Package org.apache.lucene.util

Class Sorter

java.lang.Object
org.apache.lucene.util.Sorter
Direct Known Subclasses:
InPlaceMergeSorter, IntroSorter, MSBRadixSorter, TimSorter
public abstract class Sorter extends Object
Base class for sorting algorithms implementations.

There are a number of subclasses to choose from that vary in performance and stability. We suggest that you pick the first from this ranked list that meets your requirements:

  1. MSBRadixSorter for strings (array of bytes/chars). Not a stable sort.
  2. StableMSBRadixSorter for strings (array of bytes/chars). Stable sort.
  3. IntroSorter. Not a stable sort.
  4. InPlaceMergeSorter. When the data to sort is typically small. Stable sort.
  5. TimSorter. Stable sort.
NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    protected
    Sorter()
    Sole constructor, used for inheritance.

  • Method Summary

    Modifier and Type
    Method
    Description
    protected abstract int
    compare(int i, int j)
    Compare entries found in slots i and j.
    protected int
    comparePivot(int j)
    Compare the pivot with the slot at j, similarly to compare(i, j).
    protected void
    setPivot(int i)
    Save the value at slot i so that it can later be used as a pivot, see comparePivot(int).
    abstract void
    sort(int from, int to)
    Sort the slice which starts at from (inclusive) and ends at to (exclusive).
    protected abstract void
    swap(int i, int j)
    Swap values at slots i and j.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Sorter

      protected Sorter()
      Sole constructor, used for inheritance.

  • Method Details

    • compare

      protected abstract int compare(int i, int j)
      Compare entries found in slots i and j. The contract for the returned value is the same as Comparator.compare(Object, Object).

    • swap

      protected abstract void swap(int i, int j)
      Swap values at slots i and j.

    • setPivot

      protected void setPivot(int i)
      Save the value at slot i so that it can later be used as a pivot, see comparePivot(int).

    • comparePivot

      protected int comparePivot(int j)
      Compare the pivot with the slot at j, similarly to compare(i, j).

    • sort

      public abstract void sort(int from, int to)
      Sort the slice which starts at from (inclusive) and ends at to (exclusive).