Class FieldComparator

Expert: a FieldComparator compares hits so as to determine their sort order when collecting the top results with TopFieldCollector . The concrete public FieldComparator classes here correspond to the SortField types.

This API is designed to achieve high performance sorting, by exposing a tight interaction with FieldValueHitQueue as it visits hits. Whenever a hit is competitive, it's enrolled into a virtual slot, which is an int ranging from 0 to numHits-1. The FieldComparator is made aware of segment transitions during searching in case any internal state it's tracking needs to be recomputed during these transitions.

A comparator must define these functions:

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

Inheritance
System.Object
FieldComparator
FieldComparator.ByteComparator
FieldComparator.DocComparator
FieldComparator.DoubleComparator
FieldComparator.FloatComparator
FieldComparator.IntComparator
FieldComparator.LongComparator
FieldComparator.RelevanceComparator
FieldComparator.ShortComparator
FieldComparator.StringComparatorLocale
FieldComparator.StringOrdValComparator
FieldComparator.StringValComparator
Namespace:
Assembly: Lucene.Net.NetCore.dll
Syntax
public abstract class FieldComparator : object

Properties

Name Description
Item[Int32]

Return the actual value in the slot.

Methods

Name Description
BinarySearch(String[], String)
BinarySearch(String[], String, Int32, Int32)
Compare(Int32, Int32)

Compare hit at slot1 with hit at slot2.
CompareBottom(Int32)

Compare the bottom of the queue with doc. This will only invoked after setBottom has been called. This should return the same result as Compare(Int32, Int32) } 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).
Copy(Int32, Int32)

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.
SetBottom(Int32)

Set the bottom slot, ie the "weakest" (sorted last) entry in the queue. When CompareBottom(Int32) is called, you should compare against this slot. This will always be called before CompareBottom(Int32).
SetNextReader(IndexReader, Int32)

Set a new Reader. All doc correspond to the current Reader.
SetScorer(Scorer)

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