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

   1 /*****************************************************************************
   2  * block.c: Data blocks management functions
   3  *****************************************************************************
   4  * Copyright (C) 2003-2004 VideoLAN
   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 #include <stdarg.h>
  29
  30 #include <vlc/vlc.h>
  31 #include "vlc_block.h"
  32
  33 /* private */
  34 struct block_sys_t
  35 {
  36     vlc_mutex_t lock;
  37
  38     uint8_t     *p_allocated_buffer;
  39     int         i_allocated_buffer;
  40
  41     vlc_bool_t  b_modify;       /* has it been put in modified state */
  42     int         i_duplicated;   /* how many times has the content been
  43                                  * duplicated */
  44
  45 };
  46
  47 static void BlockRelease( block_t *p_block )
  48 {
  49     vlc_mutex_lock( &p_block->p_sys->lock );
  50
  51     p_block->p_sys->i_duplicated--;
  52     if( p_block->p_sys->i_duplicated < 0 )
  53     {
  54         vlc_mutex_unlock( &p_block->p_sys->lock );
  55         vlc_mutex_destroy( &p_block->p_sys->lock );
  56         free( p_block->p_sys->p_allocated_buffer );
  57         free( p_block->p_sys );
  58         free( p_block );
  59
  60         return;
  61     }
  62
  63     vlc_mutex_unlock( &p_block->p_sys->lock );
  64     free( p_block );
  65 }
  66
  67 static block_t *__BlockDupContent( block_t *p_block )
  68 {
  69     block_t *p_dup;
  70
  71     p_dup = block_New( p_block->p_manager, p_block->i_buffer );
  72     memcpy( p_dup->p_buffer, p_block->p_buffer, p_block->i_buffer );
  73     p_dup->i_flags         = p_block->i_flags;
  74     p_dup->i_pts           = p_block->i_pts;
  75     p_dup->i_dts           = p_block->i_dts;
  76     p_dup->i_length        = p_block->i_length;
  77     p_dup->i_rate          = p_block->i_rate;
  78
  79     return p_dup;
  80 }
  81
  82 static block_t *BlockModify( block_t *p_block, vlc_bool_t b_will_modify )
  83 {
  84     block_t *p_mod = p_block;   /* by default */
  85
  86     vlc_mutex_lock( &p_block->p_sys->lock );
  87
  88     if( p_block->p_sys->b_modify == b_will_modify )
  89     {
  90         vlc_mutex_unlock( &p_block->p_sys->lock );
  91         return p_block;
  92     }
  93
  94     if( p_block->p_sys->i_duplicated == 0 )
  95     {
  96         p_block->p_sys->b_modify = b_will_modify;
  97         vlc_mutex_unlock( &p_block->p_sys->lock );
  98         return p_block;
  99     }
 100
 101     /* FIXME we could avoid that
 102      * we just need to create a new p_sys with new mem FIXME */
 103     p_mod = __BlockDupContent( p_block );
 104     vlc_mutex_unlock( &p_block->p_sys->lock );
 105
 106     BlockRelease( p_block );
 107
 108     return p_mod;
 109 }
 110
 111 static block_t *BlockDuplicate( block_t *p_block )
 112 {
 113     block_t *p_dup;
 114
 115     vlc_mutex_lock( &p_block->p_sys->lock );
 116     if( !p_block->p_sys->b_modify )
 117     {
 118         p_block->p_sys->i_duplicated++;
 119         vlc_mutex_unlock( &p_block->p_sys->lock );
 120         p_dup = block_NewEmpty();
 121         memcpy( p_dup, p_block, sizeof( block_t ) );
 122         p_dup->p_next = NULL;
 123         return p_dup;
 124     }
 125     p_dup = __BlockDupContent( p_block );
 126     vlc_mutex_unlock( &p_block->p_sys->lock );
 127
 128     return p_dup;
 129 }
 130
 131 static block_t *BlockRealloc( block_t *p_block, int i_prebody, int i_body )
 132 {
 133     int i_buffer_size = i_prebody + i_body;
 134
 135     if( i_body < 0 || i_buffer_size <= 0 ) return NULL;
 136
 137     vlc_mutex_lock( &p_block->p_sys->lock );
 138
 139     if( i_prebody < ( p_block->p_buffer - p_block->p_sys->p_allocated_buffer +
 140                       p_block->p_sys->i_allocated_buffer ) ||
 141         p_block->p_buffer - i_prebody > p_block->p_sys->p_allocated_buffer )
 142     {
 143         p_block->p_buffer -= i_prebody;
 144         p_block->i_buffer += i_prebody;
 145         i_prebody = 0;
 146     }
 147     if( p_block->p_buffer + i_body < p_block->p_sys->p_allocated_buffer +
 148         p_block->p_sys->i_allocated_buffer )
 149     {
 150         p_block->i_buffer = i_buffer_size;
 151         i_body = 0;
 152     }
 153
 154     if( i_body > 0 || i_prebody > 0 )
 155     {
 156         block_t *p_rea = block_New( p_block->p_manager, i_buffer_size );
 157
 158         p_rea->i_dts   = p_block->i_dts;
 159         p_rea->i_pts   = p_block->i_pts;
 160         p_rea->i_flags = p_block->i_flags;
 161         p_rea->i_length= p_block->i_length;
 162         p_rea->i_rate  = p_block->i_rate;
 163
 164         memcpy( p_rea->p_buffer + i_prebody, p_block->p_buffer,
 165                 __MIN( p_block->i_buffer, p_rea->i_buffer - i_prebody ) );
 166
 167         vlc_mutex_unlock( &p_block->p_sys->lock );
 168         block_Release( p_block );
 169
 170         return p_rea;
 171     }
 172
 173     vlc_mutex_unlock( &p_block->p_sys->lock );
 174
 175     return p_block;
 176 }
 177
 178 /*****************************************************************************
 179  * Standard block management
 180  *
 181  *****************************************************************************/
 182 /* to be used by other block management */
 183 block_t *block_NewEmpty( void )
 184 {
 185     block_t *p_block;
 186
 187     p_block = malloc( sizeof( block_t ) );
 188     memset( p_block, 0, sizeof( block_t ) );
 189
 190     p_block->p_next         = NULL;
 191     p_block->i_flags        = 0;
 192     p_block->i_pts          = 0;
 193     p_block->i_dts          = 0;
 194     p_block->i_length       = 0;
 195     p_block->i_rate         = 0;
 196
 197     p_block->i_buffer       = 0;
 198     p_block->p_buffer       = NULL;
 199
 200     p_block->pf_release     = NULL;
 201     p_block->pf_duplicate   = NULL;
 202     p_block->pf_modify      = NULL;
 203     p_block->pf_realloc     = NULL;
 204
 205     p_block->p_manager      = NULL;
 206     p_block->p_sys = NULL;
 207     return p_block;
 208 }
 209
 210 block_t *__block_New( vlc_object_t *p_obj, int i_size )
 211 {
 212     block_t     *p_block;
 213     block_sys_t *p_sys;
 214
 215     p_block = block_NewEmpty();
 216
 217     p_block->pf_release     = BlockRelease;
 218     p_block->pf_duplicate   = BlockDuplicate;
 219     p_block->pf_modify      = BlockModify;
 220     p_block->pf_realloc     = BlockRealloc;
 221
 222     /* that should be ok (no comunication between multiple p_vlc) */
 223     p_block->p_manager      = VLC_OBJECT( p_obj->p_vlc );
 224
 225     p_block->p_sys = p_sys = malloc( sizeof( block_sys_t ) );
 226     vlc_mutex_init( p_obj, &p_sys->lock );
 227
 228     /* XXX align on 16 and add 32 prebuffer/posbuffer bytes */
 229     p_sys->i_allocated_buffer = i_size + 32 + 32 + 16;
 230     p_sys->p_allocated_buffer = malloc( p_sys->i_allocated_buffer );
 231     p_block->i_buffer         = i_size;
 232     p_block->p_buffer         = &p_sys->p_allocated_buffer[32+15-((long)p_sys->p_allocated_buffer % 16 )];
 233
 234     p_sys->i_duplicated = 0;
 235     p_sys->b_modify = VLC_TRUE;
 236
 237     return p_block;
 238 }
 239
 240 void block_ChainAppend( block_t **pp_list, block_t *p_block )
 241 {
 242     if( *pp_list == NULL )
 243     {
 244         *pp_list = p_block;
 245     }
 246     else
 247     {
 248         block_t *p = *pp_list;
 249
 250         while( p->p_next )
 251         {
 252             p = p->p_next;
 253         }
 254         p->p_next = p_block;
 255     }
 256 }
 257
 258 void block_ChainLastAppend( block_t ***ppp_last, block_t *p_block  )
 259 {
 260     block_t *p_last = p_block;
 261
 262     /* Append the block */
 263     **ppp_last = p_block;
 264
 265     /* Update last pointer */
 266     while( p_last->p_next ) p_last = p_last->p_next;
 267     *ppp_last = &p_last->p_next;
 268 }
 269
 270 void block_ChainRelease( block_t *p_block )
 271 {
 272     while( p_block )
 273     {
 274         block_t *p_next;
 275         p_next = p_block->p_next;
 276         p_block->pf_release( p_block );
 277         p_block = p_next;
 278     }
 279 }
 280
 281 int block_ChainExtract( block_t *p_list, void *p_data, int i_max )
 282 {
 283     block_t *b;
 284     int     i_total = 0;
 285     uint8_t *p = p_data;
 286
 287     for( b = p_list; b != NULL; b = b->p_next )
 288     {
 289         int i_copy;
 290
 291         i_copy = __MIN( i_max, b->i_buffer );
 292         if( i_copy > 0 )
 293         {
 294             memcpy( p, b->p_buffer, i_copy );
 295             i_max   -= i_copy;
 296             i_total += i_copy;
 297             p       += i_copy;
 298
 299             if( i_max == 0 )
 300             {
 301                 return i_total;
 302             }
 303         }
 304     }
 305     return i_total;
 306 }
 307
 308 block_t *block_ChainGather( block_t *p_list )
 309 {
 310     int     i_total = 0;
 311     block_t *b, *g;
 312
 313     if( p_list->p_next == NULL )
 314     {
 315         /* only one, so no need */
 316         return p_list;
 317     }
 318
 319     for( b = p_list; b != NULL; b = b->p_next )
 320     {
 321         i_total += b->i_buffer;
 322     }
 323
 324     g = block_New( p_list->p_manager, i_total );
 325     block_ChainExtract( p_list, g->p_buffer, g->i_buffer );
 326
 327     g->i_flags = p_list->i_flags;
 328     g->i_pts   = p_list->i_pts;
 329     g->i_dts   = p_list->i_dts;
 330
 331     /* free p_list */
 332     block_ChainRelease( p_list );
 333     return g;
 334 }
 335
 336 /*****************************************************************************
 337  * block_fifo_t management
 338  *****************************************************************************/
 339 block_fifo_t *__block_FifoNew( vlc_object_t *p_obj )
 340 {
 341     block_fifo_t *p_fifo;
 342
 343     p_fifo = malloc( sizeof( vlc_object_t ) );
 344     vlc_mutex_init( p_obj, &p_fifo->lock );
 345     vlc_cond_init( p_obj, &p_fifo->wait );
 346     p_fifo->i_depth = 0;
 347     p_fifo->p_first = NULL;
 348     p_fifo->pp_last = &p_fifo->p_first;
 349
 350     return p_fifo;
 351 }
 352
 353 void block_FifoRelease( block_fifo_t *p_fifo )
 354 {
 355     block_FifoEmpty( p_fifo );
 356     vlc_cond_destroy( &p_fifo->wait );
 357     vlc_mutex_destroy( &p_fifo->lock );
 358     free( p_fifo );
 359 }
 360
 361 void block_FifoEmpty( block_fifo_t *p_fifo )
 362 {
 363     block_t *b;
 364
 365     vlc_mutex_lock( &p_fifo->lock );
 366     for( b = p_fifo->p_first; b != NULL; )
 367     {
 368         block_t *p_next;
 369
 370         p_next = b->p_next;
 371         block_Release( b );
 372         b = p_next;
 373     }
 374
 375     p_fifo->i_depth = 0;
 376     p_fifo->p_first = NULL;
 377     p_fifo->pp_last = &p_fifo->p_first;
 378     vlc_mutex_unlock( &p_fifo->lock );
 379 }
 380
 381 int block_FifoPut( block_fifo_t *p_fifo, block_t *p_block )
 382 {
 383     int i_size = 0;
 384     vlc_mutex_lock( &p_fifo->lock );
 385
 386     do
 387     {
 388         i_size += p_block->i_buffer;
 389
 390         *p_fifo->pp_last = p_block;
 391         p_fifo->pp_last = &p_block->p_next;
 392         p_fifo->i_depth++;
 393
 394         p_block = p_block->p_next;
 395
 396     } while( p_block );
 397
 398     /* warn there is data in this fifo */
 399     vlc_cond_signal( &p_fifo->wait );
 400     vlc_mutex_unlock( &p_fifo->lock );
 401
 402     return i_size;
 403 }
 404
 405 block_t *block_FifoGet( block_fifo_t *p_fifo )
 406 {
 407     block_t *b;
 408
 409     vlc_mutex_lock( &p_fifo->lock );
 410
 411     /* We do a while here because there is a race condition in the
 412      * win32 implementation of vlc_cond_wait() (We can't be sure the fifo
 413      * hasn't been emptied again since we were signaled). */
 414     while( p_fifo->p_first == NULL )
 415     {
 416         vlc_cond_wait( &p_fifo->wait, &p_fifo->lock );
 417     }
 418
 419     b = p_fifo->p_first;
 420
 421     p_fifo->p_first = b->p_next;
 422     p_fifo->i_depth--;
 423
 424     if( p_fifo->p_first == NULL )
 425     {
 426         p_fifo->pp_last = &p_fifo->p_first;
 427     }
 428
 429     vlc_mutex_unlock( &p_fifo->lock );
 430
 431     b->p_next = NULL;
 432     return( b );
 433 }
 434
 435 block_t *block_FifoShow( block_fifo_t *p_fifo )
 436 {
 437     block_t *b;
 438
 439     vlc_mutex_lock( &p_fifo->lock );
 440
 441     if( p_fifo->p_first == NULL )
 442     {
 443         vlc_cond_wait( &p_fifo->wait, &p_fifo->lock );
 444     }
 445
 446     b = p_fifo->p_first;
 447
 448     vlc_mutex_unlock( &p_fifo->lock );
 449
 450     return( b );
 451
 452 }
 453