mirror of
https://github.com/u-boot/u-boot.git
synced 2024-12-06 02:53:37 +08:00
7ba890bf2f
Now it's used at UBI module. Of course other modules can use it. If you want to use it, please define CONFIG_RBTREE Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
161 lines
4.8 KiB
C
161 lines
4.8 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
|
|
|
|
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)
|
|
{
|
|
struct rb_node * 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,
|
|
struct rb_node * node)
|
|
{
|
|
struct rb_node ** p = &inode->i_rb_page_cache.rb_node;
|
|
struct rb_node * 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,
|
|
struct rb_node * 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/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;
|
|
} __attribute__((aligned(sizeof(long))));
|
|
/* The alignment might seem pointless, but allegedly CRIS needs it */
|
|
|
|
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;
|
|
}
|
|
|
|
#endif /* _LINUX_RBTREE_H */
|