distribution/vendor/google.golang.org/protobuf/encoding/prototext/decode.go

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// 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"
"unicode/utf8"
"google.golang.org/protobuf/internal/encoding/messageset"
"google.golang.org/protobuf/internal/encoding/text"
"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/internal/strs"
"google.golang.org/protobuf/proto"
pref "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 textproto format unmarshaler.
type UnmarshalOptions struct {
pragma.NoUnkeyedLiterals
// AllowPartial accepts input for messages that will result in missing
// required fields. If AllowPartial is false (the default), Unmarshal will
// return error if there are any missing required fields.
AllowPartial bool
// DiscardUnknown specifies whether to ignore unknown fields when parsing.
// An unknown field is any field whose field name or field number does not
// resolve to any known or extension field in the message.
// By default, unmarshal rejects unknown fields as an error.
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.
// 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{text.NewDecoder(b), o}
if err := dec.unmarshalMessage(m.ProtoReflect(), false); err != nil {
return err
}
if o.AllowPartial {
return nil
}
return proto.CheckInitialized(m)
}
type decoder struct {
*text.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 text.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 into the given protoreflect.Message.
func (d decoder) unmarshalMessage(m pref.Message, checkDelims bool) error {
messageDesc := m.Descriptor()
if !flags.ProtoLegacy && messageset.IsMessageSet(messageDesc) {
return errors.New("no support for proto1 MessageSets")
}
if messageDesc.FullName() == genid.Any_message_fullname {
return d.unmarshalAny(m, checkDelims)
}
if checkDelims {
tok, err := d.Read()
if err != nil {
return err
}
if tok.Kind() != text.MessageOpen {
return d.unexpectedTokenError(tok)
}
}
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 typ := tok.Kind(); typ {
case text.Name:
// Continue below.
case text.EOF:
if checkDelims {
return text.ErrUnexpectedEOF
}
return nil
default:
if checkDelims && typ == text.MessageClose {
return nil
}
return d.unexpectedTokenError(tok)
}
// Resolve the field descriptor.
var name pref.Name
var fd pref.FieldDescriptor
var xt pref.ExtensionType
var xtErr error
var isFieldNumberName bool
switch tok.NameKind() {
case text.IdentName:
name = pref.Name(tok.IdentName())
fd = fieldDescs.ByTextName(string(name))
case text.TypeName:
// Handle extensions only. This code path is not for Any.
xt, xtErr = d.opts.Resolver.FindExtensionByName(pref.FullName(tok.TypeName()))
case text.FieldNumber:
isFieldNumberName = true
num := pref.FieldNumber(tok.FieldNumber())
if !num.IsValid() {
return d.newError(tok.Pos(), "invalid field number: %d", num)
}
fd = fieldDescs.ByNumber(num)
if fd == nil {
xt, xtErr = d.opts.Resolver.FindExtensionByNumber(messageDesc.FullName(), num)
}
}
if xt != nil {
fd = xt.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 if xtErr != nil && xtErr != protoregistry.NotFound {
return d.newError(tok.Pos(), "unable to resolve [%s]: %v", tok.RawString(), xtErr)
}
if flags.ProtoLegacy {
if fd != nil && fd.IsWeak() && fd.Message().IsPlaceholder() {
fd = nil // reset since the weak reference is not linked in
}
}
// Handle unknown fields.
if fd == nil {
if d.opts.DiscardUnknown || messageDesc.ReservedNames().Has(name) {
d.skipValue()
continue
}
return d.newError(tok.Pos(), "unknown field: %v", tok.RawString())
}
// Handle fields identified by field number.
if isFieldNumberName {
// TODO: Add an option to permit parsing field numbers.
//
// This requires careful thought as the MarshalOptions.EmitUnknown
// option allows formatting unknown fields as the field number and the
// best-effort textual representation of the field value. In that case,
// it may not be possible to unmarshal the value from a parser that does
// have information about the unknown field.
return d.newError(tok.Pos(), "cannot specify field by number: %v", tok.RawString())
}
switch {
case fd.IsList():
kind := fd.Kind()
if kind != pref.MessageKind && kind != pref.GroupKind && !tok.HasSeparator() {
return d.syntaxError(tok.Pos(), "missing field separator :")
}
list := m.Mutable(fd).List()
if err := d.unmarshalList(fd, list); err != nil {
return err
}
case fd.IsMap():
mmap := m.Mutable(fd).Map()
if err := d.unmarshalMap(fd, mmap); err != nil {
return err
}
default:
kind := fd.Kind()
if kind != pref.MessageKind && kind != pref.GroupKind && !tok.HasSeparator() {
return d.syntaxError(tok.Pos(), "missing field separator :")
}
// 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 %q, oneof %v is already set", tok.RawString(), od.FullName())
}
seenOneofs.Set(idx)
}
num := uint64(fd.Number())
if seenNums.Has(num) {
return d.newError(tok.Pos(), "non-repeated field %q is repeated", tok.RawString())
}
if err := d.unmarshalSingular(fd, m); err != nil {
return err
}
seenNums.Set(num)
}
}
return nil
}
// unmarshalSingular unmarshals a non-repeated field value specified by the
// given FieldDescriptor.
func (d decoder) unmarshalSingular(fd pref.FieldDescriptor, m pref.Message) error {
var val pref.Value
var err error
switch fd.Kind() {
case pref.MessageKind, pref.GroupKind:
val = m.NewField(fd)
err = d.unmarshalMessage(val.Message(), true)
default:
val, err = d.unmarshalScalar(fd)
}
if err == nil {
m.Set(fd, val)
}
return err
}
// unmarshalScalar unmarshals a scalar/enum protoreflect.Value specified by the
// given FieldDescriptor.
func (d decoder) unmarshalScalar(fd pref.FieldDescriptor) (pref.Value, error) {
tok, err := d.Read()
if err != nil {
return pref.Value{}, err
}
if tok.Kind() != text.Scalar {
return pref.Value{}, d.unexpectedTokenError(tok)
}
kind := fd.Kind()
switch kind {
case pref.BoolKind:
if b, ok := tok.Bool(); ok {
return pref.ValueOfBool(b), nil
}
case pref.Int32Kind, pref.Sint32Kind, pref.Sfixed32Kind:
if n, ok := tok.Int32(); ok {
return pref.ValueOfInt32(n), nil
}
case pref.Int64Kind, pref.Sint64Kind, pref.Sfixed64Kind:
if n, ok := tok.Int64(); ok {
return pref.ValueOfInt64(n), nil
}
case pref.Uint32Kind, pref.Fixed32Kind:
if n, ok := tok.Uint32(); ok {
return pref.ValueOfUint32(n), nil
}
case pref.Uint64Kind, pref.Fixed64Kind:
if n, ok := tok.Uint64(); ok {
return pref.ValueOfUint64(n), nil
}
case pref.FloatKind:
if n, ok := tok.Float32(); ok {
return pref.ValueOfFloat32(n), nil
}
case pref.DoubleKind:
if n, ok := tok.Float64(); ok {
return pref.ValueOfFloat64(n), nil
}
case pref.StringKind:
if s, ok := tok.String(); ok {
if strs.EnforceUTF8(fd) && !utf8.ValidString(s) {
return pref.Value{}, d.newError(tok.Pos(), "contains invalid UTF-8")
}
return pref.ValueOfString(s), nil
}
case pref.BytesKind:
if b, ok := tok.String(); ok {
return pref.ValueOfBytes([]byte(b)), nil
}
case pref.EnumKind:
if lit, ok := tok.Enum(); ok {
// Lookup EnumNumber based on name.
if enumVal := fd.Enum().Values().ByName(pref.Name(lit)); enumVal != nil {
return pref.ValueOfEnum(enumVal.Number()), nil
}
}
if num, ok := tok.Int32(); ok {
return pref.ValueOfEnum(pref.EnumNumber(num)), nil
}
default:
panic(fmt.Sprintf("invalid scalar kind %v", kind))
}
return pref.Value{}, d.newError(tok.Pos(), "invalid value for %v type: %v", kind, tok.RawString())
}
// unmarshalList unmarshals into given protoreflect.List. A list value can
// either be in [] syntax or simply just a single scalar/message value.
func (d decoder) unmarshalList(fd pref.FieldDescriptor, list pref.List) error {
tok, err := d.Peek()
if err != nil {
return err
}
switch fd.Kind() {
case pref.MessageKind, pref.GroupKind:
switch tok.Kind() {
case text.ListOpen:
d.Read()
for {
tok, err := d.Peek()
if err != nil {
return err
}
switch tok.Kind() {
case text.ListClose:
d.Read()
return nil
case text.MessageOpen:
pval := list.NewElement()
if err := d.unmarshalMessage(pval.Message(), true); err != nil {
return err
}
list.Append(pval)
default:
return d.unexpectedTokenError(tok)
}
}
case text.MessageOpen:
pval := list.NewElement()
if err := d.unmarshalMessage(pval.Message(), true); err != nil {
return err
}
list.Append(pval)
return nil
}
default:
switch tok.Kind() {
case text.ListOpen:
d.Read()
for {
tok, err := d.Peek()
if err != nil {
return err
}
switch tok.Kind() {
case text.ListClose:
d.Read()
return nil
case text.Scalar:
pval, err := d.unmarshalScalar(fd)
if err != nil {
return err
}
list.Append(pval)
default:
return d.unexpectedTokenError(tok)
}
}
case text.Scalar:
pval, err := d.unmarshalScalar(fd)
if err != nil {
return err
}
list.Append(pval)
return nil
}
}
return d.unexpectedTokenError(tok)
}
// unmarshalMap unmarshals into given protoreflect.Map. A map value is a
// textproto message containing {key: <kvalue>, value: <mvalue>}.
func (d decoder) unmarshalMap(fd pref.FieldDescriptor, mmap pref.Map) error {
// Determine ahead whether map entry is a scalar type or a message type in
// order to call the appropriate unmarshalMapValue func inside
// unmarshalMapEntry.
var unmarshalMapValue func() (pref.Value, error)
switch fd.MapValue().Kind() {
case pref.MessageKind, pref.GroupKind:
unmarshalMapValue = func() (pref.Value, error) {
pval := mmap.NewValue()
if err := d.unmarshalMessage(pval.Message(), true); err != nil {
return pref.Value{}, err
}
return pval, nil
}
default:
unmarshalMapValue = func() (pref.Value, error) {
return d.unmarshalScalar(fd.MapValue())
}
}
tok, err := d.Read()
if err != nil {
return err
}
switch tok.Kind() {
case text.MessageOpen:
return d.unmarshalMapEntry(fd, mmap, unmarshalMapValue)
case text.ListOpen:
for {
tok, err := d.Read()
if err != nil {
return err
}
switch tok.Kind() {
case text.ListClose:
return nil
case text.MessageOpen:
if err := d.unmarshalMapEntry(fd, mmap, unmarshalMapValue); err != nil {
return err
}
default:
return d.unexpectedTokenError(tok)
}
}
default:
return d.unexpectedTokenError(tok)
}
}
// unmarshalMap unmarshals into given protoreflect.Map. A map value is a
// textproto message containing {key: <kvalue>, value: <mvalue>}.
func (d decoder) unmarshalMapEntry(fd pref.FieldDescriptor, mmap pref.Map, unmarshalMapValue func() (pref.Value, error)) error {
var key pref.MapKey
var pval pref.Value
Loop:
for {
// Read field name.
tok, err := d.Read()
if err != nil {
return err
}
switch tok.Kind() {
case text.Name:
if tok.NameKind() != text.IdentName {
if !d.opts.DiscardUnknown {
return d.newError(tok.Pos(), "unknown map entry field %q", tok.RawString())
}
d.skipValue()
continue Loop
}
// Continue below.
case text.MessageClose:
break Loop
default:
return d.unexpectedTokenError(tok)
}
switch name := pref.Name(tok.IdentName()); name {
case genid.MapEntry_Key_field_name:
if !tok.HasSeparator() {
return d.syntaxError(tok.Pos(), "missing field separator :")
}
if key.IsValid() {
return d.newError(tok.Pos(), "map entry %q cannot be repeated", name)
}
val, err := d.unmarshalScalar(fd.MapKey())
if err != nil {
return err
}
key = val.MapKey()
case genid.MapEntry_Value_field_name:
if kind := fd.MapValue().Kind(); (kind != pref.MessageKind) && (kind != pref.GroupKind) {
if !tok.HasSeparator() {
return d.syntaxError(tok.Pos(), "missing field separator :")
}
}
if pval.IsValid() {
return d.newError(tok.Pos(), "map entry %q cannot be repeated", name)
}
pval, err = unmarshalMapValue()
if err != nil {
return err
}
default:
if !d.opts.DiscardUnknown {
return d.newError(tok.Pos(), "unknown map entry field %q", name)
}
d.skipValue()
}
}
if !key.IsValid() {
key = fd.MapKey().Default().MapKey()
}
if !pval.IsValid() {
switch fd.MapValue().Kind() {
case pref.MessageKind, pref.GroupKind:
// If value field is not set for message/group types, construct an
// empty one as default.
pval = mmap.NewValue()
default:
pval = fd.MapValue().Default()
}
}
mmap.Set(key, pval)
return nil
}
// unmarshalAny unmarshals an Any textproto. It can either be in expanded form
// or non-expanded form.
func (d decoder) unmarshalAny(m pref.Message, checkDelims bool) error {
var typeURL string
var bValue []byte
var seenTypeUrl bool
var seenValue bool
var isExpanded bool
if checkDelims {
tok, err := d.Read()
if err != nil {
return err
}
if tok.Kind() != text.MessageOpen {
return d.unexpectedTokenError(tok)
}
}
Loop:
for {
// Read field name. Can only have 3 possible field names, i.e. type_url,
// value and type URL name inside [].
tok, err := d.Read()
if err != nil {
return err
}
if typ := tok.Kind(); typ != text.Name {
if checkDelims {
if typ == text.MessageClose {
break Loop
}
} else if typ == text.EOF {
break Loop
}
return d.unexpectedTokenError(tok)
}
switch tok.NameKind() {
case text.IdentName:
// Both type_url and value fields require field separator :.
if !tok.HasSeparator() {
return d.syntaxError(tok.Pos(), "missing field separator :")
}
switch name := pref.Name(tok.IdentName()); name {
case genid.Any_TypeUrl_field_name:
if seenTypeUrl {
return d.newError(tok.Pos(), "duplicate %v field", genid.Any_TypeUrl_field_fullname)
}
if isExpanded {
return d.newError(tok.Pos(), "conflict with [%s] field", typeURL)
}
tok, err := d.Read()
if err != nil {
return err
}
var ok bool
typeURL, ok = tok.String()
if !ok {
return d.newError(tok.Pos(), "invalid %v field value: %v", genid.Any_TypeUrl_field_fullname, tok.RawString())
}
seenTypeUrl = true
case genid.Any_Value_field_name:
if seenValue {
return d.newError(tok.Pos(), "duplicate %v field", genid.Any_Value_field_fullname)
}
if isExpanded {
return d.newError(tok.Pos(), "conflict with [%s] field", typeURL)
}
tok, err := d.Read()
if err != nil {
return err
}
s, ok := tok.String()
if !ok {
return d.newError(tok.Pos(), "invalid %v field value: %v", genid.Any_Value_field_fullname, tok.RawString())
}
bValue = []byte(s)
seenValue = true
default:
if !d.opts.DiscardUnknown {
return d.newError(tok.Pos(), "invalid field name %q in %v message", tok.RawString(), genid.Any_message_fullname)
}
}
case text.TypeName:
if isExpanded {
return d.newError(tok.Pos(), "cannot have more than one type")
}
if seenTypeUrl {
return d.newError(tok.Pos(), "conflict with type_url field")
}
typeURL = tok.TypeName()
var err error
bValue, err = d.unmarshalExpandedAny(typeURL, tok.Pos())
if err != nil {
return err
}
isExpanded = true
default:
if !d.opts.DiscardUnknown {
return d.newError(tok.Pos(), "invalid field name %q in %v message", tok.RawString(), genid.Any_message_fullname)
}
}
}
fds := m.Descriptor().Fields()
if len(typeURL) > 0 {
m.Set(fds.ByNumber(genid.Any_TypeUrl_field_number), pref.ValueOfString(typeURL))
}
if len(bValue) > 0 {
m.Set(fds.ByNumber(genid.Any_Value_field_number), pref.ValueOfBytes(bValue))
}
return nil
}
func (d decoder) unmarshalExpandedAny(typeURL string, pos int) ([]byte, error) {
mt, err := d.opts.Resolver.FindMessageByURL(typeURL)
if err != nil {
return nil, d.newError(pos, "unable to resolve message [%v]: %v", typeURL, err)
}
// Create new message for the embedded message type and unmarshal the value
// field into it.
m := mt.New()
if err := d.unmarshalMessage(m, true); err != nil {
return nil, err
}
// Serialize the embedded message and return the resulting bytes.
b, err := proto.MarshalOptions{
AllowPartial: true, // Never check required fields inside an Any.
Deterministic: true,
}.Marshal(m.Interface())
if err != nil {
return nil, d.newError(pos, "error in marshaling message into Any.value: %v", err)
}
return b, nil
}
// skipValue makes the decoder parse a field value in order to advance the read
// to the next field. It relies on Read returning an error if the types are not
// in valid sequence.
func (d decoder) skipValue() error {
tok, err := d.Read()
if err != nil {
return err
}
// Only need to continue reading for messages and lists.
switch tok.Kind() {
case text.MessageOpen:
return d.skipMessageValue()
case text.ListOpen:
for {
tok, err := d.Read()
if err != nil {
return err
}
switch tok.Kind() {
case text.ListClose:
return nil
case text.MessageOpen:
return d.skipMessageValue()
default:
// Skip items. This will not validate whether skipped values are
// of the same type or not, same behavior as C++
// TextFormat::Parser::AllowUnknownField(true) version 3.8.0.
if err := d.skipValue(); err != nil {
return err
}
}
}
}
return nil
}
// skipMessageValue makes the decoder parse and skip over all fields in a
// message. It assumes that the previous read type is MessageOpen.
func (d decoder) skipMessageValue() error {
for {
tok, err := d.Read()
if err != nil {
return err
}
switch tok.Kind() {
case text.MessageClose:
return nil
case text.Name:
if err := d.skipValue(); err != nil {
return err
}
}
}
}