org.apache.arrow.algorithm.sort

Class VectorValueComparator<V extends ValueVector>

java.lang.Object

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

Type Parameters:

V - type of the vector.

Direct Known Subclasses:

CompositeVectorComparator, DefaultVectorComparators.ByteComparator, DefaultVectorComparators.Float4Comparator, DefaultVectorComparators.Float8Comparator, DefaultVectorComparators.IntComparator, DefaultVectorComparators.LongComparator, DefaultVectorComparators.RepeatedValueComparator, DefaultVectorComparators.ShortComparator, DefaultVectorComparators.UInt1Comparator, DefaultVectorComparators.UInt2Comparator, DefaultVectorComparators.UInt4Comparator, DefaultVectorComparators.UInt8Comparator, DefaultVectorComparators.VariableWidthComparator, StableVectorComparator

public abstract class VectorValueComparator<V extends ValueVector>
extends Object

Compare two values at the given indices in the vectors. This is used for vector sorting.

Field Summary

Fields

Modifier and Type	Field and Description
protected int	valueWidth Width of the vector value.
protected V	vector1 The first vector to compare.
protected V	vector2 The second vector to compare.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	VectorValueComparator() Constructor for variable-width vectors.
protected	VectorValueComparator(int valueWidth) Constructor for fixed-width vectors.

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.
boolean	checkNullsOnCompare() This value is true by default and re-computed when vectors are attached to the comparator.
int	compare(int index1, int index2) Compare two values, given their indices.
abstract int	compareNotNull(int index1, int index2) Compare two values, given their indices.
abstract VectorValueComparator<V>	createNew() Creates a comparator of the same type.
int	getValueWidth()

Methods inherited from class java.lang.Object

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

Field Detail

vector1

protected V extends ValueVector vector1

The first vector to compare.

vector2

protected V extends ValueVector vector2

The second vector to compare.

valueWidth

protected int valueWidth

Width of the vector value. For variable-length vectors, this value makes no sense.

Constructor Detail

VectorValueComparator

protected VectorValueComparator()

Constructor for variable-width vectors.

VectorValueComparator

protected VectorValueComparator(int valueWidth)

Constructor for fixed-width vectors.

Parameters:

valueWidth - the record width (in bytes).

Method Detail

checkNullsOnCompare

public boolean checkNullsOnCompare()

This value is true by default and re-computed when vectors are attached to the comparator. If both vectors cannot contain nulls then this value is false and calls to compare(i1, i2) are short-circuited to compareNotNull(i1, i2) thereby speeding up comparisons resulting in faster sorts etc.

getValueWidth

public int getValueWidth()

attachVector

public void attachVector(V vector)

Attach both vectors to compare to the same input vector.

Parameters:

vector - the vector to attach.

attachVectors

public void attachVectors(V vector1,
                          V vector2)

Attach vectors to compare.

Parameters:

vector1 - the first vector to compare.

vector2 - the second vector to compare.

compare

public int compare(int index1,
                   int index2)

Compare two values, given their indices.

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.

compareNotNull

public abstract int compareNotNull(int index1,
                                   int index2)

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.

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 abstract VectorValueComparator<V> createNew()

Creates a comparator of the same type.

Returns:

the newly created comparator.