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comparison: src/ucx/map.h

src/ucx/map.h

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1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
3 *
4 * Copyright 2017 Mike Becker, Olaf Wintermann All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 /**
30 * @file map.h
31 *
32 * Hash map implementation.
33 *
34 * This implementation uses murmur hash 2 and separate chaining with linked
35 * lists.
36 *
37 * @author Mike Becker
38 * @author Olaf Wintermann
39 */
40
41 #ifndef UCX_MAP_H
42 #define UCX_MAP_H
43
44 #include "ucx.h"
45 #include "string.h"
46 #include "allocator.h"
47 #include <stdio.h>
48
49 #ifdef __cplusplus
50 extern "C" {
51 #endif
52
53 /**
54 * Loop statement for UCX maps.
55 *
56 * The <code>key</code> variable is implicitly defined, but the
57 * <code>value</code> variable must be already declared as type information
58 * cannot be inferred.
59 *
60 * @param key the variable name for the key
61 * @param value the variable name for the value
62 * @param iter a UcxMapIterator
63 * @see ucx_map_iterator()
64 */
65 #define UCX_MAP_FOREACH(key,value,iter) \
66 for(UcxKey key;ucx_map_iter_next(&iter,&key, (void**)&value);)
67
68 /** Type for the UCX map. @see UcxMap */
69 typedef struct UcxMap UcxMap;
70
71 /** Type for a key of a UcxMap. @see UcxKey */
72 typedef struct UcxKey UcxKey;
73
74 /** Type for an element of a UcxMap. @see UcxMapElement */
75 typedef struct UcxMapElement UcxMapElement;
76
77 /** Type for an iterator over a UcxMap. @see UcxMapIterator */
78 typedef struct UcxMapIterator UcxMapIterator;
79
80 /** Structure for the UCX map. */
81 struct UcxMap {
82 /** An allocator that is used for the map elements. */
83 UcxAllocator *allocator;
84 /** The array of map element lists. */
85 UcxMapElement **map;
86 /** The size of the map is the length of the element list array. */
87 size_t size;
88 /** The count of elements currently stored in this map. */
89 size_t count;
90 };
91
92 /** Structure to publicly denote a key of a UcxMap. */
93 struct UcxKey {
94 /** The key data. */
95 const void *data;
96 /** The length of the key data. */
97 size_t len;
98 /** A cache for the hash value of the key data. */
99 int hash;
100 };
101
102 /** Internal structure for a key of a UcxMap. */
103 struct UcxMapKey {
104 /** The key data. */
105 void *data;
106 /** The length of the key data. */
107 size_t len;
108 /** The hash value of the key data. */
109 int hash;
110 };
111
112 /** Structure for an element of a UcxMap. */
113 struct UcxMapElement {
114 /** The value data. */
115 void *data;
116
117 /** A pointer to the next element in the current list. */
118 UcxMapElement *next;
119
120 /** The corresponding key. */
121 struct UcxMapKey key;
122 };
123
124 /** Structure for an iterator over a UcxMap. */
125 struct UcxMapIterator {
126 /** The map to iterate over. */
127 UcxMap const *map;
128
129 /** The current map element. */
130 UcxMapElement *cur;
131
132 /**
133 * The current index of the element list array.
134 * <b>Attention: </b> this is <b>NOT</b> the element index! Do <b>NOT</b>
135 * manually iterate over the map by increasing this index. Use
136 * ucx_map_iter_next().
137 * @see UcxMap.map*/
138 size_t index;
139 };
140
141 /**
142 * Creates a new hash map with the specified size.
143 * @param size the size of the hash map
144 * @return a pointer to the new hash map
145 */
146 UcxMap *ucx_map_new(size_t size);
147
148 /**
149 * Creates a new hash map with the specified size using a UcxAllocator.
150 * @param allocator the allocator to use
151 * @param size the size of the hash map
152 * @return a pointer to the new hash map
153 */
154 UcxMap *ucx_map_new_a(UcxAllocator *allocator, size_t size);
155
156 /**
157 * Frees a hash map.
158 *
159 * <b>Note:</b> the contents are <b>not</b> freed, use ucx_map_free_content()
160 * before calling this function to achieve that.
161 *
162 * @param map the map to be freed
163 * @see ucx_map_free_content()
164 */
165 void ucx_map_free(UcxMap *map);
166
167 /**
168 * Frees the contents of a hash map.
169 *
170 * This is a convenience function that iterates over the map and passes all
171 * values to the specified destructor function.
172 *
173 * If no destructor is specified (<code>NULL</code>), the free() function of
174 * the map's own allocator is used.
175 *
176 * You must ensure, that it is valid to pass each value in the map to the same
177 * destructor function.
178 *
179 * You should free or clear the map afterwards, as the contents will be invalid.
180 *
181 * @param map for which the contents shall be freed
182 * @param destr optional pointer to a destructor function
183 * @see ucx_map_free()
184 * @see ucx_map_clear()
185 */
186 void ucx_map_free_content(UcxMap *map, ucx_destructor destr);
187
188 /**
189 * Clears a hash map.
190 *
191 * <b>Note:</b> the contents are <b>not</b> freed, use ucx_map_free_content()
192 * before calling this function to achieve that.
193 *
194 * @param map the map to be cleared
195 * @see ucx_map_free_content()
196 */
197 void ucx_map_clear(UcxMap *map);
198
199
200 /**
201 * Copies contents from a map to another map using a copy function.
202 *
203 * <b>Note:</b> The destination map does not need to be empty. However, if it
204 * contains data with keys that are also present in the source map, the contents
205 * are overwritten.
206 *
207 * @param from the source map
208 * @param to the destination map
209 * @param fnc the copy function or <code>NULL</code> if the pointer address
210 * shall be copied
211 * @param data additional data for the copy function
212 * @return 0 on success or a non-zero value on memory allocation errors
213 */
214 int ucx_map_copy(UcxMap const *from, UcxMap *to, copy_func fnc, void *data);
215
216 /**
217 * Clones the map and rehashes if necessary.
218 *
219 * <b>Note:</b> In contrast to ucx_map_rehash() the load factor is irrelevant.
220 * This function <i>always</i> ensures a new UcxMap.size of at least
221 * 2.5*UcxMap.count.
222 *
223 * @param map the map to clone
224 * @param fnc the copy function to use or <code>NULL</code> if the new and
225 * the old map shall share the data pointers
226 * @param data additional data for the copy function
227 * @return the cloned map
228 * @see ucx_map_copy()
229 */
230 UcxMap *ucx_map_clone(UcxMap const *map, copy_func fnc, void *data);
231
232 /**
233 * Clones the map and rehashes if necessary.
234 *
235 * <b>Note:</b> In contrast to ucx_map_rehash() the load factor is irrelevant.
236 * This function <i>always</i> ensures a new UcxMap.size of at least
237 * 2.5*UcxMap.count.
238 *
239 * @param allocator the allocator to use for the cloned map
240 * @param map the map to clone
241 * @param fnc the copy function to use or <code>NULL</code> if the new and
242 * the old map shall share the data pointers
243 * @param data additional data for the copy function
244 * @return the cloned map
245 * @see ucx_map_copy()
246 */
247 UcxMap *ucx_map_clone_a(UcxAllocator *allocator,
248 UcxMap const *map, copy_func fnc, void *data);
249
250 /**
251 * Increases size of the hash map, if necessary.
252 *
253 * The load value is 0.75*UcxMap.size. If the element count exceeds the load
254 * value, the map needs to be rehashed. Otherwise no action is performed and
255 * this function simply returns 0.
256 *
257 * The rehashing process ensures, that the UcxMap.size is at least
258 * 2.5*UcxMap.count. So there is enough room for additional elements without
259 * the need of another soon rehashing.
260 *
261 * You can use this function to dramatically increase access performance.
262 *
263 * @param map the map to rehash
264 * @return 1, if a memory allocation error occurred, 0 otherwise
265 */
266 int ucx_map_rehash(UcxMap *map);
267
268 /**
269 * Puts a key/value-pair into the map.
270 *
271 * @param map the map
272 * @param key the key
273 * @param value the value
274 * @return 0 on success, non-zero value on failure
275 */
276 int ucx_map_put(UcxMap *map, UcxKey key, void *value);
277
278 /**
279 * Retrieves a value by using a key.
280 *
281 * @param map the map
282 * @param key the key
283 * @return the value
284 */
285 void* ucx_map_get(UcxMap const *map, UcxKey key);
286
287 /**
288 * Removes a key/value-pair from the map by using the key.
289 *
290 * @param map the map
291 * @param key the key
292 * @return the removed value
293 */
294 void* ucx_map_remove(UcxMap *map, UcxKey key);
295
296 /**
297 * Shorthand for putting data with a sstr_t key into the map.
298 * @param map the map
299 * @param key the key
300 * @param value the value
301 * @return 0 on success, non-zero value on failure
302 * @see ucx_map_put()
303 */
304 #define ucx_map_sstr_put(map, key, value) \
305 ucx_map_put(map, ucx_key(key.ptr, key.length), (void*)value)
306
307 /**
308 * Shorthand for putting data with a C string key into the map.
309 * @param map the map
310 * @param key the key
311 * @param value the value
312 * @return 0 on success, non-zero value on failure
313 * @see ucx_map_put()
314 */
315 #define ucx_map_cstr_put(map, key, value) \
316 ucx_map_put(map, ucx_key(key, strlen(key)), (void*)value)
317
318 /**
319 * Shorthand for putting data with an integer key into the map.
320 * @param map the map
321 * @param key the key
322 * @param value the value
323 * @return 0 on success, non-zero value on failure
324 * @see ucx_map_put()
325 */
326 #define ucx_map_int_put(map, key, value) \
327 ucx_map_put(map, ucx_key(&key, sizeof(key)), (void*)value)
328
329 /**
330 * Shorthand for getting data from the map with a sstr_t key.
331 * @param map the map
332 * @param key the key
333 * @return the value
334 * @see ucx_map_get()
335 */
336 #define ucx_map_sstr_get(map, key) \
337 ucx_map_get(map, ucx_key(key.ptr, key.length))
338
339 /**
340 * Shorthand for getting data from the map with a C string key.
341 * @param map the map
342 * @param key the key
343 * @return the value
344 * @see ucx_map_get()
345 */
346 #define ucx_map_cstr_get(map, key) \
347 ucx_map_get(map, ucx_key(key, strlen(key)))
348
349 /**
350 * Shorthand for getting data from the map with an integer key.
351 * @param map the map
352 * @param key the key
353 * @return the value
354 * @see ucx_map_get()
355 */
356 #define ucx_map_int_get(map, key) \
357 ucx_map_get(map, ucx_key(&key, sizeof(int)))
358
359 /**
360 * Shorthand for removing data from the map with a sstr_t key.
361 * @param map the map
362 * @param key the key
363 * @return the removed value
364 * @see ucx_map_remove()
365 */
366 #define ucx_map_sstr_remove(map, key) \
367 ucx_map_remove(map, ucx_key(key.ptr, key.length))
368
369 /**
370 * Shorthand for removing data from the map with a C string key.
371 * @param map the map
372 * @param key the key
373 * @return the removed value
374 * @see ucx_map_remove()
375 */
376 #define ucx_map_cstr_remove(map, key) \
377 ucx_map_remove(map, ucx_key(key, strlen(key)))
378
379 /**
380 * Shorthand for removing data from the map with an integer key.
381 * @param map the map
382 * @param key the key
383 * @return the removed value
384 * @see ucx_map_remove()
385 */
386 #define ucx_map_int_remove(map, key) \
387 ucx_map_remove(map, ucx_key(&key, sizeof(key)))
388
389 /**
390 * Creates a UcxKey based on the given data.
391 *
392 * This function implicitly computes the hash.
393 *
394 * @param data the data for the key
395 * @param len the length of the data
396 * @return a UcxKey with implicitly computed hash
397 * @see ucx_hash()
398 */
399 UcxKey ucx_key(const void *data, size_t len);
400
401 /**
402 * Computes a murmur hash-2.
403 *
404 * @param data the data to hash
405 * @param len the length of the data
406 * @return the murmur hash-2 of the data
407 */
408 int ucx_hash(const char *data, size_t len);
409
410 /**
411 * Creates an iterator for a map.
412 *
413 * <b>Note:</b> A UcxMapIterator iterates over all elements in all element
414 * lists successively. Therefore the order highly depends on the key hashes and
415 * may vary under different map sizes. So generally you may <b>NOT</b> rely on
416 * the iteration order.
417 *
418 * <b>Note:</b> The iterator is <b>NOT</b> initialized. You need to call
419 * ucx_map_iter_next() at least once before accessing any information. However,
420 * it is not recommended to access the fields of a UcxMapIterator directly.
421 *
422 * @param map the map to create the iterator for
423 * @return an iterator initialized on the first element of the
424 * first element list
425 * @see ucx_map_iter_next()
426 */
427 UcxMapIterator ucx_map_iterator(UcxMap const *map);
428
429 /**
430 * Proceeds to the next element of the map (if any).
431 *
432 * Subsequent calls on the same iterator proceed to the next element and
433 * store the key/value-pair into the memory specified as arguments of this
434 * function.
435 *
436 * If no further elements are found, this function returns zero and leaves the
437 * last found key/value-pair in memory.
438 *
439 * @param iterator the iterator to use
440 * @param key a pointer to the memory where to store the key
441 * @param value a pointer to the memory where to store the value
442 * @return 1, if another element was found, 0 if all elements has been processed
443 * @see ucx_map_iterator()
444 */
445 int ucx_map_iter_next(UcxMapIterator *iterator, UcxKey *key, void **value);
446
447 /**
448 * Returns the union of two maps.
449 *
450 * The union is a fresh map which is filled by two successive calls of
451 * ucx_map_copy() on the two input maps.
452 *
453 * @param first the first source map
454 * @param second the second source map
455 * @param cpfnc a function to copy the elements
456 * @param cpdata additional data for the copy function
457 * @return a new map containing the union
458 */
459 UcxMap* ucx_map_union(const UcxMap *first, const UcxMap *second,
460 copy_func cpfnc, void* cpdata);
461
462 /**
463 * Returns the union of two maps.
464 *
465 * The union is a fresh map which is filled by two successive calls of
466 * ucx_map_copy() on the two input maps.
467 *
468 * @param allocator the allocator that shall be used by the new map
469 * @param first the first source map
470 * @param second the second source map
471 * @param cpfnc a function to copy the elements
472 * @param cpdata additional data for the copy function
473 * @return a new map containing the union
474 */
475 UcxMap* ucx_map_union_a(UcxAllocator *allocator,
476 const UcxMap *first, const UcxMap *second,
477 copy_func cpfnc, void* cpdata);
478
479 /**
480 * Returns the intersection of two maps.
481 *
482 * The intersection is defined as a copy of the first map with every element
483 * removed that has no valid key in the second map.
484 *
485 * @param first the first source map
486 * @param second the second source map
487 * @param cpfnc a function to copy the elements
488 * @param cpdata additional data for the copy function
489 * @return a new map containing the intersection
490 */
491 UcxMap* ucx_map_intersection(const UcxMap *first, const UcxMap *second,
492 copy_func cpfnc, void* cpdata);
493
494 /**
495 * Returns the intersection of two maps.
496 *
497 * The intersection is defined as a copy of the first map with every element
498 * removed that has no valid key in the second map.
499 *
500 * @param allocator the allocator that shall be used by the new map
501 * @param first the first source map
502 * @param second the second source map
503 * @param cpfnc a function to copy the elements
504 * @param cpdata additional data for the copy function
505 * @return a new map containing the intersection
506 */
507 UcxMap* ucx_map_intersection_a(UcxAllocator *allocator,
508 const UcxMap *first, const UcxMap *second,
509 copy_func cpfnc, void* cpdata);
510
511 /**
512 * Returns the difference of two maps.
513 *
514 * The difference contains a copy of all elements of the first map
515 * for which the corresponding keys cannot be found in the second map.
516 *
517 * @param first the first source map
518 * @param second the second source map
519 * @param cpfnc a function to copy the elements
520 * @param cpdata additional data for the copy function
521 * @return a new list containing the difference
522 */
523 UcxMap* ucx_map_difference(const UcxMap *first, const UcxMap *second,
524 copy_func cpfnc, void* cpdata);
525
526 /**
527 * Returns the difference of two maps.
528 *
529 * The difference contains a copy of all elements of the first map
530 * for which the corresponding keys cannot be found in the second map.
531 *
532 * @param allocator the allocator that shall be used by the new map
533 * @param first the first source map
534 * @param second the second source map
535 * @param cpfnc a function to copy the elements
536 * @param cpdata additional data for the copy function
537 * @return a new list containing the difference
538 */
539 UcxMap* ucx_map_difference_a(UcxAllocator *allocator,
540 const UcxMap *first, const UcxMap *second,
541 copy_func cpfnc, void* cpdata);
542
543
544 #ifdef __cplusplus
545 }
546 #endif
547
548 #endif /* UCX_MAP_H */
549

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