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memory/mozjemalloc/rb.h

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1 /******************************************************************************
2 *
3 * Copyright (C) 2008 Jason Evans <jasone@FreeBSD.org>.
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(s), this list of conditions and the following disclaimer
11 * unmodified other than the allowable addition of one or more
12 * copyright notices.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice(s), this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
16 * distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
19 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
25 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
26 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
27 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
28 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 *
30 ******************************************************************************
31 *
32 * cpp macro implementation of left-leaning red-black trees.
33 *
34 * Usage:
35 *
36 * (Optional.)
37 * #define SIZEOF_PTR ...
38 * #define SIZEOF_PTR_2POW ...
39 * #define RB_NO_C99_VARARRAYS
40 *
41 * (Optional, see assert(3).)
42 * #define NDEBUG
43 *
44 * (Required.)
45 * #include <assert.h>
46 * #include <rb.h>
47 * ...
48 *
49 * All operations are done non-recursively. Parent pointers are not used, and
50 * color bits are stored in the least significant bit of right-child pointers,
51 * thus making node linkage as compact as is possible for red-black trees.
52 *
53 * Some macros use a comparison function pointer, which is expected to have the
54 * following prototype:
55 *
56 * int (a_cmp *)(a_type *a_node, a_type *a_other);
57 * ^^^^^^
58 * or a_key
59 *
60 * Interpretation of comparision function return values:
61 *
62 * -1 : a_node < a_other
63 * 0 : a_node == a_other
64 * 1 : a_node > a_other
65 *
66 * In all cases, the a_node or a_key macro argument is the first argument to the
67 * comparison function, which makes it possible to write comparison functions
68 * that treat the first argument specially.
69 *
70 ******************************************************************************/
71
72 #ifndef RB_H_
73 #define RB_H_
74
75 #if 0
76 #include <sys/cdefs.h>
77 __FBSDID("$FreeBSD: head/lib/libc/stdlib/rb.h 178995 2008-05-14 18:33:13Z jasone $");
78 #endif
79
80 /* Node structure. */
81 #define rb_node(a_type) \
82 struct { \
83 a_type *rbn_left; \
84 a_type *rbn_right_red; \
85 }
86
87 /* Root structure. */
88 #define rb_tree(a_type) \
89 struct { \
90 a_type *rbt_root; \
91 a_type rbt_nil; \
92 }
93
94 /* Left accessors. */
95 #define rbp_left_get(a_type, a_field, a_node) \
96 ((a_node)->a_field.rbn_left)
97 #define rbp_left_set(a_type, a_field, a_node, a_left) do { \
98 (a_node)->a_field.rbn_left = a_left; \
99 } while (0)
100
101 /* Right accessors. */
102 #define rbp_right_get(a_type, a_field, a_node) \
103 ((a_type *) (((intptr_t) (a_node)->a_field.rbn_right_red) \
104 & ((ssize_t)-2)))
105 #define rbp_right_set(a_type, a_field, a_node, a_right) do { \
106 (a_node)->a_field.rbn_right_red = (a_type *) (((uintptr_t) a_right) \
107 | (((uintptr_t) (a_node)->a_field.rbn_right_red) & ((size_t)1))); \
108 } while (0)
109
110 /* Color accessors. */
111 #define rbp_red_get(a_type, a_field, a_node) \
112 ((bool) (((uintptr_t) (a_node)->a_field.rbn_right_red) \
113 & ((size_t)1)))
114 #define rbp_color_set(a_type, a_field, a_node, a_red) do { \
115 (a_node)->a_field.rbn_right_red = (a_type *) ((((intptr_t) \
116 (a_node)->a_field.rbn_right_red) & ((ssize_t)-2)) \
117 | ((ssize_t)a_red)); \
118 } while (0)
119 #define rbp_red_set(a_type, a_field, a_node) do { \
120 (a_node)->a_field.rbn_right_red = (a_type *) (((uintptr_t) \
121 (a_node)->a_field.rbn_right_red) | ((size_t)1)); \
122 } while (0)
123 #define rbp_black_set(a_type, a_field, a_node) do { \
124 (a_node)->a_field.rbn_right_red = (a_type *) (((intptr_t) \
125 (a_node)->a_field.rbn_right_red) & ((ssize_t)-2)); \
126 } while (0)
127
128 /* Node initializer. */
129 #define rbp_node_new(a_type, a_field, a_tree, a_node) do { \
130 rbp_left_set(a_type, a_field, (a_node), &(a_tree)->rbt_nil); \
131 rbp_right_set(a_type, a_field, (a_node), &(a_tree)->rbt_nil); \
132 rbp_red_set(a_type, a_field, (a_node)); \
133 } while (0)
134
135 /* Tree initializer. */
136 #define rb_new(a_type, a_field, a_tree) do { \
137 (a_tree)->rbt_root = &(a_tree)->rbt_nil; \
138 rbp_node_new(a_type, a_field, a_tree, &(a_tree)->rbt_nil); \
139 rbp_black_set(a_type, a_field, &(a_tree)->rbt_nil); \
140 } while (0)
141
142 /* Tree operations. */
143 #define rbp_black_height(a_type, a_field, a_tree, r_height) do { \
144 a_type *rbp_bh_t; \
145 for (rbp_bh_t = (a_tree)->rbt_root, (r_height) = 0; \
146 rbp_bh_t != &(a_tree)->rbt_nil; \
147 rbp_bh_t = rbp_left_get(a_type, a_field, rbp_bh_t)) { \
148 if (rbp_red_get(a_type, a_field, rbp_bh_t) == false) { \
149 (r_height)++; \
150 } \
151 } \
152 } while (0)
153
154 #define rbp_first(a_type, a_field, a_tree, a_root, r_node) do { \
155 for ((r_node) = (a_root); \
156 rbp_left_get(a_type, a_field, (r_node)) != &(a_tree)->rbt_nil; \
157 (r_node) = rbp_left_get(a_type, a_field, (r_node))) { \
158 } \
159 } while (0)
160
161 #define rbp_last(a_type, a_field, a_tree, a_root, r_node) do { \
162 for ((r_node) = (a_root); \
163 rbp_right_get(a_type, a_field, (r_node)) != &(a_tree)->rbt_nil; \
164 (r_node) = rbp_right_get(a_type, a_field, (r_node))) { \
165 } \
166 } while (0)
167
168 #define rbp_next(a_type, a_field, a_cmp, a_tree, a_node, r_node) do { \
169 if (rbp_right_get(a_type, a_field, (a_node)) \
170 != &(a_tree)->rbt_nil) { \
171 rbp_first(a_type, a_field, a_tree, rbp_right_get(a_type, \
172 a_field, (a_node)), (r_node)); \
173 } else { \
174 a_type *rbp_n_t = (a_tree)->rbt_root; \
175 assert(rbp_n_t != &(a_tree)->rbt_nil); \
176 (r_node) = &(a_tree)->rbt_nil; \
177 while (true) { \
178 int rbp_n_cmp = (a_cmp)((a_node), rbp_n_t); \
179 if (rbp_n_cmp < 0) { \
180 (r_node) = rbp_n_t; \
181 rbp_n_t = rbp_left_get(a_type, a_field, rbp_n_t); \
182 } else if (rbp_n_cmp > 0) { \
183 rbp_n_t = rbp_right_get(a_type, a_field, rbp_n_t); \
184 } else { \
185 break; \
186 } \
187 assert(rbp_n_t != &(a_tree)->rbt_nil); \
188 } \
189 } \
190 } while (0)
191
192 #define rbp_prev(a_type, a_field, a_cmp, a_tree, a_node, r_node) do { \
193 if (rbp_left_get(a_type, a_field, (a_node)) != &(a_tree)->rbt_nil) {\
194 rbp_last(a_type, a_field, a_tree, rbp_left_get(a_type, \
195 a_field, (a_node)), (r_node)); \
196 } else { \
197 a_type *rbp_p_t = (a_tree)->rbt_root; \
198 assert(rbp_p_t != &(a_tree)->rbt_nil); \
199 (r_node) = &(a_tree)->rbt_nil; \
200 while (true) { \
201 int rbp_p_cmp = (a_cmp)((a_node), rbp_p_t); \
202 if (rbp_p_cmp < 0) { \
203 rbp_p_t = rbp_left_get(a_type, a_field, rbp_p_t); \
204 } else if (rbp_p_cmp > 0) { \
205 (r_node) = rbp_p_t; \
206 rbp_p_t = rbp_right_get(a_type, a_field, rbp_p_t); \
207 } else { \
208 break; \
209 } \
210 assert(rbp_p_t != &(a_tree)->rbt_nil); \
211 } \
212 } \
213 } while (0)
214
215 #define rb_first(a_type, a_field, a_tree, r_node) do { \
216 rbp_first(a_type, a_field, a_tree, (a_tree)->rbt_root, (r_node)); \
217 if ((r_node) == &(a_tree)->rbt_nil) { \
218 (r_node) = NULL; \
219 } \
220 } while (0)
221
222 #define rb_last(a_type, a_field, a_tree, r_node) do { \
223 rbp_last(a_type, a_field, a_tree, (a_tree)->rbt_root, r_node); \
224 if ((r_node) == &(a_tree)->rbt_nil) { \
225 (r_node) = NULL; \
226 } \
227 } while (0)
228
229 #define rb_next(a_type, a_field, a_cmp, a_tree, a_node, r_node) do { \
230 rbp_next(a_type, a_field, a_cmp, a_tree, (a_node), (r_node)); \
231 if ((r_node) == &(a_tree)->rbt_nil) { \
232 (r_node) = NULL; \
233 } \
234 } while (0)
235
236 #define rb_prev(a_type, a_field, a_cmp, a_tree, a_node, r_node) do { \
237 rbp_prev(a_type, a_field, a_cmp, a_tree, (a_node), (r_node)); \
238 if ((r_node) == &(a_tree)->rbt_nil) { \
239 (r_node) = NULL; \
240 } \
241 } while (0)
242
243 #define rb_search(a_type, a_field, a_cmp, a_tree, a_key, r_node) do { \
244 int rbp_se_cmp; \
245 (r_node) = (a_tree)->rbt_root; \
246 while ((r_node) != &(a_tree)->rbt_nil \
247 && (rbp_se_cmp = (a_cmp)((a_key), (r_node))) != 0) { \
248 if (rbp_se_cmp < 0) { \
249 (r_node) = rbp_left_get(a_type, a_field, (r_node)); \
250 } else { \
251 (r_node) = rbp_right_get(a_type, a_field, (r_node)); \
252 } \
253 } \
254 if ((r_node) == &(a_tree)->rbt_nil) { \
255 (r_node) = NULL; \
256 } \
257 } while (0)
258
259 /*
260 * Find a match if it exists. Otherwise, find the next greater node, if one
261 * exists.
262 */
263 #define rb_nsearch(a_type, a_field, a_cmp, a_tree, a_key, r_node) do { \
264 a_type *rbp_ns_t = (a_tree)->rbt_root; \
265 (r_node) = NULL; \
266 while (rbp_ns_t != &(a_tree)->rbt_nil) { \
267 int rbp_ns_cmp = (a_cmp)((a_key), rbp_ns_t); \
268 if (rbp_ns_cmp < 0) { \
269 (r_node) = rbp_ns_t; \
270 rbp_ns_t = rbp_left_get(a_type, a_field, rbp_ns_t); \
271 } else if (rbp_ns_cmp > 0) { \
272 rbp_ns_t = rbp_right_get(a_type, a_field, rbp_ns_t); \
273 } else { \
274 (r_node) = rbp_ns_t; \
275 break; \
276 } \
277 } \
278 } while (0)
279
280 /*
281 * Find a match if it exists. Otherwise, find the previous lesser node, if one
282 * exists.
283 */
284 #define rb_psearch(a_type, a_field, a_cmp, a_tree, a_key, r_node) do { \
285 a_type *rbp_ps_t = (a_tree)->rbt_root; \
286 (r_node) = NULL; \
287 while (rbp_ps_t != &(a_tree)->rbt_nil) { \
288 int rbp_ps_cmp = (a_cmp)((a_key), rbp_ps_t); \
289 if (rbp_ps_cmp < 0) { \
290 rbp_ps_t = rbp_left_get(a_type, a_field, rbp_ps_t); \
291 } else if (rbp_ps_cmp > 0) { \
292 (r_node) = rbp_ps_t; \
293 rbp_ps_t = rbp_right_get(a_type, a_field, rbp_ps_t); \
294 } else { \
295 (r_node) = rbp_ps_t; \
296 break; \
297 } \
298 } \
299 } while (0)
300
301 #define rbp_rotate_left(a_type, a_field, a_node, r_node) do { \
302 (r_node) = rbp_right_get(a_type, a_field, (a_node)); \
303 rbp_right_set(a_type, a_field, (a_node), \
304 rbp_left_get(a_type, a_field, (r_node))); \
305 rbp_left_set(a_type, a_field, (r_node), (a_node)); \
306 } while (0)
307
308 #define rbp_rotate_right(a_type, a_field, a_node, r_node) do { \
309 (r_node) = rbp_left_get(a_type, a_field, (a_node)); \
310 rbp_left_set(a_type, a_field, (a_node), \
311 rbp_right_get(a_type, a_field, (r_node))); \
312 rbp_right_set(a_type, a_field, (r_node), (a_node)); \
313 } while (0)
314
315 #define rbp_lean_left(a_type, a_field, a_node, r_node) do { \
316 bool rbp_ll_red; \
317 rbp_rotate_left(a_type, a_field, (a_node), (r_node)); \
318 rbp_ll_red = rbp_red_get(a_type, a_field, (a_node)); \
319 rbp_color_set(a_type, a_field, (r_node), rbp_ll_red); \
320 rbp_red_set(a_type, a_field, (a_node)); \
321 } while (0)
322
323 #define rbp_lean_right(a_type, a_field, a_node, r_node) do { \
324 bool rbp_lr_red; \
325 rbp_rotate_right(a_type, a_field, (a_node), (r_node)); \
326 rbp_lr_red = rbp_red_get(a_type, a_field, (a_node)); \
327 rbp_color_set(a_type, a_field, (r_node), rbp_lr_red); \
328 rbp_red_set(a_type, a_field, (a_node)); \
329 } while (0)
330
331 #define rbp_move_red_left(a_type, a_field, a_node, r_node) do { \
332 a_type *rbp_mrl_t, *rbp_mrl_u; \
333 rbp_mrl_t = rbp_left_get(a_type, a_field, (a_node)); \
334 rbp_red_set(a_type, a_field, rbp_mrl_t); \
335 rbp_mrl_t = rbp_right_get(a_type, a_field, (a_node)); \
336 rbp_mrl_u = rbp_left_get(a_type, a_field, rbp_mrl_t); \
337 if (rbp_red_get(a_type, a_field, rbp_mrl_u)) { \
338 rbp_rotate_right(a_type, a_field, rbp_mrl_t, rbp_mrl_u); \
339 rbp_right_set(a_type, a_field, (a_node), rbp_mrl_u); \
340 rbp_rotate_left(a_type, a_field, (a_node), (r_node)); \
341 rbp_mrl_t = rbp_right_get(a_type, a_field, (a_node)); \
342 if (rbp_red_get(a_type, a_field, rbp_mrl_t)) { \
343 rbp_black_set(a_type, a_field, rbp_mrl_t); \
344 rbp_red_set(a_type, a_field, (a_node)); \
345 rbp_rotate_left(a_type, a_field, (a_node), rbp_mrl_t); \
346 rbp_left_set(a_type, a_field, (r_node), rbp_mrl_t); \
347 } else { \
348 rbp_black_set(a_type, a_field, (a_node)); \
349 } \
350 } else { \
351 rbp_red_set(a_type, a_field, (a_node)); \
352 rbp_rotate_left(a_type, a_field, (a_node), (r_node)); \
353 } \
354 } while (0)
355
356 #define rbp_move_red_right(a_type, a_field, a_node, r_node) do { \
357 a_type *rbp_mrr_t; \
358 rbp_mrr_t = rbp_left_get(a_type, a_field, (a_node)); \
359 if (rbp_red_get(a_type, a_field, rbp_mrr_t)) { \
360 a_type *rbp_mrr_u, *rbp_mrr_v; \
361 rbp_mrr_u = rbp_right_get(a_type, a_field, rbp_mrr_t); \
362 rbp_mrr_v = rbp_left_get(a_type, a_field, rbp_mrr_u); \
363 if (rbp_red_get(a_type, a_field, rbp_mrr_v)) { \
364 rbp_color_set(a_type, a_field, rbp_mrr_u, \
365 rbp_red_get(a_type, a_field, (a_node))); \
366 rbp_black_set(a_type, a_field, rbp_mrr_v); \
367 rbp_rotate_left(a_type, a_field, rbp_mrr_t, rbp_mrr_u); \
368 rbp_left_set(a_type, a_field, (a_node), rbp_mrr_u); \
369 rbp_rotate_right(a_type, a_field, (a_node), (r_node)); \
370 rbp_rotate_left(a_type, a_field, (a_node), rbp_mrr_t); \
371 rbp_right_set(a_type, a_field, (r_node), rbp_mrr_t); \
372 } else { \
373 rbp_color_set(a_type, a_field, rbp_mrr_t, \
374 rbp_red_get(a_type, a_field, (a_node))); \
375 rbp_red_set(a_type, a_field, rbp_mrr_u); \
376 rbp_rotate_right(a_type, a_field, (a_node), (r_node)); \
377 rbp_rotate_left(a_type, a_field, (a_node), rbp_mrr_t); \
378 rbp_right_set(a_type, a_field, (r_node), rbp_mrr_t); \
379 } \
380 rbp_red_set(a_type, a_field, (a_node)); \
381 } else { \
382 rbp_red_set(a_type, a_field, rbp_mrr_t); \
383 rbp_mrr_t = rbp_left_get(a_type, a_field, rbp_mrr_t); \
384 if (rbp_red_get(a_type, a_field, rbp_mrr_t)) { \
385 rbp_black_set(a_type, a_field, rbp_mrr_t); \
386 rbp_rotate_right(a_type, a_field, (a_node), (r_node)); \
387 rbp_rotate_left(a_type, a_field, (a_node), rbp_mrr_t); \
388 rbp_right_set(a_type, a_field, (r_node), rbp_mrr_t); \
389 } else { \
390 rbp_rotate_left(a_type, a_field, (a_node), (r_node)); \
391 } \
392 } \
393 } while (0)
394
395 #define rb_insert(a_type, a_field, a_cmp, a_tree, a_node) do { \
396 a_type rbp_i_s; \
397 a_type *rbp_i_g, *rbp_i_p, *rbp_i_c, *rbp_i_t, *rbp_i_u; \
398 int rbp_i_cmp = 0; \
399 rbp_i_g = &(a_tree)->rbt_nil; \
400 rbp_left_set(a_type, a_field, &rbp_i_s, (a_tree)->rbt_root); \
401 rbp_right_set(a_type, a_field, &rbp_i_s, &(a_tree)->rbt_nil); \
402 rbp_black_set(a_type, a_field, &rbp_i_s); \
403 rbp_i_p = &rbp_i_s; \
404 rbp_i_c = (a_tree)->rbt_root; \
405 /* Iteratively search down the tree for the insertion point, */\
406 /* splitting 4-nodes as they are encountered. At the end of each */\
407 /* iteration, rbp_i_g->rbp_i_p->rbp_i_c is a 3-level path down */\
408 /* the tree, assuming a sufficiently deep tree. */\
409 while (rbp_i_c != &(a_tree)->rbt_nil) { \
410 rbp_i_t = rbp_left_get(a_type, a_field, rbp_i_c); \
411 rbp_i_u = rbp_left_get(a_type, a_field, rbp_i_t); \
412 if (rbp_red_get(a_type, a_field, rbp_i_t) \
413 && rbp_red_get(a_type, a_field, rbp_i_u)) { \
414 /* rbp_i_c is the top of a logical 4-node, so split it. */\
415 /* This iteration does not move down the tree, due to the */\
416 /* disruptiveness of node splitting. */\
417 /* */\
418 /* Rotate right. */\
419 rbp_rotate_right(a_type, a_field, rbp_i_c, rbp_i_t); \
420 /* Pass red links up one level. */\
421 rbp_i_u = rbp_left_get(a_type, a_field, rbp_i_t); \
422 rbp_black_set(a_type, a_field, rbp_i_u); \
423 if (rbp_left_get(a_type, a_field, rbp_i_p) == rbp_i_c) { \
424 rbp_left_set(a_type, a_field, rbp_i_p, rbp_i_t); \
425 rbp_i_c = rbp_i_t; \
426 } else { \
427 /* rbp_i_c was the right child of rbp_i_p, so rotate */\
428 /* left in order to maintain the left-leaning */\
429 /* invariant. */\
430 assert(rbp_right_get(a_type, a_field, rbp_i_p) \
431 == rbp_i_c); \
432 rbp_right_set(a_type, a_field, rbp_i_p, rbp_i_t); \
433 rbp_lean_left(a_type, a_field, rbp_i_p, rbp_i_u); \
434 if (rbp_left_get(a_type, a_field, rbp_i_g) == rbp_i_p) {\
435 rbp_left_set(a_type, a_field, rbp_i_g, rbp_i_u); \
436 } else { \
437 assert(rbp_right_get(a_type, a_field, rbp_i_g) \
438 == rbp_i_p); \
439 rbp_right_set(a_type, a_field, rbp_i_g, rbp_i_u); \
440 } \
441 rbp_i_p = rbp_i_u; \
442 rbp_i_cmp = (a_cmp)((a_node), rbp_i_p); \
443 if (rbp_i_cmp < 0) { \
444 rbp_i_c = rbp_left_get(a_type, a_field, rbp_i_p); \
445 } else { \
446 assert(rbp_i_cmp > 0); \
447 rbp_i_c = rbp_right_get(a_type, a_field, rbp_i_p); \
448 } \
449 continue; \
450 } \
451 } \
452 rbp_i_g = rbp_i_p; \
453 rbp_i_p = rbp_i_c; \
454 rbp_i_cmp = (a_cmp)((a_node), rbp_i_c); \
455 if (rbp_i_cmp < 0) { \
456 rbp_i_c = rbp_left_get(a_type, a_field, rbp_i_c); \
457 } else { \
458 assert(rbp_i_cmp > 0); \
459 rbp_i_c = rbp_right_get(a_type, a_field, rbp_i_c); \
460 } \
461 } \
462 /* rbp_i_p now refers to the node under which to insert. */\
463 rbp_node_new(a_type, a_field, a_tree, (a_node)); \
464 if (rbp_i_cmp > 0) { \
465 rbp_right_set(a_type, a_field, rbp_i_p, (a_node)); \
466 rbp_lean_left(a_type, a_field, rbp_i_p, rbp_i_t); \
467 if (rbp_left_get(a_type, a_field, rbp_i_g) == rbp_i_p) { \
468 rbp_left_set(a_type, a_field, rbp_i_g, rbp_i_t); \
469 } else if (rbp_right_get(a_type, a_field, rbp_i_g) == rbp_i_p) {\
470 rbp_right_set(a_type, a_field, rbp_i_g, rbp_i_t); \
471 } \
472 } else { \
473 rbp_left_set(a_type, a_field, rbp_i_p, (a_node)); \
474 } \
475 /* Update the root and make sure that it is black. */\
476 (a_tree)->rbt_root = rbp_left_get(a_type, a_field, &rbp_i_s); \
477 rbp_black_set(a_type, a_field, (a_tree)->rbt_root); \
478 } while (0)
479
480 #define rb_remove(a_type, a_field, a_cmp, a_tree, a_node) do { \
481 a_type rbp_r_s; \
482 a_type *rbp_r_p, *rbp_r_c, *rbp_r_xp, *rbp_r_t, *rbp_r_u; \
483 int rbp_r_cmp; \
484 rbp_left_set(a_type, a_field, &rbp_r_s, (a_tree)->rbt_root); \
485 rbp_right_set(a_type, a_field, &rbp_r_s, &(a_tree)->rbt_nil); \
486 rbp_black_set(a_type, a_field, &rbp_r_s); \
487 rbp_r_p = &rbp_r_s; \
488 rbp_r_c = (a_tree)->rbt_root; \
489 rbp_r_xp = &(a_tree)->rbt_nil; \
490 /* Iterate down the tree, but always transform 2-nodes to 3- or */\
491 /* 4-nodes in order to maintain the invariant that the current */\
492 /* node is not a 2-node. This allows simple deletion once a leaf */\
493 /* is reached. Handle the root specially though, since there may */\
494 /* be no way to convert it from a 2-node to a 3-node. */\
495 rbp_r_cmp = (a_cmp)((a_node), rbp_r_c); \
496 if (rbp_r_cmp < 0) { \
497 rbp_r_t = rbp_left_get(a_type, a_field, rbp_r_c); \
498 rbp_r_u = rbp_left_get(a_type, a_field, rbp_r_t); \
499 if (rbp_red_get(a_type, a_field, rbp_r_t) == false \
500 && rbp_red_get(a_type, a_field, rbp_r_u) == false) { \
501 /* Apply standard transform to prepare for left move. */\
502 rbp_move_red_left(a_type, a_field, rbp_r_c, rbp_r_t); \
503 rbp_black_set(a_type, a_field, rbp_r_t); \
504 rbp_left_set(a_type, a_field, rbp_r_p, rbp_r_t); \
505 rbp_r_c = rbp_r_t; \
506 } else { \
507 /* Move left. */\
508 rbp_r_p = rbp_r_c; \
509 rbp_r_c = rbp_left_get(a_type, a_field, rbp_r_c); \
510 } \
511 } else { \
512 if (rbp_r_cmp == 0) { \
513 assert((a_node) == rbp_r_c); \
514 if (rbp_right_get(a_type, a_field, rbp_r_c) \
515 == &(a_tree)->rbt_nil) { \
516 /* Delete root node (which is also a leaf node). */\
517 if (rbp_left_get(a_type, a_field, rbp_r_c) \
518 != &(a_tree)->rbt_nil) { \
519 rbp_lean_right(a_type, a_field, rbp_r_c, rbp_r_t); \
520 rbp_right_set(a_type, a_field, rbp_r_t, \
521 &(a_tree)->rbt_nil); \
522 } else { \
523 rbp_r_t = &(a_tree)->rbt_nil; \
524 } \
525 rbp_left_set(a_type, a_field, rbp_r_p, rbp_r_t); \
526 } else { \
527 /* This is the node we want to delete, but we will */\
528 /* instead swap it with its successor and delete the */\
529 /* successor. Record enough information to do the */\
530 /* swap later. rbp_r_xp is the a_node's parent. */\
531 rbp_r_xp = rbp_r_p; \
532 rbp_r_cmp = 1; /* Note that deletion is incomplete. */\
533 } \
534 } \
535 if (rbp_r_cmp == 1) { \
536 if (rbp_red_get(a_type, a_field, rbp_left_get(a_type, \
537 a_field, rbp_right_get(a_type, a_field, rbp_r_c))) \
538 == false) { \
539 rbp_r_t = rbp_left_get(a_type, a_field, rbp_r_c); \
540 if (rbp_red_get(a_type, a_field, rbp_r_t)) { \
541 /* Standard transform. */\
542 rbp_move_red_right(a_type, a_field, rbp_r_c, \
543 rbp_r_t); \
544 } else { \
545 /* Root-specific transform. */\
546 rbp_red_set(a_type, a_field, rbp_r_c); \
547 rbp_r_u = rbp_left_get(a_type, a_field, rbp_r_t); \
548 if (rbp_red_get(a_type, a_field, rbp_r_u)) { \
549 rbp_black_set(a_type, a_field, rbp_r_u); \
550 rbp_rotate_right(a_type, a_field, rbp_r_c, \
551 rbp_r_t); \
552 rbp_rotate_left(a_type, a_field, rbp_r_c, \
553 rbp_r_u); \
554 rbp_right_set(a_type, a_field, rbp_r_t, \
555 rbp_r_u); \
556 } else { \
557 rbp_red_set(a_type, a_field, rbp_r_t); \
558 rbp_rotate_left(a_type, a_field, rbp_r_c, \
559 rbp_r_t); \
560 } \
561 } \
562 rbp_left_set(a_type, a_field, rbp_r_p, rbp_r_t); \
563 rbp_r_c = rbp_r_t; \
564 } else { \
565 /* Move right. */\
566 rbp_r_p = rbp_r_c; \
567 rbp_r_c = rbp_right_get(a_type, a_field, rbp_r_c); \
568 } \
569 } \
570 } \
571 if (rbp_r_cmp != 0) { \
572 while (true) { \
573 assert(rbp_r_p != &(a_tree)->rbt_nil); \
574 rbp_r_cmp = (a_cmp)((a_node), rbp_r_c); \
575 if (rbp_r_cmp < 0) { \
576 rbp_r_t = rbp_left_get(a_type, a_field, rbp_r_c); \
577 if (rbp_r_t == &(a_tree)->rbt_nil) { \
578 /* rbp_r_c now refers to the successor node to */\
579 /* relocate, and rbp_r_xp/a_node refer to the */\
580 /* context for the relocation. */\
581 if (rbp_left_get(a_type, a_field, rbp_r_xp) \
582 == (a_node)) { \
583 rbp_left_set(a_type, a_field, rbp_r_xp, \
584 rbp_r_c); \
585 } else { \
586 assert(rbp_right_get(a_type, a_field, \
587 rbp_r_xp) == (a_node)); \
588 rbp_right_set(a_type, a_field, rbp_r_xp, \
589 rbp_r_c); \
590 } \
591 rbp_left_set(a_type, a_field, rbp_r_c, \
592 rbp_left_get(a_type, a_field, (a_node))); \
593 rbp_right_set(a_type, a_field, rbp_r_c, \
594 rbp_right_get(a_type, a_field, (a_node))); \
595 rbp_color_set(a_type, a_field, rbp_r_c, \
596 rbp_red_get(a_type, a_field, (a_node))); \
597 if (rbp_left_get(a_type, a_field, rbp_r_p) \
598 == rbp_r_c) { \
599 rbp_left_set(a_type, a_field, rbp_r_p, \
600 &(a_tree)->rbt_nil); \
601 } else { \
602 assert(rbp_right_get(a_type, a_field, rbp_r_p) \
603 == rbp_r_c); \
604 rbp_right_set(a_type, a_field, rbp_r_p, \
605 &(a_tree)->rbt_nil); \
606 } \
607 break; \
608 } \
609 rbp_r_u = rbp_left_get(a_type, a_field, rbp_r_t); \
610 if (rbp_red_get(a_type, a_field, rbp_r_t) == false \
611 && rbp_red_get(a_type, a_field, rbp_r_u) == false) { \
612 rbp_move_red_left(a_type, a_field, rbp_r_c, \
613 rbp_r_t); \
614 if (rbp_left_get(a_type, a_field, rbp_r_p) \
615 == rbp_r_c) { \
616 rbp_left_set(a_type, a_field, rbp_r_p, rbp_r_t);\
617 } else { \
618 rbp_right_set(a_type, a_field, rbp_r_p, \
619 rbp_r_t); \
620 } \
621 rbp_r_c = rbp_r_t; \
622 } else { \
623 rbp_r_p = rbp_r_c; \
624 rbp_r_c = rbp_left_get(a_type, a_field, rbp_r_c); \
625 } \
626 } else { \
627 /* Check whether to delete this node (it has to be */\
628 /* the correct node and a leaf node). */\
629 if (rbp_r_cmp == 0) { \
630 assert((a_node) == rbp_r_c); \
631 if (rbp_right_get(a_type, a_field, rbp_r_c) \
632 == &(a_tree)->rbt_nil) { \
633 /* Delete leaf node. */\
634 if (rbp_left_get(a_type, a_field, rbp_r_c) \
635 != &(a_tree)->rbt_nil) { \
636 rbp_lean_right(a_type, a_field, rbp_r_c, \
637 rbp_r_t); \
638 rbp_right_set(a_type, a_field, rbp_r_t, \
639 &(a_tree)->rbt_nil); \
640 } else { \
641 rbp_r_t = &(a_tree)->rbt_nil; \
642 } \
643 if (rbp_left_get(a_type, a_field, rbp_r_p) \
644 == rbp_r_c) { \
645 rbp_left_set(a_type, a_field, rbp_r_p, \
646 rbp_r_t); \
647 } else { \
648 rbp_right_set(a_type, a_field, rbp_r_p, \
649 rbp_r_t); \
650 } \
651 break; \
652 } else { \
653 /* This is the node we want to delete, but we */\
654 /* will instead swap it with its successor */\
655 /* and delete the successor. Record enough */\
656 /* information to do the swap later. */\
657 /* rbp_r_xp is a_node's parent. */\
658 rbp_r_xp = rbp_r_p; \
659 } \
660 } \
661 rbp_r_t = rbp_right_get(a_type, a_field, rbp_r_c); \
662 rbp_r_u = rbp_left_get(a_type, a_field, rbp_r_t); \
663 if (rbp_red_get(a_type, a_field, rbp_r_u) == false) { \
664 rbp_move_red_right(a_type, a_field, rbp_r_c, \
665 rbp_r_t); \
666 if (rbp_left_get(a_type, a_field, rbp_r_p) \
667 == rbp_r_c) { \
668 rbp_left_set(a_type, a_field, rbp_r_p, rbp_r_t);\
669 } else { \
670 rbp_right_set(a_type, a_field, rbp_r_p, \
671 rbp_r_t); \
672 } \
673 rbp_r_c = rbp_r_t; \
674 } else { \
675 rbp_r_p = rbp_r_c; \
676 rbp_r_c = rbp_right_get(a_type, a_field, rbp_r_c); \
677 } \
678 } \
679 } \
680 } \
681 /* Update root. */\
682 (a_tree)->rbt_root = rbp_left_get(a_type, a_field, &rbp_r_s); \
683 } while (0)
684
685 /*
686 * The rb_wrap() macro provides a convenient way to wrap functions around the
687 * cpp macros. The main benefits of wrapping are that 1) repeated macro
688 * expansion can cause code bloat, especially for rb_{insert,remove)(), and
689 * 2) type, linkage, comparison functions, etc. need not be specified at every
690 * call point.
691 */
692
693 #define rb_wrap(a_attr, a_prefix, a_tree_type, a_type, a_field, a_cmp) \
694 a_attr void \
695 a_prefix##new(a_tree_type *tree) { \
696 rb_new(a_type, a_field, tree); \
697 } \
698 a_attr a_type * \
699 a_prefix##first(a_tree_type *tree) { \
700 a_type *ret; \
701 rb_first(a_type, a_field, tree, ret); \
702 return (ret); \
703 } \
704 a_attr a_type * \
705 a_prefix##last(a_tree_type *tree) { \
706 a_type *ret; \
707 rb_last(a_type, a_field, tree, ret); \
708 return (ret); \
709 } \
710 a_attr a_type * \
711 a_prefix##next(a_tree_type *tree, a_type *node) { \
712 a_type *ret; \
713 rb_next(a_type, a_field, a_cmp, tree, node, ret); \
714 return (ret); \
715 } \
716 a_attr a_type * \
717 a_prefix##prev(a_tree_type *tree, a_type *node) { \
718 a_type *ret; \
719 rb_prev(a_type, a_field, a_cmp, tree, node, ret); \
720 return (ret); \
721 } \
722 a_attr a_type * \
723 a_prefix##search(a_tree_type *tree, a_type *key) { \
724 a_type *ret; \
725 rb_search(a_type, a_field, a_cmp, tree, key, ret); \
726 return (ret); \
727 } \
728 a_attr a_type * \
729 a_prefix##nsearch(a_tree_type *tree, a_type *key) { \
730 a_type *ret; \
731 rb_nsearch(a_type, a_field, a_cmp, tree, key, ret); \
732 return (ret); \
733 } \
734 a_attr a_type * \
735 a_prefix##psearch(a_tree_type *tree, a_type *key) { \
736 a_type *ret; \
737 rb_psearch(a_type, a_field, a_cmp, tree, key, ret); \
738 return (ret); \
739 } \
740 a_attr void \
741 a_prefix##insert(a_tree_type *tree, a_type *node) { \
742 rb_insert(a_type, a_field, a_cmp, tree, node); \
743 } \
744 a_attr void \
745 a_prefix##remove(a_tree_type *tree, a_type *node) { \
746 rb_remove(a_type, a_field, a_cmp, tree, node); \
747 }
748
749 /*
750 * The iterators simulate recursion via an array of pointers that store the
751 * current path. This is critical to performance, since a series of calls to
752 * rb_{next,prev}() would require time proportional to (n lg n), whereas this
753 * implementation only requires time proportional to (n).
754 *
755 * Since the iterators cache a path down the tree, any tree modification may
756 * cause the cached path to become invalid. In order to continue iteration,
757 * use something like the following sequence:
758 *
759 * {
760 * a_type *node, *tnode;
761 *
762 * rb_foreach_begin(a_type, a_field, a_tree, node) {
763 * ...
764 * rb_next(a_type, a_field, a_cmp, a_tree, node, tnode);
765 * rb_remove(a_type, a_field, a_cmp, a_tree, node);
766 * rb_foreach_next(a_type, a_field, a_cmp, a_tree, tnode);
767 * ...
768 * } rb_foreach_end(a_type, a_field, a_tree, node)
769 * }
770 *
771 * Note that this idiom is not advised if every iteration modifies the tree,
772 * since in that case there is no algorithmic complexity improvement over a
773 * series of rb_{next,prev}() calls, thus making the setup overhead wasted
774 * effort.
775 */
776
777 #ifdef RB_NO_C99_VARARRAYS
778 /*
779 * Avoid using variable-length arrays, at the cost of using more stack space.
780 * Size the path arrays such that they are always large enough, even if a
781 * tree consumes all of memory. Since each node must contain a minimum of
782 * two pointers, there can never be more nodes than:
783 *
784 * 1 << ((SIZEOF_PTR<<3) - (SIZEOF_PTR_2POW+1))
785 *
786 * Since the depth of a tree is limited to 3*lg(#nodes), the maximum depth
787 * is:
788 *
789 * (3 * ((SIZEOF_PTR<<3) - (SIZEOF_PTR_2POW+1)))
790 *
791 * This works out to a maximum depth of 87 and 180 for 32- and 64-bit
792 * systems, respectively (approximatly 348 and 1440 bytes, respectively).
793 */
794 # define rbp_compute_f_height(a_type, a_field, a_tree)
795 # define rbp_f_height (3 * ((SIZEOF_PTR<<3) - (SIZEOF_PTR_2POW+1)))
796 # define rbp_compute_fr_height(a_type, a_field, a_tree)
797 # define rbp_fr_height (3 * ((SIZEOF_PTR<<3) - (SIZEOF_PTR_2POW+1)))
798 #else
799 # define rbp_compute_f_height(a_type, a_field, a_tree) \
800 /* Compute the maximum possible tree depth (3X the black height). */\
801 unsigned rbp_f_height; \
802 rbp_black_height(a_type, a_field, a_tree, rbp_f_height); \
803 rbp_f_height *= 3;
804 # define rbp_compute_fr_height(a_type, a_field, a_tree) \
805 /* Compute the maximum possible tree depth (3X the black height). */\
806 unsigned rbp_fr_height; \
807 rbp_black_height(a_type, a_field, a_tree, rbp_fr_height); \
808 rbp_fr_height *= 3;
809 #endif
810
811 #define rb_foreach_begin(a_type, a_field, a_tree, a_var) { \
812 rbp_compute_f_height(a_type, a_field, a_tree) \
813 { \
814 /* Initialize the path to contain the left spine. */\
815 a_type *rbp_f_path[rbp_f_height]; \
816 a_type *rbp_f_node; \
817 bool rbp_f_synced = false; \
818 unsigned rbp_f_depth = 0; \
819 if ((a_tree)->rbt_root != &(a_tree)->rbt_nil) { \
820 rbp_f_path[rbp_f_depth] = (a_tree)->rbt_root; \
821 rbp_f_depth++; \
822 while ((rbp_f_node = rbp_left_get(a_type, a_field, \
823 rbp_f_path[rbp_f_depth-1])) != &(a_tree)->rbt_nil) { \
824 rbp_f_path[rbp_f_depth] = rbp_f_node; \
825 rbp_f_depth++; \
826 } \
827 } \
828 /* While the path is non-empty, iterate. */\
829 while (rbp_f_depth > 0) { \
830 (a_var) = rbp_f_path[rbp_f_depth-1];
831
832 /* Only use if modifying the tree during iteration. */
833 #define rb_foreach_next(a_type, a_field, a_cmp, a_tree, a_node) \
834 /* Re-initialize the path to contain the path to a_node. */\
835 rbp_f_depth = 0; \
836 if (a_node != NULL) { \
837 if ((a_tree)->rbt_root != &(a_tree)->rbt_nil) { \
838 rbp_f_path[rbp_f_depth] = (a_tree)->rbt_root; \
839 rbp_f_depth++; \
840 rbp_f_node = rbp_f_path[0]; \
841 while (true) { \
842 int rbp_f_cmp = (a_cmp)((a_node), \
843 rbp_f_path[rbp_f_depth-1]); \
844 if (rbp_f_cmp < 0) { \
845 rbp_f_node = rbp_left_get(a_type, a_field, \
846 rbp_f_path[rbp_f_depth-1]); \
847 } else if (rbp_f_cmp > 0) { \
848 rbp_f_node = rbp_right_get(a_type, a_field, \
849 rbp_f_path[rbp_f_depth-1]); \
850 } else { \
851 break; \
852 } \
853 assert(rbp_f_node != &(a_tree)->rbt_nil); \
854 rbp_f_path[rbp_f_depth] = rbp_f_node; \
855 rbp_f_depth++; \
856 } \
857 } \
858 } \
859 rbp_f_synced = true;
860
861 #define rb_foreach_end(a_type, a_field, a_tree, a_var) \
862 if (rbp_f_synced) { \
863 rbp_f_synced = false; \
864 continue; \
865 } \
866 /* Find the successor. */\
867 if ((rbp_f_node = rbp_right_get(a_type, a_field, \
868 rbp_f_path[rbp_f_depth-1])) != &(a_tree)->rbt_nil) { \
869 /* The successor is the left-most node in the right */\
870 /* subtree. */\
871 rbp_f_path[rbp_f_depth] = rbp_f_node; \
872 rbp_f_depth++; \
873 while ((rbp_f_node = rbp_left_get(a_type, a_field, \
874 rbp_f_path[rbp_f_depth-1])) != &(a_tree)->rbt_nil) { \
875 rbp_f_path[rbp_f_depth] = rbp_f_node; \
876 rbp_f_depth++; \
877 } \
878 } else { \
879 /* The successor is above the current node. Unwind */\
880 /* until a left-leaning edge is removed from the */\
881 /* path, or the path is empty. */\
882 for (rbp_f_depth--; rbp_f_depth > 0; rbp_f_depth--) { \
883 if (rbp_left_get(a_type, a_field, \
884 rbp_f_path[rbp_f_depth-1]) \
885 == rbp_f_path[rbp_f_depth]) { \
886 break; \
887 } \
888 } \
889 } \
890 } \
891 } \
892 }
893
894 #define rb_foreach_reverse_begin(a_type, a_field, a_tree, a_var) { \
895 rbp_compute_fr_height(a_type, a_field, a_tree) \
896 { \
897 /* Initialize the path to contain the right spine. */\
898 a_type *rbp_fr_path[rbp_fr_height]; \
899 a_type *rbp_fr_node; \
900 bool rbp_fr_synced = false; \
901 unsigned rbp_fr_depth = 0; \
902 if ((a_tree)->rbt_root != &(a_tree)->rbt_nil) { \
903 rbp_fr_path[rbp_fr_depth] = (a_tree)->rbt_root; \
904 rbp_fr_depth++; \
905 while ((rbp_fr_node = rbp_right_get(a_type, a_field, \
906 rbp_fr_path[rbp_fr_depth-1])) != &(a_tree)->rbt_nil) { \
907 rbp_fr_path[rbp_fr_depth] = rbp_fr_node; \
908 rbp_fr_depth++; \
909 } \
910 } \
911 /* While the path is non-empty, iterate. */\
912 while (rbp_fr_depth > 0) { \
913 (a_var) = rbp_fr_path[rbp_fr_depth-1];
914
915 /* Only use if modifying the tree during iteration. */
916 #define rb_foreach_reverse_prev(a_type, a_field, a_cmp, a_tree, a_node) \
917 /* Re-initialize the path to contain the path to a_node. */\
918 rbp_fr_depth = 0; \
919 if (a_node != NULL) { \
920 if ((a_tree)->rbt_root != &(a_tree)->rbt_nil) { \
921 rbp_fr_path[rbp_fr_depth] = (a_tree)->rbt_root; \
922 rbp_fr_depth++; \
923 rbp_fr_node = rbp_fr_path[0]; \
924 while (true) { \
925 int rbp_fr_cmp = (a_cmp)((a_node), \
926 rbp_fr_path[rbp_fr_depth-1]); \
927 if (rbp_fr_cmp < 0) { \
928 rbp_fr_node = rbp_left_get(a_type, a_field, \
929 rbp_fr_path[rbp_fr_depth-1]); \
930 } else if (rbp_fr_cmp > 0) { \
931 rbp_fr_node = rbp_right_get(a_type, a_field,\
932 rbp_fr_path[rbp_fr_depth-1]); \
933 } else { \
934 break; \
935 } \
936 assert(rbp_fr_node != &(a_tree)->rbt_nil); \
937 rbp_fr_path[rbp_fr_depth] = rbp_fr_node; \
938 rbp_fr_depth++; \
939 } \
940 } \
941 } \
942 rbp_fr_synced = true;
943
944 #define rb_foreach_reverse_end(a_type, a_field, a_tree, a_var) \
945 if (rbp_fr_synced) { \
946 rbp_fr_synced = false; \
947 continue; \
948 } \
949 if (rbp_fr_depth == 0) { \
950 /* rb_foreach_reverse_sync() was called with a NULL */\
951 /* a_node. */\
952 break; \
953 } \
954 /* Find the predecessor. */\
955 if ((rbp_fr_node = rbp_left_get(a_type, a_field, \
956 rbp_fr_path[rbp_fr_depth-1])) != &(a_tree)->rbt_nil) { \
957 /* The predecessor is the right-most node in the left */\
958 /* subtree. */\
959 rbp_fr_path[rbp_fr_depth] = rbp_fr_node; \
960 rbp_fr_depth++; \
961 while ((rbp_fr_node = rbp_right_get(a_type, a_field, \
962 rbp_fr_path[rbp_fr_depth-1])) != &(a_tree)->rbt_nil) {\
963 rbp_fr_path[rbp_fr_depth] = rbp_fr_node; \
964 rbp_fr_depth++; \
965 } \
966 } else { \
967 /* The predecessor is above the current node. Unwind */\
968 /* until a right-leaning edge is removed from the */\
969 /* path, or the path is empty. */\
970 for (rbp_fr_depth--; rbp_fr_depth > 0; rbp_fr_depth--) {\
971 if (rbp_right_get(a_type, a_field, \
972 rbp_fr_path[rbp_fr_depth-1]) \
973 == rbp_fr_path[rbp_fr_depth]) { \
974 break; \
975 } \
976 } \
977 } \
978 } \
979 } \
980 }
981
982 #endif /* RB_H_ */

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