// jsonProperties returns parsed proto.Properties for the field and corrects JSONName attribute.
func jsonProperties(f reflect.StructField, origName bool) *proto.Properties {
	var prop proto.Properties
	prop.Init(f.Type, f.Name, f.Tag.Get("protobuf"), &f)
	if origName || prop.JSONName == "" {
		prop.JSONName = prop.OrigName
	}
	return &prop
}

func acceptedJSONFieldNames(f reflect.StructField) fieldNames {
	var prop proto.Properties
	prop.Init(f.Type, f.Name, f.Tag.Get("protobuf"), &f)
	opts := fieldNames{orig: prop.OrigName, camel: prop.OrigName}
	if prop.JSONName != "" {
		opts.camel = prop.JSONName
	}
	return opts
}

// 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()
	writeBeforeField := ""
	for i := 0; i < s.NumField(); i++ {
		value := s.Field(i)
		valueField := s.Type().Field(i)
		if strings.HasPrefix(valueField.Name, "XXX_") {
			continue
		}
		fieldName := jsonFieldName(valueField)

		// TODO: proto3 objects should have default values omitted.

		// 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
			}
		}

		// 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)

			var p proto.Properties
			p.Parse(sv.Type().Field(0).Tag.Get("protobuf"))
			fieldName = p.OrigName
		}

		out.write(writeBeforeField)
		if m.Indent != "" {
			out.write(indent)
			out.write(m.Indent)
		}
		out.write(`"`)
		out.write(fieldName)
		out.write(`":`)
		if m.Indent != "" {
			out.write(" ")
		}

		if err := m.marshalValue(out, value, valueField, indent); err != nil {
			return err
		}

		if m.Indent != "" {
			writeBeforeField = ",\n"
		} else {
			writeBeforeField = ","
		}
	}

	if m.Indent != "" {
		out.write("\n")
		out.write(indent)
	}
	out.write("}")
	return out.err
}

// jsonFieldName returns the field name to use.
func jsonFieldName(f reflect.StructField) string {
	var prop proto.Properties
	prop.Init(f.Type, f.Name, f.Tag.Get("protobuf"), &f)
	return prop.OrigName
}

// marshalObject writes a struct to the Writer.
func (m *Marshaler) marshalObject(out *errWriter, v proto.Message, indent string) error {
	s := reflect.ValueOf(v).Elem()

	// Handle well-known types.
	type wkt interface {
		XXX_WellKnownType() string
	}
	if wkt, ok := v.(wkt); 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 "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 "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
		}
	}

	out.write("{")
	if m.Indent != "" {
		out.write("\n")
	}

	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, m.OrigName)
		if !firstField {
			m.writeSep(out)
//.........这里部分代码省略.........

// 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
		}

		// TODO: proto3 objects should have default values omitted.

		// 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
			}
		}

		// 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 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
}

// 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
}

// unmarshalValue converts/copies a value into the target.
func unmarshalValue(target reflect.Value, inputValue json.RawMessage) error {
	targetType := target.Type()

	// Allocate memory for pointer fields.
	if targetType.Kind() == reflect.Ptr {
		target.Set(reflect.New(targetType.Elem()))
		return unmarshalValue(target.Elem(), inputValue)
	}

	// Handle nested messages.
	if targetType.Kind() == reflect.Struct {
		var jsonFields map[string]json.RawMessage
		if err := json.Unmarshal(inputValue, &jsonFields); err != nil {
			return err
		}

		for i := 0; i < target.NumField(); i++ {
			ft := target.Type().Field(i)
			if strings.HasPrefix(ft.Name, "XXX_") {
				continue
			}
			fieldName := jsonFieldName(ft)

			if valueForField, ok := jsonFields[fieldName]; ok {
				if err := unmarshalValue(target.Field(i), valueForField); err != nil {
					return err
				}
				delete(jsonFields, fieldName)
			}
		}
		// Check for any oneof fields.
		// This might be slow; we can optimise it if it becomes a problem.
		type oneofMessage interface {
			XXX_OneofFuncs() (func(proto.Message, *proto.Buffer) error, func(proto.Message, int, int, *proto.Buffer) (bool, error), []interface{})
		}
		var oneofTypes []interface{}
		if om, ok := reflect.Zero(reflect.PtrTo(targetType)).Interface().(oneofMessage); ok {
			_, _, oneofTypes = om.XXX_OneofFuncs()
		}
		for fname, raw := range jsonFields {
			for _, oot := range oneofTypes {
				sp := reflect.ValueOf(oot).Type() // *T
				var props proto.Properties
				props.Parse(sp.Elem().Field(0).Tag.Get("protobuf"))
				if props.OrigName != fname {
					continue
				}
				nv := reflect.New(sp.Elem())
				// There will be exactly one interface field that
				// this new value is assignable to.
				for i := 0; i < targetType.NumField(); i++ {
					f := targetType.Field(i)
					if f.Type.Kind() != reflect.Interface {
						continue
					}
					if !nv.Type().AssignableTo(f.Type) {
						continue
					}
					target.Field(i).Set(nv)
					break
				}
				if err := unmarshalValue(nv.Elem().Field(0), raw); err != nil {
					return err
				}
				delete(jsonFields, fname)
				break
			}
		}
		if 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 (which aren't encoded bytes)
	if targetType != byteArrayType && targetType.Kind() == reflect.Slice {
		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 := unmarshalValue(target.Index(i), slc[i]); err != nil {
				return err
			}
		}
		return nil
	}

	// Handle maps (whose keys are always strings)
	if targetType.Kind() == reflect.Map {
		var mp map[string]json.RawMessage
//.........这里部分代码省略.........