libosmocore  1.5.1
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  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., 51 Franklin Street, Fifth Floor, Boston,
18  MA 02110-1301, USA.
19 
20  linux/include/linux/rbtree.h
21 
22  To use rbtrees you'll have to implement your own insert and search cores.
23  This will avoid us to use callbacks and to drop drammatically performances.
24  I know it's not the cleaner way, but in C (not in C++) to get
25  performances and genericity...
26 
27  Some example of insert and search follows here. The search is a plain
28  normal search over an ordered tree. The insert instead must be implemented
29  int two steps: as first thing the code must insert the element in
30  order as a red leaf in the tree, then the support library function
31  rb_insert_color() must be called. Such function will do the
32  not trivial work to rebalance the rbtree if necessary.
33 
34 -----------------------------------------------------------------------
35 static inline struct page * rb_search_page_cache(struct inode * inode,
36  unsigned long offset)
37 {
38  struct rb_node * n = inode->i_rb_page_cache.rb_node;
39  struct page * page;
40 
41  while (n)
42  {
43  page = rb_entry(n, struct page, rb_page_cache);
44 
45  if (offset < page->offset)
46  n = n->rb_left;
47  else if (offset > page->offset)
48  n = n->rb_right;
49  else
50  return page;
51  }
52  return NULL;
53 }
54 
55 static inline struct page * __rb_insert_page_cache(struct inode * inode,
56  unsigned long offset,
57  struct rb_node * node)
58 {
59  struct rb_node ** p = &inode->i_rb_page_cache.rb_node;
60  struct rb_node * parent = NULL;
61  struct page * page;
62 
63  while (*p)
64  {
65  parent = *p;
66  page = rb_entry(parent, struct page, rb_page_cache);
67 
68  if (offset < page->offset)
69  p = &(*p)->rb_left;
70  else if (offset > page->offset)
71  p = &(*p)->rb_right;
72  else
73  return page;
74  }
75 
76  rb_link_node(node, parent, p);
77 
78  return NULL;
79 }
80 
81 static inline struct page * rb_insert_page_cache(struct inode * inode,
82  unsigned long offset,
83  struct rb_node * node)
84 {
85  struct page * ret;
86  if ((ret = __rb_insert_page_cache(inode, offset, node)))
87  goto out;
88  rb_insert_color(node, &inode->i_rb_page_cache);
89  out:
90  return ret;
91 }
92 -----------------------------------------------------------------------
93 */
94 
95 #pragma once
96 
97 #include <stdlib.h>
98 
99 struct rb_node
100 {
101  unsigned long rb_parent_color;
102 #define RB_RED 0
103 #define RB_BLACK 1
104  struct rb_node *rb_right;
105  struct rb_node *rb_left;
106 } __attribute__((aligned(sizeof(long))));
107  /* The alignment might seem pointless, but allegedly CRIS needs it */
108 
109 struct rb_root
110 {
111  struct rb_node *rb_node;
112 };
113 
114 
115 #define rb_parent(r) ((struct rb_node *)((r)->rb_parent_color & ~3))
116 #define rb_color(r) ((r)->rb_parent_color & 1)
117 #define rb_is_red(r) (!rb_color(r))
118 #define rb_is_black(r) rb_color(r)
119 #define rb_set_red(r) do { (r)->rb_parent_color &= ~1; } while (0)
120 #define rb_set_black(r) do { (r)->rb_parent_color |= 1; } while (0)
121 
122 static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p)
123 {
124  rb->rb_parent_color = (rb->rb_parent_color & 3) | (unsigned long)p;
125 }
126 static inline void rb_set_color(struct rb_node *rb, int color)
127 {
128  rb->rb_parent_color = (rb->rb_parent_color & ~1) | color;
129 }
130 
131 #define RB_ROOT { NULL, }
132 #define rb_entry(ptr, type, member) container_of(ptr, type, member)
133 
134 #define RB_EMPTY_ROOT(root) ((root)->rb_node == NULL)
135 #define RB_EMPTY_NODE(node) (rb_parent(node) == node)
136 #define RB_CLEAR_NODE(node) (rb_set_parent(node, node))
137 
138 extern void rb_insert_color(struct rb_node *, struct rb_root *);
139 extern void rb_erase(struct rb_node *, struct rb_root *);
140 
141 /* Find logical next and previous nodes in a tree */
142 extern struct rb_node *rb_next(const struct rb_node *);
143 extern struct rb_node *rb_prev(const struct rb_node *);
144 extern struct rb_node *rb_first(const struct rb_root *);
145 extern struct rb_node *rb_last(const struct rb_root *);
146 
147 /* Fast replacement of a single node without remove/rebalance/add/rebalance */
148 extern void rb_replace_node(struct rb_node *victim, struct rb_node *_new,
149  struct rb_root *root);
150 
151 static inline void rb_link_node(struct rb_node * node, struct rb_node * parent,
152  struct rb_node ** rb_link)
153 {
154  node->rb_parent_color = (unsigned long )parent;
155  node->rb_left = node->rb_right = NULL;
156 
157  *rb_link = node;
158 }
color
static const char * color(int subsys)
Definition: logging.c:390
node
uint16_t node
rb_prev
struct rb_node * rb_prev(const struct rb_node *)
Definition: rbtree.c:341
rb_insert_color
void rb_insert_color(struct rb_node *, struct rb_root *)
Definition: rbtree.c:74
rb_root
Definition: linuxrbtree.h:110
rb_node::rb_left
struct rb_node * rb_left
Definition: linuxrbtree.h:105
rb_first
struct rb_node * rb_first(const struct rb_root *)
Definition: rbtree.c:289
__attribute__
struct rb_root __attribute__
rb_next
struct rb_node * rb_next(const struct rb_node *)
Definition: rbtree.c:313
rb_node::rb_parent_color
unsigned long rb_parent_color
Definition: linuxrbtree.h:101
rb_replace_node
void rb_replace_node(struct rb_node *victim, struct rb_node *_new, struct rb_root *root)
Definition: rbtree.c:365
rb_root::rb_node
struct rb_node * rb_node
Definition: linuxrbtree.h:111
rb_last
struct rb_node * rb_last(const struct rb_root *)
Definition: rbtree.c:301
rb_node::rb_right
struct rb_node * rb_right
Definition: linuxrbtree.h:104
rb_set_parent
static void rb_set_parent(struct rb_node *rb, struct rb_node *p)
Definition: linuxrbtree.h:122
rb_node
Definition: linuxrbtree.h:100
rb_erase
void rb_erase(struct rb_node *, struct rb_root *)
Definition: rbtree.c:219
rb_set_color
static void rb_set_color(struct rb_node *rb, int color)
Definition: linuxrbtree.h:126
rb_link_node
static void rb_link_node(struct rb_node *node, struct rb_node *parent, struct rb_node **rb_link)
Definition: linuxrbtree.h:151