/*
* Copyright 2014 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.container;
import org.apache.catalina.comet.CometEvent;
import org.apache.catalina.comet.CometEvent.EventType;
import org.apache.catalina.connector.Request;
import org.apache.catalina.connector.RequestFacade;
import org.apache.catalina.connector.Response;
import org.apache.catalina.connector.ResponseFacade;
import org.apache.tomcat.util.http.mapper.MappingData;
import org.atmosphere.cpr.Action;
import org.atmosphere.cpr.ApplicationConfig;
import org.atmosphere.cpr.AsyncSupport;
import org.atmosphere.cpr.AsynchronousProcessor;
import org.atmosphere.cpr.AtmosphereConfig;
import org.atmosphere.cpr.AtmosphereRequest;
import org.atmosphere.cpr.AtmosphereResource;
import org.atmosphere.cpr.AtmosphereResourceImpl;
import org.atmosphere.cpr.AtmosphereResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.servlet.ServletException;
import java.io.IOException;
import java.lang.reflect.Field;
import static org.atmosphere.cpr.ApplicationConfig.MAX_INACTIVE;
/**
* Comet Portable Runtime implementation on top of Tomcat AIO.
*
* @author Jeanfrancois Arcand
*/
public class Tomcat7CometSupport extends AsynchronousProcessor {
private static final Logger logger = LoggerFactory.getLogger(Tomcat7CometSupport.class);
public static final String COMET_EVENT = "CometEvent";
private final static String SUSPENDED = Tomcat7CometSupport.class.getName() + ".suspended";
private final Boolean closeConnectionOnInputStream;
private static final IllegalStateException unableToDetectComet
= new IllegalStateException(unableToDetectComet());
public Tomcat7CometSupport(AtmosphereConfig config) {
super(config);
Object b = config.getInitParameter(ApplicationConfig.TOMCAT_CLOSE_STREAM);
closeConnectionOnInputStream = b == null ? true : Boolean.parseBoolean(b.toString());
try {
Class.forName(CometEvent.class.getName());
} catch (Throwable e) {
logger.error("Unable to load class {}. Please make sure you have properly installed Atmosphere http://goo.gl/KEi8pc", e);
throw new IllegalStateException(unableToDetectComet());
}
}
/**
* Invoked by the Tomcat AIO when a Comet request gets detected.
*
* @param req the {@link AtmosphereRequest}
* @param res the {@link AtmosphereResponse}
* @throws java.io.IOException
* @throws javax.servlet.ServletException
*/
@Override
public Action service(AtmosphereRequest req, AtmosphereResponse res)
throws IOException, ServletException {
CometEvent event = (CometEvent) req.getAttribute(COMET_EVENT);
// Comet is not enabled.
if (event == null) {
throw unableToDetectComet;
}
logger.trace("event {} with request {}", event, req);
Action action = null;
// For now, we are just interested in CometEvent.READ
if (event.getEventType() == EventType.BEGIN) {
action = suspended(req, res);
if (action.type() == Action.TYPE.SUSPEND) {
// Do nothing except setting the times out
try {
if (action.timeout() != -1) {
event.setTimeout((int) action.timeout());
} else {
event.setTimeout(Integer.MAX_VALUE);
}
} catch (UnsupportedOperationException ex) {
// TODO: Must implement the same functionality using a Scheduler
logger.trace("Warning: CometEvent.setTimeout not supported on this Tomcat instance. " +
" [The Tomcat native connector does not support timeouts on asynchronous I/O.]");
}
req.setAttribute(SUSPENDED, true);
} else {
bz51881(event);
}
} else if (event.getEventType() == EventType.READ) {
// Not implemented
} else if (event.getEventSubType() == CometEvent.EventSubType.CLIENT_DISCONNECT) {
if (req.getAttribute(SUSPENDED) != null) {
req.setAttribute(SUSPENDED, null);
action = cancelled(req, res);
}
bz51881(event);
} else if (event.getEventSubType() == CometEvent.EventSubType.TIMEOUT) {
action = timedout(req, res);
bz51881(event);
} else if (event.getEventType() == EventType.ERROR) {
bz51881(event);
} else if (event.getEventType() == EventType.END) {
if (req.resource() != null && req.resource().isResumed()) {
AtmosphereResourceImpl.class.cast(req.resource()).cancel();
} else if (req.getAttribute(SUSPENDED) != null && closeConnectionOnInputStream) {
req.setAttribute(SUSPENDED, null);
action = cancelled(req, res);
} else {
bz51881(event);
}
}
return action;
}
private void bz51881(CometEvent event) throws IOException {
try {
String[] tomcatVersion = config.getServletContext().getServerInfo().substring(14).split("\\.");
String minorVersion = tomcatVersion[2];
if (minorVersion.indexOf("-") != -1) {
minorVersion = minorVersion.substring(0, minorVersion.indexOf("-"));
if (Integer.valueOf(minorVersion) == 22) {
minorVersion = "23";
}
}
if (Integer.valueOf(tomcatVersion[0]) == 7 && Integer.valueOf(minorVersion) < 23) {
logger.info("Patching Tomcat 7.0.22 and lower bz51881. Expect NPE inside CoyoteAdapter, just ignore them. Upgrade to 7.0.23");
try {
RequestFacade request = RequestFacade.class.cast(event.getHttpServletRequest());
Field coyoteRequest = RequestFacade.class.getDeclaredField("request");
coyoteRequest.setAccessible(true);
Request r = (Request) coyoteRequest.get(request);
r.recycle();
Field mappingData = Request.class.getDeclaredField("mappingData");
mappingData.setAccessible(true);
MappingData m = new MappingData();
m.context = null;
mappingData.set(r, m);
} catch (Throwable t) {
logger.trace("Was unable to recycle internal Tomcat object");
} finally {
try {
event.close();
} catch (IllegalStateException e) {
logger.trace("", e);
}
}
try {
ResponseFacade response = ResponseFacade.class.cast(event.getHttpServletResponse());
Field coyoteResponse = ResponseFacade.class.getDeclaredField("response");
coyoteResponse.setAccessible(true);
Response r = (Response) coyoteResponse.get(response);
r.recycle();
} catch (Throwable t) {
logger.trace("Was unable to recycle internal Tomcat object");
}
} else {
try {
event.close();
} catch (IllegalStateException ex) {
logger.trace("event.close", ex);
}
}
} catch (NumberFormatException ex) {
logger.trace("This is a mofified version of Tomcat {}", config.getServletContext().getServerInfo().substring(14).split("\\."));
try {
event.close();
} catch (IllegalStateException e) {
logger.trace("event.close", e);
}
}
}
@Override
public void action(AtmosphereResourceImpl r) {
super.action(r);
if (r.action().type() == Action.TYPE.RESUME && r.isInScope()) {
complete(r);
}
}
@Override
public AsyncSupport complete(AtmosphereResourceImpl r) {
try {
CometEvent event = (CometEvent) r.getRequest(false).getAttribute(COMET_EVENT);
if (event == null) return this;
// Resume without closing the underlying suspended connection.
if (!r.transport().equals(AtmosphereResource.TRANSPORT.WEBSOCKET)) {
bz51881(event);
}
} catch (IOException ex) {
logger.debug("action failed", ex);
}
return this;
}
@Override
public Action cancelled(AtmosphereRequest req, AtmosphereResponse res) throws IOException, ServletException {
Action action = super.cancelled(req, res);
if (req.getAttribute(MAX_INACTIVE) != null && Long.class.cast(req.getAttribute(MAX_INACTIVE)) == -1) {
CometEvent event = (CometEvent) req.getAttribute(COMET_EVENT);
if (event == null) return action;
bz51881(event);
}
return action;
}
/**
* Tomcat was unable to detect Atmosphere's CometProcessor implementation.
*
* @return an error message describing how to fix the issue.
*/
private static String unableToDetectComet() {
StringBuilder sb = new StringBuilder();
sb.append("Tomcat failed to detect this is a Comet application because context.xml ");
sb.append("is missing or the Http11NioProtocol Connector is not enabled.");
sb.append("You must use the atmosphere-native-runtime dependency in order to use native Comet Support");
sb.append("\nIf that's not the case, you can also remove META-INF/context.xml and WEB-INF/lib/atmosphere-compat-tomcat7.jar");
return sb.toString();
}
}