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      1 /*	$OpenBSD: tree.h,v 1.10 2007/10/29 23:49:41 djm Exp $	*/
      2 /*
      3  * Copyright 2002 Niels Provos <provos (at) citi.umich.edu>
      4  * All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  *
     15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     25  */
     26 
     27 /* OPENBSD ORIGINAL: sys/sys/tree.h */
     28 
     29 #ifndef	_SYS_TREE_H_
     30 #define	_SYS_TREE_H_
     31 
     32 /*
     33  * This file defines data structures for different types of trees:
     34  * splay trees and red-black trees.
     35  *
     36  * A splay tree is a self-organizing data structure.  Every operation
     37  * on the tree causes a splay to happen.  The splay moves the requested
     38  * node to the root of the tree and partly rebalances it.
     39  *
     40  * This has the benefit that request locality causes faster lookups as
     41  * the requested nodes move to the top of the tree.  On the other hand,
     42  * every lookup causes memory writes.
     43  *
     44  * The Balance Theorem bounds the total access time for m operations
     45  * and n inserts on an initially empty tree as O((m + n)lg n).  The
     46  * amortized cost for a sequence of m accesses to a splay tree is O(lg n);
     47  *
     48  * A red-black tree is a binary search tree with the node color as an
     49  * extra attribute.  It fulfills a set of conditions:
     50  *	- every search path from the root to a leaf consists of the
     51  *	  same number of black nodes,
     52  *	- each red node (except for the root) has a black parent,
     53  *	- each leaf node is black.
     54  *
     55  * Every operation on a red-black tree is bounded as O(lg n).
     56  * The maximum height of a red-black tree is 2lg (n+1).
     57  */
     58 
     59 #define SPLAY_HEAD(name, type)						\
     60 struct name {								\
     61 	struct type *sph_root; /* root of the tree */			\
     62 }
     63 
     64 #define SPLAY_INITIALIZER(root)						\
     65 	{ NULL }
     66 
     67 #define SPLAY_INIT(root) do {						\
     68 	(root)->sph_root = NULL;					\
     69 } while (0)
     70 
     71 #define SPLAY_ENTRY(type)						\
     72 struct {								\
     73 	struct type *spe_left; /* left element */			\
     74 	struct type *spe_right; /* right element */			\
     75 }
     76 
     77 #define SPLAY_LEFT(elm, field)		(elm)->field.spe_left
     78 #define SPLAY_RIGHT(elm, field)		(elm)->field.spe_right
     79 #define SPLAY_ROOT(head)		(head)->sph_root
     80 #define SPLAY_EMPTY(head)		(SPLAY_ROOT(head) == NULL)
     81 
     82 /* SPLAY_ROTATE_{LEFT,RIGHT} expect that tmp hold SPLAY_{RIGHT,LEFT} */
     83 #define SPLAY_ROTATE_RIGHT(head, tmp, field) do {			\
     84 	SPLAY_LEFT((head)->sph_root, field) = SPLAY_RIGHT(tmp, field);	\
     85 	SPLAY_RIGHT(tmp, field) = (head)->sph_root;			\
     86 	(head)->sph_root = tmp;						\
     87 } while (0)
     88 
     89 #define SPLAY_ROTATE_LEFT(head, tmp, field) do {			\
     90 	SPLAY_RIGHT((head)->sph_root, field) = SPLAY_LEFT(tmp, field);	\
     91 	SPLAY_LEFT(tmp, field) = (head)->sph_root;			\
     92 	(head)->sph_root = tmp;						\
     93 } while (0)
     94 
     95 #define SPLAY_LINKLEFT(head, tmp, field) do {				\
     96 	SPLAY_LEFT(tmp, field) = (head)->sph_root;			\
     97 	tmp = (head)->sph_root;						\
     98 	(head)->sph_root = SPLAY_LEFT((head)->sph_root, field);		\
     99 } while (0)
    100 
    101 #define SPLAY_LINKRIGHT(head, tmp, field) do {				\
    102 	SPLAY_RIGHT(tmp, field) = (head)->sph_root;			\
    103 	tmp = (head)->sph_root;						\
    104 	(head)->sph_root = SPLAY_RIGHT((head)->sph_root, field);	\
    105 } while (0)
    106 
    107 #define SPLAY_ASSEMBLE(head, node, left, right, field) do {		\
    108 	SPLAY_RIGHT(left, field) = SPLAY_LEFT((head)->sph_root, field);	\
    109 	SPLAY_LEFT(right, field) = SPLAY_RIGHT((head)->sph_root, field);\
    110 	SPLAY_LEFT((head)->sph_root, field) = SPLAY_RIGHT(node, field);	\
    111 	SPLAY_RIGHT((head)->sph_root, field) = SPLAY_LEFT(node, field);	\
    112 } while (0)
    113 
    114 /* Generates prototypes and inline functions */
    115 
    116 #define SPLAY_PROTOTYPE(name, type, field, cmp)				\
    117 void name##_SPLAY(struct name *, struct type *);			\
    118 void name##_SPLAY_MINMAX(struct name *, int);				\
    119 struct type *name##_SPLAY_INSERT(struct name *, struct type *);		\
    120 struct type *name##_SPLAY_REMOVE(struct name *, struct type *);		\
    121 									\
    122 /* Finds the node with the same key as elm */				\
    123 static __inline struct type *						\
    124 name##_SPLAY_FIND(struct name *head, struct type *elm)			\
    125 {									\
    126 	if (SPLAY_EMPTY(head))						\
    127 		return(NULL);						\
    128 	name##_SPLAY(head, elm);					\
    129 	if ((cmp)(elm, (head)->sph_root) == 0)				\
    130 		return (head->sph_root);				\
    131 	return (NULL);							\
    132 }									\
    133 									\
    134 static __inline struct type *						\
    135 name##_SPLAY_NEXT(struct name *head, struct type *elm)			\
    136 {									\
    137 	name##_SPLAY(head, elm);					\
    138 	if (SPLAY_RIGHT(elm, field) != NULL) {				\
    139 		elm = SPLAY_RIGHT(elm, field);				\
    140 		while (SPLAY_LEFT(elm, field) != NULL) {		\
    141 			elm = SPLAY_LEFT(elm, field);			\
    142 		}							\
    143 	} else								\
    144 		elm = NULL;						\
    145 	return (elm);							\
    146 }									\
    147 									\
    148 static __inline struct type *						\
    149 name##_SPLAY_MIN_MAX(struct name *head, int val)			\
    150 {									\
    151 	name##_SPLAY_MINMAX(head, val);					\
    152         return (SPLAY_ROOT(head));					\
    153 }
    154 
    155 /* Main splay operation.
    156  * Moves node close to the key of elm to top
    157  */
    158 #define SPLAY_GENERATE(name, type, field, cmp)				\
    159 struct type *								\
    160 name##_SPLAY_INSERT(struct name *head, struct type *elm)		\
    161 {									\
    162     if (SPLAY_EMPTY(head)) {						\
    163 	    SPLAY_LEFT(elm, field) = SPLAY_RIGHT(elm, field) = NULL;	\
    164     } else {								\
    165 	    int __comp;							\
    166 	    name##_SPLAY(head, elm);					\
    167 	    __comp = (cmp)(elm, (head)->sph_root);			\
    168 	    if(__comp < 0) {						\
    169 		    SPLAY_LEFT(elm, field) = SPLAY_LEFT((head)->sph_root, field);\
    170 		    SPLAY_RIGHT(elm, field) = (head)->sph_root;		\
    171 		    SPLAY_LEFT((head)->sph_root, field) = NULL;		\
    172 	    } else if (__comp > 0) {					\
    173 		    SPLAY_RIGHT(elm, field) = SPLAY_RIGHT((head)->sph_root, field);\
    174 		    SPLAY_LEFT(elm, field) = (head)->sph_root;		\
    175 		    SPLAY_RIGHT((head)->sph_root, field) = NULL;	\
    176 	    } else							\
    177 		    return ((head)->sph_root);				\
    178     }									\
    179     (head)->sph_root = (elm);						\
    180     return (NULL);							\
    181 }									\
    182 									\
    183 struct type *								\
    184 name##_SPLAY_REMOVE(struct name *head, struct type *elm)		\
    185 {									\
    186 	struct type *__tmp;						\
    187 	if (SPLAY_EMPTY(head))						\
    188 		return (NULL);						\
    189 	name##_SPLAY(head, elm);					\
    190 	if ((cmp)(elm, (head)->sph_root) == 0) {			\
    191 		if (SPLAY_LEFT((head)->sph_root, field) == NULL) {	\
    192 			(head)->sph_root = SPLAY_RIGHT((head)->sph_root, field);\
    193 		} else {						\
    194 			__tmp = SPLAY_RIGHT((head)->sph_root, field);	\
    195 			(head)->sph_root = SPLAY_LEFT((head)->sph_root, field);\
    196 			name##_SPLAY(head, elm);			\
    197 			SPLAY_RIGHT((head)->sph_root, field) = __tmp;	\
    198 		}							\
    199 		return (elm);						\
    200 	}								\
    201 	return (NULL);							\
    202 }									\
    203 									\
    204 void									\
    205 name##_SPLAY(struct name *head, struct type *elm)			\
    206 {									\
    207 	struct type __node, *__left, *__right, *__tmp;			\
    208 	int __comp;							\
    209 \
    210 	SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = NULL;\
    211 	__left = __right = &__node;					\
    212 \
    213 	while ((__comp = (cmp)(elm, (head)->sph_root))) {		\
    214 		if (__comp < 0) {					\
    215 			__tmp = SPLAY_LEFT((head)->sph_root, field);	\
    216 			if (__tmp == NULL)				\
    217 				break;					\
    218 			if ((cmp)(elm, __tmp) < 0){			\
    219 				SPLAY_ROTATE_RIGHT(head, __tmp, field);	\
    220 				if (SPLAY_LEFT((head)->sph_root, field) == NULL)\
    221 					break;				\
    222 			}						\
    223 			SPLAY_LINKLEFT(head, __right, field);		\
    224 		} else if (__comp > 0) {				\
    225 			__tmp = SPLAY_RIGHT((head)->sph_root, field);	\
    226 			if (__tmp == NULL)				\
    227 				break;					\
    228 			if ((cmp)(elm, __tmp) > 0){			\
    229 				SPLAY_ROTATE_LEFT(head, __tmp, field);	\
    230 				if (SPLAY_RIGHT((head)->sph_root, field) == NULL)\
    231 					break;				\
    232 			}						\
    233 			SPLAY_LINKRIGHT(head, __left, field);		\
    234 		}							\
    235 	}								\
    236 	SPLAY_ASSEMBLE(head, &__node, __left, __right, field);		\
    237 }									\
    238 									\
    239 /* Splay with either the minimum or the maximum element			\
    240  * Used to find minimum or maximum element in tree.			\
    241  */									\
    242 void name##_SPLAY_MINMAX(struct name *head, int __comp) \
    243 {									\
    244 	struct type __node, *__left, *__right, *__tmp;			\
    245 \
    246 	SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = NULL;\
    247 	__left = __right = &__node;					\
    248 \
    249 	while (1) {							\
    250 		if (__comp < 0) {					\
    251 			__tmp = SPLAY_LEFT((head)->sph_root, field);	\
    252 			if (__tmp == NULL)				\
    253 				break;					\
    254 			if (__comp < 0){				\
    255 				SPLAY_ROTATE_RIGHT(head, __tmp, field);	\
    256 				if (SPLAY_LEFT((head)->sph_root, field) == NULL)\
    257 					break;				\
    258 			}						\
    259 			SPLAY_LINKLEFT(head, __right, field);		\
    260 		} else if (__comp > 0) {				\
    261 			__tmp = SPLAY_RIGHT((head)->sph_root, field);	\
    262 			if (__tmp == NULL)				\
    263 				break;					\
    264 			if (__comp > 0) {				\
    265 				SPLAY_ROTATE_LEFT(head, __tmp, field);	\
    266 				if (SPLAY_RIGHT((head)->sph_root, field) == NULL)\
    267 					break;				\
    268 			}						\
    269 			SPLAY_LINKRIGHT(head, __left, field);		\
    270 		}							\
    271 	}								\
    272 	SPLAY_ASSEMBLE(head, &__node, __left, __right, field);		\
    273 }
    274 
    275 #define SPLAY_NEGINF	-1
    276 #define SPLAY_INF	1
    277 
    278 #define SPLAY_INSERT(name, x, y)	name##_SPLAY_INSERT(x, y)
    279 #define SPLAY_REMOVE(name, x, y)	name##_SPLAY_REMOVE(x, y)
    280 #define SPLAY_FIND(name, x, y)		name##_SPLAY_FIND(x, y)
    281 #define SPLAY_NEXT(name, x, y)		name##_SPLAY_NEXT(x, y)
    282 #define SPLAY_MIN(name, x)		(SPLAY_EMPTY(x) ? NULL	\
    283 					: name##_SPLAY_MIN_MAX(x, SPLAY_NEGINF))
    284 #define SPLAY_MAX(name, x)		(SPLAY_EMPTY(x) ? NULL	\
    285 					: name##_SPLAY_MIN_MAX(x, SPLAY_INF))
    286 
    287 #define SPLAY_FOREACH(x, name, head)					\
    288 	for ((x) = SPLAY_MIN(name, head);				\
    289 	     (x) != NULL;						\
    290 	     (x) = SPLAY_NEXT(name, head, x))
    291 
    292 /* Macros that define a red-black tree */
    293 #define RB_HEAD(name, type)						\
    294 struct name {								\
    295 	struct type *rbh_root; /* root of the tree */			\
    296 }
    297 
    298 #define RB_INITIALIZER(root)						\
    299 	{ NULL }
    300 
    301 #define RB_INIT(root) do {						\
    302 	(root)->rbh_root = NULL;					\
    303 } while (0)
    304 
    305 #define RB_BLACK	0
    306 #define RB_RED		1
    307 #define RB_ENTRY(type)							\
    308 struct {								\
    309 	struct type *rbe_left;		/* left element */		\
    310 	struct type *rbe_right;		/* right element */		\
    311 	struct type *rbe_parent;	/* parent element */		\
    312 	int rbe_color;			/* node color */		\
    313 }
    314 
    315 #define RB_LEFT(elm, field)		(elm)->field.rbe_left
    316 #define RB_RIGHT(elm, field)		(elm)->field.rbe_right
    317 #define RB_PARENT(elm, field)		(elm)->field.rbe_parent
    318 #define RB_COLOR(elm, field)		(elm)->field.rbe_color
    319 #define RB_ROOT(head)			(head)->rbh_root
    320 #define RB_EMPTY(head)			(RB_ROOT(head) == NULL)
    321 
    322 #define RB_SET(elm, parent, field) do {					\
    323 	RB_PARENT(elm, field) = parent;					\
    324 	RB_LEFT(elm, field) = RB_RIGHT(elm, field) = NULL;		\
    325 	RB_COLOR(elm, field) = RB_RED;					\
    326 } while (0)
    327 
    328 #define RB_SET_BLACKRED(black, red, field) do {				\
    329 	RB_COLOR(black, field) = RB_BLACK;				\
    330 	RB_COLOR(red, field) = RB_RED;					\
    331 } while (0)
    332 
    333 #ifndef RB_AUGMENT
    334 #define RB_AUGMENT(x)
    335 #endif
    336 
    337 #define RB_ROTATE_LEFT(head, elm, tmp, field) do {			\
    338 	(tmp) = RB_RIGHT(elm, field);					\
    339 	if ((RB_RIGHT(elm, field) = RB_LEFT(tmp, field))) {		\
    340 		RB_PARENT(RB_LEFT(tmp, field), field) = (elm);		\
    341 	}								\
    342 	RB_AUGMENT(elm);						\
    343 	if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field))) {		\
    344 		if ((elm) == RB_LEFT(RB_PARENT(elm, field), field))	\
    345 			RB_LEFT(RB_PARENT(elm, field), field) = (tmp);	\
    346 		else							\
    347 			RB_RIGHT(RB_PARENT(elm, field), field) = (tmp);	\
    348 	} else								\
    349 		(head)->rbh_root = (tmp);				\
    350 	RB_LEFT(tmp, field) = (elm);					\
    351 	RB_PARENT(elm, field) = (tmp);					\
    352 	RB_AUGMENT(tmp);						\
    353 	if ((RB_PARENT(tmp, field)))					\
    354 		RB_AUGMENT(RB_PARENT(tmp, field));			\
    355 } while (0)
    356 
    357 #define RB_ROTATE_RIGHT(head, elm, tmp, field) do {			\
    358 	(tmp) = RB_LEFT(elm, field);					\
    359 	if ((RB_LEFT(elm, field) = RB_RIGHT(tmp, field))) {		\
    360 		RB_PARENT(RB_RIGHT(tmp, field), field) = (elm);		\
    361 	}								\
    362 	RB_AUGMENT(elm);						\
    363 	if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field))) {		\
    364 		if ((elm) == RB_LEFT(RB_PARENT(elm, field), field))	\
    365 			RB_LEFT(RB_PARENT(elm, field), field) = (tmp);	\
    366 		else							\
    367 			RB_RIGHT(RB_PARENT(elm, field), field) = (tmp);	\
    368 	} else								\
    369 		(head)->rbh_root = (tmp);				\
    370 	RB_RIGHT(tmp, field) = (elm);					\
    371 	RB_PARENT(elm, field) = (tmp);					\
    372 	RB_AUGMENT(tmp);						\
    373 	if ((RB_PARENT(tmp, field)))					\
    374 		RB_AUGMENT(RB_PARENT(tmp, field));			\
    375 } while (0)
    376 
    377 /* Generates prototypes and inline functions */
    378 #define RB_PROTOTYPE(name, type, field, cmp)				\
    379 void name##_RB_INSERT_COLOR(struct name *, struct type *);	\
    380 void name##_RB_REMOVE_COLOR(struct name *, struct type *, struct type *);\
    381 struct type *name##_RB_REMOVE(struct name *, struct type *);		\
    382 struct type *name##_RB_INSERT(struct name *, struct type *);		\
    383 struct type *name##_RB_FIND(struct name *, struct type *);		\
    384 struct type *name##_RB_NEXT(struct type *);				\
    385 struct type *name##_RB_MINMAX(struct name *, int);
    386 
    387 
    388 /* Main rb operation.
    389  * Moves node close to the key of elm to top
    390  */
    391 #define RB_GENERATE(name, type, field, cmp)				\
    392 void									\
    393 name##_RB_INSERT_COLOR(struct name *head, struct type *elm)		\
    394 {									\
    395 	struct type *parent, *gparent, *tmp;				\
    396 	while ((parent = RB_PARENT(elm, field)) &&			\
    397 	    RB_COLOR(parent, field) == RB_RED) {			\
    398 		gparent = RB_PARENT(parent, field);			\
    399 		if (parent == RB_LEFT(gparent, field)) {		\
    400 			tmp = RB_RIGHT(gparent, field);			\
    401 			if (tmp && RB_COLOR(tmp, field) == RB_RED) {	\
    402 				RB_COLOR(tmp, field) = RB_BLACK;	\
    403 				RB_SET_BLACKRED(parent, gparent, field);\
    404 				elm = gparent;				\
    405 				continue;				\
    406 			}						\
    407 			if (RB_RIGHT(parent, field) == elm) {		\
    408 				RB_ROTATE_LEFT(head, parent, tmp, field);\
    409 				tmp = parent;				\
    410 				parent = elm;				\
    411 				elm = tmp;				\
    412 			}						\
    413 			RB_SET_BLACKRED(parent, gparent, field);	\
    414 			RB_ROTATE_RIGHT(head, gparent, tmp, field);	\
    415 		} else {						\
    416 			tmp = RB_LEFT(gparent, field);			\
    417 			if (tmp && RB_COLOR(tmp, field) == RB_RED) {	\
    418 				RB_COLOR(tmp, field) = RB_BLACK;	\
    419 				RB_SET_BLACKRED(parent, gparent, field);\
    420 				elm = gparent;				\
    421 				continue;				\
    422 			}						\
    423 			if (RB_LEFT(parent, field) == elm) {		\
    424 				RB_ROTATE_RIGHT(head, parent, tmp, field);\
    425 				tmp = parent;				\
    426 				parent = elm;				\
    427 				elm = tmp;				\
    428 			}						\
    429 			RB_SET_BLACKRED(parent, gparent, field);	\
    430 			RB_ROTATE_LEFT(head, gparent, tmp, field);	\
    431 		}							\
    432 	}								\
    433 	RB_COLOR(head->rbh_root, field) = RB_BLACK;			\
    434 }									\
    435 									\
    436 void									\
    437 name##_RB_REMOVE_COLOR(struct name *head, struct type *parent, struct type *elm) \
    438 {									\
    439 	struct type *tmp;						\
    440 	while ((elm == NULL || RB_COLOR(elm, field) == RB_BLACK) &&	\
    441 	    elm != RB_ROOT(head)) {					\
    442 		if (RB_LEFT(parent, field) == elm) {			\
    443 			tmp = RB_RIGHT(parent, field);			\
    444 			if (RB_COLOR(tmp, field) == RB_RED) {		\
    445 				RB_SET_BLACKRED(tmp, parent, field);	\
    446 				RB_ROTATE_LEFT(head, parent, tmp, field);\
    447 				tmp = RB_RIGHT(parent, field);		\
    448 			}						\
    449 			if ((RB_LEFT(tmp, field) == NULL ||		\
    450 			    RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
    451 			    (RB_RIGHT(tmp, field) == NULL ||		\
    452 			    RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
    453 				RB_COLOR(tmp, field) = RB_RED;		\
    454 				elm = parent;				\
    455 				parent = RB_PARENT(elm, field);		\
    456 			} else {					\
    457 				if (RB_RIGHT(tmp, field) == NULL ||	\
    458 				    RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK) {\
    459 					struct type *oleft;		\
    460 					if ((oleft = RB_LEFT(tmp, field)))\
    461 						RB_COLOR(oleft, field) = RB_BLACK;\
    462 					RB_COLOR(tmp, field) = RB_RED;	\
    463 					RB_ROTATE_RIGHT(head, tmp, oleft, field);\
    464 					tmp = RB_RIGHT(parent, field);	\
    465 				}					\
    466 				RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
    467 				RB_COLOR(parent, field) = RB_BLACK;	\
    468 				if (RB_RIGHT(tmp, field))		\
    469 					RB_COLOR(RB_RIGHT(tmp, field), field) = RB_BLACK;\
    470 				RB_ROTATE_LEFT(head, parent, tmp, field);\
    471 				elm = RB_ROOT(head);			\
    472 				break;					\
    473 			}						\
    474 		} else {						\
    475 			tmp = RB_LEFT(parent, field);			\
    476 			if (RB_COLOR(tmp, field) == RB_RED) {		\
    477 				RB_SET_BLACKRED(tmp, parent, field);	\
    478 				RB_ROTATE_RIGHT(head, parent, tmp, field);\
    479 				tmp = RB_LEFT(parent, field);		\
    480 			}						\
    481 			if ((RB_LEFT(tmp, field) == NULL ||		\
    482 			    RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
    483 			    (RB_RIGHT(tmp, field) == NULL ||		\
    484 			    RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
    485 				RB_COLOR(tmp, field) = RB_RED;		\
    486 				elm = parent;				\
    487 				parent = RB_PARENT(elm, field);		\
    488 			} else {					\
    489 				if (RB_LEFT(tmp, field) == NULL ||	\
    490 				    RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) {\
    491 					struct type *oright;		\
    492 					if ((oright = RB_RIGHT(tmp, field)))\
    493 						RB_COLOR(oright, field) = RB_BLACK;\
    494 					RB_COLOR(tmp, field) = RB_RED;	\
    495 					RB_ROTATE_LEFT(head, tmp, oright, field);\
    496 					tmp = RB_LEFT(parent, field);	\
    497 				}					\
    498 				RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
    499 				RB_COLOR(parent, field) = RB_BLACK;	\
    500 				if (RB_LEFT(tmp, field))		\
    501 					RB_COLOR(RB_LEFT(tmp, field), field) = RB_BLACK;\
    502 				RB_ROTATE_RIGHT(head, parent, tmp, field);\
    503 				elm = RB_ROOT(head);			\
    504 				break;					\
    505 			}						\
    506 		}							\
    507 	}								\
    508 	if (elm)							\
    509 		RB_COLOR(elm, field) = RB_BLACK;			\
    510 }									\
    511 									\
    512 struct type *								\
    513 name##_RB_REMOVE(struct name *head, struct type *elm)			\
    514 {									\
    515 	struct type *child, *parent, *old = elm;			\
    516 	int color;							\
    517 	if (RB_LEFT(elm, field) == NULL)				\
    518 		child = RB_RIGHT(elm, field);				\
    519 	else if (RB_RIGHT(elm, field) == NULL)				\
    520 		child = RB_LEFT(elm, field);				\
    521 	else {								\
    522 		struct type *left;					\
    523 		elm = RB_RIGHT(elm, field);				\
    524 		while ((left = RB_LEFT(elm, field)))			\
    525 			elm = left;					\
    526 		child = RB_RIGHT(elm, field);				\
    527 		parent = RB_PARENT(elm, field);				\
    528 		color = RB_COLOR(elm, field);				\
    529 		if (child)						\
    530 			RB_PARENT(child, field) = parent;		\
    531 		if (parent) {						\
    532 			if (RB_LEFT(parent, field) == elm)		\
    533 				RB_LEFT(parent, field) = child;		\
    534 			else						\
    535 				RB_RIGHT(parent, field) = child;	\
    536 			RB_AUGMENT(parent);				\
    537 		} else							\
    538 			RB_ROOT(head) = child;				\
    539 		if (RB_PARENT(elm, field) == old)			\
    540 			parent = elm;					\
    541 		(elm)->field = (old)->field;				\
    542 		if (RB_PARENT(old, field)) {				\
    543 			if (RB_LEFT(RB_PARENT(old, field), field) == old)\
    544 				RB_LEFT(RB_PARENT(old, field), field) = elm;\
    545 			else						\
    546 				RB_RIGHT(RB_PARENT(old, field), field) = elm;\
    547 			RB_AUGMENT(RB_PARENT(old, field));		\
    548 		} else							\
    549 			RB_ROOT(head) = elm;				\
    550 		RB_PARENT(RB_LEFT(old, field), field) = elm;		\
    551 		if (RB_RIGHT(old, field))				\
    552 			RB_PARENT(RB_RIGHT(old, field), field) = elm;	\
    553 		if (parent) {						\
    554 			left = parent;					\
    555 			do {						\
    556 				RB_AUGMENT(left);			\
    557 			} while ((left = RB_PARENT(left, field)));	\
    558 		}							\
    559 		goto color;						\
    560 	}								\
    561 	parent = RB_PARENT(elm, field);					\
    562 	color = RB_COLOR(elm, field);					\
    563 	if (child)							\
    564 		RB_PARENT(child, field) = parent;			\
    565 	if (parent) {							\
    566 		if (RB_LEFT(parent, field) == elm)			\
    567 			RB_LEFT(parent, field) = child;			\
    568 		else							\
    569 			RB_RIGHT(parent, field) = child;		\
    570 		RB_AUGMENT(parent);					\
    571 	} else								\
    572 		RB_ROOT(head) = child;					\
    573 color:									\
    574 	if (color == RB_BLACK)						\
    575 		name##_RB_REMOVE_COLOR(head, parent, child);		\
    576 	return (old);							\
    577 }									\
    578 									\
    579 /* Inserts a node into the RB tree */					\
    580 struct type *								\
    581 name##_RB_INSERT(struct name *head, struct type *elm)			\
    582 {									\
    583 	struct type *tmp;						\
    584 	struct type *parent = NULL;					\
    585 	int comp = 0;							\
    586 	tmp = RB_ROOT(head);						\
    587 	while (tmp) {							\
    588 		parent = tmp;						\
    589 		comp = (cmp)(elm, parent);				\
    590 		if (comp < 0)						\
    591 			tmp = RB_LEFT(tmp, field);			\
    592 		else if (comp > 0)					\
    593 			tmp = RB_RIGHT(tmp, field);			\
    594 		else							\
    595 			return (tmp);					\
    596 	}								\
    597 	RB_SET(elm, parent, field);					\
    598 	if (parent != NULL) {						\
    599 		if (comp < 0)						\
    600 			RB_LEFT(parent, field) = elm;			\
    601 		else							\
    602 			RB_RIGHT(parent, field) = elm;			\
    603 		RB_AUGMENT(parent);					\
    604 	} else								\
    605 		RB_ROOT(head) = elm;					\
    606 	name##_RB_INSERT_COLOR(head, elm);				\
    607 	return (NULL);							\
    608 }									\
    609 									\
    610 /* Finds the node with the same key as elm */				\
    611 struct type *								\
    612 name##_RB_FIND(struct name *head, struct type *elm)			\
    613 {									\
    614 	struct type *tmp = RB_ROOT(head);				\
    615 	int comp;							\
    616 	while (tmp) {							\
    617 		comp = cmp(elm, tmp);					\
    618 		if (comp < 0)						\
    619 			tmp = RB_LEFT(tmp, field);			\
    620 		else if (comp > 0)					\
    621 			tmp = RB_RIGHT(tmp, field);			\
    622 		else							\
    623 			return (tmp);					\
    624 	}								\
    625 	return (NULL);							\
    626 }									\
    627 									\
    628 struct type *								\
    629 name##_RB_NEXT(struct type *elm)					\
    630 {									\
    631 	if (RB_RIGHT(elm, field)) {					\
    632 		elm = RB_RIGHT(elm, field);				\
    633 		while (RB_LEFT(elm, field))				\
    634 			elm = RB_LEFT(elm, field);			\
    635 	} else {							\
    636 		if (RB_PARENT(elm, field) &&				\
    637 		    (elm == RB_LEFT(RB_PARENT(elm, field), field)))	\
    638 			elm = RB_PARENT(elm, field);			\
    639 		else {							\
    640 			while (RB_PARENT(elm, field) &&			\
    641 			    (elm == RB_RIGHT(RB_PARENT(elm, field), field)))\
    642 				elm = RB_PARENT(elm, field);		\
    643 			elm = RB_PARENT(elm, field);			\
    644 		}							\
    645 	}								\
    646 	return (elm);							\
    647 }									\
    648 									\
    649 struct type *								\
    650 name##_RB_MINMAX(struct name *head, int val)				\
    651 {									\
    652 	struct type *tmp = RB_ROOT(head);				\
    653 	struct type *parent = NULL;					\
    654 	while (tmp) {							\
    655 		parent = tmp;						\
    656 		if (val < 0)						\
    657 			tmp = RB_LEFT(tmp, field);			\
    658 		else							\
    659 			tmp = RB_RIGHT(tmp, field);			\
    660 	}								\
    661 	return (parent);						\
    662 }
    663 
    664 #define RB_NEGINF	-1
    665 #define RB_INF	1
    666 
    667 #define RB_INSERT(name, x, y)	name##_RB_INSERT(x, y)
    668 #define RB_REMOVE(name, x, y)	name##_RB_REMOVE(x, y)
    669 #define RB_FIND(name, x, y)	name##_RB_FIND(x, y)
    670 #define RB_NEXT(name, x, y)	name##_RB_NEXT(y)
    671 #define RB_MIN(name, x)		name##_RB_MINMAX(x, RB_NEGINF)
    672 #define RB_MAX(name, x)		name##_RB_MINMAX(x, RB_INF)
    673 
    674 #define RB_FOREACH(x, name, head)					\
    675 	for ((x) = RB_MIN(name, head);					\
    676 	     (x) != NULL;						\
    677 	     (x) = name##_RB_NEXT(x))
    678 
    679 #endif	/* _SYS_TREE_H_ */
    680