org.javasimon
Class NullStopwatch

java.lang.Object
  org.javasimon.NullSimon
      org.javasimon.NullStopwatch

All Implemented Interfaces:

HasAttributes, Simon, Stopwatch

final class NullStopwatch
extends NullSimon
implements Stopwatch

Null Stopwatch implements Simon returned by the disabled Manager.getStopwatch(String). It extends NullSimon to satisfy Stopwatch interface.

Author:

Richard "Virgo" Richter

Field Summary

(package private) static NullStopwatch	INSTANCE Internal singleton value of the null Stopwatch.
private static Split	NULL_SPLIT

Constructor Summary

private

NullStopwatch()

Method Summary

Stopwatch	addSplit(Split split) Adds Split to the stopwatch which is useful for aggregation of splits created for other stopwatch.
Stopwatch	addTime(long ns) Adds split time in nanoseconds to total time of the stopwatch.
long	getActive() Returns current number of measured splits (concurrently running).
long	getCounter() Returns usage count of the stopwatch.
long	getLast() Returns value of the last added split - wheter it was added directly or with stop method.
long	getMax() Returns maximal time split value in nanoseconds.
long	getMaxActive() Returns peek value of active concurrent splits.
long	getMaxActiveTimestamp() Retruns ms timestamp when the last peek of the active split count occured.
long	getMaxTimestamp() Returns ms timestamp when the max value was measured.
double	getMean() Returns zero.
long	getMin() Returns minimal time split value in nanoseconds.
long	getMinTimestamp() Returns ms timestamp when the min value was measured.
double	getStandardDeviation() Returns zero.
long	getTotal() Returns total sum of all split times in nanoseconds.
double	getVariance() Returns zero.
double	getVarianceN() Returns zero.
NullStopwatch	reset() Resets the Simon values related to the measuring, timestamps and so on - usage timestamps, state, attributes are not affected.
StopwatchSample	sample() Samples Simon values and returns them in a Java Bean derived from Sample interface.
StopwatchSample	sampleAndReset() Samples Simon values and returns them in a Java Bean derived from Sample interface and resets the Simon.
Split	start() Starts the new split for this stopwatch.

Methods inherited from class org.javasimon.NullSimon

getAttribute, getAttribute, getAttributeNames, getCopyAsSortedMap, getFirstUsage, getChildren, getLastReset, getLastUsage, getName, getNote, getParent, getState, isEnabled, removeAttribute, setAttribute, setNote, setState, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.javasimon.Simon

getFirstUsage, getChildren, getLastReset, getLastUsage, getName, getNote, getParent, getState, isEnabled, setNote, setState

Methods inherited from interface org.javasimon.HasAttributes

getAttribute, getAttribute, getAttributeNames, getCopyAsSortedMap, removeAttribute, setAttribute

Field Detail

INSTANCE

static final NullStopwatch INSTANCE

Internal singleton value of the null Stopwatch. Null Stopwatch is never directly used in the client code, it is always hidden behind the Stopwatch interface - only its behavior manifests to the client.

NULL_SPLIT

private static final Split NULL_SPLIT

Constructor Detail

NullStopwatch

private NullStopwatch()

Method Detail

reset

public NullStopwatch reset()

Description copied from interface: Simon

Resets the Simon values related to the measuring, timestamps and so on - usage timestamps, state, attributes are not affected. Timestamp of the last reset can be obtained by the method Simon.getLastReset(). Reset is perfomed even for disabled Simons.

Specified by:

reset in interface Simon

Specified by:

reset in interface Stopwatch

Overrides:

reset in class NullSimon

Returns:

returns this

getCounter

public long getCounter()

Description copied from interface: Stopwatch

Returns usage count of the stopwatch. Counter is increased by addTime and stop - that means that it's updated every time the next time split is added.

Specified by:

getCounter in interface Stopwatch

Returns:

count of time splits

getMin

public long getMin()

Description copied from interface: Stopwatch

Returns minimal time split value in nanoseconds.

Specified by:

getMin in interface Stopwatch

Returns:

minimal time split in nanoseconds

getMax

public long getMax()

Description copied from interface: Stopwatch

Returns maximal time split value in nanoseconds.

Specified by:

getMax in interface Stopwatch

Returns:

maximal time split in nanoseconds

getMaxTimestamp

public long getMaxTimestamp()

Description copied from interface: Stopwatch

Returns ms timestamp when the max value was measured.

Specified by:

getMaxTimestamp in interface Stopwatch

Returns:

ms timestamp of the max value measurement

getMinTimestamp

public long getMinTimestamp()

Description copied from interface: Stopwatch

Returns ms timestamp when the min value was measured.

Specified by:

getMinTimestamp in interface Stopwatch

Returns:

ms timestamp of the min value measurement

addTime

public Stopwatch addTime(long ns)

Description copied from interface: Stopwatch

Adds split time in nanoseconds to total time of the stopwatch.

Specified by:

addTime in interface Stopwatch

Parameters:

ns - split time

Returns:

this stopwatch

addSplit

public Stopwatch addSplit(Split split)

Description copied from interface: Stopwatch

Adds Split to the stopwatch which is useful for aggregation of splits created for other stopwatch. Split object should be stopped. Main difference is the callback method called as Callback.onStopwatchAdd(Stopwatch, Split, StopwatchSample) provides split object to the callback.

Usage examples:

Split split = Split.start(); // no stopwatch needed
...
someStopwatch.addSplit(split.stop()); // you may omit stop(), if you does not use the split after this point

Specified by:

addSplit in interface Stopwatch

Parameters:

split - split object (should be stopped)

Returns:

this stopwatch

start

public Split start()

Description copied from interface: Stopwatch

Starts the new split for this stopwatch. This action does not hold any resources and if Split object is collected, no leak occurs. However, active count is increased and without stopping the split active count stays increased which may render that information useless.

Specified by:

start in interface Stopwatch

Returns:

split object

See Also:

Split.stop()

getTotal

public long getTotal()

Description copied from interface: Stopwatch

Returns total sum of all split times in nanoseconds.

Specified by:

getTotal in interface Stopwatch

Returns:

total time of the stopwatch in nanoseconds

getLast

public long getLast()

Description copied from interface: Stopwatch

Returns value of the last added split - wheter it was added directly or with stop method.

Specified by:

getLast in interface Stopwatch

Returns:

value of the last added split

getActive

public long getActive()

Description copied from interface: Stopwatch

Returns current number of measured splits (concurrently running). This counter can show more splits than is measured at any moment if some splits were "forgotten" (not stopped and garbage collected). This does not imply any resource leak, just bad practice of not stopping Splits somewhere in the client code.

Specified by:

getActive in interface Stopwatch

Returns:

current number of active splits

getMaxActive

public long getMaxActive()

Description copied from interface: Stopwatch

Returns peek value of active concurrent splits.

Specified by:

getMaxActive in interface Stopwatch

Returns:

maximum reached value of active splits

getMaxActiveTimestamp

public long getMaxActiveTimestamp()

Description copied from interface: Stopwatch

Retruns ms timestamp when the last peek of the active split count occured.

Specified by:

getMaxActiveTimestamp in interface Stopwatch

Returns:

ms timestamp of the last peek of the active split count

getMean

public double getMean()

Returns zero.

Specified by:

getMean in interface Stopwatch

Returns:

zero

getStandardDeviation

public double getStandardDeviation()

Returns zero.

Specified by:

getStandardDeviation in interface Stopwatch

Returns:

zero

getVariance

public double getVariance()

Returns zero.

Specified by:

getVariance in interface Stopwatch

Returns:

zero

getVarianceN

public double getVarianceN()

Returns zero.

Specified by:

getVarianceN in interface Stopwatch

Returns:

zero

sample

public StopwatchSample sample()

Description copied from interface: Simon

Samples Simon values and returns them in a Java Bean derived from Sample interface.

Specified by:

sample in interface Simon

Specified by:

sample in interface Stopwatch

Overrides:

sample in class NullSimon

Returns:

sample containing all Simon values

sampleAndReset

public StopwatchSample sampleAndReset()

Description copied from interface: Simon

Samples Simon values and returns them in a Java Bean derived from Sample interface and resets the Simon. Operation is synchronized to assure atomicity.

Specified by:

sampleAndReset in interface Simon

Specified by:

sampleAndReset in interface Stopwatch

Overrides:

sampleAndReset in class NullSimon

Returns:

sample containing all Simon values