src/linked_list.c@2e6e9d9f2159
src/linked_list.c
Wed, 08 Feb 2023 20:26:09 +0100
- author
- Mike Becker <universe@uap-core.de>
- date
- Wed, 08 Feb 2023 20:26:09 +0100
- changeset 647
- 2e6e9d9f2159
- parent 641
- d402fead3386
- child 654
- c9d008861178
- permissions
- -rw-r--r--
implement swap function for list elements - fixes #218
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/linked_list.h"
30 #include "cx/utils.h"
31 #include <stdint.h>
32 #include <string.h>
33 #include <assert.h>
35 // LOW LEVEL LINKED LIST FUNCTIONS
37 #define CX_LL_PTR(cur, off) (*(void**)(((char*)(cur))+(off)))
38 #define ll_prev(node) CX_LL_PTR(node, loc_prev)
39 #define ll_next(node) CX_LL_PTR(node, loc_next)
40 #define ll_advance(node) CX_LL_PTR(node, loc_advance)
41 #define ll_data(node) (((char*)(node))+loc_data)
43 void *cx_linked_list_at(
44 void const *start,
45 size_t start_index,
46 ptrdiff_t loc_advance,
47 size_t index
48 ) {
49 assert(start != NULL);
50 assert(loc_advance >= 0);
51 size_t i = start_index;
52 void const *cur = start;
53 while (i != index && cur != NULL) {
54 cur = ll_advance(cur);
55 i < index ? i++ : i--;
56 }
57 return (void *) cur;
58 }
60 size_t cx_linked_list_find(
61 void const *start,
62 ptrdiff_t loc_advance,
63 ptrdiff_t loc_data,
64 CxListComparator cmp_func,
65 void const *elem
66 ) {
67 assert(start != NULL);
68 assert(loc_advance >= 0);
69 assert(loc_data >= 0);
70 assert(cmp_func);
72 void const *node = start;
73 size_t index = 0;
74 do {
75 void *current = ll_data(node);
76 if (cmp_func(current, elem) == 0) {
77 return index;
78 }
79 node = ll_advance(node);
80 index++;
81 } while (node != NULL);
82 return index;
83 }
85 void *cx_linked_list_first(
86 void const *node,
87 ptrdiff_t loc_prev
88 ) {
89 return cx_linked_list_last(node, loc_prev);
90 }
92 void *cx_linked_list_last(
93 void const *node,
94 ptrdiff_t loc_next
95 ) {
96 assert(node != NULL);
97 assert(loc_next >= 0);
99 void const *cur = node;
100 void const *last;
101 do {
102 last = cur;
103 } while ((cur = ll_next(cur)) != NULL);
105 return (void *) last;
106 }
108 void *cx_linked_list_prev(
109 void const *begin,
110 ptrdiff_t loc_next,
111 void const *node
112 ) {
113 assert(begin != NULL);
114 assert(node != NULL);
115 assert(loc_next >= 0);
116 if (begin == node) return NULL;
117 void const *cur = begin;
118 void const *next;
119 while (1) {
120 next = ll_next(cur);
121 if (next == node) return (void *) cur;
122 cur = next;
123 }
124 }
126 void cx_linked_list_link(
127 void *left,
128 void *right,
129 ptrdiff_t loc_prev,
130 ptrdiff_t loc_next
131 ) {
132 assert(loc_next >= 0);
133 ll_next(left) = right;
134 if (loc_prev >= 0) {
135 ll_prev(right) = left;
136 }
137 }
139 void cx_linked_list_unlink(
140 void *left,
141 void *right,
142 ptrdiff_t loc_prev,
143 ptrdiff_t loc_next
144 ) {
145 assert (loc_next >= 0);
146 assert(ll_next(left) == right);
147 ll_next(left) = NULL;
148 if (loc_prev >= 0) {
149 assert(ll_prev(right) == left);
150 ll_prev(right) = NULL;
151 }
152 }
154 void cx_linked_list_add(
155 void **begin,
156 void **end,
157 ptrdiff_t loc_prev,
158 ptrdiff_t loc_next,
159 void *new_node
160 ) {
161 void *last;
162 if (end == NULL) {
163 assert(begin != NULL);
164 last = *begin == NULL ? NULL : cx_linked_list_last(*begin, loc_next);
165 } else {
166 last = *end;
167 }
168 cx_linked_list_insert_chain(begin, end, loc_prev, loc_next, last, new_node, new_node);
169 }
171 void cx_linked_list_prepend(
172 void **begin,
173 void **end,
174 ptrdiff_t loc_prev,
175 ptrdiff_t loc_next,
176 void *new_node
177 ) {
178 cx_linked_list_insert_chain(begin, end, loc_prev, loc_next, NULL, new_node, new_node);
179 }
181 void cx_linked_list_insert(
182 void **begin,
183 void **end,
184 ptrdiff_t loc_prev,
185 ptrdiff_t loc_next,
186 void *node,
187 void *new_node
188 ) {
189 cx_linked_list_insert_chain(begin, end, loc_prev, loc_next, node, new_node, new_node);
190 }
192 void cx_linked_list_insert_chain(
193 void **begin,
194 void **end,
195 ptrdiff_t loc_prev,
196 ptrdiff_t loc_next,
197 void *node,
198 void *insert_begin,
199 void *insert_end
200 ) {
201 // find the end of the chain, if not specified
202 if (insert_end == NULL) {
203 insert_end = cx_linked_list_last(insert_begin, loc_next);
204 }
206 // determine the successor
207 void *successor;
208 if (node == NULL) {
209 assert(begin != NULL || (end != NULL && loc_prev >= 0));
210 if (begin != NULL) {
211 successor = *begin;
212 *begin = insert_begin;
213 } else {
214 successor = *end == NULL ? NULL : cx_linked_list_first(*end, loc_prev);
215 }
216 } else {
217 successor = ll_next(node);
218 cx_linked_list_link(node, insert_begin, loc_prev, loc_next);
219 }
221 if (successor == NULL) {
222 // the list ends with the new chain
223 if (end != NULL) {
224 *end = insert_end;
225 }
226 } else {
227 cx_linked_list_link(insert_end, successor, loc_prev, loc_next);
228 }
229 }
231 void cx_linked_list_remove(
232 void **begin,
233 void **end,
234 ptrdiff_t loc_prev,
235 ptrdiff_t loc_next,
236 void *node
237 ) {
238 assert(node != NULL);
239 assert(loc_next >= 0);
240 assert(loc_prev >= 0 || begin != NULL);
242 // find adjacent nodes
243 void *next = ll_next(node);
244 void *prev;
245 if (loc_prev >= 0) {
246 prev = ll_prev(node);
247 } else {
248 prev = cx_linked_list_prev(*begin, loc_next, node);
249 }
251 // update next pointer of prev node, or set begin
252 if (prev == NULL) {
253 if (begin != NULL) {
254 *begin = next;
255 }
256 } else {
257 ll_next(prev) = next;
258 }
260 // update prev pointer of next node, or set end
261 if (next == NULL) {
262 if (end != NULL) {
263 *end = prev;
264 }
265 } else if (loc_prev >= 0) {
266 ll_prev(next) = prev;
267 }
268 }
270 size_t cx_linked_list_size(
271 void const *node,
272 ptrdiff_t loc_next
273 ) {
274 assert(loc_next >= 0);
275 size_t size = 0;
276 while (node != NULL) {
277 node = ll_next(node);
278 size++;
279 }
280 return size;
281 }
283 static void *cx_linked_list_sort_merge(
284 ptrdiff_t loc_prev,
285 ptrdiff_t loc_next,
286 ptrdiff_t loc_data,
287 size_t length,
288 void *ls,
289 void *le,
290 void *re,
291 CxListComparator cmp_func
292 ) {
293 const size_t sbo_len = 1024;
294 void *sbo[sbo_len];
295 void **sorted = (length >= sbo_len) ? malloc(sizeof(void *) * length) : sbo;
296 if (sorted == NULL) abort();
297 void *rc, *lc;
299 lc = ls;
300 rc = le;
301 size_t n = 0;
302 while (lc && lc != le && rc != re) {
303 if (cmp_func(ll_data(lc), ll_data(rc)) <= 0) {
304 sorted[n] = lc;
305 lc = ll_next(lc);
306 } else {
307 sorted[n] = rc;
308 rc = ll_next(rc);
309 }
310 n++;
311 }
312 while (lc && lc != le) {
313 sorted[n] = lc;
314 lc = ll_next(lc);
315 n++;
316 }
317 while (rc && rc != re) {
318 sorted[n] = rc;
319 rc = ll_next(rc);
320 n++;
321 }
323 // Update pointer
324 if (loc_prev >= 0) ll_prev(sorted[0]) = NULL;
325 cx_for_n (i, length - 1) {
326 cx_linked_list_link(sorted[i], sorted[i + 1], loc_prev, loc_next);
327 }
328 ll_next(sorted[length - 1]) = NULL;
330 void *ret = sorted[0];
331 if (sorted != sbo) {
332 free(sorted);
333 }
334 return ret;
335 }
337 void cx_linked_list_sort( // NOLINT(misc-no-recursion) - purposely recursive function
338 void **begin,
339 void **end,
340 ptrdiff_t loc_prev,
341 ptrdiff_t loc_next,
342 ptrdiff_t loc_data,
343 CxListComparator cmp_func
344 ) {
345 assert(begin != NULL);
346 assert(loc_next >= 0);
347 assert(loc_data >= 0);
348 assert(cmp_func);
350 void *lc, *ls, *le, *re;
352 // set start node
353 ls = *begin;
355 // check how many elements are already sorted
356 lc = ls;
357 size_t ln = 1;
358 while (ll_next(lc) != NULL && cmp_func(ll_data(ll_next(lc)), ll_data(lc)) > 0) {
359 lc = ll_next(lc);
360 ln++;
361 }
362 le = ll_next(lc);
364 // if first unsorted node is NULL, the list is already completely sorted
365 if (le != NULL) {
366 void *rc;
367 size_t rn = 1;
368 rc = le;
369 // skip already sorted elements
370 while (ll_next(rc) != NULL && cmp_func(ll_data(ll_next(rc)), ll_data(rc)) > 0) {
371 rc = ll_next(rc);
372 rn++;
373 }
374 re = ll_next(rc);
376 // {ls,...,le->prev} and {rs,...,re->prev} are sorted - merge them
377 void *sorted = cx_linked_list_sort_merge(loc_prev, loc_next, loc_data,
378 ln + rn, ls, le, re, cmp_func);
380 // Something left? Sort it!
381 size_t remainder_length = cx_linked_list_size(re, loc_next);
382 if (remainder_length > 0) {
383 void *remainder = re;
384 cx_linked_list_sort(&remainder, NULL, loc_prev, loc_next, loc_data, cmp_func);
386 // merge sorted list with (also sorted) remainder
387 *begin = cx_linked_list_sort_merge(loc_prev, loc_next, loc_data,
388 ln + rn + remainder_length,
389 sorted, remainder, NULL, cmp_func);
390 } else {
391 // no remainder - we've got our sorted list
392 *begin = sorted;
393 }
394 if (end) *end = cx_linked_list_last(sorted, loc_next);
395 }
396 }
398 int cx_linked_list_compare(
399 void const *begin_left,
400 void const *begin_right,
401 ptrdiff_t loc_advance,
402 ptrdiff_t loc_data,
403 CxListComparator cmp_func
404 ) {
405 void const *left = begin_left, *right = begin_right;
407 while (left != NULL && right != NULL) {
408 void const *left_data = ll_data(left);
409 void const *right_data = ll_data(right);
410 int result = cmp_func(left_data, right_data);
411 if (result != 0) return result;
412 left = ll_advance(left);
413 right = ll_advance(right);
414 }
416 if (left != NULL) { return 1; }
417 else if (right != NULL) { return -1; }
418 else { return 0; }
419 }
421 void cx_linked_list_reverse(
422 void **begin,
423 void **end,
424 ptrdiff_t loc_prev,
425 ptrdiff_t loc_next
426 ) {
427 assert(begin != NULL);
428 assert(loc_next >= 0);
430 // swap all links
431 void *prev = NULL;
432 void *cur = *begin;
433 while (cur != NULL) {
434 void *next = ll_next(cur);
436 ll_next(cur) = prev;
437 if (loc_prev >= 0) {
438 ll_prev(cur) = next;
439 }
441 prev = cur;
442 cur = next;
443 }
445 // update begin and end
446 if (end != NULL) {
447 *end = *begin;
448 }
449 *begin = prev;
450 }
452 // HIGH LEVEL LINKED LIST IMPLEMENTATION
454 bool CX_DISABLE_LINKED_LIST_SWAP_SBO = false;
456 typedef struct cx_linked_list_node cx_linked_list_node;
457 struct cx_linked_list_node {
458 cx_linked_list_node *prev;
459 cx_linked_list_node *next;
460 char payload[];
461 };
463 #define CX_LL_LOC_PREV offsetof(cx_linked_list_node, prev)
464 #define CX_LL_LOC_NEXT offsetof(cx_linked_list_node, next)
465 #define CX_LL_LOC_DATA offsetof(cx_linked_list_node, payload)
467 typedef struct {
468 struct cx_list_s base;
469 cx_linked_list_node *begin;
470 cx_linked_list_node *end;
471 } cx_linked_list;
473 static cx_linked_list_node *cx_ll_node_at(
474 cx_linked_list const *list,
475 size_t index
476 ) {
477 if (index >= list->base.size) {
478 return NULL;
479 } else if (index > list->base.size / 2) {
480 return cx_linked_list_at(list->end, list->base.size - 1, CX_LL_LOC_PREV, index);
481 } else {
482 return cx_linked_list_at(list->begin, 0, CX_LL_LOC_NEXT, index);
483 }
484 }
486 static int cx_ll_insert_at(
487 struct cx_list_s *list,
488 cx_linked_list_node *node,
489 void const *elem
490 ) {
492 // create the new new_node
493 cx_linked_list_node *new_node = cxMalloc(list->allocator,
494 sizeof(cx_linked_list_node) + list->itemsize);
496 // sortir if failed
497 if (new_node == NULL) return 1;
499 // initialize new new_node
500 new_node->prev = new_node->next = NULL;
501 memcpy(new_node->payload, elem, list->itemsize);
503 // insert
504 cx_linked_list *ll = (cx_linked_list *) list;
505 cx_linked_list_insert_chain(
506 (void **) &ll->begin, (void **) &ll->end,
507 CX_LL_LOC_PREV, CX_LL_LOC_NEXT,
508 node, new_node, new_node
509 );
511 // increase the size and return
512 list->size++;
513 return 0;
514 }
516 static size_t cx_ll_insert_array(
517 struct cx_list_s *list,
518 size_t index,
519 void const *array,
520 size_t n
521 ) {
522 // out-of bounds and corner case check
523 if (index > list->size || n == 0) return 0;
525 // find position efficiently
526 cx_linked_list_node *node = index == 0 ? NULL : cx_ll_node_at((cx_linked_list *) list, index - 1);
528 // perform first insert
529 if (0 != cx_ll_insert_at(list, node, array)) {
530 return 1;
531 }
533 // is there more?
534 if (n == 1) return 1;
536 // we now know exactly where we are
537 node = node == NULL ? ((cx_linked_list *) list)->begin : node->next;
539 // we can add the remaining nodes and immedately advance to the inserted node
540 char const *source = array;
541 for (size_t i = 1; i < n; i++) {
542 source += list->itemsize;
543 if (0 != cx_ll_insert_at(list, node, source)) {
544 return i;
545 }
546 node = node->next;
547 }
548 return n;
549 }
551 static int cx_ll_insert_element(
552 struct cx_list_s *list,
553 size_t index,
554 void const *element
555 ) {
556 return 1 != cx_ll_insert_array(list, index, element, 1);
557 }
559 static int cx_ll_remove(
560 struct cx_list_s *list,
561 size_t index
562 ) {
563 cx_linked_list *ll = (cx_linked_list *) list;
564 cx_linked_list_node *node = cx_ll_node_at(ll, index);
566 // out-of-bounds check
567 if (node == NULL) return 1;
569 // remove
570 cx_linked_list_remove((void **) &ll->begin, (void **) &ll->end,
571 CX_LL_LOC_PREV, CX_LL_LOC_NEXT, node);
573 // adjust size
574 list->size--;
576 // free and return
577 cxFree(list->allocator, node);
579 return 0;
580 }
582 #ifndef CX_LINKED_LIST_SWAP_SBO_SIZE
583 #define CX_LINKED_LIST_SWAP_SBO_SIZE 16
584 #endif
586 static int cx_ll_swap(
587 struct cx_list_s *list,
588 size_t i,
589 size_t j
590 ) {
591 if (i >= list->size || j >= list->size) return 1;
592 if (i == j) return 0;
594 // perform an optimized search that finds both elements in one run
595 cx_linked_list *ll = (cx_linked_list *) list;
596 size_t mid = list->size / 2;
597 size_t left, right;
598 if (i < j) {
599 left = i;
600 right = j;
601 } else {
602 left = j;
603 right = i;
604 }
605 cx_linked_list_node *nleft, *nright;
606 if (left < mid && right < mid) {
607 // case 1: both items left from mid
608 nleft = cx_ll_node_at(ll, left);
609 nright = nleft;
610 for (size_t c = left; c < right; c++) {
611 nright = nright->next;
612 }
613 } else if (left >= mid && right >= mid) {
614 // case 2: both items right from mid
615 nright = cx_ll_node_at(ll, right);
616 nleft = nright;
617 for (size_t c = right; c > left; c--) {
618 nleft = nleft->prev;
619 }
620 } else {
621 // case 3: one item left, one item right
623 // chose the closest to begin / end
624 size_t closest;
625 size_t other;
626 size_t diff2boundary = list->size - right - 1;
627 if (left <= diff2boundary) {
628 closest = left;
629 other = right;
630 nleft = cx_ll_node_at(ll, left);
631 } else {
632 closest = right;
633 other = left;
634 diff2boundary = left;
635 nright = cx_ll_node_at(ll, right);
636 }
638 // is other element closer to us or closer to boundary?
639 if (right - left <= diff2boundary) {
640 // search other element starting from already found element
641 if (closest == left) {
642 nright = nleft;
643 for (size_t c = left; c < right; c++) {
644 nright = nright->next;
645 }
646 } else {
647 nleft = nright;
648 for (size_t c = right; c > left; c--) {
649 nleft = nleft->prev;
650 }
651 }
652 } else {
653 // search other element starting at the boundary
654 if (closest == left) {
655 nright = cx_ll_node_at(ll, other);
656 } else {
657 nleft = cx_ll_node_at(ll, other);
658 }
659 }
660 }
662 if (list->itemsize > CX_LINKED_LIST_SWAP_SBO_SIZE || CX_DISABLE_LINKED_LIST_SWAP_SBO) {
663 cx_linked_list_node *prev = nleft->prev;
664 cx_linked_list_node *next = nright->next;
665 cx_linked_list_node *midstart = nleft->next;
666 cx_linked_list_node *midend = nright->prev;
668 if (prev == NULL) {
669 ll->begin = nright;
670 } else {
671 prev->next = nright;
672 }
673 nright->prev = prev;
674 if (midstart == nright) {
675 // special case: both nodes are adjacent
676 nright->next = nleft;
677 nleft->prev = nright;
678 } else {
679 // likely case: a chain is between the two nodes
680 nright->next = midstart;
681 midstart->prev = nright;
682 midend->next = nleft;
683 nleft->prev = midend;
684 }
685 nleft->next = next;
686 if (next == NULL) {
687 ll->end = nleft;
688 } else {
689 next->prev = nleft;
690 }
691 } else {
692 // swap payloads to avoid relinking
693 char buf[CX_LINKED_LIST_SWAP_SBO_SIZE];
694 memcpy(buf, nleft->payload, list->itemsize);
695 memcpy(nleft->payload, nright->payload, list->itemsize);
696 memcpy(nright->payload, buf, list->itemsize);
697 }
699 return 0;
700 }
702 static void *cx_ll_at(
703 struct cx_list_s const *list,
704 size_t index
705 ) {
706 cx_linked_list *ll = (cx_linked_list *) list;
707 cx_linked_list_node *node = cx_ll_node_at(ll, index);
708 return node == NULL ? NULL : node->payload;
709 }
711 static size_t cx_ll_find(
712 struct cx_list_s const *list,
713 void const *elem
714 ) {
715 return cx_linked_list_find(((cx_linked_list *) list)->begin,
716 CX_LL_LOC_NEXT, CX_LL_LOC_DATA,
717 list->cmpfunc, elem);
718 }
720 static void cx_ll_sort(struct cx_list_s *list) {
721 cx_linked_list *ll = (cx_linked_list *) list;
722 cx_linked_list_sort((void **) &ll->begin, (void **) &ll->end,
723 CX_LL_LOC_PREV, CX_LL_LOC_NEXT, CX_LL_LOC_DATA,
724 list->cmpfunc);
725 }
727 static void cx_ll_reverse(struct cx_list_s *list) {
728 cx_linked_list *ll = (cx_linked_list *) list;
729 cx_linked_list_reverse((void **) &ll->begin, (void **) &ll->end, CX_LL_LOC_PREV, CX_LL_LOC_NEXT);
730 }
732 static int cx_ll_compare(
733 struct cx_list_s const *list,
734 struct cx_list_s const *other
735 ) {
736 cx_linked_list *left = (cx_linked_list *) list;
737 cx_linked_list *right = (cx_linked_list *) other;
738 return cx_linked_list_compare(left->begin, right->begin,
739 CX_LL_LOC_NEXT, CX_LL_LOC_DATA,
740 list->cmpfunc);
741 }
743 static bool cx_ll_iter_valid(void const *it) {
744 struct cx_iterator_s const *iter = it;
745 return iter->elem_handle != NULL;
746 }
748 static void cx_ll_iter_next(void *it) {
749 struct cx_iterator_base_s *itbase = it;
750 if (itbase->remove) {
751 itbase->remove = false;
752 struct cx_mut_iterator_s *iter = it;
753 cx_linked_list *ll = iter->src_handle;
754 cx_linked_list_node *node = iter->elem_handle;
755 iter->elem_handle = node->next;
756 cx_linked_list_remove((void **) &ll->begin, (void **) &ll->end,
757 CX_LL_LOC_PREV, CX_LL_LOC_NEXT, node);
758 ll->base.size--;
759 cxFree(ll->base.allocator, node);
760 } else {
761 struct cx_iterator_s *iter = it;
762 iter->index++;
763 cx_linked_list_node *node = iter->elem_handle;
764 iter->elem_handle = node->next;
765 }
766 }
768 static void *cx_ll_iter_current(void const *it) {
769 struct cx_iterator_s const *iter = it;
770 cx_linked_list_node *node = iter->elem_handle;
771 return node->payload;
772 }
774 static bool cx_ll_iter_flag_rm(void *it) {
775 struct cx_iterator_base_s *iter = it;
776 if (iter->mutating) {
777 iter->remove = true;
778 return true;
779 } else {
780 return false;
781 }
782 }
784 static CxIterator cx_ll_iterator(
785 struct cx_list_s const *list,
786 size_t index
787 ) {
788 CxIterator iter;
789 iter.index = index;
790 iter.src_handle = list;
791 iter.elem_handle = cx_ll_node_at((cx_linked_list const *) list, index);
792 iter.base.valid = cx_ll_iter_valid;
793 iter.base.current = cx_ll_iter_current;
794 iter.base.next = cx_ll_iter_next;
795 iter.base.flag_removal = cx_ll_iter_flag_rm;
796 iter.base.mutating = false;
797 iter.base.remove = false;
798 return iter;
799 }
801 static int cx_ll_insert_iter(
802 CxMutIterator *iter,
803 void const *elem,
804 int prepend
805 ) {
806 struct cx_list_s *list = iter->src_handle;
807 cx_linked_list_node *node = iter->elem_handle;
808 if (node != NULL) {
809 assert(prepend >= 0 && prepend <= 1);
810 cx_linked_list_node *choice[2] = {node, node->prev};
811 int result = cx_ll_insert_at(list, choice[prepend], elem);
812 iter->index += prepend * (0 == result);
813 return result;
814 } else {
815 int result = cx_ll_insert_element(list, list->size, elem);
816 iter->index = list->size;
817 return result;
818 }
819 }
821 static void cx_ll_destructor(CxList *list) {
822 cx_linked_list *ll = (cx_linked_list *) list;
824 cx_linked_list_node *node = ll->begin;
825 while (node) {
826 void *next = node->next;
827 cxFree(list->allocator, node);
828 node = next;
829 }
830 // do not free the list pointer, this is just a destructor!
831 }
833 static cx_list_class cx_linked_list_class = {
834 cx_ll_destructor,
835 cx_ll_insert_element,
836 cx_ll_insert_array,
837 cx_ll_insert_iter,
838 cx_ll_remove,
839 cx_ll_swap,
840 cx_ll_at,
841 cx_ll_find,
842 cx_ll_sort,
843 cx_ll_compare,
844 cx_ll_reverse,
845 cx_ll_iterator,
846 };
848 CxList *cxLinkedListCreate(
849 CxAllocator const *allocator,
850 CxListComparator comparator,
851 size_t item_size
852 ) {
853 cx_linked_list *list = cxCalloc(allocator, 1, sizeof(cx_linked_list));
854 if (list == NULL) return NULL;
856 list->base.cl = &cx_linked_list_class;
857 list->base.allocator = allocator;
858 list->base.cmpfunc = comparator;
859 list->base.itemsize = item_size;
860 list->base.capacity = SIZE_MAX;
862 return (CxList *) list;
863 }
