Ruby lang hash resize algorithim

resize_hash

new_size(st_index_t size)
{
    st_index_t i;
    for (i=3; i<31; i++) {
	    if ((st_index_t)(1<<i) > size) return 1<<i;
    }
    #ifndef NOT_RUBY
      rb_raise(rb_eRuntimeError, "st_table too big");
    #endif
    return -1;			/* should raise exception */
}