Clean up/document a bit preparser code.

src/playlist/preparser.c

@@ -33,8 +33,27 @@
 #include "preparser.h"
 #include "../input/input_interface.h"
 
+
+/*****************************************************************************
+ * Structures/definitions
+ *****************************************************************************/
+struct playlist_preparser_t
+{
+    playlist_t          *p_playlist;
+    playlist_fetcher_t  *p_fetcher;
+
+    vlc_thread_t    thread;
+    vlc_mutex_t     lock;
+    vlc_cond_t      wait;
+    input_item_t  **pp_waiting;
+    int             i_waiting;
+};
+
 static void *Thread( void * );
 
+/*****************************************************************************
+ * Public functions
+ *****************************************************************************/
 playlist_preparser_t *playlist_preparser_New( playlist_t *p_playlist, playlist_fetcher_t *p_fetcher )
 {
     playlist_preparser_t *p_preparser = malloc( sizeof(*p_preparser) );
@@ -82,79 +101,116 @@ void playlist_preparser_Delete( playlist_preparser_t *p_preparser )
     }
     vlc_cond_destroy( &p_preparser->wait );
     vlc_mutex_destroy( &p_preparser->lock );
+    free( p_preparser );
 }
 
-static void *Thread( void *data )
+/*****************************************************************************
+ * Privates functions
+ *****************************************************************************/
+/**
+ * This function preparses an item when needed.
+ */
+static void Preparse( playlist_t *p_playlist, input_item_t *p_item )
 {
-    playlist_preparser_t *p_preparser = data;
-    playlist_t *p_playlist = p_preparser->p_playlist;
-    playlist_fetcher_t *p_fetcher = p_preparser->p_fetcher;
-
-    for( ;; )
-    {
-        input_item_t *p_current;
+    vlc_mutex_lock( &p_item->lock );
+    int i_type = p_item->i_type;
+    vlc_mutex_unlock( &p_item->lock );
 
-        /* */
-        vlc_mutex_lock( &p_preparser->lock );
-        mutex_cleanup_push( &p_preparser->lock );
-
-        while( p_preparser->i_waiting == 0 )
-            vlc_cond_wait( &p_preparser->wait, &p_preparser->lock );
-
-        p_current = p_preparser->pp_waiting[0];
-        REMOVE_ELEM( p_preparser->pp_waiting, p_preparser->i_waiting, 0 );
-        vlc_cleanup_run( );
+    if( i_type != ITEM_TYPE_FILE )
+        return;
 
-        if( !p_current )
-            continue;
+    stats_TimerStart( p_playlist, "Preparse run", STATS_TIMER_PREPARSE );
 
-        int canc = vlc_savecancel ();
-        {
-            PL_LOCK;
-            if( p_current->i_type == ITEM_TYPE_FILE )
-            {
-                stats_TimerStart( p_playlist, "Preparse run",
-                                  STATS_TIMER_PREPARSE );
     /* Do not preparse if it is already done (like by playing it) */
-                if( !input_item_IsPreparsed( p_current ) )
+    if( !input_item_IsPreparsed( p_item ) )
     {
-                    PL_UNLOCK;
-                    input_Preparse( p_playlist, p_current );
-                    PL_LOCK;
+        input_Preparse( p_playlist, p_item );
+        input_item_SetPreparsed( p_item, true );
+
+        var_SetInteger( p_playlist, "item-change", p_item->i_id );
     }
+
     stats_TimerStop( p_playlist, STATS_TIMER_PREPARSE );
-                PL_UNLOCK;
-                input_item_SetPreparsed( p_current, true );
-                var_SetInteger( p_playlist, "item-change", p_current->i_id );
-                PL_LOCK;
-            }
+}
+
+/**
+ * This function ask the fetcher object to fetch the art when needed
+ */
+static void Art( playlist_preparser_t *p_preparser, input_item_t *p_item )
+{
+    playlist_t *p_playlist = p_preparser->p_playlist;
+    playlist_fetcher_t *p_fetcher = p_preparser->p_fetcher;
+
+    bool b_fetch = false;
     /* If we haven't retrieved enough meta, add to secondary queue
      * which will run the "meta fetchers".
      * This only checks for meta, not for art
      * \todo don't do this for things we won't get meta for, like vids
      */
-            char *psz_arturl = input_item_GetArtURL( p_current );
-            char *psz_name = input_item_GetName( p_current );
+
+    vlc_mutex_lock( &p_item->lock );
+    if( p_item->p_meta )
+    {
+        const char *psz_arturl = vlc_meta_Get( p_item->p_meta, vlc_meta_ArtworkURL );
+        const char *psz_name = vlc_meta_Get( p_item->p_meta, vlc_meta_Title );
+
         if( p_fetcher && p_fetcher->i_art_policy == ALBUM_ART_ALL &&
             ( !psz_arturl || strncmp( psz_arturl, "file://", 7 ) ) )
         {
             msg_Dbg( p_playlist, "meta ok for %s, need to fetch art", psz_name );
-                playlist_fetcher_Push( p_fetcher, p_current );
+            b_fetch = true;
         }
         else
         {
             msg_Dbg( p_playlist, "no fetch required for %s (art currently %s)",
                      psz_name, psz_arturl );
         }
-            vlc_gc_decref( p_current );
-            free( psz_name );
-            free( psz_arturl );
-	    PL_UNLOCK;
     }
+    vlc_mutex_unlock( &p_item->lock );
+
+    if( b_fetch )
+        playlist_fetcher_Push( p_fetcher, p_item );
+}
+
+/**
+ * This function does the preparsing and issues the art fetching requests
+ */
+static void *Thread( void *data )
+{
+    playlist_preparser_t *p_preparser = data;
+    playlist_t *p_playlist = p_preparser->p_playlist;
+
+    for( ;; )
+    {
+        input_item_t *p_current;
+
+        /* */
+        vlc_mutex_lock( &p_preparser->lock );
+        mutex_cleanup_push( &p_preparser->lock );
+
+        while( p_preparser->i_waiting == 0 )
+            vlc_cond_wait( &p_preparser->wait, &p_preparser->lock );
+
+        p_current = p_preparser->pp_waiting[0];
+        REMOVE_ELEM( p_preparser->pp_waiting, p_preparser->i_waiting, 0 );
+        vlc_cleanup_run( );
+
+        if( !p_current )
+            continue;
+
+        int canc = vlc_savecancel();
+
+        Preparse( p_playlist, p_current );
+
+        Art( p_preparser, p_current );
+
         vlc_restorecancel( canc );
 
+        /* */
         int i_activity = var_GetInteger( p_playlist, "activity" );
-        if( i_activity < 0 ) i_activity = 0;
+        if( i_activity < 0 )
+            i_activity = 0;
+
         /* Sleep at least 1ms */
         msleep( (i_activity+1) * 1000 );
     }

src/playlist/preparser.h

@@ -25,20 +25,33 @@
 #ifndef _PLAYLIST_PREPARSER_H
 #define _PLAYLIST_PREPARSER_H 1
 
-typedef struct
-{
-    playlist_t          *p_playlist;
-    playlist_fetcher_t  *p_fetcher;
-
-    vlc_thread_t    thread;
-    vlc_mutex_t     lock;
-    vlc_cond_t      wait;
-    input_item_t  **pp_waiting;
-    int             i_waiting;
-} playlist_preparser_t;
+/**
+ * Preparser opaque structure.
+ *
+ * The preparser object will retreive the meta data of any given input item in
+ * an asynchronious way.
+ * It will also issue art fetching requests.
+ */
+typedef struct playlist_preparser_t playlist_preparser_t;
 
+/**
+ * This function creates the preparser object and thread.
+ */
 playlist_preparser_t *playlist_preparser_New( playlist_t *, playlist_fetcher_t * );
+
+/**
+ * This function enqueues the provided item to be preparsed.
+ *
+ * The input item is retained until the preparsing is done or until the
+ * preparser object is deleted.
+ */
 void playlist_preparser_Push( playlist_preparser_t *, input_item_t * );
+
+/**
+ * This function destroy the preparser object and thread.
+ *
+ * All pending input items will be released.
+ */
 void playlist_preparser_Delete( playlist_preparser_t * );
 
 #endif