gtsocial-umbx

decode.go (17716B)

---

 // 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"
 	"math"
 	"strconv"
 	"strings"
 
 	"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/flags"
 	"google.golang.org/protobuf/internal/genid"
 	"google.golang.org/protobuf/internal/pragma"
 	"google.golang.org/protobuf/internal/set"
 	"google.golang.org/protobuf/proto"
 	"google.golang.org/protobuf/reflect/protoreflect"
 	"google.golang.org/protobuf/reflect/protoregistry"
 )
 
 // Unmarshal reads the given []byte into the given proto.Message.
 // The provided message must be mutable (e.g., a non-nil pointer to a message).
 func Unmarshal(b []byte, m proto.Message) error {
 	return UnmarshalOptions{}.Unmarshal(b, m)
 }
 
 // UnmarshalOptions is a configurable JSON format parser.
 type UnmarshalOptions struct {
 	pragma.NoUnkeyedLiterals
 
 	// If AllowPartial is set, input for messages that will result in missing
 	// required fields will not return an error.
 	AllowPartial bool
 
 	// If DiscardUnknown is set, unknown fields are ignored.
 	DiscardUnknown bool
 
 	// Resolver is used for looking up types when unmarshaling
 	// google.protobuf.Any messages or extension fields.
 	// If nil, this defaults to using protoregistry.GlobalTypes.
 	Resolver interface {
 		protoregistry.MessageTypeResolver
 		protoregistry.ExtensionTypeResolver
 	}
 }
 
 // Unmarshal reads the given []byte and populates the given proto.Message
 // using options in the UnmarshalOptions object.
 // It will clear the message first before setting the fields.
 // If it returns an error, the given message may be partially set.
 // The provided message must be mutable (e.g., a non-nil pointer to a message).
 func (o UnmarshalOptions) Unmarshal(b []byte, m proto.Message) error {
 	return o.unmarshal(b, m)
 }
 
 // unmarshal is a centralized function that all unmarshal operations go through.
 // For profiling purposes, avoid changing the name of this function or
 // introducing other code paths for unmarshal that do not go through this.
 func (o UnmarshalOptions) unmarshal(b []byte, m proto.Message) error {
 	proto.Reset(m)
 
 	if o.Resolver == nil {
 		o.Resolver = protoregistry.GlobalTypes
 	}
 
 	dec := decoder{json.NewDecoder(b), o}
 	if err := dec.unmarshalMessage(m.ProtoReflect(), false); err != nil {
 		return err
 	}
 
 	// Check for EOF.
 	tok, err := dec.Read()
 	if err != nil {
 		return err
 	}
 	if tok.Kind() != json.EOF {
 		return dec.unexpectedTokenError(tok)
 	}
 
 	if o.AllowPartial {
 		return nil
 	}
 	return proto.CheckInitialized(m)
 }
 
 type decoder struct {
 	*json.Decoder
 	opts UnmarshalOptions
 }
 
 // newError returns an error object with position info.
 func (d decoder) newError(pos int, f string, x ...interface{}) error {
 	line, column := d.Position(pos)
 	head := fmt.Sprintf("(line %d:%d): ", line, column)
 	return errors.New(head+f, x...)
 }
 
 // unexpectedTokenError returns a syntax error for the given unexpected token.
 func (d decoder) unexpectedTokenError(tok json.Token) error {
 	return d.syntaxError(tok.Pos(), "unexpected token %s", tok.RawString())
 }
 
 // syntaxError returns a syntax error for given position.
 func (d decoder) syntaxError(pos int, f string, x ...interface{}) error {
 	line, column := d.Position(pos)
 	head := fmt.Sprintf("syntax error (line %d:%d): ", line, column)
 	return errors.New(head+f, x...)
 }
 
 // unmarshalMessage unmarshals a message into the given protoreflect.Message.
 func (d decoder) unmarshalMessage(m protoreflect.Message, skipTypeURL bool) error {
 	if unmarshal := wellKnownTypeUnmarshaler(m.Descriptor().FullName()); unmarshal != nil {
 		return unmarshal(d, m)
 	}
 
 	tok, err := d.Read()
 	if err != nil {
 		return err
 	}
 	if tok.Kind() != json.ObjectOpen {
 		return d.unexpectedTokenError(tok)
 	}
 
 	messageDesc := m.Descriptor()
 	if !flags.ProtoLegacy && messageset.IsMessageSet(messageDesc) {
 		return errors.New("no support for proto1 MessageSets")
 	}
 
 	var seenNums set.Ints
 	var seenOneofs set.Ints
 	fieldDescs := messageDesc.Fields()
 	for {
 		// Read field name.
 		tok, err := d.Read()
 		if err != nil {
 			return err
 		}
 		switch tok.Kind() {
 		default:
 			return d.unexpectedTokenError(tok)
 		case json.ObjectClose:
 			return nil
 		case json.Name:
 			// Continue below.
 		}
 
 		name := tok.Name()
 		// Unmarshaling a non-custom embedded message in Any will contain the
 		// JSON field "@type" which should be skipped because it is not a field
 		// of the embedded message, but simply an artifact of the Any format.
 		if skipTypeURL && name == "@type" {
 			d.Read()
 			continue
 		}
 
 		// Get the FieldDescriptor.
 		var fd protoreflect.FieldDescriptor
 		if strings.HasPrefix(name, "[") && strings.HasSuffix(name, "]") {
 			// Only extension names are in [name] format.
 			extName := protoreflect.FullName(name[1 : len(name)-1])
 			extType, err := d.opts.Resolver.FindExtensionByName(extName)
 			if err != nil && err != protoregistry.NotFound {
 				return d.newError(tok.Pos(), "unable to resolve %s: %v", tok.RawString(), err)
 			}
 			if extType != nil {
 				fd = extType.TypeDescriptor()
 				if !messageDesc.ExtensionRanges().Has(fd.Number()) || fd.ContainingMessage().FullName() != messageDesc.FullName() {
 					return d.newError(tok.Pos(), "message %v cannot be extended by %v", messageDesc.FullName(), fd.FullName())
 				}
 			}
 		} else {
 			// The name can either be the JSON name or the proto field name.
 			fd = fieldDescs.ByJSONName(name)
 			if fd == nil {
 				fd = fieldDescs.ByTextName(name)
 			}
 		}
 		if flags.ProtoLegacy {
 			if fd != nil && fd.IsWeak() && fd.Message().IsPlaceholder() {
 				fd = nil // reset since the weak reference is not linked in
 			}
 		}
 
 		if fd == nil {
 			// Field is unknown.
 			if d.opts.DiscardUnknown {
 				if err := d.skipJSONValue(); err != nil {
 					return err
 				}
 				continue
 			}
 			return d.newError(tok.Pos(), "unknown field %v", tok.RawString())
 		}
 
 		// Do not allow duplicate fields.
 		num := uint64(fd.Number())
 		if seenNums.Has(num) {
 			return d.newError(tok.Pos(), "duplicate field %v", tok.RawString())
 		}
 		seenNums.Set(num)
 
 		// No need to set values for JSON null unless the field type is
 		// google.protobuf.Value or google.protobuf.NullValue.
 		if tok, _ := d.Peek(); tok.Kind() == json.Null && !isKnownValue(fd) && !isNullValue(fd) {
 			d.Read()
 			continue
 		}
 
 		switch {
 		case fd.IsList():
 			list := m.Mutable(fd).List()
 			if err := d.unmarshalList(list, fd); err != nil {
 				return err
 			}
 		case fd.IsMap():
 			mmap := m.Mutable(fd).Map()
 			if err := d.unmarshalMap(mmap, fd); err != nil {
 				return err
 			}
 		default:
 			// If field is a oneof, check if it has already been set.
 			if od := fd.ContainingOneof(); od != nil {
 				idx := uint64(od.Index())
 				if seenOneofs.Has(idx) {
 					return d.newError(tok.Pos(), "error parsing %s, oneof %v is already set", tok.RawString(), od.FullName())
 				}
 				seenOneofs.Set(idx)
 			}
 
 			// Required or optional fields.
 			if err := d.unmarshalSingular(m, fd); err != nil {
 				return err
 			}
 		}
 	}
 }
 
 func isKnownValue(fd protoreflect.FieldDescriptor) bool {
 	md := fd.Message()
 	return md != nil && md.FullName() == genid.Value_message_fullname
 }
 
 func isNullValue(fd protoreflect.FieldDescriptor) bool {
 	ed := fd.Enum()
 	return ed != nil && ed.FullName() == genid.NullValue_enum_fullname
 }
 
 // unmarshalSingular unmarshals to the non-repeated field specified
 // by the given FieldDescriptor.
 func (d decoder) unmarshalSingular(m protoreflect.Message, fd protoreflect.FieldDescriptor) error {
 	var val protoreflect.Value
 	var err error
 	switch fd.Kind() {
 	case protoreflect.MessageKind, protoreflect.GroupKind:
 		val = m.NewField(fd)
 		err = d.unmarshalMessage(val.Message(), false)
 	default:
 		val, err = d.unmarshalScalar(fd)
 	}
 
 	if err != nil {
 		return err
 	}
 	m.Set(fd, val)
 	return nil
 }
 
 // unmarshalScalar unmarshals to a scalar/enum protoreflect.Value specified by
 // the given FieldDescriptor.
 func (d decoder) unmarshalScalar(fd protoreflect.FieldDescriptor) (protoreflect.Value, error) {
 	const b32 int = 32
 	const b64 int = 64
 
 	tok, err := d.Read()
 	if err != nil {
 		return protoreflect.Value{}, err
 	}
 
 	kind := fd.Kind()
 	switch kind {
 	case protoreflect.BoolKind:
 		if tok.Kind() == json.Bool {
 			return protoreflect.ValueOfBool(tok.Bool()), nil
 		}
 
 	case protoreflect.Int32Kind, protoreflect.Sint32Kind, protoreflect.Sfixed32Kind:
 		if v, ok := unmarshalInt(tok, b32); ok {
 			return v, nil
 		}
 
 	case protoreflect.Int64Kind, protoreflect.Sint64Kind, protoreflect.Sfixed64Kind:
 		if v, ok := unmarshalInt(tok, b64); ok {
 			return v, nil
 		}
 
 	case protoreflect.Uint32Kind, protoreflect.Fixed32Kind:
 		if v, ok := unmarshalUint(tok, b32); ok {
 			return v, nil
 		}
 
 	case protoreflect.Uint64Kind, protoreflect.Fixed64Kind:
 		if v, ok := unmarshalUint(tok, b64); ok {
 			return v, nil
 		}
 
 	case protoreflect.FloatKind:
 		if v, ok := unmarshalFloat(tok, b32); ok {
 			return v, nil
 		}
 
 	case protoreflect.DoubleKind:
 		if v, ok := unmarshalFloat(tok, b64); ok {
 			return v, nil
 		}
 
 	case protoreflect.StringKind:
 		if tok.Kind() == json.String {
 			return protoreflect.ValueOfString(tok.ParsedString()), nil
 		}
 
 	case protoreflect.BytesKind:
 		if v, ok := unmarshalBytes(tok); ok {
 			return v, nil
 		}
 
 	case protoreflect.EnumKind:
 		if v, ok := unmarshalEnum(tok, fd); ok {
 			return v, nil
 		}
 
 	default:
 		panic(fmt.Sprintf("unmarshalScalar: invalid scalar kind %v", kind))
 	}
 
 	return protoreflect.Value{}, d.newError(tok.Pos(), "invalid value for %v type: %v", kind, tok.RawString())
 }
 
 func unmarshalInt(tok json.Token, bitSize int) (protoreflect.Value, bool) {
 	switch tok.Kind() {
 	case json.Number:
 		return getInt(tok, bitSize)
 
 	case json.String:
 		// Decode number from string.
 		s := strings.TrimSpace(tok.ParsedString())
 		if len(s) != len(tok.ParsedString()) {
 			return protoreflect.Value{}, false
 		}
 		dec := json.NewDecoder([]byte(s))
 		tok, err := dec.Read()
 		if err != nil {
 			return protoreflect.Value{}, false
 		}
 		return getInt(tok, bitSize)
 	}
 	return protoreflect.Value{}, false
 }
 
 func getInt(tok json.Token, bitSize int) (protoreflect.Value, bool) {
 	n, ok := tok.Int(bitSize)
 	if !ok {
 		return protoreflect.Value{}, false
 	}
 	if bitSize == 32 {
 		return protoreflect.ValueOfInt32(int32(n)), true
 	}
 	return protoreflect.ValueOfInt64(n), true
 }
 
 func unmarshalUint(tok json.Token, bitSize int) (protoreflect.Value, bool) {
 	switch tok.Kind() {
 	case json.Number:
 		return getUint(tok, bitSize)
 
 	case json.String:
 		// Decode number from string.
 		s := strings.TrimSpace(tok.ParsedString())
 		if len(s) != len(tok.ParsedString()) {
 			return protoreflect.Value{}, false
 		}
 		dec := json.NewDecoder([]byte(s))
 		tok, err := dec.Read()
 		if err != nil {
 			return protoreflect.Value{}, false
 		}
 		return getUint(tok, bitSize)
 	}
 	return protoreflect.Value{}, false
 }
 
 func getUint(tok json.Token, bitSize int) (protoreflect.Value, bool) {
 	n, ok := tok.Uint(bitSize)
 	if !ok {
 		return protoreflect.Value{}, false
 	}
 	if bitSize == 32 {
 		return protoreflect.ValueOfUint32(uint32(n)), true
 	}
 	return protoreflect.ValueOfUint64(n), true
 }
 
 func unmarshalFloat(tok json.Token, bitSize int) (protoreflect.Value, bool) {
 	switch tok.Kind() {
 	case json.Number:
 		return getFloat(tok, bitSize)
 
 	case json.String:
 		s := tok.ParsedString()
 		switch s {
 		case "NaN":
 			if bitSize == 32 {
 				return protoreflect.ValueOfFloat32(float32(math.NaN())), true
 			}
 			return protoreflect.ValueOfFloat64(math.NaN()), true
 		case "Infinity":
 			if bitSize == 32 {
 				return protoreflect.ValueOfFloat32(float32(math.Inf(+1))), true
 			}
 			return protoreflect.ValueOfFloat64(math.Inf(+1)), true
 		case "-Infinity":
 			if bitSize == 32 {
 				return protoreflect.ValueOfFloat32(float32(math.Inf(-1))), true
 			}
 			return protoreflect.ValueOfFloat64(math.Inf(-1)), true
 		}
 
 		// Decode number from string.
 		if len(s) != len(strings.TrimSpace(s)) {
 			return protoreflect.Value{}, false
 		}
 		dec := json.NewDecoder([]byte(s))
 		tok, err := dec.Read()
 		if err != nil {
 			return protoreflect.Value{}, false
 		}
 		return getFloat(tok, bitSize)
 	}
 	return protoreflect.Value{}, false
 }
 
 func getFloat(tok json.Token, bitSize int) (protoreflect.Value, bool) {
 	n, ok := tok.Float(bitSize)
 	if !ok {
 		return protoreflect.Value{}, false
 	}
 	if bitSize == 32 {
 		return protoreflect.ValueOfFloat32(float32(n)), true
 	}
 	return protoreflect.ValueOfFloat64(n), true
 }
 
 func unmarshalBytes(tok json.Token) (protoreflect.Value, bool) {
 	if tok.Kind() != json.String {
 		return protoreflect.Value{}, false
 	}
 
 	s := tok.ParsedString()
 	enc := base64.StdEncoding
 	if strings.ContainsAny(s, "-_") {
 		enc = base64.URLEncoding
 	}
 	if len(s)%4 != 0 {
 		enc = enc.WithPadding(base64.NoPadding)
 	}
 	b, err := enc.DecodeString(s)
 	if err != nil {
 		return protoreflect.Value{}, false
 	}
 	return protoreflect.ValueOfBytes(b), true
 }
 
 func unmarshalEnum(tok json.Token, fd protoreflect.FieldDescriptor) (protoreflect.Value, bool) {
 	switch tok.Kind() {
 	case json.String:
 		// Lookup EnumNumber based on name.
 		s := tok.ParsedString()
 		if enumVal := fd.Enum().Values().ByName(protoreflect.Name(s)); enumVal != nil {
 			return protoreflect.ValueOfEnum(enumVal.Number()), true
 		}
 
 	case json.Number:
 		if n, ok := tok.Int(32); ok {
 			return protoreflect.ValueOfEnum(protoreflect.EnumNumber(n)), true
 		}
 
 	case json.Null:
 		// This is only valid for google.protobuf.NullValue.
 		if isNullValue(fd) {
 			return protoreflect.ValueOfEnum(0), true
 		}
 	}
 
 	return protoreflect.Value{}, false
 }
 
 func (d decoder) unmarshalList(list protoreflect.List, fd protoreflect.FieldDescriptor) error {
 	tok, err := d.Read()
 	if err != nil {
 		return err
 	}
 	if tok.Kind() != json.ArrayOpen {
 		return d.unexpectedTokenError(tok)
 	}
 
 	switch fd.Kind() {
 	case protoreflect.MessageKind, protoreflect.GroupKind:
 		for {
 			tok, err := d.Peek()
 			if err != nil {
 				return err
 			}
 
 			if tok.Kind() == json.ArrayClose {
 				d.Read()
 				return nil
 			}
 
 			val := list.NewElement()
 			if err := d.unmarshalMessage(val.Message(), false); err != nil {
 				return err
 			}
 			list.Append(val)
 		}
 	default:
 		for {
 			tok, err := d.Peek()
 			if err != nil {
 				return err
 			}
 
 			if tok.Kind() == json.ArrayClose {
 				d.Read()
 				return nil
 			}
 
 			val, err := d.unmarshalScalar(fd)
 			if err != nil {
 				return err
 			}
 			list.Append(val)
 		}
 	}
 
 	return nil
 }
 
 func (d decoder) unmarshalMap(mmap protoreflect.Map, fd protoreflect.FieldDescriptor) error {
 	tok, err := d.Read()
 	if err != nil {
 		return err
 	}
 	if tok.Kind() != json.ObjectOpen {
 		return d.unexpectedTokenError(tok)
 	}
 
 	// Determine ahead whether map entry is a scalar type or a message type in
 	// order to call the appropriate unmarshalMapValue func inside the for loop
 	// below.
 	var unmarshalMapValue func() (protoreflect.Value, error)
 	switch fd.MapValue().Kind() {
 	case protoreflect.MessageKind, protoreflect.GroupKind:
 		unmarshalMapValue = func() (protoreflect.Value, error) {
 			val := mmap.NewValue()
 			if err := d.unmarshalMessage(val.Message(), false); err != nil {
 				return protoreflect.Value{}, err
 			}
 			return val, nil
 		}
 	default:
 		unmarshalMapValue = func() (protoreflect.Value, error) {
 			return d.unmarshalScalar(fd.MapValue())
 		}
 	}
 
 Loop:
 	for {
 		// Read field name.
 		tok, err := d.Read()
 		if err != nil {
 			return err
 		}
 		switch tok.Kind() {
 		default:
 			return d.unexpectedTokenError(tok)
 		case json.ObjectClose:
 			break Loop
 		case json.Name:
 			// Continue.
 		}
 
 		// Unmarshal field name.
 		pkey, err := d.unmarshalMapKey(tok, fd.MapKey())
 		if err != nil {
 			return err
 		}
 
 		// Check for duplicate field name.
 		if mmap.Has(pkey) {
 			return d.newError(tok.Pos(), "duplicate map key %v", tok.RawString())
 		}
 
 		// Read and unmarshal field value.
 		pval, err := unmarshalMapValue()
 		if err != nil {
 			return err
 		}
 
 		mmap.Set(pkey, pval)
 	}
 
 	return nil
 }
 
 // unmarshalMapKey converts given token of Name kind into a protoreflect.MapKey.
 // A map key type is any integral or string type.
 func (d decoder) unmarshalMapKey(tok json.Token, fd protoreflect.FieldDescriptor) (protoreflect.MapKey, error) {
 	const b32 = 32
 	const b64 = 64
 	const base10 = 10
 
 	name := tok.Name()
 	kind := fd.Kind()
 	switch kind {
 	case protoreflect.StringKind:
 		return protoreflect.ValueOfString(name).MapKey(), nil
 
 	case protoreflect.BoolKind:
 		switch name {
 		case "true":
 			return protoreflect.ValueOfBool(true).MapKey(), nil
 		case "false":
 			return protoreflect.ValueOfBool(false).MapKey(), nil
 		}
 
 	case protoreflect.Int32Kind, protoreflect.Sint32Kind, protoreflect.Sfixed32Kind:
 		if n, err := strconv.ParseInt(name, base10, b32); err == nil {
 			return protoreflect.ValueOfInt32(int32(n)).MapKey(), nil
 		}
 
 	case protoreflect.Int64Kind, protoreflect.Sint64Kind, protoreflect.Sfixed64Kind:
 		if n, err := strconv.ParseInt(name, base10, b64); err == nil {
 			return protoreflect.ValueOfInt64(int64(n)).MapKey(), nil
 		}
 
 	case protoreflect.Uint32Kind, protoreflect.Fixed32Kind:
 		if n, err := strconv.ParseUint(name, base10, b32); err == nil {
 			return protoreflect.ValueOfUint32(uint32(n)).MapKey(), nil
 		}
 
 	case protoreflect.Uint64Kind, protoreflect.Fixed64Kind:
 		if n, err := strconv.ParseUint(name, base10, b64); err == nil {
 			return protoreflect.ValueOfUint64(uint64(n)).MapKey(), nil
 		}
 
 	default:
 		panic(fmt.Sprintf("invalid kind for map key: %v", kind))
 	}
 
 	return protoreflect.MapKey{}, d.newError(tok.Pos(), "invalid value for %v key: %s", kind, tok.RawString())
 }