/*
* Copyright (c) 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017 David Berkman
*
* This file is part of the SmallMind Code Project.
*
* The SmallMind Code Project is free software, you can redistribute
* it and/or modify it under either, at your discretion...
*
* 1) The terms of GNU Affero General Public License as published by the
* Free Software Foundation, either version 3 of the License, or (at
* your option) any later version.
*
* ...or...
*
* 2) The terms of the Apache License, Version 2.0.
*
* The SmallMind Code Project is distributed in the hope that it will
* be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License or Apache License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* and the Apache License along with the SmallMind Code Project. If not, see
* <http://www.gnu.org/licenses/> or <http://www.apache.org/licenses/LICENSE-2.0>.
*
* Additional permission under the GNU Affero GPL version 3 section 7
* ------------------------------------------------------------------
* If you modify this Program, or any covered work, by linking or
* combining it with other code, such other code is not for that reason
* alone subject to any of the requirements of the GNU Affero GPL
* version 3.
*/
package org.smallmind.phalanx.wire.amqp.rabbitmq;
import java.io.IOException;
import java.util.Date;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicStampedReference;
import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.AlreadyClosedException;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.ShutdownListener;
import com.rabbitmq.client.ShutdownSignalException;
import org.smallmind.scribe.pen.LoggerManager;
public abstract class MessageRouter {
private final AtomicBoolean closed = new AtomicBoolean(false);
private final AtomicStampedReference<Channel> channelRef = new AtomicStampedReference<>(null, 0);
private final AtomicInteger version = new AtomicInteger(0);
private final RabbitMQConnector connector;
private final NameConfiguration nameConfiguration;
public MessageRouter (RabbitMQConnector connector, NameConfiguration nameConfiguration) {
this.connector = connector;
this.nameConfiguration = nameConfiguration;
}
public abstract void bindQueues ()
throws IOException;
public abstract void installConsumer ()
throws IOException;
public void initialize ()
throws IOException, TimeoutException {
ensureChannel(0);
}
public String getRequestExchangeName () {
return nameConfiguration.getRequestExchange();
}
public String getResponseExchangeName () {
return nameConfiguration.getResponseExchange();
}
public String getResponseQueueName () {
return nameConfiguration.getResponseQueue();
}
public String getShoutQueueName () {
return nameConfiguration.getShoutQueue();
}
public String getTalkQueueName () {
return nameConfiguration.getTalkQueue();
}
public String getWhisperQueueName () {
return nameConfiguration.getWhisperQueue();
}
private void ensureChannel (int stamp)
throws IOException, TimeoutException {
synchronized (channelRef) {
if (channelRef.getStamp() == stamp) {
Channel channel;
final int nextStamp;
channel = connector.getConnection().createChannel();
channel.basicQos(0, 1, false);
channel.exchangeDeclare(getRequestExchangeName(), "direct", false, false, null);
channel.exchangeDeclare(getResponseExchangeName(), "direct", false, false, null);
channelRef.set(channel, nextStamp = version.incrementAndGet());
channel.addShutdownListener(new ShutdownListener() {
@Override
public void shutdownCompleted (ShutdownSignalException cause) {
try {
if (!closed.get()) {
ensureChannel(nextStamp);
}
} catch (IOException | TimeoutException exception) {
LoggerManager.getLogger(RabbitMQConnector.class).error(exception);
}
}
});
bindQueues();
installConsumer();
}
}
}
public void operate (ChannelOperation channelOperation)
throws IOException {
synchronized (channelRef) {
channelOperation.execute(channelRef.getReference());
}
}
public void send (String routingKey, String exchangeName, AMQP.BasicProperties properties, byte[] body)
throws IOException, TimeoutException {
boolean sent = false;
do {
int[] stampHolder = new int[1];
Channel channel = channelRef.get(stampHolder);
try {
channel.basicPublish(exchangeName, routingKey, true, false, properties, body);
sent = true;
} catch (AlreadyClosedException exception) {
ensureChannel(stampHolder[0]);
}
} while (!sent);
}
public long getTimestamp (AMQP.BasicProperties properties) {
Date date;
if ((date = properties.getTimestamp()) != null) {
return date.getTime();
}
return Long.MAX_VALUE;
}
public void close ()
throws IOException, TimeoutException {
if (closed.compareAndSet(false, true)) {
synchronized (channelRef) {
channelRef.getReference().close();
}
}
}
}