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tree.h revision 1.1.1.1.8.2
      1 /*	$NetBSD: tree.h,v 1.1.1.1.8.2 2014/08/19 23:51:46 tls Exp $	*/
      2 
      3 /*	$OpenBSD: tree.h,v 1.7 2002/10/17 21:51:54 art Exp $	*/
      4 /*
      5  * Copyright 2002 Niels Provos <provos (at) citi.umich.edu>
      6  * All rights reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  *
     17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27  */
     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-back 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 /*	$OpenBSD: tree.h,v 1.7 2002/10/17 21:51:54 art Exp $	*/
    681 /*
    682  * Copyright 2002 Niels Provos <provos (at) citi.umich.edu>
    683  * All rights reserved.
    684  *
    685  * Redistribution and use in source and binary forms, with or without
    686  * modification, are permitted provided that the following conditions
    687  * are met:
    688  * 1. Redistributions of source code must retain the above copyright
    689  *    notice, this list of conditions and the following disclaimer.
    690  * 2. Redistributions in binary form must reproduce the above copyright
    691  *    notice, this list of conditions and the following disclaimer in the
    692  *    documentation and/or other materials provided with the distribution.
    693  *
    694  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
    695  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
    696  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
    697  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
    698  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
    699  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    700  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    701  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    702  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
    703  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    704  */
    705 
    706 #ifndef	_SYS_TREE_H_
    707 #define	_SYS_TREE_H_
    708 
    709 /*
    710  * This file defines data structures for different types of trees:
    711  * splay trees and red-black trees.
    712  *
    713  * A splay tree is a self-organizing data structure.  Every operation
    714  * on the tree causes a splay to happen.  The splay moves the requested
    715  * node to the root of the tree and partly rebalances it.
    716  *
    717  * This has the benefit that request locality causes faster lookups as
    718  * the requested nodes move to the top of the tree.  On the other hand,
    719  * every lookup causes memory writes.
    720  *
    721  * The Balance Theorem bounds the total access time for m operations
    722  * and n inserts on an initially empty tree as O((m + n)lg n).  The
    723  * amortized cost for a sequence of m accesses to a splay tree is O(lg n);
    724  *
    725  * A red-black tree is a binary search tree with the node color as an
    726  * extra attribute.  It fulfills a set of conditions:
    727  *	- every search path from the root to a leaf consists of the
    728  *	  same number of black nodes,
    729  *	- each red node (except for the root) has a black parent,
    730  *	- each leaf node is black.
    731  *
    732  * Every operation on a red-black tree is bounded as O(lg n).
    733  * The maximum height of a red-black tree is 2lg (n+1).
    734  */
    735 
    736 #define SPLAY_HEAD(name, type)						\
    737 struct name {								\
    738 	struct type *sph_root; /* root of the tree */			\
    739 }
    740 
    741 #define SPLAY_INITIALIZER(root)						\
    742 	{ NULL }
    743 
    744 #define SPLAY_INIT(root) do {						\
    745 	(root)->sph_root = NULL;					\
    746 } while (0)
    747 
    748 #define SPLAY_ENTRY(type)						\
    749 struct {								\
    750 	struct type *spe_left; /* left element */			\
    751 	struct type *spe_right; /* right element */			\
    752 }
    753 
    754 #define SPLAY_LEFT(elm, field)		(elm)->field.spe_left
    755 #define SPLAY_RIGHT(elm, field)		(elm)->field.spe_right
    756 #define SPLAY_ROOT(head)		(head)->sph_root
    757 #define SPLAY_EMPTY(head)		(SPLAY_ROOT(head) == NULL)
    758 
    759 /* SPLAY_ROTATE_{LEFT,RIGHT} expect that tmp hold SPLAY_{RIGHT,LEFT} */
    760 #define SPLAY_ROTATE_RIGHT(head, tmp, field) do {			\
    761 	SPLAY_LEFT((head)->sph_root, field) = SPLAY_RIGHT(tmp, field);	\
    762 	SPLAY_RIGHT(tmp, field) = (head)->sph_root;			\
    763 	(head)->sph_root = tmp;						\
    764 } while (0)
    765 
    766 #define SPLAY_ROTATE_LEFT(head, tmp, field) do {			\
    767 	SPLAY_RIGHT((head)->sph_root, field) = SPLAY_LEFT(tmp, field);	\
    768 	SPLAY_LEFT(tmp, field) = (head)->sph_root;			\
    769 	(head)->sph_root = tmp;						\
    770 } while (0)
    771 
    772 #define SPLAY_LINKLEFT(head, tmp, field) do {				\
    773 	SPLAY_LEFT(tmp, field) = (head)->sph_root;			\
    774 	tmp = (head)->sph_root;						\
    775 	(head)->sph_root = SPLAY_LEFT((head)->sph_root, field);		\
    776 } while (0)
    777 
    778 #define SPLAY_LINKRIGHT(head, tmp, field) do {				\
    779 	SPLAY_RIGHT(tmp, field) = (head)->sph_root;			\
    780 	tmp = (head)->sph_root;						\
    781 	(head)->sph_root = SPLAY_RIGHT((head)->sph_root, field);	\
    782 } while (0)
    783 
    784 #define SPLAY_ASSEMBLE(head, node, left, right, field) do {		\
    785 	SPLAY_RIGHT(left, field) = SPLAY_LEFT((head)->sph_root, field);	\
    786 	SPLAY_LEFT(right, field) = SPLAY_RIGHT((head)->sph_root, field);\
    787 	SPLAY_LEFT((head)->sph_root, field) = SPLAY_RIGHT(node, field);	\
    788 	SPLAY_RIGHT((head)->sph_root, field) = SPLAY_LEFT(node, field);	\
    789 } while (0)
    790 
    791 /* Generates prototypes and inline functions */
    792 
    793 #define SPLAY_PROTOTYPE(name, type, field, cmp)				\
    794 void name##_SPLAY(struct name *, struct type *);			\
    795 void name##_SPLAY_MINMAX(struct name *, int);				\
    796 struct type *name##_SPLAY_INSERT(struct name *, struct type *);		\
    797 struct type *name##_SPLAY_REMOVE(struct name *, struct type *);		\
    798 									\
    799 /* Finds the node with the same key as elm */				\
    800 static __inline struct type *						\
    801 name##_SPLAY_FIND(struct name *head, struct type *elm)			\
    802 {									\
    803 	if (SPLAY_EMPTY(head))						\
    804 		return(NULL);						\
    805 	name##_SPLAY(head, elm);					\
    806 	if ((cmp)(elm, (head)->sph_root) == 0)				\
    807 		return (head->sph_root);				\
    808 	return (NULL);							\
    809 }									\
    810 									\
    811 static __inline struct type *						\
    812 name##_SPLAY_NEXT(struct name *head, struct type *elm)			\
    813 {									\
    814 	name##_SPLAY(head, elm);					\
    815 	if (SPLAY_RIGHT(elm, field) != NULL) {				\
    816 		elm = SPLAY_RIGHT(elm, field);				\
    817 		while (SPLAY_LEFT(elm, field) != NULL) {		\
    818 			elm = SPLAY_LEFT(elm, field);			\
    819 		}							\
    820 	} else								\
    821 		elm = NULL;						\
    822 	return (elm);							\
    823 }									\
    824 									\
    825 static __inline struct type *						\
    826 name##_SPLAY_MIN_MAX(struct name *head, int val)			\
    827 {									\
    828 	name##_SPLAY_MINMAX(head, val);					\
    829 	return (SPLAY_ROOT(head));					\
    830 }
    831 
    832 /* Main splay operation.
    833  * Moves node close to the key of elm to top
    834  */
    835 #define SPLAY_GENERATE(name, type, field, cmp)				\
    836 struct type *								\
    837 name##_SPLAY_INSERT(struct name *head, struct type *elm)		\
    838 {									\
    839     if (SPLAY_EMPTY(head)) {						\
    840 	    SPLAY_LEFT(elm, field) = SPLAY_RIGHT(elm, field) = NULL;	\
    841     } else {								\
    842 	    int __comp;							\
    843 	    name##_SPLAY(head, elm);					\
    844 	    __comp = (cmp)(elm, (head)->sph_root);			\
    845 	    if(__comp < 0) {						\
    846 		    SPLAY_LEFT(elm, field) = SPLAY_LEFT((head)->sph_root, field);\
    847 		    SPLAY_RIGHT(elm, field) = (head)->sph_root;		\
    848 		    SPLAY_LEFT((head)->sph_root, field) = NULL;		\
    849 	    } else if (__comp > 0) {					\
    850 		    SPLAY_RIGHT(elm, field) = SPLAY_RIGHT((head)->sph_root, field);\
    851 		    SPLAY_LEFT(elm, field) = (head)->sph_root;		\
    852 		    SPLAY_RIGHT((head)->sph_root, field) = NULL;	\
    853 	    } else							\
    854 		    return ((head)->sph_root);				\
    855     }									\
    856     (head)->sph_root = (elm);						\
    857     return (NULL);							\
    858 }									\
    859 									\
    860 struct type *								\
    861 name##_SPLAY_REMOVE(struct name *head, struct type *elm)		\
    862 {									\
    863 	struct type *__tmp;						\
    864 	if (SPLAY_EMPTY(head))						\
    865 		return (NULL);						\
    866 	name##_SPLAY(head, elm);					\
    867 	if ((cmp)(elm, (head)->sph_root) == 0) {			\
    868 		if (SPLAY_LEFT((head)->sph_root, field) == NULL) {	\
    869 			(head)->sph_root = SPLAY_RIGHT((head)->sph_root, field);\
    870 		} else {						\
    871 			__tmp = SPLAY_RIGHT((head)->sph_root, field);	\
    872 			(head)->sph_root = SPLAY_LEFT((head)->sph_root, field);\
    873 			name##_SPLAY(head, elm);			\
    874 			SPLAY_RIGHT((head)->sph_root, field) = __tmp;	\
    875 		}							\
    876 		return (elm);						\
    877 	}								\
    878 	return (NULL);							\
    879 }									\
    880 									\
    881 void									\
    882 name##_SPLAY(struct name *head, struct type *elm)			\
    883 {									\
    884 	struct type __node, *__left, *__right, *__tmp;			\
    885 	int __comp;							\
    886 \
    887 	SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = NULL;\
    888 	__left = __right = &__node;					\
    889 \
    890 	while ((__comp = (cmp)(elm, (head)->sph_root))) {		\
    891 		if (__comp < 0) {					\
    892 			__tmp = SPLAY_LEFT((head)->sph_root, field);	\
    893 			if (__tmp == NULL)				\
    894 				break;					\
    895 			if ((cmp)(elm, __tmp) < 0){			\
    896 				SPLAY_ROTATE_RIGHT(head, __tmp, field);	\
    897 				if (SPLAY_LEFT((head)->sph_root, field) == NULL)\
    898 					break;				\
    899 			}						\
    900 			SPLAY_LINKLEFT(head, __right, field);		\
    901 		} else if (__comp > 0) {				\
    902 			__tmp = SPLAY_RIGHT((head)->sph_root, field);	\
    903 			if (__tmp == NULL)				\
    904 				break;					\
    905 			if ((cmp)(elm, __tmp) > 0){			\
    906 				SPLAY_ROTATE_LEFT(head, __tmp, field);	\
    907 				if (SPLAY_RIGHT((head)->sph_root, field) == NULL)\
    908 					break;				\
    909 			}						\
    910 			SPLAY_LINKRIGHT(head, __left, field);		\
    911 		}							\
    912 	}								\
    913 	SPLAY_ASSEMBLE(head, &__node, __left, __right, field);		\
    914 }									\
    915 									\
    916 /* Splay with either the minimum or the maximum element			\
    917  * Used to find minimum or maximum element in tree.			\
    918  */									\
    919 void name##_SPLAY_MINMAX(struct name *head, int __comp) \
    920 {									\
    921 	struct type __node, *__left, *__right, *__tmp;			\
    922 \
    923 	SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = NULL;\
    924 	__left = __right = &__node;					\
    925 \
    926 	while (1) {							\
    927 		if (__comp < 0) {					\
    928 			__tmp = SPLAY_LEFT((head)->sph_root, field);	\
    929 			if (__tmp == NULL)				\
    930 				break;					\
    931 			if (__comp < 0){				\
    932 				SPLAY_ROTATE_RIGHT(head, __tmp, field);	\
    933 				if (SPLAY_LEFT((head)->sph_root, field) == NULL)\
    934 					break;				\
    935 			}						\
    936 			SPLAY_LINKLEFT(head, __right, field);		\
    937 		} else if (__comp > 0) {				\
    938 			__tmp = SPLAY_RIGHT((head)->sph_root, field);	\
    939 			if (__tmp == NULL)				\
    940 				break;					\
    941 			if (__comp > 0) {				\
    942 				SPLAY_ROTATE_LEFT(head, __tmp, field);	\
    943 				if (SPLAY_RIGHT((head)->sph_root, field) == NULL)\
    944 					break;				\
    945 			}						\
    946 			SPLAY_LINKRIGHT(head, __left, field);		\
    947 		}							\
    948 	}								\
    949 	SPLAY_ASSEMBLE(head, &__node, __left, __right, field);		\
    950 }
    951 
    952 #define SPLAY_NEGINF	-1
    953 #define SPLAY_INF	1
    954 
    955 #define SPLAY_INSERT(name, x, y)	name##_SPLAY_INSERT(x, y)
    956 #define SPLAY_REMOVE(name, x, y)	name##_SPLAY_REMOVE(x, y)
    957 #define SPLAY_FIND(name, x, y)		name##_SPLAY_FIND(x, y)
    958 #define SPLAY_NEXT(name, x, y)		name##_SPLAY_NEXT(x, y)
    959 #define SPLAY_MIN(name, x)		(SPLAY_EMPTY(x) ? NULL	\
    960 					: name##_SPLAY_MIN_MAX(x, SPLAY_NEGINF))
    961 #define SPLAY_MAX(name, x)		(SPLAY_EMPTY(x) ? NULL	\
    962 					: name##_SPLAY_MIN_MAX(x, SPLAY_INF))
    963 
    964 #define SPLAY_FOREACH(x, name, head)					\
    965 	for ((x) = SPLAY_MIN(name, head);				\
    966 	     (x) != NULL;						\
    967 	     (x) = SPLAY_NEXT(name, head, x))
    968 
    969 /* Macros that define a red-back tree */
    970 #define RB_HEAD(name, type)						\
    971 struct name {								\
    972 	struct type *rbh_root; /* root of the tree */			\
    973 }
    974 
    975 #define RB_INITIALIZER(root)						\
    976 	{ NULL }
    977 
    978 #define RB_INIT(root) do {						\
    979 	(root)->rbh_root = NULL;					\
    980 } while (0)
    981 
    982 #define RB_BLACK	0
    983 #define RB_RED		1
    984 #define RB_ENTRY(type)							\
    985 struct {								\
    986 	struct type *rbe_left;		/* left element */		\
    987 	struct type *rbe_right;		/* right element */		\
    988 	struct type *rbe_parent;	/* parent element */		\
    989 	int rbe_color;			/* node color */		\
    990 }
    991 
    992 #define RB_LEFT(elm, field)		(elm)->field.rbe_left
    993 #define RB_RIGHT(elm, field)		(elm)->field.rbe_right
    994 #define RB_PARENT(elm, field)		(elm)->field.rbe_parent
    995 #define RB_COLOR(elm, field)		(elm)->field.rbe_color
    996 #define RB_ROOT(head)			(head)->rbh_root
    997 #define RB_EMPTY(head)			(RB_ROOT(head) == NULL)
    998 
    999 #define RB_SET(elm, parent, field) do {					\
   1000 	RB_PARENT(elm, field) = parent;					\
   1001 	RB_LEFT(elm, field) = RB_RIGHT(elm, field) = NULL;		\
   1002 	RB_COLOR(elm, field) = RB_RED;					\
   1003 } while (0)
   1004 
   1005 #define RB_SET_BLACKRED(black, red, field) do {				\
   1006 	RB_COLOR(black, field) = RB_BLACK;				\
   1007 	RB_COLOR(red, field) = RB_RED;					\
   1008 } while (0)
   1009 
   1010 #ifndef RB_AUGMENT
   1011 #define RB_AUGMENT(x)
   1012 #endif
   1013 
   1014 #define RB_ROTATE_LEFT(head, elm, tmp, field) do {			\
   1015 	(tmp) = RB_RIGHT(elm, field);					\
   1016 	if ((RB_RIGHT(elm, field) = RB_LEFT(tmp, field))) {		\
   1017 		RB_PARENT(RB_LEFT(tmp, field), field) = (elm);		\
   1018 	}								\
   1019 	RB_AUGMENT(elm);						\
   1020 	if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field))) {		\
   1021 		if ((elm) == RB_LEFT(RB_PARENT(elm, field), field))	\
   1022 			RB_LEFT(RB_PARENT(elm, field), field) = (tmp);	\
   1023 		else							\
   1024 			RB_RIGHT(RB_PARENT(elm, field), field) = (tmp);	\
   1025 	} else								\
   1026 		(head)->rbh_root = (tmp);				\
   1027 	RB_LEFT(tmp, field) = (elm);					\
   1028 	RB_PARENT(elm, field) = (tmp);					\
   1029 	RB_AUGMENT(tmp);						\
   1030 	if ((RB_PARENT(tmp, field)))					\
   1031 		RB_AUGMENT(RB_PARENT(tmp, field));			\
   1032 } while (0)
   1033 
   1034 #define RB_ROTATE_RIGHT(head, elm, tmp, field) do {			\
   1035 	(tmp) = RB_LEFT(elm, field);					\
   1036 	if ((RB_LEFT(elm, field) = RB_RIGHT(tmp, field))) {		\
   1037 		RB_PARENT(RB_RIGHT(tmp, field), field) = (elm);		\
   1038 	}								\
   1039 	RB_AUGMENT(elm);						\
   1040 	if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field))) {		\
   1041 		if ((elm) == RB_LEFT(RB_PARENT(elm, field), field))	\
   1042 			RB_LEFT(RB_PARENT(elm, field), field) = (tmp);	\
   1043 		else							\
   1044 			RB_RIGHT(RB_PARENT(elm, field), field) = (tmp);	\
   1045 	} else								\
   1046 		(head)->rbh_root = (tmp);				\
   1047 	RB_RIGHT(tmp, field) = (elm);					\
   1048 	RB_PARENT(elm, field) = (tmp);					\
   1049 	RB_AUGMENT(tmp);						\
   1050 	if ((RB_PARENT(tmp, field)))					\
   1051 		RB_AUGMENT(RB_PARENT(tmp, field));			\
   1052 } while (0)
   1053 
   1054 /* Generates prototypes and inline functions */
   1055 #define RB_PROTOTYPE(name, type, field, cmp)				\
   1056 void name##_RB_INSERT_COLOR(struct name *, struct type *);	\
   1057 void name##_RB_REMOVE_COLOR(struct name *, struct type *, struct type *);\
   1058 struct type *name##_RB_REMOVE(struct name *, struct type *);		\
   1059 struct type *name##_RB_INSERT(struct name *, struct type *);		\
   1060 struct type *name##_RB_FIND(struct name *, struct type *);		\
   1061 struct type *name##_RB_NEXT(struct type *);				\
   1062 struct type *name##_RB_MINMAX(struct name *, int);			\
   1063 									\
   1064 
   1065 /* Main rb operation.
   1066  * Moves node close to the key of elm to top
   1067  */
   1068 #define RB_GENERATE(name, type, field, cmp)				\
   1069 void									\
   1070 name##_RB_INSERT_COLOR(struct name *head, struct type *elm)		\
   1071 {									\
   1072 	struct type *parent, *gparent, *tmp;				\
   1073 	while ((parent = RB_PARENT(elm, field)) &&			\
   1074 	    RB_COLOR(parent, field) == RB_RED) {			\
   1075 		gparent = RB_PARENT(parent, field);			\
   1076 		if (parent == RB_LEFT(gparent, field)) {		\
   1077 			tmp = RB_RIGHT(gparent, field);			\
   1078 			if (tmp && RB_COLOR(tmp, field) == RB_RED) {	\
   1079 				RB_COLOR(tmp, field) = RB_BLACK;	\
   1080 				RB_SET_BLACKRED(parent, gparent, field);\
   1081 				elm = gparent;				\
   1082 				continue;				\
   1083 			}						\
   1084 			if (RB_RIGHT(parent, field) == elm) {		\
   1085 				RB_ROTATE_LEFT(head, parent, tmp, field);\
   1086 				tmp = parent;				\
   1087 				parent = elm;				\
   1088 				elm = tmp;				\
   1089 			}						\
   1090 			RB_SET_BLACKRED(parent, gparent, field);	\
   1091 			RB_ROTATE_RIGHT(head, gparent, tmp, field);	\
   1092 		} else {						\
   1093 			tmp = RB_LEFT(gparent, field);			\
   1094 			if (tmp && RB_COLOR(tmp, field) == RB_RED) {	\
   1095 				RB_COLOR(tmp, field) = RB_BLACK;	\
   1096 				RB_SET_BLACKRED(parent, gparent, field);\
   1097 				elm = gparent;				\
   1098 				continue;				\
   1099 			}						\
   1100 			if (RB_LEFT(parent, field) == elm) {		\
   1101 				RB_ROTATE_RIGHT(head, parent, tmp, field);\
   1102 				tmp = parent;				\
   1103 				parent = elm;				\
   1104 				elm = tmp;				\
   1105 			}						\
   1106 			RB_SET_BLACKRED(parent, gparent, field);	\
   1107 			RB_ROTATE_LEFT(head, gparent, tmp, field);	\
   1108 		}							\
   1109 	}								\
   1110 	RB_COLOR(head->rbh_root, field) = RB_BLACK;			\
   1111 }									\
   1112 									\
   1113 void									\
   1114 name##_RB_REMOVE_COLOR(struct name *head, struct type *parent, struct type *elm) \
   1115 {									\
   1116 	struct type *tmp;						\
   1117 	while ((elm == NULL || RB_COLOR(elm, field) == RB_BLACK) &&	\
   1118 	    elm != RB_ROOT(head)) {					\
   1119 		if (RB_LEFT(parent, field) == elm) {			\
   1120 			tmp = RB_RIGHT(parent, field);			\
   1121 			if (RB_COLOR(tmp, field) == RB_RED) {		\
   1122 				RB_SET_BLACKRED(tmp, parent, field);	\
   1123 				RB_ROTATE_LEFT(head, parent, tmp, field);\
   1124 				tmp = RB_RIGHT(parent, field);		\
   1125 			}						\
   1126 			if ((RB_LEFT(tmp, field) == NULL ||		\
   1127 			    RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
   1128 			    (RB_RIGHT(tmp, field) == NULL ||		\
   1129 			    RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
   1130 				RB_COLOR(tmp, field) = RB_RED;		\
   1131 				elm = parent;				\
   1132 				parent = RB_PARENT(elm, field);		\
   1133 			} else {					\
   1134 				if (RB_RIGHT(tmp, field) == NULL ||	\
   1135 				    RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK) {\
   1136 					struct type *oleft;		\
   1137 					if ((oleft = RB_LEFT(tmp, field)))\
   1138 						RB_COLOR(oleft, field) = RB_BLACK;\
   1139 					RB_COLOR(tmp, field) = RB_RED;	\
   1140 					RB_ROTATE_RIGHT(head, tmp, oleft, field);\
   1141 					tmp = RB_RIGHT(parent, field);	\
   1142 				}					\
   1143 				RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
   1144 				RB_COLOR(parent, field) = RB_BLACK;	\
   1145 				if (RB_RIGHT(tmp, field))		\
   1146 					RB_COLOR(RB_RIGHT(tmp, field), field) = RB_BLACK;\
   1147 				RB_ROTATE_LEFT(head, parent, tmp, field);\
   1148 				elm = RB_ROOT(head);			\
   1149 				break;					\
   1150 			}						\
   1151 		} else {						\
   1152 			tmp = RB_LEFT(parent, field);			\
   1153 			if (RB_COLOR(tmp, field) == RB_RED) {		\
   1154 				RB_SET_BLACKRED(tmp, parent, field);	\
   1155 				RB_ROTATE_RIGHT(head, parent, tmp, field);\
   1156 				tmp = RB_LEFT(parent, field);		\
   1157 			}						\
   1158 			if ((RB_LEFT(tmp, field) == NULL ||		\
   1159 			    RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
   1160 			    (RB_RIGHT(tmp, field) == NULL ||		\
   1161 			    RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
   1162 				RB_COLOR(tmp, field) = RB_RED;		\
   1163 				elm = parent;				\
   1164 				parent = RB_PARENT(elm, field);		\
   1165 			} else {					\
   1166 				if (RB_LEFT(tmp, field) == NULL ||	\
   1167 				    RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) {\
   1168 					struct type *oright;		\
   1169 					if ((oright = RB_RIGHT(tmp, field)))\
   1170 						RB_COLOR(oright, field) = RB_BLACK;\
   1171 					RB_COLOR(tmp, field) = RB_RED;	\
   1172 					RB_ROTATE_LEFT(head, tmp, oright, field);\
   1173 					tmp = RB_LEFT(parent, field);	\
   1174 				}					\
   1175 				RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
   1176 				RB_COLOR(parent, field) = RB_BLACK;	\
   1177 				if (RB_LEFT(tmp, field))		\
   1178 					RB_COLOR(RB_LEFT(tmp, field), field) = RB_BLACK;\
   1179 				RB_ROTATE_RIGHT(head, parent, tmp, field);\
   1180 				elm = RB_ROOT(head);			\
   1181 				break;					\
   1182 			}						\
   1183 		}							\
   1184 	}								\
   1185 	if (elm)							\
   1186 		RB_COLOR(elm, field) = RB_BLACK;			\
   1187 }									\
   1188 									\
   1189 struct type *								\
   1190 name##_RB_REMOVE(struct name *head, struct type *elm)			\
   1191 {									\
   1192 	struct type *child, *parent, *old = elm;			\
   1193 	int color;							\
   1194 	if (RB_LEFT(elm, field) == NULL)				\
   1195 		child = RB_RIGHT(elm, field);				\
   1196 	else if (RB_RIGHT(elm, field) == NULL)				\
   1197 		child = RB_LEFT(elm, field);				\
   1198 	else {								\
   1199 		struct type *left;					\
   1200 		elm = RB_RIGHT(elm, field);				\
   1201 		while ((left = RB_LEFT(elm, field)))			\
   1202 			elm = left;					\
   1203 		child = RB_RIGHT(elm, field);				\
   1204 		parent = RB_PARENT(elm, field);				\
   1205 		color = RB_COLOR(elm, field);				\
   1206 		if (child)						\
   1207 			RB_PARENT(child, field) = parent;		\
   1208 		if (parent) {						\
   1209 			if (RB_LEFT(parent, field) == elm)		\
   1210 				RB_LEFT(parent, field) = child;		\
   1211 			else						\
   1212 				RB_RIGHT(parent, field) = child;	\
   1213 			RB_AUGMENT(parent);				\
   1214 		} else							\
   1215 			RB_ROOT(head) = child;				\
   1216 		if (RB_PARENT(elm, field) == old)			\
   1217 			parent = elm;					\
   1218 		(elm)->field = (old)->field;				\
   1219 		if (RB_PARENT(old, field)) {				\
   1220 			if (RB_LEFT(RB_PARENT(old, field), field) == old)\
   1221 				RB_LEFT(RB_PARENT(old, field), field) = elm;\
   1222 			else						\
   1223 				RB_RIGHT(RB_PARENT(old, field), field) = elm;\
   1224 			RB_AUGMENT(RB_PARENT(old, field));		\
   1225 		} else							\
   1226 			RB_ROOT(head) = elm;				\
   1227 		RB_PARENT(RB_LEFT(old, field), field) = elm;		\
   1228 		if (RB_RIGHT(old, field))				\
   1229 			RB_PARENT(RB_RIGHT(old, field), field) = elm;	\
   1230 		if (parent) {						\
   1231 			left = parent;					\
   1232 			do {						\
   1233 				RB_AUGMENT(left);			\
   1234 			} while ((left = RB_PARENT(left, field)));	\
   1235 		}							\
   1236 		goto color;						\
   1237 	}								\
   1238 	parent = RB_PARENT(elm, field);					\
   1239 	color = RB_COLOR(elm, field);					\
   1240 	if (child)							\
   1241 		RB_PARENT(child, field) = parent;			\
   1242 	if (parent) {							\
   1243 		if (RB_LEFT(parent, field) == elm)			\
   1244 			RB_LEFT(parent, field) = child;			\
   1245 		else							\
   1246 			RB_RIGHT(parent, field) = child;		\
   1247 		RB_AUGMENT(parent);					\
   1248 	} else								\
   1249 		RB_ROOT(head) = child;					\
   1250 color:									\
   1251 	if (color == RB_BLACK)						\
   1252 		name##_RB_REMOVE_COLOR(head, parent, child);		\
   1253 	return (old);							\
   1254 }									\
   1255 									\
   1256 /* Inserts a node into the RB tree */					\
   1257 struct type *								\
   1258 name##_RB_INSERT(struct name *head, struct type *elm)			\
   1259 {									\
   1260 	struct type *tmp;						\
   1261 	struct type *parent = NULL;					\
   1262 	int comp = 0;							\
   1263 	tmp = RB_ROOT(head);						\
   1264 	while (tmp) {							\
   1265 		parent = tmp;						\
   1266 		comp = (cmp)(elm, parent);				\
   1267 		if (comp < 0)						\
   1268 			tmp = RB_LEFT(tmp, field);			\
   1269 		else if (comp > 0)					\
   1270 			tmp = RB_RIGHT(tmp, field);			\
   1271 		else							\
   1272 			return (tmp);					\
   1273 	}								\
   1274 	RB_SET(elm, parent, field);					\
   1275 	if (parent != NULL) {						\
   1276 		if (comp < 0)						\
   1277 			RB_LEFT(parent, field) = elm;			\
   1278 		else							\
   1279 			RB_RIGHT(parent, field) = elm;			\
   1280 		RB_AUGMENT(parent);					\
   1281 	} else								\
   1282 		RB_ROOT(head) = elm;					\
   1283 	name##_RB_INSERT_COLOR(head, elm);				\
   1284 	return (NULL);							\
   1285 }									\
   1286 									\
   1287 /* Finds the node with the same key as elm */				\
   1288 struct type *								\
   1289 name##_RB_FIND(struct name *head, struct type *elm)			\
   1290 {									\
   1291 	struct type *tmp = RB_ROOT(head);				\
   1292 	int comp;							\
   1293 	while (tmp) {							\
   1294 		comp = cmp(elm, tmp);					\
   1295 		if (comp < 0)						\
   1296 			tmp = RB_LEFT(tmp, field);			\
   1297 		else if (comp > 0)					\
   1298 			tmp = RB_RIGHT(tmp, field);			\
   1299 		else							\
   1300 			return (tmp);					\
   1301 	}								\
   1302 	return (NULL);							\
   1303 }									\
   1304 									\
   1305 struct type *								\
   1306 name##_RB_NEXT(struct type *elm)					\
   1307 {									\
   1308 	if (RB_RIGHT(elm, field)) {					\
   1309 		elm = RB_RIGHT(elm, field);				\
   1310 		while (RB_LEFT(elm, field))				\
   1311 			elm = RB_LEFT(elm, field);			\
   1312 	} else {							\
   1313 		if (RB_PARENT(elm, field) &&				\
   1314 		    (elm == RB_LEFT(RB_PARENT(elm, field), field)))	\
   1315 			elm = RB_PARENT(elm, field);			\
   1316 		else {							\
   1317 			while (RB_PARENT(elm, field) &&			\
   1318 			    (elm == RB_RIGHT(RB_PARENT(elm, field), field)))\
   1319 				elm = RB_PARENT(elm, field);		\
   1320 			elm = RB_PARENT(elm, field);			\
   1321 		}							\
   1322 	}								\
   1323 	return (elm);							\
   1324 }									\
   1325 									\
   1326 struct type *								\
   1327 name##_RB_MINMAX(struct name *head, int val)				\
   1328 {									\
   1329 	struct type *tmp = RB_ROOT(head);				\
   1330 	struct type *parent = NULL;					\
   1331 	while (tmp) {							\
   1332 		parent = tmp;						\
   1333 		if (val < 0)						\
   1334 			tmp = RB_LEFT(tmp, field);			\
   1335 		else							\
   1336 			tmp = RB_RIGHT(tmp, field);			\
   1337 	}								\
   1338 	return (parent);						\
   1339 }
   1340 
   1341 #define RB_NEGINF	-1
   1342 #define RB_INF	1
   1343 
   1344 #define RB_INSERT(name, x, y)	name##_RB_INSERT(x, y)
   1345 #define RB_REMOVE(name, x, y)	name##_RB_REMOVE(x, y)
   1346 #define RB_FIND(name, x, y)	name##_RB_FIND(x, y)
   1347 #define RB_NEXT(name, x, y)	name##_RB_NEXT(y)
   1348 #define RB_MIN(name, x)		name##_RB_MINMAX(x, RB_NEGINF)
   1349 #define RB_MAX(name, x)		name##_RB_MINMAX(x, RB_INF)
   1350 
   1351 #define RB_FOREACH(x, name, head)					\
   1352 	for ((x) = RB_MIN(name, head);					\
   1353 	     (x) != NULL;						\
   1354 	     (x) = name##_RB_NEXT(x))
   1355 
   1356 #endif	/* _SYS_TREE_H_ */
   1357