/**
 * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The ASF licenses this file to you 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 org.apache.storm.trident.state;

import java.util.List;
import org.apache.storm.trident.operation.ReducerAggregator;
import org.apache.storm.trident.tuple.TridentTuple;

public class ReducerValueUpdater implements ValueUpdater<Object> {
    List<TridentTuple> tuples;
    ReducerAggregator agg;

    public ReducerValueUpdater(ReducerAggregator agg, List<TridentTuple> tuples) {
        this.agg = agg;
        this.tuples = tuples;
    }

    @Override
    public Object update(Object stored) {
        Object ret = (stored == null) ? this.agg.init() : stored;
        for (TridentTuple t : tuples) {
            ret = this.agg.reduce(ret, t);
        }
        return ret;
    }
}
