remember.js

Cache.remember = function (key, lifetime, callback) {
	return Promise.try(() => {
		return memcached.getAsync(key);
	}).then((value) => {
		if (value !== undefined) {
			return value;
		} else {
			return Promise.try(() => {
				return callback()
			}).then((value) => {
				return memcached.setAsync(key, value, lifetime); 
			}).then(() => {
				return value;
			})
		}
	})
};