ucx: src/linked_list.c@44efaa54d63d

     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 *newnode) {

    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 = newnode;

    66             return 0;

    67         }

    68     }

    70     void **next = CX_LL_PTR(last, loc_next);

    71     *next = newnode;

    72     if (loc_prev >= 0) {

    73         void **prev = CX_LL_PTR(newnode, 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 } cx_linked_list;

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

    94     cx_linked_list *listdata = list->listdata;

    95     CxAllocator allocator = list->allocator;

    97     struct cx_linked_list_node *node = cxMalloc(allocator,

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

    99     if (node == NULL)

   100         return 1;

   102     node->next = NULL;

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

   105     int ret = cx_linked_list_add(

   106             &listdata->begin,

   107             &listdata->end,

   108             offsetof(struct cx_linked_list_node, prev),

   109             offsetof(struct cx_linked_list_node, next),

   110             node

   111     );

   112     if (ret == 0) {

   113         list->size++;

   114         return 0;

   115     } else {

   116         return ret;

   117     }

   118 }

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

   121     cx_linked_list *listdata = list->listdata;

   122     // TODO: implement using low level API

   123     return 1;

   124 }

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

   127     cx_linked_list *listdata = list->listdata;

   128     // TODO: implement using low level API

   129     return NULL;

   130 }

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

   133     cx_linked_list *listdata = list->listdata;

   134     // TODO: implement using low level API

   135     return 0;

   136 }

   138 void *cx_ll_last(cx_list *list) {

   139     cx_linked_list *ll = list->listdata;

   140     struct cx_linked_list_node *last = cx_linked_list_last(

   141             NULL, &ll->end, offsetof(struct cx_linked_list_node, next));

   142     return &last->payload;

   143 }

   145 cx_list_class cx_linked_list_class = {

   146         cx_ll_add,

   147         cx_ll_insert,

   148         cx_ll_remove,

   149         cx_ll_find,

   150         cx_ll_last

   151 };

   153 CxList cxLinkedListCreate(CxAllocator allocator, CxListComparator comparator, size_t itemsize) {

   154     CxList list = cxMalloc(allocator, sizeof(list));

   155     if (list == NULL)

   156         return NULL;

   158     list->cl = &cx_linked_list_class;

   159     list->data.allocator = allocator;

   160     list->data.cmpfunc = comparator;

   161     list->data.size = 0;

   162     list->data.itemsize = itemsize;

   163     list->data.capacity = SIZE_MAX;

   164     list->data.listdata = cxCalloc(allocator, 1, sizeof(cx_linked_list));

   165     if (list->data.listdata == NULL) {

   166         cxFree(allocator, list);

   167         return NULL;

   168     }

   169 }

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