libosmocore 1.13.1.1-afb4 Osmocom core library

linuxrbtree.h
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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 linux/include/linux/rbtree.h
16
17 To use rbtrees you'll have to implement your own insert and search cores.
18 This will avoid us to use callbacks and to drop drammatically performances.
19 I know it's not the cleaner way, but in C (not in C++) to get
20 performances and genericity...
21
22 Some example of insert and search follows here. The search is a plain
23 normal search over an ordered tree. The insert instead must be implemented
24 int two steps: as first thing the code must insert the element in
25 order as a red leaf in the tree, then the support library function
26 rb_insert_color() must be called. Such function will do the
27 not trivial work to rebalance the rbtree if necessary.
28
29-----------------------------------------------------------------------
30 static inline struct page * rb_search_page_cache(struct inode * inode,
31 unsigned long offset)
32{
33 struct rb_node * n = inode->i_rb_page_cache.rb_node;
34 struct page * page;
35
36 while (n)
37 {
38 page = rb_entry(n, struct page, rb_page_cache);
39
40 if (offset < page->offset)
41 n = n->rb_left;
42 else if (offset > page->offset)
43 n = n->rb_right;
44 else
45 return page;
46 }
47 return NULL;
48}
49
50 static inline struct page * __rb_insert_page_cache(struct inode * inode,
51 unsigned long offset,
52 struct rb_node * node)
53{
54 struct rb_node ** p = &inode->i_rb_page_cache.rb_node;
55 struct rb_node * parent = NULL;
56 struct page * page;
57
58 while (*p)
59 {
60 parent = *p;
61 page = rb_entry(parent, struct page, rb_page_cache);
62
63 if (offset < page->offset)
64 p = &(*p)->rb_left;
65 else if (offset > page->offset)
66 p = &(*p)->rb_right;
67 else
68 return page;
69 }
70
71 rb_link_node(node, parent, p);
72
73 return NULL;
74}
75
76 static inline struct page * rb_insert_page_cache(struct inode * inode,
77 unsigned long offset,
78 struct rb_node * node)
79{
80 struct page * ret;
81 if ((ret = __rb_insert_page_cache(inode, offset, node)))
82 goto out;
83 rb_insert_color(node, &inode->i_rb_page_cache);
84 out:
85 return ret;
86}
87-----------------------------------------------------------------------
88*/
89
90#pragma once
91
92#include <stdlib.h>
93
94 struct rb_node
95{
96 unsigned long rb_parent_color;
97#define RB_RED 0
98#define RB_BLACK 1
99 struct rb_node *rb_right;
100 struct rb_node *rb_left;
101} __attribute__((aligned(sizeof(long))));
102 /* The alignment might seem pointless, but allegedly CRIS needs it */
103
104 struct rb_root
105{
106 struct rb_node *rb_node;
107};
108
109
110#define rb_parent(r) ((struct rb_node *)((r)->rb_parent_color & ~3))
111#define rb_color(r) ((r)->rb_parent_color & 1)
112#define rb_is_red(r) (!rb_color(r))
113#define rb_is_black(r) rb_color(r)
114#define rb_set_red(r) do { (r)->rb_parent_color &= ~1; } while (0)
115#define rb_set_black(r) do { (r)->rb_parent_color |= 1; } while (0)
116
117 static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p)
118{
119 rb->rb_parent_color = (rb->rb_parent_color & 3) | (unsigned long)p;
120}
121 static inline void rb_set_color(struct rb_node *rb, int color)
122{
123 rb->rb_parent_color = (rb->rb_parent_color & ~1) | color;
124}
125
126#define RB_ROOT { NULL, }
127#define rb_entry(ptr, type, member) container_of(ptr, type, member)
128
129#define RB_EMPTY_ROOT(root) ((root)->rb_node == NULL)
130#define RB_EMPTY_NODE(node) (rb_parent(node) == node)
131#define RB_CLEAR_NODE(node) (rb_set_parent(node, node))
132
133 extern void rb_insert_color(struct rb_node *, struct rb_root *);
134 extern void rb_erase(struct rb_node *, struct rb_root *);
135
136/* Find logical next and previous nodes in a tree */
137 extern struct rb_node *rb_next(const struct rb_node *);
138 extern struct rb_node *rb_prev(const struct rb_node *);
139 extern struct rb_node *rb_first(const struct rb_root *);
140 extern struct rb_node *rb_last(const struct rb_root *);
141
142/* Fast replacement of a single node without remove/rebalance/add/rebalance */
143 extern void rb_replace_node(struct rb_node *victim, struct rb_node *_new,
144 struct rb_root *root);
145
146 static inline void rb_link_node(struct rb_node * node, struct rb_node * parent,
147 struct rb_node ** rb_link)
148{
149 node->rb_parent_color = (unsigned long )parent;
150 node->rb_left = node->rb_right = NULL;
151
152 *rb_link = node;
153}
node
uint16_t node
color
static const char * color(int subsys)
Definition: logging.c:510
rb_set_parent
static void rb_set_parent(struct rb_node *rb, struct rb_node *p)
Definition: linuxrbtree.h:117
rb_link_node
static void rb_link_node(struct rb_node *node, struct rb_node *parent, struct rb_node **rb_link)
Definition: linuxrbtree.h:146
rb_set_color
static void rb_set_color(struct rb_node *rb, int color)
Definition: linuxrbtree.h:121
rb_next
struct rb_node * rb_next(const struct rb_node *)
Definition: rbtree.c:309
rb_insert_color
void rb_insert_color(struct rb_node *, struct rb_root *)
Definition: rbtree.c:70
rb_erase
void rb_erase(struct rb_node *, struct rb_root *)
Definition: rbtree.c:215
__attribute__
struct rb_root __attribute__
rb_replace_node
void rb_replace_node(struct rb_node *victim, struct rb_node *_new, struct rb_root *root)
Definition: rbtree.c:361
rb_first
struct rb_node * rb_first(const struct rb_root *)
Definition: rbtree.c:285
rb_prev
struct rb_node * rb_prev(const struct rb_node *)
Definition: rbtree.c:337
rb_last
struct rb_node * rb_last(const struct rb_root *)
Definition: rbtree.c:297
rb_node
Definition: linuxrbtree.h:95
rb_node::rb_parent_color
unsigned long rb_parent_color
Definition: linuxrbtree.h:96
rb_node::rb_left
struct rb_node * rb_left
Definition: linuxrbtree.h:100
rb_node::rb_right
struct rb_node * rb_right
Definition: linuxrbtree.h:99
rb_root
Definition: linuxrbtree.h:105
rb_root::rb_node
struct rb_node * rb_node
Definition: linuxrbtree.h:106