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/*-
 * Copyright 2002 Niels Provos <provos@citi.umich.edu>
 * All rights reserved.
 *
 * 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 AUTHOR ``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 AUTHOR 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.
 */

/*
 * This source is from sys/tree.h of Free BSD with following modifications
 *  1. remove SPLAY tree part
 *  2. etc. (trivial)
 */

#ifndef _RB_TREE_H_
#define _RB_TREE_H_

/* Macros that define a red-black tree */
#define RB_HEAD(name, type)                     \
struct name {                               \
    struct type *rbh_root; /* root of the tree */           \
}

#define RB_INITIALIZER(root)                        \
    { NULL }

#define RB_INIT(root) do {                      \
    (root)->rbh_root = NULL;                    \
} while (/*CONSTCOND*/ 0)

#define RB_BLACK    0
#define RB_RED      1
#define RB_ENTRY(type)                          \
struct {                                \
    struct type *rbe_left;      /* left element */      \
    struct type *rbe_right;     /* right element */     \
    struct type *rbe_parent;    /* parent element */        \
    int rbe_color;          /* node color */        \
}

#define RB_LEFT(elm, field)     (elm)->field.rbe_left
#define RB_RIGHT(elm, field)        (elm)->field.rbe_right
#define RB_PARENT(elm, field)       (elm)->field.rbe_parent
#define RB_COLOR(elm, field)        (elm)->field.rbe_color
#define RB_ROOT(head)           (head)->rbh_root
#define RB_EMPTY(head)          (RB_ROOT(head) == NULL)

#define RB_SET(elm, parent, field) do {                 \
    RB_PARENT(elm, field) = parent;                 \
    RB_LEFT(elm, field) = RB_RIGHT(elm, field) = NULL;      \
    RB_COLOR(elm, field) = RB_RED;                  \
} while (/*CONSTCOND*/ 0)

#define RB_SET_BLACKRED(black, red, field) do {             \
    RB_COLOR(black, field) = RB_BLACK;              \
    RB_COLOR(red, field) = RB_RED;                  \
} while (/*CONSTCOND*/ 0)

#ifndef RB_AUGMENT
#define RB_AUGMENT(x)   do {} while (0)
#endif

#define RB_ROTATE_LEFT(head, elm, tmp, field) do {          \
    (tmp) = RB_RIGHT(elm, field);                   \
    if ((RB_RIGHT(elm, field) = RB_LEFT(tmp, field)) != NULL) { \
        RB_PARENT(RB_LEFT(tmp, field), field) = (elm);      \
    }                               \
    RB_AUGMENT(elm);                        \
    if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field)) != NULL) {  \
        if ((elm) == RB_LEFT(RB_PARENT(elm, field), field)) \
            RB_LEFT(RB_PARENT(elm, field), field) = (tmp);  \
        else                            \
            RB_RIGHT(RB_PARENT(elm, field), field) = (tmp); \
    } else                              \
        (head)->rbh_root = (tmp);               \
    RB_LEFT(tmp, field) = (elm);                    \
    RB_PARENT(elm, field) = (tmp);                  \
    RB_AUGMENT(tmp);                        \
    if ((RB_PARENT(tmp, field)))                    \
        RB_AUGMENT(RB_PARENT(tmp, field));          \
} while (/*CONSTCOND*/ 0)

#define RB_ROTATE_RIGHT(head, elm, tmp, field) do {         \
    (tmp) = RB_LEFT(elm, field);                    \
    if ((RB_LEFT(elm, field) = RB_RIGHT(tmp, field)) != NULL) { \
        RB_PARENT(RB_RIGHT(tmp, field), field) = (elm);     \
    }                               \
    RB_AUGMENT(elm);                        \
    if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field)) != NULL) {  \
        if ((elm) == RB_LEFT(RB_PARENT(elm, field), field)) \
            RB_LEFT(RB_PARENT(elm, field), field) = (tmp);  \
        else                            \
            RB_RIGHT(RB_PARENT(elm, field), field) = (tmp); \
    } else                              \
        (head)->rbh_root = (tmp);               \
    RB_RIGHT(tmp, field) = (elm);                   \
    RB_PARENT(elm, field) = (tmp);                  \
    RB_AUGMENT(tmp);                        \
    if ((RB_PARENT(tmp, field)))                    \
        RB_AUGMENT(RB_PARENT(tmp, field));          \
} while (/*CONSTCOND*/ 0)

/* Generates prototypes and inline functions */
#define RB_PROTOTYPE(name, type, field, cmp)                \
    RB_PROTOTYPE_INTERNAL(name, type, field, cmp,)
#define RB_PROTOTYPE_STATIC(name, type, field, cmp)         \
    RB_PROTOTYPE_INTERNAL(name, type, field, cmp, static)
#define RB_PROTOTYPE_INTERNAL(name, type, field, cmp, attr)     \
attr void name##_RB_INSERT_COLOR(struct name *, struct type *);     \
attr void name##_RB_REMOVE_COLOR(struct name *, struct type *, struct type *);\
attr struct type *name##_RB_REMOVE(struct name *, struct type *);   \
attr struct type *name##_RB_INSERT(struct name *, struct type *);   \
attr struct type *name##_RB_FIND(struct name *, struct type *);     \
attr struct type *name##_RB_NFIND(struct name *, struct type *);    \
attr struct type *name##_RB_NEXT(struct type *);            \
attr struct type *name##_RB_PREV(struct type *);            \
attr struct type *name##_RB_MINMAX(struct name *, int);         \
                                    \

/* Main rb operation.
 * Moves node close to the key of elm to top
 */
#define RB_GENERATE(name, type, field, cmp)             \
    RB_GENERATE_INTERNAL(name, type, field, cmp,)
#define RB_GENERATE_STATIC(name, type, field, cmp)          \
    RB_GENERATE_INTERNAL(name, type, field, cmp, static)
#define RB_GENERATE_INTERNAL(name, type, field, cmp, attr)      \
attr void                               \
name##_RB_INSERT_COLOR(struct name *head, struct type *elm)     \
{                                   \
    struct type *parent, *gparent, *tmp;                \
    while ((parent = RB_PARENT(elm, field)) != NULL &&      \
        RB_COLOR(parent, field) == RB_RED) {            \
        gparent = RB_PARENT(parent, field);         \
        if (parent == RB_LEFT(gparent, field)) {        \
            tmp = RB_RIGHT(gparent, field);         \
            if (tmp && RB_COLOR(tmp, field) == RB_RED) {    \
                RB_COLOR(tmp, field) = RB_BLACK;    \
                RB_SET_BLACKRED(parent, gparent, field);\
                elm = gparent;              \
                continue;               \
            }                       \
            if (RB_RIGHT(parent, field) == elm) {       \
                RB_ROTATE_LEFT(head, parent, tmp, field);\
                tmp = parent;               \
                parent = elm;               \
                elm = tmp;              \
            }                       \
            RB_SET_BLACKRED(parent, gparent, field);    \
            RB_ROTATE_RIGHT(head, gparent, tmp, field); \
        } else {                        \
            tmp = RB_LEFT(gparent, field);          \
            if (tmp && RB_COLOR(tmp, field) == RB_RED) {    \
                RB_COLOR(tmp, field) = RB_BLACK;    \
                RB_SET_BLACKRED(parent, gparent, field);\
                elm = gparent;              \
                continue;               \
            }                       \
            if (RB_LEFT(parent, field) == elm) {        \
                RB_ROTATE_RIGHT(head, parent, tmp, field);\
                tmp = parent;               \
                parent = elm;               \
                elm = tmp;              \
            }                       \
            RB_SET_BLACKRED(parent, gparent, field);    \
            RB_ROTATE_LEFT(head, gparent, tmp, field);  \
        }                           \
    }                               \
    RB_COLOR(head->rbh_root, field) = RB_BLACK;         \
}                                   \
                                    \
attr void                               \
name##_RB_REMOVE_COLOR(struct name *head, struct type *parent, struct type *elm) \
{                                   \
    struct type *tmp;                       \
    while ((elm == NULL || RB_COLOR(elm, field) == RB_BLACK) && \
        elm != RB_ROOT(head)) {                 \
        if (RB_LEFT(parent, field) == elm) {            \
            tmp = RB_RIGHT(parent, field);          \
            if (RB_COLOR(tmp, field) == RB_RED) {       \
                RB_SET_BLACKRED(tmp, parent, field);    \
                RB_ROTATE_LEFT(head, parent, tmp, field);\
                tmp = RB_RIGHT(parent, field);      \
            }                       \
            if ((RB_LEFT(tmp, field) == NULL ||     \
                RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
                (RB_RIGHT(tmp, field) == NULL ||        \
                RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
                RB_COLOR(tmp, field) = RB_RED;      \
                elm = parent;               \
                parent = RB_PARENT(elm, field);     \
            } else {                    \
                if (RB_RIGHT(tmp, field) == NULL || \
                    RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK) {\
                    struct type *oleft;     \
                    if ((oleft = RB_LEFT(tmp, field)) \
                        != NULL)            \
                        RB_COLOR(oleft, field) = RB_BLACK;\
                    RB_COLOR(tmp, field) = RB_RED;  \
                    RB_ROTATE_RIGHT(head, tmp, oleft, field);\
                    tmp = RB_RIGHT(parent, field);  \
                }                   \
                RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
                RB_COLOR(parent, field) = RB_BLACK; \
                if (RB_RIGHT(tmp, field))       \
                    RB_COLOR(RB_RIGHT(tmp, field), field) = RB_BLACK;\
                RB_ROTATE_LEFT(head, parent, tmp, field);\
                elm = RB_ROOT(head);            \
                break;                  \
            }                       \
        } else {                        \
            tmp = RB_LEFT(parent, field);           \
            if (RB_COLOR(tmp, field) == RB_RED) {       \
                RB_SET_BLACKRED(tmp, parent, field);    \
                RB_ROTATE_RIGHT(head, parent, tmp, field);\
                tmp = RB_LEFT(parent, field);       \
            }                       \
            if ((RB_LEFT(tmp, field) == NULL ||     \
                RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
                (RB_RIGHT(tmp, field) == NULL ||        \
                RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
                RB_COLOR(tmp, field) = RB_RED;      \
                elm = parent;               \
                parent = RB_PARENT(elm, field);     \
            } else {                    \
                if (RB_LEFT(tmp, field) == NULL ||  \
                    RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) {\
                    struct type *oright;        \
                    if ((oright = RB_RIGHT(tmp, field)) \
                        != NULL)            \
                        RB_COLOR(oright, field) = RB_BLACK;\
                    RB_COLOR(tmp, field) = RB_RED;  \
                    RB_ROTATE_LEFT(head, tmp, oright, field);\
                    tmp = RB_LEFT(parent, field);   \
                }                   \
                RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
                RB_COLOR(parent, field) = RB_BLACK; \
                if (RB_LEFT(tmp, field))        \
                    RB_COLOR(RB_LEFT(tmp, field), field) = RB_BLACK;\
                RB_ROTATE_RIGHT(head, parent, tmp, field);\
                elm = RB_ROOT(head);            \
                break;                  \
            }                       \
        }                           \
    }                               \
    if (elm)                            \
        RB_COLOR(elm, field) = RB_BLACK;            \
}                                   \
                                    \
attr struct type *                          \
name##_RB_REMOVE(struct name *head, struct type *elm)           \
{                                   \
    struct type *child, *parent, *old = elm;            \
    int color;                          \
    if (RB_LEFT(elm, field) == NULL)                \
        child = RB_RIGHT(elm, field);               \
    else if (RB_RIGHT(elm, field) == NULL)              \
        child = RB_LEFT(elm, field);                \
    else {                              \
        struct type *left;                  \
        elm = RB_RIGHT(elm, field);             \
        while ((left = RB_LEFT(elm, field)) != NULL)        \
            elm = left;                 \
        child = RB_RIGHT(elm, field);               \
        parent = RB_PARENT(elm, field);             \
        color = RB_COLOR(elm, field);               \
        if (child)                      \
            RB_PARENT(child, field) = parent;       \
        if (parent) {                       \
            if (RB_LEFT(parent, field) == elm)      \
                RB_LEFT(parent, field) = child;     \
            else                        \
                RB_RIGHT(parent, field) = child;    \
            RB_AUGMENT(parent);             \
        } else                          \
            RB_ROOT(head) = child;              \
        if (RB_PARENT(elm, field) == old)           \
            parent = elm;                   \
        (elm)->field = (old)->field;                \
        if (RB_PARENT(old, field)) {                \
            if (RB_LEFT(RB_PARENT(old, field), field) == old)\
                RB_LEFT(RB_PARENT(old, field), field) = elm;\
            else                        \
                RB_RIGHT(RB_PARENT(old, field), field) = elm;\
            RB_AUGMENT(RB_PARENT(old, field));      \
        } else                          \
            RB_ROOT(head) = elm;                \
        RB_PARENT(RB_LEFT(old, field), field) = elm;        \
        if (RB_RIGHT(old, field))               \
            RB_PARENT(RB_RIGHT(old, field), field) = elm;   \
        if (parent) {                       \
            left = parent;                  \
            do {                        \
                RB_AUGMENT(left);           \
            } while ((left = RB_PARENT(left, field)) != NULL); \
        }                           \
        goto color;                     \
    }                               \
    parent = RB_PARENT(elm, field);                 \
    color = RB_COLOR(elm, field);                   \
    if (child)                          \
        RB_PARENT(child, field) = parent;           \
    if (parent) {                           \
        if (RB_LEFT(parent, field) == elm)          \
            RB_LEFT(parent, field) = child;         \
        else                            \
            RB_RIGHT(parent, field) = child;        \
        RB_AUGMENT(parent);                 \
    } else                              \
        RB_ROOT(head) = child;                  \
color:                                  \
    if (color == RB_BLACK)                      \
        name##_RB_REMOVE_COLOR(head, parent, child);        \
    return (old);                           \
}                                   \
                                    \
/* Inserts a node into the RB tree */                   \
attr struct type *                          \
name##_RB_INSERT(struct name *head, struct type *elm)           \
{                                   \
    struct type *tmp;                       \
    struct type *parent = NULL;                 \
    int comp = 0;                           \
    tmp = RB_ROOT(head);                        \
    while (tmp) {                           \
        parent = tmp;                       \
        comp = (cmp)(elm, parent);              \
        if (comp < 0)                       \
            tmp = RB_LEFT(tmp, field);          \
        else if (comp > 0)                  \
            tmp = RB_RIGHT(tmp, field);         \
        else                            \
            return (tmp);                   \
    }                               \
    RB_SET(elm, parent, field);                 \
    if (parent != NULL) {                       \
        if (comp < 0)                       \
            RB_LEFT(parent, field) = elm;           \
        else                            \
            RB_RIGHT(parent, field) = elm;          \
        RB_AUGMENT(parent);                 \
    } else                              \
        RB_ROOT(head) = elm;                    \
    name##_RB_INSERT_COLOR(head, elm);              \
    return (NULL);                          \
}                                   \
                                    \
/* Finds the node with the same key as elm */               \
attr struct type *                          \
name##_RB_FIND(struct name *head, struct type *elm)         \
{                                   \
    struct type *tmp = RB_ROOT(head);               \
    int comp;                           \
    while (tmp) {                           \
        comp = cmp(elm, tmp);                   \
        if (comp < 0)                       \
            tmp = RB_LEFT(tmp, field);          \
        else if (comp > 0)                  \
            tmp = RB_RIGHT(tmp, field);         \
        else                            \
            return (tmp);                   \
    }                               \
    return (NULL);                          \
}                                   \
                                    \
/* Finds the first node greater than or equal to the search key */  \
attr struct type *                          \
name##_RB_NFIND(struct name *head, struct type *elm)            \
{                                   \
    struct type *tmp = RB_ROOT(head);               \
    struct type *res = NULL;                    \
    int comp;                           \
    while (tmp) {                           \
        comp = cmp(elm, tmp);                   \
        if (comp < 0) {                     \
            res = tmp;                  \
            tmp = RB_LEFT(tmp, field);          \
        }                           \
        else if (comp > 0)                  \
            tmp = RB_RIGHT(tmp, field);         \
        else                            \
            return (tmp);                   \
    }                               \
    return (res);                           \
}                                   \
                                    \
/* ARGSUSED */                              \
attr struct type *                          \
name##_RB_NEXT(struct type *elm)                    \
{                                   \
    if (RB_RIGHT(elm, field)) {                 \
        elm = RB_RIGHT(elm, field);             \
        while (RB_LEFT(elm, field))             \
            elm = RB_LEFT(elm, field);          \
    } else {                            \
        if (RB_PARENT(elm, field) &&                \
            (elm == RB_LEFT(RB_PARENT(elm, field), field))) \
            elm = RB_PARENT(elm, field);            \
        else {                          \
            while (RB_PARENT(elm, field) &&         \
                (elm == RB_RIGHT(RB_PARENT(elm, field), field)))\
                elm = RB_PARENT(elm, field);        \
            elm = RB_PARENT(elm, field);            \
        }                           \
    }                               \
    return (elm);                           \
}                                   \
                                    \
/* ARGSUSED */                              \
attr struct type *                          \
name##_RB_PREV(struct type *elm)                    \
{                                   \
    if (RB_LEFT(elm, field)) {                  \
        elm = RB_LEFT(elm, field);              \
        while (RB_RIGHT(elm, field))                \
            elm = RB_RIGHT(elm, field);         \
    } else {                            \
        if (RB_PARENT(elm, field) &&                \
            (elm == RB_RIGHT(RB_PARENT(elm, field), field)))    \
            elm = RB_PARENT(elm, field);            \
        else {                          \
            while (RB_PARENT(elm, field) &&         \
                (elm == RB_LEFT(RB_PARENT(elm, field), field)))\
                elm = RB_PARENT(elm, field);        \
            elm = RB_PARENT(elm, field);            \
        }                           \
    }                               \
    return (elm);                           \
}                                   \
                                    \
attr struct type *                          \
name##_RB_MINMAX(struct name *head, int val)                \
{                                   \
    struct type *tmp = RB_ROOT(head);               \
    struct type *parent = NULL;                 \
    while (tmp) {                           \
        parent = tmp;                       \
        if (val < 0)                        \
            tmp = RB_LEFT(tmp, field);          \
        else                            \
            tmp = RB_RIGHT(tmp, field);         \
    }                               \
    return (parent);                        \
}

#define RB_NEGINF   -1
#define RB_INF  1

#define RB_INSERT(name, x, y)   name##_RB_INSERT(x, y)
#define RB_REMOVE(name, x, y)   name##_RB_REMOVE(x, y)
#define RB_FIND(name, x, y) name##_RB_FIND(x, y)
#define RB_NFIND(name, x, y)    name##_RB_NFIND(x, y)
#define RB_NEXT(name, x, y) name##_RB_NEXT(y)
#define RB_PREV(name, x, y) name##_RB_PREV(y)
#define RB_MIN(name, x)     name##_RB_MINMAX(x, RB_NEGINF)
#define RB_MAX(name, x)     name##_RB_MINMAX(x, RB_INF)

#define RB_FOREACH(x, name, head)                   \
    for ((x) = RB_MIN(name, head);                  \
         (x) != NULL;                       \
         (x) = name##_RB_NEXT(x))

#define RB_FOREACH_FROM(x, name, y)                 \
    for ((x) = (y);                         \
        ((x) != NULL) && ((y) = name##_RB_NEXT(x), (x) != NULL);    \
         (x) = (y))

#define RB_FOREACH_SAFE(x, name, head, y)               \
    for ((x) = RB_MIN(name, head);                  \
        ((x) != NULL) && ((y) = name##_RB_NEXT(x), (x) != NULL);    \
         (x) = (y))

#define RB_FOREACH_REVERSE(x, name, head)               \
    for ((x) = RB_MAX(name, head);                  \
         (x) != NULL;                       \
         (x) = name##_RB_PREV(x))

#define RB_FOREACH_REVERSE_FROM(x, name, y)             \
    for ((x) = (y);                         \
        ((x) != NULL) && ((y) = name##_RB_PREV(x), (x) != NULL);    \
         (x) = (y))

#define RB_FOREACH_REVERSE_SAFE(x, name, head, y)           \
    for ((x) = RB_MAX(name, head);                  \
        ((x) != NULL) && ((y) = name##_RB_PREV(x), (x) != NULL);    \
         (x) = (y))

#endif /* _RB_TREE_H_ */