Coverage Report

Created: 2025-07-11 06:57

/src/libevent/compat/sys/tree.h
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Source (jump to first uncovered line)
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
#ifndef _SYS_TREE_H_
28
#define _SYS_TREE_H_
29
30
/*
31
 * This file defines data structures for different types of trees:
32
 * splay trees and red-black trees.
33
 *
34
 * A splay tree is a self-organizing data structure.  Every operation
35
 * on the tree causes a splay to happen.  The splay moves the requested
36
 * node to the root of the tree and partly rebalances it.
37
 *
38
 * This has the benefit that request locality causes faster lookups as
39
 * the requested nodes move to the top of the tree.  On the other hand,
40
 * every lookup causes memory writes.
41
 *
42
 * The Balance Theorem bounds the total access time for m operations
43
 * and n inserts on an initially empty tree as O((m + n)lg n).  The
44
 * amortized cost for a sequence of m accesses to a splay tree is O(lg n);
45
 *
46
 * A red-black tree is a binary search tree with the node color as an
47
 * extra attribute.  It fulfills a set of conditions:
48
 *  - every search path from the root to a leaf consists of the
49
 *    same number of black nodes,
50
 *  - each red node (except for the root) has a black parent,
51
 *  - each leaf node is black.
52
 *
53
 * Every operation on a red-black tree is bounded as O(lg n).
54
 * The maximum height of a red-black tree is 2lg (n+1).
55
 */
56
57
#define SPLAY_HEAD(name, type)            \
58
struct name {               \
59
  struct type *sph_root; /* root of the tree */     \
60
}
61
62
#define SPLAY_INITIALIZER(root)           \
63
  { NULL }
64
65
0
#define SPLAY_INIT(root) do {           \
66
0
  (root)->sph_root = NULL;          \
67
0
} while (0)
68
69
#define SPLAY_ENTRY(type)           \
70
struct {                \
71
  struct type *spe_left; /* left element */     \
72
  struct type *spe_right; /* right element */     \
73
}
74
75
0
#define SPLAY_LEFT(elm, field)    (elm)->field.spe_left
76
0
#define SPLAY_RIGHT(elm, field)   (elm)->field.spe_right
77
0
#define SPLAY_ROOT(head)    (head)->sph_root
78
0
#define SPLAY_EMPTY(head)   (SPLAY_ROOT(head) == NULL)
79
80
/* SPLAY_ROTATE_{LEFT,RIGHT} expect that tmp hold SPLAY_{RIGHT,LEFT} */
81
0
#define SPLAY_ROTATE_RIGHT(head, tmp, field) do {     \
82
0
  SPLAY_LEFT((head)->sph_root, field) = SPLAY_RIGHT(tmp, field); \
83
0
  SPLAY_RIGHT(tmp, field) = (head)->sph_root;      \
84
0
  (head)->sph_root = tmp;           \
85
0
} while (0)
86
  
87
0
#define SPLAY_ROTATE_LEFT(head, tmp, field) do {     \
88
0
  SPLAY_RIGHT((head)->sph_root, field) = SPLAY_LEFT(tmp, field); \
89
0
  SPLAY_LEFT(tmp, field) = (head)->sph_root;      \
90
0
  (head)->sph_root = tmp;           \
91
0
} while (0)
92
93
0
#define SPLAY_LINKLEFT(head, tmp, field) do {       \
94
0
  SPLAY_LEFT(tmp, field) = (head)->sph_root;      \
95
0
  tmp = (head)->sph_root;           \
96
0
  (head)->sph_root = SPLAY_LEFT((head)->sph_root, field);    \
97
0
} while (0)
98
99
0
#define SPLAY_LINKRIGHT(head, tmp, field) do {       \
100
0
  SPLAY_RIGHT(tmp, field) = (head)->sph_root;      \
101
0
  tmp = (head)->sph_root;           \
102
0
  (head)->sph_root = SPLAY_RIGHT((head)->sph_root, field);  \
103
0
} while (0)
104
105
0
#define SPLAY_ASSEMBLE(head, node, left, right, field) do {   \
106
0
  SPLAY_RIGHT(left, field) = SPLAY_LEFT((head)->sph_root, field);  \
107
0
  SPLAY_LEFT(right, field) = SPLAY_RIGHT((head)->sph_root, field);\
108
0
  SPLAY_LEFT((head)->sph_root, field) = SPLAY_RIGHT(node, field);  \
109
0
  SPLAY_RIGHT((head)->sph_root, field) = SPLAY_LEFT(node, field);  \
110
0
} while (0)
111
112
/* Generates prototypes and inline functions */
113
114
#define SPLAY_PROTOTYPE(name, type, field, cmp)       \
115
void name##_SPLAY(struct name *, struct type *);      \
116
void name##_SPLAY_MINMAX(struct name *, int);       \
117
struct type *name##_SPLAY_INSERT(struct name *, struct type *);   \
118
struct type *name##_SPLAY_REMOVE(struct name *, struct type *);   \
119
                  \
120
/* Finds the node with the same key as elm */       \
121
static __inline struct type *           \
122
0
name##_SPLAY_FIND(struct name *head, struct type *elm)      \
123
0
{                 \
124
0
  if (SPLAY_EMPTY(head))           \
125
0
    return(NULL);           \
126
0
  name##_SPLAY(head, elm);          \
127
0
  if ((cmp)(elm, (head)->sph_root) == 0)       \
128
0
    return (head->sph_root);       \
129
0
  return (NULL);             \
130
0
}                  \
131
                  \
132
static __inline struct type *           \
133
0
name##_SPLAY_NEXT(struct name *head, struct type *elm)      \
134
0
{                 \
135
0
  name##_SPLAY(head, elm);          \
136
0
  if (SPLAY_RIGHT(elm, field) != NULL) {        \
137
0
    elm = SPLAY_RIGHT(elm, field);        \
138
0
    while (SPLAY_LEFT(elm, field) != NULL) {    \
139
0
      elm = SPLAY_LEFT(elm, field);     \
140
0
    }             \
141
0
  } else                \
142
0
    elm = NULL;           \
143
0
  return (elm);             \
144
0
}                  \
145
                  \
146
static __inline struct type *           \
147
0
name##_SPLAY_MIN_MAX(struct name *head, int val)      \
148
0
{                 \
149
0
  name##_SPLAY_MINMAX(head, val);         \
150
0
        return (SPLAY_ROOT(head));          \
151
0
}
152
153
/* Main splay operation.
154
 * Moves node close to the key of elm to top
155
 */
156
#define SPLAY_GENERATE(name, type, field, cmp)        \
157
struct type *               \
158
0
name##_SPLAY_INSERT(struct name *head, struct type *elm)    \
159
0
{                 \
160
0
    if (SPLAY_EMPTY(head)) {           \
161
0
      SPLAY_LEFT(elm, field) = SPLAY_RIGHT(elm, field) = NULL;  \
162
0
    } else {               \
163
0
      int __comp;             \
164
0
      name##_SPLAY(head, elm);          \
165
0
      __comp = (cmp)(elm, (head)->sph_root);      \
166
0
      if(__comp < 0) {           \
167
0
        SPLAY_LEFT(elm, field) = SPLAY_LEFT((head)->sph_root, field);\
168
0
        SPLAY_RIGHT(elm, field) = (head)->sph_root;    \
169
0
        SPLAY_LEFT((head)->sph_root, field) = NULL;   \
170
0
      } else if (__comp > 0) {         \
171
0
        SPLAY_RIGHT(elm, field) = SPLAY_RIGHT((head)->sph_root, field);\
172
0
        SPLAY_LEFT(elm, field) = (head)->sph_root;    \
173
0
        SPLAY_RIGHT((head)->sph_root, field) = NULL; \
174
0
      } else              \
175
0
        return ((head)->sph_root);       \
176
0
    }                 \
177
0
    (head)->sph_root = (elm);           \
178
0
    return (NULL);             \
179
0
}                  \
180
                  \
181
struct type *               \
182
0
name##_SPLAY_REMOVE(struct name *head, struct type *elm)    \
183
0
{                 \
184
0
  struct type *__tmp;           \
185
0
  if (SPLAY_EMPTY(head))           \
186
0
    return (NULL);           \
187
0
  name##_SPLAY(head, elm);          \
188
0
  if ((cmp)(elm, (head)->sph_root) == 0) {     \
189
0
    if (SPLAY_LEFT((head)->sph_root, field) == NULL) { \
190
0
      (head)->sph_root = SPLAY_RIGHT((head)->sph_root, field);\
191
0
    } else {           \
192
0
      __tmp = SPLAY_RIGHT((head)->sph_root, field);  \
193
0
      (head)->sph_root = SPLAY_LEFT((head)->sph_root, field);\
194
0
      name##_SPLAY(head, elm);      \
195
0
      SPLAY_RIGHT((head)->sph_root, field) = __tmp;  \
196
0
    }             \
197
0
    return (elm);           \
198
0
  }               \
199
0
  return (NULL);             \
200
0
}                  \
201
                  \
202
void                  \
203
0
name##_SPLAY(struct name *head, struct type *elm)     \
204
0
{                 \
205
0
  struct type __node, *__left, *__right, *__tmp;      \
206
0
  int __comp;             \
207
0
\
208
0
  SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = NULL;\
209
0
  __left = __right = &__node;         \
210
0
\
211
0
  while ((__comp = (cmp)(elm, (head)->sph_root))) {   \
212
0
    if (__comp < 0) {         \
213
0
      __tmp = SPLAY_LEFT((head)->sph_root, field);  \
214
0
      if (__tmp == NULL)       \
215
0
        break;         \
216
0
      if ((cmp)(elm, __tmp) < 0){     \
217
0
        SPLAY_ROTATE_RIGHT(head, __tmp, field); \
218
0
        if (SPLAY_LEFT((head)->sph_root, field) == NULL)\
219
0
          break;       \
220
0
      }           \
221
0
      SPLAY_LINKLEFT(head, __right, field);   \
222
0
    } else if (__comp > 0) {       \
223
0
      __tmp = SPLAY_RIGHT((head)->sph_root, field);  \
224
0
      if (__tmp == NULL)       \
225
0
        break;         \
226
0
      if ((cmp)(elm, __tmp) > 0){     \
227
0
        SPLAY_ROTATE_LEFT(head, __tmp, field); \
228
0
        if (SPLAY_RIGHT((head)->sph_root, field) == NULL)\
229
0
          break;       \
230
0
      }           \
231
0
      SPLAY_LINKRIGHT(head, __left, field);    \
232
0
    }              \
233
0
  }               \
234
0
  SPLAY_ASSEMBLE(head, &__node, __left, __right, field);    \
235
0
}                  \
236
                  \
237
/* Splay with either the minimum or the maximum element     \
238
 * Used to find minimum or maximum element in tree.     \
239
 */                 \
240
0
void name##_SPLAY_MINMAX(struct name *head, int __comp) \
241
0
{                 \
242
0
  struct type __node, *__left, *__right, *__tmp;      \
243
0
\
244
0
  SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = NULL;\
245
0
  __left = __right = &__node;         \
246
0
\
247
0
  while (1) {             \
248
0
    if (__comp < 0) {         \
249
0
      __tmp = SPLAY_LEFT((head)->sph_root, field);  \
250
0
      if (__tmp == NULL)       \
251
0
        break;         \
252
0
      if (__comp < 0){       \
253
0
        SPLAY_ROTATE_RIGHT(head, __tmp, field); \
254
0
        if (SPLAY_LEFT((head)->sph_root, field) == NULL)\
255
0
          break;       \
256
0
      }           \
257
0
      SPLAY_LINKLEFT(head, __right, field);   \
258
0
    } else if (__comp > 0) {       \
259
0
      __tmp = SPLAY_RIGHT((head)->sph_root, field);  \
260
0
      if (__tmp == NULL)       \
261
0
        break;         \
262
0
      if (__comp > 0) {       \
263
0
        SPLAY_ROTATE_LEFT(head, __tmp, field); \
264
0
        if (SPLAY_RIGHT((head)->sph_root, field) == NULL)\
265
0
          break;       \
266
0
      }           \
267
0
      SPLAY_LINKRIGHT(head, __left, field);    \
268
0
    }              \
269
0
  }               \
270
0
  SPLAY_ASSEMBLE(head, &__node, __left, __right, field);    \
271
0
}
272
273
#define SPLAY_NEGINF  -1
274
#define SPLAY_INF 1
275
276
0
#define SPLAY_INSERT(name, x, y)  name##_SPLAY_INSERT(x, y)
277
0
#define SPLAY_REMOVE(name, x, y)  name##_SPLAY_REMOVE(x, y)
278
0
#define SPLAY_FIND(name, x, y)    name##_SPLAY_FIND(x, y)
279
#define SPLAY_NEXT(name, x, y)    name##_SPLAY_NEXT(x, y)
280
#define SPLAY_MIN(name, x)    (SPLAY_EMPTY(x) ? NULL  \
281
          : name##_SPLAY_MIN_MAX(x, SPLAY_NEGINF))
282
#define SPLAY_MAX(name, x)    (SPLAY_EMPTY(x) ? NULL  \
283
          : name##_SPLAY_MIN_MAX(x, SPLAY_INF))
284
285
#define SPLAY_FOREACH(x, name, head)          \
286
  for ((x) = SPLAY_MIN(name, head);       \
287
       (x) != NULL;           \
288
       (x) = SPLAY_NEXT(name, head, x))
289
290
/* Macros that define a red-back tree */
291
#define RB_HEAD(name, type)           \
292
struct name {               \
293
  struct type *rbh_root; /* root of the tree */     \
294
}
295
296
#define RB_INITIALIZER(root)            \
297
  { NULL }
298
299
#define RB_INIT(root) do {            \
300
  (root)->rbh_root = NULL;          \
301
} while (0)
302
303
#define RB_BLACK  0
304
#define RB_RED    1
305
#define RB_ENTRY(type)              \
306
struct {                \
307
  struct type *rbe_left;    /* left element */    \
308
  struct type *rbe_right;   /* right element */   \
309
  struct type *rbe_parent;  /* parent element */    \
310
  int rbe_color;      /* node color */    \
311
}
312
313
#define RB_LEFT(elm, field)   (elm)->field.rbe_left
314
#define RB_RIGHT(elm, field)    (elm)->field.rbe_right
315
#define RB_PARENT(elm, field)   (elm)->field.rbe_parent
316
#define RB_COLOR(elm, field)    (elm)->field.rbe_color
317
#define RB_ROOT(head)     (head)->rbh_root
318
#define RB_EMPTY(head)      (RB_ROOT(head) == NULL)
319
320
#define RB_SET(elm, parent, field) do {         \
321
  RB_PARENT(elm, field) = parent;         \
322
  RB_LEFT(elm, field) = RB_RIGHT(elm, field) = NULL;    \
323
  RB_COLOR(elm, field) = RB_RED;          \
324
} while (0)
325
326
#define RB_SET_BLACKRED(black, red, field) do {       \
327
  RB_COLOR(black, field) = RB_BLACK;        \
328
  RB_COLOR(red, field) = RB_RED;          \
329
} while (0)
330
331
#ifndef RB_AUGMENT
332
#define RB_AUGMENT(x)
333
#endif
334
335
#define RB_ROTATE_LEFT(head, elm, tmp, field) do {      \
336
  (tmp) = RB_RIGHT(elm, field);         \
337
  if ((RB_RIGHT(elm, field) = RB_LEFT(tmp, field))) {   \
338
    RB_PARENT(RB_LEFT(tmp, field), field) = (elm);    \
339
  }               \
340
  RB_AUGMENT(elm);            \
341
  if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field))) {    \
342
    if ((elm) == RB_LEFT(RB_PARENT(elm, field), field)) \
343
      RB_LEFT(RB_PARENT(elm, field), field) = (tmp);  \
344
    else              \
345
      RB_RIGHT(RB_PARENT(elm, field), field) = (tmp); \
346
  } else                \
347
    (head)->rbh_root = (tmp);       \
348
  RB_LEFT(tmp, field) = (elm);          \
349
  RB_PARENT(elm, field) = (tmp);          \
350
  RB_AUGMENT(tmp);            \
351
  if ((RB_PARENT(tmp, field)))          \
352
    RB_AUGMENT(RB_PARENT(tmp, field));      \
353
} while (0)
354
355
#define RB_ROTATE_RIGHT(head, elm, tmp, field) do {     \
356
  (tmp) = RB_LEFT(elm, field);          \
357
  if ((RB_LEFT(elm, field) = RB_RIGHT(tmp, field))) {   \
358
    RB_PARENT(RB_RIGHT(tmp, field), field) = (elm);   \
359
  }               \
360
  RB_AUGMENT(elm);            \
361
  if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field))) {    \
362
    if ((elm) == RB_LEFT(RB_PARENT(elm, field), field)) \
363
      RB_LEFT(RB_PARENT(elm, field), field) = (tmp);  \
364
    else              \
365
      RB_RIGHT(RB_PARENT(elm, field), field) = (tmp); \
366
  } else                \
367
    (head)->rbh_root = (tmp);       \
368
  RB_RIGHT(tmp, field) = (elm);         \
369
  RB_PARENT(elm, field) = (tmp);          \
370
  RB_AUGMENT(tmp);            \
371
  if ((RB_PARENT(tmp, field)))          \
372
    RB_AUGMENT(RB_PARENT(tmp, field));      \
373
} while (0)
374
375
/* Generates prototypes and inline functions */
376
#define RB_PROTOTYPE(name, type, field, cmp)        \
377
void name##_RB_INSERT_COLOR(struct name *, struct type *);  \
378
void name##_RB_REMOVE_COLOR(struct name *, struct type *, struct type *);\
379
struct type *name##_RB_REMOVE(struct name *, struct type *);    \
380
struct type *name##_RB_INSERT(struct name *, struct type *);    \
381
struct type *name##_RB_FIND(struct name *, struct type *);    \
382
struct type *name##_RB_NEXT(struct type *);       \
383
struct type *name##_RB_MINMAX(struct name *, int);      \
384
                  \
385
386
/* Main rb operation.
387
 * Moves node close to the key of elm to top
388
 */
389
#define RB_GENERATE(name, type, field, cmp)       \
390
void                  \
391
name##_RB_INSERT_COLOR(struct name *head, struct type *elm)   \
392
{                 \
393
  struct type *parent, *gparent, *tmp;        \
394
  while ((parent = RB_PARENT(elm, field)) &&      \
395
      RB_COLOR(parent, field) == RB_RED) {      \
396
    gparent = RB_PARENT(parent, field);     \
397
    if (parent == RB_LEFT(gparent, field)) {    \
398
      tmp = RB_RIGHT(gparent, field);     \
399
      if (tmp && RB_COLOR(tmp, field) == RB_RED) {  \
400
        RB_COLOR(tmp, field) = RB_BLACK;  \
401
        RB_SET_BLACKRED(parent, gparent, field);\
402
        elm = gparent;        \
403
        continue;       \
404
      }           \
405
      if (RB_RIGHT(parent, field) == elm) {   \
406
        RB_ROTATE_LEFT(head, parent, tmp, field);\
407
        tmp = parent;       \
408
        parent = elm;       \
409
        elm = tmp;        \
410
      }           \
411
      RB_SET_BLACKRED(parent, gparent, field);  \
412
      RB_ROTATE_RIGHT(head, gparent, tmp, field); \
413
    } else {            \
414
      tmp = RB_LEFT(gparent, field);      \
415
      if (tmp && RB_COLOR(tmp, field) == RB_RED) {  \
416
        RB_COLOR(tmp, field) = RB_BLACK;  \
417
        RB_SET_BLACKRED(parent, gparent, field);\
418
        elm = gparent;        \
419
        continue;       \
420
      }           \
421
      if (RB_LEFT(parent, field) == elm) {    \
422
        RB_ROTATE_RIGHT(head, parent, tmp, field);\
423
        tmp = parent;       \
424
        parent = elm;       \
425
        elm = tmp;        \
426
      }           \
427
      RB_SET_BLACKRED(parent, gparent, field);  \
428
      RB_ROTATE_LEFT(head, gparent, tmp, field);  \
429
    }             \
430
  }               \
431
  RB_COLOR(head->rbh_root, field) = RB_BLACK;     \
432
}                 \
433
                  \
434
void                  \
435
name##_RB_REMOVE_COLOR(struct name *head, struct type *parent, struct type *elm) \
436
{                 \
437
  struct type *tmp;           \
438
  while ((elm == NULL || RB_COLOR(elm, field) == RB_BLACK) && \
439
      elm != RB_ROOT(head)) {         \
440
    if (RB_LEFT(parent, field) == elm) {      \
441
      tmp = RB_RIGHT(parent, field);      \
442
      if (RB_COLOR(tmp, field) == RB_RED) {   \
443
        RB_SET_BLACKRED(tmp, parent, field);  \
444
        RB_ROTATE_LEFT(head, parent, tmp, field);\
445
        tmp = RB_RIGHT(parent, field);    \
446
      }           \
447
      if ((RB_LEFT(tmp, field) == NULL ||   \
448
          RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
449
          (RB_RIGHT(tmp, field) == NULL ||    \
450
          RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
451
        RB_COLOR(tmp, field) = RB_RED;    \
452
        elm = parent;       \
453
        parent = RB_PARENT(elm, field);   \
454
      } else {          \
455
        if (RB_RIGHT(tmp, field) == NULL || \
456
            RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK) {\
457
          struct type *oleft;   \
458
          if ((oleft = RB_LEFT(tmp, field)))\
459
            RB_COLOR(oleft, field) = RB_BLACK;\
460
          RB_COLOR(tmp, field) = RB_RED;  \
461
          RB_ROTATE_RIGHT(head, tmp, oleft, field);\
462
          tmp = RB_RIGHT(parent, field);  \
463
        }         \
464
        RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
465
        RB_COLOR(parent, field) = RB_BLACK; \
466
        if (RB_RIGHT(tmp, field))   \
467
          RB_COLOR(RB_RIGHT(tmp, field), field) = RB_BLACK;\
468
        RB_ROTATE_LEFT(head, parent, tmp, field);\
469
        elm = RB_ROOT(head);      \
470
        break;          \
471
      }           \
472
    } else {            \
473
      tmp = RB_LEFT(parent, field);     \
474
      if (RB_COLOR(tmp, field) == RB_RED) {   \
475
        RB_SET_BLACKRED(tmp, parent, field);  \
476
        RB_ROTATE_RIGHT(head, parent, tmp, field);\
477
        tmp = RB_LEFT(parent, field);   \
478
      }           \
479
      if ((RB_LEFT(tmp, field) == NULL ||   \
480
          RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
481
          (RB_RIGHT(tmp, field) == NULL ||    \
482
          RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
483
        RB_COLOR(tmp, field) = RB_RED;    \
484
        elm = parent;       \
485
        parent = RB_PARENT(elm, field);   \
486
      } else {          \
487
        if (RB_LEFT(tmp, field) == NULL ||  \
488
            RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) {\
489
          struct type *oright;    \
490
          if ((oright = RB_RIGHT(tmp, field)))\
491
            RB_COLOR(oright, field) = RB_BLACK;\
492
          RB_COLOR(tmp, field) = RB_RED;  \
493
          RB_ROTATE_LEFT(head, tmp, oright, field);\
494
          tmp = RB_LEFT(parent, field); \
495
        }         \
496
        RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
497
        RB_COLOR(parent, field) = RB_BLACK; \
498
        if (RB_LEFT(tmp, field))    \
499
          RB_COLOR(RB_LEFT(tmp, field), field) = RB_BLACK;\
500
        RB_ROTATE_RIGHT(head, parent, tmp, field);\
501
        elm = RB_ROOT(head);      \
502
        break;          \
503
      }           \
504
    }             \
505
  }               \
506
  if (elm)              \
507
    RB_COLOR(elm, field) = RB_BLACK;      \
508
}                 \
509
                  \
510
struct type *               \
511
name##_RB_REMOVE(struct name *head, struct type *elm)     \
512
{                 \
513
  struct type *child, *parent, *old = elm;      \
514
  int color;              \
515
  if (RB_LEFT(elm, field) == NULL)        \
516
    child = RB_RIGHT(elm, field);       \
517
  else if (RB_RIGHT(elm, field) == NULL)        \
518
    child = RB_LEFT(elm, field);        \
519
  else {                \
520
    struct type *left;          \
521
    elm = RB_RIGHT(elm, field);       \
522
    while ((left = RB_LEFT(elm, field)))      \
523
      elm = left;         \
524
    child = RB_RIGHT(elm, field);       \
525
    parent = RB_PARENT(elm, field);       \
526
    color = RB_COLOR(elm, field);       \
527
    if (child)            \
528
      RB_PARENT(child, field) = parent;   \
529
    if (parent) {           \
530
      if (RB_LEFT(parent, field) == elm)    \
531
        RB_LEFT(parent, field) = child;   \
532
      else            \
533
        RB_RIGHT(parent, field) = child;  \
534
      RB_AUGMENT(parent);       \
535
    } else              \
536
      RB_ROOT(head) = child;        \
537
    if (RB_PARENT(elm, field) == old)     \
538
      parent = elm;         \
539
    (elm)->field = (old)->field;        \
540
    if (RB_PARENT(old, field)) {        \
541
      if (RB_LEFT(RB_PARENT(old, field), field) == old)\
542
        RB_LEFT(RB_PARENT(old, field), field) = elm;\
543
      else            \
544
        RB_RIGHT(RB_PARENT(old, field), field) = elm;\
545
      RB_AUGMENT(RB_PARENT(old, field));    \
546
    } else              \
547
      RB_ROOT(head) = elm;        \
548
    RB_PARENT(RB_LEFT(old, field), field) = elm;    \
549
    if (RB_RIGHT(old, field))       \
550
      RB_PARENT(RB_RIGHT(old, field), field) = elm; \
551
    if (parent) {           \
552
      left = parent;          \
553
      do {            \
554
        RB_AUGMENT(left);     \
555
      } while ((left = RB_PARENT(left, field)));  \
556
    }             \
557
    goto color;           \
558
  }               \
559
  parent = RB_PARENT(elm, field);         \
560
  color = RB_COLOR(elm, field);         \
561
  if (child)              \
562
    RB_PARENT(child, field) = parent;     \
563
  if (parent) {             \
564
    if (RB_LEFT(parent, field) == elm)      \
565
      RB_LEFT(parent, field) = child;     \
566
    else              \
567
      RB_RIGHT(parent, field) = child;    \
568
    RB_AUGMENT(parent);         \
569
  } else                \
570
    RB_ROOT(head) = child;          \
571
color:                  \
572
  if (color == RB_BLACK)            \
573
    name##_RB_REMOVE_COLOR(head, parent, child);    \
574
  return (old);             \
575
}                 \
576
                  \
577
/* Inserts a node into the RB tree */         \
578
struct type *               \
579
name##_RB_INSERT(struct name *head, struct type *elm)     \
580
{                 \
581
  struct type *tmp;           \
582
  struct type *parent = NULL;         \
583
  int comp = 0;             \
584
  tmp = RB_ROOT(head);            \
585
  while (tmp) {             \
586
    parent = tmp;           \
587
    comp = (cmp)(elm, parent);        \
588
    if (comp < 0)           \
589
      tmp = RB_LEFT(tmp, field);      \
590
    else if (comp > 0)          \
591
      tmp = RB_RIGHT(tmp, field);     \
592
    else              \
593
      return (tmp);         \
594
  }               \
595
  RB_SET(elm, parent, field);         \
596
  if (parent != NULL) {           \
597
    if (comp < 0)           \
598
      RB_LEFT(parent, field) = elm;     \
599
    else              \
600
      RB_RIGHT(parent, field) = elm;      \
601
    RB_AUGMENT(parent);         \
602
  } else                \
603
    RB_ROOT(head) = elm;          \
604
  name##_RB_INSERT_COLOR(head, elm);        \
605
  return (NULL);              \
606
}                 \
607
                  \
608
/* Finds the node with the same key as elm */       \
609
struct type *               \
610
name##_RB_FIND(struct name *head, struct type *elm)     \
611
{                 \
612
  struct type *tmp = RB_ROOT(head);       \
613
  int comp;             \
614
  while (tmp) {             \
615
    comp = cmp(elm, tmp);         \
616
    if (comp < 0)           \
617
      tmp = RB_LEFT(tmp, field);      \
618
    else if (comp > 0)          \
619
      tmp = RB_RIGHT(tmp, field);     \
620
    else              \
621
      return (tmp);         \
622
  }               \
623
  return (NULL);              \
624
}                 \
625
                  \
626
struct type *               \
627
name##_RB_NEXT(struct type *elm)          \
628
{                 \
629
  if (RB_RIGHT(elm, field)) {         \
630
    elm = RB_RIGHT(elm, field);       \
631
    while (RB_LEFT(elm, field))       \
632
      elm = RB_LEFT(elm, field);      \
633
  } else {              \
634
    if (RB_PARENT(elm, field) &&        \
635
        (elm == RB_LEFT(RB_PARENT(elm, field), field))) \
636
      elm = RB_PARENT(elm, field);      \
637
    else {              \
638
      while (RB_PARENT(elm, field) &&     \
639
          (elm == RB_RIGHT(RB_PARENT(elm, field), field)))\
640
        elm = RB_PARENT(elm, field);    \
641
      elm = RB_PARENT(elm, field);      \
642
    }             \
643
  }               \
644
  return (elm);             \
645
}                 \
646
                  \
647
struct type *               \
648
name##_RB_MINMAX(struct name *head, int val)        \
649
{                 \
650
  struct type *tmp = RB_ROOT(head);       \
651
  struct type *parent = NULL;         \
652
  while (tmp) {             \
653
    parent = tmp;           \
654
    if (val < 0)            \
655
      tmp = RB_LEFT(tmp, field);      \
656
    else              \
657
      tmp = RB_RIGHT(tmp, field);     \
658
  }               \
659
  return (parent);            \
660
}
661
662
#define RB_NEGINF -1
663
#define RB_INF  1
664
665
#define RB_INSERT(name, x, y) name##_RB_INSERT(x, y)
666
#define RB_REMOVE(name, x, y) name##_RB_REMOVE(x, y)
667
#define RB_FIND(name, x, y) name##_RB_FIND(x, y)
668
#define RB_NEXT(name, x, y) name##_RB_NEXT(y)
669
#define RB_MIN(name, x)   name##_RB_MINMAX(x, RB_NEGINF)
670
#define RB_MAX(name, x)   name##_RB_MINMAX(x, RB_INF)
671
672
#define RB_FOREACH(x, name, head)         \
673
  for ((x) = RB_MIN(name, head);          \
674
       (x) != NULL;           \
675
       (x) = name##_RB_NEXT(x))
676
677
#endif  /* _SYS_TREE_H_ */