libretro-tyrquake/include/rb_tree.h
Kevin Shanahan 6ab27d2636 build: fix build warning on OpenBSD in rb_tree.h
OpenBSD leaks it's RB_ROOT definition from <net/if.h>, so let's rename
ours to QRB_ROOT.

Signed-off-by: Kevin Shanahan <kmshanah@disenchant.net>
2013-01-06 10:46:57 +10:30

78 lines
2.3 KiB
C

/*
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
-----------------------------------------------------------------------
To use rbtrees you'll have to implement your own insert and search cores.
This will avoid us to use callbacks and to drop drammatically performances.
I know it's not the cleaner way, but in C (not in C++) to get
performances and genericity...
Some example of insert and search follows here. The search is a plain
normal search over an ordered tree. The insert instead must be implemented
int two steps: as first thing the code must insert the element in
order as a red leaf in the tree, then the support library function
rb_insert_color() must be called. Such function will do the
not trivial work to rebalance the rbtree if necessary.
-----------------------------------------------------------------------
*/
#ifndef RB_TREE_H
#define RB_TREE_H
#include <stddef.h>
struct rb_node {
struct rb_node *rb_parent;
int rb_color;
#define QRB_RED 0
#define QRB_BLACK 1
struct rb_node *rb_right;
struct rb_node *rb_left;
};
struct rb_root {
struct rb_node *rb_node;
};
#define QRB_ROOT (struct rb_root) { NULL, }
/*
*
*/
extern void rb_insert_color(struct rb_node *, struct rb_root *);
/*
*
*/
extern void rb_erase(struct rb_node *, struct rb_root *);
static inline void
rb_link_node(struct rb_node *node, struct rb_node *parent,
struct rb_node **rb_link)
{
node->rb_parent = parent;
node->rb_color = QRB_RED;
node->rb_left = node->rb_right = NULL;
*rb_link = node;
}
#endif /* RB_TREE_H */