ucx/map.h

Thu, 15 Oct 2015 14:21:38 +0200

author
Mike Becker <universe@uap-core.de>
date
Thu, 15 Oct 2015 14:21:38 +0200
changeset 208
262c7be94eba
parent 206
58b77eb51afd
child 209
4f02199d8aae
permissions
-rw-r--r--

added convenience function ucx_map_free_contents()

olaf@2 1 /*
universe@103 2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
universe@103 3 *
universe@192 4 * Copyright 2015 Olaf Wintermann. All rights reserved.
universe@103 5 *
universe@103 6 * Redistribution and use in source and binary forms, with or without
universe@103 7 * modification, are permitted provided that the following conditions are met:
universe@103 8 *
universe@103 9 * 1. Redistributions of source code must retain the above copyright
universe@103 10 * notice, this list of conditions and the following disclaimer.
universe@103 11 *
universe@103 12 * 2. Redistributions in binary form must reproduce the above copyright
universe@103 13 * notice, this list of conditions and the following disclaimer in the
universe@103 14 * documentation and/or other materials provided with the distribution.
universe@103 15 *
universe@103 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
universe@103 17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
universe@103 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
universe@103 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
universe@103 20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
universe@103 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
universe@103 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
universe@103 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
universe@103 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
universe@103 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
universe@103 26 * POSSIBILITY OF SUCH DAMAGE.
olaf@2 27 */
olaf@2 28
universe@136 29 /**
universe@136 30 * @file map.h
universe@136 31 *
universe@136 32 * Hash map implementation.
universe@136 33 *
universe@136 34 * This implementation uses murmur hash 2 and separate chaining with linked
universe@136 35 * lists.
universe@136 36 *
universe@136 37 * @author Mike Becker
universe@136 38 * @author Olaf Wintermann
universe@136 39 */
universe@136 40
olaf@120 41 #ifndef UCX_MAP_H
olaf@120 42 #define UCX_MAP_H
olaf@2 43
olaf@20 44 #include "ucx.h"
olaf@20 45 #include "string.h"
universe@114 46 #include "allocator.h"
universe@41 47 #include <stdio.h>
olaf@20 48
olaf@2 49 #ifdef __cplusplus
olaf@2 50 extern "C" {
olaf@2 51 #endif
olaf@2 52
universe@138 53 /**
universe@138 54 * Loop statement for UCX maps.
universe@138 55 *
universe@138 56 * The <code>key</code> variable is implicitly defined, but the
universe@138 57 * <code>value</code> variable must be already declared as type information
universe@138 58 * cannot be inferred.
universe@138 59 *
universe@138 60 * @param key the variable name for the key
universe@138 61 * @param value the variable name for the value
universe@138 62 * @param iter an UcxMapIterator
universe@138 63 * @see ucx_map_iterator()
universe@138 64 */
universe@138 65 #define UCX_MAP_FOREACH(key,value,iter) \
universe@138 66 for(UcxKey key;ucx_map_iter_next(&iter,&key, (void**)&value);)
olaf@31 67
universe@138 68 /** Type for the UCX map. @see UcxMap */
olaf@31 69 typedef struct UcxMap UcxMap;
universe@146 70
universe@138 71 /** Type for a key of an UcxMap. @see UcxKey */
olaf@31 72 typedef struct UcxKey UcxKey;
universe@146 73
universe@138 74 /** Type for an element of an UcxMap. @see UcxMapElement */
olaf@31 75 typedef struct UcxMapElement UcxMapElement;
universe@146 76
universe@138 77 /** Type for an iterator over an UcxMap. @see UcxMapIterator */
olaf@31 78 typedef struct UcxMapIterator UcxMapIterator;
olaf@2 79
universe@138 80 /** Structure for the UCX map. */
olaf@20 81 struct UcxMap {
universe@138 82 /** An allocator that is used for the map elements. */
olaf@107 83 UcxAllocator *allocator;
universe@138 84 /** The array of map element lists. */
universe@29 85 UcxMapElement **map;
universe@138 86 /** The size of the map is the length of the element list array. */
olaf@20 87 size_t size;
universe@138 88 /** The count of elements currently stored in this map. */
olaf@45 89 size_t count;
olaf@20 90 };
olaf@2 91
universe@138 92 /** Structure for a key of an UcxMap. */
olaf@20 93 struct UcxKey {
universe@138 94 /** The key data. */
olaf@20 95 void *data;
universe@138 96 /** The length of the key data. */
olaf@20 97 size_t len;
universe@138 98 /** The hash value of the key data. */
olaf@20 99 int hash;
olaf@20 100 };
olaf@20 101
universe@138 102 /** Structure for an element of an UcxMap. */
olaf@20 103 struct UcxMapElement {
universe@138 104 /** The value data. */
olaf@20 105 void *data;
universe@146 106
universe@138 107 /** A pointer to the next element in the current list. */
olaf@20 108 UcxMapElement *next;
universe@146 109
universe@138 110 /** The corresponding key. */
olaf@20 111 UcxKey key;
olaf@20 112 };
olaf@20 113
universe@138 114 /** Structure for an iterator over an UcxMap. */
olaf@31 115 struct UcxMapIterator {
universe@138 116 /** The map to iterate over. */
olaf@31 117 UcxMap *map;
universe@146 118
universe@138 119 /** The current map element. */
olaf@31 120 UcxMapElement *cur;
universe@146 121
universe@138 122 /**
universe@138 123 * The current index of the element list array.
universe@138 124 * <b>Attention: </b> this is <b>NOT</b> the element index! Do <b>NOT</b>
universe@138 125 * manually iterate over the map by increasing this index. Use
universe@138 126 * ucx_map_iter_next().
universe@138 127 * @see UcxMap.map*/
universe@95 128 size_t index;
olaf@31 129 };
olaf@31 130
universe@136 131 /**
universe@136 132 * Creates a new hash map with the specified size.
universe@136 133 * @param size the size of the hash map
universe@136 134 * @return a pointer to the new hash map
universe@136 135 */
universe@136 136 UcxMap *ucx_map_new(size_t size);
olaf@20 137
universe@136 138 /**
universe@136 139 * Creates a new hash map with the specified size using an UcxAllocator.
olaf@137 140 * @param allocator the allocator to use
universe@136 141 * @param size the size of the hash map
universe@136 142 * @return a pointer to the new hash map
universe@136 143 */
olaf@137 144 UcxMap *ucx_map_new_a(UcxAllocator *allocator, size_t size);
universe@136 145
universe@136 146 /**
universe@136 147 * Frees a hash map.
universe@136 148 *
universe@208 149 * <b>Note:</b> the contents are <b>not</b> freed, use ucx_map_free_content()
universe@208 150 * before calling this function to achieve that.
universe@136 151 *
universe@136 152 * @param map the map to be freed
universe@208 153 * @see ucx_map_free_content()
universe@136 154 */
universe@29 155 void ucx_map_free(UcxMap *map);
universe@136 156
universe@138 157 /**
universe@208 158 * Frees the contents of a hash map.
universe@208 159 *
universe@208 160 * This is a convenience function that iterates over the map and passes all
universe@208 161 * values to the standard library free() function.
universe@208 162 *
universe@208 163 * You must ensure, that it is valid to pass each value in the map to free().
universe@208 164 *
universe@208 165 * You should free or clear the map afterwards, as the contents will be invalid.
universe@208 166 *
universe@208 167 * @param map for which the contents shall be freed
universe@208 168 * @see ucx_map_free()
universe@208 169 * @see ucx_map_clear()
universe@208 170 */
universe@208 171 void ucx_map_free_content(UcxMap *map);
universe@208 172
universe@208 173 /**
universe@206 174 * Clears a hash map.
universe@206 175 *
universe@208 176 * <b>Note:</b> the contents are <b>not</b> freed, use ucx_map_free_content()
universe@208 177 * before calling this function to achieve that.
universe@206 178 *
universe@208 179 * @param map the map to be cleared
universe@208 180 * @see ucx_map_free_content()
universe@206 181 */
universe@206 182 void ucx_map_clear(UcxMap *map);
universe@206 183
universe@208 184
universe@206 185 /**
universe@138 186 * Copies contents from a map to another map using a copy function.
universe@138 187 *
universe@138 188 * <b>Note:</b> The destination map does not need to be empty. However, if it
universe@138 189 * contains data with keys that are also present in the source map, the contents
universe@138 190 * are overwritten.
universe@138 191 *
universe@138 192 * @param from the source map
universe@138 193 * @param to the destination map
universe@138 194 * @param fnc the copy function or <code>NULL</code> if the pointer address
universe@138 195 * shall be copied
universe@138 196 * @param data additional data for the copy function
universe@138 197 * @return 0 on success or a non-zero value on memory allocation errors
universe@138 198 */
universe@67 199 int ucx_map_copy(UcxMap *restrict from, UcxMap *restrict to,
universe@67 200 copy_func fnc, void *data);
universe@138 201
universe@138 202 /**
universe@138 203 * Clones the map and rehashes if necessary.
universe@138 204 *
universe@138 205 * <b>Note:</b> In contrast to ucx_map_rehash() the load factor is irrelevant.
universe@138 206 * This function <i>always</i> ensures a new UcxMap.size of at least
universe@138 207 * 2.5*UcxMap.count.
universe@138 208 *
universe@138 209 * @param map the map to clone
universe@138 210 * @param fnc the copy function to use or <code>NULL</code> if the new and
universe@138 211 * the old map shall share the data pointers
universe@138 212 * @param data additional data for the copy function
universe@138 213 * @return the cloned map
universe@138 214 * @see ucx_map_copy()
universe@138 215 */
olaf@44 216 UcxMap *ucx_map_clone(UcxMap *map, copy_func fnc, void *data);
universe@138 217
universe@138 218 /**
universe@138 219 * Increases size of the hash map, if necessary.
universe@138 220 *
universe@138 221 * The load value is 0.75*UcxMap.size. If the element count exceeds the load
universe@138 222 * value, the map needs to be rehashed. Otherwise no action is performed and
universe@138 223 * this function simply returns 0.
universe@138 224 *
universe@138 225 * The rehashing process ensures, that the UcxMap.size is at least
universe@138 226 * 2.5*UcxMap.count. So there is enough room for additional elements without
universe@138 227 * the need of another soon rehashing.
universe@138 228 *
universe@138 229 * You can use this function to dramatically increase access performance.
universe@138 230 *
universe@138 231 * @param map the map to rehash
universe@138 232 * @return 1, if a memory allocation error occurred, 0 otherwise
universe@138 233 */
olaf@52 234 int ucx_map_rehash(UcxMap *map);
olaf@20 235
universe@138 236 /**
universe@138 237 * Puts a key/value-pair into the map.
universe@138 238 *
universe@138 239 * @param map the map
universe@138 240 * @param key the key
universe@138 241 * @param value the value
universe@138 242 * @return 0 on success, non-zero value on failure
universe@138 243 */
universe@138 244 int ucx_map_put(UcxMap *map, UcxKey key, void *value);
universe@138 245
universe@138 246 /**
universe@138 247 * Retrieves a value by using a key.
universe@138 248 *
universe@138 249 * @param map the map
universe@138 250 * @param key the key
universe@138 251 * @return the value
universe@138 252 */
olaf@20 253 void* ucx_map_get(UcxMap *map, UcxKey key);
universe@138 254
universe@138 255 /**
universe@138 256 * Removes a key/value-pair from the map by using the key.
universe@138 257 *
universe@138 258 * @param map the map
universe@138 259 * @param key the key
universe@138 260 * @return the removed value
universe@138 261 */
universe@53 262 void* ucx_map_remove(UcxMap *map, UcxKey key);
olaf@20 263
universe@136 264 /**
universe@136 265 * Shorthand for putting data with a sstr_t key into the map.
universe@136 266 * @param map the map
universe@136 267 * @param key the key
universe@136 268 * @param value the value
universe@138 269 * @return 0 on success, non-zero value on failure
universe@136 270 * @see ucx_map_put()
universe@136 271 */
universe@136 272 #define ucx_map_sstr_put(map, key, value) \
universe@136 273 ucx_map_put(map, ucx_key(key.ptr, key.length), (void*)value)
universe@146 274
universe@136 275 /**
universe@136 276 * Shorthand for putting data with a C string key into the map.
universe@136 277 * @param map the map
universe@136 278 * @param key the key
universe@136 279 * @param value the value
universe@138 280 * @return 0 on success, non-zero value on failure
universe@136 281 * @see ucx_map_put()
universe@136 282 */
universe@136 283 #define ucx_map_cstr_put(map, key, value) \
universe@136 284 ucx_map_put(map, ucx_key((void*)key, strlen(key)), (void*)value)
universe@146 285
universe@136 286 /**
universe@136 287 * Shorthand for putting data with an integer key into the map.
universe@136 288 * @param map the map
universe@136 289 * @param key the key
universe@136 290 * @param value the value
universe@138 291 * @return 0 on success, non-zero value on failure
universe@136 292 * @see ucx_map_put()
universe@136 293 */
universe@136 294 #define ucx_map_int_put(map, key, value) \
universe@136 295 ucx_map_put(map, ucx_key((void*)&key, sizeof(key)), (void*)value)
olaf@78 296
universe@136 297 /**
universe@136 298 * Shorthand for getting data from the map with a sstr_t key.
universe@136 299 * @param map the map
universe@136 300 * @param key the key
universe@138 301 * @return the value
universe@136 302 * @see ucx_map_get()
universe@136 303 */
universe@136 304 #define ucx_map_sstr_get(map, key) \
universe@136 305 ucx_map_get(map, ucx_key(key.ptr, key.length))
universe@146 306
universe@136 307 /**
universe@136 308 * Shorthand for getting data from the map with a C string key.
universe@138 309 * @param map the map
universe@138 310 * @param key the key
universe@138 311 * @return the value
universe@136 312 * @see ucx_map_get()
universe@136 313 */
universe@136 314 #define ucx_map_cstr_get(map, key) \
universe@136 315 ucx_map_get(map, ucx_key((void*)key, strlen(key)))
universe@146 316
universe@136 317 /**
universe@136 318 * Shorthand for getting data from the map with an integer key.
universe@136 319 * @param map the map
universe@136 320 * @param key the key
universe@138 321 * @return the value
universe@136 322 * @see ucx_map_get()
universe@136 323 */
universe@136 324 #define ucx_map_int_get(map, key) \
universe@136 325 ucx_map_get(map, ucx_key((void*)&key, sizeof(int)))
universe@146 326
universe@136 327 /**
universe@136 328 * Shorthand for removing data from the map with a sstr_t key.
universe@136 329 * @param map the map
universe@136 330 * @param key the key
universe@138 331 * @return the removed value
universe@136 332 * @see ucx_map_remove()
universe@136 333 */
universe@136 334 #define ucx_map_sstr_remove(map, key) \
universe@136 335 ucx_map_remove(map, ucx_key(key.ptr, key.length))
universe@146 336
universe@136 337 /**
universe@136 338 * Shorthand for removing data from the map with a C string key.
universe@136 339 * @param map the map
universe@136 340 * @param key the key
universe@138 341 * @return the removed value
universe@136 342 * @see ucx_map_remove()
universe@136 343 */
universe@136 344 #define ucx_map_cstr_remove(map, key) \
universe@136 345 ucx_map_remove(map, ucx_key((void*)key, strlen(key)))
universe@146 346
universe@136 347 /**
universe@136 348 * Shorthand for removing data from the map with an integer key.
universe@136 349 * @param map the map
universe@136 350 * @param key the key
universe@138 351 * @return the removed value
universe@136 352 * @see ucx_map_remove()
universe@136 353 */
universe@136 354 #define ucx_map_int_remove(map, key) \
universe@136 355 ucx_map_remove(map, ucx_key((void*)&key, sizeof(key)))
olaf@20 356
universe@138 357 /**
universe@138 358 * Creates an UcxKey based on the given data.
universe@138 359 *
universe@138 360 * This function implicitly computes the hash.
universe@138 361 *
universe@138 362 * @param data the data for the key
universe@138 363 * @param len the length of the data
universe@138 364 * @return an UcxKey with implicitly computed hash
universe@138 365 * @see ucx_hash()
universe@138 366 */
olaf@20 367 UcxKey ucx_key(void *data, size_t len);
olaf@20 368
universe@138 369 /**
universe@138 370 * Computes a murmur hash-2.
universe@138 371 *
universe@138 372 * @param data the data to hash
universe@138 373 * @param len the length of the data
universe@138 374 * @return the murmur hash-2 of the data
universe@138 375 */
universe@67 376 int ucx_hash(const char *data, size_t len);
olaf@2 377
universe@138 378 /**
universe@138 379 * Creates an iterator for a map.
universe@138 380 *
universe@138 381 * <b>Note:</b> An UcxMapIterator iterates over all elements in all element
universe@138 382 * lists successively. Therefore the order highly depends on the key hashes and
universe@138 383 * may vary under different map sizes. So generally you may <b>NOT</b> rely on
universe@138 384 * the iteration order.
universe@138 385 *
universe@138 386 * <b>Note:</b> The iterator is <b>NOT</b> initialized. You need to call
universe@138 387 * ucx_map_iter_next() at least once before accessing any information. However,
universe@138 388 * it is not recommended to access the fields of an UcxMapIterator directly.
universe@138 389 *
universe@138 390 * @param map the map to create the iterator for
universe@138 391 * @return an iterator initialized on the first element of the
universe@138 392 * first element list
universe@138 393 * @see ucx_map_iter_next()
universe@138 394 */
olaf@31 395 UcxMapIterator ucx_map_iterator(UcxMap *map);
olaf@31 396
universe@138 397 /**
universe@138 398 * Proceeds to the next element of the map (if any).
universe@138 399 *
universe@138 400 * Subsequent calls on the same iterator proceed to the next element and
universe@138 401 * store the key/value-pair into the memory specified as arguments of this
universe@138 402 * function.
universe@138 403 *
universe@138 404 * If no further elements are found, this function returns zero and leaves the
universe@138 405 * last found key/value-pair in memory.
universe@138 406 *
universe@138 407 * @param iterator the iterator to use
universe@138 408 * @param key a pointer to the memory where to store the key
universe@138 409 * @param value a pointer to the memory where to store the value
universe@138 410 * @return 1, if another element was found, 0 if all elements has been processed
universe@138 411 * @see ucx_map_iterator()
universe@138 412 */
universe@138 413 int ucx_map_iter_next(UcxMapIterator *iterator, UcxKey *key, void **value);
olaf@31 414
universe@42 415
olaf@2 416 #ifdef __cplusplus
olaf@2 417 }
olaf@2 418 #endif
olaf@2 419
olaf@120 420 #endif /* UCX_MAP_H */
olaf@2 421

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