/**
* 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.activemq.transport.mqtt.strategy;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import org.apache.activemq.broker.BrokerService;
import org.apache.activemq.broker.BrokerServiceAware;
import org.apache.activemq.broker.ConnectionContext;
import org.apache.activemq.broker.region.DurableTopicSubscription;
import org.apache.activemq.broker.region.PrefetchSubscription;
import org.apache.activemq.broker.region.RegionBroker;
import org.apache.activemq.broker.region.Subscription;
import org.apache.activemq.broker.region.TopicRegion;
import org.apache.activemq.broker.region.virtual.VirtualTopicInterceptor;
import org.apache.activemq.command.ActiveMQDestination;
import org.apache.activemq.command.ActiveMQTopic;
import org.apache.activemq.command.ConsumerId;
import org.apache.activemq.command.ConsumerInfo;
import org.apache.activemq.command.ExceptionResponse;
import org.apache.activemq.command.RemoveInfo;
import org.apache.activemq.command.RemoveSubscriptionInfo;
import org.apache.activemq.command.Response;
import org.apache.activemq.command.SubscriptionInfo;
import org.apache.activemq.transport.mqtt.MQTTProtocolConverter;
import org.apache.activemq.transport.mqtt.MQTTProtocolException;
import org.apache.activemq.transport.mqtt.MQTTProtocolSupport;
import org.apache.activemq.transport.mqtt.MQTTSubscription;
import org.apache.activemq.transport.mqtt.ResponseHandler;
import org.apache.activemq.util.LongSequenceGenerator;
import org.fusesource.mqtt.client.QoS;
import org.fusesource.mqtt.client.Topic;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Abstract implementation of the {@link MQTTSubscriptionStrategy} interface providing
* the base functionality that is common to most implementations.
*/
public abstract class AbstractMQTTSubscriptionStrategy implements MQTTSubscriptionStrategy, BrokerServiceAware {
private static final Logger LOG = LoggerFactory.getLogger(AbstractMQTTSubscriptionStrategy.class);
private static final byte SUBSCRIBE_ERROR = (byte) 0x80;
protected MQTTProtocolConverter protocol;
protected BrokerService brokerService;
protected final ConcurrentMap<ConsumerId, MQTTSubscription> subscriptionsByConsumerId = new ConcurrentHashMap<ConsumerId, MQTTSubscription>();
protected final ConcurrentMap<String, MQTTSubscription> mqttSubscriptionByTopic = new ConcurrentHashMap<String, MQTTSubscription>();
protected final Set<String> restoredDurableSubs = Collections.synchronizedSet(new HashSet<String>());
protected final LongSequenceGenerator consumerIdGenerator = new LongSequenceGenerator();
@Override
public void initialize(MQTTProtocolConverter protocol) throws MQTTProtocolException {
setProtocolConverter(protocol);
}
@Override
public void setBrokerService(BrokerService brokerService) {
this.brokerService = brokerService;
}
@Override
public void setProtocolConverter(MQTTProtocolConverter parent) {
this.protocol = parent;
}
@Override
public MQTTProtocolConverter getProtocolConverter() {
return protocol;
}
@Override
public byte onSubscribe(final Topic topic) throws MQTTProtocolException {
final String destinationName = topic.name().toString();
final QoS requestedQoS = topic.qos();
final MQTTSubscription mqttSubscription = mqttSubscriptionByTopic.get(destinationName);
if (mqttSubscription != null) {
if (requestedQoS != mqttSubscription.getQoS()) {
// remove old subscription as the QoS has changed
onUnSubscribe(destinationName);
} else {
try {
onReSubscribe(mqttSubscription);
} catch (IOException e) {
throw new MQTTProtocolException("Failed to find subscription strategy", true, e);
}
return (byte) requestedQoS.ordinal();
}
}
try {
return onSubscribe(destinationName, requestedQoS);
} catch (IOException e) {
throw new MQTTProtocolException("Failed while intercepting subscribe", true, e);
}
}
@Override
public void onReSubscribe(MQTTSubscription mqttSubscription) throws MQTTProtocolException {
String topicName = mqttSubscription.getTopicName();
// get TopicRegion
RegionBroker regionBroker;
try {
regionBroker = (RegionBroker) brokerService.getBroker().getAdaptor(RegionBroker.class);
} catch (Exception e) {
throw new MQTTProtocolException("Error subscribing to " + topicName + ": " + e.getMessage(), false, e);
}
final TopicRegion topicRegion = (TopicRegion) regionBroker.getTopicRegion();
final ConsumerInfo consumerInfo = mqttSubscription.getConsumerInfo();
final ConsumerId consumerId = consumerInfo.getConsumerId();
// use actual client id used to create connection to lookup connection
// context
String connectionInfoClientId = protocol.getClientId();
// for zero-byte client ids we used connection id
if (connectionInfoClientId == null || connectionInfoClientId.isEmpty()) {
connectionInfoClientId = protocol.getConnectionId().toString();
}
final ConnectionContext connectionContext = regionBroker.getConnectionContext(connectionInfoClientId);
// get all matching Topics
final Set<org.apache.activemq.broker.region.Destination> matchingDestinations =
topicRegion.getDestinations(mqttSubscription.getDestination());
for (org.apache.activemq.broker.region.Destination dest : matchingDestinations) {
// recover retroactive messages for matching subscription
for (Subscription subscription : dest.getConsumers()) {
if (subscription.getConsumerInfo().getConsumerId().equals(consumerId)) {
try {
if (dest instanceof org.apache.activemq.broker.region.Topic) {
((org.apache.activemq.broker.region.Topic) dest).recoverRetroactiveMessages(connectionContext, subscription);
} else if (dest instanceof VirtualTopicInterceptor) {
((VirtualTopicInterceptor) dest).getTopic().recoverRetroactiveMessages(connectionContext, subscription);
}
if (subscription instanceof PrefetchSubscription) {
// request dispatch for prefetch subs
PrefetchSubscription prefetchSubscription = (PrefetchSubscription) subscription;
prefetchSubscription.dispatchPending();
}
} catch (Exception e) {
throw new MQTTProtocolException("Error recovering retained messages for " + dest.getName() + ": " + e.getMessage(), false, e);
}
break;
}
}
}
}
@Override
public ActiveMQDestination onSend(String topicName) {
return new ActiveMQTopic(topicName);
}
@Override
public String onSend(ActiveMQDestination destination) {
return destination.getPhysicalName();
}
@Override
public boolean isControlTopic(ActiveMQDestination destination) {
return destination.getPhysicalName().startsWith("$");
}
@Override
public MQTTSubscription getSubscription(ConsumerId consumerId) {
return subscriptionsByConsumerId.get(consumerId);
}
protected ConsumerId getNextConsumerId() {
return new ConsumerId(protocol.getSessionId(), consumerIdGenerator.getNextSequenceId());
}
protected byte doSubscribe(ConsumerInfo consumerInfo, final String topicName, final QoS qoS) throws MQTTProtocolException {
MQTTSubscription mqttSubscription = new MQTTSubscription(protocol, topicName, qoS, consumerInfo);
// optimistic add to local maps first to be able to handle commands in onActiveMQCommand
subscriptionsByConsumerId.put(consumerInfo.getConsumerId(), mqttSubscription);
mqttSubscriptionByTopic.put(topicName, mqttSubscription);
final byte[] qos = {-1};
protocol.sendToActiveMQ(consumerInfo, new ResponseHandler() {
@Override
public void onResponse(MQTTProtocolConverter converter, Response response) throws IOException {
// validate subscription request
if (response.isException()) {
final Throwable throwable = ((ExceptionResponse) response).getException();
LOG.warn("Error subscribing to {}", topicName, throwable);
// version 3.1 don't supports silent fail
// version 3.1.1 send "error" qos
if (protocol.version == MQTTProtocolConverter.V3_1_1) {
qos[0] = SUBSCRIBE_ERROR;
} else {
qos[0] = (byte) qoS.ordinal();
}
} else {
qos[0] = (byte) qoS.ordinal();
}
}
});
if (qos[0] == SUBSCRIBE_ERROR) {
// remove from local maps if subscribe failed
subscriptionsByConsumerId.remove(consumerInfo.getConsumerId());
mqttSubscriptionByTopic.remove(topicName);
}
return qos[0];
}
public void doUnSubscribe(MQTTSubscription subscription) {
mqttSubscriptionByTopic.remove(subscription.getTopicName());
ConsumerInfo info = subscription.getConsumerInfo();
if (info != null) {
subscriptionsByConsumerId.remove(info.getConsumerId());
RemoveInfo removeInfo = info.createRemoveCommand();
protocol.sendToActiveMQ(removeInfo, new ResponseHandler() {
@Override
public void onResponse(MQTTProtocolConverter converter, Response response) throws IOException {
// ignore failures..
}
});
}
}
//----- Durable Subscription management methods --------------------------//
protected void deleteDurableSubs(List<SubscriptionInfo> subs) {
try {
for (SubscriptionInfo sub : subs) {
RemoveSubscriptionInfo rsi = new RemoveSubscriptionInfo();
rsi.setConnectionId(protocol.getConnectionId());
rsi.setSubscriptionName(sub.getSubcriptionName());
rsi.setClientId(sub.getClientId());
protocol.sendToActiveMQ(rsi, new ResponseHandler() {
@Override
public void onResponse(MQTTProtocolConverter converter, Response response) throws IOException {
// ignore failures..
}
});
}
} catch (Throwable e) {
LOG.warn("Could not delete the MQTT durable subs.", e);
}
}
protected void restoreDurableSubs(List<SubscriptionInfo> subs) {
try {
for (SubscriptionInfo sub : subs) {
String name = sub.getSubcriptionName();
String[] split = name.split(":", 2);
QoS qoS = QoS.valueOf(split[0]);
onSubscribe(new Topic(split[1], qoS));
// mark this durable subscription as restored by Broker
restoredDurableSubs.add(MQTTProtocolSupport.convertMQTTToActiveMQ(split[1]));
}
} catch (IOException e) {
LOG.warn("Could not restore the MQTT durable subs.", e);
}
}
protected List<SubscriptionInfo> lookupSubscription(String clientId) throws MQTTProtocolException {
List<SubscriptionInfo> result = new ArrayList<SubscriptionInfo>();
RegionBroker regionBroker;
try {
regionBroker = (RegionBroker) brokerService.getBroker().getAdaptor(RegionBroker.class);
} catch (Exception e) {
throw new MQTTProtocolException("Error recovering durable subscriptions: " + e.getMessage(), false, e);
}
final TopicRegion topicRegion = (TopicRegion) regionBroker.getTopicRegion();
List<DurableTopicSubscription> subscriptions = topicRegion.lookupSubscriptions(clientId);
if (subscriptions != null) {
for (DurableTopicSubscription subscription : subscriptions) {
LOG.debug("Recovered durable sub:{} on connect", subscription);
SubscriptionInfo info = new SubscriptionInfo();
info.setDestination(subscription.getActiveMQDestination());
info.setSubcriptionName(subscription.getSubscriptionKey().getSubscriptionName());
info.setClientId(clientId);
result.add(info);
}
}
return result;
}
}