org.nuxeo.runtime.pubsub

Class AbstractPubSubBroker<T extends SerializableMessage>

java.lang.Object

org.nuxeo.runtime.pubsub.AbstractPubSubBroker<T>

Direct Known Subclasses:

AbstractPubSubInvalidationsAccumulator, CacheServiceImpl.AbstractCachePubSubInvalidator, MigrationServiceImpl.MigrationInvalidator, WOPIServiceImpl.WOPIDiscoveryInvalidator

public abstract class AbstractPubSubBroker<T extends SerializableMessage>
extends Object

Encapsulates message sending and receiving through the PubSubService.

All nodes that use the same topic will receive the same messages. The discriminator is used to distinguish nodes between one another, and to avoid that a node receives the messages it send itself.

An actual implementation must implement the method deserialize(java.io.InputStream) (usually by delegating to a static method in the T message class), and the receivedMessage(T) callback.

The public API is sendMessage(T), and the receivedMessage(T) callback.

Since:

9.3

Field Summary

Fields

Modifier and Type	Field and Description
protected static byte	DISCRIMINATOR_SEP
protected byte[]	discriminatorBytes
protected String	topic

Constructor Summary

Constructors

Constructor and Description
AbstractPubSubBroker()

Method Summary

Modifier and Type	Method and Description
void	close() Closes this broker and releases resources.
abstract T	deserialize(InputStream in) Deserializes an InputStream into a message, or null.
void	initialize(String topic, String discriminator) Initializes the broker.
abstract void	receivedMessage(T message) Callback implementing the delivery of a message from another node.
protected int	scanDiscriminator(byte[] message) Scans for the discriminator and returns the payload start offset.
void	sendMessage(T message) Sends a message to other nodes.
protected void	subscriber(String topic, byte[] bytes) PubSubService subscriber, called from a separate thread.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

topic

protected String topic

discriminatorBytes

protected byte[] discriminatorBytes

DISCRIMINATOR_SEP

protected static final byte DISCRIMINATOR_SEP

See Also:

Constant Field Values

Constructor Detail

AbstractPubSubBroker

public AbstractPubSubBroker()

Method Detail

deserialize

public abstract T deserialize(InputStream in)
                       throws IOException

Deserializes an InputStream into a message, or null.

Throws:

IOException

initialize

public void initialize(String topic,
                       String discriminator)

Initializes the broker.

Parameters:

topic - the topic

discriminator - the discriminator

close

public void close()

Closes this broker and releases resources.

sendMessage

public void sendMessage(T message)

Sends a message to other nodes.

subscriber

protected void subscriber(String topic,
                          byte[] bytes)

PubSubService subscriber, called from a separate thread.

receivedMessage

public abstract void receivedMessage(T message)

Callback implementing the delivery of a message from another node.

Parameters:

message - the received message

scanDiscriminator

protected int scanDiscriminator(byte[] message)

Scans for the discriminator and returns the payload start offset.

Returns:

payload start offset, or -1 if the discriminator is local or if the message is invalid