Golang Protobuf

https://www.jianshu.com/p/2081bfb4979d

>![](https://upload-images.jianshu.io/upload_images/47789-e14b062c2ed9daa1.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)

## 编译安装编译器protoc

```
wget https://github.com/protocolbuffers/protobuf/releases/download/v2.6.1/protobuf-2.6.1.zip
unzip protobuf-2.6.1.zip
cd protobuf-2.6.1

./configure CC=clang CXX=clang++ CXXFLAGS='-std=c++11 -stdlib=libc++ -O3 -g' LDFLAGS='-stdlib=libc++' LIBS="-lc++ -lc++abi"

make -j 4 
sudo make install
protoc --version
```

## 安装插件

`go get -u github.com/golang/protobuf/protoc-gen-go`

## 定义消息类型

```
// student.proto
syntax = "proto3";
package main;

// this is a comment
message Student {
  string name = 1;
  bool male = 2;
  repeated int32 scores = 3;
}
```

在当前目录下执行：

```bash
protoc --go_out=. *.proto

ls
# student.pb.go  student.proto
```
protoc 生成的代码：

```golang
// student.pb.go
package proto

import (
	proto "github.com/golang/protobuf/proto"
	protoreflect "google.golang.org/protobuf/reflect/protoreflect"
	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
	reflect "reflect"
	sync "sync"
)

const (
	// Verify that this generated code is sufficiently up-to-date.
	_ = protoimpl.EnforceVersion(20 - protoimpl.MinVersion)
	// Verify that runtime/protoimpl is sufficiently up-to-date.
	_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
)

// This is a compile-time assertion that a sufficiently up-to-date version
// of the legacy proto package is being used.
const _ = proto.ProtoPackageIsVersion4

// this is a comment
type Student struct {
	state         protoimpl.MessageState
	sizeCache     protoimpl.SizeCache
	unknownFields protoimpl.UnknownFields

	Name   string  `protobuf:"bytes,1,opt,name=name,proto3" json:"name,omitempty"`
	Male   bool    `protobuf:"varint,2,opt,name=male,proto3" json:"male,omitempty"`
	Scores []int32 `protobuf:"varint,3,rep,packed,name=scores,proto3" json:"scores,omitempty"`
}

func (x *Student) Reset() {
	*x = Student{}
	if protoimpl.UnsafeEnabled {
		mi := &file_student_proto_msgTypes[0]
		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
		ms.StoreMessageInfo(mi)
	}
}

func (x *Student) String() string {
	return protoimpl.X.MessageStringOf(x)
}

func (*Student) ProtoMessage() {}

func (x *Student) ProtoReflect() protoreflect.Message {
	mi := &file_student_proto_msgTypes[0]
	if protoimpl.UnsafeEnabled && x != nil {
		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
		if ms.LoadMessageInfo() == nil {
			ms.StoreMessageInfo(mi)
		}
		return ms
	}
	return mi.MessageOf(x)
}

// Deprecated: Use Student.ProtoReflect.Descriptor instead.
func (*Student) Descriptor() ([]byte, []int) {
	return file_student_proto_rawDescGZIP(), []int{0}
}

func (x *Student) GetName() string {
	if x != nil {
		return x.Name
	}
	return ""
}

func (x *Student) GetMale() bool {
	if x != nil {
		return x.Male
	}
	return false
}

func (x *Student) GetScores() []int32 {
	if x != nil {
		return x.Scores
	}
	return nil
}

var File_student_proto protoreflect.FileDescriptor

var file_student_proto_rawDesc = []byte{
	0x0a, 0x0d, 0x73, 0x74, 0x75, 0x64, 0x65, 0x6e, 0x74, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x12,
	0x04, 0x6d, 0x61, 0x69, 0x6e, 0x22, 0x49, 0x0a, 0x07, 0x53, 0x74, 0x75, 0x64, 0x65, 0x6e, 0x74,
	0x12, 0x12, 0x0a, 0x04, 0x6e, 0x61, 0x6d, 0x65, 0x18, 0x01, 0x20, 0x01, 0x28, 0x09, 0x52, 0x04,
	0x6e, 0x61, 0x6d, 0x65, 0x12, 0x12, 0x0a, 0x04, 0x6d, 0x61, 0x6c, 0x65, 0x18, 0x02, 0x20, 0x01,
	0x28, 0x08, 0x52, 0x04, 0x6d, 0x61, 0x6c, 0x65, 0x12, 0x16, 0x0a, 0x06, 0x73, 0x63, 0x6f, 0x72,
	0x65, 0x73, 0x18, 0x03, 0x20, 0x03, 0x28, 0x05, 0x52, 0x06, 0x73, 0x63, 0x6f, 0x72, 0x65, 0x73,
	0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
}

var (
	file_student_proto_rawDescOnce sync.Once
	file_student_proto_rawDescData = file_student_proto_rawDesc
)

func file_student_proto_rawDescGZIP() []byte {
	file_student_proto_rawDescOnce.Do(func() {
		file_student_proto_rawDescData = protoimpl.X.CompressGZIP(file_student_proto_rawDescData)
	})
	return file_student_proto_rawDescData
}

var file_student_proto_msgTypes = make([]protoimpl.MessageInfo, 1)
var file_student_proto_goTypes = []interface{}{
	(*Student)(nil), // 0: main.Student
}
var file_student_proto_depIdxs = []int32{
	0, // [0:0] is the sub-list for method output_type
	0, // [0:0] is the sub-list for method input_type
	0, // [0:0] is the sub-list for extension type_name
	0, // [0:0] is the sub-list for extension extendee
	0, // [0:0] is the sub-list for field type_name
}

func init() { file_student_proto_init() }
func file_student_proto_init() {
	if File_student_proto != nil {
		return
	}
	if !protoimpl.UnsafeEnabled {
		file_student_proto_msgTypes[0].Exporter = func(v interface{}, i int) interface{} {
			switch v := v.(*Student); i {
			case 0:
				return &v.state
			case 1:
				return &v.sizeCache
			case 2:
				return &v.unknownFields
			default:
				return nil
			}
		}
	}
	type x struct{}
	out := protoimpl.TypeBuilder{
		File: protoimpl.DescBuilder{
			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
			RawDescriptor: file_student_proto_rawDesc,
			NumEnums:      0,
			NumMessages:   1,
			NumExtensions: 0,
			NumServices:   0,
		},
		GoTypes:           file_student_proto_goTypes,
		DependencyIndexes: file_student_proto_depIdxs,
		MessageInfos:      file_student_proto_msgTypes,
	}.Build()
	File_student_proto = out.File
	file_student_proto_rawDesc = nil
	file_student_proto_goTypes = nil
	file_student_proto_depIdxs = nil
}

```

---

参考：

https://gist.github.com/liushooter/44bd8e2f6f277f2631841787aafe3d9d

https://geektutu.com/post/quick-go-protobuf.html

https://colobu.com/2019/10/03/protobuf-ultimate-tutorial-in-go/

https://www.cnblogs.com/sanshengshui/p/9739521.html

http://yura415.github.io/js-protobuf-encode-decode/

https://zhuanlan.zhihu.com/p/147391981

https://zhuanlan.zhihu.com/p/95134068