X-Git-Url: https://git.camperquake.de/gitweb.cgi?a=blobdiff_plain;ds=inline;f=module%2Favl%2Finclude%2Fsys%2Favl.h;fp=module%2Favl%2Finclude%2Fsys%2Favl.h;h=0000000000000000000000000000000000000000;hb=6283f55ea1b91e680386388c17d14b89e344fa8d;hp=ba305c9082392ee7b970b2032704c8ea4a74df9c;hpb=5e6121455c0b941f4612ceb2c1f312d527534b46;p=zfs.git diff --git a/module/avl/include/sys/avl.h b/module/avl/include/sys/avl.h deleted file mode 100644 index ba305c9..0000000 --- a/module/avl/include/sys/avl.h +++ /dev/null @@ -1,309 +0,0 @@ -/* - * 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 -#include - -/* - * 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 */