commons-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "BELUGA BEHR (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (COMPRESS-277) IOUtils.skip does not work as advertised
Date Fri, 25 Apr 2014 23:35:17 GMT

    [ https://issues.apache.org/jira/browse/COMPRESS-277?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13981769#comment-13981769
] 

BELUGA BEHR commented on COMPRESS-277:
--------------------------------------

Yes! Sorry!  I will move to a new ticket! I was confused in that I thought this had direct
changes to the TarInputStream class.  Thanks for bringing these issues to light!

I do admit that the code I suggested was a bit confusing, but I am trying to help you.  IOUtils#skip()
from the commons-io package does not call the stream's skip method, it only calls the stream's
read.  You may get better results with the approach I suggested because it allows you to just
skip the 'skip' process all together and just pass in a large read buffer allowing for fewer
iterations.

> IOUtils.skip does not work as advertised
> ----------------------------------------
>
>                 Key: COMPRESS-277
>                 URL: https://issues.apache.org/jira/browse/COMPRESS-277
>             Project: Commons Compress
>          Issue Type: Bug
>    Affects Versions: 1.8
>            Reporter: Fabian Lange
>             Fix For: 1.9
>
>         Attachments: TarArchiveInputStream.java.patch
>
>
> I am trying to feed a TarInputStream from a CipherInputStream.
> It does not work, because IOUtils.skip() does not adhere to the contract it claims in
javadoc:
> "     * <p>This method will only skip less than the requested number of
>      * bytes if the end of the input stream has been reached.</p>"
> However it does:
>             long skipped = input.skip(numToSkip);
>             if (skipped == 0) {
>                 break;
>             }
> And the input stream javadoc says:
> "     * This may result from any of a number of conditions; reaching end of file
>      * before <code>n</code> bytes have been skipped is only one possibility."
> In the case of CipherInputStream, it stops at the end of each byte buffer.
> If you check the IOUtils from colleagues at commons-io, they have considered this case
in IOUtils.skip() where they use a read to skip through the stream.
> An optimized version could combine trying to skip, then read then trying to skip again.



--
This message was sent by Atlassian JIRA
(v6.2#6252)

Mime
View raw message