org.apache.hudi.common.table.log.LogReaderUtils Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* 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,
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*/
package org.apache.hudi.common.table.log;
import org.apache.hudi.common.fs.FSUtils;
import org.apache.hudi.common.model.HoodieLogFile;
import org.apache.hudi.common.table.HoodieTableMetaClient;
import org.apache.hudi.common.table.log.HoodieLogFormat.Reader;
import org.apache.hudi.common.table.log.block.HoodieDataBlock;
import org.apache.hudi.common.table.log.block.HoodieLogBlock;
import org.apache.hudi.common.table.log.block.HoodieLogBlock.HeaderMetadataType;
import org.apache.hudi.common.table.timeline.HoodieActiveTimeline;
import org.apache.hudi.common.table.timeline.HoodieTimeline;
import org.apache.hudi.common.util.collection.Pair;
import org.apache.avro.Schema;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import java.io.IOException;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
/**
* Utils class for performing various log file reading operations.
*/
public class LogReaderUtils {
private static Schema readSchemaFromLogFileInReverse(FileSystem fs, HoodieActiveTimeline activeTimeline, HoodieLogFile hoodieLogFile)
throws IOException {
// set length for the HoodieLogFile as it will be leveraged by HoodieLogFormat.Reader with reverseReading enabled
Reader reader = HoodieLogFormat.newReader(fs, hoodieLogFile, null, true, true);
Schema writerSchema = null;
HoodieTimeline completedTimeline = activeTimeline.getCommitsTimeline().filterCompletedInstants();
while (reader.hasPrev()) {
HoodieLogBlock block = reader.prev();
if (block instanceof HoodieDataBlock) {
HoodieDataBlock lastBlock = (HoodieDataBlock) block;
if (completedTimeline
.containsOrBeforeTimelineStarts(lastBlock.getLogBlockHeader().get(HeaderMetadataType.INSTANT_TIME))) {
writerSchema = new Schema.Parser().parse(lastBlock.getLogBlockHeader().get(HeaderMetadataType.SCHEMA));
break;
}
}
}
reader.close();
return writerSchema;
}
public static Schema readLatestSchemaFromLogFiles(String basePath, List logFiles, Configuration config)
throws IOException {
HoodieTableMetaClient metaClient = HoodieTableMetaClient.builder().setConf(config).setBasePath(basePath).build();
List deltaPaths = logFiles.stream().sorted(HoodieLogFile.getReverseLogFileComparator()).map(s -> s.getPath().toString())
.collect(Collectors.toList());
if (deltaPaths.size() > 0) {
Map deltaFilePathToFileStatus = logFiles.stream().map(entry -> Pair.of(entry.getPath().toString(), entry))
.collect(Collectors.toMap(Pair::getKey, Pair::getValue));
for (String logPath : deltaPaths) {
FileSystem fs = FSUtils.getFs(logPath, config);
Schema schemaFromLogFile = readSchemaFromLogFileInReverse(fs, metaClient.getActiveTimeline(), deltaFilePathToFileStatus.get(logPath));
if (schemaFromLogFile != null) {
return schemaFromLogFile;
}
}
}
return null;
}
}