int skiplist_delete(skiplist *list, int key)
{
int i;
snode *update[SKIPLIST_MAX_LEVEL + 1];
snode *x = list->header;
for (i = list->level; i >= 1; i--) {
while (x->forward[i]->key < key)
x = x->forward[i];
update[i] = x;
}
x = x->forward[1];
if (x->key == key) {
for (i = 1; i <= list->level; i++) {
if (update[i]->forward[i] != x)
break;
update[i]->forward[1] = x->forward[i];
}
skiplist_node_free(x);
while (list->level > 1 && list->header->forward[list->level] == list->header)
list->level--;
return 0;
}
return 1;
}
int skiplist_delete_raw(SkipList *list, unsigned char *key, int(* cmp)(unsigned char *, unsigned char *), void(* del)(void *))
{
int i;
Node *update[SKIPLIST_MAX_LEVEL + 1];
Node *x = list->header;
for(i = list->level; i >= 1; i--) {
while(cmp(x->forward[i]->key, key) < 0) {
x = x->forward[i];
}
update[i] = x;
}
x = x->forward[1];
if (cmp(x->key, key) == 0) {
for (i = 1; i <= list->level; i++) {
if (update[i]->forward[i] != x) {
break;
}
update[i]->forward[i] = x->forward[i];
}
skiplist_node_free(x, del);
while(list->level > 1 && list->header->forward[list->level] == list->header)
list->level--;
return 0;
}
return 1;
}
