[
https://issues.apache.org/jira/browse/LUCENE-4946?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Adrien Grand updated LUCENE-4946:
---------------------------------
Attachment: LUCENE-4946.patch
This patch contains one base class Sorter and 3 implementations:
* IntroSorter (improved quicksort like we had before but I think the name is
better since it makes it clear that the worst case complexity is O(n ln(n))
instead of O(n^2) as with traditional quicksort
* InPlaceMergeSort, the merge sort we had before.
* TimSort, an improved version of the previous implementation that can gallop
to make sorting even faster on partially-sorted data.
One major difference is that the end offsets are now exclusive. I tend to find
it less confusing since you would now call {{sort(0, array.length)}} instead of
{{sort(0, array.length - 1)}}.
Please let me know if you would like to review the patch!
> Refactor SorterTemplate
> -----------------------
>
> Key: LUCENE-4946
> URL: https://issues.apache.org/jira/browse/LUCENE-4946
> Project: Lucene - Core
> Issue Type: Improvement
> Reporter: Adrien Grand
> Assignee: Adrien Grand
> Priority: Trivial
> Attachments: LUCENE-4946.patch
>
>
> When working on TimSort (LUCENE-4839), I was a little frustrated of not being
> able to add galloping support because it would have required to add new
> primitive operations in addition to compare and swap.
> I started working on a prototype that uses inheritance to allow some sorting
> algorithms to rely on additional primitive operations. You can have a look at
> https://github.com/jpountz/sorts/tree/master/src/java/net/jpountz/sorts (but
> beware it is a prototype and still misses proper documentation and good
> tests).
> I think it would offer several advantages:
> - no more need to implement setPivot and comparePivot when using in-place
> merge sort or insertion sort,
> - the ability to use faster stable sorting algorithms at the cost of some
> memory overhead (our in-place merge sort is very slow),
> - the ability to implement properly algorithms that are useful on specific
> datasets but require different primitive operations (such as TimSort for
> partially-sorted data).
> If you are interested in comparing these implementations with Arrays.sort,
> there is a Benchmark class in src/examples.
> What do you think?
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
