/*
- * avl_tree.c
+ * avl_tree.c - intrusive, nonrecursive AVL tree data structure (self-balancing
+ * binary search tree), implementation file
*
- * Intrusive, nonrecursive AVL tree data structure (self-balancing binary search
- * tree), implementation file.
+ * The following copying information applies to this specific source code file:
*
- * Author: Eric Biggers
- * Year: 2014
+ * Written in 2014 by Eric Biggers <ebiggers3@gmail.com>
*
- * The author dedicates this file to the public domain.
- * You can do whatever you want with this file.
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide via the Creative Commons Zero 1.0 Universal Public Domain
+ * Dedication (the "CC0").
+ *
+ * This software 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 CC0 for more details.
+ *
+ * You should have received a copy of the CC0 along with this software; if not
+ * see <http://creativecommons.org/publicdomain/zero/1.0/>.
*/
-#include <wimlib/avl_tree.h>
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include "wimlib/avl_tree.h"
/* Starts an in-order traversal of the tree: returns the least-valued node, or
* NULL if the tree is empty. */
/* Continues an in-order traversal of the tree: returns the next-greatest-valued
* node, or NULL if there is none. */
struct avl_tree_node *
-avl_tree_next_in_order(const struct avl_tree_node *prev)
+avl_tree_next_in_order(const struct avl_tree_node *node)
{
const struct avl_tree_node *next;
- if (prev->right)
- for (next = prev->right;
+ if (node->right)
+ for (next = node->right;
next->left;
next = next->left)
;
else
- for (next = avl_get_parent(prev);
- next && prev == next->right;
- prev = next, next = avl_get_parent(next))
+ for (next = avl_get_parent(node);
+ next && node == next->right;
+ node = next, next = avl_get_parent(next))
;
return (struct avl_tree_node *)next;
}
+/* Continues a *reverse* in-order traversal of the tree: returns the
+ * previous-greatest-valued node, or NULL if there is none. */
+struct avl_tree_node *
+avl_tree_prev_in_order(const struct avl_tree_node *node)
+{
+ const struct avl_tree_node *prev;
+
+ if (node->left)
+ for (prev = node->left;
+ prev->right;
+ prev = prev->right)
+ ;
+ else
+ for (prev = avl_get_parent(node);
+ prev && node == prev->left;
+ node = prev, prev = avl_get_parent(prev))
+ ;
+ return (struct avl_tree_node *)prev;
+}
+
/* Starts a postorder traversal of the tree. */
struct avl_tree_node *
avl_tree_first_in_postorder(const struct avl_tree_node *root)
* specified AVL tree node.
* Note: for all calls of this, 'sign' is constant at compilation time,
* so the compiler can remove the conditional. */
-static AVL_INLINE struct avl_tree_node *
+static forceinline struct avl_tree_node *
avl_get_child(const struct avl_tree_node *parent, int sign)
{
if (sign < 0)
* specified AVL tree node.
* Note: for all calls of this, 'sign' is constant at compilation time,
* so the compiler can remove the conditional. */
-static AVL_INLINE void
+static forceinline void
avl_set_child(struct avl_tree_node *parent, int sign,
struct avl_tree_node *child)
{
}
/* Sets the parent and balance factor of the specified AVL tree node. */
-static AVL_INLINE void
+static forceinline void
avl_set_parent_balance(struct avl_tree_node *node, struct avl_tree_node *parent,
int balance_factor)
{
}
/* Sets the parent of the specified AVL tree node. */
-static AVL_INLINE void
+static forceinline void
avl_set_parent(struct avl_tree_node *node, struct avl_tree_node *parent)
{
node->parent_balance = (uintptr_t)parent | (node->parent_balance & 3);
/* Returns the balance factor of the specified AVL tree node --- that is, the
* height of its right subtree minus the height of its left subtree. */
-static AVL_INLINE int
+static forceinline int
avl_get_balance_factor(const struct avl_tree_node *node)
{
return (int)(node->parent_balance & 3) - 1;
}
-/* Sets the balance factor of the specified AVL tree node. This must be
- * -1, 0, or 1. */
-static AVL_INLINE void
-avl_set_balance_factor(struct avl_tree_node *node, int balance_factor)
-{
- node->parent_balance =
- (node->parent_balance & ~3) | (balance_factor + 1);
-}
-
/* Adds @amount to the balance factor of the specified AVL tree node.
* The caller must ensure this still results in a valid balance factor
* (-1, 0, or 1). */
-static AVL_INLINE void
+static forceinline void
avl_adjust_balance_factor(struct avl_tree_node *node, int amount)
{
node->parent_balance += amount;
}
-static AVL_INLINE void
+static forceinline void
avl_replace_child(struct avl_tree_node **root_ptr,
struct avl_tree_node *parent,
struct avl_tree_node *old_child,
*
* This updates pointers but not balance factors!
*/
-static AVL_INLINE void
+static forceinline void
avl_rotate(struct avl_tree_node ** const root_ptr,
struct avl_tree_node * const A, const int sign)
{
* See comment in avl_handle_subtree_growth() for explanation of balance
* factor updates.
*/
-static AVL_INLINE struct avl_tree_node *
+static forceinline struct avl_tree_node *
avl_do_double_rotate(struct avl_tree_node ** const root_ptr,
struct avl_tree_node * const B,
struct avl_tree_node * const A, const int sign)
* Indeed, a single node insertion cannot require that more than one
* (single or double) rotation be done.
*/
-static AVL_INLINE bool
+static forceinline bool
avl_handle_subtree_growth(struct avl_tree_node ** const root_ptr,
struct avl_tree_node * const node,
struct avl_tree_node * const parent,
*/
avl_rotate(root_ptr, parent, -sign);
- /* Equivalent to:
- * avl_set_balance_factor(parent, 0); */
+ /* Equivalent to setting @parent's balance factor to 0. */
avl_adjust_balance_factor(parent, -sign); /* A */
- /* Equivalent to:
- * avl_set_balance_factor(node, 0); */
+ /* Equivalent to setting @node's balance factor to 0. */
avl_adjust_balance_factor(node, -sign); /* B */
} else {
/* @node (B below) is heavy in the direction opposite
* decreased in height by 1. Also in the latter case, *left_deleted_ret
* will be set.
*/
-static AVL_INLINE struct avl_tree_node *
+static forceinline struct avl_tree_node *
avl_handle_subtree_shrink(struct avl_tree_node ** const root_ptr,
struct avl_tree_node *parent,
const int sign,
/* Swaps node X, which must have 2 children, with its in-order successor, then
* unlinks node X. Returns the parent of X just before unlinking, without its
* balance factor having been updated to account for the unlink. */
-static AVL_INLINE struct avl_tree_node *
+static forceinline struct avl_tree_node *
avl_tree_swap_with_successor(struct avl_tree_node **root_ptr,
struct avl_tree_node *X,
bool *left_deleted_ret)
git://wimlib.net / wimlib / blobdiff