Compile Java using a cached file-manager in Clojure

cached-filemanager.clj

(ns cached-filemanager
  (:import (javax.tools ToolProvider)))

(defn create-compiler[]
  (let [compiler (ToolProvider/getSystemJavaCompiler)
        file-manager (.getStandardFileManager compiler nil nil nil)]
      {:java-compiler compiler
       :file-manager file-manager}))

(defn path-of[file-path]
  (let [fs (java.nio.file.FileSystems/getDefault)]
    (.getPath fs file-path (make-array String 0))))

(defn mk-unit[{:keys [file-manager]} file-path]
  (let [path-array (into-array java.nio.file.Path [(path-of file-path)])
        compilation-unit (.getJavaFileObjects file-manager path-array)]
      {:compilation-unit compilation-unit}))

(defn do-compile[{:keys [file-manager java-compiler
                         task compilation-unit diagnostic]}]
  (let [result (.call task)
        diagnostic-list (.getDiagnostics diagnostic)] ;;javax/tools/Diagnostic
      {:success result
       :errors (map bean diagnostic-list)}))

(defn mk-task [{:keys [file-manager java-compiler
                       compilation-unit diagnostic]}]
  (let [diagnostic (javax.tools.DiagnosticCollector.)
        task (.getTask java-compiler *out* file-manager diagnostic nil nil compilation-unit)]
      {:diagnostic diagnostic
       :task task}))



;; see https://www.logicbig.com/tutorials/core-java-tutorial/java-se-compiler-api/java-compiler-api-intro.html



(comment

  ;; except the first run, this usually takes ~300 ms
  (require '[clj-async-profiler.core :as prof])
  (def compiler (create-compiler))
  (def file-path ".../java-experiments/src/main/java/net/curiosprogrammer/javaexperiments/compiler/JavaCompiler.java")
  (def cu (mk-unit compiler file-path))

  (prof/start)
  ;; YOUR CODE HERE

  (for [x (range 1 2)]
    (time (do-compile (merge compiler cu (mk-task (merge cu compiler))))))


  (prof/stop {:width 2400}))