Thu, 23 Dec 2021 15:20:50 +0100
add several new linked list functions
* cx_linked_list_insert()
* cx_linked_list_insert_chain()
* cx_linked_list_link()
* cx_linked_list_unlink()
Also uses the most general function wherever possible.
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 <stdint.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) (follow_ptr?CX_LL_PTR(node, loc_data):(((char*)node)+loc_data))
42 void *cx_linked_list_at(
43 void *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 *cur = start;
52 while (i != index && cur != NULL) {
53 cur = ll_advance(cur);
54 i < index ? i++ : i--;
55 }
56 return cur;
57 }
59 size_t cx_linked_list_find(
60 void *start,
61 ptrdiff_t loc_advance,
62 ptrdiff_t loc_data,
63 int follow_ptr,
64 CxListComparator cmp_func,
65 void *elem
66 ) {
67 assert(start != NULL);
68 assert(loc_advance >= 0);
69 assert(loc_data >= 0);
70 assert(cmp_func);
72 void *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 *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 *node,
94 ptrdiff_t loc_next
95 ) {
96 assert(node != NULL);
97 assert(loc_next >= 0);
99 void *cur = node;
100 void *last;
101 do {
102 last = cur;
103 } while ((cur = ll_next(cur)) != NULL);
105 return last;
106 }
108 void *cx_linked_list_prev(
109 void *begin,
110 ptrdiff_t loc_next,
111 void *node
112 ) {
113 assert(begin != NULL);
114 assert(node != NULL);
115 assert(loc_next >= 0);
116 if (begin == node) return NULL;
117 void *cur = begin;
118 void *next;
119 while (1) {
120 next = ll_next(cur);
121 if (next == node) return 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 *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 int follow_ptr,
288 size_t length,
289 void *ls,
290 void *le,
291 void *re,
292 CxListComparator cmp_func
293 ) {
294 const size_t sbo_len = 1024;
295 void *sbo[sbo_len];
296 void **sorted = (length >= sbo_len) ? malloc(sizeof(void *) * length) : sbo;
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 for (size_t i = 0; i < length - 1; i++) {
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 int follow_ptr,
344 CxListComparator cmp_func
345 ) {
346 assert(begin != NULL);
347 assert(loc_next >= 0);
348 assert(loc_data >= 0);
349 assert(cmp_func);
351 void *lc, *ls, *le, *re;
353 // set start node
354 ls = *begin;
356 // check how many elements are already sorted
357 lc = ls;
358 size_t ln = 1;
359 while (ll_next(lc) != NULL && cmp_func(ll_data(ll_next(lc)), ll_data(lc)) > 0) {
360 lc = ll_next(lc);
361 ln++;
362 }
363 le = ll_next(lc);
365 // if first unsorted node is NULL, the list is already completely sorted
366 if (le != NULL) {
367 void *rc;
368 size_t rn = 1;
369 rc = le;
370 // skip already sorted elements
371 while (ll_next(rc) != NULL && cmp_func(ll_data(ll_next(rc)), ll_data(rc)) > 0) {
372 rc = ll_next(rc);
373 rn++;
374 }
375 re = ll_next(rc);
377 // {ls,...,le->prev} and {rs,...,re->prev} are sorted - merge them
378 void *sorted = cx_linked_list_sort_merge(loc_prev, loc_next, loc_data, follow_ptr,
379 ln + rn, ls, le, re, cmp_func);
381 // Something left? Sort it!
382 size_t remainder_length = cx_linked_list_size(re, loc_next);
383 if (remainder_length > 0) {
384 void *remainder = re;
385 cx_linked_list_sort(&remainder, NULL, loc_prev, loc_next, loc_data, follow_ptr, cmp_func);
387 // merge sorted list with (also sorted) remainder
388 *begin = cx_linked_list_sort_merge(loc_prev, loc_next, loc_data, follow_ptr,
389 ln + rn + remainder_length,
390 sorted, remainder, NULL, cmp_func);
391 } else {
392 // no remainder - we've got our sorted list
393 *begin = sorted;
394 }
395 if (end) *end = cx_linked_list_last(sorted, loc_next);
396 }
397 }
399 void cx_linked_list_reverse(
400 void **begin,
401 void **end,
402 ptrdiff_t loc_prev,
403 ptrdiff_t loc_next
404 ) {
405 assert(begin != NULL);
406 assert(loc_next >= 0);
408 // swap all links
409 void *prev = NULL;
410 void *cur = *begin;
411 while (cur != NULL) {
412 void *next = ll_next(cur);
414 ll_next(cur) = prev;
415 if (loc_prev >= 0) {
416 ll_prev(cur) = next;
417 }
419 prev = cur;
420 cur = next;
421 }
423 // update begin and end
424 if (end != NULL) {
425 *end = *begin;
426 }
427 *begin = prev;
428 }
430 /* HIGH LEVEL LINKED LIST IMPLEMENTATION */
432 typedef struct cx_linked_list_node cx_linked_list_node;
433 struct cx_linked_list_node {
434 cx_linked_list_node *prev;
435 cx_linked_list_node *next;
436 char payload[];
437 };
439 #define CX_LL_LOC_PREV offsetof(cx_linked_list_node, prev)
440 #define CX_LL_LOC_NEXT offsetof(cx_linked_list_node, next)
441 #define CX_LL_LOC_DATA offsetof(cx_linked_list_node, payload)
443 typedef struct {
444 cx_list_s base;
445 cx_linked_list_node *begin;
446 cx_linked_list_node *end;
447 } cx_linked_list;
449 static cx_linked_list_node *cx_ll_node_at(
450 cx_linked_list *list,
451 size_t index
452 ) {
453 if (index >= list->base.size) {
454 return NULL;
455 } else if (index > list->base.size / 2) {
456 return cx_linked_list_at(list->end, list->base.size - 1, CX_LL_LOC_PREV, index);
457 } else {
458 return cx_linked_list_at(list->begin, 0, CX_LL_LOC_NEXT, index);
459 }
460 }
462 static int cx_ll_insert(
463 cx_list_s *list,
464 size_t index,
465 void *elem
466 ) {
467 // out-of bounds check
468 if (index > list->size) return 1;
470 // cast a linked list pointer
471 cx_linked_list *ll = (cx_linked_list *) list;
473 // create the new new_node
474 cx_linked_list_node *new_node = cxMalloc(list->allocator,
475 sizeof(cx_linked_list_node) + list->itemsize);
477 // sortir if failed
478 if (new_node == NULL) return 1;
480 // initialize new new_node
481 new_node->prev = new_node->next = NULL;
482 memcpy(new_node->payload, elem, list->itemsize);
484 // find position efficiently
485 cx_linked_list_node *node = index == 0 ? NULL : cx_ll_node_at(ll, index - 1);
487 // insert
488 cx_linked_list_insert_chain(
489 (void **) &ll->begin, (void **) &ll->end,
490 CX_LL_LOC_PREV, CX_LL_LOC_NEXT,
491 node, new_node, new_node
492 );
494 // increase the size and return
495 list->size++;
496 return 0;
497 }
499 static int cx_ll_add(
500 cx_list_s *list,
501 void *elem
502 ) {
503 return cx_ll_insert(list, list->size, elem);
504 }
506 static int cx_pll_insert(
507 cx_list_s *list,
508 size_t index,
509 void *elem
510 ) {
511 return cx_ll_insert(list, index, &elem);
512 }
514 static int cx_pll_add(
515 cx_list_s *list,
516 void *elem
517 ) {
518 return cx_ll_insert(list, list->size, &elem);
519 }
521 static int cx_ll_remove(
522 cx_list_s *list,
523 size_t index
524 ) {
525 cx_linked_list *ll = (cx_linked_list *) list;
526 cx_linked_list_node *node = cx_ll_node_at(ll, index);
528 // out-of-bounds check
529 if (node == NULL) return 1;
531 // remove
532 cx_linked_list_remove((void **) &ll->begin, (void **) &ll->end,
533 CX_LL_LOC_PREV, CX_LL_LOC_NEXT, node);
535 // adjust size
536 list->size--;
538 // free and return
539 cxFree(list->allocator, node);
541 return 0;
542 }
544 static void *cx_ll_at(
545 cx_list_s *list,
546 size_t index
547 ) {
548 cx_linked_list *ll = (cx_linked_list *) list;
549 cx_linked_list_node *node = cx_ll_node_at(ll, index);
550 return node == NULL ? NULL : node->payload;
551 }
553 static void *cx_pll_at(
554 cx_list_s *list,
555 size_t index
556 ) {
557 cx_linked_list *ll = (cx_linked_list *) list;
558 cx_linked_list_node *node = cx_ll_node_at(ll, index);
559 return node == NULL ? NULL : *(void **) node->payload;
560 }
562 static size_t cx_ll_find(
563 cx_list_s *list,
564 void *elem
565 ) {
566 return cx_linked_list_find(((cx_linked_list *) list)->begin,
567 CX_LL_LOC_NEXT, CX_LL_LOC_DATA,
568 0, list->cmpfunc, elem);
569 }
571 static size_t cx_pll_find(
572 cx_list_s *list,
573 void *elem
574 ) {
575 return cx_linked_list_find(((cx_linked_list *) list)->begin,
576 CX_LL_LOC_NEXT, CX_LL_LOC_DATA,
577 1, list->cmpfunc, elem);
578 }
580 static void cx_ll_sort(cx_list_s *list) {
581 cx_linked_list *ll = (cx_linked_list *) list;
582 cx_linked_list_sort((void **) &ll->begin, (void **) &ll->end,
583 CX_LL_LOC_PREV, CX_LL_LOC_NEXT, CX_LL_LOC_DATA,
584 0, list->cmpfunc);
585 }
587 static void cx_pll_sort(cx_list_s *list) {
588 cx_linked_list *ll = (cx_linked_list *) list;
589 cx_linked_list_sort((void **) &ll->begin, (void **) &ll->end,
590 CX_LL_LOC_PREV, CX_LL_LOC_NEXT, CX_LL_LOC_DATA,
591 1, list->cmpfunc);
592 }
594 static cx_list_class cx_linked_list_class = {
595 cx_ll_add,
596 cx_ll_insert,
597 cx_ll_remove,
598 cx_ll_at,
599 cx_ll_find,
600 cx_ll_sort
601 };
603 static cx_list_class cx_pointer_linked_list_class = {
604 cx_pll_add,
605 cx_pll_insert,
606 cx_ll_remove,
607 cx_pll_at,
608 cx_pll_find,
609 cx_pll_sort
610 };
612 CxList cxLinkedListCreate(
613 CxAllocator allocator,
614 CxListComparator comparator,
615 size_t item_size
616 ) {
617 cx_linked_list *list = cxMalloc(allocator, sizeof(cx_linked_list));
618 if (list == NULL)
619 return NULL;
621 list->base.cl = &cx_linked_list_class;
622 list->base.allocator = allocator;
623 list->base.cmpfunc = comparator;
624 list->base.itemsize = item_size;
625 list->base.capacity = SIZE_MAX;
626 list->base.size = 0;
628 list->begin = NULL;
629 list->end = NULL;
631 return (CxList) list;
632 }
634 CxList cxPointerLinkedListCreate(
635 CxAllocator allocator,
636 CxListComparator comparator
637 ) {
638 cx_linked_list *list = cxMalloc(allocator, sizeof(cx_linked_list));
639 if (list == NULL)
640 return NULL;
642 list->base.cl = &cx_pointer_linked_list_class;
643 list->base.allocator = allocator;
644 list->base.cmpfunc = comparator;
645 list->base.itemsize = sizeof(void *);
646 list->base.capacity = SIZE_MAX;
647 list->base.size = 0;
649 list->begin = NULL;
650 list->end = NULL;
652 return (CxList) list;
653 }
655 void cxLinkedListDestroy(CxList list) {
656 cx_linked_list *ll = (cx_linked_list *) list;
658 cx_linked_list_node *node = ll->begin;
659 while (node) {
660 void *next = node->next;
661 cxFree(list->allocator, node);
662 node = next;
663 }
665 cxFree(list->allocator, list);
666 }