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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 | /* |
29 | /* |
30 | * This is an implementation of generic chained hash table. |
30 | * This is an implementation of generic chained hash table. |
31 | */ |
31 | */ |
32 | 32 | ||
33 | #include <adt/hash_table.h> |
33 | #include <adt/hash_table.h> |
34 | #include <adt/list.h> |
34 | #include <adt/list.h> |
35 | #include <typedefs.h> |
35 | #include <typedefs.h> |
36 | #include <arch/types.h> |
36 | #include <arch/types.h> |
37 | #include <debug.h> |
37 | #include <debug.h> |
38 | #include <mm/heap.h> |
38 | #include <mm/slab.h> |
39 | #include <memstr.h> |
39 | #include <memstr.h> |
40 | 40 | ||
41 | /** Create chained hash table. |
41 | /** Create chained hash table. |
42 | * |
42 | * |
43 | * @param h Hash table structure. Will be initialized by this call. |
43 | * @param h Hash table structure. Will be initialized by this call. |
44 | * @param m Number of slots in the hash table. |
44 | * @param m Number of slots in the hash table. |
45 | * @param max_keys Maximal number of keys needed to identify an item. |
45 | * @param max_keys Maximal number of keys needed to identify an item. |
46 | * @param op Hash table operations structure. |
46 | * @param op Hash table operations structure. |
47 | */ |
47 | */ |
48 | void hash_table_create(hash_table_t *h, count_t m, count_t max_keys, hash_table_operations_t *op) |
48 | void hash_table_create(hash_table_t *h, count_t m, count_t max_keys, hash_table_operations_t *op) |
49 | { |
49 | { |
50 | ASSERT(h); |
50 | ASSERT(h); |
51 | ASSERT(op && op->hash && op->compare); |
51 | ASSERT(op && op->hash && op->compare); |
52 | ASSERT(max_keys > 0); |
52 | ASSERT(max_keys > 0); |
53 | 53 | ||
54 | h->entry = malloc(m * sizeof(link_t *)); |
54 | h->entry = malloc(m * sizeof(link_t *)); |
55 | if (!h->entry) { |
55 | if (!h->entry) { |
56 | panic("cannot allocate memory for hash table\n"); |
56 | panic("cannot allocate memory for hash table\n"); |
57 | } |
57 | } |
58 | memsetb((__address) h->entry, m * sizeof(link_t *), 0); |
58 | memsetb((__address) h->entry, m * sizeof(link_t *), 0); |
59 | 59 | ||
60 | h->entries = m; |
60 | h->entries = m; |
61 | h->max_keys = max_keys; |
61 | h->max_keys = max_keys; |
62 | h->op = op; |
62 | h->op = op; |
63 | } |
63 | } |
64 | 64 | ||
65 | /** Insert item into hash table. |
65 | /** Insert item into hash table. |
66 | * |
66 | * |
67 | * @param h Hash table. |
67 | * @param h Hash table. |
68 | * @param hey Array of all keys necessary to compute hash index. |
68 | * @param hey Array of all keys necessary to compute hash index. |
69 | * @param item Item to be inserted into the hash table. |
69 | * @param item Item to be inserted into the hash table. |
70 | */ |
70 | */ |
71 | void hash_table_insert(hash_table_t *h, __native key[], link_t *item) |
71 | void hash_table_insert(hash_table_t *h, __native key[], link_t *item) |
72 | { |
72 | { |
73 | index_t chain; |
73 | index_t chain; |
74 | 74 | ||
75 | ASSERT(item); |
75 | ASSERT(item); |
76 | ASSERT(h && h->op && h->op->hash && h->op->compare); |
76 | ASSERT(h && h->op && h->op->hash && h->op->compare); |
77 | 77 | ||
78 | chain = h->op->hash(key); |
78 | chain = h->op->hash(key); |
79 | ASSERT(chain < h->entries); |
79 | ASSERT(chain < h->entries); |
80 | 80 | ||
81 | list_append(item, &h->entry[chain]); |
81 | list_append(item, &h->entry[chain]); |
82 | } |
82 | } |
83 | 83 | ||
84 | /** Search hash table for an item matching keys. |
84 | /** Search hash table for an item matching keys. |
85 | * |
85 | * |
86 | * @param h Hash table. |
86 | * @param h Hash table. |
87 | * @param key Array of all keys needed to compute hash index. |
87 | * @param key Array of all keys needed to compute hash index. |
88 | * |
88 | * |
89 | * @return Matching item on success, NULL if there is no such item. |
89 | * @return Matching item on success, NULL if there is no such item. |
90 | */ |
90 | */ |
91 | link_t *hash_table_find(hash_table_t *h, __native key[]) |
91 | link_t *hash_table_find(hash_table_t *h, __native key[]) |
92 | { |
92 | { |
93 | link_t *cur; |
93 | link_t *cur; |
94 | index_t chain; |
94 | index_t chain; |
95 | 95 | ||
96 | ASSERT(h && h->op && h->op->hash && h->op->compare); |
96 | ASSERT(h && h->op && h->op->hash && h->op->compare); |
97 | 97 | ||
98 | chain = h->op->hash(key); |
98 | chain = h->op->hash(key); |
99 | ASSERT(chain < h->entries); |
99 | ASSERT(chain < h->entries); |
100 | 100 | ||
101 | /* |
101 | /* |
102 | * The hash table is not redundant. |
102 | * The hash table is not redundant. |
103 | * Check if the keys are not in place already. |
103 | * Check if the keys are not in place already. |
104 | */ |
104 | */ |
105 | for (cur = h->entry[chain].next; cur != &h->entry[chain]; cur = cur->next) { |
105 | for (cur = h->entry[chain].next; cur != &h->entry[chain]; cur = cur->next) { |
106 | if (h->op->compare(key, h->max_keys, cur)) { |
106 | if (h->op->compare(key, h->max_keys, cur)) { |
107 | /* |
107 | /* |
108 | * The entry is there. |
108 | * The entry is there. |
109 | */ |
109 | */ |
110 | return cur; |
110 | return cur; |
111 | } |
111 | } |
112 | } |
112 | } |
113 | 113 | ||
114 | return NULL; |
114 | return NULL; |
115 | } |
115 | } |
116 | 116 | ||
117 | /** Remove all matching items from hash table. |
117 | /** Remove all matching items from hash table. |
118 | * |
118 | * |
119 | * For each removed item, h->remove_callback() is called. |
119 | * For each removed item, h->remove_callback() is called. |
120 | * |
120 | * |
121 | * @param h Hash table. |
121 | * @param h Hash table. |
122 | * @param key Array of keys that will be compared against items of the hash table. |
122 | * @param key Array of keys that will be compared against items of the hash table. |
123 | * @param keys Number of keys in the 'key' array. |
123 | * @param keys Number of keys in the 'key' array. |
124 | */ |
124 | */ |
125 | void hash_table_remove(hash_table_t *h, __native key[], count_t keys) |
125 | void hash_table_remove(hash_table_t *h, __native key[], count_t keys) |
126 | { |
126 | { |
127 | index_t chain; |
127 | index_t chain; |
128 | link_t *cur; |
128 | link_t *cur; |
129 | 129 | ||
130 | ASSERT(h && h->op && h->op->hash && h->op->compare && h->op->remove_callback); |
130 | ASSERT(h && h->op && h->op->hash && h->op->compare && h->op->remove_callback); |
131 | ASSERT(keys <= h->max_keys); |
131 | ASSERT(keys <= h->max_keys); |
132 | 132 | ||
133 | if (keys == h->max_keys) { |
133 | if (keys == h->max_keys) { |
134 | 134 | ||
135 | /* |
135 | /* |
136 | * All keys are known, hash_table_find() can be used to find the entry. |
136 | * All keys are known, hash_table_find() can be used to find the entry. |
137 | */ |
137 | */ |
138 | 138 | ||
139 | cur = hash_table_find(h, key); |
139 | cur = hash_table_find(h, key); |
140 | if (cur) { |
140 | if (cur) { |
141 | list_remove(cur); |
141 | list_remove(cur); |
142 | h->op->remove_callback(cur); |
142 | h->op->remove_callback(cur); |
143 | } |
143 | } |
144 | return; |
144 | return; |
145 | } |
145 | } |
146 | 146 | ||
147 | /* |
147 | /* |
148 | * Fewer keys were passed. |
148 | * Fewer keys were passed. |
149 | * Any partially matching entries are to be removed. |
149 | * Any partially matching entries are to be removed. |
150 | */ |
150 | */ |
151 | for (chain = 0; chain < h->entries; chain++) { |
151 | for (chain = 0; chain < h->entries; chain++) { |
152 | for (cur = h->entry[chain].next; cur != &h->entry[chain]; cur = cur->next) { |
152 | for (cur = h->entry[chain].next; cur != &h->entry[chain]; cur = cur->next) { |
153 | if (h->op->compare(key, keys, cur)) { |
153 | if (h->op->compare(key, keys, cur)) { |
154 | link_t *hlp; |
154 | link_t *hlp; |
155 | 155 | ||
156 | hlp = cur; |
156 | hlp = cur; |
157 | cur = cur->prev; |
157 | cur = cur->prev; |
158 | 158 | ||
159 | list_remove(hlp); |
159 | list_remove(hlp); |
160 | h->op->remove_callback(hlp); |
160 | h->op->remove_callback(hlp); |
161 | 161 | ||
162 | continue; |
162 | continue; |
163 | } |
163 | } |
164 | } |
164 | } |
165 | } |
165 | } |
166 | } |
166 | } |
167 | 167 |