11d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/* 21d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Copyright (C) 2011 The Guava Authors 31d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 41d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Licensed under the Apache License, Version 2.0 (the "License"); 51d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * you may not use this file except in compliance with the License. 61d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * You may obtain a copy of the License at 71d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 81d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * http://www.apache.org/licenses/LICENSE-2.0 91d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Unless required by applicable law or agreed to in writing, software 111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * distributed under the License is distributed on an "AS IS" BASIS, 121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * See the License for the specific language governing permissions and 141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * limitations under the License. 151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertpackage com.google.common.cache; 181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.annotations.Beta; 201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.base.Preconditions; 211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.collect.ImmutableMap; 221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.util.concurrent.ExecutionException; 241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/** 261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * A cache which forwards all its method calls to another cache. Subclasses should override one or 271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * more methods to modify the behavior of the backing cache as desired per the 281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <a href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>. 291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <p>Note that {@link #get}, {@link #getUnchecked}, and {@link #apply} all expose the same 311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * underlying functionality, so should probably be overridden as a group. 321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @author Charles Fry 341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @since 11.0 351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert@Beta 371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertpublic abstract class ForwardingLoadingCache<K, V> 381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert extends ForwardingCache<K, V> implements LoadingCache<K, V> { 391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** Constructor for use by subclasses. */ 411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert protected ForwardingLoadingCache() {} 421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override 441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert protected abstract LoadingCache<K, V> delegate(); 451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override 471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public V get(K key) throws ExecutionException { 481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return delegate().get(key); 491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override 521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public V getUnchecked(K key) { 531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return delegate().getUnchecked(key); 541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override 571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public ImmutableMap<K, V> getAll(Iterable<? extends K> keys) throws ExecutionException { 581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return delegate().getAll(keys); 591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override 621d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public V apply(K key) { 631d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return delegate().apply(key); 641d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 651d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 661d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override 671d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public void refresh(K key) { 681d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert delegate().refresh(key); 691d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 701d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 711d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 721d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * A simplified version of {@link ForwardingLoadingCache} where subclasses can pass in an already 731d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * constructed {@link LoadingCache} as the delegete. 741d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 751d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @since 10.0 761d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 771d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Beta 781d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public abstract static class SimpleForwardingLoadingCache<K, V> 791d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert extends ForwardingLoadingCache<K, V> { 801d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private final LoadingCache<K, V> delegate; 811d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 821d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert protected SimpleForwardingLoadingCache(LoadingCache<K, V> delegate) { 831d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert this.delegate = Preconditions.checkNotNull(delegate); 841d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 851d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 861d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override 871d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert protected final LoadingCache<K, V> delegate() { 881d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return delegate; 891d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 901d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 911d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert} 92