1 /*
2 * Copyright © 2008 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 */
23
24 /**
25 * \file hash_table.c
26 * \brief Implementation of a generic, opaque hash table data type.
27 *
28 * \author Ian Romanick <ian.d.romanick@intel.com>
29 */
30
31 #include "main/imports.h"
32 #include "main/simple_list.h"
33 #include "hash_table.h"
34
35 struct node {
36 struct node *next;
37 struct node *prev;
38 };
39
40 struct hash_table {
41 hash_func_t hash;
42 hash_compare_func_t compare;
43
44 unsigned num_buckets;
45 struct node buckets[1];
46 };
47
48
49 struct hash_node {
50 struct node link;
51 const void *key;
52 void *data;
53 };
54
55
56 struct hash_table *
hash_table_ctor(unsigned num_buckets,hash_func_t hash,hash_compare_func_t compare)57 hash_table_ctor(unsigned num_buckets, hash_func_t hash,
58 hash_compare_func_t compare)
59 {
60 struct hash_table *ht;
61 unsigned i;
62
63
64 if (num_buckets < 16) {
65 num_buckets = 16;
66 }
67
68 ht = malloc(sizeof(*ht) + ((num_buckets - 1)
69 * sizeof(ht->buckets[0])));
70 if (ht != NULL) {
71 ht->hash = hash;
72 ht->compare = compare;
73 ht->num_buckets = num_buckets;
74
75 for (i = 0; i < num_buckets; i++) {
76 make_empty_list(& ht->buckets[i]);
77 }
78 }
79
80 return ht;
81 }
82
83
84 void
hash_table_dtor(struct hash_table * ht)85 hash_table_dtor(struct hash_table *ht)
86 {
87 hash_table_clear(ht);
88 free(ht);
89 }
90
91
92 void
hash_table_clear(struct hash_table * ht)93 hash_table_clear(struct hash_table *ht)
94 {
95 struct node *node;
96 struct node *temp;
97 unsigned i;
98
99
100 for (i = 0; i < ht->num_buckets; i++) {
101 foreach_s(node, temp, & ht->buckets[i]) {
102 remove_from_list(node);
103 free(node);
104 }
105
106 assert(is_empty_list(& ht->buckets[i]));
107 }
108 }
109
110
111 void *
hash_table_find(struct hash_table * ht,const void * key)112 hash_table_find(struct hash_table *ht, const void *key)
113 {
114 const unsigned hash_value = (*ht->hash)(key);
115 const unsigned bucket = hash_value % ht->num_buckets;
116 struct node *node;
117
118 foreach(node, & ht->buckets[bucket]) {
119 struct hash_node *hn = (struct hash_node *) node;
120
121 if ((*ht->compare)(hn->key, key) == 0) {
122 return hn->data;
123 }
124 }
125
126 return NULL;
127 }
128
129
130 void
hash_table_insert(struct hash_table * ht,void * data,const void * key)131 hash_table_insert(struct hash_table *ht, void *data, const void *key)
132 {
133 const unsigned hash_value = (*ht->hash)(key);
134 const unsigned bucket = hash_value % ht->num_buckets;
135 struct hash_node *node;
136
137 node = calloc(1, sizeof(*node));
138
139 node->data = data;
140 node->key = key;
141
142 insert_at_head(& ht->buckets[bucket], & node->link);
143 }
144
145 void
hash_table_remove(struct hash_table * ht,const void * key)146 hash_table_remove(struct hash_table *ht, const void *key)
147 {
148 const unsigned hash_value = (*ht->hash)(key);
149 const unsigned bucket = hash_value % ht->num_buckets;
150 struct node *node;
151
152 foreach(node, & ht->buckets[bucket]) {
153 struct hash_node *hn = (struct hash_node *) node;
154
155 if ((*ht->compare)(hn->key, key) == 0) {
156 remove_from_list(node);
157 free(node);
158 return;
159 }
160 }
161 }
162
163 unsigned
hash_table_string_hash(const void * key)164 hash_table_string_hash(const void *key)
165 {
166 const char *str = (const char *) key;
167 unsigned hash = 5381;
168
169
170 while (*str != '\0') {
171 hash = (hash * 33) + *str;
172 str++;
173 }
174
175 return hash;
176 }
177
178
179 unsigned
hash_table_pointer_hash(const void * key)180 hash_table_pointer_hash(const void *key)
181 {
182 return (unsigned)((uintptr_t) key / sizeof(void *));
183 }
184
185
186 int
hash_table_pointer_compare(const void * key1,const void * key2)187 hash_table_pointer_compare(const void *key1, const void *key2)
188 {
189 return key1 == key2 ? 0 : 1;
190 }
191