/*
 * ***** 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_LINKLIST_STACK_H__
#define __BLI_LINKLIST_STACK_H__

/** \file BLI_linklist_stack.h
 * \ingroup bli
 * \brief BLI_LINKSTACK_*** wrapper macros for using a \a LinkNode
 *        to store a stack of pointers, using a single linked list
 *        allocated from a mempool.
 *
 * \note These macros follow STACK_* macros defined in 'BLI_utildefines.h'
 *       and should be kept (mostly) interchangeable.
 *
 * \note ``_##var##_type`` is a dummy variable only used for typechecks.
 */

/* -------------------------------------------------------------------- */
/* Linked Stack using BLI_mempool
 *
 * Uses mempool for storage.
 */

/** \name Linked Stack (mempool)
 * \{ */

#define BLI_LINKSTACK_DECLARE(var, type) \
	LinkNode *var; \
	BLI_mempool *var##_pool_; \
	type var##_type_

#define BLI_LINKSTACK_INIT(var)  { \
	var = NULL; \
	var##_pool_ = BLI_mempool_create(sizeof(LinkNode), 0, 64, BLI_MEMPOOL_NOP); \
} (void)0

#define BLI_LINKSTACK_SIZE(var) \
	BLI_mempool_count(var##_pool_)

/* check for typeof() */
#ifdef __GNUC__
#define BLI_LINKSTACK_PUSH(var, ptr)  ( \
	CHECK_TYPE_INLINE(ptr, typeof(var##_type_)), \
	BLI_linklist_prepend_pool(&(var), ptr, var##_pool_))
#define BLI_LINKSTACK_POP(var) \
	(var ? (typeof(var##_type_))BLI_linklist_pop_pool(&(var), var##_pool_) : NULL)
#define BLI_LINKSTACK_POP_DEFAULT(var, r) \
	(var ? (typeof(var##_type_))BLI_linklist_pop_pool(&(var), var##_pool_) : r)
#else  /* non gcc */
#define BLI_LINKSTACK_PUSH(var, ptr)  ( \
	BLI_linklist_prepend_pool(&(var), ptr, var##_pool_))
#define BLI_LINKSTACK_POP(var) \
	(var ? BLI_linklist_pop_pool(&(var), var##_pool_) : NULL)
#define BLI_LINKSTACK_POP_DEFAULT(var, r) \
	(var ? BLI_linklist_pop_pool(&(var), var##_pool_) : r)
#endif  /* gcc check */

#define BLI_LINKSTACK_SWAP(var_a, var_b)  { \
	CHECK_TYPE_PAIR(var_a##_type_, var_b##_type_); \
	SWAP(LinkNode *, var_a, var_b); \
	SWAP(BLI_mempool *, var_a##_pool_, var_b##_pool_); \
} (void)0

#define BLI_LINKSTACK_FREE(var)  { \
	BLI_mempool_destroy(var##_pool_); \
	var##_pool_ = NULL; (void)var##_pool_; \
	var = NULL; (void)var; \
	(void)&(var##_type_); \
} (void)0

#include "BLI_linklist.h"
#include "BLI_mempool.h"

/** \} */


/* -------------------------------------------------------------------- */
/* Linked Stack, using stack memory (alloca)
 *
 * alloca never frees, pop'd items are stored in a free-list for reuse.
 * only use for lists small enough to fit on the stack.
 */


/** \name Linked Stack (alloca)
 * \{ */

#ifdef __GNUC__
#  define _BLI_SMALLSTACK_CAST(var) (typeof(_##var##_type))
#else
#  define _BLI_SMALLSTACK_CAST(var)
#endif

#define _BLI_SMALLSTACK_FAKEUSER(var) \
	(void)(&(_##var##_type))

#define BLI_SMALLSTACK_DECLARE(var, type) \
	LinkNode *_##var##_stack = NULL, *_##var##_free = NULL, *_##var##_temp = NULL; \
	type _##var##_type

#define BLI_SMALLSTACK_PUSH(var, data) \
{ \
	CHECK_TYPE_PAIR(data, _##var##_type); \
	if (_##var##_free) { \
		_##var##_temp = _##var##_free; \
		_##var##_free = _##var##_free->next; \
	} \
	else { \
		_##var##_temp = alloca(sizeof(LinkNode)); \
	} \
	_##var##_temp->next = _##var##_stack; \
	_##var##_temp->link = data; \
	_##var##_stack = _##var##_temp; \
	_BLI_SMALLSTACK_FAKEUSER(var); \
} (void)0

/* internal use, no null check */
#define _BLI_SMALLSTACK_DEL_EX(var_src, var_dst) \
	(void)(_BLI_SMALLSTACK_FAKEUSER(var_src), \
	       _BLI_SMALLSTACK_FAKEUSER(var_dst), \
	       (_##var_src##_temp = _##var_src##_stack->next), \
	       (_##var_src##_stack->next = _##var_dst##_free), \
	       (_##var_dst##_free = _##var_src##_stack), \
	       (_##var_src##_stack = _##var_src##_temp)) \

#define _BLI_SMALLSTACK_DEL(var) \
	_BLI_SMALLSTACK_DEL_EX(var, var) \

/* check for typeof() */
#define BLI_SMALLSTACK_POP(var) \
	(_BLI_SMALLSTACK_CAST(var) ((_##var##_stack) ? \
	(_BLI_SMALLSTACK_DEL(var), (_##var##_free->link)) : NULL))

/* support to put the free-node into another stack */
#define BLI_SMALLSTACK_POP_EX(var_src, var_dst) \
	(_BLI_SMALLSTACK_CAST(var_src) ((_##var_src##_stack) ? \
	(_BLI_SMALLSTACK_DEL_EX(var_src, var_dst), (_##var_dst##_free->link)) : NULL))

#define BLI_SMALLSTACK_PEEK(var) \
	(_BLI_SMALLSTACK_CAST(var) ((_##var##_stack) ? \
	                             _##var##_stack->link : NULL))

#define BLI_SMALLSTACK_IS_EMPTY(var) \
	((_BLI_SMALLSTACK_CAST(var) _##var##_stack) == NULL)

/* fill in a lookup table */
#define BLI_SMALLSTACK_AS_TABLE(var, data) \
{ \
	LinkNode *_##var##_iter; \
	unsigned int i; \
	for (_##var##_iter = _##var##_stack, i = 0; _##var##_iter; _##var##_iter = _##var##_iter->next, i++) { \
		(data)[i] = _BLI_SMALLSTACK_CAST(var) (_##var##_iter->link); \
	} \
} ((void)0)

/* loop over stack members last-added-first */
#define BLI_SMALLSTACK_ITER_BEGIN(var, item) \
	{ \
		LinkNode *_##var##_iter; \
		for (_##var##_iter = _##var##_stack; _##var##_iter; _##var##_iter = _##var##_iter->next) { \
			item = _BLI_SMALLSTACK_CAST(var) (_##var##_iter->link); \

#define BLI_SMALLSTACK_ITER_END \
		} \
	} (void)0

#define BLI_SMALLSTACK_SWAP(var_a, var_b) \
{ \
	CHECK_TYPE_PAIR(_##var_a##_type, _##var_b##_type); \
	SWAP(LinkNode *, _##var_a##_stack, _##var_b##_stack); \
	SWAP(LinkNode *, _##var_a##_free, _##var_b##_free); \
} (void)0

/** \} */

#endif  /* __BLI_LINKLIST_STACK_H__ */

