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From "Todd Lipcon (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HADOOP-6381) WritableUtils::*VLong utilities should be available for byte arrays
Date Thu, 19 Nov 2009 19:53:39 GMT

    [ https://issues.apache.org/jira/browse/HADOOP-6381?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12780235#action_12780235
] 

Todd Lipcon commented on HADOOP-6381:
-------------------------------------

bq. How effective would JIT help eliminate the overhead of objects created and forgotten in
a tight loop? This should be the kind of things that compilers are good at.

I agree they should be good at it, but in my experience they aren't quite that aggressive
yet.


As Chris pointed out, you can actually get around the issue with a thread-local DataInputBuffer
- I had forgotten about the .reset() method thereof.

I guess that leaves me -0 on this. The APIs might come in handy for some, but given you have
to actually decode the first byte twice in order to figure out the length of the variable
encoding, it's actually probably an efficiency loss in the case of raw comparators. So, I
could swing either way; up to you guys.

> WritableUtils::*VLong utilities should be available for byte arrays
> -------------------------------------------------------------------
>
>                 Key: HADOOP-6381
>                 URL: https://issues.apache.org/jira/browse/HADOOP-6381
>             Project: Hadoop Common
>          Issue Type: Improvement
>          Components: util
>            Reporter: Chris Douglas
>            Priority: Minor
>         Attachments: C6381-0.patch, C6381-1.patch, C6381-2.patch
>
>
> Particularly when working with raw bytes in Writables, it is often useful to have versions
of the vint utility functions for byte arrays.

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