com.hazelcast.internal.eviction.EvictionPolicyEvaluatorProvider 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;
import com.hazelcast.internal.eviction.impl.evaluator.LFUEvictionPolicyEvaluator;
import com.hazelcast.internal.eviction.impl.evaluator.LRUEvictionPolicyEvaluator;
import java.util.HashMap;
import java.util.Map;
/**
* Provider to get any kind ({@link EvictionPolicyType}) of {@link EvictionPolicyEvaluator}.
*/
public final class EvictionPolicyEvaluatorProvider {
private static final Map EVICTION_POLICY_EVALUATOR_MAP =
new HashMap();
static {
init();
}
private EvictionPolicyEvaluatorProvider() {
}
private static void init() {
EVICTION_POLICY_EVALUATOR_MAP.put(EvictionPolicyType.LRU, new LRUEvictionPolicyEvaluator());
EVICTION_POLICY_EVALUATOR_MAP.put(EvictionPolicyType.LFU, new LFUEvictionPolicyEvaluator());
}
/**
* Gets the {@link EvictionPolicyEvaluator} implementation specified with evictionPolicy.
*
* @param evictionConfig {@link EvictionConfiguration} for requested {@link EvictionPolicyEvaluator} implementation
*
* @return the requested {@link EvictionPolicyEvaluator} implementation
*/
public static EvictionPolicyEvaluator getEvictionPolicyEvaluator(EvictionConfiguration evictionConfig) {
if (evictionConfig == null) {
return null;
}
final EvictionPolicyType evictionPolicyType = evictionConfig.getEvictionPolicyType();
if (evictionPolicyType == null) {
return null;
}
final EvictionPolicyEvaluator evictionPolicyEvaluator =
EVICTION_POLICY_EVALUATOR_MAP.get(evictionPolicyType);
if (evictionPolicyEvaluator != null) {
return evictionPolicyEvaluator;
} else {
throw new IllegalArgumentException("Unsupported eviction policy type: " + evictionPolicyType);
}
// TODO "evictionPolicyEvaluatorFactory" can be handled here from a single point
// for user defined custom implementations.
// So "EvictionPolicyEvaluator" implementation can be taken from user defined factory.
}
}