lib/etorrent-1.0/src/etorrent_piece_diskstate.erl

   1 %%%-------------------------------------------------------------------
   2 %%% File    : etorrent_piece_diskstate.erl
   3 %%% Author  : Jesper Louis Andersen <jlouis@ogre.home>
   4 %%% Description : Manipulation of the #piece_diskstate table.
   5 %%%
   6 %%% Created : 16 Jul 2008 by Jesper Louis Andersen <jlouis@ogre.home>
   7 %%%-------------------------------------------------------------------
   8 -module(etorrent_piece_diskstate).
   9
  10 -include_lib("stdlib/include/qlc.hrl").
  11 -include("etorrent_mnesia_table.hrl").
  12
  13 %% API
  14 -export([new/2, prune/1, select/1]).
  15
  16 %%====================================================================
  17 %% API
  18 %%====================================================================
  19 %%--------------------------------------------------------------------
  20 %% Function:
  21 %% Description:
  22 %%--------------------------------------------------------------------
  23
  24 %%--------------------------------------------------------------------
  25 %% Function: new/2 -> ok
  26 %% Args: Filename ::= string() (filename of torrent)
  27 %%       State ::= seeding | {bitfield, BF}
  28 %%
  29 %%       BF ::= binary() (bitfield)
  30 %% Description: Add/Update the Filenames persistent disk state
  31 %%--------------------------------------------------------------------
  32 new(Filename, State) ->
  33     mnesia:dirty_write(#piece_diskstate { filename = Filename,
  34                                           state = State }).
  35
  36 %%--------------------------------------------------------------------
  37 %% Function: prune/1 -> ok
  38 %% Args: Filenames ::= set() (of filenames)
  39 %% Description: Prune the table for any entry not in the FN set.
  40 %%--------------------------------------------------------------------
  41 prune(Filenames) ->
  42     {atomic, Kill} =
  43         mnesia:transaction(
  44           fun () ->
  45                   Q = qlc:q([E#piece_diskstate.filename
  46                              || E <- mnesia:table(piece_diskstate),
  47                                 sets:is_element(E#piece_diskstate.filename,
  48                                                 Filenames)]),
  49                   qlc:e(Q)
  50           end),
  51     lists:foreach(fun (T) -> mnesia:dirty_delete(piece_diskstate, T) end,
  52                   Kill),
  53     ok.
  54
  55 %%--------------------------------------------------------------------
  56 %% Function: select/1
  57 %% Args: Filename ::= string()
  58 %% Description: Select the row matching the filename
  59 %%--------------------------------------------------------------------
  60 select(FN) ->
  61     mnesia:dirty_read(piece_diskstate, FN).
  62
  63 %%====================================================================
  64 %% Internal functions
  65 %%====================================================================