johnjcasey commented on code in PR #24806: URL: https://github.com/apache/beam/pull/24806#discussion_r1059174542
########## sdks/java/io/file-schema-transform/src/main/java/org/apache/beam/sdk/io/fileschematransform/FileWriteSchemaTransformProvider.java: ########## @@ -0,0 +1,114 @@ +/* + * 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.beam.sdk.io.fileschematransform; + +import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkState; + +import java.util.Collections; +import java.util.List; +import java.util.Map; +import java.util.Optional; +import org.apache.beam.sdk.schemas.transforms.SchemaTransform; +import org.apache.beam.sdk.schemas.transforms.TypedSchemaTransformProvider; +import org.apache.beam.sdk.transforms.PTransform; +import org.apache.beam.sdk.values.PCollection; +import org.apache.beam.sdk.values.PCollectionRowTuple; +import org.apache.beam.sdk.values.PDone; +import org.apache.beam.sdk.values.Row; + +public class FileWriteSchemaTransformProvider + extends TypedSchemaTransformProvider<FileWriteSchemaTransformConfiguration> { + + private static final String IDENTIFIER = "beam:schematransform:org.apache.beam:file_write:v1"; + private static final String INPUT_TAG = "input"; + + @Override + protected Class<FileWriteSchemaTransformConfiguration> configurationClass() { + return FileWriteSchemaTransformConfiguration.class; + } + + @Override + protected SchemaTransform from(FileWriteSchemaTransformConfiguration configuration) { + return new FileWriteSchemaTransform(configuration); + } + + @Override + public String identifier() { + return IDENTIFIER; + } + + @Override + public List<String> inputCollectionNames() { + return Collections.singletonList(INPUT_TAG); + } + + @Override + public List<String> outputCollectionNames() { + return Collections.emptyList(); + } + + static class FileWriteSchemaTransform extends PTransform<PCollectionRowTuple, PCollectionRowTuple> + implements SchemaTransform { + + final FileWriteSchemaTransformConfiguration configuration; + + FileWriteSchemaTransform(FileWriteSchemaTransformConfiguration configuration) { + this.configuration = configuration; + } + + @Override + public PCollectionRowTuple expand(PCollectionRowTuple input) { + if (input.getAll().isEmpty()) { + throw new IllegalArgumentException( + String.format( + "%s expects a single %s tagged PCollection<Row> input", + FileWriteSchemaTransform.class.getName(), INPUT_TAG)); + } + + PCollection<Row> rowInput = input.get(INPUT_TAG); + + PTransform<PCollection<Row>, PDone> transform = Review Comment: I don't have the information on hand, but PDone is no longer good practice. Being able to staple further work on the end of a write is a valuable feature, and PDone mostly prevents that. I can't speak to performance reasons, but I'd naively assume that if there is no work to be done after a transform, it won't matter what types it emits -- 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]
