001/*
002 * Copyright 2002-2020 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.cache.caffeine;
018
019import java.util.concurrent.Callable;
020import java.util.function.Function;
021
022import com.github.benmanes.caffeine.cache.LoadingCache;
023
024import org.springframework.cache.support.AbstractValueAdaptingCache;
025import org.springframework.lang.UsesJava8;
026import org.springframework.util.Assert;
027
028/**
029 * Spring {@link org.springframework.cache.Cache} adapter implementation
030 * on top of a Caffeine {@link com.github.benmanes.caffeine.cache.Cache} instance.
031 *
032 * <p>Requires Caffeine 2.1 or higher.
033 *
034 * @author Ben Manes
035 * @author Juergen Hoeller
036 * @author Stephane Nicoll
037 * @since 4.3
038 * @see CaffeineCacheManager
039 */
040@UsesJava8
041public class CaffeineCache extends AbstractValueAdaptingCache {
042
043        private final String name;
044
045        private final com.github.benmanes.caffeine.cache.Cache<Object, Object> cache;
046
047
048        /**
049         * Create a {@link CaffeineCache} instance with the specified name and the
050         * given internal {@link com.github.benmanes.caffeine.cache.Cache} to use.
051         * @param name the name of the cache
052         * @param cache the backing Caffeine Cache instance
053         */
054        public CaffeineCache(String name, com.github.benmanes.caffeine.cache.Cache<Object, Object> cache) {
055                this(name, cache, true);
056        }
057
058        /**
059         * Create a {@link CaffeineCache} instance with the specified name and the
060         * given internal {@link com.github.benmanes.caffeine.cache.Cache} to use.
061         * @param name the name of the cache
062         * @param cache the backing Caffeine Cache instance
063         * @param allowNullValues whether to accept and convert {@code null}
064         * values for this cache
065         */
066        public CaffeineCache(String name, com.github.benmanes.caffeine.cache.Cache<Object, Object> cache,
067                        boolean allowNullValues) {
068
069                super(allowNullValues);
070                Assert.notNull(name, "Name must not be null");
071                Assert.notNull(cache, "Cache must not be null");
072                this.name = name;
073                this.cache = cache;
074        }
075
076
077        @Override
078        public final String getName() {
079                return this.name;
080        }
081
082        @Override
083        public final com.github.benmanes.caffeine.cache.Cache<Object, Object> getNativeCache() {
084                return this.cache;
085        }
086
087        @Override
088        public ValueWrapper get(Object key) {
089                if (this.cache instanceof LoadingCache) {
090                        Object value = ((LoadingCache<Object, Object>) this.cache).get(key);
091                        return toValueWrapper(value);
092                }
093                return super.get(key);
094        }
095
096        @SuppressWarnings("unchecked")
097        @Override
098        public <T> T get(Object key, final Callable<T> valueLoader) {
099                return (T) fromStoreValue(this.cache.get(key, new LoadFunction(valueLoader)));
100        }
101
102        @Override
103        protected Object lookup(Object key) {
104                return this.cache.getIfPresent(key);
105        }
106
107        @Override
108        public void put(Object key, Object value) {
109                this.cache.put(key, toStoreValue(value));
110        }
111
112        @Override
113        public ValueWrapper putIfAbsent(Object key, final Object value) {
114                PutIfAbsentFunction callable = new PutIfAbsentFunction(value);
115                Object result = this.cache.get(key, callable);
116                return (callable.called ? null : toValueWrapper(result));
117        }
118
119        @Override
120        public void evict(Object key) {
121                this.cache.invalidate(key);
122        }
123
124        @Override
125        public void clear() {
126                this.cache.invalidateAll();
127        }
128
129
130        private class PutIfAbsentFunction implements Function<Object, Object> {
131
132                private final Object value;
133
134                private boolean called;
135
136                public PutIfAbsentFunction(Object value) {
137                        this.value = value;
138                }
139
140                @Override
141                public Object apply(Object key) {
142                        this.called = true;
143                        return toStoreValue(this.value);
144                }
145        }
146
147
148        private class LoadFunction implements Function<Object, Object> {
149
150                private final Callable<?> valueLoader;
151
152                public LoadFunction(Callable<?> valueLoader) {
153                        this.valueLoader = valueLoader;
154                }
155
156                @Override
157                public Object apply(Object o) {
158                        try {
159                                return toStoreValue(valueLoader.call());
160                        }
161                        catch (Exception ex) {
162                                throw new ValueRetrievalException(o, valueLoader, ex);
163                        }
164                }
165        }
166
167}