Method remove

datafusion/execution/src/cache/lru_queue.rs:155–192

Removes a specific entry from the queue, if it exists.

(&mut self, key: &K)

    /// Removes a specific entry from the queue, if it exists.
    pub fn remove(&mut self, key: &K) -> Option<V> {
        if let Some((old_node, old_value)) = self.data.remove(key) {
            let LruNode { key: _, prev, next } = &*old_node.lock();
            match (prev, next) {
                // single node in the queue
                (None, None) => {
                    self.queue.head = None;
                    self.queue.tail = None;
                }
                // removed the head node
                (None, Some(n)) => {
                    let n_strong =
                        n.upgrade().expect("value has been unexpectedly dropped");
                    n_strong.lock().prev = None;
                    self.queue.head = Some(Weak::clone(n));
                }
                // removed the tail node
                (Some(p), None) => {
                    let p_strong =
                        p.upgrade().expect("value has been unexpectedly dropped");
                    p_strong.lock().next = None;
                    self.queue.tail = Some(Weak::clone(p));
                }
                // removed a middle node
                (Some(p), Some(n)) => {
                    let n_strong =
                        n.upgrade().expect("value has been unexpectedly dropped");
                    let p_strong =
                        p.upgrade().expect("value has been unexpectedly dropped");
                    n_strong.lock().prev = Some(Weak::clone(p));
                    p_strong.lock().next = Some(Weak::clone(n));
                }
            };
            Some(old_value)
        } else {
            None
        }
    }

    /// Returns the number of entries in the queue.
    pub fn len(&self) -> usize {