automate-electron-ipc/dist/cache.js

Node library for automating the generation of IPC components for Electron apps.

/*
 *   Apache License 2.0
 *
 *   Copyright (c) 2024, Mattias Aabmets
 *
 *   The contents of this file are subject to the terms and conditions defined in the License.
 *   You may not use, modify, or distribute this file except in compliance with the License.
 *
 *   SPDX-License-Identifier: Apache-2.0
 */
/**
 * LRUCache is a Least Recently Used (LRU) cache that can be instantiated as a singleton
 * with a specified identifier, allowing retrieval of the same instance across the application
 * when provided with the same ID. It manages a limited number of entries and evicts the least
 * recently accessed items when the limit is reached. When the limit is set to 0, the cache size
 * is unlimited.
 *
 * Methods:
 * - getInstance(id: string, limit?: number): Returns an instance associated with the given ID.
 * - get(key: unknown): [boolean, unknown] - Retrieves a value by key if present, marking it as recently used.
 * - put(key: unknown, value: unknown): void - Inserts a key-value pair, evicting the least recently used item if necessary.
 */
export class LRUCache {
    static instances = new Map();
    cache;
    limit;
    constructor(limit = 0) {
        this.cache = new Map();
        this.limit = limit;
    }
    static getInstance(id, limit = 0) {
        if (!LRUCache.instances.has(id)) {
            LRUCache.instances.set(id, new LRUCache(limit));
        }
        return LRUCache.instances.get(id);
    }
    get(key) {
        if (!this.cache.has(key)) {
            return [false, null];
        }
        const value = this.cache.get(key);
        this.cache.delete(key);
        this.cache.set(key, value);
        return [true, value];
    }
    put(key, value) {
        if (this.cache.has(key)) {
            this.cache.delete(key);
        }
        else if (this.limit > 0 && this.cache.size >= this.limit) {
            const leastRecentlyUsedKey = this.cache.keys().next().value;
            this.cache.delete(leastRecentlyUsedKey);
        }
        this.cache.set(key, value);
    }
}
export default { LRUCache };