pvary commented on code in PR #12298: URL: https://github.com/apache/iceberg/pull/12298#discussion_r2718578934
########## core/src/main/java/org/apache/iceberg/formats/ReadBuilder.java: ########## @@ -0,0 +1,113 @@ +/* + * 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.formats; + +import java.util.Map; +import org.apache.iceberg.Schema; +import org.apache.iceberg.expressions.Expression; +import org.apache.iceberg.io.CloseableIterable; +import org.apache.iceberg.mapping.NameMapping; + +/** + * Builder interface for creating file readers across supported data file formats. The {@link + * FormatModel} implementations provides appropriate {@link ReadBuilder} instances + * + * <p>The {@link ReadBuilder} follows the builder pattern to configure and create {@link + * CloseableIterable} instances that read data from source files. Configuration options include + * schema projection, predicate filtering, record batching, and encryption settings. + * + * <p>This interface is directly exposed to users for parameterizing readers. + * + * @param <D> the output data type produced by the reader + * @param <S> the type of the schema for the output data type + */ +public interface ReadBuilder<D, S> { + /** + * Restricts the read to the given range: [start, start + length). + * + * @param start the start position for this read + * @param length the length of the range this read should scan + */ + ReadBuilder<D, S> split(long start, long length); + + /** Set the projection schema. */ + ReadBuilder<D, S> project(Schema schema); + + /** Sets the expected output schema. If not provided derived from the {@link #project(Schema)}. */ Review Comment: > builder won't do anything to create an engine schema from an Iceberg schema. I wanted to highlight that setting the `outputSchema` is not mandatory. If not provided the builder will generate a default representation. I agree that better doc is needed. I will reword and add the examples. I think projection is required anyway, so I updated the javadoc accordingly. -- 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]
