somu-imply commented on code in PR #14911: URL: https://github.com/apache/druid/pull/14911#discussion_r1307705960
########## processing/src/main/java/org/apache/druid/query/aggregation/last/SingleStringLastDimensionVectorAggregator.java: ########## @@ -0,0 +1,124 @@ +/* + * 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.query.aggregation.last; + +import org.apache.druid.common.config.NullHandling; +import org.apache.druid.java.util.common.StringUtils; +import org.apache.druid.query.aggregation.SerializablePairLongString; +import org.apache.druid.query.aggregation.VectorAggregator; +import org.apache.druid.segment.vector.SingleValueDimensionVectorSelector; +import org.apache.druid.segment.vector.VectorValueSelector; + +import javax.annotation.Nullable; +import java.nio.ByteBuffer; + +public class SingleStringLastDimensionVectorAggregator implements VectorAggregator +{ + private final VectorValueSelector timeSelector; + private final SingleValueDimensionVectorSelector valueDimensionVectorSelector; + private long lastTime; + private final int maxStringBytes; + private final boolean useDefault = NullHandling.replaceWithDefault(); + + public SingleStringLastDimensionVectorAggregator( + VectorValueSelector timeSelector, + SingleValueDimensionVectorSelector valueDimensionVectorSelector, + int maxStringBytes + ) + { + this.timeSelector = timeSelector; + this.valueDimensionVectorSelector = valueDimensionVectorSelector; + this.maxStringBytes = maxStringBytes; + this.lastTime = Long.MIN_VALUE; + } + + @Override + public void init(ByteBuffer buf, int position) + { + buf.putLong(position, Long.MIN_VALUE); + buf.put( + position + NumericLastVectorAggregator.NULL_OFFSET, + useDefault ? NullHandling.IS_NOT_NULL_BYTE : NullHandling.IS_NULL_BYTE + ); + buf.putLong(position + NumericLastVectorAggregator.VALUE_OFFSET, 0); + } + + @Override + public void aggregate(ByteBuffer buf, int position, int startRow, int endRow) + { + final long[] timeVector = timeSelector.getLongVector(); + final boolean[] nullTimeVector = timeSelector.getNullVector(); + final int[] valueVector = valueDimensionVectorSelector.getRowVector(); + lastTime = buf.getLong(position); + int index; + + long latestTime; + for (index = endRow - 1; index >= startRow; index--) { + if (nullTimeVector != null && nullTimeVector[index]) { + continue; + } + latestTime = timeVector[index]; + if (latestTime > lastTime) { + lastTime = latestTime; + buf.putLong(position, lastTime); + buf.put(position + NumericLastVectorAggregator.NULL_OFFSET, NullHandling.IS_NOT_NULL_BYTE); + buf.putInt(position + NumericLastVectorAggregator.VALUE_OFFSET, valueVector[index]); + } + } + } + + @Override + public void aggregate(ByteBuffer buf, int numRows, int[] positions, @Nullable int[] rows, int positionOffset) + { + final long[] timeVector = timeSelector.getLongVector(); + final boolean[] nullTimeVector = timeSelector.getNullVector(); + final int[] values = valueDimensionVectorSelector.getRowVector(); + for (int i = numRows - 1; i >= 0; i--) { + if (nullTimeVector != null && nullTimeVector[i]) { + continue; + } + int position = positions[i] + positionOffset; + int row = rows == null ? i : rows[i]; + lastTime = buf.getLong(position); + if (timeVector[row] > lastTime) { + lastTime = timeVector[row]; + buf.putLong(position, lastTime); + buf.put(position + NumericLastVectorAggregator.NULL_OFFSET, NullHandling.IS_NOT_NULL_BYTE); + buf.putInt(position + NumericLastVectorAggregator.VALUE_OFFSET, values[row]); + } + } + } + + @Nullable + @Override + public Object get(ByteBuffer buf, int position) + { + int index = buf.getInt(position + NumericLastVectorAggregator.VALUE_OFFSET); + long earliest = buf.getLong(position); + String strValue = valueDimensionVectorSelector.lookupName(index); + return new SerializablePairLongString(earliest, StringUtils.chop(strValue, maxStringBytes)); Review Comment: Strings longer than maxStringBytes are truncated as per the value. This is documented in https://druid.apache.org/docs/latest/querying/sql-aggregations -- 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]
