[VOL-1386]  This commit add "dep" as the package management tool
for voltha-go.

Change-Id: I52bc4911dd00a441756ec7c30f46d45091f3f90e
diff --git a/vendor/github.com/golang/protobuf/AUTHORS b/vendor/github.com/golang/protobuf/AUTHORS
new file mode 100644
index 0000000..15167cd
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/AUTHORS
@@ -0,0 +1,3 @@
+# This source code refers to The Go Authors for copyright purposes.
+# The master list of authors is in the main Go distribution,
+# visible at http://tip.golang.org/AUTHORS.
diff --git a/vendor/github.com/golang/protobuf/CONTRIBUTORS b/vendor/github.com/golang/protobuf/CONTRIBUTORS
new file mode 100644
index 0000000..1c4577e
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/CONTRIBUTORS
@@ -0,0 +1,3 @@
+# This source code was written by the Go contributors.
+# The master list of contributors is in the main Go distribution,
+# visible at http://tip.golang.org/CONTRIBUTORS.
diff --git a/vendor/github.com/golang/protobuf/LICENSE b/vendor/github.com/golang/protobuf/LICENSE
new file mode 100644
index 0000000..0f64693
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/LICENSE
@@ -0,0 +1,28 @@
+Copyright 2010 The Go Authors.  All rights reserved.
+
+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.
+
diff --git a/vendor/github.com/golang/protobuf/descriptor/descriptor.go b/vendor/github.com/golang/protobuf/descriptor/descriptor.go
new file mode 100644
index 0000000..ac7e51b
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/descriptor/descriptor.go
@@ -0,0 +1,93 @@
+// 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 descriptor provides functions for obtaining protocol buffer
+// descriptors for generated Go types.
+//
+// These functions cannot go in package proto because they depend on the
+// generated protobuf descriptor messages, which themselves depend on proto.
+package descriptor
+
+import (
+	"bytes"
+	"compress/gzip"
+	"fmt"
+	"io/ioutil"
+
+	"github.com/golang/protobuf/proto"
+	protobuf "github.com/golang/protobuf/protoc-gen-go/descriptor"
+)
+
+// extractFile extracts a FileDescriptorProto from a gzip'd buffer.
+func extractFile(gz []byte) (*protobuf.FileDescriptorProto, error) {
+	r, err := gzip.NewReader(bytes.NewReader(gz))
+	if err != nil {
+		return nil, fmt.Errorf("failed to open gzip reader: %v", err)
+	}
+	defer r.Close()
+
+	b, err := ioutil.ReadAll(r)
+	if err != nil {
+		return nil, fmt.Errorf("failed to uncompress descriptor: %v", err)
+	}
+
+	fd := new(protobuf.FileDescriptorProto)
+	if err := proto.Unmarshal(b, fd); err != nil {
+		return nil, fmt.Errorf("malformed FileDescriptorProto: %v", err)
+	}
+
+	return fd, nil
+}
+
+// Message is a proto.Message with a method to return its descriptor.
+//
+// Message types generated by the protocol compiler always satisfy
+// the Message interface.
+type Message interface {
+	proto.Message
+	Descriptor() ([]byte, []int)
+}
+
+// ForMessage returns a FileDescriptorProto and a DescriptorProto from within it
+// describing the given message.
+func ForMessage(msg Message) (fd *protobuf.FileDescriptorProto, md *protobuf.DescriptorProto) {
+	gz, path := msg.Descriptor()
+	fd, err := extractFile(gz)
+	if err != nil {
+		panic(fmt.Sprintf("invalid FileDescriptorProto for %T: %v", msg, err))
+	}
+
+	md = fd.MessageType[path[0]]
+	for _, i := range path[1:] {
+		md = md.NestedType[i]
+	}
+	return fd, md
+}
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(), "")
+}
diff --git a/vendor/github.com/golang/protobuf/protoc-gen-go/descriptor/descriptor.proto b/vendor/github.com/golang/protobuf/protoc-gen-go/descriptor/descriptor.proto
new file mode 100644
index 0000000..8697a50
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/protoc-gen-go/descriptor/descriptor.proto
@@ -0,0 +1,872 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// 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.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+//
+// The messages in this file describe the definitions found in .proto files.
+// A valid .proto file can be translated directly to a FileDescriptorProto
+// without any other information (e.g. without reading its imports).
+
+
+syntax = "proto2";
+
+package google.protobuf;
+option go_package = "github.com/golang/protobuf/protoc-gen-go/descriptor;descriptor";
+option java_package = "com.google.protobuf";
+option java_outer_classname = "DescriptorProtos";
+option csharp_namespace = "Google.Protobuf.Reflection";
+option objc_class_prefix = "GPB";
+option cc_enable_arenas = true;
+
+// descriptor.proto must be optimized for speed because reflection-based
+// algorithms don't work during bootstrapping.
+option optimize_for = SPEED;
+
+// The protocol compiler can output a FileDescriptorSet containing the .proto
+// files it parses.
+message FileDescriptorSet {
+  repeated FileDescriptorProto file = 1;
+}
+
+// Describes a complete .proto file.
+message FileDescriptorProto {
+  optional string name = 1;       // file name, relative to root of source tree
+  optional string package = 2;    // e.g. "foo", "foo.bar", etc.
+
+  // Names of files imported by this file.
+  repeated string dependency = 3;
+  // Indexes of the public imported files in the dependency list above.
+  repeated int32 public_dependency = 10;
+  // Indexes of the weak imported files in the dependency list.
+  // For Google-internal migration only. Do not use.
+  repeated int32 weak_dependency = 11;
+
+  // All top-level definitions in this file.
+  repeated DescriptorProto message_type = 4;
+  repeated EnumDescriptorProto enum_type = 5;
+  repeated ServiceDescriptorProto service = 6;
+  repeated FieldDescriptorProto extension = 7;
+
+  optional FileOptions options = 8;
+
+  // This field contains optional information about the original source code.
+  // You may safely remove this entire field without harming runtime
+  // functionality of the descriptors -- the information is needed only by
+  // development tools.
+  optional SourceCodeInfo source_code_info = 9;
+
+  // The syntax of the proto file.
+  // The supported values are "proto2" and "proto3".
+  optional string syntax = 12;
+}
+
+// Describes a message type.
+message DescriptorProto {
+  optional string name = 1;
+
+  repeated FieldDescriptorProto field = 2;
+  repeated FieldDescriptorProto extension = 6;
+
+  repeated DescriptorProto nested_type = 3;
+  repeated EnumDescriptorProto enum_type = 4;
+
+  message ExtensionRange {
+    optional int32 start = 1;
+    optional int32 end = 2;
+
+    optional ExtensionRangeOptions options = 3;
+  }
+  repeated ExtensionRange extension_range = 5;
+
+  repeated OneofDescriptorProto oneof_decl = 8;
+
+  optional MessageOptions options = 7;
+
+  // Range of reserved tag numbers. Reserved tag numbers may not be used by
+  // fields or extension ranges in the same message. Reserved ranges may
+  // not overlap.
+  message ReservedRange {
+    optional int32 start = 1; // Inclusive.
+    optional int32 end = 2;   // Exclusive.
+  }
+  repeated ReservedRange reserved_range = 9;
+  // Reserved field names, which may not be used by fields in the same message.
+  // A given name may only be reserved once.
+  repeated string reserved_name = 10;
+}
+
+message ExtensionRangeOptions {
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+// Describes a field within a message.
+message FieldDescriptorProto {
+  enum Type {
+    // 0 is reserved for errors.
+    // Order is weird for historical reasons.
+    TYPE_DOUBLE         = 1;
+    TYPE_FLOAT          = 2;
+    // Not ZigZag encoded.  Negative numbers take 10 bytes.  Use TYPE_SINT64 if
+    // negative values are likely.
+    TYPE_INT64          = 3;
+    TYPE_UINT64         = 4;
+    // Not ZigZag encoded.  Negative numbers take 10 bytes.  Use TYPE_SINT32 if
+    // negative values are likely.
+    TYPE_INT32          = 5;
+    TYPE_FIXED64        = 6;
+    TYPE_FIXED32        = 7;
+    TYPE_BOOL           = 8;
+    TYPE_STRING         = 9;
+    // Tag-delimited aggregate.
+    // Group type is deprecated and not supported in proto3. However, Proto3
+    // implementations should still be able to parse the group wire format and
+    // treat group fields as unknown fields.
+    TYPE_GROUP          = 10;
+    TYPE_MESSAGE        = 11;  // Length-delimited aggregate.
+
+    // New in version 2.
+    TYPE_BYTES          = 12;
+    TYPE_UINT32         = 13;
+    TYPE_ENUM           = 14;
+    TYPE_SFIXED32       = 15;
+    TYPE_SFIXED64       = 16;
+    TYPE_SINT32         = 17;  // Uses ZigZag encoding.
+    TYPE_SINT64         = 18;  // Uses ZigZag encoding.
+  };
+
+  enum Label {
+    // 0 is reserved for errors
+    LABEL_OPTIONAL      = 1;
+    LABEL_REQUIRED      = 2;
+    LABEL_REPEATED      = 3;
+  };
+
+  optional string name = 1;
+  optional int32 number = 3;
+  optional Label label = 4;
+
+  // If type_name is set, this need not be set.  If both this and type_name
+  // are set, this must be one of TYPE_ENUM, TYPE_MESSAGE or TYPE_GROUP.
+  optional Type type = 5;
+
+  // For message and enum types, this is the name of the type.  If the name
+  // starts with a '.', it is fully-qualified.  Otherwise, C++-like scoping
+  // rules are used to find the type (i.e. first the nested types within this
+  // message are searched, then within the parent, on up to the root
+  // namespace).
+  optional string type_name = 6;
+
+  // For extensions, this is the name of the type being extended.  It is
+  // resolved in the same manner as type_name.
+  optional string extendee = 2;
+
+  // For numeric types, contains the original text representation of the value.
+  // For booleans, "true" or "false".
+  // For strings, contains the default text contents (not escaped in any way).
+  // For bytes, contains the C escaped value.  All bytes >= 128 are escaped.
+  // TODO(kenton):  Base-64 encode?
+  optional string default_value = 7;
+
+  // If set, gives the index of a oneof in the containing type's oneof_decl
+  // list.  This field is a member of that oneof.
+  optional int32 oneof_index = 9;
+
+  // JSON name of this field. The value is set by protocol compiler. If the
+  // user has set a "json_name" option on this field, that option's value
+  // will be used. Otherwise, it's deduced from the field's name by converting
+  // it to camelCase.
+  optional string json_name = 10;
+
+  optional FieldOptions options = 8;
+}
+
+// Describes a oneof.
+message OneofDescriptorProto {
+  optional string name = 1;
+  optional OneofOptions options = 2;
+}
+
+// Describes an enum type.
+message EnumDescriptorProto {
+  optional string name = 1;
+
+  repeated EnumValueDescriptorProto value = 2;
+
+  optional EnumOptions options = 3;
+
+  // Range of reserved numeric values. Reserved values may not be used by
+  // entries in the same enum. Reserved ranges may not overlap.
+  //
+  // Note that this is distinct from DescriptorProto.ReservedRange in that it
+  // is inclusive such that it can appropriately represent the entire int32
+  // domain.
+  message EnumReservedRange {
+    optional int32 start = 1; // Inclusive.
+    optional int32 end = 2;   // Inclusive.
+  }
+
+  // Range of reserved numeric values. Reserved numeric values may not be used
+  // by enum values in the same enum declaration. Reserved ranges may not
+  // overlap.
+  repeated EnumReservedRange reserved_range = 4;
+
+  // Reserved enum value names, which may not be reused. A given name may only
+  // be reserved once.
+  repeated string reserved_name = 5;
+}
+
+// Describes a value within an enum.
+message EnumValueDescriptorProto {
+  optional string name = 1;
+  optional int32 number = 2;
+
+  optional EnumValueOptions options = 3;
+}
+
+// Describes a service.
+message ServiceDescriptorProto {
+  optional string name = 1;
+  repeated MethodDescriptorProto method = 2;
+
+  optional ServiceOptions options = 3;
+}
+
+// Describes a method of a service.
+message MethodDescriptorProto {
+  optional string name = 1;
+
+  // Input and output type names.  These are resolved in the same way as
+  // FieldDescriptorProto.type_name, but must refer to a message type.
+  optional string input_type = 2;
+  optional string output_type = 3;
+
+  optional MethodOptions options = 4;
+
+  // Identifies if client streams multiple client messages
+  optional bool client_streaming = 5 [default=false];
+  // Identifies if server streams multiple server messages
+  optional bool server_streaming = 6 [default=false];
+}
+
+
+// ===================================================================
+// Options
+
+// Each of the definitions above may have "options" attached.  These are
+// just annotations which may cause code to be generated slightly differently
+// or may contain hints for code that manipulates protocol messages.
+//
+// Clients may define custom options as extensions of the *Options messages.
+// These extensions may not yet be known at parsing time, so the parser cannot
+// store the values in them.  Instead it stores them in a field in the *Options
+// message called uninterpreted_option. This field must have the same name
+// across all *Options messages. We then use this field to populate the
+// extensions when we build a descriptor, at which point all protos have been
+// parsed and so all extensions are known.
+//
+// Extension numbers for custom options may be chosen as follows:
+// * For options which will only be used within a single application or
+//   organization, or for experimental options, use field numbers 50000
+//   through 99999.  It is up to you to ensure that you do not use the
+//   same number for multiple options.
+// * For options which will be published and used publicly by multiple
+//   independent entities, e-mail protobuf-global-extension-registry@google.com
+//   to reserve extension numbers. Simply provide your project name (e.g.
+//   Objective-C plugin) and your project website (if available) -- there's no
+//   need to explain how you intend to use them. Usually you only need one
+//   extension number. You can declare multiple options with only one extension
+//   number by putting them in a sub-message. See the Custom Options section of
+//   the docs for examples:
+//   https://developers.google.com/protocol-buffers/docs/proto#options
+//   If this turns out to be popular, a web service will be set up
+//   to automatically assign option numbers.
+
+
+message FileOptions {
+
+  // Sets the Java package where classes generated from this .proto will be
+  // placed.  By default, the proto package is used, but this is often
+  // inappropriate because proto packages do not normally start with backwards
+  // domain names.
+  optional string java_package = 1;
+
+
+  // If set, all the classes from the .proto file are wrapped in a single
+  // outer class with the given name.  This applies to both Proto1
+  // (equivalent to the old "--one_java_file" option) and Proto2 (where
+  // a .proto always translates to a single class, but you may want to
+  // explicitly choose the class name).
+  optional string java_outer_classname = 8;
+
+  // If set true, then the Java code generator will generate a separate .java
+  // file for each top-level message, enum, and service defined in the .proto
+  // file.  Thus, these types will *not* be nested inside the outer class
+  // named by java_outer_classname.  However, the outer class will still be
+  // generated to contain the file's getDescriptor() method as well as any
+  // top-level extensions defined in the file.
+  optional bool java_multiple_files = 10 [default=false];
+
+  // This option does nothing.
+  optional bool java_generate_equals_and_hash = 20 [deprecated=true];
+
+  // If set true, then the Java2 code generator will generate code that
+  // throws an exception whenever an attempt is made to assign a non-UTF-8
+  // byte sequence to a string field.
+  // Message reflection will do the same.
+  // However, an extension field still accepts non-UTF-8 byte sequences.
+  // This option has no effect on when used with the lite runtime.
+  optional bool java_string_check_utf8 = 27 [default=false];
+
+
+  // Generated classes can be optimized for speed or code size.
+  enum OptimizeMode {
+    SPEED = 1;        // Generate complete code for parsing, serialization,
+                      // etc.
+    CODE_SIZE = 2;    // Use ReflectionOps to implement these methods.
+    LITE_RUNTIME = 3; // Generate code using MessageLite and the lite runtime.
+  }
+  optional OptimizeMode optimize_for = 9 [default=SPEED];
+
+  // Sets the Go package where structs generated from this .proto will be
+  // placed. If omitted, the Go package will be derived from the following:
+  //   - The basename of the package import path, if provided.
+  //   - Otherwise, the package statement in the .proto file, if present.
+  //   - Otherwise, the basename of the .proto file, without extension.
+  optional string go_package = 11;
+
+
+
+  // Should generic services be generated in each language?  "Generic" services
+  // are not specific to any particular RPC system.  They are generated by the
+  // main code generators in each language (without additional plugins).
+  // Generic services were the only kind of service generation supported by
+  // early versions of google.protobuf.
+  //
+  // Generic services are now considered deprecated in favor of using plugins
+  // that generate code specific to your particular RPC system.  Therefore,
+  // these default to false.  Old code which depends on generic services should
+  // explicitly set them to true.
+  optional bool cc_generic_services = 16 [default=false];
+  optional bool java_generic_services = 17 [default=false];
+  optional bool py_generic_services = 18 [default=false];
+  optional bool php_generic_services = 42 [default=false];
+
+  // Is this file deprecated?
+  // Depending on the target platform, this can emit Deprecated annotations
+  // for everything in the file, or it will be completely ignored; in the very
+  // least, this is a formalization for deprecating files.
+  optional bool deprecated = 23 [default=false];
+
+  // Enables the use of arenas for the proto messages in this file. This applies
+  // only to generated classes for C++.
+  optional bool cc_enable_arenas = 31 [default=false];
+
+
+  // Sets the objective c class prefix which is prepended to all objective c
+  // generated classes from this .proto. There is no default.
+  optional string objc_class_prefix = 36;
+
+  // Namespace for generated classes; defaults to the package.
+  optional string csharp_namespace = 37;
+
+  // By default Swift generators will take the proto package and CamelCase it
+  // replacing '.' with underscore and use that to prefix the types/symbols
+  // defined. When this options is provided, they will use this value instead
+  // to prefix the types/symbols defined.
+  optional string swift_prefix = 39;
+
+  // Sets the php class prefix which is prepended to all php generated classes
+  // from this .proto. Default is empty.
+  optional string php_class_prefix = 40;
+
+  // Use this option to change the namespace of php generated classes. Default
+  // is empty. When this option is empty, the package name will be used for
+  // determining the namespace.
+  optional string php_namespace = 41;
+
+  // The parser stores options it doesn't recognize here.
+  // See the documentation for the "Options" section above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message.
+  // See the documentation for the "Options" section above.
+  extensions 1000 to max;
+
+  reserved 38;
+}
+
+message MessageOptions {
+  // Set true to use the old proto1 MessageSet wire format for extensions.
+  // This is provided for backwards-compatibility with the MessageSet wire
+  // format.  You should not use this for any other reason:  It's less
+  // efficient, has fewer features, and is more complicated.
+  //
+  // The message must be defined exactly as follows:
+  //   message Foo {
+  //     option message_set_wire_format = true;
+  //     extensions 4 to max;
+  //   }
+  // Note that the message cannot have any defined fields; MessageSets only
+  // have extensions.
+  //
+  // All extensions of your type must be singular messages; e.g. they cannot
+  // be int32s, enums, or repeated messages.
+  //
+  // Because this is an option, the above two restrictions are not enforced by
+  // the protocol compiler.
+  optional bool message_set_wire_format = 1 [default=false];
+
+  // Disables the generation of the standard "descriptor()" accessor, which can
+  // conflict with a field of the same name.  This is meant to make migration
+  // from proto1 easier; new code should avoid fields named "descriptor".
+  optional bool no_standard_descriptor_accessor = 2 [default=false];
+
+  // Is this message deprecated?
+  // Depending on the target platform, this can emit Deprecated annotations
+  // for the message, or it will be completely ignored; in the very least,
+  // this is a formalization for deprecating messages.
+  optional bool deprecated = 3 [default=false];
+
+  // Whether the message is an automatically generated map entry type for the
+  // maps field.
+  //
+  // For maps fields:
+  //     map<KeyType, ValueType> map_field = 1;
+  // The parsed descriptor looks like:
+  //     message MapFieldEntry {
+  //         option map_entry = true;
+  //         optional KeyType key = 1;
+  //         optional ValueType value = 2;
+  //     }
+  //     repeated MapFieldEntry map_field = 1;
+  //
+  // Implementations may choose not to generate the map_entry=true message, but
+  // use a native map in the target language to hold the keys and values.
+  // The reflection APIs in such implementions still need to work as
+  // if the field is a repeated message field.
+  //
+  // NOTE: Do not set the option in .proto files. Always use the maps syntax
+  // instead. The option should only be implicitly set by the proto compiler
+  // parser.
+  optional bool map_entry = 7;
+
+  reserved 8;  // javalite_serializable
+  reserved 9;  // javanano_as_lite
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+message FieldOptions {
+  // The ctype option instructs the C++ code generator to use a different
+  // representation of the field than it normally would.  See the specific
+  // options below.  This option is not yet implemented in the open source
+  // release -- sorry, we'll try to include it in a future version!
+  optional CType ctype = 1 [default = STRING];
+  enum CType {
+    // Default mode.
+    STRING = 0;
+
+    CORD = 1;
+
+    STRING_PIECE = 2;
+  }
+  // The packed option can be enabled for repeated primitive fields to enable
+  // a more efficient representation on the wire. Rather than repeatedly
+  // writing the tag and type for each element, the entire array is encoded as
+  // a single length-delimited blob. In proto3, only explicit setting it to
+  // false will avoid using packed encoding.
+  optional bool packed = 2;
+
+  // The jstype option determines the JavaScript type used for values of the
+  // field.  The option is permitted only for 64 bit integral and fixed types
+  // (int64, uint64, sint64, fixed64, sfixed64).  A field with jstype JS_STRING
+  // is represented as JavaScript string, which avoids loss of precision that
+  // can happen when a large value is converted to a floating point JavaScript.
+  // Specifying JS_NUMBER for the jstype causes the generated JavaScript code to
+  // use the JavaScript "number" type.  The behavior of the default option
+  // JS_NORMAL is implementation dependent.
+  //
+  // This option is an enum to permit additional types to be added, e.g.
+  // goog.math.Integer.
+  optional JSType jstype = 6 [default = JS_NORMAL];
+  enum JSType {
+    // Use the default type.
+    JS_NORMAL = 0;
+
+    // Use JavaScript strings.
+    JS_STRING = 1;
+
+    // Use JavaScript numbers.
+    JS_NUMBER = 2;
+  }
+
+  // Should this field be parsed lazily?  Lazy applies only to message-type
+  // fields.  It means that when the outer message is initially parsed, the
+  // inner message's contents will not be parsed but instead stored in encoded
+  // form.  The inner message will actually be parsed when it is first accessed.
+  //
+  // This is only a hint.  Implementations are free to choose whether to use
+  // eager or lazy parsing regardless of the value of this option.  However,
+  // setting this option true suggests that the protocol author believes that
+  // using lazy parsing on this field is worth the additional bookkeeping
+  // overhead typically needed to implement it.
+  //
+  // This option does not affect the public interface of any generated code;
+  // all method signatures remain the same.  Furthermore, thread-safety of the
+  // interface is not affected by this option; const methods remain safe to
+  // call from multiple threads concurrently, while non-const methods continue
+  // to require exclusive access.
+  //
+  //
+  // Note that implementations may choose not to check required fields within
+  // a lazy sub-message.  That is, calling IsInitialized() on the outer message
+  // may return true even if the inner message has missing required fields.
+  // This is necessary because otherwise the inner message would have to be
+  // parsed in order to perform the check, defeating the purpose of lazy
+  // parsing.  An implementation which chooses not to check required fields
+  // must be consistent about it.  That is, for any particular sub-message, the
+  // implementation must either *always* check its required fields, or *never*
+  // check its required fields, regardless of whether or not the message has
+  // been parsed.
+  optional bool lazy = 5 [default=false];
+
+  // Is this field deprecated?
+  // Depending on the target platform, this can emit Deprecated annotations
+  // for accessors, or it will be completely ignored; in the very least, this
+  // is a formalization for deprecating fields.
+  optional bool deprecated = 3 [default=false];
+
+  // For Google-internal migration only. Do not use.
+  optional bool weak = 10 [default=false];
+
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+
+  reserved 4;  // removed jtype
+}
+
+message OneofOptions {
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+message EnumOptions {
+
+  // Set this option to true to allow mapping different tag names to the same
+  // value.
+  optional bool allow_alias = 2;
+
+  // Is this enum deprecated?
+  // Depending on the target platform, this can emit Deprecated annotations
+  // for the enum, or it will be completely ignored; in the very least, this
+  // is a formalization for deprecating enums.
+  optional bool deprecated = 3 [default=false];
+
+  reserved 5;  // javanano_as_lite
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+message EnumValueOptions {
+  // Is this enum value deprecated?
+  // Depending on the target platform, this can emit Deprecated annotations
+  // for the enum value, or it will be completely ignored; in the very least,
+  // this is a formalization for deprecating enum values.
+  optional bool deprecated = 1 [default=false];
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+message ServiceOptions {
+
+  // Note:  Field numbers 1 through 32 are reserved for Google's internal RPC
+  //   framework.  We apologize for hoarding these numbers to ourselves, but
+  //   we were already using them long before we decided to release Protocol
+  //   Buffers.
+
+  // Is this service deprecated?
+  // Depending on the target platform, this can emit Deprecated annotations
+  // for the service, or it will be completely ignored; in the very least,
+  // this is a formalization for deprecating services.
+  optional bool deprecated = 33 [default=false];
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+message MethodOptions {
+
+  // Note:  Field numbers 1 through 32 are reserved for Google's internal RPC
+  //   framework.  We apologize for hoarding these numbers to ourselves, but
+  //   we were already using them long before we decided to release Protocol
+  //   Buffers.
+
+  // Is this method deprecated?
+  // Depending on the target platform, this can emit Deprecated annotations
+  // for the method, or it will be completely ignored; in the very least,
+  // this is a formalization for deprecating methods.
+  optional bool deprecated = 33 [default=false];
+
+  // Is this method side-effect-free (or safe in HTTP parlance), or idempotent,
+  // or neither? HTTP based RPC implementation may choose GET verb for safe
+  // methods, and PUT verb for idempotent methods instead of the default POST.
+  enum IdempotencyLevel {
+    IDEMPOTENCY_UNKNOWN = 0;
+    NO_SIDE_EFFECTS     = 1; // implies idempotent
+    IDEMPOTENT          = 2; // idempotent, but may have side effects
+  }
+  optional IdempotencyLevel idempotency_level =
+      34 [default=IDEMPOTENCY_UNKNOWN];
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+
+// A message representing a option the parser does not recognize. This only
+// appears in options protos created by the compiler::Parser class.
+// DescriptorPool resolves these when building Descriptor objects. Therefore,
+// options protos in descriptor objects (e.g. returned by Descriptor::options(),
+// or produced by Descriptor::CopyTo()) will never have UninterpretedOptions
+// in them.
+message UninterpretedOption {
+  // The name of the uninterpreted option.  Each string represents a segment in
+  // a dot-separated name.  is_extension is true iff a segment represents an
+  // extension (denoted with parentheses in options specs in .proto files).
+  // E.g.,{ ["foo", false], ["bar.baz", true], ["qux", false] } represents
+  // "foo.(bar.baz).qux".
+  message NamePart {
+    required string name_part = 1;
+    required bool is_extension = 2;
+  }
+  repeated NamePart name = 2;
+
+  // The value of the uninterpreted option, in whatever type the tokenizer
+  // identified it as during parsing. Exactly one of these should be set.
+  optional string identifier_value = 3;
+  optional uint64 positive_int_value = 4;
+  optional int64 negative_int_value = 5;
+  optional double double_value = 6;
+  optional bytes string_value = 7;
+  optional string aggregate_value = 8;
+}
+
+// ===================================================================
+// Optional source code info
+
+// Encapsulates information about the original source file from which a
+// FileDescriptorProto was generated.
+message SourceCodeInfo {
+  // A Location identifies a piece of source code in a .proto file which
+  // corresponds to a particular definition.  This information is intended
+  // to be useful to IDEs, code indexers, documentation generators, and similar
+  // tools.
+  //
+  // For example, say we have a file like:
+  //   message Foo {
+  //     optional string foo = 1;
+  //   }
+  // Let's look at just the field definition:
+  //   optional string foo = 1;
+  //   ^       ^^     ^^  ^  ^^^
+  //   a       bc     de  f  ghi
+  // We have the following locations:
+  //   span   path               represents
+  //   [a,i)  [ 4, 0, 2, 0 ]     The whole field definition.
+  //   [a,b)  [ 4, 0, 2, 0, 4 ]  The label (optional).
+  //   [c,d)  [ 4, 0, 2, 0, 5 ]  The type (string).
+  //   [e,f)  [ 4, 0, 2, 0, 1 ]  The name (foo).
+  //   [g,h)  [ 4, 0, 2, 0, 3 ]  The number (1).
+  //
+  // Notes:
+  // - A location may refer to a repeated field itself (i.e. not to any
+  //   particular index within it).  This is used whenever a set of elements are
+  //   logically enclosed in a single code segment.  For example, an entire
+  //   extend block (possibly containing multiple extension definitions) will
+  //   have an outer location whose path refers to the "extensions" repeated
+  //   field without an index.
+  // - Multiple locations may have the same path.  This happens when a single
+  //   logical declaration is spread out across multiple places.  The most
+  //   obvious example is the "extend" block again -- there may be multiple
+  //   extend blocks in the same scope, each of which will have the same path.
+  // - A location's span is not always a subset of its parent's span.  For
+  //   example, the "extendee" of an extension declaration appears at the
+  //   beginning of the "extend" block and is shared by all extensions within
+  //   the block.
+  // - Just because a location's span is a subset of some other location's span
+  //   does not mean that it is a descendent.  For example, a "group" defines
+  //   both a type and a field in a single declaration.  Thus, the locations
+  //   corresponding to the type and field and their components will overlap.
+  // - Code which tries to interpret locations should probably be designed to
+  //   ignore those that it doesn't understand, as more types of locations could
+  //   be recorded in the future.
+  repeated Location location = 1;
+  message Location {
+    // Identifies which part of the FileDescriptorProto was defined at this
+    // location.
+    //
+    // Each element is a field number or an index.  They form a path from
+    // the root FileDescriptorProto to the place where the definition.  For
+    // example, this path:
+    //   [ 4, 3, 2, 7, 1 ]
+    // refers to:
+    //   file.message_type(3)  // 4, 3
+    //       .field(7)         // 2, 7
+    //       .name()           // 1
+    // This is because FileDescriptorProto.message_type has field number 4:
+    //   repeated DescriptorProto message_type = 4;
+    // and DescriptorProto.field has field number 2:
+    //   repeated FieldDescriptorProto field = 2;
+    // and FieldDescriptorProto.name has field number 1:
+    //   optional string name = 1;
+    //
+    // Thus, the above path gives the location of a field name.  If we removed
+    // the last element:
+    //   [ 4, 3, 2, 7 ]
+    // this path refers to the whole field declaration (from the beginning
+    // of the label to the terminating semicolon).
+    repeated int32 path = 1 [packed=true];
+
+    // Always has exactly three or four elements: start line, start column,
+    // end line (optional, otherwise assumed same as start line), end column.
+    // These are packed into a single field for efficiency.  Note that line
+    // and column numbers are zero-based -- typically you will want to add
+    // 1 to each before displaying to a user.
+    repeated int32 span = 2 [packed=true];
+
+    // If this SourceCodeInfo represents a complete declaration, these are any
+    // comments appearing before and after the declaration which appear to be
+    // attached to the declaration.
+    //
+    // A series of line comments appearing on consecutive lines, with no other
+    // tokens appearing on those lines, will be treated as a single comment.
+    //
+    // leading_detached_comments will keep paragraphs of comments that appear
+    // before (but not connected to) the current element. Each paragraph,
+    // separated by empty lines, will be one comment element in the repeated
+    // field.
+    //
+    // Only the comment content is provided; comment markers (e.g. //) are
+    // stripped out.  For block comments, leading whitespace and an asterisk
+    // will be stripped from the beginning of each line other than the first.
+    // Newlines are included in the output.
+    //
+    // Examples:
+    //
+    //   optional int32 foo = 1;  // Comment attached to foo.
+    //   // Comment attached to bar.
+    //   optional int32 bar = 2;
+    //
+    //   optional string baz = 3;
+    //   // Comment attached to baz.
+    //   // Another line attached to baz.
+    //
+    //   // Comment attached to qux.
+    //   //
+    //   // Another line attached to qux.
+    //   optional double qux = 4;
+    //
+    //   // Detached comment for corge. This is not leading or trailing comments
+    //   // to qux or corge because there are blank lines separating it from
+    //   // both.
+    //
+    //   // Detached comment for corge paragraph 2.
+    //
+    //   optional string corge = 5;
+    //   /* Block comment attached
+    //    * to corge.  Leading asterisks
+    //    * will be removed. */
+    //   /* Block comment attached to
+    //    * grault. */
+    //   optional int32 grault = 6;
+    //
+    //   // ignored detached comments.
+    optional string leading_comments = 3;
+    optional string trailing_comments = 4;
+    repeated string leading_detached_comments = 6;
+  }
+}
+
+// Describes the relationship between generated code and its original source
+// file. A GeneratedCodeInfo message is associated with only one generated
+// source file, but may contain references to different source .proto files.
+message GeneratedCodeInfo {
+  // An Annotation connects some span of text in generated code to an element
+  // of its generating .proto file.
+  repeated Annotation annotation = 1;
+  message Annotation {
+    // Identifies the element in the original source .proto file. This field
+    // is formatted the same as SourceCodeInfo.Location.path.
+    repeated int32 path = 1 [packed=true];
+
+    // Identifies the filesystem path to the original source .proto.
+    optional string source_file = 2;
+
+    // Identifies the starting offset in bytes in the generated code
+    // that relates to the identified object.
+    optional int32 begin = 3;
+
+    // Identifies the ending offset in bytes in the generated code that
+    // relates to the identified offset. The end offset should be one past
+    // the last relevant byte (so the length of the text = end - begin).
+    optional int32 end = 4;
+  }
+}
diff --git a/vendor/github.com/golang/protobuf/protoc-gen-go/doc.go b/vendor/github.com/golang/protobuf/protoc-gen-go/doc.go
new file mode 100644
index 0000000..0d6055d
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/protoc-gen-go/doc.go
@@ -0,0 +1,51 @@
+// 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.
+
+/*
+	A plugin for the Google protocol buffer compiler to generate Go code.
+	Run it by building this program and putting it in your path with the name
+		protoc-gen-go
+	That word 'go' at the end becomes part of the option string set for the
+	protocol compiler, so once the protocol compiler (protoc) is installed
+	you can run
+		protoc --go_out=output_directory input_directory/file.proto
+	to generate Go bindings for the protocol defined by file.proto.
+	With that input, the output will be written to
+		output_directory/file.pb.go
+
+	The generated code is documented in the package comment for
+	the library.
+
+	See the README and documentation for protocol buffers to learn more:
+		https://developers.google.com/protocol-buffers/
+
+*/
+package documentation
diff --git a/vendor/github.com/golang/protobuf/protoc-gen-go/generator/generator.go b/vendor/github.com/golang/protobuf/protoc-gen-go/generator/generator.go
new file mode 100644
index 0000000..c13a9f1
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/protoc-gen-go/generator/generator.go
@@ -0,0 +1,3086 @@
+// 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.
+
+/*
+	The code generator for the plugin for the Google protocol buffer compiler.
+	It generates Go code from the protocol buffer description files read by the
+	main routine.
+*/
+package generator
+
+import (
+	"bufio"
+	"bytes"
+	"compress/gzip"
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"go/build"
+	"go/parser"
+	"go/printer"
+	"go/token"
+	"log"
+	"os"
+	"path"
+	"sort"
+	"strconv"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/protoc-gen-go/generator/internal/remap"
+
+	"github.com/golang/protobuf/protoc-gen-go/descriptor"
+	plugin "github.com/golang/protobuf/protoc-gen-go/plugin"
+)
+
+// generatedCodeVersion indicates a version of the generated code.
+// It is incremented whenever an incompatibility between the generated code and
+// proto package is introduced; the generated code references
+// a constant, proto.ProtoPackageIsVersionN (where N is generatedCodeVersion).
+const generatedCodeVersion = 2
+
+// A Plugin provides functionality to add to the output during Go code generation,
+// such as to produce RPC stubs.
+type Plugin interface {
+	// Name identifies the plugin.
+	Name() string
+	// Init is called once after data structures are built but before
+	// code generation begins.
+	Init(g *Generator)
+	// Generate produces the code generated by the plugin for this file,
+	// except for the imports, by calling the generator's methods P, In, and Out.
+	Generate(file *FileDescriptor)
+	// GenerateImports produces the import declarations for this file.
+	// It is called after Generate.
+	GenerateImports(file *FileDescriptor)
+}
+
+var plugins []Plugin
+
+// RegisterPlugin installs a (second-order) plugin to be run when the Go output is generated.
+// It is typically called during initialization.
+func RegisterPlugin(p Plugin) {
+	plugins = append(plugins, p)
+}
+
+// A GoImportPath is the import path of a Go package. e.g., "google.golang.org/genproto/protobuf".
+type GoImportPath string
+
+func (p GoImportPath) String() string { return strconv.Quote(string(p)) }
+
+// A GoPackageName is the name of a Go package. e.g., "protobuf".
+type GoPackageName string
+
+// Each type we import as a protocol buffer (other than FileDescriptorProto) needs
+// a pointer to the FileDescriptorProto that represents it.  These types achieve that
+// wrapping by placing each Proto inside a struct with the pointer to its File. The
+// structs have the same names as their contents, with "Proto" removed.
+// FileDescriptor is used to store the things that it points to.
+
+// The file and package name method are common to messages and enums.
+type common struct {
+	file *FileDescriptor // File this object comes from.
+}
+
+// GoImportPath is the import path of the Go package containing the type.
+func (c *common) GoImportPath() GoImportPath {
+	return c.file.importPath
+}
+
+func (c *common) File() *FileDescriptor { return c.file }
+
+func fileIsProto3(file *descriptor.FileDescriptorProto) bool {
+	return file.GetSyntax() == "proto3"
+}
+
+func (c *common) proto3() bool { return fileIsProto3(c.file.FileDescriptorProto) }
+
+// Descriptor represents a protocol buffer message.
+type Descriptor struct {
+	common
+	*descriptor.DescriptorProto
+	parent   *Descriptor            // The containing message, if any.
+	nested   []*Descriptor          // Inner messages, if any.
+	enums    []*EnumDescriptor      // Inner enums, if any.
+	ext      []*ExtensionDescriptor // Extensions, if any.
+	typename []string               // Cached typename vector.
+	index    int                    // The index into the container, whether the file or another message.
+	path     string                 // The SourceCodeInfo path as comma-separated integers.
+	group    bool
+}
+
+// TypeName returns the elements of the dotted type name.
+// The package name is not part of this name.
+func (d *Descriptor) TypeName() []string {
+	if d.typename != nil {
+		return d.typename
+	}
+	n := 0
+	for parent := d; parent != nil; parent = parent.parent {
+		n++
+	}
+	s := make([]string, n)
+	for parent := d; parent != nil; parent = parent.parent {
+		n--
+		s[n] = parent.GetName()
+	}
+	d.typename = s
+	return s
+}
+
+// EnumDescriptor describes an enum. If it's at top level, its parent will be nil.
+// Otherwise it will be the descriptor of the message in which it is defined.
+type EnumDescriptor struct {
+	common
+	*descriptor.EnumDescriptorProto
+	parent   *Descriptor // The containing message, if any.
+	typename []string    // Cached typename vector.
+	index    int         // The index into the container, whether the file or a message.
+	path     string      // The SourceCodeInfo path as comma-separated integers.
+}
+
+// TypeName returns the elements of the dotted type name.
+// The package name is not part of this name.
+func (e *EnumDescriptor) TypeName() (s []string) {
+	if e.typename != nil {
+		return e.typename
+	}
+	name := e.GetName()
+	if e.parent == nil {
+		s = make([]string, 1)
+	} else {
+		pname := e.parent.TypeName()
+		s = make([]string, len(pname)+1)
+		copy(s, pname)
+	}
+	s[len(s)-1] = name
+	e.typename = s
+	return s
+}
+
+// Everything but the last element of the full type name, CamelCased.
+// The values of type Foo.Bar are call Foo_value1... not Foo_Bar_value1... .
+func (e *EnumDescriptor) prefix() string {
+	if e.parent == nil {
+		// If the enum is not part of a message, the prefix is just the type name.
+		return CamelCase(*e.Name) + "_"
+	}
+	typeName := e.TypeName()
+	return CamelCaseSlice(typeName[0:len(typeName)-1]) + "_"
+}
+
+// The integer value of the named constant in this enumerated type.
+func (e *EnumDescriptor) integerValueAsString(name string) string {
+	for _, c := range e.Value {
+		if c.GetName() == name {
+			return fmt.Sprint(c.GetNumber())
+		}
+	}
+	log.Fatal("cannot find value for enum constant")
+	return ""
+}
+
+// ExtensionDescriptor describes an extension. If it's at top level, its parent will be nil.
+// Otherwise it will be the descriptor of the message in which it is defined.
+type ExtensionDescriptor struct {
+	common
+	*descriptor.FieldDescriptorProto
+	parent *Descriptor // The containing message, if any.
+}
+
+// TypeName returns the elements of the dotted type name.
+// The package name is not part of this name.
+func (e *ExtensionDescriptor) TypeName() (s []string) {
+	name := e.GetName()
+	if e.parent == nil {
+		// top-level extension
+		s = make([]string, 1)
+	} else {
+		pname := e.parent.TypeName()
+		s = make([]string, len(pname)+1)
+		copy(s, pname)
+	}
+	s[len(s)-1] = name
+	return s
+}
+
+// DescName returns the variable name used for the generated descriptor.
+func (e *ExtensionDescriptor) DescName() string {
+	// The full type name.
+	typeName := e.TypeName()
+	// Each scope of the extension is individually CamelCased, and all are joined with "_" with an "E_" prefix.
+	for i, s := range typeName {
+		typeName[i] = CamelCase(s)
+	}
+	return "E_" + strings.Join(typeName, "_")
+}
+
+// ImportedDescriptor describes a type that has been publicly imported from another file.
+type ImportedDescriptor struct {
+	common
+	o Object
+}
+
+func (id *ImportedDescriptor) TypeName() []string { return id.o.TypeName() }
+
+// FileDescriptor describes an protocol buffer descriptor file (.proto).
+// It includes slices of all the messages and enums defined within it.
+// Those slices are constructed by WrapTypes.
+type FileDescriptor struct {
+	*descriptor.FileDescriptorProto
+	desc []*Descriptor          // All the messages defined in this file.
+	enum []*EnumDescriptor      // All the enums defined in this file.
+	ext  []*ExtensionDescriptor // All the top-level extensions defined in this file.
+	imp  []*ImportedDescriptor  // All types defined in files publicly imported by this file.
+
+	// Comments, stored as a map of path (comma-separated integers) to the comment.
+	comments map[string]*descriptor.SourceCodeInfo_Location
+
+	// The full list of symbols that are exported,
+	// as a map from the exported object to its symbols.
+	// This is used for supporting public imports.
+	exported map[Object][]symbol
+
+	fingerprint string        // Fingerprint of this file's contents.
+	importPath  GoImportPath  // Import path of this file's package.
+	packageName GoPackageName // Name of this file's Go package.
+
+	proto3 bool // whether to generate proto3 code for this file
+}
+
+// VarName is the variable name we'll use in the generated code to refer
+// to the compressed bytes of this descriptor. It is not exported, so
+// it is only valid inside the generated package.
+func (d *FileDescriptor) VarName() string {
+	name := strings.Map(badToUnderscore, baseName(d.GetName()))
+	return fmt.Sprintf("fileDescriptor_%s_%s", name, d.fingerprint)
+}
+
+// goPackageOption interprets the file's go_package option.
+// If there is no go_package, it returns ("", "", false).
+// If there's a simple name, it returns ("", pkg, true).
+// If the option implies an import path, it returns (impPath, pkg, true).
+func (d *FileDescriptor) goPackageOption() (impPath GoImportPath, pkg GoPackageName, ok bool) {
+	opt := d.GetOptions().GetGoPackage()
+	if opt == "" {
+		return "", "", false
+	}
+	// A semicolon-delimited suffix delimits the import path and package name.
+	sc := strings.Index(opt, ";")
+	if sc >= 0 {
+		return GoImportPath(opt[:sc]), cleanPackageName(opt[sc+1:]), true
+	}
+	// The presence of a slash implies there's an import path.
+	slash := strings.LastIndex(opt, "/")
+	if slash >= 0 {
+		return GoImportPath(opt), cleanPackageName(opt[slash+1:]), true
+	}
+	return "", cleanPackageName(opt), true
+}
+
+// goFileName returns the output name for the generated Go file.
+func (d *FileDescriptor) goFileName(pathType pathType) string {
+	name := *d.Name
+	if ext := path.Ext(name); ext == ".proto" || ext == ".protodevel" {
+		name = name[:len(name)-len(ext)]
+	}
+	name += ".pb.go"
+
+	if pathType == pathTypeSourceRelative {
+		return name
+	}
+
+	// Does the file have a "go_package" option?
+	// If it does, it may override the filename.
+	if impPath, _, ok := d.goPackageOption(); ok && impPath != "" {
+		// Replace the existing dirname with the declared import path.
+		_, name = path.Split(name)
+		name = path.Join(string(impPath), name)
+		return name
+	}
+
+	return name
+}
+
+func (d *FileDescriptor) addExport(obj Object, sym symbol) {
+	d.exported[obj] = append(d.exported[obj], sym)
+}
+
+// symbol is an interface representing an exported Go symbol.
+type symbol interface {
+	// GenerateAlias should generate an appropriate alias
+	// for the symbol from the named package.
+	GenerateAlias(g *Generator, pkg GoPackageName)
+}
+
+type messageSymbol struct {
+	sym                         string
+	hasExtensions, isMessageSet bool
+	oneofTypes                  []string
+}
+
+type getterSymbol struct {
+	name     string
+	typ      string
+	typeName string // canonical name in proto world; empty for proto.Message and similar
+	genType  bool   // whether typ contains a generated type (message/group/enum)
+}
+
+func (ms *messageSymbol) GenerateAlias(g *Generator, pkg GoPackageName) {
+	g.P("type ", ms.sym, " = ", pkg, ".", ms.sym)
+	for _, name := range ms.oneofTypes {
+		g.P("type ", name, " = ", pkg, ".", name)
+	}
+}
+
+type enumSymbol struct {
+	name   string
+	proto3 bool // Whether this came from a proto3 file.
+}
+
+func (es enumSymbol) GenerateAlias(g *Generator, pkg GoPackageName) {
+	s := es.name
+	g.P("type ", s, " = ", pkg, ".", s)
+	g.P("var ", s, "_name = ", pkg, ".", s, "_name")
+	g.P("var ", s, "_value = ", pkg, ".", s, "_value")
+}
+
+type constOrVarSymbol struct {
+	sym  string
+	typ  string // either "const" or "var"
+	cast string // if non-empty, a type cast is required (used for enums)
+}
+
+func (cs constOrVarSymbol) GenerateAlias(g *Generator, pkg GoPackageName) {
+	v := string(pkg) + "." + cs.sym
+	if cs.cast != "" {
+		v = cs.cast + "(" + v + ")"
+	}
+	g.P(cs.typ, " ", cs.sym, " = ", v)
+}
+
+// Object is an interface abstracting the abilities shared by enums, messages, extensions and imported objects.
+type Object interface {
+	GoImportPath() GoImportPath
+	TypeName() []string
+	File() *FileDescriptor
+}
+
+// Generator is the type whose methods generate the output, stored in the associated response structure.
+type Generator struct {
+	*bytes.Buffer
+
+	Request  *plugin.CodeGeneratorRequest  // The input.
+	Response *plugin.CodeGeneratorResponse // The output.
+
+	Param             map[string]string // Command-line parameters.
+	PackageImportPath string            // Go import path of the package we're generating code for
+	ImportPrefix      string            // String to prefix to imported package file names.
+	ImportMap         map[string]string // Mapping from .proto file name to import path
+
+	Pkg map[string]string // The names under which we import support packages
+
+	outputImportPath GoImportPath                   // Package we're generating code for.
+	allFiles         []*FileDescriptor              // All files in the tree
+	allFilesByName   map[string]*FileDescriptor     // All files by filename.
+	genFiles         []*FileDescriptor              // Those files we will generate output for.
+	file             *FileDescriptor                // The file we are compiling now.
+	packageNames     map[GoImportPath]GoPackageName // Imported package names in the current file.
+	usedPackages     map[GoImportPath]bool          // Packages used in current file.
+	usedPackageNames map[GoPackageName]bool         // Package names used in the current file.
+	typeNameToObject map[string]Object              // Key is a fully-qualified name in input syntax.
+	init             []string                       // Lines to emit in the init function.
+	indent           string
+	pathType         pathType // How to generate output filenames.
+	writeOutput      bool
+	annotateCode     bool                                       // whether to store annotations
+	annotations      []*descriptor.GeneratedCodeInfo_Annotation // annotations to store
+}
+
+type pathType int
+
+const (
+	pathTypeImport pathType = iota
+	pathTypeSourceRelative
+)
+
+// New creates a new generator and allocates the request and response protobufs.
+func New() *Generator {
+	g := new(Generator)
+	g.Buffer = new(bytes.Buffer)
+	g.Request = new(plugin.CodeGeneratorRequest)
+	g.Response = new(plugin.CodeGeneratorResponse)
+	return g
+}
+
+// Error reports a problem, including an error, and exits the program.
+func (g *Generator) Error(err error, msgs ...string) {
+	s := strings.Join(msgs, " ") + ":" + err.Error()
+	log.Print("protoc-gen-go: error:", s)
+	os.Exit(1)
+}
+
+// Fail reports a problem and exits the program.
+func (g *Generator) Fail(msgs ...string) {
+	s := strings.Join(msgs, " ")
+	log.Print("protoc-gen-go: error:", s)
+	os.Exit(1)
+}
+
+// CommandLineParameters breaks the comma-separated list of key=value pairs
+// in the parameter (a member of the request protobuf) into a key/value map.
+// It then sets file name mappings defined by those entries.
+func (g *Generator) CommandLineParameters(parameter string) {
+	g.Param = make(map[string]string)
+	for _, p := range strings.Split(parameter, ",") {
+		if i := strings.Index(p, "="); i < 0 {
+			g.Param[p] = ""
+		} else {
+			g.Param[p[0:i]] = p[i+1:]
+		}
+	}
+
+	g.ImportMap = make(map[string]string)
+	pluginList := "none" // Default list of plugin names to enable (empty means all).
+	for k, v := range g.Param {
+		switch k {
+		case "import_prefix":
+			g.ImportPrefix = v
+		case "import_path":
+			g.PackageImportPath = v
+		case "paths":
+			switch v {
+			case "import":
+				g.pathType = pathTypeImport
+			case "source_relative":
+				g.pathType = pathTypeSourceRelative
+			default:
+				g.Fail(fmt.Sprintf(`Unknown path type %q: want "import" or "source_relative".`, v))
+			}
+		case "plugins":
+			pluginList = v
+		case "annotate_code":
+			if v == "true" {
+				g.annotateCode = true
+			}
+		default:
+			if len(k) > 0 && k[0] == 'M' {
+				g.ImportMap[k[1:]] = v
+			}
+		}
+	}
+	if pluginList != "" {
+		// Amend the set of plugins.
+		enabled := make(map[string]bool)
+		for _, name := range strings.Split(pluginList, "+") {
+			enabled[name] = true
+		}
+		var nplugins []Plugin
+		for _, p := range plugins {
+			if enabled[p.Name()] {
+				nplugins = append(nplugins, p)
+			}
+		}
+		plugins = nplugins
+	}
+}
+
+// DefaultPackageName returns the package name printed for the object.
+// If its file is in a different package, it returns the package name we're using for this file, plus ".".
+// Otherwise it returns the empty string.
+func (g *Generator) DefaultPackageName(obj Object) string {
+	importPath := obj.GoImportPath()
+	if importPath == g.outputImportPath {
+		return ""
+	}
+	return string(g.GoPackageName(importPath)) + "."
+}
+
+// GoPackageName returns the name used for a package.
+func (g *Generator) GoPackageName(importPath GoImportPath) GoPackageName {
+	if name, ok := g.packageNames[importPath]; ok {
+		return name
+	}
+	name := cleanPackageName(baseName(string(importPath)))
+	for i, orig := 1, name; g.usedPackageNames[name]; i++ {
+		name = orig + GoPackageName(strconv.Itoa(i))
+	}
+	g.packageNames[importPath] = name
+	g.usedPackageNames[name] = true
+	return name
+}
+
+var globalPackageNames = map[GoPackageName]bool{
+	"fmt":   true,
+	"math":  true,
+	"proto": true,
+}
+
+// Create and remember a guaranteed unique package name. Pkg is the candidate name.
+// The FileDescriptor parameter is unused.
+func RegisterUniquePackageName(pkg string, f *FileDescriptor) string {
+	name := cleanPackageName(pkg)
+	for i, orig := 1, name; globalPackageNames[name]; i++ {
+		name = orig + GoPackageName(strconv.Itoa(i))
+	}
+	globalPackageNames[name] = true
+	return string(name)
+}
+
+var isGoKeyword = map[string]bool{
+	"break":       true,
+	"case":        true,
+	"chan":        true,
+	"const":       true,
+	"continue":    true,
+	"default":     true,
+	"else":        true,
+	"defer":       true,
+	"fallthrough": true,
+	"for":         true,
+	"func":        true,
+	"go":          true,
+	"goto":        true,
+	"if":          true,
+	"import":      true,
+	"interface":   true,
+	"map":         true,
+	"package":     true,
+	"range":       true,
+	"return":      true,
+	"select":      true,
+	"struct":      true,
+	"switch":      true,
+	"type":        true,
+	"var":         true,
+}
+
+func cleanPackageName(name string) GoPackageName {
+	name = strings.Map(badToUnderscore, name)
+	// Identifier must not be keyword: insert _.
+	if isGoKeyword[name] {
+		name = "_" + name
+	}
+	// Identifier must not begin with digit: insert _.
+	if r, _ := utf8.DecodeRuneInString(name); unicode.IsDigit(r) {
+		name = "_" + name
+	}
+	return GoPackageName(name)
+}
+
+// defaultGoPackage returns the package name to use,
+// derived from the import path of the package we're building code for.
+func (g *Generator) defaultGoPackage() GoPackageName {
+	p := g.PackageImportPath
+	if i := strings.LastIndex(p, "/"); i >= 0 {
+		p = p[i+1:]
+	}
+	return cleanPackageName(p)
+}
+
+// SetPackageNames sets the package name for this run.
+// The package name must agree across all files being generated.
+// It also defines unique package names for all imported files.
+func (g *Generator) SetPackageNames() {
+	g.outputImportPath = g.genFiles[0].importPath
+
+	defaultPackageNames := make(map[GoImportPath]GoPackageName)
+	for _, f := range g.genFiles {
+		if _, p, ok := f.goPackageOption(); ok {
+			defaultPackageNames[f.importPath] = p
+		}
+	}
+	for _, f := range g.genFiles {
+		if _, p, ok := f.goPackageOption(); ok {
+			// Source file: option go_package = "quux/bar";
+			f.packageName = p
+		} else if p, ok := defaultPackageNames[f.importPath]; ok {
+			// A go_package option in another file in the same package.
+			//
+			// This is a poor choice in general, since every source file should
+			// contain a go_package option. Supported mainly for historical
+			// compatibility.
+			f.packageName = p
+		} else if p := g.defaultGoPackage(); p != "" {
+			// Command-line: import_path=quux/bar.
+			//
+			// The import_path flag sets a package name for files which don't
+			// contain a go_package option.
+			f.packageName = p
+		} else if p := f.GetPackage(); p != "" {
+			// Source file: package quux.bar;
+			f.packageName = cleanPackageName(p)
+		} else {
+			// Source filename.
+			f.packageName = cleanPackageName(baseName(f.GetName()))
+		}
+	}
+
+	// Check that all files have a consistent package name and import path.
+	for _, f := range g.genFiles[1:] {
+		if a, b := g.genFiles[0].importPath, f.importPath; a != b {
+			g.Fail(fmt.Sprintf("inconsistent package import paths: %v, %v", a, b))
+		}
+		if a, b := g.genFiles[0].packageName, f.packageName; a != b {
+			g.Fail(fmt.Sprintf("inconsistent package names: %v, %v", a, b))
+		}
+	}
+
+	// Names of support packages. These never vary (if there are conflicts,
+	// we rename the conflicting package), so this could be removed someday.
+	g.Pkg = map[string]string{
+		"fmt":   "fmt",
+		"math":  "math",
+		"proto": "proto",
+	}
+}
+
+// WrapTypes walks the incoming data, wrapping DescriptorProtos, EnumDescriptorProtos
+// and FileDescriptorProtos into file-referenced objects within the Generator.
+// It also creates the list of files to generate and so should be called before GenerateAllFiles.
+func (g *Generator) WrapTypes() {
+	g.allFiles = make([]*FileDescriptor, 0, len(g.Request.ProtoFile))
+	g.allFilesByName = make(map[string]*FileDescriptor, len(g.allFiles))
+	genFileNames := make(map[string]bool)
+	for _, n := range g.Request.FileToGenerate {
+		genFileNames[n] = true
+	}
+	for _, f := range g.Request.ProtoFile {
+		fd := &FileDescriptor{
+			FileDescriptorProto: f,
+			exported:            make(map[Object][]symbol),
+			proto3:              fileIsProto3(f),
+		}
+		// The import path may be set in a number of ways.
+		if substitution, ok := g.ImportMap[f.GetName()]; ok {
+			// Command-line: M=foo.proto=quux/bar.
+			//
+			// Explicit mapping of source file to import path.
+			fd.importPath = GoImportPath(substitution)
+		} else if genFileNames[f.GetName()] && g.PackageImportPath != "" {
+			// Command-line: import_path=quux/bar.
+			//
+			// The import_path flag sets the import path for every file that
+			// we generate code for.
+			fd.importPath = GoImportPath(g.PackageImportPath)
+		} else if p, _, _ := fd.goPackageOption(); p != "" {
+			// Source file: option go_package = "quux/bar";
+			//
+			// The go_package option sets the import path. Most users should use this.
+			fd.importPath = p
+		} else {
+			// Source filename.
+			//
+			// Last resort when nothing else is available.
+			fd.importPath = GoImportPath(path.Dir(f.GetName()))
+		}
+		// We must wrap the descriptors before we wrap the enums
+		fd.desc = wrapDescriptors(fd)
+		g.buildNestedDescriptors(fd.desc)
+		fd.enum = wrapEnumDescriptors(fd, fd.desc)
+		g.buildNestedEnums(fd.desc, fd.enum)
+		fd.ext = wrapExtensions(fd)
+		extractComments(fd)
+		g.allFiles = append(g.allFiles, fd)
+		g.allFilesByName[f.GetName()] = fd
+	}
+	for _, fd := range g.allFiles {
+		fd.imp = wrapImported(fd, g)
+	}
+
+	g.genFiles = make([]*FileDescriptor, 0, len(g.Request.FileToGenerate))
+	for _, fileName := range g.Request.FileToGenerate {
+		fd := g.allFilesByName[fileName]
+		if fd == nil {
+			g.Fail("could not find file named", fileName)
+		}
+		fingerprint, err := fingerprintProto(fd.FileDescriptorProto)
+		if err != nil {
+			g.Error(err)
+		}
+		fd.fingerprint = fingerprint
+		g.genFiles = append(g.genFiles, fd)
+	}
+}
+
+// fingerprintProto returns a fingerprint for a message.
+// The fingerprint is intended to prevent conflicts between generated fileds,
+// not to provide cryptographic security.
+func fingerprintProto(m proto.Message) (string, error) {
+	b, err := proto.Marshal(m)
+	if err != nil {
+		return "", err
+	}
+	h := sha256.Sum256(b)
+	return hex.EncodeToString(h[:8]), nil
+}
+
+// Scan the descriptors in this file.  For each one, build the slice of nested descriptors
+func (g *Generator) buildNestedDescriptors(descs []*Descriptor) {
+	for _, desc := range descs {
+		if len(desc.NestedType) != 0 {
+			for _, nest := range descs {
+				if nest.parent == desc {
+					desc.nested = append(desc.nested, nest)
+				}
+			}
+			if len(desc.nested) != len(desc.NestedType) {
+				g.Fail("internal error: nesting failure for", desc.GetName())
+			}
+		}
+	}
+}
+
+func (g *Generator) buildNestedEnums(descs []*Descriptor, enums []*EnumDescriptor) {
+	for _, desc := range descs {
+		if len(desc.EnumType) != 0 {
+			for _, enum := range enums {
+				if enum.parent == desc {
+					desc.enums = append(desc.enums, enum)
+				}
+			}
+			if len(desc.enums) != len(desc.EnumType) {
+				g.Fail("internal error: enum nesting failure for", desc.GetName())
+			}
+		}
+	}
+}
+
+// Construct the Descriptor
+func newDescriptor(desc *descriptor.DescriptorProto, parent *Descriptor, file *FileDescriptor, index int) *Descriptor {
+	d := &Descriptor{
+		common:          common{file},
+		DescriptorProto: desc,
+		parent:          parent,
+		index:           index,
+	}
+	if parent == nil {
+		d.path = fmt.Sprintf("%d,%d", messagePath, index)
+	} else {
+		d.path = fmt.Sprintf("%s,%d,%d", parent.path, messageMessagePath, index)
+	}
+
+	// The only way to distinguish a group from a message is whether
+	// the containing message has a TYPE_GROUP field that matches.
+	if parent != nil {
+		parts := d.TypeName()
+		if file.Package != nil {
+			parts = append([]string{*file.Package}, parts...)
+		}
+		exp := "." + strings.Join(parts, ".")
+		for _, field := range parent.Field {
+			if field.GetType() == descriptor.FieldDescriptorProto_TYPE_GROUP && field.GetTypeName() == exp {
+				d.group = true
+				break
+			}
+		}
+	}
+
+	for _, field := range desc.Extension {
+		d.ext = append(d.ext, &ExtensionDescriptor{common{file}, field, d})
+	}
+
+	return d
+}
+
+// Return a slice of all the Descriptors defined within this file
+func wrapDescriptors(file *FileDescriptor) []*Descriptor {
+	sl := make([]*Descriptor, 0, len(file.MessageType)+10)
+	for i, desc := range file.MessageType {
+		sl = wrapThisDescriptor(sl, desc, nil, file, i)
+	}
+	return sl
+}
+
+// Wrap this Descriptor, recursively
+func wrapThisDescriptor(sl []*Descriptor, desc *descriptor.DescriptorProto, parent *Descriptor, file *FileDescriptor, index int) []*Descriptor {
+	sl = append(sl, newDescriptor(desc, parent, file, index))
+	me := sl[len(sl)-1]
+	for i, nested := range desc.NestedType {
+		sl = wrapThisDescriptor(sl, nested, me, file, i)
+	}
+	return sl
+}
+
+// Construct the EnumDescriptor
+func newEnumDescriptor(desc *descriptor.EnumDescriptorProto, parent *Descriptor, file *FileDescriptor, index int) *EnumDescriptor {
+	ed := &EnumDescriptor{
+		common:              common{file},
+		EnumDescriptorProto: desc,
+		parent:              parent,
+		index:               index,
+	}
+	if parent == nil {
+		ed.path = fmt.Sprintf("%d,%d", enumPath, index)
+	} else {
+		ed.path = fmt.Sprintf("%s,%d,%d", parent.path, messageEnumPath, index)
+	}
+	return ed
+}
+
+// Return a slice of all the EnumDescriptors defined within this file
+func wrapEnumDescriptors(file *FileDescriptor, descs []*Descriptor) []*EnumDescriptor {
+	sl := make([]*EnumDescriptor, 0, len(file.EnumType)+10)
+	// Top-level enums.
+	for i, enum := range file.EnumType {
+		sl = append(sl, newEnumDescriptor(enum, nil, file, i))
+	}
+	// Enums within messages. Enums within embedded messages appear in the outer-most message.
+	for _, nested := range descs {
+		for i, enum := range nested.EnumType {
+			sl = append(sl, newEnumDescriptor(enum, nested, file, i))
+		}
+	}
+	return sl
+}
+
+// Return a slice of all the top-level ExtensionDescriptors defined within this file.
+func wrapExtensions(file *FileDescriptor) []*ExtensionDescriptor {
+	var sl []*ExtensionDescriptor
+	for _, field := range file.Extension {
+		sl = append(sl, &ExtensionDescriptor{common{file}, field, nil})
+	}
+	return sl
+}
+
+// Return a slice of all the types that are publicly imported into this file.
+func wrapImported(file *FileDescriptor, g *Generator) (sl []*ImportedDescriptor) {
+	for _, index := range file.PublicDependency {
+		df := g.fileByName(file.Dependency[index])
+		for _, d := range df.desc {
+			if d.GetOptions().GetMapEntry() {
+				continue
+			}
+			sl = append(sl, &ImportedDescriptor{common{file}, d})
+		}
+		for _, e := range df.enum {
+			sl = append(sl, &ImportedDescriptor{common{file}, e})
+		}
+		for _, ext := range df.ext {
+			sl = append(sl, &ImportedDescriptor{common{file}, ext})
+		}
+	}
+	return
+}
+
+func extractComments(file *FileDescriptor) {
+	file.comments = make(map[string]*descriptor.SourceCodeInfo_Location)
+	for _, loc := range file.GetSourceCodeInfo().GetLocation() {
+		if loc.LeadingComments == nil {
+			continue
+		}
+		var p []string
+		for _, n := range loc.Path {
+			p = append(p, strconv.Itoa(int(n)))
+		}
+		file.comments[strings.Join(p, ",")] = loc
+	}
+}
+
+// BuildTypeNameMap builds the map from fully qualified type names to objects.
+// The key names for the map come from the input data, which puts a period at the beginning.
+// It should be called after SetPackageNames and before GenerateAllFiles.
+func (g *Generator) BuildTypeNameMap() {
+	g.typeNameToObject = make(map[string]Object)
+	for _, f := range g.allFiles {
+		// The names in this loop are defined by the proto world, not us, so the
+		// package name may be empty.  If so, the dotted package name of X will
+		// be ".X"; otherwise it will be ".pkg.X".
+		dottedPkg := "." + f.GetPackage()
+		if dottedPkg != "." {
+			dottedPkg += "."
+		}
+		for _, enum := range f.enum {
+			name := dottedPkg + dottedSlice(enum.TypeName())
+			g.typeNameToObject[name] = enum
+		}
+		for _, desc := range f.desc {
+			name := dottedPkg + dottedSlice(desc.TypeName())
+			g.typeNameToObject[name] = desc
+		}
+	}
+}
+
+// ObjectNamed, given a fully-qualified input type name as it appears in the input data,
+// returns the descriptor for the message or enum with that name.
+func (g *Generator) ObjectNamed(typeName string) Object {
+	o, ok := g.typeNameToObject[typeName]
+	if !ok {
+		g.Fail("can't find object with type", typeName)
+	}
+
+	// If the file of this object isn't a direct dependency of the current file,
+	// or in the current file, then this object has been publicly imported into
+	// a dependency of the current file.
+	// We should return the ImportedDescriptor object for it instead.
+	direct := *o.File().Name == *g.file.Name
+	if !direct {
+		for _, dep := range g.file.Dependency {
+			if *g.fileByName(dep).Name == *o.File().Name {
+				direct = true
+				break
+			}
+		}
+	}
+	if !direct {
+		found := false
+	Loop:
+		for _, dep := range g.file.Dependency {
+			df := g.fileByName(*g.fileByName(dep).Name)
+			for _, td := range df.imp {
+				if td.o == o {
+					// Found it!
+					o = td
+					found = true
+					break Loop
+				}
+			}
+		}
+		if !found {
+			log.Printf("protoc-gen-go: WARNING: failed finding publicly imported dependency for %v, used in %v", typeName, *g.file.Name)
+		}
+	}
+
+	return o
+}
+
+// AnnotatedAtoms is a list of atoms (as consumed by P) that records the file name and proto AST path from which they originated.
+type AnnotatedAtoms struct {
+	source string
+	path   string
+	atoms  []interface{}
+}
+
+// Annotate records the file name and proto AST path of a list of atoms
+// so that a later call to P can emit a link from each atom to its origin.
+func Annotate(file *FileDescriptor, path string, atoms ...interface{}) *AnnotatedAtoms {
+	return &AnnotatedAtoms{source: *file.Name, path: path, atoms: atoms}
+}
+
+// printAtom prints the (atomic, non-annotation) argument to the generated output.
+func (g *Generator) printAtom(v interface{}) {
+	switch v := v.(type) {
+	case string:
+		g.WriteString(v)
+	case *string:
+		g.WriteString(*v)
+	case bool:
+		fmt.Fprint(g, v)
+	case *bool:
+		fmt.Fprint(g, *v)
+	case int:
+		fmt.Fprint(g, v)
+	case *int32:
+		fmt.Fprint(g, *v)
+	case *int64:
+		fmt.Fprint(g, *v)
+	case float64:
+		fmt.Fprint(g, v)
+	case *float64:
+		fmt.Fprint(g, *v)
+	case GoPackageName:
+		g.WriteString(string(v))
+	case GoImportPath:
+		g.WriteString(strconv.Quote(string(v)))
+	default:
+		g.Fail(fmt.Sprintf("unknown type in printer: %T", v))
+	}
+}
+
+// P prints the arguments to the generated output.  It handles strings and int32s, plus
+// handling indirections because they may be *string, etc.  Any inputs of type AnnotatedAtoms may emit
+// annotations in a .meta file in addition to outputting the atoms themselves (if g.annotateCode
+// is true).
+func (g *Generator) P(str ...interface{}) {
+	if !g.writeOutput {
+		return
+	}
+	g.WriteString(g.indent)
+	for _, v := range str {
+		switch v := v.(type) {
+		case *AnnotatedAtoms:
+			begin := int32(g.Len())
+			for _, v := range v.atoms {
+				g.printAtom(v)
+			}
+			if g.annotateCode {
+				end := int32(g.Len())
+				var path []int32
+				for _, token := range strings.Split(v.path, ",") {
+					val, err := strconv.ParseInt(token, 10, 32)
+					if err != nil {
+						g.Fail("could not parse proto AST path: ", err.Error())
+					}
+					path = append(path, int32(val))
+				}
+				g.annotations = append(g.annotations, &descriptor.GeneratedCodeInfo_Annotation{
+					Path:       path,
+					SourceFile: &v.source,
+					Begin:      &begin,
+					End:        &end,
+				})
+			}
+		default:
+			g.printAtom(v)
+		}
+	}
+	g.WriteByte('\n')
+}
+
+// addInitf stores the given statement to be printed inside the file's init function.
+// The statement is given as a format specifier and arguments.
+func (g *Generator) addInitf(stmt string, a ...interface{}) {
+	g.init = append(g.init, fmt.Sprintf(stmt, a...))
+}
+
+// In Indents the output one tab stop.
+func (g *Generator) In() { g.indent += "\t" }
+
+// Out unindents the output one tab stop.
+func (g *Generator) Out() {
+	if len(g.indent) > 0 {
+		g.indent = g.indent[1:]
+	}
+}
+
+// GenerateAllFiles generates the output for all the files we're outputting.
+func (g *Generator) GenerateAllFiles() {
+	// Initialize the plugins
+	for _, p := range plugins {
+		p.Init(g)
+	}
+	// Generate the output. The generator runs for every file, even the files
+	// that we don't generate output for, so that we can collate the full list
+	// of exported symbols to support public imports.
+	genFileMap := make(map[*FileDescriptor]bool, len(g.genFiles))
+	for _, file := range g.genFiles {
+		genFileMap[file] = true
+	}
+	for _, file := range g.allFiles {
+		g.Reset()
+		g.annotations = nil
+		g.writeOutput = genFileMap[file]
+		g.generate(file)
+		if !g.writeOutput {
+			continue
+		}
+		fname := file.goFileName(g.pathType)
+		g.Response.File = append(g.Response.File, &plugin.CodeGeneratorResponse_File{
+			Name:    proto.String(fname),
+			Content: proto.String(g.String()),
+		})
+		if g.annotateCode {
+			// Store the generated code annotations in text, as the protoc plugin protocol requires that
+			// strings contain valid UTF-8.
+			g.Response.File = append(g.Response.File, &plugin.CodeGeneratorResponse_File{
+				Name:    proto.String(file.goFileName(g.pathType) + ".meta"),
+				Content: proto.String(proto.CompactTextString(&descriptor.GeneratedCodeInfo{Annotation: g.annotations})),
+			})
+		}
+	}
+}
+
+// Run all the plugins associated with the file.
+func (g *Generator) runPlugins(file *FileDescriptor) {
+	for _, p := range plugins {
+		p.Generate(file)
+	}
+}
+
+// Fill the response protocol buffer with the generated output for all the files we're
+// supposed to generate.
+func (g *Generator) generate(file *FileDescriptor) {
+	g.file = file
+	g.usedPackages = make(map[GoImportPath]bool)
+	g.packageNames = make(map[GoImportPath]GoPackageName)
+	g.usedPackageNames = make(map[GoPackageName]bool)
+	for name := range globalPackageNames {
+		g.usedPackageNames[name] = true
+	}
+
+	g.P("// This is a compile-time assertion to ensure that this generated file")
+	g.P("// is compatible with the proto package it is being compiled against.")
+	g.P("// A compilation error at this line likely means your copy of the")
+	g.P("// proto package needs to be updated.")
+	g.P("const _ = ", g.Pkg["proto"], ".ProtoPackageIsVersion", generatedCodeVersion, " // please upgrade the proto package")
+	g.P()
+
+	for _, td := range g.file.imp {
+		g.generateImported(td)
+	}
+	for _, enum := range g.file.enum {
+		g.generateEnum(enum)
+	}
+	for _, desc := range g.file.desc {
+		// Don't generate virtual messages for maps.
+		if desc.GetOptions().GetMapEntry() {
+			continue
+		}
+		g.generateMessage(desc)
+	}
+	for _, ext := range g.file.ext {
+		g.generateExtension(ext)
+	}
+	g.generateInitFunction()
+
+	// Run the plugins before the imports so we know which imports are necessary.
+	g.runPlugins(file)
+
+	g.generateFileDescriptor(file)
+
+	// Generate header and imports last, though they appear first in the output.
+	rem := g.Buffer
+	remAnno := g.annotations
+	g.Buffer = new(bytes.Buffer)
+	g.annotations = nil
+	g.generateHeader()
+	g.generateImports()
+	if !g.writeOutput {
+		return
+	}
+	// Adjust the offsets for annotations displaced by the header and imports.
+	for _, anno := range remAnno {
+		*anno.Begin += int32(g.Len())
+		*anno.End += int32(g.Len())
+		g.annotations = append(g.annotations, anno)
+	}
+	g.Write(rem.Bytes())
+
+	// Reformat generated code and patch annotation locations.
+	fset := token.NewFileSet()
+	original := g.Bytes()
+	if g.annotateCode {
+		// make a copy independent of g; we'll need it after Reset.
+		original = append([]byte(nil), original...)
+	}
+	ast, err := parser.ParseFile(fset, "", original, parser.ParseComments)
+	if err != nil {
+		// Print out the bad code with line numbers.
+		// This should never happen in practice, but it can while changing generated code,
+		// so consider this a debugging aid.
+		var src bytes.Buffer
+		s := bufio.NewScanner(bytes.NewReader(original))
+		for line := 1; s.Scan(); line++ {
+			fmt.Fprintf(&src, "%5d\t%s\n", line, s.Bytes())
+		}
+		g.Fail("bad Go source code was generated:", err.Error(), "\n"+src.String())
+	}
+	g.Reset()
+	err = (&printer.Config{Mode: printer.TabIndent | printer.UseSpaces, Tabwidth: 8}).Fprint(g, fset, ast)
+	if err != nil {
+		g.Fail("generated Go source code could not be reformatted:", err.Error())
+	}
+	if g.annotateCode {
+		m, err := remap.Compute(original, g.Bytes())
+		if err != nil {
+			g.Fail("formatted generated Go source code could not be mapped back to the original code:", err.Error())
+		}
+		for _, anno := range g.annotations {
+			new, ok := m.Find(int(*anno.Begin), int(*anno.End))
+			if !ok {
+				g.Fail("span in formatted generated Go source code could not be mapped back to the original code")
+			}
+			*anno.Begin = int32(new.Pos)
+			*anno.End = int32(new.End)
+		}
+	}
+}
+
+// Generate the header, including package definition
+func (g *Generator) generateHeader() {
+	g.P("// Code generated by protoc-gen-go. DO NOT EDIT.")
+	if g.file.GetOptions().GetDeprecated() {
+		g.P("// ", g.file.Name, " is a deprecated file.")
+	} else {
+		g.P("// source: ", g.file.Name)
+	}
+	g.P()
+
+	importPath, _, _ := g.file.goPackageOption()
+	if importPath == "" {
+		g.P("package ", g.file.packageName)
+	} else {
+		g.P("package ", g.file.packageName, " // import ", GoImportPath(g.ImportPrefix)+importPath)
+	}
+	g.P()
+
+	if loc, ok := g.file.comments[strconv.Itoa(packagePath)]; ok {
+		g.P("/*")
+		// not using g.PrintComments because this is a /* */ comment block.
+		text := strings.TrimSuffix(loc.GetLeadingComments(), "\n")
+		for _, line := range strings.Split(text, "\n") {
+			line = strings.TrimPrefix(line, " ")
+			// ensure we don't escape from the block comment
+			line = strings.Replace(line, "*/", "* /", -1)
+			g.P(line)
+		}
+		g.P("*/")
+		g.P()
+	}
+}
+
+// deprecationComment is the standard comment added to deprecated
+// messages, fields, enums, and enum values.
+var deprecationComment = "// Deprecated: Do not use."
+
+// PrintComments prints any comments from the source .proto file.
+// The path is a comma-separated list of integers.
+// It returns an indication of whether any comments were printed.
+// See descriptor.proto for its format.
+func (g *Generator) PrintComments(path string) bool {
+	if !g.writeOutput {
+		return false
+	}
+	if c, ok := g.makeComments(path); ok {
+		g.P(c)
+		return true
+	}
+	return false
+}
+
+// makeComments generates the comment string for the field, no "\n" at the end
+func (g *Generator) makeComments(path string) (string, bool) {
+	loc, ok := g.file.comments[path]
+	if !ok {
+		return "", false
+	}
+	w := new(bytes.Buffer)
+	nl := ""
+	for _, line := range strings.Split(strings.TrimSuffix(loc.GetLeadingComments(), "\n"), "\n") {
+		fmt.Fprintf(w, "%s// %s", nl, strings.TrimPrefix(line, " "))
+		nl = "\n"
+	}
+	return w.String(), true
+}
+
+func (g *Generator) fileByName(filename string) *FileDescriptor {
+	return g.allFilesByName[filename]
+}
+
+// weak returns whether the ith import of the current file is a weak import.
+func (g *Generator) weak(i int32) bool {
+	for _, j := range g.file.WeakDependency {
+		if j == i {
+			return true
+		}
+	}
+	return false
+}
+
+// Generate the imports
+func (g *Generator) generateImports() {
+	// We almost always need a proto import.  Rather than computing when we
+	// do, which is tricky when there's a plugin, just import it and
+	// reference it later. The same argument applies to the fmt and math packages.
+	g.P("import "+g.Pkg["proto"]+" ", GoImportPath(g.ImportPrefix)+"github.com/golang/protobuf/proto")
+	g.P("import " + g.Pkg["fmt"] + ` "fmt"`)
+	g.P("import " + g.Pkg["math"] + ` "math"`)
+	var (
+		imports       = make(map[GoImportPath]bool)
+		strongImports = make(map[GoImportPath]bool)
+		importPaths   []string
+	)
+	for i, s := range g.file.Dependency {
+		fd := g.fileByName(s)
+		importPath := fd.importPath
+		// Do not import our own package.
+		if importPath == g.file.importPath {
+			continue
+		}
+		if !imports[importPath] {
+			importPaths = append(importPaths, string(importPath))
+		}
+		imports[importPath] = true
+		if !g.weak(int32(i)) {
+			strongImports[importPath] = true
+		}
+	}
+	sort.Strings(importPaths)
+	for i := range importPaths {
+		importPath := GoImportPath(importPaths[i])
+		packageName := g.GoPackageName(importPath)
+		fullPath := GoImportPath(g.ImportPrefix) + importPath
+		// Skip weak imports.
+		if !strongImports[importPath] {
+			g.P("// skipping weak import ", packageName, " ", fullPath)
+			continue
+		}
+		// We need to import all the dependencies, even if we don't reference them,
+		// because other code and tools depend on having the full transitive closure
+		// of protocol buffer types in the binary.
+		if _, ok := g.usedPackages[importPath]; !ok {
+			packageName = "_"
+		}
+		g.P("import ", packageName, " ", fullPath)
+	}
+	g.P()
+	// TODO: may need to worry about uniqueness across plugins
+	for _, p := range plugins {
+		p.GenerateImports(g.file)
+		g.P()
+	}
+	g.P("// Reference imports to suppress errors if they are not otherwise used.")
+	g.P("var _ = ", g.Pkg["proto"], ".Marshal")
+	g.P("var _ = ", g.Pkg["fmt"], ".Errorf")
+	g.P("var _ = ", g.Pkg["math"], ".Inf")
+	g.P()
+}
+
+func (g *Generator) generateImported(id *ImportedDescriptor) {
+	tn := id.TypeName()
+	sn := tn[len(tn)-1]
+	df := id.o.File()
+	filename := *df.Name
+	if df.importPath == g.file.importPath {
+		// Don't generate type aliases for files in the same Go package as this one.
+		g.P("// Ignoring public import of ", sn, " from ", filename)
+		g.P()
+		return
+	}
+	if !supportTypeAliases {
+		g.Fail(fmt.Sprintf("%s: public imports require at least go1.9", filename))
+	}
+	g.P("// ", sn, " from public import ", filename)
+	g.usedPackages[df.importPath] = true
+
+	for _, sym := range df.exported[id.o] {
+		sym.GenerateAlias(g, g.GoPackageName(df.importPath))
+	}
+
+	g.P()
+}
+
+// Generate the enum definitions for this EnumDescriptor.
+func (g *Generator) generateEnum(enum *EnumDescriptor) {
+	// The full type name
+	typeName := enum.TypeName()
+	// The full type name, CamelCased.
+	ccTypeName := CamelCaseSlice(typeName)
+	ccPrefix := enum.prefix()
+
+	deprecatedEnum := ""
+	if enum.GetOptions().GetDeprecated() {
+		deprecatedEnum = deprecationComment
+	}
+	g.PrintComments(enum.path)
+	g.P("type ", Annotate(enum.file, enum.path, ccTypeName), " int32", deprecatedEnum)
+	g.file.addExport(enum, enumSymbol{ccTypeName, enum.proto3()})
+	g.P("const (")
+	for i, e := range enum.Value {
+		etorPath := fmt.Sprintf("%s,%d,%d", enum.path, enumValuePath, i)
+		g.PrintComments(etorPath)
+
+		deprecatedValue := ""
+		if e.GetOptions().GetDeprecated() {
+			deprecatedValue = deprecationComment
+		}
+
+		name := ccPrefix + *e.Name
+		g.P(Annotate(enum.file, etorPath, name), " ", ccTypeName, " = ", e.Number, " ", deprecatedValue)
+		g.file.addExport(enum, constOrVarSymbol{name, "const", ccTypeName})
+	}
+	g.P(")")
+	g.P("var ", ccTypeName, "_name = map[int32]string{")
+	generated := make(map[int32]bool) // avoid duplicate values
+	for _, e := range enum.Value {
+		duplicate := ""
+		if _, present := generated[*e.Number]; present {
+			duplicate = "// Duplicate value: "
+		}
+		g.P(duplicate, e.Number, ": ", strconv.Quote(*e.Name), ",")
+		generated[*e.Number] = true
+	}
+	g.P("}")
+	g.P("var ", ccTypeName, "_value = map[string]int32{")
+	for _, e := range enum.Value {
+		g.P(strconv.Quote(*e.Name), ": ", e.Number, ",")
+	}
+	g.P("}")
+
+	if !enum.proto3() {
+		g.P("func (x ", ccTypeName, ") Enum() *", ccTypeName, " {")
+		g.P("p := new(", ccTypeName, ")")
+		g.P("*p = x")
+		g.P("return p")
+		g.P("}")
+	}
+
+	g.P("func (x ", ccTypeName, ") String() string {")
+	g.P("return ", g.Pkg["proto"], ".EnumName(", ccTypeName, "_name, int32(x))")
+	g.P("}")
+
+	if !enum.proto3() {
+		g.P("func (x *", ccTypeName, ") UnmarshalJSON(data []byte) error {")
+		g.P("value, err := ", g.Pkg["proto"], ".UnmarshalJSONEnum(", ccTypeName, `_value, data, "`, ccTypeName, `")`)
+		g.P("if err != nil {")
+		g.P("return err")
+		g.P("}")
+		g.P("*x = ", ccTypeName, "(value)")
+		g.P("return nil")
+		g.P("}")
+	}
+
+	var indexes []string
+	for m := enum.parent; m != nil; m = m.parent {
+		// XXX: skip groups?
+		indexes = append([]string{strconv.Itoa(m.index)}, indexes...)
+	}
+	indexes = append(indexes, strconv.Itoa(enum.index))
+	g.P("func (", ccTypeName, ") EnumDescriptor() ([]byte, []int) {")
+	g.P("return ", g.file.VarName(), ", []int{", strings.Join(indexes, ", "), "}")
+	g.P("}")
+	if enum.file.GetPackage() == "google.protobuf" && enum.GetName() == "NullValue" {
+		g.P("func (", ccTypeName, `) XXX_WellKnownType() string { return "`, enum.GetName(), `" }`)
+	}
+
+	g.P()
+}
+
+// The tag is a string like "varint,2,opt,name=fieldname,def=7" that
+// identifies details of the field for the protocol buffer marshaling and unmarshaling
+// code.  The fields are:
+//	wire encoding
+//	protocol tag number
+//	opt,req,rep for optional, required, or repeated
+//	packed whether the encoding is "packed" (optional; repeated primitives only)
+//	name= the original declared name
+//	enum= the name of the enum type if it is an enum-typed field.
+//	proto3 if this field is in a proto3 message
+//	def= string representation of the default value, if any.
+// The default value must be in a representation that can be used at run-time
+// to generate the default value. Thus bools become 0 and 1, for instance.
+func (g *Generator) goTag(message *Descriptor, field *descriptor.FieldDescriptorProto, wiretype string) string {
+	optrepreq := ""
+	switch {
+	case isOptional(field):
+		optrepreq = "opt"
+	case isRequired(field):
+		optrepreq = "req"
+	case isRepeated(field):
+		optrepreq = "rep"
+	}
+	var defaultValue string
+	if dv := field.DefaultValue; dv != nil { // set means an explicit default
+		defaultValue = *dv
+		// Some types need tweaking.
+		switch *field.Type {
+		case descriptor.FieldDescriptorProto_TYPE_BOOL:
+			if defaultValue == "true" {
+				defaultValue = "1"
+			} else {
+				defaultValue = "0"
+			}
+		case descriptor.FieldDescriptorProto_TYPE_STRING,
+			descriptor.FieldDescriptorProto_TYPE_BYTES:
+			// Nothing to do. Quoting is done for the whole tag.
+		case descriptor.FieldDescriptorProto_TYPE_ENUM:
+			// For enums we need to provide the integer constant.
+			obj := g.ObjectNamed(field.GetTypeName())
+			if id, ok := obj.(*ImportedDescriptor); ok {
+				// It is an enum that was publicly imported.
+				// We need the underlying type.
+				obj = id.o
+			}
+			enum, ok := obj.(*EnumDescriptor)
+			if !ok {
+				log.Printf("obj is a %T", obj)
+				if id, ok := obj.(*ImportedDescriptor); ok {
+					log.Printf("id.o is a %T", id.o)
+				}
+				g.Fail("unknown enum type", CamelCaseSlice(obj.TypeName()))
+			}
+			defaultValue = enum.integerValueAsString(defaultValue)
+		}
+		defaultValue = ",def=" + defaultValue
+	}
+	enum := ""
+	if *field.Type == descriptor.FieldDescriptorProto_TYPE_ENUM {
+		// We avoid using obj.GoPackageName(), because we want to use the
+		// original (proto-world) package name.
+		obj := g.ObjectNamed(field.GetTypeName())
+		if id, ok := obj.(*ImportedDescriptor); ok {
+			obj = id.o
+		}
+		enum = ",enum="
+		if pkg := obj.File().GetPackage(); pkg != "" {
+			enum += pkg + "."
+		}
+		enum += CamelCaseSlice(obj.TypeName())
+	}
+	packed := ""
+	if (field.Options != nil && field.Options.GetPacked()) ||
+		// Per https://developers.google.com/protocol-buffers/docs/proto3#simple:
+		// "In proto3, repeated fields of scalar numeric types use packed encoding by default."
+		(message.proto3() && (field.Options == nil || field.Options.Packed == nil) &&
+			isRepeated(field) && isScalar(field)) {
+		packed = ",packed"
+	}
+	fieldName := field.GetName()
+	name := fieldName
+	if *field.Type == descriptor.FieldDescriptorProto_TYPE_GROUP {
+		// We must use the type name for groups instead of
+		// the field name to preserve capitalization.
+		// type_name in FieldDescriptorProto is fully-qualified,
+		// but we only want the local part.
+		name = *field.TypeName
+		if i := strings.LastIndex(name, "."); i >= 0 {
+			name = name[i+1:]
+		}
+	}
+	if json := field.GetJsonName(); json != "" && json != name {
+		// TODO: escaping might be needed, in which case
+		// perhaps this should be in its own "json" tag.
+		name += ",json=" + json
+	}
+	name = ",name=" + name
+	if message.proto3() {
+		name += ",proto3"
+	}
+	oneof := ""
+	if field.OneofIndex != nil {
+		oneof = ",oneof"
+	}
+	return strconv.Quote(fmt.Sprintf("%s,%d,%s%s%s%s%s%s",
+		wiretype,
+		field.GetNumber(),
+		optrepreq,
+		packed,
+		name,
+		enum,
+		oneof,
+		defaultValue))
+}
+
+func needsStar(typ descriptor.FieldDescriptorProto_Type) bool {
+	switch typ {
+	case descriptor.FieldDescriptorProto_TYPE_GROUP:
+		return false
+	case descriptor.FieldDescriptorProto_TYPE_MESSAGE:
+		return false
+	case descriptor.FieldDescriptorProto_TYPE_BYTES:
+		return false
+	}
+	return true
+}
+
+// TypeName is the printed name appropriate for an item. If the object is in the current file,
+// TypeName drops the package name and underscores the rest.
+// Otherwise the object is from another package; and the result is the underscored
+// package name followed by the item name.
+// The result always has an initial capital.
+func (g *Generator) TypeName(obj Object) string {
+	return g.DefaultPackageName(obj) + CamelCaseSlice(obj.TypeName())
+}
+
+// GoType returns a string representing the type name, and the wire type
+func (g *Generator) GoType(message *Descriptor, field *descriptor.FieldDescriptorProto) (typ string, wire string) {
+	// TODO: Options.
+	switch *field.Type {
+	case descriptor.FieldDescriptorProto_TYPE_DOUBLE:
+		typ, wire = "float64", "fixed64"
+	case descriptor.FieldDescriptorProto_TYPE_FLOAT:
+		typ, wire = "float32", "fixed32"
+	case descriptor.FieldDescriptorProto_TYPE_INT64:
+		typ, wire = "int64", "varint"
+	case descriptor.FieldDescriptorProto_TYPE_UINT64:
+		typ, wire = "uint64", "varint"
+	case descriptor.FieldDescriptorProto_TYPE_INT32:
+		typ, wire = "int32", "varint"
+	case descriptor.FieldDescriptorProto_TYPE_UINT32:
+		typ, wire = "uint32", "varint"
+	case descriptor.FieldDescriptorProto_TYPE_FIXED64:
+		typ, wire = "uint64", "fixed64"
+	case descriptor.FieldDescriptorProto_TYPE_FIXED32:
+		typ, wire = "uint32", "fixed32"
+	case descriptor.FieldDescriptorProto_TYPE_BOOL:
+		typ, wire = "bool", "varint"
+	case descriptor.FieldDescriptorProto_TYPE_STRING:
+		typ, wire = "string", "bytes"
+	case descriptor.FieldDescriptorProto_TYPE_GROUP:
+		desc := g.ObjectNamed(field.GetTypeName())
+		typ, wire = "*"+g.TypeName(desc), "group"
+	case descriptor.FieldDescriptorProto_TYPE_MESSAGE:
+		desc := g.ObjectNamed(field.GetTypeName())
+		typ, wire = "*"+g.TypeName(desc), "bytes"
+	case descriptor.FieldDescriptorProto_TYPE_BYTES:
+		typ, wire = "[]byte", "bytes"
+	case descriptor.FieldDescriptorProto_TYPE_ENUM:
+		desc := g.ObjectNamed(field.GetTypeName())
+		typ, wire = g.TypeName(desc), "varint"
+	case descriptor.FieldDescriptorProto_TYPE_SFIXED32:
+		typ, wire = "int32", "fixed32"
+	case descriptor.FieldDescriptorProto_TYPE_SFIXED64:
+		typ, wire = "int64", "fixed64"
+	case descriptor.FieldDescriptorProto_TYPE_SINT32:
+		typ, wire = "int32", "zigzag32"
+	case descriptor.FieldDescriptorProto_TYPE_SINT64:
+		typ, wire = "int64", "zigzag64"
+	default:
+		g.Fail("unknown type for", field.GetName())
+	}
+	if isRepeated(field) {
+		typ = "[]" + typ
+	} else if message != nil && message.proto3() {
+		return
+	} else if field.OneofIndex != nil && message != nil {
+		return
+	} else if needsStar(*field.Type) {
+		typ = "*" + typ
+	}
+	return
+}
+
+func (g *Generator) RecordTypeUse(t string) {
+	if _, ok := g.typeNameToObject[t]; ok {
+		// Call ObjectNamed to get the true object to record the use.
+		obj := g.ObjectNamed(t)
+		g.usedPackages[obj.GoImportPath()] = true
+	}
+}
+
+// Method names that may be generated.  Fields with these names get an
+// underscore appended. Any change to this set is a potential incompatible
+// API change because it changes generated field names.
+var methodNames = [...]string{
+	"Reset",
+	"String",
+	"ProtoMessage",
+	"Marshal",
+	"Unmarshal",
+	"ExtensionRangeArray",
+	"ExtensionMap",
+	"Descriptor",
+}
+
+// Names of messages in the `google.protobuf` package for which
+// we will generate XXX_WellKnownType methods.
+var wellKnownTypes = map[string]bool{
+	"Any":       true,
+	"Duration":  true,
+	"Empty":     true,
+	"Struct":    true,
+	"Timestamp": true,
+
+	"Value":       true,
+	"ListValue":   true,
+	"DoubleValue": true,
+	"FloatValue":  true,
+	"Int64Value":  true,
+	"UInt64Value": true,
+	"Int32Value":  true,
+	"UInt32Value": true,
+	"BoolValue":   true,
+	"StringValue": true,
+	"BytesValue":  true,
+}
+
+// getterDefault finds the default value for the field to return from a getter,
+// regardless of if it's a built in default or explicit from the source. Returns e.g. "nil", `""`, "Default_MessageType_FieldName"
+func (g *Generator) getterDefault(field *descriptor.FieldDescriptorProto, goMessageType string) string {
+	if isRepeated(field) {
+		return "nil"
+	}
+	if def := field.GetDefaultValue(); def != "" {
+		defaultConstant := g.defaultConstantName(goMessageType, field.GetName())
+		if *field.Type != descriptor.FieldDescriptorProto_TYPE_BYTES {
+			return defaultConstant
+		}
+		return "append([]byte(nil), " + defaultConstant + "...)"
+	}
+	switch *field.Type {
+	case descriptor.FieldDescriptorProto_TYPE_BOOL:
+		return "false"
+	case descriptor.FieldDescriptorProto_TYPE_STRING:
+		return `""`
+	case descriptor.FieldDescriptorProto_TYPE_GROUP, descriptor.FieldDescriptorProto_TYPE_MESSAGE, descriptor.FieldDescriptorProto_TYPE_BYTES:
+		return "nil"
+	case descriptor.FieldDescriptorProto_TYPE_ENUM:
+		obj := g.ObjectNamed(field.GetTypeName())
+		var enum *EnumDescriptor
+		if id, ok := obj.(*ImportedDescriptor); ok {
+			// The enum type has been publicly imported.
+			enum, _ = id.o.(*EnumDescriptor)
+		} else {
+			enum, _ = obj.(*EnumDescriptor)
+		}
+		if enum == nil {
+			log.Printf("don't know how to generate getter for %s", field.GetName())
+			return "nil"
+		}
+		if len(enum.Value) == 0 {
+			return "0 // empty enum"
+		}
+		first := enum.Value[0].GetName()
+		return g.DefaultPackageName(obj) + enum.prefix() + first
+	default:
+		return "0"
+	}
+}
+
+// defaultConstantName builds the name of the default constant from the message
+// type name and the untouched field name, e.g. "Default_MessageType_FieldName"
+func (g *Generator) defaultConstantName(goMessageType, protoFieldName string) string {
+	return "Default_" + goMessageType + "_" + CamelCase(protoFieldName)
+}
+
+// The different types of fields in a message and how to actually print them
+// Most of the logic for generateMessage is in the methods of these types.
+//
+// Note that the content of the field is irrelevant, a simpleField can contain
+// anything from a scalar to a group (which is just a message).
+//
+// Extension fields (and message sets) are however handled separately.
+//
+// simpleField - a field that is neiter weak nor oneof, possibly repeated
+// oneofField - field containing list of subfields:
+// - oneofSubField - a field within the oneof
+
+// msgCtx contais the context for the generator functions.
+type msgCtx struct {
+	goName  string      // Go struct name of the message, e.g. MessageName
+	message *Descriptor // The descriptor for the message
+}
+
+// fieldCommon contains data common to all types of fields.
+type fieldCommon struct {
+	goName     string // Go name of field, e.g. "FieldName" or "Descriptor_"
+	protoName  string // Name of field in proto language, e.g. "field_name" or "descriptor"
+	getterName string // Name of the getter, e.g. "GetFieldName" or "GetDescriptor_"
+	goType     string // The Go type as a string, e.g. "*int32" or "*OtherMessage"
+	tags       string // The tag string/annotation for the type, e.g. `protobuf:"varint,8,opt,name=region_id,json=regionId"`
+	fullPath   string // The full path of the field as used by Annotate etc, e.g. "4,0,2,0"
+}
+
+// getProtoName gets the proto name of a field, e.g. "field_name" or "descriptor".
+func (f *fieldCommon) getProtoName() string {
+	return f.protoName
+}
+
+// getGoType returns the go type of the field  as a string, e.g. "*int32".
+func (f *fieldCommon) getGoType() string {
+	return f.goType
+}
+
+// simpleField is not weak, not a oneof, not an extension. Can be required, optional or repeated.
+type simpleField struct {
+	fieldCommon
+	protoTypeName string                               // Proto type name, empty if primitive, e.g. ".google.protobuf.Duration"
+	protoType     descriptor.FieldDescriptorProto_Type // Actual type enum value, e.g. descriptor.FieldDescriptorProto_TYPE_FIXED64
+	deprecated    string                               // Deprecation comment, if any, e.g. "// Deprecated: Do not use."
+	getterDef     string                               // Default for getters, e.g. "nil", `""` or "Default_MessageType_FieldName"
+	protoDef      string                               // Default value as defined in the proto file, e.g "yoshi" or "5"
+	comment       string                               // The full comment for the field, e.g. "// Useful information"
+}
+
+// decl prints the declaration of the field in the struct (if any).
+func (f *simpleField) decl(g *Generator, mc *msgCtx) {
+	g.P(f.comment, Annotate(mc.message.file, f.fullPath, f.goName), "\t", f.goType, "\t`", f.tags, "`", f.deprecated)
+}
+
+// getter prints the getter for the field.
+func (f *simpleField) getter(g *Generator, mc *msgCtx) {
+	star := ""
+	tname := f.goType
+	if needsStar(f.protoType) && tname[0] == '*' {
+		tname = tname[1:]
+		star = "*"
+	}
+	if f.deprecated != "" {
+		g.P(f.deprecated)
+	}
+	g.P("func (m *", mc.goName, ") ", Annotate(mc.message.file, f.fullPath, f.getterName), "() "+tname+" {")
+	if f.getterDef == "nil" { // Simpler getter
+		g.P("if m != nil {")
+		g.P("return m." + f.goName)
+		g.P("}")
+		g.P("return nil")
+		g.P("}")
+		g.P()
+		return
+	}
+	if mc.message.proto3() {
+		g.P("if m != nil {")
+	} else {
+		g.P("if m != nil && m." + f.goName + " != nil {")
+	}
+	g.P("return " + star + "m." + f.goName)
+	g.P("}")
+	g.P("return ", f.getterDef)
+	g.P("}")
+	g.P()
+}
+
+// setter prints the setter method of the field.
+func (f *simpleField) setter(g *Generator, mc *msgCtx) {
+	// No setter for regular fields yet
+}
+
+// getProtoDef returns the default value explicitly stated in the proto file, e.g "yoshi" or "5".
+func (f *simpleField) getProtoDef() string {
+	return f.protoDef
+}
+
+// getProtoTypeName returns the protobuf type name for the field as returned by field.GetTypeName(), e.g. ".google.protobuf.Duration".
+func (f *simpleField) getProtoTypeName() string {
+	return f.protoTypeName
+}
+
+// getProtoType returns the *field.Type value, e.g. descriptor.FieldDescriptorProto_TYPE_FIXED64.
+func (f *simpleField) getProtoType() descriptor.FieldDescriptorProto_Type {
+	return f.protoType
+}
+
+// oneofSubFields are kept slize held by each oneofField. They do not appear in the top level slize of fields for the message.
+type oneofSubField struct {
+	fieldCommon
+	protoTypeName string                               // Proto type name, empty if primitive, e.g. ".google.protobuf.Duration"
+	protoType     descriptor.FieldDescriptorProto_Type // Actual type enum value, e.g. descriptor.FieldDescriptorProto_TYPE_FIXED64
+	oneofTypeName string                               // Type name of the enclosing struct, e.g. "MessageName_FieldName"
+	fieldNumber   int                                  // Actual field number, as defined in proto, e.g. 12
+	getterDef     string                               // Default for getters, e.g. "nil", `""` or "Default_MessageType_FieldName"
+	protoDef      string                               // Default value as defined in the proto file, e.g "yoshi" or "5"
+}
+
+// wireTypeName returns a textual wire type, needed for oneof sub fields in generated code.
+func (f *oneofSubField) wireTypeName() string {
+	switch f.protoType {
+	case descriptor.FieldDescriptorProto_TYPE_FIXED64,
+		descriptor.FieldDescriptorProto_TYPE_SFIXED64,
+		descriptor.FieldDescriptorProto_TYPE_DOUBLE:
+		return "WireFixed64"
+	case descriptor.FieldDescriptorProto_TYPE_FIXED32,
+		descriptor.FieldDescriptorProto_TYPE_SFIXED32,
+		descriptor.FieldDescriptorProto_TYPE_FLOAT:
+		return "WireFixed32"
+	case descriptor.FieldDescriptorProto_TYPE_GROUP:
+		return "WireStartGroup"
+	case descriptor.FieldDescriptorProto_TYPE_MESSAGE,
+		descriptor.FieldDescriptorProto_TYPE_STRING,
+		descriptor.FieldDescriptorProto_TYPE_BYTES:
+		return "WireBytes"
+	default: // All others are Varints
+		return "WireVarint"
+	}
+}
+
+// typedNil prints a nil casted to the pointer to this field.
+// - for XXX_OneofFuncs
+func (f *oneofSubField) typedNil(g *Generator) {
+	g.P("(*", f.oneofTypeName, ")(nil),")
+}
+
+// marshalCase prints the case matching this oneof subfield in the marshalling code.
+func (f *oneofSubField) marshalCase(g *Generator) {
+	g.P("case *", f.oneofTypeName, ":")
+	wire := f.wireTypeName()
+	var pre, post string
+	val := "x." + f.goName // overridden for TYPE_BOOL
+	switch f.protoType {
+	case descriptor.FieldDescriptorProto_TYPE_DOUBLE:
+		pre = "b.EncodeFixed64(" + g.Pkg["math"] + ".Float64bits("
+		post = "))"
+	case descriptor.FieldDescriptorProto_TYPE_FLOAT:
+		pre = "b.EncodeFixed32(uint64(" + g.Pkg["math"] + ".Float32bits("
+		post = ")))"
+	case descriptor.FieldDescriptorProto_TYPE_INT64, descriptor.FieldDescriptorProto_TYPE_UINT64:
+		pre, post = "b.EncodeVarint(uint64(", "))"
+	case descriptor.FieldDescriptorProto_TYPE_INT32, descriptor.FieldDescriptorProto_TYPE_UINT32, descriptor.FieldDescriptorProto_TYPE_ENUM:
+		pre, post = "b.EncodeVarint(uint64(", "))"
+	case descriptor.FieldDescriptorProto_TYPE_FIXED64, descriptor.FieldDescriptorProto_TYPE_SFIXED64:
+		pre, post = "b.EncodeFixed64(uint64(", "))"
+	case descriptor.FieldDescriptorProto_TYPE_FIXED32, descriptor.FieldDescriptorProto_TYPE_SFIXED32:
+		pre, post = "b.EncodeFixed32(uint64(", "))"
+	case descriptor.FieldDescriptorProto_TYPE_BOOL:
+		g.P("t := uint64(0)")
+		g.P("if ", val, " { t = 1 }")
+		val = "t"
+		pre, post = "b.EncodeVarint(", ")"
+	case descriptor.FieldDescriptorProto_TYPE_STRING:
+		pre, post = "b.EncodeStringBytes(", ")"
+	case descriptor.FieldDescriptorProto_TYPE_GROUP:
+		pre, post = "b.Marshal(", ")"
+	case descriptor.FieldDescriptorProto_TYPE_MESSAGE:
+		pre, post = "b.EncodeMessage(", ")"
+	case descriptor.FieldDescriptorProto_TYPE_BYTES:
+		pre, post = "b.EncodeRawBytes(", ")"
+	case descriptor.FieldDescriptorProto_TYPE_SINT32:
+		pre, post = "b.EncodeZigzag32(uint64(", "))"
+	case descriptor.FieldDescriptorProto_TYPE_SINT64:
+		pre, post = "b.EncodeZigzag64(uint64(", "))"
+	default:
+		g.Fail("unhandled oneof field type ", f.protoType.String())
+	}
+	g.P("b.EncodeVarint(", f.fieldNumber, "<<3|", g.Pkg["proto"], ".", wire, ")")
+	if t := f.protoType; t != descriptor.FieldDescriptorProto_TYPE_GROUP && t != descriptor.FieldDescriptorProto_TYPE_MESSAGE {
+		g.P(pre, val, post)
+	} else {
+		g.P("if err := ", pre, val, post, "; err != nil {")
+		g.P("return err")
+		g.P("}")
+	}
+	if f.protoType == descriptor.FieldDescriptorProto_TYPE_GROUP {
+		g.P("b.EncodeVarint(", f.fieldNumber, "<<3|", g.Pkg["proto"], ".WireEndGroup)")
+	}
+}
+
+// unmarshalCase prints the case matching this oneof subfield in the unmarshalling code.
+func (f *oneofSubField) unmarshalCase(g *Generator, origOneofName string, oneofName string) {
+	g.P("case ", f.fieldNumber, ": // ", origOneofName, ".", f.getProtoName())
+	g.P("if wire != ", g.Pkg["proto"], ".", f.wireTypeName(), " {")
+	g.P("return true, ", g.Pkg["proto"], ".ErrInternalBadWireType")
+	g.P("}")
+	lhs := "x, err" // overridden for TYPE_MESSAGE and TYPE_GROUP
+	var dec, cast, cast2 string
+	switch f.protoType {
+	case descriptor.FieldDescriptorProto_TYPE_DOUBLE:
+		dec, cast = "b.DecodeFixed64()", g.Pkg["math"]+".Float64frombits"
+	case descriptor.FieldDescriptorProto_TYPE_FLOAT:
+		dec, cast, cast2 = "b.DecodeFixed32()", "uint32", g.Pkg["math"]+".Float32frombits"
+	case descriptor.FieldDescriptorProto_TYPE_INT64:
+		dec, cast = "b.DecodeVarint()", "int64"
+	case descriptor.FieldDescriptorProto_TYPE_UINT64:
+		dec = "b.DecodeVarint()"
+	case descriptor.FieldDescriptorProto_TYPE_INT32:
+		dec, cast = "b.DecodeVarint()", "int32"
+	case descriptor.FieldDescriptorProto_TYPE_FIXED64:
+		dec = "b.DecodeFixed64()"
+	case descriptor.FieldDescriptorProto_TYPE_FIXED32:
+		dec, cast = "b.DecodeFixed32()", "uint32"
+	case descriptor.FieldDescriptorProto_TYPE_BOOL:
+		dec = "b.DecodeVarint()"
+		// handled specially below
+	case descriptor.FieldDescriptorProto_TYPE_STRING:
+		dec = "b.DecodeStringBytes()"
+	case descriptor.FieldDescriptorProto_TYPE_GROUP:
+		g.P("msg := new(", f.goType[1:], ")") // drop star
+		lhs = "err"
+		dec = "b.DecodeGroup(msg)"
+		// handled specially below
+	case descriptor.FieldDescriptorProto_TYPE_MESSAGE:
+		g.P("msg := new(", f.goType[1:], ")") // drop star
+		lhs = "err"
+		dec = "b.DecodeMessage(msg)"
+		// handled specially below
+	case descriptor.FieldDescriptorProto_TYPE_BYTES:
+		dec = "b.DecodeRawBytes(true)"
+	case descriptor.FieldDescriptorProto_TYPE_UINT32:
+		dec, cast = "b.DecodeVarint()", "uint32"
+	case descriptor.FieldDescriptorProto_TYPE_ENUM:
+		dec, cast = "b.DecodeVarint()", f.goType
+	case descriptor.FieldDescriptorProto_TYPE_SFIXED32:
+		dec, cast = "b.DecodeFixed32()", "int32"
+	case descriptor.FieldDescriptorProto_TYPE_SFIXED64:
+		dec, cast = "b.DecodeFixed64()", "int64"
+	case descriptor.FieldDescriptorProto_TYPE_SINT32:
+		dec, cast = "b.DecodeZigzag32()", "int32"
+	case descriptor.FieldDescriptorProto_TYPE_SINT64:
+		dec, cast = "b.DecodeZigzag64()", "int64"
+	default:
+		g.Fail("unhandled oneof field type ", f.protoType.String())
+	}
+	g.P(lhs, " := ", dec)
+	val := "x"
+	if cast != "" {
+		val = cast + "(" + val + ")"
+	}
+	if cast2 != "" {
+		val = cast2 + "(" + val + ")"
+	}
+	switch f.protoType {
+	case descriptor.FieldDescriptorProto_TYPE_BOOL:
+		val += " != 0"
+	case descriptor.FieldDescriptorProto_TYPE_GROUP,
+		descriptor.FieldDescriptorProto_TYPE_MESSAGE:
+		val = "msg"
+	}
+	g.P("m.", oneofName, " = &", f.oneofTypeName, "{", val, "}")
+	g.P("return true, err")
+}
+
+// sizerCase prints the case matching this oneof subfield in the sizer code.
+func (f *oneofSubField) sizerCase(g *Generator) {
+	g.P("case *", f.oneofTypeName, ":")
+	val := "x." + f.goName
+	var varint, fixed string
+	switch f.protoType {
+	case descriptor.FieldDescriptorProto_TYPE_DOUBLE:
+		fixed = "8"
+	case descriptor.FieldDescriptorProto_TYPE_FLOAT:
+		fixed = "4"
+	case descriptor.FieldDescriptorProto_TYPE_INT64, descriptor.FieldDescriptorProto_TYPE_UINT64, descriptor.FieldDescriptorProto_TYPE_INT32, descriptor.FieldDescriptorProto_TYPE_UINT32, descriptor.FieldDescriptorProto_TYPE_ENUM:
+		varint = val
+	case descriptor.FieldDescriptorProto_TYPE_FIXED64, descriptor.FieldDescriptorProto_TYPE_SFIXED64:
+		fixed = "8"
+	case descriptor.FieldDescriptorProto_TYPE_FIXED32, descriptor.FieldDescriptorProto_TYPE_SFIXED32:
+		fixed = "4"
+	case descriptor.FieldDescriptorProto_TYPE_BOOL:
+		fixed = "1"
+	case descriptor.FieldDescriptorProto_TYPE_STRING:
+		fixed = "len(" + val + ")"
+		varint = fixed
+	case descriptor.FieldDescriptorProto_TYPE_GROUP:
+		fixed = g.Pkg["proto"] + ".Size(" + val + ")"
+	case descriptor.FieldDescriptorProto_TYPE_MESSAGE:
+		g.P("s := ", g.Pkg["proto"], ".Size(", val, ")")
+		fixed = "s"
+		varint = fixed
+	case descriptor.FieldDescriptorProto_TYPE_BYTES:
+		fixed = "len(" + val + ")"
+		varint = fixed
+	case descriptor.FieldDescriptorProto_TYPE_SINT32:
+		varint = "(uint32(" + val + ") << 1) ^ uint32((int32(" + val + ") >> 31))"
+	case descriptor.FieldDescriptorProto_TYPE_SINT64:
+		varint = "uint64(" + val + " << 1) ^ uint64((int64(" + val + ") >> 63))"
+	default:
+		g.Fail("unhandled oneof field type ", f.protoType.String())
+	}
+	// Tag and wire varint is known statically,
+	// so don't generate code for that part of the size computation.
+	tagAndWireSize := proto.SizeVarint(uint64(f.fieldNumber << 3)) // wire doesn't affect varint size
+	g.P("n += ", tagAndWireSize, " // tag and wire")
+	if varint != "" {
+		g.P("n += ", g.Pkg["proto"], ".SizeVarint(uint64(", varint, "))")
+	}
+	if fixed != "" {
+		g.P("n += ", fixed)
+	}
+	if f.protoType == descriptor.FieldDescriptorProto_TYPE_GROUP {
+		g.P("n += ", tagAndWireSize, " // tag and wire")
+	}
+}
+
+// getProtoDef returns the default value explicitly stated in the proto file, e.g "yoshi" or "5".
+func (f *oneofSubField) getProtoDef() string {
+	return f.protoDef
+}
+
+// getProtoTypeName returns the protobuf type name for the field as returned by field.GetTypeName(), e.g. ".google.protobuf.Duration".
+func (f *oneofSubField) getProtoTypeName() string {
+	return f.protoTypeName
+}
+
+// getProtoType returns the *field.Type value, e.g. descriptor.FieldDescriptorProto_TYPE_FIXED64.
+func (f *oneofSubField) getProtoType() descriptor.FieldDescriptorProto_Type {
+	return f.protoType
+}
+
+// oneofField represents the oneof on top level.
+// The alternative fields within the oneof are represented by oneofSubField.
+type oneofField struct {
+	fieldCommon
+	subFields []*oneofSubField // All the possible oneof fields
+	comment   string           // The full comment for the field, e.g. "// Types that are valid to be assigned to MyOneof:\n\\"
+}
+
+// decl prints the declaration of the field in the struct (if any).
+func (f *oneofField) decl(g *Generator, mc *msgCtx) {
+	comment := f.comment
+	for _, sf := range f.subFields {
+		comment += "//\t*" + sf.oneofTypeName + "\n"
+	}
+	g.P(comment, Annotate(mc.message.file, f.fullPath, f.goName), " ", f.goType, " `", f.tags, "`")
+}
+
+// getter for a oneof field will print additional discriminators and interfaces for the oneof,
+// also it prints all the getters for the sub fields.
+func (f *oneofField) getter(g *Generator, mc *msgCtx) {
+	// The discriminator type
+	g.P("type ", f.goType, " interface {")
+	g.P(f.goType, "()")
+	g.P("}")
+	g.P()
+	// The subField types, fulfilling the discriminator type contract
+	for _, sf := range f.subFields {
+		g.P("type ", Annotate(mc.message.file, sf.fullPath, sf.oneofTypeName), " struct {")
+		g.P(Annotate(mc.message.file, sf.fullPath, sf.goName), " ", sf.goType, " `", sf.tags, "`")
+		g.P("}")
+		g.P()
+	}
+	for _, sf := range f.subFields {
+		g.P("func (*", sf.oneofTypeName, ") ", f.goType, "() {}")
+		g.P()
+	}
+	// Getter for the oneof field
+	g.P("func (m *", mc.goName, ") ", Annotate(mc.message.file, f.fullPath, f.getterName), "() ", f.goType, " {")
+	g.P("if m != nil { return m.", f.goName, " }")
+	g.P("return nil")
+	g.P("}")
+	g.P()
+	// Getters for each oneof
+	for _, sf := range f.subFields {
+		g.P("func (m *", mc.goName, ") ", Annotate(mc.message.file, sf.fullPath, sf.getterName), "() "+sf.goType+" {")
+		g.P("if x, ok := m.", f.getterName, "().(*", sf.oneofTypeName, "); ok {")
+		g.P("return x.", sf.goName)
+		g.P("}")
+		g.P("return ", sf.getterDef)
+		g.P("}")
+		g.P()
+	}
+}
+
+// setter prints the setter method of the field.
+func (f *oneofField) setter(g *Generator, mc *msgCtx) {
+	// No setters for oneof yet
+}
+
+// topLevelField interface implemented by all types of fields on the top level (not oneofSubField).
+type topLevelField interface {
+	decl(g *Generator, mc *msgCtx)   // print declaration within the struct
+	getter(g *Generator, mc *msgCtx) // print getter
+	setter(g *Generator, mc *msgCtx) // print setter if applicable
+}
+
+// defField interface implemented by all types of fields that can have defaults (not oneofField, but instead oneofSubField).
+type defField interface {
+	getProtoDef() string                                // default value explicitly stated in the proto file, e.g "yoshi" or "5"
+	getProtoName() string                               // proto name of a field, e.g. "field_name" or "descriptor"
+	getGoType() string                                  // go type of the field  as a string, e.g. "*int32"
+	getProtoTypeName() string                           // protobuf type name for the field, e.g. ".google.protobuf.Duration"
+	getProtoType() descriptor.FieldDescriptorProto_Type // *field.Type value, e.g. descriptor.FieldDescriptorProto_TYPE_FIXED64
+}
+
+// generateDefaultConstants adds constants for default values if needed, which is only if the default value is.
+// explicit in the proto.
+func (g *Generator) generateDefaultConstants(mc *msgCtx, topLevelFields []topLevelField) {
+	// Collect fields that can have defaults
+	dFields := []defField{}
+	for _, pf := range topLevelFields {
+		if f, ok := pf.(*oneofField); ok {
+			for _, osf := range f.subFields {
+				dFields = append(dFields, osf)
+			}
+			continue
+		}
+		dFields = append(dFields, pf.(defField))
+	}
+	for _, df := range dFields {
+		def := df.getProtoDef()
+		if def == "" {
+			continue
+		}
+		fieldname := g.defaultConstantName(mc.goName, df.getProtoName())
+		typename := df.getGoType()
+		if typename[0] == '*' {
+			typename = typename[1:]
+		}
+		kind := "const "
+		switch {
+		case typename == "bool":
+		case typename == "string":
+			def = strconv.Quote(def)
+		case typename == "[]byte":
+			def = "[]byte(" + strconv.Quote(unescape(def)) + ")"
+			kind = "var "
+		case def == "inf", def == "-inf", def == "nan":
+			// These names are known to, and defined by, the protocol language.
+			switch def {
+			case "inf":
+				def = "math.Inf(1)"
+			case "-inf":
+				def = "math.Inf(-1)"
+			case "nan":
+				def = "math.NaN()"
+			}
+			if df.getProtoType() == descriptor.FieldDescriptorProto_TYPE_FLOAT {
+				def = "float32(" + def + ")"
+			}
+			kind = "var "
+		case df.getProtoType() == descriptor.FieldDescriptorProto_TYPE_ENUM:
+			// Must be an enum.  Need to construct the prefixed name.
+			obj := g.ObjectNamed(df.getProtoTypeName())
+			var enum *EnumDescriptor
+			if id, ok := obj.(*ImportedDescriptor); ok {
+				// The enum type has been publicly imported.
+				enum, _ = id.o.(*EnumDescriptor)
+			} else {
+				enum, _ = obj.(*EnumDescriptor)
+			}
+			if enum == nil {
+				log.Printf("don't know how to generate constant for %s", fieldname)
+				continue
+			}
+			def = g.DefaultPackageName(obj) + enum.prefix() + def
+		}
+		g.P(kind, fieldname, " ", typename, " = ", def)
+		g.file.addExport(mc.message, constOrVarSymbol{fieldname, kind, ""})
+	}
+	g.P()
+}
+
+// generateInternalStructFields just adds the XXX_<something> fields to the message struct.
+func (g *Generator) generateInternalStructFields(mc *msgCtx, topLevelFields []topLevelField) {
+	g.P("XXX_NoUnkeyedLiteral\tstruct{} `json:\"-\"`") // prevent unkeyed struct literals
+	if len(mc.message.ExtensionRange) > 0 {
+		messageset := ""
+		if opts := mc.message.Options; opts != nil && opts.GetMessageSetWireFormat() {
+			messageset = "protobuf_messageset:\"1\" "
+		}
+		g.P(g.Pkg["proto"], ".XXX_InternalExtensions `", messageset, "json:\"-\"`")
+	}
+	g.P("XXX_unrecognized\t[]byte `json:\"-\"`")
+	g.P("XXX_sizecache\tint32 `json:\"-\"`")
+
+}
+
+// generateOneofFuncs adds all the utility functions for oneof, including marshalling, unmarshalling and sizer.
+func (g *Generator) generateOneofFuncs(mc *msgCtx, topLevelFields []topLevelField) {
+	ofields := []*oneofField{}
+	for _, f := range topLevelFields {
+		if o, ok := f.(*oneofField); ok {
+			ofields = append(ofields, o)
+		}
+	}
+	if len(ofields) == 0 {
+		return
+	}
+	enc := "_" + mc.goName + "_OneofMarshaler"
+	dec := "_" + mc.goName + "_OneofUnmarshaler"
+	size := "_" + mc.goName + "_OneofSizer"
+	encSig := "(msg " + g.Pkg["proto"] + ".Message, b *" + g.Pkg["proto"] + ".Buffer) error"
+	decSig := "(msg " + g.Pkg["proto"] + ".Message, tag, wire int, b *" + g.Pkg["proto"] + ".Buffer) (bool, error)"
+	sizeSig := "(msg " + g.Pkg["proto"] + ".Message) (n int)"
+
+	// OneofFuncs
+	g.P("// XXX_OneofFuncs is for the internal use of the proto package.")
+	g.P("func (*", mc.goName, ") XXX_OneofFuncs() (func", encSig, ", func", decSig, ", func", sizeSig, ", []interface{}) {")
+	g.P("return ", enc, ", ", dec, ", ", size, ", []interface{}{")
+	for _, of := range ofields {
+		for _, sf := range of.subFields {
+			sf.typedNil(g)
+		}
+	}
+	g.P("}")
+	g.P("}")
+	g.P()
+
+	// marshaler
+	g.P("func ", enc, encSig, " {")
+	g.P("m := msg.(*", mc.goName, ")")
+	for _, of := range ofields {
+		g.P("// ", of.getProtoName())
+		g.P("switch x := m.", of.goName, ".(type) {")
+		for _, sf := range of.subFields {
+			// also fills in field.wire
+			sf.marshalCase(g)
+		}
+		g.P("case nil:")
+		g.P("default:")
+		g.P(" return ", g.Pkg["fmt"], `.Errorf("`, mc.goName, ".", of.goName, ` has unexpected type %T", x)`)
+		g.P("}")
+	}
+	g.P("return nil")
+	g.P("}")
+	g.P()
+
+	// unmarshaler
+	g.P("func ", dec, decSig, " {")
+	g.P("m := msg.(*", mc.goName, ")")
+	g.P("switch tag {")
+	for _, of := range ofields {
+		for _, sf := range of.subFields {
+			sf.unmarshalCase(g, of.getProtoName(), of.goName)
+		}
+	}
+	g.P("default:")
+	g.P("return false, nil")
+	g.P("}")
+	g.P("}")
+	g.P()
+
+	// sizer
+	g.P("func ", size, sizeSig, " {")
+	g.P("m := msg.(*", mc.goName, ")")
+	for _, of := range ofields {
+		g.P("// ", of.getProtoName())
+		g.P("switch x := m.", of.goName, ".(type) {")
+		for _, sf := range of.subFields {
+			// also fills in field.wire
+			sf.sizerCase(g)
+		}
+		g.P("case nil:")
+		g.P("default:")
+		g.P("panic(", g.Pkg["fmt"], ".Sprintf(\"proto: unexpected type %T in oneof\", x))")
+		g.P("}")
+	}
+	g.P("return n")
+	g.P("}")
+	g.P()
+}
+
+// generateMessageStruct adds the actual struct with it's members (but not methods) to the output.
+func (g *Generator) generateMessageStruct(mc *msgCtx, topLevelFields []topLevelField) {
+	comments := g.PrintComments(mc.message.path)
+
+	// Guarantee deprecation comments appear after user-provided comments.
+	if mc.message.GetOptions().GetDeprecated() {
+		if comments {
+			// Convention: Separate deprecation comments from original
+			// comments with an empty line.
+			g.P("//")
+		}
+		g.P(deprecationComment)
+	}
+
+	g.P("type ", Annotate(mc.message.file, mc.message.path, mc.goName), " struct {")
+	for _, pf := range topLevelFields {
+		pf.decl(g, mc)
+	}
+	g.generateInternalStructFields(mc, topLevelFields)
+	g.P("}")
+}
+
+// generateGetters adds getters for all fields, including oneofs and weak fields when applicable.
+func (g *Generator) generateGetters(mc *msgCtx, topLevelFields []topLevelField) {
+	for _, pf := range topLevelFields {
+		pf.getter(g, mc)
+	}
+}
+
+// generateSetters add setters for all fields, including oneofs and weak fields when applicable.
+func (g *Generator) generateSetters(mc *msgCtx, topLevelFields []topLevelField) {
+	for _, pf := range topLevelFields {
+		pf.setter(g, mc)
+	}
+}
+
+// generateCommonMethods adds methods to the message that are not on a per field basis.
+func (g *Generator) generateCommonMethods(mc *msgCtx) {
+	// Reset, String and ProtoMessage methods.
+	g.P("func (m *", mc.goName, ") Reset() { *m = ", mc.goName, "{} }")
+	g.P("func (m *", mc.goName, ") String() string { return ", g.Pkg["proto"], ".CompactTextString(m) }")
+	g.P("func (*", mc.goName, ") ProtoMessage() {}")
+	var indexes []string
+	for m := mc.message; m != nil; m = m.parent {
+		indexes = append([]string{strconv.Itoa(m.index)}, indexes...)
+	}
+	g.P("func (*", mc.goName, ") Descriptor() ([]byte, []int) {")
+	g.P("return ", g.file.VarName(), ", []int{", strings.Join(indexes, ", "), "}")
+	g.P("}")
+	// TODO: Revisit the decision to use a XXX_WellKnownType method
+	// if we change proto.MessageName to work with multiple equivalents.
+	if mc.message.file.GetPackage() == "google.protobuf" && wellKnownTypes[mc.message.GetName()] {
+		g.P("func (*", mc.goName, `) XXX_WellKnownType() string { return "`, mc.message.GetName(), `" }`)
+	}
+
+	// Extension support methods
+	if len(mc.message.ExtensionRange) > 0 {
+		// message_set_wire_format only makes sense when extensions are defined.
+		if opts := mc.message.Options; opts != nil && opts.GetMessageSetWireFormat() {
+			g.P()
+			g.P("func (m *", mc.goName, ") MarshalJSON() ([]byte, error) {")
+			g.P("return ", g.Pkg["proto"], ".MarshalMessageSetJSON(&m.XXX_InternalExtensions)")
+			g.P("}")
+			g.P("func (m *", mc.goName, ") UnmarshalJSON(buf []byte) error {")
+			g.P("return ", g.Pkg["proto"], ".UnmarshalMessageSetJSON(buf, &m.XXX_InternalExtensions)")
+			g.P("}")
+		}
+
+		g.P()
+		g.P("var extRange_", mc.goName, " = []", g.Pkg["proto"], ".ExtensionRange{")
+		for _, r := range mc.message.ExtensionRange {
+			end := fmt.Sprint(*r.End - 1) // make range inclusive on both ends
+			g.P("{Start: ", r.Start, ", End: ", end, "},")
+		}
+		g.P("}")
+		g.P("func (*", mc.goName, ") ExtensionRangeArray() []", g.Pkg["proto"], ".ExtensionRange {")
+		g.P("return extRange_", mc.goName)
+		g.P("}")
+	}
+
+	// TODO: It does not scale to keep adding another method for every
+	// operation on protos that we want to switch over to using the
+	// table-driven approach. Instead, we should only add a single method
+	// that allows getting access to the *InternalMessageInfo struct and then
+	// calling Unmarshal, Marshal, Merge, Size, and Discard directly on that.
+
+	// Wrapper for table-driven marshaling and unmarshaling.
+	g.P("func (m *", mc.goName, ") XXX_Unmarshal(b []byte) error {")
+	g.P("return xxx_messageInfo_", mc.goName, ".Unmarshal(m, b)")
+	g.P("}")
+
+	g.P("func (m *", mc.goName, ") XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {")
+	g.P("return xxx_messageInfo_", mc.goName, ".Marshal(b, m, deterministic)")
+	g.P("}")
+
+	g.P("func (dst *", mc.goName, ") XXX_Merge(src ", g.Pkg["proto"], ".Message) {")
+	g.P("xxx_messageInfo_", mc.goName, ".Merge(dst, src)")
+	g.P("}")
+
+	g.P("func (m *", mc.goName, ") XXX_Size() int {") // avoid name clash with "Size" field in some message
+	g.P("return xxx_messageInfo_", mc.goName, ".Size(m)")
+	g.P("}")
+
+	g.P("func (m *", mc.goName, ") XXX_DiscardUnknown() {")
+	g.P("xxx_messageInfo_", mc.goName, ".DiscardUnknown(m)")
+	g.P("}")
+
+	g.P("var xxx_messageInfo_", mc.goName, " ", g.Pkg["proto"], ".InternalMessageInfo")
+	g.P()
+}
+
+// Generate the type, methods and default constant definitions for this Descriptor.
+func (g *Generator) generateMessage(message *Descriptor) {
+	topLevelFields := []topLevelField{}
+	oFields := make(map[int32]*oneofField)
+	// The full type name
+	typeName := message.TypeName()
+	// The full type name, CamelCased.
+	goTypeName := CamelCaseSlice(typeName)
+
+	usedNames := make(map[string]bool)
+	for _, n := range methodNames {
+		usedNames[n] = true
+	}
+
+	// allocNames finds a conflict-free variation of the given strings,
+	// consistently mutating their suffixes.
+	// It returns the same number of strings.
+	allocNames := func(ns ...string) []string {
+	Loop:
+		for {
+			for _, n := range ns {
+				if usedNames[n] {
+					for i := range ns {
+						ns[i] += "_"
+					}
+					continue Loop
+				}
+			}
+			for _, n := range ns {
+				usedNames[n] = true
+			}
+			return ns
+		}
+	}
+
+	mapFieldTypes := make(map[*descriptor.FieldDescriptorProto]string) // keep track of the map fields to be added later
+
+	// Build a structure more suitable for generating the text in one pass
+	for i, field := range message.Field {
+		// Allocate the getter and the field at the same time so name
+		// collisions create field/method consistent names.
+		// TODO: This allocation occurs based on the order of the fields
+		// in the proto file, meaning that a change in the field
+		// ordering can change generated Method/Field names.
+		base := CamelCase(*field.Name)
+		ns := allocNames(base, "Get"+base)
+		fieldName, fieldGetterName := ns[0], ns[1]
+		typename, wiretype := g.GoType(message, field)
+		jsonName := *field.Name
+		tag := fmt.Sprintf("protobuf:%s json:%q", g.goTag(message, field, wiretype), jsonName+",omitempty")
+
+		oneof := field.OneofIndex != nil
+		if oneof && oFields[*field.OneofIndex] == nil {
+			odp := message.OneofDecl[int(*field.OneofIndex)]
+			base := CamelCase(odp.GetName())
+			names := allocNames(base, "Get"+base)
+			fname, gname := names[0], names[1]
+
+			// This is the first field of a oneof we haven't seen before.
+			// Generate the union field.
+			oneofFullPath := fmt.Sprintf("%s,%d,%d", message.path, messageOneofPath, *field.OneofIndex)
+			c, ok := g.makeComments(oneofFullPath)
+			if ok {
+				c += "\n//\n"
+			}
+			c += "// Types that are valid to be assigned to " + fname + ":\n"
+			// Generate the rest of this comment later,
+			// when we've computed any disambiguation.
+
+			dname := "is" + goTypeName + "_" + fname
+			tag := `protobuf_oneof:"` + odp.GetName() + `"`
+			of := oneofField{
+				fieldCommon: fieldCommon{
+					goName:     fname,
+					getterName: gname,
+					goType:     dname,
+					tags:       tag,
+					protoName:  odp.GetName(),
+					fullPath:   oneofFullPath,
+				},
+				comment: c,
+			}
+			topLevelFields = append(topLevelFields, &of)
+			oFields[*field.OneofIndex] = &of
+		}
+
+		if *field.Type == descriptor.FieldDescriptorProto_TYPE_MESSAGE {
+			desc := g.ObjectNamed(field.GetTypeName())
+			if d, ok := desc.(*Descriptor); ok && d.GetOptions().GetMapEntry() {
+				// Figure out the Go types and tags for the key and value types.
+				keyField, valField := d.Field[0], d.Field[1]
+				keyType, keyWire := g.GoType(d, keyField)
+				valType, valWire := g.GoType(d, valField)
+				keyTag, valTag := g.goTag(d, keyField, keyWire), g.goTag(d, valField, valWire)
+
+				// We don't use stars, except for message-typed values.
+				// Message and enum types are the only two possibly foreign types used in maps,
+				// so record their use. They are not permitted as map keys.
+				keyType = strings.TrimPrefix(keyType, "*")
+				switch *valField.Type {
+				case descriptor.FieldDescriptorProto_TYPE_ENUM:
+					valType = strings.TrimPrefix(valType, "*")
+					g.RecordTypeUse(valField.GetTypeName())
+				case descriptor.FieldDescriptorProto_TYPE_MESSAGE:
+					g.RecordTypeUse(valField.GetTypeName())
+				default:
+					valType = strings.TrimPrefix(valType, "*")
+				}
+
+				typename = fmt.Sprintf("map[%s]%s", keyType, valType)
+				mapFieldTypes[field] = typename // record for the getter generation
+
+				tag += fmt.Sprintf(" protobuf_key:%s protobuf_val:%s", keyTag, valTag)
+			}
+		}
+
+		dvalue := g.getterDefault(field, goTypeName)
+		if oneof {
+			tname := goTypeName + "_" + fieldName
+			// It is possible for this to collide with a message or enum
+			// nested in this message. Check for collisions.
+			for {
+				ok := true
+				for _, desc := range message.nested {
+					if CamelCaseSlice(desc.TypeName()) == tname {
+						ok = false
+						break
+					}
+				}
+				for _, enum := range message.enums {
+					if CamelCaseSlice(enum.TypeName()) == tname {
+						ok = false
+						break
+					}
+				}
+				if !ok {
+					tname += "_"
+					continue
+				}
+				break
+			}
+
+			oneofField := oFields[*field.OneofIndex]
+			tag := "protobuf:" + g.goTag(message, field, wiretype)
+			sf := oneofSubField{
+				fieldCommon: fieldCommon{
+					goName:     fieldName,
+					getterName: fieldGetterName,
+					goType:     typename,
+					tags:       tag,
+					protoName:  field.GetName(),
+					fullPath:   fmt.Sprintf("%s,%d,%d", message.path, messageFieldPath, i),
+				},
+				protoTypeName: field.GetTypeName(),
+				fieldNumber:   int(*field.Number),
+				protoType:     *field.Type,
+				getterDef:     dvalue,
+				protoDef:      field.GetDefaultValue(),
+				oneofTypeName: tname,
+			}
+			oneofField.subFields = append(oneofField.subFields, &sf)
+			g.RecordTypeUse(field.GetTypeName())
+			continue
+		}
+
+		fieldDeprecated := ""
+		if field.GetOptions().GetDeprecated() {
+			fieldDeprecated = deprecationComment
+		}
+
+		fieldFullPath := fmt.Sprintf("%s,%d,%d", message.path, messageFieldPath, i)
+		c, ok := g.makeComments(fieldFullPath)
+		if ok {
+			c += "\n"
+		}
+		rf := simpleField{
+			fieldCommon: fieldCommon{
+				goName:     fieldName,
+				getterName: fieldGetterName,
+				goType:     typename,
+				tags:       tag,
+				protoName:  field.GetName(),
+				fullPath:   fieldFullPath,
+			},
+			protoTypeName: field.GetTypeName(),
+			protoType:     *field.Type,
+			deprecated:    fieldDeprecated,
+			getterDef:     dvalue,
+			protoDef:      field.GetDefaultValue(),
+			comment:       c,
+		}
+		var pf topLevelField = &rf
+
+		topLevelFields = append(topLevelFields, pf)
+		g.RecordTypeUse(field.GetTypeName())
+	}
+
+	mc := &msgCtx{
+		goName:  goTypeName,
+		message: message,
+	}
+
+	g.generateMessageStruct(mc, topLevelFields)
+	g.P()
+	g.generateCommonMethods(mc)
+	g.P()
+	g.generateDefaultConstants(mc, topLevelFields)
+	g.P()
+	g.generateGetters(mc, topLevelFields)
+	g.P()
+	g.generateSetters(mc, topLevelFields)
+	g.P()
+	g.generateOneofFuncs(mc, topLevelFields)
+	g.P()
+
+	if !message.group {
+
+		var oneofTypes []string
+		for _, f := range topLevelFields {
+			if of, ok := f.(*oneofField); ok {
+				for _, osf := range of.subFields {
+					oneofTypes = append(oneofTypes, osf.oneofTypeName)
+				}
+			}
+		}
+
+		opts := message.Options
+		ms := &messageSymbol{
+			sym:           goTypeName,
+			hasExtensions: len(message.ExtensionRange) > 0,
+			isMessageSet:  opts != nil && opts.GetMessageSetWireFormat(),
+			oneofTypes:    oneofTypes,
+		}
+		g.file.addExport(message, ms)
+	}
+
+	for _, ext := range message.ext {
+		g.generateExtension(ext)
+	}
+
+	fullName := strings.Join(message.TypeName(), ".")
+	if g.file.Package != nil {
+		fullName = *g.file.Package + "." + fullName
+	}
+
+	g.addInitf("%s.RegisterType((*%s)(nil), %q)", g.Pkg["proto"], goTypeName, fullName)
+	// Register types for native map types.
+	for _, k := range mapFieldKeys(mapFieldTypes) {
+		fullName := strings.TrimPrefix(*k.TypeName, ".")
+		g.addInitf("%s.RegisterMapType((%s)(nil), %q)", g.Pkg["proto"], mapFieldTypes[k], fullName)
+	}
+
+}
+
+type byTypeName []*descriptor.FieldDescriptorProto
+
+func (a byTypeName) Len() int           { return len(a) }
+func (a byTypeName) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+func (a byTypeName) Less(i, j int) bool { return *a[i].TypeName < *a[j].TypeName }
+
+// mapFieldKeys returns the keys of m in a consistent order.
+func mapFieldKeys(m map[*descriptor.FieldDescriptorProto]string) []*descriptor.FieldDescriptorProto {
+	keys := make([]*descriptor.FieldDescriptorProto, 0, len(m))
+	for k := range m {
+		keys = append(keys, k)
+	}
+	sort.Sort(byTypeName(keys))
+	return keys
+}
+
+var escapeChars = [256]byte{
+	'a': '\a', 'b': '\b', 'f': '\f', 'n': '\n', 'r': '\r', 't': '\t', 'v': '\v', '\\': '\\', '"': '"', '\'': '\'', '?': '?',
+}
+
+// unescape reverses the "C" escaping that protoc does for default values of bytes fields.
+// It is best effort in that it effectively ignores malformed input. Seemingly invalid escape
+// sequences are conveyed, unmodified, into the decoded result.
+func unescape(s string) string {
+	// NB: Sadly, we can't use strconv.Unquote because protoc will escape both
+	// single and double quotes, but strconv.Unquote only allows one or the
+	// other (based on actual surrounding quotes of its input argument).
+
+	var out []byte
+	for len(s) > 0 {
+		// regular character, or too short to be valid escape
+		if s[0] != '\\' || len(s) < 2 {
+			out = append(out, s[0])
+			s = s[1:]
+		} else if c := escapeChars[s[1]]; c != 0 {
+			// escape sequence
+			out = append(out, c)
+			s = s[2:]
+		} else if s[1] == 'x' || s[1] == 'X' {
+			// hex escape, e.g. "\x80
+			if len(s) < 4 {
+				// too short to be valid
+				out = append(out, s[:2]...)
+				s = s[2:]
+				continue
+			}
+			v, err := strconv.ParseUint(s[2:4], 16, 8)
+			if err != nil {
+				out = append(out, s[:4]...)
+			} else {
+				out = append(out, byte(v))
+			}
+			s = s[4:]
+		} else if '0' <= s[1] && s[1] <= '7' {
+			// octal escape, can vary from 1 to 3 octal digits; e.g., "\0" "\40" or "\164"
+			// so consume up to 2 more bytes or up to end-of-string
+			n := len(s[1:]) - len(strings.TrimLeft(s[1:], "01234567"))
+			if n > 3 {
+				n = 3
+			}
+			v, err := strconv.ParseUint(s[1:1+n], 8, 8)
+			if err != nil {
+				out = append(out, s[:1+n]...)
+			} else {
+				out = append(out, byte(v))
+			}
+			s = s[1+n:]
+		} else {
+			// bad escape, just propagate the slash as-is
+			out = append(out, s[0])
+			s = s[1:]
+		}
+	}
+
+	return string(out)
+}
+
+func (g *Generator) generateExtension(ext *ExtensionDescriptor) {
+	ccTypeName := ext.DescName()
+
+	extObj := g.ObjectNamed(*ext.Extendee)
+	var extDesc *Descriptor
+	if id, ok := extObj.(*ImportedDescriptor); ok {
+		// This is extending a publicly imported message.
+		// We need the underlying type for goTag.
+		extDesc = id.o.(*Descriptor)
+	} else {
+		extDesc = extObj.(*Descriptor)
+	}
+	extendedType := "*" + g.TypeName(extObj) // always use the original
+	field := ext.FieldDescriptorProto
+	fieldType, wireType := g.GoType(ext.parent, field)
+	tag := g.goTag(extDesc, field, wireType)
+	g.RecordTypeUse(*ext.Extendee)
+	if n := ext.FieldDescriptorProto.TypeName; n != nil {
+		// foreign extension type
+		g.RecordTypeUse(*n)
+	}
+
+	typeName := ext.TypeName()
+
+	// Special case for proto2 message sets: If this extension is extending
+	// proto2.bridge.MessageSet, and its final name component is "message_set_extension",
+	// then drop that last component.
+	//
+	// TODO: This should be implemented in the text formatter rather than the generator.
+	// In addition, the situation for when to apply this special case is implemented
+	// differently in other languages:
+	// https://github.com/google/protobuf/blob/aff10976/src/google/protobuf/text_format.cc#L1560
+	mset := false
+	if extDesc.GetOptions().GetMessageSetWireFormat() && typeName[len(typeName)-1] == "message_set_extension" {
+		typeName = typeName[:len(typeName)-1]
+		mset = true
+	}
+
+	// For text formatting, the package must be exactly what the .proto file declares,
+	// ignoring overrides such as the go_package option, and with no dot/underscore mapping.
+	extName := strings.Join(typeName, ".")
+	if g.file.Package != nil {
+		extName = *g.file.Package + "." + extName
+	}
+
+	g.P("var ", ccTypeName, " = &", g.Pkg["proto"], ".ExtensionDesc{")
+	g.P("ExtendedType: (", extendedType, ")(nil),")
+	g.P("ExtensionType: (", fieldType, ")(nil),")
+	g.P("Field: ", field.Number, ",")
+	g.P(`Name: "`, extName, `",`)
+	g.P("Tag: ", tag, ",")
+	g.P(`Filename: "`, g.file.GetName(), `",`)
+
+	g.P("}")
+	g.P()
+
+	if mset {
+		// Generate a bit more code to register with message_set.go.
+		g.addInitf("%s.RegisterMessageSetType((%s)(nil), %d, %q)", g.Pkg["proto"], fieldType, *field.Number, extName)
+	}
+
+	g.file.addExport(ext, constOrVarSymbol{ccTypeName, "var", ""})
+}
+
+func (g *Generator) generateInitFunction() {
+	for _, enum := range g.file.enum {
+		g.generateEnumRegistration(enum)
+	}
+	for _, d := range g.file.desc {
+		for _, ext := range d.ext {
+			g.generateExtensionRegistration(ext)
+		}
+	}
+	for _, ext := range g.file.ext {
+		g.generateExtensionRegistration(ext)
+	}
+	if len(g.init) == 0 {
+		return
+	}
+	g.P("func init() {")
+	for _, l := range g.init {
+		g.P(l)
+	}
+	g.P("}")
+	g.init = nil
+}
+
+func (g *Generator) generateFileDescriptor(file *FileDescriptor) {
+	// Make a copy and trim source_code_info data.
+	// TODO: Trim this more when we know exactly what we need.
+	pb := proto.Clone(file.FileDescriptorProto).(*descriptor.FileDescriptorProto)
+	pb.SourceCodeInfo = nil
+
+	b, err := proto.Marshal(pb)
+	if err != nil {
+		g.Fail(err.Error())
+	}
+
+	var buf bytes.Buffer
+	w, _ := gzip.NewWriterLevel(&buf, gzip.BestCompression)
+	w.Write(b)
+	w.Close()
+	b = buf.Bytes()
+
+	v := file.VarName()
+	g.P()
+	g.P("func init() { ", g.Pkg["proto"], ".RegisterFile(", strconv.Quote(*file.Name), ", ", v, ") }")
+	g.P("var ", v, " = []byte{")
+	g.P("// ", len(b), " bytes of a gzipped FileDescriptorProto")
+	for len(b) > 0 {
+		n := 16
+		if n > len(b) {
+			n = len(b)
+		}
+
+		s := ""
+		for _, c := range b[:n] {
+			s += fmt.Sprintf("0x%02x,", c)
+		}
+		g.P(s)
+
+		b = b[n:]
+	}
+	g.P("}")
+}
+
+func (g *Generator) generateEnumRegistration(enum *EnumDescriptor) {
+	// // We always print the full (proto-world) package name here.
+	pkg := enum.File().GetPackage()
+	if pkg != "" {
+		pkg += "."
+	}
+	// The full type name
+	typeName := enum.TypeName()
+	// The full type name, CamelCased.
+	ccTypeName := CamelCaseSlice(typeName)
+	g.addInitf("%s.RegisterEnum(%q, %[3]s_name, %[3]s_value)", g.Pkg["proto"], pkg+ccTypeName, ccTypeName)
+}
+
+func (g *Generator) generateExtensionRegistration(ext *ExtensionDescriptor) {
+	g.addInitf("%s.RegisterExtension(%s)", g.Pkg["proto"], ext.DescName())
+}
+
+// And now lots of helper functions.
+
+// Is c an ASCII lower-case letter?
+func isASCIILower(c byte) bool {
+	return 'a' <= c && c <= 'z'
+}
+
+// Is c an ASCII digit?
+func isASCIIDigit(c byte) bool {
+	return '0' <= c && c <= '9'
+}
+
+// CamelCase returns the CamelCased name.
+// If there is an interior underscore followed by a lower case letter,
+// drop the underscore and convert the letter to upper case.
+// There is a remote possibility of this rewrite causing a name collision,
+// but it's so remote we're prepared to pretend it's nonexistent - since the
+// C++ generator lowercases names, it's extremely unlikely to have two fields
+// with different capitalizations.
+// In short, _my_field_name_2 becomes XMyFieldName_2.
+func CamelCase(s string) string {
+	if s == "" {
+		return ""
+	}
+	t := make([]byte, 0, 32)
+	i := 0
+	if s[0] == '_' {
+		// Need a capital letter; drop the '_'.
+		t = append(t, 'X')
+		i++
+	}
+	// Invariant: if the next letter is lower case, it must be converted
+	// to upper case.
+	// That is, we process a word at a time, where words are marked by _ or
+	// upper case letter. Digits are treated as words.
+	for ; i < len(s); i++ {
+		c := s[i]
+		if c == '_' && i+1 < len(s) && isASCIILower(s[i+1]) {
+			continue // Skip the underscore in s.
+		}
+		if isASCIIDigit(c) {
+			t = append(t, c)
+			continue
+		}
+		// Assume we have a letter now - if not, it's a bogus identifier.
+		// The next word is a sequence of characters that must start upper case.
+		if isASCIILower(c) {
+			c ^= ' ' // Make it a capital letter.
+		}
+		t = append(t, c) // Guaranteed not lower case.
+		// Accept lower case sequence that follows.
+		for i+1 < len(s) && isASCIILower(s[i+1]) {
+			i++
+			t = append(t, s[i])
+		}
+	}
+	return string(t)
+}
+
+// CamelCaseSlice is like CamelCase, but the argument is a slice of strings to
+// be joined with "_".
+func CamelCaseSlice(elem []string) string { return CamelCase(strings.Join(elem, "_")) }
+
+// dottedSlice turns a sliced name into a dotted name.
+func dottedSlice(elem []string) string { return strings.Join(elem, ".") }
+
+// Is this field optional?
+func isOptional(field *descriptor.FieldDescriptorProto) bool {
+	return field.Label != nil && *field.Label == descriptor.FieldDescriptorProto_LABEL_OPTIONAL
+}
+
+// Is this field required?
+func isRequired(field *descriptor.FieldDescriptorProto) bool {
+	return field.Label != nil && *field.Label == descriptor.FieldDescriptorProto_LABEL_REQUIRED
+}
+
+// Is this field repeated?
+func isRepeated(field *descriptor.FieldDescriptorProto) bool {
+	return field.Label != nil && *field.Label == descriptor.FieldDescriptorProto_LABEL_REPEATED
+}
+
+// Is this field a scalar numeric type?
+func isScalar(field *descriptor.FieldDescriptorProto) bool {
+	if field.Type == nil {
+		return false
+	}
+	switch *field.Type {
+	case descriptor.FieldDescriptorProto_TYPE_DOUBLE,
+		descriptor.FieldDescriptorProto_TYPE_FLOAT,
+		descriptor.FieldDescriptorProto_TYPE_INT64,
+		descriptor.FieldDescriptorProto_TYPE_UINT64,
+		descriptor.FieldDescriptorProto_TYPE_INT32,
+		descriptor.FieldDescriptorProto_TYPE_FIXED64,
+		descriptor.FieldDescriptorProto_TYPE_FIXED32,
+		descriptor.FieldDescriptorProto_TYPE_BOOL,
+		descriptor.FieldDescriptorProto_TYPE_UINT32,
+		descriptor.FieldDescriptorProto_TYPE_ENUM,
+		descriptor.FieldDescriptorProto_TYPE_SFIXED32,
+		descriptor.FieldDescriptorProto_TYPE_SFIXED64,
+		descriptor.FieldDescriptorProto_TYPE_SINT32,
+		descriptor.FieldDescriptorProto_TYPE_SINT64:
+		return true
+	default:
+		return false
+	}
+}
+
+// badToUnderscore is the mapping function used to generate Go names from package names,
+// which can be dotted in the input .proto file.  It replaces non-identifier characters such as
+// dot or dash with underscore.
+func badToUnderscore(r rune) rune {
+	if unicode.IsLetter(r) || unicode.IsDigit(r) || r == '_' {
+		return r
+	}
+	return '_'
+}
+
+// baseName returns the last path element of the name, with the last dotted suffix removed.
+func baseName(name string) string {
+	// First, find the last element
+	if i := strings.LastIndex(name, "/"); i >= 0 {
+		name = name[i+1:]
+	}
+	// Now drop the suffix
+	if i := strings.LastIndex(name, "."); i >= 0 {
+		name = name[0:i]
+	}
+	return name
+}
+
+// The SourceCodeInfo message describes the location of elements of a parsed
+// .proto file by way of a "path", which is a sequence of integers that
+// describe the route from a FileDescriptorProto to the relevant submessage.
+// The path alternates between a field number of a repeated field, and an index
+// into that repeated field. The constants below define the field numbers that
+// are used.
+//
+// See descriptor.proto for more information about this.
+const (
+	// tag numbers in FileDescriptorProto
+	packagePath = 2 // package
+	messagePath = 4 // message_type
+	enumPath    = 5 // enum_type
+	// tag numbers in DescriptorProto
+	messageFieldPath   = 2 // field
+	messageMessagePath = 3 // nested_type
+	messageEnumPath    = 4 // enum_type
+	messageOneofPath   = 8 // oneof_decl
+	// tag numbers in EnumDescriptorProto
+	enumValuePath = 2 // value
+)
+
+var supportTypeAliases bool
+
+func init() {
+	for _, tag := range build.Default.ReleaseTags {
+		if tag == "go1.9" {
+			supportTypeAliases = true
+			return
+		}
+	}
+}
diff --git a/vendor/github.com/golang/protobuf/protoc-gen-go/generator/internal/remap/remap.go b/vendor/github.com/golang/protobuf/protoc-gen-go/generator/internal/remap/remap.go
new file mode 100644
index 0000000..a9b6103
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/protoc-gen-go/generator/internal/remap/remap.go
@@ -0,0 +1,117 @@
+// 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 remap handles tracking the locations of Go tokens in a source text
+across a rewrite by the Go formatter.
+*/
+package remap
+
+import (
+	"fmt"
+	"go/scanner"
+	"go/token"
+)
+
+// A Location represents a span of byte offsets in the source text.
+type Location struct {
+	Pos, End int // End is exclusive
+}
+
+// A Map represents a mapping between token locations in an input source text
+// and locations in the correspnding output text.
+type Map map[Location]Location
+
+// Find reports whether the specified span is recorded by m, and if so returns
+// the new location it was mapped to. If the input span was not found, the
+// returned location is the same as the input.
+func (m Map) Find(pos, end int) (Location, bool) {
+	key := Location{
+		Pos: pos,
+		End: end,
+	}
+	if loc, ok := m[key]; ok {
+		return loc, true
+	}
+	return key, false
+}
+
+func (m Map) add(opos, oend, npos, nend int) {
+	m[Location{Pos: opos, End: oend}] = Location{Pos: npos, End: nend}
+}
+
+// Compute constructs a location mapping from input to output.  An error is
+// reported if any of the tokens of output cannot be mapped.
+func Compute(input, output []byte) (Map, error) {
+	itok := tokenize(input)
+	otok := tokenize(output)
+	if len(itok) != len(otok) {
+		return nil, fmt.Errorf("wrong number of tokens, %d ≠ %d", len(itok), len(otok))
+	}
+	m := make(Map)
+	for i, ti := range itok {
+		to := otok[i]
+		if ti.Token != to.Token {
+			return nil, fmt.Errorf("token %d type mismatch: %s ≠ %s", i+1, ti, to)
+		}
+		m.add(ti.pos, ti.end, to.pos, to.end)
+	}
+	return m, nil
+}
+
+// tokinfo records the span and type of a source token.
+type tokinfo struct {
+	pos, end int
+	token.Token
+}
+
+func tokenize(src []byte) []tokinfo {
+	fs := token.NewFileSet()
+	var s scanner.Scanner
+	s.Init(fs.AddFile("src", fs.Base(), len(src)), src, nil, scanner.ScanComments)
+	var info []tokinfo
+	for {
+		pos, next, lit := s.Scan()
+		switch next {
+		case token.SEMICOLON:
+			continue
+		}
+		info = append(info, tokinfo{
+			pos:   int(pos - 1),
+			end:   int(pos + token.Pos(len(lit)) - 1),
+			Token: next,
+		})
+		if next == token.EOF {
+			break
+		}
+	}
+	return info
+}
diff --git a/vendor/github.com/golang/protobuf/protoc-gen-go/grpc/grpc.go b/vendor/github.com/golang/protobuf/protoc-gen-go/grpc/grpc.go
new file mode 100644
index 0000000..faef1ab
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/protoc-gen-go/grpc/grpc.go
@@ -0,0 +1,484 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2015 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 grpc outputs gRPC service descriptions in Go code.
+// It runs as a plugin for the Go protocol buffer compiler plugin.
+// It is linked in to protoc-gen-go.
+package grpc
+
+import (
+	"fmt"
+	"path"
+	"strconv"
+	"strings"
+
+	pb "github.com/golang/protobuf/protoc-gen-go/descriptor"
+	"github.com/golang/protobuf/protoc-gen-go/generator"
+)
+
+// generatedCodeVersion indicates a version of the generated code.
+// It is incremented whenever an incompatibility between the generated code and
+// the grpc package is introduced; the generated code references
+// a constant, grpc.SupportPackageIsVersionN (where N is generatedCodeVersion).
+const generatedCodeVersion = 4
+
+// Paths for packages used by code generated in this file,
+// relative to the import_prefix of the generator.Generator.
+const (
+	contextPkgPath = "golang.org/x/net/context"
+	grpcPkgPath    = "google.golang.org/grpc"
+)
+
+func init() {
+	generator.RegisterPlugin(new(grpc))
+}
+
+// grpc is an implementation of the Go protocol buffer compiler's
+// plugin architecture.  It generates bindings for gRPC support.
+type grpc struct {
+	gen *generator.Generator
+}
+
+// Name returns the name of this plugin, "grpc".
+func (g *grpc) Name() string {
+	return "grpc"
+}
+
+// The names for packages imported in the generated code.
+// They may vary from the final path component of the import path
+// if the name is used by other packages.
+var (
+	contextPkg string
+	grpcPkg    string
+)
+
+// Init initializes the plugin.
+func (g *grpc) Init(gen *generator.Generator) {
+	g.gen = gen
+	contextPkg = generator.RegisterUniquePackageName("context", nil)
+	grpcPkg = generator.RegisterUniquePackageName("grpc", nil)
+}
+
+// Given a type name defined in a .proto, return its object.
+// Also record that we're using it, to guarantee the associated import.
+func (g *grpc) objectNamed(name string) generator.Object {
+	g.gen.RecordTypeUse(name)
+	return g.gen.ObjectNamed(name)
+}
+
+// Given a type name defined in a .proto, return its name as we will print it.
+func (g *grpc) typeName(str string) string {
+	return g.gen.TypeName(g.objectNamed(str))
+}
+
+// P forwards to g.gen.P.
+func (g *grpc) P(args ...interface{}) { g.gen.P(args...) }
+
+// Generate generates code for the services in the given file.
+func (g *grpc) Generate(file *generator.FileDescriptor) {
+	if len(file.FileDescriptorProto.Service) == 0 {
+		return
+	}
+
+	g.P("// Reference imports to suppress errors if they are not otherwise used.")
+	g.P("var _ ", contextPkg, ".Context")
+	g.P("var _ ", grpcPkg, ".ClientConn")
+	g.P()
+
+	// Assert version compatibility.
+	g.P("// This is a compile-time assertion to ensure that this generated file")
+	g.P("// is compatible with the grpc package it is being compiled against.")
+	g.P("const _ = ", grpcPkg, ".SupportPackageIsVersion", generatedCodeVersion)
+	g.P()
+
+	for i, service := range file.FileDescriptorProto.Service {
+		g.generateService(file, service, i)
+	}
+}
+
+// GenerateImports generates the import declaration for this file.
+func (g *grpc) GenerateImports(file *generator.FileDescriptor) {
+	if len(file.FileDescriptorProto.Service) == 0 {
+		return
+	}
+	g.P("import (")
+	g.P(contextPkg, " ", generator.GoImportPath(path.Join(string(g.gen.ImportPrefix), contextPkgPath)))
+	g.P(grpcPkg, " ", generator.GoImportPath(path.Join(string(g.gen.ImportPrefix), grpcPkgPath)))
+	g.P(")")
+	g.P()
+}
+
+// reservedClientName records whether a client name is reserved on the client side.
+var reservedClientName = map[string]bool{
+	// TODO: do we need any in gRPC?
+}
+
+func unexport(s string) string { return strings.ToLower(s[:1]) + s[1:] }
+
+// deprecationComment is the standard comment added to deprecated
+// messages, fields, enums, and enum values.
+var deprecationComment = "// Deprecated: Do not use."
+
+// generateService generates all the code for the named service.
+func (g *grpc) generateService(file *generator.FileDescriptor, service *pb.ServiceDescriptorProto, index int) {
+	path := fmt.Sprintf("6,%d", index) // 6 means service.
+
+	origServName := service.GetName()
+	fullServName := origServName
+	if pkg := file.GetPackage(); pkg != "" {
+		fullServName = pkg + "." + fullServName
+	}
+	servName := generator.CamelCase(origServName)
+	deprecated := service.GetOptions().GetDeprecated()
+
+	g.P()
+	g.P(fmt.Sprintf(`// %sClient is the client API for %s service.
+//
+// For semantics around ctx use and closing/ending streaming RPCs, please refer to https://godoc.org/google.golang.org/grpc#ClientConn.NewStream.`, servName, servName))
+
+	// Client interface.
+	if deprecated {
+		g.P("//")
+		g.P(deprecationComment)
+	}
+	g.P("type ", servName, "Client interface {")
+	for i, method := range service.Method {
+		g.gen.PrintComments(fmt.Sprintf("%s,2,%d", path, i)) // 2 means method in a service.
+		g.P(g.generateClientSignature(servName, method))
+	}
+	g.P("}")
+	g.P()
+
+	// Client structure.
+	g.P("type ", unexport(servName), "Client struct {")
+	g.P("cc *", grpcPkg, ".ClientConn")
+	g.P("}")
+	g.P()
+
+	// NewClient factory.
+	if deprecated {
+		g.P(deprecationComment)
+	}
+	g.P("func New", servName, "Client (cc *", grpcPkg, ".ClientConn) ", servName, "Client {")
+	g.P("return &", unexport(servName), "Client{cc}")
+	g.P("}")
+	g.P()
+
+	var methodIndex, streamIndex int
+	serviceDescVar := "_" + servName + "_serviceDesc"
+	// Client method implementations.
+	for _, method := range service.Method {
+		var descExpr string
+		if !method.GetServerStreaming() && !method.GetClientStreaming() {
+			// Unary RPC method
+			descExpr = fmt.Sprintf("&%s.Methods[%d]", serviceDescVar, methodIndex)
+			methodIndex++
+		} else {
+			// Streaming RPC method
+			descExpr = fmt.Sprintf("&%s.Streams[%d]", serviceDescVar, streamIndex)
+			streamIndex++
+		}
+		g.generateClientMethod(servName, fullServName, serviceDescVar, method, descExpr)
+	}
+
+	// Server interface.
+	serverType := servName + "Server"
+	g.P("// ", serverType, " is the server API for ", servName, " service.")
+	if deprecated {
+		g.P("//")
+		g.P(deprecationComment)
+	}
+	g.P("type ", serverType, " interface {")
+	for i, method := range service.Method {
+		g.gen.PrintComments(fmt.Sprintf("%s,2,%d", path, i)) // 2 means method in a service.
+		g.P(g.generateServerSignature(servName, method))
+	}
+	g.P("}")
+	g.P()
+
+	// Server registration.
+	if deprecated {
+		g.P(deprecationComment)
+	}
+	g.P("func Register", servName, "Server(s *", grpcPkg, ".Server, srv ", serverType, ") {")
+	g.P("s.RegisterService(&", serviceDescVar, `, srv)`)
+	g.P("}")
+	g.P()
+
+	// Server handler implementations.
+	var handlerNames []string
+	for _, method := range service.Method {
+		hname := g.generateServerMethod(servName, fullServName, method)
+		handlerNames = append(handlerNames, hname)
+	}
+
+	// Service descriptor.
+	g.P("var ", serviceDescVar, " = ", grpcPkg, ".ServiceDesc {")
+	g.P("ServiceName: ", strconv.Quote(fullServName), ",")
+	g.P("HandlerType: (*", serverType, ")(nil),")
+	g.P("Methods: []", grpcPkg, ".MethodDesc{")
+	for i, method := range service.Method {
+		if method.GetServerStreaming() || method.GetClientStreaming() {
+			continue
+		}
+		g.P("{")
+		g.P("MethodName: ", strconv.Quote(method.GetName()), ",")
+		g.P("Handler: ", handlerNames[i], ",")
+		g.P("},")
+	}
+	g.P("},")
+	g.P("Streams: []", grpcPkg, ".StreamDesc{")
+	for i, method := range service.Method {
+		if !method.GetServerStreaming() && !method.GetClientStreaming() {
+			continue
+		}
+		g.P("{")
+		g.P("StreamName: ", strconv.Quote(method.GetName()), ",")
+		g.P("Handler: ", handlerNames[i], ",")
+		if method.GetServerStreaming() {
+			g.P("ServerStreams: true,")
+		}
+		if method.GetClientStreaming() {
+			g.P("ClientStreams: true,")
+		}
+		g.P("},")
+	}
+	g.P("},")
+	g.P("Metadata: \"", file.GetName(), "\",")
+	g.P("}")
+	g.P()
+}
+
+// generateClientSignature returns the client-side signature for a method.
+func (g *grpc) generateClientSignature(servName string, method *pb.MethodDescriptorProto) string {
+	origMethName := method.GetName()
+	methName := generator.CamelCase(origMethName)
+	if reservedClientName[methName] {
+		methName += "_"
+	}
+	reqArg := ", in *" + g.typeName(method.GetInputType())
+	if method.GetClientStreaming() {
+		reqArg = ""
+	}
+	respName := "*" + g.typeName(method.GetOutputType())
+	if method.GetServerStreaming() || method.GetClientStreaming() {
+		respName = servName + "_" + generator.CamelCase(origMethName) + "Client"
+	}
+	return fmt.Sprintf("%s(ctx %s.Context%s, opts ...%s.CallOption) (%s, error)", methName, contextPkg, reqArg, grpcPkg, respName)
+}
+
+func (g *grpc) generateClientMethod(servName, fullServName, serviceDescVar string, method *pb.MethodDescriptorProto, descExpr string) {
+	sname := fmt.Sprintf("/%s/%s", fullServName, method.GetName())
+	methName := generator.CamelCase(method.GetName())
+	inType := g.typeName(method.GetInputType())
+	outType := g.typeName(method.GetOutputType())
+
+	if method.GetOptions().GetDeprecated() {
+		g.P(deprecationComment)
+	}
+	g.P("func (c *", unexport(servName), "Client) ", g.generateClientSignature(servName, method), "{")
+	if !method.GetServerStreaming() && !method.GetClientStreaming() {
+		g.P("out := new(", outType, ")")
+		// TODO: Pass descExpr to Invoke.
+		g.P(`err := c.cc.Invoke(ctx, "`, sname, `", in, out, opts...)`)
+		g.P("if err != nil { return nil, err }")
+		g.P("return out, nil")
+		g.P("}")
+		g.P()
+		return
+	}
+	streamType := unexport(servName) + methName + "Client"
+	g.P("stream, err := c.cc.NewStream(ctx, ", descExpr, `, "`, sname, `", opts...)`)
+	g.P("if err != nil { return nil, err }")
+	g.P("x := &", streamType, "{stream}")
+	if !method.GetClientStreaming() {
+		g.P("if err := x.ClientStream.SendMsg(in); err != nil { return nil, err }")
+		g.P("if err := x.ClientStream.CloseSend(); err != nil { return nil, err }")
+	}
+	g.P("return x, nil")
+	g.P("}")
+	g.P()
+
+	genSend := method.GetClientStreaming()
+	genRecv := method.GetServerStreaming()
+	genCloseAndRecv := !method.GetServerStreaming()
+
+	// Stream auxiliary types and methods.
+	g.P("type ", servName, "_", methName, "Client interface {")
+	if genSend {
+		g.P("Send(*", inType, ") error")
+	}
+	if genRecv {
+		g.P("Recv() (*", outType, ", error)")
+	}
+	if genCloseAndRecv {
+		g.P("CloseAndRecv() (*", outType, ", error)")
+	}
+	g.P(grpcPkg, ".ClientStream")
+	g.P("}")
+	g.P()
+
+	g.P("type ", streamType, " struct {")
+	g.P(grpcPkg, ".ClientStream")
+	g.P("}")
+	g.P()
+
+	if genSend {
+		g.P("func (x *", streamType, ") Send(m *", inType, ") error {")
+		g.P("return x.ClientStream.SendMsg(m)")
+		g.P("}")
+		g.P()
+	}
+	if genRecv {
+		g.P("func (x *", streamType, ") Recv() (*", outType, ", error) {")
+		g.P("m := new(", outType, ")")
+		g.P("if err := x.ClientStream.RecvMsg(m); err != nil { return nil, err }")
+		g.P("return m, nil")
+		g.P("}")
+		g.P()
+	}
+	if genCloseAndRecv {
+		g.P("func (x *", streamType, ") CloseAndRecv() (*", outType, ", error) {")
+		g.P("if err := x.ClientStream.CloseSend(); err != nil { return nil, err }")
+		g.P("m := new(", outType, ")")
+		g.P("if err := x.ClientStream.RecvMsg(m); err != nil { return nil, err }")
+		g.P("return m, nil")
+		g.P("}")
+		g.P()
+	}
+}
+
+// generateServerSignature returns the server-side signature for a method.
+func (g *grpc) generateServerSignature(servName string, method *pb.MethodDescriptorProto) string {
+	origMethName := method.GetName()
+	methName := generator.CamelCase(origMethName)
+	if reservedClientName[methName] {
+		methName += "_"
+	}
+
+	var reqArgs []string
+	ret := "error"
+	if !method.GetServerStreaming() && !method.GetClientStreaming() {
+		reqArgs = append(reqArgs, contextPkg+".Context")
+		ret = "(*" + g.typeName(method.GetOutputType()) + ", error)"
+	}
+	if !method.GetClientStreaming() {
+		reqArgs = append(reqArgs, "*"+g.typeName(method.GetInputType()))
+	}
+	if method.GetServerStreaming() || method.GetClientStreaming() {
+		reqArgs = append(reqArgs, servName+"_"+generator.CamelCase(origMethName)+"Server")
+	}
+
+	return methName + "(" + strings.Join(reqArgs, ", ") + ") " + ret
+}
+
+func (g *grpc) generateServerMethod(servName, fullServName string, method *pb.MethodDescriptorProto) string {
+	methName := generator.CamelCase(method.GetName())
+	hname := fmt.Sprintf("_%s_%s_Handler", servName, methName)
+	inType := g.typeName(method.GetInputType())
+	outType := g.typeName(method.GetOutputType())
+
+	if !method.GetServerStreaming() && !method.GetClientStreaming() {
+		g.P("func ", hname, "(srv interface{}, ctx ", contextPkg, ".Context, dec func(interface{}) error, interceptor ", grpcPkg, ".UnaryServerInterceptor) (interface{}, error) {")
+		g.P("in := new(", inType, ")")
+		g.P("if err := dec(in); err != nil { return nil, err }")
+		g.P("if interceptor == nil { return srv.(", servName, "Server).", methName, "(ctx, in) }")
+		g.P("info := &", grpcPkg, ".UnaryServerInfo{")
+		g.P("Server: srv,")
+		g.P("FullMethod: ", strconv.Quote(fmt.Sprintf("/%s/%s", fullServName, methName)), ",")
+		g.P("}")
+		g.P("handler := func(ctx ", contextPkg, ".Context, req interface{}) (interface{}, error) {")
+		g.P("return srv.(", servName, "Server).", methName, "(ctx, req.(*", inType, "))")
+		g.P("}")
+		g.P("return interceptor(ctx, in, info, handler)")
+		g.P("}")
+		g.P()
+		return hname
+	}
+	streamType := unexport(servName) + methName + "Server"
+	g.P("func ", hname, "(srv interface{}, stream ", grpcPkg, ".ServerStream) error {")
+	if !method.GetClientStreaming() {
+		g.P("m := new(", inType, ")")
+		g.P("if err := stream.RecvMsg(m); err != nil { return err }")
+		g.P("return srv.(", servName, "Server).", methName, "(m, &", streamType, "{stream})")
+	} else {
+		g.P("return srv.(", servName, "Server).", methName, "(&", streamType, "{stream})")
+	}
+	g.P("}")
+	g.P()
+
+	genSend := method.GetServerStreaming()
+	genSendAndClose := !method.GetServerStreaming()
+	genRecv := method.GetClientStreaming()
+
+	// Stream auxiliary types and methods.
+	g.P("type ", servName, "_", methName, "Server interface {")
+	if genSend {
+		g.P("Send(*", outType, ") error")
+	}
+	if genSendAndClose {
+		g.P("SendAndClose(*", outType, ") error")
+	}
+	if genRecv {
+		g.P("Recv() (*", inType, ", error)")
+	}
+	g.P(grpcPkg, ".ServerStream")
+	g.P("}")
+	g.P()
+
+	g.P("type ", streamType, " struct {")
+	g.P(grpcPkg, ".ServerStream")
+	g.P("}")
+	g.P()
+
+	if genSend {
+		g.P("func (x *", streamType, ") Send(m *", outType, ") error {")
+		g.P("return x.ServerStream.SendMsg(m)")
+		g.P("}")
+		g.P()
+	}
+	if genSendAndClose {
+		g.P("func (x *", streamType, ") SendAndClose(m *", outType, ") error {")
+		g.P("return x.ServerStream.SendMsg(m)")
+		g.P("}")
+		g.P()
+	}
+	if genRecv {
+		g.P("func (x *", streamType, ") Recv() (*", inType, ", error) {")
+		g.P("m := new(", inType, ")")
+		g.P("if err := x.ServerStream.RecvMsg(m); err != nil { return nil, err }")
+		g.P("return m, nil")
+		g.P("}")
+		g.P()
+	}
+
+	return hname
+}
diff --git a/vendor/github.com/golang/protobuf/protoc-gen-go/link_grpc.go b/vendor/github.com/golang/protobuf/protoc-gen-go/link_grpc.go
new file mode 100644
index 0000000..532a550
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/protoc-gen-go/link_grpc.go
@@ -0,0 +1,34 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2015 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 main
+
+import _ "github.com/golang/protobuf/protoc-gen-go/grpc"
diff --git a/vendor/github.com/golang/protobuf/protoc-gen-go/main.go b/vendor/github.com/golang/protobuf/protoc-gen-go/main.go
new file mode 100644
index 0000000..8e2486d
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/protoc-gen-go/main.go
@@ -0,0 +1,98 @@
+// 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.
+
+// protoc-gen-go is a plugin for the Google protocol buffer compiler to generate
+// Go code.  Run it by building this program and putting it in your path with
+// the name
+// 	protoc-gen-go
+// That word 'go' at the end becomes part of the option string set for the
+// protocol compiler, so once the protocol compiler (protoc) is installed
+// you can run
+// 	protoc --go_out=output_directory input_directory/file.proto
+// to generate Go bindings for the protocol defined by file.proto.
+// With that input, the output will be written to
+// 	output_directory/file.pb.go
+//
+// The generated code is documented in the package comment for
+// the library.
+//
+// See the README and documentation for protocol buffers to learn more:
+// 	https://developers.google.com/protocol-buffers/
+package main
+
+import (
+	"io/ioutil"
+	"os"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/protoc-gen-go/generator"
+)
+
+func main() {
+	// Begin by allocating a generator. The request and response structures are stored there
+	// so we can do error handling easily - the response structure contains the field to
+	// report failure.
+	g := generator.New()
+
+	data, err := ioutil.ReadAll(os.Stdin)
+	if err != nil {
+		g.Error(err, "reading input")
+	}
+
+	if err := proto.Unmarshal(data, g.Request); err != nil {
+		g.Error(err, "parsing input proto")
+	}
+
+	if len(g.Request.FileToGenerate) == 0 {
+		g.Fail("no files to generate")
+	}
+
+	g.CommandLineParameters(g.Request.GetParameter())
+
+	// Create a wrapped version of the Descriptors and EnumDescriptors that
+	// point to the file that defines them.
+	g.WrapTypes()
+
+	g.SetPackageNames()
+	g.BuildTypeNameMap()
+
+	g.GenerateAllFiles()
+
+	// Send back the results.
+	data, err = proto.Marshal(g.Response)
+	if err != nil {
+		g.Error(err, "failed to marshal output proto")
+	}
+	_, err = os.Stdout.Write(data)
+	if err != nil {
+		g.Error(err, "failed to write output proto")
+	}
+}
diff --git a/vendor/github.com/golang/protobuf/protoc-gen-go/plugin/plugin.pb.golden b/vendor/github.com/golang/protobuf/protoc-gen-go/plugin/plugin.pb.golden
new file mode 100644
index 0000000..8953d0f
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/protoc-gen-go/plugin/plugin.pb.golden
@@ -0,0 +1,83 @@
+// Code generated by protoc-gen-go.
+// source: google/protobuf/compiler/plugin.proto
+// DO NOT EDIT!
+
+package google_protobuf_compiler
+
+import proto "github.com/golang/protobuf/proto"
+import "math"
+import google_protobuf "github.com/golang/protobuf/protoc-gen-go/descriptor"
+
+// Reference proto and math imports to suppress error if they are not otherwise used.
+var _ = proto.GetString
+var _ = math.Inf
+
+type CodeGeneratorRequest struct {
+	FileToGenerate   []string                               `protobuf:"bytes,1,rep,name=file_to_generate" json:"file_to_generate,omitempty"`
+	Parameter        *string                                `protobuf:"bytes,2,opt,name=parameter" json:"parameter,omitempty"`
+	ProtoFile        []*google_protobuf.FileDescriptorProto `protobuf:"bytes,15,rep,name=proto_file" json:"proto_file,omitempty"`
+	XXX_unrecognized []byte                                 `json:"-"`
+}
+
+func (this *CodeGeneratorRequest) Reset()         { *this = CodeGeneratorRequest{} }
+func (this *CodeGeneratorRequest) String() string { return proto.CompactTextString(this) }
+func (*CodeGeneratorRequest) ProtoMessage()       {}
+
+func (this *CodeGeneratorRequest) GetParameter() string {
+	if this != nil && this.Parameter != nil {
+		return *this.Parameter
+	}
+	return ""
+}
+
+type CodeGeneratorResponse struct {
+	Error            *string                       `protobuf:"bytes,1,opt,name=error" json:"error,omitempty"`
+	File             []*CodeGeneratorResponse_File `protobuf:"bytes,15,rep,name=file" json:"file,omitempty"`
+	XXX_unrecognized []byte                        `json:"-"`
+}
+
+func (this *CodeGeneratorResponse) Reset()         { *this = CodeGeneratorResponse{} }
+func (this *CodeGeneratorResponse) String() string { return proto.CompactTextString(this) }
+func (*CodeGeneratorResponse) ProtoMessage()       {}
+
+func (this *CodeGeneratorResponse) GetError() string {
+	if this != nil && this.Error != nil {
+		return *this.Error
+	}
+	return ""
+}
+
+type CodeGeneratorResponse_File struct {
+	Name             *string `protobuf:"bytes,1,opt,name=name" json:"name,omitempty"`
+	InsertionPoint   *string `protobuf:"bytes,2,opt,name=insertion_point" json:"insertion_point,omitempty"`
+	Content          *string `protobuf:"bytes,15,opt,name=content" json:"content,omitempty"`
+	XXX_unrecognized []byte  `json:"-"`
+}
+
+func (this *CodeGeneratorResponse_File) Reset()         { *this = CodeGeneratorResponse_File{} }
+func (this *CodeGeneratorResponse_File) String() string { return proto.CompactTextString(this) }
+func (*CodeGeneratorResponse_File) ProtoMessage()       {}
+
+func (this *CodeGeneratorResponse_File) GetName() string {
+	if this != nil && this.Name != nil {
+		return *this.Name
+	}
+	return ""
+}
+
+func (this *CodeGeneratorResponse_File) GetInsertionPoint() string {
+	if this != nil && this.InsertionPoint != nil {
+		return *this.InsertionPoint
+	}
+	return ""
+}
+
+func (this *CodeGeneratorResponse_File) GetContent() string {
+	if this != nil && this.Content != nil {
+		return *this.Content
+	}
+	return ""
+}
+
+func init() {
+}
diff --git a/vendor/github.com/golang/protobuf/protoc-gen-go/plugin/plugin.proto b/vendor/github.com/golang/protobuf/protoc-gen-go/plugin/plugin.proto
new file mode 100644
index 0000000..5b55745
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/protoc-gen-go/plugin/plugin.proto
@@ -0,0 +1,167 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// 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.
+
+// Author: kenton@google.com (Kenton Varda)
+//
+// WARNING:  The plugin interface is currently EXPERIMENTAL and is subject to
+//   change.
+//
+// protoc (aka the Protocol Compiler) can be extended via plugins.  A plugin is
+// just a program that reads a CodeGeneratorRequest from stdin and writes a
+// CodeGeneratorResponse to stdout.
+//
+// Plugins written using C++ can use google/protobuf/compiler/plugin.h instead
+// of dealing with the raw protocol defined here.
+//
+// A plugin executable needs only to be placed somewhere in the path.  The
+// plugin should be named "protoc-gen-$NAME", and will then be used when the
+// flag "--${NAME}_out" is passed to protoc.
+
+syntax = "proto2";
+package google.protobuf.compiler;
+option java_package = "com.google.protobuf.compiler";
+option java_outer_classname = "PluginProtos";
+
+option go_package = "github.com/golang/protobuf/protoc-gen-go/plugin;plugin_go";
+
+import "google/protobuf/descriptor.proto";
+
+// The version number of protocol compiler.
+message Version {
+  optional int32 major = 1;
+  optional int32 minor = 2;
+  optional int32 patch = 3;
+  // A suffix for alpha, beta or rc release, e.g., "alpha-1", "rc2". It should
+  // be empty for mainline stable releases.
+  optional string suffix = 4;
+}
+
+// An encoded CodeGeneratorRequest is written to the plugin's stdin.
+message CodeGeneratorRequest {
+  // The .proto files that were explicitly listed on the command-line.  The
+  // code generator should generate code only for these files.  Each file's
+  // descriptor will be included in proto_file, below.
+  repeated string file_to_generate = 1;
+
+  // The generator parameter passed on the command-line.
+  optional string parameter = 2;
+
+  // FileDescriptorProtos for all files in files_to_generate and everything
+  // they import.  The files will appear in topological order, so each file
+  // appears before any file that imports it.
+  //
+  // protoc guarantees that all proto_files will be written after
+  // the fields above, even though this is not technically guaranteed by the
+  // protobuf wire format.  This theoretically could allow a plugin to stream
+  // in the FileDescriptorProtos and handle them one by one rather than read
+  // the entire set into memory at once.  However, as of this writing, this
+  // is not similarly optimized on protoc's end -- it will store all fields in
+  // memory at once before sending them to the plugin.
+  //
+  // Type names of fields and extensions in the FileDescriptorProto are always
+  // fully qualified.
+  repeated FileDescriptorProto proto_file = 15;
+
+  // The version number of protocol compiler.
+  optional Version compiler_version = 3;
+
+}
+
+// The plugin writes an encoded CodeGeneratorResponse to stdout.
+message CodeGeneratorResponse {
+  // Error message.  If non-empty, code generation failed.  The plugin process
+  // should exit with status code zero even if it reports an error in this way.
+  //
+  // This should be used to indicate errors in .proto files which prevent the
+  // code generator from generating correct code.  Errors which indicate a
+  // problem in protoc itself -- such as the input CodeGeneratorRequest being
+  // unparseable -- should be reported by writing a message to stderr and
+  // exiting with a non-zero status code.
+  optional string error = 1;
+
+  // Represents a single generated file.
+  message File {
+    // The file name, relative to the output directory.  The name must not
+    // contain "." or ".." components and must be relative, not be absolute (so,
+    // the file cannot lie outside the output directory).  "/" must be used as
+    // the path separator, not "\".
+    //
+    // If the name is omitted, the content will be appended to the previous
+    // file.  This allows the generator to break large files into small chunks,
+    // and allows the generated text to be streamed back to protoc so that large
+    // files need not reside completely in memory at one time.  Note that as of
+    // this writing protoc does not optimize for this -- it will read the entire
+    // CodeGeneratorResponse before writing files to disk.
+    optional string name = 1;
+
+    // If non-empty, indicates that the named file should already exist, and the
+    // content here is to be inserted into that file at a defined insertion
+    // point.  This feature allows a code generator to extend the output
+    // produced by another code generator.  The original generator may provide
+    // insertion points by placing special annotations in the file that look
+    // like:
+    //   @@protoc_insertion_point(NAME)
+    // The annotation can have arbitrary text before and after it on the line,
+    // which allows it to be placed in a comment.  NAME should be replaced with
+    // an identifier naming the point -- this is what other generators will use
+    // as the insertion_point.  Code inserted at this point will be placed
+    // immediately above the line containing the insertion point (thus multiple
+    // insertions to the same point will come out in the order they were added).
+    // The double-@ is intended to make it unlikely that the generated code
+    // could contain things that look like insertion points by accident.
+    //
+    // For example, the C++ code generator places the following line in the
+    // .pb.h files that it generates:
+    //   // @@protoc_insertion_point(namespace_scope)
+    // This line appears within the scope of the file's package namespace, but
+    // outside of any particular class.  Another plugin can then specify the
+    // insertion_point "namespace_scope" to generate additional classes or
+    // other declarations that should be placed in this scope.
+    //
+    // Note that if the line containing the insertion point begins with
+    // whitespace, the same whitespace will be added to every line of the
+    // inserted text.  This is useful for languages like Python, where
+    // indentation matters.  In these languages, the insertion point comment
+    // should be indented the same amount as any inserted code will need to be
+    // in order to work correctly in that context.
+    //
+    // The code generator that generates the initial file and the one which
+    // inserts into it must both run as part of a single invocation of protoc.
+    // Code generators are executed in the order in which they appear on the
+    // command line.
+    //
+    // If |insertion_point| is present, |name| must also be present.
+    optional string insertion_point = 2;
+
+    // The file contents.
+    optional string content = 15;
+  }
+  repeated File file = 15;
+}
diff --git a/vendor/github.com/golang/protobuf/ptypes/any.go b/vendor/github.com/golang/protobuf/ptypes/any.go
new file mode 100644
index 0000000..70276e8
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/ptypes/any.go
@@ -0,0 +1,141 @@
+// 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 ptypes
+
+// This file implements functions to marshal proto.Message to/from
+// google.protobuf.Any message.
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/ptypes/any"
+)
+
+const googleApis = "type.googleapis.com/"
+
+// AnyMessageName returns the name of the message contained in a google.protobuf.Any message.
+//
+// Note that regular type assertions should be done using the Is
+// function. AnyMessageName is provided for less common use cases like filtering a
+// sequence of Any messages based on a set of allowed message type names.
+func AnyMessageName(any *any.Any) (string, error) {
+	if any == nil {
+		return "", fmt.Errorf("message is nil")
+	}
+	slash := strings.LastIndex(any.TypeUrl, "/")
+	if slash < 0 {
+		return "", fmt.Errorf("message type url %q is invalid", any.TypeUrl)
+	}
+	return any.TypeUrl[slash+1:], nil
+}
+
+// MarshalAny takes the protocol buffer and encodes it into google.protobuf.Any.
+func MarshalAny(pb proto.Message) (*any.Any, error) {
+	value, err := proto.Marshal(pb)
+	if err != nil {
+		return nil, err
+	}
+	return &any.Any{TypeUrl: googleApis + proto.MessageName(pb), Value: value}, nil
+}
+
+// DynamicAny is a value that can be passed to UnmarshalAny to automatically
+// allocate a proto.Message for the type specified in a google.protobuf.Any
+// message. The allocated message is stored in the embedded proto.Message.
+//
+// Example:
+//
+//   var x ptypes.DynamicAny
+//   if err := ptypes.UnmarshalAny(a, &x); err != nil { ... }
+//   fmt.Printf("unmarshaled message: %v", x.Message)
+type DynamicAny struct {
+	proto.Message
+}
+
+// Empty returns a new proto.Message of the type specified in a
+// google.protobuf.Any message. It returns an error if corresponding message
+// type isn't linked in.
+func Empty(any *any.Any) (proto.Message, error) {
+	aname, err := AnyMessageName(any)
+	if err != nil {
+		return nil, err
+	}
+
+	t := proto.MessageType(aname)
+	if t == nil {
+		return nil, fmt.Errorf("any: message type %q isn't linked in", aname)
+	}
+	return reflect.New(t.Elem()).Interface().(proto.Message), nil
+}
+
+// UnmarshalAny parses the protocol buffer representation in a google.protobuf.Any
+// message and places the decoded result in pb. It returns an error if type of
+// contents of Any message does not match type of pb message.
+//
+// pb can be a proto.Message, or a *DynamicAny.
+func UnmarshalAny(any *any.Any, pb proto.Message) error {
+	if d, ok := pb.(*DynamicAny); ok {
+		if d.Message == nil {
+			var err error
+			d.Message, err = Empty(any)
+			if err != nil {
+				return err
+			}
+		}
+		return UnmarshalAny(any, d.Message)
+	}
+
+	aname, err := AnyMessageName(any)
+	if err != nil {
+		return err
+	}
+
+	mname := proto.MessageName(pb)
+	if aname != mname {
+		return fmt.Errorf("mismatched message type: got %q want %q", aname, mname)
+	}
+	return proto.Unmarshal(any.Value, pb)
+}
+
+// Is returns true if any value contains a given message type.
+func Is(any *any.Any, pb proto.Message) bool {
+	// The following is equivalent to AnyMessageName(any) == proto.MessageName(pb),
+	// but it avoids scanning TypeUrl for the slash.
+	if any == nil {
+		return false
+	}
+	name := proto.MessageName(pb)
+	prefix := len(any.TypeUrl) - len(name)
+	return prefix >= 1 && any.TypeUrl[prefix-1] == '/' && any.TypeUrl[prefix:] == name
+}
diff --git a/vendor/github.com/golang/protobuf/ptypes/any/any.proto b/vendor/github.com/golang/protobuf/ptypes/any/any.proto
new file mode 100644
index 0000000..c748667
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/ptypes/any/any.proto
@@ -0,0 +1,149 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// 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.
+
+syntax = "proto3";
+
+package google.protobuf;
+
+option csharp_namespace = "Google.Protobuf.WellKnownTypes";
+option go_package = "github.com/golang/protobuf/ptypes/any";
+option java_package = "com.google.protobuf";
+option java_outer_classname = "AnyProto";
+option java_multiple_files = true;
+option objc_class_prefix = "GPB";
+
+// `Any` contains an arbitrary serialized protocol buffer message along with a
+// URL that describes the type of the serialized message.
+//
+// Protobuf library provides support to pack/unpack Any values in the form
+// of utility functions or additional generated methods of the Any type.
+//
+// Example 1: Pack and unpack a message in C++.
+//
+//     Foo foo = ...;
+//     Any any;
+//     any.PackFrom(foo);
+//     ...
+//     if (any.UnpackTo(&foo)) {
+//       ...
+//     }
+//
+// Example 2: Pack and unpack a message in Java.
+//
+//     Foo foo = ...;
+//     Any any = Any.pack(foo);
+//     ...
+//     if (any.is(Foo.class)) {
+//       foo = any.unpack(Foo.class);
+//     }
+//
+//  Example 3: Pack and unpack a message in Python.
+//
+//     foo = Foo(...)
+//     any = Any()
+//     any.Pack(foo)
+//     ...
+//     if any.Is(Foo.DESCRIPTOR):
+//       any.Unpack(foo)
+//       ...
+//
+//  Example 4: Pack and unpack a message in Go
+//
+//      foo := &pb.Foo{...}
+//      any, err := ptypes.MarshalAny(foo)
+//      ...
+//      foo := &pb.Foo{}
+//      if err := ptypes.UnmarshalAny(any, foo); err != nil {
+//        ...
+//      }
+//
+// The pack methods provided by protobuf library will by default use
+// 'type.googleapis.com/full.type.name' as the type URL and the unpack
+// methods only use the fully qualified type name after the last '/'
+// in the type URL, for example "foo.bar.com/x/y.z" will yield type
+// name "y.z".
+//
+//
+// JSON
+// ====
+// The JSON representation of an `Any` value uses the regular
+// representation of the deserialized, embedded message, with an
+// additional field `@type` which contains the type URL. Example:
+//
+//     package google.profile;
+//     message Person {
+//       string first_name = 1;
+//       string last_name = 2;
+//     }
+//
+//     {
+//       "@type": "type.googleapis.com/google.profile.Person",
+//       "firstName": <string>,
+//       "lastName": <string>
+//     }
+//
+// If the embedded message type is well-known and has a custom JSON
+// representation, that representation will be embedded adding a field
+// `value` which holds the custom JSON in addition to the `@type`
+// field. Example (for message [google.protobuf.Duration][]):
+//
+//     {
+//       "@type": "type.googleapis.com/google.protobuf.Duration",
+//       "value": "1.212s"
+//     }
+//
+message Any {
+  // A URL/resource name whose content describes the type of the
+  // serialized protocol buffer message.
+  //
+  // For URLs which use the scheme `http`, `https`, or no scheme, the
+  // following restrictions and interpretations apply:
+  //
+  // * If no scheme is provided, `https` is assumed.
+  // * The last segment of the URL's path must represent the fully
+  //   qualified name of the type (as in `path/google.protobuf.Duration`).
+  //   The name should be in a canonical form (e.g., leading "." is
+  //   not accepted).
+  // * An HTTP GET on the URL must yield a [google.protobuf.Type][]
+  //   value in binary format, or produce an error.
+  // * Applications are allowed to cache lookup results based on the
+  //   URL, or have them precompiled into a binary to avoid any
+  //   lookup. Therefore, binary compatibility needs to be preserved
+  //   on changes to types. (Use versioned type names to manage
+  //   breaking changes.)
+  //
+  // Schemes other than `http`, `https` (or the empty scheme) might be
+  // used with implementation specific semantics.
+  //
+  string type_url = 1;
+
+  // Must be a valid serialized protocol buffer of the above specified type.
+  bytes value = 2;
+}
diff --git a/vendor/github.com/golang/protobuf/ptypes/doc.go b/vendor/github.com/golang/protobuf/ptypes/doc.go
new file mode 100644
index 0000000..c0d595d
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/ptypes/doc.go
@@ -0,0 +1,35 @@
+// 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 ptypes contains code for interacting with well-known types.
+*/
+package ptypes
diff --git a/vendor/github.com/golang/protobuf/ptypes/duration.go b/vendor/github.com/golang/protobuf/ptypes/duration.go
new file mode 100644
index 0000000..65cb0f8
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/ptypes/duration.go
@@ -0,0 +1,102 @@
+// 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 ptypes
+
+// This file implements conversions between google.protobuf.Duration
+// and time.Duration.
+
+import (
+	"errors"
+	"fmt"
+	"time"
+
+	durpb "github.com/golang/protobuf/ptypes/duration"
+)
+
+const (
+	// Range of a durpb.Duration in seconds, as specified in
+	// google/protobuf/duration.proto. This is about 10,000 years in seconds.
+	maxSeconds = int64(10000 * 365.25 * 24 * 60 * 60)
+	minSeconds = -maxSeconds
+)
+
+// validateDuration determines whether the durpb.Duration is valid according to the
+// definition in google/protobuf/duration.proto. A valid durpb.Duration
+// may still be too large to fit into a time.Duration (the range of durpb.Duration
+// is about 10,000 years, and the range of time.Duration is about 290).
+func validateDuration(d *durpb.Duration) error {
+	if d == nil {
+		return errors.New("duration: nil Duration")
+	}
+	if d.Seconds < minSeconds || d.Seconds > maxSeconds {
+		return fmt.Errorf("duration: %v: seconds out of range", d)
+	}
+	if d.Nanos <= -1e9 || d.Nanos >= 1e9 {
+		return fmt.Errorf("duration: %v: nanos out of range", d)
+	}
+	// Seconds and Nanos must have the same sign, unless d.Nanos is zero.
+	if (d.Seconds < 0 && d.Nanos > 0) || (d.Seconds > 0 && d.Nanos < 0) {
+		return fmt.Errorf("duration: %v: seconds and nanos have different signs", d)
+	}
+	return nil
+}
+
+// Duration converts a durpb.Duration to a time.Duration. Duration
+// returns an error if the durpb.Duration is invalid or is too large to be
+// represented in a time.Duration.
+func Duration(p *durpb.Duration) (time.Duration, error) {
+	if err := validateDuration(p); err != nil {
+		return 0, err
+	}
+	d := time.Duration(p.Seconds) * time.Second
+	if int64(d/time.Second) != p.Seconds {
+		return 0, fmt.Errorf("duration: %v is out of range for time.Duration", p)
+	}
+	if p.Nanos != 0 {
+		d += time.Duration(p.Nanos)
+		if (d < 0) != (p.Nanos < 0) {
+			return 0, fmt.Errorf("duration: %v is out of range for time.Duration", p)
+		}
+	}
+	return d, nil
+}
+
+// DurationProto converts a time.Duration to a durpb.Duration.
+func DurationProto(d time.Duration) *durpb.Duration {
+	nanos := d.Nanoseconds()
+	secs := nanos / 1e9
+	nanos -= secs * 1e9
+	return &durpb.Duration{
+		Seconds: secs,
+		Nanos:   int32(nanos),
+	}
+}
diff --git a/vendor/github.com/golang/protobuf/ptypes/duration/duration.proto b/vendor/github.com/golang/protobuf/ptypes/duration/duration.proto
new file mode 100644
index 0000000..975fce4
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/ptypes/duration/duration.proto
@@ -0,0 +1,117 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// 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.
+
+syntax = "proto3";
+
+package google.protobuf;
+
+option csharp_namespace = "Google.Protobuf.WellKnownTypes";
+option cc_enable_arenas = true;
+option go_package = "github.com/golang/protobuf/ptypes/duration";
+option java_package = "com.google.protobuf";
+option java_outer_classname = "DurationProto";
+option java_multiple_files = true;
+option objc_class_prefix = "GPB";
+
+// A Duration represents a signed, fixed-length span of time represented
+// as a count of seconds and fractions of seconds at nanosecond
+// resolution. It is independent of any calendar and concepts like "day"
+// or "month". It is related to Timestamp in that the difference between
+// two Timestamp values is a Duration and it can be added or subtracted
+// from a Timestamp. Range is approximately +-10,000 years.
+//
+// # Examples
+//
+// Example 1: Compute Duration from two Timestamps in pseudo code.
+//
+//     Timestamp start = ...;
+//     Timestamp end = ...;
+//     Duration duration = ...;
+//
+//     duration.seconds = end.seconds - start.seconds;
+//     duration.nanos = end.nanos - start.nanos;
+//
+//     if (duration.seconds < 0 && duration.nanos > 0) {
+//       duration.seconds += 1;
+//       duration.nanos -= 1000000000;
+//     } else if (durations.seconds > 0 && duration.nanos < 0) {
+//       duration.seconds -= 1;
+//       duration.nanos += 1000000000;
+//     }
+//
+// Example 2: Compute Timestamp from Timestamp + Duration in pseudo code.
+//
+//     Timestamp start = ...;
+//     Duration duration = ...;
+//     Timestamp end = ...;
+//
+//     end.seconds = start.seconds + duration.seconds;
+//     end.nanos = start.nanos + duration.nanos;
+//
+//     if (end.nanos < 0) {
+//       end.seconds -= 1;
+//       end.nanos += 1000000000;
+//     } else if (end.nanos >= 1000000000) {
+//       end.seconds += 1;
+//       end.nanos -= 1000000000;
+//     }
+//
+// Example 3: Compute Duration from datetime.timedelta in Python.
+//
+//     td = datetime.timedelta(days=3, minutes=10)
+//     duration = Duration()
+//     duration.FromTimedelta(td)
+//
+// # JSON Mapping
+//
+// In JSON format, the Duration type is encoded as a string rather than an
+// object, where the string ends in the suffix "s" (indicating seconds) and
+// is preceded by the number of seconds, with nanoseconds expressed as
+// fractional seconds. For example, 3 seconds with 0 nanoseconds should be
+// encoded in JSON format as "3s", while 3 seconds and 1 nanosecond should
+// be expressed in JSON format as "3.000000001s", and 3 seconds and 1
+// microsecond should be expressed in JSON format as "3.000001s".
+//
+//
+message Duration {
+
+  // Signed seconds of the span of time. Must be from -315,576,000,000
+  // to +315,576,000,000 inclusive. Note: these bounds are computed from:
+  // 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
+  int64 seconds = 1;
+
+  // Signed fractions of a second at nanosecond resolution of the span
+  // of time. Durations less than one second are represented with a 0
+  // `seconds` field and a positive or negative `nanos` field. For durations
+  // of one second or more, a non-zero value for the `nanos` field must be
+  // of the same sign as the `seconds` field. Must be from -999,999,999
+  // to +999,999,999 inclusive.
+  int32 nanos = 2;
+}
diff --git a/vendor/github.com/golang/protobuf/ptypes/empty/empty.proto b/vendor/github.com/golang/protobuf/ptypes/empty/empty.proto
new file mode 100644
index 0000000..03cacd2
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/ptypes/empty/empty.proto
@@ -0,0 +1,52 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// 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.
+
+syntax = "proto3";
+
+package google.protobuf;
+
+option csharp_namespace = "Google.Protobuf.WellKnownTypes";
+option go_package = "github.com/golang/protobuf/ptypes/empty";
+option java_package = "com.google.protobuf";
+option java_outer_classname = "EmptyProto";
+option java_multiple_files = true;
+option objc_class_prefix = "GPB";
+option cc_enable_arenas = true;
+
+// A generic empty message that you can re-use to avoid defining duplicated
+// empty messages in your APIs. A typical example is to use it as the request
+// or the response type of an API method. For instance:
+//
+//     service Foo {
+//       rpc Bar(google.protobuf.Empty) returns (google.protobuf.Empty);
+//     }
+//
+// The JSON representation for `Empty` is empty JSON object `{}`.
+message Empty {}
diff --git a/vendor/github.com/golang/protobuf/ptypes/timestamp.go b/vendor/github.com/golang/protobuf/ptypes/timestamp.go
new file mode 100644
index 0000000..47f10db
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/ptypes/timestamp.go
@@ -0,0 +1,134 @@
+// 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 ptypes
+
+// This file implements operations on google.protobuf.Timestamp.
+
+import (
+	"errors"
+	"fmt"
+	"time"
+
+	tspb "github.com/golang/protobuf/ptypes/timestamp"
+)
+
+const (
+	// Seconds field of the earliest valid Timestamp.
+	// This is time.Date(1, 1, 1, 0, 0, 0, 0, time.UTC).Unix().
+	minValidSeconds = -62135596800
+	// Seconds field just after the latest valid Timestamp.
+	// This is time.Date(10000, 1, 1, 0, 0, 0, 0, time.UTC).Unix().
+	maxValidSeconds = 253402300800
+)
+
+// validateTimestamp determines whether a Timestamp is valid.
+// A valid timestamp represents a time in the range
+// [0001-01-01, 10000-01-01) and has a Nanos field
+// in the range [0, 1e9).
+//
+// If the Timestamp is valid, validateTimestamp returns nil.
+// Otherwise, it returns an error that describes
+// the problem.
+//
+// Every valid Timestamp can be represented by a time.Time, but the converse is not true.
+func validateTimestamp(ts *tspb.Timestamp) error {
+	if ts == nil {
+		return errors.New("timestamp: nil Timestamp")
+	}
+	if ts.Seconds < minValidSeconds {
+		return fmt.Errorf("timestamp: %v before 0001-01-01", ts)
+	}
+	if ts.Seconds >= maxValidSeconds {
+		return fmt.Errorf("timestamp: %v after 10000-01-01", ts)
+	}
+	if ts.Nanos < 0 || ts.Nanos >= 1e9 {
+		return fmt.Errorf("timestamp: %v: nanos not in range [0, 1e9)", ts)
+	}
+	return nil
+}
+
+// Timestamp converts a google.protobuf.Timestamp proto to a time.Time.
+// It returns an error if the argument is invalid.
+//
+// Unlike most Go functions, if Timestamp returns an error, the first return value
+// is not the zero time.Time. Instead, it is the value obtained from the
+// time.Unix function when passed the contents of the Timestamp, in the UTC
+// locale. This may or may not be a meaningful time; many invalid Timestamps
+// do map to valid time.Times.
+//
+// A nil Timestamp returns an error. The first return value in that case is
+// undefined.
+func Timestamp(ts *tspb.Timestamp) (time.Time, error) {
+	// Don't return the zero value on error, because corresponds to a valid
+	// timestamp. Instead return whatever time.Unix gives us.
+	var t time.Time
+	if ts == nil {
+		t = time.Unix(0, 0).UTC() // treat nil like the empty Timestamp
+	} else {
+		t = time.Unix(ts.Seconds, int64(ts.Nanos)).UTC()
+	}
+	return t, validateTimestamp(ts)
+}
+
+// TimestampNow returns a google.protobuf.Timestamp for the current time.
+func TimestampNow() *tspb.Timestamp {
+	ts, err := TimestampProto(time.Now())
+	if err != nil {
+		panic("ptypes: time.Now() out of Timestamp range")
+	}
+	return ts
+}
+
+// TimestampProto converts the time.Time to a google.protobuf.Timestamp proto.
+// It returns an error if the resulting Timestamp is invalid.
+func TimestampProto(t time.Time) (*tspb.Timestamp, error) {
+	seconds := t.Unix()
+	nanos := int32(t.Sub(time.Unix(seconds, 0)))
+	ts := &tspb.Timestamp{
+		Seconds: seconds,
+		Nanos:   nanos,
+	}
+	if err := validateTimestamp(ts); err != nil {
+		return nil, err
+	}
+	return ts, nil
+}
+
+// TimestampString returns the RFC 3339 string for valid Timestamps. For invalid
+// Timestamps, it returns an error message in parentheses.
+func TimestampString(ts *tspb.Timestamp) string {
+	t, err := Timestamp(ts)
+	if err != nil {
+		return fmt.Sprintf("(%v)", err)
+	}
+	return t.Format(time.RFC3339Nano)
+}
diff --git a/vendor/github.com/golang/protobuf/ptypes/timestamp/timestamp.proto b/vendor/github.com/golang/protobuf/ptypes/timestamp/timestamp.proto
new file mode 100644
index 0000000..06750ab
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/ptypes/timestamp/timestamp.proto
@@ -0,0 +1,133 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// 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.
+
+syntax = "proto3";
+
+package google.protobuf;
+
+option csharp_namespace = "Google.Protobuf.WellKnownTypes";
+option cc_enable_arenas = true;
+option go_package = "github.com/golang/protobuf/ptypes/timestamp";
+option java_package = "com.google.protobuf";
+option java_outer_classname = "TimestampProto";
+option java_multiple_files = true;
+option objc_class_prefix = "GPB";
+
+// A Timestamp represents a point in time independent of any time zone
+// or calendar, represented as seconds and fractions of seconds at
+// nanosecond resolution in UTC Epoch time. It is encoded using the
+// Proleptic Gregorian Calendar which extends the Gregorian calendar
+// backwards to year one. It is encoded assuming all minutes are 60
+// seconds long, i.e. leap seconds are "smeared" so that no leap second
+// table is needed for interpretation. Range is from
+// 0001-01-01T00:00:00Z to 9999-12-31T23:59:59.999999999Z.
+// By restricting to that range, we ensure that we can convert to
+// and from  RFC 3339 date strings.
+// See [https://www.ietf.org/rfc/rfc3339.txt](https://www.ietf.org/rfc/rfc3339.txt).
+//
+// # Examples
+//
+// Example 1: Compute Timestamp from POSIX `time()`.
+//
+//     Timestamp timestamp;
+//     timestamp.set_seconds(time(NULL));
+//     timestamp.set_nanos(0);
+//
+// Example 2: Compute Timestamp from POSIX `gettimeofday()`.
+//
+//     struct timeval tv;
+//     gettimeofday(&tv, NULL);
+//
+//     Timestamp timestamp;
+//     timestamp.set_seconds(tv.tv_sec);
+//     timestamp.set_nanos(tv.tv_usec * 1000);
+//
+// Example 3: Compute Timestamp from Win32 `GetSystemTimeAsFileTime()`.
+//
+//     FILETIME ft;
+//     GetSystemTimeAsFileTime(&ft);
+//     UINT64 ticks = (((UINT64)ft.dwHighDateTime) << 32) | ft.dwLowDateTime;
+//
+//     // A Windows tick is 100 nanoseconds. Windows epoch 1601-01-01T00:00:00Z
+//     // is 11644473600 seconds before Unix epoch 1970-01-01T00:00:00Z.
+//     Timestamp timestamp;
+//     timestamp.set_seconds((INT64) ((ticks / 10000000) - 11644473600LL));
+//     timestamp.set_nanos((INT32) ((ticks % 10000000) * 100));
+//
+// Example 4: Compute Timestamp from Java `System.currentTimeMillis()`.
+//
+//     long millis = System.currentTimeMillis();
+//
+//     Timestamp timestamp = Timestamp.newBuilder().setSeconds(millis / 1000)
+//         .setNanos((int) ((millis % 1000) * 1000000)).build();
+//
+//
+// Example 5: Compute Timestamp from current time in Python.
+//
+//     timestamp = Timestamp()
+//     timestamp.GetCurrentTime()
+//
+// # JSON Mapping
+//
+// In JSON format, the Timestamp type is encoded as a string in the
+// [RFC 3339](https://www.ietf.org/rfc/rfc3339.txt) format. That is, the
+// format is "{year}-{month}-{day}T{hour}:{min}:{sec}[.{frac_sec}]Z"
+// where {year} is always expressed using four digits while {month}, {day},
+// {hour}, {min}, and {sec} are zero-padded to two digits each. The fractional
+// seconds, which can go up to 9 digits (i.e. up to 1 nanosecond resolution),
+// are optional. The "Z" suffix indicates the timezone ("UTC"); the timezone
+// is required, though only UTC (as indicated by "Z") is presently supported.
+//
+// For example, "2017-01-15T01:30:15.01Z" encodes 15.01 seconds past
+// 01:30 UTC on January 15, 2017.
+//
+// In JavaScript, one can convert a Date object to this format using the
+// standard [toISOString()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toISOString]
+// method. In Python, a standard `datetime.datetime` object can be converted
+// to this format using [`strftime`](https://docs.python.org/2/library/time.html#time.strftime)
+// with the time format spec '%Y-%m-%dT%H:%M:%S.%fZ'. Likewise, in Java, one
+// can use the Joda Time's [`ISODateTimeFormat.dateTime()`](
+// http://www.joda.org/joda-time/apidocs/org/joda/time/format/ISODateTimeFormat.html#dateTime--)
+// to obtain a formatter capable of generating timestamps in this format.
+//
+//
+message Timestamp {
+
+  // Represents seconds of UTC time since Unix epoch
+  // 1970-01-01T00:00:00Z. Must be from 0001-01-01T00:00:00Z to
+  // 9999-12-31T23:59:59Z inclusive.
+  int64 seconds = 1;
+
+  // Non-negative fractions of a second at nanosecond resolution. Negative
+  // second values with fractions must still have non-negative nanos values
+  // that count forward in time. Must be from 0 to 999,999,999
+  // inclusive.
+  int32 nanos = 2;
+}