/*
* dlist_qsort_3:
*
* recursive function that implements quicksort with a three-way partition
* on an array of slist_node_t structures.
*/
static void dlist_qsort_3(dlist_node_t **a, dlist_cmp_t cmp, int l, int r)
{
dlist_node_t *c;
int i, lt, gt, rc;
if(l >= r)
return;
c = a[l];
lt = l;
gt = r;
i = l;
while(i <= gt)
{
rc = a[i]->item != c->item ? cmp(a[i]->item, c->item) : 0;
if(rc < 0)
dlist_swap(a, lt++, i++);
else if(rc > 0)
dlist_swap(a, i, gt--);
else
i++;
}
dlist_qsort_3(a, cmp, l, lt-1);
dlist_qsort_3(a, cmp, gt+1, r);
return;
}
void
dlist_reverse(dlist *l)
{
dlist *iter1 = dlist_first(l),
*iter2 = dlist_last(l);
while(iter1 != iter2) {
dlist_swap(iter1, iter2);
if(iter1->next == iter2)
break;
iter1 = iter1->next;
iter2 = iter2->prev;
}
}
void
dlist_sort(dlist *l, dlist_cmp_func cmp, void *data)
{
dlist *start = dlist_first(l);
while(start) {
dlist *iter = start;
start = 0;
while(iter) {
if(iter->next && cmp(iter, iter->next, data) == 1) {
dlist_swap(iter, iter->next);
if(! start)
start = iter->prev;
}
iter = iter->next;
}
}
}
