94 lines
1.7 KiB
C
94 lines
1.7 KiB
C
#include <assert.h>
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#include <stdlib.h>
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#include <string.h>
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#include <xlist.h>
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struct xlist_node *xlist_new(void *data)
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{
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struct xlist_node *list;
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if((list = malloc(sizeof(*list))) == NULL)
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return NULL;
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list->next = list;
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list->prev = list;
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list->data = data;
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return list;
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}
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void xlist_destroy(struct xlist_node *list, xlist_destructor_t destructor)
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{
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struct xlist_node *curr;
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struct xlist_node *next;
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if (! list)
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return;
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curr = list->next;
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while(curr != list) {
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next = curr->next;
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if(destructor)
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destructor(curr->data);
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memset(curr, 0, sizeof(*curr));
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free(curr);
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curr = next;
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}
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memset(list, 0, sizeof(*list));
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free(list);
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}
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void xlist_append_item(struct xlist_node *list, struct xlist_node *item)
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{
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assert(list);
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assert(xlist_empty(item));
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item->next = list;
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item->prev = list->prev;
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list->prev->next = item;
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list->prev = item;
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}
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void xlist_prepend_item(struct xlist_node *list, struct xlist_node *item)
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{
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assert(list);
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assert(xlist_empty(item));
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item->prev = list;
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item->next = list->next;
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list->next->prev = item;
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list->next = item;
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}
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void xlist_remove_item(struct xlist_node *item)
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{
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assert(item);
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item->prev->next = item->next;
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item->next->prev = item->prev;
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item->next = item->prev = item;
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}
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struct xlist_node *xlist_shift(struct xlist_node *list)
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{
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struct xlist_node *item;
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if(!list)
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return NULL;
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if(xlist_empty(list))
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return NULL;
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item = list->next;
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xlist_remove_item(item);
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return item;
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}
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int xlist_empty(const struct xlist_node *list)
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{
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assert(list);
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return list->next == list && list->prev == list;
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}
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size_t xlist_length(const struct xlist_node *list)
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{
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struct xlist_node *curr;
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size_t count = 0;
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for(curr = list->next; curr != list; curr = curr->next)
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count++;
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return count;
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}
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