aiborodin commented on code in PR #13340: URL: https://github.com/apache/iceberg/pull/13340#discussion_r2156138416
########## flink/v2.0/flink/src/main/java/org/apache/iceberg/flink/sink/dynamic/convert/RowDataConverter.java: ########## @@ -0,0 +1,89 @@ +/* + * 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.iceberg.flink.sink.dynamic.convert; + +import org.apache.flink.table.data.GenericRowData; +import org.apache.flink.table.data.RowData; +import org.apache.flink.table.types.logical.RowType; + +/** + * {@link RowDataConverter} is responsible to change the input {@link RowData} to make it compatible + * with the target schema. This is done when + * + * <ol> + * <li>The input schema has fewer fields than the target schema. + * <li>The table types are wider than the input type. + * <li>The field order differs for source and target schema. + * </ol> + * + * <p>The resolution is as follows: + * + * <ol> + * <li>In the first case, we would add a null values for the missing field (if the field is + * optional). + * <li>In the second case, we would convert the data for the input field to a wider type, e.g. int + * (input type) => long (table type). + * <li>In the third case, we would rearrange the input data to match the target table. + * </ol> + */ +public class RowDataConverter implements DataConverter { + private final RowData.FieldGetter[] fieldGetters; + private final DataConverter[] dataConverters; Review Comment: Please, see my comment above. Quasi code generation saves us extra 45% CPU time by caching field accessors. Breaking `RowDataEvolver` into multiple classes makes the code more readable compared to implicitly caching variables in lambdas. The object overhead is minimal as each converter would only store filed accessors and conversion lambdas. The cache overhead is minimal because it is an identity cache and same schema objects are already cached in `TableMetadataCache`. -- 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: issues-unsubscr...@iceberg.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@iceberg.apache.org For additional commands, e-mail: issues-h...@iceberg.apache.org
