mondrian.util
Class FauxMemoryMonitor

java.lang.Object
  mondrian.util.FauxMemoryMonitor

All Implemented Interfaces:

MemoryMonitor

public class FauxMemoryMonitor
extends Object
implements MemoryMonitor

The FauxMemoryMonitor implements the MemoryMonitor interface but does nothing: all methods are empty.

Since:

Feb 03 2007

Author:

Richard M. Emberson

Nested Class Summary

Nested classes/interfaces inherited from interface mondrian.util.MemoryMonitor

MemoryMonitor.Listener, MemoryMonitor.Test

Constructor Summary

FauxMemoryMonitor()

Method Summary

boolean	addListener(MemoryMonitor.Listener listener) Adds a Listener using the default threshold percentage.
boolean	addListener(MemoryMonitor.Listener listener, int thresholdPercentage) Adds a Listener to the MemoryMonitor with a given threshold percentage.
long	getMaxMemory() Returns the maximum memory usage.
long	getUsedMemory() Returns the current memory used.
void	removeAllListener() Clear out all Listeners and turnoff JVM memory notification.
boolean	removeListener(MemoryMonitor.Listener listener) Removes a Listener from the MemoryMonitor.
void	updateListenerThreshold(MemoryMonitor.Listener listener, int percentage) Changes the threshold percentage of a given Listener.

Methods inherited from class java.lang.Object

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

Constructor Detail

FauxMemoryMonitor

FauxMemoryMonitor()

Method Detail

addListener

public boolean addListener(MemoryMonitor.Listener listener,
                           int thresholdPercentage)

Description copied from interface: MemoryMonitor

Adds a Listener to the MemoryMonitor with a given threshold percentage.

If the threshold is below the Java5 memory managment system's threshold, then the Listener is notified from within this method.

Specified by:

addListener in interface MemoryMonitor

Parameters:

listener - the Listener to be added.

thresholdPercentage - the threshold percentage for this Listener.

Returns:

true if the Listener was added and false otherwise.

addListener

public boolean addListener(MemoryMonitor.Listener listener)

Description copied from interface: MemoryMonitor

Adds a Listener using the default threshold percentage.

If the threshold is below the Java5 memory managment system's threshold, then the Listener is notified from within this method.

Specified by:

addListener in interface MemoryMonitor

Parameters:

listener - the Listener to be added.

Returns:

true if the Listener was added and false otherwise.

updateListenerThreshold

public void updateListenerThreshold(MemoryMonitor.Listener listener,
                                    int percentage)

Description copied from interface: MemoryMonitor

Changes the threshold percentage of a given Listener.

If the new value is below the system's current value, then the Listener will have its notification callback called while in this method - so a client should always check if its notification method was called immediately after calling this method.

This method can be used if, for example, an algorithm has different approaches that result in different memory usage profiles; one, large memory but fast and a second which is low-memory but slow. The algorithm starts with the large memory approach, receives a low memory notification, switches to the low memory approach and changes when it should be notified for this new approach. The first approach need to be notified at a lower percentage because it uses lots of memory, possibly quickly; while the second approach, possibly a file based algorithm, has smaller memory requirements and uses memory less quickly thus one can live with a higher notification threshold percentage.

Specified by:

updateListenerThreshold in interface MemoryMonitor

Parameters:

listener - the Listener being updated.

percentage - new percentage threshold.

removeListener

public boolean removeListener(MemoryMonitor.Listener listener)

Description copied from interface: MemoryMonitor

Removes a Listener from the MemoryMonitor. Returns true if listener was removed and false otherwise.

Specified by:

removeListener in interface MemoryMonitor

Parameters:

listener - the listener to be removed

Returns:

true if listener was removed.

removeAllListener

public void removeAllListener()

Description copied from interface: MemoryMonitor

Clear out all Listeners and turnoff JVM memory notification.

Specified by:

removeAllListener in interface MemoryMonitor

getMaxMemory

public long getMaxMemory()

Description copied from interface: MemoryMonitor

Returns the maximum memory usage.

Specified by:

getMaxMemory in interface MemoryMonitor

Returns:

the maximum memory usage.

getUsedMemory

public long getUsedMemory()

Description copied from interface: MemoryMonitor

Returns the current memory used.

Specified by:

getUsedMemory in interface MemoryMonitor

Returns:

the current memory used.