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_delete(struct shash *sh, struct shash_node *node)
 104 {
 105     hmap_remove(&sh->map, &node->node);
 106     free(node->name);
 107     free(node);
 108 }
 109
 110 /* If there are duplicates, returns a random element. */
 111 struct shash_node *
 112 shash_find(const struct shash *sh, const char *name)
 113 {
 114     struct shash_node *node;
 115
 116     HMAP_FOR_EACH_WITH_HASH (node, struct shash_node, node,
 117                              hash_name(name), &sh->map) {
 118         if (!strcmp(node->name, name)) {
 119             return node;
 120         }
 121     }
 122     return NULL;
 123 }
 124
 125 void *
 126 shash_find_data(const struct shash *sh, const char *name)
 127 {
 128     struct shash_node *node = shash_find(sh, name);
 129     return node ? node->data : NULL;
 130 }
 131
 132 void *
 133 shash_find_and_delete(struct shash *sh, const char *name)
 134 {
 135     struct shash_node *node = shash_find(sh, name);
 136     if (node) {
 137         void *data = node->data;
 138         shash_delete(sh, node);
 139         return data;
 140     } else {
 141         return NULL;
 142     }
 143 }
 144
 145 struct shash_node *
 146 shash_first(const struct shash *shash)
 147 {
 148     struct hmap_node *node = hmap_first(&shash->map);
 149     return node ? CONTAINER_OF(node, struct shash_node, node) : NULL;
 150 }
 151
 152 static int
 153 compare_nodes_by_name(const void *a_, const void *b_)
 154 {
 155     const struct shash_node *const *a = a_;
 156     const struct shash_node *const *b = b_;
 157     return strcmp((*a)->name, (*b)->name);
 158 }
 159
 160 const struct shash_node **
 161 shash_sort(const struct shash *sh)
 162 {
 163     if (shash_is_empty(sh)) {
 164         return NULL;
 165     } else {
 166         const struct shash_node **nodes;
 167         struct shash_node *node;
 168         size_t i, n;
 169
 170         n = shash_count(sh);
 171         nodes = xmalloc(n * sizeof *nodes);
 172         i = 0;
 173         SHASH_FOR_EACH (node, sh) {
 174             nodes[i++] = node;
 175         }
 176         assert(i == n);
 177
 178         qsort(nodes, n, sizeof *nodes, compare_nodes_by_name);
 179
 180         return nodes;
 181     }
 182 }
 183
 184 /* Returns true if 'a' and 'b' contain the same keys (regardless of their
 185  * values), false otherwise. */
 186 bool
 187 shash_equal_keys(const struct shash *a, const struct shash *b)
 188 {
 189     struct shash_node *node;
 190
 191     if (hmap_count(&a->map) != hmap_count(&b->map)) {
 192         return false;
 193     }
 194     SHASH_FOR_EACH (node, a) {
 195         if (!shash_find(b, node->name)) {
 196             return false;
 197         }
 198     }
 199     return true;
 200 }