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 )
  93 {
  94     struct libvlc_log_t *p_log = malloc(sizeof(*p_log));
  95     if (unlikely(p_log == NULL))
  96     {
  97         libvlc_printerr ("Not enough memory");
  98         return NULL;
  99     }
 100
 101     p_log->p_instance = p_instance;
 102     vlc_spin_init( &p_log->data.lock );
 103     p_log->data.count = 0;
 104     p_log->data.verbosity = p_instance->verbosity;
 105     p_log->p_messages = msg_Subscribe(p_instance->p_libvlc_int, handler, &p_log->data);
 106
 107     if( !p_log->p_messages )
 108     {
 109         free( p_log );
 110         libvlc_printerr ("Not enough memory");
 111         return NULL;
 112     }
 113
 114     libvlc_retain( p_instance );
 115     return p_log;
 116 }
 117
 118 void libvlc_log_close( libvlc_log_t *p_log )
 119 {
 120     if( !p_log )
 121         return;
 122
 123     assert( p_log->p_messages );
 124     msg_Unsubscribe(p_log->p_messages);
 125     libvlc_release( p_log->p_instance );
 126     libvlc_log_clear( p_log );
 127     vlc_spin_destroy( &p_log->data.lock );
 128     free(p_log);
 129 }
 130
 131 unsigned libvlc_log_count( const libvlc_log_t *p_log )
 132 {
 133     if( !p_log )
 134         return 0;
 135
 136     msg_cb_data_t *data = &((libvlc_log_t *)p_log)->data;
 137     unsigned ret;
 138
 139     /* We cannot lock due to constant pointer constraints. Break them.
 140      * Even then, this si not really thread safe anyway. */
 141     vlc_spin_lock (&data->lock);
 142     ret = data->count;
 143     vlc_spin_unlock (&data->lock);
 144     return ret;
 145 }
 146
 147 void libvlc_log_clear( libvlc_log_t *p_log )
 148 {
 149     if( !p_log )
 150         return;
 151
 152     vlc_spin_lock (&p_log->data.lock);
 153     msg_item_t *tab[p_log->data.count];
 154     memcpy (tab, p_log->data.items, sizeof (tab));
 155     p_log->data.count = 0;
 156     vlc_spin_unlock (&p_log->data.lock);
 157
 158     for (unsigned i = 0; i < sizeof (tab) / sizeof (tab[0]); i++)
 159          msg_Release (tab[i]);
 160 }
 161
 162 libvlc_log_iterator_t *libvlc_log_get_iterator( const libvlc_log_t *p_log )
 163 {
 164     if (p_log == NULL)
 165         return NULL;
 166
 167     struct libvlc_log_iterator_t *p_iter = malloc (sizeof (*p_iter));
 168     if (unlikely(p_iter == NULL))
 169     {
 170         libvlc_printerr ("Not enough memory");
 171         return NULL;
 172     }
 173
 174     /* FIXME: break constant pointer constraints */
 175     msg_cb_data_t *data = &((libvlc_log_t *)p_log)->data;
 176
 177     vlc_spin_lock (&data->lock);
 178     p_iter->p_data  = data;
 179     p_iter->i_pos   = 0;
 180     p_iter->i_end   = data->count;
 181     vlc_spin_unlock (&data->lock);
 182     return p_iter;
 183 }
 184
 185 void libvlc_log_iterator_free( libvlc_log_iterator_t *p_iter )
 186 {
 187     free( p_iter );
 188 }
 189
 190 int libvlc_log_iterator_has_next( const libvlc_log_iterator_t *p_iter )
 191 {
 192     if( !p_iter )
 193         return 0;
 194     return p_iter->i_pos != p_iter->i_end;
 195 }
 196
 197 libvlc_log_message_t *libvlc_log_iterator_next( libvlc_log_iterator_t *p_iter,
 198                                                 libvlc_log_message_t *buffer )
 199 {
 200     unsigned i_pos;
 201
 202     if( !p_iter )
 203         return NULL;
 204     assert (buffer != NULL);
 205
 206     i_pos = p_iter->i_pos;
 207     if( i_pos != p_iter->i_end )
 208     {
 209         msg_item_t *msg;
 210         vlc_spin_lock (&p_iter->p_data->lock);
 211         msg = p_iter->p_data->items[i_pos];
 212         buffer->i_severity  = msg->i_type;
 213         buffer->psz_type    = msg->psz_object_type;
 214         buffer->psz_name    = msg->psz_module;
 215         buffer->psz_header  = msg->psz_header;
 216         buffer->psz_message = msg->psz_msg;
 217         vlc_spin_unlock (&p_iter->p_data->lock);
 218         p_iter->i_pos++;
 219
 220         return buffer;
 221     }
 222     return NULL;
 223 }