org.infinispan.counter.api.StrongCounter Maven / Gradle / Ivy
package org.infinispan.counter.api;
import java.util.concurrent.CompletableFuture;
/**
* The strong consistent counter interface.
*
* It provides atomic updates for the counter. All the operations are perform asynchronously and they complete the
* {@link CompletableFuture} when completed.
*
* @author Pedro Ruivo
* @since 9.0
*/
public interface StrongCounter {
/**
* @return The counter name.
*/
String getName();
/**
* It fetches the current value.
*
* It may go remotely to fetch the current value.
*
* @return The current value.
*/
CompletableFuture getValue();
/**
* Atomically increments the counter and returns the new value.
*
* @return The new value.
*/
default CompletableFuture incrementAndGet() {
return addAndGet(1L);
}
/**
* Atomically decrements the counter and returns the new value
*
* @return The new value.
*/
default CompletableFuture decrementAndGet() {
return addAndGet(-1L);
}
/**
* Atomically adds the given value and return the new value.
*
* @param delta The non-zero value to add. It can be negative.
* @return The new value.
*/
CompletableFuture addAndGet(long delta);
/**
* Resets the counter to its initial value.
*/
CompletableFuture reset();
/**
* Registers a {@link CounterListener} to this counter.
*
* @param listener The listener to register.
* @param The concrete type of the listener. It must implement {@link CounterListener}.
* @return A {@link Handle} that allows to remove the listener via {@link Handle#remove()}.
*/
Handle addListener(T listener);
/**
* Atomically sets the value to the given updated value if the current value {@code ==} the expected value.
*
* It is the same as {@code return compareAndSwap(expect, update).thenApply(value -> value == expect);}
*
* @param expect the expected value
* @param update the new value
* @return {@code true} if successful, {@code false} otherwise.
*/
default CompletableFuture compareAndSet(long expect, long update) {
return compareAndSwap(expect, update).thenApply(value -> value == expect);
}
/**
* Atomically sets the value to the given updated value if the current value {@code ==} the expected value.
*
* The operation is successful if the return value is equals to the expected value.
*
* @param expect the expected value.
* @param update the new value.
* @return the previous counter's value.
*/
CompletableFuture compareAndSwap(long expect, long update);
/**
* @return the {@link CounterConfiguration} used by this counter.
*/
CounterConfiguration getConfiguration();
/**
* It removes this counter from the cluster.
*
* Note that it doesn't remove the counter from the {@link CounterManager}. If you want to remove the counter from
* the {@link CounterManager} use {@link CounterManager#remove(String)}.
*
* @return The {@link CompletableFuture} that is completed when the counter is removed from the cluster.
*/
CompletableFuture remove();
/**
* It returns a synchronous strong counter for this instance.
*
* @return a {@link SyncStrongCounter}.
*/
SyncStrongCounter sync();
}