org.apache.lucene.search

Interface LeafFieldComparator

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method and Description
      int compareBottom(int doc)
      Compare the bottom of the queue with this doc.
      int compareTop(int doc)
      Compare the top value with this doc.
      void copy(int slot, int doc)
      This method is called when a new hit is competitive.
      void setBottom(int slot)
      Set the bottom slot, ie the "weakest" (sorted last) entry in the queue.
      void setScorer(Scorer scorer)
      Sets the Scorer to use in case a document's score is needed.
    • Method Detail

      • setBottom

        void setBottom(int slot)
        Set the bottom slot, ie the "weakest" (sorted last) entry in the queue. When compareBottom(int) is called, you should compare against this slot. This will always be called before compareBottom(int).
        Parameters:
        slot - the currently weakest (sorted last) slot in the queue
      • compareBottom

        int compareBottom(int doc)
                   throws IOException
        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).

        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
      • compareTop

        int compareTop(int doc)
                throws IOException
        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).
        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
      • copy

        void copy(int slot,
                  int doc)
           throws IOException
        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.
        Parameters:
        slot - which slot to copy the hit to
        doc - docID relative to current reader
        Throws:
        IOException
      • setScorer

        void setScorer(Scorer scorer)
                throws IOException
        Sets the Scorer to use in case a document's score is needed.
        Parameters:
        scorer - Scorer instance that you should use to obtain the current hit's score, if necessary.
        Throws:
        IOException