDesc_hello_2eproto() {protobuf_AddDesc_hello_2eproto();const ::google::protobuf::FileDescriptor* file =::google::protobuf::DescriptorPool::generated_pool()->FindFileByName("hello.proto");GOOGLE_CHECK(file != NULL);PeopleInfo_descriptor_ = file->message_type(0);static const int PeopleInfo_offsets_[3] = {GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET(PeopleInfo, name_),GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET(PeopleInfo, age_),GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET(PeopleInfo, sex_),};PeopleInfo_reflection_ =new ::google::protobuf::internal::GeneratedMessageReflection(PeopleInfo_descriptor_,PeopleInfo::default_instance_,PeopleInfo_offsets_,GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET(PeopleInfo, _has_bits_[0]),GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET(PeopleInfo, _unknown_fields_),-1,::google::protobuf::DescriptorPool::generated_pool(),::google::protobuf::MessageFactory::generated_factory(),sizeof(PeopleInfo));
}namespace {GOOGLE_PROTOBUF_DECLARE_ONCE(protobuf_AssignDescriptors_once_);
inline void protobuf_AssignDescriptorsOnce() {::google::protobuf::GoogleOnceInit(&protobuf_AssignDescriptors_once_,&protobuf_AssignDesc_hello_2eproto);
}void protobuf_RegisterTypes(const ::std::string&) {protobuf_AssignDescriptorsOnce();::google::protobuf::MessageFactory::InternalRegisterGeneratedMessage(PeopleInfo_descriptor_, &PeopleInfo::default_instance());
}}  // namespacevoid protobuf_ShutdownFile_hello_2eproto() {delete PeopleInfo::default_instance_;delete PeopleInfo_reflection_;
}void protobuf_AddDesc_hello_2eproto() {static bool already_here = false;if (already_here) return;already_here = true;GOOGLE_PROTOBUF_VERIFY_VERSION;::google::protobuf::DescriptorPool::InternalAddGeneratedFile("\n\013hello.proto\022\010contacts\"4\n\nPeopleInfo\022\014\n""\004name\030\001 \002(\t\022\013\n\003age\030\002 \002(\005\022\013\n\003sex\030\003 \002(\t", 77);::google::protobuf::MessageFactory::InternalRegisterGeneratedFile("hello.proto", &protobuf_RegisterTypes);PeopleInfo::default_instance_ = new PeopleInfo();PeopleInfo::default_instance_->InitAsDefaultInstance();::google::protobuf::internal::OnShutdown(&protobuf_ShutdownFile_hello_2eproto);
}// Force AddDescriptors() to be called at static initialization time.
struct StaticDescriptorInitializer_hello_2eproto {StaticDescriptorInitializer_hello_2eproto() {protobuf_AddDesc_hello_2eproto();}
} static_descriptor_initializer_hello_2eproto_;// ===================================================================#ifndef _MSC_VER
const int PeopleInfo::kNameFieldNumber;
const int PeopleInfo::kAgeFieldNumber;
const int PeopleInfo::kSexFieldNumber;
#endif  // !_MSC_VERPeopleInfo::PeopleInfo(): ::google::protobuf::Message() {SharedCtor();
}void PeopleInfo::InitAsDefaultInstance() {
}PeopleInfo::PeopleInfo(const PeopleInfo& from): ::google::protobuf::Message() {SharedCtor();MergeFrom(from);
}void PeopleInfo::SharedCtor() {_cached_size_ = 0;name_ = const_cast< ::std::string*>(&::google::protobuf::internal::kEmptyString);age_ = 0;sex_ = const_cast< ::std::string*>(&::google::protobuf::internal::kEmptyString);::memset(_has_bits_, 0, sizeof(_has_bits_));
}PeopleInfo::~PeopleInfo() {SharedDtor();
}void PeopleInfo::SharedDtor() {if (name_ != &::google::protobuf::internal::kEmptyString) {delete name_;}if (sex_ != &::google::protobuf::internal::kEmptyString) {delete sex_;}if (this != default_instance_) {}
}void PeopleInfo::SetCachedSize(int size) const {GOOGLE_SAFE_CONCURRENT_WRITES_BEGIN();_cached_size_ = size;GOOGLE_SAFE_CONCURRENT_WRITES_END();
}
const ::google::protobuf::Descriptor* PeopleInfo::descriptor() {protobuf_AssignDescriptorsOnce();return PeopleInfo_descriptor_;
}const PeopleInfo& PeopleInfo::default_instance() {if (default_instance_ == NULL) protobuf_AddDesc_hello_2eproto();return *default_instance_;
}PeopleInfo* PeopleInfo::default_instance_ = NULL;PeopleInfo* PeopleInfo::New() const {return new PeopleInfo;
}void PeopleInfo::Clear() {if (_has_bits_[0 / 32] & (0xffu << (0 % 32))) {if (has_name()) {if (name_ != &::google::protobuf::internal::kEmptyString) {name_->clear();}}age_ = 0;if (has_sex()) {if (sex_ != &::google::protobuf::internal::kEmptyString) {sex_->clear();}}}::memset(_has_bits_, 0, sizeof(_has_bits_));mutable_unknown_fields()->Clear();
}bool PeopleInfo::MergePartialFromCodedStream(::google::protobuf::io::CodedInputStream* input) {
#define DO_(EXPRESSION) if (!(EXPRESSION)) return false::google::protobuf::uint32 tag;while ((tag = input->ReadTag()) != 0) {switch (::google::protobuf::internal::WireFormatLite::GetTagFieldNumber(tag)) {// required string name = 1;case 1: {if (::google::protobuf::internal::WireFormatLite::GetTagWireType(tag) ==::google::protobuf::internal::WireFormatLite::WIRETYPE_LENGTH_DELIMITED) {DO_(::google::protobuf::internal::WireFormatLite::ReadString(input, this->mutable_name()));::google::protobuf::internal::WireFormat::VerifyUTF8String(this->name().data(), this->name().length(),::google::protobuf::internal::WireFormat::PARSE);} else {goto handle_uninterpreted;}if (input->ExpectTag(16)) goto parse_age;break;}// required int32 age = 2;case 2: {if (::google::protobuf::internal::WireFormatLite::GetTagWireType(tag) ==::google::protobuf::internal::WireFormatLite::WIRETYPE_VARINT) {parse_age:DO_((::google::protobuf::internal::WireFormatLite::ReadPrimitive<::google::protobuf::int32, ::google::protobuf::internal::WireFormatLite::TYPE_INT32>(input, &age_)));set_has_age();} else {goto handle_uninterpreted;}if (input->ExpectTag(26)) goto parse_sex;break;}// required string sex = 3;case 3: {if (::google::protobuf::internal::WireFormatLite::GetTagWireType(tag) ==::google::protobuf::internal::WireFormatLite::WIRETYPE_LENGTH_DELIMITED) {parse_sex:DO_(::google::protobuf::internal::WireFormatLite::ReadString(input, this->mutable_sex()));::google::protobuf::internal::WireFormat::VerifyUTF8String(this->sex().data(), this->sex().length(),::google::protobuf::internal::WireFormat::PARSE);} else {goto handle_uninterpreted;}if (input->ExpectAtEnd()) return true;break;}default: {handle_uninterpreted:if (::google::protobuf::internal::WireFormatLite::GetTagWireType(tag) ==::google::protobuf::internal::WireFormatLite::WIRETYPE_END_GROUP) {return true;}DO_(::google::protobuf::internal::WireFormat::SkipField(input, tag, mutable_unknown_fields()));break;}}}return true;
#undef DO_
}void PeopleInfo::SerializeWithCachedSizes(::google::protobuf::io::CodedOutputStream* output) const {// required string name = 1;if (has_name()) {::google::protobuf::internal::WireFormat::VerifyUTF8String(this->name().data(), this->name().length(),::google::protobuf::internal::WireFormat::SERIALIZE);::google::protobuf::internal::WireFormatLite::WriteString(1, this->name(), output);}// required int32 age = 2;if (has_age()) {::google::protobuf::internal::WireFormatLite::WriteInt32(2, this->age(), output);}// required string sex = 3;if (has_sex()) {::google::protobuf::internal::WireFormat::VerifyUTF8String(this->sex().data(), this->sex().length(),::google::protobuf::internal::WireFormat::SERIALIZE);::google::protobuf::internal::WireFormatLite::WriteString(3, this->sex(), output);}if (!unknown_fields().empty()) {::google::protobuf::internal::WireFormat::SerializeUnknownFields(unknown_fields(), output);}
}::google::protobuf::uint8* PeopleInfo::SerializeWithCachedSizesToArray(::google::protobuf::uint8* target) const {// required string name = 1;if (has_name()) {::google::protobuf::internal::WireFormat::VerifyUTF8String(this->name().data(), this->name().length(),::google::protobuf::internal::WireFormat::SERIALIZE);target =::google::protobuf::internal::WireFormatLite::WriteStringToArray(1, this->name(), target);}// required int32 age = 2;if (has_age()) {target = ::google::protobuf::internal::WireFormatLite::WriteInt32ToArray(2, this->age(), target);}// required string sex = 3;if (has_sex()) {::google::protobuf::internal::WireFormat::VerifyUTF8String(this->sex().data(), this->sex().length(),::google::protobuf::internal::WireFormat::SERIALIZE);target =::google::protobuf::internal::WireFormatLite::WriteStringToArray(3, this->sex(), target);}if (!unknown_fields().empty()) {target = ::google::protobuf::internal::WireFormat::SerializeUnknownFieldsToArray(unknown_fields(), target);}return target;
}int PeopleInfo::ByteSize() const {int total_size = 0;if (_has_bits_[0 / 32] & (0xffu << (0 % 32))) {// required string name = 1;if (has_name()) {total_size += 1 +::google::protobuf::internal::WireFormatLite::StringSize(this->name());}// required int32 age = 2;if (has_age()) {total_size += 1 +::google::protobuf::internal::WireFormatLite::Int32Size(this->age());}// required string sex = 3;if (has_sex()) {total_size += 1 +::google::protobuf::internal::WireFormatLite::StringSize(this->sex());}}if (!unknown_fields().empty()) {total_size +=::google::protobuf::internal::WireFormat::ComputeUnknownFieldsSize(unknown_fields());}GOOGLE_SAFE_CONCURRENT_WRITES_BEGIN();_cached_size_ = total_size;GOOGLE_SAFE_CONCURRENT_WRITES_END();return total_size;
}void PeopleInfo::MergeFrom(const ::google::protobuf::Message& from) {GOOGLE_CHECK_NE(&from, this);const PeopleInfo* source =::google::protobuf::internal::dynamic_cast_if_available<const PeopleInfo*>(&from);if (source == NULL) {::google::protobuf::internal::ReflectionOps::Merge(from, this);} else {MergeFrom(*source);}
}void PeopleInfo::MergeFrom(const PeopleInfo& from) {GOOGLE_CHECK_NE(&from, this);if (from._has_bits_[0 / 32] & (0xffu << (0 % 32))) {if (from.has_name()) {set_name(from.name());}if (from.has_age()) {set_age(from.age());}if (from.has_sex()) {set_sex(from.sex());}}mutable_unknown_fields()->MergeFrom(from.unknown_fields());
}void PeopleInfo::CopyFrom(const ::google::protobuf::Message& from) {if (&from == this) return;Clear();MergeFrom(from);
}void PeopleInfo::CopyFrom(const PeopleInfo& from) {if (&from == this) return;Clear();MergeFrom(from);
}bool PeopleInfo::IsInitialized() const {if ((_has_bits_[0] & 0x00000007) != 0x00000007) return false;return true;
}void PeopleInfo::Swap(PeopleInfo* other) {if (other != this) {std::swap(name_, other->name_);std::swap(age_, other->age_);std::swap(sex_, other->sex_);std::swap(_has_bits_[0], other->_has_bits_[0]);_unknown_fields_.Swap(&other->_unknown_fields_);std::swap(_cached_size_, other->_cached_size_);}
}::google::protobuf::Metadata PeopleInfo::GetMetadata() const {protobuf_AssignDescriptorsOnce();::google::protobuf::Metadata metadata;metadata.descriptor = PeopleInfo_descriptor_;metadata.reflection = PeopleInfo_reflection_;return metadata;
}// @@protoc_insertion_point(namespace_scope)}  // namespace contacts// @@protoc_insertion_point(global_scope)

4.c++代码块编写

#include <iostream>
#include <fstream>
#include <string>
#include "hello.pb.h"
using namespace std;int main(int argc, char* argv[]) {string people_str; contacts::PeopleInfo people; people.set_age(20); people.set_name("zhangsan"); people.set_sex("nan"); // 调⽤序列化⽅法，将序列化后的⼆进制序列存⼊string中if (!people.SerializeToString(&people_str))cout << "序列化联系⼈失败." << endl; contacts::PeopleInfo peoplere; // 调⽤反序列化⽅法，读取string中存放的⼆进制序列，并反序列化出对象if (!peoplere.ParseFromString(people_str))cout << "反序列化出联系⼈失败." << endl; cout<< peoplere.name()<< " | " <<peoplere.age()<< " | " <<peoplere.sex()<<endl;return 0;
}

5.编译执行的序列化结果


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