Copyright 2011-2016 Terracotta, Inc.
Copyright 2011-2016 Oracle America Incorporated
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
/**
 * Copyright 2011-2016 Terracotta, Inc.
 * Copyright 2011-2016 Oracle America Incorporated
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package javax.cache.expiry;

import javax.cache.configuration.Factory;
import javax.cache.configuration.FactoryBuilder;
import java.io.Serializable;

An ExpiryPolicy that defines the expiry Duration of a Cache Entry based on when it was last touched. A touch includes creation, update or access. 
Author:
Greg Luck, Brian Oliver
See Also:
ExpiryPolicy
Since:
1.0/**
 * An {@link ExpiryPolicy} that defines the expiry {@link Duration}
 * of a Cache Entry based on when it was last touched. A touch includes
 * creation, update or access.
 *
 * @author Greg Luck
 * @author Brian Oliver
 * @since 1.0
 * @see ExpiryPolicy
 */
public final class TouchedExpiryPolicy implements ExpiryPolicy, Serializable {

  
The serialVersionUID required for Serializable. /**
   * The serialVersionUID required for {@link java.io.Serializable}.
   */
  public static final long serialVersionUID = 201305291023L;

  
The Duration a Cache Entry should be available before it expires. /**
   * The {@link Duration} a Cache Entry should be available before it expires.
   */
  private Duration expiryDuration;

  
Constructs an TouchedExpiryPolicy ExpiryPolicy. 
Params:
expiryDuration – the Duration a Cache Entry should exist be before it expires after being modified/**
   * Constructs an {@link TouchedExpiryPolicy} {@link ExpiryPolicy}.
   *
   * @param expiryDuration the {@link Duration} a Cache Entry should exist be
   *                       before it expires after being modified
   */
  public TouchedExpiryPolicy(Duration expiryDuration) {
    this.expiryDuration = expiryDuration;
  }

  
Obtains a Factory for a Touched ExpiryPolicy. 
Params:
duration – The expiry duration
Returns:
a Factory for a Touched ExpiryPolicy./**
   * Obtains a {@link Factory} for a Touched {@link ExpiryPolicy}.
   * @param duration The expiry duration
   * @return a {@link Factory} for a Touched {@link ExpiryPolicy}.
   */
  public static Factory<ExpiryPolicy> factoryOf(Duration duration) {
    return new FactoryBuilder.SingletonFactory<ExpiryPolicy>(new TouchedExpiryPolicy(duration));
  }

  
{@inheritDoc}
/**
   * {@inheritDoc}
   */
  @Override
  public Duration getExpiryForCreation() {
    //for newly created entries we use the specified expiry duration.
    return expiryDuration;
  }

  
{@inheritDoc}
/**
   * {@inheritDoc}
   */
  @Override
  public Duration getExpiryForAccess() {
    //accessing a cache entry resets the duration.
    return expiryDuration;
  }

  
{@inheritDoc}
/**
   * {@inheritDoc}
   */
  @Override
  public Duration getExpiryForUpdate() {
    //updating a cache entry resets the duration.
    return expiryDuration;
  }

  
{@inheritDoc}
/**
   * {@inheritDoc}
   */
  @Override
  public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + ((expiryDuration == null) ? 0 : expiryDuration.hashCode());
    return result;
  }

  
{@inheritDoc}
/**
   * {@inheritDoc}
   */
  @Override
  public boolean equals(Object object) {
    if (this == object) {
      return true;
    }
    if (object == null) {
      return false;
    }
    if (!(object instanceof TouchedExpiryPolicy)) {
      return false;
    }
    TouchedExpiryPolicy other = (TouchedExpiryPolicy) object;
    if (expiryDuration == null) {
      if (other.expiryDuration != null) {
        return false;
      }
    } else if (!expiryDuration.equals(other.expiryDuration)) {
      return false;
    }
    return true;
  }
}