Track time spent in app: network-efficient case tracking last active timestamp

ui_core.rs

lazy_static! {
    static ref LAST_USER_ACTION_UNIX_TIMESTAMP: AtomicI64 = AtomicI64::new(0);
}

pub fn last_active_timestamp() -> i64 {
    LAST_USER_ACTION_UNIX_TIMESTAMP.load(Ordering::SeqCst)
}

// Call this on app start and on every user app active action, e.g. every keystroke
pub fn record_last_active_timestamp() {
    LAST_USER_ACTION_UNIX_TIMESTAMP.fetch_max(Utc::now().timestamp(), Ordering::SeqCst);
}