blender-archive/source/blender/blenlib/BLI_gsqueue.h

/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): none yet.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#ifndef __BLI_GSQUEUE_H__
#define __BLI_GSQUEUE_H__

/** \file BLI_gsqueue.h
 *  \ingroup bli
 *  \brief A generic structure queue (a queue for fixed length
 *   (generally small) structures.
 */

typedef struct _GSQueue GSQueue;

/**
 * Create a new GSQueue.
 *
 * \param elem_size The size of the structures in the queue.
 * \retval The new queue
 */
GSQueue    *BLI_gsqueue_new(int elem_size);

/**
 * Query if the queue is empty
 */
int         BLI_gsqueue_is_empty(GSQueue *gq);

/**
 * Query number elements in the queue
 */
int         BLI_gsqueue_size(GSQueue *gq);

/**
 * Access the item at the head of the queue
 * without removing it.
 *
 * \param item_r A pointer to an appropriately
 * sized structure (the size passed to BLI_gsqueue_new)
 */
void        BLI_gsqueue_peek(GSQueue *gq, void *item_r);

/**
 * Access the item at the head of the queue
 * and remove it.
 *
 * \param item_r A pointer to an appropriately
 * sized structure (the size passed to BLI_gsqueue_new).
 * Can be NULL if desired.
 */
void        BLI_gsqueue_pop(GSQueue *gq, void *item_r);

/**
 * Push an element onto the tail of the queue.
 *
 * \param item A pointer to an appropriately
 * sized structure (the size passed to BLI_gsqueue_new).
 */
void        BLI_gsqueue_push(GSQueue *gq, void *item);

/**
 * Push an element back onto the head of the queue (so
 * it would be returned from the next call to BLI_gsqueue_pop).
 *
 * \param item A pointer to an appropriately
 * sized structure (the size passed to BLI_gsqueue_new).
 */
void        BLI_gsqueue_pushback(GSQueue *gq, void *item);

/**
 * Free the queue
 */
void        BLI_gsqueue_free(GSQueue *gq);

#endif /* __BLI_GSQUEUE_H__ */