/*
* 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.Beta;
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
*/
@Beta
public enum RemovalCause {
/**
* The entry was manually removed by the user. This can result from the user invoking {@link
* Cache#invalidate}, {@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 {@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 {@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 {@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 {@link
* CacheBuilder#maximumSize}.
*/
SIZE {
@Override
boolean wasEvicted() {
return true;
}
};
/**
* Returns {@code true} if there was an automatic removal due to eviction (the cause is neither
* {@link #EXPLICIT} nor {@link #REPLACED}).
*/
abstract boolean wasEvicted();
}
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