vinothchandar commented on a change in pull request #4063: URL: https://github.com/apache/hudi/pull/4063#discussion_r756410413
########## File path: hudi-common/src/main/java/org/apache/hudi/common/model/debezium/PostgresDebeziumAvroPayload.java ########## @@ -0,0 +1,117 @@ +/* + * 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.hudi.common.model.debezium; + +import org.apache.hudi.common.util.Option; + +import org.apache.avro.Schema; +import org.apache.avro.generic.GenericData; +import org.apache.avro.generic.GenericRecord; +import org.apache.avro.generic.IndexedRecord; +import org.apache.log4j.LogManager; +import org.apache.log4j.Logger; + +import java.io.IOException; +import java.nio.ByteBuffer; +import java.nio.charset.StandardCharsets; +import java.util.List; + +/** + * Provides support for seamlessly applying changes captured via Debezium for PostgresDB. + * <p> + * Debezium change event types are determined for the op field in the payload + * <p> + * - For inserts, op=i + * - For deletes, op=d + * - For updates, op=u + * - For snapshort inserts, op=r + * <p> + * This payload implementation will issue matching insert, delete, updates against the hudi table + */ +public class PostgresDebeziumAvroPayload extends AbstractDebeziumAvroPayload { + + private static final Logger LOG = LogManager.getLogger(PostgresDebeziumAvroPayload.class); + public static final String DEBEZIUM_TOASTED_VALUE = "__debezium_unavailable_value"; + + public PostgresDebeziumAvroPayload(GenericRecord record, Comparable orderingVal) { + super(record, orderingVal); + } + + public PostgresDebeziumAvroPayload(Option<GenericRecord> record) { + super(record); + } + + private Long extractLSN(IndexedRecord record) { + GenericRecord genericRecord = (GenericRecord) record; + return (Long) genericRecord.get(DebeziumConstants.FLATTENED_LSN_COL_NAME); + } + + @Override + protected boolean shouldPickCurrentRecord(IndexedRecord currentRecord, IndexedRecord insertRecord, Schema schema) throws IOException { + Long currentSourceLSN = extractLSN(currentRecord); + Long insertSourceLSN = extractLSN(insertRecord); + + // Pick the current value in storage only if its LSN is latest compared to the LSN of the insert value + return insertSourceLSN < currentSourceLSN; + } + + @Override + public Option<IndexedRecord> combineAndGetUpdateValue(IndexedRecord currentValue, Schema schema) throws IOException { + // Specific to Postgres: If the updated record has TOASTED columns, + // we will need to keep the previous value for those columns + // see https://debezium.io/documentation/reference/connectors/postgresql.html#postgresql-toasted-values + Option<IndexedRecord> insertOrDeleteRecord = super.combineAndGetUpdateValue(currentValue, schema); + + if (insertOrDeleteRecord.isPresent()) { + List<Schema.Field> fields = insertOrDeleteRecord.get().getSchema().getFields(); + + fields.forEach(field -> { + // There are only four avro data types that have unconstrained sizes, which are + // NON-NULLABLE STRING, NULLABLE STRING, NON-NULLABLE BYTES, NULLABLE BYTES + boolean isToastedValue = + ( Review comment: can we make this more readable? break it into methods and fix formatting? -- 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]
