buildSrc/src/main/java/dx/DexMergerTask.java

// Copyright (c) 2019, the R8 project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
package dx;

import com.google.common.base.Optional;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import javax.inject.Inject;
import org.gradle.api.DefaultTask;
import org.gradle.api.file.FileCollection;
import org.gradle.api.file.RegularFileProperty;
import org.gradle.api.provider.SetProperty;
import org.gradle.api.tasks.InputFile;
import org.gradle.api.tasks.InputFiles;
import org.gradle.api.tasks.OutputFile;
import org.gradle.api.tasks.TaskAction;
import org.gradle.process.JavaForkOptions;
import org.gradle.workers.WorkAction;
import org.gradle.workers.WorkParameters;
import org.gradle.workers.WorkQueue;
import org.gradle.workers.WorkerExecutor;
import utils.Utils;

public class DexMergerTask extends DefaultTask {

  private final WorkerExecutor workerExecutor;

  private FileCollection source;
  private File destination;
  private Optional<File> dexMergerExecutable = Optional.absent(); // Worker API cannot handle null.

  @Inject
  public DexMergerTask(WorkerExecutor workerExecutor) {
    this.workerExecutor = workerExecutor;
  }

  @InputFiles
  public FileCollection getSource() {
    return source;
  }

  public void setSource(FileCollection source) {
    this.source = source;
  }

  @OutputFile
  public File getDestination() {
    return destination;
  }

  public void setDestination(File destination) {
    this.destination = destination;
  }

  @InputFile
  @org.gradle.api.tasks.Optional
  public File getDexMergerExecutable() {
    return dexMergerExecutable.orNull();
  }

  public void setDexMergerExecutable(File dexMergerExecutable) {
    this.dexMergerExecutable = Optional.fromNullable(dexMergerExecutable);
  }

  @TaskAction
  void exec() {
    WorkQueue workQueue =
        workerExecutor.processIsolation(
            workerSpec -> {
              JavaForkOptions forkOptions = workerSpec.getForkOptions();
              if (!dexMergerExecutable.isPresent()) {
                setDexMergerExecutable(
                    forkOptions
                        .getWorkingDir()
                        .toPath()
                        .resolve(Utils.dexMergerExecutable())
                        .toFile());
              }
            });
    workQueue.submit(
        RunDexMerger.class,
        parameters -> {
          parameters.getSources().set(source.getFiles());
          parameters.getDestination().set(destination);
          parameters.getDexMergerExecutable().set(dexMergerExecutable.get());
        });
  }

  public interface RunDexMergerParameters extends WorkParameters {

    SetProperty<File> getSources();

    RegularFileProperty getDestination();

    RegularFileProperty getDexMergerExecutable();
  }

  public abstract static class RunDexMerger implements WorkAction<RunDexMergerParameters> {

    @Override
    public void execute() {
      try {
        RunDexMergerParameters parameters = getParameters();
        List<String> command = new ArrayList<>();
        command.add(parameters.getDexMergerExecutable().getAsFile().get().getCanonicalPath());
        command.add(parameters.getDestination().getAsFile().get().getCanonicalPath());
        for (File source : parameters.getSources().get()) {
          command.add(source.getCanonicalPath());
        }
        Process dexMerger = new ProcessBuilder(command).inheritIO().start();
        int exitCode = dexMerger.waitFor();
        if (exitCode != 0) {
          throw new RuntimeException("Dex merger failed with code " + exitCode);
        }
      } catch (IOException e) {
        throw new java.io.UncheckedIOException(e);
      } catch (InterruptedException e) {
        throw new RuntimeException(e);
      }
    }
  }
}