com.hazelcast.spi.merge.PutIfAbsentMergePolicy Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2018, 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.spi.merge;
import com.hazelcast.spi.annotation.Beta;
import com.hazelcast.spi.impl.merge.AbstractSplitBrainMergePolicy;
import com.hazelcast.spi.impl.merge.SplitBrainDataSerializerHook;
/**
* Merges data structure entries from source to destination if they don't exist in the destination data structure.
*
* @param the type of the merged value
* @param the type of the merging value
* @since 3.10
*/
@Beta
public class PutIfAbsentMergePolicy> extends AbstractSplitBrainMergePolicy {
public PutIfAbsentMergePolicy() {
}
@Override
public V merge(T mergingValue, T existingValue) {
if (existingValue == null) {
return mergingValue.getValue();
}
return existingValue.getValue();
}
@Override
public int getId() {
return SplitBrainDataSerializerHook.PUT_IF_ABSENT;
}
}