Remove incorrect assert in hash table lookup
[lttng-tools.git] / liblttng-ht / lttng-ht.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License as published by the Free
6 * Software Foundation; only version 2 of the License.
7 *
8 * This program is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
15 * Place - Suite 330, Boston, MA 02111-1307, USA.
16 */
17
18 #define _GNU_SOURCE
19 #include <assert.h>
20 #include <string.h>
21 #include <urcu.h>
22 #include <urcu/compiler.h>
23
24 #include <lttng-ht.h>
25 #include <lttng-share.h>
26 #include <lttngerr.h>
27
28 #include "utils.h"
29
30 #define HASH_SEED 0x42UL /* The answer to life */
31
32 static unsigned long min_hash_alloc_size = 1;
33 static unsigned long max_hash_buckets_size = (1UL << 20);
34
35 /*
36 * Match function for string node.
37 */
38 static int match_str(struct cds_lfht_node *node, const void *key)
39 {
40 struct lttng_ht_node_str *match_node =
41 caa_container_of(node, struct lttng_ht_node_str, node);
42
43 return hash_match_key_str(match_node->key, (void *) key);
44 }
45
46 /*
47 * Match function for ulong node.
48 */
49 static int match_ulong(struct cds_lfht_node *node, const void *key)
50 {
51 struct lttng_ht_node_ulong *match_node =
52 caa_container_of(node, struct lttng_ht_node_ulong, node);
53
54 return hash_match_key_ulong((void *) match_node->key, (void *) key);
55 }
56
57 /*
58 * Return an allocated lttng hashtable.
59 */
60 struct lttng_ht *lttng_ht_new(unsigned long size, int type)
61 {
62 struct lttng_ht *ht;
63
64 /* Test size */
65 size != 0 ? : (size = DEFAULT_HT_SIZE);
66
67 ht = zmalloc(sizeof(*ht));
68 if (ht == NULL) {
69 PERROR("zmalloc lttng_ht");
70 goto error;
71 }
72
73 ht->ht = cds_lfht_new(size, min_hash_alloc_size, max_hash_buckets_size,
74 CDS_LFHT_AUTO_RESIZE, NULL);
75 /*
76 * There is already an assert in the RCU hashtable code so if the ht is
77 * NULL here there is a *huge* problem.
78 */
79 assert(ht->ht);
80
81 switch (type) {
82 case LTTNG_HT_TYPE_STRING:
83 ht->match_fct = match_str;
84 ht->hash_fct = hash_key_str;
85 break;
86 case LTTNG_HT_TYPE_ULONG:
87 ht->match_fct = match_ulong;
88 ht->hash_fct = hash_key_ulong;
89 break;
90 default:
91 ERR("Unknown lttng hashtable type %d", type);
92 goto error;
93 }
94
95 DBG3("Created hashtable size %lu at %p of type %d", size, ht->ht, type);
96
97 return ht;
98
99 error:
100 return NULL;
101 }
102
103 /*
104 * Free a lttng hashtable.
105 */
106 void lttng_ht_destroy(struct lttng_ht *ht)
107 {
108 int ret;
109
110 ret = cds_lfht_destroy(ht->ht, NULL);
111 assert(!ret);
112 }
113
114 /*
115 * Init lttng ht node string.
116 */
117 void lttng_ht_node_init_str(struct lttng_ht_node_str *node, char *key)
118 {
119 assert(node);
120
121 node->key = key;
122 cds_lfht_node_init(&node->node);
123 }
124
125 /*
126 * Init lttng ht node unsigned long.
127 */
128 void lttng_ht_node_init_ulong(struct lttng_ht_node_ulong *node,
129 unsigned long key)
130 {
131 assert(node);
132
133 node->key = key;
134 cds_lfht_node_init(&node->node);
135 }
136
137 /*
138 * Free lttng ht node string.
139 */
140 void lttng_ht_node_free_str(struct lttng_ht_node_str *node)
141 {
142 assert(node);
143 free(node);
144 }
145
146 /*
147 * Free lttng ht node unsigned long.
148 */
149 void lttng_ht_node_free_ulong(struct lttng_ht_node_ulong *node)
150 {
151 assert(node);
152 free(node);
153 }
154
155 /*
156 * Lookup function in hashtable.
157 */
158 void lttng_ht_lookup(struct lttng_ht *ht, void *key,
159 struct lttng_ht_iter *iter)
160 {
161 assert(ht);
162 assert(ht->ht);
163
164 cds_lfht_lookup(ht->ht, ht->hash_fct(key, HASH_SEED),
165 ht->match_fct, key, &iter->iter);
166 }
167
168 /*
169 * Add unique string node to hashtable.
170 */
171 void lttng_ht_add_unique_str(struct lttng_ht *ht,
172 struct lttng_ht_node_str *node)
173 {
174 struct cds_lfht_node *node_ptr;
175 assert(ht);
176 assert(ht->ht);
177 assert(node);
178
179 node_ptr = cds_lfht_add_unique(ht->ht, ht->hash_fct(node->key, HASH_SEED),
180 ht->match_fct, node->key, &node->node);
181 assert(node_ptr == &node->node);
182 }
183
184 /*
185 * Add unique unsigned long node to hashtable.
186 */
187 void lttng_ht_add_unique_ulong(struct lttng_ht *ht,
188 struct lttng_ht_node_ulong *node)
189 {
190 struct cds_lfht_node *node_ptr;
191 assert(ht);
192 assert(ht->ht);
193 assert(node);
194
195 node_ptr = cds_lfht_add_unique(ht->ht,
196 ht->hash_fct((void *) node->key, HASH_SEED), ht->match_fct,
197 (void *) node->key, &node->node);
198 assert(node_ptr == &node->node);
199 }
200
201 /*
202 * Delete node from hashtable.
203 */
204 int lttng_ht_del(struct lttng_ht *ht, struct lttng_ht_iter *iter)
205 {
206 assert(ht);
207 assert(ht->ht);
208 assert(iter);
209
210 return cds_lfht_del(ht->ht, iter->iter.node);
211 }
212
213 /*
214 * Get first node in the hashtable.
215 */
216 void lttng_ht_get_first(struct lttng_ht *ht, struct lttng_ht_iter *iter)
217 {
218 assert(ht);
219 assert(ht->ht);
220 assert(iter);
221
222 cds_lfht_first(ht->ht, &iter->iter);
223 }
224
225 /*
226 * Get next node in the hashtable.
227 */
228 void lttng_ht_get_next(struct lttng_ht *ht, struct lttng_ht_iter *iter)
229 {
230 assert(ht);
231 assert(ht->ht);
232 assert(iter);
233
234 cds_lfht_next(ht->ht, &iter->iter);
235 }
236
237 /*
238 * Return the number of nodes in the hashtable.
239 */
240 unsigned long lttng_ht_get_count(struct lttng_ht *ht)
241 {
242 long scb, sca;
243 unsigned long count;
244
245 assert(ht);
246 assert(ht->ht);
247
248 cds_lfht_count_nodes(ht->ht, &scb, &count, &sca);
249
250 return count;
251 }
252
253 /*
254 * Return lttng ht string node from iterator.
255 */
256 struct lttng_ht_node_str *lttng_ht_iter_get_node_str(
257 struct lttng_ht_iter *iter)
258 {
259 struct cds_lfht_node *node;
260
261 assert(iter);
262 node = cds_lfht_iter_get_node(&iter->iter);
263 if (!node) {
264 return NULL;
265 }
266 return caa_container_of(node, struct lttng_ht_node_str, node);
267 }
268
269 /*
270 * Return lttng ht unsigned long node from iterator.
271 */
272 struct lttng_ht_node_ulong *lttng_ht_iter_get_node_ulong(
273 struct lttng_ht_iter *iter)
274 {
275 struct cds_lfht_node *node;
276
277 assert(iter);
278 node = cds_lfht_iter_get_node(&iter->iter);
279 if (!node) {
280 return NULL;
281 }
282 return caa_container_of(node, struct lttng_ht_node_ulong, node);
283 }
This page took 0.049217 seconds and 4 git commands to generate.