/*
* Copyright 2002-2016 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.cache.caffeine;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import com.github.benmanes.caffeine.cache.CacheLoader;
import com.github.benmanes.caffeine.cache.Caffeine;
import com.github.benmanes.caffeine.cache.CaffeineSpec;
import org.springframework.cache.Cache;
import org.springframework.cache.CacheManager;
import org.springframework.util.Assert;
import org.springframework.util.ObjectUtils;
/**
* {@link CacheManager} implementation that lazily builds {@link CaffeineCache}
* instances for each {@link #getCache} request. Also supports a 'static' mode
* where the set of cache names is pre-defined through {@link #setCacheNames},
* with no dynamic creation of further cache regions at runtime.
*
* <p>The configuration of the underlying cache can be fine-tuned through a
* {@link Caffeine} builder or {@link CaffeineSpec}, passed into this
* CacheManager through {@link #setCaffeine}/{@link #setCaffeineSpec}.
* A {@link CaffeineSpec}-compliant expression value can also be applied
* via the {@link #setCacheSpecification "cacheSpecification"} bean property.
*
* <p>Requires Caffeine 2.1 or higher.
*
* @author Ben Manes
* @author Juergen Hoeller
* @author Stephane Nicoll
* @since 4.3
* @see CaffeineCache
*/
public class CaffeineCacheManager implements CacheManager {
private final ConcurrentMap<String, Cache> cacheMap = new ConcurrentHashMap<>(16);
private boolean dynamic = true;
private Caffeine<Object, Object> cacheBuilder = Caffeine.newBuilder();
private CacheLoader<Object, Object> cacheLoader;
private boolean allowNullValues = true;
/**
* Construct a dynamic CaffeineCacheManager,
* lazily creating cache instances as they are being requested.
*/
public CaffeineCacheManager() {
}
/**
* Construct a static CaffeineCacheManager,
* managing caches for the specified cache names only.
*/
public CaffeineCacheManager(String... cacheNames) {
setCacheNames(Arrays.asList(cacheNames));
}
/**
* Specify the set of cache names for this CacheManager's 'static' mode.
* <p>The number of caches and their names will be fixed after a call to this method,
* with no creation of further cache regions at runtime.
* <p>Calling this with a {@code null} collection argument resets the
* mode to 'dynamic', allowing for further creation of caches again.
*/
public void setCacheNames(Collection<String> cacheNames) {
if (cacheNames != null) {
for (String name : cacheNames) {
this.cacheMap.put(name, createCaffeineCache(name));
}
this.dynamic = false;
}
else {
this.dynamic = true;
}
}
/**
* Set the Caffeine to use for building each individual
* {@link CaffeineCache} instance.
* @see #createNativeCaffeineCache
* @see com.github.benmanes.caffeine.cache.Caffeine#build()
*/
public void setCaffeine(Caffeine<Object, Object> caffeine) {
Assert.notNull(caffeine, "Caffeine must not be null");
doSetCaffeine(caffeine);
}
/**
* Set the {@link CaffeineSpec} to use for building each individual
* {@link CaffeineCache} instance.
* @see #createNativeCaffeineCache
* @see com.github.benmanes.caffeine.cache.Caffeine#from(CaffeineSpec)
*/
public void setCaffeineSpec(CaffeineSpec caffeineSpec) {
doSetCaffeine(Caffeine.from(caffeineSpec));
}
/**
* Set the Caffeine cache specification String to use for building each
* individual {@link CaffeineCache} instance. The given value needs to
* comply with Caffeine's {@link CaffeineSpec} (see its javadoc).
* @see #createNativeCaffeineCache
* @see com.github.benmanes.caffeine.cache.Caffeine#from(String)
*/
public void setCacheSpecification(String cacheSpecification) {
doSetCaffeine(Caffeine.from(cacheSpecification));
}
/**
* Set the Caffeine CacheLoader to use for building each individual
* {@link CaffeineCache} instance, turning it into a LoadingCache.
* @see #createNativeCaffeineCache
* @see com.github.benmanes.caffeine.cache.Caffeine#build(CacheLoader)
* @see com.github.benmanes.caffeine.cache.LoadingCache
*/
public void setCacheLoader(CacheLoader<Object, Object> cacheLoader) {
if (!ObjectUtils.nullSafeEquals(this.cacheLoader, cacheLoader)) {
this.cacheLoader = cacheLoader;
refreshKnownCaches();
}
}
/**
* Specify whether to accept and convert {@code null} values for all caches
* in this cache manager.
* <p>Default is "true", despite Caffeine itself not supporting {@code null} values.
* An internal holder object will be used to store user-level {@code null}s.
*/
public void setAllowNullValues(boolean allowNullValues) {
if (this.allowNullValues != allowNullValues) {
this.allowNullValues = allowNullValues;
refreshKnownCaches();
}
}
/**
* Return whether this cache manager accepts and converts {@code null} values
* for all of its caches.
*/
public boolean isAllowNullValues() {
return this.allowNullValues;
}
@Override
public Collection<String> getCacheNames() {
return Collections.unmodifiableSet(this.cacheMap.keySet());
}
@Override
public Cache getCache(String name) {
Cache cache = this.cacheMap.get(name);
if (cache == null && this.dynamic) {
synchronized (this.cacheMap) {
cache = this.cacheMap.get(name);
if (cache == null) {
cache = createCaffeineCache(name);
this.cacheMap.put(name, cache);
}
}
}
return cache;
}
/**
* Create a new CaffeineCache instance for the specified cache name.
* @param name the name of the cache
* @return the Spring CaffeineCache adapter (or a decorator thereof)
*/
protected Cache createCaffeineCache(String name) {
return new CaffeineCache(name, createNativeCaffeineCache(name), isAllowNullValues());
}
/**
* Create a native Caffeine Cache instance for the specified cache name.
* @param name the name of the cache
* @return the native Caffeine Cache instance
*/
protected com.github.benmanes.caffeine.cache.Cache<Object, Object> createNativeCaffeineCache(String name) {
if (this.cacheLoader != null) {
return this.cacheBuilder.build(this.cacheLoader);
}
else {
return this.cacheBuilder.build();
}
}
private void doSetCaffeine(Caffeine<Object, Object> cacheBuilder) {
if (!ObjectUtils.nullSafeEquals(this.cacheBuilder, cacheBuilder)) {
this.cacheBuilder = cacheBuilder;
refreshKnownCaches();
}
}
/**
* Create the known caches again with the current state of this manager.
*/
private void refreshKnownCaches() {
for (Map.Entry<String, Cache> entry : this.cacheMap.entrySet()) {
entry.setValue(createCaffeineCache(entry.getKey()));
}
}
}