org.springframework.cache.support.NoOpCacheManager.java Source code

Introduction

Here is the source code for org.springframework.cache.support.NoOpCacheManager.java

Source

/*
 * 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
 *
 *      https://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.support;

import java.util.Collection;
import java.util.Collections;
import java.util.LinkedHashSet;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

import org.springframework.cache.Cache;
import org.springframework.cache.CacheManager;
import org.springframework.lang.Nullable;

/**
 * A basic, no operation {@link CacheManager} implementation suitable
 * for disabling caching, typically used for backing cache declarations
 * without an actual backing store.
 *
 * <p>Will simply accept any items into the cache not actually storing them.
 *
 * @author Costin Leau
 * @author Stephane Nicoll
 * @since 3.1
 * @see CompositeCacheManager
 */
public class NoOpCacheManager implements CacheManager {

    private final ConcurrentMap<String, Cache> caches = new ConcurrentHashMap<>(16);

    private final Set<String> cacheNames = new LinkedHashSet<>(16);

    /**
     * This implementation always returns a {@link Cache} implementation that will not store items.
     * Additionally, the request cache will be remembered by the manager for consistency.
     */
    @Override
    @Nullable
    public Cache getCache(String name) {
        Cache cache = this.caches.get(name);
        if (cache == null) {
            this.caches.computeIfAbsent(name, key -> new NoOpCache(name));
            synchronized (this.cacheNames) {
                this.cacheNames.add(name);
            }
        }

        return this.caches.get(name);
    }

    /**
     * This implementation returns the name of the caches previously requested.
     */
    @Override
    public Collection<String> getCacheNames() {
        synchronized (this.cacheNames) {
            return Collections.unmodifiableSet(this.cacheNames);
        }
    }

}