示例#1
0
文件: any.go 项目: maditya/protobuf
// 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
}
示例#2
0
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)
}
示例#3
0
// 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
}