/*
* Copyright 2011 Jeanfrancois Arcand
*
* 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.atmosphere.gwt.server.impl;
import com.google.gwt.rpc.server.ClientOracle;
import com.google.gwt.user.server.rpc.SerializationPolicy;
import java.io.IOException;
import java.io.OutputStream;
import java.io.Serializable;
import java.util.List;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.atmosphere.gwt.server.GwtAtmosphereResource;
import org.atmosphere.gwt.server.AtmosphereGwtHandler;
import org.atmosphere.gwt.server.GwtResponseWriter;
import java.util.Collection;
import org.atmosphere.cpr.AtmosphereEventLifecycle;
import org.atmosphere.cpr.AtmosphereResource;
import org.atmosphere.cpr.AtmosphereResourceEvent;
import org.atmosphere.cpr.AtmosphereResourceEventListener;
import org.atmosphere.cpr.Broadcaster;
import org.atmosphere.cpr.Serializer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
*
* @author p.havelaar
*/
public class GwtAtmosphereResourceImpl implements GwtAtmosphereResource {
public GwtAtmosphereResourceImpl(AtmosphereResource<HttpServletRequest, HttpServletResponse> resource,
AtmosphereGwtHandler servlet, int heartBeatInterval) throws IOException {
this.atmosphereHandler = servlet;
this.atmResource = resource;
this.heartBeatInterval = heartBeatInterval;
this.writer = createResponseWriter();
resource.getRequest().setAttribute(GwtAtmosphereResource.class.getName(), this);
}
@Override
public Broadcaster getBroadcaster() {
return atmResource.getBroadcaster();
}
@Override
public HttpSession getSession() {
return atmResource.getRequest().getSession();
}
@Override
public HttpSession getSession(boolean create) {
return atmResource.getRequest().getSession(create);
}
GwtResponseWriter getResponseWriter() {
return writer;
}
@Override
public int getHeartBeatInterval() {
return heartBeatInterval;
}
@Override
public void broadcast(Serializable message) {
getBroadcaster().broadcast(message, atmResource);
}
@Override
public void broadcast(List<Serializable> messages) {
getBroadcaster().broadcast(messages, atmResource);
}
@Override
public void post(Serializable message) {
getBroadcaster().broadcast(message, atmResource);
}
@Override
public void post(List<Serializable> messages) {
getBroadcaster().broadcast(messages, atmResource);
}
@Override
public AtmosphereResource<HttpServletRequest, HttpServletResponse> getAtmosphereResource() {
return atmResource;
}
/**
* Check to see if this atmosphere resource is still in use by the system.
* It will query the associated broadcaster if it is still referenced.
*
* @param resource
* @return
*/
@Override
public boolean isAlive() {
if (writer.isTerminated()) {
return false;
}
if ((System.currentTimeMillis() - startTime) < WARMUP_TIME) {
return true;
}
if (atmResource.getBroadcaster() == null) {
return false;
}
Collection<AtmosphereResource<?,?>> res = atmResource.getBroadcaster().getAtmosphereResources();
for (AtmosphereResource<?,?> ar : res) {
if (ar == atmResource) {
return true;
}
}
return suspended;
}
long getStartTime() {
return startTime;
}
@Override
public HttpServletRequest getRequest() {
return atmResource.getRequest();
}
@Override
public int getConnectionID() {
return writer.connectionID;
}
public void suspend() throws IOException {
suspend(-1);
}
public void suspend(int timeout) throws IOException {
if (!suspended) {
atmResource.setSerializer(serializer);
if (atmResource instanceof AtmosphereEventLifecycle) {
AtmosphereEventLifecycle ael = (AtmosphereEventLifecycle)atmResource;
ael.addEventListener(eventListener);
}
writer.suspend();
atmResource.suspend(timeout, false);
}
}
public void resume() {
atmResource.resume();
}
/** this will be called by the writer to resume an already dead connection.
* Because this can possibly block for as long as the timeout of http connections we do this in
* 1 or more seperate threads
*/
void resumeAfterDeath() {
atmosphereHandler.execute(new Runnable() {
@Override
public void run() {
atmResource.resume();
}
});
}
@Override
public <T> void setAttribute(String name, T value) {
atmResource.getRequest().setAttribute(name, value);
}
@Override
public <T> T getAttribute(String name) {
return (T) atmResource.getRequest().getAttribute(name);
}
public GwtResponseWriterImpl getWriterImpl() {
return writer;
}
ScheduledFuture<?> scheduleHeartbeat() {
return getBroadcaster().getBroadcasterConfig().getScheduledExecutorService()
.schedule(heartBeatTask, heartBeatInterval, TimeUnit.MILLISECONDS);
}
void terminate(boolean serverInitiated) {
AtmosphereGwtHandler s = atmosphereHandler;
if (s != null) {
atmosphereHandler = null;
if (suspended) {
atmResource.resume();
}
s.cometTerminated(this, serverInitiated);
}
}
private GwtResponseWriterImpl createResponseWriter() throws IOException {
ClientOracle clientOracle = RPCUtil.getClientOracle(atmResource.getRequest(), atmosphereHandler.getServletContext());
SerializationPolicy serializationPolicy = clientOracle == null ? RPCUtil.createSimpleSerializationPolicy() : null;
String transport = atmResource.getRequest().getParameter("tr");
if ("WebSocket".equals(transport)) {
logger.debug("atmosphere-gwt Using websocket");
return new WebsocketResponseWriter(this, serializationPolicy, clientOracle);
} else if ("HTTPRequest".equals(transport)) {
logger.debug("atmosphere-gwt Using XMLHttpRequest");
return new HTTPRequestResponseWriter(this, serializationPolicy, clientOracle);
} else if ("IFrame".equals(transport)) {
logger.debug("atmosphere-gwt Using streaming IFrame");
return new IFrameResponseWriter(this, serializationPolicy, clientOracle);
} else if ("OperaEventSource".equals(transport)) {
logger.debug("atmosphere-gwt Using Opera EventSource");
return new OperaEventSourceResponseWriter(this, serializationPolicy, clientOracle);
} else if ("IEXDomainRequest".equals(transport)) {
logger.debug("atmosphere-gwt Using IE XDomainRequest");
return new IEXDomainRequestResponseWriter(this, serializationPolicy, clientOracle);
} else if ("IEHTMLFile".equals(transport)) {
logger.debug("atmosphere-gwt Using IE html file iframe");
return new IEHTMLFileResponseWriter(this, serializationPolicy, clientOracle);
} else {
throw new IllegalStateException("Failed to determine responsewriter");
}
}
private final static long WARMUP_TIME = 10000;
private long startTime = System.currentTimeMillis();
private final GwtResponseWriterImpl writer;
private AtmosphereResource<HttpServletRequest, HttpServletResponse> atmResource;
private final int heartBeatInterval;
private Heartbeat heartBeatMessage = new Heartbeat();
private AtmosphereGwtHandler atmosphereHandler;
private boolean suspended = false;
private Logger logger = LoggerFactory.getLogger(getClass());
private Runnable heartBeatTask = new Runnable() {
@Override
public void run() {
if (isAlive()) {
broadcast(heartBeatMessage);
}
}
};
private final Serializer serializer = new Serializer() {
@Override
public void write(OutputStream out, Object o) throws IOException {
if (o instanceof Serializable) {
try {
writer.write((Serializable)o);
} catch (IOException e) {
if (writer.isTerminated()) {
logger.debug("broadcast failed, connection terminated:" + e.getMessage(), e);
}
throw e;
}
} else if (o instanceof List) {
List<?> list = (List)o;
if (list.size() > 0) {
if (!(list.get(0) instanceof Serializable)) {
throw new IOException("Failed to write a list of objects that are not serializable");
}
writer.write((List<Serializable>)o);
}
} else {
logger.warn("Failed to write an object that is not serializable");
}
}
};
private final AtmosphereResourceEventListener eventListener = new AtmosphereResourceEventListener() {
@Override
public void onSuspend(AtmosphereResourceEvent<HttpServletRequest, HttpServletResponse> are) {
suspended = true;
}
@Override
public void onResume(AtmosphereResourceEvent<HttpServletRequest, HttpServletResponse> event) {
suspended = false;
writer.setTerminated(false);
}
@Override
public void onDisconnect(AtmosphereResourceEvent<HttpServletRequest, HttpServletResponse> event) {
suspended = false;
writer.setTerminated(false);
}
@Override
public void onBroadcast(AtmosphereResourceEvent<HttpServletRequest, HttpServletResponse> event) {
}
@Override
public void onThrowable(AtmosphereResourceEvent<HttpServletRequest, HttpServletResponse> event) {
}
};
}