Chunked upload

(defn upload-chunked
  [params]
  (let [headers (:headers params)
        content-range (rest (re-matches #"(\d+)-(\d+)\/(\d+)" (get headers "content-range")))
        content-length  (parse-int (get headers "content-length"))
        [start end total] (map parse-int content-range)
        body-stream (:body params)
        file-name (get headers "x-file-name" "")
        hash (sha1-str (str file-name total))
        dest-path (files/file-path (uploads-path) (files/make-new-name hash file-name))
        file (io/file dest-path)
        file-size (.length file)
        stream (io/output-stream dest-path :append true)]
    (if (= (+ 1 end) file-size)
      (do
        (dispose-stream stream)
        (response/created (result/success)))
      (if (not (= start file-size))
        (do
          (dispose-stream stream)
          (io/delete-file dest-path true)
          (response/bad-request (result/failure "start != file-size")))
        (try
          (io/copy body-stream stream)
          (if (>= (+ start content-length) total)
            (do
              (dispose-stream stream)
              (response/ok (result/success)))
            (response/created))
          (catch Exception e
            (dispose-stream stream)
            (response/bad-request (result/failure "Chunked upload has failed!"))))))))