ahmedabu98 commented on code in PR #39600: URL: https://github.com/apache/beam/pull/39600#discussion_r3722492755
########## sdks/java/io/iceberg/src/main/java/org/apache/beam/sdk/io/iceberg/cdc/ResolveChanges.java: ########## @@ -0,0 +1,147 @@ +/* + * 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.io.iceberg.cdc; + +import java.util.HashSet; +import java.util.List; +import java.util.Set; +import java.util.stream.Collectors; +import org.apache.beam.sdk.io.iceberg.IcebergScanConfig; +import org.apache.beam.sdk.io.iceberg.IcebergUtils; +import org.apache.beam.sdk.schemas.Schema; +import org.apache.beam.sdk.transforms.DoFn; +import org.apache.beam.sdk.transforms.join.CoGbkResult; +import org.apache.beam.sdk.util.RowFilter; +import org.apache.beam.sdk.values.KV; +import org.apache.beam.sdk.values.Row; +import org.apache.beam.sdk.values.TupleTag; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.Lists; +import org.apache.iceberg.types.Types; +import org.joda.time.Instant; + +/** + * Receives a {@link CoGbkResult} containing inserts and deletes sharing the same snapshot sequence + * number and Primary Key, and uses {@link CdcResolver} to identify logical updates. + */ +class ResolveChanges extends DoFn<KV<CdcRowDescriptor, CoGbkResult>, Row> { + static final TupleTag<Row> DELETES = new TupleTag<>() {}; + static final TupleTag<Row> INSERTS = new TupleTag<>() {}; + private final IcebergScanConfig scanConfig; + private final RowFilter rowFilter; + private final Schema outputSchema; + + ResolveChanges(IcebergScanConfig scanConfig) { + this.scanConfig = scanConfig; + this.rowFilter = + new RowFilter( + CdcOutputUtils.readBeamSchemaWithRowMetadata( + scanConfig.getMetadataColumns(), scanConfig.getSchema())) + .keep( + CdcOutputUtils.readSchemaWithRowMetadata( + scanConfig.getMetadataColumns(), scanConfig.getProjectedSchema()) + .columns().stream() + .map(Types.NestedField::name) + .collect(Collectors.toList())); + this.outputSchema = + CdcOutputUtils.outputSchema( + scanConfig, + IcebergUtils.icebergSchemaToBeamSchema( + scanConfig.getProjectedSchema(), scanConfig.getUpdateCompatibilityVersion())); + } + + @ProcessElement + public void processElement( + @Element KV<CdcRowDescriptor, CoGbkResult> element, + @Timestamp Instant timestamp, + OutputReceiver<Row> out) { + CdcRowDescriptor descriptor = element.getKey(); + + Set<String> pkFields = new HashSet<>(descriptor.getPrimaryKey().getSchema().getFieldNames()); + CoGbkResult result = element.getValue(); + + // should be okay to materialize these lists. a PK collision will likely be a handful of records + // at most + List<Row> deletes = Lists.newArrayList(result.getAll(DELETES)); + List<Row> inserts = Lists.newArrayList(result.getAll(INSERTS)); + + new RowResolver(pkFields, scanConfig.getMetadataColumns()) + .resolve( + deletes, + inserts, + (kind, row) -> { + Row projectedRow = rowFilter.filter(row); + out.builder( + CdcOutputUtils.outputRow( + scanConfig.getMetadataColumns(), + outputSchema, + descriptor.getCommitSnapshotId(), + descriptor.getSnapshotSequenceNumber(), + kind, + projectedRow)) + .setValueKind(kind) + .setTimestamp(timestamp) + .output(); + }); + } + + private static final class RowResolver extends CdcResolver<Row> { + private final Set<String> pkFields; + private final List<String> metadataColumns; + + RowResolver(Set<String> pkFields, List<String> metadataColumns) { + this.pkFields = pkFields; + this.metadataColumns = metadataColumns; + } + + @Override + protected int nonPkHash(Row element) { + int hash = 1; + for (String field : element.getSchema().getFieldNames()) { + if (pkFields.contains(field) + || (IcebergCdcMetadataColumns.isSupportedColumn(field) + && metadataColumns.contains(field))) { + continue; + } + hash = + 31 * hash + + Row.Equals.deepHashCode( + element.getValue(field), element.getSchema().getField(field).getType()); + } + return hash; + } + + @Override + protected boolean nonPkEquals(Row delete, Row insert) { Review Comment: See comment above. We only do this equality comparison on hash collision, so it's even more rare. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
