示例#1
0
// marshalObject writes a struct to the Writer.
func (m *Marshaler) marshalObject(out *errWriter, v proto.Message, indent string) error {
	out.write("{")
	if m.Indent != "" {
		out.write("\n")
	}

	s := reflect.ValueOf(v).Elem()
	firstField := true
	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)
		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.(extendableProto); ok {
		extensions := proto.RegisteredExtensions(v)
		extensionMap := ep.ExtensionMap()
		// Sort extensions for stable output.
		ids := make([]int32, 0, len(extensionMap))
		for id := range extensionMap {
			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.OrigName = 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
}
示例#2
0
// jsonProperties returns parsed proto.Properties for the field.
func jsonProperties(f reflect.StructField) *proto.Properties {
	var prop proto.Properties
	prop.Init(f.Type, f.Name, f.Tag.Get("protobuf"), &f)
	return &prop
}