/*
* 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 com.google.common.collect.ImmutableList;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.util.List;
import java.util.Optional;
import static java.util.Objects.requireNonNull;
public class GenericAccumulatorFactory
implements AccumulatorFactory
{
private final AccumulatorStateSerializer<?> stateSerializer;
private final AccumulatorStateFactory<?> stateFactory;
private final Constructor<? extends Accumulator> accumulatorConstructor;
private final Constructor<? extends GroupedAccumulator> groupedAccumulatorConstructor;
private final Optional<Integer> maskChannel;
private final List<Integer> inputChannels;
public GenericAccumulatorFactory(
AccumulatorStateSerializer<?> stateSerializer,
AccumulatorStateFactory<?> stateFactory,
Constructor<? extends Accumulator> accumulatorConstructor,
Constructor<? extends GroupedAccumulator> groupedAccumulatorConstructor,
List<Integer> inputChannels,
Optional<Integer> maskChannel)
{
this.stateSerializer = requireNonNull(stateSerializer, "stateSerializer is null");
this.stateFactory = requireNonNull(stateFactory, "stateFactory is null");
this.accumulatorConstructor = requireNonNull(accumulatorConstructor, "accumulatorConstructor is null");
this.groupedAccumulatorConstructor = requireNonNull(groupedAccumulatorConstructor, "groupedAccumulatorConstructor is null");
this.maskChannel = requireNonNull(maskChannel, "maskChannel is null");
this.inputChannels = ImmutableList.copyOf(requireNonNull(inputChannels, "inputChannels is null"));
}
@Override
public List<Integer> getInputChannels()
{
return inputChannels;
}
@Override
public Accumulator createAccumulator()
{
try {
return accumulatorConstructor.newInstance(stateSerializer, stateFactory, inputChannels, maskChannel);
}
catch (InstantiationException | IllegalAccessException | InvocationTargetException e) {
throw Throwables.propagate(e);
}
}
@Override
public Accumulator createIntermediateAccumulator()
{
try {
return accumulatorConstructor.newInstance(stateSerializer, stateFactory, ImmutableList.of(), Optional.empty());
}
catch (InstantiationException | IllegalAccessException | InvocationTargetException e) {
throw Throwables.propagate(e);
}
}
@Override
public GroupedAccumulator createGroupedAccumulator()
{
try {
return groupedAccumulatorConstructor.newInstance(stateSerializer, stateFactory, inputChannels, maskChannel);
}
catch (InstantiationException | IllegalAccessException | InvocationTargetException e) {
throw Throwables.propagate(e);
}
}
@Override
public GroupedAccumulator createGroupedIntermediateAccumulator()
{
try {
return groupedAccumulatorConstructor.newInstance(stateSerializer, stateFactory, ImmutableList.of(), maskChannel);
}
catch (InstantiationException | IllegalAccessException | InvocationTargetException e) {
throw Throwables.propagate(e);
}
}
}