Thu, 23 Feb 2023 18:58:15 +0100
make hashmap store objects instead of pointers by default - fixes #239
1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
3 *
4 * Copyright 2021 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 * \file map.h
30 * \brief Interface for map implementations.
31 * \author Mike Becker
32 * \author Olaf Wintermann
33 * \version 3.0
34 * \copyright 2-Clause BSD License
35 */
37 #ifndef UCX_MAP_H
38 #define UCX_MAP_H
40 #include "common.h"
41 #include "allocator.h"
42 #include "iterator.h"
43 #include "hash_key.h"
45 #ifdef __cplusplus
46 extern "C" {
47 #endif
49 /** Type for the UCX map. */
50 typedef struct cx_map_s CxMap;
52 /** Type for a map entry. */
53 typedef struct cx_map_entry_s CxMapEntry;
55 /** Type for map class definitions. */
56 typedef struct cx_map_class_s cx_map_class;
58 /** Structure for the UCX map. */
59 struct cx_map_s {
60 /** The map class definition. */
61 cx_map_class *cl;
62 /** An allocator that is used for the map elements. */
63 CxAllocator *allocator;
64 /** The number of elements currently stored. */
65 size_t size;
66 /**
67 * The size of an element.
68 */
69 size_t itemsize;
70 /**
71 * True, if this map shall store pointers instead
72 * of copies of objects.
73 */
74 bool store_pointers;
75 };
77 /**
78 * The class definition for arbitrary maps.
79 */
80 struct cx_map_class_s {
81 /**
82 * Deallocates the entire memory.
83 */
84 __attribute__((__nonnull__))
85 void (*destructor)(struct cx_map_s *map);
87 /**
88 * Removes all elements.
89 */
90 __attribute__((__nonnull__))
91 void (*clear)(struct cx_map_s *map);
93 /**
94 * Add or overwrite an element.
95 */
96 __attribute__((__nonnull__))
97 int (*put)(
98 CxMap *map,
99 CxHashKey key,
100 void *value
101 );
103 /**
104 * Returns an element.
105 */
106 __attribute__((__nonnull__, __warn_unused_result__))
107 void *(*get)(
108 CxMap const *map,
109 CxHashKey key
110 );
112 /**
113 * Removes an element.
114 */
115 __attribute__((__nonnull__, __warn_unused_result__))
116 void *(*remove)(
117 CxMap *map,
118 CxHashKey key
119 );
121 /**
122 * Iterator over the key/value pairs.
123 */
124 __attribute__((__nonnull__, __warn_unused_result__))
125 CxIterator (*iterator)(CxMap const *map);
127 /**
128 * Iterator over the keys.
129 */
130 __attribute__((__nonnull__, __warn_unused_result__))
131 CxIterator (*iterator_keys)(CxMap const *map);
133 /**
134 * Iterator over the values.
135 */
136 __attribute__((__nonnull__, __warn_unused_result__))
137 CxIterator (*iterator_values)(CxMap const *map);
139 /**
140 * Mutating iterator over the key/value pairs.
141 */
142 __attribute__((__nonnull__, __warn_unused_result__))
143 CxMutIterator (*mut_iterator)(CxMap *map);
145 /**
146 * Mutating iterator over the keys.
147 */
148 __attribute__((__nonnull__, __warn_unused_result__))
149 CxMutIterator (*mut_iterator_keys)(CxMap *map);
151 /**
152 * Mutating iterator over the values.
153 */
154 __attribute__((__nonnull__, __warn_unused_result__))
155 CxMutIterator (*mut_iterator_values)(CxMap *map);
156 };
158 /**
159 * A map entry.
160 */
161 struct cx_map_entry_s {
162 /**
163 * A pointer to the key.
164 */
165 CxHashKey const *key;
166 /**
167 * A pointer to the value.
168 */
169 void *value;
170 };
172 /**
173 * Advises the map to store copies of the objects (default mode of operation).
174 *
175 * Retrieving objects from this map will yield pointers to the copies stored
176 * within this list.
177 *
178 * @param map the map
179 * @see cxMapStorePointers()
180 */
181 __attribute__((__nonnull__))
182 static inline void cxMapStoreObjects(CxMap *map) {
183 map->store_pointers = false;
184 }
186 /**
187 * Advises the map to only store pointers to the objects.
188 *
189 * Retrieving objects from this list will yield the original pointers stored.
190 *
191 * @note This function forcibly sets the element size to the size of a pointer.
192 * Invoking this function on a non-empty map that already stores copies of
193 * objects is undefined.
194 *
195 * @param map the map
196 * @see cxMapStoreObjects()
197 */
198 __attribute__((__nonnull__))
199 static inline void cxMapStorePointers(CxMap *map) {
200 map->store_pointers = true;
201 map->itemsize = sizeof(void *);
202 }
205 /**
206 * Deallocates the memory of the specified map.
207 *
208 * @param map the map to be destroyed
209 */
210 __attribute__((__nonnull__))
211 static inline void cxMapDestroy(CxMap *map) {
212 // TODO: likely to add auto-free feature for contents in the future
213 map->cl->destructor(map);
214 }
217 /**
218 * Clears a map by removing all elements.
219 *
220 * @param map the map to be cleared
221 */
222 __attribute__((__nonnull__))
223 static inline void cxMapClear(CxMap *map) {
224 map->cl->clear(map);
225 }
227 /**
228 * Puts a key/value-pair into the map.
229 *
230 * @param map the map
231 * @param key the key
232 * @param value the value
233 * @return 0 on success, non-zero value on failure
234 */
235 __attribute__((__nonnull__))
236 static inline int cxMapPut(
237 CxMap *map,
238 CxHashKey key,
239 void *value
240 ) {
241 return map->cl->put(map, key, value);
242 }
244 /**
245 * Retrieves a value by using a key.
246 *
247 * @param map the map
248 * @param key the key
249 * @return the value
250 */
251 __attribute__((__nonnull__, __warn_unused_result__))
252 static inline void *cxMapGet(
253 CxMap const *map,
254 CxHashKey key
255 ) {
256 return map->cl->get(map, key);
257 }
259 /**
260 * Removes a key/value-pair from the map by using the key.
261 *
262 * @param map the map
263 * @param key the key
264 * @return if this map is storing pointers, the removed value, \c NULL otherwise
265 * @see cxMapStorePointers()
266 */
267 __attribute__((__nonnull__, __warn_unused_result__))
268 static inline void *cxMapRemove(
269 CxMap *map,
270 CxHashKey key
271 ) {
272 return map->cl->remove(map, key);
273 }
275 // TODO: set-like map operations (union, intersect, difference)
277 /**
278 * Creates a value iterator for a map.
279 *
280 * \note An iterator iterates over all elements successively. Therefore the order
281 * highly depends on the map implementation and may change arbitrarily when the contents change.
282 *
283 * @param map the map to create the iterator for
284 * @return an iterator for the currently stored values
285 */
286 __attribute__((__nonnull__, __warn_unused_result__))
287 static inline CxIterator cxMapIteratorValues(CxMap *map) {
288 return map->cl->iterator_values(map);
289 }
291 /**
292 * Creates a key iterator for a map.
293 *
294 * The elements of the iterator are keys of type CxHashKey.
295 *
296 * \note An iterator iterates over all elements successively. Therefore the order
297 * highly depends on the map implementation and may change arbitrarily when the contents change.
298 *
299 * @param map the map to create the iterator for
300 * @return an iterator for the currently stored keys
301 */
302 __attribute__((__nonnull__, __warn_unused_result__))
303 static inline CxIterator cxMapIteratorKeys(CxMap *map) {
304 return map->cl->iterator_keys(map);
305 }
307 /**
308 * Creates an iterator for a map.
309 *
310 * The elements of the iterator are key/value pairs of type CxMapEntry.
311 *
312 * \note An iterator iterates over all elements successively. Therefore the order
313 * highly depends on the map implementation and may change arbitrarily when the contents change.
314 *
315 * @param map the map to create the iterator for
316 * @return an iterator for the currently stored entries
317 * @see cxMapIteratorKeys()
318 * @see cxMapIteratorValues()
319 */
320 __attribute__((__nonnull__, __warn_unused_result__))
321 static inline CxIterator cxMapIterator(CxMap *map) {
322 return map->cl->iterator(map);
323 }
326 /**
327 * Creates a mutating iterator over the values of a map.
328 *
329 * \note An iterator iterates over all elements successively. Therefore the order
330 * highly depends on the map implementation and may change arbitrarily when the contents change.
331 *
332 * @param map the map to create the iterator for
333 * @return an iterator for the currently stored values
334 */
335 __attribute__((__nonnull__, __warn_unused_result__))
336 static inline CxMutIterator cxMapMutIteratorValues(CxMap *map) {
337 return map->cl->mut_iterator_values(map);
338 }
340 /**
341 * Creates a mutating iterator over the keys of a map.
342 *
343 * The elements of the iterator are keys of type CxHashKey.
344 *
345 * \note An iterator iterates over all elements successively. Therefore the order
346 * highly depends on the map implementation and may change arbitrarily when the contents change.
347 *
348 * @param map the map to create the iterator for
349 * @return an iterator for the currently stored keys
350 */
351 __attribute__((__nonnull__, __warn_unused_result__))
352 static inline CxMutIterator cxMapMutIteratorKeys(CxMap *map) {
353 return map->cl->mut_iterator_keys(map);
354 }
356 /**
357 * Creates a mutating iterator for a map.
358 *
359 * The elements of the iterator are key/value pairs of type CxMapEntry.
360 *
361 * \note An iterator iterates over all elements successively. Therefore the order
362 * highly depends on the map implementation and may change arbitrarily when the contents change.
363 *
364 * @param map the map to create the iterator for
365 * @return an iterator for the currently stored entries
366 * @see cxMapMutIteratorKeys()
367 * @see cxMapMutIteratorValues()
368 */
369 __attribute__((__nonnull__, __warn_unused_result__))
370 static inline CxMutIterator cxMapMutIterator(CxMap *map) {
371 return map->cl->mut_iterator(map);
372 }
374 #ifdef __cplusplus
375 }
376 #endif
378 #endif // UCX_MAP_H