xref: /dragonfly/contrib/dhcpcd/compat/rbtree.h (revision 5fb3968e)
1 /*	$NetBSD: rbtree.h,v 1.5 2019/03/07 14:39:21 roy 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 #include "config.h"
36 #include "common.h"
37 
38 #if defined(_KERNEL) || defined(_STANDALONE)
39 #include <sys/types.h>
40 #else
41 #include <stdbool.h>
42 #include <inttypes.h>
43 #endif
44 #ifdef HAVE_SYS_QUEUE_H
45 #include <sys/queue.h>
46 #else
47 #include "queue.h"
48 #endif
49 #if !defined(__linux__) && !defined(__QNX__) && !defined(__sun)
50 #include <sys/endian.h>
51 #else
52 #include "endian.h"
53 #endif
54 
55 __BEGIN_DECLS
56 
57 typedef struct rb_node {
58 	struct rb_node *rb_nodes[2];
59 #define	RB_DIR_LEFT		0
60 #define	RB_DIR_RIGHT		1
61 #define	RB_DIR_OTHER		1
62 #define	rb_left			rb_nodes[RB_DIR_LEFT]
63 #define	rb_right		rb_nodes[RB_DIR_RIGHT]
64 
65 	/*
66 	 * rb_info contains the two flags and the parent back pointer.
67 	 * We put the two flags in the low two bits since we know that
68 	 * rb_node will have an alignment of 4 or 8 bytes.
69 	 */
70 	uintptr_t rb_info;
71 #define	RB_FLAG_POSITION	(uintptr_t)0x2
72 #define	RB_FLAG_RED		(uintptr_t)0x1
73 #define	RB_FLAG_MASK		(RB_FLAG_POSITION|RB_FLAG_RED)
74 #define	RB_FATHER(rb) \
75     ((struct rb_node *)((rb)->rb_info & ~RB_FLAG_MASK))
76 #define	RB_SET_FATHER(rb, father) \
77     ((void)((rb)->rb_info = (uintptr_t)(father)|((rb)->rb_info & RB_FLAG_MASK)))
78 
79 #define	RB_SENTINEL_P(rb)	((rb) == NULL)
80 #define	RB_LEFT_SENTINEL_P(rb)	RB_SENTINEL_P((rb)->rb_left)
81 #define	RB_RIGHT_SENTINEL_P(rb)	RB_SENTINEL_P((rb)->rb_right)
82 #define	RB_FATHER_SENTINEL_P(rb) RB_SENTINEL_P(RB_FATHER((rb)))
83 #define	RB_CHILDLESS_P(rb) \
84     (RB_SENTINEL_P(rb) || (RB_LEFT_SENTINEL_P(rb) && RB_RIGHT_SENTINEL_P(rb)))
85 #define	RB_TWOCHILDREN_P(rb) \
86     (!RB_SENTINEL_P(rb) && !RB_LEFT_SENTINEL_P(rb) && !RB_RIGHT_SENTINEL_P(rb))
87 
88 #define	RB_POSITION(rb)	\
89     (((rb)->rb_info & RB_FLAG_POSITION) ? RB_DIR_RIGHT : RB_DIR_LEFT)
90 #define	RB_RIGHT_P(rb)		(RB_POSITION(rb) == RB_DIR_RIGHT)
91 #define	RB_LEFT_P(rb)		(RB_POSITION(rb) == RB_DIR_LEFT)
92 #define	RB_RED_P(rb) 		(!RB_SENTINEL_P(rb) && ((rb)->rb_info & RB_FLAG_RED) != 0)
93 #define	RB_BLACK_P(rb) 		(RB_SENTINEL_P(rb) || ((rb)->rb_info & RB_FLAG_RED) == 0)
94 #define	RB_MARK_RED(rb) 	((void)((rb)->rb_info |= RB_FLAG_RED))
95 #define	RB_MARK_BLACK(rb) 	((void)((rb)->rb_info &= ~RB_FLAG_RED))
96 #define	RB_INVERT_COLOR(rb) 	((void)((rb)->rb_info ^= RB_FLAG_RED))
97 #define	RB_ROOT_P(rbt, rb)	((rbt)->rbt_root == (rb))
98 #define	RB_SET_POSITION(rb, position) \
99     ((void)((position) ? ((rb)->rb_info |= RB_FLAG_POSITION) : \
100     ((rb)->rb_info &= ~RB_FLAG_POSITION)))
101 #define	RB_ZERO_PROPERTIES(rb)	((void)((rb)->rb_info &= ~RB_FLAG_MASK))
102 #define	RB_COPY_PROPERTIES(dst, src) \
103     ((void)((dst)->rb_info ^= ((dst)->rb_info ^ (src)->rb_info) & RB_FLAG_MASK))
104 #define RB_SWAP_PROPERTIES(a, b) do { \
105     uintptr_t xorinfo = ((a)->rb_info ^ (b)->rb_info) & RB_FLAG_MASK; \
106     (a)->rb_info ^= xorinfo; \
107     (b)->rb_info ^= xorinfo; \
108   } while (/*CONSTCOND*/ 0)
109 #ifdef RBDEBUG
110 	TAILQ_ENTRY(rb_node) rb_link;
111 #endif
112 } rb_node_t;
113 
114 #define RB_TREE_MIN(T) rb_tree_iterate((T), NULL, RB_DIR_LEFT)
115 #define RB_TREE_MAX(T) rb_tree_iterate((T), NULL, RB_DIR_RIGHT)
116 #define RB_TREE_NEXT(T, N) rb_tree_iterate((T), (N), RB_DIR_RIGHT)
117 #define RB_TREE_PREV(T, N) rb_tree_iterate((T), (N), RB_DIR_LEFT)
118 #define RB_TREE_FOREACH(N, T) \
119     for ((N) = RB_TREE_MIN(T); (N); (N) = RB_TREE_NEXT((T), (N)))
120 #define RB_TREE_FOREACH_REVERSE(N, T) \
121     for ((N) = RB_TREE_MAX(T); (N); (N) = RB_TREE_PREV((T), (N)))
122 #define RB_TREE_FOREACH_SAFE(N, T, S) \
123     for ((N) = RB_TREE_MIN(T); \
124         (N) && ((S) = RB_TREE_NEXT((T), (N)), 1); \
125         (N) = (S))
126 #define RB_TREE_FOREACH_REVERSE_SAFE(N, T, S) \
127     for ((N) = RB_TREE_MAX(T); \
128         (N) && ((S) = RB_TREE_PREV((T), (N)), 1); \
129         (N) = (S))
130 
131 #ifdef RBDEBUG
132 TAILQ_HEAD(rb_node_qh, rb_node);
133 
134 #define	RB_TAILQ_REMOVE(a, b, c)		TAILQ_REMOVE(a, b, c)
135 #define	RB_TAILQ_INIT(a)			TAILQ_INIT(a)
136 #define	RB_TAILQ_INSERT_HEAD(a, b, c)		TAILQ_INSERT_HEAD(a, b, c)
137 #define	RB_TAILQ_INSERT_BEFORE(a, b, c)		TAILQ_INSERT_BEFORE(a, b, c)
138 #define	RB_TAILQ_INSERT_AFTER(a, b, c, d)	TAILQ_INSERT_AFTER(a, b, c, d)
139 #else
140 #define	RB_TAILQ_REMOVE(a, b, c)		do { } while (/*CONSTCOND*/0)
141 #define	RB_TAILQ_INIT(a)			do { } while (/*CONSTCOND*/0)
142 #define	RB_TAILQ_INSERT_HEAD(a, b, c)		do { } while (/*CONSTCOND*/0)
143 #define	RB_TAILQ_INSERT_BEFORE(a, b, c)		do { } while (/*CONSTCOND*/0)
144 #define	RB_TAILQ_INSERT_AFTER(a, b, c, d)	do { } while (/*CONSTCOND*/0)
145 #endif /* RBDEBUG */
146 
147 /*
148  * rbto_compare_nodes_fn:
149  *	return a positive value if the first node > the second node.
150  *	return a negative value if the first node < the second node.
151  *	return 0 if they are considered same.
152  *
153  * rbto_compare_key_fn:
154  *	return a positive value if the node > the key.
155  *	return a negative value if the node < the key.
156  *	return 0 if they are considered same.
157  */
158 
159 typedef signed int (*rbto_compare_nodes_fn)(void *, const void *, const void *);
160 typedef signed int (*rbto_compare_key_fn)(void *, const void *, const void *);
161 
162 typedef struct {
163 	rbto_compare_nodes_fn rbto_compare_nodes;
164 	rbto_compare_key_fn rbto_compare_key;
165 	size_t rbto_node_offset;
166 	void *rbto_context;
167 } rb_tree_ops_t;
168 
169 typedef struct rb_tree {
170 	struct rb_node *rbt_root;
171 	const rb_tree_ops_t *rbt_ops;
172 	struct rb_node *rbt_minmax[2];
173 #ifdef RBDEBUG
174 	struct rb_node_qh rbt_nodes;
175 #endif
176 #ifdef RBSTATS
177 	unsigned int rbt_count;
178 	unsigned int rbt_insertions;
179 	unsigned int rbt_removals;
180 	unsigned int rbt_insertion_rebalance_calls;
181 	unsigned int rbt_insertion_rebalance_passes;
182 	unsigned int rbt_removal_rebalance_calls;
183 	unsigned int rbt_removal_rebalance_passes;
184 #endif
185 } rb_tree_t;
186 
187 #ifdef RBSTATS
188 #define	RBSTAT_INC(v)	((void)((v)++))
189 #define	RBSTAT_DEC(v)	((void)((v)--))
190 #else
191 #define	RBSTAT_INC(v)	do { } while (/*CONSTCOND*/0)
192 #define	RBSTAT_DEC(v)	do { } while (/*CONSTCOND*/0)
193 #endif
194 
195 void	rb_tree_init(rb_tree_t *, const rb_tree_ops_t *);
196 void *	rb_tree_insert_node(rb_tree_t *, void *);
197 void *	rb_tree_find_node(rb_tree_t *, const void *);
198 void *	rb_tree_find_node_geq(rb_tree_t *, const void *);
199 void *	rb_tree_find_node_leq(rb_tree_t *, const void *);
200 void	rb_tree_remove_node(rb_tree_t *, void *);
201 void *	rb_tree_iterate(rb_tree_t *, void *, const unsigned int);
202 #ifdef RBDEBUG
203 void	rb_tree_check(const rb_tree_t *, bool);
204 #endif
205 #ifdef RBSTATS
206 void	rb_tree_depths(const rb_tree_t *, size_t *);
207 #endif
208 
209 __END_DECLS
210 
211 #endif	/* _SYS_RBTREE_H_*/
212