/*
* 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 com.facebook.presto.operator.aggregation;
import com.facebook.presto.spi.function.AccumulatorStateFactory;
import com.facebook.presto.spi.function.AccumulatorStateSerializer;
import com.google.common.base.Throwables;
import java.lang.reflect.Constructor;
import java.util.List;
import java.util.Optional;
import static java.util.Objects.requireNonNull;
public class GenericAccumulatorFactoryBinder
implements AccumulatorFactoryBinder
{
private final AccumulatorStateSerializer<?> stateSerializer;
private final AccumulatorStateFactory<?> stateFactory;
private final Constructor<? extends Accumulator> accumulatorConstructor;
private final Constructor<? extends GroupedAccumulator> groupedAccumulatorConstructor;
public GenericAccumulatorFactoryBinder(
AccumulatorStateSerializer<?> stateSerializer,
AccumulatorStateFactory<?> stateFactory,
Class<? extends Accumulator> accumulatorClass,
Class<? extends GroupedAccumulator> groupedAccumulatorClass)
{
this.stateSerializer = requireNonNull(stateSerializer, "stateSerializer is null");
this.stateFactory = requireNonNull(stateFactory, "stateFactory is null");
try {
accumulatorConstructor = accumulatorClass.getConstructor(
AccumulatorStateSerializer.class,
AccumulatorStateFactory.class,
List.class,
Optional.class);
groupedAccumulatorConstructor = groupedAccumulatorClass.getConstructor(
AccumulatorStateSerializer.class,
AccumulatorStateFactory.class,
List.class,
Optional.class);
}
catch (NoSuchMethodException e) {
throw Throwables.propagate(e);
}
}
@Override
public AccumulatorFactory bind(List<Integer> argumentChannels, Optional<Integer> maskChannel)
{
return new GenericAccumulatorFactory(stateSerializer, stateFactory, accumulatorConstructor, groupedAccumulatorConstructor, argumentChannels, maskChannel);
}
}