pvary commented on code in PR #12774: URL: https://github.com/apache/iceberg/pull/12774#discussion_r2440383763
########## core/src/main/java/org/apache/iceberg/formats/FormatModelRegistry.java: ########## @@ -0,0 +1,240 @@ +/* + * 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.List; +import java.util.Map; +import java.util.Objects; +import org.apache.iceberg.DataFile; +import org.apache.iceberg.DeleteFile; +import org.apache.iceberg.FileContent; +import org.apache.iceberg.FileFormat; +import org.apache.iceberg.common.DynMethods; +import org.apache.iceberg.deletes.EqualityDeleteWriter; +import org.apache.iceberg.deletes.PositionDelete; +import org.apache.iceberg.deletes.PositionDeleteWriter; +import org.apache.iceberg.encryption.EncryptedOutputFile; +import org.apache.iceberg.io.DataWriter; +import org.apache.iceberg.io.InputFile; +import org.apache.iceberg.relocated.com.google.common.annotations.VisibleForTesting; +import org.apache.iceberg.relocated.com.google.common.base.Preconditions; +import org.apache.iceberg.relocated.com.google.common.collect.ImmutableList; +import org.apache.iceberg.relocated.com.google.common.collect.Maps; +import org.apache.iceberg.util.Pair; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * A registry that manages file-format-specific readers and writers through a unified object model + * factory interface. + * + * <p>This registry provides access to {@link ReadBuilder}s for data consumption and various writer + * builders: + * + * <ul> + * <li>{@link WriteBuilder} for basic file writing, + * <li>{@link DataWriteBuilder} for data files, + * <li>{@link EqualityDeleteWriteBuilder} for equality deletes, + * <li>{@link PositionDeleteWriteBuilder} for position deletes. + * </ul> + * + * The appropriate builder is selected based on {@link FileFormat} and object model name. + * + * <p>{@link FormatModel} objects are registered through {@link #register(FormatModel)} and used for + * creating readers and writers. Read builders are returned directly from the factory. Write + * builders may be wrapped in specialized content file writer implementations depending on the + * requested builder type. + */ +public final class FormatModelRegistry { + private static final Logger LOG = LoggerFactory.getLogger(FormatModelRegistry.class); + // The list of classes which are used for registering the reader and writer builders + private static final List<String> CLASSES_TO_REGISTER = ImmutableList.of(); + + private static final Map<Pair<FileFormat, Class<?>>, FormatModel<?, ?>> MODELS = + Maps.newConcurrentMap(); + + private FormatModelRegistry() {} + + /** + * Registers an {@link FormatModel} in this registry. + * + * <p>The {@link FormatModel} creates readers and writers for a specific combinations of file + * format (Parquet, ORC, Avro) and object model (for example: "generic", "spark", "flink", etc.). + * Registering custom factories allows integration of new data processing engines for the + * supported file formats with Iceberg's file access mechanisms. + * + * <p>Each factory must be uniquely identified by its combination of file format and object model + * name. This uniqueness constraint prevents ambiguity when selecting factories for read and write + * operations. + * + * @param formatModel the factory implementation to register + * @throws IllegalArgumentException if a factory is already registered for the combination of + * {@link FormatModel#format()} and {@link FormatModel#type()} + */ + public static void register(FormatModel<?, ?> formatModel) { + Pair<FileFormat, Class<?>> key = Pair.of(formatModel.format(), formatModel.type()); + + FormatModel<?, ?> existing = MODELS.get(key); + Preconditions.checkArgument( + existing == null || checkFormatModelEquals(existing, formatModel), + "Cannot register %s: %s is registered for format=%s type=%s schemaType=%s", + formatModel.getClass(), + existing == null ? null : existing.getClass(), + key.first(), + key.second(), + existing == null ? null : existing.schemaType()); + + MODELS.put(key, formatModel); + } + + private static boolean checkFormatModelEquals( + FormatModel<?, ?> model1, FormatModel<?, ?> model2) { + return Objects.equals(model1.getClass().getName(), model2.getClass().getName()) + && Objects.equals(model1.type().getName(), model2.type().getName()) + && Objects.equals( + model1.schemaType() == null ? null : model1.schemaType().getName(), + model2.schemaType() == null ? null : model2.schemaType().getName()); + } + + @SuppressWarnings("CatchBlockLogException") + private static void registerSupportedFormats() { + // Uses dynamic methods to call the `register` for the listed classes + for (String classToRegister : CLASSES_TO_REGISTER) { + try { + DynMethods.builder("register").impl(classToRegister).buildStaticChecked().invoke(); + } catch (NoSuchMethodException e) { + // failing to register a factory is normal and does not require a stack trace + LOG.info("Unable to register {}: {}", classToRegister, e.getMessage()); + } + } + } + + static { + registerSupportedFormats(); + } + + /** + * Returns a reader builder for the specified file format and object model. + * + * <p>The returned {@link ReadBuilder} provides a fluent interface for configuring how data is + * read from the input file and converted to the output objects. The builder supports + * configuration options like schema projection, predicate pushdown, batch size and encryption. + * + * @param format the file format (Parquet, Avro, ORC) that determines the parsing implementation + * @param type the output type + * @param inputFile source file to read data from + * @param <D> the type of data records the reader will produce + * @return a configured reader builder for the specified format and object model + */ + public static <D, S> ReadBuilder readBuilder( + FileFormat format, Class<D> type, InputFile inputFile) { + FormatModel<D, S> factory = factoryFor(format, type); + return factory.readBuilder(inputFile); + } + + /** + * Returns a writer builder for generating a {@link DataFile}. + * + * <p>The returned builder produces a writer that accepts records defined by the specified object + * model and persists them using the provided file format. Unlike basic writers, this writer + * collects file metadata during the writing process and generates a {@link DataFile} that can be + * used for table operations. + * + * @param format the file format used for writing + * @param type the input type + * @param outputFile destination for the written data + * @param <D> the type of data records the writer will accept + * @param <S> the type of the input schema for the writer + * @return a configured data write builder for creating a {@link DataWriter} + */ + public static <D, S> DataWriteBuilder<D, S> dataWriteBuilder( + FileFormat format, Class<D> type, EncryptedOutputFile outputFile) { + FormatModel<D, S> factory = factoryFor(format, type); + WriteBuilder writeBuilder = + factory.writeBuilder(outputFile.encryptingOutputFile()).content(FileContent.DATA); + return ContentFileWriteBuilderImpl.forDataFile( + writeBuilder, outputFile.encryptingOutputFile().location(), format); + } + + /** + * Creates a writer builder for generating a {@link DeleteFile} with equality deletes. + * + * <p>The returned builder produces a writer that accepts records defined by the specified object + * model and persists them using the given file format. The writer persists equality delete + * records that identify rows to be deleted based on the configured equality fields, producing a + * {@link DeleteFile} that can be used for table operations. + * + * @param format the file format used for writing + * @param type the input type + * @param outputFile destination for the written data + * @param <D> the type of data records the writer will accept + * @param <S> the type of the input schema for the writer + * @return a configured delete write builder for creating an {@link EqualityDeleteWriter} + */ + public static <D, S> EqualityDeleteWriteBuilder<D, S> equalityDeleteWriteBuilder( + FileFormat format, Class<D> type, EncryptedOutputFile outputFile) { + FormatModel<D, S> factory = factoryFor(format, type); + WriteBuilder writeBuilder = + factory + .writeBuilder(outputFile.encryptingOutputFile()) + .content(FileContent.EQUALITY_DELETES); + return ContentFileWriteBuilderImpl.forEqualityDelete( + writeBuilder, outputFile.encryptingOutputFile().location(), format); + } + + /** + * Creates a writer builder for generating a {@link DeleteFile} with position-based deletes. + * + * <p>The returned builder produces a writer that accepts records defined by the specified object + * model and persists them using the given file format. The writer accepts {@link PositionDelete} + * records that identify rows to be deleted by file path and position, producing a {@link + * DeleteFile} that can be used for table operations. + * + * @param format the file format used for writing + * @param outputFile destination for the written data + * @return a configured delete write builder for creating a {@link PositionDeleteWriter} + */ + public static PositionDeleteWriteBuilder positionDeleteWriteBuilder( + FileFormat format, EncryptedOutputFile outputFile) { + FormatModel<PositionDelete<?>, ?> factory = factoryForPositionDelete(format); + WriteBuilder writeBuilder = + factory + .writeBuilder(outputFile.encryptingOutputFile()) + .content(FileContent.POSITION_DELETES); + return ContentFileWriteBuilderImpl.forPositionDelete( + writeBuilder, outputFile.encryptingOutputFile().location(), format); + } + + @VisibleForTesting + static Map<Pair<FileFormat, Class<?>>, FormatModel<?, ?>> models() { + return MODELS; + } + + @SuppressWarnings("unchecked") + private static <D, S> FormatModel<D, S> factoryFor(FileFormat format, Class<D> type) { + FormatModel<D, S> model = ((FormatModel<D, S>) MODELS.get(Pair.of(format, type))); + Preconditions.checkNotNull(model, "Format model is not registered for %s and %s", format, type); Review Comment: Moved to `Preconditions.checkArgument` -- This is an automated message from the Apache Git Service. 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