- Fixes #128 and #119 by using unique directory id as associated data during filename encryption/decryption

- Using WeakValuedCache in all filesystem layers to prevent "twin" instances of the same folder
- Merge branch 'layered-io' of https://github.com/cryptomator/cryptomator into layered-io

main/filesystem-api/src/main/java/org/cryptomator/filesystem/delegating/DelegatingFolder.java

@@ -13,6 +13,7 @@ import java.time.Instant;
 import java.util.Optional;
 import java.util.stream.Stream;
 
+import org.cryptomator.common.WeakValuedCache;
 import org.cryptomator.filesystem.File;
 import org.cryptomator.filesystem.Folder;
 import org.cryptomator.filesystem.Node;
@@ -21,6 +22,8 @@ public abstract class DelegatingFolder<R extends DelegatingReadableFile, W exten
 		implements Folder {
 
 	private final D parent;
+	private final WeakValuedCache<Folder, D> folders = WeakValuedCache.usingLoader(this::newFolder);
+	private final WeakValuedCache<File, F> files = WeakValuedCache.usingLoader(this::newFile);
 
 	public DelegatingFolder(D parent, Folder delegate) {
 		super(delegate);
@@ -39,27 +42,27 @@ public abstract class DelegatingFolder<R extends DelegatingReadableFile, W exten
 
 	@Override
 	public Stream<D> folders() {
-		return delegate.folders().map(this::folder);
+		return delegate.folders().map(folders::get);
 	}
 
 	@Override
 	public Stream<F> files() throws UncheckedIOException {
-		return delegate.files().map(this::file);
+		return delegate.files().map(files::get);
 	}
 
 	@Override
 	public F file(String name) throws UncheckedIOException {
-		return file(delegate.file(name));
+		return files.get(delegate.file(name));
 	}
 
-	protected abstract F file(File delegate);
+	protected abstract F newFile(File delegate);
 
 	@Override
 	public D folder(String name) throws UncheckedIOException {
-		return folder(delegate.folder(name));
+		return folders.get(delegate.folder(name));
 	}
 
-	protected abstract D folder(Folder delegate);
+	protected abstract D newFolder(Folder delegate);
 
 	@Override
 	public void create() throws UncheckedIOException {

main/filesystem-api/src/test/java/org/cryptomator/filesystem/delegating/DelegatingFolderTest.java

@@ -161,4 +161,17 @@ public class DelegatingFolderTest {
 		Mockito.verify(mockFolder).delete();
 	}
 
+	@Test
+	public void testSubresourcesAreSameInstance() {
+		Folder mockFolder = Mockito.mock(Folder.class);
+		Folder mockSubFolder = Mockito.mock(Folder.class);
+		File mockSubFile = Mockito.mock(File.class);
+		Mockito.when(mockFolder.folder("mockSubFolder")).thenReturn(mockSubFolder);
+		Mockito.when(mockFolder.file("mockSubFile")).thenReturn(mockSubFile);
+
+		DelegatingFolder<?, ?, ?, ?> delegatingFolder = new TestDelegatingFolder(null, mockFolder);
+		Assert.assertSame(delegatingFolder.folder("mockSubFolder"), delegatingFolder.folder("mockSubFolder"));
+		Assert.assertSame(delegatingFolder.file("mockSubFile"), delegatingFolder.file("mockSubFile"));
+	}
+
 }

main/filesystem-api/src/test/java/org/cryptomator/filesystem/delegating/TestDelegatingFolder.java

@@ -10,12 +10,12 @@ class TestDelegatingFolder extends DelegatingFolder<DelegatingReadableFile, Dele
 	}
 
 	@Override
-	protected TestDelegatingFile file(File delegate) {
+	protected TestDelegatingFile newFile(File delegate) {
 		return new TestDelegatingFile(this, delegate);
 	}
 
 	@Override
-	protected TestDelegatingFolder folder(Folder delegate) {
+	protected TestDelegatingFolder newFolder(Folder delegate) {
 		return new TestDelegatingFolder(this, delegate);
 	}