Migrate to containerd 1.54

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

vendor/github.com/golang/protobuf/proto/properties.go

@@ -1,162 +1,104 @@
-// Go support for Protocol Buffers - Google's data interchange format
-//
-// Copyright 2010 The Go Authors.  All rights reserved.
-// https://github.com/golang/protobuf
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
 
 package proto
 
-/*
- * Routines for encoding data into the wire format for protocol buffers.
- */
-
 import (
 	"fmt"
-	"log"
 	"reflect"
-	"sort"
 	"strconv"
 	"strings"
 	"sync"
+
+	"google.golang.org/protobuf/reflect/protoreflect"
+	"google.golang.org/protobuf/runtime/protoimpl"
 )
 
-const debug bool = false
-
-// Constants that identify the encoding of a value on the wire.
-const (
-	WireVarint     = 0
-	WireFixed64    = 1
-	WireBytes      = 2
-	WireStartGroup = 3
-	WireEndGroup   = 4
-	WireFixed32    = 5
-)
-
-// tagMap is an optimization over map[int]int for typical protocol buffer
-// use-cases. Encoded protocol buffers are often in tag order with small tag
-// numbers.
-type tagMap struct {
-	fastTags []int
-	slowTags map[int]int
-}
-
-// tagMapFastLimit is the upper bound on the tag number that will be stored in
-// the tagMap slice rather than its map.
-const tagMapFastLimit = 1024
-
-func (p *tagMap) get(t int) (int, bool) {
-	if t > 0 && t < tagMapFastLimit {
-		if t >= len(p.fastTags) {
-			return 0, false
-		}
-		fi := p.fastTags[t]
-		return fi, fi >= 0
-	}
-	fi, ok := p.slowTags[t]
-	return fi, ok
-}
-
-func (p *tagMap) put(t int, fi int) {
-	if t > 0 && t < tagMapFastLimit {
-		for len(p.fastTags) < t+1 {
-			p.fastTags = append(p.fastTags, -1)
-		}
-		p.fastTags[t] = fi
-		return
-	}
-	if p.slowTags == nil {
-		p.slowTags = make(map[int]int)
-	}
-	p.slowTags[t] = fi
-}
-
-// StructProperties represents properties for all the fields of a struct.
-// decoderTags and decoderOrigNames should only be used by the decoder.
+// StructProperties represents protocol buffer type information for a
+// generated protobuf message in the open-struct API.
+//
+// Deprecated: Do not use.
 type StructProperties struct {
-	Prop             []*Properties  // properties for each field
-	reqCount         int            // required count
-	decoderTags      tagMap         // map from proto tag to struct field number
-	decoderOrigNames map[string]int // map from original name to struct field number
-	order            []int          // list of struct field numbers in tag order
+	// Prop are the properties for each field.
+	//
+	// Fields belonging to a oneof are stored in OneofTypes instead, with a
+	// single Properties representing the parent oneof held here.
+	//
+	// The order of Prop matches the order of fields in the Go struct.
+	// Struct fields that are not related to protobufs have a "XXX_" prefix
+	// in the Properties.Name and must be ignored by the user.
+	Prop []*Properties
 
 	// OneofTypes contains information about the oneof fields in this message.
-	// It is keyed by the original name of a field.
+	// It is keyed by the protobuf field name.
 	OneofTypes map[string]*OneofProperties
 }
 
-// OneofProperties represents information about a specific field in a oneof.
-type OneofProperties struct {
-	Type  reflect.Type // pointer to generated struct type for this oneof field
-	Field int          // struct field number of the containing oneof in the message
-	Prop  *Properties
-}
-
-// Implement the sorting interface so we can sort the fields in tag order, as recommended by the spec.
-// See encode.go, (*Buffer).enc_struct.
-
-func (sp *StructProperties) Len() int { return len(sp.order) }
-func (sp *StructProperties) Less(i, j int) bool {
-	return sp.Prop[sp.order[i]].Tag < sp.Prop[sp.order[j]].Tag
-}
-func (sp *StructProperties) Swap(i, j int) { sp.order[i], sp.order[j] = sp.order[j], sp.order[i] }
-
-// Properties represents the protocol-specific behavior of a single struct field.
+// Properties represents the type information for a protobuf message field.
+//
+// Deprecated: Do not use.
 type Properties struct {
-	Name     string // name of the field, for error messages
-	OrigName string // original name before protocol compiler (always set)
-	JSONName string // name to use for JSON; determined by protoc
-	Wire     string
+	// Name is a placeholder name with little meaningful semantic value.
+	// If the name has an "XXX_" prefix, the entire Properties must be ignored.
+	Name string
+	// OrigName is the protobuf field name or oneof name.
+	OrigName string
+	// JSONName is the JSON name for the protobuf field.
+	JSONName string
+	// Enum is a placeholder name for enums.
+	// For historical reasons, this is neither the Go name for the enum,
+	// nor the protobuf name for the enum.
+	Enum string // Deprecated: Do not use.
+	// Weak contains the full name of the weakly referenced message.
+	Weak string
+	// Wire is a string representation of the wire type.
+	Wire string
+	// WireType is the protobuf wire type for the field.
 	WireType int
-	Tag      int
+	// Tag is the protobuf field number.
+	Tag int
+	// Required reports whether this is a required field.
 	Required bool
+	// Optional reports whether this is a optional field.
 	Optional bool
+	// Repeated reports whether this is a repeated field.
 	Repeated bool
-	Packed   bool   // relevant for repeated primitives only
-	Enum     string // set for enum types only
-	proto3   bool   // whether this is known to be a proto3 field
-	oneof    bool   // whether this is a oneof field
+	// Packed reports whether this is a packed repeated field of scalars.
+	Packed bool
+	// Proto3 reports whether this field operates under the proto3 syntax.
+	Proto3 bool
+	// Oneof reports whether this field belongs within a oneof.
+	Oneof bool
 
-	Default    string // default value
-	HasDefault bool   // whether an explicit default was provided
+	// Default is the default value in string form.
+	Default string
+	// HasDefault reports whether the field has a default value.
+	HasDefault bool
 
-	stype reflect.Type      // set for struct types only
-	sprop *StructProperties // set for struct types only
+	// MapKeyProp is the properties for the key field for a map field.
+	MapKeyProp *Properties
+	// MapValProp is the properties for the value field for a map field.
+	MapValProp *Properties
+}
 
-	mtype      reflect.Type // set for map types only
-	MapKeyProp *Properties  // set for map types only
-	MapValProp *Properties  // set for map types only
+// OneofProperties represents the type information for a protobuf oneof.
+//
+// Deprecated: Do not use.
+type OneofProperties struct {
+	// Type is a pointer to the generated wrapper type for the field value.
+	// This is nil for messages that are not in the open-struct API.
+	Type reflect.Type
+	// Field is the index into StructProperties.Prop for the containing oneof.
+	Field int
+	// Prop is the properties for the field.
+	Prop *Properties
 }
 
 // String formats the properties in the protobuf struct field tag style.
 func (p *Properties) String() string {
 	s := p.Wire
-	s += ","
-	s += strconv.Itoa(p.Tag)
+	s += "," + strconv.Itoa(p.Tag)
 	if p.Required {
 		s += ",req"
 	}
@@ -170,18 +112,21 @@ func (p *Properties) String() string {
 		s += ",packed"
 	}
 	s += ",name=" + p.OrigName
-	if p.JSONName != p.OrigName {
+	if p.JSONName != "" {
 		s += ",json=" + p.JSONName
 	}
-	if p.proto3 {
-		s += ",proto3"
-	}
-	if p.oneof {
-		s += ",oneof"
-	}
 	if len(p.Enum) > 0 {
 		s += ",enum=" + p.Enum
 	}
+	if len(p.Weak) > 0 {
+		s += ",weak=" + p.Weak
+	}
+	if p.Proto3 {
+		s += ",proto3"
+	}
+	if p.Oneof {
+		s += ",oneof"
+	}
 	if p.HasDefault {
 		s += ",def=" + p.Default
 	}
@@ -189,356 +134,173 @@ func (p *Properties) String() string {
 }
 
 // Parse populates p by parsing a string in the protobuf struct field tag style.
-func (p *Properties) Parse(s string) {
-	// "bytes,49,opt,name=foo,def=hello!"
-	fields := strings.Split(s, ",") // breaks def=, but handled below.
-	if len(fields) < 2 {
-		log.Printf("proto: tag has too few fields: %q", s)
-		return
-	}
-
-	p.Wire = fields[0]
-	switch p.Wire {
-	case "varint":
-		p.WireType = WireVarint
-	case "fixed32":
-		p.WireType = WireFixed32
-	case "fixed64":
-		p.WireType = WireFixed64
-	case "zigzag32":
-		p.WireType = WireVarint
-	case "zigzag64":
-		p.WireType = WireVarint
-	case "bytes", "group":
-		p.WireType = WireBytes
-		// no numeric converter for non-numeric types
-	default:
-		log.Printf("proto: tag has unknown wire type: %q", s)
-		return
-	}
-
-	var err error
-	p.Tag, err = strconv.Atoi(fields[1])
-	if err != nil {
-		return
-	}
-
-outer:
-	for i := 2; i < len(fields); i++ {
-		f := fields[i]
-		switch {
-		case f == "req":
-			p.Required = true
-		case f == "opt":
+func (p *Properties) Parse(tag string) {
+	// For example: "bytes,49,opt,name=foo,def=hello!"
+	for len(tag) > 0 {
+		i := strings.IndexByte(tag, ',')
+		if i < 0 {
+			i = len(tag)
+		}
+		switch s := tag[:i]; {
+		case strings.HasPrefix(s, "name="):
+			p.OrigName = s[len("name="):]
+		case strings.HasPrefix(s, "json="):
+			p.JSONName = s[len("json="):]
+		case strings.HasPrefix(s, "enum="):
+			p.Enum = s[len("enum="):]
+		case strings.HasPrefix(s, "weak="):
+			p.Weak = s[len("weak="):]
+		case strings.Trim(s, "0123456789") == "":
+			n, _ := strconv.ParseUint(s, 10, 32)
+			p.Tag = int(n)
+		case s == "opt":
 			p.Optional = true
-		case f == "rep":
+		case s == "req":
+			p.Required = true
+		case s == "rep":
 			p.Repeated = true
-		case f == "packed":
+		case s == "varint" || s == "zigzag32" || s == "zigzag64":
+			p.Wire = s
+			p.WireType = WireVarint
+		case s == "fixed32":
+			p.Wire = s
+			p.WireType = WireFixed32
+		case s == "fixed64":
+			p.Wire = s
+			p.WireType = WireFixed64
+		case s == "bytes":
+			p.Wire = s
+			p.WireType = WireBytes
+		case s == "group":
+			p.Wire = s
+			p.WireType = WireStartGroup
+		case s == "packed":
 			p.Packed = true
-		case strings.HasPrefix(f, "name="):
-			p.OrigName = f[5:]
-		case strings.HasPrefix(f, "json="):
-			p.JSONName = f[5:]
-		case strings.HasPrefix(f, "enum="):
-			p.Enum = f[5:]
-		case f == "proto3":
-			p.proto3 = true
-		case f == "oneof":
-			p.oneof = true
-		case strings.HasPrefix(f, "def="):
+		case s == "proto3":
+			p.Proto3 = true
+		case s == "oneof":
+			p.Oneof = true
+		case strings.HasPrefix(s, "def="):
+			// The default tag is special in that everything afterwards is the
+			// default regardless of the presence of commas.
 			p.HasDefault = true
-			p.Default = f[4:] // rest of string
-			if i+1 < len(fields) {
-				// Commas aren't escaped, and def is always last.
-				p.Default += "," + strings.Join(fields[i+1:], ",")
-				break outer
-			}
+			p.Default, i = tag[len("def="):], len(tag)
 		}
+		tag = strings.TrimPrefix(tag[i:], ",")
 	}
 }
 
-var protoMessageType = reflect.TypeOf((*Message)(nil)).Elem()
-
-// setFieldProps initializes the field properties for submessages and maps.
-func (p *Properties) setFieldProps(typ reflect.Type, f *reflect.StructField, lockGetProp bool) {
-	switch t1 := typ; t1.Kind() {
-	case reflect.Ptr:
-		if t1.Elem().Kind() == reflect.Struct {
-			p.stype = t1.Elem()
-		}
-
-	case reflect.Slice:
-		if t2 := t1.Elem(); t2.Kind() == reflect.Ptr && t2.Elem().Kind() == reflect.Struct {
-			p.stype = t2.Elem()
-		}
-
-	case reflect.Map:
-		p.mtype = t1
-		p.MapKeyProp = &Properties{}
-		p.MapKeyProp.init(reflect.PtrTo(p.mtype.Key()), "Key", f.Tag.Get("protobuf_key"), nil, lockGetProp)
-		p.MapValProp = &Properties{}
-		vtype := p.mtype.Elem()
-		if vtype.Kind() != reflect.Ptr && vtype.Kind() != reflect.Slice {
-			// The value type is not a message (*T) or bytes ([]byte),
-			// so we need encoders for the pointer to this type.
-			vtype = reflect.PtrTo(vtype)
-		}
-		p.MapValProp.init(vtype, "Value", f.Tag.Get("protobuf_val"), nil, lockGetProp)
-	}
-
-	if p.stype != nil {
-		if lockGetProp {
-			p.sprop = GetProperties(p.stype)
-		} else {
-			p.sprop = getPropertiesLocked(p.stype)
-		}
-	}
-}
-
-var (
-	marshalerType = reflect.TypeOf((*Marshaler)(nil)).Elem()
-)
-
 // Init populates the properties from a protocol buffer struct tag.
+//
+// Deprecated: Do not use.
 func (p *Properties) Init(typ reflect.Type, name, tag string, f *reflect.StructField) {
-	p.init(typ, name, tag, f, true)
-}
-
-func (p *Properties) init(typ reflect.Type, name, tag string, f *reflect.StructField, lockGetProp bool) {
-	// "bytes,49,opt,def=hello!"
 	p.Name = name
 	p.OrigName = name
 	if tag == "" {
 		return
 	}
 	p.Parse(tag)
-	p.setFieldProps(typ, f, lockGetProp)
+
+	if typ != nil && typ.Kind() == reflect.Map {
+		p.MapKeyProp = new(Properties)
+		p.MapKeyProp.Init(nil, "Key", f.Tag.Get("protobuf_key"), nil)
+		p.MapValProp = new(Properties)
+		p.MapValProp.Init(nil, "Value", f.Tag.Get("protobuf_val"), nil)
+	}
 }
 
-var (
-	propertiesMu  sync.RWMutex
-	propertiesMap = make(map[reflect.Type]*StructProperties)
-)
+var propertiesCache sync.Map // map[reflect.Type]*StructProperties
 
-// GetProperties returns the list of properties for the type represented by t.
-// t must represent a generated struct type of a protocol message.
+// GetProperties returns the list of properties for the type represented by t,
+// which must be a generated protocol buffer message in the open-struct API,
+// where protobuf message fields are represented by exported Go struct fields.
+//
+// Deprecated: Use protobuf reflection instead.
 func GetProperties(t reflect.Type) *StructProperties {
-	if t.Kind() != reflect.Struct {
-		panic("proto: type must have kind struct")
+	if p, ok := propertiesCache.Load(t); ok {
+		return p.(*StructProperties)
 	}
-
-	// Most calls to GetProperties in a long-running program will be
-	// retrieving details for types we have seen before.
-	propertiesMu.RLock()
-	sprop, ok := propertiesMap[t]
-	propertiesMu.RUnlock()
-	if ok {
-		return sprop
-	}
-
-	propertiesMu.Lock()
-	sprop = getPropertiesLocked(t)
-	propertiesMu.Unlock()
-	return sprop
+	p, _ := propertiesCache.LoadOrStore(t, newProperties(t))
+	return p.(*StructProperties)
 }
 
-type (
-	oneofFuncsIface interface {
-		XXX_OneofFuncs() (func(Message, *Buffer) error, func(Message, int, int, *Buffer) (bool, error), func(Message) int, []interface{})
-	}
-	oneofWrappersIface interface {
-		XXX_OneofWrappers() []interface{}
-	}
-)
-
-// getPropertiesLocked requires that propertiesMu is held.
-func getPropertiesLocked(t reflect.Type) *StructProperties {
-	if prop, ok := propertiesMap[t]; ok {
-		return prop
+func newProperties(t reflect.Type) *StructProperties {
+	if t.Kind() != reflect.Struct {
+		panic(fmt.Sprintf("%v is not a generated message in the open-struct API", t))
 	}
 
+	var hasOneof bool
 	prop := new(StructProperties)
-	// in case of recursive protos, fill this in now.
-	propertiesMap[t] = prop
-
-	// build properties
-	prop.Prop = make([]*Properties, t.NumField())
-	prop.order = make([]int, t.NumField())
 
+	// Construct a list of properties for each field in the struct.
 	for i := 0; i < t.NumField(); i++ {
-		f := t.Field(i)
 		p := new(Properties)
-		name := f.Name
-		p.init(f.Type, name, f.Tag.Get("protobuf"), &f, false)
+		f := t.Field(i)
+		tagField := f.Tag.Get("protobuf")
+		p.Init(f.Type, f.Name, tagField, &f)
 
-		oneof := f.Tag.Get("protobuf_oneof") // special case
-		if oneof != "" {
-			// Oneof fields don't use the traditional protobuf tag.
-			p.OrigName = oneof
+		tagOneof := f.Tag.Get("protobuf_oneof")
+		if tagOneof != "" {
+			hasOneof = true
+			p.OrigName = tagOneof
 		}
-		prop.Prop[i] = p
-		prop.order[i] = i
-		if debug {
-			print(i, " ", f.Name, " ", t.String(), " ")
-			if p.Tag > 0 {
-				print(p.String())
+
+		// Rename unrelated struct fields with the "XXX_" prefix since so much
+		// user code simply checks for this to exclude special fields.
+		if tagField == "" && tagOneof == "" && !strings.HasPrefix(p.Name, "XXX_") {
+			p.Name = "XXX_" + p.Name
+			p.OrigName = "XXX_" + p.OrigName
+		} else if p.Weak != "" {
+			p.Name = p.OrigName // avoid possible "XXX_" prefix on weak field
+		}
+
+		prop.Prop = append(prop.Prop, p)
+	}
+
+	// Construct a mapping of oneof field names to properties.
+	if hasOneof {
+		var oneofWrappers []interface{}
+		if fn, ok := reflect.PtrTo(t).MethodByName("XXX_OneofFuncs"); ok {
+			oneofWrappers = fn.Func.Call([]reflect.Value{reflect.Zero(fn.Type.In(0))})[3].Interface().([]interface{})
+		}
+		if fn, ok := reflect.PtrTo(t).MethodByName("XXX_OneofWrappers"); ok {
+			oneofWrappers = fn.Func.Call([]reflect.Value{reflect.Zero(fn.Type.In(0))})[0].Interface().([]interface{})
+		}
+		if m, ok := reflect.Zero(reflect.PtrTo(t)).Interface().(protoreflect.ProtoMessage); ok {
+			if m, ok := m.ProtoReflect().(interface{ ProtoMessageInfo() *protoimpl.MessageInfo }); ok {
+				oneofWrappers = m.ProtoMessageInfo().OneofWrappers
 			}
-			print("\n")
 		}
-	}
 
-	// Re-order prop.order.
-	sort.Sort(prop)
-
-	var oots []interface{}
-	switch m := reflect.Zero(reflect.PtrTo(t)).Interface().(type) {
-	case oneofFuncsIface:
-		_, _, _, oots = m.XXX_OneofFuncs()
-	case oneofWrappersIface:
-		oots = m.XXX_OneofWrappers()
-	}
-	if len(oots) > 0 {
-		// Interpret oneof metadata.
 		prop.OneofTypes = make(map[string]*OneofProperties)
-		for _, oot := range oots {
-			oop := &OneofProperties{
-				Type: reflect.ValueOf(oot).Type(), // *T
+		for _, wrapper := range oneofWrappers {
+			p := &OneofProperties{
+				Type: reflect.ValueOf(wrapper).Type(), // *T
 				Prop: new(Properties),
 			}
-			sft := oop.Type.Elem().Field(0)
-			oop.Prop.Name = sft.Name
-			oop.Prop.Parse(sft.Tag.Get("protobuf"))
-			// There will be exactly one interface field that
-			// this new value is assignable to.
-			for i := 0; i < t.NumField(); i++ {
-				f := t.Field(i)
-				if f.Type.Kind() != reflect.Interface {
-					continue
-				}
-				if !oop.Type.AssignableTo(f.Type) {
-					continue
-				}
-				oop.Field = i
-				break
-			}
-			prop.OneofTypes[oop.Prop.OrigName] = oop
-		}
-	}
+			f := p.Type.Elem().Field(0)
+			p.Prop.Name = f.Name
+			p.Prop.Parse(f.Tag.Get("protobuf"))
 
-	// build required counts
-	// build tags
-	reqCount := 0
-	prop.decoderOrigNames = make(map[string]int)
-	for i, p := range prop.Prop {
-		if strings.HasPrefix(p.Name, "XXX_") {
-			// Internal fields should not appear in tags/origNames maps.
-			// They are handled specially when encoding and decoding.
-			continue
+			// Determine the struct field that contains this oneof.
+			// Each wrapper is assignable to exactly one parent field.
+			var foundOneof bool
+			for i := 0; i < t.NumField() && !foundOneof; i++ {
+				if p.Type.AssignableTo(t.Field(i).Type) {
+					p.Field = i
+					foundOneof = true
+				}
+			}
+			if !foundOneof {
+				panic(fmt.Sprintf("%v is not a generated message in the open-struct API", t))
+			}
+			prop.OneofTypes[p.Prop.OrigName] = p
 		}
-		if p.Required {
-			reqCount++
-		}
-		prop.decoderTags.put(p.Tag, i)
-		prop.decoderOrigNames[p.OrigName] = i
 	}
-	prop.reqCount = reqCount
 
 	return prop
 }
 
-// A global registry of enum types.
-// The generated code will register the generated maps by calling RegisterEnum.
-
-var enumValueMaps = make(map[string]map[string]int32)
-
-// RegisterEnum is called from the generated code to install the enum descriptor
-// maps into the global table to aid parsing text format protocol buffers.
-func RegisterEnum(typeName string, unusedNameMap map[int32]string, valueMap map[string]int32) {
-	if _, ok := enumValueMaps[typeName]; ok {
-		panic("proto: duplicate enum registered: " + typeName)
-	}
-	enumValueMaps[typeName] = valueMap
-}
-
-// EnumValueMap returns the mapping from names to integers of the
-// enum type enumType, or a nil if not found.
-func EnumValueMap(enumType string) map[string]int32 {
-	return enumValueMaps[enumType]
-}
-
-// A registry of all linked message types.
-// The string is a fully-qualified proto name ("pkg.Message").
-var (
-	protoTypedNils = make(map[string]Message)      // a map from proto names to typed nil pointers
-	protoMapTypes  = make(map[string]reflect.Type) // a map from proto names to map types
-	revProtoTypes  = make(map[reflect.Type]string)
-)
-
-// RegisterType is called from generated code and maps from the fully qualified
-// proto name to the type (pointer to struct) of the protocol buffer.
-func RegisterType(x Message, name string) {
-	if _, ok := protoTypedNils[name]; ok {
-		// TODO: Some day, make this a panic.
-		log.Printf("proto: duplicate proto type registered: %s", name)
-		return
-	}
-	t := reflect.TypeOf(x)
-	if v := reflect.ValueOf(x); v.Kind() == reflect.Ptr && v.Pointer() == 0 {
-		// Generated code always calls RegisterType with nil x.
-		// This check is just for extra safety.
-		protoTypedNils[name] = x
-	} else {
-		protoTypedNils[name] = reflect.Zero(t).Interface().(Message)
-	}
-	revProtoTypes[t] = name
-}
-
-// RegisterMapType is called from generated code and maps from the fully qualified
-// proto name to the native map type of the proto map definition.
-func RegisterMapType(x interface{}, name string) {
-	if reflect.TypeOf(x).Kind() != reflect.Map {
-		panic(fmt.Sprintf("RegisterMapType(%T, %q); want map", x, name))
-	}
-	if _, ok := protoMapTypes[name]; ok {
-		log.Printf("proto: duplicate proto type registered: %s", name)
-		return
-	}
-	t := reflect.TypeOf(x)
-	protoMapTypes[name] = t
-	revProtoTypes[t] = name
-}
-
-// MessageName returns the fully-qualified proto name for the given message type.
-func MessageName(x Message) string {
-	type xname interface {
-		XXX_MessageName() string
-	}
-	if m, ok := x.(xname); ok {
-		return m.XXX_MessageName()
-	}
-	return revProtoTypes[reflect.TypeOf(x)]
-}
-
-// MessageType returns the message type (pointer to struct) for a named message.
-// The type is not guaranteed to implement proto.Message if the name refers to a
-// map entry.
-func MessageType(name string) reflect.Type {
-	if t, ok := protoTypedNils[name]; ok {
-		return reflect.TypeOf(t)
-	}
-	return protoMapTypes[name]
-}
-
-// A registry of all linked proto files.
-var (
-	protoFiles = make(map[string][]byte) // file name => fileDescriptor
-)
-
-// RegisterFile is called from generated code and maps from the
-// full file name of a .proto file to its compressed FileDescriptorProto.
-func RegisterFile(filename string, fileDescriptor []byte) {
-	protoFiles[filename] = fileDescriptor
-}
-
-// FileDescriptor returns the compressed FileDescriptorProto for a .proto file.
-func FileDescriptor(filename string) []byte { return protoFiles[filename] }
+func (sp *StructProperties) Len() int           { return len(sp.Prop) }
+func (sp *StructProperties) Less(i, j int) bool { return false }
+func (sp *StructProperties) Swap(i, j int)      { return }