InputStream wrapper which calls given callback after the stream is closed.

cleanup-input-stream.clj

(ns example
  (:import java.io.FilterInputStream))

(defn cleanup-input-stream
  "InputStream wrapper which calls given callback after
  the stream is closed."
  [is cleanup]
  (proxy [FilterInputStream] [is]
    (close []
      (proxy-super close)
      (cleanup))))

(defn input-stream-in-tmp-dir [...]
  (let [dir (create-tmp-dir)
        file (generate-file dir)
        cleanup #(delete-tmp-dir dir)]
    (cleanup-input-stream (input-stream file) cleanup))
    

(with-open [is (input-stream-in-tmp-dir ...)]
  (io/copy is ....))