[vlc-devel] [PATCH 2/2] preparser: add an option to force preparsing

Rémi Denis-Courmont remi at remlab.net
Thu Mar 19 18:23:05 CET 2015


Le jeudi 19 mars 2015, 18:06:29 Thomas Guillem a écrit :
> When a preparse request comes from the user, ie from playlist_AddInput or

"i.e."

> from libvlc_MetaRequest, force the preparsing of the item regardless of its
> type.

How does that affect capture devices or HTTP URLs? We really really don´t want 
to *pre*parse any of those. For hardware, preparsing would cause spurious 
errors with concurrent access, etc. For non-FS network resources, access might 
not be idempotent, and even for FS resources ones, preparsing may cause 
undesirable traffic.

> ---
>  src/libvlc.c             |  2 +-
>  src/playlist/item.c      | 11 ++++++-----
>  src/playlist/preparser.c | 42 +++++++++++++++++++++++++++++++++---------
>  src/playlist/preparser.h |  3 ++-
>  4 files changed, 42 insertions(+), 16 deletions(-)
> 
> diff --git a/src/libvlc.c b/src/libvlc.c
> index cff3784..2d85972 100644
> --- a/src/libvlc.c
> +++ b/src/libvlc.c
> @@ -608,7 +608,7 @@ int libvlc_MetaRequest(libvlc_int_t *libvlc,
> input_item_t *item, if (unlikely(priv->parser == NULL))
>          return VLC_ENOMEM;
> 
> -    playlist_preparser_Push(priv->parser, item, i_options);
> +    playlist_preparser_Push(priv->parser, item, i_options, true);
>      return VLC_SUCCESS;
>  }
> 
> diff --git a/src/playlist/item.c b/src/playlist/item.c
> index 5ce59f3..1780dd7 100644
> --- a/src/playlist/item.c
> +++ b/src/playlist/item.c
> @@ -34,7 +34,7 @@
>  static void AddItem( playlist_t *p_playlist, playlist_item_t *p_item,
>                       playlist_item_t *p_node, int i_mode, int i_pos );
>  static void GoAndPreparse( playlist_t *p_playlist, int i_mode,
> -                           playlist_item_t * );
> +                           playlist_item_t *, bool );
>  static void ChangeToNode( playlist_t *p_playlist, playlist_item_t *p_item
> );
> 
>  static int RecursiveAddIntoParent (
> @@ -462,7 +462,7 @@ int playlist_AddInput( playlist_t* p_playlist,
> input_item_t *p_input, b_playlist ? p_playlist->p_playing :
>                            p_playlist->p_media_library , i_mode, i_pos );
> 
> -    GoAndPreparse( p_playlist, i_mode, p_item );
> +    GoAndPreparse( p_playlist, i_mode, p_item, true );
> 
>      PL_UNLOCK_IF( !b_locked );
>      return VLC_SUCCESS;
> @@ -498,7 +498,7 @@ playlist_item_t * playlist_NodeAddInput( playlist_t
> *p_playlist, goto end;
>      AddItem( p_playlist, p_item, p_parent, i_mode, i_pos );
> 
> -    GoAndPreparse( p_playlist, i_mode, p_item );
> +    GoAndPreparse( p_playlist, i_mode, p_item, false );
> 
>  end:
>      PL_UNLOCK_IF( !b_locked );
> @@ -744,7 +744,7 @@ mtime_t playlist_GetNodeDuration( playlist_item_t* node
> )
> 
>  /* Enqueue an item for preparsing, and play it, if needed */
>  static void GoAndPreparse( playlist_t *p_playlist, int i_mode,
> -                           playlist_item_t *p_item )
> +                           playlist_item_t *p_item, bool b_user_request )
>  {
>      playlist_private_t *sys = pl_priv(p_playlist);
> 
> @@ -765,7 +765,8 @@ static void GoAndPreparse( playlist_t *p_playlist, int
> i_mode, char *psz_album = input_item_GetAlbum( p_item->p_input );
>      if( sys->p_preparser != NULL && !input_item_IsPreparsed(
> p_item->p_input ) && (EMPTY_STR(psz_artist) || EMPTY_STR(psz_album)) )
> -        playlist_preparser_Push( sys->p_preparser, p_item->p_input, 0 );
> +        playlist_preparser_Push( sys->p_preparser, p_item->p_input, 0,
> +                                 b_user_request );
>      free( psz_artist );
>      free( psz_album );
>  }
> diff --git a/src/playlist/preparser.c b/src/playlist/preparser.c
> index 2d3887d..fd25d66 100644
> --- a/src/playlist/preparser.c
> +++ b/src/playlist/preparser.c
> @@ -34,6 +34,14 @@
>  /**************************************************************************
> *** * Structures/definitions
>  
> ***************************************************************************
> **/ +typedef struct preparser_entry_t preparser_entry_t;
> +
> +struct preparser_entry_t
> +{
> +    input_item_t    *p_item;
> +    bool            b_user_request;
> +};
> +
>  struct playlist_preparser_t
>  {
>      vlc_object_t        *object;
> @@ -42,7 +50,7 @@ struct playlist_preparser_t
>      vlc_mutex_t     lock;
>      vlc_cond_t      wait;
>      bool            b_live;
> -    input_item_t  **pp_waiting;
> +    preparser_entry_t **pp_waiting;
>      int             i_waiting;
>  };
> 
> @@ -72,14 +80,21 @@ playlist_preparser_t *playlist_preparser_New(
> vlc_object_t *parent ) }
> 
>  void playlist_preparser_Push( playlist_preparser_t *p_preparser,
> input_item_t *p_item, -                             
> input_item_meta_request_option_t i_options ) +                             
> input_item_meta_request_option_t i_options, +                             
> bool b_user_request )
>  {
> -    vlc_gc_incref( p_item );
>      VLC_UNUSED( i_options );
> +    preparser_entry_t *p_entry = malloc( sizeof(preparser_entry_t) );
> +
> +    if ( !p_entry )
> +        return;
> +    p_entry->p_item = p_item;
> +    p_entry->b_user_request = b_user_request;
> +    vlc_gc_incref( p_entry->p_item );
> 
>      vlc_mutex_lock( &p_preparser->lock );
>      INSERT_ELEM( p_preparser->pp_waiting, p_preparser->i_waiting,
> -                 p_preparser->i_waiting, p_item );
> +                 p_preparser->i_waiting, p_entry );
>      if( !p_preparser->b_live )
>      {
>          if( vlc_clone_detach( NULL, Thread, p_preparser,
> @@ -104,7 +119,9 @@ void playlist_preparser_Delete( playlist_preparser_t
> *p_preparser ) /* Remove pending item to speed up preparser thread exit */
>      while( p_preparser->i_waiting > 0 )
>      {
> -        vlc_gc_decref( p_preparser->pp_waiting[0] );
> +        preparser_entry_t *p_entry = p_preparser->pp_waiting[0];
> +        vlc_gc_decref( p_entry->p_item );
> +        free( p_entry );
>          REMOVE_ELEM( p_preparser->pp_waiting, p_preparser->i_waiting, 0 );
>      }
> 
> @@ -127,13 +144,16 @@ void playlist_preparser_Delete( playlist_preparser_t
> *p_preparser ) /**
>   * This function preparses an item when needed.
>   */
> -static void Preparse( vlc_object_t *obj, input_item_t *p_item )
> +static void Preparse( vlc_object_t *obj, input_item_t *p_item,
> +                      bool b_user_request )
>  {
>      vlc_mutex_lock( &p_item->lock );
>      int i_type = p_item->i_type;
>      vlc_mutex_unlock( &p_item->lock );
> 
> -    if( i_type != ITEM_TYPE_FILE )
> +    /* if the request comes from an user, preparse the item regardless of
> its +     * type */
> +    if( !b_user_request && i_type != ITEM_TYPE_FILE )
>      {
>          input_item_SetPreparsed( p_item, true );
>          input_item_SignalPreparseEnded( p_item );
> @@ -203,12 +223,16 @@ static void *Thread( void *data )
>      for( ;; )
>      {
>          input_item_t *p_current;
> +        bool b_user_request;
> 
>          /* */
>          vlc_mutex_lock( &p_preparser->lock );
>          if( p_preparser->i_waiting > 0 )
>          {
> -            p_current = p_preparser->pp_waiting[0];
> +            preparser_entry_t *p_entry = p_preparser->pp_waiting[0];
> +            p_current = p_entry->p_item;
> +            b_user_request = p_entry->b_user_request;
> +            free( p_entry );
>              REMOVE_ELEM( p_preparser->pp_waiting, p_preparser->i_waiting, 0
> ); }
>          else
> @@ -222,7 +246,7 @@ static void *Thread( void *data )
>          if( !p_current )
>              break;
> 
> -        Preparse( obj, p_current );
> +        Preparse( obj, p_current, b_user_request );
> 
>          Art( p_preparser, p_current );
>          vlc_gc_decref(p_current);
> diff --git a/src/playlist/preparser.h b/src/playlist/preparser.h
> index 2b28863..1eea8d5 100644
> --- a/src/playlist/preparser.h
> +++ b/src/playlist/preparser.h
> @@ -49,7 +49,8 @@ playlist_preparser_t *playlist_preparser_New( vlc_object_t
> * ); * preparsed.
>   */
>  void playlist_preparser_Push( playlist_preparser_t *, input_item_t *,
> -                              input_item_meta_request_option_t );
> +                              input_item_meta_request_option_t,
> +                              bool );
> 
>  void playlist_preparser_fetcher_Push( playlist_preparser_t *, input_item_t
> *, input_item_meta_request_option_t );

-- 
Rémi Denis-Courmont
http://www.remlab.net/




More information about the vlc-devel mailing list