kbendick commented on a change in pull request #1213: URL: https://github.com/apache/iceberg/pull/1213#discussion_r460589483
########## File path: core/src/main/java/org/apache/iceberg/io/PartitionedFanoutWriter.java ########## @@ -0,0 +1,73 @@ +/* + * 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.io.IOException; +import java.util.Iterator; +import java.util.Map; +import org.apache.iceberg.FileFormat; +import org.apache.iceberg.PartitionKey; +import org.apache.iceberg.PartitionSpec; +import org.apache.iceberg.relocated.com.google.common.collect.Maps; + +public abstract class PartitionedFanoutWriter<T> extends BaseTaskWriter<T> { + private final Map<PartitionKey, RollingFileAppender> writers = Maps.newHashMap(); + + public PartitionedFanoutWriter(PartitionSpec spec, FileFormat format, FileAppenderFactory<T> appenderFactory, + OutputFileFactory fileFactory, FileIO io, long targetFileSize) { + super(spec, format, appenderFactory, fileFactory, io, targetFileSize); + } + + /** + * Create a PartitionKey from the values in row. + * <p> + * Any PartitionKey returned by this method can be reused by the implementation. + * + * @param row a data row + */ + protected abstract PartitionKey partition(T row); + + @Override + public void write(T row) throws IOException { + PartitionKey partitionKey = partition(row); + + RollingFileAppender writer = writers.get(partitionKey); + if (writer == null) { + // NOTICE: we need to copy a new partition key here, in case of messing up the keys in writers. + PartitionKey copiedKey = partitionKey.copy(); + writer = new RollingFileAppender(copiedKey); + writers.put(copiedKey, writer); Review comment: Ah ok. I hadn't realized that was the plan. I wrote a parquet writer for flink way back when flink did not support it and outputting files on checkpoint was the only real solution that I could come up with. It also involved forking the base parquet-library, so we wound up abandoning it as we don't really have the engineering head count to be constantly updating and maintaining something like that. Despite the fact that Flink can now support writing parquet files etc, this is why I'm interested in this project. That and then the numerous additions to the data lake that the project supports. Thanks for the info @rdblue! ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
