diff --git a/vendor/github.com/jhump/protoreflect/codec/codec.go b/vendor/github.com/jhump/protoreflect/codec/codec.go
new file mode 100644
index 0000000..b6f4ed0
--- /dev/null
+++ b/vendor/github.com/jhump/protoreflect/codec/codec.go
@@ -0,0 +1,217 @@
+package codec
+
+import (
+	"io"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/jhump/protoreflect/internal/codec"
+)
+
+// ErrOverflow is returned when an integer is too large to be represented.
+var ErrOverflow = codec.ErrOverflow
+
+// ErrBadWireType is returned when decoding a wire-type from a buffer that
+// is not valid.
+var ErrBadWireType = codec.ErrBadWireType
+
+// NB: much of the implementation is in an internal package, to avoid an import
+// cycle between this codec package and the desc package. We export it from
+// this package, but we can't use a type alias because we also need to add
+// methods to it, to broaden the exposed API.
+
+// Buffer is a reader and a writer that wraps a slice of bytes and also
+// provides API for decoding and encoding the protobuf binary format.
+//
+// Its operation is similar to that of a bytes.Buffer: writing pushes
+// data to the end of the buffer while reading pops data from the head
+// of the buffer. So the same buffer can be used to both read and write.
+type Buffer codec.Buffer
+
+// NewBuffer creates a new buffer with the given slice of bytes as the
+// buffer's initial contents.
+func NewBuffer(buf []byte) *Buffer {
+	return (*Buffer)(codec.NewBuffer(buf))
+}
+
+// SetDeterministic sets this buffer to encode messages deterministically. This
+// is useful for tests. But the overhead is non-zero, so it should not likely be
+// used outside of tests. When true, map fields in a message must have their
+// keys sorted before serialization to ensure deterministic output. Otherwise,
+// values in a map field will be serialized in map iteration order.
+func (cb *Buffer) SetDeterministic(deterministic bool) {
+	(*codec.Buffer)(cb).SetDeterministic(deterministic)
+}
+
+// IsDeterministic returns whether or not this buffer is configured to encode
+// messages deterministically.
+func (cb *Buffer) IsDeterministic() bool {
+	return (*codec.Buffer)(cb).IsDeterministic()
+}
+
+// Reset resets this buffer back to empty. Any subsequent writes/encodes
+// to the buffer will allocate a new backing slice of bytes.
+func (cb *Buffer) Reset() {
+	(*codec.Buffer)(cb).Reset()
+}
+
+// Bytes returns the slice of bytes remaining in the buffer. Note that
+// this does not perform a copy: if the contents of the returned slice
+// are modified, the modifications will be visible to subsequent reads
+// via the buffer.
+func (cb *Buffer) Bytes() []byte {
+	return (*codec.Buffer)(cb).Bytes()
+}
+
+// String returns the remaining bytes in the buffer as a string.
+func (cb *Buffer) String() string {
+	return (*codec.Buffer)(cb).String()
+}
+
+// EOF returns true if there are no more bytes remaining to read.
+func (cb *Buffer) EOF() bool {
+	return (*codec.Buffer)(cb).EOF()
+}
+
+// Skip attempts to skip the given number of bytes in the input. If
+// the input has fewer bytes than the given count, io.ErrUnexpectedEOF
+// is returned and the buffer is unchanged. Otherwise, the given number
+// of bytes are skipped and nil is returned.
+func (cb *Buffer) Skip(count int) error {
+	return (*codec.Buffer)(cb).Skip(count)
+
+}
+
+// Len returns the remaining number of bytes in the buffer.
+func (cb *Buffer) Len() int {
+	return (*codec.Buffer)(cb).Len()
+}
+
+// Read implements the io.Reader interface. If there are no bytes
+// remaining in the buffer, it will return 0, io.EOF. Otherwise,
+// it reads max(len(dest), cb.Len()) bytes from input and copies
+// them into dest. It returns the number of bytes copied and a nil
+// error in this case.
+func (cb *Buffer) Read(dest []byte) (int, error) {
+	return (*codec.Buffer)(cb).Read(dest)
+}
+
+var _ io.Reader = (*Buffer)(nil)
+
+// Write implements the io.Writer interface. It always returns
+// len(data), nil.
+func (cb *Buffer) Write(data []byte) (int, error) {
+	return (*codec.Buffer)(cb).Write(data)
+}
+
+var _ io.Writer = (*Buffer)(nil)
+
+// DecodeVarint reads a varint-encoded integer from the Buffer.
+// This is the format for the
+// int32, int64, uint32, uint64, bool, and enum
+// protocol buffer types.
+func (cb *Buffer) DecodeVarint() (uint64, error) {
+	return (*codec.Buffer)(cb).DecodeVarint()
+}
+
+// DecodeTagAndWireType decodes a field tag and wire type from input.
+// This reads a varint and then extracts the two fields from the varint
+// value read.
+func (cb *Buffer) DecodeTagAndWireType() (tag int32, wireType int8, err error) {
+	return (*codec.Buffer)(cb).DecodeTagAndWireType()
+}
+
+// DecodeFixed64 reads a 64-bit integer from the Buffer.
+// This is the format for the
+// fixed64, sfixed64, and double protocol buffer types.
+func (cb *Buffer) DecodeFixed64() (x uint64, err error) {
+	return (*codec.Buffer)(cb).DecodeFixed64()
+}
+
+// DecodeFixed32 reads a 32-bit integer from the Buffer.
+// This is the format for the
+// fixed32, sfixed32, and float protocol buffer types.
+func (cb *Buffer) DecodeFixed32() (x uint64, err error) {
+	return (*codec.Buffer)(cb).DecodeFixed32()
+}
+
+// DecodeRawBytes reads a count-delimited byte buffer from the Buffer.
+// This is the format used for the bytes protocol buffer
+// type and for embedded messages.
+func (cb *Buffer) DecodeRawBytes(alloc bool) (buf []byte, err error) {
+	return (*codec.Buffer)(cb).DecodeRawBytes(alloc)
+}
+
+// ReadGroup reads the input until a "group end" tag is found
+// and returns the data up to that point. Subsequent reads from
+// the buffer will read data after the group end tag. If alloc
+// is true, the data is copied to a new slice before being returned.
+// Otherwise, the returned slice is a view into the buffer's
+// underlying byte slice.
+//
+// This function correctly handles nested groups: if a "group start"
+// tag is found, then that group's end tag will be included in the
+// returned data.
+func (cb *Buffer) ReadGroup(alloc bool) ([]byte, error) {
+	return (*codec.Buffer)(cb).ReadGroup(alloc)
+}
+
+// SkipGroup is like ReadGroup, except that it discards the
+// data and just advances the buffer to point to the input
+// right *after* the "group end" tag.
+func (cb *Buffer) SkipGroup() error {
+	return (*codec.Buffer)(cb).SkipGroup()
+}
+
+// SkipField attempts to skip the value of a field with the given wire
+// type. When consuming a protobuf-encoded stream, it can be called immediately
+// after DecodeTagAndWireType to discard the subsequent data for the field.
+func (cb *Buffer) SkipField(wireType int8) error {
+	return (*codec.Buffer)(cb).SkipField(wireType)
+}
+
+// EncodeVarint writes a varint-encoded integer to the Buffer.
+// This is the format for the
+// int32, int64, uint32, uint64, bool, and enum
+// protocol buffer types.
+func (cb *Buffer) EncodeVarint(x uint64) error {
+	return (*codec.Buffer)(cb).EncodeVarint(x)
+}
+
+// EncodeTagAndWireType encodes the given field tag and wire type to the
+// buffer. This combines the two values and then writes them as a varint.
+func (cb *Buffer) EncodeTagAndWireType(tag int32, wireType int8) error {
+	return (*codec.Buffer)(cb).EncodeTagAndWireType(tag, wireType)
+}
+
+// EncodeFixed64 writes a 64-bit integer to the Buffer.
+// This is the format for the
+// fixed64, sfixed64, and double protocol buffer types.
+func (cb *Buffer) EncodeFixed64(x uint64) error {
+	return (*codec.Buffer)(cb).EncodeFixed64(x)
+
+}
+
+// EncodeFixed32 writes a 32-bit integer to the Buffer.
+// This is the format for the
+// fixed32, sfixed32, and float protocol buffer types.
+func (cb *Buffer) EncodeFixed32(x uint64) error {
+	return (*codec.Buffer)(cb).EncodeFixed32(x)
+}
+
+// EncodeRawBytes writes a count-delimited byte buffer to the Buffer.
+// This is the format used for the bytes protocol buffer
+// type and for embedded messages.
+func (cb *Buffer) EncodeRawBytes(b []byte) error {
+	return (*codec.Buffer)(cb).EncodeRawBytes(b)
+}
+
+// EncodeMessage writes the given message to the buffer.
+func (cb *Buffer) EncodeMessage(pm proto.Message) error {
+	return (*codec.Buffer)(cb).EncodeMessage(pm)
+}
+
+// EncodeDelimitedMessage writes the given message to the buffer with a
+// varint-encoded length prefix (the delimiter).
+func (cb *Buffer) EncodeDelimitedMessage(pm proto.Message) error {
+	return (*codec.Buffer)(cb).EncodeDelimitedMessage(pm)
+}
diff --git a/vendor/github.com/jhump/protoreflect/codec/decode_fields.go b/vendor/github.com/jhump/protoreflect/codec/decode_fields.go
new file mode 100644
index 0000000..02f8a32
--- /dev/null
+++ b/vendor/github.com/jhump/protoreflect/codec/decode_fields.go
@@ -0,0 +1,318 @@
+package codec
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"math"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/protoc-gen-go/descriptor"
+
+	"github.com/jhump/protoreflect/desc"
+)
+
+var varintTypes = map[descriptor.FieldDescriptorProto_Type]bool{}
+var fixed32Types = map[descriptor.FieldDescriptorProto_Type]bool{}
+var fixed64Types = map[descriptor.FieldDescriptorProto_Type]bool{}
+
+func init() {
+	varintTypes[descriptor.FieldDescriptorProto_TYPE_BOOL] = true
+	varintTypes[descriptor.FieldDescriptorProto_TYPE_INT32] = true
+	varintTypes[descriptor.FieldDescriptorProto_TYPE_INT64] = true
+	varintTypes[descriptor.FieldDescriptorProto_TYPE_UINT32] = true
+	varintTypes[descriptor.FieldDescriptorProto_TYPE_UINT64] = true
+	varintTypes[descriptor.FieldDescriptorProto_TYPE_SINT32] = true
+	varintTypes[descriptor.FieldDescriptorProto_TYPE_SINT64] = true
+	varintTypes[descriptor.FieldDescriptorProto_TYPE_ENUM] = true
+
+	fixed32Types[descriptor.FieldDescriptorProto_TYPE_FIXED32] = true
+	fixed32Types[descriptor.FieldDescriptorProto_TYPE_SFIXED32] = true
+	fixed32Types[descriptor.FieldDescriptorProto_TYPE_FLOAT] = true
+
+	fixed64Types[descriptor.FieldDescriptorProto_TYPE_FIXED64] = true
+	fixed64Types[descriptor.FieldDescriptorProto_TYPE_SFIXED64] = true
+	fixed64Types[descriptor.FieldDescriptorProto_TYPE_DOUBLE] = true
+}
+
+// ErrWireTypeEndGroup is returned from DecodeFieldValue if the tag and wire-type
+// it reads indicates an end-group marker.
+var ErrWireTypeEndGroup = errors.New("unexpected wire type: end group")
+
+// MessageFactory is used to instantiate messages when DecodeFieldValue needs to
+// decode a message value.
+//
+// Also see MessageFactory in "github.com/jhump/protoreflect/dynamic", which
+// implements this interface.
+type MessageFactory interface {
+	NewMessage(md *desc.MessageDescriptor) proto.Message
+}
+
+// UnknownField represents a field that was parsed from the binary wire
+// format for a message, but was not a recognized field number. Enough
+// information is preserved so that re-serializing the message won't lose
+// any of the unrecognized data.
+type UnknownField struct {
+	// The tag number for the unrecognized field.
+	Tag int32
+
+	// Encoding indicates how the unknown field was encoded on the wire. If it
+	// is proto.WireBytes or proto.WireGroupStart then Contents will be set to
+	// the raw bytes. If it is proto.WireTypeFixed32 then the data is in the least
+	// significant 32 bits of Value. Otherwise, the data is in all 64 bits of
+	// Value.
+	Encoding int8
+	Contents []byte
+	Value    uint64
+}
+
+// DecodeZigZag32 decodes a signed 32-bit integer from the given
+// zig-zag encoded value.
+func DecodeZigZag32(v uint64) int32 {
+	return int32((uint32(v) >> 1) ^ uint32((int32(v&1)<<31)>>31))
+}
+
+// DecodeZigZag64 decodes a signed 64-bit integer from the given
+// zig-zag encoded value.
+func DecodeZigZag64(v uint64) int64 {
+	return int64((v >> 1) ^ uint64((int64(v&1)<<63)>>63))
+}
+
+// DecodeFieldValue will read a field value from the buffer and return its
+// value and the corresponding field descriptor. The given function is used
+// to lookup a field descriptor by tag number. The given factory is used to
+// instantiate a message if the field value is (or contains) a message value.
+//
+// On error, the field descriptor and value are typically nil. However, if the
+// error returned is ErrWireTypeEndGroup, the returned value will indicate any
+// tag number encoded in the end-group marker.
+//
+// If the field descriptor returned is nil, that means that the given function
+// returned nil. This is expected to happen for unrecognized tag numbers. In
+// that case, no error is returned, and the value will be an UnknownField.
+func (cb *Buffer) DecodeFieldValue(fieldFinder func(int32) *desc.FieldDescriptor, fact MessageFactory) (*desc.FieldDescriptor, interface{}, error) {
+	if cb.EOF() {
+		return nil, nil, io.EOF
+	}
+	tagNumber, wireType, err := cb.DecodeTagAndWireType()
+	if err != nil {
+		return nil, nil, err
+	}
+	if wireType == proto.WireEndGroup {
+		return nil, tagNumber, ErrWireTypeEndGroup
+	}
+	fd := fieldFinder(tagNumber)
+	if fd == nil {
+		val, err := cb.decodeUnknownField(tagNumber, wireType)
+		return nil, val, err
+	}
+	val, err := cb.decodeKnownField(fd, wireType, fact)
+	return fd, val, err
+}
+
+// DecodeScalarField extracts a properly-typed value from v. The returned value's
+// type depends on the given field descriptor type. It will be the same type as
+// generated structs use for the field descriptor's type. Enum types will return
+// an int32. If the given field type uses length-delimited encoding (nested
+// messages, bytes, and strings), an error is returned.
+func DecodeScalarField(fd *desc.FieldDescriptor, v uint64) (interface{}, error) {
+	switch fd.GetType() {
+	case descriptor.FieldDescriptorProto_TYPE_BOOL:
+		return v != 0, nil
+	case descriptor.FieldDescriptorProto_TYPE_UINT32,
+		descriptor.FieldDescriptorProto_TYPE_FIXED32:
+		if v > math.MaxUint32 {
+			return nil, ErrOverflow
+		}
+		return uint32(v), nil
+
+	case descriptor.FieldDescriptorProto_TYPE_INT32,
+		descriptor.FieldDescriptorProto_TYPE_ENUM:
+		s := int64(v)
+		if s > math.MaxInt32 || s < math.MinInt32 {
+			return nil, ErrOverflow
+		}
+		return int32(s), nil
+
+	case descriptor.FieldDescriptorProto_TYPE_SFIXED32:
+		if v > math.MaxUint32 {
+			return nil, ErrOverflow
+		}
+		return int32(v), nil
+
+	case descriptor.FieldDescriptorProto_TYPE_SINT32:
+		if v > math.MaxUint32 {
+			return nil, ErrOverflow
+		}
+		return DecodeZigZag32(v), nil
+
+	case descriptor.FieldDescriptorProto_TYPE_UINT64,
+		descriptor.FieldDescriptorProto_TYPE_FIXED64:
+		return v, nil
+
+	case descriptor.FieldDescriptorProto_TYPE_INT64,
+		descriptor.FieldDescriptorProto_TYPE_SFIXED64:
+		return int64(v), nil
+
+	case descriptor.FieldDescriptorProto_TYPE_SINT64:
+		return DecodeZigZag64(v), nil
+
+	case descriptor.FieldDescriptorProto_TYPE_FLOAT:
+		if v > math.MaxUint32 {
+			return nil, ErrOverflow
+		}
+		return math.Float32frombits(uint32(v)), nil
+
+	case descriptor.FieldDescriptorProto_TYPE_DOUBLE:
+		return math.Float64frombits(v), nil
+
+	default:
+		// bytes, string, message, and group cannot be represented as a simple numeric value
+		return nil, fmt.Errorf("bad input; field %s requires length-delimited wire type", fd.GetFullyQualifiedName())
+	}
+}
+
+// DecodeLengthDelimitedField extracts a properly-typed value from bytes. The
+// returned value's type will usually be []byte, string, or, for nested messages,
+// the type returned from the given message factory. However, since repeated
+// scalar fields can be length-delimited, when they used packed encoding, it can
+// also return an []interface{}, where each element is a scalar value. Furthermore,
+// it could return a scalar type, not in a slice, if the given field descriptor is
+// not repeated. This is to support cases where a field is changed from optional
+// to repeated. New code may emit a packed repeated representation, but old code
+// still expects a single scalar value. In this case, if the actual data in bytes
+// contains multiple values, only the last value is returned.
+func DecodeLengthDelimitedField(fd *desc.FieldDescriptor, bytes []byte, mf MessageFactory) (interface{}, error) {
+	switch {
+	case fd.GetType() == descriptor.FieldDescriptorProto_TYPE_BYTES:
+		return bytes, nil
+
+	case fd.GetType() == descriptor.FieldDescriptorProto_TYPE_STRING:
+		return string(bytes), nil
+
+	case fd.GetType() == descriptor.FieldDescriptorProto_TYPE_MESSAGE ||
+		fd.GetType() == descriptor.FieldDescriptorProto_TYPE_GROUP:
+		msg := mf.NewMessage(fd.GetMessageType())
+		err := proto.Unmarshal(bytes, msg)
+		if err != nil {
+			return nil, err
+		} else {
+			return msg, nil
+		}
+
+	default:
+		// even if the field is not repeated or not packed, we still parse it as such for
+		// backwards compatibility (e.g. message we are de-serializing could have been both
+		// repeated and packed at the time of serialization)
+		packedBuf := NewBuffer(bytes)
+		var slice []interface{}
+		var val interface{}
+		for !packedBuf.EOF() {
+			var v uint64
+			var err error
+			if varintTypes[fd.GetType()] {
+				v, err = packedBuf.DecodeVarint()
+			} else if fixed32Types[fd.GetType()] {
+				v, err = packedBuf.DecodeFixed32()
+			} else if fixed64Types[fd.GetType()] {
+				v, err = packedBuf.DecodeFixed64()
+			} else {
+				return nil, fmt.Errorf("bad input; cannot parse length-delimited wire type for field %s", fd.GetFullyQualifiedName())
+			}
+			if err != nil {
+				return nil, err
+			}
+			val, err = DecodeScalarField(fd, v)
+			if err != nil {
+				return nil, err
+			}
+			if fd.IsRepeated() {
+				slice = append(slice, val)
+			}
+		}
+		if fd.IsRepeated() {
+			return slice, nil
+		} else {
+			// if not a repeated field, last value wins
+			return val, nil
+		}
+	}
+}
+
+func (b *Buffer) decodeKnownField(fd *desc.FieldDescriptor, encoding int8, fact MessageFactory) (interface{}, error) {
+	var val interface{}
+	var err error
+	switch encoding {
+	case proto.WireFixed32:
+		var num uint64
+		num, err = b.DecodeFixed32()
+		if err == nil {
+			val, err = DecodeScalarField(fd, num)
+		}
+	case proto.WireFixed64:
+		var num uint64
+		num, err = b.DecodeFixed64()
+		if err == nil {
+			val, err = DecodeScalarField(fd, num)
+		}
+	case proto.WireVarint:
+		var num uint64
+		num, err = b.DecodeVarint()
+		if err == nil {
+			val, err = DecodeScalarField(fd, num)
+		}
+
+	case proto.WireBytes:
+		alloc := fd.GetType() == descriptor.FieldDescriptorProto_TYPE_BYTES
+		var raw []byte
+		raw, err = b.DecodeRawBytes(alloc)
+		if err == nil {
+			val, err = DecodeLengthDelimitedField(fd, raw, fact)
+		}
+
+	case proto.WireStartGroup:
+		if fd.GetMessageType() == nil {
+			return nil, fmt.Errorf("cannot parse field %s from group-encoded wire type", fd.GetFullyQualifiedName())
+		}
+		msg := fact.NewMessage(fd.GetMessageType())
+		var data []byte
+		data, err = b.ReadGroup(false)
+		if err == nil {
+			err = proto.Unmarshal(data, msg)
+			if err == nil {
+				val = msg
+			}
+		}
+
+	default:
+		return nil, ErrBadWireType
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	return val, nil
+}
+
+func (b *Buffer) decodeUnknownField(tagNumber int32, encoding int8) (interface{}, error) {
+	u := UnknownField{Tag: tagNumber, Encoding: encoding}
+	var err error
+	switch encoding {
+	case proto.WireFixed32:
+		u.Value, err = b.DecodeFixed32()
+	case proto.WireFixed64:
+		u.Value, err = b.DecodeFixed64()
+	case proto.WireVarint:
+		u.Value, err = b.DecodeVarint()
+	case proto.WireBytes:
+		u.Contents, err = b.DecodeRawBytes(true)
+	case proto.WireStartGroup:
+		u.Contents, err = b.ReadGroup(true)
+	default:
+		err = ErrBadWireType
+	}
+	if err != nil {
+		return nil, err
+	}
+	return u, nil
+}
diff --git a/vendor/github.com/jhump/protoreflect/codec/doc.go b/vendor/github.com/jhump/protoreflect/codec/doc.go
new file mode 100644
index 0000000..f76499f
--- /dev/null
+++ b/vendor/github.com/jhump/protoreflect/codec/doc.go
@@ -0,0 +1,7 @@
+// Package codec contains a reader/write type that assists with encoding
+// and decoding protobuf's binary representation.
+//
+// The code in this package began as a fork of proto.Buffer but provides
+// additional API to make it more useful to code that needs to dynamically
+// process or produce the protobuf binary format.
+package codec
diff --git a/vendor/github.com/jhump/protoreflect/codec/encode_fields.go b/vendor/github.com/jhump/protoreflect/codec/encode_fields.go
new file mode 100644
index 0000000..499aa95
--- /dev/null
+++ b/vendor/github.com/jhump/protoreflect/codec/encode_fields.go
@@ -0,0 +1,288 @@
+package codec
+
+import (
+	"fmt"
+	"math"
+	"reflect"
+	"sort"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/protoc-gen-go/descriptor"
+
+	"github.com/jhump/protoreflect/desc"
+)
+
+// EncodeZigZag64 does zig-zag encoding to convert the given
+// signed 64-bit integer into a form that can be expressed
+// efficiently as a varint, even for negative values.
+func EncodeZigZag64(v int64) uint64 {
+	return (uint64(v) << 1) ^ uint64(v>>63)
+}
+
+// EncodeZigZag32 does zig-zag encoding to convert the given
+// signed 32-bit integer into a form that can be expressed
+// efficiently as a varint, even for negative values.
+func EncodeZigZag32(v int32) uint64 {
+	return uint64((uint32(v) << 1) ^ uint32((v >> 31)))
+}
+
+func (cb *Buffer) EncodeFieldValue(fd *desc.FieldDescriptor, val interface{}) error {
+	if fd.IsMap() {
+		mp := val.(map[interface{}]interface{})
+		entryType := fd.GetMessageType()
+		keyType := entryType.FindFieldByNumber(1)
+		valType := entryType.FindFieldByNumber(2)
+		var entryBuffer Buffer
+		if cb.IsDeterministic() {
+			entryBuffer.SetDeterministic(true)
+			keys := make([]interface{}, 0, len(mp))
+			for k := range mp {
+				keys = append(keys, k)
+			}
+			sort.Sort(sortable(keys))
+			for _, k := range keys {
+				v := mp[k]
+				entryBuffer.Reset()
+				if err := entryBuffer.encodeFieldElement(keyType, k); err != nil {
+					return err
+				}
+				rv := reflect.ValueOf(v)
+				if rv.Kind() != reflect.Ptr || !rv.IsNil() {
+					if err := entryBuffer.encodeFieldElement(valType, v); err != nil {
+						return err
+					}
+				}
+				if err := cb.EncodeTagAndWireType(fd.GetNumber(), proto.WireBytes); err != nil {
+					return err
+				}
+				if err := cb.EncodeRawBytes(entryBuffer.Bytes()); err != nil {
+					return err
+				}
+			}
+		} else {
+			for k, v := range mp {
+				entryBuffer.Reset()
+				if err := entryBuffer.encodeFieldElement(keyType, k); err != nil {
+					return err
+				}
+				rv := reflect.ValueOf(v)
+				if rv.Kind() != reflect.Ptr || !rv.IsNil() {
+					if err := entryBuffer.encodeFieldElement(valType, v); err != nil {
+						return err
+					}
+				}
+				if err := cb.EncodeTagAndWireType(fd.GetNumber(), proto.WireBytes); err != nil {
+					return err
+				}
+				if err := cb.EncodeRawBytes(entryBuffer.Bytes()); err != nil {
+					return err
+				}
+			}
+		}
+		return nil
+	} else if fd.IsRepeated() {
+		sl := val.([]interface{})
+		wt, err := getWireType(fd.GetType())
+		if err != nil {
+			return err
+		}
+		if isPacked(fd) && len(sl) > 0 &&
+			(wt == proto.WireVarint || wt == proto.WireFixed32 || wt == proto.WireFixed64) {
+			// packed repeated field
+			var packedBuffer Buffer
+			for _, v := range sl {
+				if err := packedBuffer.encodeFieldValue(fd, v); err != nil {
+					return err
+				}
+			}
+			if err := cb.EncodeTagAndWireType(fd.GetNumber(), proto.WireBytes); err != nil {
+				return err
+			}
+			return cb.EncodeRawBytes(packedBuffer.Bytes())
+		} else {
+			// non-packed repeated field
+			for _, v := range sl {
+				if err := cb.encodeFieldElement(fd, v); err != nil {
+					return err
+				}
+			}
+			return nil
+		}
+	} else {
+		return cb.encodeFieldElement(fd, val)
+	}
+}
+
+func isPacked(fd *desc.FieldDescriptor) bool {
+	opts := fd.AsFieldDescriptorProto().GetOptions()
+	// if set, use that value
+	if opts != nil && opts.Packed != nil {
+		return opts.GetPacked()
+	}
+	// if unset: proto2 defaults to false, proto3 to true
+	return fd.GetFile().IsProto3()
+}
+
+// sortable is used to sort map keys. Values will be integers (int32, int64, uint32, and uint64),
+// bools, or strings.
+type sortable []interface{}
+
+func (s sortable) Len() int {
+	return len(s)
+}
+
+func (s sortable) Less(i, j int) bool {
+	vi := s[i]
+	vj := s[j]
+	switch reflect.TypeOf(vi).Kind() {
+	case reflect.Int32:
+		return vi.(int32) < vj.(int32)
+	case reflect.Int64:
+		return vi.(int64) < vj.(int64)
+	case reflect.Uint32:
+		return vi.(uint32) < vj.(uint32)
+	case reflect.Uint64:
+		return vi.(uint64) < vj.(uint64)
+	case reflect.String:
+		return vi.(string) < vj.(string)
+	case reflect.Bool:
+		return !vi.(bool) && vj.(bool)
+	default:
+		panic(fmt.Sprintf("cannot compare keys of type %v", reflect.TypeOf(vi)))
+	}
+}
+
+func (s sortable) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+func (b *Buffer) encodeFieldElement(fd *desc.FieldDescriptor, val interface{}) error {
+	wt, err := getWireType(fd.GetType())
+	if err != nil {
+		return err
+	}
+	if err := b.EncodeTagAndWireType(fd.GetNumber(), wt); err != nil {
+		return err
+	}
+	if err := b.encodeFieldValue(fd, val); err != nil {
+		return err
+	}
+	if wt == proto.WireStartGroup {
+		return b.EncodeTagAndWireType(fd.GetNumber(), proto.WireEndGroup)
+	}
+	return nil
+}
+
+func (b *Buffer) encodeFieldValue(fd *desc.FieldDescriptor, val interface{}) error {
+	switch fd.GetType() {
+	case descriptor.FieldDescriptorProto_TYPE_BOOL:
+		v := val.(bool)
+		if v {
+			return b.EncodeVarint(1)
+		}
+		return b.EncodeVarint(0)
+
+	case descriptor.FieldDescriptorProto_TYPE_ENUM,
+		descriptor.FieldDescriptorProto_TYPE_INT32:
+		v := val.(int32)
+		return b.EncodeVarint(uint64(v))
+
+	case descriptor.FieldDescriptorProto_TYPE_SFIXED32:
+		v := val.(int32)
+		return b.EncodeFixed32(uint64(v))
+
+	case descriptor.FieldDescriptorProto_TYPE_SINT32:
+		v := val.(int32)
+		return b.EncodeVarint(EncodeZigZag32(v))
+
+	case descriptor.FieldDescriptorProto_TYPE_UINT32:
+		v := val.(uint32)
+		return b.EncodeVarint(uint64(v))
+
+	case descriptor.FieldDescriptorProto_TYPE_FIXED32:
+		v := val.(uint32)
+		return b.EncodeFixed32(uint64(v))
+
+	case descriptor.FieldDescriptorProto_TYPE_INT64:
+		v := val.(int64)
+		return b.EncodeVarint(uint64(v))
+
+	case descriptor.FieldDescriptorProto_TYPE_SFIXED64:
+		v := val.(int64)
+		return b.EncodeFixed64(uint64(v))
+
+	case descriptor.FieldDescriptorProto_TYPE_SINT64:
+		v := val.(int64)
+		return b.EncodeVarint(EncodeZigZag64(v))
+
+	case descriptor.FieldDescriptorProto_TYPE_UINT64:
+		v := val.(uint64)
+		return b.EncodeVarint(v)
+
+	case descriptor.FieldDescriptorProto_TYPE_FIXED64:
+		v := val.(uint64)
+		return b.EncodeFixed64(v)
+
+	case descriptor.FieldDescriptorProto_TYPE_DOUBLE:
+		v := val.(float64)
+		return b.EncodeFixed64(math.Float64bits(v))
+
+	case descriptor.FieldDescriptorProto_TYPE_FLOAT:
+		v := val.(float32)
+		return b.EncodeFixed32(uint64(math.Float32bits(v)))
+
+	case descriptor.FieldDescriptorProto_TYPE_BYTES:
+		v := val.([]byte)
+		return b.EncodeRawBytes(v)
+
+	case descriptor.FieldDescriptorProto_TYPE_STRING:
+		v := val.(string)
+		return b.EncodeRawBytes(([]byte)(v))
+
+	case descriptor.FieldDescriptorProto_TYPE_MESSAGE:
+		return b.EncodeDelimitedMessage(val.(proto.Message))
+
+	case descriptor.FieldDescriptorProto_TYPE_GROUP:
+		// just append the nested message to this buffer
+		return b.EncodeMessage(val.(proto.Message))
+		// whosoever writeth start-group tag (e.g. caller) is responsible for writing end-group tag
+
+	default:
+		return fmt.Errorf("unrecognized field type: %v", fd.GetType())
+	}
+}
+
+func getWireType(t descriptor.FieldDescriptorProto_Type) (int8, error) {
+	switch t {
+	case descriptor.FieldDescriptorProto_TYPE_ENUM,
+		descriptor.FieldDescriptorProto_TYPE_BOOL,
+		descriptor.FieldDescriptorProto_TYPE_INT32,
+		descriptor.FieldDescriptorProto_TYPE_SINT32,
+		descriptor.FieldDescriptorProto_TYPE_UINT32,
+		descriptor.FieldDescriptorProto_TYPE_INT64,
+		descriptor.FieldDescriptorProto_TYPE_SINT64,
+		descriptor.FieldDescriptorProto_TYPE_UINT64:
+		return proto.WireVarint, nil
+
+	case descriptor.FieldDescriptorProto_TYPE_FIXED32,
+		descriptor.FieldDescriptorProto_TYPE_SFIXED32,
+		descriptor.FieldDescriptorProto_TYPE_FLOAT:
+		return proto.WireFixed32, nil
+
+	case descriptor.FieldDescriptorProto_TYPE_FIXED64,
+		descriptor.FieldDescriptorProto_TYPE_SFIXED64,
+		descriptor.FieldDescriptorProto_TYPE_DOUBLE:
+		return proto.WireFixed64, nil
+
+	case descriptor.FieldDescriptorProto_TYPE_BYTES,
+		descriptor.FieldDescriptorProto_TYPE_STRING,
+		descriptor.FieldDescriptorProto_TYPE_MESSAGE:
+		return proto.WireBytes, nil
+
+	case descriptor.FieldDescriptorProto_TYPE_GROUP:
+		return proto.WireStartGroup, nil
+
+	default:
+		return 0, ErrBadWireType
+	}
+}