links_entry
struct links_entry *next;
struct links_entry *previous;
static struct links_entry **buckets;
static struct links_entry *free_list;
struct links_entry *le, **new_buckets;
new_buckets = malloc(new_size * sizeof(struct links_entry *));
memset(new_buckets, 0, new_size * sizeof(struct links_entry *));
le = malloc(sizeof(struct links_entry));