Branch data Line data Source code
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 : :
35 : : struct 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 : :
42 : : struct 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 : :
61 : : extern void rb_insert_color(struct rb_node *, struct rb_root *);
62 : : extern void rb_erase(struct rb_node *, struct rb_root *);
63 : :
64 : :
65 : : /* Find logical next and previous nodes in a tree */
66 : : extern struct rb_node *rb_next(const struct rb_node *);
67 : : extern struct rb_node *rb_prev(const struct rb_node *);
68 : : extern struct rb_node *rb_first(const struct rb_root *);
69 : : extern struct rb_node *rb_last(const struct rb_root *);
70 : :
71 : : /* Postorder iteration - always visit the parent after its children */
72 : : extern struct rb_node *rb_first_postorder(const struct rb_root *);
73 : : extern struct rb_node *rb_next_postorder(const struct rb_node *);
74 : :
75 : : /* Fast replacement of a single node without remove/rebalance/add/rebalance */
76 : : extern void rb_replace_node(struct rb_node *victim, struct rb_node *new,
77 : : struct rb_root *root);
78 : :
79 : : static inline void rb_link_node(struct rb_node * node, struct rb_node * parent,
80 : : struct rb_node ** rb_link)
81 : : {
82 : 85291036 : node->__rb_parent_color = (unsigned long)parent;
83 : 85291036 : node->rb_left = node->rb_right = NULL;
84 : :
85 : 85291036 : *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 */
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