Use ConversationManager to retrieve messages

This removes the public method for retrieving messages
from individual conversation clients
and just leaves methods that require a transaction
to be used by the ConversationManager only.

briar-android/src/main/java/org/briarproject/briar/android/contact/ConversationActivity.java

@@ -62,8 +62,8 @@ import org.briarproject.briar.api.client.ProtocolStateException;
 import org.briarproject.briar.api.client.SessionId;
 import org.briarproject.briar.api.forum.ForumSharingManager;
 import org.briarproject.briar.api.introduction.IntroductionManager;
-import org.briarproject.briar.api.introduction.IntroductionRequest;
 import org.briarproject.briar.api.introduction.IntroductionResponse;
+import org.briarproject.briar.api.messaging.ConversationManager;
 import org.briarproject.briar.api.messaging.MessagingManager;
 import org.briarproject.briar.api.messaging.PrivateMessage;
 import org.briarproject.briar.api.messaging.PrivateMessageFactory;
@@ -159,6 +159,8 @@ public class ConversationActivity extends BriarActivity
 	@Inject
 	volatile MessagingManager messagingManager;
 	@Inject
+	volatile ConversationManager conversationManager;
+	@Inject
 	volatile EventBus eventBus;
 	@Inject
 	volatile SettingsManager settingsManager;
@@ -337,23 +339,9 @@ public class ConversationActivity extends BriarActivity
 			try {
 				long start = now();
 				Collection<PrivateMessageHeader> headers =
-						messagingManager.getMessages(contactId);
+						conversationManager.getMessageHeaders(contactId);
-				Collection<PrivateMessageHeader> introductions =
-						introductionManager.getMessages(contactId);
-				Collection<PrivateMessageHeader> forumInvitations =
-						forumSharingManager.getMessages(contactId);
-				Collection<PrivateMessageHeader> blogInvitations =
-						blogSharingManager.getMessages(contactId);
-				Collection<PrivateMessageHeader> groupInvitations =
-						groupInvitationManager.getMessages(contactId);
-				List<PrivateMessageHeader> invitations = new ArrayList<>(
-						forumInvitations.size() + blogInvitations.size() +
-								groupInvitations.size());
-				invitations.addAll(forumInvitations);
-				invitations.addAll(blogInvitations);
-				invitations.addAll(groupInvitations);
 				logDuration(LOG, "Loading messages", start);
-				displayMessages(revision, headers, introductions, invitations);
+				displayMessages(revision, headers);
 			} catch (NoSuchContactException e) {
 				finishOnUiThread();
 			} catch (DbException e) {
@@ -363,15 +351,12 @@ public class ConversationActivity extends BriarActivity
 	}
 
 	private void displayMessages(int revision,
-			Collection<PrivateMessageHeader> headers,
+			Collection<PrivateMessageHeader> headers) {
-			Collection<PrivateMessageHeader> introductions,
-			Collection<PrivateMessageHeader> invitations) {
 		runOnUiThreadUnlessDestroyed(() -> {
 			if (revision == adapter.getRevision()) {
 				adapter.incrementRevision();
 				textInputView.setSendButtonEnabled(true);
-				List<ConversationItem> items = createItems(headers,
+				List<ConversationItem> items = createItems(headers);
-						introductions, invitations);
 				adapter.addAll(items);
 				list.showData();
 				// Scroll to the bottom
@@ -390,38 +375,24 @@ public class ConversationActivity extends BriarActivity
 	 */
 	@SuppressWarnings("ConstantConditions")
 	private List<ConversationItem> createItems(
-			Collection<PrivateMessageHeader> headers,
+			Collection<PrivateMessageHeader> headers) {
-			Collection<PrivateMessageHeader> introductions,
+		List<ConversationItem> items = new ArrayList<>(headers.size());
-			Collection<PrivateMessageHeader> invitations) {
-		int size =
-				headers.size() + introductions.size() + invitations.size();
-		List<ConversationItem> items = new ArrayList<>(size);
 		for (PrivateMessageHeader h : headers) {
-			ConversationItem item = ConversationItem.from(h);
-			String body = bodyCache.get(h.getId());
-			if (body == null) loadMessageBody(h.getId());
-			else item.setBody(body);
-			items.add(item);
-		}
-		for (PrivateMessageHeader m : introductions) {
 			ConversationItem item;
-			if (m instanceof IntroductionRequest) {
+			if (h instanceof IntroductionResponse) {
-				IntroductionRequest i = (IntroductionRequest) m;
+				IntroductionResponse i = (IntroductionResponse) h;
 				item = ConversationItem.from(this, contactName, i);
-			} else {
+			} else if (h instanceof PrivateRequest) {
-				IntroductionResponse i = (IntroductionResponse) m;
+				PrivateRequest r = (PrivateRequest) h;
-				item = ConversationItem.from(this, contactName, i);
-			}
-			items.add(item);
-		}
-		for (PrivateMessageHeader i : invitations) {
-			ConversationItem item;
-			if (i instanceof PrivateRequest) {
-				item = ConversationItem
-						.from(this, contactName, (PrivateRequest) i);
-			} else {
-				PrivateResponse r = (PrivateResponse) i;
 				item = ConversationItem.from(this, contactName, r);
+			} else if (h instanceof PrivateResponse) {
+				PrivateResponse r = (PrivateResponse) h;
+				item = ConversationItem.from(this, contactName, r);
+			} else {
+				item = ConversationItem.from(h);
+				String body = bodyCache.get(h.getId());
+				if (body == null) loadMessageBody(h.getId());
+				else item.setBody(body);
 			}
 			items.add(item);
 		}
@@ -513,9 +484,9 @@ public class ConversationActivity extends BriarActivity
 			getContactNameTask().addListener(new FutureTaskListener<String>() {
 				@Override
 				public void onSuccess(String contactName) {
-					runOnUiThreadUnlessDestroyed(() -> {
+					runOnUiThreadUnlessDestroyed(
-						handlePrivateRequestAndResponse(h, contactName);
+							() -> handlePrivateRequestAndResponse(h,
-					});
+									contactName));
 				}
 
 				@Override

briar-android/src/main/java/org/briarproject/briar/android/contact/ConversationItem.java

@@ -34,7 +34,8 @@ import static org.briarproject.briar.android.contact.ConversationRequestItem.Req
 @NotNullByDefault
 abstract class ConversationItem {
 
-	protected @Nullable String body;
+	@Nullable
+	protected String body;
 	private final MessageId id;
 	private final GroupId groupId;
 	private final long time;
@@ -105,7 +106,7 @@ abstract class ConversationItem {
 						R.string.groups_invitations_invitation_sent,
 						contactName, ir.getName());
 			} else {
-				throw new IllegalArgumentException("Unknown InvitationRequest");
+				throw new IllegalArgumentException("Unknown PrivateRequest");
 			}
 			return new ConversationNoticeOutItem(ir.getId(), ir.getGroupId(),
 					text, ir.getMessage(), ir.getTimestamp(), ir.isSent(),
@@ -145,7 +146,7 @@ abstract class ConversationItem {
 						contactName, ir.getName());
 				type = GROUP;
 			} else {
-				throw new IllegalArgumentException("Unknown InvitationRequest");
+				throw new IllegalArgumentException("Unknown PrivateRequest");
 			}
 			return new ConversationRequestItem(ir.getId(),
 					ir.getGroupId(), type, ir.getSessionId(), text,
@@ -229,22 +230,24 @@ abstract class ConversationItem {
 				} else if (ir instanceof BlogInvitationResponse) {
 					res = R.string.blogs_sharing_response_accepted_received;
 				} else if (ir instanceof GroupInvitationResponse) {
-					res = R.string.groups_invitations_response_accepted_received;
+					res =
+							R.string.groups_invitations_response_accepted_received;
 				} else {
 					throw new IllegalArgumentException(
 							"Unknown PrivateResponse");
 				}
 			} else {
-					if (ir instanceof ForumInvitationResponse) {
+				if (ir instanceof ForumInvitationResponse) {
-						res = R.string.forum_invitation_response_declined_received;
+					res = R.string.forum_invitation_response_declined_received;
-					} else if (ir instanceof BlogInvitationResponse) {
+				} else if (ir instanceof BlogInvitationResponse) {
-						res = R.string.blogs_sharing_response_declined_received;
+					res = R.string.blogs_sharing_response_declined_received;
-					} else if (ir instanceof GroupInvitationResponse) {
+				} else if (ir instanceof GroupInvitationResponse) {
-						res = R.string.groups_invitations_response_declined_received;
+					res =
-					} else {
+							R.string.groups_invitations_response_declined_received;
-						throw new IllegalArgumentException(
+				} else {
-								"Unknown PrivateResponse");
+					throw new IllegalArgumentException(
-					}
+							"Unknown PrivateResponse");
+				}
 			}
 			String text = ctx.getString(res, contactName);
 			return new ConversationNoticeInItem(ir.getId(), ir.getGroupId(),
@@ -258,11 +261,11 @@ abstract class ConversationItem {
 	 * PrivateMessageHeader.
 	 **/
 	static ConversationItem from(Context ctx, PrivateMessageHeader h) {
-		if(h instanceof IntroductionResponse) {
+		if (h instanceof IntroductionResponse) {
 			return from(ctx, "", (IntroductionResponse) h);
-		} else if(h instanceof PrivateRequest) {
+		} else if (h instanceof PrivateRequest) {
 			return from(ctx, "", (PrivateRequest) h);
-		} else if(h instanceof PrivateResponse) {
+		} else if (h instanceof PrivateResponse) {
 			return from(ctx, "", (PrivateResponse) h);
 		} else {
 			return from(h);

briar-api/src/main/java/org/briarproject/briar/api/introduction/IntroductionManager.java

@@ -7,9 +7,6 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.ClientId;
 import org.briarproject.briar.api.client.SessionId;
 import org.briarproject.briar.api.messaging.ConversationManager.ConversationClient;
-import org.briarproject.briar.api.messaging.PrivateMessageHeader;
-
-import java.util.Collection;
 
 import javax.annotation.Nullable;
 
@@ -48,11 +45,4 @@ public interface IntroductionManager extends ConversationClient {
 	void respondToIntroduction(ContactId contactId, SessionId sessionId,
 			long timestamp, boolean accept) throws DbException;
 
-	/**
-	 * Returns all introduction messages for the given contact.
-	 */
-	@Deprecated
-	Collection<PrivateMessageHeader> getMessages(ContactId contactId)
-			throws DbException;
-
 }

briar-api/src/main/java/org/briarproject/briar/api/messaging/ConversationManager.java

@@ -22,12 +22,12 @@ public interface ConversationManager {
 	void registerConversationClient(ConversationClient client);
 
 	/**
-	 * Returns (the headers) of all messages in the given private conversation.
+	 * Returns the headers of all messages in the given private conversation.
 	 *
 	 * Only {@link MessagingManager} returns only headers.
 	 * The others also return the message body.
 	 */
-	Collection<PrivateMessageHeader> getMessages(ContactId c)
+	Collection<PrivateMessageHeader> getMessageHeaders(ContactId c)
 			throws DbException;
 
 	/**
@@ -40,7 +40,7 @@ public interface ConversationManager {
 
 		Group getContactGroup(Contact c);
 
-		Collection<PrivateMessageHeader> getMessages(Transaction txn,
+		Collection<PrivateMessageHeader> getMessageHeaders(Transaction txn,
 				ContactId contactId) throws DbException;
 
 		GroupCount getGroupCount(Transaction txn, ContactId c)

briar-api/src/main/java/org/briarproject/briar/api/messaging/MessagingManager.java

@@ -8,8 +8,6 @@ import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.api.messaging.ConversationManager.ConversationClient;
 
-import java.util.Collection;
-
 @NotNullByDefault
 public interface MessagingManager extends ConversationClient {
 
@@ -43,13 +41,6 @@ public interface MessagingManager extends ConversationClient {
 	 */
 	GroupId getConversationId(ContactId c) throws DbException;
 
-	/**
-	 * Returns the headers of all messages in the given private conversation.
-	 */
-	@Deprecated
-	Collection<PrivateMessageHeader> getMessages(ContactId c)
-			throws DbException;
-
 	/**
 	 * Returns the body of the private message with the given ID.
 	 */

briar-api/src/main/java/org/briarproject/briar/api/privategroup/invitation/GroupInvitationManager.java

@@ -9,7 +9,6 @@ import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.briar.api.client.ProtocolStateException;
 import org.briarproject.briar.api.client.SessionId;
 import org.briarproject.briar.api.messaging.ConversationManager.ConversationClient;
-import org.briarproject.briar.api.messaging.PrivateMessageHeader;
 import org.briarproject.briar.api.privategroup.PrivateGroup;
 
 import java.util.Collection;
@@ -73,14 +72,6 @@ public interface GroupInvitationManager extends ConversationClient {
 	 */
 	void revealRelationship(ContactId c, GroupId g) throws DbException;
 
-	/**
-	 * Returns all private group invitation messages related to the given
-	 * contact.
-	 */
-	@Deprecated
-	Collection<PrivateMessageHeader> getMessages(ContactId c)
-			throws DbException;
-
 	/**
 	 * Returns all private groups to which the user has been invited.
 	 */

briar-api/src/main/java/org/briarproject/briar/api/sharing/SharingManager.java

@@ -7,7 +7,6 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.briar.api.client.SessionId;
 import org.briarproject.briar.api.messaging.ConversationManager.ConversationClient;
-import org.briarproject.briar.api.messaging.PrivateMessageHeader;
 
 import java.util.Collection;
 
@@ -36,14 +35,6 @@ public interface SharingManager<S extends Shareable>
 	void respondToInvitation(ContactId c, SessionId id, boolean accept)
 			throws DbException;
 
-	/**
-	 * Returns all group sharing messages sent by the Contact
-	 * identified by contactId.
-	 */
-	@Deprecated
-	Collection<PrivateMessageHeader> getMessages(ContactId contactId)
-			throws DbException;
-
 	/**
 	 * Returns all invitations to groups.
 	 */

briar-core/src/main/java/org/briarproject/briar/introduction/IntroductionManagerImpl.java

@@ -399,21 +399,7 @@ class IntroductionManagerImpl extends ConversationClientImpl
 	}
 
 	@Override
-	public Collection<PrivateMessageHeader> getMessages(ContactId c)
+	public Collection<PrivateMessageHeader> getMessageHeaders(Transaction txn,
-			throws DbException {
-		Collection<PrivateMessageHeader> messages;
-		Transaction txn = db.startTransaction(true);
-		try {
-			messages = getMessages(txn, c);
-			db.commitTransaction(txn);
-		} finally {
-			db.endTransaction(txn);
-		}
-		return messages;
-	}
-
-	@Override
-	public Collection<PrivateMessageHeader> getMessages(Transaction txn,
 			ContactId c) throws DbException {
 		try {
 			Contact contact = db.getContact(txn, c);

briar-core/src/main/java/org/briarproject/briar/messaging/ConversationManagerImpl.java

@@ -38,13 +38,13 @@ class ConversationManagerImpl implements ConversationManager {
 	}
 
 	@Override
-	public Collection<PrivateMessageHeader> getMessages(ContactId c)
+	public Collection<PrivateMessageHeader> getMessageHeaders(ContactId c)
 			throws DbException {
 		List<PrivateMessageHeader> messages = new ArrayList<>();
 		Transaction txn = db.startTransaction(true);
 		try {
 			for (ConversationClient client : clients) {
-				messages.addAll(client.getMessages(txn, c));
+				messages.addAll(client.getMessageHeaders(txn, c));
 			}
 			db.commitTransaction(txn);
 		} finally {

briar-core/src/main/java/org/briarproject/briar/messaging/MessagingManagerImpl.java

@@ -178,21 +178,7 @@ class MessagingManagerImpl extends ConversationClientImpl
 	}
 
 	@Override
-	public Collection<PrivateMessageHeader> getMessages(ContactId c)
+	public Collection<PrivateMessageHeader> getMessageHeaders(Transaction txn,
-			throws DbException {
-		Collection<PrivateMessageHeader> headers;
-		Transaction txn = db.startTransaction(true);
-		try {
-			headers = getMessages(txn, c);
-			db.commitTransaction(txn);
-		} finally {
-			db.endTransaction(txn);
-		}
-		return headers;
-	}
-
-	@Override
-	public Collection<PrivateMessageHeader> getMessages(Transaction txn,
 			ContactId c) throws DbException {
 		Map<MessageId, BdfDictionary> metadata;
 		Collection<MessageStatus> statuses;

briar-core/src/main/java/org/briarproject/briar/privategroup/invitation/GroupInvitationManagerImpl.java

@@ -368,21 +368,7 @@ class GroupInvitationManagerImpl extends ConversationClientImpl
 	}
 
 	@Override
-	public Collection<PrivateMessageHeader> getMessages(ContactId c)
+	public Collection<PrivateMessageHeader> getMessageHeaders(Transaction txn,
-			throws DbException {
-		Collection<PrivateMessageHeader> messages;
-		Transaction txn = db.startTransaction(true);
-		try {
-			messages = getMessages(txn, c);
-			db.commitTransaction(txn);
-		} finally {
-			db.endTransaction(txn);
-		}
-		return messages;
-	}
-
-	@Override
-	public Collection<PrivateMessageHeader> getMessages(Transaction txn,
 			ContactId c) throws DbException {
 		try {
 			Contact contact = db.getContact(txn, c);

briar-core/src/main/java/org/briarproject/briar/sharing/SharingManagerImpl.java

@@ -321,21 +321,7 @@ abstract class SharingManagerImpl<S extends Shareable>
 	}
 
 	@Override
-	public Collection<PrivateMessageHeader> getMessages(ContactId c)
+	public Collection<PrivateMessageHeader> getMessageHeaders(Transaction txn,
-			throws DbException {
-		Collection<PrivateMessageHeader> messages;
-		Transaction txn = db.startTransaction(true);
-		try {
-			messages = getMessages(txn, c);
-			db.commitTransaction(txn);
-		} finally {
-			db.endTransaction(txn);
-		}
-		return messages;
-	}
-
-	@Override
-	public Collection<PrivateMessageHeader> getMessages(Transaction txn,
 			ContactId c) throws DbException {
 		try {
 			Contact contact = db.getContact(txn, c);

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

@@ -1,6 +1,5 @@
 package org.briarproject.briar.blog;
 
-import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.LocalAuthor;
 import org.briarproject.bramble.api.sync.MessageId;
@@ -63,10 +62,7 @@ public class BlogManagerIntegrationTest
 		blog1 = blogFactory.createBlog(author1);
 
 		rssBlog = blogFactory.createFeedBlog(rssAuthor);
-		Transaction txn = db0.startTransaction(false);
+		withinTransaction(db0, txn -> blogManager0.addBlog(txn, rssBlog));
-		blogManager0.addBlog(txn, rssBlog);
-		db0.commitTransaction(txn);
-		db0.endTransaction(txn);
 	}
 
 	@Override

briar-core/src/test/java/org/briarproject/briar/introduction/IntroductionIntegrationTest.java

@@ -9,8 +9,8 @@ import org.briarproject.bramble.api.contact.ContactId;
 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.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.identity.Author;
@@ -299,18 +299,23 @@ public class IntroductionIntegrationTest
 
 		Group g1 = introductionManager0.getContactGroup(introducee1);
 		Group g2 = introductionManager0.getContactGroup(introducee2);
-		assertEquals(2,
+		Collection<PrivateMessageHeader> messages =
-				introductionManager0.getMessages(contactId1From0).size());
+				withinTransactionReturns(db0, txn -> introductionManager0
+						.getMessageHeaders(txn, contactId1From0));
+		assertEquals(2, messages.size());
 		assertGroupCount(messageTracker0, g1.getId(), 2, 1);
-		assertEquals(2,
+		messages = withinTransactionReturns(db0,
-				introductionManager0.getMessages(contactId2From0).size());
+				txn -> introductionManager0.getMessageHeaders(txn, contactId2From0));
+		assertEquals(2, messages.size());
 		assertGroupCount(messageTracker0, g2.getId(), 2, 1);
-		assertEquals(2,
+		messages = withinTransactionReturns(db1,
-				introductionManager1.getMessages(contactId0From1).size());
+				txn -> introductionManager1.getMessageHeaders(txn, contactId0From1));
+		assertEquals(2, messages.size());
 		assertGroupCount(messageTracker1, g1.getId(), 2, 1);
 		// introducee2 should also have the decline response of introducee1
-		assertEquals(3,
+		messages = withinTransactionReturns(db2,
-				introductionManager2.getMessages(contactId0From2).size());
+				txn -> introductionManager2.getMessageHeaders(txn, contactId0From2));
+		assertEquals(3, messages.size());
 		assertGroupCount(messageTracker2, g2.getId(), 3, 2);
 
 		assertFalse(listener0.aborted);
@@ -360,15 +365,19 @@ public class IntroductionIntegrationTest
 		assertFalse(contactManager2
 				.contactExists(author1.getId(), author2.getId()));
 
-		assertEquals(2,
+		Collection<PrivateMessageHeader> messages =
-				introductionManager0.getMessages(contactId1From0).size());
+				withinTransactionReturns(db0, txn -> introductionManager0
-		assertEquals(2,
+						.getMessageHeaders(txn, contactId1From0));
-				introductionManager0.getMessages(contactId2From0).size());
+		assertEquals(2, messages.size());
-		assertEquals(3,
+		messages = withinTransactionReturns(db0,
-				introductionManager1.getMessages(contactId0From1).size());
+				txn -> introductionManager0.getMessageHeaders(txn, contactId2From0));
-		assertEquals(3,
+		assertEquals(2, messages.size());
-				introductionManager2.getMessages(contactId0From2)
+		messages = withinTransactionReturns(db1,
-						.size());
+				txn -> introductionManager1.getMessageHeaders(txn, contactId0From1));
+		assertEquals(3,messages.size());
+		messages = withinTransactionReturns(db2,
+				txn -> introductionManager2.getMessageHeaders(txn, contactId0From2));
+		assertEquals(3, messages.size());
 		assertFalse(listener0.aborted);
 		assertFalse(listener1.aborted);
 		assertFalse(listener2.aborted);
@@ -514,17 +523,21 @@ public class IntroductionIntegrationTest
 
 		Group g1 = introductionManager0.getContactGroup(introducee1);
 		Group g2 = introductionManager0.getContactGroup(introducee2);
-		assertEquals(2,
+		assertEquals(2, withinTransactionReturns(db0,
-				introductionManager0.getMessages(contactId1From0).size());
+				txn -> introductionManager0.getMessageHeaders(txn, contactId1From0))
+				.size());
 		assertGroupCount(messageTracker0, g1.getId(), 2, 1);
-		assertEquals(2,
+		assertEquals(2, withinTransactionReturns(db0,
-				introductionManager0.getMessages(contactId2From0).size());
+				txn -> introductionManager0.getMessageHeaders(txn, contactId2From0))
+				.size());
 		assertGroupCount(messageTracker0, g2.getId(), 2, 1);
-		assertEquals(3,
+		assertEquals(3, withinTransactionReturns(db1,
-				introductionManager1.getMessages(contactId0From1).size());
+				txn -> introductionManager1.getMessageHeaders(txn, contactId0From1))
+				.size());
 		assertGroupCount(messageTracker1, g1.getId(), 3, 2);
-		assertEquals(3,
+		assertEquals(3, withinTransactionReturns(db2,
-				introductionManager2.getMessages(contactId0From2).size());
+				txn -> introductionManager2.getMessageHeaders(txn, contactId0From2))
+				.size());
 		assertGroupCount(messageTracker2, g2.getId(), 3, 2);
 
 		assertFalse(listener0.aborted);
@@ -548,7 +561,9 @@ public class IntroductionIntegrationTest
 		assertFalse(listener1.requestReceived);
 
 		// make really sure we don't have that request
-		assertTrue(introductionManager1.getMessages(contactId0From1).isEmpty());
+		assertTrue(withinTransactionReturns(db1,
+				txn -> introductionManager1.getMessageHeaders(txn, contactId0From1))
+				.isEmpty());
 
 		// The message was invalid, so no abort message was sent
 		assertFalse(listener0.aborted);
@@ -596,11 +611,11 @@ public class IntroductionIntegrationTest
 		sync0To2(1, true);
 
 		// assert that introducees get notified about the existing contact
-		IntroductionRequest ir1 =
+		IntroductionRequest ir1 = getIntroductionRequest(db1,
-				getIntroductionRequest(introductionManager1, contactId0From1);
+				introductionManager1, contactId0From1);
 		assertTrue(ir1.doesExist());
-		IntroductionRequest ir2 =
+		IntroductionRequest ir2 = getIntroductionRequest(db2,
-				getIntroductionRequest(introductionManager2, contactId0From2);
+				introductionManager2, contactId0From2);
 		assertTrue(ir2.doesExist());
 
 		// sync ACCEPT messages back to introducer
@@ -981,8 +996,7 @@ public class IntroductionIntegrationTest
 		AcceptMessage m = visitor.visit(message);
 
 		// replace original response with modified one
-		Transaction txn = db0.startTransaction(false);
+		withinTransaction(db0, txn -> {
-		try {
 			db0.removeMessage(txn, message.getMessageId());
 			Message msg = c0.getMessageEncoder()
 					.encodeAcceptMessage(m.getGroupId(), m.getTimestamp(),
@@ -1002,10 +1016,7 @@ public class IntroductionIntegrationTest
 					session.getValue(), msg.getId());
 			c0.getClientHelper().mergeMessageMetadata(txn, session.getKey(),
 					session.getValue());
-			db0.commitTransaction(txn);
+		});
-		} finally {
-			db0.endTransaction(txn);
-		}
 
 		// sync second response
 		sync2To0(1, true);
@@ -1091,19 +1102,23 @@ public class IntroductionIntegrationTest
 
 	private void assertDefaultUiMessages() throws DbException {
 		Collection<PrivateMessageHeader> messages =
-				introductionManager0.getMessages(contactId1From0);
+				withinTransactionReturns(db0, txn -> introductionManager0
+						.getMessageHeaders(txn, contactId1From0));
 		assertEquals(2, messages.size());
 		assertMessagesAreAcked(messages);
 
-		messages = introductionManager0.getMessages(contactId2From0);
+		messages = withinTransactionReturns(db0,
+				txn -> introductionManager0.getMessageHeaders(txn, contactId2From0));
 		assertEquals(2, messages.size());
 		assertMessagesAreAcked(messages);
 
-		messages = introductionManager1.getMessages(contactId0From1);
+		messages = withinTransactionReturns(db1,
+				txn -> introductionManager1.getMessageHeaders(txn, contactId0From1));
 		assertEquals(2, messages.size());
 		assertMessagesAreAcked(messages);
 
-		messages = introductionManager2.getMessages(contactId0From2);
+		messages = withinTransactionReturns(db2,
+				txn -> introductionManager2.getMessageHeaders(txn, contactId0From2));
 		assertEquals(2, messages.size());
 		assertMessagesAreAcked(messages);
 	}
@@ -1137,7 +1152,7 @@ public class IntroductionIntegrationTest
 			assertTrue(
 					latestEvent instanceof IntroductionResponseReceivedEvent);
 			return ((IntroductionResponseReceivedEvent) latestEvent)
-					.getResponse();
+					.getMessageHeader();
 		}
 	}
 
@@ -1165,7 +1180,7 @@ public class IntroductionIntegrationTest
 				IntroductionRequestReceivedEvent introEvent =
 						((IntroductionRequestReceivedEvent) e);
 				requestReceived = true;
-				PrivateRequest<Introduction> ir = introEvent.getRequest();
+				PrivateRequest<Introduction> ir = introEvent.getMessageHeader();
 				ContactId contactId = introEvent.getContactId();
 				sessionId = ir.getSessionId();
 				long time = clock.currentTimeMillis();
@@ -1206,7 +1221,7 @@ public class IntroductionIntegrationTest
 			assertTrue(
 					latestEvent instanceof IntroductionRequestReceivedEvent);
 			return ((IntroductionRequestReceivedEvent) latestEvent)
-					.getRequest();
+					.getMessageHeader();
 		}
 	}
 
@@ -1283,10 +1298,12 @@ public class IntroductionIntegrationTest
 		} else throw new AssertionError("Not implemented");
 	}
 
-	private IntroductionRequest getIntroductionRequest(
+	private IntroductionRequest getIntroductionRequest(DatabaseComponent db,
 			IntroductionManager manager, ContactId contactId)
 			throws DbException {
-		for (PrivateMessageHeader im : manager.getMessages(contactId)) {
+		Collection<PrivateMessageHeader> messages = withinTransactionReturns(db,
+				txn -> manager.getMessageHeaders(txn, contactId));
+		for (PrivateMessageHeader im : messages) {
 			if (im instanceof IntroductionRequest) {
 				return (IntroductionRequest) im;
 			}

briar-core/src/test/java/org/briarproject/briar/privategroup/PrivateGroupManagerIntegrationTest.java

@@ -2,7 +2,6 @@ package org.briarproject.briar.privategroup;
 
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.data.BdfList;
-import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.test.TestDatabaseModule;
@@ -245,11 +244,8 @@ public class PrivateGroupManagerIntegrationTest
 				groupManager0.getPreviousMsgId(groupId0));
 
 		// share the group with 1
-		Transaction txn0 = db0.startTransaction(false);
+		withinTransaction(db0, txn -> db0.setGroupVisibility(txn,
-		db0.setGroupVisibility(txn0, contactId1From0, privateGroup0.getId(),
+				contactId1From0, privateGroup0.getId(), SHARED));
-				SHARED);
-		db0.commitTransaction(txn0);
-		db0.endTransaction(txn0);
 
 		// author1 joins privateGroup0 with wrong timestamp
 		joinTime = clock.currentTimeMillis();
@@ -266,11 +262,8 @@ public class PrivateGroupManagerIntegrationTest
 				groupManager1.getPreviousMsgId(groupId0));
 
 		// share the group with 0
-		Transaction txn1 = db1.startTransaction(false);
+		withinTransaction(db1, txn -> db1.setGroupVisibility(txn,
-		db1.setGroupVisibility(txn1, contactId0From1, privateGroup0.getId(),
+				contactId0From1, privateGroup0.getId(), SHARED));
-				SHARED);
-		db1.commitTransaction(txn1);
-		db1.endTransaction(txn1);
 
 		// sync join messages
 		sync0To1(1, false);
@@ -303,11 +296,8 @@ public class PrivateGroupManagerIntegrationTest
 				groupManager0.getPreviousMsgId(groupId0));
 
 		// share the group with 1
-		Transaction txn0 = db0.startTransaction(false);
+		withinTransaction(db0, txn -> db0.setGroupVisibility(txn,
-		db0.setGroupVisibility(txn0, contactId1From0, privateGroup0.getId(),
+				contactId1From0, privateGroup0.getId(), SHARED));
-				SHARED);
-		db0.commitTransaction(txn0);
-		db0.endTransaction(txn0);
 
 		// author1 joins privateGroup0 with wrong signature in join message
 		joinTime = clock.currentTimeMillis();
@@ -325,11 +315,8 @@ public class PrivateGroupManagerIntegrationTest
 				groupManager1.getPreviousMsgId(groupId0));
 
 		// share the group with 0
-		Transaction txn1 = db1.startTransaction(false);
+		withinTransaction(db1, txn -> db1.setGroupVisibility(txn,
-		db1.setGroupVisibility(txn1, contactId0From1, privateGroup0.getId(),
+				contactId0From1, privateGroup0.getId(), SHARED));
-				SHARED);
-		db1.commitTransaction(txn1);
-		db1.endTransaction(txn1);
 
 		// sync join messages
 		sync0To1(1, false);
@@ -404,11 +391,8 @@ public class PrivateGroupManagerIntegrationTest
 		addGroup();
 
 		// share the group with 2
-		Transaction txn0 = db0.startTransaction(false);
+		withinTransaction(db0, txn -> db0.setGroupVisibility(txn,
-		db0.setGroupVisibility(txn0, contactId2From0, privateGroup0.getId(),
+				contactId2From0, privateGroup0.getId(), SHARED));
-				SHARED);
-		db0.commitTransaction(txn0);
-		db0.endTransaction(txn0);
 
 		// author2 joins privateGroup0
 		long joinTime = clock.currentTimeMillis();
@@ -420,14 +404,12 @@ public class PrivateGroupManagerIntegrationTest
 		GroupMessage joinMsg2 = groupMessageFactory
 				.createJoinMessage(privateGroup0.getId(), joinTime, author2,
 						inviteTime, creatorSignature);
-		Transaction txn2 = db2.startTransaction(false);
+		withinTransaction(db2, txn -> {
-		groupManager2.addPrivateGroup(txn2, privateGroup0, joinMsg2, false);
+			groupManager2.addPrivateGroup(txn, privateGroup0, joinMsg2, false);
-
+			// share the group with 0
-		// share the group with 0
+			db2.setGroupVisibility(txn,
-		db2.setGroupVisibility(txn2, contactId0From1, privateGroup0.getId(),
+					contactId0From1, privateGroup0.getId(), SHARED); // TODO contactId
-				SHARED);
+		});
-		db2.commitTransaction(txn2);
-		db2.endTransaction(txn2);
 
 		// sync join messages
 		sync2To0(1, true);
@@ -458,16 +440,10 @@ public class PrivateGroupManagerIntegrationTest
 		}
 
 		// reveal contact relationship
-		Transaction txn1 = db1.startTransaction(false);
+		withinTransaction(db1, txn -> groupManager1.relationshipRevealed(txn,
-		groupManager1
+				groupId0, author2.getId(), false));
-				.relationshipRevealed(txn1, groupId0, author2.getId(), false);
+		withinTransaction(db2, txn -> groupManager2.relationshipRevealed(txn,
-		db1.commitTransaction(txn1);
+				groupId0, author1.getId(), true));
-		db1.endTransaction(txn1);
-		txn2 = db2.startTransaction(false);
-		groupManager2
-				.relationshipRevealed(txn2, groupId0, author1.getId(), true);
-		db2.commitTransaction(txn2);
-		db2.endTransaction(txn2);
 
 		// assert that contact relationship is now revealed properly
 		members1 = groupManager1.getMembers(groupId0);
@@ -520,10 +496,8 @@ public class PrivateGroupManagerIntegrationTest
 		assertFalse(groupManager1.isDissolved(groupId0));
 
 		// creator dissolves group
-		Transaction txn1 = db1.startTransaction(false);
+		withinTransaction(db1,
-		groupManager1.markGroupDissolved(txn1, groupId0);
+				txn -> groupManager1.markGroupDissolved(txn, groupId0));
-		db1.commitTransaction(txn1);
-		db1.endTransaction(txn1);
 
 		// group is dissolved now
 		assertTrue(groupManager1.isDissolved(groupId0));
@@ -539,11 +513,8 @@ public class PrivateGroupManagerIntegrationTest
 				groupManager0.getPreviousMsgId(groupId0));
 
 		// share the group with 1
-		Transaction txn0 = db0.startTransaction(false);
+		withinTransaction(db0, txn -> db0.setGroupVisibility(txn,
-		db0.setGroupVisibility(txn0, contactId1From0, privateGroup0.getId(),
+				contactId1From0, privateGroup0.getId(), SHARED));
-				SHARED);
-		db0.commitTransaction(txn0);
-		db0.endTransaction(txn0);
 
 		// author1 joins privateGroup0
 		joinTime = clock.currentTimeMillis();
@@ -558,11 +529,8 @@ public class PrivateGroupManagerIntegrationTest
 		groupManager1.addPrivateGroup(privateGroup0, joinMsg1, false);
 
 		// share the group with 0
-		Transaction txn1 = db1.startTransaction(false);
+		withinTransaction(db1, txn -> db1.setGroupVisibility(txn,
-		db1.setGroupVisibility(txn1, contactId0From1, privateGroup0.getId(),
+				contactId0From1, privateGroup0.getId(), SHARED));
-				SHARED);
-		db1.commitTransaction(txn1);
-		db1.endTransaction(txn1);
 		assertEquals(joinMsg1.getMessage().getId(),
 				groupManager1.getPreviousMsgId(groupId0));
 

briar-core/src/test/java/org/briarproject/briar/privategroup/invitation/GroupInvitationIntegrationTest.java

@@ -93,7 +93,8 @@ public class GroupInvitationIntegrationTest
 		assertFalse(item.isSubscribed());
 
 		Collection<PrivateMessageHeader> messages =
-				groupInvitationManager1.getMessages(contactId0From1);
+				withinTransactionReturns(db1, txn -> groupInvitationManager1
+						.getMessageHeaders(txn, contactId0From1));
 		assertEquals(1, messages.size());
 		GroupInvitationRequest request =
 				(GroupInvitationRequest) messages.iterator().next();
@@ -118,7 +119,8 @@ public class GroupInvitationIntegrationTest
 				.respondToInvitation(contactId0From1, privateGroup0, false);
 
 		Collection<PrivateMessageHeader> messages =
-				groupInvitationManager1.getMessages(contactId0From1);
+				withinTransactionReturns(db1, txn -> groupInvitationManager1
+						.getMessageHeaders(txn, contactId0From1));
 		assertEquals(2, messages.size());
 		boolean foundResponse = false;
 		for (PrivateMessageHeader m : messages) {
@@ -134,8 +136,8 @@ public class GroupInvitationIntegrationTest
 
 		sync1To0(1, true);
 
-		messages =
+		messages = withinTransactionReturns(db0, txn -> groupInvitationManager0
-				groupInvitationManager0.getMessages(contactId1From0);
+				.getMessageHeaders(txn, contactId1From0));
 		assertEquals(2, messages.size());
 		foundResponse = false;
 		for (PrivateMessageHeader m : messages) {
@@ -167,7 +169,8 @@ public class GroupInvitationIntegrationTest
 				.respondToInvitation(contactId0From1, privateGroup0, true);
 
 		Collection<PrivateMessageHeader> messages =
-				groupInvitationManager1.getMessages(contactId0From1);
+				withinTransactionReturns(db1, txn -> groupInvitationManager1
+						.getMessageHeaders(txn, contactId0From1));
 		assertEquals(2, messages.size());
 		boolean foundResponse = false;
 		for (PrivateMessageHeader m : messages) {
@@ -186,7 +189,8 @@ public class GroupInvitationIntegrationTest
 
 		sync1To0(1, true);
 
-		messages = groupInvitationManager0.getMessages(contactId1From0);
+		messages = withinTransactionReturns(db1, txn -> groupInvitationManager0
+				.getMessageHeaders(txn, contactId1From0));
 		assertEquals(2, messages.size());
 		foundResponse = false;
 		for (PrivateMessageHeader m : messages) {
@@ -221,9 +225,9 @@ public class GroupInvitationIntegrationTest
 		// 1 has one unread message
 		Group g0 = groupInvitationManager1.getContactGroup(contact0From1);
 		assertGroupCount(messageTracker1, g0.getId(), 1, 1, timestamp);
-		PrivateMessageHeader m =
+		PrivateMessageHeader m = withinTransactionReturns(db1,
-				groupInvitationManager1.getMessages(contactId0From1)
+				txn -> groupInvitationManager1.getMessageHeaders(txn, contactId0From1)
-						.iterator().next();
+						.iterator().next());
 
 		groupInvitationManager1
 				.respondToInvitation(contactId0From1, privateGroup0, true);
@@ -445,7 +449,8 @@ public class GroupInvitationIntegrationTest
 
 		// save MessageId of invitation
 		Collection<PrivateMessageHeader> messages =
-				groupInvitationManager1.getMessages(contactId0From1);
+				withinTransactionReturns(db1, txn -> groupInvitationManager1
+						.getMessageHeaders(txn, contactId0From1));
 		assertEquals(1, messages.size());
 		MessageId inviteId = messages.iterator().next().getId();
 
@@ -454,17 +459,18 @@ public class GroupInvitationIntegrationTest
 				.respondToInvitation(contactId0From1, privateGroup0, false);
 
 		// we should have an invitation and a decline message
-		messages = groupInvitationManager1.getMessages(contactId0From1);
+		messages = withinTransactionReturns(db1, txn -> groupInvitationManager1
+				.getMessageHeaders(txn, contactId0From1));
 		assertEquals(2, messages.size());
 
 		// delete only invitation
 		withinTransaction(db1, txn -> {
 			db1.deleteMessage(txn, inviteId);
 			db1.deleteMessageMetadata(txn, inviteId);
+			// This should fail
+			groupInvitationManager1.getMessageHeaders(txn, contactId0From1);
 		});
 
-		// This should fail
-		groupInvitationManager1.getMessages(contactId0From1);
 	}
 
 	private void sendInvitation(long timestamp, @Nullable String msg) throws

briar-core/src/test/java/org/briarproject/briar/privategroup/invitation/GroupInvitationManagerImplTest.java

@@ -669,8 +669,6 @@ public class GroupInvitationManagerImplTest extends BrambleMockTestCase {
 						invite.getCreator(), invite.getSalt());
 
 		context.checking(new Expectations() {{
-			oneOf(db).startTransaction(true);
-			will(returnValue(txn));
 			oneOf(db).getContact(txn, contactId);
 			will(returnValue(contact));
 			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
@@ -700,13 +698,10 @@ public class GroupInvitationManagerImplTest extends BrambleMockTestCase {
 			oneOf(messageParser).parseMetadata(meta);
 			will(returnValue(messageMetadata1));
 			oneOf(db).getMessageStatus(txn, contactId, messageId2);
-			// end transaction
-			oneOf(db).commitTransaction(txn);
-			oneOf(db).endTransaction(txn);
 		}});
 
 		Collection<PrivateMessageHeader> messages =
-				groupInvitationManager.getMessages(contactId);
+				groupInvitationManager.getMessageHeaders(txn, contactId);
 		assertEquals(2, messages.size());
 		for (PrivateMessageHeader m : messages) {
 			assertEquals(contactGroup.getId(), m.getGroupId());

briar-core/src/test/java/org/briarproject/briar/sharing/BlogSharingIntegrationTest.java

@@ -27,9 +27,7 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
-import java.util.ArrayList;
 import java.util.Collection;
-import java.util.List;
 
 import static org.briarproject.briar.api.blog.BlogSharingManager.CLIENT_ID;
 import static org.briarproject.briar.api.blog.BlogSharingManager.MAJOR_VERSION;
@@ -147,8 +145,8 @@ public class BlogSharingIntegrationTest
 		assertTrue(blogManager1.getBlogs().contains(blog2));
 
 		// invitee has one invitation message from sharer
-		List<PrivateMessageHeader> list = new ArrayList<>(
+		Collection<PrivateMessageHeader> list = withinTransactionReturns(db1,
-				blogSharingManager1.getMessages(contactId0From1));
+				txn -> blogSharingManager1.getMessageHeaders(txn, contactId0From1));
 		assertEquals(2, list.size());
 		// check other things are alright with the message
 		for (PrivateMessageHeader m : list) {
@@ -168,9 +166,9 @@ public class BlogSharingIntegrationTest
 			}
 		}
 		// sharer has own invitation message and response
-		assertEquals(2,
+		assertEquals(2, withinTransactionReturns(db0,
-				blogSharingManager0.getMessages(contactId1From0)
+				txn -> blogSharingManager0.getMessageHeaders(txn, contactId1From0))
-						.size());
+				.size());
 		// blog can not be shared again
 		assertFalse(blogSharingManager0.canBeShared(blog2.getId(),
 				contact1From0));
@@ -220,8 +218,8 @@ public class BlogSharingIntegrationTest
 		assertTrue(blogManager1.getBlogs().contains(rssBlog));
 
 		// invitee has one invitation message from sharer
-		List<PrivateMessageHeader> list = new ArrayList<>(
+		Collection<PrivateMessageHeader> list = withinTransactionReturns(db1,
-				blogSharingManager1.getMessages(contactId0From1));
+				txn -> blogSharingManager1.getMessageHeaders(txn, contactId0From1));
 		assertEquals(2, list.size());
 		// check other things are alright with the message
 		for (PrivateMessageHeader m : list) {
@@ -241,8 +239,9 @@ public class BlogSharingIntegrationTest
 			}
 		}
 		// sharer has own invitation message and response
-		assertEquals(2, blogSharingManager0.getMessages(
+		assertEquals(2, withinTransactionReturns(db0,
-				contactId1From0).size());
+				txn -> blogSharingManager0.getMessageHeaders(txn, contactId1From0))
+				.size());
 		// blog can not be shared again
 		assertFalse(blogSharingManager0.canBeShared(rssBlog.getId(),
 				contact1From0));
@@ -281,8 +280,8 @@ public class BlogSharingIntegrationTest
 		assertEquals(0, blogSharingManager1.getInvitations().size());
 
 		// invitee has one invitation message from sharer and one response
-		List<PrivateMessageHeader> list = new ArrayList<>(
+		Collection<PrivateMessageHeader> list = withinTransactionReturns(db1,
-				blogSharingManager1.getMessages(contactId0From1));
+				txn -> blogSharingManager1.getMessageHeaders(txn, contactId0From1));
 		assertEquals(2, list.size());
 		// check things are alright with the  message
 		for (PrivateMessageHeader m : list) {
@@ -301,9 +300,9 @@ public class BlogSharingIntegrationTest
 			}
 		}
 		// sharer has own invitation message and response
-		assertEquals(2,
+		assertEquals(2, withinTransactionReturns(db0,
-				blogSharingManager0.getMessages(contactId1From0)
+				txn -> blogSharingManager0.getMessageHeaders(txn, contactId1From0))
-						.size());
+				.size());
 		// blog can be shared again
 		assertTrue(
 				blogSharingManager0.canBeShared(blog2.getId(), contact1From0));
@@ -389,7 +388,8 @@ public class BlogSharingIntegrationTest
 
 		// make sure 1 knows that they have blog2 already
 		Collection<PrivateMessageHeader> messages =
-				blogSharingManager1.getMessages(contactId0From1);
+				withinTransactionReturns(db1, txn -> blogSharingManager1
+						.getMessageHeaders(txn, contactId0From1));
 		assertEquals(2, messages.size());
 		assertEquals(blog2, blogManager1.getBlog(blog2.getId()));
 
@@ -559,7 +559,7 @@ public class BlogSharingIntegrationTest
 				BlogInvitationRequestReceivedEvent event =
 						(BlogInvitationRequestReceivedEvent) e;
 				eventWaiter.assertEquals(contactId1From0, event.getContactId());
-				Blog b = event.getRequest().getObject();
+				Blog b = event.getMessageHeader().getObject();
 				try {
 					Contact c = contactManager0.getContact(contactId1From0);
 					blogSharingManager0.respondToInvitation(b, c, true);
@@ -595,7 +595,7 @@ public class BlogSharingIntegrationTest
 						(BlogInvitationRequestReceivedEvent) e;
 				requestReceived = true;
 				if (!answer) return;
-				Blog b = event.getRequest().getObject();
+				Blog b = event.getMessageHeader().getObject();
 				try {
 					eventWaiter.assertEquals(1,
 							blogSharingManager1.getInvitations().size());

briar-core/src/test/java/org/briarproject/briar/sharing/ForumSharingIntegrationTest.java

@@ -5,7 +5,6 @@ import net.jodah.concurrentunit.Waiter;
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.data.BdfDictionary;
 import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
@@ -32,9 +31,7 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
-import java.util.ArrayList;
 import java.util.Collection;
-import java.util.List;
 
 import static junit.framework.Assert.assertNotNull;
 import static org.briarproject.bramble.util.StringUtils.getRandomString;
@@ -131,8 +128,8 @@ public class ForumSharingIntegrationTest
 		assertEquals(1, forumManager1.getForums().size());
 
 		// invitee has one invitation message from sharer
-		List<PrivateMessageHeader> list = new ArrayList<>(
+		Collection<PrivateMessageHeader> list = withinTransactionReturns(db1,
-				forumSharingManager1.getMessages(contactId0From1));
+				txn -> forumSharingManager1.getMessageHeaders(txn, contactId0From1));
 		assertEquals(2, list.size());
 		// check other things are alright with the forum message
 		for (PrivateMessageHeader m : list) {
@@ -151,9 +148,8 @@ public class ForumSharingIntegrationTest
 			}
 		}
 		// sharer has own invitation message and response
-		assertEquals(2,
+		assertEquals(2, withinTransactionReturns(db0, txn ->
-				forumSharingManager0.getMessages(contactId1From0)
+				forumSharingManager0.getMessageHeaders(txn, contactId1From0)).size());
-						.size());
 		// forum can not be shared again
 		Contact c1 = contactManager0.getContact(contactId1From0);
 		assertFalse(forumSharingManager0.canBeShared(forum0.getId(), c1));
@@ -188,8 +184,8 @@ public class ForumSharingIntegrationTest
 		assertEquals(0, forumSharingManager1.getInvitations().size());
 
 		// invitee has one invitation message from sharer and one response
-		List<PrivateMessageHeader> list = new ArrayList<>(
+		Collection<PrivateMessageHeader> list = withinTransactionReturns(db1,
-				forumSharingManager1.getMessages(contactId0From1));
+				txn -> forumSharingManager1.getMessageHeaders(txn, contactId0From1));
 		assertEquals(2, list.size());
 		// check things are alright with the forum message
 		for (PrivateMessageHeader m : list) {
@@ -208,9 +204,8 @@ public class ForumSharingIntegrationTest
 			}
 		}
 		// sharer has own invitation message and response
-		assertEquals(2,
+		assertEquals(2, withinTransactionReturns(db0, txn ->
-				forumSharingManager0.getMessages(contactId1From0)
+				forumSharingManager0.getMessageHeaders(txn, contactId1From0)).size());
-						.size());
 		// forum can be shared again
 		Contact c1 = contactManager0.getContact(contactId1From0);
 		assertTrue(forumSharingManager0.canBeShared(forum0.getId(), c1));
@@ -451,10 +446,7 @@ public class ForumSharingIntegrationTest
 		listenToEvents(true);
 
 		// invitee adds the same forum
-		Transaction txn = db1.startTransaction(false);
+		withinTransaction(db1, txn -> forumManager1.addForum(txn, forum0));
-		forumManager1.addForum(txn, forum0);
-		db1.commitTransaction(txn);
-		db1.endTransaction(txn);
 
 		// send invitation
 		forumSharingManager0
@@ -486,10 +478,12 @@ public class ForumSharingIntegrationTest
 				.contains(contact0From1));
 
 		// and both have each other's invitations (and no response)
-		assertEquals(2, forumSharingManager0
+		assertEquals(2, withinTransactionReturns(db0, txn2 ->
-				.getMessages(contactId1From0).size());
+				forumSharingManager0.getMessageHeaders(txn2, contactId1From0))
-		assertEquals(2, forumSharingManager1
+				.size());
-				.getMessages(contactId0From1).size());
+		assertEquals(2, withinTransactionReturns(db1, txn2 ->
+				forumSharingManager1.getMessageHeaders(txn2, contactId0From1))
+				.size());
 
 		// there are no more open invitations
 		assertTrue(forumSharingManager0.getInvitations().isEmpty());
@@ -564,10 +558,7 @@ public class ForumSharingIntegrationTest
 	@Test
 	public void testTwoContactsShareSameForum() throws Exception {
 		// second sharer adds the same forum
-		Transaction txn = db2.startTransaction(false);
+		withinTransaction(db2, txn -> db2.addGroup(txn, forum0.getGroup()));
-		db2.addGroup(txn, forum0.getGroup());
-		db2.commitTransaction(txn);
-		db2.endTransaction(txn);
 
 		// add listeners
 		listener0 = new SharerListener();
@@ -744,8 +735,9 @@ public class ForumSharingIntegrationTest
 
 		// get invitation MessageId for later
 		MessageId invitationId = null;
-		for (PrivateMessageHeader m : forumSharingManager1
+		Collection<PrivateMessageHeader> list = withinTransactionReturns(db1,
-				.getMessages(contactId0From1)) {
+				txn -> forumSharingManager1.getMessageHeaders(txn, contactId0From1));
+		for (PrivateMessageHeader m : list) {
 			if (m instanceof ForumInvitationRequest) {
 				invitationId = m.getId();
 			}
@@ -813,7 +805,7 @@ public class ForumSharingIntegrationTest
 						(ForumInvitationRequestReceivedEvent) e;
 				eventWaiter.assertEquals(contactId1From0, event.getContactId());
 				requestReceived = true;
-				Forum f = event.getRequest().getObject();
+				Forum f = event.getMessageHeader().getObject();
 				try {
 					if (respond) {
 						Contact c = contactManager0.getContact(contactId1From0);
@@ -851,7 +843,7 @@ public class ForumSharingIntegrationTest
 						(ForumInvitationRequestReceivedEvent) e;
 				requestReceived = true;
 				if (!answer) return;
-				Forum f = event.getRequest().getObject();
+				Forum f = event.getMessageHeader().getObject();
 				try {
 					if (respond) {
 						eventWaiter.assertEquals(1,

briar-core/src/test/java/org/briarproject/briar/test/BriarIntegrationTest.java

@@ -2,6 +2,7 @@ package org.briarproject.briar.test;
 
 import net.jodah.concurrentunit.Waiter;
 
+import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.client.ClientHelper;
 import org.briarproject.bramble.api.client.ContactGroupFactory;
 import org.briarproject.bramble.api.contact.Contact;
@@ -380,18 +381,38 @@ public abstract class BriarIntegrationTest<C extends BriarIntegrationTestCompone
 
 	@FunctionalInterface
 	protected interface TransactionScope {
-		void execute(Transaction txn) throws DbException;
+		void execute(Transaction txn) throws DbException, FormatException;
 	}
 
-	protected void withinTransaction(DatabaseComponent db, TransactionScope scope)
+	protected void withinTransaction(DatabaseComponent db,
-			throws DbException {
+			TransactionScope scope) throws DbException {
 		Transaction txn = db.startTransaction(false);
 		try {
 			scope.execute(txn);
 			db.commitTransaction(txn);
+		} catch (FormatException e) {
+			throw new DbException(e);
 		} finally {
 			db.endTransaction(txn);
 		}
 	}
 
+	@FunctionalInterface
+	protected interface TransactionResultScope<R> {
+		R execute(Transaction txn) throws DbException;
+	}
+
+	protected <R> R withinTransactionReturns(DatabaseComponent db,
+			TransactionResultScope<R> scope) throws DbException {
+		Transaction txn = db.startTransaction(false);
+		R r;
+		try {
+			r = scope.execute(txn);
+			db.commitTransaction(txn);
+		} finally {
+			db.endTransaction(txn);
+		}
+		return r;
+	}
+
 }