universe@398: /*
universe@398:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
universe@398:  *
universe@398:  * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
universe@398:  *
universe@398:  * Redistribution and use in source and binary forms, with or without
universe@398:  * modification, are permitted provided that the following conditions are met:
universe@398:  *
universe@398:  *   1. Redistributions of source code must retain the above copyright
universe@398:  *      notice, this list of conditions and the following disclaimer.
universe@398:  *
universe@398:  *   2. Redistributions in binary form must reproduce the above copyright
universe@398:  *      notice, this list of conditions and the following disclaimer in the
universe@398:  *      documentation and/or other materials provided with the distribution.
universe@398:  *
universe@398:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
universe@398:  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
universe@398:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
universe@398:  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
universe@398:  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
universe@398:  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
universe@398:  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
universe@398:  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
universe@398:  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
universe@398:  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
universe@398:  * POSSIBILITY OF SUCH DAMAGE.
universe@398:  */
universe@398: 
universe@398: #include "cx/linked_list.h"
universe@401: #include <stdint.h>
universe@401: #include <string.h>
universe@398: 
universe@398: /* LOW LEVEL LINKED LIST FUNCTIONS */
universe@398: 
universe@398: #define CX_LL_PTR(cur, off) ((void**)(((char*)cur)+off))
universe@398: 
universe@438: void *cx_linked_list_at(void *start, size_t start_index, ptrdiff_t loc_advance, size_t index) {
universe@438:     size_t i = start_index;
universe@446:     void *cur = start;
universe@438:     while (i != index && cur != NULL) {
universe@438:         cur = *CX_LL_PTR(cur, loc_advance);
universe@438:         i < index ? i++ : i--;
universe@438:     }
universe@438:     return cur;
universe@438: }
universe@438: 
universe@400: void *cx_linked_list_last(void **begin, void **end, ptrdiff_t loc_next) {
universe@398:     if (end != NULL) {
universe@398:         return *end;
universe@398:     } else {
universe@398:         if (begin == NULL || *begin == NULL)
universe@398:             return NULL;
universe@398: 
universe@398:         void *cur = *begin;
universe@398:         void *last;
universe@398:         do {
universe@398:             last = cur;
universe@398:         } while ((cur = *CX_LL_PTR(cur, loc_next)) != NULL);
universe@398: 
universe@398:         return last;
universe@398:     }
universe@398: }
universe@398: 
universe@406: int cx_linked_list_add(void **begin, void **end, ptrdiff_t loc_prev, ptrdiff_t loc_next, void *new_node) {
universe@398:     void *last = cx_linked_list_last(begin, end, loc_next);
universe@398:     if (last == NULL) {
universe@398:         if (begin == NULL) {
universe@428:             // no current list and no begin ptr to write to - we don't find something to append to
universe@398:             return 1;
universe@398:         } else {
universe@428:             // start fresh list
universe@406:             *begin = new_node;
universe@398:         }
universe@428:     } else {
universe@428:         // if there is a last node, update its next pointer
universe@428:         void **next = CX_LL_PTR(last, loc_next);
universe@428:         *next = new_node;
universe@398:     }
universe@398: 
universe@428:     // if there is an end pointer, update it
universe@408:     if (end != NULL) {
universe@408:         *end = cx_linked_list_last(&new_node, NULL, loc_next);
universe@408:     }
universe@428: 
universe@428:     // if the nodes use a prev pointer, update it
universe@398:     if (loc_prev >= 0) {
universe@406:         void **prev = CX_LL_PTR(new_node, loc_prev);
universe@398:         *prev = last;
universe@398:     }
universe@398: 
universe@398:     return 0;
universe@398: }
universe@398: 
universe@398: /* HIGH LEVEL LINKED LIST IMPLEMENTATION */
universe@398: 
universe@447: typedef struct cx_linked_list_node cx_linked_list_node;
universe@447: struct cx_linked_list_node {
universe@447:     cx_linked_list_node *prev;
universe@447:     cx_linked_list_node *next;
universe@403:     char payload[];
universe@447: };
universe@402: 
universe@446: #define CX_LL_LOC_PREV offsetof(cx_linked_list_node, prev)
universe@446: #define CX_LL_LOC_NEXT offsetof(cx_linked_list_node, next)
universe@439: 
universe@398: typedef struct {
universe@435:     cx_list_s base;
universe@446:     cx_linked_list_node *begin;
universe@446:     cx_linked_list_node *end;
universe@398: } cx_linked_list;
universe@398: 
universe@438: static int cx_ll_add(cx_list_s *list, void *elem) {
universe@437:     cx_linked_list *ll = (cx_linked_list *) list;
universe@398: 
universe@446:     cx_linked_list_node *node = cxMalloc(list->allocator,
universe@446:                                          sizeof(cx_linked_list_node) + list->itemsize);
universe@398:     if (node == NULL)
universe@398:         return 1;
universe@398: 
universe@406:     memcpy(node->payload, elem, list->itemsize);
universe@446:     node->next = NULL;
universe@399: 
universe@446:     if (ll->begin == NULL) {
universe@446:         ll->begin = ll->end = node;
universe@398:     } else {
universe@446:         // per contract of this linked list we know that end must be non-null
universe@446:         ll->end->next = node;
universe@446:         ll->end = node;
universe@398:     }
universe@446:     list->size++;
universe@446: 
universe@446:     return 0;
universe@398: }
universe@398: 
universe@447: static cx_linked_list_node *cx_ll_node_at(cx_linked_list* list, size_t index) {
universe@447:     if (index >= list->base.size) {
universe@447:         return NULL;
universe@447:     } else if (index > list->base.size / 2) {
universe@447:         return cx_linked_list_at(list->end, list->base.size, CX_LL_LOC_PREV, index);
universe@447:     } else {
universe@447:         return cx_linked_list_at(list->begin, 0, CX_LL_LOC_NEXT, index);
universe@447:     }
universe@447: }
universe@447: 
universe@438: static int cx_ll_insert(cx_list_s *list, size_t index, void *elem) {
universe@437:     cx_linked_list *ll = (cx_linked_list *) list;
universe@398:     // TODO: implement using low level API
universe@398:     return 1;
universe@398: }
universe@398: 
universe@438: static int cx_ll_remove(cx_list_s *list, size_t index) {
universe@447:     cx_linked_list *ll = (cx_linked_list *) list;
universe@447:     cx_linked_list_node *node = cx_ll_node_at(ll, index);
universe@447: 
universe@447:     // out-of-bounds check
universe@447:     if (node == NULL) return 1;
universe@447: 
universe@447:     // change left side connection
universe@447:     if (node->prev == NULL) {
universe@447:         ll->begin = node->next;
universe@447:     } else {
universe@447:         node->prev->next = node->next;
universe@438:     }
universe@447: 
universe@447:     // change right side connection
universe@447:     if (node->next == NULL) {
universe@447:         ll->end = node->prev;
universe@447:     } else {
universe@447:         node->next->prev = node->prev;
universe@447:     }
universe@447: 
universe@447:     // adjust size
universe@447:     list->size--;
universe@447: 
universe@447:     // free and return
universe@447:     cxFree(list->allocator, node);
universe@447: 
universe@438:     return 0;
universe@398: }
universe@398: 
universe@439: static void *cx_ll_at(cx_list_s *list, size_t index) {
universe@439:     cx_linked_list *ll = (cx_linked_list *) list;
universe@447:     cx_linked_list_node *node = cx_ll_node_at(ll, index);
universe@440:     return node == NULL ? NULL : &node->payload;
universe@439: }
universe@439: 
universe@438: static size_t cx_ll_find(cx_list_s *list, void *elem) {
universe@437:     CxListComparator cmp = list->cmpfunc;
universe@437:     cx_linked_list *ll = (cx_linked_list *) list;
universe@437: 
universe@437:     size_t index;
universe@446:     cx_linked_list_node *node = ll->begin;
universe@446:     for (index = 0; index < list->size; index++) {
universe@446:         void *current = node->payload;
universe@437:         if (cmp(current, elem) == 0) {
universe@437:             return index;
universe@437:         }
universe@437:         node = node->next;
universe@437:     }
universe@437:     return index;
universe@398: }
universe@398: 
universe@438: static void *cx_ll_last(cx_list_s *list) {
universe@439:     cx_linked_list *ll = (cx_linked_list *) list;
universe@446:     cx_linked_list_node *last = cx_linked_list_last(NULL, (void **) &ll->end, CX_LL_LOC_NEXT);
universe@404:     return &last->payload;
universe@404: }
universe@398: 
universe@398: cx_list_class cx_linked_list_class = {
universe@398:         cx_ll_add,
universe@398:         cx_ll_insert,
universe@398:         cx_ll_remove,
universe@439:         cx_ll_at,
universe@404:         cx_ll_find,
universe@404:         cx_ll_last
universe@398: };
universe@398: 
universe@406: CxList cxLinkedListCreate(CxAllocator allocator, CxListComparator comparator, size_t item_size) {
universe@446:     cx_linked_list *list = cxMalloc(allocator, sizeof(cx_linked_list));
universe@398:     if (list == NULL)
universe@398:         return NULL;
universe@398: 
universe@435:     list->base.cl = &cx_linked_list_class;
universe@435:     list->base.allocator = allocator;
universe@435:     list->base.cmpfunc = comparator;
universe@435:     list->base.itemsize = item_size;
universe@435:     list->base.capacity = SIZE_MAX;
universe@441:     list->base.size = 0;
universe@406: 
universe@435:     list->begin = NULL;
universe@441:     list->end = NULL;
universe@406: 
universe@441:     return (CxList) list;
universe@406: }
universe@406: 
universe@409: void cxLinkedListDestroy(CxList list) {
universe@446:     cx_linked_list *ll = (cx_linked_list *) list;
universe@436: 
universe@446:     cx_linked_list_node *node = ll->begin;
universe@436:     while (node) {
universe@446:         void *next = node->next;
universe@436:         cxFree(list->allocator, node);
universe@436:         node = next;
universe@436:     }
universe@436: 
universe@435:     cxFree(list->allocator, list);
universe@409: }
universe@409: 
universe@406: size_t cxLinkedListRecalculateSize(CxList list) {
universe@435:     cx_linked_list *ll = (cx_linked_list *) list;
universe@406: 
universe@406:     if (ll->begin == NULL) {
universe@435:         ll->base.size = 0;
universe@407:         ll->end = NULL;
universe@406:         return 0;
universe@406:     } else {
universe@446:         cx_linked_list_node *cur = ll->begin;
universe@446:         cx_linked_list_node *last;
universe@435:         size_t size = 0;
universe@406:         do {
universe@407:             last = cur;
universe@406:             size++;
universe@446:         } while ((cur = cur->next) != NULL);
universe@407:         ll->end = last;
universe@435:         ll->base.size = size;
universe@406:         return size;
universe@398:     }
universe@406: }