Method provide

lib/CacheFacade.js:349–361

* Processes the provided identifier. * @template T * @param {string} identifier the cache identifier * @param {Etag | null} etag the etag * @param {(callback: CallbackNormalErrorCache<T>) => void} computer function to compute the value if not cached * @param {CallbackNormalErrorCache<T>} c

(identifier, etag, computer, callback)

	 * @returns {void}
	 */
	provide(identifier, etag, computer, callback) {
		this.get(identifier, etag, (err, cacheEntry) => {
			if (err) return callback(err);
			if (cacheEntry !== undefined) return cacheEntry;
			computer((err, result) => {
				if (err) return callback(err);
				this.store(identifier, etag, result, (err) => {
					if (err) return callback(err);
					callback(null, result);
				});
			});
		});
	}

	/**
	 * Returns promise with the data.