src/linked_list.c@0a71ac9547fd
src/linked_list.c
Thu, 23 Feb 2023 22:27:41 +0100
- author
- Mike Becker <universe@uap-core.de>
- date
- Thu, 23 Feb 2023 22:27:41 +0100
- changeset 661
- 0a71ac9547fd
- parent 655
- 7340c4255f1f
- child 662
- d0d95740071b
- permissions
- -rw-r--r--
add CX_LINKED_LIST_SORT_SBO_SIZE macro
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 <string.h>
32 #include <assert.h>
34 // LOW LEVEL LINKED LIST FUNCTIONS
36 #define CX_LL_PTR(cur, off) (*(void**)(((char*)(cur))+(off)))
37 #define ll_prev(node) CX_LL_PTR(node, loc_prev)
38 #define ll_next(node) CX_LL_PTR(node, loc_next)
39 #define ll_advance(node) CX_LL_PTR(node, loc_advance)
40 #define ll_data(node) (((char*)(node))+loc_data)
42 void *cx_linked_list_at(
43 void const *start,
44 size_t start_index,
45 ptrdiff_t loc_advance,
46 size_t index
47 ) {
48 assert(start != NULL);
49 assert(loc_advance >= 0);
50 size_t i = start_index;
51 void const *cur = start;
52 while (i != index && cur != NULL) {
53 cur = ll_advance(cur);
54 i < index ? i++ : i--;
55 }
56 return (void *) cur;
57 }
59 size_t cx_linked_list_find(
60 void const *start,
61 ptrdiff_t loc_advance,
62 ptrdiff_t loc_data,
63 CxListComparator cmp_func,
64 void const *elem
65 ) {
66 assert(start != NULL);
67 assert(loc_advance >= 0);
68 assert(loc_data >= 0);
69 assert(cmp_func);
71 void const *node = start;
72 size_t index = 0;
73 do {
74 void *current = ll_data(node);
75 if (cmp_func(current, elem) == 0) {
76 return index;
77 }
78 node = ll_advance(node);
79 index++;
80 } while (node != NULL);
81 return index;
82 }
84 void *cx_linked_list_first(
85 void const *node,
86 ptrdiff_t loc_prev
87 ) {
88 return cx_linked_list_last(node, loc_prev);
89 }
91 void *cx_linked_list_last(
92 void const *node,
93 ptrdiff_t loc_next
94 ) {
95 assert(node != NULL);
96 assert(loc_next >= 0);
98 void const *cur = node;
99 void const *last;
100 do {
101 last = cur;
102 } while ((cur = ll_next(cur)) != NULL);
104 return (void *) last;
105 }
107 void *cx_linked_list_prev(
108 void const *begin,
109 ptrdiff_t loc_next,
110 void const *node
111 ) {
112 assert(begin != NULL);
113 assert(node != NULL);
114 assert(loc_next >= 0);
115 if (begin == node) return NULL;
116 void const *cur = begin;
117 void const *next;
118 while (1) {
119 next = ll_next(cur);
120 if (next == node) return (void *) cur;
121 cur = next;
122 }
123 }
125 void cx_linked_list_link(
126 void *left,
127 void *right,
128 ptrdiff_t loc_prev,
129 ptrdiff_t loc_next
130 ) {
131 assert(loc_next >= 0);
132 ll_next(left) = right;
133 if (loc_prev >= 0) {
134 ll_prev(right) = left;
135 }
136 }
138 void cx_linked_list_unlink(
139 void *left,
140 void *right,
141 ptrdiff_t loc_prev,
142 ptrdiff_t loc_next
143 ) {
144 assert (loc_next >= 0);
145 assert(ll_next(left) == right);
146 ll_next(left) = NULL;
147 if (loc_prev >= 0) {
148 assert(ll_prev(right) == left);
149 ll_prev(right) = NULL;
150 }
151 }
153 void cx_linked_list_add(
154 void **begin,
155 void **end,
156 ptrdiff_t loc_prev,
157 ptrdiff_t loc_next,
158 void *new_node
159 ) {
160 void *last;
161 if (end == NULL) {
162 assert(begin != NULL);
163 last = *begin == NULL ? NULL : cx_linked_list_last(*begin, loc_next);
164 } else {
165 last = *end;
166 }
167 cx_linked_list_insert_chain(begin, end, loc_prev, loc_next, last, new_node, new_node);
168 }
170 void cx_linked_list_prepend(
171 void **begin,
172 void **end,
173 ptrdiff_t loc_prev,
174 ptrdiff_t loc_next,
175 void *new_node
176 ) {
177 cx_linked_list_insert_chain(begin, end, loc_prev, loc_next, NULL, new_node, new_node);
178 }
180 void cx_linked_list_insert(
181 void **begin,
182 void **end,
183 ptrdiff_t loc_prev,
184 ptrdiff_t loc_next,
185 void *node,
186 void *new_node
187 ) {
188 cx_linked_list_insert_chain(begin, end, loc_prev, loc_next, node, new_node, new_node);
189 }
191 void cx_linked_list_insert_chain(
192 void **begin,
193 void **end,
194 ptrdiff_t loc_prev,
195 ptrdiff_t loc_next,
196 void *node,
197 void *insert_begin,
198 void *insert_end
199 ) {
200 // find the end of the chain, if not specified
201 if (insert_end == NULL) {
202 insert_end = cx_linked_list_last(insert_begin, loc_next);
203 }
205 // determine the successor
206 void *successor;
207 if (node == NULL) {
208 assert(begin != NULL || (end != NULL && loc_prev >= 0));
209 if (begin != NULL) {
210 successor = *begin;
211 *begin = insert_begin;
212 } else {
213 successor = *end == NULL ? NULL : cx_linked_list_first(*end, loc_prev);
214 }
215 } else {
216 successor = ll_next(node);
217 cx_linked_list_link(node, insert_begin, loc_prev, loc_next);
218 }
220 if (successor == NULL) {
221 // the list ends with the new chain
222 if (end != NULL) {
223 *end = insert_end;
224 }
225 } else {
226 cx_linked_list_link(insert_end, successor, loc_prev, loc_next);
227 }
228 }
230 void cx_linked_list_remove(
231 void **begin,
232 void **end,
233 ptrdiff_t loc_prev,
234 ptrdiff_t loc_next,
235 void *node
236 ) {
237 assert(node != NULL);
238 assert(loc_next >= 0);
239 assert(loc_prev >= 0 || begin != NULL);
241 // find adjacent nodes
242 void *next = ll_next(node);
243 void *prev;
244 if (loc_prev >= 0) {
245 prev = ll_prev(node);
246 } else {
247 prev = cx_linked_list_prev(*begin, loc_next, node);
248 }
250 // update next pointer of prev node, or set begin
251 if (prev == NULL) {
252 if (begin != NULL) {
253 *begin = next;
254 }
255 } else {
256 ll_next(prev) = next;
257 }
259 // update prev pointer of next node, or set end
260 if (next == NULL) {
261 if (end != NULL) {
262 *end = prev;
263 }
264 } else if (loc_prev >= 0) {
265 ll_prev(next) = prev;
266 }
267 }
269 size_t cx_linked_list_size(
270 void const *node,
271 ptrdiff_t loc_next
272 ) {
273 assert(loc_next >= 0);
274 size_t size = 0;
275 while (node != NULL) {
276 node = ll_next(node);
277 size++;
278 }
279 return size;
280 }
282 #ifndef CX_LINKED_LIST_SORT_SBO_SIZE
283 #define CX_LINKED_LIST_SORT_SBO_SIZE 1024
284 #endif
286 static void *cx_linked_list_sort_merge(
287 ptrdiff_t loc_prev,
288 ptrdiff_t loc_next,
289 ptrdiff_t loc_data,
290 size_t length,
291 void *ls,
292 void *le,
293 void *re,
294 CxListComparator cmp_func
295 ) {
296 void *sbo[CX_LINKED_LIST_SORT_SBO_SIZE];
297 void **sorted = length >= CX_LINKED_LIST_SORT_SBO_SIZE ?
298 malloc(sizeof(void *) * length) : sbo;
299 if (sorted == NULL) abort();
300 void *rc, *lc;
302 lc = ls;
303 rc = le;
304 size_t n = 0;
305 while (lc && lc != le && rc != re) {
306 if (cmp_func(ll_data(lc), ll_data(rc)) <= 0) {
307 sorted[n] = lc;
308 lc = ll_next(lc);
309 } else {
310 sorted[n] = rc;
311 rc = ll_next(rc);
312 }
313 n++;
314 }
315 while (lc && lc != le) {
316 sorted[n] = lc;
317 lc = ll_next(lc);
318 n++;
319 }
320 while (rc && rc != re) {
321 sorted[n] = rc;
322 rc = ll_next(rc);
323 n++;
324 }
326 // Update pointer
327 if (loc_prev >= 0) ll_prev(sorted[0]) = NULL;
328 cx_for_n (i, length - 1) {
329 cx_linked_list_link(sorted[i], sorted[i + 1], loc_prev, loc_next);
330 }
331 ll_next(sorted[length - 1]) = NULL;
333 void *ret = sorted[0];
334 if (sorted != sbo) {
335 free(sorted);
336 }
337 return ret;
338 }
340 void cx_linked_list_sort( // NOLINT(misc-no-recursion) - purposely recursive function
341 void **begin,
342 void **end,
343 ptrdiff_t loc_prev,
344 ptrdiff_t loc_next,
345 ptrdiff_t loc_data,
346 CxListComparator cmp_func
347 ) {
348 assert(begin != NULL);
349 assert(loc_next >= 0);
350 assert(loc_data >= 0);
351 assert(cmp_func);
353 void *lc, *ls, *le, *re;
355 // set start node
356 ls = *begin;
358 // check how many elements are already sorted
359 lc = ls;
360 size_t ln = 1;
361 while (ll_next(lc) != NULL && cmp_func(ll_data(ll_next(lc)), ll_data(lc)) > 0) {
362 lc = ll_next(lc);
363 ln++;
364 }
365 le = ll_next(lc);
367 // if first unsorted node is NULL, the list is already completely sorted
368 if (le != NULL) {
369 void *rc;
370 size_t rn = 1;
371 rc = le;
372 // skip already sorted elements
373 while (ll_next(rc) != NULL && cmp_func(ll_data(ll_next(rc)), ll_data(rc)) > 0) {
374 rc = ll_next(rc);
375 rn++;
376 }
377 re = ll_next(rc);
379 // {ls,...,le->prev} and {rs,...,re->prev} are sorted - merge them
380 void *sorted = cx_linked_list_sort_merge(loc_prev, loc_next, loc_data,
381 ln + rn, ls, le, re, cmp_func);
383 // Something left? Sort it!
384 size_t remainder_length = cx_linked_list_size(re, loc_next);
385 if (remainder_length > 0) {
386 void *remainder = re;
387 cx_linked_list_sort(&remainder, NULL, loc_prev, loc_next, loc_data, cmp_func);
389 // merge sorted list with (also sorted) remainder
390 *begin = cx_linked_list_sort_merge(loc_prev, loc_next, loc_data,
391 ln + rn + remainder_length,
392 sorted, remainder, NULL, cmp_func);
393 } else {
394 // no remainder - we've got our sorted list
395 *begin = sorted;
396 }
397 if (end) *end = cx_linked_list_last(sorted, loc_next);
398 }
399 }
401 int cx_linked_list_compare(
402 void const *begin_left,
403 void const *begin_right,
404 ptrdiff_t loc_advance,
405 ptrdiff_t loc_data,
406 CxListComparator cmp_func
407 ) {
408 void const *left = begin_left, *right = begin_right;
410 while (left != NULL && right != NULL) {
411 void const *left_data = ll_data(left);
412 void const *right_data = ll_data(right);
413 int result = cmp_func(left_data, right_data);
414 if (result != 0) return result;
415 left = ll_advance(left);
416 right = ll_advance(right);
417 }
419 if (left != NULL) { return 1; }
420 else if (right != NULL) { return -1; }
421 else { return 0; }
422 }
424 void cx_linked_list_reverse(
425 void **begin,
426 void **end,
427 ptrdiff_t loc_prev,
428 ptrdiff_t loc_next
429 ) {
430 assert(begin != NULL);
431 assert(loc_next >= 0);
433 // swap all links
434 void *prev = NULL;
435 void *cur = *begin;
436 while (cur != NULL) {
437 void *next = ll_next(cur);
439 ll_next(cur) = prev;
440 if (loc_prev >= 0) {
441 ll_prev(cur) = next;
442 }
444 prev = cur;
445 cur = next;
446 }
448 // update begin and end
449 if (end != NULL) {
450 *end = *begin;
451 }
452 *begin = prev;
453 }
455 // HIGH LEVEL LINKED LIST IMPLEMENTATION
457 bool CX_DISABLE_LINKED_LIST_SWAP_SBO = false;
459 typedef struct cx_linked_list_node cx_linked_list_node;
460 struct cx_linked_list_node {
461 cx_linked_list_node *prev;
462 cx_linked_list_node *next;
463 char payload[];
464 };
466 #define CX_LL_LOC_PREV offsetof(cx_linked_list_node, prev)
467 #define CX_LL_LOC_NEXT offsetof(cx_linked_list_node, next)
468 #define CX_LL_LOC_DATA offsetof(cx_linked_list_node, payload)
470 typedef struct {
471 struct cx_list_s base;
472 cx_linked_list_node *begin;
473 cx_linked_list_node *end;
474 } cx_linked_list;
476 static cx_linked_list_node *cx_ll_node_at(
477 cx_linked_list const *list,
478 size_t index
479 ) {
480 if (index >= list->base.size) {
481 return NULL;
482 } else if (index > list->base.size / 2) {
483 return cx_linked_list_at(list->end, list->base.size - 1, CX_LL_LOC_PREV, index);
484 } else {
485 return cx_linked_list_at(list->begin, 0, CX_LL_LOC_NEXT, index);
486 }
487 }
489 static int cx_ll_insert_at(
490 struct cx_list_s *list,
491 cx_linked_list_node *node,
492 void const *elem
493 ) {
495 // create the new new_node
496 cx_linked_list_node *new_node = cxMalloc(list->allocator,
497 sizeof(cx_linked_list_node) + list->itemsize);
499 // sortir if failed
500 if (new_node == NULL) return 1;
502 // initialize new new_node
503 new_node->prev = new_node->next = NULL;
504 memcpy(new_node->payload, elem, list->itemsize);
506 // insert
507 cx_linked_list *ll = (cx_linked_list *) list;
508 cx_linked_list_insert_chain(
509 (void **) &ll->begin, (void **) &ll->end,
510 CX_LL_LOC_PREV, CX_LL_LOC_NEXT,
511 node, new_node, new_node
512 );
514 // increase the size and return
515 list->size++;
516 return 0;
517 }
519 static size_t cx_ll_insert_array(
520 struct cx_list_s *list,
521 size_t index,
522 void const *array,
523 size_t n
524 ) {
525 // out-of bounds and corner case check
526 if (index > list->size || n == 0) return 0;
528 // find position efficiently
529 cx_linked_list_node *node = index == 0 ? NULL : cx_ll_node_at((cx_linked_list *) list, index - 1);
531 // perform first insert
532 if (0 != cx_ll_insert_at(list, node, array)) {
533 return 1;
534 }
536 // is there more?
537 if (n == 1) return 1;
539 // we now know exactly where we are
540 node = node == NULL ? ((cx_linked_list *) list)->begin : node->next;
542 // we can add the remaining nodes and immedately advance to the inserted node
543 char const *source = array;
544 for (size_t i = 1; i < n; i++) {
545 source += list->itemsize;
546 if (0 != cx_ll_insert_at(list, node, source)) {
547 return i;
548 }
549 node = node->next;
550 }
551 return n;
552 }
554 static int cx_ll_insert_element(
555 struct cx_list_s *list,
556 size_t index,
557 void const *element
558 ) {
559 return 1 != cx_ll_insert_array(list, index, element, 1);
560 }
562 static int cx_ll_remove(
563 struct cx_list_s *list,
564 size_t index
565 ) {
566 cx_linked_list *ll = (cx_linked_list *) list;
567 cx_linked_list_node *node = cx_ll_node_at(ll, index);
569 // out-of-bounds check
570 if (node == NULL) return 1;
572 // remove
573 cx_linked_list_remove((void **) &ll->begin, (void **) &ll->end,
574 CX_LL_LOC_PREV, CX_LL_LOC_NEXT, node);
576 // adjust size
577 list->size--;
579 // free and return
580 cxFree(list->allocator, node);
582 return 0;
583 }
585 #ifndef CX_LINKED_LIST_SWAP_SBO_SIZE
586 #define CX_LINKED_LIST_SWAP_SBO_SIZE 16
587 #endif
589 static int cx_ll_swap(
590 struct cx_list_s *list,
591 size_t i,
592 size_t j
593 ) {
594 if (i >= list->size || j >= list->size) return 1;
595 if (i == j) return 0;
597 // perform an optimized search that finds both elements in one run
598 cx_linked_list *ll = (cx_linked_list *) list;
599 size_t mid = list->size / 2;
600 size_t left, right;
601 if (i < j) {
602 left = i;
603 right = j;
604 } else {
605 left = j;
606 right = i;
607 }
608 cx_linked_list_node *nleft, *nright;
609 if (left < mid && right < mid) {
610 // case 1: both items left from mid
611 nleft = cx_ll_node_at(ll, left);
612 nright = nleft;
613 for (size_t c = left; c < right; c++) {
614 nright = nright->next;
615 }
616 } else if (left >= mid && right >= mid) {
617 // case 2: both items right from mid
618 nright = cx_ll_node_at(ll, right);
619 nleft = nright;
620 for (size_t c = right; c > left; c--) {
621 nleft = nleft->prev;
622 }
623 } else {
624 // case 3: one item left, one item right
626 // chose the closest to begin / end
627 size_t closest;
628 size_t other;
629 size_t diff2boundary = list->size - right - 1;
630 if (left <= diff2boundary) {
631 closest = left;
632 other = right;
633 nleft = cx_ll_node_at(ll, left);
634 } else {
635 closest = right;
636 other = left;
637 diff2boundary = left;
638 nright = cx_ll_node_at(ll, right);
639 }
641 // is other element closer to us or closer to boundary?
642 if (right - left <= diff2boundary) {
643 // search other element starting from already found element
644 if (closest == left) {
645 nright = nleft;
646 for (size_t c = left; c < right; c++) {
647 nright = nright->next;
648 }
649 } else {
650 nleft = nright;
651 for (size_t c = right; c > left; c--) {
652 nleft = nleft->prev;
653 }
654 }
655 } else {
656 // search other element starting at the boundary
657 if (closest == left) {
658 nright = cx_ll_node_at(ll, other);
659 } else {
660 nleft = cx_ll_node_at(ll, other);
661 }
662 }
663 }
665 if (list->itemsize > CX_LINKED_LIST_SWAP_SBO_SIZE || CX_DISABLE_LINKED_LIST_SWAP_SBO) {
666 cx_linked_list_node *prev = nleft->prev;
667 cx_linked_list_node *next = nright->next;
668 cx_linked_list_node *midstart = nleft->next;
669 cx_linked_list_node *midend = nright->prev;
671 if (prev == NULL) {
672 ll->begin = nright;
673 } else {
674 prev->next = nright;
675 }
676 nright->prev = prev;
677 if (midstart == nright) {
678 // special case: both nodes are adjacent
679 nright->next = nleft;
680 nleft->prev = nright;
681 } else {
682 // likely case: a chain is between the two nodes
683 nright->next = midstart;
684 midstart->prev = nright;
685 midend->next = nleft;
686 nleft->prev = midend;
687 }
688 nleft->next = next;
689 if (next == NULL) {
690 ll->end = nleft;
691 } else {
692 next->prev = nleft;
693 }
694 } else {
695 // swap payloads to avoid relinking
696 char buf[CX_LINKED_LIST_SWAP_SBO_SIZE];
697 memcpy(buf, nleft->payload, list->itemsize);
698 memcpy(nleft->payload, nright->payload, list->itemsize);
699 memcpy(nright->payload, buf, list->itemsize);
700 }
702 return 0;
703 }
705 static void *cx_ll_at(
706 struct cx_list_s const *list,
707 size_t index
708 ) {
709 cx_linked_list *ll = (cx_linked_list *) list;
710 cx_linked_list_node *node = cx_ll_node_at(ll, index);
711 return node == NULL ? NULL : node->payload;
712 }
714 static size_t cx_ll_find(
715 struct cx_list_s const *list,
716 void const *elem
717 ) {
718 return cx_linked_list_find(((cx_linked_list *) list)->begin,
719 CX_LL_LOC_NEXT, CX_LL_LOC_DATA,
720 list->cmpfunc, elem);
721 }
723 static void cx_ll_sort(struct cx_list_s *list) {
724 cx_linked_list *ll = (cx_linked_list *) list;
725 cx_linked_list_sort((void **) &ll->begin, (void **) &ll->end,
726 CX_LL_LOC_PREV, CX_LL_LOC_NEXT, CX_LL_LOC_DATA,
727 list->cmpfunc);
728 }
730 static void cx_ll_reverse(struct cx_list_s *list) {
731 cx_linked_list *ll = (cx_linked_list *) list;
732 cx_linked_list_reverse((void **) &ll->begin, (void **) &ll->end, CX_LL_LOC_PREV, CX_LL_LOC_NEXT);
733 }
735 static int cx_ll_compare(
736 struct cx_list_s const *list,
737 struct cx_list_s const *other
738 ) {
739 cx_linked_list *left = (cx_linked_list *) list;
740 cx_linked_list *right = (cx_linked_list *) other;
741 return cx_linked_list_compare(left->begin, right->begin,
742 CX_LL_LOC_NEXT, CX_LL_LOC_DATA,
743 list->cmpfunc);
744 }
746 static bool cx_ll_iter_valid(void const *it) {
747 struct cx_iterator_s const *iter = it;
748 return iter->elem_handle != NULL;
749 }
751 static void cx_ll_iter_next(void *it) {
752 struct cx_iterator_base_s *itbase = it;
753 if (itbase->remove) {
754 itbase->remove = false;
755 struct cx_mut_iterator_s *iter = it;
756 cx_linked_list *ll = iter->src_handle;
757 cx_linked_list_node *node = iter->elem_handle;
758 iter->elem_handle = node->next;
759 cx_linked_list_remove((void **) &ll->begin, (void **) &ll->end,
760 CX_LL_LOC_PREV, CX_LL_LOC_NEXT, node);
761 ll->base.size--;
762 cxFree(ll->base.allocator, node);
763 } else {
764 struct cx_iterator_s *iter = it;
765 iter->index++;
766 cx_linked_list_node *node = iter->elem_handle;
767 iter->elem_handle = node->next;
768 }
769 }
771 static void cx_ll_iter_prev(void *it) {
772 struct cx_iterator_base_s *itbase = it;
773 if (itbase->remove) {
774 itbase->remove = false;
775 struct cx_mut_iterator_s *iter = it;
776 cx_linked_list *ll = iter->src_handle;
777 cx_linked_list_node *node = iter->elem_handle;
778 iter->elem_handle = node->prev;
779 iter->index--;
780 cx_linked_list_remove((void **) &ll->begin, (void **) &ll->end,
781 CX_LL_LOC_PREV, CX_LL_LOC_NEXT, node);
782 ll->base.size--;
783 cxFree(ll->base.allocator, node);
784 } else {
785 struct cx_iterator_s *iter = it;
786 iter->index--;
787 cx_linked_list_node *node = iter->elem_handle;
788 iter->elem_handle = node->prev;
789 }
790 }
792 static void *cx_ll_iter_current(void const *it) {
793 struct cx_iterator_s const *iter = it;
794 cx_linked_list_node *node = iter->elem_handle;
795 return node->payload;
796 }
798 static bool cx_ll_iter_flag_rm(void *it) {
799 struct cx_iterator_base_s *iter = it;
800 if (iter->mutating) {
801 iter->remove = true;
802 return true;
803 } else {
804 return false;
805 }
806 }
808 static CxIterator cx_ll_iterator(
809 struct cx_list_s const *list,
810 size_t index,
811 bool backwards
812 ) {
813 CxIterator iter;
814 iter.index = index;
815 iter.src_handle = list;
816 iter.elem_handle = cx_ll_node_at((cx_linked_list const *) list, index);
817 iter.base.valid = cx_ll_iter_valid;
818 iter.base.current = cx_ll_iter_current;
819 iter.base.next = backwards ? cx_ll_iter_prev : cx_ll_iter_next;
820 iter.base.flag_removal = cx_ll_iter_flag_rm;
821 iter.base.mutating = false;
822 iter.base.remove = false;
823 return iter;
824 }
826 static int cx_ll_insert_iter(
827 CxMutIterator *iter,
828 void const *elem,
829 int prepend
830 ) {
831 struct cx_list_s *list = iter->src_handle;
832 cx_linked_list_node *node = iter->elem_handle;
833 if (node != NULL) {
834 assert(prepend >= 0 && prepend <= 1);
835 cx_linked_list_node *choice[2] = {node, node->prev};
836 int result = cx_ll_insert_at(list, choice[prepend], elem);
837 iter->index += prepend * (0 == result);
838 return result;
839 } else {
840 int result = cx_ll_insert_element(list, list->size, elem);
841 iter->index = list->size;
842 return result;
843 }
844 }
846 static void cx_ll_destructor(CxList *list) {
847 cx_linked_list *ll = (cx_linked_list *) list;
849 cx_linked_list_node *node = ll->begin;
850 while (node) {
851 void *next = node->next;
852 cxFree(list->allocator, node);
853 node = next;
854 }
855 // do not free the list pointer, this is just a destructor!
856 }
858 static cx_list_class cx_linked_list_class = {
859 cx_ll_destructor,
860 cx_ll_insert_element,
861 cx_ll_insert_array,
862 cx_ll_insert_iter,
863 cx_ll_remove,
864 cx_ll_swap,
865 cx_ll_at,
866 cx_ll_find,
867 cx_ll_sort,
868 cx_ll_compare,
869 cx_ll_reverse,
870 cx_ll_iterator,
871 };
873 CxList *cxLinkedListCreate(
874 CxAllocator const *allocator,
875 CxListComparator comparator,
876 size_t item_size
877 ) {
878 cx_linked_list *list = cxCalloc(allocator, 1, sizeof(cx_linked_list));
879 if (list == NULL) return NULL;
881 list->base.cl = &cx_linked_list_class;
882 list->base.allocator = allocator;
883 list->base.cmpfunc = comparator;
884 list->base.itemsize = item_size;
885 list->base.capacity = SIZE_MAX;
887 return (CxList *) list;
888 }
