src/timer.c

   1 /* the Music Player Daemon (MPD)
   2  * Copyright (C) 2007 by Warren Dukes (warren.dukes@gmail.com)
   3  * This project's homepage is: http://www.musicpd.org
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  17  */
  18
  19 #include "timer.h"
  20 #include "utils.h"
  21
  22 #include <assert.h>
  23 #include <limits.h>
  24 #include <sys/time.h>
  25
  26 static uint64_t now(void)
  27 {
  28         struct timeval tv;
  29
  30         gettimeofday(&tv, NULL);
  31
  32         return ((uint64_t)tv.tv_sec * 1000000) + tv.tv_usec;
  33 }
  34
  35 Timer *timer_new(AudioFormat *af)
  36 {
  37         Timer *timer;
  38
  39         timer = xmalloc(sizeof(Timer));
  40         timer->time = 0;
  41         timer->started = 0;
  42         timer->rate = af->sampleRate * (af->bits / CHAR_BIT) * af->channels;
  43
  44         return timer;
  45 }
  46
  47 void timer_free(Timer *timer)
  48 {
  49         free(timer);
  50 }
  51
  52 void timer_start(Timer *timer)
  53 {
  54         timer->time = now();
  55         timer->started = 1;
  56 }
  57
  58 void timer_reset(Timer *timer)
  59 {
  60         timer->time = 0;
  61         timer->started = 0;
  62 }
  63
  64 void timer_add(Timer *timer, int size)
  65 {
  66         assert(timer->started);
  67
  68         timer->time += ((uint64_t)size * 1000000) / timer->rate;
  69 }
  70
  71 void timer_sync(Timer *timer)
  72 {
  73         int64_t sleep;
  74
  75         assert(timer->started);
  76
  77         sleep = timer->time - now();
  78         if (sleep > 0)
  79                 my_usleep(sleep);
  80 }