beam-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From robertwb <>
Subject [GitHub] incubator-beam pull request #741: Top improvements
Date Wed, 27 Jul 2016 19:24:57 GMT
GitHub user robertwb opened a pull request:

    Top improvements

    Be sure to do all of the following to help us incorporate your contribution
    quickly and easily:
     - [ ] Make sure the PR title is formatted like:
       `[BEAM-<Jira issue #>] Description of pull request`
     - [ ] Make sure tests pass via `mvn clean verify`. (Even better, enable
           Travis-CI on your fork and ensure the whole test matrix passes).
     - [ ] Replace `<Jira issue #>` in the title with the actual Jira issue
           number, if there is one.
     - [ ] If this contribution is large, please file an Apache
           [Individual Contributor License Agreement](

You can merge this pull request into a Git repository by running:

    $ git pull top

Alternatively you can review and apply these changes as the patch at:

To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:

    This closes #741
commit 9151fcf861704c550c21f411a9047f955f179ec4
Author: Robert Bradshaw <>
Date:   2016-07-27T17:09:49Z

    Better top implementation.
    When selecting the top k of n, it is common that k << n.
    Using a heap is O(n log k) while select algorithms can
    achieve O(n + k log k).
    This also avoids the ugliness that heapq does not take the
    comparator as an argument, resulting in _HeapItem classes that
    were cumbersome and expensive to serialize.

commit e38d6f60f18bf6ad61f2d387c67efa2012af2e14
Author: Robert Bradshaw <>
Date:   2016-07-27T19:23:02Z

    Allow Top operations to take key argument rather than compare, and order
    by the natural ordering if neither is specified.


If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at or file a JIRA ticket
with INFRA.

View raw message