/**
* A PUBLISH Control Packet is sent from a Client to a Server or from Server to a Client to
* transport an Application Message.
*
* @throws RetriableException
* @throws UnRetriableException
*/
@Override
public void handle(PublishMessage publishMessage)
throws RetriableException, UnRetriableException {
log.debug(" handle : client attempting to publish a message.");
/**
* During an attempt to publish a message.
*
* <p>All Topic Names and Topic Filters MUST be at least one character long [MQTT-4.7.3-1]
*
* <p>The wildcard characters can be used in Topic Filters, but MUST NOT be used within a Topic
* Name [MQTT-4.7.1-1].
*
* <p>Topic Names and Topic Filters MUST NOT include the null character (Unicode U+0000)
* [Unicode] [MQTT-4.7.3-2]
*
* <p>Topic Names and Topic Filters are UTF-8 encoded strings, they MUST NOT encode to more than
* 65535 bytes [MQTT-4.7.3-3]. See Section 1.5.3
*/
String topic = publishMessage.getTopic();
if (null == topic
|| topic.isEmpty()
|| topic.contains(Constant.MULTI_LEVEL_WILDCARD)
|| topic.contains(Constant.SINGLE_LEVEL_WILDCARD)
|| topic.contains(Constant.SYS_PREFIX)) {
log.info(" handle : Invalid topic " + publishMessage.getTopic());
throw new ShutdownException(" Invalid topic name");
}
/** Before publishing we should get the current session and validate it. */
Observable<IOTClient> permissionObservable =
checkPermission(
publishMessage.getSessionId(),
publishMessage.getAuthKey(),
AuthorityRole.PUBLISH,
topic);
permissionObservable.subscribe(
(iotSession) -> {
try {
publishMessage.setPartitionId(iotSession.getPartitionId());
publishMessage.setClientId(iotSession.getSessionId());
publishMessage.setId(-1);
/** Message processing is based on 4.3 Quality of Service levels and protocol flows */
/**
* 4.3.1 QoS 0: At most once delivery Accepts ownership of the message when it receives
* the PUBLISH packet.
*/
if (MqttQoS.AT_MOST_ONCE.value() == publishMessage.getQos()) {
getMessenger().publish(iotSession.getPartitionId(), publishMessage);
}
/**
* 4.3.2 QoS 1: At least once delivery
*
* <p>MUST respond with a PUBACK Packet containing the Packet Identifier from the
* incoming PUBLISH Packet, having accepted ownership of the Application Message After
* it has sent a PUBACK Packet the Receiver MUST treat any incoming PUBLISH packet that
* contains the same Packet Identifier as being a new publication, irrespective of the
* setting of its DUP flag.
*/
if (MqttQoS.AT_LEAST_ONCE.value() == publishMessage.getQos()) {
getMessenger().publish(iotSession.getPartitionId(), publishMessage);
// We need to generate a puback message to close this conversation.
AcknowledgeMessage acknowledgeMessage =
AcknowledgeMessage.from(publishMessage.getMessageId());
acknowledgeMessage.copyTransmissionData(publishMessage);
pushToServer(acknowledgeMessage);
}
/**
* 4.3.3 QoS 2: Exactly once delivery
*
* <p>MUST respond with a PUBREC containing the Packet Identifier from the incoming
* PUBLISH Packet, having accepted ownership of the Application Message. Until it has
* received the corresponding PUBREL packet, the Receiver MUST acknowledge any
* subsequent PUBLISH packet with the same Packet Identifier by sending a PUBREC. It
* MUST NOT cause duplicate messages to be delivered to any onward recipients in this
* case.
*/
if (MqttQoS.EXACTLY_ONCE.value() == publishMessage.getQos()) {
queueQos2Message(publishMessage);
}
} catch (UnRetriableException | RetriableException e) {
disconnectDueToError(e, publishMessage);
}
},
throwable -> disconnectDueToError(throwable, publishMessage));
}
/**
* Provides the Observer with a new item to observe.
*
* <p>The {@link com.caricah.iotracah.core.modules.Server} may call this method 0 or more times.
*
* <p>The {@code Observable} will not call this method again after it calls either {@link
* #onCompleted} or {@link #onError}.
*
* @param iotMessage the item emitted by the Observable
*/
@Override
public void onNext(IOTMessage iotMessage) {
getExecutorService()
.submit(
() -> {
log.info(" onNext : received {}", iotMessage);
try {
IOTMessage response = null;
switch (iotMessage.getMessageType()) {
case ConnectMessage.MESSAGE_TYPE:
ConnectMessage connectMessage = (ConnectMessage) iotMessage;
response =
ConnectAcknowledgeMessage.from(
connectMessage.isDup(),
connectMessage.getQos(),
connectMessage.isRetain(),
connectMessage.getKeepAliveTime(),
MqttConnectReturnCode.CONNECTION_ACCEPTED);
break;
case SubscribeMessage.MESSAGE_TYPE:
SubscribeMessage subscribeMessage = (SubscribeMessage) iotMessage;
List<Integer> grantedQos = new ArrayList<>();
subscribeMessage
.getTopicFilterList()
.forEach(
topic -> {
String topicKey =
quickCheckIdKey(
"",
Arrays.asList(topic.getKey().split(Constant.PATH_SEPARATOR)));
Set<String> channelIds = subscriptions.get(topicKey);
if (Objects.isNull(channelIds)) {
channelIds = new HashSet<>();
}
channelIds.add(subscribeMessage.getConnectionId());
subscriptions.put(topicKey, channelIds);
grantedQos.add(topic.getValue());
});
response =
SubscribeAcknowledgeMessage.from(
subscribeMessage.getMessageId(), grantedQos);
break;
case UnSubscribeMessage.MESSAGE_TYPE:
UnSubscribeMessage unSubscribeMessage = (UnSubscribeMessage) iotMessage;
response =
UnSubscribeAcknowledgeMessage.from(unSubscribeMessage.getMessageId());
break;
case Ping.MESSAGE_TYPE:
response = iotMessage;
break;
case PublishMessage.MESSAGE_TYPE:
PublishMessage publishMessage = (PublishMessage) iotMessage;
Set<String> matchingTopics =
getMatchingSubscriptions("", publishMessage.getTopic());
for (String match : matchingTopics) {
Set<String> channelIds = subscriptions.get(match);
if (Objects.nonNull(channelIds)) {
channelIds.forEach(
id -> {
PublishMessage clonePublishMessage = publishMessage.cloneMessage();
clonePublishMessage.copyTransmissionData(iotMessage);
clonePublishMessage.setConnectionId(id);
pushToServer(clonePublishMessage);
});
}
}
if (MqttQoS.AT_MOST_ONCE.value() == publishMessage.getQos()) {
break;
} else if (MqttQoS.AT_LEAST_ONCE.value() == publishMessage.getQos()) {
response = AcknowledgeMessage.from(publishMessage.getMessageId());
break;
}
case PublishReceivedMessage.MESSAGE_TYPE:
case ReleaseMessage.MESSAGE_TYPE:
case CompleteMessage.MESSAGE_TYPE:
case DisconnectMessage.MESSAGE_TYPE:
case AcknowledgeMessage.MESSAGE_TYPE:
default:
DisconnectMessage disconnectMessage = DisconnectMessage.from(true);
disconnectMessage.copyTransmissionData(iotMessage);
throw new ShutdownException(disconnectMessage);
}
if (Objects.nonNull(response)) {
response.copyTransmissionData(iotMessage);
pushToServer(response);
}
} catch (ShutdownException e) {
IOTMessage response = e.getResponse();
if (Objects.nonNull(response)) {
pushToServer(response);
}
} catch (Exception e) {
log.error(" onNext : Serious error that requires attention ", e);
}
});
}