org.apache.lucene.document

Class LatLonPointDistanceComparator

java.lang.Object

org.apache.lucene.search.FieldComparator<java.lang.Double>

org.apache.lucene.document.LatLonPointDistanceComparator

All Implemented Interfaces:

LeafFieldComparator

class LatLonPointDistanceComparator
extends FieldComparator<java.lang.Double>
implements LeafFieldComparator

Compares documents by distance from an origin point

When the least competitive item on the priority queue changes (setBottom), we recompute a bounding box representing competitive distance to the top-N. Then in compareBottom, we can quickly reject hits based on bounding box alone without computing distance for every element.

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 java.lang.Number>, FieldComparator.RelevanceComparator, FieldComparator.TermOrdValComparator, FieldComparator.TermValComparator

Field Summary

Fields

Modifier and Type	Field and Description
(package private) double	bottom
(package private) SortedNumericDocValues	currentDocs
private long[]	currentValues
(package private) java.lang.String	field
(package private) double	latitude
(package private) double	longitude
(package private) int	maxLat
(package private) int	maxLon
(package private) int	minLat
(package private) int	minLon
(package private) int	minLon2
(package private) int	setBottomCounter
(package private) double	topValue
(package private) double[]	values
private int	valuesDocID

Constructor Summary

Constructors

Constructor and Description
LatLonPointDistanceComparator(java.lang.String field, double latitude, double longitude, int numHits)

Method Summary

Modifier and Type	Method and 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.
LeafFieldComparator	getLeafComparator(LeafReaderContext context) Get a per-segment LeafFieldComparator to collect the given LeafReaderContext.
(package private) static double	haversin2(double partial)
void	setBottom(int slot) Set the bottom slot, ie the "weakest" (sorted last) entry in the queue.
void	setScorer(Scorable scorer) Sets the Scorer to use in case a document's score is needed.
void	setTopValue(java.lang.Double value) Record the top value, for future calls to LeafFieldComparator.compareTop(int).
private void	setValues()
(package private) double	sortKey(int doc)
java.lang.Double	value(int slot) Return the actual value in the slot.

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

Field Detail

field

final java.lang.String field

latitude

final double latitude

longitude

final double longitude

values

final double[] values

bottom

double bottom

topValue

double topValue

currentDocs

SortedNumericDocValues currentDocs

minLon

int minLon

maxLon

int maxLon

minLat

int minLat

maxLat

int maxLat

minLon2

int minLon2

setBottomCounter

int setBottomCounter

currentValues

private long[] currentValues

valuesDocID

private int valuesDocID

Constructor Detail

LatLonPointDistanceComparator

public LatLonPointDistanceComparator(java.lang.String field,
                                     double latitude,
                                     double longitude,
                                     int numHits)

Method Detail

setScorer

public void setScorer(Scorable scorer)

Description copied from interface: LeafFieldComparator

Sets the Scorer to use in case a document's score is needed.

Specified by:

setScorer in interface LeafFieldComparator

Parameters:

scorer - Scorer instance that you should use to obtain the current hit's score, if necessary.

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<java.lang.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

setBottom

public void setBottom(int slot)

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).

Specified by:

setBottom in interface LeafFieldComparator

Parameters:

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

setTopValue

public void setTopValue(java.lang.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<java.lang.Double>

setValues

private void setValues()
                throws java.io.IOException

Throws:

java.io.IOException

compareBottom

public int compareBottom(int doc)
                  throws java.io.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).

Specified by:

compareBottom in interface LeafFieldComparator

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:

java.io.IOException

copy

public void copy(int slot,
                 int doc)
          throws java.io.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.

Specified by:

copy in interface LeafFieldComparator

Parameters:

slot - which slot to copy the hit to

doc - docID relative to current reader

Throws:

java.io.IOException

getLeafComparator

public LeafFieldComparator getLeafComparator(LeafReaderContext context)
                                      throws java.io.IOException

Description copied from class: FieldComparator

Get a per-segment LeafFieldComparator to collect the given LeafReaderContext. All docIDs supplied to this LeafFieldComparator are relative to the current reader (you must add docBase if you need to map it to a top-level docID).

Specified by:

getLeafComparator in class FieldComparator<java.lang.Double>

Parameters:

context - current reader context

Returns:

the comparator to use for this segment

Throws:

java.io.IOException - if there is a low-level IO error

value

public java.lang.Double value(int slot)

Description copied from class: FieldComparator

Return the actual value in the slot.

Specified by:

value in class FieldComparator<java.lang.Double>

Parameters:

slot - the value

Returns:

value in this slot

compareTop

public int compareTop(int doc)
               throws java.io.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).

Specified by:

compareTop in interface LeafFieldComparator

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:

java.io.IOException

sortKey

double sortKey(int doc)
        throws java.io.IOException

Throws:

java.io.IOException

haversin2

static double haversin2(double partial)