Preparser: detach thread and race to idle
[vlc.git] / src / playlist / preparser.c
1 /*****************************************************************************
2  * preparse.c: Preparser thread.
3  *****************************************************************************
4  * Copyright © 1999-2009 the VideoLAN team
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
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 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 General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, 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     playlist_t          *p_playlist;
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( playlist_t *p_playlist, playlist_fetcher_t *p_fetcher )
60 {
61     playlist_preparser_t *p_preparser = malloc( sizeof(*p_preparser) );
62     if( !p_preparser )
63         return NULL;
64
65     p_preparser->p_playlist = p_playlist;
66     p_preparser->p_fetcher = p_fetcher;
67     vlc_mutex_init( &p_preparser->lock );
68     vlc_cond_init( &p_preparser->wait );
69     p_preparser->b_live = false;
70     p_preparser->i_art_policy = var_GetInteger( p_playlist, "album-art" );
71     p_preparser->i_waiting = 0;
72     p_preparser->pp_waiting = NULL;
73
74     return p_preparser;
75 }
76
77 void playlist_preparser_Push( playlist_preparser_t *p_preparser, input_item_t *p_item )
78 {
79     vlc_gc_incref( p_item );
80
81     vlc_mutex_lock( &p_preparser->lock );
82     INSERT_ELEM( p_preparser->pp_waiting, p_preparser->i_waiting,
83                  p_preparser->i_waiting, p_item );
84     if( !p_preparser->b_live )
85     {
86         vlc_thread_t th;
87
88         if( vlc_clone( &th, Thread, p_preparser, VLC_THREAD_PRIORITY_LOW ) )
89             msg_Warn( p_preparser->p_playlist,
90                       "cannot spawn pre-parser thread" );
91         else
92         {
93             vlc_detach( th );
94             p_preparser->b_live = true;
95         }
96     }
97     vlc_mutex_unlock( &p_preparser->lock );
98 }
99
100 void playlist_preparser_Delete( playlist_preparser_t *p_preparser )
101 {
102     vlc_mutex_lock( &p_preparser->lock );
103     /* Remove pending item to speed up preparser thread exit */
104     while( p_preparser->i_waiting > 0 )
105     {
106         vlc_gc_decref( p_preparser->pp_waiting[0] );
107         REMOVE_ELEM( p_preparser->pp_waiting, p_preparser->i_waiting, 0 );
108     }
109
110     while( p_preparser->b_live )
111         vlc_cond_wait( &p_preparser->wait, &p_preparser->lock );
112     vlc_mutex_unlock( &p_preparser->lock );
113
114     /* Destroy the item preparser */
115     vlc_cond_destroy( &p_preparser->wait );
116     vlc_mutex_destroy( &p_preparser->lock );
117     free( p_preparser );
118 }
119
120 /*****************************************************************************
121  * Privates functions
122  *****************************************************************************/
123 /**
124  * This function preparses an item when needed.
125  */
126 static void Preparse( playlist_t *p_playlist, input_item_t *p_item )
127 {
128     vlc_mutex_lock( &p_item->lock );
129     int i_type = p_item->i_type;
130     vlc_mutex_unlock( &p_item->lock );
131
132     if( i_type != ITEM_TYPE_FILE )
133         return;
134
135     stats_TimerStart( p_playlist, "Preparse run", STATS_TIMER_PREPARSE );
136
137     /* Do not preparse if it is already done (like by playing it) */
138     if( !input_item_IsPreparsed( p_item ) )
139     {
140         input_Preparse( VLC_OBJECT(p_playlist), p_item );
141         input_item_SetPreparsed( p_item, true );
142
143         var_SetAddress( p_playlist, "item-change", p_item );
144     }
145
146     stats_TimerStop( p_playlist, STATS_TIMER_PREPARSE );
147 }
148
149 /**
150  * This function ask the fetcher object to fetch the art when needed
151  */
152 static void Art( playlist_preparser_t *p_preparser, input_item_t *p_item )
153 {
154     playlist_t *p_playlist = p_preparser->p_playlist;
155     playlist_fetcher_t *p_fetcher = p_preparser->p_fetcher;
156
157     bool b_fetch = false;
158     /* If we haven't retrieved enough meta, add to secondary queue
159      * which will run the "meta fetchers".
160      * This only checks for meta, not for art
161      * \todo don't do this for things we won't get meta for, like vids
162      */
163
164     vlc_mutex_lock( &p_item->lock );
165     if( p_item->p_meta )
166     {
167         const char *psz_arturl = vlc_meta_Get( p_item->p_meta, vlc_meta_ArtworkURL );
168         const char *psz_name = vlc_meta_Get( p_item->p_meta, vlc_meta_Title );
169
170         if( p_preparser->i_art_policy == ALBUM_ART_ALL &&
171             ( !psz_arturl || strncmp( psz_arturl, "file://", 7 ) ) )
172         {
173             msg_Dbg( p_playlist, "meta ok for %s, need to fetch art", psz_name );
174             b_fetch = true;
175         }
176         else
177         {
178             msg_Dbg( p_playlist, "no fetch required for %s (art currently %s)",
179                      psz_name, psz_arturl );
180         }
181     }
182     vlc_mutex_unlock( &p_item->lock );
183
184     if( b_fetch && p_fetcher )
185         playlist_fetcher_Push( p_fetcher, p_item );
186 }
187
188 /**
189  * This function does the preparsing and issues the art fetching requests
190  */
191 static void *Thread( void *data )
192 {
193     playlist_preparser_t *p_preparser = data;
194     playlist_t *p_playlist = p_preparser->p_playlist;
195
196     for( ;; )
197     {
198         input_item_t *p_current;
199
200         /* */
201         vlc_mutex_lock( &p_preparser->lock );
202         if( p_preparser->i_waiting > 0 )
203         {
204             p_current = p_preparser->pp_waiting[0];
205             REMOVE_ELEM( p_preparser->pp_waiting, p_preparser->i_waiting, 0 );
206         }
207         else
208         {
209             p_current = NULL;
210             p_preparser->b_live = false;
211         }
212         vlc_mutex_unlock( &p_preparser->lock );
213
214         if( !p_current )
215             break;
216
217         Preparse( p_playlist, p_current );
218
219         Art( p_preparser, p_current );
220     }
221     return NULL;
222 }
223