/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.tomcat.bayeux;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Queue;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.atomic.AtomicInteger;
import org.apache.cometd.bayeux.Bayeux;
import org.apache.cometd.bayeux.Client;
import org.apache.cometd.bayeux.Listener;
import org.apache.cometd.bayeux.Message;
import org.apache.tomcat.util.json.JSONObject;
import org.jboss.logging.Logger;
import org.jboss.servlet.http.HttpEvent;
public class ClientImpl implements Client {
private static Logger log = Logger.getLogger(ClientImpl.class);
public static final int SUPPORT_CALLBACK_POLL = 0x1;
public static final int SUPPORT_LONG_POLL = 0x2;
public static final String COMET_EVENT_ATTR = "org.apache.cometd.bayeux.client";
protected static LinkedList<Message> EMPTY_LIST = new LinkedList<Message>();
/**
* queued message for remote clients.
*/
protected LinkedList<Message> messages = null;
/**
* Currently associated event.
*/
protected HttpEvent event;
/**
* Unique id representing this client
*/
protected String id;
/**
* supported connection types, defaults to long-polling
*/
protected int supportedConnTypes = SUPPORT_LONG_POLL | SUPPORT_CALLBACK_POLL;
/**
* The desired connection type
*/
protected int desirectConnType = SUPPORT_LONG_POLL;
/**
* Does this client use json-comment-filtered messages
*/
protected boolean useJsonFiltered = false;
/**
* Same JVM clients, get local=true
*/
protected boolean local;
/**
* The callback object for local clients
*/
protected Listener listener;
protected AtomicInteger nrofsubscriptions = new AtomicInteger(0);
protected ClientImpl(String id, boolean local) {
this.id = id;
this.local = local;
if (!local) messages = new LinkedList<Message>();
}
/* protected ClientImpl(String id, HttpEvent event) {
this(id,false);
addCometEvent(event);
}*/
public void deliver(Message message) {
deliverInternal(null,new MessageImpl[] {(MessageImpl)message});
}
public void deliver(Message[] message) {
deliverInternal(null,message);
}
protected void deliverInternal(ChannelImpl channel, MessageImpl message) {
deliverInternal(channel,new MessageImpl[] {message});
}
protected synchronized void deliverInternal(ChannelImpl channel, Message[] msgs) {
if (isLocal()) {
//local clients must have a listener
ArrayList<Message> list = new ArrayList<Message>();
for (int i=0; msgs!=null && i<msgs.length; i++) {
//dont deliver to ourselves
if (this!=msgs[i].getClient()) list.add(msgs[i]);
}
if (getListener() != null && list.size()>0) {
getListener().deliver(list.toArray(new Message[0]));
}
} else {
for (int i=0; msgs!=null && i<msgs.length; i++) {
MessageImpl message = (MessageImpl)msgs[i];
if (this==message.getClient()) {
//dont deliver to ourself
continue;
}
//we are not implementing forever responses, if the client is connected
//then we will fire off the message
//first we check to see if we have any existing connections we can piggy back on
boolean delivered = false;
if (event!=null) {
RequestBase rq = (RequestBase)event.getHttpServletRequest().getAttribute(RequestBase.LAST_REQ_ATTR);
if (rq!=null) {
Map map = new HashMap();
try {
map.put(Bayeux.CHANNEL_FIELD,message.getChannel().getId());
map.put(Bayeux.DATA_FIELD,message);
JSONObject json = new JSONObject(map);
if (log.isTraceEnabled()) {
log.trace("Message instantly delivered to remote client["+this+"] message:"+json);
}
rq.addToDeliveryQueue(this, json);
//deliver the batch
if (i==(msgs.length-1)) {
rq.deliver(event, this);
event.close(); //todo, figure out a better way, this means only one message gets delivered
removeCometEvent(event); //and delivered instantly
}
delivered = true;
} catch (Exception e) {
// TODO: fix
log.warn("Exception", e);
}
}
}
if (!delivered) {
if (log.isTraceEnabled()) {
log.trace("Message added to queue for remote client["+this+"] message:"+message);
}
//queue the message for the next round
messages.add(message);
}
}
}
}
public String getId() {
return this.id;
}
protected Listener getListener() {
return listener;
}
public boolean hasMessages() {
if (isLocal()) return false;
else {
return messages.size() > 0;
}
}
public boolean isLocal() {
return local;
}
public int getSupportedConnTypes() {
return supportedConnTypes;
}
public int getDesirectConnType() {
return desirectConnType;
}
public boolean useJsonFiltered() {
return useJsonFiltered;
}
public void setListener(Listener listener) {
this.listener = listener;
}
public void setSupportedConnTypes(int supportedConnTypes) {
this.supportedConnTypes = supportedConnTypes;
}
public void setUseJsonFiltered(boolean useJsonFiltered) {
this.useJsonFiltered = useJsonFiltered;
}
public void setDesirectConnType(int desirectConnType) {
this.desirectConnType = desirectConnType;
}
public boolean supportsCallbackPoll() {
return (supportedConnTypes & SUPPORT_CALLBACK_POLL) == SUPPORT_CALLBACK_POLL;
}
public boolean supportsLongPoll() {
return (supportedConnTypes & SUPPORT_LONG_POLL) == SUPPORT_LONG_POLL;
}
public synchronized List<Message> takeMessages() {
if (isLocal()) return null;
if (messages.size()==0) return EMPTY_LIST;
List result = new LinkedList(messages);
messages.clear();
return result;
}
public String toString() {
StringBuilder buf = new StringBuilder(super.toString());
buf.append(" id=").append(getId());
return buf.toString();
}
public boolean isSubscribed() {
return nrofsubscriptions.get()>0;
}
protected void addCometEvent(HttpEvent event) {
if (this.event != null) {
try {
this.event.close();
} catch (IOException e) {
// Nothing
}
}
this.event = event;
event.getHttpServletRequest().setAttribute(COMET_EVENT_ATTR,this);
}
protected void removeCometEvent(HttpEvent event) {
if (this.event != null && this.event == event) {
this.event = null;
}
event.getHttpServletRequest().removeAttribute(COMET_EVENT_ATTR);
}
protected void subscribed(ChannelImpl ch) {
nrofsubscriptions.addAndGet(1);
}
protected void unsubscribed(ChannelImpl ch) {
nrofsubscriptions.addAndGet(-1);
}
public void startBatch(){
//noop until improved
}
public void endBatch() {
//noop until improved
}
}