/*
* 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.client.impl.protocol.task.map;
import com.hazelcast.client.impl.protocol.ClientMessage;
import com.hazelcast.instance.Node;
import com.hazelcast.map.impl.query.AggregationResult;
import com.hazelcast.nio.Connection;
import com.hazelcast.projection.Projection;
import com.hazelcast.query.Predicate;
import com.hazelcast.query.TruePredicate;
import com.hazelcast.util.IterationType;
import java.util.Collection;
public abstract class DefaultMapAggregateMessageTask<P>
extends AbstractMapQueryMessageTask<P,
AggregationResult, AggregationResult, Object> {
public DefaultMapAggregateMessageTask(ClientMessage clientMessage, Node node, Connection connection) {
super(clientMessage, node, connection);
}
@Override
protected IterationType getIterationType() {
return IterationType.ENTRY;
}
@Override
protected Projection<?, ?> getProjection() {
return null;
}
@Override
protected Predicate getPredicate() {
return TruePredicate.INSTANCE;
}
@Override
protected void extractAndAppendResult(Collection<AggregationResult> results, AggregationResult aggregationResult) {
results.add(aggregationResult);
}
@Override
protected Object reduce(Collection<AggregationResult> results) {
if (results.isEmpty()) {
return null;
}
AggregationResult combinedResult = null;
try {
for (AggregationResult result : results) {
if (combinedResult == null) {
combinedResult = result;
} else {
combinedResult.combine(result);
}
}
} finally {
if (combinedResult != null) {
combinedResult.onCombineFinished();
}
}
return combinedResult != null ? combinedResult.getAggregator().aggregate() : null;
}
}