anchor.diff:    {reply, Reply, stamp(Key, read, State)};
   handle_call(#edis_command{cmd = <<"HLEN">>, args = [Key]}, _From, State) ->
     Reply =
  -    case get_item(State#state.backend_mod, State#state.backend_ref, hash, Key) of
  +    case get_item(State, hash, Key) of
         not_found -> {ok, 0};
         {error, Reason} -> {error, Reason};
         Item -> {ok, dict:size(Item#edis_item.value)}
  
positive.code:   {reply, Reply, stamp([Key, NewKey], write, State)};
  handle_call(#edis_command{cmd = <<"RENAMENX">>, args = [Key, NewKey]}, _From, State) ->
    {Reply, Action} =
      case get_item(State#state.backend_mod, State#state.backend_ref, any, Key) of
        not_found ->
          {{error, no_such_key}, none};
        {error, Reason} ->
          {{error, Reason}, read};
        Item ->
          case exists_item(State#state.backend_mod, State#state.backend_ref, NewKey) of
            true ->
              {{ok, false}, read};
            false ->
  
negative.code:   {reply, Reply, stamp(Key, Action, State)};
  handle_call(#edis_command{cmd = <<"-INTERNAL-RECV">>, args = [Item]}, _From, State) ->
    {Reply, Action} =
      case exists_item(State, Item#edis_item.key) of
        true -> {{error, found}, read};
        false -> {db_put(
                    Item#edis_item.key, 
  