src/control/log.c

   1 /*****************************************************************************
   2  * log.c: libvlc new API log functions
   3  *****************************************************************************
   4  * Copyright (C) 2005 the VideoLAN team
   5  *
   6  * $Id$
   7  *
   8  * Authors: Damien Fouilleul <damienf@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
  25 #ifdef HAVE_CONFIG_H
  26 # include "config.h"
  27 #endif
  28
  29 #include "libvlc_internal.h"
  30 #include <vlc/libvlc.h>
  31 #include <assert.h>
  32
  33 /* This API is terminally broken.
  34  * First, it does not implement any kind of notification.
  35  * Second, the iterating scheme is hermetic to any kind of thread-safety
  36  * owing to its constant pointer constraints.
  37  *  -- Courmisch
  38  *
  39  * "If you break your leg, don't run to me for sympathy"
  40  *   -- some character, Beneath a Steel Sky
  41  */
  42
  43 struct msg_cb_data_t
  44 {
  45     vlc_spinlock_t lock;
  46     msg_item_t *items[VLC_MSG_QSIZE];
  47     unsigned    count;
  48     int         verbosity;
  49 };
  50
  51 static void handler( msg_cb_data_t *d, msg_item_t *p_item, unsigned i_drop )
  52 {
  53     if (p_item->i_type > d->verbosity)
  54         return;
  55
  56     vlc_spin_lock (&d->lock);
  57     if (d->count < VLC_MSG_QSIZE)
  58     {
  59         d->items[d->count++] = p_item;
  60         msg_Hold (p_item);
  61     }
  62     vlc_spin_unlock (&d->lock);
  63     (void)i_drop;
  64 }
  65
  66 struct libvlc_log_t
  67 {
  68     libvlc_instance_t  *p_instance;
  69     msg_subscription_t *p_messages;
  70     msg_cb_data_t       data;
  71 };
  72
  73 struct libvlc_log_iterator_t
  74 {
  75     msg_cb_data_t *p_data;
  76     unsigned i_pos;
  77     unsigned i_end;
  78 };
  79
  80 unsigned libvlc_get_log_verbosity( const libvlc_instance_t *p_instance )
  81 {
  82     assert( p_instance );
  83     return p_instance->verbosity;
  84 }
  85
  86 void libvlc_set_log_verbosity( libvlc_instance_t *p_instance, unsigned level )
  87 {
  88     assert( p_instance );
  89     p_instance->verbosity = level;
  90 }
  91
  92 libvlc_log_t *libvlc_log_open( libvlc_instance_t *p_instance, libvlc_exception_t *p_e )
  93 {
  94     struct libvlc_log_t *p_log =
  95         (struct libvlc_log_t *)malloc(sizeof(struct libvlc_log_t));
  96
  97     if( !p_log ) RAISENULL( "Out of memory" );
  98
  99     p_log->p_instance = p_instance;
 100     vlc_spin_init( &p_log->data.lock );
 101     p_log->data.count = 0;
 102     p_log->data.verbosity = p_instance->verbosity;
 103     p_log->p_messages = msg_Subscribe(p_instance->p_libvlc_int, handler, &p_log->data);
 104
 105     if( !p_log->p_messages )
 106     {
 107         free( p_log );
 108         RAISENULL( "Out of memory" );
 109     }
 110
 111     libvlc_retain( p_instance );
 112     return p_log;
 113 }
 114
 115 void libvlc_log_close( libvlc_log_t *p_log )
 116 {
 117     if( !p_log )
 118         return;
 119
 120     assert( p_log->p_messages );
 121     msg_Unsubscribe(p_log->p_messages);
 122     libvlc_release( p_log->p_instance );
 123     libvlc_log_clear( p_log );
 124     vlc_spin_destroy( &p_log->data.lock );
 125     free(p_log);
 126 }
 127
 128 unsigned libvlc_log_count( const libvlc_log_t *p_log )
 129 {
 130     if( !p_log )
 131         return 0;
 132
 133     msg_cb_data_t *data = &((libvlc_log_t *)p_log)->data;
 134     unsigned ret;
 135
 136     /* We cannot lock due to constant pointer constraints. Break them.
 137      * Even then, this si not really thread safe anyway. */
 138     vlc_spin_lock (&data->lock);
 139     ret = data->count;
 140     vlc_spin_unlock (&data->lock);
 141     return ret;
 142 }
 143
 144 void libvlc_log_clear( libvlc_log_t *p_log )
 145 {
 146     if( !p_log )
 147         return;
 148
 149     vlc_spin_lock (&p_log->data.lock);
 150     msg_item_t *tab[p_log->data.count];
 151     memcpy (tab, p_log->data.items, sizeof (tab));
 152     p_log->data.count = 0;
 153     vlc_spin_unlock (&p_log->data.lock);
 154
 155     for (unsigned i = 0; i < sizeof (tab) / sizeof (tab[0]); i++)
 156          msg_Release (tab[i]);
 157 }
 158
 159 libvlc_log_iterator_t *libvlc_log_get_iterator( const libvlc_log_t *p_log,
 160  libvlc_exception_t *p_e )
 161 {
 162     if( p_log )
 163     {
 164         struct libvlc_log_iterator_t *p_iter =
 165             (struct libvlc_log_iterator_t *)malloc(sizeof(struct libvlc_log_iterator_t));
 166         /* FIXME: break constant pointer constraints */
 167         msg_cb_data_t *data = &((libvlc_log_t *)p_log)->data;
 168
 169         if( !p_iter ) RAISENULL( "Out of memory" );
 170
 171         vlc_spin_lock (&data->lock);
 172         p_iter->p_data  = data;
 173         p_iter->i_pos   = 0;
 174         p_iter->i_end   = data->count;
 175         vlc_spin_unlock (&data->lock);
 176
 177         return p_iter;
 178     }
 179     RAISENULL("Invalid log object!");
 180 }
 181
 182 void libvlc_log_iterator_free( libvlc_log_iterator_t *p_iter )
 183 {
 184     free( p_iter );
 185 }
 186
 187 int libvlc_log_iterator_has_next( const libvlc_log_iterator_t *p_iter )
 188 {
 189     if( !p_iter )
 190         return 0;
 191     return p_iter->i_pos != p_iter->i_end;
 192 }
 193
 194 libvlc_log_message_t *libvlc_log_iterator_next( libvlc_log_iterator_t *p_iter,
 195                                                 libvlc_log_message_t *buffer,
 196                                                 libvlc_exception_t *p_e )
 197 {
 198     unsigned i_pos;
 199
 200     if( !p_iter )
 201         return NULL;
 202     assert( buffer );
 203
 204     i_pos = p_iter->i_pos;
 205     if( i_pos != p_iter->i_end )
 206     {
 207         msg_item_t *msg;
 208         vlc_spin_lock (&p_iter->p_data->lock);
 209         msg = p_iter->p_data->items[i_pos];
 210         buffer->i_severity  = msg->i_type;
 211         buffer->psz_type    = msg->psz_object_type;
 212         buffer->psz_name    = msg->psz_module;
 213         buffer->psz_header  = msg->psz_header;
 214         buffer->psz_message = msg->psz_msg;
 215         vlc_spin_unlock (&p_iter->p_data->lock);
 216         p_iter->i_pos++;
 217
 218         return buffer;
 219     }
 220     RAISENULL("No more messages");
 221 }