io.trino.operator.aggregation.minmaxbyn.MaxByNAggregationFunction Maven / Gradle / Ivy
/*
* 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 io.trino.operator.aggregation.minmaxbyn;
import io.trino.spi.block.BlockBuilder;
import io.trino.spi.block.ValueBlock;
import io.trino.spi.function.AggregationFunction;
import io.trino.spi.function.AggregationState;
import io.trino.spi.function.BlockIndex;
import io.trino.spi.function.BlockPosition;
import io.trino.spi.function.CombineFunction;
import io.trino.spi.function.Description;
import io.trino.spi.function.InputFunction;
import io.trino.spi.function.OutputFunction;
import io.trino.spi.function.SqlNullable;
import io.trino.spi.function.SqlType;
import io.trino.spi.function.TypeParameter;
@AggregationFunction("max_by")
@Description("Returns the values of the first argument associated with the maximum values of the second argument")
public final class MaxByNAggregationFunction
{
private MaxByNAggregationFunction() {}
@InputFunction
@TypeParameter("K")
@TypeParameter("V")
public static void input(
@AggregationState({"K", "V"}) MaxByNState state,
@SqlNullable @BlockPosition @SqlType("V") ValueBlock valueBlock,
@BlockIndex int valuePosition,
@BlockPosition @SqlType("K") ValueBlock keyBlock,
@BlockIndex int keyPosition,
@SqlType("BIGINT") long n)
{
state.initialize(n);
state.add(keyBlock, keyPosition, valueBlock, valuePosition);
}
@CombineFunction
public static void combine(
@AggregationState({"K", "V"}) MaxByNState state,
@AggregationState({"K", "V"}) MaxByNState otherState)
{
state.merge(otherState);
}
@OutputFunction("array(V)")
public static void output(@AggregationState({"K", "V"}) MaxByNState state, BlockBuilder out)
{
state.popAll(out);
}
}