/*
* Copyright (c) 2008-2017, 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.cache.merge;
import com.hazelcast.cache.CacheEntryView;
import com.hazelcast.cache.StorageTypeAwareCacheMergePolicy;
import com.hazelcast.nio.serialization.BinaryInterface;
/**
* `PassThroughCacheMergePolicy` policy merges cache entry from source to destination
* if it does not exist in the destination cache.
*/
@BinaryInterface
public class PutIfAbsentCacheMergePolicy
implements StorageTypeAwareCacheMergePolicy {
public PutIfAbsentCacheMergePolicy() {
}
@Override
public Object merge(String cacheName, CacheEntryView mergingEntry, CacheEntryView existingEntry) {
if (existingEntry == null) {
return mergingEntry.getValue();
}
return existingEntry.getValue();
}
}