| /* |
| * 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.drill.exec.expr.fn.output; |
| |
| import java.util.List; |
| import java.util.Set; |
| |
| import org.apache.drill.common.expression.LogicalExpression; |
| import org.apache.drill.common.types.TypeProtos; |
| import org.apache.drill.exec.expr.fn.FunctionAttributes; |
| import org.apache.drill.exec.expr.fn.FunctionUtils; |
| import org.apache.drill.exec.expr.fn.ValueReference; |
| import com.google.common.collect.Sets; |
| |
| /** |
| * Return type calculation implementation for functions with return type set as |
| * {@link org.apache.drill.exec.expr.annotations.FunctionTemplate.ReturnType#DEFAULT}. |
| */ |
| public class DefaultReturnTypeInference implements ReturnTypeInference { |
| |
| public static final DefaultReturnTypeInference INSTANCE = new DefaultReturnTypeInference(); |
| |
| /** |
| * Calculates return type and its nullability. Precision and scale is not included. |
| * |
| * @param logicalExpressions logical expressions |
| * @param attributes function attributes |
| * @return return type |
| */ |
| @Override |
| public TypeProtos.MajorType getType(List<LogicalExpression> logicalExpressions, FunctionAttributes attributes) { |
| if (attributes.getReturnValue().getType().getMinorType() == TypeProtos.MinorType.UNION) { |
| Set<TypeProtos.MinorType> subTypes = Sets.newHashSet(); |
| for (ValueReference ref : attributes.getParameters()) { |
| subTypes.add(ref.getType().getMinorType()); |
| } |
| |
| TypeProtos.MajorType.Builder builder = TypeProtos.MajorType.newBuilder() |
| .setMinorType(TypeProtos.MinorType.UNION) |
| .setMode(TypeProtos.DataMode.OPTIONAL); |
| |
| for (TypeProtos.MinorType subType : subTypes) { |
| // LATE is not a valid concrete type; used only as a method |
| // annotation. |
| if (subType != TypeProtos.MinorType.LATE) { |
| builder.addSubType(subType); |
| } |
| } |
| return builder.build(); |
| } |
| return attributes.getReturnValue().getType().toBuilder() |
| .setMode(FunctionUtils.getReturnTypeDataMode(logicalExpressions, attributes)) |
| .build(); |
| } |
| } |