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1 | /* |
1 | /* |
2 | * Copyright (C) 2006 Jakub Jermar |
2 | * Copyright (C) 2006 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 <libadt/hash_table.h> |
40 | #include <libadt/list.h> |
40 | #include <libadt/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 slots in the hash table. |
50 | * @param m Number of slots in the hash table. |
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, hash_table_operations_t *op) |
55 | int hash_table_create(hash_table_t *h, hash_count_t m, hash_count_t max_keys, hash_table_operations_t *op) |
56 | { |
56 | { |
57 | hash_count_t i; |
57 | hash_count_t i; |
58 | 58 | ||
59 | assert(h); |
59 | assert(h); |
60 | assert(op && op->hash && op->compare); |
60 | assert(op && op->hash && op->compare); |
61 | assert(max_keys > 0); |
61 | assert(max_keys > 0); |
62 | 62 | ||
63 | h->entry = malloc(m * sizeof(link_t)); |
63 | h->entry = malloc(m * sizeof(link_t)); |
64 | if (!h->entry) { |
64 | if (!h->entry) { |
65 | printf("cannot allocate memory for hash table\n"); |
65 | printf("cannot allocate memory for hash table\n"); |
66 | return false; |
66 | return false; |
67 | } |
67 | } |
68 | memset((void *) h->entry, 0, m * sizeof(link_t)); |
68 | memset((void *) h->entry, 0, m * sizeof(link_t)); |
69 | 69 | ||
70 | for (i = 0; i < m; i++) |
70 | for (i = 0; i < m; i++) |
71 | list_initialize(&h->entry[i]); |
71 | list_initialize(&h->entry[i]); |
72 | 72 | ||
73 | h->entries = m; |
73 | h->entries = m; |
74 | h->max_keys = max_keys; |
74 | h->max_keys = max_keys; |
75 | h->op = op; |
75 | h->op = op; |
76 | return true; |
76 | return true; |
77 | } |
77 | } |
78 | 78 | ||
79 | /** Insert item into hash table. |
79 | /** Insert item into hash table. |
80 | * |
80 | * |
81 | * @param h Hash table. |
81 | * @param h Hash table. |
82 | * @param hey Array of all keys necessary to compute hash index. |
82 | * @param key Array of all keys necessary to compute hash index. |
83 | * @param item Item to be inserted into the hash table. |
83 | * @param item Item to be inserted into the hash table. |
84 | */ |
84 | */ |
85 | void hash_table_insert(hash_table_t *h, unsigned long key[], link_t *item) |
85 | void hash_table_insert(hash_table_t *h, unsigned long key[], link_t *item) |
86 | { |
86 | { |
87 | hash_index_t chain; |
87 | hash_index_t chain; |
88 | 88 | ||
89 | assert(item); |
89 | assert(item); |
90 | assert(h && h->op && h->op->hash && h->op->compare); |
90 | assert(h && h->op && h->op->hash && h->op->compare); |
91 | 91 | ||
92 | chain = h->op->hash(key); |
92 | chain = h->op->hash(key); |
93 | assert(chain < h->entries); |
93 | assert(chain < h->entries); |
94 | 94 | ||
95 | list_append(item, &h->entry[chain]); |
95 | list_append(item, &h->entry[chain]); |
96 | } |
96 | } |
97 | 97 | ||
98 | /** Search hash table for an item matching keys. |
98 | /** Search hash table for an item matching keys. |
99 | * |
99 | * |
100 | * @param h Hash table. |
100 | * @param h Hash table. |
101 | * @param key Array of all keys needed to compute hash index. |
101 | * @param key Array of all keys needed to compute hash index. |
102 | * |
102 | * |
103 | * @return Matching item on success, NULL if there is no such item. |
103 | * @return Matching item on success, NULL if there is no such item. |
104 | */ |
104 | */ |
105 | link_t *hash_table_find(hash_table_t *h, unsigned long key[]) |
105 | link_t *hash_table_find(hash_table_t *h, unsigned long key[]) |
106 | { |
106 | { |
107 | link_t *cur; |
107 | link_t *cur; |
108 | hash_index_t chain; |
108 | hash_index_t chain; |
109 | 109 | ||
110 | assert(h && h->op && h->op->hash && h->op->compare); |
110 | assert(h && h->op && h->op->hash && h->op->compare); |
111 | 111 | ||
112 | chain = h->op->hash(key); |
112 | chain = h->op->hash(key); |
113 | assert(chain < h->entries); |
113 | assert(chain < h->entries); |
114 | 114 | ||
115 | for (cur = h->entry[chain].next; cur != &h->entry[chain]; cur = cur->next) { |
115 | for (cur = h->entry[chain].next; cur != &h->entry[chain]; cur = cur->next) { |
116 | if (h->op->compare(key, h->max_keys, cur)) { |
116 | if (h->op->compare(key, h->max_keys, cur)) { |
117 | /* |
117 | /* |
118 | * The entry is there. |
118 | * The entry is there. |
119 | */ |
119 | */ |
120 | return cur; |
120 | return cur; |
121 | } |
121 | } |
122 | } |
122 | } |
123 | 123 | ||
124 | return NULL; |
124 | return NULL; |
125 | } |
125 | } |
126 | 126 | ||
127 | /** Remove all matching items from hash table. |
127 | /** Remove all matching items from hash table. |
128 | * |
128 | * |
129 | * For each removed item, h->remove_callback() is called. |
129 | * For each removed item, h->remove_callback() is called. |
130 | * |
130 | * |
131 | * @param h Hash table. |
131 | * @param h Hash table. |
132 | * @param key Array of keys that will be compared against items of the hash table. |
132 | * @param key Array of keys that will be compared against items of the hash table. |
133 | * @param keys Number of keys in the 'key' array. |
133 | * @param keys Number of keys in the 'key' array. |
134 | */ |
134 | */ |
135 | void hash_table_remove(hash_table_t *h, unsigned long key[], hash_count_t keys) |
135 | void hash_table_remove(hash_table_t *h, unsigned long key[], hash_count_t keys) |
136 | { |
136 | { |
137 | hash_index_t chain; |
137 | hash_index_t chain; |
138 | link_t *cur; |
138 | link_t *cur; |
139 | 139 | ||
140 | assert(h && h->op && h->op->hash && h->op->compare && h->op->remove_callback); |
140 | assert(h && h->op && h->op->hash && h->op->compare && h->op->remove_callback); |
141 | assert(keys <= h->max_keys); |
141 | assert(keys <= h->max_keys); |
142 | 142 | ||
143 | if (keys == h->max_keys) { |
143 | if (keys == h->max_keys) { |
144 | 144 | ||
145 | /* |
145 | /* |
146 | * All keys are known, hash_table_find() can be used to find the entry. |
146 | * All keys are known, hash_table_find() can be used to find the entry. |
147 | */ |
147 | */ |
148 | 148 | ||
149 | cur = hash_table_find(h, key); |
149 | cur = hash_table_find(h, key); |
150 | if (cur) { |
150 | if (cur) { |
151 | list_remove(cur); |
151 | list_remove(cur); |
152 | h->op->remove_callback(cur); |
152 | h->op->remove_callback(cur); |
153 | } |
153 | } |
154 | return; |
154 | return; |
155 | } |
155 | } |
156 | 156 | ||
157 | /* |
157 | /* |
158 | * Fewer keys were passed. |
158 | * Fewer keys were passed. |
159 | * Any partially matching entries are to be removed. |
159 | * Any partially matching entries are to be removed. |
160 | */ |
160 | */ |
161 | for (chain = 0; chain < h->entries; chain++) { |
161 | for (chain = 0; chain < h->entries; chain++) { |
162 | for (cur = h->entry[chain].next; cur != &h->entry[chain]; cur = cur->next) { |
162 | for (cur = h->entry[chain].next; cur != &h->entry[chain]; cur = cur->next) { |
163 | if (h->op->compare(key, keys, cur)) { |
163 | if (h->op->compare(key, keys, cur)) { |
164 | link_t *hlp; |
164 | link_t *hlp; |
165 | 165 | ||
166 | hlp = cur; |
166 | hlp = cur; |
167 | cur = cur->prev; |
167 | cur = cur->prev; |
168 | 168 | ||
169 | list_remove(hlp); |
169 | list_remove(hlp); |
170 | h->op->remove_callback(hlp); |
170 | h->op->remove_callback(hlp); |
171 | 171 | ||
172 | continue; |
172 | continue; |
173 | } |
173 | } |
174 | } |
174 | } |
175 | } |
175 | } |
176 | } |
176 | } |
177 | 177 | ||
178 | 178 | ||
179 | /** @} |
179 | /** @} |
180 | */ |
180 | */ |
181 | 181 | ||
182 | 182 | ||
183 | 183 |