Add MailboxFileManager for downloads (uploads to be added later).

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxDirectory.java

@@ -0,0 +1,22 @@
+package org.briarproject.bramble.api.mailbox;
+
+import java.io.File;
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import javax.inject.Qualifier;
+
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.PARAMETER;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+/**
+ * Annotation for injecting the {@link File directory} where the Mailbox plugin
+ * should store its state.
+ */
+@Qualifier
+@Target({FIELD, METHOD, PARAMETER})
+@Retention(RUNTIME)
+public @interface MailboxDirectory {
+}

bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxFileManager.java

@@ -0,0 +1,24 @@
+package org.briarproject.bramble.mailbox;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.io.File;
+import java.io.IOException;
+
+import javax.annotation.concurrent.ThreadSafe;
+
+@ThreadSafe
+@NotNullByDefault
+interface MailboxFileManager {
+
+	/**
+	 * Creates an empty file for storing a download.
+	 */
+	File createTempFileForDownload() throws IOException;
+
+	/**
+	 * Handles a file that has been downloaded. The file should be created
+	 * with {@link #createTempFileForDownload()}.
+	 */
+	void handleDownloadedFile(File f);
+}

bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxFileManagerImpl.java

@@ -0,0 +1,174 @@
+package org.briarproject.bramble.mailbox;
+
+import org.briarproject.bramble.api.connection.ConnectionManager;
+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.lifecycle.IoExecutor;
+import org.briarproject.bramble.api.lifecycle.LifecycleManager;
+import org.briarproject.bramble.api.mailbox.MailboxDirectory;
+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.plugin.event.TransportActiveEvent;
+import org.briarproject.bramble.api.plugin.simplex.SimplexPlugin;
+import org.briarproject.bramble.api.properties.TransportProperties;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.Executor;
+import java.util.logging.Logger;
+
+import javax.annotation.concurrent.ThreadSafe;
+import javax.inject.Inject;
+
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.RUNNING;
+import static org.briarproject.bramble.api.mailbox.MailboxConstants.ID;
+import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
+import static org.briarproject.bramble.api.plugin.file.FileConstants.PROP_PATH;
+import static org.briarproject.bramble.util.LogUtils.logException;
+
+@ThreadSafe
+@NotNullByDefault
+class MailboxFileManagerImpl implements MailboxFileManager, EventListener {
+
+	private static final Logger LOG =
+			getLogger(MailboxFileManagerImpl.class.getName());
+
+	// Package access for testing
+	static final String DOWNLOAD_DIR_NAME = "downloads";
+
+	private final Executor ioExecutor;
+	private final PluginManager pluginManager;
+	private final ConnectionManager connectionManager;
+	private final LifecycleManager lifecycleManager;
+	private final File mailboxDir;
+	private final EventBus eventBus;
+	private final CountDownLatch orphanLatch = new CountDownLatch(1);
+
+	@Inject
+	MailboxFileManagerImpl(@IoExecutor Executor ioExecutor,
+			PluginManager pluginManager,
+			ConnectionManager connectionManager,
+			LifecycleManager lifecycleManager,
+			@MailboxDirectory File mailboxDir,
+			EventBus eventBus) {
+		this.ioExecutor = ioExecutor;
+		this.pluginManager = pluginManager;
+		this.connectionManager = connectionManager;
+		this.lifecycleManager = lifecycleManager;
+		this.mailboxDir = mailboxDir;
+		this.eventBus = eventBus;
+	}
+
+	@Override
+	public File createTempFileForDownload() throws IOException {
+		// Wait for orphaned files to be handled before creating new files
+		try {
+			orphanLatch.await();
+		} catch (InterruptedException e) {
+			throw new IOException(e);
+		}
+		File downloadDir = createDirectoryIfNeeded(DOWNLOAD_DIR_NAME);
+		return File.createTempFile("mailbox", ".tmp", downloadDir);
+	}
+
+	private File createDirectoryIfNeeded(String name) throws IOException {
+		File dir = new File(mailboxDir, name);
+		//noinspection ResultOfMethodCallIgnored
+		dir.mkdirs();
+		if (!dir.isDirectory()) {
+			throw new IOException("Failed to create directory '" + name + "'");
+		}
+		return dir;
+	}
+
+	@Override
+	public void handleDownloadedFile(File f) {
+		// We shouldn't reach this point until the plugin has been started
+		SimplexPlugin plugin =
+				(SimplexPlugin) requireNonNull(pluginManager.getPlugin(ID));
+		TransportProperties p = new TransportProperties();
+		p.put(PROP_PATH, f.getAbsolutePath());
+		TransportConnectionReader reader = plugin.createReader(p);
+		if (reader == null) {
+			LOG.warning("Failed to create reader for downloaded file");
+			return;
+		}
+		TransportConnectionReader decorated = new MailboxFileReader(reader, f);
+		LOG.info("Reading downloaded file");
+		connectionManager.manageIncomingConnection(ID, decorated,
+				exception -> isHandlingComplete(exception, true));
+	}
+
+	private boolean isHandlingComplete(boolean exception, boolean recognised) {
+		// If we've successfully read the file then we're done
+		if (!exception && recognised) return true;
+		// If the app is shutting down we may get spurious IO exceptions
+		// due to executors being shut down. Leave the file in the download
+		// directory and we'll try to read it again at the next startup
+		return !lifecycleManager.getLifecycleState().isAfter(RUNNING);
+	}
+
+	@Override
+	public void eventOccurred(Event e) {
+		if (e instanceof TransportActiveEvent) {
+			TransportActiveEvent t = (TransportActiveEvent) e;
+			if (t.getTransportId().equals(ID)) {
+				ioExecutor.execute(this::handleOrphanedFiles);
+				eventBus.removeListener(this);
+			}
+		}
+	}
+
+	/**
+	 * This method is called at startup, as soon as the plugin is started, to
+	 * handle any files that were left in the download directory at the last
+	 * shutdown.
+	 */
+	@IoExecutor
+	private void handleOrphanedFiles() {
+		try {
+			File downloadDir = createDirectoryIfNeeded(DOWNLOAD_DIR_NAME);
+			File[] orphans = downloadDir.listFiles();
+			// Now that we've got the list of orphans, new files can be created
+			orphanLatch.countDown();
+			if (orphans != null) for (File f : orphans) handleDownloadedFile(f);
+		} catch (IOException e) {
+			logException(LOG, WARNING, e);
+		}
+	}
+
+	private class MailboxFileReader implements TransportConnectionReader {
+
+		private final TransportConnectionReader delegate;
+		private final File file;
+
+		private MailboxFileReader(TransportConnectionReader delegate,
+				File file) {
+			this.delegate = delegate;
+			this.file = file;
+		}
+
+		@Override
+		public InputStream getInputStream() throws IOException {
+			return delegate.getInputStream();
+		}
+
+		@Override
+		public void dispose(boolean exception, boolean recognised)
+				throws IOException {
+			delegate.dispose(exception, recognised);
+			if (isHandlingComplete(exception, recognised)) {
+				LOG.info("Deleting downloaded file");
+				if (!file.delete()) {
+					LOG.warning("Failed to delete downloaded file");
+				}
+			}
+		}
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxModule.java

@@ -4,6 +4,7 @@ import org.briarproject.bramble.api.FeatureFlags;
 import org.briarproject.bramble.api.client.ClientHelper;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.data.MetadataEncoder;
+import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.mailbox.MailboxManager;
 import org.briarproject.bramble.api.mailbox.MailboxSettingsManager;
@@ -34,6 +35,8 @@ public class MailboxModule {
 		MailboxUpdateValidator mailboxUpdateValidator;
 		@Inject
 		MailboxUpdateManager mailboxUpdateManager;
+		@Inject
+		MailboxFileManager mailboxFileManager;
 	}
 
 	@Provides
@@ -101,4 +104,14 @@ public class MailboxModule {
 		}
 		return mailboxUpdateManager;
 	}
+
+	@Provides
+	@Singleton
+	MailboxFileManager provideMailboxFileManager(FeatureFlags featureFlags,
+			EventBus eventBus, MailboxFileManagerImpl mailboxFileManager) {
+		if (featureFlags.shouldEnableMailbox()) {
+			eventBus.addListener(mailboxFileManager);
+		}
+		return mailboxFileManager;
+	}
 }

bramble-core/src/test/java/org/briarproject/bramble/mailbox/MailboxFileManagerImplTest.java

@@ -0,0 +1,194 @@
+package org.briarproject.bramble.mailbox;
+
+import org.briarproject.bramble.api.connection.ConnectionManager;
+import org.briarproject.bramble.api.connection.ConnectionManager.TagController;
+import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.lifecycle.LifecycleManager;
+import org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState;
+import org.briarproject.bramble.api.plugin.PluginManager;
+import org.briarproject.bramble.api.plugin.TransportConnectionReader;
+import org.briarproject.bramble.api.plugin.event.TransportActiveEvent;
+import org.briarproject.bramble.api.plugin.simplex.SimplexPlugin;
+import org.briarproject.bramble.api.properties.TransportProperties;
+import org.briarproject.bramble.test.BrambleMockTestCase;
+import org.briarproject.bramble.test.CaptureArgumentAction;
+import org.briarproject.bramble.test.RunAction;
+import org.jmock.Expectations;
+import org.jmock.lib.action.DoAllAction;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.io.File;
+import java.util.concurrent.Executor;
+import java.util.concurrent.atomic.AtomicReference;
+
+import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.RUNNING;
+import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STOPPING;
+import static org.briarproject.bramble.api.mailbox.MailboxConstants.ID;
+import static org.briarproject.bramble.api.plugin.file.FileConstants.PROP_PATH;
+import static org.briarproject.bramble.mailbox.MailboxFileManagerImpl.DOWNLOAD_DIR_NAME;
+import static org.briarproject.bramble.test.TestUtils.deleteTestDirectory;
+import static org.briarproject.bramble.test.TestUtils.getTestDirectory;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+public class MailboxFileManagerImplTest extends BrambleMockTestCase {
+
+	private final Executor ioExecutor = context.mock(Executor.class);
+	private final PluginManager pluginManager =
+			context.mock(PluginManager.class);
+	private final ConnectionManager connectionManager =
+			context.mock(ConnectionManager.class);
+	private final LifecycleManager lifecycleManager =
+			context.mock(LifecycleManager.class);
+	private final EventBus eventBus = context.mock(EventBus.class);
+	private final SimplexPlugin plugin = context.mock(SimplexPlugin.class);
+	private final TransportConnectionReader transportConnectionReader =
+			context.mock(TransportConnectionReader.class);
+
+	private File mailboxDir;
+	private MailboxFileManagerImpl manager;
+
+	@Before
+	public void setUp() {
+		mailboxDir = getTestDirectory();
+		manager = new MailboxFileManagerImpl(ioExecutor, pluginManager,
+				connectionManager, lifecycleManager, mailboxDir, eventBus);
+	}
+
+	@After
+	public void tearDown() {
+		deleteTestDirectory(mailboxDir);
+	}
+
+	@Test
+	public void testHandlesOrphanedFilesAtStartup() throws Exception {
+		// Create an orphaned file, left behind at the previous shutdown
+		File downloadDir = new File(mailboxDir, DOWNLOAD_DIR_NAME);
+		//noinspection ResultOfMethodCallIgnored
+		downloadDir.mkdirs();
+		File orphan = new File(downloadDir, "orphan");
+		assertTrue(orphan.createNewFile());
+
+		TransportProperties props = new TransportProperties();
+		props.put(PROP_PATH, orphan.getAbsolutePath());
+
+		// When the plugin becomes active the orphaned file should be handled
+		context.checking(new Expectations() {{
+			oneOf(ioExecutor).execute(with(any(Runnable.class)));
+			will(new RunAction());
+			oneOf(eventBus).removeListener(manager);
+			oneOf(pluginManager).getPlugin(ID);
+			will(returnValue(plugin));
+			oneOf(plugin).createReader(props);
+			will(returnValue(transportConnectionReader));
+			oneOf(connectionManager).manageIncomingConnection(with(ID),
+					with(any(TransportConnectionReader.class)),
+					with(any(TagController.class)));
+		}});
+
+		manager.eventOccurred(new TransportActiveEvent(ID));
+	}
+
+	@Test
+	public void testDeletesFileWhenReadSucceeds() throws Exception {
+		expectCheckForOrphans();
+		manager.eventOccurred(new TransportActiveEvent(ID));
+
+		File f = manager.createTempFileForDownload();
+		AtomicReference<TransportConnectionReader> reader =
+				new AtomicReference<>(null);
+		AtomicReference<TagController> controller = new AtomicReference<>(null);
+
+		expectPassFileToConnectionManager(f, reader, controller);
+		manager.handleDownloadedFile(f);
+
+		// The read is successful, so the tag controller should allow the tag
+		// to be marked as read and the reader should delete the file
+		context.checking(new Expectations() {{
+			oneOf(transportConnectionReader).dispose(false, true);
+		}});
+
+		assertTrue(controller.get().shouldMarkTagAsRecognised(false));
+		reader.get().dispose(false, true);
+		assertFalse(f.exists());
+	}
+
+	@Test
+	public void testDeletesFileWhenTagIsNotRecognised() throws Exception {
+		testDeletesFile(false, RUNNING, false);
+	}
+
+	@Test
+	public void testDeletesFileWhenReadFails() throws Exception {
+		testDeletesFile(true, RUNNING, false);
+	}
+
+	@Test
+	public void testDoesNotDeleteFileWhenTagIsNotRecognisedAtShutdown()
+			throws Exception {
+		testDeletesFile(false, STOPPING, true);
+	}
+
+	@Test
+	public void testDoesNotDeleteFileWhenReadFailsAtShutdown()
+			throws Exception {
+		testDeletesFile(true, STOPPING, true);
+	}
+
+	private void testDeletesFile(boolean recognised, LifecycleState state,
+			boolean fileExists) throws Exception {
+		expectCheckForOrphans();
+		manager.eventOccurred(new TransportActiveEvent(ID));
+
+		File f = manager.createTempFileForDownload();
+		AtomicReference<TransportConnectionReader> reader =
+				new AtomicReference<>(null);
+		AtomicReference<TagController> controller = new AtomicReference<>(null);
+
+		expectPassFileToConnectionManager(f, reader, controller);
+		manager.handleDownloadedFile(f);
+
+		context.checking(new Expectations() {{
+			oneOf(transportConnectionReader).dispose(true, recognised);
+			oneOf(lifecycleManager).getLifecycleState();
+			will(returnValue(state));
+		}});
+
+		reader.get().dispose(true, recognised);
+		assertEquals(fileExists, f.exists());
+	}
+
+	private void expectCheckForOrphans() {
+		context.checking(new Expectations() {{
+			oneOf(ioExecutor).execute(with(any(Runnable.class)));
+			will(new RunAction());
+			oneOf(eventBus).removeListener(manager);
+		}});
+	}
+
+	private void expectPassFileToConnectionManager(File f,
+			AtomicReference<TransportConnectionReader> reader,
+			AtomicReference<TagController> controller) {
+		TransportProperties props = new TransportProperties();
+		props.put(PROP_PATH, f.getAbsolutePath());
+
+		context.checking(new Expectations() {{
+			oneOf(pluginManager).getPlugin(ID);
+			will(returnValue(plugin));
+			oneOf(plugin).createReader(props);
+			will(returnValue(transportConnectionReader));
+			oneOf(connectionManager).manageIncomingConnection(with(ID),
+					with(any(TransportConnectionReader.class)),
+					with(any(TagController.class)));
+			will(new DoAllAction(
+					new CaptureArgumentAction<>(reader,
+							TransportConnectionReader.class, 1),
+					new CaptureArgumentAction<>(controller,
+							TagController.class, 2)
+			));
+		}});
+	}
+}

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

@@ -13,6 +13,7 @@ import org.briarproject.bramble.system.DefaultWakefulIoExecutorModule;
 import org.briarproject.bramble.system.TimeTravelModule;
 import org.briarproject.bramble.test.TestDatabaseConfigModule;
 import org.briarproject.bramble.test.TestFeatureFlagModule;
+import org.briarproject.bramble.test.TestMailboxDirectoryModule;
 import org.briarproject.bramble.test.TestSecureRandomModule;
 
 import javax.inject.Singleton;
@@ -27,6 +28,7 @@ import dagger.Component;
 		DefaultWakefulIoExecutorModule.class,
 		TestDatabaseConfigModule.class,
 		TestFeatureFlagModule.class,
+		TestMailboxDirectoryModule.class,
 		RemovableDriveIntegrationTestModule.class,
 		RemovableDriveModule.class,
 		TestSecureRandomModule.class,

bramble-core/src/test/java/org/briarproject/bramble/test/BrambleCoreIntegrationTestModule.java

@@ -13,6 +13,7 @@ import dagger.Module;
 		DefaultWakefulIoExecutorModule.class,
 		TestDatabaseConfigModule.class,
 		TestFeatureFlagModule.class,
+		TestMailboxDirectoryModule.class,
 		TestPluginConfigModule.class,
 		TestSecureRandomModule.class,
 		TimeTravelModule.class

bramble-core/src/test/java/org/briarproject/bramble/test/TestMailboxDirectoryModule.java

@@ -0,0 +1,18 @@
+package org.briarproject.bramble.test;
+
+import org.briarproject.bramble.api.mailbox.MailboxDirectory;
+
+import java.io.File;
+
+import dagger.Module;
+import dagger.Provides;
+
+@Module
+public class TestMailboxDirectoryModule {
+
+	@Provides
+	@MailboxDirectory
+	File provideMailboxDirectory() {
+		return new File("mailbox");
+	}
+}

briar-android/src/main/java/org/briarproject/briar/android/AppModule.java

@@ -14,6 +14,7 @@ import org.briarproject.bramble.api.crypto.PublicKey;
 import org.briarproject.bramble.api.db.DatabaseConfig;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
+import org.briarproject.bramble.api.mailbox.MailboxDirectory;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.BluetoothConstants;
 import org.briarproject.bramble.api.plugin.LanTcpConstants;
@@ -157,6 +158,13 @@ public class AppModule {
 		return new AndroidDatabaseConfig(dbDir, keyDir, keyStrengthener);
 	}
 
+	@Provides
+	@Singleton
+	@MailboxDirectory
+	File provideMailboxDirectory(Application app) {
+		return app.getDir("mailbox", MODE_PRIVATE);
+	}
+
 	@Provides
 	@Singleton
 	@TorDirectory

briar-headless/src/main/java/org/briarproject/briar/headless/HeadlessModule.kt

@@ -6,6 +6,7 @@ import dagger.Provides
 import org.briarproject.bramble.account.AccountModule
 import org.briarproject.bramble.api.FeatureFlags
 import org.briarproject.bramble.api.db.DatabaseConfig
+import org.briarproject.bramble.api.mailbox.MailboxDirectory
 import org.briarproject.bramble.api.plugin.PluginConfig
 import org.briarproject.bramble.api.plugin.TorConstants.DEFAULT_CONTROL_PORT
 import org.briarproject.bramble.api.plugin.TorConstants.DEFAULT_SOCKS_PORT
@@ -71,6 +72,12 @@ internal class HeadlessModule(private val appDir: File) {
         return HeadlessDatabaseConfig(dbDir, keyDir)
     }
 
+    @Provides
+    @MailboxDirectory
+    internal fun provideMailboxDirectory(): File {
+        return File(appDir, "mailbox")
+    }
+
     @Provides
     @TorDirectory
     internal fun provideTorDirectory(): File {

briar-headless/src/test/java/org/briarproject/briar/headless/HeadlessTestModule.kt

@@ -5,6 +5,7 @@ import dagger.Module
 import dagger.Provides
 import org.briarproject.bramble.account.AccountModule
 import org.briarproject.bramble.api.db.DatabaseConfig
+import org.briarproject.bramble.api.mailbox.MailboxDirectory
 import org.briarproject.bramble.api.plugin.PluginConfig
 import org.briarproject.bramble.api.plugin.TorConstants.DEFAULT_CONTROL_PORT
 import org.briarproject.bramble.api.plugin.TorConstants.DEFAULT_SOCKS_PORT
@@ -68,6 +69,12 @@ internal class HeadlessTestModule(private val appDir: File) {
         return HeadlessDatabaseConfig(dbDir, keyDir)
     }
 
+    @Provides
+    @MailboxDirectory
+    internal fun provideMailboxDirectory(): File {
+        return File(appDir, "mailbox")
+    }
+
     @Provides
     @TorSocksPort
     internal fun provideTorSocksPort(): Int = DEFAULT_SOCKS_PORT