Refactor removable drive tasks.

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/file/RemovableDriveManager.java

@@ -10,32 +10,31 @@ import javax.annotation.Nullable;
 public interface RemovableDriveManager {
 
 	/**
-	 * Returns the currently running reader task for the given contact,
-	 * or null if no task is running.
+	 * Returns the currently running reader task, or null if no reader task
+	 * is running.
 	 */
 	@Nullable
-	RemovableDriveTask getCurrentReaderTask(ContactId c);
+	RemovableDriveTask getCurrentReaderTask();
 
 	/**
-	 * Returns the currently running writer task for the given contact,
-	 * or null if no task is running.
+	 * Returns the currently running writer task,  or null if no writer task
+	 * is running.
 	 */
 	@Nullable
-	RemovableDriveTask getCurrentWriterTask(ContactId c);
+	RemovableDriveTask getCurrentWriterTask();
 
 	/**
-	 * Starts and returns a reader task for the given contact, reading from
-	 * a stream described by the given transport properties. If a reader task
-	 * for the contact is already running, it will be returned and the
-	 * transport properties will be ignored.
+	 * Starts and returns a reader task, reading from a stream described by
+	 * the given transport properties. If a reader task is already running,
+	 * it will be returned and the argument will be ignored.
 	 */
-	RemovableDriveTask startReaderTask(ContactId c, TransportProperties p);
+	RemovableDriveTask startReaderTask(TransportProperties p);
 
 	/**
 	 * Starts and returns a writer task for the given contact, writing to
 	 * a stream described by the given transport properties. If a writer task
-	 * for the contact is already running, it will be returned and the
-	 * transport properties will be ignored.
+	 * is already running, it will be returned and the arguments will be
+	 * ignored.
 	 */
 	RemovableDriveTask startWriterTask(ContactId c, TransportProperties p);
 }

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/file/RemovableDriveTask.java

@@ -39,7 +39,7 @@ public interface RemovableDriveTask extends Runnable {
 
 		/**
 		 * Returns the total length in bytes of the messages read or written
-		 * so far.
+		 * so far, or zero if the total is unknown.
 		 */
 		public long getDone() {
 			return done;

bramble-core/src/main/java/org/briarproject/bramble/plugin/file/RemovableDriveManagerImpl.java

@@ -7,10 +7,10 @@ import org.briarproject.bramble.api.plugin.file.RemovableDriveManager;
 import org.briarproject.bramble.api.plugin.file.RemovableDriveTask;
 import org.briarproject.bramble.api.properties.TransportProperties;
 
-import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.Executor;
 
 import javax.annotation.Nullable;
+import javax.annotation.concurrent.GuardedBy;
 import javax.annotation.concurrent.ThreadSafe;
 import javax.inject.Inject;
 
@@ -21,10 +21,12 @@ class RemovableDriveManagerImpl
 
 	private final Executor ioExecutor;
 	private final RemovableDriveTaskFactory taskFactory;
-	private final ConcurrentHashMap<ContactId, RemovableDriveTask>
-			readers = new ConcurrentHashMap<>();
-	private final ConcurrentHashMap<ContactId, RemovableDriveTask>
-			writers = new ConcurrentHashMap<>();
+	private final Object lock = new Object();
+
+	@GuardedBy("lock")
+	private RemovableDriveTask reader = null;
+	@GuardedBy("lock")
+	private RemovableDriveTask writer = null;
 
 	@Inject
 	RemovableDriveManagerImpl(@IoExecutor Executor ioExecutor,
@@ -35,49 +37,54 @@ class RemovableDriveManagerImpl
 
 	@Nullable
 	@Override
-	public RemovableDriveTask getCurrentReaderTask(ContactId c) {
-		return readers.get(c);
+	public RemovableDriveTask getCurrentReaderTask() {
+		synchronized (lock) {
+			return reader;
+		}
 	}
 
 	@Nullable
 	@Override
-	public RemovableDriveTask getCurrentWriterTask(ContactId c) {
-		return writers.get(c);
+	public RemovableDriveTask getCurrentWriterTask() {
+		synchronized (lock) {
+			return writer;
+		}
 	}
 
 	@Override
-	public RemovableDriveTask startReaderTask(ContactId c,
-			TransportProperties p) {
-		RemovableDriveTask task = taskFactory.createReader(this, c, p);
-		RemovableDriveTask old = readers.putIfAbsent(c, task);
-		if (old == null) {
-			ioExecutor.execute(task);
-			return task;
-		} else {
-			return old;
+	public RemovableDriveTask startReaderTask(TransportProperties p) {
+		RemovableDriveTask created;
+		synchronized (lock) {
+			if (reader != null) return reader;
+			reader = created = taskFactory.createReader(this, p);
 		}
+		ioExecutor.execute(created);
+		return created;
 	}
 
 	@Override
 	public RemovableDriveTask startWriterTask(ContactId c,
 			TransportProperties p) {
-		RemovableDriveTask task = taskFactory.createWriter(this, c, p);
-		RemovableDriveTask old = writers.putIfAbsent(c, task);
-		if (old == null) {
-			ioExecutor.execute(task);
-			return task;
-		} else {
-			return old;
+		RemovableDriveTask created;
+		synchronized (lock) {
+			if (writer != null) return writer;
+			writer = created = taskFactory.createWriter(this, c, p);
+		}
+		ioExecutor.execute(created);
+		return created;
+	}
+
+	@Override
+	public void removeReader(RemovableDriveTask task) {
+		synchronized (lock) {
+			if (reader == task) reader = null;
 		}
 	}
 
 	@Override
-	public void removeReader(ContactId c, RemovableDriveTask task) {
-		readers.remove(c, task);
-	}
-
-	@Override
-	public void removeWriter(ContactId c, RemovableDriveTask task) {
-		writers.remove(c, task);
+	public void removeWriter(RemovableDriveTask task) {
+		synchronized (lock) {
+			if (writer == task) writer = null;
+		}
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/plugin/file/RemovableDriveReaderTask.java

@@ -1,15 +1,11 @@
 package org.briarproject.bramble.plugin.file;
 
 import org.briarproject.bramble.api.connection.ConnectionManager;
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventBus;
-import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.PluginManager;
 import org.briarproject.bramble.api.plugin.TransportConnectionReader;
 import org.briarproject.bramble.api.properties.TransportProperties;
-import org.briarproject.bramble.api.sync.event.MessageAddedEvent;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -20,8 +16,7 @@ import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.plugin.file.RemovableDriveConstants.ID;
 
 @NotNullByDefault
-class RemovableDriveReaderTask extends RemovableDriveTaskImpl
-		implements EventListener {
+class RemovableDriveReaderTask extends RemovableDriveTaskImpl {
 
 	private final static Logger LOG =
 			getLogger(RemovableDriveReaderTask.class.getName());
@@ -32,10 +27,9 @@ class RemovableDriveReaderTask extends RemovableDriveTaskImpl
 			ConnectionManager connectionManager,
 			EventBus eventBus,
 			RemovableDriveTaskRegistry registry,
-			ContactId contactId,
 			TransportProperties transportProperties) {
 		super(eventExecutor, pluginManager, connectionManager, eventBus,
-				registry, contactId, transportProperties);
+				registry, transportProperties);
 	}
 
 	@Override
@@ -44,25 +38,13 @@ class RemovableDriveReaderTask extends RemovableDriveTaskImpl
 				getPlugin().createReader(transportProperties);
 		if (r == null) {
 			LOG.warning("Failed to create reader");
-			registry.removeReader(contactId, this);
+			registry.removeReader(this);
 			setSuccess(false);
 			return;
 		}
-		eventBus.addListener(this);
 		connectionManager.manageIncomingConnection(ID, new DecoratedReader(r));
 	}
 
-	@Override
-	public void eventOccurred(Event e) {
-		if (e instanceof MessageAddedEvent) {
-			MessageAddedEvent m = (MessageAddedEvent) e;
-			if (contactId.equals(m.getContactId())) {
-				LOG.info("Message received");
-				addDone(m.getMessage().getRawLength());
-			}
-		}
-	}
-
 	private class DecoratedReader implements TransportConnectionReader {
 
 		private final TransportConnectionReader delegate;
@@ -80,8 +62,7 @@ class RemovableDriveReaderTask extends RemovableDriveTaskImpl
 		public void dispose(boolean exception, boolean recognised)
 				throws IOException {
 			delegate.dispose(exception, recognised);
-			registry.removeReader(contactId, RemovableDriveReaderTask.this);
-			eventBus.removeListener(RemovableDriveReaderTask.this);
+			registry.removeReader(RemovableDriveReaderTask.this);
 			setSuccess(!exception && recognised);
 		}
 	}

bramble-core/src/main/java/org/briarproject/bramble/plugin/file/RemovableDriveTaskFactory.java

@@ -9,7 +9,7 @@ import org.briarproject.bramble.api.properties.TransportProperties;
 interface RemovableDriveTaskFactory {
 
 	RemovableDriveTask createReader(RemovableDriveTaskRegistry registry,
-			ContactId c, TransportProperties p);
+			TransportProperties p);
 
 	RemovableDriveTask createWriter(RemovableDriveTaskRegistry registry,
 			ContactId c, TransportProperties p);

bramble-core/src/main/java/org/briarproject/bramble/plugin/file/RemovableDriveTaskFactoryImpl.java

@@ -41,9 +41,9 @@ class RemovableDriveTaskFactoryImpl implements RemovableDriveTaskFactory {
 
 	@Override
 	public RemovableDriveTask createReader(RemovableDriveTaskRegistry registry,
-			ContactId c, TransportProperties p) {
+			TransportProperties p) {
 		return new RemovableDriveReaderTask(eventExecutor, pluginManager,
-				connectionManager, eventBus, registry, c, p);
+				connectionManager, eventBus, registry, p);
 	}
 
 	@Override

bramble-core/src/main/java/org/briarproject/bramble/plugin/file/RemovableDriveTaskImpl.java

@@ -2,7 +2,6 @@ package org.briarproject.bramble.plugin.file;
 
 import org.briarproject.bramble.api.Consumer;
 import org.briarproject.bramble.api.connection.ConnectionManager;
-import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.PluginManager;
@@ -30,7 +29,6 @@ abstract class RemovableDriveTaskImpl implements RemovableDriveTask {
 	final ConnectionManager connectionManager;
 	final EventBus eventBus;
 	final RemovableDriveTaskRegistry registry;
-	final ContactId contactId;
 	final TransportProperties transportProperties;
 
 	private final Object lock = new Object();
@@ -45,14 +43,12 @@ abstract class RemovableDriveTaskImpl implements RemovableDriveTask {
 			ConnectionManager connectionManager,
 			EventBus eventBus,
 			RemovableDriveTaskRegistry registry,
-			ContactId contactId,
 			TransportProperties transportProperties) {
 		this.eventExecutor = eventExecutor;
 		this.pluginManager = pluginManager;
 		this.connectionManager = connectionManager;
 		this.eventBus = eventBus;
 		this.registry = registry;
-		this.contactId = contactId;
 		this.transportProperties = transportProperties;
 	}
 

bramble-core/src/main/java/org/briarproject/bramble/plugin/file/RemovableDriveTaskRegistry.java

@@ -1,13 +1,12 @@
 package org.briarproject.bramble.plugin.file;
 
-import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.file.RemovableDriveTask;
 
 @NotNullByDefault
 interface RemovableDriveTaskRegistry {
 
-	void removeReader(ContactId c, RemovableDriveTask task);
+	void removeReader(RemovableDriveTask task);
 
-	void removeWriter(ContactId c, RemovableDriveTask task);
+	void removeWriter(RemovableDriveTask task);
 }

bramble-core/src/main/java/org/briarproject/bramble/plugin/file/RemovableDriveWriterTask.java

@@ -33,6 +33,7 @@ class RemovableDriveWriterTask extends RemovableDriveTaskImpl
 			getLogger(RemovableDriveWriterTask.class.getName());
 
 	private final DatabaseComponent db;
+	private final ContactId contactId;
 
 	RemovableDriveWriterTask(
 			DatabaseComponent db,
@@ -44,8 +45,9 @@ class RemovableDriveWriterTask extends RemovableDriveTaskImpl
 			ContactId contactId,
 			TransportProperties transportProperties) {
 		super(eventExecutor, pluginManager, connectionManager, eventBus,
-				registry, contactId, transportProperties);
+				registry, transportProperties);
 		this.db = db;
+		this.contactId = contactId;
 	}
 
 	@Override
@@ -54,7 +56,7 @@ class RemovableDriveWriterTask extends RemovableDriveTaskImpl
 		TransportConnectionWriter w = plugin.createWriter(transportProperties);
 		if (w == null) {
 			LOG.warning("Failed to create writer");
-			registry.removeWriter(contactId, this);
+			registry.removeWriter(this);
 			setSuccess(false);
 			return;
 		}
@@ -64,7 +66,7 @@ class RemovableDriveWriterTask extends RemovableDriveTaskImpl
 					db.getMessageBytesToSend(txn, contactId, maxLatency)));
 		} catch (DbException e) {
 			logException(LOG, WARNING, e);
-			registry.removeWriter(contactId, this);
+			registry.removeWriter(this);
 			setSuccess(false);
 			return;
 		}
@@ -112,7 +114,7 @@ class RemovableDriveWriterTask extends RemovableDriveTaskImpl
 		@Override
 		public void dispose(boolean exception) throws IOException {
 			delegate.dispose(exception);
-			registry.removeWriter(contactId, RemovableDriveWriterTask.this);
+			registry.removeWriter(RemovableDriveWriterTask.this);
 			eventBus.removeListener(RemovableDriveWriterTask.this);
 			setSuccess(!exception);
 		}

bramble-core/src/test/java/org/briarproject/bramble/plugin/file/RemovableDriveIntegrationTest.java

@@ -70,9 +70,9 @@ public class RemovableDriveIntegrationTest extends BrambleTestCase {
 		ContactId aliceId = setUp(bob, bobIdentity,
 				aliceIdentity.getLocalAuthor(), false);
 		// Sync Alice's client versions and transport properties
-		read(bob, aliceId, write(alice, bobId), 2);
+		read(bob, write(alice, bobId), 2);
 		// Sync Bob's client versions and transport properties
-		read(alice, bobId, write(bob, aliceId), 2);
+		read(alice, write(bob, aliceId), 2);
 	}
 
 	private ContactId setUp(RemovableDriveIntegrationTestComponent device,
@@ -92,7 +92,7 @@ public class RemovableDriveIntegrationTest extends BrambleTestCase {
 
 	@SuppressWarnings("SameParameterValue")
 	private void read(RemovableDriveIntegrationTestComponent device,
-			ContactId contactId, File file, int deliveries) throws Exception {
+			File file, int deliveries) throws Exception {
 		// Listen for message deliveries
 		MessageDeliveryListener listener =
 				new MessageDeliveryListener(deliveries);
@@ -100,8 +100,8 @@ public class RemovableDriveIntegrationTest extends BrambleTestCase {
 		// Read the incoming stream
 		TransportProperties p = new TransportProperties();
 		p.put(PROP_PATH, file.getAbsolutePath());
-		RemovableDriveTask reader = device.getRemovableDriveManager()
-				.startReaderTask(contactId, p);
+		RemovableDriveTask reader =
+				device.getRemovableDriveManager().startReaderTask(p);
 		CountDownLatch disposedLatch = new CountDownLatch(1);
 		reader.addObserver(state -> {
 			if (state.isFinished()) disposedLatch.countDown();

briar-android/src/main/java/org/briarproject/briar/android/removabledrive/RemovableDriveViewModel.java

@@ -59,15 +59,15 @@ class RemovableDriveViewModel extends AndroidViewModel {
 		return observe(manager.startWriterTask(contactId, p));
 	}
 
-	LiveData<State> read(ContactId contactId, Uri uri) {
+	LiveData<State> read(Uri uri) {
 		TransportProperties p = new TransportProperties();
 		p.put(PROP_URI, uri.toString());
-		return observe(manager.startReaderTask(contactId, p));
+		return observe(manager.startReaderTask(p));
 	}
 
 	@Nullable
-	LiveData<State> ongoingWrite(ContactId contactId) {
-		RemovableDriveTask task = manager.getCurrentWriterTask(contactId);
+	LiveData<State> ongoingWrite() {
+		RemovableDriveTask task = manager.getCurrentWriterTask();
 		if (task == null) {
 			return null;
 		}
@@ -75,8 +75,8 @@ class RemovableDriveViewModel extends AndroidViewModel {
 	}
 
 	@Nullable
-	LiveData<State> ongoingRead(ContactId contactId) {
-		RemovableDriveTask task = manager.getCurrentReaderTask(contactId);
+	LiveData<State> ongoingRead() {
+		RemovableDriveTask task = manager.getCurrentReaderTask();
 		if (task == null) {
 			return null;
 		}