/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
* 2003 Benjamin Otte <in7y118@public.uni-hamburg.de>
*
* gstdeviceproviderfactory.c: GstDeviceProviderFactory object, support routines
*
* 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.
*/
/**
* SECTION:gstdeviceproviderfactory
* @title: GstDeviceProviderFactory
* @short_description: Create GstDeviceProviders from a factory
* @see_also: #GstDeviceProvider, #GstPlugin, #GstPluginFeature, #GstPadTemplate.
*
* #GstDeviceProviderFactory is used to create instances of device providers. A
* GstDeviceProviderfactory can be added to a #GstPlugin as it is also a
* #GstPluginFeature.
*
* Use the gst_device_provider_factory_find() and
* gst_device_provider_factory_get() functions to create device
* provider instances or use gst_device_provider_factory_get_by_name() as a
* convenient shortcut.
*
* Since: 1.4
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gst_private.h"
#include "gstdeviceproviderfactory.h"
#include "gst.h"
#include "glib-compat-private.h"
GST_DEBUG_CATEGORY_STATIC (device_provider_factory_debug);
#define GST_CAT_DEFAULT device_provider_factory_debug
static void gst_device_provider_factory_finalize (GObject * object);
static void gst_device_provider_factory_cleanup (GstDeviceProviderFactory *
factory);
/* static guint gst_device_provider_factory_signals[LAST_SIGNAL] = { 0 }; */
/* this is defined in gstelement.c */
extern GQuark __gst_deviceproviderclass_factory;
#define _do_init \
{ \
GST_DEBUG_CATEGORY_INIT (device_provider_factory_debug, "GST_DEVICE_PROVIDER_FACTORY", \
GST_DEBUG_BOLD | GST_DEBUG_FG_WHITE | GST_DEBUG_BG_RED, \
"device provider factories keep information about installed device providers"); \
}
G_DEFINE_TYPE_WITH_CODE (GstDeviceProviderFactory, gst_device_provider_factory,
GST_TYPE_PLUGIN_FEATURE, _do_init);
static void
gst_device_provider_factory_class_init (GstDeviceProviderFactoryClass * klass)
{
GObjectClass *gobject_class = (GObjectClass *) klass;
gobject_class->finalize = gst_device_provider_factory_finalize;
}
static void
gst_device_provider_factory_init (GstDeviceProviderFactory * factory)
{
}
static void
gst_device_provider_factory_finalize (GObject * object)
{
GstDeviceProviderFactory *factory = GST_DEVICE_PROVIDER_FACTORY (object);
GstDeviceProvider *provider;
gst_device_provider_factory_cleanup (factory);
provider = g_atomic_pointer_get (&factory->provider);
if (provider)
gst_object_unref (provider);
G_OBJECT_CLASS (gst_device_provider_factory_parent_class)->finalize (object);
}
/**
* gst_device_provider_factory_find:
* @name: name of factory to find
*
* Search for an device provider factory of the given name. Refs the returned
* device provider factory; caller is responsible for unreffing.
*
* Returns: (transfer full) (nullable): #GstDeviceProviderFactory if
* found, %NULL otherwise
*
* Since: 1.4
*/
GstDeviceProviderFactory *
gst_device_provider_factory_find (const gchar * name)
{
GstPluginFeature *feature;
g_return_val_if_fail (name != NULL, NULL);
feature = gst_registry_find_feature (gst_registry_get (), name,
GST_TYPE_DEVICE_PROVIDER_FACTORY);
if (feature)
return GST_DEVICE_PROVIDER_FACTORY (feature);
/* this isn't an error, for instance when you query if an device provider factory is
* present */
GST_LOG ("no such device provider factory \"%s\"", name);
return NULL;
}
static void
gst_device_provider_factory_cleanup (GstDeviceProviderFactory * factory)
{
if (factory->metadata) {
gst_structure_free ((GstStructure *) factory->metadata);
factory->metadata = NULL;
}
if (factory->type) {
factory->type = G_TYPE_INVALID;
}
}
#define CHECK_METADATA_FIELD(klass, name, key) \
G_STMT_START { \
const gchar *metafield = gst_device_provider_class_get_metadata (klass, key); \
if (G_UNLIKELY (metafield == NULL || *metafield == '\0')) { \
g_warning ("Device provider factory metadata for '%s' has no valid %s field", name, key); \
goto detailserror; \
} \
} G_STMT_END;
/**
* gst_device_provider_register:
* @plugin: (allow-none): #GstPlugin to register the device provider with, or %NULL for
* a static device provider.
* @name: name of device providers of this type
* @rank: rank of device provider (higher rank means more importance when autoplugging)
* @type: GType of device provider to register
*
* Create a new device providerfactory capable of instantiating objects of the
* @type and add the factory to @plugin.
*
* Returns: %TRUE, if the registering succeeded, %FALSE on error
*
* Since: 1.4
*/
gboolean
gst_device_provider_register (GstPlugin * plugin, const gchar * name,
guint rank, GType type)
{
GstPluginFeature *existing_feature;
GstRegistry *registry;
GstDeviceProviderFactory *factory;
GstDeviceProviderClass *klass;
g_return_val_if_fail (name != NULL, FALSE);
g_return_val_if_fail (g_type_is_a (type, GST_TYPE_DEVICE_PROVIDER), FALSE);
registry = gst_registry_get ();
/* check if feature already exists, if it exists there is no need to update it
* when the registry is getting updated, outdated plugins and all their
* features are removed and readded.
*/
existing_feature = gst_registry_lookup_feature (registry, name);
if (existing_feature) {
GST_DEBUG_OBJECT (registry, "update existing feature %p (%s)",
existing_feature, name);
factory = GST_DEVICE_PROVIDER_FACTORY_CAST (existing_feature);
factory->type = type;
existing_feature->loaded = TRUE;
g_type_set_qdata (type, __gst_deviceproviderclass_factory, factory);
gst_object_unref (existing_feature);
return TRUE;
}
factory = g_object_new (GST_TYPE_DEVICE_PROVIDER_FACTORY, NULL);
gst_plugin_feature_set_name (GST_PLUGIN_FEATURE_CAST (factory), name);
GST_LOG_OBJECT (factory, "Created new device providerfactory for type %s",
g_type_name (type));
/* provide info needed during class structure setup */
g_type_set_qdata (type, __gst_deviceproviderclass_factory, factory);
klass = GST_DEVICE_PROVIDER_CLASS (g_type_class_ref (type));
CHECK_METADATA_FIELD (klass, name, GST_ELEMENT_METADATA_LONGNAME);
CHECK_METADATA_FIELD (klass, name, GST_ELEMENT_METADATA_KLASS);
CHECK_METADATA_FIELD (klass, name, GST_ELEMENT_METADATA_DESCRIPTION);
CHECK_METADATA_FIELD (klass, name, GST_ELEMENT_METADATA_AUTHOR);
factory->type = type;
factory->metadata = gst_structure_copy ((GstStructure *) klass->metadata);
if (plugin && plugin->desc.name) {
GST_PLUGIN_FEATURE_CAST (factory)->plugin_name = plugin->desc.name;
GST_PLUGIN_FEATURE_CAST (factory)->plugin = plugin;
g_object_add_weak_pointer ((GObject *) plugin,
(gpointer *) & GST_PLUGIN_FEATURE_CAST (factory)->plugin);
} else {
GST_PLUGIN_FEATURE_CAST (factory)->plugin_name = "NULL";
GST_PLUGIN_FEATURE_CAST (factory)->plugin = NULL;
}
gst_plugin_feature_set_rank (GST_PLUGIN_FEATURE_CAST (factory), rank);
GST_PLUGIN_FEATURE_CAST (factory)->loaded = TRUE;
gst_registry_add_feature (registry, GST_PLUGIN_FEATURE_CAST (factory));
return TRUE;
/* ERRORS */
detailserror:
{
gst_device_provider_factory_cleanup (factory);
return FALSE;
}
}
/**
* gst_device_provider_factory_get:
* @factory: factory to instantiate
*
* Returns the device provider of the type defined by the given device
* providerfactory.
*
* Returns: (transfer full) (nullable): the #GstDeviceProvider or %NULL
* if the device provider couldn't be created
*
* Since: 1.4
*/
GstDeviceProvider *
gst_device_provider_factory_get (GstDeviceProviderFactory * factory)
{
GstDeviceProvider *device_provider;
GstDeviceProviderClass *oclass;
GstDeviceProviderFactory *newfactory;
g_return_val_if_fail (factory != NULL, NULL);
newfactory =
GST_DEVICE_PROVIDER_FACTORY (gst_plugin_feature_load (GST_PLUGIN_FEATURE
(factory)));
if (newfactory == NULL)
goto load_failed;
factory = newfactory;
GST_INFO ("getting device provider \"%s\"", GST_OBJECT_NAME (factory));
if (factory->type == 0)
goto no_type;
device_provider = g_atomic_pointer_get (&newfactory->provider);
if (device_provider) {
gst_object_unref (factory);
return gst_object_ref (device_provider);
}
/* create an instance of the device provider, cast so we don't assert on NULL
* also set name as early as we can
*/
device_provider = g_object_new (factory->type, NULL);
if (G_UNLIKELY (device_provider == NULL))
goto no_device_provider;
/* fill in the pointer to the factory in the device provider class. The
* class will not be unreffed currently.
* Be thread safe as there might be 2 threads creating the first instance of
* an device provider at the same moment
*/
oclass = GST_DEVICE_PROVIDER_GET_CLASS (device_provider);
if (!g_atomic_pointer_compare_and_exchange (&oclass->factory, NULL, factory)) {
gst_object_unref (factory);
} else {
/* This ref will never be dropped as the class is never destroyed */
GST_OBJECT_FLAG_SET (factory, GST_OBJECT_FLAG_MAY_BE_LEAKED);
}
gst_object_ref_sink (device_provider);
/* We use an atomic to make sure we don't create two in parallel */
if (!g_atomic_pointer_compare_and_exchange (&newfactory->provider, NULL,
device_provider)) {
gst_object_unref (device_provider);
device_provider = g_atomic_pointer_get (&newfactory->provider);
}
GST_DEBUG ("created device provider \"%s\"", GST_OBJECT_NAME (factory));
return gst_object_ref (device_provider);
/* ERRORS */
load_failed:
{
GST_WARNING_OBJECT (factory,
"loading plugin containing feature %s returned NULL!",
GST_OBJECT_NAME (factory));
return NULL;
}
no_type:
{
GST_WARNING_OBJECT (factory, "factory has no type");
gst_object_unref (factory);
return NULL;
}
no_device_provider:
{
GST_WARNING_OBJECT (factory, "could not create device provider");
gst_object_unref (factory);
return NULL;
}
}
/**
* gst_device_provider_factory_get_by_name:
* @factoryname: a named factory to instantiate
*
* Returns the device provider of the type defined by the given device
* provider factory.
*
* Returns: (transfer full) (nullable): a #GstDeviceProvider or %NULL
* if unable to create device provider
*
* Since: 1.4
*/
GstDeviceProvider *
gst_device_provider_factory_get_by_name (const gchar * factoryname)
{
GstDeviceProviderFactory *factory;
GstDeviceProvider *device_provider;
g_return_val_if_fail (factoryname != NULL, NULL);
g_return_val_if_fail (gst_is_initialized (), NULL);
GST_LOG ("gstdeviceproviderfactory: get_by_name \"%s\"", factoryname);
factory = gst_device_provider_factory_find (factoryname);
if (factory == NULL)
goto no_factory;
GST_LOG_OBJECT (factory, "found factory %p", factory);
device_provider = gst_device_provider_factory_get (factory);
if (device_provider == NULL)
goto create_failed;
gst_object_unref (factory);
return device_provider;
/* ERRORS */
no_factory:
{
GST_INFO ("no such device provider factory \"%s\"!", factoryname);
return NULL;
}
create_failed:
{
GST_INFO_OBJECT (factory, "couldn't create instance!");
gst_object_unref (factory);
return NULL;
}
}
/**
* gst_device_provider_factory_get_device_provider_type:
* @factory: factory to get managed #GType from
*
* Get the #GType for device providers managed by this factory. The type can
* only be retrieved if the device provider factory is loaded, which can be
* assured with gst_plugin_feature_load().
*
* Returns: the #GType for device providers managed by this factory.
*
* Since: 1.4
*/
GType
gst_device_provider_factory_get_device_provider_type (GstDeviceProviderFactory *
factory)
{
g_return_val_if_fail (GST_IS_DEVICE_PROVIDER_FACTORY (factory),
G_TYPE_INVALID);
return factory->type;
}
/**
* gst_device_provider_factory_get_metadata:
* @factory: a #GstDeviceProviderFactory
* @key: a key
*
* Get the metadata on @factory with @key.
*
* Returns: (nullable): the metadata with @key on @factory or %NULL
* when there was no metadata with the given @key.
*
* Since: 1.4
*/
const gchar *
gst_device_provider_factory_get_metadata (GstDeviceProviderFactory * factory,
const gchar * key)
{
return gst_structure_get_string ((GstStructure *) factory->metadata, key);
}
/**
* gst_device_provider_factory_get_metadata_keys:
* @factory: a #GstDeviceProviderFactory
*
* Get the available keys for the metadata on @factory.
*
* Returns: (transfer full) (element-type utf8) (array zero-terminated=1) (nullable):
* a %NULL-terminated array of key strings, or %NULL when there is no
* metadata. Free with g_strfreev() when no longer needed.
*
* Since: 1.4
*/
gchar **
gst_device_provider_factory_get_metadata_keys (GstDeviceProviderFactory *
factory)
{
GstStructure *metadata;
gchar **arr;
gint i, num;
g_return_val_if_fail (GST_IS_DEVICE_PROVIDER_FACTORY (factory), NULL);
metadata = (GstStructure *) factory->metadata;
if (metadata == NULL)
return NULL;
num = gst_structure_n_fields (metadata);
if (num == 0)
return NULL;
arr = g_new (gchar *, num + 1);
for (i = 0; i < num; ++i) {
arr[i] = g_strdup (gst_structure_nth_field_name (metadata, i));
}
arr[i] = NULL;
return arr;
}
/**
* gst_device_provider_factory_has_classesv:
* @factory: a #GstDeviceProviderFactory
* @classes: (array zero-terminated=1) (allow-none): a %NULL terminated array
* of classes to match, only match if all classes are matched
*
* Check if @factory matches all of the given classes
*
* Returns: %TRUE if @factory matches.
*
* Since: 1.4
*/
gboolean
gst_device_provider_factory_has_classesv (GstDeviceProviderFactory * factory,
gchar ** classes)
{
const gchar *klass;
g_return_val_if_fail (GST_IS_DEVICE_PROVIDER_FACTORY (factory), FALSE);
klass = gst_device_provider_factory_get_metadata (factory,
GST_ELEMENT_METADATA_KLASS);
if (klass == NULL) {
GST_ERROR_OBJECT (factory,
"device provider factory is missing klass identifiers");
return FALSE;
}
for (; classes != NULL && classes[0] != NULL; classes++) {
const gchar *found;
guint len;
if (classes[0][0] == '\0')
continue;
found = strstr (klass, classes[0]);
if (!found)
return FALSE;
if (found != klass && *(found - 1) != '/')
return FALSE;
len = strlen (classes[0]);
if (found[len] != 0 && found[len] != '/')
return FALSE;
}
return TRUE;
}
/**
* gst_device_provider_factory_has_classes:
* @factory: a #GstDeviceProviderFactory
* @classes: (allow-none): a "/" separate list of classes to match, only match
* if all classes are matched
*
* Check if @factory matches all of the given @classes
*
* Returns: %TRUE if @factory matches or if @classes is %NULL.
*
* Since: 1.4
*/
gboolean
gst_device_provider_factory_has_classes (GstDeviceProviderFactory * factory,
const gchar * classes)
{
gchar **classesv;
gboolean res;
if (classes == NULL)
return TRUE;
classesv = g_strsplit (classes, "/", 0);
res = gst_device_provider_factory_has_classesv (factory, classesv);
g_strfreev (classesv);
return res;
}
static gboolean
device_provider_filter (GstPluginFeature * feature, GstRank * minrank)
{
/* we only care about device provider factories */
if (G_UNLIKELY (!GST_IS_DEVICE_PROVIDER_FACTORY (feature)))
return FALSE;
return (gst_plugin_feature_get_rank (feature) >= *minrank);
}
/**
* gst_device_provider_factory_list_get_device_providers:
* @minrank: Minimum rank
*
* Get a list of factories with a rank greater or equal to @minrank.
* The list of factories is returned by decreasing rank.
*
* Returns: (transfer full) (element-type Gst.DeviceProviderFactory):
* a #GList of #GstDeviceProviderFactory device providers. Use
* gst_plugin_feature_list_free() after usage.
*
* Since: 1.4
*/
GList *
gst_device_provider_factory_list_get_device_providers (GstRank minrank)
{
GList *result;
/* get the feature list using the filter */
result = gst_registry_feature_filter (gst_registry_get (),
(GstPluginFeatureFilter) device_provider_filter, FALSE, &minrank);
/* sort on rank and name */
result = g_list_sort (result, gst_plugin_feature_rank_compare_func);
return result;
}