com.hazelcast.map.impl.PartitioningStrategyFactory Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2020, 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.map.impl;
import com.hazelcast.config.PartitioningStrategyConfig;
import com.hazelcast.partition.PartitioningStrategy;
import com.hazelcast.internal.nio.ClassLoaderUtil;
import com.hazelcast.internal.util.ExceptionUtil;
import java.util.concurrent.ConcurrentHashMap;
/**
* Factory for {@link PartitioningStrategy} instances.
*/
public final class PartitioningStrategyFactory {
// not private for tests
final ConcurrentHashMap cache = new ConcurrentHashMap<>();
// this is set to the current NodeEngine.getConfigClassLoader
private final ClassLoader configClassLoader;
/**
* Construct a new PartitioningStrategyFactory
* @param configClassLoader the current {@code NodeEngine}'s {@code configClassLoader}.
*/
public PartitioningStrategyFactory(ClassLoader configClassLoader) {
this.configClassLoader = configClassLoader;
}
/**
* Obtain a {@link PartitioningStrategy} for the given {@code NodeEngine} and {@code mapName}. This method
* first attempts locating a {@link PartitioningStrategy} in {code config.getPartitioningStrategy()}. If this is {@code null},
* then looks up its internal cache of partitioning strategies; if one has already been created for the given
* {@code mapName}, it is returned, otherwise it is instantiated, cached and returned.
* @param mapName Map for which this partitioning strategy is being created
* @param config the partitioning strategy configuration
* @return
*/
public PartitioningStrategy getPartitioningStrategy(String mapName, PartitioningStrategyConfig config) {
PartitioningStrategy strategy = null;
if (config != null) {
strategy = config.getPartitioningStrategy();
if (strategy == null) {
if (cache.containsKey(mapName)) {
strategy = cache.get(mapName);
} else if (config.getPartitioningStrategyClass() != null) {
try {
strategy = ClassLoaderUtil.newInstance(configClassLoader, config.getPartitioningStrategyClass());
cache.put(mapName, strategy);
} catch (Exception e) {
throw ExceptionUtil.rethrow(e);
}
}
}
}
return strategy;
}
/**
* Remove the cached {@code PartitioningStrategy} from the internal cache, if it exists.
* @param mapName name of the map whose partitioning strategy will be removed from internal cache
*/
public void removePartitioningStrategyFromCache(String mapName) {
cache.remove(mapName);
}
}