anchor.diff:  
   %% API
   -export([new_torrent/2, find_torrents_by_file/1, cleanup_torrent_by_pid/1,
  -	 store_info_hash/3, set_info_hash_state/2]).
  +	 store_info_hash/3, set_info_hash_state/2, select_info_hash_pids/1]).
   
   %%====================================================================
   %% API
  
positive.code:     Res.
  
  %%--------------------------------------------------------------------
  %% Internal functions
  %%--------------------------------------------------------------------
  
  
negative.code: cleanup_torrent_by_pid(Pid) ->
      F = fun() ->
  		Query = qlc:q([T#tracking_map.filename || T <- mnesia:table(tracking_map),
  							  T#tracking_map.supervisor_pid =:= Pid]),
  		lists:foreach(fun (F) -> mnesia:delete(tracking_map, F, write) end, qlc:e(Query))
  	end,
      mnesia:transaction(F).
  