001/* 002 * Copyright (C) 2011 The Guava Authors 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except 005 * in compliance with the License. You may obtain a copy of the License at 006 * 007 * http://www.apache.org/licenses/LICENSE-2.0 008 * 009 * Unless required by applicable law or agreed to in writing, software distributed under the License 010 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express 011 * or implied. See the License for the specific language governing permissions and limitations under 012 * the License. 013 */ 014 015package com.google.common.cache; 016 017import com.google.common.annotations.GwtCompatible; 018import java.util.Iterator; 019import java.util.Map; 020import java.util.concurrent.ConcurrentMap; 021 022/** 023 * The reason why a cached entry was removed. 024 * 025 * @author Charles Fry 026 * @since 10.0 027 */ 028@GwtCompatible 029public enum RemovalCause { 030 /** 031 * The entry was manually removed by the user. This can result from the user invoking {@link 032 * Cache#invalidate}, {@link Cache#invalidateAll(Iterable)}, {@link Cache#invalidateAll()}, {@link 033 * Map#remove}, {@link ConcurrentMap#remove}, or {@link Iterator#remove}. 034 */ 035 EXPLICIT { 036 @Override 037 boolean wasEvicted() { 038 return false; 039 } 040 }, 041 042 /** 043 * The entry itself was not actually removed, but its value was replaced by the user. This can 044 * result from the user invoking {@link Cache#put}, {@link LoadingCache#refresh}, {@link Map#put}, 045 * {@link Map#putAll}, {@link ConcurrentMap#replace(Object, Object)}, or {@link 046 * ConcurrentMap#replace(Object, Object, Object)}. 047 */ 048 REPLACED { 049 @Override 050 boolean wasEvicted() { 051 return false; 052 } 053 }, 054 055 /** 056 * The entry was removed automatically because its key or value was garbage-collected. This can 057 * occur when using {@link CacheBuilder#weakKeys}, {@link CacheBuilder#weakValues}, or {@link 058 * CacheBuilder#softValues}. 059 */ 060 COLLECTED { 061 @Override 062 boolean wasEvicted() { 063 return true; 064 } 065 }, 066 067 /** 068 * The entry's expiration timestamp has passed. This can occur when using {@link 069 * CacheBuilder#expireAfterWrite} or {@link CacheBuilder#expireAfterAccess}. 070 */ 071 EXPIRED { 072 @Override 073 boolean wasEvicted() { 074 return true; 075 } 076 }, 077 078 /** 079 * The entry was evicted due to size constraints. This can occur when using {@link 080 * CacheBuilder#maximumSize} or {@link CacheBuilder#maximumWeight}. 081 */ 082 SIZE { 083 @Override 084 boolean wasEvicted() { 085 return true; 086 } 087 }; 088 089 /** 090 * Returns {@code true} if there was an automatic removal due to eviction (the cause is neither 091 * {@link #EXPLICIT} nor {@link #REPLACED}). 092 */ 093 abstract boolean wasEvicted(); 094}