Package org.apache.lucene.search.comparators

Class NumericComparator.NumericLeafComparator

java.lang.Object

org.apache.lucene.search.comparators.NumericComparator.NumericLeafComparator

All Implemented Interfaces:

LeafFieldComparator

Direct Known Subclasses:

DoubleComparator.DoubleLeafComparator, FloatComparator.FloatLeafComparator, IntComparator.IntLeafComparator, LongComparator.LongLeafComparator

Enclosing class:

NumericComparator<T extends Number>

public abstract class NumericComparator.NumericLeafComparator
extends Object
implements LeafFieldComparator

Leaf comparator for NumericComparator that provides skipping functionality

Field Summary

Fields

Modifier and Type	Field	Description
protected NumericDocValues	docValues

Constructor Summary

Constructors

Constructor	Description
NumericLeafComparator(LeafReaderContext context)

Method Summary

Modifier and Type	Method	Description
protected abstract int	compareMissingValueWithBottomValue()
protected abstract int	compareMissingValueWithTopValue()	in ascending sort, missing value is competitive when it is less or equal(maybe there are two or more comparators) than bottom value.
DocIdSetIterator	competitiveIterator()	Returns a competitive iterator
void	copy(int slot, int doc)	This method is called when a new hit is competitive.
protected abstract void	encodeBottom(byte[] packedValue)
protected abstract void	encodeTop(byte[] packedValue)
protected NumericDocValues	getNumericDocValues(LeafReaderContext context, String field)	Retrieves the NumericDocValues for the field in this segment
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

Methods inherited from interface org.apache.lucene.search.LeafFieldComparator

compareBottom, compareTop

Field Detail

docValues

protected final NumericDocValues docValues

Constructor Detail

NumericLeafComparator

public NumericLeafComparator(LeafReaderContext context)
                      throws IOException

Throws:

IOException

Method Detail

getNumericDocValues

protected NumericDocValues getNumericDocValues(LeafReaderContext context,
                                               String field)
                                        throws IOException

Retrieves the NumericDocValues for the field in this segment

If you override this method, you should probably always disable skipping as the comparator uses values from the points index to build its competitive iterators, and assumes that the values in doc values and points are the same.

Parameters:

context - – reader context

field - - field name

Returns:

numeric doc values for the field in this segment.

Throws:

IOException - If there is a low-level I/O error

setBottom

public void setBottom(int slot)
               throws 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:

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.

Specified by:

copy in interface LeafFieldComparator

Parameters:

slot - which slot to copy the hit to

doc - docID relative to current reader

Throws:

IOException

setScorer

public void setScorer(Scorable scorer)
               throws 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:

IOException

setHitsThresholdReached

public void setHitsThresholdReached()
                             throws 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:

IOException

competitiveIterator

public DocIdSetIterator competitiveIterator()

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.

compareMissingValueWithTopValue

protected abstract int compareMissingValueWithTopValue()

in ascending sort, missing value is competitive when it is less or equal(maybe there are two or more comparators) than bottom value. if there is only one comparator(See Pruning.GREATER_THAN_OR_EQUAL_TO), missing value is competitive only when it is less than bottom value. vice versa in descending sort.

compareMissingValueWithBottomValue

protected abstract int compareMissingValueWithBottomValue()

encodeBottom

protected abstract void encodeBottom(byte[] packedValue)

encodeTop

protected abstract void encodeTop(byte[] packedValue)