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.

Parameter field provided in the constructor is used as a field name in the default implementations of the methods getNumericDocValues and getPointValues to retrieve doc values and points. You can pass a dummy value for a field name (e.g. when sorting by script), but in this case you must override both of these methods.

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.TermValComparator

Field Summary

Fields

Modifier and Type	Field	Description
protected String	field
protected boolean	hitsThresholdReached
protected T	missingValue
protected Pruning	pruning
protected boolean	queueFull
protected boolean	reverse
protected boolean	singleSort
protected boolean	topValueSet

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	NumericComparator(String field, T missingValue, boolean reverse, Pruning pruning, 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 Detail

missingValue

protected final T extends Number missingValue

field

protected final String field

reverse

protected final boolean reverse

topValueSet

protected boolean topValueSet

singleSort

protected boolean singleSort

hitsThresholdReached

protected boolean hitsThresholdReached

queueFull

protected boolean queueFull

pruning

protected Pruning pruning

Constructor Detail

NumericComparator

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

Method Detail

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>

disableSkipping

public void disableSkipping()

Description copied from class: FieldComparator

Informs the comparator that the skipping of documents should be disabled. This function is called by TopFieldCollector in cases when the skipping functionality should not be applied or not necessary. An 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>