hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Henry Robinson (Updated) (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (HDFS-2834) ByteBuffer-based read API for DFSInputStream
Date Tue, 20 Mar 2012 16:29:44 GMT

     [ https://issues.apache.org/jira/browse/HDFS-2834?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Henry Robinson updated HDFS-2834:
---------------------------------

    Attachment: HDFS-2834.10.patch

Review comments.
                
> ByteBuffer-based read API for DFSInputStream
> --------------------------------------------
>
>                 Key: HDFS-2834
>                 URL: https://issues.apache.org/jira/browse/HDFS-2834
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>            Reporter: Henry Robinson
>            Assignee: Henry Robinson
>         Attachments: HDFS-2834-no-common.patch, HDFS-2834.10.patch, HDFS-2834.3.patch,
HDFS-2834.4.patch, HDFS-2834.5.patch, HDFS-2834.6.patch, HDFS-2834.7.patch, HDFS-2834.8.patch,
HDFS-2834.9.patch, HDFS-2834.patch, HDFS-2834.patch, hdfs-2834-libhdfs-benchmark.png
>
>
> The {{DFSInputStream}} read-path always copies bytes into a JVM-allocated {{byte[]}}.
Although for many clients this is desired behaviour, in certain situations, such as native-reads
through libhdfs, this imposes an extra copy penalty since the {{byte[]}} needs to be copied
out again into a natively readable memory area. 
> For these cases, it would be preferable to allow the client to supply its own buffer,
wrapped in a {{ByteBuffer}}, to avoid that final copy overhead. 

--
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

        

Mime
View raw message