io.trino.operator.aggregation.arrayagg.ArrayAggregationFunction 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.arrayagg;
import io.trino.spi.block.ArrayBlockBuilder;
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;
import io.trino.spi.type.Type;
@AggregationFunction(value = "array_agg", isOrderSensitive = true)
@Description("return an array of values")
public final class ArrayAggregationFunction
{
private ArrayAggregationFunction() {}
@InputFunction
@TypeParameter("T")
public static void input(
@AggregationState("T") ArrayAggregationState state,
@SqlNullable @BlockPosition @SqlType("T") ValueBlock value,
@BlockIndex int position)
{
state.add(value, position);
}
@CombineFunction
public static void combine(
@AggregationState("T") ArrayAggregationState state,
@AggregationState("T") ArrayAggregationState otherState)
{
state.merge(otherState);
}
@OutputFunction("array(T)")
public static void output(
@TypeParameter("T") Type elementType,
@AggregationState("T") ArrayAggregationState state,
BlockBuilder out)
{
if (state.isEmpty()) {
out.appendNull();
}
else {
((ArrayBlockBuilder) out).buildEntry(state::writeAll);
}
}
}