+++ /dev/null
-/*
- * CDDL HEADER START
- *
- * The contents of this file are subject to the terms of the
- * Common Development and Distribution License (the "License").
- * You may not use this file except in compliance with the License.
- *
- * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
- * or http://www.opensolaris.org/os/licensing.
- * See the License for the specific language governing permissions
- * and limitations under the License.
- *
- * When distributing Covered Code, include this CDDL HEADER in each
- * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
- * If applicable, add the following below this CDDL HEADER, with the
- * fields enclosed by brackets "[]" replaced with your own identifying
- * information: Portions Copyright [yyyy] [name of copyright owner]
- *
- * CDDL HEADER END
- */
-/*
- * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
- * Use is subject to license terms.
- */
-
-#ifndef _AVL_H
-#define _AVL_H
-
-/*
- * This is a private header file. Applications should not directly include
- * this file.
- */
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#include <sys/types.h>
-#include <sys/avl_impl.h>
-
-/*
- * This is a generic implemenatation of AVL trees for use in the Solaris kernel.
- * The interfaces provide an efficient way of implementing an ordered set of
- * data structures.
- *
- * AVL trees provide an alternative to using an ordered linked list. Using AVL
- * trees will usually be faster, however they requires more storage. An ordered
- * linked list in general requires 2 pointers in each data structure. The
- * AVL tree implementation uses 3 pointers. The following chart gives the
- * approximate performance of operations with the different approaches:
- *
- * Operation Link List AVL tree
- * --------- -------- --------
- * lookup O(n) O(log(n))
- *
- * insert 1 node constant constant
- *
- * delete 1 node constant between constant and O(log(n))
- *
- * delete all nodes O(n) O(n)
- *
- * visit the next
- * or prev node constant between constant and O(log(n))
- *
- *
- * The data structure nodes are anchored at an "avl_tree_t" (the equivalent
- * of a list header) and the individual nodes will have a field of
- * type "avl_node_t" (corresponding to list pointers).
- *
- * The type "avl_index_t" is used to indicate a position in the list for
- * certain calls.
- *
- * The usage scenario is generally:
- *
- * 1. Create the list/tree with: avl_create()
- *
- * followed by any mixture of:
- *
- * 2a. Insert nodes with: avl_add(), or avl_find() and avl_insert()
- *
- * 2b. Visited elements with:
- * avl_first() - returns the lowest valued node
- * avl_last() - returns the highest valued node
- * AVL_NEXT() - given a node go to next higher one
- * AVL_PREV() - given a node go to previous lower one
- *
- * 2c. Find the node with the closest value either less than or greater
- * than a given value with avl_nearest().
- *
- * 2d. Remove individual nodes from the list/tree with avl_remove().
- *
- * and finally when the list is being destroyed
- *
- * 3. Use avl_destroy_nodes() to quickly process/free up any remaining nodes.
- * Note that once you use avl_destroy_nodes(), you can no longer
- * use any routine except avl_destroy_nodes() and avl_destoy().
- *
- * 4. Use avl_destroy() to destroy the AVL tree itself.
- *
- * Any locking for multiple thread access is up to the user to provide, just
- * as is needed for any linked list implementation.
- */
-
-
-/*
- * Type used for the root of the AVL tree.
- */
-typedef struct avl_tree avl_tree_t;
-
-/*
- * The data nodes in the AVL tree must have a field of this type.
- */
-typedef struct avl_node avl_node_t;
-
-/*
- * An opaque type used to locate a position in the tree where a node
- * would be inserted.
- */
-typedef uintptr_t avl_index_t;
-
-
-/*
- * Direction constants used for avl_nearest().
- */
-#define AVL_BEFORE (0)
-#define AVL_AFTER (1)
-
-
-/*
- * Prototypes
- *
- * Where not otherwise mentioned, "void *" arguments are a pointer to the
- * user data structure which must contain a field of type avl_node_t.
- *
- * Also assume the user data structures looks like:
- * stuct my_type {
- * ...
- * avl_node_t my_link;
- * ...
- * };
- */
-
-/*
- * Initialize an AVL tree. Arguments are:
- *
- * tree - the tree to be initialized
- * compar - function to compare two nodes, it must return exactly: -1, 0, or +1
- * -1 for <, 0 for ==, and +1 for >
- * size - the value of sizeof(struct my_type)
- * offset - the value of OFFSETOF(struct my_type, my_link)
- */
-extern void avl_create(avl_tree_t *tree,
- int (*compar) (const void *, const void *), size_t size, size_t offset);
-
-
-/*
- * Find a node with a matching value in the tree. Returns the matching node
- * found. If not found, it returns NULL and then if "where" is not NULL it sets
- * "where" for use with avl_insert() or avl_nearest().
- *
- * node - node that has the value being looked for
- * where - position for use with avl_nearest() or avl_insert(), may be NULL
- */
-extern void *avl_find(avl_tree_t *tree, const void *node, avl_index_t *where);
-
-/*
- * Insert a node into the tree.
- *
- * node - the node to insert
- * where - position as returned from avl_find()
- */
-extern void avl_insert(avl_tree_t *tree, void *node, avl_index_t where);
-
-/*
- * Insert "new_data" in "tree" in the given "direction" either after
- * or before the data "here".
- *
- * This might be usefull for avl clients caching recently accessed
- * data to avoid doing avl_find() again for insertion.
- *
- * new_data - new data to insert
- * here - existing node in "tree"
- * direction - either AVL_AFTER or AVL_BEFORE the data "here".
- */
-extern void avl_insert_here(avl_tree_t *tree, void *new_data, void *here,
- int direction);
-
-
-/*
- * Return the first or last valued node in the tree. Will return NULL
- * if the tree is empty.
- *
- */
-extern void *avl_first(avl_tree_t *tree);
-extern void *avl_last(avl_tree_t *tree);
-
-
-/*
- * Return the next or previous valued node in the tree.
- * AVL_NEXT() will return NULL if at the last node.
- * AVL_PREV() will return NULL if at the first node.
- *
- * node - the node from which the next or previous node is found
- */
-#define AVL_NEXT(tree, node) avl_walk(tree, node, AVL_AFTER)
-#define AVL_PREV(tree, node) avl_walk(tree, node, AVL_BEFORE)
-
-
-/*
- * Find the node with the nearest value either greater or less than
- * the value from a previous avl_find(). Returns the node or NULL if
- * there isn't a matching one.
- *
- * where - position as returned from avl_find()
- * direction - either AVL_BEFORE or AVL_AFTER
- *
- * EXAMPLE get the greatest node that is less than a given value:
- *
- * avl_tree_t *tree;
- * struct my_data look_for_value = {....};
- * struct my_data *node;
- * struct my_data *less;
- * avl_index_t where;
- *
- * node = avl_find(tree, &look_for_value, &where);
- * if (node != NULL)
- * less = AVL_PREV(tree, node);
- * else
- * less = avl_nearest(tree, where, AVL_BEFORE);
- */
-extern void *avl_nearest(avl_tree_t *tree, avl_index_t where, int direction);
-
-
-/*
- * Add a single node to the tree.
- * The node must not be in the tree, and it must not
- * compare equal to any other node already in the tree.
- *
- * node - the node to add
- */
-extern void avl_add(avl_tree_t *tree, void *node);
-
-
-/*
- * Remove a single node from the tree. The node must be in the tree.
- *
- * node - the node to remove
- */
-extern void avl_remove(avl_tree_t *tree, void *node);
-
-/*
- * Reinsert a node only if its order has changed relative to its nearest
- * neighbors. To optimize performance avl_update_lt() checks only the previous
- * node and avl_update_gt() checks only the next node. Use avl_update_lt() and
- * avl_update_gt() only if you know the direction in which the order of the
- * node may change.
- */
-extern boolean_t avl_update(avl_tree_t *, void *);
-extern boolean_t avl_update_lt(avl_tree_t *, void *);
-extern boolean_t avl_update_gt(avl_tree_t *, void *);
-
-/*
- * Return the number of nodes in the tree
- */
-extern ulong_t avl_numnodes(avl_tree_t *tree);
-
-/*
- * Return B_TRUE if there are zero nodes in the tree, B_FALSE otherwise.
- */
-extern boolean_t avl_is_empty(avl_tree_t *tree);
-
-/*
- * Used to destroy any remaining nodes in a tree. The cookie argument should
- * be initialized to NULL before the first call. Returns a node that has been
- * removed from the tree and may be free()'d. Returns NULL when the tree is
- * empty.
- *
- * Once you call avl_destroy_nodes(), you can only continuing calling it and
- * finally avl_destroy(). No other AVL routines will be valid.
- *
- * cookie - a "void *" used to save state between calls to avl_destroy_nodes()
- *
- * EXAMPLE:
- * avl_tree_t *tree;
- * struct my_data *node;
- * void *cookie;
- *
- * cookie = NULL;
- * while ((node = avl_destroy_nodes(tree, &cookie)) != NULL)
- * free(node);
- * avl_destroy(tree);
- */
-extern void *avl_destroy_nodes(avl_tree_t *tree, void **cookie);
-
-
-/*
- * Final destroy of an AVL tree. Arguments are:
- *
- * tree - the empty tree to destroy
- */
-extern void avl_destroy(avl_tree_t *tree);
-
-
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* _AVL_H */
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