gstreamer/gst/gstquery.c

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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wim.taymans@chello.be>
* 2005 Wim Taymans <wim@fluendo.com>
*
* gstquery.c: GstQueryType 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include <string.h>
#include "gst_private.h"
#include "gstquery.h"
static GStaticMutex mutex = G_STATIC_MUTEX_INIT;
static GList *_gst_queries = NULL;
static GHashTable *_nick_to_query = NULL;
static GHashTable *_query_type_to_nick = NULL;
static guint32 _n_values = 1; /* we start from 1 because 0 reserved for NONE */
static GstQueryTypeDefinition standard_definitions[] = {
{GST_QUERY_TOTAL, "total", "Total length"},
{GST_QUERY_POSITION, "position", "Current Position"},
{GST_QUERY_LATENCY, "latency", "Latency"},
{GST_QUERY_JITTER, "jitter", "Jitter"},
{GST_QUERY_START, "start", "Start position of stream"},
{GST_QUERY_SEGMENT_END, "segment_end", "End position of the stream"},
{GST_QUERY_RATE, "rate", "Configured rate 1000000 = 1"},
{0, NULL, NULL}
};
void
_gst_query_type_initialize (void)
{
GstQueryTypeDefinition *standards = standard_definitions;
g_static_mutex_lock (&mutex);
if (_nick_to_query == NULL) {
_nick_to_query = g_hash_table_new (g_str_hash, g_str_equal);
_query_type_to_nick = g_hash_table_new (NULL, NULL);
}
while (standards->nick) {
g_hash_table_insert (_nick_to_query, standards->nick, standards);
g_hash_table_insert (_query_type_to_nick,
GINT_TO_POINTER (standards->value), standards);
_gst_queries = g_list_append (_gst_queries, standards);
standards++;
_n_values++;
}
g_static_mutex_unlock (&mutex);
}
/**
* gst_query_type_register:
* @nick: The nick of the new query
* @description: The description of the new query
*
* Create a new GstQueryType based on the nick or return an
* allrady registered query with that nick
*
* Returns: A new GstQueryType or an already registered query
* with the same nick.
*/
GstQueryType
gst_query_type_register (const gchar * nick, const gchar * description)
{
GstQueryTypeDefinition *query;
GstQueryType lookup;
g_return_val_if_fail (nick != NULL, 0);
g_return_val_if_fail (description != NULL, 0);
lookup = gst_query_type_get_by_nick (nick);
if (lookup != GST_QUERY_NONE)
return lookup;
query = g_new0 (GstQueryTypeDefinition, 1);
query->value = _n_values;
query->nick = g_strdup (nick);
query->description = g_strdup (description);
g_static_mutex_lock (&mutex);
g_hash_table_insert (_nick_to_query, query->nick, query);
g_hash_table_insert (_query_type_to_nick, GINT_TO_POINTER (query->value),
query);
_gst_queries = g_list_append (_gst_queries, query);
_n_values++;
g_static_mutex_unlock (&mutex);
return query->value;
}
/**
* gst_query_type_get_by_nick:
* @nick: The nick of the query
*
* Return the query registered with the given nick.
*
* Returns: The query with @nick or GST_QUERY_NONE
* if the query was not registered.
*/
GstQueryType
gst_query_type_get_by_nick (const gchar * nick)
{
GstQueryTypeDefinition *query;
g_return_val_if_fail (nick != NULL, 0);
g_static_mutex_lock (&mutex);
query = g_hash_table_lookup (_nick_to_query, nick);
g_static_mutex_unlock (&mutex);
if (query != NULL)
return query->value;
else
return GST_QUERY_NONE;
}
/**
* gst_query_types_contains:
* @types: The query array to search
* @type: the querytype to find
*
* See if the given query is inside the query array.
*
* Returns: TRUE if the query is found inside the array
*/
gboolean
gst_query_types_contains (const GstQueryType * types, GstQueryType type)
{
if (!types)
return FALSE;
while (*types) {
if (*types == type)
return TRUE;
types++;
}
return FALSE;
}
/**
* gst_query_type_get_details:
* @type: The query to get details of
*
* Get details about the given query.
*
* Returns: The #GstQueryTypeDefinition for @query or NULL on failure.
*/
const GstQueryTypeDefinition *
gst_query_type_get_details (GstQueryType type)
{
const GstQueryTypeDefinition *result;
g_static_mutex_lock (&mutex);
result = g_hash_table_lookup (_query_type_to_nick, GINT_TO_POINTER (type));
g_static_mutex_unlock (&mutex);
return result;
}
/**
* gst_query_type_iterate_definitions:
*
* Get an Iterator of all the registered query types. The querytype
* definition is read only.
*
* Returns: A #GstIterator of #GstQueryTypeDefinition.
*/
GstIterator *
gst_query_type_iterate_definitions (void)
{
GstIterator *result;
g_static_mutex_lock (&mutex);
result = gst_iterator_new_list (g_static_mutex_get_mutex (&mutex),
&_n_values, &_gst_queries, NULL, NULL, NULL);
g_static_mutex_unlock (&mutex);
return result;
}