/*
* Copyright 2016 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.cache.simulator.policy.product;
import static com.google.common.base.Preconditions.checkState;
import java.util.Set;
import org.elasticsearch.common.cache.Cache;
import org.elasticsearch.common.cache.Cache.CacheStats;
import org.elasticsearch.common.cache.CacheBuilder;
import com.github.benmanes.caffeine.cache.simulator.BasicSettings;
import com.github.benmanes.caffeine.cache.simulator.policy.Policy;
import com.github.benmanes.caffeine.cache.simulator.policy.PolicyStats;
import com.google.common.collect.ImmutableSet;
import com.typesafe.config.Config;
/**
* ElasticSearch's LRU cache.
*
* @author ben.manes@gmail.com (Ben Manes)
*/
public final class ElasticSearchPolicy implements Policy {
private final Cache<Object, Object> cache;
private final PolicyStats policyStats;
private final int maximumSize;
public ElasticSearchPolicy(Config config) {
policyStats = new PolicyStats("product.ElasticSearch");
BasicSettings settings = new BasicSettings(config);
maximumSize = settings.maximumSize();
cache = CacheBuilder.builder()
.setMaximumWeight(maximumSize)
.build();
}
/** Returns all variations of this policy based on the configuration parameters. */
public static Set<Policy> policies(Config config) {
return ImmutableSet.of(new ElasticSearchPolicy(config));
}
@Override
public void record(long key) {
Object value = cache.get(key);
if (value == null) {
if (cache.count() == maximumSize) {
policyStats.recordEviction();
}
cache.put(key, key);
policyStats.recordMiss();
} else {
policyStats.recordHit();
}
}
@Override
public PolicyStats stats() {
return policyStats;
}
@Override
public void finished() {
CacheStats stats = cache.stats();
checkState(policyStats.hitCount() == stats.getHits());
checkState(policyStats.missCount() == stats.getMisses());
checkState(policyStats.evictionCount() == stats.getEvictions());
}
}