hashtable.h revision 158115
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 158115 2006-04-28 12:03:38Z ume $ 27 */ 28 29#ifndef __CACHELIB_HASHTABLE_H__ 30#define __CACHELIB_HASHTABLE_H__ 31 32#include <search.h> 33#include <string.h> 34 35#define HASHTABLE_INITIAL_ENTRIES_CAPACITY 8 36typedef int hashtable_index_t; 37 38/* 39 * This file contains queue.h-like macro definitions for hash tables. 40 * Hash table is organized as an array of the specified size of the user 41 * defined (with HASTABLE_ENTRY_HEAD) structures. Each hash table 42 * entry (user defined structure) stores its elements in the sorted array. 43 * You can place elements into the hash table, retrieve elements with 44 * specified key, traverse through all elements, and delete them. 45 * New elements are placed into the hash table by using the compare and 46 * hashing functions, provided by the user. 47 */ 48 49/* 50 * Defines the hash table entry structure, that uses specified type of 51 * elements. 52 */ 53#define HASHTABLE_ENTRY_HEAD(name, type) struct name { \ 54 type *values; \ 55 size_t capacity; \ 56 size_t size; \ 57} 58 59/* 60 * Defines the hash table structure, which uses the specified type of entries. 61 * The only restriction for entries is that is that they should have the field, 62 * defined with HASHTABLE_ENTRY_HEAD macro. 63 */ 64#define HASHTABLE_HEAD(name, entry) struct name { \ 65 struct entry *entries; \ 66 size_t entries_size; \ 67} 68 69#define HASHTABLE_ENTRIES_COUNT(table) ((table)->entries_size) 70 71/* 72 * Unlike most of queue.h data types, hash tables can not be initialized 73 * statically - so there is no HASHTABLE_HEAD_INITIALIZED macro. 74 */ 75#define HASHTABLE_INIT(table, type, field, _entries_size) \ 76 do { \ 77 hashtable_index_t var; \ 78 (table)->entries = (void *)malloc( \ 79 sizeof(*(table)->entries) * (_entries_size)); \ 80 memset((table)->entries, 0, \ 81 sizeof(*(table)->entries) * (_entries_size)); \ 82 (table)->entries_size = (_entries_size); \ 83 for (var = 0; var < HASHTABLE_ENTRIES_COUNT(table); ++var) {\ 84 (table)->entries[var].field.capacity = \ 85 HASHTABLE_INITIAL_ENTRIES_CAPACITY; \ 86 (table)->entries[var].field.size = 0; \ 87 (table)->entries[var].field.values = (type *)malloc(\ 88 sizeof(type) * \ 89 HASHTABLE_INITIAL_ENTRIES_CAPACITY); \ 90 assert((table)->entries[var].field.values != NULL);\ 91 } \ 92 } while (0) 93 94/* 95 * All initialized hashtables should be destroyed with this macro. 96 */ 97#define HASHTABLE_DESTROY(table, field) \ 98 do { \ 99 hashtable_index_t var; \ 100 for (var = 0; var < HASHTABLE_ENTRIES_COUNT(table); ++var) {\ 101 free((table)->entries[var].field.values); \ 102 } \ 103 } while (0) 104 105#define HASHTABLE_GET_ENTRY(table, hash) (&((table)->entries[hash])) 106 107/* 108 * Traverses through all hash table entries 109 */ 110#define HASHTABLE_FOREACH(table, var) \ 111 for ((var) = &((table)->entries[0]); \ 112 (var) < &((table)->entries[HASHTABLE_ENTRIES_COUNT(table)]);\ 113 ++(var)) 114 115/* 116 * Traverses through all elements of the specified hash table entry 117 */ 118#define HASHTABLE_ENTRY_FOREACH(entry, field, var) \ 119 for ((var) = &((entry)->field.values[0]); \ 120 (var) < &((entry)->field.values[(entry)->field.size]); \ 121 ++(var)) 122 123#define HASHTABLE_ENTRY_CLEAR(entry, field) \ 124 ((entry)->field.size = 0) 125 126#define HASHTABLE_ENTRY_SIZE(entry, field) \ 127 ((entry)->field.size) 128 129#define HASHTABLE_ENTRY_CAPACITY(entry, field) \ 130 ((entry)->field.capacity) 131 132#define HASHTABLE_ENTRY_CAPACITY_INCREASE(entry, field, type) \ 133 (entry)->field.capacity *= 2; \ 134 (entry)->field.values = (type *)realloc((entry)->field.values, \ 135 (entry)->field.capacity * sizeof(type)); 136 137#define HASHTABLE_ENTRY_CAPACITY_DECREASE(entry, field, type) \ 138 (entry)->field.capacity /= 2; \ 139 (entry)->field.values = (type *)realloc((entry)->field.values, \ 140 (entry)->field.capacity * sizeof(type)); 141 142/* 143 * Generates prototypes for the hash table functions 144 */ 145#define HASHTABLE_PROTOTYPE(name, entry_, type) \ 146hashtable_index_t name##_CALCULATE_HASH(struct name *, type *); \ 147void name##_ENTRY_STORE(struct entry_*, type *); \ 148type *name##_ENTRY_FIND(struct entry_*, type *); \ 149type *name##_ENTRY_FIND_SPECIAL(struct entry_ *, type *, \ 150 int (*) (const void *, const void *)); \ 151void name##_ENTRY_REMOVE(struct entry_*, type *); 152 153/* 154 * Generates implementations of the hash table functions 155 */ 156#define HASHTABLE_GENERATE(name, entry_, type, field, HASH, CMP) \ 157hashtable_index_t name##_CALCULATE_HASH(struct name *table, type *data) \ 158{ \ 159 \ 160 return HASH(data, table->entries_size); \ 161} \ 162 \ 163void name##_ENTRY_STORE(struct entry_ *the_entry, type *data) \ 164{ \ 165 \ 166 if (the_entry->field.size == the_entry->field.capacity) \ 167 HASHTABLE_ENTRY_CAPACITY_INCREASE(the_entry, field, type);\ 168 \ 169 memcpy(&(the_entry->field.values[the_entry->field.size++]), \ 170 data, \ 171 sizeof(type)); \ 172 qsort(the_entry->field.values, the_entry->field.size, \ 173 sizeof(type), CMP); \ 174} \ 175 \ 176type *name##_ENTRY_FIND(struct entry_ *the_entry, type *key) \ 177{ \ 178 \ 179 return ((type *)bsearch(key, the_entry->field.values, \ 180 the_entry->field.size, sizeof(type), CMP)); \ 181} \ 182 \ 183type *name##_ENTRY_FIND_SPECIAL(struct entry_ *the_entry, type *key, \ 184 int (*compar) (const void *, const void *)) \ 185{ \ 186 return ((type *)bsearch(key, the_entry->field.values, \ 187 the_entry->field.size, sizeof(type), compar)); \ 188} \ 189 \ 190void name##_ENTRY_REMOVE(struct entry_ *the_entry, type *del_elm) \ 191{ \ 192 \ 193 memmove(del_elm, del_elm + 1, \ 194 (&the_entry->field.values[--the_entry->field.size] - del_elm) *\ 195 sizeof(type)); \ 196} 197 198/* 199 * Macro definitions below wrap the functions, generaed with 200 * HASHTABLE_GENERATE macro. You should use them and avoid using generated 201 * functions directly. 202 */ 203#define HASHTABLE_CALCULATE_HASH(name, table, data) \ 204 (name##_CALCULATE_HASH((table), data)) 205 206#define HASHTABLE_ENTRY_STORE(name, entry, data) \ 207 name##_ENTRY_STORE((entry), data) 208 209#define HASHTABLE_ENTRY_FIND(name, entry, key) \ 210 (name##_ENTRY_FIND((entry), (key))) 211 212#define HASHTABLE_ENTRY_FIND_SPECIAL(name, entry, key, cmp) \ 213 (name##_ENTRY_FIND_SPECIAL((entry), (key), (cmp))) 214 215#define HASHTABLE_ENTRY_REMOVE(name, entry, del_elm) \ 216 name##_ENTRY_REMOVE((entry), (del_elm)) 217 218#endif 219