2 * Copyright (c) 2009, 2010, 2011 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.
22 static struct shash_node *shash_find__(const struct shash *,
23 const char *name, size_t name_len,
27 hash_name(const char *name)
29 return hash_string(name, 0);
33 shash_init(struct shash *sh)
39 shash_destroy(struct shash *sh)
43 hmap_destroy(&sh->map);
47 /* Like shash_destroy(), but also free() each node's 'data'. */
49 shash_destroy_free_data(struct shash *sh)
52 shash_clear_free_data(sh);
53 hmap_destroy(&sh->map);
58 shash_swap(struct shash *a, struct shash *b)
60 hmap_swap(&a->map, &b->map);
64 shash_moved(struct shash *sh)
70 shash_clear(struct shash *sh)
72 struct shash_node *node, *next;
74 SHASH_FOR_EACH_SAFE (node, next, sh) {
75 hmap_remove(&sh->map, &node->node);
81 /* Like shash_clear(), but also free() each node's 'data'. */
83 shash_clear_free_data(struct shash *sh)
85 struct shash_node *node, *next;
87 SHASH_FOR_EACH_SAFE (node, next, sh) {
88 hmap_remove(&sh->map, &node->node);
96 shash_is_empty(const struct shash *shash)
98 return hmap_is_empty(&shash->map);
102 shash_count(const struct shash *shash)
104 return hmap_count(&shash->map);
107 static struct shash_node *
108 shash_add_nocopy__(struct shash *sh, char *name, const void *data, size_t hash)
110 struct shash_node *node = xmalloc(sizeof *node);
112 node->data = (void *) data;
113 hmap_insert(&sh->map, &node->node, hash);
117 /* It is the caller's responsibility to avoid duplicate names, if that is
120 shash_add_nocopy(struct shash *sh, char *name, const void *data)
122 return shash_add_nocopy__(sh, name, data, hash_name(name));
125 /* It is the caller's responsibility to avoid duplicate names, if that is
128 shash_add(struct shash *sh, const char *name, const void *data)
130 return shash_add_nocopy(sh, xstrdup(name), data);
134 shash_add_once(struct shash *sh, const char *name, const void *data)
136 if (!shash_find(sh, name)) {
137 shash_add(sh, name, data);
145 shash_add_assert(struct shash *sh, const char *name, const void *data)
147 bool added OVS_UNUSED = shash_add_once(sh, name, data);
151 /* Searches for 'name' in 'sh'. If it does not already exist, adds it along
152 * with 'data' and returns NULL. If it does already exist, replaces its data
153 * by 'data' and returns the data that it formerly contained. */
155 shash_replace(struct shash *sh, const char *name, const void *data)
157 size_t hash = hash_name(name);
158 struct shash_node *node;
160 node = shash_find__(sh, name, strlen(name), hash);
162 shash_add_nocopy__(sh, xstrdup(name), data, hash);
165 void *old_data = node->data;
166 node->data = (void *) data;
171 /* Deletes 'node' from 'sh' and frees the node's name. The caller is still
172 * responsible for freeing the node's data, if necessary. */
174 shash_delete(struct shash *sh, struct shash_node *node)
176 free(shash_steal(sh, node));
179 /* Deletes 'node' from 'sh'. Neither the node's name nor its data is freed;
180 * instead, ownership is transferred to the caller. Returns the node's
183 shash_steal(struct shash *sh, struct shash_node *node)
185 char *name = node->name;
187 hmap_remove(&sh->map, &node->node);
192 static struct shash_node *
193 shash_find__(const struct shash *sh, const char *name, size_t name_len,
196 struct shash_node *node;
198 HMAP_FOR_EACH_WITH_HASH (node, node, hash, &sh->map) {
199 if (!strncmp(node->name, name, name_len) && !node->name[name_len]) {
206 /* If there are duplicates, returns a random element. */
208 shash_find(const struct shash *sh, const char *name)
210 return shash_find__(sh, name, strlen(name), hash_name(name));
213 /* Finds and returns a shash_node within 'sh' that has the given 'name' that is
214 * exactly 'len' bytes long. Returns NULL if no node in 'sh' has that name. */
216 shash_find_len(const struct shash *sh, const char *name, size_t len)
218 return shash_find__(sh, name, len, hash_bytes(name, len, 0));
222 shash_find_data(const struct shash *sh, const char *name)
224 struct shash_node *node = shash_find(sh, name);
225 return node ? node->data : NULL;
229 shash_find_and_delete(struct shash *sh, const char *name)
231 struct shash_node *node = shash_find(sh, name);
233 void *data = node->data;
234 shash_delete(sh, node);
242 shash_find_and_delete_assert(struct shash *sh, const char *name)
244 void *data = shash_find_and_delete(sh, name);
245 assert(data != NULL);
250 shash_first(const struct shash *shash)
252 struct hmap_node *node = hmap_first(&shash->map);
253 return node ? CONTAINER_OF(node, struct shash_node, node) : NULL;
257 compare_nodes_by_name(const void *a_, const void *b_)
259 const struct shash_node *const *a = a_;
260 const struct shash_node *const *b = b_;
261 return strcmp((*a)->name, (*b)->name);
264 const struct shash_node **
265 shash_sort(const struct shash *sh)
267 if (shash_is_empty(sh)) {
270 const struct shash_node **nodes;
271 struct shash_node *node;
275 nodes = xmalloc(n * sizeof *nodes);
277 SHASH_FOR_EACH (node, sh) {
282 qsort(nodes, n, sizeof *nodes, compare_nodes_by_name);
288 /* Returns true if 'a' and 'b' contain the same keys (regardless of their
289 * values), false otherwise. */
291 shash_equal_keys(const struct shash *a, const struct shash *b)
293 struct shash_node *node;
295 if (hmap_count(&a->map) != hmap_count(&b->map)) {
298 SHASH_FOR_EACH (node, a) {
299 if (!shash_find(b, node->name)) {
306 /* Chooses and returns a randomly selected node from 'sh', which must not be
309 * I wouldn't depend on this algorithm to be fair, since I haven't analyzed it.
310 * But it does at least ensure that any node in 'sh' can be chosen. */
312 shash_random_node(struct shash *sh)
314 return CONTAINER_OF(hmap_random_node(&sh->map), struct shash_node, node);