Fix potential data race in Column.fieldPath (#21)

column.go

@@ -32,7 +32,6 @@ type Column struct {
 	IsDeleted       bool
 	IsCascade       bool
 	IsVersion       bool
-	fieldPath       []string
 	DefaultIsEmpty  bool
 	EnumOptions     map[string]int
 	SetOptions      map[string]int
@@ -59,7 +58,6 @@ func NewColumn(name, fieldName string, sqlType SQLType, len1, len2 int, nullable
 		IsDeleted:       false,
 		IsCascade:       false,
 		IsVersion:       false,
-		fieldPath:       nil,
 		DefaultIsEmpty:  false,
 		EnumOptions:     make(map[string]int),
 	}
@@ -121,32 +119,30 @@ func (col *Column) ValueOf(bean interface{}) (*reflect.Value, error) {
 
 func (col *Column) ValueOfV(dataStruct *reflect.Value) (*reflect.Value, error) {
 	var fieldValue reflect.Value
-	if col.fieldPath == nil {
-		col.fieldPath = strings.Split(col.FieldName, ".")
-	}
+	fieldPath := strings.Split(col.FieldName, ".")
 
 	if dataStruct.Type().Kind() == reflect.Map {
-		keyValue := reflect.ValueOf(col.fieldPath[len(col.fieldPath)-1])
+		keyValue := reflect.ValueOf(fieldPath[len(fieldPath)-1])
 		fieldValue = dataStruct.MapIndex(keyValue)
 		return &fieldValue, nil
 	} else if dataStruct.Type().Kind() == reflect.Interface {
 		structValue := reflect.ValueOf(dataStruct.Interface())
 		dataStruct = &structValue
 	}
 
-	level := len(col.fieldPath)
-	fieldValue = dataStruct.FieldByName(col.fieldPath[0])
+	level := len(fieldPath)
+	fieldValue = dataStruct.FieldByName(fieldPath[0])
 	for i := 0; i < level-1; i++ {
 		if !fieldValue.IsValid() {
 			break
 		}
 		if fieldValue.Kind() == reflect.Struct {
-			fieldValue = fieldValue.FieldByName(col.fieldPath[i+1])
+			fieldValue = fieldValue.FieldByName(fieldPath[i+1])
 		} else if fieldValue.Kind() == reflect.Ptr {
 			if fieldValue.IsNil() {
 				fieldValue.Set(reflect.New(fieldValue.Type().Elem()))
 			}
-			fieldValue = fieldValue.Elem().FieldByName(col.fieldPath[i+1])
+			fieldValue = fieldValue.Elem().FieldByName(fieldPath[i+1])
 		} else {
 			return nil, fmt.Errorf("field  %v is not valid", col.FieldName)
 		}