- CryptoFS + InMemory Benchmark test

- faster growing in-memory files

main/filesystem-inmemory/src/main/java/org/cryptomator/filesystem/inmem/InMemoryFile.java

@@ -23,11 +23,18 @@ import org.cryptomator.filesystem.WritableFile;
 
 class InMemoryFile extends InMemoryNode implements File {
 
+	/** 1000kb */
+	static final int INITIAL_SIZE = 100 * 1024;
+
+	/** 140% */
+	static final double GROWTH_RATE = 1.4;
+
 	private final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-	private ByteBuffer content = ByteBuffer.allocate(0);
+	private volatile ByteBuffer content = ByteBuffer.allocate(INITIAL_SIZE);
 
 	public InMemoryFile(InMemoryFolder parent, String name, Instant lastModified, Instant creationTime) {
 		super(parent, name, lastModified, creationTime);
+		content.flip();
 	}
 
 	@Override

main/filesystem-inmemory/src/main/java/org/cryptomator/filesystem/inmem/InMemoryReadableFile.java

@@ -22,7 +22,7 @@ class InMemoryReadableFile implements ReadableFile {
 	private final Supplier<ByteBuffer> contentGetter;
 	private final ReadLock readLock;
 	private boolean open = true;
-	private int position = 0;
+	private volatile int position = 0;
 
 	public InMemoryReadableFile(Supplier<ByteBuffer> contentGetter, ReadLock readLock) {
 		this.contentGetter = contentGetter;

main/filesystem-inmemory/src/main/java/org/cryptomator/filesystem/inmem/InMemoryWritableFile.java

@@ -28,7 +28,7 @@ public class InMemoryWritableFile implements WritableFile {
 	private final WriteLock writeLock;
 
 	private boolean open = true;
-	private int position = 0;
+	private volatile int position = 0;
 
 	public InMemoryWritableFile(Consumer<Instant> lastModifiedSetter, Consumer<Instant> creationTimeSetter, Supplier<ByteBuffer> contentGetter, Consumer<ByteBuffer> contentSetter, Consumer<Void> deleter,
 			WriteLock writeLock) {
@@ -74,15 +74,19 @@ public class InMemoryWritableFile implements WritableFile {
 	@Override
 	public int write(ByteBuffer source) throws UncheckedIOException {
 		ByteBuffer destination = contentGetter.get();
+		int oldFileSize = destination.limit();
 		int requiredSize = position + source.remaining();
+		int newFileSize = Math.max(oldFileSize, requiredSize);
 		if (destination.capacity() < requiredSize) {
 			ByteBuffer old = destination;
-			old.rewind();
-			destination = ByteBuffer.allocate(requiredSize);
+			old.clear();
+			int newBufferSize = Math.max(requiredSize, (int) (destination.capacity() * InMemoryFile.GROWTH_RATE));
+			destination = ByteBuffer.allocate(newBufferSize);
 			ByteBuffers.copy(old, destination);
 			contentSetter.accept(destination);
 		}
 		destination.position(position);
+		destination.limit(newFileSize);
 		int numWritten = ByteBuffers.copy(source, destination);
 		this.position += numWritten;
 		return numWritten;