《微服务实战》刘金亮 13.22 protobuf 简单使用 例子

 

test.proto

syntax = "proto3";
package protocol;
option go_package =".";
enum FOO
{
  X=0;
};

message UserInfo {
  string message = 1;
  int32 length = 2;
}

 

 

注意：

option go_package ="."; 是制定路径，不然会报如下错误

Please specify either:
        • a "go_package" option in the .proto source file, or
        • a "M" argument on the command line.

See https://developers.google.com/protocol-buffers/docs/reference/go-generated#package for more information.    

--go_out: protoc-gen-go: Plugin failed with status code 1.

 

执行命令

protoc --go_out=. test.proto 

 

当前文件夹下生成如下文件代码

test.pb.go

// Code generated by protoc-gen-go. DO NOT EDIT.
// versions:
//     protoc-gen-go v1.28.0
//     protoc        v3.19.4
// source: test.proto

package __

import (
    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)
)

type FOO int32

const (
    FOO_X FOO = 0
)

// Enum value maps for FOO.
var (
    FOO_name = map[int32]string{
        0: "X",
    }
    FOO_value = map[string]int32{
        "X": 0,
    }
)

func (x FOO) Enum() *FOO {
    p := new(FOO)
    *p = x
    return p
}

func (x FOO) String() string {
    return protoimpl.X.EnumStringOf(x.Descriptor(), protoreflect.EnumNumber(x))
}

func (FOO) Descriptor() protoreflect.EnumDescriptor {
    return file_test_proto_enumTypes[0].Descriptor()
}

func (FOO) Type() protoreflect.EnumType {
    return &file_test_proto_enumTypes[0]
}

func (x FOO) Number() protoreflect.EnumNumber {
    return protoreflect.EnumNumber(x)
}

// Deprecated: Use FOO.Descriptor instead.
func (FOO) EnumDescriptor() ([]byte, []int) {
    return file_test_proto_rawDescGZIP(), []int{0}
}

type UserInfo struct {
    state         protoimpl.MessageState
    sizeCache     protoimpl.SizeCache
    unknownFields protoimpl.UnknownFields

    Message string `protobuf:"bytes,1,opt,name=message,proto3" json:"message,omitempty"`
    Length  int32  `protobuf:"varint,2,opt,name=length,proto3" json:"length,omitempty"`
}

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

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

func (*UserInfo) ProtoMessage() {}

func (x *UserInfo) ProtoReflect() protoreflect.Message {
    mi := &file_test_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 UserInfo.ProtoReflect.Descriptor instead.
func (*UserInfo) Descriptor() ([]byte, []int) {
    return file_test_proto_rawDescGZIP(), []int{0}
}

func (x *UserInfo) GetMessage() string {
    if x != nil {
        return x.Message
    }
    return ""
}

func (x *UserInfo) GetLength() int32 {
    if x != nil {
        return x.Length
    }
    return 0
}

var File_test_proto protoreflect.FileDescriptor

var file_test_proto_rawDesc = []byte{
    0x0a, 0x0a, 0x74, 0x65, 0x73, 0x74, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x12, 0x08, 0x70, 0x72,
    0x6f, 0x74, 0x6f, 0x63, 0x6f, 0x6c, 0x22, 0x3c, 0x0a, 0x08, 0x55, 0x73, 0x65, 0x72, 0x49, 0x6e,
    0x66, 0x6f, 0x12, 0x18, 0x0a, 0x07, 0x6d, 0x65, 0x73, 0x73, 0x61, 0x67, 0x65, 0x18, 0x01, 0x20,
    0x01, 0x28, 0x09, 0x52, 0x07, 0x6d, 0x65, 0x73, 0x73, 0x61, 0x67, 0x65, 0x12, 0x16, 0x0a, 0x06,
    0x6c, 0x65, 0x6e, 0x67, 0x74, 0x68, 0x18, 0x02, 0x20, 0x01, 0x28, 0x05, 0x52, 0x06, 0x6c, 0x65,
    0x6e, 0x67, 0x74, 0x68, 0x2a, 0x0c, 0x0a, 0x03, 0x46, 0x4f, 0x4f, 0x12, 0x05, 0x0a, 0x01, 0x58,
    0x10, 0x00, 0x42, 0x03, 0x5a, 0x01, 0x2e, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
}

var (
    file_test_proto_rawDescOnce sync.Once
    file_test_proto_rawDescData = file_test_proto_rawDesc
)

func file_test_proto_rawDescGZIP() []byte {
    file_test_proto_rawDescOnce.Do(func() {
        file_test_proto_rawDescData = protoimpl.X.CompressGZIP(file_test_proto_rawDescData)
    })
    return file_test_proto_rawDescData
}

var file_test_proto_enumTypes = make([]protoimpl.EnumInfo, 1)
var file_test_proto_msgTypes = make([]protoimpl.MessageInfo, 1)
var file_test_proto_goTypes = []interface{}{
    (FOO)(0),         // 0: protocol.FOO
    (*UserInfo)(nil), // 1: protocol.UserInfo
}
var file_test_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_test_proto_init() }
func file_test_proto_init() {
    if File_test_proto != nil {
        return
    }
    if !protoimpl.UnsafeEnabled {
        file_test_proto_msgTypes[0].Exporter = func(v interface{}, i int) interface{} {
            switch v := v.(*UserInfo); 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_test_proto_rawDesc,
            NumEnums:      1,
            NumMessages:   1,
            NumExtensions: 0,
            NumServices:   0,
        },
        GoTypes:           file_test_proto_goTypes,
        DependencyIndexes: file_test_proto_depIdxs,
        EnumInfos:         file_test_proto_enumTypes,
        MessageInfos:      file_test_proto_msgTypes,
    }.Build()
    File_test_proto = out.File
    file_test_proto_rawDesc = nil
    file_test_proto_goTypes = nil
    file_test_proto_depIdxs = nil
}

 

调用生成的文件

 

main.go

 

package main

import (
    "github.com/golang/protobuf/proto"
    "log"
    pr "protobuf_demo/protofile"
)

func main() {
    u := &pr.UserInfo{
        Message: *proto.String("testInfo"),
        Length:  *proto.Int32(10),
    }

    data, err := proto.Marshal(u)
    if err != nil {
        log.Fatal("marshalling error:", err)
    }
    newInfo := &pr.UserInfo{}
    err = proto.Unmarshal(data, newInfo)
    if err != nil {
        log.Fatal("unmarshaling error:", err)
    }

    log.Println(newInfo.GetMessage())

}

 

 

运行输出

2022/05/09 15:38:50 testInfo