Package org.apache.lucene.search

Class MultiLeafFieldComparator

java.lang.Object

org.apache.lucene.search.MultiLeafFieldComparator

All Implemented Interfaces:

LeafFieldComparator

final class MultiLeafFieldComparator
extends java.lang.Object
implements LeafFieldComparator

Field Summary

Fields

Modifier and Type	Field	Description
private LeafFieldComparator[]	comparators
private LeafFieldComparator	firstComparator
private int	firstReverseMul
private int[]	reverseMul

Constructor Summary

Constructors

Constructor	Description
MultiLeafFieldComparator(LeafFieldComparator[] comparators, int[] reverseMul)

Method Summary

Modifier and Type	Method	Description
int	compareBottom(int doc)	Compare the bottom of the queue with this doc.
int	compareTop(int doc)	Compare the top value with this doc.
DocIdSetIterator	competitiveIterator()	Returns a competitive iterator
void	copy(int slot, int doc)	This method is called when a new hit is competitive.
void	setBottom(int slot)	Set the bottom slot, ie the "weakest" (sorted last) entry in the queue.
void	setHitsThresholdReached()	Informs this leaf comparator that hits threshold is reached.
void	setScorer(Scorable scorer)	Sets the Scorer to use in case a document's score is needed.

Methods inherited from class java.lang.Object

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

Field Detail

comparators

private final LeafFieldComparator[] comparators

reverseMul

private final int[] reverseMul

firstComparator

private final LeafFieldComparator firstComparator

firstReverseMul

private final int firstReverseMul

Constructor Detail

MultiLeafFieldComparator

MultiLeafFieldComparator(LeafFieldComparator[] comparators,
                         int[] reverseMul)

Method Detail

setBottom

public void setBottom(int slot)
               throws java.io.IOException

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

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

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

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

setScorer

public void setScorer(Scorable scorer)
               throws java.io.IOException

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.

Throws:

java.io.IOException

setHitsThresholdReached

public void setHitsThresholdReached()
                             throws java.io.IOException

Description copied from interface: LeafFieldComparator

Informs this leaf comparator that hits threshold is reached. This method is called from a collector when hits threshold is reached.

Specified by:

setHitsThresholdReached in interface LeafFieldComparator

Throws:

java.io.IOException

competitiveIterator

public DocIdSetIterator competitiveIterator()
                                     throws java.io.IOException

Description copied from interface: LeafFieldComparator

Returns a competitive iterator

Specified by:

competitiveIterator in interface LeafFieldComparator

Returns:

an iterator over competitive docs that are stronger than already collected docs or null if such an iterator is not available for the current comparator or segment.

Throws:

java.io.IOException