rdblue commented on code in PR #16936: URL: https://github.com/apache/iceberg/pull/16936#discussion_r4190069016
########## core/src/main/java/org/apache/iceberg/MapBackedContentStats.java: ########## @@ -0,0 +1,233 @@ +/* + * 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.nio.ByteBuffer; +import java.util.Map; +import java.util.Objects; +import java.util.Set; +import org.apache.iceberg.relocated.com.google.common.base.Preconditions; +import org.apache.iceberg.relocated.com.google.common.collect.Iterables; +import org.apache.iceberg.relocated.com.google.common.collect.Maps; +import org.apache.iceberg.relocated.com.google.common.collect.Sets; +import org.apache.iceberg.types.Conversions; +import org.apache.iceberg.types.Type; +import org.apache.iceberg.types.Types; + +/** Reusable {@link ContentStats} view over a {@link ContentFile}'s stat maps. */ +class MapBackedContentStats implements ContentStats { + private final Schema tableSchema; + private final Map<Integer, FieldStats<?>> statsById = Maps.newHashMap(); + + private Types.StructType type; + private Map<Integer, Long> valueCounts; + private Map<Integer, Long> nullValueCounts; + private Map<Integer, Long> nanValueCounts; + private Map<Integer, Integer> avgValueSizes; + private Map<Integer, ByteBuffer> lowerBounds; + private Map<Integer, ByteBuffer> upperBounds; + + MapBackedContentStats(Schema tableSchema) { + Preconditions.checkArgument(tableSchema != null, "Invalid table schema: null"); + this.tableSchema = tableSchema; + } + + MapBackedContentStats wrap(ContentFile<?> file) { + this.valueCounts = file.valueCounts(); + this.nullValueCounts = file.nullValueCounts(); + this.nanValueCounts = file.nanValueCounts(); + this.avgValueSizes = file.avgValueSizes(); + this.lowerBounds = file.lowerBounds(); + this.upperBounds = file.upperBounds(); + this.type = null; + statsById.clear(); + return this; + } + + @Override + public Iterable<FieldStats<?>> fieldStats() { + return Iterables.filter( + Iterables.transform( + type().fields(), field -> statsFor(StatsUtil.toFieldId(field.fieldId()))), + Objects::nonNull); + } + + @Override + @SuppressWarnings("unchecked") + public <T> FieldStats<T> statsFor(int fieldId) { + if (!containsFieldInMaps(fieldId) || type().field(StatsUtil.toBaseId(fieldId)) == null) { Review Comment: I don't think there is a need for the second check that the stats type includes the field. That's an expensive validation because it generates the stats type and it isn't necessary. It's only possible for these two checks to differ if the generated stats schema doesn't contain one of the fields. That happens when the field is nested in a map or list, or when the field isn't found in the schema. Since the stats exist, I think we should always return them if they are present in the maps. If map or list field stats made it in, they will be ignored in other ways like not being able to produce a predicate that references them. The only real failure case is when the field isn't in the schema so we can't determine its type for `MapBackedFieldStats`. But that case can be checked against the schema directly so we don't need to rely on `type()` here. -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
