Mon, 08 Feb 2021 00:20:52 +0100
fixes cx_linked_list_add not recalculating end
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>
33 /* LOW LEVEL LINKED LIST FUNCTIONS */
35 #define CX_LL_PTR(cur, off) ((void**)(((char*)cur)+off))
37 void *cx_linked_list_last(void **begin, void **end, ptrdiff_t loc_next) {
38 if (end != NULL) {
39 return *end;
40 } else {
41 if (begin == NULL || *begin == NULL)
42 return NULL;
44 void *cur = *begin;
45 void *last;
46 do {
47 last = cur;
48 } while ((cur = *CX_LL_PTR(cur, loc_next)) != NULL);
50 return last;
51 }
52 }
54 int cx_linked_list_add(void **begin, void **end, ptrdiff_t loc_prev, ptrdiff_t loc_next, void *new_node) {
55 // TODO: how do we report error messages?
56 if (loc_next < 0 || (begin == NULL && end == NULL)) {
57 return 1;
58 }
60 void *last = cx_linked_list_last(begin, end, loc_next);
61 if (last == NULL) {
62 if (begin == NULL) {
63 return 1;
64 } else {
65 *begin = new_node;
66 return 0;
67 }
68 }
70 void **next = CX_LL_PTR(last, loc_next);
71 *next = new_node;
72 if (end != NULL) {
73 *end = cx_linked_list_last(&new_node, NULL, loc_next);
74 }
75 if (loc_prev >= 0) {
76 void **prev = CX_LL_PTR(new_node, loc_prev);
77 *prev = last;
78 }
80 return 0;
81 }
83 /* HIGH LEVEL LINKED LIST IMPLEMENTATION */
85 struct cx_linked_list_node {
86 void *prev;
87 void *next;
88 char payload[];
89 };
91 typedef struct {
92 void *begin;
93 void *end;
94 ptrdiff_t loc_prev;
95 ptrdiff_t loc_next;
96 } cx_linked_list;
98 int cx_ll_add(cx_list *list, void *elem) {
99 cx_linked_list *listdata = (cx_linked_list *) list->listdata;
100 CxAllocator allocator = list->allocator;
102 struct cx_linked_list_node *node = cxMalloc(allocator,
103 sizeof(struct cx_linked_list_node) + list->itemsize);
104 if (node == NULL)
105 return 1;
107 node->next = NULL;
108 memcpy(node->payload, elem, list->itemsize);
110 int ret = cx_linked_list_add(
111 &listdata->begin,
112 &listdata->end,
113 offsetof(struct cx_linked_list_node, prev),
114 offsetof(struct cx_linked_list_node, next),
115 node
116 );
117 if (ret == 0) {
118 list->size++;
119 return 0;
120 } else {
121 return ret;
122 }
123 }
125 int cx_ll_insert(cx_list *list, size_t index, void *elem) {
126 cx_linked_list *listdata = (cx_linked_list *) list->listdata;
127 // TODO: implement using low level API
128 return 1;
129 }
131 void *cx_ll_remove(cx_list *list, size_t index) {
132 cx_linked_list *listdata = (cx_linked_list *) list->listdata;
133 // TODO: implement using low level API
134 return NULL;
135 }
137 size_t cx_ll_find(cx_list *list, void *elem) {
138 cx_linked_list *listdata = (cx_linked_list *) list->listdata;
139 // TODO: implement using low level API
140 return 0;
141 }
143 void *cx_ll_last(cx_list *list) {
144 cx_linked_list *listdata = (cx_linked_list *) list->listdata;
145 struct cx_linked_list_node *last = cx_linked_list_last(
146 NULL, &listdata->end, offsetof(struct cx_linked_list_node, next));
147 return &last->payload;
148 }
150 cx_list_class cx_linked_list_class = {
151 cx_ll_add,
152 cx_ll_insert,
153 cx_ll_remove,
154 cx_ll_find,
155 cx_ll_last
156 };
158 CxList cxLinkedListCreate(CxAllocator allocator, CxListComparator comparator, size_t item_size) {
159 CxLinkedListDesc desc;
160 desc.item_size = item_size;
161 desc.begin = NULL;
162 desc.loc_prev = offsetof(struct cx_linked_list_node, prev);
163 desc.loc_next = offsetof(struct cx_linked_list_node, next);
165 return cxLinkedListWrap(allocator, comparator, desc);
166 }
168 CxList cxLinkedListWrap(CxAllocator allocator, CxListComparator comparator, CxLinkedListDesc desc) {
169 CxList list = cxMalloc(allocator, sizeof(list) + sizeof(cx_linked_list));
170 if (list == NULL)
171 return NULL;
173 list->cl = &cx_linked_list_class;
174 list->data.allocator = allocator;
175 list->data.cmpfunc = comparator;
176 list->data.itemsize = desc.item_size;
177 list->data.capacity = SIZE_MAX;
179 cx_linked_list *ll = (cx_linked_list *) list->data.listdata;
180 ll->begin = desc.begin;
181 ll->loc_prev = desc.loc_prev;
182 ll->loc_next = desc.loc_next;
183 cxLinkedListRecalculateSize(list);
185 return list;
186 }
188 size_t cxLinkedListRecalculateSize(CxList list) {
189 cx_linked_list *ll = (cx_linked_list *) list->data.listdata;
191 if (ll->begin == NULL) {
192 list->data.size = 0;
193 ll->end = NULL;
194 return 0;
195 } else {
196 void *cur = ll->begin;
197 void *last;
198 size_t size;
199 do {
200 last = cur;
201 size++;
202 } while ((cur = *CX_LL_PTR(cur, ll->loc_next)) != NULL);
203 ll->end = last;
204 list->data.size = size;
205 return size;
206 }
207 }