/* * Copyright © 2008 Intel Corporation * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the next * paragraph) shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. */ /** * \file hash_table.c * \brief Implementation of a generic, opaque hash table data type. * * \author Ian Romanick <ian.d.romanick@intel.com> */ #include <stdlib.h> #include <string.h> #include <assert.h> #include "main/imports.h" #include "main/simple_list.h" #include "hash_table.h" struct node { struct node *next; struct node *prev; }; struct hash_table { hash_func_t hash; hash_compare_func_t compare; unsigned num_buckets; struct node buckets[1]; }; struct hash_node { struct node link; const void *key; void *data; }; struct hash_table * hash_table_ctor(unsigned num_buckets, hash_func_t hash, hash_compare_func_t compare) { struct hash_table *ht; unsigned i; if (num_buckets < 16) { num_buckets = 16; } ht = _mesa_malloc(sizeof(*ht) + ((num_buckets - 1) * sizeof(ht->buckets[0]))); if (ht != NULL) { ht->hash = hash; ht->compare = compare; ht->num_buckets = num_buckets; for (i = 0; i < num_buckets; i++) { make_empty_list(& ht->buckets[i]); } } return ht; } void hash_table_dtor(struct hash_table *ht) { hash_table_clear(ht); _mesa_free(ht); } void hash_table_clear(struct hash_table *ht) { struct node *node; struct node *temp; unsigned i; for (i = 0; i < ht->num_buckets; i++) { foreach_s(node, temp, & ht->buckets[i]) { remove_from_list(node); _mesa_free(node); } assert(is_empty_list(& ht->buckets[i])); } } void * hash_table_find(struct hash_table *ht, const void *key) { const unsigned hash_value = (*ht->hash)(key); const unsigned bucket = hash_value % ht->num_buckets; struct node *node; foreach(node, & ht->buckets[bucket]) { struct hash_node *hn = (struct hash_node *) node; if ((*ht->compare)(hn->key, key) == 0) { return hn->data; } } return NULL; } void hash_table_insert(struct hash_table *ht, void *data, const void *key) { const unsigned hash_value = (*ht->hash)(key); const unsigned bucket = hash_value % ht->num_buckets; struct hash_node *node; node = _mesa_calloc(sizeof(*node)); node->data = data; node->key = key; insert_at_head(& ht->buckets[bucket], & node->link); } unsigned hash_table_string_hash(const void *key) { const char *str = (const char *) key; unsigned hash = 5381; while (*str != '\0') { hash = (hash * 33) + *str; str++; } return hash; }