WPILibC++ 2027.0.0-alpha-2
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tree.h
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1/*-
2 * Copyright 2002 Niels Provos <provos@citi.umich.edu>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#ifndef UV_TREE_H_
27#define UV_TREE_H_
28
29#ifndef UV__UNUSED
30# if __GNUC__
31# define UV__UNUSED __attribute__((unused))
32# else
33# define UV__UNUSED
34# endif
35#endif
36
37/*
38 * This file defines data structures for red-black trees.
39 * A red-black tree is a binary search tree with the node color as an
40 * extra attribute. It fulfills a set of conditions:
41 * - every search path from the root to a leaf consists of the
42 * same number of black nodes,
43 * - each red node (except for the root) has a black parent,
44 * - each leaf node is black.
45 *
46 * Every operation on a red-black tree is bounded as O(lg n).
47 * The maximum height of a red-black tree is 2lg (n+1).
48 */
49
50/* Macros that define a red-black tree */
51#define RB_HEAD(name, type) \
52struct name { \
53 struct type *rbh_root; /* root of the tree */ \
54}
55
56#define RB_INITIALIZER(root) \
57 { NULL }
58
59#define RB_INIT(root) do { \
60 (root)->rbh_root = NULL; \
61} while (/*CONSTCOND*/ 0)
62
63#define RB_BLACK 0
64#define RB_RED 1
65#define RB_ENTRY(type) \
66struct { \
67 struct type *rbe_left; /* left element */ \
68 struct type *rbe_right; /* right element */ \
69 struct type *rbe_parent; /* parent element */ \
70 int rbe_color; /* node color */ \
71}
72
73#define RB_LEFT(elm, field) (elm)->field.rbe_left
74#define RB_RIGHT(elm, field) (elm)->field.rbe_right
75#define RB_PARENT(elm, field) (elm)->field.rbe_parent
76#define RB_COLOR(elm, field) (elm)->field.rbe_color
77#define RB_ROOT(head) (head)->rbh_root
78#define RB_EMPTY(head) (RB_ROOT(head) == NULL)
79
80#define RB_SET(elm, parent, field) do { \
81 RB_PARENT(elm, field) = parent; \
82 RB_LEFT(elm, field) = RB_RIGHT(elm, field) = NULL; \
83 RB_COLOR(elm, field) = RB_RED; \
84} while (/*CONSTCOND*/ 0)
85
86#define RB_SET_BLACKRED(black, red, field) do { \
87 RB_COLOR(black, field) = RB_BLACK; \
88 RB_COLOR(red, field) = RB_RED; \
89} while (/*CONSTCOND*/ 0)
90
91#ifndef RB_AUGMENT
92#define RB_AUGMENT(x) do {} while (0)
93#endif
94
95#define RB_ROTATE_LEFT(head, elm, tmp, field) do { \
96 (tmp) = RB_RIGHT(elm, field); \
97 if ((RB_RIGHT(elm, field) = RB_LEFT(tmp, field)) != NULL) { \
98 RB_PARENT(RB_LEFT(tmp, field), field) = (elm); \
99 } \
100 RB_AUGMENT(elm); \
101 if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field)) != NULL) { \
102 if ((elm) == RB_LEFT(RB_PARENT(elm, field), field)) \
103 RB_LEFT(RB_PARENT(elm, field), field) = (tmp); \
104 else \
105 RB_RIGHT(RB_PARENT(elm, field), field) = (tmp); \
106 } else \
107 (head)->rbh_root = (tmp); \
108 RB_LEFT(tmp, field) = (elm); \
109 RB_PARENT(elm, field) = (tmp); \
110 RB_AUGMENT(tmp); \
111 if ((RB_PARENT(tmp, field))) \
112 RB_AUGMENT(RB_PARENT(tmp, field)); \
113} while (/*CONSTCOND*/ 0)
114
115#define RB_ROTATE_RIGHT(head, elm, tmp, field) do { \
116 (tmp) = RB_LEFT(elm, field); \
117 if ((RB_LEFT(elm, field) = RB_RIGHT(tmp, field)) != NULL) { \
118 RB_PARENT(RB_RIGHT(tmp, field), field) = (elm); \
119 } \
120 RB_AUGMENT(elm); \
121 if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field)) != NULL) { \
122 if ((elm) == RB_LEFT(RB_PARENT(elm, field), field)) \
123 RB_LEFT(RB_PARENT(elm, field), field) = (tmp); \
124 else \
125 RB_RIGHT(RB_PARENT(elm, field), field) = (tmp); \
126 } else \
127 (head)->rbh_root = (tmp); \
128 RB_RIGHT(tmp, field) = (elm); \
129 RB_PARENT(elm, field) = (tmp); \
130 RB_AUGMENT(tmp); \
131 if ((RB_PARENT(tmp, field))) \
132 RB_AUGMENT(RB_PARENT(tmp, field)); \
133} while (/*CONSTCOND*/ 0)
134
135/* Generates prototypes and inline functions */
136#define RB_PROTOTYPE(name, type, field, cmp) \
137 RB_PROTOTYPE_INTERNAL(name, type, field, cmp,)
138#define RB_PROTOTYPE_STATIC(name, type, field, cmp) \
139 RB_PROTOTYPE_INTERNAL(name, type, field, cmp, UV__UNUSED static)
140#define RB_PROTOTYPE_INTERNAL(name, type, field, cmp, attr) \
141attr void name##_RB_INSERT_COLOR(struct name *, struct type *); \
142attr void name##_RB_REMOVE_COLOR(struct name *, struct type *, struct type *);\
143attr struct type *name##_RB_REMOVE(struct name *, struct type *); \
144attr struct type *name##_RB_INSERT(struct name *, struct type *); \
145attr struct type *name##_RB_FIND(struct name *, struct type *); \
146attr struct type *name##_RB_NFIND(struct name *, struct type *); \
147attr struct type *name##_RB_NEXT(struct type *); \
148attr struct type *name##_RB_PREV(struct type *); \
149attr struct type *name##_RB_MINMAX(struct name *, int); \
150 \
151
152/* Main rb operation.
153 * Moves node close to the key of elm to top
154 */
155#define RB_GENERATE(name, type, field, cmp) \
156 RB_GENERATE_INTERNAL(name, type, field, cmp,)
157#define RB_GENERATE_STATIC(name, type, field, cmp) \
158 RB_GENERATE_INTERNAL(name, type, field, cmp, UV__UNUSED static)
159#define RB_GENERATE_INTERNAL(name, type, field, cmp, attr) \
160attr void \
161name##_RB_INSERT_COLOR(struct name *head, struct type *elm) \
162{ \
163 struct type *parent, *gparent, *tmp; \
164 while ((parent = RB_PARENT(elm, field)) != NULL && \
165 RB_COLOR(parent, field) == RB_RED) { \
166 gparent = RB_PARENT(parent, field); \
167 if (parent == RB_LEFT(gparent, field)) { \
168 tmp = RB_RIGHT(gparent, field); \
169 if (tmp && RB_COLOR(tmp, field) == RB_RED) { \
170 RB_COLOR(tmp, field) = RB_BLACK; \
171 RB_SET_BLACKRED(parent, gparent, field); \
172 elm = gparent; \
173 continue; \
174 } \
175 if (RB_RIGHT(parent, field) == elm) { \
176 RB_ROTATE_LEFT(head, parent, tmp, field); \
177 tmp = parent; \
178 parent = elm; \
179 elm = tmp; \
180 } \
181 RB_SET_BLACKRED(parent, gparent, field); \
182 RB_ROTATE_RIGHT(head, gparent, tmp, field); \
183 } else { \
184 tmp = RB_LEFT(gparent, field); \
185 if (tmp && RB_COLOR(tmp, field) == RB_RED) { \
186 RB_COLOR(tmp, field) = RB_BLACK; \
187 RB_SET_BLACKRED(parent, gparent, field); \
188 elm = gparent; \
189 continue; \
190 } \
191 if (RB_LEFT(parent, field) == elm) { \
192 RB_ROTATE_RIGHT(head, parent, tmp, field); \
193 tmp = parent; \
194 parent = elm; \
195 elm = tmp; \
196 } \
197 RB_SET_BLACKRED(parent, gparent, field); \
198 RB_ROTATE_LEFT(head, gparent, tmp, field); \
199 } \
200 } \
201 RB_COLOR(head->rbh_root, field) = RB_BLACK; \
202} \
203 \
204attr void \
205name##_RB_REMOVE_COLOR(struct name *head, struct type *parent, \
206 struct type *elm) \
207{ \
208 struct type *tmp; \
209 while ((elm == NULL || RB_COLOR(elm, field) == RB_BLACK) && \
210 elm != RB_ROOT(head)) { \
211 if (RB_LEFT(parent, field) == elm) { \
212 tmp = RB_RIGHT(parent, field); \
213 if (RB_COLOR(tmp, field) == RB_RED) { \
214 RB_SET_BLACKRED(tmp, parent, field); \
215 RB_ROTATE_LEFT(head, parent, tmp, field); \
216 tmp = RB_RIGHT(parent, field); \
217 } \
218 if ((RB_LEFT(tmp, field) == NULL || \
219 RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) && \
220 (RB_RIGHT(tmp, field) == NULL || \
221 RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) { \
222 RB_COLOR(tmp, field) = RB_RED; \
223 elm = parent; \
224 parent = RB_PARENT(elm, field); \
225 } else { \
226 if (RB_RIGHT(tmp, field) == NULL || \
227 RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK) { \
228 struct type *oleft; \
229 if ((oleft = RB_LEFT(tmp, field)) \
230 != NULL) \
231 RB_COLOR(oleft, field) = RB_BLACK; \
232 RB_COLOR(tmp, field) = RB_RED; \
233 RB_ROTATE_RIGHT(head, tmp, oleft, field); \
234 tmp = RB_RIGHT(parent, field); \
235 } \
236 RB_COLOR(tmp, field) = RB_COLOR(parent, field); \
237 RB_COLOR(parent, field) = RB_BLACK; \
238 if (RB_RIGHT(tmp, field)) \
239 RB_COLOR(RB_RIGHT(tmp, field), field) = RB_BLACK; \
240 RB_ROTATE_LEFT(head, parent, tmp, field); \
241 elm = RB_ROOT(head); \
242 break; \
243 } \
244 } else { \
245 tmp = RB_LEFT(parent, field); \
246 if (RB_COLOR(tmp, field) == RB_RED) { \
247 RB_SET_BLACKRED(tmp, parent, field); \
248 RB_ROTATE_RIGHT(head, parent, tmp, field); \
249 tmp = RB_LEFT(parent, field); \
250 } \
251 if ((RB_LEFT(tmp, field) == NULL || \
252 RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) && \
253 (RB_RIGHT(tmp, field) == NULL || \
254 RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) { \
255 RB_COLOR(tmp, field) = RB_RED; \
256 elm = parent; \
257 parent = RB_PARENT(elm, field); \
258 } else { \
259 if (RB_LEFT(tmp, field) == NULL || \
260 RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) { \
261 struct type *oright; \
262 if ((oright = RB_RIGHT(tmp, field)) \
263 != NULL) \
264 RB_COLOR(oright, field) = RB_BLACK; \
265 RB_COLOR(tmp, field) = RB_RED; \
266 RB_ROTATE_LEFT(head, tmp, oright, field); \
267 tmp = RB_LEFT(parent, field); \
268 } \
269 RB_COLOR(tmp, field) = RB_COLOR(parent, field); \
270 RB_COLOR(parent, field) = RB_BLACK; \
271 if (RB_LEFT(tmp, field)) \
272 RB_COLOR(RB_LEFT(tmp, field), field) = RB_BLACK; \
273 RB_ROTATE_RIGHT(head, parent, tmp, field); \
274 elm = RB_ROOT(head); \
275 break; \
276 } \
277 } \
278 } \
279 if (elm) \
280 RB_COLOR(elm, field) = RB_BLACK; \
281} \
282 \
283attr struct type * \
284name##_RB_REMOVE(struct name *head, struct type *elm) \
285{ \
286 struct type *child, *parent, *old = elm; \
287 int color; \
288 if (RB_LEFT(elm, field) == NULL) \
289 child = RB_RIGHT(elm, field); \
290 else if (RB_RIGHT(elm, field) == NULL) \
291 child = RB_LEFT(elm, field); \
292 else { \
293 struct type *left; \
294 elm = RB_RIGHT(elm, field); \
295 while ((left = RB_LEFT(elm, field)) != NULL) \
296 elm = left; \
297 child = RB_RIGHT(elm, field); \
298 parent = RB_PARENT(elm, field); \
299 color = RB_COLOR(elm, field); \
300 if (child) \
301 RB_PARENT(child, field) = parent; \
302 if (parent) { \
303 if (RB_LEFT(parent, field) == elm) \
304 RB_LEFT(parent, field) = child; \
305 else \
306 RB_RIGHT(parent, field) = child; \
307 RB_AUGMENT(parent); \
308 } else \
309 RB_ROOT(head) = child; \
310 if (RB_PARENT(elm, field) == old) \
311 parent = elm; \
312 (elm)->field = (old)->field; \
313 if (RB_PARENT(old, field)) { \
314 if (RB_LEFT(RB_PARENT(old, field), field) == old) \
315 RB_LEFT(RB_PARENT(old, field), field) = elm; \
316 else \
317 RB_RIGHT(RB_PARENT(old, field), field) = elm; \
318 RB_AUGMENT(RB_PARENT(old, field)); \
319 } else \
320 RB_ROOT(head) = elm; \
321 RB_PARENT(RB_LEFT(old, field), field) = elm; \
322 if (RB_RIGHT(old, field)) \
323 RB_PARENT(RB_RIGHT(old, field), field) = elm; \
324 if (parent) { \
325 left = parent; \
326 do { \
327 RB_AUGMENT(left); \
328 } while ((left = RB_PARENT(left, field)) != NULL); \
329 } \
330 goto color; \
331 } \
332 parent = RB_PARENT(elm, field); \
333 color = RB_COLOR(elm, field); \
334 if (child) \
335 RB_PARENT(child, field) = parent; \
336 if (parent) { \
337 if (RB_LEFT(parent, field) == elm) \
338 RB_LEFT(parent, field) = child; \
339 else \
340 RB_RIGHT(parent, field) = child; \
341 RB_AUGMENT(parent); \
342 } else \
343 RB_ROOT(head) = child; \
344color: \
345 if (color == RB_BLACK) \
346 name##_RB_REMOVE_COLOR(head, parent, child); \
347 return (old); \
348} \
349 \
350/* Inserts a node into the RB tree */ \
351attr struct type * \
352name##_RB_INSERT(struct name *head, struct type *elm) \
353{ \
354 struct type *tmp; \
355 struct type *parent = NULL; \
356 int comp = 0; \
357 tmp = RB_ROOT(head); \
358 while (tmp) { \
359 parent = tmp; \
360 comp = (cmp)(elm, parent); \
361 if (comp < 0) \
362 tmp = RB_LEFT(tmp, field); \
363 else if (comp > 0) \
364 tmp = RB_RIGHT(tmp, field); \
365 else \
366 return (tmp); \
367 } \
368 RB_SET(elm, parent, field); \
369 if (parent != NULL) { \
370 if (comp < 0) \
371 RB_LEFT(parent, field) = elm; \
372 else \
373 RB_RIGHT(parent, field) = elm; \
374 RB_AUGMENT(parent); \
375 } else \
376 RB_ROOT(head) = elm; \
377 name##_RB_INSERT_COLOR(head, elm); \
378 return (NULL); \
379} \
380 \
381/* Finds the node with the same key as elm */ \
382attr struct type * \
383name##_RB_FIND(struct name *head, struct type *elm) \
384{ \
385 struct type *tmp = RB_ROOT(head); \
386 int comp; \
387 while (tmp) { \
388 comp = cmp(elm, tmp); \
389 if (comp < 0) \
390 tmp = RB_LEFT(tmp, field); \
391 else if (comp > 0) \
392 tmp = RB_RIGHT(tmp, field); \
393 else \
394 return (tmp); \
395 } \
396 return (NULL); \
397} \
398 \
399/* Finds the first node greater than or equal to the search key */ \
400attr struct type * \
401name##_RB_NFIND(struct name *head, struct type *elm) \
402{ \
403 struct type *tmp = RB_ROOT(head); \
404 struct type *res = NULL; \
405 int comp; \
406 while (tmp) { \
407 comp = cmp(elm, tmp); \
408 if (comp < 0) { \
409 res = tmp; \
410 tmp = RB_LEFT(tmp, field); \
411 } \
412 else if (comp > 0) \
413 tmp = RB_RIGHT(tmp, field); \
414 else \
415 return (tmp); \
416 } \
417 return (res); \
418} \
419 \
420/* ARGSUSED */ \
421attr struct type * \
422name##_RB_NEXT(struct type *elm) \
423{ \
424 if (RB_RIGHT(elm, field)) { \
425 elm = RB_RIGHT(elm, field); \
426 while (RB_LEFT(elm, field)) \
427 elm = RB_LEFT(elm, field); \
428 } else { \
429 if (RB_PARENT(elm, field) && \
430 (elm == RB_LEFT(RB_PARENT(elm, field), field))) \
431 elm = RB_PARENT(elm, field); \
432 else { \
433 while (RB_PARENT(elm, field) && \
434 (elm == RB_RIGHT(RB_PARENT(elm, field), field))) \
435 elm = RB_PARENT(elm, field); \
436 elm = RB_PARENT(elm, field); \
437 } \
438 } \
439 return (elm); \
440} \
441 \
442/* ARGSUSED */ \
443attr struct type * \
444name##_RB_PREV(struct type *elm) \
445{ \
446 if (RB_LEFT(elm, field)) { \
447 elm = RB_LEFT(elm, field); \
448 while (RB_RIGHT(elm, field)) \
449 elm = RB_RIGHT(elm, field); \
450 } else { \
451 if (RB_PARENT(elm, field) && \
452 (elm == RB_RIGHT(RB_PARENT(elm, field), field))) \
453 elm = RB_PARENT(elm, field); \
454 else { \
455 while (RB_PARENT(elm, field) && \
456 (elm == RB_LEFT(RB_PARENT(elm, field), field))) \
457 elm = RB_PARENT(elm, field); \
458 elm = RB_PARENT(elm, field); \
459 } \
460 } \
461 return (elm); \
462} \
463 \
464attr struct type * \
465name##_RB_MINMAX(struct name *head, int val) \
466{ \
467 struct type *tmp = RB_ROOT(head); \
468 struct type *parent = NULL; \
469 while (tmp) { \
470 parent = tmp; \
471 if (val < 0) \
472 tmp = RB_LEFT(tmp, field); \
473 else \
474 tmp = RB_RIGHT(tmp, field); \
475 } \
476 return (parent); \
477}
478
479#define RB_NEGINF -1
480#define RB_INF 1
481
482#define RB_INSERT(name, x, y) name##_RB_INSERT(x, y)
483#define RB_REMOVE(name, x, y) name##_RB_REMOVE(x, y)
484#define RB_FIND(name, x, y) name##_RB_FIND(x, y)
485#define RB_NFIND(name, x, y) name##_RB_NFIND(x, y)
486#define RB_NEXT(name, x) name##_RB_NEXT(x)
487#define RB_PREV(name, x) name##_RB_PREV(x)
488#define RB_MIN(name, x) name##_RB_MINMAX(x, RB_NEGINF)
489#define RB_MAX(name, x) name##_RB_MINMAX(x, RB_INF)
490
491#define RB_FOREACH(x, name, head) \
492 for ((x) = RB_MIN(name, head); \
493 (x) != NULL; \
494 (x) = name##_RB_NEXT(x))
495
496#define RB_FOREACH_FROM(x, name, y) \
497 for ((x) = (y); \
498 ((x) != NULL) && ((y) = name##_RB_NEXT(x), (x) != NULL); \
499 (x) = (y))
500
501#define RB_FOREACH_SAFE(x, name, head, y) \
502 for ((x) = RB_MIN(name, head); \
503 ((x) != NULL) && ((y) = name##_RB_NEXT(x), (x) != NULL); \
504 (x) = (y))
505
506#define RB_FOREACH_REVERSE(x, name, head) \
507 for ((x) = RB_MAX(name, head); \
508 (x) != NULL; \
509 (x) = name##_RB_PREV(x))
510
511#define RB_FOREACH_REVERSE_FROM(x, name, y) \
512 for ((x) = (y); \
513 ((x) != NULL) && ((y) = name##_RB_PREV(x), (x) != NULL); \
514 (x) = (y))
515
516#define RB_FOREACH_REVERSE_SAFE(x, name, head, y) \
517 for ((x) = RB_MAX(name, head); \
518 ((x) != NULL) && ((y) = name##_RB_PREV(x), (x) != NULL); \
519 (x) = (y))
520
521#endif /* UV_TREE_H_ */