Add plumbing for creating outgoing sync sessions.

bramble-api/src/main/java/org/briarproject/bramble/api/connection/ConnectionManager.java

@@ -7,6 +7,7 @@ import org.briarproject.bramble.api.plugin.TransportConnectionReader;
 import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
+import org.briarproject.bramble.api.sync.OutgoingSessionRecord;
 
 @NotNullByDefault
 public interface ConnectionManager {
@@ -45,6 +46,14 @@ public interface ConnectionManager {
 	void manageOutgoingConnection(ContactId c, TransportId t,
 			TransportConnectionWriter w);
 
+	/**
+	 * Manages an outgoing connection to a contact via a mailbox. The IDs of
+	 * any messages sent or acked are added to the given
+	 * {@link OutgoingSessionRecord}.
+	 */
+	void manageOutgoingConnection(ContactId c, TransportId t,
+			TransportConnectionWriter w, OutgoingSessionRecord sessionRecord);
+
 	/**
 	 * Manages an outgoing connection to a contact over a duplex transport.
 	 */

bramble-api/src/main/java/org/briarproject/bramble/api/sync/SyncSessionFactory.java

@@ -12,12 +12,30 @@ import javax.annotation.Nullable;
 @NotNullByDefault
 public interface SyncSessionFactory {
 
+	/**
+	 * Creates a session for receiving data from a contact.
+	 */
 	SyncSession createIncomingSession(ContactId c, InputStream in,
 			PriorityHandler handler);
 
+	/**
+	 * Creates a session for sending data to a contact over a simplex transport.
+	 *
+	 * @param eager True if messages should be sent eagerly, ie regardless of
+	 * whether they're due for retransmission.
+	 */
 	SyncSession createSimplexOutgoingSession(ContactId c, TransportId t,
 			long maxLatency, boolean eager, StreamWriter streamWriter);
 
+	/**
+	 * Creates a session for sending data to a contact via a mailbox. The IDs
+	 * of any messages sent or acked will be added to the given
+	 * {@link OutgoingSessionRecord}.
+	 */
+	SyncSession createSimplexOutgoingSession(ContactId c, TransportId t,
+			long maxLatency, StreamWriter streamWriter,
+			OutgoingSessionRecord sessionRecord);
+
 	SyncSession createDuplexOutgoingSession(ContactId c, TransportId t,
 			long maxLatency, int maxIdleTime, StreamWriter streamWriter,
 			@Nullable Priority priority);

bramble-core/src/main/java/org/briarproject/bramble/connection/ConnectionManagerImpl.java

@@ -13,6 +13,7 @@ import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 import org.briarproject.bramble.api.properties.TransportPropertyManager;
+import org.briarproject.bramble.api.sync.OutgoingSessionRecord;
 import org.briarproject.bramble.api.sync.SyncSessionFactory;
 import org.briarproject.bramble.api.transport.KeyManager;
 import org.briarproject.bramble.api.transport.StreamReaderFactory;
@@ -100,7 +101,16 @@ class ConnectionManagerImpl implements ConnectionManager {
 			TransportConnectionWriter w) {
 		ioExecutor.execute(new OutgoingSimplexSyncConnection(keyManager,
 				connectionRegistry, streamReaderFactory, streamWriterFactory,
-				syncSessionFactory, transportPropertyManager, c, t, w));
+				syncSessionFactory, transportPropertyManager, c, t, w, null));
+	}
+
+	@Override
+	public void manageOutgoingConnection(ContactId c, TransportId t,
+			TransportConnectionWriter w, OutgoingSessionRecord sessionRecord) {
+		ioExecutor.execute(new OutgoingSimplexSyncConnection(keyManager,
+				connectionRegistry, streamReaderFactory, streamWriterFactory,
+				syncSessionFactory, transportPropertyManager, c, t, w,
+				sessionRecord));
 	}
 
 	@Override

bramble-core/src/main/java/org/briarproject/bramble/connection/OutgoingSimplexSyncConnection.java

@@ -6,6 +6,7 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.properties.TransportPropertyManager;
+import org.briarproject.bramble.api.sync.OutgoingSessionRecord;
 import org.briarproject.bramble.api.sync.SyncSession;
 import org.briarproject.bramble.api.sync.SyncSessionFactory;
 import org.briarproject.bramble.api.transport.KeyManager;
@@ -16,6 +17,8 @@ import org.briarproject.bramble.api.transport.StreamWriterFactory;
 
 import java.io.IOException;
 
+import javax.annotation.Nullable;
+
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
 import static org.briarproject.bramble.util.LogUtils.logException;
@@ -26,6 +29,8 @@ class OutgoingSimplexSyncConnection extends SyncConnection implements Runnable {
 	private final ContactId contactId;
 	private final TransportId transportId;
 	private final TransportConnectionWriter writer;
+	@Nullable
+	private final OutgoingSessionRecord sessionRecord;
 
 	OutgoingSimplexSyncConnection(KeyManager keyManager,
 			ConnectionRegistry connectionRegistry,
@@ -34,13 +39,15 @@ class OutgoingSimplexSyncConnection extends SyncConnection implements Runnable {
 			SyncSessionFactory syncSessionFactory,
 			TransportPropertyManager transportPropertyManager,
 			ContactId contactId, TransportId transportId,
-			TransportConnectionWriter writer) {
+			TransportConnectionWriter writer,
+			@Nullable OutgoingSessionRecord sessionRecord) {
 		super(keyManager, connectionRegistry, streamReaderFactory,
 				streamWriterFactory, syncSessionFactory,
 				transportPropertyManager);
 		this.contactId = contactId;
 		this.transportId = transportId;
 		this.writer = writer;
+		this.sessionRecord = sessionRecord;
 	}
 
 	@Override
@@ -71,10 +78,16 @@ class OutgoingSimplexSyncConnection extends SyncConnection implements Runnable {
 		StreamWriter streamWriter = streamWriterFactory.createStreamWriter(
 				w.getOutputStream(), ctx);
 		ContactId c = requireNonNull(ctx.getContactId());
-		// Use eager retransmission if the transport is lossy and cheap
+		if (sessionRecord == null) {
-		return syncSessionFactory.createSimplexOutgoingSession(c,
+			// Use eager retransmission if the transport is lossy and cheap
-				ctx.getTransportId(), w.getMaxLatency(), w.isLossyAndCheap(),
+			return syncSessionFactory.createSimplexOutgoingSession(c,
-				streamWriter);
+					ctx.getTransportId(), w.getMaxLatency(),
+					w.isLossyAndCheap(), streamWriter);
+		} else {
+			return syncSessionFactory.createSimplexOutgoingSession(c,
+					ctx.getTransportId(), w.getMaxLatency(), streamWriter,
+					sessionRecord);
+		}
 	}
 }
 

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

@@ -6,6 +6,7 @@ import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.sync.OutgoingSessionRecord;
 import org.briarproject.bramble.api.sync.Priority;
 import org.briarproject.bramble.api.sync.PriorityHandler;
 import org.briarproject.bramble.api.sync.SyncRecordReader;
@@ -25,6 +26,8 @@ import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
+import static org.briarproject.bramble.api.mailbox.MailboxConstants.MAX_FILE_PAYLOAD_BYTES;
+
 @Immutable
 @NotNullByDefault
 class SyncSessionFactoryImpl implements SyncSessionFactory {
@@ -73,6 +76,18 @@ class SyncSessionFactoryImpl implements SyncSessionFactory {
 		}
 	}
 
+	@Override
+	public SyncSession createSimplexOutgoingSession(ContactId c, TransportId t,
+			long maxLatency, StreamWriter streamWriter,
+			OutgoingSessionRecord sessionRecord) {
+		OutputStream out = streamWriter.getOutputStream();
+		SyncRecordWriter recordWriter =
+				recordWriterFactory.createRecordWriter(out);
+		return new MailboxOutgoingSession(db, eventBus, c, t, maxLatency,
+				streamWriter, recordWriter, sessionRecord,
+				MAX_FILE_PAYLOAD_BYTES);
+	}
+
 	@Override
 	public SyncSession createDuplexOutgoingSession(ContactId c, TransportId t,
 			long maxLatency, int maxIdleTime, StreamWriter streamWriter,