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Diffstat (limited to 'pjlib/include/pj/rbtree.h')
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1 files changed, 210 insertions, 0 deletions
diff --git a/pjlib/include/pj/rbtree.h b/pjlib/include/pj/rbtree.h new file mode 100644 index 0000000..2f92285 --- /dev/null +++ b/pjlib/include/pj/rbtree.h @@ -0,0 +1,210 @@ +/* $Id: rbtree.h 3553 2011-05-05 06:14:19Z nanang $ */ +/* + * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com) + * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ +#ifndef __PJ_RBTREE_H__ +#define __PJ_RBTREE_H__ + +/** + * @file rbtree.h + * @brief Red/Black Tree + */ + +#include <pj/types.h> + +PJ_BEGIN_DECL + +/** + * @defgroup PJ_RBTREE Red/Black Balanced Tree + * @ingroup PJ_DS + * @brief + * Red/Black tree is the variant of balanced tree, where the search, insert, + * and delete operation is \b guaranteed to take at most \a O( lg(n) ). + * @{ + */ +/** + * Color type for Red-Black tree. + */ +typedef enum pj_rbcolor_t +{ + PJ_RBCOLOR_BLACK, + PJ_RBCOLOR_RED +} pj_rbcolor_t; + +/** + * The type of the node of the R/B Tree. + */ +typedef struct pj_rbtree_node +{ + /** Pointers to the node's parent, and left and right siblings. */ + struct pj_rbtree_node *parent, *left, *right; + + /** Key associated with the node. */ + const void *key; + + /** User data associated with the node. */ + void *user_data; + + /** The R/B Tree node color. */ + pj_rbcolor_t color; + +} pj_rbtree_node; + + +/** + * The type of function use to compare key value of tree node. + * @return + * 0 if the keys are equal + * <0 if key1 is lower than key2 + * >0 if key1 is greater than key2. + */ +typedef int pj_rbtree_comp(const void *key1, const void *key2); + + +/** + * Declaration of a red-black tree. All elements in the tree must have UNIQUE + * key. + * A red black tree always maintains the balance of the tree, so that the + * tree height will not be greater than lg(N). Insert, search, and delete + * operation will take lg(N) on the worst case. But for insert and delete, + * there is additional time needed to maintain the balance of the tree. + */ +typedef struct pj_rbtree +{ + pj_rbtree_node null_node; /**< Constant to indicate NULL node. */ + pj_rbtree_node *null; /**< Constant to indicate NULL node. */ + pj_rbtree_node *root; /**< Root tree node. */ + unsigned size; /**< Number of elements in the tree. */ + pj_rbtree_comp *comp; /**< Key comparison function. */ +} pj_rbtree; + + +/** + * Guidance on how much memory required for each of the node. + */ +#define PJ_RBTREE_NODE_SIZE (sizeof(pj_rbtree_node)) + + +/** + * Guidance on memory required for the tree. + */ +#define PJ_RBTREE_SIZE (sizeof(pj_rbtree)) + + +/** + * Initialize the tree. + * @param tree the tree to be initialized. + * @param comp key comparison function to be used for this tree. + */ +PJ_DECL(void) pj_rbtree_init( pj_rbtree *tree, pj_rbtree_comp *comp); + +/** + * Get the first element in the tree. + * The first element always has the least value for the key, according to + * the comparison function. + * @param tree the tree. + * @return the tree node, or NULL if the tree has no element. + */ +PJ_DECL(pj_rbtree_node*) pj_rbtree_first( pj_rbtree *tree ); + +/** + * Get the last element in the tree. + * The last element always has the greatest key value, according to the + * comparison function defined for the tree. + * @param tree the tree. + * @return the tree node, or NULL if the tree has no element. + */ +PJ_DECL(pj_rbtree_node*) pj_rbtree_last( pj_rbtree *tree ); + +/** + * Get the successive element for the specified node. + * The successive element is an element with greater key value. + * @param tree the tree. + * @param node the node. + * @return the successive node, or NULL if the node has no successor. + */ +PJ_DECL(pj_rbtree_node*) pj_rbtree_next( pj_rbtree *tree, + pj_rbtree_node *node ); + +/** + * The the previous node for the specified node. + * The previous node is an element with less key value. + * @param tree the tree. + * @param node the node. + * @return the previous node, or NULL if the node has no previous node. + */ +PJ_DECL(pj_rbtree_node*) pj_rbtree_prev( pj_rbtree *tree, + pj_rbtree_node *node ); + +/** + * Insert a new node. + * The node will be inserted at sorted location. The key of the node must + * be UNIQUE, i.e. it hasn't existed in the tree. + * @param tree the tree. + * @param node the node to be inserted. + * @return zero on success, or -1 if the key already exist. + */ +PJ_DECL(int) pj_rbtree_insert( pj_rbtree *tree, + pj_rbtree_node *node ); + +/** + * Find a node which has the specified key. + * @param tree the tree. + * @param key the key to search. + * @return the tree node with the specified key, or NULL if the key can not + * be found. + */ +PJ_DECL(pj_rbtree_node*) pj_rbtree_find( pj_rbtree *tree, + const void *key ); + +/** + * Erase a node from the tree. + * @param tree the tree. + * @param node the node to be erased. + * @return the tree node itself. + */ +PJ_DECL(pj_rbtree_node*) pj_rbtree_erase( pj_rbtree *tree, + pj_rbtree_node *node ); + +/** + * Get the maximum tree height from the specified node. + * @param tree the tree. + * @param node the node, or NULL to get the root of the tree. + * @return the maximum height, which should be at most lg(N) + */ +PJ_DECL(unsigned) pj_rbtree_max_height( pj_rbtree *tree, + pj_rbtree_node *node ); + +/** + * Get the minumum tree height from the specified node. + * @param tree the tree. + * @param node the node, or NULL to get the root of the tree. + * @return the height + */ +PJ_DECL(unsigned) pj_rbtree_min_height( pj_rbtree *tree, + pj_rbtree_node *node ); + + +/** + * @} + */ + +PJ_END_DECL + +#endif /* __PJ_RBTREE_H__ */ + |