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https://issues.apache.org/jira/browse/HDFS-2834?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Henry Robinson updated HDFS-2834:
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    Attachment: hdfs-2834-libhdfs-benchmark.png
    
> 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-2834.3.patch, 
> HDFS-2834.4.patch, HDFS-2834.5.patch, HDFS-2834.6.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. 

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