LCOM1920-T02G10

/*        $NetBSD: rbtree.h,v 1.2 2012/02/17 08:20:55 yamt Exp $        */

/*-

 * Copyright (c) 2001 The NetBSD Foundation, Inc.

 * All rights reserved.

 *

 * This code is derived from software contributed to The NetBSD Foundation

 * by Matt Thomas <matt@3am-software.com>.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS

 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED

 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS

 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

 * POSSIBILITY OF SUCH DAMAGE.

 */

#ifndef _SYS_RBTREE_H_

#define        _SYS_RBTREE_H_

#if defined(_KERNEL) || defined(_STANDALONE)

#include <sys/types.h>

#else

#include <stdbool.h>

#include <inttypes.h>

#endif

#include <sys/queue.h>

#include <sys/endian.h>

__BEGIN_DECLS

typedef struct rb_node {

        struct rb_node *rb_nodes[2];

#define        RB_DIR_LEFT                0

#define        RB_DIR_RIGHT                1

#define        RB_DIR_OTHER                1

#define        rb_left                        rb_nodes[RB_DIR_LEFT]

#define        rb_right                rb_nodes[RB_DIR_RIGHT]

        /*

         * rb_info contains the two flags and the parent back pointer.

         * We put the two flags in the low two bits since we know that

         * rb_node will have an alignment of 4 or 8 bytes.

         */

        uintptr_t rb_info;

#define        RB_FLAG_POSITION        0x2

#define        RB_FLAG_RED                0x1

#define        RB_FLAG_MASK                (RB_FLAG_POSITION|RB_FLAG_RED)

#define        RB_FATHER(rb) \

    ((struct rb_node *)((rb)->rb_info & ~RB_FLAG_MASK))

#define        RB_SET_FATHER(rb, father) \

    ((void)((rb)->rb_info = (uintptr_t)(father)|((rb)->rb_info & RB_FLAG_MASK)))

#define        RB_SENTINEL_P(rb)        ((rb) == NULL)

#define        RB_LEFT_SENTINEL_P(rb)        RB_SENTINEL_P((rb)->rb_left)

#define        RB_RIGHT_SENTINEL_P(rb)        RB_SENTINEL_P((rb)->rb_right)

#define        RB_FATHER_SENTINEL_P(rb) RB_SENTINEL_P(RB_FATHER((rb)))

#define        RB_CHILDLESS_P(rb) \

    (RB_SENTINEL_P(rb) || (RB_LEFT_SENTINEL_P(rb) && RB_RIGHT_SENTINEL_P(rb)))

#define        RB_TWOCHILDREN_P(rb) \

    (!RB_SENTINEL_P(rb) && !RB_LEFT_SENTINEL_P(rb) && !RB_RIGHT_SENTINEL_P(rb))

#define        RB_POSITION(rb)        \

    (((rb)->rb_info & RB_FLAG_POSITION) ? RB_DIR_RIGHT : RB_DIR_LEFT)

#define        RB_RIGHT_P(rb)                (RB_POSITION(rb) == RB_DIR_RIGHT)

#define        RB_LEFT_P(rb)                (RB_POSITION(rb) == RB_DIR_LEFT)

#define        RB_RED_P(rb)                 (!RB_SENTINEL_P(rb) && ((rb)->rb_info & RB_FLAG_RED) != 0)

#define        RB_BLACK_P(rb)                 (RB_SENTINEL_P(rb) || ((rb)->rb_info & RB_FLAG_RED) == 0)

#define        RB_MARK_RED(rb)         ((void)((rb)->rb_info |= RB_FLAG_RED))

#define        RB_MARK_BLACK(rb)         ((void)((rb)->rb_info &= ~RB_FLAG_RED))

#define        RB_INVERT_COLOR(rb)         ((void)((rb)->rb_info ^= RB_FLAG_RED))

#define        RB_ROOT_P(rbt, rb)        ((rbt)->rbt_root == (rb))

#define        RB_SET_POSITION(rb, position) \

    ((void)((position) ? ((rb)->rb_info |= RB_FLAG_POSITION) : \

    ((rb)->rb_info &= ~RB_FLAG_POSITION)))

#define        RB_ZERO_PROPERTIES(rb)        ((void)((rb)->rb_info &= ~RB_FLAG_MASK))

#define        RB_COPY_PROPERTIES(dst, src) \

    ((void)((dst)->rb_info ^= ((dst)->rb_info ^ (src)->rb_info) & RB_FLAG_MASK))

#define RB_SWAP_PROPERTIES(a, b) do { \

    uintptr_t xorinfo = ((a)->rb_info ^ (b)->rb_info) & RB_FLAG_MASK; \

    (a)->rb_info ^= xorinfo; \

    (b)->rb_info ^= xorinfo; \

  } while (/*CONSTCOND*/ 0)

#ifdef RBDEBUG

        TAILQ_ENTRY(rb_node) rb_link;

#endif

} rb_node_t;

#define RB_TREE_MIN(T) rb_tree_iterate((T), NULL, RB_DIR_LEFT)

#define RB_TREE_MAX(T) rb_tree_iterate((T), NULL, RB_DIR_RIGHT)

#define RB_TREE_FOREACH(N, T) \

    for ((N) = RB_TREE_MIN(T); (N); \

        (N) = rb_tree_iterate((T), (N), RB_DIR_RIGHT))

#define RB_TREE_FOREACH_REVERSE(N, T) \

    for ((N) = RB_TREE_MAX(T); (N); \

        (N) = rb_tree_iterate((T), (N), RB_DIR_LEFT))

#ifdef RBDEBUG

TAILQ_HEAD(rb_node_qh, rb_node);

#define        RB_TAILQ_REMOVE(a, b, c)                TAILQ_REMOVE(a, b, c)

#define        RB_TAILQ_INIT(a)                        TAILQ_INIT(a)

#define        RB_TAILQ_INSERT_HEAD(a, b, c)                TAILQ_INSERT_HEAD(a, b, c)

#define        RB_TAILQ_INSERT_BEFORE(a, b, c)                TAILQ_INSERT_BEFORE(a, b, c)

#define        RB_TAILQ_INSERT_AFTER(a, b, c, d)        TAILQ_INSERT_AFTER(a, b, c, d)

#else

#define        RB_TAILQ_REMOVE(a, b, c)                do { } while (/*CONSTCOND*/0)

#define        RB_TAILQ_INIT(a)                        do { } while (/*CONSTCOND*/0)

#define        RB_TAILQ_INSERT_HEAD(a, b, c)                do { } while (/*CONSTCOND*/0)

#define        RB_TAILQ_INSERT_BEFORE(a, b, c)                do { } while (/*CONSTCOND*/0)

#define        RB_TAILQ_INSERT_AFTER(a, b, c, d)        do { } while (/*CONSTCOND*/0)

#endif /* RBDEBUG */

/*

 * rbto_compare_nodes_fn:

 *        return a positive value if the first node > the second node.

 *        return a negative value if the first node < the second node.

 *        return 0 if they are considered same.

 *

 * rbto_compare_key_fn:

 *        return a positive value if the node > the key.

 *        return a negative value if the node < the key.

 *        return 0 if they are considered same.

 */

typedef signed int (*rbto_compare_nodes_fn)(void *, const void *, const void *);

typedef signed int (*rbto_compare_key_fn)(void *, const void *, const void *);

typedef struct {

        rbto_compare_nodes_fn rbto_compare_nodes;

        rbto_compare_key_fn rbto_compare_key;

        size_t rbto_node_offset;

        void *rbto_context;

} rb_tree_ops_t;

typedef struct rb_tree {

        struct rb_node *rbt_root;

        const rb_tree_ops_t *rbt_ops;

        struct rb_node *rbt_minmax[2];

#ifdef RBDEBUG

        struct rb_node_qh rbt_nodes;

#endif

#ifdef RBSTATS

        unsigned int rbt_count;

        unsigned int rbt_insertions;

        unsigned int rbt_removals;

        unsigned int rbt_insertion_rebalance_calls;

        unsigned int rbt_insertion_rebalance_passes;

        unsigned int rbt_removal_rebalance_calls;

        unsigned int rbt_removal_rebalance_passes;

#endif

} rb_tree_t;

#ifdef RBSTATS

#define        RBSTAT_INC(v)        ((void)((v)++))

#define        RBSTAT_DEC(v)        ((void)((v)--))

#else

#define        RBSTAT_INC(v)        do { } while (/*CONSTCOND*/0)

#define        RBSTAT_DEC(v)        do { } while (/*CONSTCOND*/0)

#endif

void        rb_tree_init(rb_tree_t *, const rb_tree_ops_t *);

void *        rb_tree_insert_node(rb_tree_t *, void *);

void *        rb_tree_find_node(rb_tree_t *, const void *);

void *        rb_tree_find_node_geq(rb_tree_t *, const void *);

void *        rb_tree_find_node_leq(rb_tree_t *, const void *);

void        rb_tree_remove_node(rb_tree_t *, void *);

void *        rb_tree_iterate(rb_tree_t *, void *, const unsigned int);

#ifdef RBDEBUG

void        rb_tree_check(const rb_tree_t *, bool);

#endif

#ifdef RBSTATS

void        rb_tree_depths(const rb_tree_t *, size_t *);

#endif

__END_DECLS

#endif        /* _SYS_RBTREE_H_*/