sys-tree.h revision 157017
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/* OPENBSD ORIGINAL: sys/sys/tree.h */
28
29#ifndef	_SYS_TREE_H_
30#define	_SYS_TREE_H_
31
32/*
33 * This file defines data structures for different types of trees:
34 * splay trees and red-black trees.
35 *
36 * A splay tree is a self-organizing data structure.  Every operation
37 * on the tree causes a splay to happen.  The splay moves the requested
38 * node to the root of the tree and partly rebalances it.
39 *
40 * This has the benefit that request locality causes faster lookups as
41 * the requested nodes move to the top of the tree.  On the other hand,
42 * every lookup causes memory writes.
43 *
44 * The Balance Theorem bounds the total access time for m operations
45 * and n inserts on an initially empty tree as O((m + n)lg n).  The
46 * amortized cost for a sequence of m accesses to a splay tree is O(lg n);
47 *
48 * A red-black tree is a binary search tree with the node color as an
49 * extra attribute.  It fulfills a set of conditions:
50 *	- every search path from the root to a leaf consists of the
51 *	  same number of black nodes,
52 *	- each red node (except for the root) has a black parent,
53 *	- each leaf node is black.
54 *
55 * Every operation on a red-black tree is bounded as O(lg n).
56 * The maximum height of a red-black tree is 2lg (n+1).
57 */
58
59#define SPLAY_HEAD(name, type)						\
60struct 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)						\
72struct {								\
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)				\
117void name##_SPLAY(struct name *, struct type *);			\
118void name##_SPLAY_MINMAX(struct name *, int);				\
119struct type *name##_SPLAY_INSERT(struct name *, struct type *);		\
120struct type *name##_SPLAY_REMOVE(struct name *, struct type *);		\
121									\
122/* Finds the node with the same key as elm */				\
123static __inline struct type *						\
124name##_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									\
134static __inline struct type *						\
135name##_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									\
148static __inline struct type *						\
149name##_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)				\
159struct type *								\
160name##_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									\
183struct type *								\
184name##_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									\
204void									\
205name##_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 */									\
242void 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)						\
294struct 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)							\
308struct {								\
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)				\
379void name##_RB_INSERT_COLOR(struct name *, struct type *);	\
380void name##_RB_REMOVE_COLOR(struct name *, struct type *, struct type *);\
381struct type *name##_RB_REMOVE(struct name *, struct type *);		\
382struct type *name##_RB_INSERT(struct name *, struct type *);		\
383struct type *name##_RB_FIND(struct name *, struct type *);		\
384struct type *name##_RB_NEXT(struct name *, struct type *);		\
385struct 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)				\
392void									\
393name##_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									\
436void									\
437name##_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									\
512struct type *								\
513name##_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;					\
573color:									\
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 */					\
580struct type *								\
581name##_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 */				\
611struct type *								\
612name##_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									\
628struct type *								\
629name##_RB_NEXT(struct name *head, 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									\
649struct type *								\
650name##_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(x, 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(head, x))
678
679#endif	/* _SYS_TREE_H_ */
680