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// Copyright 2015 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 jsonpb
import (
"encoding/json"
"errors"
"fmt"
"io"
"math"
"reflect"
"strconv"
"strings"
"time"
"github.com/golang/protobuf/proto"
"google.golang.org/protobuf/encoding/protojson"
protoV2 "google.golang.org/protobuf/proto"
"google.golang.org/protobuf/reflect/protoreflect"
"google.golang.org/protobuf/reflect/protoregistry"
)
const wrapJSONUnmarshalV2 = false
// UnmarshalNext unmarshals the next JSON object from d into m.
func UnmarshalNext(d *json.Decoder, m proto.Message) error {
return new(Unmarshaler).UnmarshalNext(d, m)
}
// Unmarshal unmarshals a JSON object from r into m.
func Unmarshal(r io.Reader, m proto.Message) error {
return new(Unmarshaler).Unmarshal(r, m)
}
// UnmarshalString unmarshals a JSON object from s into m.
func UnmarshalString(s string, m proto.Message) error {
return new(Unmarshaler).Unmarshal(strings.NewReader(s), m)
}
// Unmarshaler is a configurable object for converting from a JSON
// representation to a protocol buffer object.
type Unmarshaler struct {
// AllowUnknownFields specifies whether to allow messages to contain
// unknown JSON fields, as opposed to failing to unmarshal.
AllowUnknownFields bool
// AnyResolver is used to resolve the google.protobuf.Any well-known type.
// If unset, the global registry is used by default.
AnyResolver AnyResolver
}
// JSONPBUnmarshaler is implemented by protobuf messages that customize the way
// they are unmarshaled from JSON. Messages that implement this should also
// implement JSONPBMarshaler so that the custom format can be produced.
//
// The JSON unmarshaling must follow the JSON to proto specification:
// https://developers.google.com/protocol-buffers/docs/proto3#json
//
// Deprecated: Custom types should implement protobuf reflection instead.
type JSONPBUnmarshaler interface {
UnmarshalJSONPB(*Unmarshaler, []byte) error
}
// Unmarshal unmarshals a JSON object from r into m.
func (u *Unmarshaler) Unmarshal(r io.Reader, m proto.Message) error {
return u.UnmarshalNext(json.NewDecoder(r), m)
}
// UnmarshalNext unmarshals the next JSON object from d into m.
func (u *Unmarshaler) UnmarshalNext(d *json.Decoder, m proto.Message) error {
if m == nil {
return errors.New("invalid nil message")
}
// Parse the next JSON object from the stream.
raw := json.RawMessage{}
if err := d.Decode(&raw); err != nil {
return err
}
// Check for custom unmarshalers first since they may not properly
// implement protobuf reflection that the logic below relies on.
if jsu, ok := m.(JSONPBUnmarshaler); ok {
return jsu.UnmarshalJSONPB(u, raw)
}
mr := proto.MessageReflect(m)
// NOTE: For historical reasons, a top-level null is treated as a noop.
// This is incorrect, but kept for compatibility.
if string(raw) == "null" && mr.Descriptor().FullName() != "google.protobuf.Value" {
return nil
}
if wrapJSONUnmarshalV2 {
// NOTE: If input message is non-empty, we need to preserve merge semantics
// of the old jsonpb implementation. These semantics are not supported by
// the protobuf JSON specification.
isEmpty := true
mr.Range(func(protoreflect.FieldDescriptor, protoreflect.Value) bool {
isEmpty = false // at least one iteration implies non-empty
return false
})
if !isEmpty {
// Perform unmarshaling into a newly allocated, empty message.
mr = mr.New()
// Use a defer to copy all unmarshaled fields into the original message.
dst := proto.MessageReflect(m)
defer mr.Range(func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool {
dst.Set(fd, v)
return true
})
}
// Unmarshal using the v2 JSON unmarshaler.
opts := protojson.UnmarshalOptions{
DiscardUnknown: u.AllowUnknownFields,
}
if u.AnyResolver != nil {
opts.Resolver = anyResolver{u.AnyResolver}
}
return opts.Unmarshal(raw, mr.Interface())
} else {
if err := u.unmarshalMessage(mr, raw); err != nil {
return err
}
return protoV2.CheckInitialized(mr.Interface())
}
}
func (u *Unmarshaler) unmarshalMessage(m protoreflect.Message, in []byte) error {
md := m.Descriptor()
fds := md.Fields()
if string(in) == "null" && md.FullName() != "google.protobuf.Value" {
return nil
}
if jsu, ok := proto.MessageV1(m.Interface()).(JSONPBUnmarshaler); ok {
return jsu.UnmarshalJSONPB(u, in)
}
switch wellKnownType(md.FullName()) {
case "Any":
var jsonObject map[string]json.RawMessage
if err := json.Unmarshal(in, &jsonObject); err != nil {
return err
}
rawTypeURL, ok := jsonObject["@type"]
if !ok {
return errors.New("Any JSON doesn't have '@type'")
}
typeURL, err := unquoteString(string(rawTypeURL))
if err != nil {
return fmt.Errorf("can't unmarshal Any's '@type': %q", rawTypeURL)
}
m.Set(fds.ByNumber(1), protoreflect.ValueOfString(typeURL))
var m2 protoreflect.Message
if u.AnyResolver != nil {
mi, err := u.AnyResolver.Resolve(typeURL)
if err != nil {
return err
}
m2 = proto.MessageReflect(mi)
} else {
mt, err := protoregistry.GlobalTypes.FindMessageByURL(typeURL)
if err != nil {
if err == protoregistry.NotFound {
return fmt.Errorf("could not resolve Any message type: %v", typeURL)
}
return err
}
m2 = mt.New()
}
if wellKnownType(m2.Descriptor().FullName()) != "" {
rawValue, ok := jsonObject["value"]
if !ok {
return errors.New("Any JSON doesn't have 'value'")
}
if err := u.unmarshalMessage(m2, rawValue); err != nil {
return fmt.Errorf("can't unmarshal Any nested proto %v: %v", typeURL, err)
}
} else {
delete(jsonObject, "@type")
rawJSON, err := json.Marshal(jsonObject)
if err != nil {
return fmt.Errorf("can't generate JSON for Any's nested proto to be unmarshaled: %v", err)
}
if err = u.unmarshalMessage(m2, rawJSON); err != nil {
return fmt.Errorf("can't unmarshal Any nested proto %v: %v", typeURL, err)
}
}
rawWire, err := protoV2.Marshal(m2.Interface())
if err != nil {
return fmt.Errorf("can't marshal proto %v into Any.Value: %v", typeURL, err)
}
m.Set(fds.ByNumber(2), protoreflect.ValueOfBytes(rawWire))
return nil
case "BoolValue", "BytesValue", "StringValue",
"Int32Value", "UInt32Value", "FloatValue",
"Int64Value", "UInt64Value", "DoubleValue":
fd := fds.ByNumber(1)
v, err := u.unmarshalValue(m.NewField(fd), in, fd)
if err != nil {
return err
}
m.Set(fd, v)
return nil
case "Duration":
v, err := unquoteString(string(in))
if err != nil {
return err
}
d, err := time.ParseDuration(v)
if err != nil {
return fmt.Errorf("bad Duration: %v", err)
}
sec := d.Nanoseconds() / 1e9
nsec := d.Nanoseconds() % 1e9
m.Set(fds.ByNumber(1), protoreflect.ValueOfInt64(int64(sec)))
m.Set(fds.ByNumber(2), protoreflect.ValueOfInt32(int32(nsec)))
return nil
case "Timestamp":
v, err := unquoteString(string(in))
if err != nil {
return err
}
t, err := time.Parse(time.RFC3339Nano, v)
if err != nil {
return fmt.Errorf("bad Timestamp: %v", err)
}
sec := t.Unix()
nsec := t.Nanosecond()
m.Set(fds.ByNumber(1), protoreflect.ValueOfInt64(int64(sec)))
m.Set(fds.ByNumber(2), protoreflect.ValueOfInt32(int32(nsec)))
return nil
case "Value":
switch {
case string(in) == "null":
m.Set(fds.ByNumber(1), protoreflect.ValueOfEnum(0))
case string(in) == "true":
m.Set(fds.ByNumber(4), protoreflect.ValueOfBool(true))
case string(in) == "false":
m.Set(fds.ByNumber(4), protoreflect.ValueOfBool(false))
case hasPrefixAndSuffix('"', in, '"'):
s, err := unquoteString(string(in))
if err != nil {
return fmt.Errorf("unrecognized type for Value %q", in)
}
m.Set(fds.ByNumber(3), protoreflect.ValueOfString(s))
case hasPrefixAndSuffix('[', in, ']'):
v := m.Mutable(fds.ByNumber(6))
return u.unmarshalMessage(v.Message(), in)
case hasPrefixAndSuffix('{', in, '}'):
v := m.Mutable(fds.ByNumber(5))
return u.unmarshalMessage(v.Message(), in)
default:
f, err := strconv.ParseFloat(string(in), 0)
if err != nil {
return fmt.Errorf("unrecognized type for Value %q", in)
}
m.Set(fds.ByNumber(2), protoreflect.ValueOfFloat64(f))
}
return nil
case "ListValue":
var jsonArray []json.RawMessage
if err := json.Unmarshal(in, &jsonArray); err != nil {
return fmt.Errorf("bad ListValue: %v", err)
}
lv := m.Mutable(fds.ByNumber(1)).List()
for _, raw := range jsonArray {
ve := lv.NewElement()
if err := u.unmarshalMessage(ve.Message(), raw); err != nil {
return err
}
lv.Append(ve)
}
return nil
case "Struct":
var jsonObject map[string]json.RawMessage
if err := json.Unmarshal(in, &jsonObject); err != nil {
return fmt.Errorf("bad StructValue: %v", err)
}
mv := m.Mutable(fds.ByNumber(1)).Map()
for key, raw := range jsonObject {
kv := protoreflect.ValueOf(key).MapKey()
vv := mv.NewValue()
if err := u.unmarshalMessage(vv.Message(), raw); err != nil {
return fmt.Errorf("bad value in StructValue for key %q: %v", key, err)
}
mv.Set(kv, vv)
}
return nil
}
var jsonObject map[string]json.RawMessage
if err := json.Unmarshal(in, &jsonObject); err != nil {
return err
}
// Handle known fields.
for i := 0; i < fds.Len(); i++ {
fd := fds.Get(i)
if fd.IsWeak() && fd.Message().IsPlaceholder() {
continue // weak reference is not linked in
}
// Search for any raw JSON value associated with this field.
var raw json.RawMessage
name := string(fd.Name())
if fd.Kind() == protoreflect.GroupKind {
name = string(fd.Message().Name())
}
if v, ok := jsonObject[name]; ok {
delete(jsonObject, name)
raw = v
}
name = string(fd.JSONName())
if v, ok := jsonObject[name]; ok {
delete(jsonObject, name)
raw = v
}
// Unmarshal the field value.
if raw == nil || (string(raw) == "null" && !isSingularWellKnownValue(fd)) {
continue
}
v, err := u.unmarshalValue(m.NewField(fd), raw, fd)
if err != nil {
return err
}
m.Set(fd, v)
}
// Handle extension fields.
for name, raw := range jsonObject {
if !strings.HasPrefix(name, "[") || !strings.HasSuffix(name, "]") {
continue
}
// Resolve the extension field by name.
xname := protoreflect.FullName(name[len("[") : len(name)-len("]")])
xt, _ := protoregistry.GlobalTypes.FindExtensionByName(xname)
if xt == nil && isMessageSet(md) {
xt, _ = protoregistry.GlobalTypes.FindExtensionByName(xname.Append("message_set_extension"))
}
if xt == nil {
continue
}
delete(jsonObject, name)
fd := xt.TypeDescriptor()
if fd.ContainingMessage().FullName() != m.Descriptor().FullName() {
return fmt.Errorf("extension field %q does not extend message %q", xname, m.Descriptor().FullName())
}
// Unmarshal the field value.
if raw == nil || (string(raw) == "null" && !isSingularWellKnownValue(fd)) {
continue
}
v, err := u.unmarshalValue(m.NewField(fd), raw, fd)
if err != nil {
return err
}
m.Set(fd, v)
}
if !u.AllowUnknownFields && len(jsonObject) > 0 {
for name := range jsonObject {
return fmt.Errorf("unknown field %q in %v", name, md.FullName())
}
}
return nil
}
func isSingularWellKnownValue(fd protoreflect.FieldDescriptor) bool {
if md := fd.Message(); md != nil {
return md.FullName() == "google.protobuf.Value" && fd.Cardinality() != protoreflect.Repeated
}
return false
}
func (u *Unmarshaler) unmarshalValue(v protoreflect.Value, in []byte, fd protoreflect.FieldDescriptor) (protoreflect.Value, error) {
switch {
case fd.IsList():
var jsonArray []json.RawMessage
if err := json.Unmarshal(in, &jsonArray); err != nil {
return v, err
}
lv := v.List()
for _, raw := range jsonArray {
ve, err := u.unmarshalSingularValue(lv.NewElement(), raw, fd)
if err != nil {
return v, err
}
lv.Append(ve)
}
return v, nil
case fd.IsMap():
var jsonObject map[string]json.RawMessage
if err := json.Unmarshal(in, &jsonObject); err != nil {
return v, err
}
kfd := fd.MapKey()
vfd := fd.MapValue()
mv := v.Map()
for key, raw := range jsonObject {
var kv protoreflect.MapKey
if kfd.Kind() == protoreflect.StringKind {
kv = protoreflect.ValueOf(key).MapKey()
} else {
v, err := u.unmarshalSingularValue(kfd.Default(), []byte(key), kfd)
if err != nil {
return v, err
}
kv = v.MapKey()
}
vv, err := u.unmarshalSingularValue(mv.NewValue(), raw, vfd)
if err != nil {
return v, err
}
mv.Set(kv, vv)
}
return v, nil
default:
return u.unmarshalSingularValue(v, in, fd)
}
}
var nonFinite = map[string]float64{
`"NaN"`: math.NaN(),
`"Infinity"`: math.Inf(+1),
`"-Infinity"`: math.Inf(-1),
}
func (u *Unmarshaler) unmarshalSingularValue(v protoreflect.Value, in []byte, fd protoreflect.FieldDescriptor) (protoreflect.Value, error) {
switch fd.Kind() {
case protoreflect.BoolKind:
return unmarshalValue(in, new(bool))
case protoreflect.Int32Kind, protoreflect.Sint32Kind, protoreflect.Sfixed32Kind:
return unmarshalValue(trimQuote(in), new(int32))
case protoreflect.Int64Kind, protoreflect.Sint64Kind, protoreflect.Sfixed64Kind:
return unmarshalValue(trimQuote(in), new(int64))
case protoreflect.Uint32Kind, protoreflect.Fixed32Kind:
return unmarshalValue(trimQuote(in), new(uint32))
case protoreflect.Uint64Kind, protoreflect.Fixed64Kind:
return unmarshalValue(trimQuote(in), new(uint64))
case protoreflect.FloatKind:
if f, ok := nonFinite[string(in)]; ok {
return protoreflect.ValueOfFloat32(float32(f)), nil
}
return unmarshalValue(trimQuote(in), new(float32))
case protoreflect.DoubleKind:
if f, ok := nonFinite[string(in)]; ok {
return protoreflect.ValueOfFloat64(float64(f)), nil
}
return unmarshalValue(trimQuote(in), new(float64))
case protoreflect.StringKind:
return unmarshalValue(in, new(string))
case protoreflect.BytesKind:
return unmarshalValue(in, new([]byte))
case protoreflect.EnumKind:
if hasPrefixAndSuffix('"', in, '"') {
vd := fd.Enum().Values().ByName(protoreflect.Name(trimQuote(in)))
if vd == nil {
return v, fmt.Errorf("unknown value %q for enum %s", in, fd.Enum().FullName())
}
return protoreflect.ValueOfEnum(vd.Number()), nil
}
return unmarshalValue(in, new(protoreflect.EnumNumber))
case protoreflect.MessageKind, protoreflect.GroupKind:
err := u.unmarshalMessage(v.Message(), in)
return v, err
default:
panic(fmt.Sprintf("invalid kind %v", fd.Kind()))
}
}
func unmarshalValue(in []byte, v interface{}) (protoreflect.Value, error) {
err := json.Unmarshal(in, v)
return protoreflect.ValueOf(reflect.ValueOf(v).Elem().Interface()), err
}
func unquoteString(in string) (out string, err error) {
err = json.Unmarshal([]byte(in), &out)
return out, err
}
func hasPrefixAndSuffix(prefix byte, in []byte, suffix byte) bool {
if len(in) >= 2 && in[0] == prefix && in[len(in)-1] == suffix {
return true
}
return false
}
// trimQuote is like unquoteString but simply strips surrounding quotes.
// This is incorrect, but is behavior done by the legacy implementation.
func trimQuote(in []byte) []byte {
if len(in) >= 2 && in[0] == '"' && in[len(in)-1] == '"' {
in = in[1 : len(in)-1]
}
return in
}