git.sesse.net Git - vlc/blob - src/misc/block.c

   1 /*****************************************************************************
   2  * block.c: Data blocks management functions
   3  *****************************************************************************
   4  * Copyright (C) 2003-2004 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Laurent Aimar <fenrir@videolan.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27 #include <stdlib.h>
  28
  29 #include <vlc/vlc.h>
  30 #include "vlc_block.h"
  31
  32 /*****************************************************************************
  33  * Block functions.
  34  *****************************************************************************/
  35 /* private */
  36 struct block_sys_t
  37 {
  38     uint8_t     *p_allocated_buffer;
  39     int         i_allocated_buffer;
  40 };
  41
  42 #define BLOCK_PADDING_SIZE 32
  43 static void BlockRelease( block_t * );
  44
  45 block_t *__block_New( vlc_object_t *p_obj, int i_size )
  46 {
  47     /* We do only one malloc
  48      * TODO bench if doing 2 malloc but keeping a pool of buffer is better
  49      * 16 -> align on 16
  50      * 2 * BLOCK_PADDING_SIZE -> pre + post padding
  51      */
  52     block_sys_t *p_sys;
  53     const int i_alloc = i_size + 2 * BLOCK_PADDING_SIZE + 16;
  54     block_t *p_block =
  55         malloc( sizeof( block_t ) + sizeof( block_sys_t ) + i_alloc );
  56
  57     if( p_block == NULL ) return NULL;
  58
  59     /* Fill opaque data */
  60     p_sys = (block_sys_t*)( (uint8_t*)p_block + sizeof( block_t ) );
  61     p_sys->i_allocated_buffer = i_alloc;
  62     p_sys->p_allocated_buffer = (uint8_t*)p_block + sizeof( block_t ) +
  63         sizeof( block_sys_t );
  64
  65     /* Fill all fields */
  66     p_block->p_next         = NULL;
  67     p_block->p_prev         = NULL;
  68     p_block->i_flags        = 0;
  69     p_block->i_pts          = 0;
  70     p_block->i_dts          = 0;
  71     p_block->i_length       = 0;
  72     p_block->i_rate         = 0;
  73     p_block->i_seqno        = 0;
  74     p_block->i_buffer       = i_size;
  75     p_block->p_buffer       =
  76         &p_sys->p_allocated_buffer[BLOCK_PADDING_SIZE +
  77             16 - ((uintptr_t)p_sys->p_allocated_buffer % 16 )];
  78     p_block->pf_release     = BlockRelease;
  79
  80     /* Is ok, as no comunication between p_vlc */
  81     p_block->p_manager      = VLC_OBJECT( p_obj->p_vlc );
  82     p_block->p_sys          = p_sys;
  83
  84     return p_block;
  85 }
  86
  87 block_t *block_Realloc( block_t *p_block, int i_prebody, int i_body )
  88 {
  89     int i_buffer_size;
  90
  91     if( p_block->pf_release != BlockRelease )
  92     {
  93         /* Special case when pf_release if overloaded
  94          * TODO if used one day, them implement it in a smarter way */
  95         block_t *p_dup = block_Duplicate( p_block );
  96         block_Release( p_block );
  97
  98         p_block = p_dup;
  99     }
 100
 101     i_buffer_size = i_prebody + i_body;
 102
 103     if( i_body < 0 || i_buffer_size <= 0 ) return NULL;
 104
 105     if( p_block->p_buffer - i_prebody > p_block->p_sys->p_allocated_buffer &&
 106         p_block->p_buffer - i_prebody < p_block->p_sys->p_allocated_buffer +
 107         p_block->p_sys->i_allocated_buffer )
 108     {
 109         p_block->p_buffer -= i_prebody;
 110         p_block->i_buffer += i_prebody;
 111         i_prebody = 0;
 112     }
 113     if( p_block->p_buffer + i_body < p_block->p_sys->p_allocated_buffer +
 114         p_block->p_sys->i_allocated_buffer )
 115     {
 116         p_block->i_buffer = i_buffer_size;
 117         i_body = 0;
 118     }
 119
 120     if( i_body > 0 || i_prebody > 0 )
 121     {
 122         block_t *p_rea = block_New( p_block->p_manager, i_buffer_size );
 123
 124         p_rea->i_dts     = p_block->i_dts;
 125         p_rea->i_pts     = p_block->i_pts;
 126         p_rea->i_flags   = p_block->i_flags;
 127         p_rea->i_length  = p_block->i_length;
 128         p_rea->i_rate    = p_block->i_rate;
 129         p_rea->i_samples = p_block->i_samples;
 130
 131         memcpy( p_rea->p_buffer + i_prebody, p_block->p_buffer,
 132                 __MIN( p_block->i_buffer, p_rea->i_buffer - i_prebody ) );
 133
 134         block_Release( p_block );
 135
 136         return p_rea;
 137     }
 138
 139     return p_block;
 140 }
 141
 142 static void BlockRelease( block_t *p_block )
 143 {
 144     free( p_block );
 145 }
 146
 147
 148 /*****************************************************************************
 149  * block_fifo_t management
 150  *****************************************************************************/
 151 block_fifo_t *__block_FifoNew( vlc_object_t *p_obj )
 152 {
 153     block_fifo_t *p_fifo;
 154
 155     p_fifo = malloc( sizeof( vlc_object_t ) );
 156     vlc_mutex_init( p_obj, &p_fifo->lock );
 157     vlc_cond_init( p_obj, &p_fifo->wait );
 158     p_fifo->i_depth = p_fifo->i_size = 0;
 159     p_fifo->p_first = NULL;
 160     p_fifo->pp_last = &p_fifo->p_first;
 161
 162     return p_fifo;
 163 }
 164
 165 void block_FifoRelease( block_fifo_t *p_fifo )
 166 {
 167     block_FifoEmpty( p_fifo );
 168     vlc_cond_destroy( &p_fifo->wait );
 169     vlc_mutex_destroy( &p_fifo->lock );
 170     free( p_fifo );
 171 }
 172
 173 void block_FifoEmpty( block_fifo_t *p_fifo )
 174 {
 175     block_t *b;
 176
 177     vlc_mutex_lock( &p_fifo->lock );
 178     for( b = p_fifo->p_first; b != NULL; )
 179     {
 180         block_t *p_next;
 181
 182         p_next = b->p_next;
 183         block_Release( b );
 184         b = p_next;
 185     }
 186
 187     p_fifo->i_depth = p_fifo->i_size = 0;
 188     p_fifo->p_first = NULL;
 189     p_fifo->pp_last = &p_fifo->p_first;
 190     vlc_mutex_unlock( &p_fifo->lock );
 191 }
 192
 193 int block_FifoPut( block_fifo_t *p_fifo, block_t *p_block )
 194 {
 195     int i_size = 0;
 196     vlc_mutex_lock( &p_fifo->lock );
 197
 198     do
 199     {
 200         i_size += p_block->i_buffer;
 201
 202         *p_fifo->pp_last = p_block;
 203         p_fifo->pp_last = &p_block->p_next;
 204         p_fifo->i_depth++;
 205         p_fifo->i_size += p_block->i_buffer;
 206
 207         p_block = p_block->p_next;
 208
 209     } while( p_block );
 210
 211     /* warn there is data in this fifo */
 212     vlc_cond_signal( &p_fifo->wait );
 213     vlc_mutex_unlock( &p_fifo->lock );
 214
 215     return i_size;
 216 }
 217
 218 block_t *block_FifoGet( block_fifo_t *p_fifo )
 219 {
 220     block_t *b;
 221
 222     vlc_mutex_lock( &p_fifo->lock );
 223
 224     /* We do a while here because there is a race condition in the
 225      * win32 implementation of vlc_cond_wait() (We can't be sure the fifo
 226      * hasn't been emptied again since we were signaled). */
 227     while( p_fifo->p_first == NULL )
 228     {
 229         vlc_cond_wait( &p_fifo->wait, &p_fifo->lock );
 230     }
 231
 232     b = p_fifo->p_first;
 233
 234     p_fifo->p_first = b->p_next;
 235     p_fifo->i_depth--;
 236     p_fifo->i_size -= b->i_buffer;
 237
 238     if( p_fifo->p_first == NULL )
 239     {
 240         p_fifo->pp_last = &p_fifo->p_first;
 241     }
 242
 243     vlc_mutex_unlock( &p_fifo->lock );
 244
 245     b->p_next = NULL;
 246     return b;
 247 }
 248
 249 block_t *block_FifoShow( block_fifo_t *p_fifo )
 250 {
 251     block_t *b;
 252
 253     vlc_mutex_lock( &p_fifo->lock );
 254
 255     if( p_fifo->p_first == NULL )
 256     {
 257         vlc_cond_wait( &p_fifo->wait, &p_fifo->lock );
 258     }
 259
 260     b = p_fifo->p_first;
 261
 262     vlc_mutex_unlock( &p_fifo->lock );
 263
 264     return( b );
 265
 266 }
 267