src/linked_list.c

Mon, 27 Sep 2021 17:49:23 +0200

author
Mike Becker <universe@uap-core.de>
date
Mon, 27 Sep 2021 17:49:23 +0200
changeset 437
9d4971ea0625
parent 436
ca9ce2297c29
child 438
cd3069757010
permissions
-rw-r--r--

implement linked list find

universe@398 1 /*
universe@398 2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
universe@398 3 *
universe@398 4 * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
universe@398 5 *
universe@398 6 * Redistribution and use in source and binary forms, with or without
universe@398 7 * modification, are permitted provided that the following conditions are met:
universe@398 8 *
universe@398 9 * 1. Redistributions of source code must retain the above copyright
universe@398 10 * notice, this list of conditions and the following disclaimer.
universe@398 11 *
universe@398 12 * 2. Redistributions in binary form must reproduce the above copyright
universe@398 13 * notice, this list of conditions and the following disclaimer in the
universe@398 14 * documentation and/or other materials provided with the distribution.
universe@398 15 *
universe@398 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
universe@398 17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
universe@398 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
universe@398 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
universe@398 20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
universe@398 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
universe@398 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
universe@398 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
universe@398 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
universe@398 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
universe@398 26 * POSSIBILITY OF SUCH DAMAGE.
universe@398 27 */
universe@398 28
universe@398 29 #include "cx/linked_list.h"
universe@401 30 #include <stdint.h>
universe@401 31 #include <string.h>
universe@398 32
universe@398 33 /* LOW LEVEL LINKED LIST FUNCTIONS */
universe@398 34
universe@398 35 #define CX_LL_PTR(cur, off) ((void**)(((char*)cur)+off))
universe@398 36
universe@400 37 void *cx_linked_list_last(void **begin, void **end, ptrdiff_t loc_next) {
universe@398 38 if (end != NULL) {
universe@398 39 return *end;
universe@398 40 } else {
universe@398 41 if (begin == NULL || *begin == NULL)
universe@398 42 return NULL;
universe@398 43
universe@398 44 void *cur = *begin;
universe@398 45 void *last;
universe@398 46 do {
universe@398 47 last = cur;
universe@398 48 } while ((cur = *CX_LL_PTR(cur, loc_next)) != NULL);
universe@398 49
universe@398 50 return last;
universe@398 51 }
universe@398 52 }
universe@398 53
universe@406 54 int cx_linked_list_add(void **begin, void **end, ptrdiff_t loc_prev, ptrdiff_t loc_next, void *new_node) {
universe@398 55 void *last = cx_linked_list_last(begin, end, loc_next);
universe@398 56 if (last == NULL) {
universe@398 57 if (begin == NULL) {
universe@428 58 // no current list and no begin ptr to write to - we don't find something to append to
universe@398 59 return 1;
universe@398 60 } else {
universe@428 61 // start fresh list
universe@406 62 *begin = new_node;
universe@398 63 }
universe@428 64 } else {
universe@428 65 // if there is a last node, update its next pointer
universe@428 66 void **next = CX_LL_PTR(last, loc_next);
universe@428 67 *next = new_node;
universe@398 68 }
universe@398 69
universe@428 70 // if there is an end pointer, update it
universe@408 71 if (end != NULL) {
universe@408 72 *end = cx_linked_list_last(&new_node, NULL, loc_next);
universe@408 73 }
universe@428 74
universe@428 75 // if the nodes use a prev pointer, update it
universe@398 76 if (loc_prev >= 0) {
universe@406 77 void **prev = CX_LL_PTR(new_node, loc_prev);
universe@398 78 *prev = last;
universe@398 79 }
universe@398 80
universe@398 81 return 0;
universe@398 82 }
universe@398 83
universe@398 84 /* HIGH LEVEL LINKED LIST IMPLEMENTATION */
universe@398 85
universe@402 86 struct cx_linked_list_node {
universe@402 87 void *prev;
universe@402 88 void *next;
universe@403 89 char payload[];
universe@402 90 };
universe@402 91
universe@398 92 typedef struct {
universe@435 93 cx_list_s base;
universe@401 94 void *begin;
universe@401 95 void *end;
universe@406 96 ptrdiff_t loc_prev;
universe@406 97 ptrdiff_t loc_next;
universe@398 98 } cx_linked_list;
universe@398 99
universe@435 100 int cx_ll_add(cx_list_s *list, void *elem) {
universe@437 101 cx_linked_list *ll = (cx_linked_list *) list;
universe@398 102
universe@435 103 struct cx_linked_list_node *node = cxMalloc(list->allocator,
universe@406 104 sizeof(struct cx_linked_list_node) + list->itemsize);
universe@398 105 if (node == NULL)
universe@398 106 return 1;
universe@398 107
universe@435 108 node->next = node->prev = NULL;
universe@406 109 memcpy(node->payload, elem, list->itemsize);
universe@399 110
universe@398 111 int ret = cx_linked_list_add(
universe@437 112 &ll->begin, &ll->end,
universe@402 113 offsetof(struct cx_linked_list_node, prev),
universe@402 114 offsetof(struct cx_linked_list_node, next),
universe@398 115 node
universe@398 116 );
universe@398 117 if (ret == 0) {
universe@401 118 list->size++;
universe@398 119 return 0;
universe@398 120 } else {
universe@398 121 return ret;
universe@398 122 }
universe@398 123 }
universe@398 124
universe@435 125 int cx_ll_insert(cx_list_s *list, size_t index, void *elem) {
universe@437 126 cx_linked_list *ll = (cx_linked_list *) list;
universe@398 127 // TODO: implement using low level API
universe@398 128 return 1;
universe@398 129 }
universe@398 130
universe@435 131 void *cx_ll_remove(cx_list_s *list, size_t index) {
universe@437 132 cx_linked_list *ll = (cx_linked_list *) list;
universe@398 133 // TODO: implement using low level API
universe@398 134 return NULL;
universe@398 135 }
universe@398 136
universe@435 137 size_t cx_ll_find(cx_list_s *list, void *elem) {
universe@437 138 CxListComparator cmp = list->cmpfunc;
universe@437 139 cx_linked_list *ll = (cx_linked_list *) list;
universe@437 140
universe@437 141 size_t index;
universe@437 142 struct cx_linked_list_node* node = ll->begin;
universe@437 143 for (index = 0 ; index < list->size ; index++) {
universe@437 144 void* current = node->payload;
universe@437 145 if (cmp(current, elem) == 0) {
universe@437 146 return index;
universe@437 147 }
universe@437 148 node = node->next;
universe@437 149 }
universe@437 150 return index;
universe@398 151 }
universe@398 152
universe@435 153 void *cx_ll_last(cx_list_s *list) {
universe@435 154 cx_linked_list *linkedList = (cx_linked_list *) list;
universe@404 155 struct cx_linked_list_node *last = cx_linked_list_last(
universe@435 156 NULL, &linkedList->end, offsetof(struct cx_linked_list_node, next));
universe@404 157 return &last->payload;
universe@404 158 }
universe@398 159
universe@398 160 cx_list_class cx_linked_list_class = {
universe@398 161 cx_ll_add,
universe@398 162 cx_ll_insert,
universe@398 163 cx_ll_remove,
universe@404 164 cx_ll_find,
universe@404 165 cx_ll_last
universe@398 166 };
universe@398 167
universe@406 168 CxList cxLinkedListCreate(CxAllocator allocator, CxListComparator comparator, size_t item_size) {
universe@435 169 cx_linked_list* list = cxMalloc(allocator, sizeof(cx_linked_list));
universe@398 170 if (list == NULL)
universe@398 171 return NULL;
universe@398 172
universe@435 173 list->base.cl = &cx_linked_list_class;
universe@435 174 list->base.allocator = allocator;
universe@435 175 list->base.cmpfunc = comparator;
universe@435 176 list->base.itemsize = item_size;
universe@435 177 list->base.capacity = SIZE_MAX;
universe@406 178
universe@435 179 list->begin = NULL;
universe@435 180 list->loc_prev = offsetof(struct cx_linked_list_node, prev);
universe@435 181 list->loc_next = offsetof(struct cx_linked_list_node, next);
universe@406 182
universe@435 183 CxList result = (CxList) list;
universe@435 184 cxLinkedListRecalculateSize(result);
universe@435 185 return result;
universe@406 186 }
universe@406 187
universe@409 188 void cxLinkedListDestroy(CxList list) {
universe@436 189 cx_linked_list* ll = (cx_linked_list*) list;
universe@436 190
universe@436 191 struct cx_linked_list_node* node = ll->begin;
universe@436 192 while (node) {
universe@436 193 void* next = node->next;
universe@436 194 cxFree(list->allocator, node);
universe@436 195 node = next;
universe@436 196 }
universe@436 197
universe@435 198 cxFree(list->allocator, list);
universe@409 199 }
universe@409 200
universe@406 201 size_t cxLinkedListRecalculateSize(CxList list) {
universe@435 202 cx_linked_list *ll = (cx_linked_list *) list;
universe@406 203
universe@406 204 if (ll->begin == NULL) {
universe@435 205 ll->base.size = 0;
universe@407 206 ll->end = NULL;
universe@406 207 return 0;
universe@406 208 } else {
universe@406 209 void *cur = ll->begin;
universe@407 210 void *last;
universe@435 211 size_t size = 0;
universe@406 212 do {
universe@407 213 last = cur;
universe@406 214 size++;
universe@406 215 } while ((cur = *CX_LL_PTR(cur, ll->loc_next)) != NULL);
universe@407 216 ll->end = last;
universe@435 217 ll->base.size = size;
universe@406 218 return size;
universe@398 219 }
universe@406 220 }

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