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rbtree.c File Reference
#include "postgres.h"
#include "lib/rbtree.h"
Include dependency graph for rbtree.c:

Go to the source code of this file.

Data Structures

struct  RBTree
 

Macros

#define RBTBLACK   (0)
 
#define RBTRED   (1)
 
#define RBTNIL   (&sentinel)
 

Functions

RBTreerbt_create (Size node_size, rbt_comparator comparator, rbt_combiner combiner, rbt_allocfunc allocfunc, rbt_freefunc freefunc, void *arg)
 
static void rbt_copy_data (RBTree *rbt, RBTNode *dest, const RBTNode *src)
 
RBTNoderbt_find (RBTree *rbt, const RBTNode *data)
 
RBTNoderbt_find_great (RBTree *rbt, const RBTNode *data, bool equal_match)
 
RBTNoderbt_find_less (RBTree *rbt, const RBTNode *data, bool equal_match)
 
RBTNoderbt_leftmost (RBTree *rbt)
 
static void rbt_rotate_left (RBTree *rbt, RBTNode *x)
 
static void rbt_rotate_right (RBTree *rbt, RBTNode *x)
 
static void rbt_insert_fixup (RBTree *rbt, RBTNode *x)
 
RBTNoderbt_insert (RBTree *rbt, const RBTNode *data, bool *isNew)
 
static void rbt_delete_fixup (RBTree *rbt, RBTNode *x)
 
static void rbt_delete_node (RBTree *rbt, RBTNode *z)
 
void rbt_delete (RBTree *rbt, RBTNode *node)
 
static RBTNoderbt_left_right_iterator (RBTreeIterator *iter)
 
static RBTNoderbt_right_left_iterator (RBTreeIterator *iter)
 
void rbt_begin_iterate (RBTree *rbt, RBTOrderControl ctrl, RBTreeIterator *iter)
 
RBTNoderbt_iterate (RBTreeIterator *iter)
 

Variables

static RBTNode sentinel
 

Macro Definition Documentation

◆ RBTBLACK

#define RBTBLACK   (0)

Definition at line 35 of file rbtree.c.

◆ RBTNIL

#define RBTNIL   (&sentinel)

Definition at line 61 of file rbtree.c.

◆ RBTRED

#define RBTRED   (1)

Definition at line 36 of file rbtree.c.

Function Documentation

◆ rbt_begin_iterate()

void rbt_begin_iterate ( RBTree rbt,
RBTOrderControl  ctrl,
RBTreeIterator iter 
)

Definition at line 802 of file rbtree.c.

803 {
804  /* Common initialization for all traversal orders */
805  iter->rbt = rbt;
806  iter->last_visited = NULL;
807  iter->is_over = (rbt->root == RBTNIL);
808 
809  switch (ctrl)
810  {
811  case LeftRightWalk: /* visit left, then self, then right */
813  break;
814  case RightLeftWalk: /* visit right, then self, then left */
816  break;
817  default:
818  elog(ERROR, "unrecognized rbtree iteration order: %d", ctrl);
819  }
820 }
#define ERROR
Definition: elog.h:39
#define elog(elevel,...)
Definition: elog.h:225
static RBTNode * rbt_right_left_iterator(RBTreeIterator *iter)
Definition: rbtree.c:747
#define RBTNIL
Definition: rbtree.c:61
static RBTNode * rbt_left_right_iterator(RBTreeIterator *iter)
Definition: rbtree.c:705
@ RightLeftWalk
Definition: rbtree.h:38
@ LeftRightWalk
Definition: rbtree.h:37
bool is_over
Definition: rbtree.h:53
RBTree * rbt
Definition: rbtree.h:50
RBTNode *(* iterate)(RBTreeIterator *iter)
Definition: rbtree.h:51
RBTNode * last_visited
Definition: rbtree.h:52
RBTNode * root
Definition: rbtree.c:43

References elog, ERROR, RBTreeIterator::is_over, RBTreeIterator::iterate, RBTreeIterator::last_visited, LeftRightWalk, RBTreeIterator::rbt, rbt_left_right_iterator(), rbt_right_left_iterator(), RBTNIL, RightLeftWalk, and RBTree::root.

Referenced by ginBeginBAScan(), testleftright(), and testrightleft().

◆ rbt_copy_data()

static void rbt_copy_data ( RBTree rbt,
RBTNode dest,
const RBTNode src 
)
inlinestatic

Definition at line 127 of file rbtree.c.

128 {
129  memcpy(dest + 1, src + 1, rbt->node_size - sizeof(RBTNode));
130 }
Definition: rbtree.h:24
Size node_size
Definition: rbtree.c:47

References generate_unaccent_rules::dest, and RBTree::node_size.

Referenced by rbt_delete_node(), and rbt_insert().

◆ rbt_create()

RBTree* rbt_create ( Size  node_size,
rbt_comparator  comparator,
rbt_combiner  combiner,
rbt_allocfunc  allocfunc,
rbt_freefunc  freefunc,
void *  arg 
)

Definition at line 102 of file rbtree.c.

108 {
109  RBTree *tree = (RBTree *) palloc(sizeof(RBTree));
110 
111  Assert(node_size > sizeof(RBTNode));
112 
113  tree->root = RBTNIL;
114  tree->node_size = node_size;
115  tree->comparator = comparator;
116  tree->combiner = combiner;
117  tree->allocfunc = allocfunc;
118  tree->freefunc = freefunc;
119 
120  tree->arg = arg;
121 
122  return tree;
123 }
#define Assert(condition)
Definition: c.h:863
void * palloc(Size size)
Definition: mcxt.c:1317
void * arg
tree
Definition: radixtree.h:1834
Definition: rbtree.c:42

References arg, Assert, palloc(), RBTNIL, and tree.

Referenced by create_int_rbtree(), and ginInitBA().

◆ rbt_delete()

void rbt_delete ( RBTree rbt,
RBTNode node 
)

Definition at line 695 of file rbtree.c.

696 {
697  rbt_delete_node(rbt, node);
698 }
static void rbt_delete_node(RBTree *rbt, RBTNode *z)
Definition: rbtree.c:619

References rbt_delete_node().

Referenced by testdelete(), and testfindltgt().

◆ rbt_delete_fixup()

static void rbt_delete_fixup ( RBTree rbt,
RBTNode x 
)
static

Definition at line 521 of file rbtree.c.

522 {
523  /*
524  * x is always a black node. Initially, it is the former child of the
525  * deleted node. Each iteration of this loop moves it higher up in the
526  * tree.
527  */
528  while (x != rbt->root && x->color == RBTBLACK)
529  {
530  /*
531  * Left and right cases are symmetric. Any nodes that are children of
532  * x have a black-height one less than the remainder of the nodes in
533  * the tree. We rotate and recolor nodes to move the problem up the
534  * tree: at some stage we'll either fix the problem, or reach the root
535  * (where the black-height is allowed to decrease).
536  */
537  if (x == x->parent->left)
538  {
539  RBTNode *w = x->parent->right;
540 
541  if (w->color == RBTRED)
542  {
543  w->color = RBTBLACK;
544  x->parent->color = RBTRED;
545 
546  rbt_rotate_left(rbt, x->parent);
547  w = x->parent->right;
548  }
549 
550  if (w->left->color == RBTBLACK && w->right->color == RBTBLACK)
551  {
552  w->color = RBTRED;
553 
554  x = x->parent;
555  }
556  else
557  {
558  if (w->right->color == RBTBLACK)
559  {
560  w->left->color = RBTBLACK;
561  w->color = RBTRED;
562 
563  rbt_rotate_right(rbt, w);
564  w = x->parent->right;
565  }
566  w->color = x->parent->color;
567  x->parent->color = RBTBLACK;
568  w->right->color = RBTBLACK;
569 
570  rbt_rotate_left(rbt, x->parent);
571  x = rbt->root; /* Arrange for loop to terminate. */
572  }
573  }
574  else
575  {
576  RBTNode *w = x->parent->left;
577 
578  if (w->color == RBTRED)
579  {
580  w->color = RBTBLACK;
581  x->parent->color = RBTRED;
582 
583  rbt_rotate_right(rbt, x->parent);
584  w = x->parent->left;
585  }
586 
587  if (w->right->color == RBTBLACK && w->left->color == RBTBLACK)
588  {
589  w->color = RBTRED;
590 
591  x = x->parent;
592  }
593  else
594  {
595  if (w->left->color == RBTBLACK)
596  {
597  w->right->color = RBTBLACK;
598  w->color = RBTRED;
599 
600  rbt_rotate_left(rbt, w);
601  w = x->parent->left;
602  }
603  w->color = x->parent->color;
604  x->parent->color = RBTBLACK;
605  w->left->color = RBTBLACK;
606 
607  rbt_rotate_right(rbt, x->parent);
608  x = rbt->root; /* Arrange for loop to terminate. */
609  }
610  }
611  }
612  x->color = RBTBLACK;
613 }
int x
Definition: isn.c:70
static void rbt_rotate_right(RBTree *rbt, RBTNode *x)
Definition: rbtree.c:300
#define RBTBLACK
Definition: rbtree.c:35
static void rbt_rotate_left(RBTree *rbt, RBTNode *x)
Definition: rbtree.c:263
#define RBTRED
Definition: rbtree.c:36
char color
Definition: rbtree.h:25
struct RBTNode * left
Definition: rbtree.h:26
struct RBTNode * right
Definition: rbtree.h:27

References RBTNode::color, RBTNode::left, rbt_rotate_left(), rbt_rotate_right(), RBTBLACK, RBTRED, RBTNode::right, RBTree::root, and x.

Referenced by rbt_delete_node().

◆ rbt_delete_node()

static void rbt_delete_node ( RBTree rbt,
RBTNode z 
)
static

Definition at line 619 of file rbtree.c.

620 {
621  RBTNode *x,
622  *y;
623 
624  /* This is just paranoia: we should only get called on a valid node */
625  if (!z || z == RBTNIL)
626  return;
627 
628  /*
629  * y is the node that will actually be removed from the tree. This will
630  * be z if z has fewer than two children, or the tree successor of z
631  * otherwise.
632  */
633  if (z->left == RBTNIL || z->right == RBTNIL)
634  {
635  /* y has a RBTNIL node as a child */
636  y = z;
637  }
638  else
639  {
640  /* find tree successor */
641  y = z->right;
642  while (y->left != RBTNIL)
643  y = y->left;
644  }
645 
646  /* x is y's only child */
647  if (y->left != RBTNIL)
648  x = y->left;
649  else
650  x = y->right;
651 
652  /* Remove y from the tree. */
653  x->parent = y->parent;
654  if (y->parent)
655  {
656  if (y == y->parent->left)
657  y->parent->left = x;
658  else
659  y->parent->right = x;
660  }
661  else
662  {
663  rbt->root = x;
664  }
665 
666  /*
667  * If we removed the tree successor of z rather than z itself, then move
668  * the data for the removed node to the one we were supposed to remove.
669  */
670  if (y != z)
671  rbt_copy_data(rbt, z, y);
672 
673  /*
674  * Removing a black node might make some paths from root to leaf contain
675  * fewer black nodes than others, or it might make two red nodes adjacent.
676  */
677  if (y->color == RBTBLACK)
678  rbt_delete_fixup(rbt, x);
679 
680  /* Now we can recycle the y node */
681  if (rbt->freefunc)
682  rbt->freefunc(y, rbt->arg);
683 }
int y
Definition: isn.c:71
static void rbt_delete_fixup(RBTree *rbt, RBTNode *x)
Definition: rbtree.c:521
static void rbt_copy_data(RBTree *rbt, RBTNode *dest, const RBTNode *src)
Definition: rbtree.c:127
void * arg
Definition: rbtree.c:54
rbt_freefunc freefunc
Definition: rbtree.c:52

References RBTree::arg, RBTree::freefunc, RBTNode::left, rbt_copy_data(), rbt_delete_fixup(), RBTBLACK, RBTNIL, RBTNode::right, RBTree::root, x, and y.

Referenced by rbt_delete().

◆ rbt_find()

RBTNode* rbt_find ( RBTree rbt,
const RBTNode data 
)

Definition at line 145 of file rbtree.c.

146 {
147  RBTNode *node = rbt->root;
148 
149  while (node != RBTNIL)
150  {
151  int cmp = rbt->comparator(data, node, rbt->arg);
152 
153  if (cmp == 0)
154  return node;
155  else if (cmp < 0)
156  node = node->left;
157  else
158  node = node->right;
159  }
160 
161  return NULL;
162 }
const void * data
static int cmp(const chr *x, const chr *y, size_t len)
Definition: regc_locale.c:743
rbt_comparator comparator
Definition: rbtree.c:49

References RBTree::arg, cmp(), RBTree::comparator, data, RBTNode::left, RBTNIL, RBTNode::right, and RBTree::root.

Referenced by testdelete(), and testfind().

◆ rbt_find_great()

RBTNode* rbt_find_great ( RBTree rbt,
const RBTNode data,
bool  equal_match 
)

Definition at line 172 of file rbtree.c.

173 {
174  RBTNode *node = rbt->root;
175  RBTNode *greater = NULL;
176 
177  while (node != RBTNIL)
178  {
179  int cmp = rbt->comparator(data, node, rbt->arg);
180 
181  if (equal_match && cmp == 0)
182  return node;
183  else if (cmp < 0)
184  {
185  greater = node;
186  node = node->left;
187  }
188  else
189  node = node->right;
190  }
191 
192  return greater;
193 }

References RBTree::arg, cmp(), RBTree::comparator, data, RBTNode::left, RBTNIL, RBTNode::right, and RBTree::root.

Referenced by testfindltgt().

◆ rbt_find_less()

RBTNode* rbt_find_less ( RBTree rbt,
const RBTNode data,
bool  equal_match 
)

Definition at line 203 of file rbtree.c.

204 {
205  RBTNode *node = rbt->root;
206  RBTNode *lesser = NULL;
207 
208  while (node != RBTNIL)
209  {
210  int cmp = rbt->comparator(data, node, rbt->arg);
211 
212  if (equal_match && cmp == 0)
213  return node;
214  else if (cmp > 0)
215  {
216  lesser = node;
217  node = node->right;
218  }
219  else
220  node = node->left;
221  }
222 
223  return lesser;
224 }

References RBTree::arg, cmp(), RBTree::comparator, data, RBTNode::left, RBTNIL, RBTNode::right, and RBTree::root.

Referenced by testfindltgt().

◆ rbt_insert()

RBTNode* rbt_insert ( RBTree rbt,
const RBTNode data,
bool isNew 
)

Definition at line 453 of file rbtree.c.

454 {
455  RBTNode *current,
456  *parent,
457  *x;
458  int cmp;
459 
460  /* find where node belongs */
461  current = rbt->root;
462  parent = NULL;
463  cmp = 0; /* just to prevent compiler warning */
464 
465  while (current != RBTNIL)
466  {
467  cmp = rbt->comparator(data, current, rbt->arg);
468  if (cmp == 0)
469  {
470  /*
471  * Found node with given key. Apply combiner.
472  */
473  rbt->combiner(current, data, rbt->arg);
474  *isNew = false;
475  return current;
476  }
477  parent = current;
478  current = (cmp < 0) ? current->left : current->right;
479  }
480 
481  /*
482  * Value is not present, so create a new node containing data.
483  */
484  *isNew = true;
485 
486  x = rbt->allocfunc(rbt->arg);
487 
488  x->color = RBTRED;
489 
490  x->left = RBTNIL;
491  x->right = RBTNIL;
492  x->parent = parent;
493  rbt_copy_data(rbt, x, data);
494 
495  /* insert node in tree */
496  if (parent)
497  {
498  if (cmp < 0)
499  parent->left = x;
500  else
501  parent->right = x;
502  }
503  else
504  {
505  rbt->root = x;
506  }
507 
508  rbt_insert_fixup(rbt, x);
509 
510  return x;
511 }
static void rbt_insert_fixup(RBTree *rbt, RBTNode *x)
Definition: rbtree.c:344
rbt_allocfunc allocfunc
Definition: rbtree.c:51
rbt_combiner combiner
Definition: rbtree.c:50

References RBTree::allocfunc, RBTree::arg, cmp(), RBTree::combiner, RBTree::comparator, data, RBTNode::left, rbt_copy_data(), rbt_insert_fixup(), RBTNIL, RBTRED, RBTNode::right, RBTree::root, and x.

Referenced by ginInsertBAEntry(), and rbt_populate().

◆ rbt_insert_fixup()

static void rbt_insert_fixup ( RBTree rbt,
RBTNode x 
)
static

Definition at line 344 of file rbtree.c.

345 {
346  /*
347  * x is always a red node. Initially, it is the newly inserted node. Each
348  * iteration of this loop moves it higher up in the tree.
349  */
350  while (x != rbt->root && x->parent->color == RBTRED)
351  {
352  /*
353  * x and x->parent are both red. Fix depends on whether x->parent is
354  * a left or right child. In either case, we define y to be the
355  * "uncle" of x, that is, the other child of x's grandparent.
356  *
357  * If the uncle is red, we flip the grandparent to red and its two
358  * children to black. Then we loop around again to check whether the
359  * grandparent still has a problem.
360  *
361  * If the uncle is black, we will perform one or two "rotations" to
362  * balance the tree. Either x or x->parent will take the
363  * grandparent's position in the tree and recolored black, and the
364  * original grandparent will be recolored red and become a child of
365  * that node. This always leaves us with a valid red-black tree, so
366  * the loop will terminate.
367  */
368  if (x->parent == x->parent->parent->left)
369  {
370  RBTNode *y = x->parent->parent->right;
371 
372  if (y->color == RBTRED)
373  {
374  /* uncle is RBTRED */
375  x->parent->color = RBTBLACK;
376  y->color = RBTBLACK;
377  x->parent->parent->color = RBTRED;
378 
379  x = x->parent->parent;
380  }
381  else
382  {
383  /* uncle is RBTBLACK */
384  if (x == x->parent->right)
385  {
386  /* make x a left child */
387  x = x->parent;
388  rbt_rotate_left(rbt, x);
389  }
390 
391  /* recolor and rotate */
392  x->parent->color = RBTBLACK;
393  x->parent->parent->color = RBTRED;
394 
395  rbt_rotate_right(rbt, x->parent->parent);
396  }
397  }
398  else
399  {
400  /* mirror image of above code */
401  RBTNode *y = x->parent->parent->left;
402 
403  if (y->color == RBTRED)
404  {
405  /* uncle is RBTRED */
406  x->parent->color = RBTBLACK;
407  y->color = RBTBLACK;
408  x->parent->parent->color = RBTRED;
409 
410  x = x->parent->parent;
411  }
412  else
413  {
414  /* uncle is RBTBLACK */
415  if (x == x->parent->left)
416  {
417  x = x->parent;
418  rbt_rotate_right(rbt, x);
419  }
420  x->parent->color = RBTBLACK;
421  x->parent->parent->color = RBTRED;
422 
423  rbt_rotate_left(rbt, x->parent->parent);
424  }
425  }
426  }
427 
428  /*
429  * The root may already have been black; if not, the black-height of every
430  * node in the tree increases by one.
431  */
432  rbt->root->color = RBTBLACK;
433 }

References RBTNode::color, rbt_rotate_left(), rbt_rotate_right(), RBTBLACK, RBTRED, RBTree::root, x, and y.

Referenced by rbt_insert().

◆ rbt_iterate()

RBTNode* rbt_iterate ( RBTreeIterator iter)

Definition at line 826 of file rbtree.c.

827 {
828  if (iter->is_over)
829  return NULL;
830 
831  return iter->iterate(iter);
832 }

References RBTreeIterator::is_over, and RBTreeIterator::iterate.

Referenced by ginGetBAEntry(), testleftright(), and testrightleft().

◆ rbt_left_right_iterator()

static RBTNode* rbt_left_right_iterator ( RBTreeIterator iter)
static

Definition at line 705 of file rbtree.c.

706 {
707  if (iter->last_visited == NULL)
708  {
709  iter->last_visited = iter->rbt->root;
710  while (iter->last_visited->left != RBTNIL)
711  iter->last_visited = iter->last_visited->left;
712 
713  return iter->last_visited;
714  }
715 
716  if (iter->last_visited->right != RBTNIL)
717  {
718  iter->last_visited = iter->last_visited->right;
719  while (iter->last_visited->left != RBTNIL)
720  iter->last_visited = iter->last_visited->left;
721 
722  return iter->last_visited;
723  }
724 
725  for (;;)
726  {
727  RBTNode *came_from = iter->last_visited;
728 
729  iter->last_visited = iter->last_visited->parent;
730  if (iter->last_visited == NULL)
731  {
732  iter->is_over = true;
733  break;
734  }
735 
736  if (iter->last_visited->left == came_from)
737  break; /* came from left sub-tree, return current
738  * node */
739 
740  /* else - came from right sub-tree, continue to move up */
741  }
742 
743  return iter->last_visited;
744 }
struct RBTNode * parent
Definition: rbtree.h:28

References RBTreeIterator::is_over, RBTreeIterator::last_visited, RBTNode::left, RBTNode::parent, RBTreeIterator::rbt, RBTNIL, RBTNode::right, and RBTree::root.

Referenced by rbt_begin_iterate().

◆ rbt_leftmost()

RBTNode* rbt_leftmost ( RBTree rbt)

Definition at line 235 of file rbtree.c.

236 {
237  RBTNode *node = rbt->root;
238  RBTNode *leftmost = rbt->root;
239 
240  while (node != RBTNIL)
241  {
242  leftmost = node;
243  node = node->left;
244  }
245 
246  if (leftmost != RBTNIL)
247  return leftmost;
248 
249  return NULL;
250 }

References RBTNode::left, RBTNIL, and RBTree::root.

Referenced by testdelete(), and testleftmost().

◆ rbt_right_left_iterator()

static RBTNode* rbt_right_left_iterator ( RBTreeIterator iter)
static

Definition at line 747 of file rbtree.c.

748 {
749  if (iter->last_visited == NULL)
750  {
751  iter->last_visited = iter->rbt->root;
752  while (iter->last_visited->right != RBTNIL)
753  iter->last_visited = iter->last_visited->right;
754 
755  return iter->last_visited;
756  }
757 
758  if (iter->last_visited->left != RBTNIL)
759  {
760  iter->last_visited = iter->last_visited->left;
761  while (iter->last_visited->right != RBTNIL)
762  iter->last_visited = iter->last_visited->right;
763 
764  return iter->last_visited;
765  }
766 
767  for (;;)
768  {
769  RBTNode *came_from = iter->last_visited;
770 
771  iter->last_visited = iter->last_visited->parent;
772  if (iter->last_visited == NULL)
773  {
774  iter->is_over = true;
775  break;
776  }
777 
778  if (iter->last_visited->right == came_from)
779  break; /* came from right sub-tree, return current
780  * node */
781 
782  /* else - came from left sub-tree, continue to move up */
783  }
784 
785  return iter->last_visited;
786 }

References RBTreeIterator::is_over, RBTreeIterator::last_visited, RBTNode::left, RBTNode::parent, RBTreeIterator::rbt, RBTNIL, RBTNode::right, and RBTree::root.

Referenced by rbt_begin_iterate().

◆ rbt_rotate_left()

static void rbt_rotate_left ( RBTree rbt,
RBTNode x 
)
static

Definition at line 263 of file rbtree.c.

264 {
265  RBTNode *y = x->right;
266 
267  /* establish x->right link */
268  x->right = y->left;
269  if (y->left != RBTNIL)
270  y->left->parent = x;
271 
272  /* establish y->parent link */
273  if (y != RBTNIL)
274  y->parent = x->parent;
275  if (x->parent)
276  {
277  if (x == x->parent->left)
278  x->parent->left = y;
279  else
280  x->parent->right = y;
281  }
282  else
283  {
284  rbt->root = y;
285  }
286 
287  /* link x and y */
288  y->left = x;
289  if (x != RBTNIL)
290  x->parent = y;
291 }

References RBTNIL, RBTree::root, x, and y.

Referenced by rbt_delete_fixup(), and rbt_insert_fixup().

◆ rbt_rotate_right()

static void rbt_rotate_right ( RBTree rbt,
RBTNode x 
)
static

Definition at line 300 of file rbtree.c.

301 {
302  RBTNode *y = x->left;
303 
304  /* establish x->left link */
305  x->left = y->right;
306  if (y->right != RBTNIL)
307  y->right->parent = x;
308 
309  /* establish y->parent link */
310  if (y != RBTNIL)
311  y->parent = x->parent;
312  if (x->parent)
313  {
314  if (x == x->parent->right)
315  x->parent->right = y;
316  else
317  x->parent->left = y;
318  }
319  else
320  {
321  rbt->root = y;
322  }
323 
324  /* link x and y */
325  y->right = x;
326  if (x != RBTNIL)
327  x->parent = y;
328 }

References RBTNIL, RBTree::root, x, and y.

Referenced by rbt_delete_fixup(), and rbt_insert_fixup().

Variable Documentation

◆ sentinel

RBTNode sentinel
static
Initial value:
=
{
.color = RBTBLACK,.left = RBTNIL,.right = RBTNIL,.parent = NULL
}

Definition at line 63 of file rbtree.c.