import { FetchingFunction, CachableValue } from 'cachette';
/**
 * The Cache class provides caching capabilities that can be used across your integration.
 * It can be backed by a Redis instance (by passing it a URL to the instance) or a local cache.
 *
 * @see {@link Cache.create}
 */
export declare class Cache {
    private cacheInstance;
    private constructor();
    /**
     * Get or fetch a value
     *
     * @param key     The key of the value to get
     * @param ttl     The time to live of the value in seconds.
     * @param fetchFn The function that can retrieve the original value
     * @param lockTtl Global distributed lock TTL (in seconds) protecting fetching.
     *                If undefined, 0 or falsy, locking is not preformed
     * @param shouldCacheError A callback being passed errors, controlling whether
     *                         to cache or not errors. Defaults to never cache.
     *
     * @returns       The cached or fetched value
     */
    getOrFetchValue<F extends FetchingFunction = FetchingFunction>(key: string, ttl: number, fetcher: F, lockTtl?: number, shouldCacheError?: (err: Error) => boolean): Promise<ReturnType<F>>;
    /**
     * Get a value from the cache.
     *
     * @param key   The key of the value to get.
     *
     * @return      The value associated with the key, or undefined if
     *              no such value exists.
     */
    getValue(key: string): Promise<CachableValue>;
    /**
     * Set a value in the cache.
     *
     * @param key        The key of the value to set.
     * @param value      The value to set.
     * @param ttl        The time to live of the value in seconds.
     *                   By default, the value will not expire
     *
     * @return true if the value was stored, false otherwise.
     */
    setValue(key: string, value: CachableValue, ttl?: number): Promise<boolean>;
    /**
     * Delete a value from the cache.
     * @param key — The key of the value to set.
     */
    delValue(key: string): Promise<void>;
    /**
     * Get the TTL of an entry, in ms
     *
     * @param key   The key of the entry whose ttl to retrieve
     *
     * @return      The remaining TTL on the entry, in ms.
     *              undefined if the entry does not exist.
     *              0 if the entry does not expire.
     */
    getTtl(key: string): Promise<number | undefined>;
    /**
     * Initializes a Cache backed by the Redis instance at the provided url if present, or a LocalCache otherwise.
     *
     * @param redisUrl - The redis url to connect to (optional).
     * @returns A cache instance.
     */
    static create(redisUrl?: string): Cache;
}