/* GStreamer

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

 *                    2000 Wim Taymans <wim.taymans@chello.be>

 *                    2005 Wim Taymans <wim@fluendo.com>

 *

 * gstformat.c: GstFormat registration

 *

 * 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:gstformat

 * @title: GstFormat

 * @short_description: Dynamically register new data formats

 * @see_also: #GstPad, #GstElement

 *

 * GstFormats functions are used to register a new format to the gstreamer

 * core.  Formats can be used to perform seeking or conversions/query

 * operations.

 */

#include "gst_private.h"

#include <string.h>

#include "gstformat.h"

#include "gstenumtypes.h"

static GMutex mutex;

static GList *_gst_formats = NULL;

static GHashTable *_nick_to_format = NULL;

static GHashTable *_format_to_nick = NULL;

static guint32 _n_values = 1;   /* we start from 1 because 0 reserved for UNDEFINED */

static GstFormatDefinition standard_definitions[] = {

  {GST_FORMAT_DEFAULT, "default", "Default format for the media type", 0},

  {GST_FORMAT_BYTES, "bytes", "Bytes", 0},

  {GST_FORMAT_TIME, "time", "Time", 0},

  {GST_FORMAT_BUFFERS, "buffers", "Buffers", 0},

  {GST_FORMAT_PERCENT, "percent", "Percent", 0},

  {GST_FORMAT_UNDEFINED, NULL, NULL, 0}

};

void

_priv_gst_format_initialize (void)

{

  GstFormatDefinition *standards = standard_definitions;

  g_mutex_lock (&mutex);

  if (_nick_to_format == NULL) {

    _nick_to_format = g_hash_table_new (g_str_hash, g_str_equal);

    _format_to_nick = g_hash_table_new (NULL, NULL);

  }

  while (standards->nick) {

    standards->quark = g_quark_from_static_string (standards->nick);

    g_hash_table_insert (_nick_to_format, (gpointer) standards->nick,

        standards);

    g_hash_table_insert (_format_to_nick, GINT_TO_POINTER (standards->value),

        standards);

    _gst_formats = g_list_append (_gst_formats, standards);

    standards++;

    _n_values++;

  }

  /* getting the type registers the enum */

  g_type_class_ref (gst_format_get_type ());

  g_mutex_unlock (&mutex);

}

/**

 * gst_format_get_name:

 * @format: a #GstFormat

 *

 * Get a printable name for the given format. Do not modify or free.

 *

 * Returns: (nullable): a reference to the static name of the format

 * or %NULL if the format is unknown.

 */

const gchar *

gst_format_get_name (GstFormat format)

{

  const GstFormatDefinition *def;

  const gchar *result;

  if ((def = gst_format_get_details (format)) != NULL)

    result = def->nick;

  else

    result = NULL;

  return result;

}

/**

 * gst_format_to_quark:

 * @format: a #GstFormat

 *

 * Get the unique quark for the given format.

 *

 * Returns: the quark associated with the format or 0 if the format

 * is unknown.

 */

GQuark

gst_format_to_quark (GstFormat format)

{

  const GstFormatDefinition *def;

  GQuark result;

  if ((def = gst_format_get_details (format)) != NULL)

    result = def->quark;

  else

    result = 0;

  return result;

}

/**

 * gst_format_register:

 * @nick: The nick of the new format

 * @description: The description of the new format

 *

 * Create a new GstFormat based on the nick or return an

 * already registered format with that nick.

 *

 * Returns: A new GstFormat or an already registered format

 * with the same nick.

 *

 * MT safe.

 */

GstFormat

gst_format_register (const gchar * nick, const gchar * description)

{

  GstFormatDefinition *format;

  GstFormat query;

  g_return_val_if_fail (nick != NULL, GST_FORMAT_UNDEFINED);

  g_return_val_if_fail (description != NULL, GST_FORMAT_UNDEFINED);

  query = gst_format_get_by_nick (nick);

  if (query != GST_FORMAT_UNDEFINED)

    return query;

  g_mutex_lock (&mutex);

  format = g_slice_new (GstFormatDefinition);

  format->value = (GstFormat) _n_values;

  format->nick = g_strdup (nick);

  format->description = g_strdup (description);

  format->quark = g_quark_from_static_string (format->nick);

  g_hash_table_insert (_nick_to_format, (gpointer) format->nick, format);

  g_hash_table_insert (_format_to_nick, GINT_TO_POINTER (format->value),

      format);

  _gst_formats = g_list_append (_gst_formats, format);

  _n_values++;

  g_mutex_unlock (&mutex);

  return format->value;

}

/**

 * gst_format_get_by_nick:

 * @nick: The nick of the format

 *

 * Return the format registered with the given nick.

 *

 * Returns: The format with @nick or GST_FORMAT_UNDEFINED

 * if the format was not registered.

 */

GstFormat

gst_format_get_by_nick (const gchar * nick)

{

  GstFormatDefinition *format;

  g_return_val_if_fail (nick != NULL, GST_FORMAT_UNDEFINED);

  g_mutex_lock (&mutex);

  format = g_hash_table_lookup (_nick_to_format, nick);

  g_mutex_unlock (&mutex);

  if (format != NULL)

    return format->value;

  else

    return GST_FORMAT_UNDEFINED;

}

/**

 * gst_formats_contains:

 * @formats: (array zero-terminated=1): The format array to search

 * @format: the format to find

 *

 * See if the given format is inside the format array.

 *

 * Returns: %TRUE if the format is found inside the array

 */

gboolean

gst_formats_contains (const GstFormat * formats, GstFormat format)

{

  if (!formats)

    return FALSE;

  while (*formats) {

    if (*formats == format)

      return TRUE;

    formats++;

  }

  return FALSE;

}

/**

 * gst_format_get_details:

 * @format: The format to get details of

 *

 * Get details about the given format.

 *

 * Returns: (nullable): The #GstFormatDefinition for @format or %NULL

 * on failure.

 *

 * MT safe.

 */

const GstFormatDefinition *

gst_format_get_details (GstFormat format)

{

  const GstFormatDefinition *result;

  g_mutex_lock (&mutex);

  result = g_hash_table_lookup (_format_to_nick, GINT_TO_POINTER (format));

  g_mutex_unlock (&mutex);

  return result;

}

/**

 * gst_format_iterate_definitions:

 *

 * Iterate all the registered formats. The format definition is read

 * only.

 *

 * Returns: (transfer full): a GstIterator of #GstFormatDefinition.

 */

GstIterator *

gst_format_iterate_definitions (void)

{

  GstIterator *result;

  g_mutex_lock (&mutex);

  /* FIXME: register a boxed type for GstFormatDefinition */

  result = gst_iterator_new_list (G_TYPE_POINTER,

      &mutex, &_n_values, &_gst_formats, NULL, NULL);

  g_mutex_unlock (&mutex);

  return result;

}