/*
- * avl_tree.h
+ * avl_tree.h - intrusive, nonrecursive AVL tree data structure (self-balancing
+ * binary search tree), header file
*
- * Intrusive, nonrecursive AVL tree data structure (self-balancing binary search
- * tree), header file.
+ * Copyright 2022 Eric Biggers
*
- * Author: Eric Biggers
- * Year: 2014
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following
+ * conditions:
*
- * This file is placed into the public domain. You can do whatever you want
- * with it.
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef _AVL_TREE_H_
#define _AVL_TREE_H_
-#include <stdbool.h>
-#include <stddef.h>
-#include <inttypes.h> /* for uintptr_t */
-
-#ifdef __GNUC__
-# define AVL_INLINE inline __attribute__((always_inline))
-#else
-# define AVL_INLINE inline
-# warning "AVL tree functions may not be inlined as intended"
-#endif
+#include "wimlib/types.h"
+#define AVL_INLINE forceinline
/* Node in an AVL tree. Embed this in some other data structure. */
struct avl_tree_node {
return (struct avl_tree_node *)(node->parent_balance & ~3);
}
-/* Marks the specified AVL tree node as unlinked from any tree. */
-static AVL_INLINE void
-avl_tree_node_set_unlinked(struct avl_tree_node *node)
-{
- node->parent_balance = (uintptr_t)node;
-}
-
-/* Returns true iff the specified AVL tree node has been marked with
- * avl_tree_node_set_unlinked() and has not subsequently been inserted into a
- * tree. */
-static AVL_INLINE bool
-avl_tree_node_is_unlinked(const struct avl_tree_node *node)
-{
- return node->parent_balance == (uintptr_t)node;
-}
-
/* (Internal use only) */
-extern void
+void
avl_tree_rebalance_after_insert(struct avl_tree_node **root_ptr,
struct avl_tree_node *inserted);
*
* Returns a pointer to the AVL tree node of the resulting item, or NULL if the
* item was not found.
+ *
+ * Example:
+ *
+ * struct int_wrapper {
+ * int data;
+ * struct avl_tree_node index_node;
+ * };
+ *
+ * static int _avl_cmp_int_to_node(const void *intptr,
+ * const struct avl_tree_node *nodeptr)
+ * {
+ * int n1 = *(const int *)intptr;
+ * int n2 = avl_tree_entry(nodeptr, struct int_wrapper, index_node)->data;
+ * if (n1 < n2)
+ * return -1;
+ * else if (n1 > n2)
+ * return 1;
+ * else
+ * return 0;
+ * }
+ *
+ * bool contains_int(struct avl_tree_node *root, int n)
+ * {
+ * struct avl_tree_node *result;
+ *
+ * result = avl_tree_lookup(root, &n, _avl_cmp_int_to_node);
+ * return result ? true : false;
+ * }
*/
static AVL_INLINE struct avl_tree_node *
avl_tree_lookup(const struct avl_tree_node *root,
int (*cmp)(const struct avl_tree_node *,
const struct avl_tree_node *))
{
- return avl_tree_lookup(root,
- (const void *)node,
- (int (*) (const void *,
- const struct avl_tree_node *))cmp);
+ const struct avl_tree_node *cur = root;
+
+ while (cur) {
+ int res = (*cmp)(node, cur);
+ if (res < 0)
+ cur = cur->left;
+ else if (res > 0)
+ cur = cur->right;
+ else
+ break;
+ }
+ return (struct avl_tree_node*)cur;
}
/*
* @item and returns NULL. Otherwise does nothing and returns a pointer to the
* AVL tree node embedded in the previously-inserted item which compared equal
* to @item.
+ *
+ * Example:
+ *
+ * struct int_wrapper {
+ * int data;
+ * struct avl_tree_node index_node;
+ * };
+ *
+ * #define GET_DATA(i) avl_tree_entry((i), struct int_wrapper, index_node)->data
+ *
+ * static int _avl_cmp_ints(const struct avl_tree_node *node1,
+ * const struct avl_tree_node *node2)
+ * {
+ * int n1 = GET_DATA(node1);
+ * int n2 = GET_DATA(node2);
+ * if (n1 < n2)
+ * return -1;
+ * else if (n1 > n2)
+ * return 1;
+ * else
+ * return 0;
+ * }
+ *
+ * bool insert_int(struct avl_tree_node **root_ptr, int data)
+ * {
+ * struct int_wrapper *i = malloc(sizeof(struct int_wrapper));
+ * i->data = data;
+ * if (avl_tree_insert(root_ptr, &i->index_node, _avl_cmp_ints)) {
+ * // Duplicate.
+ * free(i);
+ * return false;
+ * }
+ * return true;
+ * }
*/
static AVL_INLINE struct avl_tree_node *
avl_tree_insert(struct avl_tree_node **root_ptr,
/* Removes an item from the specified AVL tree.
* See implementation for details. */
-extern void
+void
avl_tree_remove(struct avl_tree_node **root_ptr, struct avl_tree_node *node);
/* Nonrecursive AVL tree traversal functions */
-extern struct avl_tree_node *
+struct avl_tree_node *
avl_tree_first_in_order(const struct avl_tree_node *root);
-extern struct avl_tree_node *
-avl_tree_next_in_order(const struct avl_tree_node *prev);
+struct avl_tree_node *
+avl_tree_last_in_order(const struct avl_tree_node *root);
-extern struct avl_tree_node *
+struct avl_tree_node *
+avl_tree_next_in_order(const struct avl_tree_node *node);
+
+struct avl_tree_node *
+avl_tree_prev_in_order(const struct avl_tree_node *node);
+
+struct avl_tree_node *
avl_tree_first_in_postorder(const struct avl_tree_node *root);
-extern struct avl_tree_node *
+struct avl_tree_node *
avl_tree_next_in_postorder(const struct avl_tree_node *prev,
const struct avl_tree_node *prev_parent);
+/*
+ * Iterate through the nodes in an AVL tree in sorted order.
+ * You may not modify the tree during the iteration.
+ *
+ * @child_struct
+ * Variable that will receive a pointer to each struct inserted into the
+ * tree.
+ * @root
+ * Root of the AVL tree.
+ * @struct_name
+ * Type of *child_struct.
+ * @struct_member
+ * Member of @struct_name type that is the AVL tree node.
+ *
+ * Example:
+ *
+ * struct int_wrapper {
+ * int data;
+ * struct avl_tree_node index_node;
+ * };
+ *
+ * void print_ints(struct avl_tree_node *root)
+ * {
+ * struct int_wrapper *i;
+ *
+ * avl_tree_for_each_in_order(i, root, struct int_wrapper, index_node)
+ * printf("%d\n", i->data);
+ * }
+ */
+#define avl_tree_for_each_in_order(child_struct, root, \
+ struct_name, struct_member) \
+ for (struct avl_tree_node *_cur = \
+ avl_tree_first_in_order(root); \
+ _cur && ((child_struct) = \
+ avl_tree_entry(_cur, struct_name, \
+ struct_member), 1); \
+ _cur = avl_tree_next_in_order(_cur))
+
+/*
+ * Like avl_tree_for_each_in_order(), but uses the reverse order.
+ */
+#define avl_tree_for_each_in_reverse_order(child_struct, root, \
+ struct_name, struct_member) \
+ for (struct avl_tree_node *_cur = \
+ avl_tree_last_in_order(root); \
+ _cur && ((child_struct) = \
+ avl_tree_entry(_cur, struct_name, \
+ struct_member), 1); \
+ _cur = avl_tree_prev_in_order(_cur))
+
+/*
+ * Like avl_tree_for_each_in_order(), but iterates through the nodes in
+ * postorder, so the current node may be deleted or freed.
+ */
+#define avl_tree_for_each_in_postorder(child_struct, root, \
+ struct_name, struct_member) \
+ for (struct avl_tree_node *_cur = \
+ avl_tree_first_in_postorder(root), *_parent; \
+ _cur && ((child_struct) = \
+ avl_tree_entry(_cur, struct_name, \
+ struct_member), 1) \
+ && (_parent = avl_get_parent(_cur), 1); \
+ _cur = avl_tree_next_in_postorder(_cur, _parent))
+
#endif /* _AVL_TREE_H_ */
git://wimlib.net / wimlib / blobdiff