1 /*	$NetBSD: rbtree.h,v 1.2 2012/02/17 08:20:55 yamt Exp $	*/
2 
3 /*-
4  * Copyright (c) 2001 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Matt Thomas <matt@3am-software.com>.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #ifndef _SYS_RBTREE_H_
33 #define	_SYS_RBTREE_H_
34 
35 #if defined(_KERNEL) || defined(_STANDALONE)
36 #include <sys/types.h>
37 #else
38 #include <stdbool.h>
39 #include <inttypes.h>
40 #endif
41 #include <sys/queue.h>
42 #include <sys/endian.h>
43 
44 __BEGIN_DECLS
45 
46 typedef struct rb_node {
47 	struct rb_node *rb_nodes[2];
48 #define	RB_DIR_LEFT		0
49 #define	RB_DIR_RIGHT		1
50 #define	RB_DIR_OTHER		1
51 #define	rb_left			rb_nodes[RB_DIR_LEFT]
52 #define	rb_right		rb_nodes[RB_DIR_RIGHT]
53 
54 	/*
55 	 * rb_info contains the two flags and the parent back pointer.
56 	 * We put the two flags in the low two bits since we know that
57 	 * rb_node will have an alignment of 4 or 8 bytes.
58 	 */
59 	uintptr_t rb_info;
60 #define	RB_FLAG_POSITION	0x2
61 #define	RB_FLAG_RED		0x1
62 #define	RB_FLAG_MASK		(RB_FLAG_POSITION|RB_FLAG_RED)
63 #define	RB_FATHER(rb) \
64     ((struct rb_node *)((rb)->rb_info & ~RB_FLAG_MASK))
65 #define	RB_SET_FATHER(rb, father) \
66     ((void)((rb)->rb_info = (uintptr_t)(father)|((rb)->rb_info & RB_FLAG_MASK)))
67 
68 #define	RB_SENTINEL_P(rb)	((rb) == NULL)
69 #define	RB_LEFT_SENTINEL_P(rb)	RB_SENTINEL_P((rb)->rb_left)
70 #define	RB_RIGHT_SENTINEL_P(rb)	RB_SENTINEL_P((rb)->rb_right)
71 #define	RB_FATHER_SENTINEL_P(rb) RB_SENTINEL_P(RB_FATHER((rb)))
72 #define	RB_CHILDLESS_P(rb) \
73     (RB_SENTINEL_P(rb) || (RB_LEFT_SENTINEL_P(rb) && RB_RIGHT_SENTINEL_P(rb)))
74 #define	RB_TWOCHILDREN_P(rb) \
75     (!RB_SENTINEL_P(rb) && !RB_LEFT_SENTINEL_P(rb) && !RB_RIGHT_SENTINEL_P(rb))
76 
77 #define	RB_POSITION(rb)	\
78     (((rb)->rb_info & RB_FLAG_POSITION) ? RB_DIR_RIGHT : RB_DIR_LEFT)
79 #define	RB_RIGHT_P(rb)		(RB_POSITION(rb) == RB_DIR_RIGHT)
80 #define	RB_LEFT_P(rb)		(RB_POSITION(rb) == RB_DIR_LEFT)
81 #define	RB_RED_P(rb) 		(!RB_SENTINEL_P(rb) && ((rb)->rb_info & RB_FLAG_RED) != 0)
82 #define	RB_BLACK_P(rb) 		(RB_SENTINEL_P(rb) || ((rb)->rb_info & RB_FLAG_RED) == 0)
83 #define	RB_MARK_RED(rb) 	((void)((rb)->rb_info |= RB_FLAG_RED))
84 #define	RB_MARK_BLACK(rb) 	((void)((rb)->rb_info &= ~RB_FLAG_RED))
85 #define	RB_INVERT_COLOR(rb) 	((void)((rb)->rb_info ^= RB_FLAG_RED))
86 #define	RB_ROOT_P(rbt, rb)	((rbt)->rbt_root == (rb))
87 #define	RB_SET_POSITION(rb, position) \
88     ((void)((position) ? ((rb)->rb_info |= RB_FLAG_POSITION) : \
89     ((rb)->rb_info &= ~RB_FLAG_POSITION)))
90 #define	RB_ZERO_PROPERTIES(rb)	((void)((rb)->rb_info &= ~RB_FLAG_MASK))
91 #define	RB_COPY_PROPERTIES(dst, src) \
92     ((void)((dst)->rb_info ^= ((dst)->rb_info ^ (src)->rb_info) & RB_FLAG_MASK))
93 #define RB_SWAP_PROPERTIES(a, b) do { \
94     uintptr_t xorinfo = ((a)->rb_info ^ (b)->rb_info) & RB_FLAG_MASK; \
95     (a)->rb_info ^= xorinfo; \
96     (b)->rb_info ^= xorinfo; \
97   } while (/*CONSTCOND*/ 0)
98 #ifdef RBDEBUG
99 	TAILQ_ENTRY(rb_node) rb_link;
100 #endif
101 } rb_node_t;
102 
103 #define RB_TREE_MIN(T) rb_tree_iterate((T), NULL, RB_DIR_LEFT)
104 #define RB_TREE_MAX(T) rb_tree_iterate((T), NULL, RB_DIR_RIGHT)
105 #define RB_TREE_FOREACH(N, T) \
106     for ((N) = RB_TREE_MIN(T); (N); \
107 	(N) = rb_tree_iterate((T), (N), RB_DIR_RIGHT))
108 #define RB_TREE_FOREACH_REVERSE(N, T) \
109     for ((N) = RB_TREE_MAX(T); (N); \
110 	(N) = rb_tree_iterate((T), (N), RB_DIR_LEFT))
111 
112 #ifdef RBDEBUG
113 TAILQ_HEAD(rb_node_qh, rb_node);
114 
115 #define	RB_TAILQ_REMOVE(a, b, c)		TAILQ_REMOVE(a, b, c)
116 #define	RB_TAILQ_INIT(a)			TAILQ_INIT(a)
117 #define	RB_TAILQ_INSERT_HEAD(a, b, c)		TAILQ_INSERT_HEAD(a, b, c)
118 #define	RB_TAILQ_INSERT_BEFORE(a, b, c)		TAILQ_INSERT_BEFORE(a, b, c)
119 #define	RB_TAILQ_INSERT_AFTER(a, b, c, d)	TAILQ_INSERT_AFTER(a, b, c, d)
120 #else
121 #define	RB_TAILQ_REMOVE(a, b, c)		do { } while (/*CONSTCOND*/0)
122 #define	RB_TAILQ_INIT(a)			do { } while (/*CONSTCOND*/0)
123 #define	RB_TAILQ_INSERT_HEAD(a, b, c)		do { } while (/*CONSTCOND*/0)
124 #define	RB_TAILQ_INSERT_BEFORE(a, b, c)		do { } while (/*CONSTCOND*/0)
125 #define	RB_TAILQ_INSERT_AFTER(a, b, c, d)	do { } while (/*CONSTCOND*/0)
126 #endif /* RBDEBUG */
127 
128 /*
129  * rbto_compare_nodes_fn:
130  *	return a positive value if the first node > the second node.
131  *	return a negative value if the first node < the second node.
132  *	return 0 if they are considered same.
133  *
134  * rbto_compare_key_fn:
135  *	return a positive value if the node > the key.
136  *	return a negative value if the node < the key.
137  *	return 0 if they are considered same.
138  */
139 
140 typedef signed int (*rbto_compare_nodes_fn)(void *, const void *, const void *);
141 typedef signed int (*rbto_compare_key_fn)(void *, const void *, const void *);
142 
143 typedef struct {
144 	rbto_compare_nodes_fn rbto_compare_nodes;
145 	rbto_compare_key_fn rbto_compare_key;
146 	size_t rbto_node_offset;
147 	void *rbto_context;
148 } rb_tree_ops_t;
149 
150 typedef struct rb_tree {
151 	struct rb_node *rbt_root;
152 	const rb_tree_ops_t *rbt_ops;
153 	struct rb_node *rbt_minmax[2];
154 #ifdef RBDEBUG
155 	struct rb_node_qh rbt_nodes;
156 #endif
157 #ifdef RBSTATS
158 	unsigned int rbt_count;
159 	unsigned int rbt_insertions;
160 	unsigned int rbt_removals;
161 	unsigned int rbt_insertion_rebalance_calls;
162 	unsigned int rbt_insertion_rebalance_passes;
163 	unsigned int rbt_removal_rebalance_calls;
164 	unsigned int rbt_removal_rebalance_passes;
165 #endif
166 } rb_tree_t;
167 
168 #ifdef RBSTATS
169 #define	RBSTAT_INC(v)	((void)((v)++))
170 #define	RBSTAT_DEC(v)	((void)((v)--))
171 #else
172 #define	RBSTAT_INC(v)	do { } while (/*CONSTCOND*/0)
173 #define	RBSTAT_DEC(v)	do { } while (/*CONSTCOND*/0)
174 #endif
175 
176 void	rb_tree_init(rb_tree_t *, const rb_tree_ops_t *);
177 void *	rb_tree_insert_node(rb_tree_t *, void *);
178 void *	rb_tree_find_node(rb_tree_t *, const void *);
179 void *	rb_tree_find_node_geq(rb_tree_t *, const void *);
180 void *	rb_tree_find_node_leq(rb_tree_t *, const void *);
181 void	rb_tree_remove_node(rb_tree_t *, void *);
182 void *	rb_tree_iterate(rb_tree_t *, void *, const unsigned int);
183 #ifdef RBDEBUG
184 void	rb_tree_check(const rb_tree_t *, bool);
185 #endif
186 #ifdef RBSTATS
187 void	rb_tree_depths(const rb_tree_t *, size_t *);
188 #endif
189 
190 __END_DECLS
191 
192 #endif	/* _SYS_RBTREE_H_*/
193