Mailing-List: contact hdfs-issues-help@hadoop.apache.org; run by ezmlm
Precedence: bulk
Reply-To: hdfs-issues@hadoop.apache.org
Date: Fri, 6 Jan 2012 20:58:39 +0000 (UTC)
From: "Eli Collins (Updated) (JIRA)" <jira@apache.org>
To: hdfs-issues@hadoop.apache.org
Message-ID: 
 <1123143381.16282.1325883519913.JavaMail.tomcat@hel.zones.apache.org>
Subject: [jira] [Updated] (HDFS-554) BlockInfo.ensureCapacity may get a
 speedup from System.arraycopy()
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit


     [ https://issues.apache.org/jira/browse/HDFS-554?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Eli Collins updated HDFS-554:
-----------------------------

    Target Version/s: 0.23.1

Good candidate for merging to branch 23.
                
> BlockInfo.ensureCapacity may get a speedup from System.arraycopy()
> ------------------------------------------------------------------
>
>                 Key: HDFS-554
>                 URL: https://issues.apache.org/jira/browse/HDFS-554
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>          Components: name-node
>    Affects Versions: 0.21.0
>            Reporter: Steve Loughran
>            Assignee: Harsh J
>            Priority: Minor
>             Fix For: 0.24.0
>
>         Attachments: HDFS-554.patch, HDFS-554.txt, HDFS-554.txt
>
>
> BlockInfo.ensureCapacity() uses a for() loop to copy the old array data into the expanded array.  {{System.arraycopy()}} is generally much faster for this, as it can do a bulk memory copy. There is also the typesafe Java6 {{Arrays.copyOf()}} to consider, though here it offers no tangible benefit.

--
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