com.hazelcast.internal.eviction.impl.strategy.sampling.SamplingBasedEvictionStrategy Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2016, Hazelcast, Inc. 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.hazelcast.internal.eviction.impl.strategy.sampling;
import com.hazelcast.internal.eviction.Evictable;
import com.hazelcast.internal.eviction.EvictionCandidate;
import com.hazelcast.internal.eviction.EvictionListener;
import com.hazelcast.internal.eviction.EvictionPolicyEvaluator;
import com.hazelcast.internal.eviction.EvictionStrategy;
import com.hazelcast.internal.eviction.impl.strategy.AbstractEvictionStrategy;
/**
* Sampling based {@link EvictionStrategy} implementation.
* This strategy select sample {@link Evictable} entries from {@link SampleableEvictableStore}.
*/
public class SamplingBasedEvictionStrategy>
extends AbstractEvictionStrategy {
private static final int SAMPLE_COUNT = 15;
/**
* Processes sampling based eviction logic on {@link SampleableEvictableStore}.
*
* @param sampleableEvictableStore {@link SampleableEvictableStore} that holds {@link Evictable} entries
* @param evictionPolicyEvaluator {@link EvictionPolicyEvaluator} to evaluate
* @param evictionListener {@link EvictionListener} to listen evicted entries
*
* @return evicted entry count
*/
@Override
protected int evictInternal(S sampleableEvictableStore,
EvictionPolicyEvaluator evictionPolicyEvaluator,
EvictionListener evictionListener) {
final Iterable> samples =
sampleableEvictableStore.sample(SAMPLE_COUNT);
final Iterable> evictionCandidates =
evictionPolicyEvaluator.evaluate(samples);
return sampleableEvictableStore.evict(evictionCandidates, evictionListener);
}
}