Package org.infinispan.counter.api

Interface StrongCounter

public interface StrongCounter

The strong consistent counter interface.

It provides atomic updates for the counter. All the operations are perform asynchronously and they complete the CompletableFuture when completed.

Since:

9.0

Author:

Pedro Ruivo

Method Summary

Modifier and Type	Method	Description
CompletableFuture<Long>	addAndGet(long delta)	Atomically adds the given value and return the new value.
<T extends CounterListener> Handle<T>	addListener(T listener)	Registers a CounterListener to this counter.
default CompletableFuture<Boolean>	compareAndSet(long expect, long update)	Atomically sets the value to the given updated value if the current value == the expected value.
CompletableFuture<Long>	compareAndSwap(long expect, long update)	Atomically sets the value to the given updated value if the current value == the expected value.
default CompletableFuture<Long>	decrementAndGet()	Atomically decrements the counter and returns the new value
CounterConfiguration	getConfiguration()
String	getName()
CompletableFuture<Long>	getValue()	It fetches the current value.
default CompletableFuture<Long>	incrementAndGet()	Atomically increments the counter and returns the new value.
CompletableFuture<Void>	remove()	It removes this counter from the cluster.
CompletableFuture<Void>	reset()	Resets the counter to its initial value.
SyncStrongCounter	sync()	It returns a synchronous strong counter for this instance.

Method Detail

getName

String getName()

Returns:

The counter name.

getValue

CompletableFuture<Long> getValue()

It fetches the current value.

It may go remotely to fetch the current value.

Returns:

The current value.

incrementAndGet

default CompletableFuture<Long> incrementAndGet()

Atomically increments the counter and returns the new value.

Returns:

The new value.

decrementAndGet

default CompletableFuture<Long> decrementAndGet()

Atomically decrements the counter and returns the new value

Returns:

The new value.

addAndGet

CompletableFuture<Long> addAndGet(long delta)

Atomically adds the given value and return the new value.

Parameters:

delta - The non-zero value to add. It can be negative.

Returns:

The new value.

reset

CompletableFuture<Void> reset()

Resets the counter to its initial value.

addListener

<T extends CounterListener> Handle<T> addListener(T listener)

Registers a CounterListener to this counter.

Type Parameters:

T - The concrete type of the listener. It must implement CounterListener.

Parameters:

listener - The listener to register.

Returns:

A Handle that allows to remove the listener via Handle.remove().

compareAndSet

default CompletableFuture<Boolean> compareAndSet(long expect,
                                                 long update)

Atomically sets the value to the given updated value if the current value == the expected value. It is the same as return compareAndSwap(expect, update).thenApply(value -> value == expect);

Parameters:

expect - the expected value

update - the new value

Returns:

true if successful, false otherwise.

compareAndSwap

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

Atomically sets the value to the given updated value if the current value == the expected value. The operation is successful if the return value is equals to the expected value.

Parameters:

expect - the expected value.

update - the new value.

Returns:

the previous counter's value.

getConfiguration

CounterConfiguration getConfiguration()

Returns:

the CounterConfiguration used by this counter.

remove

CompletableFuture<Void> remove()

It removes this counter from the cluster.

Note that it doesn't remove the counter from the CounterManager. If you want to remove the counter from the CounterManager use CounterManager.remove(String).

Returns:

The CompletableFuture that is completed when the counter is removed from the cluster.

sync

SyncStrongCounter sync()

It returns a synchronous strong counter for this instance.

Returns:

a SyncStrongCounter.