Go Generated Code Guide (Open)

go install google.golang.org/protobuf/cmd/protoc-gen-go@latest

protoc --proto_path=src --go_out=out --go_opt=paths=source_relative foo.proto bar/baz.proto

option go_package = "example.com/project/protos/fizz";

protoc --proto_path=src \
  --go_opt=Mprotos/buzz.proto=example.com/project/protos/fizz \
  --go_opt=Mprotos/bar.proto=example.com/project/protos/foo \
  protos/buzz.proto protos/bar.proto

`.proto`-Syntax	API-Level
proto2	Open Struct API
proto3	Open Struct API
Edition 2023	Open Struct API
Edition 2024+	Opaque API

edition = "2023";

package log;

import "google/protobuf/go_features.proto";
option features.(pb.go).api_level = API_OPAQUE;

message LogEntry { … }

protoc […] --go_opt=default_api_level=API_HYBRID

protoc […] --go_opt=apilevelMhello.proto=API_HYBRID

message Artist {}

message Artist {
  message Name {
  }
}

int32 birth_year = 1;

int32 birth_year = 1;

message Band {}

// proto2
message Concert {
  optional Band headliner = 1;
  // The generated code is the same result if required instead of optional.
}

// proto3
message Concert {
  Band headliner = 1;
}

// editions
message Concer {
  Band headliner = 1;
}

type Concert struct {
    Headliner *Band
}

var m *Concert // defaults to nil
log.Infof("GetFoundingYear() = %d (no panic!)", m.GetHeadliner().GetFoundingYear())

message Concert {
  // Best practice: use pluralized names for repeated fields:
  // /programming-guides/style#repeated-fields
  repeated Band support_acts = 1;
}

type Concert struct {
    SupportActs []*Band
}

concert := &Concert{
  SupportActs: []*Band{
    {}, // First element.
    {}, // Second element.
  },
}

support := concert.GetSupportActs() // support type is []*Band.
b1 := support[0] // b1 type is *Band, the first element in support_acts.

message MerchItem {}

message MerchBooth {
  // items maps from merchandise item name ("Signed T-Shirt") to
  // a MerchItem message with more details about the item.
  map<string, MerchItem> items = 1;
}

type MerchBooth struct {
    Items map[string]*MerchItem
}

package account;
message Profile {
  oneof avatar {
    string image_url = 1;
    bytes image_data = 2;
  }
}

type Profile struct {
    // Types that are valid to be assigned to Avatar:
    //  *Profile_ImageUrl
    //  *Profile_ImageData
    Avatar isProfile_Avatar `protobuf_oneof:"avatar"`
}

type Profile_ImageUrl struct {
        ImageUrl string
}
type Profile_ImageData struct {
        ImageData []byte
}

p1 := &account.Profile{
  Avatar: &account.Profile_ImageUrl{ImageUrl: "http://example.com/image.png"},
}

// imageData is []byte
imageData := getImageData()
p2 := &account.Profile{
  Avatar: &account.Profile_ImageData{ImageData: imageData},
}

switch x := m.Avatar.(type) {
case *account.Profile_ImageUrl:
    // Load profile image based on URL
    // using x.ImageUrl
case *account.Profile_ImageData:
    // Load profile image based on bytes
    // using x.ImageData
case nil:
    // The field is not set.
default:
    return fmt.Errorf("Profile.Avatar has unexpected type %T", x)
}

message Venue {
  enum Kind {
    KIND_UNSPECIFIED = 0;
    KIND_CONCERT_HALL = 1;
    KIND_STADIUM = 2;
    KIND_BAR = 3;
    KIND_OPEN_AIR_FESTIVAL = 4;
  }
  Kind kind = 1;
  // ...
}

type Venue_Kind int32

const (
    Venue_KIND_UNSPECIFIED       Venue_Kind = 0
    Venue_KIND_CONCERT_HALL      Venue_Kind = 1
    Venue_KIND_STADIUM           Venue_Kind = 2
    Venue_KIND_BAR               Venue_Kind = 3
    Venue_KIND_OPEN_AIR_FESTIVAL Venue_Kind = 4
)

type Venue_Kind int32

enum Genre {
  GENRE_UNSPECIFIED = 0;
  GENRE_ROCK = 1;
  GENRE_INDIE = 2;
  GENRE_DRUM_AND_BASS = 3;
  // ...
}

type Genre int32

func (Genre) Enum() *Genre

const (
    Venue_KIND_UNSPECIFIED       Venue_Kind = 0
    Venue_KIND_CONCERT_HALL      Venue_Kind = 1
    Venue_KIND_STADIUM           Venue_Kind = 2
    Venue_KIND_BAR               Venue_Kind = 3
    Venue_KIND_OPEN_AIR_FESTIVAL Venue_Kind = 4
)

const (
    Genre_GENRE_UNSPECIFIED   Genre = 0
    Genre_GENRE_ROCK          Genre = 1
    Genre_GENRE_INDIE         Genre = 2
    Genre_GENRE_DRUM_AND_BASS Genre = 3
)

var Genre_name = map[int32]string{
    0: "GENRE_UNSPECIFIED",
    1: "GENRE_ROCK",
    2: "GENRE_INDIE",
    3: "GENRE_DRUM_AND_BASS",
}
var Genre_value = map[string]int32{
    "GENRE_UNSPECIFIED":   0,
    "GENRE_ROCK":          1,
    "GENRE_INDIE":         2,
    "GENRE_DRUM_AND_BASS": 3,
}

extend Concert {
  int32 promo_id = 123;
}

extend Concert {
  int32 singular_int32 = 1;
  repeated bytes repeated_strings = 2;
  Band singular_message = 3;
}

m := &somepb.Concert{}
proto.SetExtension(m, extpb.E_SingularInt32, int32(1))
proto.SetExtension(m, extpb.E_RepeatedString, []string{"a", "b", "c"})
proto.SetExtension(m, extpb.E_SingularMessage, &extpb.Band{})

v1 := proto.GetExtension(m, extpb.E_SingularInt32).(int32)
v2 := proto.GetExtension(m, extpb.E_RepeatedString).([][]byte)
v3 := proto.GetExtension(m, extpb.E_SingularMessage).(*extpb.Band)

message Promo {
  extend Concert {
    int32 promo_id = 124;
  }
}

Hinweis

Compiler-Aufruf

Pakete (Packages)

API-Level

Nachrichten

Verschachtelte Typen

Felder

Singuläre explizite Präsenz Skalarfelder

Singuläre implizite Präsenz Skalarfelder

Singuläre Nachrichtenfelder

Wiederholte Felder

Map-Felder

Oneof-Felder

Aufzählungen (Enums)

Erweiterungen (Extensions)

Services