proto3语法入门

syntax = "proto3";

/* SearchRequest represents a search query, with pagination options to
 * indicate which results to include in the response. */

message SearchRequest {
  string query = 1;
  int32 page_number = 2; // Which page number do we want?
  int32 result_per_page = 3;
}

<comment>

message  <message_name> {
  <filed_rule>  <filed_type> <filed_name> = <field_number> 
        类型         名称             编号  
}

message Foo {
  reserved 2, 15, 9 to 11;
  reserved "foo", "bar";
}

message String {
    string value = 1;
}

enum Corpus {
    UNIVERSAL = 0;
    WEB = 1;
    IMAGES = 2;
    LOCAL = 3;
    NEWS = 4;
    PRODUCTS = 5;
    VIDEO = 6;
}

enum <enum_name> {
    <element_name> = <element_number>
}

message MyMessage1 {
  enum EnumAllowingAlias {
    option allow_alias = true;
    UNKNOWN = 0;
    STARTED = 1;
    RUNNING = 1;
  }
}
message MyMessage2 {
  enum EnumNotAllowingAlias {
    UNKNOWN = 0;
    STARTED = 1;
    // RUNNING = 1;  // Uncommenting this line will cause a compile error inside Google and a warning message outside.
  }
}

enum Foo {
  reserved 2, 15, 9 to 11, 40 to max;
  reserved "FOO", "BAR";
}

message SearchResponse {
  repeated Result results = 1;
}

// 会编译为:
// type SearchResponse SearchResponse {
//    results []*Result
// }

map<string, Project> projects = 3;
// projects map[string, Project]

map<key_type, value_type> map_field = N;

message Sub1 {
    string name = 1;
}

message Sub2 {
    string name = 1;
}

message SampleMessage {
    oneof test_oneof {
        Sub1 sub1 = 1;
        Sub2 sub2 = 2;
    }
}

protoc -I=. --go_out=./pb --go_opt=module="gitee.com/infraboard/go-course/day21/pb" pb/oneof.proto

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

	// Types that are assignable to TestOneof:
	//	*SampleMessage_Sub1
	//	*SampleMessage_Sub2
	TestOneof isSampleMessage_TestOneof `protobuf_oneof:"test_oneof"`
}

of := &pb.SampleMessage{}
of.GetSub1()
of.GetSub2()

// 这里是应用其他的proto文件, 后面会讲 ipmort用法
import "google/protobuf/any.proto";

message ErrorStatus {
  string message = 1;
  repeated google.protobuf.Any details = 2;
}

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

	Message string       `protobuf:"bytes,1,opt,name=message,proto3" json:"message,omitempty"`
	Details []*anypb.Any `protobuf:"bytes,2,rep,name=details,proto3" json:"details,omitempty"`
}

// `Any` contains an arbitrary serialized protocol buffer message along with a
// URL that describes the type of the serialized message.
//
// Protobuf library provides support to pack/unpack Any values in the form
// of utility functions or additional generated methods of the Any type.
//  Example 4: Pack and unpack a message in Go
//
//      foo := &pb.Foo{...}
//      any, err := anypb.New(foo)
//      if err != nil {
//        ...
//      }
//      ...
//      foo := &pb.Foo{}
//      if err := any.UnmarshalTo(foo); err != nil {
//        ...
//      }
//
// The pack methods provided by protobuf library will by default use
// 'type.googleapis.com/full.type.name' as the type URL and the unpack
// methods only use the fully qualified type name after the last '/'
// in the type URL, for example "foo.bar.com/x/y.z" will yield type
// name "y.z".
//
//
// JSON
// ====
// The JSON representation of an `Any` value uses the regular
// representation of the deserialized, embedded message, with an
// additional field `@type` which contains the type URL. Example:
//
//     package google.profile;
//     message Person {
//       string first_name = 1;
//       string last_name = 2;
//     }
//
//     {
//       "@type": "type.googleapis.com/google.profile.Person",
//       "firstName": <string>,
//       "lastName": <string>
//     }
//
// If the embedded message type is well-known and has a custom JSON
// representation, that representation will be embedded adding a field
// `value` which holds the custom JSON in addition to the `@type`
// field. Example (for message [google.protobuf.Duration][]):
//
//     {
//       "@type": "type.googleapis.com/google.protobuf.Duration",
//       "value": "1.212s"
//     }
//
type Any struct {
	state         protoimpl.MessageState
	sizeCache     protoimpl.SizeCache
	unknownFields protoimpl.UnknownFields

  ...
	// Note: this functionality is not currently available in the official
	// protobuf release, and it is not used for type URLs beginning with
	// type.googleapis.com.
	//
	// Schemes other than `http`, `https` (or the empty scheme) might be
	// used with implementation specific semantics.
	//
	TypeUrl string `protobuf:"bytes,1,opt,name=type_url,json=typeUrl,proto3" json:"type_url,omitempty"`
	// Must be a valid serialized protocol buffer of the above specified type.
	Value []byte `protobuf:"bytes,2,opt,name=value,proto3" json:"value,omitempty"`
}

message Outer {                  // Level 0
  message MiddleAA {  // Level 1
    message Inner {   // Level 2
      int64 ival = 1;
      bool  booly = 2;
    }
  }
  message MiddleBB {  // Level 1
    message Inner {   // Level 2
      int32 ival = 1;
      bool  booly = 2;
    }
  }
}

// 这里是应用其他的proto文件, 后面会讲 ipmort用法
import "google/protobuf/any.proto";

import "myproject/other_protos.proto";

syntax = "proto3";

// 这里是应用其他的proto文件, 后面会讲 ipmort用法
import "google/protobuf/any.proto";

package hello;
option go_package="gitee.com/infraboard/go-course/day21/pb";

message ErrorStatus {
  string message = 1;
  repeated google.protobuf.Any details = 2;
}

syntax = "proto3";

// 由于这个文件的pkg 也叫hello, 因此我们可以不用添加 pkg前缀
//  如果不是同一个pkg 就需要添加 pkg名称前缀, 比如hello.ErrorStatus
import "pb/any.proto";

package hello;
option go_package="gitee.com/infraboard/go-course/day21/pb";

message ErrorStatusExt {
    ErrorStatus error_status = 1;
}

# 当前目录: day21
protoc -I=. --go_out=./pb --go_opt=module="gitee.com/infraboard/go-course/day21/pb" pb/import.proto