DefaultCacheManager.java
- /*
- * *********************************************************************************************************************
- *
- * blueMarine II: Semantic Media Centre
- * http://tidalwave.it/projects/bluemarine2
- *
- * Copyright (C) 2015 - 2021 by Tidalwave s.a.s. (http://tidalwave.it)
- *
- * *********************************************************************************************************************
- *
- * 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.
- *
- * *********************************************************************************************************************
- *
- * git clone https://bitbucket.org/tidalwave/bluemarine2-src
- * git clone https://github.com/tidalwave-it/bluemarine2-src
- *
- * *********************************************************************************************************************
- */
- package it.tidalwave.bluemarine2.model.impl;
- import javax.annotation.Nonnull;
- import java.util.Map;
- import java.util.concurrent.ConcurrentHashMap;
- import java.util.function.Supplier;
- import java.lang.ref.SoftReference;
- import it.tidalwave.messagebus.annotation.ListensTo;
- import it.tidalwave.messagebus.annotation.SimpleMessageSubscriber;
- import it.tidalwave.bluemarine2.message.PersistenceInitializedNotification;
- import it.tidalwave.bluemarine2.model.spi.CacheManager;
- import lombok.extern.slf4j.Slf4j;
- import lombok.RequiredArgsConstructor;
- import static java.util.Objects.*;
- /***********************************************************************************************************************
- *
- * @author Fabrizio Giudici
- *
- **********************************************************************************************************************/
- @Slf4j @SimpleMessageSubscriber
- public class DefaultCacheManager implements CacheManager
- {
- private final Map<Object, Cache> cacheMap = new ConcurrentHashMap<>();
- @RequiredArgsConstructor
- static class DefaultCache implements Cache
- {
- @Nonnull
- private final String name;
- // TODO: use Spring ConcurrentReferenceHashMap?
- private final Map<Object, SoftReference<?>> objectMap = new ConcurrentHashMap<>();
- @Override @Nonnull
- public <T> T getCachedObject (@Nonnull final Object key, @Nonnull final Supplier<T> supplier)
- {
- SoftReference<T> ref = (SoftReference<T>)(objectMap.computeIfAbsent(key, k -> computeObject(k, supplier)));
- T object = ref.get();
- if (object == null)
- {
- objectMap.put(key, ref = computeObject(key, supplier));
- object = requireNonNull(ref.get(), "Cache returned null");
- }
- return object;
- }
- @Nonnull
- private <T> SoftReference<T> computeObject (@Nonnull final Object key, @Nonnull final Supplier<T> supplier)
- {
- log.info(">>>> cache {} miss for {}", name, key);
- return new SoftReference<>(requireNonNull(supplier.get(), "Supplier returned null"));
- }
- }
- @Override @Nonnull
- public Cache getCache (@Nonnull final Object cacheKey)
- {
- return cacheMap.computeIfAbsent(cacheKey, key -> new DefaultCache(cacheKey.toString()));
- }
- /* visible for testing FIXME */ public void onPersistenceUpdated (@ListensTo final PersistenceInitializedNotification notification)
- {
- log.debug("onPersistenceUpdated({})", notification);
- cacheMap.clear();
- }
- }