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git.proxmox.com Git - ovs.git/blob - lib/sset.c
2 * Copyright (c) 2011, 2012, 2013 Nicira, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
24 hash_name__(const char *name
, size_t length
)
26 return hash_bytes(name
, length
, 0);
30 hash_name(const char *name
)
32 return hash_name__(name
, strlen(name
));
35 static struct sset_node
*
36 sset_find__(const struct sset
*set
, const char *name
, size_t hash
)
38 struct sset_node
*node
;
40 HMAP_FOR_EACH_WITH_HASH (node
, hmap_node
, hash
, &set
->map
) {
41 if (!strcmp(node
->name
, name
)) {
48 static struct sset_node
*
49 sset_add__(struct sset
*set
, const char *name
, size_t length
, size_t hash
)
51 struct sset_node
*node
= xmalloc(length
+ sizeof *node
);
52 memcpy(node
->name
, name
, length
+ 1);
53 hmap_insert(&set
->map
, &node
->hmap_node
, hash
);
57 /* Initializes 'set' as an empty set of strings. */
59 sset_init(struct sset
*set
)
64 /* Destroys 'sets'. */
66 sset_destroy(struct sset
*set
)
70 hmap_destroy(&set
->map
);
74 /* Initializes 'set' to contain the same strings as 'orig'. */
76 sset_clone(struct sset
*set
, const struct sset
*orig
)
78 struct sset_node
*node
;
81 HMAP_FOR_EACH (node
, hmap_node
, &orig
->map
) {
82 sset_add__(set
, node
->name
, strlen(node
->name
),
83 node
->hmap_node
.hash
);
87 /* Exchanges the contents of 'a' and 'b'. */
89 sset_swap(struct sset
*a
, struct sset
*b
)
91 hmap_swap(&a
->map
, &b
->map
);
94 /* Adjusts 'set' so that it is still valid after it has been moved around in
95 * memory (e.g. due to realloc()). */
97 sset_moved(struct sset
*set
)
99 hmap_moved(&set
->map
);
102 /* Returns true if 'set' contains no strings, false if it contains at least one
105 sset_is_empty(const struct sset
*set
)
107 return hmap_is_empty(&set
->map
);
110 /* Returns the number of strings in 'set'. */
112 sset_count(const struct sset
*set
)
114 return hmap_count(&set
->map
);
117 /* Adds 'name' to 'set'. If 'name' is new, returns the new sset_node;
118 * otherwise (if a copy of 'name' already existed in 'set'), returns NULL. */
120 sset_add(struct sset
*set
, const char *name
)
122 size_t length
= strlen(name
);
123 uint32_t hash
= hash_name__(name
, length
);
125 return (sset_find__(set
, name
, hash
)
127 : sset_add__(set
, name
, length
, hash
));
130 /* Adds a copy of 'name' to 'set' and frees 'name'.
132 * If 'name' is new, returns the new sset_node; otherwise (if a copy of 'name'
133 * already existed in 'set'), returns NULL. */
135 sset_add_and_free(struct sset
*set
, char *name
)
137 struct sset_node
*node
= sset_add(set
, name
);
142 /* Adds 'name' to 'set'. Assert-fails if a copy of 'name' was already in
145 sset_add_assert(struct sset
*set
, const char *name
)
147 bool added OVS_UNUSED
= sset_add(set
, name
);
151 /* Adds a copy of each of the 'n' names in 'names' to 'set'. */
153 sset_add_array(struct sset
*set
, char **names
, size_t n
)
157 for (i
= 0; i
< n
; i
++) {
158 sset_add(set
, names
[i
]);
162 /* Removes all of the strings from 'set'. */
164 sset_clear(struct sset
*set
)
166 const char *name
, *next
;
168 SSET_FOR_EACH_SAFE (name
, next
, set
) {
169 sset_delete(set
, SSET_NODE_FROM_NAME(name
));
173 /* Deletes 'node' from 'set' and frees 'node'. */
175 sset_delete(struct sset
*set
, struct sset_node
*node
)
177 hmap_remove(&set
->map
, &node
->hmap_node
);
181 /* Searches for 'name' in 'set'. If found, deletes it and returns true. If
182 * not found, returns false without modifying 'set'. */
184 sset_find_and_delete(struct sset
*set
, const char *name
)
186 struct sset_node
*node
= sset_find(set
, name
);
188 sset_delete(set
, node
);
193 /* Searches for 'name' in 'set' and deletes it. Assert-fails if 'name' is not
196 sset_find_and_delete_assert(struct sset
*set
, const char *name
)
198 bool deleted OVS_UNUSED
= sset_find_and_delete(set
, name
);
202 /* Removes a string from 'set' and returns a copy of it. The caller must free
203 * the returned string (with free()).
205 * 'set' must not be empty.
207 * This is not a very good way to iterate through an sset: it copies each name
208 * and it takes O(n**2) time to remove all the names. Use SSET_FOR_EACH_SAFE
209 * instead, if you can. */
211 sset_pop(struct sset
*set
)
213 const char *name
= SSET_FIRST(set
);
214 char *copy
= xstrdup(name
);
215 sset_delete(set
, SSET_NODE_FROM_NAME(name
));
219 /* Searches for 'name' in 'set'. Returns its node, if found, otherwise a null
222 sset_find(const struct sset
*set
, const char *name
)
224 return sset_find__(set
, name
, hash_name(name
));
227 /* Returns true if 'set' contains a copy of 'name', false otherwise. */
229 sset_contains(const struct sset
*set
, const char *name
)
231 return sset_find(set
, name
) != NULL
;
234 /* Returns true if 'a' and 'b' contain the same strings, false otherwise. */
236 sset_equals(const struct sset
*a
, const struct sset
*b
)
238 struct sset_node
*node
;
240 if (sset_count(a
) != sset_count(b
)) {
244 HMAP_FOR_EACH (node
, hmap_node
, &a
->map
) {
245 if (!sset_find__(b
, node
->name
, node
->hmap_node
.hash
)) {
253 /* Returns the next node in 'set' in hash order, or NULL if no nodes remain in
254 * 'set'. Uses '*bucketp' and '*offsetp' to determine where to begin
255 * iteration, and stores new values to pass on the next iteration into them
258 * It's better to use plain SSET_FOR_EACH and related functions, since they are
259 * faster and better at dealing with ssets that change during iteration.
261 * Before beginning iteration, store 0 into '*bucketp' and '*offsetp'.
264 sset_at_position(const struct sset
*set
, uint32_t *bucketp
, uint32_t *offsetp
)
266 struct hmap_node
*hmap_node
;
268 hmap_node
= hmap_at_position(&set
->map
, bucketp
, offsetp
);
269 return SSET_NODE_FROM_HMAP_NODE(hmap_node
);
273 compare_string_pointers(const void *a_
, const void *b_
)
275 const char *const *a
= a_
;
276 const char *const *b
= b_
;
278 return strcmp(*a
, *b
);
281 /* Returns a null-terminated array of pointers to the strings in 'set', sorted
282 * alphabetically. The caller must free the returned array when it is no
283 * longer needed, but the strings in the array belong to 'set' and thus must
284 * not be modified or freed. */
286 sset_sort(const struct sset
*set
)
288 size_t n
= sset_count(set
);
293 array
= xmalloc(sizeof *array
* (n
+ 1));
295 SSET_FOR_EACH (s
, set
) {
301 qsort(array
, n
, sizeof *array
, compare_string_pointers
);