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 #include "cx/array_list.h"
30 #include <assert.h>
31 #include <string.h>
32
33 // LOW LEVEL ARRAY LIST FUNCTIONS
34
35 enum cx_array_copy_result cx_array_copy(
36 void **target,
37 size_t *size,
38 size_t *capacity,
39 size_t index,
40 void const *src,
41 size_t elem_size,
42 size_t elem_count,
43 struct cx_array_reallocator_s *reallocator
44 ) {
45 // assert pointers
46 assert(target != NULL);
47 assert(size != NULL);
48 assert(src != NULL);
49
50 // determine capacity
51 size_t cap = capacity == NULL ? *size : *capacity;
52
53 // check if resize is required
54 size_t minsize = index + elem_count;
55 size_t newsize = *size < minsize ? minsize : *size;
56 bool needrealloc = newsize > cap;
57
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 }
64
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;
70
71 // calculate new capacity (next number divisible by 16)
72 cap = newsize - (newsize % 16) + 16;
73 assert(cap > newsize);
74
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 }
82
83 // repair src pointer, if necessary
84 if (repairsrc) {
85 src = ((char *) newmem) + (srcaddr - targetaddr);
86 }
87
88 // store new pointer and capacity
89 *target = newmem;
90 *capacity = cap;
91 }
92
93 // determine target pointer
94 char *start = *target;
95 start += index * elem_size;
96
97 // copy elements and set new size
98 memmove(start, src, elem_count * elem_size);
99 *size = newsize;
100
101 // return successfully
102 return CX_ARRAY_COPY_SUCCESS;
103 }
104
105 #ifndef CX_ARRAY_SWAP_SBO_SIZE
106 #define CX_ARRAY_SWAP_SBO_SIZE 512
107 #endif
108
109 void cx_array_swap(
110 void *arr,
111 size_t elem_size,
112 size_t idx1,
113 size_t idx2
114 ) {
115 assert(arr != NULL);
116
117 // short circuit
118 if (idx1 == idx2) return;
119
120 char sbo_mem[CX_ARRAY_SWAP_SBO_SIZE];
121 void *tmp;
122
123 // decide if we can use the local buffer
124 if (elem_size > CX_ARRAY_SWAP_SBO_SIZE) {
125 tmp = malloc(elem_size);
126 // we don't want to enforce error handling
127 if (tmp == NULL) abort();
128 } else {
129 tmp = sbo_mem;
130 }
131
132 // calculate memory locations
133 char *left = arr, *right = arr;
134 left += idx1 * elem_size;
135 right += idx2 * elem_size;
136
137 // three-way swap
138 memcpy(tmp, left, elem_size);
139 memcpy(left, right, elem_size);
140 memcpy(right, tmp, elem_size);
141
142 // free dynamic memory, if it was needed
143 if (tmp != sbo_mem) {
144 free(tmp);
145 }
146 }
147
148 // HIGH LEVEL ARRAY LIST FUNCTIONS
149
150 typedef struct {
151 struct cx_list_s base;
152 void *data;
153 size_t capacity;
154 struct cx_array_reallocator_s reallocator;
155 } cx_array_list;
156
157 static void *cx_arl_realloc(
158 void *array,
159 size_t capacity,
160 size_t elem_size,
161 struct cx_array_reallocator_s *alloc
162 ) {
163 // retrieve the pointer to the list allocator
164 CxAllocator const *al = alloc->ptr1;
165
166 // use the list allocator to reallocate the memory
167 return cxRealloc(al, array, capacity * elem_size);
168 }
169
170 static void cx_arl_destructor(struct cx_list_s *list) {
171 cx_array_list *arl = (cx_array_list *) list;
172
173 char *ptr = arl->data;
174
175 if (list->simple_destructor) {
176 for (size_t i = 0; i < list->size; i++) {
177 cx_invoke_simple_destructor(list, ptr);
178 ptr += list->item_size;
179 }
180 }
181 if (list->advanced_destructor) {
182 for (size_t i = 0; i < list->size; i++) {
183 cx_invoke_advanced_destructor(list, ptr);
184 ptr += list->item_size;
185 }
186 }
187
188 cxFree(list->allocator, arl->data);
189 cxFree(list->allocator, list);
190 }
191
192 static size_t cx_arl_insert_array(
193 struct cx_list_s *list,
194 size_t index,
195 void const *array,
196 size_t n
197 ) {
198 // out of bounds and special case check
199 if (index > list->size || n == 0) return 0;
200
201 // get a correctly typed pointer to the list
202 cx_array_list *arl = (cx_array_list *) list;
203
204 // do we need to move some elements?
205 if (index < list->size) {
206 char const *first_to_move = (char const *) arl->data;
207 first_to_move += index * list->item_size;
208 size_t elems_to_move = list->size - index;
209 size_t start_of_moved = index + n;
210
211 if (CX_ARRAY_COPY_SUCCESS != cx_array_copy(
212 &arl->data,
213 &list->size,
214 &arl->capacity,
215 start_of_moved,
216 first_to_move,
217 list->item_size,
218 elems_to_move,
219 &arl->reallocator
220 )) {
221 // if moving existing elems is unsuccessful, abort
222 return 0;
223 }
224 }
225
226 // note that if we had to move the elements, the following operation
227 // is guaranteed to succeed, because we have the memory already allocated
228 // therefore, it is impossible to leave this function with an invalid array
229
230 // place the new elements
231 if (CX_ARRAY_COPY_SUCCESS == cx_array_copy(
232 &arl->data,
233 &list->size,
234 &arl->capacity,
235 index,
236 array,
237 list->item_size,
238 n,
239 &arl->reallocator
240 )) {
241 return n;
242 } else {
243 // array list implementation is "all or nothing"
244 return 0;
245 }
246 }
247
248 static int cx_arl_insert_element(
249 struct cx_list_s *list,
250 size_t index,
251 void const *element
252 ) {
253 return 1 != cx_arl_insert_array(list, index, element, 1);
254 }
255
256 static int cx_arl_insert_iter(
257 struct cx_mut_iterator_s *iter,
258 void const *elem,
259 int prepend
260 ) {
261 struct cx_list_s *list = iter->src_handle;
262 if (iter->index < list->size) {
263 int result = cx_arl_insert_element(
264 list,
265 iter->index + 1 - prepend,
266 elem
267 );
268 if (result == 0 && prepend != 0) {
269 iter->index++;
270 iter->elem_handle = ((char *) iter->elem_handle) + list->item_size;
271 }
272 return result;
273 } else {
274 int result = cx_arl_insert_element(list, list->size, elem);
275 iter->index = list->size;
276 return result;
277 }
278 }
279
280 static int cx_arl_remove(
281 struct cx_list_s *list,
282 size_t index
283 ) {
284 cx_array_list *arl = (cx_array_list *) list;
285
286 // out-of-bounds check
287 if (index >= list->size) {
288 return 1;
289 }
290
291 // content destruction
292 cx_invoke_destructor(list, ((char *) arl->data) + index * list->item_size);
293
294 // short-circuit removal of last element
295 if (index == list->size - 1) {
296 list->size--;
297 return 0;
298 }
299
300 // just move the elements starting at index to the left
301 int result = cx_array_copy(
302 &arl->data,
303 &list->size,
304 &arl->capacity,
305 index,
306 ((char *) arl->data) + (index + 1) * list->item_size,
307 list->item_size,
308 list->size - index - 1,
309 &arl->reallocator
310 );
311 if (result == 0) {
312 // decrease the size
313 list->size--;
314 }
315 return result;
316 }
317
318 static void cx_arl_clear(struct cx_list_s *list) {
319 if (list->size == 0) return;
320
321 cx_array_list *arl = (cx_array_list *) list;
322 char *ptr = arl->data;
323
324 if (list->simple_destructor) {
325 for (size_t i = 0; i < list->size; i++) {
326 cx_invoke_simple_destructor(list, ptr);
327 ptr += list->item_size;
328 }
329 }
330 if (list->advanced_destructor) {
331 for (size_t i = 0; i < list->size; i++) {
332 cx_invoke_advanced_destructor(list, ptr);
333 ptr += list->item_size;
334 }
335 }
336
337 memset(arl->data, 0, list->size * list->item_size);
338 list->size = 0;
339 }
340
341 static int cx_arl_swap(
342 struct cx_list_s *list,
343 size_t i,
344 size_t j
345 ) {
346 if (i >= list->size || j >= list->size) return 1;
347 cx_array_list *arl = (cx_array_list *) list;
348 cx_array_swap(arl->data, list->item_size, i, j);
349 return 0;
350 }
351
352 static void *cx_arl_at(
353 struct cx_list_s const *list,
354 size_t index
355 ) {
356 if (index < list->size) {
357 cx_array_list const *arl = (cx_array_list const *) list;
358 char *space = arl->data;
359 return space + index * list->item_size;
360 } else {
361 return NULL;
362 }
363 }
364
365 static ssize_t cx_arl_find(
366 struct cx_list_s const *list,
367 void const *elem
368 ) {
369 assert(list->cmpfunc != NULL);
370 assert(list->size < SIZE_MAX / 2);
371 char *cur = ((cx_array_list const *) list)->data;
372
373 for (ssize_t i = 0; i < (ssize_t) list->size; i++) {
374 if (0 == list->cmpfunc(elem, cur)) {
375 return i;
376 }
377 cur += list->item_size;
378 }
379
380 return -1;
381 }
382
383 static void cx_arl_sort(struct cx_list_s *list) {
384 assert(list->cmpfunc != NULL);
385 qsort(((cx_array_list *) list)->data,
386 list->size,
387 list->item_size,
388 list->cmpfunc
389 );
390 }
391
392 static int cx_arl_compare(
393 struct cx_list_s const *list,
394 struct cx_list_s const *other
395 ) {
396 assert(list->cmpfunc != NULL);
397 if (list->size == other->size) {
398 char const *left = ((cx_array_list const *) list)->data;
399 char const *right = ((cx_array_list const *) other)->data;
400 for (size_t i = 0; i < list->size; i++) {
401 int d = list->cmpfunc(left, right);
402 if (d != 0) {
403 return d;
404 }
405 left += list->item_size;
406 right += other->item_size;
407 }
408 return 0;
409 } else {
410 return list->size < other->size ? -1 : 1;
411 }
412 }
413
414 static void cx_arl_reverse(struct cx_list_s *list) {
415 if (list->size < 2) return;
416 void *data = ((cx_array_list const *) list)->data;
417 size_t half = list->size / 2;
418 for (size_t i = 0; i < half; i++) {
419 cx_array_swap(data, list->item_size, i, list->size - 1 - i);
420 }
421 }
422
423 static bool cx_arl_iter_valid(void const *it) {
424 struct cx_iterator_s const *iter = it;
425 struct cx_list_s const *list = iter->src_handle;
426 return iter->index < list->size;
427 }
428
429 static void *cx_arl_iter_current(void const *it) {
430 struct cx_iterator_s const *iter = it;
431 return iter->elem_handle;
432 }
433
434 static void cx_arl_iter_next(void *it) {
435 struct cx_iterator_base_s *itbase = it;
436 if (itbase->remove) {
437 struct cx_mut_iterator_s *iter = it;
438 itbase->remove = false;
439 cx_arl_remove(iter->src_handle, iter->index);
440 } else {
441 struct cx_iterator_s *iter = it;
442 iter->index++;
443 iter->elem_handle =
444 ((char *) iter->elem_handle)
445 + ((struct cx_list_s const *) iter->src_handle)->item_size;
446 }
447 }
448
449 static void cx_arl_iter_prev(void *it) {
450 struct cx_iterator_base_s *itbase = it;
451 struct cx_mut_iterator_s *iter = it;
452 cx_array_list *const list = iter->src_handle;
453 if (itbase->remove) {
454 itbase->remove = false;
455 cx_arl_remove(iter->src_handle, iter->index);
456 }
457 iter->index--;
458 if (iter->index < list->base.size) {
459 iter->elem_handle = ((char *) list->data)
460 + iter->index * list->base.item_size;
461 }
462 }
463
464 static bool cx_arl_iter_flag_rm(void *it) {
465 struct cx_iterator_base_s *iter = it;
466 if (iter->mutating) {
467 iter->remove = true;
468 return true;
469 } else {
470 return false;
471 }
472 }
473
474 static struct cx_iterator_s cx_arl_iterator(
475 struct cx_list_s const *list,
476 size_t index,
477 bool backwards
478 ) {
479 struct cx_iterator_s iter;
480
481 iter.index = index;
482 iter.src_handle = list;
483 iter.elem_handle = cx_arl_at(list, index);
484 iter.base.valid = cx_arl_iter_valid;
485 iter.base.current = cx_arl_iter_current;
486 iter.base.next = backwards ? cx_arl_iter_prev : cx_arl_iter_next;
487 iter.base.flag_removal = cx_arl_iter_flag_rm;
488 iter.base.remove = false;
489 iter.base.mutating = false;
490
491 return iter;
492 }
493
494 static cx_list_class cx_array_list_class = {
495 cx_arl_destructor,
496 cx_arl_insert_element,
497 cx_arl_insert_array,
498 cx_arl_insert_iter,
499 cx_arl_remove,
500 cx_arl_clear,
501 cx_arl_swap,
502 cx_arl_at,
503 cx_arl_find,
504 cx_arl_sort,
505 cx_arl_compare,
506 cx_arl_reverse,
507 cx_arl_iterator,
508 };
509
510 CxList *cxArrayListCreate(
511 CxAllocator const *allocator,
512 cx_compare_func comparator,
513 size_t item_size,
514 size_t initial_capacity
515 ) {
516 if (allocator == NULL) {
517 allocator = cxDefaultAllocator;
518 }
519
520 cx_array_list *list = cxCalloc(allocator, 1, sizeof(cx_array_list));
521 if (list == NULL) return NULL;
522
523 list->base.cl = &cx_array_list_class;
524 list->base.allocator = allocator;
525 list->base.cmpfunc = comparator;
526 list->capacity = initial_capacity;
527
528 if (item_size > 0) {
529 list->base.item_size = item_size;
530 } else {
531 item_size = sizeof(void *);
532 cxListStorePointers((CxList *) list);
533 }
534
535 // allocate the array after the real item_size is known
536 list->data = cxCalloc(allocator, initial_capacity, item_size);
537 if (list->data == NULL) {
538 cxFree(allocator, list);
539 return NULL;
540 }
541
542 // configure the reallocator
543 list->reallocator.realloc = cx_arl_realloc;
544 list->reallocator.ptr1 = (void *) allocator;
545
546 return (CxList *) list;
547 }
548