hadoop-common-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Doug Cutting (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HADOOP-1230) Replace parameters with context objects in Mapper, Reducer, Partitioner, InputFormat, and OutputFormat classes
Date Mon, 21 Jul 2008 19:55:33 GMT

    [ https://issues.apache.org/jira/browse/HADOOP-1230?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12615389#action_12615389
] 

Doug Cutting commented on HADOOP-1230:
--------------------------------------

Sanjay, if we provide both an abstract base class and an interface, and we change the API,
then we still break those folks foolish enough to implement the interface directly.  In the
cases here, I don't think we should provide interfaces, just abstract classes.

> Replace parameters with context objects in Mapper, Reducer, Partitioner, InputFormat,
and OutputFormat classes
> --------------------------------------------------------------------------------------------------------------
>
>                 Key: HADOOP-1230
>                 URL: https://issues.apache.org/jira/browse/HADOOP-1230
>             Project: Hadoop Core
>          Issue Type: Improvement
>          Components: mapred
>            Reporter: Owen O'Malley
>            Assignee: Owen O'Malley
>         Attachments: context-objs-2.patch, context-objs-3.patch, context-objs.patch
>
>
> This is a big change, but it will future-proof our API's. To maintain backwards compatibility,
I'd suggest that we move over to a new package name (org.apache.hadoop.mapreduce) and deprecate
the old interfaces and package. Basically, it will replace:
> package org.apache.hadoop.mapred;
> public interface Mapper extends JobConfigurable, Closeable {
>   void map(WritableComparable key, Writable value, OutputCollector output, Reporter reporter)
throws IOException;
> }
> with:
> package org.apache.hadoop.mapreduce;
> public interface Mapper extends Closable {
>   void map(MapContext context) throws IOException;
> }
> where MapContext has the methods like getKey(), getValue(), collect(Key, Value), progress(),
etc.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message