"Fossies" - the Fresh Open Source Software Archive

Member "dhcpcd-9.4.1/compat/rbtree.h" (22 Oct 2021, 7837 Bytes) of package /linux/misc/dhcpcd-9.4.1.tar.xz:


As a special service "Fossies" has tried to format the requested source page into HTML format using (guessed) C and C++ source code syntax highlighting (style: standard) with prefixed line numbers and code folding option. Alternatively you can here view or download the uninterpreted source code file.

    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_*/