Package org.apache.druid.query.aggregation

Class NullableNumericVectorAggregator

java.lang.Object

org.apache.druid.query.aggregation.NullableNumericVectorAggregator

All Implemented Interfaces:

VectorAggregator

public class NullableNumericVectorAggregator
extends Object
implements VectorAggregator

A wrapper around a non-null-aware VectorAggregator that makes it null-aware. This removes the need for each aggregator class to handle nulls on its own. This class only makes sense as a wrapper for "primitive" aggregators, i.e., ones that take VectorValueSelector as input. The result of this aggregator will be null if all the values to be aggregated are null values or no values are aggregated at all. If any of the values are non-null, the result will be the aggregated value of the delegate aggregator. When wrapped by this class, the underlying aggregator's required storage space is increased by one byte. The extra byte is a boolean that stores whether or not any non-null values have been seen. The extra byte is placed before the underlying aggregator's normal state. (Buffer layout = [nullability byte] [delegate storage bytes]) The result of a NullableAggregator will be null if all the values to be aggregated are null values or no values are aggregated at all. If any of the value is non-null, the result would be the aggregated value of the delegate aggregator. Note that the delegate aggregator is not required to perform check for VectorValueSelector.getNullVector() on the selector as only non-null values will be passed to the delegate aggregator. This class is only used when SQL compatible null handling is enabled.

See Also:

, the vectorized version.

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).
void	relocate(int oldPosition, int newPosition, ByteBuffer oldBuffer, ByteBuffer newBuffer)	Same as BufferAggregator.relocate(int, int, java.nio.ByteBuffer, java.nio.ByteBuffer).

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

init

public void init(ByteBuffer buf,
                 int position)

Description copied from interface: VectorAggregator

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

Specified by:

init in interface VectorAggregator

aggregate

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

Description copied from interface: VectorAggregator

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

Specified by:

aggregate in interface VectorAggregator

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

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

Description copied from interface: VectorAggregator

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

Specified by:

aggregate in interface VectorAggregator

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
public Object get(ByteBuffer buf,
                  int position)

Description copied from interface: VectorAggregator

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

Specified by:

get in interface VectorAggregator

relocate

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

Description copied from interface: VectorAggregator

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

Specified by:

relocate in interface VectorAggregator

close

public void close()

Description copied from interface: VectorAggregator

Release any resources used by the aggregator. The aggregator may be reused after this call, by calling VectorAggregator.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.

Specified by:

close in interface VectorAggregator