src/array_list.c

Sun, 20 Nov 2022 17:06:00 +0100

author
Mike Becker <universe@uap-core.de>
date
Sun, 20 Nov 2022 17:06:00 +0100
changeset 624
b0bdff7d8203
parent 623
21082350a590
child 625
a4c4a50c067a
permissions
-rw-r--r--

#219: cx_arl_remove short-circuit for last element

universe@606 1 /*
universe@606 2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
universe@606 3 *
universe@606 4 * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
universe@606 5 *
universe@606 6 * Redistribution and use in source and binary forms, with or without
universe@606 7 * modification, are permitted provided that the following conditions are met:
universe@606 8 *
universe@606 9 * 1. Redistributions of source code must retain the above copyright
universe@606 10 * notice, this list of conditions and the following disclaimer.
universe@606 11 *
universe@606 12 * 2. Redistributions in binary form must reproduce the above copyright
universe@606 13 * notice, this list of conditions and the following disclaimer in the
universe@606 14 * documentation and/or other materials provided with the distribution.
universe@606 15 *
universe@606 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
universe@606 17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
universe@606 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
universe@606 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
universe@606 20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
universe@606 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
universe@606 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
universe@606 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
universe@606 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
universe@606 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
universe@606 26 * POSSIBILITY OF SUCH DAMAGE.
universe@606 27 */
universe@606 28
universe@606 29 #include "cx/array_list.h"
universe@610 30 #include <assert.h>
universe@610 31 #include <string.h>
universe@611 32 #include <stdint.h>
universe@606 33
universe@607 34 /* LOW LEVEL ARRAY LIST FUNCTIONS */
universe@607 35
universe@612 36 enum cx_array_copy_result cx_array_copy(
universe@610 37 void **target,
universe@610 38 size_t *size,
universe@610 39 size_t *capacity,
universe@610 40 size_t index,
universe@610 41 void const *src,
universe@610 42 size_t elem_size,
universe@610 43 size_t elem_count,
universe@610 44 struct cx_array_reallocator_s *reallocator
universe@610 45 ) {
universe@610 46 /* assert pointers */
universe@610 47 assert(target != NULL);
universe@610 48 assert(size != NULL);
universe@610 49 assert(src != NULL);
universe@607 50
universe@610 51 /* determine capacity */
universe@610 52 size_t cap = capacity == NULL ? *size : *capacity;
universe@610 53
universe@610 54 /* check if resize is required */
universe@610 55 size_t newsize = index + elem_count;
universe@610 56 bool needrealloc = newsize > cap;
universe@610 57
universe@610 58 /* reallocate if possible */
universe@610 59 if (needrealloc) {
universe@610 60 /* a reallocator and a capacity variable must be available */
universe@610 61 if (reallocator == NULL || capacity == NULL) {
universe@610 62 return CX_ARRAY_COPY_REALLOC_NOT_SUPPORTED;
universe@610 63 }
universe@610 64
universe@611 65 /* check, if we need to repair the src pointer */
universe@611 66 uintptr_t targetaddr = (uintptr_t) *target;
universe@611 67 uintptr_t srcaddr = (uintptr_t) src;
universe@611 68 bool repairsrc = targetaddr <= srcaddr
universe@611 69 && srcaddr < targetaddr + cap * elem_size;
universe@611 70
universe@610 71 /* increase capacity linearly */
universe@610 72 cap += 16;
universe@610 73
universe@610 74 /* perform reallocation */
universe@610 75 void *newmem = reallocator->realloc(
universe@610 76 *target, cap, elem_size, reallocator
universe@610 77 );
universe@610 78 if (newmem == NULL) {
universe@610 79 return CX_ARRAY_COPY_REALLOC_FAILED;
universe@610 80 }
universe@610 81
universe@611 82 /* repair src pointer, if necessary */
universe@611 83 if (repairsrc) {
universe@611 84 src = ((char *) newmem) + (srcaddr - targetaddr);
universe@611 85 }
universe@611 86
universe@610 87 /* store new pointer and capacity */
universe@610 88 *target = newmem;
universe@610 89 *capacity = cap;
universe@610 90 }
universe@610 91
universe@610 92 /* determine target pointer */
universe@610 93 char *start = *target;
universe@610 94 start += index * elem_size;
universe@610 95
universe@610 96 /* copy elements and set new size */
universe@611 97 memmove(start, src, elem_count * elem_size);
universe@610 98 *size = newsize;
universe@610 99
universe@610 100 /* return successfully */
universe@610 101 return CX_ARRAY_COPY_SUCCESS;
universe@610 102 }
universe@607 103
universe@623 104 #define CX_ARRAY_SWAP_SBO_SIZE 512
universe@623 105
universe@623 106 void cx_array_swap(
universe@623 107 void *arr,
universe@623 108 size_t elem_size,
universe@623 109 size_t idx1,
universe@623 110 size_t idx2
universe@623 111 ) {
universe@623 112 /* short circuit */
universe@623 113 if (idx1 == idx2) return;
universe@623 114
universe@623 115 char sbo_mem[CX_ARRAY_SWAP_SBO_SIZE];
universe@623 116 void *tmp;
universe@623 117
universe@623 118 /* decide if we can use the local buffer */
universe@623 119 if (elem_size > CX_ARRAY_SWAP_SBO_SIZE) {
universe@623 120 tmp = malloc(elem_size);
universe@623 121 /* we don't want to enforce error handling */
universe@623 122 if (tmp == NULL) abort();
universe@623 123 } else {
universe@623 124 tmp = sbo_mem;
universe@623 125 }
universe@623 126
universe@623 127 /* calculate memory locations */
universe@623 128 char *left = arr, *right = arr;
universe@623 129 left += idx1 * elem_size;
universe@623 130 right += idx2 * elem_size;
universe@623 131
universe@623 132 /* three-way swap */
universe@623 133 memcpy(tmp, left, elem_size);
universe@623 134 memcpy(left, right, elem_size);
universe@623 135 memcpy(right, tmp, elem_size);
universe@623 136
universe@623 137 /* free dynamic memory, if it was needed */
universe@623 138 if (tmp != sbo_mem) {
universe@623 139 free(tmp);
universe@623 140 }
universe@623 141 }
universe@623 142
universe@607 143 /* HIGH LEVEL ARRAY LIST FUNCTIONS */
universe@607 144
universe@607 145 typedef struct {
universe@607 146 struct cx_list_s base;
universe@607 147 void *data;
universe@610 148 struct cx_array_reallocator_s reallocator;
universe@607 149 } cx_array_list;
universe@607 150
universe@610 151 static void *cx_arl_realloc(
universe@610 152 void *array,
universe@610 153 size_t capacity,
universe@610 154 size_t elem_size,
universe@610 155 struct cx_array_reallocator_s *alloc
universe@610 156 ) {
universe@610 157 /* retrieve the pointer to the list allocator */
universe@610 158 CxAllocator const *al = alloc->ptr1;
universe@610 159
universe@610 160 /* use the list allocator to reallocate the memory */
universe@610 161 return cxRealloc(al, array, capacity * elem_size);
universe@610 162 }
universe@610 163
universe@607 164 static void cx_arl_destructor(struct cx_list_s *list) {
universe@610 165 cx_array_list *arl = (cx_array_list *) list;
universe@607 166 cxFree(list->allocator, arl->data);
universe@607 167 }
universe@607 168
universe@607 169 static int cx_arl_add(
universe@607 170 struct cx_list_s *list,
universe@607 171 void const *elem
universe@607 172 ) {
universe@610 173 cx_array_list *arl = (cx_array_list *) list;
universe@610 174 return cx_array_copy(
universe@610 175 &arl->data,
universe@610 176 &list->size,
universe@610 177 &list->capacity,
universe@610 178 list->size,
universe@610 179 elem,
universe@610 180 list->itemsize,
universe@610 181 1,
universe@610 182 &arl->reallocator
universe@610 183 );
universe@607 184 }
universe@607 185
universe@607 186 static int cx_arl_insert(
universe@607 187 struct cx_list_s *list,
universe@607 188 size_t index,
universe@607 189 void const *elem
universe@607 190 ) {
universe@611 191 if (index > list->size) {
universe@611 192 return 1;
universe@611 193 } else if (index == list->size) {
universe@611 194 return cx_arl_add(list, elem);
universe@611 195 } else {
universe@611 196 cx_array_list *arl = (cx_array_list *) list;
universe@611 197
universe@611 198 /* move elements starting at index to the right */
universe@611 199 if (cx_array_copy(
universe@611 200 &arl->data,
universe@611 201 &list->size,
universe@611 202 &list->capacity,
universe@611 203 index + 1,
universe@611 204 ((char *) arl->data) + index * list->itemsize,
universe@611 205 list->itemsize,
universe@611 206 list->size - index,
universe@611 207 &arl->reallocator
universe@611 208 )) {
universe@611 209 return 1;
universe@611 210 }
universe@611 211
universe@611 212 /* place the element */
universe@611 213 memcpy(((char *) arl->data) + index * list->itemsize,
universe@611 214 elem, list->itemsize);
universe@611 215
universe@611 216 return 0;
universe@611 217 }
universe@607 218 }
universe@607 219
universe@607 220 static int cx_arl_insert_iter(
universe@607 221 struct cx_iterator_s *iter,
universe@607 222 void const *elem,
universe@607 223 int prepend
universe@607 224 ) {
universe@619 225 struct cx_list_s *list = iter->src_handle;
universe@619 226 if (iter->index < list->size) {
universe@619 227 int result = cx_arl_insert(
universe@619 228 list,
universe@619 229 iter->index + 1 - prepend,
universe@619 230 elem
universe@619 231 );
universe@619 232 if (result == 0 && prepend != 0) {
universe@619 233 iter->index++;
universe@619 234 iter->elem_handle = ((char *) iter->elem_handle) + list->itemsize;
universe@619 235 }
universe@619 236 return result;
universe@619 237 } else {
universe@619 238 int result = cx_arl_add(list, elem);
universe@619 239 iter->index = list->size;
universe@619 240 return result;
universe@619 241 }
universe@607 242 }
universe@607 243
universe@607 244 static int cx_arl_remove(
universe@607 245 struct cx_list_s *list,
universe@607 246 size_t index
universe@607 247 ) {
universe@613 248 /* out-of-bounds check */
universe@613 249 if (index >= list->size) {
universe@613 250 return 1;
universe@613 251 }
universe@613 252
universe@624 253 /* short-circuit removal of last element */
universe@624 254 if (index == list->size - 1) {
universe@624 255 list->size--;
universe@624 256 return 0;
universe@624 257 }
universe@613 258
universe@613 259 /* just move the elements starting at index to the left */
universe@624 260 cx_array_list *arl = (cx_array_list *) list;
universe@613 261 int result = cx_array_copy(
universe@613 262 &arl->data,
universe@613 263 &list->size,
universe@613 264 &list->capacity,
universe@613 265 index,
universe@613 266 ((char *) arl->data) + (index + 1) * list->itemsize,
universe@613 267 list->itemsize,
universe@613 268 list->size - index,
universe@613 269 &arl->reallocator
universe@613 270 );
universe@613 271 if (result == 0) {
universe@613 272 /* decrease the size */
universe@613 273 list->size--;
universe@613 274 }
universe@613 275 return result;
universe@607 276 }
universe@607 277
universe@610 278 static void *cx_arl_at(
universe@607 279 struct cx_list_s const *list,
universe@607 280 size_t index
universe@607 281 ) {
universe@610 282 if (index < list->size) {
universe@610 283 cx_array_list const *arl = (cx_array_list const *) list;
universe@610 284 char *space = arl->data;
universe@610 285 return space + index * list->itemsize;
universe@610 286 } else {
universe@610 287 return NULL;
universe@610 288 }
universe@607 289 }
universe@607 290
universe@607 291 static size_t cx_arl_find(
universe@607 292 struct cx_list_s const *list,
universe@607 293 void const *elem
universe@607 294 ) {
universe@614 295 char *cur = ((cx_array_list const *) list)->data;
universe@614 296
universe@614 297 for (size_t i = 0; i < list->size; i++) {
universe@614 298 if (0 == list->cmpfunc(elem, cur)) {
universe@614 299 return i;
universe@614 300 }
universe@614 301 cur += list->itemsize;
universe@614 302 }
universe@614 303
universe@614 304 return list->size;
universe@607 305 }
universe@607 306
universe@607 307 static void cx_arl_sort(struct cx_list_s *list) {
universe@615 308 qsort(((cx_array_list *) list)->data,
universe@615 309 list->size,
universe@615 310 list->itemsize,
universe@615 311 list->cmpfunc
universe@615 312 );
universe@607 313 }
universe@607 314
universe@607 315 static int cx_arl_compare(
universe@607 316 struct cx_list_s const *list,
universe@607 317 struct cx_list_s const *other
universe@607 318 ) {
universe@622 319 if (list->size == other->size) {
universe@622 320 char const *left = ((cx_array_list const *) list)->data;
universe@622 321 char const *right = ((cx_array_list const *) other)->data;
universe@622 322 for (size_t i = 0; i < list->size; i++) {
universe@622 323 int d = list->cmpfunc(left, right);
universe@622 324 if (d != 0) {
universe@622 325 return d;
universe@622 326 }
universe@622 327 left += list->itemsize;
universe@622 328 right += other->itemsize;
universe@622 329 }
universe@622 330 return 0;
universe@622 331 } else {
universe@622 332 return list->size < other->size ? -1 : 1;
universe@622 333 }
universe@607 334 }
universe@607 335
universe@607 336 static void cx_arl_reverse(struct cx_list_s *list) {
universe@623 337 if (list->size < 2) return;
universe@623 338 void *data = ((cx_array_list const *) list)->data;
universe@623 339 size_t half = list->size / 2;
universe@623 340 for (size_t i = 0; i < half; i++) {
universe@623 341 cx_array_swap(data, list->itemsize, i, list->size - 1 - i);
universe@623 342 }
universe@607 343 }
universe@607 344
universe@616 345 static bool cx_arl_iter_valid(struct cx_iterator_s const *iter) {
universe@616 346 struct cx_list_s const *list = iter->src_handle;
universe@616 347 return iter->index < list->size;
universe@616 348 }
universe@616 349
universe@616 350 static void *cx_arl_iter_current(struct cx_iterator_s const *iter) {
universe@616 351 return iter->elem_handle;
universe@616 352 }
universe@616 353
universe@616 354 static void cx_arl_iter_next(struct cx_iterator_s *iter) {
universe@616 355 if (iter->remove) {
universe@616 356 iter->remove = false;
universe@616 357 cx_arl_remove(iter->src_handle, iter->index);
universe@616 358 } else {
universe@616 359 iter->index++;
universe@620 360 iter->elem_handle =
universe@620 361 ((char *) iter->elem_handle)
universe@620 362 + ((struct cx_list_s const *) iter->src_handle)->itemsize;
universe@616 363 }
universe@616 364 }
universe@616 365
universe@607 366 static struct cx_iterator_s cx_arl_iterator(
universe@607 367 struct cx_list_s *list,
universe@607 368 size_t index
universe@607 369 ) {
universe@607 370 struct cx_iterator_s iter;
universe@607 371
universe@616 372 iter.index = index;
universe@616 373 iter.src_handle = list;
universe@616 374 iter.elem_handle = cx_arl_at(list, index);
universe@616 375 iter.valid = cx_arl_iter_valid;
universe@616 376 iter.current = cx_arl_iter_current;
universe@616 377 iter.next = cx_arl_iter_next;
universe@616 378 iter.remove = false;
universe@616 379
universe@607 380 return iter;
universe@607 381 }
universe@607 382
universe@607 383 static cx_list_class cx_array_list_class = {
universe@607 384 cx_arl_destructor,
universe@607 385 cx_arl_add,
universe@607 386 cx_arl_insert,
universe@607 387 cx_arl_insert_iter,
universe@607 388 cx_arl_remove,
universe@607 389 cx_arl_at,
universe@607 390 cx_arl_find,
universe@607 391 cx_arl_sort,
universe@607 392 cx_arl_compare,
universe@607 393 cx_arl_reverse,
universe@607 394 cx_arl_iterator,
universe@607 395 };
universe@607 396
universe@606 397 CxList *cxArrayListCreate(
universe@606 398 CxAllocator const *allocator,
universe@606 399 CxListComparator comparator,
universe@606 400 size_t item_size,
universe@606 401 size_t initial_capacity
universe@606 402 ) {
universe@607 403 cx_array_list *list = cxCalloc(allocator, 1, sizeof(cx_array_list));
universe@607 404 if (list == NULL) return NULL;
universe@607 405
universe@607 406 list->data = cxCalloc(allocator, initial_capacity, item_size);
universe@607 407 if (list->data == NULL) {
universe@607 408 cxFree(allocator, list);
universe@607 409 return NULL;
universe@607 410 }
universe@607 411
universe@607 412 list->base.cl = &cx_array_list_class;
universe@607 413 list->base.allocator = allocator;
universe@607 414 list->base.cmpfunc = comparator;
universe@607 415 list->base.itemsize = item_size;
universe@607 416 list->base.capacity = initial_capacity;
universe@607 417
universe@610 418 /* configure the reallocator */
universe@610 419 list->reallocator.realloc = cx_arl_realloc;
universe@610 420 list->reallocator.ptr1 = (void *) allocator;
universe@610 421
universe@607 422 return (CxList *) list;
universe@606 423 }

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