Package org.apache.lucene.search

Class FieldComparator.TermValComparator

  • All Implemented Interfaces:
    LeafFieldComparator
    Enclosing class:
    FieldComparator<T>
    public static class FieldComparator.TermValComparator
extends FieldComparator<BytesRef>
implements LeafFieldComparator
    Sorts by field's natural Term sort order. All comparisons are done using BytesRef.compareTo, which is slow for medium to large result sets but possibly very fast for very small results sets.

    • Constructor Detail

      • TermValComparator

        public TermValComparator​(int numHits,
                         String field,
                         boolean sortMissingLast)
        Sole constructor.

    • Method Detail

      • 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<BytesRef>
        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

      • 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

      • compareValues

        public int compareValues​(BytesRef val1,
                         BytesRef val2)
        Description copied from class: FieldComparator
        Returns a negative integer if first is less than second, 0 if they are equal and a positive integer otherwise. Default impl to assume the type implements Comparable and invoke .compareTo; be sure to override this method if your FieldComparator's type isn't a Comparable or if your values may sometimes be null
        Overrides:
        compareValues in class FieldComparator<BytesRef>

      • 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

      • 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.