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: block.c,v 1.7 2004/02/25 17:48:52 fenrir Exp $
   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
  77     return p_dup;
  78 }
  79
  80 static block_t *BlockModify( block_t *p_block, vlc_bool_t b_will_modify )
  81 {
  82     block_t *p_mod = p_block;   /* by default */
  83
  84     vlc_mutex_lock( &p_block->p_sys->lock );
  85
  86     if( p_block->p_sys->b_modify == b_will_modify )
  87     {
  88         vlc_mutex_unlock( &p_block->p_sys->lock );
  89         return p_block;
  90     }
  91
  92     if( p_block->p_sys->i_duplicated == 0 )
  93     {
  94         p_block->p_sys->b_modify = b_will_modify;
  95         vlc_mutex_unlock( &p_block->p_sys->lock );
  96         return p_block;
  97     }
  98
  99     /* FIXME we could avoid that
 100      * we just need to create a new p_sys with new mem FIXME */
 101     p_mod = __BlockDupContent( p_block );
 102     vlc_mutex_unlock( &p_block->p_sys->lock );
 103
 104     BlockRelease( p_block );
 105
 106     return p_mod;
 107 }
 108
 109 static block_t *BlockDuplicate( block_t *p_block )
 110 {
 111     block_t *p_dup;
 112
 113     vlc_mutex_lock( &p_block->p_sys->lock );
 114     if( !p_block->p_sys->b_modify )
 115     {
 116         p_block->p_sys->i_duplicated++;
 117         vlc_mutex_unlock( &p_block->p_sys->lock );
 118         p_dup = block_NewEmpty();
 119         memcpy( p_dup, p_block, sizeof( block_t ) );
 120         p_dup->p_next = NULL;
 121         return p_dup;
 122     }
 123     p_dup = __BlockDupContent( p_block );
 124     vlc_mutex_unlock( &p_block->p_sys->lock );
 125
 126     return p_dup;
 127 }
 128
 129 static block_t *BlockRealloc( block_t *p_block, int i_prebody, int i_body )
 130 {
 131
 132     vlc_mutex_lock( &p_block->p_sys->lock );
 133     if( i_prebody < 0 || p_block->p_buffer - i_prebody >
 134         p_block->p_sys->p_allocated_buffer )
 135     {
 136         p_block->p_buffer -= i_prebody;
 137         p_block->i_buffer += i_prebody;
 138         i_prebody = 0;
 139     }
 140     if( i_body < 0 ||
 141         p_block->p_buffer + i_body < p_block->p_sys->p_allocated_buffer +
 142         p_block->p_sys->i_allocated_buffer )
 143     {
 144         p_block->i_buffer = i_body;
 145         i_body = 0;
 146     }
 147     vlc_mutex_unlock( &p_block->p_sys->lock );
 148
 149     if( i_prebody > 0 )
 150     {
 151         block_t *p_rea = block_New( p_block->p_manager, i_prebody + i_body );
 152
 153         memcpy( &p_rea->p_buffer[i_prebody], p_block->p_buffer,
 154                 p_block->i_buffer );
 155
 156         return p_rea;
 157     }
 158
 159     if( i_body > 0 )
 160     {
 161         int i_start;
 162         block_t *p_rea = BlockModify( p_block, VLC_TRUE );
 163
 164         i_start = p_rea->p_buffer - p_rea->p_sys->p_allocated_buffer;
 165
 166         p_rea->p_sys->i_allocated_buffer += i_body - p_rea->i_buffer;
 167         p_rea->p_sys->p_allocated_buffer =
 168             realloc( p_rea->p_sys->p_allocated_buffer,
 169                      p_rea->p_sys->i_allocated_buffer );
 170
 171         p_rea->p_buffer = &p_rea->p_sys->p_allocated_buffer[i_start];
 172         p_rea->i_buffer = i_body;
 173
 174         return p_rea;
 175     }
 176
 177     return p_block;
 178 }
 179
 180 /*****************************************************************************
 181  * Standard block management
 182  *
 183  *****************************************************************************/
 184 /* to be used by other block management */
 185 block_t *block_NewEmpty( void )
 186 {
 187     block_t *p_block;
 188
 189     p_block = malloc( sizeof( block_t ) );
 190     memset( p_block, 0, sizeof( block_t ) );
 191
 192     p_block->p_next         = NULL;
 193     p_block->i_flags        = 0;
 194     p_block->i_pts          = 0;
 195     p_block->i_dts          = 0;
 196     p_block->i_length       = 0;
 197
 198     p_block->i_buffer       = 0;
 199     p_block->p_buffer       = NULL;
 200
 201     p_block->pf_release     = NULL;
 202     p_block->pf_duplicate   = NULL;
 203     p_block->pf_modify      = NULL;
 204     p_block->pf_realloc     = NULL;
 205
 206     p_block->p_manager      = NULL;
 207     p_block->p_sys = NULL;
 208     return p_block;
 209 }
 210
 211 block_t *__block_New( vlc_object_t *p_obj, int i_size )
 212 {
 213     block_t     *p_block;
 214     block_sys_t *p_sys;
 215
 216     p_block = block_NewEmpty();
 217
 218     p_block->i_buffer       = i_size;
 219     if( i_size > 0 )
 220     {
 221         p_block->p_buffer   = malloc( i_size );
 222     }
 223
 224     p_block->pf_release     = BlockRelease;
 225     p_block->pf_duplicate   = BlockDuplicate;
 226     p_block->pf_modify      = BlockModify;
 227     p_block->pf_realloc     = BlockRealloc;
 228
 229     /* that should be ok (no comunication between multiple p_vlc) */
 230     p_block->p_manager      = VLC_OBJECT( p_obj->p_vlc );
 231
 232     p_block->p_sys = p_sys = malloc( sizeof( block_sys_t ) );
 233     vlc_mutex_init( p_obj, &p_sys->lock );
 234     p_sys->p_allocated_buffer = p_block->p_buffer;
 235     p_sys->i_allocated_buffer = p_block->i_buffer;
 236     p_sys->i_duplicated = 0;
 237     p_sys->b_modify = VLC_TRUE;
 238
 239     return p_block;
 240 }
 241
 242 void block_ChainAppend( block_t **pp_list, block_t *p_block )
 243 {
 244
 245     if( *pp_list == NULL )
 246     {
 247         *pp_list = p_block;
 248     }
 249     else
 250     {
 251         block_t *p = *pp_list;
 252
 253         while( p->p_next )
 254         {
 255             p = p->p_next;
 256         }
 257         p->p_next = p_block;
 258     }
 259 }
 260
 261 void block_ChainRelease( block_t *p_block )
 262 {
 263     while( p_block )
 264     {
 265         block_t *p_next;
 266         p_next = p_block->p_next;
 267         p_block->pf_release( p_block );
 268         p_block = p_next;
 269     }
 270 }
 271
 272 int block_ChainExtract( block_t *p_list, void *p_data, int i_max )
 273 {
 274     block_t *b;
 275     int     i_total = 0;
 276     uint8_t *p = p_data;
 277
 278     for( b = p_list; b != NULL; b = b->p_next )
 279     {
 280         int i_copy;
 281
 282         i_copy = __MIN( i_max, b->i_buffer );
 283         if( i_copy > 0 )
 284         {
 285             memcpy( p, b->p_buffer, i_copy );
 286             i_max   -= i_copy;
 287             i_total += i_copy;
 288             p       += i_copy;
 289
 290             if( i_max == 0 )
 291             {
 292                 return i_total;
 293             }
 294         }
 295     }
 296     return i_total;
 297 }
 298
 299 block_t *block_ChainGather( block_t *p_list )
 300 {
 301     int     i_total = 0;
 302     block_t *b, *g;
 303
 304     if( p_list->p_next == NULL )
 305     {
 306         /* only one, so no need */
 307         return p_list;
 308     }
 309
 310     for( b = p_list; b != NULL; b = b->p_next )
 311     {
 312         i_total += b->i_buffer;
 313     }
 314
 315     g = block_New( p_list->p_manager, i_total );
 316     block_ChainExtract( p_list, g->p_buffer, g->i_buffer );
 317
 318     g->i_flags = p_list->i_flags;
 319     g->i_pts   = p_list->i_pts;
 320     g->i_dts   = p_list->i_dts;
 321
 322     /* free p_list */
 323     block_ChainRelease( p_list );
 324     return g;
 325 }
 326
 327 /*****************************************************************************
 328  * block_fifo_t management
 329  *****************************************************************************/
 330 block_fifo_t *__block_FifoNew( vlc_object_t *p_obj )
 331 {
 332     block_fifo_t *p_fifo;
 333
 334     p_fifo = malloc( sizeof( vlc_object_t ) );
 335     vlc_mutex_init( p_obj, &p_fifo->lock );
 336     vlc_cond_init( p_obj, &p_fifo->wait );
 337     p_fifo->i_depth = 0;
 338     p_fifo->p_first = NULL;
 339     p_fifo->pp_last = &p_fifo->p_first;
 340
 341     return p_fifo;
 342 }
 343
 344 void block_FifoRelease( block_fifo_t *p_fifo )
 345 {
 346     block_FifoEmpty( p_fifo );
 347     vlc_cond_destroy( &p_fifo->wait );
 348     vlc_mutex_destroy( &p_fifo->lock );
 349     free( p_fifo );
 350 }
 351
 352 void block_FifoEmpty( block_fifo_t *p_fifo )
 353 {
 354     block_t *b;
 355
 356     vlc_mutex_lock( &p_fifo->lock );
 357     for( b = p_fifo->p_first; b != NULL; )
 358     {
 359         block_t *p_next;
 360
 361         p_next = b->p_next;
 362         block_Release( b );
 363         b = p_next;
 364     }
 365
 366     p_fifo->i_depth = 0;
 367     p_fifo->p_first = NULL;
 368     p_fifo->pp_last = &p_fifo->p_first;
 369     vlc_mutex_unlock( &p_fifo->lock );
 370 }
 371
 372 int block_FifoPut( block_fifo_t *p_fifo, block_t *p_block )
 373 {
 374     int i_size = 0;
 375     vlc_mutex_lock( &p_fifo->lock );
 376
 377     do
 378     {
 379         i_size += p_block->i_buffer;
 380
 381         *p_fifo->pp_last = p_block;
 382         p_fifo->pp_last = &p_block->p_next;
 383         p_fifo->i_depth++;
 384
 385         p_block = p_block->p_next;
 386
 387     } while( p_block );
 388
 389     /* warn there is data in this fifo */
 390     vlc_cond_signal( &p_fifo->wait );
 391     vlc_mutex_unlock( &p_fifo->lock );
 392
 393     return i_size;
 394 }
 395
 396 block_t *block_FifoGet( block_fifo_t *p_fifo )
 397 {
 398     block_t *b;
 399
 400     vlc_mutex_lock( &p_fifo->lock );
 401
 402     if( p_fifo->p_first == NULL )
 403     {
 404         vlc_cond_wait( &p_fifo->wait, &p_fifo->lock );
 405     }
 406
 407     b = p_fifo->p_first;
 408
 409     p_fifo->p_first = b->p_next;
 410     p_fifo->i_depth--;
 411
 412     if( p_fifo->p_first == NULL )
 413     {
 414         p_fifo->pp_last = &p_fifo->p_first;
 415     }
 416
 417     vlc_mutex_unlock( &p_fifo->lock );
 418
 419     b->p_next = NULL;
 420     return( b );
 421 }
 422
 423 block_t *block_FifoShow( block_fifo_t *p_fifo )
 424 {
 425     block_t *b;
 426
 427     vlc_mutex_lock( &p_fifo->lock );
 428
 429     if( p_fifo->p_first == NULL )
 430     {
 431         vlc_cond_wait( &p_fifo->wait, &p_fifo->lock );
 432     }
 433
 434     b = p_fifo->p_first;
 435
 436     vlc_mutex_unlock( &p_fifo->lock );
 437
 438     return( b );
 439
 440 }
 441