Native Datalevin

Datalevin can be compiled as a GraalVM native image.

Build Native Datalevin

Assuming that you can build JVM Datalevin already, i.e. you have JDK and lein, here are the steps to build native Datalevin binary on your platform.

Linux/MacOS

1. Install GraalVM
2. Intsall GraalVM native image
3. Run script/compile.

If the compilation is successful, two binaries will appear in this directory: dtlv and dtlv-test. The former is the Datalevin command line shell, and the latter runs all the Datalevin tests in native mode. These are standalone executable that you can immediately run.

Windows

Same as the above, except to run script/compile.bat instead in step 3.

If the build is successful, you will get dtlv.exe and dtlv-test.exe.

Compiling Datalevin Dependency to Native Image

If your application depends on Datalevin library, and you want to compile your application into a GraalVM native image, you need to use org.clojars.huahaiy/datalevin-native as the dependency, instead of datalevin/datalevin.

datalevin-native includes GraalVM specific native code that are pre-compiled for various platforms.

Like all Clojure applications, class initialization needs to be done at native image build time, otherwise, native image build will fail due to link errors. During the native image build time, our class initialization code extracts native libraries from the datalevin-native jar and put them in the GraalVM's default CLibraryPath for the platform (e.g. ${GRAALVM_HOME}/lib/svm/clibraries/linux-amd64/). The files will be deleted on JVM exit.

If you are uncomfortable with writing the default location or lack the write permission for that directory, you can set an environment variable DTLV_LIB_EXTRACT_DIR in the shell doing the native image build, and the native libraries will then be put there instead. If so, you must also add -H:CLibraryPath=${DTLV_LIB_EXTRACT_DIR} option in your native image build command line. The directory referred to by the environment variable must exist and is writable.

Once built, Datalevin's native dependencies are linked into your image statically.

For CI/CD, you may want to consult our Github Action (for Linux/MacOS) and Appveoyor (for Windows) yaml files for examples.