sreemanamala commented on code in PR #16885: URL: https://github.com/apache/druid/pull/16885#discussion_r1734025354
########## processing/src/main/java/org/apache/druid/frame/read/columnar/StringArrayFrameColumnReader.java: ########## @@ -0,0 +1,386 @@ +/* + * 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.druid.frame.read.columnar; + +import com.google.common.annotations.VisibleForTesting; +import com.google.common.primitives.Ints; +import it.unimi.dsi.fastutil.objects.ObjectArrays; +import org.apache.datasketches.memory.Memory; +import org.apache.druid.common.config.NullHandling; +import org.apache.druid.error.DruidException; +import org.apache.druid.frame.Frame; +import org.apache.druid.frame.read.FrameReaderUtils; +import org.apache.druid.frame.write.FrameWriterUtils; +import org.apache.druid.frame.write.columnar.FrameColumnWriters; +import org.apache.druid.frame.write.columnar.StringFrameColumnWriter; +import org.apache.druid.java.util.common.StringUtils; +import org.apache.druid.query.monomorphicprocessing.RuntimeShapeInspector; +import org.apache.druid.query.rowsandcols.column.Column; +import org.apache.druid.query.rowsandcols.column.ColumnAccessorBasedColumn; +import org.apache.druid.query.rowsandcols.column.accessor.ObjectColumnAccessorBase; +import org.apache.druid.segment.ColumnValueSelector; +import org.apache.druid.segment.ObjectColumnSelector; +import org.apache.druid.segment.column.BaseColumn; +import org.apache.druid.segment.column.ColumnCapabilitiesImpl; +import org.apache.druid.segment.column.ColumnType; +import org.apache.druid.segment.data.ReadableOffset; +import org.apache.druid.segment.vector.ReadableVectorInspector; +import org.apache.druid.segment.vector.ReadableVectorOffset; +import org.apache.druid.segment.vector.VectorObjectSelector; + +import javax.annotation.Nullable; +import java.nio.ByteBuffer; +import java.util.Comparator; + +/** + * Reader for {@link ColumnType#STRING_ARRAY}. + */ +public class StringArrayFrameColumnReader implements FrameColumnReader +{ + private final int columnNumber; + + /** + * Create a new reader. + * + * @param columnNumber column number + */ + StringArrayFrameColumnReader(int columnNumber) + { + this.columnNumber = columnNumber; + } + + @Override + public Column readRACColumn(Frame frame) + { + final Memory memory = frame.region(columnNumber); + validate(memory); + + final long positionOfLengths = getStartOfStringLengthSection(frame.numRows()); + final long positionOfPayloads = getStartOfStringDataSection(memory, frame.numRows()); + + StringArrayFrameColumn frameCol = new StringArrayFrameColumn( + frame, + memory, + positionOfLengths, + positionOfPayloads + ); + + return new ColumnAccessorBasedColumn(frameCol); + } + + @Override + public ColumnPlus readColumn(final Frame frame) + { + final Memory memory = frame.region(columnNumber); + validate(memory); + + final long startOfStringLengthSection = getStartOfStringLengthSection(frame.numRows()); + final long startOfStringDataSection = getStartOfStringDataSection(memory, frame.numRows()); + + final BaseColumn baseColumn = new StringArrayFrameColumn( + frame, + memory, + startOfStringLengthSection, + startOfStringDataSection + ); + + return new ColumnPlus( + baseColumn, + new ColumnCapabilitiesImpl().setType(ColumnType.STRING_ARRAY) + .setHasMultipleValues(false) + .setDictionaryEncoded(false), + frame.numRows() + ); + } + + private void validate(final Memory region) + { + // Check if column is big enough for a header + if (region.getCapacity() < StringFrameColumnWriter.DATA_OFFSET) { + throw DruidException.defensive("Column[%s] is not big enough for a header", columnNumber); + } + + final byte typeCode = region.getByte(0); + if (typeCode != FrameColumnWriters.TYPE_STRING_ARRAY) { + throw DruidException.defensive( + "Column[%s] does not have the correct type code; expected[%s], got[%s]", + columnNumber, + FrameColumnWriters.TYPE_STRING_ARRAY, + typeCode + ); + } + } + + private static long getStartOfCumulativeLengthSection() + { + return StringFrameColumnWriter.DATA_OFFSET; + } + + private static long getStartOfStringLengthSection(final int numRows) + { + return StringFrameColumnWriter.DATA_OFFSET + (long) Integer.BYTES * numRows; + } + + private long getStartOfStringDataSection( + final Memory memory, + final int numRows + ) + { + if (numRows < 0) { + throw DruidException.defensive("Encountered -ve numRows [%s] while reading frame", numRows); + } + final int totalNumValues = FrameColumnReaderUtils.getAdjustedCumulativeRowLength( + memory, + getStartOfCumulativeLengthSection(), + numRows - 1 + ); + + return getStartOfStringLengthSection(numRows) + (long) Integer.BYTES * totalNumValues; + } + + @VisibleForTesting + private static class StringArrayFrameColumn extends ObjectColumnAccessorBase implements BaseColumn + { + private final Frame frame; + private final Memory memory; + private final long startOfStringLengthSection; + private final long startOfStringDataSection; + + private StringArrayFrameColumn( + Frame frame, + Memory memory, + long startOfStringLengthSection, + long startOfStringDataSection + ) + { + this.frame = frame; + this.memory = memory; + this.startOfStringLengthSection = startOfStringLengthSection; + this.startOfStringDataSection = startOfStringDataSection; + } + + @Override + public ColumnValueSelector<?> makeColumnValueSelector(ReadableOffset offset) + { + return new ObjectColumnSelector<Object>() + { + @Override + public void inspectRuntimeShape(RuntimeShapeInspector inspector) + { + // Do nothing. + } + + @Nullable + @Override + public Object getObject() + { + return getRowAsObject(frame.physicalRow(offset.getOffset()), true); + } + + @Override + public Class<?> classOfObject() + { + return String[].class; Review Comment: This method was not being invoked. The operations were using the `columnType` of the selector. Anyways will make it `Object[]` to be consistent -- 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]
