[
https://issues.apache.org/jira/browse/MAPREDUCE-960?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Chris Douglas updated MAPREDUCE-960:
------------------------------------
Affects Version/s: 0.21.0
> Unnecessary copy in mapreduce.lib.input.KeyValueLineRecordReader
> ----------------------------------------------------------------
>
> Key: MAPREDUCE-960
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-960
> Project: Hadoop Map/Reduce
> Issue Type: Improvement
> Affects Versions: 0.21.0
> Reporter: Chris Douglas
> Assignee: Chris Douglas
> Attachments: M960-0.patch
>
>
> KeyValueLineRecordReader effects the copy from the line to the key/value by
> creating separate arrays:
> {noformat}
> int keyLen = pos;
> byte[] keyBytes = new byte[keyLen];
> System.arraycopy(line, 0, keyBytes, 0, keyLen);
> int valLen = lineLen - keyLen - 1;
> byte[] valBytes = new byte[valLen];
> System.arraycopy(line, pos + 1, valBytes, 0, valLen);
> key.set(keyBytes);
> value.set(valBytes);
> {noformat}
> Since set triggers another copy and Text has a set taking {{byte[], off,
> len}}, the intermediate copy can be avoided
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
