2 * PacketBB handler library (see RFC 5444)
3 * Copyright (c) 2010 Henning Rogge <hrogge@googlemail.com>
4 * Original OLSRd implementation by Hannes Gredler <hannes@gredler.at>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
11 * * Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * * Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
17 * * Neither the name of olsr.org, olsrd nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific prior written permission.
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22 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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34 * Visit http://www.olsr.org/git for more information.
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37 * to the project. For more information see the website or contact
38 * the copyright holders.
52 * internal type save inline function to calculate the maximum of
53 * to integers without macro implementation.
55 * @param x first parameter of maximum function
56 * @param y second parameter of maximum function
57 * @return largest integer of both parameters
59 static inline int avl_max(int x
, int y
) {
64 * internal type save inline function to calculate the minimum of
65 * to integers without macro implementation.
67 * @param x first parameter of minimum function
68 * @param y second parameter of minimum function
69 * @return smallest integer of both parameters
71 static inline int avl_min(int x
, int y
) {
75 static struct avl_node
*
76 avl_find_rec(struct avl_node
*node
, const void *key
, avl_tree_comp comp
, void *ptr
, int *cmp_result
);
77 static void avl_insert_before(struct avl_tree
*tree
, struct avl_node
*pos_node
, struct avl_node
*node
);
78 static void avl_insert_after(struct avl_tree
*tree
, struct avl_node
*pos_node
, struct avl_node
*node
);
79 static void post_insert(struct avl_tree
*tree
, struct avl_node
*node
);
80 static void avl_delete_worker(struct avl_tree
*tree
, struct avl_node
*node
);
81 static void avl_remove(struct avl_tree
*tree
, struct avl_node
*node
);
84 * Initialize a new avl_tree struct
85 * @param tree pointer to avl-tree
86 * @param comp pointer to comparator for the tree
87 * @param allow_dups true if the tree allows multiple
88 * elements with the same
89 * @param ptr custom parameter for comparator
92 avl_init(struct avl_tree
*tree
, avl_tree_comp comp
, bool allow_dups
, void *ptr
)
94 INIT_LIST_HEAD(&tree
->list_head
);
98 tree
->allow_dups
= allow_dups
;
102 static inline struct avl_node
*avl_next(struct avl_node
*node
)
104 return list_entry(node
->list
.next
, struct avl_node
, list
);
108 * Finds a node in an avl-tree with a certain key
109 * @param tree pointer to avl-tree
110 * @param key pointer to key
111 * @return pointer to avl-node with key, NULL if no node with
115 avl_find(const struct avl_tree
*tree
, const void *key
)
117 struct avl_node
*node
;
120 if (tree
->root
== NULL
)
123 node
= avl_find_rec(tree
->root
, key
, tree
->comp
, tree
->cmp_ptr
, &diff
);
125 return diff
== 0 ? node
: NULL
;
129 * Finds the last node in an avl-tree with a key less or equal
130 * than the specified key
131 * @param tree pointer to avl-tree
132 * @param key pointer to specified key
133 * @return pointer to avl-node, NULL if no node with
134 * key less or equal specified key exists.
137 avl_find_lessequal(const struct avl_tree
*tree
, const void *key
) {
138 struct avl_node
*node
, *next
;
141 if (tree
->root
== NULL
)
144 node
= avl_find_rec(tree
->root
, key
, tree
->comp
, tree
->cmp_ptr
, &diff
);
146 /* go left as long as key<node.key */
148 if (list_is_first(&node
->list
, &tree
->list_head
)) {
152 node
= (struct avl_node
*)node
->list
.prev
;
153 diff
= (*tree
->comp
) (key
, node
->key
, tree
->cmp_ptr
);
156 /* go right as long as key>=next_node.key */
160 if (list_is_last(&node
->list
, &tree
->list_head
)) {
164 next
= (struct avl_node
*)node
->list
.next
;
165 diff
= (*tree
->comp
) (key
, next
->key
, tree
->cmp_ptr
);
171 * Finds the first node in an avl-tree with a key greater or equal
172 * than the specified key
173 * @param tree pointer to avl-tree
174 * @param key pointer to specified key
175 * @return pointer to avl-node, NULL if no node with
176 * key greater or equal specified key exists.
179 avl_find_greaterequal(const struct avl_tree
*tree
, const void *key
) {
180 struct avl_node
*node
, *next
;
183 if (tree
->root
== NULL
)
186 node
= avl_find_rec(tree
->root
, key
, tree
->comp
, tree
->cmp_ptr
, &diff
);
188 /* go right as long as key>node.key */
190 if (list_is_last(&node
->list
, &tree
->list_head
)) {
194 node
= (struct avl_node
*)node
->list
.next
;
195 diff
= (*tree
->comp
) (key
, node
->key
, tree
->cmp_ptr
);
198 /* go left as long as key<=next_node.key */
202 if (list_is_first(&node
->list
, &tree
->list_head
)) {
206 next
= (struct avl_node
*)node
->list
.prev
;
207 diff
= (*tree
->comp
) (key
, next
->key
, tree
->cmp_ptr
);
213 * Inserts an avl_node into a tree
214 * @param tree pointer to tree
215 * @param new pointer to node
216 * @return 0 if node was inserted successfully, -1 if it was not inserted
217 * because of a key collision
220 avl_insert(struct avl_tree
*tree
, struct avl_node
*new)
222 struct avl_node
*node
, *next
, *last
;
233 if (tree
->root
== NULL
) {
234 list_add(&new->list
, &tree
->list_head
);
240 node
= avl_find_rec(tree
->root
, new->key
, tree
->comp
, tree
->cmp_ptr
, &diff
);
244 while (!list_is_last(&last
->list
, &tree
->list_head
)) {
245 next
= avl_next(last
);
252 diff
= (*tree
->comp
) (new->key
, node
->key
, tree
->cmp_ptr
);
255 if (!tree
->allow_dups
)
260 avl_insert_after(tree
, last
, new);
264 if (node
->balance
== 1) {
265 avl_insert_before(tree
, node
, new);
273 if (node
->balance
== -1) {
274 avl_insert_after(tree
, last
, new);
283 avl_insert_before(tree
, node
, new);
288 post_insert(tree
, node
);
292 avl_insert_after(tree
, last
, new);
297 post_insert(tree
, node
);
302 * Remove a node from an avl tree
303 * @param tree pointer to tree
304 * @param node pointer to node
307 avl_delete(struct avl_tree
*tree
, struct avl_node
*node
)
309 struct avl_node
*next
;
310 struct avl_node
*parent
;
311 struct avl_node
*left
;
312 struct avl_node
*right
;
315 && !list_is_last(&node
->list
, &tree
->list_head
)
316 && !(next
= avl_next(node
))->leader
) {
318 next
->balance
= node
->balance
;
320 parent
= node
->parent
;
324 next
->parent
= parent
;
332 if (node
== parent
->left
)
336 parent
->right
= next
;
343 right
->parent
= next
;
347 avl_delete_worker(tree
, node
);
350 avl_remove(tree
, node
);
353 static struct avl_node
*
354 avl_find_rec(struct avl_node
*node
, const void *key
, avl_tree_comp comp
, void *cmp_ptr
, int *cmp_result
)
358 diff
= (*comp
) (key
, node
->key
, cmp_ptr
);
362 if (node
->left
!= NULL
)
363 return avl_find_rec(node
->left
, key
, comp
, cmp_ptr
, cmp_result
);
369 if (node
->right
!= NULL
)
370 return avl_find_rec(node
->right
, key
, comp
, cmp_ptr
, cmp_result
);
379 avl_rotate_right(struct avl_tree
*tree
, struct avl_node
*node
)
381 struct avl_node
*left
, *parent
;
384 parent
= node
->parent
;
386 left
->parent
= parent
;
393 if (parent
->left
== node
)
397 parent
->right
= left
;
400 node
->left
= left
->right
;
403 if (node
->left
!= NULL
)
404 node
->left
->parent
= node
;
406 node
->balance
+= 1 - avl_min(left
->balance
, 0);
407 left
->balance
+= 1 + avl_max(node
->balance
, 0);
411 avl_rotate_left(struct avl_tree
*tree
, struct avl_node
*node
)
413 struct avl_node
*right
, *parent
;
416 parent
= node
->parent
;
418 right
->parent
= parent
;
419 node
->parent
= right
;
425 if (parent
->left
== node
)
426 parent
->left
= right
;
429 parent
->right
= right
;
432 node
->right
= right
->left
;
435 if (node
->right
!= NULL
)
436 node
->right
->parent
= node
;
438 node
->balance
-= 1 + avl_max(right
->balance
, 0);
439 right
->balance
-= 1 - avl_min(node
->balance
, 0);
443 post_insert(struct avl_tree
*tree
, struct avl_node
*node
)
445 struct avl_node
*parent
= node
->parent
;
450 if (node
== parent
->left
) {
453 if (parent
->balance
== 0)
456 if (parent
->balance
== -1) {
457 post_insert(tree
, parent
);
461 if (node
->balance
== -1) {
462 avl_rotate_right(tree
, parent
);
466 avl_rotate_left(tree
, node
);
467 avl_rotate_right(tree
, node
->parent
->parent
);
473 if (parent
->balance
== 0)
476 if (parent
->balance
== 1) {
477 post_insert(tree
, parent
);
481 if (node
->balance
== 1) {
482 avl_rotate_left(tree
, parent
);
486 avl_rotate_right(tree
, node
);
487 avl_rotate_left(tree
, node
->parent
->parent
);
491 avl_insert_before(struct avl_tree
*tree
, struct avl_node
*pos_node
, struct avl_node
*node
)
493 list_add_tail(&node
->list
, &pos_node
->list
);
498 avl_insert_after(struct avl_tree
*tree
, struct avl_node
*pos_node
, struct avl_node
*node
)
500 list_add(&node
->list
, &pos_node
->list
);
505 avl_remove(struct avl_tree
*tree
, struct avl_node
*node
)
507 list_del(&node
->list
);
512 avl_post_delete(struct avl_tree
*tree
, struct avl_node
*node
)
514 struct avl_node
*parent
;
516 if ((parent
= node
->parent
) == NULL
)
519 if (node
== parent
->left
) {
522 if (parent
->balance
== 0) {
523 avl_post_delete(tree
, parent
);
527 if (parent
->balance
== 1)
530 if (parent
->right
->balance
== 0) {
531 avl_rotate_left(tree
, parent
);
535 if (parent
->right
->balance
== 1) {
536 avl_rotate_left(tree
, parent
);
537 avl_post_delete(tree
, parent
->parent
);
541 avl_rotate_right(tree
, parent
->right
);
542 avl_rotate_left(tree
, parent
);
543 avl_post_delete(tree
, parent
->parent
);
549 if (parent
->balance
== 0) {
550 avl_post_delete(tree
, parent
);
554 if (parent
->balance
== -1)
557 if (parent
->left
->balance
== 0) {
558 avl_rotate_right(tree
, parent
);
562 if (parent
->left
->balance
== -1) {
563 avl_rotate_right(tree
, parent
);
564 avl_post_delete(tree
, parent
->parent
);
568 avl_rotate_left(tree
, parent
->left
);
569 avl_rotate_right(tree
, parent
);
570 avl_post_delete(tree
, parent
->parent
);
573 static struct avl_node
*
574 avl_local_min(struct avl_node
*node
)
576 while (node
->left
!= NULL
)
583 static struct avl_node
*
584 avl_local_max(struct avl_node
*node
)
586 while (node
->right
!= NULL
)
594 avl_delete_worker(struct avl_tree
*tree
, struct avl_node
*node
)
596 struct avl_node
*parent
, *min
;
598 parent
= node
->parent
;
600 if (node
->left
== NULL
&& node
->right
== NULL
) {
601 if (parent
== NULL
) {
606 if (parent
->left
== node
) {
610 if (parent
->balance
== 1)
613 if (parent
->balance
== 0) {
614 avl_post_delete(tree
, parent
);
618 if (parent
->right
->balance
== 0) {
619 avl_rotate_left(tree
, parent
);
623 if (parent
->right
->balance
== 1) {
624 avl_rotate_left(tree
, parent
);
625 avl_post_delete(tree
, parent
->parent
);
629 avl_rotate_right(tree
, parent
->right
);
630 avl_rotate_left(tree
, parent
);
631 avl_post_delete(tree
, parent
->parent
);
635 if (parent
->right
== node
) {
636 parent
->right
= NULL
;
639 if (parent
->balance
== -1)
642 if (parent
->balance
== 0) {
643 avl_post_delete(tree
, parent
);
647 if (parent
->left
->balance
== 0) {
648 avl_rotate_right(tree
, parent
);
652 if (parent
->left
->balance
== -1) {
653 avl_rotate_right(tree
, parent
);
654 avl_post_delete(tree
, parent
->parent
);
658 avl_rotate_left(tree
, parent
->left
);
659 avl_rotate_right(tree
, parent
);
660 avl_post_delete(tree
, parent
->parent
);
665 if (node
->left
== NULL
) {
666 if (parent
== NULL
) {
667 tree
->root
= node
->right
;
668 node
->right
->parent
= NULL
;
673 node
->right
->parent
= parent
;
675 if (parent
->left
== node
)
676 parent
->left
= node
->right
;
679 parent
->right
= node
->right
;
681 avl_post_delete(tree
, node
->right
);
685 if (node
->right
== NULL
) {
686 if (parent
== NULL
) {
687 tree
->root
= node
->left
;
688 node
->left
->parent
= NULL
;
692 node
->left
->parent
= parent
;
694 if (parent
->left
== node
)
695 parent
->left
= node
->left
;
698 parent
->right
= node
->left
;
700 avl_post_delete(tree
, node
->left
);
704 min
= avl_local_min(node
->right
);
705 avl_delete_worker(tree
, min
);
706 parent
= node
->parent
;
708 min
->balance
= node
->balance
;
709 min
->parent
= parent
;
710 min
->left
= node
->left
;
711 min
->right
= node
->right
;
713 if (min
->left
!= NULL
)
714 min
->left
->parent
= min
;
716 if (min
->right
!= NULL
)
717 min
->right
->parent
= min
;
719 if (parent
== NULL
) {
724 if (parent
->left
== node
) {
735 * indent-tabs-mode: nil