Package org.terracotta.statistics

Class ZeroOperationStatistic<T extends java.lang.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 java.lang.Enum<T>>
extends java.lang.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 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 java.lang.Enum<T>> OperationStatistic<T>	get()
java.util.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(java.util.Set<T> types)
java.lang.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 Detail

INSTANCE

private static final OperationStatistic<?> INSTANCE

Constructor Detail

ZeroOperationStatistic

public ZeroOperationStatistic()

Method Detail

get

public static <T extends java.lang.Enum<T>> OperationStatistic<T> get()

type

public java.lang.Class<T> type()

Specified by:

type in interface OperationStatistic<T extends java.lang.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 java.lang.Enum<T>>

Parameters:

type - the result type

Returns:

the operation count

sum

public long sum(java.util.Set<T> types)

Specified by:

sum in interface OperationStatistic<T extends java.lang.Enum<T>>

sum

public long sum()

Specified by:

sum in interface OperationStatistic<T extends java.lang.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 java.lang.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 java.lang.Enum<T>>

Parameters:

derived - statistic to be removed

getDerivedStatistics

public java.util.Collection<ChainedOperationObserver<? super T>> getDerivedStatistics()

Description copied from interface: SourceStatistic

Retrieve all registered statistics.

Specified by:

getDerivedStatistics in interface SourceStatistic<T extends java.lang.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 java.lang.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 java.lang.Enum<T>>

Parameters:

result - the operation result