dahdi-tools/xpp/xtalk/xlist.c

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