encoding/prototext/encode.go - protobuf - Git at Google

 // Copyright 2018 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 prototext

 import (
 	"fmt"
 	"sort"
 	"unicode/utf8"

 	"google.golang.org/protobuf/internal/encoding/messageset"
 	"google.golang.org/protobuf/internal/encoding/text"
 	"google.golang.org/protobuf/internal/encoding/wire"
 	"google.golang.org/protobuf/internal/errors"
 	"google.golang.org/protobuf/internal/fieldnum"
 	"google.golang.org/protobuf/internal/flags"
 	"google.golang.org/protobuf/internal/mapsort"
 	"google.golang.org/protobuf/internal/pragma"
 	"google.golang.org/protobuf/proto"
 	pref "google.golang.org/protobuf/reflect/protoreflect"
 	"google.golang.org/protobuf/reflect/protoregistry"
 )

 // Marshal writes the given proto.Message in textproto format using default options.
 func Marshal(m proto.Message) ([]byte, error) {
 	return MarshalOptions{}.Marshal(m)
 }

 // MarshalOptions is a configurable text format marshaler.
 type MarshalOptions struct {
 	pragma.NoUnkeyedLiterals

 	// AllowPartial allows messages that have missing required fields to marshal
 	// without returning an error. If AllowPartial is false (the default),
 	// Marshal will return error if there are any missing required fields.
 	AllowPartial bool

 	// If Indent is a non-empty string, it causes entries for a Message to be
 	// preceded by the indent and trailed by a newline. Indent can only be
 	// composed of space or tab characters.
 	Indent string

 	// Resolver is used for looking up types when expanding google.protobuf.Any
 	// messages. If nil, this defaults to using protoregistry.GlobalTypes.
 	Resolver interface {
 		protoregistry.ExtensionTypeResolver
 		protoregistry.MessageTypeResolver
 	}
 }

 // Marshal writes the given proto.Message in textproto format using options in MarshalOptions object.
 func (o MarshalOptions) Marshal(m proto.Message) ([]byte, error) {
 	if o.Resolver == nil {
 		o.Resolver = protoregistry.GlobalTypes
 	}

 	v, err := o.marshalMessage(m.ProtoReflect())
 	if err != nil {
 		return nil, err
 	}

 	delims := [2]byte{'{', '}'}
 	const outputASCII = false
 	b, err := text.Marshal(v, o.Indent, delims, outputASCII)
 	if err != nil {
 		return nil, err
 	}
 	if o.AllowPartial {
 		return b, nil
 	}
 	return b, proto.IsInitialized(m)
 }

 // marshalMessage converts a protoreflect.Message to a text.Value.
 func (o MarshalOptions) marshalMessage(m pref.Message) (text.Value, error) {
 	messageDesc := m.Descriptor()
 	if !flags.ProtoLegacy && messageset.IsMessageSet(messageDesc) {
 		return text.Value{}, errors.New("no support for proto1 MessageSets")
 	}

 	// Handle Any expansion.
 	if messageDesc.FullName() == "google.protobuf.Any" {
 		if msg, err := o.marshalAny(m); err == nil {
 			// Return as is if no error.
 			return msg, nil
 		}
 		// Otherwise continue on to marshal Any as a regular message.
 	}

 	// Handle known fields.
 	var msgFields [][2]text.Value
 	fieldDescs := messageDesc.Fields()
 	size := fieldDescs.Len()
 	for i := 0; i < size; i++ {
 		fd := fieldDescs.Get(i)
 		if !m.Has(fd) {
 			continue
 		}

 		name := text.ValueOf(fd.Name())
 		// Use type name for group field name.
 		if fd.Kind() == pref.GroupKind {
 			name = text.ValueOf(fd.Message().Name())
 		}
 		pval := m.Get(fd)
 		var err error
 		msgFields, err = o.appendField(msgFields, name, pval, fd)
 		if err != nil {
 			return text.Value{}, err
 		}
 	}

 	// Handle extensions.
 	var err error
 	msgFields, err = o.appendExtensions(msgFields, m)
 	if err != nil {
 		return text.Value{}, err
 	}

 	// Handle unknown fields.
 	// TODO: Provide option to exclude or include unknown fields.
 	msgFields = appendUnknown(msgFields, m.GetUnknown())

 	return text.ValueOf(msgFields), nil
 }

 // appendField marshals a protoreflect.Value and appends it to the given [][2]text.Value.
 func (o MarshalOptions) appendField(msgFields [][2]text.Value, name text.Value, pval pref.Value, fd pref.FieldDescriptor) ([][2]text.Value, error) {
 	switch {
 	case fd.IsList():
 		items, err := o.marshalList(pval.List(), fd)
 		if err != nil {
 			return msgFields, err
 		}

 		for _, item := range items {
 			msgFields = append(msgFields, [2]text.Value{name, item})
 		}
 	case fd.IsMap():
 		items, err := o.marshalMap(pval.Map(), fd)
 		if err != nil {
 			return msgFields, err
 		}

 		for _, item := range items {
 			msgFields = append(msgFields, [2]text.Value{name, item})
 		}
 	default:
 		tval, err := o.marshalSingular(pval, fd)
 		if err != nil {
 			return msgFields, err
 		}
 		msgFields = append(msgFields, [2]text.Value{name, tval})
 	}

 	return msgFields, nil
 }

 // marshalSingular converts a non-repeated field value to text.Value.
 // This includes all scalar types, enums, messages, and groups.
 func (o MarshalOptions) marshalSingular(val pref.Value, fd pref.FieldDescriptor) (text.Value, error) {
 	kind := fd.Kind()
 	switch kind {
 	case pref.BoolKind,
 		pref.Int32Kind, pref.Sint32Kind, pref.Uint32Kind,
 		pref.Int64Kind, pref.Sint64Kind, pref.Uint64Kind,
 		pref.Sfixed32Kind, pref.Fixed32Kind,
 		pref.Sfixed64Kind, pref.Fixed64Kind,
 		pref.FloatKind, pref.DoubleKind,
 		pref.BytesKind:
 		return text.ValueOf(val.Interface()), nil

 	case pref.StringKind:
 		s := val.String()
 		if !utf8.ValidString(s) {
 			return text.Value{}, errors.InvalidUTF8(string(fd.FullName()))
 		}
 		return text.ValueOf(s), nil

 	case pref.EnumKind:
 		num := val.Enum()
 		if desc := fd.Enum().Values().ByNumber(num); desc != nil {
 			return text.ValueOf(desc.Name()), nil
 		}
 		// Use numeric value if there is no enum description.
 		return text.ValueOf(int32(num)), nil

 	case pref.MessageKind, pref.GroupKind:
 		return o.marshalMessage(val.Message())
 	}

 	panic(fmt.Sprintf("%v has unknown kind: %v", fd.FullName(), kind))
 }

 // marshalList converts a protoreflect.List to []text.Value.
 func (o MarshalOptions) marshalList(list pref.List, fd pref.FieldDescriptor) ([]text.Value, error) {
 	size := list.Len()
 	values := make([]text.Value, 0, size)

 	for i := 0; i < size; i++ {
 		item := list.Get(i)
 		val, err := o.marshalSingular(item, fd)
 		if err != nil {
 			// Return already marshaled values.
 			return values, err
 		}
 		values = append(values, val)
 	}

 	return values, nil
 }

 var (
 	mapKeyName   = text.ValueOf(pref.Name("key"))
 	mapValueName = text.ValueOf(pref.Name("value"))
 )

 // marshalMap converts a protoreflect.Map to []text.Value.
 func (o MarshalOptions) marshalMap(mmap pref.Map, fd pref.FieldDescriptor) ([]text.Value, error) {
 	// values is a list of messages.
 	values := make([]text.Value, 0, mmap.Len())

 	var err error
 	mapsort.Range(mmap, fd.MapKey().Kind(), func(key pref.MapKey, val pref.Value) bool {
 		var keyTxtVal text.Value
 		keyTxtVal, err = o.marshalSingular(key.Value(), fd.MapKey())
 		if err != nil {
 			return false
 		}
 		var valTxtVal text.Value
 		valTxtVal, err = o.marshalSingular(val, fd.MapValue())
 		if err != nil {
 			return false
 		}
 		// Map entry (message) contains 2 fields, first field for key and second field for value.
 		msg := text.ValueOf([][2]text.Value{
 			{mapKeyName, keyTxtVal},
 			{mapValueName, valTxtVal},
 		})
 		values = append(values, msg)
 		err = nil
 		return true
 	})
 	if err != nil {
 		return nil, err
 	}

 	return values, nil
 }

 // appendExtensions marshals extension fields and appends them to the given [][2]text.Value.
 func (o MarshalOptions) appendExtensions(msgFields [][2]text.Value, m pref.Message) ([][2]text.Value, error) {
 	var err error
 	var entries [][2]text.Value
 	m.Range(func(fd pref.FieldDescriptor, v pref.Value) bool {
 		if !fd.IsExtension() {
 			return true
 		}

 		// For MessageSet extensions, the name used is the parent message.
 		name := fd.FullName()
 		if messageset.IsMessageSetExtension(fd) {
 			name = name.Parent()
 		}

 		// Use string type to produce [name] format.
 		tname := text.ValueOf(string(name))
 		entries, err = o.appendField(entries, tname, v, fd)
 		if err != nil {
 			return false
 		}
 		err = nil
 		return true
 	})
 	if err != nil {
 		return msgFields, err
 	}

 	// Sort extensions lexicographically and append to output.
 	sort.SliceStable(entries, func(i, j int) bool {
 		return entries[i][0].String() < entries[j][0].String()
 	})
 	return append(msgFields, entries...), nil
 }

 // appendUnknown parses the given []byte and appends field(s) into the given fields slice.
 // This function assumes proper encoding in the given []byte.
 func appendUnknown(fields [][2]text.Value, b []byte) [][2]text.Value {
 	for len(b) > 0 {
 		var value interface{}
 		num, wtype, n := wire.ConsumeTag(b)
 		b = b[n:]

 		switch wtype {
 		case wire.VarintType:
 			value, n = wire.ConsumeVarint(b)
 		case wire.Fixed32Type:
 			value, n = wire.ConsumeFixed32(b)
 		case wire.Fixed64Type:
 			value, n = wire.ConsumeFixed64(b)
 		case wire.BytesType:
 			value, n = wire.ConsumeBytes(b)
 		case wire.StartGroupType:
 			var v []byte
 			v, n = wire.ConsumeGroup(num, b)
 			var msg [][2]text.Value
 			value = appendUnknown(msg, v)
 		default:
 			panic(fmt.Sprintf("error parsing unknown field wire type: %v", wtype))
 		}

 		fields = append(fields, [2]text.Value{text.ValueOf(uint32(num)), text.ValueOf(value)})
 		b = b[n:]
 	}
 	return fields
 }

 // marshalAny converts a google.protobuf.Any protoreflect.Message to a text.Value.
 func (o MarshalOptions) marshalAny(m pref.Message) (text.Value, error) {
 	fds := m.Descriptor().Fields()
 	fdType := fds.ByNumber(fieldnum.Any_TypeUrl)
 	fdValue := fds.ByNumber(fieldnum.Any_Value)

 	typeURL := m.Get(fdType).String()
 	value := m.Get(fdValue)

 	emt, err := o.Resolver.FindMessageByURL(typeURL)
 	if err != nil {
 		return text.Value{}, err
 	}
 	em := emt.New().Interface()
 	err = proto.UnmarshalOptions{
 		AllowPartial: true,
 		Resolver:     o.Resolver,
 	}.Unmarshal(value.Bytes(), em)
 	if err != nil {
 		return text.Value{}, err
 	}

 	msg, err := o.marshalMessage(em.ProtoReflect())
 	if err != nil {
 		return text.Value{}, err
 	}
 	// Expanded Any field value contains only a single field with the type_url field value as the
 	// field name in [] and a text marshaled field value of the embedded message.
 	msgFields := [][2]text.Value{
 		{
 			text.ValueOf(typeURL),
 			msg,
 		},
 	}
 	return text.ValueOf(msgFields), nil
 }
	// Copyright 2018 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 prototext

	import (
	"fmt"
	"sort"
	"unicode/utf8"

	"google.golang.org/protobuf/internal/encoding/messageset"
	"google.golang.org/protobuf/internal/encoding/text"
	"google.golang.org/protobuf/internal/encoding/wire"
	"google.golang.org/protobuf/internal/errors"
	"google.golang.org/protobuf/internal/fieldnum"
	"google.golang.org/protobuf/internal/flags"
	"google.golang.org/protobuf/internal/mapsort"
	"google.golang.org/protobuf/internal/pragma"
	"google.golang.org/protobuf/proto"
	pref "google.golang.org/protobuf/reflect/protoreflect"
	"google.golang.org/protobuf/reflect/protoregistry"
	)

	// Marshal writes the given proto.Message in textproto format using default options.
	func Marshal(m proto.Message) ([]byte, error) {
	return MarshalOptions{}.Marshal(m)
	}

	// MarshalOptions is a configurable text format marshaler.
	type MarshalOptions struct {
	pragma.NoUnkeyedLiterals

	// AllowPartial allows messages that have missing required fields to marshal
	// without returning an error. If AllowPartial is false (the default),
	// Marshal will return error if there are any missing required fields.
	AllowPartial bool

	// If Indent is a non-empty string, it causes entries for a Message to be
	// preceded by the indent and trailed by a newline. Indent can only be
	// composed of space or tab characters.
	Indent string

	// Resolver is used for looking up types when expanding google.protobuf.Any
	// messages. If nil, this defaults to using protoregistry.GlobalTypes.
	Resolver interface {
	protoregistry.ExtensionTypeResolver
	protoregistry.MessageTypeResolver
	}
	}

	// Marshal writes the given proto.Message in textproto format using options in MarshalOptions object.
	func (o MarshalOptions) Marshal(m proto.Message) ([]byte, error) {
	if o.Resolver == nil {
	o.Resolver = protoregistry.GlobalTypes
	}

	v, err := o.marshalMessage(m.ProtoReflect())
	if err != nil {
	return nil, err
	}

	delims := [2]byte{'{', '}'}
	const outputASCII = false
	b, err := text.Marshal(v, o.Indent, delims, outputASCII)
	if err != nil {
	return nil, err
	}
	if o.AllowPartial {
	return b, nil
	}
	return b, proto.IsInitialized(m)
	}

	// marshalMessage converts a protoreflect.Message to a text.Value.
	func (o MarshalOptions) marshalMessage(m pref.Message) (text.Value, error) {
	messageDesc := m.Descriptor()
	if !flags.ProtoLegacy && messageset.IsMessageSet(messageDesc) {
	return text.Value{}, errors.New("no support for proto1 MessageSets")
	}

	// Handle Any expansion.
	if messageDesc.FullName() == "google.protobuf.Any" {
	if msg, err := o.marshalAny(m); err == nil {
	// Return as is if no error.
	return msg, nil
	}
	// Otherwise continue on to marshal Any as a regular message.
	}

	// Handle known fields.
	var msgFields [][2]text.Value
	fieldDescs := messageDesc.Fields()
	size := fieldDescs.Len()
	for i := 0; i < size; i++ {
	fd := fieldDescs.Get(i)
	if !m.Has(fd) {
	continue
	}

	name := text.ValueOf(fd.Name())
	// Use type name for group field name.
	if fd.Kind() == pref.GroupKind {
	name = text.ValueOf(fd.Message().Name())
	}
	pval := m.Get(fd)
	var err error
	msgFields, err = o.appendField(msgFields, name, pval, fd)
	if err != nil {
	return text.Value{}, err
	}
	}

	// Handle extensions.
	var err error
	msgFields, err = o.appendExtensions(msgFields, m)
	if err != nil {
	return text.Value{}, err
	}

	// Handle unknown fields.
	// TODO: Provide option to exclude or include unknown fields.
	msgFields = appendUnknown(msgFields, m.GetUnknown())

	return text.ValueOf(msgFields), nil
	}

	// appendField marshals a protoreflect.Value and appends it to the given [][2]text.Value.
	func (o MarshalOptions) appendField(msgFields [][2]text.Value, name text.Value, pval pref.Value, fd pref.FieldDescriptor) ([][2]text.Value, error) {
	switch {
	case fd.IsList():
	items, err := o.marshalList(pval.List(), fd)
	if err != nil {
	return msgFields, err
	}

	for _, item := range items {
	msgFields = append(msgFields, [2]text.Value{name, item})
	}
	case fd.IsMap():
	items, err := o.marshalMap(pval.Map(), fd)
	if err != nil {
	return msgFields, err
	}

	for _, item := range items {
	msgFields = append(msgFields, [2]text.Value{name, item})
	}
	default:
	tval, err := o.marshalSingular(pval, fd)
	if err != nil {
	return msgFields, err
	}
	msgFields = append(msgFields, [2]text.Value{name, tval})
	}

	return msgFields, nil
	}

	// marshalSingular converts a non-repeated field value to text.Value.
	// This includes all scalar types, enums, messages, and groups.
	func (o MarshalOptions) marshalSingular(val pref.Value, fd pref.FieldDescriptor) (text.Value, error) {
	kind := fd.Kind()
	switch kind {
	case pref.BoolKind,
	pref.Int32Kind, pref.Sint32Kind, pref.Uint32Kind,
	pref.Int64Kind, pref.Sint64Kind, pref.Uint64Kind,
	pref.Sfixed32Kind, pref.Fixed32Kind,
	pref.Sfixed64Kind, pref.Fixed64Kind,
	pref.FloatKind, pref.DoubleKind,
	pref.BytesKind:
	return text.ValueOf(val.Interface()), nil

	case pref.StringKind:
	s := val.String()
	if !utf8.ValidString(s) {
	return text.Value{}, errors.InvalidUTF8(string(fd.FullName()))
	}
	return text.ValueOf(s), nil

	case pref.EnumKind:
	num := val.Enum()
	if desc := fd.Enum().Values().ByNumber(num); desc != nil {
	return text.ValueOf(desc.Name()), nil
	}
	// Use numeric value if there is no enum description.
	return text.ValueOf(int32(num)), nil

	case pref.MessageKind, pref.GroupKind:
	return o.marshalMessage(val.Message())
	}

	panic(fmt.Sprintf("%v has unknown kind: %v", fd.FullName(), kind))
	}

	// marshalList converts a protoreflect.List to []text.Value.
	func (o MarshalOptions) marshalList(list pref.List, fd pref.FieldDescriptor) ([]text.Value, error) {
	size := list.Len()
	values := make([]text.Value, 0, size)

	for i := 0; i < size; i++ {
	item := list.Get(i)
	val, err := o.marshalSingular(item, fd)
	if err != nil {
	// Return already marshaled values.
	return values, err
	}
	values = append(values, val)
	}

	return values, nil
	}

	var (
	mapKeyName = text.ValueOf(pref.Name("key"))
	mapValueName = text.ValueOf(pref.Name("value"))
	)

	// marshalMap converts a protoreflect.Map to []text.Value.
	func (o MarshalOptions) marshalMap(mmap pref.Map, fd pref.FieldDescriptor) ([]text.Value, error) {
	// values is a list of messages.
	values := make([]text.Value, 0, mmap.Len())

	var err error
	mapsort.Range(mmap, fd.MapKey().Kind(), func(key pref.MapKey, val pref.Value) bool {
	var keyTxtVal text.Value
	keyTxtVal, err = o.marshalSingular(key.Value(), fd.MapKey())
	if err != nil {
	return false
	}
	var valTxtVal text.Value
	valTxtVal, err = o.marshalSingular(val, fd.MapValue())
	if err != nil {
	return false
	}
	// Map entry (message) contains 2 fields, first field for key and second field for value.
	msg := text.ValueOf([][2]text.Value{
	{mapKeyName, keyTxtVal},
	{mapValueName, valTxtVal},
	})
	values = append(values, msg)
	err = nil
	return true
	})
	if err != nil {
	return nil, err
	}

	return values, nil
	}

	// appendExtensions marshals extension fields and appends them to the given [][2]text.Value.
	func (o MarshalOptions) appendExtensions(msgFields [][2]text.Value, m pref.Message) ([][2]text.Value, error) {
	var err error
	var entries [][2]text.Value
	m.Range(func(fd pref.FieldDescriptor, v pref.Value) bool {
	if !fd.IsExtension() {
	return true
	}

	// For MessageSet extensions, the name used is the parent message.
	name := fd.FullName()
	if messageset.IsMessageSetExtension(fd) {
	name = name.Parent()
	}

	// Use string type to produce [name] format.
	tname := text.ValueOf(string(name))
	entries, err = o.appendField(entries, tname, v, fd)
	if err != nil {
	return false
	}
	err = nil
	return true
	})
	if err != nil {
	return msgFields, err
	}

	// Sort extensions lexicographically and append to output.
	sort.SliceStable(entries, func(i, j int) bool {
	return entries[i][0].String() < entries[j][0].String()
	})
	return append(msgFields, entries...), nil
	}

	// appendUnknown parses the given []byte and appends field(s) into the given fields slice.
	// This function assumes proper encoding in the given []byte.
	func appendUnknown(fields [][2]text.Value, b []byte) [][2]text.Value {
	for len(b) > 0 {
	var value interface{}
	num, wtype, n := wire.ConsumeTag(b)
	b = b[n:]

	switch wtype {
	case wire.VarintType:
	value, n = wire.ConsumeVarint(b)
	case wire.Fixed32Type:
	value, n = wire.ConsumeFixed32(b)
	case wire.Fixed64Type:
	value, n = wire.ConsumeFixed64(b)
	case wire.BytesType:
	value, n = wire.ConsumeBytes(b)
	case wire.StartGroupType:
	var v []byte
	v, n = wire.ConsumeGroup(num, b)
	var msg [][2]text.Value
	value = appendUnknown(msg, v)
	default:
	panic(fmt.Sprintf("error parsing unknown field wire type: %v", wtype))
	}

	fields = append(fields, [2]text.Value{text.ValueOf(uint32(num)), text.ValueOf(value)})
	b = b[n:]
	}
	return fields
	}

	// marshalAny converts a google.protobuf.Any protoreflect.Message to a text.Value.
	func (o MarshalOptions) marshalAny(m pref.Message) (text.Value, error) {
	fds := m.Descriptor().Fields()
	fdType := fds.ByNumber(fieldnum.Any_TypeUrl)
	fdValue := fds.ByNumber(fieldnum.Any_Value)

	typeURL := m.Get(fdType).String()
	value := m.Get(fdValue)

	emt, err := o.Resolver.FindMessageByURL(typeURL)
	if err != nil {
	return text.Value{}, err
	}
	em := emt.New().Interface()
	err = proto.UnmarshalOptions{
	AllowPartial: true,
	Resolver: o.Resolver,
	}.Unmarshal(value.Bytes(), em)
	if err != nil {
	return text.Value{}, err
	}

	msg, err := o.marshalMessage(em.ProtoReflect())
	if err != nil {
	return text.Value{}, err
	}
	// Expanded Any field value contains only a single field with the type_url field value as the
	// field name in [] and a text marshaled field value of the embedded message.
	msgFields := [][2]text.Value{
	{
	text.ValueOf(typeURL),
	msg,
	},
	}
	return text.ValueOf(msgFields), nil
	}