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

 // Copyright 2019 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 protojson

 import (
 	"encoding/base64"
 	"fmt"

 	"google.golang.org/protobuf/internal/encoding/json"
 	"google.golang.org/protobuf/internal/encoding/messageset"
 	"google.golang.org/protobuf/internal/errors"
 	"google.golang.org/protobuf/internal/filedesc"
 	"google.golang.org/protobuf/internal/flags"
 	"google.golang.org/protobuf/internal/genid"
 	"google.golang.org/protobuf/internal/order"
 	"google.golang.org/protobuf/internal/pragma"
 	"google.golang.org/protobuf/proto"
 	"google.golang.org/protobuf/reflect/protoreflect"
 	pref "google.golang.org/protobuf/reflect/protoreflect"
 	"google.golang.org/protobuf/reflect/protoregistry"
 )

 const defaultIndent = "  "

 // Format formats the message as a multiline string.
 // This function is only intended for human consumption and ignores errors.
 // Do not depend on the output being stable. It may change over time across
 // different versions of the program.
 func Format(m proto.Message) string {
 	return MarshalOptions{Multiline: true}.Format(m)
 }

 // Marshal writes the given proto.Message in JSON format using default options.
 // Do not depend on the output being stable. It may change over time across
 // different versions of the program.
 func Marshal(m proto.Message) ([]byte, error) {
 	return MarshalOptions{}.Marshal(m)
 }

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

 	// Multiline specifies whether the marshaler should format the output in
 	// indented-form with every textual element on a new line.
 	// If Indent is an empty string, then an arbitrary indent is chosen.
 	Multiline bool

 	// Indent specifies the set of indentation characters to use in a multiline
 	// formatted output such that every entry is preceded by Indent and
 	// terminated by a newline. If non-empty, then Multiline is treated as true.
 	// Indent can only be composed of space or tab characters.
 	Indent string

 	// 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

 	// UseProtoNames uses proto field name instead of lowerCamelCase name in JSON
 	// field names.
 	UseProtoNames bool

 	// UseEnumNumbers emits enum values as numbers.
 	UseEnumNumbers bool

 	// EmitUnpopulated specifies whether to emit unpopulated fields. It does not
 	// emit unpopulated oneof fields or unpopulated extension fields.
 	// The JSON value emitted for unpopulated fields are as follows:
 	//  ╔═══════╤════════════════════════════╗
 	//  ║ JSON  │ Protobuf field             ║
 	//  ╠═══════╪════════════════════════════╣
 	//  ║ false │ proto3 boolean fields      ║
 	//  ║ 0     │ proto3 numeric fields      ║
 	//  ║ ""    │ proto3 string/bytes fields ║
 	//  ║ null  │ proto2 scalar fields       ║
 	//  ║ null  │ message fields             ║
 	//  ║ []    │ list fields                ║
 	//  ║ {}    │ map fields                 ║
 	//  ╚═══════╧════════════════════════════╝
 	EmitUnpopulated bool

 	// 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
 	}
 }

 // Format formats the message as a string.
 // This method is only intended for human consumption and ignores errors.
 // Do not depend on the output being stable. It may change over time across
 // different versions of the program.
 func (o MarshalOptions) Format(m proto.Message) string {
 	if m == nil || !m.ProtoReflect().IsValid() {
 		return "<nil>" // invalid syntax, but okay since this is for debugging
 	}
 	o.AllowPartial = true
 	b, _ := o.Marshal(m)
 	return string(b)
 }

 // Marshal marshals the given proto.Message in the JSON format using options in
 // MarshalOptions. Do not depend on the output being stable. It may change over
 // time across different versions of the program.
 func (o MarshalOptions) Marshal(m proto.Message) ([]byte, error) {
 	return o.marshal(m)
 }

 // marshal is a centralized function that all marshal operations go through.
 // For profiling purposes, avoid changing the name of this function or
 // introducing other code paths for marshal that do not go through this.
 func (o MarshalOptions) marshal(m proto.Message) ([]byte, error) {
 	if o.Multiline && o.Indent == "" {
 		o.Indent = defaultIndent
 	}
 	if o.Resolver == nil {
 		o.Resolver = protoregistry.GlobalTypes
 	}

 	internalEnc, err := json.NewEncoder(o.Indent)
 	if err != nil {
 		return nil, err
 	}

 	// Treat nil message interface as an empty message,
 	// in which case the output in an empty JSON object.
 	if m == nil {
 		return []byte("{}"), nil
 	}

 	enc := encoder{internalEnc, o}
 	if err := enc.marshalMessage(m.ProtoReflect(), ""); err != nil {
 		return nil, err
 	}
 	if o.AllowPartial {
 		return enc.Bytes(), nil
 	}
 	return enc.Bytes(), proto.CheckInitialized(m)
 }

 type encoder struct {
 	*json.Encoder
 	opts MarshalOptions
 }

 // typeFieldDesc is a synthetic field descriptor used for the "@type" field.
 var typeFieldDesc = func() protoreflect.FieldDescriptor {
 	var fd filedesc.Field
 	fd.L0.FullName = "@type"
 	fd.L0.Index = -1
 	fd.L1.Cardinality = protoreflect.Optional
 	fd.L1.Kind = protoreflect.StringKind
 	return &fd
 }()

 // typeURLFieldRanger wraps a protoreflect.Message and modifies its Range method
 // to additionally iterate over a synthetic field for the type URL.
 type typeURLFieldRanger struct {
 	order.FieldRanger
 	typeURL string
 }

 func (m typeURLFieldRanger) Range(f func(pref.FieldDescriptor, pref.Value) bool) {
 	if !f(typeFieldDesc, pref.ValueOfString(m.typeURL)) {
 		return
 	}
 	m.FieldRanger.Range(f)
 }

 // unpopulatedFieldRanger wraps a protoreflect.Message and modifies its Range
 // method to additionally iterate over unpopulated fields.
 type unpopulatedFieldRanger struct{ pref.Message }

 func (m unpopulatedFieldRanger) Range(f func(pref.FieldDescriptor, pref.Value) bool) {
 	fds := m.Descriptor().Fields()
 	for i := 0; i < fds.Len(); i++ {
 		fd := fds.Get(i)
 		if m.Has(fd) || fd.ContainingOneof() != nil {
 			continue // ignore populated fields and fields within a oneofs
 		}

 		v := m.Get(fd)
 		isProto2Scalar := fd.Syntax() == pref.Proto2 && fd.Default().IsValid()
 		isSingularMessage := fd.Cardinality() != pref.Repeated && fd.Message() != nil
 		if isProto2Scalar || isSingularMessage {
 			v = pref.Value{} // use invalid value to emit null
 		}
 		if !f(fd, v) {
 			return
 		}
 	}
 	m.Message.Range(f)
 }

 // marshalMessage marshals the fields in the given protoreflect.Message.
 // If the typeURL is non-empty, then a synthetic "@type" field is injected
 // containing the URL as the value.
 func (e encoder) marshalMessage(m pref.Message, typeURL string) error {
 	if !flags.ProtoLegacy && messageset.IsMessageSet(m.Descriptor()) {
 		return errors.New("no support for proto1 MessageSets")
 	}

 	if marshal := wellKnownTypeMarshaler(m.Descriptor().FullName()); marshal != nil {
 		return marshal(e, m)
 	}

 	e.StartObject()
 	defer e.EndObject()

 	var fields order.FieldRanger = m
 	if e.opts.EmitUnpopulated {
 		fields = unpopulatedFieldRanger{m}
 	}
 	if typeURL != "" {
 		fields = typeURLFieldRanger{fields, typeURL}
 	}

 	var err error
 	order.RangeFields(fields, order.IndexNameFieldOrder, func(fd pref.FieldDescriptor, v pref.Value) bool {
 		name := fd.JSONName()
 		if e.opts.UseProtoNames {
 			name = fd.TextName()
 		}

 		if err = e.WriteName(name); err != nil {
 			return false
 		}
 		if err = e.marshalValue(v, fd); err != nil {
 			return false
 		}
 		return true
 	})
 	return err
 }

 // marshalValue marshals the given protoreflect.Value.
 func (e encoder) marshalValue(val pref.Value, fd pref.FieldDescriptor) error {
 	switch {
 	case fd.IsList():
 		return e.marshalList(val.List(), fd)
 	case fd.IsMap():
 		return e.marshalMap(val.Map(), fd)
 	default:
 		return e.marshalSingular(val, fd)
 	}
 }

 // marshalSingular marshals the given non-repeated field value. This includes
 // all scalar types, enums, messages, and groups.
 func (e encoder) marshalSingular(val pref.Value, fd pref.FieldDescriptor) error {
 	if !val.IsValid() {
 		e.WriteNull()
 		return nil
 	}

 	switch kind := fd.Kind(); kind {
 	case pref.BoolKind:
 		e.WriteBool(val.Bool())

 	case pref.StringKind:
 		if e.WriteString(val.String()) != nil {
 			return errors.InvalidUTF8(string(fd.FullName()))
 		}

 	case pref.Int32Kind, pref.Sint32Kind, pref.Sfixed32Kind:
 		e.WriteInt(val.Int())

 	case pref.Uint32Kind, pref.Fixed32Kind:
 		e.WriteUint(val.Uint())

 	case pref.Int64Kind, pref.Sint64Kind, pref.Uint64Kind,
 		pref.Sfixed64Kind, pref.Fixed64Kind:
 		// 64-bit integers are written out as JSON string.
 		e.WriteString(val.String())

 	case pref.FloatKind:
 		// Encoder.WriteFloat handles the special numbers NaN and infinites.
 		e.WriteFloat(val.Float(), 32)

 	case pref.DoubleKind:
 		// Encoder.WriteFloat handles the special numbers NaN and infinites.
 		e.WriteFloat(val.Float(), 64)

 	case pref.BytesKind:
 		e.WriteString(base64.StdEncoding.EncodeToString(val.Bytes()))

 	case pref.EnumKind:
 		if fd.Enum().FullName() == genid.NullValue_enum_fullname {
 			e.WriteNull()
 		} else {
 			desc := fd.Enum().Values().ByNumber(val.Enum())
 			if e.opts.UseEnumNumbers || desc == nil {
 				e.WriteInt(int64(val.Enum()))
 			} else {
 				e.WriteString(string(desc.Name()))
 			}
 		}

 	case pref.MessageKind, pref.GroupKind:
 		if err := e.marshalMessage(val.Message(), ""); err != nil {
 			return err
 		}

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

 // marshalList marshals the given protoreflect.List.
 func (e encoder) marshalList(list pref.List, fd pref.FieldDescriptor) error {
 	e.StartArray()
 	defer e.EndArray()

 	for i := 0; i < list.Len(); i++ {
 		item := list.Get(i)
 		if err := e.marshalSingular(item, fd); err != nil {
 			return err
 		}
 	}
 	return nil
 }

 // marshalMap marshals given protoreflect.Map.
 func (e encoder) marshalMap(mmap pref.Map, fd pref.FieldDescriptor) error {
 	e.StartObject()
 	defer e.EndObject()

 	var err error
 	order.RangeEntries(mmap, order.GenericKeyOrder, func(k pref.MapKey, v pref.Value) bool {
 		if err = e.WriteName(k.String()); err != nil {
 			return false
 		}
 		if err = e.marshalSingular(v, fd.MapValue()); err != nil {
 			return false
 		}
 		return true
 	})
 	return err
 }
	// Copyright 2019 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 protojson

	import (
	"encoding/base64"
	"fmt"

	"google.golang.org/protobuf/internal/encoding/json"
	"google.golang.org/protobuf/internal/encoding/messageset"
	"google.golang.org/protobuf/internal/errors"
	"google.golang.org/protobuf/internal/filedesc"
	"google.golang.org/protobuf/internal/flags"
	"google.golang.org/protobuf/internal/genid"
	"google.golang.org/protobuf/internal/order"
	"google.golang.org/protobuf/internal/pragma"
	"google.golang.org/protobuf/proto"
	"google.golang.org/protobuf/reflect/protoreflect"
	pref "google.golang.org/protobuf/reflect/protoreflect"
	"google.golang.org/protobuf/reflect/protoregistry"
	)

	const defaultIndent = " "

	// Format formats the message as a multiline string.
	// This function is only intended for human consumption and ignores errors.
	// Do not depend on the output being stable. It may change over time across
	// different versions of the program.
	func Format(m proto.Message) string {
	return MarshalOptions{Multiline: true}.Format(m)
	}

	// Marshal writes the given proto.Message in JSON format using default options.
	// Do not depend on the output being stable. It may change over time across
	// different versions of the program.
	func Marshal(m proto.Message) ([]byte, error) {
	return MarshalOptions{}.Marshal(m)
	}

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

	// Multiline specifies whether the marshaler should format the output in
	// indented-form with every textual element on a new line.
	// If Indent is an empty string, then an arbitrary indent is chosen.
	Multiline bool

	// Indent specifies the set of indentation characters to use in a multiline
	// formatted output such that every entry is preceded by Indent and
	// terminated by a newline. If non-empty, then Multiline is treated as true.
	// Indent can only be composed of space or tab characters.
	Indent string

	// 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

	// UseProtoNames uses proto field name instead of lowerCamelCase name in JSON
	// field names.
	UseProtoNames bool

	// UseEnumNumbers emits enum values as numbers.
	UseEnumNumbers bool

	// EmitUnpopulated specifies whether to emit unpopulated fields. It does not
	// emit unpopulated oneof fields or unpopulated extension fields.
	// The JSON value emitted for unpopulated fields are as follows:
	// ╔═══════╤════════════════════════════╗
	// ║ JSON │ Protobuf field ║
	// ╠═══════╪════════════════════════════╣
	// ║ false │ proto3 boolean fields ║
	// ║ 0 │ proto3 numeric fields ║
	// ║ "" │ proto3 string/bytes fields ║
	// ║ null │ proto2 scalar fields ║
	// ║ null │ message fields ║
	// ║ [] │ list fields ║
	// ║ {} │ map fields ║
	// ╚═══════╧════════════════════════════╝
	EmitUnpopulated bool

	// 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
	}
	}

	// Format formats the message as a string.
	// This method is only intended for human consumption and ignores errors.
	// Do not depend on the output being stable. It may change over time across
	// different versions of the program.
	func (o MarshalOptions) Format(m proto.Message) string {
	if m == nil \|\| !m.ProtoReflect().IsValid() {
	return "<nil>" // invalid syntax, but okay since this is for debugging
	}
	o.AllowPartial = true
	b, _ := o.Marshal(m)
	return string(b)
	}

	// Marshal marshals the given proto.Message in the JSON format using options in
	// MarshalOptions. Do not depend on the output being stable. It may change over
	// time across different versions of the program.
	func (o MarshalOptions) Marshal(m proto.Message) ([]byte, error) {
	return o.marshal(m)
	}

	// marshal is a centralized function that all marshal operations go through.
	// For profiling purposes, avoid changing the name of this function or
	// introducing other code paths for marshal that do not go through this.
	func (o MarshalOptions) marshal(m proto.Message) ([]byte, error) {
	if o.Multiline && o.Indent == "" {
	o.Indent = defaultIndent
	}
	if o.Resolver == nil {
	o.Resolver = protoregistry.GlobalTypes
	}

	internalEnc, err := json.NewEncoder(o.Indent)
	if err != nil {
	return nil, err
	}

	// Treat nil message interface as an empty message,
	// in which case the output in an empty JSON object.
	if m == nil {
	return []byte("{}"), nil
	}

	enc := encoder{internalEnc, o}
	if err := enc.marshalMessage(m.ProtoReflect(), ""); err != nil {
	return nil, err
	}
	if o.AllowPartial {
	return enc.Bytes(), nil
	}
	return enc.Bytes(), proto.CheckInitialized(m)
	}

	type encoder struct {
	*json.Encoder
	opts MarshalOptions
	}

	// typeFieldDesc is a synthetic field descriptor used for the "@type" field.
	var typeFieldDesc = func() protoreflect.FieldDescriptor {
	var fd filedesc.Field
	fd.L0.FullName = "@type"
	fd.L0.Index = -1
	fd.L1.Cardinality = protoreflect.Optional
	fd.L1.Kind = protoreflect.StringKind
	return &fd
	}()

	// typeURLFieldRanger wraps a protoreflect.Message and modifies its Range method
	// to additionally iterate over a synthetic field for the type URL.
	type typeURLFieldRanger struct {
	order.FieldRanger
	typeURL string
	}

	func (m typeURLFieldRanger) Range(f func(pref.FieldDescriptor, pref.Value) bool) {
	if !f(typeFieldDesc, pref.ValueOfString(m.typeURL)) {
	return
	}
	m.FieldRanger.Range(f)
	}

	// unpopulatedFieldRanger wraps a protoreflect.Message and modifies its Range
	// method to additionally iterate over unpopulated fields.
	type unpopulatedFieldRanger struct{ pref.Message }

	func (m unpopulatedFieldRanger) Range(f func(pref.FieldDescriptor, pref.Value) bool) {
	fds := m.Descriptor().Fields()
	for i := 0; i < fds.Len(); i++ {
	fd := fds.Get(i)
	if m.Has(fd) \|\| fd.ContainingOneof() != nil {
	continue // ignore populated fields and fields within a oneofs
	}

	v := m.Get(fd)
	isProto2Scalar := fd.Syntax() == pref.Proto2 && fd.Default().IsValid()
	isSingularMessage := fd.Cardinality() != pref.Repeated && fd.Message() != nil
	if isProto2Scalar \|\| isSingularMessage {
	v = pref.Value{} // use invalid value to emit null
	}
	if !f(fd, v) {
	return
	}
	}
	m.Message.Range(f)
	}

	// marshalMessage marshals the fields in the given protoreflect.Message.
	// If the typeURL is non-empty, then a synthetic "@type" field is injected
	// containing the URL as the value.
	func (e encoder) marshalMessage(m pref.Message, typeURL string) error {
	if !flags.ProtoLegacy && messageset.IsMessageSet(m.Descriptor()) {
	return errors.New("no support for proto1 MessageSets")
	}

	if marshal := wellKnownTypeMarshaler(m.Descriptor().FullName()); marshal != nil {
	return marshal(e, m)
	}

	e.StartObject()
	defer e.EndObject()

	var fields order.FieldRanger = m
	if e.opts.EmitUnpopulated {
	fields = unpopulatedFieldRanger{m}
	}
	if typeURL != "" {
	fields = typeURLFieldRanger{fields, typeURL}
	}

	var err error
	order.RangeFields(fields, order.IndexNameFieldOrder, func(fd pref.FieldDescriptor, v pref.Value) bool {
	name := fd.JSONName()
	if e.opts.UseProtoNames {
	name = fd.TextName()
	}

	if err = e.WriteName(name); err != nil {
	return false
	}
	if err = e.marshalValue(v, fd); err != nil {
	return false
	}
	return true
	})
	return err
	}

	// marshalValue marshals the given protoreflect.Value.
	func (e encoder) marshalValue(val pref.Value, fd pref.FieldDescriptor) error {
	switch {
	case fd.IsList():
	return e.marshalList(val.List(), fd)
	case fd.IsMap():
	return e.marshalMap(val.Map(), fd)
	default:
	return e.marshalSingular(val, fd)
	}
	}

	// marshalSingular marshals the given non-repeated field value. This includes
	// all scalar types, enums, messages, and groups.
	func (e encoder) marshalSingular(val pref.Value, fd pref.FieldDescriptor) error {
	if !val.IsValid() {
	e.WriteNull()
	return nil
	}

	switch kind := fd.Kind(); kind {
	case pref.BoolKind:
	e.WriteBool(val.Bool())

	case pref.StringKind:
	if e.WriteString(val.String()) != nil {
	return errors.InvalidUTF8(string(fd.FullName()))
	}

	case pref.Int32Kind, pref.Sint32Kind, pref.Sfixed32Kind:
	e.WriteInt(val.Int())

	case pref.Uint32Kind, pref.Fixed32Kind:
	e.WriteUint(val.Uint())

	case pref.Int64Kind, pref.Sint64Kind, pref.Uint64Kind,
	pref.Sfixed64Kind, pref.Fixed64Kind:
	// 64-bit integers are written out as JSON string.
	e.WriteString(val.String())

	case pref.FloatKind:
	// Encoder.WriteFloat handles the special numbers NaN and infinites.
	e.WriteFloat(val.Float(), 32)

	case pref.DoubleKind:
	// Encoder.WriteFloat handles the special numbers NaN and infinites.
	e.WriteFloat(val.Float(), 64)

	case pref.BytesKind:
	e.WriteString(base64.StdEncoding.EncodeToString(val.Bytes()))

	case pref.EnumKind:
	if fd.Enum().FullName() == genid.NullValue_enum_fullname {
	e.WriteNull()
	} else {
	desc := fd.Enum().Values().ByNumber(val.Enum())
	if e.opts.UseEnumNumbers \|\| desc == nil {
	e.WriteInt(int64(val.Enum()))
	} else {
	e.WriteString(string(desc.Name()))
	}
	}

	case pref.MessageKind, pref.GroupKind:
	if err := e.marshalMessage(val.Message(), ""); err != nil {
	return err
	}

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

	// marshalList marshals the given protoreflect.List.
	func (e encoder) marshalList(list pref.List, fd pref.FieldDescriptor) error {
	e.StartArray()
	defer e.EndArray()

	for i := 0; i < list.Len(); i++ {
	item := list.Get(i)
	if err := e.marshalSingular(item, fd); err != nil {
	return err
	}
	}
	return nil
	}

	// marshalMap marshals given protoreflect.Map.
	func (e encoder) marshalMap(mmap pref.Map, fd pref.FieldDescriptor) error {
	e.StartObject()
	defer e.EndObject()

	var err error
	order.RangeEntries(mmap, order.GenericKeyOrder, func(k pref.MapKey, v pref.Value) bool {
	if err = e.WriteName(k.String()); err != nil {
	return false
	}
	if err = e.marshalSingular(v, fd.MapValue()); err != nil {
	return false
	}
	return true
	})
	return err
	}