/* GStreamer

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

 *                    2000 Wim Taymans <wtay@chello.be>

 *

 * gstpluginfeature.c: Abstract base class for all plugin features

 *

 * 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., 51 Franklin St, Fifth Floor,

 * Boston, MA 02110-1301, USA.

 */

/**

 * SECTION:gstpluginfeature

 * @title: GstPluginfeature

 * @short_description: Base class for contents of a GstPlugin

 * @see_also: #GstPlugin

 *

 * This is a base class for anything that can be added to a #GstPlugin.

 */

#include "gst_private.h"

#include "gstpluginfeature.h"

#include "gstplugin.h"

#include "gstregistry.h"

#include "gstinfo.h"

#include <stdio.h>

#include <string.h>

#define GST_CAT_DEFAULT GST_CAT_PLUGIN_LOADING

static void gst_plugin_feature_finalize (GObject * object);

/* static guint gst_plugin_feature_signals[LAST_SIGNAL] = { 0 }; */

G_DEFINE_ABSTRACT_TYPE (GstPluginFeature, gst_plugin_feature, GST_TYPE_OBJECT);

static void

gst_plugin_feature_class_init (GstPluginFeatureClass * klass)

{

  G_OBJECT_CLASS (klass)->finalize = gst_plugin_feature_finalize;

}

static void

gst_plugin_feature_init (GstPluginFeature * feature)

{

  /* do nothing, needed because of G_DEFINE_TYPE */

}

static void

gst_plugin_feature_finalize (GObject * object)

{

  GstPluginFeature *feature = GST_PLUGIN_FEATURE_CAST (object);

  GST_DEBUG ("finalizing feature %p: '%s'", feature, GST_OBJECT_NAME (feature));

  if (feature->plugin != NULL) {

    g_object_remove_weak_pointer ((GObject *) feature->plugin,

        (gpointer *) & feature->plugin);

  }

  G_OBJECT_CLASS (gst_plugin_feature_parent_class)->finalize (object);

}

/**

 * gst_plugin_feature_load:

 * @feature: (transfer none): the plugin feature to check

 *

 * Loads the plugin containing @feature if it's not already loaded. @feature is

 * unaffected; use the return value instead.

 *

 * Normally this function is used like this:

 * |[

 * GstPluginFeature *loaded_feature;

 *

 * loaded_feature = gst_plugin_feature_load (feature);

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

 * gst_object_unref (feature);

 * feature = loaded_feature;

 * ]|

 *

 * Returns: (transfer full) (nullable): a reference to the loaded

 * feature, or %NULL on error

 */

GstPluginFeature *

gst_plugin_feature_load (GstPluginFeature * feature)

{

  GstPlugin *plugin;

  GstPluginFeature *real_feature;

  g_return_val_if_fail (feature != NULL, FALSE);

  g_return_val_if_fail (GST_IS_PLUGIN_FEATURE (feature), FALSE);

  GST_DEBUG ("loading plugin for feature %p; '%s'", feature,

      GST_OBJECT_NAME (feature));

  if (feature->loaded)

    return gst_object_ref (feature);

  GST_DEBUG ("loading plugin %s", feature->plugin_name);

  plugin = gst_plugin_load_by_name (feature->plugin_name);

  if (!plugin)

    goto load_failed;

  GST_DEBUG ("loaded plugin %s", feature->plugin_name);

  gst_object_unref (plugin);

  real_feature = gst_registry_lookup_feature (gst_registry_get (),

      GST_OBJECT_NAME (feature));

  if (real_feature == NULL)

    goto disappeared;

  else if (!real_feature->loaded)

    goto not_found;

  return real_feature;

  /* ERRORS */

load_failed:

  {

    GST_WARNING ("Failed to load plugin containing feature '%s'.",

        GST_OBJECT_NAME (feature));

    return NULL;

  }

disappeared:

  {

    GST_INFO

        ("Loaded plugin containing feature '%s', but feature disappeared.",

        GST_OBJECT_NAME (feature));

    return NULL;

  }

not_found:

  {

    GST_INFO ("Tried to load plugin containing feature '%s', but feature was "

        "not found.", GST_OBJECT_NAME (real_feature));

    return NULL;

  }

}

/**

 * gst_plugin_feature_set_rank:

 * @feature: feature to rank

 * @rank: rank value - higher number means more priority rank

 *

 * Specifies a rank for a plugin feature, so that autoplugging uses

 * the most appropriate feature.

 */

void

gst_plugin_feature_set_rank (GstPluginFeature * feature, guint rank)

{

  g_return_if_fail (feature != NULL);

  g_return_if_fail (GST_IS_PLUGIN_FEATURE (feature));

  feature->rank = rank;

}

/**

 * gst_plugin_feature_get_rank:

 * @feature: a feature

 *

 * Gets the rank of a plugin feature.

 *

 * Returns: The rank of the feature

 */

guint

gst_plugin_feature_get_rank (GstPluginFeature * feature)

{

  g_return_val_if_fail (GST_IS_PLUGIN_FEATURE (feature), GST_RANK_NONE);

  return feature->rank;

}

/**

 * gst_plugin_feature_get_plugin:

 * @feature: a feature

 *

 * Get the plugin that provides this feature.

 *

 * Returns: (transfer full) (nullable): the plugin that provides this

 *     feature, or %NULL.  Unref with gst_object_unref() when no

 *     longer needed.

 */

GstPlugin *

gst_plugin_feature_get_plugin (GstPluginFeature * feature)

{

  g_return_val_if_fail (GST_IS_PLUGIN_FEATURE (feature), NULL);

  if (feature->plugin == NULL)

    return NULL;

  return (GstPlugin *) gst_object_ref (feature->plugin);

}

/**

 * gst_plugin_feature_get_plugin_name:

 * @feature: a feature

 *

 * Get the name of the plugin that provides this feature.

 *

 * Returns: (nullable): the name of the plugin that provides this

 *     feature, or %NULL if the feature is not associated with a

 *     plugin.

 *

 * Since: 1.2

 */

const gchar *

gst_plugin_feature_get_plugin_name (GstPluginFeature * feature)

{

  g_return_val_if_fail (GST_IS_PLUGIN_FEATURE (feature), NULL);

  if (feature->plugin == NULL)

    return NULL;

  return gst_plugin_get_name (feature->plugin);

}

/**

 * gst_plugin_feature_list_free:

 * @list: (transfer full) (element-type Gst.PluginFeature): list

 *     of #GstPluginFeature

 *

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

 */

void

gst_plugin_feature_list_free (GList * list)

{

  GList *g;

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

    GstPluginFeature *feature = GST_PLUGIN_FEATURE_CAST (g->data);

    gst_object_unref (feature);

  }

  g_list_free (list);

}

/**

 * gst_plugin_feature_list_copy:

 * @list: (transfer none) (element-type Gst.PluginFeature): list

 *     of #GstPluginFeature

 *

 * Copies the list of features. Caller should call @gst_plugin_feature_list_free

 * when done with the list.

 *

 * Returns: (transfer full) (element-type Gst.PluginFeature): a copy of @list,

 *     with each feature's reference count incremented.

 */

GList *

gst_plugin_feature_list_copy (GList * list)

{

  GList *new_list = NULL;

  if (G_LIKELY (list)) {

    GList *last;

    new_list = g_list_alloc ();

    new_list->data = gst_object_ref (list->data);

    new_list->prev = NULL;

    last = new_list;

    list = list->next;

    while (list) {

      last->next = g_list_alloc ();

      last->next->prev = last;

      last = last->next;

      last->data = gst_object_ref (list->data);

      list = list->next;

    }

    last->next = NULL;

  }

  return new_list;

}

/**

 * gst_plugin_feature_list_debug:

 * @list: (transfer none) (element-type Gst.PluginFeature): a #GList of

 *     plugin features

 *

 * Debug the plugin feature names in @list.

 */

void

gst_plugin_feature_list_debug (GList * list)

{

#ifndef GST_DISABLE_GST_DEBUG

  while (list) {

    GST_DEBUG ("%s",

        gst_plugin_feature_get_name ((GstPluginFeature *) list->data));

    list = list->next;

  }

#endif

}

/**

 * gst_plugin_feature_check_version:

 * @feature: a feature

 * @min_major: minimum required major version

 * @min_minor: minimum required minor version

 * @min_micro: minimum required micro version

 *

 * Checks whether the given plugin feature is at least

 *  the required version

 *

 * Returns: %TRUE if the plugin feature has at least

 *  the required version, otherwise %FALSE.

 */

gboolean

gst_plugin_feature_check_version (GstPluginFeature * feature,

    guint min_major, guint min_minor, guint min_micro)

{

  GstRegistry *registry;

  GstPlugin *plugin;

  gboolean ret = FALSE;

  g_return_val_if_fail (feature != NULL, FALSE);

  g_return_val_if_fail (GST_IS_PLUGIN_FEATURE (feature), FALSE);

  GST_DEBUG ("Looking up plugin '%s' containing plugin feature '%s'",

      feature->plugin_name, GST_OBJECT_NAME (feature));

  registry = gst_registry_get ();

  plugin = gst_registry_find_plugin (registry, feature->plugin_name);

  if (plugin) {

    const gchar *ver_str;

    guint major, minor, micro, nano;

    gint nscan;

    ver_str = gst_plugin_get_version (plugin);

    g_return_val_if_fail (ver_str != NULL, FALSE);

    nscan = sscanf (ver_str, "%u.%u.%u.%u", &major, &minor, &micro, &nano;;

    GST_DEBUG ("version string '%s' parsed to %d values", ver_str, nscan);

    if (nscan >= 3) {

      if (major > min_major)

        ret = TRUE;

      else if (major < min_major)

        ret = FALSE;

      else if (minor > min_minor)

        ret = TRUE;

      else if (minor < min_minor)

        ret = FALSE;

      else if (micro > min_micro)

        ret = TRUE;

      /* micro is 1 smaller but we have a nano version, this is the upcoming

       * release of the requested version and we're ok then */

      else if (nscan == 4 && nano > 0 && (micro + 1 == min_micro))

        ret = TRUE;

      else

        ret = (micro == min_micro);

      GST_DEBUG ("Checking whether %u.%u.%u >= %u.%u.%u? %s", major, minor,

          micro, min_major, min_minor, min_micro, (ret) ? "yes" : "no");

    } else {

      GST_WARNING ("Could not parse version string '%s' of plugin '%s'",

          ver_str, feature->plugin_name);

    }

    gst_object_unref (plugin);

  } else {

    GST_DEBUG ("Could not find plugin '%s'", feature->plugin_name);

  }

  return ret;

}

/**

 * gst_plugin_feature_rank_compare_func:

 * @p1: a #GstPluginFeature

 * @p2: a #GstPluginFeature

 *

 * Compares the two given #GstPluginFeature instances. This function can be

 * used as a #GCompareFunc when sorting by rank and then by name.

 *

 * Returns: negative value if the rank of p1 > the rank of p2 or the ranks are

 * equal but the name of p1 comes before the name of p2; zero if the rank

 * and names are equal; positive value if the rank of p1 < the rank of p2 or the

 * ranks are equal but the name of p2 comes before the name of p1

 */

gint

gst_plugin_feature_rank_compare_func (gconstpointer p1, gconstpointer p2)

{

  GstPluginFeature *f1, *f2;

  gint diff;

  f1 = (GstPluginFeature *) p1;

  f2 = (GstPluginFeature *) p2;

  diff = f2->rank - f1->rank;

  if (diff != 0)

    return diff;

  diff = strcmp (GST_OBJECT_NAME (f1), GST_OBJECT_NAME (f2));

  return diff;

}