Add transactional helper methods to DbViewModel.

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

@@ -0,0 +1,6 @@
+package org.briarproject.bramble.api;
+
+public interface ThrowingRunnable<T extends Throwable> {
+
+	void run() throws T;
+}

bramble-core/src/main/java/org/briarproject/bramble/sync/DuplexOutgoingSession.java

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.sync;
 
+import org.briarproject.bramble.api.ThrowingRunnable;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
 import org.briarproject.bramble.api.db.DatabaseComponent;

bramble-core/src/main/java/org/briarproject/bramble/sync/SimplexOutgoingSession.java

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.sync;
 
+import org.briarproject.bramble.api.ThrowingRunnable;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
 import org.briarproject.bramble.api.db.DatabaseComponent;

bramble-core/src/main/java/org/briarproject/bramble/sync/ThrowingRunnable.java

@@ -1,6 +0,0 @@
-package org.briarproject.bramble.sync;
-
-interface ThrowingRunnable<T extends Throwable> {
-
-	void run() throws T;
-}

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

@@ -45,10 +45,8 @@ import androidx.arch.core.util.Function;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
 
-import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
-import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.now;
 
 @NotNullByDefault
@@ -173,14 +171,9 @@ class ContactListViewModel extends DbViewModel implements EventListener {
 	}
 
 	void checkForPendingContacts() {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() -> {
-			try {
+			boolean hasPending = !contactManager.getPendingContacts().isEmpty();
-				boolean hasPending =
+			hasPendingContacts.postValue(hasPending);
-						!contactManager.getPendingContacts().isEmpty();
-				hasPendingContacts.postValue(hasPending);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
 		});
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/contact/add/remote/AddContactViewModel.java

@@ -2,12 +2,9 @@ package org.briarproject.briar.android.contact.add.remote;
 
 import android.app.Application;
 
-import org.briarproject.bramble.api.FormatException;
-import org.briarproject.bramble.api.UnsupportedVersionException;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.contact.PendingContact;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
-import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.NoSuchPendingContactException;
 import org.briarproject.bramble.api.db.TransactionManager;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
@@ -18,7 +15,6 @@ import org.briarproject.briar.android.viewmodel.LiveEvent;
 import org.briarproject.briar.android.viewmodel.LiveResult;
 import org.briarproject.briar.android.viewmodel.MutableLiveEvent;
 
-import java.security.GeneralSecurityException;
 import java.util.concurrent.Executor;
 import java.util.logging.Logger;
 
@@ -66,15 +62,10 @@ public class AddContactViewModel extends DbViewModel {
 	}
 
 	private void loadHandshakeLink() {
-		runOnDbThread(() -> {
+		// If an exception is thrown the UI should stay disabled,
-			try {
+		// leaving the user unable to proceed
-				handshakeLink.postValue(contactManager.getHandshakeLink());
+		runOnDbThreadOrLogException(() ->
-			} catch (DbException e) {
+				handshakeLink.postValue(contactManager.getHandshakeLink()));
-				logException(LOG, WARNING, e);
-				// the UI should stay disabled in this case,
-				// leaving the user unable to proceed
-			}
-		});
 	}
 
 	LiveData<String> getHandshakeLink() {
@@ -106,17 +97,11 @@ public class AddContactViewModel extends DbViewModel {
 	void addContact(String nickname) {
 		if (remoteHandshakeLink == null) throw new IllegalStateException();
 		runOnDbThread(() -> {
-			try {
+			contactManager.addPendingContact(remoteHandshakeLink, nickname);
-				contactManager.addPendingContact(remoteHandshakeLink, nickname);
+			addContactResult.postValue(new LiveResult<>(true));
-				addContactResult.postValue(new LiveResult<>(true));
+		}, e -> {
-			} catch (UnsupportedVersionException e) {
+			logException(LOG, WARNING, e);
-				logException(LOG, WARNING, e);
+			addContactResult.postValue(new LiveResult<>(e));
-				addContactResult.postValue(new LiveResult<>(e));
-			} catch (DbException | FormatException
-					| GeneralSecurityException e) {
-				logException(LOG, WARNING, e);
-				addContactResult.postValue(new LiveResult<>(e));
-			}
 		});
 	}
 
@@ -126,13 +111,13 @@ public class AddContactViewModel extends DbViewModel {
 
 	public void updatePendingContact(String name, PendingContact p) {
 		runOnDbThread(() -> {
-			try {
+			contactManager.removePendingContact(p.getId());
-				contactManager.removePendingContact(p.getId());
+			addContact(name);
-				addContact(name);
+		}, e -> {
-			} catch (NoSuchPendingContactException e) {
+			if (e instanceof NoSuchPendingContactException) {
 				logException(LOG, WARNING, e);
 				// no error in UI as pending contact was converted into contact
-			} catch (DbException e) {
+			} else {
 				logException(LOG, WARNING, e);
 				addContactResult.postValue(new LiveResult<>(e));
 			}

briar-android/src/main/java/org/briarproject/briar/android/contact/add/remote/PendingContactListViewModel.java

@@ -10,7 +10,6 @@ import org.briarproject.bramble.api.contact.PendingContactState;
 import org.briarproject.bramble.api.contact.event.PendingContactRemovedEvent;
 import org.briarproject.bramble.api.contact.event.PendingContactStateChangedEvent;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
-import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.TransactionManager;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventBus;
@@ -33,10 +32,8 @@ import javax.inject.Inject;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
 
-import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.contact.PendingContactState.OFFLINE;
-import static org.briarproject.bramble.util.LogUtils.logException;
 
 @NotNullByDefault
 public class PendingContactListViewModel extends DbViewModel
@@ -90,24 +87,20 @@ public class PendingContactListViewModel extends DbViewModel
 	}
 
 	private void loadPendingContacts() {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() -> {
-			try {
+			Collection<Pair<PendingContact, PendingContactState>> pairs =
-				Collection<Pair<PendingContact, PendingContactState>> pairs =
+					contactManager.getPendingContacts();
-						contactManager.getPendingContacts();
+			List<PendingContactItem> items = new ArrayList<>(pairs.size());
-				List<PendingContactItem> items = new ArrayList<>(pairs.size());
+			boolean online = pairs.isEmpty();
-				boolean online = pairs.isEmpty();
+			for (Pair<PendingContact, PendingContactState> pair : pairs) {
-				for (Pair<PendingContact, PendingContactState> pair : pairs) {
+				PendingContact p = pair.getFirst();
-					PendingContact p = pair.getFirst();
+				PendingContactState state = pair.getSecond();
-					PendingContactState state = pair.getSecond();
+				long lastPoll = rendezvousPoller.getLastPollTime(p.getId());
-					long lastPoll = rendezvousPoller.getLastPollTime(p.getId());
+				items.add(new PendingContactItem(p, state, lastPoll));
-					items.add(new PendingContactItem(p, state, lastPoll));
+				online = online || state != OFFLINE;
-					online = online || state != OFFLINE;
-				}
-				pendingContacts.postValue(items);
-				hasInternetConnection.postValue(online);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
 			}
+			pendingContacts.postValue(items);
+			hasInternetConnection.postValue(online);
 		});
 	}
 
@@ -116,13 +109,8 @@ public class PendingContactListViewModel extends DbViewModel
 	}
 
 	void removePendingContact(PendingContactId id) {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() ->
-			try {
+				contactManager.removePendingContact(id));
-				contactManager.removePendingContact(id);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
-		});
 	}
 
 	LiveData<Boolean> getHasInternetConnection() {

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationViewModel.java

@@ -149,7 +149,7 @@ public class ConversationViewModel extends DbViewModel
 			AttachmentReceivedEvent a = (AttachmentReceivedEvent) e;
 			if (a.getContactId().equals(contactId)) {
 				LOG.info("Attachment received");
-				runOnDbThread(() -> attachmentRetriever
+				runOnDbThreadOrLogException(() -> attachmentRetriever
 						.loadAttachmentItem(a.getMessageId()));
 			}
 		} else if (e instanceof AvatarUpdatedEvent) {
@@ -194,44 +194,36 @@ public class ConversationViewModel extends DbViewModel
 
 	private void loadContact(ContactId contactId) {
 		runOnDbThread(() -> {
-			try {
+			long start = now();
-				long start = now();
+			Contact c = contactManager.getContact(contactId);
-				Contact c = contactManager.getContact(contactId);
+			AuthorInfo authorInfo = authorManager.getAuthorInfo(c);
-				AuthorInfo authorInfo = authorManager.getAuthorInfo(c);
+			contactItem.postValue(new ContactItem(c, authorInfo));
-				contactItem.postValue(new ContactItem(c, authorInfo));
+			logDuration(LOG, "Loading contact", start);
-				logDuration(LOG, "Loading contact", start);
+			start = now();
-				start = now();
+			checkFeaturesAndOnboarding(contactId);
-				checkFeaturesAndOnboarding(contactId);
+			logDuration(LOG, "Checking for image support", start);
-				logDuration(LOG, "Checking for image support", start);
+		}, e -> {
-			} catch (NoSuchContactException e) {
+			if (e instanceof NoSuchContactException) {
 				contactDeleted.postValue(true);
-			} catch (DbException e) {
+			} else {
 				logException(LOG, WARNING, e);
 			}
 		});
 	}
 
 	void markMessageRead(GroupId g, MessageId m) {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() -> {
-			try {
+			long start = now();
-				long start = now();
+			messagingManager.setReadFlag(g, m, true);
-				messagingManager.setReadFlag(g, m, true);
+			logDuration(LOG, "Marking read", start);
-				logDuration(LOG, "Marking read", start);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
 		});
 	}
 
 	void setContactAlias(String alias) {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() -> {
-			try {
+			contactManager.setContactAlias(requireNonNull(contactId),
-				contactManager.setContactAlias(requireNonNull(contactId),
+					alias.isEmpty() ? null : alias);
-						alias.isEmpty() ? null : alias);
+			loadContact(contactId);
-				loadContact(contactId);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
 		});
 	}
 
@@ -327,21 +319,17 @@ public class ConversationViewModel extends DbViewModel
 	@UiThread
 	private void storeMessage(PrivateMessage m) {
 		attachmentCreator.onAttachmentsSent(m.getMessage().getId());
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() -> {
-			try {
+			long start = now();
-				long start = now();
+			messagingManager.addLocalMessage(m);
-				messagingManager.addLocalMessage(m);
+			logDuration(LOG, "Storing message", start);
-				logDuration(LOG, "Storing message", start);
+			Message message = m.getMessage();
-				Message message = m.getMessage();
+			PrivateMessageHeader h = new PrivateMessageHeader(
-				PrivateMessageHeader h = new PrivateMessageHeader(
+					message.getId(), message.getGroupId(),
-						message.getId(), message.getGroupId(),
+					message.getTimestamp(), true, true, false, false,
-						message.getTimestamp(), true, true, false, false,
+					m.hasText(), m.getAttachmentHeaders());
-						m.hasText(), m.getAttachmentHeaders());
+			// TODO add text to cache when available here
-				// TODO add text to cache when available here
+			addedHeader.postEvent(h);
-				addedHeader.postEvent(h);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
 		});
 	}
 
@@ -383,12 +371,7 @@ public class ConversationViewModel extends DbViewModel
 
 	@UiThread
 	void recheckFeaturesAndOnboarding(ContactId contactId) {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() ->
-			try {
+				checkFeaturesAndOnboarding(contactId));
-				checkFeaturesAndOnboarding(contactId);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
-		});
 	}
 }

briar-android/src/main/java/org/briarproject/briar/android/conversation/ImageViewModel.java

@@ -6,7 +6,6 @@ import android.net.Uri;
 import android.view.View;
 
 import org.briarproject.bramble.api.db.DatabaseExecutor;
-import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.TransactionManager;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventBus;
@@ -198,14 +197,12 @@ public class ImageViewModel extends DbViewModel implements EventListener {
 	private void saveImage(AttachmentItem attachment, OutputStreamProvider osp,
 			@Nullable Runnable afterCopy) {
 		runOnDbThread(() -> {
-			try {
+			Attachment a =
-				Attachment a =
+					attachmentReader.getAttachment(attachment.getHeader());
-						attachmentReader.getAttachment(attachment.getHeader());
+			copyImageFromDb(a, osp, afterCopy);
-				copyImageFromDb(a, osp, afterCopy);
+		}, e -> {
-			} catch (DbException e) {
+			logException(LOG, WARNING, e);
-				logException(LOG, WARNING, e);
+			saveState.postEvent(true);
-				saveState.postEvent(true);
-			}
 		});
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/forum/ForumListViewModel.java

@@ -40,10 +40,8 @@ import androidx.annotation.UiThread;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
 
-import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
-import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.now;
 import static org.briarproject.briar.api.forum.ForumManager.CLIENT_ID;
 
@@ -164,15 +162,11 @@ class ForumListViewModel extends DbViewModel implements EventListener {
 	}
 
 	void loadForumInvitations() {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() -> {
-			try {
+			long start = now();
-				long start = now();
+			int available = forumSharingManager.getInvitations().size();
-				int available = forumSharingManager.getInvitations().size();
+			logDuration(LOG, "Loading available", start);
-				logDuration(LOG, "Loading available", start);
+			numInvitations.postValue(available);
-				numInvitations.postValue(available);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
 		});
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/forum/ForumViewModel.java

@@ -51,10 +51,8 @@ import androidx.lifecycle.MutableLiveData;
 
 import static android.widget.Toast.LENGTH_SHORT;
 import static java.lang.Math.max;
-import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
-import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.now;
 
 @MethodsNotNullByDefault
@@ -122,14 +120,8 @@ class ForumViewModel extends ThreadListViewModel<ForumPostItem> {
 
 	LiveData<Forum> loadForum() {
 		MutableLiveData<Forum> forum = new MutableLiveData<>();
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() ->
-			try {
+				forum.postValue(forumManager.getForum(groupId)));
-				Forum f = forumManager.getForum(groupId);
-				forum.postValue(f);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
-		});
 		return forum;
 	}
 
@@ -147,16 +139,12 @@ class ForumViewModel extends ThreadListViewModel<ForumPostItem> {
 	@Override
 	public void createAndStoreMessage(String text,
 			@Nullable MessageId parentId) {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() -> {
-			try {
+			LocalAuthor author = identityManager.getLocalAuthor();
-				LocalAuthor author = identityManager.getLocalAuthor();
+			GroupCount count = forumManager.getGroupCount(groupId);
-				GroupCount count = forumManager.getGroupCount(groupId);
+			long timestamp = max(count.getLatestMsgTime() + 1,
-				long timestamp = max(count.getLatestMsgTime() + 1,
+					clock.currentTimeMillis());
-						clock.currentTimeMillis());
+			createMessage(text, timestamp, parentId, author);
-				createMessage(text, timestamp, parentId, author);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
 		});
 	}
 
@@ -171,15 +159,11 @@ class ForumViewModel extends ThreadListViewModel<ForumPostItem> {
 	}
 
 	private void storePost(ForumPost msg, String text) {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() -> {
-			try {
+			long start = now();
-				long start = now();
+			ForumPostHeader header = forumManager.addLocalPost(msg);
-				ForumPostHeader header = forumManager.addLocalPost(msg);
+			addItemAsync(buildItem(header, text));
-				addItemAsync(buildItem(header, text));
+			logDuration(LOG, "Storing forum post", start);
-				logDuration(LOG, "Storing forum post", start);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
 		});
 	}
 
@@ -195,39 +179,23 @@ class ForumViewModel extends ThreadListViewModel<ForumPostItem> {
 
 	@Override
 	protected void markItemRead(ForumPostItem item) {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() ->
-			try {
+				forumManager.setReadFlag(groupId, item.getId(), true));
-				forumManager.setReadFlag(groupId, item.getId(), true);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
-		});
 	}
 
 	public void loadSharingContacts() {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(true, txn -> {
-			try {
+			Collection<Contact> contacts =
-				Collection<Contact> contacts =
+					forumSharingManager.getSharedWith(txn, groupId);
-						forumSharingManager.getSharedWith(groupId);
+			Collection<ContactId> contactIds = new ArrayList<>(contacts.size());
-				Collection<ContactId> contactIds =
+			for (Contact c : contacts) contactIds.add(c.getId());
-						new ArrayList<>(contacts.size());
+			txn.attach(() -> sharingController.addAll(contactIds));
-				for (Contact c : contacts) contactIds.add(c.getId());
-				sharingController.addAll(contactIds);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
 		});
 	}
 
 	void deleteForum() {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() ->
-			try {
+				forumManager.removeForum(forumManager.getForum(groupId)));
-				Forum f = forumManager.getForum(groupId);
-				forumManager.removeForum(f);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
-		});
 		Toast.makeText(getApplication(), R.string.forum_left_toast,
 				LENGTH_SHORT).show();
 	}

briar-android/src/main/java/org/briarproject/briar/android/navdrawer/NavDrawerViewModel.java

@@ -3,7 +3,6 @@ package org.briarproject.briar.android.navdrawer;
 import android.app.Application;
 
 import org.briarproject.bramble.api.db.DatabaseExecutor;
-import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.TransactionManager;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
@@ -66,34 +65,27 @@ public class NavDrawerViewModel extends DbViewModel {
 
 	@UiThread
 	void checkExpiryWarning() {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() -> {
-			try {
+			Settings settings = settingsManager.getSettings(SETTINGS_NAMESPACE);
-				Settings settings =
+			int warningInt = settings.getInt(EXPIRY_DATE_WARNING, 0);
-						settingsManager.getSettings(SETTINGS_NAMESPACE);
-				int warningInt = settings.getInt(EXPIRY_DATE_WARNING, 0);
 
-				if (warningInt == 0) {
+			if (warningInt == 0) {
-					// we have not warned before
+				// we have not warned before
+				showExpiryWarning.postValue(true);
+			} else {
+				long warningLong = warningInt * 1000L;
+				long now = System.currentTimeMillis();
+				long daysSinceLastWarning =
+						(now - warningLong) / DAYS.toMillis(1);
+				long daysBeforeExpiry = (EXPIRY_DATE - now) / DAYS.toMillis(1);
+
+				if (daysSinceLastWarning >= 30) {
+					showExpiryWarning.postValue(true);
+				} else if (daysBeforeExpiry <= 3 && daysSinceLastWarning > 0) {
 					showExpiryWarning.postValue(true);
 				} else {
-					long warningLong = warningInt * 1000L;
+					showExpiryWarning.postValue(false);
-					long now = System.currentTimeMillis();
-					long daysSinceLastWarning =
-							(now - warningLong) / DAYS.toMillis(1);
-					long daysBeforeExpiry =
-							(EXPIRY_DATE - now) / DAYS.toMillis(1);
-
-					if (daysSinceLastWarning >= 30) {
-						showExpiryWarning.postValue(true);
-					} else if (daysBeforeExpiry <= 3 &&
-							daysSinceLastWarning > 0) {
-						showExpiryWarning.postValue(true);
-					} else {
-						showExpiryWarning.postValue(false);
-					}
 				}
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
 			}
 		});
 	}
@@ -101,15 +93,11 @@ public class NavDrawerViewModel extends DbViewModel {
 	@UiThread
 	void expiryWarningDismissed() {
 		showExpiryWarning.setValue(false);
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() -> {
-			try {
+			Settings settings = new Settings();
-				Settings settings = new Settings();
+			int date = (int) (System.currentTimeMillis() / 1000L);
-				int date = (int) (System.currentTimeMillis() / 1000L);
+			settings.putInt(EXPIRY_DATE_WARNING, date);
-				settings.putInt(EXPIRY_DATE_WARNING, date);
+			settingsManager.mergeSettings(settings, SETTINGS_NAMESPACE);
-				settingsManager.mergeSettings(settings, SETTINGS_NAMESPACE);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
 		});
 	}
 
@@ -125,15 +113,12 @@ public class NavDrawerViewModel extends DbViewModel {
 			return;
 		}
 		runOnDbThread(() -> {
-			try {
+			Settings settings = settingsManager.getSettings(SETTINGS_NAMESPACE);
-				Settings settings =
+			boolean ask = settings.getBoolean(DOZE_ASK_AGAIN, true);
-						settingsManager.getSettings(SETTINGS_NAMESPACE);
+			shouldAskForDozeWhitelisting.postValue(ask);
-				boolean ask = settings.getBoolean(DOZE_ASK_AGAIN, true);
+		}, e -> {
-				shouldAskForDozeWhitelisting.postValue(ask);
+			logException(LOG, WARNING, e);
-			} catch (DbException e) {
+			shouldAskForDozeWhitelisting.postValue(true);
-				logException(LOG, WARNING, e);
-				shouldAskForDozeWhitelisting.postValue(true);
-			}
 		});
 	}
 
@@ -145,30 +130,21 @@ public class NavDrawerViewModel extends DbViewModel {
 	@UiThread
 	void checkTransportsOnboarding() {
 		if (showTransportsOnboarding.getValue() != null) return;
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() -> {
-			try {
+			Settings settings = settingsManager.getSettings(SETTINGS_NAMESPACE);
-				Settings settings =
+			boolean show =
-						settingsManager.getSettings(SETTINGS_NAMESPACE);
+					settings.getBoolean(SHOW_TRANSPORTS_ONBOARDING, true);
-				boolean show =
+			showTransportsOnboarding.postValue(show);
-						settings.getBoolean(SHOW_TRANSPORTS_ONBOARDING, true);
-				showTransportsOnboarding.postValue(show);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
 		});
 	}
 
 	@UiThread
 	void transportsOnboardingShown() {
 		showTransportsOnboarding.setValue(false);
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() -> {
-			try {
+			Settings settings = new Settings();
-				Settings settings = new Settings();
+			settings.putBoolean(SHOW_TRANSPORTS_ONBOARDING, false);
-				settings.putBoolean(SHOW_TRANSPORTS_ONBOARDING, false);
+			settingsManager.mergeSettings(settings, SETTINGS_NAMESPACE);
-				settingsManager.mergeSettings(settings, SETTINGS_NAMESPACE);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
 		});
 	}
 }

briar-android/src/main/java/org/briarproject/briar/android/navdrawer/PluginViewModel.java

@@ -45,12 +45,10 @@ import static android.bluetooth.BluetoothAdapter.ACTION_STATE_CHANGED;
 import static android.bluetooth.BluetoothAdapter.EXTRA_STATE;
 import static android.bluetooth.BluetoothAdapter.STATE_ON;
 import static java.util.logging.Level.INFO;
-import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.plugin.Plugin.PREF_PLUGIN_ENABLE;
 import static org.briarproject.bramble.api.plugin.Plugin.State.STARTING_STOPPING;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
-import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.now;
 
 @NotNullByDefault
@@ -185,20 +183,16 @@ public class PluginViewModel extends DbViewModel implements EventListener {
 	}
 
 	private void loadSettings() {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() -> {
-			try {
+			boolean tor = isPluginEnabled(TorConstants.ID,
-				boolean tor = isPluginEnabled(TorConstants.ID,
+					TorConstants.DEFAULT_PREF_PLUGIN_ENABLE);
-						TorConstants.DEFAULT_PREF_PLUGIN_ENABLE);
+			torEnabledSetting.postValue(tor);
-				torEnabledSetting.postValue(tor);
+			boolean wifi = isPluginEnabled(LanTcpConstants.ID,
-				boolean wifi = isPluginEnabled(LanTcpConstants.ID,
+					LanTcpConstants.DEFAULT_PREF_PLUGIN_ENABLE);
-						LanTcpConstants.DEFAULT_PREF_PLUGIN_ENABLE);
+			wifiEnabledSetting.postValue(wifi);
-				wifiEnabledSetting.postValue(wifi);
+			boolean bt = isPluginEnabled(BluetoothConstants.ID,
-				boolean bt = isPluginEnabled(BluetoothConstants.ID,
+					BluetoothConstants.DEFAULT_PREF_PLUGIN_ENABLE);
-						BluetoothConstants.DEFAULT_PREF_PLUGIN_ENABLE);
+			btEnabledSetting.postValue(bt);
-				btEnabledSetting.postValue(bt);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
 		});
 	}
 
@@ -222,14 +216,10 @@ public class PluginViewModel extends DbViewModel implements EventListener {
 	}
 
 	private void mergeSettings(Settings s, String namespace) {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() -> {
-			try {
+			long start = now();
-				long start = now();
+			settingsManager.mergeSettings(s, namespace);
-				settingsManager.mergeSettings(s, namespace);
+			logDuration(LOG, "Merging settings", start);
-				logDuration(LOG, "Merging settings", start);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
 		});
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/privategroup/conversation/GroupViewModel.java

@@ -52,10 +52,8 @@ import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
 
 import static java.lang.Math.max;
-import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
-import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.now;
 
 @MethodsNotNullByDefault
@@ -143,15 +141,11 @@ class GroupViewModel extends ThreadListViewModel<GroupMessageItem> {
 	}
 
 	private void loadPrivateGroup(GroupId groupId) {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() -> {
-			try {
+			PrivateGroup g = privateGroupManager.getPrivateGroup(groupId);
-				PrivateGroup g = privateGroupManager.getPrivateGroup(groupId);
+			privateGroup.postValue(g);
-				privateGroup.postValue(g);
+			Author author = identityManager.getLocalAuthor();
-				Author author = identityManager.getLocalAuthor();
+			isCreator.postValue(g.getCreator().equals(author));
-				isCreator.postValue(g.getCreator().equals(author));
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
 		});
 	}
 
@@ -190,18 +184,14 @@ class GroupViewModel extends ThreadListViewModel<GroupMessageItem> {
 	@Override
 	public void createAndStoreMessage(String text,
 			@Nullable MessageId parentId) {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() -> {
-			try {
+			LocalAuthor author = identityManager.getLocalAuthor();
-				LocalAuthor author = identityManager.getLocalAuthor();
+			MessageId previousMsgId =
-				MessageId previousMsgId =
+					privateGroupManager.getPreviousMsgId(groupId);
-						privateGroupManager.getPreviousMsgId(groupId);
+			GroupCount count = privateGroupManager.getGroupCount(groupId);
-				GroupCount count = privateGroupManager.getGroupCount(groupId);
+			long timestamp = count.getLatestMsgTime();
-				long timestamp = count.getLatestMsgTime();
+			timestamp = max(clock.currentTimeMillis(), timestamp + 1);
-				timestamp = max(clock.currentTimeMillis(), timestamp + 1);
+			createMessage(text, timestamp, parentId, author, previousMsgId);
-				createMessage(text, timestamp, parentId, author, previousMsgId);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
 		});
 	}
 
@@ -217,55 +207,36 @@ class GroupViewModel extends ThreadListViewModel<GroupMessageItem> {
 	}
 
 	private void storePost(GroupMessage msg, String text) {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() -> {
-			try {
+			long start = now();
-				long start = now();
+			GroupMessageHeader header =
-				GroupMessageHeader header =
+					privateGroupManager.addLocalMessage(msg);
-						privateGroupManager.addLocalMessage(msg);
+			addItemAsync(buildItem(header, text));
-				addItemAsync(buildItem(header, text));
+			logDuration(LOG, "Storing group message", start);
-				logDuration(LOG, "Storing group message", start);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
 		});
 	}
 
 	@Override
 	protected void markItemRead(GroupMessageItem item) {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() ->
-			try {
+				privateGroupManager.setReadFlag(groupId, item.getId(), true));
-				privateGroupManager.setReadFlag(groupId, item.getId(), true);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
-		});
 	}
 
 	public void loadSharingContacts() {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(true, txn -> {
-			try {
+			Collection<GroupMember> members =
-				Collection<GroupMember> members =
+					privateGroupManager.getMembers(txn, groupId);
-						privateGroupManager.getMembers(groupId);
+			Collection<ContactId> contactIds = new ArrayList<>();
-				Collection<ContactId> contactIds = new ArrayList<>();
+			for (GroupMember m : members) {
-				for (GroupMember m : members) {
+				if (m.getContactId() != null) contactIds.add(m.getContactId());
-					if (m.getContactId() != null)
-						contactIds.add(m.getContactId());
-				}
-				sharingController.addAll(contactIds);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
 			}
+			txn.attach(() -> sharingController.addAll(contactIds));
 		});
 	}
 
 	void deletePrivateGroup() {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() ->
-			try {
+				privateGroupManager.removePrivateGroup(groupId));
-				privateGroupManager.removePrivateGroup(groupId);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
-		});
 	}
 
 	LiveData<PrivateGroup> getPrivateGroup() {

briar-android/src/main/java/org/briarproject/briar/android/privategroup/list/GroupListViewModel.java

@@ -2,7 +2,6 @@ package org.briarproject.briar.android.privategroup.list;
 
 import android.app.Application;
 
-import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Transaction;
@@ -49,10 +48,8 @@ import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
 
 import static java.util.Objects.requireNonNull;
-import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
-import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.now;
 import static org.briarproject.briar.api.privategroup.PrivateGroupManager.CLIENT_ID;
 
@@ -200,25 +197,17 @@ class GroupListViewModel extends DbViewModel implements EventListener {
 	}
 
 	void removeGroup(GroupId g) {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() -> {
-			try {
+			long start = now();
-				long start = now();
+			groupManager.removePrivateGroup(g);
-				groupManager.removePrivateGroup(g);
+			logDuration(LOG, "Removing group", start);
-				logDuration(LOG, "Removing group", start);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
 		});
 	}
 
 	void loadNumInvitations() {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() -> {
-			try {
+			int i = groupInvitationManager.getInvitations().size();
-				int i = groupInvitationManager.getInvitations().size();
+			numInvitations.postValue(i);
-				numInvitations.postValue(i);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
 		});
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/sharing/SharingController.java

@@ -1,7 +1,6 @@
 package org.briarproject.briar.android.sharing;
 
 import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
@@ -28,7 +27,7 @@ public interface SharingController {
 	/**
 	 * Adds a collection of contacts to be tracked.
 	 */
-	@DatabaseExecutor
+	@UiThread
 	void addAll(Collection<ContactId> contacts);
 
 	/**

briar-android/src/main/java/org/briarproject/briar/android/sharing/SharingControllerImpl.java

@@ -2,14 +2,12 @@ package org.briarproject.briar.android.sharing;
 
 import org.briarproject.bramble.api.connection.ConnectionRegistry;
 import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.event.ContactConnectedEvent;
 import org.briarproject.bramble.api.plugin.event.ContactDisconnectedEvent;
-import org.briarproject.bramble.api.system.AndroidExecutor;
 
 import java.util.Collection;
 import java.util.HashSet;
@@ -26,7 +24,6 @@ public class SharingControllerImpl implements SharingController, EventListener {
 
 	private final EventBus eventBus;
 	private final ConnectionRegistry connectionRegistry;
-	private final AndroidExecutor executor;
 
 	// UI thread
 	private final Set<ContactId> contacts = new HashSet<>();
@@ -35,11 +32,9 @@ public class SharingControllerImpl implements SharingController, EventListener {
 
 	@Inject
 	SharingControllerImpl(EventBus eventBus,
-			ConnectionRegistry connectionRegistry,
+			ConnectionRegistry connectionRegistry) {
-			AndroidExecutor executor) {
 		this.eventBus = eventBus;
 		this.connectionRegistry = connectionRegistry;
-		this.executor = executor;
 		eventBus.addListener(this);
 	}
 
@@ -78,13 +73,11 @@ public class SharingControllerImpl implements SharingController, EventListener {
 		return online;
 	}
 
+	@UiThread
 	@Override
-	@DatabaseExecutor
 	public void addAll(Collection<ContactId> c) {
-		executor.runOnUiThread(() -> {
+		contacts.addAll(c);
-			contacts.addAll(c);
+		updateLiveData();
-			updateLiveData();
-		});
 	}
 
 	@UiThread

briar-android/src/main/java/org/briarproject/briar/android/threaded/ThreadListViewModel.java

@@ -44,10 +44,8 @@ import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
 
 import static java.util.logging.Level.INFO;
-import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
-import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.now;
 
 @MethodsNotNullByDefault
@@ -145,16 +143,11 @@ public abstract class ThreadListViewModel<I extends ThreadItem>
 	}
 
 	private void loadStoredMessageId() {
-		runOnDbThread(() -> {
+		runOnDbThreadOrLogException(() -> {
-			try {
+			storedMessageId.set(messageTracker.loadStoredMessageId(groupId));
-				storedMessageId
+			if (LOG.isLoggable(INFO)) {
-						.set(messageTracker.loadStoredMessageId(groupId));
+				LOG.info("Loaded last top visible message id " +
-				if (LOG.isLoggable(INFO)) {
+						storedMessageId);
-					LOG.info("Loaded last top visible message id " +
-							storedMessageId);
-				}
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
 			}
 		});
 	}
@@ -229,13 +222,10 @@ public abstract class ThreadListViewModel<I extends ThreadItem>
 	}
 
 	void storeMessageId(@Nullable MessageId messageId) {
-		if (messageId != null) runOnDbThread(() -> {
+		if (messageId != null) {
-			try {
+			runOnDbThreadOrLogException(() ->
-				messageTracker.storeMessageId(groupId, messageId);
+					messageTracker.storeMessageId(groupId, messageId));
-			} catch (DbException e) {
+		}
-				logException(LOG, WARNING, e);
-			}
-		});
 	}
 
 	protected abstract void markItemRead(I item);

briar-android/src/main/java/org/briarproject/briar/android/viewmodel/DbViewModel.java

@@ -2,9 +2,11 @@ package org.briarproject.briar.android.viewmodel;
 
 import android.app.Application;
 
+import org.briarproject.bramble.api.ThrowingRunnable;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 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.Transaction;
 import org.briarproject.bramble.api.db.TransactionManager;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
@@ -23,6 +25,7 @@ import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.annotation.UiThread;
 import androidx.arch.core.util.Function;
+import androidx.core.util.Consumer;
 import androidx.lifecycle.AndroidViewModel;
 import androidx.lifecycle.LiveData;
 import androidx.recyclerview.widget.RecyclerView;
@@ -57,14 +60,15 @@ public abstract class DbViewModel extends AndroidViewModel {
 	}
 
 	/**
-	 * Runs the given task on the {@link DatabaseExecutor}
+	 * Waits for the DB to open and runs the given task on the
-	 * and waits for the DB to open.
+	 * {@link DatabaseExecutor}.
 	 * <p>
 	 * If you need a list of items to be displayed in a
 	 * {@link RecyclerView.Adapter},
 	 * use {@link #loadList(DbCallable, UiConsumer)} instead.
 	 */
-	protected void runOnDbThread(Runnable task) {
+	protected void runOnDbThread(ThrowingRunnable<Exception> task,
+			Consumer<Exception> err) {
 		dbExecutor.execute(() -> {
 			try {
 				lifecycleManager.waitForDatabase();
@@ -72,10 +76,63 @@ public abstract class DbViewModel extends AndroidViewModel {
 			} catch (InterruptedException e) {
 				LOG.warning("Interrupted while waiting for database");
 				Thread.currentThread().interrupt();
+			} catch (Exception e) {
+				err.accept(e);
 			}
 		});
 	}
 
+	/**
+	 * Waits for the DB to open and runs the given task on the
+	 * {@link DatabaseExecutor}.
+	 * <p>
+	 * If you need a list of items to be displayed in a
+	 * {@link RecyclerView.Adapter},
+	 * use {@link #loadList(DbCallable, UiConsumer)} instead.
+	 */
+	protected void runOnDbThread(boolean readOnly,
+			DbRunnable<Exception> task, Consumer<Exception> err) {
+		dbExecutor.execute(() -> {
+			try {
+				lifecycleManager.waitForDatabase();
+				db.transaction(readOnly, task);
+			} catch (InterruptedException e) {
+				LOG.warning("Interrupted while waiting for database");
+				Thread.currentThread().interrupt();
+			} catch (Exception e) {
+				err.accept(e);
+			}
+		});
+	}
+
+	/**
+	 * Waits for the DB to open and runs the given task on the
+	 * {@link DatabaseExecutor}. If the task throws a {@link DbException}
+	 * it's caught and logged.
+	 * <p>
+	 * If you need a list of items to be displayed in a
+	 * {@link RecyclerView.Adapter},
+	 * use {@link #loadList(DbCallable, UiConsumer)} instead.
+	 */
+	protected void runOnDbThreadOrLogException(boolean readOnly,
+			DbRunnable<Exception> task) {
+		runOnDbThread(readOnly, task, e -> logException(LOG, WARNING, e));
+	}
+
+	/**
+	 * Waits for the DB to open and runs the given task on the
+	 * {@link DatabaseExecutor}. If the task throws a {@link DbException}
+	 * it's caught and logged.
+	 * <p>
+	 * If you need a list of items to be displayed in a
+	 * {@link RecyclerView.Adapter},
+	 * use {@link #loadList(DbCallable, UiConsumer)} instead.
+	 */
+	protected void runOnDbThreadOrLogException(
+			ThrowingRunnable<Exception> task) {
+		runOnDbThread(task, e -> logException(LOG, WARNING, e));
+	}
+
 	/**
 	 * Loads a list of items on the {@link DatabaseExecutor} within a single
 	 * {@link Transaction} and publishes it as a {@link LiveResult}

briar-api/src/main/java/org/briarproject/briar/api/privategroup/PrivateGroupManager.java

@@ -129,6 +129,12 @@ public interface PrivateGroupManager {
 	 */
 	Collection<GroupMember> getMembers(GroupId g) throws DbException;
 
+	/**
+	 * Returns all members of the given private group.
+	 */
+	Collection<GroupMember> getMembers(Transaction txn, GroupId g)
+			throws DbException;
+
 	/**
 	 * Returns true if the given author is a member of the given private group.
 	 */

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

@@ -3,6 +3,7 @@ package org.briarproject.briar.api.sharing;
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.briar.api.client.SessionId;
@@ -45,6 +46,12 @@ public interface SharingManager<S extends Shareable>
 	 */
 	Collection<Contact> getSharedWith(GroupId g) throws DbException;
 
+	/**
+	 * Returns all contacts with whom the given group is shared.
+	 */
+	Collection<Contact> getSharedWith(Transaction txn, GroupId g)
+			throws DbException;
+
 	/**
 	 * Returns true if the group not already shared and no invitation is open
 	 */

briar-core/src/main/java/org/briarproject/briar/privategroup/PrivateGroupManagerImpl.java

@@ -407,36 +407,36 @@ class PrivateGroupManagerImpl extends BdfIncomingMessageHook
 	}
 
 	@Override
-	public Collection<GroupMember> getMembers(GroupId g) throws DbException {
+	public Collection<GroupMember> getMembers(GroupId g)
-		Transaction txn = db.startTransaction(true);
+			throws DbException {
-		try {
+		return db.transactionWithResult(true, txn -> getMembers(txn, g));
-			Collection<GroupMember> members = new ArrayList<>();
-			Map<Author, Visibility> authors = getMembers(txn, g);
-			LocalAuthor la = identityManager.getLocalAuthor(txn);
-			PrivateGroup privateGroup = getPrivateGroup(txn, g);
-			for (Entry<Author, Visibility> m : authors.entrySet()) {
-				Author a = m.getKey();
-				AuthorInfo authorInfo =
-						authorManager.getAuthorInfo(txn, a.getId());
-				Status status = authorInfo.getStatus();
-				Visibility v = m.getValue();
-				ContactId c = null;
-				if (v != INVISIBLE &&
-						(status == VERIFIED || status == UNVERIFIED)) {
-					c = contactManager.getContact(txn, a.getId(), la.getId())
-							.getId();
-				}
-				boolean isCreator = privateGroup.getCreator().equals(a);
-				members.add(new GroupMember(a, authorInfo, isCreator, c, v));
-			}
-			db.commitTransaction(txn);
-			return members;
-		} finally {
-			db.endTransaction(txn);
-		}
 	}
 
-	private Map<Author, Visibility> getMembers(Transaction txn, GroupId g)
+	@Override
+	public Collection<GroupMember> getMembers(Transaction txn, GroupId g)
+			throws DbException {
+		Collection<GroupMember> members = new ArrayList<>();
+		Map<Author, Visibility> authors = getMemberAuthors(txn, g);
+		LocalAuthor la = identityManager.getLocalAuthor(txn);
+		PrivateGroup privateGroup = getPrivateGroup(txn, g);
+		for (Entry<Author, Visibility> m : authors.entrySet()) {
+			Author a = m.getKey();
+			AuthorInfo authorInfo = authorManager.getAuthorInfo(txn, a.getId());
+			Status status = authorInfo.getStatus();
+			Visibility v = m.getValue();
+			ContactId c = null;
+			if (v != INVISIBLE &&
+					(status == VERIFIED || status == UNVERIFIED)) {
+				c = contactManager.getContact(txn, a.getId(), la.getId())
+						.getId();
+			}
+			boolean isCreator = privateGroup.getCreator().equals(a);
+			members.add(new GroupMember(a, authorInfo, isCreator, c, v));
+		}
+		return members;
+	}
+
+	private Map<Author, Visibility> getMemberAuthors(Transaction txn, GroupId g)
 			throws DbException {
 		try {
 			BdfDictionary meta =
@@ -458,7 +458,7 @@ class PrivateGroupManagerImpl extends BdfIncomingMessageHook
 	@Override
 	public boolean isMember(Transaction txn, GroupId g, Author a)
 			throws DbException {
-		for (Author member : getMembers(txn, g).keySet()) {
+		for (Author member : getMemberAuthors(txn, g).keySet()) {
 			if (member.equals(a)) return true;
 		}
 		return false;

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

@@ -426,17 +426,17 @@ abstract class SharingManagerImpl<S extends Shareable>
 
 	@Override
 	public Collection<Contact> getSharedWith(GroupId g) throws DbException {
+		return db.transactionWithResult(true, txn -> getSharedWith(txn, g));
+	}
+
+	@Override
+	public Collection<Contact> getSharedWith(Transaction txn, GroupId g)
+			throws DbException {
 		// TODO report also pending invitations
 		Collection<Contact> contacts = new ArrayList<>();
-		Transaction txn = db.startTransaction(true);
+		for (Contact c : db.getContacts(txn)) {
-		try {
+			if (db.getGroupVisibility(txn, c.getId(), g) == SHARED)
-			for (Contact c : db.getContacts(txn)) {
+				contacts.add(c);
-				if (db.getGroupVisibility(txn, c.getId(), g) == SHARED)
-					contacts.add(c);
-			}
-			db.commitTransaction(txn);
-		} finally {
-			db.endTransaction(txn);
 		}
 		return contacts;
 	}

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

@@ -20,10 +20,10 @@ import org.junit.Test;
 
 import java.util.Collection;
 
-import static org.briarproject.briar.api.identity.AuthorInfo.Status.VERIFIED;
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
 import static org.briarproject.bramble.test.TestUtils.getRandomBytes;
 import static org.briarproject.bramble.test.TestUtils.getRandomId;
+import static org.briarproject.briar.api.identity.AuthorInfo.Status.VERIFIED;
 import static org.briarproject.briar.api.privategroup.Visibility.INVISIBLE;
 import static org.briarproject.briar.api.privategroup.Visibility.REVEALED_BY_CONTACT;
 import static org.briarproject.briar.api.privategroup.Visibility.REVEALED_BY_US;