gstreamer/gst/gstregistry.c

/* GStreamer
 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
 *                    2000 Wim Taymans <wtay@chello.be>
 *
 * gstregistry.c: handle registry
 *
 * 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:gstregistry
 * @short_description: Abstract base class for management of #GstPlugin objects
 * @see_also: #GstPlugin, #GstPluginFeature
 *
 * One registry holds the metadata of a set of plugins.
 * All registries build the #GstRegistryPool.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gst_private.h"
#include <glib.h>
#include <sys/types.h>
#include <sys/stat.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <errno.h>
#include <stdio.h>
#include <string.h>


#include "gstinfo.h"
#include "gstregistry.h"
#include "gstregistrypool.h"
#include "gstmarshal.h"
#include "gstfilter.h"

#define GST_CAT_DEFAULT GST_CAT_GST_INIT

/* Element signals and args */
enum
{
  PLUGIN_ADDED,
  LAST_SIGNAL
};

static void gst_registry_class_init (GstRegistryClass * klass);
static void gst_registry_init (GstRegistry * registry);

static GObjectClass *parent_class = NULL;
static guint gst_registry_signals[LAST_SIGNAL] = { 0 };

GType
gst_registry_get_type (void)
{
  static GType registry_type = 0;

  if (!registry_type) {
    static const GTypeInfo registry_info = {
      sizeof (GstRegistryClass),
      NULL,
      NULL,
      (GClassInitFunc) gst_registry_class_init,
      NULL,
      NULL,
      sizeof (GstRegistry),
      0,
      (GInstanceInitFunc) gst_registry_init,
      NULL
    };

    registry_type = g_type_register_static (G_TYPE_OBJECT, "GstRegistry",
        &registry_info, G_TYPE_FLAG_ABSTRACT);
  }
  return registry_type;
}

static void
gst_registry_class_init (GstRegistryClass * klass)
{
  GObjectClass *gobject_class;

  gobject_class = (GObjectClass *) klass;

  parent_class = g_type_class_ref (G_TYPE_OBJECT);

  gst_registry_signals[PLUGIN_ADDED] =
      g_signal_new ("plugin-added", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstRegistryClass, plugin_added), NULL,
      NULL, gst_marshal_VOID__POINTER, G_TYPE_NONE, 1, G_TYPE_POINTER);

  gobject_class->dispose = NULL;
}

static void
gst_registry_init (GstRegistry * registry)
{
  registry->priority = 0;
  registry->loaded = FALSE;
  registry->paths = NULL;
}

/**
 * gst_registry_load:
 * @registry: the registry to load
 *
 * Load the given registry
 *
 * Returns: TRUE on success.
 */
gboolean
gst_registry_load (GstRegistry * registry)
{
  GstRegistryClass *rclass;

  g_return_val_if_fail (GST_IS_REGISTRY (registry), FALSE);

  rclass = GST_REGISTRY_GET_CLASS (registry);

  if (rclass->load)
    return rclass->load (registry);

  return FALSE;
}

/**
 * gst_registry_is_loaded:
 * @registry: the registry to check
 *
 * Check if the given registry is loaded
 *
 * Returns: TRUE if loaded.
 */
gboolean
gst_registry_is_loaded (GstRegistry * registry)
{
  g_return_val_if_fail (GST_IS_REGISTRY (registry), FALSE);

  return registry->loaded;
}

/**
 * gst_registry_save:
 * @registry: the registry to save
 *
 * Save the contents of the given registry
 *
 * Returns: TRUE on success
 */
gboolean
gst_registry_save (GstRegistry * registry)
{
  GstRegistryClass *rclass;

  g_return_val_if_fail (GST_IS_REGISTRY (registry), FALSE);

  rclass = GST_REGISTRY_GET_CLASS (registry);

  if (rclass->save)
    return rclass->save (registry);

  return FALSE;
}

/**
 * gst_registry_rebuild:
 * @registry: the registry to rebuild
 *
 * Rebuild the given registry
 *
 * Returns: TRUE on success
 */
gboolean
gst_registry_rebuild (GstRegistry * registry)
{
  GstRegistryClass *rclass;

  g_return_val_if_fail (GST_IS_REGISTRY (registry), FALSE);

  rclass = GST_REGISTRY_GET_CLASS (registry);

  if (rclass->rebuild)
    return rclass->rebuild (registry);

  return FALSE;
}

/**
 * gst_registry_unload:
 * @registry: the registry to unload
 *
 * Unload the given registry
 *
 * Returns: TRUE on success
 */
gboolean
gst_registry_unload (GstRegistry * registry)
{
  GstRegistryClass *rclass;

  g_return_val_if_fail (GST_IS_REGISTRY (registry), FALSE);

  rclass = GST_REGISTRY_GET_CLASS (registry);

  if (rclass->unload)
    return rclass->unload (registry);

  return FALSE;
}

/**
 * gst_registry_add_path:
 * @registry: the registry to add the path to
 * @path: the path to add to the registry
 *
 * Add the given path to the registry. The syntax of the
 * path is specific to the registry. If the path has already been
 * added, do nothing.
 */
void
gst_registry_add_path (GstRegistry * registry, const gchar * path)
{
  g_return_if_fail (GST_IS_REGISTRY (registry));
  g_return_if_fail (path != NULL);

  if (strlen (path) == 0) {
    GST_INFO ("Ignoring empty plugin path");
    return;
  }

  if (g_list_find_custom (registry->paths, path, (GCompareFunc) strcmp)) {
    g_warning ("path %s already added to registry", path);
    return;
  }

  GST_INFO ("Adding plugin path: \"%s\"", path);
  registry->paths = g_list_append (registry->paths, g_strdup (path));
}

/**
 * gst_registry_get_path_list:
 * @registry: the registry to get the pathlist of
 *
 * Get the list of paths for the given registry.
 *
 * Returns: A Glist of paths as strings. g_list_free after use.
 */
GList *
gst_registry_get_path_list (GstRegistry * registry)
{
  g_return_val_if_fail (GST_IS_REGISTRY (registry), NULL);

  return g_list_copy (registry->paths);
}


/**
 * gst_registry_clear_paths:
 * @registry: the registry to clear the paths of
 *
 * Clear the paths of the given registry
 */
void
gst_registry_clear_paths (GstRegistry * registry)
{
  g_return_if_fail (GST_IS_REGISTRY (registry));

  g_list_foreach (registry->paths, (GFunc) g_free, NULL);
  g_list_free (registry->paths);

  registry->paths = NULL;
}

/**
 * gst_registry_add_plugin:
 * @registry: the registry to add the plugin to
 * @plugin: the plugin to add
 *
 * Add the plugin to the registry. The plugin-added signal will be emitted.
 *
 * Returns: TRUE on success.
 */
gboolean
gst_registry_add_plugin (GstRegistry * registry, GstPlugin * plugin)
{
  g_return_val_if_fail (GST_IS_REGISTRY (registry), FALSE);
  if (gst_registry_pool_find_plugin (gst_plugin_get_name (plugin))) {
    GST_WARNING_OBJECT (registry, "Not adding plugin %s, "
        "because a plugin with same name already exists",
        gst_plugin_get_name (plugin));
    return FALSE;
  }

  plugin->manager = registry;
  registry->plugins = g_list_prepend (registry->plugins, plugin);

  GST_DEBUG ("emitting plugin-added for filename %s", plugin->filename);
  g_signal_emit (G_OBJECT (registry), gst_registry_signals[PLUGIN_ADDED], 0,
      plugin);

  return TRUE;
}

/**
 * gst_registry_remove_plugin:
 * @registry: the registry to remove the plugin from
 * @plugin: the plugin to remove
 *
 * Remove the plugin from the registry.
 */
void
gst_registry_remove_plugin (GstRegistry * registry, GstPlugin * plugin)
{
  g_return_if_fail (GST_IS_REGISTRY (registry));

  registry->plugins = g_list_remove (registry->plugins, plugin);
}

/**
 * gst_registry_plugin_filter:
 * @registry: registry 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 plugins in the registry 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 plugins, g_list_free after use.
 */
GList *
gst_registry_plugin_filter (GstRegistry * registry,
    GstPluginFilter filter, gboolean first, gpointer user_data)
{
  g_return_val_if_fail (GST_IS_REGISTRY (registry), NULL);

  return gst_filter_run (registry->plugins, (GstFilterFunc) filter, first,
      user_data);
}

/**
 * gst_registry_feature_filter:
 * @registry: registry 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 features of the plugins in the registry
 * 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 plugin features, g_list_free after use.
 */
GList *
gst_registry_feature_filter (GstRegistry * registry,
    GstPluginFeatureFilter filter, gboolean first, gpointer user_data)
{
  g_return_val_if_fail (GST_IS_REGISTRY (registry), NULL);

  return gst_plugin_list_feature_filter (registry->plugins, filter, first,
      user_data);
}

/**
 * gst_registry_find_plugin:
 * @registry: the registry to search
 * @name: the plugin name to find
 *
 * Find the plugin with the given name in the registry.
 *
 * Returns: The plugin with the given name or NULL if the plugin was not found.
 */
GstPlugin *
gst_registry_find_plugin (GstRegistry * registry, const gchar * name)
{
  GList *walk;
  GstPlugin *result = NULL;

  g_return_val_if_fail (GST_IS_REGISTRY (registry), NULL);
  g_return_val_if_fail (name != NULL, NULL);

  walk = gst_registry_plugin_filter (registry,
      (GstPluginFilter) gst_plugin_name_filter, TRUE, (gpointer) name);
  if (walk)
    result = GST_PLUGIN (walk->data);

  g_list_free (walk);

  return result;
}

/**
 * gst_registry_find_feature:
 * @registry: the registry to search
 * @name: the pluginfeature name to find
 * @type: the pluginfeature type to find
 *
 * Find the pluginfeature with the given name and type in the registry.
 *
 * Returns: The pluginfeature with the given name and type or NULL
 * if the plugin was not found.
 */
GstPluginFeature *
gst_registry_find_feature (GstRegistry * registry, const gchar * name,
    GType type)
{
  GstPluginFeature *feature = NULL;
  GList *walk;
  GstTypeNameData data;

  g_return_val_if_fail (GST_IS_REGISTRY (registry), NULL);
  g_return_val_if_fail (name != NULL, NULL);

  data.name = name;
  data.type = type;

  walk = gst_registry_feature_filter (registry,
      (GstPluginFeatureFilter) gst_plugin_feature_type_name_filter,
      TRUE, &data);

  if (walk)
    feature = GST_PLUGIN_FEATURE (walk->data);

  g_list_free (walk);

  return feature;
}


/**
 * gst_registry_load_plugin:
 * @registry: the registry to load the plugin from
 * @plugin: the plugin to load
 *
 * Bring the plugin from the registry into memory.
 *
 * Returns: a value indicating the result
 */
GstRegistryReturn
gst_registry_load_plugin (GstRegistry * registry, GstPlugin * plugin)
{
  GstRegistryClass *rclass;

  g_return_val_if_fail (GST_IS_REGISTRY (registry),
      GST_REGISTRY_PLUGIN_LOAD_ERROR);

  rclass = GST_REGISTRY_GET_CLASS (registry);

  if (rclass->load_plugin)
    return rclass->load_plugin (registry, plugin);

  return GST_REGISTRY_PLUGIN_LOAD_ERROR;
}

/**
 * gst_registry_unload_plugin:
 * @registry: the registry to unload the plugin from
 * @plugin: the plugin to unload
 *
 * Unload the plugin from the given registry.
 *
 * Returns: a value indicating the result
 */
GstRegistryReturn
gst_registry_unload_plugin (GstRegistry * registry, GstPlugin * plugin)
{
  GstRegistryClass *rclass;

  g_return_val_if_fail (GST_IS_REGISTRY (registry),
      GST_REGISTRY_PLUGIN_LOAD_ERROR);

  rclass = GST_REGISTRY_GET_CLASS (registry);

  if (rclass->unload_plugin)
    return rclass->unload_plugin (registry, plugin);

  return GST_REGISTRY_PLUGIN_LOAD_ERROR;
}

/**
 * gst_registry_update_plugin:
 * @registry: the registry to update
 * @plugin: the plugin to update
 *
 * Update the plugin in the given registry.
 *
 * Returns: a value indicating the result
 */
GstRegistryReturn
gst_registry_update_plugin (GstRegistry * registry, GstPlugin * plugin)
{
  GstRegistryClass *rclass;

  g_return_val_if_fail (GST_IS_REGISTRY (registry),
      GST_REGISTRY_PLUGIN_LOAD_ERROR);

  rclass = GST_REGISTRY_GET_CLASS (registry);

  if (rclass->update_plugin)
    return rclass->update_plugin (registry, plugin);

  return GST_REGISTRY_PLUGIN_LOAD_ERROR;
}