/*
 * Copyright 2017-2023 Crown Copyright
 *
 * 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 uk.gov.gchq.gaffer.sketches.datasketches.sampling.binaryoperator;

import org.apache.datasketches.sampling.ReservoirLongsUnion;

import uk.gov.gchq.koryphe.Since;
import uk.gov.gchq.koryphe.Summary;
import uk.gov.gchq.koryphe.binaryoperator.KorypheBinaryOperator;

/**
 * A {@code ReservoirLongsUnionAggregator} is a {@link java.util.function.BinaryOperator} that aggregates
 * {@link ReservoirLongsUnion}s. It does this by extracting a {@link org.apache.datasketches.sampling.ReservoirLongsSketch}
 * from each {@link ReservoirLongsUnion} and merges that using
 * {@link ReservoirLongsUnion#update(org.apache.datasketches.sampling.ReservoirLongsSketch)}.
 */
@Since("1.0.0")
@Summary("Aggregates ReservoirLongsUnions")
public class ReservoirLongsUnionAggregator extends KorypheBinaryOperator<ReservoirLongsUnion> {

    @Override
    protected ReservoirLongsUnion _apply(final ReservoirLongsUnion a, final ReservoirLongsUnion b) {
        a.update(b.getResult());
        return a;
    }
}
