/*
* Copyright 2015 Ben Manes. All Rights Reserved.
*
* 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 com.github.benmanes.caffeine.jcache.integration;
import static java.util.Objects.requireNonNull;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import java.util.stream.Collectors;
import javax.cache.expiry.Duration;
import javax.cache.expiry.ExpiryPolicy;
import javax.cache.integration.CacheLoader;
import javax.cache.integration.CacheLoaderException;
import com.github.benmanes.caffeine.cache.Ticker;
import com.github.benmanes.caffeine.jcache.CacheProxy;
import com.github.benmanes.caffeine.jcache.Expirable;
import com.github.benmanes.caffeine.jcache.event.EventDispatcher;
import com.github.benmanes.caffeine.jcache.management.JCacheStatisticsMXBean;
/**
* An adapter from a JCache cache loader to Caffeine's.
*
* @author ben.manes@gmail.com (Ben Manes)
*/
public final class JCacheLoaderAdapter<K, V>
implements com.github.benmanes.caffeine.cache.CacheLoader<K, Expirable<V>> {
private final JCacheStatisticsMXBean statistics;
private final EventDispatcher<K, V> dispatcher;
private final CacheLoader<K, V> delegate;
private final ExpiryPolicy expiry;
private final Ticker ticker;
private CacheProxy<K, V> cache;
public JCacheLoaderAdapter(CacheLoader<K, V> delegate, EventDispatcher<K, V> dispatcher,
ExpiryPolicy expiry, Ticker ticker, JCacheStatisticsMXBean statistics) {
this.dispatcher = requireNonNull(dispatcher);
this.statistics = requireNonNull(statistics);
this.delegate = requireNonNull(delegate);
this.expiry = requireNonNull(expiry);
this.ticker = requireNonNull(ticker);
}
/**
* Sets the cache instance that was created with this loader.
*
* @param cache the cache that uses this loader
*/
public void setCache(CacheProxy<K, V> cache) {
this.cache = requireNonNull(cache);
}
@Override
public Expirable<V> load(K key) {
try {
boolean statsEnabled = statistics.isEnabled();
long start = statsEnabled ? ticker.read() : 0L;
V value = delegate.load(key);
if (value == null) {
return null;
}
dispatcher.publishCreated(cache, key, value);
if (statsEnabled) {
// Subtracts the load time from the get time
statistics.recordGetTime(start - ticker.read());
}
return new Expirable<>(value, expireTimeMS());
} catch (CacheLoaderException e) {
throw e;
} catch (RuntimeException e) {
throw new CacheLoaderException(e);
}
}
@Override
public Map<K, Expirable<V>> loadAll(Iterable<? extends K> keys) {
try {
boolean statsEnabled = statistics.isEnabled();
long start = statsEnabled ? ticker.read() : 0L;
Map<K, Expirable<V>> result = delegate.loadAll(keys).entrySet().stream()
.filter(entry -> (entry.getKey() != null) && (entry.getValue() != null))
.collect(Collectors.toMap(Map.Entry::getKey,
entry -> new Expirable<>(entry.getValue(), expireTimeMS())));
for (Map.Entry<K, Expirable<V>> entry : result.entrySet()) {
dispatcher.publishCreated(cache, entry.getKey(), entry.getValue().get());
}
if (statsEnabled) {
// Subtracts the load time from the get time
statistics.recordGetTime(start - ticker.read());
}
return result;
} catch (CacheLoaderException e) {
throw e;
} catch (RuntimeException e) {
throw new CacheLoaderException(e);
}
}
private long expireTimeMS() {
try {
Duration duration = expiry.getExpiryForCreation();
if (duration.isZero()) {
return 0;
} else if (duration.isEternal()) {
return Long.MAX_VALUE;
}
long millis = TimeUnit.NANOSECONDS.toMillis(ticker.read());
return duration.getAdjustedTime(millis);
} catch (Exception e) {
return Long.MAX_VALUE;
}
}
}