/*
* 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.cache.simulator.policy.product;
import java.util.Set;
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.trivago.triava.tcache.Cache;
import com.trivago.triava.tcache.TCacheFactory;
import com.trivago.triava.tcache.eviction.EvictionInterface;
import com.trivago.triava.tcache.eviction.LFUEviction;
import com.trivago.triava.tcache.eviction.LRUEviction;
import com.typesafe.config.Config;
/**
* TCache implementation. This library uses high/low watermarks and does not honor a strict bound.
*
* @author ben.manes@gmail.com (Ben Manes)
*/
public final class TCachePolicy implements Policy {
private final Cache<Object, Object> cache;
private final PolicyStats policyStats;
public TCachePolicy(Config config) {
TCacheSettings settings = new TCacheSettings(config);
policyStats = new PolicyStats("product.TCache");
cache = TCacheFactory.standardFactory().builder()
.setMaxElements(settings.maximumSize())
.setEvictionClass(settings.policy())
.setStatistics(true)
.build();
}
/** Returns all variations of this policy based on the configuration parameters. */
public static Set<Policy> policies(Config config) {
return ImmutableSet.of(new TCachePolicy(config));
}
@Override
public void record(long key) {
Object value = cache.get(key);
if (value == null) {
policyStats.recordMiss();
cache.put(key, key);
} else {
policyStats.recordHit();
}
}
@Override
public PolicyStats stats() {
return policyStats;
}
@Override
public void finished() {
cache.close();
policyStats.addEvictions(cache.statistics().getEvictionCount());
}
static final class TCacheSettings extends BasicSettings {
public TCacheSettings(Config config) {
super(config);
}
public <K, V> EvictionInterface<K, V> policy() {
String policy = config().getString("tcache.policy").toLowerCase();
switch (policy) {
case "lfu":
return new LFUEviction<>();
case "lru":
return new LRUEviction<>();
default:
throw new IllegalArgumentException("Unknown policy type: " + policy);
}
}
}
}