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Infinispan core module

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package org.infinispan.affinity;

import org.infinispan.commons.api.Lifecycle;
import org.infinispan.remoting.transport.Address;

/**
 * Defines a service that generates keys to be mapped to specific nodes in a distributed(vs. replicated) cluster.
 * The service is instantiated through through one of the factory methods from {@link org.infinispan.affinity.KeyAffinityServiceFactory}.
 * 
 * Sample usage:
 * 

 * 

 *    Cache<String, Long> cache = getDistributedCache();
 *    KeyAffinityService<String> service = KeyAffinityServiceFactory.newKeyAffinityService(cache, 100);
 *    ...
 *    String sessionId = sessionObject.getId();
 *    String newCollocatedSession = service.getCollocatedKey(sessionId);
 *
 *    //this will reside on the same node in the cluster
 *    cache.put(newCollocatedSession, someInfo);
 * 
 * 
 * Uniqueness: the service does not guarantee that the generated keys are unique. It relies on an
 * {@link org.infinispan.affinity.KeyGenerator} for obtaining and distributing the generated keys. If key uniqueness is
 * needed that should be enforced in the generator.
 * 
 * The service might also drop key generated through the {@link org.infinispan.affinity.KeyGenerator}.
 *
 * @see org.infinispan.affinity.KeyAffinityServiceFactory
 * @author [email protected]
 * @since 4.1
 */
public interface KeyAffinityService extends Lifecycle {

   /**
    * Returns a key that will be distributed on the cluster node identified by address.
    * @param address identifying the cluster node.
    * @return a key object
    * @throws IllegalStateException if the service has not been started or it is shutdown
    */
   K getKeyForAddress(Address address);

   /**
    * Returns a key that will be distributed on the same node as the supplied key.
    * @param otherKey the key for which we need a collocation
    * @return a key object
    * @throws IllegalStateException if the service has not been started or it is shutdown
    */
   K getCollocatedKey(K otherKey);

   /**
    * Checks weather or not the service is started.
    */
   boolean isStarted();
}