import org.gradle.caching.BuildCacheEntryReader;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;

public class LoadTarget implements BuildCacheEntryReader {

    private final File file;
    private boolean loaded;

    public LoadTarget(File file) {
        this.file = file;
    }

    @Override
    public void readFrom(InputStream input) throws IOException {

        LOGGER.debug(description);
        LoadTarget loadTarget = new LoadTarget(loadTargetFile);
        try {
            loadInner(description, key, loadTarget);
        } catch (Exception e) {
            failure(Operation.LOAD, key, e);
        }
        return maybeUnpack(loadTarget, unpackFunction);
    }

    protected void loadInner(String description, BuildCacheKey key, LoadTarget loadTarget) {

        buildOperationRunner.run(new RunnableBuildOperation() {
            @Override
            public void run(BuildOperationContext context) {
                loadInner(key, new OpFiringEntryReader(loadTarget));
                context.setResult(
                    loadTarget.isLoaded()

import org.junit.Rule

class LoadTargetTest extends Specification {

    @Rule
    final TestNameTestDirectoryProvider temporaryFolder = new TestNameTestDirectoryProvider(getClass())

    def target = new LoadTarget(temporaryFolder.file("file"))

    static class TestInputStream extends InputStream {

        boolean closed
        boolean error

        @Override
        int read() throws IOException {