mutter/clutter/clutter/clutter-id-pool.c

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/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Authored By Matthew Allum <mallum@openedhand.com>
*
* Copyright (C) 2006-2008 OpenedHand
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*
*
*
* ClutterIDPool: pool of reusable integer ids associated with pointers.
*
* Author: Øyvind Kolås <pippin@o-hand-com>
*
*/
#ifdef HAVE_CONFIG_H
#include "clutter-build-config.h"
#endif
#include "clutter-debug.h"
#include "clutter-id-pool.h"
struct _ClutterIDPool
{
GArray *array; /* Array of pointers */
GSList *free_ids; /* A stack of freed ids */
};
ClutterIDPool *
_clutter_id_pool_new (guint initial_size)
{
ClutterIDPool *self;
self = g_slice_new (ClutterIDPool);
self->array = g_array_sized_new (FALSE, FALSE,
sizeof (gpointer), initial_size);
self->free_ids = NULL;
return self;
}
void
_clutter_id_pool_free (ClutterIDPool *id_pool)
{
g_return_if_fail (id_pool != NULL);
g_array_free (id_pool->array, TRUE);
g_slist_free (id_pool->free_ids);
g_slice_free (ClutterIDPool, id_pool);
}
guint32
_clutter_id_pool_add (ClutterIDPool *id_pool,
gpointer ptr)
{
gpointer *array;
guint32 retval;
g_return_val_if_fail (id_pool != NULL, 0);
if (id_pool->free_ids) /* There are items on our freelist, reuse one */
{
array = (void*) id_pool->array->data;
retval = GPOINTER_TO_UINT (id_pool->free_ids->data);
id_pool->free_ids = g_slist_remove (id_pool->free_ids,
id_pool->free_ids->data);
array[retval] = ptr;
return retval;
}
/* Allocate new id */
retval = id_pool->array->len;
g_array_append_val (id_pool->array, ptr);
return retval;
}
void
_clutter_id_pool_remove (ClutterIDPool *id_pool,
guint32 id_)
{
gpointer *array;
g_return_if_fail (id_pool != NULL);
array = (void*) id_pool->array->data;
array[id_] = NULL;
id_pool->free_ids = g_slist_prepend (id_pool->free_ids,
GUINT_TO_POINTER (id_));
}
gpointer
_clutter_id_pool_lookup (ClutterIDPool *id_pool,
guint32 id_)
{
gpointer *array;
g_return_val_if_fail (id_pool != NULL, NULL);
g_return_val_if_fail (id_pool->array != NULL, NULL);
array = (void*) id_pool->array->data;
if (id_ >= id_pool->array->len || array[id_] == NULL)
{
g_warning ("The required ID of %u does not refer to an existing actor; "
"this usually implies that the pick() of an actor is not "
"correctly implemented or that there is an error in the "
"glReadPixels() implementation of the GL driver.", id_);
return NULL;
}
return array[id_];
}