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