Package org.apache.druid.query.aggregation

Interface VectorAggregator

All Known Implementing Classes:

CardinalityVectorAggregator, CountVectorAggregator, DoubleAnyVectorAggregator, DoubleFirstLastVectorAggregator, DoubleFirstVectorAggregator, DoubleLastVectorAggregator, DoubleMaxVectorAggregator, DoubleMeanVectorAggregator, DoubleMinVectorAggregator, DoubleSumVectorAggregator, FilteredVectorAggregator, FirstLastVectorAggregator, FloatAnyVectorAggregator, FloatFirstLastVectorAggregator, FloatFirstVectorAggregator, FloatLastVectorAggregator, FloatMaxVectorAggregator, FloatMinVectorAggregator, FloatSumVectorAggregator, HyperUniquesVectorAggregator, LongAnyVectorAggregator, LongConstantVectorAggregator, LongFirstLastVectorAggregator, LongFirstVectorAggregator, LongLastVectorAggregator, LongMaxVectorAggregator, LongMinVectorAggregator, LongSumVectorAggregator, NilVectorAggregator, NoopVectorAggregator, NullableNumericVectorAggregator, NumericAnyVectorAggregator, SingleStringFirstDimensionVectorAggregator, SingleStringFirstLastDimensionVectorAggregator, SingleStringLastDimensionVectorAggregator, StringAnyVectorAggregator, StringFirstLastVectorAggregator, StringFirstVectorAggregator, StringLastVectorAggregator, SuppressedAggregatorFactory.SuppressedVectorAggregator

public interface VectorAggregator

An object that can aggregate metrics into a ByteBuffer, from vectorized column selectors. Its aggregation-related methods (namely, "aggregate" and "get") do not take the actual input values to aggregate, because it is assumed that the VectorAggregator was given something that it can use to get at the current batch of data. None of the methods in this class are annotated with CalledFromHotLoop because vectorized query engines do not use monomorphic-processing-style specialization. Unlike Aggregator, VectorAggregators are never used by multiple threads at once. Implementations are not required to be thread safe.

Method Summary

Modifier and Type	Method	Description
void	aggregate(ByteBuffer buf, int numRows, int[] positions, int[] rows, int positionOffset)	Aggregate a list of rows ("rows") into a list of aggregation slots ("positions").
void	aggregate(ByteBuffer buf, int position, int startRow, int endRow)	Aggregate a range of rows into a single aggregation slot.
void	close()	Release any resources used by the aggregator.
Object	get(ByteBuffer buf, int position)	Same as BufferAggregator.get(java.nio.ByteBuffer, int).
void	init(ByteBuffer buf, int position)	Same as BufferAggregator.init(java.nio.ByteBuffer, int).
default void	relocate(int oldPosition, int newPosition, ByteBuffer oldBuffer, ByteBuffer newBuffer)	Same as BufferAggregator.relocate(int, int, java.nio.ByteBuffer, java.nio.ByteBuffer).

Method Detail

init

void init(ByteBuffer buf,
          int position)

Same as BufferAggregator.init(java.nio.ByteBuffer, int).

aggregate

void aggregate(ByteBuffer buf,
               int position,
               int startRow,
               int endRow)

Aggregate a range of rows into a single aggregation slot. Implementations must not change the position, limit or mark of the given buffer

Parameters:

buf - byte buffer storing the byte array representation of the aggregate

position - offset within the byte buffer at which the current aggregate value is stored

startRow - first row of the range within the current batch to aggregate (inclusive)

endRow - end row of the range (exclusive)

aggregate

void aggregate(ByteBuffer buf,
               int numRows,
               int[] positions,
               @Nullable
               int[] rows,
               int positionOffset)

Aggregate a list of rows ("rows") into a list of aggregation slots ("positions"). Implementations must not change the position, limit or mark of the given buffer

Parameters:

buf - byte buffer storing the byte array representation of the aggregate

numRows - number of rows to aggregate

positions - array of aggregate value positions within the buffer; must be at least as long as "numRows"

rows - array of row numbers within the current row batch; must be at least as long as "numRows". If null, the aggregator will aggregate rows from 0 (inclusive) to numRows (exclusive).

positionOffset - an offset to apply to each value from "positions"

get

@Nullable
Object get(ByteBuffer buf,
           int position)

Same as BufferAggregator.get(java.nio.ByteBuffer, int).

relocate

default void relocate(int oldPosition,
                      int newPosition,
                      ByteBuffer oldBuffer,
                      ByteBuffer newBuffer)

Same as BufferAggregator.relocate(int, int, java.nio.ByteBuffer, java.nio.ByteBuffer).

close

void close()

Release any resources used by the aggregator. The aggregator may be reused after this call, by calling init(ByteBuffer, int) followed by other methods as normal. This call would be more properly named "reset", but we use the name "close" to improve compatibility with existing aggregator implementations in extensions.