git.sesse.net Git - vlc/blob - modules/access_filter/timeshift.c

   1 /*****************************************************************************
   2  * timeshift.c
   3  *****************************************************************************
   4  * Copyright (C) 2005 VideoLAN
   5  * $Id: demux.c 7546 2004-04-29 13:53:29Z gbazin $
   6  *
   7  * Author: Laurent Aimar <fenrir@via.ecp.fr>
   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 <errno.h>
  30
  31 #include <vlc/vlc.h>
  32 #include <vlc/input.h>
  33 #include <unistd.h>
  34
  35 /*****************************************************************************
  36  * Module descriptor
  37  *****************************************************************************/
  38 static int  Open ( vlc_object_t * );
  39 static void Close( vlc_object_t * );
  40
  41 vlc_module_begin();
  42     set_description( _("Timeshift") );
  43     set_category( CAT_INPUT );
  44     set_subcategory( SUBCAT_INPUT_ACCESS_FILTER );
  45     set_capability( "access_filter", 0 );
  46     add_shortcut( "timeshift" );
  47     set_callbacks( Open, Close );
  48 vlc_module_end();
  49
  50 /*****************************************************************************
  51  * Local prototypes
  52  *****************************************************************************/
  53
  54 static block_t *Block  ( access_t *p_access );
  55 static int      Control( access_t *, int i_query, va_list args );
  56 static void     Thread ( access_t * );
  57
  58 #define TIMESHIFT_FIFO_MAX (4*1024*1024)
  59 #define TIMESHIFT_FIFO_MIN (TIMESHIFT_FIFO_MAX/4)
  60
  61 struct access_sys_t
  62 {
  63     block_fifo_t *p_fifo;
  64
  65     vlc_bool_t b_opened;
  66
  67     FILE *t1, *t2;
  68
  69     char *psz_tmp1;
  70     char *psz_tmp2;
  71
  72     FILE *w;
  73     int i_w;
  74
  75     FILE *r;
  76 };
  77
  78 /*****************************************************************************
  79  * Open:
  80  *****************************************************************************/
  81 static int Open( vlc_object_t *p_this )
  82 {
  83     access_t *p_access = (access_t*)p_this;
  84     access_t *p_src = p_access->p_source;
  85     access_sys_t *p_sys;
  86     vlc_bool_t b_bool;
  87 #ifdef WIN32
  88     char buffer[4096];
  89     int i_size;
  90 #endif
  91
  92     /* Only work with not pace controled access */
  93     if( access2_Control( p_src, ACCESS_CAN_CONTROL_PACE, &b_bool ) || b_bool )
  94     {
  95         msg_Dbg( p_src, "ACCESS_CAN_CONTROL_PACE" );
  96         return VLC_EGENERIC;
  97     }
  98     /* Refuse access that can be paused */
  99     if( access2_Control( p_src, ACCESS_CAN_PAUSE, &b_bool ) || b_bool )
 100     {
 101         msg_Dbg( p_src, "ACCESS_CAN_PAUSE: timeshift useless" );
 102         return VLC_EGENERIC;
 103     }
 104
 105     /* */
 106     p_access->pf_read = NULL;
 107     p_access->pf_block = Block;
 108     p_access->pf_seek = NULL;
 109     p_access->pf_control = Control;
 110
 111     p_access->info = p_src->info;
 112
 113     p_access->p_sys = p_sys = malloc( sizeof( access_sys_t ) );
 114
 115     /* */
 116     p_sys->p_fifo = block_FifoNew( p_access );
 117     p_sys->b_opened = VLC_FALSE;
 118     p_sys->t1 = p_sys->t2 = NULL;
 119     p_sys->w = p_sys->r = NULL;
 120     p_sys->i_w = 0;
 121
 122 #ifdef WIN32
 123     i_size = GetTempPath( 4095, buffer );
 124     if( i_size <= 0 || i_size >= 4095 )
 125     {
 126         if( getcwd( buffer, 4095 ) == NULL )
 127             strcpy( buffer, "c:" );
 128     }
 129     /* remove last \\ if any */
 130     if( buffer[strlen(buffer)-1] == '\\' )
 131         buffer[strlen(buffer)-1] = '\0';
 132
 133     asprintf( &p_sys->psz_tmp1, "%s\\vlc-timeshift-%d-%d-1.dat",
 134               buffer, GetCurrentProcessId(), p_access->i_object_id );
 135     asprintf( &p_sys->psz_tmp2, "%s\\vlc-timeshift-%d-%d-2.dat",
 136               buffer, GetCurrentProcessId(), p_access->i_object_id );
 137 #else
 138     asprintf( &p_sys->psz_tmp1, "/tmp/vlc-timeshift-%d-%d-1.dat",
 139               getpid(), p_access->i_object_id );
 140     asprintf( &p_sys->psz_tmp2, "/tmp/vlc-timeshift-%d-%d-2.dat",
 141               getpid(), p_access->i_object_id );
 142 #endif
 143
 144     if( vlc_thread_create( p_access, "timeshift thread", Thread,
 145                            VLC_THREAD_PRIORITY_LOW, VLC_FALSE ) )
 146     {
 147         msg_Err( p_access, "cannot spawn timeshift access thread" );
 148         return VLC_EGENERIC;
 149     }
 150
 151     return VLC_SUCCESS;
 152 }
 153
 154 /*****************************************************************************
 155  * Close:
 156  *****************************************************************************/
 157 static void Close( vlc_object_t *p_this )
 158 {
 159     access_t     *p_access = (access_t*)p_this;
 160     access_sys_t *p_sys = p_access->p_sys;
 161
 162     /* */
 163     msg_Dbg( p_access, "timeshift close called" );
 164     vlc_thread_join( p_access );
 165
 166     if( p_sys->b_opened )
 167     {
 168         if( p_sys->t1 ) fclose( p_sys->t1 );
 169         if( p_sys->t2 ) fclose( p_sys->t2 );
 170         unlink( p_sys->psz_tmp1 );
 171         unlink( p_sys->psz_tmp2 );
 172     }
 173
 174     free( p_sys->psz_tmp1 );
 175     free( p_sys->psz_tmp2 );
 176
 177     block_FifoRelease( p_sys->p_fifo );
 178     free( p_sys );
 179 }
 180
 181 /*****************************************************************************
 182  *
 183  *****************************************************************************/
 184 static block_t *Block( access_t *p_access )
 185 {
 186     access_sys_t *p_sys = p_access->p_sys;
 187
 188     if( p_access->b_die )
 189     {
 190         p_access->info.b_eof = VLC_TRUE;
 191         return NULL;
 192     }
 193
 194     return block_FifoGet( p_sys->p_fifo );
 195 }
 196
 197 /*****************************************************************************
 198  *
 199  *****************************************************************************/
 200 static int Control( access_t *p_access, int i_query, va_list args )
 201 {
 202     access_t     *p_src = p_access->p_source;
 203
 204     vlc_bool_t   *pb_bool;
 205     int          *pi_int;
 206     int64_t      *pi_64;
 207
 208     switch( i_query )
 209     {
 210         /* */
 211         case ACCESS_CAN_SEEK:
 212         case ACCESS_CAN_FASTSEEK:
 213             pb_bool = (vlc_bool_t*)va_arg( args, vlc_bool_t* );
 214             *pb_bool = VLC_FALSE;
 215             break;
 216
 217         case ACCESS_CAN_CONTROL_PACE:   /* Not really true */
 218         case ACCESS_CAN_PAUSE:
 219             pb_bool = (vlc_bool_t*)va_arg( args, vlc_bool_t* );
 220             *pb_bool = VLC_TRUE;
 221             break;
 222
 223         /* */
 224         case ACCESS_GET_MTU:
 225             pi_int = (int*)va_arg( args, int * );
 226             *pi_int = 0;
 227             break;
 228
 229         case ACCESS_GET_PTS_DELAY:
 230             pi_64 = (int64_t*)va_arg( args, int64_t * );
 231             return access2_Control( p_src, ACCESS_GET_PTS_DELAY, pi_64 );
 232         /* */
 233         case ACCESS_SET_PAUSE_STATE:
 234             return VLC_SUCCESS;
 235
 236         case ACCESS_GET_TITLE_INFO:
 237         case ACCESS_SET_TITLE:
 238         case ACCESS_SET_SEEKPOINT:
 239         case ACCESS_GET_META:
 240             return VLC_EGENERIC;
 241
 242         case ACCESS_SET_PRIVATE_ID_STATE:
 243         case ACCESS_GET_PRIVATE_ID_STATE:
 244         case ACCESS_SET_PRIVATE_ID_CA:
 245             return access2_vaControl( p_src, i_query, args );
 246
 247         default:
 248             msg_Warn( p_access, "unimplemented query in control" );
 249             return VLC_EGENERIC;
 250
 251     }
 252     return VLC_SUCCESS;
 253 }
 254
 255 /*****************************************************************************
 256  *
 257  *****************************************************************************/
 258 static void Thread( access_t *p_access )
 259 {
 260     access_sys_t *p_sys = p_access->p_sys;
 261     access_t     *p_src = p_access->p_source;
 262     int i_loop = 0;
 263
 264     while( !p_access->b_die )
 265     {
 266         block_t *p_block;
 267
 268         /* Get a new block */
 269         if( p_src->pf_block )
 270         {
 271             p_block = p_src->pf_block( p_src );
 272
 273             if( p_block == NULL )
 274             {
 275                 if( p_src->info.b_eof )
 276                     break;
 277
 278                 msleep( 1000 );
 279                 continue;
 280             }
 281         }
 282         else
 283         {
 284             if( ( p_block = block_New( p_access, 2048 ) ) == NULL )
 285                 break;
 286
 287             p_block->i_buffer = p_src->pf_read( p_src, p_block->p_buffer, 2048);
 288             if( p_block->i_buffer < 0 )
 289             {
 290                 block_Release( p_block );
 291                 if( p_block->i_buffer == 0 )
 292                     break;
 293                 msleep( 1000 );
 294                 continue;
 295             }
 296         }
 297
 298         /* Open dump files if we need them */
 299         if( p_sys->p_fifo->i_size >= TIMESHIFT_FIFO_MAX && !p_sys->b_opened )
 300         {
 301             msg_Dbg( p_access, "opening first temporary files (%s)",
 302                      p_sys->psz_tmp1 );
 303
 304             p_sys->b_opened = VLC_TRUE;
 305             p_sys->t1 = p_sys->t2 = NULL;
 306             p_sys->w = p_sys->r = NULL;
 307
 308             p_sys->t1 = fopen( p_sys->psz_tmp1, "w+b" );
 309             if( p_sys->t1 )
 310             {
 311                 msg_Dbg( p_access, "opening second temporary files (%s)",
 312                          p_sys->psz_tmp2 );
 313
 314                 p_sys->t2 = fopen( p_sys->psz_tmp2, "w+b" );
 315                 if( p_sys->t2 )
 316                 {
 317                     p_sys->w = p_sys->t1;
 318                     p_sys->i_w = 0;
 319
 320                     msg_Dbg( p_access, "start writing into temporary file" );
 321                 }
 322                 else
 323                 {
 324                     msg_Err( p_access, "cannot open temporary file '%s' (%s)",
 325                              p_sys->psz_tmp2, strerror(errno) );
 326                     fclose( p_sys->t1 );
 327                     p_sys->t1 = NULL;
 328                 }
 329             }
 330             else
 331             {
 332                 msg_Err( p_access, "cannot open temporary file '%s' (%s)",
 333                          p_sys->psz_tmp1, strerror(errno) );
 334             }
 335         }
 336
 337         if( p_sys->w )
 338         {
 339             int i_write;
 340
 341             /* Dump the block */
 342             i_write = fwrite( p_block->p_buffer, 1, p_block->i_buffer,
 343                               p_sys->w );
 344             block_Release( p_block );
 345
 346             if( i_write > 0 )
 347                 p_sys->i_w += i_write;
 348             else
 349                 msg_Warn( p_access, "cannot write data" );
 350
 351             /* Start reading from a file if fifo isn't at 25% */
 352             if( p_sys->p_fifo->i_size < TIMESHIFT_FIFO_MIN && !p_sys->r )
 353             {
 354                 msg_Dbg( p_access, "start reading from temporary file (dumped=%d)", p_sys->i_w );
 355
 356                 p_sys->r = p_sys->w;
 357                 fseek( p_sys->r, 0, SEEK_SET );
 358
 359                 p_sys->w = p_sys->t2;
 360                 p_sys->i_w = 0;
 361             }
 362
 363             if( p_sys->r )
 364             {
 365                 while( p_sys->p_fifo->i_size < TIMESHIFT_FIFO_MIN )
 366                 {
 367                     p_block = block_New( p_access, 4096 );
 368                     p_block->i_buffer = fread( p_block->p_buffer, 1, 4096,
 369                                                p_sys->r );
 370
 371                     if( p_block->i_buffer > 0 )
 372                     {
 373                         block_FifoPut( p_sys->p_fifo, p_block );
 374                     }
 375                     else if( p_sys->i_w > 32*1024)
 376                     {
 377                         FILE *tmp;
 378                         block_Release( p_block );
 379
 380                         msg_Dbg( p_access, "switching temporary files (dumped=%d)", p_sys->i_w );
 381
 382                         /* Switch read/write */
 383                         tmp = p_sys->r;
 384
 385                         p_sys->r = p_sys->w;
 386                         fseek( p_sys->r, 0, SEEK_SET );
 387
 388                         p_sys->w = tmp;
 389                         fseek( p_sys->w, 0, SEEK_SET );
 390                         ftruncate( fileno(p_sys->w), 0 );
 391                         p_sys->i_w = 0;
 392                     }
 393                     else
 394                     {
 395                         msg_Dbg( p_access, "removing temporary files" );
 396
 397                         /* We will remove the need of tmp files */
 398                         if( p_sys->i_w > 0 )
 399                         {
 400                             msg_Dbg( p_access, "loading temporary file" );
 401                             fseek( p_sys->w, 0, SEEK_SET );
 402                             for( ;; )
 403                             {
 404                                 p_block = block_New( p_access, 4096 );
 405                                 p_block->i_buffer = fread( p_block->p_buffer,
 406                                                            1, 4096,
 407                                                            p_sys->w );
 408                                 if( p_block->i_buffer <= 0 )
 409                                 {
 410                                     block_Release( p_block );
 411                                     break;
 412                                 }
 413                                 block_FifoPut( p_sys->p_fifo, p_block );
 414                             }
 415                         }
 416
 417                         p_sys->b_opened = VLC_FALSE;
 418
 419                         fclose( p_sys->t1 );
 420                         fclose( p_sys->t2 );
 421
 422                         p_sys->t1 = p_sys->t2 = NULL;
 423                         p_sys->w = p_sys->r = NULL;
 424
 425                         unlink( p_sys->psz_tmp1 );
 426                         unlink( p_sys->psz_tmp2 );
 427                         break;
 428                     }
 429                 }
 430             }
 431         }
 432         else if( p_sys->p_fifo->i_size < TIMESHIFT_FIFO_MAX )
 433         {
 434             block_FifoPut( p_sys->p_fifo, p_block );
 435         }
 436         else
 437         {
 438             /* We failed to opened files so trash new data */
 439             block_Release( p_block );
 440         }
 441 #if 0
 442         if( (i_loop % 400) == 0 )
 443             msg_Dbg( p_access, "timeshift: buff=%d", p_sys->p_fifo->i_size );
 444 #endif
 445         i_loop++;
 446     }
 447
 448     msg_Warn( p_access, "timeshift: EOF" );
 449
 450     /* Send dummy packet to avoid deadlock in TShiftBlock */
 451     for( i_loop = 0; i_loop < 2; i_loop++ )
 452     {
 453         block_t *p_dummy = block_New( p_access, 128 );
 454
 455         p_dummy->i_flags |= BLOCK_FLAG_DISCONTINUITY;
 456         memset( p_dummy->p_buffer, 0, p_dummy->i_buffer );
 457
 458         block_FifoPut( p_sys->p_fifo, p_dummy );
 459     }
 460 }
 461