/*C arrays are indexed starting at 0. */
void init_skipset(skipset** ss ) {
*ss = malloc(sizeof(skipset));
(*ss)->item = NULL;
(*ss)->level = 0;
int i = HEADER;
(*ss)->header = make_skipnode((*ss), MAX_LEVEL, &i, sizeof(int));
}
skiplist make_skiplist(size_t data_sz)
{
skiplist s;
s.head = make_skipnode(-1L, SKIPLIST_MAX_LEVEL, 0);
s.data_sz = data_sz;
return s;
}
void
insert(skiplist sk, unsigned long key, void* data, RNG* rng)
{
int insertion_level = nodeLevel(rng);
skipnode* new_node = make_skipnode(key, insertion_level, sk.data_sz);
memcpy(data, ((char*) new_node - sk.data_sz), sk.data_sz);
insert_node(sk.head, new_node, insertion_level);
}
/*an array of pointers to the nodes that must be updated. */
void insert_skipnode(skipset* ss, const void* key, int key_sz,
int (*compare_keys)(const void* key1, const void* key2)) {
if(contains_skipnode(ss, key, compare_keys) != NULL) /*no duplicates allowed in set*/
return;
int l = random_level(); /*level of new node*/
if(l > ss->level)
ss->level = l;
insert_node(ss->header, make_skipnode(ss, l, key, key_sz), l, compare_keys);
}
