impl UserRssItemsFilter for FilterByLastRequestData {
    fn filter(&self, user: i64, rep: &String, item: &RssItem) -> bool {
        let key = format!("{} {}", user, rep);
        let r = self.last_request_cache.write(|db| {
            let last_request: DateTime<Utc> = if let Some(last_request_str) = db.get(&key) {
                DateTime::parse_from_rfc2822(&last_request_str).unwrap().into()
            } else {
                Utc::now() - Duration::days(2)
            };
            if last_request < item.created_date {
                db.insert(key, item.created_date.to_rfc2822());
                true
            } else {
                false
            }
        }).unwrap();
        self.last_request_cache.save().unwrap();
        r
    }
}

impl UserRssItemsFilter for FilterByLastRequestData {
    fn filter(&self, user: i64, rep: &String, item: &RssItem) -> bool {
        let key = format!("{} {}", user, rep);
        let last_request = match  self.last_request_cache.read(|db| {
            match db.get(&key) {
                Some(v) => Some(DateTime::parse_from_rfc2822(v).unwrap().into()),
                None => None
            }
        }).unwrap() {
            Some(v) => v,
            None => Utc::now() - Duration::days(2)
        };

        if last_request < item.created_date {
            self.last_request_cache.write(|db| {
                db.insert(key, item.created_date.to_rfc2822());
            }).unwrap();
            self.last_request_cache.save().unwrap();
            true
        } else {
            false
        }
    }
}