/*

 * Red Black Trees

 * (C) 1999  Andrea Arcangeli <andrea@suse.de>

 *

 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 */

#ifndef	NFTABLES_RBTREE_H

#define	NFTABLES_RBTREE_H

#include <stddef.h>

struct rb_node

{

	unsigned long  rb_parent_color;

#define	RB_RED		0

#define	RB_BLACK	1

	struct rb_node *rb_right;

	struct rb_node *rb_left;

};

struct rb_root

{

	struct rb_node *rb_node;

};

#define rb_parent(r)   ((struct rb_node *)((r)->rb_parent_color & ~3))

#define rb_color(r)   ((r)->rb_parent_color & 1)

#define rb_is_red(r)   (!rb_color(r))

#define rb_is_black(r) rb_color(r)

#define rb_set_red(r)  do { (r)->rb_parent_color &= ~1; } while (0)

#define rb_set_black(r)  do { (r)->rb_parent_color |= 1; } while (0)

static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p)

{

	rb->rb_parent_color = (rb->rb_parent_color & 3) | (unsigned long)p;

}

static inline void rb_set_color(struct rb_node *rb, int color)

{

	rb->rb_parent_color = (rb->rb_parent_color & ~1) | color;

}

#define RB_ROOT	(struct rb_root) { NULL, }

#define	rb_entry(ptr, type, member) container_of(ptr, type, member)

#define RB_EMPTY_ROOT(root)	((root)->rb_node == NULL)

#define RB_EMPTY_NODE(node)	(rb_parent(node) == node)

#define RB_CLEAR_NODE(node)	(rb_set_parent(node, node))

extern void rb_insert_color(struct rb_node *, struct rb_root *);

extern void rb_erase(struct rb_node *, struct rb_root *);

/* Find logical next and previous nodes in a tree */

extern struct rb_node *rb_next(struct rb_node *);

extern struct rb_node *rb_prev(struct rb_node *);

extern struct rb_node *rb_first(struct rb_root *);

extern struct rb_node *rb_last(struct rb_root *);

/* Fast replacement of a single node without remove/rebalance/add/rebalance */

extern void rb_replace_node(struct rb_node *victim, struct rb_node *new, 

			    struct rb_root *root);

static inline void rb_link_node(struct rb_node * node, struct rb_node * parent,

				struct rb_node ** rb_link)

{

	node->rb_parent_color = (unsigned long )parent;

	node->rb_left = node->rb_right = NULL;

	*rb_link = node;

}

#define rb_for_each_entry(pos, root, member) \

	for ((pos) = (root)->rb_node ? \

			rb_entry(rb_first(root), typeof(*pos), member) : NULL; \

	     (pos) != NULL; \

	     (pos) = rb_entry(rb_next(&(pos)->member), typeof(*pos), member))

#define rb_for_each_entry_safe(pos, node, next, root, member) \

	for ((node) = rb_first(root); \

	     (pos)  = (node) ? rb_entry((node), typeof(*pos), member) : NULL, \

	     (next) = (node) ? rb_next(node) : NULL, \

	     (pos) != NULL; \

	     (node) = (next))

#endif	/* NFTABLES_RBTREE_H */