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https://issues.apache.org/jira/browse/HADOOP-4065?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12628679#action_12628679
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Pete Wyckoff commented on HADOOP-4065:
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I think in Joy's case, it would be the filename and/or with some configuration 
info in the jobconf.  In the TRecordStream case, we would need to use some code 
from TFixedFrameTransport to read the frame headers - TFixedFrameTransport is 
splittable. (TRS is a thin layer on top of TFFT).

Joy or I can post a proposed API.

good point, we should make it general and not just for binary.

pete



> support for reading binary data from flat files
> -----------------------------------------------
>
>                 Key: HADOOP-4065
>                 URL: https://issues.apache.org/jira/browse/HADOOP-4065
>             Project: Hadoop Core
>          Issue Type: Bug
>          Components: mapred
>            Reporter: Joydeep Sen Sarma
>
> like textinputformat - looking for a concrete implementation to read binary 
> records from a flat file (that may be compressed).
> it's assumed that hadoop can't split such a file. so the inputformat can set 
> splittable to false.
> tricky aspects are:
> - how to know what class the file contains (has to be in a configuration 
> somewhere).
> - how to determine EOF (would be nice if hadoop can determine EOF and not 
> have the deserializer throw an exception  (which is hard to distinguish from 
> a exception due to corruptions?)). this is easy for non-compressed streams - 
> for compressed streams - DecompressorStream has a useful looking 
> getAvailable() call - except the class is marked package private.

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