/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @emails oncall+recoil
 * @flow strict
 * @format
 */
'use strict';

const nullthrows = require('recoil-shared/util/Recoil_nullthrows');

type CacheNode<K, V> = {
  key: K,
  value: V,
  left: ?CacheNode<K, V>,
  right: ?CacheNode<K, V>,
};
type Options<K> = {
  maxSize: number,
  mapKey?: (K) => mixed,
};
declare class LRUCache<K = mixed, V = mixed> {
  _maxSize: number,
  _size: number,
  _head: ?CacheNode<K, V>,
  _tail: ?CacheNode<K, V>,
  _map: Map<mixed, CacheNode<K, V>>,
  _keyMapper: (K) => mixed,
  constructor(options: Options<K>): any,
  head(): ?CacheNode<K, V>,
  tail(): ?CacheNode<K, V>,
  size(): number,
  maxSize(): number,
  has(key: K): boolean,
  get(key: K): ?V,
  set(key: K, val: V): void,
  _maybeDeleteLRU(): any,
  deleteLru(): void,
  delete(key: K): void,
  clear(): void,
}
module.exports = {
  LRUCache
};