Package org.apache.lucene.search.comparators

Class NumericComparator<T extends Number>

java.lang.Object

org.apache.lucene.search.FieldComparator<T>

org.apache.lucene.search.comparators.NumericComparator<T>

Direct Known Subclasses:

DoubleComparator, FloatComparator, IntComparator, LongComparator

public abstract class NumericComparator<T extends Number>
extends FieldComparator<T>

Abstract numeric comparator for comparing numeric values. This comparator provides a skipping functionality – an iterator that can skip over non-competitive documents.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
class	NumericComparator.NumericLeafComparator	Leaf comparator for NumericComparator that provides skipping functionality

Nested classes/interfaces inherited from class org.apache.lucene.search.FieldComparator

FieldComparator.RelevanceComparator, FieldComparator.TermOrdValComparator, FieldComparator.TermValComparator

Field Summary

Fields

Modifier and Type	Field	Description
private final int	bytesCount
private boolean	canSkipDocuments
protected final String	field
protected boolean	hitsThresholdReached
protected final T	missingValue
protected boolean	queueFull
protected final boolean	reverse
protected boolean	singleSort
protected boolean	topValueSet

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	NumericComparator(String field, T missingValue, boolean reverse, int sortPos, int bytesCount)

Method Summary

Modifier and Type	Method	Description
void	disableSkipping()	Informs the comparator that the skipping of documents should be disabled.
void	setSingleSort()	Informs the comparator that sort is done on this single field.
void	setTopValue(T value)	Record the top value, for future calls to LeafFieldComparator.compareTop(int).

Methods inherited from class org.apache.lucene.search.FieldComparator

compare, compareValues, getLeafComparator, value

Methods inherited from class java.lang.Object

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

Field Details

missingValue

protected final T extends Number missingValue

field

protected final String field

reverse

protected final boolean reverse

bytesCount

private final int bytesCount

topValueSet

protected boolean topValueSet

singleSort

protected boolean singleSort

hitsThresholdReached

protected boolean hitsThresholdReached

queueFull

protected boolean queueFull

canSkipDocuments

private boolean canSkipDocuments

Constructor Details

NumericComparator

protected NumericComparator(String field,
 T missingValue,
 boolean reverse,
 int sortPos,
 int bytesCount)

Method Details

disableSkipping

public void disableSkipping()

Description copied from class: FieldComparator

Informs the comparator that the skipping of documents should be disabled. This function is called in cases when the skipping functionality should not be applied or not necessary. One example for numeric comparators is when we don't know if the same numeric data has been indexed with docValues and points if these two fields have the same name. As the skipping functionality relies on these fields to have the same data and as we don't know if it is true, we have to disable it. Another example could be when search sort is a part of the index sort, and can be already efficiently handled by TopFieldCollector, and doing extra work for skipping in the comparator is redundant.

Overrides:

disableSkipping in class FieldComparator<T extends Number>

setTopValue

public void setTopValue(T value)

Description copied from class: FieldComparator

Record the top value, for future calls to LeafFieldComparator.compareTop(int). This is only called for searches that use searchAfter (deep paging), and is called before any calls to FieldComparator.getLeafComparator(LeafReaderContext).

Specified by:

setTopValue in class FieldComparator<T extends Number>

setSingleSort

public void setSingleSort()

Description copied from class: FieldComparator

Informs the comparator that sort is done on this single field. This is useful to enable some optimizations for skipping non-competitive documents.

Overrides:

setSingleSort in class FieldComparator<T extends Number>