diff --git a/vendor/github.com/jhump/protoreflect/desc/descriptor.go b/vendor/github.com/jhump/protoreflect/desc/descriptor.go
new file mode 100644
index 0000000..42f0f8e
--- /dev/null
+++ b/vendor/github.com/jhump/protoreflect/desc/descriptor.go
@@ -0,0 +1,1723 @@
+package desc
+
+import (
+	"bytes"
+	"fmt"
+	"sort"
+	"strconv"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+
+	"github.com/golang/protobuf/proto"
+	dpb "github.com/golang/protobuf/protoc-gen-go/descriptor"
+
+	"github.com/jhump/protoreflect/desc/internal"
+)
+
+// Descriptor is the common interface implemented by all descriptor objects.
+type Descriptor interface {
+	// GetName returns the name of the object described by the descriptor. This will
+	// be a base name that does not include enclosing message names or the package name.
+	// For file descriptors, this indicates the path and name to the described file.
+	GetName() string
+	// GetFullyQualifiedName returns the fully-qualified name of the object described by
+	// the descriptor. This will include the package name and any enclosing message names.
+	// For file descriptors, this returns the path and name to the described file (same as
+	// GetName).
+	GetFullyQualifiedName() string
+	// GetParent returns the enclosing element in a proto source file. If the described
+	// object is a top-level object, this returns the file descriptor. Otherwise, it returns
+	// the element in which the described object was declared. File descriptors have no
+	// parent and return nil.
+	GetParent() Descriptor
+	// GetFile returns the file descriptor in which this element was declared. File
+	// descriptors return themselves.
+	GetFile() *FileDescriptor
+	// GetOptions returns the options proto containing options for the described element.
+	GetOptions() proto.Message
+	// GetSourceInfo returns any source code information that was present in the file
+	// descriptor. Source code info is optional. If no source code info is available for
+	// the element (including if there is none at all in the file descriptor) then this
+	// returns nil
+	GetSourceInfo() *dpb.SourceCodeInfo_Location
+	// AsProto returns the underlying descriptor proto for this descriptor.
+	AsProto() proto.Message
+}
+
+type sourceInfoRecomputeFunc = internal.SourceInfoComputeFunc
+
+// FileDescriptor describes a proto source file.
+type FileDescriptor struct {
+	proto      *dpb.FileDescriptorProto
+	symbols    map[string]Descriptor
+	deps       []*FileDescriptor
+	publicDeps []*FileDescriptor
+	weakDeps   []*FileDescriptor
+	messages   []*MessageDescriptor
+	enums      []*EnumDescriptor
+	extensions []*FieldDescriptor
+	services   []*ServiceDescriptor
+	fieldIndex map[string]map[int32]*FieldDescriptor
+	isProto3   bool
+	sourceInfo internal.SourceInfoMap
+	sourceInfoRecomputeFunc
+}
+
+func (fd *FileDescriptor) recomputeSourceInfo() {
+	internal.PopulateSourceInfoMap(fd.proto, fd.sourceInfo)
+}
+
+func (fd *FileDescriptor) registerField(field *FieldDescriptor) {
+	fields := fd.fieldIndex[field.owner.GetFullyQualifiedName()]
+	if fields == nil {
+		fields = map[int32]*FieldDescriptor{}
+		fd.fieldIndex[field.owner.GetFullyQualifiedName()] = fields
+	}
+	fields[field.GetNumber()] = field
+}
+
+// GetName returns the name of the file, as it was given to the protoc invocation
+// to compile it, possibly including path (relative to a directory in the proto
+// import path).
+func (fd *FileDescriptor) GetName() string {
+	return fd.proto.GetName()
+}
+
+// GetFullyQualifiedName returns the name of the file, same as GetName. It is
+// present to satisfy the Descriptor interface.
+func (fd *FileDescriptor) GetFullyQualifiedName() string {
+	return fd.proto.GetName()
+}
+
+// GetPackage returns the name of the package declared in the file.
+func (fd *FileDescriptor) GetPackage() string {
+	return fd.proto.GetPackage()
+}
+
+// GetParent always returns nil: files are the root of descriptor hierarchies.
+// Is it present to satisfy the Descriptor interface.
+func (fd *FileDescriptor) GetParent() Descriptor {
+	return nil
+}
+
+// GetFile returns the receiver, which is a file descriptor. This is present
+// to satisfy the Descriptor interface.
+func (fd *FileDescriptor) GetFile() *FileDescriptor {
+	return fd
+}
+
+// GetOptions returns the file's options. Most usages will be more interested
+// in GetFileOptions, which has a concrete return type. This generic version
+// is present to satisfy the Descriptor interface.
+func (fd *FileDescriptor) GetOptions() proto.Message {
+	return fd.proto.GetOptions()
+}
+
+// GetFileOptions returns the file's options.
+func (fd *FileDescriptor) GetFileOptions() *dpb.FileOptions {
+	return fd.proto.GetOptions()
+}
+
+// GetSourceInfo returns nil for files. It is present to satisfy the Descriptor
+// interface.
+func (fd *FileDescriptor) GetSourceInfo() *dpb.SourceCodeInfo_Location {
+	return nil
+}
+
+// AsProto returns the underlying descriptor proto. Most usages will be more
+// interested in AsFileDescriptorProto, which has a concrete return type. This
+// generic version is present to satisfy the Descriptor interface.
+func (fd *FileDescriptor) AsProto() proto.Message {
+	return fd.proto
+}
+
+// AsFileDescriptorProto returns the underlying descriptor proto.
+func (fd *FileDescriptor) AsFileDescriptorProto() *dpb.FileDescriptorProto {
+	return fd.proto
+}
+
+// String returns the underlying descriptor proto, in compact text format.
+func (fd *FileDescriptor) String() string {
+	return fd.proto.String()
+}
+
+// IsProto3 returns true if the file declares a syntax of "proto3".
+func (fd *FileDescriptor) IsProto3() bool {
+	return fd.isProto3
+}
+
+// GetDependencies returns all of this file's dependencies. These correspond to
+// import statements in the file.
+func (fd *FileDescriptor) GetDependencies() []*FileDescriptor {
+	return fd.deps
+}
+
+// GetPublicDependencies returns all of this file's public dependencies. These
+// correspond to public import statements in the file.
+func (fd *FileDescriptor) GetPublicDependencies() []*FileDescriptor {
+	return fd.publicDeps
+}
+
+// GetWeakDependencies returns all of this file's weak dependencies. These
+// correspond to weak import statements in the file.
+func (fd *FileDescriptor) GetWeakDependencies() []*FileDescriptor {
+	return fd.weakDeps
+}
+
+// GetMessageTypes returns all top-level messages declared in this file.
+func (fd *FileDescriptor) GetMessageTypes() []*MessageDescriptor {
+	return fd.messages
+}
+
+// GetEnumTypes returns all top-level enums declared in this file.
+func (fd *FileDescriptor) GetEnumTypes() []*EnumDescriptor {
+	return fd.enums
+}
+
+// GetExtensions returns all top-level extensions declared in this file.
+func (fd *FileDescriptor) GetExtensions() []*FieldDescriptor {
+	return fd.extensions
+}
+
+// GetServices returns all services declared in this file.
+func (fd *FileDescriptor) GetServices() []*ServiceDescriptor {
+	return fd.services
+}
+
+// FindSymbol returns the descriptor contained within this file for the
+// element with the given fully-qualified symbol name. If no such element
+// exists then this method returns nil.
+func (fd *FileDescriptor) FindSymbol(symbol string) Descriptor {
+	if symbol[0] == '.' {
+		symbol = symbol[1:]
+	}
+	if ret := fd.symbols[symbol]; ret != nil {
+		return ret
+	}
+
+	// allow accessing symbols through public imports, too
+	for _, dep := range fd.GetPublicDependencies() {
+		if ret := dep.FindSymbol(symbol); ret != nil {
+			return ret
+		}
+	}
+
+	// not found
+	return nil
+}
+
+// FindMessage finds the message with the given fully-qualified name. If no
+// such element exists in this file then nil is returned.
+func (fd *FileDescriptor) FindMessage(msgName string) *MessageDescriptor {
+	if md, ok := fd.symbols[msgName].(*MessageDescriptor); ok {
+		return md
+	} else {
+		return nil
+	}
+}
+
+// FindEnum finds the enum with the given fully-qualified name. If no such
+// element exists in this file then nil is returned.
+func (fd *FileDescriptor) FindEnum(enumName string) *EnumDescriptor {
+	if ed, ok := fd.symbols[enumName].(*EnumDescriptor); ok {
+		return ed
+	} else {
+		return nil
+	}
+}
+
+// FindService finds the service with the given fully-qualified name. If no
+// such element exists in this file then nil is returned.
+func (fd *FileDescriptor) FindService(serviceName string) *ServiceDescriptor {
+	if sd, ok := fd.symbols[serviceName].(*ServiceDescriptor); ok {
+		return sd
+	} else {
+		return nil
+	}
+}
+
+// FindExtension finds the extension field for the given extended type name and
+// tag number. If no such element exists in this file then nil is returned.
+func (fd *FileDescriptor) FindExtension(extendeeName string, tagNumber int32) *FieldDescriptor {
+	if exd, ok := fd.fieldIndex[extendeeName][tagNumber]; ok && exd.IsExtension() {
+		return exd
+	} else {
+		return nil
+	}
+}
+
+// FindExtensionByName finds the extension field with the given fully-qualified
+// name. If no such element exists in this file then nil is returned.
+func (fd *FileDescriptor) FindExtensionByName(extName string) *FieldDescriptor {
+	if exd, ok := fd.symbols[extName].(*FieldDescriptor); ok && exd.IsExtension() {
+		return exd
+	} else {
+		return nil
+	}
+}
+
+// MessageDescriptor describes a protocol buffer message.
+type MessageDescriptor struct {
+	proto          *dpb.DescriptorProto
+	parent         Descriptor
+	file           *FileDescriptor
+	fields         []*FieldDescriptor
+	nested         []*MessageDescriptor
+	enums          []*EnumDescriptor
+	extensions     []*FieldDescriptor
+	oneOfs         []*OneOfDescriptor
+	extRanges      extRanges
+	fqn            string
+	sourceInfoPath []int32
+	jsonNames      jsonNameMap
+	isProto3       bool
+	isMapEntry     bool
+}
+
+func createMessageDescriptor(fd *FileDescriptor, parent Descriptor, enclosing string, md *dpb.DescriptorProto, symbols map[string]Descriptor) (*MessageDescriptor, string) {
+	msgName := merge(enclosing, md.GetName())
+	ret := &MessageDescriptor{proto: md, parent: parent, file: fd, fqn: msgName}
+	for _, f := range md.GetField() {
+		fld, n := createFieldDescriptor(fd, ret, msgName, f)
+		symbols[n] = fld
+		ret.fields = append(ret.fields, fld)
+	}
+	for _, nm := range md.NestedType {
+		nmd, n := createMessageDescriptor(fd, ret, msgName, nm, symbols)
+		symbols[n] = nmd
+		ret.nested = append(ret.nested, nmd)
+	}
+	for _, e := range md.EnumType {
+		ed, n := createEnumDescriptor(fd, ret, msgName, e, symbols)
+		symbols[n] = ed
+		ret.enums = append(ret.enums, ed)
+	}
+	for _, ex := range md.GetExtension() {
+		exd, n := createFieldDescriptor(fd, ret, msgName, ex)
+		symbols[n] = exd
+		ret.extensions = append(ret.extensions, exd)
+	}
+	for i, o := range md.GetOneofDecl() {
+		od, n := createOneOfDescriptor(fd, ret, i, msgName, o)
+		symbols[n] = od
+		ret.oneOfs = append(ret.oneOfs, od)
+	}
+	for _, r := range md.GetExtensionRange() {
+		// proto.ExtensionRange is inclusive (and that's how extension ranges are defined in code).
+		// but protoc converts range to exclusive end in descriptor, so we must convert back
+		end := r.GetEnd() - 1
+		ret.extRanges = append(ret.extRanges, proto.ExtensionRange{
+			Start: r.GetStart(),
+			End:   end})
+	}
+	sort.Sort(ret.extRanges)
+	ret.isProto3 = fd.isProto3
+	ret.isMapEntry = md.GetOptions().GetMapEntry() &&
+		len(ret.fields) == 2 &&
+		ret.fields[0].GetNumber() == 1 &&
+		ret.fields[1].GetNumber() == 2
+
+	return ret, msgName
+}
+
+func (md *MessageDescriptor) resolve(path []int32, scopes []scope) error {
+	md.sourceInfoPath = append([]int32(nil), path...) // defensive copy
+	path = append(path, internal.Message_nestedMessagesTag)
+	scopes = append(scopes, messageScope(md))
+	for i, nmd := range md.nested {
+		if err := nmd.resolve(append(path, int32(i)), scopes); err != nil {
+			return err
+		}
+	}
+	path[len(path)-1] = internal.Message_enumsTag
+	for i, ed := range md.enums {
+		ed.resolve(append(path, int32(i)))
+	}
+	path[len(path)-1] = internal.Message_fieldsTag
+	for i, fld := range md.fields {
+		if err := fld.resolve(append(path, int32(i)), scopes); err != nil {
+			return err
+		}
+	}
+	path[len(path)-1] = internal.Message_extensionsTag
+	for i, exd := range md.extensions {
+		if err := exd.resolve(append(path, int32(i)), scopes); err != nil {
+			return err
+		}
+	}
+	path[len(path)-1] = internal.Message_oneOfsTag
+	for i, od := range md.oneOfs {
+		od.resolve(append(path, int32(i)))
+	}
+	return nil
+}
+
+// GetName returns the simple (unqualified) name of the message.
+func (md *MessageDescriptor) GetName() string {
+	return md.proto.GetName()
+}
+
+// GetFullyQualifiedName returns the fully qualified name of the message. This
+// includes the package name (if there is one) as well as the names of any
+// enclosing messages.
+func (md *MessageDescriptor) GetFullyQualifiedName() string {
+	return md.fqn
+}
+
+// GetParent returns the message's enclosing descriptor. For top-level messages,
+// this will be a file descriptor. Otherwise it will be the descriptor for the
+// enclosing message.
+func (md *MessageDescriptor) GetParent() Descriptor {
+	return md.parent
+}
+
+// GetFile returns the descriptor for the file in which this message is defined.
+func (md *MessageDescriptor) GetFile() *FileDescriptor {
+	return md.file
+}
+
+// GetOptions returns the message's options. Most usages will be more interested
+// in GetMessageOptions, which has a concrete return type. This generic version
+// is present to satisfy the Descriptor interface.
+func (md *MessageDescriptor) GetOptions() proto.Message {
+	return md.proto.GetOptions()
+}
+
+// GetMessageOptions returns the message's options.
+func (md *MessageDescriptor) GetMessageOptions() *dpb.MessageOptions {
+	return md.proto.GetOptions()
+}
+
+// GetSourceInfo returns source info for the message, if present in the
+// descriptor. Not all descriptors will contain source info. If non-nil, the
+// returned info contains information about the location in the file where the
+// message was defined and also contains comments associated with the message
+// definition.
+func (md *MessageDescriptor) GetSourceInfo() *dpb.SourceCodeInfo_Location {
+	return md.file.sourceInfo.Get(md.sourceInfoPath)
+}
+
+// AsProto returns the underlying descriptor proto. Most usages will be more
+// interested in AsDescriptorProto, which has a concrete return type. This
+// generic version is present to satisfy the Descriptor interface.
+func (md *MessageDescriptor) AsProto() proto.Message {
+	return md.proto
+}
+
+// AsDescriptorProto returns the underlying descriptor proto.
+func (md *MessageDescriptor) AsDescriptorProto() *dpb.DescriptorProto {
+	return md.proto
+}
+
+// String returns the underlying descriptor proto, in compact text format.
+func (md *MessageDescriptor) String() string {
+	return md.proto.String()
+}
+
+// IsMapEntry returns true if this is a synthetic message type that represents an entry
+// in a map field.
+func (md *MessageDescriptor) IsMapEntry() bool {
+	return md.isMapEntry
+}
+
+// GetFields returns all of the fields for this message.
+func (md *MessageDescriptor) GetFields() []*FieldDescriptor {
+	return md.fields
+}
+
+// GetNestedMessageTypes returns all of the message types declared inside this message.
+func (md *MessageDescriptor) GetNestedMessageTypes() []*MessageDescriptor {
+	return md.nested
+}
+
+// GetNestedEnumTypes returns all of the enums declared inside this message.
+func (md *MessageDescriptor) GetNestedEnumTypes() []*EnumDescriptor {
+	return md.enums
+}
+
+// GetNestedExtensions returns all of the extensions declared inside this message.
+func (md *MessageDescriptor) GetNestedExtensions() []*FieldDescriptor {
+	return md.extensions
+}
+
+// GetOneOfs returns all of the one-of field sets declared inside this message.
+func (md *MessageDescriptor) GetOneOfs() []*OneOfDescriptor {
+	return md.oneOfs
+}
+
+// IsProto3 returns true if the file in which this message is defined declares a syntax of "proto3".
+func (md *MessageDescriptor) IsProto3() bool {
+	return md.isProto3
+}
+
+// GetExtensionRanges returns the ranges of extension field numbers for this message.
+func (md *MessageDescriptor) GetExtensionRanges() []proto.ExtensionRange {
+	return md.extRanges
+}
+
+// IsExtendable returns true if this message has any extension ranges.
+func (md *MessageDescriptor) IsExtendable() bool {
+	return len(md.extRanges) > 0
+}
+
+// IsExtension returns true if the given tag number is within any of this message's
+// extension ranges.
+func (md *MessageDescriptor) IsExtension(tagNumber int32) bool {
+	return md.extRanges.IsExtension(tagNumber)
+}
+
+type extRanges []proto.ExtensionRange
+
+func (er extRanges) String() string {
+	var buf bytes.Buffer
+	first := true
+	for _, r := range er {
+		if first {
+			first = false
+		} else {
+			buf.WriteString(",")
+		}
+		fmt.Fprintf(&buf, "%d..%d", r.Start, r.End)
+	}
+	return buf.String()
+}
+
+func (er extRanges) IsExtension(tagNumber int32) bool {
+	i := sort.Search(len(er), func(i int) bool { return er[i].End >= tagNumber })
+	return i < len(er) && tagNumber >= er[i].Start
+}
+
+func (er extRanges) Len() int {
+	return len(er)
+}
+
+func (er extRanges) Less(i, j int) bool {
+	return er[i].Start < er[j].Start
+}
+
+func (er extRanges) Swap(i, j int) {
+	er[i], er[j] = er[j], er[i]
+}
+
+// FindFieldByName finds the field with the given name. If no such field exists
+// then nil is returned. Only regular fields are returned, not extensions.
+func (md *MessageDescriptor) FindFieldByName(fieldName string) *FieldDescriptor {
+	fqn := fmt.Sprintf("%s.%s", md.fqn, fieldName)
+	if fd, ok := md.file.symbols[fqn].(*FieldDescriptor); ok && !fd.IsExtension() {
+		return fd
+	} else {
+		return nil
+	}
+}
+
+// FindFieldByNumber finds the field with the given tag number. If no such field
+// exists then nil is returned. Only regular fields are returned, not extensions.
+func (md *MessageDescriptor) FindFieldByNumber(tagNumber int32) *FieldDescriptor {
+	if fd, ok := md.file.fieldIndex[md.fqn][tagNumber]; ok && !fd.IsExtension() {
+		return fd
+	} else {
+		return nil
+	}
+}
+
+// FieldDescriptor describes a field of a protocol buffer message.
+type FieldDescriptor struct {
+	proto          *dpb.FieldDescriptorProto
+	parent         Descriptor
+	owner          *MessageDescriptor
+	file           *FileDescriptor
+	oneOf          *OneOfDescriptor
+	msgType        *MessageDescriptor
+	enumType       *EnumDescriptor
+	fqn            string
+	sourceInfoPath []int32
+	def            memoizedDefault
+	isMap          bool
+}
+
+func createFieldDescriptor(fd *FileDescriptor, parent Descriptor, enclosing string, fld *dpb.FieldDescriptorProto) (*FieldDescriptor, string) {
+	fldName := merge(enclosing, fld.GetName())
+	ret := &FieldDescriptor{proto: fld, parent: parent, file: fd, fqn: fldName}
+	if fld.GetExtendee() == "" {
+		ret.owner = parent.(*MessageDescriptor)
+	}
+	// owner for extensions, field type (be it message or enum), and one-ofs get resolved later
+	return ret, fldName
+}
+
+func (fd *FieldDescriptor) resolve(path []int32, scopes []scope) error {
+	if fd.proto.OneofIndex != nil && fd.oneOf == nil {
+		return fmt.Errorf("could not link field %s to one-of index %d", fd.fqn, *fd.proto.OneofIndex)
+	}
+	fd.sourceInfoPath = append([]int32(nil), path...) // defensive copy
+	if fd.proto.GetType() == dpb.FieldDescriptorProto_TYPE_ENUM {
+		if desc, err := resolve(fd.file, fd.proto.GetTypeName(), scopes); err != nil {
+			return err
+		} else {
+			fd.enumType = desc.(*EnumDescriptor)
+		}
+	}
+	if fd.proto.GetType() == dpb.FieldDescriptorProto_TYPE_MESSAGE || fd.proto.GetType() == dpb.FieldDescriptorProto_TYPE_GROUP {
+		if desc, err := resolve(fd.file, fd.proto.GetTypeName(), scopes); err != nil {
+			return err
+		} else {
+			fd.msgType = desc.(*MessageDescriptor)
+		}
+	}
+	if fd.proto.GetExtendee() != "" {
+		if desc, err := resolve(fd.file, fd.proto.GetExtendee(), scopes); err != nil {
+			return err
+		} else {
+			fd.owner = desc.(*MessageDescriptor)
+		}
+	}
+	fd.file.registerField(fd)
+	fd.isMap = fd.proto.GetLabel() == dpb.FieldDescriptorProto_LABEL_REPEATED &&
+		fd.proto.GetType() == dpb.FieldDescriptorProto_TYPE_MESSAGE &&
+		fd.GetMessageType().IsMapEntry()
+	return nil
+}
+
+func (fd *FieldDescriptor) determineDefault() interface{} {
+	if fd.IsMap() {
+		return map[interface{}]interface{}(nil)
+	} else if fd.IsRepeated() {
+		return []interface{}(nil)
+	} else if fd.msgType != nil {
+		return nil
+	}
+
+	proto3 := fd.file.isProto3
+	if !proto3 {
+		def := fd.AsFieldDescriptorProto().GetDefaultValue()
+		if def != "" {
+			ret := parseDefaultValue(fd, def)
+			if ret != nil {
+				return ret
+			}
+			// if we can't parse default value, fall-through to return normal default...
+		}
+	}
+
+	switch fd.GetType() {
+	case dpb.FieldDescriptorProto_TYPE_FIXED32,
+		dpb.FieldDescriptorProto_TYPE_UINT32:
+		return uint32(0)
+	case dpb.FieldDescriptorProto_TYPE_SFIXED32,
+		dpb.FieldDescriptorProto_TYPE_INT32,
+		dpb.FieldDescriptorProto_TYPE_SINT32:
+		return int32(0)
+	case dpb.FieldDescriptorProto_TYPE_FIXED64,
+		dpb.FieldDescriptorProto_TYPE_UINT64:
+		return uint64(0)
+	case dpb.FieldDescriptorProto_TYPE_SFIXED64,
+		dpb.FieldDescriptorProto_TYPE_INT64,
+		dpb.FieldDescriptorProto_TYPE_SINT64:
+		return int64(0)
+	case dpb.FieldDescriptorProto_TYPE_FLOAT:
+		return float32(0.0)
+	case dpb.FieldDescriptorProto_TYPE_DOUBLE:
+		return float64(0.0)
+	case dpb.FieldDescriptorProto_TYPE_BOOL:
+		return false
+	case dpb.FieldDescriptorProto_TYPE_BYTES:
+		return []byte(nil)
+	case dpb.FieldDescriptorProto_TYPE_STRING:
+		return ""
+	case dpb.FieldDescriptorProto_TYPE_ENUM:
+		if proto3 {
+			return int32(0)
+		}
+		enumVals := fd.GetEnumType().GetValues()
+		if len(enumVals) > 0 {
+			return enumVals[0].GetNumber()
+		} else {
+			return int32(0) // WTF?
+		}
+	default:
+		panic(fmt.Sprintf("Unknown field type: %v", fd.GetType()))
+	}
+}
+
+func parseDefaultValue(fd *FieldDescriptor, val string) interface{} {
+	switch fd.GetType() {
+	case dpb.FieldDescriptorProto_TYPE_ENUM:
+		vd := fd.GetEnumType().FindValueByName(val)
+		if vd != nil {
+			return vd.GetNumber()
+		}
+		return nil
+	case dpb.FieldDescriptorProto_TYPE_BOOL:
+		if val == "true" {
+			return true
+		} else if val == "false" {
+			return false
+		}
+		return nil
+	case dpb.FieldDescriptorProto_TYPE_BYTES:
+		return []byte(unescape(val))
+	case dpb.FieldDescriptorProto_TYPE_STRING:
+		return val
+	case dpb.FieldDescriptorProto_TYPE_FLOAT:
+		if f, err := strconv.ParseFloat(val, 32); err == nil {
+			return float32(f)
+		} else {
+			return float32(0)
+		}
+	case dpb.FieldDescriptorProto_TYPE_DOUBLE:
+		if f, err := strconv.ParseFloat(val, 64); err == nil {
+			return f
+		} else {
+			return float64(0)
+		}
+	case dpb.FieldDescriptorProto_TYPE_INT32,
+		dpb.FieldDescriptorProto_TYPE_SINT32,
+		dpb.FieldDescriptorProto_TYPE_SFIXED32:
+		if i, err := strconv.ParseInt(val, 10, 32); err == nil {
+			return int32(i)
+		} else {
+			return int32(0)
+		}
+	case dpb.FieldDescriptorProto_TYPE_UINT32,
+		dpb.FieldDescriptorProto_TYPE_FIXED32:
+		if i, err := strconv.ParseUint(val, 10, 32); err == nil {
+			return uint32(i)
+		} else {
+			return uint32(0)
+		}
+	case dpb.FieldDescriptorProto_TYPE_INT64,
+		dpb.FieldDescriptorProto_TYPE_SINT64,
+		dpb.FieldDescriptorProto_TYPE_SFIXED64:
+		if i, err := strconv.ParseInt(val, 10, 64); err == nil {
+			return i
+		} else {
+			return int64(0)
+		}
+	case dpb.FieldDescriptorProto_TYPE_UINT64,
+		dpb.FieldDescriptorProto_TYPE_FIXED64:
+		if i, err := strconv.ParseUint(val, 10, 64); err == nil {
+			return i
+		} else {
+			return uint64(0)
+		}
+	default:
+		return nil
+	}
+}
+
+func unescape(s string) string {
+	// protoc encodes default values for 'bytes' fields using C escaping,
+	// so this function reverses that escaping
+	out := make([]byte, 0, len(s))
+	var buf [4]byte
+	for len(s) > 0 {
+		if s[0] != '\\' || len(s) < 2 {
+			// not escape sequence, or too short to be well-formed escape
+			out = append(out, s[0])
+			s = s[1:]
+		} else if s[1] == 'x' || s[1] == 'X' {
+			n := matchPrefix(s[2:], 2, isHex)
+			if n == 0 {
+				// bad escape
+				out = append(out, s[:2]...)
+				s = s[2:]
+			} else {
+				c, err := strconv.ParseUint(s[2:2+n], 16, 8)
+				if err != nil {
+					// shouldn't really happen...
+					out = append(out, s[:2+n]...)
+				} else {
+					out = append(out, byte(c))
+				}
+				s = s[2+n:]
+			}
+		} else if s[1] >= '0' && s[1] <= '7' {
+			n := 1 + matchPrefix(s[2:], 2, isOctal)
+			c, err := strconv.ParseUint(s[1:1+n], 8, 8)
+			if err != nil || c > 0xff {
+				out = append(out, s[:1+n]...)
+			} else {
+				out = append(out, byte(c))
+			}
+			s = s[1+n:]
+		} else if s[1] == 'u' {
+			if len(s) < 6 {
+				// bad escape
+				out = append(out, s...)
+				s = s[len(s):]
+			} else {
+				c, err := strconv.ParseUint(s[2:6], 16, 16)
+				if err != nil {
+					// bad escape
+					out = append(out, s[:6]...)
+				} else {
+					w := utf8.EncodeRune(buf[:], rune(c))
+					out = append(out, buf[:w]...)
+				}
+				s = s[6:]
+			}
+		} else if s[1] == 'U' {
+			if len(s) < 10 {
+				// bad escape
+				out = append(out, s...)
+				s = s[len(s):]
+			} else {
+				c, err := strconv.ParseUint(s[2:10], 16, 32)
+				if err != nil || c > 0x10ffff {
+					// bad escape
+					out = append(out, s[:10]...)
+				} else {
+					w := utf8.EncodeRune(buf[:], rune(c))
+					out = append(out, buf[:w]...)
+				}
+				s = s[10:]
+			}
+		} else {
+			switch s[1] {
+			case 'a':
+				out = append(out, '\a')
+			case 'b':
+				out = append(out, '\b')
+			case 'f':
+				out = append(out, '\f')
+			case 'n':
+				out = append(out, '\n')
+			case 'r':
+				out = append(out, '\r')
+			case 't':
+				out = append(out, '\t')
+			case 'v':
+				out = append(out, '\v')
+			case '\\':
+				out = append(out, '\\')
+			case '\'':
+				out = append(out, '\'')
+			case '"':
+				out = append(out, '"')
+			case '?':
+				out = append(out, '?')
+			default:
+				// invalid escape, just copy it as-is
+				out = append(out, s[:2]...)
+			}
+			s = s[2:]
+		}
+	}
+	return string(out)
+}
+
+func isOctal(b byte) bool { return b >= '0' && b <= '7' }
+func isHex(b byte) bool {
+	return (b >= '0' && b <= '9') || (b >= 'a' && b <= 'f') || (b >= 'A' && b <= 'F')
+}
+func matchPrefix(s string, limit int, fn func(byte) bool) int {
+	l := len(s)
+	if l > limit {
+		l = limit
+	}
+	i := 0
+	for ; i < l; i++ {
+		if !fn(s[i]) {
+			return i
+		}
+	}
+	return i
+}
+
+// GetName returns the name of the field.
+func (fd *FieldDescriptor) GetName() string {
+	return fd.proto.GetName()
+}
+
+// GetNumber returns the tag number of this field.
+func (fd *FieldDescriptor) GetNumber() int32 {
+	return fd.proto.GetNumber()
+}
+
+// GetFullyQualifiedName returns the fully qualified name of the field. Unlike
+// GetName, this includes fully qualified name of the enclosing message for
+// regular fields.
+//
+// For extension fields, this includes the package (if there is one) as well as
+// any enclosing messages. The package and/or enclosing messages are for where
+// the extension is defined, not the message it extends.
+//
+// If this field is part of a one-of, the fully qualified name does *not*
+// include the name of the one-of, only of the enclosing message.
+func (fd *FieldDescriptor) GetFullyQualifiedName() string {
+	return fd.fqn
+}
+
+// GetParent returns the fields's enclosing descriptor. For normal
+// (non-extension) fields, this is the enclosing message. For extensions, this
+// is the descriptor in which the extension is defined, not the message that is
+// extended. The parent for an extension may be a file descriptor or a message,
+// depending on where the extension is defined.
+func (fd *FieldDescriptor) GetParent() Descriptor {
+	return fd.parent
+}
+
+// GetFile returns the descriptor for the file in which this field is defined.
+func (fd *FieldDescriptor) GetFile() *FileDescriptor {
+	return fd.file
+}
+
+// GetOptions returns the field's options. Most usages will be more interested
+// in GetFieldOptions, which has a concrete return type. This generic version
+// is present to satisfy the Descriptor interface.
+func (fd *FieldDescriptor) GetOptions() proto.Message {
+	return fd.proto.GetOptions()
+}
+
+// GetFieldOptions returns the field's options.
+func (fd *FieldDescriptor) GetFieldOptions() *dpb.FieldOptions {
+	return fd.proto.GetOptions()
+}
+
+// GetSourceInfo returns source info for the field, if present in the
+// descriptor. Not all descriptors will contain source info. If non-nil, the
+// returned info contains information about the location in the file where the
+// field was defined and also contains comments associated with the field
+// definition.
+func (fd *FieldDescriptor) GetSourceInfo() *dpb.SourceCodeInfo_Location {
+	return fd.file.sourceInfo.Get(fd.sourceInfoPath)
+}
+
+// AsProto returns the underlying descriptor proto. Most usages will be more
+// interested in AsFieldDescriptorProto, which has a concrete return type. This
+// generic version is present to satisfy the Descriptor interface.
+func (fd *FieldDescriptor) AsProto() proto.Message {
+	return fd.proto
+}
+
+// AsFieldDescriptorProto returns the underlying descriptor proto.
+func (fd *FieldDescriptor) AsFieldDescriptorProto() *dpb.FieldDescriptorProto {
+	return fd.proto
+}
+
+// String returns the underlying descriptor proto, in compact text format.
+func (fd *FieldDescriptor) String() string {
+	return fd.proto.String()
+}
+
+// GetJSONName returns the name of the field as referenced in the message's JSON
+// format.
+func (fd *FieldDescriptor) GetJSONName() string {
+	if jsonName := fd.proto.JsonName; jsonName != nil {
+		// if json name is present, use its value
+		return *jsonName
+	}
+	// otherwise, compute the proper JSON name from the field name
+	return jsonCamelCase(fd.proto.GetName())
+}
+
+func jsonCamelCase(s string) string {
+	// This mirrors the implementation in protoc/C++ runtime and in the Java runtime:
+	//   https://github.com/protocolbuffers/protobuf/blob/a104dffcb6b1958a424f5fa6f9e6bdc0ab9b6f9e/src/google/protobuf/descriptor.cc#L276
+	//   https://github.com/protocolbuffers/protobuf/blob/a1c886834425abb64a966231dd2c9dd84fb289b3/java/core/src/main/java/com/google/protobuf/Descriptors.java#L1286
+	var buf bytes.Buffer
+	prevWasUnderscore := false
+	for _, r := range s {
+		if r == '_' {
+			prevWasUnderscore = true
+			continue
+		}
+		if prevWasUnderscore {
+			r = unicode.ToUpper(r)
+			prevWasUnderscore = false
+		}
+		buf.WriteRune(r)
+	}
+	return buf.String()
+}
+
+// GetFullyQualifiedJSONName returns the JSON format name (same as GetJSONName),
+// but includes the fully qualified name of the enclosing message.
+//
+// If the field is an extension, it will return the package name (if there is
+// one) as well as the names of any enclosing messages. The package and/or
+// enclosing messages are for where the extension is defined, not the message it
+// extends.
+func (fd *FieldDescriptor) GetFullyQualifiedJSONName() string {
+	parent := fd.GetParent()
+	switch parent := parent.(type) {
+	case *FileDescriptor:
+		pkg := parent.GetPackage()
+		if pkg == "" {
+			return fd.GetJSONName()
+		}
+		return fmt.Sprintf("%s.%s", pkg, fd.GetJSONName())
+	default:
+		return fmt.Sprintf("%s.%s", parent.GetFullyQualifiedName(), fd.GetJSONName())
+	}
+}
+
+// GetOwner returns the message type that this field belongs to. If this is a normal
+// field then this is the same as GetParent. But for extensions, this will be the
+// extendee message whereas GetParent refers to where the extension was declared.
+func (fd *FieldDescriptor) GetOwner() *MessageDescriptor {
+	return fd.owner
+}
+
+// IsExtension returns true if this is an extension field.
+func (fd *FieldDescriptor) IsExtension() bool {
+	return fd.proto.GetExtendee() != ""
+}
+
+// GetOneOf returns the one-of field set to which this field belongs. If this field
+// is not part of a one-of then this method returns nil.
+func (fd *FieldDescriptor) GetOneOf() *OneOfDescriptor {
+	return fd.oneOf
+}
+
+// GetType returns the type of this field. If the type indicates an enum, the
+// enum type can be queried via GetEnumType. If the type indicates a message, the
+// message type can be queried via GetMessageType.
+func (fd *FieldDescriptor) GetType() dpb.FieldDescriptorProto_Type {
+	return fd.proto.GetType()
+}
+
+// GetLabel returns the label for this field. The label can be required (proto2-only),
+// optional (default for proto3), or required.
+func (fd *FieldDescriptor) GetLabel() dpb.FieldDescriptorProto_Label {
+	return fd.proto.GetLabel()
+}
+
+// IsRequired returns true if this field has the "required" label.
+func (fd *FieldDescriptor) IsRequired() bool {
+	return fd.proto.GetLabel() == dpb.FieldDescriptorProto_LABEL_REQUIRED
+}
+
+// IsRepeated returns true if this field has the "repeated" label.
+func (fd *FieldDescriptor) IsRepeated() bool {
+	return fd.proto.GetLabel() == dpb.FieldDescriptorProto_LABEL_REPEATED
+}
+
+// IsProto3Optional returns true if this field has an explicit "optional" label
+// and is in a "proto3" syntax file. Such fields, if they are normal fields (not
+// extensions), will be nested in synthetic oneofs that contain only the single
+// field.
+func (fd *FieldDescriptor) IsProto3Optional() bool {
+	return internal.GetProto3Optional(fd.proto)
+}
+
+// HasPresence returns true if this field can distinguish when a value is
+// present or not. Scalar fields in "proto3" syntax files, for example, return
+// false since absent values are indistinguishable from zero values.
+func (fd *FieldDescriptor) HasPresence() bool {
+	if !fd.file.isProto3 {
+		return true
+	}
+	return fd.msgType != nil || fd.oneOf != nil
+}
+
+// IsMap returns true if this is a map field. If so, it will have the "repeated"
+// label its type will be a message that represents a map entry. The map entry
+// message will have exactly two fields: tag #1 is the key and tag #2 is the value.
+func (fd *FieldDescriptor) IsMap() bool {
+	return fd.isMap
+}
+
+// GetMapKeyType returns the type of the key field if this is a map field. If it is
+// not a map field, nil is returned.
+func (fd *FieldDescriptor) GetMapKeyType() *FieldDescriptor {
+	if fd.isMap {
+		return fd.msgType.FindFieldByNumber(int32(1))
+	}
+	return nil
+}
+
+// GetMapValueType returns the type of the value field if this is a map field. If it
+// is not a map field, nil is returned.
+func (fd *FieldDescriptor) GetMapValueType() *FieldDescriptor {
+	if fd.isMap {
+		return fd.msgType.FindFieldByNumber(int32(2))
+	}
+	return nil
+}
+
+// GetMessageType returns the type of this field if it is a message type. If
+// this field is not a message type, it returns nil.
+func (fd *FieldDescriptor) GetMessageType() *MessageDescriptor {
+	return fd.msgType
+}
+
+// GetEnumType returns the type of this field if it is an enum type. If this
+// field is not an enum type, it returns nil.
+func (fd *FieldDescriptor) GetEnumType() *EnumDescriptor {
+	return fd.enumType
+}
+
+// GetDefaultValue returns the default value for this field.
+//
+// If this field represents a message type, this method always returns nil (even though
+// for proto2 files, the default value should be a default instance of the message type).
+// If the field represents an enum type, this method returns an int32 corresponding to the
+// enum value. If this field is a map, it returns a nil map[interface{}]interface{}. If
+// this field is repeated (and not a map), it returns a nil []interface{}.
+//
+// Otherwise, it returns the declared default value for the field or a zero value, if no
+// default is declared or if the file is proto3. The type of said return value corresponds
+// to the type of the field:
+//  +-------------------------+-----------+
+//  |       Declared Type     |  Go Type  |
+//  +-------------------------+-----------+
+//  | int32, sint32, sfixed32 | int32     |
+//  | int64, sint64, sfixed64 | int64     |
+//  | uint32, fixed32         | uint32    |
+//  | uint64, fixed64         | uint64    |
+//  | float                   | float32   |
+//  | double                  | double32  |
+//  | bool                    | bool      |
+//  | string                  | string    |
+//  | bytes                   | []byte    |
+//  +-------------------------+-----------+
+func (fd *FieldDescriptor) GetDefaultValue() interface{} {
+	return fd.getDefaultValue()
+}
+
+// EnumDescriptor describes an enum declared in a proto file.
+type EnumDescriptor struct {
+	proto          *dpb.EnumDescriptorProto
+	parent         Descriptor
+	file           *FileDescriptor
+	values         []*EnumValueDescriptor
+	valuesByNum    sortedValues
+	fqn            string
+	sourceInfoPath []int32
+}
+
+func createEnumDescriptor(fd *FileDescriptor, parent Descriptor, enclosing string, ed *dpb.EnumDescriptorProto, symbols map[string]Descriptor) (*EnumDescriptor, string) {
+	enumName := merge(enclosing, ed.GetName())
+	ret := &EnumDescriptor{proto: ed, parent: parent, file: fd, fqn: enumName}
+	for _, ev := range ed.GetValue() {
+		evd, n := createEnumValueDescriptor(fd, ret, enumName, ev)
+		symbols[n] = evd
+		ret.values = append(ret.values, evd)
+	}
+	if len(ret.values) > 0 {
+		ret.valuesByNum = make(sortedValues, len(ret.values))
+		copy(ret.valuesByNum, ret.values)
+		sort.Stable(ret.valuesByNum)
+	}
+	return ret, enumName
+}
+
+type sortedValues []*EnumValueDescriptor
+
+func (sv sortedValues) Len() int {
+	return len(sv)
+}
+
+func (sv sortedValues) Less(i, j int) bool {
+	return sv[i].GetNumber() < sv[j].GetNumber()
+}
+
+func (sv sortedValues) Swap(i, j int) {
+	sv[i], sv[j] = sv[j], sv[i]
+}
+
+func (ed *EnumDescriptor) resolve(path []int32) {
+	ed.sourceInfoPath = append([]int32(nil), path...) // defensive copy
+	path = append(path, internal.Enum_valuesTag)
+	for i, evd := range ed.values {
+		evd.resolve(append(path, int32(i)))
+	}
+}
+
+// GetName returns the simple (unqualified) name of the enum type.
+func (ed *EnumDescriptor) GetName() string {
+	return ed.proto.GetName()
+}
+
+// GetFullyQualifiedName returns the fully qualified name of the enum type.
+// This includes the package name (if there is one) as well as the names of any
+// enclosing messages.
+func (ed *EnumDescriptor) GetFullyQualifiedName() string {
+	return ed.fqn
+}
+
+// GetParent returns the enum type's enclosing descriptor. For top-level enums,
+// this will be a file descriptor. Otherwise it will be the descriptor for the
+// enclosing message.
+func (ed *EnumDescriptor) GetParent() Descriptor {
+	return ed.parent
+}
+
+// GetFile returns the descriptor for the file in which this enum is defined.
+func (ed *EnumDescriptor) GetFile() *FileDescriptor {
+	return ed.file
+}
+
+// GetOptions returns the enum type's options. Most usages will be more
+// interested in GetEnumOptions, which has a concrete return type. This generic
+// version is present to satisfy the Descriptor interface.
+func (ed *EnumDescriptor) GetOptions() proto.Message {
+	return ed.proto.GetOptions()
+}
+
+// GetEnumOptions returns the enum type's options.
+func (ed *EnumDescriptor) GetEnumOptions() *dpb.EnumOptions {
+	return ed.proto.GetOptions()
+}
+
+// GetSourceInfo returns source info for the enum type, if present in the
+// descriptor. Not all descriptors will contain source info. If non-nil, the
+// returned info contains information about the location in the file where the
+// enum type was defined and also contains comments associated with the enum
+// definition.
+func (ed *EnumDescriptor) GetSourceInfo() *dpb.SourceCodeInfo_Location {
+	return ed.file.sourceInfo.Get(ed.sourceInfoPath)
+}
+
+// AsProto returns the underlying descriptor proto. Most usages will be more
+// interested in AsEnumDescriptorProto, which has a concrete return type. This
+// generic version is present to satisfy the Descriptor interface.
+func (ed *EnumDescriptor) AsProto() proto.Message {
+	return ed.proto
+}
+
+// AsEnumDescriptorProto returns the underlying descriptor proto.
+func (ed *EnumDescriptor) AsEnumDescriptorProto() *dpb.EnumDescriptorProto {
+	return ed.proto
+}
+
+// String returns the underlying descriptor proto, in compact text format.
+func (ed *EnumDescriptor) String() string {
+	return ed.proto.String()
+}
+
+// GetValues returns all of the allowed values defined for this enum.
+func (ed *EnumDescriptor) GetValues() []*EnumValueDescriptor {
+	return ed.values
+}
+
+// FindValueByName finds the enum value with the given name. If no such value exists
+// then nil is returned.
+func (ed *EnumDescriptor) FindValueByName(name string) *EnumValueDescriptor {
+	fqn := fmt.Sprintf("%s.%s", ed.fqn, name)
+	if vd, ok := ed.file.symbols[fqn].(*EnumValueDescriptor); ok {
+		return vd
+	} else {
+		return nil
+	}
+}
+
+// FindValueByNumber finds the value with the given numeric value. If no such value
+// exists then nil is returned. If aliases are allowed and multiple values have the
+// given number, the first declared value is returned.
+func (ed *EnumDescriptor) FindValueByNumber(num int32) *EnumValueDescriptor {
+	index := sort.Search(len(ed.valuesByNum), func(i int) bool { return ed.valuesByNum[i].GetNumber() >= num })
+	if index < len(ed.valuesByNum) {
+		vd := ed.valuesByNum[index]
+		if vd.GetNumber() == num {
+			return vd
+		}
+	}
+	return nil
+}
+
+// EnumValueDescriptor describes an allowed value of an enum declared in a proto file.
+type EnumValueDescriptor struct {
+	proto          *dpb.EnumValueDescriptorProto
+	parent         *EnumDescriptor
+	file           *FileDescriptor
+	fqn            string
+	sourceInfoPath []int32
+}
+
+func createEnumValueDescriptor(fd *FileDescriptor, parent *EnumDescriptor, enclosing string, evd *dpb.EnumValueDescriptorProto) (*EnumValueDescriptor, string) {
+	valName := merge(enclosing, evd.GetName())
+	return &EnumValueDescriptor{proto: evd, parent: parent, file: fd, fqn: valName}, valName
+}
+
+func (vd *EnumValueDescriptor) resolve(path []int32) {
+	vd.sourceInfoPath = append([]int32(nil), path...) // defensive copy
+}
+
+// GetName returns the name of the enum value.
+func (vd *EnumValueDescriptor) GetName() string {
+	return vd.proto.GetName()
+}
+
+// GetNumber returns the numeric value associated with this enum value.
+func (vd *EnumValueDescriptor) GetNumber() int32 {
+	return vd.proto.GetNumber()
+}
+
+// GetFullyQualifiedName returns the fully qualified name of the enum value.
+// Unlike GetName, this includes fully qualified name of the enclosing enum.
+func (vd *EnumValueDescriptor) GetFullyQualifiedName() string {
+	return vd.fqn
+}
+
+// GetParent returns the descriptor for the enum in which this enum value is
+// defined. Most usages will prefer to use GetEnum, which has a concrete return
+// type. This more generic method is present to satisfy the Descriptor interface.
+func (vd *EnumValueDescriptor) GetParent() Descriptor {
+	return vd.parent
+}
+
+// GetEnum returns the enum in which this enum value is defined.
+func (vd *EnumValueDescriptor) GetEnum() *EnumDescriptor {
+	return vd.parent
+}
+
+// GetFile returns the descriptor for the file in which this enum value is
+// defined.
+func (vd *EnumValueDescriptor) GetFile() *FileDescriptor {
+	return vd.file
+}
+
+// GetOptions returns the enum value's options. Most usages will be more
+// interested in GetEnumValueOptions, which has a concrete return type. This
+// generic version is present to satisfy the Descriptor interface.
+func (vd *EnumValueDescriptor) GetOptions() proto.Message {
+	return vd.proto.GetOptions()
+}
+
+// GetEnumValueOptions returns the enum value's options.
+func (vd *EnumValueDescriptor) GetEnumValueOptions() *dpb.EnumValueOptions {
+	return vd.proto.GetOptions()
+}
+
+// GetSourceInfo returns source info for the enum value, if present in the
+// descriptor. Not all descriptors will contain source info. If non-nil, the
+// returned info contains information about the location in the file where the
+// enum value was defined and also contains comments associated with the enum
+// value definition.
+func (vd *EnumValueDescriptor) GetSourceInfo() *dpb.SourceCodeInfo_Location {
+	return vd.file.sourceInfo.Get(vd.sourceInfoPath)
+}
+
+// AsProto returns the underlying descriptor proto. Most usages will be more
+// interested in AsEnumValueDescriptorProto, which has a concrete return type.
+// This generic version is present to satisfy the Descriptor interface.
+func (vd *EnumValueDescriptor) AsProto() proto.Message {
+	return vd.proto
+}
+
+// AsEnumValueDescriptorProto returns the underlying descriptor proto.
+func (vd *EnumValueDescriptor) AsEnumValueDescriptorProto() *dpb.EnumValueDescriptorProto {
+	return vd.proto
+}
+
+// String returns the underlying descriptor proto, in compact text format.
+func (vd *EnumValueDescriptor) String() string {
+	return vd.proto.String()
+}
+
+// ServiceDescriptor describes an RPC service declared in a proto file.
+type ServiceDescriptor struct {
+	proto          *dpb.ServiceDescriptorProto
+	file           *FileDescriptor
+	methods        []*MethodDescriptor
+	fqn            string
+	sourceInfoPath []int32
+}
+
+func createServiceDescriptor(fd *FileDescriptor, enclosing string, sd *dpb.ServiceDescriptorProto, symbols map[string]Descriptor) (*ServiceDescriptor, string) {
+	serviceName := merge(enclosing, sd.GetName())
+	ret := &ServiceDescriptor{proto: sd, file: fd, fqn: serviceName}
+	for _, m := range sd.GetMethod() {
+		md, n := createMethodDescriptor(fd, ret, serviceName, m)
+		symbols[n] = md
+		ret.methods = append(ret.methods, md)
+	}
+	return ret, serviceName
+}
+
+func (sd *ServiceDescriptor) resolve(path []int32, scopes []scope) error {
+	sd.sourceInfoPath = append([]int32(nil), path...) // defensive copy
+	path = append(path, internal.Service_methodsTag)
+	for i, md := range sd.methods {
+		if err := md.resolve(append(path, int32(i)), scopes); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// GetName returns the simple (unqualified) name of the service.
+func (sd *ServiceDescriptor) GetName() string {
+	return sd.proto.GetName()
+}
+
+// GetFullyQualifiedName returns the fully qualified name of the service. This
+// includes the package name (if there is one).
+func (sd *ServiceDescriptor) GetFullyQualifiedName() string {
+	return sd.fqn
+}
+
+// GetParent returns the descriptor for the file in which this service is
+// defined. Most usages will prefer to use GetFile, which has a concrete return
+// type. This more generic method is present to satisfy the Descriptor interface.
+func (sd *ServiceDescriptor) GetParent() Descriptor {
+	return sd.file
+}
+
+// GetFile returns the descriptor for the file in which this service is defined.
+func (sd *ServiceDescriptor) GetFile() *FileDescriptor {
+	return sd.file
+}
+
+// GetOptions returns the service's options. Most usages will be more interested
+// in GetServiceOptions, which has a concrete return type. This generic version
+// is present to satisfy the Descriptor interface.
+func (sd *ServiceDescriptor) GetOptions() proto.Message {
+	return sd.proto.GetOptions()
+}
+
+// GetServiceOptions returns the service's options.
+func (sd *ServiceDescriptor) GetServiceOptions() *dpb.ServiceOptions {
+	return sd.proto.GetOptions()
+}
+
+// GetSourceInfo returns source info for the service, if present in the
+// descriptor. Not all descriptors will contain source info. If non-nil, the
+// returned info contains information about the location in the file where the
+// service was defined and also contains comments associated with the service
+// definition.
+func (sd *ServiceDescriptor) GetSourceInfo() *dpb.SourceCodeInfo_Location {
+	return sd.file.sourceInfo.Get(sd.sourceInfoPath)
+}
+
+// AsProto returns the underlying descriptor proto. Most usages will be more
+// interested in AsServiceDescriptorProto, which has a concrete return type.
+// This generic version is present to satisfy the Descriptor interface.
+func (sd *ServiceDescriptor) AsProto() proto.Message {
+	return sd.proto
+}
+
+// AsServiceDescriptorProto returns the underlying descriptor proto.
+func (sd *ServiceDescriptor) AsServiceDescriptorProto() *dpb.ServiceDescriptorProto {
+	return sd.proto
+}
+
+// String returns the underlying descriptor proto, in compact text format.
+func (sd *ServiceDescriptor) String() string {
+	return sd.proto.String()
+}
+
+// GetMethods returns all of the RPC methods for this service.
+func (sd *ServiceDescriptor) GetMethods() []*MethodDescriptor {
+	return sd.methods
+}
+
+// FindMethodByName finds the method with the given name. If no such method exists
+// then nil is returned.
+func (sd *ServiceDescriptor) FindMethodByName(name string) *MethodDescriptor {
+	fqn := fmt.Sprintf("%s.%s", sd.fqn, name)
+	if md, ok := sd.file.symbols[fqn].(*MethodDescriptor); ok {
+		return md
+	} else {
+		return nil
+	}
+}
+
+// MethodDescriptor describes an RPC method declared in a proto file.
+type MethodDescriptor struct {
+	proto          *dpb.MethodDescriptorProto
+	parent         *ServiceDescriptor
+	file           *FileDescriptor
+	inType         *MessageDescriptor
+	outType        *MessageDescriptor
+	fqn            string
+	sourceInfoPath []int32
+}
+
+func createMethodDescriptor(fd *FileDescriptor, parent *ServiceDescriptor, enclosing string, md *dpb.MethodDescriptorProto) (*MethodDescriptor, string) {
+	// request and response types get resolved later
+	methodName := merge(enclosing, md.GetName())
+	return &MethodDescriptor{proto: md, parent: parent, file: fd, fqn: methodName}, methodName
+}
+
+func (md *MethodDescriptor) resolve(path []int32, scopes []scope) error {
+	md.sourceInfoPath = append([]int32(nil), path...) // defensive copy
+	if desc, err := resolve(md.file, md.proto.GetInputType(), scopes); err != nil {
+		return err
+	} else {
+		md.inType = desc.(*MessageDescriptor)
+	}
+	if desc, err := resolve(md.file, md.proto.GetOutputType(), scopes); err != nil {
+		return err
+	} else {
+		md.outType = desc.(*MessageDescriptor)
+	}
+	return nil
+}
+
+// GetName returns the name of the method.
+func (md *MethodDescriptor) GetName() string {
+	return md.proto.GetName()
+}
+
+// GetFullyQualifiedName returns the fully qualified name of the method. Unlike
+// GetName, this includes fully qualified name of the enclosing service.
+func (md *MethodDescriptor) GetFullyQualifiedName() string {
+	return md.fqn
+}
+
+// GetParent returns the descriptor for the service in which this method is
+// defined. Most usages will prefer to use GetService, which has a concrete
+// return type. This more generic method is present to satisfy the Descriptor
+// interface.
+func (md *MethodDescriptor) GetParent() Descriptor {
+	return md.parent
+}
+
+// GetService returns the RPC service in which this method is declared.
+func (md *MethodDescriptor) GetService() *ServiceDescriptor {
+	return md.parent
+}
+
+// GetFile returns the descriptor for the file in which this method is defined.
+func (md *MethodDescriptor) GetFile() *FileDescriptor {
+	return md.file
+}
+
+// GetOptions returns the method's options. Most usages will be more interested
+// in GetMethodOptions, which has a concrete return type. This generic version
+// is present to satisfy the Descriptor interface.
+func (md *MethodDescriptor) GetOptions() proto.Message {
+	return md.proto.GetOptions()
+}
+
+// GetMethodOptions returns the method's options.
+func (md *MethodDescriptor) GetMethodOptions() *dpb.MethodOptions {
+	return md.proto.GetOptions()
+}
+
+// GetSourceInfo returns source info for the method, if present in the
+// descriptor. Not all descriptors will contain source info. If non-nil, the
+// returned info contains information about the location in the file where the
+// method was defined and also contains comments associated with the method
+// definition.
+func (md *MethodDescriptor) GetSourceInfo() *dpb.SourceCodeInfo_Location {
+	return md.file.sourceInfo.Get(md.sourceInfoPath)
+}
+
+// AsProto returns the underlying descriptor proto. Most usages will be more
+// interested in AsMethodDescriptorProto, which has a concrete return type. This
+// generic version is present to satisfy the Descriptor interface.
+func (md *MethodDescriptor) AsProto() proto.Message {
+	return md.proto
+}
+
+// AsMethodDescriptorProto returns the underlying descriptor proto.
+func (md *MethodDescriptor) AsMethodDescriptorProto() *dpb.MethodDescriptorProto {
+	return md.proto
+}
+
+// String returns the underlying descriptor proto, in compact text format.
+func (md *MethodDescriptor) String() string {
+	return md.proto.String()
+}
+
+// IsServerStreaming returns true if this is a server-streaming method.
+func (md *MethodDescriptor) IsServerStreaming() bool {
+	return md.proto.GetServerStreaming()
+}
+
+// IsClientStreaming returns true if this is a client-streaming method.
+func (md *MethodDescriptor) IsClientStreaming() bool {
+	return md.proto.GetClientStreaming()
+}
+
+// GetInputType returns the input type, or request type, of the RPC method.
+func (md *MethodDescriptor) GetInputType() *MessageDescriptor {
+	return md.inType
+}
+
+// GetOutputType returns the output type, or response type, of the RPC method.
+func (md *MethodDescriptor) GetOutputType() *MessageDescriptor {
+	return md.outType
+}
+
+// OneOfDescriptor describes a one-of field set declared in a protocol buffer message.
+type OneOfDescriptor struct {
+	proto          *dpb.OneofDescriptorProto
+	parent         *MessageDescriptor
+	file           *FileDescriptor
+	choices        []*FieldDescriptor
+	fqn            string
+	sourceInfoPath []int32
+}
+
+func createOneOfDescriptor(fd *FileDescriptor, parent *MessageDescriptor, index int, enclosing string, od *dpb.OneofDescriptorProto) (*OneOfDescriptor, string) {
+	oneOfName := merge(enclosing, od.GetName())
+	ret := &OneOfDescriptor{proto: od, parent: parent, file: fd, fqn: oneOfName}
+	for _, f := range parent.fields {
+		oi := f.proto.OneofIndex
+		if oi != nil && *oi == int32(index) {
+			f.oneOf = ret
+			ret.choices = append(ret.choices, f)
+		}
+	}
+	return ret, oneOfName
+}
+
+func (od *OneOfDescriptor) resolve(path []int32) {
+	od.sourceInfoPath = append([]int32(nil), path...) // defensive copy
+}
+
+// GetName returns the name of the one-of.
+func (od *OneOfDescriptor) GetName() string {
+	return od.proto.GetName()
+}
+
+// GetFullyQualifiedName returns the fully qualified name of the one-of. Unlike
+// GetName, this includes fully qualified name of the enclosing message.
+func (od *OneOfDescriptor) GetFullyQualifiedName() string {
+	return od.fqn
+}
+
+// GetParent returns the descriptor for the message in which this one-of is
+// defined. Most usages will prefer to use GetOwner, which has a concrete
+// return type. This more generic method is present to satisfy the Descriptor
+// interface.
+func (od *OneOfDescriptor) GetParent() Descriptor {
+	return od.parent
+}
+
+// GetOwner returns the message to which this one-of field set belongs.
+func (od *OneOfDescriptor) GetOwner() *MessageDescriptor {
+	return od.parent
+}
+
+// GetFile returns the descriptor for the file in which this one-fof is defined.
+func (od *OneOfDescriptor) GetFile() *FileDescriptor {
+	return od.file
+}
+
+// GetOptions returns the one-of's options. Most usages will be more interested
+// in GetOneOfOptions, which has a concrete return type. This generic version
+// is present to satisfy the Descriptor interface.
+func (od *OneOfDescriptor) GetOptions() proto.Message {
+	return od.proto.GetOptions()
+}
+
+// GetOneOfOptions returns the one-of's options.
+func (od *OneOfDescriptor) GetOneOfOptions() *dpb.OneofOptions {
+	return od.proto.GetOptions()
+}
+
+// GetSourceInfo returns source info for the one-of, if present in the
+// descriptor. Not all descriptors will contain source info. If non-nil, the
+// returned info contains information about the location in the file where the
+// one-of was defined and also contains comments associated with the one-of
+// definition.
+func (od *OneOfDescriptor) GetSourceInfo() *dpb.SourceCodeInfo_Location {
+	return od.file.sourceInfo.Get(od.sourceInfoPath)
+}
+
+// AsProto returns the underlying descriptor proto. Most usages will be more
+// interested in AsOneofDescriptorProto, which has a concrete return type. This
+// generic version is present to satisfy the Descriptor interface.
+func (od *OneOfDescriptor) AsProto() proto.Message {
+	return od.proto
+}
+
+// AsOneofDescriptorProto returns the underlying descriptor proto.
+func (od *OneOfDescriptor) AsOneofDescriptorProto() *dpb.OneofDescriptorProto {
+	return od.proto
+}
+
+// String returns the underlying descriptor proto, in compact text format.
+func (od *OneOfDescriptor) String() string {
+	return od.proto.String()
+}
+
+// GetChoices returns the fields that are part of the one-of field set. At most one of
+// these fields may be set for a given message.
+func (od *OneOfDescriptor) GetChoices() []*FieldDescriptor {
+	return od.choices
+}
+
+func (od *OneOfDescriptor) IsSynthetic() bool {
+	return len(od.choices) == 1 && od.choices[0].IsProto3Optional()
+}
+
+// scope represents a lexical scope in a proto file in which messages and enums
+// can be declared.
+type scope func(string) Descriptor
+
+func fileScope(fd *FileDescriptor) scope {
+	// we search symbols in this file, but also symbols in other files that have
+	// the same package as this file or a "parent" package (in protobuf,
+	// packages are a hierarchy like C++ namespaces)
+	prefixes := internal.CreatePrefixList(fd.proto.GetPackage())
+	return func(name string) Descriptor {
+		for _, prefix := range prefixes {
+			n := merge(prefix, name)
+			d := findSymbol(fd, n, false)
+			if d != nil {
+				return d
+			}
+		}
+		return nil
+	}
+}
+
+func messageScope(md *MessageDescriptor) scope {
+	return func(name string) Descriptor {
+		n := merge(md.fqn, name)
+		if d, ok := md.file.symbols[n]; ok {
+			return d
+		}
+		return nil
+	}
+}
+
+func resolve(fd *FileDescriptor, name string, scopes []scope) (Descriptor, error) {
+	if strings.HasPrefix(name, ".") {
+		// already fully-qualified
+		d := findSymbol(fd, name[1:], false)
+		if d != nil {
+			return d, nil
+		}
+	} else {
+		// unqualified, so we look in the enclosing (last) scope first and move
+		// towards outermost (first) scope, trying to resolve the symbol
+		for i := len(scopes) - 1; i >= 0; i-- {
+			d := scopes[i](name)
+			if d != nil {
+				return d, nil
+			}
+		}
+	}
+	return nil, fmt.Errorf("file %q included an unresolvable reference to %q", fd.proto.GetName(), name)
+}
+
+func findSymbol(fd *FileDescriptor, name string, public bool) Descriptor {
+	d := fd.symbols[name]
+	if d != nil {
+		return d
+	}
+
+	// When public = false, we are searching only directly imported symbols. But we
+	// also need to search transitive public imports due to semantics of public imports.
+	var deps []*FileDescriptor
+	if public {
+		deps = fd.publicDeps
+	} else {
+		deps = fd.deps
+	}
+	for _, dep := range deps {
+		d = findSymbol(dep, name, true)
+		if d != nil {
+			return d
+		}
+	}
+
+	return nil
+}
+
+func merge(a, b string) string {
+	if a == "" {
+		return b
+	} else {
+		return a + "." + b
+	}
+}