DecimalSumAggregation.java
/*
* 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.bytecode.DynamicClassLoader;
import com.facebook.presto.common.block.Block;
import com.facebook.presto.common.block.BlockBuilder;
import com.facebook.presto.common.type.DecimalType;
import com.facebook.presto.common.type.Type;
import com.facebook.presto.common.type.UnscaledDecimal128Arithmetic;
import com.facebook.presto.metadata.BoundVariables;
import com.facebook.presto.metadata.FunctionAndTypeManager;
import com.facebook.presto.metadata.SqlAggregationFunction;
import com.facebook.presto.operator.aggregation.state.LongDecimalWithOverflowState;
import com.facebook.presto.operator.aggregation.state.LongDecimalWithOverflowStateFactory;
import com.facebook.presto.operator.aggregation.state.LongDecimalWithOverflowStateSerializer;
import com.facebook.presto.spi.function.AccumulatorState;
import com.facebook.presto.spi.function.AccumulatorStateSerializer;
import com.facebook.presto.spi.function.FunctionKind;
import com.facebook.presto.spi.function.aggregation.Accumulator;
import com.facebook.presto.spi.function.aggregation.AggregationMetadata;
import com.facebook.presto.spi.function.aggregation.AggregationMetadata.AccumulatorStateDescriptor;
import com.facebook.presto.spi.function.aggregation.GroupedAccumulator;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import io.airlift.slice.Slice;
import java.lang.invoke.MethodHandle;
import java.util.List;
import static com.facebook.presto.common.type.Decimals.MAX_PRECISION;
import static com.facebook.presto.common.type.Decimals.MAX_SHORT_PRECISION;
import static com.facebook.presto.common.type.TypeSignature.parseTypeSignature;
import static com.facebook.presto.common.type.UnscaledDecimal128Arithmetic.throwIfOverflows;
import static com.facebook.presto.common.type.UnscaledDecimal128Arithmetic.throwOverflowException;
import static com.facebook.presto.common.type.UnscaledDecimal128Arithmetic.unscaledDecimal;
import static com.facebook.presto.metadata.SignatureBinder.applyBoundVariables;
import static com.facebook.presto.operator.aggregation.AggregationUtils.generateAggregationName;
import static com.facebook.presto.spi.function.aggregation.AggregationMetadata.ParameterMetadata;
import static com.facebook.presto.spi.function.aggregation.AggregationMetadata.ParameterMetadata.ParameterType.BLOCK_INDEX;
import static com.facebook.presto.spi.function.aggregation.AggregationMetadata.ParameterMetadata.ParameterType.BLOCK_INPUT_CHANNEL;
import static com.facebook.presto.spi.function.aggregation.AggregationMetadata.ParameterMetadata.ParameterType.STATE;
import static com.facebook.presto.util.Reflection.methodHandle;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.collect.ImmutableList.toImmutableList;
import static com.google.common.collect.Iterables.getOnlyElement;
public class DecimalSumAggregation
extends SqlAggregationFunction
{
// Constant references for short/long decimal types for use in operations that only manipulate unscaled values
private static final DecimalType LONG_DECIMAL_TYPE = DecimalType.createDecimalType(MAX_PRECISION, 0);
private static final DecimalType SHORT_DECIMAL_TYPE = DecimalType.createDecimalType(MAX_SHORT_PRECISION, 0);
public static final DecimalSumAggregation DECIMAL_SUM_AGGREGATION = new DecimalSumAggregation();
private static final String NAME = "sum";
private static final MethodHandle SHORT_DECIMAL_INPUT_FUNCTION = methodHandle(DecimalSumAggregation.class, "inputShortDecimal", LongDecimalWithOverflowState.class, Block.class, int.class);
private static final MethodHandle LONG_DECIMAL_INPUT_FUNCTION = methodHandle(DecimalSumAggregation.class, "inputLongDecimal", LongDecimalWithOverflowState.class, Block.class, int.class);
private static final MethodHandle LONG_DECIMAL_OUTPUT_FUNCTION = methodHandle(DecimalSumAggregation.class, "outputLongDecimal", LongDecimalWithOverflowState.class, BlockBuilder.class);
private static final MethodHandle COMBINE_FUNCTION = methodHandle(DecimalSumAggregation.class, "combine", LongDecimalWithOverflowState.class, LongDecimalWithOverflowState.class);
public DecimalSumAggregation()
{
super(NAME,
ImmutableList.of(),
ImmutableList.of(),
parseTypeSignature("decimal(38,s)", ImmutableSet.of("s")),
ImmutableList.of(parseTypeSignature("decimal(p,s)", ImmutableSet.of("p", "s"))),
FunctionKind.AGGREGATE);
}
@Override
public String getDescription()
{
return "Calculates the sum over the input values";
}
@Override
public BuiltInAggregationFunctionImplementation specialize(BoundVariables boundVariables, int arity, FunctionAndTypeManager functionAndTypeManager)
{
Type inputType = getOnlyElement(applyBoundVariables(functionAndTypeManager, getSignature().getArgumentTypes(), boundVariables));
Type outputType = applyBoundVariables(functionAndTypeManager, getSignature().getReturnType(), boundVariables);
return generateAggregation(inputType, outputType);
}
private static BuiltInAggregationFunctionImplementation generateAggregation(Type inputType, Type outputType)
{
checkArgument(inputType instanceof DecimalType, "type must be Decimal");
DynamicClassLoader classLoader = new DynamicClassLoader(DecimalSumAggregation.class.getClassLoader());
List<Type> inputTypes = ImmutableList.of(inputType);
MethodHandle inputFunction;
Class<? extends AccumulatorState> stateInterface = LongDecimalWithOverflowState.class;
AccumulatorStateSerializer<?> stateSerializer = new LongDecimalWithOverflowStateSerializer();
if (((DecimalType) inputType).isShort()) {
inputFunction = SHORT_DECIMAL_INPUT_FUNCTION;
}
else {
inputFunction = LONG_DECIMAL_INPUT_FUNCTION;
}
AggregationMetadata metadata = new AggregationMetadata(
generateAggregationName(NAME, outputType.getTypeSignature(), inputTypes.stream().map(Type::getTypeSignature).collect(toImmutableList())),
createInputParameterMetadata(inputType),
inputFunction,
COMBINE_FUNCTION,
LONG_DECIMAL_OUTPUT_FUNCTION,
ImmutableList.of(new AccumulatorStateDescriptor(
stateInterface,
stateSerializer,
new LongDecimalWithOverflowStateFactory())),
outputType);
Type intermediateType = stateSerializer.getSerializedType();
Class<? extends Accumulator> accumulatorClass = AccumulatorCompiler.generateAccumulatorClass(
Accumulator.class,
metadata,
classLoader);
Class<? extends GroupedAccumulator> groupedAccumulatorClass = AccumulatorCompiler.generateAccumulatorClass(
GroupedAccumulator.class,
metadata,
classLoader);
return new BuiltInAggregationFunctionImplementation(NAME, inputTypes, ImmutableList.of(intermediateType), outputType,
true, false, metadata, accumulatorClass, groupedAccumulatorClass);
}
private static List<ParameterMetadata> createInputParameterMetadata(Type type)
{
return ImmutableList.of(new ParameterMetadata(STATE), new ParameterMetadata(BLOCK_INPUT_CHANNEL, type), new ParameterMetadata(BLOCK_INDEX));
}
public static void inputShortDecimal(LongDecimalWithOverflowState state, Block block, int position)
{
Slice currentSum = state.getLongDecimal();
if (currentSum == null) {
currentSum = unscaledDecimal();
state.setLongDecimal(currentSum);
}
state.addOverflow(UnscaledDecimal128Arithmetic.addWithOverflow(currentSum, unscaledDecimal(SHORT_DECIMAL_TYPE.getLong(block, position)), currentSum));
}
public static void inputLongDecimal(LongDecimalWithOverflowState state, Block block, int position)
{
Slice currentSum = state.getLongDecimal();
if (currentSum == null) {
currentSum = unscaledDecimal();
state.setLongDecimal(currentSum);
}
state.addOverflow(UnscaledDecimal128Arithmetic.addWithOverflow(currentSum, LONG_DECIMAL_TYPE.getSlice(block, position), currentSum));
}
public static void combine(LongDecimalWithOverflowState state, LongDecimalWithOverflowState otherState)
{
long overflowToAdd = otherState.getOverflow();
Slice currentState = state.getLongDecimal();
Slice otherDecimal = otherState.getLongDecimal();
if (currentState == null) {
state.setLongDecimal(otherDecimal);
}
else {
overflowToAdd += UnscaledDecimal128Arithmetic.addWithOverflow(currentState, otherDecimal, currentState);
}
state.addOverflow(overflowToAdd);
}
public static void outputLongDecimal(LongDecimalWithOverflowState state, BlockBuilder out)
{
Slice decimal = state.getLongDecimal();
if (decimal == null) {
out.appendNull();
}
else {
if (state.getOverflow() != 0) {
throwOverflowException();
}
throwIfOverflows(decimal);
LONG_DECIMAL_TYPE.writeSlice(out, decimal);
}
}
}