gszadovszky commented on a change in pull request #796: URL: https://github.com/apache/parquet-mr/pull/796#discussion_r442758434
########## File path: parquet-cli/src/main/java/org/apache/parquet/cli/commands/TransCompressionCommand.java ########## @@ -0,0 +1,302 @@ +/* + * 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.parquet.cli.commands; + +import com.beust.jcommander.Parameter; +import com.beust.jcommander.Parameters; +import com.google.common.base.Preconditions; +import com.google.common.collect.Lists; +import org.apache.hadoop.fs.Path; +import org.apache.parquet.HadoopReadOptions; +import org.apache.parquet.ParquetReadOptions; +import org.apache.parquet.bytes.BytesInput; +import org.apache.parquet.cli.BaseCommand; +import org.apache.parquet.column.ColumnDescriptor; +import org.apache.parquet.column.impl.ColumnReadStoreImpl; +import org.apache.parquet.column.page.DictionaryPage; +import org.apache.parquet.column.page.PageReadStore; +import org.apache.parquet.column.statistics.Statistics; +import org.apache.parquet.compression.CompressionCodecFactory; +import org.apache.parquet.compression.CompressionCodecFactory.BytesInputCompressor; +import org.apache.parquet.compression.CompressionCodecFactory.BytesInputDecompressor; +import org.apache.parquet.format.DataPageHeader; +import org.apache.parquet.format.DataPageHeaderV2; +import org.apache.parquet.format.DictionaryPageHeader; +import org.apache.parquet.format.PageHeader; +import org.apache.parquet.format.Util; +import org.apache.parquet.format.converter.ParquetMetadataConverter; +import org.apache.parquet.hadoop.ParquetFileReader; +import org.apache.parquet.hadoop.ParquetFileWriter; +import org.apache.parquet.hadoop.metadata.BlockMetaData; +import org.apache.parquet.hadoop.metadata.ColumnChunkMetaData; +import org.apache.parquet.hadoop.metadata.ColumnPath; +import org.apache.parquet.hadoop.metadata.CompressionCodecName; +import org.apache.parquet.hadoop.metadata.ParquetMetadata; +import org.apache.parquet.hadoop.util.HadoopCodecs; +import org.apache.parquet.hadoop.util.HadoopInputFile; +import org.apache.parquet.internal.column.columnindex.ColumnIndex; +import org.apache.parquet.internal.column.columnindex.OffsetIndex; +import org.apache.parquet.io.InputFile; +import org.apache.parquet.io.ParquetEncodingException; +import org.apache.parquet.io.api.Converter; +import org.apache.parquet.io.api.GroupConverter; +import org.apache.parquet.io.api.PrimitiveConverter; +import org.apache.parquet.schema.MessageType; +import org.apache.parquet.schema.PrimitiveType; +import org.slf4j.Logger; + +import java.io.IOException; +import java.util.List; +import java.util.Map; +import java.util.stream.Collectors; + +import static org.apache.parquet.format.converter.ParquetMetadataConverter.NO_FILTER; + +@Parameters(commandDescription="Translate the compression from one to another") +public class TransCompressionCommand extends BaseCommand { + + public TransCompressionCommand(Logger console) { + super(console); + } + + @Parameter(description = "<input parquet file path>") + String input; + + @Parameter(description = "<output parquet file path>") + String output; + + @Parameter(description = "<new compression codec") + String codec; + + @Override + @SuppressWarnings("unchecked") + public int run() throws IOException { + Preconditions.checkArgument(input != null && output != null, + "Both input and output parquet file paths are required."); + + Preconditions.checkArgument(codec != null, + "The codec cannot be null"); + + Path inPath = new Path(input); + Path outPath = new Path(output); + CompressionCodecName codecName = CompressionCodecName.valueOf(codec); + + ParquetMetadata metaData = ParquetFileReader.readFooter(getConf(), inPath, NO_FILTER); + MessageType schema = metaData.getFileMetaData().getSchema(); + + try (TransParquetFileReader reader = new TransParquetFileReader(HadoopInputFile.fromPath(inPath, getConf()), HadoopReadOptions.builder(getConf()).build())) { + ParquetFileWriter writer = new ParquetFileWriter(getConf(), schema, outPath, ParquetFileWriter.Mode.CREATE); + writer.start(); + processBlocks(reader, writer, metaData, schema, metaData.getFileMetaData().getCreatedBy(), codecName); + writer.end(metaData.getFileMetaData().getKeyValueMetaData()); + } + return 0; + } + + @Override + public List<String> getExamples() { + return Lists.newArrayList( + "# Translate the compression from one to another", + " input.parquet output.parquet ZSTD" + ); + } + private void processBlocks(TransParquetFileReader reader, ParquetFileWriter writer, ParquetMetadata meta, MessageType schema, + String createdBy, CompressionCodecName codecName) throws IOException { + int blockIndex = 0; + PageReadStore store = reader.readNextRowGroup(); + while (store != null) { + writer.startBlock(store.getRowCount()); + BlockMetaData blockMetaData = meta.getBlocks().get(blockIndex); + List<ColumnChunkMetaData> columnsInOrder = blockMetaData.getColumns(); + Map<ColumnPath, ColumnDescriptor> descriptorsMap = schema.getColumns().stream().collect( + Collectors.toMap(x -> ColumnPath.get(x.getPath()), x -> x)); + for (int i = 0; i < columnsInOrder.size(); i += 1) { + ColumnChunkMetaData chunk = columnsInOrder.get(i); + ColumnReadStoreImpl crstore = new ColumnReadStoreImpl(store, new DumpGroupConverter(), schema, createdBy); + ColumnDescriptor columnDescriptor = descriptorsMap.get(chunk.getPath()); + writer.startColumn(columnDescriptor, crstore.getColumnReader(columnDescriptor).getTotalValueCount(), codecName); + processChunk(reader, writer, chunk, createdBy, codecName); + writer.endColumn(); + } + writer.endBlock(); + store = reader.readNextRowGroup(); + blockIndex++; + } + } + + private void processChunk(TransParquetFileReader reader, ParquetFileWriter writer, ColumnChunkMetaData chunk, + String createdBy, CompressionCodecName codecName) throws IOException { + CompressionCodecFactory codecFactory = HadoopCodecs.newFactory(0); + BytesInputDecompressor decompressor = codecFactory.getDecompressor(chunk.getCodec()); + BytesInputCompressor compressor = codecFactory.getCompressor(codecName); + ColumnIndex columnIndex = reader.readColumnIndex(chunk); + OffsetIndex offsetIndex = reader.readOffsetIndex(chunk); + + reader.setStreamPosition(chunk.getStartingPos()); + DictionaryPage dictionaryPage = null; + long readValues = 0; + Statistics statistics = null; + ParquetMetadataConverter converter = new ParquetMetadataConverter(); + int pageIndex = 0; + long totalChunkValues = chunk.getValueCount(); + while (readValues < totalChunkValues) { + PageHeader pageHeader = reader.readPageHeader(); + byte[] pageLoad; + switch (pageHeader.type) { + case DICTIONARY_PAGE: + if (dictionaryPage != null) { + throw new IOException("has more than one dictionary page in column chunk"); + } + DictionaryPageHeader dictPageHeader = pageHeader.dictionary_page_header; + pageLoad = translatePageLoad(reader, true, compressor, decompressor, pageHeader.getCompressed_page_size(), pageHeader.getUncompressed_page_size()); + writer.writeDictionaryPage(new DictionaryPage(BytesInput.from(pageLoad), + pageHeader.getUncompressed_page_size(), + converter.getEncoding(dictPageHeader.getEncoding()))); + break; + case DATA_PAGE: + DataPageHeader headerV1 = pageHeader.data_page_header; + pageLoad = translatePageLoad(reader, true, compressor, decompressor, pageHeader.getCompressed_page_size(), pageHeader.getUncompressed_page_size()); + statistics = convertStatistics(createdBy, chunk.getPrimitiveType(), headerV1.getStatistics(), columnIndex, pageIndex, converter); + readValues += headerV1.getNum_values(); + if (offsetIndex != null) { + long rowCount = 1 + offsetIndex.getLastRowIndex(pageIndex, totalChunkValues) - offsetIndex.getFirstRowIndex(pageIndex); + writer.writeDataPage(toIntWithCheck(headerV1.getNum_values()), + pageHeader.uncompressed_page_size, + BytesInput.from(pageLoad), + statistics, + toIntWithCheck(rowCount), + converter.getEncoding(headerV1.getRepetition_level_encoding()), + converter.getEncoding(headerV1.getDefinition_level_encoding()), + converter.getEncoding(headerV1.getEncoding())); + } else { + writer.writeDataPage(toIntWithCheck(headerV1.getNum_values()), + pageHeader.uncompressed_page_size, + BytesInput.from(pageLoad), + statistics, + converter.getEncoding(headerV1.getRepetition_level_encoding()), + converter.getEncoding(headerV1.getDefinition_level_encoding()), + converter.getEncoding(headerV1.getEncoding())); + } + pageIndex++; + break; + case DATA_PAGE_V2: + DataPageHeaderV2 headerV2 = pageHeader.data_page_header_v2; + int rlLength = headerV2.getRepetition_levels_byte_length(); + BytesInput rlLevels = readBlock(rlLength, reader); + int dlLength = headerV2.getDefinition_levels_byte_length(); + BytesInput dlLevels = readBlock(dlLength, reader); + int payLoadLength = pageHeader.getCompressed_page_size() - rlLength - dlLength; + int rawDataLength = pageHeader.getUncompressed_page_size() - rlLength - dlLength; + pageLoad = translatePageLoad(reader, headerV2.is_compressed, compressor, decompressor, payLoadLength, rawDataLength); + statistics = convertStatistics(createdBy, chunk.getPrimitiveType(), headerV2.getStatistics(), columnIndex, pageIndex, converter); + readValues += headerV2.getNum_values(); + writer.writeDataPageV2(headerV2.getNum_rows(), + headerV2.getNum_nulls(), + headerV2.getNum_values(), + rlLevels, + dlLevels, + converter.getEncoding(headerV2.getEncoding()), + BytesInput.from(pageLoad), + pageHeader.uncompressed_page_size - rlLength - dlLength, + statistics); + pageIndex++; + break; + default: + break; + } + } + } + + private Statistics convertStatistics(String createdBy, PrimitiveType type, org.apache.parquet.format.Statistics pageStatistics, + ColumnIndex columnIndex, int pageIndex, ParquetMetadataConverter converter) throws IOException { + if (pageStatistics != null) { + return converter.fromParquetStatistics(createdBy, pageStatistics, type); + } else if (columnIndex != null) { + if (columnIndex.getNullPages() == null) { + throw new IOException("columnIndex has null variable 'nullPages' which indicates corrupted data for type: " + type.getName()); + } + if (pageIndex > columnIndex.getNullPages().size()) { + throw new IOException("There are more pages " + pageIndex + " found in the column than in the columnIndex " + columnIndex.getNullPages().size()); + } + org.apache.parquet.column.statistics.Statistics.Builder statsBuilder = org.apache.parquet.column.statistics.Statistics.getBuilderForReading(type); + statsBuilder.withNumNulls(columnIndex.getNullCounts().get(pageIndex)); + + if (!columnIndex.getNullPages().get(pageIndex)) { + statsBuilder.withMin(columnIndex.getMinValues().get(pageIndex).array().clone()); + statsBuilder.withMax(columnIndex.getMaxValues().get(pageIndex).array().clone()); + } + return statsBuilder.build(); Review comment: You are completely right, I've forgot about my own implementation :) Then, just one comment for this code part. I think, column index is more reliable so I would use it for generating statistics at the first place. ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
