gstreamer/gst/gstplugin.c

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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* gstplugin.c: Plugin subsystem for loading elements, types, and libs
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <unistd.h>
#include "gst_private.h"
#include "gstplugin.h"
#include "gstversion.h"
#include "gstregistrypool.h"
#include "gstlog.h"
#include "config.h"
#include "gstfilter.h"
static GModule *main_module = NULL;
static GList *_gst_plugin_static = NULL;
static GstPlugin* gst_plugin_register_func (GstPluginDesc *desc, GstPlugin *plugin,
GModule *module);
GQuark
gst_plugin_error_quark (void)
{
static GQuark quark = 0;
if (!quark)
quark = g_quark_from_static_string ("gst_plugin_error");
return quark;
}
/* this function can be called in the GCC constructor extension, before
* the _gst_plugin_initialize() was called. In that case, we store the
* plugin description in a list to initialize it when we open the main
* module later on.
* When the main module is known, we can register the plugin right away.
* */
void
_gst_plugin_register_static (GstPluginDesc *desc)
{
if (main_module == NULL) {
_gst_plugin_static = g_list_prepend (_gst_plugin_static, desc);
}
else {
GstPlugin *plugin;
plugin = g_new0 (GstPlugin, 1);
plugin->filename = NULL;
plugin->module = NULL;
plugin = gst_plugin_register_func (desc, plugin, main_module);
if (plugin) {
plugin->module = main_module;
gst_registry_pool_add_plugin (plugin);
}
}
}
void
_gst_plugin_initialize (void)
{
main_module = g_module_open (NULL, G_MODULE_BIND_LAZY);
/* now register all static plugins */
g_list_foreach (_gst_plugin_static, (GFunc) _gst_plugin_register_static, NULL);
}
static gboolean
gst_plugin_check_version (gint major, gint minor)
{
/* return NULL if the major and minor version numbers are not compatible */
/* with ours. */
if (major != GST_VERSION_MAJOR || minor != GST_VERSION_MINOR)
return FALSE;
return TRUE;
}
static GstPlugin*
gst_plugin_register_func (GstPluginDesc *desc, GstPlugin *plugin, GModule *module)
{
if (!gst_plugin_check_version (desc->major_version, desc->minor_version)) {
GST_INFO (GST_CAT_PLUGIN_LOADING,"plugin \"%s\" has incompatible version, not loading",
plugin->filename);
return NULL;
}
g_free (plugin->name);
plugin->name = g_strdup(desc->name);
if (!((desc->plugin_init) (module, plugin))) {
GST_INFO (GST_CAT_PLUGIN_LOADING,"plugin \"%s\" failed to initialise",
plugin->filename);
return NULL;
}
GST_INFO (GST_CAT_PLUGIN_LOADING,"plugin \"%s\" initialised", GST_STR_NULL (plugin->filename));
return plugin;
}
/**
* gst_plugin_new:
* @filename: The filename of the plugin
*
* Creates a plugin from the given filename
*
* Returns: A new GstPlugin object
*/
GstPlugin*
gst_plugin_new (const gchar *filename)
{
GstPlugin *plugin = g_new0 (GstPlugin, 1);
plugin->filename = g_strdup (filename);
return plugin;
}
/**
* gst_plugin_load_plugin:
* @plugin: The plugin to load
* @error: Pointer to a NULL-valued GError.
*
* Load the given plugin.
*
* Returns: whether or not the plugin loaded. Sets @error as appropriate.
*/
gboolean
gst_plugin_load_plugin (GstPlugin *plugin, GError **error)
{
GModule *module;
GstPluginDesc *desc;
struct stat file_status;
gchar *filename;
g_return_val_if_fail (plugin != NULL, FALSE);
if (plugin->module)
return TRUE;
filename = plugin->filename;
GST_DEBUG (GST_CAT_PLUGIN_LOADING, "attempt to load plugin \"%s\"", filename);
if (g_module_supported () == FALSE) {
g_set_error (error,
GST_PLUGIN_ERROR,
GST_PLUGIN_ERROR_MODULE,
"Dynamic loading not supported");
return FALSE;
}
if (stat (filename, &file_status)) {
g_set_error (error,
GST_PLUGIN_ERROR,
GST_PLUGIN_ERROR_MODULE,
"Problem opening file %s (plugin %s)\n",
filename, plugin->name);
return FALSE;
}
module = g_module_open (filename, G_MODULE_BIND_LAZY);
if (module != NULL) {
if (g_module_symbol (module, "plugin_desc", (gpointer *)&desc)) {
GST_DEBUG (GST_CAT_PLUGIN_LOADING, "plugin \"%s\" loaded, called entry function...", filename);
plugin->filename = g_strdup (filename);
plugin = gst_plugin_register_func (desc, plugin, module);
if (plugin != NULL) {
GST_INFO (GST_CAT_PLUGIN_LOADING, "plugin \"%s\" loaded", plugin->filename);
plugin->module = module;
return TRUE;
}
else {
/* plugin == NULL */
g_set_error (error,
GST_PLUGIN_ERROR,
GST_PLUGIN_ERROR_MODULE,
"gst_plugin_register_func failed for plugin \"%s\"",
filename);
return FALSE;
}
}
else {
g_set_error (error,
GST_PLUGIN_ERROR,
GST_PLUGIN_ERROR_MODULE,
"Could not find plugin_desc in \"%s\"",
filename);
}
return FALSE;
}
else {
g_set_error (error,
GST_PLUGIN_ERROR,
GST_PLUGIN_ERROR_MODULE,
"Error loading plugin %s, reason: %s\n",
filename, g_module_error());
return FALSE;
}
}
/**
* gst_plugin_unload_plugin:
* @plugin: The plugin to unload
*
* Unload the given plugin.
*
* Returns: whether or not the plugin unloaded
*/
gboolean
gst_plugin_unload_plugin (GstPlugin *plugin)
{
g_return_val_if_fail (plugin != NULL, FALSE);
if (!plugin->module)
return TRUE;
if (g_module_close (plugin->module)) {
plugin->module = NULL;
GST_INFO (GST_CAT_PLUGIN_LOADING, "plugin \"%s\" unloaded", plugin->filename);
return TRUE;
}
else {
GST_INFO (GST_CAT_PLUGIN_LOADING, "failed to unload plugin \"%s\"", plugin->filename);
return FALSE;
}
}
/**
* gst_plugin_get_name:
* @plugin: plugin to get the name of
*
* Get the short name of the plugin
*
* Returns: the name of the plugin
*/
const gchar*
gst_plugin_get_name (GstPlugin *plugin)
{
g_return_val_if_fail (plugin != NULL, NULL);
return plugin->name;
}
/**
* gst_plugin_set_name:
* @plugin: plugin to set name of
* @name: new name
*
* Sets the name (should be short) of the plugin.
*/
void
gst_plugin_set_name (GstPlugin *plugin, const gchar *name)
{
g_return_if_fail (plugin != NULL);
g_free (plugin->name);
plugin->name = g_strdup (name);
}
/**
* gst_plugin_set_longname:
* @plugin: plugin to set long name of
* @longname: new long name
*
* Sets the long name (should be descriptive) of the plugin.
*/
void
gst_plugin_set_longname (GstPlugin *plugin, const gchar *longname)
{
g_return_if_fail(plugin != NULL);
g_free(plugin->longname);
plugin->longname = g_strdup(longname);
}
/**
* gst_plugin_get_longname:
* @plugin: plugin to get long name of
*
* Get the long descriptive name of the plugin
*
* Returns: the long name of the plugin
*/
const gchar*
gst_plugin_get_longname (GstPlugin *plugin)
{
g_return_val_if_fail (plugin != NULL, NULL);
return plugin->longname;
}
/**
* gst_plugin_get_filename:
* @plugin: plugin to get the filename of
*
* get the filename of the plugin
*
* Returns: the filename of the plugin
*/
const gchar*
gst_plugin_get_filename (GstPlugin *plugin)
{
g_return_val_if_fail (plugin != NULL, NULL);
return plugin->filename;
}
/**
* gst_plugin_is_loaded:
* @plugin: plugin to query
*
* queries if the plugin is loaded into memory
*
* Returns: TRUE is loaded, FALSE otherwise
*/
gboolean
gst_plugin_is_loaded (GstPlugin *plugin)
{
g_return_val_if_fail (plugin != NULL, FALSE);
return (plugin->module != NULL);
}
/**
* gst_plugin_feature_list:
* @plugin: plugin to query
* @filter: the filter to use
* @first: only return first match
* @user_data: user data passed to the filter function
*
* Runs a filter against all plugin features and returns a GList with
* the results. If the first flag is set, only the first match is
* returned (as a list with a single object).
*
* Returns: a GList of features, g_list_free after use.
*/
GList*
gst_plugin_feature_filter (GstPlugin *plugin,
GstPluginFeatureFilter filter,
gboolean first,
gpointer user_data)
{
return gst_filter_run (plugin->features, (GstFilterFunc) filter, first, user_data);
}
typedef struct
{
GstPluginFeatureFilter filter;
gboolean first;
gpointer user_data;
GList *result;
} FeatureFilterData;
static gboolean
_feature_filter (GstPlugin *plugin, gpointer user_data)
{
GList *result;
FeatureFilterData *data = (FeatureFilterData *) user_data;
result = gst_plugin_feature_filter (plugin, data->filter, data->first, data->user_data);
if (result) {
data->result = g_list_concat (data->result, result);
return TRUE;
}
return FALSE;
}
/**
* gst_plugin_list_feature_list:
* @list: a list of plugins to query
* @filter: the filter to use
* @first: only return first match
* @user_data: user data passed to the filter function
*
* Runs a filter against all plugin features of the plugins in the given
* list and returns a GList with the results.
* If the first flag is set, only the first match is
* returned (as a list with a single object).
*
* Returns: a GList of features, g_list_free after use.
*/
GList*
gst_plugin_list_feature_filter (GList *list,
GstPluginFeatureFilter filter,
gboolean first,
gpointer user_data)
{
FeatureFilterData data;
GList *result;
data.filter = filter;
data.first = first;
data.user_data = user_data;
data.result = NULL;
result = gst_filter_run (list, (GstFilterFunc) _feature_filter, first, &data);
g_list_free (result);
return data.result;
}
/**
* gst_plugin_name_filter:
* @plugin: the plugin to check
* @name: the name of the plugin
*
* A standard filterthat returns TRUE when the plugin is of the
* given name.
*
* Returns: TRUE if the plugin is of the given name.
*/
gboolean
gst_plugin_name_filter (GstPlugin *plugin, const gchar *name)
{
return (plugin->name && !strcmp (plugin->name, name));
}
/**
* gst_plugin_find_feature:
* @plugin: plugin to get the feature from
* @name: The name of the feature to find
* @type: The type of the feature to find
*
* Find a feature of the given name and type in the given plugin.
*
* Returns: a GstPluginFeature or NULL if the feature was not found.
*/
GstPluginFeature*
gst_plugin_find_feature (GstPlugin *plugin, const gchar *name, GType type)
{
GList *walk;
GstPluginFeature *result = NULL;
GstTypeNameData data;
g_return_val_if_fail (name != NULL, NULL);
data.type = type;
data.name = name;
walk = gst_filter_run (plugin->features,
(GstFilterFunc) gst_plugin_feature_type_name_filter, TRUE,
&data);
if (walk)
result = GST_PLUGIN_FEATURE (walk->data);
return result;
}
/**
* gst_plugin_add_feature:
* @plugin: plugin to add feature to
* @feature: feature to add
*
* Add feature to the list of those provided by the plugin.
* There is a separate namespace for each plugin feature type.
* See #gst_plugin_get_feature_list
*/
void
gst_plugin_add_feature (GstPlugin *plugin, GstPluginFeature *feature)
{
GstPluginFeature *oldfeature;
g_return_if_fail (plugin != NULL);
g_return_if_fail (GST_IS_PLUGIN_FEATURE (feature));
g_return_if_fail (feature != NULL);
oldfeature = gst_plugin_find_feature (plugin,
GST_PLUGIN_FEATURE_NAME (feature), G_OBJECT_TYPE (feature));
if (!oldfeature) {
feature->manager = plugin;
plugin->features = g_list_prepend (plugin->features, feature);
plugin->numfeatures++;
}
}
/**
* gst_plugin_get_feature_list:
* @plugin: the plugin to get the features from
*
* get a list of all the features that this plugin provides
*
* Returns: a GList of features, use g_list_free to free the list.
*/
GList*
gst_plugin_get_feature_list (GstPlugin *plugin)
{
g_return_val_if_fail (plugin != NULL, NULL);
return g_list_copy (plugin->features);
}
/**
* gst_plugin_load:
* @name: name of plugin to load
*
* Load the named plugin.
*
* Returns: whether the plugin was loaded or not
*/
gboolean
gst_plugin_load (const gchar *name)
{
GstPlugin *plugin;
GError *error = NULL;
plugin = gst_registry_pool_find_plugin (name);
if (plugin) {
gboolean result = gst_plugin_load_plugin (plugin, &error);
if (error) {
GST_DEBUG (GST_CAT_PLUGIN_LOADING, "load_plugin error: %s\n",
error->message);
g_error_free (error);
}
return result;
}
GST_DEBUG (GST_CAT_PLUGIN_LOADING, "Could not find %s in registry pool",
name);
return FALSE;
}
/**
* gst_library_load:
* @name: name of library to load
*
* Load the named library. Name should be given as
* &quot;liblibrary.so&quot;.
*
* Returns: whether the library was loaded or not
*/
gboolean
gst_library_load (const gchar *name)
{
gboolean res;
/* for now this is the same */
res = gst_plugin_load (name);
return res;
}