1/*	$OpenBSD: tree.h,v 1.30 2020/10/10 18:03:41 otto 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#include <sys/_null.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 __unused __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 __unused __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 __unused __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-black 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)	do {} while (0)
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	RB_PROTOTYPE_INTERNAL(name, type, field, cmp,)
380#define	RB_PROTOTYPE_STATIC(name, type, field, cmp)			\
381	RB_PROTOTYPE_INTERNAL(name, type, field, cmp, __attribute__((__unused__)) static)
382#define RB_PROTOTYPE_INTERNAL(name, type, field, cmp, attr)		\
383attr void name##_RB_INSERT_COLOR(struct name *, struct type *);		\
384attr void name##_RB_REMOVE_COLOR(struct name *, struct type *, struct type *);\
385attr struct type *name##_RB_REMOVE(struct name *, struct type *);	\
386attr struct type *name##_RB_INSERT(struct name *, struct type *);	\
387attr struct type *name##_RB_FIND(struct name *, struct type *);		\
388attr struct type *name##_RB_NFIND(struct name *, struct type *);	\
389attr struct type *name##_RB_NEXT(struct type *);			\
390attr struct type *name##_RB_PREV(struct type *);			\
391attr struct type *name##_RB_MINMAX(struct name *, int);			\
392									\
393
394/* Main rb operation.
395 * Moves node close to the key of elm to top
396 */
397#define	RB_GENERATE(name, type, field, cmp)				\
398	RB_GENERATE_INTERNAL(name, type, field, cmp,)
399#define	RB_GENERATE_STATIC(name, type, field, cmp)			\
400	RB_GENERATE_INTERNAL(name, type, field, cmp, __attribute__((__unused__)) static)
401#define RB_GENERATE_INTERNAL(name, type, field, cmp, attr)		\
402attr void								\
403name##_RB_INSERT_COLOR(struct name *head, struct type *elm)		\
404{									\
405	struct type *parent, *gparent, *tmp;				\
406	while ((parent = RB_PARENT(elm, field)) &&			\
407	    RB_COLOR(parent, field) == RB_RED) {			\
408		gparent = RB_PARENT(parent, field);			\
409		if (parent == RB_LEFT(gparent, field)) {		\
410			tmp = RB_RIGHT(gparent, field);			\
411			if (tmp && RB_COLOR(tmp, field) == RB_RED) {	\
412				RB_COLOR(tmp, field) = RB_BLACK;	\
413				RB_SET_BLACKRED(parent, gparent, field);\
414				elm = gparent;				\
415				continue;				\
416			}						\
417			if (RB_RIGHT(parent, field) == elm) {		\
418				RB_ROTATE_LEFT(head, parent, tmp, field);\
419				tmp = parent;				\
420				parent = elm;				\
421				elm = tmp;				\
422			}						\
423			RB_SET_BLACKRED(parent, gparent, field);	\
424			RB_ROTATE_RIGHT(head, gparent, tmp, field);	\
425		} else {						\
426			tmp = RB_LEFT(gparent, field);			\
427			if (tmp && RB_COLOR(tmp, field) == RB_RED) {	\
428				RB_COLOR(tmp, field) = RB_BLACK;	\
429				RB_SET_BLACKRED(parent, gparent, field);\
430				elm = gparent;				\
431				continue;				\
432			}						\
433			if (RB_LEFT(parent, field) == elm) {		\
434				RB_ROTATE_RIGHT(head, parent, tmp, field);\
435				tmp = parent;				\
436				parent = elm;				\
437				elm = tmp;				\
438			}						\
439			RB_SET_BLACKRED(parent, gparent, field);	\
440			RB_ROTATE_LEFT(head, gparent, tmp, field);	\
441		}							\
442	}								\
443	RB_COLOR(head->rbh_root, field) = RB_BLACK;			\
444}									\
445									\
446attr void								\
447name##_RB_REMOVE_COLOR(struct name *head, struct type *parent, struct type *elm) \
448{									\
449	struct type *tmp;						\
450	while ((elm == NULL || RB_COLOR(elm, field) == RB_BLACK) &&	\
451	    elm != RB_ROOT(head)) {					\
452		if (RB_LEFT(parent, field) == elm) {			\
453			tmp = RB_RIGHT(parent, field);			\
454			if (RB_COLOR(tmp, field) == RB_RED) {		\
455				RB_SET_BLACKRED(tmp, parent, field);	\
456				RB_ROTATE_LEFT(head, parent, tmp, field);\
457				tmp = RB_RIGHT(parent, field);		\
458			}						\
459			if ((RB_LEFT(tmp, field) == NULL ||		\
460			    RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
461			    (RB_RIGHT(tmp, field) == NULL ||		\
462			    RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
463				RB_COLOR(tmp, field) = RB_RED;		\
464				elm = parent;				\
465				parent = RB_PARENT(elm, field);		\
466			} else {					\
467				if (RB_RIGHT(tmp, field) == NULL ||	\
468				    RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK) {\
469					struct type *oleft;		\
470					if ((oleft = RB_LEFT(tmp, field)))\
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						RB_COLOR(oright, field) = RB_BLACK;\
504					RB_COLOR(tmp, field) = RB_RED;	\
505					RB_ROTATE_LEFT(head, tmp, oright, field);\
506					tmp = RB_LEFT(parent, field);	\
507				}					\
508				RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
509				RB_COLOR(parent, field) = RB_BLACK;	\
510				if (RB_LEFT(tmp, field))		\
511					RB_COLOR(RB_LEFT(tmp, field), field) = RB_BLACK;\
512				RB_ROTATE_RIGHT(head, parent, tmp, field);\
513				elm = RB_ROOT(head);			\
514				break;					\
515			}						\
516		}							\
517	}								\
518	if (elm)							\
519		RB_COLOR(elm, field) = RB_BLACK;			\
520}									\
521									\
522attr struct type *							\
523name##_RB_REMOVE(struct name *head, struct type *elm)			\
524{									\
525	struct type *child, *parent, *old = elm;			\
526	int color;							\
527	if (RB_LEFT(elm, field) == NULL)				\
528		child = RB_RIGHT(elm, field);				\
529	else if (RB_RIGHT(elm, field) == NULL)				\
530		child = RB_LEFT(elm, field);				\
531	else {								\
532		struct type *left;					\
533		elm = RB_RIGHT(elm, field);				\
534		while ((left = RB_LEFT(elm, field)))			\
535			elm = left;					\
536		child = RB_RIGHT(elm, field);				\
537		parent = RB_PARENT(elm, field);				\
538		color = RB_COLOR(elm, field);				\
539		if (child)						\
540			RB_PARENT(child, field) = parent;		\
541		if (parent) {						\
542			if (RB_LEFT(parent, field) == elm)		\
543				RB_LEFT(parent, field) = child;		\
544			else						\
545				RB_RIGHT(parent, field) = child;	\
546			RB_AUGMENT(parent);				\
547		} else							\
548			RB_ROOT(head) = child;				\
549		if (RB_PARENT(elm, field) == old)			\
550			parent = elm;					\
551		(elm)->field = (old)->field;				\
552		if (RB_PARENT(old, field)) {				\
553			if (RB_LEFT(RB_PARENT(old, field), field) == old)\
554				RB_LEFT(RB_PARENT(old, field), field) = elm;\
555			else						\
556				RB_RIGHT(RB_PARENT(old, field), field) = elm;\
557			RB_AUGMENT(RB_PARENT(old, field));		\
558		} else							\
559			RB_ROOT(head) = elm;				\
560		RB_PARENT(RB_LEFT(old, field), field) = elm;		\
561		if (RB_RIGHT(old, field))				\
562			RB_PARENT(RB_RIGHT(old, field), field) = elm;	\
563		if (parent) {						\
564			left = parent;					\
565			do {						\
566				RB_AUGMENT(left);			\
567			} while ((left = RB_PARENT(left, field)));	\
568		}							\
569		goto color;						\
570	}								\
571	parent = RB_PARENT(elm, field);					\
572	color = RB_COLOR(elm, field);					\
573	if (child)							\
574		RB_PARENT(child, field) = parent;			\
575	if (parent) {							\
576		if (RB_LEFT(parent, field) == elm)			\
577			RB_LEFT(parent, field) = child;			\
578		else							\
579			RB_RIGHT(parent, field) = child;		\
580		RB_AUGMENT(parent);					\
581	} else								\
582		RB_ROOT(head) = child;					\
583color:									\
584	if (color == RB_BLACK)						\
585		name##_RB_REMOVE_COLOR(head, parent, child);		\
586	return (old);							\
587}									\
588									\
589/* Inserts a node into the RB tree */					\
590attr struct type *							\
591name##_RB_INSERT(struct name *head, struct type *elm)			\
592{									\
593	struct type *tmp;						\
594	struct type *parent = NULL;					\
595	int comp = 0;							\
596	tmp = RB_ROOT(head);						\
597	while (tmp) {							\
598		parent = tmp;						\
599		comp = (cmp)(elm, parent);				\
600		if (comp < 0)						\
601			tmp = RB_LEFT(tmp, field);			\
602		else if (comp > 0)					\
603			tmp = RB_RIGHT(tmp, field);			\
604		else							\
605			return (tmp);					\
606	}								\
607	RB_SET(elm, parent, field);					\
608	if (parent != NULL) {						\
609		if (comp < 0)						\
610			RB_LEFT(parent, field) = elm;			\
611		else							\
612			RB_RIGHT(parent, field) = elm;			\
613		RB_AUGMENT(parent);					\
614	} else								\
615		RB_ROOT(head) = elm;					\
616	name##_RB_INSERT_COLOR(head, elm);				\
617	return (NULL);							\
618}									\
619									\
620/* Finds the node with the same key as elm */				\
621attr struct type *							\
622name##_RB_FIND(struct name *head, struct type *elm)			\
623{									\
624	struct type *tmp = RB_ROOT(head);				\
625	int comp;							\
626	while (tmp) {							\
627		comp = cmp(elm, tmp);					\
628		if (comp < 0)						\
629			tmp = RB_LEFT(tmp, field);			\
630		else if (comp > 0)					\
631			tmp = RB_RIGHT(tmp, field);			\
632		else							\
633			return (tmp);					\
634	}								\
635	return (NULL);							\
636}									\
637									\
638/* Finds the first node greater than or equal to the search key */	\
639attr struct type *							\
640name##_RB_NFIND(struct name *head, struct type *elm)			\
641{									\
642	struct type *tmp = RB_ROOT(head);				\
643	struct type *res = NULL;					\
644	int comp;							\
645	while (tmp) {							\
646		comp = cmp(elm, tmp);					\
647		if (comp < 0) {						\
648			res = tmp;					\
649			tmp = RB_LEFT(tmp, field);			\
650		}							\
651		else if (comp > 0)					\
652			tmp = RB_RIGHT(tmp, field);			\
653		else							\
654			return (tmp);					\
655	}								\
656	return (res);							\
657}									\
658									\
659/* ARGSUSED */								\
660attr struct type *							\
661name##_RB_NEXT(struct type *elm)					\
662{									\
663	if (RB_RIGHT(elm, field)) {					\
664		elm = RB_RIGHT(elm, field);				\
665		while (RB_LEFT(elm, field))				\
666			elm = RB_LEFT(elm, field);			\
667	} else {							\
668		if (RB_PARENT(elm, field) &&				\
669		    (elm == RB_LEFT(RB_PARENT(elm, field), field)))	\
670			elm = RB_PARENT(elm, field);			\
671		else {							\
672			while (RB_PARENT(elm, field) &&			\
673			    (elm == RB_RIGHT(RB_PARENT(elm, field), field)))\
674				elm = RB_PARENT(elm, field);		\
675			elm = RB_PARENT(elm, field);			\
676		}							\
677	}								\
678	return (elm);							\
679}									\
680									\
681/* ARGSUSED */								\
682attr struct type *							\
683name##_RB_PREV(struct type *elm)					\
684{									\
685	if (RB_LEFT(elm, field)) {					\
686		elm = RB_LEFT(elm, field);				\
687		while (RB_RIGHT(elm, field))				\
688			elm = RB_RIGHT(elm, field);			\
689	} else {							\
690		if (RB_PARENT(elm, field) &&				\
691		    (elm == RB_RIGHT(RB_PARENT(elm, field), field)))	\
692			elm = RB_PARENT(elm, field);			\
693		else {							\
694			while (RB_PARENT(elm, field) &&			\
695			    (elm == RB_LEFT(RB_PARENT(elm, field), field)))\
696				elm = RB_PARENT(elm, field);		\
697			elm = RB_PARENT(elm, field);			\
698		}							\
699	}								\
700	return (elm);							\
701}									\
702									\
703attr struct type *							\
704name##_RB_MINMAX(struct name *head, int val)				\
705{									\
706	struct type *tmp = RB_ROOT(head);				\
707	struct type *parent = NULL;					\
708	while (tmp) {							\
709		parent = tmp;						\
710		if (val < 0)						\
711			tmp = RB_LEFT(tmp, field);			\
712		else							\
713			tmp = RB_RIGHT(tmp, field);			\
714	}								\
715	return (parent);						\
716}
717
718#define RB_NEGINF	-1
719#define RB_INF	1
720
721#define RB_INSERT(name, x, y)	name##_RB_INSERT(x, y)
722#define RB_REMOVE(name, x, y)	name##_RB_REMOVE(x, y)
723#define RB_FIND(name, x, y)	name##_RB_FIND(x, y)
724#define RB_NFIND(name, x, y)	name##_RB_NFIND(x, y)
725#define RB_NEXT(name, x, y)	name##_RB_NEXT(y)
726#define RB_PREV(name, x, y)	name##_RB_PREV(y)
727#define RB_MIN(name, x)		name##_RB_MINMAX(x, RB_NEGINF)
728#define RB_MAX(name, x)		name##_RB_MINMAX(x, RB_INF)
729
730#define RB_FOREACH(x, name, head)					\
731	for ((x) = RB_MIN(name, head);					\
732	     (x) != NULL;						\
733	     (x) = name##_RB_NEXT(x))
734
735#define RB_FOREACH_SAFE(x, name, head, y)				\
736	for ((x) = RB_MIN(name, head);					\
737	    ((x) != NULL) && ((y) = name##_RB_NEXT(x), 1);		\
738	     (x) = (y))
739
740#define RB_FOREACH_REVERSE(x, name, head)				\
741	for ((x) = RB_MAX(name, head);					\
742	     (x) != NULL;						\
743	     (x) = name##_RB_PREV(x))
744
745#define RB_FOREACH_REVERSE_SAFE(x, name, head, y)			\
746	for ((x) = RB_MAX(name, head);					\
747	    ((x) != NULL) && ((y) = name##_RB_PREV(x), 1);		\
748	     (x) = (y))
749
750
751/*
752 * Copyright (c) 2016 David Gwynne <dlg@openbsd.org>
753 *
754 * Permission to use, copy, modify, and distribute this software for any
755 * purpose with or without fee is hereby granted, provided that the above
756 * copyright notice and this permission notice appear in all copies.
757 *
758 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
759 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
760 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
761 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
762 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
763 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
764 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
765 */
766
767struct rb_type {
768	int		(*t_compare)(const void *, const void *);
769	void		(*t_augment)(void *);
770	unsigned int	  t_offset;	/* offset of rb_entry in type */
771};
772
773struct rb_tree {
774	struct rb_entry	*rbt_root;
775};
776
777struct rb_entry {
778	struct rb_entry	 *rbt_parent;
779	struct rb_entry	 *rbt_left;
780	struct rb_entry	 *rbt_right;
781	unsigned int	  rbt_color;
782};
783
784#define RBT_HEAD(_name, _type)						\
785struct _name {								\
786	struct rb_tree rbh_root;					\
787}
788
789#define RBT_ENTRY(_type)	struct rb_entry
790
791static inline void
792_rb_init(struct rb_tree *rbt)
793{
794	rbt->rbt_root = NULL;
795}
796
797static inline int
798_rb_empty(struct rb_tree *rbt)
799{
800	return (rbt->rbt_root == NULL);
801}
802
803void	*_rb_insert(const struct rb_type *, struct rb_tree *, void *);
804void	*_rb_remove(const struct rb_type *, struct rb_tree *, void *);
805void	*_rb_find(const struct rb_type *, struct rb_tree *, const void *);
806void	*_rb_nfind(const struct rb_type *, struct rb_tree *, const void *);
807void	*_rb_root(const struct rb_type *, struct rb_tree *);
808void	*_rb_min(const struct rb_type *, struct rb_tree *);
809void	*_rb_max(const struct rb_type *, struct rb_tree *);
810void	*_rb_next(const struct rb_type *, void *);
811void	*_rb_prev(const struct rb_type *, void *);
812void	*_rb_left(const struct rb_type *, void *);
813void	*_rb_right(const struct rb_type *, void *);
814void	*_rb_parent(const struct rb_type *, void *);
815void	 _rb_set_left(const struct rb_type *, void *, void *);
816void	 _rb_set_right(const struct rb_type *, void *, void *);
817void	 _rb_set_parent(const struct rb_type *, void *, void *);
818void	 _rb_poison(const struct rb_type *, void *, unsigned long);
819int	 _rb_check(const struct rb_type *, void *, unsigned long);
820
821#define RBT_INITIALIZER(_head)	{ { NULL } }
822
823#define RBT_PROTOTYPE(_name, _type, _field, _cmp)			\
824extern const struct rb_type *const _name##_RBT_TYPE;			\
825									\
826__unused static inline void						\
827_name##_RBT_INIT(struct _name *head)					\
828{									\
829	_rb_init(&head->rbh_root);					\
830}									\
831									\
832__unused static inline struct _type *					\
833_name##_RBT_INSERT(struct _name *head, struct _type *elm)		\
834{									\
835	return _rb_insert(_name##_RBT_TYPE, &head->rbh_root, elm);	\
836}									\
837									\
838__unused static inline struct _type *					\
839_name##_RBT_REMOVE(struct _name *head, struct _type *elm)		\
840{									\
841	return _rb_remove(_name##_RBT_TYPE, &head->rbh_root, elm);	\
842}									\
843									\
844__unused static inline struct _type *					\
845_name##_RBT_FIND(struct _name *head, const struct _type *key)		\
846{									\
847	return _rb_find(_name##_RBT_TYPE, &head->rbh_root, key);	\
848}									\
849									\
850__unused static inline struct _type *					\
851_name##_RBT_NFIND(struct _name *head, const struct _type *key)		\
852{									\
853	return _rb_nfind(_name##_RBT_TYPE, &head->rbh_root, key);	\
854}									\
855									\
856__unused static inline struct _type *					\
857_name##_RBT_ROOT(struct _name *head)					\
858{									\
859	return _rb_root(_name##_RBT_TYPE, &head->rbh_root);		\
860}									\
861									\
862__unused static inline int						\
863_name##_RBT_EMPTY(struct _name *head)					\
864{									\
865	return _rb_empty(&head->rbh_root);				\
866}									\
867									\
868__unused static inline struct _type *					\
869_name##_RBT_MIN(struct _name *head)					\
870{									\
871	return _rb_min(_name##_RBT_TYPE, &head->rbh_root);		\
872}									\
873									\
874__unused static inline struct _type *					\
875_name##_RBT_MAX(struct _name *head)					\
876{									\
877	return _rb_max(_name##_RBT_TYPE, &head->rbh_root);		\
878}									\
879									\
880__unused static inline struct _type *					\
881_name##_RBT_NEXT(struct _type *elm)					\
882{									\
883	return _rb_next(_name##_RBT_TYPE, elm);				\
884}									\
885									\
886__unused static inline struct _type *					\
887_name##_RBT_PREV(struct _type *elm)					\
888{									\
889	return _rb_prev(_name##_RBT_TYPE, elm);				\
890}									\
891									\
892__unused static inline struct _type *					\
893_name##_RBT_LEFT(struct _type *elm)					\
894{									\
895	return _rb_left(_name##_RBT_TYPE, elm);				\
896}									\
897									\
898__unused static inline struct _type *					\
899_name##_RBT_RIGHT(struct _type *elm)					\
900{									\
901	return _rb_right(_name##_RBT_TYPE, elm);			\
902}									\
903									\
904__unused static inline struct _type *					\
905_name##_RBT_PARENT(struct _type *elm)					\
906{									\
907	return _rb_parent(_name##_RBT_TYPE, elm);			\
908}									\
909									\
910__unused static inline void						\
911_name##_RBT_SET_LEFT(struct _type *elm, struct _type *left)		\
912{									\
913	_rb_set_left(_name##_RBT_TYPE, elm, left);			\
914}									\
915									\
916__unused static inline void						\
917_name##_RBT_SET_RIGHT(struct _type *elm, struct _type *right)		\
918{									\
919	_rb_set_right(_name##_RBT_TYPE, elm, right);			\
920}									\
921									\
922__unused static inline void						\
923_name##_RBT_SET_PARENT(struct _type *elm, struct _type *parent)		\
924{									\
925	_rb_set_parent(_name##_RBT_TYPE, elm, parent);			\
926}									\
927									\
928__unused static inline void						\
929_name##_RBT_POISON(struct _type *elm, unsigned long poison)		\
930{									\
931	_rb_poison(_name##_RBT_TYPE, elm, poison);			\
932}									\
933									\
934__unused static inline int						\
935_name##_RBT_CHECK(struct _type *elm, unsigned long poison)		\
936{									\
937	return _rb_check(_name##_RBT_TYPE, elm, poison);		\
938}
939
940#define RBT_GENERATE_INTERNAL(_name, _type, _field, _cmp, _aug)		\
941static int								\
942_name##_RBT_COMPARE(const void *lptr, const void *rptr)			\
943{									\
944	const struct _type *l = lptr, *r = rptr;			\
945	return _cmp(l, r);						\
946}									\
947static const struct rb_type _name##_RBT_INFO = {			\
948	_name##_RBT_COMPARE,						\
949	_aug,								\
950	offsetof(struct _type, _field),					\
951};									\
952const struct rb_type *const _name##_RBT_TYPE = &_name##_RBT_INFO
953
954#define RBT_GENERATE_AUGMENT(_name, _type, _field, _cmp, _aug)		\
955static void								\
956_name##_RBT_AUGMENT(void *ptr)						\
957{									\
958	struct _type *p = ptr;						\
959	return _aug(p);							\
960}									\
961RBT_GENERATE_INTERNAL(_name, _type, _field, _cmp, _name##_RBT_AUGMENT)
962
963#define RBT_GENERATE(_name, _type, _field, _cmp)			\
964    RBT_GENERATE_INTERNAL(_name, _type, _field, _cmp, NULL)
965
966#define RBT_INIT(_name, _head)		_name##_RBT_INIT(_head)
967#define RBT_INSERT(_name, _head, _elm)	_name##_RBT_INSERT(_head, _elm)
968#define RBT_REMOVE(_name, _head, _elm)	_name##_RBT_REMOVE(_head, _elm)
969#define RBT_FIND(_name, _head, _key)	_name##_RBT_FIND(_head, _key)
970#define RBT_NFIND(_name, _head, _key)	_name##_RBT_NFIND(_head, _key)
971#define RBT_ROOT(_name, _head)		_name##_RBT_ROOT(_head)
972#define RBT_EMPTY(_name, _head)		_name##_RBT_EMPTY(_head)
973#define RBT_MIN(_name, _head)		_name##_RBT_MIN(_head)
974#define RBT_MAX(_name, _head)		_name##_RBT_MAX(_head)
975#define RBT_NEXT(_name, _elm)		_name##_RBT_NEXT(_elm)
976#define RBT_PREV(_name, _elm)		_name##_RBT_PREV(_elm)
977#define RBT_LEFT(_name, _elm)		_name##_RBT_LEFT(_elm)
978#define RBT_RIGHT(_name, _elm)		_name##_RBT_RIGHT(_elm)
979#define RBT_PARENT(_name, _elm)		_name##_RBT_PARENT(_elm)
980#define RBT_SET_LEFT(_name, _elm, _l)	_name##_RBT_SET_LEFT(_elm, _l)
981#define RBT_SET_RIGHT(_name, _elm, _r)	_name##_RBT_SET_RIGHT(_elm, _r)
982#define RBT_SET_PARENT(_name, _elm, _p)	_name##_RBT_SET_PARENT(_elm, _p)
983#define RBT_POISON(_name, _elm, _p)	_name##_RBT_POISON(_elm, _p)
984#define RBT_CHECK(_name, _elm, _p)	_name##_RBT_CHECK(_elm, _p)
985
986#define RBT_FOREACH(_e, _name, _head)					\
987	for ((_e) = RBT_MIN(_name, (_head));				\
988	     (_e) != NULL;						\
989	     (_e) = RBT_NEXT(_name, (_e)))
990
991#define RBT_FOREACH_SAFE(_e, _name, _head, _n)				\
992	for ((_e) = RBT_MIN(_name, (_head));				\
993	     (_e) != NULL && ((_n) = RBT_NEXT(_name, (_e)), 1);	\
994	     (_e) = (_n))
995
996#define RBT_FOREACH_REVERSE(_e, _name, _head)				\
997	for ((_e) = RBT_MAX(_name, (_head));				\
998	     (_e) != NULL;						\
999	     (_e) = RBT_PREV(_name, (_e)))
1000
1001#define RBT_FOREACH_REVERSE_SAFE(_e, _name, _head, _n)			\
1002	for ((_e) = RBT_MAX(_name, (_head));				\
1003	     (_e) != NULL && ((_n) = RBT_PREV(_name, (_e)), 1);	\
1004	     (_e) = (_n))
1005
1006#endif	/* _SYS_TREE_H_ */
1007