Don't store subscription or transport updates that are older than those already received. Also some small changes to DatabaseComponent impls for readability.

2026-02-14 03:39:05 +01:00 · 2011-07-14 13:53:13 +01:00
parent 836d30f6df
commit fcedc34d10
10 changed files with 397 additions and 216 deletions
--- a/components/net/sf/briar/db/Database.java
+++ b/components/net/sf/briar/db/Database.java
@@ -81,7 +81,8 @@ interface Database<T> {
 	 * <p>
 	 * Locking: contacts write, transports write.
 	 */
-	ContactId addContact(T txn, Map<String, String> transports) throws DbException;
+	ContactId addContact(T txn, Map<String, String> transports)
+	throws DbException;

 	/**
 	 * Returns false if the given message is already in the database. Otherwise
@@ -96,7 +97,8 @@ interface Database<T> {
 	 * <p>
 	 * Locking: contacts read, messages read, messageStatuses write.
 	 */
-	void addOutstandingBatch(T txn, ContactId c, BatchId b, Set<MessageId> sent) throws DbException;
+	void addOutstandingBatch(T txn, ContactId c, BatchId b, Set<MessageId> sent)
+	throws DbException;

 	/**
 	 * Subscribes to the given group.
@@ -169,7 +171,8 @@ interface Database<T> {
 	 * <p>
 	 * Locking: messages read.
 	 */
-	Iterable<MessageId> getMessagesByAuthor(T txn, AuthorId a) throws DbException;
+	Iterable<MessageId> getMessagesByAuthor(T txn, AuthorId a)
+	throws DbException;

 	/**
 	 * Returns the number of children of the message identified by the given
@@ -216,7 +219,8 @@ interface Database<T> {
 	 * <p>
 	 * Locking: contacts read, messages read, messageStatuses read.
 	 */
-	Iterable<MessageId> getSendableMessages(T txn, ContactId c, long capacity) throws DbException;
+	Iterable<MessageId> getSendableMessages(T txn, ContactId c, long capacity)
+	throws DbException;

 	/**
 	 * Returns the groups to which the user subscribes.
@@ -225,6 +229,13 @@ interface Database<T> {
 	 */
 	Set<GroupId> getSubscriptions(T txn) throws DbException;

+	/**
+	 * Returns the groups to which the given contact subscribes.
+	 * <p>
+	 * Locking: contacts read, subscriptions read.
+	 */
+	Set<GroupId> getSubscriptions(T txn, ContactId c) throws DbException;
+
 	/**
 	 * Returns the local transport details.
 	 * <p>
@@ -308,15 +319,17 @@ interface Database<T> {
 	 * <p>
 	 * Locking: contacts read, messages read, messageStatuses write.
 	 */
-	void setStatus(T txn, ContactId c, MessageId m, Status s) throws DbException;
+	void setStatus(T txn, ContactId c, MessageId m, Status s)
+	throws DbException;

 	/**
 	 * Sets the subscriptions for the given contact, replacing any existing
-	 * subscriptions.
+	 * subscriptions unless the existing subscriptions have a newer timestamp.
 	 * <p>
-	 * Locking: contacts read, subscriptions write.
+	 * Locking: contacts write, subscriptions write.
 	 */
-	void setSubscriptions(T txn, ContactId c, Set<GroupId> subs) throws DbException;
+	void setSubscriptions(T txn, ContactId c, Set<GroupId> subs, long timestamp)
+	throws DbException;

 	/**
 	 * Sets the local transport details, replacing any existing transport
@@ -324,13 +337,15 @@ interface Database<T> {
 	 * <p>
 	 * Locking: transports write.
 	 */
-	void setTransports(T txn, Map<String, String> transports) throws DbException;
+	void setTransports(T txn, Map<String, String> transports)
+	throws DbException;

 	/**
 	 * Sets the transport details for the given contact, replacing any existing
-	 * transport details.
+	 * transport details unless the existing details have a newer timestamp.
 	 * <p>
-	 * Locking: contacts read, transports write.
+	 * Locking: contacts write, transports write.
 	 */
-	void setTransports(T txn, ContactId c, Map<String, String> transports) throws DbException;
+	void setTransports(T txn, ContactId c, Map<String, String> transports,
+			long timestamp) throws DbException;
 }
--- a/components/net/sf/briar/db/DatabaseModule.java
+++ b/components/net/sf/briar/db/DatabaseModule.java
@@ -12,8 +12,10 @@ public class DatabaseModule extends AbstractModule {
 	@Override
 	protected void configure() {
 		bind(Database.class).to(H2Database.class);
-		bind(DatabaseComponent.class).to(ReadWriteLockDatabaseComponent.class).in(Singleton.class);
-		bind(Password.class).annotatedWith(DatabasePassword.class).toInstance(new Password() {
+		bind(DatabaseComponent.class).to(
+				ReadWriteLockDatabaseComponent.class).in(Singleton.class);
+		bind(Password.class).annotatedWith(DatabasePassword.class).toInstance(
+				new Password() {
 			public char[] getPassword() {
 				return "fixme fixme".toCharArray();
 			}
--- a/components/net/sf/briar/db/JdbcDatabase.java
+++ b/components/net/sf/briar/db/JdbcDatabase.java
@@ -38,15 +38,15 @@ abstract class JdbcDatabase implements Database<Connection> {

 	private static final String CREATE_LOCAL_SUBSCRIPTIONS =
 		"CREATE TABLE localSubscriptions"
-		+ " (groupId XXXX NOT NULL,"
+		+ " (groupId HASH NOT NULL,"
 		+ " PRIMARY KEY (groupId))";

 	private static final String CREATE_MESSAGES =
 		"CREATE TABLE messages"
-		+ " (messageId XXXX NOT NULL,"
-		+ " parentId XXXX NOT NULL,"
-		+ " groupId XXXX NOT NULL,"
-		+ " authorId XXXX NOT NULL,"
+		+ " (messageId HASH NOT NULL,"
+		+ " parentId HASH NOT NULL,"
+		+ " groupId HASH NOT NULL,"
+		+ " authorId HASH NOT NULL,"
 		+ " timestamp BIGINT NOT NULL,"
 		+ " size INT NOT NULL,"
 		+ " raw BLOB NOT NULL,"
@@ -70,11 +70,13 @@ abstract class JdbcDatabase implements Database<Connection> {
 	private static final String CREATE_CONTACTS =
 		"CREATE TABLE contacts"
 		+ " (contactId INT NOT NULL,"
+		+ " subscriptionsTimestamp TIMESTAMP NOT NULL,"
+		+ " transportsTimestamp TIMESTAMP NOT NULL,"
 		+ " PRIMARY KEY (contactId))";

 	private static final String CREATE_BATCHES_TO_ACK =
 		"CREATE TABLE batchesToAck"
-		+ " (batchId XXXX NOT NULL,"
+		+ " (batchId HASH NOT NULL,"
 		+ " contactId INT NOT NULL,"
 		+ " PRIMARY KEY (batchId),"
 		+ " FOREIGN KEY (contactId) REFERENCES contacts (contactId)"
@@ -83,16 +85,16 @@ abstract class JdbcDatabase implements Database<Connection> {
 	private static final String CREATE_CONTACT_SUBSCRIPTIONS =
 		"CREATE TABLE contactSubscriptions"
 		+ " (contactId INT NOT NULL,"
-		+ " groupId XXXX NOT NULL,"
+		+ " groupId HASH NOT NULL,"
 		+ " PRIMARY KEY (contactId, groupId),"
 		+ " FOREIGN KEY (contactId) REFERENCES contacts (contactId)"
 		+ " ON DELETE CASCADE)";

 	private static final String CREATE_OUTSTANDING_BATCHES =
 		"CREATE TABLE outstandingBatches"
-		+ " (batchId XXXX NOT NULL,"
+		+ " (batchId HASH NOT NULL,"
 		+ " contactId INT NOT NULL,"
-		+ " timestamp YYYY NOT NULL,"
+		+ " timestamp TIMESTAMP NOT NULL,"
 		+ " passover INT NOT NULL,"
 		+ " PRIMARY KEY (batchId),"
 		+ " FOREIGN KEY (contactId) REFERENCES contacts (contactId)"
@@ -100,9 +102,9 @@ abstract class JdbcDatabase implements Database<Connection> {

 	private static final String CREATE_OUTSTANDING_MESSAGES =
 		"CREATE TABLE outstandingMessages"
-		+ " (batchId XXXX NOT NULL,"
+		+ " (batchId HASH NOT NULL,"
 		+ " contactId INT NOT NULL,"
-		+ " messageId XXXX NOT NULL,"
+		+ " messageId HASH NOT NULL,"
 		+ " PRIMARY KEY (batchId, messageId),"
 		+ " FOREIGN KEY (batchId) REFERENCES outstandingBatches (batchId)"
 		+ " ON DELETE CASCADE,"
@@ -117,13 +119,13 @@ abstract class JdbcDatabase implements Database<Connection> {

 	private static final String CREATE_RATINGS =
 		"CREATE TABLE ratings"
-		+ " (authorId XXXX NOT NULL,"
+		+ " (authorId HASH NOT NULL,"
 		+ " rating SMALLINT NOT NULL,"
 		+ " PRIMARY KEY (authorId))";

 	private static final String CREATE_STATUSES =
 		"CREATE TABLE statuses"
-		+ " (messageId XXXX NOT NULL,"
+		+ " (messageId HASH NOT NULL,"
 		+ " contactId INT NOT NULL,"
 		+ " status SMALLINT NOT NULL,"
 		+ " PRIMARY KEY (messageId, contactId),"
@@ -157,7 +159,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		Logger.getLogger(JdbcDatabase.class.getName());

 	// Different database libraries use different names for certain types
-	private final String hashType, bigIntType;
+	private final String hashType, timestampType;
 	private final LinkedList<Connection> connections =
 		new LinkedList<Connection>(); // Locking: self

@@ -166,9 +168,9 @@ abstract class JdbcDatabase implements Database<Connection> {

 	protected abstract Connection createConnection() throws SQLException;

-	JdbcDatabase(String hashType, String bigIntType) {
+	JdbcDatabase(String hashType, String timestampType) {
 		this.hashType = hashType;
-		this.bigIntType = bigIntType;
+		this.timestampType = timestampType;
 	}

 	protected void open(boolean resume, File dir, String driverClass)
@@ -254,7 +256,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}

 	private String insertTypeNames(String s) {
-		return s.replaceAll("XXXX", hashType).replaceAll("YYYY", bigIntType);
+		s = s.replaceAll("HASH", hashType);
+		return s.replaceAll("TIMESTAMP", timestampType);
 	}

 	private void tryToClose(Connection c) {
@@ -388,9 +391,13 @@ abstract class JdbcDatabase implements Database<Connection> {
 			rs.close();
 			ps.close();
 			// Create a new contact row
-			sql = "INSERT INTO contacts (contactId) VALUES (?)";
+			sql = "INSERT INTO contacts"
+				+ " (contactId, subscriptionsTimestamp, transportsTimestamp)"
+				+ " VALUES (?, ?, ?)";
 			ps = txn.prepareStatement(sql);
 			ps.setInt(1, c.getInt());
+			ps.setLong(2, 0L);
+			ps.setLong(3, 0L);
 			int rowsAffected = ps.executeUpdate();
 			assert rowsAffected == 1;
 			ps.close();
@@ -955,6 +962,29 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}

+	public Set<GroupId> getSubscriptions(Connection txn, ContactId c)
+	throws DbException {
+		PreparedStatement ps = null;
+		ResultSet rs = null;
+		try {
+			String sql = "SELECT groupId FROM contactSubscriptions"
+				+ " WHERE contactId = ?";
+			ps = txn.prepareStatement(sql);
+			ps.setInt(1, c.getInt());
+			rs = ps.executeQuery();
+			Set<GroupId> ids = new HashSet<GroupId>();
+			while(rs.next()) ids.add(new GroupId(rs.getBytes(1)));
+			rs.close();
+			ps.close();
+			return ids;
+		} catch(SQLException e) {
+			tryToClose(rs);
+			tryToClose(ps);
+			tryToClose(txn);
+			throw new DbException(e);
+		}
+	}
+
 	public Map<String, String> getTransports(Connection txn)
 	throws DbException {
 		PreparedStatement ps = null;
@@ -1279,12 +1309,27 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}

-	public void setSubscriptions(Connection txn, ContactId c, Set<GroupId> subs)
-	throws DbException {
+	public void setSubscriptions(Connection txn, ContactId c, Set<GroupId> subs,
+			long timestamp) throws DbException {
 		PreparedStatement ps = null;
+		ResultSet rs = null;
 		try {
+			// Return if the timestamp isn't fresh
+			String sql = "SELECT subscriptionsTimestamp FROM contacts"
+				+ " WHERE contactId = ?";
+			ps = txn.prepareStatement(sql);
+			ps.setInt(1, c.getInt());
+			rs = ps.executeQuery();
+			boolean found = rs.next();
+			assert found;
+			long lastTimestamp = rs.getLong(1);
+			boolean more = rs.next();
+			assert !more;
+			rs.close();
+			ps.close();
+			if(lastTimestamp >= timestamp) return;
 			// Delete any existing subscriptions
-			String sql = "DELETE FROM contactSubscriptions WHERE contactId = ?";
+			sql = "DELETE FROM contactSubscriptions WHERE contactId = ?";
 			ps = txn.prepareStatement(sql);
 			ps.setInt(1, c.getInt());
 			ps.executeUpdate();
@@ -1304,6 +1349,15 @@ abstract class JdbcDatabase implements Database<Connection> {
 				assert rowsAffectedArray[i] == 1;
 			}
 			ps.close();
+			// Update the timestamp
+			sql = "UPDATE contacts SET subscriptionsTimestamp = ?"
+				+ " WHERE contactId = ?";
+			ps = txn.prepareStatement(sql);
+			ps.setLong(1, timestamp);
+			ps.setInt(2, c.getInt());
+			int rowsAffected = ps.executeUpdate();
+			assert rowsAffected == 1;
+			ps.close();
 		} catch(SQLException e) {
 			tryToClose(ps);
 			tryToClose(txn);
@@ -1345,11 +1399,26 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}

 	public void setTransports(Connection txn, ContactId c,
-			Map<String, String> transports) throws DbException {
+			Map<String, String> transports, long timestamp) throws DbException {
 		PreparedStatement ps = null;
+		ResultSet rs = null;
 		try {
+			// Return if the timestamp isn't fresh
+			String sql = "SELECT transportsTimestamp FROM contacts"
+				+ " WHERE contactId = ?";
+			ps = txn.prepareStatement(sql);
+			ps.setInt(1, c.getInt());
+			rs = ps.executeQuery();
+			boolean found = rs.next();
+			assert found;
+			long lastTimestamp = rs.getLong(1);
+			boolean more = rs.next();
+			assert !more;
+			rs.close();
+			ps.close();
+			if(lastTimestamp >= timestamp) return;
 			// Delete any existing transports
-			String sql = "DELETE FROM contactTransports WHERE contactId = ?";
+			sql = "DELETE FROM contactTransports WHERE contactId = ?";
 			ps = txn.prepareStatement(sql);
 			ps.setInt(1, c.getInt());
 			ps.executeUpdate();
@@ -1372,6 +1441,15 @@ abstract class JdbcDatabase implements Database<Connection> {
 				}
 				ps.close();
 			}
+			// Update the timestamp
+			sql = "UPDATE contacts SET transportsTimestamp = ?"
+				+ " WHERE contactId = ?";
+			ps = txn.prepareStatement(sql);
+			ps.setLong(1, timestamp);
+			ps.setInt(2, c.getInt());
+			int rowsAffected = ps.executeUpdate();
+			assert rowsAffected == 1;
+			ps.close();
 		} catch(SQLException e) {
 			tryToClose(ps);
 			tryToClose(txn);
--- a/components/net/sf/briar/db/ReadWriteLockDatabaseComponent.java
+++ b/components/net/sf/briar/db/ReadWriteLockDatabaseComponent.java
@@ -2,6 +2,7 @@ package net.sf.briar.db;

 import java.io.IOException;
 import java.security.GeneralSecurityException;
+import java.security.SignatureException;
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.Iterator;
@@ -192,10 +193,19 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 	public void generateBundle(ContactId c, BundleWriter b) throws DbException,
 	IOException, GeneralSecurityException {
 		if(LOG.isLoggable(Level.FINE)) LOG.fine("Generating bundle for " + c);
-		Set<BatchId> acks;
-		Set<GroupId> subs;
-		Map<String, String> transports;
-		// Add acks
+		Set<BatchId> acks = generateAcks(c);
+		Set<GroupId> subs = generateSubscriptions(c);
+		Map<String, String> transports = generateTransports(c);
+		// Add the header to the bundle
+		b.addHeader(acks, subs, transports);
+		// Add as many messages as possible to the bundle
+		while(generateBatch(c, b));
+		b.finish();
+		if(LOG.isLoggable(Level.FINE)) LOG.fine("Bundle generated");
+		System.gc();
+	}
+
+	private Set<BatchId> generateAcks(ContactId c) throws DbException {
 		contactLock.readLock().lock();
 		try {
 			if(!containsContact(c)) throw new NoSuchContactException();
@@ -203,10 +213,11 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 			try {
 				Txn txn = db.startTransaction();
 				try {
-					acks = db.removeBatchesToAck(txn, c);
+					Set<BatchId> acks = db.removeBatchesToAck(txn, c);
 					if(LOG.isLoggable(Level.FINE))
 						LOG.fine("Added " + acks.size() + " acks");
 					db.commitTransaction(txn);
+					return acks;
 				} catch(DbException e) {
 					db.abortTransaction(txn);
 					throw e;
@@ -217,7 +228,9 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 		} finally {
 			contactLock.readLock().unlock();
 		}
-		// Add subscriptions
+	}
+
+	private Set<GroupId> generateSubscriptions(ContactId c) throws DbException {
 		contactLock.readLock().lock();
 		try {
 			if(!containsContact(c)) throw new NoSuchContactException();
@@ -225,10 +238,11 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 			try {
 				Txn txn = db.startTransaction();
 				try {
-					subs = db.getSubscriptions(txn);
+					Set<GroupId> subs = db.getSubscriptions(txn);
 					if(LOG.isLoggable(Level.FINE))
 						LOG.fine("Added " + subs.size() + " subscriptions");
 					db.commitTransaction(txn);
+					return subs;
 				} catch(DbException e) {
 					db.abortTransaction(txn);
 					throw e;
@@ -239,7 +253,10 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 		} finally {
 			contactLock.readLock().unlock();
 		}
-		// Add transport details
+	}
+
+	private Map<String, String> generateTransports(ContactId c)
+	throws DbException {
 		contactLock.readLock().lock();
 		try {
 			if(!containsContact(c)) throw new NoSuchContactException();
@@ -247,10 +264,11 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 			try {
 				Txn txn = db.startTransaction();
 				try {
-					transports = db.getTransports(txn);
+					Map<String, String> transports = db.getTransports(txn);
 					if(LOG.isLoggable(Level.FINE))
 						LOG.fine("Added " + transports.size() + " transports");
 					db.commitTransaction(txn);
+					return transports;
 				} catch(DbException e) {
 					db.abortTransaction(txn);
 					throw e;
@@ -261,17 +279,10 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 		} finally {
 			contactLock.readLock().unlock();
 		}
-		// Add the header to the bundle
-		b.addHeader(acks, subs, transports);
-		// Add as many messages as possible to the bundle
-		while(fillBatch(c, b));
-		b.finish();
-		if(LOG.isLoggable(Level.FINE)) LOG.fine("Bundle generated");
-		System.gc();
 	}

-	private boolean fillBatch(ContactId c, BundleWriter b) throws DbException,
-	IOException, GeneralSecurityException {
+	private boolean generateBatch(ContactId c, BundleWriter b)
+	throws DbException, IOException, GeneralSecurityException {
 		contactLock.readLock().lock();
 		try {
 			if(!containsContact(c)) throw new NoSuchContactException();
@@ -309,7 +320,7 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 					} catch(IOException e) {
 						db.abortTransaction(txn);
 						throw e;
-					} catch(GeneralSecurityException e) {
+					} catch(SignatureException e) {
 						db.abortTransaction(txn);
 						throw e;
 					}
@@ -435,12 +446,29 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 	public void receiveBundle(ContactId c, BundleReader b) throws DbException,
 	IOException, GeneralSecurityException {
 		if(LOG.isLoggable(Level.FINE)) LOG.fine("Received bundle from " + c);
-		Header h;
+		Header h = b.getHeader();
+		receiveAcks(c, h);
+		receiveSubscriptions(c, h);
+		receiveTransports(c, h);
+		// Store the messages
+		int batches = 0;
+		Batch batch = null;
+		while((batch = b.getNextBatch()) != null) {
+			receiveBatch(c, batch);
+			batches++;
+		}
+		if(LOG.isLoggable(Level.FINE))
+			LOG.fine("Received " + batches + " batches");
+		b.finish();
+		findLostBatches(c);
+		System.gc();
+	}
+
+	private void receiveAcks(ContactId c, Header h) throws DbException {
 		// Mark all messages in acked batches as seen
 		contactLock.readLock().lock();
 		try {
 			if(!containsContact(c)) throw new NoSuchContactException();
-			h = b.getHeader();
 			messageLock.readLock().lock();
 			try {
 				messageStatusLock.writeLock().lock();
@@ -467,8 +495,12 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 		} finally {
 			contactLock.readLock().unlock();
 		}
+	}
+
+	private void receiveSubscriptions(ContactId c, Header h)
+	throws DbException {
 		// Update the contact's subscriptions
-		contactLock.readLock().lock();
+		contactLock.writeLock().lock();
 		try {
 			if(!containsContact(c)) throw new NoSuchContactException();
 			subscriptionLock.writeLock().lock();
@@ -476,7 +508,7 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 				Txn txn = db.startTransaction();
 				try {
 					Set<GroupId> subs = h.getSubscriptions();
-					db.setSubscriptions(txn, c, subs);
+					db.setSubscriptions(txn, c, subs, h.getTimestamp());
 					if(LOG.isLoggable(Level.FINE))
 						LOG.fine("Received " + subs.size() + " subscriptions");
 					db.commitTransaction(txn);
@@ -488,10 +520,13 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 				subscriptionLock.writeLock().unlock();
 			}
 		} finally {
-			contactLock.readLock().unlock();
+			contactLock.writeLock().unlock();
 		}
+	}
+
+	private void receiveTransports(ContactId c, Header h) throws DbException {
 		// Update the contact's transport details
-		contactLock.readLock().lock();
+		contactLock.writeLock().lock();
 		try {
 			if(!containsContact(c)) throw new NoSuchContactException();
 			transportLock.writeLock().lock();
@@ -499,7 +534,7 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 				Txn txn = db.startTransaction();
 				try {
 					Map<String, String> transports = h.getTransports();
-					db.setTransports(txn, c, transports);
+					db.setTransports(txn, c, transports, h.getTimestamp());
 					if(LOG.isLoggable(Level.FINE))
 						LOG.fine("Received " + transports.size()
 								+ " transports");
@@ -512,23 +547,11 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 				transportLock.writeLock().unlock();
 			}
 		} finally {
-			contactLock.readLock().unlock();
+			contactLock.writeLock().unlock();
 		}
-		// Store the messages
-		int batches = 0;
-		Batch batch = null;
-		while((batch = b.getNextBatch()) != null) {
-			storeBatch(c, batch);
-			batches++;
-		}
-		if(LOG.isLoggable(Level.FINE))
-			LOG.fine("Received " + batches + " batches");
-		b.finish();
-		findLostBatches(c);
-		System.gc();
 	}

-	private void storeBatch(ContactId c, Batch b) throws DbException {
+	private void receiveBatch(ContactId c, Batch b) throws DbException {
 		waitForPermissionToWrite();
 		contactLock.readLock().lock();
 		try {
@@ -687,29 +710,6 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 		}
 	}

-	public void setTransports(ContactId c, Map<String, String> transports)
-	throws DbException {
-		contactLock.readLock().lock();
-		try {
-			if(!containsContact(c)) throw new NoSuchContactException();
-			transportLock.writeLock().lock();
-			try {
-				Txn txn = db.startTransaction();
-				try {
-					db.setTransports(txn, c, transports);
-					db.commitTransaction(txn);
-				} catch(DbException e) {
-					db.abortTransaction(txn);
-					throw e;
-				}
-			} finally {
-				transportLock.writeLock().unlock();
-			}
-		} finally {
-			contactLock.readLock().unlock();
-		}
-	}
-
 	public void subscribe(GroupId g) throws DbException {
 		if(LOG.isLoggable(Level.FINE)) LOG.fine("Subscribing to " + g);
 		subscriptionLock.writeLock().lock();
--- a/components/net/sf/briar/db/SynchronizedDatabaseComponent.java
+++ b/components/net/sf/briar/db/SynchronizedDatabaseComponent.java
@@ -146,68 +146,78 @@ class SynchronizedDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 	public void generateBundle(ContactId c, BundleWriter b) throws DbException,
 	IOException, GeneralSecurityException {
 		if(LOG.isLoggable(Level.FINE)) LOG.fine("Generating bundle for " + c);
-		Set<BatchId> acks;
-		Set<GroupId> subs;
-		Map<String, String> transports;
-		// Add acks
-		synchronized(contactLock) {
-			if(!containsContact(c)) throw new NoSuchContactException();
-			synchronized(messageStatusLock) {
-				Txn txn = db.startTransaction();
-				try {
-					acks = db.removeBatchesToAck(txn, c);
-					if(LOG.isLoggable(Level.FINE))
-						LOG.fine("Added " + acks.size() + " acks");
-					db.commitTransaction(txn);
-				} catch(DbException e) {
-					db.abortTransaction(txn);
-					throw e;
-				}
-			}
-		}
-		// Add subscriptions
-		synchronized(contactLock) {
-			if(!containsContact(c)) throw new NoSuchContactException();
-			synchronized(subscriptionLock) {
-				Txn txn = db.startTransaction();
-				try {
-					subs = db.getSubscriptions(txn);
-					if(LOG.isLoggable(Level.FINE))
-						LOG.fine("Added " + subs.size() + " subscriptions");
-					db.commitTransaction(txn);
-				} catch(DbException e) {
-					db.abortTransaction(txn);
-					throw e;
-				}
-			}
-		}
-		// Add transport details
-		synchronized(contactLock) {
-			if(!containsContact(c)) throw new NoSuchContactException();
-			synchronized(transportLock) {
-				Txn txn = db.startTransaction();
-				try {
-					transports = db.getTransports(txn);
-					if(LOG.isLoggable(Level.FINE))
-						LOG.fine("Added " + transports.size() + " transports");
-					db.commitTransaction(txn);
-				} catch(DbException e) {
-					db.abortTransaction(txn);
-					throw e;
-				}
-			}
-		}
+		Set<BatchId> acks = generateAcks(c);
+		Set<GroupId> subs = generateSubscriptions(c);
+		Map<String, String> transports = generateTransports(c);
 		// Add the header to the bundle
 		b.addHeader(acks, subs, transports);
 		// Add as many messages as possible to the bundle
-		while(fillBatch(c, b));
+		while(generateBatch(c, b));
 		b.finish();
 		if(LOG.isLoggable(Level.FINE)) LOG.fine("Bundle generated");
 		System.gc();
 	}

-	private boolean fillBatch(ContactId c, BundleWriter b) throws DbException,
-	IOException, GeneralSecurityException {
+	private Set<BatchId> generateAcks(ContactId c) throws DbException {
+		synchronized(contactLock) {
+			if(!containsContact(c)) throw new NoSuchContactException();
+			synchronized(messageStatusLock) {
+				Txn txn = db.startTransaction();
+				try {
+					Set<BatchId> acks = db.removeBatchesToAck(txn, c);
+					if(LOG.isLoggable(Level.FINE))
+						LOG.fine("Added " + acks.size() + " acks");
+					db.commitTransaction(txn);
+					return acks;
+				} catch(DbException e) {
+					db.abortTransaction(txn);
+					throw e;
+				}
+			}
+		}
+	}
+
+	private Set<GroupId> generateSubscriptions(ContactId c) throws DbException {
+		synchronized(contactLock) {
+			if(!containsContact(c)) throw new NoSuchContactException();
+			synchronized(subscriptionLock) {
+				Txn txn = db.startTransaction();
+				try {
+					Set<GroupId> subs = db.getSubscriptions(txn);
+					if(LOG.isLoggable(Level.FINE))
+						LOG.fine("Added " + subs.size() + " subscriptions");
+					db.commitTransaction(txn);
+					return subs;
+				} catch(DbException e) {
+					db.abortTransaction(txn);
+					throw e;
+				}
+			}
+		}
+	}
+
+	private Map<String, String> generateTransports(ContactId c)
+	throws DbException {
+		synchronized(contactLock) {
+			if(!containsContact(c)) throw new NoSuchContactException();
+			synchronized(transportLock) {
+				Txn txn = db.startTransaction();
+				try {
+					Map<String, String> transports = db.getTransports(txn);
+					if(LOG.isLoggable(Level.FINE))
+						LOG.fine("Added " + transports.size() + " transports");
+					db.commitTransaction(txn);
+					return transports;
+				} catch(DbException e) {
+					db.abortTransaction(txn);
+					throw e;
+				}
+			}
+		}
+	}
+
+	private boolean generateBatch(ContactId c, BundleWriter b)
+	throws DbException, IOException, GeneralSecurityException {
 		synchronized(contactLock) {
 			if(!containsContact(c)) throw new NoSuchContactException();
 			synchronized(messageLock) {
@@ -242,6 +252,9 @@ class SynchronizedDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 					} catch(DbException e) {
 						db.abortTransaction(txn);
 						throw e;
+					} catch(IOException e) {
+						db.abortTransaction(txn);
+						throw e;
 					} catch(SignatureException e) {
 						db.abortTransaction(txn);
 						throw e;
@@ -327,11 +340,28 @@ class SynchronizedDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 	public void receiveBundle(ContactId c, BundleReader b) throws DbException,
 	IOException, GeneralSecurityException {
 		if(LOG.isLoggable(Level.FINE)) LOG.fine("Received bundle from " + c);
-		Header h;
+		Header h = b.getHeader();
+		receiveAcks(c, h);
+		receiveSubscriptions(c, h);
+		receiveTransports(c, h);
+		// Store the messages
+		int batches = 0;
+		Batch batch = null;
+		while((batch = b.getNextBatch()) != null) {
+			receiveBatch(c, batch);
+			batches++;
+		}
+		if(LOG.isLoggable(Level.FINE))
+			LOG.fine("Received " + batches + " batches");
+		b.finish();
+		findLostBatches(c);
+		System.gc();
+	}
+
+	private void receiveAcks(ContactId c, Header h) throws DbException {
 		// Mark all messages in acked batches as seen
 		synchronized(contactLock) {
 			if(!containsContact(c)) throw new NoSuchContactException();
-			h = b.getHeader();
 			synchronized(messageLock) {
 				synchronized(messageStatusLock) {
 					Set<BatchId> acks = h.getAcks();
@@ -350,6 +380,10 @@ class SynchronizedDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 				}
 			}
 		}
+	}
+
+	private void receiveSubscriptions(ContactId c, Header h)
+	throws DbException {
 		// Update the contact's subscriptions
 		synchronized(contactLock) {
 			if(!containsContact(c)) throw new NoSuchContactException();
@@ -357,7 +391,7 @@ class SynchronizedDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 				Txn txn = db.startTransaction();
 				try {
 					Set<GroupId> subs = h.getSubscriptions();
-					db.setSubscriptions(txn, c, subs);
+					db.setSubscriptions(txn, c, subs, h.getTimestamp());
 					if(LOG.isLoggable(Level.FINE))
 						LOG.fine("Received " + subs.size() + " subscriptions");
 					db.commitTransaction(txn);
@@ -367,6 +401,9 @@ class SynchronizedDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 				}
 			}
 		}
+	}
+
+	private void receiveTransports(ContactId c, Header h) throws DbException {
 		// Update the contact's transport details
 		synchronized(contactLock) {
 			if(!containsContact(c)) throw new NoSuchContactException();
@@ -374,7 +411,7 @@ class SynchronizedDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 				Txn txn = db.startTransaction();
 				try {
 					Map<String, String> transports = h.getTransports();
-					db.setTransports(txn, c, transports);
+					db.setTransports(txn, c, transports, h.getTimestamp());
 					if(LOG.isLoggable(Level.FINE))
 						LOG.fine("Received " + transports.size()
 								+ " transports");
@@ -385,21 +422,9 @@ class SynchronizedDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 				}
 			}
 		}
-		// Store the messages
-		int batches = 0;
-		Batch batch = null;
-		while((batch = b.getNextBatch()) != null) {
-			storeBatch(c, batch);
-			batches++;
-		}
-		if(LOG.isLoggable(Level.FINE))
-			LOG.fine("Received " + batches + " batches");
-		b.finish();
-		findLostBatches(c);
-		System.gc();
 	}

-	private void storeBatch(ContactId c, Batch b) throws DbException {
+	private void receiveBatch(ContactId c, Batch b) throws DbException {
 		waitForPermissionToWrite();
 		synchronized(contactLock) {
 			if(!containsContact(c)) throw new NoSuchContactException();
@@ -511,23 +536,6 @@ class SynchronizedDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 		}
 	}

-	public void setTransports(ContactId c, Map<String, String> transports)
-	throws DbException {
-		synchronized(contactLock) {
-			if(!containsContact(c)) throw new NoSuchContactException();
-			synchronized(transportLock) {
-				Txn txn = db.startTransaction();
-				try {
-					db.setTransports(txn, c, transports);
-					db.commitTransaction(txn);
-				} catch(DbException e) {
-					db.abortTransaction(txn);
-					throw e;
-				}
-			}
-		}
-	}
-
 	public void subscribe(GroupId g) throws DbException {
 		if(LOG.isLoggable(Level.FINE)) LOG.fine("Subscribing to " + g);
 		synchronized(subscriptionLock) {
--- a/components/net/sf/briar/invitation/InvitationModule.java
+++ b/components/net/sf/briar/invitation/InvitationModule.java
@@ -8,6 +8,7 @@ public class InvitationModule extends AbstractModule {

 	@Override
 	protected void configure() {
-		bind(InvitationWorkerFactory.class).to(InvitationWorkerFactoryImpl.class);
+		bind(InvitationWorkerFactory.class).to(
+				InvitationWorkerFactoryImpl.class);
 	}
 }