2 * Copyright (c) 2005 Michael Bushkov <bushman@rsu.ru>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
29 #ifndef __CACHELIB_HASHTABLE_H__
30 #define __CACHELIB_HASHTABLE_H__
34 #define HASHTABLE_INITIAL_ENTRIES_CAPACITY 8
35 typedef unsigned int hashtable_index_t;
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.
49 * Defines the hash table entry structure, that uses specified type of
52 #define HASHTABLE_ENTRY_HEAD(name, type) struct name { \
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.
63 #define HASHTABLE_HEAD(name, entry) struct name { \
64 struct entry *entries; \
65 size_t entries_size; \
68 #define HASHTABLE_ENTRIES_COUNT(table) \
69 ((table)->entries_size)
72 * Unlike most of queue.h data types, hash tables can not be initialized
73 * statically - so there is no HASHTABLE_HEAD_INITIALIZED macro.
75 #define HASHTABLE_INIT(table, type, field, _entries_size) \
77 hashtable_index_t var; \
78 (table)->entries = calloc(_entries_size, \
79 sizeof(*(table)->entries)); \
80 (table)->entries_size = (_entries_size); \
81 for (var = 0; var < HASHTABLE_ENTRIES_COUNT(table); ++var) {\
82 (table)->entries[var].field.capacity = \
83 HASHTABLE_INITIAL_ENTRIES_CAPACITY; \
84 (table)->entries[var].field.size = 0; \
85 (table)->entries[var].field.values = malloc( \
87 HASHTABLE_INITIAL_ENTRIES_CAPACITY); \
88 assert((table)->entries[var].field.values != NULL);\
93 * All initialized hashtables should be destroyed with this macro.
95 #define HASHTABLE_DESTROY(table, field) \
97 hashtable_index_t var; \
98 for (var = 0; var < HASHTABLE_ENTRIES_COUNT(table); ++var) {\
99 free((table)->entries[var].field.values); \
103 #define HASHTABLE_GET_ENTRY(table, hash) \
104 (&((table)->entries[hash]))
107 * Traverses through all hash table entries
109 #define HASHTABLE_FOREACH(table, var) \
110 for ((var) = &((table)->entries[0]); \
111 (var) < &((table)->entries[HASHTABLE_ENTRIES_COUNT(table)]);\
115 * Traverses through all elements of the specified hash table entry
117 #define HASHTABLE_ENTRY_FOREACH(entry, field, var) \
118 for ((var) = &((entry)->field.values[0]); \
119 (var) < &((entry)->field.values[(entry)->field.size]); \
122 #define HASHTABLE_ENTRY_CLEAR(entry, field) \
123 ((entry)->field.size = 0)
125 #define HASHTABLE_ENTRY_SIZE(entry, field) \
126 ((entry)->field.size)
128 #define HASHTABLE_ENTRY_CAPACITY(entry, field) \
129 ((entry)->field.capacity)
131 #define HASHTABLE_ENTRY_CAPACITY_INCREASE(entry, field, type) \
133 (entry)->field.capacity *= 2; \
134 (entry)->field.values = realloc((entry)->field.values, \
135 (entry)->field.capacity * sizeof(type)); \
138 #define HASHTABLE_ENTRY_CAPACITY_DECREASE(entry, field, type) \
140 (entry)->field.capacity /= 2; \
141 (entry)->field.values = realloc((entry)->field.values, \
142 (entry)->field.capacity * sizeof(type)); \
146 * Generates prototypes for the hash table functions
148 #define HASHTABLE_PROTOTYPE(name, entry_, type) \
149 hashtable_index_t name##_CALCULATE_HASH(struct name *, type *); \
150 void name##_ENTRY_STORE(struct entry_*, type *); \
151 type *name##_ENTRY_FIND(struct entry_*, type *); \
152 type *name##_ENTRY_FIND_SPECIAL(struct entry_ *, type *, \
153 int (*) (const void *, const void *)); \
154 void name##_ENTRY_REMOVE(struct entry_*, type *);
157 * Generates implementations of the hash table functions
159 #define HASHTABLE_GENERATE(name, entry_, type, field, HASH, CMP) \
160 hashtable_index_t name##_CALCULATE_HASH(struct name *table, type *data) \
163 return HASH(data, table->entries_size); \
166 void name##_ENTRY_STORE(struct entry_ *the_entry, type *data) \
169 if (the_entry->field.size == the_entry->field.capacity) \
170 HASHTABLE_ENTRY_CAPACITY_INCREASE(the_entry, field, type);\
172 memcpy(&(the_entry->field.values[the_entry->field.size++]), \
175 qsort(the_entry->field.values, the_entry->field.size, \
176 sizeof(type), CMP); \
179 type *name##_ENTRY_FIND(struct entry_ *the_entry, type *key) \
182 return ((type *)bsearch(key, the_entry->field.values, \
183 the_entry->field.size, sizeof(type), CMP)); \
186 type *name##_ENTRY_FIND_SPECIAL(struct entry_ *the_entry, type *key, \
187 int (*compar) (const void *, const void *)) \
189 return ((type *)bsearch(key, the_entry->field.values, \
190 the_entry->field.size, sizeof(type), compar)); \
193 void name##_ENTRY_REMOVE(struct entry_ *the_entry, type *del_elm) \
196 memmove(del_elm, del_elm + 1, \
197 (&the_entry->field.values[--the_entry->field.size] - del_elm) *\
202 * Macro definitions below wrap the functions, generaed with
203 * HASHTABLE_GENERATE macro. You should use them and avoid using generated
204 * functions directly.
206 #define HASHTABLE_CALCULATE_HASH(name, table, data) \
207 (name##_CALCULATE_HASH((table), data))
209 #define HASHTABLE_ENTRY_STORE(name, entry, data) \
210 name##_ENTRY_STORE((entry), data)
212 #define HASHTABLE_ENTRY_FIND(name, entry, key) \
213 (name##_ENTRY_FIND((entry), (key)))
215 #define HASHTABLE_ENTRY_FIND_SPECIAL(name, entry, key, cmp) \
216 (name##_ENTRY_FIND_SPECIAL((entry), (key), (cmp)))
218 #define HASHTABLE_ENTRY_REMOVE(name, entry, del_elm) \
219 name##_ENTRY_REMOVE((entry), (del_elm))