anchor.diff:                                                                   next_offset = NewNextOffset},
                          State);
           {error, eof} ->
  -            ok;
  +            {ok, CompactParams#compact_params.num_of_active_object};
           Error ->
               Error
       end;
  
positive.code: 
                            case leo_object_storage_haystack:open(TmpPath) of
                                {ok, [TmpWriteHandler, TmpReadHandler]} ->
  
                                    case do_stats(MetaDBId, StorageInfo) of
                                        {ok, #storage_stats{active_num = ActiveObjs}} ->
                                            {ok, State#state{object_storage = StorageInfo#backend_info{
                                                                                tmp_file_path_raw = TmpPath,
                                                                                tmp_write_handler = TmpWriteHandler,
                                                                                tmp_read_handler  = TmpReadHandler},
                                                             num_of_objects = ActiveObjs}};
                                        Error ->
                                            {Error, State}
                                    end;
                                Error ->
                                    {Error, State}
                            end;
  
negative.code: is_deleted_rec(_MetaDBId,_Meta0,_Meta1) ->
      false.
  
  %% @doc Reduce unnecessary objects from object-container.
  %% @private
  -spec(do_compact(#metadata{}, #compact_params{}, #state{}) ->
  