--- /dev/null
+/*
+ avl_tree.h -- header file for avl_tree.c
+ Copyright (C) 1998 Michael H. Buselli
+ 2000-2005 Ivo Timmermans,
+ 2000-2006 Guus Sliepen <guus@tinc-vpn.org>
+ 2000-2005 Wessel Dankers <wsl@tinc-vpn.org>
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write to the Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+ Original AVL tree library by Michael H. Buselli <cosine@cosine.org>.
+
+ Modified 2000-11-28 by Wessel Dankers <wsl@tinc-vpn.org> to use counts
+ instead of depths, to add the ->next and ->prev and to generally obfuscate
+ the code. Mail me if you found a bug.
+
+ Cleaned up and incorporated some of the ideas from the red-black tree
+ library for inclusion into tinc (http://www.tinc-vpn.org/) by
+ Guus Sliepen <guus@tinc-vpn.org>.
+*/
+
+
+#ifndef __AVL_TREE_H__
+#define __AVL_TREE_H__
+
+#ifndef AVL_DEPTH
+#ifndef AVL_COUNT
+#define AVL_DEPTH
+#endif
+#endif
+
+typedef struct avl_node_t {
+
+ /* Linked list part */
+
+ struct avl_node_t *next;
+ struct avl_node_t *prev;
+
+ /* Tree part */
+
+ struct avl_node_t *parent;
+ struct avl_node_t *left;
+ struct avl_node_t *right;
+
+#ifdef AVL_COUNT
+ unsigned int count;
+#endif
+#ifdef AVL_DEPTH
+ unsigned char depth;
+#endif
+
+ /* Payload */
+
+ void *data;
+
+} avl_node_t;
+
+typedef int (*avl_compare_t)(const void *, const void *);
+typedef void (*avl_action_t)(const void *);
+typedef void (*avl_action_node_t)(const avl_node_t *);
+
+typedef struct avl_tree_t {
+
+ /* Linked list part */
+
+ avl_node_t *head;
+ avl_node_t *tail;
+
+ /* Tree part */
+
+ avl_node_t *root;
+
+ avl_compare_t compare;
+ avl_action_t delete;
+
+} avl_tree_t;
+
+/* (De)constructors */
+
+extern avl_tree_t *avl_alloc_tree(avl_compare_t, avl_action_t);
+extern void avl_free_tree(avl_tree_t *);
+
+extern avl_node_t *avl_alloc_node(void);
+extern void avl_free_node(avl_tree_t *tree, avl_node_t *);
+
+/* Insertion and deletion */
+
+extern avl_node_t *avl_insert(avl_tree_t *, void *);
+extern avl_node_t *avl_insert_node(avl_tree_t *, avl_node_t *);
+
+extern void avl_insert_top(avl_tree_t *, avl_node_t *);
+extern void avl_insert_before(avl_tree_t *, avl_node_t *, avl_node_t *);
+extern void avl_insert_after(avl_tree_t *, avl_node_t *, avl_node_t *);
+
+extern avl_node_t *avl_unlink(avl_tree_t *, void *);
+extern void avl_unlink_node(avl_tree_t *tree, avl_node_t *);
+extern void avl_delete(avl_tree_t *, void *);
+extern void avl_delete_node(avl_tree_t *, avl_node_t *);
+
+/* Fast tree cleanup */
+
+extern void avl_delete_tree(avl_tree_t *);
+
+/* Searching */
+
+extern void *avl_search(const avl_tree_t *, const void *);
+extern void *avl_search_closest(const avl_tree_t *, const void *, int *);
+extern void *avl_search_closest_smaller(const avl_tree_t *, const void *);
+extern void *avl_search_closest_greater(const avl_tree_t *, const void *);
+
+extern avl_node_t *avl_search_node(const avl_tree_t *, const void *);
+extern avl_node_t *avl_search_closest_node(const avl_tree_t *, const void *, int *);
+extern avl_node_t *avl_search_closest_smaller_node(const avl_tree_t *, const void *);
+extern avl_node_t *avl_search_closest_greater_node(const avl_tree_t *, const void *);
+
+/* Tree walking */
+
+extern void avl_foreach(const avl_tree_t *, avl_action_t);
+extern void avl_foreach_node(const avl_tree_t *, avl_action_t);
+
+/* Indexing */
+
+#ifdef AVL_COUNT
+extern unsigned int avl_count(const avl_tree_t *);
+extern avl_node_t *avl_get_node(const avl_tree_t *, unsigned int);
+extern unsigned int avl_index(const avl_node_t *);
+#endif
+#ifdef AVL_DEPTH
+extern unsigned int avl_depth(const avl_tree_t *);
+#endif
+
+#endif /* __AVL_TREE_H__ */