[
https://issues.apache.org/jira/browse/HADOOP-7761?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13140415#comment-13140415
]
Jonathan Ellis commented on HADOOP-7761:
----------------------------------------
FWIW, Ben Manes has been super helpful with the Guava concurrent map /
ConcurrentLinkedHashMap. More generally, the Guava team is active in
responding to issues on their bug tracker, although admittedly I've also gotten
the "we don't think that is generally useful" response.
I think you'd have a strong case here, though; almost all JDK methods dealing
with byte[] have an overload to take offset/length, which speaks to the general
usefulness of that.
> Improve performance of raw comparisons
> --------------------------------------
>
> Key: HADOOP-7761
> URL: https://issues.apache.org/jira/browse/HADOOP-7761
> Project: Hadoop Common
> Issue Type: Improvement
> Components: io, performance, util
> Affects Versions: 0.23.0
> Reporter: Todd Lipcon
> Assignee: Todd Lipcon
> Fix For: 0.24.0
>
> Attachments: hadoop-7761.txt, hadoop-7761.txt, hadoop-7761.txt,
> hadoop-7761.txt
>
>
> Guava has a nice implementation of lexicographical byte-array comparison that
> uses sun.misc.Unsafe to compare unsigned byte arrays long-at-a-time. Their
> benchmarks show it as being 2x more CPU-efficient than the equivalent
> pure-Java implementation. We can easily integrate this into
> WritableComparator.compareBytes to improve CPU performance in the shuffle.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
