1 /* GStreamer

     2  * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>

     3  *                    2000 Wim Taymans <wtay@chello.be>

     4  *

     5  * gstplugin.c: Plugin subsystem for loading elements, types, and libs

     6  *

     7  * This library is free software; you can redistribute it and/or

     8  * modify it under the terms of the GNU Library General Public

     9  * License as published by the Free Software Foundation; either

    10  * version 2 of the License, or (at your option) any later version.

    11  *

    12  * This library is distributed in the hope that it will be useful,

    13  * but WITHOUT ANY WARRANTY; without even the implied warranty of

    14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    15  * Library General Public License for more details.

    16  *

    17  * You should have received a copy of the GNU Library General Public

    18  * License along with this library; if not, write to the

    19  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,

    20  * Boston, MA 02111-1307, USA.

    21  */

    22 

    23 /**

    24  * SECTION:gstplugin

    25  * @short_description: Container for features loaded from a shared object module

    26  * @see_also: #GstPluginFeature, #GstElementFactory

    27  *

    28  * GStreamer is extensible, so #GstElement instances can be loaded at runtime.

    29  * A plugin system can provide one or more of the basic

    30  * <application>GStreamer</application> #GstPluginFeature subclasses.

    31  *

    32  * A plugin should export a symbol <symbol>gst_plugin_desc</symbol> that is a

    33  * struct of type #GstPluginDesc.

    34  * the plugin loader will check the version of the core library the plugin was

    35  * linked against and will create a new #GstPlugin. It will then call the

    36  * #GstPluginInitFunc function that was provided in the

    37  * <symbol>gst_plugin_desc</symbol>.

    38  *

    39  * Once you have a handle to a #GstPlugin (e.g. from the #GstRegistryPool), you

    40  * can add any object that subclasses #GstPluginFeature.

    41  *

    42  * Use gst_plugin_find_feature() and gst_plugin_get_feature_list() to find

    43  * features in a plugin.

    44  *

    45  * Usually plugins are always automaticlly loaded so you don't need to call

    46  * gst_plugin_load() explicitly to bring it into memory. There are options to

    47  * statically link plugins to an app or even use GStreamer without a plugin

    48  * repository in which case gst_plugin_load() can be needed to bring the plugin

    49  * into memory.

    50  */

    51 

    52 #ifdef HAVE_CONFIG_H

    53 #include "config.h"

    54 #endif

    55 #include <glib/gstdio.h>

    56 #include <sys/types.h>

    57 #ifdef HAVE_DIRENT_H

    58 #include <dirent.h>

    59 #endif

    60 #ifdef HAVE_UNISTD_H

    61 #include <unistd.h>

    62 #endif

    63 #include <signal.h>

    64 #include <errno.h>

    65 

    66 #include "gst_private.h"

    67 #include "glib-compat-private.h"

    68 

    69 #include <gst/gst.h>

    70 

    71 #ifdef __SYMBIAN32__

    72 #include <glib_global.h>

    73 #endif

    74 

    75 #define GST_CAT_DEFAULT GST_CAT_PLUGIN_LOADING

    76 

    77 static guint _num_static_plugins;       /* 0    */

    78 static GstPluginDesc *_static_plugins;  /* NULL */

    79 static gboolean _gst_plugin_inited;

    80 

    81 /* static variables for segfault handling of plugin loading */

    82 static char *_gst_plugin_fault_handler_filename = NULL;

    83 

    84 #ifndef HAVE_WIN32

    85 static gboolean _gst_plugin_fault_handler_is_setup = FALSE;

    86 #endif

    87 

    88 /* list of valid licenses.

    89  * One of these must be specified or the plugin won't be loaded

    90  * Contact gstreamer-devel@lists.sourceforge.net if your license should be

    91  * added.

    92  *

    93  * GPL: http://www.gnu.org/copyleft/gpl.html

    94  * LGPL: http://www.gnu.org/copyleft/lesser.html

    95  * QPL: http://www.trolltech.com/licenses/qpl.html

    96  * MPL: http://www.opensource.org/licenses/mozilla1.1.php

    97  * MIT/X11: http://www.opensource.org/licenses/mit-license.php

    98  * 3-clause BSD: http://www.opensource.org/licenses/bsd-license.php

    99  */

   100 static const gchar *valid_licenses[] = {

   101   "LGPL",                       /* GNU Lesser General Public License */

   102   "GPL",                        /* GNU General Public License */

   103   "QPL",                        /* Trolltech Qt Public License */

   104   "GPL/QPL",                    /* Combi-license of GPL + QPL */

   105   "MPL",                        /* MPL 1.1 license */

   106   "BSD",                        /* 3-clause BSD license */

   107   "MIT/X11",                    /* MIT/X11 license */

   108   "Proprietary",                /* Proprietary license */

   109   GST_LICENSE_UNKNOWN,          /* some other license */

   110   NULL

   111 };

   112 

   113 static GstPlugin *gst_plugin_register_func (GstPlugin * plugin,

   114     const GstPluginDesc * desc);

   115 static void gst_plugin_desc_copy (GstPluginDesc * dest,

   116     const GstPluginDesc * src);

   117 static void gst_plugin_desc_free (GstPluginDesc * desc);

   118 

   119 

   120 G_DEFINE_TYPE (GstPlugin, gst_plugin, GST_TYPE_OBJECT);

   121 

   122 static void

   123 gst_plugin_init (GstPlugin * plugin)

   124 {

   125   /* do nothing, needed because of G_DEFINE_TYPE */

   126 }

   127 

   128 static void

   129 gst_plugin_finalize (GObject * object)

   130 {

   131   GstPlugin *plugin = GST_PLUGIN_CAST (object);

   132   GstRegistry *registry = gst_registry_get_default ();

   133   GList *g;

   134 

   135   GST_DEBUG ("finalizing plugin %p", plugin);

   136   for (g = registry->plugins; g; g = g->next) {

   137     if (g->data == (gpointer) plugin) {

   138       g_warning ("removing plugin that is still in registry");

   139     }

   140   }

   141   g_free (plugin->filename);

   142   g_free (plugin->basename);

   143   gst_plugin_desc_free (&plugin->desc);

   144 

   145   G_OBJECT_CLASS (gst_plugin_parent_class)->finalize (object);

   146 }

   147 

   148 static void

   149 gst_plugin_class_init (GstPluginClass * klass)

   150 {

   151   G_OBJECT_CLASS (klass)->finalize = GST_DEBUG_FUNCPTR (gst_plugin_finalize);

   152 }

   153 #ifdef __SYMBIAN32__

   154 EXPORT_C

   155 #endif

   156 

   157 

   158 GQuark

   159 gst_plugin_error_quark (void)

   160 {

   161   static GQuark quark = 0;

   162 

   163   if (!quark)

   164     quark = g_quark_from_static_string ("gst_plugin_error");

   165   return quark;

   166 }

   167 

   168 #ifndef GST_REMOVE_DEPRECATED

   169 /* this function can be called in the GCC constructor extension, before

   170  * the _gst_plugin_initialize() was called. In that case, we store the

   171  * plugin description in a list to initialize it when we open the main

   172  * module later on.

   173  * When the main module is known, we can register the plugin right away.

   174  */

   175 #ifdef __SYMBIAN32__

   176 EXPORT_C

   177 #endif

   178 

   179 void

   180 _gst_plugin_register_static (GstPluginDesc * desc)

   181 {

   182   g_return_if_fail (desc != NULL);

   183 

   184   if (!_gst_plugin_inited) {

   185     /* We can't use any GLib functions here, since g_thread_init hasn't been

   186      * called yet, and we can't call it here either, or programs that don't

   187      * guard their g_thread_init calls in main() will just abort */

   188     ++_num_static_plugins;

   189     _static_plugins =

   190         realloc (_static_plugins, _num_static_plugins * sizeof (GstPluginDesc));

   191     /* assume strings in the GstPluginDesc are static const or live forever */

   192     _static_plugins[_num_static_plugins - 1] = *desc;

   193   } else {

   194     gst_plugin_register_static (desc->major_version, desc->minor_version,

   195         desc->name, desc->description, desc->plugin_init, desc->version,

   196         desc->license, desc->source, desc->package, desc->origin);

   197   }

   198 }

   199 #endif

   200 

   201 /**

   202  * gst_plugin_register_static:

   203  * @major_version: the major version number of the GStreamer core that the

   204  *     plugin was compiled for, you can just use GST_VERSION_MAJOR here

   205  * @minor_version: the minor version number of the GStreamer core that the

   206  *     plugin was compiled for, you can just use GST_VERSION_MINOR here

   207  * @name: a unique name of the plugin (ideally prefixed with an application- or

   208  *     library-specific namespace prefix in order to avoid name conflicts in

   209  *     case a similar plugin with the same name ever gets added to GStreamer)

   210  * @description: description of the plugin

   211  * @init_func: pointer to the init function of this plugin.

   212  * @version: version string of the plugin

   213  * @license: effective license of plugin. Must be one of the approved licenses

   214  *     (see #GstPluginDesc above) or the plugin will not be registered.

   215  * @source: source module plugin belongs to

   216  * @package: shipped package plugin belongs to

   217  * @origin: URL to provider of plugin

   218  *

   219  * Registers a static plugin, ie. a plugin which is private to an application

   220  * or library and contained within the application or library (as opposed to

   221  * being shipped as a separate module file).

   222  *

   223  * You must make sure that GStreamer has been initialised (with gst_init() or

   224  * via gst_init_get_option_group()) before calling this function.

   225  *

   226  * Returns: TRUE if the plugin was registered correctly, otherwise FALSE.

   227  *

   228  * Since: 0.10.16

   229  */

   230 #ifdef __SYMBIAN32__

   231 EXPORT_C

   232 #endif

   233 

   234 gboolean

   235 gst_plugin_register_static (gint major_version, gint minor_version,

   236     const gchar * name, gchar * description, GstPluginInitFunc init_func,

   237     const gchar * version, const gchar * license, const gchar * source,

   238     const gchar * package, const gchar * origin)

   239 {

   240 #ifdef __SYMBIAN32__

   241   GstPluginDesc desc;

   242   GstPlugin *plugin;

   243   gboolean res = FALSE;

   244 

   245   desc.major_version = major_version;

   246   desc.minor_version = minor_version;

   247   desc.name = name;

   248   desc.description = description;

   249   desc.plugin_init = init_func;

   250   desc.version = version;

   251   desc.license = license;

   252   desc.source = source;

   253   desc.package = package;

   254   desc.origin = origin;

   255 #else

   256   GstPluginDesc desc = { major_version, minor_version, name, description,

   257     init_func, version, license, source, package, origin,

   258   };

   259   GstPlugin *plugin;

   260   gboolean res = FALSE;

   261 #endif

   262 

   263   g_return_val_if_fail (name != NULL, FALSE);

   264   g_return_val_if_fail (description != NULL, FALSE);

   265   g_return_val_if_fail (init_func != NULL, FALSE);

   266   g_return_val_if_fail (version != NULL, FALSE);

   267   g_return_val_if_fail (license != NULL, FALSE);

   268   g_return_val_if_fail (source != NULL, FALSE);

   269   g_return_val_if_fail (package != NULL, FALSE);

   270   g_return_val_if_fail (origin != NULL, FALSE);

   271 

   272   /* make sure gst_init() has been called */

   273   g_return_val_if_fail (_gst_plugin_inited != FALSE, FALSE);

   274 

   275   GST_LOG ("attempting to load static plugin \"%s\" now...", name);

   276   plugin = g_object_new (GST_TYPE_PLUGIN, NULL);

   277   if (gst_plugin_register_func (plugin, &desc) != NULL) {

   278     GST_INFO ("registered static plugin \"%s\"", name);

   279     res = gst_default_registry_add_plugin (plugin);

   280     GST_INFO ("added static plugin \"%s\", result: %d", name, res);

   281   }

   282   return res;

   283 }

   284 #ifdef __SYMBIAN32__

   285 EXPORT_C

   286 #endif

   287 

   288 

   289 void

   290 _gst_plugin_initialize (void)

   291 {

   292   guint i;

   293 

   294   _gst_plugin_inited = TRUE;

   295 

   296   /* now register all static plugins */

   297   GST_INFO ("registering %u static plugins", _num_static_plugins);

   298   for (i = 0; i < _num_static_plugins; ++i) {

   299     gst_plugin_register_static (_static_plugins[i].major_version,

   300         _static_plugins[i].minor_version, _static_plugins[i].name,

   301         _static_plugins[i].description, _static_plugins[i].plugin_init,

   302         _static_plugins[i].version, _static_plugins[i].license,

   303         _static_plugins[i].source, _static_plugins[i].package,

   304         _static_plugins[i].origin);

   305   }

   306 

   307   if (_static_plugins) {

   308     free (_static_plugins);

   309     _static_plugins = NULL;

   310     _num_static_plugins = 0;

   311   }

   312 }

   313 

   314 /* this function could be extended to check if the plugin license matches the

   315  * applications license (would require the app to register its license somehow).

   316  * We'll wait for someone who's interested in it to code it :)

   317  */

   318 static gboolean

   319 gst_plugin_check_license (const gchar * license)

   320 {

   321   const gchar **check_license = valid_licenses;

   322 

   323   g_assert (check_license);

   324 

   325   while (*check_license) {

   326     if (strcmp (license, *check_license) == 0)

   327       return TRUE;

   328     check_license++;

   329   }

   330   return FALSE;

   331 }

   332 

   333 static gboolean

   334 gst_plugin_check_version (gint major, gint minor)

   335 {

   336   /* return NULL if the major and minor version numbers are not compatible */

   337   /* with ours. */

   338   if (major != GST_VERSION_MAJOR || minor != GST_VERSION_MINOR)

   339     return FALSE;

   340 

   341   return TRUE;

   342 }

   343 

   344 static GstPlugin *

   345 gst_plugin_register_func (GstPlugin * plugin, const GstPluginDesc * desc)

   346 {

   347   if (!gst_plugin_check_version (desc->major_version, desc->minor_version)) {

   348     if (GST_CAT_DEFAULT)

   349       GST_WARNING ("plugin \"%s\" has incompatible version, not loading",

   350           plugin->filename);

   351     return NULL;

   352   }

   353 

   354   if (!desc->license || !desc->description || !desc->source ||

   355       !desc->package || !desc->origin) {

   356     if (GST_CAT_DEFAULT)

   357       GST_WARNING ("plugin \"%s\" has incorrect GstPluginDesc, not loading",

   358           plugin->filename);

   359     return NULL;

   360   }

   361 

   362   if (!gst_plugin_check_license (desc->license)) {

   363     if (GST_CAT_DEFAULT)

   364       GST_WARNING ("plugin \"%s\" has invalid license \"%s\", not loading",

   365           plugin->filename, desc->license);

   366     return NULL;

   367   }

   368 

   369   if (GST_CAT_DEFAULT)

   370     GST_LOG ("plugin \"%s\" looks good", GST_STR_NULL (plugin->filename));

   371 

   372   gst_plugin_desc_copy (&plugin->desc, desc);

   373 

   374   if (!((desc->plugin_init) (plugin))) {

   375     if (GST_CAT_DEFAULT)

   376       GST_WARNING ("plugin \"%s\" failed to initialise", plugin->filename);

   377     plugin->module = NULL;

   378     return NULL;

   379   }

   380 

   381   if (GST_CAT_DEFAULT)

   382     GST_LOG ("plugin \"%s\" initialised", GST_STR_NULL (plugin->filename));

   383 

   384   return plugin;

   385 }

   386 

   387 #ifdef HAVE_SIGACTION

   388 static struct sigaction oldaction;

   389 

   390 /*

   391  * _gst_plugin_fault_handler_restore:

   392  * segfault handler restorer

   393  */

   394 static void

   395 _gst_plugin_fault_handler_restore (void)

   396 {

   397   if (!_gst_plugin_fault_handler_is_setup)

   398     return;

   399 

   400   _gst_plugin_fault_handler_is_setup = FALSE;

   401 

   402   sigaction (SIGSEGV, &oldaction, NULL);

   403 }

   404 

   405 /*

   406  * _gst_plugin_fault_handler_sighandler:

   407  * segfault handler implementation

   408  */

   409 static void

   410 _gst_plugin_fault_handler_sighandler (int signum)

   411 {

   412   /* We need to restore the fault handler or we'll keep getting it */

   413   _gst_plugin_fault_handler_restore ();

   414 

   415   switch (signum) {

   416     case SIGSEGV:

   417       g_print ("\nERROR: ");

   418       g_print ("Caught a segmentation fault while loading plugin file:\n");

   419       g_print ("%s\n\n", _gst_plugin_fault_handler_filename);

   420       g_print ("Please either:\n");

   421       g_print ("- remove it and restart.\n");

   422       g_print ("- run with --gst-disable-segtrap and debug.\n");

   423       exit (-1);

   424       break;

   425     default:

   426       g_print ("Caught unhandled signal on plugin loading\n");

   427       break;

   428   }

   429 }

   430 

   431 /*

   432  * _gst_plugin_fault_handler_setup:

   433  * sets up the segfault handler

   434  */

   435 static void

   436 _gst_plugin_fault_handler_setup (void)

   437 {

   438   struct sigaction action;

   439 

   440   /* if asked to leave segfaults alone, just return */

   441   if (!gst_segtrap_is_enabled ())

   442     return;

   443 

   444   if (_gst_plugin_fault_handler_is_setup)

   445     return;

   446 

   447   _gst_plugin_fault_handler_is_setup = TRUE;

   448 

   449   memset (&action, 0, sizeof (action));

   450   action.sa_handler = _gst_plugin_fault_handler_sighandler;

   451 

   452   sigaction (SIGSEGV, &action, &oldaction);

   453 }

   454 #else

   455 static void

   456 _gst_plugin_fault_handler_restore (void)

   457 {

   458 }

   459 

   460 static void

   461 _gst_plugin_fault_handler_setup (void)

   462 {

   463 }

   464 #endif

   465 

   466 static void _gst_plugin_fault_handler_setup ();

   467 

   468 static GStaticMutex gst_plugin_loading_mutex = G_STATIC_MUTEX_INIT;

   469 

   470 /**

   471  * gst_plugin_load_file:

   472  * @filename: the plugin filename to load

   473  * @error: pointer to a NULL-valued GError

   474  *

   475  * Loads the given plugin and refs it.  Caller needs to unref after use.

   476  *

   477  * Returns: a reference to the existing loaded GstPlugin, a reference to the

   478  * newly-loaded GstPlugin, or NULL if an error occurred.

   479  */

   480 #ifdef __SYMBIAN32__

   481 EXPORT_C

   482 #endif

   483 

   484 GstPlugin *

   485 gst_plugin_load_file (const gchar * filename, GError ** error)

   486 {

   487   GstPlugin *plugin;

   488   GModule *module;

   489   gboolean ret;

   490   gpointer ptr;

   491   struct stat file_status;

   492   GstRegistry *registry;

   493    #ifdef __SYMBIAN32__

   494    GstPluginDesc* (*fn)(void)=NULL;

   495    void *temp;

   496    

   497    #endif

   498 

   499   g_return_val_if_fail (filename != NULL, NULL);

   500 

   501   registry = gst_registry_get_default ();

   502   g_static_mutex_lock (&gst_plugin_loading_mutex);

   503 

   504   plugin = gst_registry_lookup (registry, filename);

   505   if (plugin) {

   506     if (plugin->module) {

   507       g_static_mutex_unlock (&gst_plugin_loading_mutex);

   508       return plugin;

   509     } else {

   510       gst_object_unref (plugin);

   511       plugin = NULL;

   512     }

   513   }

   514 

   515   GST_CAT_DEBUG (GST_CAT_PLUGIN_LOADING, "attempt to load plugin \"%s\"",

   516       filename);

   517 

   518   if (g_module_supported () == FALSE) {

   519     GST_CAT_DEBUG (GST_CAT_PLUGIN_LOADING, "module loading not supported");

   520     g_set_error (error,

   521         GST_PLUGIN_ERROR,

   522         GST_PLUGIN_ERROR_MODULE, "Dynamic loading not supported");

   523     goto return_error;

   524   }

   525 

   526   if (g_stat (filename, &file_status)) {

   527     GST_CAT_DEBUG (GST_CAT_PLUGIN_LOADING, "problem accessing file");

   528     g_set_error (error,

   529         GST_PLUGIN_ERROR,

   530         GST_PLUGIN_ERROR_MODULE, "Problem accessing file %s: %s", filename,

   531         g_strerror (errno));

   532     goto return_error;

   533   }

   534 

   535   module = g_module_open (filename, G_MODULE_BIND_LOCAL);

   536   if (module == NULL) {

   537     GST_CAT_WARNING (GST_CAT_PLUGIN_LOADING, "module_open failed: %s",

   538         g_module_error ());

   539     g_set_error (error,

   540         GST_PLUGIN_ERROR, GST_PLUGIN_ERROR_MODULE, "Opening module failed: %s",

   541         g_module_error ());

   542     /* If we failed to open the shared object, then it's probably because a

   543      * plugin is linked against the wrong libraries. Print out an easy-to-see

   544      * message in this case. */

   545     g_warning ("Failed to load plugin '%s': %s", filename, g_module_error ());

   546     goto return_error;

   547   }

   548 

   549   plugin = g_object_new (GST_TYPE_PLUGIN, NULL);

   550 

   551   plugin->module = module;

   552   plugin->filename = g_strdup (filename);

   553   plugin->basename = g_path_get_basename (filename);

   554   plugin->file_mtime = file_status.st_mtime;

   555   plugin->file_size = file_status.st_size;

   556 

   557 #ifdef __SYMBIAN32__

   558    ret = g_module_symbol (module, "1", &ptr);

   559 #else   

   560   ret = g_module_symbol (module, "gst_plugin_desc", &ptr);

   561 #endif   

   562   if (!ret) {

   563     GST_DEBUG ("Could not find plugin entry point in \"%s\"", filename);

   564     g_set_error (error,

   565         GST_PLUGIN_ERROR,

   566         GST_PLUGIN_ERROR_MODULE,

   567         "File \"%s\" is not a GStreamer plugin", filename);

   568     g_module_close (module);

   569     goto return_error;

   570   }

   571    #ifdef __SYMBIAN32__

   572    fn=ptr;

   573    temp=fn();

   574    plugin->orig_desc = (GstPluginDesc *) temp;

   575    #else

   576   plugin->orig_desc = (GstPluginDesc *) ptr;

   577    #endif

   578 

   579   GST_LOG ("Plugin %p for file \"%s\" prepared, calling entry function...",

   580       plugin, filename);

   581 

   582   /* this is where we load the actual .so, so let's trap SIGSEGV */

   583   _gst_plugin_fault_handler_setup ();

   584   _gst_plugin_fault_handler_filename = plugin->filename;

   585 

   586   GST_LOG ("Plugin %p for file \"%s\" prepared, registering...",

   587       plugin, filename);

   588 

   589   if (!gst_plugin_register_func (plugin, plugin->orig_desc)) {

   590     /* remove signal handler */

   591     _gst_plugin_fault_handler_restore ();

   592     GST_DEBUG ("gst_plugin_register_func failed for plugin \"%s\"", filename);

   593     /* plugin == NULL */

   594     g_set_error (error,

   595         GST_PLUGIN_ERROR,

   596         GST_PLUGIN_ERROR_MODULE,

   597         "File \"%s\" appears to be a GStreamer plugin, but it failed to initialize",

   598         filename);

   599     g_module_close (module);

   600     goto return_error;

   601   }

   602 

   603   /* remove signal handler */

   604   _gst_plugin_fault_handler_restore ();

   605   _gst_plugin_fault_handler_filename = NULL;

   606   GST_INFO ("plugin \"%s\" loaded", plugin->filename);

   607 

   608   gst_object_ref (plugin);

   609   gst_default_registry_add_plugin (plugin);

   610 

   611   g_static_mutex_unlock (&gst_plugin_loading_mutex);

   612   return plugin;

   613 

   614 return_error:

   615   {

   616     if (plugin)

   617       gst_object_unref (plugin);

   618     g_static_mutex_unlock (&gst_plugin_loading_mutex);

   619     return NULL;

   620   }

   621 }

   622 

   623 static void

   624 gst_plugin_desc_copy (GstPluginDesc * dest, const GstPluginDesc * src)

   625 {

   626   dest->major_version = src->major_version;

   627   dest->minor_version = src->minor_version;

   628   dest->name = g_intern_string (src->name);

   629   /* maybe intern the description too, just for convenience? */

   630   dest->description = g_strdup (src->description);

   631   dest->plugin_init = src->plugin_init;

   632   dest->version = g_intern_string (src->version);

   633   dest->license = g_intern_string (src->license);

   634   dest->source = g_intern_string (src->source);

   635   dest->package = g_intern_string (src->package);

   636   dest->origin = g_intern_string (src->origin);

   637 }

   638 

   639 /* unused */

   640 static void

   641 gst_plugin_desc_free (GstPluginDesc * desc)

   642 {

   643   g_free (desc->description);

   644   memset (desc, 0, sizeof (GstPluginDesc));

   645 }

   646 

   647 /**

   648  * gst_plugin_get_name:

   649  * @plugin: plugin to get the name of

   650  *

   651  * Get the short name of the plugin

   652  *

   653  * Returns: the name of the plugin

   654  */

   655 #ifdef __SYMBIAN32__

   656 EXPORT_C

   657 #endif

   658 

   659 const gchar *

   660 gst_plugin_get_name (GstPlugin * plugin)

   661 {

   662   g_return_val_if_fail (plugin != NULL, NULL);

   663 

   664   return plugin->desc.name;

   665 }

   666 

   667 /**

   668  * gst_plugin_get_description:

   669  * @plugin: plugin to get long name of

   670  *

   671  * Get the long descriptive name of the plugin

   672  *

   673  * Returns: the long name of the plugin

   674  */

   675 #ifdef __SYMBIAN32__

   676 EXPORT_C

   677 #endif

   678 

   679 G_CONST_RETURN gchar *

   680 gst_plugin_get_description (GstPlugin * plugin)

   681 {

   682   g_return_val_if_fail (plugin != NULL, NULL);

   683 

   684   return plugin->desc.description;

   685 }

   686 

   687 /**

   688  * gst_plugin_get_filename:

   689  * @plugin: plugin to get the filename of

   690  *

   691  * get the filename of the plugin

   692  *

   693  * Returns: the filename of the plugin

   694  */

   695 #ifdef __SYMBIAN32__

   696 EXPORT_C

   697 #endif

   698 

   699 G_CONST_RETURN gchar *

   700 gst_plugin_get_filename (GstPlugin * plugin)

   701 {

   702   g_return_val_if_fail (plugin != NULL, NULL);

   703 

   704   return plugin->filename;

   705 }

   706 

   707 /**

   708  * gst_plugin_get_version:

   709  * @plugin: plugin to get the version of

   710  *

   711  * get the version of the plugin

   712  *

   713  * Returns: the version of the plugin

   714  */

   715 #ifdef __SYMBIAN32__

   716 EXPORT_C

   717 #endif

   718 

   719 G_CONST_RETURN gchar *

   720 gst_plugin_get_version (GstPlugin * plugin)

   721 {

   722   g_return_val_if_fail (plugin != NULL, NULL);

   723 

   724   return plugin->desc.version;

   725 }

   726 

   727 /**

   728  * gst_plugin_get_license:

   729  * @plugin: plugin to get the license of

   730  *

   731  * get the license of the plugin

   732  *

   733  * Returns: the license of the plugin

   734  */

   735 #ifdef __SYMBIAN32__

   736 EXPORT_C

   737 #endif

   738 

   739 G_CONST_RETURN gchar *

   740 gst_plugin_get_license (GstPlugin * plugin)

   741 {

   742   g_return_val_if_fail (plugin != NULL, NULL);

   743 

   744   return plugin->desc.license;

   745 }

   746 

   747 /**

   748  * gst_plugin_get_source:

   749  * @plugin: plugin to get the source of

   750  *

   751  * get the source module the plugin belongs to.

   752  *

   753  * Returns: the source of the plugin

   754  */

   755 #ifdef __SYMBIAN32__

   756 EXPORT_C

   757 #endif

   758 

   759 G_CONST_RETURN gchar *

   760 gst_plugin_get_source (GstPlugin * plugin)

   761 {

   762   g_return_val_if_fail (plugin != NULL, NULL);

   763 

   764   return plugin->desc.source;

   765 }

   766 

   767 /**

   768  * gst_plugin_get_package:

   769  * @plugin: plugin to get the package of

   770  *

   771  * get the package the plugin belongs to.

   772  *

   773  * Returns: the package of the plugin

   774  */

   775 #ifdef __SYMBIAN32__

   776 EXPORT_C

   777 #endif

   778 

   779 G_CONST_RETURN gchar *

   780 gst_plugin_get_package (GstPlugin * plugin)

   781 {

   782   g_return_val_if_fail (plugin != NULL, NULL);

   783 

   784   return plugin->desc.package;

   785 }

   786 

   787 /**

   788  * gst_plugin_get_origin:

   789  * @plugin: plugin to get the origin of

   790  *

   791  * get the URL where the plugin comes from

   792  *

   793  * Returns: the origin of the plugin

   794  */

   795 #ifdef __SYMBIAN32__

   796 EXPORT_C

   797 #endif

   798 

   799 G_CONST_RETURN gchar *

   800 gst_plugin_get_origin (GstPlugin * plugin)

   801 {

   802   g_return_val_if_fail (plugin != NULL, NULL);

   803 

   804   return plugin->desc.origin;

   805 }

   806 

   807 /**

   808  * gst_plugin_get_module:

   809  * @plugin: plugin to query

   810  *

   811  * Gets the #GModule of the plugin. If the plugin isn't loaded yet, NULL is

   812  * returned.

   813  *

   814  * Returns: module belonging to the plugin or NULL if the plugin isn't

   815  *          loaded yet.

   816  */

   817 #ifdef __SYMBIAN32__

   818 EXPORT_C

   819 #endif

   820 

   821 GModule *

   822 gst_plugin_get_module (GstPlugin * plugin)

   823 {

   824   g_return_val_if_fail (plugin != NULL, NULL);

   825 

   826   return plugin->module;

   827 }

   828 

   829 /**

   830  * gst_plugin_is_loaded:

   831  * @plugin: plugin to query

   832  *

   833  * queries if the plugin is loaded into memory

   834  *

   835  * Returns: TRUE is loaded, FALSE otherwise

   836  */

   837 #ifdef __SYMBIAN32__

   838 EXPORT_C

   839 #endif

   840 

   841 gboolean

   842 gst_plugin_is_loaded (GstPlugin * plugin)

   843 {

   844   g_return_val_if_fail (plugin != NULL, FALSE);

   845 

   846   return (plugin->module != NULL || plugin->filename == NULL);

   847 }

   848 

   849 #if 0

   850 /**

   851  * gst_plugin_feature_list:

   852  * @plugin: plugin to query

   853  * @filter: the filter to use

   854  * @first: only return first match

   855  * @user_data: user data passed to the filter function

   856  *

   857  * Runs a filter against all plugin features and returns a GList with

   858  * the results. If the first flag is set, only the first match is

   859  * returned (as a list with a single object).

   860  *

   861  * Returns: a GList of features, g_list_free after use.

   862  */

   863 GList *

   864 gst_plugin_feature_filter (GstPlugin * plugin,

   865     GstPluginFeatureFilter filter, gboolean first, gpointer user_data)

   866 {

   867   GList *list;

   868   GList *g;

   869 

   870   list = gst_filter_run (plugin->features, (GstFilterFunc) filter, first,

   871       user_data);

   872   for (g = list; g; g = g->next) {

   873     gst_object_ref (plugin);

   874   }

   875 

   876   return list;

   877 }

   878 

   879 typedef struct

   880 {

   881   GstPluginFeatureFilter filter;

   882   gboolean first;

   883   gpointer user_data;

   884   GList *result;

   885 }

   886 FeatureFilterData;

   887 

   888 static gboolean

   889 _feature_filter (GstPlugin * plugin, gpointer user_data)

   890 {

   891   GList *result;

   892   FeatureFilterData *data = (FeatureFilterData *) user_data;

   893 

   894   result = gst_plugin_feature_filter (plugin, data->filter, data->first,

   895       data->user_data);

   896   if (result) {

   897     data->result = g_list_concat (data->result, result);

   898     return TRUE;

   899   }

   900   return FALSE;

   901 }

   902 

   903 /**

   904  * gst_plugin_list_feature_filter:

   905  * @list: a #GList of plugins to query

   906  * @filter: the filter function to use

   907  * @first: only return first match

   908  * @user_data: user data passed to the filter function

   909  *

   910  * Runs a filter against all plugin features of the plugins in the given

   911  * list and returns a GList with the results.

   912  * If the first flag is set, only the first match is

   913  * returned (as a list with a single object).

   914  *

   915  * Returns: a GList of features, g_list_free after use.

   916  */

   917 GList *

   918 gst_plugin_list_feature_filter (GList * list,

   919     GstPluginFeatureFilter filter, gboolean first, gpointer user_data)

   920 {

   921   FeatureFilterData data;

   922   GList *result;

   923 

   924   data.filter = filter;

   925   data.first = first;

   926   data.user_data = user_data;

   927   data.result = NULL;

   928 

   929   result = gst_filter_run (list, (GstFilterFunc) _feature_filter, first, &data);

   930   g_list_free (result);

   931 

   932   return data.result;

   933 }

   934 #endif

   935 

   936 /**

   937  * gst_plugin_name_filter:

   938  * @plugin: the plugin to check

   939  * @name: the name of the plugin

   940  *

   941  * A standard filter that returns TRUE when the plugin is of the

   942  * given name.

   943  *

   944  * Returns: TRUE if the plugin is of the given name.

   945  */

   946 #ifdef __SYMBIAN32__

   947 EXPORT_C

   948 #endif

   949 

   950 gboolean

   951 gst_plugin_name_filter (GstPlugin * plugin, const gchar * name)

   952 {

   953   return (plugin->desc.name && !strcmp (plugin->desc.name, name));

   954 }

   955 

   956 #if 0

   957 /**

   958  * gst_plugin_find_feature:

   959  * @plugin: plugin to get the feature from

   960  * @name: The name of the feature to find

   961  * @type: The type of the feature to find

   962  *

   963  * Find a feature of the given name and type in the given plugin.

   964  *

   965  * Returns: a GstPluginFeature or NULL if the feature was not found.

   966  */

   967 GstPluginFeature *

   968 gst_plugin_find_feature (GstPlugin * plugin, const gchar * name, GType type)

   969 {

   970   GList *walk;

   971   GstPluginFeature *result = NULL;

   972   GstTypeNameData data;

   973 

   974   g_return_val_if_fail (name != NULL, NULL);

   975 

   976   data.type = type;

   977   data.name = name;

   978 

   979   walk = gst_filter_run (plugin->features,

   980       (GstFilterFunc) gst_plugin_feature_type_name_filter, TRUE, &data);

   981 

   982   if (walk) {

   983     result = GST_PLUGIN_FEATURE (walk->data);

   984 

   985     gst_object_ref (result);

   986     gst_plugin_feature_list_free (walk);

   987   }

   988 

   989   return result;

   990 }

   991 #endif

   992 

   993 #if 0

   994 static gboolean

   995 gst_plugin_feature_name_filter (GstPluginFeature * feature, const gchar * name)

   996 {

   997   return !strcmp (name, GST_PLUGIN_FEATURE_NAME (feature));

   998 }

   999 #endif

  1000 

  1001 #if 0

  1002 /**

  1003  * gst_plugin_find_feature_by_name:

  1004  * @plugin: plugin to get the feature from

  1005  * @name: The name of the feature to find

  1006  *

  1007  * Find a feature of the given name in the given plugin.

  1008  *

  1009  * Returns: a GstPluginFeature or NULL if the feature was not found.

  1010  */

  1011 GstPluginFeature *

  1012 gst_plugin_find_feature_by_name (GstPlugin * plugin, const gchar * name)

  1013 {

  1014   GList *walk;

  1015   GstPluginFeature *result = NULL;

  1016 

  1017   g_return_val_if_fail (name != NULL, NULL);

  1018 

  1019   walk = gst_filter_run (plugin->features,

  1020       (GstFilterFunc) gst_plugin_feature_name_filter, TRUE, (void *) name);

  1021 

  1022   if (walk) {

  1023     result = GST_PLUGIN_FEATURE (walk->data);

  1024 

  1025     gst_object_ref (result);

  1026     gst_plugin_feature_list_free (walk);

  1027   }

  1028 

  1029   return result;

  1030 }

  1031 #endif

  1032 

  1033 /**

  1034  * gst_plugin_load_by_name:

  1035  * @name: name of plugin to load

  1036  *

  1037  * Load the named plugin. Refs the plugin.

  1038  *

  1039  * Returns: A reference to a loaded plugin, or NULL on error.

  1040  */

  1041 #ifdef __SYMBIAN32__

  1042 EXPORT_C

  1043 #endif

  1044 

  1045 GstPlugin *

  1046 gst_plugin_load_by_name (const gchar * name)

  1047 {

  1048   GstPlugin *plugin, *newplugin;

  1049   GError *error = NULL;

  1050 

  1051   GST_DEBUG ("looking up plugin %s in default registry", name);

  1052   plugin = gst_registry_find_plugin (gst_registry_get_default (), name);

  1053   if (plugin) {

  1054     GST_DEBUG ("loading plugin %s from file %s", name, plugin->filename);

  1055     newplugin = gst_plugin_load_file (plugin->filename, &error);

  1056     gst_object_unref (plugin);

  1057 

  1058     if (!newplugin) {

  1059       GST_WARNING ("load_plugin error: %s", error->message);

  1060       g_error_free (error);

  1061       return NULL;

  1062     }

  1063     /* newplugin was reffed by load_file */

  1064     return newplugin;

  1065   }

  1066 

  1067   GST_DEBUG ("Could not find plugin %s in registry", name);

  1068   return NULL;

  1069 }

  1070 

  1071 /**

  1072  * gst_plugin_load:

  1073  * @plugin: plugin to load

  1074  *

  1075  * Loads @plugin. Note that the *return value* is the loaded plugin; @plugin is

  1076  * untouched. The normal use pattern of this function goes like this:

  1077  *

  1078  * <programlisting>

  1079  * GstPlugin *loaded_plugin;

  1080  * loaded_plugin = gst_plugin_load (plugin);

  1081  * // presumably, we're no longer interested in the potentially-unloaded plugin

  1082  * gst_object_unref (plugin);

  1083  * plugin = loaded_plugin;

  1084  * </programlisting>

  1085  *

  1086  * Returns: A reference to a loaded plugin, or NULL on error.

  1087  */

  1088 #ifdef __SYMBIAN32__

  1089 EXPORT_C

  1090 #endif

  1091 

  1092 GstPlugin *

  1093 gst_plugin_load (GstPlugin * plugin)

  1094 {

  1095   GError *error = NULL;

  1096   GstPlugin *newplugin;

  1097 

  1098   if (gst_plugin_is_loaded (plugin)) {

  1099     return plugin;

  1100   }

  1101 

  1102   if (!(newplugin = gst_plugin_load_file (plugin->filename, &error)))

  1103     goto load_error;

  1104 

  1105   return newplugin;

  1106 

  1107 load_error:

  1108   {

  1109     GST_WARNING ("load_plugin error: %s", error->message);

  1110     g_error_free (error);

  1111     return NULL;

  1112   }

  1113 }

  1114 

  1115 /**

  1116  * gst_plugin_list_free:

  1117  * @list: list of #GstPlugin

  1118  *

  1119  * Unrefs each member of @list, then frees the list.

  1120  */

  1121 #ifdef __SYMBIAN32__

  1122 EXPORT_C

  1123 #endif

  1124 

  1125 void

  1126 gst_plugin_list_free (GList * list)

  1127 {

  1128   GList *g;

  1129 

  1130   for (g = list; g; g = g->next) {

  1131     gst_object_unref (GST_PLUGIN_CAST (g->data));

  1132   }

  1133   g_list_free (list);

  1134 }