modules/erl/euphorik_common.erl

   1 % coding: utf-8
   2 % Copyright 2008 Grégory Burri
   3 %
   4 % This file is part of Euphorik.
   5 %
   6 % Euphorik is free software: you can redistribute it and/or modify
   7 % it under the terms of the GNU General Public License as published by
   8 % the Free Software Foundation, either version 3 of the License, or
   9 % (at your option) any later version.
  10 %
  11 % Euphorik is distributed in the hope that it will be useful,
  12 % but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 % GNU General Public License for more details.
  15 %
  16 % You should have received a copy of the GNU General Public License
  17 % along with Euphorik.  If not, see <http://www.gnu.org/licenses/>.
  18 %
  19 % Module with some useful stuffs.
  20 % @author G.Burri
  21
  22
  23 -module(euphorik_common).
  24 -export([
  25    ceiling/1,
  26    delta_date_ms/2,
  27    delta_date_minute/2,
  28    serialize_ip/1,
  29    unserialize_ip/1
  30 ]).
  31
  32
  33 % Arrondi un float à l'entier supérieur.
  34 % Bizarre, cette fonction n'existe pas dans la stdlib.
  35 % Pas utilisé mais bon ca me fait de la peine de l'enlever.
  36 ceiling(X) ->
  37    T = trunc(X),
  38    case (X - T) of
  39       Neg when Neg < 0 -> T;
  40       Pos when Pos > 0 -> T + 1;
  41       _ -> T
  42    end.
  43
  44
  45 % Retourne la difference entre deux timestamp (erlang:now()) en miliseconde
  46 delta_date_ms(D1, D2) ->
  47    1000000000 * abs(element(1, D1) - element(1, D2)) + 1000 * abs(element(2, D1) - element(2, D2)) + trunc(abs(element(3, D1) - element(3, D2)) / 1000).
  48
  49
  50 % Retourne la différence entre deux timestamp (erlang:now) en minutes
  51 delta_date_minute(D1, D2) ->
  52    trunc(delta_date_ms(D1, D2) / 1000 / 60).
  53
  54
  55 serialize_ip(undefined) ->
  56    "<unknown IP>";
  57 serialize_ip(IP) ->
  58    lists:flatten(io_lib:format("~w.~w.~w.~w", tuple_to_list(IP))).
  59
  60
  61 unserialize_ip(IP) ->
  62    case io_lib:fread("~d.~d.~d.~d", IP) of
  63       {ok, [A, B, C, D], []} -> {A, B, C, D};
  64       _  -> erreur
  65    end.