rahulsmahadev commented on code in PR #17622: URL: https://github.com/apache/iceberg/pull/17622#discussion_r4225807725
########## spark/v4.1/spark/src/main/java/org/apache/iceberg/spark/actions/RepairMetrics.java: ########## @@ -0,0 +1,195 @@ +/* + * 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.spark.actions; + +import static org.apache.iceberg.TableProperties.DEFAULT_NAME_MAPPING; + +import java.nio.ByteBuffer; +import java.util.List; +import java.util.Map; +import java.util.Objects; +import org.apache.iceberg.ContentFile; +import org.apache.iceberg.DataFile; +import org.apache.iceberg.DataFiles; +import org.apache.iceberg.DeleteFile; +import org.apache.iceberg.FileContent; +import org.apache.iceberg.FileFormat; +import org.apache.iceberg.FileMetadata; +import org.apache.iceberg.Metrics; +import org.apache.iceberg.MetricsConfig; +import org.apache.iceberg.PartitionSpec; +import org.apache.iceberg.Table; +import org.apache.iceberg.avro.Avro; +import org.apache.iceberg.io.InputFile; +import org.apache.iceberg.mapping.NameMapping; +import org.apache.iceberg.mapping.NameMappingParser; +import org.apache.iceberg.orc.OrcMetrics; +import org.apache.iceberg.parquet.ParquetUtil; +import org.apache.iceberg.relocated.com.google.common.collect.ImmutableMap; + +/** + * Reads the statistics of data and delete files and compares them against the statistics recorded + * in manifest entries. + * + * <p>Recomputed statistics always respect the metrics config of the table so that they are + * comparable with the stored statistics. + */ +class RepairMetrics { + + private RepairMetrics() {} + + /** Returns the name mapping of the table, or null if the table does not define one. */ + static NameMapping nameMapping(Table table) { + String mapping = table.properties().get(DEFAULT_NAME_MAPPING); + return mapping != null ? NameMappingParser.fromJson(mapping) : null; + } + + /** + * Returns the metrics config to use when recomputing the statistics of the given file. + * + * <p>Position delete files record statistics for the path and position columns only, which is a + * fixed config rather than the config of the table. + */ + static MetricsConfig metricsConfig(Table table, FileContent content) { + return content == FileContent.POSITION_DELETES + ? MetricsConfig.forPositionDelete() + : MetricsConfig.forTable(table); + } + + /** + * Returns true if the statistics of the file can be recomputed by reading it. + * + * <p>Deletion vectors are stored as blobs inside a Puffin file, so their statistics cannot be + * derived by reading the file they are stored in. + */ + static boolean supportsMetrics(ContentFile<?> file) { + FileFormat format = file.format(); + return format == FileFormat.PARQUET || format == FileFormat.ORC || format == FileFormat.AVRO; + } + + /** Recomputes the statistics of a file by reading it. */ + static Metrics readMetrics( + InputFile input, ContentFile<?> file, MetricsConfig config, NameMapping mapping) { + switch (file.format()) { + case PARQUET: + return ParquetUtil.fileMetrics(input, config, mapping); + case ORC: + return OrcMetrics.fromInputFile(input, config, mapping); + case AVRO: + // Avro does not record column statistics, only the number of records is recoverable + return new Metrics(Avro.rowCount(input), null, null, null, null); + default: + throw new UnsupportedOperationException("Cannot read metrics of format: " + file.format()); + } + } + + /** + * Returns true if the statistics recorded for the file differ from the statistics of the file + * itself. + * + * <p>The record count and the file size are always compared. Column level statistics are only + * compared when requested, because a table whose metrics config changed after a file was written + * reports statistics that legitimately differ from the recomputed ones. + */ + static boolean statsAreIncorrect( + ContentFile<?> file, Metrics metrics, long fileSizeInBytes, boolean compareColumnMetrics) { + if (file.fileSizeInBytes() != fileSizeInBytes) { + return true; + } + + if (metrics.recordCount() != null && file.recordCount() != metrics.recordCount()) { + return true; + } + + if (!compareColumnMetrics) { + return false; + } + + return !countsMatch(file.columnSizes(), metrics.columnSizes()) + || !countsMatch(file.valueCounts(), metrics.valueCounts()) + || !countsMatch(file.nullValueCounts(), metrics.nullValueCounts()) + || !countsMatch(file.nanValueCounts(), metrics.nanValueCounts()) Review Comment: Done! -- This is an automated message from the Apache Git Service. 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