diff --git a/vendor/github.com/golang/protobuf/proto/clone.go b/vendor/github.com/golang/protobuf/proto/clone.go
new file mode 100644
index 0000000..3cd3249
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/clone.go
@@ -0,0 +1,253 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2011 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Protocol buffer deep copy and merge.
+// TODO: RawMessage.
+
+package proto
+
+import (
+	"fmt"
+	"log"
+	"reflect"
+	"strings"
+)
+
+// Clone returns a deep copy of a protocol buffer.
+func Clone(src Message) Message {
+	in := reflect.ValueOf(src)
+	if in.IsNil() {
+		return src
+	}
+	out := reflect.New(in.Type().Elem())
+	dst := out.Interface().(Message)
+	Merge(dst, src)
+	return dst
+}
+
+// Merger is the interface representing objects that can merge messages of the same type.
+type Merger interface {
+	// Merge merges src into this message.
+	// Required and optional fields that are set in src will be set to that value in dst.
+	// Elements of repeated fields will be appended.
+	//
+	// Merge may panic if called with a different argument type than the receiver.
+	Merge(src Message)
+}
+
+// generatedMerger is the custom merge method that generated protos will have.
+// We must add this method since a generate Merge method will conflict with
+// many existing protos that have a Merge data field already defined.
+type generatedMerger interface {
+	XXX_Merge(src Message)
+}
+
+// Merge merges src into dst.
+// Required and optional fields that are set in src will be set to that value in dst.
+// Elements of repeated fields will be appended.
+// Merge panics if src and dst are not the same type, or if dst is nil.
+func Merge(dst, src Message) {
+	if m, ok := dst.(Merger); ok {
+		m.Merge(src)
+		return
+	}
+
+	in := reflect.ValueOf(src)
+	out := reflect.ValueOf(dst)
+	if out.IsNil() {
+		panic("proto: nil destination")
+	}
+	if in.Type() != out.Type() {
+		panic(fmt.Sprintf("proto.Merge(%T, %T) type mismatch", dst, src))
+	}
+	if in.IsNil() {
+		return // Merge from nil src is a noop
+	}
+	if m, ok := dst.(generatedMerger); ok {
+		m.XXX_Merge(src)
+		return
+	}
+	mergeStruct(out.Elem(), in.Elem())
+}
+
+func mergeStruct(out, in reflect.Value) {
+	sprop := GetProperties(in.Type())
+	for i := 0; i < in.NumField(); i++ {
+		f := in.Type().Field(i)
+		if strings.HasPrefix(f.Name, "XXX_") {
+			continue
+		}
+		mergeAny(out.Field(i), in.Field(i), false, sprop.Prop[i])
+	}
+
+	if emIn, err := extendable(in.Addr().Interface()); err == nil {
+		emOut, _ := extendable(out.Addr().Interface())
+		mIn, muIn := emIn.extensionsRead()
+		if mIn != nil {
+			mOut := emOut.extensionsWrite()
+			muIn.Lock()
+			mergeExtension(mOut, mIn)
+			muIn.Unlock()
+		}
+	}
+
+	uf := in.FieldByName("XXX_unrecognized")
+	if !uf.IsValid() {
+		return
+	}
+	uin := uf.Bytes()
+	if len(uin) > 0 {
+		out.FieldByName("XXX_unrecognized").SetBytes(append([]byte(nil), uin...))
+	}
+}
+
+// mergeAny performs a merge between two values of the same type.
+// viaPtr indicates whether the values were indirected through a pointer (implying proto2).
+// prop is set if this is a struct field (it may be nil).
+func mergeAny(out, in reflect.Value, viaPtr bool, prop *Properties) {
+	if in.Type() == protoMessageType {
+		if !in.IsNil() {
+			if out.IsNil() {
+				out.Set(reflect.ValueOf(Clone(in.Interface().(Message))))
+			} else {
+				Merge(out.Interface().(Message), in.Interface().(Message))
+			}
+		}
+		return
+	}
+	switch in.Kind() {
+	case reflect.Bool, reflect.Float32, reflect.Float64, reflect.Int32, reflect.Int64,
+		reflect.String, reflect.Uint32, reflect.Uint64:
+		if !viaPtr && isProto3Zero(in) {
+			return
+		}
+		out.Set(in)
+	case reflect.Interface:
+		// Probably a oneof field; copy non-nil values.
+		if in.IsNil() {
+			return
+		}
+		// Allocate destination if it is not set, or set to a different type.
+		// Otherwise we will merge as normal.
+		if out.IsNil() || out.Elem().Type() != in.Elem().Type() {
+			out.Set(reflect.New(in.Elem().Elem().Type())) // interface -> *T -> T -> new(T)
+		}
+		mergeAny(out.Elem(), in.Elem(), false, nil)
+	case reflect.Map:
+		if in.Len() == 0 {
+			return
+		}
+		if out.IsNil() {
+			out.Set(reflect.MakeMap(in.Type()))
+		}
+		// For maps with value types of *T or []byte we need to deep copy each value.
+		elemKind := in.Type().Elem().Kind()
+		for _, key := range in.MapKeys() {
+			var val reflect.Value
+			switch elemKind {
+			case reflect.Ptr:
+				val = reflect.New(in.Type().Elem().Elem())
+				mergeAny(val, in.MapIndex(key), false, nil)
+			case reflect.Slice:
+				val = in.MapIndex(key)
+				val = reflect.ValueOf(append([]byte{}, val.Bytes()...))
+			default:
+				val = in.MapIndex(key)
+			}
+			out.SetMapIndex(key, val)
+		}
+	case reflect.Ptr:
+		if in.IsNil() {
+			return
+		}
+		if out.IsNil() {
+			out.Set(reflect.New(in.Elem().Type()))
+		}
+		mergeAny(out.Elem(), in.Elem(), true, nil)
+	case reflect.Slice:
+		if in.IsNil() {
+			return
+		}
+		if in.Type().Elem().Kind() == reflect.Uint8 {
+			// []byte is a scalar bytes field, not a repeated field.
+
+			// Edge case: if this is in a proto3 message, a zero length
+			// bytes field is considered the zero value, and should not
+			// be merged.
+			if prop != nil && prop.proto3 && in.Len() == 0 {
+				return
+			}
+
+			// Make a deep copy.
+			// Append to []byte{} instead of []byte(nil) so that we never end up
+			// with a nil result.
+			out.SetBytes(append([]byte{}, in.Bytes()...))
+			return
+		}
+		n := in.Len()
+		if out.IsNil() {
+			out.Set(reflect.MakeSlice(in.Type(), 0, n))
+		}
+		switch in.Type().Elem().Kind() {
+		case reflect.Bool, reflect.Float32, reflect.Float64, reflect.Int32, reflect.Int64,
+			reflect.String, reflect.Uint32, reflect.Uint64:
+			out.Set(reflect.AppendSlice(out, in))
+		default:
+			for i := 0; i < n; i++ {
+				x := reflect.Indirect(reflect.New(in.Type().Elem()))
+				mergeAny(x, in.Index(i), false, nil)
+				out.Set(reflect.Append(out, x))
+			}
+		}
+	case reflect.Struct:
+		mergeStruct(out, in)
+	default:
+		// unknown type, so not a protocol buffer
+		log.Printf("proto: don't know how to copy %v", in)
+	}
+}
+
+func mergeExtension(out, in map[int32]Extension) {
+	for extNum, eIn := range in {
+		eOut := Extension{desc: eIn.desc}
+		if eIn.value != nil {
+			v := reflect.New(reflect.TypeOf(eIn.value)).Elem()
+			mergeAny(v, reflect.ValueOf(eIn.value), false, nil)
+			eOut.value = v.Interface()
+		}
+		if eIn.enc != nil {
+			eOut.enc = make([]byte, len(eIn.enc))
+			copy(eOut.enc, eIn.enc)
+		}
+
+		out[extNum] = eOut
+	}
+}
diff --git a/vendor/github.com/golang/protobuf/proto/decode.go b/vendor/github.com/golang/protobuf/proto/decode.go
new file mode 100644
index 0000000..d9aa3c4
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/decode.go
@@ -0,0 +1,428 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2010 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package proto
+
+/*
+ * Routines for decoding protocol buffer data to construct in-memory representations.
+ */
+
+import (
+	"errors"
+	"fmt"
+	"io"
+)
+
+// errOverflow is returned when an integer is too large to be represented.
+var errOverflow = errors.New("proto: integer overflow")
+
+// ErrInternalBadWireType is returned by generated code when an incorrect
+// wire type is encountered. It does not get returned to user code.
+var ErrInternalBadWireType = errors.New("proto: internal error: bad wiretype for oneof")
+
+// DecodeVarint reads a varint-encoded integer from the slice.
+// It returns the integer and the number of bytes consumed, or
+// zero if there is not enough.
+// This is the format for the
+// int32, int64, uint32, uint64, bool, and enum
+// protocol buffer types.
+func DecodeVarint(buf []byte) (x uint64, n int) {
+	for shift := uint(0); shift < 64; shift += 7 {
+		if n >= len(buf) {
+			return 0, 0
+		}
+		b := uint64(buf[n])
+		n++
+		x |= (b & 0x7F) << shift
+		if (b & 0x80) == 0 {
+			return x, n
+		}
+	}
+
+	// The number is too large to represent in a 64-bit value.
+	return 0, 0
+}
+
+func (p *Buffer) decodeVarintSlow() (x uint64, err error) {
+	i := p.index
+	l := len(p.buf)
+
+	for shift := uint(0); shift < 64; shift += 7 {
+		if i >= l {
+			err = io.ErrUnexpectedEOF
+			return
+		}
+		b := p.buf[i]
+		i++
+		x |= (uint64(b) & 0x7F) << shift
+		if b < 0x80 {
+			p.index = i
+			return
+		}
+	}
+
+	// The number is too large to represent in a 64-bit value.
+	err = errOverflow
+	return
+}
+
+// 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 (p *Buffer) DecodeVarint() (x uint64, err error) {
+	i := p.index
+	buf := p.buf
+
+	if i >= len(buf) {
+		return 0, io.ErrUnexpectedEOF
+	} else if buf[i] < 0x80 {
+		p.index++
+		return uint64(buf[i]), nil
+	} else if len(buf)-i < 10 {
+		return p.decodeVarintSlow()
+	}
+
+	var b uint64
+	// we already checked the first byte
+	x = uint64(buf[i]) - 0x80
+	i++
+
+	b = uint64(buf[i])
+	i++
+	x += b << 7
+	if b&0x80 == 0 {
+		goto done
+	}
+	x -= 0x80 << 7
+
+	b = uint64(buf[i])
+	i++
+	x += b << 14
+	if b&0x80 == 0 {
+		goto done
+	}
+	x -= 0x80 << 14
+
+	b = uint64(buf[i])
+	i++
+	x += b << 21
+	if b&0x80 == 0 {
+		goto done
+	}
+	x -= 0x80 << 21
+
+	b = uint64(buf[i])
+	i++
+	x += b << 28
+	if b&0x80 == 0 {
+		goto done
+	}
+	x -= 0x80 << 28
+
+	b = uint64(buf[i])
+	i++
+	x += b << 35
+	if b&0x80 == 0 {
+		goto done
+	}
+	x -= 0x80 << 35
+
+	b = uint64(buf[i])
+	i++
+	x += b << 42
+	if b&0x80 == 0 {
+		goto done
+	}
+	x -= 0x80 << 42
+
+	b = uint64(buf[i])
+	i++
+	x += b << 49
+	if b&0x80 == 0 {
+		goto done
+	}
+	x -= 0x80 << 49
+
+	b = uint64(buf[i])
+	i++
+	x += b << 56
+	if b&0x80 == 0 {
+		goto done
+	}
+	x -= 0x80 << 56
+
+	b = uint64(buf[i])
+	i++
+	x += b << 63
+	if b&0x80 == 0 {
+		goto done
+	}
+	// x -= 0x80 << 63 // Always zero.
+
+	return 0, errOverflow
+
+done:
+	p.index = i
+	return x, nil
+}
+
+// DecodeFixed64 reads a 64-bit integer from the Buffer.
+// This is the format for the
+// fixed64, sfixed64, and double protocol buffer types.
+func (p *Buffer) DecodeFixed64() (x uint64, err error) {
+	// x, err already 0
+	i := p.index + 8
+	if i < 0 || i > len(p.buf) {
+		err = io.ErrUnexpectedEOF
+		return
+	}
+	p.index = i
+
+	x = uint64(p.buf[i-8])
+	x |= uint64(p.buf[i-7]) << 8
+	x |= uint64(p.buf[i-6]) << 16
+	x |= uint64(p.buf[i-5]) << 24
+	x |= uint64(p.buf[i-4]) << 32
+	x |= uint64(p.buf[i-3]) << 40
+	x |= uint64(p.buf[i-2]) << 48
+	x |= uint64(p.buf[i-1]) << 56
+	return
+}
+
+// DecodeFixed32 reads a 32-bit integer from the Buffer.
+// This is the format for the
+// fixed32, sfixed32, and float protocol buffer types.
+func (p *Buffer) DecodeFixed32() (x uint64, err error) {
+	// x, err already 0
+	i := p.index + 4
+	if i < 0 || i > len(p.buf) {
+		err = io.ErrUnexpectedEOF
+		return
+	}
+	p.index = i
+
+	x = uint64(p.buf[i-4])
+	x |= uint64(p.buf[i-3]) << 8
+	x |= uint64(p.buf[i-2]) << 16
+	x |= uint64(p.buf[i-1]) << 24
+	return
+}
+
+// DecodeZigzag64 reads a zigzag-encoded 64-bit integer
+// from the Buffer.
+// This is the format used for the sint64 protocol buffer type.
+func (p *Buffer) DecodeZigzag64() (x uint64, err error) {
+	x, err = p.DecodeVarint()
+	if err != nil {
+		return
+	}
+	x = (x >> 1) ^ uint64((int64(x&1)<<63)>>63)
+	return
+}
+
+// DecodeZigzag32 reads a zigzag-encoded 32-bit integer
+// from  the Buffer.
+// This is the format used for the sint32 protocol buffer type.
+func (p *Buffer) DecodeZigzag32() (x uint64, err error) {
+	x, err = p.DecodeVarint()
+	if err != nil {
+		return
+	}
+	x = uint64((uint32(x) >> 1) ^ uint32((int32(x&1)<<31)>>31))
+	return
+}
+
+// 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 (p *Buffer) DecodeRawBytes(alloc bool) (buf []byte, err error) {
+	n, err := p.DecodeVarint()
+	if err != nil {
+		return nil, err
+	}
+
+	nb := int(n)
+	if nb < 0 {
+		return nil, fmt.Errorf("proto: bad byte length %d", nb)
+	}
+	end := p.index + nb
+	if end < p.index || end > len(p.buf) {
+		return nil, io.ErrUnexpectedEOF
+	}
+
+	if !alloc {
+		// todo: check if can get more uses of alloc=false
+		buf = p.buf[p.index:end]
+		p.index += nb
+		return
+	}
+
+	buf = make([]byte, nb)
+	copy(buf, p.buf[p.index:])
+	p.index += nb
+	return
+}
+
+// DecodeStringBytes reads an encoded string from the Buffer.
+// This is the format used for the proto2 string type.
+func (p *Buffer) DecodeStringBytes() (s string, err error) {
+	buf, err := p.DecodeRawBytes(false)
+	if err != nil {
+		return
+	}
+	return string(buf), nil
+}
+
+// Unmarshaler is the interface representing objects that can
+// unmarshal themselves.  The argument points to data that may be
+// overwritten, so implementations should not keep references to the
+// buffer.
+// Unmarshal implementations should not clear the receiver.
+// Any unmarshaled data should be merged into the receiver.
+// Callers of Unmarshal that do not want to retain existing data
+// should Reset the receiver before calling Unmarshal.
+type Unmarshaler interface {
+	Unmarshal([]byte) error
+}
+
+// newUnmarshaler is the interface representing objects that can
+// unmarshal themselves. The semantics are identical to Unmarshaler.
+//
+// This exists to support protoc-gen-go generated messages.
+// The proto package will stop type-asserting to this interface in the future.
+//
+// DO NOT DEPEND ON THIS.
+type newUnmarshaler interface {
+	XXX_Unmarshal([]byte) error
+}
+
+// Unmarshal parses the protocol buffer representation in buf and places the
+// decoded result in pb.  If the struct underlying pb does not match
+// the data in buf, the results can be unpredictable.
+//
+// Unmarshal resets pb before starting to unmarshal, so any
+// existing data in pb is always removed. Use UnmarshalMerge
+// to preserve and append to existing data.
+func Unmarshal(buf []byte, pb Message) error {
+	pb.Reset()
+	if u, ok := pb.(newUnmarshaler); ok {
+		return u.XXX_Unmarshal(buf)
+	}
+	if u, ok := pb.(Unmarshaler); ok {
+		return u.Unmarshal(buf)
+	}
+	return NewBuffer(buf).Unmarshal(pb)
+}
+
+// UnmarshalMerge parses the protocol buffer representation in buf and
+// writes the decoded result to pb.  If the struct underlying pb does not match
+// the data in buf, the results can be unpredictable.
+//
+// UnmarshalMerge merges into existing data in pb.
+// Most code should use Unmarshal instead.
+func UnmarshalMerge(buf []byte, pb Message) error {
+	if u, ok := pb.(newUnmarshaler); ok {
+		return u.XXX_Unmarshal(buf)
+	}
+	if u, ok := pb.(Unmarshaler); ok {
+		// NOTE: The history of proto have unfortunately been inconsistent
+		// whether Unmarshaler should or should not implicitly clear itself.
+		// Some implementations do, most do not.
+		// Thus, calling this here may or may not do what people want.
+		//
+		// See https://github.com/golang/protobuf/issues/424
+		return u.Unmarshal(buf)
+	}
+	return NewBuffer(buf).Unmarshal(pb)
+}
+
+// DecodeMessage reads a count-delimited message from the Buffer.
+func (p *Buffer) DecodeMessage(pb Message) error {
+	enc, err := p.DecodeRawBytes(false)
+	if err != nil {
+		return err
+	}
+	return NewBuffer(enc).Unmarshal(pb)
+}
+
+// DecodeGroup reads a tag-delimited group from the Buffer.
+// StartGroup tag is already consumed. This function consumes
+// EndGroup tag.
+func (p *Buffer) DecodeGroup(pb Message) error {
+	b := p.buf[p.index:]
+	x, y := findEndGroup(b)
+	if x < 0 {
+		return io.ErrUnexpectedEOF
+	}
+	err := Unmarshal(b[:x], pb)
+	p.index += y
+	return err
+}
+
+// Unmarshal parses the protocol buffer representation in the
+// Buffer and places the decoded result in pb.  If the struct
+// underlying pb does not match the data in the buffer, the results can be
+// unpredictable.
+//
+// Unlike proto.Unmarshal, this does not reset pb before starting to unmarshal.
+func (p *Buffer) Unmarshal(pb Message) error {
+	// If the object can unmarshal itself, let it.
+	if u, ok := pb.(newUnmarshaler); ok {
+		err := u.XXX_Unmarshal(p.buf[p.index:])
+		p.index = len(p.buf)
+		return err
+	}
+	if u, ok := pb.(Unmarshaler); ok {
+		// NOTE: The history of proto have unfortunately been inconsistent
+		// whether Unmarshaler should or should not implicitly clear itself.
+		// Some implementations do, most do not.
+		// Thus, calling this here may or may not do what people want.
+		//
+		// See https://github.com/golang/protobuf/issues/424
+		err := u.Unmarshal(p.buf[p.index:])
+		p.index = len(p.buf)
+		return err
+	}
+
+	// Slow workaround for messages that aren't Unmarshalers.
+	// This includes some hand-coded .pb.go files and
+	// bootstrap protos.
+	// TODO: fix all of those and then add Unmarshal to
+	// the Message interface. Then:
+	// The cast above and code below can be deleted.
+	// The old unmarshaler can be deleted.
+	// Clients can call Unmarshal directly (can already do that, actually).
+	var info InternalMessageInfo
+	err := info.Unmarshal(pb, p.buf[p.index:])
+	p.index = len(p.buf)
+	return err
+}
diff --git a/vendor/github.com/golang/protobuf/proto/discard.go b/vendor/github.com/golang/protobuf/proto/discard.go
new file mode 100644
index 0000000..dea2617
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/discard.go
@@ -0,0 +1,350 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2017 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package proto
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+	"sync"
+	"sync/atomic"
+)
+
+type generatedDiscarder interface {
+	XXX_DiscardUnknown()
+}
+
+// DiscardUnknown recursively discards all unknown fields from this message
+// and all embedded messages.
+//
+// When unmarshaling a message with unrecognized fields, the tags and values
+// of such fields are preserved in the Message. This allows a later call to
+// marshal to be able to produce a message that continues to have those
+// unrecognized fields. To avoid this, DiscardUnknown is used to
+// explicitly clear the unknown fields after unmarshaling.
+//
+// For proto2 messages, the unknown fields of message extensions are only
+// discarded from messages that have been accessed via GetExtension.
+func DiscardUnknown(m Message) {
+	if m, ok := m.(generatedDiscarder); ok {
+		m.XXX_DiscardUnknown()
+		return
+	}
+	// TODO: Dynamically populate a InternalMessageInfo for legacy messages,
+	// but the master branch has no implementation for InternalMessageInfo,
+	// so it would be more work to replicate that approach.
+	discardLegacy(m)
+}
+
+// DiscardUnknown recursively discards all unknown fields.
+func (a *InternalMessageInfo) DiscardUnknown(m Message) {
+	di := atomicLoadDiscardInfo(&a.discard)
+	if di == nil {
+		di = getDiscardInfo(reflect.TypeOf(m).Elem())
+		atomicStoreDiscardInfo(&a.discard, di)
+	}
+	di.discard(toPointer(&m))
+}
+
+type discardInfo struct {
+	typ reflect.Type
+
+	initialized int32 // 0: only typ is valid, 1: everything is valid
+	lock        sync.Mutex
+
+	fields       []discardFieldInfo
+	unrecognized field
+}
+
+type discardFieldInfo struct {
+	field   field // Offset of field, guaranteed to be valid
+	discard func(src pointer)
+}
+
+var (
+	discardInfoMap  = map[reflect.Type]*discardInfo{}
+	discardInfoLock sync.Mutex
+)
+
+func getDiscardInfo(t reflect.Type) *discardInfo {
+	discardInfoLock.Lock()
+	defer discardInfoLock.Unlock()
+	di := discardInfoMap[t]
+	if di == nil {
+		di = &discardInfo{typ: t}
+		discardInfoMap[t] = di
+	}
+	return di
+}
+
+func (di *discardInfo) discard(src pointer) {
+	if src.isNil() {
+		return // Nothing to do.
+	}
+
+	if atomic.LoadInt32(&di.initialized) == 0 {
+		di.computeDiscardInfo()
+	}
+
+	for _, fi := range di.fields {
+		sfp := src.offset(fi.field)
+		fi.discard(sfp)
+	}
+
+	// For proto2 messages, only discard unknown fields in message extensions
+	// that have been accessed via GetExtension.
+	if em, err := extendable(src.asPointerTo(di.typ).Interface()); err == nil {
+		// Ignore lock since DiscardUnknown is not concurrency safe.
+		emm, _ := em.extensionsRead()
+		for _, mx := range emm {
+			if m, ok := mx.value.(Message); ok {
+				DiscardUnknown(m)
+			}
+		}
+	}
+
+	if di.unrecognized.IsValid() {
+		*src.offset(di.unrecognized).toBytes() = nil
+	}
+}
+
+func (di *discardInfo) computeDiscardInfo() {
+	di.lock.Lock()
+	defer di.lock.Unlock()
+	if di.initialized != 0 {
+		return
+	}
+	t := di.typ
+	n := t.NumField()
+
+	for i := 0; i < n; i++ {
+		f := t.Field(i)
+		if strings.HasPrefix(f.Name, "XXX_") {
+			continue
+		}
+
+		dfi := discardFieldInfo{field: toField(&f)}
+		tf := f.Type
+
+		// Unwrap tf to get its most basic type.
+		var isPointer, isSlice bool
+		if tf.Kind() == reflect.Slice && tf.Elem().Kind() != reflect.Uint8 {
+			isSlice = true
+			tf = tf.Elem()
+		}
+		if tf.Kind() == reflect.Ptr {
+			isPointer = true
+			tf = tf.Elem()
+		}
+		if isPointer && isSlice && tf.Kind() != reflect.Struct {
+			panic(fmt.Sprintf("%v.%s cannot be a slice of pointers to primitive types", t, f.Name))
+		}
+
+		switch tf.Kind() {
+		case reflect.Struct:
+			switch {
+			case !isPointer:
+				panic(fmt.Sprintf("%v.%s cannot be a direct struct value", t, f.Name))
+			case isSlice: // E.g., []*pb.T
+				di := getDiscardInfo(tf)
+				dfi.discard = func(src pointer) {
+					sps := src.getPointerSlice()
+					for _, sp := range sps {
+						if !sp.isNil() {
+							di.discard(sp)
+						}
+					}
+				}
+			default: // E.g., *pb.T
+				di := getDiscardInfo(tf)
+				dfi.discard = func(src pointer) {
+					sp := src.getPointer()
+					if !sp.isNil() {
+						di.discard(sp)
+					}
+				}
+			}
+		case reflect.Map:
+			switch {
+			case isPointer || isSlice:
+				panic(fmt.Sprintf("%v.%s cannot be a pointer to a map or a slice of map values", t, f.Name))
+			default: // E.g., map[K]V
+				if tf.Elem().Kind() == reflect.Ptr { // Proto struct (e.g., *T)
+					dfi.discard = func(src pointer) {
+						sm := src.asPointerTo(tf).Elem()
+						if sm.Len() == 0 {
+							return
+						}
+						for _, key := range sm.MapKeys() {
+							val := sm.MapIndex(key)
+							DiscardUnknown(val.Interface().(Message))
+						}
+					}
+				} else {
+					dfi.discard = func(pointer) {} // Noop
+				}
+			}
+		case reflect.Interface:
+			// Must be oneof field.
+			switch {
+			case isPointer || isSlice:
+				panic(fmt.Sprintf("%v.%s cannot be a pointer to a interface or a slice of interface values", t, f.Name))
+			default: // E.g., interface{}
+				// TODO: Make this faster?
+				dfi.discard = func(src pointer) {
+					su := src.asPointerTo(tf).Elem()
+					if !su.IsNil() {
+						sv := su.Elem().Elem().Field(0)
+						if sv.Kind() == reflect.Ptr && sv.IsNil() {
+							return
+						}
+						switch sv.Type().Kind() {
+						case reflect.Ptr: // Proto struct (e.g., *T)
+							DiscardUnknown(sv.Interface().(Message))
+						}
+					}
+				}
+			}
+		default:
+			continue
+		}
+		di.fields = append(di.fields, dfi)
+	}
+
+	di.unrecognized = invalidField
+	if f, ok := t.FieldByName("XXX_unrecognized"); ok {
+		if f.Type != reflect.TypeOf([]byte{}) {
+			panic("expected XXX_unrecognized to be of type []byte")
+		}
+		di.unrecognized = toField(&f)
+	}
+
+	atomic.StoreInt32(&di.initialized, 1)
+}
+
+func discardLegacy(m Message) {
+	v := reflect.ValueOf(m)
+	if v.Kind() != reflect.Ptr || v.IsNil() {
+		return
+	}
+	v = v.Elem()
+	if v.Kind() != reflect.Struct {
+		return
+	}
+	t := v.Type()
+
+	for i := 0; i < v.NumField(); i++ {
+		f := t.Field(i)
+		if strings.HasPrefix(f.Name, "XXX_") {
+			continue
+		}
+		vf := v.Field(i)
+		tf := f.Type
+
+		// Unwrap tf to get its most basic type.
+		var isPointer, isSlice bool
+		if tf.Kind() == reflect.Slice && tf.Elem().Kind() != reflect.Uint8 {
+			isSlice = true
+			tf = tf.Elem()
+		}
+		if tf.Kind() == reflect.Ptr {
+			isPointer = true
+			tf = tf.Elem()
+		}
+		if isPointer && isSlice && tf.Kind() != reflect.Struct {
+			panic(fmt.Sprintf("%T.%s cannot be a slice of pointers to primitive types", m, f.Name))
+		}
+
+		switch tf.Kind() {
+		case reflect.Struct:
+			switch {
+			case !isPointer:
+				panic(fmt.Sprintf("%T.%s cannot be a direct struct value", m, f.Name))
+			case isSlice: // E.g., []*pb.T
+				for j := 0; j < vf.Len(); j++ {
+					discardLegacy(vf.Index(j).Interface().(Message))
+				}
+			default: // E.g., *pb.T
+				discardLegacy(vf.Interface().(Message))
+			}
+		case reflect.Map:
+			switch {
+			case isPointer || isSlice:
+				panic(fmt.Sprintf("%T.%s cannot be a pointer to a map or a slice of map values", m, f.Name))
+			default: // E.g., map[K]V
+				tv := vf.Type().Elem()
+				if tv.Kind() == reflect.Ptr && tv.Implements(protoMessageType) { // Proto struct (e.g., *T)
+					for _, key := range vf.MapKeys() {
+						val := vf.MapIndex(key)
+						discardLegacy(val.Interface().(Message))
+					}
+				}
+			}
+		case reflect.Interface:
+			// Must be oneof field.
+			switch {
+			case isPointer || isSlice:
+				panic(fmt.Sprintf("%T.%s cannot be a pointer to a interface or a slice of interface values", m, f.Name))
+			default: // E.g., test_proto.isCommunique_Union interface
+				if !vf.IsNil() && f.Tag.Get("protobuf_oneof") != "" {
+					vf = vf.Elem() // E.g., *test_proto.Communique_Msg
+					if !vf.IsNil() {
+						vf = vf.Elem()   // E.g., test_proto.Communique_Msg
+						vf = vf.Field(0) // E.g., Proto struct (e.g., *T) or primitive value
+						if vf.Kind() == reflect.Ptr {
+							discardLegacy(vf.Interface().(Message))
+						}
+					}
+				}
+			}
+		}
+	}
+
+	if vf := v.FieldByName("XXX_unrecognized"); vf.IsValid() {
+		if vf.Type() != reflect.TypeOf([]byte{}) {
+			panic("expected XXX_unrecognized to be of type []byte")
+		}
+		vf.Set(reflect.ValueOf([]byte(nil)))
+	}
+
+	// For proto2 messages, only discard unknown fields in message extensions
+	// that have been accessed via GetExtension.
+	if em, err := extendable(m); err == nil {
+		// Ignore lock since discardLegacy is not concurrency safe.
+		emm, _ := em.extensionsRead()
+		for _, mx := range emm {
+			if m, ok := mx.value.(Message); ok {
+				discardLegacy(m)
+			}
+		}
+	}
+}
diff --git a/vendor/github.com/golang/protobuf/proto/encode.go b/vendor/github.com/golang/protobuf/proto/encode.go
new file mode 100644
index 0000000..3abfed2
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/encode.go
@@ -0,0 +1,203 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2010 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package proto
+
+/*
+ * Routines for encoding data into the wire format for protocol buffers.
+ */
+
+import (
+	"errors"
+	"reflect"
+)
+
+var (
+	// errRepeatedHasNil is the error returned if Marshal is called with
+	// a struct with a repeated field containing a nil element.
+	errRepeatedHasNil = errors.New("proto: repeated field has nil element")
+
+	// errOneofHasNil is the error returned if Marshal is called with
+	// a struct with a oneof field containing a nil element.
+	errOneofHasNil = errors.New("proto: oneof field has nil value")
+
+	// ErrNil is the error returned if Marshal is called with nil.
+	ErrNil = errors.New("proto: Marshal called with nil")
+
+	// ErrTooLarge is the error returned if Marshal is called with a
+	// message that encodes to >2GB.
+	ErrTooLarge = errors.New("proto: message encodes to over 2 GB")
+)
+
+// The fundamental encoders that put bytes on the wire.
+// Those that take integer types all accept uint64 and are
+// therefore of type valueEncoder.
+
+const maxVarintBytes = 10 // maximum length of a varint
+
+// EncodeVarint returns the varint encoding of x.
+// This is the format for the
+// int32, int64, uint32, uint64, bool, and enum
+// protocol buffer types.
+// Not used by the package itself, but helpful to clients
+// wishing to use the same encoding.
+func EncodeVarint(x uint64) []byte {
+	var buf [maxVarintBytes]byte
+	var n int
+	for n = 0; x > 127; n++ {
+		buf[n] = 0x80 | uint8(x&0x7F)
+		x >>= 7
+	}
+	buf[n] = uint8(x)
+	n++
+	return buf[0:n]
+}
+
+// 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 (p *Buffer) EncodeVarint(x uint64) error {
+	for x >= 1<<7 {
+		p.buf = append(p.buf, uint8(x&0x7f|0x80))
+		x >>= 7
+	}
+	p.buf = append(p.buf, uint8(x))
+	return nil
+}
+
+// SizeVarint returns the varint encoding size of an integer.
+func SizeVarint(x uint64) int {
+	switch {
+	case x < 1<<7:
+		return 1
+	case x < 1<<14:
+		return 2
+	case x < 1<<21:
+		return 3
+	case x < 1<<28:
+		return 4
+	case x < 1<<35:
+		return 5
+	case x < 1<<42:
+		return 6
+	case x < 1<<49:
+		return 7
+	case x < 1<<56:
+		return 8
+	case x < 1<<63:
+		return 9
+	}
+	return 10
+}
+
+// EncodeFixed64 writes a 64-bit integer to the Buffer.
+// This is the format for the
+// fixed64, sfixed64, and double protocol buffer types.
+func (p *Buffer) EncodeFixed64(x uint64) error {
+	p.buf = append(p.buf,
+		uint8(x),
+		uint8(x>>8),
+		uint8(x>>16),
+		uint8(x>>24),
+		uint8(x>>32),
+		uint8(x>>40),
+		uint8(x>>48),
+		uint8(x>>56))
+	return nil
+}
+
+// EncodeFixed32 writes a 32-bit integer to the Buffer.
+// This is the format for the
+// fixed32, sfixed32, and float protocol buffer types.
+func (p *Buffer) EncodeFixed32(x uint64) error {
+	p.buf = append(p.buf,
+		uint8(x),
+		uint8(x>>8),
+		uint8(x>>16),
+		uint8(x>>24))
+	return nil
+}
+
+// EncodeZigzag64 writes a zigzag-encoded 64-bit integer
+// to the Buffer.
+// This is the format used for the sint64 protocol buffer type.
+func (p *Buffer) EncodeZigzag64(x uint64) error {
+	// use signed number to get arithmetic right shift.
+	return p.EncodeVarint(uint64((x << 1) ^ uint64((int64(x) >> 63))))
+}
+
+// EncodeZigzag32 writes a zigzag-encoded 32-bit integer
+// to the Buffer.
+// This is the format used for the sint32 protocol buffer type.
+func (p *Buffer) EncodeZigzag32(x uint64) error {
+	// use signed number to get arithmetic right shift.
+	return p.EncodeVarint(uint64((uint32(x) << 1) ^ uint32((int32(x) >> 31))))
+}
+
+// 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 (p *Buffer) EncodeRawBytes(b []byte) error {
+	p.EncodeVarint(uint64(len(b)))
+	p.buf = append(p.buf, b...)
+	return nil
+}
+
+// EncodeStringBytes writes an encoded string to the Buffer.
+// This is the format used for the proto2 string type.
+func (p *Buffer) EncodeStringBytes(s string) error {
+	p.EncodeVarint(uint64(len(s)))
+	p.buf = append(p.buf, s...)
+	return nil
+}
+
+// Marshaler is the interface representing objects that can marshal themselves.
+type Marshaler interface {
+	Marshal() ([]byte, error)
+}
+
+// EncodeMessage writes the protocol buffer to the Buffer,
+// prefixed by a varint-encoded length.
+func (p *Buffer) EncodeMessage(pb Message) error {
+	siz := Size(pb)
+	p.EncodeVarint(uint64(siz))
+	return p.Marshal(pb)
+}
+
+// All protocol buffer fields are nillable, but be careful.
+func isNil(v reflect.Value) bool {
+	switch v.Kind() {
+	case reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice:
+		return v.IsNil()
+	}
+	return false
+}
diff --git a/vendor/github.com/golang/protobuf/proto/equal.go b/vendor/github.com/golang/protobuf/proto/equal.go
new file mode 100644
index 0000000..d4db5a1
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/equal.go
@@ -0,0 +1,300 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2011 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Protocol buffer comparison.
+
+package proto
+
+import (
+	"bytes"
+	"log"
+	"reflect"
+	"strings"
+)
+
+/*
+Equal returns true iff protocol buffers a and b are equal.
+The arguments must both be pointers to protocol buffer structs.
+
+Equality is defined in this way:
+  - Two messages are equal iff they are the same type,
+    corresponding fields are equal, unknown field sets
+    are equal, and extensions sets are equal.
+  - Two set scalar fields are equal iff their values are equal.
+    If the fields are of a floating-point type, remember that
+    NaN != x for all x, including NaN. If the message is defined
+    in a proto3 .proto file, fields are not "set"; specifically,
+    zero length proto3 "bytes" fields are equal (nil == {}).
+  - Two repeated fields are equal iff their lengths are the same,
+    and their corresponding elements are equal. Note a "bytes" field,
+    although represented by []byte, is not a repeated field and the
+    rule for the scalar fields described above applies.
+  - Two unset fields are equal.
+  - Two unknown field sets are equal if their current
+    encoded state is equal.
+  - Two extension sets are equal iff they have corresponding
+    elements that are pairwise equal.
+  - Two map fields are equal iff their lengths are the same,
+    and they contain the same set of elements. Zero-length map
+    fields are equal.
+  - Every other combination of things are not equal.
+
+The return value is undefined if a and b are not protocol buffers.
+*/
+func Equal(a, b Message) bool {
+	if a == nil || b == nil {
+		return a == b
+	}
+	v1, v2 := reflect.ValueOf(a), reflect.ValueOf(b)
+	if v1.Type() != v2.Type() {
+		return false
+	}
+	if v1.Kind() == reflect.Ptr {
+		if v1.IsNil() {
+			return v2.IsNil()
+		}
+		if v2.IsNil() {
+			return false
+		}
+		v1, v2 = v1.Elem(), v2.Elem()
+	}
+	if v1.Kind() != reflect.Struct {
+		return false
+	}
+	return equalStruct(v1, v2)
+}
+
+// v1 and v2 are known to have the same type.
+func equalStruct(v1, v2 reflect.Value) bool {
+	sprop := GetProperties(v1.Type())
+	for i := 0; i < v1.NumField(); i++ {
+		f := v1.Type().Field(i)
+		if strings.HasPrefix(f.Name, "XXX_") {
+			continue
+		}
+		f1, f2 := v1.Field(i), v2.Field(i)
+		if f.Type.Kind() == reflect.Ptr {
+			if n1, n2 := f1.IsNil(), f2.IsNil(); n1 && n2 {
+				// both unset
+				continue
+			} else if n1 != n2 {
+				// set/unset mismatch
+				return false
+			}
+			f1, f2 = f1.Elem(), f2.Elem()
+		}
+		if !equalAny(f1, f2, sprop.Prop[i]) {
+			return false
+		}
+	}
+
+	if em1 := v1.FieldByName("XXX_InternalExtensions"); em1.IsValid() {
+		em2 := v2.FieldByName("XXX_InternalExtensions")
+		if !equalExtensions(v1.Type(), em1.Interface().(XXX_InternalExtensions), em2.Interface().(XXX_InternalExtensions)) {
+			return false
+		}
+	}
+
+	if em1 := v1.FieldByName("XXX_extensions"); em1.IsValid() {
+		em2 := v2.FieldByName("XXX_extensions")
+		if !equalExtMap(v1.Type(), em1.Interface().(map[int32]Extension), em2.Interface().(map[int32]Extension)) {
+			return false
+		}
+	}
+
+	uf := v1.FieldByName("XXX_unrecognized")
+	if !uf.IsValid() {
+		return true
+	}
+
+	u1 := uf.Bytes()
+	u2 := v2.FieldByName("XXX_unrecognized").Bytes()
+	return bytes.Equal(u1, u2)
+}
+
+// v1 and v2 are known to have the same type.
+// prop may be nil.
+func equalAny(v1, v2 reflect.Value, prop *Properties) bool {
+	if v1.Type() == protoMessageType {
+		m1, _ := v1.Interface().(Message)
+		m2, _ := v2.Interface().(Message)
+		return Equal(m1, m2)
+	}
+	switch v1.Kind() {
+	case reflect.Bool:
+		return v1.Bool() == v2.Bool()
+	case reflect.Float32, reflect.Float64:
+		return v1.Float() == v2.Float()
+	case reflect.Int32, reflect.Int64:
+		return v1.Int() == v2.Int()
+	case reflect.Interface:
+		// Probably a oneof field; compare the inner values.
+		n1, n2 := v1.IsNil(), v2.IsNil()
+		if n1 || n2 {
+			return n1 == n2
+		}
+		e1, e2 := v1.Elem(), v2.Elem()
+		if e1.Type() != e2.Type() {
+			return false
+		}
+		return equalAny(e1, e2, nil)
+	case reflect.Map:
+		if v1.Len() != v2.Len() {
+			return false
+		}
+		for _, key := range v1.MapKeys() {
+			val2 := v2.MapIndex(key)
+			if !val2.IsValid() {
+				// This key was not found in the second map.
+				return false
+			}
+			if !equalAny(v1.MapIndex(key), val2, nil) {
+				return false
+			}
+		}
+		return true
+	case reflect.Ptr:
+		// Maps may have nil values in them, so check for nil.
+		if v1.IsNil() && v2.IsNil() {
+			return true
+		}
+		if v1.IsNil() != v2.IsNil() {
+			return false
+		}
+		return equalAny(v1.Elem(), v2.Elem(), prop)
+	case reflect.Slice:
+		if v1.Type().Elem().Kind() == reflect.Uint8 {
+			// short circuit: []byte
+
+			// Edge case: if this is in a proto3 message, a zero length
+			// bytes field is considered the zero value.
+			if prop != nil && prop.proto3 && v1.Len() == 0 && v2.Len() == 0 {
+				return true
+			}
+			if v1.IsNil() != v2.IsNil() {
+				return false
+			}
+			return bytes.Equal(v1.Interface().([]byte), v2.Interface().([]byte))
+		}
+
+		if v1.Len() != v2.Len() {
+			return false
+		}
+		for i := 0; i < v1.Len(); i++ {
+			if !equalAny(v1.Index(i), v2.Index(i), prop) {
+				return false
+			}
+		}
+		return true
+	case reflect.String:
+		return v1.Interface().(string) == v2.Interface().(string)
+	case reflect.Struct:
+		return equalStruct(v1, v2)
+	case reflect.Uint32, reflect.Uint64:
+		return v1.Uint() == v2.Uint()
+	}
+
+	// unknown type, so not a protocol buffer
+	log.Printf("proto: don't know how to compare %v", v1)
+	return false
+}
+
+// base is the struct type that the extensions are based on.
+// x1 and x2 are InternalExtensions.
+func equalExtensions(base reflect.Type, x1, x2 XXX_InternalExtensions) bool {
+	em1, _ := x1.extensionsRead()
+	em2, _ := x2.extensionsRead()
+	return equalExtMap(base, em1, em2)
+}
+
+func equalExtMap(base reflect.Type, em1, em2 map[int32]Extension) bool {
+	if len(em1) != len(em2) {
+		return false
+	}
+
+	for extNum, e1 := range em1 {
+		e2, ok := em2[extNum]
+		if !ok {
+			return false
+		}
+
+		m1, m2 := e1.value, e2.value
+
+		if m1 == nil && m2 == nil {
+			// Both have only encoded form.
+			if bytes.Equal(e1.enc, e2.enc) {
+				continue
+			}
+			// The bytes are different, but the extensions might still be
+			// equal. We need to decode them to compare.
+		}
+
+		if m1 != nil && m2 != nil {
+			// Both are unencoded.
+			if !equalAny(reflect.ValueOf(m1), reflect.ValueOf(m2), nil) {
+				return false
+			}
+			continue
+		}
+
+		// At least one is encoded. To do a semantically correct comparison
+		// we need to unmarshal them first.
+		var desc *ExtensionDesc
+		if m := extensionMaps[base]; m != nil {
+			desc = m[extNum]
+		}
+		if desc == nil {
+			// If both have only encoded form and the bytes are the same,
+			// it is handled above. We get here when the bytes are different.
+			// We don't know how to decode it, so just compare them as byte
+			// slices.
+			log.Printf("proto: don't know how to compare extension %d of %v", extNum, base)
+			return false
+		}
+		var err error
+		if m1 == nil {
+			m1, err = decodeExtension(e1.enc, desc)
+		}
+		if m2 == nil && err == nil {
+			m2, err = decodeExtension(e2.enc, desc)
+		}
+		if err != nil {
+			// The encoded form is invalid.
+			log.Printf("proto: badly encoded extension %d of %v: %v", extNum, base, err)
+			return false
+		}
+		if !equalAny(reflect.ValueOf(m1), reflect.ValueOf(m2), nil) {
+			return false
+		}
+	}
+
+	return true
+}
diff --git a/vendor/github.com/golang/protobuf/proto/extensions.go b/vendor/github.com/golang/protobuf/proto/extensions.go
new file mode 100644
index 0000000..816a3b9
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/extensions.go
@@ -0,0 +1,543 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2010 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package proto
+
+/*
+ * Types and routines for supporting protocol buffer extensions.
+ */
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"reflect"
+	"strconv"
+	"sync"
+)
+
+// ErrMissingExtension is the error returned by GetExtension if the named extension is not in the message.
+var ErrMissingExtension = errors.New("proto: missing extension")
+
+// ExtensionRange represents a range of message extensions for a protocol buffer.
+// Used in code generated by the protocol compiler.
+type ExtensionRange struct {
+	Start, End int32 // both inclusive
+}
+
+// extendableProto is an interface implemented by any protocol buffer generated by the current
+// proto compiler that may be extended.
+type extendableProto interface {
+	Message
+	ExtensionRangeArray() []ExtensionRange
+	extensionsWrite() map[int32]Extension
+	extensionsRead() (map[int32]Extension, sync.Locker)
+}
+
+// extendableProtoV1 is an interface implemented by a protocol buffer generated by the previous
+// version of the proto compiler that may be extended.
+type extendableProtoV1 interface {
+	Message
+	ExtensionRangeArray() []ExtensionRange
+	ExtensionMap() map[int32]Extension
+}
+
+// extensionAdapter is a wrapper around extendableProtoV1 that implements extendableProto.
+type extensionAdapter struct {
+	extendableProtoV1
+}
+
+func (e extensionAdapter) extensionsWrite() map[int32]Extension {
+	return e.ExtensionMap()
+}
+
+func (e extensionAdapter) extensionsRead() (map[int32]Extension, sync.Locker) {
+	return e.ExtensionMap(), notLocker{}
+}
+
+// notLocker is a sync.Locker whose Lock and Unlock methods are nops.
+type notLocker struct{}
+
+func (n notLocker) Lock()   {}
+func (n notLocker) Unlock() {}
+
+// extendable returns the extendableProto interface for the given generated proto message.
+// If the proto message has the old extension format, it returns a wrapper that implements
+// the extendableProto interface.
+func extendable(p interface{}) (extendableProto, error) {
+	switch p := p.(type) {
+	case extendableProto:
+		if isNilPtr(p) {
+			return nil, fmt.Errorf("proto: nil %T is not extendable", p)
+		}
+		return p, nil
+	case extendableProtoV1:
+		if isNilPtr(p) {
+			return nil, fmt.Errorf("proto: nil %T is not extendable", p)
+		}
+		return extensionAdapter{p}, nil
+	}
+	// Don't allocate a specific error containing %T:
+	// this is the hot path for Clone and MarshalText.
+	return nil, errNotExtendable
+}
+
+var errNotExtendable = errors.New("proto: not an extendable proto.Message")
+
+func isNilPtr(x interface{}) bool {
+	v := reflect.ValueOf(x)
+	return v.Kind() == reflect.Ptr && v.IsNil()
+}
+
+// XXX_InternalExtensions is an internal representation of proto extensions.
+//
+// Each generated message struct type embeds an anonymous XXX_InternalExtensions field,
+// thus gaining the unexported 'extensions' method, which can be called only from the proto package.
+//
+// The methods of XXX_InternalExtensions are not concurrency safe in general,
+// but calls to logically read-only methods such as has and get may be executed concurrently.
+type XXX_InternalExtensions struct {
+	// The struct must be indirect so that if a user inadvertently copies a
+	// generated message and its embedded XXX_InternalExtensions, they
+	// avoid the mayhem of a copied mutex.
+	//
+	// The mutex serializes all logically read-only operations to p.extensionMap.
+	// It is up to the client to ensure that write operations to p.extensionMap are
+	// mutually exclusive with other accesses.
+	p *struct {
+		mu           sync.Mutex
+		extensionMap map[int32]Extension
+	}
+}
+
+// extensionsWrite returns the extension map, creating it on first use.
+func (e *XXX_InternalExtensions) extensionsWrite() map[int32]Extension {
+	if e.p == nil {
+		e.p = new(struct {
+			mu           sync.Mutex
+			extensionMap map[int32]Extension
+		})
+		e.p.extensionMap = make(map[int32]Extension)
+	}
+	return e.p.extensionMap
+}
+
+// extensionsRead returns the extensions map for read-only use.  It may be nil.
+// The caller must hold the returned mutex's lock when accessing Elements within the map.
+func (e *XXX_InternalExtensions) extensionsRead() (map[int32]Extension, sync.Locker) {
+	if e.p == nil {
+		return nil, nil
+	}
+	return e.p.extensionMap, &e.p.mu
+}
+
+// ExtensionDesc represents an extension specification.
+// Used in generated code from the protocol compiler.
+type ExtensionDesc struct {
+	ExtendedType  Message     // nil pointer to the type that is being extended
+	ExtensionType interface{} // nil pointer to the extension type
+	Field         int32       // field number
+	Name          string      // fully-qualified name of extension, for text formatting
+	Tag           string      // protobuf tag style
+	Filename      string      // name of the file in which the extension is defined
+}
+
+func (ed *ExtensionDesc) repeated() bool {
+	t := reflect.TypeOf(ed.ExtensionType)
+	return t.Kind() == reflect.Slice && t.Elem().Kind() != reflect.Uint8
+}
+
+// Extension represents an extension in a message.
+type Extension struct {
+	// When an extension is stored in a message using SetExtension
+	// only desc and value are set. When the message is marshaled
+	// enc will be set to the encoded form of the message.
+	//
+	// When a message is unmarshaled and contains extensions, each
+	// extension will have only enc set. When such an extension is
+	// accessed using GetExtension (or GetExtensions) desc and value
+	// will be set.
+	desc  *ExtensionDesc
+	value interface{}
+	enc   []byte
+}
+
+// SetRawExtension is for testing only.
+func SetRawExtension(base Message, id int32, b []byte) {
+	epb, err := extendable(base)
+	if err != nil {
+		return
+	}
+	extmap := epb.extensionsWrite()
+	extmap[id] = Extension{enc: b}
+}
+
+// isExtensionField returns true iff the given field number is in an extension range.
+func isExtensionField(pb extendableProto, field int32) bool {
+	for _, er := range pb.ExtensionRangeArray() {
+		if er.Start <= field && field <= er.End {
+			return true
+		}
+	}
+	return false
+}
+
+// checkExtensionTypes checks that the given extension is valid for pb.
+func checkExtensionTypes(pb extendableProto, extension *ExtensionDesc) error {
+	var pbi interface{} = pb
+	// Check the extended type.
+	if ea, ok := pbi.(extensionAdapter); ok {
+		pbi = ea.extendableProtoV1
+	}
+	if a, b := reflect.TypeOf(pbi), reflect.TypeOf(extension.ExtendedType); a != b {
+		return fmt.Errorf("proto: bad extended type; %v does not extend %v", b, a)
+	}
+	// Check the range.
+	if !isExtensionField(pb, extension.Field) {
+		return errors.New("proto: bad extension number; not in declared ranges")
+	}
+	return nil
+}
+
+// extPropKey is sufficient to uniquely identify an extension.
+type extPropKey struct {
+	base  reflect.Type
+	field int32
+}
+
+var extProp = struct {
+	sync.RWMutex
+	m map[extPropKey]*Properties
+}{
+	m: make(map[extPropKey]*Properties),
+}
+
+func extensionProperties(ed *ExtensionDesc) *Properties {
+	key := extPropKey{base: reflect.TypeOf(ed.ExtendedType), field: ed.Field}
+
+	extProp.RLock()
+	if prop, ok := extProp.m[key]; ok {
+		extProp.RUnlock()
+		return prop
+	}
+	extProp.RUnlock()
+
+	extProp.Lock()
+	defer extProp.Unlock()
+	// Check again.
+	if prop, ok := extProp.m[key]; ok {
+		return prop
+	}
+
+	prop := new(Properties)
+	prop.Init(reflect.TypeOf(ed.ExtensionType), "unknown_name", ed.Tag, nil)
+	extProp.m[key] = prop
+	return prop
+}
+
+// HasExtension returns whether the given extension is present in pb.
+func HasExtension(pb Message, extension *ExtensionDesc) bool {
+	// TODO: Check types, field numbers, etc.?
+	epb, err := extendable(pb)
+	if err != nil {
+		return false
+	}
+	extmap, mu := epb.extensionsRead()
+	if extmap == nil {
+		return false
+	}
+	mu.Lock()
+	_, ok := extmap[extension.Field]
+	mu.Unlock()
+	return ok
+}
+
+// ClearExtension removes the given extension from pb.
+func ClearExtension(pb Message, extension *ExtensionDesc) {
+	epb, err := extendable(pb)
+	if err != nil {
+		return
+	}
+	// TODO: Check types, field numbers, etc.?
+	extmap := epb.extensionsWrite()
+	delete(extmap, extension.Field)
+}
+
+// GetExtension retrieves a proto2 extended field from pb.
+//
+// If the descriptor is type complete (i.e., ExtensionDesc.ExtensionType is non-nil),
+// then GetExtension parses the encoded field and returns a Go value of the specified type.
+// If the field is not present, then the default value is returned (if one is specified),
+// otherwise ErrMissingExtension is reported.
+//
+// If the descriptor is not type complete (i.e., ExtensionDesc.ExtensionType is nil),
+// then GetExtension returns the raw encoded bytes of the field extension.
+func GetExtension(pb Message, extension *ExtensionDesc) (interface{}, error) {
+	epb, err := extendable(pb)
+	if err != nil {
+		return nil, err
+	}
+
+	if extension.ExtendedType != nil {
+		// can only check type if this is a complete descriptor
+		if err := checkExtensionTypes(epb, extension); err != nil {
+			return nil, err
+		}
+	}
+
+	emap, mu := epb.extensionsRead()
+	if emap == nil {
+		return defaultExtensionValue(extension)
+	}
+	mu.Lock()
+	defer mu.Unlock()
+	e, ok := emap[extension.Field]
+	if !ok {
+		// defaultExtensionValue returns the default value or
+		// ErrMissingExtension if there is no default.
+		return defaultExtensionValue(extension)
+	}
+
+	if e.value != nil {
+		// Already decoded. Check the descriptor, though.
+		if e.desc != extension {
+			// This shouldn't happen. If it does, it means that
+			// GetExtension was called twice with two different
+			// descriptors with the same field number.
+			return nil, errors.New("proto: descriptor conflict")
+		}
+		return e.value, nil
+	}
+
+	if extension.ExtensionType == nil {
+		// incomplete descriptor
+		return e.enc, nil
+	}
+
+	v, err := decodeExtension(e.enc, extension)
+	if err != nil {
+		return nil, err
+	}
+
+	// Remember the decoded version and drop the encoded version.
+	// That way it is safe to mutate what we return.
+	e.value = v
+	e.desc = extension
+	e.enc = nil
+	emap[extension.Field] = e
+	return e.value, nil
+}
+
+// defaultExtensionValue returns the default value for extension.
+// If no default for an extension is defined ErrMissingExtension is returned.
+func defaultExtensionValue(extension *ExtensionDesc) (interface{}, error) {
+	if extension.ExtensionType == nil {
+		// incomplete descriptor, so no default
+		return nil, ErrMissingExtension
+	}
+
+	t := reflect.TypeOf(extension.ExtensionType)
+	props := extensionProperties(extension)
+
+	sf, _, err := fieldDefault(t, props)
+	if err != nil {
+		return nil, err
+	}
+
+	if sf == nil || sf.value == nil {
+		// There is no default value.
+		return nil, ErrMissingExtension
+	}
+
+	if t.Kind() != reflect.Ptr {
+		// We do not need to return a Ptr, we can directly return sf.value.
+		return sf.value, nil
+	}
+
+	// We need to return an interface{} that is a pointer to sf.value.
+	value := reflect.New(t).Elem()
+	value.Set(reflect.New(value.Type().Elem()))
+	if sf.kind == reflect.Int32 {
+		// We may have an int32 or an enum, but the underlying data is int32.
+		// Since we can't set an int32 into a non int32 reflect.value directly
+		// set it as a int32.
+		value.Elem().SetInt(int64(sf.value.(int32)))
+	} else {
+		value.Elem().Set(reflect.ValueOf(sf.value))
+	}
+	return value.Interface(), nil
+}
+
+// decodeExtension decodes an extension encoded in b.
+func decodeExtension(b []byte, extension *ExtensionDesc) (interface{}, error) {
+	t := reflect.TypeOf(extension.ExtensionType)
+	unmarshal := typeUnmarshaler(t, extension.Tag)
+
+	// t is a pointer to a struct, pointer to basic type or a slice.
+	// Allocate space to store the pointer/slice.
+	value := reflect.New(t).Elem()
+
+	var err error
+	for {
+		x, n := decodeVarint(b)
+		if n == 0 {
+			return nil, io.ErrUnexpectedEOF
+		}
+		b = b[n:]
+		wire := int(x) & 7
+
+		b, err = unmarshal(b, valToPointer(value.Addr()), wire)
+		if err != nil {
+			return nil, err
+		}
+
+		if len(b) == 0 {
+			break
+		}
+	}
+	return value.Interface(), nil
+}
+
+// GetExtensions returns a slice of the extensions present in pb that are also listed in es.
+// The returned slice has the same length as es; missing extensions will appear as nil elements.
+func GetExtensions(pb Message, es []*ExtensionDesc) (extensions []interface{}, err error) {
+	epb, err := extendable(pb)
+	if err != nil {
+		return nil, err
+	}
+	extensions = make([]interface{}, len(es))
+	for i, e := range es {
+		extensions[i], err = GetExtension(epb, e)
+		if err == ErrMissingExtension {
+			err = nil
+		}
+		if err != nil {
+			return
+		}
+	}
+	return
+}
+
+// ExtensionDescs returns a new slice containing pb's extension descriptors, in undefined order.
+// For non-registered extensions, ExtensionDescs returns an incomplete descriptor containing
+// just the Field field, which defines the extension's field number.
+func ExtensionDescs(pb Message) ([]*ExtensionDesc, error) {
+	epb, err := extendable(pb)
+	if err != nil {
+		return nil, err
+	}
+	registeredExtensions := RegisteredExtensions(pb)
+
+	emap, mu := epb.extensionsRead()
+	if emap == nil {
+		return nil, nil
+	}
+	mu.Lock()
+	defer mu.Unlock()
+	extensions := make([]*ExtensionDesc, 0, len(emap))
+	for extid, e := range emap {
+		desc := e.desc
+		if desc == nil {
+			desc = registeredExtensions[extid]
+			if desc == nil {
+				desc = &ExtensionDesc{Field: extid}
+			}
+		}
+
+		extensions = append(extensions, desc)
+	}
+	return extensions, nil
+}
+
+// SetExtension sets the specified extension of pb to the specified value.
+func SetExtension(pb Message, extension *ExtensionDesc, value interface{}) error {
+	epb, err := extendable(pb)
+	if err != nil {
+		return err
+	}
+	if err := checkExtensionTypes(epb, extension); err != nil {
+		return err
+	}
+	typ := reflect.TypeOf(extension.ExtensionType)
+	if typ != reflect.TypeOf(value) {
+		return errors.New("proto: bad extension value type")
+	}
+	// nil extension values need to be caught early, because the
+	// encoder can't distinguish an ErrNil due to a nil extension
+	// from an ErrNil due to a missing field. Extensions are
+	// always optional, so the encoder would just swallow the error
+	// and drop all the extensions from the encoded message.
+	if reflect.ValueOf(value).IsNil() {
+		return fmt.Errorf("proto: SetExtension called with nil value of type %T", value)
+	}
+
+	extmap := epb.extensionsWrite()
+	extmap[extension.Field] = Extension{desc: extension, value: value}
+	return nil
+}
+
+// ClearAllExtensions clears all extensions from pb.
+func ClearAllExtensions(pb Message) {
+	epb, err := extendable(pb)
+	if err != nil {
+		return
+	}
+	m := epb.extensionsWrite()
+	for k := range m {
+		delete(m, k)
+	}
+}
+
+// A global registry of extensions.
+// The generated code will register the generated descriptors by calling RegisterExtension.
+
+var extensionMaps = make(map[reflect.Type]map[int32]*ExtensionDesc)
+
+// RegisterExtension is called from the generated code.
+func RegisterExtension(desc *ExtensionDesc) {
+	st := reflect.TypeOf(desc.ExtendedType).Elem()
+	m := extensionMaps[st]
+	if m == nil {
+		m = make(map[int32]*ExtensionDesc)
+		extensionMaps[st] = m
+	}
+	if _, ok := m[desc.Field]; ok {
+		panic("proto: duplicate extension registered: " + st.String() + " " + strconv.Itoa(int(desc.Field)))
+	}
+	m[desc.Field] = desc
+}
+
+// RegisteredExtensions returns a map of the registered extensions of a
+// protocol buffer struct, indexed by the extension number.
+// The argument pb should be a nil pointer to the struct type.
+func RegisteredExtensions(pb Message) map[int32]*ExtensionDesc {
+	return extensionMaps[reflect.TypeOf(pb).Elem()]
+}
diff --git a/vendor/github.com/golang/protobuf/proto/lib.go b/vendor/github.com/golang/protobuf/proto/lib.go
new file mode 100644
index 0000000..75565cc
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/lib.go
@@ -0,0 +1,979 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2010 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+/*
+Package proto converts data structures to and from the wire format of
+protocol buffers.  It works in concert with the Go source code generated
+for .proto files by the protocol compiler.
+
+A summary of the properties of the protocol buffer interface
+for a protocol buffer variable v:
+
+  - Names are turned from camel_case to CamelCase for export.
+  - There are no methods on v to set fields; just treat
+	them as structure fields.
+  - There are getters that return a field's value if set,
+	and return the field's default value if unset.
+	The getters work even if the receiver is a nil message.
+  - The zero value for a struct is its correct initialization state.
+	All desired fields must be set before marshaling.
+  - A Reset() method will restore a protobuf struct to its zero state.
+  - Non-repeated fields are pointers to the values; nil means unset.
+	That is, optional or required field int32 f becomes F *int32.
+  - Repeated fields are slices.
+  - Helper functions are available to aid the setting of fields.
+	msg.Foo = proto.String("hello") // set field
+  - Constants are defined to hold the default values of all fields that
+	have them.  They have the form Default_StructName_FieldName.
+	Because the getter methods handle defaulted values,
+	direct use of these constants should be rare.
+  - Enums are given type names and maps from names to values.
+	Enum values are prefixed by the enclosing message's name, or by the
+	enum's type name if it is a top-level enum. Enum types have a String
+	method, and a Enum method to assist in message construction.
+  - Nested messages, groups and enums have type names prefixed with the name of
+	the surrounding message type.
+  - Extensions are given descriptor names that start with E_,
+	followed by an underscore-delimited list of the nested messages
+	that contain it (if any) followed by the CamelCased name of the
+	extension field itself.  HasExtension, ClearExtension, GetExtension
+	and SetExtension are functions for manipulating extensions.
+  - Oneof field sets are given a single field in their message,
+	with distinguished wrapper types for each possible field value.
+  - Marshal and Unmarshal are functions to encode and decode the wire format.
+
+When the .proto file specifies `syntax="proto3"`, there are some differences:
+
+  - Non-repeated fields of non-message type are values instead of pointers.
+  - Enum types do not get an Enum method.
+
+The simplest way to describe this is to see an example.
+Given file test.proto, containing
+
+	package example;
+
+	enum FOO { X = 17; }
+
+	message Test {
+	  required string label = 1;
+	  optional int32 type = 2 [default=77];
+	  repeated int64 reps = 3;
+	  optional group OptionalGroup = 4 {
+	    required string RequiredField = 5;
+	  }
+	  oneof union {
+	    int32 number = 6;
+	    string name = 7;
+	  }
+	}
+
+The resulting file, test.pb.go, is:
+
+	package example
+
+	import proto "github.com/golang/protobuf/proto"
+	import math "math"
+
+	type FOO int32
+	const (
+		FOO_X FOO = 17
+	)
+	var FOO_name = map[int32]string{
+		17: "X",
+	}
+	var FOO_value = map[string]int32{
+		"X": 17,
+	}
+
+	func (x FOO) Enum() *FOO {
+		p := new(FOO)
+		*p = x
+		return p
+	}
+	func (x FOO) String() string {
+		return proto.EnumName(FOO_name, int32(x))
+	}
+	func (x *FOO) UnmarshalJSON(data []byte) error {
+		value, err := proto.UnmarshalJSONEnum(FOO_value, data)
+		if err != nil {
+			return err
+		}
+		*x = FOO(value)
+		return nil
+	}
+
+	type Test struct {
+		Label         *string             `protobuf:"bytes,1,req,name=label" json:"label,omitempty"`
+		Type          *int32              `protobuf:"varint,2,opt,name=type,def=77" json:"type,omitempty"`
+		Reps          []int64             `protobuf:"varint,3,rep,name=reps" json:"reps,omitempty"`
+		Optionalgroup *Test_OptionalGroup `protobuf:"group,4,opt,name=OptionalGroup" json:"optionalgroup,omitempty"`
+		// Types that are valid to be assigned to Union:
+		//	*Test_Number
+		//	*Test_Name
+		Union            isTest_Union `protobuf_oneof:"union"`
+		XXX_unrecognized []byte       `json:"-"`
+	}
+	func (m *Test) Reset()         { *m = Test{} }
+	func (m *Test) String() string { return proto.CompactTextString(m) }
+	func (*Test) ProtoMessage() {}
+
+	type isTest_Union interface {
+		isTest_Union()
+	}
+
+	type Test_Number struct {
+		Number int32 `protobuf:"varint,6,opt,name=number"`
+	}
+	type Test_Name struct {
+		Name string `protobuf:"bytes,7,opt,name=name"`
+	}
+
+	func (*Test_Number) isTest_Union() {}
+	func (*Test_Name) isTest_Union()   {}
+
+	func (m *Test) GetUnion() isTest_Union {
+		if m != nil {
+			return m.Union
+		}
+		return nil
+	}
+	const Default_Test_Type int32 = 77
+
+	func (m *Test) GetLabel() string {
+		if m != nil && m.Label != nil {
+			return *m.Label
+		}
+		return ""
+	}
+
+	func (m *Test) GetType() int32 {
+		if m != nil && m.Type != nil {
+			return *m.Type
+		}
+		return Default_Test_Type
+	}
+
+	func (m *Test) GetOptionalgroup() *Test_OptionalGroup {
+		if m != nil {
+			return m.Optionalgroup
+		}
+		return nil
+	}
+
+	type Test_OptionalGroup struct {
+		RequiredField *string `protobuf:"bytes,5,req" json:"RequiredField,omitempty"`
+	}
+	func (m *Test_OptionalGroup) Reset()         { *m = Test_OptionalGroup{} }
+	func (m *Test_OptionalGroup) String() string { return proto.CompactTextString(m) }
+
+	func (m *Test_OptionalGroup) GetRequiredField() string {
+		if m != nil && m.RequiredField != nil {
+			return *m.RequiredField
+		}
+		return ""
+	}
+
+	func (m *Test) GetNumber() int32 {
+		if x, ok := m.GetUnion().(*Test_Number); ok {
+			return x.Number
+		}
+		return 0
+	}
+
+	func (m *Test) GetName() string {
+		if x, ok := m.GetUnion().(*Test_Name); ok {
+			return x.Name
+		}
+		return ""
+	}
+
+	func init() {
+		proto.RegisterEnum("example.FOO", FOO_name, FOO_value)
+	}
+
+To create and play with a Test object:
+
+	package main
+
+	import (
+		"log"
+
+		"github.com/golang/protobuf/proto"
+		pb "./example.pb"
+	)
+
+	func main() {
+		test := &pb.Test{
+			Label: proto.String("hello"),
+			Type:  proto.Int32(17),
+			Reps:  []int64{1, 2, 3},
+			Optionalgroup: &pb.Test_OptionalGroup{
+				RequiredField: proto.String("good bye"),
+			},
+			Union: &pb.Test_Name{"fred"},
+		}
+		data, err := proto.Marshal(test)
+		if err != nil {
+			log.Fatal("marshaling error: ", err)
+		}
+		newTest := &pb.Test{}
+		err = proto.Unmarshal(data, newTest)
+		if err != nil {
+			log.Fatal("unmarshaling error: ", err)
+		}
+		// Now test and newTest contain the same data.
+		if test.GetLabel() != newTest.GetLabel() {
+			log.Fatalf("data mismatch %q != %q", test.GetLabel(), newTest.GetLabel())
+		}
+		// Use a type switch to determine which oneof was set.
+		switch u := test.Union.(type) {
+		case *pb.Test_Number: // u.Number contains the number.
+		case *pb.Test_Name: // u.Name contains the string.
+		}
+		// etc.
+	}
+*/
+package proto
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"reflect"
+	"sort"
+	"strconv"
+	"sync"
+)
+
+// RequiredNotSetError is an error type returned by either Marshal or Unmarshal.
+// Marshal reports this when a required field is not initialized.
+// Unmarshal reports this when a required field is missing from the wire data.
+type RequiredNotSetError struct{ field string }
+
+func (e *RequiredNotSetError) Error() string {
+	if e.field == "" {
+		return fmt.Sprintf("proto: required field not set")
+	}
+	return fmt.Sprintf("proto: required field %q not set", e.field)
+}
+func (e *RequiredNotSetError) RequiredNotSet() bool {
+	return true
+}
+
+type invalidUTF8Error struct{ field string }
+
+func (e *invalidUTF8Error) Error() string {
+	if e.field == "" {
+		return "proto: invalid UTF-8 detected"
+	}
+	return fmt.Sprintf("proto: field %q contains invalid UTF-8", e.field)
+}
+func (e *invalidUTF8Error) InvalidUTF8() bool {
+	return true
+}
+
+// errInvalidUTF8 is a sentinel error to identify fields with invalid UTF-8.
+// This error should not be exposed to the external API as such errors should
+// be recreated with the field information.
+var errInvalidUTF8 = &invalidUTF8Error{}
+
+// isNonFatal reports whether the error is either a RequiredNotSet error
+// or a InvalidUTF8 error.
+func isNonFatal(err error) bool {
+	if re, ok := err.(interface{ RequiredNotSet() bool }); ok && re.RequiredNotSet() {
+		return true
+	}
+	if re, ok := err.(interface{ InvalidUTF8() bool }); ok && re.InvalidUTF8() {
+		return true
+	}
+	return false
+}
+
+type nonFatal struct{ E error }
+
+// Merge merges err into nf and reports whether it was successful.
+// Otherwise it returns false for any fatal non-nil errors.
+func (nf *nonFatal) Merge(err error) (ok bool) {
+	if err == nil {
+		return true // not an error
+	}
+	if !isNonFatal(err) {
+		return false // fatal error
+	}
+	if nf.E == nil {
+		nf.E = err // store first instance of non-fatal error
+	}
+	return true
+}
+
+// Message is implemented by generated protocol buffer messages.
+type Message interface {
+	Reset()
+	String() string
+	ProtoMessage()
+}
+
+// Stats records allocation details about the protocol buffer encoders
+// and decoders.  Useful for tuning the library itself.
+type Stats struct {
+	Emalloc uint64 // mallocs in encode
+	Dmalloc uint64 // mallocs in decode
+	Encode  uint64 // number of encodes
+	Decode  uint64 // number of decodes
+	Chit    uint64 // number of cache hits
+	Cmiss   uint64 // number of cache misses
+	Size    uint64 // number of sizes
+}
+
+// Set to true to enable stats collection.
+const collectStats = false
+
+var stats Stats
+
+// GetStats returns a copy of the global Stats structure.
+func GetStats() Stats { return stats }
+
+// A Buffer is a buffer manager for marshaling and unmarshaling
+// protocol buffers.  It may be reused between invocations to
+// reduce memory usage.  It is not necessary to use a Buffer;
+// the global functions Marshal and Unmarshal create a
+// temporary Buffer and are fine for most applications.
+type Buffer struct {
+	buf   []byte // encode/decode byte stream
+	index int    // read point
+
+	deterministic bool
+}
+
+// NewBuffer allocates a new Buffer and initializes its internal data to
+// the contents of the argument slice.
+func NewBuffer(e []byte) *Buffer {
+	return &Buffer{buf: e}
+}
+
+// Reset resets the Buffer, ready for marshaling a new protocol buffer.
+func (p *Buffer) Reset() {
+	p.buf = p.buf[0:0] // for reading/writing
+	p.index = 0        // for reading
+}
+
+// SetBuf replaces the internal buffer with the slice,
+// ready for unmarshaling the contents of the slice.
+func (p *Buffer) SetBuf(s []byte) {
+	p.buf = s
+	p.index = 0
+}
+
+// Bytes returns the contents of the Buffer.
+func (p *Buffer) Bytes() []byte { return p.buf }
+
+// SetDeterministic sets whether to use deterministic serialization.
+//
+// Deterministic serialization guarantees that for a given binary, equal
+// messages will always be serialized to the same bytes. This implies:
+//
+//   - Repeated serialization of a message will return the same bytes.
+//   - Different processes of the same binary (which may be executing on
+//     different machines) will serialize equal messages to the same bytes.
+//
+// Note that the deterministic serialization is NOT canonical across
+// languages. It is not guaranteed to remain stable over time. It is unstable
+// across different builds with schema changes due to unknown fields.
+// Users who need canonical serialization (e.g., persistent storage in a
+// canonical form, fingerprinting, etc.) should define their own
+// canonicalization specification and implement their own serializer rather
+// than relying on this API.
+//
+// If deterministic serialization is requested, map entries will be sorted
+// by keys in lexographical order. This is an implementation detail and
+// subject to change.
+func (p *Buffer) SetDeterministic(deterministic bool) {
+	p.deterministic = deterministic
+}
+
+/*
+ * Helper routines for simplifying the creation of optional fields of basic type.
+ */
+
+// Bool is a helper routine that allocates a new bool value
+// to store v and returns a pointer to it.
+func Bool(v bool) *bool {
+	return &v
+}
+
+// Int32 is a helper routine that allocates a new int32 value
+// to store v and returns a pointer to it.
+func Int32(v int32) *int32 {
+	return &v
+}
+
+// Int is a helper routine that allocates a new int32 value
+// to store v and returns a pointer to it, but unlike Int32
+// its argument value is an int.
+func Int(v int) *int32 {
+	p := new(int32)
+	*p = int32(v)
+	return p
+}
+
+// Int64 is a helper routine that allocates a new int64 value
+// to store v and returns a pointer to it.
+func Int64(v int64) *int64 {
+	return &v
+}
+
+// Float32 is a helper routine that allocates a new float32 value
+// to store v and returns a pointer to it.
+func Float32(v float32) *float32 {
+	return &v
+}
+
+// Float64 is a helper routine that allocates a new float64 value
+// to store v and returns a pointer to it.
+func Float64(v float64) *float64 {
+	return &v
+}
+
+// Uint32 is a helper routine that allocates a new uint32 value
+// to store v and returns a pointer to it.
+func Uint32(v uint32) *uint32 {
+	return &v
+}
+
+// Uint64 is a helper routine that allocates a new uint64 value
+// to store v and returns a pointer to it.
+func Uint64(v uint64) *uint64 {
+	return &v
+}
+
+// String is a helper routine that allocates a new string value
+// to store v and returns a pointer to it.
+func String(v string) *string {
+	return &v
+}
+
+// EnumName is a helper function to simplify printing protocol buffer enums
+// by name.  Given an enum map and a value, it returns a useful string.
+func EnumName(m map[int32]string, v int32) string {
+	s, ok := m[v]
+	if ok {
+		return s
+	}
+	return strconv.Itoa(int(v))
+}
+
+// UnmarshalJSONEnum is a helper function to simplify recovering enum int values
+// from their JSON-encoded representation. Given a map from the enum's symbolic
+// names to its int values, and a byte buffer containing the JSON-encoded
+// value, it returns an int32 that can be cast to the enum type by the caller.
+//
+// The function can deal with both JSON representations, numeric and symbolic.
+func UnmarshalJSONEnum(m map[string]int32, data []byte, enumName string) (int32, error) {
+	if data[0] == '"' {
+		// New style: enums are strings.
+		var repr string
+		if err := json.Unmarshal(data, &repr); err != nil {
+			return -1, err
+		}
+		val, ok := m[repr]
+		if !ok {
+			return 0, fmt.Errorf("unrecognized enum %s value %q", enumName, repr)
+		}
+		return val, nil
+	}
+	// Old style: enums are ints.
+	var val int32
+	if err := json.Unmarshal(data, &val); err != nil {
+		return 0, fmt.Errorf("cannot unmarshal %#q into enum %s", data, enumName)
+	}
+	return val, nil
+}
+
+// DebugPrint dumps the encoded data in b in a debugging format with a header
+// including the string s. Used in testing but made available for general debugging.
+func (p *Buffer) DebugPrint(s string, b []byte) {
+	var u uint64
+
+	obuf := p.buf
+	index := p.index
+	p.buf = b
+	p.index = 0
+	depth := 0
+
+	fmt.Printf("\n--- %s ---\n", s)
+
+out:
+	for {
+		for i := 0; i < depth; i++ {
+			fmt.Print("  ")
+		}
+
+		index := p.index
+		if index == len(p.buf) {
+			break
+		}
+
+		op, err := p.DecodeVarint()
+		if err != nil {
+			fmt.Printf("%3d: fetching op err %v\n", index, err)
+			break out
+		}
+		tag := op >> 3
+		wire := op & 7
+
+		switch wire {
+		default:
+			fmt.Printf("%3d: t=%3d unknown wire=%d\n",
+				index, tag, wire)
+			break out
+
+		case WireBytes:
+			var r []byte
+
+			r, err = p.DecodeRawBytes(false)
+			if err != nil {
+				break out
+			}
+			fmt.Printf("%3d: t=%3d bytes [%d]", index, tag, len(r))
+			if len(r) <= 6 {
+				for i := 0; i < len(r); i++ {
+					fmt.Printf(" %.2x", r[i])
+				}
+			} else {
+				for i := 0; i < 3; i++ {
+					fmt.Printf(" %.2x", r[i])
+				}
+				fmt.Printf(" ..")
+				for i := len(r) - 3; i < len(r); i++ {
+					fmt.Printf(" %.2x", r[i])
+				}
+			}
+			fmt.Printf("\n")
+
+		case WireFixed32:
+			u, err = p.DecodeFixed32()
+			if err != nil {
+				fmt.Printf("%3d: t=%3d fix32 err %v\n", index, tag, err)
+				break out
+			}
+			fmt.Printf("%3d: t=%3d fix32 %d\n", index, tag, u)
+
+		case WireFixed64:
+			u, err = p.DecodeFixed64()
+			if err != nil {
+				fmt.Printf("%3d: t=%3d fix64 err %v\n", index, tag, err)
+				break out
+			}
+			fmt.Printf("%3d: t=%3d fix64 %d\n", index, tag, u)
+
+		case WireVarint:
+			u, err = p.DecodeVarint()
+			if err != nil {
+				fmt.Printf("%3d: t=%3d varint err %v\n", index, tag, err)
+				break out
+			}
+			fmt.Printf("%3d: t=%3d varint %d\n", index, tag, u)
+
+		case WireStartGroup:
+			fmt.Printf("%3d: t=%3d start\n", index, tag)
+			depth++
+
+		case WireEndGroup:
+			depth--
+			fmt.Printf("%3d: t=%3d end\n", index, tag)
+		}
+	}
+
+	if depth != 0 {
+		fmt.Printf("%3d: start-end not balanced %d\n", p.index, depth)
+	}
+	fmt.Printf("\n")
+
+	p.buf = obuf
+	p.index = index
+}
+
+// SetDefaults sets unset protocol buffer fields to their default values.
+// It only modifies fields that are both unset and have defined defaults.
+// It recursively sets default values in any non-nil sub-messages.
+func SetDefaults(pb Message) {
+	setDefaults(reflect.ValueOf(pb), true, false)
+}
+
+// v is a pointer to a struct.
+func setDefaults(v reflect.Value, recur, zeros bool) {
+	v = v.Elem()
+
+	defaultMu.RLock()
+	dm, ok := defaults[v.Type()]
+	defaultMu.RUnlock()
+	if !ok {
+		dm = buildDefaultMessage(v.Type())
+		defaultMu.Lock()
+		defaults[v.Type()] = dm
+		defaultMu.Unlock()
+	}
+
+	for _, sf := range dm.scalars {
+		f := v.Field(sf.index)
+		if !f.IsNil() {
+			// field already set
+			continue
+		}
+		dv := sf.value
+		if dv == nil && !zeros {
+			// no explicit default, and don't want to set zeros
+			continue
+		}
+		fptr := f.Addr().Interface() // **T
+		// TODO: Consider batching the allocations we do here.
+		switch sf.kind {
+		case reflect.Bool:
+			b := new(bool)
+			if dv != nil {
+				*b = dv.(bool)
+			}
+			*(fptr.(**bool)) = b
+		case reflect.Float32:
+			f := new(float32)
+			if dv != nil {
+				*f = dv.(float32)
+			}
+			*(fptr.(**float32)) = f
+		case reflect.Float64:
+			f := new(float64)
+			if dv != nil {
+				*f = dv.(float64)
+			}
+			*(fptr.(**float64)) = f
+		case reflect.Int32:
+			// might be an enum
+			if ft := f.Type(); ft != int32PtrType {
+				// enum
+				f.Set(reflect.New(ft.Elem()))
+				if dv != nil {
+					f.Elem().SetInt(int64(dv.(int32)))
+				}
+			} else {
+				// int32 field
+				i := new(int32)
+				if dv != nil {
+					*i = dv.(int32)
+				}
+				*(fptr.(**int32)) = i
+			}
+		case reflect.Int64:
+			i := new(int64)
+			if dv != nil {
+				*i = dv.(int64)
+			}
+			*(fptr.(**int64)) = i
+		case reflect.String:
+			s := new(string)
+			if dv != nil {
+				*s = dv.(string)
+			}
+			*(fptr.(**string)) = s
+		case reflect.Uint8:
+			// exceptional case: []byte
+			var b []byte
+			if dv != nil {
+				db := dv.([]byte)
+				b = make([]byte, len(db))
+				copy(b, db)
+			} else {
+				b = []byte{}
+			}
+			*(fptr.(*[]byte)) = b
+		case reflect.Uint32:
+			u := new(uint32)
+			if dv != nil {
+				*u = dv.(uint32)
+			}
+			*(fptr.(**uint32)) = u
+		case reflect.Uint64:
+			u := new(uint64)
+			if dv != nil {
+				*u = dv.(uint64)
+			}
+			*(fptr.(**uint64)) = u
+		default:
+			log.Printf("proto: can't set default for field %v (sf.kind=%v)", f, sf.kind)
+		}
+	}
+
+	for _, ni := range dm.nested {
+		f := v.Field(ni)
+		// f is *T or []*T or map[T]*T
+		switch f.Kind() {
+		case reflect.Ptr:
+			if f.IsNil() {
+				continue
+			}
+			setDefaults(f, recur, zeros)
+
+		case reflect.Slice:
+			for i := 0; i < f.Len(); i++ {
+				e := f.Index(i)
+				if e.IsNil() {
+					continue
+				}
+				setDefaults(e, recur, zeros)
+			}
+
+		case reflect.Map:
+			for _, k := range f.MapKeys() {
+				e := f.MapIndex(k)
+				if e.IsNil() {
+					continue
+				}
+				setDefaults(e, recur, zeros)
+			}
+		}
+	}
+}
+
+var (
+	// defaults maps a protocol buffer struct type to a slice of the fields,
+	// with its scalar fields set to their proto-declared non-zero default values.
+	defaultMu sync.RWMutex
+	defaults  = make(map[reflect.Type]defaultMessage)
+
+	int32PtrType = reflect.TypeOf((*int32)(nil))
+)
+
+// defaultMessage represents information about the default values of a message.
+type defaultMessage struct {
+	scalars []scalarField
+	nested  []int // struct field index of nested messages
+}
+
+type scalarField struct {
+	index int          // struct field index
+	kind  reflect.Kind // element type (the T in *T or []T)
+	value interface{}  // the proto-declared default value, or nil
+}
+
+// t is a struct type.
+func buildDefaultMessage(t reflect.Type) (dm defaultMessage) {
+	sprop := GetProperties(t)
+	for _, prop := range sprop.Prop {
+		fi, ok := sprop.decoderTags.get(prop.Tag)
+		if !ok {
+			// XXX_unrecognized
+			continue
+		}
+		ft := t.Field(fi).Type
+
+		sf, nested, err := fieldDefault(ft, prop)
+		switch {
+		case err != nil:
+			log.Print(err)
+		case nested:
+			dm.nested = append(dm.nested, fi)
+		case sf != nil:
+			sf.index = fi
+			dm.scalars = append(dm.scalars, *sf)
+		}
+	}
+
+	return dm
+}
+
+// fieldDefault returns the scalarField for field type ft.
+// sf will be nil if the field can not have a default.
+// nestedMessage will be true if this is a nested message.
+// Note that sf.index is not set on return.
+func fieldDefault(ft reflect.Type, prop *Properties) (sf *scalarField, nestedMessage bool, err error) {
+	var canHaveDefault bool
+	switch ft.Kind() {
+	case reflect.Ptr:
+		if ft.Elem().Kind() == reflect.Struct {
+			nestedMessage = true
+		} else {
+			canHaveDefault = true // proto2 scalar field
+		}
+
+	case reflect.Slice:
+		switch ft.Elem().Kind() {
+		case reflect.Ptr:
+			nestedMessage = true // repeated message
+		case reflect.Uint8:
+			canHaveDefault = true // bytes field
+		}
+
+	case reflect.Map:
+		if ft.Elem().Kind() == reflect.Ptr {
+			nestedMessage = true // map with message values
+		}
+	}
+
+	if !canHaveDefault {
+		if nestedMessage {
+			return nil, true, nil
+		}
+		return nil, false, nil
+	}
+
+	// We now know that ft is a pointer or slice.
+	sf = &scalarField{kind: ft.Elem().Kind()}
+
+	// scalar fields without defaults
+	if !prop.HasDefault {
+		return sf, false, nil
+	}
+
+	// a scalar field: either *T or []byte
+	switch ft.Elem().Kind() {
+	case reflect.Bool:
+		x, err := strconv.ParseBool(prop.Default)
+		if err != nil {
+			return nil, false, fmt.Errorf("proto: bad default bool %q: %v", prop.Default, err)
+		}
+		sf.value = x
+	case reflect.Float32:
+		x, err := strconv.ParseFloat(prop.Default, 32)
+		if err != nil {
+			return nil, false, fmt.Errorf("proto: bad default float32 %q: %v", prop.Default, err)
+		}
+		sf.value = float32(x)
+	case reflect.Float64:
+		x, err := strconv.ParseFloat(prop.Default, 64)
+		if err != nil {
+			return nil, false, fmt.Errorf("proto: bad default float64 %q: %v", prop.Default, err)
+		}
+		sf.value = x
+	case reflect.Int32:
+		x, err := strconv.ParseInt(prop.Default, 10, 32)
+		if err != nil {
+			return nil, false, fmt.Errorf("proto: bad default int32 %q: %v", prop.Default, err)
+		}
+		sf.value = int32(x)
+	case reflect.Int64:
+		x, err := strconv.ParseInt(prop.Default, 10, 64)
+		if err != nil {
+			return nil, false, fmt.Errorf("proto: bad default int64 %q: %v", prop.Default, err)
+		}
+		sf.value = x
+	case reflect.String:
+		sf.value = prop.Default
+	case reflect.Uint8:
+		// []byte (not *uint8)
+		sf.value = []byte(prop.Default)
+	case reflect.Uint32:
+		x, err := strconv.ParseUint(prop.Default, 10, 32)
+		if err != nil {
+			return nil, false, fmt.Errorf("proto: bad default uint32 %q: %v", prop.Default, err)
+		}
+		sf.value = uint32(x)
+	case reflect.Uint64:
+		x, err := strconv.ParseUint(prop.Default, 10, 64)
+		if err != nil {
+			return nil, false, fmt.Errorf("proto: bad default uint64 %q: %v", prop.Default, err)
+		}
+		sf.value = x
+	default:
+		return nil, false, fmt.Errorf("proto: unhandled def kind %v", ft.Elem().Kind())
+	}
+
+	return sf, false, nil
+}
+
+// mapKeys returns a sort.Interface to be used for sorting the map keys.
+// Map fields may have key types of non-float scalars, strings and enums.
+func mapKeys(vs []reflect.Value) sort.Interface {
+	s := mapKeySorter{vs: vs}
+
+	// Type specialization per https://developers.google.com/protocol-buffers/docs/proto#maps.
+	if len(vs) == 0 {
+		return s
+	}
+	switch vs[0].Kind() {
+	case reflect.Int32, reflect.Int64:
+		s.less = func(a, b reflect.Value) bool { return a.Int() < b.Int() }
+	case reflect.Uint32, reflect.Uint64:
+		s.less = func(a, b reflect.Value) bool { return a.Uint() < b.Uint() }
+	case reflect.Bool:
+		s.less = func(a, b reflect.Value) bool { return !a.Bool() && b.Bool() } // false < true
+	case reflect.String:
+		s.less = func(a, b reflect.Value) bool { return a.String() < b.String() }
+	default:
+		panic(fmt.Sprintf("unsupported map key type: %v", vs[0].Kind()))
+	}
+
+	return s
+}
+
+type mapKeySorter struct {
+	vs   []reflect.Value
+	less func(a, b reflect.Value) bool
+}
+
+func (s mapKeySorter) Len() int      { return len(s.vs) }
+func (s mapKeySorter) Swap(i, j int) { s.vs[i], s.vs[j] = s.vs[j], s.vs[i] }
+func (s mapKeySorter) Less(i, j int) bool {
+	return s.less(s.vs[i], s.vs[j])
+}
+
+// isProto3Zero reports whether v is a zero proto3 value.
+func isProto3Zero(v reflect.Value) bool {
+	switch v.Kind() {
+	case reflect.Bool:
+		return !v.Bool()
+	case reflect.Int32, reflect.Int64:
+		return v.Int() == 0
+	case reflect.Uint32, reflect.Uint64:
+		return v.Uint() == 0
+	case reflect.Float32, reflect.Float64:
+		return v.Float() == 0
+	case reflect.String:
+		return v.String() == ""
+	}
+	return false
+}
+
+// ProtoPackageIsVersion2 is referenced from generated protocol buffer files
+// to assert that that code is compatible with this version of the proto package.
+const ProtoPackageIsVersion2 = true
+
+// ProtoPackageIsVersion1 is referenced from generated protocol buffer files
+// to assert that that code is compatible with this version of the proto package.
+const ProtoPackageIsVersion1 = true
+
+// InternalMessageInfo is a type used internally by generated .pb.go files.
+// This type is not intended to be used by non-generated code.
+// This type is not subject to any compatibility guarantee.
+type InternalMessageInfo struct {
+	marshal   *marshalInfo
+	unmarshal *unmarshalInfo
+	merge     *mergeInfo
+	discard   *discardInfo
+}
diff --git a/vendor/github.com/golang/protobuf/proto/message_set.go b/vendor/github.com/golang/protobuf/proto/message_set.go
new file mode 100644
index 0000000..3b6ca41
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/message_set.go
@@ -0,0 +1,314 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2010 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package proto
+
+/*
+ * Support for message sets.
+ */
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"reflect"
+	"sort"
+	"sync"
+)
+
+// errNoMessageTypeID occurs when a protocol buffer does not have a message type ID.
+// A message type ID is required for storing a protocol buffer in a message set.
+var errNoMessageTypeID = errors.New("proto does not have a message type ID")
+
+// The first two types (_MessageSet_Item and messageSet)
+// model what the protocol compiler produces for the following protocol message:
+//   message MessageSet {
+//     repeated group Item = 1 {
+//       required int32 type_id = 2;
+//       required string message = 3;
+//     };
+//   }
+// That is the MessageSet wire format. We can't use a proto to generate these
+// because that would introduce a circular dependency between it and this package.
+
+type _MessageSet_Item struct {
+	TypeId  *int32 `protobuf:"varint,2,req,name=type_id"`
+	Message []byte `protobuf:"bytes,3,req,name=message"`
+}
+
+type messageSet struct {
+	Item             []*_MessageSet_Item `protobuf:"group,1,rep"`
+	XXX_unrecognized []byte
+	// TODO: caching?
+}
+
+// Make sure messageSet is a Message.
+var _ Message = (*messageSet)(nil)
+
+// messageTypeIder is an interface satisfied by a protocol buffer type
+// that may be stored in a MessageSet.
+type messageTypeIder interface {
+	MessageTypeId() int32
+}
+
+func (ms *messageSet) find(pb Message) *_MessageSet_Item {
+	mti, ok := pb.(messageTypeIder)
+	if !ok {
+		return nil
+	}
+	id := mti.MessageTypeId()
+	for _, item := range ms.Item {
+		if *item.TypeId == id {
+			return item
+		}
+	}
+	return nil
+}
+
+func (ms *messageSet) Has(pb Message) bool {
+	return ms.find(pb) != nil
+}
+
+func (ms *messageSet) Unmarshal(pb Message) error {
+	if item := ms.find(pb); item != nil {
+		return Unmarshal(item.Message, pb)
+	}
+	if _, ok := pb.(messageTypeIder); !ok {
+		return errNoMessageTypeID
+	}
+	return nil // TODO: return error instead?
+}
+
+func (ms *messageSet) Marshal(pb Message) error {
+	msg, err := Marshal(pb)
+	if err != nil {
+		return err
+	}
+	if item := ms.find(pb); item != nil {
+		// reuse existing item
+		item.Message = msg
+		return nil
+	}
+
+	mti, ok := pb.(messageTypeIder)
+	if !ok {
+		return errNoMessageTypeID
+	}
+
+	mtid := mti.MessageTypeId()
+	ms.Item = append(ms.Item, &_MessageSet_Item{
+		TypeId:  &mtid,
+		Message: msg,
+	})
+	return nil
+}
+
+func (ms *messageSet) Reset()         { *ms = messageSet{} }
+func (ms *messageSet) String() string { return CompactTextString(ms) }
+func (*messageSet) ProtoMessage()     {}
+
+// Support for the message_set_wire_format message option.
+
+func skipVarint(buf []byte) []byte {
+	i := 0
+	for ; buf[i]&0x80 != 0; i++ {
+	}
+	return buf[i+1:]
+}
+
+// MarshalMessageSet encodes the extension map represented by m in the message set wire format.
+// It is called by generated Marshal methods on protocol buffer messages with the message_set_wire_format option.
+func MarshalMessageSet(exts interface{}) ([]byte, error) {
+	return marshalMessageSet(exts, false)
+}
+
+// marshaMessageSet implements above function, with the opt to turn on / off deterministic during Marshal.
+func marshalMessageSet(exts interface{}, deterministic bool) ([]byte, error) {
+	switch exts := exts.(type) {
+	case *XXX_InternalExtensions:
+		var u marshalInfo
+		siz := u.sizeMessageSet(exts)
+		b := make([]byte, 0, siz)
+		return u.appendMessageSet(b, exts, deterministic)
+
+	case map[int32]Extension:
+		// This is an old-style extension map.
+		// Wrap it in a new-style XXX_InternalExtensions.
+		ie := XXX_InternalExtensions{
+			p: &struct {
+				mu           sync.Mutex
+				extensionMap map[int32]Extension
+			}{
+				extensionMap: exts,
+			},
+		}
+
+		var u marshalInfo
+		siz := u.sizeMessageSet(&ie)
+		b := make([]byte, 0, siz)
+		return u.appendMessageSet(b, &ie, deterministic)
+
+	default:
+		return nil, errors.New("proto: not an extension map")
+	}
+}
+
+// UnmarshalMessageSet decodes the extension map encoded in buf in the message set wire format.
+// It is called by Unmarshal methods on protocol buffer messages with the message_set_wire_format option.
+func UnmarshalMessageSet(buf []byte, exts interface{}) error {
+	var m map[int32]Extension
+	switch exts := exts.(type) {
+	case *XXX_InternalExtensions:
+		m = exts.extensionsWrite()
+	case map[int32]Extension:
+		m = exts
+	default:
+		return errors.New("proto: not an extension map")
+	}
+
+	ms := new(messageSet)
+	if err := Unmarshal(buf, ms); err != nil {
+		return err
+	}
+	for _, item := range ms.Item {
+		id := *item.TypeId
+		msg := item.Message
+
+		// Restore wire type and field number varint, plus length varint.
+		// Be careful to preserve duplicate items.
+		b := EncodeVarint(uint64(id)<<3 | WireBytes)
+		if ext, ok := m[id]; ok {
+			// Existing data; rip off the tag and length varint
+			// so we join the new data correctly.
+			// We can assume that ext.enc is set because we are unmarshaling.
+			o := ext.enc[len(b):]   // skip wire type and field number
+			_, n := DecodeVarint(o) // calculate length of length varint
+			o = o[n:]               // skip length varint
+			msg = append(o, msg...) // join old data and new data
+		}
+		b = append(b, EncodeVarint(uint64(len(msg)))...)
+		b = append(b, msg...)
+
+		m[id] = Extension{enc: b}
+	}
+	return nil
+}
+
+// MarshalMessageSetJSON encodes the extension map represented by m in JSON format.
+// It is called by generated MarshalJSON methods on protocol buffer messages with the message_set_wire_format option.
+func MarshalMessageSetJSON(exts interface{}) ([]byte, error) {
+	var m map[int32]Extension
+	switch exts := exts.(type) {
+	case *XXX_InternalExtensions:
+		var mu sync.Locker
+		m, mu = exts.extensionsRead()
+		if m != nil {
+			// Keep the extensions map locked until we're done marshaling to prevent
+			// races between marshaling and unmarshaling the lazily-{en,de}coded
+			// values.
+			mu.Lock()
+			defer mu.Unlock()
+		}
+	case map[int32]Extension:
+		m = exts
+	default:
+		return nil, errors.New("proto: not an extension map")
+	}
+	var b bytes.Buffer
+	b.WriteByte('{')
+
+	// Process the map in key order for deterministic output.
+	ids := make([]int32, 0, len(m))
+	for id := range m {
+		ids = append(ids, id)
+	}
+	sort.Sort(int32Slice(ids)) // int32Slice defined in text.go
+
+	for i, id := range ids {
+		ext := m[id]
+		msd, ok := messageSetMap[id]
+		if !ok {
+			// Unknown type; we can't render it, so skip it.
+			continue
+		}
+
+		if i > 0 && b.Len() > 1 {
+			b.WriteByte(',')
+		}
+
+		fmt.Fprintf(&b, `"[%s]":`, msd.name)
+
+		x := ext.value
+		if x == nil {
+			x = reflect.New(msd.t.Elem()).Interface()
+			if err := Unmarshal(ext.enc, x.(Message)); err != nil {
+				return nil, err
+			}
+		}
+		d, err := json.Marshal(x)
+		if err != nil {
+			return nil, err
+		}
+		b.Write(d)
+	}
+	b.WriteByte('}')
+	return b.Bytes(), nil
+}
+
+// UnmarshalMessageSetJSON decodes the extension map encoded in buf in JSON format.
+// It is called by generated UnmarshalJSON methods on protocol buffer messages with the message_set_wire_format option.
+func UnmarshalMessageSetJSON(buf []byte, exts interface{}) error {
+	// Common-case fast path.
+	if len(buf) == 0 || bytes.Equal(buf, []byte("{}")) {
+		return nil
+	}
+
+	// This is fairly tricky, and it's not clear that it is needed.
+	return errors.New("TODO: UnmarshalMessageSetJSON not yet implemented")
+}
+
+// A global registry of types that can be used in a MessageSet.
+
+var messageSetMap = make(map[int32]messageSetDesc)
+
+type messageSetDesc struct {
+	t    reflect.Type // pointer to struct
+	name string
+}
+
+// RegisterMessageSetType is called from the generated code.
+func RegisterMessageSetType(m Message, fieldNum int32, name string) {
+	messageSetMap[fieldNum] = messageSetDesc{
+		t:    reflect.TypeOf(m),
+		name: name,
+	}
+}
diff --git a/vendor/github.com/golang/protobuf/proto/pointer_reflect.go b/vendor/github.com/golang/protobuf/proto/pointer_reflect.go
new file mode 100644
index 0000000..b6cad90
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/pointer_reflect.go
@@ -0,0 +1,357 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2012 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// +build purego appengine js
+
+// This file contains an implementation of proto field accesses using package reflect.
+// It is slower than the code in pointer_unsafe.go but it avoids package unsafe and can
+// be used on App Engine.
+
+package proto
+
+import (
+	"reflect"
+	"sync"
+)
+
+const unsafeAllowed = false
+
+// A field identifies a field in a struct, accessible from a pointer.
+// In this implementation, a field is identified by the sequence of field indices
+// passed to reflect's FieldByIndex.
+type field []int
+
+// toField returns a field equivalent to the given reflect field.
+func toField(f *reflect.StructField) field {
+	return f.Index
+}
+
+// invalidField is an invalid field identifier.
+var invalidField = field(nil)
+
+// zeroField is a noop when calling pointer.offset.
+var zeroField = field([]int{})
+
+// IsValid reports whether the field identifier is valid.
+func (f field) IsValid() bool { return f != nil }
+
+// The pointer type is for the table-driven decoder.
+// The implementation here uses a reflect.Value of pointer type to
+// create a generic pointer. In pointer_unsafe.go we use unsafe
+// instead of reflect to implement the same (but faster) interface.
+type pointer struct {
+	v reflect.Value
+}
+
+// toPointer converts an interface of pointer type to a pointer
+// that points to the same target.
+func toPointer(i *Message) pointer {
+	return pointer{v: reflect.ValueOf(*i)}
+}
+
+// toAddrPointer converts an interface to a pointer that points to
+// the interface data.
+func toAddrPointer(i *interface{}, isptr bool) pointer {
+	v := reflect.ValueOf(*i)
+	u := reflect.New(v.Type())
+	u.Elem().Set(v)
+	return pointer{v: u}
+}
+
+// valToPointer converts v to a pointer.  v must be of pointer type.
+func valToPointer(v reflect.Value) pointer {
+	return pointer{v: v}
+}
+
+// offset converts from a pointer to a structure to a pointer to
+// one of its fields.
+func (p pointer) offset(f field) pointer {
+	return pointer{v: p.v.Elem().FieldByIndex(f).Addr()}
+}
+
+func (p pointer) isNil() bool {
+	return p.v.IsNil()
+}
+
+// grow updates the slice s in place to make it one element longer.
+// s must be addressable.
+// Returns the (addressable) new element.
+func grow(s reflect.Value) reflect.Value {
+	n, m := s.Len(), s.Cap()
+	if n < m {
+		s.SetLen(n + 1)
+	} else {
+		s.Set(reflect.Append(s, reflect.Zero(s.Type().Elem())))
+	}
+	return s.Index(n)
+}
+
+func (p pointer) toInt64() *int64 {
+	return p.v.Interface().(*int64)
+}
+func (p pointer) toInt64Ptr() **int64 {
+	return p.v.Interface().(**int64)
+}
+func (p pointer) toInt64Slice() *[]int64 {
+	return p.v.Interface().(*[]int64)
+}
+
+var int32ptr = reflect.TypeOf((*int32)(nil))
+
+func (p pointer) toInt32() *int32 {
+	return p.v.Convert(int32ptr).Interface().(*int32)
+}
+
+// The toInt32Ptr/Slice methods don't work because of enums.
+// Instead, we must use set/get methods for the int32ptr/slice case.
+/*
+	func (p pointer) toInt32Ptr() **int32 {
+		return p.v.Interface().(**int32)
+}
+	func (p pointer) toInt32Slice() *[]int32 {
+		return p.v.Interface().(*[]int32)
+}
+*/
+func (p pointer) getInt32Ptr() *int32 {
+	if p.v.Type().Elem().Elem() == reflect.TypeOf(int32(0)) {
+		// raw int32 type
+		return p.v.Elem().Interface().(*int32)
+	}
+	// an enum
+	return p.v.Elem().Convert(int32PtrType).Interface().(*int32)
+}
+func (p pointer) setInt32Ptr(v int32) {
+	// Allocate value in a *int32. Possibly convert that to a *enum.
+	// Then assign it to a **int32 or **enum.
+	// Note: we can convert *int32 to *enum, but we can't convert
+	// **int32 to **enum!
+	p.v.Elem().Set(reflect.ValueOf(&v).Convert(p.v.Type().Elem()))
+}
+
+// getInt32Slice copies []int32 from p as a new slice.
+// This behavior differs from the implementation in pointer_unsafe.go.
+func (p pointer) getInt32Slice() []int32 {
+	if p.v.Type().Elem().Elem() == reflect.TypeOf(int32(0)) {
+		// raw int32 type
+		return p.v.Elem().Interface().([]int32)
+	}
+	// an enum
+	// Allocate a []int32, then assign []enum's values into it.
+	// Note: we can't convert []enum to []int32.
+	slice := p.v.Elem()
+	s := make([]int32, slice.Len())
+	for i := 0; i < slice.Len(); i++ {
+		s[i] = int32(slice.Index(i).Int())
+	}
+	return s
+}
+
+// setInt32Slice copies []int32 into p as a new slice.
+// This behavior differs from the implementation in pointer_unsafe.go.
+func (p pointer) setInt32Slice(v []int32) {
+	if p.v.Type().Elem().Elem() == reflect.TypeOf(int32(0)) {
+		// raw int32 type
+		p.v.Elem().Set(reflect.ValueOf(v))
+		return
+	}
+	// an enum
+	// Allocate a []enum, then assign []int32's values into it.
+	// Note: we can't convert []enum to []int32.
+	slice := reflect.MakeSlice(p.v.Type().Elem(), len(v), cap(v))
+	for i, x := range v {
+		slice.Index(i).SetInt(int64(x))
+	}
+	p.v.Elem().Set(slice)
+}
+func (p pointer) appendInt32Slice(v int32) {
+	grow(p.v.Elem()).SetInt(int64(v))
+}
+
+func (p pointer) toUint64() *uint64 {
+	return p.v.Interface().(*uint64)
+}
+func (p pointer) toUint64Ptr() **uint64 {
+	return p.v.Interface().(**uint64)
+}
+func (p pointer) toUint64Slice() *[]uint64 {
+	return p.v.Interface().(*[]uint64)
+}
+func (p pointer) toUint32() *uint32 {
+	return p.v.Interface().(*uint32)
+}
+func (p pointer) toUint32Ptr() **uint32 {
+	return p.v.Interface().(**uint32)
+}
+func (p pointer) toUint32Slice() *[]uint32 {
+	return p.v.Interface().(*[]uint32)
+}
+func (p pointer) toBool() *bool {
+	return p.v.Interface().(*bool)
+}
+func (p pointer) toBoolPtr() **bool {
+	return p.v.Interface().(**bool)
+}
+func (p pointer) toBoolSlice() *[]bool {
+	return p.v.Interface().(*[]bool)
+}
+func (p pointer) toFloat64() *float64 {
+	return p.v.Interface().(*float64)
+}
+func (p pointer) toFloat64Ptr() **float64 {
+	return p.v.Interface().(**float64)
+}
+func (p pointer) toFloat64Slice() *[]float64 {
+	return p.v.Interface().(*[]float64)
+}
+func (p pointer) toFloat32() *float32 {
+	return p.v.Interface().(*float32)
+}
+func (p pointer) toFloat32Ptr() **float32 {
+	return p.v.Interface().(**float32)
+}
+func (p pointer) toFloat32Slice() *[]float32 {
+	return p.v.Interface().(*[]float32)
+}
+func (p pointer) toString() *string {
+	return p.v.Interface().(*string)
+}
+func (p pointer) toStringPtr() **string {
+	return p.v.Interface().(**string)
+}
+func (p pointer) toStringSlice() *[]string {
+	return p.v.Interface().(*[]string)
+}
+func (p pointer) toBytes() *[]byte {
+	return p.v.Interface().(*[]byte)
+}
+func (p pointer) toBytesSlice() *[][]byte {
+	return p.v.Interface().(*[][]byte)
+}
+func (p pointer) toExtensions() *XXX_InternalExtensions {
+	return p.v.Interface().(*XXX_InternalExtensions)
+}
+func (p pointer) toOldExtensions() *map[int32]Extension {
+	return p.v.Interface().(*map[int32]Extension)
+}
+func (p pointer) getPointer() pointer {
+	return pointer{v: p.v.Elem()}
+}
+func (p pointer) setPointer(q pointer) {
+	p.v.Elem().Set(q.v)
+}
+func (p pointer) appendPointer(q pointer) {
+	grow(p.v.Elem()).Set(q.v)
+}
+
+// getPointerSlice copies []*T from p as a new []pointer.
+// This behavior differs from the implementation in pointer_unsafe.go.
+func (p pointer) getPointerSlice() []pointer {
+	if p.v.IsNil() {
+		return nil
+	}
+	n := p.v.Elem().Len()
+	s := make([]pointer, n)
+	for i := 0; i < n; i++ {
+		s[i] = pointer{v: p.v.Elem().Index(i)}
+	}
+	return s
+}
+
+// setPointerSlice copies []pointer into p as a new []*T.
+// This behavior differs from the implementation in pointer_unsafe.go.
+func (p pointer) setPointerSlice(v []pointer) {
+	if v == nil {
+		p.v.Elem().Set(reflect.New(p.v.Elem().Type()).Elem())
+		return
+	}
+	s := reflect.MakeSlice(p.v.Elem().Type(), 0, len(v))
+	for _, p := range v {
+		s = reflect.Append(s, p.v)
+	}
+	p.v.Elem().Set(s)
+}
+
+// getInterfacePointer returns a pointer that points to the
+// interface data of the interface pointed by p.
+func (p pointer) getInterfacePointer() pointer {
+	if p.v.Elem().IsNil() {
+		return pointer{v: p.v.Elem()}
+	}
+	return pointer{v: p.v.Elem().Elem().Elem().Field(0).Addr()} // *interface -> interface -> *struct -> struct
+}
+
+func (p pointer) asPointerTo(t reflect.Type) reflect.Value {
+	// TODO: check that p.v.Type().Elem() == t?
+	return p.v
+}
+
+func atomicLoadUnmarshalInfo(p **unmarshalInfo) *unmarshalInfo {
+	atomicLock.Lock()
+	defer atomicLock.Unlock()
+	return *p
+}
+func atomicStoreUnmarshalInfo(p **unmarshalInfo, v *unmarshalInfo) {
+	atomicLock.Lock()
+	defer atomicLock.Unlock()
+	*p = v
+}
+func atomicLoadMarshalInfo(p **marshalInfo) *marshalInfo {
+	atomicLock.Lock()
+	defer atomicLock.Unlock()
+	return *p
+}
+func atomicStoreMarshalInfo(p **marshalInfo, v *marshalInfo) {
+	atomicLock.Lock()
+	defer atomicLock.Unlock()
+	*p = v
+}
+func atomicLoadMergeInfo(p **mergeInfo) *mergeInfo {
+	atomicLock.Lock()
+	defer atomicLock.Unlock()
+	return *p
+}
+func atomicStoreMergeInfo(p **mergeInfo, v *mergeInfo) {
+	atomicLock.Lock()
+	defer atomicLock.Unlock()
+	*p = v
+}
+func atomicLoadDiscardInfo(p **discardInfo) *discardInfo {
+	atomicLock.Lock()
+	defer atomicLock.Unlock()
+	return *p
+}
+func atomicStoreDiscardInfo(p **discardInfo, v *discardInfo) {
+	atomicLock.Lock()
+	defer atomicLock.Unlock()
+	*p = v
+}
+
+var atomicLock sync.Mutex
diff --git a/vendor/github.com/golang/protobuf/proto/pointer_unsafe.go b/vendor/github.com/golang/protobuf/proto/pointer_unsafe.go
new file mode 100644
index 0000000..d55a335
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/pointer_unsafe.go
@@ -0,0 +1,308 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2012 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// +build !purego,!appengine,!js
+
+// This file contains the implementation of the proto field accesses using package unsafe.
+
+package proto
+
+import (
+	"reflect"
+	"sync/atomic"
+	"unsafe"
+)
+
+const unsafeAllowed = true
+
+// A field identifies a field in a struct, accessible from a pointer.
+// In this implementation, a field is identified by its byte offset from the start of the struct.
+type field uintptr
+
+// toField returns a field equivalent to the given reflect field.
+func toField(f *reflect.StructField) field {
+	return field(f.Offset)
+}
+
+// invalidField is an invalid field identifier.
+const invalidField = ^field(0)
+
+// zeroField is a noop when calling pointer.offset.
+const zeroField = field(0)
+
+// IsValid reports whether the field identifier is valid.
+func (f field) IsValid() bool {
+	return f != invalidField
+}
+
+// The pointer type below is for the new table-driven encoder/decoder.
+// The implementation here uses unsafe.Pointer to create a generic pointer.
+// In pointer_reflect.go we use reflect instead of unsafe to implement
+// the same (but slower) interface.
+type pointer struct {
+	p unsafe.Pointer
+}
+
+// size of pointer
+var ptrSize = unsafe.Sizeof(uintptr(0))
+
+// toPointer converts an interface of pointer type to a pointer
+// that points to the same target.
+func toPointer(i *Message) pointer {
+	// Super-tricky - read pointer out of data word of interface value.
+	// Saves ~25ns over the equivalent:
+	// return valToPointer(reflect.ValueOf(*i))
+	return pointer{p: (*[2]unsafe.Pointer)(unsafe.Pointer(i))[1]}
+}
+
+// toAddrPointer converts an interface to a pointer that points to
+// the interface data.
+func toAddrPointer(i *interface{}, isptr bool) pointer {
+	// Super-tricky - read or get the address of data word of interface value.
+	if isptr {
+		// The interface is of pointer type, thus it is a direct interface.
+		// The data word is the pointer data itself. We take its address.
+		return pointer{p: unsafe.Pointer(uintptr(unsafe.Pointer(i)) + ptrSize)}
+	}
+	// The interface is not of pointer type. The data word is the pointer
+	// to the data.
+	return pointer{p: (*[2]unsafe.Pointer)(unsafe.Pointer(i))[1]}
+}
+
+// valToPointer converts v to a pointer. v must be of pointer type.
+func valToPointer(v reflect.Value) pointer {
+	return pointer{p: unsafe.Pointer(v.Pointer())}
+}
+
+// offset converts from a pointer to a structure to a pointer to
+// one of its fields.
+func (p pointer) offset(f field) pointer {
+	// For safety, we should panic if !f.IsValid, however calling panic causes
+	// this to no longer be inlineable, which is a serious performance cost.
+	/*
+		if !f.IsValid() {
+			panic("invalid field")
+		}
+	*/
+	return pointer{p: unsafe.Pointer(uintptr(p.p) + uintptr(f))}
+}
+
+func (p pointer) isNil() bool {
+	return p.p == nil
+}
+
+func (p pointer) toInt64() *int64 {
+	return (*int64)(p.p)
+}
+func (p pointer) toInt64Ptr() **int64 {
+	return (**int64)(p.p)
+}
+func (p pointer) toInt64Slice() *[]int64 {
+	return (*[]int64)(p.p)
+}
+func (p pointer) toInt32() *int32 {
+	return (*int32)(p.p)
+}
+
+// See pointer_reflect.go for why toInt32Ptr/Slice doesn't exist.
+/*
+	func (p pointer) toInt32Ptr() **int32 {
+		return (**int32)(p.p)
+	}
+	func (p pointer) toInt32Slice() *[]int32 {
+		return (*[]int32)(p.p)
+	}
+*/
+func (p pointer) getInt32Ptr() *int32 {
+	return *(**int32)(p.p)
+}
+func (p pointer) setInt32Ptr(v int32) {
+	*(**int32)(p.p) = &v
+}
+
+// getInt32Slice loads a []int32 from p.
+// The value returned is aliased with the original slice.
+// This behavior differs from the implementation in pointer_reflect.go.
+func (p pointer) getInt32Slice() []int32 {
+	return *(*[]int32)(p.p)
+}
+
+// setInt32Slice stores a []int32 to p.
+// The value set is aliased with the input slice.
+// This behavior differs from the implementation in pointer_reflect.go.
+func (p pointer) setInt32Slice(v []int32) {
+	*(*[]int32)(p.p) = v
+}
+
+// TODO: Can we get rid of appendInt32Slice and use setInt32Slice instead?
+func (p pointer) appendInt32Slice(v int32) {
+	s := (*[]int32)(p.p)
+	*s = append(*s, v)
+}
+
+func (p pointer) toUint64() *uint64 {
+	return (*uint64)(p.p)
+}
+func (p pointer) toUint64Ptr() **uint64 {
+	return (**uint64)(p.p)
+}
+func (p pointer) toUint64Slice() *[]uint64 {
+	return (*[]uint64)(p.p)
+}
+func (p pointer) toUint32() *uint32 {
+	return (*uint32)(p.p)
+}
+func (p pointer) toUint32Ptr() **uint32 {
+	return (**uint32)(p.p)
+}
+func (p pointer) toUint32Slice() *[]uint32 {
+	return (*[]uint32)(p.p)
+}
+func (p pointer) toBool() *bool {
+	return (*bool)(p.p)
+}
+func (p pointer) toBoolPtr() **bool {
+	return (**bool)(p.p)
+}
+func (p pointer) toBoolSlice() *[]bool {
+	return (*[]bool)(p.p)
+}
+func (p pointer) toFloat64() *float64 {
+	return (*float64)(p.p)
+}
+func (p pointer) toFloat64Ptr() **float64 {
+	return (**float64)(p.p)
+}
+func (p pointer) toFloat64Slice() *[]float64 {
+	return (*[]float64)(p.p)
+}
+func (p pointer) toFloat32() *float32 {
+	return (*float32)(p.p)
+}
+func (p pointer) toFloat32Ptr() **float32 {
+	return (**float32)(p.p)
+}
+func (p pointer) toFloat32Slice() *[]float32 {
+	return (*[]float32)(p.p)
+}
+func (p pointer) toString() *string {
+	return (*string)(p.p)
+}
+func (p pointer) toStringPtr() **string {
+	return (**string)(p.p)
+}
+func (p pointer) toStringSlice() *[]string {
+	return (*[]string)(p.p)
+}
+func (p pointer) toBytes() *[]byte {
+	return (*[]byte)(p.p)
+}
+func (p pointer) toBytesSlice() *[][]byte {
+	return (*[][]byte)(p.p)
+}
+func (p pointer) toExtensions() *XXX_InternalExtensions {
+	return (*XXX_InternalExtensions)(p.p)
+}
+func (p pointer) toOldExtensions() *map[int32]Extension {
+	return (*map[int32]Extension)(p.p)
+}
+
+// getPointerSlice loads []*T from p as a []pointer.
+// The value returned is aliased with the original slice.
+// This behavior differs from the implementation in pointer_reflect.go.
+func (p pointer) getPointerSlice() []pointer {
+	// Super-tricky - p should point to a []*T where T is a
+	// message type. We load it as []pointer.
+	return *(*[]pointer)(p.p)
+}
+
+// setPointerSlice stores []pointer into p as a []*T.
+// The value set is aliased with the input slice.
+// This behavior differs from the implementation in pointer_reflect.go.
+func (p pointer) setPointerSlice(v []pointer) {
+	// Super-tricky - p should point to a []*T where T is a
+	// message type. We store it as []pointer.
+	*(*[]pointer)(p.p) = v
+}
+
+// getPointer loads the pointer at p and returns it.
+func (p pointer) getPointer() pointer {
+	return pointer{p: *(*unsafe.Pointer)(p.p)}
+}
+
+// setPointer stores the pointer q at p.
+func (p pointer) setPointer(q pointer) {
+	*(*unsafe.Pointer)(p.p) = q.p
+}
+
+// append q to the slice pointed to by p.
+func (p pointer) appendPointer(q pointer) {
+	s := (*[]unsafe.Pointer)(p.p)
+	*s = append(*s, q.p)
+}
+
+// getInterfacePointer returns a pointer that points to the
+// interface data of the interface pointed by p.
+func (p pointer) getInterfacePointer() pointer {
+	// Super-tricky - read pointer out of data word of interface value.
+	return pointer{p: (*(*[2]unsafe.Pointer)(p.p))[1]}
+}
+
+// asPointerTo returns a reflect.Value that is a pointer to an
+// object of type t stored at p.
+func (p pointer) asPointerTo(t reflect.Type) reflect.Value {
+	return reflect.NewAt(t, p.p)
+}
+
+func atomicLoadUnmarshalInfo(p **unmarshalInfo) *unmarshalInfo {
+	return (*unmarshalInfo)(atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(p))))
+}
+func atomicStoreUnmarshalInfo(p **unmarshalInfo, v *unmarshalInfo) {
+	atomic.StorePointer((*unsafe.Pointer)(unsafe.Pointer(p)), unsafe.Pointer(v))
+}
+func atomicLoadMarshalInfo(p **marshalInfo) *marshalInfo {
+	return (*marshalInfo)(atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(p))))
+}
+func atomicStoreMarshalInfo(p **marshalInfo, v *marshalInfo) {
+	atomic.StorePointer((*unsafe.Pointer)(unsafe.Pointer(p)), unsafe.Pointer(v))
+}
+func atomicLoadMergeInfo(p **mergeInfo) *mergeInfo {
+	return (*mergeInfo)(atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(p))))
+}
+func atomicStoreMergeInfo(p **mergeInfo, v *mergeInfo) {
+	atomic.StorePointer((*unsafe.Pointer)(unsafe.Pointer(p)), unsafe.Pointer(v))
+}
+func atomicLoadDiscardInfo(p **discardInfo) *discardInfo {
+	return (*discardInfo)(atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(p))))
+}
+func atomicStoreDiscardInfo(p **discardInfo, v *discardInfo) {
+	atomic.StorePointer((*unsafe.Pointer)(unsafe.Pointer(p)), unsafe.Pointer(v))
+}
diff --git a/vendor/github.com/golang/protobuf/proto/properties.go b/vendor/github.com/golang/protobuf/proto/properties.go
new file mode 100644
index 0000000..50b99b8
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/properties.go
@@ -0,0 +1,544 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2010 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package proto
+
+/*
+ * Routines for encoding data into the wire format for protocol buffers.
+ */
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"reflect"
+	"sort"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+const debug bool = false
+
+// Constants that identify the encoding of a value on the wire.
+const (
+	WireVarint     = 0
+	WireFixed64    = 1
+	WireBytes      = 2
+	WireStartGroup = 3
+	WireEndGroup   = 4
+	WireFixed32    = 5
+)
+
+// tagMap is an optimization over map[int]int for typical protocol buffer
+// use-cases. Encoded protocol buffers are often in tag order with small tag
+// numbers.
+type tagMap struct {
+	fastTags []int
+	slowTags map[int]int
+}
+
+// tagMapFastLimit is the upper bound on the tag number that will be stored in
+// the tagMap slice rather than its map.
+const tagMapFastLimit = 1024
+
+func (p *tagMap) get(t int) (int, bool) {
+	if t > 0 && t < tagMapFastLimit {
+		if t >= len(p.fastTags) {
+			return 0, false
+		}
+		fi := p.fastTags[t]
+		return fi, fi >= 0
+	}
+	fi, ok := p.slowTags[t]
+	return fi, ok
+}
+
+func (p *tagMap) put(t int, fi int) {
+	if t > 0 && t < tagMapFastLimit {
+		for len(p.fastTags) < t+1 {
+			p.fastTags = append(p.fastTags, -1)
+		}
+		p.fastTags[t] = fi
+		return
+	}
+	if p.slowTags == nil {
+		p.slowTags = make(map[int]int)
+	}
+	p.slowTags[t] = fi
+}
+
+// StructProperties represents properties for all the fields of a struct.
+// decoderTags and decoderOrigNames should only be used by the decoder.
+type StructProperties struct {
+	Prop             []*Properties  // properties for each field
+	reqCount         int            // required count
+	decoderTags      tagMap         // map from proto tag to struct field number
+	decoderOrigNames map[string]int // map from original name to struct field number
+	order            []int          // list of struct field numbers in tag order
+
+	// OneofTypes contains information about the oneof fields in this message.
+	// It is keyed by the original name of a field.
+	OneofTypes map[string]*OneofProperties
+}
+
+// OneofProperties represents information about a specific field in a oneof.
+type OneofProperties struct {
+	Type  reflect.Type // pointer to generated struct type for this oneof field
+	Field int          // struct field number of the containing oneof in the message
+	Prop  *Properties
+}
+
+// Implement the sorting interface so we can sort the fields in tag order, as recommended by the spec.
+// See encode.go, (*Buffer).enc_struct.
+
+func (sp *StructProperties) Len() int { return len(sp.order) }
+func (sp *StructProperties) Less(i, j int) bool {
+	return sp.Prop[sp.order[i]].Tag < sp.Prop[sp.order[j]].Tag
+}
+func (sp *StructProperties) Swap(i, j int) { sp.order[i], sp.order[j] = sp.order[j], sp.order[i] }
+
+// Properties represents the protocol-specific behavior of a single struct field.
+type Properties struct {
+	Name     string // name of the field, for error messages
+	OrigName string // original name before protocol compiler (always set)
+	JSONName string // name to use for JSON; determined by protoc
+	Wire     string
+	WireType int
+	Tag      int
+	Required bool
+	Optional bool
+	Repeated bool
+	Packed   bool   // relevant for repeated primitives only
+	Enum     string // set for enum types only
+	proto3   bool   // whether this is known to be a proto3 field
+	oneof    bool   // whether this is a oneof field
+
+	Default    string // default value
+	HasDefault bool   // whether an explicit default was provided
+
+	stype reflect.Type      // set for struct types only
+	sprop *StructProperties // set for struct types only
+
+	mtype      reflect.Type // set for map types only
+	MapKeyProp *Properties  // set for map types only
+	MapValProp *Properties  // set for map types only
+}
+
+// String formats the properties in the protobuf struct field tag style.
+func (p *Properties) String() string {
+	s := p.Wire
+	s += ","
+	s += strconv.Itoa(p.Tag)
+	if p.Required {
+		s += ",req"
+	}
+	if p.Optional {
+		s += ",opt"
+	}
+	if p.Repeated {
+		s += ",rep"
+	}
+	if p.Packed {
+		s += ",packed"
+	}
+	s += ",name=" + p.OrigName
+	if p.JSONName != p.OrigName {
+		s += ",json=" + p.JSONName
+	}
+	if p.proto3 {
+		s += ",proto3"
+	}
+	if p.oneof {
+		s += ",oneof"
+	}
+	if len(p.Enum) > 0 {
+		s += ",enum=" + p.Enum
+	}
+	if p.HasDefault {
+		s += ",def=" + p.Default
+	}
+	return s
+}
+
+// Parse populates p by parsing a string in the protobuf struct field tag style.
+func (p *Properties) Parse(s string) {
+	// "bytes,49,opt,name=foo,def=hello!"
+	fields := strings.Split(s, ",") // breaks def=, but handled below.
+	if len(fields) < 2 {
+		fmt.Fprintf(os.Stderr, "proto: tag has too few fields: %q\n", s)
+		return
+	}
+
+	p.Wire = fields[0]
+	switch p.Wire {
+	case "varint":
+		p.WireType = WireVarint
+	case "fixed32":
+		p.WireType = WireFixed32
+	case "fixed64":
+		p.WireType = WireFixed64
+	case "zigzag32":
+		p.WireType = WireVarint
+	case "zigzag64":
+		p.WireType = WireVarint
+	case "bytes", "group":
+		p.WireType = WireBytes
+		// no numeric converter for non-numeric types
+	default:
+		fmt.Fprintf(os.Stderr, "proto: tag has unknown wire type: %q\n", s)
+		return
+	}
+
+	var err error
+	p.Tag, err = strconv.Atoi(fields[1])
+	if err != nil {
+		return
+	}
+
+outer:
+	for i := 2; i < len(fields); i++ {
+		f := fields[i]
+		switch {
+		case f == "req":
+			p.Required = true
+		case f == "opt":
+			p.Optional = true
+		case f == "rep":
+			p.Repeated = true
+		case f == "packed":
+			p.Packed = true
+		case strings.HasPrefix(f, "name="):
+			p.OrigName = f[5:]
+		case strings.HasPrefix(f, "json="):
+			p.JSONName = f[5:]
+		case strings.HasPrefix(f, "enum="):
+			p.Enum = f[5:]
+		case f == "proto3":
+			p.proto3 = true
+		case f == "oneof":
+			p.oneof = true
+		case strings.HasPrefix(f, "def="):
+			p.HasDefault = true
+			p.Default = f[4:] // rest of string
+			if i+1 < len(fields) {
+				// Commas aren't escaped, and def is always last.
+				p.Default += "," + strings.Join(fields[i+1:], ",")
+				break outer
+			}
+		}
+	}
+}
+
+var protoMessageType = reflect.TypeOf((*Message)(nil)).Elem()
+
+// setFieldProps initializes the field properties for submessages and maps.
+func (p *Properties) setFieldProps(typ reflect.Type, f *reflect.StructField, lockGetProp bool) {
+	switch t1 := typ; t1.Kind() {
+	case reflect.Ptr:
+		if t1.Elem().Kind() == reflect.Struct {
+			p.stype = t1.Elem()
+		}
+
+	case reflect.Slice:
+		if t2 := t1.Elem(); t2.Kind() == reflect.Ptr && t2.Elem().Kind() == reflect.Struct {
+			p.stype = t2.Elem()
+		}
+
+	case reflect.Map:
+		p.mtype = t1
+		p.MapKeyProp = &Properties{}
+		p.MapKeyProp.init(reflect.PtrTo(p.mtype.Key()), "Key", f.Tag.Get("protobuf_key"), nil, lockGetProp)
+		p.MapValProp = &Properties{}
+		vtype := p.mtype.Elem()
+		if vtype.Kind() != reflect.Ptr && vtype.Kind() != reflect.Slice {
+			// The value type is not a message (*T) or bytes ([]byte),
+			// so we need encoders for the pointer to this type.
+			vtype = reflect.PtrTo(vtype)
+		}
+		p.MapValProp.init(vtype, "Value", f.Tag.Get("protobuf_val"), nil, lockGetProp)
+	}
+
+	if p.stype != nil {
+		if lockGetProp {
+			p.sprop = GetProperties(p.stype)
+		} else {
+			p.sprop = getPropertiesLocked(p.stype)
+		}
+	}
+}
+
+var (
+	marshalerType = reflect.TypeOf((*Marshaler)(nil)).Elem()
+)
+
+// Init populates the properties from a protocol buffer struct tag.
+func (p *Properties) Init(typ reflect.Type, name, tag string, f *reflect.StructField) {
+	p.init(typ, name, tag, f, true)
+}
+
+func (p *Properties) init(typ reflect.Type, name, tag string, f *reflect.StructField, lockGetProp bool) {
+	// "bytes,49,opt,def=hello!"
+	p.Name = name
+	p.OrigName = name
+	if tag == "" {
+		return
+	}
+	p.Parse(tag)
+	p.setFieldProps(typ, f, lockGetProp)
+}
+
+var (
+	propertiesMu  sync.RWMutex
+	propertiesMap = make(map[reflect.Type]*StructProperties)
+)
+
+// GetProperties returns the list of properties for the type represented by t.
+// t must represent a generated struct type of a protocol message.
+func GetProperties(t reflect.Type) *StructProperties {
+	if t.Kind() != reflect.Struct {
+		panic("proto: type must have kind struct")
+	}
+
+	// Most calls to GetProperties in a long-running program will be
+	// retrieving details for types we have seen before.
+	propertiesMu.RLock()
+	sprop, ok := propertiesMap[t]
+	propertiesMu.RUnlock()
+	if ok {
+		if collectStats {
+			stats.Chit++
+		}
+		return sprop
+	}
+
+	propertiesMu.Lock()
+	sprop = getPropertiesLocked(t)
+	propertiesMu.Unlock()
+	return sprop
+}
+
+// getPropertiesLocked requires that propertiesMu is held.
+func getPropertiesLocked(t reflect.Type) *StructProperties {
+	if prop, ok := propertiesMap[t]; ok {
+		if collectStats {
+			stats.Chit++
+		}
+		return prop
+	}
+	if collectStats {
+		stats.Cmiss++
+	}
+
+	prop := new(StructProperties)
+	// in case of recursive protos, fill this in now.
+	propertiesMap[t] = prop
+
+	// build properties
+	prop.Prop = make([]*Properties, t.NumField())
+	prop.order = make([]int, t.NumField())
+
+	for i := 0; i < t.NumField(); i++ {
+		f := t.Field(i)
+		p := new(Properties)
+		name := f.Name
+		p.init(f.Type, name, f.Tag.Get("protobuf"), &f, false)
+
+		oneof := f.Tag.Get("protobuf_oneof") // special case
+		if oneof != "" {
+			// Oneof fields don't use the traditional protobuf tag.
+			p.OrigName = oneof
+		}
+		prop.Prop[i] = p
+		prop.order[i] = i
+		if debug {
+			print(i, " ", f.Name, " ", t.String(), " ")
+			if p.Tag > 0 {
+				print(p.String())
+			}
+			print("\n")
+		}
+	}
+
+	// Re-order prop.order.
+	sort.Sort(prop)
+
+	type oneofMessage interface {
+		XXX_OneofFuncs() (func(Message, *Buffer) error, func(Message, int, int, *Buffer) (bool, error), func(Message) int, []interface{})
+	}
+	if om, ok := reflect.Zero(reflect.PtrTo(t)).Interface().(oneofMessage); ok {
+		var oots []interface{}
+		_, _, _, oots = om.XXX_OneofFuncs()
+
+		// Interpret oneof metadata.
+		prop.OneofTypes = make(map[string]*OneofProperties)
+		for _, oot := range oots {
+			oop := &OneofProperties{
+				Type: reflect.ValueOf(oot).Type(), // *T
+				Prop: new(Properties),
+			}
+			sft := oop.Type.Elem().Field(0)
+			oop.Prop.Name = sft.Name
+			oop.Prop.Parse(sft.Tag.Get("protobuf"))
+			// There will be exactly one interface field that
+			// this new value is assignable to.
+			for i := 0; i < t.NumField(); i++ {
+				f := t.Field(i)
+				if f.Type.Kind() != reflect.Interface {
+					continue
+				}
+				if !oop.Type.AssignableTo(f.Type) {
+					continue
+				}
+				oop.Field = i
+				break
+			}
+			prop.OneofTypes[oop.Prop.OrigName] = oop
+		}
+	}
+
+	// build required counts
+	// build tags
+	reqCount := 0
+	prop.decoderOrigNames = make(map[string]int)
+	for i, p := range prop.Prop {
+		if strings.HasPrefix(p.Name, "XXX_") {
+			// Internal fields should not appear in tags/origNames maps.
+			// They are handled specially when encoding and decoding.
+			continue
+		}
+		if p.Required {
+			reqCount++
+		}
+		prop.decoderTags.put(p.Tag, i)
+		prop.decoderOrigNames[p.OrigName] = i
+	}
+	prop.reqCount = reqCount
+
+	return prop
+}
+
+// A global registry of enum types.
+// The generated code will register the generated maps by calling RegisterEnum.
+
+var enumValueMaps = make(map[string]map[string]int32)
+
+// RegisterEnum is called from the generated code to install the enum descriptor
+// maps into the global table to aid parsing text format protocol buffers.
+func RegisterEnum(typeName string, unusedNameMap map[int32]string, valueMap map[string]int32) {
+	if _, ok := enumValueMaps[typeName]; ok {
+		panic("proto: duplicate enum registered: " + typeName)
+	}
+	enumValueMaps[typeName] = valueMap
+}
+
+// EnumValueMap returns the mapping from names to integers of the
+// enum type enumType, or a nil if not found.
+func EnumValueMap(enumType string) map[string]int32 {
+	return enumValueMaps[enumType]
+}
+
+// A registry of all linked message types.
+// The string is a fully-qualified proto name ("pkg.Message").
+var (
+	protoTypedNils = make(map[string]Message)      // a map from proto names to typed nil pointers
+	protoMapTypes  = make(map[string]reflect.Type) // a map from proto names to map types
+	revProtoTypes  = make(map[reflect.Type]string)
+)
+
+// RegisterType is called from generated code and maps from the fully qualified
+// proto name to the type (pointer to struct) of the protocol buffer.
+func RegisterType(x Message, name string) {
+	if _, ok := protoTypedNils[name]; ok {
+		// TODO: Some day, make this a panic.
+		log.Printf("proto: duplicate proto type registered: %s", name)
+		return
+	}
+	t := reflect.TypeOf(x)
+	if v := reflect.ValueOf(x); v.Kind() == reflect.Ptr && v.Pointer() == 0 {
+		// Generated code always calls RegisterType with nil x.
+		// This check is just for extra safety.
+		protoTypedNils[name] = x
+	} else {
+		protoTypedNils[name] = reflect.Zero(t).Interface().(Message)
+	}
+	revProtoTypes[t] = name
+}
+
+// RegisterMapType is called from generated code and maps from the fully qualified
+// proto name to the native map type of the proto map definition.
+func RegisterMapType(x interface{}, name string) {
+	if reflect.TypeOf(x).Kind() != reflect.Map {
+		panic(fmt.Sprintf("RegisterMapType(%T, %q); want map", x, name))
+	}
+	if _, ok := protoMapTypes[name]; ok {
+		log.Printf("proto: duplicate proto type registered: %s", name)
+		return
+	}
+	t := reflect.TypeOf(x)
+	protoMapTypes[name] = t
+	revProtoTypes[t] = name
+}
+
+// MessageName returns the fully-qualified proto name for the given message type.
+func MessageName(x Message) string {
+	type xname interface {
+		XXX_MessageName() string
+	}
+	if m, ok := x.(xname); ok {
+		return m.XXX_MessageName()
+	}
+	return revProtoTypes[reflect.TypeOf(x)]
+}
+
+// MessageType returns the message type (pointer to struct) for a named message.
+// The type is not guaranteed to implement proto.Message if the name refers to a
+// map entry.
+func MessageType(name string) reflect.Type {
+	if t, ok := protoTypedNils[name]; ok {
+		return reflect.TypeOf(t)
+	}
+	return protoMapTypes[name]
+}
+
+// A registry of all linked proto files.
+var (
+	protoFiles = make(map[string][]byte) // file name => fileDescriptor
+)
+
+// RegisterFile is called from generated code and maps from the
+// full file name of a .proto file to its compressed FileDescriptorProto.
+func RegisterFile(filename string, fileDescriptor []byte) {
+	protoFiles[filename] = fileDescriptor
+}
+
+// FileDescriptor returns the compressed FileDescriptorProto for a .proto file.
+func FileDescriptor(filename string) []byte { return protoFiles[filename] }
diff --git a/vendor/github.com/golang/protobuf/proto/table_marshal.go b/vendor/github.com/golang/protobuf/proto/table_marshal.go
new file mode 100644
index 0000000..b167944
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/table_marshal.go
@@ -0,0 +1,2767 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2016 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package proto
+
+import (
+	"errors"
+	"fmt"
+	"math"
+	"reflect"
+	"sort"
+	"strconv"
+	"strings"
+	"sync"
+	"sync/atomic"
+	"unicode/utf8"
+)
+
+// a sizer takes a pointer to a field and the size of its tag, computes the size of
+// the encoded data.
+type sizer func(pointer, int) int
+
+// a marshaler takes a byte slice, a pointer to a field, and its tag (in wire format),
+// marshals the field to the end of the slice, returns the slice and error (if any).
+type marshaler func(b []byte, ptr pointer, wiretag uint64, deterministic bool) ([]byte, error)
+
+// marshalInfo is the information used for marshaling a message.
+type marshalInfo struct {
+	typ          reflect.Type
+	fields       []*marshalFieldInfo
+	unrecognized field                      // offset of XXX_unrecognized
+	extensions   field                      // offset of XXX_InternalExtensions
+	v1extensions field                      // offset of XXX_extensions
+	sizecache    field                      // offset of XXX_sizecache
+	initialized  int32                      // 0 -- only typ is set, 1 -- fully initialized
+	messageset   bool                       // uses message set wire format
+	hasmarshaler bool                       // has custom marshaler
+	sync.RWMutex                            // protect extElems map, also for initialization
+	extElems     map[int32]*marshalElemInfo // info of extension elements
+}
+
+// marshalFieldInfo is the information used for marshaling a field of a message.
+type marshalFieldInfo struct {
+	field      field
+	wiretag    uint64 // tag in wire format
+	tagsize    int    // size of tag in wire format
+	sizer      sizer
+	marshaler  marshaler
+	isPointer  bool
+	required   bool                              // field is required
+	name       string                            // name of the field, for error reporting
+	oneofElems map[reflect.Type]*marshalElemInfo // info of oneof elements
+}
+
+// marshalElemInfo is the information used for marshaling an extension or oneof element.
+type marshalElemInfo struct {
+	wiretag   uint64 // tag in wire format
+	tagsize   int    // size of tag in wire format
+	sizer     sizer
+	marshaler marshaler
+	isptr     bool // elem is pointer typed, thus interface of this type is a direct interface (extension only)
+}
+
+var (
+	marshalInfoMap  = map[reflect.Type]*marshalInfo{}
+	marshalInfoLock sync.Mutex
+)
+
+// getMarshalInfo returns the information to marshal a given type of message.
+// The info it returns may not necessarily initialized.
+// t is the type of the message (NOT the pointer to it).
+func getMarshalInfo(t reflect.Type) *marshalInfo {
+	marshalInfoLock.Lock()
+	u, ok := marshalInfoMap[t]
+	if !ok {
+		u = &marshalInfo{typ: t}
+		marshalInfoMap[t] = u
+	}
+	marshalInfoLock.Unlock()
+	return u
+}
+
+// Size is the entry point from generated code,
+// and should be ONLY called by generated code.
+// It computes the size of encoded data of msg.
+// a is a pointer to a place to store cached marshal info.
+func (a *InternalMessageInfo) Size(msg Message) int {
+	u := getMessageMarshalInfo(msg, a)
+	ptr := toPointer(&msg)
+	if ptr.isNil() {
+		// We get here if msg is a typed nil ((*SomeMessage)(nil)),
+		// so it satisfies the interface, and msg == nil wouldn't
+		// catch it. We don't want crash in this case.
+		return 0
+	}
+	return u.size(ptr)
+}
+
+// Marshal is the entry point from generated code,
+// and should be ONLY called by generated code.
+// It marshals msg to the end of b.
+// a is a pointer to a place to store cached marshal info.
+func (a *InternalMessageInfo) Marshal(b []byte, msg Message, deterministic bool) ([]byte, error) {
+	u := getMessageMarshalInfo(msg, a)
+	ptr := toPointer(&msg)
+	if ptr.isNil() {
+		// We get here if msg is a typed nil ((*SomeMessage)(nil)),
+		// so it satisfies the interface, and msg == nil wouldn't
+		// catch it. We don't want crash in this case.
+		return b, ErrNil
+	}
+	return u.marshal(b, ptr, deterministic)
+}
+
+func getMessageMarshalInfo(msg interface{}, a *InternalMessageInfo) *marshalInfo {
+	// u := a.marshal, but atomically.
+	// We use an atomic here to ensure memory consistency.
+	u := atomicLoadMarshalInfo(&a.marshal)
+	if u == nil {
+		// Get marshal information from type of message.
+		t := reflect.ValueOf(msg).Type()
+		if t.Kind() != reflect.Ptr {
+			panic(fmt.Sprintf("cannot handle non-pointer message type %v", t))
+		}
+		u = getMarshalInfo(t.Elem())
+		// Store it in the cache for later users.
+		// a.marshal = u, but atomically.
+		atomicStoreMarshalInfo(&a.marshal, u)
+	}
+	return u
+}
+
+// size is the main function to compute the size of the encoded data of a message.
+// ptr is the pointer to the message.
+func (u *marshalInfo) size(ptr pointer) int {
+	if atomic.LoadInt32(&u.initialized) == 0 {
+		u.computeMarshalInfo()
+	}
+
+	// If the message can marshal itself, let it do it, for compatibility.
+	// NOTE: This is not efficient.
+	if u.hasmarshaler {
+		m := ptr.asPointerTo(u.typ).Interface().(Marshaler)
+		b, _ := m.Marshal()
+		return len(b)
+	}
+
+	n := 0
+	for _, f := range u.fields {
+		if f.isPointer && ptr.offset(f.field).getPointer().isNil() {
+			// nil pointer always marshals to nothing
+			continue
+		}
+		n += f.sizer(ptr.offset(f.field), f.tagsize)
+	}
+	if u.extensions.IsValid() {
+		e := ptr.offset(u.extensions).toExtensions()
+		if u.messageset {
+			n += u.sizeMessageSet(e)
+		} else {
+			n += u.sizeExtensions(e)
+		}
+	}
+	if u.v1extensions.IsValid() {
+		m := *ptr.offset(u.v1extensions).toOldExtensions()
+		n += u.sizeV1Extensions(m)
+	}
+	if u.unrecognized.IsValid() {
+		s := *ptr.offset(u.unrecognized).toBytes()
+		n += len(s)
+	}
+	// cache the result for use in marshal
+	if u.sizecache.IsValid() {
+		atomic.StoreInt32(ptr.offset(u.sizecache).toInt32(), int32(n))
+	}
+	return n
+}
+
+// cachedsize gets the size from cache. If there is no cache (i.e. message is not generated),
+// fall back to compute the size.
+func (u *marshalInfo) cachedsize(ptr pointer) int {
+	if u.sizecache.IsValid() {
+		return int(atomic.LoadInt32(ptr.offset(u.sizecache).toInt32()))
+	}
+	return u.size(ptr)
+}
+
+// marshal is the main function to marshal a message. It takes a byte slice and appends
+// the encoded data to the end of the slice, returns the slice and error (if any).
+// ptr is the pointer to the message.
+// If deterministic is true, map is marshaled in deterministic order.
+func (u *marshalInfo) marshal(b []byte, ptr pointer, deterministic bool) ([]byte, error) {
+	if atomic.LoadInt32(&u.initialized) == 0 {
+		u.computeMarshalInfo()
+	}
+
+	// If the message can marshal itself, let it do it, for compatibility.
+	// NOTE: This is not efficient.
+	if u.hasmarshaler {
+		m := ptr.asPointerTo(u.typ).Interface().(Marshaler)
+		b1, err := m.Marshal()
+		b = append(b, b1...)
+		return b, err
+	}
+
+	var err, errLater error
+	// The old marshaler encodes extensions at beginning.
+	if u.extensions.IsValid() {
+		e := ptr.offset(u.extensions).toExtensions()
+		if u.messageset {
+			b, err = u.appendMessageSet(b, e, deterministic)
+		} else {
+			b, err = u.appendExtensions(b, e, deterministic)
+		}
+		if err != nil {
+			return b, err
+		}
+	}
+	if u.v1extensions.IsValid() {
+		m := *ptr.offset(u.v1extensions).toOldExtensions()
+		b, err = u.appendV1Extensions(b, m, deterministic)
+		if err != nil {
+			return b, err
+		}
+	}
+	for _, f := range u.fields {
+		if f.required {
+			if ptr.offset(f.field).getPointer().isNil() {
+				// Required field is not set.
+				// We record the error but keep going, to give a complete marshaling.
+				if errLater == nil {
+					errLater = &RequiredNotSetError{f.name}
+				}
+				continue
+			}
+		}
+		if f.isPointer && ptr.offset(f.field).getPointer().isNil() {
+			// nil pointer always marshals to nothing
+			continue
+		}
+		b, err = f.marshaler(b, ptr.offset(f.field), f.wiretag, deterministic)
+		if err != nil {
+			if err1, ok := err.(*RequiredNotSetError); ok {
+				// Required field in submessage is not set.
+				// We record the error but keep going, to give a complete marshaling.
+				if errLater == nil {
+					errLater = &RequiredNotSetError{f.name + "." + err1.field}
+				}
+				continue
+			}
+			if err == errRepeatedHasNil {
+				err = errors.New("proto: repeated field " + f.name + " has nil element")
+			}
+			if err == errInvalidUTF8 {
+				if errLater == nil {
+					fullName := revProtoTypes[reflect.PtrTo(u.typ)] + "." + f.name
+					errLater = &invalidUTF8Error{fullName}
+				}
+				continue
+			}
+			return b, err
+		}
+	}
+	if u.unrecognized.IsValid() {
+		s := *ptr.offset(u.unrecognized).toBytes()
+		b = append(b, s...)
+	}
+	return b, errLater
+}
+
+// computeMarshalInfo initializes the marshal info.
+func (u *marshalInfo) computeMarshalInfo() {
+	u.Lock()
+	defer u.Unlock()
+	if u.initialized != 0 { // non-atomic read is ok as it is protected by the lock
+		return
+	}
+
+	t := u.typ
+	u.unrecognized = invalidField
+	u.extensions = invalidField
+	u.v1extensions = invalidField
+	u.sizecache = invalidField
+
+	// If the message can marshal itself, let it do it, for compatibility.
+	// NOTE: This is not efficient.
+	if reflect.PtrTo(t).Implements(marshalerType) {
+		u.hasmarshaler = true
+		atomic.StoreInt32(&u.initialized, 1)
+		return
+	}
+
+	// get oneof implementers
+	var oneofImplementers []interface{}
+	if m, ok := reflect.Zero(reflect.PtrTo(t)).Interface().(oneofMessage); ok {
+		_, _, _, oneofImplementers = m.XXX_OneofFuncs()
+	}
+
+	n := t.NumField()
+
+	// deal with XXX fields first
+	for i := 0; i < t.NumField(); i++ {
+		f := t.Field(i)
+		if !strings.HasPrefix(f.Name, "XXX_") {
+			continue
+		}
+		switch f.Name {
+		case "XXX_sizecache":
+			u.sizecache = toField(&f)
+		case "XXX_unrecognized":
+			u.unrecognized = toField(&f)
+		case "XXX_InternalExtensions":
+			u.extensions = toField(&f)
+			u.messageset = f.Tag.Get("protobuf_messageset") == "1"
+		case "XXX_extensions":
+			u.v1extensions = toField(&f)
+		case "XXX_NoUnkeyedLiteral":
+			// nothing to do
+		default:
+			panic("unknown XXX field: " + f.Name)
+		}
+		n--
+	}
+
+	// normal fields
+	fields := make([]marshalFieldInfo, n) // batch allocation
+	u.fields = make([]*marshalFieldInfo, 0, n)
+	for i, j := 0, 0; i < t.NumField(); i++ {
+		f := t.Field(i)
+
+		if strings.HasPrefix(f.Name, "XXX_") {
+			continue
+		}
+		field := &fields[j]
+		j++
+		field.name = f.Name
+		u.fields = append(u.fields, field)
+		if f.Tag.Get("protobuf_oneof") != "" {
+			field.computeOneofFieldInfo(&f, oneofImplementers)
+			continue
+		}
+		if f.Tag.Get("protobuf") == "" {
+			// field has no tag (not in generated message), ignore it
+			u.fields = u.fields[:len(u.fields)-1]
+			j--
+			continue
+		}
+		field.computeMarshalFieldInfo(&f)
+	}
+
+	// fields are marshaled in tag order on the wire.
+	sort.Sort(byTag(u.fields))
+
+	atomic.StoreInt32(&u.initialized, 1)
+}
+
+// helper for sorting fields by tag
+type byTag []*marshalFieldInfo
+
+func (a byTag) Len() int           { return len(a) }
+func (a byTag) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+func (a byTag) Less(i, j int) bool { return a[i].wiretag < a[j].wiretag }
+
+// getExtElemInfo returns the information to marshal an extension element.
+// The info it returns is initialized.
+func (u *marshalInfo) getExtElemInfo(desc *ExtensionDesc) *marshalElemInfo {
+	// get from cache first
+	u.RLock()
+	e, ok := u.extElems[desc.Field]
+	u.RUnlock()
+	if ok {
+		return e
+	}
+
+	t := reflect.TypeOf(desc.ExtensionType) // pointer or slice to basic type or struct
+	tags := strings.Split(desc.Tag, ",")
+	tag, err := strconv.Atoi(tags[1])
+	if err != nil {
+		panic("tag is not an integer")
+	}
+	wt := wiretype(tags[0])
+	sizer, marshaler := typeMarshaler(t, tags, false, false)
+	e = &marshalElemInfo{
+		wiretag:   uint64(tag)<<3 | wt,
+		tagsize:   SizeVarint(uint64(tag) << 3),
+		sizer:     sizer,
+		marshaler: marshaler,
+		isptr:     t.Kind() == reflect.Ptr,
+	}
+
+	// update cache
+	u.Lock()
+	if u.extElems == nil {
+		u.extElems = make(map[int32]*marshalElemInfo)
+	}
+	u.extElems[desc.Field] = e
+	u.Unlock()
+	return e
+}
+
+// computeMarshalFieldInfo fills up the information to marshal a field.
+func (fi *marshalFieldInfo) computeMarshalFieldInfo(f *reflect.StructField) {
+	// parse protobuf tag of the field.
+	// tag has format of "bytes,49,opt,name=foo,def=hello!"
+	tags := strings.Split(f.Tag.Get("protobuf"), ",")
+	if tags[0] == "" {
+		return
+	}
+	tag, err := strconv.Atoi(tags[1])
+	if err != nil {
+		panic("tag is not an integer")
+	}
+	wt := wiretype(tags[0])
+	if tags[2] == "req" {
+		fi.required = true
+	}
+	fi.setTag(f, tag, wt)
+	fi.setMarshaler(f, tags)
+}
+
+func (fi *marshalFieldInfo) computeOneofFieldInfo(f *reflect.StructField, oneofImplementers []interface{}) {
+	fi.field = toField(f)
+	fi.wiretag = 1<<31 - 1 // Use a large tag number, make oneofs sorted at the end. This tag will not appear on the wire.
+	fi.isPointer = true
+	fi.sizer, fi.marshaler = makeOneOfMarshaler(fi, f)
+	fi.oneofElems = make(map[reflect.Type]*marshalElemInfo)
+
+	ityp := f.Type // interface type
+	for _, o := range oneofImplementers {
+		t := reflect.TypeOf(o)
+		if !t.Implements(ityp) {
+			continue
+		}
+		sf := t.Elem().Field(0) // oneof implementer is a struct with a single field
+		tags := strings.Split(sf.Tag.Get("protobuf"), ",")
+		tag, err := strconv.Atoi(tags[1])
+		if err != nil {
+			panic("tag is not an integer")
+		}
+		wt := wiretype(tags[0])
+		sizer, marshaler := typeMarshaler(sf.Type, tags, false, true) // oneof should not omit any zero value
+		fi.oneofElems[t.Elem()] = &marshalElemInfo{
+			wiretag:   uint64(tag)<<3 | wt,
+			tagsize:   SizeVarint(uint64(tag) << 3),
+			sizer:     sizer,
+			marshaler: marshaler,
+		}
+	}
+}
+
+type oneofMessage interface {
+	XXX_OneofFuncs() (func(Message, *Buffer) error, func(Message, int, int, *Buffer) (bool, error), func(Message) int, []interface{})
+}
+
+// wiretype returns the wire encoding of the type.
+func wiretype(encoding string) uint64 {
+	switch encoding {
+	case "fixed32":
+		return WireFixed32
+	case "fixed64":
+		return WireFixed64
+	case "varint", "zigzag32", "zigzag64":
+		return WireVarint
+	case "bytes":
+		return WireBytes
+	case "group":
+		return WireStartGroup
+	}
+	panic("unknown wire type " + encoding)
+}
+
+// setTag fills up the tag (in wire format) and its size in the info of a field.
+func (fi *marshalFieldInfo) setTag(f *reflect.StructField, tag int, wt uint64) {
+	fi.field = toField(f)
+	fi.wiretag = uint64(tag)<<3 | wt
+	fi.tagsize = SizeVarint(uint64(tag) << 3)
+}
+
+// setMarshaler fills up the sizer and marshaler in the info of a field.
+func (fi *marshalFieldInfo) setMarshaler(f *reflect.StructField, tags []string) {
+	switch f.Type.Kind() {
+	case reflect.Map:
+		// map field
+		fi.isPointer = true
+		fi.sizer, fi.marshaler = makeMapMarshaler(f)
+		return
+	case reflect.Ptr, reflect.Slice:
+		fi.isPointer = true
+	}
+	fi.sizer, fi.marshaler = typeMarshaler(f.Type, tags, true, false)
+}
+
+// typeMarshaler returns the sizer and marshaler of a given field.
+// t is the type of the field.
+// tags is the generated "protobuf" tag of the field.
+// If nozero is true, zero value is not marshaled to the wire.
+// If oneof is true, it is a oneof field.
+func typeMarshaler(t reflect.Type, tags []string, nozero, oneof bool) (sizer, marshaler) {
+	encoding := tags[0]
+
+	pointer := false
+	slice := false
+	if t.Kind() == reflect.Slice && t.Elem().Kind() != reflect.Uint8 {
+		slice = true
+		t = t.Elem()
+	}
+	if t.Kind() == reflect.Ptr {
+		pointer = true
+		t = t.Elem()
+	}
+
+	packed := false
+	proto3 := false
+	validateUTF8 := true
+	for i := 2; i < len(tags); i++ {
+		if tags[i] == "packed" {
+			packed = true
+		}
+		if tags[i] == "proto3" {
+			proto3 = true
+		}
+	}
+	validateUTF8 = validateUTF8 && proto3
+
+	switch t.Kind() {
+	case reflect.Bool:
+		if pointer {
+			return sizeBoolPtr, appendBoolPtr
+		}
+		if slice {
+			if packed {
+				return sizeBoolPackedSlice, appendBoolPackedSlice
+			}
+			return sizeBoolSlice, appendBoolSlice
+		}
+		if nozero {
+			return sizeBoolValueNoZero, appendBoolValueNoZero
+		}
+		return sizeBoolValue, appendBoolValue
+	case reflect.Uint32:
+		switch encoding {
+		case "fixed32":
+			if pointer {
+				return sizeFixed32Ptr, appendFixed32Ptr
+			}
+			if slice {
+				if packed {
+					return sizeFixed32PackedSlice, appendFixed32PackedSlice
+				}
+				return sizeFixed32Slice, appendFixed32Slice
+			}
+			if nozero {
+				return sizeFixed32ValueNoZero, appendFixed32ValueNoZero
+			}
+			return sizeFixed32Value, appendFixed32Value
+		case "varint":
+			if pointer {
+				return sizeVarint32Ptr, appendVarint32Ptr
+			}
+			if slice {
+				if packed {
+					return sizeVarint32PackedSlice, appendVarint32PackedSlice
+				}
+				return sizeVarint32Slice, appendVarint32Slice
+			}
+			if nozero {
+				return sizeVarint32ValueNoZero, appendVarint32ValueNoZero
+			}
+			return sizeVarint32Value, appendVarint32Value
+		}
+	case reflect.Int32:
+		switch encoding {
+		case "fixed32":
+			if pointer {
+				return sizeFixedS32Ptr, appendFixedS32Ptr
+			}
+			if slice {
+				if packed {
+					return sizeFixedS32PackedSlice, appendFixedS32PackedSlice
+				}
+				return sizeFixedS32Slice, appendFixedS32Slice
+			}
+			if nozero {
+				return sizeFixedS32ValueNoZero, appendFixedS32ValueNoZero
+			}
+			return sizeFixedS32Value, appendFixedS32Value
+		case "varint":
+			if pointer {
+				return sizeVarintS32Ptr, appendVarintS32Ptr
+			}
+			if slice {
+				if packed {
+					return sizeVarintS32PackedSlice, appendVarintS32PackedSlice
+				}
+				return sizeVarintS32Slice, appendVarintS32Slice
+			}
+			if nozero {
+				return sizeVarintS32ValueNoZero, appendVarintS32ValueNoZero
+			}
+			return sizeVarintS32Value, appendVarintS32Value
+		case "zigzag32":
+			if pointer {
+				return sizeZigzag32Ptr, appendZigzag32Ptr
+			}
+			if slice {
+				if packed {
+					return sizeZigzag32PackedSlice, appendZigzag32PackedSlice
+				}
+				return sizeZigzag32Slice, appendZigzag32Slice
+			}
+			if nozero {
+				return sizeZigzag32ValueNoZero, appendZigzag32ValueNoZero
+			}
+			return sizeZigzag32Value, appendZigzag32Value
+		}
+	case reflect.Uint64:
+		switch encoding {
+		case "fixed64":
+			if pointer {
+				return sizeFixed64Ptr, appendFixed64Ptr
+			}
+			if slice {
+				if packed {
+					return sizeFixed64PackedSlice, appendFixed64PackedSlice
+				}
+				return sizeFixed64Slice, appendFixed64Slice
+			}
+			if nozero {
+				return sizeFixed64ValueNoZero, appendFixed64ValueNoZero
+			}
+			return sizeFixed64Value, appendFixed64Value
+		case "varint":
+			if pointer {
+				return sizeVarint64Ptr, appendVarint64Ptr
+			}
+			if slice {
+				if packed {
+					return sizeVarint64PackedSlice, appendVarint64PackedSlice
+				}
+				return sizeVarint64Slice, appendVarint64Slice
+			}
+			if nozero {
+				return sizeVarint64ValueNoZero, appendVarint64ValueNoZero
+			}
+			return sizeVarint64Value, appendVarint64Value
+		}
+	case reflect.Int64:
+		switch encoding {
+		case "fixed64":
+			if pointer {
+				return sizeFixedS64Ptr, appendFixedS64Ptr
+			}
+			if slice {
+				if packed {
+					return sizeFixedS64PackedSlice, appendFixedS64PackedSlice
+				}
+				return sizeFixedS64Slice, appendFixedS64Slice
+			}
+			if nozero {
+				return sizeFixedS64ValueNoZero, appendFixedS64ValueNoZero
+			}
+			return sizeFixedS64Value, appendFixedS64Value
+		case "varint":
+			if pointer {
+				return sizeVarintS64Ptr, appendVarintS64Ptr
+			}
+			if slice {
+				if packed {
+					return sizeVarintS64PackedSlice, appendVarintS64PackedSlice
+				}
+				return sizeVarintS64Slice, appendVarintS64Slice
+			}
+			if nozero {
+				return sizeVarintS64ValueNoZero, appendVarintS64ValueNoZero
+			}
+			return sizeVarintS64Value, appendVarintS64Value
+		case "zigzag64":
+			if pointer {
+				return sizeZigzag64Ptr, appendZigzag64Ptr
+			}
+			if slice {
+				if packed {
+					return sizeZigzag64PackedSlice, appendZigzag64PackedSlice
+				}
+				return sizeZigzag64Slice, appendZigzag64Slice
+			}
+			if nozero {
+				return sizeZigzag64ValueNoZero, appendZigzag64ValueNoZero
+			}
+			return sizeZigzag64Value, appendZigzag64Value
+		}
+	case reflect.Float32:
+		if pointer {
+			return sizeFloat32Ptr, appendFloat32Ptr
+		}
+		if slice {
+			if packed {
+				return sizeFloat32PackedSlice, appendFloat32PackedSlice
+			}
+			return sizeFloat32Slice, appendFloat32Slice
+		}
+		if nozero {
+			return sizeFloat32ValueNoZero, appendFloat32ValueNoZero
+		}
+		return sizeFloat32Value, appendFloat32Value
+	case reflect.Float64:
+		if pointer {
+			return sizeFloat64Ptr, appendFloat64Ptr
+		}
+		if slice {
+			if packed {
+				return sizeFloat64PackedSlice, appendFloat64PackedSlice
+			}
+			return sizeFloat64Slice, appendFloat64Slice
+		}
+		if nozero {
+			return sizeFloat64ValueNoZero, appendFloat64ValueNoZero
+		}
+		return sizeFloat64Value, appendFloat64Value
+	case reflect.String:
+		if validateUTF8 {
+			if pointer {
+				return sizeStringPtr, appendUTF8StringPtr
+			}
+			if slice {
+				return sizeStringSlice, appendUTF8StringSlice
+			}
+			if nozero {
+				return sizeStringValueNoZero, appendUTF8StringValueNoZero
+			}
+			return sizeStringValue, appendUTF8StringValue
+		}
+		if pointer {
+			return sizeStringPtr, appendStringPtr
+		}
+		if slice {
+			return sizeStringSlice, appendStringSlice
+		}
+		if nozero {
+			return sizeStringValueNoZero, appendStringValueNoZero
+		}
+		return sizeStringValue, appendStringValue
+	case reflect.Slice:
+		if slice {
+			return sizeBytesSlice, appendBytesSlice
+		}
+		if oneof {
+			// Oneof bytes field may also have "proto3" tag.
+			// We want to marshal it as a oneof field. Do this
+			// check before the proto3 check.
+			return sizeBytesOneof, appendBytesOneof
+		}
+		if proto3 {
+			return sizeBytes3, appendBytes3
+		}
+		return sizeBytes, appendBytes
+	case reflect.Struct:
+		switch encoding {
+		case "group":
+			if slice {
+				return makeGroupSliceMarshaler(getMarshalInfo(t))
+			}
+			return makeGroupMarshaler(getMarshalInfo(t))
+		case "bytes":
+			if slice {
+				return makeMessageSliceMarshaler(getMarshalInfo(t))
+			}
+			return makeMessageMarshaler(getMarshalInfo(t))
+		}
+	}
+	panic(fmt.Sprintf("unknown or mismatched type: type: %v, wire type: %v", t, encoding))
+}
+
+// Below are functions to size/marshal a specific type of a field.
+// They are stored in the field's info, and called by function pointers.
+// They have type sizer or marshaler.
+
+func sizeFixed32Value(_ pointer, tagsize int) int {
+	return 4 + tagsize
+}
+func sizeFixed32ValueNoZero(ptr pointer, tagsize int) int {
+	v := *ptr.toUint32()
+	if v == 0 {
+		return 0
+	}
+	return 4 + tagsize
+}
+func sizeFixed32Ptr(ptr pointer, tagsize int) int {
+	p := *ptr.toUint32Ptr()
+	if p == nil {
+		return 0
+	}
+	return 4 + tagsize
+}
+func sizeFixed32Slice(ptr pointer, tagsize int) int {
+	s := *ptr.toUint32Slice()
+	return (4 + tagsize) * len(s)
+}
+func sizeFixed32PackedSlice(ptr pointer, tagsize int) int {
+	s := *ptr.toUint32Slice()
+	if len(s) == 0 {
+		return 0
+	}
+	return 4*len(s) + SizeVarint(uint64(4*len(s))) + tagsize
+}
+func sizeFixedS32Value(_ pointer, tagsize int) int {
+	return 4 + tagsize
+}
+func sizeFixedS32ValueNoZero(ptr pointer, tagsize int) int {
+	v := *ptr.toInt32()
+	if v == 0 {
+		return 0
+	}
+	return 4 + tagsize
+}
+func sizeFixedS32Ptr(ptr pointer, tagsize int) int {
+	p := ptr.getInt32Ptr()
+	if p == nil {
+		return 0
+	}
+	return 4 + tagsize
+}
+func sizeFixedS32Slice(ptr pointer, tagsize int) int {
+	s := ptr.getInt32Slice()
+	return (4 + tagsize) * len(s)
+}
+func sizeFixedS32PackedSlice(ptr pointer, tagsize int) int {
+	s := ptr.getInt32Slice()
+	if len(s) == 0 {
+		return 0
+	}
+	return 4*len(s) + SizeVarint(uint64(4*len(s))) + tagsize
+}
+func sizeFloat32Value(_ pointer, tagsize int) int {
+	return 4 + tagsize
+}
+func sizeFloat32ValueNoZero(ptr pointer, tagsize int) int {
+	v := math.Float32bits(*ptr.toFloat32())
+	if v == 0 {
+		return 0
+	}
+	return 4 + tagsize
+}
+func sizeFloat32Ptr(ptr pointer, tagsize int) int {
+	p := *ptr.toFloat32Ptr()
+	if p == nil {
+		return 0
+	}
+	return 4 + tagsize
+}
+func sizeFloat32Slice(ptr pointer, tagsize int) int {
+	s := *ptr.toFloat32Slice()
+	return (4 + tagsize) * len(s)
+}
+func sizeFloat32PackedSlice(ptr pointer, tagsize int) int {
+	s := *ptr.toFloat32Slice()
+	if len(s) == 0 {
+		return 0
+	}
+	return 4*len(s) + SizeVarint(uint64(4*len(s))) + tagsize
+}
+func sizeFixed64Value(_ pointer, tagsize int) int {
+	return 8 + tagsize
+}
+func sizeFixed64ValueNoZero(ptr pointer, tagsize int) int {
+	v := *ptr.toUint64()
+	if v == 0 {
+		return 0
+	}
+	return 8 + tagsize
+}
+func sizeFixed64Ptr(ptr pointer, tagsize int) int {
+	p := *ptr.toUint64Ptr()
+	if p == nil {
+		return 0
+	}
+	return 8 + tagsize
+}
+func sizeFixed64Slice(ptr pointer, tagsize int) int {
+	s := *ptr.toUint64Slice()
+	return (8 + tagsize) * len(s)
+}
+func sizeFixed64PackedSlice(ptr pointer, tagsize int) int {
+	s := *ptr.toUint64Slice()
+	if len(s) == 0 {
+		return 0
+	}
+	return 8*len(s) + SizeVarint(uint64(8*len(s))) + tagsize
+}
+func sizeFixedS64Value(_ pointer, tagsize int) int {
+	return 8 + tagsize
+}
+func sizeFixedS64ValueNoZero(ptr pointer, tagsize int) int {
+	v := *ptr.toInt64()
+	if v == 0 {
+		return 0
+	}
+	return 8 + tagsize
+}
+func sizeFixedS64Ptr(ptr pointer, tagsize int) int {
+	p := *ptr.toInt64Ptr()
+	if p == nil {
+		return 0
+	}
+	return 8 + tagsize
+}
+func sizeFixedS64Slice(ptr pointer, tagsize int) int {
+	s := *ptr.toInt64Slice()
+	return (8 + tagsize) * len(s)
+}
+func sizeFixedS64PackedSlice(ptr pointer, tagsize int) int {
+	s := *ptr.toInt64Slice()
+	if len(s) == 0 {
+		return 0
+	}
+	return 8*len(s) + SizeVarint(uint64(8*len(s))) + tagsize
+}
+func sizeFloat64Value(_ pointer, tagsize int) int {
+	return 8 + tagsize
+}
+func sizeFloat64ValueNoZero(ptr pointer, tagsize int) int {
+	v := math.Float64bits(*ptr.toFloat64())
+	if v == 0 {
+		return 0
+	}
+	return 8 + tagsize
+}
+func sizeFloat64Ptr(ptr pointer, tagsize int) int {
+	p := *ptr.toFloat64Ptr()
+	if p == nil {
+		return 0
+	}
+	return 8 + tagsize
+}
+func sizeFloat64Slice(ptr pointer, tagsize int) int {
+	s := *ptr.toFloat64Slice()
+	return (8 + tagsize) * len(s)
+}
+func sizeFloat64PackedSlice(ptr pointer, tagsize int) int {
+	s := *ptr.toFloat64Slice()
+	if len(s) == 0 {
+		return 0
+	}
+	return 8*len(s) + SizeVarint(uint64(8*len(s))) + tagsize
+}
+func sizeVarint32Value(ptr pointer, tagsize int) int {
+	v := *ptr.toUint32()
+	return SizeVarint(uint64(v)) + tagsize
+}
+func sizeVarint32ValueNoZero(ptr pointer, tagsize int) int {
+	v := *ptr.toUint32()
+	if v == 0 {
+		return 0
+	}
+	return SizeVarint(uint64(v)) + tagsize
+}
+func sizeVarint32Ptr(ptr pointer, tagsize int) int {
+	p := *ptr.toUint32Ptr()
+	if p == nil {
+		return 0
+	}
+	return SizeVarint(uint64(*p)) + tagsize
+}
+func sizeVarint32Slice(ptr pointer, tagsize int) int {
+	s := *ptr.toUint32Slice()
+	n := 0
+	for _, v := range s {
+		n += SizeVarint(uint64(v)) + tagsize
+	}
+	return n
+}
+func sizeVarint32PackedSlice(ptr pointer, tagsize int) int {
+	s := *ptr.toUint32Slice()
+	if len(s) == 0 {
+		return 0
+	}
+	n := 0
+	for _, v := range s {
+		n += SizeVarint(uint64(v))
+	}
+	return n + SizeVarint(uint64(n)) + tagsize
+}
+func sizeVarintS32Value(ptr pointer, tagsize int) int {
+	v := *ptr.toInt32()
+	return SizeVarint(uint64(v)) + tagsize
+}
+func sizeVarintS32ValueNoZero(ptr pointer, tagsize int) int {
+	v := *ptr.toInt32()
+	if v == 0 {
+		return 0
+	}
+	return SizeVarint(uint64(v)) + tagsize
+}
+func sizeVarintS32Ptr(ptr pointer, tagsize int) int {
+	p := ptr.getInt32Ptr()
+	if p == nil {
+		return 0
+	}
+	return SizeVarint(uint64(*p)) + tagsize
+}
+func sizeVarintS32Slice(ptr pointer, tagsize int) int {
+	s := ptr.getInt32Slice()
+	n := 0
+	for _, v := range s {
+		n += SizeVarint(uint64(v)) + tagsize
+	}
+	return n
+}
+func sizeVarintS32PackedSlice(ptr pointer, tagsize int) int {
+	s := ptr.getInt32Slice()
+	if len(s) == 0 {
+		return 0
+	}
+	n := 0
+	for _, v := range s {
+		n += SizeVarint(uint64(v))
+	}
+	return n + SizeVarint(uint64(n)) + tagsize
+}
+func sizeVarint64Value(ptr pointer, tagsize int) int {
+	v := *ptr.toUint64()
+	return SizeVarint(v) + tagsize
+}
+func sizeVarint64ValueNoZero(ptr pointer, tagsize int) int {
+	v := *ptr.toUint64()
+	if v == 0 {
+		return 0
+	}
+	return SizeVarint(v) + tagsize
+}
+func sizeVarint64Ptr(ptr pointer, tagsize int) int {
+	p := *ptr.toUint64Ptr()
+	if p == nil {
+		return 0
+	}
+	return SizeVarint(*p) + tagsize
+}
+func sizeVarint64Slice(ptr pointer, tagsize int) int {
+	s := *ptr.toUint64Slice()
+	n := 0
+	for _, v := range s {
+		n += SizeVarint(v) + tagsize
+	}
+	return n
+}
+func sizeVarint64PackedSlice(ptr pointer, tagsize int) int {
+	s := *ptr.toUint64Slice()
+	if len(s) == 0 {
+		return 0
+	}
+	n := 0
+	for _, v := range s {
+		n += SizeVarint(v)
+	}
+	return n + SizeVarint(uint64(n)) + tagsize
+}
+func sizeVarintS64Value(ptr pointer, tagsize int) int {
+	v := *ptr.toInt64()
+	return SizeVarint(uint64(v)) + tagsize
+}
+func sizeVarintS64ValueNoZero(ptr pointer, tagsize int) int {
+	v := *ptr.toInt64()
+	if v == 0 {
+		return 0
+	}
+	return SizeVarint(uint64(v)) + tagsize
+}
+func sizeVarintS64Ptr(ptr pointer, tagsize int) int {
+	p := *ptr.toInt64Ptr()
+	if p == nil {
+		return 0
+	}
+	return SizeVarint(uint64(*p)) + tagsize
+}
+func sizeVarintS64Slice(ptr pointer, tagsize int) int {
+	s := *ptr.toInt64Slice()
+	n := 0
+	for _, v := range s {
+		n += SizeVarint(uint64(v)) + tagsize
+	}
+	return n
+}
+func sizeVarintS64PackedSlice(ptr pointer, tagsize int) int {
+	s := *ptr.toInt64Slice()
+	if len(s) == 0 {
+		return 0
+	}
+	n := 0
+	for _, v := range s {
+		n += SizeVarint(uint64(v))
+	}
+	return n + SizeVarint(uint64(n)) + tagsize
+}
+func sizeZigzag32Value(ptr pointer, tagsize int) int {
+	v := *ptr.toInt32()
+	return SizeVarint(uint64((uint32(v)<<1)^uint32((int32(v)>>31)))) + tagsize
+}
+func sizeZigzag32ValueNoZero(ptr pointer, tagsize int) int {
+	v := *ptr.toInt32()
+	if v == 0 {
+		return 0
+	}
+	return SizeVarint(uint64((uint32(v)<<1)^uint32((int32(v)>>31)))) + tagsize
+}
+func sizeZigzag32Ptr(ptr pointer, tagsize int) int {
+	p := ptr.getInt32Ptr()
+	if p == nil {
+		return 0
+	}
+	v := *p
+	return SizeVarint(uint64((uint32(v)<<1)^uint32((int32(v)>>31)))) + tagsize
+}
+func sizeZigzag32Slice(ptr pointer, tagsize int) int {
+	s := ptr.getInt32Slice()
+	n := 0
+	for _, v := range s {
+		n += SizeVarint(uint64((uint32(v)<<1)^uint32((int32(v)>>31)))) + tagsize
+	}
+	return n
+}
+func sizeZigzag32PackedSlice(ptr pointer, tagsize int) int {
+	s := ptr.getInt32Slice()
+	if len(s) == 0 {
+		return 0
+	}
+	n := 0
+	for _, v := range s {
+		n += SizeVarint(uint64((uint32(v) << 1) ^ uint32((int32(v) >> 31))))
+	}
+	return n + SizeVarint(uint64(n)) + tagsize
+}
+func sizeZigzag64Value(ptr pointer, tagsize int) int {
+	v := *ptr.toInt64()
+	return SizeVarint(uint64(v<<1)^uint64((int64(v)>>63))) + tagsize
+}
+func sizeZigzag64ValueNoZero(ptr pointer, tagsize int) int {
+	v := *ptr.toInt64()
+	if v == 0 {
+		return 0
+	}
+	return SizeVarint(uint64(v<<1)^uint64((int64(v)>>63))) + tagsize
+}
+func sizeZigzag64Ptr(ptr pointer, tagsize int) int {
+	p := *ptr.toInt64Ptr()
+	if p == nil {
+		return 0
+	}
+	v := *p
+	return SizeVarint(uint64(v<<1)^uint64((int64(v)>>63))) + tagsize
+}
+func sizeZigzag64Slice(ptr pointer, tagsize int) int {
+	s := *ptr.toInt64Slice()
+	n := 0
+	for _, v := range s {
+		n += SizeVarint(uint64(v<<1)^uint64((int64(v)>>63))) + tagsize
+	}
+	return n
+}
+func sizeZigzag64PackedSlice(ptr pointer, tagsize int) int {
+	s := *ptr.toInt64Slice()
+	if len(s) == 0 {
+		return 0
+	}
+	n := 0
+	for _, v := range s {
+		n += SizeVarint(uint64(v<<1) ^ uint64((int64(v) >> 63)))
+	}
+	return n + SizeVarint(uint64(n)) + tagsize
+}
+func sizeBoolValue(_ pointer, tagsize int) int {
+	return 1 + tagsize
+}
+func sizeBoolValueNoZero(ptr pointer, tagsize int) int {
+	v := *ptr.toBool()
+	if !v {
+		return 0
+	}
+	return 1 + tagsize
+}
+func sizeBoolPtr(ptr pointer, tagsize int) int {
+	p := *ptr.toBoolPtr()
+	if p == nil {
+		return 0
+	}
+	return 1 + tagsize
+}
+func sizeBoolSlice(ptr pointer, tagsize int) int {
+	s := *ptr.toBoolSlice()
+	return (1 + tagsize) * len(s)
+}
+func sizeBoolPackedSlice(ptr pointer, tagsize int) int {
+	s := *ptr.toBoolSlice()
+	if len(s) == 0 {
+		return 0
+	}
+	return len(s) + SizeVarint(uint64(len(s))) + tagsize
+}
+func sizeStringValue(ptr pointer, tagsize int) int {
+	v := *ptr.toString()
+	return len(v) + SizeVarint(uint64(len(v))) + tagsize
+}
+func sizeStringValueNoZero(ptr pointer, tagsize int) int {
+	v := *ptr.toString()
+	if v == "" {
+		return 0
+	}
+	return len(v) + SizeVarint(uint64(len(v))) + tagsize
+}
+func sizeStringPtr(ptr pointer, tagsize int) int {
+	p := *ptr.toStringPtr()
+	if p == nil {
+		return 0
+	}
+	v := *p
+	return len(v) + SizeVarint(uint64(len(v))) + tagsize
+}
+func sizeStringSlice(ptr pointer, tagsize int) int {
+	s := *ptr.toStringSlice()
+	n := 0
+	for _, v := range s {
+		n += len(v) + SizeVarint(uint64(len(v))) + tagsize
+	}
+	return n
+}
+func sizeBytes(ptr pointer, tagsize int) int {
+	v := *ptr.toBytes()
+	if v == nil {
+		return 0
+	}
+	return len(v) + SizeVarint(uint64(len(v))) + tagsize
+}
+func sizeBytes3(ptr pointer, tagsize int) int {
+	v := *ptr.toBytes()
+	if len(v) == 0 {
+		return 0
+	}
+	return len(v) + SizeVarint(uint64(len(v))) + tagsize
+}
+func sizeBytesOneof(ptr pointer, tagsize int) int {
+	v := *ptr.toBytes()
+	return len(v) + SizeVarint(uint64(len(v))) + tagsize
+}
+func sizeBytesSlice(ptr pointer, tagsize int) int {
+	s := *ptr.toBytesSlice()
+	n := 0
+	for _, v := range s {
+		n += len(v) + SizeVarint(uint64(len(v))) + tagsize
+	}
+	return n
+}
+
+// appendFixed32 appends an encoded fixed32 to b.
+func appendFixed32(b []byte, v uint32) []byte {
+	b = append(b,
+		byte(v),
+		byte(v>>8),
+		byte(v>>16),
+		byte(v>>24))
+	return b
+}
+
+// appendFixed64 appends an encoded fixed64 to b.
+func appendFixed64(b []byte, v uint64) []byte {
+	b = append(b,
+		byte(v),
+		byte(v>>8),
+		byte(v>>16),
+		byte(v>>24),
+		byte(v>>32),
+		byte(v>>40),
+		byte(v>>48),
+		byte(v>>56))
+	return b
+}
+
+// appendVarint appends an encoded varint to b.
+func appendVarint(b []byte, v uint64) []byte {
+	// TODO: make 1-byte (maybe 2-byte) case inline-able, once we
+	// have non-leaf inliner.
+	switch {
+	case v < 1<<7:
+		b = append(b, byte(v))
+	case v < 1<<14:
+		b = append(b,
+			byte(v&0x7f|0x80),
+			byte(v>>7))
+	case v < 1<<21:
+		b = append(b,
+			byte(v&0x7f|0x80),
+			byte((v>>7)&0x7f|0x80),
+			byte(v>>14))
+	case v < 1<<28:
+		b = append(b,
+			byte(v&0x7f|0x80),
+			byte((v>>7)&0x7f|0x80),
+			byte((v>>14)&0x7f|0x80),
+			byte(v>>21))
+	case v < 1<<35:
+		b = append(b,
+			byte(v&0x7f|0x80),
+			byte((v>>7)&0x7f|0x80),
+			byte((v>>14)&0x7f|0x80),
+			byte((v>>21)&0x7f|0x80),
+			byte(v>>28))
+	case v < 1<<42:
+		b = append(b,
+			byte(v&0x7f|0x80),
+			byte((v>>7)&0x7f|0x80),
+			byte((v>>14)&0x7f|0x80),
+			byte((v>>21)&0x7f|0x80),
+			byte((v>>28)&0x7f|0x80),
+			byte(v>>35))
+	case v < 1<<49:
+		b = append(b,
+			byte(v&0x7f|0x80),
+			byte((v>>7)&0x7f|0x80),
+			byte((v>>14)&0x7f|0x80),
+			byte((v>>21)&0x7f|0x80),
+			byte((v>>28)&0x7f|0x80),
+			byte((v>>35)&0x7f|0x80),
+			byte(v>>42))
+	case v < 1<<56:
+		b = append(b,
+			byte(v&0x7f|0x80),
+			byte((v>>7)&0x7f|0x80),
+			byte((v>>14)&0x7f|0x80),
+			byte((v>>21)&0x7f|0x80),
+			byte((v>>28)&0x7f|0x80),
+			byte((v>>35)&0x7f|0x80),
+			byte((v>>42)&0x7f|0x80),
+			byte(v>>49))
+	case v < 1<<63:
+		b = append(b,
+			byte(v&0x7f|0x80),
+			byte((v>>7)&0x7f|0x80),
+			byte((v>>14)&0x7f|0x80),
+			byte((v>>21)&0x7f|0x80),
+			byte((v>>28)&0x7f|0x80),
+			byte((v>>35)&0x7f|0x80),
+			byte((v>>42)&0x7f|0x80),
+			byte((v>>49)&0x7f|0x80),
+			byte(v>>56))
+	default:
+		b = append(b,
+			byte(v&0x7f|0x80),
+			byte((v>>7)&0x7f|0x80),
+			byte((v>>14)&0x7f|0x80),
+			byte((v>>21)&0x7f|0x80),
+			byte((v>>28)&0x7f|0x80),
+			byte((v>>35)&0x7f|0x80),
+			byte((v>>42)&0x7f|0x80),
+			byte((v>>49)&0x7f|0x80),
+			byte((v>>56)&0x7f|0x80),
+			1)
+	}
+	return b
+}
+
+func appendFixed32Value(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toUint32()
+	b = appendVarint(b, wiretag)
+	b = appendFixed32(b, v)
+	return b, nil
+}
+func appendFixed32ValueNoZero(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toUint32()
+	if v == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendFixed32(b, v)
+	return b, nil
+}
+func appendFixed32Ptr(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	p := *ptr.toUint32Ptr()
+	if p == nil {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendFixed32(b, *p)
+	return b, nil
+}
+func appendFixed32Slice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := *ptr.toUint32Slice()
+	for _, v := range s {
+		b = appendVarint(b, wiretag)
+		b = appendFixed32(b, v)
+	}
+	return b, nil
+}
+func appendFixed32PackedSlice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := *ptr.toUint32Slice()
+	if len(s) == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag&^7|WireBytes)
+	b = appendVarint(b, uint64(4*len(s)))
+	for _, v := range s {
+		b = appendFixed32(b, v)
+	}
+	return b, nil
+}
+func appendFixedS32Value(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toInt32()
+	b = appendVarint(b, wiretag)
+	b = appendFixed32(b, uint32(v))
+	return b, nil
+}
+func appendFixedS32ValueNoZero(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toInt32()
+	if v == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendFixed32(b, uint32(v))
+	return b, nil
+}
+func appendFixedS32Ptr(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	p := ptr.getInt32Ptr()
+	if p == nil {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendFixed32(b, uint32(*p))
+	return b, nil
+}
+func appendFixedS32Slice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := ptr.getInt32Slice()
+	for _, v := range s {
+		b = appendVarint(b, wiretag)
+		b = appendFixed32(b, uint32(v))
+	}
+	return b, nil
+}
+func appendFixedS32PackedSlice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := ptr.getInt32Slice()
+	if len(s) == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag&^7|WireBytes)
+	b = appendVarint(b, uint64(4*len(s)))
+	for _, v := range s {
+		b = appendFixed32(b, uint32(v))
+	}
+	return b, nil
+}
+func appendFloat32Value(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := math.Float32bits(*ptr.toFloat32())
+	b = appendVarint(b, wiretag)
+	b = appendFixed32(b, v)
+	return b, nil
+}
+func appendFloat32ValueNoZero(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := math.Float32bits(*ptr.toFloat32())
+	if v == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendFixed32(b, v)
+	return b, nil
+}
+func appendFloat32Ptr(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	p := *ptr.toFloat32Ptr()
+	if p == nil {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendFixed32(b, math.Float32bits(*p))
+	return b, nil
+}
+func appendFloat32Slice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := *ptr.toFloat32Slice()
+	for _, v := range s {
+		b = appendVarint(b, wiretag)
+		b = appendFixed32(b, math.Float32bits(v))
+	}
+	return b, nil
+}
+func appendFloat32PackedSlice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := *ptr.toFloat32Slice()
+	if len(s) == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag&^7|WireBytes)
+	b = appendVarint(b, uint64(4*len(s)))
+	for _, v := range s {
+		b = appendFixed32(b, math.Float32bits(v))
+	}
+	return b, nil
+}
+func appendFixed64Value(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toUint64()
+	b = appendVarint(b, wiretag)
+	b = appendFixed64(b, v)
+	return b, nil
+}
+func appendFixed64ValueNoZero(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toUint64()
+	if v == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendFixed64(b, v)
+	return b, nil
+}
+func appendFixed64Ptr(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	p := *ptr.toUint64Ptr()
+	if p == nil {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendFixed64(b, *p)
+	return b, nil
+}
+func appendFixed64Slice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := *ptr.toUint64Slice()
+	for _, v := range s {
+		b = appendVarint(b, wiretag)
+		b = appendFixed64(b, v)
+	}
+	return b, nil
+}
+func appendFixed64PackedSlice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := *ptr.toUint64Slice()
+	if len(s) == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag&^7|WireBytes)
+	b = appendVarint(b, uint64(8*len(s)))
+	for _, v := range s {
+		b = appendFixed64(b, v)
+	}
+	return b, nil
+}
+func appendFixedS64Value(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toInt64()
+	b = appendVarint(b, wiretag)
+	b = appendFixed64(b, uint64(v))
+	return b, nil
+}
+func appendFixedS64ValueNoZero(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toInt64()
+	if v == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendFixed64(b, uint64(v))
+	return b, nil
+}
+func appendFixedS64Ptr(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	p := *ptr.toInt64Ptr()
+	if p == nil {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendFixed64(b, uint64(*p))
+	return b, nil
+}
+func appendFixedS64Slice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := *ptr.toInt64Slice()
+	for _, v := range s {
+		b = appendVarint(b, wiretag)
+		b = appendFixed64(b, uint64(v))
+	}
+	return b, nil
+}
+func appendFixedS64PackedSlice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := *ptr.toInt64Slice()
+	if len(s) == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag&^7|WireBytes)
+	b = appendVarint(b, uint64(8*len(s)))
+	for _, v := range s {
+		b = appendFixed64(b, uint64(v))
+	}
+	return b, nil
+}
+func appendFloat64Value(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := math.Float64bits(*ptr.toFloat64())
+	b = appendVarint(b, wiretag)
+	b = appendFixed64(b, v)
+	return b, nil
+}
+func appendFloat64ValueNoZero(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := math.Float64bits(*ptr.toFloat64())
+	if v == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendFixed64(b, v)
+	return b, nil
+}
+func appendFloat64Ptr(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	p := *ptr.toFloat64Ptr()
+	if p == nil {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendFixed64(b, math.Float64bits(*p))
+	return b, nil
+}
+func appendFloat64Slice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := *ptr.toFloat64Slice()
+	for _, v := range s {
+		b = appendVarint(b, wiretag)
+		b = appendFixed64(b, math.Float64bits(v))
+	}
+	return b, nil
+}
+func appendFloat64PackedSlice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := *ptr.toFloat64Slice()
+	if len(s) == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag&^7|WireBytes)
+	b = appendVarint(b, uint64(8*len(s)))
+	for _, v := range s {
+		b = appendFixed64(b, math.Float64bits(v))
+	}
+	return b, nil
+}
+func appendVarint32Value(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toUint32()
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, uint64(v))
+	return b, nil
+}
+func appendVarint32ValueNoZero(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toUint32()
+	if v == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, uint64(v))
+	return b, nil
+}
+func appendVarint32Ptr(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	p := *ptr.toUint32Ptr()
+	if p == nil {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, uint64(*p))
+	return b, nil
+}
+func appendVarint32Slice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := *ptr.toUint32Slice()
+	for _, v := range s {
+		b = appendVarint(b, wiretag)
+		b = appendVarint(b, uint64(v))
+	}
+	return b, nil
+}
+func appendVarint32PackedSlice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := *ptr.toUint32Slice()
+	if len(s) == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag&^7|WireBytes)
+	// compute size
+	n := 0
+	for _, v := range s {
+		n += SizeVarint(uint64(v))
+	}
+	b = appendVarint(b, uint64(n))
+	for _, v := range s {
+		b = appendVarint(b, uint64(v))
+	}
+	return b, nil
+}
+func appendVarintS32Value(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toInt32()
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, uint64(v))
+	return b, nil
+}
+func appendVarintS32ValueNoZero(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toInt32()
+	if v == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, uint64(v))
+	return b, nil
+}
+func appendVarintS32Ptr(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	p := ptr.getInt32Ptr()
+	if p == nil {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, uint64(*p))
+	return b, nil
+}
+func appendVarintS32Slice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := ptr.getInt32Slice()
+	for _, v := range s {
+		b = appendVarint(b, wiretag)
+		b = appendVarint(b, uint64(v))
+	}
+	return b, nil
+}
+func appendVarintS32PackedSlice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := ptr.getInt32Slice()
+	if len(s) == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag&^7|WireBytes)
+	// compute size
+	n := 0
+	for _, v := range s {
+		n += SizeVarint(uint64(v))
+	}
+	b = appendVarint(b, uint64(n))
+	for _, v := range s {
+		b = appendVarint(b, uint64(v))
+	}
+	return b, nil
+}
+func appendVarint64Value(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toUint64()
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, v)
+	return b, nil
+}
+func appendVarint64ValueNoZero(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toUint64()
+	if v == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, v)
+	return b, nil
+}
+func appendVarint64Ptr(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	p := *ptr.toUint64Ptr()
+	if p == nil {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, *p)
+	return b, nil
+}
+func appendVarint64Slice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := *ptr.toUint64Slice()
+	for _, v := range s {
+		b = appendVarint(b, wiretag)
+		b = appendVarint(b, v)
+	}
+	return b, nil
+}
+func appendVarint64PackedSlice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := *ptr.toUint64Slice()
+	if len(s) == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag&^7|WireBytes)
+	// compute size
+	n := 0
+	for _, v := range s {
+		n += SizeVarint(v)
+	}
+	b = appendVarint(b, uint64(n))
+	for _, v := range s {
+		b = appendVarint(b, v)
+	}
+	return b, nil
+}
+func appendVarintS64Value(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toInt64()
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, uint64(v))
+	return b, nil
+}
+func appendVarintS64ValueNoZero(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toInt64()
+	if v == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, uint64(v))
+	return b, nil
+}
+func appendVarintS64Ptr(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	p := *ptr.toInt64Ptr()
+	if p == nil {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, uint64(*p))
+	return b, nil
+}
+func appendVarintS64Slice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := *ptr.toInt64Slice()
+	for _, v := range s {
+		b = appendVarint(b, wiretag)
+		b = appendVarint(b, uint64(v))
+	}
+	return b, nil
+}
+func appendVarintS64PackedSlice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := *ptr.toInt64Slice()
+	if len(s) == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag&^7|WireBytes)
+	// compute size
+	n := 0
+	for _, v := range s {
+		n += SizeVarint(uint64(v))
+	}
+	b = appendVarint(b, uint64(n))
+	for _, v := range s {
+		b = appendVarint(b, uint64(v))
+	}
+	return b, nil
+}
+func appendZigzag32Value(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toInt32()
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, uint64((uint32(v)<<1)^uint32((int32(v)>>31))))
+	return b, nil
+}
+func appendZigzag32ValueNoZero(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toInt32()
+	if v == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, uint64((uint32(v)<<1)^uint32((int32(v)>>31))))
+	return b, nil
+}
+func appendZigzag32Ptr(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	p := ptr.getInt32Ptr()
+	if p == nil {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	v := *p
+	b = appendVarint(b, uint64((uint32(v)<<1)^uint32((int32(v)>>31))))
+	return b, nil
+}
+func appendZigzag32Slice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := ptr.getInt32Slice()
+	for _, v := range s {
+		b = appendVarint(b, wiretag)
+		b = appendVarint(b, uint64((uint32(v)<<1)^uint32((int32(v)>>31))))
+	}
+	return b, nil
+}
+func appendZigzag32PackedSlice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := ptr.getInt32Slice()
+	if len(s) == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag&^7|WireBytes)
+	// compute size
+	n := 0
+	for _, v := range s {
+		n += SizeVarint(uint64((uint32(v) << 1) ^ uint32((int32(v) >> 31))))
+	}
+	b = appendVarint(b, uint64(n))
+	for _, v := range s {
+		b = appendVarint(b, uint64((uint32(v)<<1)^uint32((int32(v)>>31))))
+	}
+	return b, nil
+}
+func appendZigzag64Value(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toInt64()
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, uint64(v<<1)^uint64((int64(v)>>63)))
+	return b, nil
+}
+func appendZigzag64ValueNoZero(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toInt64()
+	if v == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, uint64(v<<1)^uint64((int64(v)>>63)))
+	return b, nil
+}
+func appendZigzag64Ptr(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	p := *ptr.toInt64Ptr()
+	if p == nil {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	v := *p
+	b = appendVarint(b, uint64(v<<1)^uint64((int64(v)>>63)))
+	return b, nil
+}
+func appendZigzag64Slice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := *ptr.toInt64Slice()
+	for _, v := range s {
+		b = appendVarint(b, wiretag)
+		b = appendVarint(b, uint64(v<<1)^uint64((int64(v)>>63)))
+	}
+	return b, nil
+}
+func appendZigzag64PackedSlice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := *ptr.toInt64Slice()
+	if len(s) == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag&^7|WireBytes)
+	// compute size
+	n := 0
+	for _, v := range s {
+		n += SizeVarint(uint64(v<<1) ^ uint64((int64(v) >> 63)))
+	}
+	b = appendVarint(b, uint64(n))
+	for _, v := range s {
+		b = appendVarint(b, uint64(v<<1)^uint64((int64(v)>>63)))
+	}
+	return b, nil
+}
+func appendBoolValue(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toBool()
+	b = appendVarint(b, wiretag)
+	if v {
+		b = append(b, 1)
+	} else {
+		b = append(b, 0)
+	}
+	return b, nil
+}
+func appendBoolValueNoZero(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toBool()
+	if !v {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = append(b, 1)
+	return b, nil
+}
+
+func appendBoolPtr(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	p := *ptr.toBoolPtr()
+	if p == nil {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	if *p {
+		b = append(b, 1)
+	} else {
+		b = append(b, 0)
+	}
+	return b, nil
+}
+func appendBoolSlice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := *ptr.toBoolSlice()
+	for _, v := range s {
+		b = appendVarint(b, wiretag)
+		if v {
+			b = append(b, 1)
+		} else {
+			b = append(b, 0)
+		}
+	}
+	return b, nil
+}
+func appendBoolPackedSlice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := *ptr.toBoolSlice()
+	if len(s) == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag&^7|WireBytes)
+	b = appendVarint(b, uint64(len(s)))
+	for _, v := range s {
+		if v {
+			b = append(b, 1)
+		} else {
+			b = append(b, 0)
+		}
+	}
+	return b, nil
+}
+func appendStringValue(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toString()
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, uint64(len(v)))
+	b = append(b, v...)
+	return b, nil
+}
+func appendStringValueNoZero(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toString()
+	if v == "" {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, uint64(len(v)))
+	b = append(b, v...)
+	return b, nil
+}
+func appendStringPtr(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	p := *ptr.toStringPtr()
+	if p == nil {
+		return b, nil
+	}
+	v := *p
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, uint64(len(v)))
+	b = append(b, v...)
+	return b, nil
+}
+func appendStringSlice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := *ptr.toStringSlice()
+	for _, v := range s {
+		b = appendVarint(b, wiretag)
+		b = appendVarint(b, uint64(len(v)))
+		b = append(b, v...)
+	}
+	return b, nil
+}
+func appendUTF8StringValue(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	var invalidUTF8 bool
+	v := *ptr.toString()
+	if !utf8.ValidString(v) {
+		invalidUTF8 = true
+	}
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, uint64(len(v)))
+	b = append(b, v...)
+	if invalidUTF8 {
+		return b, errInvalidUTF8
+	}
+	return b, nil
+}
+func appendUTF8StringValueNoZero(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	var invalidUTF8 bool
+	v := *ptr.toString()
+	if v == "" {
+		return b, nil
+	}
+	if !utf8.ValidString(v) {
+		invalidUTF8 = true
+	}
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, uint64(len(v)))
+	b = append(b, v...)
+	if invalidUTF8 {
+		return b, errInvalidUTF8
+	}
+	return b, nil
+}
+func appendUTF8StringPtr(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	var invalidUTF8 bool
+	p := *ptr.toStringPtr()
+	if p == nil {
+		return b, nil
+	}
+	v := *p
+	if !utf8.ValidString(v) {
+		invalidUTF8 = true
+	}
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, uint64(len(v)))
+	b = append(b, v...)
+	if invalidUTF8 {
+		return b, errInvalidUTF8
+	}
+	return b, nil
+}
+func appendUTF8StringSlice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	var invalidUTF8 bool
+	s := *ptr.toStringSlice()
+	for _, v := range s {
+		if !utf8.ValidString(v) {
+			invalidUTF8 = true
+		}
+		b = appendVarint(b, wiretag)
+		b = appendVarint(b, uint64(len(v)))
+		b = append(b, v...)
+	}
+	if invalidUTF8 {
+		return b, errInvalidUTF8
+	}
+	return b, nil
+}
+func appendBytes(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toBytes()
+	if v == nil {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, uint64(len(v)))
+	b = append(b, v...)
+	return b, nil
+}
+func appendBytes3(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toBytes()
+	if len(v) == 0 {
+		return b, nil
+	}
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, uint64(len(v)))
+	b = append(b, v...)
+	return b, nil
+}
+func appendBytesOneof(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	v := *ptr.toBytes()
+	b = appendVarint(b, wiretag)
+	b = appendVarint(b, uint64(len(v)))
+	b = append(b, v...)
+	return b, nil
+}
+func appendBytesSlice(b []byte, ptr pointer, wiretag uint64, _ bool) ([]byte, error) {
+	s := *ptr.toBytesSlice()
+	for _, v := range s {
+		b = appendVarint(b, wiretag)
+		b = appendVarint(b, uint64(len(v)))
+		b = append(b, v...)
+	}
+	return b, nil
+}
+
+// makeGroupMarshaler returns the sizer and marshaler for a group.
+// u is the marshal info of the underlying message.
+func makeGroupMarshaler(u *marshalInfo) (sizer, marshaler) {
+	return func(ptr pointer, tagsize int) int {
+			p := ptr.getPointer()
+			if p.isNil() {
+				return 0
+			}
+			return u.size(p) + 2*tagsize
+		},
+		func(b []byte, ptr pointer, wiretag uint64, deterministic bool) ([]byte, error) {
+			p := ptr.getPointer()
+			if p.isNil() {
+				return b, nil
+			}
+			var err error
+			b = appendVarint(b, wiretag) // start group
+			b, err = u.marshal(b, p, deterministic)
+			b = appendVarint(b, wiretag+(WireEndGroup-WireStartGroup)) // end group
+			return b, err
+		}
+}
+
+// makeGroupSliceMarshaler returns the sizer and marshaler for a group slice.
+// u is the marshal info of the underlying message.
+func makeGroupSliceMarshaler(u *marshalInfo) (sizer, marshaler) {
+	return func(ptr pointer, tagsize int) int {
+			s := ptr.getPointerSlice()
+			n := 0
+			for _, v := range s {
+				if v.isNil() {
+					continue
+				}
+				n += u.size(v) + 2*tagsize
+			}
+			return n
+		},
+		func(b []byte, ptr pointer, wiretag uint64, deterministic bool) ([]byte, error) {
+			s := ptr.getPointerSlice()
+			var err error
+			var nerr nonFatal
+			for _, v := range s {
+				if v.isNil() {
+					return b, errRepeatedHasNil
+				}
+				b = appendVarint(b, wiretag) // start group
+				b, err = u.marshal(b, v, deterministic)
+				b = appendVarint(b, wiretag+(WireEndGroup-WireStartGroup)) // end group
+				if !nerr.Merge(err) {
+					if err == ErrNil {
+						err = errRepeatedHasNil
+					}
+					return b, err
+				}
+			}
+			return b, nerr.E
+		}
+}
+
+// makeMessageMarshaler returns the sizer and marshaler for a message field.
+// u is the marshal info of the message.
+func makeMessageMarshaler(u *marshalInfo) (sizer, marshaler) {
+	return func(ptr pointer, tagsize int) int {
+			p := ptr.getPointer()
+			if p.isNil() {
+				return 0
+			}
+			siz := u.size(p)
+			return siz + SizeVarint(uint64(siz)) + tagsize
+		},
+		func(b []byte, ptr pointer, wiretag uint64, deterministic bool) ([]byte, error) {
+			p := ptr.getPointer()
+			if p.isNil() {
+				return b, nil
+			}
+			b = appendVarint(b, wiretag)
+			siz := u.cachedsize(p)
+			b = appendVarint(b, uint64(siz))
+			return u.marshal(b, p, deterministic)
+		}
+}
+
+// makeMessageSliceMarshaler returns the sizer and marshaler for a message slice.
+// u is the marshal info of the message.
+func makeMessageSliceMarshaler(u *marshalInfo) (sizer, marshaler) {
+	return func(ptr pointer, tagsize int) int {
+			s := ptr.getPointerSlice()
+			n := 0
+			for _, v := range s {
+				if v.isNil() {
+					continue
+				}
+				siz := u.size(v)
+				n += siz + SizeVarint(uint64(siz)) + tagsize
+			}
+			return n
+		},
+		func(b []byte, ptr pointer, wiretag uint64, deterministic bool) ([]byte, error) {
+			s := ptr.getPointerSlice()
+			var err error
+			var nerr nonFatal
+			for _, v := range s {
+				if v.isNil() {
+					return b, errRepeatedHasNil
+				}
+				b = appendVarint(b, wiretag)
+				siz := u.cachedsize(v)
+				b = appendVarint(b, uint64(siz))
+				b, err = u.marshal(b, v, deterministic)
+
+				if !nerr.Merge(err) {
+					if err == ErrNil {
+						err = errRepeatedHasNil
+					}
+					return b, err
+				}
+			}
+			return b, nerr.E
+		}
+}
+
+// makeMapMarshaler returns the sizer and marshaler for a map field.
+// f is the pointer to the reflect data structure of the field.
+func makeMapMarshaler(f *reflect.StructField) (sizer, marshaler) {
+	// figure out key and value type
+	t := f.Type
+	keyType := t.Key()
+	valType := t.Elem()
+	keyTags := strings.Split(f.Tag.Get("protobuf_key"), ",")
+	valTags := strings.Split(f.Tag.Get("protobuf_val"), ",")
+	keySizer, keyMarshaler := typeMarshaler(keyType, keyTags, false, false) // don't omit zero value in map
+	valSizer, valMarshaler := typeMarshaler(valType, valTags, false, false) // don't omit zero value in map
+	keyWireTag := 1<<3 | wiretype(keyTags[0])
+	valWireTag := 2<<3 | wiretype(valTags[0])
+
+	// We create an interface to get the addresses of the map key and value.
+	// If value is pointer-typed, the interface is a direct interface, the
+	// idata itself is the value. Otherwise, the idata is the pointer to the
+	// value.
+	// Key cannot be pointer-typed.
+	valIsPtr := valType.Kind() == reflect.Ptr
+
+	// If value is a message with nested maps, calling
+	// valSizer in marshal may be quadratic. We should use
+	// cached version in marshal (but not in size).
+	// If value is not message type, we don't have size cache,
+	// but it cannot be nested either. Just use valSizer.
+	valCachedSizer := valSizer
+	if valIsPtr && valType.Elem().Kind() == reflect.Struct {
+		u := getMarshalInfo(valType.Elem())
+		valCachedSizer = func(ptr pointer, tagsize int) int {
+			// Same as message sizer, but use cache.
+			p := ptr.getPointer()
+			if p.isNil() {
+				return 0
+			}
+			siz := u.cachedsize(p)
+			return siz + SizeVarint(uint64(siz)) + tagsize
+		}
+	}
+	return func(ptr pointer, tagsize int) int {
+			m := ptr.asPointerTo(t).Elem() // the map
+			n := 0
+			for _, k := range m.MapKeys() {
+				ki := k.Interface()
+				vi := m.MapIndex(k).Interface()
+				kaddr := toAddrPointer(&ki, false)             // pointer to key
+				vaddr := toAddrPointer(&vi, valIsPtr)          // pointer to value
+				siz := keySizer(kaddr, 1) + valSizer(vaddr, 1) // tag of key = 1 (size=1), tag of val = 2 (size=1)
+				n += siz + SizeVarint(uint64(siz)) + tagsize
+			}
+			return n
+		},
+		func(b []byte, ptr pointer, tag uint64, deterministic bool) ([]byte, error) {
+			m := ptr.asPointerTo(t).Elem() // the map
+			var err error
+			keys := m.MapKeys()
+			if len(keys) > 1 && deterministic {
+				sort.Sort(mapKeys(keys))
+			}
+
+			var nerr nonFatal
+			for _, k := range keys {
+				ki := k.Interface()
+				vi := m.MapIndex(k).Interface()
+				kaddr := toAddrPointer(&ki, false)    // pointer to key
+				vaddr := toAddrPointer(&vi, valIsPtr) // pointer to value
+				b = appendVarint(b, tag)
+				siz := keySizer(kaddr, 1) + valCachedSizer(vaddr, 1) // tag of key = 1 (size=1), tag of val = 2 (size=1)
+				b = appendVarint(b, uint64(siz))
+				b, err = keyMarshaler(b, kaddr, keyWireTag, deterministic)
+				if !nerr.Merge(err) {
+					return b, err
+				}
+				b, err = valMarshaler(b, vaddr, valWireTag, deterministic)
+				if err != ErrNil && !nerr.Merge(err) { // allow nil value in map
+					return b, err
+				}
+			}
+			return b, nerr.E
+		}
+}
+
+// makeOneOfMarshaler returns the sizer and marshaler for a oneof field.
+// fi is the marshal info of the field.
+// f is the pointer to the reflect data structure of the field.
+func makeOneOfMarshaler(fi *marshalFieldInfo, f *reflect.StructField) (sizer, marshaler) {
+	// Oneof field is an interface. We need to get the actual data type on the fly.
+	t := f.Type
+	return func(ptr pointer, _ int) int {
+			p := ptr.getInterfacePointer()
+			if p.isNil() {
+				return 0
+			}
+			v := ptr.asPointerTo(t).Elem().Elem().Elem() // *interface -> interface -> *struct -> struct
+			telem := v.Type()
+			e := fi.oneofElems[telem]
+			return e.sizer(p, e.tagsize)
+		},
+		func(b []byte, ptr pointer, _ uint64, deterministic bool) ([]byte, error) {
+			p := ptr.getInterfacePointer()
+			if p.isNil() {
+				return b, nil
+			}
+			v := ptr.asPointerTo(t).Elem().Elem().Elem() // *interface -> interface -> *struct -> struct
+			telem := v.Type()
+			if telem.Field(0).Type.Kind() == reflect.Ptr && p.getPointer().isNil() {
+				return b, errOneofHasNil
+			}
+			e := fi.oneofElems[telem]
+			return e.marshaler(b, p, e.wiretag, deterministic)
+		}
+}
+
+// sizeExtensions computes the size of encoded data for a XXX_InternalExtensions field.
+func (u *marshalInfo) sizeExtensions(ext *XXX_InternalExtensions) int {
+	m, mu := ext.extensionsRead()
+	if m == nil {
+		return 0
+	}
+	mu.Lock()
+
+	n := 0
+	for _, e := range m {
+		if e.value == nil || e.desc == nil {
+			// Extension is only in its encoded form.
+			n += len(e.enc)
+			continue
+		}
+
+		// We don't skip extensions that have an encoded form set,
+		// because the extension value may have been mutated after
+		// the last time this function was called.
+		ei := u.getExtElemInfo(e.desc)
+		v := e.value
+		p := toAddrPointer(&v, ei.isptr)
+		n += ei.sizer(p, ei.tagsize)
+	}
+	mu.Unlock()
+	return n
+}
+
+// appendExtensions marshals a XXX_InternalExtensions field to the end of byte slice b.
+func (u *marshalInfo) appendExtensions(b []byte, ext *XXX_InternalExtensions, deterministic bool) ([]byte, error) {
+	m, mu := ext.extensionsRead()
+	if m == nil {
+		return b, nil
+	}
+	mu.Lock()
+	defer mu.Unlock()
+
+	var err error
+	var nerr nonFatal
+
+	// Fast-path for common cases: zero or one extensions.
+	// Don't bother sorting the keys.
+	if len(m) <= 1 {
+		for _, e := range m {
+			if e.value == nil || e.desc == nil {
+				// Extension is only in its encoded form.
+				b = append(b, e.enc...)
+				continue
+			}
+
+			// We don't skip extensions that have an encoded form set,
+			// because the extension value may have been mutated after
+			// the last time this function was called.
+
+			ei := u.getExtElemInfo(e.desc)
+			v := e.value
+			p := toAddrPointer(&v, ei.isptr)
+			b, err = ei.marshaler(b, p, ei.wiretag, deterministic)
+			if !nerr.Merge(err) {
+				return b, err
+			}
+		}
+		return b, nerr.E
+	}
+
+	// Sort the keys to provide a deterministic encoding.
+	// Not sure this is required, but the old code does it.
+	keys := make([]int, 0, len(m))
+	for k := range m {
+		keys = append(keys, int(k))
+	}
+	sort.Ints(keys)
+
+	for _, k := range keys {
+		e := m[int32(k)]
+		if e.value == nil || e.desc == nil {
+			// Extension is only in its encoded form.
+			b = append(b, e.enc...)
+			continue
+		}
+
+		// We don't skip extensions that have an encoded form set,
+		// because the extension value may have been mutated after
+		// the last time this function was called.
+
+		ei := u.getExtElemInfo(e.desc)
+		v := e.value
+		p := toAddrPointer(&v, ei.isptr)
+		b, err = ei.marshaler(b, p, ei.wiretag, deterministic)
+		if !nerr.Merge(err) {
+			return b, err
+		}
+	}
+	return b, nerr.E
+}
+
+// message set format is:
+//   message MessageSet {
+//     repeated group Item = 1 {
+//       required int32 type_id = 2;
+//       required string message = 3;
+//     };
+//   }
+
+// sizeMessageSet computes the size of encoded data for a XXX_InternalExtensions field
+// in message set format (above).
+func (u *marshalInfo) sizeMessageSet(ext *XXX_InternalExtensions) int {
+	m, mu := ext.extensionsRead()
+	if m == nil {
+		return 0
+	}
+	mu.Lock()
+
+	n := 0
+	for id, e := range m {
+		n += 2                          // start group, end group. tag = 1 (size=1)
+		n += SizeVarint(uint64(id)) + 1 // type_id, tag = 2 (size=1)
+
+		if e.value == nil || e.desc == nil {
+			// Extension is only in its encoded form.
+			msgWithLen := skipVarint(e.enc) // skip old tag, but leave the length varint
+			siz := len(msgWithLen)
+			n += siz + 1 // message, tag = 3 (size=1)
+			continue
+		}
+
+		// We don't skip extensions that have an encoded form set,
+		// because the extension value may have been mutated after
+		// the last time this function was called.
+
+		ei := u.getExtElemInfo(e.desc)
+		v := e.value
+		p := toAddrPointer(&v, ei.isptr)
+		n += ei.sizer(p, 1) // message, tag = 3 (size=1)
+	}
+	mu.Unlock()
+	return n
+}
+
+// appendMessageSet marshals a XXX_InternalExtensions field in message set format (above)
+// to the end of byte slice b.
+func (u *marshalInfo) appendMessageSet(b []byte, ext *XXX_InternalExtensions, deterministic bool) ([]byte, error) {
+	m, mu := ext.extensionsRead()
+	if m == nil {
+		return b, nil
+	}
+	mu.Lock()
+	defer mu.Unlock()
+
+	var err error
+	var nerr nonFatal
+
+	// Fast-path for common cases: zero or one extensions.
+	// Don't bother sorting the keys.
+	if len(m) <= 1 {
+		for id, e := range m {
+			b = append(b, 1<<3|WireStartGroup)
+			b = append(b, 2<<3|WireVarint)
+			b = appendVarint(b, uint64(id))
+
+			if e.value == nil || e.desc == nil {
+				// Extension is only in its encoded form.
+				msgWithLen := skipVarint(e.enc) // skip old tag, but leave the length varint
+				b = append(b, 3<<3|WireBytes)
+				b = append(b, msgWithLen...)
+				b = append(b, 1<<3|WireEndGroup)
+				continue
+			}
+
+			// We don't skip extensions that have an encoded form set,
+			// because the extension value may have been mutated after
+			// the last time this function was called.
+
+			ei := u.getExtElemInfo(e.desc)
+			v := e.value
+			p := toAddrPointer(&v, ei.isptr)
+			b, err = ei.marshaler(b, p, 3<<3|WireBytes, deterministic)
+			if !nerr.Merge(err) {
+				return b, err
+			}
+			b = append(b, 1<<3|WireEndGroup)
+		}
+		return b, nerr.E
+	}
+
+	// Sort the keys to provide a deterministic encoding.
+	keys := make([]int, 0, len(m))
+	for k := range m {
+		keys = append(keys, int(k))
+	}
+	sort.Ints(keys)
+
+	for _, id := range keys {
+		e := m[int32(id)]
+		b = append(b, 1<<3|WireStartGroup)
+		b = append(b, 2<<3|WireVarint)
+		b = appendVarint(b, uint64(id))
+
+		if e.value == nil || e.desc == nil {
+			// Extension is only in its encoded form.
+			msgWithLen := skipVarint(e.enc) // skip old tag, but leave the length varint
+			b = append(b, 3<<3|WireBytes)
+			b = append(b, msgWithLen...)
+			b = append(b, 1<<3|WireEndGroup)
+			continue
+		}
+
+		// We don't skip extensions that have an encoded form set,
+		// because the extension value may have been mutated after
+		// the last time this function was called.
+
+		ei := u.getExtElemInfo(e.desc)
+		v := e.value
+		p := toAddrPointer(&v, ei.isptr)
+		b, err = ei.marshaler(b, p, 3<<3|WireBytes, deterministic)
+		b = append(b, 1<<3|WireEndGroup)
+		if !nerr.Merge(err) {
+			return b, err
+		}
+	}
+	return b, nerr.E
+}
+
+// sizeV1Extensions computes the size of encoded data for a V1-API extension field.
+func (u *marshalInfo) sizeV1Extensions(m map[int32]Extension) int {
+	if m == nil {
+		return 0
+	}
+
+	n := 0
+	for _, e := range m {
+		if e.value == nil || e.desc == nil {
+			// Extension is only in its encoded form.
+			n += len(e.enc)
+			continue
+		}
+
+		// We don't skip extensions that have an encoded form set,
+		// because the extension value may have been mutated after
+		// the last time this function was called.
+
+		ei := u.getExtElemInfo(e.desc)
+		v := e.value
+		p := toAddrPointer(&v, ei.isptr)
+		n += ei.sizer(p, ei.tagsize)
+	}
+	return n
+}
+
+// appendV1Extensions marshals a V1-API extension field to the end of byte slice b.
+func (u *marshalInfo) appendV1Extensions(b []byte, m map[int32]Extension, deterministic bool) ([]byte, error) {
+	if m == nil {
+		return b, nil
+	}
+
+	// Sort the keys to provide a deterministic encoding.
+	keys := make([]int, 0, len(m))
+	for k := range m {
+		keys = append(keys, int(k))
+	}
+	sort.Ints(keys)
+
+	var err error
+	var nerr nonFatal
+	for _, k := range keys {
+		e := m[int32(k)]
+		if e.value == nil || e.desc == nil {
+			// Extension is only in its encoded form.
+			b = append(b, e.enc...)
+			continue
+		}
+
+		// We don't skip extensions that have an encoded form set,
+		// because the extension value may have been mutated after
+		// the last time this function was called.
+
+		ei := u.getExtElemInfo(e.desc)
+		v := e.value
+		p := toAddrPointer(&v, ei.isptr)
+		b, err = ei.marshaler(b, p, ei.wiretag, deterministic)
+		if !nerr.Merge(err) {
+			return b, err
+		}
+	}
+	return b, nerr.E
+}
+
+// newMarshaler is the interface representing objects that can marshal themselves.
+//
+// This exists to support protoc-gen-go generated messages.
+// The proto package will stop type-asserting to this interface in the future.
+//
+// DO NOT DEPEND ON THIS.
+type newMarshaler interface {
+	XXX_Size() int
+	XXX_Marshal(b []byte, deterministic bool) ([]byte, error)
+}
+
+// Size returns the encoded size of a protocol buffer message.
+// This is the main entry point.
+func Size(pb Message) int {
+	if m, ok := pb.(newMarshaler); ok {
+		return m.XXX_Size()
+	}
+	if m, ok := pb.(Marshaler); ok {
+		// If the message can marshal itself, let it do it, for compatibility.
+		// NOTE: This is not efficient.
+		b, _ := m.Marshal()
+		return len(b)
+	}
+	// in case somehow we didn't generate the wrapper
+	if pb == nil {
+		return 0
+	}
+	var info InternalMessageInfo
+	return info.Size(pb)
+}
+
+// Marshal takes a protocol buffer message
+// and encodes it into the wire format, returning the data.
+// This is the main entry point.
+func Marshal(pb Message) ([]byte, error) {
+	if m, ok := pb.(newMarshaler); ok {
+		siz := m.XXX_Size()
+		b := make([]byte, 0, siz)
+		return m.XXX_Marshal(b, false)
+	}
+	if m, ok := pb.(Marshaler); ok {
+		// If the message can marshal itself, let it do it, for compatibility.
+		// NOTE: This is not efficient.
+		return m.Marshal()
+	}
+	// in case somehow we didn't generate the wrapper
+	if pb == nil {
+		return nil, ErrNil
+	}
+	var info InternalMessageInfo
+	siz := info.Size(pb)
+	b := make([]byte, 0, siz)
+	return info.Marshal(b, pb, false)
+}
+
+// Marshal takes a protocol buffer message
+// and encodes it into the wire format, writing the result to the
+// Buffer.
+// This is an alternative entry point. It is not necessary to use
+// a Buffer for most applications.
+func (p *Buffer) Marshal(pb Message) error {
+	var err error
+	if m, ok := pb.(newMarshaler); ok {
+		siz := m.XXX_Size()
+		p.grow(siz) // make sure buf has enough capacity
+		p.buf, err = m.XXX_Marshal(p.buf, p.deterministic)
+		return err
+	}
+	if m, ok := pb.(Marshaler); ok {
+		// If the message can marshal itself, let it do it, for compatibility.
+		// NOTE: This is not efficient.
+		b, err := m.Marshal()
+		p.buf = append(p.buf, b...)
+		return err
+	}
+	// in case somehow we didn't generate the wrapper
+	if pb == nil {
+		return ErrNil
+	}
+	var info InternalMessageInfo
+	siz := info.Size(pb)
+	p.grow(siz) // make sure buf has enough capacity
+	p.buf, err = info.Marshal(p.buf, pb, p.deterministic)
+	return err
+}
+
+// grow grows the buffer's capacity, if necessary, to guarantee space for
+// another n bytes. After grow(n), at least n bytes can be written to the
+// buffer without another allocation.
+func (p *Buffer) grow(n int) {
+	need := len(p.buf) + n
+	if need <= cap(p.buf) {
+		return
+	}
+	newCap := len(p.buf) * 2
+	if newCap < need {
+		newCap = need
+	}
+	p.buf = append(make([]byte, 0, newCap), p.buf...)
+}
diff --git a/vendor/github.com/golang/protobuf/proto/table_merge.go b/vendor/github.com/golang/protobuf/proto/table_merge.go
new file mode 100644
index 0000000..5525def
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/table_merge.go
@@ -0,0 +1,654 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2016 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package proto
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+	"sync"
+	"sync/atomic"
+)
+
+// Merge merges the src message into dst.
+// This assumes that dst and src of the same type and are non-nil.
+func (a *InternalMessageInfo) Merge(dst, src Message) {
+	mi := atomicLoadMergeInfo(&a.merge)
+	if mi == nil {
+		mi = getMergeInfo(reflect.TypeOf(dst).Elem())
+		atomicStoreMergeInfo(&a.merge, mi)
+	}
+	mi.merge(toPointer(&dst), toPointer(&src))
+}
+
+type mergeInfo struct {
+	typ reflect.Type
+
+	initialized int32 // 0: only typ is valid, 1: everything is valid
+	lock        sync.Mutex
+
+	fields       []mergeFieldInfo
+	unrecognized field // Offset of XXX_unrecognized
+}
+
+type mergeFieldInfo struct {
+	field field // Offset of field, guaranteed to be valid
+
+	// isPointer reports whether the value in the field is a pointer.
+	// This is true for the following situations:
+	//	* Pointer to struct
+	//	* Pointer to basic type (proto2 only)
+	//	* Slice (first value in slice header is a pointer)
+	//	* String (first value in string header is a pointer)
+	isPointer bool
+
+	// basicWidth reports the width of the field assuming that it is directly
+	// embedded in the struct (as is the case for basic types in proto3).
+	// The possible values are:
+	// 	0: invalid
+	//	1: bool
+	//	4: int32, uint32, float32
+	//	8: int64, uint64, float64
+	basicWidth int
+
+	// Where dst and src are pointers to the types being merged.
+	merge func(dst, src pointer)
+}
+
+var (
+	mergeInfoMap  = map[reflect.Type]*mergeInfo{}
+	mergeInfoLock sync.Mutex
+)
+
+func getMergeInfo(t reflect.Type) *mergeInfo {
+	mergeInfoLock.Lock()
+	defer mergeInfoLock.Unlock()
+	mi := mergeInfoMap[t]
+	if mi == nil {
+		mi = &mergeInfo{typ: t}
+		mergeInfoMap[t] = mi
+	}
+	return mi
+}
+
+// merge merges src into dst assuming they are both of type *mi.typ.
+func (mi *mergeInfo) merge(dst, src pointer) {
+	if dst.isNil() {
+		panic("proto: nil destination")
+	}
+	if src.isNil() {
+		return // Nothing to do.
+	}
+
+	if atomic.LoadInt32(&mi.initialized) == 0 {
+		mi.computeMergeInfo()
+	}
+
+	for _, fi := range mi.fields {
+		sfp := src.offset(fi.field)
+
+		// As an optimization, we can avoid the merge function call cost
+		// if we know for sure that the source will have no effect
+		// by checking if it is the zero value.
+		if unsafeAllowed {
+			if fi.isPointer && sfp.getPointer().isNil() { // Could be slice or string
+				continue
+			}
+			if fi.basicWidth > 0 {
+				switch {
+				case fi.basicWidth == 1 && !*sfp.toBool():
+					continue
+				case fi.basicWidth == 4 && *sfp.toUint32() == 0:
+					continue
+				case fi.basicWidth == 8 && *sfp.toUint64() == 0:
+					continue
+				}
+			}
+		}
+
+		dfp := dst.offset(fi.field)
+		fi.merge(dfp, sfp)
+	}
+
+	// TODO: Make this faster?
+	out := dst.asPointerTo(mi.typ).Elem()
+	in := src.asPointerTo(mi.typ).Elem()
+	if emIn, err := extendable(in.Addr().Interface()); err == nil {
+		emOut, _ := extendable(out.Addr().Interface())
+		mIn, muIn := emIn.extensionsRead()
+		if mIn != nil {
+			mOut := emOut.extensionsWrite()
+			muIn.Lock()
+			mergeExtension(mOut, mIn)
+			muIn.Unlock()
+		}
+	}
+
+	if mi.unrecognized.IsValid() {
+		if b := *src.offset(mi.unrecognized).toBytes(); len(b) > 0 {
+			*dst.offset(mi.unrecognized).toBytes() = append([]byte(nil), b...)
+		}
+	}
+}
+
+func (mi *mergeInfo) computeMergeInfo() {
+	mi.lock.Lock()
+	defer mi.lock.Unlock()
+	if mi.initialized != 0 {
+		return
+	}
+	t := mi.typ
+	n := t.NumField()
+
+	props := GetProperties(t)
+	for i := 0; i < n; i++ {
+		f := t.Field(i)
+		if strings.HasPrefix(f.Name, "XXX_") {
+			continue
+		}
+
+		mfi := mergeFieldInfo{field: toField(&f)}
+		tf := f.Type
+
+		// As an optimization, we can avoid the merge function call cost
+		// if we know for sure that the source will have no effect
+		// by checking if it is the zero value.
+		if unsafeAllowed {
+			switch tf.Kind() {
+			case reflect.Ptr, reflect.Slice, reflect.String:
+				// As a special case, we assume slices and strings are pointers
+				// since we know that the first field in the SliceSlice or
+				// StringHeader is a data pointer.
+				mfi.isPointer = true
+			case reflect.Bool:
+				mfi.basicWidth = 1
+			case reflect.Int32, reflect.Uint32, reflect.Float32:
+				mfi.basicWidth = 4
+			case reflect.Int64, reflect.Uint64, reflect.Float64:
+				mfi.basicWidth = 8
+			}
+		}
+
+		// Unwrap tf to get at its most basic type.
+		var isPointer, isSlice bool
+		if tf.Kind() == reflect.Slice && tf.Elem().Kind() != reflect.Uint8 {
+			isSlice = true
+			tf = tf.Elem()
+		}
+		if tf.Kind() == reflect.Ptr {
+			isPointer = true
+			tf = tf.Elem()
+		}
+		if isPointer && isSlice && tf.Kind() != reflect.Struct {
+			panic("both pointer and slice for basic type in " + tf.Name())
+		}
+
+		switch tf.Kind() {
+		case reflect.Int32:
+			switch {
+			case isSlice: // E.g., []int32
+				mfi.merge = func(dst, src pointer) {
+					// NOTE: toInt32Slice is not defined (see pointer_reflect.go).
+					/*
+						sfsp := src.toInt32Slice()
+						if *sfsp != nil {
+							dfsp := dst.toInt32Slice()
+							*dfsp = append(*dfsp, *sfsp...)
+							if *dfsp == nil {
+								*dfsp = []int64{}
+							}
+						}
+					*/
+					sfs := src.getInt32Slice()
+					if sfs != nil {
+						dfs := dst.getInt32Slice()
+						dfs = append(dfs, sfs...)
+						if dfs == nil {
+							dfs = []int32{}
+						}
+						dst.setInt32Slice(dfs)
+					}
+				}
+			case isPointer: // E.g., *int32
+				mfi.merge = func(dst, src pointer) {
+					// NOTE: toInt32Ptr is not defined (see pointer_reflect.go).
+					/*
+						sfpp := src.toInt32Ptr()
+						if *sfpp != nil {
+							dfpp := dst.toInt32Ptr()
+							if *dfpp == nil {
+								*dfpp = Int32(**sfpp)
+							} else {
+								**dfpp = **sfpp
+							}
+						}
+					*/
+					sfp := src.getInt32Ptr()
+					if sfp != nil {
+						dfp := dst.getInt32Ptr()
+						if dfp == nil {
+							dst.setInt32Ptr(*sfp)
+						} else {
+							*dfp = *sfp
+						}
+					}
+				}
+			default: // E.g., int32
+				mfi.merge = func(dst, src pointer) {
+					if v := *src.toInt32(); v != 0 {
+						*dst.toInt32() = v
+					}
+				}
+			}
+		case reflect.Int64:
+			switch {
+			case isSlice: // E.g., []int64
+				mfi.merge = func(dst, src pointer) {
+					sfsp := src.toInt64Slice()
+					if *sfsp != nil {
+						dfsp := dst.toInt64Slice()
+						*dfsp = append(*dfsp, *sfsp...)
+						if *dfsp == nil {
+							*dfsp = []int64{}
+						}
+					}
+				}
+			case isPointer: // E.g., *int64
+				mfi.merge = func(dst, src pointer) {
+					sfpp := src.toInt64Ptr()
+					if *sfpp != nil {
+						dfpp := dst.toInt64Ptr()
+						if *dfpp == nil {
+							*dfpp = Int64(**sfpp)
+						} else {
+							**dfpp = **sfpp
+						}
+					}
+				}
+			default: // E.g., int64
+				mfi.merge = func(dst, src pointer) {
+					if v := *src.toInt64(); v != 0 {
+						*dst.toInt64() = v
+					}
+				}
+			}
+		case reflect.Uint32:
+			switch {
+			case isSlice: // E.g., []uint32
+				mfi.merge = func(dst, src pointer) {
+					sfsp := src.toUint32Slice()
+					if *sfsp != nil {
+						dfsp := dst.toUint32Slice()
+						*dfsp = append(*dfsp, *sfsp...)
+						if *dfsp == nil {
+							*dfsp = []uint32{}
+						}
+					}
+				}
+			case isPointer: // E.g., *uint32
+				mfi.merge = func(dst, src pointer) {
+					sfpp := src.toUint32Ptr()
+					if *sfpp != nil {
+						dfpp := dst.toUint32Ptr()
+						if *dfpp == nil {
+							*dfpp = Uint32(**sfpp)
+						} else {
+							**dfpp = **sfpp
+						}
+					}
+				}
+			default: // E.g., uint32
+				mfi.merge = func(dst, src pointer) {
+					if v := *src.toUint32(); v != 0 {
+						*dst.toUint32() = v
+					}
+				}
+			}
+		case reflect.Uint64:
+			switch {
+			case isSlice: // E.g., []uint64
+				mfi.merge = func(dst, src pointer) {
+					sfsp := src.toUint64Slice()
+					if *sfsp != nil {
+						dfsp := dst.toUint64Slice()
+						*dfsp = append(*dfsp, *sfsp...)
+						if *dfsp == nil {
+							*dfsp = []uint64{}
+						}
+					}
+				}
+			case isPointer: // E.g., *uint64
+				mfi.merge = func(dst, src pointer) {
+					sfpp := src.toUint64Ptr()
+					if *sfpp != nil {
+						dfpp := dst.toUint64Ptr()
+						if *dfpp == nil {
+							*dfpp = Uint64(**sfpp)
+						} else {
+							**dfpp = **sfpp
+						}
+					}
+				}
+			default: // E.g., uint64
+				mfi.merge = func(dst, src pointer) {
+					if v := *src.toUint64(); v != 0 {
+						*dst.toUint64() = v
+					}
+				}
+			}
+		case reflect.Float32:
+			switch {
+			case isSlice: // E.g., []float32
+				mfi.merge = func(dst, src pointer) {
+					sfsp := src.toFloat32Slice()
+					if *sfsp != nil {
+						dfsp := dst.toFloat32Slice()
+						*dfsp = append(*dfsp, *sfsp...)
+						if *dfsp == nil {
+							*dfsp = []float32{}
+						}
+					}
+				}
+			case isPointer: // E.g., *float32
+				mfi.merge = func(dst, src pointer) {
+					sfpp := src.toFloat32Ptr()
+					if *sfpp != nil {
+						dfpp := dst.toFloat32Ptr()
+						if *dfpp == nil {
+							*dfpp = Float32(**sfpp)
+						} else {
+							**dfpp = **sfpp
+						}
+					}
+				}
+			default: // E.g., float32
+				mfi.merge = func(dst, src pointer) {
+					if v := *src.toFloat32(); v != 0 {
+						*dst.toFloat32() = v
+					}
+				}
+			}
+		case reflect.Float64:
+			switch {
+			case isSlice: // E.g., []float64
+				mfi.merge = func(dst, src pointer) {
+					sfsp := src.toFloat64Slice()
+					if *sfsp != nil {
+						dfsp := dst.toFloat64Slice()
+						*dfsp = append(*dfsp, *sfsp...)
+						if *dfsp == nil {
+							*dfsp = []float64{}
+						}
+					}
+				}
+			case isPointer: // E.g., *float64
+				mfi.merge = func(dst, src pointer) {
+					sfpp := src.toFloat64Ptr()
+					if *sfpp != nil {
+						dfpp := dst.toFloat64Ptr()
+						if *dfpp == nil {
+							*dfpp = Float64(**sfpp)
+						} else {
+							**dfpp = **sfpp
+						}
+					}
+				}
+			default: // E.g., float64
+				mfi.merge = func(dst, src pointer) {
+					if v := *src.toFloat64(); v != 0 {
+						*dst.toFloat64() = v
+					}
+				}
+			}
+		case reflect.Bool:
+			switch {
+			case isSlice: // E.g., []bool
+				mfi.merge = func(dst, src pointer) {
+					sfsp := src.toBoolSlice()
+					if *sfsp != nil {
+						dfsp := dst.toBoolSlice()
+						*dfsp = append(*dfsp, *sfsp...)
+						if *dfsp == nil {
+							*dfsp = []bool{}
+						}
+					}
+				}
+			case isPointer: // E.g., *bool
+				mfi.merge = func(dst, src pointer) {
+					sfpp := src.toBoolPtr()
+					if *sfpp != nil {
+						dfpp := dst.toBoolPtr()
+						if *dfpp == nil {
+							*dfpp = Bool(**sfpp)
+						} else {
+							**dfpp = **sfpp
+						}
+					}
+				}
+			default: // E.g., bool
+				mfi.merge = func(dst, src pointer) {
+					if v := *src.toBool(); v {
+						*dst.toBool() = v
+					}
+				}
+			}
+		case reflect.String:
+			switch {
+			case isSlice: // E.g., []string
+				mfi.merge = func(dst, src pointer) {
+					sfsp := src.toStringSlice()
+					if *sfsp != nil {
+						dfsp := dst.toStringSlice()
+						*dfsp = append(*dfsp, *sfsp...)
+						if *dfsp == nil {
+							*dfsp = []string{}
+						}
+					}
+				}
+			case isPointer: // E.g., *string
+				mfi.merge = func(dst, src pointer) {
+					sfpp := src.toStringPtr()
+					if *sfpp != nil {
+						dfpp := dst.toStringPtr()
+						if *dfpp == nil {
+							*dfpp = String(**sfpp)
+						} else {
+							**dfpp = **sfpp
+						}
+					}
+				}
+			default: // E.g., string
+				mfi.merge = func(dst, src pointer) {
+					if v := *src.toString(); v != "" {
+						*dst.toString() = v
+					}
+				}
+			}
+		case reflect.Slice:
+			isProto3 := props.Prop[i].proto3
+			switch {
+			case isPointer:
+				panic("bad pointer in byte slice case in " + tf.Name())
+			case tf.Elem().Kind() != reflect.Uint8:
+				panic("bad element kind in byte slice case in " + tf.Name())
+			case isSlice: // E.g., [][]byte
+				mfi.merge = func(dst, src pointer) {
+					sbsp := src.toBytesSlice()
+					if *sbsp != nil {
+						dbsp := dst.toBytesSlice()
+						for _, sb := range *sbsp {
+							if sb == nil {
+								*dbsp = append(*dbsp, nil)
+							} else {
+								*dbsp = append(*dbsp, append([]byte{}, sb...))
+							}
+						}
+						if *dbsp == nil {
+							*dbsp = [][]byte{}
+						}
+					}
+				}
+			default: // E.g., []byte
+				mfi.merge = func(dst, src pointer) {
+					sbp := src.toBytes()
+					if *sbp != nil {
+						dbp := dst.toBytes()
+						if !isProto3 || len(*sbp) > 0 {
+							*dbp = append([]byte{}, *sbp...)
+						}
+					}
+				}
+			}
+		case reflect.Struct:
+			switch {
+			case !isPointer:
+				panic(fmt.Sprintf("message field %s without pointer", tf))
+			case isSlice: // E.g., []*pb.T
+				mi := getMergeInfo(tf)
+				mfi.merge = func(dst, src pointer) {
+					sps := src.getPointerSlice()
+					if sps != nil {
+						dps := dst.getPointerSlice()
+						for _, sp := range sps {
+							var dp pointer
+							if !sp.isNil() {
+								dp = valToPointer(reflect.New(tf))
+								mi.merge(dp, sp)
+							}
+							dps = append(dps, dp)
+						}
+						if dps == nil {
+							dps = []pointer{}
+						}
+						dst.setPointerSlice(dps)
+					}
+				}
+			default: // E.g., *pb.T
+				mi := getMergeInfo(tf)
+				mfi.merge = func(dst, src pointer) {
+					sp := src.getPointer()
+					if !sp.isNil() {
+						dp := dst.getPointer()
+						if dp.isNil() {
+							dp = valToPointer(reflect.New(tf))
+							dst.setPointer(dp)
+						}
+						mi.merge(dp, sp)
+					}
+				}
+			}
+		case reflect.Map:
+			switch {
+			case isPointer || isSlice:
+				panic("bad pointer or slice in map case in " + tf.Name())
+			default: // E.g., map[K]V
+				mfi.merge = func(dst, src pointer) {
+					sm := src.asPointerTo(tf).Elem()
+					if sm.Len() == 0 {
+						return
+					}
+					dm := dst.asPointerTo(tf).Elem()
+					if dm.IsNil() {
+						dm.Set(reflect.MakeMap(tf))
+					}
+
+					switch tf.Elem().Kind() {
+					case reflect.Ptr: // Proto struct (e.g., *T)
+						for _, key := range sm.MapKeys() {
+							val := sm.MapIndex(key)
+							val = reflect.ValueOf(Clone(val.Interface().(Message)))
+							dm.SetMapIndex(key, val)
+						}
+					case reflect.Slice: // E.g. Bytes type (e.g., []byte)
+						for _, key := range sm.MapKeys() {
+							val := sm.MapIndex(key)
+							val = reflect.ValueOf(append([]byte{}, val.Bytes()...))
+							dm.SetMapIndex(key, val)
+						}
+					default: // Basic type (e.g., string)
+						for _, key := range sm.MapKeys() {
+							val := sm.MapIndex(key)
+							dm.SetMapIndex(key, val)
+						}
+					}
+				}
+			}
+		case reflect.Interface:
+			// Must be oneof field.
+			switch {
+			case isPointer || isSlice:
+				panic("bad pointer or slice in interface case in " + tf.Name())
+			default: // E.g., interface{}
+				// TODO: Make this faster?
+				mfi.merge = func(dst, src pointer) {
+					su := src.asPointerTo(tf).Elem()
+					if !su.IsNil() {
+						du := dst.asPointerTo(tf).Elem()
+						typ := su.Elem().Type()
+						if du.IsNil() || du.Elem().Type() != typ {
+							du.Set(reflect.New(typ.Elem())) // Initialize interface if empty
+						}
+						sv := su.Elem().Elem().Field(0)
+						if sv.Kind() == reflect.Ptr && sv.IsNil() {
+							return
+						}
+						dv := du.Elem().Elem().Field(0)
+						if dv.Kind() == reflect.Ptr && dv.IsNil() {
+							dv.Set(reflect.New(sv.Type().Elem())) // Initialize proto message if empty
+						}
+						switch sv.Type().Kind() {
+						case reflect.Ptr: // Proto struct (e.g., *T)
+							Merge(dv.Interface().(Message), sv.Interface().(Message))
+						case reflect.Slice: // E.g. Bytes type (e.g., []byte)
+							dv.Set(reflect.ValueOf(append([]byte{}, sv.Bytes()...)))
+						default: // Basic type (e.g., string)
+							dv.Set(sv)
+						}
+					}
+				}
+			}
+		default:
+			panic(fmt.Sprintf("merger not found for type:%s", tf))
+		}
+		mi.fields = append(mi.fields, mfi)
+	}
+
+	mi.unrecognized = invalidField
+	if f, ok := t.FieldByName("XXX_unrecognized"); ok {
+		if f.Type != reflect.TypeOf([]byte{}) {
+			panic("expected XXX_unrecognized to be of type []byte")
+		}
+		mi.unrecognized = toField(&f)
+	}
+
+	atomic.StoreInt32(&mi.initialized, 1)
+}
diff --git a/vendor/github.com/golang/protobuf/proto/table_unmarshal.go b/vendor/github.com/golang/protobuf/proto/table_unmarshal.go
new file mode 100644
index 0000000..ebf1caa
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/table_unmarshal.go
@@ -0,0 +1,2051 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2016 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package proto
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"math"
+	"reflect"
+	"strconv"
+	"strings"
+	"sync"
+	"sync/atomic"
+	"unicode/utf8"
+)
+
+// Unmarshal is the entry point from the generated .pb.go files.
+// This function is not intended to be used by non-generated code.
+// This function is not subject to any compatibility guarantee.
+// msg contains a pointer to a protocol buffer struct.
+// b is the data to be unmarshaled into the protocol buffer.
+// a is a pointer to a place to store cached unmarshal information.
+func (a *InternalMessageInfo) Unmarshal(msg Message, b []byte) error {
+	// Load the unmarshal information for this message type.
+	// The atomic load ensures memory consistency.
+	u := atomicLoadUnmarshalInfo(&a.unmarshal)
+	if u == nil {
+		// Slow path: find unmarshal info for msg, update a with it.
+		u = getUnmarshalInfo(reflect.TypeOf(msg).Elem())
+		atomicStoreUnmarshalInfo(&a.unmarshal, u)
+	}
+	// Then do the unmarshaling.
+	err := u.unmarshal(toPointer(&msg), b)
+	return err
+}
+
+type unmarshalInfo struct {
+	typ reflect.Type // type of the protobuf struct
+
+	// 0 = only typ field is initialized
+	// 1 = completely initialized
+	initialized     int32
+	lock            sync.Mutex                    // prevents double initialization
+	dense           []unmarshalFieldInfo          // fields indexed by tag #
+	sparse          map[uint64]unmarshalFieldInfo // fields indexed by tag #
+	reqFields       []string                      // names of required fields
+	reqMask         uint64                        // 1<<len(reqFields)-1
+	unrecognized    field                         // offset of []byte to put unrecognized data (or invalidField if we should throw it away)
+	extensions      field                         // offset of extensions field (of type proto.XXX_InternalExtensions), or invalidField if it does not exist
+	oldExtensions   field                         // offset of old-form extensions field (of type map[int]Extension)
+	extensionRanges []ExtensionRange              // if non-nil, implies extensions field is valid
+	isMessageSet    bool                          // if true, implies extensions field is valid
+}
+
+// An unmarshaler takes a stream of bytes and a pointer to a field of a message.
+// It decodes the field, stores it at f, and returns the unused bytes.
+// w is the wire encoding.
+// b is the data after the tag and wire encoding have been read.
+type unmarshaler func(b []byte, f pointer, w int) ([]byte, error)
+
+type unmarshalFieldInfo struct {
+	// location of the field in the proto message structure.
+	field field
+
+	// function to unmarshal the data for the field.
+	unmarshal unmarshaler
+
+	// if a required field, contains a single set bit at this field's index in the required field list.
+	reqMask uint64
+
+	name string // name of the field, for error reporting
+}
+
+var (
+	unmarshalInfoMap  = map[reflect.Type]*unmarshalInfo{}
+	unmarshalInfoLock sync.Mutex
+)
+
+// getUnmarshalInfo returns the data structure which can be
+// subsequently used to unmarshal a message of the given type.
+// t is the type of the message (note: not pointer to message).
+func getUnmarshalInfo(t reflect.Type) *unmarshalInfo {
+	// It would be correct to return a new unmarshalInfo
+	// unconditionally. We would end up allocating one
+	// per occurrence of that type as a message or submessage.
+	// We use a cache here just to reduce memory usage.
+	unmarshalInfoLock.Lock()
+	defer unmarshalInfoLock.Unlock()
+	u := unmarshalInfoMap[t]
+	if u == nil {
+		u = &unmarshalInfo{typ: t}
+		// Note: we just set the type here. The rest of the fields
+		// will be initialized on first use.
+		unmarshalInfoMap[t] = u
+	}
+	return u
+}
+
+// unmarshal does the main work of unmarshaling a message.
+// u provides type information used to unmarshal the message.
+// m is a pointer to a protocol buffer message.
+// b is a byte stream to unmarshal into m.
+// This is top routine used when recursively unmarshaling submessages.
+func (u *unmarshalInfo) unmarshal(m pointer, b []byte) error {
+	if atomic.LoadInt32(&u.initialized) == 0 {
+		u.computeUnmarshalInfo()
+	}
+	if u.isMessageSet {
+		return UnmarshalMessageSet(b, m.offset(u.extensions).toExtensions())
+	}
+	var reqMask uint64 // bitmask of required fields we've seen.
+	var errLater error
+	for len(b) > 0 {
+		// Read tag and wire type.
+		// Special case 1 and 2 byte varints.
+		var x uint64
+		if b[0] < 128 {
+			x = uint64(b[0])
+			b = b[1:]
+		} else if len(b) >= 2 && b[1] < 128 {
+			x = uint64(b[0]&0x7f) + uint64(b[1])<<7
+			b = b[2:]
+		} else {
+			var n int
+			x, n = decodeVarint(b)
+			if n == 0 {
+				return io.ErrUnexpectedEOF
+			}
+			b = b[n:]
+		}
+		tag := x >> 3
+		wire := int(x) & 7
+
+		// Dispatch on the tag to one of the unmarshal* functions below.
+		var f unmarshalFieldInfo
+		if tag < uint64(len(u.dense)) {
+			f = u.dense[tag]
+		} else {
+			f = u.sparse[tag]
+		}
+		if fn := f.unmarshal; fn != nil {
+			var err error
+			b, err = fn(b, m.offset(f.field), wire)
+			if err == nil {
+				reqMask |= f.reqMask
+				continue
+			}
+			if r, ok := err.(*RequiredNotSetError); ok {
+				// Remember this error, but keep parsing. We need to produce
+				// a full parse even if a required field is missing.
+				if errLater == nil {
+					errLater = r
+				}
+				reqMask |= f.reqMask
+				continue
+			}
+			if err != errInternalBadWireType {
+				if err == errInvalidUTF8 {
+					if errLater == nil {
+						fullName := revProtoTypes[reflect.PtrTo(u.typ)] + "." + f.name
+						errLater = &invalidUTF8Error{fullName}
+					}
+					continue
+				}
+				return err
+			}
+			// Fragments with bad wire type are treated as unknown fields.
+		}
+
+		// Unknown tag.
+		if !u.unrecognized.IsValid() {
+			// Don't keep unrecognized data; just skip it.
+			var err error
+			b, err = skipField(b, wire)
+			if err != nil {
+				return err
+			}
+			continue
+		}
+		// Keep unrecognized data around.
+		// maybe in extensions, maybe in the unrecognized field.
+		z := m.offset(u.unrecognized).toBytes()
+		var emap map[int32]Extension
+		var e Extension
+		for _, r := range u.extensionRanges {
+			if uint64(r.Start) <= tag && tag <= uint64(r.End) {
+				if u.extensions.IsValid() {
+					mp := m.offset(u.extensions).toExtensions()
+					emap = mp.extensionsWrite()
+					e = emap[int32(tag)]
+					z = &e.enc
+					break
+				}
+				if u.oldExtensions.IsValid() {
+					p := m.offset(u.oldExtensions).toOldExtensions()
+					emap = *p
+					if emap == nil {
+						emap = map[int32]Extension{}
+						*p = emap
+					}
+					e = emap[int32(tag)]
+					z = &e.enc
+					break
+				}
+				panic("no extensions field available")
+			}
+		}
+
+		// Use wire type to skip data.
+		var err error
+		b0 := b
+		b, err = skipField(b, wire)
+		if err != nil {
+			return err
+		}
+		*z = encodeVarint(*z, tag<<3|uint64(wire))
+		*z = append(*z, b0[:len(b0)-len(b)]...)
+
+		if emap != nil {
+			emap[int32(tag)] = e
+		}
+	}
+	if reqMask != u.reqMask && errLater == nil {
+		// A required field of this message is missing.
+		for _, n := range u.reqFields {
+			if reqMask&1 == 0 {
+				errLater = &RequiredNotSetError{n}
+			}
+			reqMask >>= 1
+		}
+	}
+	return errLater
+}
+
+// computeUnmarshalInfo fills in u with information for use
+// in unmarshaling protocol buffers of type u.typ.
+func (u *unmarshalInfo) computeUnmarshalInfo() {
+	u.lock.Lock()
+	defer u.lock.Unlock()
+	if u.initialized != 0 {
+		return
+	}
+	t := u.typ
+	n := t.NumField()
+
+	// Set up the "not found" value for the unrecognized byte buffer.
+	// This is the default for proto3.
+	u.unrecognized = invalidField
+	u.extensions = invalidField
+	u.oldExtensions = invalidField
+
+	// List of the generated type and offset for each oneof field.
+	type oneofField struct {
+		ityp  reflect.Type // interface type of oneof field
+		field field        // offset in containing message
+	}
+	var oneofFields []oneofField
+
+	for i := 0; i < n; i++ {
+		f := t.Field(i)
+		if f.Name == "XXX_unrecognized" {
+			// The byte slice used to hold unrecognized input is special.
+			if f.Type != reflect.TypeOf(([]byte)(nil)) {
+				panic("bad type for XXX_unrecognized field: " + f.Type.Name())
+			}
+			u.unrecognized = toField(&f)
+			continue
+		}
+		if f.Name == "XXX_InternalExtensions" {
+			// Ditto here.
+			if f.Type != reflect.TypeOf(XXX_InternalExtensions{}) {
+				panic("bad type for XXX_InternalExtensions field: " + f.Type.Name())
+			}
+			u.extensions = toField(&f)
+			if f.Tag.Get("protobuf_messageset") == "1" {
+				u.isMessageSet = true
+			}
+			continue
+		}
+		if f.Name == "XXX_extensions" {
+			// An older form of the extensions field.
+			if f.Type != reflect.TypeOf((map[int32]Extension)(nil)) {
+				panic("bad type for XXX_extensions field: " + f.Type.Name())
+			}
+			u.oldExtensions = toField(&f)
+			continue
+		}
+		if f.Name == "XXX_NoUnkeyedLiteral" || f.Name == "XXX_sizecache" {
+			continue
+		}
+
+		oneof := f.Tag.Get("protobuf_oneof")
+		if oneof != "" {
+			oneofFields = append(oneofFields, oneofField{f.Type, toField(&f)})
+			// The rest of oneof processing happens below.
+			continue
+		}
+
+		tags := f.Tag.Get("protobuf")
+		tagArray := strings.Split(tags, ",")
+		if len(tagArray) < 2 {
+			panic("protobuf tag not enough fields in " + t.Name() + "." + f.Name + ": " + tags)
+		}
+		tag, err := strconv.Atoi(tagArray[1])
+		if err != nil {
+			panic("protobuf tag field not an integer: " + tagArray[1])
+		}
+
+		name := ""
+		for _, tag := range tagArray[3:] {
+			if strings.HasPrefix(tag, "name=") {
+				name = tag[5:]
+			}
+		}
+
+		// Extract unmarshaling function from the field (its type and tags).
+		unmarshal := fieldUnmarshaler(&f)
+
+		// Required field?
+		var reqMask uint64
+		if tagArray[2] == "req" {
+			bit := len(u.reqFields)
+			u.reqFields = append(u.reqFields, name)
+			reqMask = uint64(1) << uint(bit)
+			// TODO: if we have more than 64 required fields, we end up
+			// not verifying that all required fields are present.
+			// Fix this, perhaps using a count of required fields?
+		}
+
+		// Store the info in the correct slot in the message.
+		u.setTag(tag, toField(&f), unmarshal, reqMask, name)
+	}
+
+	// Find any types associated with oneof fields.
+	// TODO: XXX_OneofFuncs returns more info than we need.  Get rid of some of it?
+	fn := reflect.Zero(reflect.PtrTo(t)).MethodByName("XXX_OneofFuncs")
+	if fn.IsValid() {
+		res := fn.Call(nil)[3] // last return value from XXX_OneofFuncs: []interface{}
+		for i := res.Len() - 1; i >= 0; i-- {
+			v := res.Index(i)                             // interface{}
+			tptr := reflect.ValueOf(v.Interface()).Type() // *Msg_X
+			typ := tptr.Elem()                            // Msg_X
+
+			f := typ.Field(0) // oneof implementers have one field
+			baseUnmarshal := fieldUnmarshaler(&f)
+			tags := strings.Split(f.Tag.Get("protobuf"), ",")
+			fieldNum, err := strconv.Atoi(tags[1])
+			if err != nil {
+				panic("protobuf tag field not an integer: " + tags[1])
+			}
+			var name string
+			for _, tag := range tags {
+				if strings.HasPrefix(tag, "name=") {
+					name = strings.TrimPrefix(tag, "name=")
+					break
+				}
+			}
+
+			// Find the oneof field that this struct implements.
+			// Might take O(n^2) to process all of the oneofs, but who cares.
+			for _, of := range oneofFields {
+				if tptr.Implements(of.ityp) {
+					// We have found the corresponding interface for this struct.
+					// That lets us know where this struct should be stored
+					// when we encounter it during unmarshaling.
+					unmarshal := makeUnmarshalOneof(typ, of.ityp, baseUnmarshal)
+					u.setTag(fieldNum, of.field, unmarshal, 0, name)
+				}
+			}
+		}
+	}
+
+	// Get extension ranges, if any.
+	fn = reflect.Zero(reflect.PtrTo(t)).MethodByName("ExtensionRangeArray")
+	if fn.IsValid() {
+		if !u.extensions.IsValid() && !u.oldExtensions.IsValid() {
+			panic("a message with extensions, but no extensions field in " + t.Name())
+		}
+		u.extensionRanges = fn.Call(nil)[0].Interface().([]ExtensionRange)
+	}
+
+	// Explicitly disallow tag 0. This will ensure we flag an error
+	// when decoding a buffer of all zeros. Without this code, we
+	// would decode and skip an all-zero buffer of even length.
+	// [0 0] is [tag=0/wiretype=varint varint-encoded-0].
+	u.setTag(0, zeroField, func(b []byte, f pointer, w int) ([]byte, error) {
+		return nil, fmt.Errorf("proto: %s: illegal tag 0 (wire type %d)", t, w)
+	}, 0, "")
+
+	// Set mask for required field check.
+	u.reqMask = uint64(1)<<uint(len(u.reqFields)) - 1
+
+	atomic.StoreInt32(&u.initialized, 1)
+}
+
+// setTag stores the unmarshal information for the given tag.
+// tag = tag # for field
+// field/unmarshal = unmarshal info for that field.
+// reqMask = if required, bitmask for field position in required field list. 0 otherwise.
+// name = short name of the field.
+func (u *unmarshalInfo) setTag(tag int, field field, unmarshal unmarshaler, reqMask uint64, name string) {
+	i := unmarshalFieldInfo{field: field, unmarshal: unmarshal, reqMask: reqMask, name: name}
+	n := u.typ.NumField()
+	if tag >= 0 && (tag < 16 || tag < 2*n) { // TODO: what are the right numbers here?
+		for len(u.dense) <= tag {
+			u.dense = append(u.dense, unmarshalFieldInfo{})
+		}
+		u.dense[tag] = i
+		return
+	}
+	if u.sparse == nil {
+		u.sparse = map[uint64]unmarshalFieldInfo{}
+	}
+	u.sparse[uint64(tag)] = i
+}
+
+// fieldUnmarshaler returns an unmarshaler for the given field.
+func fieldUnmarshaler(f *reflect.StructField) unmarshaler {
+	if f.Type.Kind() == reflect.Map {
+		return makeUnmarshalMap(f)
+	}
+	return typeUnmarshaler(f.Type, f.Tag.Get("protobuf"))
+}
+
+// typeUnmarshaler returns an unmarshaler for the given field type / field tag pair.
+func typeUnmarshaler(t reflect.Type, tags string) unmarshaler {
+	tagArray := strings.Split(tags, ",")
+	encoding := tagArray[0]
+	name := "unknown"
+	proto3 := false
+	validateUTF8 := true
+	for _, tag := range tagArray[3:] {
+		if strings.HasPrefix(tag, "name=") {
+			name = tag[5:]
+		}
+		if tag == "proto3" {
+			proto3 = true
+		}
+	}
+	validateUTF8 = validateUTF8 && proto3
+
+	// Figure out packaging (pointer, slice, or both)
+	slice := false
+	pointer := false
+	if t.Kind() == reflect.Slice && t.Elem().Kind() != reflect.Uint8 {
+		slice = true
+		t = t.Elem()
+	}
+	if t.Kind() == reflect.Ptr {
+		pointer = true
+		t = t.Elem()
+	}
+
+	// We'll never have both pointer and slice for basic types.
+	if pointer && slice && t.Kind() != reflect.Struct {
+		panic("both pointer and slice for basic type in " + t.Name())
+	}
+
+	switch t.Kind() {
+	case reflect.Bool:
+		if pointer {
+			return unmarshalBoolPtr
+		}
+		if slice {
+			return unmarshalBoolSlice
+		}
+		return unmarshalBoolValue
+	case reflect.Int32:
+		switch encoding {
+		case "fixed32":
+			if pointer {
+				return unmarshalFixedS32Ptr
+			}
+			if slice {
+				return unmarshalFixedS32Slice
+			}
+			return unmarshalFixedS32Value
+		case "varint":
+			// this could be int32 or enum
+			if pointer {
+				return unmarshalInt32Ptr
+			}
+			if slice {
+				return unmarshalInt32Slice
+			}
+			return unmarshalInt32Value
+		case "zigzag32":
+			if pointer {
+				return unmarshalSint32Ptr
+			}
+			if slice {
+				return unmarshalSint32Slice
+			}
+			return unmarshalSint32Value
+		}
+	case reflect.Int64:
+		switch encoding {
+		case "fixed64":
+			if pointer {
+				return unmarshalFixedS64Ptr
+			}
+			if slice {
+				return unmarshalFixedS64Slice
+			}
+			return unmarshalFixedS64Value
+		case "varint":
+			if pointer {
+				return unmarshalInt64Ptr
+			}
+			if slice {
+				return unmarshalInt64Slice
+			}
+			return unmarshalInt64Value
+		case "zigzag64":
+			if pointer {
+				return unmarshalSint64Ptr
+			}
+			if slice {
+				return unmarshalSint64Slice
+			}
+			return unmarshalSint64Value
+		}
+	case reflect.Uint32:
+		switch encoding {
+		case "fixed32":
+			if pointer {
+				return unmarshalFixed32Ptr
+			}
+			if slice {
+				return unmarshalFixed32Slice
+			}
+			return unmarshalFixed32Value
+		case "varint":
+			if pointer {
+				return unmarshalUint32Ptr
+			}
+			if slice {
+				return unmarshalUint32Slice
+			}
+			return unmarshalUint32Value
+		}
+	case reflect.Uint64:
+		switch encoding {
+		case "fixed64":
+			if pointer {
+				return unmarshalFixed64Ptr
+			}
+			if slice {
+				return unmarshalFixed64Slice
+			}
+			return unmarshalFixed64Value
+		case "varint":
+			if pointer {
+				return unmarshalUint64Ptr
+			}
+			if slice {
+				return unmarshalUint64Slice
+			}
+			return unmarshalUint64Value
+		}
+	case reflect.Float32:
+		if pointer {
+			return unmarshalFloat32Ptr
+		}
+		if slice {
+			return unmarshalFloat32Slice
+		}
+		return unmarshalFloat32Value
+	case reflect.Float64:
+		if pointer {
+			return unmarshalFloat64Ptr
+		}
+		if slice {
+			return unmarshalFloat64Slice
+		}
+		return unmarshalFloat64Value
+	case reflect.Map:
+		panic("map type in typeUnmarshaler in " + t.Name())
+	case reflect.Slice:
+		if pointer {
+			panic("bad pointer in slice case in " + t.Name())
+		}
+		if slice {
+			return unmarshalBytesSlice
+		}
+		return unmarshalBytesValue
+	case reflect.String:
+		if validateUTF8 {
+			if pointer {
+				return unmarshalUTF8StringPtr
+			}
+			if slice {
+				return unmarshalUTF8StringSlice
+			}
+			return unmarshalUTF8StringValue
+		}
+		if pointer {
+			return unmarshalStringPtr
+		}
+		if slice {
+			return unmarshalStringSlice
+		}
+		return unmarshalStringValue
+	case reflect.Struct:
+		// message or group field
+		if !pointer {
+			panic(fmt.Sprintf("message/group field %s:%s without pointer", t, encoding))
+		}
+		switch encoding {
+		case "bytes":
+			if slice {
+				return makeUnmarshalMessageSlicePtr(getUnmarshalInfo(t), name)
+			}
+			return makeUnmarshalMessagePtr(getUnmarshalInfo(t), name)
+		case "group":
+			if slice {
+				return makeUnmarshalGroupSlicePtr(getUnmarshalInfo(t), name)
+			}
+			return makeUnmarshalGroupPtr(getUnmarshalInfo(t), name)
+		}
+	}
+	panic(fmt.Sprintf("unmarshaler not found type:%s encoding:%s", t, encoding))
+}
+
+// Below are all the unmarshalers for individual fields of various types.
+
+func unmarshalInt64Value(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireVarint {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	v := int64(x)
+	*f.toInt64() = v
+	return b, nil
+}
+
+func unmarshalInt64Ptr(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireVarint {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	v := int64(x)
+	*f.toInt64Ptr() = &v
+	return b, nil
+}
+
+func unmarshalInt64Slice(b []byte, f pointer, w int) ([]byte, error) {
+	if w == WireBytes { // packed
+		x, n := decodeVarint(b)
+		if n == 0 {
+			return nil, io.ErrUnexpectedEOF
+		}
+		b = b[n:]
+		if x > uint64(len(b)) {
+			return nil, io.ErrUnexpectedEOF
+		}
+		res := b[x:]
+		b = b[:x]
+		for len(b) > 0 {
+			x, n = decodeVarint(b)
+			if n == 0 {
+				return nil, io.ErrUnexpectedEOF
+			}
+			b = b[n:]
+			v := int64(x)
+			s := f.toInt64Slice()
+			*s = append(*s, v)
+		}
+		return res, nil
+	}
+	if w != WireVarint {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	v := int64(x)
+	s := f.toInt64Slice()
+	*s = append(*s, v)
+	return b, nil
+}
+
+func unmarshalSint64Value(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireVarint {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	v := int64(x>>1) ^ int64(x)<<63>>63
+	*f.toInt64() = v
+	return b, nil
+}
+
+func unmarshalSint64Ptr(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireVarint {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	v := int64(x>>1) ^ int64(x)<<63>>63
+	*f.toInt64Ptr() = &v
+	return b, nil
+}
+
+func unmarshalSint64Slice(b []byte, f pointer, w int) ([]byte, error) {
+	if w == WireBytes { // packed
+		x, n := decodeVarint(b)
+		if n == 0 {
+			return nil, io.ErrUnexpectedEOF
+		}
+		b = b[n:]
+		if x > uint64(len(b)) {
+			return nil, io.ErrUnexpectedEOF
+		}
+		res := b[x:]
+		b = b[:x]
+		for len(b) > 0 {
+			x, n = decodeVarint(b)
+			if n == 0 {
+				return nil, io.ErrUnexpectedEOF
+			}
+			b = b[n:]
+			v := int64(x>>1) ^ int64(x)<<63>>63
+			s := f.toInt64Slice()
+			*s = append(*s, v)
+		}
+		return res, nil
+	}
+	if w != WireVarint {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	v := int64(x>>1) ^ int64(x)<<63>>63
+	s := f.toInt64Slice()
+	*s = append(*s, v)
+	return b, nil
+}
+
+func unmarshalUint64Value(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireVarint {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	v := uint64(x)
+	*f.toUint64() = v
+	return b, nil
+}
+
+func unmarshalUint64Ptr(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireVarint {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	v := uint64(x)
+	*f.toUint64Ptr() = &v
+	return b, nil
+}
+
+func unmarshalUint64Slice(b []byte, f pointer, w int) ([]byte, error) {
+	if w == WireBytes { // packed
+		x, n := decodeVarint(b)
+		if n == 0 {
+			return nil, io.ErrUnexpectedEOF
+		}
+		b = b[n:]
+		if x > uint64(len(b)) {
+			return nil, io.ErrUnexpectedEOF
+		}
+		res := b[x:]
+		b = b[:x]
+		for len(b) > 0 {
+			x, n = decodeVarint(b)
+			if n == 0 {
+				return nil, io.ErrUnexpectedEOF
+			}
+			b = b[n:]
+			v := uint64(x)
+			s := f.toUint64Slice()
+			*s = append(*s, v)
+		}
+		return res, nil
+	}
+	if w != WireVarint {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	v := uint64(x)
+	s := f.toUint64Slice()
+	*s = append(*s, v)
+	return b, nil
+}
+
+func unmarshalInt32Value(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireVarint {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	v := int32(x)
+	*f.toInt32() = v
+	return b, nil
+}
+
+func unmarshalInt32Ptr(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireVarint {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	v := int32(x)
+	f.setInt32Ptr(v)
+	return b, nil
+}
+
+func unmarshalInt32Slice(b []byte, f pointer, w int) ([]byte, error) {
+	if w == WireBytes { // packed
+		x, n := decodeVarint(b)
+		if n == 0 {
+			return nil, io.ErrUnexpectedEOF
+		}
+		b = b[n:]
+		if x > uint64(len(b)) {
+			return nil, io.ErrUnexpectedEOF
+		}
+		res := b[x:]
+		b = b[:x]
+		for len(b) > 0 {
+			x, n = decodeVarint(b)
+			if n == 0 {
+				return nil, io.ErrUnexpectedEOF
+			}
+			b = b[n:]
+			v := int32(x)
+			f.appendInt32Slice(v)
+		}
+		return res, nil
+	}
+	if w != WireVarint {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	v := int32(x)
+	f.appendInt32Slice(v)
+	return b, nil
+}
+
+func unmarshalSint32Value(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireVarint {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	v := int32(x>>1) ^ int32(x)<<31>>31
+	*f.toInt32() = v
+	return b, nil
+}
+
+func unmarshalSint32Ptr(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireVarint {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	v := int32(x>>1) ^ int32(x)<<31>>31
+	f.setInt32Ptr(v)
+	return b, nil
+}
+
+func unmarshalSint32Slice(b []byte, f pointer, w int) ([]byte, error) {
+	if w == WireBytes { // packed
+		x, n := decodeVarint(b)
+		if n == 0 {
+			return nil, io.ErrUnexpectedEOF
+		}
+		b = b[n:]
+		if x > uint64(len(b)) {
+			return nil, io.ErrUnexpectedEOF
+		}
+		res := b[x:]
+		b = b[:x]
+		for len(b) > 0 {
+			x, n = decodeVarint(b)
+			if n == 0 {
+				return nil, io.ErrUnexpectedEOF
+			}
+			b = b[n:]
+			v := int32(x>>1) ^ int32(x)<<31>>31
+			f.appendInt32Slice(v)
+		}
+		return res, nil
+	}
+	if w != WireVarint {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	v := int32(x>>1) ^ int32(x)<<31>>31
+	f.appendInt32Slice(v)
+	return b, nil
+}
+
+func unmarshalUint32Value(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireVarint {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	v := uint32(x)
+	*f.toUint32() = v
+	return b, nil
+}
+
+func unmarshalUint32Ptr(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireVarint {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	v := uint32(x)
+	*f.toUint32Ptr() = &v
+	return b, nil
+}
+
+func unmarshalUint32Slice(b []byte, f pointer, w int) ([]byte, error) {
+	if w == WireBytes { // packed
+		x, n := decodeVarint(b)
+		if n == 0 {
+			return nil, io.ErrUnexpectedEOF
+		}
+		b = b[n:]
+		if x > uint64(len(b)) {
+			return nil, io.ErrUnexpectedEOF
+		}
+		res := b[x:]
+		b = b[:x]
+		for len(b) > 0 {
+			x, n = decodeVarint(b)
+			if n == 0 {
+				return nil, io.ErrUnexpectedEOF
+			}
+			b = b[n:]
+			v := uint32(x)
+			s := f.toUint32Slice()
+			*s = append(*s, v)
+		}
+		return res, nil
+	}
+	if w != WireVarint {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	v := uint32(x)
+	s := f.toUint32Slice()
+	*s = append(*s, v)
+	return b, nil
+}
+
+func unmarshalFixed64Value(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireFixed64 {
+		return b, errInternalBadWireType
+	}
+	if len(b) < 8 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56
+	*f.toUint64() = v
+	return b[8:], nil
+}
+
+func unmarshalFixed64Ptr(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireFixed64 {
+		return b, errInternalBadWireType
+	}
+	if len(b) < 8 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56
+	*f.toUint64Ptr() = &v
+	return b[8:], nil
+}
+
+func unmarshalFixed64Slice(b []byte, f pointer, w int) ([]byte, error) {
+	if w == WireBytes { // packed
+		x, n := decodeVarint(b)
+		if n == 0 {
+			return nil, io.ErrUnexpectedEOF
+		}
+		b = b[n:]
+		if x > uint64(len(b)) {
+			return nil, io.ErrUnexpectedEOF
+		}
+		res := b[x:]
+		b = b[:x]
+		for len(b) > 0 {
+			if len(b) < 8 {
+				return nil, io.ErrUnexpectedEOF
+			}
+			v := uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56
+			s := f.toUint64Slice()
+			*s = append(*s, v)
+			b = b[8:]
+		}
+		return res, nil
+	}
+	if w != WireFixed64 {
+		return b, errInternalBadWireType
+	}
+	if len(b) < 8 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56
+	s := f.toUint64Slice()
+	*s = append(*s, v)
+	return b[8:], nil
+}
+
+func unmarshalFixedS64Value(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireFixed64 {
+		return b, errInternalBadWireType
+	}
+	if len(b) < 8 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := int64(b[0]) | int64(b[1])<<8 | int64(b[2])<<16 | int64(b[3])<<24 | int64(b[4])<<32 | int64(b[5])<<40 | int64(b[6])<<48 | int64(b[7])<<56
+	*f.toInt64() = v
+	return b[8:], nil
+}
+
+func unmarshalFixedS64Ptr(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireFixed64 {
+		return b, errInternalBadWireType
+	}
+	if len(b) < 8 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := int64(b[0]) | int64(b[1])<<8 | int64(b[2])<<16 | int64(b[3])<<24 | int64(b[4])<<32 | int64(b[5])<<40 | int64(b[6])<<48 | int64(b[7])<<56
+	*f.toInt64Ptr() = &v
+	return b[8:], nil
+}
+
+func unmarshalFixedS64Slice(b []byte, f pointer, w int) ([]byte, error) {
+	if w == WireBytes { // packed
+		x, n := decodeVarint(b)
+		if n == 0 {
+			return nil, io.ErrUnexpectedEOF
+		}
+		b = b[n:]
+		if x > uint64(len(b)) {
+			return nil, io.ErrUnexpectedEOF
+		}
+		res := b[x:]
+		b = b[:x]
+		for len(b) > 0 {
+			if len(b) < 8 {
+				return nil, io.ErrUnexpectedEOF
+			}
+			v := int64(b[0]) | int64(b[1])<<8 | int64(b[2])<<16 | int64(b[3])<<24 | int64(b[4])<<32 | int64(b[5])<<40 | int64(b[6])<<48 | int64(b[7])<<56
+			s := f.toInt64Slice()
+			*s = append(*s, v)
+			b = b[8:]
+		}
+		return res, nil
+	}
+	if w != WireFixed64 {
+		return b, errInternalBadWireType
+	}
+	if len(b) < 8 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := int64(b[0]) | int64(b[1])<<8 | int64(b[2])<<16 | int64(b[3])<<24 | int64(b[4])<<32 | int64(b[5])<<40 | int64(b[6])<<48 | int64(b[7])<<56
+	s := f.toInt64Slice()
+	*s = append(*s, v)
+	return b[8:], nil
+}
+
+func unmarshalFixed32Value(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireFixed32 {
+		return b, errInternalBadWireType
+	}
+	if len(b) < 4 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
+	*f.toUint32() = v
+	return b[4:], nil
+}
+
+func unmarshalFixed32Ptr(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireFixed32 {
+		return b, errInternalBadWireType
+	}
+	if len(b) < 4 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
+	*f.toUint32Ptr() = &v
+	return b[4:], nil
+}
+
+func unmarshalFixed32Slice(b []byte, f pointer, w int) ([]byte, error) {
+	if w == WireBytes { // packed
+		x, n := decodeVarint(b)
+		if n == 0 {
+			return nil, io.ErrUnexpectedEOF
+		}
+		b = b[n:]
+		if x > uint64(len(b)) {
+			return nil, io.ErrUnexpectedEOF
+		}
+		res := b[x:]
+		b = b[:x]
+		for len(b) > 0 {
+			if len(b) < 4 {
+				return nil, io.ErrUnexpectedEOF
+			}
+			v := uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
+			s := f.toUint32Slice()
+			*s = append(*s, v)
+			b = b[4:]
+		}
+		return res, nil
+	}
+	if w != WireFixed32 {
+		return b, errInternalBadWireType
+	}
+	if len(b) < 4 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
+	s := f.toUint32Slice()
+	*s = append(*s, v)
+	return b[4:], nil
+}
+
+func unmarshalFixedS32Value(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireFixed32 {
+		return b, errInternalBadWireType
+	}
+	if len(b) < 4 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := int32(b[0]) | int32(b[1])<<8 | int32(b[2])<<16 | int32(b[3])<<24
+	*f.toInt32() = v
+	return b[4:], nil
+}
+
+func unmarshalFixedS32Ptr(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireFixed32 {
+		return b, errInternalBadWireType
+	}
+	if len(b) < 4 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := int32(b[0]) | int32(b[1])<<8 | int32(b[2])<<16 | int32(b[3])<<24
+	f.setInt32Ptr(v)
+	return b[4:], nil
+}
+
+func unmarshalFixedS32Slice(b []byte, f pointer, w int) ([]byte, error) {
+	if w == WireBytes { // packed
+		x, n := decodeVarint(b)
+		if n == 0 {
+			return nil, io.ErrUnexpectedEOF
+		}
+		b = b[n:]
+		if x > uint64(len(b)) {
+			return nil, io.ErrUnexpectedEOF
+		}
+		res := b[x:]
+		b = b[:x]
+		for len(b) > 0 {
+			if len(b) < 4 {
+				return nil, io.ErrUnexpectedEOF
+			}
+			v := int32(b[0]) | int32(b[1])<<8 | int32(b[2])<<16 | int32(b[3])<<24
+			f.appendInt32Slice(v)
+			b = b[4:]
+		}
+		return res, nil
+	}
+	if w != WireFixed32 {
+		return b, errInternalBadWireType
+	}
+	if len(b) < 4 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := int32(b[0]) | int32(b[1])<<8 | int32(b[2])<<16 | int32(b[3])<<24
+	f.appendInt32Slice(v)
+	return b[4:], nil
+}
+
+func unmarshalBoolValue(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireVarint {
+		return b, errInternalBadWireType
+	}
+	// Note: any length varint is allowed, even though any sane
+	// encoder will use one byte.
+	// See https://github.com/golang/protobuf/issues/76
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	// TODO: check if x>1? Tests seem to indicate no.
+	v := x != 0
+	*f.toBool() = v
+	return b[n:], nil
+}
+
+func unmarshalBoolPtr(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireVarint {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := x != 0
+	*f.toBoolPtr() = &v
+	return b[n:], nil
+}
+
+func unmarshalBoolSlice(b []byte, f pointer, w int) ([]byte, error) {
+	if w == WireBytes { // packed
+		x, n := decodeVarint(b)
+		if n == 0 {
+			return nil, io.ErrUnexpectedEOF
+		}
+		b = b[n:]
+		if x > uint64(len(b)) {
+			return nil, io.ErrUnexpectedEOF
+		}
+		res := b[x:]
+		b = b[:x]
+		for len(b) > 0 {
+			x, n = decodeVarint(b)
+			if n == 0 {
+				return nil, io.ErrUnexpectedEOF
+			}
+			v := x != 0
+			s := f.toBoolSlice()
+			*s = append(*s, v)
+			b = b[n:]
+		}
+		return res, nil
+	}
+	if w != WireVarint {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := x != 0
+	s := f.toBoolSlice()
+	*s = append(*s, v)
+	return b[n:], nil
+}
+
+func unmarshalFloat64Value(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireFixed64 {
+		return b, errInternalBadWireType
+	}
+	if len(b) < 8 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := math.Float64frombits(uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56)
+	*f.toFloat64() = v
+	return b[8:], nil
+}
+
+func unmarshalFloat64Ptr(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireFixed64 {
+		return b, errInternalBadWireType
+	}
+	if len(b) < 8 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := math.Float64frombits(uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56)
+	*f.toFloat64Ptr() = &v
+	return b[8:], nil
+}
+
+func unmarshalFloat64Slice(b []byte, f pointer, w int) ([]byte, error) {
+	if w == WireBytes { // packed
+		x, n := decodeVarint(b)
+		if n == 0 {
+			return nil, io.ErrUnexpectedEOF
+		}
+		b = b[n:]
+		if x > uint64(len(b)) {
+			return nil, io.ErrUnexpectedEOF
+		}
+		res := b[x:]
+		b = b[:x]
+		for len(b) > 0 {
+			if len(b) < 8 {
+				return nil, io.ErrUnexpectedEOF
+			}
+			v := math.Float64frombits(uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56)
+			s := f.toFloat64Slice()
+			*s = append(*s, v)
+			b = b[8:]
+		}
+		return res, nil
+	}
+	if w != WireFixed64 {
+		return b, errInternalBadWireType
+	}
+	if len(b) < 8 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := math.Float64frombits(uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56)
+	s := f.toFloat64Slice()
+	*s = append(*s, v)
+	return b[8:], nil
+}
+
+func unmarshalFloat32Value(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireFixed32 {
+		return b, errInternalBadWireType
+	}
+	if len(b) < 4 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := math.Float32frombits(uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24)
+	*f.toFloat32() = v
+	return b[4:], nil
+}
+
+func unmarshalFloat32Ptr(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireFixed32 {
+		return b, errInternalBadWireType
+	}
+	if len(b) < 4 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := math.Float32frombits(uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24)
+	*f.toFloat32Ptr() = &v
+	return b[4:], nil
+}
+
+func unmarshalFloat32Slice(b []byte, f pointer, w int) ([]byte, error) {
+	if w == WireBytes { // packed
+		x, n := decodeVarint(b)
+		if n == 0 {
+			return nil, io.ErrUnexpectedEOF
+		}
+		b = b[n:]
+		if x > uint64(len(b)) {
+			return nil, io.ErrUnexpectedEOF
+		}
+		res := b[x:]
+		b = b[:x]
+		for len(b) > 0 {
+			if len(b) < 4 {
+				return nil, io.ErrUnexpectedEOF
+			}
+			v := math.Float32frombits(uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24)
+			s := f.toFloat32Slice()
+			*s = append(*s, v)
+			b = b[4:]
+		}
+		return res, nil
+	}
+	if w != WireFixed32 {
+		return b, errInternalBadWireType
+	}
+	if len(b) < 4 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := math.Float32frombits(uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24)
+	s := f.toFloat32Slice()
+	*s = append(*s, v)
+	return b[4:], nil
+}
+
+func unmarshalStringValue(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireBytes {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	if x > uint64(len(b)) {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := string(b[:x])
+	*f.toString() = v
+	return b[x:], nil
+}
+
+func unmarshalStringPtr(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireBytes {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	if x > uint64(len(b)) {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := string(b[:x])
+	*f.toStringPtr() = &v
+	return b[x:], nil
+}
+
+func unmarshalStringSlice(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireBytes {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	if x > uint64(len(b)) {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := string(b[:x])
+	s := f.toStringSlice()
+	*s = append(*s, v)
+	return b[x:], nil
+}
+
+func unmarshalUTF8StringValue(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireBytes {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	if x > uint64(len(b)) {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := string(b[:x])
+	*f.toString() = v
+	if !utf8.ValidString(v) {
+		return b[x:], errInvalidUTF8
+	}
+	return b[x:], nil
+}
+
+func unmarshalUTF8StringPtr(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireBytes {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	if x > uint64(len(b)) {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := string(b[:x])
+	*f.toStringPtr() = &v
+	if !utf8.ValidString(v) {
+		return b[x:], errInvalidUTF8
+	}
+	return b[x:], nil
+}
+
+func unmarshalUTF8StringSlice(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireBytes {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	if x > uint64(len(b)) {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := string(b[:x])
+	s := f.toStringSlice()
+	*s = append(*s, v)
+	if !utf8.ValidString(v) {
+		return b[x:], errInvalidUTF8
+	}
+	return b[x:], nil
+}
+
+var emptyBuf [0]byte
+
+func unmarshalBytesValue(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireBytes {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	if x > uint64(len(b)) {
+		return nil, io.ErrUnexpectedEOF
+	}
+	// The use of append here is a trick which avoids the zeroing
+	// that would be required if we used a make/copy pair.
+	// We append to emptyBuf instead of nil because we want
+	// a non-nil result even when the length is 0.
+	v := append(emptyBuf[:], b[:x]...)
+	*f.toBytes() = v
+	return b[x:], nil
+}
+
+func unmarshalBytesSlice(b []byte, f pointer, w int) ([]byte, error) {
+	if w != WireBytes {
+		return b, errInternalBadWireType
+	}
+	x, n := decodeVarint(b)
+	if n == 0 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	b = b[n:]
+	if x > uint64(len(b)) {
+		return nil, io.ErrUnexpectedEOF
+	}
+	v := append(emptyBuf[:], b[:x]...)
+	s := f.toBytesSlice()
+	*s = append(*s, v)
+	return b[x:], nil
+}
+
+func makeUnmarshalMessagePtr(sub *unmarshalInfo, name string) unmarshaler {
+	return func(b []byte, f pointer, w int) ([]byte, error) {
+		if w != WireBytes {
+			return b, errInternalBadWireType
+		}
+		x, n := decodeVarint(b)
+		if n == 0 {
+			return nil, io.ErrUnexpectedEOF
+		}
+		b = b[n:]
+		if x > uint64(len(b)) {
+			return nil, io.ErrUnexpectedEOF
+		}
+		// First read the message field to see if something is there.
+		// The semantics of multiple submessages are weird.  Instead of
+		// the last one winning (as it is for all other fields), multiple
+		// submessages are merged.
+		v := f.getPointer()
+		if v.isNil() {
+			v = valToPointer(reflect.New(sub.typ))
+			f.setPointer(v)
+		}
+		err := sub.unmarshal(v, b[:x])
+		if err != nil {
+			if r, ok := err.(*RequiredNotSetError); ok {
+				r.field = name + "." + r.field
+			} else {
+				return nil, err
+			}
+		}
+		return b[x:], err
+	}
+}
+
+func makeUnmarshalMessageSlicePtr(sub *unmarshalInfo, name string) unmarshaler {
+	return func(b []byte, f pointer, w int) ([]byte, error) {
+		if w != WireBytes {
+			return b, errInternalBadWireType
+		}
+		x, n := decodeVarint(b)
+		if n == 0 {
+			return nil, io.ErrUnexpectedEOF
+		}
+		b = b[n:]
+		if x > uint64(len(b)) {
+			return nil, io.ErrUnexpectedEOF
+		}
+		v := valToPointer(reflect.New(sub.typ))
+		err := sub.unmarshal(v, b[:x])
+		if err != nil {
+			if r, ok := err.(*RequiredNotSetError); ok {
+				r.field = name + "." + r.field
+			} else {
+				return nil, err
+			}
+		}
+		f.appendPointer(v)
+		return b[x:], err
+	}
+}
+
+func makeUnmarshalGroupPtr(sub *unmarshalInfo, name string) unmarshaler {
+	return func(b []byte, f pointer, w int) ([]byte, error) {
+		if w != WireStartGroup {
+			return b, errInternalBadWireType
+		}
+		x, y := findEndGroup(b)
+		if x < 0 {
+			return nil, io.ErrUnexpectedEOF
+		}
+		v := f.getPointer()
+		if v.isNil() {
+			v = valToPointer(reflect.New(sub.typ))
+			f.setPointer(v)
+		}
+		err := sub.unmarshal(v, b[:x])
+		if err != nil {
+			if r, ok := err.(*RequiredNotSetError); ok {
+				r.field = name + "." + r.field
+			} else {
+				return nil, err
+			}
+		}
+		return b[y:], err
+	}
+}
+
+func makeUnmarshalGroupSlicePtr(sub *unmarshalInfo, name string) unmarshaler {
+	return func(b []byte, f pointer, w int) ([]byte, error) {
+		if w != WireStartGroup {
+			return b, errInternalBadWireType
+		}
+		x, y := findEndGroup(b)
+		if x < 0 {
+			return nil, io.ErrUnexpectedEOF
+		}
+		v := valToPointer(reflect.New(sub.typ))
+		err := sub.unmarshal(v, b[:x])
+		if err != nil {
+			if r, ok := err.(*RequiredNotSetError); ok {
+				r.field = name + "." + r.field
+			} else {
+				return nil, err
+			}
+		}
+		f.appendPointer(v)
+		return b[y:], err
+	}
+}
+
+func makeUnmarshalMap(f *reflect.StructField) unmarshaler {
+	t := f.Type
+	kt := t.Key()
+	vt := t.Elem()
+	unmarshalKey := typeUnmarshaler(kt, f.Tag.Get("protobuf_key"))
+	unmarshalVal := typeUnmarshaler(vt, f.Tag.Get("protobuf_val"))
+	return func(b []byte, f pointer, w int) ([]byte, error) {
+		// The map entry is a submessage. Figure out how big it is.
+		if w != WireBytes {
+			return nil, fmt.Errorf("proto: bad wiretype for map field: got %d want %d", w, WireBytes)
+		}
+		x, n := decodeVarint(b)
+		if n == 0 {
+			return nil, io.ErrUnexpectedEOF
+		}
+		b = b[n:]
+		if x > uint64(len(b)) {
+			return nil, io.ErrUnexpectedEOF
+		}
+		r := b[x:] // unused data to return
+		b = b[:x]  // data for map entry
+
+		// Note: we could use #keys * #values ~= 200 functions
+		// to do map decoding without reflection. Probably not worth it.
+		// Maps will be somewhat slow. Oh well.
+
+		// Read key and value from data.
+		var nerr nonFatal
+		k := reflect.New(kt)
+		v := reflect.New(vt)
+		for len(b) > 0 {
+			x, n := decodeVarint(b)
+			if n == 0 {
+				return nil, io.ErrUnexpectedEOF
+			}
+			wire := int(x) & 7
+			b = b[n:]
+
+			var err error
+			switch x >> 3 {
+			case 1:
+				b, err = unmarshalKey(b, valToPointer(k), wire)
+			case 2:
+				b, err = unmarshalVal(b, valToPointer(v), wire)
+			default:
+				err = errInternalBadWireType // skip unknown tag
+			}
+
+			if nerr.Merge(err) {
+				continue
+			}
+			if err != errInternalBadWireType {
+				return nil, err
+			}
+
+			// Skip past unknown fields.
+			b, err = skipField(b, wire)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		// Get map, allocate if needed.
+		m := f.asPointerTo(t).Elem() // an addressable map[K]T
+		if m.IsNil() {
+			m.Set(reflect.MakeMap(t))
+		}
+
+		// Insert into map.
+		m.SetMapIndex(k.Elem(), v.Elem())
+
+		return r, nerr.E
+	}
+}
+
+// makeUnmarshalOneof makes an unmarshaler for oneof fields.
+// for:
+// message Msg {
+//   oneof F {
+//     int64 X = 1;
+//     float64 Y = 2;
+//   }
+// }
+// typ is the type of the concrete entry for a oneof case (e.g. Msg_X).
+// ityp is the interface type of the oneof field (e.g. isMsg_F).
+// unmarshal is the unmarshaler for the base type of the oneof case (e.g. int64).
+// Note that this function will be called once for each case in the oneof.
+func makeUnmarshalOneof(typ, ityp reflect.Type, unmarshal unmarshaler) unmarshaler {
+	sf := typ.Field(0)
+	field0 := toField(&sf)
+	return func(b []byte, f pointer, w int) ([]byte, error) {
+		// Allocate holder for value.
+		v := reflect.New(typ)
+
+		// Unmarshal data into holder.
+		// We unmarshal into the first field of the holder object.
+		var err error
+		var nerr nonFatal
+		b, err = unmarshal(b, valToPointer(v).offset(field0), w)
+		if !nerr.Merge(err) {
+			return nil, err
+		}
+
+		// Write pointer to holder into target field.
+		f.asPointerTo(ityp).Elem().Set(v)
+
+		return b, nerr.E
+	}
+}
+
+// Error used by decode internally.
+var errInternalBadWireType = errors.New("proto: internal error: bad wiretype")
+
+// skipField skips past a field of type wire and returns the remaining bytes.
+func skipField(b []byte, wire int) ([]byte, error) {
+	switch wire {
+	case WireVarint:
+		_, k := decodeVarint(b)
+		if k == 0 {
+			return b, io.ErrUnexpectedEOF
+		}
+		b = b[k:]
+	case WireFixed32:
+		if len(b) < 4 {
+			return b, io.ErrUnexpectedEOF
+		}
+		b = b[4:]
+	case WireFixed64:
+		if len(b) < 8 {
+			return b, io.ErrUnexpectedEOF
+		}
+		b = b[8:]
+	case WireBytes:
+		m, k := decodeVarint(b)
+		if k == 0 || uint64(len(b)-k) < m {
+			return b, io.ErrUnexpectedEOF
+		}
+		b = b[uint64(k)+m:]
+	case WireStartGroup:
+		_, i := findEndGroup(b)
+		if i == -1 {
+			return b, io.ErrUnexpectedEOF
+		}
+		b = b[i:]
+	default:
+		return b, fmt.Errorf("proto: can't skip unknown wire type %d", wire)
+	}
+	return b, nil
+}
+
+// findEndGroup finds the index of the next EndGroup tag.
+// Groups may be nested, so the "next" EndGroup tag is the first
+// unpaired EndGroup.
+// findEndGroup returns the indexes of the start and end of the EndGroup tag.
+// Returns (-1,-1) if it can't find one.
+func findEndGroup(b []byte) (int, int) {
+	depth := 1
+	i := 0
+	for {
+		x, n := decodeVarint(b[i:])
+		if n == 0 {
+			return -1, -1
+		}
+		j := i
+		i += n
+		switch x & 7 {
+		case WireVarint:
+			_, k := decodeVarint(b[i:])
+			if k == 0 {
+				return -1, -1
+			}
+			i += k
+		case WireFixed32:
+			if len(b)-4 < i {
+				return -1, -1
+			}
+			i += 4
+		case WireFixed64:
+			if len(b)-8 < i {
+				return -1, -1
+			}
+			i += 8
+		case WireBytes:
+			m, k := decodeVarint(b[i:])
+			if k == 0 {
+				return -1, -1
+			}
+			i += k
+			if uint64(len(b)-i) < m {
+				return -1, -1
+			}
+			i += int(m)
+		case WireStartGroup:
+			depth++
+		case WireEndGroup:
+			depth--
+			if depth == 0 {
+				return j, i
+			}
+		default:
+			return -1, -1
+		}
+	}
+}
+
+// encodeVarint appends a varint-encoded integer to b and returns the result.
+func encodeVarint(b []byte, x uint64) []byte {
+	for x >= 1<<7 {
+		b = append(b, byte(x&0x7f|0x80))
+		x >>= 7
+	}
+	return append(b, byte(x))
+}
+
+// decodeVarint reads a varint-encoded integer from b.
+// Returns the decoded integer and the number of bytes read.
+// If there is an error, it returns 0,0.
+func decodeVarint(b []byte) (uint64, int) {
+	var x, y uint64
+	if len(b) <= 0 {
+		goto bad
+	}
+	x = uint64(b[0])
+	if x < 0x80 {
+		return x, 1
+	}
+	x -= 0x80
+
+	if len(b) <= 1 {
+		goto bad
+	}
+	y = uint64(b[1])
+	x += y << 7
+	if y < 0x80 {
+		return x, 2
+	}
+	x -= 0x80 << 7
+
+	if len(b) <= 2 {
+		goto bad
+	}
+	y = uint64(b[2])
+	x += y << 14
+	if y < 0x80 {
+		return x, 3
+	}
+	x -= 0x80 << 14
+
+	if len(b) <= 3 {
+		goto bad
+	}
+	y = uint64(b[3])
+	x += y << 21
+	if y < 0x80 {
+		return x, 4
+	}
+	x -= 0x80 << 21
+
+	if len(b) <= 4 {
+		goto bad
+	}
+	y = uint64(b[4])
+	x += y << 28
+	if y < 0x80 {
+		return x, 5
+	}
+	x -= 0x80 << 28
+
+	if len(b) <= 5 {
+		goto bad
+	}
+	y = uint64(b[5])
+	x += y << 35
+	if y < 0x80 {
+		return x, 6
+	}
+	x -= 0x80 << 35
+
+	if len(b) <= 6 {
+		goto bad
+	}
+	y = uint64(b[6])
+	x += y << 42
+	if y < 0x80 {
+		return x, 7
+	}
+	x -= 0x80 << 42
+
+	if len(b) <= 7 {
+		goto bad
+	}
+	y = uint64(b[7])
+	x += y << 49
+	if y < 0x80 {
+		return x, 8
+	}
+	x -= 0x80 << 49
+
+	if len(b) <= 8 {
+		goto bad
+	}
+	y = uint64(b[8])
+	x += y << 56
+	if y < 0x80 {
+		return x, 9
+	}
+	x -= 0x80 << 56
+
+	if len(b) <= 9 {
+		goto bad
+	}
+	y = uint64(b[9])
+	x += y << 63
+	if y < 2 {
+		return x, 10
+	}
+
+bad:
+	return 0, 0
+}
diff --git a/vendor/github.com/golang/protobuf/proto/text.go b/vendor/github.com/golang/protobuf/proto/text.go
new file mode 100644
index 0000000..1aaee72
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/text.go
@@ -0,0 +1,843 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2010 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package proto
+
+// Functions for writing the text protocol buffer format.
+
+import (
+	"bufio"
+	"bytes"
+	"encoding"
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"math"
+	"reflect"
+	"sort"
+	"strings"
+)
+
+var (
+	newline         = []byte("\n")
+	spaces          = []byte("                                        ")
+	endBraceNewline = []byte("}\n")
+	backslashN      = []byte{'\\', 'n'}
+	backslashR      = []byte{'\\', 'r'}
+	backslashT      = []byte{'\\', 't'}
+	backslashDQ     = []byte{'\\', '"'}
+	backslashBS     = []byte{'\\', '\\'}
+	posInf          = []byte("inf")
+	negInf          = []byte("-inf")
+	nan             = []byte("nan")
+)
+
+type writer interface {
+	io.Writer
+	WriteByte(byte) error
+}
+
+// textWriter is an io.Writer that tracks its indentation level.
+type textWriter struct {
+	ind      int
+	complete bool // if the current position is a complete line
+	compact  bool // whether to write out as a one-liner
+	w        writer
+}
+
+func (w *textWriter) WriteString(s string) (n int, err error) {
+	if !strings.Contains(s, "\n") {
+		if !w.compact && w.complete {
+			w.writeIndent()
+		}
+		w.complete = false
+		return io.WriteString(w.w, s)
+	}
+	// WriteString is typically called without newlines, so this
+	// codepath and its copy are rare.  We copy to avoid
+	// duplicating all of Write's logic here.
+	return w.Write([]byte(s))
+}
+
+func (w *textWriter) Write(p []byte) (n int, err error) {
+	newlines := bytes.Count(p, newline)
+	if newlines == 0 {
+		if !w.compact && w.complete {
+			w.writeIndent()
+		}
+		n, err = w.w.Write(p)
+		w.complete = false
+		return n, err
+	}
+
+	frags := bytes.SplitN(p, newline, newlines+1)
+	if w.compact {
+		for i, frag := range frags {
+			if i > 0 {
+				if err := w.w.WriteByte(' '); err != nil {
+					return n, err
+				}
+				n++
+			}
+			nn, err := w.w.Write(frag)
+			n += nn
+			if err != nil {
+				return n, err
+			}
+		}
+		return n, nil
+	}
+
+	for i, frag := range frags {
+		if w.complete {
+			w.writeIndent()
+		}
+		nn, err := w.w.Write(frag)
+		n += nn
+		if err != nil {
+			return n, err
+		}
+		if i+1 < len(frags) {
+			if err := w.w.WriteByte('\n'); err != nil {
+				return n, err
+			}
+			n++
+		}
+	}
+	w.complete = len(frags[len(frags)-1]) == 0
+	return n, nil
+}
+
+func (w *textWriter) WriteByte(c byte) error {
+	if w.compact && c == '\n' {
+		c = ' '
+	}
+	if !w.compact && w.complete {
+		w.writeIndent()
+	}
+	err := w.w.WriteByte(c)
+	w.complete = c == '\n'
+	return err
+}
+
+func (w *textWriter) indent() { w.ind++ }
+
+func (w *textWriter) unindent() {
+	if w.ind == 0 {
+		log.Print("proto: textWriter unindented too far")
+		return
+	}
+	w.ind--
+}
+
+func writeName(w *textWriter, props *Properties) error {
+	if _, err := w.WriteString(props.OrigName); err != nil {
+		return err
+	}
+	if props.Wire != "group" {
+		return w.WriteByte(':')
+	}
+	return nil
+}
+
+func requiresQuotes(u string) bool {
+	// When type URL contains any characters except [0-9A-Za-z./\-]*, it must be quoted.
+	for _, ch := range u {
+		switch {
+		case ch == '.' || ch == '/' || ch == '_':
+			continue
+		case '0' <= ch && ch <= '9':
+			continue
+		case 'A' <= ch && ch <= 'Z':
+			continue
+		case 'a' <= ch && ch <= 'z':
+			continue
+		default:
+			return true
+		}
+	}
+	return false
+}
+
+// isAny reports whether sv is a google.protobuf.Any message
+func isAny(sv reflect.Value) bool {
+	type wkt interface {
+		XXX_WellKnownType() string
+	}
+	t, ok := sv.Addr().Interface().(wkt)
+	return ok && t.XXX_WellKnownType() == "Any"
+}
+
+// writeProto3Any writes an expanded google.protobuf.Any message.
+//
+// It returns (false, nil) if sv value can't be unmarshaled (e.g. because
+// required messages are not linked in).
+//
+// It returns (true, error) when sv was written in expanded format or an error
+// was encountered.
+func (tm *TextMarshaler) writeProto3Any(w *textWriter, sv reflect.Value) (bool, error) {
+	turl := sv.FieldByName("TypeUrl")
+	val := sv.FieldByName("Value")
+	if !turl.IsValid() || !val.IsValid() {
+		return true, errors.New("proto: invalid google.protobuf.Any message")
+	}
+
+	b, ok := val.Interface().([]byte)
+	if !ok {
+		return true, errors.New("proto: invalid google.protobuf.Any message")
+	}
+
+	parts := strings.Split(turl.String(), "/")
+	mt := MessageType(parts[len(parts)-1])
+	if mt == nil {
+		return false, nil
+	}
+	m := reflect.New(mt.Elem())
+	if err := Unmarshal(b, m.Interface().(Message)); err != nil {
+		return false, nil
+	}
+	w.Write([]byte("["))
+	u := turl.String()
+	if requiresQuotes(u) {
+		writeString(w, u)
+	} else {
+		w.Write([]byte(u))
+	}
+	if w.compact {
+		w.Write([]byte("]:<"))
+	} else {
+		w.Write([]byte("]: <\n"))
+		w.ind++
+	}
+	if err := tm.writeStruct(w, m.Elem()); err != nil {
+		return true, err
+	}
+	if w.compact {
+		w.Write([]byte("> "))
+	} else {
+		w.ind--
+		w.Write([]byte(">\n"))
+	}
+	return true, nil
+}
+
+func (tm *TextMarshaler) writeStruct(w *textWriter, sv reflect.Value) error {
+	if tm.ExpandAny && isAny(sv) {
+		if canExpand, err := tm.writeProto3Any(w, sv); canExpand {
+			return err
+		}
+	}
+	st := sv.Type()
+	sprops := GetProperties(st)
+	for i := 0; i < sv.NumField(); i++ {
+		fv := sv.Field(i)
+		props := sprops.Prop[i]
+		name := st.Field(i).Name
+
+		if name == "XXX_NoUnkeyedLiteral" {
+			continue
+		}
+
+		if strings.HasPrefix(name, "XXX_") {
+			// There are two XXX_ fields:
+			//   XXX_unrecognized []byte
+			//   XXX_extensions   map[int32]proto.Extension
+			// The first is handled here;
+			// the second is handled at the bottom of this function.
+			if name == "XXX_unrecognized" && !fv.IsNil() {
+				if err := writeUnknownStruct(w, fv.Interface().([]byte)); err != nil {
+					return err
+				}
+			}
+			continue
+		}
+		if fv.Kind() == reflect.Ptr && fv.IsNil() {
+			// Field not filled in. This could be an optional field or
+			// a required field that wasn't filled in. Either way, there
+			// isn't anything we can show for it.
+			continue
+		}
+		if fv.Kind() == reflect.Slice && fv.IsNil() {
+			// Repeated field that is empty, or a bytes field that is unused.
+			continue
+		}
+
+		if props.Repeated && fv.Kind() == reflect.Slice {
+			// Repeated field.
+			for j := 0; j < fv.Len(); j++ {
+				if err := writeName(w, props); err != nil {
+					return err
+				}
+				if !w.compact {
+					if err := w.WriteByte(' '); err != nil {
+						return err
+					}
+				}
+				v := fv.Index(j)
+				if v.Kind() == reflect.Ptr && v.IsNil() {
+					// A nil message in a repeated field is not valid,
+					// but we can handle that more gracefully than panicking.
+					if _, err := w.Write([]byte("<nil>\n")); err != nil {
+						return err
+					}
+					continue
+				}
+				if err := tm.writeAny(w, v, props); err != nil {
+					return err
+				}
+				if err := w.WriteByte('\n'); err != nil {
+					return err
+				}
+			}
+			continue
+		}
+		if fv.Kind() == reflect.Map {
+			// Map fields are rendered as a repeated struct with key/value fields.
+			keys := fv.MapKeys()
+			sort.Sort(mapKeys(keys))
+			for _, key := range keys {
+				val := fv.MapIndex(key)
+				if err := writeName(w, props); err != nil {
+					return err
+				}
+				if !w.compact {
+					if err := w.WriteByte(' '); err != nil {
+						return err
+					}
+				}
+				// open struct
+				if err := w.WriteByte('<'); err != nil {
+					return err
+				}
+				if !w.compact {
+					if err := w.WriteByte('\n'); err != nil {
+						return err
+					}
+				}
+				w.indent()
+				// key
+				if _, err := w.WriteString("key:"); err != nil {
+					return err
+				}
+				if !w.compact {
+					if err := w.WriteByte(' '); err != nil {
+						return err
+					}
+				}
+				if err := tm.writeAny(w, key, props.MapKeyProp); err != nil {
+					return err
+				}
+				if err := w.WriteByte('\n'); err != nil {
+					return err
+				}
+				// nil values aren't legal, but we can avoid panicking because of them.
+				if val.Kind() != reflect.Ptr || !val.IsNil() {
+					// value
+					if _, err := w.WriteString("value:"); err != nil {
+						return err
+					}
+					if !w.compact {
+						if err := w.WriteByte(' '); err != nil {
+							return err
+						}
+					}
+					if err := tm.writeAny(w, val, props.MapValProp); err != nil {
+						return err
+					}
+					if err := w.WriteByte('\n'); err != nil {
+						return err
+					}
+				}
+				// close struct
+				w.unindent()
+				if err := w.WriteByte('>'); err != nil {
+					return err
+				}
+				if err := w.WriteByte('\n'); err != nil {
+					return err
+				}
+			}
+			continue
+		}
+		if props.proto3 && fv.Kind() == reflect.Slice && fv.Len() == 0 {
+			// empty bytes field
+			continue
+		}
+		if fv.Kind() != reflect.Ptr && fv.Kind() != reflect.Slice {
+			// proto3 non-repeated scalar field; skip if zero value
+			if isProto3Zero(fv) {
+				continue
+			}
+		}
+
+		if fv.Kind() == reflect.Interface {
+			// Check if it is a oneof.
+			if st.Field(i).Tag.Get("protobuf_oneof") != "" {
+				// fv is nil, or holds a pointer to generated struct.
+				// That generated struct has exactly one field,
+				// which has a protobuf struct tag.
+				if fv.IsNil() {
+					continue
+				}
+				inner := fv.Elem().Elem() // interface -> *T -> T
+				tag := inner.Type().Field(0).Tag.Get("protobuf")
+				props = new(Properties) // Overwrite the outer props var, but not its pointee.
+				props.Parse(tag)
+				// Write the value in the oneof, not the oneof itself.
+				fv = inner.Field(0)
+
+				// Special case to cope with malformed messages gracefully:
+				// If the value in the oneof is a nil pointer, don't panic
+				// in writeAny.
+				if fv.Kind() == reflect.Ptr && fv.IsNil() {
+					// Use errors.New so writeAny won't render quotes.
+					msg := errors.New("/* nil */")
+					fv = reflect.ValueOf(&msg).Elem()
+				}
+			}
+		}
+
+		if err := writeName(w, props); err != nil {
+			return err
+		}
+		if !w.compact {
+			if err := w.WriteByte(' '); err != nil {
+				return err
+			}
+		}
+
+		// Enums have a String method, so writeAny will work fine.
+		if err := tm.writeAny(w, fv, props); err != nil {
+			return err
+		}
+
+		if err := w.WriteByte('\n'); err != nil {
+			return err
+		}
+	}
+
+	// Extensions (the XXX_extensions field).
+	pv := sv.Addr()
+	if _, err := extendable(pv.Interface()); err == nil {
+		if err := tm.writeExtensions(w, pv); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// writeAny writes an arbitrary field.
+func (tm *TextMarshaler) writeAny(w *textWriter, v reflect.Value, props *Properties) error {
+	v = reflect.Indirect(v)
+
+	// Floats have special cases.
+	if v.Kind() == reflect.Float32 || v.Kind() == reflect.Float64 {
+		x := v.Float()
+		var b []byte
+		switch {
+		case math.IsInf(x, 1):
+			b = posInf
+		case math.IsInf(x, -1):
+			b = negInf
+		case math.IsNaN(x):
+			b = nan
+		}
+		if b != nil {
+			_, err := w.Write(b)
+			return err
+		}
+		// Other values are handled below.
+	}
+
+	// We don't attempt to serialise every possible value type; only those
+	// that can occur in protocol buffers.
+	switch v.Kind() {
+	case reflect.Slice:
+		// Should only be a []byte; repeated fields are handled in writeStruct.
+		if err := writeString(w, string(v.Bytes())); err != nil {
+			return err
+		}
+	case reflect.String:
+		if err := writeString(w, v.String()); err != nil {
+			return err
+		}
+	case reflect.Struct:
+		// Required/optional group/message.
+		var bra, ket byte = '<', '>'
+		if props != nil && props.Wire == "group" {
+			bra, ket = '{', '}'
+		}
+		if err := w.WriteByte(bra); err != nil {
+			return err
+		}
+		if !w.compact {
+			if err := w.WriteByte('\n'); err != nil {
+				return err
+			}
+		}
+		w.indent()
+		if v.CanAddr() {
+			// Calling v.Interface on a struct causes the reflect package to
+			// copy the entire struct. This is racy with the new Marshaler
+			// since we atomically update the XXX_sizecache.
+			//
+			// Thus, we retrieve a pointer to the struct if possible to avoid
+			// a race since v.Interface on the pointer doesn't copy the struct.
+			//
+			// If v is not addressable, then we are not worried about a race
+			// since it implies that the binary Marshaler cannot possibly be
+			// mutating this value.
+			v = v.Addr()
+		}
+		if etm, ok := v.Interface().(encoding.TextMarshaler); ok {
+			text, err := etm.MarshalText()
+			if err != nil {
+				return err
+			}
+			if _, err = w.Write(text); err != nil {
+				return err
+			}
+		} else {
+			if v.Kind() == reflect.Ptr {
+				v = v.Elem()
+			}
+			if err := tm.writeStruct(w, v); err != nil {
+				return err
+			}
+		}
+		w.unindent()
+		if err := w.WriteByte(ket); err != nil {
+			return err
+		}
+	default:
+		_, err := fmt.Fprint(w, v.Interface())
+		return err
+	}
+	return nil
+}
+
+// equivalent to C's isprint.
+func isprint(c byte) bool {
+	return c >= 0x20 && c < 0x7f
+}
+
+// writeString writes a string in the protocol buffer text format.
+// It is similar to strconv.Quote except we don't use Go escape sequences,
+// we treat the string as a byte sequence, and we use octal escapes.
+// These differences are to maintain interoperability with the other
+// languages' implementations of the text format.
+func writeString(w *textWriter, s string) error {
+	// use WriteByte here to get any needed indent
+	if err := w.WriteByte('"'); err != nil {
+		return err
+	}
+	// Loop over the bytes, not the runes.
+	for i := 0; i < len(s); i++ {
+		var err error
+		// Divergence from C++: we don't escape apostrophes.
+		// There's no need to escape them, and the C++ parser
+		// copes with a naked apostrophe.
+		switch c := s[i]; c {
+		case '\n':
+			_, err = w.w.Write(backslashN)
+		case '\r':
+			_, err = w.w.Write(backslashR)
+		case '\t':
+			_, err = w.w.Write(backslashT)
+		case '"':
+			_, err = w.w.Write(backslashDQ)
+		case '\\':
+			_, err = w.w.Write(backslashBS)
+		default:
+			if isprint(c) {
+				err = w.w.WriteByte(c)
+			} else {
+				_, err = fmt.Fprintf(w.w, "\\%03o", c)
+			}
+		}
+		if err != nil {
+			return err
+		}
+	}
+	return w.WriteByte('"')
+}
+
+func writeUnknownStruct(w *textWriter, data []byte) (err error) {
+	if !w.compact {
+		if _, err := fmt.Fprintf(w, "/* %d unknown bytes */\n", len(data)); err != nil {
+			return err
+		}
+	}
+	b := NewBuffer(data)
+	for b.index < len(b.buf) {
+		x, err := b.DecodeVarint()
+		if err != nil {
+			_, err := fmt.Fprintf(w, "/* %v */\n", err)
+			return err
+		}
+		wire, tag := x&7, x>>3
+		if wire == WireEndGroup {
+			w.unindent()
+			if _, err := w.Write(endBraceNewline); err != nil {
+				return err
+			}
+			continue
+		}
+		if _, err := fmt.Fprint(w, tag); err != nil {
+			return err
+		}
+		if wire != WireStartGroup {
+			if err := w.WriteByte(':'); err != nil {
+				return err
+			}
+		}
+		if !w.compact || wire == WireStartGroup {
+			if err := w.WriteByte(' '); err != nil {
+				return err
+			}
+		}
+		switch wire {
+		case WireBytes:
+			buf, e := b.DecodeRawBytes(false)
+			if e == nil {
+				_, err = fmt.Fprintf(w, "%q", buf)
+			} else {
+				_, err = fmt.Fprintf(w, "/* %v */", e)
+			}
+		case WireFixed32:
+			x, err = b.DecodeFixed32()
+			err = writeUnknownInt(w, x, err)
+		case WireFixed64:
+			x, err = b.DecodeFixed64()
+			err = writeUnknownInt(w, x, err)
+		case WireStartGroup:
+			err = w.WriteByte('{')
+			w.indent()
+		case WireVarint:
+			x, err = b.DecodeVarint()
+			err = writeUnknownInt(w, x, err)
+		default:
+			_, err = fmt.Fprintf(w, "/* unknown wire type %d */", wire)
+		}
+		if err != nil {
+			return err
+		}
+		if err = w.WriteByte('\n'); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func writeUnknownInt(w *textWriter, x uint64, err error) error {
+	if err == nil {
+		_, err = fmt.Fprint(w, x)
+	} else {
+		_, err = fmt.Fprintf(w, "/* %v */", err)
+	}
+	return err
+}
+
+type int32Slice []int32
+
+func (s int32Slice) Len() int           { return len(s) }
+func (s int32Slice) Less(i, j int) bool { return s[i] < s[j] }
+func (s int32Slice) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+
+// writeExtensions writes all the extensions in pv.
+// pv is assumed to be a pointer to a protocol message struct that is extendable.
+func (tm *TextMarshaler) writeExtensions(w *textWriter, pv reflect.Value) error {
+	emap := extensionMaps[pv.Type().Elem()]
+	ep, _ := extendable(pv.Interface())
+
+	// Order the extensions by ID.
+	// This isn't strictly necessary, but it will give us
+	// canonical output, which will also make testing easier.
+	m, mu := ep.extensionsRead()
+	if m == nil {
+		return nil
+	}
+	mu.Lock()
+	ids := make([]int32, 0, len(m))
+	for id := range m {
+		ids = append(ids, id)
+	}
+	sort.Sort(int32Slice(ids))
+	mu.Unlock()
+
+	for _, extNum := range ids {
+		ext := m[extNum]
+		var desc *ExtensionDesc
+		if emap != nil {
+			desc = emap[extNum]
+		}
+		if desc == nil {
+			// Unknown extension.
+			if err := writeUnknownStruct(w, ext.enc); err != nil {
+				return err
+			}
+			continue
+		}
+
+		pb, err := GetExtension(ep, desc)
+		if err != nil {
+			return fmt.Errorf("failed getting extension: %v", err)
+		}
+
+		// Repeated extensions will appear as a slice.
+		if !desc.repeated() {
+			if err := tm.writeExtension(w, desc.Name, pb); err != nil {
+				return err
+			}
+		} else {
+			v := reflect.ValueOf(pb)
+			for i := 0; i < v.Len(); i++ {
+				if err := tm.writeExtension(w, desc.Name, v.Index(i).Interface()); err != nil {
+					return err
+				}
+			}
+		}
+	}
+	return nil
+}
+
+func (tm *TextMarshaler) writeExtension(w *textWriter, name string, pb interface{}) error {
+	if _, err := fmt.Fprintf(w, "[%s]:", name); err != nil {
+		return err
+	}
+	if !w.compact {
+		if err := w.WriteByte(' '); err != nil {
+			return err
+		}
+	}
+	if err := tm.writeAny(w, reflect.ValueOf(pb), nil); err != nil {
+		return err
+	}
+	if err := w.WriteByte('\n'); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (w *textWriter) writeIndent() {
+	if !w.complete {
+		return
+	}
+	remain := w.ind * 2
+	for remain > 0 {
+		n := remain
+		if n > len(spaces) {
+			n = len(spaces)
+		}
+		w.w.Write(spaces[:n])
+		remain -= n
+	}
+	w.complete = false
+}
+
+// TextMarshaler is a configurable text format marshaler.
+type TextMarshaler struct {
+	Compact   bool // use compact text format (one line).
+	ExpandAny bool // expand google.protobuf.Any messages of known types
+}
+
+// Marshal writes a given protocol buffer in text format.
+// The only errors returned are from w.
+func (tm *TextMarshaler) Marshal(w io.Writer, pb Message) error {
+	val := reflect.ValueOf(pb)
+	if pb == nil || val.IsNil() {
+		w.Write([]byte("<nil>"))
+		return nil
+	}
+	var bw *bufio.Writer
+	ww, ok := w.(writer)
+	if !ok {
+		bw = bufio.NewWriter(w)
+		ww = bw
+	}
+	aw := &textWriter{
+		w:        ww,
+		complete: true,
+		compact:  tm.Compact,
+	}
+
+	if etm, ok := pb.(encoding.TextMarshaler); ok {
+		text, err := etm.MarshalText()
+		if err != nil {
+			return err
+		}
+		if _, err = aw.Write(text); err != nil {
+			return err
+		}
+		if bw != nil {
+			return bw.Flush()
+		}
+		return nil
+	}
+	// Dereference the received pointer so we don't have outer < and >.
+	v := reflect.Indirect(val)
+	if err := tm.writeStruct(aw, v); err != nil {
+		return err
+	}
+	if bw != nil {
+		return bw.Flush()
+	}
+	return nil
+}
+
+// Text is the same as Marshal, but returns the string directly.
+func (tm *TextMarshaler) Text(pb Message) string {
+	var buf bytes.Buffer
+	tm.Marshal(&buf, pb)
+	return buf.String()
+}
+
+var (
+	defaultTextMarshaler = TextMarshaler{}
+	compactTextMarshaler = TextMarshaler{Compact: true}
+)
+
+// TODO: consider removing some of the Marshal functions below.
+
+// MarshalText writes a given protocol buffer in text format.
+// The only errors returned are from w.
+func MarshalText(w io.Writer, pb Message) error { return defaultTextMarshaler.Marshal(w, pb) }
+
+// MarshalTextString is the same as MarshalText, but returns the string directly.
+func MarshalTextString(pb Message) string { return defaultTextMarshaler.Text(pb) }
+
+// CompactText writes a given protocol buffer in compact text format (one line).
+func CompactText(w io.Writer, pb Message) error { return compactTextMarshaler.Marshal(w, pb) }
+
+// CompactTextString is the same as CompactText, but returns the string directly.
+func CompactTextString(pb Message) string { return compactTextMarshaler.Text(pb) }
diff --git a/vendor/github.com/golang/protobuf/proto/text_parser.go b/vendor/github.com/golang/protobuf/proto/text_parser.go
new file mode 100644
index 0000000..bb55a3a
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/text_parser.go
@@ -0,0 +1,880 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2010 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package proto
+
+// Functions for parsing the Text protocol buffer format.
+// TODO: message sets.
+
+import (
+	"encoding"
+	"errors"
+	"fmt"
+	"reflect"
+	"strconv"
+	"strings"
+	"unicode/utf8"
+)
+
+// Error string emitted when deserializing Any and fields are already set
+const anyRepeatedlyUnpacked = "Any message unpacked multiple times, or %q already set"
+
+type ParseError struct {
+	Message string
+	Line    int // 1-based line number
+	Offset  int // 0-based byte offset from start of input
+}
+
+func (p *ParseError) Error() string {
+	if p.Line == 1 {
+		// show offset only for first line
+		return fmt.Sprintf("line 1.%d: %v", p.Offset, p.Message)
+	}
+	return fmt.Sprintf("line %d: %v", p.Line, p.Message)
+}
+
+type token struct {
+	value    string
+	err      *ParseError
+	line     int    // line number
+	offset   int    // byte number from start of input, not start of line
+	unquoted string // the unquoted version of value, if it was a quoted string
+}
+
+func (t *token) String() string {
+	if t.err == nil {
+		return fmt.Sprintf("%q (line=%d, offset=%d)", t.value, t.line, t.offset)
+	}
+	return fmt.Sprintf("parse error: %v", t.err)
+}
+
+type textParser struct {
+	s            string // remaining input
+	done         bool   // whether the parsing is finished (success or error)
+	backed       bool   // whether back() was called
+	offset, line int
+	cur          token
+}
+
+func newTextParser(s string) *textParser {
+	p := new(textParser)
+	p.s = s
+	p.line = 1
+	p.cur.line = 1
+	return p
+}
+
+func (p *textParser) errorf(format string, a ...interface{}) *ParseError {
+	pe := &ParseError{fmt.Sprintf(format, a...), p.cur.line, p.cur.offset}
+	p.cur.err = pe
+	p.done = true
+	return pe
+}
+
+// Numbers and identifiers are matched by [-+._A-Za-z0-9]
+func isIdentOrNumberChar(c byte) bool {
+	switch {
+	case 'A' <= c && c <= 'Z', 'a' <= c && c <= 'z':
+		return true
+	case '0' <= c && c <= '9':
+		return true
+	}
+	switch c {
+	case '-', '+', '.', '_':
+		return true
+	}
+	return false
+}
+
+func isWhitespace(c byte) bool {
+	switch c {
+	case ' ', '\t', '\n', '\r':
+		return true
+	}
+	return false
+}
+
+func isQuote(c byte) bool {
+	switch c {
+	case '"', '\'':
+		return true
+	}
+	return false
+}
+
+func (p *textParser) skipWhitespace() {
+	i := 0
+	for i < len(p.s) && (isWhitespace(p.s[i]) || p.s[i] == '#') {
+		if p.s[i] == '#' {
+			// comment; skip to end of line or input
+			for i < len(p.s) && p.s[i] != '\n' {
+				i++
+			}
+			if i == len(p.s) {
+				break
+			}
+		}
+		if p.s[i] == '\n' {
+			p.line++
+		}
+		i++
+	}
+	p.offset += i
+	p.s = p.s[i:len(p.s)]
+	if len(p.s) == 0 {
+		p.done = true
+	}
+}
+
+func (p *textParser) advance() {
+	// Skip whitespace
+	p.skipWhitespace()
+	if p.done {
+		return
+	}
+
+	// Start of non-whitespace
+	p.cur.err = nil
+	p.cur.offset, p.cur.line = p.offset, p.line
+	p.cur.unquoted = ""
+	switch p.s[0] {
+	case '<', '>', '{', '}', ':', '[', ']', ';', ',', '/':
+		// Single symbol
+		p.cur.value, p.s = p.s[0:1], p.s[1:len(p.s)]
+	case '"', '\'':
+		// Quoted string
+		i := 1
+		for i < len(p.s) && p.s[i] != p.s[0] && p.s[i] != '\n' {
+			if p.s[i] == '\\' && i+1 < len(p.s) {
+				// skip escaped char
+				i++
+			}
+			i++
+		}
+		if i >= len(p.s) || p.s[i] != p.s[0] {
+			p.errorf("unmatched quote")
+			return
+		}
+		unq, err := unquoteC(p.s[1:i], rune(p.s[0]))
+		if err != nil {
+			p.errorf("invalid quoted string %s: %v", p.s[0:i+1], err)
+			return
+		}
+		p.cur.value, p.s = p.s[0:i+1], p.s[i+1:len(p.s)]
+		p.cur.unquoted = unq
+	default:
+		i := 0
+		for i < len(p.s) && isIdentOrNumberChar(p.s[i]) {
+			i++
+		}
+		if i == 0 {
+			p.errorf("unexpected byte %#x", p.s[0])
+			return
+		}
+		p.cur.value, p.s = p.s[0:i], p.s[i:len(p.s)]
+	}
+	p.offset += len(p.cur.value)
+}
+
+var (
+	errBadUTF8 = errors.New("proto: bad UTF-8")
+)
+
+func unquoteC(s string, quote rune) (string, error) {
+	// This is based on C++'s tokenizer.cc.
+	// Despite its name, this is *not* parsing C syntax.
+	// For instance, "\0" is an invalid quoted string.
+
+	// Avoid allocation in trivial cases.
+	simple := true
+	for _, r := range s {
+		if r == '\\' || r == quote {
+			simple = false
+			break
+		}
+	}
+	if simple {
+		return s, nil
+	}
+
+	buf := make([]byte, 0, 3*len(s)/2)
+	for len(s) > 0 {
+		r, n := utf8.DecodeRuneInString(s)
+		if r == utf8.RuneError && n == 1 {
+			return "", errBadUTF8
+		}
+		s = s[n:]
+		if r != '\\' {
+			if r < utf8.RuneSelf {
+				buf = append(buf, byte(r))
+			} else {
+				buf = append(buf, string(r)...)
+			}
+			continue
+		}
+
+		ch, tail, err := unescape(s)
+		if err != nil {
+			return "", err
+		}
+		buf = append(buf, ch...)
+		s = tail
+	}
+	return string(buf), nil
+}
+
+func unescape(s string) (ch string, tail string, err error) {
+	r, n := utf8.DecodeRuneInString(s)
+	if r == utf8.RuneError && n == 1 {
+		return "", "", errBadUTF8
+	}
+	s = s[n:]
+	switch r {
+	case 'a':
+		return "\a", s, nil
+	case 'b':
+		return "\b", s, nil
+	case 'f':
+		return "\f", s, nil
+	case 'n':
+		return "\n", s, nil
+	case 'r':
+		return "\r", s, nil
+	case 't':
+		return "\t", s, nil
+	case 'v':
+		return "\v", s, nil
+	case '?':
+		return "?", s, nil // trigraph workaround
+	case '\'', '"', '\\':
+		return string(r), s, nil
+	case '0', '1', '2', '3', '4', '5', '6', '7':
+		if len(s) < 2 {
+			return "", "", fmt.Errorf(`\%c requires 2 following digits`, r)
+		}
+		ss := string(r) + s[:2]
+		s = s[2:]
+		i, err := strconv.ParseUint(ss, 8, 8)
+		if err != nil {
+			return "", "", fmt.Errorf(`\%s contains non-octal digits`, ss)
+		}
+		return string([]byte{byte(i)}), s, nil
+	case 'x', 'X', 'u', 'U':
+		var n int
+		switch r {
+		case 'x', 'X':
+			n = 2
+		case 'u':
+			n = 4
+		case 'U':
+			n = 8
+		}
+		if len(s) < n {
+			return "", "", fmt.Errorf(`\%c requires %d following digits`, r, n)
+		}
+		ss := s[:n]
+		s = s[n:]
+		i, err := strconv.ParseUint(ss, 16, 64)
+		if err != nil {
+			return "", "", fmt.Errorf(`\%c%s contains non-hexadecimal digits`, r, ss)
+		}
+		if r == 'x' || r == 'X' {
+			return string([]byte{byte(i)}), s, nil
+		}
+		if i > utf8.MaxRune {
+			return "", "", fmt.Errorf(`\%c%s is not a valid Unicode code point`, r, ss)
+		}
+		return string(i), s, nil
+	}
+	return "", "", fmt.Errorf(`unknown escape \%c`, r)
+}
+
+// Back off the parser by one token. Can only be done between calls to next().
+// It makes the next advance() a no-op.
+func (p *textParser) back() { p.backed = true }
+
+// Advances the parser and returns the new current token.
+func (p *textParser) next() *token {
+	if p.backed || p.done {
+		p.backed = false
+		return &p.cur
+	}
+	p.advance()
+	if p.done {
+		p.cur.value = ""
+	} else if len(p.cur.value) > 0 && isQuote(p.cur.value[0]) {
+		// Look for multiple quoted strings separated by whitespace,
+		// and concatenate them.
+		cat := p.cur
+		for {
+			p.skipWhitespace()
+			if p.done || !isQuote(p.s[0]) {
+				break
+			}
+			p.advance()
+			if p.cur.err != nil {
+				return &p.cur
+			}
+			cat.value += " " + p.cur.value
+			cat.unquoted += p.cur.unquoted
+		}
+		p.done = false // parser may have seen EOF, but we want to return cat
+		p.cur = cat
+	}
+	return &p.cur
+}
+
+func (p *textParser) consumeToken(s string) error {
+	tok := p.next()
+	if tok.err != nil {
+		return tok.err
+	}
+	if tok.value != s {
+		p.back()
+		return p.errorf("expected %q, found %q", s, tok.value)
+	}
+	return nil
+}
+
+// Return a RequiredNotSetError indicating which required field was not set.
+func (p *textParser) missingRequiredFieldError(sv reflect.Value) *RequiredNotSetError {
+	st := sv.Type()
+	sprops := GetProperties(st)
+	for i := 0; i < st.NumField(); i++ {
+		if !isNil(sv.Field(i)) {
+			continue
+		}
+
+		props := sprops.Prop[i]
+		if props.Required {
+			return &RequiredNotSetError{fmt.Sprintf("%v.%v", st, props.OrigName)}
+		}
+	}
+	return &RequiredNotSetError{fmt.Sprintf("%v.<unknown field name>", st)} // should not happen
+}
+
+// Returns the index in the struct for the named field, as well as the parsed tag properties.
+func structFieldByName(sprops *StructProperties, name string) (int, *Properties, bool) {
+	i, ok := sprops.decoderOrigNames[name]
+	if ok {
+		return i, sprops.Prop[i], true
+	}
+	return -1, nil, false
+}
+
+// Consume a ':' from the input stream (if the next token is a colon),
+// returning an error if a colon is needed but not present.
+func (p *textParser) checkForColon(props *Properties, typ reflect.Type) *ParseError {
+	tok := p.next()
+	if tok.err != nil {
+		return tok.err
+	}
+	if tok.value != ":" {
+		// Colon is optional when the field is a group or message.
+		needColon := true
+		switch props.Wire {
+		case "group":
+			needColon = false
+		case "bytes":
+			// A "bytes" field is either a message, a string, or a repeated field;
+			// those three become *T, *string and []T respectively, so we can check for
+			// this field being a pointer to a non-string.
+			if typ.Kind() == reflect.Ptr {
+				// *T or *string
+				if typ.Elem().Kind() == reflect.String {
+					break
+				}
+			} else if typ.Kind() == reflect.Slice {
+				// []T or []*T
+				if typ.Elem().Kind() != reflect.Ptr {
+					break
+				}
+			} else if typ.Kind() == reflect.String {
+				// The proto3 exception is for a string field,
+				// which requires a colon.
+				break
+			}
+			needColon = false
+		}
+		if needColon {
+			return p.errorf("expected ':', found %q", tok.value)
+		}
+		p.back()
+	}
+	return nil
+}
+
+func (p *textParser) readStruct(sv reflect.Value, terminator string) error {
+	st := sv.Type()
+	sprops := GetProperties(st)
+	reqCount := sprops.reqCount
+	var reqFieldErr error
+	fieldSet := make(map[string]bool)
+	// A struct is a sequence of "name: value", terminated by one of
+	// '>' or '}', or the end of the input.  A name may also be
+	// "[extension]" or "[type/url]".
+	//
+	// The whole struct can also be an expanded Any message, like:
+	// [type/url] < ... struct contents ... >
+	for {
+		tok := p.next()
+		if tok.err != nil {
+			return tok.err
+		}
+		if tok.value == terminator {
+			break
+		}
+		if tok.value == "[" {
+			// Looks like an extension or an Any.
+			//
+			// TODO: Check whether we need to handle
+			// namespace rooted names (e.g. ".something.Foo").
+			extName, err := p.consumeExtName()
+			if err != nil {
+				return err
+			}
+
+			if s := strings.LastIndex(extName, "/"); s >= 0 {
+				// If it contains a slash, it's an Any type URL.
+				messageName := extName[s+1:]
+				mt := MessageType(messageName)
+				if mt == nil {
+					return p.errorf("unrecognized message %q in google.protobuf.Any", messageName)
+				}
+				tok = p.next()
+				if tok.err != nil {
+					return tok.err
+				}
+				// consume an optional colon
+				if tok.value == ":" {
+					tok = p.next()
+					if tok.err != nil {
+						return tok.err
+					}
+				}
+				var terminator string
+				switch tok.value {
+				case "<":
+					terminator = ">"
+				case "{":
+					terminator = "}"
+				default:
+					return p.errorf("expected '{' or '<', found %q", tok.value)
+				}
+				v := reflect.New(mt.Elem())
+				if pe := p.readStruct(v.Elem(), terminator); pe != nil {
+					return pe
+				}
+				b, err := Marshal(v.Interface().(Message))
+				if err != nil {
+					return p.errorf("failed to marshal message of type %q: %v", messageName, err)
+				}
+				if fieldSet["type_url"] {
+					return p.errorf(anyRepeatedlyUnpacked, "type_url")
+				}
+				if fieldSet["value"] {
+					return p.errorf(anyRepeatedlyUnpacked, "value")
+				}
+				sv.FieldByName("TypeUrl").SetString(extName)
+				sv.FieldByName("Value").SetBytes(b)
+				fieldSet["type_url"] = true
+				fieldSet["value"] = true
+				continue
+			}
+
+			var desc *ExtensionDesc
+			// This could be faster, but it's functional.
+			// TODO: Do something smarter than a linear scan.
+			for _, d := range RegisteredExtensions(reflect.New(st).Interface().(Message)) {
+				if d.Name == extName {
+					desc = d
+					break
+				}
+			}
+			if desc == nil {
+				return p.errorf("unrecognized extension %q", extName)
+			}
+
+			props := &Properties{}
+			props.Parse(desc.Tag)
+
+			typ := reflect.TypeOf(desc.ExtensionType)
+			if err := p.checkForColon(props, typ); err != nil {
+				return err
+			}
+
+			rep := desc.repeated()
+
+			// Read the extension structure, and set it in
+			// the value we're constructing.
+			var ext reflect.Value
+			if !rep {
+				ext = reflect.New(typ).Elem()
+			} else {
+				ext = reflect.New(typ.Elem()).Elem()
+			}
+			if err := p.readAny(ext, props); err != nil {
+				if _, ok := err.(*RequiredNotSetError); !ok {
+					return err
+				}
+				reqFieldErr = err
+			}
+			ep := sv.Addr().Interface().(Message)
+			if !rep {
+				SetExtension(ep, desc, ext.Interface())
+			} else {
+				old, err := GetExtension(ep, desc)
+				var sl reflect.Value
+				if err == nil {
+					sl = reflect.ValueOf(old) // existing slice
+				} else {
+					sl = reflect.MakeSlice(typ, 0, 1)
+				}
+				sl = reflect.Append(sl, ext)
+				SetExtension(ep, desc, sl.Interface())
+			}
+			if err := p.consumeOptionalSeparator(); err != nil {
+				return err
+			}
+			continue
+		}
+
+		// This is a normal, non-extension field.
+		name := tok.value
+		var dst reflect.Value
+		fi, props, ok := structFieldByName(sprops, name)
+		if ok {
+			dst = sv.Field(fi)
+		} else if oop, ok := sprops.OneofTypes[name]; ok {
+			// It is a oneof.
+			props = oop.Prop
+			nv := reflect.New(oop.Type.Elem())
+			dst = nv.Elem().Field(0)
+			field := sv.Field(oop.Field)
+			if !field.IsNil() {
+				return p.errorf("field '%s' would overwrite already parsed oneof '%s'", name, sv.Type().Field(oop.Field).Name)
+			}
+			field.Set(nv)
+		}
+		if !dst.IsValid() {
+			return p.errorf("unknown field name %q in %v", name, st)
+		}
+
+		if dst.Kind() == reflect.Map {
+			// Consume any colon.
+			if err := p.checkForColon(props, dst.Type()); err != nil {
+				return err
+			}
+
+			// Construct the map if it doesn't already exist.
+			if dst.IsNil() {
+				dst.Set(reflect.MakeMap(dst.Type()))
+			}
+			key := reflect.New(dst.Type().Key()).Elem()
+			val := reflect.New(dst.Type().Elem()).Elem()
+
+			// The map entry should be this sequence of tokens:
+			//	< key : KEY value : VALUE >
+			// However, implementations may omit key or value, and technically
+			// we should support them in any order.  See b/28924776 for a time
+			// this went wrong.
+
+			tok := p.next()
+			var terminator string
+			switch tok.value {
+			case "<":
+				terminator = ">"
+			case "{":
+				terminator = "}"
+			default:
+				return p.errorf("expected '{' or '<', found %q", tok.value)
+			}
+			for {
+				tok := p.next()
+				if tok.err != nil {
+					return tok.err
+				}
+				if tok.value == terminator {
+					break
+				}
+				switch tok.value {
+				case "key":
+					if err := p.consumeToken(":"); err != nil {
+						return err
+					}
+					if err := p.readAny(key, props.MapKeyProp); err != nil {
+						return err
+					}
+					if err := p.consumeOptionalSeparator(); err != nil {
+						return err
+					}
+				case "value":
+					if err := p.checkForColon(props.MapValProp, dst.Type().Elem()); err != nil {
+						return err
+					}
+					if err := p.readAny(val, props.MapValProp); err != nil {
+						return err
+					}
+					if err := p.consumeOptionalSeparator(); err != nil {
+						return err
+					}
+				default:
+					p.back()
+					return p.errorf(`expected "key", "value", or %q, found %q`, terminator, tok.value)
+				}
+			}
+
+			dst.SetMapIndex(key, val)
+			continue
+		}
+
+		// Check that it's not already set if it's not a repeated field.
+		if !props.Repeated && fieldSet[name] {
+			return p.errorf("non-repeated field %q was repeated", name)
+		}
+
+		if err := p.checkForColon(props, dst.Type()); err != nil {
+			return err
+		}
+
+		// Parse into the field.
+		fieldSet[name] = true
+		if err := p.readAny(dst, props); err != nil {
+			if _, ok := err.(*RequiredNotSetError); !ok {
+				return err
+			}
+			reqFieldErr = err
+		}
+		if props.Required {
+			reqCount--
+		}
+
+		if err := p.consumeOptionalSeparator(); err != nil {
+			return err
+		}
+
+	}
+
+	if reqCount > 0 {
+		return p.missingRequiredFieldError(sv)
+	}
+	return reqFieldErr
+}
+
+// consumeExtName consumes extension name or expanded Any type URL and the
+// following ']'. It returns the name or URL consumed.
+func (p *textParser) consumeExtName() (string, error) {
+	tok := p.next()
+	if tok.err != nil {
+		return "", tok.err
+	}
+
+	// If extension name or type url is quoted, it's a single token.
+	if len(tok.value) > 2 && isQuote(tok.value[0]) && tok.value[len(tok.value)-1] == tok.value[0] {
+		name, err := unquoteC(tok.value[1:len(tok.value)-1], rune(tok.value[0]))
+		if err != nil {
+			return "", err
+		}
+		return name, p.consumeToken("]")
+	}
+
+	// Consume everything up to "]"
+	var parts []string
+	for tok.value != "]" {
+		parts = append(parts, tok.value)
+		tok = p.next()
+		if tok.err != nil {
+			return "", p.errorf("unrecognized type_url or extension name: %s", tok.err)
+		}
+		if p.done && tok.value != "]" {
+			return "", p.errorf("unclosed type_url or extension name")
+		}
+	}
+	return strings.Join(parts, ""), nil
+}
+
+// consumeOptionalSeparator consumes an optional semicolon or comma.
+// It is used in readStruct to provide backward compatibility.
+func (p *textParser) consumeOptionalSeparator() error {
+	tok := p.next()
+	if tok.err != nil {
+		return tok.err
+	}
+	if tok.value != ";" && tok.value != "," {
+		p.back()
+	}
+	return nil
+}
+
+func (p *textParser) readAny(v reflect.Value, props *Properties) error {
+	tok := p.next()
+	if tok.err != nil {
+		return tok.err
+	}
+	if tok.value == "" {
+		return p.errorf("unexpected EOF")
+	}
+
+	switch fv := v; fv.Kind() {
+	case reflect.Slice:
+		at := v.Type()
+		if at.Elem().Kind() == reflect.Uint8 {
+			// Special case for []byte
+			if tok.value[0] != '"' && tok.value[0] != '\'' {
+				// Deliberately written out here, as the error after
+				// this switch statement would write "invalid []byte: ...",
+				// which is not as user-friendly.
+				return p.errorf("invalid string: %v", tok.value)
+			}
+			bytes := []byte(tok.unquoted)
+			fv.Set(reflect.ValueOf(bytes))
+			return nil
+		}
+		// Repeated field.
+		if tok.value == "[" {
+			// Repeated field with list notation, like [1,2,3].
+			for {
+				fv.Set(reflect.Append(fv, reflect.New(at.Elem()).Elem()))
+				err := p.readAny(fv.Index(fv.Len()-1), props)
+				if err != nil {
+					return err
+				}
+				tok := p.next()
+				if tok.err != nil {
+					return tok.err
+				}
+				if tok.value == "]" {
+					break
+				}
+				if tok.value != "," {
+					return p.errorf("Expected ']' or ',' found %q", tok.value)
+				}
+			}
+			return nil
+		}
+		// One value of the repeated field.
+		p.back()
+		fv.Set(reflect.Append(fv, reflect.New(at.Elem()).Elem()))
+		return p.readAny(fv.Index(fv.Len()-1), props)
+	case reflect.Bool:
+		// true/1/t/True or false/f/0/False.
+		switch tok.value {
+		case "true", "1", "t", "True":
+			fv.SetBool(true)
+			return nil
+		case "false", "0", "f", "False":
+			fv.SetBool(false)
+			return nil
+		}
+	case reflect.Float32, reflect.Float64:
+		v := tok.value
+		// Ignore 'f' for compatibility with output generated by C++, but don't
+		// remove 'f' when the value is "-inf" or "inf".
+		if strings.HasSuffix(v, "f") && tok.value != "-inf" && tok.value != "inf" {
+			v = v[:len(v)-1]
+		}
+		if f, err := strconv.ParseFloat(v, fv.Type().Bits()); err == nil {
+			fv.SetFloat(f)
+			return nil
+		}
+	case reflect.Int32:
+		if x, err := strconv.ParseInt(tok.value, 0, 32); err == nil {
+			fv.SetInt(x)
+			return nil
+		}
+
+		if len(props.Enum) == 0 {
+			break
+		}
+		m, ok := enumValueMaps[props.Enum]
+		if !ok {
+			break
+		}
+		x, ok := m[tok.value]
+		if !ok {
+			break
+		}
+		fv.SetInt(int64(x))
+		return nil
+	case reflect.Int64:
+		if x, err := strconv.ParseInt(tok.value, 0, 64); err == nil {
+			fv.SetInt(x)
+			return nil
+		}
+
+	case reflect.Ptr:
+		// A basic field (indirected through pointer), or a repeated message/group
+		p.back()
+		fv.Set(reflect.New(fv.Type().Elem()))
+		return p.readAny(fv.Elem(), props)
+	case reflect.String:
+		if tok.value[0] == '"' || tok.value[0] == '\'' {
+			fv.SetString(tok.unquoted)
+			return nil
+		}
+	case reflect.Struct:
+		var terminator string
+		switch tok.value {
+		case "{":
+			terminator = "}"
+		case "<":
+			terminator = ">"
+		default:
+			return p.errorf("expected '{' or '<', found %q", tok.value)
+		}
+		// TODO: Handle nested messages which implement encoding.TextUnmarshaler.
+		return p.readStruct(fv, terminator)
+	case reflect.Uint32:
+		if x, err := strconv.ParseUint(tok.value, 0, 32); err == nil {
+			fv.SetUint(uint64(x))
+			return nil
+		}
+	case reflect.Uint64:
+		if x, err := strconv.ParseUint(tok.value, 0, 64); err == nil {
+			fv.SetUint(x)
+			return nil
+		}
+	}
+	return p.errorf("invalid %v: %v", v.Type(), tok.value)
+}
+
+// UnmarshalText reads a protocol buffer in Text format. UnmarshalText resets pb
+// before starting to unmarshal, so any existing data in pb is always removed.
+// If a required field is not set and no other error occurs,
+// UnmarshalText returns *RequiredNotSetError.
+func UnmarshalText(s string, pb Message) error {
+	if um, ok := pb.(encoding.TextUnmarshaler); ok {
+		return um.UnmarshalText([]byte(s))
+	}
+	pb.Reset()
+	v := reflect.ValueOf(pb)
+	return newTextParser(s).readStruct(v.Elem(), "")
+}