| /* |
| * 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.impl.rel; |
| |
| import java.util.List; |
| import javax.annotation.Nullable; |
| import org.apache.beam.sdk.extensions.sql.impl.utils.CalciteUtils; |
| import org.apache.beam.sdk.schemas.Schema; |
| import org.apache.beam.sdk.transforms.DoFn; |
| import org.apache.beam.sdk.transforms.PTransform; |
| import org.apache.beam.sdk.transforms.ParDo; |
| import org.apache.beam.sdk.values.PCollection; |
| import org.apache.beam.sdk.values.PCollectionList; |
| import org.apache.beam.sdk.values.Row; |
| import org.apache.beam.vendor.guava.v20_0.com.google.common.collect.ImmutableList; |
| import org.apache.calcite.plan.RelOptCluster; |
| import org.apache.calcite.plan.RelTraitSet; |
| import org.apache.calcite.rel.RelNode; |
| import org.apache.calcite.rel.RelWriter; |
| import org.apache.calcite.rel.core.Correlate; |
| import org.apache.calcite.rel.core.JoinRelType; |
| import org.apache.calcite.rel.core.Uncollect; |
| import org.apache.calcite.rel.type.RelDataType; |
| import org.apache.calcite.sql.validate.SqlValidatorUtil; |
| |
| /** |
| * {@link BeamRelNode} to implement UNNEST, supporting specifically only {@link Correlate} with |
| * {@link Uncollect}. |
| */ |
| public class BeamUnnestRel extends Uncollect implements BeamRelNode { |
| |
| private final RelDataType unnestType; |
| private final int unnestIndex; |
| |
| public BeamUnnestRel( |
| RelOptCluster cluster, |
| RelTraitSet traitSet, |
| RelNode input, |
| RelDataType unnestType, |
| int unnestIndex) { |
| super(cluster, traitSet, input); |
| this.unnestType = unnestType; |
| this.unnestIndex = unnestIndex; |
| } |
| |
| @Override |
| public Uncollect copy(RelTraitSet traitSet, RelNode input) { |
| return new BeamUnnestRel(getCluster(), traitSet, input, unnestType, unnestIndex); |
| } |
| |
| @Override |
| protected RelDataType deriveRowType() { |
| return SqlValidatorUtil.deriveJoinRowType( |
| input.getRowType(), |
| unnestType, |
| JoinRelType.INNER, |
| getCluster().getTypeFactory(), |
| null, |
| ImmutableList.of()); |
| } |
| |
| @Override |
| public RelWriter explainTerms(RelWriter pw) { |
| return super.explainTerms(pw).item("unnestIndex", Integer.toString(unnestIndex)); |
| } |
| |
| @Override |
| public PTransform<PCollectionList<Row>, PCollection<Row>> buildPTransform() { |
| return new Transform(); |
| } |
| |
| private class Transform extends PTransform<PCollectionList<Row>, PCollection<Row>> { |
| @Override |
| public PCollection<Row> expand(PCollectionList<Row> pinput) { |
| // The set of rows where we run the correlated unnest for each row |
| PCollection<Row> outer = pinput.get(0); |
| |
| Schema joinedSchema = CalciteUtils.toSchema(rowType); |
| |
| return outer |
| .apply(ParDo.of(new UnnestFn(joinedSchema, unnestIndex))) |
| .setRowSchema(joinedSchema); |
| } |
| } |
| |
| private static class UnnestFn extends DoFn<Row, Row> { |
| |
| private final Schema outputSchema; |
| private final int unnestIndex; |
| |
| private UnnestFn(Schema outputSchema, int unnestIndex) { |
| this.outputSchema = outputSchema; |
| this.unnestIndex = unnestIndex; |
| } |
| |
| @ProcessElement |
| public void process(@Element Row row, OutputReceiver<Row> out) { |
| |
| @Nullable List<Object> rawValues = row.getArray(unnestIndex); |
| |
| if (rawValues == null) { |
| return; |
| } |
| |
| for (Object uncollectedValue : rawValues) { |
| out.output( |
| Row.withSchema(outputSchema) |
| .addValues(row.getValues()) |
| .addValue(uncollectedValue) |
| .build()); |
| } |
| } |
| } |
| } |