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
 243     if( *pp_list == NULL )
 244     {
 245         *pp_list = p_block;
 246     }
 247     else
 248     {
 249         block_t *p = *pp_list;
 250
 251         while( p->p_next )
 252         {
 253             p = p->p_next;
 254         }
 255         p->p_next = p_block;
 256     }
 257 }
 258
 259 void block_ChainRelease( block_t *p_block )
 260 {
 261     while( p_block )
 262     {
 263         block_t *p_next;
 264         p_next = p_block->p_next;
 265         p_block->pf_release( p_block );
 266         p_block = p_next;
 267     }
 268 }
 269
 270 int block_ChainExtract( block_t *p_list, void *p_data, int i_max )
 271 {
 272     block_t *b;
 273     int     i_total = 0;
 274     uint8_t *p = p_data;
 275
 276     for( b = p_list; b != NULL; b = b->p_next )
 277     {
 278         int i_copy;
 279
 280         i_copy = __MIN( i_max, b->i_buffer );
 281         if( i_copy > 0 )
 282         {
 283             memcpy( p, b->p_buffer, i_copy );
 284             i_max   -= i_copy;
 285             i_total += i_copy;
 286             p       += i_copy;
 287
 288             if( i_max == 0 )
 289             {
 290                 return i_total;
 291             }
 292         }
 293     }
 294     return i_total;
 295 }
 296
 297 block_t *block_ChainGather( block_t *p_list )
 298 {
 299     int     i_total = 0;
 300     block_t *b, *g;
 301
 302     if( p_list->p_next == NULL )
 303     {
 304         /* only one, so no need */
 305         return p_list;
 306     }
 307
 308     for( b = p_list; b != NULL; b = b->p_next )
 309     {
 310         i_total += b->i_buffer;
 311     }
 312
 313     g = block_New( p_list->p_manager, i_total );
 314     block_ChainExtract( p_list, g->p_buffer, g->i_buffer );
 315
 316     g->i_flags = p_list->i_flags;
 317     g->i_pts   = p_list->i_pts;
 318     g->i_dts   = p_list->i_dts;
 319
 320     /* free p_list */
 321     block_ChainRelease( p_list );
 322     return g;
 323 }
 324
 325 /*****************************************************************************
 326  * block_fifo_t management
 327  *****************************************************************************/
 328 block_fifo_t *__block_FifoNew( vlc_object_t *p_obj )
 329 {
 330     block_fifo_t *p_fifo;
 331
 332     p_fifo = malloc( sizeof( vlc_object_t ) );
 333     vlc_mutex_init( p_obj, &p_fifo->lock );
 334     vlc_cond_init( p_obj, &p_fifo->wait );
 335     p_fifo->i_depth = 0;
 336     p_fifo->p_first = NULL;
 337     p_fifo->pp_last = &p_fifo->p_first;
 338
 339     return p_fifo;
 340 }
 341
 342 void block_FifoRelease( block_fifo_t *p_fifo )
 343 {
 344     block_FifoEmpty( p_fifo );
 345     vlc_cond_destroy( &p_fifo->wait );
 346     vlc_mutex_destroy( &p_fifo->lock );
 347     free( p_fifo );
 348 }
 349
 350 void block_FifoEmpty( block_fifo_t *p_fifo )
 351 {
 352     block_t *b;
 353
 354     vlc_mutex_lock( &p_fifo->lock );
 355     for( b = p_fifo->p_first; b != NULL; )
 356     {
 357         block_t *p_next;
 358
 359         p_next = b->p_next;
 360         block_Release( b );
 361         b = p_next;
 362     }
 363
 364     p_fifo->i_depth = 0;
 365     p_fifo->p_first = NULL;
 366     p_fifo->pp_last = &p_fifo->p_first;
 367     vlc_mutex_unlock( &p_fifo->lock );
 368 }
 369
 370 int block_FifoPut( block_fifo_t *p_fifo, block_t *p_block )
 371 {
 372     int i_size = 0;
 373     vlc_mutex_lock( &p_fifo->lock );
 374
 375     do
 376     {
 377         i_size += p_block->i_buffer;
 378
 379         *p_fifo->pp_last = p_block;
 380         p_fifo->pp_last = &p_block->p_next;
 381         p_fifo->i_depth++;
 382
 383         p_block = p_block->p_next;
 384
 385     } while( p_block );
 386
 387     /* warn there is data in this fifo */
 388     vlc_cond_signal( &p_fifo->wait );
 389     vlc_mutex_unlock( &p_fifo->lock );
 390
 391     return i_size;
 392 }
 393
 394 block_t *block_FifoGet( block_fifo_t *p_fifo )
 395 {
 396     block_t *b;
 397
 398     vlc_mutex_lock( &p_fifo->lock );
 399
 400     if( p_fifo->p_first == NULL )
 401     {
 402         vlc_cond_wait( &p_fifo->wait, &p_fifo->lock );
 403     }
 404
 405     b = p_fifo->p_first;
 406
 407     p_fifo->p_first = b->p_next;
 408     p_fifo->i_depth--;
 409
 410     if( p_fifo->p_first == NULL )
 411     {
 412         p_fifo->pp_last = &p_fifo->p_first;
 413     }
 414
 415     vlc_mutex_unlock( &p_fifo->lock );
 416
 417     b->p_next = NULL;
 418     return( b );
 419 }
 420
 421 block_t *block_FifoShow( block_fifo_t *p_fifo )
 422 {
 423     block_t *b;
 424
 425     vlc_mutex_lock( &p_fifo->lock );
 426
 427     if( p_fifo->p_first == NULL )
 428     {
 429         vlc_cond_wait( &p_fifo->wait, &p_fifo->lock );
 430     }
 431
 432     b = p_fifo->p_first;
 433
 434     vlc_mutex_unlock( &p_fifo->lock );
 435
 436     return( b );
 437
 438 }
 439