Split transport identifiers into two: TransportId (globally unique)

and TransportIndex (locally unique).

This is the first step towards forward secrecy. Also removed the
Writable interface and unnecessary user-defined types, moved various
constants to ProtocolConstants and renamed some classes.

api/net/sf/briar/api/ContactId.java

@@ -1,6 +1,9 @@
 package net.sf.briar.api;
 
-/** Type-safe wrapper for an integer that uniquely identifies a contact. */
+/**
+ * Type-safe wrapper for an integer that uniquely identifies a contact within
+ * the scope of a single node.
+ */
 public class ContactId {
 
 	private final int id;
@@ -23,9 +26,4 @@ public class ContactId {
 	public int hashCode() {
 		return id;
 	}
-
-	@Override
-	public String toString() {
-		return String.valueOf(id);
-	}
 }

api/net/sf/briar/api/TransportId.java

@@ -1,41 +0,0 @@
-package net.sf.briar.api;
-
-import java.io.IOException;
-
-import net.sf.briar.api.serial.Writable;
-import net.sf.briar.api.serial.Writer;
-
-/**
- * Type-safe wrapper for an integer that uniquely identifies a transport plugin.
- */
-public class TransportId implements Writable {
-
-	public static final int MIN_ID = 0;
-	public static final int MAX_ID = 65535;
-
-	private final int id;
-
-	public TransportId(int id) {
-		if(id < MIN_ID || id > MAX_ID) throw new IllegalArgumentException();
-		this.id = id;
-	}
-
-	public int getInt() {
-		return id;
-	}
-
-	public void writeTo(Writer w) throws IOException {
-		w.writeInt32(id);
-	}
-
-	@Override
-	public boolean equals(Object o) {
-		if(o instanceof TransportId) return id == ((TransportId) o).id;
-		return false;
-	}
-
-	@Override
-	public int hashCode() {
-		return id;
-	}
-}

api/net/sf/briar/api/db/DatabaseComponent.java

@@ -7,7 +7,6 @@ import java.util.Map;
 import net.sf.briar.api.ContactId;
 import net.sf.briar.api.Rating;
 import net.sf.briar.api.TransportConfig;
-import net.sf.briar.api.TransportId;
 import net.sf.briar.api.TransportProperties;
 import net.sf.briar.api.db.event.DatabaseListener;
 import net.sf.briar.api.protocol.Ack;
@@ -19,6 +18,9 @@ import net.sf.briar.api.protocol.Message;
 import net.sf.briar.api.protocol.MessageId;
 import net.sf.briar.api.protocol.Offer;
 import net.sf.briar.api.protocol.SubscriptionUpdate;
+import net.sf.briar.api.protocol.Transport;
+import net.sf.briar.api.protocol.TransportId;
+import net.sf.briar.api.protocol.TransportIndex;
 import net.sf.briar.api.protocol.TransportUpdate;
 import net.sf.briar.api.protocol.writers.AckWriter;
 import net.sf.briar.api.protocol.writers.BatchWriter;
@@ -51,11 +53,10 @@ public interface DatabaseComponent {
 	void removeListener(DatabaseListener d);
 
 	/**
-	 * Adds a new contact to the database with the given transport properties
-	 * and shared secret, returns an ID for the contact.
+	 * Adds a new contact to the database with the given secret and returns an
+	 * ID for the contact.
 	 */
-	ContactId addContact(Map<TransportId, TransportProperties> transports,
-			byte[] secret) throws DbException;
+	ContactId addContact(byte[] secret) throws DbException;
 
 	/** Adds a locally generated group message to the database. */
 	void addLocalGroupMessage(Message m) throws DbException;
@@ -63,6 +64,12 @@ public interface DatabaseComponent {
 	/** Adds a locally generated private message to the database. */
 	void addLocalPrivateMessage(Message m, ContactId c) throws DbException;
 
+	/**
+	 * Allocates and returns a local index for the given transport. Returns
+	 * null if all indices have been allocated.
+	 */
+	TransportIndex addTransport(TransportId t) throws DbException;
+
 	/**
 	 * Generates an acknowledgement for the given contact.
 	 * @return True if any batch IDs were added to the acknowledgement.
@@ -109,24 +116,29 @@ public interface DatabaseComponent {
 	 * Returns an outgoing connection number for the given contact and
 	 * transport.
 	 */
-	long getConnectionNumber(ContactId c, TransportId t) throws DbException;
+	long getConnectionNumber(ContactId c, TransportIndex i) throws DbException;
 
 	/**
 	 * Returns the connection reordering window for the given contact and
 	 * transport.
 	 */
-	ConnectionWindow getConnectionWindow(ContactId c, TransportId t)
+	ConnectionWindow getConnectionWindow(ContactId c, TransportIndex i)
 	throws DbException;
 
 	/** Returns the IDs of all contacts. */
 	Collection<ContactId> getContacts() throws DbException;
 
+	/**
+	 * Returns the local index for the given transport, or null if no index
+	 * has been allocated.
+	 */
+	TransportIndex getLocalIndex(TransportId t) throws DbException;
+
 	/** Returns the local transport properties for the given transport. */
 	TransportProperties getLocalProperties(TransportId t) throws DbException;
 
-	/** Returns all local transport properties. */
-	Map<TransportId, TransportProperties> getLocalTransports()
-	throws DbException;
+	/** Returns all local transports. */
+	Collection<Transport> getLocalTransports() throws DbException;
 
 	/** Returns the headers of all messages in the given group. */
 	Collection<MessageHeader> getMessageHeaders(GroupId g) throws DbException;
@@ -134,6 +146,13 @@ public interface DatabaseComponent {
 	/** Returns the user's rating for the given author. */
 	Rating getRating(AuthorId a) throws DbException;
 
+	/**
+	 * Returns the given contact's index for the given transport, or null if
+	 * the contact does not support the transport.
+	 */
+	TransportIndex getRemoteIndex(ContactId c, TransportId t)
+	throws DbException;
+
 	/** Returns all remote transport properties for the given transport. */
 	Map<ContactId, TransportProperties> getRemoteProperties(TransportId t)
 	throws DbException;
@@ -191,8 +210,8 @@ public interface DatabaseComponent {
 	 * Sets the connection reordering window for the given contact and
 	 * transport.
 	 */
-	void setConnectionWindow(ContactId c, TransportId t, ConnectionWindow w)
-	throws DbException;
+	void setConnectionWindow(ContactId c, TransportIndex i,
+			ConnectionWindow w) throws DbException;
 
 	/**
 	 * Sets the local transport properties for the given transport, replacing

api/net/sf/briar/api/db/event/ContactRemovedEvent.java

@@ -3,9 +3,15 @@ package net.sf.briar.api.db.event;
 import net.sf.briar.api.ContactId;
 
 /** An event that is broadcast when a contact is removed. */
-public class ContactRemovedEvent extends ContactAddedEvent {
+public class ContactRemovedEvent extends DatabaseEvent {
+
+	private final ContactId contactId;
 
 	public ContactRemovedEvent(ContactId contactId) {
-		super(contactId);
+		this.contactId = contactId;
+	}
+
+	public ContactId getContactId() {
+		return contactId;
 	}
 }

api/net/sf/briar/api/db/event/LocalTransportsUpdatedEvent.java

@@ -0,0 +1,9 @@
+package net.sf.briar.api.db.event;
+
+/**
+ * An event that is broadcast when the local transport properties are
+ * updated.
+ */
+public class LocalTransportsUpdatedEvent extends DatabaseEvent {
+
+}

api/net/sf/briar/api/db/event/RemoteTransportsUpdatedEvent.java

@@ -0,0 +1,17 @@
+package net.sf.briar.api.db.event;
+
+import net.sf.briar.api.ContactId;
+
+/** An event that is broadcast when a contact's transports are updated. */
+public class RemoteTransportsUpdatedEvent extends DatabaseEvent {
+
+	private final ContactId contactId;
+
+	public RemoteTransportsUpdatedEvent(ContactId contactId) {
+		this.contactId = contactId;
+	}
+
+	public ContactId getContactId() {
+		return contactId;
+	}
+}

api/net/sf/briar/api/db/event/TransportAddedEvent.java

@@ -0,0 +1,17 @@
+package net.sf.briar.api.db.event;
+
+import net.sf.briar.api.protocol.TransportId;
+
+/** An event that is broadcast when a transport is added. */
+public class TransportAddedEvent extends DatabaseEvent {
+
+	private final TransportId transportId;
+
+	public TransportAddedEvent(TransportId transportId) {
+		this.transportId = transportId;
+	}
+
+	public TransportId getTransportId() {
+		return transportId;
+	}
+}

api/net/sf/briar/api/db/event/TransportsUpdatedEvent.java

@@ -1,6 +0,0 @@
-package net.sf.briar.api.db.event;
-
-/** An event that is broadcast when the local transports are updated. */
-public class TransportsUpdatedEvent extends DatabaseEvent {
-
-}

api/net/sf/briar/api/plugins/BatchPluginFactory.java

@@ -4,6 +4,5 @@ import java.util.concurrent.Executor;
 
 public interface BatchPluginFactory {
 
-	BatchPlugin createPlugin(Executor executor,
-			BatchPluginCallback callback);
+	BatchPlugin createPlugin(Executor executor, BatchPluginCallback callback);
 }

api/net/sf/briar/api/plugins/Plugin.java

@@ -2,7 +2,7 @@ package net.sf.briar.api.plugins;
 
 import java.io.IOException;
 
-import net.sf.briar.api.TransportId;
+import net.sf.briar.api.protocol.TransportId;
 
 public interface Plugin {
 

api/net/sf/briar/api/plugins/PluginManager.java

@@ -3,14 +3,13 @@ package net.sf.briar.api.plugins;
 public interface PluginManager {
 
 	/**
-	 * Starts all the plugins the manager knows about and returns the number of
-	 * plugins successfully started.
+	 * Starts the plugins and returns the number of plugins successfully
+	 * started.
 	 */
 	int startPlugins();
 
 	/**
-	 * Stops all the plugins started by startPlugins() and returns the number
-	 * of plugins successfully stopped.
+	 * Stops the plugins and returns the number of plugins successfully stopped.
 	 */
 	int stopPlugins();
 }

api/net/sf/briar/api/plugins/StreamPluginFactory.java

@@ -4,6 +4,5 @@ import java.util.concurrent.Executor;
 
 public interface StreamPluginFactory {
 
-	StreamPlugin createPlugin(Executor executor,
-			StreamPluginCallback callback);
+	StreamPlugin createPlugin(Executor executor, StreamPluginCallback callback);
 }

api/net/sf/briar/api/protocol/Author.java

@@ -1,15 +1,7 @@
 package net.sf.briar.api.protocol;
 
-import net.sf.briar.api.serial.Writable;
-
 /** A pseudonymous author of messages. */
-public interface Author extends Writable {
-
-	/** The maximum length of an author's name in UTF-8 bytes. */
-	static final int MAX_NAME_LENGTH = 50;
-
-	/** The maximum length of an author's public key in bytes. */
-	static final int MAX_PUBLIC_KEY_LENGTH = 100;
+public interface Author {
 
 	/** Returns the author's unique identifier. */
 	AuthorId getId();

api/net/sf/briar/api/protocol/AuthorId.java

@@ -1,10 +1,7 @@
 package net.sf.briar.api.protocol;
 
-import java.io.IOException;
 import java.util.Arrays;
 
-import net.sf.briar.api.serial.Writer;
-
 /** Type-safe wrapper for a byte array that uniquely identifies an author. */
 public class AuthorId extends UniqueId {
 
@@ -12,11 +9,6 @@ public class AuthorId extends UniqueId {
 		super(id);
 	}
 
-	public void writeTo(Writer w) throws IOException {
-		w.writeUserDefinedId(Types.AUTHOR_ID);
-		w.writeBytes(id);
-	}
-
 	@Override
 	public boolean equals(Object o) {
 		if(o instanceof AuthorId)

api/net/sf/briar/api/protocol/BatchId.java

@@ -1,10 +1,7 @@
 package net.sf.briar.api.protocol;
 
-import java.io.IOException;
 import java.util.Arrays;
 
-import net.sf.briar.api.serial.Writer;
-
 /**
  * Type-safe wrapper for a byte array that uniquely identifies a batch of
  * messages.
@@ -15,11 +12,6 @@ public class BatchId extends UniqueId {
 		super(id);
 	}
 
-	public void writeTo(Writer w) throws IOException {
-		w.writeUserDefinedId(Types.BATCH_ID);
-		w.writeBytes(id);
-	}
-
 	@Override
 	public boolean equals(Object o) {
 		if(o instanceof BatchId)

api/net/sf/briar/api/protocol/Group.java

@@ -1,15 +1,7 @@
 package net.sf.briar.api.protocol;
 
-import net.sf.briar.api.serial.Writable;
-
 /** A group to which users may subscribe. */
-public interface Group extends Writable {
-
-	/** The maximum length of a group's name in UTF-8 bytes. */
-	static final int MAX_NAME_LENGTH = 50;
-
-	/** The maximum length of a group's public key in bytes. */
-	static final int MAX_PUBLIC_KEY_LENGTH = 100;
+public interface Group {
 
 	/** Returns the group's unique identifier. */
 	GroupId getId();

api/net/sf/briar/api/protocol/GroupId.java

@@ -1,10 +1,7 @@
 package net.sf.briar.api.protocol;
 
-import java.io.IOException;
 import java.util.Arrays;
 
-import net.sf.briar.api.serial.Writer;
-
 /**
  * Type-safe wrapper for a byte array that uniquely identifies a group to which
  * users may subscribe.
@@ -15,11 +12,6 @@ public class GroupId extends UniqueId {
 		super(id);
 	}
 
-	public void writeTo(Writer w) throws IOException {
-		w.writeUserDefinedId(Types.GROUP_ID);
-		w.writeBytes(id);
-	}
-
 	@Override
 	public boolean equals(Object o) {
 		if(o instanceof GroupId)

api/net/sf/briar/api/protocol/Message.java

@@ -2,23 +2,6 @@ package net.sf.briar.api.protocol;
 
 public interface Message {
 
-	/**
-	 * The maximum length of a message body in bytes. To allow for future
-	 * changes in the protocol, this is smaller than the maximum packet length
-	 * even when all the message's other fields have their maximum lengths.
-	 */
-	static final int MAX_BODY_LENGTH =
-		ProtocolConstants.MAX_PACKET_LENGTH - 1024;
-
-	/** The maximum length of a subject line in UTF-8 bytes. */
-	static final int MAX_SUBJECT_LENGTH = 100;
-
-	/** The maximum length of a signature in bytes. */
-	static final int MAX_SIGNATURE_LENGTH = 100;
-
-	/** The length of the random salt in bytes. */
-	static final int SALT_LENGTH = 8;
-
 	/** Returns the message's unique identifier. */
 	MessageId getId();
 

api/net/sf/briar/api/protocol/MessageId.java

@@ -1,10 +1,7 @@
 package net.sf.briar.api.protocol;
 
-import java.io.IOException;
 import java.util.Arrays;
 
-import net.sf.briar.api.serial.Writer;
-
 /** Type-safe wrapper for a byte array that uniquely identifies a message. */
 public class MessageId extends UniqueId {
 
@@ -12,11 +9,6 @@ public class MessageId extends UniqueId {
 		super(id);
 	}
 
-	public void writeTo(Writer w) throws IOException {
-		w.writeUserDefinedId(Types.MESSAGE_ID);
-		w.writeBytes(id);
-	}
-
 	@Override
 	public boolean equals(Object o) {
 		if(o instanceof MessageId)

api/net/sf/briar/api/protocol/ProtocolConstants.java

@@ -11,4 +11,41 @@ public interface ProtocolConstants {
 	 */
 	static final int MAX_PACKET_LENGTH =
 		TransportConstants.MIN_CONNECTION_LENGTH - 1024;
+
+	/** The maximum number of transport plugins a node may support. */
+	static final int MAX_TRANSPORTS = 50;
+
+	/** The maximum number of properties per transport plugin. */
+	static final int MAX_PROPERTIES_PER_TRANSPORT = 100;
+
+	/** The maximum length of a property's key or value in UTF-8 bytes. */
+	static final int MAX_PROPERTY_LENGTH = 100;
+
+	/** The maximum number of groups a node may subscribe to. */
+	static final int MAX_GROUPS = 6000;
+
+	/** The maximum length of a group's name in UTF-8 bytes. */
+	static final int MAX_GROUP_NAME_LENGTH = 50;
+
+	/** The maximum length of a serialised public key in bytes. */
+	static final int MAX_PUBLIC_KEY_LENGTH = 100;
+
+	/** The maximum length of an author's name in UTF-8 bytes. */
+	static final int MAX_AUTHOR_NAME_LENGTH = 50;
+
+	/**
+	 * The maximum length of a message body in bytes. To allow for future
+	 * changes in the protocol, this is smaller than the maximum packet length
+	 * even when all the message's other fields have their maximum lengths.
+	 */
+	static final int MAX_BODY_LENGTH = MAX_PACKET_LENGTH - 1024;
+
+	/** The maximum length of a message's subject line in UTF-8 bytes. */
+	static final int MAX_SUBJECT_LENGTH = 100;
+
+	/** The maximum length of a signature in bytes. */
+	static final int MAX_SIGNATURE_LENGTH = 100;
+
+	/** The length of a message's random salt in bytes. */
+	static final int SALT_LENGTH = 8;
 }

api/net/sf/briar/api/protocol/SubscriptionUpdate.java

@@ -5,9 +5,6 @@ import java.util.Map;
 /** A packet updating the sender's subscriptions. */
 public interface SubscriptionUpdate {
 
-	/** The maximum number of subscriptions per update. */
-	static final int MAX_SUBS_PER_UPDATE = 6000;
-
 	/** Returns the subscriptions contained in the update. */
 	Map<Group, Long> getSubscriptions();
 

api/net/sf/briar/api/protocol/Transport.java

@@ -0,0 +1,47 @@
+package net.sf.briar.api.protocol;
+
+import java.util.Map;
+import java.util.TreeMap;
+
+public class Transport extends TreeMap<String, String> {
+
+	private static final long serialVersionUID = 4900420175715429560L;
+
+	private final TransportId id;
+	private final TransportIndex index;
+
+	public Transport(TransportId id, TransportIndex index,
+			Map<String, String> p) {
+		super(p);
+		this.id = id;
+		this.index = index;
+	}
+
+	public Transport(TransportId id, TransportIndex index) {
+		super();
+		this.id = id;
+		this.index = index;
+	}
+
+	public TransportId getId() {
+		return id;
+	}
+
+	public TransportIndex getIndex() {
+		return index;
+	}
+
+	@Override
+	public int hashCode() {
+		return id.hashCode();
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if(o instanceof Transport) {
+			Transport t = (Transport) o;
+			return id.equals(t.id) && index.equals(t.index) && super.equals(o);
+		}
+		return false;
+	}
+}

api/net/sf/briar/api/protocol/TransportId.java

@@ -0,0 +1,21 @@
+package net.sf.briar.api.protocol;
+
+import java.util.Arrays;
+
+/**
+ * Type-safe wrapper for a byte array that uniquely identifies a transport
+ * plugin.
+ */
+public class TransportId extends UniqueId {
+
+	public TransportId(byte[] id) {
+		super(id);
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if(o instanceof TransportId)
+			return Arrays.equals(id, ((TransportId) o).id);
+		return false;
+	}
+}

api/net/sf/briar/api/protocol/TransportIndex.java

@@ -0,0 +1,33 @@
+package net.sf.briar.api.protocol;
+
+
+/**
+ * Type-safe wrapper for an integer that uniquely identifies a transport plugin
+ * within the scope of a single node.
+ */
+public class TransportIndex {
+
+	private final int index;
+
+	public TransportIndex(int index) {
+		if(index < 0 || index >= ProtocolConstants.MAX_TRANSPORTS)
+			throw new IllegalArgumentException();
+		this.index = index;
+	}
+
+	public int getInt() {
+		return index;
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if(o instanceof TransportIndex)
+			return index == ((TransportIndex) o).index;
+		return false;
+	}
+
+	@Override
+	public int hashCode() {
+		return index;
+	}
+}

api/net/sf/briar/api/protocol/TransportUpdate.java

@@ -1,24 +1,12 @@
 package net.sf.briar.api.protocol;
 
-import java.util.Map;
-
-import net.sf.briar.api.TransportId;
-import net.sf.briar.api.TransportProperties;
+import java.util.Collection;
 
 /** A packet updating the sender's transport properties. */
 public interface TransportUpdate {
 
-	/** The maximum length of a property's key or value in UTF-8 bytes. */
-	static final int MAX_KEY_OR_VALUE_LENGTH = 100;
-
-	/** The maximum number of properties per plugin. */
-	static final int MAX_PROPERTIES_PER_PLUGIN = 100;
-
-	/** The maximum number of plugins per update. */
-	static final int MAX_PLUGINS_PER_UPDATE = 50;
-
-	/** Returns the transport properties contained in the update. */
-	Map<TransportId, TransportProperties> getTransports();
+	/** Returns the transports contained in the update. */
+	Collection<Transport> getTransports();
 
 	/**
 	 * Returns the update's timestamp. Updates that are older than the newest

api/net/sf/briar/api/protocol/Types.java

@@ -5,16 +5,14 @@ public interface Types {
 
 	static final int ACK = 0;
 	static final int AUTHOR = 1;
-	static final int AUTHOR_ID = 2;
-	static final int BATCH = 3;
-	static final int BATCH_ID = 4;
-	static final int GROUP = 5;
-	static final int GROUP_ID = 6;
-	static final int MESSAGE = 7;
-	static final int MESSAGE_ID = 8;
-	static final int OFFER = 9;
-	static final int REQUEST = 10;
-	static final int SUBSCRIPTION_UPDATE = 11;
-	static final int TRANSPORT_PROPERTIES = 12;
-	static final int TRANSPORT_UPDATE = 13;
+	static final int BATCH = 2;
+	static final int BATCH_ID = 3;
+	static final int GROUP = 4;
+	static final int MESSAGE = 5;
+	static final int MESSAGE_ID = 6;
+	static final int OFFER = 7;
+	static final int REQUEST = 8;
+	static final int SUBSCRIPTION_UPDATE = 9;
+	static final int TRANSPORT = 10;
+	static final int TRANSPORT_UPDATE = 11;
 }

api/net/sf/briar/api/protocol/UniqueId.java

@@ -2,9 +2,7 @@ package net.sf.briar.api.protocol;
 
 import java.util.Arrays;
 
-import net.sf.briar.api.serial.Writable;
-
-public abstract class UniqueId implements Writable {
+public abstract class UniqueId {
 
 	/** The length of a unique identifier in bytes. */
 	public static final int LENGTH = 32;

api/net/sf/briar/api/protocol/writers/AuthorWriter.java

@@ -0,0 +1,11 @@
+package net.sf.briar.api.protocol.writers;
+
+import java.io.IOException;
+
+import net.sf.briar.api.protocol.Author;
+import net.sf.briar.api.serial.Writer;
+
+public interface AuthorWriter {
+
+	void writeAuthor(Writer w, Author a) throws IOException;
+}

api/net/sf/briar/api/protocol/writers/GroupWriter.java

@@ -0,0 +1,11 @@
+package net.sf.briar.api.protocol.writers;
+
+import java.io.IOException;
+
+import net.sf.briar.api.protocol.Group;
+import net.sf.briar.api.serial.Writer;
+
+public interface GroupWriter {
+
+	void writeGroup(Writer w, Group g) throws IOException;
+}

api/net/sf/briar/api/protocol/writers/MessageEncoder.java

@@ -1,9 +1,14 @@
-package net.sf.briar.api.protocol;
+package net.sf.briar.api.protocol.writers;
 
 import java.io.IOException;
 import java.security.GeneralSecurityException;
 import java.security.PrivateKey;
 
+import net.sf.briar.api.protocol.Author;
+import net.sf.briar.api.protocol.Group;
+import net.sf.briar.api.protocol.Message;
+import net.sf.briar.api.protocol.MessageId;
+
 public interface MessageEncoder {
 
 	/** Encodes a private message. */

api/net/sf/briar/api/protocol/writers/TransportWriter.java

@@ -1,15 +1,14 @@
 package net.sf.briar.api.protocol.writers;
 
 import java.io.IOException;
-import java.util.Map;
+import java.util.Collection;
 
-import net.sf.briar.api.TransportId;
-import net.sf.briar.api.TransportProperties;
+import net.sf.briar.api.protocol.Transport;
 
 /** An interface for creating a transport update. */
 public interface TransportWriter {
 
 	/** Writes the contents of the update. */
-	void writeTransports(Map<TransportId, TransportProperties> transports,
-			long timestamp) throws IOException;
+	void writeTransports(Collection<Transport> transports, long timestamp)
+	throws IOException;
 }

api/net/sf/briar/api/serial/Writable.java

@@ -1,8 +0,0 @@
-package net.sf.briar.api.serial;
-
-import java.io.IOException;
-
-public interface Writable {
-
-	void writeTo(Writer w) throws IOException;
-}

api/net/sf/briar/api/transport/BatchConnectionFactory.java

@@ -1,13 +1,13 @@
 package net.sf.briar.api.transport;
 
 import net.sf.briar.api.ContactId;
-import net.sf.briar.api.TransportId;
+import net.sf.briar.api.protocol.TransportIndex;
 
 public interface BatchConnectionFactory {
 
-	void createIncomingConnection(TransportId t, ContactId c,
+	void createIncomingConnection(TransportIndex i, ContactId c,
 			BatchTransportReader r, byte[] encryptedIv);
 
-	void createOutgoingConnection(TransportId t, ContactId c,
+	void createOutgoingConnection(TransportIndex i, ContactId c,
 			BatchTransportWriter w);
 }

api/net/sf/briar/api/transport/ConnectionContext.java

@@ -0,0 +1,16 @@
+package net.sf.briar.api.transport;
+
+import net.sf.briar.api.ContactId;
+import net.sf.briar.api.protocol.TransportId;
+import net.sf.briar.api.protocol.TransportIndex;
+
+public interface ConnectionContext {
+
+	ContactId getContactId();
+
+	TransportId getTransportId();
+
+	TransportIndex getTransportIndex();
+
+	long getConnectionNumber();
+}

api/net/sf/briar/api/transport/ConnectionDispatcher.java

@@ -1,17 +1,17 @@
 package net.sf.briar.api.transport;
 
 import net.sf.briar.api.ContactId;
-import net.sf.briar.api.TransportId;
+import net.sf.briar.api.protocol.TransportId;
+import net.sf.briar.api.protocol.TransportIndex;
 
 public interface ConnectionDispatcher {
 
 	void dispatchReader(TransportId t, BatchTransportReader r);
 
-	void dispatchWriter(TransportId t, ContactId c,
-			BatchTransportWriter w);
+	void dispatchWriter(TransportIndex i, ContactId c, BatchTransportWriter w);
 
 	void dispatchIncomingConnection(TransportId t, StreamTransportConnection s);
 
-	void dispatchOutgoingConnection(TransportId t, ContactId c,
+	void dispatchOutgoingConnection(TransportIndex i, ContactId c,
 			StreamTransportConnection s);
 }

api/net/sf/briar/api/transport/ConnectionReaderFactory.java

@@ -2,7 +2,7 @@ package net.sf.briar.api.transport;
 
 import java.io.InputStream;
 
-import net.sf.briar.api.TransportId;
+import net.sf.briar.api.protocol.TransportIndex;
 
 public interface ConnectionReaderFactory {
 
@@ -10,13 +10,13 @@ public interface ConnectionReaderFactory {
 	 * Creates a connection reader for a batch-mode connection or the
 	 * initiator's side of a stream-mode connection.
 	 */
-	ConnectionReader createConnectionReader(InputStream in, TransportId t,
+	ConnectionReader createConnectionReader(InputStream in, TransportIndex i,
 			byte[] encryptedIv, byte[] secret);
 
 	/**
 	 * Creates a connection reader for the responder's side of a stream-mode
 	 * connection.
 	 */
-	ConnectionReader createConnectionReader(InputStream in, TransportId t,
+	ConnectionReader createConnectionReader(InputStream in, TransportIndex i,
 			long connection, byte[] secret);
 }

api/net/sf/briar/api/transport/ConnectionRecogniser.java

@@ -1,18 +1,16 @@
 package net.sf.briar.api.transport;
 
-import net.sf.briar.api.ContactId;
 import net.sf.briar.api.db.DbException;
 
 /**
- * Maintains a transport plugin's connection reordering window and decides
- * whether incoming connections should be accepted or rejected.
+ * Maintains the connection reordering windows and decides whether incoming
+ * connections should be accepted or rejected.
  */
 public interface ConnectionRecogniser {
 
 	/**
-	 * Returns the ID of the contact who created the encrypted IV if the
-	 * connection should be accepted, or null if the connection should be
-	 * rejected.
+	 * Returns the connection's context if the connection should be accepted,
+	 * or null if the connection should be rejected.
 	 */
-	ContactId acceptConnection(byte[] encryptedIv) throws DbException;
+	ConnectionContext acceptConnection(byte[] encryptedIv) throws DbException;
 }

api/net/sf/briar/api/transport/ConnectionRecogniserFactory.java

@@ -1,8 +0,0 @@
-package net.sf.briar.api.transport;
-
-import net.sf.briar.api.TransportId;
-
-public interface ConnectionRecogniserFactory {
-
-	ConnectionRecogniser createConnectionRecogniser(TransportId t);
-}

api/net/sf/briar/api/transport/ConnectionWriterFactory.java

@@ -2,7 +2,7 @@ package net.sf.briar.api.transport;
 
 import java.io.OutputStream;
 
-import net.sf.briar.api.TransportId;
+import net.sf.briar.api.protocol.TransportIndex;
 
 public interface ConnectionWriterFactory {
 
@@ -11,12 +11,12 @@ public interface ConnectionWriterFactory {
 	 * initiator's side of a stream-mode connection.
 	 */
 	ConnectionWriter createConnectionWriter(OutputStream out, long capacity,
-			TransportId t, long connection, byte[] secret);
+			TransportIndex i, long connection, byte[] secret);
 
 	/**
 	 * Creates a connection writer for the responder's side of a stream-mode
 	 * connection.
 	 */
 	ConnectionWriter createConnectionWriter(OutputStream out, long capacity,
-			TransportId t, byte[] encryptedIv, byte[] secret);
+			TransportIndex i, byte[] encryptedIv, byte[] secret);
 }

api/net/sf/briar/api/transport/StreamConnectionFactory.java

@@ -1,13 +1,13 @@
 package net.sf.briar.api.transport;
 
 import net.sf.briar.api.ContactId;
-import net.sf.briar.api.TransportId;
+import net.sf.briar.api.protocol.TransportIndex;
 
 public interface StreamConnectionFactory {
 
-	void createIncomingConnection(TransportId t, ContactId c, 
+	void createIncomingConnection(TransportIndex i, ContactId c, 
 			StreamTransportConnection s, byte[] encryptedIv);
 
-	void createOutgoingConnection(TransportId t, ContactId c,
+	void createOutgoingConnection(TransportIndex i, ContactId c,
 			StreamTransportConnection s);
 }