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1 | /* |
1 | /* |
2 | * Copyright (c) 2008 Jakub Jermar |
2 | * Copyright (c) 2008 Jakub Jermar |
3 | * All rights reserved. |
3 | * All rights reserved. |
4 | * |
4 | * |
5 | * Redistribution and use in source and binary forms, with or without |
5 | * Redistribution and use in source and binary forms, with or without |
6 | * modification, are permitted provided that the following conditions |
6 | * modification, are permitted provided that the following conditions |
7 | * are met: |
7 | * are met: |
8 | * |
8 | * |
9 | * - Redistributions of source code must retain the above copyright |
9 | * - Redistributions of source code must retain the above copyright |
10 | * notice, this list of conditions and the following disclaimer. |
10 | * notice, this list of conditions and the following disclaimer. |
11 | * - Redistributions in binary form must reproduce the above copyright |
11 | * - Redistributions in binary form must reproduce the above copyright |
12 | * notice, this list of conditions and the following disclaimer in the |
12 | * notice, this list of conditions and the following disclaimer in the |
13 | * documentation and/or other materials provided with the distribution. |
13 | * documentation and/or other materials provided with the distribution. |
14 | * - The name of the author may not be used to endorse or promote products |
14 | * - The name of the author may not be used to endorse or promote products |
15 | * derived from this software without specific prior written permission. |
15 | * derived from this software without specific prior written permission. |
16 | * |
16 | * |
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
27 | */ |
27 | */ |
28 | 28 | ||
29 | /** @addtogroup libc |
29 | /** @addtogroup libc |
30 | * @{ |
30 | * @{ |
31 | */ |
31 | */ |
32 | /** @file |
32 | /** @file |
33 | */ |
33 | */ |
34 | 34 | ||
35 | /* |
35 | /* |
36 | * This is an implementation of generic chained hash table. |
36 | * This is an implementation of generic chained hash table. |
37 | */ |
37 | */ |
38 | 38 | ||
39 | #include <libadt/hash_table.h> |
39 | #include <adt/hash_table.h> |
40 | #include <libadt/list.h> |
40 | #include <adt/list.h> |
41 | #include <unistd.h> |
41 | #include <unistd.h> |
42 | #include <malloc.h> |
42 | #include <malloc.h> |
43 | #include <assert.h> |
43 | #include <assert.h> |
44 | #include <stdio.h> |
44 | #include <stdio.h> |
45 | #include <string.h> |
45 | #include <string.h> |
46 | 46 | ||
47 | /** Create chained hash table. |
47 | /** Create chained hash table. |
48 | * |
48 | * |
49 | * @param h Hash table structure. Will be initialized by this call. |
49 | * @param h Hash table structure. Will be initialized by this call. |
50 | * @param m Number of hash table buckets. |
50 | * @param m Number of hash table buckets. |
51 | * @param max_keys Maximal number of keys needed to identify an item. |
51 | * @param max_keys Maximal number of keys needed to identify an item. |
52 | * @param op Hash table operations structure. |
52 | * @param op Hash table operations structure. |
53 | * @return True on success |
53 | * @return True on success |
54 | */ |
54 | */ |
55 | int hash_table_create(hash_table_t *h, hash_count_t m, hash_count_t max_keys, |
55 | int hash_table_create(hash_table_t *h, hash_count_t m, hash_count_t max_keys, |
56 | hash_table_operations_t *op) |
56 | hash_table_operations_t *op) |
57 | { |
57 | { |
58 | hash_count_t i; |
58 | hash_count_t i; |
59 | 59 | ||
60 | assert(h); |
60 | assert(h); |
61 | assert(op && op->hash && op->compare); |
61 | assert(op && op->hash && op->compare); |
62 | assert(max_keys > 0); |
62 | assert(max_keys > 0); |
63 | 63 | ||
64 | h->entry = malloc(m * sizeof(link_t)); |
64 | h->entry = malloc(m * sizeof(link_t)); |
65 | if (!h->entry) { |
65 | if (!h->entry) { |
66 | printf("cannot allocate memory for hash table\n"); |
66 | printf("cannot allocate memory for hash table\n"); |
67 | return false; |
67 | return false; |
68 | } |
68 | } |
69 | memset((void *) h->entry, 0, m * sizeof(link_t)); |
69 | memset((void *) h->entry, 0, m * sizeof(link_t)); |
70 | 70 | ||
71 | for (i = 0; i < m; i++) |
71 | for (i = 0; i < m; i++) |
72 | list_initialize(&h->entry[i]); |
72 | list_initialize(&h->entry[i]); |
73 | 73 | ||
74 | h->entries = m; |
74 | h->entries = m; |
75 | h->max_keys = max_keys; |
75 | h->max_keys = max_keys; |
76 | h->op = op; |
76 | h->op = op; |
77 | return true; |
77 | return true; |
78 | } |
78 | } |
79 | 79 | ||
80 | /** Destroy a hash table instance. |
80 | /** Destroy a hash table instance. |
81 | * |
81 | * |
82 | * @param h Hash table to be destroyed. |
82 | * @param h Hash table to be destroyed. |
83 | */ |
83 | */ |
84 | void hash_table_destroy(hash_table_t *h) |
84 | void hash_table_destroy(hash_table_t *h) |
85 | { |
85 | { |
86 | assert(h); |
86 | assert(h); |
87 | assert(h->entry); |
87 | assert(h->entry); |
88 | free(h->entry); |
88 | free(h->entry); |
89 | } |
89 | } |
90 | 90 | ||
91 | /** Insert item into a hash table. |
91 | /** Insert item into a hash table. |
92 | * |
92 | * |
93 | * @param h Hash table. |
93 | * @param h Hash table. |
94 | * @param key Array of all keys necessary to compute hash index. |
94 | * @param key Array of all keys necessary to compute hash index. |
95 | * @param item Item to be inserted into the hash table. |
95 | * @param item Item to be inserted into the hash table. |
96 | */ |
96 | */ |
97 | void hash_table_insert(hash_table_t *h, unsigned long key[], link_t *item) |
97 | void hash_table_insert(hash_table_t *h, unsigned long key[], link_t *item) |
98 | { |
98 | { |
99 | hash_index_t chain; |
99 | hash_index_t chain; |
100 | 100 | ||
101 | assert(item); |
101 | assert(item); |
102 | assert(h && h->op && h->op->hash && h->op->compare); |
102 | assert(h && h->op && h->op->hash && h->op->compare); |
103 | 103 | ||
104 | chain = h->op->hash(key); |
104 | chain = h->op->hash(key); |
105 | assert(chain < h->entries); |
105 | assert(chain < h->entries); |
106 | 106 | ||
107 | list_append(item, &h->entry[chain]); |
107 | list_append(item, &h->entry[chain]); |
108 | } |
108 | } |
109 | 109 | ||
110 | /** Search hash table for an item matching keys. |
110 | /** Search hash table for an item matching keys. |
111 | * |
111 | * |
112 | * @param h Hash table. |
112 | * @param h Hash table. |
113 | * @param key Array of all keys needed to compute hash index. |
113 | * @param key Array of all keys needed to compute hash index. |
114 | * |
114 | * |
115 | * @return Matching item on success, NULL if there is no such item. |
115 | * @return Matching item on success, NULL if there is no such item. |
116 | */ |
116 | */ |
117 | link_t *hash_table_find(hash_table_t *h, unsigned long key[]) |
117 | link_t *hash_table_find(hash_table_t *h, unsigned long key[]) |
118 | { |
118 | { |
119 | link_t *cur; |
119 | link_t *cur; |
120 | hash_index_t chain; |
120 | hash_index_t chain; |
121 | 121 | ||
122 | assert(h && h->op && h->op->hash && h->op->compare); |
122 | assert(h && h->op && h->op->hash && h->op->compare); |
123 | 123 | ||
124 | chain = h->op->hash(key); |
124 | chain = h->op->hash(key); |
125 | assert(chain < h->entries); |
125 | assert(chain < h->entries); |
126 | 126 | ||
127 | for (cur = h->entry[chain].next; cur != &h->entry[chain]; |
127 | for (cur = h->entry[chain].next; cur != &h->entry[chain]; |
128 | cur = cur->next) { |
128 | cur = cur->next) { |
129 | if (h->op->compare(key, h->max_keys, cur)) { |
129 | if (h->op->compare(key, h->max_keys, cur)) { |
130 | /* |
130 | /* |
131 | * The entry is there. |
131 | * The entry is there. |
132 | */ |
132 | */ |
133 | return cur; |
133 | return cur; |
134 | } |
134 | } |
135 | } |
135 | } |
136 | 136 | ||
137 | return NULL; |
137 | return NULL; |
138 | } |
138 | } |
139 | 139 | ||
140 | /** Remove all matching items from hash table. |
140 | /** Remove all matching items from hash table. |
141 | * |
141 | * |
142 | * For each removed item, h->remove_callback() is called. |
142 | * For each removed item, h->remove_callback() is called. |
143 | * |
143 | * |
144 | * @param h Hash table. |
144 | * @param h Hash table. |
145 | * @param key Array of keys that will be compared against items of |
145 | * @param key Array of keys that will be compared against items of |
146 | * the hash table. |
146 | * the hash table. |
147 | * @param keys Number of keys in the 'key' array. |
147 | * @param keys Number of keys in the 'key' array. |
148 | */ |
148 | */ |
149 | void hash_table_remove(hash_table_t *h, unsigned long key[], hash_count_t keys) |
149 | void hash_table_remove(hash_table_t *h, unsigned long key[], hash_count_t keys) |
150 | { |
150 | { |
151 | hash_index_t chain; |
151 | hash_index_t chain; |
152 | link_t *cur; |
152 | link_t *cur; |
153 | 153 | ||
154 | assert(h && h->op && h->op->hash && h->op->compare && |
154 | assert(h && h->op && h->op->hash && h->op->compare && |
155 | h->op->remove_callback); |
155 | h->op->remove_callback); |
156 | assert(keys <= h->max_keys); |
156 | assert(keys <= h->max_keys); |
157 | 157 | ||
158 | if (keys == h->max_keys) { |
158 | if (keys == h->max_keys) { |
159 | 159 | ||
160 | /* |
160 | /* |
161 | * All keys are known, hash_table_find() can be used to find the |
161 | * All keys are known, hash_table_find() can be used to find the |
162 | * entry. |
162 | * entry. |
163 | */ |
163 | */ |
164 | 164 | ||
165 | cur = hash_table_find(h, key); |
165 | cur = hash_table_find(h, key); |
166 | if (cur) { |
166 | if (cur) { |
167 | list_remove(cur); |
167 | list_remove(cur); |
168 | h->op->remove_callback(cur); |
168 | h->op->remove_callback(cur); |
169 | } |
169 | } |
170 | return; |
170 | return; |
171 | } |
171 | } |
172 | 172 | ||
173 | /* |
173 | /* |
174 | * Fewer keys were passed. |
174 | * Fewer keys were passed. |
175 | * Any partially matching entries are to be removed. |
175 | * Any partially matching entries are to be removed. |
176 | */ |
176 | */ |
177 | for (chain = 0; chain < h->entries; chain++) { |
177 | for (chain = 0; chain < h->entries; chain++) { |
178 | for (cur = h->entry[chain].next; cur != &h->entry[chain]; |
178 | for (cur = h->entry[chain].next; cur != &h->entry[chain]; |
179 | cur = cur->next) { |
179 | cur = cur->next) { |
180 | if (h->op->compare(key, keys, cur)) { |
180 | if (h->op->compare(key, keys, cur)) { |
181 | link_t *hlp; |
181 | link_t *hlp; |
182 | 182 | ||
183 | hlp = cur; |
183 | hlp = cur; |
184 | cur = cur->prev; |
184 | cur = cur->prev; |
185 | 185 | ||
186 | list_remove(hlp); |
186 | list_remove(hlp); |
187 | h->op->remove_callback(hlp); |
187 | h->op->remove_callback(hlp); |
188 | 188 | ||
189 | continue; |
189 | continue; |
190 | } |
190 | } |
191 | } |
191 | } |
192 | } |
192 | } |
193 | } |
193 | } |
194 | 194 | ||
195 | /** @} |
195 | /** @} |
196 | */ |
196 | */ |
197 | 197 |