Bring Powersort to Java

Gradle

Setup

Commandline

Check which Java toolchains can be found by Gradle:

./gradlew javaToolchains

• shell.nix -> broken (as well for gradle javaToolchains
• shell1.nix -> works 🥳
• shell2.nix -> broken (as well for gradle javaToolchains)
• shell3.nix -> works 🥳
• shell4.nix -> works 🥳

This should include version >= 17, e.g.:

 + N/A JDK 23-ga
     | Location:           /nix/store/48290hnlb13xmwjw9y16a1s785993bv7-openjdk-23-ga/lib/openjdk
     | Language Version:   23
     | Vendor:             N/A
     | Architecture:       amd64
     | Is JDK:             true
     | Detected by:        Current JVM

IntelliJ

Open issue: gradle's toolchain support does not work with IntelliJ

• shell.nix
  • Solution from 2022 did no longer work: https://github.com/NixOS/nixpkgs/issues/207153#issue-1506967648
• shell1.nix
  • Instead, we found this: https://discourse.nixos.org/t/overriding-the-jdk-for-gradle-in-a-nix-flake/36541/2
• shell2.nix
  • Another approach - which did no longer work! https://github.com/utybo/Tegral/blob/main/shell.nix
• shell3.nix
  • This works with JDK 21 🥳
  • STRG ALT SHIFT s -> SDK -> add JDK ->
    • home path: /usr/lib/openjdk
    • name: usr-lib-jdk
  • STRG ALT s -> build tools -> gradle ->
    • local installation: /usr/lib/gradle
    • Gradle JVM: usr-lib-jdk
• shell4.nix
  • This works with JDK23 🚀

Tasks

List all Gradle tasks which can be run:

./gradlew tasks

This can also be done graphically in IntelliJ:

Test Cases

Run the task "test":

./gradlew test

TimSort

Imported from

• src/java.base/share/classes/java/util/TimSort.java
• src/java.base/share/classes/java/util/ComparableTimSort.java