org.apache.hadoop.hbase.util

Class WindowMovingAverage

java.lang.Object

org.apache.hadoop.hbase.util.MovingAverage

org.apache.hadoop.hbase.util.WindowMovingAverage

Direct Known Subclasses:

ExponentialMovingAverage, WeightedMovingAverage

@InterfaceAudience.Private
public class WindowMovingAverage
extends MovingAverage

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 and Description
protected static 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 and Description
WindowMovingAverage(String label)
WindowMovingAverage(String label, int size)

Method Summary

Modifier and Type	Method and Description
protected boolean	enoughStatistics() Check if there are enough statistics.
double	getAverageTime() Get average execution time of the measured method.
protected int	getMostRecentPosistion()
protected int	getNumberOfStatistics()
protected long	getStatisticsAtIndex(int index) Get statistics at index.
protected int	moveForwardMostRecentPosistion() 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 Detail

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 Detail

WindowMovingAverage

public WindowMovingAverage(String label)

WindowMovingAverage

public WindowMovingAverage(String label,
                           int size)

Method Detail

updateMostRecentTime

protected void updateMostRecentTime(long elapsed)

Description copied from class: MovingAverage

Update the most recent data.

Specified by:

updateMostRecentTime in class MovingAverage

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

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

Returns:

statistics

getMostRecentPosistion

protected int getMostRecentPosistion()

Returns:

index of most recent

moveForwardMostRecentPosistion

protected int moveForwardMostRecentPosistion()

Move forward the most recent index.

Returns:

the most recent index

sum

private long sum(int bound)