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[bytom/vapor.git] / vendor / github.com / gogo / protobuf / proto / table_marshal.go
diff --git a/vendor/github.com/gogo/protobuf/proto/table_marshal.go b/vendor/github.com/gogo/protobuf/proto/table_marshal.go
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+// 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
+
+       hassizer      bool // has custom sizer
+       hasprotosizer bool // has custom protosizer
+
+       bytesExtensions field // offset of XXX_extensions where the field type is []byte
+}
+
+// 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
+
+       uint8SliceType = reflect.TypeOf(([]uint8)(nil)).Kind()
+)
+
+// 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 {
+               // Uses the message's Size method if available
+               if u.hassizer {
+                       s := ptr.asPointerTo(u.typ).Interface().(Sizer)
+                       return s.Size()
+               }
+               // Uses the message's ProtoSize method if available
+               if u.hasprotosizer {
+                       s := ptr.asPointerTo(u.typ).Interface().(ProtoSizer)
+                       return s.ProtoSize()
+               }
+
+               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.bytesExtensions.IsValid() {
+               s := *ptr.offset(u.bytesExtensions).toBytes()
+               n += len(s)
+       }
+       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
+               }
+       }
+       if u.bytesExtensions.IsValid() {
+               s := *ptr.offset(u.bytesExtensions).toBytes()
+               b = append(b, s...)
+       }
+       for _, f := range u.fields {
+               if f.required {
+                       if f.isPointer && 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.bytesExtensions = invalidField
+       u.sizecache = invalidField
+       isOneofMessage := false
+
+       if reflect.PtrTo(t).Implements(sizerType) {
+               u.hassizer = true
+       }
+       if reflect.PtrTo(t).Implements(protosizerType) {
+               u.hasprotosizer = true
+       }
+       // 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
+       }
+
+       n := t.NumField()
+
+       // deal with XXX fields first
+       for i := 0; i < t.NumField(); i++ {
+               f := t.Field(i)
+               if f.Tag.Get("protobuf_oneof") != "" {
+                       isOneofMessage = true
+               }
+               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":
+                       if f.Type.Kind() == reflect.Map {
+                               u.v1extensions = toField(&f)
+                       } else {
+                               u.bytesExtensions = toField(&f)
+                       }
+               case "XXX_NoUnkeyedLiteral":
+                       // nothing to do
+               default:
+                       panic("unknown XXX field: " + f.Name)
+               }
+               n--
+       }
+
+       // get oneof implementers
+       var oneofImplementers []interface{}
+       // gogo: isOneofMessage is needed for embedded oneof messages, without a marshaler and unmarshaler
+       if m, ok := reflect.Zero(reflect.PtrTo(t)).Interface().(oneofMessage); ok && isOneofMessage {
+               _, _, _, oneofImplementers = m.XXX_OneofFuncs()
+       }
+
+       // 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])
+       sizr, marshalr := typeMarshaler(t, tags, false, false)
+       e = &marshalElemInfo{
+               wiretag:   uint64(tag)<<3 | wt,
+               tagsize:   SizeVarint(uint64(tag) << 3),
+               sizer:     sizr,
+               marshaler: marshalr,
+               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 = math.MaxInt32 // 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])
+               sizr, marshalr := 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:     sizr,
+                       marshaler: marshalr,
+               }
+       }
+}
+
+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
+       ctype := false
+       isTime := false
+       isDuration := false
+       isWktPointer := false
+       validateUTF8 := true
+       for i := 2; i < len(tags); i++ {
+               if tags[i] == "packed" {
+                       packed = true
+               }
+               if tags[i] == "proto3" {
+                       proto3 = true
+               }
+               if strings.HasPrefix(tags[i], "customtype=") {
+                       ctype = true
+               }
+               if tags[i] == "stdtime" {
+                       isTime = true
+               }
+               if tags[i] == "stdduration" {
+                       isDuration = true
+               }
+               if tags[i] == "wktptr" {
+                       isWktPointer = true
+               }
+       }
+       validateUTF8 = validateUTF8 && proto3
+       if !proto3 && !pointer && !slice {
+               nozero = false
+       }
+
+       if ctype {
+               if reflect.PtrTo(t).Implements(customType) {
+                       if slice {
+                               return makeMessageRefSliceMarshaler(getMarshalInfo(t))
+                       }
+                       if pointer {
+                               return makeCustomPtrMarshaler(getMarshalInfo(t))
+                       }
+                       return makeCustomMarshaler(getMarshalInfo(t))
+               } else {
+                       panic(fmt.Sprintf("custom type: type: %v, does not implement the proto.custom interface", t))
+               }
+       }
+
+       if isTime {
+               if pointer {
+                       if slice {
+                               return makeTimePtrSliceMarshaler(getMarshalInfo(t))
+                       }
+                       return makeTimePtrMarshaler(getMarshalInfo(t))
+               }
+               if slice {
+                       return makeTimeSliceMarshaler(getMarshalInfo(t))
+               }
+               return makeTimeMarshaler(getMarshalInfo(t))
+       }
+
+       if isDuration {
+               if pointer {
+                       if slice {
+                               return makeDurationPtrSliceMarshaler(getMarshalInfo(t))
+                       }
+                       return makeDurationPtrMarshaler(getMarshalInfo(t))
+               }
+               if slice {
+                       return makeDurationSliceMarshaler(getMarshalInfo(t))
+               }
+               return makeDurationMarshaler(getMarshalInfo(t))
+       }
+
+       if isWktPointer {
+               switch t.Kind() {
+               case reflect.Float64:
+                       if pointer {
+                               if slice {
+                                       return makeStdDoubleValuePtrSliceMarshaler(getMarshalInfo(t))
+                               }
+                               return makeStdDoubleValuePtrMarshaler(getMarshalInfo(t))
+                       }
+                       if slice {
+                               return makeStdDoubleValueSliceMarshaler(getMarshalInfo(t))
+                       }
+                       return makeStdDoubleValueMarshaler(getMarshalInfo(t))
+               case reflect.Float32:
+                       if pointer {
+                               if slice {
+                                       return makeStdFloatValuePtrSliceMarshaler(getMarshalInfo(t))
+                               }
+                               return makeStdFloatValuePtrMarshaler(getMarshalInfo(t))
+                       }
+                       if slice {
+                               return makeStdFloatValueSliceMarshaler(getMarshalInfo(t))
+                       }
+                       return makeStdFloatValueMarshaler(getMarshalInfo(t))
+               case reflect.Int64:
+                       if pointer {
+                               if slice {
+                                       return makeStdInt64ValuePtrSliceMarshaler(getMarshalInfo(t))
+                               }
+                               return makeStdInt64ValuePtrMarshaler(getMarshalInfo(t))
+                       }
+                       if slice {
+                               return makeStdInt64ValueSliceMarshaler(getMarshalInfo(t))
+                       }
+                       return makeStdInt64ValueMarshaler(getMarshalInfo(t))
+               case reflect.Uint64:
+                       if pointer {
+                               if slice {
+                                       return makeStdUInt64ValuePtrSliceMarshaler(getMarshalInfo(t))
+                               }
+                               return makeStdUInt64ValuePtrMarshaler(getMarshalInfo(t))
+                       }
+                       if slice {
+                               return makeStdUInt64ValueSliceMarshaler(getMarshalInfo(t))
+                       }
+                       return makeStdUInt64ValueMarshaler(getMarshalInfo(t))
+               case reflect.Int32:
+                       if pointer {
+                               if slice {
+                                       return makeStdInt32ValuePtrSliceMarshaler(getMarshalInfo(t))
+                               }
+                               return makeStdInt32ValuePtrMarshaler(getMarshalInfo(t))
+                       }
+                       if slice {
+                               return makeStdInt32ValueSliceMarshaler(getMarshalInfo(t))
+                       }
+                       return makeStdInt32ValueMarshaler(getMarshalInfo(t))
+               case reflect.Uint32:
+                       if pointer {
+                               if slice {
+                                       return makeStdUInt32ValuePtrSliceMarshaler(getMarshalInfo(t))
+                               }
+                               return makeStdUInt32ValuePtrMarshaler(getMarshalInfo(t))
+                       }
+                       if slice {
+                               return makeStdUInt32ValueSliceMarshaler(getMarshalInfo(t))
+                       }
+                       return makeStdUInt32ValueMarshaler(getMarshalInfo(t))
+               case reflect.Bool:
+                       if pointer {
+                               if slice {
+                                       return makeStdBoolValuePtrSliceMarshaler(getMarshalInfo(t))
+                               }
+                               return makeStdBoolValuePtrMarshaler(getMarshalInfo(t))
+                       }
+                       if slice {
+                               return makeStdBoolValueSliceMarshaler(getMarshalInfo(t))
+                       }
+                       return makeStdBoolValueMarshaler(getMarshalInfo(t))
+               case reflect.String:
+                       if pointer {
+                               if slice {
+                                       return makeStdStringValuePtrSliceMarshaler(getMarshalInfo(t))
+                               }
+                               return makeStdStringValuePtrMarshaler(getMarshalInfo(t))
+                       }
+                       if slice {
+                               return makeStdStringValueSliceMarshaler(getMarshalInfo(t))
+                       }
+                       return makeStdStringValueMarshaler(getMarshalInfo(t))
+               case uint8SliceType:
+                       if pointer {
+                               if slice {
+                                       return makeStdBytesValuePtrSliceMarshaler(getMarshalInfo(t))
+                               }
+                               return makeStdBytesValuePtrMarshaler(getMarshalInfo(t))
+                       }
+                       if slice {
+                               return makeStdBytesValueSliceMarshaler(getMarshalInfo(t))
+                       }
+                       return makeStdBytesValueMarshaler(getMarshalInfo(t))
+               default:
+                       panic(fmt.Sprintf("unknown wktpointer type %#v", t))
+               }
+       }
+
+       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 pointer {
+                               if slice {
+                                       return makeMessageSliceMarshaler(getMarshalInfo(t))
+                               }
+                               return makeMessageMarshaler(getMarshalInfo(t))
+                       } else {
+                               if slice {
+                                       return makeMessageRefSliceMarshaler(getMarshalInfo(t))
+                               }
+                               return makeMessageRefMarshaler(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()
+       tags := strings.Split(f.Tag.Get("protobuf"), ",")
+       keyTags := strings.Split(f.Tag.Get("protobuf_key"), ",")
+       valTags := strings.Split(f.Tag.Get("protobuf_val"), ",")
+       stdOptions := false
+       for _, t := range tags {
+               if strings.HasPrefix(t, "customtype=") {
+                       valTags = append(valTags, t)
+               }
+               if t == "stdtime" {
+                       valTags = append(valTags, t)
+                       stdOptions = true
+               }
+               if t == "stdduration" {
+                       valTags = append(valTags, t)
+                       stdOptions = true
+               }
+               if t == "wktptr" {
+                       valTags = append(valTags, t)
+               }
+       }
+       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 && !stdOptions && 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 p.deterministic {
+               if _, ok := pb.(Marshaler); ok {
+                       return fmt.Errorf("proto: deterministic not supported by the Marshal method of %T", pb)
+               }
+       }
+       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.
+               var b []byte
+               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...)
+}