amogh-jahagirdar commented on code in PR #15006: URL: https://github.com/apache/iceberg/pull/15006#discussion_r2730034212
########## core/src/main/java/org/apache/iceberg/DVUtil.java: ########## @@ -0,0 +1,146 @@ +/* + * 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; + +import java.io.IOException; +import java.io.UncheckedIOException; +import java.util.List; +import java.util.Map; +import java.util.Objects; +import java.util.concurrent.ExecutorService; +import java.util.stream.Collectors; +import org.apache.iceberg.deletes.BaseDVFileWriter; +import org.apache.iceberg.deletes.DVFileWriter; +import org.apache.iceberg.deletes.Deletes; +import org.apache.iceberg.deletes.PositionDeleteIndex; +import org.apache.iceberg.io.DeleteWriteResult; +import org.apache.iceberg.io.OutputFileFactory; +import org.apache.iceberg.relocated.com.google.common.base.Preconditions; +import org.apache.iceberg.util.Tasks; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +class DVUtil { + private static final Logger LOG = LoggerFactory.getLogger(DVUtil.class); + + private DVUtil() {} + + /** + * Merges duplicate DVs for the same data file and writes the merged DV Puffin files. + * + * @param duplicateDVsByReferencedFile map of data file location to duplicate DVs (all entries + * must have size > 1) + * @return newly merged DVs + */ + static List<DeleteFile> mergeDVsAndWrite( + TableOperations ops, + Map<String, List<DeleteFile>> duplicateDVsByReferencedFile, + String tableName, + ExecutorService threadpool) { + Map<String, PositionDeleteIndex> mergedIndices = + duplicateDVsByReferencedFile.entrySet().stream() + .collect( + Collectors.toMap( + Map.Entry::getKey, entry -> mergePositions(ops, entry.getValue(), threadpool))); + + return writeMergedDVs( + mergedIndices, duplicateDVsByReferencedFile, ops, tableName, ops.current().specsById()); + } + + // Merges the position indices for the duplicate DVs for a given referenced file + private static PositionDeleteIndex mergePositions( + TableOperations ops, List<DeleteFile> dvsForFile, ExecutorService pool) { + Preconditions.checkArgument(dvsForFile.size() > 1, "Expected more than 1 DV"); + PositionDeleteIndex[] duplicateDVIndices = new PositionDeleteIndex[dvsForFile.size()]; + Tasks.range(dvsForFile.size()) + .executeWith(pool) + .stopOnFailure() + .throwFailureWhenFinished() + .run( + i -> { + duplicateDVIndices[i] = Deletes.readDV(dvsForFile.get(i), ops.io(), ops.encryption()); + }); + PositionDeleteIndex mergedPositions = duplicateDVIndices[0]; + DeleteFile firstDV = dvsForFile.get(0); + for (int i = 1; i < duplicateDVIndices.length; i++) { + DeleteFile dv = dvsForFile.get(i); + Preconditions.checkArgument( + Objects.equals(dv.dataSequenceNumber(), firstDV.dataSequenceNumber()), + "Cannot merge duplicate added DVs when data sequence numbers are different, " + + "expected all to be added with sequence %s, but got %s", + firstDV.dataSequenceNumber(), + dv.dataSequenceNumber()); + + Preconditions.checkArgument( + dv.specId() == firstDV.specId(), + "Cannot merge duplicate added DVs when partition specs are different, " + + "expected all to be added with spec %s, but got %s", + firstDV.specId(), + dv.specId()); + + Preconditions.checkArgument( + Objects.equals(dv.partition(), firstDV.partition()), + "Cannot merge duplicate added DVs when partition tuples are different"); Review Comment: @rdblue let me know if you feel strongly about this check. While it is `StructLike` and doesn't guarantee an equals implementation, the way I look at it is the following: 1. Generally it'll be PartitionData which does do a type and value by value comparison. 2. Even if it ends up being a StructLike which doesn't override equals, then it's a reference equality which will worst case be a false positive and just fail the commit. Another rationale behind these checks is that if a writer produces duplicate DVs, there's also a chance of some kind of metadata record reuse issue from the writer and this felt like an easy sanity check. Alternatively, we could just simplify this and remove these validations by assuming that the duplicate DVs are OK by every other dimension. -- 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. 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