io.trino.operator.aggregation.MergeHyperLogLogAggregation 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;
import io.airlift.slice.Slice;
import io.airlift.stats.cardinality.HyperLogLog;
import io.trino.operator.aggregation.state.HyperLogLogState;
import io.trino.operator.aggregation.state.StateCompiler;
import io.trino.spi.block.BlockBuilder;
import io.trino.spi.function.AccumulatorStateSerializer;
import io.trino.spi.function.AggregationFunction;
import io.trino.spi.function.AggregationState;
import io.trino.spi.function.CombineFunction;
import io.trino.spi.function.InputFunction;
import io.trino.spi.function.OutputFunction;
import io.trino.spi.function.SqlType;
import io.trino.spi.type.StandardTypes;
@AggregationFunction("merge")
public final class MergeHyperLogLogAggregation
{
private static final AccumulatorStateSerializer serializer = StateCompiler.generateStateSerializer(HyperLogLogState.class);
private MergeHyperLogLogAggregation() {}
@InputFunction
public static void input(@AggregationState HyperLogLogState state, @SqlType(StandardTypes.HYPER_LOG_LOG) Slice value)
{
HyperLogLog input = HyperLogLog.newInstance(value);
merge(state, input);
}
@CombineFunction
public static void combine(@AggregationState HyperLogLogState state, @AggregationState HyperLogLogState otherState)
{
merge(state, otherState.getHyperLogLog());
}
private static void merge(@AggregationState HyperLogLogState state, HyperLogLog input)
{
HyperLogLog previous = state.getHyperLogLog();
if (previous == null) {
state.setHyperLogLog(input);
state.addMemoryUsage(input.estimatedInMemorySize());
}
else {
state.addMemoryUsage(-previous.estimatedInMemorySize());
previous.mergeWith(input);
state.addMemoryUsage(previous.estimatedInMemorySize());
}
}
@OutputFunction(StandardTypes.HYPER_LOG_LOG)
public static void output(@AggregationState HyperLogLogState state, BlockBuilder out)
{
serializer.serialize(state, out);
}
}