コード例 #1
0
// readAllStateCommon reads and unmarshals (given a function) all state into a
// list of core.State objects.
// XXX: move this to some common file
func readAllStateCommon(d core.StateDriver, baseKey string, sType core.State,
	unmarshal func([]byte, interface{}) error) ([]core.State, error) {
	stateType := reflect.TypeOf(sType)
	sliceType := reflect.SliceOf(stateType)
	values := reflect.MakeSlice(sliceType, 0, 1)

	byteValues, err := d.ReadAll(baseKey)
	if err != nil {
		return nil, err
	}
	for _, byteValue := range byteValues {
		value := reflect.New(stateType)
		err = unmarshal(byteValue, value.Interface())
		if err != nil {
			return nil, err
		}
		values = reflect.Append(values, value.Elem())
	}

	stateValues := []core.State{}
	for i := 0; i < values.Len(); i++ {
		// sanity checks
		if !values.Index(i).Elem().FieldByName("CommonState").IsValid() {
			return nil, core.Errorf("The state structure %v is missing core.CommonState",
				stateType)
		}
		//the following works as every core.State is expected to embed core.CommonState struct
		values.Index(i).Elem().FieldByName("CommonState").FieldByName("StateDriver").Set(reflect.ValueOf(d))
		stateValue := values.Index(i).Interface().(core.State)
		stateValues = append(stateValues, stateValue)
	}
	return stateValues, nil
}