fixed-capacity-cache

A tiny, 0-dependency, npm library containing a cache class that stores a fixed number of items.

If the cache is configured to only store three items when the fourth item is stored the oldest* item is silently removed.

*oldest is defined by the item which is either gotten or set least recently.

Usage

TypeScript

const cacheCapacity = 3;

const key = 1;
const value = "value1";

const cache = new FixedCapacityCache<number, string>(cacheCapacity);
cache.set(key, value);

const retrievedValue = cache.get(key);

API

class FixedCapacityCache<TKey, TValue> {
  readonly maxSize: number;
  /**
   * A cache which only stores the most recent N items.
   * @param maxSize The maximum number of items to store in the cache.
   */
  constructor(maxSize: number);
  /**
   * Gets the value associated with the given key.
   * @param key The key to get the value for.
   * @returns The value for the given key, or undefined if the key is not in the cache.
   */
  get(key: TKey): TValue | undefined;
  /**
   * Adds a value to the cache.
   * This will remove an old value if the cache is full.
   * @param key The key to associate with the given value.
   * @param value The value to associate with the given key.
   * @returns The new value associated with the given key.
   */
  set(key: TKey, value: TValue): TValue;
  /**
   * Removes the value associated with the given key.
   * @param key The key of the value to remove.
   */
  delete(key: TKey): void;
  /**
   * Returns the number of items in the cache.
   * @returns The number of items in the cache.
   */
  size(): number;
  /**
   * Clears the cache.
   */
  clear(): void;
}

Building the library yourself

npm ci
npm build

License

fixed-capacity-cache is licensed under the ISC License.