include/sys/rbtree.h

   1 /*      $NetBSD: rbtree.h,v 1.1 2010/09/25 01:42:40 matt 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 (*const rbto_compare_nodes_fn)(void *,
 141     const void *, const void *);
 142 typedef signed int (*const rbto_compare_key_fn)(void *,
 143     const void *, const void *);
 144
 145 typedef struct {
 146         rbto_compare_nodes_fn rbto_compare_nodes;
 147         rbto_compare_key_fn rbto_compare_key;
 148         size_t rbto_node_offset;
 149         void *rbto_context;
 150 } rb_tree_ops_t;
 151
 152 typedef struct rb_tree {
 153         struct rb_node *rbt_root;
 154         const rb_tree_ops_t *rbt_ops;
 155         struct rb_node *rbt_minmax[2];
 156 #ifdef RBDEBUG
 157         struct rb_node_qh rbt_nodes;
 158 #endif
 159 #ifdef RBSTATS
 160         unsigned int rbt_count;
 161         unsigned int rbt_insertions;
 162         unsigned int rbt_removals;
 163         unsigned int rbt_insertion_rebalance_calls;
 164         unsigned int rbt_insertion_rebalance_passes;
 165         unsigned int rbt_removal_rebalance_calls;
 166         unsigned int rbt_removal_rebalance_passes;
 167 #endif
 168 } rb_tree_t;
 169
 170 #ifdef RBSTATS
 171 #define RBSTAT_INC(v)   ((void)((v)++))
 172 #define RBSTAT_DEC(v)   ((void)((v)--))
 173 #else
 174 #define RBSTAT_INC(v)   do { } while (/*CONSTCOND*/0)
 175 #define RBSTAT_DEC(v)   do { } while (/*CONSTCOND*/0)
 176 #endif
 177
 178 void    rb_tree_init(rb_tree_t *, const rb_tree_ops_t *);
 179 void *  rb_tree_insert_node(rb_tree_t *, void *);
 180 void *  rb_tree_find_node(rb_tree_t *, const void *);
 181 void *  rb_tree_find_node_geq(rb_tree_t *, const void *);
 182 void *  rb_tree_find_node_leq(rb_tree_t *, const void *);
 183 void    rb_tree_remove_node(rb_tree_t *, void *);
 184 void *  rb_tree_iterate(rb_tree_t *, void *, const unsigned int);
 185 #ifdef RBDEBUG
 186 void    rb_tree_check(const rb_tree_t *, bool);
 187 #endif
 188 #ifdef RBSTATS
 189 void    rb_tree_depths(const rb_tree_t *, size_t *);
 190 #endif
 191
 192 __END_DECLS
 193
 194 #endif  /* _SYS_RBTREE_H_*/