org.apache.lucene.search
Class FieldValueHitQueue<T extends FieldValueHitQueue.Entry>

java.lang.Object
  org.apache.lucene.util.PriorityQueue<T>
      org.apache.lucene.search.FieldValueHitQueue<T>

public abstract class FieldValueHitQueue<T extends FieldValueHitQueue.Entry>
extends PriorityQueue<T>

Expert: A hit queue for sorting by hits by terms in more than one field. Uses FieldCache.DEFAULT for maintaining internal term lookup tables.

Since:

2.9

See Also:

IndexSearcher.search(Query,Filter,int,Sort), FieldCache

WARNING: This API is experimental and might change in incompatible ways in the next release.

Nested Class Summary

static class

FieldValueHitQueue.Entry Extension of ScoreDoc to also store the FieldComparator slot.

Field Summary

protected FieldComparator<?>[]	comparators
protected SortField[]	fields Stores the sort criteria being used.
protected FieldComparator<?>	firstComparator
protected int[]	reverseMul

Method Summary

static <T extends FieldValueHitQueue.Entry> FieldValueHitQueue<T>	create(SortField[] fields, int size) Creates a hit queue sorted by the given list of fields.
FieldComparator<?>[]	getComparators()
int[]	getReverseMul()
protected abstract boolean	lessThan(FieldValueHitQueue.Entry a, FieldValueHitQueue.Entry b) Determines the ordering of objects in this priority queue.
void	setComparator(int pos, FieldComparator<?> comparator)

Methods inherited from class org.apache.lucene.util.PriorityQueue

add, clear, getHeapArray, getSentinelObject, insertWithOverflow, pop, size, top, updateTop

Methods inherited from class java.lang.Object

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

Field Detail

fields

protected final SortField[] fields

Stores the sort criteria being used.

comparators

protected final FieldComparator<?>[] comparators

firstComparator

protected FieldComparator<?> firstComparator

reverseMul

protected final int[] reverseMul

Method Detail

create

public static <T extends FieldValueHitQueue.Entry> FieldValueHitQueue<T> create(SortField[] fields,
                                                                                int size)
                                                                     throws IOException

Creates a hit queue sorted by the given list of fields.

NOTE: The instances returned by this method pre-allocate a full array of length numHits.

Parameters:

fields - SortField array we are sorting by in priority order (highest priority first); cannot be null or empty

size - The number of hits to retain. Must be greater than zero.

Throws:

IOException - if there is a low-level IO error

getComparators

public FieldComparator<?>[] getComparators()

getReverseMul

public int[] getReverseMul()

setComparator

public void setComparator(int pos,
                          FieldComparator<?> comparator)

lessThan

protected abstract boolean lessThan(FieldValueHitQueue.Entry a,
                                    FieldValueHitQueue.Entry b)

Description copied from class: PriorityQueue

Determines the ordering of objects in this priority queue. Subclasses must define this one method.

Specified by:

lessThan in class PriorityQueue<T extends FieldValueHitQueue.Entry>

Returns:

true iff parameter a is less than parameter b.