Load list of private groups in a single DB transaction

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

@@ -14,6 +14,7 @@ import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.crypto.CryptoExecutor;
 import org.briarproject.bramble.api.crypto.PasswordStrengthEstimator;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
+import org.briarproject.bramble.api.db.TransactionManager;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementTask;
@@ -85,6 +86,8 @@ public interface AndroidComponent
 	@DatabaseExecutor
 	Executor databaseExecutor();
 
+	TransactionManager transactionManager();
+
 	MessageTracker messageTracker();
 
 	LifecycleManager lifecycleManager();

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

@@ -4,6 +4,8 @@ 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.NoSuchGroupException;
+import org.briarproject.bramble.api.db.Transaction;
+import org.briarproject.bramble.api.db.TransactionManager;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.event.EventListener;
@@ -55,6 +57,7 @@ class GroupListControllerImpl extends DbControllerImpl
 	private static final Logger LOG =
 			Logger.getLogger(GroupListControllerImpl.class.getName());
 
+	private final TransactionManager db;
 	private final PrivateGroupManager groupManager;
 	private final GroupInvitationManager groupInvitationManager;
 	private final ContactManager contactManager;
@@ -67,11 +70,14 @@ class GroupListControllerImpl extends DbControllerImpl
 
 	@Inject
 	GroupListControllerImpl(@DatabaseExecutor Executor dbExecutor,
-			LifecycleManager lifecycleManager, PrivateGroupManager groupManager,
+			LifecycleManager lifecycleManager,
+			TransactionManager db,
+			PrivateGroupManager groupManager,
 			GroupInvitationManager groupInvitationManager,
 			ContactManager contactManager,
 			AndroidNotificationManager notificationManager, EventBus eventBus) {
 		super(dbExecutor, lifecycleManager);
+		this.db = db;
 		this.groupManager = groupManager;
 		this.groupInvitationManager = groupInvitationManager;
 		this.contactManager = contactManager;
@@ -140,32 +146,7 @@ class GroupListControllerImpl extends DbControllerImpl
 			ResultExceptionHandler<Collection<GroupItem>, DbException> handler) {
 		runOnDbThread(() -> {
 			try {
-				long start = now();
+				db.transaction(true, txn -> loadGroups(txn, handler));
-				Collection<PrivateGroup> groups =
-						groupManager.getPrivateGroups();
-				List<GroupItem> items = new ArrayList<>(groups.size());
-				Map<AuthorId, AuthorInfo> authorInfos = new HashMap<>();
-				for (PrivateGroup g : groups) {
-					try {
-						GroupId id = g.getId();
-						AuthorId authorId = g.getCreator().getId();
-						AuthorInfo authorInfo;
-						if (authorInfos.containsKey(authorId)) {
-							authorInfo = authorInfos.get(authorId);
-						} else {
-							authorInfo = contactManager.getAuthorInfo(authorId);
-							authorInfos.put(authorId, authorInfo);
-						}
-						GroupCount count = groupManager.getGroupCount(id);
-						boolean dissolved = groupManager.isDissolved(id);
-						items.add(
-								new GroupItem(g, authorInfo, count, dissolved));
-					} catch (NoSuchGroupException e) {
-						// Continue
-					}
-				}
-				logDuration(LOG, "Loading groups", start);
-				handler.onResult(items);
 			} catch (DbException e) {
 				logException(LOG, WARNING, e);
 				handler.onException(e);
@@ -173,6 +154,36 @@ class GroupListControllerImpl extends DbControllerImpl
 		});
 	}
 
+	@DatabaseExecutor
+	private void loadGroups(Transaction txn,
+			ResultExceptionHandler<Collection<GroupItem>, DbException> handler)
+			throws DbException {
+		long start = now();
+		Collection<PrivateGroup> groups = groupManager.getPrivateGroups(txn);
+		List<GroupItem> items = new ArrayList<>(groups.size());
+		Map<AuthorId, AuthorInfo> authorInfos = new HashMap<>();
+		for (PrivateGroup g : groups) {
+			try {
+				GroupId id = g.getId();
+				AuthorId authorId = g.getCreator().getId();
+				AuthorInfo authorInfo;
+				if (authorInfos.containsKey(authorId)) {
+					authorInfo = authorInfos.get(authorId);
+				} else {
+					authorInfo = contactManager.getAuthorInfo(txn, authorId);
+					authorInfos.put(authorId, authorInfo);
+				}
+				GroupCount count = groupManager.getGroupCount(txn, id);
+				boolean dissolved = groupManager.isDissolved(txn, id);
+				items.add(new GroupItem(g, authorInfo, count, dissolved));
+			} catch (NoSuchGroupException e) {
+				// Continue
+			}
+		}
+		logDuration(LOG, "Loading groups", start);
+		handler.onResult(items);
+	}
+
 	@Override
 	public void removeGroup(GroupId g, ExceptionHandler<DbException> handler) {
 		runOnDbThread(() -> {

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

@@ -66,6 +66,11 @@ public interface PrivateGroupManager {
 	 */
 	void markGroupDissolved(Transaction txn, GroupId g) throws DbException;
 
+	/**
+	 * Returns true if the given private group has been dissolved.
+	 */
+	boolean isDissolved(Transaction txn, GroupId g) throws DbException;
+
 	/**
 	 * Returns true if the given private group has been dissolved.
 	 */
@@ -91,6 +96,12 @@ public interface PrivateGroupManager {
 	 */
 	Collection<PrivateGroup> getPrivateGroups() throws DbException;
 
+	/**
+	 * Returns all private groups the user is a member of.
+	 */
+	Collection<PrivateGroup> getPrivateGroups(Transaction txn)
+			throws DbException;
+
 	/**
 	 * Returns the text of the private group message with the given ID.
 	 */
@@ -111,6 +122,11 @@ public interface PrivateGroupManager {
 	 */
 	boolean isMember(Transaction txn, GroupId g, Author a) throws DbException;
 
+	/**
+	 * Returns the group count for the given private group.
+	 */
+	GroupCount getGroupCount(Transaction txn, GroupId g) throws DbException;
+
 	/**
 	 * Returns the group count for the given private group.
 	 */

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

@@ -270,22 +270,31 @@ class PrivateGroupManagerImpl extends BdfIncomingMessageHook
 	}
 
 	@Override
-	public Collection<PrivateGroup> getPrivateGroups() throws DbException {
+	public Collection<PrivateGroup> getPrivateGroups(Transaction txn)
-		Collection<Group> groups;
+			throws DbException {
-		Transaction txn = db.startTransaction(true);
+		Collection<Group> groups = db.getGroups(txn, CLIENT_ID, MAJOR_VERSION);
+		Collection<PrivateGroup> privateGroups = new ArrayList<>(groups.size());
 		try {
-			groups = db.getGroups(txn, CLIENT_ID, MAJOR_VERSION);
-			db.commitTransaction(txn);
-		} finally {
-			db.endTransaction(txn);
-		}
-		try {
-			Collection<PrivateGroup> privateGroups =
-					new ArrayList<>(groups.size());
 			for (Group g : groups) {
 				privateGroups.add(privateGroupFactory.parsePrivateGroup(g));
 			}
-			return privateGroups;
+		} catch (FormatException e) {
+			throw new DbException(e);
+		}
+		return privateGroups;
+	}
+
+	@Override
+	public Collection<PrivateGroup> getPrivateGroups() throws DbException {
+		return db.transactionWithResult(true, this::getPrivateGroups);
+	}
+
+	@Override
+	public boolean isDissolved(Transaction txn, GroupId g) throws DbException {
+		try {
+			BdfDictionary meta =
+					clientHelper.getGroupMetadataAsDictionary(txn, g);
+			return meta.getBoolean(GROUP_KEY_DISSOLVED);
 		} catch (FormatException e) {
 			throw new DbException(e);
 		}
@@ -293,12 +302,7 @@ class PrivateGroupManagerImpl extends BdfIncomingMessageHook
 
 	@Override
 	public boolean isDissolved(GroupId g) throws DbException {
-		try {
+		return db.transactionWithResult(true, txn -> isDissolved(txn, g));
-			BdfDictionary meta = clientHelper.getGroupMetadataAsDictionary(g);
-			return meta.getBoolean(GROUP_KEY_DISSOLVED);
-		} catch (FormatException e) {
-			throw new DbException(e);
-		}
 	}
 
 	@Override
@@ -403,7 +407,8 @@ class PrivateGroupManagerImpl extends BdfIncomingMessageHook
 			PrivateGroup privateGroup = getPrivateGroup(txn, g);
 			for (Entry<Author, Visibility> m : authors.entrySet()) {
 				Author a = m.getKey();
-				AuthorInfo authorInfo = contactManager.getAuthorInfo(txn, a.getId());
+				AuthorInfo authorInfo =
+						contactManager.getAuthorInfo(txn, a.getId());
 				Status status = authorInfo.getStatus();
 				Visibility v = m.getValue();
 				ContactId c = null;
@@ -450,6 +455,12 @@ class PrivateGroupManagerImpl extends BdfIncomingMessageHook
 		return false;
 	}
 
+	@Override
+	public GroupCount getGroupCount(Transaction txn, GroupId g)
+			throws DbException {
+		return messageTracker.getGroupCount(txn, g);
+	}
+
 	@Override
 	public GroupCount getGroupCount(GroupId g) throws DbException {
 		return messageTracker.getGroupCount(g);