java.lang.Object
- org.infinispan.counter.impl.strong.AbstractStrongCounter

All Implemented Interfaces:

StrongCounter, CounterEventGenerator, InternalCounterAdmin

Direct Known Subclasses:

BoundedStrongCounter, UnboundedStrongCounter
```
public abstract class AbstractStrongCounter
extends Object
implements 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

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
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.
`StrongCounter`	`asStrongCounter()`
`CompletableFuture<Long>`	`compareAndSwap(long expect, long update)`	Atomically sets the value to the given updated value if the current value `==` the expected value.
`CompletionStage<Void>`	`destroy()`	Destroys the counter.
`CounterEvent`	`generate(CounterKey key, CounterValue value)`	It generates the `CounterEvent`.
`CounterConfiguration`	`getConfiguration()`
`String`	`getName()`
`CompletableFuture<Long>`	`getValue()`	It fetches the current value.
`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()`	It removes this counter from the cluster.
`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.
`SyncStrongCounter`	`sync()`	It returns a synchronous strong counter for this instance.
`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 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 StrongCounter
    
    Returns:
    
    The counter name.
  - getValue
```
public final CompletableFuture<Long> getValue()
```
    Description copied from interface: StrongCounter
    
    It fetches the current value.
    It may go remotely to fetch the current value.
    
    Specified by:
    
    getValue in interface StrongCounter
    
    Returns:
    
    The current value.
  - addAndGet
```
public final CompletableFuture<Long> addAndGet(long delta)
```
    Description copied from interface: StrongCounter
    
    Atomically adds the given value and return the new value.
    
    Specified by:
    
    addAndGet in interface StrongCounter
    
    Parameters:
    
    delta - The non-zero value to add. It can be negative.
    
    Returns:
    
    The new value.
  - reset
```
public final CompletableFuture<Void> reset()
```
    Description copied from interface: StrongCounter
    
    Resets the counter to its initial value.
    
    Specified by:
    
    reset in interface InternalCounterAdmin
    
    Specified by:
    
    reset in interface StrongCounter
    
    Returns:
    
    A CompletionStage instance which is completed when the operation finishes.
  - addListener
```
public final <T extends CounterListener> Handle<T> addListener(T listener)
```
    Description copied from interface: StrongCounter
    
    Registers a CounterListener to this counter.
    
    Specified by:
    
    addListener in interface StrongCounter
    
    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().
  - compareAndSwap
```
public CompletableFuture<Long> compareAndSwap(long expect,
                                              long update)
```
    Description copied from interface: StrongCounter
    
    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.
    
    Specified by:
    
    compareAndSwap in interface StrongCounter
    
    Parameters:
    
    expect - the expected value.
    
    update - the new value.
    
    Returns:
    
    the previous counter's value.
  - generate
```
public 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()
```
    Description copied from interface: StrongCounter
    
    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).
    
    Specified by:
    
    remove in interface StrongCounter
    
    Returns:
    
    The CompletableFuture that is completed when the counter is removed from the cluster.
  - getConfiguration
```
public final CounterConfiguration getConfiguration()
```
    Specified by:
    
    getConfiguration in interface StrongCounter
    
    Returns:
    
    the CounterConfiguration used by this counter.
  - sync
```
public SyncStrongCounter sync()
```
    Description copied from interface: StrongCounter
    
    It returns a synchronous strong counter for this instance.
    
    Specified by:
    
    sync in interface StrongCounter
    
    Returns:
    
    a SyncStrongCounter.
  - 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.

Class AbstractStrongCounter

Method Summary

Methods inherited from class java.lang.Object

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

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

Method Detail

removeStrongCounter

init

asStrongCounter

destroy

value

isWeakCounter

getName

getValue

addAndGet

reset

addListener

compareAndSwap

generate

remove

getConfiguration

sync

handleCASResult

handleAddResult