Package org.apache.activemq.artemis.core.server.impl

Class LastValueQueue

java.lang.Object

org.apache.activemq.artemis.utils.critical.CriticalComponentImpl

org.apache.activemq.artemis.core.server.impl.QueueImpl

org.apache.activemq.artemis.core.server.impl.LastValueQueue

All Implemented Interfaces:

Bindable, Queue, CriticalComponent

public class LastValueQueue
extends QueueImpl

A queue that will discard messages if a newer message with the same Message.HDR_LAST_VALUE_NAME property value. In other words it only retains the last value

This is useful for example, for stock prices, where you're only interested in the latest value for a particular stock

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.activemq.artemis.core.server.impl.QueueImpl

QueueImpl.ConsumerHolder<T extends Consumer>

Field Summary

Fields inherited from class org.apache.activemq.artemis.core.server.impl.QueueImpl

CHECK_QUEUE_SIZE_PERIOD, CRITICAL_CHECK_DEPAGE, CRITICAL_CONSUMER, CRITICAL_DELIVER, CRITICAL_PATH_ADD_HEAD, CRITICAL_PATH_ADD_TAIL, CRITICAL_PATHS, DEFAULT_FLUSH_LIMIT, DELIVERY_TIMEOUT, dispatching, dispatchStartTime, MAX_DELIVERIES_IN_LOOP, messageReferences, NUM_PRIORITIES, pageSubscription, pendingMetrics, queueConfiguration, scheduledDeliveryHandler

Fields inherited from interface org.apache.activemq.artemis.core.server.Queue

MAX_CONSUMERS_UNLIMITED

Constructor Summary

Constructors

Constructor	Description
LastValueQueue(QueueConfiguration queueConfiguration, Filter filter, PagingStore pagingStore, PageSubscription pageSubscription, ScheduledExecutorService scheduledExecutor, PostOffice postOffice, StorageManager storageManager, HierarchicalRepository<AddressSettings> addressSettingsRepository, ArtemisExecutor executor, ActiveMQServer server, QueueFactory factory)

Method Summary

Modifier and Type	Method	Description
void	acknowledge(MessageReference ref, AckReason reason, ServerConsumer consumer)
void	acknowledge(Transaction tx, MessageReference ref, AckReason reason, ServerConsumer consumer, boolean delivering)	The parameter delivering can be sent as false in situation where the ack is coming outside of the context of delivering.
void	addHead(MessageReference ref, boolean scheduling)
void	addSorted(MessageReference ref, boolean scheduling)	Called when a message is cancelled back into the queue
void	addTail(MessageReference ref, boolean direct)
boolean	allowsReferenceCallback()	the current queue and consumer settings will allow use of the Reference Execution and callback.
boolean	equals(Object obj)
Set<SimpleString>	getLastValueKeys()
long	getMessageCount()
int	hashCode()
protected void	pruneLastValues()
protected void	refRemoved(MessageReference ref)
void	reload(MessageReference newRef)

Methods inherited from class org.apache.activemq.artemis.core.server.impl.QueueImpl

acknowledge, acknowledge, acknowledge, addConsumer, addHead, addLingerSession, addRedistributor, addRefSize, addSorted, addTail, browserIterator, cancel, cancel, cancel, cancelRedistributor, changeReferencePriority, changeReferencesPriority, checkRedelivery, close, copyReference, debug, decDelivering, deleteAllReferences, deleteAllReferences, deleteMatchingReferences, deleteMatchingReferences, deleteQueue, deleteQueue, deleteReference, deliverAsync, deliverNow, deliverScheduledMessage, deliverScheduledMessages, deliverScheduledMessages, destroyPaging, durableDown, durableUp, errorProcessing, expire, expire, expireReference, expireReferences, expireReferences, flushExecutor, flushOnIntermediate, forceDelivery, getAcknowledgeAttempts, getAddress, getAutoDeleteDelay, getAutoDeleteMessageCount, getConsumerCount, getConsumerRemovedTimestamp, getConsumers, getConsumersBeforeDispatch, getConsumersRefCount, getCreatedTimestamp, getDeadLetterAddress, getDelayBeforeDispatch, getDeliveringCount, getDeliveringMessages, getDeliveringSize, getDispatchStartTime, getDurableDeliveringCount, getDurableDeliveringSize, getDurableMessageCount, getDurablePersistentSize, getDurableScheduledCount, getDurableScheduledSize, getExecutor, getExpiryAddress, getFilter, getGroupBuckets, getGroupCount, getGroupFirstKey, getGroups, getID, getInitialQueueBufferSize, getLastValueKey, getMaxConsumers, getMessagesAcknowledged, getMessagesAdded, getMessagesExpired, getMessagesKilled, getMessagesReplaced, getName, getNumberOfReferences, getPageSubscription, getPagingStore, getPendingMessageCount, getPersistentSize, getQueueConfiguration, getRedistributor, getRingSize, getRoutingName, getRoutingType, getScheduledCount, getScheduledMessages, getScheduledSize, getUniqueName, getUser, groupMap, hasMatchingConsumer, incDelivering, incrementMesssagesAdded, isAutoCreated, isAutoDelete, isConfigurationManaged, isDirectDeliver, isDispatching, isDurable, isDurableMessage, isEnabled, isExclusive, isGroupRebalance, isGroupRebalancePauseDispatch, isInternalQueue, isLastValue, isMirrorController, isNonDestructive, isPaused, isPersistedPause, isPurgeOnNoConsumers, isSwept, isTemporary, iterator, moveReference, moveReferences, moveReferences, moveReferences, moveReferencesBetweenSnFQueues, pause, pause, peekFirstMessage, peekFirstScheduledMessage, postAcknowledge, postAcknowledge, reacknowledge, recheckRefCount, refAdded, refDown, referenceHandled, refUp, reloadPause, reloadSequence, removeAddress, removeConsumer, removeLingerSession, removeMessageReference, removeReferenceWithID, removeWithSuppliedID, rerouteMessages, resetAllGroups, resetAllIterators, resetGroup, resetMessagesAcknowledged, resetMessagesAdded, resetMessagesExpired, resetMessagesKilled, resume, retryMessages, retryMessages, route, routeWithAck, scheduleIfPossible, sendMessagesToDeadLetterAddress, sendMessageToDeadLetterAddress, sendToDeadLetterAddress, setConfigurationManaged, setConsumersBeforeDispatch, setDelayBeforeDispatch, setDispatching, setEnabled, setExclusive, setFilter, setGroupBuckets, setGroupFirstKey, setGroupRebalance, setGroupRebalancePauseDispatch, setInternalQueue, setMaxConsumer, setMirrorController, setNonDestructive, setPurgeOnNoConsumers, setRingSize, setRoutingType, setSwept, setUser, toString, unproposed

Methods inherited from class org.apache.activemq.artemis.utils.critical.CriticalComponentImpl

checkExpiration, getCriticalAnalyzer, measureCritical

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.activemq.artemis.utils.critical.CriticalComponent

checkExpiration, getCriticalAnalyzer, measureCritical

Methods inherited from interface org.apache.activemq.artemis.core.server.Queue

deleteMatchingReferences, expireReferences, forEach

Constructor Details

LastValueQueue

public LastValueQueue(QueueConfiguration queueConfiguration,
 Filter filter,
 PagingStore pagingStore,
 PageSubscription pageSubscription,
 ScheduledExecutorService scheduledExecutor,
 PostOffice postOffice,
 StorageManager storageManager,
 HierarchicalRepository<AddressSettings> addressSettingsRepository,
 ArtemisExecutor executor,
 ActiveMQServer server,
 QueueFactory factory)

Method Details

addTail

public void addTail(MessageReference ref,
 boolean direct)

Specified by:

addTail in interface Queue

Overrides:

addTail in class QueueImpl

addHead

public void addHead(MessageReference ref,
 boolean scheduling)

Specified by:

addHead in interface Queue

Overrides:

addHead in class QueueImpl

addSorted

public void addSorted(MessageReference ref,
 boolean scheduling)

Description copied from interface: Queue

Called when a message is cancelled back into the queue

Specified by:

addSorted in interface Queue

Overrides:

addSorted in class QueueImpl

getMessageCount

public long getMessageCount()

Specified by:

getMessageCount in interface Queue

Overrides:

getMessageCount in class QueueImpl

allowsReferenceCallback

public boolean allowsReferenceCallback()

Description copied from interface: Queue

the current queue and consumer settings will allow use of the Reference Execution and callback. This is because

Specified by:

allowsReferenceCallback in interface Queue

Overrides:

allowsReferenceCallback in class QueueImpl

pruneLastValues

protected void pruneLastValues()

Overrides:

pruneLastValues in class QueueImpl

refRemoved

protected void refRemoved(MessageReference ref)

Overrides:

refRemoved in class QueueImpl

acknowledge

public void acknowledge(MessageReference ref,
 AckReason reason,
 ServerConsumer consumer)
                 throws Exception

Specified by:

acknowledge in interface Queue

Overrides:

acknowledge in class QueueImpl

Throws:

Exception

acknowledge

public void acknowledge(Transaction tx,
 MessageReference ref,
 AckReason reason,
 ServerConsumer consumer,
 boolean delivering)
                 throws Exception

Description copied from class: QueueImpl

The parameter delivering can be sent as false in situation where the ack is coming outside of the context of delivering. Example: Mirror replication will call the ack here without any consumer involved. On that case no previous delivery happened, hence no information about delivering statistics should be updated.

Specified by:

acknowledge in interface Queue

Overrides:

acknowledge in class QueueImpl

Throws:

Exception

reload

public void reload(MessageReference newRef)

Specified by:

reload in interface Queue

Overrides:

reload in class QueueImpl

getLastValueKeys

public Set<SimpleString> getLastValueKeys()

hashCode

public int hashCode()

Overrides:

hashCode in class QueueImpl

equals

public boolean equals(Object obj)

Overrides:

equals in class QueueImpl