// unmarshalValue converts/copies a value into the target.
// prop may be nil.
func (u *Unmarshaler) unmarshalValue(target reflect.Value, inputValue json.RawMessage, prop *proto.Properties) error {
// Prefer specialized marshalers if available
if ulr, ok := target.Addr().Interface().(json.Unmarshaler); ok {
return ulr.UnmarshalJSON(inputValue)
}
targetType := target.Type()
// Allocate memory for pointer fields.
if targetType.Kind() == reflect.Ptr {
target.Set(reflect.New(targetType.Elem()))
return u.unmarshalValue(target.Elem(), inputValue, prop)
}
// Handle well-known types.
if wkt, ok := target.Addr().Interface().(isWkt); ok {
switch wkt.XXX_WellKnownType() {
case "DoubleValue", "FloatValue", "Int64Value", "UInt64Value",
"Int32Value", "UInt32Value", "BoolValue", "StringValue", "BytesValue":
// "Wrappers use the same representation in JSON
// as the wrapped primitive type, except that null is allowed."
// encoding/json will turn JSON `null` into Go `nil`,
// so we don't have to do any extra work.
return u.unmarshalValue(target.Field(0), inputValue, prop)
case "Any":
return fmt.Errorf("unmarshaling Any not supported yet")
case "Duration":
unq, err := strconv.Unquote(string(inputValue))
if err != nil {
return err
}
d, err := time.ParseDuration(unq)
if err != nil {
return fmt.Errorf("bad Duration: %v", err)
}
ns := d.Nanoseconds()
s := ns / 1e9
ns %= 1e9
target.Field(0).SetInt(s)
target.Field(1).SetInt(ns)
return nil
case "Timestamp":
unq, err := strconv.Unquote(string(inputValue))
if err != nil {
return err
}
t, err := time.Parse(time.RFC3339Nano, unq)
if err != nil {
return fmt.Errorf("bad Timestamp: %v", err)
}
target.Field(0).SetInt(int64(t.Unix()))
target.Field(1).SetInt(int64(t.Nanosecond()))
return nil
}
}
if t, ok := target.Addr().Interface().(*time.Time); ok {
ts := &types.Timestamp{}
if err := u.unmarshalValue(reflect.ValueOf(ts).Elem(), inputValue, prop); err != nil {
return err
}
tt, err := types.TimestampFromProto(ts)
if err != nil {
return err
}
*t = tt
return nil
}
if d, ok := target.Addr().Interface().(*time.Duration); ok {
dur := &types.Duration{}
if err := u.unmarshalValue(reflect.ValueOf(dur).Elem(), inputValue, prop); err != nil {
return err
}
dd, err := types.DurationFromProto(dur)
if err != nil {
return err
}
*d = dd
return nil
}
// Handle enums, which have an underlying type of int32,
// and may appear as strings.
// The case of an enum appearing as a number is handled
// at the bottom of this function.
if inputValue[0] == '"' && prop != nil && prop.Enum != "" {
vmap := proto.EnumValueMap(prop.Enum)
// Don't need to do unquoting; valid enum names
// are from a limited character set.
s := inputValue[1 : len(inputValue)-1]
n, ok := vmap[string(s)]
if !ok {
return fmt.Errorf("unknown value %q for enum %s", s, prop.Enum)
}
if target.Kind() == reflect.Ptr { // proto2
target.Set(reflect.New(targetType.Elem()))
target = target.Elem()
}
target.SetInt(int64(n))
return nil
}
// Handle nested messages.
if targetType.Kind() == reflect.Struct {
var jsonFields map[string]json.RawMessage
if err := json.Unmarshal(inputValue, &jsonFields); err != nil {
return err
}
consumeField := func(prop *proto.Properties) (json.RawMessage, bool) {
// Be liberal in what names we accept; both orig_name and camelName are okay.
fieldNames := acceptedJSONFieldNames(prop)
vOrig, okOrig := jsonFields[fieldNames.orig]
vCamel, okCamel := jsonFields[fieldNames.camel]
if !okOrig && !okCamel {
return nil, false
}
// If, for some reason, both are present in the data, favour the camelName.
var raw json.RawMessage
if okOrig {
raw = vOrig
delete(jsonFields, fieldNames.orig)
}
if okCamel {
raw = vCamel
delete(jsonFields, fieldNames.camel)
}
return raw, true
}
sprops := proto.GetProperties(targetType)
for i := 0; i < target.NumField(); i++ {
ft := target.Type().Field(i)
if strings.HasPrefix(ft.Name, "XXX_") {
continue
}
valueForField, ok := consumeField(sprops.Prop[i])
if !ok {
continue
}
if err := u.unmarshalValue(target.Field(i), valueForField, sprops.Prop[i]); err != nil {
return err
}
}
// Check for any oneof fields.
if len(jsonFields) > 0 {
for _, oop := range sprops.OneofTypes {
raw, ok := consumeField(oop.Prop)
if !ok {
continue
}
nv := reflect.New(oop.Type.Elem())
target.Field(oop.Field).Set(nv)
if err := u.unmarshalValue(nv.Elem().Field(0), raw, oop.Prop); err != nil {
return err
}
}
}
if !u.AllowUnknownFields && len(jsonFields) > 0 {
// Pick any field to be the scapegoat.
var f string
for fname := range jsonFields {
f = fname
break
}
return fmt.Errorf("unknown field %q in %v", f, targetType)
}
return nil
}
// Handle arrays
if targetType.Kind() == reflect.Slice {
if targetType.Elem().Kind() == reflect.Uint8 {
outRef := reflect.New(targetType)
outVal := outRef.Interface()
//CustomType with underlying type []byte
if _, ok := outVal.(interface {
UnmarshalJSON([]byte) error
}); ok {
if err := json.Unmarshal(inputValue, outVal); err != nil {
return err
}
target.Set(outRef.Elem())
return nil
}
// Special case for encoded bytes. Pre-go1.5 doesn't support unmarshalling
// strings into aliased []byte types.
// https://github.com/golang/go/commit/4302fd0409da5e4f1d71471a6770dacdc3301197
// https://github.com/golang/go/commit/c60707b14d6be26bf4213114d13070bff00d0b0a
var out []byte
if err := json.Unmarshal(inputValue, &out); err != nil {
return err
}
target.SetBytes(out)
return nil
}
var slc []json.RawMessage
if err := json.Unmarshal(inputValue, &slc); err != nil {
return err
}
len := len(slc)
target.Set(reflect.MakeSlice(targetType, len, len))
for i := 0; i < len; i++ {
if err := u.unmarshalValue(target.Index(i), slc[i], prop); err != nil {
return err
}
}
return nil
}
// Handle maps (whose keys are always strings)
if targetType.Kind() == reflect.Map {
var mp map[string]json.RawMessage
if err := json.Unmarshal(inputValue, &mp); err != nil {
return err
}
target.Set(reflect.MakeMap(targetType))
var keyprop, valprop *proto.Properties
if prop != nil {
// These could still be nil if the protobuf metadata is broken somehow.
// TODO: This won't work because the fields are unexported.
// We should probably just reparse them.
//keyprop, valprop = prop.mkeyprop, prop.mvalprop
}
for ks, raw := range mp {
// Unmarshal map key. The core json library already decoded the key into a
// string, so we handle that specially. Other types were quoted post-serialization.
var k reflect.Value
if targetType.Key().Kind() == reflect.String {
k = reflect.ValueOf(ks)
} else {
k = reflect.New(targetType.Key()).Elem()
if err := u.unmarshalValue(k, json.RawMessage(ks), keyprop); err != nil {
return err
}
}
if !k.Type().AssignableTo(targetType.Key()) {
k = k.Convert(targetType.Key())
}
// Unmarshal map value.
v := reflect.New(targetType.Elem()).Elem()
if err := u.unmarshalValue(v, raw, valprop); err != nil {
return err
}
target.SetMapIndex(k, v)
}
return nil
}
// 64-bit integers can be encoded as strings. In this case we drop
// the quotes and proceed as normal.
isNum := targetType.Kind() == reflect.Int64 || targetType.Kind() == reflect.Uint64
if isNum && strings.HasPrefix(string(inputValue), `"`) {
inputValue = inputValue[1 : len(inputValue)-1]
}
// Use the encoding/json for parsing other value types.
return json.Unmarshal(inputValue, target.Addr().Interface())
}
// marshalObject writes a struct to the Writer.
func (m *Marshaler) marshalObject(out *errWriter, v proto.Message, indent, typeURL string) error {
// Prefer specialized marshalers if available
if mlr, ok := v.(json.Marshaler); ok {
bs, err := mlr.MarshalJSON()
if err != nil {
return err
}
if out.err != nil {
return out.err
}
_, out.err = out.writer.Write(bs)
return out.err
}
s := reflect.ValueOf(v).Elem()
// Handle well-known types.
if wkt, ok := v.(isWkt); ok {
switch wkt.XXX_WellKnownType() {
case "DoubleValue", "FloatValue", "Int64Value", "UInt64Value",
"Int32Value", "UInt32Value", "BoolValue", "StringValue", "BytesValue":
// "Wrappers use the same representation in JSON
// as the wrapped primitive type, ..."
sprop := proto.GetProperties(s.Type())
return m.marshalValue(out, sprop.Prop[0], s.Field(0), indent)
case "Any":
// Any is a bit more involved.
return m.marshalAny(out, v, indent)
case "Duration":
// "Generated output always contains 3, 6, or 9 fractional digits,
// depending on required precision."
s, ns := s.Field(0).Int(), s.Field(1).Int()
d := time.Duration(s)*time.Second + time.Duration(ns)*time.Nanosecond
x := fmt.Sprintf("%.9f", d.Seconds())
x = strings.TrimSuffix(x, "000")
x = strings.TrimSuffix(x, "000")
out.write(`"`)
out.write(x)
out.write(`s"`)
return out.err
case "Struct":
// Let marshalValue handle the `fields` map.
// TODO: pass the correct Properties if needed.
return m.marshalValue(out, &proto.Properties{}, s.Field(0), indent)
case "Timestamp":
// "RFC 3339, where generated output will always be Z-normalized
// and uses 3, 6 or 9 fractional digits."
s, ns := s.Field(0).Int(), s.Field(1).Int()
t := time.Unix(s, ns).UTC()
// time.RFC3339Nano isn't exactly right (we need to get 3/6/9 fractional digits).
x := t.Format("2006-01-02T15:04:05.000000000")
x = strings.TrimSuffix(x, "000")
x = strings.TrimSuffix(x, "000")
out.write(`"`)
out.write(x)
out.write(`Z"`)
return out.err
case "Value":
// Value has a single oneof.
kind := s.Field(0)
if kind.IsNil() {
// "absence of any variant indicates an error"
return errors.New("nil Value")
}
// oneof -> *T -> T -> T.F
x := kind.Elem().Elem().Field(0)
// TODO: pass the correct Properties if needed.
return m.marshalValue(out, &proto.Properties{}, x, indent)
}
}
out.write("{")
if m.Indent != "" {
out.write("\n")
}
firstField := true
if typeURL != "" {
if err := m.marshalTypeURL(out, indent, typeURL); err != nil {
return err
}
firstField = false
}
for i := 0; i < s.NumField(); i++ {
value := s.Field(i)
valueField := s.Type().Field(i)
if strings.HasPrefix(valueField.Name, "XXX_") {
continue
}
// IsNil will panic on most value kinds.
switch value.Kind() {
case reflect.Chan, reflect.Func, reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice:
if value.IsNil() {
continue
}
}
if !m.EmitDefaults {
switch value.Kind() {
case reflect.Bool:
if !value.Bool() {
continue
}
case reflect.Int32, reflect.Int64:
if value.Int() == 0 {
continue
}
case reflect.Uint32, reflect.Uint64:
if value.Uint() == 0 {
continue
}
case reflect.Float32, reflect.Float64:
if value.Float() == 0 {
continue
}
case reflect.String:
if value.Len() == 0 {
continue
}
}
}
// Oneof fields need special handling.
if valueField.Tag.Get("protobuf_oneof") != "" {
// value is an interface containing &T{real_value}.
sv := value.Elem().Elem() // interface -> *T -> T
value = sv.Field(0)
valueField = sv.Type().Field(0)
}
prop := jsonProperties(valueField, m.OrigName)
if !firstField {
m.writeSep(out)
}
// If the map value is a cast type, it may not implement proto.Message, therefore
// allow the struct tag to declare the underlying message type. Instead of changing
// the signatures of the child types (and because prop.mvalue is not public), use
// CustomType as a passer.
if value.Kind() == reflect.Map {
if tag := valueField.Tag.Get("protobuf"); tag != "" {
for _, v := range strings.Split(tag, ",") {
if !strings.HasPrefix(v, "castvaluetype=") {
continue
}
v = strings.TrimPrefix(v, "castvaluetype=")
prop.CustomType = v
break
}
}
}
if err := m.marshalField(out, prop, value, indent); err != nil {
return err
}
firstField = false
}
// Handle proto2 extensions.
if ep, ok := v.(proto.Message); ok {
extensions := proto.RegisteredExtensions(v)
// Sort extensions for stable output.
ids := make([]int32, 0, len(extensions))
for id, desc := range extensions {
if !proto.HasExtension(ep, desc) {
continue
}
ids = append(ids, id)
}
sort.Sort(int32Slice(ids))
for _, id := range ids {
desc := extensions[id]
if desc == nil {
// unknown extension
continue
}
ext, extErr := proto.GetExtension(ep, desc)
if extErr != nil {
return extErr
}
value := reflect.ValueOf(ext)
var prop proto.Properties
prop.Parse(desc.Tag)
prop.JSONName = fmt.Sprintf("[%s]", desc.Name)
if !firstField {
m.writeSep(out)
}
if err := m.marshalField(out, &prop, value, indent); err != nil {
return err
}
firstField = false
}
}
if m.Indent != "" {
out.write("\n")
out.write(indent)
}
out.write("}")
return out.err
}
