3 (C) 1999 Andrea Arcangeli <andrea@suse.de>
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 linux/include/linux/rbtree.h
21 To use rbtrees you'll have to implement your own insert and search cores.
22 This will avoid us to use callbacks and to drop drammatically performances.
23 I know it's not the cleaner way, but in C (not in C++) to get
24 performances and genericity...
26 Some example of insert and search follows here. The search is a plain
27 normal search over an ordered tree. The insert instead must be implemented
28 int two steps: as first thing the code must insert the element in
29 order as a red leaf in the tree, then the support library function
30 rb_insert_color() must be called. Such function will do the
31 not trivial work to rebalance the rbtree if necessary.
33 -----------------------------------------------------------------------
34 static inline struct page * rb_search_page_cache(struct inode * inode,
37 struct rb_node * n = inode->i_rb_page_cache.rb_node;
42 page = rb_entry(n, struct page, rb_page_cache);
44 if (offset < page->offset)
46 else if (offset > page->offset)
54 static inline struct page * __rb_insert_page_cache(struct inode * inode,
56 struct rb_node * node)
58 struct rb_node ** p = &inode->i_rb_page_cache.rb_node;
59 struct rb_node * parent = NULL;
65 page = rb_entry(parent, struct page, rb_page_cache);
67 if (offset < page->offset)
69 else if (offset > page->offset)
75 rb_link_node(node, parent, p);
80 static inline struct page * rb_insert_page_cache(struct inode * inode,
82 struct rb_node * node)
85 if ((ret = __rb_insert_page_cache(inode, offset, node)))
87 rb_insert_color(node, &inode->i_rb_page_cache);
91 -----------------------------------------------------------------------
94 #ifndef _LINUX_RBTREE_H
95 #define _LINUX_RBTREE_H
97 #include <linux/kernel.h>
98 #include <linux/stddef.h>
102 unsigned long rb_parent_color
;
105 struct rb_node
*rb_right
;
106 struct rb_node
*rb_left
;
107 } __attribute__((aligned(sizeof(long))));
108 /* The alignment might seem pointless, but allegedly CRIS needs it */
112 struct rb_node
*rb_node
;
116 #define rb_parent(r) ((struct rb_node *)((r)->rb_parent_color & ~3))
117 #define rb_color(r) ((r)->rb_parent_color & 1)
118 #define rb_is_red(r) (!rb_color(r))
119 #define rb_is_black(r) rb_color(r)
120 #define rb_set_red(r) do { (r)->rb_parent_color &= ~1; } while (0)
121 #define rb_set_black(r) do { (r)->rb_parent_color |= 1; } while (0)
123 static inline void rb_set_parent(struct rb_node
*rb
, struct rb_node
*p
)
125 rb
->rb_parent_color
= (rb
->rb_parent_color
& 3) | (unsigned long)p
;
127 static inline void rb_set_color(struct rb_node
*rb
, int color
)
129 rb
->rb_parent_color
= (rb
->rb_parent_color
& ~1) | color
;
132 #define RB_ROOT (struct rb_root) { NULL, }
133 #define rb_entry(ptr, type, member) container_of(ptr, type, member)
135 #define RB_EMPTY_ROOT(root) ((root)->rb_node == NULL)
136 #define RB_EMPTY_NODE(node) (rb_parent(node) == node)
137 #define RB_CLEAR_NODE(node) (rb_set_parent(node, node))
139 extern void rb_insert_color(struct rb_node
*, struct rb_root
*);
140 extern void rb_erase(struct rb_node
*, struct rb_root
*);
142 /* Find logical next and previous nodes in a tree */
143 extern struct rb_node
*rb_next(struct rb_node
*);
144 extern struct rb_node
*rb_prev(struct rb_node
*);
145 extern struct rb_node
*rb_first(struct rb_root
*);
146 extern struct rb_node
*rb_last(struct rb_root
*);
148 /* Fast replacement of a single node without remove/rebalance/add/rebalance */
149 extern void rb_replace_node(struct rb_node
*victim
, struct rb_node
*new,
150 struct rb_root
*root
);
152 static inline void rb_link_node(struct rb_node
* node
, struct rb_node
* parent
,
153 struct rb_node
** rb_link
)
155 node
->rb_parent_color
= (unsigned long )parent
;
156 node
->rb_left
= node
->rb_right
= NULL
;
161 #endif /* _LINUX_RBTREE_H */
This page took 0.039911 seconds and 5 git commands to generate.