| /* |
| * 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.wayang.basic.operators; |
| |
| import java.util.Optional; |
| import org.apache.commons.lang3.Validate; |
| import org.apache.wayang.core.api.Configuration; |
| import org.apache.wayang.core.function.PredicateDescriptor; |
| import org.apache.wayang.core.optimizer.OptimizationContext; |
| import org.apache.wayang.core.optimizer.ProbabilisticDoubleInterval; |
| import org.apache.wayang.core.optimizer.cardinality.CardinalityEstimate; |
| import org.apache.wayang.core.plan.wayangplan.UnaryToUnaryOperator; |
| import org.apache.wayang.core.types.DataSetType; |
| |
| |
| /** |
| * This operator returns a new dataset after filtering by applying predicateDescriptor. |
| */ |
| public class FilterOperator<Type> extends UnaryToUnaryOperator<Type, Type> { |
| |
| /** |
| * Function that this operator applies to the input elements. |
| */ |
| protected final PredicateDescriptor<Type> predicateDescriptor; |
| |
| /** |
| * Creates a new instance. |
| */ |
| public FilterOperator(PredicateDescriptor.SerializablePredicate<Type> predicateDescriptor, Class<Type> typeClass) { |
| this(new PredicateDescriptor<>(predicateDescriptor, typeClass)); |
| } |
| |
| /** |
| * Creates a new instance. |
| */ |
| public FilterOperator(PredicateDescriptor<Type> predicateDescriptor) { |
| super(DataSetType.createDefault(predicateDescriptor.getInputType()), |
| DataSetType.createDefault(predicateDescriptor.getInputType()), |
| true); |
| this.predicateDescriptor = predicateDescriptor; |
| } |
| |
| /** |
| * Creates a new instance. |
| * |
| * @param type type of the dataunit elements |
| */ |
| public FilterOperator(DataSetType<Type> type, PredicateDescriptor.SerializablePredicate<Type> predicateDescriptor) { |
| this(new PredicateDescriptor<>(predicateDescriptor, type.getDataUnitType().getTypeClass()), type); |
| } |
| |
| /** |
| * Creates a new instance. |
| * |
| * @param type type of the dataunit elements |
| */ |
| public FilterOperator(PredicateDescriptor<Type> predicateDescriptor, DataSetType<Type> type) { |
| super(type, type, true); |
| this.predicateDescriptor = predicateDescriptor; |
| } |
| |
| /** |
| * Copies an instance (exclusive of broadcasts). |
| * |
| * @param that that should be copied |
| */ |
| public FilterOperator(FilterOperator<Type> that) { |
| super(that); |
| this.predicateDescriptor = that.getPredicateDescriptor(); |
| } |
| |
| public PredicateDescriptor<Type> getPredicateDescriptor() { |
| return this.predicateDescriptor; |
| } |
| |
| @Override |
| public Optional<org.apache.wayang.core.optimizer.cardinality.CardinalityEstimator> createCardinalityEstimator( |
| final int outputIndex, |
| final Configuration configuration) { |
| Validate.inclusiveBetween(0, this.getNumOutputs() - 1, outputIndex); |
| return Optional.of(new FilterOperator.CardinalityEstimator(this.predicateDescriptor, configuration)); |
| } |
| |
| public DataSetType<Type> getType() { |
| return this.getInputType(); |
| } |
| |
| /** |
| * Custom {@link org.apache.wayang.core.optimizer.cardinality.CardinalityEstimator} for {@link FilterOperator}s. |
| */ |
| private class CardinalityEstimator implements org.apache.wayang.core.optimizer.cardinality.CardinalityEstimator { |
| |
| /** |
| * The expected selectivity to be applied in this instance. |
| */ |
| private final ProbabilisticDoubleInterval selectivity; |
| |
| public CardinalityEstimator(PredicateDescriptor<?> predicateDescriptor, Configuration configuration) { |
| this.selectivity = configuration.getUdfSelectivityProvider().provideFor(predicateDescriptor); |
| } |
| |
| @Override |
| public CardinalityEstimate estimate(OptimizationContext optimizationContext, CardinalityEstimate... inputEstimates) { |
| Validate.isTrue(inputEstimates.length == FilterOperator.this.getNumInputs()); |
| final CardinalityEstimate inputEstimate = inputEstimates[0]; |
| |
| return new CardinalityEstimate( |
| (long) (inputEstimate.getLowerEstimate() * this.selectivity.getLowerEstimate()), |
| (long) (inputEstimate.getUpperEstimate() * this.selectivity.getUpperEstimate()), |
| inputEstimate.getCorrectnessProbability() * this.selectivity.getCorrectnessProbability() |
| ); |
| } |
| } |
| } |