lib/etorrent-1.0/src/etorrent_path_map.erl

   1 %%%-------------------------------------------------------------------
   2 %%% File    : etorrent_path_map.erl
   3 %%% Author  : Jesper Louis Andersen <>
   4 %%% Description : Manipulate the #path_map table
   5 %%%
   6 %%% Created :  6 Jul 2008 by Jesper Louis Andersen <>
   7 %%%-------------------------------------------------------------------
   8 -module(etorrent_path_map).
   9
  10 -include_lib("stdlib/include/qlc.hrl").
  11 -include("etorrent_mnesia_table.hrl").
  12
  13 %% API
  14 -export([select/2, delete/1]).
  15
  16 %%====================================================================
  17 %% API
  18 %%====================================================================
  19 %%--------------------------------------------------------------------
  20 %% Function: select(Path) -> Id,
  21 %%           select(Id)   -> Path
  22 %% Description: Bi-directionally lookup on {Path, Id} pairs. If a non-
  23 %%   exsisting path is selected, we add it as a side-effect
  24 %%--------------------------------------------------------------------
  25 select(Id, TorrentId) when is_integer(Id) ->
  26     [R] = mnesia:dirty_read(path_map, {Id, TorrentId}),
  27     R;
  28 select(Path, TorrentId) when is_list(Path) ->
  29     case mnesia:dirty_index_read(path_map, Path, #path_map.path) of
  30         [] ->
  31             Id = etorrent_counters:next(path_map),
  32             ok = mnesia:dirty_write(#path_map{ id = {Id, TorrentId},
  33                                                path = Path}),
  34             Id;
  35         [R] ->
  36             {Id, _TorrentId} = R#path_map.id,
  37             Id
  38     end.
  39
  40 %%--------------------------------------------------------------------
  41 %% Function: delete(TorrentId) -> ok
  42 %% Description: Delete entries from the pathmap based on the TorrentId
  43 %%--------------------------------------------------------------------
  44 delete(TorrentId) when is_integer(TorrentId) ->
  45     MatchHead = #path_map { id = {'_', TorrentId}, _ = '_' },
  46     lists:foreach(fun(Obj) -> mnesia:dirty_delete_object(Obj) end,
  47                   mnesia:dirty_select(path_map, [{MatchHead, [], ['$_']}])),
  48     ok.
  49
  50 %%====================================================================
  51 %% Internal functions
  52 %%====================================================================