eslint-plugin-svelte/lib/utils/cache.js

ESLint plugin for Svelte using AST

/**
 * Simple cache manager.
 *
 * refer: https://github.com/mysticatea/eslint-plugin-node/blob/f45c6149be7235c0f7422d1179c25726afeecd83/lib/util/cache.js
 */
const SKIP_TIME = 5000;
/**
 * The cache will dispose of each value if the value has not been accessed
 * during 5 seconds.
 * @returns getter and setter ofr the cache.
 */
export function createCache() {
    const map = new Map();
    /**
     * Get the cached value of the given key.
     * @param key The key to get.
     * @returns The cached value or null.
     */
    function get(key) {
        const entry = map.get(key);
        const now = Date.now();
        if (entry) {
            if (entry.expire > now) {
                entry.expire = now + SKIP_TIME;
                return entry.value;
            }
            map.delete(key);
        }
        return null;
    }
    /**
     * Set the value of the given key.
     * @param key The key to set.
     * @param value The value to set.
     * @returns
     */
    function set(key, value) {
        const entry = map.get(key);
        const expire = Date.now() + SKIP_TIME;
        if (entry) {
            entry.value = value;
            entry.expire = expire;
        }
        else {
            map.set(key, { value, expire });
        }
    }
    return { get, set };
}