DeviceProvider: Rename from DeviceMonitor

1 files changed, 596 insertions, 0 deletions

diff --git a/gst/gstdeviceproviderfactory.c b/gst/gstdeviceproviderfactory.c
new file mode 100644
index 000000000..d0586afce
--- /dev/null
+++ b/gst/gstdeviceproviderfactory.c
@@ -0,0 +1,596 @@
+/* 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
+ * @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_create()
+ * functions to create device provider instances or use gst_device_provider_factory_make() 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 =
+      GST_DEVICE_PROVIDER_FACTORY_CAST (g_object_newv
+      (GST_TYPE_DEVICE_PROVIDER_FACTORY, 0, 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)
+    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 = GST_DEVICE_PROVIDER_CAST (g_object_newv (factory->type, 0,
+          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);
+
+  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 or 0 if
+ * the factory is not loaded.
+ *
+ * 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), 0);
+
+  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): a %NULL terminated array of
+ *   klasses 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[0]; classes++) {
+    const gchar *found;
+    guint len;
+
+    if (classes[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: a "/" separate list of klasses 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_classes (GstDeviceProviderFactory * factory,
+    const gchar * classes)
+{
+  gchar **classesv;
+  gboolean res;
+
+  classesv = g_strsplit (classes, "/", 0);
+
+  res = gst_device_provider_factory_has_classesv (factory, classesv);
+
+  g_strfreev (classesv);
+
+  return res;
+}
+
+typedef struct
+{
+  const char *classes;
+  GstRank minrank;
+} FilterData;
+
+static gboolean
+device_provider_filter (GstPluginFeature * feature, FilterData * data)
+{
+  gboolean res;
+
+  /* we only care about device provider factories */
+  if (G_UNLIKELY (!GST_IS_DEVICE_PROVIDER_FACTORY (feature)))
+    return FALSE;
+
+  res = (gst_plugin_feature_get_rank (feature) >= data->minrank) &&
+      gst_device_provider_factory_has_classes (GST_DEVICE_PROVIDER_FACTORY_CAST
+      (feature), data->classes);
+
+  return res;
+}
+
+/**
+ * gst_device_provider_factory_list_get_device_providers:
+ * @classes: a "/" separate list of klasses to match, only match if all classes
+ *  are matched
+ * @minrank: Minimum rank
+ *
+ * Get a list of factories that match all of the given @classes. Only
+ * device providers with a rank greater or equal to @minrank will be
+ * returned.  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
+    (const gchar * classes, GstRank minrank)
+{
+  GList *result;
+  FilterData data;
+
+  /* prepare type */
+  data.classes = classes;
+  data.minrank = minrank;
+
+  /* get the feature list using the filter */
+  result = gst_registry_feature_filter (gst_registry_get (),
+      (GstPluginFeatureFilter) device_provider_filter, FALSE, &data);
+
+  /* sort on rank and name */
+  result = g_list_sort (result, gst_plugin_feature_rank_compare_func);
+
+  return result;
+}