src/linked_list.c@d402fead3386
src/linked_list.c
Thu, 26 Jan 2023 20:59:36 +0100
- author
- Mike Becker <universe@uap-core.de>
- date
- Thu, 26 Jan 2023 20:59:36 +0100
- changeset 641
- d402fead3386
- parent 640
- 55cc3b373c5e
- child 647
- 2e6e9d9f2159
- child 650
- 77021e06b1a8
- permissions
- -rw-r--r--
add new pointer list wrapper - resolves #234
since we need a thread local variable, this drops C99 support
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 typedef struct cx_linked_list_node cx_linked_list_node;
455 struct cx_linked_list_node {
456 cx_linked_list_node *prev;
457 cx_linked_list_node *next;
458 char payload[];
459 };
461 #define CX_LL_LOC_PREV offsetof(cx_linked_list_node, prev)
462 #define CX_LL_LOC_NEXT offsetof(cx_linked_list_node, next)
463 #define CX_LL_LOC_DATA offsetof(cx_linked_list_node, payload)
465 typedef struct {
466 struct cx_list_s base;
467 cx_linked_list_node *begin;
468 cx_linked_list_node *end;
469 } cx_linked_list;
471 static cx_linked_list_node *cx_ll_node_at(
472 cx_linked_list const *list,
473 size_t index
474 ) {
475 if (index >= list->base.size) {
476 return NULL;
477 } else if (index > list->base.size / 2) {
478 return cx_linked_list_at(list->end, list->base.size - 1, CX_LL_LOC_PREV, index);
479 } else {
480 return cx_linked_list_at(list->begin, 0, CX_LL_LOC_NEXT, index);
481 }
482 }
484 static int cx_ll_insert_at(
485 struct cx_list_s *list,
486 cx_linked_list_node *node,
487 void const *elem
488 ) {
490 // create the new new_node
491 cx_linked_list_node *new_node = cxMalloc(list->allocator,
492 sizeof(cx_linked_list_node) + list->itemsize);
494 // sortir if failed
495 if (new_node == NULL) return 1;
497 // initialize new new_node
498 new_node->prev = new_node->next = NULL;
499 memcpy(new_node->payload, elem, list->itemsize);
501 // insert
502 cx_linked_list *ll = (cx_linked_list *) list;
503 cx_linked_list_insert_chain(
504 (void **) &ll->begin, (void **) &ll->end,
505 CX_LL_LOC_PREV, CX_LL_LOC_NEXT,
506 node, new_node, new_node
507 );
509 // increase the size and return
510 list->size++;
511 return 0;
512 }
514 static size_t cx_ll_insert_array(
515 struct cx_list_s *list,
516 size_t index,
517 void const *array,
518 size_t n
519 ) {
520 // out-of bounds and corner case check
521 if (index > list->size || n == 0) return 0;
523 // find position efficiently
524 cx_linked_list_node *node = index == 0 ? NULL : cx_ll_node_at((cx_linked_list *) list, index - 1);
526 // perform first insert
527 if (0 != cx_ll_insert_at(list, node, array)) {
528 return 1;
529 }
531 // is there more?
532 if (n == 1) return 1;
534 // we now know exactly where we are
535 node = node == NULL ? ((cx_linked_list *) list)->begin : node->next;
537 // we can add the remaining nodes and immedately advance to the inserted node
538 char const *source = array;
539 for (size_t i = 1; i < n; i++) {
540 source += list->itemsize;
541 if (0 != cx_ll_insert_at(list, node, source)) {
542 return i;
543 }
544 node = node->next;
545 }
546 return n;
547 }
549 static int cx_ll_insert_element(
550 struct cx_list_s *list,
551 size_t index,
552 void const *element
553 ) {
554 return 1 != cx_ll_insert_array(list, index, element, 1);
555 }
557 static int cx_ll_remove(
558 struct cx_list_s *list,
559 size_t index
560 ) {
561 cx_linked_list *ll = (cx_linked_list *) list;
562 cx_linked_list_node *node = cx_ll_node_at(ll, index);
564 // out-of-bounds check
565 if (node == NULL) return 1;
567 // remove
568 cx_linked_list_remove((void **) &ll->begin, (void **) &ll->end,
569 CX_LL_LOC_PREV, CX_LL_LOC_NEXT, node);
571 // adjust size
572 list->size--;
574 // free and return
575 cxFree(list->allocator, node);
577 return 0;
578 }
580 static void *cx_ll_at(
581 struct cx_list_s const *list,
582 size_t index
583 ) {
584 cx_linked_list *ll = (cx_linked_list *) list;
585 cx_linked_list_node *node = cx_ll_node_at(ll, index);
586 return node == NULL ? NULL : node->payload;
587 }
589 static size_t cx_ll_find(
590 struct cx_list_s const *list,
591 void const *elem
592 ) {
593 return cx_linked_list_find(((cx_linked_list *) list)->begin,
594 CX_LL_LOC_NEXT, CX_LL_LOC_DATA,
595 list->cmpfunc, elem);
596 }
598 static void cx_ll_sort(struct cx_list_s *list) {
599 cx_linked_list *ll = (cx_linked_list *) list;
600 cx_linked_list_sort((void **) &ll->begin, (void **) &ll->end,
601 CX_LL_LOC_PREV, CX_LL_LOC_NEXT, CX_LL_LOC_DATA,
602 list->cmpfunc);
603 }
605 static void cx_ll_reverse(struct cx_list_s *list) {
606 cx_linked_list *ll = (cx_linked_list *) list;
607 cx_linked_list_reverse((void **) &ll->begin, (void **) &ll->end, CX_LL_LOC_PREV, CX_LL_LOC_NEXT);
608 }
610 static int cx_ll_compare(
611 struct cx_list_s const *list,
612 struct cx_list_s const *other
613 ) {
614 cx_linked_list *left = (cx_linked_list *) list;
615 cx_linked_list *right = (cx_linked_list *) other;
616 return cx_linked_list_compare(left->begin, right->begin,
617 CX_LL_LOC_NEXT, CX_LL_LOC_DATA,
618 list->cmpfunc);
619 }
621 static bool cx_ll_iter_valid(void const *it) {
622 struct cx_iterator_s const *iter = it;
623 return iter->elem_handle != NULL;
624 }
626 static void cx_ll_iter_next(void *it) {
627 struct cx_iterator_base_s *itbase = it;
628 if (itbase->remove) {
629 itbase->remove = false;
630 struct cx_mut_iterator_s *iter = it;
631 cx_linked_list *ll = iter->src_handle;
632 cx_linked_list_node *node = iter->elem_handle;
633 iter->elem_handle = node->next;
634 cx_linked_list_remove((void **) &ll->begin, (void **) &ll->end,
635 CX_LL_LOC_PREV, CX_LL_LOC_NEXT, node);
636 ll->base.size--;
637 cxFree(ll->base.allocator, node);
638 } else {
639 struct cx_iterator_s *iter = it;
640 iter->index++;
641 cx_linked_list_node *node = iter->elem_handle;
642 iter->elem_handle = node->next;
643 }
644 }
646 static void *cx_ll_iter_current(void const *it) {
647 struct cx_iterator_s const *iter = it;
648 cx_linked_list_node *node = iter->elem_handle;
649 return node->payload;
650 }
652 static bool cx_ll_iter_flag_rm(void *it) {
653 struct cx_iterator_base_s *iter = it;
654 if (iter->mutating) {
655 iter->remove = true;
656 return true;
657 } else {
658 return false;
659 }
660 }
662 static CxIterator cx_ll_iterator(
663 struct cx_list_s const *list,
664 size_t index
665 ) {
666 CxIterator iter;
667 iter.index = index;
668 iter.src_handle = list;
669 iter.elem_handle = cx_ll_node_at((cx_linked_list const *) list, index);
670 iter.base.valid = cx_ll_iter_valid;
671 iter.base.current = cx_ll_iter_current;
672 iter.base.next = cx_ll_iter_next;
673 iter.base.flag_removal = cx_ll_iter_flag_rm;
674 iter.base.mutating = false;
675 iter.base.remove = false;
676 return iter;
677 }
679 static int cx_ll_insert_iter(
680 CxMutIterator *iter,
681 void const *elem,
682 int prepend
683 ) {
684 struct cx_list_s *list = iter->src_handle;
685 cx_linked_list_node *node = iter->elem_handle;
686 if (node != NULL) {
687 assert(prepend >= 0 && prepend <= 1);
688 cx_linked_list_node *choice[2] = {node, node->prev};
689 int result = cx_ll_insert_at(list, choice[prepend], elem);
690 iter->index += prepend * (0 == result);
691 return result;
692 } else {
693 int result = cx_ll_insert_element(list, list->size, elem);
694 iter->index = list->size;
695 return result;
696 }
697 }
699 static void cx_ll_destructor(CxList *list) {
700 cx_linked_list *ll = (cx_linked_list *) list;
702 cx_linked_list_node *node = ll->begin;
703 while (node) {
704 void *next = node->next;
705 cxFree(list->allocator, node);
706 node = next;
707 }
708 // do not free the list pointer, this is just a destructor!
709 }
711 static cx_list_class cx_linked_list_class = {
712 cx_ll_destructor,
713 cx_ll_insert_element,
714 cx_ll_insert_array,
715 cx_ll_insert_iter,
716 cx_ll_remove,
717 cx_ll_at,
718 cx_ll_find,
719 cx_ll_sort,
720 cx_ll_compare,
721 cx_ll_reverse,
722 cx_ll_iterator,
723 };
725 CxList *cxLinkedListCreate(
726 CxAllocator const *allocator,
727 CxListComparator comparator,
728 size_t item_size
729 ) {
730 cx_linked_list *list = cxCalloc(allocator, 1, sizeof(cx_linked_list));
731 if (list == NULL) return NULL;
733 list->base.cl = &cx_linked_list_class;
734 list->base.allocator = allocator;
735 list->base.cmpfunc = comparator;
736 list->base.itemsize = item_size;
737 list->base.capacity = SIZE_MAX;
739 return (CxList *) list;
740 }
