Module org.apache.lucene.core
Package org.apache.lucene.search.comparators

Class DocComparator.DocLeafComparator

java.lang.Object
org.apache.lucene.search.comparators.DocComparator.DocLeafComparator
All Implemented Interfaces:
LeafFieldComparator
Enclosing class:
DocComparator
private class DocComparator.DocLeafComparator extends Object implements LeafFieldComparator
DocLeafComparator with skipping functionality. When sort by _doc asc, after collecting top N matches and enough hits, the comparator can skip all the following documents. When sort by _doc asc and "top" document is set after which search should start, the comparator provides an iterator that can quickly skip to the desired "top" document.

  • Field Details

    • docBase

      private final int docBase

    • minDoc

      private final int minDoc

    • maxDoc

      private final int maxDoc

    • competitiveIterator

      private DocIdSetIterator competitiveIterator

  • Constructor Details

  • Method Details

    • 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

    • compareBottom

      public int compareBottom(int doc)
      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.

    • compareTop

      public int compareTop(int doc)
      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.

    • 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

    • 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.

    • setHitsThresholdReached

      public void setHitsThresholdReached()
      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

    • updateIterator

      private void updateIterator()