rdblue commented on code in PR #16936: URL: https://github.com/apache/iceberg/pull/16936#discussion_r4170263025
########## core/src/main/java/org/apache/iceberg/MapBackedContentStats.java: ########## @@ -0,0 +1,206 @@ +/* + * 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.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 Types.StructType type; + private final Map<Integer, FieldStats<?>> statsById = Maps.newHashMap(); + + 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, MetricsConfig metricsConfig) { + Preconditions.checkArgument(tableSchema != null, "Invalid table schema: null"); + Preconditions.checkArgument(metricsConfig != null, "Invalid metrics config: null"); + this.type = StatsUtil.statsWriteSchema(tableSchema, metricsConfig); + } + + 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(); + 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 (!hasStats(fieldId)) { + return null; + } + + FieldStats<?> fieldStats = statsById.get(fieldId); + if (fieldStats == null) { + fieldStats = new MapBackedFieldStats<>(fieldId); + statsById.put(fieldId, fieldStats); + } + + return (FieldStats<T>) fieldStats; + } + + @Override + public Types.StructType type() { + return type; + } + + @Override + public ContentStats copy() { + throw new UnsupportedOperationException("copy is not implemented"); + } + + @Override + public ContentStats copy(Set<Integer> fieldIds) { + throw new UnsupportedOperationException("copy is not implemented"); + } + + private boolean hasStats(int id) { + return containsId(valueCounts, id) + || containsId(nullValueCounts, id) + || containsId(nanValueCounts, id) + || containsId(avgValueSizes, id) + || containsId(lowerBounds, id) + || containsId(upperBounds, id); + } + + private static boolean containsId(Map<Integer, ?> map, int id) { + return map != null && map.containsKey(id); + } + + /** Reusable {@link FieldStats} view over one field's entries in a {@link ContentFile}'s maps. */ + private class MapBackedFieldStats<T> implements FieldStats<T> { + private final int fieldId; + private final Types.StructType struct; + private final Type boundType; + + MapBackedFieldStats(int fieldId) { + Types.NestedField field = type.field(StatsUtil.toBaseId(fieldId)); Review Comment: We may also want to access this lazily to avoid building the set of field IDs and then generating the full content stats schema. This class mostly needs the stats type, which is based on the current schema's type. I would add a `StatsUtil` method to return the bound type for conversion, and then generate the `FieldStats` type lazily in `type()`. -- 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]
