- AVL tree routines: faster than RBL, and also more stable.

[tinc] / lib / avl_tree.h

diff --git a/lib/avl_tree.h b/lib/avl_tree.h
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+++ b/lib/avl_tree.h
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+/*
+    avl_tree.h -- header file for avl_tree.c
+    Copyright (C) 1998 Michael H. Buselli
+                  2000 Ivo Timmermans <itimmermans@bigfoot.com>,
+                  2000 Guus Sliepen <guus@sliepen.warande.net>
+                  2000 Wessel Dankers <wsl@nl.linux.org>
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2 of the License, or (at your option) any later version.
+
+    This library 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
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
+
+    Original AVL tree library by Michael H. Buselli <cosine@cosine.org>.
+
+    Modified 2000-11-28 by Wessel Dankers <wsl@nl.linux.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://tinc.nl.linux.org) by
+    Guus Sliepen <guus@sliepen.warande.net>.
+
+    $Id: avl_tree.h,v 1.1.2.1 2001/01/05 23:50:56 guus Exp $
+*/
+
+
+#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(avl_tree_t *, avl_action_t);
+extern void avl_foreach_node(avl_tree_t *, avl_action_t);
+
+/* Indexing */
+
+#ifdef AVL_COUNT
+extern unsigned int avl_count(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(avl_tree_t *);
+#endif
+
+#endif /* __AVL_TREE_H__ */