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.
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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29 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
31 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32 * POSSIBILITY OF SUCH DAMAGE.
34 * Visit http://www.olsr.org/git for more information.
36 * If you find this software useful feel free to make a donation
37 * to the project. For more information see the website or contact
38 * the copyright holders.
50 #define list_merge(_head, _list) list_merge(_list, _head)
51 #define list_is_last(_head, _list) list_is_last(_list, _head)
52 #define list_is_first(_head, _list) list_is_first(_list, _head)
55 * internal type save inline function to calculate the maximum of
56 * to integers without macro implementation.
58 * @param x first parameter of maximum function
59 * @param y second parameter of maximum function
60 * @return largest integer of both parameters
62 static inline int avl_max(int x
, int y
) {
67 * internal type save inline function to calculate the minimum of
68 * to integers without macro implementation.
70 * @param x first parameter of minimum function
71 * @param y second parameter of minimum function
72 * @return smallest integer of both parameters
74 static inline int avl_min(int x
, int y
) {
78 static struct avl_node
*
79 avl_find_rec(struct avl_node
*node
, const void *key
, avl_tree_comp comp
, void *ptr
, int *cmp_result
);
80 static void avl_insert_before(struct avl_tree
*tree
, struct avl_node
*pos_node
, struct avl_node
*node
);
81 static void avl_insert_after(struct avl_tree
*tree
, struct avl_node
*pos_node
, struct avl_node
*node
);
82 static void post_insert(struct avl_tree
*tree
, struct avl_node
*node
);
83 static void avl_delete_worker(struct avl_tree
*tree
, struct avl_node
*node
);
84 static void avl_remove(struct avl_tree
*tree
, struct avl_node
*node
);
87 * Initialize a new avl_tree struct
88 * @param tree pointer to avl-tree
89 * @param comp pointer to comparator for the tree
90 * @param allow_dups true if the tree allows multiple
91 * elements with the same
92 * @param ptr custom parameter for comparator
95 avl_init(struct avl_tree
*tree
, avl_tree_comp comp
, bool allow_dups
, void *ptr
)
97 list_init_head(&tree
->list_head
);
101 tree
->allow_dups
= allow_dups
;
106 * Finds a node in an avl-tree with a certain key
107 * @param tree pointer to avl-tree
108 * @param key pointer to key
109 * @return pointer to avl-node with key, NULL if no node with
113 avl_find(const struct avl_tree
*tree
, const void *key
)
115 struct avl_node
*node
;
118 if (tree
->root
== NULL
)
121 node
= avl_find_rec(tree
->root
, key
, tree
->comp
, tree
->cmp_ptr
, &diff
);
123 return diff
== 0 ? node
: NULL
;
127 * Finds the last node in an avl-tree with a key less or equal
128 * than the specified key
129 * @param tree pointer to avl-tree
130 * @param key pointer to specified key
131 * @return pointer to avl-node, NULL if no node with
132 * key less or equal specified key exists.
135 avl_find_lessequal(const struct avl_tree
*tree
, const void *key
) {
136 struct avl_node
*node
, *next
;
139 if (tree
->root
== NULL
)
142 node
= avl_find_rec(tree
->root
, key
, tree
->comp
, tree
->cmp_ptr
, &diff
);
144 /* go left as long as key<node.key */
146 if (list_is_first(&tree
->list_head
, &node
->list
)) {
150 node
= (struct avl_node
*)node
->list
.prev
;
151 diff
= (*tree
->comp
) (key
, node
->key
, tree
->cmp_ptr
);
154 /* go right as long as key>=next_node.key */
158 if (list_is_last(&tree
->list_head
, &node
->list
)) {
162 next
= (struct avl_node
*)node
->list
.next
;
163 diff
= (*tree
->comp
) (key
, next
->key
, tree
->cmp_ptr
);
169 * Finds the first node in an avl-tree with a key greater or equal
170 * than the specified key
171 * @param tree pointer to avl-tree
172 * @param key pointer to specified key
173 * @return pointer to avl-node, NULL if no node with
174 * key greater or equal specified key exists.
177 avl_find_greaterequal(const struct avl_tree
*tree
, const void *key
) {
178 struct avl_node
*node
, *next
;
181 if (tree
->root
== NULL
)
184 node
= avl_find_rec(tree
->root
, key
, tree
->comp
, tree
->cmp_ptr
, &diff
);
186 /* go right as long as key>node.key */
188 if (list_is_last(&tree
->list_head
, &node
->list
)) {
192 node
= (struct avl_node
*)node
->list
.next
;
193 diff
= (*tree
->comp
) (key
, node
->key
, tree
->cmp_ptr
);
196 /* go left as long as key<=next_node.key */
200 if (list_is_first(&tree
->list_head
, &node
->list
)) {
204 next
= (struct avl_node
*)node
->list
.prev
;
205 diff
= (*tree
->comp
) (key
, next
->key
, tree
->cmp_ptr
);
211 * Inserts an avl_node into a tree
212 * @param tree pointer to tree
213 * @param new pointer to node
214 * @return 0 if node was inserted successfully, -1 if it was not inserted
215 * because of a key collision
218 avl_insert(struct avl_tree
*tree
, struct avl_node
*new)
220 struct avl_node
*node
, *next
, *last
;
231 if (tree
->root
== NULL
) {
232 list_add_head(&tree
->list_head
, &new->list
);
238 node
= avl_find_rec(tree
->root
, new->key
, tree
->comp
, tree
->cmp_ptr
, &diff
);
242 while (!list_is_last(&tree
->list_head
, &last
->list
)) {
243 next
= list_next_element(last
, list
);
250 diff
= (*tree
->comp
) (new->key
, node
->key
, tree
->cmp_ptr
);
253 if (!tree
->allow_dups
)
258 avl_insert_after(tree
, last
, new);
262 if (node
->balance
== 1) {
263 avl_insert_before(tree
, node
, new);
271 if (node
->balance
== -1) {
272 avl_insert_after(tree
, last
, new);
281 avl_insert_before(tree
, node
, new);
286 post_insert(tree
, node
);
290 avl_insert_after(tree
, last
, new);
295 post_insert(tree
, node
);
300 * Remove a node from an avl tree
301 * @param tree pointer to tree
302 * @param node pointer to node
305 avl_delete(struct avl_tree
*tree
, struct avl_node
*node
)
307 struct avl_node
*next
;
308 struct avl_node
*parent
;
309 struct avl_node
*left
;
310 struct avl_node
*right
;
313 && !list_is_last(&tree
->list_head
, &node
->list
)
314 && !(next
= list_next_element(node
, list
))->leader
) {
316 next
->balance
= node
->balance
;
318 parent
= node
->parent
;
322 next
->parent
= parent
;
330 if (node
== parent
->left
)
334 parent
->right
= next
;
341 right
->parent
= next
;
345 avl_delete_worker(tree
, node
);
348 avl_remove(tree
, node
);
351 static struct avl_node
*
352 avl_find_rec(struct avl_node
*node
, const void *key
, avl_tree_comp comp
, void *cmp_ptr
, int *cmp_result
)
356 diff
= (*comp
) (key
, node
->key
, cmp_ptr
);
360 if (node
->left
!= NULL
)
361 return avl_find_rec(node
->left
, key
, comp
, cmp_ptr
, cmp_result
);
367 if (node
->right
!= NULL
)
368 return avl_find_rec(node
->right
, key
, comp
, cmp_ptr
, cmp_result
);
377 avl_rotate_right(struct avl_tree
*tree
, struct avl_node
*node
)
379 struct avl_node
*left
, *parent
;
382 parent
= node
->parent
;
384 left
->parent
= parent
;
391 if (parent
->left
== node
)
395 parent
->right
= left
;
398 node
->left
= left
->right
;
401 if (node
->left
!= NULL
)
402 node
->left
->parent
= node
;
404 node
->balance
+= 1 - avl_min(left
->balance
, 0);
405 left
->balance
+= 1 + avl_max(node
->balance
, 0);
409 avl_rotate_left(struct avl_tree
*tree
, struct avl_node
*node
)
411 struct avl_node
*right
, *parent
;
414 parent
= node
->parent
;
416 right
->parent
= parent
;
417 node
->parent
= right
;
423 if (parent
->left
== node
)
424 parent
->left
= right
;
427 parent
->right
= right
;
430 node
->right
= right
->left
;
433 if (node
->right
!= NULL
)
434 node
->right
->parent
= node
;
436 node
->balance
-= 1 + avl_max(right
->balance
, 0);
437 right
->balance
-= 1 - avl_min(node
->balance
, 0);
441 post_insert(struct avl_tree
*tree
, struct avl_node
*node
)
443 struct avl_node
*parent
= node
->parent
;
448 if (node
== parent
->left
) {
451 if (parent
->balance
== 0)
454 if (parent
->balance
== -1) {
455 post_insert(tree
, parent
);
459 if (node
->balance
== -1) {
460 avl_rotate_right(tree
, parent
);
464 avl_rotate_left(tree
, node
);
465 avl_rotate_right(tree
, node
->parent
->parent
);
471 if (parent
->balance
== 0)
474 if (parent
->balance
== 1) {
475 post_insert(tree
, parent
);
479 if (node
->balance
== 1) {
480 avl_rotate_left(tree
, parent
);
484 avl_rotate_right(tree
, node
);
485 avl_rotate_left(tree
, node
->parent
->parent
);
489 avl_insert_before(struct avl_tree
*tree
, struct avl_node
*pos_node
, struct avl_node
*node
)
491 list_add_before(&pos_node
->list
, &node
->list
);
496 avl_insert_after(struct avl_tree
*tree
, struct avl_node
*pos_node
, struct avl_node
*node
)
498 list_add_after(&pos_node
->list
, &node
->list
);
503 avl_remove(struct avl_tree
*tree
, struct avl_node
*node
)
505 list_remove(&node
->list
);
510 avl_post_delete(struct avl_tree
*tree
, struct avl_node
*node
)
512 struct avl_node
*parent
;
514 if ((parent
= node
->parent
) == NULL
)
517 if (node
== parent
->left
) {
520 if (parent
->balance
== 0) {
521 avl_post_delete(tree
, parent
);
525 if (parent
->balance
== 1)
528 if (parent
->right
->balance
== 0) {
529 avl_rotate_left(tree
, parent
);
533 if (parent
->right
->balance
== 1) {
534 avl_rotate_left(tree
, parent
);
535 avl_post_delete(tree
, parent
->parent
);
539 avl_rotate_right(tree
, parent
->right
);
540 avl_rotate_left(tree
, parent
);
541 avl_post_delete(tree
, parent
->parent
);
547 if (parent
->balance
== 0) {
548 avl_post_delete(tree
, parent
);
552 if (parent
->balance
== -1)
555 if (parent
->left
->balance
== 0) {
556 avl_rotate_right(tree
, parent
);
560 if (parent
->left
->balance
== -1) {
561 avl_rotate_right(tree
, parent
);
562 avl_post_delete(tree
, parent
->parent
);
566 avl_rotate_left(tree
, parent
->left
);
567 avl_rotate_right(tree
, parent
);
568 avl_post_delete(tree
, parent
->parent
);
571 static struct avl_node
*
572 avl_local_min(struct avl_node
*node
)
574 while (node
->left
!= NULL
)
581 static struct avl_node
*
582 avl_local_max(struct avl_node
*node
)
584 while (node
->right
!= NULL
)
592 avl_delete_worker(struct avl_tree
*tree
, struct avl_node
*node
)
594 struct avl_node
*parent
, *min
;
596 parent
= node
->parent
;
598 if (node
->left
== NULL
&& node
->right
== NULL
) {
599 if (parent
== NULL
) {
604 if (parent
->left
== node
) {
608 if (parent
->balance
== 1)
611 if (parent
->balance
== 0) {
612 avl_post_delete(tree
, parent
);
616 if (parent
->right
->balance
== 0) {
617 avl_rotate_left(tree
, parent
);
621 if (parent
->right
->balance
== 1) {
622 avl_rotate_left(tree
, parent
);
623 avl_post_delete(tree
, parent
->parent
);
627 avl_rotate_right(tree
, parent
->right
);
628 avl_rotate_left(tree
, parent
);
629 avl_post_delete(tree
, parent
->parent
);
633 if (parent
->right
== node
) {
634 parent
->right
= NULL
;
637 if (parent
->balance
== -1)
640 if (parent
->balance
== 0) {
641 avl_post_delete(tree
, parent
);
645 if (parent
->left
->balance
== 0) {
646 avl_rotate_right(tree
, parent
);
650 if (parent
->left
->balance
== -1) {
651 avl_rotate_right(tree
, parent
);
652 avl_post_delete(tree
, parent
->parent
);
656 avl_rotate_left(tree
, parent
->left
);
657 avl_rotate_right(tree
, parent
);
658 avl_post_delete(tree
, parent
->parent
);
663 if (node
->left
== NULL
) {
664 if (parent
== NULL
) {
665 tree
->root
= node
->right
;
666 node
->right
->parent
= NULL
;
670 node
->right
->parent
= parent
;
672 if (parent
->left
== node
)
673 parent
->left
= node
->right
;
676 parent
->right
= node
->right
;
678 avl_post_delete(tree
, node
->right
);
682 if (node
->right
== NULL
) {
683 if (parent
== NULL
) {
684 tree
->root
= node
->left
;
685 node
->left
->parent
= NULL
;
689 node
->left
->parent
= parent
;
691 if (parent
->left
== node
)
692 parent
->left
= node
->left
;
695 parent
->right
= node
->left
;
697 avl_post_delete(tree
, node
->left
);
701 min
= avl_local_min(node
->right
);
702 avl_delete_worker(tree
, min
);
703 parent
= node
->parent
;
705 min
->balance
= node
->balance
;
706 min
->parent
= parent
;
707 min
->left
= node
->left
;
708 min
->right
= node
->right
;
710 if (min
->left
!= NULL
)
711 min
->left
->parent
= min
;
713 if (min
->right
!= NULL
)
714 min
->right
->parent
= min
;
716 if (parent
== NULL
) {
721 if (parent
->left
== node
) {
732 * indent-tabs-mode: nil