Java tutorial
/* * Licensed 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 com.facebook.presto.orc.writer; import com.facebook.presto.orc.checkpoint.BooleanStreamCheckpoint; import com.facebook.presto.orc.checkpoint.DecimalStreamCheckpoint; import com.facebook.presto.orc.checkpoint.LongStreamCheckpoint; import com.facebook.presto.orc.metadata.ColumnEncoding; import com.facebook.presto.orc.metadata.CompressionKind; import com.facebook.presto.orc.metadata.MetadataWriter; import com.facebook.presto.orc.metadata.RowGroupIndex; import com.facebook.presto.orc.metadata.Stream; import com.facebook.presto.orc.metadata.Stream.StreamKind; import com.facebook.presto.orc.metadata.statistics.ColumnStatistics; import com.facebook.presto.orc.metadata.statistics.LongDecimalStatisticsBuilder; import com.facebook.presto.orc.metadata.statistics.ShortDecimalStatisticsBuilder; import com.facebook.presto.orc.stream.DecimalOutputStream; import com.facebook.presto.orc.stream.LongOutputStream; import com.facebook.presto.orc.stream.LongOutputStreamV2; import com.facebook.presto.orc.stream.PresentOutputStream; import com.facebook.presto.spi.block.Block; import com.facebook.presto.spi.type.DecimalType; import com.facebook.presto.spi.type.Decimals; import com.facebook.presto.spi.type.Type; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableMap; import io.airlift.slice.Slice; import io.airlift.slice.SliceOutput; import org.openjdk.jol.info.ClassLayout; import java.io.IOException; import java.math.BigDecimal; import java.util.ArrayList; import java.util.List; import java.util.Map; import java.util.Optional; import static com.facebook.presto.orc.metadata.ColumnEncoding.ColumnEncodingKind.DIRECT_V2; import static com.facebook.presto.orc.metadata.CompressionKind.NONE; import static com.facebook.presto.orc.metadata.Stream.StreamKind.SECONDARY; import static com.google.common.base.Preconditions.checkArgument; import static com.google.common.base.Preconditions.checkState; import static java.util.Objects.requireNonNull; public class DecimalColumnWriter implements ColumnWriter { private static final int INSTANCE_SIZE = ClassLayout.parseClass(DecimalColumnWriter.class).instanceSize(); private final int column; private final DecimalType type; private final ColumnEncoding columnEncoding; private final boolean compressed; private final DecimalOutputStream dataStream; private final LongOutputStream scaleStream; private final PresentOutputStream presentStream; private final List<ColumnStatistics> rowGroupColumnStatistics = new ArrayList<>(); private ShortDecimalStatisticsBuilder shortDecimalStatisticsBuilder; private LongDecimalStatisticsBuilder longDecimalStatisticsBuilder; private boolean closed; public DecimalColumnWriter(int column, Type type, CompressionKind compression, int bufferSize, boolean isDwrf) { checkArgument(column >= 0, "column is negative"); checkArgument(!isDwrf, "DWRF does not support %s type", type); this.column = column; this.type = (DecimalType) requireNonNull(type, "type is null"); this.compressed = requireNonNull(compression, "compression is null") != NONE; this.columnEncoding = new ColumnEncoding(DIRECT_V2, 0); this.dataStream = new DecimalOutputStream(compression, bufferSize); this.scaleStream = new LongOutputStreamV2(compression, bufferSize, true, SECONDARY); this.presentStream = new PresentOutputStream(compression, bufferSize); if (this.type.isShort()) { shortDecimalStatisticsBuilder = new ShortDecimalStatisticsBuilder(this.type.getScale()); } else { longDecimalStatisticsBuilder = new LongDecimalStatisticsBuilder(); } } @Override public Map<Integer, ColumnEncoding> getColumnEncodings() { return ImmutableMap.of(column, columnEncoding); } @Override public void beginRowGroup() { presentStream.recordCheckpoint(); dataStream.recordCheckpoint(); scaleStream.recordCheckpoint(); } @Override public void writeBlock(Block block) { checkState(!closed); checkArgument(block.getPositionCount() > 0, "Block is empty"); // record nulls for (int position = 0; position < block.getPositionCount(); position++) { presentStream.writeBoolean(!block.isNull(position)); } // record values if (type.isShort()) { for (int position = 0; position < block.getPositionCount(); position++) { if (!block.isNull(position)) { long value = type.getLong(block, position); dataStream.writeUnscaledValue(value); shortDecimalStatisticsBuilder.addValue(value); } } } else { for (int position = 0; position < block.getPositionCount(); position++) { if (!block.isNull(position)) { Slice value = type.getSlice(block, position); dataStream.writeUnscaledValue(value); longDecimalStatisticsBuilder .addValue(new BigDecimal(Decimals.decodeUnscaledValue(value), type.getScale())); } } } for (int position = 0; position < block.getPositionCount(); position++) { if (!block.isNull(position)) { scaleStream.writeLong(type.getScale()); } } } @Override public Map<Integer, ColumnStatistics> finishRowGroup() { checkState(!closed); ColumnStatistics statistics; if (type.isShort()) { statistics = shortDecimalStatisticsBuilder.buildColumnStatistics(); shortDecimalStatisticsBuilder = new ShortDecimalStatisticsBuilder(type.getScale()); } else { statistics = longDecimalStatisticsBuilder.buildColumnStatistics(); longDecimalStatisticsBuilder = new LongDecimalStatisticsBuilder(); } rowGroupColumnStatistics.add(statistics); return ImmutableMap.of(column, statistics); } @Override public void close() { closed = true; dataStream.close(); scaleStream.close(); presentStream.close(); } @Override public Map<Integer, ColumnStatistics> getColumnStripeStatistics() { checkState(closed); return ImmutableMap.of(column, ColumnStatistics.mergeColumnStatistics(rowGroupColumnStatistics)); } @Override public List<Stream> writeIndexStreams(SliceOutput outputStream, MetadataWriter metadataWriter) throws IOException { checkState(closed); ImmutableList.Builder<RowGroupIndex> rowGroupIndexes = ImmutableList.builder(); List<DecimalStreamCheckpoint> dataCheckpoints = dataStream.getCheckpoints(); List<LongStreamCheckpoint> scaleCheckpoints = scaleStream.getCheckpoints(); Optional<List<BooleanStreamCheckpoint>> presentCheckpoints = presentStream.getCheckpoints(); for (int i = 0; i < rowGroupColumnStatistics.size(); i++) { int groupId = i; ColumnStatistics columnStatistics = rowGroupColumnStatistics.get(groupId); DecimalStreamCheckpoint dataCheckpoint = dataCheckpoints.get(groupId); LongStreamCheckpoint scaleCheckpoint = scaleCheckpoints.get(groupId); Optional<BooleanStreamCheckpoint> presentCheckpoint = presentCheckpoints .map(checkpoints -> checkpoints.get(groupId)); List<Integer> positions = createDecimalColumnPositionList(compressed, dataCheckpoint, scaleCheckpoint, presentCheckpoint); rowGroupIndexes.add(new RowGroupIndex(positions, columnStatistics)); } int length = metadataWriter.writeRowIndexes(outputStream, rowGroupIndexes.build()); return ImmutableList.of(new Stream(column, StreamKind.ROW_INDEX, length, false)); } private static List<Integer> createDecimalColumnPositionList(boolean compressed, DecimalStreamCheckpoint dataCheckpoint, LongStreamCheckpoint scaleCheckpoint, Optional<BooleanStreamCheckpoint> presentCheckpoint) { ImmutableList.Builder<Integer> positionList = ImmutableList.builder(); presentCheckpoint.ifPresent( booleanStreamCheckpoint -> positionList.addAll(booleanStreamCheckpoint.toPositionList(compressed))); positionList.addAll(dataCheckpoint.toPositionList(compressed)); positionList.addAll(scaleCheckpoint.toPositionList(compressed)); return positionList.build(); } @Override public List<Stream> writeDataStreams(SliceOutput outputStream) throws IOException { checkState(closed); ImmutableList.Builder<Stream> dataStreams = ImmutableList.builder(); presentStream.writeDataStreams(column, outputStream).ifPresent(dataStreams::add); dataStream.writeDataStreams(column, outputStream).ifPresent(dataStreams::add); scaleStream.writeDataStreams(column, outputStream).ifPresent(dataStreams::add); return dataStreams.build(); } @Override public long getBufferedBytes() { return dataStream.getBufferedBytes() + scaleStream.getBufferedBytes() + presentStream.getBufferedBytes(); } @Override public long getRetainedBytes() { // NOTE: we do not include stats because they should be small and it would be annoying to calculate the size return INSTANCE_SIZE + dataStream.getRetainedBytes() + scaleStream.getRetainedBytes() + presentStream.getRetainedBytes(); } @Override public void reset() { closed = false; dataStream.reset(); scaleStream.reset(); presentStream.reset(); rowGroupColumnStatistics.clear(); shortDecimalStatisticsBuilder = new ShortDecimalStatisticsBuilder(this.type.getScale()); longDecimalStatisticsBuilder = new LongDecimalStatisticsBuilder(); } }