[jira] [Created] (HADOOP-15606) FSDataInputStream/FSInputStream to implement a length()/size() method for amount of data

["Steve Loughran (JIRA)" <ji...@apache.org>]

Steve Loughran created HADOOP-15606:
---------------------------------------

             Summary: FSDataInputStream/FSInputStream to implement a length()/size() method for amount of data
                 Key: HADOOP-15606
                 URL: https://issues.apache.org/jira/browse/HADOOP-15606
             Project: Hadoop Common
          Issue Type: Improvement
          Components: fs, fs/s3
    Affects Versions: 3.1.0
            Reporter: Steve Loughran


server-side transcoding, predicate-pushdown filtering in storage, client-side decryption can all result in an input stream shorter or longer than the file size as measured in getFileStatus/listFiles/listStatus. 

Assuming the length is known once open() returns, the FSDataInputStream can return the length of the data, which can then be used for accurate seeks within the data.

* requires the streams to know their length; easy to check (hasCapabilities), or make the new method return an Optional<Long>, but caller will need to (a) look for this if present and (b) fall back.
* Could be rolled out for all our own clients/connectors, would take time for others



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

---------------------------------------------------------------------
To unsubscribe, e-mail: common-dev-unsubscribe@hadoop.apache.org
For additional commands, e-mail: common-dev-help@hadoop.apache.org