Expirable.java

/*
 * Copyright 2015 Ben Manes. All Rights Reserved.
 *
 * 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 com.github.benmanes.caffeine.jcache;

import static java.util.Objects.requireNonNull;

/**
 * A value with an expiration timestamp.
 *
 * @author ben.manes@gmail.com (Ben Manes)
 */
public final class Expirable<V> {
  private final V value;

  private volatile long expireTimeMS;

  public Expirable(V value, long expireTimeMS) {
    this.value = requireNonNull(value);
    this.expireTimeMS = expireTimeMS;
  }

  /** Returns the value. */
  public V get() {
    return value;
  }

  /** Returns the time, in milliseconds, when the value will expire. */
  public long getExpireTimeMS() {
    return expireTimeMS;
  }

  /** Specifies the time, in milliseconds, when the value will expire. */
  public void setExpireTimeMS(long expireTimeMS) {
    this.expireTimeMS = expireTimeMS;
  }

  /** Returns if the value has expired and is eligible for eviction. */
  public boolean hasExpired(long currentTimeMS) {
    return (currentTimeMS - expireTimeMS) >= 0;
  }

  /** Returns if the value will never expire. */
  public boolean isEternal() {
    return (expireTimeMS == Long.MAX_VALUE);
  }

  @Override
  public String toString() {
    return String.format("%s{value=%s, expireTimeMS=%,d}",
        getClass().getSimpleName(), value, expireTimeMS);
  }
}