Package org.apache.lucene.search

Class FieldComparator.DoubleComparator

java.lang.Object

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

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

org.apache.lucene.search.FieldComparator.NumericComparator<Double>

org.apache.lucene.search.FieldComparator.DoubleComparator

All Implemented Interfaces:

LeafFieldComparator

Enclosing class:

FieldComparator<T>

public static class FieldComparator.DoubleComparator
extends FieldComparator.NumericComparator<Double>

Parses field's values as double (using LeafReader.getNumericDocValues(java.lang.String) and sorts by ascending value

Nested Class Summary

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

FieldComparator.DocComparator, FieldComparator.DoubleComparator, FieldComparator.FloatComparator, FieldComparator.IntComparator, FieldComparator.LongComparator, FieldComparator.NumericComparator<T extends Number>, FieldComparator.RelevanceComparator, FieldComparator.TermOrdValComparator, FieldComparator.TermValComparator

Field Summary

Fields inherited from class org.apache.lucene.search.FieldComparator.NumericComparator

currentReaderValues, field, missingValue

Constructor Summary

Constructors

Constructor	Description
DoubleComparator(int numHits, String field, Double missingValue)	Creates a new comparator based on Double.compare(double, double) for numHits.

Method Summary

Modifier and Type	Method	Description
int	compare(int slot1, int slot2)	Compare hit at slot1 with hit at slot2.
int	compareBottom(int doc)	Compare the bottom of the queue with this doc.
int	compareTop(int doc)	Compare the top value with this doc.
void	copy(int slot, int doc)	This method is called when a new hit is competitive.
void	setBottom(int bottom)	Set the bottom slot, ie the "weakest" (sorted last) entry in the queue.
void	setTopValue(Double value)	Record the top value, for future calls to LeafFieldComparator.compareTop(int).
Double	value(int slot)	Return the actual value in the slot.

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

doSetNextReader, getNumericDocValues

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

getLeafComparator, setScorer

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

compareValues

Methods inherited from class java.lang.Object

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

Constructor Detail

DoubleComparator

public DoubleComparator(int numHits,
                        String field,
                        Double missingValue)

Creates a new comparator based on Double.compare(double, double) for numHits. When a document has no value for the field, missingValue is substituted.

Method Detail

compare

public int compare(int slot1,
                   int slot2)

Description copied from class: FieldComparator

Compare hit at slot1 with hit at slot2.

Specified by:

compare in class FieldComparator<Double>

Parameters:

slot1 - first slot to compare

slot2 - second slot to compare

Returns:

any N < 0 if slot2's value is sorted after slot1, any N > 0 if the slot2's value is sorted before slot1 and 0 if they are equal

compareBottom

public int compareBottom(int doc)
                  throws IOException

Description copied from interface: LeafFieldComparator

Compare the bottom of the queue with this doc. This will only invoked after setBottom has been called. This should return the same result as FieldComparator.compare(int,int)} as if bottom were slot1 and the new document were slot 2.

For a search that hits many results, this method will be the hotspot (invoked by far the most frequently).

Parameters:

doc - that was hit

Returns:

any N < 0 if the doc's value is sorted after the bottom entry (not competitive), any N > 0 if the doc's value is sorted before the bottom entry and 0 if they are equal.

Throws:

IOException

copy

public void copy(int slot,
                 int doc)
          throws IOException

Description copied from interface: LeafFieldComparator

This method is called when a new hit is competitive. You should copy any state associated with this document that will be required for future comparisons, into the specified slot.

Parameters:

slot - which slot to copy the hit to

doc - docID relative to current reader

Throws:

IOException

setBottom

public void setBottom(int bottom)

Description copied from interface: LeafFieldComparator

Set the bottom slot, ie the "weakest" (sorted last) entry in the queue. When LeafFieldComparator.compareBottom(int) is called, you should compare against this slot. This will always be called before LeafFieldComparator.compareBottom(int).

Parameters:

bottom - the currently weakest (sorted last) slot in the queue

setTopValue

public void setTopValue(Double 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<Double>

value

public Double value(int slot)

Description copied from class: FieldComparator

Return the actual value in the slot.

Specified by:

value in class FieldComparator<Double>

Parameters:

slot - the value

Returns:

value in this slot

compareTop

public int compareTop(int doc)
               throws IOException

Description copied from interface: LeafFieldComparator

Compare the top value with this doc. This will only invoked after setTopValue has been called. This should return the same result as FieldComparator.compare(int,int)} as if topValue were slot1 and the new document were slot 2. This is only called for searches that use searchAfter (deep paging).

Parameters:

doc - that was hit

Returns:

any N < 0 if the doc's value is sorted after the top entry (not competitive), any N > 0 if the doc's value is sorted before the top entry and 0 if they are equal.

Throws:

IOException