ucx: src/linked_list.c@b447539ec255

     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 (loc_prev >= 0) {

    73         void **prev = CX_LL_PTR(new_node, loc_prev);

    74         *prev = last;

    75     }

    77     return 0;

    78 }

    80 /* HIGH LEVEL LINKED LIST IMPLEMENTATION */

    82 struct cx_linked_list_node {

    83     void *prev;

    84     void *next;

    85     char payload[];

    86 };

    88 typedef struct {

    89     void *begin;

    90     void *end;

    91     ptrdiff_t loc_prev;

    92     ptrdiff_t loc_next;

    93 } cx_linked_list;

    95 int cx_ll_add(cx_list *list, void *elem) {

    96     cx_linked_list *listdata = (cx_linked_list *) list->listdata;

    97     CxAllocator allocator = list->allocator;

    99     struct cx_linked_list_node *node = cxMalloc(allocator,

   100                                                 sizeof(struct cx_linked_list_node) + list->itemsize);

   101     if (node == NULL)

   102         return 1;

   104     node->next = NULL;

   105     memcpy(node->payload, elem, list->itemsize);

   107     int ret = cx_linked_list_add(

   108             &listdata->begin,

   109             &listdata->end,

   110             offsetof(struct cx_linked_list_node, prev),

   111             offsetof(struct cx_linked_list_node, next),

   112             node

   113     );

   114     if (ret == 0) {

   115         list->size++;

   116         return 0;

   117     } else {

   118         return ret;

   119     }

   120 }

   122 int cx_ll_insert(cx_list *list, size_t index, void *elem) {

   123     cx_linked_list *listdata = (cx_linked_list *) list->listdata;

   124     // TODO: implement using low level API

   125     return 1;

   126 }

   128 void *cx_ll_remove(cx_list *list, size_t index) {

   129     cx_linked_list *listdata = (cx_linked_list *) list->listdata;

   130     // TODO: implement using low level API

   131     return NULL;

   132 }

   134 size_t cx_ll_find(cx_list *list, void *elem) {

   135     cx_linked_list *listdata = (cx_linked_list *) list->listdata;

   136     // TODO: implement using low level API

   137     return 0;

   138 }

   140 void *cx_ll_last(cx_list *list) {

   141     cx_linked_list *listdata = (cx_linked_list *) list->listdata;

   142     struct cx_linked_list_node *last = cx_linked_list_last(

   143             NULL, &listdata->end, offsetof(struct cx_linked_list_node, next));

   144     return &last->payload;

   145 }

   147 cx_list_class cx_linked_list_class = {

   148         cx_ll_add,

   149         cx_ll_insert,

   150         cx_ll_remove,

   151         cx_ll_find,

   152         cx_ll_last

   153 };

   155 CxList cxLinkedListCreate(CxAllocator allocator, CxListComparator comparator, size_t item_size) {

   156     CxLinkedListDesc desc;

   157     desc.item_size = item_size;

   158     desc.begin = NULL;

   159     desc.loc_prev = offsetof(struct cx_linked_list_node, prev);

   160     desc.loc_next = offsetof(struct cx_linked_list_node, next);

   162     return cxLinkedListWrap(allocator, comparator, desc);

   163 }

   165 CxList cxLinkedListWrap(CxAllocator allocator, CxListComparator comparator, CxLinkedListDesc desc) {

   166     CxList list = cxMalloc(allocator, sizeof(list) + sizeof(cx_linked_list));

   167     if (list == NULL)

   168         return NULL;

   170     list->cl = &cx_linked_list_class;

   171     list->data.allocator = allocator;

   172     list->data.cmpfunc = comparator;

   173     list->data.itemsize = desc.item_size;

   174     list->data.capacity = SIZE_MAX;

   176     cx_linked_list *ll = (cx_linked_list *) list->data.listdata;

   177     ll->begin = desc.begin;

   178     ll->loc_prev = desc.loc_prev;

   179     ll->loc_next = desc.loc_next;

   180     cxLinkedListRecalculateSize(list);

   182     return list;

   183 }

   185 size_t cxLinkedListRecalculateSize(CxList list) {

   186     cx_linked_list *ll = (cx_linked_list *) list->data.listdata;

   188     if (ll->begin == NULL) {

   189         list->data.size = 0;

   190         ll->end = NULL;

   191         return 0;

   192     } else {

   193         void *cur = ll->begin;

   194         void *last;

   195         size_t size;

   196         do {

   197             last = cur;

   198             size++;

   199         } while ((cur = *CX_LL_PTR(cur, ll->loc_next)) != NULL);

   200         ll->end = last;

   201         list->data.size = size;

   202         return size;

   203     }

   204 }

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