reflection update

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

options.go

@@ -36,7 +36,6 @@ func Options(opts ...grpc.ServerOption) server.Option {
 	return server.SetOption(grpcOptions{}, opts)
 }
 
-//
 // MaxMsgSize set the maximum message in bytes the server can receive and
 // send. Default maximum message size is 4 MB.
 func MaxMsgSize(s int) server.Option {
@@ -44,8 +43,8 @@ func MaxMsgSize(s int) server.Option {
 }
 
 // Reflection enables reflection support in grpc server
-func Reflection(b bool) server.Option {
+func Reflection(r Reflector) server.Option {
-	return server.SetOption(reflectionKey{}, b)
+	return server.SetOption(reflectionKey{}, r)
 }
 
 // UnknownServiceHandler enables support for all services

reflection.go

@@ -1,488 +1,23 @@
-// +build ignore
-
-/*
- *
- * Copyright 2016 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-/*
-Package reflection implements server reflection service.
-
-The service implemented is defined in:
-https://github.com/grpc/grpc/blob/master/src/proto/grpc/reflection/v1alpha/reflection.proto.
-
-To register server reflection on a gRPC server:
-	import "google.golang.org/grpc/reflection"
-
-	s := grpc.NewServer()
-	pb.RegisterYourOwnServer(s, &server{})
-
-	// Register reflection service on gRPC server.
-	reflection.Register(s)
-
-	s.Serve(lis)
-
-*/
 package grpc
 
 import (
-	"bytes"
+	"google.golang.org/grpc/reflection"
-	"compress/gzip"
+	"google.golang.org/protobuf/reflect/protodesc"
-	"fmt"
-	"io"
-	"io/ioutil"
-	"reflect"
-	"sort"
-	"sync"
-
-	"github.com/golang/protobuf/proto"
-	dpb "github.com/golang/protobuf/protoc-gen-go/descriptor"
-	"google.golang.org/grpc"
-	"google.golang.org/grpc/codes"
-	rpb "google.golang.org/grpc/reflection/grpc_reflection_v1alpha"
-	"google.golang.org/grpc/status"
 )
 
-type serverReflectionServer struct {
+type Reflector interface {
-	rpb.UnimplementedServerReflectionServer
+	protodesc.Resolver
-	s *grpc.Server
+	reflection.ServiceInfoProvider
-
+	reflection.ExtensionResolver
-	initSymbols  sync.Once
-	serviceNames []string
-	symbols      map[string]*dpb.FileDescriptorProto // map of fully-qualified names to files
 }
 
-// Register registers the server reflection service on the given gRPC server.
+const (
-func Register(s *grpc.Server) {
+	// ReflectV1ServiceName is the fully-qualified name of the v1 version of the reflection service.
-	rpb.RegisterServerReflectionServer(s, &serverReflectionServer{
+	ReflectV1ServiceName = "grpc.reflection.v1.ServerReflection"
-		s: s,
+	// ReflectV1AlphaServiceName is the fully-qualified name of the v1alpha version of the reflection service.
-	})
+	ReflectV1AlphaServiceName = "grpc.reflection.v1alpha.ServerReflection"
-}
 
-// protoMessage is used for type assertion on proto messages.
+	ReflectServiceURLPathV1      = "/" + ReflectV1ServiceName + "/"
-// Generated proto message implements function Descriptor(), but Descriptor()
+	ReflectServiceURLPathV1Alpha = "/" + ReflectV1AlphaServiceName + "/"
-// is not part of interface proto.Message. This interface is needed to
+	ReflectMethodName            = "ServerReflectionInfo"
-// call Descriptor().
+)
-type protoMessage interface {
-	Descriptor() ([]byte, []int)
-}
-
-func (s *serverReflectionServer) getSymbols() (svcNames []string, symbolIndex map[string]*dpb.FileDescriptorProto) {
-	s.initSymbols.Do(func() {
-		serviceInfo := s.s.GetServiceInfo()
-
-		s.symbols = map[string]*dpb.FileDescriptorProto{}
-		s.serviceNames = make([]string, 0, len(serviceInfo))
-		processed := map[string]struct{}{}
-		for svc, info := range serviceInfo {
-			s.serviceNames = append(s.serviceNames, svc)
-			fdenc, ok := parseMetadata(info.Metadata)
-			if !ok {
-				continue
-			}
-			fd, err := decodeFileDesc(fdenc)
-			if err != nil {
-				continue
-			}
-			s.processFile(fd, processed)
-		}
-		sort.Strings(s.serviceNames)
-	})
-
-	return s.serviceNames, s.symbols
-}
-
-func (s *serverReflectionServer) processFile(fd *dpb.FileDescriptorProto, processed map[string]struct{}) {
-	filename := fd.GetName()
-	if _, ok := processed[filename]; ok {
-		return
-	}
-	processed[filename] = struct{}{}
-
-	prefix := fd.GetPackage()
-
-	for _, msg := range fd.MessageType {
-		s.processMessage(fd, prefix, msg)
-	}
-	for _, en := range fd.EnumType {
-		s.processEnum(fd, prefix, en)
-	}
-	for _, ext := range fd.Extension {
-		s.processField(fd, prefix, ext)
-	}
-	for _, svc := range fd.Service {
-		svcName := fqn(prefix, svc.GetName())
-		s.symbols[svcName] = fd
-		for _, meth := range svc.Method {
-			name := fqn(svcName, meth.GetName())
-			s.symbols[name] = fd
-		}
-	}
-
-	for _, dep := range fd.Dependency {
-		fdenc := proto.FileDescriptor(dep)
-		fdDep, err := decodeFileDesc(fdenc)
-		if err != nil {
-			continue
-		}
-		s.processFile(fdDep, processed)
-	}
-}
-
-func (s *serverReflectionServer) processMessage(fd *dpb.FileDescriptorProto, prefix string, msg *dpb.DescriptorProto) {
-	msgName := fqn(prefix, msg.GetName())
-	s.symbols[msgName] = fd
-
-	for _, nested := range msg.NestedType {
-		s.processMessage(fd, msgName, nested)
-	}
-	for _, en := range msg.EnumType {
-		s.processEnum(fd, msgName, en)
-	}
-	for _, ext := range msg.Extension {
-		s.processField(fd, msgName, ext)
-	}
-	for _, fld := range msg.Field {
-		s.processField(fd, msgName, fld)
-	}
-	for _, oneof := range msg.OneofDecl {
-		oneofName := fqn(msgName, oneof.GetName())
-		s.symbols[oneofName] = fd
-	}
-}
-
-func (s *serverReflectionServer) processEnum(fd *dpb.FileDescriptorProto, prefix string, en *dpb.EnumDescriptorProto) {
-	enName := fqn(prefix, en.GetName())
-	s.symbols[enName] = fd
-
-	for _, val := range en.Value {
-		valName := fqn(enName, val.GetName())
-		s.symbols[valName] = fd
-	}
-}
-
-func (s *serverReflectionServer) processField(fd *dpb.FileDescriptorProto, prefix string, fld *dpb.FieldDescriptorProto) {
-	fldName := fqn(prefix, fld.GetName())
-	s.symbols[fldName] = fd
-}
-
-func fqn(prefix, name string) string {
-	if prefix == "" {
-		return name
-	}
-	return prefix + "." + name
-}
-
-// fileDescForType gets the file descriptor for the given type.
-// The given type should be a proto message.
-func (s *serverReflectionServer) fileDescForType(st reflect.Type) (*dpb.FileDescriptorProto, error) {
-	m, ok := reflect.Zero(reflect.PtrTo(st)).Interface().(protoMessage)
-	if !ok {
-		return nil, fmt.Errorf("failed to create message from type: %v", st)
-	}
-	enc, _ := m.Descriptor()
-
-	return decodeFileDesc(enc)
-}
-
-// decodeFileDesc does decompression and unmarshalling on the given
-// file descriptor byte slice.
-func decodeFileDesc(enc []byte) (*dpb.FileDescriptorProto, error) {
-	raw, err := decompress(enc)
-	if err != nil {
-		return nil, fmt.Errorf("failed to decompress enc: %v", err)
-	}
-
-	fd := new(dpb.FileDescriptorProto)
-	if err := proto.Unmarshal(raw, fd); err != nil {
-		return nil, fmt.Errorf("bad descriptor: %v", err)
-	}
-	return fd, nil
-}
-
-// decompress does gzip decompression.
-func decompress(b []byte) ([]byte, error) {
-	r, err := gzip.NewReader(bytes.NewReader(b))
-	if err != nil {
-		return nil, fmt.Errorf("bad gzipped descriptor: %v", err)
-	}
-	out, err := ioutil.ReadAll(r)
-	if err != nil {
-		return nil, fmt.Errorf("bad gzipped descriptor: %v", err)
-	}
-	return out, nil
-}
-
-func typeForName(name string) (reflect.Type, error) {
-	pt := proto.MessageType(name)
-	if pt == nil {
-		return nil, fmt.Errorf("unknown type: %q", name)
-	}
-	st := pt.Elem()
-
-	return st, nil
-}
-
-func fileDescContainingExtension(st reflect.Type, ext int32) (*dpb.FileDescriptorProto, error) {
-	m, ok := reflect.Zero(reflect.PtrTo(st)).Interface().(proto.Message)
-	if !ok {
-		return nil, fmt.Errorf("failed to create message from type: %v", st)
-	}
-
-	var extDesc *proto.ExtensionDesc
-	for id, desc := range proto.RegisteredExtensions(m) {
-		if id == ext {
-			extDesc = desc
-			break
-		}
-	}
-
-	if extDesc == nil {
-		return nil, fmt.Errorf("failed to find registered extension for extension number %v", ext)
-	}
-
-	return decodeFileDesc(proto.FileDescriptor(extDesc.Filename))
-}
-
-func (s *serverReflectionServer) allExtensionNumbersForType(st reflect.Type) ([]int32, error) {
-	m, ok := reflect.Zero(reflect.PtrTo(st)).Interface().(proto.Message)
-	if !ok {
-		return nil, fmt.Errorf("failed to create message from type: %v", st)
-	}
-
-	exts := proto.RegisteredExtensions(m)
-	out := make([]int32, 0, len(exts))
-	for id := range exts {
-		out = append(out, id)
-	}
-	return out, nil
-}
-
-// fileDescWithDependencies returns a slice of serialized fileDescriptors in
-// wire format ([]byte). The fileDescriptors will include fd and all the
-// transitive dependencies of fd with names not in sentFileDescriptors.
-func fileDescWithDependencies(fd *dpb.FileDescriptorProto, sentFileDescriptors map[string]bool) ([][]byte, error) {
-	r := [][]byte{}
-	queue := []*dpb.FileDescriptorProto{fd}
-	for len(queue) > 0 {
-		currentfd := queue[0]
-		queue = queue[1:]
-		if sent := sentFileDescriptors[currentfd.GetName()]; len(r) == 0 || !sent {
-			sentFileDescriptors[currentfd.GetName()] = true
-			currentfdEncoded, err := proto.Marshal(currentfd)
-			if err != nil {
-				return nil, err
-			}
-			r = append(r, currentfdEncoded)
-		}
-		for _, dep := range currentfd.Dependency {
-			fdenc := proto.FileDescriptor(dep)
-			fdDep, err := decodeFileDesc(fdenc)
-			if err != nil {
-				continue
-			}
-			queue = append(queue, fdDep)
-		}
-	}
-	return r, nil
-}
-
-// fileDescEncodingByFilename finds the file descriptor for given filename,
-// finds all of its previously unsent transitive dependencies, does marshalling
-// on them, and returns the marshalled result.
-func (s *serverReflectionServer) fileDescEncodingByFilename(name string, sentFileDescriptors map[string]bool) ([][]byte, error) {
-	enc := proto.FileDescriptor(name)
-	if enc == nil {
-		return nil, fmt.Errorf("unknown file: %v", name)
-	}
-	fd, err := decodeFileDesc(enc)
-	if err != nil {
-		return nil, err
-	}
-	return fileDescWithDependencies(fd, sentFileDescriptors)
-}
-
-// parseMetadata finds the file descriptor bytes specified meta.
-// For SupportPackageIsVersion4, m is the name of the proto file, we
-// call proto.FileDescriptor to get the byte slice.
-// For SupportPackageIsVersion3, m is a byte slice itself.
-func parseMetadata(meta interface{}) ([]byte, bool) {
-	// Check if meta is the file name.
-	if fileNameForMeta, ok := meta.(string); ok {
-		return proto.FileDescriptor(fileNameForMeta), true
-	}
-
-	// Check if meta is the byte slice.
-	if enc, ok := meta.([]byte); ok {
-		return enc, true
-	}
-
-	return nil, false
-}
-
-// fileDescEncodingContainingSymbol finds the file descriptor containing the
-// given symbol, finds all of its previously unsent transitive dependencies,
-// does marshalling on them, and returns the marshalled result. The given symbol
-// can be a type, a service or a method.
-func (s *serverReflectionServer) fileDescEncodingContainingSymbol(name string, sentFileDescriptors map[string]bool) ([][]byte, error) {
-	_, symbols := s.getSymbols()
-	fd := symbols[name]
-	if fd == nil {
-		// Check if it's a type name that was not present in the
-		// transitive dependencies of the registered services.
-		if st, err := typeForName(name); err == nil {
-			fd, err = s.fileDescForType(st)
-			if err != nil {
-				return nil, err
-			}
-		}
-	}
-
-	if fd == nil {
-		return nil, fmt.Errorf("unknown symbol: %v", name)
-	}
-
-	return fileDescWithDependencies(fd, sentFileDescriptors)
-}
-
-// fileDescEncodingContainingExtension finds the file descriptor containing
-// given extension, finds all of its previously unsent transitive dependencies,
-// does marshalling on them, and returns the marshalled result.
-func (s *serverReflectionServer) fileDescEncodingContainingExtension(typeName string, extNum int32, sentFileDescriptors map[string]bool) ([][]byte, error) {
-	st, err := typeForName(typeName)
-	if err != nil {
-		return nil, err
-	}
-	fd, err := fileDescContainingExtension(st, extNum)
-	if err != nil {
-		return nil, err
-	}
-	return fileDescWithDependencies(fd, sentFileDescriptors)
-}
-
-// allExtensionNumbersForTypeName returns all extension numbers for the given type.
-func (s *serverReflectionServer) allExtensionNumbersForTypeName(name string) ([]int32, error) {
-	st, err := typeForName(name)
-	if err != nil {
-		return nil, err
-	}
-	extNums, err := s.allExtensionNumbersForType(st)
-	if err != nil {
-		return nil, err
-	}
-	return extNums, nil
-}
-
-// ServerReflectionInfo is the reflection service handler.
-func (s *serverReflectionServer) ServerReflectionInfo(stream rpb.ServerReflection_ServerReflectionInfoServer) error {
-	sentFileDescriptors := make(map[string]bool)
-	for {
-		in, err := stream.Recv()
-		if err == io.EOF {
-			return nil
-		}
-		if err != nil {
-			return err
-		}
-
-		out := &rpb.ServerReflectionResponse{
-			ValidHost:       in.Host,
-			OriginalRequest: in,
-		}
-		switch req := in.MessageRequest.(type) {
-		case *rpb.ServerReflectionRequest_FileByFilename:
-			b, err := s.fileDescEncodingByFilename(req.FileByFilename, sentFileDescriptors)
-			if err != nil {
-				out.MessageResponse = &rpb.ServerReflectionResponse_ErrorResponse{
-					ErrorResponse: &rpb.ErrorResponse{
-						ErrorCode:    int32(codes.NotFound),
-						ErrorMessage: err.Error(),
-					},
-				}
-			} else {
-				out.MessageResponse = &rpb.ServerReflectionResponse_FileDescriptorResponse{
-					FileDescriptorResponse: &rpb.FileDescriptorResponse{FileDescriptorProto: b},
-				}
-			}
-		case *rpb.ServerReflectionRequest_FileContainingSymbol:
-			b, err := s.fileDescEncodingContainingSymbol(req.FileContainingSymbol, sentFileDescriptors)
-			if err != nil {
-				out.MessageResponse = &rpb.ServerReflectionResponse_ErrorResponse{
-					ErrorResponse: &rpb.ErrorResponse{
-						ErrorCode:    int32(codes.NotFound),
-						ErrorMessage: err.Error(),
-					},
-				}
-			} else {
-				out.MessageResponse = &rpb.ServerReflectionResponse_FileDescriptorResponse{
-					FileDescriptorResponse: &rpb.FileDescriptorResponse{FileDescriptorProto: b},
-				}
-			}
-		case *rpb.ServerReflectionRequest_FileContainingExtension:
-			typeName := req.FileContainingExtension.ContainingType
-			extNum := req.FileContainingExtension.ExtensionNumber
-			b, err := s.fileDescEncodingContainingExtension(typeName, extNum, sentFileDescriptors)
-			if err != nil {
-				out.MessageResponse = &rpb.ServerReflectionResponse_ErrorResponse{
-					ErrorResponse: &rpb.ErrorResponse{
-						ErrorCode:    int32(codes.NotFound),
-						ErrorMessage: err.Error(),
-					},
-				}
-			} else {
-				out.MessageResponse = &rpb.ServerReflectionResponse_FileDescriptorResponse{
-					FileDescriptorResponse: &rpb.FileDescriptorResponse{FileDescriptorProto: b},
-				}
-			}
-		case *rpb.ServerReflectionRequest_AllExtensionNumbersOfType:
-			extNums, err := s.allExtensionNumbersForTypeName(req.AllExtensionNumbersOfType)
-			if err != nil {
-				out.MessageResponse = &rpb.ServerReflectionResponse_ErrorResponse{
-					ErrorResponse: &rpb.ErrorResponse{
-						ErrorCode:    int32(codes.NotFound),
-						ErrorMessage: err.Error(),
-					},
-				}
-			} else {
-				out.MessageResponse = &rpb.ServerReflectionResponse_AllExtensionNumbersResponse{
-					AllExtensionNumbersResponse: &rpb.ExtensionNumberResponse{
-						BaseTypeName:    req.AllExtensionNumbersOfType,
-						ExtensionNumber: extNums,
-					},
-				}
-			}
-		case *rpb.ServerReflectionRequest_ListServices:
-			svcNames, _ := s.getSymbols()
-			serviceResponses := make([]*rpb.ServiceResponse, len(svcNames))
-			for i, n := range svcNames {
-				serviceResponses[i] = &rpb.ServiceResponse{
-					Name: n,
-				}
-			}
-			out.MessageResponse = &rpb.ServerReflectionResponse_ListServicesResponse{
-				ListServicesResponse: &rpb.ListServiceResponse{
-					Service: serviceResponses,
-				},
-			}
-		default:
-			return status.Errorf(codes.InvalidArgument, "invalid MessageRequest: %v", in.MessageRequest)
-		}
-
-		if err := stream.Send(out); err != nil {
-			return err
-		}
-	}
-}

reflection_old.go

@@ -0,0 +1,489 @@
+//go:build ignore
+// +build ignore
+
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+/*
+Package reflection implements server reflection service.
+
+The service implemented is defined in:
+https://github.com/grpc/grpc/blob/master/src/proto/grpc/reflection/v1alpha/reflection.proto.
+
+To register server reflection on a gRPC server:
+
+	import "google.golang.org/grpc/reflection"
+
+	s := grpc.NewServer()
+	pb.RegisterYourOwnServer(s, &server{})
+
+	// Register reflection service on gRPC server.
+	reflection.Register(s)
+
+	s.Serve(lis)
+*/
+package grpc
+
+import (
+	"bytes"
+	"compress/gzip"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"reflect"
+	"sort"
+	"sync"
+
+	"github.com/golang/protobuf/proto"
+	dpb "github.com/golang/protobuf/protoc-gen-go/descriptor"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	rpb "google.golang.org/grpc/reflection/grpc_reflection_v1alpha"
+	"google.golang.org/grpc/status"
+)
+
+type serverReflectionServer struct {
+	rpb.UnimplementedServerReflectionServer
+	s *grpc.Server
+
+	initSymbols  sync.Once
+	serviceNames []string
+	symbols      map[string]*dpb.FileDescriptorProto // map of fully-qualified names to files
+}
+
+// Register registers the server reflection service on the given gRPC server.
+func Register(s *grpc.Server) {
+	rpb.RegisterServerReflectionServer(s, &serverReflectionServer{
+		s: s,
+	})
+}
+
+// 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)
+}
+
+func (s *serverReflectionServer) getSymbols() (svcNames []string, symbolIndex map[string]*dpb.FileDescriptorProto) {
+	s.initSymbols.Do(func() {
+		serviceInfo := s.s.GetServiceInfo()
+
+		s.symbols = map[string]*dpb.FileDescriptorProto{}
+		s.serviceNames = make([]string, 0, len(serviceInfo))
+		processed := map[string]struct{}{}
+		for svc, info := range serviceInfo {
+			s.serviceNames = append(s.serviceNames, svc)
+			fdenc, ok := parseMetadata(info.Metadata)
+			if !ok {
+				continue
+			}
+			fd, err := decodeFileDesc(fdenc)
+			if err != nil {
+				continue
+			}
+			s.processFile(fd, processed)
+		}
+		sort.Strings(s.serviceNames)
+	})
+
+	return s.serviceNames, s.symbols
+}
+
+func (s *serverReflectionServer) processFile(fd *dpb.FileDescriptorProto, processed map[string]struct{}) {
+	filename := fd.GetName()
+	if _, ok := processed[filename]; ok {
+		return
+	}
+	processed[filename] = struct{}{}
+
+	prefix := fd.GetPackage()
+
+	for _, msg := range fd.MessageType {
+		s.processMessage(fd, prefix, msg)
+	}
+	for _, en := range fd.EnumType {
+		s.processEnum(fd, prefix, en)
+	}
+	for _, ext := range fd.Extension {
+		s.processField(fd, prefix, ext)
+	}
+	for _, svc := range fd.Service {
+		svcName := fqn(prefix, svc.GetName())
+		s.symbols[svcName] = fd
+		for _, meth := range svc.Method {
+			name := fqn(svcName, meth.GetName())
+			s.symbols[name] = fd
+		}
+	}
+
+	for _, dep := range fd.Dependency {
+		fdenc := proto.FileDescriptor(dep)
+		fdDep, err := decodeFileDesc(fdenc)
+		if err != nil {
+			continue
+		}
+		s.processFile(fdDep, processed)
+	}
+}
+
+func (s *serverReflectionServer) processMessage(fd *dpb.FileDescriptorProto, prefix string, msg *dpb.DescriptorProto) {
+	msgName := fqn(prefix, msg.GetName())
+	s.symbols[msgName] = fd
+
+	for _, nested := range msg.NestedType {
+		s.processMessage(fd, msgName, nested)
+	}
+	for _, en := range msg.EnumType {
+		s.processEnum(fd, msgName, en)
+	}
+	for _, ext := range msg.Extension {
+		s.processField(fd, msgName, ext)
+	}
+	for _, fld := range msg.Field {
+		s.processField(fd, msgName, fld)
+	}
+	for _, oneof := range msg.OneofDecl {
+		oneofName := fqn(msgName, oneof.GetName())
+		s.symbols[oneofName] = fd
+	}
+}
+
+func (s *serverReflectionServer) processEnum(fd *dpb.FileDescriptorProto, prefix string, en *dpb.EnumDescriptorProto) {
+	enName := fqn(prefix, en.GetName())
+	s.symbols[enName] = fd
+
+	for _, val := range en.Value {
+		valName := fqn(enName, val.GetName())
+		s.symbols[valName] = fd
+	}
+}
+
+func (s *serverReflectionServer) processField(fd *dpb.FileDescriptorProto, prefix string, fld *dpb.FieldDescriptorProto) {
+	fldName := fqn(prefix, fld.GetName())
+	s.symbols[fldName] = fd
+}
+
+func fqn(prefix, name string) string {
+	if prefix == "" {
+		return name
+	}
+	return prefix + "." + name
+}
+
+// fileDescForType gets the file descriptor for the given type.
+// The given type should be a proto message.
+func (s *serverReflectionServer) fileDescForType(st reflect.Type) (*dpb.FileDescriptorProto, error) {
+	m, ok := reflect.Zero(reflect.PtrTo(st)).Interface().(protoMessage)
+	if !ok {
+		return nil, fmt.Errorf("failed to create message from type: %v", st)
+	}
+	enc, _ := m.Descriptor()
+
+	return decodeFileDesc(enc)
+}
+
+// decodeFileDesc does decompression and unmarshalling on the given
+// file descriptor byte slice.
+func decodeFileDesc(enc []byte) (*dpb.FileDescriptorProto, error) {
+	raw, err := decompress(enc)
+	if err != nil {
+		return nil, fmt.Errorf("failed to decompress enc: %v", err)
+	}
+
+	fd := new(dpb.FileDescriptorProto)
+	if err := proto.Unmarshal(raw, fd); err != nil {
+		return nil, fmt.Errorf("bad descriptor: %v", err)
+	}
+	return fd, nil
+}
+
+// decompress does gzip decompression.
+func decompress(b []byte) ([]byte, error) {
+	r, err := gzip.NewReader(bytes.NewReader(b))
+	if err != nil {
+		return nil, fmt.Errorf("bad gzipped descriptor: %v", err)
+	}
+	out, err := ioutil.ReadAll(r)
+	if err != nil {
+		return nil, fmt.Errorf("bad gzipped descriptor: %v", err)
+	}
+	return out, nil
+}
+
+func typeForName(name string) (reflect.Type, error) {
+	pt := proto.MessageType(name)
+	if pt == nil {
+		return nil, fmt.Errorf("unknown type: %q", name)
+	}
+	st := pt.Elem()
+
+	return st, nil
+}
+
+func fileDescContainingExtension(st reflect.Type, ext int32) (*dpb.FileDescriptorProto, error) {
+	m, ok := reflect.Zero(reflect.PtrTo(st)).Interface().(proto.Message)
+	if !ok {
+		return nil, fmt.Errorf("failed to create message from type: %v", st)
+	}
+
+	var extDesc *proto.ExtensionDesc
+	for id, desc := range proto.RegisteredExtensions(m) {
+		if id == ext {
+			extDesc = desc
+			break
+		}
+	}
+
+	if extDesc == nil {
+		return nil, fmt.Errorf("failed to find registered extension for extension number %v", ext)
+	}
+
+	return decodeFileDesc(proto.FileDescriptor(extDesc.Filename))
+}
+
+func (s *serverReflectionServer) allExtensionNumbersForType(st reflect.Type) ([]int32, error) {
+	m, ok := reflect.Zero(reflect.PtrTo(st)).Interface().(proto.Message)
+	if !ok {
+		return nil, fmt.Errorf("failed to create message from type: %v", st)
+	}
+
+	exts := proto.RegisteredExtensions(m)
+	out := make([]int32, 0, len(exts))
+	for id := range exts {
+		out = append(out, id)
+	}
+	return out, nil
+}
+
+// fileDescWithDependencies returns a slice of serialized fileDescriptors in
+// wire format ([]byte). The fileDescriptors will include fd and all the
+// transitive dependencies of fd with names not in sentFileDescriptors.
+func fileDescWithDependencies(fd *dpb.FileDescriptorProto, sentFileDescriptors map[string]bool) ([][]byte, error) {
+	r := [][]byte{}
+	queue := []*dpb.FileDescriptorProto{fd}
+	for len(queue) > 0 {
+		currentfd := queue[0]
+		queue = queue[1:]
+		if sent := sentFileDescriptors[currentfd.GetName()]; len(r) == 0 || !sent {
+			sentFileDescriptors[currentfd.GetName()] = true
+			currentfdEncoded, err := proto.Marshal(currentfd)
+			if err != nil {
+				return nil, err
+			}
+			r = append(r, currentfdEncoded)
+		}
+		for _, dep := range currentfd.Dependency {
+			fdenc := proto.FileDescriptor(dep)
+			fdDep, err := decodeFileDesc(fdenc)
+			if err != nil {
+				continue
+			}
+			queue = append(queue, fdDep)
+		}
+	}
+	return r, nil
+}
+
+// fileDescEncodingByFilename finds the file descriptor for given filename,
+// finds all of its previously unsent transitive dependencies, does marshalling
+// on them, and returns the marshalled result.
+func (s *serverReflectionServer) fileDescEncodingByFilename(name string, sentFileDescriptors map[string]bool) ([][]byte, error) {
+	enc := proto.FileDescriptor(name)
+	if enc == nil {
+		return nil, fmt.Errorf("unknown file: %v", name)
+	}
+	fd, err := decodeFileDesc(enc)
+	if err != nil {
+		return nil, err
+	}
+	return fileDescWithDependencies(fd, sentFileDescriptors)
+}
+
+// parseMetadata finds the file descriptor bytes specified meta.
+// For SupportPackageIsVersion4, m is the name of the proto file, we
+// call proto.FileDescriptor to get the byte slice.
+// For SupportPackageIsVersion3, m is a byte slice itself.
+func parseMetadata(meta interface{}) ([]byte, bool) {
+	// Check if meta is the file name.
+	if fileNameForMeta, ok := meta.(string); ok {
+		return proto.FileDescriptor(fileNameForMeta), true
+	}
+
+	// Check if meta is the byte slice.
+	if enc, ok := meta.([]byte); ok {
+		return enc, true
+	}
+
+	return nil, false
+}
+
+// fileDescEncodingContainingSymbol finds the file descriptor containing the
+// given symbol, finds all of its previously unsent transitive dependencies,
+// does marshalling on them, and returns the marshalled result. The given symbol
+// can be a type, a service or a method.
+func (s *serverReflectionServer) fileDescEncodingContainingSymbol(name string, sentFileDescriptors map[string]bool) ([][]byte, error) {
+	_, symbols := s.getSymbols()
+	fd := symbols[name]
+	if fd == nil {
+		// Check if it's a type name that was not present in the
+		// transitive dependencies of the registered services.
+		if st, err := typeForName(name); err == nil {
+			fd, err = s.fileDescForType(st)
+			if err != nil {
+				return nil, err
+			}
+		}
+	}
+
+	if fd == nil {
+		return nil, fmt.Errorf("unknown symbol: %v", name)
+	}
+
+	return fileDescWithDependencies(fd, sentFileDescriptors)
+}
+
+// fileDescEncodingContainingExtension finds the file descriptor containing
+// given extension, finds all of its previously unsent transitive dependencies,
+// does marshalling on them, and returns the marshalled result.
+func (s *serverReflectionServer) fileDescEncodingContainingExtension(typeName string, extNum int32, sentFileDescriptors map[string]bool) ([][]byte, error) {
+	st, err := typeForName(typeName)
+	if err != nil {
+		return nil, err
+	}
+	fd, err := fileDescContainingExtension(st, extNum)
+	if err != nil {
+		return nil, err
+	}
+	return fileDescWithDependencies(fd, sentFileDescriptors)
+}
+
+// allExtensionNumbersForTypeName returns all extension numbers for the given type.
+func (s *serverReflectionServer) allExtensionNumbersForTypeName(name string) ([]int32, error) {
+	st, err := typeForName(name)
+	if err != nil {
+		return nil, err
+	}
+	extNums, err := s.allExtensionNumbersForType(st)
+	if err != nil {
+		return nil, err
+	}
+	return extNums, nil
+}
+
+// ServerReflectionInfo is the reflection service handler.
+func (s *serverReflectionServer) ServerReflectionInfo(stream rpb.ServerReflection_ServerReflectionInfoServer) error {
+	sentFileDescriptors := make(map[string]bool)
+	for {
+		in, err := stream.Recv()
+		if err == io.EOF {
+			return nil
+		}
+		if err != nil {
+			return err
+		}
+
+		out := &rpb.ServerReflectionResponse{
+			ValidHost:       in.Host,
+			OriginalRequest: in,
+		}
+		switch req := in.MessageRequest.(type) {
+		case *rpb.ServerReflectionRequest_FileByFilename:
+			b, err := s.fileDescEncodingByFilename(req.FileByFilename, sentFileDescriptors)
+			if err != nil {
+				out.MessageResponse = &rpb.ServerReflectionResponse_ErrorResponse{
+					ErrorResponse: &rpb.ErrorResponse{
+						ErrorCode:    int32(codes.NotFound),
+						ErrorMessage: err.Error(),
+					},
+				}
+			} else {
+				out.MessageResponse = &rpb.ServerReflectionResponse_FileDescriptorResponse{
+					FileDescriptorResponse: &rpb.FileDescriptorResponse{FileDescriptorProto: b},
+				}
+			}
+		case *rpb.ServerReflectionRequest_FileContainingSymbol:
+			b, err := s.fileDescEncodingContainingSymbol(req.FileContainingSymbol, sentFileDescriptors)
+			if err != nil {
+				out.MessageResponse = &rpb.ServerReflectionResponse_ErrorResponse{
+					ErrorResponse: &rpb.ErrorResponse{
+						ErrorCode:    int32(codes.NotFound),
+						ErrorMessage: err.Error(),
+					},
+				}
+			} else {
+				out.MessageResponse = &rpb.ServerReflectionResponse_FileDescriptorResponse{
+					FileDescriptorResponse: &rpb.FileDescriptorResponse{FileDescriptorProto: b},
+				}
+			}
+		case *rpb.ServerReflectionRequest_FileContainingExtension:
+			typeName := req.FileContainingExtension.ContainingType
+			extNum := req.FileContainingExtension.ExtensionNumber
+			b, err := s.fileDescEncodingContainingExtension(typeName, extNum, sentFileDescriptors)
+			if err != nil {
+				out.MessageResponse = &rpb.ServerReflectionResponse_ErrorResponse{
+					ErrorResponse: &rpb.ErrorResponse{
+						ErrorCode:    int32(codes.NotFound),
+						ErrorMessage: err.Error(),
+					},
+				}
+			} else {
+				out.MessageResponse = &rpb.ServerReflectionResponse_FileDescriptorResponse{
+					FileDescriptorResponse: &rpb.FileDescriptorResponse{FileDescriptorProto: b},
+				}
+			}
+		case *rpb.ServerReflectionRequest_AllExtensionNumbersOfType:
+			extNums, err := s.allExtensionNumbersForTypeName(req.AllExtensionNumbersOfType)
+			if err != nil {
+				out.MessageResponse = &rpb.ServerReflectionResponse_ErrorResponse{
+					ErrorResponse: &rpb.ErrorResponse{
+						ErrorCode:    int32(codes.NotFound),
+						ErrorMessage: err.Error(),
+					},
+				}
+			} else {
+				out.MessageResponse = &rpb.ServerReflectionResponse_AllExtensionNumbersResponse{
+					AllExtensionNumbersResponse: &rpb.ExtensionNumberResponse{
+						BaseTypeName:    req.AllExtensionNumbersOfType,
+						ExtensionNumber: extNums,
+					},
+				}
+			}
+		case *rpb.ServerReflectionRequest_ListServices:
+			svcNames, _ := s.getSymbols()
+			serviceResponses := make([]*rpb.ServiceResponse, len(svcNames))
+			for i, n := range svcNames {
+				serviceResponses[i] = &rpb.ServiceResponse{
+					Name: n,
+				}
+			}
+			out.MessageResponse = &rpb.ServerReflectionResponse_ListServicesResponse{
+				ListServicesResponse: &rpb.ListServiceResponse{
+					Service: serviceResponses,
+				},
+			}
+		default:
+			return status.Errorf(codes.InvalidArgument, "invalid MessageRequest: %v", in.MessageRequest)
+		}
+
+		if err := stream.Send(out); err != nil {
+			return err
+		}
+	}
+}