hashtable.h revision 194089
1/*- 2 * Copyright (c) 2005 Michael Bushkov <bushman@rsu.ru> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD: head/usr.sbin/nscd/hashtable.h 194089 2009-06-13 00:06:52Z des $ 27 */ 28 29#ifndef __CACHELIB_HASHTABLE_H__ 30#define __CACHELIB_HASHTABLE_H__ 31 32#include <string.h> 33 34#define HASHTABLE_INITIAL_ENTRIES_CAPACITY 8 35typedef int hashtable_index_t; 36 37/* 38 * This file contains queue.h-like macro definitions for hash tables. 39 * Hash table is organized as an array of the specified size of the user 40 * defined (with HASTABLE_ENTRY_HEAD) structures. Each hash table 41 * entry (user defined structure) stores its elements in the sorted array. 42 * You can place elements into the hash table, retrieve elements with 43 * specified key, traverse through all elements, and delete them. 44 * New elements are placed into the hash table by using the compare and 45 * hashing functions, provided by the user. 46 */ 47 48/* 49 * Defines the hash table entry structure, that uses specified type of 50 * elements. 51 */ 52#define HASHTABLE_ENTRY_HEAD(name, type) struct name { \ 53 type *values; \ 54 size_t capacity; \ 55 size_t size; \ 56} 57 58/* 59 * Defines the hash table structure, which uses the specified type of entries. 60 * The only restriction for entries is that is that they should have the field, 61 * defined with HASHTABLE_ENTRY_HEAD macro. 62 */ 63#define HASHTABLE_HEAD(name, entry) struct name { \ 64 struct entry *entries; \ 65 size_t entries_size; \ 66} 67 68#define HASHTABLE_ENTRIES_COUNT(table) ((table)->entries_size) 69 70/* 71 * Unlike most of queue.h data types, hash tables can not be initialized 72 * statically - so there is no HASHTABLE_HEAD_INITIALIZED macro. 73 */ 74#define HASHTABLE_INIT(table, type, field, _entries_size) \ 75 do { \ 76 hashtable_index_t var; \ 77 (table)->entries = (void *)calloc(1, \ 78 sizeof(*(table)->entries) * (_entries_size)); \ 79 (table)->entries_size = (_entries_size); \ 80 for (var = 0; var < HASHTABLE_ENTRIES_COUNT(table); ++var) {\ 81 (table)->entries[var].field.capacity = \ 82 HASHTABLE_INITIAL_ENTRIES_CAPACITY; \ 83 (table)->entries[var].field.size = 0; \ 84 (table)->entries[var].field.values = (type *)malloc(\ 85 sizeof(type) * \ 86 HASHTABLE_INITIAL_ENTRIES_CAPACITY); \ 87 assert((table)->entries[var].field.values != NULL);\ 88 } \ 89 } while (0) 90 91/* 92 * All initialized hashtables should be destroyed with this macro. 93 */ 94#define HASHTABLE_DESTROY(table, field) \ 95 do { \ 96 hashtable_index_t var; \ 97 for (var = 0; var < HASHTABLE_ENTRIES_COUNT(table); ++var) {\ 98 free((table)->entries[var].field.values); \ 99 } \ 100 } while (0) 101 102#define HASHTABLE_GET_ENTRY(table, hash) (&((table)->entries[hash])) 103 104/* 105 * Traverses through all hash table entries 106 */ 107#define HASHTABLE_FOREACH(table, var) \ 108 for ((var) = &((table)->entries[0]); \ 109 (var) < &((table)->entries[HASHTABLE_ENTRIES_COUNT(table)]);\ 110 ++(var)) 111 112/* 113 * Traverses through all elements of the specified hash table entry 114 */ 115#define HASHTABLE_ENTRY_FOREACH(entry, field, var) \ 116 for ((var) = &((entry)->field.values[0]); \ 117 (var) < &((entry)->field.values[(entry)->field.size]); \ 118 ++(var)) 119 120#define HASHTABLE_ENTRY_CLEAR(entry, field) \ 121 ((entry)->field.size = 0) 122 123#define HASHTABLE_ENTRY_SIZE(entry, field) \ 124 ((entry)->field.size) 125 126#define HASHTABLE_ENTRY_CAPACITY(entry, field) \ 127 ((entry)->field.capacity) 128 129#define HASHTABLE_ENTRY_CAPACITY_INCREASE(entry, field, type) \ 130 (entry)->field.capacity *= 2; \ 131 (entry)->field.values = (type *)realloc((entry)->field.values, \ 132 (entry)->field.capacity * sizeof(type)); 133 134#define HASHTABLE_ENTRY_CAPACITY_DECREASE(entry, field, type) \ 135 (entry)->field.capacity /= 2; \ 136 (entry)->field.values = (type *)realloc((entry)->field.values, \ 137 (entry)->field.capacity * sizeof(type)); 138 139/* 140 * Generates prototypes for the hash table functions 141 */ 142#define HASHTABLE_PROTOTYPE(name, entry_, type) \ 143hashtable_index_t name##_CALCULATE_HASH(struct name *, type *); \ 144void name##_ENTRY_STORE(struct entry_*, type *); \ 145type *name##_ENTRY_FIND(struct entry_*, type *); \ 146type *name##_ENTRY_FIND_SPECIAL(struct entry_ *, type *, \ 147 int (*) (const void *, const void *)); \ 148void name##_ENTRY_REMOVE(struct entry_*, type *); 149 150/* 151 * Generates implementations of the hash table functions 152 */ 153#define HASHTABLE_GENERATE(name, entry_, type, field, HASH, CMP) \ 154hashtable_index_t name##_CALCULATE_HASH(struct name *table, type *data) \ 155{ \ 156 \ 157 return HASH(data, table->entries_size); \ 158} \ 159 \ 160void name##_ENTRY_STORE(struct entry_ *the_entry, type *data) \ 161{ \ 162 \ 163 if (the_entry->field.size == the_entry->field.capacity) \ 164 HASHTABLE_ENTRY_CAPACITY_INCREASE(the_entry, field, type);\ 165 \ 166 memcpy(&(the_entry->field.values[the_entry->field.size++]), \ 167 data, \ 168 sizeof(type)); \ 169 qsort(the_entry->field.values, the_entry->field.size, \ 170 sizeof(type), CMP); \ 171} \ 172 \ 173type *name##_ENTRY_FIND(struct entry_ *the_entry, type *key) \ 174{ \ 175 \ 176 return ((type *)bsearch(key, the_entry->field.values, \ 177 the_entry->field.size, sizeof(type), CMP)); \ 178} \ 179 \ 180type *name##_ENTRY_FIND_SPECIAL(struct entry_ *the_entry, type *key, \ 181 int (*compar) (const void *, const void *)) \ 182{ \ 183 return ((type *)bsearch(key, the_entry->field.values, \ 184 the_entry->field.size, sizeof(type), compar)); \ 185} \ 186 \ 187void name##_ENTRY_REMOVE(struct entry_ *the_entry, type *del_elm) \ 188{ \ 189 \ 190 memmove(del_elm, del_elm + 1, \ 191 (&the_entry->field.values[--the_entry->field.size] - del_elm) *\ 192 sizeof(type)); \ 193} 194 195/* 196 * Macro definitions below wrap the functions, generaed with 197 * HASHTABLE_GENERATE macro. You should use them and avoid using generated 198 * functions directly. 199 */ 200#define HASHTABLE_CALCULATE_HASH(name, table, data) \ 201 (name##_CALCULATE_HASH((table), data)) 202 203#define HASHTABLE_ENTRY_STORE(name, entry, data) \ 204 name##_ENTRY_STORE((entry), data) 205 206#define HASHTABLE_ENTRY_FIND(name, entry, key) \ 207 (name##_ENTRY_FIND((entry), (key))) 208 209#define HASHTABLE_ENTRY_FIND_SPECIAL(name, entry, key, cmp) \ 210 (name##_ENTRY_FIND_SPECIAL((entry), (key), (cmp))) 211 212#define HASHTABLE_ENTRY_REMOVE(name, entry, del_elm) \ 213 name##_ENTRY_REMOVE((entry), (del_elm)) 214 215#endif 216