diff options
Diffstat (limited to 'ldns/radix.h')
| -rw-r--r-- | ldns/radix.h | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/ldns/radix.h b/ldns/radix.h new file mode 100644 index 0000000..ec70565 --- /dev/null +++ b/ldns/radix.h @@ -0,0 +1,240 @@ +/* + * 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 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 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 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_ */ |