leveldb_as_jsondb.clj

;; db => https://github.com/Factual/clj-leveldb
;; json => https://github.com/clojure/data.json
(def json-db (atom nil))

(defn val-encoder [m]
  (let [s (json/write-str m)]
    (byte-array (map byte s))))
    
(defn val-decoder [ba]
  (let [s (byte-streams/to-string ba)
        m (json/read-str s)
        unzip (juxt (partial map (comp keyword first))
                    (partial map second))]
    (apply zipmap (unzip m))))

(reset! json-db (db/create-db "json_db" {:key-decoder byte-streams/to-string
                                          :val-encoder val-encoder
                                          :val-decoder val-decoder}))

(db/put @json-db "a" {:name "unko" :data [1 2 3]})
(db/get @json-db "a") ;; => {:name "unko", :data [1 2 3]}