libosmocore  1.10.0.30-51bb.202411102026
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 }
uint16_t node
static const char * color(int subsys)
Definition: logging.c:510
static void rb_set_parent(struct rb_node *rb, struct rb_node *p)
Definition: linuxrbtree.h:117
struct rb_node * rb_first(const struct rb_root *)
Definition: rbtree.c:284
static void rb_link_node(struct rb_node *node, struct rb_node *parent, struct rb_node **rb_link)
Definition: linuxrbtree.h:146
static void rb_set_color(struct rb_node *rb, int color)
Definition: linuxrbtree.h:121
struct rb_node * rb_next(const struct rb_node *)
Definition: rbtree.c:308
void rb_insert_color(struct rb_node *, struct rb_root *)
Definition: rbtree.c:69
struct rb_node * rb_prev(const struct rb_node *)
Definition: rbtree.c:336
void rb_erase(struct rb_node *, struct rb_root *)
Definition: rbtree.c:214
struct rb_root __attribute__
void rb_replace_node(struct rb_node *victim, struct rb_node *_new, struct rb_root *root)
Definition: rbtree.c:360
struct rb_node * rb_last(const struct rb_root *)
Definition: rbtree.c:296
Definition: linuxrbtree.h:95
unsigned long rb_parent_color
Definition: linuxrbtree.h:96
struct rb_node * rb_left
Definition: linuxrbtree.h:100
struct rb_node * rb_right
Definition: linuxrbtree.h:99
Definition: linuxrbtree.h:105
struct rb_node * rb_node
Definition: linuxrbtree.h:106