[jira] [Commented] (CASSANDRA-2820) Re-introduce FastByteArrayInputStream (and Output equivalent)

["Sylvain Lebresne (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/CASSANDRA-2820?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13054342#comment-13054342 ] 

Sylvain Lebresne commented on CASSANDRA-2820:
---------------------------------------------

Would you mind attaching that patch instead of inlining it in a comment. If only because the markup used by JIRA comment make it unusable as is. If you could rebase this against the current 0.8 branch, that would also be very helpful.

> Re-introduce FastByteArrayInputStream (and Output equivalent)
> -------------------------------------------------------------
>
>                 Key: CASSANDRA-2820
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-2820
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: Core
>    Affects Versions: 0.8.0
>         Environment: n/a
>            Reporter: Paul Loy
>            Priority: Minor
>              Labels: bytearrayinputstream, bytearrayoutputstream, license, synchronized
>
> In https://issues.apache.org/jira/browse/CASSANDRA-37 FastByteArrayInputStream and FastByteArrayOutputStream were removed due to being code copied from the JDK and then subsequently modified. The JDK license is incompatible with Apache 2 license so the code had to go.
> I have since had a look at the performance of the JDK ByteArrayInputStream and a FastByteArrayInputStream (i.e. one with synchronized methods made un-synchronized) and seen the difference is significant.
> After a warmup-period of >10000 loops I get the following for 10000 loops through a 128000 byte array:
> bais : 3513ms
> fbais: 72ms
> This varies depending on the OS, machine and Java version, but it's always in favour of the FastByteArrayInputStream as you might expect.
> Then, at Jonathan Ellis' suggestion, I tried this using a modified Apache Harmony ByteArrayInputStream - i.e. one whose license is compatible - and the results were the same. A significant boost.
> I will attach a patch with changes for the 0.8.0 tag.

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