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kc3-lang/libevent/WIN32-Code/tree.h

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  • Author : Azat Khuzhin
    Date : 2014-03-28 20:44:09
    Hash : 61931871
    Message : tree.h: drop duplicated content of tree.h Introduced in 9859bc783adcd51729b3d7563902ac8caca67b42 ("r15764@tombo: nickm | 2007-12-31 15:46:16 -0500")

  • WIN32-Code/tree.h
  • /*	$OpenBSD: tree.h,v 1.7 2002/10/17 21:51:54 art Exp $	*/
    /*
     * 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.
     */
    
    #ifndef	_SYS_TREE_H_
    #define	_SYS_TREE_H_
    
    /*
     * This file defines data structures for different types of trees:
     * splay trees and red-black trees.
     *
     * A splay tree is a self-organizing data structure.  Every operation
     * on the tree causes a splay to happen.  The splay moves the requested
     * node to the root of the tree and partly rebalances it.
     *
     * This has the benefit that request locality causes faster lookups as
     * the requested nodes move to the top of the tree.  On the other hand,
     * every lookup causes memory writes.
     *
     * The Balance Theorem bounds the total access time for m operations
     * and n inserts on an initially empty tree as O((m + n)lg n).  The
     * amortized cost for a sequence of m accesses to a splay tree is O(lg n);
     *
     * A red-black tree is a binary search tree with the node color as an
     * extra attribute.  It fulfills a set of conditions:
     *	- every search path from the root to a leaf consists of the
     *	  same number of black nodes,
     *	- each red node (except for the root) has a black parent,
     *	- each leaf node is black.
     *
     * Every operation on a red-black tree is bounded as O(lg n).
     * The maximum height of a red-black tree is 2lg (n+1).
     */
    
    #define SPLAY_HEAD(name, type)						\
    struct name {								\
    	struct type *sph_root; /* root of the tree */			\
    }
    
    #define SPLAY_INITIALIZER(root)						\
    	{ NULL }
    
    #define SPLAY_INIT(root) do {						\
    	(root)->sph_root = NULL;					\
    } while (0)
    
    #define SPLAY_ENTRY(type)						\
    struct {								\
    	struct type *spe_left; /* left element */			\
    	struct type *spe_right; /* right element */			\
    }
    
    #define SPLAY_LEFT(elm, field)		(elm)->field.spe_left
    #define SPLAY_RIGHT(elm, field)		(elm)->field.spe_right
    #define SPLAY_ROOT(head)		(head)->sph_root
    #define SPLAY_EMPTY(head)		(SPLAY_ROOT(head) == NULL)
    
    /* SPLAY_ROTATE_{LEFT,RIGHT} expect that tmp hold SPLAY_{RIGHT,LEFT} */
    #define SPLAY_ROTATE_RIGHT(head, tmp, field) do {			\
    	SPLAY_LEFT((head)->sph_root, field) = SPLAY_RIGHT(tmp, field);	\
    	SPLAY_RIGHT(tmp, field) = (head)->sph_root;			\
    	(head)->sph_root = tmp;						\
    } while (0)
    
    #define SPLAY_ROTATE_LEFT(head, tmp, field) do {			\
    	SPLAY_RIGHT((head)->sph_root, field) = SPLAY_LEFT(tmp, field);	\
    	SPLAY_LEFT(tmp, field) = (head)->sph_root;			\
    	(head)->sph_root = tmp;						\
    } while (0)
    
    #define SPLAY_LINKLEFT(head, tmp, field) do {				\
    	SPLAY_LEFT(tmp, field) = (head)->sph_root;			\
    	tmp = (head)->sph_root;						\
    	(head)->sph_root = SPLAY_LEFT((head)->sph_root, field);		\
    } while (0)
    
    #define SPLAY_LINKRIGHT(head, tmp, field) do {				\
    	SPLAY_RIGHT(tmp, field) = (head)->sph_root;			\
    	tmp = (head)->sph_root;						\
    	(head)->sph_root = SPLAY_RIGHT((head)->sph_root, field);	\
    } while (0)
    
    #define SPLAY_ASSEMBLE(head, node, left, right, field) do {		\
    	SPLAY_RIGHT(left, field) = SPLAY_LEFT((head)->sph_root, field);	\
    	SPLAY_LEFT(right, field) = SPLAY_RIGHT((head)->sph_root, field);\
    	SPLAY_LEFT((head)->sph_root, field) = SPLAY_RIGHT(node, field);	\
    	SPLAY_RIGHT((head)->sph_root, field) = SPLAY_LEFT(node, field);	\
    } while (0)
    
    /* Generates prototypes and inline functions */
    
    #define SPLAY_PROTOTYPE(name, type, field, cmp)				\
    void name##_SPLAY(struct name *, struct type *);			\
    void name##_SPLAY_MINMAX(struct name *, int);				\
    struct type *name##_SPLAY_INSERT(struct name *, struct type *);		\
    struct type *name##_SPLAY_REMOVE(struct name *, struct type *);		\
    									\
    /* Finds the node with the same key as elm */				\
    static __inline struct type *						\
    name##_SPLAY_FIND(struct name *head, struct type *elm)			\
    {									\
    	if (SPLAY_EMPTY(head))						\
    		return(NULL);						\
    	name##_SPLAY(head, elm);					\
    	if ((cmp)(elm, (head)->sph_root) == 0)				\
    		return (head->sph_root);				\
    	return (NULL);							\
    }									\
    									\
    static __inline struct type *						\
    name##_SPLAY_NEXT(struct name *head, struct type *elm)			\
    {									\
    	name##_SPLAY(head, elm);					\
    	if (SPLAY_RIGHT(elm, field) != NULL) {				\
    		elm = SPLAY_RIGHT(elm, field);				\
    		while (SPLAY_LEFT(elm, field) != NULL) {		\
    			elm = SPLAY_LEFT(elm, field);			\
    		}							\
    	} else								\
    		elm = NULL;						\
    	return (elm);							\
    }									\
    									\
    static __inline struct type *						\
    name##_SPLAY_MIN_MAX(struct name *head, int val)			\
    {									\
    	name##_SPLAY_MINMAX(head, val);					\
    	return (SPLAY_ROOT(head));					\
    }
    
    /* Main splay operation.
     * Moves node close to the key of elm to top
     */
    #define SPLAY_GENERATE(name, type, field, cmp)				\
    struct type *								\
    name##_SPLAY_INSERT(struct name *head, struct type *elm)		\
    {									\
        if (SPLAY_EMPTY(head)) {						\
    	    SPLAY_LEFT(elm, field) = SPLAY_RIGHT(elm, field) = NULL;	\
        } else {								\
    	    int __comp;							\
    	    name##_SPLAY(head, elm);					\
    	    __comp = (cmp)(elm, (head)->sph_root);			\
    	    if(__comp < 0) {						\
    		    SPLAY_LEFT(elm, field) = SPLAY_LEFT((head)->sph_root, field);\
    		    SPLAY_RIGHT(elm, field) = (head)->sph_root;		\
    		    SPLAY_LEFT((head)->sph_root, field) = NULL;		\
    	    } else if (__comp > 0) {					\
    		    SPLAY_RIGHT(elm, field) = SPLAY_RIGHT((head)->sph_root, field);\
    		    SPLAY_LEFT(elm, field) = (head)->sph_root;		\
    		    SPLAY_RIGHT((head)->sph_root, field) = NULL;	\
    	    } else							\
    		    return ((head)->sph_root);				\
        }									\
        (head)->sph_root = (elm);						\
        return (NULL);							\
    }									\
    									\
    struct type *								\
    name##_SPLAY_REMOVE(struct name *head, struct type *elm)		\
    {									\
    	struct type *__tmp;						\
    	if (SPLAY_EMPTY(head))						\
    		return (NULL);						\
    	name##_SPLAY(head, elm);					\
    	if ((cmp)(elm, (head)->sph_root) == 0) {			\
    		if (SPLAY_LEFT((head)->sph_root, field) == NULL) {	\
    			(head)->sph_root = SPLAY_RIGHT((head)->sph_root, field);\
    		} else {						\
    			__tmp = SPLAY_RIGHT((head)->sph_root, field);	\
    			(head)->sph_root = SPLAY_LEFT((head)->sph_root, field);\
    			name##_SPLAY(head, elm);			\
    			SPLAY_RIGHT((head)->sph_root, field) = __tmp;	\
    		}							\
    		return (elm);						\
    	}								\
    	return (NULL);							\
    }									\
    									\
    void									\
    name##_SPLAY(struct name *head, struct type *elm)			\
    {									\
    	struct type __node, *__left, *__right, *__tmp;			\
    	int __comp;							\
    \
    	SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = NULL;\
    	__left = __right = &__node;					\
    \
    	while ((__comp = (cmp)(elm, (head)->sph_root))) {		\
    		if (__comp < 0) {					\
    			__tmp = SPLAY_LEFT((head)->sph_root, field);	\
    			if (__tmp == NULL)				\
    				break;					\
    			if ((cmp)(elm, __tmp) < 0){			\
    				SPLAY_ROTATE_RIGHT(head, __tmp, field);	\
    				if (SPLAY_LEFT((head)->sph_root, field) == NULL)\
    					break;				\
    			}						\
    			SPLAY_LINKLEFT(head, __right, field);		\
    		} else if (__comp > 0) {				\
    			__tmp = SPLAY_RIGHT((head)->sph_root, field);	\
    			if (__tmp == NULL)				\
    				break;					\
    			if ((cmp)(elm, __tmp) > 0){			\
    				SPLAY_ROTATE_LEFT(head, __tmp, field);	\
    				if (SPLAY_RIGHT((head)->sph_root, field) == NULL)\
    					break;				\
    			}						\
    			SPLAY_LINKRIGHT(head, __left, field);		\
    		}							\
    	}								\
    	SPLAY_ASSEMBLE(head, &__node, __left, __right, field);		\
    }									\
    									\
    /* Splay with either the minimum or the maximum element			\
     * Used to find minimum or maximum element in tree.			\
     */									\
    void name##_SPLAY_MINMAX(struct name *head, int __comp) \
    {									\
    	struct type __node, *__left, *__right, *__tmp;			\
    \
    	SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = NULL;\
    	__left = __right = &__node;					\
    \
    	while (1) {							\
    		if (__comp < 0) {					\
    			__tmp = SPLAY_LEFT((head)->sph_root, field);	\
    			if (__tmp == NULL)				\
    				break;					\
    			if (__comp < 0){				\
    				SPLAY_ROTATE_RIGHT(head, __tmp, field);	\
    				if (SPLAY_LEFT((head)->sph_root, field) == NULL)\
    					break;				\
    			}						\
    			SPLAY_LINKLEFT(head, __right, field);		\
    		} else if (__comp > 0) {				\
    			__tmp = SPLAY_RIGHT((head)->sph_root, field);	\
    			if (__tmp == NULL)				\
    				break;					\
    			if (__comp > 0) {				\
    				SPLAY_ROTATE_LEFT(head, __tmp, field);	\
    				if (SPLAY_RIGHT((head)->sph_root, field) == NULL)\
    					break;				\
    			}						\
    			SPLAY_LINKRIGHT(head, __left, field);		\
    		}							\
    	}								\
    	SPLAY_ASSEMBLE(head, &__node, __left, __right, field);		\
    }
    
    #define SPLAY_NEGINF	-1
    #define SPLAY_INF	1
    
    #define SPLAY_INSERT(name, x, y)	name##_SPLAY_INSERT(x, y)
    #define SPLAY_REMOVE(name, x, y)	name##_SPLAY_REMOVE(x, y)
    #define SPLAY_FIND(name, x, y)		name##_SPLAY_FIND(x, y)
    #define SPLAY_NEXT(name, x, y)		name##_SPLAY_NEXT(x, y)
    #define SPLAY_MIN(name, x)		(SPLAY_EMPTY(x) ? NULL	\
    					: name##_SPLAY_MIN_MAX(x, SPLAY_NEGINF))
    #define SPLAY_MAX(name, x)		(SPLAY_EMPTY(x) ? NULL	\
    					: name##_SPLAY_MIN_MAX(x, SPLAY_INF))
    
    #define SPLAY_FOREACH(x, name, head)					\
    	for ((x) = SPLAY_MIN(name, head);				\
    	     (x) != NULL;						\
    	     (x) = SPLAY_NEXT(name, head, x))
    
    /* Macros that define a red-back 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 (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 (0)
    
    #define RB_SET_BLACKRED(black, red, field) do {				\
    	RB_COLOR(black, field) = RB_BLACK;				\
    	RB_COLOR(red, field) = RB_RED;					\
    } while (0)
    
    #ifndef RB_AUGMENT
    #define RB_AUGMENT(x)
    #endif
    
    #define RB_ROTATE_LEFT(head, elm, tmp, field) do {			\
    	(tmp) = RB_RIGHT(elm, field);					\
    	if ((RB_RIGHT(elm, field) = RB_LEFT(tmp, field))) {		\
    		RB_PARENT(RB_LEFT(tmp, field), field) = (elm);		\
    	}								\
    	RB_AUGMENT(elm);						\
    	if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field))) {		\
    		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 (0)
    
    #define RB_ROTATE_RIGHT(head, elm, tmp, field) do {			\
    	(tmp) = RB_LEFT(elm, field);					\
    	if ((RB_LEFT(elm, field) = RB_RIGHT(tmp, field))) {		\
    		RB_PARENT(RB_RIGHT(tmp, field), field) = (elm);		\
    	}								\
    	RB_AUGMENT(elm);						\
    	if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field))) {		\
    		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 (0)
    
    /* Generates prototypes and inline functions */
    #define RB_PROTOTYPE(name, type, field, cmp)				\
    void name##_RB_INSERT_COLOR(struct name *, struct type *);	\
    void name##_RB_REMOVE_COLOR(struct name *, struct type *, struct type *);\
    struct type *name##_RB_REMOVE(struct name *, struct type *);		\
    struct type *name##_RB_INSERT(struct name *, struct type *);		\
    struct type *name##_RB_FIND(struct name *, struct type *);		\
    struct type *name##_RB_NEXT(struct type *);				\
    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)				\
    void									\
    name##_RB_INSERT_COLOR(struct name *head, struct type *elm)		\
    {									\
    	struct type *parent, *gparent, *tmp;				\
    	while ((parent = RB_PARENT(elm, field)) &&			\
    	    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;			\
    }									\
    									\
    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)))\
    						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)))\
    						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;			\
    }									\
    									\
    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)))			\
    			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)));	\
    		}							\
    		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 */					\
    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 */				\
    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);							\
    }									\
    									\
    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);							\
    }									\
    									\
    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_NEXT(name, x, y)	name##_RB_NEXT(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))
    
    #endif	/* _SYS_TREE_H_ */