Sun, 20 Nov 2022 17:22:37 +0100
fix calculation of new capacity in cx_array_copy()
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 */
29 #include "cx/array_list.h"
30 #include <assert.h>
31 #include <string.h>
32 #include <stdint.h>
34 /* LOW LEVEL ARRAY LIST FUNCTIONS */
36 enum cx_array_copy_result cx_array_copy(
37 void **target,
38 size_t *size,
39 size_t *capacity,
40 size_t index,
41 void const *src,
42 size_t elem_size,
43 size_t elem_count,
44 struct cx_array_reallocator_s *reallocator
45 ) {
46 /* assert pointers */
47 assert(target != NULL);
48 assert(size != NULL);
49 assert(src != NULL);
51 /* determine capacity */
52 size_t cap = capacity == NULL ? *size : *capacity;
54 /* check if resize is required */
55 size_t newsize = index + elem_count;
56 bool needrealloc = newsize > cap;
58 /* reallocate if possible */
59 if (needrealloc) {
60 /* a reallocator and a capacity variable must be available */
61 if (reallocator == NULL || capacity == NULL) {
62 return CX_ARRAY_COPY_REALLOC_NOT_SUPPORTED;
63 }
65 /* check, if we need to repair the src pointer */
66 uintptr_t targetaddr = (uintptr_t) *target;
67 uintptr_t srcaddr = (uintptr_t) src;
68 bool repairsrc = targetaddr <= srcaddr
69 && srcaddr < targetaddr + cap * elem_size;
71 /* calculate new capacity (next number divisible by 16) */
72 cap = newsize - (newsize % 16) + 16;
73 assert(cap > newsize);
75 /* perform reallocation */
76 void *newmem = reallocator->realloc(
77 *target, cap, elem_size, reallocator
78 );
79 if (newmem == NULL) {
80 return CX_ARRAY_COPY_REALLOC_FAILED;
81 }
83 /* repair src pointer, if necessary */
84 if (repairsrc) {
85 src = ((char *) newmem) + (srcaddr - targetaddr);
86 }
88 /* store new pointer and capacity */
89 *target = newmem;
90 *capacity = cap;
91 }
93 /* determine target pointer */
94 char *start = *target;
95 start += index * elem_size;
97 /* copy elements and set new size */
98 memmove(start, src, elem_count * elem_size);
99 *size = newsize;
101 /* return successfully */
102 return CX_ARRAY_COPY_SUCCESS;
103 }
105 #define CX_ARRAY_SWAP_SBO_SIZE 512
107 void cx_array_swap(
108 void *arr,
109 size_t elem_size,
110 size_t idx1,
111 size_t idx2
112 ) {
113 /* short circuit */
114 if (idx1 == idx2) return;
116 char sbo_mem[CX_ARRAY_SWAP_SBO_SIZE];
117 void *tmp;
119 /* decide if we can use the local buffer */
120 if (elem_size > CX_ARRAY_SWAP_SBO_SIZE) {
121 tmp = malloc(elem_size);
122 /* we don't want to enforce error handling */
123 if (tmp == NULL) abort();
124 } else {
125 tmp = sbo_mem;
126 }
128 /* calculate memory locations */
129 char *left = arr, *right = arr;
130 left += idx1 * elem_size;
131 right += idx2 * elem_size;
133 /* three-way swap */
134 memcpy(tmp, left, elem_size);
135 memcpy(left, right, elem_size);
136 memcpy(right, tmp, elem_size);
138 /* free dynamic memory, if it was needed */
139 if (tmp != sbo_mem) {
140 free(tmp);
141 }
142 }
144 /* HIGH LEVEL ARRAY LIST FUNCTIONS */
146 typedef struct {
147 struct cx_list_s base;
148 void *data;
149 struct cx_array_reallocator_s reallocator;
150 } cx_array_list;
152 static void *cx_arl_realloc(
153 void *array,
154 size_t capacity,
155 size_t elem_size,
156 struct cx_array_reallocator_s *alloc
157 ) {
158 /* retrieve the pointer to the list allocator */
159 CxAllocator const *al = alloc->ptr1;
161 /* use the list allocator to reallocate the memory */
162 return cxRealloc(al, array, capacity * elem_size);
163 }
165 static void cx_arl_destructor(struct cx_list_s *list) {
166 cx_array_list *arl = (cx_array_list *) list;
167 cxFree(list->allocator, arl->data);
168 }
170 static int cx_arl_add(
171 struct cx_list_s *list,
172 void const *elem
173 ) {
174 cx_array_list *arl = (cx_array_list *) list;
175 return cx_array_copy(
176 &arl->data,
177 &list->size,
178 &list->capacity,
179 list->size,
180 elem,
181 list->itemsize,
182 1,
183 &arl->reallocator
184 );
185 }
187 static int cx_arl_insert(
188 struct cx_list_s *list,
189 size_t index,
190 void const *elem
191 ) {
192 if (index > list->size) {
193 return 1;
194 } else if (index == list->size) {
195 return cx_arl_add(list, elem);
196 } else {
197 cx_array_list *arl = (cx_array_list *) list;
199 /* move elements starting at index to the right */
200 if (cx_array_copy(
201 &arl->data,
202 &list->size,
203 &list->capacity,
204 index + 1,
205 ((char *) arl->data) + index * list->itemsize,
206 list->itemsize,
207 list->size - index,
208 &arl->reallocator
209 )) {
210 return 1;
211 }
213 /* place the element */
214 memcpy(((char *) arl->data) + index * list->itemsize,
215 elem, list->itemsize);
217 return 0;
218 }
219 }
221 static int cx_arl_insert_iter(
222 struct cx_iterator_s *iter,
223 void const *elem,
224 int prepend
225 ) {
226 struct cx_list_s *list = iter->src_handle;
227 if (iter->index < list->size) {
228 int result = cx_arl_insert(
229 list,
230 iter->index + 1 - prepend,
231 elem
232 );
233 if (result == 0 && prepend != 0) {
234 iter->index++;
235 iter->elem_handle = ((char *) iter->elem_handle) + list->itemsize;
236 }
237 return result;
238 } else {
239 int result = cx_arl_add(list, elem);
240 iter->index = list->size;
241 return result;
242 }
243 }
245 static int cx_arl_remove(
246 struct cx_list_s *list,
247 size_t index
248 ) {
249 /* out-of-bounds check */
250 if (index >= list->size) {
251 return 1;
252 }
254 /* short-circuit removal of last element */
255 if (index == list->size - 1) {
256 list->size--;
257 return 0;
258 }
260 /* just move the elements starting at index to the left */
261 cx_array_list *arl = (cx_array_list *) list;
262 int result = cx_array_copy(
263 &arl->data,
264 &list->size,
265 &list->capacity,
266 index,
267 ((char *) arl->data) + (index + 1) * list->itemsize,
268 list->itemsize,
269 list->size - index,
270 &arl->reallocator
271 );
272 if (result == 0) {
273 /* decrease the size */
274 list->size--;
275 }
276 return result;
277 }
279 static void *cx_arl_at(
280 struct cx_list_s const *list,
281 size_t index
282 ) {
283 if (index < list->size) {
284 cx_array_list const *arl = (cx_array_list const *) list;
285 char *space = arl->data;
286 return space + index * list->itemsize;
287 } else {
288 return NULL;
289 }
290 }
292 static size_t cx_arl_find(
293 struct cx_list_s const *list,
294 void const *elem
295 ) {
296 char *cur = ((cx_array_list const *) list)->data;
298 for (size_t i = 0; i < list->size; i++) {
299 if (0 == list->cmpfunc(elem, cur)) {
300 return i;
301 }
302 cur += list->itemsize;
303 }
305 return list->size;
306 }
308 static void cx_arl_sort(struct cx_list_s *list) {
309 qsort(((cx_array_list *) list)->data,
310 list->size,
311 list->itemsize,
312 list->cmpfunc
313 );
314 }
316 static int cx_arl_compare(
317 struct cx_list_s const *list,
318 struct cx_list_s const *other
319 ) {
320 if (list->size == other->size) {
321 char const *left = ((cx_array_list const *) list)->data;
322 char const *right = ((cx_array_list const *) other)->data;
323 for (size_t i = 0; i < list->size; i++) {
324 int d = list->cmpfunc(left, right);
325 if (d != 0) {
326 return d;
327 }
328 left += list->itemsize;
329 right += other->itemsize;
330 }
331 return 0;
332 } else {
333 return list->size < other->size ? -1 : 1;
334 }
335 }
337 static void cx_arl_reverse(struct cx_list_s *list) {
338 if (list->size < 2) return;
339 void *data = ((cx_array_list const *) list)->data;
340 size_t half = list->size / 2;
341 for (size_t i = 0; i < half; i++) {
342 cx_array_swap(data, list->itemsize, i, list->size - 1 - i);
343 }
344 }
346 static bool cx_arl_iter_valid(struct cx_iterator_s const *iter) {
347 struct cx_list_s const *list = iter->src_handle;
348 return iter->index < list->size;
349 }
351 static void *cx_arl_iter_current(struct cx_iterator_s const *iter) {
352 return iter->elem_handle;
353 }
355 static void cx_arl_iter_next(struct cx_iterator_s *iter) {
356 if (iter->remove) {
357 iter->remove = false;
358 cx_arl_remove(iter->src_handle, iter->index);
359 } else {
360 iter->index++;
361 iter->elem_handle =
362 ((char *) iter->elem_handle)
363 + ((struct cx_list_s const *) iter->src_handle)->itemsize;
364 }
365 }
367 static struct cx_iterator_s cx_arl_iterator(
368 struct cx_list_s *list,
369 size_t index
370 ) {
371 struct cx_iterator_s iter;
373 iter.index = index;
374 iter.src_handle = list;
375 iter.elem_handle = cx_arl_at(list, index);
376 iter.valid = cx_arl_iter_valid;
377 iter.current = cx_arl_iter_current;
378 iter.next = cx_arl_iter_next;
379 iter.remove = false;
381 return iter;
382 }
384 static cx_list_class cx_array_list_class = {
385 cx_arl_destructor,
386 cx_arl_add,
387 cx_arl_insert,
388 cx_arl_insert_iter,
389 cx_arl_remove,
390 cx_arl_at,
391 cx_arl_find,
392 cx_arl_sort,
393 cx_arl_compare,
394 cx_arl_reverse,
395 cx_arl_iterator,
396 };
398 CxList *cxArrayListCreate(
399 CxAllocator const *allocator,
400 CxListComparator comparator,
401 size_t item_size,
402 size_t initial_capacity
403 ) {
404 cx_array_list *list = cxCalloc(allocator, 1, sizeof(cx_array_list));
405 if (list == NULL) return NULL;
407 list->data = cxCalloc(allocator, initial_capacity, item_size);
408 if (list->data == NULL) {
409 cxFree(allocator, list);
410 return NULL;
411 }
413 list->base.cl = &cx_array_list_class;
414 list->base.allocator = allocator;
415 list->base.cmpfunc = comparator;
416 list->base.itemsize = item_size;
417 list->base.capacity = initial_capacity;
419 /* configure the reallocator */
420 list->reallocator.realloc = cx_arl_realloc;
421 list->reallocator.ptr1 = (void *) allocator;
423 return (CxList *) list;
424 }