// Empty returns a new proto.Message of the type specified in a
// google.protobuf.Any message. It returns an error if corresponding message
// type isn't linked in.
func EmptyAny(any *Any) (proto.Message, error) {
aname, err := AnyMessageName(any)
if err != nil {
return nil, err
}
t := proto.MessageType(aname)
if t == nil {
return nil, fmt.Errorf("any: message type %q isn't linked in", aname)
}
return reflect.New(t.Elem()).Interface().(proto.Message), nil
}
func (m *Marshaler) marshalAny(out *errWriter, any proto.Message, indent string) error {
// "If the Any contains a value that has a special JSON mapping,
// it will be converted as follows: {"@type": xxx, "value": yyy}.
// Otherwise, the value will be converted into a JSON object,
// and the "@type" field will be inserted to indicate the actual data type."
v := reflect.ValueOf(any).Elem()
turl := v.Field(0).String()
val := v.Field(1).Bytes()
// Only the part of type_url after the last slash is relevant.
mname := turl
if slash := strings.LastIndex(mname, "/"); slash >= 0 {
mname = mname[slash+1:]
}
mt := proto.MessageType(mname)
if mt == nil {
return fmt.Errorf("unknown message type %q", mname)
}
msg := reflect.New(mt.Elem()).Interface().(proto.Message)
if err := proto.Unmarshal(val, msg); err != nil {
return err
}
if _, ok := msg.(isWkt); ok {
out.write("{")
if m.Indent != "" {
out.write("\n")
}
if err := m.marshalTypeURL(out, indent, turl); err != nil {
return err
}
m.writeSep(out)
if m.Indent != "" {
out.write(indent)
out.write(m.Indent)
out.write(`"value": `)
} else {
out.write(`"value":`)
}
if err := m.marshalObject(out, msg, indent+m.Indent, ""); err != nil {
return err
}
if m.Indent != "" {
out.write("\n")
out.write(indent)
}
out.write("}")
return out.err
}
return m.marshalObject(out, msg, indent, turl)
}
// marshalValue writes the value to the Writer.
func (m *Marshaler) marshalValue(out *errWriter, prop *proto.Properties, v reflect.Value, indent string) error {
v = reflect.Indirect(v)
// Handle repeated elements.
if v.Kind() == reflect.Slice && v.Type().Elem().Kind() != reflect.Uint8 {
out.write("[")
comma := ""
for i := 0; i < v.Len(); i++ {
sliceVal := v.Index(i)
out.write(comma)
if m.Indent != "" {
out.write("\n")
out.write(indent)
out.write(m.Indent)
out.write(m.Indent)
}
if err := m.marshalValue(out, prop, sliceVal, indent+m.Indent); err != nil {
return err
}
comma = ","
}
if m.Indent != "" {
out.write("\n")
out.write(indent)
out.write(m.Indent)
}
out.write("]")
return out.err
}
// Handle well-known types.
// Most are handled up in marshalObject (because 99% are messages).
if wkt, ok := v.Interface().(isWkt); ok {
switch wkt.XXX_WellKnownType() {
case "NullValue":
out.write("null")
return out.err
}
}
if t, ok := v.Interface().(time.Time); ok {
ts, err := types.TimestampProto(t)
if err != nil {
return err
}
return m.marshalValue(out, prop, reflect.ValueOf(ts), indent)
}
if d, ok := v.Interface().(time.Duration); ok {
dur := types.DurationProto(d)
return m.marshalValue(out, prop, reflect.ValueOf(dur), indent)
}
// Handle enumerations.
if !m.EnumsAsInts && prop.Enum != "" {
// Unknown enum values will are stringified by the proto library as their
// value. Such values should _not_ be quoted or they will be interpreted
// as an enum string instead of their value.
enumStr := v.Interface().(fmt.Stringer).String()
var valStr string
if v.Kind() == reflect.Ptr {
valStr = strconv.Itoa(int(v.Elem().Int()))
} else {
valStr = strconv.Itoa(int(v.Int()))
}
if m, ok := v.Interface().(interface {
MarshalJSON() ([]byte, error)
}); ok {
data, err := m.MarshalJSON()
if err != nil {
return err
}
enumStr = string(data)
enumStr, err = strconv.Unquote(enumStr)
if err != nil {
return err
}
}
isKnownEnum := enumStr != valStr
if isKnownEnum {
out.write(`"`)
}
out.write(enumStr)
if isKnownEnum {
out.write(`"`)
}
return out.err
}
// Handle nested messages.
if v.Kind() == reflect.Struct {
i := v
if v.CanAddr() {
i = v.Addr()
} else {
i = reflect.New(v.Type())
i.Elem().Set(v)
}
iface := i.Interface()
if iface == nil {
out.write(`null`)
return out.err
}
pm, ok := iface.(proto.Message)
if !ok {
if prop.CustomType == "" {
return fmt.Errorf("%v does not implement proto.Message", v.Type())
}
t := proto.MessageType(prop.CustomType)
if t == nil || !i.Type().ConvertibleTo(t) {
return fmt.Errorf("%v declared custom type %s but it is not convertible to %v", v.Type(), prop.CustomType, t)
}
pm = i.Convert(t).Interface().(proto.Message)
}
return m.marshalObject(out, pm, indent+m.Indent, "")
}
// Handle maps.
// Since Go randomizes map iteration, we sort keys for stable output.
if v.Kind() == reflect.Map {
out.write(`{`)
keys := v.MapKeys()
sort.Sort(mapKeys(keys))
for i, k := range keys {
if i > 0 {
out.write(`,`)
}
if m.Indent != "" {
out.write("\n")
out.write(indent)
out.write(m.Indent)
out.write(m.Indent)
}
b, err := json.Marshal(k.Interface())
if err != nil {
return err
}
s := string(b)
// If the JSON is not a string value, encode it again to make it one.
if !strings.HasPrefix(s, `"`) {
b, err := json.Marshal(s)
if err != nil {
return err
}
s = string(b)
}
out.write(s)
out.write(`:`)
if m.Indent != "" {
out.write(` `)
}
if err := m.marshalValue(out, prop, v.MapIndex(k), indent+m.Indent); err != nil {
return err
}
}
if m.Indent != "" {
out.write("\n")
out.write(indent)
out.write(m.Indent)
}
out.write(`}`)
return out.err
}
// Default handling defers to the encoding/json library.
b, err := json.Marshal(v.Interface())
if err != nil {
return err
}
needToQuote := string(b[0]) != `"` && (v.Kind() == reflect.Int64 || v.Kind() == reflect.Uint64)
if needToQuote {
out.write(`"`)
}
out.write(string(b))
if needToQuote {
out.write(`"`)
}
return out.err
}