lib/shash.c

   1 /*
   2  * Copyright (c) 2009, 2010 Nicira Networks.
   3  *
   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:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  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.
  15  */
  16
  17 #include <config.h>
  18 #include "shash.h"
  19 #include <assert.h>
  20 #include "hash.h"
  21
  22 static size_t
  23 hash_name(const char *name)
  24 {
  25     return hash_string(name, 0);
  26 }
  27
  28 void
  29 shash_init(struct shash *sh)
  30 {
  31     hmap_init(&sh->map);
  32 }
  33
  34 void
  35 shash_destroy(struct shash *sh)
  36 {
  37     if (sh) {
  38         shash_clear(sh);
  39         hmap_destroy(&sh->map);
  40     }
  41 }
  42
  43 void
  44 shash_swap(struct shash *a, struct shash *b)
  45 {
  46     hmap_swap(&a->map, &b->map);
  47 }
  48
  49 void
  50 shash_moved(struct shash *sh)
  51 {
  52     hmap_moved(&sh->map);
  53 }
  54
  55 void
  56 shash_clear(struct shash *sh)
  57 {
  58     struct shash_node *node, *next;
  59
  60     SHASH_FOR_EACH_SAFE (node, next, sh) {
  61         hmap_remove(&sh->map, &node->node);
  62         free(node->name);
  63         free(node);
  64     }
  65 }
  66
  67 bool
  68 shash_is_empty(const struct shash *shash)
  69 {
  70     return hmap_is_empty(&shash->map);
  71 }
  72
  73 size_t
  74 shash_count(const struct shash *shash)
  75 {
  76     return hmap_count(&shash->map);
  77 }
  78
  79 /* It is the caller's responsibility to avoid duplicate names, if that is
  80  * desirable. */
  81 struct shash_node *
  82 shash_add(struct shash *sh, const char *name, const void *data)
  83 {
  84     struct shash_node *node = xmalloc(sizeof *node);
  85     node->name = xstrdup(name);
  86     node->data = (void *) data;
  87     hmap_insert(&sh->map, &node->node, hash_name(name));
  88     return node;
  89 }
  90
  91 bool
  92 shash_add_once(struct shash *sh, const char *name, const void *data)
  93 {
  94     if (!shash_find(sh, name)) {
  95         shash_add(sh, name, data);
  96         return true;
  97     } else {
  98         return false;
  99     }
 100 }
 101
 102 void
 103 shash_add_assert(struct shash *sh, const char *name, const void *data)
 104 {
 105     bool added OVS_UNUSED = shash_add_once(sh, name, data);
 106     assert(added);
 107 }
 108
 109 void
 110 shash_delete(struct shash *sh, struct shash_node *node)
 111 {
 112     hmap_remove(&sh->map, &node->node);
 113     free(node->name);
 114     free(node);
 115 }
 116
 117 /* If there are duplicates, returns a random element. */
 118 struct shash_node *
 119 shash_find(const struct shash *sh, const char *name)
 120 {
 121     struct shash_node *node;
 122
 123     HMAP_FOR_EACH_WITH_HASH (node, struct shash_node, node,
 124                              hash_name(name), &sh->map) {
 125         if (!strcmp(node->name, name)) {
 126             return node;
 127         }
 128     }
 129     return NULL;
 130 }
 131
 132 void *
 133 shash_find_data(const struct shash *sh, const char *name)
 134 {
 135     struct shash_node *node = shash_find(sh, name);
 136     return node ? node->data : NULL;
 137 }
 138
 139 void *
 140 shash_find_and_delete(struct shash *sh, const char *name)
 141 {
 142     struct shash_node *node = shash_find(sh, name);
 143     if (node) {
 144         void *data = node->data;
 145         shash_delete(sh, node);
 146         return data;
 147     } else {
 148         return NULL;
 149     }
 150 }
 151
 152 void *
 153 shash_find_and_delete_assert(struct shash *sh, const char *name)
 154 {
 155     void *data = shash_find_and_delete(sh, name);
 156     assert(data != NULL);
 157     return data;
 158 }
 159
 160 struct shash_node *
 161 shash_first(const struct shash *shash)
 162 {
 163     struct hmap_node *node = hmap_first(&shash->map);
 164     return node ? CONTAINER_OF(node, struct shash_node, node) : NULL;
 165 }
 166
 167 static int
 168 compare_nodes_by_name(const void *a_, const void *b_)
 169 {
 170     const struct shash_node *const *a = a_;
 171     const struct shash_node *const *b = b_;
 172     return strcmp((*a)->name, (*b)->name);
 173 }
 174
 175 const struct shash_node **
 176 shash_sort(const struct shash *sh)
 177 {
 178     if (shash_is_empty(sh)) {
 179         return NULL;
 180     } else {
 181         const struct shash_node **nodes;
 182         struct shash_node *node;
 183         size_t i, n;
 184
 185         n = shash_count(sh);
 186         nodes = xmalloc(n * sizeof *nodes);
 187         i = 0;
 188         SHASH_FOR_EACH (node, sh) {
 189             nodes[i++] = node;
 190         }
 191         assert(i == n);
 192
 193         qsort(nodes, n, sizeof *nodes, compare_nodes_by_name);
 194
 195         return nodes;
 196     }
 197 }
 198
 199 /* Returns true if 'a' and 'b' contain the same keys (regardless of their
 200  * values), false otherwise. */
 201 bool
 202 shash_equal_keys(const struct shash *a, const struct shash *b)
 203 {
 204     struct shash_node *node;
 205
 206     if (hmap_count(&a->map) != hmap_count(&b->map)) {
 207         return false;
 208     }
 209     SHASH_FOR_EACH (node, a) {
 210         if (!shash_find(b, node->name)) {
 211             return false;
 212         }
 213     }
 214     return true;
 215 }