org.apache.arrow.algorithm.sort

Class StableVectorComparator<V extends ValueVector>

java.lang.Object

org.apache.arrow.algorithm.sort.VectorValueComparator<V>

org.apache.arrow.algorithm.sort.StableVectorComparator<V>

Type Parameters:

V - type of the vector.

public class StableVectorComparator<V extends ValueVector>
extends VectorValueComparator<V>

Stable sorter. It compares values like ordinary comparators. However, when values are equal, it breaks ties by the value indices. Therefore, sort algorithms using this comparator always produce stable sort results.

Field Summary

Fields inherited from class org.apache.arrow.algorithm.sort.VectorValueComparator

valueWidth, vector1, vector2

Constructor Summary

Constructors

Constructor and Description
StableVectorComparator(VectorValueComparator<V> innerComparator) Constructs a stable comparator from a given comparator.

Method Summary

Modifier and Type	Method and Description
void	attachVector(V vector) Attach both vectors to compare to the same input vector.
void	attachVectors(V vector1, V vector2) Attach vectors to compare.
int	compareNotNull(int index1, int index2) Compare two values, given their indices.
VectorValueComparator<V>	createNew() Creates a comparator of the same type.

Methods inherited from class org.apache.arrow.algorithm.sort.VectorValueComparator

checkNullsOnCompare, compare, getValueWidth

Methods inherited from class java.lang.Object

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

Constructor Detail

StableVectorComparator

public StableVectorComparator(VectorValueComparator<V> innerComparator)

Constructs a stable comparator from a given comparator.

Parameters:

innerComparator - the comparator to convert to stable comparator..

Method Detail

attachVector

public void attachVector(V vector)

Description copied from class: VectorValueComparator

Attach both vectors to compare to the same input vector.

Overrides:

attachVector in class VectorValueComparator<V extends ValueVector>

Parameters:

vector - the vector to attach.

attachVectors

public void attachVectors(V vector1,
                          V vector2)

Description copied from class: VectorValueComparator

Attach vectors to compare.

Overrides:

attachVectors in class VectorValueComparator<V extends ValueVector>

Parameters:

vector1 - the first vector to compare.

vector2 - the second vector to compare.

compareNotNull

public int compareNotNull(int index1,
                          int index2)

Description copied from class: VectorValueComparator

Compare two values, given their indices. This is a fast path for comparing non-null values, so the caller must make sure that values at both indices are not null.

Specified by:

compareNotNull in class VectorValueComparator<V extends ValueVector>

Parameters:

index1 - index of the first value to compare.

index2 - index of the second value to compare.

Returns:

an integer greater than 0, if the first value is greater; an integer smaller than 0, if the first value is smaller; or 0, if both values are equal.

createNew

public VectorValueComparator<V> createNew()

Description copied from class: VectorValueComparator

Creates a comparator of the same type.

Specified by:

createNew in class VectorValueComparator<V extends ValueVector>

Returns:

the newly created comparator.