Module org.apache.lucene.core
Package org.apache.lucene.document

Class XYPointDistanceComparator

java.lang.Object
org.apache.lucene.search.FieldComparator<Double>
org.apache.lucene.document.XYPointDistanceComparator
All Implemented Interfaces:
LeafFieldComparator
class XYPointDistanceComparator extends FieldComparator<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.

  • Field Details

    • field

      final String field

    • x

      final double x

    • y

      final double y

    • values

      final double[] values

    • bottom

      double bottom

    • topValue

      double topValue

    • currentDocs

      SortedNumericDocValues currentDocs

    • minX

      int minX

    • maxX

      int maxX

    • minY

      int minY

    • maxY

      int maxY

    • setBottomCounter

      int setBottomCounter

    • currentValues

      private long[] currentValues

    • valuesDocID

      private int valuesDocID

  • Constructor Details

    • XYPointDistanceComparator

      public XYPointDistanceComparator(String field, float x, float y, int numHits)

  • Method Details

    • 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<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(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<Double>

    • setValues

      private void setValues() throws IOException
      Throws:
      IOException

    • compareBottom

      public int compareBottom(int doc) throws 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:
      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

    • getLeafComparator

      public LeafFieldComparator getLeafComparator(LeafReaderContext context) throws 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<Double>
      Parameters:
      context - current reader context
      Returns:
      the comparator to use for this segment
      Throws:
      IOException - if there is a low-level IO error

    • value

      public Double value(int slot)
      Description copied from class: FieldComparator
      Return the actual value in the slot.
      Specified by:
      value in class FieldComparator<Double>
      Parameters:
      slot - the value
      Returns:
      value in this slot

    • compareTop

      public int compareTop(int doc) throws 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:
      IOException

    • sortKey

      double sortKey(int doc) throws IOException
      Throws:
      IOException