*
 * Maintains references to the location of files in the persistent local. Does not deal with moving files into the local.
 *
 * @param <K> The type of the key to the index
 */
public interface CachedExternalResourceIndex<K> {

    /**
     * Adds a resolution to the index.
     *
     * The incoming file is expected to be in the persistent local. This method will not move/copy the file there.
     * <p>
     *

    private final Path readOnlyCachePath;
    private final CachedExternalResourceIndex<String> readOnlyCache;
    private final CachedExternalResourceIndex<String> writableCache;

    public TwoStageByUrlCachedExternalResourceIndex(Path readOnlyCachePath, CachedExternalResourceIndex<String> readOnlyCache, CachedExternalResourceIndex<String> writableCache) {

    Path readOnlyPath = Stub(Path)
    File artifact = Stub(File)
    ExternalResourceMetaData metadata = Stub(ExternalResourceMetaData)

    CachedExternalResourceIndex<String> readIndex = Mock(CachedExternalResourceIndex)
    CachedExternalResourceIndex<String> writeIndex = Mock(CachedExternalResourceIndex)

    @Subject

    private static final Logger LOGGER = LoggerFactory.getLogger(DefaultCacheAwareExternalResourceAccessor.class);

    private final ExternalResourceRepository delegate;
    private final CachedExternalResourceIndex<String> cachedExternalResourceIndex;
    private final BuildCommencedTimeProvider timeProvider;
    private final TemporaryFileProvider temporaryFileProvider;
    private final ArtifactCacheLockingAccessCoordinator cacheAccessCoordinator;

    private val cachedExternalResourceIndex: CachedExternalResourceIndex<String>
) {

    fun isUpToDate(uri: URI): Boolean =
        if (startParameter.isOffline) {
            true
        } else {
            val externalResourceName = ExternalResourceName(uri)

            val cached = cachedExternalResourceIndex.lookup(externalResourceName.toString())

    private final List<ResourceConnectorFactory> registeredProtocols = new ArrayList<>();

    private final TemporaryFileProvider temporaryFileProvider;
    private final CachedExternalResourceIndex<String> cachedExternalResourceIndex;
    private final BuildCommencedTimeProvider timeProvider;
    private final ArtifactCacheLockingAccessCoordinator artifactCacheLockingManager;
    private final BuildOperationRunner buildOperationRunner;

import org.gradle.internal.resource.cached.CachedExternalResourceIndex;
import org.gradle.internal.resource.cached.ExternalResourceFileStore;
import org.gradle.internal.service.scopes.Scope;
import org.gradle.internal.service.scopes.ServiceScope;

@ServiceScope(Scope.BuildTree.class)
public class FileStoreAndIndexProvider {
    private final CachedExternalResourceIndex<String> externalResourceIndex;

    public ResourceConnectorRepositoryTransport(String name,
                                                TemporaryFileProvider temporaryFileProvider,
                                                CachedExternalResourceIndex<String> cachedExternalResourceIndex,
                                                BuildCommencedTimeProvider timeProvider,
                                                ArtifactCacheLockingAccessCoordinator cacheAccessCoordinator,

    private final FileResourceRepository repository;
    private final FileCacheAwareExternalResourceAccessor resourceAccessor;

import org.gradle.internal.hash.ChecksumService;
import org.gradle.internal.resource.cached.ByUrlCachedExternalResourceIndex;
import org.gradle.internal.resource.cached.CachedExternalResourceIndex;
import org.gradle.internal.resource.cached.DefaultExternalResourceFileStore;
import org.gradle.internal.resource.cached.ExternalResourceFileStore;