Try printing db table sizes on startup

.gitlab-ci.yml

@@ -118,3 +118,11 @@ mailbox integration test:
     - cd "$CI_PROJECT_DIR"
     - bramble-core/src/test/bash/wait-for-mailbox.sh
     - OPTIONAL_TESTS=org.briarproject.bramble.mailbox.MailboxIntegrationTest ./gradlew --info bramble-core:test --tests MailboxIntegrationTest
+
+pre_release_tests:
+  extends: .optional_tests
+  script:
+    - OPTIONAL_TESTS=org.briarproject.bramble.plugin.tor.BridgeTest ./gradlew --info bramble-java:test --tests BridgeTest
+  timeout: 3h
+  only:
+    - tags

bramble-android/build.gradle

@@ -15,8 +15,8 @@ android {
 	defaultConfig {
 		minSdkVersion 16
 		targetSdkVersion 30
-		versionCode 10409
-		versionName "1.4.9"
+		versionCode 10406
+		versionName "1.4.6"
 		consumerProguardFiles 'proguard-rules.txt'
 
 		testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"

bramble-android/src/main/java/org/briarproject/bramble/network/AndroidNetworkManager.java

@@ -11,10 +11,7 @@ import android.net.LinkAddress;
 import android.net.LinkProperties;
 import android.net.Network;
 import android.net.NetworkInfo;
-import android.net.wifi.WifiInfo;
-import android.net.wifi.WifiManager;
 
-import org.briarproject.bramble.api.Cancellable;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.event.EventExecutor;
 import org.briarproject.bramble.api.lifecycle.Service;
@@ -24,6 +21,7 @@ import org.briarproject.bramble.api.network.event.NetworkStatusEvent;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.system.TaskScheduler;
+import org.briarproject.bramble.api.system.TaskScheduler.Cancellable;
 
 import java.net.Inet4Address;
 import java.net.InetAddress;
@@ -40,7 +38,6 @@ import javax.annotation.Nullable;
 import javax.inject.Inject;
 
 import static android.content.Context.CONNECTIVITY_SERVICE;
-import static android.content.Context.WIFI_SERVICE;
 import static android.content.Intent.ACTION_SCREEN_OFF;
 import static android.content.Intent.ACTION_SCREEN_ON;
 import static android.net.ConnectivityManager.CONNECTIVITY_ACTION;
@@ -114,37 +111,15 @@ class AndroidNetworkManager implements NetworkManager, Service {
 
 	@Override
 	public NetworkStatus getNetworkStatus() {
-		// https://issuetracker.google.com/issues/175055271
-		try {
-			NetworkInfo net = connectivityManager.getActiveNetworkInfo();
-			boolean connected = net != null && net.isConnected();
-			boolean wifi = false, ipv6Only = false;
-			if (connected) {
-				wifi = net.getType() == TYPE_WIFI;
-				if (SDK_INT >= 23) ipv6Only = isActiveNetworkIpv6Only();
-				else ipv6Only = areAllAvailableNetworksIpv6Only();
-			}
-			return new NetworkStatus(connected, wifi, ipv6Only);
-		} catch (SecurityException e) {
-			logException(LOG, WARNING, e);
-			// Without the ConnectivityManager we can't detect whether we have
-			// internet access. Assume we do, which is probably less harmful
-			// than assuming we don't. Likewise, assume the connection is
-			// IPv6-only. Fall back to the WifiManager to detect whether we
-			// have a wifi connection.
-			LOG.info("ConnectivityManager is broken, guessing connectivity");
-			boolean connected = true, wifi = false, ipv6Only = true;
-			WifiManager wm = (WifiManager) app.getSystemService(WIFI_SERVICE);
-			if (wm != null) {
-				WifiInfo info = wm.getConnectionInfo();
-				if (info != null && info.getIpAddress() != 0) {
-					LOG.info("Connected to wifi");
-					wifi = true;
-					ipv6Only = false;
-				}
-			}
-			return new NetworkStatus(connected, wifi, ipv6Only);
+		NetworkInfo net = connectivityManager.getActiveNetworkInfo();
+		boolean connected = net != null && net.isConnected();
+		boolean wifi = false, ipv6Only = false;
+		if (connected) {
+			wifi = net.getType() == TYPE_WIFI;
+			if (SDK_INT >= 23) ipv6Only = isActiveNetworkIpv6Only();
+			else ipv6Only = areAllAvailableNetworksIpv6Only();
 		}
+		return new NetworkStatus(connected, wifi, ipv6Only);
 	}
 
 	/**
@@ -155,29 +130,23 @@ class AndroidNetworkManager implements NetworkManager, Service {
 	 */
 	@TargetApi(23)
 	private boolean isActiveNetworkIpv6Only() {
-		// https://issuetracker.google.com/issues/175055271
-		try {
-			Network net = connectivityManager.getActiveNetwork();
-			if (net == null) {
-				LOG.info("No active network");
-				return false;
-			}
-			LinkProperties props = connectivityManager.getLinkProperties(net);
-			if (props == null) {
-				LOG.info("No link properties for active network");
-				return false;
-			}
-			boolean hasIpv6Unicast = false;
-			for (LinkAddress linkAddress : props.getLinkAddresses()) {
-				InetAddress addr = linkAddress.getAddress();
-				if (addr instanceof Inet4Address) return false;
-				if (!addr.isMulticastAddress()) hasIpv6Unicast = true;
-			}
-			return hasIpv6Unicast;
-		} catch (SecurityException e) {
-			logException(LOG, WARNING, e);
+		Network net = connectivityManager.getActiveNetwork();
+		if (net == null) {
+			LOG.info("No active network");
 			return false;
 		}
+		LinkProperties props = connectivityManager.getLinkProperties(net);
+		if (props == null) {
+			LOG.info("No link properties for active network");
+			return false;
+		}
+		boolean hasIpv6Unicast = false;
+		for (LinkAddress linkAddress : props.getLinkAddresses()) {
+			InetAddress addr = linkAddress.getAddress();
+			if (addr instanceof Inet4Address) return false;
+			if (!addr.isMulticastAddress()) hasIpv6Unicast = true;
+		}
+		return hasIpv6Unicast;
 	}
 
 	/**

bramble-android/src/main/java/org/briarproject/bramble/plugin/file/AndroidRemovableDrivePlugin.java

@@ -32,22 +32,13 @@ class AndroidRemovableDrivePlugin extends RemovableDrivePlugin {
 	InputStream openInputStream(TransportProperties p) throws IOException {
 		String uri = p.get(PROP_URI);
 		if (isNullOrEmpty(uri)) throw new IllegalArgumentException();
-		try {
-			return app.getContentResolver().openInputStream(Uri.parse(uri));
-		} catch (SecurityException e) {
-			throw new IOException(e);
-		}
+		return app.getContentResolver().openInputStream(Uri.parse(uri));
 	}
 
 	@Override
 	OutputStream openOutputStream(TransportProperties p) throws IOException {
 		String uri = p.get(PROP_URI);
 		if (isNullOrEmpty(uri)) throw new IllegalArgumentException();
-		try {
-			return app.getContentResolver()
-					.openOutputStream(Uri.parse(uri), "wt");
-		} catch (SecurityException e) {
-			throw new IOException(e);
-		}
+		return app.getContentResolver().openOutputStream(Uri.parse(uri), "wt");
 	}
 }

bramble-android/src/main/java/org/briarproject/bramble/plugin/tcp/AndroidLanTcpPlugin.java

@@ -175,24 +175,16 @@ class AndroidLanTcpPlugin extends LanTcpPlugin {
 	@TargetApi(21)
 	@Nullable
 	private InetAddress getWifiClientIpv6Address() {
-		// https://issuetracker.google.com/issues/175055271
-		try {
-			for (Network net : connectivityManager.getAllNetworks()) {
-				NetworkCapabilities caps =
-						connectivityManager.getNetworkCapabilities(net);
-				if (caps == null || !caps.hasTransport(TRANSPORT_WIFI)) {
-					continue;
-				}
-				LinkProperties props =
-						connectivityManager.getLinkProperties(net);
-				if (props == null) continue;
-				for (LinkAddress linkAddress : props.getLinkAddresses()) {
-					InetAddress addr = linkAddress.getAddress();
-					if (isIpv6LinkLocalAddress(addr)) return addr;
-				}
+		for (Network net : connectivityManager.getAllNetworks()) {
+			NetworkCapabilities caps =
+					connectivityManager.getNetworkCapabilities(net);
+			if (caps == null || !caps.hasTransport(TRANSPORT_WIFI)) continue;
+			LinkProperties props = connectivityManager.getLinkProperties(net);
+			if (props == null) continue;
+			for (LinkAddress linkAddress : props.getLinkAddresses()) {
+				InetAddress addr = linkAddress.getAddress();
+				if (isIpv6LinkLocalAddress(addr)) return addr;
 			}
-		} catch (SecurityException e) {
-			logException(LOG, WARNING, e);
 		}
 		return null;
 	}
@@ -235,17 +227,12 @@ class AndroidLanTcpPlugin extends LanTcpPlugin {
 	// network's socket factory may try to connect via another network
 	private SocketFactory getSocketFactory() {
 		if (SDK_INT < 21) return SocketFactory.getDefault();
-		// https://issuetracker.google.com/issues/175055271
-		try {
-			for (Network net : connectivityManager.getAllNetworks()) {
-				NetworkCapabilities caps =
-						connectivityManager.getNetworkCapabilities(net);
-				if (caps != null && caps.hasTransport(TRANSPORT_WIFI)) {
-					return net.getSocketFactory();
-				}
+		for (Network net : connectivityManager.getAllNetworks()) {
+			NetworkCapabilities caps =
+					connectivityManager.getNetworkCapabilities(net);
+			if (caps != null && caps.hasTransport(TRANSPORT_WIFI)) {
+				return net.getSocketFactory();
 			}
-		} catch (SecurityException e) {
-			logException(LOG, WARNING, e);
 		}
 		LOG.warning("Could not find suitable socket factory");
 		return SocketFactory.getDefault();

bramble-android/src/main/java/org/briarproject/bramble/plugin/tor/AndroidTorPluginFactory.java

@@ -11,35 +11,62 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.BackoffFactory;
 import org.briarproject.bramble.api.plugin.PluginCallback;
+import org.briarproject.bramble.api.plugin.TorConstants;
 import org.briarproject.bramble.api.plugin.TorControlPort;
 import org.briarproject.bramble.api.plugin.TorDirectory;
 import org.briarproject.bramble.api.plugin.TorSocksPort;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
 import org.briarproject.bramble.api.system.AndroidWakeLockManager;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.system.LocationUtils;
 import org.briarproject.bramble.api.system.ResourceProvider;
 import org.briarproject.bramble.api.system.WakefulIoExecutor;
+import org.briarproject.bramble.util.AndroidUtils;
 
 import java.io.File;
 import java.util.concurrent.Executor;
+import java.util.logging.Logger;
 
-import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 import javax.net.SocketFactory;
 
-import static org.briarproject.bramble.util.AndroidUtils.getSupportedArchitectures;
-
 @Immutable
 @NotNullByDefault
-public class AndroidTorPluginFactory extends TorPluginFactory {
+public class AndroidTorPluginFactory implements DuplexPluginFactory {
 
+	private static final Logger LOG =
+			Logger.getLogger(AndroidTorPluginFactory.class.getName());
+
+	private static final int MAX_LATENCY = 30 * 1000; // 30 seconds
+	private static final int MAX_IDLE_TIME = 30 * 1000; // 30 seconds
+	private static final int MIN_POLLING_INTERVAL = 60 * 1000; // 1 minute
+	private static final int MAX_POLLING_INTERVAL = 10 * 60 * 1000; // 10 mins
+	private static final double BACKOFF_BASE = 1.2;
+
+	private final Executor ioExecutor, wakefulIoExecutor;
 	private final Application app;
+	private final NetworkManager networkManager;
+	private final LocationUtils locationUtils;
+	private final EventBus eventBus;
+	private final SocketFactory torSocketFactory;
+	private final BackoffFactory backoffFactory;
+	private final ResourceProvider resourceProvider;
+	private final CircumventionProvider circumventionProvider;
+	private final BatteryManager batteryManager;
 	private final AndroidWakeLockManager wakeLockManager;
+	private final Clock clock;
+	private final File torDirectory;
+	private int torSocksPort;
+	private int torControlPort;
+	private final CryptoComponent crypto;
 
 	@Inject
 	AndroidTorPluginFactory(@IoExecutor Executor ioExecutor,
 			@WakefulIoExecutor Executor wakefulIoExecutor,
+			Application app,
 			NetworkManager networkManager,
 			LocationUtils locationUtils,
 			EventBus eventBus,
@@ -48,43 +75,80 @@ public class AndroidTorPluginFactory extends TorPluginFactory {
 			ResourceProvider resourceProvider,
 			CircumventionProvider circumventionProvider,
 			BatteryManager batteryManager,
+			AndroidWakeLockManager wakeLockManager,
 			Clock clock,
-			CryptoComponent crypto,
 			@TorDirectory File torDirectory,
 			@TorSocksPort int torSocksPort,
 			@TorControlPort int torControlPort,
-			Application app,
-			AndroidWakeLockManager wakeLockManager) {
-		super(ioExecutor, wakefulIoExecutor, networkManager, locationUtils,
-				eventBus, torSocketFactory, backoffFactory, resourceProvider,
-				circumventionProvider, batteryManager, clock, crypto,
-				torDirectory, torSocksPort, torControlPort);
+			CryptoComponent crypto) {
+		this.ioExecutor = ioExecutor;
+		this.wakefulIoExecutor = wakefulIoExecutor;
 		this.app = app;
+		this.networkManager = networkManager;
+		this.locationUtils = locationUtils;
+		this.eventBus = eventBus;
+		this.torSocketFactory = torSocketFactory;
+		this.backoffFactory = backoffFactory;
+		this.resourceProvider = resourceProvider;
+		this.circumventionProvider = circumventionProvider;
+		this.batteryManager = batteryManager;
 		this.wakeLockManager = wakeLockManager;
+		this.clock = clock;
+		this.torDirectory = torDirectory;
+		this.torSocksPort = torSocksPort;
+		this.torControlPort = torControlPort;
+		this.crypto = crypto;
 	}
 
-	@Nullable
 	@Override
-	String getArchitectureForTorBinary() {
-		for (String abi : getSupportedArchitectures()) {
-			if (abi.startsWith("x86_64")) return "x86_64_pie";
-			else if (abi.startsWith("x86")) return "x86_pie";
-			else if (abi.startsWith("arm64")) return "arm64_pie";
-			else if (abi.startsWith("armeabi")) return "arm_pie";
+	public TransportId getId() {
+		return TorConstants.ID;
+	}
+
+	@Override
+	public long getMaxLatency() {
+		return MAX_LATENCY;
+	}
+
+	@Override
+	public DuplexPlugin createPlugin(PluginCallback callback) {
+
+		// Check that we have a Tor binary for this architecture
+		String architecture = null;
+		for (String abi : AndroidUtils.getSupportedArchitectures()) {
+			if (abi.startsWith("x86_64")) {
+				architecture = "x86_64";
+				break;
+			} else if (abi.startsWith("x86")) {
+				architecture = "x86";
+				break;
+			} else if (abi.startsWith("arm64")) {
+				architecture = "arm64";
+				break;
+			} else if (abi.startsWith("armeabi")) {
+				architecture = "arm";
+				break;
+			}
 		}
-		return null;
-	}
+		if (architecture == null) {
+			LOG.info("Tor is not supported on this architecture");
+			return null;
+		}
+		// Use position-independent executable
+		architecture += "_pie";
 
-	@Override
-	TorPlugin createPluginInstance(Backoff backoff,
-			TorRendezvousCrypto torRendezvousCrypto, PluginCallback callback,
-			String architecture) {
-		return new AndroidTorPlugin(ioExecutor,
+		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
+				MAX_POLLING_INTERVAL, BACKOFF_BASE);
+		TorRendezvousCrypto torRendezvousCrypto =
+				new TorRendezvousCryptoImpl(crypto);
+		AndroidTorPlugin plugin = new AndroidTorPlugin(ioExecutor,
 				wakefulIoExecutor, app, networkManager, locationUtils,
 				torSocketFactory, clock, resourceProvider,
 				circumventionProvider, batteryManager, wakeLockManager,
 				backoff, torRendezvousCrypto, callback, architecture,
 				MAX_LATENCY, MAX_IDLE_TIME, torDirectory, torSocksPort,
 				torControlPort);
+		eventBus.addListener(plugin);
+		return plugin;
 	}
 }

bramble-android/src/main/java/org/briarproject/bramble/system/AndroidTaskScheduler.java

@@ -8,7 +8,6 @@ import android.content.Intent;
 import android.os.Process;
 import android.os.SystemClock;
 
-import org.briarproject.bramble.api.Cancellable;
 import org.briarproject.bramble.api.lifecycle.Service;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.system.AlarmListener;
@@ -117,12 +116,10 @@ class AndroidTaskScheduler implements TaskScheduler, Service, AlarmListener {
 		long dueMillis = now + MILLISECONDS.convert(delay, unit);
 		Runnable wakeful = () ->
 				wakeLockManager.executeWakefully(task, executor, "TaskHandoff");
-		// Acquire the lock before scheduling the check to ensure the check
-		// doesn't access the task queue before the task has been added
-		ScheduledTask s;
+		Future<?> check = scheduleCheckForDueTasks(delay, unit);
+		ScheduledTask s = new ScheduledTask(wakeful, dueMillis, check,
+				cancelled);
 		synchronized (lock) {
-			Future<?> check = scheduleCheckForDueTasks(delay, unit);
-			s = new ScheduledTask(wakeful, dueMillis, check, cancelled);
 			tasks.add(s);
 		}
 		return s;
@@ -139,7 +136,6 @@ class AndroidTaskScheduler implements TaskScheduler, Service, AlarmListener {
 		return schedule(wrapped, executor, delay, unit, cancelled);
 	}
 
-	@GuardedBy("lock")
 	private Future<?> scheduleCheckForDueTasks(long delay, TimeUnit unit) {
 		Runnable wakeful = () -> wakeLockManager.runWakefully(
 				this::runDueTasks, "TaskScheduler");
@@ -210,7 +206,7 @@ class AndroidTaskScheduler implements TaskScheduler, Service, AlarmListener {
 		private final Future<?> check;
 		private final AtomicBoolean cancelled;
 
-		private ScheduledTask(Runnable task, long dueMillis,
+		public ScheduledTask(Runnable task, long dueMillis,
 				Future<?> check, AtomicBoolean cancelled) {
 			this.task = task;
 			this.dueMillis = dueMillis;

bramble-android/src/main/java/org/briarproject/bramble/util/AndroidUtils.java

@@ -4,7 +4,6 @@ import android.annotation.SuppressLint;
 import android.bluetooth.BluetoothAdapter;
 import android.content.Context;
 import android.os.Build;
-import android.os.Looper;
 import android.provider.Settings;
 
 import org.briarproject.bramble.api.Pair;
@@ -135,8 +134,4 @@ public class AndroidUtils {
 			return null;
 		}
 	}
-
-	public static boolean isUiThread() {
-		return Looper.myLooper() == Looper.getMainLooper();
-	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/Cancellable.java

@@ -1,6 +0,0 @@
-package org.briarproject.bramble.api;
-
-public interface Cancellable {
-
-	void cancel();
-}

bramble-api/src/main/java/org/briarproject/bramble/api/client/ClientHelper.java

@@ -9,8 +9,7 @@ import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.identity.Author;
-import org.briarproject.bramble.api.mailbox.MailboxUpdate;
-import org.briarproject.bramble.api.mailbox.MailboxVersion;
+import org.briarproject.bramble.api.mailbox.MailboxPropertiesUpdate;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.properties.TransportProperties;
@@ -20,9 +19,10 @@ import org.briarproject.bramble.api.sync.MessageId;
 
 import java.security.GeneralSecurityException;
 import java.util.Collection;
-import java.util.List;
 import java.util.Map;
 
+import javax.annotation.Nullable;
+
 @NotNullByDefault
 public interface ClientHelper {
 
@@ -127,17 +127,16 @@ public interface ClientHelper {
 			BdfDictionary properties) throws FormatException;
 
 	/**
-	 * Parse and validate the elements of a Mailbox update message.
+	 * Parse and validate the property dictionary of a Mailbox property update
+	 * message.
 	 *
-	 * @return the parsed update message
-	 * @throws FormatException if the message elements are invalid
+	 * @return the properties for using the Mailbox, or null if there is no
+	 * Mailbox available
+	 * @throws FormatException if the properties are not valid
 	 */
-	MailboxUpdate parseAndValidateMailboxUpdate(BdfList clientSupports,
-			BdfList serverSupports, BdfDictionary properties)
-			throws FormatException;
-
-	List<MailboxVersion> parseMailboxVersionList(BdfList bdfList)
-			throws FormatException;
+	@Nullable
+	MailboxPropertiesUpdate parseAndValidateMailboxPropertiesUpdate(
+			BdfDictionary properties) throws FormatException;
 
 	/**
 	 * Retrieves the contact ID from the group metadata of the given contact

bramble-api/src/main/java/org/briarproject/bramble/api/connection/ConnectionManager.java

@@ -7,7 +7,6 @@ import org.briarproject.bramble.api.plugin.TransportConnectionReader;
 import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.sync.OutgoingSessionRecord;
 
 @NotNullByDefault
 public interface ConnectionManager {
@@ -17,17 +16,6 @@ public interface ConnectionManager {
 	 */
 	void manageIncomingConnection(TransportId t, TransportConnectionReader r);
 
-	/**
-	 * Manages an incoming connection from a contact via a mailbox.
-	 * <p>
-	 * This method does not mark the tag as recognised until after the data
-	 * has been read from the {@link TransportConnectionReader}, at which
-	 * point the {@link TagController} is called to decide whether the tag
-	 * should be marked as recognised.
-	 */
-	void manageIncomingConnection(TransportId t, TransportConnectionReader r,
-			TagController c);
-
 	/**
 	 * Manages an incoming connection from a contact over a duplex transport.
 	 */
@@ -46,14 +34,6 @@ public interface ConnectionManager {
 	void manageOutgoingConnection(ContactId c, TransportId t,
 			TransportConnectionWriter w);
 
-	/**
-	 * Manages an outgoing connection to a contact via a mailbox. The IDs of
-	 * any messages sent or acked are added to the given
-	 * {@link OutgoingSessionRecord}.
-	 */
-	void manageOutgoingConnection(ContactId c, TransportId t,
-			TransportConnectionWriter w, OutgoingSessionRecord sessionRecord);
-
 	/**
 	 * Manages an outgoing connection to a contact over a duplex transport.
 	 */
@@ -66,21 +46,4 @@ public interface ConnectionManager {
 	 */
 	void manageOutgoingConnection(PendingContactId p, TransportId t,
 			DuplexTransportConnection d);
-
-	/**
-	 * An interface for controlling whether a tag should be marked as
-	 * recognised.
-	 */
-	interface TagController {
-		/**
-		 * This method is only called if a tag was read from the corresponding
-		 * {@link TransportConnectionReader} and recognised.
-		 *
-		 * @param exception True if an exception was thrown while reading from
-		 * the {@link TransportConnectionReader}, after successfully reading
-		 * and recognising the tag.
-		 * @return True if the tag should be marked as recognised.
-		 */
-		boolean shouldMarkTagAsRecognised(boolean exception);
-	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/db/DatabaseComponent.java

@@ -33,18 +33,11 @@ import java.util.List;
 import java.util.Map;
 
 import javax.annotation.Nullable;
-import javax.annotation.concurrent.ThreadSafe;
 
 /**
  * Encapsulates the database implementation and exposes high-level operations
  * to other components.
- * <p>
- * With the exception of the {@link #open(SecretKey, MigrationListener)} and
- * {@link #close()} methods, which must not be called concurrently, the
- * database can be accessed from any thread. See {@link TransactionManager}
- * for locking behaviour.
  */
-@ThreadSafe
 @NotNullByDefault
 public interface DatabaseComponent extends TransactionManager {
 
@@ -126,11 +119,16 @@ public interface DatabaseComponent extends TransactionManager {
 			TransportKeys k) throws DbException;
 
 	/**
-	 * Returns true if there are any acks to send to the given contact.
+	 * Returns true if there are any acks or messages to send to the given
+	 * contact over a transport with the given maximum latency.
 	 * <p/>
 	 * Read-only.
+	 *
+	 * @param eager True if messages that are not yet due for retransmission
+	 * should be included
 	 */
-	boolean containsAcksToSend(Transaction txn, ContactId c) throws DbException;
+	boolean containsAnythingToSend(Transaction txn, ContactId c,
+			long maxLatency, boolean eager) throws DbException;
 
 	/**
 	 * Returns true if the database contains the given contact for the given
@@ -156,18 +154,6 @@ public interface DatabaseComponent extends TransactionManager {
 	 */
 	boolean containsIdentity(Transaction txn, AuthorId a) throws DbException;
 
-	/**
-	 * Returns true if there are any messages to send to the given contact
-	 * over a transport with the given maximum latency.
-	 * <p/>
-	 * Read-only.
-	 *
-	 * @param eager True if messages that are not yet due for retransmission
-	 * should be included
-	 */
-	boolean containsMessagesToSend(Transaction txn, ContactId c,
-			long maxLatency, boolean eager) throws DbException;
-
 	/**
 	 * Returns true if the database contains the given pending contact.
 	 * <p/>
@@ -207,15 +193,26 @@ public interface DatabaseComponent extends TransactionManager {
 			throws DbException;
 
 	/**
-	 * Returns a batch of messages for the given contact, for transmission over
-	 * a transport with the given maximum latency. The total length of the
-	 * messages, including record headers, will be no more than the given
-	 * capacity. Returns null if there are no sendable messages that would fit
-	 * in the given capacity.
+	 * Returns a batch of messages for the given contact, with a total length
+	 * less than or equal to the given length, for transmission over a
+	 * transport with the given maximum latency. Returns null if there are no
+	 * sendable messages that fit in the given length.
 	 */
 	@Nullable
 	Collection<Message> generateBatch(Transaction txn, ContactId c,
-			long capacity, long maxLatency) throws DbException;
+			int maxLength, long maxLatency) throws DbException;
+
+	/**
+	 * Returns a batch of messages for the given contact containing the
+	 * messages with the given IDs, for transmission over a transport with
+	 * the given maximum latency.
+	 * <p/>
+	 * If any of the given messages are not in the database or are not visible
+	 * to the contact, they are omitted from the batch without throwing an
+	 * exception.
+	 */
+	Collection<Message> generateBatch(Transaction txn, ContactId c,
+			Collection<MessageId> ids, long maxLatency) throws DbException;
 
 	/**
 	 * Returns an offer for the given contact for transmission over a
@@ -235,16 +232,15 @@ public interface DatabaseComponent extends TransactionManager {
 			throws DbException;
 
 	/**
-	 * Returns a batch of messages for the given contact, for transmission over
-	 * a transport with the given maximum latency. Only messages that have been
-	 * requested by the contact are returned. The total length of the messages,
-	 * including record headers, will be no more than the given capacity.
-	 * Returns null if there are no sendable messages that have been requested
-	 * by the contact and would fit in the given capacity.
+	 * Returns a batch of messages for the given contact, with a total length
+	 * less than or equal to the given length, for transmission over a
+	 * transport with the given maximum latency. Only messages that have been
+	 * requested by the contact are returned. Returns null if there are no
+	 * sendable messages that fit in the given length.
 	 */
 	@Nullable
 	Collection<Message> generateRequestedBatch(Transaction txn, ContactId c,
-			long capacity, long maxLatency) throws DbException;
+			int maxLength, long maxLatency) throws DbException;
 
 	/**
 	 * Returns the contact with the given ID.
@@ -348,30 +344,6 @@ public interface DatabaseComponent extends TransactionManager {
 	Collection<MessageId> getMessageIds(Transaction txn, GroupId g,
 			Metadata query) throws DbException;
 
-	/**
-	 * Returns the IDs of some messages received from the given contact that
-	 * need to be acknowledged, up to the given number of messages.
-	 * <p/>
-	 * Read-only.
-	 */
-	Collection<MessageId> getMessagesToAck(Transaction txn, ContactId c,
-			int maxMessages) throws DbException;
-
-	/**
-	 * Returns the IDs of some messages that are eligible to be sent to the
-	 * given contact over a transport with the given maximum latency. The total
-	 * length of the messages including record headers will be no more than the
-	 * given capacity.
-	 * <p/>
-	 * Unlike {@link #getUnackedMessagesToSend(Transaction, ContactId)} this
-	 * method does not return messages that have already been sent unless they
-	 * are due for retransmission.
-	 * <p/>
-	 * Read-only.
-	 */
-	Collection<MessageId> getMessagesToSend(Transaction txn, ContactId c,
-			long capacity, long maxLatency) throws DbException;
-
 	/**
 	 * Returns the IDs of any messages that need to be validated.
 	 * <p/>
@@ -488,30 +460,15 @@ public interface DatabaseComponent extends TransactionManager {
 	MessageStatus getMessageStatus(Transaction txn, ContactId c, MessageId m)
 			throws DbException;
 
-	/**
-	 * Returns the message with the given ID for transmission to the given
-	 * contact over a transport with the given maximum latency. Returns null
-	 * if the message is no longer visible to the contact.
-	 *
-	 * @param markAsSent True if the message should be marked as sent.
-	 * If false it can be marked as sent by calling
-	 * {@link #setMessagesSent(Transaction, ContactId, Collection, long)}.
-	 */
-	@Nullable
-	Message getMessageToSend(Transaction txn, ContactId c, MessageId m,
-			long maxLatency, boolean markAsSent) throws DbException;
-
 	/**
 	 * Returns the IDs of all messages that are eligible to be sent to the
-	 * given contact.
-	 * <p>
-	 * Unlike {@link #getMessagesToSend(Transaction, ContactId, long, long)}
-	 * this method may return messages that have already been sent and are
-	 * not yet due for retransmission.
+	 * given contact, together with their raw lengths. This may include
+	 * messages that have already been sent and are not yet due for
+	 * retransmission.
 	 * <p/>
 	 * Read-only.
 	 */
-	Collection<MessageId> getUnackedMessagesToSend(Transaction txn,
+	Map<MessageId, Integer> getUnackedMessagesToSend(Transaction txn,
 			ContactId c) throws DbException;
 
 	/**
@@ -541,18 +498,15 @@ public interface DatabaseComponent extends TransactionManager {
 	 */
 	long getNextCleanupDeadline(Transaction txn) throws DbException;
 
-	/**
+	/*
 	 * Returns the next time (in milliseconds since the Unix epoch) when a
-	 * message is due to be sent to the given contact over a transport with
-	 * the given latency.
-	 * <p>
-	 * The returned value may be zero if a message is due to be sent
-	 * immediately, or Long.MAX_VALUE if no messages are scheduled to be sent.
+	 * message is due to be sent to the given contact. The returned value may
+	 * be zero if a message is due to be sent immediately, or Long.MAX_VALUE if
+	 * no messages are scheduled to be sent.
 	 * <p/>
 	 * Read-only.
 	 */
-	long getNextSendTime(Transaction txn, ContactId c, long maxLatency)
-			throws DbException;
+	long getNextSendTime(Transaction txn, ContactId c) throws DbException;
 
 	/**
 	 * Returns the pending contact with the given ID.
@@ -694,13 +648,6 @@ public interface DatabaseComponent extends TransactionManager {
 	void removeTransportKeys(Transaction txn, TransportId t, KeySetId k)
 			throws DbException;
 
-	/**
-	 * Records an ack for the given messages as having been sent to the given
-	 * contact.
-	 */
-	void setAckSent(Transaction txn, ContactId c, Collection<MessageId> acked)
-			throws DbException;
-
 	/**
 	 * Sets the cleanup timer duration for the given message. This does not
 	 * start the message's cleanup timer.
@@ -747,13 +694,6 @@ public interface DatabaseComponent extends TransactionManager {
 	void setMessageState(Transaction txn, MessageId m, MessageState state)
 			throws DbException;
 
-	/**
-	 * Records the given messages as having been sent to the given contact
-	 * over a transport with the given maximum latency.
-	 */
-	void setMessagesSent(Transaction txn, ContactId c,
-			Collection<MessageId> sent, long maxLatency) throws DbException;
-
 	/**
 	 * Adds dependencies for a message
 	 */
@@ -806,4 +746,6 @@ public interface DatabaseComponent extends TransactionManager {
 	 */
 	void updateTransportKeys(Transaction txn, Collection<TransportKeySet> keys)
 			throws DbException;
+
+	void printStats(Transaction txn) throws DbException;
 }

bramble-api/src/main/java/org/briarproject/bramble/api/db/DatabaseExecutor.java

@@ -18,10 +18,6 @@ import static java.lang.annotation.RetentionPolicy.RUNTIME;
  * submitted, tasks are not run concurrently, and submitting a task will never
  * block. Tasks must not run indefinitely. Tasks submitted during shutdown are
  * discarded.
- * <p>
- * It is not mandatory to use this executor for database tasks. The database
- * can be accessed from any thread, but this executor's guarantee that tasks
- * are run in the order they're submitted may be useful in some cases.
  */
 @Qualifier
 @Target({FIELD, METHOD, PARAMETER})

bramble-api/src/main/java/org/briarproject/bramble/api/db/Transaction.java

@@ -45,9 +45,6 @@ public class Transaction {
 	/**
 	 * Attaches an event to be broadcast when the transaction has been
 	 * committed. The event will be broadcast on the {@link EventExecutor}.
-	 * Events and {@link #attach(Runnable) tasks} are submitted to the
-	 * {@link EventExecutor} in the order they were attached to the
-	 * transaction.
 	 */
 	public void attach(Event e) {
 		if (actions == null) actions = new ArrayList<>();
@@ -57,9 +54,6 @@ public class Transaction {
 	/**
 	 * Attaches a task to be executed when the transaction has been
 	 * committed. The task will be run on the {@link EventExecutor}.
-	 * {@link #attach(Event) Events} and tasks are submitted to the
-	 * {@link EventExecutor} in the order they were attached to the
-	 * transaction.
 	 */
 	public void attach(Runnable r) {
 		if (actions == null) actions = new ArrayList<>();

bramble-api/src/main/java/org/briarproject/bramble/api/db/TransactionManager.java

@@ -1,95 +1,51 @@
 package org.briarproject.bramble.api.db;
 
-import org.briarproject.bramble.api.event.EventExecutor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import javax.annotation.Nullable;
-import javax.annotation.concurrent.ThreadSafe;
 
-/**
- * An interface for managing database transactions.
- * <p>
- * Read-only transactions may access the database concurrently. Read-write
- * transactions access the database exclusively, so starting a read-only or
- * read-write transaction will block until there are no read-write
- * transactions in progress.
- * <p>
- * Failing to {@link #endTransaction(Transaction) end} a transaction will
- * prevent other callers from accessing the database, so it is recommended to
- * use the {@link #transaction(boolean, DbRunnable)},
- * {@link #transactionWithResult(boolean, DbCallable)} and
- * {@link #transactionWithNullableResult(boolean, NullableDbCallable)} methods
- * where possible, which handle committing or aborting the transaction on the
- * caller's behalf.
- * <p>
- * Transactions are not reentrant, i.e. it is not permitted to start a
- * transaction on a thread that already has a transaction in progress.
- */
-@ThreadSafe
 @NotNullByDefault
 public interface TransactionManager {
 
 	/**
-	 * Starts a new transaction and returns an object representing it. This
-	 * method acquires the database lock, which is held until
-	 * {@link #endTransaction(Transaction)} is called.
+	 * Starts a new transaction and returns an object representing it.
+	 * <p/>
+	 * This method acquires locks, so it must not be called while holding a
+	 * lock.
 	 *
-	 * @param readOnly True if the transaction will only be used for reading,
-	 * in which case the database lock can be shared with other read-only
-	 * transactions.
+	 * @param readOnly true if the transaction will only be used for reading.
 	 */
 	Transaction startTransaction(boolean readOnly) throws DbException;
 
 	/**
 	 * Commits a transaction to the database.
-	 * {@link #endTransaction(Transaction)} must be called to release the
-	 * database lock.
 	 */
 	void commitTransaction(Transaction txn) throws DbException;
 
 	/**
-	 * Ends a transaction. If the transaction has not been committed by
-	 * calling {@link #commitTransaction(Transaction)}, it is aborted and the
-	 * database lock is released.
-	 * <p>
-	 * If the transaction has been committed, any
-	 * {@link Transaction#attach events} attached to the transaction are
-	 * broadcast and any {@link Transaction#attach(Runnable) tasks} attached
-	 * to the transaction are submitted to the {@link EventExecutor}. The
-	 * database lock is then released.
+	 * Ends a transaction. If the transaction has not been committed,
+	 * it will be aborted. If the transaction has been committed,
+	 * any events attached to the transaction are broadcast.
+	 * The database lock will be released in either case.
 	 */
 	void endTransaction(Transaction txn);
 
 	/**
-	 * Runs the given task within a transaction. The database lock is held
-	 * while running the task.
-	 *
-	 * @param readOnly True if the transaction will only be used for reading,
-	 * in which case the database lock can be shared with other read-only
-	 * transactions.
+	 * Runs the given task within a transaction.
 	 */
 	<E extends Exception> void transaction(boolean readOnly,
 			DbRunnable<E> task) throws DbException, E;
 
 	/**
 	 * Runs the given task within a transaction and returns the result of the
-	 * task. The database lock is held while running the task.
-	 *
-	 * @param readOnly True if the transaction will only be used for reading,
-	 * in which case the database lock can be shared with other read-only
-	 * transactions.
+	 * task.
 	 */
 	<R, E extends Exception> R transactionWithResult(boolean readOnly,
 			DbCallable<R, E> task) throws DbException, E;
 
 	/**
 	 * Runs the given task within a transaction and returns the result of the
-	 * task, which may be null. The database lock is held while running the
-	 * task.
-	 *
-	 * @param readOnly True if the transaction will only be used for reading,
-	 * in which case the database lock can be shared with other read-only
-	 * transactions.
+	 * task, which may be null.
 	 */
 	@Nullable
 	<R, E extends Exception> R transactionWithNullableResult(boolean readOnly,

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

@@ -1,73 +0,0 @@
-package org.briarproject.bramble.api.mailbox;
-
-import org.briarproject.bramble.api.plugin.TransportId;
-
-import java.util.List;
-
-import static java.util.Collections.singletonList;
-import static java.util.concurrent.TimeUnit.DAYS;
-import static java.util.concurrent.TimeUnit.HOURS;
-import static org.briarproject.bramble.api.transport.TransportConstants.MAX_FRAME_LENGTH;
-import static org.briarproject.bramble.api.transport.TransportConstants.MAX_PAYLOAD_LENGTH;
-import static org.briarproject.bramble.api.transport.TransportConstants.STREAM_HEADER_LENGTH;
-import static org.briarproject.bramble.api.transport.TransportConstants.TAG_LENGTH;
-
-public interface MailboxConstants {
-
-	/**
-	 * The transport ID of the mailbox plugin.
-	 */
-	TransportId ID = new TransportId("org.briarproject.bramble.mailbox");
-
-	/**
-	 * Mailbox API versions that we support as a client. This is reported to our
-	 * contacts by {@link MailboxUpdateManager}.
-	 */
-	List<MailboxVersion> CLIENT_SUPPORTS = singletonList(
-			new MailboxVersion(1, 0));
-
-	/**
-	 * The constant returned by
-	 * {@link MailboxHelper#getHighestCommonMajorVersion(List, List)}
-	 * when the server is too old to support our major version.
-	 */
-	int API_SERVER_TOO_OLD = -1;
-
-	/**
-	 * The constant returned by
-	 * {@link MailboxHelper#getHighestCommonMajorVersion(List, List)}
-	 * when we as a client are too old to support the server's major version.
-	 */
-	int API_CLIENT_TOO_OLD = -2;
-
-	/**
-	 * The maximum length of a file that can be uploaded to or downloaded from
-	 * a mailbox.
-	 */
-	int MAX_FILE_BYTES = 1024 * 1024;
-
-	/**
-	 * The maximum length of the plaintext payload of a file, such that the
-	 * ciphertext is no more than {@link #MAX_FILE_BYTES}.
-	 */
-	int MAX_FILE_PAYLOAD_BYTES =
-			(MAX_FILE_BYTES - TAG_LENGTH - STREAM_HEADER_LENGTH)
-					/ MAX_FRAME_LENGTH * MAX_PAYLOAD_LENGTH;
-
-	/**
-	 * The number of connection failures
-	 * that indicate a problem with the mailbox.
-	 */
-	int PROBLEM_NUM_CONNECTION_FAILURES = 5;
-
-	/**
-	 * The time in milliseconds since the last connection success
-	 * that need to pass to indicates a problem with the mailbox.
-	 */
-	long PROBLEM_MS_SINCE_LAST_SUCCESS = HOURS.toMillis(1);
-
-	/**
-	 * The maximum latency of the mailbox transport in milliseconds.
-	 */
-	long MAX_LATENCY = DAYS.toMillis(14);
-}

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

@@ -1,22 +0,0 @@
-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-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxHelper.java

@@ -1,35 +0,0 @@
-package org.briarproject.bramble.api.mailbox;
-
-import java.util.List;
-import java.util.TreeSet;
-
-import static org.briarproject.bramble.api.mailbox.MailboxConstants.API_CLIENT_TOO_OLD;
-import static org.briarproject.bramble.api.mailbox.MailboxConstants.API_SERVER_TOO_OLD;
-
-class MailboxHelper {
-
-	/**
-	 * Returns the highest major version that both client and server support
-	 * or {@link MailboxConstants#API_SERVER_TOO_OLD} if the server is too old
-	 * or {@link MailboxConstants#API_CLIENT_TOO_OLD} if the client is too old.
-	 */
-	static int getHighestCommonMajorVersion(
-			List<MailboxVersion> client, List<MailboxVersion> server) {
-		TreeSet<Integer> clientVersions = new TreeSet<>();
-		for (MailboxVersion version : client) {
-			clientVersions.add(version.getMajor());
-		}
-		TreeSet<Integer> serverVersions = new TreeSet<>();
-		for (MailboxVersion version : server) {
-			serverVersions.add(version.getMajor());
-		}
-		for (int clientVersion : clientVersions.descendingSet()) {
-			if (serverVersions.contains(clientVersion)) return clientVersion;
-		}
-		if (clientVersions.last() < serverVersions.last()) {
-			return API_CLIENT_TOO_OLD;
-		}
-		return API_SERVER_TOO_OLD;
-	}
-
-}

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

@@ -2,7 +2,6 @@ package org.briarproject.bramble.api.mailbox;
 
 import com.fasterxml.jackson.annotation.JsonValue;
 
-import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.UniqueId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
@@ -33,7 +32,7 @@ public abstract class MailboxId extends UniqueId {
 		}
 		try {
 			return fromHexString(token);
-		} catch (FormatException e) {
+		} catch (IllegalArgumentException e) {
 			throw new InvalidMailboxIdException();
 		}
 	}

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

@@ -2,8 +2,6 @@ package org.briarproject.bramble.api.mailbox;
 
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Transaction;
-import org.briarproject.bramble.api.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.mailbox.event.OwnMailboxConnectionStatusEvent;
 
 import javax.annotation.Nullable;
 
@@ -43,14 +41,4 @@ public interface MailboxManager {
 	 */
 	boolean checkConnection();
 
-	/**
-	 * Unpairs the owner's mailbox and tries to wipe it.
-	 * As this makes a network call, it should be run on the {@link IoExecutor}.
-	 *
-	 * @return true if we could wipe the mailbox, false if we couldn't.
-	 * It is advised to inform the user to wipe the mailbox themselves,
-	 * if we failed to wipe it.
-	 */
-	@IoExecutor
-	boolean unPair() throws DbException;
 }

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

@@ -4,54 +4,32 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import java.util.List;
 
-import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 
 @Immutable
 @NotNullByDefault
 public class MailboxProperties {
 
-	private final String onion;
+	private final String baseUrl;
 	private final MailboxAuthToken authToken;
 	private final boolean owner;
 	private final List<MailboxVersion> serverSupports;
-	@Nullable
-	private final MailboxFolderId inboxId; // Null for own mailbox
-	@Nullable
-	private final MailboxFolderId outboxId; // Null for own mailbox
 
-	/**
-	 * Constructor for properties used by the mailbox's owner.
-	 */
-	public MailboxProperties(String onion, MailboxAuthToken authToken,
-			List<MailboxVersion> serverSupports) {
-		this.onion = onion;
+	public MailboxProperties(String baseUrl, MailboxAuthToken authToken,
+			boolean owner, List<MailboxVersion> serverSupports) {
+		this.baseUrl = baseUrl;
 		this.authToken = authToken;
-		this.owner = true;
+		this.owner = owner;
 		this.serverSupports = serverSupports;
-		this.inboxId = null;
-		this.outboxId = null;
 	}
 
-	/**
-	 * Constructor for properties used by a contact of the mailbox's owner.
-	 */
-	public MailboxProperties(String onion, MailboxAuthToken authToken,
-			List<MailboxVersion> serverSupports, MailboxFolderId inboxId,
-			MailboxFolderId outboxId) {
-		this.onion = onion;
-		this.authToken = authToken;
-		this.owner = false;
-		this.serverSupports = serverSupports;
-		this.inboxId = inboxId;
-		this.outboxId = outboxId;
+	public String getBaseUrl() {
+		return baseUrl;
 	}
 
-	/**
-	 * Returns the onion address of the mailbox, excluding the .onion suffix.
-	 */
 	public String getOnion() {
-		return onion;
+		return baseUrl.replaceFirst("^http://", "")
+				.replaceFirst("\\.onion$", "");
 	}
 
 	public MailboxAuthToken getAuthToken() {
@@ -65,14 +43,4 @@ public class MailboxProperties {
 	public List<MailboxVersion> getServerSupports() {
 		return serverSupports;
 	}
-
-	@Nullable
-	public MailboxFolderId getInboxId() {
-		return inboxId;
-	}
-
-	@Nullable
-	public MailboxFolderId getOutboxId() {
-		return outboxId;
-	}
 }

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

@@ -0,0 +1,41 @@
+package org.briarproject.bramble.api.mailbox;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+@Immutable
+@NotNullByDefault
+public class MailboxPropertiesUpdate {
+
+	private final String onion;
+	private final MailboxAuthToken authToken;
+	private final MailboxFolderId inboxId;
+	private final MailboxFolderId outboxId;
+
+	public MailboxPropertiesUpdate(String onion,
+			MailboxAuthToken authToken, MailboxFolderId inboxId,
+			MailboxFolderId outboxId) {
+		this.onion = onion;
+		this.authToken = authToken;
+		this.inboxId = inboxId;
+		this.outboxId = outboxId;
+	}
+
+	public String getOnion() {
+		return onion;
+	}
+
+	public MailboxAuthToken getAuthToken() {
+		return authToken;
+	}
+
+	public MailboxFolderId getInboxId() {
+		return inboxId;
+	}
+
+	public MailboxFolderId getOutboxId() {
+		return outboxId;
+	}
+
+}

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

@@ -0,0 +1,67 @@
+package org.briarproject.bramble.api.mailbox;
+
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.db.Transaction;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.ClientId;
+
+import javax.annotation.Nullable;
+
+@NotNullByDefault
+public interface MailboxPropertyManager {
+
+	/**
+	 * The unique ID of the mailbox property client.
+	 */
+	ClientId CLIENT_ID =
+			new ClientId("org.briarproject.bramble.mailbox.properties");
+
+	/**
+	 * The current major version of the mailbox property client.
+	 */
+	int MAJOR_VERSION = 0;
+
+	/**
+	 * The current minor version of the mailbox property client.
+	 */
+	int MINOR_VERSION = 0;
+
+	/**
+	 * The number of properties required for a (non-empty) update message.
+	 */
+	int PROP_COUNT = 4;
+
+	/**
+	 * The required properties of a non-empty update message.
+	 */
+	String PROP_KEY_ONION = "onion";
+	String PROP_KEY_AUTHTOKEN = "authToken";
+	String PROP_KEY_INBOXID = "inboxId";
+	String PROP_KEY_OUTBOXID = "outboxId";
+
+	/**
+	 * Length of the Onion property.
+	 */
+	int PROP_ONION_LENGTH = 56;
+
+	/**
+	 * Message metadata key for the version number of a local or remote update,
+	 * as a BDF long.
+	 */
+	String MSG_KEY_VERSION = "version";
+
+	/**
+	 * Message metadata key for whether an update is local or remote, as a BDF
+	 * boolean.
+	 */
+	String MSG_KEY_LOCAL = "local";
+
+	@Nullable
+	MailboxPropertiesUpdate getLocalProperties(Transaction txn, ContactId c)
+			throws DbException;
+
+	@Nullable
+	MailboxPropertiesUpdate getRemoteProperties(Transaction txn, ContactId c)
+			throws DbException;
+}

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

@@ -7,8 +7,6 @@ import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
-import java.util.List;
-
 import javax.annotation.Nullable;
 
 @NotNullByDefault
@@ -28,16 +26,11 @@ public interface MailboxSettingsManager {
 	void setOwnMailboxProperties(Transaction txn, MailboxProperties p)
 			throws DbException;
 
-	void removeOwnMailboxProperties(Transaction txn) throws DbException;
-
 	MailboxStatus getOwnMailboxStatus(Transaction txn) throws DbException;
 
 	void recordSuccessfulConnection(Transaction txn, long now)
 			throws DbException;
 
-	void recordSuccessfulConnection(Transaction txn, long now,
-			List<MailboxVersion> versions) throws DbException;
-
 	void recordFailedConnectionAttempt(Transaction txn, long now)
 			throws DbException;
 
@@ -54,8 +47,7 @@ public interface MailboxSettingsManager {
 		 * @param txn A read-write transaction
 		 * @param ownOnion Our new mailbox's onion (56 base32 chars)
 		 */
-		void mailboxPaired(Transaction txn, String ownOnion,
-				List<MailboxVersion> serverSupports)
+		void mailboxPaired(Transaction txn, String ownOnion)
 				throws DbException;
 
 		/**

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

@@ -2,30 +2,20 @@ package org.briarproject.bramble.api.mailbox;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
-import java.util.List;
-
 import javax.annotation.concurrent.Immutable;
 
-import static org.briarproject.bramble.api.mailbox.MailboxConstants.CLIENT_SUPPORTS;
-import static org.briarproject.bramble.api.mailbox.MailboxConstants.PROBLEM_MS_SINCE_LAST_SUCCESS;
-import static org.briarproject.bramble.api.mailbox.MailboxConstants.PROBLEM_NUM_CONNECTION_FAILURES;
-import static org.briarproject.bramble.api.mailbox.MailboxHelper.getHighestCommonMajorVersion;
-
 @Immutable
 @NotNullByDefault
 public class MailboxStatus {
 
 	private final long lastAttempt, lastSuccess;
 	private final int attemptsSinceSuccess;
-	private final List<MailboxVersion> serverSupports;
 
 	public MailboxStatus(long lastAttempt, long lastSuccess,
-			int attemptsSinceSuccess,
-			List<MailboxVersion> serverSupports) {
+			int attemptsSinceSuccess) {
 		this.lastAttempt = lastAttempt;
 		this.lastSuccess = lastSuccess;
 		this.attemptsSinceSuccess = attemptsSinceSuccess;
-		this.serverSupports = serverSupports;
 	}
 
 	/**
@@ -66,21 +56,4 @@ public class MailboxStatus {
 	public int getAttemptsSinceSuccess() {
 		return attemptsSinceSuccess;
 	}
-
-	/**
-	 * @return true if this status indicates a problem with the mailbox.
-	 */
-	public boolean hasProblem(long now) {
-		return attemptsSinceSuccess >= PROBLEM_NUM_CONNECTION_FAILURES &&
-				(now - lastSuccess) >= PROBLEM_MS_SINCE_LAST_SUCCESS;
-	}
-
-	/**
-	 * @return a positive integer if the mailbox is compatible. Same result as
-	 * {@link MailboxHelper#getHighestCommonMajorVersion(List, List)}.
-	 */
-	public int getMailboxCompatibility() {
-		return getHighestCommonMajorVersion(CLIENT_SUPPORTS, serverSupports);
-	}
-
 }

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

@@ -1,31 +0,0 @@
-package org.briarproject.bramble.api.mailbox;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import java.util.List;
-
-import javax.annotation.concurrent.Immutable;
-
-@Immutable
-@NotNullByDefault
-public class MailboxUpdate {
-	private final boolean hasMailbox;
-	private final List<MailboxVersion> clientSupports;
-
-	public MailboxUpdate(List<MailboxVersion> clientSupports) {
-		this(clientSupports, false);
-	}
-
-	MailboxUpdate(List<MailboxVersion> clientSupports, boolean hasMailbox) {
-		this.clientSupports = clientSupports;
-		this.hasMailbox = hasMailbox;
-	}
-
-	public List<MailboxVersion> getClientSupports() {
-		return clientSupports;
-	}
-
-	public boolean hasMailbox() {
-		return hasMailbox;
-	}
-}

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

@@ -1,105 +0,0 @@
-package org.briarproject.bramble.api.mailbox;
-
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.db.Transaction;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.ClientId;
-
-import javax.annotation.Nullable;
-
-@NotNullByDefault
-public interface MailboxUpdateManager {
-
-	/**
-	 * The unique ID of the mailbox update (properties) client.
-	 */
-	ClientId CLIENT_ID =
-			new ClientId("org.briarproject.bramble.mailbox.properties");
-
-	/**
-	 * The current major version of the mailbox update (properties) client.
-	 */
-	int MAJOR_VERSION = 2;
-
-	/**
-	 * The current minor version of the mailbox update (properties) client.
-	 */
-	int MINOR_VERSION = 0;
-
-	/**
-	 * The number of properties required for an update message with a mailbox.
-	 * <p>
-	 * The required properties are {@link #PROP_KEY_ONION},
-	 * {@link #PROP_KEY_AUTHTOKEN}, {@link #PROP_KEY_INBOXID} and
-	 * {@link #PROP_KEY_OUTBOXID}.
-	 */
-	int PROP_COUNT = 4;
-
-	/**
-	 * The onion address of the mailbox, excluding the .onion suffix.
-	 */
-	String PROP_KEY_ONION = "onion";
-
-	/**
-	 * A bearer token for accessing the mailbox (64 hex digits).
-	 */
-	String PROP_KEY_AUTHTOKEN = "authToken";
-
-	/**
-	 * A folder ID for downloading messages (64 hex digits).
-	 */
-	String PROP_KEY_INBOXID = "inboxId";
-
-	/**
-	 * A folder ID for uploading messages (64 hex digits).
-	 */
-	String PROP_KEY_OUTBOXID = "outboxId";
-
-	/**
-	 * Length of the {@link #PROP_KEY_ONION} property.
-	 */
-	int PROP_ONION_LENGTH = 56;
-
-	/**
-	 * Message metadata key for the version number of a local or remote update,
-	 * as a BDF long.
-	 */
-	String MSG_KEY_VERSION = "version";
-
-	/**
-	 * Message metadata key for whether an update is local or remote, as a BDF
-	 * boolean.
-	 */
-	String MSG_KEY_LOCAL = "local";
-
-	/**
-	 * Key in the client's local group for storing the clientSupports list that
-	 * was last sent out.
-	 */
-	String GROUP_KEY_SENT_CLIENT_SUPPORTS = "sentClientSupports";
-
-	/**
-	 * Returns the latest {@link MailboxUpdate} sent to the given contact.
-	 * <p>
-	 * If we have our own mailbox then the update will be a
-	 * {@link MailboxUpdateWithMailbox} containing the
-	 * {@link MailboxProperties} the contact should use for communicating with
-	 * our mailbox.
-	 */
-	MailboxUpdate getLocalUpdate(Transaction txn, ContactId c)
-			throws DbException;
-
-	/**
-	 * Returns the latest {@link MailboxUpdate} received from the given
-	 * contact, or null if no update has been received.
-	 * <p>
-	 * If the contact has a mailbox then the update will be a
-	 * {@link MailboxUpdateWithMailbox} containing the
-	 * {@link MailboxProperties} we should use for communicating with the
-	 * contact's mailbox.
-	 */
-	@Nullable
-	MailboxUpdate getRemoteUpdate(Transaction txn, ContactId c)
-			throws DbException;
-}

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

@@ -1,30 +0,0 @@
-package org.briarproject.bramble.api.mailbox;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import java.util.List;
-
-import javax.annotation.concurrent.Immutable;
-
-@Immutable
-@NotNullByDefault
-public class MailboxUpdateWithMailbox extends MailboxUpdate {
-
-	private final MailboxProperties properties;
-
-	public MailboxUpdateWithMailbox(List<MailboxVersion> clientSupports,
-			MailboxProperties properties) {
-		super(clientSupports, true);
-		if (properties.isOwner()) throw new IllegalArgumentException();
-		this.properties = properties;
-	}
-
-	public MailboxUpdateWithMailbox(MailboxUpdateWithMailbox o,
-			List<MailboxVersion> newClientSupports) {
-		this(newClientSupports, o.getMailboxProperties());
-	}
-
-	public MailboxProperties getMailboxProperties() {
-		return properties;
-	}
-}

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

@@ -1,8 +1,6 @@
-package org.briarproject.bramble.api.mailbox.event;
+package org.briarproject.bramble.api.mailbox;
 
 import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.mailbox.MailboxSettingsManager;
-import org.briarproject.bramble.api.mailbox.MailboxStatus;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import javax.annotation.concurrent.Immutable;

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

@@ -0,0 +1,36 @@
+package org.briarproject.bramble.api.mailbox;
+
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * An event that is broadcast when {@link MailboxPropertiesUpdate} are received
+ * from a contact.
+ */
+@Immutable
+@NotNullByDefault
+public class RemoteMailboxPropertiesUpdateEvent extends Event {
+
+	private final ContactId contactId;
+	@Nullable
+	private final MailboxPropertiesUpdate mailboxPropertiesUpdate;
+
+	public RemoteMailboxPropertiesUpdateEvent(ContactId contactId,
+			@Nullable MailboxPropertiesUpdate mailboxPropertiesUpdate) {
+		this.contactId = contactId;
+		this.mailboxPropertiesUpdate = mailboxPropertiesUpdate;
+	}
+
+	public ContactId getContact() {
+		return contactId;
+	}
+
+	@Nullable
+	public MailboxPropertiesUpdate getMailboxPropertiesUpdate() {
+		return mailboxPropertiesUpdate;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/event/MailboxProblemEvent.java

@@ -1,19 +0,0 @@
-package org.briarproject.bramble.api.mailbox.event;
-
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.mailbox.MailboxSettingsManager;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.Immutable;
-
-/**
- * An event that is broadcast by {@link MailboxSettingsManager} when
- * recording a connection failure for own Mailbox
- * that has persistent for long enough for the mailbox owner to become active
- * and fix the problem with the mailbox.
- */
-@Immutable
-@NotNullByDefault
-public class MailboxProblemEvent extends Event {
-
-}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/event/RemoteMailboxUpdateEvent.java

@@ -1,34 +0,0 @@
-package org.briarproject.bramble.api.mailbox.event;
-
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.mailbox.MailboxUpdate;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.Immutable;
-
-/**
- * An event that is broadcast when {@link MailboxUpdate} are received
- * from a contact.
- */
-@Immutable
-@NotNullByDefault
-public class RemoteMailboxUpdateEvent extends Event {
-
-	private final ContactId contactId;
-	private final MailboxUpdate mailboxUpdate;
-
-	public RemoteMailboxUpdateEvent(ContactId contactId,
-			MailboxUpdate mailboxUpdate) {
-		this.contactId = contactId;
-		this.mailboxUpdate = mailboxUpdate;
-	}
-
-	public ContactId getContact() {
-		return contactId;
-	}
-
-	public MailboxUpdate getMailboxUpdate() {
-		return mailboxUpdate;
-	}
-}

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/TorConstants.java

@@ -1,7 +1,5 @@
 package org.briarproject.bramble.api.plugin;
 
-import static java.util.concurrent.TimeUnit.SECONDS;
-
 public interface TorConstants {
 
 	TransportId ID = new TransportId("org.briarproject.bramble.tor");
@@ -12,9 +10,8 @@ public interface TorConstants {
 	int DEFAULT_SOCKS_PORT = 59050;
 	int DEFAULT_CONTROL_PORT = 59051;
 
-	int CONNECT_TO_PROXY_TIMEOUT = (int) SECONDS.toMillis(5);
-	int EXTRA_CONNECT_TIMEOUT = (int) SECONDS.toMillis(120);
-	int EXTRA_SOCKET_TIMEOUT = (int) SECONDS.toMillis(30);
+	int CONNECT_TO_PROXY_TIMEOUT = 5000; // Milliseconds
+	int EXTRA_SOCKET_TIMEOUT = 30000; // Milliseconds
 
 	// Local settings (not shared with contacts)
 	String PREF_TOR_NETWORK = "network2";

bramble-api/src/main/java/org/briarproject/bramble/api/record/RecordWriter.java

@@ -12,6 +12,4 @@ public interface RecordWriter {
 	void flush() throws IOException;
 
 	void close() throws IOException;
-
-	long getBytesWritten();
 }

bramble-api/src/main/java/org/briarproject/bramble/api/sync/OutgoingSessionRecord.java

@@ -1,37 +0,0 @@
-package org.briarproject.bramble.api.sync;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import java.util.Collection;
-import java.util.concurrent.CopyOnWriteArrayList;
-
-import javax.annotation.concurrent.ThreadSafe;
-
-/**
- * A container for holding the IDs of messages sent and acked during an
- * outgoing {@link SyncSession}, so they can be recorded in the DB as sent
- * or acked at some later time.
- */
-@ThreadSafe
-@NotNullByDefault
-public class OutgoingSessionRecord {
-
-	private final Collection<MessageId> ackedIds = new CopyOnWriteArrayList<>();
-	private final Collection<MessageId> sentIds = new CopyOnWriteArrayList<>();
-
-	public void onAckSent(Collection<MessageId> acked) {
-		ackedIds.addAll(acked);
-	}
-
-	public void onMessageSent(MessageId sent) {
-		sentIds.add(sent);
-	}
-
-	public Collection<MessageId> getAckedIds() {
-		return ackedIds;
-	}
-
-	public Collection<MessageId> getSentIds() {
-		return sentIds;
-	}
-}

bramble-api/src/main/java/org/briarproject/bramble/api/sync/SyncRecordWriter.java

@@ -20,6 +20,4 @@ public interface SyncRecordWriter {
 	void writePriority(Priority p) throws IOException;
 
 	void flush() throws IOException;
-
-	long getBytesWritten();
 }

bramble-api/src/main/java/org/briarproject/bramble/api/sync/SyncSessionFactory.java

@@ -12,30 +12,12 @@ import javax.annotation.Nullable;
 @NotNullByDefault
 public interface SyncSessionFactory {
 
-	/**
-	 * Creates a session for receiving data from a contact.
-	 */
 	SyncSession createIncomingSession(ContactId c, InputStream in,
 			PriorityHandler handler);
 
-	/**
-	 * Creates a session for sending data to a contact over a simplex transport.
-	 *
-	 * @param eager True if messages should be sent eagerly, ie regardless of
-	 * whether they're due for retransmission.
-	 */
 	SyncSession createSimplexOutgoingSession(ContactId c, TransportId t,
 			long maxLatency, boolean eager, StreamWriter streamWriter);
 
-	/**
-	 * Creates a session for sending data to a contact via a mailbox. The IDs
-	 * of any messages sent or acked will be added to the given
-	 * {@link OutgoingSessionRecord}.
-	 */
-	SyncSession createSimplexOutgoingSession(ContactId c, TransportId t,
-			long maxLatency, StreamWriter streamWriter,
-			OutgoingSessionRecord sessionRecord);
-
 	SyncSession createDuplexOutgoingSession(ContactId c, TransportId t,
 			long maxLatency, int maxIdleTime, StreamWriter streamWriter,
 			@Nullable Priority priority);

bramble-api/src/main/java/org/briarproject/bramble/api/sync/event/GroupVisibilityUpdatedEvent.java

@@ -3,7 +3,6 @@ package org.briarproject.bramble.api.sync.event;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.Group.Visibility;
 
 import java.util.Collection;
 
@@ -16,19 +15,12 @@ import javax.annotation.concurrent.Immutable;
 @NotNullByDefault
 public class GroupVisibilityUpdatedEvent extends Event {
 
-	private final Visibility visibility;
 	private final Collection<ContactId> affected;
 
-	public GroupVisibilityUpdatedEvent(Visibility visibility,
-			Collection<ContactId> affected) {
-		this.visibility = visibility;
+	public GroupVisibilityUpdatedEvent(Collection<ContactId> affected) {
 		this.affected = affected;
 	}
 
-	public Visibility getVisibility() {
-		return visibility;
-	}
-
 	/**
 	 * Returns the contacts affected by the update.
 	 */

bramble-api/src/main/java/org/briarproject/bramble/api/system/TaskScheduler.java

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.api.system;
 
-import org.briarproject.bramble.api.Cancellable;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import java.util.concurrent.Executor;
@@ -17,8 +16,6 @@ public interface TaskScheduler {
 	 * <p>
 	 * If the platform supports wake locks, a wake lock will be held while
 	 * submitting and running the task.
-	 *
-	 * @return A {@link Cancellable} for cancelling the task.
 	 */
 	Cancellable schedule(Runnable task, Executor executor, long delay,
 			TimeUnit unit);
@@ -30,11 +27,17 @@ public interface TaskScheduler {
 	 * <p>
 	 * If the platform supports wake locks, a wake lock will be held while
 	 * submitting and running the task.
-	 *
-	 * @return A {@link Cancellable} for cancelling all future executions of
-	 * the task.
 	 */
 	Cancellable scheduleWithFixedDelay(Runnable task, Executor executor,
 			long delay, long interval, TimeUnit unit);
 
+	interface Cancellable {
+
+		/**
+		 * Cancels the task if it has not already started running. If the task
+		 * is {@link #scheduleWithFixedDelay(Runnable, Executor, long, long, TimeUnit) periodic},
+		 * all future executions of the task are cancelled.
+		 */
+		void cancel();
+	}
 }

bramble-api/src/main/java/org/briarproject/bramble/util/IoUtils.java

@@ -40,7 +40,7 @@ public class IoUtils {
 		}
 	}
 
-	public static void delete(File f) {
+	private static void delete(File f) {
 		if (!f.delete() && LOG.isLoggable(WARNING))
 			LOG.warning("Could not delete " + f.getAbsolutePath());
 	}

bramble-api/src/main/java/org/briarproject/bramble/util/StringUtils.java

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.util;
 
-import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import java.io.UnsupportedEncodingException;
@@ -96,10 +95,10 @@ public class StringUtils {
 	/**
 	 * Converts the given hex string to a byte array.
 	 */
-	public static byte[] fromHexString(String hex) throws FormatException {
+	public static byte[] fromHexString(String hex) {
 		int len = hex.length();
 		if (len % 2 != 0)
-			throw new FormatException();
+			throw new IllegalArgumentException("Not a hex string");
 		byte[] bytes = new byte[len / 2];
 		for (int i = 0, j = 0; i < len; i += 2, j++) {
 			int high = hexDigitToInt(hex.charAt(i));
@@ -109,11 +108,11 @@ public class StringUtils {
 		return bytes;
 	}
 
-	private static int hexDigitToInt(char c) throws FormatException {
+	private static int hexDigitToInt(char c) {
 		if (c >= '0' && c <= '9') return c - '0';
 		if (c >= 'A' && c <= 'F') return c - 'A' + 10;
 		if (c >= 'a' && c <= 'f') return c - 'a' + 10;
-		throw new FormatException();
+		throw new IllegalArgumentException("Not a hex digit: " + c);
 	}
 
 	public static String trim(String s) {
@@ -131,13 +130,13 @@ public class StringUtils {
 		return MAC.matcher(mac).matches();
 	}
 
-	public static byte[] macToBytes(String mac) throws FormatException {
-		if (!MAC.matcher(mac).matches()) throw new FormatException();
+	public static byte[] macToBytes(String mac) {
+		if (!MAC.matcher(mac).matches()) throw new IllegalArgumentException();
 		return fromHexString(mac.replaceAll(":", ""));
 	}
 
-	public static String macToString(byte[] mac) throws FormatException {
-		if (mac.length != 6) throw new FormatException();
+	public static String macToString(byte[] mac) {
+		if (mac.length != 6) throw new IllegalArgumentException();
 		StringBuilder s = new StringBuilder();
 		for (byte b : mac) {
 			if (s.length() > 0) s.append(':');

bramble-api/src/test/java/org/briarproject/bramble/api/mailbox/MailboxHelperTest.java

@@ -1,44 +0,0 @@
-package org.briarproject.bramble.api.mailbox;
-
-import org.junit.Test;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Random;
-
-import static org.briarproject.bramble.api.mailbox.MailboxConstants.API_CLIENT_TOO_OLD;
-import static org.briarproject.bramble.api.mailbox.MailboxConstants.API_SERVER_TOO_OLD;
-import static org.briarproject.bramble.api.mailbox.MailboxHelper.getHighestCommonMajorVersion;
-import static org.junit.Assert.assertEquals;
-
-public class MailboxHelperTest {
-
-	private final Random random = new Random();
-
-	@Test
-	public void testGetHighestCommonMajorVersion() {
-		assertEquals(2, getHighestCommonMajorVersion(v(2), v(2)));
-		assertEquals(2, getHighestCommonMajorVersion(v(1, 2), v(2, 3, 4)));
-		assertEquals(2, getHighestCommonMajorVersion(v(2, 3, 4), v(2)));
-		assertEquals(2, getHighestCommonMajorVersion(v(2), v(2, 3, 4)));
-
-		assertEquals(API_CLIENT_TOO_OLD,
-				getHighestCommonMajorVersion(v(2), v(3, 4)));
-		assertEquals(API_CLIENT_TOO_OLD,
-				getHighestCommonMajorVersion(v(2), v(1, 3)));
-		assertEquals(API_SERVER_TOO_OLD,
-				getHighestCommonMajorVersion(v(3, 4, 5), v(2)));
-		assertEquals(API_SERVER_TOO_OLD,
-				getHighestCommonMajorVersion(v(1, 3), v(2)));
-	}
-
-	private List<MailboxVersion> v(int... ints) {
-		List<MailboxVersion> versions = new ArrayList<>(ints.length);
-		for (int v : ints) {
-			// minor versions should not matter
-			versions.add(new MailboxVersion(v, random.nextInt(42)));
-		}
-		return versions;
-	}
-
-}

bramble-api/src/test/java/org/briarproject/bramble/test/TestUtils.java

@@ -20,12 +20,8 @@ import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorId;
 import org.briarproject.bramble.api.identity.Identity;
 import org.briarproject.bramble.api.identity.LocalAuthor;
-import org.briarproject.bramble.api.mailbox.MailboxAuthToken;
-import org.briarproject.bramble.api.mailbox.MailboxFolderId;
 import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.mailbox.MailboxUpdate;
-import org.briarproject.bramble.api.mailbox.MailboxUpdateWithMailbox;
-import org.briarproject.bramble.api.mailbox.MailboxVersion;
+import org.briarproject.bramble.api.mailbox.MailboxPropertiesUpdate;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.sync.ClientId;
@@ -40,7 +36,6 @@ import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
-import java.security.NoSuchAlgorithmException;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
@@ -51,7 +46,6 @@ import java.util.Random;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import javax.annotation.Nullable;
-import javax.crypto.Cipher;
 
 import static java.util.Arrays.asList;
 import static org.briarproject.bramble.api.crypto.CryptoConstants.MAX_AGREEMENT_PUBLIC_KEY_BYTES;
@@ -228,19 +222,6 @@ public class TestUtils {
 				getAgreementPublicKey(), verified);
 	}
 
-	public static MailboxProperties getMailboxProperties(boolean owner,
-			List<MailboxVersion> serverSupports) {
-		String onion = getRandomString(56);
-		MailboxAuthToken authToken = new MailboxAuthToken(getRandomId());
-		if (owner) {
-			return new MailboxProperties(onion, authToken, serverSupports);
-		}
-		MailboxFolderId inboxId = new MailboxFolderId(getRandomId());
-		MailboxFolderId outboxId = new MailboxFolderId(getRandomId());
-		return new MailboxProperties(onion, authToken, serverSupports,
-				inboxId, outboxId);
-	}
-
 	public static void writeBytes(File file, byte[] bytes)
 			throws IOException {
 		FileOutputStream outputStream = new FileOutputStream(file);
@@ -293,30 +274,26 @@ public class TestUtils {
 		return Math.sqrt(getVariance(samples));
 	}
 
-	public static boolean isOptionalTestEnabled(Class<?> testClass) {
+	public static boolean isOptionalTestEnabled(Class testClass) {
 		String optionalTests = System.getenv("OPTIONAL_TESTS");
 		return optionalTests != null &&
 				asList(optionalTests.split(",")).contains(testClass.getName());
 	}
 
-	public static boolean mailboxUpdateEqual(@Nullable MailboxUpdate a,
-			@Nullable MailboxUpdate b) {
+	public static boolean mailboxPropertiesUpdateEqual(
+			@Nullable MailboxPropertiesUpdate a,
+			@Nullable MailboxPropertiesUpdate b) {
 		if (a == null || b == null) {
 			return a == b;
 		}
-		if (!a.hasMailbox() && !b.hasMailbox()) {
-			return a.getClientSupports().equals(b.getClientSupports());
-		} else if (a.hasMailbox() && b.hasMailbox()) {
-			MailboxUpdateWithMailbox am = (MailboxUpdateWithMailbox) a;
-			MailboxUpdateWithMailbox bm = (MailboxUpdateWithMailbox) b;
-			return am.getClientSupports().equals(bm.getClientSupports()) &&
-					mailboxPropertiesEqual(am.getMailboxProperties(),
-							bm.getMailboxProperties());
-		}
-		return false;
+		return a.getOnion().equals(b.getOnion()) &&
+				a.getAuthToken().equals(b.getAuthToken()) &&
+				a.getInboxId().equals(b.getInboxId()) &&
+				a.getOutboxId().equals(b.getOutboxId());
 	}
 
-	public static boolean mailboxPropertiesEqual(@Nullable MailboxProperties a,
+	public static boolean mailboxPropertiesEqual(
+			@Nullable MailboxProperties a,
 			@Nullable MailboxProperties b) {
 		if (a == null || b == null) {
 			return a == b;
@@ -337,13 +314,4 @@ public class TestUtils {
 		}
 		return false;
 	}
-
-	public static boolean isCryptoStrengthUnlimited() {
-		try {
-			return Cipher.getMaxAllowedKeyLength("AES/CBC/PKCS5Padding")
-					== Integer.MAX_VALUE;
-		} catch (NoSuchAlgorithmException e) {
-			throw new AssertionError();
-		}
-	}
 }

bramble-core/build.gradle

@@ -16,7 +16,7 @@ dependencies {
 	implementation 'org.bitlet:weupnp:0.1.4'
 	implementation 'net.i2p.crypto:eddsa:0.2.0'
 	implementation 'org.whispersystems:curve25519-java:0.5.0'
-	implementation 'org.briarproject:jtorctl:0.4'
+	implementation 'org.briarproject:jtorctl:0.3'
 
 	//noinspection GradleDependency
 	implementation "com.squareup.okhttp3:okhttp:$okhttp_version"

bramble-core/src/main/java/org/briarproject/bramble/account/AccountManagerImpl.java

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.account;
 
-import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.account.AccountManager;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.DecryptionException;
@@ -210,13 +209,7 @@ class AccountManagerImpl implements AccountManager {
 			LOG.warning("Failed to load encrypted database key");
 			throw new DecryptionException(INVALID_CIPHERTEXT);
 		}
-		byte[] ciphertext;
-		try {
-			ciphertext = fromHexString(hex);
-		} catch (FormatException e) {
-			LOG.warning("Encrypted database key has invalid format");
-			throw new DecryptionException(INVALID_CIPHERTEXT);
-		}
+		byte[] ciphertext = fromHexString(hex);
 		KeyStrengthener keyStrengthener = databaseConfig.getKeyStrengthener();
 		byte[] plaintext = crypto.decryptWithPassword(ciphertext, password,
 				keyStrengthener);

bramble-core/src/main/java/org/briarproject/bramble/client/ClientHelperImpl.java

@@ -25,10 +25,7 @@ import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorFactory;
 import org.briarproject.bramble.api.mailbox.MailboxAuthToken;
 import org.briarproject.bramble.api.mailbox.MailboxFolderId;
-import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.mailbox.MailboxUpdate;
-import org.briarproject.bramble.api.mailbox.MailboxUpdateWithMailbox;
-import org.briarproject.bramble.api.mailbox.MailboxVersion;
+import org.briarproject.bramble.api.mailbox.MailboxPropertiesUpdate;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.properties.TransportProperties;
@@ -42,13 +39,12 @@ import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.security.GeneralSecurityException;
-import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
-import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 
+import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
@@ -56,12 +52,12 @@ import static org.briarproject.bramble.api.client.ContactGroupConstants.GROUP_KE
 import static org.briarproject.bramble.api.identity.Author.FORMAT_VERSION;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_PUBLIC_KEY_LENGTH;
-import static org.briarproject.bramble.api.mailbox.MailboxUpdateManager.PROP_COUNT;
-import static org.briarproject.bramble.api.mailbox.MailboxUpdateManager.PROP_KEY_AUTHTOKEN;
-import static org.briarproject.bramble.api.mailbox.MailboxUpdateManager.PROP_KEY_INBOXID;
-import static org.briarproject.bramble.api.mailbox.MailboxUpdateManager.PROP_KEY_ONION;
-import static org.briarproject.bramble.api.mailbox.MailboxUpdateManager.PROP_KEY_OUTBOXID;
-import static org.briarproject.bramble.api.mailbox.MailboxUpdateManager.PROP_ONION_LENGTH;
+import static org.briarproject.bramble.api.mailbox.MailboxPropertyManager.PROP_COUNT;
+import static org.briarproject.bramble.api.mailbox.MailboxPropertyManager.PROP_KEY_AUTHTOKEN;
+import static org.briarproject.bramble.api.mailbox.MailboxPropertyManager.PROP_KEY_INBOXID;
+import static org.briarproject.bramble.api.mailbox.MailboxPropertyManager.PROP_KEY_ONION;
+import static org.briarproject.bramble.api.mailbox.MailboxPropertyManager.PROP_KEY_OUTBOXID;
+import static org.briarproject.bramble.api.mailbox.MailboxPropertyManager.PROP_ONION_LENGTH;
 import static org.briarproject.bramble.api.properties.TransportPropertyConstants.MAX_PROPERTIES_PER_TRANSPORT;
 import static org.briarproject.bramble.api.properties.TransportPropertyConstants.MAX_PROPERTY_LENGTH;
 import static org.briarproject.bramble.util.ValidationUtils.checkLength;
@@ -416,28 +412,11 @@ class ClientHelperImpl implements ClientHelper {
 	}
 
 	@Override
-	public MailboxUpdate parseAndValidateMailboxUpdate(BdfList clientSupports,
-			BdfList serverSupports, BdfDictionary properties)
-			throws FormatException {
-		List<MailboxVersion> clientSupportsList =
-				parseMailboxVersionList(clientSupports);
-		List<MailboxVersion> serverSupportsList =
-				parseMailboxVersionList(serverSupports);
-
-		// We must always learn what Mailbox API version(s) the client supports
-		if (clientSupports.isEmpty()) {
-			throw new FormatException();
-		}
+	@Nullable
+	public MailboxPropertiesUpdate parseAndValidateMailboxPropertiesUpdate(
+			BdfDictionary properties) throws FormatException {
 		if (properties.isEmpty()) {
-			// No mailbox -- cannot claim to support any API versions!
-			if (!serverSupports.isEmpty()) {
-				throw new FormatException();
-			}
-			return new MailboxUpdate(clientSupportsList);
-		}
-		// Mailbox must be accompanied by the Mailbox API version(s) it supports
-		if (serverSupports.isEmpty()) {
-			throw new FormatException();
+			return null;
 		}
 		// Accepting more props than we need, for forward compatibility
 		if (properties.size() < PROP_COUNT) {
@@ -456,25 +435,9 @@ class ClientHelperImpl implements ClientHelper {
 		checkLength(inboxId, UniqueId.LENGTH);
 		byte[] outboxId = properties.getRaw(PROP_KEY_OUTBOXID);
 		checkLength(outboxId, UniqueId.LENGTH);
-		MailboxProperties props = new MailboxProperties(onion,
-				new MailboxAuthToken(authToken), serverSupportsList,
-				new MailboxFolderId(inboxId), new MailboxFolderId(outboxId));
-		return new MailboxUpdateWithMailbox(clientSupportsList, props);
-	}
-
-	@Override
-	public List<MailboxVersion> parseMailboxVersionList(BdfList bdfList)
-			throws FormatException {
-		List<MailboxVersion> list = new ArrayList<>();
-		for (int i = 0; i < bdfList.size(); i++) {
-			BdfList element = bdfList.getList(i);
-			if (element.size() != 2) {
-				throw new FormatException();
-			}
-			list.add(new MailboxVersion(element.getLong(0).intValue(),
-					element.getLong(1).intValue()));
-		}
-		return list;
+		return new MailboxPropertiesUpdate(onion,
+				new MailboxAuthToken(authToken), new MailboxFolderId(inboxId),
+				new MailboxFolderId(outboxId));
 	}
 
 	@Override

bramble-core/src/main/java/org/briarproject/bramble/connection/Connection.java

@@ -54,7 +54,7 @@ abstract class Connection {
 		}
 	}
 
-	byte[] readTag(InputStream in) throws IOException {
+	private byte[] readTag(InputStream in) throws IOException {
 		byte[] tag = new byte[TAG_LENGTH];
 		read(in, tag);
 		return tag;

bramble-core/src/main/java/org/briarproject/bramble/connection/ConnectionManagerImpl.java

@@ -13,7 +13,6 @@ import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 import org.briarproject.bramble.api.properties.TransportPropertyManager;
-import org.briarproject.bramble.api.sync.OutgoingSessionRecord;
 import org.briarproject.bramble.api.sync.SyncSessionFactory;
 import org.briarproject.bramble.api.transport.KeyManager;
 import org.briarproject.bramble.api.transport.StreamReaderFactory;
@@ -68,15 +67,7 @@ class ConnectionManagerImpl implements ConnectionManager {
 			TransportConnectionReader r) {
 		ioExecutor.execute(new IncomingSimplexSyncConnection(keyManager,
 				connectionRegistry, streamReaderFactory, streamWriterFactory,
-				syncSessionFactory, transportPropertyManager, t, r, null));
-	}
-
-	@Override
-	public void manageIncomingConnection(TransportId t,
-			TransportConnectionReader r, TagController c) {
-		ioExecutor.execute(new IncomingSimplexSyncConnection(keyManager,
-				connectionRegistry, streamReaderFactory, streamWriterFactory,
-				syncSessionFactory, transportPropertyManager, t, r, c));
+				syncSessionFactory, transportPropertyManager, t, r));
 	}
 
 	@Override
@@ -101,16 +92,7 @@ class ConnectionManagerImpl implements ConnectionManager {
 			TransportConnectionWriter w) {
 		ioExecutor.execute(new OutgoingSimplexSyncConnection(keyManager,
 				connectionRegistry, streamReaderFactory, streamWriterFactory,
-				syncSessionFactory, transportPropertyManager, c, t, w, null));
-	}
-
-	@Override
-	public void manageOutgoingConnection(ContactId c, TransportId t,
-			TransportConnectionWriter w, OutgoingSessionRecord sessionRecord) {
-		ioExecutor.execute(new OutgoingSimplexSyncConnection(keyManager,
-				connectionRegistry, streamReaderFactory, streamWriterFactory,
-				syncSessionFactory, transportPropertyManager, c, t, w,
-				sessionRecord));
+				syncSessionFactory, transportPropertyManager, c, t, w));
 	}
 
 	@Override

bramble-core/src/main/java/org/briarproject/bramble/connection/IncomingSimplexSyncConnection.java

@@ -1,9 +1,7 @@
 package org.briarproject.bramble.connection;
 
-import org.briarproject.bramble.api.connection.ConnectionManager.TagController;
 import org.briarproject.bramble.api.connection.ConnectionRegistry;
 import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportConnectionReader;
 import org.briarproject.bramble.api.plugin.TransportId;
@@ -17,8 +15,6 @@ import org.briarproject.bramble.api.transport.StreamWriterFactory;
 
 import java.io.IOException;
 
-import javax.annotation.Nullable;
-
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.LogUtils.logException;
 
@@ -27,8 +23,6 @@ class IncomingSimplexSyncConnection extends SyncConnection implements Runnable {
 
 	private final TransportId transportId;
 	private final TransportConnectionReader reader;
-	@Nullable
-	private final TagController tagController;
 
 	IncomingSimplexSyncConnection(KeyManager keyManager,
 			ConnectionRegistry connectionRegistry,
@@ -36,50 +30,33 @@ class IncomingSimplexSyncConnection extends SyncConnection implements Runnable {
 			StreamWriterFactory streamWriterFactory,
 			SyncSessionFactory syncSessionFactory,
 			TransportPropertyManager transportPropertyManager,
-			TransportId transportId,
-			TransportConnectionReader reader,
-			@Nullable TagController tagController) {
+			TransportId transportId, TransportConnectionReader reader) {
 		super(keyManager, connectionRegistry, streamReaderFactory,
 				streamWriterFactory, syncSessionFactory,
 				transportPropertyManager);
 		this.transportId = transportId;
 		this.reader = reader;
-		this.tagController = tagController;
 	}
 
 	@Override
 	public void run() {
 		// Read and recognise the tag
-		byte[] tag;
-		StreamContext ctx;
-		try {
-			tag = readTag(reader.getInputStream());
-			// If we have a tag controller, defer marking the tag as recognised
-			if (tagController == null) {
-				ctx = keyManager.getStreamContext(transportId, tag);
-			} else {
-				ctx = keyManager.getStreamContextOnly(transportId, tag);
-			}
-		} catch (IOException | DbException e) {
-			logException(LOG, WARNING, e);
-			onError();
-			return;
-		}
+		StreamContext ctx = recogniseTag(reader, transportId);
 		if (ctx == null) {
 			LOG.info("Unrecognised tag");
-			onError();
+			onError(false);
 			return;
 		}
 		ContactId contactId = ctx.getContactId();
 		if (contactId == null) {
 			LOG.warning("Received rendezvous stream, expected contact");
-			onError(tag);
+			onError(true);
 			return;
 		}
 		if (ctx.isHandshakeMode()) {
 			// TODO: Support handshake mode for contacts
 			LOG.warning("Received handshake tag, expected rotation mode");
-			onError(tag);
+			onError(true);
 			return;
 		}
 		try {
@@ -88,33 +65,15 @@ class IncomingSimplexSyncConnection extends SyncConnection implements Runnable {
 					LOG.info("Ignoring priority for simplex connection");
 			// Create and run the incoming session
 			createIncomingSession(ctx, reader, handler).run();
-			// Success
-			markTagAsRecognisedIfRequired(false, tag);
 			reader.dispose(false, true);
 		} catch (IOException e) {
 			logException(LOG, WARNING, e);
-			onError(tag);
+			onError(true);
 		}
 	}
 
-	private void onError() {
-		disposeOnError(reader, false);
-	}
-
-	private void onError(byte[] tag) {
-		markTagAsRecognisedIfRequired(true, tag);
-		disposeOnError(reader, true);
-	}
-
-	private void markTagAsRecognisedIfRequired(boolean exception, byte[] tag) {
-		if (tagController != null &&
-				tagController.shouldMarkTagAsRecognised(exception)) {
-			try {
-				keyManager.markTagAsRecognised(transportId, tag);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
-		}
+	private void onError(boolean recognised) {
+		disposeOnError(reader, recognised);
 	}
 }
 

bramble-core/src/main/java/org/briarproject/bramble/connection/OutgoingSimplexSyncConnection.java

@@ -6,7 +6,6 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.properties.TransportPropertyManager;
-import org.briarproject.bramble.api.sync.OutgoingSessionRecord;
 import org.briarproject.bramble.api.sync.SyncSession;
 import org.briarproject.bramble.api.sync.SyncSessionFactory;
 import org.briarproject.bramble.api.transport.KeyManager;
@@ -17,8 +16,6 @@ import org.briarproject.bramble.api.transport.StreamWriterFactory;
 
 import java.io.IOException;
 
-import javax.annotation.Nullable;
-
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
 import static org.briarproject.bramble.util.LogUtils.logException;
@@ -29,8 +26,6 @@ class OutgoingSimplexSyncConnection extends SyncConnection implements Runnable {
 	private final ContactId contactId;
 	private final TransportId transportId;
 	private final TransportConnectionWriter writer;
-	@Nullable
-	private final OutgoingSessionRecord sessionRecord;
 
 	OutgoingSimplexSyncConnection(KeyManager keyManager,
 			ConnectionRegistry connectionRegistry,
@@ -39,15 +34,13 @@ class OutgoingSimplexSyncConnection extends SyncConnection implements Runnable {
 			SyncSessionFactory syncSessionFactory,
 			TransportPropertyManager transportPropertyManager,
 			ContactId contactId, TransportId transportId,
-			TransportConnectionWriter writer,
-			@Nullable OutgoingSessionRecord sessionRecord) {
+			TransportConnectionWriter writer) {
 		super(keyManager, connectionRegistry, streamReaderFactory,
 				streamWriterFactory, syncSessionFactory,
 				transportPropertyManager);
 		this.contactId = contactId;
 		this.transportId = transportId;
 		this.writer = writer;
-		this.sessionRecord = sessionRecord;
 	}
 
 	@Override
@@ -78,16 +71,10 @@ class OutgoingSimplexSyncConnection extends SyncConnection implements Runnable {
 		StreamWriter streamWriter = streamWriterFactory.createStreamWriter(
 				w.getOutputStream(), ctx);
 		ContactId c = requireNonNull(ctx.getContactId());
-		if (sessionRecord == null) {
-			// Use eager retransmission if the transport is lossy and cheap
-			return syncSessionFactory.createSimplexOutgoingSession(c,
-					ctx.getTransportId(), w.getMaxLatency(),
-					w.isLossyAndCheap(), streamWriter);
-		} else {
-			return syncSessionFactory.createSimplexOutgoingSession(c,
-					ctx.getTransportId(), w.getMaxLatency(), streamWriter,
-					sessionRecord);
-		}
+		// Use eager retransmission if the transport is lossy and cheap
+		return syncSessionFactory.createSimplexOutgoingSession(c,
+				ctx.getTransportId(), w.getMaxLatency(), w.isLossyAndCheap(),
+				streamWriter);
 	}
 }
 

bramble-core/src/main/java/org/briarproject/bramble/db/Database.java

@@ -163,11 +163,16 @@ interface Database<T> {
 			throws DbException;
 
 	/**
-	 * Returns true if there are any acks to send to the given contact.
+	 * Returns true if there are any acks or messages to send to the given
+	 * contact over a transport with the given maximum latency.
 	 * <p/>
 	 * Read-only.
+	 *
+	 * @param eager True if messages that are not yet due for retransmission
+	 * should be included
 	 */
-	boolean containsAcksToSend(T txn, ContactId c) throws DbException;
+	boolean containsAnythingToSend(T txn, ContactId c, long maxLatency,
+			boolean eager) throws DbException;
 
 	/**
 	 * Returns true if the database contains the given contact for the given
@@ -207,18 +212,6 @@ interface Database<T> {
 	 */
 	boolean containsMessage(T txn, MessageId m) throws DbException;
 
-	/**
-	 * Returns true if there are any messages to send to the given
-	 * contact over a transport with the given maximum latency.
-	 * <p/>
-	 * Read-only.
-	 *
-	 * @param eager True if messages that are not yet due for retransmission
-	 * should be included
-	 */
-	boolean containsMessagesToSend(T txn, ContactId c, long maxLatency,
-			boolean eager) throws DbException;
-
 	/**
 	 * Returns true if the database contains the given pending contact.
 	 * <p/>
@@ -413,12 +406,6 @@ interface Database<T> {
 	Collection<MessageId> getMessageIds(T txn, GroupId g, Metadata query)
 			throws DbException;
 
-	/**
-	 * Returns the length of the given message in bytes, including the
-	 * message header.
-	 */
-	int getMessageLength(T txn, MessageId m) throws DbException;
-
 	/**
 	 * Returns the metadata for all delivered messages in the given group.
 	 * <p/>
@@ -509,8 +496,7 @@ interface Database<T> {
 
 	/**
 	 * Returns the IDs of some messages that are eligible to be sent to the
-	 * given contact. The total length of the messages including record headers
-	 * will be no more than the given capacity.
+	 * given contact, up to the given total length.
 	 * <p/>
 	 * Unlike {@link #getUnackedMessagesToSend(Object, ContactId)} this method
 	 * does not return messages that have already been sent unless they are
@@ -518,20 +504,20 @@ interface Database<T> {
 	 * <p/>
 	 * Read-only.
 	 */
-	Collection<MessageId> getMessagesToSend(T txn, ContactId c, long capacity,
+	Collection<MessageId> getMessagesToSend(T txn, ContactId c, int maxLength,
 			long maxLatency) throws DbException;
 
 	/**
 	 * Returns the IDs of all messages that are eligible to be sent to the
-	 * given contact.
+	 * given contact, together with their raw lengths.
 	 * <p/>
-	 * Unlike {@link #getMessagesToSend(Object, ContactId, long, long)} this
+	 * Unlike {@link #getMessagesToSend(Object, ContactId, int, long)} this
 	 * method may return messages that have already been sent and are not yet
 	 * due for retransmission.
 	 * <p/>
 	 * Read-only.
 	 */
-	Collection<MessageId> getUnackedMessagesToSend(T txn, ContactId c)
+	Map<MessageId, Integer> getUnackedMessagesToSend(T txn, ContactId c)
 			throws DbException;
 
 	/**
@@ -587,16 +573,13 @@ interface Database<T> {
 
 	/**
 	 * Returns the next time (in milliseconds since the Unix epoch) when a
-	 * message is due to be sent to the given contact over a transport with
-	 * the given latency.
-	 * <p>
-	 * The returned value may be zero if a message is due to be sent
-	 * immediately, or Long.MAX_VALUE if no messages are scheduled to be sent.
+	 * message is due to be sent to the given contact. The returned value may
+	 * be zero if a message is due to be sent immediately, or Long.MAX_VALUE
+	 * if no messages are scheduled to be sent.
 	 * <p/>
 	 * Read-only.
 	 */
-	long getNextSendTime(T txn, ContactId c, long maxLatency)
-			throws DbException;
+	long getNextSendTime(T txn, ContactId c) throws DbException;
 
 	/**
 	 * Returns the pending contact with the given ID.
@@ -615,14 +598,13 @@ interface Database<T> {
 
 	/**
 	 * Returns the IDs of some messages that are eligible to be sent to the
-	 * given contact and have been requested by the contact. The total length
-	 * of the messages including record headers will be no more than the given
-	 * capacity.
+	 * given contact and have been requested by the contact, up to the given
+	 * total length.
 	 * <p/>
 	 * Read-only.
 	 */
 	Collection<MessageId> getRequestedMessagesToSend(T txn, ContactId c,
-			long capacity, long maxLatency) throws DbException;
+			int maxLength, long maxLatency) throws DbException;
 
 	/**
 	 * Returns all settings in the given namespace.
@@ -880,4 +862,6 @@ interface Database<T> {
 	 * Stores the given transport keys, deleting any keys they have replaced.
 	 */
 	void updateTransportKeys(T txn, TransportKeySet ks) throws DbException;
+
+	void printStats(T txn) throws DbException;
 }

bramble-core/src/main/java/org/briarproject/bramble/db/DatabaseComponentImpl.java

@@ -75,6 +75,7 @@ import org.briarproject.bramble.api.transport.TransportKeys;
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.Executor;
@@ -86,7 +87,6 @@ import javax.annotation.Nullable;
 import javax.annotation.concurrent.ThreadSafe;
 import javax.inject.Inject;
 
-import static java.util.Collections.singletonList;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.sync.Group.Visibility.INVISIBLE;
@@ -342,12 +342,12 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	}
 
 	@Override
-	public boolean containsAcksToSend(Transaction transaction, ContactId c)
-			throws DbException {
+	public boolean containsAnythingToSend(Transaction transaction, ContactId c,
+			long maxLatency, boolean eager) throws DbException {
 		T txn = unbox(transaction);
 		if (!db.containsContact(txn, c))
 			throw new NoSuchContactException();
-		return db.containsAcksToSend(txn, c);
+		return db.containsAnythingToSend(txn, c, maxLatency, eager);
 	}
 
 	@Override
@@ -373,15 +373,6 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		return db.containsIdentity(txn, a);
 	}
 
-	@Override
-	public boolean containsMessagesToSend(Transaction transaction, ContactId c,
-			long maxLatency, boolean eager) throws DbException {
-		T txn = unbox(transaction);
-		if (!db.containsContact(txn, c))
-			throw new NoSuchContactException();
-		return db.containsMessagesToSend(txn, c, maxLatency, eager);
-	}
-
 	@Override
 	public boolean containsPendingContact(Transaction transaction,
 			PendingContactId p) throws DbException {
@@ -433,14 +424,13 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	@Nullable
 	@Override
 	public Collection<Message> generateBatch(Transaction transaction,
-			ContactId c, long capacity, long maxLatency) throws DbException {
+			ContactId c, int maxLength, long maxLatency) throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
 		if (!db.containsContact(txn, c))
 			throw new NoSuchContactException();
 		Collection<MessageId> ids =
-				db.getMessagesToSend(txn, c, capacity, maxLatency);
-		if (ids.isEmpty()) return null;
+				db.getMessagesToSend(txn, c, maxLength, maxLatency);
 		long totalLength = 0;
 		List<Message> messages = new ArrayList<>(ids.size());
 		for (MessageId m : ids) {
@@ -449,11 +439,38 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 			messages.add(message);
 			db.updateRetransmissionData(txn, c, m, maxLatency);
 		}
+		if (ids.isEmpty()) return null;
 		db.lowerRequestedFlag(txn, c, ids);
 		transaction.attach(new MessagesSentEvent(c, ids, totalLength));
 		return messages;
 	}
 
+	@Override
+	public Collection<Message> generateBatch(Transaction transaction,
+			ContactId c, Collection<MessageId> ids, long maxLatency)
+			throws DbException {
+		if (transaction.isReadOnly()) throw new IllegalArgumentException();
+		T txn = unbox(transaction);
+		if (!db.containsContact(txn, c))
+			throw new NoSuchContactException();
+		long totalLength = 0;
+		List<Message> messages = new ArrayList<>(ids.size());
+		List<MessageId> sentIds = new ArrayList<>(ids.size());
+		for (MessageId m : ids) {
+			if (db.containsVisibleMessage(txn, c, m)) {
+				Message message = db.getMessage(txn, m);
+				totalLength += message.getRawLength();
+				messages.add(message);
+				sentIds.add(m);
+				db.updateRetransmissionData(txn, c, m, maxLatency);
+			}
+		}
+		if (messages.isEmpty()) return messages;
+		db.lowerRequestedFlag(txn, c, sentIds);
+		transaction.attach(new MessagesSentEvent(c, sentIds, totalLength));
+		return messages;
+	}
+
 	@Nullable
 	@Override
 	public Offer generateOffer(Transaction transaction, ContactId c,
@@ -488,14 +505,13 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	@Nullable
 	@Override
 	public Collection<Message> generateRequestedBatch(Transaction transaction,
-			ContactId c, long capacity, long maxLatency) throws DbException {
+			ContactId c, int maxLength, long maxLatency) throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
 		if (!db.containsContact(txn, c))
 			throw new NoSuchContactException();
 		Collection<MessageId> ids =
-				db.getRequestedMessagesToSend(txn, c, capacity, maxLatency);
-		if (ids.isEmpty()) return null;
+				db.getRequestedMessagesToSend(txn, c, maxLength, maxLatency);
 		long totalLength = 0;
 		List<Message> messages = new ArrayList<>(ids.size());
 		for (MessageId m : ids) {
@@ -504,6 +520,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 			messages.add(message);
 			db.updateRetransmissionData(txn, c, m, maxLatency);
 		}
+		if (ids.isEmpty()) return null;
 		db.lowerRequestedFlag(txn, c, ids);
 		transaction.attach(new MessagesSentEvent(c, ids, totalLength));
 		return messages;
@@ -618,24 +635,6 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		return db.getMessageIds(txn, g, query);
 	}
 
-	@Override
-	public Collection<MessageId> getMessagesToAck(Transaction transaction,
-			ContactId c, int maxMessages) throws DbException {
-		T txn = unbox(transaction);
-		if (!db.containsContact(txn, c))
-			throw new NoSuchContactException();
-		return db.getMessagesToAck(txn, c, maxMessages);
-	}
-
-	@Override
-	public Collection<MessageId> getMessagesToSend(Transaction transaction,
-			ContactId c, long capacity, long maxLatency) throws DbException {
-		T txn = unbox(transaction);
-		if (!db.containsContact(txn, c))
-			throw new NoSuchContactException();
-		return db.getMessagesToSend(txn, c, capacity, maxLatency);
-	}
-
 	@Override
 	public Collection<MessageId> getMessagesToValidate(Transaction transaction)
 			throws DbException {
@@ -741,29 +740,10 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		return status;
 	}
 
-	@Nullable
 	@Override
-	public Message getMessageToSend(Transaction transaction, ContactId c,
-			MessageId m, long maxLatency, boolean markAsSent)
-			throws DbException {
-		if (transaction.isReadOnly()) throw new IllegalArgumentException();
-		T txn = unbox(transaction);
-		if (!db.containsContact(txn, c))
-			throw new NoSuchContactException();
-		if (!db.containsVisibleMessage(txn, c, m)) return null;
-		Message message = db.getMessage(txn, m);
-		if (markAsSent) {
-			db.updateRetransmissionData(txn, c, m, maxLatency);
-			db.lowerRequestedFlag(txn, c, singletonList(m));
-			transaction.attach(new MessagesSentEvent(c, singletonList(m),
-					message.getRawLength()));
-		}
-		return message;
-	}
-
-	@Override
-	public Collection<MessageId> getUnackedMessagesToSend(
-			Transaction transaction, ContactId c) throws DbException {
+	public Map<MessageId, Integer> getUnackedMessagesToSend(
+			Transaction transaction,
+			ContactId c) throws DbException {
 		T txn = unbox(transaction);
 		if (!db.containsContact(txn, c))
 			throw new NoSuchContactException();
@@ -814,10 +794,10 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	}
 
 	@Override
-	public long getNextSendTime(Transaction transaction, ContactId c,
-			long maxLatency) throws DbException {
+	public long getNextSendTime(Transaction transaction, ContactId c)
+			throws DbException {
 		T txn = unbox(transaction);
-		return db.getNextSendTime(txn, c, maxLatency);
+		return db.getNextSendTime(txn, c);
 	}
 
 	@Override
@@ -1025,8 +1005,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 				db.getGroupVisibility(txn, id).keySet();
 		db.removeGroup(txn, id);
 		transaction.attach(new GroupRemovedEvent(g));
-		transaction.attach(new GroupVisibilityUpdatedEvent(INVISIBLE,
-				affected));
+		transaction.attach(new GroupVisibilityUpdatedEvent(affected));
 	}
 
 	@Override
@@ -1090,20 +1069,6 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		db.removeTransportKeys(txn, t, k);
 	}
 
-	@Override
-	public void setAckSent(Transaction transaction, ContactId c,
-			Collection<MessageId> acked) throws DbException {
-		if (transaction.isReadOnly()) throw new IllegalArgumentException();
-		T txn = unbox(transaction);
-		if (!db.containsContact(txn, c))
-			throw new NoSuchContactException();
-		List<MessageId> visible = new ArrayList<>(acked.size());
-		for (MessageId m : acked) {
-			if (db.containsVisibleMessage(txn, c, m)) visible.add(m);
-		}
-		db.lowerAckFlag(txn, c, visible);
-	}
-
 	@Override
 	public void setCleanupTimerDuration(Transaction transaction, MessageId m,
 			long duration) throws DbException {
@@ -1150,8 +1115,8 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		if (old == INVISIBLE) db.addGroupVisibility(txn, c, g, v == SHARED);
 		else if (v == INVISIBLE) db.removeGroupVisibility(txn, c, g);
 		else db.setGroupVisibility(txn, c, g, v == SHARED);
-		List<ContactId> affected = singletonList(c);
-		transaction.attach(new GroupVisibilityUpdatedEvent(v, affected));
+		List<ContactId> affected = Collections.singletonList(c);
+		transaction.attach(new GroupVisibilityUpdatedEvent(affected));
 	}
 
 	@Override
@@ -1198,28 +1163,6 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		transaction.attach(new MessageStateChangedEvent(m, false, state));
 	}
 
-	@Override
-	public void setMessagesSent(Transaction transaction, ContactId c,
-			Collection<MessageId> sent, long maxLatency) throws DbException {
-		if (transaction.isReadOnly()) throw new IllegalArgumentException();
-		T txn = unbox(transaction);
-		if (!db.containsContact(txn, c))
-			throw new NoSuchContactException();
-		long totalLength = 0;
-		List<MessageId> visible = new ArrayList<>(sent.size());
-		for (MessageId m : sent) {
-			if (db.containsVisibleMessage(txn, c, m)) {
-				visible.add(m);
-				totalLength += db.getMessageLength(txn, m);
-				db.updateRetransmissionData(txn, c, m, maxLatency);
-			}
-		}
-		db.lowerRequestedFlag(txn, c, visible);
-		if (!visible.isEmpty()) {
-			transaction.attach(new MessagesSentEvent(c, visible, totalLength));
-		}
-	}
-
 	@Override
 	public void addMessageDependencies(Transaction transaction,
 			Message dependent, Collection<MessageId> dependencies)
@@ -1313,6 +1256,12 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		}
 	}
 
+	@Override
+	public void printStats(Transaction transaction) throws DbException {
+		T txn = unbox(transaction);
+		db.printStats(txn);
+	}
+
 	private class CommitActionVisitor implements Visitor {
 
 		@Override

bramble-core/src/main/java/org/briarproject/bramble/db/H2Database.java

@@ -13,8 +13,12 @@ import org.briarproject.bramble.util.StringUtils;
 import java.io.File;
 import java.sql.Connection;
 import java.sql.DriverManager;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Properties;
 import java.util.logging.Logger;
 
@@ -26,6 +30,7 @@ import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.db.JdbcUtils.tryToClose;
 import static org.briarproject.bramble.util.IoUtils.isNonEmptyDirectory;
+import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.logFileOrDir;
 
 /**
@@ -101,6 +106,73 @@ class H2Database extends JdbcDatabase {
 		}
 	}
 
+	@Override
+	public void printStats(Connection txn) throws DbException {
+		List<String> names = printNames(txn);
+		for (String table : names) {
+			tryPrintStats(txn, table);
+		}
+	}
+
+	private List<String> printNames(Connection txn) throws DbException {
+		List<String> names = new ArrayList<>();
+		PreparedStatement ps = null;
+		ResultSet rs = null;
+		try {
+			String sql =
+					"SELECT table_catalog, table_schema, table_name FROM INFORMATION_SCHEMA.TABLES";
+			ps = txn.prepareStatement(sql);
+			rs = ps.executeQuery();
+			while (rs.next()) {
+				String catalog = rs.getString(1);
+				String schema = rs.getString(2);
+				String name = rs.getString(3);
+				LOG.info(
+						String.format("Table %s %s %s", catalog, schema, name));
+				names.add(schema + "." + name);
+			}
+			rs.close();
+			ps.close();
+		} catch (SQLException e) {
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
+			throw new DbException(e);
+		}
+		return names;
+	}
+
+	private void tryPrintStats(Connection txn, String table) {
+		try {
+			printStats(txn, table);
+		} catch (DbException e) {
+			logException(LOG, WARNING, e);
+		}
+	}
+
+	private void printStats(Connection txn, String table) throws DbException {
+		PreparedStatement ps = null;
+		ResultSet rs = null;
+		try {
+			String sql = "CALL DISK_SPACE_USED(?)";
+			ps = txn.prepareStatement(sql);
+			ps.setString(1, table);
+			rs = ps.executeQuery();
+			if (!rs.next()) {
+				rs.close();
+				ps.close();
+			}
+			long size = rs.getLong(1);
+			if (rs.next()) throw new DbStateException();
+			rs.close();
+			ps.close();
+			LOG.info(String.format("Size of table %s: %d", table, size));
+		} catch (SQLException e) {
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+
 	@Override
 	protected Connection createConnection() throws DbException, SQLException {
 		SecretKey key = this.key;

bramble-core/src/main/java/org/briarproject/bramble/db/HyperSqlDatabase.java

@@ -93,6 +93,11 @@ class HyperSqlDatabase extends JdbcDatabase {
 		}
 	}
 
+	@Override
+	public void printStats(Connection txn) throws DbException {
+		// Not implemented
+	}
+
 	@Override
 	protected Connection createConnection() throws DbException, SQLException {
 		SecretKey key = this.key;

bramble-core/src/main/java/org/briarproject/bramble/db/JdbcDatabase.java

@@ -51,6 +51,7 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.LinkedHashMap;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
@@ -69,14 +70,12 @@ import static java.sql.Types.BOOLEAN;
 import static java.sql.Types.INTEGER;
 import static java.sql.Types.VARCHAR;
 import static java.util.Arrays.asList;
-import static java.util.logging.Level.FINE;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.db.DatabaseComponent.NO_CLEANUP_DEADLINE;
 import static org.briarproject.bramble.api.db.DatabaseComponent.TIMER_NOT_STARTED;
 import static org.briarproject.bramble.api.db.Metadata.REMOVE;
-import static org.briarproject.bramble.api.record.Record.RECORD_HEADER_BYTES;
 import static org.briarproject.bramble.api.sync.Group.Visibility.INVISIBLE;
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
 import static org.briarproject.bramble.api.sync.Group.Visibility.VISIBLE;
@@ -103,11 +102,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 	// Package access for testing
 	static final int CODE_SCHEMA_VERSION = 50;
 
-	/**
-	 * The maximum number of idle connections to keep open.
-	 */
-	private static final int MAX_CONNECTION_POOL_SIZE = 1;
-
 	// Time period offsets for incoming transport keys
 	private static final int OFFSET_PREV = -1;
 	private static final int OFFSET_CURR = 0;
@@ -369,7 +363,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 	private final Condition connectionsChanged = connectionsLock.newCondition();
 
 	@GuardedBy("connectionsLock")
-	private final LinkedList<Connection> connectionPool = new LinkedList<>();
+	private final LinkedList<Connection> connections = new LinkedList<>();
 
 	@GuardedBy("connectionsLock")
 	private int openConnections = 0;
@@ -577,8 +571,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		connectionsLock.lock();
 		try {
 			if (closed) throw new DbClosedException();
-			txn = connectionPool.poll();
-			logConnectionCounts();
+			txn = connections.poll();
 		} finally {
 			connectionsLock.unlock();
 		}
@@ -589,14 +582,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 				txn.setAutoCommit(false);
 				connectionsLock.lock();
 				try {
-					// The DB may have been closed since the check above
-					if (closed) {
-						tryToClose(txn, LOG, WARNING);
-						throw new DbClosedException();
-					}
 					openConnections++;
-					logConnectionCounts();
-					connectionsChanged.signalAll();
 				} finally {
 					connectionsLock.unlock();
 				}
@@ -607,91 +593,67 @@ abstract class JdbcDatabase implements Database<Connection> {
 		return txn;
 	}
 
-	@GuardedBy("connectionsLock")
-	private void logConnectionCounts() {
-		if (LOG.isLoggable(FINE)) {
-			LOG.fine(openConnections + " connections open, "
-					+ connectionPool.size() + " in pool");
-		}
-	}
-
 	@Override
 	public void abortTransaction(Connection txn) {
-		// The transaction may have been aborted due to an earlier exception,
-		// so close the connection rather than returning it to the pool
 		try {
 			txn.rollback();
+			connectionsLock.lock();
+			try {
+				connections.add(txn);
+				connectionsChanged.signalAll();
+			} finally {
+				connectionsLock.unlock();
+			}
 		} catch (SQLException e) {
+			// Try to close the connection
 			logException(LOG, WARNING, e);
-		}
-		closeConnection(txn);
-	}
-
-	private void closeConnection(Connection txn) {
-		tryToClose(txn, LOG, WARNING);
-		connectionsLock.lock();
-		try {
-			openConnections--;
-			logConnectionCounts();
-			connectionsChanged.signalAll();
-		} finally {
-			connectionsLock.unlock();
+			tryToClose(txn, LOG, WARNING);
+			// Whatever happens, allow the database to close
+			connectionsLock.lock();
+			try {
+				openConnections--;
+				connectionsChanged.signalAll();
+			} finally {
+				connectionsLock.unlock();
+			}
 		}
 	}
 
 	@Override
 	public void commitTransaction(Connection txn) throws DbException {
-		// If the transaction commits successfully then return the connection
-		// to the pool, otherwise close it
 		try {
 			txn.commit();
-			returnConnectionToPool(txn);
 		} catch (SQLException e) {
-			logException(LOG, WARNING, e);
-			closeConnection(txn);
 			throw new DbException(e);
 		}
-	}
-
-	private void returnConnectionToPool(Connection txn) {
-		boolean shouldClose;
 		connectionsLock.lock();
 		try {
-			shouldClose = connectionPool.size() >= MAX_CONNECTION_POOL_SIZE;
-			if (shouldClose) openConnections--;
-			else connectionPool.add(txn);
-			logConnectionCounts();
+			connections.add(txn);
 			connectionsChanged.signalAll();
 		} finally {
 			connectionsLock.unlock();
 		}
-		if (shouldClose) tryToClose(txn, LOG, WARNING);
 	}
 
-	void closeAllConnections() {
+	void closeAllConnections() throws SQLException {
 		boolean interrupted = false;
 		connectionsLock.lock();
 		try {
 			closed = true;
-			for (Connection c : connectionPool) tryToClose(c, LOG, WARNING);
-			openConnections -= connectionPool.size();
-			connectionPool.clear();
+			for (Connection c : connections) c.close();
+			openConnections -= connections.size();
+			connections.clear();
 			while (openConnections > 0) {
-				if (LOG.isLoggable(INFO)) {
-					LOG.info("Waiting for " + openConnections
-							+ " connections to be closed");
-				}
 				try {
 					connectionsChanged.await();
 				} catch (InterruptedException e) {
 					LOG.warning("Interrupted while closing connections");
 					interrupted = true;
 				}
-				for (Connection c : connectionPool) tryToClose(c, LOG, WARNING);
-				openConnections -= connectionPool.size();
-				connectionPool.clear();
+				for (Connection c : connections) c.close();
+				openConnections -= connections.size();
+				connections.clear();
 			}
-			LOG.info("All connections closed");
 		} finally {
 			connectionsLock.unlock();
 		}
@@ -1147,8 +1109,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public boolean containsAcksToSend(Connection txn, ContactId c)
-			throws DbException {
+	public boolean containsAnythingToSend(Connection txn, ContactId c,
+			long maxLatency, boolean eager) throws DbException {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
@@ -1160,7 +1122,34 @@ abstract class JdbcDatabase implements Database<Connection> {
 			boolean acksToSend = rs.next();
 			rs.close();
 			ps.close();
-			return acksToSend;
+			if (acksToSend) return true;
+			if (eager) {
+				sql = "SELECT NULL from statuses"
+						+ " WHERE contactId = ? AND state = ?"
+						+ " AND groupShared = TRUE AND messageShared = TRUE"
+						+ " AND deleted = FALSE AND seen = FALSE";
+				ps = txn.prepareStatement(sql);
+				ps.setInt(1, c.getInt());
+				ps.setInt(2, DELIVERED.getValue());
+			} else {
+				long now = clock.currentTimeMillis();
+				sql = "SELECT NULL FROM statuses"
+						+ " WHERE contactId = ? AND state = ?"
+						+ " AND groupShared = TRUE AND messageShared = TRUE"
+						+ " AND deleted = FALSE AND seen = FALSE"
+						+ " AND (expiry <= ? OR maxLatency IS NULL"
+						+ " OR ? < maxLatency)";
+				ps = txn.prepareStatement(sql);
+				ps.setInt(1, c.getInt());
+				ps.setInt(2, DELIVERED.getValue());
+				ps.setLong(3, now);
+				ps.setLong(4, maxLatency);
+			}
+			rs = ps.executeQuery();
+			boolean messagesToSend = rs.next();
+			rs.close();
+			ps.close();
+			return messagesToSend;
 		} catch (SQLException e) {
 			tryToClose(rs, LOG, WARNING);
 			tryToClose(ps, LOG, WARNING);
@@ -1280,46 +1269,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
-	@Override
-	public boolean containsMessagesToSend(Connection txn, ContactId c,
-			long maxLatency, boolean eager) throws DbException {
-		PreparedStatement ps = null;
-		ResultSet rs = null;
-		try {
-			if (eager) {
-				String sql = "SELECT NULL from statuses"
-						+ " WHERE contactId = ? AND state = ?"
-						+ " AND groupShared = TRUE AND messageShared = TRUE"
-						+ " AND deleted = FALSE AND seen = FALSE";
-				ps = txn.prepareStatement(sql);
-				ps.setInt(1, c.getInt());
-				ps.setInt(2, DELIVERED.getValue());
-			} else {
-				long now = clock.currentTimeMillis();
-				String sql = "SELECT NULL FROM statuses"
-						+ " WHERE contactId = ? AND state = ?"
-						+ " AND groupShared = TRUE AND messageShared = TRUE"
-						+ " AND deleted = FALSE AND seen = FALSE"
-						+ " AND (expiry <= ? OR maxLatency IS NULL"
-						+ " OR ? < maxLatency)";
-				ps = txn.prepareStatement(sql);
-				ps.setInt(1, c.getInt());
-				ps.setInt(2, DELIVERED.getValue());
-				ps.setLong(3, now);
-				ps.setLong(4, maxLatency);
-			}
-			rs = ps.executeQuery();
-			boolean messagesToSend = rs.next();
-			rs.close();
-			ps.close();
-			return messagesToSend;
-		} catch (SQLException e) {
-			tryToClose(rs, LOG, WARNING);
-			tryToClose(ps, LOG, WARNING);
-			throw new DbException(e);
-		}
-	}
-
 	@Override
 	public boolean containsPendingContact(Connection txn, PendingContactId p)
 			throws DbException {
@@ -1930,31 +1879,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
-	@Override
-	public int getMessageLength(Connection txn, MessageId m)
-			throws DbException {
-		PreparedStatement ps = null;
-		ResultSet rs = null;
-		try {
-			String sql = "SELECT length from messages"
-					+ " WHERE messageId = ? AND state = ?";
-			ps = txn.prepareStatement(sql);
-			ps.setBytes(1, m.getBytes());
-			ps.setInt(2, DELIVERED.getValue());
-			rs = ps.executeQuery();
-			if (!rs.next()) throw new DbStateException();
-			int length = rs.getInt(1);
-			if (rs.next()) throw new DbStateException();
-			rs.close();
-			ps.close();
-			return length;
-		} catch (SQLException e) {
-			tryToClose(rs, LOG, WARNING);
-			tryToClose(ps, LOG, WARNING);
-			throw new DbException(e);
-		}
-	}
-
 	@Override
 	public Map<MessageId, Metadata> getMessageMetadata(Connection txn,
 			GroupId g) throws DbException {
@@ -2303,8 +2227,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public Collection<MessageId> getMessagesToSend(Connection txn,
-			ContactId c, long capacity, long maxLatency) throws DbException {
+	public Collection<MessageId> getMessagesToSend(Connection txn, ContactId c,
+			int maxLength, long maxLatency) throws DbException {
 		long now = clock.currentTimeMillis();
 		PreparedStatement ps = null;
 		ResultSet rs = null;
@@ -2324,11 +2248,12 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setLong(4, maxLatency);
 			rs = ps.executeQuery();
 			List<MessageId> ids = new ArrayList<>();
+			int total = 0;
 			while (rs.next()) {
 				int length = rs.getInt(1);
-				if (capacity < RECORD_HEADER_BYTES + length) break;
+				if (total + length > maxLength) break;
 				ids.add(new MessageId(rs.getBytes(2)));
-				capacity -= RECORD_HEADER_BYTES + length;
+				total += length;
 			}
 			rs.close();
 			ps.close();
@@ -2341,12 +2266,12 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public Collection<MessageId> getUnackedMessagesToSend(Connection txn,
+	public Map<MessageId, Integer> getUnackedMessagesToSend(Connection txn,
 			ContactId c) throws DbException {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
-			String sql = "SELECT messageId FROM statuses"
+			String sql = "SELECT length, messageId FROM statuses"
 					+ " WHERE contactId = ? AND state = ?"
 					+ " AND groupShared = TRUE AND messageShared = TRUE"
 					+ " AND deleted = FALSE AND seen = FALSE"
@@ -2355,11 +2280,15 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setInt(1, c.getInt());
 			ps.setInt(2, DELIVERED.getValue());
 			rs = ps.executeQuery();
-			List<MessageId> ids = new ArrayList<>();
-			while (rs.next()) ids.add(new MessageId(rs.getBytes(1)));
+			Map<MessageId, Integer> results = new LinkedHashMap<>();
+			while (rs.next()) {
+				int length = rs.getInt(1);
+				MessageId id = new MessageId(rs.getBytes(2));
+				results.put(id, length);
+			}
 			rs.close();
 			ps.close();
-			return ids;
+			return results;
 		} catch (SQLException e) {
 			tryToClose(rs, LOG, WARNING);
 			tryToClose(ps, LOG, WARNING);
@@ -2472,7 +2401,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 				MessageId m = new MessageId(rs.getBytes(1));
 				GroupId g = new GroupId(rs.getBytes(2));
 				Collection<MessageId> messageIds = ids.get(g);
-				//noinspection Java8MapApi
 				if (messageIds == null) {
 					messageIds = new ArrayList<>();
 					ids.put(g, messageIds);
@@ -2490,28 +2418,12 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public long getNextSendTime(Connection txn, ContactId c, long maxLatency)
+	public long getNextSendTime(Connection txn, ContactId c)
 			throws DbException {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
-			// Are any messages sendable immediately?
-			String sql = "SELECT NULL FROM statuses"
-					+ " WHERE contactId = ? AND state = ?"
-					+ " AND groupShared = TRUE AND messageShared = TRUE"
-					+ " AND deleted = FALSE AND seen = FALSE"
-					+ " AND (maxLatency IS NULL OR ? < maxLatency)";
-			ps = txn.prepareStatement(sql);
-			ps.setInt(1, c.getInt());
-			ps.setInt(2, DELIVERED.getValue());
-			ps.setLong(3, maxLatency);
-			rs = ps.executeQuery();
-			boolean found = rs.next();
-			rs.close();
-			ps.close();
-			if (found) return 0;
-			// When is the earliest expiry time (could be in the past)?
-			sql = "SELECT expiry FROM statuses"
+			String sql = "SELECT expiry FROM statuses"
 					+ " WHERE contactId = ? AND state = ?"
 					+ " AND groupShared = TRUE AND messageShared = TRUE"
 					+ " AND deleted = FALSE AND seen = FALSE"
@@ -2615,7 +2527,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 
 	@Override
 	public Collection<MessageId> getRequestedMessagesToSend(Connection txn,
-			ContactId c, long capacity, long maxLatency) throws DbException {
+			ContactId c, int maxLength, long maxLatency) throws DbException {
 		long now = clock.currentTimeMillis();
 		PreparedStatement ps = null;
 		ResultSet rs = null;
@@ -2635,11 +2547,12 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setLong(4, maxLatency);
 			rs = ps.executeQuery();
 			List<MessageId> ids = new ArrayList<>();
+			int total = 0;
 			while (rs.next()) {
 				int length = rs.getInt(1);
-				if (capacity < RECORD_HEADER_BYTES + length) break;
+				if (total + length > maxLength) break;
 				ids.add(new MessageId(rs.getBytes(2)));
-				capacity -= RECORD_HEADER_BYTES + length;
+				total += length;
 			}
 			rs.close();
 			ps.close();
@@ -2793,7 +2706,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 				ContactId c = new ContactId(rs.getInt(1));
 				TransportId t = new TransportId(rs.getString(2));
 				Collection<TransportId> transportIds = ids.get(c);
-				//noinspection Java8MapApi
 				if (transportIds == null) {
 					transportIds = new ArrayList<>();
 					ids.put(c, transportIds);

bramble-core/src/main/java/org/briarproject/bramble/io/TimeoutMonitorImpl.java

@@ -1,10 +1,10 @@
 package org.briarproject.bramble.io;
 
-import org.briarproject.bramble.api.Cancellable;
 import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.system.TaskScheduler;
+import org.briarproject.bramble.api.system.TaskScheduler.Cancellable;
 import org.briarproject.bramble.api.system.Wakeful;
 
 import java.io.IOException;

bramble-core/src/main/java/org/briarproject/bramble/lifecycle/LifecycleManagerImpl.java

@@ -190,10 +190,6 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 			return;
 		}
 		try {
-			if (state == STOPPING) {
-				LOG.info("Already stopped");
-				return;
-			}
 			LOG.info("Stopping services");
 			state = STOPPING;
 			eventBus.broadcast(new LifecycleEvent(STOPPING));

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

@@ -1,21 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.lifecycle.IoExecutor;
-import org.briarproject.bramble.mailbox.MailboxApi.TolerableFailureException;
-
-/**
- * An interface for calling an API endpoint with the option to retry the call.
- */
-interface ApiCall {
-
-	/**
-	 * This method makes a synchronous call to an API endpoint and returns
-	 * true if the call should be retried, in which case the method may be
-	 * called again on the same {@link ApiCall} instance after a delay.
-	 *
-	 * @return True if the API call needs to be retried, or false if the API
-	 * call succeeded or {@link TolerableFailureException failed tolerably}.
-	 */
-	@IoExecutor
-	boolean callApi();
-}

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

@@ -1,43 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.ThreadSafe;
-
-/**
- * An interface for checking whether a mailbox is reachable.
- */
-@ThreadSafe
-@NotNullByDefault
-interface ConnectivityChecker {
-
-	/**
-	 * Destroys the checker. Any current connectivity check is cancelled.
-	 */
-	void destroy();
-
-	/**
-	 * Starts a connectivity check if needed and calls the given observer when
-	 * the check succeeds. If a check is already running then the observer is
-	 * called when the check succeeds. If a connectivity check has recently
-	 * succeeded then the observer is called immediately.
-	 * <p>
-	 * Observers are removed after being called, or when the checker is
-	 * {@link #destroy() destroyed}.
-	 */
-	void checkConnectivity(MailboxProperties properties,
-			ConnectivityObserver o);
-
-	/**
-	 * Removes an observer that was added via
-	 * {@link #checkConnectivity(MailboxProperties, ConnectivityObserver)}. If
-	 * there are no remaining observers and a connectivity check is running
-	 * then the check will be cancelled.
-	 */
-	void removeObserver(ConnectivityObserver o);
-
-	interface ConnectivityObserver {
-		void onConnectivityCheckSucceeded();
-	}
-}

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

@@ -1,122 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.Cancellable;
-import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.system.Clock;
-
-import java.util.ArrayList;
-import java.util.List;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.GuardedBy;
-import javax.annotation.concurrent.ThreadSafe;
-
-@ThreadSafe
-@NotNullByDefault
-abstract class ConnectivityCheckerImpl implements ConnectivityChecker {
-
-	/**
-	 * If no more than this much time has elapsed since the last connectivity
-	 * check succeeded, consider the result to be fresh and don't check again.
-	 * <p>
-	 * Package access for testing.
-	 */
-	static final long CONNECTIVITY_CHECK_FRESHNESS_MS = 10_000;
-
-	private final Object lock = new Object();
-
-	protected final Clock clock;
-	private final MailboxApiCaller mailboxApiCaller;
-
-	@GuardedBy("lock")
-	private boolean destroyed = false;
-
-	@GuardedBy("lock")
-	@Nullable
-	private Cancellable connectivityCheck = null;
-
-	@GuardedBy("lock")
-	private long lastConnectivityCheckSucceeded = 0;
-
-	@GuardedBy("lock")
-	private final List<ConnectivityObserver> connectivityObservers =
-			new ArrayList<>();
-
-	/**
-	 * Creates an {@link ApiCall} for checking whether the mailbox is
-	 * reachable. The {@link ApiCall} should call
-	 * {@link #onConnectivityCheckSucceeded(long)} if the check succeeds.
-	 */
-	abstract ApiCall createConnectivityCheckTask(MailboxProperties properties);
-
-	ConnectivityCheckerImpl(Clock clock, MailboxApiCaller mailboxApiCaller) {
-		this.clock = clock;
-		this.mailboxApiCaller = mailboxApiCaller;
-	}
-
-	@Override
-	public void destroy() {
-		synchronized (lock) {
-			destroyed = true;
-			connectivityObservers.clear();
-			if (connectivityCheck != null) {
-				connectivityCheck.cancel();
-				connectivityCheck = null;
-			}
-		}
-	}
-
-	@Override
-	public void checkConnectivity(MailboxProperties properties,
-			ConnectivityObserver o) {
-		boolean callNow = false;
-		synchronized (lock) {
-			if (destroyed) return;
-			if (connectivityCheck == null) {
-				// No connectivity check is running
-				long now = clock.currentTimeMillis();
-				if (now - lastConnectivityCheckSucceeded
-						> CONNECTIVITY_CHECK_FRESHNESS_MS) {
-					// The last connectivity check is stale, start a new one
-					connectivityObservers.add(o);
-					ApiCall task = createConnectivityCheckTask(properties);
-					connectivityCheck = mailboxApiCaller.retryWithBackoff(task);
-				} else {
-					// The last connectivity check is fresh
-					callNow = true;
-				}
-			} else {
-				// A connectivity check is running, wait for it to succeed
-				connectivityObservers.add(o);
-			}
-		}
-		if (callNow) o.onConnectivityCheckSucceeded();
-	}
-
-	protected void onConnectivityCheckSucceeded(long now) {
-		List<ConnectivityObserver> observers;
-		synchronized (lock) {
-			if (destroyed) return;
-			connectivityCheck = null;
-			lastConnectivityCheckSucceeded = now;
-			observers = new ArrayList<>(connectivityObservers);
-			connectivityObservers.clear();
-		}
-		for (ConnectivityObserver o : observers) {
-			o.onConnectivityCheckSucceeded();
-		}
-	}
-
-	@Override
-	public void removeObserver(ConnectivityObserver o) {
-		synchronized (lock) {
-			if (destroyed) return;
-			connectivityObservers.remove(o);
-			if (connectivityObservers.isEmpty() && connectivityCheck != null) {
-				connectivityCheck.cancel();
-				connectivityCheck = null;
-			}
-		}
-	}
-}

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

@@ -1,122 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.mailbox.MailboxFolderId;
-import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import java.util.logging.Logger;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.GuardedBy;
-import javax.annotation.concurrent.ThreadSafe;
-import javax.inject.Inject;
-
-import static java.util.logging.Logger.getLogger;
-
-@ThreadSafe
-@NotNullByDefault
-class ContactMailboxClient implements MailboxClient {
-
-	private static final Logger LOG =
-			getLogger(ContactMailboxClient.class.getName());
-
-	private final MailboxWorkerFactory workerFactory;
-	private final ConnectivityChecker connectivityChecker;
-	private final TorReachabilityMonitor reachabilityMonitor;
-	private final Object lock = new Object();
-
-	@GuardedBy("lock")
-	@Nullable
-	private MailboxWorker uploadWorker = null, downloadWorker = null;
-
-	@Inject
-	ContactMailboxClient(MailboxWorkerFactory workerFactory,
-			ConnectivityChecker connectivityChecker,
-			TorReachabilityMonitor reachabilityMonitor) {
-		this.workerFactory = workerFactory;
-		this.connectivityChecker = connectivityChecker;
-		this.reachabilityMonitor = reachabilityMonitor;
-	}
-
-	@Override
-	public void start() {
-		LOG.info("Started");
-		// Nothing to do until contact is assigned
-	}
-
-	@Override
-	public void destroy() {
-		LOG.info("Destroyed");
-		MailboxWorker uploadWorker, downloadWorker;
-		synchronized (lock) {
-			uploadWorker = this.uploadWorker;
-			this.uploadWorker = null;
-			downloadWorker = this.downloadWorker;
-			this.downloadWorker = null;
-		}
-		if (uploadWorker != null) uploadWorker.destroy();
-		if (downloadWorker != null) downloadWorker.destroy();
-	}
-
-	@Override
-	public void assignContactForUpload(ContactId contactId,
-			MailboxProperties properties, MailboxFolderId folderId) {
-		LOG.info("Contact assigned for upload");
-		if (properties.isOwner()) throw new IllegalArgumentException();
-		// For a contact's mailbox we should always be uploading to the outbox
-		// assigned to us by the contact
-		if (!folderId.equals(properties.getOutboxId())) {
-			throw new IllegalArgumentException();
-		}
-		MailboxWorker uploadWorker = workerFactory.createUploadWorker(
-				connectivityChecker, properties, folderId, contactId);
-		synchronized (lock) {
-			if (this.uploadWorker != null) throw new IllegalStateException();
-			this.uploadWorker = uploadWorker;
-		}
-		uploadWorker.start();
-	}
-
-	@Override
-	public void deassignContactForUpload(ContactId contactId) {
-		LOG.info("Contact deassigned for upload");
-		MailboxWorker uploadWorker;
-		synchronized (lock) {
-			uploadWorker = this.uploadWorker;
-			this.uploadWorker = null;
-		}
-		if (uploadWorker != null) uploadWorker.destroy();
-	}
-
-	@Override
-	public void assignContactForDownload(ContactId contactId,
-			MailboxProperties properties, MailboxFolderId folderId) {
-		LOG.info("Contact assigned for download");
-		if (properties.isOwner()) throw new IllegalArgumentException();
-		// For a contact's mailbox we should always be downloading from the
-		// inbox assigned to us by the contact
-		if (!folderId.equals(properties.getInboxId())) {
-			throw new IllegalArgumentException();
-		}
-		MailboxWorker downloadWorker =
-				workerFactory.createDownloadWorkerForContactMailbox(
-						connectivityChecker, reachabilityMonitor, properties);
-		synchronized (lock) {
-			if (this.downloadWorker != null) throw new IllegalStateException();
-			this.downloadWorker = downloadWorker;
-		}
-		downloadWorker.start();
-	}
-
-	@Override
-	public void deassignContactForDownload(ContactId contactId) {
-		LOG.info("Contact deassigned for download");
-		MailboxWorker downloadWorker;
-		synchronized (lock) {
-			downloadWorker = this.downloadWorker;
-			this.downloadWorker = null;
-		}
-		if (downloadWorker != null) downloadWorker.destroy();
-	}
-}

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

@@ -1,32 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.system.Clock;
-import org.briarproject.bramble.mailbox.MailboxApi.ApiException;
-
-import javax.annotation.concurrent.ThreadSafe;
-
-@ThreadSafe
-@NotNullByDefault
-class ContactMailboxConnectivityChecker extends ConnectivityCheckerImpl {
-
-	private final MailboxApi mailboxApi;
-
-	ContactMailboxConnectivityChecker(Clock clock,
-			MailboxApiCaller mailboxApiCaller, MailboxApi mailboxApi) {
-		super(clock, mailboxApiCaller);
-		this.mailboxApi = mailboxApi;
-	}
-
-	@Override
-	ApiCall createConnectivityCheckTask(MailboxProperties properties) {
-		if (properties.isOwner()) throw new IllegalArgumentException();
-		return new SimpleApiCall(() -> {
-			if (!mailboxApi.checkStatus(properties)) throw new ApiException();
-			// Call the observers and cache the result
-			onConnectivityCheckSucceeded(clock.currentTimeMillis());
-		});
-	}
-
-}

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

@@ -1,243 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.Cancellable;
-import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.mailbox.ConnectivityChecker.ConnectivityObserver;
-import org.briarproject.bramble.mailbox.MailboxApi.ApiException;
-import org.briarproject.bramble.mailbox.MailboxApi.MailboxFile;
-import org.briarproject.bramble.mailbox.MailboxApi.TolerableFailureException;
-import org.briarproject.bramble.mailbox.TorReachabilityMonitor.TorReachabilityObserver;
-
-import java.io.File;
-import java.io.IOException;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Queue;
-import java.util.logging.Logger;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.GuardedBy;
-import javax.annotation.concurrent.ThreadSafe;
-
-import static java.util.logging.Level.INFO;
-import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@ThreadSafe
-@NotNullByDefault
-class ContactMailboxDownloadWorker implements MailboxWorker,
-		ConnectivityObserver, TorReachabilityObserver {
-
-	/**
-	 * When the worker is started it waits for a connectivity check, then
-	 * starts its first download cycle: checking the inbox, downloading and
-	 * deleting any files, and checking again until the inbox is empty.
-	 * <p>
-	 * The worker then waits for our Tor hidden service to be reachable before
-	 * starting its second download cycle. This ensures that if a contact
-	 * tried and failed to connect to our hidden service before it was
-	 * reachable, and therefore uploaded a file to the mailbox instead, we'll
-	 * find the file in the second download cycle.
-	 */
-	private enum State {
-		CREATED,
-		CONNECTIVITY_CHECK,
-		DOWNLOAD_CYCLE_1,
-		WAITING_FOR_TOR,
-		DOWNLOAD_CYCLE_2,
-		FINISHED,
-		DESTROYED
-	}
-
-	private static final Logger LOG =
-			getLogger(ContactMailboxDownloadWorker.class.getName());
-
-	private final ConnectivityChecker connectivityChecker;
-	private final TorReachabilityMonitor torReachabilityMonitor;
-	private final MailboxApiCaller mailboxApiCaller;
-	private final MailboxApi mailboxApi;
-	private final MailboxFileManager mailboxFileManager;
-	private final MailboxProperties mailboxProperties;
-	private final Object lock = new Object();
-
-	@GuardedBy("lock")
-	private State state = State.CREATED;
-
-	@GuardedBy("lock")
-	@Nullable
-	private Cancellable apiCall = null;
-
-	ContactMailboxDownloadWorker(
-			ConnectivityChecker connectivityChecker,
-			TorReachabilityMonitor torReachabilityMonitor,
-			MailboxApiCaller mailboxApiCaller,
-			MailboxApi mailboxApi,
-			MailboxFileManager mailboxFileManager,
-			MailboxProperties mailboxProperties) {
-		if (mailboxProperties.isOwner()) throw new IllegalArgumentException();
-		this.connectivityChecker = connectivityChecker;
-		this.torReachabilityMonitor = torReachabilityMonitor;
-		this.mailboxApiCaller = mailboxApiCaller;
-		this.mailboxApi = mailboxApi;
-		this.mailboxFileManager = mailboxFileManager;
-		this.mailboxProperties = mailboxProperties;
-	}
-
-	@Override
-	public void start() {
-		LOG.info("Started");
-		synchronized (lock) {
-			// Don't allow the worker to be reused
-			if (state != State.CREATED) return;
-			state = State.CONNECTIVITY_CHECK;
-		}
-		// Avoid leaking observer in case destroy() is called concurrently
-		// before observer is added
-		connectivityChecker.checkConnectivity(mailboxProperties, this);
-		boolean destroyed;
-		synchronized (lock) {
-			destroyed = state == State.DESTROYED;
-		}
-		if (destroyed) connectivityChecker.removeObserver(this);
-	}
-
-	@Override
-	public void destroy() {
-		LOG.info("Destroyed");
-		Cancellable apiCall;
-		synchronized (lock) {
-			state = State.DESTROYED;
-			apiCall = this.apiCall;
-			this.apiCall = null;
-		}
-		if (apiCall != null) apiCall.cancel();
-		connectivityChecker.removeObserver(this);
-		torReachabilityMonitor.removeObserver(this);
-	}
-
-	@Override
-	public void onConnectivityCheckSucceeded() {
-		LOG.info("Connectivity check succeeded");
-		synchronized (lock) {
-			if (state != State.CONNECTIVITY_CHECK) return;
-			state = State.DOWNLOAD_CYCLE_1;
-			// Start first download cycle
-			apiCall = mailboxApiCaller.retryWithBackoff(
-					new SimpleApiCall(this::apiCallListInbox));
-		}
-	}
-
-	private void apiCallListInbox() throws IOException, ApiException {
-		synchronized (lock) {
-			if (state == State.DESTROYED) return;
-		}
-		LOG.info("Listing inbox");
-		List<MailboxFile> files = mailboxApi.getFiles(mailboxProperties,
-				requireNonNull(mailboxProperties.getInboxId()));
-		if (files.isEmpty()) onDownloadCycleFinished();
-		else downloadNextFile(new LinkedList<>(files));
-	}
-
-	private void onDownloadCycleFinished() {
-		boolean addObserver = false;
-		synchronized (lock) {
-			if (state == State.DOWNLOAD_CYCLE_1) {
-				LOG.info("First download cycle finished");
-				state = State.WAITING_FOR_TOR;
-				apiCall = null;
-				addObserver = true;
-			} else if (state == State.DOWNLOAD_CYCLE_2) {
-				LOG.info("Second download cycle finished");
-				state = State.FINISHED;
-				apiCall = null;
-			}
-		}
-		if (addObserver) {
-			// Avoid leaking observer in case destroy() is called concurrently
-			// before observer is added
-			torReachabilityMonitor.addOneShotObserver(this);
-			boolean destroyed;
-			synchronized (lock) {
-				destroyed = state == State.DESTROYED;
-			}
-			if (destroyed) torReachabilityMonitor.removeObserver(this);
-		}
-	}
-
-	private void downloadNextFile(Queue<MailboxFile> queue) {
-		synchronized (lock) {
-			if (state == State.DESTROYED) return;
-			MailboxFile file = queue.remove();
-			apiCall = mailboxApiCaller.retryWithBackoff(
-					new SimpleApiCall(() -> apiCallDownloadFile(file, queue)));
-		}
-	}
-
-	private void apiCallDownloadFile(MailboxFile file,
-			Queue<MailboxFile> queue) throws IOException, ApiException {
-		synchronized (lock) {
-			if (state == State.DESTROYED) return;
-		}
-		LOG.info("Downloading file");
-		File tempFile = mailboxFileManager.createTempFileForDownload();
-		try {
-			mailboxApi.getFile(mailboxProperties,
-					requireNonNull(mailboxProperties.getInboxId()),
-					file.name, tempFile);
-		} catch (IOException | ApiException e) {
-			if (!tempFile.delete()) {
-				LOG.warning("Failed to delete temporary file");
-			}
-			throw e;
-		}
-		mailboxFileManager.handleDownloadedFile(tempFile);
-		deleteFile(file, queue);
-	}
-
-	private void deleteFile(MailboxFile file, Queue<MailboxFile> queue) {
-		synchronized (lock) {
-			if (state == State.DESTROYED) return;
-			apiCall = mailboxApiCaller.retryWithBackoff(
-					new SimpleApiCall(() -> apiCallDeleteFile(file, queue)));
-		}
-	}
-
-	private void apiCallDeleteFile(MailboxFile file, Queue<MailboxFile> queue)
-			throws IOException, ApiException {
-		synchronized (lock) {
-			if (state == State.DESTROYED) return;
-		}
-		try {
-			mailboxApi.deleteFile(mailboxProperties,
-					requireNonNull(mailboxProperties.getInboxId()), file.name);
-		} catch (TolerableFailureException e) {
-			// Catch this so we can continue to the next file
-			logException(LOG, INFO, e);
-		}
-		if (queue.isEmpty()) {
-			// List the inbox again to check for files that may have arrived
-			// while we were downloading
-			synchronized (lock) {
-				if (state == State.DESTROYED) return;
-				apiCall = mailboxApiCaller.retryWithBackoff(
-						new SimpleApiCall(this::apiCallListInbox));
-			}
-		} else {
-			downloadNextFile(queue);
-		}
-	}
-
-	@Override
-	public void onTorReachable() {
-		LOG.info("Our Tor hidden service is reachable");
-		synchronized (lock) {
-			if (state != State.WAITING_FOR_TOR) return;
-			state = State.DOWNLOAD_CYCLE_2;
-			// Start second download cycle
-			apiCall = mailboxApiCaller.retryWithBackoff(
-					new SimpleApiCall(this::apiCallListInbox));
-		}
-	}
-}

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

@@ -7,8 +7,6 @@ import org.briarproject.bramble.api.mailbox.MailboxAuthToken;
 import org.briarproject.bramble.api.mailbox.MailboxFileId;
 import org.briarproject.bramble.api.mailbox.MailboxFolderId;
 import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.mailbox.MailboxVersion;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import java.io.File;
 import java.io.IOException;
@@ -18,12 +16,8 @@ import java.util.List;
 import javax.annotation.Nonnull;
 import javax.annotation.concurrent.Immutable;
 
-@NotNullByDefault
 interface MailboxApi {
 
-	List<MailboxVersion> getServerSupports(MailboxProperties properties)
-			throws IOException, ApiException;
-
 	/**
 	 * Sets up the mailbox with the setup token.
 	 *

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

@@ -1,34 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.Cancellable;
-import org.briarproject.bramble.api.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import static java.util.concurrent.TimeUnit.DAYS;
-import static java.util.concurrent.TimeUnit.MINUTES;
-
-@NotNullByDefault
-interface MailboxApiCaller {
-
-	/**
-	 * The minimum interval between retries in milliseconds.
-	 */
-	long MIN_RETRY_INTERVAL_MS = MINUTES.toMillis(1);
-
-	/**
-	 * The maximum interval between retries in milliseconds.
-	 */
-	long MAX_RETRY_INTERVAL_MS = DAYS.toMillis(1);
-
-	/**
-	 * Asynchronously calls the given API call on the {@link IoExecutor},
-	 * automatically retrying at increasing intervals until the API call
-	 * returns false or retries are cancelled.
-	 * <p>
-	 * This method is safe to call while holding a lock.
-	 *
-	 * @return A {@link Cancellable} that can be used to cancel any future
-	 * retries.
-	 */
-	Cancellable retryWithBackoff(ApiCall apiCall);
-}

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

@@ -1,98 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.Cancellable;
-import org.briarproject.bramble.api.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.system.TaskScheduler;
-
-import java.util.concurrent.Executor;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.GuardedBy;
-import javax.annotation.concurrent.Immutable;
-import javax.inject.Inject;
-
-import static java.lang.Math.min;
-import static java.util.concurrent.TimeUnit.MILLISECONDS;
-
-@Immutable
-@NotNullByDefault
-class MailboxApiCallerImpl implements MailboxApiCaller {
-
-	private final TaskScheduler taskScheduler;
-	private final Executor ioExecutor;
-
-	@Inject
-	MailboxApiCallerImpl(TaskScheduler taskScheduler,
-			@IoExecutor Executor ioExecutor) {
-		this.taskScheduler = taskScheduler;
-		this.ioExecutor = ioExecutor;
-	}
-
-	@Override
-	public Cancellable retryWithBackoff(ApiCall apiCall) {
-		Task task = new Task(apiCall);
-		task.start();
-		return task;
-	}
-
-	private class Task implements Cancellable {
-
-		private final ApiCall apiCall;
-		private final Object lock = new Object();
-
-		@GuardedBy("lock")
-		@Nullable
-		private Cancellable scheduledTask = null;
-
-		@GuardedBy("lock")
-		private boolean cancelled = false;
-
-		@GuardedBy("lock")
-		private long retryIntervalMs = MIN_RETRY_INTERVAL_MS;
-
-		private Task(ApiCall apiCall) {
-			this.apiCall = apiCall;
-		}
-
-		private void start() {
-			synchronized (lock) {
-				if (cancelled) throw new AssertionError();
-				ioExecutor.execute(this::callApi);
-			}
-		}
-
-		@IoExecutor
-		private void callApi() {
-			synchronized (lock) {
-				if (cancelled) return;
-			}
-			// The call returns true if we should retry
-			if (apiCall.callApi()) {
-				synchronized (lock) {
-					if (cancelled) return;
-					scheduledTask = taskScheduler.schedule(this::callApi,
-							ioExecutor, retryIntervalMs, MILLISECONDS);
-					// Increase the retry interval each time we retry
-					retryIntervalMs =
-							min(MAX_RETRY_INTERVAL_MS, retryIntervalMs * 2);
-				}
-			} else {
-				synchronized (lock) {
-					scheduledTask = null;
-				}
-			}
-		}
-
-		@Override
-		public void cancel() {
-			Cancellable scheduledTask;
-			synchronized (lock) {
-				cancelled = true;
-				scheduledTask = this.scheduledTask;
-				this.scheduledTask = null;
-			}
-			if (scheduledTask != null) scheduledTask.cancel();
-		}
-	}
-}

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

@@ -42,39 +42,18 @@ import static org.briarproject.bramble.util.IoUtils.copyAndClose;
 @NotNullByDefault
 class MailboxApiImpl implements MailboxApi {
 
+	private final WeakSingletonProvider<OkHttpClient> httpClientProvider;
+	private final JsonMapper mapper = JsonMapper.builder()
+			.enable(BLOCK_UNSAFE_POLYMORPHIC_BASE_TYPES)
+			.build();
 	private static final MediaType JSON =
 			requireNonNull(MediaType.parse("application/json; charset=utf-8"));
 	private static final MediaType FILE =
 			requireNonNull(MediaType.parse("application/octet-stream"));
 
-	private final WeakSingletonProvider<OkHttpClient> httpClientProvider;
-	private final JsonMapper mapper = JsonMapper.builder()
-			.enable(BLOCK_UNSAFE_POLYMORPHIC_BASE_TYPES)
-			.build();
-	private final UrlConverter urlConverter;
-
 	@Inject
-	MailboxApiImpl(WeakSingletonProvider<OkHttpClient> httpClientProvider,
-			UrlConverter urlConverter) {
+	MailboxApiImpl(WeakSingletonProvider<OkHttpClient> httpClientProvider) {
 		this.httpClientProvider = httpClientProvider;
-		this.urlConverter = urlConverter;
-	}
-
-	@Override
-	public List<MailboxVersion> getServerSupports(MailboxProperties properties)
-			throws IOException, ApiException {
-		if (!properties.isOwner()) throw new IllegalArgumentException();
-		Response response = sendGetRequest(properties, "/versions");
-		if (response.code() != 200) throw new ApiException();
-
-		ResponseBody body = response.body();
-		if (body == null) throw new ApiException();
-		try {
-			JsonNode node = mapper.readTree(body.string());
-			return parseServerSupports(node);
-		} catch (JacksonException e) {
-			throw new ApiException();
-		}
 	}
 
 	@Override
@@ -82,7 +61,7 @@ class MailboxApiImpl implements MailboxApi {
 			throws IOException, ApiException {
 		if (!properties.isOwner()) throw new IllegalArgumentException();
 		Request request = getRequestBuilder(properties.getAuthToken())
-				.url(getBaseUrl(properties) + "/setup")
+				.url(properties.getBaseUrl() + "/setup")
 				.put(EMPTY_REQUEST)
 				.build();
 		OkHttpClient client = httpClientProvider.get();
@@ -97,40 +76,36 @@ class MailboxApiImpl implements MailboxApi {
 			if (tokenNode == null) {
 				throw new ApiException();
 			}
-			return new MailboxProperties(properties.getOnion(),
+			List<MailboxVersion> serverSupports = new ArrayList<>();
+			ArrayNode serverSupportsNode = getArray(node, "serverSupports");
+			for (JsonNode versionNode : serverSupportsNode) {
+				if (!versionNode.isObject()) throw new ApiException();
+				ObjectNode objectNode = (ObjectNode) versionNode;
+				JsonNode majorNode = objectNode.get("major");
+				JsonNode minorNode = objectNode.get("minor");
+				if (majorNode == null || !majorNode.isNumber()) {
+					throw new ApiException();
+				}
+				if (minorNode == null || !minorNode.isNumber()) {
+					throw new ApiException();
+				}
+				int major = majorNode.asInt();
+				int minor = minorNode.asInt();
+				if (major < 0 || minor < 0) throw new ApiException();
+				serverSupports.add(new MailboxVersion(major, minor));
+			}
+			return new MailboxProperties(properties.getBaseUrl(),
 					MailboxAuthToken.fromString(tokenNode.textValue()),
-					parseServerSupports(node));
+					true, serverSupports);
 		} catch (JacksonException | InvalidMailboxIdException e) {
 			throw new ApiException();
 		}
 	}
 
-	private List<MailboxVersion> parseServerSupports(JsonNode node)
-			throws ApiException {
-		List<MailboxVersion> serverSupports = new ArrayList<>();
-		ArrayNode serverSupportsNode = getArray(node, "serverSupports");
-		for (JsonNode versionNode : serverSupportsNode) {
-			if (!versionNode.isObject()) throw new ApiException();
-			ObjectNode objectNode = (ObjectNode) versionNode;
-			JsonNode majorNode = objectNode.get("major");
-			JsonNode minorNode = objectNode.get("minor");
-			if (majorNode == null || !majorNode.isNumber()) {
-				throw new ApiException();
-			}
-			if (minorNode == null || !minorNode.isNumber()) {
-				throw new ApiException();
-			}
-			int major = majorNode.asInt();
-			int minor = minorNode.asInt();
-			if (major < 0 || minor < 0) throw new ApiException();
-			serverSupports.add(new MailboxVersion(major, minor));
-		}
-		return serverSupports;
-	}
-
 	@Override
 	public boolean checkStatus(MailboxProperties properties)
 			throws IOException, ApiException {
+		if (!properties.isOwner()) throw new IllegalArgumentException();
 		Response response = sendGetRequest(properties, "/status");
 		if (response.code() == 401) throw new ApiException();
 		return response.isSuccessful();
@@ -141,7 +116,7 @@ class MailboxApiImpl implements MailboxApi {
 			throws IOException, ApiException {
 		if (!properties.isOwner()) throw new IllegalArgumentException();
 		Request request = getRequestBuilder(properties.getAuthToken())
-				.url(getBaseUrl(properties) + "/")
+				.url(properties.getBaseUrl() + "/")
 				.delete()
 				.build();
 		OkHttpClient client = httpClientProvider.get();
@@ -166,7 +141,7 @@ class MailboxApiImpl implements MailboxApi {
 	public void deleteContact(MailboxProperties properties, ContactId contactId)
 			throws IOException, ApiException, TolerableFailureException {
 		if (!properties.isOwner()) throw new IllegalArgumentException();
-		String url = getBaseUrl(properties) + "/contacts/" +
+		String url = properties.getBaseUrl() + "/contacts/" +
 				contactId.getInt();
 		Request request = getRequestBuilder(properties.getAuthToken())
 				.delete()
@@ -270,7 +245,7 @@ class MailboxApiImpl implements MailboxApi {
 		String path = "/files/" + folderId + "/" + fileId;
 		Request request = getRequestBuilder(properties.getAuthToken())
 				.delete()
-				.url(getBaseUrl(properties) + path)
+				.url(properties.getBaseUrl() + path)
 				.build();
 		OkHttpClient client = httpClientProvider.get();
 		Response response = client.newCall(request).execute();
@@ -312,7 +287,7 @@ class MailboxApiImpl implements MailboxApi {
 	private Response sendGetRequest(MailboxProperties properties, String path)
 			throws IOException {
 		Request request = getRequestBuilder(properties.getAuthToken())
-				.url(getBaseUrl(properties) + path)
+				.url(properties.getBaseUrl() + path)
 				.build();
 		OkHttpClient client = httpClientProvider.get();
 		return client.newCall(request).execute();
@@ -321,7 +296,7 @@ class MailboxApiImpl implements MailboxApi {
 	private Response sendPostRequest(MailboxProperties properties, String path,
 			RequestBody body) throws IOException {
 		Request request = getRequestBuilder(properties.getAuthToken())
-				.url(getBaseUrl(properties) + path)
+				.url(properties.getBaseUrl() + path)
 				.post(body)
 				.build();
 		OkHttpClient client = httpClientProvider.get();
@@ -343,7 +318,4 @@ class MailboxApiImpl implements MailboxApi {
 		return (ArrayNode) arrayNode;
 	}
 
-	private String getBaseUrl(MailboxProperties properties) {
-		return urlConverter.convertOnionToBaseUrl(properties.getOnion());
-	}
 }

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

@@ -1,46 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.mailbox.MailboxFolderId;
-import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.ThreadSafe;
-
-@ThreadSafe
-@NotNullByDefault
-interface MailboxClient {
-
-	/**
-	 * Asynchronously starts the client.
-	 */
-	void start();
-
-	/**
-	 * Destroys the client and its workers, cancelling any pending tasks or
-	 * retries.
-	 */
-	void destroy();
-
-	/**
-	 * Assigns a contact to the client for upload.
-	 */
-	void assignContactForUpload(ContactId c, MailboxProperties properties,
-			MailboxFolderId folderId);
-
-	/**
-	 * Deassigns a contact from the client for upload.
-	 */
-	void deassignContactForUpload(ContactId c);
-
-	/**
-	 * Assigns a contact to the client for download.
-	 */
-	void assignContactForDownload(ContactId c, MailboxProperties properties,
-			MailboxFolderId folderId);
-
-	/**
-	 * Deassigns a contact from the client for download.
-	 */
-	void deassignContactForDownload(ContactId c);
-}

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

@@ -1,34 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.OutgoingSessionRecord;
-
-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;
-
-	/**
-	 * Creates a file to be uploaded to the given contact and writes any
-	 * waiting data to the file. The IDs of any messages sent or acked will
-	 * be added to the given {@link OutgoingSessionRecord}.
-	 */
-	File createAndWriteTempFileForUpload(ContactId contactId,
-			OutgoingSessionRecord sessionRecord) 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

@@ -1,271 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-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.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.TransportConnectionWriter;
-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.api.sync.OutgoingSessionRecord;
-
-import java.io.File;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
-import java.util.concurrent.ArrayBlockingQueue;
-import java.util.concurrent.BlockingQueue;
-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.IoUtils.delete;
-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";
-	static final String UPLOAD_DIR_NAME = "uploads";
-
-	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 {
-		return createTempFile(DOWNLOAD_DIR_NAME);
-	}
-
-	@Override
-	public File createAndWriteTempFileForUpload(ContactId contactId,
-			OutgoingSessionRecord sessionRecord) throws IOException {
-		File f = createTempFile(UPLOAD_DIR_NAME);
-		// 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());
-		TransportConnectionWriter writer = plugin.createWriter(p);
-		if (writer == null) {
-			delete(f);
-			throw new IOException();
-		}
-		MailboxFileWriter decorated = new MailboxFileWriter(writer);
-		LOG.info("Writing file for upload");
-		connectionManager.manageOutgoingConnection(contactId, ID, decorated,
-				sessionRecord);
-		if (decorated.awaitDisposal()) {
-			// An exception was thrown during the session - delete the file
-			delete(f);
-			throw new IOException();
-		}
-		return f;
-	}
-
-	private File createTempFile(String dirName) throws IOException {
-		// Wait for orphaned files to be handled before creating new files
-		try {
-			orphanLatch.await();
-		} catch (InterruptedException e) {
-			throw new IOException(e);
-		}
-		File dir = createDirectoryIfNeeded(dirName);
-		return File.createTempFile("mailbox", ".tmp", dir);
-	}
-
-	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) {
-		// Wait for the transport to become active before handling orphaned
-		// files so that we can get the plugin from the plugin manager
-		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
-	 * delete any files that were left in the upload directory at the last
-	 * shutdown and handle any files that were left in the download directory.
-	 */
-	@IoExecutor
-	private void handleOrphanedFiles() {
-		try {
-			File uploadDir = createDirectoryIfNeeded(UPLOAD_DIR_NAME);
-			File[] orphanedUploads = uploadDir.listFiles();
-			if (orphanedUploads != null) {
-				for (File f : orphanedUploads) delete(f);
-			}
-			File downloadDir = createDirectoryIfNeeded(DOWNLOAD_DIR_NAME);
-			File[] orphanedDownloads = downloadDir.listFiles();
-			// Now that we've got the list of orphaned downloads, new files
-			// can be created in the download directory
-			orphanLatch.countDown();
-			if (orphanedDownloads != null) {
-				for (File f : orphanedDownloads) 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");
-				delete(file);
-			}
-		}
-	}
-
-	private static class MailboxFileWriter
-			implements TransportConnectionWriter {
-
-		private final TransportConnectionWriter delegate;
-		private final BlockingQueue<Boolean> disposalResult =
-				new ArrayBlockingQueue<>(1);
-
-		private MailboxFileWriter(TransportConnectionWriter delegate) {
-			this.delegate = delegate;
-		}
-
-		@Override
-		public long getMaxLatency() {
-			return delegate.getMaxLatency();
-		}
-
-		@Override
-		public int getMaxIdleTime() {
-			return delegate.getMaxIdleTime();
-		}
-
-		@Override
-		public boolean isLossyAndCheap() {
-			return delegate.isLossyAndCheap();
-		}
-
-		@Override
-		public OutputStream getOutputStream() throws IOException {
-			return delegate.getOutputStream();
-		}
-
-		@Override
-		public void dispose(boolean exception) throws IOException {
-			delegate.dispose(exception);
-			disposalResult.add(exception);
-		}
-
-		/**
-		 * Waits for the delegate to be disposed and returns true if an
-		 * exception occurred.
-		 */
-		private boolean awaitDisposal() {
-			try {
-				return disposalResult.take();
-			} catch (InterruptedException e) {
-				LOG.info("Interrupted while waiting for disposal");
-				return true;
-			}
-		}
-	}
-}

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

@@ -9,12 +9,10 @@ import org.briarproject.bramble.api.mailbox.MailboxPairingTask;
 import org.briarproject.bramble.api.mailbox.MailboxProperties;
 import org.briarproject.bramble.api.mailbox.MailboxSettingsManager;
 import org.briarproject.bramble.api.mailbox.MailboxStatus;
-import org.briarproject.bramble.api.mailbox.MailboxVersion;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.system.Clock;
 
 import java.io.IOException;
-import java.util.List;
 import java.util.concurrent.Executor;
 import java.util.logging.Logger;
 
@@ -100,60 +98,27 @@ class MailboxManagerImpl implements MailboxManager {
 
 	@Override
 	public boolean checkConnection() {
-		List<MailboxVersion> versions = null;
+		boolean success;
 		try {
 			MailboxProperties props = db.transactionWithNullableResult(true,
 					mailboxSettingsManager::getOwnMailboxProperties);
-			if (props == null) throw new DbException();
-			versions = api.getServerSupports(props);
-		} catch (DbException e) {
-			logException(LOG, WARNING, e);
-			// we don't treat this is a failure to record
-			return false;
-		} catch (IOException | MailboxApi.ApiException e) {
-			// we record this as a failure
+			success = api.checkStatus(props);
+		} catch (DbException | IOException | MailboxApi.ApiException e) {
+			success = false;
 			logException(LOG, WARNING, e);
 		}
-		try {
-			recordCheckResult(versions);
-		} catch (DbException e) {
-			logException(LOG, WARNING, e);
-		}
-		return versions != null;
-	}
-
-	private void recordCheckResult(@Nullable List<MailboxVersion> versions)
-			throws DbException {
-		long now = clock.currentTimeMillis();
-		db.transaction(false, txn -> {
-			if (versions != null) {
-				mailboxSettingsManager
-						.recordSuccessfulConnection(txn, now, versions);
-			} else {
-				mailboxSettingsManager.recordFailedConnectionAttempt(txn, now);
+		if (success) {
+			try {
+				// we are only recording successful connections here
+				// as those update the UI and failures might be false negatives
+				db.transaction(false, txn ->
+						mailboxSettingsManager.recordSuccessfulConnection(txn,
+								clock.currentTimeMillis()));
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
 			}
-		});
+		}
+		return success;
 	}
 
-	@Override
-	public boolean unPair() throws DbException {
-		MailboxProperties properties = db.transactionWithNullableResult(true,
-				mailboxSettingsManager::getOwnMailboxProperties);
-		if (properties == null) {
-			// no more mailbox, that's strange but possible if called in quick
-			// succession, so let's return true this time
-			return true;
-		}
-		boolean wasWiped;
-		try {
-			api.wipeMailbox(properties);
-			wasWiped = true;
-		} catch (IOException | MailboxApi.ApiException e) {
-			logException(LOG, WARNING, e);
-			wasWiped = false;
-		}
-		db.transaction(false,
-				mailboxSettingsManager::removeOwnMailboxProperties);
-		return wasWiped;
-	}
 }

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

@@ -1,42 +1,34 @@
 package org.briarproject.bramble.mailbox;
 
-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.MailboxPropertyManager;
 import org.briarproject.bramble.api.mailbox.MailboxSettingsManager;
-import org.briarproject.bramble.api.mailbox.MailboxUpdateManager;
-import org.briarproject.bramble.api.mailbox.MailboxVersion;
 import org.briarproject.bramble.api.sync.validation.ValidationManager;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.versioning.ClientVersioningManager;
 
-import java.util.List;
-
 import javax.inject.Inject;
 import javax.inject.Singleton;
 
 import dagger.Module;
 import dagger.Provides;
 
-import static org.briarproject.bramble.api.mailbox.MailboxConstants.CLIENT_SUPPORTS;
-import static org.briarproject.bramble.api.mailbox.MailboxUpdateManager.CLIENT_ID;
-import static org.briarproject.bramble.api.mailbox.MailboxUpdateManager.MAJOR_VERSION;
-import static org.briarproject.bramble.api.mailbox.MailboxUpdateManager.MINOR_VERSION;
+import static org.briarproject.bramble.api.mailbox.MailboxPropertyManager.CLIENT_ID;
+import static org.briarproject.bramble.api.mailbox.MailboxPropertyManager.MAJOR_VERSION;
+import static org.briarproject.bramble.api.mailbox.MailboxPropertyManager.MINOR_VERSION;
 
 @Module
 public class MailboxModule {
 
 	public static class EagerSingletons {
 		@Inject
-		MailboxUpdateValidator mailboxUpdateValidator;
+		MailboxPropertyValidator mailboxPropertyValidator;
 		@Inject
-		MailboxUpdateManager mailboxUpdateManager;
-		@Inject
-		MailboxFileManager mailboxFileManager;
+		MailboxPropertyManager mailboxPropertyManager;
 	}
 
 	@Provides
@@ -52,78 +44,43 @@ public class MailboxModule {
 	}
 
 	@Provides
-	@Singleton
 	MailboxSettingsManager provideMailboxSettingsManager(
 			MailboxSettingsManagerImpl mailboxSettingsManager) {
 		return mailboxSettingsManager;
 	}
 
 	@Provides
-	UrlConverter provideUrlConverter(UrlConverterImpl urlConverter) {
-		return urlConverter;
-	}
-
-	@Provides
-	MailboxApi provideMailboxApi(MailboxApiImpl mailboxApi) {
+	MailboxApi providesMailboxApi(MailboxApiImpl mailboxApi) {
 		return mailboxApi;
 	}
 
 	@Provides
 	@Singleton
-	MailboxUpdateValidator provideMailboxUpdateValidator(
-			ValidationManager validationManager,
-			ClientHelper clientHelper,
-			MetadataEncoder metadataEncoder,
-			Clock clock,
-			FeatureFlags featureFlags) {
-		MailboxUpdateValidator validator = new MailboxUpdateValidator(
+	MailboxPropertyValidator provideMailboxPropertyValidator(
+			ValidationManager validationManager, ClientHelper clientHelper,
+			MetadataEncoder metadataEncoder, Clock clock) {
+		MailboxPropertyValidator validator = new MailboxPropertyValidator(
 				clientHelper, metadataEncoder, clock);
-		if (featureFlags.shouldEnableMailbox()) {
-			validationManager.registerMessageValidator(CLIENT_ID,
-					MAJOR_VERSION, validator);
-		}
+		validationManager.registerMessageValidator(CLIENT_ID, MAJOR_VERSION,
+				validator);
 		return validator;
 	}
 
-	@Provides
-	List<MailboxVersion> provideClientSupports() {
-		return CLIENT_SUPPORTS;
-	}
-
 	@Provides
 	@Singleton
-	MailboxUpdateManager provideMailboxUpdateManager(
-			FeatureFlags featureFlags,
+	MailboxPropertyManager provideMailboxPropertyManager(
 			LifecycleManager lifecycleManager,
 			ValidationManager validationManager, ContactManager contactManager,
 			ClientVersioningManager clientVersioningManager,
 			MailboxSettingsManager mailboxSettingsManager,
-			MailboxUpdateManagerImpl mailboxUpdateManager) {
-		if (featureFlags.shouldEnableMailbox()) {
-			lifecycleManager.registerOpenDatabaseHook(mailboxUpdateManager);
-			validationManager.registerIncomingMessageHook(CLIENT_ID,
-					MAJOR_VERSION, mailboxUpdateManager);
-			contactManager.registerContactHook(mailboxUpdateManager);
-			clientVersioningManager.registerClient(CLIENT_ID, MAJOR_VERSION,
-					MINOR_VERSION, mailboxUpdateManager);
-			mailboxSettingsManager.registerMailboxHook(mailboxUpdateManager);
-		}
-		return mailboxUpdateManager;
-	}
-
-	@Provides
-	@Singleton
-	MailboxFileManager provideMailboxFileManager(FeatureFlags featureFlags,
-			EventBus eventBus, MailboxFileManagerImpl mailboxFileManager) {
-		if (featureFlags.shouldEnableMailbox()) {
-			eventBus.addListener(mailboxFileManager);
-		}
-		return mailboxFileManager;
-	}
-
-	@Provides
-	MailboxWorkerFactory provideMailboxWorkerFactory(
-			MailboxWorkerFactoryImpl mailboxWorkerFactory) {
-		return mailboxWorkerFactory;
+			MailboxPropertyManagerImpl mailboxPropertyManager) {
+		lifecycleManager.registerOpenDatabaseHook(mailboxPropertyManager);
+		validationManager.registerIncomingMessageHook(CLIENT_ID, MAJOR_VERSION,
+				mailboxPropertyManager);
+		contactManager.registerContactHook(mailboxPropertyManager);
+		clientVersioningManager.registerClient(CLIENT_ID, MAJOR_VERSION,
+				MINOR_VERSION, mailboxPropertyManager);
+		mailboxSettingsManager.registerMailboxHook(mailboxPropertyManager);
+		return mailboxPropertyManager;
 	}
 }

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

@@ -4,8 +4,8 @@ import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.event.EventExecutor;
 import org.briarproject.bramble.api.mailbox.MailboxPairingTask;
+import org.briarproject.bramble.api.mailbox.MailboxPropertyManager;
 import org.briarproject.bramble.api.mailbox.MailboxSettingsManager;
-import org.briarproject.bramble.api.mailbox.MailboxUpdateManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.system.Clock;
 
@@ -24,7 +24,7 @@ class MailboxPairingTaskFactoryImpl implements MailboxPairingTaskFactory {
 	private final Clock clock;
 	private final MailboxApi api;
 	private final MailboxSettingsManager mailboxSettingsManager;
-	private final MailboxUpdateManager mailboxUpdateManager;
+	private final MailboxPropertyManager mailboxPropertyManager;
 
 	@Inject
 	MailboxPairingTaskFactoryImpl(
@@ -34,20 +34,20 @@ class MailboxPairingTaskFactoryImpl implements MailboxPairingTaskFactory {
 			Clock clock,
 			MailboxApi api,
 			MailboxSettingsManager mailboxSettingsManager,
-			MailboxUpdateManager mailboxUpdateManager) {
+			MailboxPropertyManager mailboxPropertyManager) {
 		this.eventExecutor = eventExecutor;
 		this.db = db;
 		this.crypto = crypto;
 		this.clock = clock;
 		this.api = api;
 		this.mailboxSettingsManager = mailboxSettingsManager;
-		this.mailboxUpdateManager = mailboxUpdateManager;
+		this.mailboxPropertyManager = mailboxPropertyManager;
 	}
 
 	@Override
 	public MailboxPairingTask createPairingTask(String qrCodePayload) {
 		return new MailboxPairingTaskImpl(qrCodePayload, eventExecutor, db,
 				crypto, clock, api, mailboxSettingsManager,
-				mailboxUpdateManager);
+				mailboxPropertyManager);
 	}
 }

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

@@ -11,9 +11,9 @@ import org.briarproject.bramble.api.mailbox.MailboxAuthToken;
 import org.briarproject.bramble.api.mailbox.MailboxPairingState;
 import org.briarproject.bramble.api.mailbox.MailboxPairingTask;
 import org.briarproject.bramble.api.mailbox.MailboxProperties;
+import org.briarproject.bramble.api.mailbox.MailboxPropertiesUpdate;
+import org.briarproject.bramble.api.mailbox.MailboxPropertyManager;
 import org.briarproject.bramble.api.mailbox.MailboxSettingsManager;
-import org.briarproject.bramble.api.mailbox.MailboxUpdate;
-import org.briarproject.bramble.api.mailbox.MailboxUpdateManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.mailbox.MailboxApi.ApiException;
@@ -51,7 +51,7 @@ class MailboxPairingTaskImpl implements MailboxPairingTask {
 	private final Clock clock;
 	private final MailboxApi api;
 	private final MailboxSettingsManager mailboxSettingsManager;
-	private final MailboxUpdateManager mailboxUpdateManager;
+	private final MailboxPropertyManager mailboxPropertyManager;
 
 	private final Object lock = new Object();
 	@GuardedBy("lock")
@@ -68,7 +68,7 @@ class MailboxPairingTaskImpl implements MailboxPairingTask {
 			Clock clock,
 			MailboxApi api,
 			MailboxSettingsManager mailboxSettingsManager,
-			MailboxUpdateManager mailboxUpdateManager) {
+			MailboxPropertyManager mailboxPropertyManager) {
 		this.payload = payload;
 		this.eventExecutor = eventExecutor;
 		this.db = db;
@@ -76,7 +76,7 @@ class MailboxPairingTaskImpl implements MailboxPairingTask {
 		this.clock = clock;
 		this.api = api;
 		this.mailboxSettingsManager = mailboxSettingsManager;
-		this.mailboxUpdateManager = mailboxUpdateManager;
+		this.mailboxPropertyManager = mailboxPropertyManager;
 		state = new MailboxPairingState.QrCodeReceived();
 	}
 
@@ -125,9 +125,9 @@ class MailboxPairingTaskImpl implements MailboxPairingTask {
 			// timers for contacts who doesn't have their own mailbox. This way,
 			// data stranded on our old mailbox will be re-uploaded to our new.
 			for (Contact c : db.getContacts(txn)) {
-				MailboxUpdate update = mailboxUpdateManager.getRemoteUpdate(
-						txn, c.getId());
-				if (update == null || !update.hasMailbox()) {
+				MailboxPropertiesUpdate remoteProps = mailboxPropertyManager
+						.getRemoteProperties(txn, c.getId());
+				if (remoteProps == null) {
 					db.resetUnackedMessagesToSend(txn, c.getId());
 				}
 			}
@@ -177,9 +177,11 @@ class MailboxPairingTaskImpl implements MailboxPairingTask {
 		LOG.info("QR code is valid");
 		byte[] onionPubKey = Arrays.copyOfRange(bytes, 1, 33);
 		String onion = crypto.encodeOnion(onionPubKey);
+		String baseUrl = "http://" + onion + ".onion";
 		byte[] tokenBytes = Arrays.copyOfRange(bytes, 33, 65);
 		MailboxAuthToken setupToken = new MailboxAuthToken(tokenBytes);
-		return new MailboxProperties(onion, setupToken, new ArrayList<>());
+		return new MailboxProperties(baseUrl, setupToken, true,
+				new ArrayList<>());
 	}
 
 }

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

@@ -8,7 +8,6 @@ import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.ContactManager.ContactHook;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.data.BdfDictionary;
-import org.briarproject.bramble.api.data.BdfEntry;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.data.MetadataParser;
 import org.briarproject.bramble.api.db.DatabaseComponent;
@@ -19,13 +18,11 @@ import org.briarproject.bramble.api.lifecycle.LifecycleManager.OpenDatabaseHook;
 import org.briarproject.bramble.api.mailbox.MailboxAuthToken;
 import org.briarproject.bramble.api.mailbox.MailboxFolderId;
 import org.briarproject.bramble.api.mailbox.MailboxProperties;
+import org.briarproject.bramble.api.mailbox.MailboxPropertiesUpdate;
+import org.briarproject.bramble.api.mailbox.MailboxPropertyManager;
 import org.briarproject.bramble.api.mailbox.MailboxSettingsManager;
 import org.briarproject.bramble.api.mailbox.MailboxSettingsManager.MailboxHook;
-import org.briarproject.bramble.api.mailbox.MailboxUpdate;
-import org.briarproject.bramble.api.mailbox.MailboxUpdateManager;
-import org.briarproject.bramble.api.mailbox.MailboxUpdateWithMailbox;
-import org.briarproject.bramble.api.mailbox.MailboxVersion;
-import org.briarproject.bramble.api.mailbox.event.RemoteMailboxUpdateEvent;
+import org.briarproject.bramble.api.mailbox.RemoteMailboxPropertiesUpdateEvent;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.Group;
 import org.briarproject.bramble.api.sync.Group.Visibility;
@@ -38,7 +35,6 @@ import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.versioning.ClientVersioningManager;
 import org.briarproject.bramble.api.versioning.ClientVersioningManager.ClientVersioningHook;
 
-import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 
@@ -48,11 +44,10 @@ import javax.inject.Inject;
 import static org.briarproject.bramble.api.sync.validation.IncomingMessageHook.DeliveryAction.ACCEPT_DO_NOT_SHARE;
 
 @NotNullByDefault
-class MailboxUpdateManagerImpl implements MailboxUpdateManager,
+class MailboxPropertyManagerImpl implements MailboxPropertyManager,
 		OpenDatabaseHook, ContactHook, ClientVersioningHook,
 		IncomingMessageHook, MailboxHook {
 
-	private final List<MailboxVersion> clientSupports;
 	private final DatabaseComponent db;
 	private final ClientHelper clientHelper;
 	private final ClientVersioningManager clientVersioningManager;
@@ -64,14 +59,12 @@ class MailboxUpdateManagerImpl implements MailboxUpdateManager,
 	private final Group localGroup;
 
 	@Inject
-	MailboxUpdateManagerImpl(List<MailboxVersion> clientSupports,
-			DatabaseComponent db, ClientHelper clientHelper,
+	MailboxPropertyManagerImpl(DatabaseComponent db, ClientHelper clientHelper,
 			ClientVersioningManager clientVersioningManager,
 			MetadataParser metadataParser,
 			ContactGroupFactory contactGroupFactory, Clock clock,
 			MailboxSettingsManager mailboxSettingsManager,
 			CryptoComponent crypto) {
-		this.clientSupports = clientSupports;
 		this.db = db;
 		this.clientHelper = clientHelper;
 		this.clientVersioningManager = clientVersioningManager;
@@ -87,46 +80,12 @@ class MailboxUpdateManagerImpl implements MailboxUpdateManager,
 	@Override
 	public void onDatabaseOpened(Transaction txn) throws DbException {
 		if (db.containsGroup(txn, localGroup.getId())) {
-			try {
-				BdfDictionary meta = clientHelper.getGroupMetadataAsDictionary(
-						txn, localGroup.getId());
-				BdfList sent = meta.getList(GROUP_KEY_SENT_CLIENT_SUPPORTS);
-				if (clientHelper.parseMailboxVersionList(sent)
-						.equals(clientSupports)) {
-					return;
-				}
-			} catch (FormatException e) {
-				throw new DbException();
-			}
-			// Our current clientSupports list has changed compared to what we
-			// last sent out.
-			for (Contact c : db.getContacts(txn)) {
-				MailboxUpdate latest = getLocalUpdate(txn, c.getId());
-				MailboxUpdate updated;
-				if (latest.hasMailbox()) {
-					updated = new MailboxUpdateWithMailbox(
-							(MailboxUpdateWithMailbox) latest, clientSupports);
-				} else {
-					updated = new MailboxUpdate(clientSupports);
-				}
-				Group g = getContactGroup(c);
-				storeMessageReplaceLatest(txn, g.getId(), updated);
-			}
-		} else {
-			db.addGroup(txn, localGroup);
-			// Set things up for any pre-existing contacts
-			for (Contact c : db.getContacts(txn)) {
-				addingContact(txn, c);
-			}
+			return;
 		}
-
-		try {
-			BdfDictionary meta = BdfDictionary.of(new BdfEntry(
-					GROUP_KEY_SENT_CLIENT_SUPPORTS,
-					encodeSupportsList(clientSupports)));
-			clientHelper.mergeGroupMetadata(txn, localGroup.getId(), meta);
-		} catch (FormatException e) {
-			throw new DbException();
+		db.addGroup(txn, localGroup);
+		// Set things up for any pre-existing contacts
+		for (Contact c : db.getContacts(txn)) {
+			addingContact(txn, c);
 		}
 	}
 
@@ -141,15 +100,11 @@ class MailboxUpdateManagerImpl implements MailboxUpdateManager,
 		db.setGroupVisibility(txn, c.getId(), g.getId(), client);
 		// Attach the contact ID to the group
 		clientHelper.setContactId(txn, g.getId(), c.getId());
+		// If we are paired, create and send props to the newly added contact
 		MailboxProperties ownProps =
 				mailboxSettingsManager.getOwnMailboxProperties(txn);
 		if (ownProps != null) {
-			// We are paired, create and send props to the newly added contact
-			createAndSendUpdateWithMailbox(txn, c, ownProps.getServerSupports(),
-					ownProps.getOnion());
-		} else {
-			// Not paired, but we still want to get our clientSupports sent
-			sendUpdateNoMailbox(txn, c);
+			createAndSendProperties(txn, c, ownProps.getOnion());
 		}
 	}
 
@@ -159,17 +114,17 @@ class MailboxUpdateManagerImpl implements MailboxUpdateManager,
 	}
 
 	@Override
-	public void mailboxPaired(Transaction txn, String ownOnion,
-			List<MailboxVersion> serverSupports) throws DbException {
+	public void mailboxPaired(Transaction txn, String ownOnion)
+			throws DbException {
 		for (Contact c : db.getContacts(txn)) {
-			createAndSendUpdateWithMailbox(txn, c, serverSupports, ownOnion);
+			createAndSendProperties(txn, c, ownOnion);
 		}
 	}
 
 	@Override
 	public void mailboxUnpaired(Transaction txn) throws DbException {
 		for (Contact c : db.getContacts(txn)) {
-			sendUpdateNoMailbox(txn, c);
+			sendEmptyProperties(txn, c);
 		}
 	}
 
@@ -201,8 +156,8 @@ class MailboxUpdateManagerImpl implements MailboxUpdateManager,
 			}
 			ContactId c = clientHelper.getContactId(txn, m.getGroupId());
 			BdfList body = clientHelper.getMessageAsList(txn, m.getId());
-			MailboxUpdate u = parseUpdate(body);
-			txn.attach(new RemoteMailboxUpdateEvent(c, u));
+			MailboxPropertiesUpdate p = parseProperties(body);
+			txn.attach(new RemoteMailboxPropertiesUpdateEvent(c, p));
 			// Reset message retransmission timers for the contact. Avoiding
 			// messages getting stranded:
 			// - on our mailbox, if they now have a mailbox but didn't before
@@ -216,81 +171,70 @@ class MailboxUpdateManagerImpl implements MailboxUpdateManager,
 	}
 
 	@Override
-	public MailboxUpdate getLocalUpdate(Transaction txn, ContactId c)
-			throws DbException {
-		MailboxUpdate local = getUpdate(txn, db.getContact(txn, c), true);
-		// An update (with or without mailbox) is created when contact is added
-		if (local == null) {
-			throw new DbException();
-		}
-		return local;
+	@Nullable
+	public MailboxPropertiesUpdate getLocalProperties(Transaction txn,
+			ContactId c) throws DbException {
+		return getProperties(txn, db.getContact(txn, c), true);
 	}
 
 	@Override
 	@Nullable
-	public MailboxUpdate getRemoteUpdate(Transaction txn, ContactId c)
-			throws DbException {
-		return getUpdate(txn, db.getContact(txn, c), false);
+	public MailboxPropertiesUpdate getRemoteProperties(Transaction txn,
+			ContactId c) throws DbException {
+		return getProperties(txn, db.getContact(txn, c), false);
 	}
 
 	/**
 	 * Creates and sends an update message to the given contact. The message
-	 * holds our own mailbox's onion, generated unique properties, and lists of
-	 * supported Mailbox API version(s). All of which the contact needs to
-	 * communicate with our Mailbox.
+	 * holds our own mailbox's onion, and generated unique properties. All of
+	 * which the contact needs to communicate with our Mailbox.
 	 */
-	private void createAndSendUpdateWithMailbox(Transaction txn, Contact c,
-			List<MailboxVersion> serverSupports, String ownOnion)
-			throws DbException {
-		MailboxProperties properties = new MailboxProperties(ownOnion,
+	private void createAndSendProperties(Transaction txn,
+			Contact c, String ownOnion) throws DbException {
+		MailboxPropertiesUpdate p = new MailboxPropertiesUpdate(ownOnion,
 				new MailboxAuthToken(crypto.generateUniqueId().getBytes()),
-				serverSupports,
 				new MailboxFolderId(crypto.generateUniqueId().getBytes()),
 				new MailboxFolderId(crypto.generateUniqueId().getBytes()));
-		MailboxUpdate u =
-				new MailboxUpdateWithMailbox(clientSupports, properties);
 		Group g = getContactGroup(c);
-		storeMessageReplaceLatest(txn, g.getId(), u);
+		storeMessageReplaceLatest(txn, g.getId(), p);
 	}
 
 	/**
-	 * Sends an update message with empty properties to the given contact. The
-	 * empty update indicates for the receiving contact that we don't have any
-	 * Mailbox that they can use. It still includes the list of Mailbox API
-	 * version(s) that we support as a client.
+	 * Sends an empty update message to the given contact. The empty update
+	 * indicates for the receiving contact that we no longer have a Mailbox that
+	 * they can use.
 	 */
-	private void sendUpdateNoMailbox(Transaction txn, Contact c)
+	private void sendEmptyProperties(Transaction txn, Contact c)
 			throws DbException {
 		Group g = getContactGroup(c);
-		MailboxUpdate u = new MailboxUpdate(clientSupports);
-		storeMessageReplaceLatest(txn, g.getId(), u);
+		storeMessageReplaceLatest(txn, g.getId(), null);
 	}
 
 	@Nullable
-	private MailboxUpdate getUpdate(Transaction txn, Contact c, boolean local)
-			throws DbException {
-		MailboxUpdate u = null;
+	private MailboxPropertiesUpdate getProperties(Transaction txn,
+			Contact c, boolean local) throws DbException {
+		MailboxPropertiesUpdate p = null;
 		Group g = getContactGroup(c);
 		try {
 			LatestUpdate latest = findLatest(txn, g.getId(), local);
 			if (latest != null) {
 				BdfList body =
 						clientHelper.getMessageAsList(txn, latest.messageId);
-				u = parseUpdate(body);
+				p = parseProperties(body);
 			}
 		} catch (FormatException e) {
 			throw new DbException(e);
 		}
-		return u;
+		return p;
 	}
 
 	private void storeMessageReplaceLatest(Transaction txn, GroupId g,
-			MailboxUpdate u) throws DbException {
+			@Nullable MailboxPropertiesUpdate p) throws DbException {
 		try {
 			LatestUpdate latest = findLatest(txn, g, true);
 			long version = latest == null ? 1 : latest.version + 1;
 			Message m = clientHelper.createMessage(g, clock.currentTimeMillis(),
-					encodeProperties(version, u));
+					encodeProperties(version, p));
 			BdfDictionary meta = new BdfDictionary();
 			meta.put(MSG_KEY_VERSION, version);
 			meta.put(MSG_KEY_LOCAL, true);
@@ -322,36 +266,23 @@ class MailboxUpdateManagerImpl implements MailboxUpdateManager,
 		return null;
 	}
 
-	private BdfList encodeProperties(long version, MailboxUpdate u) {
+	private BdfList encodeProperties(long version,
+			@Nullable MailboxPropertiesUpdate p) {
 		BdfDictionary dict = new BdfDictionary();
-		BdfList serverSupports = new BdfList();
-		if (u.hasMailbox()) {
-			MailboxUpdateWithMailbox um = (MailboxUpdateWithMailbox) u;
-			MailboxProperties properties = um.getMailboxProperties();
-			serverSupports = encodeSupportsList(properties.getServerSupports());
-			dict.put(PROP_KEY_ONION, properties.getOnion());
-			dict.put(PROP_KEY_AUTHTOKEN, properties.getAuthToken());
-			dict.put(PROP_KEY_INBOXID, properties.getInboxId());
-			dict.put(PROP_KEY_OUTBOXID, properties.getOutboxId());
+		if (p != null) {
+			dict.put(PROP_KEY_ONION, p.getOnion());
+			dict.put(PROP_KEY_AUTHTOKEN, p.getAuthToken().getBytes());
+			dict.put(PROP_KEY_INBOXID, p.getInboxId().getBytes());
+			dict.put(PROP_KEY_OUTBOXID, p.getOutboxId().getBytes());
 		}
-		return BdfList.of(version, encodeSupportsList(u.getClientSupports()),
-				serverSupports, dict);
+		return BdfList.of(version, dict);
 	}
 
-	private BdfList encodeSupportsList(List<MailboxVersion> supportsList) {
-		BdfList supports = new BdfList();
-		for (MailboxVersion version : supportsList) {
-			supports.add(BdfList.of(version.getMajor(), version.getMinor()));
-		}
-		return supports;
-	}
-
-	private MailboxUpdate parseUpdate(BdfList body) throws FormatException {
-		BdfList clientSupports = body.getList(1);
-		BdfList serverSupports = body.getList(2);
-		BdfDictionary dict = body.getDictionary(3);
-		return clientHelper.parseAndValidateMailboxUpdate(clientSupports,
-				serverSupports, dict);
+	@Nullable
+	private MailboxPropertiesUpdate parseProperties(BdfList body)
+			throws FormatException {
+		BdfDictionary dict = body.getDictionary(1);
+		return clientHelper.parseAndValidateMailboxPropertiesUpdate(dict);
 	}
 
 	private Group getContactGroup(Contact c) {

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

@@ -15,15 +15,15 @@ import org.briarproject.bramble.api.system.Clock;
 
 import javax.annotation.concurrent.Immutable;
 
-import static org.briarproject.bramble.api.mailbox.MailboxUpdateManager.MSG_KEY_LOCAL;
-import static org.briarproject.bramble.api.mailbox.MailboxUpdateManager.MSG_KEY_VERSION;
+import static org.briarproject.bramble.api.mailbox.MailboxPropertyManager.MSG_KEY_LOCAL;
+import static org.briarproject.bramble.api.mailbox.MailboxPropertyManager.MSG_KEY_VERSION;
 import static org.briarproject.bramble.util.ValidationUtils.checkSize;
 
 @Immutable
 @NotNullByDefault
-class MailboxUpdateValidator extends BdfMessageValidator {
+class MailboxPropertyValidator extends BdfMessageValidator {
 
-	MailboxUpdateValidator(ClientHelper clientHelper,
+	MailboxPropertyValidator(ClientHelper clientHelper,
 			MetadataEncoder metadataEncoder, Clock clock) {
 		super(clientHelper, metadataEncoder, clock);
 	}
@@ -31,19 +31,14 @@ class MailboxUpdateValidator extends BdfMessageValidator {
 	@Override
 	protected BdfMessageContext validateMessage(Message m, Group g,
 			BdfList body) throws InvalidMessageException, FormatException {
-		// Version, Properties, clientSupports, serverSupports
-		checkSize(body, 4);
+		// Version, properties
+		checkSize(body, 2);
 		// Version
 		long version = body.getLong(0);
 		if (version < 0) throw new FormatException();
-		// clientSupports
-		BdfList clientSupports = body.getList(1);
-		// serverSupports
-		BdfList serverSupports = body.getList(2);
 		// Properties
-		BdfDictionary dictionary = body.getDictionary(3);
-		clientHelper.parseAndValidateMailboxUpdate(clientSupports,
-				serverSupports, dictionary);
+		BdfDictionary dictionary = body.getDictionary(1);
+		clientHelper.parseAndValidateMailboxPropertiesUpdate(dictionary);
 		// Return the metadata
 		BdfDictionary meta = new BdfDictionary();
 		meta.put(MSG_KEY_VERSION, version);

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

@@ -9,8 +9,7 @@ import org.briarproject.bramble.api.mailbox.MailboxProperties;
 import org.briarproject.bramble.api.mailbox.MailboxSettingsManager;
 import org.briarproject.bramble.api.mailbox.MailboxStatus;
 import org.briarproject.bramble.api.mailbox.MailboxVersion;
-import org.briarproject.bramble.api.mailbox.event.MailboxProblemEvent;
-import org.briarproject.bramble.api.mailbox.event.OwnMailboxConnectionStatusEvent;
+import org.briarproject.bramble.api.mailbox.OwnMailboxConnectionStatusEvent;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.settings.Settings;
 import org.briarproject.bramble.api.settings.SettingsManager;
@@ -20,19 +19,17 @@ import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;
 
 import javax.annotation.Nullable;
-import javax.annotation.concurrent.ThreadSafe;
+import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
-import static java.util.Collections.emptyList;
 import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
 
-@ThreadSafe
+@Immutable
 @NotNullByDefault
 class MailboxSettingsManagerImpl implements MailboxSettingsManager {
 
 	// Package access for testing
 	static final String SETTINGS_NAMESPACE = "mailbox";
-	// TODO: This currently stores the base URL, not the 56-char onion address
 	static final String SETTINGS_KEY_ONION = "onion";
 	static final String SETTINGS_KEY_TOKEN = "token";
 	static final String SETTINGS_KEY_SERVER_SUPPORTS = "serverSupports";
@@ -61,10 +58,19 @@ class MailboxSettingsManagerImpl implements MailboxSettingsManager {
 		String onion = s.get(SETTINGS_KEY_ONION);
 		String token = s.get(SETTINGS_KEY_TOKEN);
 		if (isNullOrEmpty(onion) || isNullOrEmpty(token)) return null;
-		List<MailboxVersion> serverSupports = parseServerSupports(s);
+		int[] ints = s.getIntArray(SETTINGS_KEY_SERVER_SUPPORTS);
+		// We know we were paired, so we must have proper serverSupports
+		// TODO is throwing sensible? But it's done like that below on "parse error"
+		if (ints == null || ints.length == 0 || ints.length % 2 != 0) {
+			throw new DbException();
+		}
+		List<MailboxVersion> serverSupports = new ArrayList<>();
+		for (int i = 0; i < ints.length - 1; i += 2) {
+			serverSupports.add(new MailboxVersion(ints[i], ints[i + 1]));
+		}
 		try {
 			MailboxAuthToken tokenId = MailboxAuthToken.fromString(token);
-			return new MailboxProperties(onion, tokenId, serverSupports);
+			return new MailboxProperties(onion, tokenId, true, serverSupports);
 		} catch (InvalidMailboxIdException e) {
 			throw new DbException(e);
 		}
@@ -74,24 +80,19 @@ class MailboxSettingsManagerImpl implements MailboxSettingsManager {
 	public void setOwnMailboxProperties(Transaction txn, MailboxProperties p)
 			throws DbException {
 		Settings s = new Settings();
-		s.put(SETTINGS_KEY_ONION, p.getOnion());
+		s.put(SETTINGS_KEY_ONION, p.getBaseUrl());
 		s.put(SETTINGS_KEY_TOKEN, p.getAuthToken().toString());
 		List<MailboxVersion> serverSupports = p.getServerSupports();
-		encodeServerSupports(serverSupports, s);
-		settingsManager.mergeSettings(txn, s, SETTINGS_NAMESPACE);
-		for (MailboxHook hook : hooks) {
-			hook.mailboxPaired(txn, p.getOnion(), p.getServerSupports());
+		int[] ints = new int[serverSupports.size() * 2];
+		int i = 0;
+		for (MailboxVersion v : serverSupports) {
+			ints[i++] = v.getMajor();
+			ints[i++] = v.getMinor();
 		}
-	}
-
-	@Override
-	public void removeOwnMailboxProperties(Transaction txn) throws DbException {
-		Settings s = new Settings();
-		s.put(SETTINGS_KEY_ONION, "");
-		s.put(SETTINGS_KEY_TOKEN, "");
+		s.putIntArray(SETTINGS_KEY_SERVER_SUPPORTS, ints);
 		settingsManager.mergeSettings(txn, s, SETTINGS_NAMESPACE);
 		for (MailboxHook hook : hooks) {
-			hook.mailboxUnpaired(txn);
+			hook.mailboxPaired(txn, p.getOnion());
 		}
 	}
 
@@ -102,44 +103,18 @@ class MailboxSettingsManagerImpl implements MailboxSettingsManager {
 		long lastAttempt = s.getLong(SETTINGS_KEY_LAST_ATTEMPT, -1);
 		long lastSuccess = s.getLong(SETTINGS_KEY_LAST_SUCCESS, -1);
 		int attempts = s.getInt(SETTINGS_KEY_ATTEMPTS, 0);
-		List<MailboxVersion> serverSupports;
-		try {
-			serverSupports = parseServerSupports(s);
-		} catch (DbException e) {
-			serverSupports = emptyList();
-		}
-		return new MailboxStatus(lastAttempt, lastSuccess, attempts,
-				serverSupports);
+		return new MailboxStatus(lastAttempt, lastSuccess, attempts);
 	}
 
 	@Override
 	public void recordSuccessfulConnection(Transaction txn, long now)
 			throws DbException {
-		recordSuccessfulConnection(txn, now, null);
-	}
-
-	@Override
-	public void recordSuccessfulConnection(Transaction txn, long now,
-			@Nullable List<MailboxVersion> versions) throws DbException {
 		Settings s = new Settings();
-		// fetch version that the server supports first
-		List<MailboxVersion> serverSupports;
-		if (versions == null) {
-			Settings oldSettings =
-					settingsManager.getSettings(txn, SETTINGS_NAMESPACE);
-			serverSupports = parseServerSupports(oldSettings);
-		} else {
-			serverSupports = versions;
-			// store new versions
-			encodeServerSupports(serverSupports, s);
-		}
-		// now record the successful connection
 		s.putLong(SETTINGS_KEY_LAST_ATTEMPT, now);
 		s.putLong(SETTINGS_KEY_LAST_SUCCESS, now);
 		s.putInt(SETTINGS_KEY_ATTEMPTS, 0);
 		settingsManager.mergeSettings(txn, s, SETTINGS_NAMESPACE);
-		// broadcast status event
-		MailboxStatus status = new MailboxStatus(now, now, 0, serverSupports);
+		MailboxStatus status = new MailboxStatus(now, now, 0);
 		txn.attach(new OwnMailboxConnectionStatusEvent(status));
 	}
 
@@ -154,11 +129,8 @@ class MailboxSettingsManagerImpl implements MailboxSettingsManager {
 		newSettings.putLong(SETTINGS_KEY_LAST_ATTEMPT, now);
 		newSettings.putInt(SETTINGS_KEY_ATTEMPTS, newAttempts);
 		settingsManager.mergeSettings(txn, newSettings, SETTINGS_NAMESPACE);
-		List<MailboxVersion> serverSupports = parseServerSupports(oldSettings);
-		MailboxStatus status = new MailboxStatus(now, lastSuccess, newAttempts,
-				serverSupports);
+		MailboxStatus status = new MailboxStatus(now, lastSuccess, newAttempts);
 		txn.attach(new OwnMailboxConnectionStatusEvent(status));
-		if (status.hasProblem(now)) txn.attach(new MailboxProblemEvent());
 	}
 
 	@Override
@@ -180,30 +152,4 @@ class MailboxSettingsManagerImpl implements MailboxSettingsManager {
 		if (isNullOrEmpty(filename)) return null;
 		return filename;
 	}
-
-	private void encodeServerSupports(List<MailboxVersion> serverSupports,
-			Settings s) {
-		int[] ints = new int[serverSupports.size() * 2];
-		int i = 0;
-		for (MailboxVersion v : serverSupports) {
-			ints[i++] = v.getMajor();
-			ints[i++] = v.getMinor();
-		}
-		s.putIntArray(SETTINGS_KEY_SERVER_SUPPORTS, ints);
-	}
-
-	private List<MailboxVersion> parseServerSupports(Settings s)
-			throws DbException {
-		if (!s.containsKey(SETTINGS_KEY_SERVER_SUPPORTS)) return emptyList();
-		int[] ints = s.getIntArray(SETTINGS_KEY_SERVER_SUPPORTS);
-		// We know we were paired, so we must have proper serverSupports
-		if (ints == null || ints.length == 0 || ints.length % 2 != 0) {
-			throw new DbException();
-		}
-		List<MailboxVersion> serverSupports = new ArrayList<>();
-		for (int i = 0; i < ints.length - 1; i += 2) {
-			serverSupports.add(new MailboxVersion(ints[i], ints[i + 1]));
-		}
-		return serverSupports;
-	}
 }

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

@@ -1,394 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.Cancellable;
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.db.DatabaseComponent;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.event.EventBus;
-import org.briarproject.bramble.api.event.EventExecutor;
-import org.briarproject.bramble.api.event.EventListener;
-import org.briarproject.bramble.api.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.mailbox.MailboxFolderId;
-import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.bramble.api.sync.OutgoingSessionRecord;
-import org.briarproject.bramble.api.sync.event.GroupVisibilityUpdatedEvent;
-import org.briarproject.bramble.api.sync.event.MessageSharedEvent;
-import org.briarproject.bramble.api.sync.event.MessageToAckEvent;
-import org.briarproject.bramble.api.system.Clock;
-import org.briarproject.bramble.api.system.TaskScheduler;
-import org.briarproject.bramble.mailbox.ConnectivityChecker.ConnectivityObserver;
-import org.briarproject.bramble.mailbox.MailboxApi.ApiException;
-
-import java.io.File;
-import java.io.IOException;
-import java.util.Collection;
-import java.util.concurrent.Executor;
-import java.util.logging.Logger;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.GuardedBy;
-import javax.annotation.concurrent.ThreadSafe;
-
-import static java.util.concurrent.TimeUnit.MILLISECONDS;
-import static java.util.concurrent.TimeUnit.MINUTES;
-import static java.util.logging.Level.INFO;
-import static java.util.logging.Level.WARNING;
-import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.api.mailbox.MailboxConstants.MAX_LATENCY;
-import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
-import static org.briarproject.bramble.util.IoUtils.delete;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@ThreadSafe
-@NotNullByDefault
-class MailboxUploadWorker implements MailboxWorker, ConnectivityObserver,
-		EventListener {
-
-	/**
-	 * When the worker is started it checks for data to send. If data is ready
-	 * to send, the worker waits for a connectivity check, then writes and
-	 * uploads a file and checks again for data to send.
-	 * <p>
-	 * If data is due to be sent at some time in the future, the worker
-	 * schedules a wakeup for that time and also listens for events indicating
-	 * that new data may be ready to send.
-	 * <p>
-	 * If there's no data to send, the worker listens for events indicating
-	 * that new data may be ready to send.
-	 */
-	private enum State {
-		CREATED,
-		CHECKING_FOR_DATA,
-		WAITING_FOR_DATA,
-		CONNECTIVITY_CHECK,
-		WRITING_UPLOADING,
-		DESTROYED
-	}
-
-	private static final Logger LOG =
-			getLogger(MailboxUploadWorker.class.getName());
-
-	/**
-	 * When we're waiting for data to send and an event indicates that new data
-	 * may have become available, wait this long before checking the DB. This
-	 * should help to avoid creating lots of small files when several acks or
-	 * messages become available to send in a short period (eg when reading a
-	 * file downloaded from a mailbox).
-	 * <p>
-	 * Package access for testing.
-	 */
-	static final long CHECK_DELAY_MS = 5_000;
-
-	/**
-	 * How long to wait before retrying when an exception occurs while writing
-	 * a file.
-	 * <p>
-	 * Package access for testing.
-	 */
-	static final long RETRY_DELAY_MS = MINUTES.toMillis(1);
-
-	private final Executor ioExecutor;
-	private final DatabaseComponent db;
-	private final Clock clock;
-	private final TaskScheduler taskScheduler;
-	private final EventBus eventBus;
-	private final ConnectivityChecker connectivityChecker;
-	private final MailboxApiCaller mailboxApiCaller;
-	private final MailboxApi mailboxApi;
-	private final MailboxFileManager mailboxFileManager;
-	private final MailboxProperties mailboxProperties;
-	private final MailboxFolderId folderId;
-	private final ContactId contactId;
-
-	private final Object lock = new Object();
-
-	@GuardedBy("lock")
-	private State state = State.CREATED;
-
-	@GuardedBy("lock")
-	@Nullable
-	private Cancellable wakeupTask = null, checkTask = null, apiCall = null;
-
-	@GuardedBy("lock")
-	@Nullable
-	private File file = null;
-
-	MailboxUploadWorker(@IoExecutor Executor ioExecutor,
-			DatabaseComponent db,
-			Clock clock,
-			TaskScheduler taskScheduler,
-			EventBus eventBus,
-			ConnectivityChecker connectivityChecker,
-			MailboxApiCaller mailboxApiCaller,
-			MailboxApi mailboxApi,
-			MailboxFileManager mailboxFileManager,
-			MailboxProperties mailboxProperties,
-			MailboxFolderId folderId,
-			ContactId contactId) {
-		this.ioExecutor = ioExecutor;
-		this.db = db;
-		this.clock = clock;
-		this.taskScheduler = taskScheduler;
-		this.eventBus = eventBus;
-		this.connectivityChecker = connectivityChecker;
-		this.mailboxApiCaller = mailboxApiCaller;
-		this.mailboxApi = mailboxApi;
-		this.mailboxFileManager = mailboxFileManager;
-		this.mailboxProperties = mailboxProperties;
-		this.folderId = folderId;
-		this.contactId = contactId;
-	}
-
-	@Override
-	public void start() {
-		LOG.info("Started");
-		synchronized (lock) {
-			// Don't allow the worker to be reused
-			if (state != State.CREATED) return;
-			state = State.CHECKING_FOR_DATA;
-		}
-		ioExecutor.execute(this::checkForDataToSend);
-	}
-
-	@Override
-	public void destroy() {
-		LOG.info("Destroyed");
-		Cancellable wakeupTask, checkTask, apiCall;
-		File file;
-		synchronized (lock) {
-			state = State.DESTROYED;
-			wakeupTask = this.wakeupTask;
-			this.wakeupTask = null;
-			checkTask = this.checkTask;
-			this.checkTask = null;
-			apiCall = this.apiCall;
-			this.apiCall = null;
-			file = this.file;
-			this.file = null;
-		}
-		if (wakeupTask != null) wakeupTask.cancel();
-		if (checkTask != null) checkTask.cancel();
-		if (apiCall != null) apiCall.cancel();
-		if (file != null) delete(file);
-		connectivityChecker.removeObserver(this);
-		eventBus.removeListener(this);
-	}
-
-	@IoExecutor
-	private void checkForDataToSend() {
-		synchronized (lock) {
-			checkTask = null;
-			if (state != State.CHECKING_FOR_DATA) return;
-		}
-		LOG.info("Checking for data to send");
-		try {
-			db.transaction(true, txn -> {
-				long nextSendTime;
-				if (db.containsAcksToSend(txn, contactId)) {
-					nextSendTime = 0L;
-				} else {
-					nextSendTime = db.getNextSendTime(txn, contactId,
-							MAX_LATENCY);
-				}
-				// Handle the result on the event executor to avoid races with
-				// incoming events
-				txn.attach(() -> handleNextSendTime(nextSendTime));
-			});
-		} catch (DbException e) {
-			logException(LOG, WARNING, e);
-		}
-	}
-
-	@EventExecutor
-	private void handleNextSendTime(long nextSendTime) {
-		if (nextSendTime == Long.MAX_VALUE) {
-			// Nothing is sendable now or due to be sent in the future. Wait
-			// for an event indicating that new data may be ready to send
-			waitForDataToSend();
-		} else {
-			// Work out the delay until data's ready to send (may be negative)
-			long delay = nextSendTime - clock.currentTimeMillis();
-			if (delay > 0) {
-				// Schedule a wakeup when data will be ready to send. If an
-				// event is received in the meantime indicating that new data
-				// may be ready to send, we'll cancel the wakeup
-				scheduleWakeup(delay);
-			} else {
-				// Data is ready to send now
-				checkConnectivity();
-			}
-		}
-	}
-
-	@EventExecutor
-	private void waitForDataToSend() {
-		synchronized (lock) {
-			if (state != State.CHECKING_FOR_DATA) return;
-			state = State.WAITING_FOR_DATA;
-			LOG.info("Waiting for data to send");
-		}
-	}
-
-	@EventExecutor
-	private void scheduleWakeup(long delay) {
-		synchronized (lock) {
-			if (state != State.CHECKING_FOR_DATA) return;
-			state = State.WAITING_FOR_DATA;
-			if (LOG.isLoggable(INFO)) {
-				LOG.info("Scheduling wakeup in " + delay + " ms");
-			}
-			wakeupTask = taskScheduler.schedule(this::wakeUp, ioExecutor,
-					delay, MILLISECONDS);
-		}
-	}
-
-	@IoExecutor
-	private void wakeUp() {
-		LOG.info("Woke up");
-		synchronized (lock) {
-			wakeupTask = null;
-			if (state != State.WAITING_FOR_DATA) return;
-			state = State.CHECKING_FOR_DATA;
-		}
-		checkForDataToSend();
-	}
-
-	@EventExecutor
-	private void checkConnectivity() {
-		synchronized (lock) {
-			if (state != State.CHECKING_FOR_DATA) return;
-			state = State.CONNECTIVITY_CHECK;
-		}
-		LOG.info("Checking connectivity");
-		// Avoid leaking observer in case destroy() is called concurrently
-		// before observer is added
-		connectivityChecker.checkConnectivity(mailboxProperties, this);
-		boolean destroyed;
-		synchronized (lock) {
-			destroyed = state == State.DESTROYED;
-		}
-		if (destroyed) connectivityChecker.removeObserver(this);
-	}
-
-	@Override
-	public void onConnectivityCheckSucceeded() {
-		LOG.info("Connectivity check succeeded");
-		synchronized (lock) {
-			if (state != State.CONNECTIVITY_CHECK) return;
-			state = State.WRITING_UPLOADING;
-		}
-		ioExecutor.execute(this::writeAndUploadFile);
-	}
-
-	@IoExecutor
-	private void writeAndUploadFile() {
-		synchronized (lock) {
-			if (state != State.WRITING_UPLOADING) return;
-		}
-		OutgoingSessionRecord sessionRecord = new OutgoingSessionRecord();
-		File file;
-		try {
-			file = mailboxFileManager.createAndWriteTempFileForUpload(
-					contactId, sessionRecord);
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-			// Try again after a delay
-			synchronized (lock) {
-				if (state != State.WRITING_UPLOADING) return;
-				state = State.CHECKING_FOR_DATA;
-				checkTask = taskScheduler.schedule(this::checkForDataToSend,
-						ioExecutor, RETRY_DELAY_MS, MILLISECONDS);
-			}
-			return;
-		}
-		boolean deleteFile = false;
-		synchronized (lock) {
-			if (state == State.WRITING_UPLOADING) {
-				this.file = file;
-				apiCall = mailboxApiCaller.retryWithBackoff(
-						new SimpleApiCall(() -> apiCallUploadFile(file,
-								sessionRecord)));
-			} else {
-				deleteFile = true;
-			}
-		}
-		if (deleteFile) delete(file);
-	}
-
-	@IoExecutor
-	private void apiCallUploadFile(File file,
-			OutgoingSessionRecord sessionRecord)
-			throws IOException, ApiException {
-		synchronized (lock) {
-			if (state != State.WRITING_UPLOADING) return;
-		}
-		LOG.info("Uploading file");
-		mailboxApi.addFile(mailboxProperties, folderId, file);
-		markMessagesSentOrAcked(sessionRecord);
-		synchronized (lock) {
-			if (state != State.WRITING_UPLOADING) return;
-			state = State.CHECKING_FOR_DATA;
-			apiCall = null;
-			this.file = null;
-		}
-		delete(file);
-		checkForDataToSend();
-	}
-
-	private void markMessagesSentOrAcked(OutgoingSessionRecord sessionRecord) {
-		Collection<MessageId> acked = sessionRecord.getAckedIds();
-		Collection<MessageId> sent = sessionRecord.getSentIds();
-		try {
-			db.transaction(false, txn -> {
-				if (!acked.isEmpty()) {
-					db.setAckSent(txn, contactId, acked);
-				}
-				if (!sent.isEmpty()) {
-					db.setMessagesSent(txn, contactId, sent, MAX_LATENCY);
-				}
-			});
-		} catch (DbException e) {
-			logException(LOG, WARNING, e);
-		}
-	}
-
-	@Override
-	public void eventOccurred(Event e) {
-		if (e instanceof MessageToAckEvent) {
-			MessageToAckEvent m = (MessageToAckEvent) e;
-			if (m.getContactId().equals(contactId)) {
-				LOG.info("Message to ack");
-				onDataToSend();
-			}
-		} else if (e instanceof MessageSharedEvent) {
-			LOG.info("Message shared");
-			onDataToSend();
-		} else if (e instanceof GroupVisibilityUpdatedEvent) {
-			GroupVisibilityUpdatedEvent g = (GroupVisibilityUpdatedEvent) e;
-			if (g.getVisibility() == SHARED &&
-					g.getAffectedContacts().contains(contactId)) {
-				LOG.info("Group shared");
-				onDataToSend();
-			}
-		}
-	}
-
-	@EventExecutor
-	private void onDataToSend() {
-		Cancellable wakeupTask;
-		synchronized (lock) {
-			if (state != State.WAITING_FOR_DATA) return;
-			state = State.CHECKING_FOR_DATA;
-			wakeupTask = this.wakeupTask;
-			this.wakeupTask = null;
-			// Delay the check to avoid creating lots of small files
-			checkTask = taskScheduler.schedule(this::checkForDataToSend,
-					ioExecutor, CHECK_DELAY_MS, MILLISECONDS);
-		}
-		// If we had scheduled a wakeup when data was due to be sent, cancel it
-		if (wakeupTask != null) wakeupTask.cancel();
-	}
-}

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

@@ -1,23 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.ThreadSafe;
-
-/**
- * A worker that downloads files from a contact's mailbox.
- */
-@ThreadSafe
-@NotNullByDefault
-interface MailboxWorker {
-
-	/**
-	 * Asynchronously starts the worker.
-	 */
-	void start();
-
-	/**
-	 * Destroys the worker and cancels any pending tasks or retries.
-	 */
-	void destroy();
-}

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

@@ -1,27 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.mailbox.MailboxFolderId;
-import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.ThreadSafe;
-
-@ThreadSafe
-@NotNullByDefault
-interface MailboxWorkerFactory {
-
-	MailboxWorker createUploadWorker(ConnectivityChecker connectivityChecker,
-			MailboxProperties properties, MailboxFolderId folderId,
-			ContactId contactId);
-
-	MailboxWorker createDownloadWorkerForContactMailbox(
-			ConnectivityChecker connectivityChecker,
-			TorReachabilityMonitor reachabilityMonitor,
-			MailboxProperties properties);
-
-	MailboxWorker createDownloadWorkerForOwnMailbox(
-			ConnectivityChecker connectivityChecker,
-			TorReachabilityMonitor reachabilityMonitor,
-			MailboxProperties properties);
-}

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

@@ -1,81 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.db.DatabaseComponent;
-import org.briarproject.bramble.api.event.EventBus;
-import org.briarproject.bramble.api.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.mailbox.MailboxFolderId;
-import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.system.Clock;
-import org.briarproject.bramble.api.system.TaskScheduler;
-
-import java.util.concurrent.Executor;
-
-import javax.annotation.concurrent.Immutable;
-import javax.inject.Inject;
-
-@Immutable
-@NotNullByDefault
-class MailboxWorkerFactoryImpl implements MailboxWorkerFactory {
-
-	private final Executor ioExecutor;
-	private final DatabaseComponent db;
-	private final Clock clock;
-	private final TaskScheduler taskScheduler;
-	private final EventBus eventBus;
-	private final MailboxApiCaller mailboxApiCaller;
-	private final MailboxApi mailboxApi;
-	private final MailboxFileManager mailboxFileManager;
-
-	@Inject
-	MailboxWorkerFactoryImpl(@IoExecutor Executor ioExecutor,
-			DatabaseComponent db,
-			Clock clock,
-			TaskScheduler taskScheduler,
-			EventBus eventBus,
-			MailboxApiCaller mailboxApiCaller,
-			MailboxApi mailboxApi,
-			MailboxFileManager mailboxFileManager) {
-		this.ioExecutor = ioExecutor;
-		this.db = db;
-		this.clock = clock;
-		this.taskScheduler = taskScheduler;
-		this.eventBus = eventBus;
-		this.mailboxApiCaller = mailboxApiCaller;
-		this.mailboxApi = mailboxApi;
-		this.mailboxFileManager = mailboxFileManager;
-	}
-
-	@Override
-	public MailboxWorker createUploadWorker(
-			ConnectivityChecker connectivityChecker,
-			MailboxProperties properties, MailboxFolderId folderId,
-			ContactId contactId) {
-		MailboxUploadWorker worker = new MailboxUploadWorker(ioExecutor, db,
-				clock, taskScheduler, eventBus, connectivityChecker,
-				mailboxApiCaller, mailboxApi, mailboxFileManager,
-				properties, folderId, contactId);
-		eventBus.addListener(worker);
-		return worker;
-	}
-
-	@Override
-	public MailboxWorker createDownloadWorkerForContactMailbox(
-			ConnectivityChecker connectivityChecker,
-			TorReachabilityMonitor reachabilityMonitor,
-			MailboxProperties properties) {
-		return new ContactMailboxDownloadWorker(connectivityChecker,
-				reachabilityMonitor, mailboxApiCaller, mailboxApi,
-				mailboxFileManager, properties);
-	}
-
-	@Override
-	public MailboxWorker createDownloadWorkerForOwnMailbox(
-			ConnectivityChecker connectivityChecker,
-			TorReachabilityMonitor reachabilityMonitor,
-			MailboxProperties properties) {
-		// TODO
-		throw new UnsupportedOperationException();
-	}
-}

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

@@ -1,78 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.db.TransactionManager;
-import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.mailbox.MailboxSettingsManager;
-import org.briarproject.bramble.api.mailbox.MailboxVersion;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.system.Clock;
-import org.briarproject.bramble.mailbox.MailboxApi.ApiException;
-
-import java.io.IOException;
-import java.util.List;
-import java.util.logging.Logger;
-
-import javax.annotation.concurrent.ThreadSafe;
-
-import static java.util.logging.Level.WARNING;
-import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@ThreadSafe
-@NotNullByDefault
-class OwnMailboxConnectivityChecker extends ConnectivityCheckerImpl {
-
-	private static final Logger LOG =
-			getLogger(OwnMailboxConnectivityChecker.class.getName());
-
-	private final MailboxApi mailboxApi;
-	private final TransactionManager db;
-	private final MailboxSettingsManager mailboxSettingsManager;
-
-	OwnMailboxConnectivityChecker(Clock clock,
-			MailboxApiCaller mailboxApiCaller,
-			MailboxApi mailboxApi,
-			TransactionManager db,
-			MailboxSettingsManager mailboxSettingsManager) {
-		super(clock, mailboxApiCaller);
-		this.mailboxApi = mailboxApi;
-		this.db = db;
-		this.mailboxSettingsManager = mailboxSettingsManager;
-	}
-
-	@Override
-	ApiCall createConnectivityCheckTask(MailboxProperties properties) {
-		if (!properties.isOwner()) throw new IllegalArgumentException();
-		return () -> {
-			try {
-				return checkConnectivityAndStoreResult(properties);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-				return true; // Retry
-			}
-		};
-	}
-
-	private boolean checkConnectivityAndStoreResult(
-			MailboxProperties properties) throws DbException {
-		try {
-			List<MailboxVersion> serverSupports =
-					mailboxApi.getServerSupports(properties);
-			LOG.info("Own mailbox is reachable");
-			long now = clock.currentTimeMillis();
-			db.transaction(false, txn -> mailboxSettingsManager
-					.recordSuccessfulConnection(txn, now, serverSupports));
-			// Call the observers and cache the result
-			onConnectivityCheckSucceeded(now);
-			return false; // Don't retry
-		} catch (IOException | ApiException e) {
-			LOG.warning("Own mailbox is unreachable");
-			logException(LOG, WARNING, e);
-			long now = clock.currentTimeMillis();
-			db.transaction(false, txn -> mailboxSettingsManager
-					.recordFailedConnectionAttempt(txn, now));
-		}
-		return true; // Retry
-	}
-}

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

@@ -1,369 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.Cancellable;
-import org.briarproject.bramble.api.contact.Contact;
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.contact.event.ContactAddedEvent;
-import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
-import org.briarproject.bramble.api.db.DatabaseComponent;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.db.NoSuchContactException;
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.event.EventBus;
-import org.briarproject.bramble.api.event.EventExecutor;
-import org.briarproject.bramble.api.event.EventListener;
-import org.briarproject.bramble.api.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.mailbox.MailboxUpdate;
-import org.briarproject.bramble.api.mailbox.MailboxUpdateManager;
-import org.briarproject.bramble.api.mailbox.MailboxUpdateWithMailbox;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.mailbox.ConnectivityChecker.ConnectivityObserver;
-import org.briarproject.bramble.mailbox.MailboxApi.ApiException;
-import org.briarproject.bramble.mailbox.MailboxApi.MailboxContact;
-import org.briarproject.bramble.mailbox.MailboxApi.TolerableFailureException;
-
-import java.io.IOException;
-import java.util.Collection;
-import java.util.HashSet;
-import java.util.LinkedList;
-import java.util.Queue;
-import java.util.Set;
-import java.util.concurrent.Executor;
-import java.util.logging.Logger;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.GuardedBy;
-import javax.annotation.concurrent.ThreadSafe;
-
-import static java.util.logging.Level.INFO;
-import static java.util.logging.Level.WARNING;
-import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@ThreadSafe
-@NotNullByDefault
-class OwnMailboxContactListWorker
-		implements MailboxWorker, ConnectivityObserver, EventListener {
-
-	/**
-	 * When the worker is started it waits for a connectivity check, then
-	 * fetches the remote contact list and compares it to the local contact
-	 * list.
-	 * <p>
-	 * Any contacts that are missing from the remote list are added to the
-	 * mailbox's contact list, while any contacts that are missing from the
-	 * local list are removed from the mailbox's contact list.
-	 * <p>
-	 * Once the remote contact list has been brought up to date, the worker
-	 * waits for events indicating that contacts have been added or removed.
-	 * Each time an event is received, the worker updates the mailbox's
-	 * contact list and then goes back to waiting.
-	 */
-	private enum State {
-		CREATED,
-		CONNECTIVITY_CHECK,
-		FETCHING_CONTACT_LIST,
-		UPDATING_CONTACT_LIST,
-		WAITING_FOR_CHANGES,
-		DESTROYED
-	}
-
-	private static final Logger LOG =
-			getLogger(OwnMailboxContactListWorker.class.getName());
-
-	private final Executor ioExecutor;
-	private final DatabaseComponent db;
-	private final EventBus eventBus;
-	private final ConnectivityChecker connectivityChecker;
-	private final MailboxApiCaller mailboxApiCaller;
-	private final MailboxApi mailboxApi;
-	private final MailboxUpdateManager mailboxUpdateManager;
-	private final MailboxProperties mailboxProperties;
-	private final Object lock = new Object();
-
-	@GuardedBy("lock")
-	private State state = State.CREATED;
-
-	@GuardedBy("lock")
-	@Nullable
-	private Cancellable apiCall = null;
-
-	/**
-	 * A queue of updates waiting to be applied to the remote contact list.
-	 */
-	@GuardedBy("lock")
-	private final Queue<Update> updates = new LinkedList<>();
-
-	OwnMailboxContactListWorker(@IoExecutor Executor ioExecutor,
-			DatabaseComponent db,
-			EventBus eventBus,
-			ConnectivityChecker connectivityChecker,
-			MailboxApiCaller mailboxApiCaller,
-			MailboxApi mailboxApi,
-			MailboxUpdateManager mailboxUpdateManager,
-			MailboxProperties mailboxProperties) {
-		if (!mailboxProperties.isOwner()) throw new IllegalArgumentException();
-		this.ioExecutor = ioExecutor;
-		this.db = db;
-		this.connectivityChecker = connectivityChecker;
-		this.mailboxApiCaller = mailboxApiCaller;
-		this.mailboxApi = mailboxApi;
-		this.mailboxUpdateManager = mailboxUpdateManager;
-		this.mailboxProperties = mailboxProperties;
-		this.eventBus = eventBus;
-	}
-
-	@Override
-	public void start() {
-		LOG.info("Started");
-		synchronized (lock) {
-			if (state != State.CREATED) return;
-			state = State.CONNECTIVITY_CHECK;
-		}
-		// Avoid leaking observer in case destroy() is called concurrently
-		// before observer is added
-		connectivityChecker.checkConnectivity(mailboxProperties, this);
-		boolean destroyed;
-		synchronized (lock) {
-			destroyed = state == State.DESTROYED;
-		}
-		if (destroyed) connectivityChecker.removeObserver(this);
-	}
-
-	@Override
-	public void destroy() {
-		LOG.info("Destroyed");
-		Cancellable apiCall;
-		synchronized (lock) {
-			state = State.DESTROYED;
-			apiCall = this.apiCall;
-			this.apiCall = null;
-		}
-		if (apiCall != null) apiCall.cancel();
-		connectivityChecker.removeObserver(this);
-		eventBus.removeListener(this);
-	}
-
-	@Override
-	public void onConnectivityCheckSucceeded() {
-		LOG.info("Connectivity check succeeded");
-		synchronized (lock) {
-			if (state != State.CONNECTIVITY_CHECK) return;
-			state = State.FETCHING_CONTACT_LIST;
-			apiCall = mailboxApiCaller.retryWithBackoff(
-					new SimpleApiCall(this::apiCallFetchContactList));
-		}
-	}
-
-	@IoExecutor
-	private void apiCallFetchContactList() throws IOException, ApiException {
-		synchronized (lock) {
-			if (state != State.FETCHING_CONTACT_LIST) return;
-		}
-		LOG.info("Fetching remote contact list");
-		Collection<ContactId> remote =
-				mailboxApi.getContacts(mailboxProperties);
-		ioExecutor.execute(() -> loadLocalContactList(remote));
-	}
-
-	@IoExecutor
-	private void loadLocalContactList(Collection<ContactId> remote) {
-		synchronized (lock) {
-			if (state != State.FETCHING_CONTACT_LIST) return;
-			apiCall = null;
-		}
-		LOG.info("Loading local contact list");
-		try {
-			db.transaction(true, txn -> {
-				Collection<Contact> local = db.getContacts(txn);
-				// Handle the result on the event executor to avoid races with
-				// incoming events
-				txn.attach(() -> reconcileContactLists(local, remote));
-			});
-		} catch (DbException e) {
-			logException(LOG, WARNING, e);
-		}
-	}
-
-	@EventExecutor
-	private void reconcileContactLists(Collection<Contact> local,
-			Collection<ContactId> remote) {
-		Set<ContactId> localIds = new HashSet<>();
-		for (Contact c : local) localIds.add(c.getId());
-		remote = new HashSet<>(remote);
-		synchronized (lock) {
-			if (state != State.FETCHING_CONTACT_LIST) return;
-			for (ContactId c : localIds) {
-				if (!remote.contains(c)) updates.add(new Update(true, c));
-			}
-			for (ContactId c : remote) {
-				if (!localIds.contains(c)) updates.add(new Update(false, c));
-			}
-			if (updates.isEmpty()) {
-				LOG.info("Contact list is up to date");
-				state = State.WAITING_FOR_CHANGES;
-			} else {
-				if (LOG.isLoggable(INFO)) {
-					LOG.info(updates.size() + " updates to apply");
-				}
-				state = State.UPDATING_CONTACT_LIST;
-				ioExecutor.execute(this::updateContactList);
-			}
-		}
-	}
-
-	@IoExecutor
-	private void updateContactList() {
-		Update update;
-		synchronized (lock) {
-			if (state != State.UPDATING_CONTACT_LIST) return;
-			update = updates.poll();
-			if (update == null) {
-				LOG.info("No more updates to process");
-				state = State.WAITING_FOR_CHANGES;
-				apiCall = null;
-				return;
-			}
-		}
-		if (update.add) loadMailboxProperties(update.contactId);
-		else removeContact(update.contactId);
-	}
-
-	@IoExecutor
-	private void loadMailboxProperties(ContactId c) {
-		synchronized (lock) {
-			if (state != State.UPDATING_CONTACT_LIST) return;
-		}
-		LOG.info("Loading mailbox properties for contact");
-		try {
-			MailboxUpdate mailboxUpdate = db.transactionWithResult(true, txn ->
-					mailboxUpdateManager.getLocalUpdate(txn, c));
-			if (mailboxUpdate instanceof MailboxUpdateWithMailbox) {
-				addContact(c, (MailboxUpdateWithMailbox) mailboxUpdate);
-			} else {
-				// Our own mailbox was concurrently unpaired. This worker will
-				// be destroyed soon, so we can stop here
-				LOG.info("Own mailbox was unpaired");
-			}
-		} catch (NoSuchContactException e) {
-			// Contact was removed concurrently. Move on to the next update.
-			// Later we may process a removal update for this contact, which
-			// was never added to the mailbox's contact list. The removal API
-			// call should fail safely with a TolerableFailureException
-			LOG.info("No such contact");
-			updateContactList();
-		} catch (DbException e) {
-			logException(LOG, WARNING, e);
-		}
-	}
-
-	@IoExecutor
-	private void addContact(ContactId c, MailboxUpdateWithMailbox withMailbox) {
-		MailboxProperties props = withMailbox.getMailboxProperties();
-		MailboxContact contact = new MailboxContact(c, props.getAuthToken(),
-				requireNonNull(props.getInboxId()),
-				requireNonNull(props.getOutboxId()));
-		synchronized (lock) {
-			if (state != State.UPDATING_CONTACT_LIST) return;
-			apiCall = mailboxApiCaller.retryWithBackoff(new SimpleApiCall(() ->
-					apiCallAddContact(contact)));
-		}
-	}
-
-	@IoExecutor
-	private void apiCallAddContact(MailboxContact contact)
-			throws IOException, ApiException, TolerableFailureException {
-		synchronized (lock) {
-			if (state != State.UPDATING_CONTACT_LIST) return;
-		}
-		LOG.info("Adding contact to remote contact list");
-		mailboxApi.addContact(mailboxProperties, contact);
-		updateContactList();
-	}
-
-	@IoExecutor
-	private void removeContact(ContactId c) {
-		synchronized (lock) {
-			if (state != State.UPDATING_CONTACT_LIST) return;
-			apiCall = mailboxApiCaller.retryWithBackoff(new SimpleApiCall(() ->
-					apiCallRemoveContact(c)));
-		}
-	}
-
-	@IoExecutor
-	private void apiCallRemoveContact(ContactId c)
-			throws IOException, ApiException {
-		synchronized (lock) {
-			if (state != State.UPDATING_CONTACT_LIST) return;
-		}
-		LOG.info("Removing contact from remote contact list");
-		try {
-			mailboxApi.deleteContact(mailboxProperties, c);
-		} catch (TolerableFailureException e) {
-			// Catch this so we can continue to the next update
-			logException(LOG, INFO, e);
-		}
-		updateContactList();
-	}
-
-	@Override
-	public void eventOccurred(Event e) {
-		if (e instanceof ContactAddedEvent) {
-			LOG.info("Contact added");
-			onContactAdded(((ContactAddedEvent) e).getContactId());
-		} else if (e instanceof ContactRemovedEvent) {
-			LOG.info("Contact removed");
-			onContactRemoved(((ContactRemovedEvent) e).getContactId());
-		}
-	}
-
-	@EventExecutor
-	private void onContactAdded(ContactId c) {
-		synchronized (lock) {
-			if (state != State.UPDATING_CONTACT_LIST &&
-					state != State.WAITING_FOR_CHANGES) {
-				return;
-			}
-			updates.add(new Update(true, c));
-			if (state == State.WAITING_FOR_CHANGES) {
-				state = State.UPDATING_CONTACT_LIST;
-				ioExecutor.execute(this::updateContactList);
-			}
-		}
-	}
-
-	@EventExecutor
-	private void onContactRemoved(ContactId c) {
-		synchronized (lock) {
-			if (state != State.UPDATING_CONTACT_LIST &&
-					state != State.WAITING_FOR_CHANGES) {
-				return;
-			}
-			updates.add(new Update(false, c));
-			if (state == State.WAITING_FOR_CHANGES) {
-				state = State.UPDATING_CONTACT_LIST;
-				ioExecutor.execute(this::updateContactList);
-			}
-		}
-	}
-
-	/**
-	 * An update that should be applied to the remote contact list.
-	 */
-	private static class Update {
-
-		/**
-		 * True if the contact should be added, false if the contact should be
-		 * removed.
-		 */
-		private final boolean add;
-		private final ContactId contactId;
-
-		private Update(boolean add, ContactId contactId) {
-			this.add = add;
-			this.contactId = contactId;
-		}
-	}
-}

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

@@ -1,55 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.mailbox.MailboxApi.ApiException;
-import org.briarproject.bramble.mailbox.MailboxApi.TolerableFailureException;
-
-import java.io.IOException;
-import java.util.logging.Logger;
-
-import static java.util.logging.Level.INFO;
-import static java.util.logging.Level.WARNING;
-import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-/**
- * Convenience class for making simple API calls that don't return values.
- */
-@NotNullByDefault
-class SimpleApiCall implements ApiCall {
-
-	private static final Logger LOG = getLogger(SimpleApiCall.class.getName());
-
-	private final Attempt attempt;
-
-	SimpleApiCall(Attempt attempt) {
-		this.attempt = attempt;
-	}
-
-	@Override
-	public boolean callApi() {
-		try {
-			attempt.tryToCallApi();
-			return false; // Succeeded, don't retry
-		} catch (IOException | ApiException e) {
-			logException(LOG, WARNING, e);
-			return true; // Failed, retry with backoff
-		} catch (TolerableFailureException e) {
-			logException(LOG, INFO, e);
-			return false; // Failed tolerably, don't retry
-		}
-	}
-
-	interface Attempt {
-
-		/**
-		 * Makes a single attempt to call an API endpoint. If this method
-		 * throws an {@link IOException} or an {@link ApiException}, the call
-		 * will be retried. If it throws a {@link TolerableFailureException}
-		 * or returns without throwing an exception, the call will not be
-		 * retried.
-		 */
-		void tryToCallApi()
-				throws IOException, ApiException, TolerableFailureException;
-	}
-}

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

@@ -1,51 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.Plugin;
-
-import javax.annotation.concurrent.ThreadSafe;
-
-import static java.util.concurrent.TimeUnit.MINUTES;
-
-@ThreadSafe
-@NotNullByDefault
-interface TorReachabilityMonitor {
-
-	/**
-	 * How long the Tor plugin needs to be continuously
-	 * {@link Plugin.State#ACTIVE active} before we assume our contacts can
-	 * reach our hidden service.
-	 */
-	long REACHABILITY_PERIOD_MS = MINUTES.toMillis(10);
-
-	/**
-	 * Starts the monitor.
-	 */
-	void start();
-
-	/**
-	 * Destroys the monitor.
-	 */
-	void destroy();
-
-	/**
-	 * Adds an observer that will be called when our Tor hidden service becomes
-	 * reachable. If our hidden service is already reachable, the observer is
-	 * called immediately.
-	 * <p>
-	 * Observers are removed after being called, or when the monitor is
-	 * {@link #destroy() destroyed}.
-	 */
-	void addOneShotObserver(TorReachabilityObserver o);
-
-	/**
-	 * Removes an observer that was added via
-	 * {@link #addOneShotObserver(TorReachabilityObserver)}.
-	 */
-	void removeObserver(TorReachabilityObserver o);
-
-	interface TorReachabilityObserver {
-
-		void onTorReachable();
-	}
-}

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

@@ -1,137 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.Cancellable;
-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.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.Plugin;
-import org.briarproject.bramble.api.plugin.PluginManager;
-import org.briarproject.bramble.api.plugin.event.TransportActiveEvent;
-import org.briarproject.bramble.api.plugin.event.TransportInactiveEvent;
-import org.briarproject.bramble.api.system.TaskScheduler;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.concurrent.Executor;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.GuardedBy;
-import javax.annotation.concurrent.ThreadSafe;
-import javax.inject.Inject;
-
-import static java.util.concurrent.TimeUnit.MILLISECONDS;
-import static org.briarproject.bramble.api.plugin.Plugin.State.ACTIVE;
-import static org.briarproject.bramble.api.plugin.TorConstants.ID;
-
-@ThreadSafe
-@NotNullByDefault
-class TorReachabilityMonitorImpl
-		implements TorReachabilityMonitor, EventListener {
-
-	private final Executor ioExecutor;
-	private final TaskScheduler taskScheduler;
-	private final PluginManager pluginManager;
-	private final EventBus eventBus;
-	private final Object lock = new Object();
-
-	@GuardedBy("lock")
-	private boolean reachable = false, destroyed = false;
-
-	@GuardedBy("lock")
-	private final List<TorReachabilityObserver> observers = new ArrayList<>();
-
-	@GuardedBy("lock")
-	@Nullable
-	private Cancellable task = null;
-
-	@Inject
-	TorReachabilityMonitorImpl(
-			@IoExecutor Executor ioExecutor,
-			TaskScheduler taskScheduler,
-			PluginManager pluginManager,
-			EventBus eventBus) {
-		this.ioExecutor = ioExecutor;
-		this.taskScheduler = taskScheduler;
-		this.pluginManager = pluginManager;
-		this.eventBus = eventBus;
-	}
-
-	@Override
-	public void start() {
-		eventBus.addListener(this);
-		Plugin plugin = pluginManager.getPlugin(ID);
-		if (plugin != null && plugin.getState() == ACTIVE) onTorActive();
-	}
-
-	@Override
-	public void destroy() {
-		eventBus.removeListener(this);
-		synchronized (lock) {
-			destroyed = true;
-			if (task != null) task.cancel();
-			task = null;
-			observers.clear();
-		}
-	}
-
-	@Override
-	public void addOneShotObserver(TorReachabilityObserver o) {
-		boolean callNow = false;
-		synchronized (lock) {
-			if (destroyed) return;
-			if (reachable) callNow = true;
-			else observers.add(o);
-		}
-		if (callNow) o.onTorReachable();
-	}
-
-	@Override
-	public void removeObserver(TorReachabilityObserver o) {
-		synchronized (lock) {
-			if (destroyed) return;
-			observers.remove(o);
-		}
-	}
-
-	@Override
-	public void eventOccurred(Event e) {
-		if (e instanceof TransportActiveEvent) {
-			TransportActiveEvent t = (TransportActiveEvent) e;
-			if (t.getTransportId().equals(ID)) onTorActive();
-		} else if (e instanceof TransportInactiveEvent) {
-			TransportInactiveEvent t = (TransportInactiveEvent) e;
-			if (t.getTransportId().equals(ID)) onTorInactive();
-		}
-	}
-
-	private void onTorActive() {
-		synchronized (lock) {
-			if (destroyed || task != null) return;
-			task = taskScheduler.schedule(this::onTorReachable, ioExecutor,
-					REACHABILITY_PERIOD_MS, MILLISECONDS);
-		}
-	}
-
-	private void onTorInactive() {
-		synchronized (lock) {
-			reachable = false;
-			if (task != null) task.cancel();
-			task = null;
-		}
-	}
-
-	@IoExecutor
-	private void onTorReachable() {
-		List<TorReachabilityObserver> observers;
-		synchronized (lock) {
-			if (destroyed) return;
-			reachable = true;
-			observers = new ArrayList<>(this.observers);
-			this.observers.clear();
-			task = null;
-		}
-		for (TorReachabilityObserver o : observers) o.onTorReachable();
-	}
-}

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

@@ -1,17 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-/**
- * An interface for converting an onion address to an HTTP URL, allowing the
- * conversion to be customised for integration tests.
- */
-@NotNullByDefault
-interface UrlConverter {
-
-   /**
-    * Converts a raw onion address, excluding the .onion suffix, into an
-    * HTTP URL.
-    */
-   String convertOnionToBaseUrl(String onion);
-}

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

@@ -1,18 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.inject.Inject;
-
-@NotNullByDefault
-class UrlConverterImpl implements UrlConverter {
-
-	@Inject
-	UrlConverterImpl() {
-	}
-
-	@Override
-	public String convertOnionToBaseUrl(String onion) {
-		return "http://" + onion + ".onion";
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/plugin/PollerImpl.java

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.plugin;
 
-import org.briarproject.bramble.api.Cancellable;
 import org.briarproject.bramble.api.Pair;
 import org.briarproject.bramble.api.connection.ConnectionManager;
 import org.briarproject.bramble.api.connection.ConnectionRegistry;
@@ -28,6 +27,7 @@ import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.properties.TransportPropertyManager;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.system.TaskScheduler;
+import org.briarproject.bramble.api.system.TaskScheduler.Cancellable;
 import org.briarproject.bramble.api.system.Wakeful;
 import org.briarproject.bramble.api.system.WakefulIoExecutor;
 

bramble-core/src/main/java/org/briarproject/bramble/plugin/bluetooth/AbstractBluetoothPlugin.java

@@ -427,13 +427,7 @@ abstract class AbstractBluetoothPlugin<S, SS> implements BluetoothPlugin,
 		BdfList descriptor = new BdfList();
 		descriptor.add(TRANSPORT_ID_BLUETOOTH);
 		String address = getBluetoothAddress();
-		if (address != null) {
-			try {
-				descriptor.add(macToBytes(address));
-			} catch (FormatException e) {
-				throw new RuntimeException();
-			}
-		}
+		if (address != null) descriptor.add(macToBytes(address));
 		return new BluetoothKeyAgreementListener(descriptor, ss);
 	}
 

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

@@ -67,7 +67,6 @@ abstract class AbstractRemovableDrivePlugin implements SimplexPlugin {
 	public void start() {
 		callback.mergeLocalProperties(
 				new TransportProperties(singletonMap(PROP_SUPPORTED, "true")));
-		callback.pluginStateChanged(ACTIVE);
 	}
 
 	@Override

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

@@ -11,7 +11,6 @@ import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
-import java.io.OutputStream;
 import java.util.logging.Logger;
 
 import static java.util.logging.Level.WARNING;
@@ -30,6 +29,11 @@ abstract class FilePlugin implements SimplexPlugin {
 	protected final PluginCallback callback;
 	protected final long maxLatency;
 
+	protected abstract void writerFinished(File f, boolean exception);
+
+	protected abstract void readerFinished(File f, boolean exception,
+			boolean recognised);
+
 	FilePlugin(PluginCallback callback, long maxLatency) {
 		this.callback = callback;
 		this.maxLatency = maxLatency;
@@ -46,8 +50,9 @@ abstract class FilePlugin implements SimplexPlugin {
 		String path = p.get(PROP_PATH);
 		if (isNullOrEmpty(path)) return null;
 		try {
-			FileInputStream in = new FileInputStream(path);
-			return new TransportInputStreamReader(in);
+			File file = new File(path);
+			FileInputStream in = new FileInputStream(file);
+			return new FileTransportReader(file, in, this);
 		} catch (IOException e) {
 			logException(LOG, WARNING, e);
 			return null;
@@ -65,8 +70,8 @@ abstract class FilePlugin implements SimplexPlugin {
 				LOG.info("Failed to create file");
 				return null;
 			}
-			OutputStream out = new FileOutputStream(file);
-			return new TransportOutputStreamWriter(this, out);
+			FileOutputStream out = new FileOutputStream(file);
+			return new FileTransportWriter(file, out, this);
 		} catch (IOException e) {
 			logException(LOG, WARNING, e);
 			return null;

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

@@ -0,0 +1,39 @@
+package org.briarproject.bramble.plugin.file;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.TransportConnectionReader;
+
+import java.io.File;
+import java.io.InputStream;
+import java.util.logging.Logger;
+
+import static java.util.logging.Level.WARNING;
+import static org.briarproject.bramble.util.IoUtils.tryToClose;
+
+@NotNullByDefault
+class FileTransportReader implements TransportConnectionReader {
+
+	private static final Logger LOG =
+			Logger.getLogger(FileTransportReader.class.getName());
+
+	private final File file;
+	private final InputStream in;
+	private final FilePlugin plugin;
+
+	FileTransportReader(File file, InputStream in, FilePlugin plugin) {
+		this.file = file;
+		this.in = in;
+		this.plugin = plugin;
+	}
+
+	@Override
+	public InputStream getInputStream() {
+		return in;
+	}
+
+	@Override
+	public void dispose(boolean exception, boolean recognised) {
+		tryToClose(in, LOG, WARNING);
+		plugin.readerFinished(file, exception, recognised);
+	}
+}

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

@@ -0,0 +1,54 @@
+package org.briarproject.bramble.plugin.file;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
+
+import java.io.File;
+import java.io.OutputStream;
+import java.util.logging.Logger;
+
+import static java.util.logging.Level.WARNING;
+import static org.briarproject.bramble.util.IoUtils.tryToClose;
+
+@NotNullByDefault
+class FileTransportWriter implements TransportConnectionWriter {
+
+	private static final Logger LOG =
+			Logger.getLogger(FileTransportWriter.class.getName());
+
+	private final File file;
+	private final OutputStream out;
+	private final FilePlugin plugin;
+
+	FileTransportWriter(File file, OutputStream out, FilePlugin plugin) {
+		this.file = file;
+		this.out = out;
+		this.plugin = plugin;
+	}
+
+	@Override
+	public long getMaxLatency() {
+		return plugin.getMaxLatency();
+	}
+
+	@Override
+	public int getMaxIdleTime() {
+		return plugin.getMaxIdleTime();
+	}
+
+	@Override
+	public boolean isLossyAndCheap() {
+		return plugin.isLossyAndCheap();
+	}
+
+	@Override
+	public OutputStream getOutputStream() {
+		return out;
+	}
+
+	@Override
+	public void dispose(boolean exception) {
+		tryToClose(out, LOG, WARNING);
+		plugin.writerFinished(file, exception);
+	}
+}

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

@@ -1,73 +0,0 @@
-package org.briarproject.bramble.plugin.file;
-
-import org.briarproject.bramble.api.Pair;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.ConnectionHandler;
-import org.briarproject.bramble.api.plugin.PluginCallback;
-import org.briarproject.bramble.api.plugin.PluginException;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.properties.TransportProperties;
-
-import java.util.Collection;
-
-import static org.briarproject.bramble.api.mailbox.MailboxConstants.ID;
-import static org.briarproject.bramble.api.plugin.Plugin.State.ACTIVE;
-
-@NotNullByDefault
-class MailboxPlugin extends FilePlugin {
-
-	MailboxPlugin(PluginCallback callback, long maxLatency) {
-		super(callback, maxLatency);
-	}
-
-	@Override
-	public TransportId getId() {
-		return ID;
-	}
-
-	@Override
-	public int getMaxIdleTime() {
-		// Unused for simplex transports
-		throw new UnsupportedOperationException();
-	}
-
-	@Override
-	public void start() throws PluginException {
-		callback.pluginStateChanged(ACTIVE);
-	}
-
-	@Override
-	public void stop() throws PluginException {
-	}
-
-	@Override
-	public State getState() {
-		return ACTIVE;
-	}
-
-	@Override
-	public int getReasonsDisabled() {
-		return 0;
-	}
-
-	@Override
-	public boolean shouldPoll() {
-		return false;
-	}
-
-	@Override
-	public int getPollingInterval() {
-		throw new UnsupportedOperationException();
-	}
-
-	@Override
-	public void poll(
-			Collection<Pair<TransportProperties, ConnectionHandler>> properties) {
-		throw new UnsupportedOperationException();
-	}
-
-	@Override
-	public boolean isLossyAndCheap() {
-		return false;
-	}
-}

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

@@ -1,37 +0,0 @@
-package org.briarproject.bramble.plugin.file;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.PluginCallback;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.simplex.SimplexPlugin;
-import org.briarproject.bramble.api.plugin.simplex.SimplexPluginFactory;
-
-import javax.annotation.Nullable;
-import javax.inject.Inject;
-
-import static org.briarproject.bramble.api.mailbox.MailboxConstants.ID;
-import static org.briarproject.bramble.api.mailbox.MailboxConstants.MAX_LATENCY;
-
-@NotNullByDefault
-public class MailboxPluginFactory implements SimplexPluginFactory {
-
-	@Inject
-	MailboxPluginFactory() {
-	}
-
-	@Override
-	public TransportId getId() {
-		return ID;
-	}
-
-	@Override
-	public long getMaxLatency() {
-		return MAX_LATENCY;
-	}
-
-	@Nullable
-	@Override
-	public SimplexPlugin createPlugin(PluginCallback callback) {
-		return new MailboxPlugin(callback, MAX_LATENCY);
-	}
-}

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

@@ -106,8 +106,7 @@ class RemovableDriveManagerImpl
 	@Override
 	public boolean isWriterTaskNeeded(ContactId c) throws DbException {
 		return db.transactionWithResult(true, txn ->
-				db.containsAcksToSend(txn, c) ||
-						db.containsMessagesToSend(txn, c, MAX_LATENCY, true));
+				db.containsAnythingToSend(txn, c, MAX_LATENCY, true));
 	}
 
 	@Override

bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/LanTcpPlugin.java

@@ -285,7 +285,7 @@ class LanTcpPlugin extends TcpPlugin {
 				if (ip.length == 16) addrs.add(InetAddress.getByAddress(ip));
 			}
 			return addrs;
-		} catch (FormatException | UnknownHostException e) {
+		} catch (IllegalArgumentException | UnknownHostException e) {
 			return emptyList();
 		}
 	}

bramble-core/src/main/java/org/briarproject/bramble/plugin/tor/CircumventionProvider.java

@@ -27,7 +27,7 @@ public interface CircumventionProvider {
 	 * Countries where bridge connections are likely to work.
 	 * Should be a subset of {@link #BLOCKED} and the union of
 	 * {@link #DEFAULT_BRIDGES}, {@link #NON_DEFAULT_BRIDGES} and
-	 * {@link #DPI_BRIDGES}.
+	 * {@link #MEEK_BRIDGES}.
 	 */
 	String[] BRIDGES = {"BY", "CN", "EG", "IR", "RU", "TM", "VE"};
 
@@ -44,10 +44,10 @@ public interface CircumventionProvider {
 	String[] NON_DEFAULT_BRIDGES = {"BY", "RU", "TM"};
 
 	/**
-	 * Countries where vanilla bridges are blocked via DPI but non-default
-	 * obfs4 bridges and meek may work. Should be a subset of {@link #BRIDGES}.
+	 * Countries where obfs4 and vanilla bridges won't work and meek is needed.
+	 * Should be a subset of {@link #BRIDGES}.
 	 */
-	String[] DPI_BRIDGES = {"CN", "IR"};
+	String[] MEEK_BRIDGES = {"CN", "IR"};
 
 	/**
 	 * Returns true if vanilla Tor connections are blocked in the given country.

bramble-core/src/main/java/org/briarproject/bramble/plugin/tor/CircumventionProviderImpl.java

@@ -14,6 +14,7 @@ import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
 import static java.util.Arrays.asList;
+import static java.util.Collections.singletonList;
 import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
 import static org.briarproject.bramble.plugin.tor.CircumventionProvider.BridgeType.DEFAULT_OBFS4;
 import static org.briarproject.bramble.plugin.tor.CircumventionProvider.BridgeType.MEEK;
@@ -34,8 +35,8 @@ class CircumventionProviderImpl implements CircumventionProvider {
 			new HashSet<>(asList(DEFAULT_BRIDGES));
 	private static final Set<String> NON_DEFAULT_BRIDGE_COUNTRIES =
 			new HashSet<>(asList(NON_DEFAULT_BRIDGES));
-	private static final Set<String> DPI_COUNTRIES =
-			new HashSet<>(asList(DPI_BRIDGES));
+	private static final Set<String> MEEK_COUNTRIES =
+			new HashSet<>(asList(MEEK_BRIDGES));
 
 	@Inject
 	CircumventionProviderImpl() {
@@ -57,8 +58,8 @@ class CircumventionProviderImpl implements CircumventionProvider {
 			return asList(DEFAULT_OBFS4, VANILLA);
 		} else if (NON_DEFAULT_BRIDGE_COUNTRIES.contains(countryCode)) {
 			return asList(NON_DEFAULT_OBFS4, VANILLA);
-		} else if (DPI_COUNTRIES.contains(countryCode)) {
-			return asList(NON_DEFAULT_OBFS4, MEEK);
+		} else if (MEEK_COUNTRIES.contains(countryCode)) {
+			return singletonList(MEEK);
 		} else {
 			return asList(DEFAULT_OBFS4, VANILLA);
 		}