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/*
* radix.h -- generic radix tree
*
* Copyright (c) 2012, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
/**
* \file
* Radix tree. Implementation taken from NSD 4, adjusted for use in ldns.
*
*/
#ifndef LDNS_RADIX_H_
#define LDNS_RADIX_H_
#include <ldns/error.h>
#ifdef __cplusplus
extern "C" {
#endif
typedef uint16_t radix_strlen_t;
typedef struct ldns_radix_array_t ldns_radix_array_t;
typedef struct ldns_radix_node_t ldns_radix_node_t;
typedef struct ldns_radix_t ldns_radix_t;
/** Radix node select edge array */
struct ldns_radix_array_t {
/** Additional string after the selection byte for this edge. */
uint8_t* str;
/** Length of additional string for this edge. */
radix_strlen_t len;
/** Node that deals with byte+str. */
ldns_radix_node_t* edge;
};
/** A node in a radix tree */
struct ldns_radix_node_t {
/** Key corresponding to this node. */
uint8_t* key;
/** Key length corresponding to this node. */
radix_strlen_t klen;
/** Data corresponding to this node. */
void* data;
/** Parent node. */
ldns_radix_node_t* parent;
/** Index in the parent node select edge array. */
uint8_t parent_index;
/** Length of the array. */
uint16_t len;
/** Offset of the array. */
uint16_t offset;
/** Capacity of the array. */
uint16_t capacity;
/** Select edge array. */
ldns_radix_array_t* array;
};
/** An entire radix tree */
struct ldns_radix_t {
/** Root. */
ldns_radix_node_t* root;
/** Number of nodes in tree. */
size_t count;
};
/**
* Create a new radix tree.
* @return: new radix tree.
*
*/
ldns_radix_t* ldns_radix_create(void);
/**
* Initialize radix tree.
* @param tree: uninitialized radix tree.
*
*/
void ldns_radix_init(ldns_radix_t* tree);
/**
* Free the radix tree.
* @param tree: radix tree.
*
*/
void ldns_radix_free(ldns_radix_t* tree);
/**
* Insert data into the tree.
* @param tree: tree to insert to.
* @param key: key.
* @param len: length of key.
* @param data: data.
* @return: status.
*
*/
ldns_status ldns_radix_insert(ldns_radix_t* tree, uint8_t* key,
radix_strlen_t len, void* data);
/**
* Delete data from the tree.
* @param tree: tree to insert to.
* @param key: key.
* @param len: length of key.
* @return: unlinked data or NULL if not present.
*
*/
void* ldns_radix_delete(ldns_radix_t* tree, const uint8_t* key, radix_strlen_t len);
/**
* Search data in the tree.
* @param tree: tree to insert to.
* @param key: key.
* @param len: length of key.
* @return: the radix node or NULL if not found.
*
*/
ldns_radix_node_t* ldns_radix_search(ldns_radix_t* tree, const uint8_t* key,
radix_strlen_t len);
/**
* Search data in the tree, and if not found, find the closest smaller
* element in the tree.
* @param tree: tree to insert to.
* @param key: key.
* @param len: length of key.
* @param[out] result: the radix node with the exact or closest match. NULL if
* the key is smaller than the smallest key in the tree.
* @return 1 if exact match, 0 otherwise.
*
*/
int ldns_radix_find_less_equal(ldns_radix_t* tree, const uint8_t* key,
radix_strlen_t len, ldns_radix_node_t** result);
/**
* Get the first element in the tree.
* @param tree: tree.
* @return: the radix node with the first element.
*
*/
ldns_radix_node_t* ldns_radix_first(const ldns_radix_t* tree);
/**
* Get the last element in the tree.
* @param tree: tree.
* @return: the radix node with the last element.
*
*/
ldns_radix_node_t* ldns_radix_last(const ldns_radix_t* tree);
/**
* Next element.
* @param node: node.
* @return: node with next element.
*
*/
ldns_radix_node_t* ldns_radix_next(ldns_radix_node_t* node);
/**
* Previous element.
* @param node: node.
* @return: node with previous element.
*
*/
ldns_radix_node_t* ldns_radix_prev(ldns_radix_node_t* node);
/**
* Split radix tree intwo.
* @param tree1: one tree.
* @param num: number of elements to split off.
* @param[out] tree2: another tree.
* @return: status.
*
*/
ldns_status ldns_radix_split(ldns_radix_t* tree1, size_t num,
ldns_radix_t** tree2);
/**
* Join two radix trees.
* @param tree1: one tree.
* @param tree2: another tree.
* @return: status.
*
*/
ldns_status ldns_radix_join(ldns_radix_t* tree1, ldns_radix_t* tree2);
/**
* Call function for all nodes in the tree, such that leaf nodes are
* called before parent nodes.
* @param node: start node.
* @param func: function.
* @param arg: user argument.
*
*/
void ldns_radix_traverse_postorder(ldns_radix_node_t* node,
void (*func)(ldns_radix_node_t*, void*), void* arg);
/**
* Print radix tree (for debugging purposes).
* @param fd: file descriptor.
* @param tree: tree.
*
*/
void ldns_radix_printf(FILE* fd, const ldns_radix_t* tree);
#ifdef __cplusplus
}
#endif
#endif /* LDNS_RADIX_H_ */
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