shangxinli commented on a change in pull request #775: URL: https://github.com/apache/parquet-mr/pull/775#discussion_r411033348
########## File path: parquet-hadoop/src/main/java/org/apache/parquet/hadoop/RowGroupMerger.java ########## @@ -0,0 +1,634 @@ +/* + * 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.hadoop; + +import static java.lang.String.format; +import static org.apache.parquet.column.ValuesType.DEFINITION_LEVEL; +import static org.apache.parquet.column.ValuesType.REPETITION_LEVEL; +import static org.apache.parquet.column.ValuesType.VALUES; +import static org.apache.parquet.hadoop.ParquetFileWriter.getColumnsInOrder; + +import java.io.IOException; +import java.io.UncheckedIOException; +import java.nio.ByteBuffer; +import java.util.ArrayList; +import java.util.Collections; +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import java.util.Map.Entry; +import java.util.function.BiConsumer; +import java.util.function.Consumer; +import java.util.stream.Collectors; + +import org.apache.hadoop.conf.Configuration; +import org.apache.parquet.Preconditions; +import org.apache.parquet.bytes.ByteBufferInputStream; +import org.apache.parquet.bytes.BytesInput; +import org.apache.parquet.column.ColumnDescriptor; +import org.apache.parquet.column.Dictionary; +import org.apache.parquet.column.Encoding; +import org.apache.parquet.column.ParquetProperties; +import org.apache.parquet.column.page.DataPage; +import org.apache.parquet.column.page.DataPageV1; +import org.apache.parquet.column.page.DataPageV2; +import org.apache.parquet.column.page.DictionaryPage; +import org.apache.parquet.column.page.PageReadStore; +import org.apache.parquet.column.page.PageReader; +import org.apache.parquet.column.values.ValuesReader; +import org.apache.parquet.column.values.ValuesWriter; +import org.apache.parquet.compression.CompressionCodecFactory; +import org.apache.parquet.hadoop.metadata.BlockMetaData; +import org.apache.parquet.hadoop.metadata.ColumnChunkMetaData; +import org.apache.parquet.hadoop.metadata.CompressionCodecName; +import org.apache.parquet.io.InputFile; +import org.apache.parquet.io.ParquetDecodingException; +import org.apache.parquet.schema.MessageType; +import org.apache.parquet.schema.PrimitiveType; + +class RowGroupMerger { + + private final MessageType schema; + private final CodecFactory.BytesInputCompressor compressor; + private final ParquetProperties parquetProperties; + + RowGroupMerger(MessageType schema, CompressionCodecName compression, boolean useV2ValueWriter) { + this(schema, new Configuration(), compression, useV2ValueWriter); + } + + RowGroupMerger(MessageType schema, Configuration conf, CompressionCodecName compression, boolean useV2ValueWriter) { + this(schema, conf, compression, createParquetProperties(useV2ValueWriter)); + } + + RowGroupMerger(MessageType schema, Configuration conf, CompressionCodecName compression, ParquetProperties parquetProperties) { + this.schema = schema; + this.parquetProperties = parquetProperties; + this.compressor = new CodecFactory(conf, this.parquetProperties.getPageSizeThreshold()).getCompressor(compression); + } + + /** + * Merges the row groups making sure that new row groups do not exceed the supplied maxRowGroupSize + * + * @param inputFiles input files to merge + * @param maxRowGroupSize the max limit for new blocks + * @param writer writer to write the new blocks to + * @throws IOException if an IO error occurs + */ + void merge(List<InputFile> inputFiles, final long maxRowGroupSize, ParquetFileWriter writer) throws IOException { + + SizeEstimator estimator = new SizeEstimator(compressor.getCodecName() != CompressionCodecName.UNCOMPRESSED); + MutableMergedBlock mergedBlock = null; + for (InputFile file : inputFiles) { + try (ParquetFileReader reader = ParquetFileReader.open(file)) { + + for (BlockMetaData blockMeta : reader.getRowGroups()) { + PageReadStore group = reader.readNextRowGroup(); + Preconditions.checkState(group != null, + "number of groups returned by FileReader does not match metadata"); + + if (mergedBlock != null && mergedBlock.getCompressedBytesSize() + estimator.estimate(blockMeta) > maxRowGroupSize) { + saveBlockTo(mergedBlock, writer); + mergedBlock = null; + } + + if (mergedBlock == null && estimator.estimate(blockMeta) > maxRowGroupSize) { + //save it directly without re encoding it + saveBlockTo(ReadOnlyMergedBlock.of(blockMeta, group, schema, compressor), writer); + continue; + } + + if (mergedBlock == null) { + mergedBlock = new MutableMergedBlock(schema); + } + + long sizeBeforeMerge = mergedBlock.getCompressedBytesSize(); + mergedBlock.merge(blockMeta, group); + //update our estimator + long currentBlockEffect = mergedBlock.getCompressedBytesSize() - sizeBeforeMerge; + estimator.update(currentBlockEffect, blockMeta); + } + } + } + if (mergedBlock != null) + saveBlockTo(mergedBlock, writer); + } + + + private static void saveBlockTo(MergedBlock block, ParquetFileWriter writer) { + try { + writer.startBlock(block.rowCount()); + + for (MergedColumn col : block.columnsInOrder()) { + writer.startColumn(col.getColumnDesc(), col.getValueCount(), col.getCompression()); + + col.writeDictionaryPageTo(writer); + col.writeDataPagesTo(writer); + + writer.endColumn(); + } + + writer.endBlock(); + } catch (IOException e) { + throw new UncheckedIOException(e); + } + } + + private static ParquetProperties createParquetProperties(boolean useV2Writer) { + ParquetProperties.Builder builder = ParquetProperties.builder(); + if (useV2Writer) { + builder.withWriterVersion(ParquetProperties.WriterVersion.PARQUET_2_0); + } + return builder.build(); + } + + private BytesInput compress(BytesInput bytes) { + return compress(bytes, compressor); + } + + private static BytesInput compress(BytesInput bytes, CompressionCodecFactory.BytesInputCompressor compressor) { + try { + return BytesInput.copy(compressor.compress(bytes));//we copy as some compressors use shared memory + } catch (IOException e) { + throw new UncheckedIOException(e); + } + } + + private static BiConsumer<ValuesReader, ValuesWriter> createWritingBridge(PrimitiveType.PrimitiveTypeName typeName) { + switch (typeName) { + case FIXED_LEN_BYTE_ARRAY: + case INT96: + case BINARY: + return (src, dest) -> dest.writeBytes(src.readBytes()); + case BOOLEAN: + return (src, dest) -> dest.writeBoolean(src.readBoolean()); + case DOUBLE: + return (src, dest) -> dest.writeDouble(src.readDouble()); + case FLOAT: + return (src, dest) -> dest.writeFloat(src.readFloat()); + case INT32: + return (src, dest) -> dest.writeInteger(src.readInteger()); + case INT64: + return (src, dest) -> dest.writeLong(src.readLong()); + default: + throw new RuntimeException("Unsupported column primitive type: " + typeName.name()); + } + } + + private static void writePageTo(DataPage dataPage, ParquetFileWriter writer) { + dataPage.accept(new DataPage.Visitor<Void>() { + @Override + public Void visit(DataPageV1 page) { + try { + if (page.getIndexRowCount().isPresent()) { + writer.writeDataPage(page.getValueCount(), page.getUncompressedSize(), + page.getBytes(), page.getStatistics(), page.getIndexRowCount().get(), page.getRlEncoding(), + page.getDlEncoding(), page.getValueEncoding()); + + } else { + writer.writeDataPage(page.getValueCount(), page.getUncompressedSize(), + page.getBytes(), page.getStatistics(), page.getRlEncoding(), + page.getDlEncoding(), page.getValueEncoding()); + } + } catch (IOException e) { + throw new UncheckedIOException(e); + } + return null; + } + + @Override + public Void visit(DataPageV2 page) { + try { + writer.writeDataPageV2(page.getRowCount(), page.getNullCount(), page.getValueCount(), + page.getRepetitionLevels(), page.getDefinitionLevels(), page.getDataEncoding(), + page.getData(), page.getUncompressedSize(), page.getStatistics()); + } catch (IOException e) { + throw new UncheckedIOException(e); + } + return null; + } + }); + } + + private static DictionaryPage getCompressedDictionary(DictionaryPage dictionary, CompressionCodecFactory.BytesInputCompressor compressor) { + return new DictionaryPage( + compress(dictionary.getBytes(), compressor), + dictionary.getUncompressedSize(), + dictionary.getDictionarySize(), + dictionary.getEncoding()); + } + + private interface MergedBlock { + long rowCount(); + + List<MergedColumn> columnsInOrder(); + } + + private interface MergedColumn { + long getValueCount(); + + CompressionCodecName getCompression(); + + ColumnDescriptor getColumnDesc(); + + void writeDataPagesTo(ParquetFileWriter writer); + + void writeDictionaryPageTo(ParquetFileWriter writer) throws IOException; + } + + private class MutableMergedBlock implements MergedBlock { + + private final Map<ColumnDescriptor, MutableMergedColumn> columns = new HashMap<>(); + private final MessageType schema; + private long recordCount; + private long compressedBytesSize; + + private MutableMergedBlock(MessageType schema) { + this.schema = schema; + } + + @Override + public long rowCount() { + return recordCount; + } + + private long getCompressedBytesSize() { + return compressedBytesSize; + } + + @Override + public List<MergedColumn> columnsInOrder() { + return schema.getColumns() + .stream() + .map(columns::get) + .collect(Collectors.toList()); + } + + MutableMergedColumn getOrCreateColumn(ColumnDescriptor column) { + return columns.computeIfAbsent(column, desc -> new MutableMergedColumn(desc, this::addCompressedBytes)); + } + + void addRowCount(long rowCount) { + recordCount += rowCount; + } + + void addCompressedBytes(long size) { + compressedBytesSize += size; + } + + void merge(BlockMetaData blockMeta, PageReadStore group) throws IOException { + for (Entry<ColumnDescriptor, ColumnChunkMetaData> col : getColumnsInOrder(blockMeta, schema, false)) { + + MutableMergedColumn column = getOrCreateColumn(col.getKey()); + PageReader columnReader = group.getPageReader(col.getKey()); + + DictionaryPage dictPage = columnReader.readDictionaryPage(); + Dictionary decodedDictionary = null; + if (dictPage != null) { + decodedDictionary = dictPage.getEncoding().initDictionary(column.getColumnDesc(), dictPage); + } + + //read all pages in this column chunk + DataPage data; + while ((data = columnReader.readPage()) != null) { + column.addPage(data, decodedDictionary); + } + } + addRowCount(blockMeta.getRowCount()); + } + } + + private static class ReadOnlyMergedBlock implements MergedBlock { + private final List<MergedColumn> columns; + private final long recordCount; + + private ReadOnlyMergedBlock(List<MergedColumn> columns, long recordCount) { + this.columns = Collections.unmodifiableList(columns); + this.recordCount = recordCount; + } + + @Override + public long rowCount() { + return recordCount; + } + + @Override + public List<MergedColumn> columnsInOrder() { + return columns; + } + + static ReadOnlyMergedBlock of(BlockMetaData blockMeta, PageReadStore group, MessageType schema, + CompressionCodecFactory.BytesInputCompressor compressor) { + List<MergedColumn> columns = new ArrayList<>(); + for (Entry<ColumnDescriptor, ColumnChunkMetaData> col : getColumnsInOrder(blockMeta, schema, false)) { + + List<DataPage> pages = new ArrayList<>(); + PageReader columnReader = group.getPageReader(col.getKey()); + + DictionaryPage dictPage = columnReader.readDictionaryPage(); + if (dictPage != null) { + dictPage = getCompressedDictionary(dictPage, compressor); + } + + //read all pages in this column chunk + DataPage data; + while ((data = columnReader.readPage()) != null) { + + data = data.accept(new DataPage.Visitor<DataPage>() { + @Override + public DataPage visit(DataPageV1 pageV1) { + + return new DataPageV1(compress(pageV1.getBytes(), compressor), pageV1.getValueCount(), + pageV1.getUncompressedSize(), pageV1.getFirstRowIndex().orElse(-1L), + pageV1.getIndexRowCount().orElse(-1), pageV1.getStatistics(), pageV1.getRlEncoding(), + pageV1.getDlEncoding(), pageV1.getValueEncoding()); + } + + @Override + public DataPage visit(DataPageV2 pageV2) { + + return DataPageV2.compressed( + pageV2.getRowCount(), pageV2.getNullCount(), pageV2.getValueCount(), + pageV2.getRepetitionLevels(), pageV2.getDefinitionLevels(), pageV2.getDataEncoding(), + compress(pageV2.getData(), compressor), pageV2.getUncompressedSize(), pageV2.getStatistics()); + } + }); + + pages.add(data); + } + + ReadOnlyMergedColumn column = new ReadOnlyMergedColumn(pages, dictPage, col.getKey(), + col.getValue().getValueCount(), compressor.getCodecName()); + + columns.add(column); + } + return new ReadOnlyMergedBlock(columns, blockMeta.getRowCount()); + } + } + + private static class ReadOnlyMergedColumn implements MergedColumn { + private final List<DataPage> pages; + private final DictionaryPage dictionary; + private final ColumnDescriptor columnDesc; + private final long valueCount; + private final CompressionCodecName codecName; + + private ReadOnlyMergedColumn(List<DataPage> pages, DictionaryPage dictionary, ColumnDescriptor columnDesc, + long valueCount, CompressionCodecName codecName) { + this.pages = pages; + this.dictionary = dictionary; + this.columnDesc = columnDesc; + this.valueCount = valueCount; + this.codecName = codecName; + } + + @Override + public long getValueCount() { + return valueCount; + } + + @Override + public CompressionCodecName getCompression() { + return codecName; + } + + @Override + public ColumnDescriptor getColumnDesc() { + return columnDesc; + } + + @Override + public void writeDataPagesTo(ParquetFileWriter writer) { + pages.forEach(page -> writePageTo(page, writer)); + } + + @Override + public void writeDictionaryPageTo(ParquetFileWriter writer) throws IOException { + if (dictionary != null) { + writer.writeDictionaryPage(dictionary); + } + } + } + + private class MutableMergedColumn implements MergedColumn { + + private final List<DataPage> pages = new ArrayList<>(); + private final ColumnDescriptor columnDesc; + private final ValuesWriter newValuesWriter; + private final BiConsumer<ValuesReader, ValuesWriter> dataWriter; + private final Consumer<Long> compressedSizeAccumulator; + + private long valueCount; + + private MutableMergedColumn(ColumnDescriptor column, Consumer<Long> compressedSizeAccumulator) { + this.columnDesc = column; + this.compressedSizeAccumulator = compressedSizeAccumulator; + this.newValuesWriter = parquetProperties.newValuesWriter(columnDesc); + this.dataWriter = createWritingBridge(columnDesc.getPrimitiveType().getPrimitiveTypeName()); + } + + @Override + public long getValueCount() { + return valueCount; + } + + @Override + public CompressionCodecName getCompression() { + return compressor.getCodecName(); + } + + @Override + public ColumnDescriptor getColumnDesc() { + return columnDesc; + } + + @Override + public void writeDataPagesTo(ParquetFileWriter writer) { + pages.forEach(page -> writePageTo(page, writer)); + } + + @Override + public void writeDictionaryPageTo(ParquetFileWriter writer) throws IOException { + DictionaryPage page = newValuesWriter.toDictPageAndClose(); + if (page != null) { + writer.writeDictionaryPage(getCompressedDictionary(page, compressor)); + newValuesWriter.resetDictionary(); + } + } + + void addPage(DataPage data, Dictionary pageDictionary) { + DataPage recodePage = recodePage(data, pageDictionary); + compressedSizeAccumulator.accept((long) recodePage.getCompressedSize()); + valueCount += recodePage.getValueCount(); + pages.add(recodePage); + } + + DataPage recodePage(DataPage data, Dictionary pageDictionary) { Review comment: This is a pretty long method. Consider refactoring with some helper function. ---------------------------------------------------------------- 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
