Sun, 20 Nov 2022 16:58:51 +0100
#219 array list: implement reverse
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 /* increase capacity linearly */
72 cap += 16;
74 /* perform reallocation */
75 void *newmem = reallocator->realloc(
76 *target, cap, elem_size, reallocator
77 );
78 if (newmem == NULL) {
79 return CX_ARRAY_COPY_REALLOC_FAILED;
80 }
82 /* repair src pointer, if necessary */
83 if (repairsrc) {
84 src = ((char *) newmem) + (srcaddr - targetaddr);
85 }
87 /* store new pointer and capacity */
88 *target = newmem;
89 *capacity = cap;
90 }
92 /* determine target pointer */
93 char *start = *target;
94 start += index * elem_size;
96 /* copy elements and set new size */
97 memmove(start, src, elem_count * elem_size);
98 *size = newsize;
100 /* return successfully */
101 return CX_ARRAY_COPY_SUCCESS;
102 }
104 #define CX_ARRAY_SWAP_SBO_SIZE 512
106 void cx_array_swap(
107 void *arr,
108 size_t elem_size,
109 size_t idx1,
110 size_t idx2
111 ) {
112 /* short circuit */
113 if (idx1 == idx2) return;
115 char sbo_mem[CX_ARRAY_SWAP_SBO_SIZE];
116 void *tmp;
118 /* decide if we can use the local buffer */
119 if (elem_size > CX_ARRAY_SWAP_SBO_SIZE) {
120 tmp = malloc(elem_size);
121 /* we don't want to enforce error handling */
122 if (tmp == NULL) abort();
123 } else {
124 tmp = sbo_mem;
125 }
127 /* calculate memory locations */
128 char *left = arr, *right = arr;
129 left += idx1 * elem_size;
130 right += idx2 * elem_size;
132 /* three-way swap */
133 memcpy(tmp, left, elem_size);
134 memcpy(left, right, elem_size);
135 memcpy(right, tmp, elem_size);
137 /* free dynamic memory, if it was needed */
138 if (tmp != sbo_mem) {
139 free(tmp);
140 }
141 }
143 /* HIGH LEVEL ARRAY LIST FUNCTIONS */
145 typedef struct {
146 struct cx_list_s base;
147 void *data;
148 struct cx_array_reallocator_s reallocator;
149 } cx_array_list;
151 static void *cx_arl_realloc(
152 void *array,
153 size_t capacity,
154 size_t elem_size,
155 struct cx_array_reallocator_s *alloc
156 ) {
157 /* retrieve the pointer to the list allocator */
158 CxAllocator const *al = alloc->ptr1;
160 /* use the list allocator to reallocate the memory */
161 return cxRealloc(al, array, capacity * elem_size);
162 }
164 static void cx_arl_destructor(struct cx_list_s *list) {
165 cx_array_list *arl = (cx_array_list *) list;
166 cxFree(list->allocator, arl->data);
167 }
169 static int cx_arl_add(
170 struct cx_list_s *list,
171 void const *elem
172 ) {
173 cx_array_list *arl = (cx_array_list *) list;
174 return cx_array_copy(
175 &arl->data,
176 &list->size,
177 &list->capacity,
178 list->size,
179 elem,
180 list->itemsize,
181 1,
182 &arl->reallocator
183 );
184 }
186 static int cx_arl_insert(
187 struct cx_list_s *list,
188 size_t index,
189 void const *elem
190 ) {
191 if (index > list->size) {
192 return 1;
193 } else if (index == list->size) {
194 return cx_arl_add(list, elem);
195 } else {
196 cx_array_list *arl = (cx_array_list *) list;
198 /* move elements starting at index to the right */
199 if (cx_array_copy(
200 &arl->data,
201 &list->size,
202 &list->capacity,
203 index + 1,
204 ((char *) arl->data) + index * list->itemsize,
205 list->itemsize,
206 list->size - index,
207 &arl->reallocator
208 )) {
209 return 1;
210 }
212 /* place the element */
213 memcpy(((char *) arl->data) + index * list->itemsize,
214 elem, list->itemsize);
216 return 0;
217 }
218 }
220 static int cx_arl_insert_iter(
221 struct cx_iterator_s *iter,
222 void const *elem,
223 int prepend
224 ) {
225 struct cx_list_s *list = iter->src_handle;
226 if (iter->index < list->size) {
227 int result = cx_arl_insert(
228 list,
229 iter->index + 1 - prepend,
230 elem
231 );
232 if (result == 0 && prepend != 0) {
233 iter->index++;
234 iter->elem_handle = ((char *) iter->elem_handle) + list->itemsize;
235 }
236 return result;
237 } else {
238 int result = cx_arl_add(list, elem);
239 iter->index = list->size;
240 return result;
241 }
242 }
244 static int cx_arl_remove(
245 struct cx_list_s *list,
246 size_t index
247 ) {
248 /* out-of-bounds check */
249 if (index >= list->size) {
250 return 1;
251 }
253 cx_array_list *arl = (cx_array_list *) list;
255 /* just move the elements starting at index to the left */
256 int result = cx_array_copy(
257 &arl->data,
258 &list->size,
259 &list->capacity,
260 index,
261 ((char *) arl->data) + (index + 1) * list->itemsize,
262 list->itemsize,
263 list->size - index,
264 &arl->reallocator
265 );
266 if (result == 0) {
267 /* decrease the size */
268 list->size--;
269 }
270 return result;
271 }
273 static void *cx_arl_at(
274 struct cx_list_s const *list,
275 size_t index
276 ) {
277 if (index < list->size) {
278 cx_array_list const *arl = (cx_array_list const *) list;
279 char *space = arl->data;
280 return space + index * list->itemsize;
281 } else {
282 return NULL;
283 }
284 }
286 static size_t cx_arl_find(
287 struct cx_list_s const *list,
288 void const *elem
289 ) {
290 char *cur = ((cx_array_list const *) list)->data;
292 for (size_t i = 0; i < list->size; i++) {
293 if (0 == list->cmpfunc(elem, cur)) {
294 return i;
295 }
296 cur += list->itemsize;
297 }
299 return list->size;
300 }
302 static void cx_arl_sort(struct cx_list_s *list) {
303 qsort(((cx_array_list *) list)->data,
304 list->size,
305 list->itemsize,
306 list->cmpfunc
307 );
308 }
310 static int cx_arl_compare(
311 struct cx_list_s const *list,
312 struct cx_list_s const *other
313 ) {
314 if (list->size == other->size) {
315 char const *left = ((cx_array_list const *) list)->data;
316 char const *right = ((cx_array_list const *) other)->data;
317 for (size_t i = 0; i < list->size; i++) {
318 int d = list->cmpfunc(left, right);
319 if (d != 0) {
320 return d;
321 }
322 left += list->itemsize;
323 right += other->itemsize;
324 }
325 return 0;
326 } else {
327 return list->size < other->size ? -1 : 1;
328 }
329 }
331 static void cx_arl_reverse(struct cx_list_s *list) {
332 if (list->size < 2) return;
333 void *data = ((cx_array_list const *) list)->data;
334 size_t half = list->size / 2;
335 for (size_t i = 0; i < half; i++) {
336 cx_array_swap(data, list->itemsize, i, list->size - 1 - i);
337 }
338 }
340 static bool cx_arl_iter_valid(struct cx_iterator_s const *iter) {
341 struct cx_list_s const *list = iter->src_handle;
342 return iter->index < list->size;
343 }
345 static void *cx_arl_iter_current(struct cx_iterator_s const *iter) {
346 return iter->elem_handle;
347 }
349 static void cx_arl_iter_next(struct cx_iterator_s *iter) {
350 if (iter->remove) {
351 iter->remove = false;
352 cx_arl_remove(iter->src_handle, iter->index);
353 } else {
354 iter->index++;
355 iter->elem_handle =
356 ((char *) iter->elem_handle)
357 + ((struct cx_list_s const *) iter->src_handle)->itemsize;
358 }
359 }
361 static struct cx_iterator_s cx_arl_iterator(
362 struct cx_list_s *list,
363 size_t index
364 ) {
365 struct cx_iterator_s iter;
367 iter.index = index;
368 iter.src_handle = list;
369 iter.elem_handle = cx_arl_at(list, index);
370 iter.valid = cx_arl_iter_valid;
371 iter.current = cx_arl_iter_current;
372 iter.next = cx_arl_iter_next;
373 iter.remove = false;
375 return iter;
376 }
378 static cx_list_class cx_array_list_class = {
379 cx_arl_destructor,
380 cx_arl_add,
381 cx_arl_insert,
382 cx_arl_insert_iter,
383 cx_arl_remove,
384 cx_arl_at,
385 cx_arl_find,
386 cx_arl_sort,
387 cx_arl_compare,
388 cx_arl_reverse,
389 cx_arl_iterator,
390 };
392 CxList *cxArrayListCreate(
393 CxAllocator const *allocator,
394 CxListComparator comparator,
395 size_t item_size,
396 size_t initial_capacity
397 ) {
398 cx_array_list *list = cxCalloc(allocator, 1, sizeof(cx_array_list));
399 if (list == NULL) return NULL;
401 list->data = cxCalloc(allocator, initial_capacity, item_size);
402 if (list->data == NULL) {
403 cxFree(allocator, list);
404 return NULL;
405 }
407 list->base.cl = &cx_array_list_class;
408 list->base.allocator = allocator;
409 list->base.cmpfunc = comparator;
410 list->base.itemsize = item_size;
411 list->base.capacity = initial_capacity;
413 /* configure the reallocator */
414 list->reallocator.realloc = cx_arl_realloc;
415 list->reallocator.ptr1 = (void *) allocator;
417 return (CxList *) list;
418 }