java.lang.Object
- org.infinispan.counter.impl.weak.WeakCounterImpl

All Implemented Interfaces:

WeakCounter, CounterEventGenerator, TopologyChangeListener, InternalCounterAdmin
```
public class WeakCounterImpl
extends Object
implements WeakCounter, CounterEventGenerator, TopologyChangeListener, InternalCounterAdmin
```
A weak consistent counter implementation.
Implementation: The counter is split in multiple keys and they are stored in the cache.
Write: A write operation will pick a key to update. If the node is a primary owner of one of the key, that key is chosen based on thread-id. This will take advantage of faster write operations. If the node is not a primary owner, one of the key in key set is chosen.
Read: A read operation needs to read all the key set (including the remote keys). This is slower than atomic counter.
Weak Read: A snapshot of all the keys values is kept locally and they are updated via cluster listeners.
Reset: The reset operation is not atomic and intermediate results may be observed.

Since:

9.0

Author:

Pedro Ruivo

Constructor Summary

Constructors
Constructor	Description
`WeakCounterImpl(String counterName, org.infinispan.AdvancedCache<WeakCounterKey,CounterValue> cache, CounterConfiguration configuration, CounterManagerNotificationManager notificationManager)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`CompletableFuture<Void>`	`add(long delta)`	Adds the given value to the new value.
`<T extends CounterListener> Handle<T>`	`addListener(T listener)`	Adds a `CounterListener` to this counter.
`WeakCounter`	`asWeakCounter()`
`CompletionStage<Void>`	`destroy()`	Destroys the counter.
`CounterEvent`	`generate(CounterKey key, CounterValue value)`	It generates the `CounterEvent`.
`CounterConfiguration`	`getConfiguration()`
`WeakCounterKey[]`	`getKeys()`	Debug only!
`String`	`getName()`
`WeakCounterKey[]`	`getPreferredKeys()`	Debug only!
`long`	`getValue()`	It returns the counter's value.
`CompletionStage<InternalCounterAdmin>`	`init()`	Initializes the key set.
`boolean`	`isWeakCounter()`	Checks if the counter is a `WeakCounter`.
`CompletableFuture<Void>`	`remove()`	It removes this counter from the cluster.
`static CompletionStage<Void>`	`removeWeakCounter(org.infinispan.Cache<WeakCounterKey,CounterValue> cache, CounterConfiguration configuration, String counterName)`	It removes a weak counter from the `cache`, identified by the `counterName`.
`CompletableFuture<Void>`	`reset()`	Resets the counter to its initial value.
`SyncWeakCounter`	`sync()`	It returns a synchronous weak counter for this instance.
`void`	`topologyChanged()`	It notifies the cache topology change.
`String`	`toString()`
`CompletionStage<Long>`	`value()`	Returns the counter's value.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

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

Methods inherited from interface org.infinispan.counter.api.WeakCounter
decrement, increment

- Constructor Detail
  - WeakCounterImpl
```
public WeakCounterImpl(String counterName,
                       org.infinispan.AdvancedCache<WeakCounterKey,CounterValue> cache,
                       CounterConfiguration configuration,
                       CounterManagerNotificationManager notificationManager)
```
- Method Detail
  - removeWeakCounter
```
public static CompletionStage<Void> removeWeakCounter(org.infinispan.Cache<WeakCounterKey,CounterValue> cache,
                                                      CounterConfiguration configuration,
                                                      String counterName)
```
    It removes a weak counter from the cache, identified by the counterName.
    
    Parameters:
    
    cache - The Cache to remove the counter from.
    
    configuration - The counter's configuration.
    
    counterName - The counter's name.
  - init
```
public CompletionStage<InternalCounterAdmin> init()
```
    Initializes the key set.
    Only one key will have the initial value and the remaining is zero.
  - getName
```
public String getName()
```
    Specified by:
    
    getName in interface WeakCounter
    
    Returns:
    
    The counter name.
  - getValue
```
public long getValue()
```
    Description copied from interface: WeakCounter
    
    It returns the counter's value.
    This value may be not the mot up-to-data value.
    
    Specified by:
    
    getValue in interface WeakCounter
    
    Returns:
    
    The counter's value.
  - add
```
public CompletableFuture<Void> add(long delta)
```
    Description copied from interface: WeakCounter
    
    Adds the given value to the new value.
    
    Specified by:
    
    add in interface WeakCounter
    
    Parameters:
    
    delta - the value to add.
  - asWeakCounter
```
public WeakCounter asWeakCounter()
```
    Specified by:
    
    asWeakCounter in interface InternalCounterAdmin
    
    Returns:
    
    The WeakCounter instance or throws an CounterException if the counter is not a WeakCounter.
  - 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.
  - reset
```
public CompletableFuture<Void> reset()
```
    Description copied from interface: WeakCounter
    
    Resets the counter to its initial value.
    
    Specified by:
    
    reset in interface InternalCounterAdmin
    
    Specified by:
    
    reset in interface WeakCounter
    
    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.
  - addListener
```
public <T extends CounterListener> Handle<T> addListener(T listener)
```
    Description copied from interface: WeakCounter
    
    Adds a CounterListener to this counter.
    
    Specified by:
    
    addListener in interface WeakCounter
    
    Type Parameters:
    
    T - The type of the listener. It must implement CounterListener.
    
    Parameters:
    
    listener - The listener to add.
    
    Returns:
    
    A Handle that allows to remove the listener via Handle.remove() ()}.
  - getConfiguration
```
public CounterConfiguration getConfiguration()
```
    Specified by:
    
    getConfiguration in interface WeakCounter
    
    Returns:
    
    the CounterConfiguration used by this counter.
  - 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: WeakCounter
    
    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 WeakCounter
    
    Returns:
    
    The CompletableFuture that is completed when the counter is removed from the cluster.
  - sync
```
public SyncWeakCounter sync()
```
    Description copied from interface: WeakCounter
    
    It returns a synchronous weak counter for this instance.
    
    Specified by:
    
    sync in interface WeakCounter
    
    Returns:
    
    a SyncWeakCounter.
  - topologyChanged
```
public void topologyChanged()
```
    Description copied from interface: TopologyChangeListener
    
    It notifies the cache topology change.
    
    Specified by:
    
    topologyChanged in interface TopologyChangeListener
  - getPreferredKeys
```
public WeakCounterKey[] getPreferredKeys()
```
    Debug only!
  - getKeys
```
public WeakCounterKey[] getKeys()
```
    Debug only!
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class WeakCounterImpl

Constructor Summary

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.WeakCounter

Constructor Detail

WeakCounterImpl

Method Detail

removeWeakCounter

init

getName

getValue

add

asWeakCounter

destroy

reset

value

isWeakCounter

addListener

getConfiguration

generate

remove

sync

topologyChanged

getPreferredKeys

getKeys

toString