pvary commented on code in PR #12774: URL: https://github.com/apache/iceberg/pull/12774#discussion_r2222665248
########## core/src/main/java/org/apache/iceberg/io/ObjectModel.java: ########## @@ -0,0 +1,106 @@ +/* + * 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.io; + +import org.apache.iceberg.FileFormat; + +/** + * Direct conversion is used between file formats and engine internal formats for performance + * reasons. Object models encapsulate these conversions. + * + * <p>{@link ReadBuilder} is provided for reading data files stored in a given {@link FileFormat} + * into the engine specific object model. + * + * <p>{@link AppenderBuilder} is provided for writing engine specific object model to data/delete + * files stored in a given {@link FileFormat}. + * + * <p>Iceberg supports the following object models natively: + * + * <ul> + * <li>generic - reads and writes Iceberg {@link org.apache.iceberg.data.Record}s + * <li>spark - reads and writes Spark InternalRow records + * <li>spark-vectorized - vectorized reads for Spark columnar batches. Not supported for {@link + * FileFormat#AVRO} + * <li>flink - reads and writes Flink RowData records + * <li>arrow - vectorized reads for into Arrow columnar format. Only supported for {@link + * FileFormat#PARQUET} + * </ul> + * + * <p>Engines could implement their own object models to leverage Iceberg data file reading and + * writing capabilities. + * + * @param <E> the engine specific schema of the input data for the appender + */ +public interface ObjectModel<E> { Review Comment: Also put together a solution where the Engine specific format transformation is separated from the writer, and the engines need to take care of it separately. This is somewhat complicated on the implementation side (see: [RowDataTransformer](https://github.com/apache/iceberg/pull/12298/files#diff-562fa4cc369c908a157f59a9235fd3f389096451e7901686fba37c87b53dee08), and [InternalRowTransformer](https://github.com/apache/iceberg/pull/12298/files#diff-546f9dc30e3207d1d2bc0a2722976b55f5a04dcf85a22855e4f400500c317140)), but simplifies the API. @rdblue: Please check the proposed solution. I think this is what you have suggested -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
