/**
* Copyright 2010 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.waveprotocol.box.webclient.client;
import static org.waveprotocol.wave.communication.gwt.JsonHelper.getPropertyAsInteger;
import static org.waveprotocol.wave.communication.gwt.JsonHelper.getPropertyAsObject;
import static org.waveprotocol.wave.communication.gwt.JsonHelper.getPropertyAsString;
import static org.waveprotocol.wave.communication.gwt.JsonHelper.setPropertyAsInteger;
import static org.waveprotocol.wave.communication.gwt.JsonHelper.setPropertyAsObject;
import static org.waveprotocol.wave.communication.gwt.JsonHelper.setPropertyAsString;
import com.google.common.base.Preconditions;
import com.google.gwt.core.client.Scheduler;
import com.google.gwt.core.client.Scheduler.RepeatingCommand;
import com.google.gwt.user.client.Cookies;
import org.waveprotocol.box.common.comms.jso.ProtocolAuthenticateJsoImpl;
import org.waveprotocol.box.common.comms.jso.ProtocolOpenRequestJsoImpl;
import org.waveprotocol.box.common.comms.jso.ProtocolSubmitRequestJsoImpl;
import org.waveprotocol.box.common.comms.jso.ProtocolSubmitResponseJsoImpl;
import org.waveprotocol.box.common.comms.jso.ProtocolWaveletUpdateJsoImpl;
import org.waveprotocol.box.webclient.client.events.NetworkStatusEvent;
import org.waveprotocol.box.webclient.client.events.NetworkStatusEvent.ConnectionStatus;
import org.waveprotocol.box.webclient.client.events.Log;
import org.waveprotocol.wave.communication.gwt.JsonMessage;
import org.waveprotocol.wave.communication.json.JsonException;
import org.waveprotocol.wave.model.util.CollectionUtils;
import org.waveprotocol.wave.model.util.IntMap;
import java.util.Queue;
/**
* Wrapper around SocketIO that handles the FedOne client-server protocol.
*/
public class WaveWebSocketClient implements WaveSocket.WaveSocketCallback {
private static final Log LOG = Log.get(WaveWebSocketClient.class);
private static final int RECONNECT_TIME_MS = 5000;
private static final String JETTY_SESSION_TOKEN_NAME = "JSESSIONID";
/**
* Envelope for delivering arbitrary messages. Each envelope has a sequence
* number and a message. The format must match the format used in the server's
* WebSocketChannel.
* <p>
* Note that this message can not be described by a protobuf, because it
* contains an arbitrary protobuf, which breaks the protobuf typing rules.
*/
private static final class MessageWrapper extends JsonMessage {
static MessageWrapper create(int seqno, String type, JsonMessage message) {
MessageWrapper wrapper = JsonMessage.createJsonMessage().cast();
setPropertyAsInteger(wrapper, "sequenceNumber", seqno);
setPropertyAsString(wrapper, "messageType", type);
setPropertyAsObject(wrapper, "message", message);
return wrapper;
}
@SuppressWarnings("unused") // GWT requires an explicit protected ctor
protected MessageWrapper() {
super();
}
int getSequenceNumber() {
return getPropertyAsInteger(this, "sequenceNumber");
}
String getType() {
return getPropertyAsString(this, "messageType");
}
<T extends JsonMessage> T getPayload() {
return getPropertyAsObject(this, "message").<T>cast();
}
}
private final WaveSocket socket;
private final IntMap<SubmitResponseCallback> submitRequestCallbacks;
/**
* Lifecycle of a socket is:
* (CONNECTING → CONNECTED → DISCONNECTED)∗
*/
private enum ConnectState {
CONNECTED, CONNECTING, DISCONNECTED
}
private ConnectState connected = ConnectState.DISCONNECTED;
private WaveWebSocketCallback callback;
private int sequenceNo;
private final Queue<JsonMessage> messages = CollectionUtils.createQueue();
private final RepeatingCommand reconnectCommand = new RepeatingCommand() {
@Override
public boolean execute() {
if (connected == ConnectState.DISCONNECTED) {
LOG.info("Attemping to reconnect");
connected = ConnectState.CONNECTING;
socket.connect();
}
return true;
}
};
public WaveWebSocketClient(boolean useSocketIO, String urlBase) {
submitRequestCallbacks = CollectionUtils.createIntMap();
socket = WaveSocketFactory.create(useSocketIO, urlBase, this);
}
/**
* Attaches the handler for incoming messages. Once the client's workflow has
* been fixed, this callback attachment will become part of
* {@link #connect()}.
*/
public void attachHandler(WaveWebSocketCallback callback) {
Preconditions.checkState(this.callback == null);
Preconditions.checkArgument(callback != null);
this.callback = callback;
}
/**
* Opens this connection.
*/
public void connect() {
reconnectCommand.execute();
Scheduler.get().scheduleFixedDelay(reconnectCommand, RECONNECT_TIME_MS);
}
@Override
public void onConnect() {
connected = ConnectState.CONNECTED;
// Sends the session cookie to the server via an RPC to work around browser bugs.
// See: http://code.google.com/p/wave-protocol/issues/detail?id=119
String token = Cookies.getCookie(JETTY_SESSION_TOKEN_NAME);
if (token != null) {
ProtocolAuthenticateJsoImpl auth = ProtocolAuthenticateJsoImpl.create();
auth.setToken(token);
send(MessageWrapper.create(sequenceNo++, "ProtocolAuthenticate", auth));
}
// Flush queued messages.
while (!messages.isEmpty() && connected == ConnectState.CONNECTED) {
send(messages.poll());
}
ClientEvents.get().fireEvent(new NetworkStatusEvent(ConnectionStatus.CONNECTED));
}
@Override
public void onDisconnect() {
connected = ConnectState.DISCONNECTED;
ClientEvents.get().fireEvent(new NetworkStatusEvent(ConnectionStatus.DISCONNECTED));
}
@Override
public void onMessage(final String message) {
LOG.info("received JSON message " + message);
MessageWrapper wrapper;
try {
wrapper = MessageWrapper.parse(message);
} catch (JsonException e) {
LOG.severe("invalid JSON message " + message, e);
return;
}
String messageType = wrapper.getType();
if ("ProtocolWaveletUpdate".equals(messageType)) {
if (callback != null) {
callback.onWaveletUpdate(wrapper.<ProtocolWaveletUpdateJsoImpl>getPayload());
}
} else if ("ProtocolSubmitResponse".equals(messageType)) {
int seqno = wrapper.getSequenceNumber();
SubmitResponseCallback callback = submitRequestCallbacks.get(seqno);
if (callback != null) {
submitRequestCallbacks.remove(seqno);
callback.run(wrapper.<ProtocolSubmitResponseJsoImpl>getPayload());
}
}
}
public void submit(ProtocolSubmitRequestJsoImpl message, SubmitResponseCallback callback) {
int submitId = sequenceNo++;
submitRequestCallbacks.put(submitId, callback);
send(MessageWrapper.create(submitId, "ProtocolSubmitRequest", message));
}
public void open(ProtocolOpenRequestJsoImpl message) {
send(MessageWrapper.create(sequenceNo++, "ProtocolOpenRequest", message));
}
private void send(JsonMessage message) {
switch (connected) {
case CONNECTED:
String json = message.toJson();
LOG.info("Sending JSON data " + json);
socket.sendMessage(json);
break;
default:
messages.add(message);
}
}
}