shell/rb-play-order-random-by-age.c

   1 /*
   2  *  arch-tag: Implementation of random play order weighted by the time since last play
   3  *
   4  *  Copyright (C) 2003 Jeffrey Yasskin <jyasskin@mail.utexas.edu>
   5  *
   6  *  This program 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 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program 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 this program; if not, write to the Free Software
  18  *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA.
  19  *
  20  */
  21
  22 #include "rb-play-order-random-by-age.h"
  23
  24 #include "rhythmdb.h"
  25 #include <time.h>
  26 #include <math.h>
  27
  28 static void rb_random_play_order_by_age_class_init (RBRandomPlayOrderByAgeClass *klass);
  29
  30 static double rb_random_by_age_get_entry_weight (RBRandomPlayOrder *rorder,
  31                                                  RhythmDB *db, RhythmDBEntry *entry);
  32
  33 G_DEFINE_TYPE (RBRandomPlayOrderByAge, rb_random_play_order_by_age, RB_TYPE_RANDOM_PLAY_ORDER)
  34
  35 static void
  36 rb_random_play_order_by_age_class_init (RBRandomPlayOrderByAgeClass *klass)
  37 {
  38         RBRandomPlayOrderClass *rorder;
  39
  40         rorder = RB_RANDOM_PLAY_ORDER_CLASS (klass);
  41         rorder->get_entry_weight = rb_random_by_age_get_entry_weight;
  42 }
  43
  44 RBPlayOrder *
  45 rb_random_play_order_by_age_new (RBShellPlayer *player)
  46 {
  47         RBRandomPlayOrderByAge *rorder;
  48
  49         rorder = g_object_new (RB_TYPE_RANDOM_PLAY_ORDER_BY_AGE,
  50                         "player", player,
  51                         NULL);
  52
  53         return RB_PLAY_ORDER (rorder);
  54 }
  55
  56 static void
  57 rb_random_play_order_by_age_init (RBRandomPlayOrderByAge *porder)
  58 {
  59 }
  60
  61 static double
  62 rb_random_by_age_get_entry_weight (RBRandomPlayOrder *rorder, RhythmDB *db, RhythmDBEntry *entry)
  63 {
  64         time_t now;
  65         gulong last_play;
  66         gulong seconds_since_last_play;
  67
  68         /* This returns the log of the number of seconds since the last play.
  69          * It handles never played automatically, since now-0 is a valid
  70          * argument to log(). */
  71
  72         time (&now);
  73         last_play = rhythmdb_entry_get_ulong (entry, RHYTHMDB_PROP_LAST_PLAYED);
  74         seconds_since_last_play = now - last_play;
  75         /* The lowest weight should be 0. */
  76         if (seconds_since_last_play < 1)
  77                 seconds_since_last_play = 1;
  78         return log (seconds_since_last_play);
  79 }