Package com.illumon.iris.db.util

Class PrintListener

java.lang.Object

com.illumon.util.referencecounting.ReferenceCounted

com.illumon.iris.db.util.liveness.ReferenceCountedLivenessNode

com.illumon.iris.db.util.liveness.LivenessArtifact

com.illumon.iris.db.v2.InstrumentedListenerBase

com.illumon.iris.db.v2.InstrumentedShiftAwareListener

com.illumon.iris.db.util.PrintListener

All Implemented Interfaces:

com.fishlib.base.log.LogOutputAppendable, NotificationQueue.Dependency, LivenessManager, LivenessNode, LivenessReferent, ListenerBase, ShiftAwareListener, Serializable

@ScriptApi
public class PrintListener
extends InstrumentedShiftAwareListener

A simple listener that prints out each update received from a table.

This can be used to debug the performance of a query by attaching to various tables in an effort to understand the update pattern. Optionally, you can also print out the head of the table.

Output is directed to stdout, thus this should not be enabled in production queries.

After you are finished, call the stop() method to remove this listener from the source table.

See Also:

• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class com.illumon.iris.db.v2.InstrumentedShiftAwareListener

InstrumentedShiftAwareListener.Notification

Nested classes/interfaces inherited from class com.illumon.iris.db.v2.InstrumentedListenerBase

InstrumentedListenerBase.ErrorNotification, InstrumentedListenerBase.NotificationBase

Nested classes/interfaces inherited from interface com.illumon.iris.db.v2.ShiftAwareListener

ShiftAwareListener.Update

Constructor Summary

Constructors

Constructor	Description
PrintListener(String description, DynamicTable table)	Create a PrintListener attached to the given table.
PrintListener(String description, DynamicTable table, int rowCount)	Create a PrintListener attached to the given table.

Method Summary

Modifier and Type	Method	Description
void	onFailureInternal(Throwable originalException, UpdatePerformanceTracker.Entry sourceEntry)
void	onUpdate(ShiftAwareListener.Update upstream)	Process notification of table changes.
void	stop()	Remove this listener from the table.

Methods inherited from class com.illumon.iris.db.v2.InstrumentedShiftAwareListener

getNotification

Methods inherited from class com.illumon.iris.db.v2.InstrumentedListenerBase

append, canExecute, getEntry, getErrorNotification, onFailure, onFailureInternalWithDependent, satisfied, setVerboseLogging, toString

Methods inherited from class com.illumon.iris.db.util.liveness.LivenessArtifact

manageWithCurrentScope, unmanage, unmanage

Methods inherited from class com.illumon.iris.db.util.liveness.ReferenceCountedLivenessNode

destroy, dropReference, getWeakReference, initializeTransientFieldsForLiveness, onReferenceCountAtZero, tryManage, tryRetainReference

Methods inherited from class com.illumon.util.referencecounting.ReferenceCounted

decrementReferenceCount, incrementReferenceCount, resetReferenceCount, tryDecrementReferenceCount, tryIncrementReferenceCount

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.illumon.iris.db.v2.ListenerBase

getErrorNotification, onFailure

Methods inherited from interface com.illumon.iris.db.util.liveness.LivenessManager

manage, tryManage

Methods inherited from interface com.illumon.iris.db.util.liveness.LivenessReferent

dropReference, getReferentDescription, getWeakReference, retainReference, tryRetainReference

Constructor Details

PrintListener

@ScriptApi
public PrintListener(String description,
 DynamicTable table)

Create a PrintListener attached to the given table. Note that this automatically listens to the source table.

Parameters:

description - the description (for use in each print statement)

table - the table to attach to

PrintListener

@ScriptApi
public PrintListener(String description,
 DynamicTable table,
 int rowCount)

Create a PrintListener attached to the given table. Note that this automatically listens to the source table.

Parameters:

description - the description (for use in each print statement)

table - the table to attach to

rowCount - how many rows to print out on each update

Method Details

onUpdate

public void onUpdate(ShiftAwareListener.Update upstream)

Description copied from interface: ShiftAwareListener

Process notification of table changes.

The Listener onUpdate call executes within the LiveTableMonitor refresh loop. Any tables used within the listener's onUpdate call must have already been refreshed. Using the typical pattern of a Listener that is listening to a single table, with DynamicTable.listenForUpdates(Listener), this is trivially true.

When the listener must reference more than just one parent, the tables (or other objects) it references, must be made a NotificationQueue.Dependency of the listener. For listeners that reference multiple ticking tables, a common pattern is to use a MergedListener and collection of ListenerRecorders.

Parameters:

upstream - The set of upstream table updates.

onFailureInternal

public void onFailureInternal(Throwable originalException,
 UpdatePerformanceTracker.Entry sourceEntry)

Specified by:

onFailureInternal in class InstrumentedListenerBase

stop

public void stop()

Remove this listener from the table.