opnet/src/cache/LRUCaching.ts

The perfect library for building Bitcoin-based applications.

export class LRUCache<K, V> {
    private readonly cache: Map<K, V>;
    private readonly maxSize: number;

    constructor(maxSize: number) {
        this.cache = new Map();
        this.maxSize = maxSize;
    }

    public get(key: K): V | undefined {
        const value = this.cache.get(key);
        if (value !== undefined) {
            this.cache.delete(key);
            this.cache.set(key, value);
        }
        return value;
    }

    public set(key: K, value: V): void {
        if (this.cache.has(key)) {
            this.cache.delete(key);
        } else if (this.cache.size >= this.maxSize) {
            const firstKey = this.cache.keys().next().value;
            if (firstKey !== undefined) {
                this.cache.delete(firstKey);
            }
        }
        this.cache.set(key, value);
    }
}