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1/*
2 Red Black Trees
3 (C) 1999 Andrea Arcangeli <andrea@suse.de>
4
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.
9
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.
14
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
18
19 linux/include/linux/rbtree.h
20
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...
25
26 See Documentation/rbtree.txt for documentation and samples.
27*/
28
29#ifndef _LINUX_RBTREE_H
30#define _LINUX_RBTREE_H
31
32#include <linux/kernel.h>
33#include <linux/stddef.h>
34
35struct rb_node {
36 unsigned long __rb_parent_color;
37 struct rb_node *rb_right;
38 struct rb_node *rb_left;
39} __attribute__((aligned(sizeof(long))));
40 /* The alignment might seem pointless, but allegedly CRIS needs it */
41
42struct rb_root {
43 struct rb_node *rb_node;
44};
45
46
47#define rb_parent(r) ((struct rb_node *)((r)->__rb_parent_color & ~3))
48
49#define RB_ROOT (struct rb_root) { NULL, }
50#define rb_entry(ptr, type, member) container_of(ptr, type, member)
51
52#define RB_EMPTY_ROOT(root) ((root)->rb_node == NULL)
53
54/* 'empty' nodes are nodes that are known not to be inserted in an rbree */
55#define RB_EMPTY_NODE(node) \
56 ((node)->__rb_parent_color == (unsigned long)(node))
57#define RB_CLEAR_NODE(node) \
58 ((node)->__rb_parent_color = (unsigned long)(node))
59
60
61extern void rb_insert_color(struct rb_node *, struct rb_root *);
62extern void rb_erase(struct rb_node *, struct rb_root *);
63
64
65/* Find logical next and previous nodes in a tree */
66extern struct rb_node *rb_next(const struct rb_node *);
67extern struct rb_node *rb_prev(const struct rb_node *);
68extern struct rb_node *rb_first(const struct rb_root *);
69extern struct rb_node *rb_last(const struct rb_root *);
70
71/* Postorder iteration - always visit the parent after its children */
72extern struct rb_node *rb_first_postorder(const struct rb_root *);
73extern struct rb_node *rb_next_postorder(const struct rb_node *);
74
75/* Fast replacement of a single node without remove/rebalance/add/rebalance */
76extern void rb_replace_node(struct rb_node *victim, struct rb_node *new,
77 struct rb_root *root);
78
79static inline void rb_link_node(struct rb_node * node, struct rb_node * parent,
80 struct rb_node ** rb_link)
81{
82 node->__rb_parent_color = (unsigned long)parent;
83 node->rb_left = node->rb_right = NULL;
84
85 *rb_link = node;
86}
87
88#define rb_entry_safe(ptr, type, member) \
89 ({ typeof(ptr) ____ptr = (ptr); \
90 ____ptr ? rb_entry(____ptr, type, member) : NULL; \
91 })
92
93/**
94 * rbtree_postorder_for_each_entry_safe - iterate over rb_root in post order of
95 * given type safe against removal of rb_node entry
96 *
97 * @pos: the 'type *' to use as a loop cursor.
98 * @n: another 'type *' to use as temporary storage
99 * @root: 'rb_root *' of the rbtree.
100 * @field: the name of the rb_node field within 'type'.
101 */
102#define rbtree_postorder_for_each_entry_safe(pos, n, root, field) \
103 for (pos = rb_entry_safe(rb_first_postorder(root), typeof(*pos), field); \
104 pos && ({ n = rb_entry_safe(rb_next_postorder(&pos->field), \
105 typeof(*pos), field); 1; }); \
106 pos = n)
107
108#endif /* _LINUX_RBTREE_H */
1/*
2 Red Black Trees
3 (C) 1999 Andrea Arcangeli <andrea@suse.de>
4
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.
9
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.
14
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
18
19 linux/include/linux/rbtree.h
20
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...
25
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 in two steps: First, the code must insert the element in order as a red leaf
29 in the tree, and then the support library function rb_insert_color() must
30 be called. Such function will do the not trivial work to rebalance the
31 rbtree, if necessary.
32
33-----------------------------------------------------------------------
34static inline struct page * rb_search_page_cache(struct inode * inode,
35 unsigned long offset)
36{
37 struct rb_node * n = inode->i_rb_page_cache.rb_node;
38 struct page * page;
39
40 while (n)
41 {
42 page = rb_entry(n, struct page, rb_page_cache);
43
44 if (offset < page->offset)
45 n = n->rb_left;
46 else if (offset > page->offset)
47 n = n->rb_right;
48 else
49 return page;
50 }
51 return NULL;
52}
53
54static inline struct page * __rb_insert_page_cache(struct inode * inode,
55 unsigned long offset,
56 struct rb_node * node)
57{
58 struct rb_node ** p = &inode->i_rb_page_cache.rb_node;
59 struct rb_node * parent = NULL;
60 struct page * page;
61
62 while (*p)
63 {
64 parent = *p;
65 page = rb_entry(parent, struct page, rb_page_cache);
66
67 if (offset < page->offset)
68 p = &(*p)->rb_left;
69 else if (offset > page->offset)
70 p = &(*p)->rb_right;
71 else
72 return page;
73 }
74
75 rb_link_node(node, parent, p);
76
77 return NULL;
78}
79
80static inline struct page * rb_insert_page_cache(struct inode * inode,
81 unsigned long offset,
82 struct rb_node * node)
83{
84 struct page * ret;
85 if ((ret = __rb_insert_page_cache(inode, offset, node)))
86 goto out;
87 rb_insert_color(node, &inode->i_rb_page_cache);
88 out:
89 return ret;
90}
91-----------------------------------------------------------------------
92*/
93
94#ifndef _LINUX_RBTREE_H
95#define _LINUX_RBTREE_H
96
97#include <linux/kernel.h>
98#include <linux/stddef.h>
99
100struct rb_node
101{
102 unsigned long rb_parent_color;
103#define RB_RED 0
104#define RB_BLACK 1
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 */
109
110struct rb_root
111{
112 struct rb_node *rb_node;
113};
114
115
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)
122
123static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p)
124{
125 rb->rb_parent_color = (rb->rb_parent_color & 3) | (unsigned long)p;
126}
127static inline void rb_set_color(struct rb_node *rb, int color)
128{
129 rb->rb_parent_color = (rb->rb_parent_color & ~1) | color;
130}
131
132#define RB_ROOT (struct rb_root) { NULL, }
133#define rb_entry(ptr, type, member) container_of(ptr, type, member)
134
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))
138
139static inline void rb_init_node(struct rb_node *rb)
140{
141 rb->rb_parent_color = 0;
142 rb->rb_right = NULL;
143 rb->rb_left = NULL;
144 RB_CLEAR_NODE(rb);
145}
146
147extern void rb_insert_color(struct rb_node *, struct rb_root *);
148extern void rb_erase(struct rb_node *, struct rb_root *);
149
150typedef void (*rb_augment_f)(struct rb_node *node, void *data);
151
152extern void rb_augment_insert(struct rb_node *node,
153 rb_augment_f func, void *data);
154extern struct rb_node *rb_augment_erase_begin(struct rb_node *node);
155extern void rb_augment_erase_end(struct rb_node *node,
156 rb_augment_f func, void *data);
157
158/* Find logical next and previous nodes in a tree */
159extern struct rb_node *rb_next(const struct rb_node *);
160extern struct rb_node *rb_prev(const struct rb_node *);
161extern struct rb_node *rb_first(const struct rb_root *);
162extern struct rb_node *rb_last(const struct rb_root *);
163
164/* Fast replacement of a single node without remove/rebalance/add/rebalance */
165extern void rb_replace_node(struct rb_node *victim, struct rb_node *new,
166 struct rb_root *root);
167
168static inline void rb_link_node(struct rb_node * node, struct rb_node * parent,
169 struct rb_node ** rb_link)
170{
171 node->rb_parent_color = (unsigned long )parent;
172 node->rb_left = node->rb_right = NULL;
173
174 *rb_link = node;
175}
176
177#endif /* _LINUX_RBTREE_H */