src/misc/picture_fifo.c

   1 /*****************************************************************************
   2  * picture_fifo.c : picture fifo functions
   3  *****************************************************************************
   4  * Copyright (C) 2009 VLC authors and VideoLAN
   5  * Copyright (C) 2009 Laurent Aimar <fenrir _AT_ videolan _DOT_ org>
   6  * $Id$
   7  *
   8  * Authors: Laurent Aimar <fenrir _AT_ videolan _DOT_ org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU Lesser General Public License as published by
  12  * the Free Software Foundation; either version 2.1 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public License
  21  * along with this program; if not, write to the Free Software Foundation,
  22  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 /*****************************************************************************
  26  * Preamble
  27  *****************************************************************************/
  28
  29 #ifdef HAVE_CONFIG_H
  30 # include "config.h"
  31 #endif
  32 #include <assert.h>
  33
  34 #include <vlc_common.h>
  35 #include <vlc_picture_fifo.h>
  36
  37 /*****************************************************************************
  38  *
  39  *****************************************************************************/
  40 struct picture_fifo_t {
  41     vlc_mutex_t lock;
  42     picture_t   *first;
  43     picture_t   **last_ptr;
  44 };
  45
  46 static void PictureFifoReset(picture_fifo_t *fifo)
  47 {
  48     fifo->first    = NULL;
  49     fifo->last_ptr = &fifo->first;
  50 }
  51 static void PictureFifoPush(picture_fifo_t *fifo, picture_t *picture)
  52 {
  53     assert(!picture->p_next);
  54     *fifo->last_ptr = picture;
  55     fifo->last_ptr  = &picture->p_next;
  56 }
  57 static picture_t *PictureFifoPop(picture_fifo_t *fifo)
  58 {
  59     picture_t *picture = fifo->first;
  60
  61     if (picture) {
  62         fifo->first = picture->p_next;
  63         if (!fifo->first)
  64             fifo->last_ptr = &fifo->first;
  65         picture->p_next = NULL;
  66     }
  67     return picture;
  68 }
  69
  70 picture_fifo_t *picture_fifo_New(void)
  71 {
  72     picture_fifo_t *fifo = malloc(sizeof(*fifo));
  73     if (!fifo)
  74         return NULL;
  75
  76     vlc_mutex_init(&fifo->lock);
  77     PictureFifoReset(fifo);
  78     return fifo;
  79 }
  80
  81 void picture_fifo_Push(picture_fifo_t *fifo, picture_t *picture)
  82 {
  83     vlc_mutex_lock(&fifo->lock);
  84     PictureFifoPush(fifo, picture);
  85     vlc_mutex_unlock(&fifo->lock);
  86 }
  87 picture_t *picture_fifo_Pop(picture_fifo_t *fifo)
  88 {
  89     vlc_mutex_lock(&fifo->lock);
  90     picture_t *picture = PictureFifoPop(fifo);
  91     vlc_mutex_unlock(&fifo->lock);
  92
  93     return picture;
  94 }
  95 picture_t *picture_fifo_Peek(picture_fifo_t *fifo)
  96 {
  97     vlc_mutex_lock(&fifo->lock);
  98     picture_t *picture = fifo->first;
  99     if (picture)
 100         picture_Hold(picture);
 101     vlc_mutex_unlock(&fifo->lock);
 102
 103     return picture;
 104 }
 105 void picture_fifo_Flush(picture_fifo_t *fifo, mtime_t date, bool flush_before)
 106 {
 107     picture_t *picture;
 108
 109     vlc_mutex_lock(&fifo->lock);
 110
 111     picture = fifo->first;
 112     PictureFifoReset(fifo);
 113
 114     picture_fifo_t tmp;
 115     PictureFifoReset(&tmp);
 116
 117     while (picture) {
 118         picture_t *next = picture->p_next;
 119
 120         picture->p_next = NULL;
 121         if (( flush_before && picture->date <= date) ||
 122             (!flush_before && picture->date >= date))
 123             PictureFifoPush(&tmp, picture);
 124         else
 125             PictureFifoPush(fifo, picture);
 126         picture = next;
 127     }
 128     vlc_mutex_unlock(&fifo->lock);
 129
 130     while ((picture = PictureFifoPop(&tmp)) != NULL)
 131         picture_Release(picture);
 132 }
 133 void picture_fifo_OffsetDate(picture_fifo_t *fifo, mtime_t delta)
 134 {
 135     vlc_mutex_lock(&fifo->lock);
 136     for (picture_t *picture = fifo->first; picture != NULL;) {
 137         picture->date += delta;
 138         picture = picture->p_next;
 139     }
 140     vlc_mutex_unlock(&fifo->lock);
 141 }
 142 void picture_fifo_Delete(picture_fifo_t *fifo)
 143 {
 144     picture_fifo_Flush(fifo, INT64_MAX, true);
 145     vlc_mutex_destroy(&fifo->lock);
 146     free(fifo);
 147 }
 148