Refactor ContactExchangeTask into reusable manager.

bramble-api/src/main/java/org/briarproject/bramble/api/contact/ContactExchangeManager.java

@@ -0,0 +1,16 @@
+package org.briarproject.bramble.api.contact;
+
+import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
+
+@NotNullByDefault
+public interface ContactExchangeManager {
+
+	/**
+	 * Exchanges contact information with a remote peer.
+	 */
+	void exchangeContacts(TransportId t, DuplexTransportConnection conn,
+			SecretKey masterKey, boolean alice);
+}

bramble-core/src/main/java/org/briarproject/bramble/contact/ContactExchangeConstants.java

@@ -1,16 +1,6 @@
-package org.briarproject.bramble.api.contact;
+package org.briarproject.bramble.contact;
 
-import org.briarproject.bramble.api.crypto.SecretKey;
-import org.briarproject.bramble.api.identity.LocalAuthor;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-
-/**
- * A task for conducting a contact information exchange with a remote peer.
- */
-@NotNullByDefault
-public interface ContactExchangeTask {
+interface ContactExchangeConstants {
 
 	/**
 	 * The current version of the contact exchange protocol.
@@ -42,11 +32,4 @@ public interface ContactExchangeTask {
 	 * Label for signing key binding nonces.
 	 */
 	String SIGNING_LABEL = "org.briarproject.briar.contact/EXCHANGE";
-
-	/**
-	 * Exchanges contact information with a remote peer.
-	 */
-	void exchangeContacts(LocalAuthor localAuthor, SecretKey masterKey,
-			DuplexTransportConnection conn, TransportId transportId,
-			boolean alice);
 }

bramble-core/src/main/java/org/briarproject/bramble/contact/ContactExchangeManagerImpl.java

@@ -3,7 +3,7 @@ package org.briarproject.bramble.contact;
 import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.Predicate;
 import org.briarproject.bramble.api.client.ClientHelper;
-import org.briarproject.bramble.api.contact.ContactExchangeTask;
+import org.briarproject.bramble.api.contact.ContactExchangeManager;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.contact.event.ContactExchangeFailedEvent;
@@ -17,6 +17,7 @@ import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.identity.Author;
+import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.identity.LocalAuthor;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
@@ -49,16 +50,22 @@ import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.contact.RecordTypes.CONTACT_INFO;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_SIGNATURE_LENGTH;
+import static org.briarproject.bramble.contact.ContactExchangeConstants.ALICE_KEY_LABEL;
+import static org.briarproject.bramble.contact.ContactExchangeConstants.ALICE_NONCE_LABEL;
+import static org.briarproject.bramble.contact.ContactExchangeConstants.BOB_KEY_LABEL;
+import static org.briarproject.bramble.contact.ContactExchangeConstants.BOB_NONCE_LABEL;
+import static org.briarproject.bramble.contact.ContactExchangeConstants.PROTOCOL_VERSION;
+import static org.briarproject.bramble.contact.ContactExchangeConstants.SIGNING_LABEL;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.ValidationUtils.checkLength;
 import static org.briarproject.bramble.util.ValidationUtils.checkSize;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-class ContactExchangeTaskImpl implements ContactExchangeTask {
+class ContactExchangeManagerImpl implements ContactExchangeManager {
 
 	private static final Logger LOG =
-			getLogger(ContactExchangeTaskImpl.class.getName());
+			getLogger(ContactExchangeManagerImpl.class.getName());
 
 	// Accept records with current protocol version, known record type
 	private static final Predicate<Record> ACCEPT = r ->
@@ -82,17 +89,18 @@ class ContactExchangeTaskImpl implements ContactExchangeTask {
 	private final Clock clock;
 	private final ConnectionManager connectionManager;
 	private final ContactManager contactManager;
+	private final IdentityManager identityManager;
 	private final TransportPropertyManager transportPropertyManager;
 	private final CryptoComponent crypto;
 	private final StreamReaderFactory streamReaderFactory;
 	private final StreamWriterFactory streamWriterFactory;
 
 	@Inject
-	ContactExchangeTaskImpl(DatabaseComponent db, ClientHelper clientHelper,
+	ContactExchangeManagerImpl(DatabaseComponent db, ClientHelper clientHelper,
 			RecordReaderFactory recordReaderFactory,
 			RecordWriterFactory recordWriterFactory, EventBus eventBus,
 			Clock clock, ConnectionManager connectionManager,
-			ContactManager contactManager,
+			ContactManager contactManager, IdentityManager identityManager,
 			TransportPropertyManager transportPropertyManager,
 			CryptoComponent crypto, StreamReaderFactory streamReaderFactory,
 			StreamWriterFactory streamWriterFactory) {
@@ -104,6 +112,7 @@ class ContactExchangeTaskImpl implements ContactExchangeTask {
 		this.clock = clock;
 		this.connectionManager = connectionManager;
 		this.contactManager = contactManager;
+		this.identityManager = identityManager;
 		this.transportPropertyManager = transportPropertyManager;
 		this.crypto = crypto;
 		this.streamReaderFactory = streamReaderFactory;
@@ -111,9 +120,8 @@ class ContactExchangeTaskImpl implements ContactExchangeTask {
 	}
 
 	@Override
-	public void exchangeContacts(LocalAuthor localAuthor,
-			SecretKey masterKey, DuplexTransportConnection conn,
-			TransportId transportId, boolean alice) {
+	public void exchangeContacts(TransportId t, DuplexTransportConnection conn,
+			SecretKey masterKey, boolean alice) {
 		// Get the transport connection's input and output streams
 		InputStream in;
 		OutputStream out;
@@ -127,9 +135,11 @@ class ContactExchangeTaskImpl implements ContactExchangeTask {
 			return;
 		}
 
-		// Get the local transport properties
+		// Get the local author and transport properties
+		LocalAuthor localAuthor;
 		Map<TransportId, TransportProperties> localProperties;
 		try {
+			localAuthor = identityManager.getLocalAuthor();
 			localProperties = transportPropertyManager.getLocalProperties();
 		} catch (DbException e) {
 			logException(LOG, WARNING, e);
@@ -210,8 +220,7 @@ class ContactExchangeTaskImpl implements ContactExchangeTask {
 			ContactId contactId = addContact(remoteInfo.author, localAuthor,
 					masterKey, timestamp, alice, remoteInfo.properties);
 			// Reuse the connection as a transport connection
-			connectionManager.manageOutgoingConnection(contactId, transportId,
-					conn);
+			connectionManager.manageOutgoingConnection(contactId, t, conn);
 			// Pseudonym exchange succeeded
 			LOG.info("Pseudonym exchange succeeded");
 			eventBus.broadcast(

bramble-core/src/main/java/org/briarproject/bramble/contact/ContactModule.java

@@ -1,6 +1,6 @@
 package org.briarproject.bramble.contact;
 
-import org.briarproject.bramble.api.contact.ContactExchangeTask;
+import org.briarproject.bramble.api.contact.ContactExchangeManager;
 import org.briarproject.bramble.api.contact.ContactManager;
 
 import javax.inject.Inject;
@@ -19,14 +19,14 @@ public class ContactModule {
 
 	@Provides
 	@Singleton
-	ContactManager getContactManager(ContactManagerImpl contactManager) {
+	ContactManager provideContactManager(ContactManagerImpl contactManager) {
 		return contactManager;
 	}
 
 	@Provides
-	ContactExchangeTask provideContactExchangeTask(
-			ContactExchangeTaskImpl contactExchangeTask) {
-		return contactExchangeTask;
+	ContactExchangeManager provideContactExchangeManager(
+			ContactExchangeManagerImpl contactExchangeManager) {
+		return contactExchangeManager;
 	}
 
 	@Provides

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

@@ -8,7 +8,7 @@ import org.briarproject.bramble.BrambleCoreEagerSingletons;
 import org.briarproject.bramble.BrambleCoreModule;
 import org.briarproject.bramble.account.BriarAccountModule;
 import org.briarproject.bramble.api.account.AccountManager;
-import org.briarproject.bramble.api.contact.ContactExchangeTask;
+import org.briarproject.bramble.api.contact.ContactExchangeManager;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.crypto.CryptoExecutor;
 import org.briarproject.bramble.api.crypto.PasswordStrengthEstimator;
@@ -128,7 +128,7 @@ public interface AndroidComponent
 
 	SettingsManager settingsManager();
 
-	ContactExchangeTask contactExchangeTask();
+	ContactExchangeManager contactExchangeManager();
 
 	KeyAgreementTask keyAgreementTask();
 

briar-android/src/main/java/org/briarproject/briar/android/keyagreement/ContactExchangeActivity.java

@@ -4,15 +4,12 @@ import android.os.Bundle;
 import android.support.annotation.UiThread;
 import android.widget.Toast;
 
-import org.briarproject.bramble.api.contact.ContactExchangeTask;
+import org.briarproject.bramble.api.contact.ContactExchangeManager;
 import org.briarproject.bramble.api.contact.event.ContactExchangeFailedEvent;
 import org.briarproject.bramble.api.contact.event.ContactExchangeSucceededEvent;
-import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.identity.Author;
-import org.briarproject.bramble.api.identity.IdentityManager;
-import org.briarproject.bramble.api.identity.LocalAuthor;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementResult;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
@@ -21,32 +18,25 @@ import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 
 import java.util.concurrent.Executor;
-import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
 import static android.widget.Toast.LENGTH_LONG;
-import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.util.LogUtils.logException;
+import static java.util.Objects.requireNonNull;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public class ContactExchangeActivity extends KeyAgreementActivity implements
 		EventListener {
 
-	private static final Logger LOG =
-			Logger.getLogger(ContactExchangeActivity.class.getName());
-
 	@Inject
 	@IoExecutor
 	Executor ioExecutor;
 
 	// Fields that are accessed from background threads must be volatile
 	@Inject
-	volatile ContactExchangeTask contactExchangeTask;
-	@Inject
-	volatile IdentityManager identityManager;
+	volatile ContactExchangeManager contactExchangeManager;
 
 	@Override
 	public void injectActivity(ActivityComponent component) {
@@ -62,76 +52,62 @@ public class ContactExchangeActivity extends KeyAgreementActivity implements
 	@Override
 	public void onStart() {
 		super.onStart();
-		// Listen to updates from contactExchangeTask
+		// Listen to updates from ContactExchangeManager
 		eventBus.addListener(this);
 	}
 
 	@Override
 	protected void onStop() {
 		super.onStop();
-		// Stop listening to updates from contactExchangeTask
+		// Stop listening to updates from ContactExchangeManager
 		eventBus.addListener(this);
 	}
 
 	private void startContactExchange(KeyAgreementResult result) {
 		ioExecutor.execute(() -> {
-			LocalAuthor localAuthor;
-			// Load the local pseudonym
-			try {
-				localAuthor = identityManager.getLocalAuthor();
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-				contactExchangeFailed();
-				return;
-			}
 			// Exchange contact details
-			contactExchangeTask.exchangeContacts(localAuthor,
-					result.getMasterKey(), result.getConnection(),
-					result.getTransportId(), result.wasAlice());
+			contactExchangeManager.exchangeContacts(result.getTransportId(),
+					result.getConnection(), result.getMasterKey(),
+					result.wasAlice());
 		});
 	}
 
 	@Override
 	public void eventOccurred(Event e) {
 		if (e instanceof ContactExchangeSucceededEvent) {
-			contactExchangeSucceeded(
-					((ContactExchangeSucceededEvent) e).getRemoteAuthor());
+			ContactExchangeSucceededEvent c = (ContactExchangeSucceededEvent) e;
+			contactExchangeSucceeded(c.getRemoteAuthor());
 		} else if (e instanceof ContactExchangeFailedEvent) {
-			ContactExchangeFailedEvent fe = (ContactExchangeFailedEvent) e;
-			if (fe.wasDuplicateContact()) {
-				duplicateContact(fe.getDuplicateRemoteAuthor());
+			ContactExchangeFailedEvent c = (ContactExchangeFailedEvent) e;
+			if (c.wasDuplicateContact()) {
+				duplicateContact(requireNonNull(c.getDuplicateRemoteAuthor()));
 			} else {
 				contactExchangeFailed();
 			}
 		}
 	}
 
+	@UiThread
 	private void contactExchangeSucceeded(Author remoteAuthor) {
-		runOnUiThreadUnlessDestroyed(() -> {
-			String contactName = remoteAuthor.getName();
-			String format = getString(R.string.contact_added_toast);
-			String text = String.format(format, contactName);
-			Toast.makeText(ContactExchangeActivity.this, text, LENGTH_LONG)
-					.show();
-			supportFinishAfterTransition();
-		});
+		String contactName = remoteAuthor.getName();
+		String format = getString(R.string.contact_added_toast);
+		String text = String.format(format, contactName);
+		Toast.makeText(this, text, LENGTH_LONG).show();
+		supportFinishAfterTransition();
 	}
 
+	@UiThread
 	private void duplicateContact(Author remoteAuthor) {
-		runOnUiThreadUnlessDestroyed(() -> {
-			String contactName = remoteAuthor.getName();
-			String format = getString(R.string.contact_already_exists);
-			String text = String.format(format, contactName);
-			Toast.makeText(ContactExchangeActivity.this, text, LENGTH_LONG)
-					.show();
-			finish();
-		});
+		String contactName = remoteAuthor.getName();
+		String format = getString(R.string.contact_already_exists);
+		String text = String.format(format, contactName);
+		Toast.makeText(this, text, LENGTH_LONG).show();
+		finish();
 	}
 
+	@UiThread
 	private void contactExchangeFailed() {
-		runOnUiThreadUnlessDestroyed(() -> {
-			showErrorFragment(R.string.connection_error_explanation);
-		});
+		showErrorFragment(R.string.connection_error_explanation);
 	}
 
 	@UiThread