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 27 #ifndef __CACHELIB_HASHTABLE_H__ 28 #define __CACHELIB_HASHTABLE_H__ 29 30 #include <string.h> 31 32 #define HASHTABLE_INITIAL_ENTRIES_CAPACITY 8 33 typedef unsigned int hashtable_index_t; 34 35 /* 36 * This file contains queue.h-like macro definitions for hash tables. 37 * Hash table is organized as an array of the specified size of the user 38 * defined (with HASTABLE_ENTRY_HEAD) structures. Each hash table 39 * entry (user defined structure) stores its elements in the sorted array. 40 * You can place elements into the hash table, retrieve elements with 41 * specified key, traverse through all elements, and delete them. 42 * New elements are placed into the hash table by using the compare and 43 * hashing functions, provided by the user. 44 */ 45 46 /* 47 * Defines the hash table entry structure, that uses specified type of 48 * elements. 49 */ 50 #define HASHTABLE_ENTRY_HEAD(name, type) struct name { \ 51 type *values; \ 52 size_t capacity; \ 53 size_t size; \ 54 } 55 56 /* 57 * Defines the hash table structure, which uses the specified type of entries. 58 * The only restriction for entries is that is that they should have the field, 59 * defined with HASHTABLE_ENTRY_HEAD macro. 60 */ 61 #define HASHTABLE_HEAD(name, entry) struct name { \ 62 struct entry *entries; \ 63 size_t entries_size; \ 64 } 65 66 #define HASHTABLE_ENTRIES_COUNT(table) \ 67 ((table)->entries_size) 68 69 /* 70 * Unlike most of queue.h data types, hash tables can not be initialized 71 * statically - so there is no HASHTABLE_HEAD_INITIALIZED macro. 72 */ 73 #define HASHTABLE_INIT(table, type, field, _entries_size) \ 74 do { \ 75 hashtable_index_t var; \ 76 (table)->entries = calloc(_entries_size, \ 77 sizeof(*(table)->entries)); \ 78 (table)->entries_size = (_entries_size); \ 79 for (var = 0; var < HASHTABLE_ENTRIES_COUNT(table); ++var) {\ 80 (table)->entries[var].field.capacity = \ 81 HASHTABLE_INITIAL_ENTRIES_CAPACITY; \ 82 (table)->entries[var].field.size = 0; \ 83 (table)->entries[var].field.values = malloc( \ 84 sizeof(type) * \ 85 HASHTABLE_INITIAL_ENTRIES_CAPACITY); \ 86 assert((table)->entries[var].field.values != NULL);\ 87 } \ 88 } while (0) 89 90 /* 91 * All initialized hashtables should be destroyed with this macro. 92 */ 93 #define HASHTABLE_DESTROY(table, field) \ 94 do { \ 95 hashtable_index_t var; \ 96 for (var = 0; var < HASHTABLE_ENTRIES_COUNT(table); ++var) {\ 97 free((table)->entries[var].field.values); \ 98 } \ 99 } while (0) 100 101 #define HASHTABLE_GET_ENTRY(table, hash) \ 102 (&((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 do { \ 131 (entry)->field.capacity *= 2; \ 132 (entry)->field.values = realloc((entry)->field.values, \ 133 (entry)->field.capacity * sizeof(type)); \ 134 } while (0) 135 136 #define HASHTABLE_ENTRY_CAPACITY_DECREASE(entry, field, type) \ 137 do { \ 138 (entry)->field.capacity /= 2; \ 139 (entry)->field.values = realloc((entry)->field.values, \ 140 (entry)->field.capacity * sizeof(type)); \ 141 } while (0) 142 143 /* 144 * Generates prototypes for the hash table functions 145 */ 146 #define HASHTABLE_PROTOTYPE(name, entry_, type) \ 147 hashtable_index_t name##_CALCULATE_HASH(struct name *, type *); \ 148 void name##_ENTRY_STORE(struct entry_*, type *); \ 149 type *name##_ENTRY_FIND(struct entry_*, type *); \ 150 type *name##_ENTRY_FIND_SPECIAL(struct entry_ *, type *, \ 151 int (*) (const void *, const void *)); \ 152 void name##_ENTRY_REMOVE(struct entry_*, type *); 153 154 /* 155 * Generates implementations of the hash table functions 156 */ 157 #define HASHTABLE_GENERATE(name, entry_, type, field, HASH, CMP) \ 158 hashtable_index_t name##_CALCULATE_HASH(struct name *table, type *data) \ 159 { \ 160 \ 161 return HASH(data, table->entries_size); \ 162 } \ 163 \ 164 void name##_ENTRY_STORE(struct entry_ *the_entry, type *data) \ 165 { \ 166 \ 167 if (the_entry->field.size == the_entry->field.capacity) \ 168 HASHTABLE_ENTRY_CAPACITY_INCREASE(the_entry, field, type);\ 169 \ 170 memcpy(&(the_entry->field.values[the_entry->field.size++]), \ 171 data, \ 172 sizeof(type)); \ 173 qsort(the_entry->field.values, the_entry->field.size, \ 174 sizeof(type), CMP); \ 175 } \ 176 \ 177 type *name##_ENTRY_FIND(struct entry_ *the_entry, type *key) \ 178 { \ 179 \ 180 return ((type *)bsearch(key, the_entry->field.values, \ 181 the_entry->field.size, sizeof(type), CMP)); \ 182 } \ 183 \ 184 type *name##_ENTRY_FIND_SPECIAL(struct entry_ *the_entry, type *key, \ 185 int (*compar) (const void *, const void *)) \ 186 { \ 187 return ((type *)bsearch(key, the_entry->field.values, \ 188 the_entry->field.size, sizeof(type), compar)); \ 189 } \ 190 \ 191 void name##_ENTRY_REMOVE(struct entry_ *the_entry, type *del_elm) \ 192 { \ 193 \ 194 memmove(del_elm, del_elm + 1, \ 195 (&the_entry->field.values[--the_entry->field.size] - del_elm) *\ 196 sizeof(type)); \ 197 } 198 199 /* 200 * Macro definitions below wrap the functions, generaed with 201 * HASHTABLE_GENERATE macro. You should use them and avoid using generated 202 * functions directly. 203 */ 204 #define HASHTABLE_CALCULATE_HASH(name, table, data) \ 205 (name##_CALCULATE_HASH((table), data)) 206 207 #define HASHTABLE_ENTRY_STORE(name, entry, data) \ 208 name##_ENTRY_STORE((entry), data) 209 210 #define HASHTABLE_ENTRY_FIND(name, entry, key) \ 211 (name##_ENTRY_FIND((entry), (key))) 212 213 #define HASHTABLE_ENTRY_FIND_SPECIAL(name, entry, key, cmp) \ 214 (name##_ENTRY_FIND_SPECIAL((entry), (key), (cmp))) 215 216 #define HASHTABLE_ENTRY_REMOVE(name, entry, del_elm) \ 217 name##_ENTRY_REMOVE((entry), (del_elm)) 218 219 #endif 220