1 /* 2 * Copyright (C) 2011 The Guava Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except 5 * in compliance with the License. You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software distributed under the License 10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express 11 * or implied. See the License for the specific language governing permissions and limitations under 12 * the License. 13 */ 14 15 package com.google.common.cache; 16 17 import java.util.concurrent.ConcurrentLinkedQueue; 18 import java.util.concurrent.atomic.AtomicInteger; 19 20 /** 21 * Utility {@link RemovalListener} implementations intended for use in testing. 22 * 23 * @author mike nonemacher 24 */ 25 class TestingRemovalListeners { 26 27 /** 28 * Returns a new no-op {@code RemovalListener}. 29 */ nullRemovalListener()30 static <K, V> NullRemovalListener<K, V> nullRemovalListener() { 31 return new NullRemovalListener<K, V>(); 32 } 33 34 /** 35 * Type-inferring factory method for creating a {@link QueuingRemovalListener}. 36 */ queuingRemovalListener()37 static <K, V> QueuingRemovalListener<K, V> queuingRemovalListener() { 38 return new QueuingRemovalListener<K,V>(); 39 } 40 41 /** 42 * Type-inferring factory method for creating a {@link CountingRemovalListener}. 43 */ countingRemovalListener()44 static <K, V> CountingRemovalListener<K, V> countingRemovalListener() { 45 return new CountingRemovalListener<K,V>(); 46 } 47 48 /** 49 * {@link RemovalListener} that adds all {@link RemovalNotification} objects to a queue. 50 */ 51 static class QueuingRemovalListener<K, V> 52 extends ConcurrentLinkedQueue<RemovalNotification<K, V>> implements RemovalListener<K, V> { 53 54 @Override onRemoval(RemovalNotification<K, V> notification)55 public void onRemoval(RemovalNotification<K, V> notification) { 56 add(notification); 57 } 58 } 59 60 /** 61 * {@link RemovalListener} that counts each {@link RemovalNotification} it receives, and provides 62 * access to the most-recently received one. 63 */ 64 static class CountingRemovalListener<K, V> implements RemovalListener<K, V> { 65 private final AtomicInteger count = new AtomicInteger(); 66 private volatile RemovalNotification<K, V> lastNotification; 67 68 @Override onRemoval(RemovalNotification<K, V> notification)69 public void onRemoval(RemovalNotification<K, V> notification) { 70 count.incrementAndGet(); 71 lastNotification = notification; 72 } 73 getCount()74 public int getCount() { 75 return count.get(); 76 } 77 getLastEvictedKey()78 public K getLastEvictedKey() { 79 return lastNotification.getKey(); 80 } 81 getLastEvictedValue()82 public V getLastEvictedValue() { 83 return lastNotification.getValue(); 84 } 85 getLastNotification()86 public RemovalNotification<K, V> getLastNotification() { 87 return lastNotification; 88 } 89 } 90 91 /** 92 * No-op {@link RemovalListener}. 93 */ 94 static class NullRemovalListener<K, V> implements RemovalListener<K, V> { 95 @Override onRemoval(RemovalNotification<K, V> notification)96 public void onRemoval(RemovalNotification<K, V> notification) {} 97 } 98 } 99