| /* |
| * 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.beam.sdk.extensions.sql.zetasql.translation; |
| |
| import static com.google.zetasql.resolvedast.ResolvedSetOperationScanEnums.SetOperationType.EXCEPT_ALL; |
| import static com.google.zetasql.resolvedast.ResolvedSetOperationScanEnums.SetOperationType.EXCEPT_DISTINCT; |
| import static com.google.zetasql.resolvedast.ResolvedSetOperationScanEnums.SetOperationType.INTERSECT_ALL; |
| import static com.google.zetasql.resolvedast.ResolvedSetOperationScanEnums.SetOperationType.INTERSECT_DISTINCT; |
| import static com.google.zetasql.resolvedast.ResolvedSetOperationScanEnums.SetOperationType.UNION_ALL; |
| import static com.google.zetasql.resolvedast.ResolvedSetOperationScanEnums.SetOperationType.UNION_DISTINCT; |
| import static java.util.stream.Collectors.toList; |
| |
| import com.google.zetasql.resolvedast.ResolvedNode; |
| import com.google.zetasql.resolvedast.ResolvedNodes.ResolvedSetOperationItem; |
| import com.google.zetasql.resolvedast.ResolvedNodes.ResolvedSetOperationScan; |
| import com.google.zetasql.resolvedast.ResolvedSetOperationScanEnums.SetOperationType; |
| import java.util.List; |
| import java.util.function.BiFunction; |
| import java.util.function.Function; |
| import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.rel.RelNode; |
| import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.rel.logical.LogicalIntersect; |
| import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.rel.logical.LogicalMinus; |
| import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.rel.logical.LogicalUnion; |
| import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableList; |
| import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableMap; |
| |
| /** Converts set operations. */ |
| class SetOperationScanConverter extends RelConverter<ResolvedSetOperationScan> { |
| private enum Type { |
| DISTINCT, |
| ALL |
| } |
| |
| private static final ImmutableMap<SetOperationType, Function<List<RelNode>, RelNode>> |
| SET_OPERATION_FACTORIES = |
| ImmutableMap.<SetOperationType, Function<List<RelNode>, RelNode>>builder() |
| .put(UNION_ALL, createFactoryFor(LogicalUnion::create, Type.ALL)) |
| .put(UNION_DISTINCT, createFactoryFor(LogicalUnion::create, Type.DISTINCT)) |
| .put(INTERSECT_ALL, createFactoryFor(LogicalIntersect::create, Type.ALL)) |
| .put(INTERSECT_DISTINCT, createFactoryFor(LogicalIntersect::create, Type.DISTINCT)) |
| .put(EXCEPT_ALL, createFactoryFor(LogicalMinus::create, Type.ALL)) |
| .put(EXCEPT_DISTINCT, createFactoryFor(LogicalMinus::create, Type.DISTINCT)) |
| .build(); |
| |
| /** |
| * A little closure to wrap the invocation of the factory method (e.g. LogicalUnion::create) for |
| * the set operation node. |
| */ |
| private static Function<List<RelNode>, RelNode> createFactoryFor( |
| BiFunction<List<RelNode>, Boolean, RelNode> setOperationFactory, Type type) { |
| return (List<RelNode> inputs) -> createRel(setOperationFactory, type == Type.ALL, inputs); |
| } |
| |
| SetOperationScanConverter(ConversionContext context) { |
| super(context); |
| } |
| |
| @Override |
| public List<ResolvedNode> getInputs(ResolvedSetOperationScan zetaNode) { |
| return zetaNode.getInputItemList().stream() |
| .map(ResolvedSetOperationItem::getScan) |
| .collect(toList()); |
| } |
| |
| @Override |
| public RelNode convert(ResolvedSetOperationScan zetaNode, List<RelNode> inputs) { |
| if (!SET_OPERATION_FACTORIES.containsKey(zetaNode.getOpType())) { |
| throw new UnsupportedOperationException( |
| "Operation " + zetaNode.getOpType() + " is unsupported"); |
| } |
| |
| return SET_OPERATION_FACTORIES.get(zetaNode.getOpType()).apply(inputs); |
| } |
| |
| /** Beam set operations rel expects two inputs, so we are constructing a binary tree here. */ |
| private static RelNode createRel( |
| BiFunction<List<RelNode>, Boolean, RelNode> factory, boolean all, List<RelNode> inputs) { |
| return inputs.stream() |
| .skip(2) |
| .reduce( |
| // start with creating a set node for two first inputs |
| invokeFactory(factory, inputs.get(0), inputs.get(1), all), |
| // create another operation node with previous op node and the next input |
| (setOpNode, nextInput) -> invokeFactory(factory, setOpNode, nextInput, all)); |
| } |
| |
| /** |
| * Creates a set operation rel with two inputs. |
| * |
| * <p>Factory is, for example, LogicalUnion::create. |
| */ |
| private static RelNode invokeFactory( |
| BiFunction<List<RelNode>, Boolean, RelNode> factory, |
| RelNode input1, |
| RelNode input2, |
| boolean all) { |
| return factory.apply(ImmutableList.of(input1, input2), all); |
| } |
| } |