Mon, 08 Feb 2021 00:18:09 +0100
simplifies linked list descriptor
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 | // TODO: how do we report error messages? |
universe@398 | 56 | if (loc_next < 0 || (begin == NULL && end == NULL)) { |
universe@398 | 57 | return 1; |
universe@398 | 58 | } |
universe@398 | 59 | |
universe@398 | 60 | void *last = cx_linked_list_last(begin, end, loc_next); |
universe@398 | 61 | if (last == NULL) { |
universe@398 | 62 | if (begin == NULL) { |
universe@398 | 63 | return 1; |
universe@398 | 64 | } else { |
universe@406 | 65 | *begin = new_node; |
universe@398 | 66 | return 0; |
universe@398 | 67 | } |
universe@398 | 68 | } |
universe@398 | 69 | |
universe@398 | 70 | void **next = CX_LL_PTR(last, loc_next); |
universe@406 | 71 | *next = new_node; |
universe@398 | 72 | if (loc_prev >= 0) { |
universe@406 | 73 | void **prev = CX_LL_PTR(new_node, loc_prev); |
universe@398 | 74 | *prev = last; |
universe@398 | 75 | } |
universe@398 | 76 | |
universe@398 | 77 | return 0; |
universe@398 | 78 | } |
universe@398 | 79 | |
universe@398 | 80 | /* HIGH LEVEL LINKED LIST IMPLEMENTATION */ |
universe@398 | 81 | |
universe@402 | 82 | struct cx_linked_list_node { |
universe@402 | 83 | void *prev; |
universe@402 | 84 | void *next; |
universe@403 | 85 | char payload[]; |
universe@402 | 86 | }; |
universe@402 | 87 | |
universe@398 | 88 | typedef struct { |
universe@401 | 89 | void *begin; |
universe@401 | 90 | void *end; |
universe@406 | 91 | ptrdiff_t loc_prev; |
universe@406 | 92 | ptrdiff_t loc_next; |
universe@398 | 93 | } cx_linked_list; |
universe@398 | 94 | |
universe@398 | 95 | int cx_ll_add(cx_list *list, void *elem) { |
universe@406 | 96 | cx_linked_list *listdata = (cx_linked_list *) list->listdata; |
universe@398 | 97 | CxAllocator allocator = list->allocator; |
universe@398 | 98 | |
universe@402 | 99 | struct cx_linked_list_node *node = cxMalloc(allocator, |
universe@406 | 100 | sizeof(struct cx_linked_list_node) + list->itemsize); |
universe@398 | 101 | if (node == NULL) |
universe@398 | 102 | return 1; |
universe@398 | 103 | |
universe@402 | 104 | node->next = NULL; |
universe@406 | 105 | memcpy(node->payload, elem, list->itemsize); |
universe@399 | 106 | |
universe@398 | 107 | int ret = cx_linked_list_add( |
universe@401 | 108 | &listdata->begin, |
universe@401 | 109 | &listdata->end, |
universe@402 | 110 | offsetof(struct cx_linked_list_node, prev), |
universe@402 | 111 | offsetof(struct cx_linked_list_node, next), |
universe@398 | 112 | node |
universe@398 | 113 | ); |
universe@398 | 114 | if (ret == 0) { |
universe@401 | 115 | list->size++; |
universe@398 | 116 | return 0; |
universe@398 | 117 | } else { |
universe@398 | 118 | return ret; |
universe@398 | 119 | } |
universe@398 | 120 | } |
universe@398 | 121 | |
universe@398 | 122 | int cx_ll_insert(cx_list *list, size_t index, void *elem) { |
universe@406 | 123 | cx_linked_list *listdata = (cx_linked_list *) list->listdata; |
universe@398 | 124 | // TODO: implement using low level API |
universe@398 | 125 | return 1; |
universe@398 | 126 | } |
universe@398 | 127 | |
universe@398 | 128 | void *cx_ll_remove(cx_list *list, size_t index) { |
universe@406 | 129 | cx_linked_list *listdata = (cx_linked_list *) list->listdata; |
universe@398 | 130 | // TODO: implement using low level API |
universe@398 | 131 | return NULL; |
universe@398 | 132 | } |
universe@398 | 133 | |
universe@398 | 134 | size_t cx_ll_find(cx_list *list, void *elem) { |
universe@406 | 135 | cx_linked_list *listdata = (cx_linked_list *) list->listdata; |
universe@398 | 136 | // TODO: implement using low level API |
universe@398 | 137 | return 0; |
universe@398 | 138 | } |
universe@398 | 139 | |
universe@404 | 140 | void *cx_ll_last(cx_list *list) { |
universe@406 | 141 | cx_linked_list *listdata = (cx_linked_list *) list->listdata; |
universe@404 | 142 | struct cx_linked_list_node *last = cx_linked_list_last( |
universe@406 | 143 | NULL, &listdata->end, offsetof(struct cx_linked_list_node, next)); |
universe@404 | 144 | return &last->payload; |
universe@404 | 145 | } |
universe@398 | 146 | |
universe@398 | 147 | cx_list_class cx_linked_list_class = { |
universe@398 | 148 | cx_ll_add, |
universe@398 | 149 | cx_ll_insert, |
universe@398 | 150 | cx_ll_remove, |
universe@404 | 151 | cx_ll_find, |
universe@404 | 152 | cx_ll_last |
universe@398 | 153 | }; |
universe@398 | 154 | |
universe@406 | 155 | CxList cxLinkedListCreate(CxAllocator allocator, CxListComparator comparator, size_t item_size) { |
universe@406 | 156 | CxLinkedListDesc desc; |
universe@406 | 157 | desc.item_size = item_size; |
universe@407 | 158 | desc.begin = NULL; |
universe@406 | 159 | desc.loc_prev = offsetof(struct cx_linked_list_node, prev); |
universe@406 | 160 | desc.loc_next = offsetof(struct cx_linked_list_node, next); |
universe@406 | 161 | |
universe@406 | 162 | return cxLinkedListWrap(allocator, comparator, desc); |
universe@406 | 163 | } |
universe@406 | 164 | |
universe@406 | 165 | CxList cxLinkedListWrap(CxAllocator allocator, CxListComparator comparator, CxLinkedListDesc desc) { |
universe@406 | 166 | CxList list = cxMalloc(allocator, sizeof(list) + sizeof(cx_linked_list)); |
universe@398 | 167 | if (list == NULL) |
universe@398 | 168 | return NULL; |
universe@398 | 169 | |
universe@398 | 170 | list->cl = &cx_linked_list_class; |
universe@398 | 171 | list->data.allocator = allocator; |
universe@398 | 172 | list->data.cmpfunc = comparator; |
universe@406 | 173 | list->data.itemsize = desc.item_size; |
universe@401 | 174 | list->data.capacity = SIZE_MAX; |
universe@406 | 175 | |
universe@406 | 176 | cx_linked_list *ll = (cx_linked_list *) list->data.listdata; |
universe@407 | 177 | ll->begin = desc.begin; |
universe@406 | 178 | ll->loc_prev = desc.loc_prev; |
universe@406 | 179 | ll->loc_next = desc.loc_next; |
universe@406 | 180 | cxLinkedListRecalculateSize(list); |
universe@406 | 181 | |
universe@406 | 182 | return list; |
universe@406 | 183 | } |
universe@406 | 184 | |
universe@406 | 185 | size_t cxLinkedListRecalculateSize(CxList list) { |
universe@406 | 186 | cx_linked_list *ll = (cx_linked_list *) list->data.listdata; |
universe@406 | 187 | |
universe@406 | 188 | if (ll->begin == NULL) { |
universe@406 | 189 | list->data.size = 0; |
universe@407 | 190 | ll->end = NULL; |
universe@406 | 191 | return 0; |
universe@406 | 192 | } else { |
universe@406 | 193 | void *cur = ll->begin; |
universe@407 | 194 | void *last; |
universe@406 | 195 | size_t size; |
universe@406 | 196 | do { |
universe@407 | 197 | last = cur; |
universe@406 | 198 | size++; |
universe@406 | 199 | } while ((cur = *CX_LL_PTR(cur, ll->loc_next)) != NULL); |
universe@407 | 200 | ll->end = last; |
universe@406 | 201 | list->data.size = size; |
universe@406 | 202 | return size; |
universe@398 | 203 | } |
universe@406 | 204 | } |