pvary commented on code in PR #12774: URL: https://github.com/apache/iceberg/pull/12774#discussion_r2163718598
########## core/src/main/java/org/apache/iceberg/io/ReadBuilder.java: ########## @@ -0,0 +1,136 @@ +/* + * 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 java.nio.ByteBuffer; +import java.util.Map; +import org.apache.iceberg.Schema; +import org.apache.iceberg.expressions.Expression; +import org.apache.iceberg.mapping.NameMapping; + +/** + * Builder interface for creating file readers across supported data file formats. The {@link + * FileAccessFactory} 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 <B> the concrete builder type for method chaining + * @param <D> the output data type produced by the reader + */ +public interface ReadBuilder<B extends ReadBuilder<B, D>, D> { + /** The configuration key for the batch size in the case of vectorized reads. */ + String RECORDS_PER_BATCH_KEY = "iceberg.records-per-batch"; + + /** + * Restricts the read to the given range: [start, start + length). + * + * @param newStart the start position for this read + * @param newLength the length of the range this read should scan + */ + B split(long newStart, long newLength); + + /** Read only the given columns. */ + B project(Schema newSchema); + + /** + * Pushes down the {@link Expression} filter for the reader to prevent reading unnecessary + * records. Some readers might not be able to filter some parts of the expression. In this case + * the reader might return unfiltered or partially filtered rows. It is the caller's + * responsibility to apply the filter again. + * + * @param newFilter the filter to set + * @param filterCaseSensitive whether the filtering is case-sensitive or not + */ + default B filter(Expression newFilter, boolean filterCaseSensitive) { + // Skip filtering if not available + return (B) this; + } + + /** + * Pushes down the {@link Expression} filter for the reader to prevent reading unnecessary + * records. Some readers might not be able to filter some part of the exception. In this case the + * reader might return unfiltered or partially filtered rows. It is the caller's responsibility to + * apply the filter again. The default implementation sets the filter to be case-sensitive. + * + * @param newFilter the filter to set + */ + default B filter(Expression newFilter) { + return filter(newFilter, true); + } + + /** + * Sets configuration key/value pairs for the reader. Reader builders should ignore configuration + * keys not known for them. + */ + default B set(String key, String value) { + // Skip configuration if not applicable + return (B) this; + } + + /** + * Sets multiple configuration key/value pairs for the reader. Reader builders should ignore + * configuration keys not known for them. + */ + default B set(Map<String, String> properties) { + properties.forEach(this::set); + return (B) this; + } + + /** + * Enables reusing the containers returned by the reader. Decreases pressure on GC. Readers could + * decide to ignore the user-provided setting if it is not supported by them. + */ + default B reuseContainers() { + // Skip container reuse configuration if not applicable + return (B) this; + } + + /** + * Accessors for constant field values. Used for calculating values in the result which are coming + * from metadata and not coming from the data files themselves. The keys of the map are the column + * ids, the values are the accessors generating the values. + */ + B constantFieldAccessors(Map<Integer, ?> constantFieldAccessors); + + /** Sets a mapping from external schema names to Iceberg type IDs. */ + B nameMapping(NameMapping newNameMapping); + + /** + * Sets the file encryption key used for reading the file. If the reader does not support + * encryption, then an exception should be thrown. + */ + default B fileEncryptionKey(ByteBuffer encryptionKey) { Review Comment: I followed the pattern that if something is not mandatory on the API then I provided a default implementation for it. -- 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
