| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 org.apache.druid.query.aggregation; |
| |
| |
| import com.google.common.base.Preconditions; |
| import org.apache.druid.common.config.NullHandling; |
| import org.apache.druid.guice.annotations.ExtensionPoint; |
| import org.apache.druid.segment.BaseNullableColumnValueSelector; |
| import org.apache.druid.segment.ColumnSelectorFactory; |
| import org.apache.druid.segment.ColumnValueSelector; |
| import org.apache.druid.segment.column.ValueType; |
| import org.apache.druid.segment.vector.VectorColumnSelectorFactory; |
| import org.apache.druid.segment.vector.VectorValueSelector; |
| |
| /** |
| * Abstract superclass for null-aware numeric aggregators. |
| * |
| * Includes functionality to wrap {@link Aggregator}, {@link BufferAggregator}, {@link VectorAggregator}, and |
| * {@link AggregateCombiner} to support nullable aggregations. The result of this aggregator will be null if all the |
| * values to be aggregated are null values, or if no values are aggregated at all. If any of the values are non-null, |
| * the result will be the aggregated value of the non-null values. |
| * |
| * This superclass should only be extended by aggregators that read primitive numbers. It implements logic that is |
| * not valid for non-numeric selector methods such as {@link ColumnValueSelector#getObject()}. |
| * |
| * @see BaseNullableColumnValueSelector#isNull() for why this only works in the numeric case |
| */ |
| @ExtensionPoint |
| public abstract class NullableNumericAggregatorFactory<T extends BaseNullableColumnValueSelector> |
| extends AggregatorFactory |
| { |
| @Override |
| public final Aggregator factorize(ColumnSelectorFactory columnSelectorFactory) |
| { |
| T selector = selector(columnSelectorFactory); |
| Aggregator aggregator = factorize(columnSelectorFactory, selector); |
| return NullHandling.replaceWithDefault() ? aggregator : new NullableNumericAggregator(aggregator, selector); |
| } |
| |
| @Override |
| public final BufferAggregator factorizeBuffered(ColumnSelectorFactory columnSelectorFactory) |
| { |
| T selector = selector(columnSelectorFactory); |
| BufferAggregator aggregator = factorizeBuffered(columnSelectorFactory, selector); |
| return NullHandling.replaceWithDefault() ? aggregator : new NullableNumericBufferAggregator(aggregator, selector); |
| } |
| |
| @Override |
| public final VectorAggregator factorizeVector(VectorColumnSelectorFactory columnSelectorFactory) |
| { |
| Preconditions.checkState(canVectorize(columnSelectorFactory), "Cannot vectorize"); |
| VectorValueSelector selector = vectorSelector(columnSelectorFactory); |
| VectorAggregator aggregator = factorizeVector(columnSelectorFactory, selector); |
| return NullHandling.replaceWithDefault() ? aggregator : new NullableNumericVectorAggregator(aggregator, selector); |
| } |
| |
| @Override |
| public final AggregateCombiner makeNullableAggregateCombiner() |
| { |
| AggregateCombiner combiner = makeAggregateCombiner(); |
| return NullHandling.replaceWithDefault() ? combiner : new NullableNumericAggregateCombiner(combiner); |
| } |
| |
| @Override |
| public final int getMaxIntermediateSizeWithNulls() |
| { |
| return getMaxIntermediateSize() + (NullHandling.replaceWithDefault() ? 0 : Byte.BYTES); |
| } |
| |
| // ---- ABSTRACT METHODS BELOW ------ |
| |
| /** |
| * Creates a {@link ColumnValueSelector} for the aggregated column. |
| * |
| * @see ColumnValueSelector |
| */ |
| protected abstract T selector(ColumnSelectorFactory columnSelectorFactory); |
| |
| /** |
| * Creates a {@link VectorValueSelector} for the aggregated column. |
| * |
| * @see VectorValueSelector |
| */ |
| protected VectorValueSelector vectorSelector(VectorColumnSelectorFactory columnSelectorFactory) |
| { |
| throw new UnsupportedOperationException("Cannot vectorize"); |
| } |
| |
| /** |
| * Creates an {@link Aggregator} to aggregate values from several rows, by using the provided selector. |
| * |
| * @param columnSelectorFactory metricFactory |
| * @param selector {@link ColumnValueSelector} for the column to aggregate. |
| * |
| * @see Aggregator |
| */ |
| protected abstract Aggregator factorize(ColumnSelectorFactory columnSelectorFactory, T selector); |
| |
| /** |
| * Creates an {@link BufferAggregator} to aggregate values from several rows into a ByteBuffer. |
| * |
| * @param columnSelectorFactory columnSelectorFactory in case any other columns are needed. |
| * @param selector {@link ColumnValueSelector} for the column to aggregate. |
| * |
| * @see BufferAggregator |
| */ |
| protected abstract BufferAggregator factorizeBuffered( |
| ColumnSelectorFactory columnSelectorFactory, |
| T selector |
| ); |
| |
| /** |
| * Creates a {@link VectorAggregator} to aggregate values from several rows into a ByteBuffer. |
| * |
| * @param columnSelectorFactory columnSelectorFactory in case any other columns are needed. |
| * @param selector {@link VectorValueSelector} for the column to aggregate. |
| * |
| * @see BufferAggregator |
| */ |
| protected VectorAggregator factorizeVector( |
| VectorColumnSelectorFactory columnSelectorFactory, |
| VectorValueSelector selector |
| ) |
| { |
| if (!canVectorize(columnSelectorFactory)) { |
| throw new UnsupportedOperationException("Cannot vectorize"); |
| } else { |
| throw new UnsupportedOperationException("canVectorize returned true but 'factorizeVector' is not implemented"); |
| } |
| } |
| |
| @Override |
| public ValueType getFinalizedType() |
| { |
| return getType(); |
| } |
| } |