Package org.terracotta.statistics

Class ZeroOperationStatistic<T extends Enum<T>>

java.lang.Object

org.terracotta.statistics.ZeroOperationStatistic<T>

All Implemented Interfaces:

OperationObserver<T>, OperationStatistic<T>, SourceStatistic<ChainedOperationObserver<? super T>>

public class ZeroOperationStatistic<T extends Enum<T>>
extends Object
implements OperationStatistic<T>

An operation statistic that always return 0 for everything. Used as a null object.

Field Summary

Fields

Modifier and Type	Field	Description
private static final OperationStatistic<?>	INSTANCE

Constructor Summary

Constructors

Constructor	Description
ZeroOperationStatistic()

Method Summary

Modifier and Type	Method	Description
void	addDerivedStatistic(ChainedOperationObserver<? super T> derived)	Register the given Observer to be called by this SourceStatistic
void	begin()	Called immediately prior to the operation beginning.
long	count(T type)	Return the count of operations with the given type.
void	end(T result)	Called immediately after the operation completes with no interesting parameters, and with the same thread the called {OperationObserver.begin()} before.
static <T extends Enum<T>> OperationStatistic<T>	get()
Collection<ChainedOperationObserver<? super T>>	getDerivedStatistics()	Retrieve all registered statistics.
void	removeDerivedStatistic(ChainedOperationObserver<? super T> derived)	Remove the given registered Observer from this SourceStatistic.
long	sum()
long	sum(Set<T> types)
Class<T>	type()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.terracotta.statistics.OperationStatistic

statistic, statistic

Field Details

INSTANCE

private static final OperationStatistic<?> INSTANCE

Constructor Details

ZeroOperationStatistic

public ZeroOperationStatistic()

Method Details

get

public static <T extends Enum<T>>
OperationStatistic<T> get()

type

public Class<T> type()

Specified by:

type in interface OperationStatistic<T extends Enum<T>>

count

public long count(T type)

Description copied from interface: OperationStatistic

Return the count of operations with the given type.

Specified by:

count in interface OperationStatistic<T extends Enum<T>>

Parameters:

type - the result type

Returns:

the operation count

sum

public long sum(Set<T> types)

Specified by:

sum in interface OperationStatistic<T extends Enum<T>>

sum

public long sum()

Specified by:

sum in interface OperationStatistic<T extends Enum<T>>

addDerivedStatistic

public void addDerivedStatistic(ChainedOperationObserver<? super T> derived)

Description copied from interface: SourceStatistic

Register the given Observer to be called by this SourceStatistic

Specified by:

addDerivedStatistic in interface SourceStatistic<T extends Enum<T>>

Parameters:

derived - statistic to be registered

removeDerivedStatistic

public void removeDerivedStatistic(ChainedOperationObserver<? super T> derived)

Description copied from interface: SourceStatistic

Remove the given registered Observer from this SourceStatistic.

Specified by:

removeDerivedStatistic in interface SourceStatistic<T extends Enum<T>>

Parameters:

derived - statistic to be removed

getDerivedStatistics

public Collection<ChainedOperationObserver<? super T>> getDerivedStatistics()

Description copied from interface: SourceStatistic

Retrieve all registered statistics.

Specified by:

getDerivedStatistics in interface SourceStatistic<T extends Enum<T>>

Returns:

an unmodifiable collection of all derived statistics

begin

public void begin()

Description copied from interface: OperationObserver

Called immediately prior to the operation beginning.

Specified by:

begin in interface OperationObserver<T extends Enum<T>>

end

public void end(T result)

Description copied from interface: OperationObserver

Called immediately after the operation completes with no interesting parameters, and with the same thread the called {OperationObserver.begin()} before.

Specified by:

end in interface OperationObserver<T extends Enum<T>>

Parameters:

result - the operation result