encode and decode files as kroki url diagrams https://kroki.io/#try

kroki-read.bb

#!/usr/local/bin/bb

(import '[java.io ByteArrayOutputStream])
(import '[java.util Base64]) ;
(import '[java.util.zip Inflater]) ;

(defn uncompress [source-bytes]
  (let [inflater (doto (Inflater.)
                   (.setInput source-bytes))
        outputStream (new ByteArrayOutputStream (count source-bytes))
        buffer (byte-array 1024)]
    (while (not (.finished inflater))
      (let [c (.inflate inflater buffer)]
        (.write outputStream buffer 0 c)))
    (.close outputStream)
    (str outputStream)))

(defn decode [encoded]
  (->
    (Base64/getUrlDecoder)
    (.decode encoded)
    uncompress))

; invoke with a kroki url. optional second arg can be file to print to
(let [[url out-file] *command-line-args*
      contents
      (decode (last (clojure.string/split url #"/")))]
  (if out-file
    (spit out-file contents)
    (println contents)))

 

kroki-url.bb

#!/usr/local/bin/bb

(import '[java.io ByteArrayOutputStream])
(import '[java.util Base64]) ;
(import '[java.util.zip Deflater]) ;

(defn compress [source]
  (let [deflater (doto (Deflater. (Deflater/BEST_COMPRESSION))
                   (.setInput source)
                   (.finish))
        buffer (byte-array 2048)
        compressed-length (.deflate deflater buffer)
        result (byte-array compressed-length)]
    (System/arraycopy buffer 0 result 0 compressed-length)
    result))

(defn encode [decoded]
  (-> 
    (Base64/getUrlEncoder)
    (.encodeToString (compress (.getBytes decoded)))))

;e.g. kroki-url.bb test.puml c4plantuml
(println
  (str "https://kroki.io/" (second *command-line-args*) "/svg/"
    (encode (slurp (first *command-line-args*)))))