blob: 71c755c15595f27aed6bc60c8d06d219975e59f1 [file] [log] [blame]
// 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/pragma"
"google.golang.org/protobuf/internal/set"
"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.
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 UnmarshalOptions object. It will clear the message first before
// setting the fields. If it returns an error, the given message may be
// partially set.
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 pref.Message, skipTypeURL bool) error {
if isCustomType(m.Descriptor().FullName()) {
return d.unmarshalCustomType(m)
}
tok, err := d.Read()
if err != nil {
return err
}
if tok.Kind() != json.ObjectOpen {
return d.unexpectedTokenError(tok)
}
if err := d.unmarshalFields(m, skipTypeURL); err != nil {
return err
}
return nil
}
// unmarshalFields unmarshals the fields into the given protoreflect.Message.
func (d decoder) unmarshalFields(m pref.Message, skipTypeURL bool) error {
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 pref.FieldDescriptor
if strings.HasPrefix(name, "[") && strings.HasSuffix(name, "]") {
// Only extension names are in [name] format.
extName := pref.FullName(name[1 : len(name)-1])
extType, err := d.findExtension(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.ByName(pref.Name(name))
if fd == nil {
// The proto name of a group field is in all lowercase,
// while the textual field name is the group message name.
gd := fieldDescs.ByName(pref.Name(strings.ToLower(name)))
if gd != nil && gd.Kind() == pref.GroupKind && gd.Message().Name() == pref.Name(name) {
fd = gd
}
} else if fd.Kind() == pref.GroupKind && fd.Message().Name() != pref.Name(name) {
fd = nil // reset since field name is actually the message 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
}
}
}
}
// findExtension returns protoreflect.ExtensionType from the resolver if found.
func (d decoder) findExtension(xtName pref.FullName) (pref.ExtensionType, error) {
xt, err := d.opts.Resolver.FindExtensionByName(xtName)
if err == nil {
return xt, nil
}
return messageset.FindMessageSetExtension(d.opts.Resolver, xtName)
}
func isKnownValue(fd pref.FieldDescriptor) bool {
md := fd.Message()
return md != nil && md.FullName() == "google.protobuf.Value"
}
func isNullValue(fd pref.FieldDescriptor) bool {
ed := fd.Enum()
return ed != nil && ed.FullName() == "google.protobuf.NullValue"
}
// unmarshalSingular unmarshals to the non-repeated field specified
// by the given FieldDescriptor.
func (d decoder) unmarshalSingular(m pref.Message, fd pref.FieldDescriptor) 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(), 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 pref.FieldDescriptor) (pref.Value, error) {
const b32 int = 32
const b64 int = 64
tok, err := d.Read()
if err != nil {
return pref.Value{}, err
}
kind := fd.Kind()
switch kind {
case pref.BoolKind:
if tok.Kind() == json.Bool {
return pref.ValueOfBool(tok.Bool()), nil
}
case pref.Int32Kind, pref.Sint32Kind, pref.Sfixed32Kind:
if v, ok := unmarshalInt(tok, b32); ok {
return v, nil
}
case pref.Int64Kind, pref.Sint64Kind, pref.Sfixed64Kind:
if v, ok := unmarshalInt(tok, b64); ok {
return v, nil
}
case pref.Uint32Kind, pref.Fixed32Kind:
if v, ok := unmarshalUint(tok, b32); ok {
return v, nil
}
case pref.Uint64Kind, pref.Fixed64Kind:
if v, ok := unmarshalUint(tok, b64); ok {
return v, nil
}
case pref.FloatKind:
if v, ok := unmarshalFloat(tok, b32); ok {
return v, nil
}
case pref.DoubleKind:
if v, ok := unmarshalFloat(tok, b64); ok {
return v, nil
}
case pref.StringKind:
if tok.Kind() == json.String {
return pref.ValueOfString(tok.ParsedString()), nil
}
case pref.BytesKind:
if v, ok := unmarshalBytes(tok); ok {
return v, nil
}
case pref.EnumKind:
if v, ok := unmarshalEnum(tok, fd); ok {
return v, nil
}
default:
panic(fmt.Sprintf("unmarshalScalar: invalid scalar kind %v", kind))
}
return pref.Value{}, d.newError(tok.Pos(), "invalid value for %v type: %v", kind, tok.RawString())
}
func unmarshalInt(tok json.Token, bitSize int) (pref.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 pref.Value{}, false
}
dec := json.NewDecoder([]byte(s))
tok, err := dec.Read()
if err != nil {
return pref.Value{}, false
}
return getInt(tok, bitSize)
}
return pref.Value{}, false
}
func getInt(tok json.Token, bitSize int) (pref.Value, bool) {
n, ok := tok.Int(bitSize)
if !ok {
return pref.Value{}, false
}
if bitSize == 32 {
return pref.ValueOfInt32(int32(n)), true
}
return pref.ValueOfInt64(n), true
}
func unmarshalUint(tok json.Token, bitSize int) (pref.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 pref.Value{}, false
}
dec := json.NewDecoder([]byte(s))
tok, err := dec.Read()
if err != nil {
return pref.Value{}, false
}
return getUint(tok, bitSize)
}
return pref.Value{}, false
}
func getUint(tok json.Token, bitSize int) (pref.Value, bool) {
n, ok := tok.Uint(bitSize)
if !ok {
return pref.Value{}, false
}
if bitSize == 32 {
return pref.ValueOfUint32(uint32(n)), true
}
return pref.ValueOfUint64(n), true
}
func unmarshalFloat(tok json.Token, bitSize int) (pref.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 pref.ValueOfFloat32(float32(math.NaN())), true
}
return pref.ValueOfFloat64(math.NaN()), true
case "Infinity":
if bitSize == 32 {
return pref.ValueOfFloat32(float32(math.Inf(+1))), true
}
return pref.ValueOfFloat64(math.Inf(+1)), true
case "-Infinity":
if bitSize == 32 {
return pref.ValueOfFloat32(float32(math.Inf(-1))), true
}
return pref.ValueOfFloat64(math.Inf(-1)), true
}
// Decode number from string.
if len(s) != len(strings.TrimSpace(s)) {
return pref.Value{}, false
}
dec := json.NewDecoder([]byte(s))
tok, err := dec.Read()
if err != nil {
return pref.Value{}, false
}
return getFloat(tok, bitSize)
}
return pref.Value{}, false
}
func getFloat(tok json.Token, bitSize int) (pref.Value, bool) {
n, ok := tok.Float(bitSize)
if !ok {
return pref.Value{}, false
}
if bitSize == 32 {
return pref.ValueOfFloat32(float32(n)), true
}
return pref.ValueOfFloat64(n), true
}
func unmarshalBytes(tok json.Token) (pref.Value, bool) {
if tok.Kind() != json.String {
return pref.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 pref.Value{}, false
}
return pref.ValueOfBytes(b), true
}
func unmarshalEnum(tok json.Token, fd pref.FieldDescriptor) (pref.Value, bool) {
switch tok.Kind() {
case json.String:
// Lookup EnumNumber based on name.
s := tok.ParsedString()
if enumVal := fd.Enum().Values().ByName(pref.Name(s)); enumVal != nil {
return pref.ValueOfEnum(enumVal.Number()), true
}
case json.Number:
if n, ok := tok.Int(32); ok {
return pref.ValueOfEnum(pref.EnumNumber(n)), true
}
case json.Null:
// This is only valid for google.protobuf.NullValue.
if isNullValue(fd) {
return pref.ValueOfEnum(0), true
}
}
return pref.Value{}, false
}
func (d decoder) unmarshalList(list pref.List, fd pref.FieldDescriptor) error {
tok, err := d.Read()
if err != nil {
return err
}
if tok.Kind() != json.ArrayOpen {
return d.unexpectedTokenError(tok)
}
switch fd.Kind() {
case pref.MessageKind, pref.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 pref.Map, fd pref.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() (pref.Value, error)
switch fd.MapValue().Kind() {
case pref.MessageKind, pref.GroupKind:
unmarshalMapValue = func() (pref.Value, error) {
val := mmap.NewValue()
if err := d.unmarshalMessage(val.Message(), false); err != nil {
return pref.Value{}, err
}
return val, nil
}
default:
unmarshalMapValue = func() (pref.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 pref.FieldDescriptor) (pref.MapKey, error) {
const b32 = 32
const b64 = 64
const base10 = 10
name := tok.Name()
kind := fd.Kind()
switch kind {
case pref.StringKind:
return pref.ValueOfString(name).MapKey(), nil
case pref.BoolKind:
switch name {
case "true":
return pref.ValueOfBool(true).MapKey(), nil
case "false":
return pref.ValueOfBool(false).MapKey(), nil
}
case pref.Int32Kind, pref.Sint32Kind, pref.Sfixed32Kind:
if n, err := strconv.ParseInt(name, base10, b32); err == nil {
return pref.ValueOfInt32(int32(n)).MapKey(), nil
}
case pref.Int64Kind, pref.Sint64Kind, pref.Sfixed64Kind:
if n, err := strconv.ParseInt(name, base10, b64); err == nil {
return pref.ValueOfInt64(int64(n)).MapKey(), nil
}
case pref.Uint32Kind, pref.Fixed32Kind:
if n, err := strconv.ParseUint(name, base10, b32); err == nil {
return pref.ValueOfUint32(uint32(n)).MapKey(), nil
}
case pref.Uint64Kind, pref.Fixed64Kind:
if n, err := strconv.ParseUint(name, base10, b64); err == nil {
return pref.ValueOfUint64(uint64(n)).MapKey(), nil
}
default:
panic(fmt.Sprintf("invalid kind for map key: %v", kind))
}
return pref.MapKey{}, d.newError(tok.Pos(), "invalid value for %v key: %s", kind, tok.RawString())
}