1/*	$NetBSD: tree.h,v 1.20 2013/09/14 13:20:45 joerg Exp $	*/
  2/*	$OpenBSD: tree.h,v 1.13 2011/07/09 00:19:45 pirofti Exp $	*/
  3/*
  4 * Copyright 2002 Niels Provos <provos@citi.umich.edu>
  5 * All rights reserved.
  6 *
  7 * Redistribution and use in source and binary forms, with or without
  8 * modification, are permitted provided that the following conditions
  9 * are met:
 10 * 1. Redistributions of source code must retain the above copyright
 11 *    notice, this list of conditions and the following disclaimer.
 12 * 2. Redistributions in binary form must reproduce the above copyright
 13 *    notice, this list of conditions and the following disclaimer in the
 14 *    documentation and/or other materials provided with the distribution.
 15 *
 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 26 */
 27
 28#ifndef	_SYS_TREE_H_
 29#define	_SYS_TREE_H_
 30
 31/*
 32 * This file defines data structures for different types of trees:
 33 * splay trees and red-black trees.
 34 *
 35 * A splay tree is a self-organizing data structure.  Every operation
 36 * on the tree causes a splay to happen.  The splay moves the requested
 37 * node to the root of the tree and partly rebalances it.
 38 *
 39 * This has the benefit that request locality causes faster lookups as
 40 * the requested nodes move to the top of the tree.  On the other hand,
 41 * every lookup causes memory writes.
 42 *
 43 * The Balance Theorem bounds the total access time for m operations
 44 * and n inserts on an initially empty tree as O((m + n)lg n).  The
 45 * amortized cost for a sequence of m accesses to a splay tree is O(lg n);
 46 *
 47 * A red-black tree is a binary search tree with the node color as an
 48 * extra attribute.  It fulfills a set of conditions:
 49 *	- every search path from the root to a leaf consists of the
 50 *	  same number of black nodes,
 51 *	- each red node (except for the root) has a black parent,
 52 *	- each leaf node is black.
 53 *
 54 * Every operation on a red-black tree is bounded as O(lg n).
 55 * The maximum height of a red-black tree is 2lg (n+1).
 56 */
 57
 58#define SPLAY_HEAD(name, type)						\
 59struct name {								\
 60	struct type *sph_root; /* root of the tree */			\
 61}
 62
 63#define SPLAY_INITIALIZER(root)						\
 64	{ NULL }
 65
 66#define SPLAY_INIT(root) do {						\
 67	(root)->sph_root = NULL;					\
 68} while (/*CONSTCOND*/ 0)
 69
 70#define SPLAY_ENTRY(type)						\
 71struct {								\
 72	struct type *spe_left; /* left element */			\
 73	struct type *spe_right; /* right element */			\
 74}
 75
 76#define SPLAY_LEFT(elm, field)		(elm)->field.spe_left
 77#define SPLAY_RIGHT(elm, field)		(elm)->field.spe_right
 78#define SPLAY_ROOT(head)		(head)->sph_root
 79#define SPLAY_EMPTY(head)		(SPLAY_ROOT(head) == NULL)
 80
 81/* SPLAY_ROTATE_{LEFT,RIGHT} expect that tmp hold SPLAY_{RIGHT,LEFT} */
 82#define SPLAY_ROTATE_RIGHT(head, tmp, field) do {			\
 83	SPLAY_LEFT((head)->sph_root, field) = SPLAY_RIGHT(tmp, field);	\
 84	SPLAY_RIGHT(tmp, field) = (head)->sph_root;			\
 85	(head)->sph_root = tmp;						\
 86} while (/*CONSTCOND*/ 0)
 87
 88#define SPLAY_ROTATE_LEFT(head, tmp, field) do {			\
 89	SPLAY_RIGHT((head)->sph_root, field) = SPLAY_LEFT(tmp, field);	\
 90	SPLAY_LEFT(tmp, field) = (head)->sph_root;			\
 91	(head)->sph_root = tmp;						\
 92} while (/*CONSTCOND*/ 0)
 93
 94#define SPLAY_LINKLEFT(head, tmp, field) do {				\
 95	SPLAY_LEFT(tmp, field) = (head)->sph_root;			\
 96	tmp = (head)->sph_root;						\
 97	(head)->sph_root = SPLAY_LEFT((head)->sph_root, field);		\
 98} while (/*CONSTCOND*/ 0)
 99
100#define SPLAY_LINKRIGHT(head, tmp, field) do {				\
101	SPLAY_RIGHT(tmp, field) = (head)->sph_root;			\
102	tmp = (head)->sph_root;						\
103	(head)->sph_root = SPLAY_RIGHT((head)->sph_root, field);	\
104} while (/*CONSTCOND*/ 0)
105
106#define SPLAY_ASSEMBLE(head, node, left, right, field) do {		\
107	SPLAY_RIGHT(left, field) = SPLAY_LEFT((head)->sph_root, field);	\
108	SPLAY_LEFT(right, field) = SPLAY_RIGHT((head)->sph_root, field);\
109	SPLAY_LEFT((head)->sph_root, field) = SPLAY_RIGHT(node, field);	\
110	SPLAY_RIGHT((head)->sph_root, field) = SPLAY_LEFT(node, field);	\
111} while (/*CONSTCOND*/ 0)
112
113/* Generates prototypes and inline functions */
114
115#define SPLAY_PROTOTYPE(name, type, field, cmp)				\
116void name##_SPLAY(struct name *, struct type *);			\
117void name##_SPLAY_MINMAX(struct name *, int);				\
118struct type *name##_SPLAY_INSERT(struct name *, struct type *);		\
119struct type *name##_SPLAY_REMOVE(struct name *, struct type *);		\
120									\
121/* Finds the node with the same key as elm */				\
122static __inline struct type *						\
123name##_SPLAY_FIND(struct name *head, struct type *elm)			\
124{									\
125	if (SPLAY_EMPTY(head))						\
126		return(NULL);						\
127	name##_SPLAY(head, elm);					\
128	if ((cmp)(elm, (head)->sph_root) == 0)				\
129		return (head->sph_root);				\
130	return (NULL);							\
131}									\
132									\
133static __inline __unused struct type *					\
134name##_SPLAY_NEXT(struct name *head, struct type *elm)			\
135{									\
136	name##_SPLAY(head, elm);					\
137	if (SPLAY_RIGHT(elm, field) != NULL) {				\
138		elm = SPLAY_RIGHT(elm, field);				\
139		while (SPLAY_LEFT(elm, field) != NULL) {		\
140			elm = SPLAY_LEFT(elm, field);			\
141		}							\
142	} else								\
143		elm = NULL;						\
144	return (elm);							\
145}									\
146									\
147static __unused __inline struct type *					\
148name##_SPLAY_MIN_MAX(struct name *head, int val)			\
149{									\
150	name##_SPLAY_MINMAX(head, val);					\
151        return (SPLAY_ROOT(head));					\
152}
153
154/* Main splay operation.
155 * Moves node close to the key of elm to top
156 */
157#define SPLAY_GENERATE(name, type, field, cmp)				\
158struct type *								\
159name##_SPLAY_INSERT(struct name *head, struct type *elm)		\
160{									\
161    if (SPLAY_EMPTY(head)) {						\
162	    SPLAY_LEFT(elm, field) = SPLAY_RIGHT(elm, field) = NULL;	\
163    } else {								\
164	    int __comp;							\
165	    name##_SPLAY(head, elm);					\
166	    __comp = (cmp)(elm, (head)->sph_root);			\
167	    if(__comp < 0) {						\
168		    SPLAY_LEFT(elm, field) = SPLAY_LEFT((head)->sph_root, field);\
169		    SPLAY_RIGHT(elm, field) = (head)->sph_root;		\
170		    SPLAY_LEFT((head)->sph_root, field) = NULL;		\
171	    } else if (__comp > 0) {					\
172		    SPLAY_RIGHT(elm, field) = SPLAY_RIGHT((head)->sph_root, field);\
173		    SPLAY_LEFT(elm, field) = (head)->sph_root;		\
174		    SPLAY_RIGHT((head)->sph_root, field) = NULL;	\
175	    } else							\
176		    return ((head)->sph_root);				\
177    }									\
178    (head)->sph_root = (elm);						\
179    return (NULL);							\
180}									\
181									\
182struct type *								\
183name##_SPLAY_REMOVE(struct name *head, struct type *elm)		\
184{									\
185	struct type *__tmp;						\
186	if (SPLAY_EMPTY(head))						\
187		return (NULL);						\
188	name##_SPLAY(head, elm);					\
189	if ((cmp)(elm, (head)->sph_root) == 0) {			\
190		if (SPLAY_LEFT((head)->sph_root, field) == NULL) {	\
191			(head)->sph_root = SPLAY_RIGHT((head)->sph_root, field);\
192		} else {						\
193			__tmp = SPLAY_RIGHT((head)->sph_root, field);	\
194			(head)->sph_root = SPLAY_LEFT((head)->sph_root, field);\
195			name##_SPLAY(head, elm);			\
196			SPLAY_RIGHT((head)->sph_root, field) = __tmp;	\
197		}							\
198		return (elm);						\
199	}								\
200	return (NULL);							\
201}									\
202									\
203void									\
204name##_SPLAY(struct name *head, struct type *elm)			\
205{									\
206	struct type __node, *__left, *__right, *__tmp;			\
207	int __comp;							\
208\
209	SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = NULL;\
210	__left = __right = &__node;					\
211\
212	while ((__comp = (cmp)(elm, (head)->sph_root)) != 0) {		\
213		if (__comp < 0) {					\
214			__tmp = SPLAY_LEFT((head)->sph_root, field);	\
215			if (__tmp == NULL)				\
216				break;					\
217			if ((cmp)(elm, __tmp) < 0){			\
218				SPLAY_ROTATE_RIGHT(head, __tmp, field);	\
219				if (SPLAY_LEFT((head)->sph_root, field) == NULL)\
220					break;				\
221			}						\
222			SPLAY_LINKLEFT(head, __right, field);		\
223		} else if (__comp > 0) {				\
224			__tmp = SPLAY_RIGHT((head)->sph_root, field);	\
225			if (__tmp == NULL)				\
226				break;					\
227			if ((cmp)(elm, __tmp) > 0){			\
228				SPLAY_ROTATE_LEFT(head, __tmp, field);	\
229				if (SPLAY_RIGHT((head)->sph_root, field) == NULL)\
230					break;				\
231			}						\
232			SPLAY_LINKRIGHT(head, __left, field);		\
233		}							\
234	}								\
235	SPLAY_ASSEMBLE(head, &__node, __left, __right, field);		\
236}									\
237									\
238/* Splay with either the minimum or the maximum element			\
239 * Used to find minimum or maximum element in tree.			\
240 */									\
241void name##_SPLAY_MINMAX(struct name *head, int __comp) \
242{									\
243	struct type __node, *__left, *__right, *__tmp;			\
244\
245	SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = NULL;\
246	__left = __right = &__node;					\
247\
248	while (1) {							\
249		if (__comp < 0) {					\
250			__tmp = SPLAY_LEFT((head)->sph_root, field);	\
251			if (__tmp == NULL)				\
252				break;					\
253			if (__comp < 0){				\
254				SPLAY_ROTATE_RIGHT(head, __tmp, field);	\
255				if (SPLAY_LEFT((head)->sph_root, field) == NULL)\
256					break;				\
257			}						\
258			SPLAY_LINKLEFT(head, __right, field);		\
259		} else if (__comp > 0) {				\
260			__tmp = SPLAY_RIGHT((head)->sph_root, field);	\
261			if (__tmp == NULL)				\
262				break;					\
263			if (__comp > 0) {				\
264				SPLAY_ROTATE_LEFT(head, __tmp, field);	\
265				if (SPLAY_RIGHT((head)->sph_root, field) == NULL)\
266					break;				\
267			}						\
268			SPLAY_LINKRIGHT(head, __left, field);		\
269		}							\
270	}								\
271	SPLAY_ASSEMBLE(head, &__node, __left, __right, field);		\
272}
273
274#define SPLAY_NEGINF	-1
275#define SPLAY_INF	1
276
277#define SPLAY_INSERT(name, x, y)	name##_SPLAY_INSERT(x, y)
278#define SPLAY_REMOVE(name, x, y)	name##_SPLAY_REMOVE(x, y)
279#define SPLAY_FIND(name, x, y)		name##_SPLAY_FIND(x, y)
280#define SPLAY_NEXT(name, x, y)		name##_SPLAY_NEXT(x, y)
281#define SPLAY_MIN(name, x)		(SPLAY_EMPTY(x) ? NULL	\
282					: name##_SPLAY_MIN_MAX(x, SPLAY_NEGINF))
283#define SPLAY_MAX(name, x)		(SPLAY_EMPTY(x) ? NULL	\
284					: name##_SPLAY_MIN_MAX(x, SPLAY_INF))
285
286#define SPLAY_FOREACH(x, name, head)					\
287	for ((x) = SPLAY_MIN(name, head);				\
288	     (x) != NULL;						\
289	     (x) = SPLAY_NEXT(name, head, x))
290
291/* Macros that define a red-black tree */
292#define RB_HEAD(name, type)						\
293struct name {								\
294	struct type *rbh_root; /* root of the tree */			\
295}
296
297#define RB_INITIALIZER(root)						\
298	{ NULL }
299
300#define RB_INIT(root) do {						\
301	(root)->rbh_root = NULL;					\
302} while (/*CONSTCOND*/ 0)
303
304#define RB_BLACK	0
305#define RB_RED		1
306#define RB_ENTRY(type)							\
307struct {								\
308	struct type *rbe_left;		/* left element */		\
309	struct type *rbe_right;		/* right element */		\
310	struct type *rbe_parent;	/* parent element */		\
311	int rbe_color;			/* node color */		\
312}
313
314#define RB_LEFT(elm, field)		(elm)->field.rbe_left
315#define RB_RIGHT(elm, field)		(elm)->field.rbe_right
316#define RB_PARENT(elm, field)		(elm)->field.rbe_parent
317#define RB_COLOR(elm, field)		(elm)->field.rbe_color
318#define RB_ROOT(head)			(head)->rbh_root
319#define RB_EMPTY(head)			(RB_ROOT(head) == NULL)
320
321#define RB_SET(elm, parent, field) do {					\
322	RB_PARENT(elm, field) = parent;					\
323	RB_LEFT(elm, field) = RB_RIGHT(elm, field) = NULL;		\
324	RB_COLOR(elm, field) = RB_RED;					\
325} while (/*CONSTCOND*/ 0)
326
327#define RB_SET_BLACKRED(black, red, field) do {				\
328	RB_COLOR(black, field) = RB_BLACK;				\
329	RB_COLOR(red, field) = RB_RED;					\
330} while (/*CONSTCOND*/ 0)
331
332#ifndef RB_AUGMENT
333#define RB_AUGMENT(x)	do {} while (/*CONSTCOND*/ 0)
334#endif
335
336#define RB_ROTATE_LEFT(head, elm, tmp, field) do {			\
337	(tmp) = RB_RIGHT(elm, field);					\
338	if ((RB_RIGHT(elm, field) = RB_LEFT(tmp, field)) != NULL) {	\
339		RB_PARENT(RB_LEFT(tmp, field), field) = (elm);		\
340	}								\
341	RB_AUGMENT(elm);						\
342	if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field)) != NULL) {	\
343		if ((elm) == RB_LEFT(RB_PARENT(elm, field), field))	\
344			RB_LEFT(RB_PARENT(elm, field), field) = (tmp);	\
345		else							\
346			RB_RIGHT(RB_PARENT(elm, field), field) = (tmp);	\
347	} else								\
348		(head)->rbh_root = (tmp);				\
349	RB_LEFT(tmp, field) = (elm);					\
350	RB_PARENT(elm, field) = (tmp);					\
351	RB_AUGMENT(tmp);						\
352	if ((RB_PARENT(tmp, field)))					\
353		RB_AUGMENT(RB_PARENT(tmp, field));			\
354} while (/*CONSTCOND*/ 0)
355
356#define RB_ROTATE_RIGHT(head, elm, tmp, field) do {			\
357	(tmp) = RB_LEFT(elm, field);					\
358	if ((RB_LEFT(elm, field) = RB_RIGHT(tmp, field)) != NULL) {	\
359		RB_PARENT(RB_RIGHT(tmp, field), field) = (elm);		\
360	}								\
361	RB_AUGMENT(elm);						\
362	if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field)) != NULL) {	\
363		if ((elm) == RB_LEFT(RB_PARENT(elm, field), field))	\
364			RB_LEFT(RB_PARENT(elm, field), field) = (tmp);	\
365		else							\
366			RB_RIGHT(RB_PARENT(elm, field), field) = (tmp);	\
367	} else								\
368		(head)->rbh_root = (tmp);				\
369	RB_RIGHT(tmp, field) = (elm);					\
370	RB_PARENT(elm, field) = (tmp);					\
371	RB_AUGMENT(tmp);						\
372	if ((RB_PARENT(tmp, field)))					\
373		RB_AUGMENT(RB_PARENT(tmp, field));			\
374} while (/*CONSTCOND*/ 0)
375
376/* Generates prototypes and inline functions */
377#define RB_PROTOTYPE(name, type, field, cmp)				\
378	RB_PROTOTYPE_INTERNAL(name, type, field, cmp,)
379#define	RB_PROTOTYPE_STATIC(name, type, field, cmp)			\
380	RB_PROTOTYPE_INTERNAL(name, type, field, cmp, __unused static)
381#define RB_PROTOTYPE_INTERNAL(name, type, field, cmp, attr)		\
382attr void name##_RB_INSERT_COLOR(struct name *, struct type *);		\
383attr void name##_RB_REMOVE_COLOR(struct name *, struct type *, struct type *);\
384attr struct type *name##_RB_REMOVE(struct name *, struct type *);	\
385attr struct type *name##_RB_INSERT(struct name *, struct type *);	\
386attr struct type *name##_RB_FIND(struct name *, struct type *);		\
387attr struct type *name##_RB_NFIND(struct name *, struct type *);	\
388attr struct type *name##_RB_NEXT(struct type *);			\
389attr struct type *name##_RB_PREV(struct type *);			\
390attr struct type *name##_RB_MINMAX(struct name *, int);			\
391									\
392
393/* Main rb operation.
394 * Moves node close to the key of elm to top
395 */
396#define	RB_GENERATE(name, type, field, cmp)				\
397	RB_GENERATE_INTERNAL(name, type, field, cmp,)
398#define	RB_GENERATE_STATIC(name, type, field, cmp)			\
399	RB_GENERATE_INTERNAL(name, type, field, cmp, __unused static)
400#define RB_GENERATE_INTERNAL(name, type, field, cmp, attr)		\
401attr void								\
402name##_RB_INSERT_COLOR(struct name *head, struct type *elm)		\
403{									\
404	struct type *parent, *gparent, *tmp;				\
405	while ((parent = RB_PARENT(elm, field)) != NULL &&		\
406	    RB_COLOR(parent, field) == RB_RED) {			\
407		gparent = RB_PARENT(parent, field);			\
408		if (parent == RB_LEFT(gparent, field)) {		\
409			tmp = RB_RIGHT(gparent, field);			\
410			if (tmp && RB_COLOR(tmp, field) == RB_RED) {	\
411				RB_COLOR(tmp, field) = RB_BLACK;	\
412				RB_SET_BLACKRED(parent, gparent, field);\
413				elm = gparent;				\
414				continue;				\
415			}						\
416			if (RB_RIGHT(parent, field) == elm) {		\
417				RB_ROTATE_LEFT(head, parent, tmp, field);\
418				tmp = parent;				\
419				parent = elm;				\
420				elm = tmp;				\
421			}						\
422			RB_SET_BLACKRED(parent, gparent, field);	\
423			RB_ROTATE_RIGHT(head, gparent, tmp, field);	\
424		} else {						\
425			tmp = RB_LEFT(gparent, field);			\
426			if (tmp && RB_COLOR(tmp, field) == RB_RED) {	\
427				RB_COLOR(tmp, field) = RB_BLACK;	\
428				RB_SET_BLACKRED(parent, gparent, field);\
429				elm = gparent;				\
430				continue;				\
431			}						\
432			if (RB_LEFT(parent, field) == elm) {		\
433				RB_ROTATE_RIGHT(head, parent, tmp, field);\
434				tmp = parent;				\
435				parent = elm;				\
436				elm = tmp;				\
437			}						\
438			RB_SET_BLACKRED(parent, gparent, field);	\
439			RB_ROTATE_LEFT(head, gparent, tmp, field);	\
440		}							\
441	}								\
442	RB_COLOR(head->rbh_root, field) = RB_BLACK;			\
443}									\
444									\
445attr void								\
446name##_RB_REMOVE_COLOR(struct name *head, struct type *parent, struct type *elm) \
447{									\
448	struct type *tmp;						\
449	while ((elm == NULL || RB_COLOR(elm, field) == RB_BLACK) &&	\
450	    elm != RB_ROOT(head)) {					\
451		if (RB_LEFT(parent, field) == elm) {			\
452			tmp = RB_RIGHT(parent, field);			\
453			if (RB_COLOR(tmp, field) == RB_RED) {		\
454				RB_SET_BLACKRED(tmp, parent, field);	\
455				RB_ROTATE_LEFT(head, parent, tmp, field);\
456				tmp = RB_RIGHT(parent, field);		\
457			}						\
458			if ((RB_LEFT(tmp, field) == NULL ||		\
459			    RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
460			    (RB_RIGHT(tmp, field) == NULL ||		\
461			    RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
462				RB_COLOR(tmp, field) = RB_RED;		\
463				elm = parent;				\
464				parent = RB_PARENT(elm, field);		\
465			} else {					\
466				if (RB_RIGHT(tmp, field) == NULL ||	\
467				    RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK) {\
468					struct type *oleft;		\
469					if ((oleft = RB_LEFT(tmp, field)) \
470					    != NULL)			\
471						RB_COLOR(oleft, field) = RB_BLACK;\
472					RB_COLOR(tmp, field) = RB_RED;	\
473					RB_ROTATE_RIGHT(head, tmp, oleft, field);\
474					tmp = RB_RIGHT(parent, field);	\
475				}					\
476				RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
477				RB_COLOR(parent, field) = RB_BLACK;	\
478				if (RB_RIGHT(tmp, field))		\
479					RB_COLOR(RB_RIGHT(tmp, field), field) = RB_BLACK;\
480				RB_ROTATE_LEFT(head, parent, tmp, field);\
481				elm = RB_ROOT(head);			\
482				break;					\
483			}						\
484		} else {						\
485			tmp = RB_LEFT(parent, field);			\
486			if (RB_COLOR(tmp, field) == RB_RED) {		\
487				RB_SET_BLACKRED(tmp, parent, field);	\
488				RB_ROTATE_RIGHT(head, parent, tmp, field);\
489				tmp = RB_LEFT(parent, field);		\
490			}						\
491			if ((RB_LEFT(tmp, field) == NULL ||		\
492			    RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
493			    (RB_RIGHT(tmp, field) == NULL ||		\
494			    RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
495				RB_COLOR(tmp, field) = RB_RED;		\
496				elm = parent;				\
497				parent = RB_PARENT(elm, field);		\
498			} else {					\
499				if (RB_LEFT(tmp, field) == NULL ||	\
500				    RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) {\
501					struct type *oright;		\
502					if ((oright = RB_RIGHT(tmp, field)) \
503					    != NULL)			\
504						RB_COLOR(oright, field) = RB_BLACK;\
505					RB_COLOR(tmp, field) = RB_RED;	\
506					RB_ROTATE_LEFT(head, tmp, oright, field);\
507					tmp = RB_LEFT(parent, field);	\
508				}					\
509				RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
510				RB_COLOR(parent, field) = RB_BLACK;	\
511				if (RB_LEFT(tmp, field))		\
512					RB_COLOR(RB_LEFT(tmp, field), field) = RB_BLACK;\
513				RB_ROTATE_RIGHT(head, parent, tmp, field);\
514				elm = RB_ROOT(head);			\
515				break;					\
516			}						\
517		}							\
518	}								\
519	if (elm)							\
520		RB_COLOR(elm, field) = RB_BLACK;			\
521}									\
522									\
523attr struct type *							\
524name##_RB_REMOVE(struct name *head, struct type *elm)			\
525{									\
526	struct type *child, *parent, *old = elm;			\
527	int color;							\
528	if (RB_LEFT(elm, field) == NULL)				\
529		child = RB_RIGHT(elm, field);				\
530	else if (RB_RIGHT(elm, field) == NULL)				\
531		child = RB_LEFT(elm, field);				\
532	else {								\
533		struct type *left;					\
534		elm = RB_RIGHT(elm, field);				\
535		while ((left = RB_LEFT(elm, field)) != NULL)		\
536			elm = left;					\
537		child = RB_RIGHT(elm, field);				\
538		parent = RB_PARENT(elm, field);				\
539		color = RB_COLOR(elm, field);				\
540		if (child)						\
541			RB_PARENT(child, field) = parent;		\
542		if (parent) {						\
543			if (RB_LEFT(parent, field) == elm)		\
544				RB_LEFT(parent, field) = child;		\
545			else						\
546				RB_RIGHT(parent, field) = child;	\
547			RB_AUGMENT(parent);				\
548		} else							\
549			RB_ROOT(head) = child;				\
550		if (RB_PARENT(elm, field) == old)			\
551			parent = elm;					\
552		(elm)->field = (old)->field;				\
553		if (RB_PARENT(old, field)) {				\
554			if (RB_LEFT(RB_PARENT(old, field), field) == old)\
555				RB_LEFT(RB_PARENT(old, field), field) = elm;\
556			else						\
557				RB_RIGHT(RB_PARENT(old, field), field) = elm;\
558			RB_AUGMENT(RB_PARENT(old, field));		\
559		} else							\
560			RB_ROOT(head) = elm;				\
561		RB_PARENT(RB_LEFT(old, field), field) = elm;		\
562		if (RB_RIGHT(old, field))				\
563			RB_PARENT(RB_RIGHT(old, field), field) = elm;	\
564		if (parent) {						\
565			left = parent;					\
566			do {						\
567				RB_AUGMENT(left);			\
568			} while ((left = RB_PARENT(left, field)) != NULL); \
569		}							\
570		goto color;						\
571	}								\
572	parent = RB_PARENT(elm, field);					\
573	color = RB_COLOR(elm, field);					\
574	if (child)							\
575		RB_PARENT(child, field) = parent;			\
576	if (parent) {							\
577		if (RB_LEFT(parent, field) == elm)			\
578			RB_LEFT(parent, field) = child;			\
579		else							\
580			RB_RIGHT(parent, field) = child;		\
581		RB_AUGMENT(parent);					\
582	} else								\
583		RB_ROOT(head) = child;					\
584color:									\
585	if (color == RB_BLACK)						\
586		name##_RB_REMOVE_COLOR(head, parent, child);		\
587	return (old);							\
588}									\
589									\
590/* Inserts a node into the RB tree */					\
591attr struct type *							\
592name##_RB_INSERT(struct name *head, struct type *elm)			\
593{									\
594	struct type *tmp;						\
595	struct type *parent = NULL;					\
596	int comp = 0;							\
597	tmp = RB_ROOT(head);						\
598	while (tmp) {							\
599		parent = tmp;						\
600		comp = (cmp)(elm, parent);				\
601		if (comp < 0)						\
602			tmp = RB_LEFT(tmp, field);			\
603		else if (comp > 0)					\
604			tmp = RB_RIGHT(tmp, field);			\
605		else							\
606			return (tmp);					\
607	}								\
608	RB_SET(elm, parent, field);					\
609	if (parent != NULL) {						\
610		if (comp < 0)						\
611			RB_LEFT(parent, field) = elm;			\
612		else							\
613			RB_RIGHT(parent, field) = elm;			\
614		RB_AUGMENT(parent);					\
615	} else								\
616		RB_ROOT(head) = elm;					\
617	name##_RB_INSERT_COLOR(head, elm);				\
618	return (NULL);							\
619}									\
620									\
621/* Finds the node with the same key as elm */				\
622attr struct type *							\
623name##_RB_FIND(struct name *head, struct type *elm)			\
624{									\
625	struct type *tmp = RB_ROOT(head);				\
626	int comp;							\
627	while (tmp) {							\
628		comp = cmp(elm, tmp);					\
629		if (comp < 0)						\
630			tmp = RB_LEFT(tmp, field);			\
631		else if (comp > 0)					\
632			tmp = RB_RIGHT(tmp, field);			\
633		else							\
634			return (tmp);					\
635	}								\
636	return (NULL);							\
637}									\
638									\
639/* Finds the first node greater than or equal to the search key */	\
640attr struct type *							\
641name##_RB_NFIND(struct name *head, struct type *elm)			\
642{									\
643	struct type *tmp = RB_ROOT(head);				\
644	struct type *res = NULL;					\
645	int comp;							\
646	while (tmp) {							\
647		comp = cmp(elm, tmp);					\
648		if (comp < 0) {						\
649			res = tmp;					\
650			tmp = RB_LEFT(tmp, field);			\
651		}							\
652		else if (comp > 0)					\
653			tmp = RB_RIGHT(tmp, field);			\
654		else							\
655			return (tmp);					\
656	}								\
657	return (res);							\
658}									\
659									\
660/* ARGSUSED */								\
661attr struct type *							\
662name##_RB_NEXT(struct type *elm)					\
663{									\
664	if (RB_RIGHT(elm, field)) {					\
665		elm = RB_RIGHT(elm, field);				\
666		while (RB_LEFT(elm, field))				\
667			elm = RB_LEFT(elm, field);			\
668	} else {							\
669		if (RB_PARENT(elm, field) &&				\
670		    (elm == RB_LEFT(RB_PARENT(elm, field), field)))	\
671			elm = RB_PARENT(elm, field);			\
672		else {							\
673			while (RB_PARENT(elm, field) &&			\
674			    (elm == RB_RIGHT(RB_PARENT(elm, field), field)))\
675				elm = RB_PARENT(elm, field);		\
676			elm = RB_PARENT(elm, field);			\
677		}							\
678	}								\
679	return (elm);							\
680}									\
681									\
682/* ARGSUSED */								\
683attr struct type *							\
684name##_RB_PREV(struct type *elm)					\
685{									\
686	if (RB_LEFT(elm, field)) {					\
687		elm = RB_LEFT(elm, field);				\
688		while (RB_RIGHT(elm, field))				\
689			elm = RB_RIGHT(elm, field);			\
690	} else {							\
691		if (RB_PARENT(elm, field) &&				\
692		    (elm == RB_RIGHT(RB_PARENT(elm, field), field)))	\
693			elm = RB_PARENT(elm, field);			\
694		else {							\
695			while (RB_PARENT(elm, field) &&			\
696			    (elm == RB_LEFT(RB_PARENT(elm, field), field)))\
697				elm = RB_PARENT(elm, field);		\
698			elm = RB_PARENT(elm, field);			\
699		}							\
700	}								\
701	return (elm);							\
702}									\
703									\
704attr struct type *							\
705name##_RB_MINMAX(struct name *head, int val)				\
706{									\
707	struct type *tmp = RB_ROOT(head);				\
708	struct type *parent = NULL;					\
709	while (tmp) {							\
710		parent = tmp;						\
711		if (val < 0)						\
712			tmp = RB_LEFT(tmp, field);			\
713		else							\
714			tmp = RB_RIGHT(tmp, field);			\
715	}								\
716	return (parent);						\
717}
718
719#define RB_NEGINF	-1
720#define RB_INF	1
721
722#define RB_INSERT(name, x, y)	name##_RB_INSERT(x, y)
723#define RB_REMOVE(name, x, y)	name##_RB_REMOVE(x, y)
724#define RB_FIND(name, x, y)	name##_RB_FIND(x, y)
725#define RB_NFIND(name, x, y)	name##_RB_NFIND(x, y)
726#define RB_NEXT(name, x, y)	name##_RB_NEXT(y)
727#define RB_PREV(name, x, y)	name##_RB_PREV(y)
728#define RB_MIN(name, x)		name##_RB_MINMAX(x, RB_NEGINF)
729#define RB_MAX(name, x)		name##_RB_MINMAX(x, RB_INF)
730
731#define RB_FOREACH(x, name, head)					\
732	for ((x) = RB_MIN(name, head);					\
733	     (x) != NULL;						\
734	     (x) = name##_RB_NEXT(x))
735
736#define RB_FOREACH_FROM(x, name, y)					\
737	for ((x) = (y);							\
738	    ((x) != NULL) && ((y) = name##_RB_NEXT(x), (x) != NULL);	\
739	     (x) = (y))
740
741#define RB_FOREACH_SAFE(x, name, head, y)				\
742	for ((x) = RB_MIN(name, head);					\
743	    ((x) != NULL) && ((y) = name##_RB_NEXT(x), (x) != NULL);	\
744	     (x) = (y))
745
746#define RB_FOREACH_REVERSE(x, name, head)				\
747	for ((x) = RB_MAX(name, head);					\
748	     (x) != NULL;						\
749	     (x) = name##_RB_PREV(x))
750
751#define RB_FOREACH_REVERSE_FROM(x, name, y)				\
752	for ((x) = (y);							\
753	    ((x) != NULL) && ((y) = name##_RB_PREV(x), (x) != NULL);	\
754	     (x) = (y))
755
756#define RB_FOREACH_REVERSE_SAFE(x, name, head, y)			\
757	for ((x) = RB_MAX(name, head);					\
758	    ((x) != NULL) && ((y) = name##_RB_PREV(x), (x) != NULL);	\
759	     (x) = (y))
760
761#endif	/* _SYS_TREE_H_ */