src/playlist/preparser.c

   1 /*****************************************************************************
   2  * preparser.c: Preparser thread.
   3  *****************************************************************************
   4  * Copyright © 1999-2009 VLC authors and VideoLAN
   5  * $Id$
   6  *
   7  * Authors: Samuel Hocevar <sam@zoy.org>
   8  *          Clément Stenac <zorglub@videolan.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU Lesser General Public License as published by
  12  * the Free Software Foundation; either version 2.1 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public License
  21  * along with this program; if not, write to the Free Software Foundation,
  22  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24 #ifdef HAVE_CONFIG_H
  25 # include "config.h"
  26 #endif
  27
  28 #include <vlc_common.h>
  29 #include <vlc_playlist.h>
  30
  31 #include "art.h"
  32 #include "fetcher.h"
  33 #include "preparser.h"
  34 #include "../input/input_interface.h"
  35
  36
  37 /*****************************************************************************
  38  * Structures/definitions
  39  *****************************************************************************/
  40 struct playlist_preparser_t
  41 {
  42     vlc_object_t        *object;
  43     playlist_fetcher_t  *p_fetcher;
  44
  45     vlc_mutex_t     lock;
  46     vlc_cond_t      wait;
  47     bool            b_live;
  48     input_item_t  **pp_waiting;
  49     int             i_waiting;
  50
  51     int             i_art_policy;
  52 };
  53
  54 static void *Thread( void * );
  55
  56 /*****************************************************************************
  57  * Public functions
  58  *****************************************************************************/
  59 playlist_preparser_t *playlist_preparser_New( vlc_object_t *parent,
  60                                               playlist_fetcher_t *p_fetcher )
  61 {
  62     playlist_preparser_t *p_preparser = malloc( sizeof(*p_preparser) );
  63     if( !p_preparser )
  64         return NULL;
  65
  66     p_preparser->object = parent;
  67     p_preparser->p_fetcher = p_fetcher;
  68     vlc_mutex_init( &p_preparser->lock );
  69     vlc_cond_init( &p_preparser->wait );
  70     p_preparser->b_live = false;
  71     p_preparser->i_art_policy = var_InheritInteger( parent, "album-art" );
  72     p_preparser->i_waiting = 0;
  73     p_preparser->pp_waiting = NULL;
  74
  75     return p_preparser;
  76 }
  77
  78 void playlist_preparser_Push( playlist_preparser_t *p_preparser, input_item_t *p_item )
  79 {
  80     vlc_gc_incref( p_item );
  81
  82     vlc_mutex_lock( &p_preparser->lock );
  83     INSERT_ELEM( p_preparser->pp_waiting, p_preparser->i_waiting,
  84                  p_preparser->i_waiting, p_item );
  85     if( !p_preparser->b_live )
  86     {
  87         if( vlc_clone_detach( NULL, Thread, p_preparser,
  88                               VLC_THREAD_PRIORITY_LOW ) )
  89             msg_Warn( p_preparser->object, "cannot spawn pre-parser thread" );
  90         else
  91             p_preparser->b_live = true;
  92     }
  93     vlc_mutex_unlock( &p_preparser->lock );
  94 }
  95
  96 void playlist_preparser_Delete( playlist_preparser_t *p_preparser )
  97 {
  98     vlc_mutex_lock( &p_preparser->lock );
  99     /* Remove pending item to speed up preparser thread exit */
 100     while( p_preparser->i_waiting > 0 )
 101     {
 102         vlc_gc_decref( p_preparser->pp_waiting[0] );
 103         REMOVE_ELEM( p_preparser->pp_waiting, p_preparser->i_waiting, 0 );
 104     }
 105
 106     while( p_preparser->b_live )
 107         vlc_cond_wait( &p_preparser->wait, &p_preparser->lock );
 108     vlc_mutex_unlock( &p_preparser->lock );
 109
 110     /* Destroy the item preparser */
 111     vlc_cond_destroy( &p_preparser->wait );
 112     vlc_mutex_destroy( &p_preparser->lock );
 113     free( p_preparser );
 114 }
 115
 116 /*****************************************************************************
 117  * Privates functions
 118  *****************************************************************************/
 119 /**
 120  * This function preparses an item when needed.
 121  */
 122 static void Preparse( vlc_object_t *obj, input_item_t *p_item )
 123 {
 124     vlc_mutex_lock( &p_item->lock );
 125     int i_type = p_item->i_type;
 126     vlc_mutex_unlock( &p_item->lock );
 127
 128     if( i_type != ITEM_TYPE_FILE )
 129     {
 130         input_item_SetPreparsed( p_item, true );
 131         return;
 132     }
 133
 134     /* Do not preparse if it is already done (like by playing it) */
 135     if( !input_item_IsPreparsed( p_item ) )
 136     {
 137         input_Preparse( obj, p_item );
 138         input_item_SetPreparsed( p_item, true );
 139
 140         var_SetAddress( obj, "item-change", p_item );
 141     }
 142 }
 143
 144 /**
 145  * This function ask the fetcher object to fetch the art when needed
 146  */
 147 static void Art( playlist_preparser_t *p_preparser, input_item_t *p_item )
 148 {
 149     vlc_object_t *obj = p_preparser->object;
 150     playlist_fetcher_t *p_fetcher = p_preparser->p_fetcher;
 151
 152     bool b_fetch = false;
 153     /* If we haven't retrieved enough meta, add to secondary queue
 154      * which will run the "meta fetchers".
 155      * This only checks for meta, not for art
 156      * \todo don't do this for things we won't get meta for, like vids
 157      */
 158
 159     vlc_mutex_lock( &p_item->lock );
 160     if( p_item->p_meta )
 161     {
 162         const char *psz_arturl = vlc_meta_Get( p_item->p_meta, vlc_meta_ArtworkURL );
 163         const char *psz_name = vlc_meta_Get( p_item->p_meta, vlc_meta_Title );
 164
 165         if( p_preparser->i_art_policy == ALBUM_ART_ALL &&
 166                 ( !psz_arturl ||
 167                   ( strncmp( psz_arturl, "file://", 7 ) &&
 168                     strncmp( psz_arturl, "attachment://", 13 ) ) ) )
 169         {
 170             msg_Dbg( obj, "meta ok for %s, need to fetch art",
 171                      psz_name ? psz_name : "(null)" );
 172             b_fetch = true;
 173         }
 174         else
 175         {
 176             msg_Dbg( obj, "no fetch required for %s (art currently %s)",
 177                      psz_name ? psz_name : "(null)",
 178                      psz_arturl ? psz_arturl : "(null)" );
 179         }
 180     }
 181     vlc_mutex_unlock( &p_item->lock );
 182
 183     if( b_fetch && p_fetcher )
 184         playlist_fetcher_Push( p_fetcher, p_item );
 185 }
 186
 187 /**
 188  * This function does the preparsing and issues the art fetching requests
 189  */
 190 static void *Thread( void *data )
 191 {
 192     playlist_preparser_t *p_preparser = data;
 193     vlc_object_t *obj = p_preparser->object;
 194
 195     for( ;; )
 196     {
 197         input_item_t *p_current;
 198
 199         /* */
 200         vlc_mutex_lock( &p_preparser->lock );
 201         if( p_preparser->i_waiting > 0 )
 202         {
 203             p_current = p_preparser->pp_waiting[0];
 204             REMOVE_ELEM( p_preparser->pp_waiting, p_preparser->i_waiting, 0 );
 205         }
 206         else
 207         {
 208             p_current = NULL;
 209             p_preparser->b_live = false;
 210             vlc_cond_signal( &p_preparser->wait );
 211         }
 212         vlc_mutex_unlock( &p_preparser->lock );
 213
 214         if( !p_current )
 215             break;
 216
 217         Preparse( obj, p_current );
 218
 219         Art( p_preparser, p_current );
 220         vlc_gc_decref(p_current);
 221     }
 222     return NULL;
 223 }
 224