/*
* 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.operator.GroupByIdBlock;
import com.facebook.presto.operator.aggregation.state.AccumulatorState;
import com.facebook.presto.operator.aggregation.state.AccumulatorStateFactory;
import com.facebook.presto.operator.aggregation.state.AccumulatorStateSerializer;
import com.facebook.presto.operator.aggregation.state.GroupedAccumulatorState;
import com.facebook.presto.operator.aggregation.state.StateCompiler;
import com.facebook.presto.spi.block.Block;
import com.facebook.presto.spi.block.BlockBuilder;
import com.facebook.presto.spi.type.Type;
import com.google.common.base.Optional;
import io.airlift.event.client.TypeParameterUtils;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkState;
public abstract class AbstractApproximateAggregationFunction<T extends AccumulatorState>
extends SimpleAggregationFunction
{
private final AccumulatorStateFactory<T> stateFactory;
private final AccumulatorStateSerializer<T> stateSerializer;
protected AbstractApproximateAggregationFunction(Type finalType, Type intermediateType, Type parameterType)
{
super(finalType, intermediateType, parameterType);
java.lang.reflect.Type[] types = TypeParameterUtils.getTypeParameters(AbstractApproximateAggregationFunction.class, getClass());
checkState(types.length == 1 && types[0] instanceof Class);
stateFactory = new StateCompiler().generateStateFactory((Class<T>) types[0]);
stateSerializer = new StateCompiler().generateStateSerializer((Class<T>) types[0]);
}
protected abstract void processInput(T state, Block block, int index, long sampleWeight);
protected void processIntermediate(T state, T scratchState, Block block, int index)
{
stateSerializer.deserialize(block, index, scratchState);
combineState(state, scratchState);
}
/**
* Combines two pieces of state. The result should be stored in state.
*/
protected abstract void combineState(T state, T otherState);
protected abstract void evaluateFinal(T state, double confidence, BlockBuilder out);
private T createSingleState()
{
return stateFactory.createSingleState();
}
private T createGroupedState()
{
return stateFactory.createGroupedState();
}
protected AccumulatorStateSerializer<T> getStateSerializer()
{
return stateSerializer;
}
@Override
protected final GroupedAccumulator createGroupedAccumulator(Optional<Integer> maskChannel, Optional<Integer> sampleWeightChannel, double confidence, int valueChannel)
{
return new GenericGroupedAccumulator(valueChannel, maskChannel, sampleWeightChannel, confidence);
}
public final class GenericGroupedAccumulator
extends SimpleGroupedAccumulator
{
private final T state;
// Reference to state cast as a GroupedAccumulatorState
private final GroupedAccumulatorState groupedState;
private final double confidence;
public GenericGroupedAccumulator(int valueChannel, Optional<Integer> maskChannel, Optional<Integer> sampleWeightChannel, double confidence)
{
super(valueChannel, AbstractApproximateAggregationFunction.this.getFinalType(), AbstractApproximateAggregationFunction.this.getIntermediateType(), maskChannel, sampleWeightChannel);
this.state = AbstractApproximateAggregationFunction.this.createGroupedState();
checkArgument(state instanceof GroupedAccumulatorState, "state is not a GroupedAccumulatorState");
groupedState = (GroupedAccumulatorState) state;
this.confidence = confidence;
}
@Override
public long getEstimatedSize()
{
return state.getEstimatedSize();
}
@Override
protected void processInput(GroupByIdBlock groupIdsBlock, Block values, Optional<Block> maskBlock, Optional<Block> sampleWeightBlock)
{
groupedState.ensureCapacity(groupIdsBlock.getGroupCount());
Block masks = null;
if (maskBlock.isPresent()) {
masks = maskBlock.get();
}
Block sampleWeights = null;
if (sampleWeightBlock.isPresent()) {
sampleWeights = sampleWeightBlock.get();
}
for (int position = 0; position < groupIdsBlock.getPositionCount(); position++) {
long sampleWeight = ApproximateUtils.computeSampleWeight(masks, sampleWeights, position);
if (!values.isNull(position) && sampleWeight > 0) {
groupedState.setGroupId(groupIdsBlock.getGroupId(position));
AbstractApproximateAggregationFunction.this.processInput(state, values, position, sampleWeight);
}
}
}
@Override
protected void processIntermediate(GroupByIdBlock groupIdsBlock, Block intermediates)
{
groupedState.ensureCapacity(groupIdsBlock.getGroupCount());
T scratchState = AbstractApproximateAggregationFunction.this.createSingleState();
for (int position = 0; position < groupIdsBlock.getPositionCount(); position++) {
if (!intermediates.isNull(position)) {
groupedState.setGroupId(groupIdsBlock.getGroupId(position));
AbstractApproximateAggregationFunction.this.processIntermediate(state, scratchState, intermediates, position);
}
}
}
@Override
public void evaluateIntermediate(int groupId, BlockBuilder output)
{
groupedState.setGroupId(groupId);
getStateSerializer().serialize(state, output);
}
@Override
public void evaluateFinal(int groupId, BlockBuilder output)
{
groupedState.setGroupId(groupId);
AbstractApproximateAggregationFunction.this.evaluateFinal(state, confidence, output);
}
}
@Override
protected final Accumulator createAccumulator(Optional<Integer> maskChannel, Optional<Integer> sampleWeightChannel, double confidence, int valueChannel)
{
return new GenericAccumulator(valueChannel, maskChannel, sampleWeightChannel, confidence);
}
public final class GenericAccumulator
extends SimpleAccumulator
{
private final T state;
private final double confidence;
public GenericAccumulator(int valueChannel, Optional<Integer> maskChannel, Optional<Integer> sampleWeightChannel, double confidence)
{
super(valueChannel, AbstractApproximateAggregationFunction.this.getFinalType(), AbstractApproximateAggregationFunction.this.getIntermediateType(), maskChannel, sampleWeightChannel);
this.state = AbstractApproximateAggregationFunction.this.createSingleState();
this.confidence = confidence;
}
@Override
protected void processInput(Block values, Optional<Block> maskBlock, Optional<Block> sampleWeightBlock)
{
Block masks = null;
if (maskBlock.isPresent()) {
masks = maskBlock.get();
}
Block sampleWeights = null;
if (sampleWeightBlock.isPresent()) {
sampleWeights = sampleWeightBlock.get();
}
for (int position = 0; position < values.getPositionCount(); position++) {
long sampleWeight = ApproximateUtils.computeSampleWeight(masks, sampleWeights, position);
if (!values.isNull(position) && sampleWeight > 0) {
AbstractApproximateAggregationFunction.this.processInput(state, values, position, sampleWeight);
}
}
}
@Override
public long getEstimatedSize()
{
return state.getEstimatedSize();
}
@Override
protected void processIntermediate(Block block)
{
T scratchState = AbstractApproximateAggregationFunction.this.createSingleState();
for (int position = 0; position < block.getPositionCount(); position++) {
if (!block.isNull(position)) {
AbstractApproximateAggregationFunction.this.processIntermediate(state, scratchState, block, position);
}
}
}
@Override
protected void evaluateIntermediate(BlockBuilder out)
{
getStateSerializer().serialize(state, out);
}
@Override
public void evaluateFinal(BlockBuilder out)
{
AbstractApproximateAggregationFunction.this.evaluateFinal(state, confidence, out);
}
}
}