timebased_uuid.clj

(import [java.util UUID])

(defn timebased-uuid []
  (let [uuid     (UUID/randomUUID)
        time     (int (/ (System/currentTimeMillis) 1000))
        high     (.getMostSignificantBits uuid)]
    (UUID. 
          (bit-or 
            (bit-and high 0x00000000FFFFFFFF) 
            (bit-shift-left time 32))
          (.getLeastSignificantBits uuid))))