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/*
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
linux/include/linux/rbtree.h
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.
-----------------------------------------------------------------------
static inline struct page * rb_search_page_cache(struct inode * inode,
unsigned long offset)
{
rb_node_t * n = inode->i_rb_page_cache.rb_node;
struct page * page;
while (n)
{
page = rb_entry(n, struct page, rb_page_cache);
if (offset < page->offset)
n = n->rb_left;
else if (offset > page->offset)
n = n->rb_right;
else
return page;
}
return NULL;
}
static inline struct page * __rb_insert_page_cache(struct inode * inode,
unsigned long offset,
rb_node_t * node)
{
rb_node_t ** p = &inode->i_rb_page_cache.rb_node;
rb_node_t * parent = NULL;
struct page * page;
while (*p)
{
parent = *p;
page = rb_entry(parent, struct page, rb_page_cache);
if (offset < page->offset)
p = &(*p)->rb_left;
else if (offset > page->offset)
p = &(*p)->rb_right;
else
return page;
}
rb_link_node(node, parent, p);
return NULL;
}
static inline struct page * rb_insert_page_cache(struct inode * inode,
unsigned long offset,
rb_node_t * node)
{
struct page * ret;
if ((ret = __rb_insert_page_cache(inode, offset, node)))
goto out;
rb_insert_color(node, &inode->i_rb_page_cache);
out:
return ret;
}
-----------------------------------------------------------------------
*/
#ifndef _LINUX_RBTREE_H
#define _LINUX_RBTREE_H
#include <linux/kernel.h>
#include <linux/stddef.h>
typedef struct rb_node_s
{
struct rb_node_s * rb_parent;
int rb_color;
#define RB_RED 0
#define RB_BLACK 1
struct rb_node_s * rb_right;
struct rb_node_s * rb_left;
}
rb_node_t;
typedef struct rb_root_s
{
struct rb_node_s * rb_node;
}
rb_root_t;
#define RB_ROOT (rb_root_t) { NULL, }
#define rb_entry(ptr, type, member) \
((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
extern void rb_insert_color(rb_node_t *, rb_root_t *);
extern void rb_erase(rb_node_t *, rb_root_t *);
static inline void rb_link_node(rb_node_t * node, rb_node_t * parent, rb_node_t ** rb_link)
{
node->rb_parent = parent;
node->rb_color = RB_RED;
node->rb_left = node->rb_right = NULL;
*rb_link = node;
}
#endif /* _LINUX_RBTREE_H */
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