12a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)/* 22a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) * Copyright (C) 2011 The Guava Authors 32a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) * 42a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) * Licensed under the Apache License, Version 2.0 (the "License"); 52a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) * you may not use this file except in compliance with the License. 62a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) * You may obtain a copy of the License at 7c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) * 8c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) * http://www.apache.org/licenses/LICENSE-2.0 92a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) * 1090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) * Unless required by applicable law or agreed to in writing, software 112a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) * distributed under the License is distributed on an "AS IS" BASIS, 122a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 132a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) * See the License for the specific language governing permissions and 142a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) * limitations under the License. 1590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) */ 162a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 172a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)package com.google.common.cache; 182a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 192a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)import com.google.common.annotations.Beta; 202a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 212a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)/** 222a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) * An object that can receive a notification when an entry is removed from a cache. The removal 232a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) * resulting in notification could have occured to an entry being manually removed or replaced, or 2490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) * due to eviction resulting from timed expiration, exceeding a maximum size, or garbage 2590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) * collection. 2690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) * 272a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) * <p>An instance may be called concurrently by multiple threads to process different entries. 282a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) * Implementations of this interface should avoid performing blocking calls or synchronizing on 292a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) * shared resources. 302a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) * 312a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) * @param <K> the most general type of keys this listener can listen for; for 322a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) * example {@code Object} if any key is acceptable 33c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) * @param <V> the most general type of values this listener can listen for; for 34c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) * example {@code Object} if any key is acceptable 35c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) * @author Charles Fry 362a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) * @since 10.0 372a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) */ 3890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)@Beta 39c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles)public interface RemovalListener<K, V> { 40c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) /** 412a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) * Notifies the listener that a removal occurred at some point in the past. 42 */ 43 // Technically should accept RemovalNotification<? extends K, ? extends V>, but because 44 // RemovalNotification is guaranteed covariant, let's make users' lives simpler. 45 void onRemoval(RemovalNotification<K, V> notification); 46} 47