org.apache.ambari.server.agent.stomp

Class AgentClusterDataHolder<T extends STOMPEvent & Hashable>

java.lang.Object

org.apache.ambari.server.agent.stomp.AgentDataHolder<T>

org.apache.ambari.server.agent.stomp.AgentClusterDataHolder<T>

Type Parameters:

T - event with hash to control version

Direct Known Subclasses:

MetadataHolder, TopologyHolder

public abstract class AgentClusterDataHolder<T extends STOMPEvent & Hashable>
extends AgentDataHolder<T>

Is used to saving and updating last version of event in cluster scope

Field Summary

Fields

Modifier and Type	Field and Description
protected STOMPUpdatePublisher	STOMPUpdatePublisher

Fields inherited from class org.apache.ambari.server.agent.stomp.AgentDataHolder

updateLock

Constructor Summary

Constructors

Constructor and Description
AgentClusterDataHolder()

Method Summary

Modifier and Type	Method and Description
protected abstract T	getCurrentData() Builds an update with the full set of current data.
T	getData()
T	getUpdateIfChanged(String agentHash)
protected abstract boolean	handleUpdate(T update) Handle an incremental update to the data.
protected void	initializeDataIfNeeded(boolean regenerateHash)
boolean	updateData(T update) Template method to update the data.

Methods inherited from class org.apache.ambari.server.agent.stomp.AgentDataHolder

getEmptyData, getHash, getHash, isIdentifierValid, regenerateDataIdentifiers

Methods inherited from class java.lang.Object

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

Field Detail

STOMPUpdatePublisher

@Inject
protected STOMPUpdatePublisher STOMPUpdatePublisher

Constructor Detail

AgentClusterDataHolder

public AgentClusterDataHolder()

Method Detail

getUpdateIfChanged

public T getUpdateIfChanged(String agentHash)
                     throws org.apache.ambari.server.AmbariException

Throws:

org.apache.ambari.server.AmbariException

getCurrentData

protected abstract T getCurrentData()
                             throws org.apache.ambari.server.AmbariException

Builds an update with the full set of current data. The eventType should be "CREATE", if applicable.

Throws:

org.apache.ambari.server.AmbariException

handleUpdate

protected abstract boolean handleUpdate(T update)
                                 throws org.apache.ambari.server.AmbariException

Handle an incremental update to the data.

Returns:

true if the update introduced any change

Throws:

org.apache.ambari.server.AmbariException

updateData

public boolean updateData(T update)
                   throws org.apache.ambari.server.AmbariException

Template method to update the data.

Returns:

true if the update introduced any change

Throws:

org.apache.ambari.server.AmbariException

initializeDataIfNeeded

protected final void initializeDataIfNeeded(boolean regenerateHash)
                                     throws org.apache.ambari.server.AmbariException

Throws:

org.apache.ambari.server.AmbariException

getData

public final T getData()