/*
* 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.metadata.BoundVariables;
import com.facebook.presto.metadata.FunctionRegistry;
import com.facebook.presto.metadata.SqlAggregationFunction;
import com.facebook.presto.operator.aggregation.AggregationMetadata.ParameterMetadata;
import com.facebook.presto.operator.aggregation.state.ArrayAggregationState;
import com.facebook.presto.operator.aggregation.state.ArrayAggregationStateFactory;
import com.facebook.presto.operator.aggregation.state.ArrayAggregationStateSerializer;
import com.facebook.presto.spi.block.Block;
import com.facebook.presto.spi.block.BlockBuilder;
import com.facebook.presto.spi.block.BlockBuilderStatus;
import com.facebook.presto.spi.function.AccumulatorState;
import com.facebook.presto.spi.function.AccumulatorStateFactory;
import com.facebook.presto.spi.function.AccumulatorStateSerializer;
import com.facebook.presto.spi.type.Type;
import com.facebook.presto.spi.type.TypeManager;
import com.facebook.presto.type.ArrayType;
import com.google.common.collect.ImmutableList;
import java.lang.invoke.MethodHandle;
import java.util.List;
import static com.facebook.presto.metadata.Signature.typeVariable;
import static com.facebook.presto.operator.aggregation.AggregationMetadata.ParameterMetadata.ParameterType.BLOCK_INDEX;
import static com.facebook.presto.operator.aggregation.AggregationMetadata.ParameterMetadata.ParameterType.BLOCK_INPUT_CHANNEL;
import static com.facebook.presto.operator.aggregation.AggregationMetadata.ParameterMetadata.ParameterType.NULLABLE_BLOCK_INPUT_CHANNEL;
import static com.facebook.presto.operator.aggregation.AggregationMetadata.ParameterMetadata.ParameterType.STATE;
import static com.facebook.presto.operator.aggregation.AggregationUtils.generateAggregationName;
import static com.facebook.presto.spi.type.TypeSignature.parseTypeSignature;
import static com.facebook.presto.util.Reflection.methodHandle;
import static com.google.common.collect.ImmutableList.toImmutableList;
public class ArrayAggregationFunction
extends SqlAggregationFunction
{
private static final String NAME = "array_agg";
private static final MethodHandle INPUT_FUNCTION = methodHandle(ArrayAggregationFunction.class, "input", Type.class, ArrayAggregationState.class, Block.class, int.class);
private static final MethodHandle COMBINE_FUNCTION = methodHandle(ArrayAggregationFunction.class, "combine", Type.class, ArrayAggregationState.class, ArrayAggregationState.class);
private static final MethodHandle OUTPUT_FUNCTION = methodHandle(ArrayAggregationFunction.class, "output", Type.class, ArrayAggregationState.class, BlockBuilder.class);
private final boolean legacyArrayAgg;
public ArrayAggregationFunction(boolean legacyArrayAgg)
{
super(NAME,
ImmutableList.of(typeVariable("T")),
ImmutableList.of(),
parseTypeSignature("array(T)"),
ImmutableList.of(parseTypeSignature("T")));
this.legacyArrayAgg = legacyArrayAgg;
}
@Override
public String getDescription()
{
return "return an array of values";
}
@Override
public InternalAggregationFunction specialize(BoundVariables boundVariables, int arity, TypeManager typeManager, FunctionRegistry functionRegistry)
{
Type type = boundVariables.getTypeVariable("T");
return generateAggregation(type, legacyArrayAgg);
}
private static InternalAggregationFunction generateAggregation(Type type, boolean legacyArrayAgg)
{
DynamicClassLoader classLoader = new DynamicClassLoader(ArrayAggregationFunction.class.getClassLoader());
AccumulatorStateSerializer<?> stateSerializer = new ArrayAggregationStateSerializer(type);
AccumulatorStateFactory<?> stateFactory = new ArrayAggregationStateFactory();
List<Type> inputTypes = ImmutableList.of(type);
Type outputType = new ArrayType(type);
Type intermediateType = stateSerializer.getSerializedType();
List<ParameterMetadata> inputParameterMetadata = createInputParameterMetadata(type, legacyArrayAgg);
MethodHandle inputFunction = INPUT_FUNCTION.bindTo(type);
MethodHandle combineFunction = COMBINE_FUNCTION.bindTo(type);
MethodHandle outputFunction = OUTPUT_FUNCTION.bindTo(outputType);
Class<? extends AccumulatorState> stateInterface = ArrayAggregationState.class;
AggregationMetadata metadata = new AggregationMetadata(
generateAggregationName(NAME, type.getTypeSignature(), inputTypes.stream().map(Type::getTypeSignature).collect(toImmutableList())),
inputParameterMetadata,
inputFunction,
combineFunction,
outputFunction,
stateInterface,
stateSerializer,
stateFactory,
outputType);
GenericAccumulatorFactoryBinder factory = AccumulatorCompiler.generateAccumulatorFactoryBinder(metadata, classLoader);
return new InternalAggregationFunction(NAME, inputTypes, intermediateType, outputType, true, factory);
}
private static List<ParameterMetadata> createInputParameterMetadata(Type value, boolean legacyArrayAgg)
{
return ImmutableList.of(new ParameterMetadata(STATE), new ParameterMetadata(legacyArrayAgg ? BLOCK_INPUT_CHANNEL : NULLABLE_BLOCK_INPUT_CHANNEL, value), new ParameterMetadata(BLOCK_INDEX));
}
public static void input(Type type, ArrayAggregationState state, Block value, int position)
{
BlockBuilder blockBuilder = state.getBlockBuilder();
if (blockBuilder == null) {
blockBuilder = type.createBlockBuilder(new BlockBuilderStatus(), 4);
state.setBlockBuilder(blockBuilder);
}
long startSize = blockBuilder.getRetainedSizeInBytes();
type.appendTo(value, position, blockBuilder);
state.addMemoryUsage(blockBuilder.getRetainedSizeInBytes() - startSize);
}
public static void combine(Type type, ArrayAggregationState state, ArrayAggregationState otherState)
{
BlockBuilder stateBlockBuilder = state.getBlockBuilder();
BlockBuilder otherStateBlockBuilder = otherState.getBlockBuilder();
if (otherStateBlockBuilder == null) {
return;
}
if (stateBlockBuilder == null) {
state.setBlockBuilder(otherStateBlockBuilder);
return;
}
int otherPositionCount = otherStateBlockBuilder.getPositionCount();
long startSize = stateBlockBuilder.getRetainedSizeInBytes();
for (int i = 0; i < otherPositionCount; i++) {
type.appendTo(otherStateBlockBuilder, i, stateBlockBuilder);
}
state.addMemoryUsage(stateBlockBuilder.getRetainedSizeInBytes() - startSize);
}
public static void output(Type outputType, ArrayAggregationState state, BlockBuilder out)
{
BlockBuilder stateBlockBuilder = state.getBlockBuilder();
if (stateBlockBuilder == null || stateBlockBuilder.getPositionCount() == 0) {
out.appendNull();
}
else {
outputType.writeObject(out, stateBlockBuilder.build());
}
}
}