/*
 * Copyright (C) 2011 The Guava Authors
 *
 * 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.google.common.cache;

import com.google.common.annotations.GwtCompatible;
import java.util.Iterator;
import java.util.Map;
import java.util.concurrent.ConcurrentMap;

The reason why a cached entry was removed.
Author:
Charles Fry
Since:
10.0/**
 * The reason why a cached entry was removed.
 *
 * @author Charles Fry
 * @since 10.0
 */
@GwtCompatible
public enum RemovalCause {
  
The entry was manually removed by the user. This can result from the user invoking Cache.invalidate, Cache.invalidateAll(Iterable), Cache.invalidateAll(), Map.remove, Map.remove, or Iterator.remove. /**
   * The entry was manually removed by the user. This can result from the user invoking {@link
   * Cache#invalidate}, {@link Cache#invalidateAll(Iterable)}, {@link Cache#invalidateAll()}, {@link
   * Map#remove}, {@link ConcurrentMap#remove}, or {@link Iterator#remove}.
   */
  EXPLICIT {
    @Override
    boolean wasEvicted() {
      return false;
    }
  },

  
The entry itself was not actually removed, but its value was replaced by the user. This can result from the user invoking Cache.put, LoadingCache.refresh, Map.put, Map.putAll, ConcurrentMap.replace(Object, Object), or ConcurrentMap.replace(Object, Object, Object). /**
   * The entry itself was not actually removed, but its value was replaced by the user. This can
   * result from the user invoking {@link Cache#put}, {@link LoadingCache#refresh}, {@link Map#put},
   * {@link Map#putAll}, {@link ConcurrentMap#replace(Object, Object)}, or {@link
   * ConcurrentMap#replace(Object, Object, Object)}.
   */
  REPLACED {
    @Override
    boolean wasEvicted() {
      return false;
    }
  },

  
The entry was removed automatically because its key or value was garbage-collected. This can occur when using CacheBuilder.weakKeys, CacheBuilder.weakValues, or CacheBuilder.softValues. /**
   * The entry was removed automatically because its key or value was garbage-collected. This can
   * occur when using {@link CacheBuilder#weakKeys}, {@link CacheBuilder#weakValues}, or {@link
   * CacheBuilder#softValues}.
   */
  COLLECTED {
    @Override
    boolean wasEvicted() {
      return true;
    }
  },

  
The entry's expiration timestamp has passed. This can occur when using CacheBuilder.expireAfterWrite or CacheBuilder.expireAfterAccess. /**
   * The entry's expiration timestamp has passed. This can occur when using {@link
   * CacheBuilder#expireAfterWrite} or {@link CacheBuilder#expireAfterAccess}.
   */
  EXPIRED {
    @Override
    boolean wasEvicted() {
      return true;
    }
  },

  
The entry was evicted due to size constraints. This can occur when using CacheBuilder.maximumSize or CacheBuilder.maximumWeight. /**
   * The entry was evicted due to size constraints. This can occur when using {@link
   * CacheBuilder#maximumSize} or {@link CacheBuilder#maximumWeight}.
   */
  SIZE {
    @Override
    boolean wasEvicted() {
      return true;
    }
  };

  
Returns true if there was an automatic removal due to eviction (the cause is neither EXPLICIT nor REPLACED). /**
   * Returns {@code true} if there was an automatic removal due to eviction (the cause is neither
   * {@link #EXPLICIT} nor {@link #REPLACED}).
   */
  abstract boolean wasEvicted();
}