proto生成的代码中，有一个byte数组，这个数组是干嘛的呢？
代码语言：javascript复制var file_reflection_grpc_reflection_v1alpha_reflection_proto_rawDesc = []byte{
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}相信很多人都有疑问。我们使用grpc reflection的时候，用到的proto元信息来自哪里呢，会不会和这个奇怪的数组有关？下面我们从源码来一探究竟。
反射概念最早出现于人工智能领域，20 世纪 70 年代末被引入到程序语言设计中。1982 年 MIT 的 Smith, Brian Cantwell 在他的博士论文中最早提出了程序反射的概念：
既然我们可以构造“有关某个外部世界表示”的计算过程, 并通过它来对那个外部世界进行推理; 那么我们也可以构造能够对自身表示和计算进行推理的计算过程 ,它包含负责管理有关自身的操作和结构表示的内部过程。
如何使用grpc reflection呢，很简单，直接注册就行了：
代码语言：javascript复制reflection.Register(grpcServer)Register函数定义在google.golang.org/grpc@v1.41.0/reflection/serverreflection.go
代码语言：javascript复制func Register(s GRPCServer) {
rpb.RegisterServerReflectionServer(s, &serverReflectionServer{
s: s,
})
}其中serverReflectionServer定义如下：
代码语言：javascript复制type serverReflectionServer struct {
rpb.UnimplementedServerReflectionServer
s GRPCServer
initSymbols sync.Once
serviceNames []string
symbols map[string]*dpb.FileDescriptorProto // map of fully-qualified names to files
}它内嵌了GRPCServer
代码语言：javascript复制type GRPCServer interface {
grpc.ServiceRegistrar
GetServiceInfo() map[string]grpc.ServiceInfo
}其中ServiceRegistrar 是一个接口，定义如何把服务的元信息注入的方法：
代码语言：javascript复制func RegisterServerReflectionServer(s grpc.ServiceRegistrar, srv ServerReflectionServer) {
s.RegisterService(&ServerReflection_ServiceDesc, srv)
}type ServiceRegistrar interface {
// RegisterService registers a service and its implementation to the
// concrete type implementing this interface. It may not be called
// once the server has started serving.
// desc describes the service and its methods and handlers. impl is the
// service implementation which is passed to the method handlers.
RegisterService(desc *ServiceDesc, impl interface{})
}grpc reflection 本质上依然是个grpc服务，它也有proto：reflection/grpc_reflection_v1alpha/reflection.proto定义如下：
代码语言：javascript复制syntax = "proto3";
option go_package = "google.golang.org/grpc/reflection/grpc_reflection_v1alpha";
package grpc.reflection.v1alpha;
service ServerReflection {
// The reflection service is structured as a bidirectional stream, ensuring
// all related requests go to a single server.
rpc ServerReflectionInfo(stream ServerReflectionRequest)
returns (stream ServerReflectionResponse);
}
// The message sent by the client when calling ServerReflectionInfo method.
message ServerReflectionRequest {
string host = 1;
// To use reflection service, the client should set one of the following
// fields in message_request. The server distinguishes requests by their
// defined field and then handles them using corresponding methods.
oneof message_request {
// Find a proto file by the file name.
string file_by_filename = 3;
// Find the proto file that declares the given fully-qualified symbol name.
// This field should be a fully-qualified symbol name
// (e.g. <package>.<service>[.<method>] or <package>.<type>).
string file_containing_symbol = 4;
// Find the proto file which defines an extension extending the given
// message type with the given field number.
ExtensionRequest file_containing_extension = 5;
// Finds the tag numbers used by all known extensions of extendee_type, and
// appends them to ExtensionNumberResponse in an undefined order.
// Its corresponding method is best-effort: it's not guaranteed that the
// reflection service will implement this method, and it's not guaranteed
// that this method will provide all extensions. Returns
// StatusCode::UNIMPLEMENTED if it's not implemented.
// This field should be a fully-qualified type name. The format is
// <package>.<type>
string all_extension_numbers_of_type = 6;
// List the full names of registered services. The content will not be
// checked.
string list_services = 7;
}
}
// The type name and extension number sent by the client when requesting
// file_containing_extension.
message ExtensionRequest {
// Fully-qualified type name. The format should be <package>.<type>
string containing_type = 1;
int32 extension_number = 2;
}
// The message sent by the server to answer ServerReflectionInfo method.
message ServerReflectionResponse {
string valid_host = 1;
ServerReflectionRequest original_request = 2;
// The server sets one of the following fields according to the
// message_request in the request.
oneof message_response {
// This message is used to answer file_by_filename, file_containing_symbol,
// file_containing_extension requests with transitive dependencies.
// As the repeated label is not allowed in oneof fields, we use a
// FileDescriptorResponse message to encapsulate the repeated fields.
// The reflection service is allowed to avoid sending FileDescriptorProtos
// that were previously sent in response to earlier requests in the stream.
FileDescriptorResponse file_descriptor_response = 4;
// This message is used to answer all_extension_numbers_of_type requests.
ExtensionNumberResponse all_extension_numbers_response = 5;
// This message is used to answer list_services requests.
ListServiceResponse list_services_response = 6;
// This message is used when an error occurs.
ErrorResponse error_response = 7;
}
}
// Serialized FileDescriptorProto messages sent by the server answering
// a file_by_filename, file_containing_symbol, or file_containing_extension
// request.
message FileDescriptorResponse {
// Serialized FileDescriptorProto messages. We avoid taking a dependency on
// descriptor.proto, which uses proto2 only features, by making them opaque
// bytes instead.
repeated bytes file_descriptor_proto = 1;
}
// A list of extension numbers sent by the server answering
// all_extension_numbers_of_type request.
message ExtensionNumberResponse {
// Full name of the base type, including the package name. The format
// is <package>.<type>
string base_type_name = 1;
repeated int32 extension_number = 2;
}
// A list of ServiceResponse sent by the server answering list_services request.
message ListServiceResponse {
// The information of each service may be expanded in the future, so we use
// ServiceResponse message to encapsulate it.
repeated ServiceResponse service = 1;
}
// The information of a single service used by ListServiceResponse to answer
// list_services request.
message ServiceResponse {
// Full name of a registered service, including its package name. The format
// is <package>.<service>
string name = 1;
}
// The error code and error message sent by the server when an error occurs.
message ErrorResponse {
// This field uses the error codes defined in grpc::StatusCode.
int32 error_code = 1;
string error_message = 2;
}它定义了一个ServerReflectionInfo一个接口。看下它生成的go文件
google.golang.org/grpc@v1.44.0/reflection/grpc_reflection_v1alpha/reflection_grpc.pb.go
代码语言：javascript复制func RegisterServerReflectionServer(s grpc.ServiceRegistrar, srv ServerReflectionServer) {
s.RegisterService(&ServerReflection_ServiceDesc, srv)
}注入服务引用了ServerReflection_ServiceDesc这个变量
代码语言：javascript复制// ServerReflection_ServiceDesc is the grpc.ServiceDesc for ServerReflection service.
// It's only intended for direct use with grpc.RegisterService,
// and not to be introspected or modified (even as a copy)
var ServerReflection_ServiceDesc = grpc.ServiceDesc{
ServiceName: "grpc.reflection.v1alpha.ServerReflection",
HandlerType: (*ServerReflectionServer)(nil),
Methods: []grpc.MethodDesc{},
Streams: []grpc.StreamDesc{
{
StreamName: "ServerReflectionInfo",
Handler: _ServerReflection_ServerReflectionInfo_Handler,
ServerStreams: true,
ClientStreams: true,
},
},
Metadata: "reflection/grpc_reflection_v1alpha/reflection.proto",
}仔细看看，它包含了服务名，方法名（StreamName），对应的处理方法（Handler），这是每个proto service都会生成的描述service 的元信息
代码语言：javascript复制var xxxx_ServiceDesc grpc.ServiceDesc{}func _ServerReflection_ServerReflectionInfo_Handler(srv interface{}, stream grpc.ServerStream) error {
return srv.(ServerReflectionServer).ServerReflectionInfo(&serverReflectionServerReflectionInfoServer{stream})
}handler仅仅通过类型推断，调用了对应的方法，也是每个proto都会生成的代码，格式如下：xxx_xxx_Handler，当然也会生成一个默认实现了我们定义的接口的struct
代码语言：javascript复制// UnimplementedServerReflectionServer should be embedded to have forward compatible implementations.
type UnimplementedServerReflectionServer struct {
}
func (UnimplementedServerReflectionServer) ServerReflectionInfo(ServerReflection_ServerReflectionInfoServer) error {
return status.Errorf(codes.Unimplemented, "method ServerReflectionInfo not implemented")
}生成的客户端代码中会调用上述方法：
代码语言：javascript复制func (c *serverReflectionClient) ServerReflectionInfo(ctx context.Context, opts ...grpc.CallOption) (ServerReflection_ServerReflectionInfoClient, error) {
stream, err := c.cc.NewStream(ctx, &ServerReflection_ServiceDesc.Streams[0], "/grpc.reflection.v1alpha.ServerReflection/ServerReflectionInfo", opts...)
if err != nil {
return nil, err
}
x := &serverReflectionServerReflectionInfoClient{stream}
return x, nil
}reflect server的真实实现代码位于
google.golang.org/grpc@v1.44.0/reflection/serverreflection.go定义了一个结构体serverReflectionServer实现了前面定义的proto的接口
代码语言：javascript复制type serverReflectionServer struct {
rpb.UnimplementedServerReflectionServer
s GRPCServer
initSymbols sync.Once
serviceNames []string
symbols map[string]*dpb.FileDescriptorProto // map of fully-qualified names to files
}具体如下：
代码语言：javascript复制func (s *serverReflectionServer) ServerReflectionInfo(stream rpb.ServerReflection_ServerReflectionInfoServer) error {
switch req := in.MessageRequest.(type) {
case *rpb.ServerReflectionRequest_FileByFilename:
case *rpb.ServerReflectionRequest_FileContainingSymbol:
b, err := s.fileDescEncodingContainingSymbol(req.FileContainingSymbol, sentFileDescriptors)
case *rpb.ServerReflectionRequest_FileContainingExtension:
case *rpb.ServerReflectionRequest_AllExtensionNumbersOfType:
case *rpb.ServerReflectionRequest_ListServices:
svcNames, _ := s.getSymbols()
}介绍完服务端核心代码后，我们从客户端开始详细介绍一个grpc reflect请求的详细过程。我们知道grpcurl 是基于grpc reflection实现的，它本质上是对grpc reflection 的client的一个包装。那么我们就从grpcurl 的源码入手开始分析：cmd/grpcurl.go 在main方法里面，首先初始化了一个grpc连接，用这个链接初始化了refletionClient，然后根据我们传入的命令后参数选项，分别调用了不同的方法，比如list 命令调用了grpcurl.ListMethods(descSource, symbol) list调用了 grpcurl.GetDescriptorText(dsc, descSource)，decription调用了descSource.FindSymbol(s)
代码语言：javascript复制dial := func() *grpc.ClientConn {
cc, err := grpcurl.BlockingDial(ctx, network, target, creds, opts...)
}
refClient = grpcreflect.NewClient(refCtx, reflectpb.NewServerReflectionClient(cc))
reflSource := grpcurl.DescriptorSourceFromServer(ctx, refClient)
svcs, err := grpcurl.ListServices(descSource)
methods, err := grpcurl.ListMethods(descSource, symbol)
svcs, err := descSource.ListServices()
txt, err := grpcurl.GetDescriptorText(dsc, descSource)
dsc, err := descSource.FindSymbol(s)
fqn := dsc.GetFullyQualifiedName()
var elementType string
switch d := dsc.(type) {
case *desc.MessageDescriptor:
elementType = "a message"
parent, ok := d.GetParent().(*desc.MessageDescriptor)descriptionSource定义在desc_source.go，核心有三个方法
代码语言：javascript复制func DescriptorSourceFromServer(_ context.Context, refClient *grpcreflect.Client) DescriptorSource {
return serverSource{client: refClient}
}type DescriptorSource interface {
// ListServices returns a list of fully-qualified service names. It will be all services in a set of
// descriptor files or the set of all services exposed by a gRPC server.
ListServices() ([]string, error)
// FindSymbol returns a descriptor for the given fully-qualified symbol name.
FindSymbol(fullyQualifiedName string) (desc.Descriptor, error)
// AllExtensionsForType returns all known extension fields that extend the given message type name.
AllExtensionsForType(typeName string) ([]*desc.FieldDescriptor, error)
}serverSource是上述接口的一个实现：
代码语言：javascript复制type serverSource struct {
client *grpcreflect.Client
}
func (ss serverSource) ListServices() ([]string, error) {
svcs, err := ss.client.ListServices()
return svcs, reflectionSupport(err)
}
func (ss serverSource) FindSymbol(fullyQualifiedName string) (desc.Descriptor, error){
file, err := ss.client.FileContainingSymbol(fullyQualifiedName)
d := file.FindSymbol(fullyQualifiedName)
}它其实仅仅对grpc reflect 的client的一个封装，代码位于：
github.com/jhump/protoreflect@v1.10.3/grpcreflect/client.go
代码语言：javascript复制func (cr *Client) ListServices() ([]string, error) {
req := &rpb.ServerReflectionRequest{
MessageRequest: &rpb.ServerReflectionRequest_ListServices{
// proto doesn't indicate any purpose for this value and server impl
// doesn't actually use it...
ListServices: "*",
},
}
resp, err := cr.send(req)
if err != nil {
return nil, err
}
listResp := resp.GetListServicesResponse()
if listResp == nil {
return nil, &ProtocolError{reflect.TypeOf(listResp).Elem()}
}
serviceNames := make([]string, len(listResp.Service))
for i, s := range listResp.Service {
serviceNames[i] = s.Name
}
return serviceNames, nil
}func (cr *Client) FileContainingSymbol(symbol string) (*desc.FileDescriptor, error) {
req := &rpb.ServerReflectionRequest{
MessageRequest: &rpb.ServerReflectionRequest_FileContainingSymbol{
FileContainingSymbol: symbol,
},
}
}我们回到server端，可以看到list，对应的是
代码语言：javascript复制 case *rpb.ServerReflectionRequest_ListServices:
svcNames, _ := s.getSymbols()它调用了
代码语言：javascript复制func (s *serverReflectionServer) getSymbols() (svcNames []string, symbolIndex map[string]*dpb.FileDescriptorProto)
serviceInfo := s.s.GetServiceInfo()
for svc, info := range serviceInfo {
s.serviceNames = append(s.serviceNames, svc)
fdenc, ok := parseMetadata(info.Metadata)
fd, err := decodeFileDesc(fdenc)
s.processFile(fd, processed)其中的s是接口s GRPCServer它的实现位于
google.golang.org/grpc@v1.44.0/server.go
代码语言：javascript复制// ServiceRegistrar wraps a single method that supports service registration. It
// enables users to pass concrete types other than grpc.Server to the service
// registration methods exported by the IDL generated code.
type ServiceRegistrar interface {
// RegisterService registers a service and its implementation to the
// concrete type implementing this interface. It may not be called
// once the server has started serving.
// desc describes the service and its methods and handlers. impl is the
// service implementation which is passed to the method handlers.
RegisterService(desc *ServiceDesc, impl interface{})
}上述接口对应的实现类如下
代码语言：javascript复制type Server struct {
opts serverOptions
mu sync.Mutex // guards following
lis map[net.Listener]bool
// conns contains all active server transports. It is a map keyed on a
// listener address with the value being the set of active transports
// belonging to that listener.
conns map[string]map[transport.ServerTransport]bool
serve bool
drain bool
cv *sync.Cond // signaled when connections close for GracefulStop
services map[string]*serviceInfo // service name -> service info
events trace.EventLog
quit *grpcsync.Event
done *grpcsync.Event
channelzRemoveOnce sync.Once
serveWG sync.WaitGroup // counts active Serve goroutines for GracefulStop
channelzID int64 // channelz unique identification number
czData *channelzData
serverWorkerChannels []chan *serverWorkerData
}// GetServiceInfo returns a map from service names to ServiceInfo.
// Service names include the package names, in the form of <package>.<service>.
func (s *Server) GetServiceInfo() map[string]ServiceInfo {
for n, srv := range s.services {
}func NewServer(opt ...ServerOption) *Server {
s := &Server{
services: make(map[string]*serviceInfo),
}
}返回的ServiceInfo定义如下：
代码语言：javascript复制// ServiceInfo contains unary RPC method info, streaming RPC method info and metadata for a service.
type ServiceInfo struct {
Methods []MethodInfo
// Metadata is the metadata specified in ServiceDesc when registering service.
Metadata interface{}
}它提供了注册方法，把service信息注册到map里面
代码语言：javascript复制func (s *Server) RegisterService(sd *ServiceDesc, ss interface{}){
s.register(sd, ss)
}func (s *Server) register(sd *ServiceDesc, ss interface{}) {
if _, ok := s.services[sd.ServiceName]; ok {
logger.Fatalf("grpc: Server.RegisterService found duplicate service registration for %q", sd.ServiceName)
}
info := &serviceInfo{
serviceImpl: ss,
methods: make(map[string]*MethodDesc),
streams: make(map[string]*StreamDesc),
mdata: sd.Metadata,
}
s.services[sd.ServiceName] = info
}其中servicedesc如下：
代码语言：javascript复制// ServiceDesc represents an RPC service's specification.
type ServiceDesc struct {
ServiceName string
// The pointer to the service interface. Used to check whether the user
// provided implementation satisfies the interface requirements.
HandlerType interface{}
Methods []MethodDesc
Streams []StreamDesc
Metadata interface{}
}主要作用就是把我们前面提到的ServerReflection_ServiceDesc对象注入到ServiceDesc供后面使用。
接着我们看下desc它对应的代码是
代码语言：javascript复制case *rpb.ServerReflectionRequest_FileContainingSymbol:
b, err := s.fileDescEncodingContainingSymbol(req.FileContainingSymbol, sentFileDescriptors)func (s *serverReflectionServer) fileDescEncodingContainingSymbol(name string, sentFileDescriptors map[string]bool) ([][]byte, error) {
fd, err = s.fileDescForType(st)
}func (s *serverReflectionServer) fileDescForType(st reflect.Type) (*dpb.FileDescriptorProto, error) {
m, ok := reflect.Zero(reflect.PtrTo(st)).Interface().(protoMessage)
enc, _ := m.Descriptor()
return decodeFileDesc(enc)
}func decodeFileDesc(enc []byte) (*dpb.FileDescriptorProto, error) {
raw, err := decompress(enc)
fd := new(dpb.FileDescriptorProto)
if err := proto.Unmarshal(raw, fd); err != nil {
}func decompress(b []byte) ([]byte, error) {
r, err := gzip.NewReader(bytes.NewReader(b))
}它先从m.Descriptor()拿到数据，然后decompress，Descriptor是获取原始数据的一个接口，它一般会被压缩后存储：
代码语言：javascript复制// protoMessage is used for type assertion on proto messages.
// Generated proto message implements function Descriptor(), but Descriptor()
// is not part of interface proto.Message. This interface is needed to
// call Descriptor().
type protoMessage interface {
Descriptor() ([]byte, []int)
}以为ServerReflectionRequest例
代码语言：javascript复制func (*ServerReflectionRequest) Descriptor() ([]byte, []int) {
return file_reflection_grpc_reflection_v1alpha_reflection_proto_rawDescGZIP(), []int{0}
}func file_reflection_grpc_reflection_v1alpha_reflection_proto_rawDescGZIP() []byte {
file_reflection_grpc_reflection_v1alpha_reflection_proto_rawDescData = protoimpl.X.CompressGZIP(file_reflection_grpc_reflection_v1alpha_reflection_proto_rawDescData)
} file_reflection_grpc_reflection_v1alpha_reflection_proto_rawDescData = file_reflection_grpc_reflection_v1alpha_reflection_proto_rawDesc它里面最终存储的数据是gzip后的，我们开头提到的奇怪的byte数组。
代码语言：javascript复制var file_reflection_grpc_reflection_v1alpha_reflection_proto_rawDesc = []byte{
0x0a, 0x33, 0x72, 0x65, 0x66, 0x6c, 0x65, 0x63, 0x74, 0x69, 0x6f, 0x6e, 0x2f, 0x67, 0x72, 0x70,
}解压后它会被unmarshal到FileDescriptorProto里面
代码语言：javascript复制 fd := new(dpb.FileDescriptorProto)
if err := proto.Unmarshal(raw, fd); err != nil {它的定义位于
github.com/golang/protobuf@v1.5.2/protoc-gen-go/descriptor/descriptor.pb.go
代码语言：javascript复制type FileDescriptorProto = descriptorpb.FileDescriptorProto它其实就是grpc reflect的核心，它里面定义了proto文件的完整信息，被序列化后就是我们开头开到的奇怪的byte数组。我们简单验证下：
代码语言：javascript复制package main
import (
"fmt"
dpb "github.com/golang/protobuf/protoc-gen-go/descriptor"
"google.golang.org/protobuf/proto"
)
func main() {
fd := new(dpb.FileDescriptorProto)
if err := proto.Unmarshal(file_reflection_grpc_reflection_v1alpha_reflection_proto_rawDesc, fd); err != nil {
fmt.Println(err)
return
}
fmt.Println(fd)
}
var file_reflection_grpc_reflection_v1alpha_reflection_proto_rawDesc = []byte{
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}真的和我们预期的一样，输出如下：
代码语言：javascript复制name:"reflection/grpc_reflection_v1alpha/reflection.proto" package:"grpc.reflection.v1alpha" message_type:{name:"ServerReflectionRequest" field:{name:"host" number:1 label:LABEL_OPTIONAL type:TYPE_STRING json_name:"host"} field:{name:"file_by_filename" number:3 label:LABEL_OPTIONAL type:TYPE_STRING oneof_index:0 json_name:"fileByFilename"} field:{name:"file_containing_symbol" number:4 label:LABEL_OPTIONAL type:TYPE_STRING oneof_index:0 json_name:"fileContainingSymbol"} field:{name:"file_containing_extension" number:5 label:LABEL_OPTIONAL type:TYPE_MESSAGE type_name:".grpc.reflection.v1alpha.ExtensionRequest" oneof_index:0 json_name:"fileContainingExtension"} field:{name:"all_extension_numbers_of_type" number:6 label:LABEL_OPTIONAL type:TYPE_STRING oneof_index:0 json_name:"allExtensionNumbersOfType"} field:{name:"list_services" number:7 label:LABEL_OPTIONAL type:TYPE_STRING oneof_index:0 json_name:"listServices"} oneof_decl:{name:"message_request"}} message_type:{name:"ExtensionRequest" field:{name:"containing_type" number:1 label:LABEL_OPTIONAL type:TYPE_STRING json_name:"containingType"} field:{name:"extension_number" number:2 label:LABEL_OPTIONAL type:TYPE_INT32 json_name:"extensionNumber"}} message_type:{name:"ServerReflectionResponse" field:{name:"valid_host" number:1 label:LABEL_OPTIONAL type:TYPE_STRING json_name:"validHost"} field:{name:"original_request" number:2 label:LABEL_OPTIONAL type:TYPE_MESSAGE type_name:".grpc.reflection.v1alpha.ServerReflectionRequest" json_name:"originalRequest"} field:{name:"file_descriptor_response" number:4 label:LABEL_OPTIONAL type:TYPE_MESSAGE type_name:".grpc.reflection.v1alpha.FileDescriptorResponse" oneof_index:0 json_name:"fileDescriptorResponse"} field:{name:"all_extension_numbers_response" number:5 label:LABEL_OPTIONAL type:TYPE_MESSAGE type_name:".grpc.reflection.v1alpha.ExtensionNumberResponse" oneof_index:0 json_name:"allExtensionNumbersResponse"} field:{name:"list_services_response" number:6 label:LABEL_OPTIONAL type:TYPE_MESSAGE type_name:".grpc.reflection.v1alpha.ListServiceResponse" oneof_index:0 json_name:"listServicesResponse"} field:{name:"error_response" number:7 label:LABEL_OPTIONAL type:TYPE_MESSAGE type_name:".grpc.reflection.v1alpha.ErrorResponse" oneof_index:0 json_name:"errorResponse"} oneof_decl:{name:"message_response"}} message_type:{name:"FileDescriptorResponse" field:{name:"file_descriptor_proto" number:1 label:LABEL_REPEATED type:TYPE_BYTES json_name:"fileDescriptorProto"}} message_type:{name:"ExtensionNumberResponse" field:{name:"base_type_name" number:1 label:LABEL_OPTIONAL type:TYPE_STRING json_name:"baseTypeName"} field:{name:"extension_number" number:2 label:LABEL_REPEATED type:TYPE_INT32 json_name:"extensionNumber"}} message_type:{name:"ListServiceResponse" field:{name:"service" number:1 label:LABEL_REPEATED type:TYPE_MESSAGE type_name:".grpc.reflection.v1alpha.ServiceResponse" json_name:"service"}} message_type:{name:"ServiceResponse" field:{name:"name" number:1 label:LABEL_OPTIONAL type:TYPE_STRING json_name:"name"}} message_type:{name:"ErrorResponse" field:{name:"error_code" number:1 label:LABEL_OPTIONAL type:TYPE_INT32 json_name:"errorCode"} field:{name:"error_message" number:2 label:LABEL_OPTIONAL type:TYPE_STRING json_name:"errorMessage"}} service:{name:"ServerReflection" method:{name:"ServerReflectionInfo" input_type:".grpc.reflection.v1alpha.ServerReflectionRequest" output_type:".grpc.reflection.v1alpha.ServerReflectionResponse" client_streaming:true server_streaming:true}} options:{go_package:"google.golang.org/grpc/reflection/grpc_reflection_v1alpha"} syntax:"proto3"
