tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
Log | Files | Refs | README | LICENSE

tree.h (22646B)


      1 /*	$OpenBSD: tree.h,v 1.7 2002/10/17 21:51:54 art Exp $	*/
      2 /*
      3 * Copyright 2002 Niels Provos <provos@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 #ifndef	_SYS_TREE_H_
     28 #define	_SYS_TREE_H_
     29 
     30 /*
     31 * This file defines data structures for different types of trees:
     32 * splay trees and red-black trees.
     33 *
     34 * A splay tree is a self-organizing data structure.  Every operation
     35 * on the tree causes a splay to happen.  The splay moves the requested
     36 * node to the root of the tree and partly rebalances it.
     37 *
     38 * This has the benefit that request locality causes faster lookups as
     39 * the requested nodes move to the top of the tree.  On the other hand,
     40 * every lookup causes memory writes.
     41 *
     42 * The Balance Theorem bounds the total access time for m operations
     43 * and n inserts on an initially empty tree as O((m + n)lg n).  The
     44 * amortized cost for a sequence of m accesses to a splay tree is O(lg n);
     45 *
     46 * A red-black tree is a binary search tree with the node color as an
     47 * extra attribute.  It fulfills a set of conditions:
     48 *	- every search path from the root to a leaf consists of the
     49 *	  same number of black nodes,
     50 *	- each red node (except for the root) has a black parent,
     51 *	- each leaf node is black.
     52 *
     53 * Every operation on a red-black tree is bounded as O(lg n).
     54 * The maximum height of a red-black tree is 2lg (n+1).
     55 */
     56 
     57 #define SPLAY_HEAD(name, type)						\
     58 struct name {								\
     59 struct type *sph_root; /* root of the tree */			\
     60 }
     61 
     62 #define SPLAY_INITIALIZER(root)						\
     63 { NULL }
     64 
     65 #define SPLAY_INIT(root) do {						\
     66 (root)->sph_root = NULL;					\
     67 } while (0)
     68 
     69 #define SPLAY_ENTRY(type)						\
     70 struct {								\
     71 struct type *spe_left; /* left element */			\
     72 struct type *spe_right; /* right element */			\
     73 }
     74 
     75 #define SPLAY_LEFT(elm, field)		(elm)->field.spe_left
     76 #define SPLAY_RIGHT(elm, field)		(elm)->field.spe_right
     77 #define SPLAY_ROOT(head)		(head)->sph_root
     78 #define SPLAY_EMPTY(head)		(SPLAY_ROOT(head) == NULL)
     79 
     80 /* SPLAY_ROTATE_{LEFT,RIGHT} expect that tmp hold SPLAY_{RIGHT,LEFT} */
     81 #define SPLAY_ROTATE_RIGHT(head, tmp, field) do {			\
     82 SPLAY_LEFT((head)->sph_root, field) = SPLAY_RIGHT(tmp, field);	\
     83 SPLAY_RIGHT(tmp, field) = (head)->sph_root;			\
     84 (head)->sph_root = tmp;						\
     85 } while (0)
     86 
     87 #define SPLAY_ROTATE_LEFT(head, tmp, field) do {			\
     88 SPLAY_RIGHT((head)->sph_root, field) = SPLAY_LEFT(tmp, field);	\
     89 SPLAY_LEFT(tmp, field) = (head)->sph_root;			\
     90 (head)->sph_root = tmp;						\
     91 } while (0)
     92 
     93 #define SPLAY_LINKLEFT(head, tmp, field) do {				\
     94 SPLAY_LEFT(tmp, field) = (head)->sph_root;			\
     95 tmp = (head)->sph_root;						\
     96 (head)->sph_root = SPLAY_LEFT((head)->sph_root, field);		\
     97 } while (0)
     98 
     99 #define SPLAY_LINKRIGHT(head, tmp, field) do {				\
    100 SPLAY_RIGHT(tmp, field) = (head)->sph_root;			\
    101 tmp = (head)->sph_root;						\
    102 (head)->sph_root = SPLAY_RIGHT((head)->sph_root, field);	\
    103 } while (0)
    104 
    105 #define SPLAY_ASSEMBLE(head, node, left, right, field) do {		\
    106 SPLAY_RIGHT(left, field) = SPLAY_LEFT((head)->sph_root, field);	\
    107 SPLAY_LEFT(right, field) = SPLAY_RIGHT((head)->sph_root, field);\
    108 SPLAY_LEFT((head)->sph_root, field) = SPLAY_RIGHT(node, field);	\
    109 SPLAY_RIGHT((head)->sph_root, field) = SPLAY_LEFT(node, field);	\
    110 } while (0)
    111 
    112 /* Generates prototypes and inline functions */
    113 
    114 #define SPLAY_PROTOTYPE(name, type, field, cmp)				\
    115 void name##_SPLAY(struct name *, struct type *);			\
    116 void name##_SPLAY_MINMAX(struct name *, int);				\
    117 struct type *name##_SPLAY_INSERT(struct name *, struct type *);		\
    118 struct type *name##_SPLAY_REMOVE(struct name *, struct type *);		\
    119 								\
    120 /* Finds the node with the same key as elm */				\
    121 static __inline struct type *						\
    122 name##_SPLAY_FIND(struct name *head, struct type *elm)			\
    123 {									\
    124 if (SPLAY_EMPTY(head))						\
    125 	return(NULL);						\
    126 name##_SPLAY(head, elm);					\
    127 if ((cmp)(elm, (head)->sph_root) == 0)				\
    128 	return (head->sph_root);				\
    129 return (NULL);							\
    130 }									\
    131 								\
    132 static __inline struct type *						\
    133 name##_SPLAY_NEXT(struct name *head, struct type *elm)			\
    134 {									\
    135 name##_SPLAY(head, elm);					\
    136 if (SPLAY_RIGHT(elm, field) != NULL) {				\
    137 	elm = SPLAY_RIGHT(elm, field);				\
    138 	while (SPLAY_LEFT(elm, field) != NULL) {		\
    139 		elm = SPLAY_LEFT(elm, field);			\
    140 	}							\
    141 } else								\
    142 	elm = NULL;						\
    143 return (elm);							\
    144 }									\
    145 								\
    146 static __inline struct type *						\
    147 name##_SPLAY_MIN_MAX(struct name *head, int val)			\
    148 {									\
    149 name##_SPLAY_MINMAX(head, val);					\
    150 return (SPLAY_ROOT(head));					\
    151 }
    152 
    153 /* Main splay operation.
    154 * Moves node close to the key of elm to top
    155 */
    156 #define SPLAY_GENERATE(name, type, field, cmp)				\
    157 struct type *								\
    158 name##_SPLAY_INSERT(struct name *head, struct type *elm)		\
    159 {									\
    160    if (SPLAY_EMPTY(head)) {						\
    161     SPLAY_LEFT(elm, field) = SPLAY_RIGHT(elm, field) = NULL;	\
    162    } else {								\
    163     int __comp;							\
    164     name##_SPLAY(head, elm);					\
    165     __comp = (cmp)(elm, (head)->sph_root);			\
    166     if(__comp < 0) {						\
    167 	    SPLAY_LEFT(elm, field) = SPLAY_LEFT((head)->sph_root, field);\
    168 	    SPLAY_RIGHT(elm, field) = (head)->sph_root;		\
    169 	    SPLAY_LEFT((head)->sph_root, field) = NULL;		\
    170     } else if (__comp > 0) {					\
    171 	    SPLAY_RIGHT(elm, field) = SPLAY_RIGHT((head)->sph_root, field);\
    172 	    SPLAY_LEFT(elm, field) = (head)->sph_root;		\
    173 	    SPLAY_RIGHT((head)->sph_root, field) = NULL;	\
    174     } else							\
    175 	    return ((head)->sph_root);				\
    176    }									\
    177    (head)->sph_root = (elm);						\
    178    return (NULL);							\
    179 }									\
    180 								\
    181 struct type *								\
    182 name##_SPLAY_REMOVE(struct name *head, struct type *elm)		\
    183 {									\
    184 struct type *__tmp;						\
    185 if (SPLAY_EMPTY(head))						\
    186 	return (NULL);						\
    187 name##_SPLAY(head, elm);					\
    188 if ((cmp)(elm, (head)->sph_root) == 0) {			\
    189 	if (SPLAY_LEFT((head)->sph_root, field) == NULL) {	\
    190 		(head)->sph_root = SPLAY_RIGHT((head)->sph_root, field);\
    191 	} else {						\
    192 		__tmp = SPLAY_RIGHT((head)->sph_root, field);	\
    193 		(head)->sph_root = SPLAY_LEFT((head)->sph_root, field);\
    194 		name##_SPLAY(head, elm);			\
    195 		SPLAY_RIGHT((head)->sph_root, field) = __tmp;	\
    196 	}							\
    197 	return (elm);						\
    198 }								\
    199 return (NULL);							\
    200 }									\
    201 								\
    202 void									\
    203 name##_SPLAY(struct name *head, struct type *elm)			\
    204 {									\
    205 struct type __node, *__left, *__right, *__tmp;			\
    206 int __comp;							\
    207 \
    208 SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = NULL;\
    209 __left = __right = &__node;					\
    210 \
    211 while ((__comp = (cmp)(elm, (head)->sph_root))) {		\
    212 	if (__comp < 0) {					\
    213 		__tmp = SPLAY_LEFT((head)->sph_root, field);	\
    214 		if (__tmp == NULL)				\
    215 			break;					\
    216 		if ((cmp)(elm, __tmp) < 0){			\
    217 			SPLAY_ROTATE_RIGHT(head, __tmp, field);	\
    218 			if (SPLAY_LEFT((head)->sph_root, field) == NULL)\
    219 				break;				\
    220 		}						\
    221 		SPLAY_LINKLEFT(head, __right, field);		\
    222 	} else if (__comp > 0) {				\
    223 		__tmp = SPLAY_RIGHT((head)->sph_root, field);	\
    224 		if (__tmp == NULL)				\
    225 			break;					\
    226 		if ((cmp)(elm, __tmp) > 0){			\
    227 			SPLAY_ROTATE_LEFT(head, __tmp, field);	\
    228 			if (SPLAY_RIGHT((head)->sph_root, field) == NULL)\
    229 				break;				\
    230 		}						\
    231 		SPLAY_LINKRIGHT(head, __left, field);		\
    232 	}							\
    233 }								\
    234 SPLAY_ASSEMBLE(head, &__node, __left, __right, field);		\
    235 }									\
    236 								\
    237 /* Splay with either the minimum or the maximum element			\
    238 * Used to find minimum or maximum element in tree.			\
    239 */									\
    240 void name##_SPLAY_MINMAX(struct name *head, int __comp) \
    241 {									\
    242 struct type __node, *__left, *__right, *__tmp;			\
    243 \
    244 SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = NULL;\
    245 __left = __right = &__node;					\
    246 \
    247 while (1) {							\
    248 	if (__comp < 0) {					\
    249 		__tmp = SPLAY_LEFT((head)->sph_root, field);	\
    250 		if (__tmp == NULL)				\
    251 			break;					\
    252 		if (__comp < 0){				\
    253 			SPLAY_ROTATE_RIGHT(head, __tmp, field);	\
    254 			if (SPLAY_LEFT((head)->sph_root, field) == NULL)\
    255 				break;				\
    256 		}						\
    257 		SPLAY_LINKLEFT(head, __right, field);		\
    258 	} else if (__comp > 0) {				\
    259 		__tmp = SPLAY_RIGHT((head)->sph_root, field);	\
    260 		if (__tmp == NULL)				\
    261 			break;					\
    262 		if (__comp > 0) {				\
    263 			SPLAY_ROTATE_LEFT(head, __tmp, field);	\
    264 			if (SPLAY_RIGHT((head)->sph_root, field) == NULL)\
    265 				break;				\
    266 		}						\
    267 		SPLAY_LINKRIGHT(head, __left, field);		\
    268 	}							\
    269 }								\
    270 SPLAY_ASSEMBLE(head, &__node, __left, __right, field);		\
    271 }
    272 
    273 #define SPLAY_NEGINF	-1
    274 #define SPLAY_INF	1
    275 
    276 #define SPLAY_INSERT(name, x, y)	name##_SPLAY_INSERT(x, y)
    277 #define SPLAY_REMOVE(name, x, y)	name##_SPLAY_REMOVE(x, y)
    278 #define SPLAY_FIND(name, x, y)		name##_SPLAY_FIND(x, y)
    279 #define SPLAY_NEXT(name, x, y)		name##_SPLAY_NEXT(x, y)
    280 #define SPLAY_MIN(name, x)		(SPLAY_EMPTY(x) ? NULL	\
    281 				: name##_SPLAY_MIN_MAX(x, SPLAY_NEGINF))
    282 #define SPLAY_MAX(name, x)		(SPLAY_EMPTY(x) ? NULL	\
    283 				: name##_SPLAY_MIN_MAX(x, SPLAY_INF))
    284 
    285 #define SPLAY_FOREACH(x, name, head)					\
    286 for ((x) = SPLAY_MIN(name, head);				\
    287      (x) != NULL;						\
    288      (x) = SPLAY_NEXT(name, head, x))
    289 
    290 /* Macros that define a red-back tree */
    291 #define RB_HEAD(name, type)						\
    292 struct name {								\
    293 struct type *rbh_root; /* root of the tree */			\
    294 }
    295 
    296 #define RB_INITIALIZER(root)						\
    297 { NULL }
    298 
    299 #define RB_INIT(root) do {						\
    300 (root)->rbh_root = NULL;					\
    301 } while (0)
    302 
    303 #define RB_BLACK	0
    304 #define RB_RED		1
    305 #define RB_ENTRY(type)							\
    306 struct {								\
    307 struct type *rbe_left;		/* left element */		\
    308 struct type *rbe_right;		/* right element */		\
    309 struct type *rbe_parent;	/* parent element */		\
    310 int rbe_color;			/* node color */		\
    311 }
    312 
    313 #define RB_LEFT(elm, field)		(elm)->field.rbe_left
    314 #define RB_RIGHT(elm, field)		(elm)->field.rbe_right
    315 #define RB_PARENT(elm, field)		(elm)->field.rbe_parent
    316 #define RB_COLOR(elm, field)		(elm)->field.rbe_color
    317 #define RB_ROOT(head)			(head)->rbh_root
    318 #define RB_EMPTY(head)			(RB_ROOT(head) == NULL)
    319 
    320 #define RB_SET(elm, parent, field) do {					\
    321 RB_PARENT(elm, field) = parent;					\
    322 RB_LEFT(elm, field) = RB_RIGHT(elm, field) = NULL;		\
    323 RB_COLOR(elm, field) = RB_RED;					\
    324 } while (0)
    325 
    326 #define RB_SET_BLACKRED(black, red, field) do {				\
    327 RB_COLOR(black, field) = RB_BLACK;				\
    328 RB_COLOR(red, field) = RB_RED;					\
    329 } while (0)
    330 
    331 #ifndef RB_AUGMENT
    332 #define RB_AUGMENT(x)
    333 #endif
    334 
    335 #define RB_ROTATE_LEFT(head, elm, tmp, field) do {			\
    336 (tmp) = RB_RIGHT(elm, field);					\
    337 if ((RB_RIGHT(elm, field) = RB_LEFT(tmp, field))) {		\
    338 	RB_PARENT(RB_LEFT(tmp, field), field) = (elm);		\
    339 }								\
    340 RB_AUGMENT(elm);						\
    341 if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field))) {		\
    342 	if ((elm) == RB_LEFT(RB_PARENT(elm, field), field))	\
    343 		RB_LEFT(RB_PARENT(elm, field), field) = (tmp);	\
    344 	else							\
    345 		RB_RIGHT(RB_PARENT(elm, field), field) = (tmp);	\
    346 } else								\
    347 	(head)->rbh_root = (tmp);				\
    348 RB_LEFT(tmp, field) = (elm);					\
    349 RB_PARENT(elm, field) = (tmp);					\
    350 RB_AUGMENT(tmp);						\
    351 if ((RB_PARENT(tmp, field)))					\
    352 	RB_AUGMENT(RB_PARENT(tmp, field));			\
    353 } while (0)
    354 
    355 #define RB_ROTATE_RIGHT(head, elm, tmp, field) do {			\
    356 (tmp) = RB_LEFT(elm, field);					\
    357 if ((RB_LEFT(elm, field) = RB_RIGHT(tmp, field))) {		\
    358 	RB_PARENT(RB_RIGHT(tmp, field), field) = (elm);		\
    359 }								\
    360 RB_AUGMENT(elm);						\
    361 if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field))) {		\
    362 	if ((elm) == RB_LEFT(RB_PARENT(elm, field), field))	\
    363 		RB_LEFT(RB_PARENT(elm, field), field) = (tmp);	\
    364 	else							\
    365 		RB_RIGHT(RB_PARENT(elm, field), field) = (tmp);	\
    366 } else								\
    367 	(head)->rbh_root = (tmp);				\
    368 RB_RIGHT(tmp, field) = (elm);					\
    369 RB_PARENT(elm, field) = (tmp);					\
    370 RB_AUGMENT(tmp);						\
    371 if ((RB_PARENT(tmp, field)))					\
    372 	RB_AUGMENT(RB_PARENT(tmp, field));			\
    373 } while (0)
    374 
    375 /* Generates prototypes and inline functions */
    376 #define RB_PROTOTYPE(name, type, field, cmp)				\
    377 void name##_RB_INSERT_COLOR(struct name *, struct type *);	\
    378 void name##_RB_REMOVE_COLOR(struct name *, struct type *, struct type *);\
    379 struct type *name##_RB_REMOVE(struct name *, struct type *);		\
    380 struct type *name##_RB_INSERT(struct name *, struct type *);		\
    381 struct type *name##_RB_FIND(struct name *, struct type *);		\
    382 struct type *name##_RB_NEXT(struct type *);				\
    383 struct type *name##_RB_MINMAX(struct name *, int);			\
    384 								\
    385 
    386 /* Main rb operation.
    387 * Moves node close to the key of elm to top
    388 */
    389 #define RB_GENERATE(name, type, field, cmp)				\
    390 void									\
    391 name##_RB_INSERT_COLOR(struct name *head, struct type *elm)		\
    392 {									\
    393 struct type *parent, *gparent, *tmp;				\
    394 while ((parent = RB_PARENT(elm, field)) &&			\
    395     RB_COLOR(parent, field) == RB_RED) {			\
    396 	gparent = RB_PARENT(parent, field);			\
    397 	if (parent == RB_LEFT(gparent, field)) {		\
    398 		tmp = RB_RIGHT(gparent, field);			\
    399 		if (tmp && RB_COLOR(tmp, field) == RB_RED) {	\
    400 			RB_COLOR(tmp, field) = RB_BLACK;	\
    401 			RB_SET_BLACKRED(parent, gparent, field);\
    402 			elm = gparent;				\
    403 			continue;				\
    404 		}						\
    405 		if (RB_RIGHT(parent, field) == elm) {		\
    406 			RB_ROTATE_LEFT(head, parent, tmp, field);\
    407 			tmp = parent;				\
    408 			parent = elm;				\
    409 			elm = tmp;				\
    410 		}						\
    411 		RB_SET_BLACKRED(parent, gparent, field);	\
    412 		RB_ROTATE_RIGHT(head, gparent, tmp, field);	\
    413 	} else {						\
    414 		tmp = RB_LEFT(gparent, field);			\
    415 		if (tmp && RB_COLOR(tmp, field) == RB_RED) {	\
    416 			RB_COLOR(tmp, field) = RB_BLACK;	\
    417 			RB_SET_BLACKRED(parent, gparent, field);\
    418 			elm = gparent;				\
    419 			continue;				\
    420 		}						\
    421 		if (RB_LEFT(parent, field) == elm) {		\
    422 			RB_ROTATE_RIGHT(head, parent, tmp, field);\
    423 			tmp = parent;				\
    424 			parent = elm;				\
    425 			elm = tmp;				\
    426 		}						\
    427 		RB_SET_BLACKRED(parent, gparent, field);	\
    428 		RB_ROTATE_LEFT(head, gparent, tmp, field);	\
    429 	}							\
    430 }								\
    431 RB_COLOR(head->rbh_root, field) = RB_BLACK;			\
    432 }									\
    433 								\
    434 void									\
    435 name##_RB_REMOVE_COLOR(struct name *head, struct type *parent, struct type *elm) \
    436 {									\
    437 struct type *tmp;						\
    438 while ((elm == NULL || RB_COLOR(elm, field) == RB_BLACK) &&	\
    439     elm != RB_ROOT(head)) {					\
    440 	if (RB_LEFT(parent, field) == elm) {			\
    441 		tmp = RB_RIGHT(parent, field);			\
    442 		if (RB_COLOR(tmp, field) == RB_RED) {		\
    443 			RB_SET_BLACKRED(tmp, parent, field);	\
    444 			RB_ROTATE_LEFT(head, parent, tmp, field);\
    445 			tmp = RB_RIGHT(parent, field);		\
    446 		}						\
    447 		if ((RB_LEFT(tmp, field) == NULL ||		\
    448 		    RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
    449 		    (RB_RIGHT(tmp, field) == NULL ||		\
    450 		    RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
    451 			RB_COLOR(tmp, field) = RB_RED;		\
    452 			elm = parent;				\
    453 			parent = RB_PARENT(elm, field);		\
    454 		} else {					\
    455 			if (RB_RIGHT(tmp, field) == NULL ||	\
    456 			    RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK) {\
    457 				struct type *oleft;		\
    458 				if ((oleft = RB_LEFT(tmp, field)))\
    459 					RB_COLOR(oleft, field) = RB_BLACK;\
    460 				RB_COLOR(tmp, field) = RB_RED;	\
    461 				RB_ROTATE_RIGHT(head, tmp, oleft, field);\
    462 				tmp = RB_RIGHT(parent, field);	\
    463 			}					\
    464 			RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
    465 			RB_COLOR(parent, field) = RB_BLACK;	\
    466 			if (RB_RIGHT(tmp, field))		\
    467 				RB_COLOR(RB_RIGHT(tmp, field), field) = RB_BLACK;\
    468 			RB_ROTATE_LEFT(head, parent, tmp, field);\
    469 			elm = RB_ROOT(head);			\
    470 			break;					\
    471 		}						\
    472 	} else {						\
    473 		tmp = RB_LEFT(parent, field);			\
    474 		if (RB_COLOR(tmp, field) == RB_RED) {		\
    475 			RB_SET_BLACKRED(tmp, parent, field);	\
    476 			RB_ROTATE_RIGHT(head, parent, tmp, field);\
    477 			tmp = RB_LEFT(parent, field);		\
    478 		}						\
    479 		if ((RB_LEFT(tmp, field) == NULL ||		\
    480 		    RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
    481 		    (RB_RIGHT(tmp, field) == NULL ||		\
    482 		    RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
    483 			RB_COLOR(tmp, field) = RB_RED;		\
    484 			elm = parent;				\
    485 			parent = RB_PARENT(elm, field);		\
    486 		} else {					\
    487 			if (RB_LEFT(tmp, field) == NULL ||	\
    488 			    RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) {\
    489 				struct type *oright;		\
    490 				if ((oright = RB_RIGHT(tmp, field)))\
    491 					RB_COLOR(oright, field) = RB_BLACK;\
    492 				RB_COLOR(tmp, field) = RB_RED;	\
    493 				RB_ROTATE_LEFT(head, tmp, oright, field);\
    494 				tmp = RB_LEFT(parent, field);	\
    495 			}					\
    496 			RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
    497 			RB_COLOR(parent, field) = RB_BLACK;	\
    498 			if (RB_LEFT(tmp, field))		\
    499 				RB_COLOR(RB_LEFT(tmp, field), field) = RB_BLACK;\
    500 			RB_ROTATE_RIGHT(head, parent, tmp, field);\
    501 			elm = RB_ROOT(head);			\
    502 			break;					\
    503 		}						\
    504 	}							\
    505 }								\
    506 if (elm)							\
    507 	RB_COLOR(elm, field) = RB_BLACK;			\
    508 }									\
    509 								\
    510 struct type *								\
    511 name##_RB_REMOVE(struct name *head, struct type *elm)			\
    512 {									\
    513 struct type *child, *parent, *old = elm;			\
    514 int color;							\
    515 if (RB_LEFT(elm, field) == NULL)				\
    516 	child = RB_RIGHT(elm, field);				\
    517 else if (RB_RIGHT(elm, field) == NULL)				\
    518 	child = RB_LEFT(elm, field);				\
    519 else {								\
    520 	struct type *left;					\
    521 	elm = RB_RIGHT(elm, field);				\
    522 	while ((left = RB_LEFT(elm, field)))			\
    523 		elm = left;					\
    524 	child = RB_RIGHT(elm, field);				\
    525 	parent = RB_PARENT(elm, field);				\
    526 	color = RB_COLOR(elm, field);				\
    527 	if (child)						\
    528 		RB_PARENT(child, field) = parent;		\
    529 	if (parent) {						\
    530 		if (RB_LEFT(parent, field) == elm)		\
    531 			RB_LEFT(parent, field) = child;		\
    532 		else						\
    533 			RB_RIGHT(parent, field) = child;	\
    534 		RB_AUGMENT(parent);				\
    535 	} else							\
    536 		RB_ROOT(head) = child;				\
    537 	if (RB_PARENT(elm, field) == old)			\
    538 		parent = elm;					\
    539 	(elm)->field = (old)->field;				\
    540 	if (RB_PARENT(old, field)) {				\
    541 		if (RB_LEFT(RB_PARENT(old, field), field) == old)\
    542 			RB_LEFT(RB_PARENT(old, field), field) = elm;\
    543 		else						\
    544 			RB_RIGHT(RB_PARENT(old, field), field) = elm;\
    545 		RB_AUGMENT(RB_PARENT(old, field));		\
    546 	} else							\
    547 		RB_ROOT(head) = elm;				\
    548 	RB_PARENT(RB_LEFT(old, field), field) = elm;		\
    549 	if (RB_RIGHT(old, field))				\
    550 		RB_PARENT(RB_RIGHT(old, field), field) = elm;	\
    551 	if (parent) {						\
    552 		left = parent;					\
    553 		do {						\
    554 			RB_AUGMENT(left);			\
    555 		} while ((left = RB_PARENT(left, field)));	\
    556 	}							\
    557 	goto color;						\
    558 }								\
    559 parent = RB_PARENT(elm, field);					\
    560 color = RB_COLOR(elm, field);					\
    561 if (child)							\
    562 	RB_PARENT(child, field) = parent;			\
    563 if (parent) {							\
    564 	if (RB_LEFT(parent, field) == elm)			\
    565 		RB_LEFT(parent, field) = child;			\
    566 	else							\
    567 		RB_RIGHT(parent, field) = child;		\
    568 	RB_AUGMENT(parent);					\
    569 } else								\
    570 	RB_ROOT(head) = child;					\
    571 color:									\
    572 if (color == RB_BLACK)						\
    573 	name##_RB_REMOVE_COLOR(head, parent, child);		\
    574 return (old);							\
    575 }									\
    576 								\
    577 /* Inserts a node into the RB tree */					\
    578 struct type *								\
    579 name##_RB_INSERT(struct name *head, struct type *elm)			\
    580 {									\
    581 struct type *tmp;						\
    582 struct type *parent = NULL;					\
    583 int comp = 0;							\
    584 tmp = RB_ROOT(head);						\
    585 while (tmp) {							\
    586 	parent = tmp;						\
    587 	comp = (cmp)(elm, parent);				\
    588 	if (comp < 0)						\
    589 		tmp = RB_LEFT(tmp, field);			\
    590 	else if (comp > 0)					\
    591 		tmp = RB_RIGHT(tmp, field);			\
    592 	else							\
    593 		return (tmp);					\
    594 }								\
    595 RB_SET(elm, parent, field);					\
    596 if (parent != NULL) {						\
    597 	if (comp < 0)						\
    598 		RB_LEFT(parent, field) = elm;			\
    599 	else							\
    600 		RB_RIGHT(parent, field) = elm;			\
    601 	RB_AUGMENT(parent);					\
    602 } else								\
    603 	RB_ROOT(head) = elm;					\
    604 name##_RB_INSERT_COLOR(head, elm);				\
    605 return (NULL);							\
    606 }									\
    607 								\
    608 /* Finds the node with the same key as elm */				\
    609 struct type *								\
    610 name##_RB_FIND(struct name *head, struct type *elm)			\
    611 {									\
    612 struct type *tmp = RB_ROOT(head);				\
    613 int comp;							\
    614 while (tmp) {							\
    615 	comp = cmp(elm, tmp);					\
    616 	if (comp < 0)						\
    617 		tmp = RB_LEFT(tmp, field);			\
    618 	else if (comp > 0)					\
    619 		tmp = RB_RIGHT(tmp, field);			\
    620 	else							\
    621 		return (tmp);					\
    622 }								\
    623 return (NULL);							\
    624 }									\
    625 								\
    626 struct type *								\
    627 name##_RB_NEXT(struct type *elm)					\
    628 {									\
    629 if (RB_RIGHT(elm, field)) {					\
    630 	elm = RB_RIGHT(elm, field);				\
    631 	while (RB_LEFT(elm, field))				\
    632 		elm = RB_LEFT(elm, field);			\
    633 } else {							\
    634 	if (RB_PARENT(elm, field) &&				\
    635 	    (elm == RB_LEFT(RB_PARENT(elm, field), field)))	\
    636 		elm = RB_PARENT(elm, field);			\
    637 	else {							\
    638 		while (RB_PARENT(elm, field) &&			\
    639 		    (elm == RB_RIGHT(RB_PARENT(elm, field), field)))\
    640 			elm = RB_PARENT(elm, field);		\
    641 		elm = RB_PARENT(elm, field);			\
    642 	}							\
    643 }								\
    644 return (elm);							\
    645 }									\
    646 								\
    647 struct type *								\
    648 name##_RB_MINMAX(struct name *head, int val)				\
    649 {									\
    650 struct type *tmp = RB_ROOT(head);				\
    651 struct type *parent = NULL;					\
    652 while (tmp) {							\
    653 	parent = tmp;						\
    654 	if (val < 0)						\
    655 		tmp = RB_LEFT(tmp, field);			\
    656 	else							\
    657 		tmp = RB_RIGHT(tmp, field);			\
    658 }								\
    659 return (parent);						\
    660 }
    661 
    662 #define RB_NEGINF	-1
    663 #define RB_INF	1
    664 
    665 #define RB_INSERT(name, x, y)	name##_RB_INSERT(x, y)
    666 #define RB_REMOVE(name, x, y)	name##_RB_REMOVE(x, y)
    667 #define RB_FIND(name, x, y)	name##_RB_FIND(x, y)
    668 #define RB_NEXT(name, x, y)	name##_RB_NEXT(y)
    669 #define RB_MIN(name, x)		name##_RB_MINMAX(x, RB_NEGINF)
    670 #define RB_MAX(name, x)		name##_RB_MINMAX(x, RB_INF)
    671 
    672 #define RB_FOREACH(x, name, head)					\
    673 for ((x) = RB_MIN(name, head);					\
    674      (x) != NULL;						\
    675      (x) = name##_RB_NEXT(x))
    676 
    677 #endif	/* _SYS_TREE_H_ */