Native Clojure with GraalVM

转自：https://www.innoq.com/en/blog/native-clojure-and-graalvm/

GraalVM is a fascinating piece of technology. This newly-released just-in-time compiler allows efficient execution and interoperability between various programming languages on top of the JVM. Its impact on the execution speed is stunning. Benchmarks comparing Graal-based TruffleRuby to other Ruby implementations give us a hint of Graal’s potential. Speed benefits aside, the new compiler also allows us to translate our JVM bytecode into small self-contained native binaries.

And that’s just the tip of the iceberg. Needless to say, I am excited about it.

Minimal viable native binary

In a recent article my workmate Ruben Wagner discussed how Graal allows us to shrink Docker containers running our Java applications. Not only did he reduce the size of his images to 10 MB, but also made them consume less than a megabyte of RAM at runtime. On top of that, Graal allowed him to significantly speed up the startup of his Java applications.

Encouraged by his experiments, I attempted to adapt his approach to another JVM-based language, albeit a far more dynamic one: Clojure. Just like Java, this modern Lisp can be compiled ahead-of-time to *.class files consisting of JVM bytecode. Consider the simple namespace below.

(ns io.innoq.clojure.hello
  (:gen-class))

(defn -main []
  (println "