Package org.apache.hadoop.hbase.util

Class WindowMovingAverage<T>

java.lang.Object

org.apache.hadoop.hbase.util.MovingAverage<T>

org.apache.hadoop.hbase.util.WindowMovingAverage<T>

Direct Known Subclasses:

ExponentialMovingAverage, WeightedMovingAverage

@Private
public class WindowMovingAverage<T>
extends MovingAverage<T>

Instead of calculate a whole time average, this class focus on the last N. The last N is stored in a circle array.

Field Summary

Fields

Modifier and Type	Field	Description
protected static final int	DEFAULT_SIZE
protected long[]	lastN
protected int	mostRecent
protected boolean	oneRound

Fields inherited from class org.apache.hadoop.hbase.util.MovingAverage

label

Constructor Summary

Constructors

Constructor	Description
WindowMovingAverage(String label)
WindowMovingAverage(String label, int size)

Method Summary

Modifier and Type	Method	Description
protected boolean	enoughStatistics()	Check if there are enough statistics.
double	getAverageTime()	Get average execution time of the measured method.
protected int	getMostRecentPosition()	Returns index of most recent
protected int	getNumberOfStatistics()	Returns number of statistics
protected long	getStatisticsAtIndex(int index)	Get statistics at index.
protected int	moveForwardMostRecentPosition()	Move forward the most recent index.
private long	sum(int bound)
protected void	updateMostRecentTime(long elapsed)	Update the most recent data.

Methods inherited from class org.apache.hadoop.hbase.util.MovingAverage

measure, start, stop

Methods inherited from class java.lang.Object

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

Field Details

DEFAULT_SIZE

protected static final int DEFAULT_SIZE

See Also:

• Constant Field Values

lastN

protected long[] lastN

mostRecent

protected int mostRecent

oneRound

protected boolean oneRound

Constructor Details

WindowMovingAverage

public WindowMovingAverage(String label)

WindowMovingAverage

public WindowMovingAverage(String label,
 int size)

Method Details

updateMostRecentTime

protected void updateMostRecentTime(long elapsed)

Description copied from class: MovingAverage

Update the most recent data.

Specified by:

updateMostRecentTime in class MovingAverage<T>

Parameters:

elapsed - elapsed time of the most recent measurement

getAverageTime

public double getAverageTime()

Description copied from class: MovingAverage

Get average execution time of the measured method.

Specified by:

getAverageTime in class MovingAverage<T>

Returns:

average time in ns

enoughStatistics

protected boolean enoughStatistics()

Check if there are enough statistics.

Returns:

true if lastN is full

getNumberOfStatistics

protected int getNumberOfStatistics()

Returns number of statistics

getStatisticsAtIndex

protected long getStatisticsAtIndex(int index)

Get statistics at index.

Parameters:

index - index of bar

getMostRecentPosition

protected int getMostRecentPosition()

Returns index of most recent

moveForwardMostRecentPosition

protected int moveForwardMostRecentPosition()

Move forward the most recent index.

Returns:

the most recent index

sum

private long sum(int bound)