lfu_other

lfu_other.rs

   // current cache length
    pub fn len(&self) -> usize {
        self.by_key.len()
    }

    // check if current cache is empty
    pub fn is_empty(&self) -> bool {
        self.by_key.is_empty()
    }

    // current cache capacity
    pub fn capacity(&self) -> usize {
        self.capacity
    }

    // clean up the cache
    pub fn clear(&mut self) {
        self.by_key.clear();
        self.freq_node.clear();
    }