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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:54:46 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:54:46 +0000 |
commit | cd7b005519ade8ab6c97fcb21590b71b7d1be6e3 (patch) | |
tree | c611a8d0cd5e8f68f41b8c2d16ba580e0f40a38d /third-party/tommyds/tommytrie.h | |
parent | Initial commit. (diff) | |
download | librtr-cd7b005519ade8ab6c97fcb21590b71b7d1be6e3.tar.xz librtr-cd7b005519ade8ab6c97fcb21590b71b7d1be6e3.zip |
Adding upstream version 0.8.0.upstream/0.8.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third-party/tommyds/tommytrie.h')
-rw-r--r-- | third-party/tommyds/tommytrie.h | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/third-party/tommyds/tommytrie.h b/third-party/tommyds/tommytrie.h new file mode 100644 index 0000000..d82a5f2 --- /dev/null +++ b/third-party/tommyds/tommytrie.h @@ -0,0 +1,260 @@ +/* + * Copyright (c) 2010, Andrea Mazzoleni. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. 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. + * + * 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 OWNER 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 + * Trie optimized for cache utilization. + * + * This trie is a standard implementation that stores elements in the order defined + * by the key. + * + * It needs an external allocator for the inner nodes in the trie. + * + * You can control the number of branches of each node using the ::TOMMY_TRIE_TREE_MAX + * define. More branches imply more speed, but a bigger memory occupation. + * + * Compared to ::tommy_trie_inplace you have to provide a ::tommy_allocator allocator. + * Note that the C malloc() is too slow to futfill this role. + * + * To initialize the trie you have to call tommy_allocator_init() to initialize + * the allocator, and tommy_trie_init() for the trie. + * + * \code + * tommy_allocator alloc; + * tommy_trie trie; + * + * tommy_allocator_init(&alloc, TOMMY_TRIE_BLOCK_SIZE, TOMMY_TRIE_BLOCK_SIZE); + * + * tommy_trie_init(&trie, &alloc); + * \endcode + * + * To insert elements in the trie you have to call tommy_trie_insert() for + * each element. + * In the insertion call you have to specify the address of the node, the + * address of the object, and the key value to use. + * The address of the object is used to initialize the tommy_node::data field + * of the node, and the key to initialize the tommy_node::key field. + * + * \code + * struct object { + * int value; + * // other fields + * tommy_node node; + * }; + * + * struct object* obj = malloc(sizeof(struct object)); // creates the object + * + * obj->value = ...; // initializes the object + * + * tommy_trie_insert(&trie, &obj->node, obj, obj->value); // inserts the object + * \endcode + * + * To find and element in the trie you have to call tommy_trie_search() providing + * the key to search. + * + * \code + * int value_to_find = 1; + * struct object* obj = tommy_trie_search(&trie, value_to_find); + * if (!obj) { + * // not found + * } else { + * // found + * } + * \endcode + * + * To iterate over all the elements in the trie with the same key, you have to + * use tommy_trie_bucket() and follow the tommy_node::next pointer until NULL. + * + * \code + * int value_to_find = 1; + * tommy_node* i = tommy_trie_bucket(&trie, value_to_find); + * while (i) { + * struct object* obj = i->data; // gets the object pointer + * + * printf("%d\n", obj->value); // process the object + * + * i = i->next; // goes to the next element + * } + * \endcode + * + * To remove an element from the trie you have to call tommy_trie_remove() + * providing the key to search and remove. + * + * \code + * struct object* obj = tommy_trie_remove(&trie, value_to_remove); + * if (obj) { + * free(obj); // frees the object allocated memory + * } + * \endcode + * + * To destroy the trie you have to remove all the elements, and deinitialize + * the allocator using tommy_allocator_done(). + * + * \code + * tommy_allocator_done(&alloc); + * \endcode + * + * Note that you cannot iterate over all the elements in the trie using the + * trie itself. You have to insert all the elements also in a ::tommy_list, + * and use the list to iterate. See the \ref multiindex example for more detail. + */ + +#ifndef __TOMMYTRIE_H +#define __TOMMYTRIE_H + +#include "tommytypes.h" +#include "tommyalloc.h" + +/******************************************************************************/ +/* trie */ + +/** + * Number of branches on each inner node. It must be a power of 2. + * Suggested values are 8, 16 and 32. + * Any inner node, excluding leafs, contains a pointer to each branch. + * + * The default size is choosen to exactly fit a typical cache line of 64 bytes. + */ +#define TOMMY_TRIE_TREE_MAX (64 / sizeof(void*)) + +/** + * Trie block size. + * You must use this value to initialize the allocator. + */ +#define TOMMY_TRIE_BLOCK_SIZE (TOMMY_TRIE_TREE_MAX * sizeof(void*)) + +/** \internal + * Number of bits for each branch. + */ +#define TOMMY_TRIE_TREE_BIT TOMMY_ILOG2(TOMMY_TRIE_TREE_MAX) + +/** \internal + * Number of bits of the first level. + */ +#define TOMMY_TRIE_BUCKET_BIT ((TOMMY_KEY_BIT % TOMMY_TRIE_TREE_BIT) + TOMMY_TRIE_TREE_BIT) + +/** \internal + * Number of branches of the first level. + * It's like a inner branch, but bigger to get any remainder bits. + */ +#define TOMMY_TRIE_BUCKET_MAX (1 << TOMMY_TRIE_BUCKET_BIT) + +/** + * Trie node. + * This is the node that you have to include inside your objects. + */ +typedef tommy_node tommy_trie_node; + +/** + * Trie container type. + * \note Don't use internal fields directly, but access the container only using functions. + */ +typedef struct tommy_trie_struct { + tommy_trie_node* bucket[TOMMY_TRIE_BUCKET_MAX]; /**< First tree level. */ + tommy_count_t count; /**< Number of elements. */ + tommy_count_t node_count; /**< Number of nodes. */ + tommy_allocator* alloc; /**< Allocator for internal nodes. */ +} tommy_trie; + +/** + * Initializes the trie. + * You have to provide an allocator initialized with *both* the size and align with TOMMY_TRIE_BLOCK_SIZE. + * You can share this allocator with other tries. + * + * The tries is completely allocated through the allocator, and it doesn't need to be deinitialized. + * \param alloc Allocator initialized with *both* the size and align with TOMMY_TRIE_BLOCK_SIZE. + */ +void tommy_trie_init(tommy_trie* trie, tommy_allocator* alloc); + +/** + * Inserts an element in the trie. + * You have to provide the pointer of the node embedded into the object, + * the pointer to the object and the key to use. + * \param node Pointer to the node embedded into the object to insert. + * \param data Pointer to the object to insert. + * \param key Key to use to insert the object. + */ +void tommy_trie_insert(tommy_trie* trie, tommy_trie_node* node, void* data, tommy_key_t key); + +/** + * Searches and removes the first element with the specified key. + * If the element is not found, 0 is returned. + * If more equal elements are present, the first one is removed. + * This operation is faster than calling tommy_trie_bucket() and tommy_trie_remove_existing() separately. + * \param key Key of the element to find and remove. + * \return The removed element, or 0 if not found. + */ +void* tommy_trie_remove(tommy_trie* trie, tommy_key_t key); + +/** + * Gets the bucket of the specified key. + * The bucket is guaranteed to contain ALL and ONLY the elements with the specified key. + * You can access elements in the bucket following the ::next pointer until 0. + * \param key Key of the element to find. + * \return The head of the bucket, or 0 if empty. + */ +tommy_trie_node* tommy_trie_bucket(tommy_trie* trie, tommy_key_t key); + +/** + * Searches an element in the trie. + * You have to provide the key of the element you want to find. + * If more elements with the same key are present, the first one is returned. + * \param key Key of the element to find. + * \return The first element found, or 0 if none. + */ +tommy_inline void* tommy_trie_search(tommy_trie* trie, tommy_key_t key) +{ + tommy_trie_node* i = tommy_trie_bucket(trie, key); + + if (!i) + return 0; + + return i->data; +} + +/** + * Removes an element from the trie. + * You must already have the address of the element to remove. + * \return The tommy_node::data field of the node removed. + */ +void* tommy_trie_remove_existing(tommy_trie* trie, tommy_trie_node* node); + +/** + * Gets the number of elements. + */ +tommy_inline tommy_count_t tommy_trie_count(tommy_trie* trie) +{ + return trie->count; +} + +/** + * Gets the size of allocated memory. + * It includes the size of the ::tommy_trie_node of the stored elements. + */ +tommy_size_t tommy_trie_memory_usage(tommy_trie* trie); + +#endif + |