gzip_file.clj

(defn gzip-file
  ([path]
     (gzip-file path ".gz"))
  ([path suffix]
     (let [bufsize 8192
           buf (make-array Byte/TYPE bufsize)]
       (with-open [rdr (FileInputStream. (File. path))
                   wtr (GZIPOutputStream.
                        (FileOutputStream.
                         (format "%s%s" path suffix)))]
         (loop [len (.read rdr buf)]
           (when (pos? len)
             (.write wtr buf 0 len)
             (recur (.read rdr buf))))))))