1/*  $OpenBSD: tree.h,v 1.13 2011/07/09 00:19:45 pirofti 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)            \
58struct name {               \
59  struct type *sph_root; /* root of the tree */     \
60}
61
62#define SPLAY_INITIALIZER(root)           \
63  { NULL }
64
65#define SPLAY_INIT(root) do {           \
66  (root)->sph_root = NULL;          \
67} while (0)
68
69#define SPLAY_ENTRY(type)           \
70struct {                \
71  struct type *spe_left; /* left element */     \
72  struct type *spe_right; /* right element */     \
73}
74
75#define SPLAY_LEFT(elm, field)    (elm)->field.spe_left
76#define SPLAY_RIGHT(elm, field)   (elm)->field.spe_right
77#define SPLAY_ROOT(head)    (head)->sph_root
78#define SPLAY_EMPTY(head)   (SPLAY_ROOT(head) == NULL)
79
80/* SPLAY_ROTATE_{LEFT,RIGHT} expect that tmp hold SPLAY_{RIGHT,LEFT} */
81#define SPLAY_ROTATE_RIGHT(head, tmp, field) do {     \
82  SPLAY_LEFT((head)->sph_root, field) = SPLAY_RIGHT(tmp, field);  \
83  SPLAY_RIGHT(tmp, field) = (head)->sph_root;     \
84  (head)->sph_root = tmp;           \
85} while (0)
86
87#define SPLAY_ROTATE_LEFT(head, tmp, field) do {      \
88  SPLAY_RIGHT((head)->sph_root, field) = SPLAY_LEFT(tmp, field);  \
89  SPLAY_LEFT(tmp, field) = (head)->sph_root;      \
90  (head)->sph_root = tmp;           \
91} while (0)
92
93#define SPLAY_LINKLEFT(head, tmp, field) do {       \
94  SPLAY_LEFT(tmp, field) = (head)->sph_root;      \
95  tmp = (head)->sph_root;           \
96  (head)->sph_root = SPLAY_LEFT((head)->sph_root, field);   \
97} while (0)
98
99#define SPLAY_LINKRIGHT(head, tmp, field) do {        \
100  SPLAY_RIGHT(tmp, field) = (head)->sph_root;     \
101  tmp = (head)->sph_root;           \
102  (head)->sph_root = SPLAY_RIGHT((head)->sph_root, field);  \
103} while (0)
104
105#define SPLAY_ASSEMBLE(head, node, left, right, field) do {   \
106  SPLAY_RIGHT(left, field) = SPLAY_LEFT((head)->sph_root, field); \
107  SPLAY_LEFT(right, field) = SPLAY_RIGHT((head)->sph_root, field);\
108  SPLAY_LEFT((head)->sph_root, field) = SPLAY_RIGHT(node, field); \
109  SPLAY_RIGHT((head)->sph_root, field) = SPLAY_LEFT(node, field); \
110} while (0)
111
112/* Generates prototypes and inline functions */
113
114#define SPLAY_PROTOTYPE(name, type, field, cmp)       \
115void name##_SPLAY(struct name *, struct type *);      \
116void name##_SPLAY_MINMAX(struct name *, int);       \
117struct type *name##_SPLAY_INSERT(struct name *, struct type *);   \
118struct type *name##_SPLAY_REMOVE(struct name *, struct type *);   \
119                  \
120/* Finds the node with the same key as elm */       \
121static __inline struct type *           \
122name##_SPLAY_FIND(struct name *head, struct type *elm)      \
123{                 \
124  if (SPLAY_EMPTY(head))            \
125    return(NULL);           \
126  name##_SPLAY(head, elm);          \
127  if ((cmp)(elm, (head)->sph_root) == 0)        \
128    return (head->sph_root);        \
129  return (NULL);              \
130}                 \
131                  \
132static __inline struct type *           \
133name##_SPLAY_NEXT(struct name *head, struct type *elm)      \
134{                 \
135  name##_SPLAY(head, elm);          \
136  if (SPLAY_RIGHT(elm, field) != NULL) {        \
137    elm = SPLAY_RIGHT(elm, field);        \
138    while (SPLAY_LEFT(elm, field) != NULL) {    \
139      elm = SPLAY_LEFT(elm, field);     \
140    }             \
141  } else                \
142    elm = NULL;           \
143  return (elm);             \
144}                 \
145                  \
146static __inline struct type *           \
147name##_SPLAY_MIN_MAX(struct name *head, int val)      \
148{                 \
149  name##_SPLAY_MINMAX(head, val);         \
150        return (SPLAY_ROOT(head));          \
151}
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)        \
157struct type *               \
158name##_SPLAY_INSERT(struct name *head, struct type *elm)    \
159{                 \
160    if (SPLAY_EMPTY(head)) {            \
161      SPLAY_LEFT(elm, field) = SPLAY_RIGHT(elm, field) = NULL;  \
162    } else {                \
163      int __comp;             \
164      name##_SPLAY(head, elm);          \
165      __comp = (cmp)(elm, (head)->sph_root);      \
166      if(__comp < 0) {            \
167        SPLAY_LEFT(elm, field) = SPLAY_LEFT((head)->sph_root, field);\
168        SPLAY_RIGHT(elm, field) = (head)->sph_root;   \
169        SPLAY_LEFT((head)->sph_root, field) = NULL;   \
170      } else if (__comp > 0) {          \
171        SPLAY_RIGHT(elm, field) = SPLAY_RIGHT((head)->sph_root, field);\
172        SPLAY_LEFT(elm, field) = (head)->sph_root;    \
173        SPLAY_RIGHT((head)->sph_root, field) = NULL;  \
174      } else              \
175        return ((head)->sph_root);        \
176    }                 \
177    (head)->sph_root = (elm);           \
178    return (NULL);              \
179}                 \
180                  \
181struct type *               \
182name##_SPLAY_REMOVE(struct name *head, struct type *elm)    \
183{                 \
184  struct type *__tmp;           \
185  if (SPLAY_EMPTY(head))            \
186    return (NULL);            \
187  name##_SPLAY(head, elm);          \
188  if ((cmp)(elm, (head)->sph_root) == 0) {      \
189    if (SPLAY_LEFT((head)->sph_root, field) == NULL) {  \
190      (head)->sph_root = SPLAY_RIGHT((head)->sph_root, field);\
191    } else {            \
192      __tmp = SPLAY_RIGHT((head)->sph_root, field); \
193      (head)->sph_root = SPLAY_LEFT((head)->sph_root, field);\
194      name##_SPLAY(head, elm);      \
195      SPLAY_RIGHT((head)->sph_root, field) = __tmp; \
196    }             \
197    return (elm);           \
198  }               \
199  return (NULL);              \
200}                 \
201                  \
202void                  \
203name##_SPLAY(struct name *head, struct type *elm)     \
204{                 \
205  struct type __node, *__left, *__right, *__tmp;      \
206  int __comp;             \
207\
208  SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = NULL;\
209  __left = __right = &__node;         \
210\
211  while ((__comp = (cmp)(elm, (head)->sph_root))) {   \
212    if (__comp < 0) {         \
213      __tmp = SPLAY_LEFT((head)->sph_root, field);  \
214      if (__tmp == NULL)        \
215        break;          \
216      if ((cmp)(elm, __tmp) < 0){     \
217        SPLAY_ROTATE_RIGHT(head, __tmp, field); \
218        if (SPLAY_LEFT((head)->sph_root, field) == NULL)\
219          break;        \
220      }           \
221      SPLAY_LINKLEFT(head, __right, field);   \
222    } else if (__comp > 0) {        \
223      __tmp = SPLAY_RIGHT((head)->sph_root, field); \
224      if (__tmp == NULL)        \
225        break;          \
226      if ((cmp)(elm, __tmp) > 0){     \
227        SPLAY_ROTATE_LEFT(head, __tmp, field);  \
228        if (SPLAY_RIGHT((head)->sph_root, field) == NULL)\
229          break;        \
230      }           \
231      SPLAY_LINKRIGHT(head, __left, field);   \
232    }             \
233  }               \
234  SPLAY_ASSEMBLE(head, &__node, __left, __right, field);    \
235}                 \
236                  \
237/* Splay with either the minimum or the maximum element     \
238 * Used to find minimum or maximum element in tree.     \
239 */                 \
240void name##_SPLAY_MINMAX(struct name *head, int __comp) \
241{                 \
242  struct type __node, *__left, *__right, *__tmp;      \
243\
244  SPLAY_LEFT(&__node, field) = SPLAY_RIGHT(&__node, field) = NULL;\
245  __left = __right = &__node;         \
246\
247  while (1) {             \
248    if (__comp < 0) {         \
249      __tmp = SPLAY_LEFT((head)->sph_root, field);  \
250      if (__tmp == NULL)        \
251        break;          \
252      if (__comp < 0){        \
253        SPLAY_ROTATE_RIGHT(head, __tmp, field); \
254        if (SPLAY_LEFT((head)->sph_root, field) == NULL)\
255          break;        \
256      }           \
257      SPLAY_LINKLEFT(head, __right, field);   \
258    } else if (__comp > 0) {        \
259      __tmp = SPLAY_RIGHT((head)->sph_root, field); \
260      if (__tmp == NULL)        \
261        break;          \
262      if (__comp > 0) {       \
263        SPLAY_ROTATE_LEFT(head, __tmp, field);  \
264        if (SPLAY_RIGHT((head)->sph_root, field) == NULL)\
265          break;        \
266      }           \
267      SPLAY_LINKRIGHT(head, __left, field);   \
268    }             \
269  }               \
270  SPLAY_ASSEMBLE(head, &__node, __left, __right, field);    \
271}
272
273#define SPLAY_NEGINF  -1
274#define SPLAY_INF 1
275
276#define SPLAY_INSERT(name, x, y)  name##_SPLAY_INSERT(x, y)
277#define SPLAY_REMOVE(name, x, y)  name##_SPLAY_REMOVE(x, y)
278#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-black tree */
291#define RB_HEAD(name, type)           \
292struct 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)              \
306struct {                \
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) do {} while (0)
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  RB_PROTOTYPE_INTERNAL(name, type, field, cmp,)
378#define RB_PROTOTYPE_STATIC(name, type, field, cmp)     \
379  RB_PROTOTYPE_INTERNAL(name, type, field, cmp, __attribute__((__unused__)) static)
380#define RB_PROTOTYPE_INTERNAL(name, type, field, cmp, attr)   \
381attr void name##_RB_INSERT_COLOR(struct name *, struct type *);   \
382attr void name##_RB_REMOVE_COLOR(struct name *, struct type *, struct type *);\
383attr struct type *name##_RB_REMOVE(struct name *, struct type *); \
384attr struct type *name##_RB_INSERT(struct name *, struct type *); \
385attr struct type *name##_RB_FIND(struct name *, struct type *);   \
386attr struct type *name##_RB_NFIND(struct name *, struct type *);  \
387attr struct type *name##_RB_NEXT(struct type *);      \
388attr struct type *name##_RB_PREV(struct type *);      \
389attr struct type *name##_RB_MINMAX(struct name *, int);     \
390                  \
391
392/* Main rb operation.
393 * Moves node close to the key of elm to top
394 */
395#define RB_GENERATE(name, type, field, cmp)       \
396  RB_GENERATE_INTERNAL(name, type, field, cmp,)
397#define RB_GENERATE_STATIC(name, type, field, cmp)      \
398  RB_GENERATE_INTERNAL(name, type, field, cmp, __attribute__((__unused__)) static)
399#define RB_GENERATE_INTERNAL(name, type, field, cmp, attr)    \
400attr void               \
401name##_RB_INSERT_COLOR(struct name *head, struct type *elm)   \
402{                 \
403  struct type *parent, *gparent, *tmp;        \
404  while ((parent = RB_PARENT(elm, field)) &&      \
405      RB_COLOR(parent, field) == RB_RED) {      \
406    gparent = RB_PARENT(parent, field);     \
407    if (parent == RB_LEFT(gparent, field)) {    \
408      tmp = RB_RIGHT(gparent, field);     \
409      if (tmp && RB_COLOR(tmp, field) == RB_RED) {  \
410        RB_COLOR(tmp, field) = RB_BLACK;  \
411        RB_SET_BLACKRED(parent, gparent, field);\
412        elm = gparent;        \
413        continue;       \
414      }           \
415      if (RB_RIGHT(parent, field) == elm) {   \
416        RB_ROTATE_LEFT(head, parent, tmp, field);\
417        tmp = parent;       \
418        parent = elm;       \
419        elm = tmp;        \
420      }           \
421      RB_SET_BLACKRED(parent, gparent, field);  \
422      RB_ROTATE_RIGHT(head, gparent, tmp, field); \
423    } else {            \
424      tmp = RB_LEFT(gparent, field);      \
425      if (tmp && RB_COLOR(tmp, field) == RB_RED) {  \
426        RB_COLOR(tmp, field) = RB_BLACK;  \
427        RB_SET_BLACKRED(parent, gparent, field);\
428        elm = gparent;        \
429        continue;       \
430      }           \
431      if (RB_LEFT(parent, field) == elm) {    \
432        RB_ROTATE_RIGHT(head, parent, tmp, field);\
433        tmp = parent;       \
434        parent = elm;       \
435        elm = tmp;        \
436      }           \
437      RB_SET_BLACKRED(parent, gparent, field);  \
438      RB_ROTATE_LEFT(head, gparent, tmp, field);  \
439    }             \
440  }               \
441  RB_COLOR(head->rbh_root, field) = RB_BLACK;     \
442}                 \
443                  \
444attr void               \
445name##_RB_REMOVE_COLOR(struct name *head, struct type *parent, struct type *elm) \
446{                 \
447  struct type *tmp;           \
448  while ((elm == NULL || RB_COLOR(elm, field) == RB_BLACK) && \
449      elm != RB_ROOT(head)) {         \
450    if (RB_LEFT(parent, field) == elm) {      \
451      tmp = RB_RIGHT(parent, field);      \
452      if (RB_COLOR(tmp, field) == RB_RED) {   \
453        RB_SET_BLACKRED(tmp, parent, field);  \
454        RB_ROTATE_LEFT(head, parent, tmp, field);\
455        tmp = RB_RIGHT(parent, field);    \
456      }           \
457      if ((RB_LEFT(tmp, field) == NULL ||   \
458          RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
459          (RB_RIGHT(tmp, field) == NULL ||    \
460          RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
461        RB_COLOR(tmp, field) = RB_RED;    \
462        elm = parent;       \
463        parent = RB_PARENT(elm, field);   \
464      } else {          \
465        if (RB_RIGHT(tmp, field) == NULL || \
466            RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK) {\
467          struct type *oleft;   \
468          if ((oleft = RB_LEFT(tmp, field)))\
469            RB_COLOR(oleft, field) = RB_BLACK;\
470          RB_COLOR(tmp, field) = RB_RED;  \
471          RB_ROTATE_RIGHT(head, tmp, oleft, field);\
472          tmp = RB_RIGHT(parent, field);  \
473        }         \
474        RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
475        RB_COLOR(parent, field) = RB_BLACK; \
476        if (RB_RIGHT(tmp, field))   \
477          RB_COLOR(RB_RIGHT(tmp, field), field) = RB_BLACK;\
478        RB_ROTATE_LEFT(head, parent, tmp, field);\
479        elm = RB_ROOT(head);      \
480        break;          \
481      }           \
482    } else {            \
483      tmp = RB_LEFT(parent, field);     \
484      if (RB_COLOR(tmp, field) == RB_RED) {   \
485        RB_SET_BLACKRED(tmp, parent, field);  \
486        RB_ROTATE_RIGHT(head, parent, tmp, field);\
487        tmp = RB_LEFT(parent, field);   \
488      }           \
489      if ((RB_LEFT(tmp, field) == NULL ||   \
490          RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
491          (RB_RIGHT(tmp, field) == NULL ||    \
492          RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
493        RB_COLOR(tmp, field) = RB_RED;    \
494        elm = parent;       \
495        parent = RB_PARENT(elm, field);   \
496      } else {          \
497        if (RB_LEFT(tmp, field) == NULL ||  \
498            RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) {\
499          struct type *oright;    \
500          if ((oright = RB_RIGHT(tmp, field)))\
501            RB_COLOR(oright, field) = RB_BLACK;\
502          RB_COLOR(tmp, field) = RB_RED;  \
503          RB_ROTATE_LEFT(head, tmp, oright, field);\
504          tmp = RB_LEFT(parent, field); \
505        }         \
506        RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
507        RB_COLOR(parent, field) = RB_BLACK; \
508        if (RB_LEFT(tmp, field))    \
509          RB_COLOR(RB_LEFT(tmp, field), field) = RB_BLACK;\
510        RB_ROTATE_RIGHT(head, parent, tmp, field);\
511        elm = RB_ROOT(head);      \
512        break;          \
513      }           \
514    }             \
515  }               \
516  if (elm)              \
517    RB_COLOR(elm, field) = RB_BLACK;      \
518}                 \
519                  \
520attr struct type *              \
521name##_RB_REMOVE(struct name *head, struct type *elm)     \
522{                 \
523  struct type *child, *parent, *old = elm;      \
524  int color;              \
525  if (RB_LEFT(elm, field) == NULL)        \
526    child = RB_RIGHT(elm, field);       \
527  else if (RB_RIGHT(elm, field) == NULL)        \
528    child = RB_LEFT(elm, field);        \
529  else {                \
530    struct type *left;          \
531    elm = RB_RIGHT(elm, field);       \
532    while ((left = RB_LEFT(elm, field)))      \
533      elm = left;         \
534    child = RB_RIGHT(elm, field);       \
535    parent = RB_PARENT(elm, field);       \
536    color = RB_COLOR(elm, field);       \
537    if (child)            \
538      RB_PARENT(child, field) = parent;   \
539    if (parent) {           \
540      if (RB_LEFT(parent, field) == elm)    \
541        RB_LEFT(parent, field) = child;   \
542      else            \
543        RB_RIGHT(parent, field) = child;  \
544      RB_AUGMENT(parent);       \
545    } else              \
546      RB_ROOT(head) = child;        \
547    if (RB_PARENT(elm, field) == old)     \
548      parent = elm;         \
549    (elm)->field = (old)->field;        \
550    if (RB_PARENT(old, field)) {        \
551      if (RB_LEFT(RB_PARENT(old, field), field) == old)\
552        RB_LEFT(RB_PARENT(old, field), field) = elm;\
553      else            \
554        RB_RIGHT(RB_PARENT(old, field), field) = elm;\
555      RB_AUGMENT(RB_PARENT(old, field));    \
556    } else              \
557      RB_ROOT(head) = elm;        \
558    RB_PARENT(RB_LEFT(old, field), field) = elm;    \
559    if (RB_RIGHT(old, field))       \
560      RB_PARENT(RB_RIGHT(old, field), field) = elm; \
561    if (parent) {           \
562      left = parent;          \
563      do {            \
564        RB_AUGMENT(left);     \
565      } while ((left = RB_PARENT(left, field)));  \
566    }             \
567    goto color;           \
568  }               \
569  parent = RB_PARENT(elm, field);         \
570  color = RB_COLOR(elm, field);         \
571  if (child)              \
572    RB_PARENT(child, field) = parent;     \
573  if (parent) {             \
574    if (RB_LEFT(parent, field) == elm)      \
575      RB_LEFT(parent, field) = child;     \
576    else              \
577      RB_RIGHT(parent, field) = child;    \
578    RB_AUGMENT(parent);         \
579  } else                \
580    RB_ROOT(head) = child;          \
581color:                  \
582  if (color == RB_BLACK)            \
583    name##_RB_REMOVE_COLOR(head, parent, child);    \
584  return (old);             \
585}                 \
586                  \
587/* Inserts a node into the RB tree */         \
588attr struct type *              \
589name##_RB_INSERT(struct name *head, struct type *elm)     \
590{                 \
591  struct type *tmp;           \
592  struct type *parent = NULL;         \
593  int comp = 0;             \
594  tmp = RB_ROOT(head);            \
595  while (tmp) {             \
596    parent = tmp;           \
597    comp = (cmp)(elm, parent);        \
598    if (comp < 0)           \
599      tmp = RB_LEFT(tmp, field);      \
600    else if (comp > 0)          \
601      tmp = RB_RIGHT(tmp, field);     \
602    else              \
603      return (tmp);         \
604  }               \
605  RB_SET(elm, parent, field);         \
606  if (parent != NULL) {           \
607    if (comp < 0)           \
608      RB_LEFT(parent, field) = elm;     \
609    else              \
610      RB_RIGHT(parent, field) = elm;      \
611    RB_AUGMENT(parent);         \
612  } else                \
613    RB_ROOT(head) = elm;          \
614  name##_RB_INSERT_COLOR(head, elm);        \
615  return (NULL);              \
616}                 \
617                  \
618/* Finds the node with the same key as elm */       \
619attr struct type *              \
620name##_RB_FIND(struct name *head, struct type *elm)     \
621{                 \
622  struct type *tmp = RB_ROOT(head);       \
623  int comp;             \
624  while (tmp) {             \
625    comp = cmp(elm, tmp);         \
626    if (comp < 0)           \
627      tmp = RB_LEFT(tmp, field);      \
628    else if (comp > 0)          \
629      tmp = RB_RIGHT(tmp, field);     \
630    else              \
631      return (tmp);         \
632  }               \
633  return (NULL);              \
634}                 \
635                  \
636/* Finds the first node greater than or equal to the search key */  \
637attr struct type *              \
638name##_RB_NFIND(struct name *head, struct type *elm)      \
639{                 \
640  struct type *tmp = RB_ROOT(head);       \
641  struct type *res = NULL;          \
642  int comp;             \
643  while (tmp) {             \
644    comp = cmp(elm, tmp);         \
645    if (comp < 0) {           \
646      res = tmp;          \
647      tmp = RB_LEFT(tmp, field);      \
648    }             \
649    else if (comp > 0)          \
650      tmp = RB_RIGHT(tmp, field);     \
651    else              \
652      return (tmp);         \
653  }               \
654  return (res);             \
655}                 \
656                  \
657/* ARGSUSED */                \
658attr struct type *              \
659name##_RB_NEXT(struct type *elm)          \
660{                 \
661  if (RB_RIGHT(elm, field)) {         \
662    elm = RB_RIGHT(elm, field);       \
663    while (RB_LEFT(elm, field))       \
664      elm = RB_LEFT(elm, field);      \
665  } else {              \
666    if (RB_PARENT(elm, field) &&        \
667        (elm == RB_LEFT(RB_PARENT(elm, field), field))) \
668      elm = RB_PARENT(elm, field);      \
669    else {              \
670      while (RB_PARENT(elm, field) &&     \
671          (elm == RB_RIGHT(RB_PARENT(elm, field), field)))\
672        elm = RB_PARENT(elm, field);    \
673      elm = RB_PARENT(elm, field);      \
674    }             \
675  }               \
676  return (elm);             \
677}                 \
678                  \
679/* ARGSUSED */                \
680attr struct type *              \
681name##_RB_PREV(struct type *elm)          \
682{                 \
683  if (RB_LEFT(elm, field)) {          \
684    elm = RB_LEFT(elm, field);        \
685    while (RB_RIGHT(elm, field))        \
686      elm = RB_RIGHT(elm, field);     \
687  } else {              \
688    if (RB_PARENT(elm, field) &&        \
689        (elm == RB_RIGHT(RB_PARENT(elm, field), field)))  \
690      elm = RB_PARENT(elm, field);      \
691    else {              \
692      while (RB_PARENT(elm, field) &&     \
693          (elm == RB_LEFT(RB_PARENT(elm, field), field)))\
694        elm = RB_PARENT(elm, field);    \
695      elm = RB_PARENT(elm, field);      \
696    }             \
697  }               \
698  return (elm);             \
699}                 \
700                  \
701attr struct type *              \
702name##_RB_MINMAX(struct name *head, int val)        \
703{                 \
704  struct type *tmp = RB_ROOT(head);       \
705  struct type *parent = NULL;         \
706  while (tmp) {             \
707    parent = tmp;           \
708    if (val < 0)            \
709      tmp = RB_LEFT(tmp, field);      \
710    else              \
711      tmp = RB_RIGHT(tmp, field);     \
712  }               \
713  return (parent);            \
714}
715
716#define RB_NEGINF -1
717#define RB_INF  1
718
719#define RB_INSERT(name, x, y) name##_RB_INSERT(x, y)
720#define RB_REMOVE(name, x, y) name##_RB_REMOVE(x, y)
721#define RB_FIND(name, x, y) name##_RB_FIND(x, y)
722#define RB_NFIND(name, x, y)  name##_RB_NFIND(x, y)
723#define RB_NEXT(name, x, y) name##_RB_NEXT(y)
724#define RB_PREV(name, x, y) name##_RB_PREV(y)
725#define RB_MIN(name, x)   name##_RB_MINMAX(x, RB_NEGINF)
726#define RB_MAX(name, x)   name##_RB_MINMAX(x, RB_INF)
727
728#define RB_FOREACH(x, name, head)         \
729  for ((x) = RB_MIN(name, head);          \
730       (x) != NULL;           \
731       (x) = name##_RB_NEXT(x))
732
733#define RB_FOREACH_SAFE(x, name, head, y)       \
734  for ((x) = RB_MIN(name, head);          \
735      ((x) != NULL) && ((y) = name##_RB_NEXT(x), 1);    \
736       (x) = (y))
737
738#define RB_FOREACH_REVERSE(x, name, head)       \
739  for ((x) = RB_MAX(name, head);          \
740       (x) != NULL;           \
741       (x) = name##_RB_PREV(x))
742
743#define RB_FOREACH_REVERSE_SAFE(x, name, head, y)     \
744  for ((x) = RB_MAX(name, head);          \
745      ((x) != NULL) && ((y) = name##_RB_PREV(x), 1);    \
746       (x) = (y))
747
748#endif  /* _SYS_TREE_H_ */
749