Allow event executor tasks to be attached to transactions.

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

@@ -0,0 +1,20 @@
+package org.briarproject.bramble.api.db;
+
+import org.briarproject.bramble.api.event.EventExecutor;
+
+/**
+ * An action that's taken when a {@link Transaction} is committed.
+ */
+public interface CommitAction {
+
+	void accept(Visitor visitor);
+
+	interface Visitor {
+
+		@EventExecutor
+		void visit(EventAction a);
+
+		@EventExecutor
+		void visit(TaskAction a);
+	}
+}

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

@@ -0,0 +1,24 @@
+package org.briarproject.bramble.api.db;
+
+import org.briarproject.bramble.api.event.Event;
+
+/**
+ * A {@link CommitAction} that broadcasts an event.
+ */
+public class EventAction implements CommitAction {
+
+	private final Event event;
+
+	EventAction(Event event) {
+		this.event = event;
+	}
+
+	public Event getEvent() {
+		return event;
+	}
+
+	@Override
+	public void accept(Visitor visitor) {
+		visitor.visit(this);
+	}
+}

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

@@ -0,0 +1,24 @@
+package org.briarproject.bramble.api.db;
+
+import org.briarproject.bramble.api.event.EventExecutor;
+
+/**
+ * A {@link CommitAction} that submits a task to the {@link EventExecutor}.
+ */
+public class TaskAction implements CommitAction {
+
+	private final Runnable task;
+
+	TaskAction(Runnable task) {
+		this.task = task;
+	}
+
+	public Runnable getTask() {
+		return task;
+	}
+
+	@Override
+	public void accept(Visitor visitor) {
+		visitor.visit(this);
+	}
+}

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

@@ -1,13 +1,15 @@
 package org.briarproject.bramble.api.db;
 
 import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.event.EventExecutor;
 
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;
 
 import javax.annotation.concurrent.NotThreadSafe;
 
+import static java.util.Collections.emptyList;
+
 /**
  * A wrapper around a database transaction. Transactions are not thread-safe.
  */
@@ -17,7 +19,7 @@ public class Transaction {
 	private final Object txn;
 	private final boolean readOnly;
 
-	private List<Event> events = null;
+	private List<CommitAction> actions = null;
 	private boolean committed = false;
 
 	public Transaction(Object txn, boolean readOnly) {
@@ -42,19 +44,27 @@ public class Transaction {
 
 	/**
 	 * Attaches an event to be broadcast when the transaction has been
-	 * committed.
+	 * committed. The event will be broadcast on the {@link EventExecutor}.
 	 */
 	public void attach(Event e) {
-		if (events == null) events = new ArrayList<>();
-		events.add(e);
+		if (actions == null) actions = new ArrayList<>();
+		actions.add(new EventAction(e));
 	}
 
 	/**
-	 * Returns any events attached to the transaction.
+	 * Attaches a task to be executed when the transaction has been
+	 * committed. The task will be run on the {@link EventExecutor}.
 	 */
-	public List<Event> getEvents() {
-		if (events == null) return Collections.emptyList();
-		return events;
+	public void attach(Runnable r) {
+		if (actions == null) actions = new ArrayList<>();
+		actions.add(new TaskAction(r));
+	}
+
+	/**
+	 * Returns any actions attached to the transaction.
+	 */
+	public List<CommitAction> getActions() {
+		return actions == null ? emptyList() : actions;
 	}
 
 	/**

bramble-api/src/main/java/org/briarproject/bramble/api/event/EventExecutor.java

@@ -11,8 +11,9 @@ import static java.lang.annotation.ElementType.PARAMETER;
 import static java.lang.annotation.RetentionPolicy.RUNTIME;
 
 /**
- * Annotation for injecting the executor for broadcasting events. Also used for
- * annotating methods that should run on the event executor.
+ * Annotation for injecting the executor for broadcasting events and running
+ * tasks that need to run in a defined order with respect to events. Also used
+ * for annotating methods that should run on the event executor.
  * <p>
  * The contract of this executor is that tasks are run in the order they're
  * submitted, tasks are not run concurrently, and submitting a task will never

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

@@ -7,11 +7,14 @@ import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
 import org.briarproject.bramble.api.contact.event.ContactStatusChangedEvent;
 import org.briarproject.bramble.api.contact.event.ContactVerifiedEvent;
 import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.db.CommitAction;
+import org.briarproject.bramble.api.db.CommitAction.Visitor;
 import org.briarproject.bramble.api.db.ContactExistsException;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbCallable;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.DbRunnable;
+import org.briarproject.bramble.api.db.EventAction;
 import org.briarproject.bramble.api.db.Metadata;
 import org.briarproject.bramble.api.db.MigrationListener;
 import org.briarproject.bramble.api.db.NoSuchContactException;
@@ -20,9 +23,10 @@ import org.briarproject.bramble.api.db.NoSuchLocalAuthorException;
 import org.briarproject.bramble.api.db.NoSuchMessageException;
 import org.briarproject.bramble.api.db.NoSuchTransportException;
 import org.briarproject.bramble.api.db.NullableDbCallable;
+import org.briarproject.bramble.api.db.TaskAction;
 import org.briarproject.bramble.api.db.Transaction;
-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.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorId;
 import org.briarproject.bramble.api.identity.LocalAuthor;
@@ -64,6 +68,7 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.Executor;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 import java.util.logging.Logger;
@@ -92,25 +97,29 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	private final Database<T> db;
 	private final Class<T> txnClass;
 	private final EventBus eventBus;
-	private final ShutdownManager shutdown;
+	private final Executor eventExecutor;
+	private final ShutdownManager shutdownManager;
 	private final AtomicBoolean closed = new AtomicBoolean(false);
 	private final ReentrantReadWriteLock lock =
 			new ReentrantReadWriteLock(true);
+	private final Visitor visitor = new CommitActionVisitor();
 
 	@Inject
 	DatabaseComponentImpl(Database<T> db, Class<T> txnClass, EventBus eventBus,
-			ShutdownManager shutdown) {
+			@EventExecutor Executor eventExecutor,
+			ShutdownManager shutdownManager) {
 		this.db = db;
 		this.txnClass = txnClass;
 		this.eventBus = eventBus;
-		this.shutdown = shutdown;
+		this.eventExecutor = eventExecutor;
+		this.shutdownManager = shutdownManager;
 	}
 
 	@Override
 	public boolean open(SecretKey key, @Nullable MigrationListener listener)
 			throws DbException {
 		boolean reopened = db.open(key, listener);
-		shutdown.addShutdownHook(() -> {
+		shutdownManager.addShutdownHook(() -> {
 			try {
 				close();
 			} catch (DbException e) {
@@ -161,7 +170,8 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		try {
 			T txn = txnClass.cast(transaction.unbox());
 			if (transaction.isCommitted()) {
-				for (Event e : transaction.getEvents()) eventBus.broadcast(e);
+				for (CommitAction a : transaction.getActions())
+					a.accept(visitor);
 			} else {
 				db.abortTransaction(txn);
 			}
@@ -976,4 +986,17 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 				db.updateTransportKeys(txn, ks);
 		}
 	}
+
+	private class CommitActionVisitor implements Visitor {
+
+		@Override
+		public void visit(EventAction a) {
+			eventBus.broadcast(a.getEvent());
+		}
+
+		@Override
+		public void visit(TaskAction a) {
+			eventExecutor.execute(a.getTask());
+		}
+	}
 }

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

@@ -3,11 +3,13 @@ package org.briarproject.bramble.db;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DatabaseConfig;
 import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.event.EventExecutor;
 import org.briarproject.bramble.api.lifecycle.ShutdownManager;
 import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.system.Clock;
 
 import java.sql.Connection;
+import java.util.concurrent.Executor;
 
 import javax.inject.Singleton;
 
@@ -27,8 +29,9 @@ public class DatabaseModule {
 	@Provides
 	@Singleton
 	DatabaseComponent provideDatabaseComponent(Database<Connection> db,
-			EventBus eventBus, ShutdownManager shutdown) {
+			EventBus eventBus, @EventExecutor Executor eventExecutor,
+			ShutdownManager shutdownManager) {
 		return new DatabaseComponentImpl<>(db, Connection.class, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 	}
 }

bramble-core/src/test/java/org/briarproject/bramble/db/DatabaseComponentImplTest.java

@@ -55,6 +55,7 @@ import org.junit.Test;
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.concurrent.Executor;
 import java.util.concurrent.atomic.AtomicReference;
 
 import static java.util.Arrays.asList;
@@ -87,9 +88,10 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 
 	@SuppressWarnings("unchecked")
 	private final Database<Object> database = context.mock(Database.class);
-	private final ShutdownManager shutdown =
+	private final ShutdownManager shutdownManager =
 			context.mock(ShutdownManager.class);
 	private final EventBus eventBus = context.mock(EventBus.class);
+	private final Executor eventExecutor = context.mock(Executor.class);
 
 	private final SecretKey key = getSecretKey();
 	private final Object txn = new Object();
@@ -132,9 +134,10 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 	}
 
 	private DatabaseComponent createDatabaseComponent(Database<Object> database,
-			EventBus eventBus, ShutdownManager shutdown) {
+			EventBus eventBus, Executor eventExecutor,
+			ShutdownManager shutdownManager) {
 		return new DatabaseComponentImpl<>(database, Object.class, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 	}
 
 	@Test
@@ -144,7 +147,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			// open()
 			oneOf(database).open(key, null);
 			will(returnValue(false));
-			oneOf(shutdown).addShutdownHook(with(any(Runnable.class)));
+			oneOf(shutdownManager).addShutdownHook(with(any(Runnable.class)));
 			will(returnValue(shutdownHandle));
 			// startTransaction()
 			oneOf(database).startTransaction();
@@ -207,7 +210,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).close();
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		assertFalse(db.open(key, null));
 		db.transaction(false, transaction -> {
@@ -238,7 +241,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).abortTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction ->
 				db.addLocalMessage(transaction, message, metadata, true));
@@ -263,7 +266,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(eventBus).broadcast(with(any(MessageSharedEvent.class)));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction ->
 				db.addLocalMessage(transaction, message, metadata, true));
@@ -281,7 +284,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			exactly(17).of(database).abortTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		try {
 			db.transaction(false, transaction ->
@@ -438,7 +441,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			exactly(3).of(database).abortTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		try {
 			db.transaction(false, transaction ->
@@ -481,7 +484,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			will(returnValue(true));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		try {
 			db.transaction(false, transaction ->
@@ -565,7 +568,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			will(returnValue(true));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		try {
 			db.transaction(false, transaction ->
@@ -668,7 +671,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			exactly(5).of(database).abortTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		try {
 			db.transaction(false, transaction ->
@@ -727,7 +730,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).commitTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction -> {
 			Ack a = db.generateAck(transaction, contactId, 123);
@@ -761,7 +764,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(eventBus).broadcast(with(any(MessagesSentEvent.class)));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction ->
 				assertEquals(messages, db.generateBatch(transaction, contactId,
@@ -786,7 +789,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).commitTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction -> {
 			Offer o = db.generateOffer(transaction, contactId, 123, maxLatency);
@@ -810,7 +813,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).commitTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction -> {
 			Request r = db.generateRequest(transaction, contactId, 123);
@@ -844,7 +847,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(eventBus).broadcast(with(any(MessagesSentEvent.class)));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction ->
 				assertEquals(messages, db.generateRequestedBatch(transaction,
@@ -865,7 +868,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(eventBus).broadcast(with(any(MessagesAckedEvent.class)));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction -> {
 			Ack a = new Ack(singletonList(messageId));
@@ -903,7 +906,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(eventBus).broadcast(with(any(MessageToAckEvent.class)));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction -> {
 			// Receive the message twice
@@ -931,7 +934,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(eventBus).broadcast(with(any(MessageToAckEvent.class)));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction ->
 				db.receiveMessage(transaction, contactId, message));
@@ -949,7 +952,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).commitTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction ->
 				db.receiveMessage(transaction, contactId, message));
@@ -989,7 +992,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(eventBus).broadcast(with(any(MessageToRequestEvent.class)));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		Offer o = new Offer(asList(messageId, messageId1,
 				messageId2, messageId3));
@@ -1012,7 +1015,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(eventBus).broadcast(with(any(MessageRequestedEvent.class)));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		Request r = new Request(singletonList(messageId));
 		db.transaction(false, transaction ->
@@ -1042,7 +1045,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 					GroupVisibilityUpdatedEvent.class, 0));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction ->
 				db.setGroupVisibility(transaction, contactId, groupId,
@@ -1076,7 +1079,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 					GroupVisibilityUpdatedEvent.class, 0));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction ->
 				db.setGroupVisibility(transaction, contactId, groupId,
@@ -1102,7 +1105,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).commitTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction ->
 				db.setGroupVisibility(transaction, contactId, groupId,
@@ -1132,7 +1135,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).commitTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction -> {
 			db.updateTransportKeys(transaction, keys);
@@ -1171,7 +1174,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).commitTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(true, transaction -> {
 			// With visible group - return stored status
@@ -1221,7 +1224,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).commitTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(true, transaction -> {
 			// With visible group - return stored status
@@ -1287,7 +1290,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		}});
 
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction -> {
 			// First merge should broadcast an event
@@ -1330,7 +1333,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		}});
 
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		assertNotNull(db.startTransaction(firstTxnReadOnly));
 		db.startTransaction(secondTxnReadOnly);
@@ -1351,7 +1354,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		}});
 
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		try {
 			db.transaction(false, transaction ->
@@ -1380,7 +1383,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		}});
 
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		try {
 			db.transaction(false, transaction ->
@@ -1401,7 +1404,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			// open()
 			oneOf(database).open(key, null);
 			will(returnValue(false));
-			oneOf(shutdown).addShutdownHook(with(any(Runnable.class)));
+			oneOf(shutdownManager).addShutdownHook(with(any(Runnable.class)));
 			will(returnValue(shutdownHandle));
 			// startTransaction()
 			oneOf(database).startTransaction();
@@ -1441,7 +1444,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).close();
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		assertFalse(db.open(key, null));
 		db.transaction(false, transaction -> {

briar-core/src/test/java/org/briarproject/briar/blog/BlogManagerImplTest.java

@@ -9,9 +9,12 @@ 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.CommitAction;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.db.EventAction;
 import org.briarproject.bramble.api.db.Transaction;
+import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorInfo;
 import org.briarproject.bramble.api.identity.IdentityManager;
@@ -188,10 +191,12 @@ public class BlogManagerImplTest extends BriarTestCase {
 		blogManager.incomingMessage(txn, message, body, meta);
 		context.assertIsSatisfied();
 
-		assertEquals(1, txn.getEvents().size());
-		assertTrue(txn.getEvents().get(0) instanceof BlogPostAddedEvent);
-
-		BlogPostAddedEvent e = (BlogPostAddedEvent) txn.getEvents().get(0);
+		assertEquals(1, txn.getActions().size());
+		CommitAction action = txn.getActions().get(0);
+		assertTrue(action instanceof EventAction);
+		Event event = ((EventAction) action).getEvent();
+		assertTrue(event instanceof BlogPostAddedEvent);
+		BlogPostAddedEvent e = (BlogPostAddedEvent) event;
 		assertEquals(blog1.getId(), e.getGroupId());
 
 		BlogPostHeader h = e.getHeader();
@@ -227,10 +232,12 @@ public class BlogManagerImplTest extends BriarTestCase {
 		blogManager.incomingMessage(txn, rssMessage, body, meta);
 		context.assertIsSatisfied();
 
-		assertEquals(1, txn.getEvents().size());
-		assertTrue(txn.getEvents().get(0) instanceof BlogPostAddedEvent);
-
-		BlogPostAddedEvent e = (BlogPostAddedEvent) txn.getEvents().get(0);
+		assertEquals(1, txn.getActions().size());
+		CommitAction action = txn.getActions().get(0);
+		assertTrue(action instanceof EventAction);
+		Event event = ((EventAction) action).getEvent();
+		assertTrue(event instanceof BlogPostAddedEvent);
+		BlogPostAddedEvent e = (BlogPostAddedEvent) event;
 		assertEquals(rssBlog.getId(), e.getGroupId());
 
 		BlogPostHeader h = e.getHeader();
@@ -296,10 +303,12 @@ public class BlogManagerImplTest extends BriarTestCase {
 		blogManager.addLocalPost(post);
 		context.assertIsSatisfied();
 
-		assertEquals(1, txn.getEvents().size());
-		assertTrue(txn.getEvents().get(0) instanceof BlogPostAddedEvent);
-
-		BlogPostAddedEvent e = (BlogPostAddedEvent) txn.getEvents().get(0);
+		assertEquals(1, txn.getActions().size());
+		CommitAction action = txn.getActions().get(0);
+		assertTrue(action instanceof EventAction);
+		Event event = ((EventAction) action).getEvent();
+		assertTrue(event instanceof BlogPostAddedEvent);
+		BlogPostAddedEvent e = (BlogPostAddedEvent) event;
 		assertEquals(blog1.getId(), e.getGroupId());
 
 		BlogPostHeader h = e.getHeader();
@@ -344,10 +353,12 @@ public class BlogManagerImplTest extends BriarTestCase {
 		blogManager.addLocalPost(post);
 		context.assertIsSatisfied();
 
-		assertEquals(1, txn.getEvents().size());
-		assertTrue(txn.getEvents().get(0) instanceof BlogPostAddedEvent);
-
-		BlogPostAddedEvent e = (BlogPostAddedEvent) txn.getEvents().get(0);
+		assertEquals(1, txn.getActions().size());
+		CommitAction action = txn.getActions().get(0);
+		assertTrue(action instanceof EventAction);
+		Event event = ((EventAction) action).getEvent();
+		assertTrue(event instanceof BlogPostAddedEvent);
+		BlogPostAddedEvent e = (BlogPostAddedEvent) event;
 		assertEquals(rssBlog.getId(), e.getGroupId());
 
 		BlogPostHeader h = e.getHeader();
@@ -421,10 +432,12 @@ public class BlogManagerImplTest extends BriarTestCase {
 				postHeader);
 		context.assertIsSatisfied();
 
-		assertEquals(1, txn.getEvents().size());
-		assertTrue(txn.getEvents().get(0) instanceof BlogPostAddedEvent);
-
-		BlogPostAddedEvent e = (BlogPostAddedEvent) txn.getEvents().get(0);
+		assertEquals(1, txn.getActions().size());
+		CommitAction action = txn.getActions().get(0);
+		assertTrue(action instanceof EventAction);
+		Event event = ((EventAction) action).getEvent();
+		assertTrue(event instanceof BlogPostAddedEvent);
+		BlogPostAddedEvent e = (BlogPostAddedEvent) event;
 		assertEquals(blog1.getId(), e.getGroupId());
 
 		BlogPostHeader h = e.getHeader();
@@ -530,10 +543,12 @@ public class BlogManagerImplTest extends BriarTestCase {
 				originalPostHeader);
 		context.assertIsSatisfied();
 
-		assertEquals(1, txn.getEvents().size());
-		assertTrue(txn.getEvents().get(0) instanceof BlogPostAddedEvent);
-
-		BlogPostAddedEvent e = (BlogPostAddedEvent) txn.getEvents().get(0);
+		assertEquals(1, txn.getActions().size());
+		CommitAction action = txn.getActions().get(0);
+		assertTrue(action instanceof EventAction);
+		Event event = ((EventAction) action).getEvent();
+		assertTrue(event instanceof BlogPostAddedEvent);
+		BlogPostAddedEvent e = (BlogPostAddedEvent) event;
 		assertEquals(blog2.getId(), e.getGroupId());
 
 		BlogPostHeader h = e.getHeader();
@@ -637,10 +652,12 @@ public class BlogManagerImplTest extends BriarTestCase {
 				originalPostHeader);
 		context.assertIsSatisfied();
 
-		assertEquals(1, txn.getEvents().size());
-		assertTrue(txn.getEvents().get(0) instanceof BlogPostAddedEvent);
-
-		BlogPostAddedEvent e = (BlogPostAddedEvent) txn.getEvents().get(0);
+		assertEquals(1, txn.getActions().size());
+		CommitAction action = txn.getActions().get(0);
+		assertTrue(action instanceof EventAction);
+		Event event = ((EventAction) action).getEvent();
+		assertTrue(event instanceof BlogPostAddedEvent);
+		BlogPostAddedEvent e = (BlogPostAddedEvent) event;
 		assertEquals(blog1.getId(), e.getGroupId());
 
 		BlogPostHeader h = e.getHeader();
@@ -787,10 +804,12 @@ public class BlogManagerImplTest extends BriarTestCase {
 				originalCommentHeader);
 		context.assertIsSatisfied();
 
-		assertEquals(1, txn.getEvents().size());
-		assertTrue(txn.getEvents().get(0) instanceof BlogPostAddedEvent);
-
-		BlogPostAddedEvent e = (BlogPostAddedEvent) txn.getEvents().get(0);
+		assertEquals(1, txn.getActions().size());
+		CommitAction action = txn.getActions().get(0);
+		assertTrue(action instanceof EventAction);
+		Event event = ((EventAction) action).getEvent();
+		assertTrue(event instanceof BlogPostAddedEvent);
+		BlogPostAddedEvent e = (BlogPostAddedEvent) event;
 		assertEquals(blog2.getId(), e.getGroupId());
 
 		BlogPostHeader h = e.getHeader();