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 rb_node_t * 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,
58 rb_node_t ** p = &inode->i_rb_page_cache.rb_node;
59 rb_node_t * 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,
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 typedef struct rb_node_s
99 struct rb_node_s * rb_parent;
103 struct rb_node_s * rb_right;
104 struct rb_node_s * rb_left;
108 typedef struct rb_root_s
110 struct rb_node_s * rb_node;
114 #define RB_ROOT (rb_root_t) { NULL, }
115 #define rb_entry(ptr, type, member) \
116 ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
118 extern void rb_insert_color(rb_node_t *, rb_root_t *);
119 extern void rb_erase(rb_node_t *, rb_root_t *);
120 extern rb_node_t *rb_get_first(rb_root_t *root);
121 extern rb_node_t *rb_get_next(rb_node_t *n);
123 static inline void rb_link_node(rb_node_t * node, rb_node_t * parent, rb_node_t ** rb_link)
125 node->rb_parent = parent;
126 node->rb_color = RB_RED;
127 node->rb_left = node->rb_right = NULL;
132 #endif /* _LINUX_RBTREE_H */