| 1 | /* x-hash.c - basic hash tables |
| 2 | * |
| 3 | * Copyright (c) 2002-2012 Apple Inc. All rights reserved. |
| 4 | * |
| 5 | * Permission is hereby granted, free of charge, to any person |
| 6 | * obtaining a copy of this software and associated documentation files |
| 7 | * (the "Software"), to deal in the Software without restriction, |
| 8 | * including without limitation the rights to use, copy, modify, merge, |
| 9 | * publish, distribute, sublicense, and/or sell copies of the Software, |
| 10 | * and to permit persons to whom the Software is furnished to do so, |
| 11 | * subject to the following conditions: |
| 12 | * |
| 13 | * The above copyright notice and this permission notice shall be |
| 14 | * included in all copies or substantial portions of the Software. |
| 15 | * |
| 16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| 17 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| 18 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
| 19 | * NONINFRINGEMENT. IN NO EVENT SHALL THE ABOVE LISTED COPYRIGHT |
| 20 | * HOLDER(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, |
| 21 | * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 22 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
| 23 | * DEALINGS IN THE SOFTWARE. |
| 24 | * |
| 25 | * Except as contained in this notice, the name(s) of the above |
| 26 | * copyright holders shall not be used in advertising or otherwise to |
| 27 | * promote the sale, use or other dealings in this Software without |
| 28 | * prior written authorization. |
| 29 | */ |
| 30 | |
| 31 | #ifdef HAVE_DIX_CONFIG_H |
| 32 | #include <dix-config.h> |
| 33 | #endif |
| 34 | |
| 35 | #include "x-hash.h" |
| 36 | #include "x-list.h" |
| 37 | #include <stdlib.h> |
| 38 | #include <assert.h> |
| 39 | |
| 40 | struct x_hash_table_struct { |
| 41 | unsigned int bucket_index; |
| 42 | unsigned int total_keys; |
| 43 | x_list **buckets; |
| 44 | |
| 45 | x_hash_fun *hash_key; |
| 46 | x_compare_fun *compare_keys; |
| 47 | x_destroy_fun *destroy_key; |
| 48 | x_destroy_fun *destroy_value; |
| 49 | }; |
| 50 | |
| 51 | #define ITEM_NEW(k, v) X_PFX(list_prepend) ((x_list *)(k), v) |
| 52 | #define ITEM_FREE(i) X_PFX(list_free_1) (i) |
| 53 | #define ITEM_KEY(i) ((void *)(i)->next) |
| 54 | #define ITEM_VALUE(i) ((i)->data) |
| 55 | |
| 56 | #define SPLIT_THRESHOLD_FACTOR 2 |
| 57 | |
| 58 | /* http://planetmath.org/?op=getobj&from=objects&name=GoodHashTablePrimes */ |
| 59 | static const unsigned int bucket_sizes[] = { |
| 60 | 29, 53, 97, 193, 389, 769, 1543, |
| 61 | 3079, 6151, 12289, 24593, 49157, |
| 62 | 98317, 196613, 393241, 786433, 1572869, 3145739, 6291469, |
| 63 | 12582917, |
| 64 | 25165843, 50331653, 100663319, 201326611, 402653189, 805306457, |
| 65 | 1610612741 |
| 66 | }; |
| 67 | |
| 68 | #define N_BUCKET_SIZES (sizeof(bucket_sizes) / sizeof(bucket_sizes[0])) |
| 69 | |
| 70 | static inline unsigned int |
| 71 | hash_table_total_buckets(x_hash_table *h) |
| 72 | { |
| 73 | return bucket_sizes[h->bucket_index]; |
| 74 | } |
| 75 | |
| 76 | static inline void |
| 77 | hash_table_destroy_item(x_hash_table *h, void *k, void *v) |
| 78 | { |
| 79 | if (h->destroy_key != 0) |
| 80 | (*h->destroy_key)(k); |
| 81 | |
| 82 | if (h->destroy_value != 0) |
| 83 | (*h->destroy_value)(v); |
| 84 | } |
| 85 | |
| 86 | static inline size_t |
| 87 | hash_table_hash_key(x_hash_table *h, void *k) |
| 88 | { |
| 89 | if (h->hash_key != 0) |
| 90 | return (*h->hash_key)(k); |
| 91 | else |
| 92 | return (size_t)k; |
| 93 | } |
| 94 | |
| 95 | static inline int |
| 96 | hash_table_compare_keys(x_hash_table *h, void *k1, void *k2) |
| 97 | { |
| 98 | if (h->compare_keys == 0) |
| 99 | return k1 == k2; |
| 100 | else |
| 101 | return (*h->compare_keys)(k1, k2) == 0; |
| 102 | } |
| 103 | |
| 104 | static void |
| 105 | hash_table_split(x_hash_table *h) |
| 106 | { |
| 107 | x_list **new, **old; |
| 108 | x_list *node, *item, *next; |
| 109 | int new_size, old_size; |
| 110 | size_t b; |
| 111 | int i; |
| 112 | |
| 113 | if (h->bucket_index == N_BUCKET_SIZES - 1) |
| 114 | return; |
| 115 | |
| 116 | old_size = hash_table_total_buckets(h); |
| 117 | old = h->buckets; |
| 118 | |
| 119 | h->bucket_index++; |
| 120 | |
| 121 | new_size = hash_table_total_buckets(h); |
| 122 | new = calloc(new_size, sizeof(x_list *)); |
| 123 | |
| 124 | if (new == 0) { |
| 125 | h->bucket_index--; |
| 126 | return; |
| 127 | } |
| 128 | |
| 129 | for (i = 0; i < old_size; i++) { |
| 130 | for (node = old[i]; node != 0; node = next) { |
| 131 | next = node->next; |
| 132 | item = node->data; |
| 133 | |
| 134 | b = hash_table_hash_key(h, ITEM_KEY(item)) % new_size; |
| 135 | |
| 136 | node->next = new[b]; |
| 137 | new[b] = node; |
| 138 | } |
| 139 | } |
| 140 | |
| 141 | h->buckets = new; |
| 142 | free(old); |
| 143 | } |
| 144 | |
| 145 | X_EXTERN x_hash_table * |
| 146 | X_PFX(hash_table_new) (x_hash_fun * hash, |
| 147 | x_compare_fun * compare, |
| 148 | x_destroy_fun * key_destroy, |
| 149 | x_destroy_fun * value_destroy) { |
| 150 | x_hash_table *h; |
| 151 | |
| 152 | h = calloc(1, sizeof(x_hash_table)); |
| 153 | if (h == 0) |
| 154 | return 0; |
| 155 | |
| 156 | h->bucket_index = 0; |
| 157 | h->buckets = calloc(hash_table_total_buckets(h), sizeof(x_list *)); |
| 158 | |
| 159 | if (h->buckets == 0) { |
| 160 | free(h); |
| 161 | return 0; |
| 162 | } |
| 163 | |
| 164 | h->hash_key = hash; |
| 165 | h->compare_keys = compare; |
| 166 | h->destroy_key = key_destroy; |
| 167 | h->destroy_value = value_destroy; |
| 168 | |
| 169 | return h; |
| 170 | } |
| 171 | |
| 172 | X_EXTERN void |
| 173 | X_PFX(hash_table_free) (x_hash_table * h) { |
| 174 | int n, i; |
| 175 | x_list *node, *item; |
| 176 | |
| 177 | assert(h != NULL); |
| 178 | |
| 179 | n = hash_table_total_buckets(h); |
| 180 | |
| 181 | for (i = 0; i < n; i++) { |
| 182 | for (node = h->buckets[i]; node != 0; node = node->next) { |
| 183 | item = node->data; |
| 184 | hash_table_destroy_item(h, ITEM_KEY(item), ITEM_VALUE(item)); |
| 185 | ITEM_FREE(item); |
| 186 | } |
| 187 | X_PFX(list_free) (h->buckets[i]); |
| 188 | } |
| 189 | |
| 190 | free(h->buckets); |
| 191 | free(h); |
| 192 | } |
| 193 | |
| 194 | X_EXTERN unsigned int |
| 195 | X_PFX(hash_table_size) (x_hash_table * h) { |
| 196 | assert(h != NULL); |
| 197 | |
| 198 | return h->total_keys; |
| 199 | } |
| 200 | |
| 201 | static void |
| 202 | hash_table_modify(x_hash_table *h, void *k, void *v, int replace) |
| 203 | { |
| 204 | size_t hash_value; |
| 205 | x_list *node, *item; |
| 206 | |
| 207 | assert(h != NULL); |
| 208 | |
| 209 | hash_value = hash_table_hash_key(h, k); |
| 210 | |
| 211 | for (node = h->buckets[hash_value % hash_table_total_buckets(h)]; |
| 212 | node != 0; node = node->next) { |
| 213 | item = node->data; |
| 214 | |
| 215 | if (hash_table_compare_keys(h, ITEM_KEY(item), k)) { |
| 216 | if (replace) { |
| 217 | hash_table_destroy_item(h, ITEM_KEY(item), |
| 218 | ITEM_VALUE(item)); |
| 219 | item->next = k; |
| 220 | ITEM_VALUE(item) = v; |
| 221 | } |
| 222 | else { |
| 223 | hash_table_destroy_item(h, k, ITEM_VALUE(item)); |
| 224 | ITEM_VALUE(item) = v; |
| 225 | } |
| 226 | return; |
| 227 | } |
| 228 | } |
| 229 | |
| 230 | /* Key isn't already in the table. Insert it. */ |
| 231 | |
| 232 | if (h->total_keys + 1 |
| 233 | > hash_table_total_buckets(h) * SPLIT_THRESHOLD_FACTOR) { |
| 234 | hash_table_split(h); |
| 235 | } |
| 236 | |
| 237 | hash_value = hash_value % hash_table_total_buckets(h); |
| 238 | h->buckets[hash_value] = X_PFX(list_prepend) (h->buckets[hash_value], |
| 239 | ITEM_NEW(k, v)); |
| 240 | h->total_keys++; |
| 241 | } |
| 242 | |
| 243 | X_EXTERN void |
| 244 | X_PFX(hash_table_insert) (x_hash_table * h, void *k, void *v) { |
| 245 | hash_table_modify(h, k, v, 0); |
| 246 | } |
| 247 | |
| 248 | X_EXTERN void |
| 249 | X_PFX(hash_table_replace) (x_hash_table * h, void *k, void *v) { |
| 250 | hash_table_modify(h, k, v, 1); |
| 251 | } |
| 252 | |
| 253 | X_EXTERN void |
| 254 | X_PFX(hash_table_remove) (x_hash_table * h, void *k) { |
| 255 | size_t hash_value; |
| 256 | x_list **ptr, *item; |
| 257 | |
| 258 | assert(h != NULL); |
| 259 | |
| 260 | hash_value = hash_table_hash_key(h, k); |
| 261 | |
| 262 | for (ptr = &h->buckets[hash_value % hash_table_total_buckets(h)]; |
| 263 | *ptr != 0; ptr = &((*ptr)->next)) { |
| 264 | item = (*ptr)->data; |
| 265 | |
| 266 | if (hash_table_compare_keys(h, ITEM_KEY(item), k)) { |
| 267 | hash_table_destroy_item(h, ITEM_KEY(item), ITEM_VALUE(item)); |
| 268 | ITEM_FREE(item); |
| 269 | item = *ptr; |
| 270 | *ptr = item->next; |
| 271 | X_PFX(list_free_1) (item); |
| 272 | h->total_keys--; |
| 273 | return; |
| 274 | } |
| 275 | } |
| 276 | } |
| 277 | |
| 278 | X_EXTERN void * |
| 279 | X_PFX(hash_table_lookup) (x_hash_table * h, void *k, void **k_ret) { |
| 280 | size_t hash_value; |
| 281 | x_list *node, *item; |
| 282 | |
| 283 | assert(h != NULL); |
| 284 | |
| 285 | hash_value = hash_table_hash_key(h, k); |
| 286 | |
| 287 | for (node = h->buckets[hash_value % hash_table_total_buckets(h)]; |
| 288 | node != 0; node = node->next) { |
| 289 | item = node->data; |
| 290 | |
| 291 | if (hash_table_compare_keys(h, ITEM_KEY(item), k)) { |
| 292 | if (k_ret != 0) |
| 293 | *k_ret = ITEM_KEY(item); |
| 294 | |
| 295 | return ITEM_VALUE(item); |
| 296 | } |
| 297 | } |
| 298 | |
| 299 | if (k_ret != 0) |
| 300 | *k_ret = 0; |
| 301 | |
| 302 | return 0; |
| 303 | } |
| 304 | |
| 305 | X_EXTERN void |
| 306 | X_PFX(hash_table_foreach) (x_hash_table * h, |
| 307 | x_hash_foreach_fun * fun, void *data) { |
| 308 | int i, n; |
| 309 | x_list *node, *item; |
| 310 | |
| 311 | assert(h != NULL); |
| 312 | |
| 313 | n = hash_table_total_buckets(h); |
| 314 | |
| 315 | for (i = 0; i < n; i++) { |
| 316 | for (node = h->buckets[i]; node != 0; node = node->next) { |
| 317 | item = node->data; |
| 318 | (*fun)(ITEM_KEY(item), ITEM_VALUE(item), data); |
| 319 | } |
| 320 | } |
| 321 | } |