Package org.infinispan.counter.impl.strong

Class AbstractStrongCounter

java.lang.Object

org.infinispan.counter.impl.strong.AbstractStrongCounter

All Implemented Interfaces:

org.infinispan.counter.api.StrongCounter, CounterEventGenerator, InternalCounterAdmin

Direct Known Subclasses:

BoundedStrongCounter, UnboundedStrongCounter

public abstract class AbstractStrongCounter
extends Object
implements org.infinispan.counter.api.StrongCounter, CounterEventGenerator, InternalCounterAdmin

A base strong consistent counter implementation.

Implementation: The value is stored in a single key and it uses the Infinispan's concurrency control and distribution to apply the write and reads. It uses the functional API.

Writes: The writes are performed by the functional API in order. The single key approach allows us to provide atomic properties for the counter value.

Reads: The reads read the value from the cache and it can go remotely.

Weak Reads: This implementation supports weak cached reads. It uses clustered listeners to receive the notifications of the actual value to store it locally.

Since:

9.0

Author:

Pedro Ruivo

Method Summary

Modifier and Type	Method	Description
CompletableFuture<Long>	addAndGet(long delta)
<T extends org.infinispan.counter.api.CounterListener> org.infinispan.counter.api.Handle<T>	addListener(T listener)
org.infinispan.counter.api.StrongCounter	asStrongCounter()
CompletableFuture<Long>	compareAndSwap(long expect, long update)
CompletionStage<Void>	destroy()	Destroys the counter.
org.infinispan.counter.api.CounterEvent	generate(CounterKey key, CounterValue value)	It generates the CounterEvent.
org.infinispan.counter.api.CounterConfiguration	getConfiguration()
String	getName()
CompletableFuture<Long>	getValue()
protected abstract long	handleAddResult(CounterValue counterValue)	Extracts and validates the value after a read.
protected abstract Long	handleCASResult(Object state)
CompletionStage<InternalCounterAdmin>	init()
boolean	isWeakCounter()	Checks if the counter is a WeakCounter.
CompletableFuture<Void>	remove()
static CompletionStage<Void>	removeStrongCounter(org.infinispan.Cache<StrongCounterKey,CounterValue> cache, String counterName)	It removes a strong counter from the cache, identified by the counterName.
CompletableFuture<Void>	reset()	Resets the counter to its initial value.
org.infinispan.counter.api.SyncStrongCounter	sync()
CompletionStage<Long>	value()	Returns the counter's value.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.infinispan.counter.impl.manager.InternalCounterAdmin

asWeakCounter

Methods inherited from interface org.infinispan.counter.api.StrongCounter

compareAndSet, decrementAndGet, incrementAndGet

Method Detail

removeStrongCounter

public static CompletionStage<Void> removeStrongCounter(org.infinispan.Cache<StrongCounterKey,CounterValue> cache,
                                                        String counterName)

It removes a strong counter from the cache, identified by the counterName.

Parameters:

cache - The Cache to remove the counter from.

counterName - The counter's name.

init

public final CompletionStage<InternalCounterAdmin> init()

asStrongCounter

public org.infinispan.counter.api.StrongCounter asStrongCounter()

Specified by:

asStrongCounter in interface InternalCounterAdmin

Returns:

The StrongCounter instance or throws an CounterException if the counter is not a StrongCounter.

destroy

public CompletionStage<Void> destroy()

Description copied from interface: InternalCounterAdmin

Destroys the counter.

It drops the counter's value and all listeners registered.

Specified by:

destroy in interface InternalCounterAdmin

Returns:

A CompletionStage instance which is completed when the operation finishes.

value

public CompletionStage<Long> value()

Description copied from interface: InternalCounterAdmin

Returns the counter's value.

Specified by:

value in interface InternalCounterAdmin

Returns:

A CompletionStage instance which is completed when the operation finishes.

isWeakCounter

public boolean isWeakCounter()

Description copied from interface: InternalCounterAdmin

Checks if the counter is a WeakCounter.

If true, ensures InternalCounterAdmin.asWeakCounter() never throws an CounterException. Otherwise, it ensures InternalCounterAdmin.asStrongCounter() never throws an CounterException.

Specified by:

isWeakCounter in interface InternalCounterAdmin

Returns:

true if the counter is WeakCounter.

getName

public final String getName()

Specified by:

getName in interface org.infinispan.counter.api.StrongCounter

getValue

public final CompletableFuture<Long> getValue()

Specified by:

getValue in interface org.infinispan.counter.api.StrongCounter

addAndGet

public final CompletableFuture<Long> addAndGet(long delta)

Specified by:

addAndGet in interface org.infinispan.counter.api.StrongCounter

reset

public final CompletableFuture<Void> reset()

Description copied from interface: InternalCounterAdmin

Resets the counter to its initial value.

Specified by:

reset in interface InternalCounterAdmin

Specified by:

reset in interface org.infinispan.counter.api.StrongCounter

Returns:

A CompletionStage instance which is completed when the operation finishes.

addListener

public final <T extends org.infinispan.counter.api.CounterListener> org.infinispan.counter.api.Handle<T> addListener(T listener)

Specified by:

addListener in interface org.infinispan.counter.api.StrongCounter

compareAndSwap

public CompletableFuture<Long> compareAndSwap(long expect,
                                              long update)

Specified by:

compareAndSwap in interface org.infinispan.counter.api.StrongCounter

generate

public org.infinispan.counter.api.CounterEvent generate(CounterKey key,
                                                        CounterValue value)

Description copied from interface: CounterEventGenerator

It generates the CounterEvent.

The value is the new value of CounterEvent.

Specified by:

generate in interface CounterEventGenerator

Parameters:

key - The counter's key.

value - The counter's most recent CounterValue.

Returns:

The CounterEvent with the updated value.

remove

public CompletableFuture<Void> remove()

Specified by:

remove in interface org.infinispan.counter.api.StrongCounter

getConfiguration

public final org.infinispan.counter.api.CounterConfiguration getConfiguration()

Specified by:

getConfiguration in interface org.infinispan.counter.api.StrongCounter

sync

public org.infinispan.counter.api.SyncStrongCounter sync()

Specified by:

sync in interface org.infinispan.counter.api.StrongCounter

handleCASResult

protected abstract Long handleCASResult(Object state)

handleAddResult

protected abstract long handleAddResult(CounterValue counterValue)

Extracts and validates the value after a read.

Any exception should be thrown using CompletionException.

Parameters:

counterValue - The new CounterValue.

Returns:

The new value stored in CounterValue.