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From "Uli Bubenheimer (JIRA)" <>
Subject [jira] [Commented] (IO-355) IOUtils read() and skip() methods are performance hogs
Date Wed, 31 Oct 2012 17:46:12 GMT


Uli Bubenheimer commented on IO-355:

Can't provide one currently, sorry.
> IOUtils read() and skip() methods are performance hogs
> ------------------------------------------------------
>                 Key: IO-355
>                 URL:
>             Project: Commons IO
>          Issue Type: Bug
>          Components: Utilities
>    Affects Versions: 2.3, 2.4
>            Reporter: Uli Bubenheimer
> IOUtils.skip(InputStream, long) and IOUtils.skip(Reader, long) have the worst possible
performance as they always use read() on the input instead of using skip(). In many cases,
using skip() from a subclass of InputStream is much faster than read(), as the skip() can
be implemented via a disk seek.
> The IOUtils.skip() methods are used in the read() methods of IOUtils and their similarly
named siblings, so they tend to bring down the performance of all reads that involve a skip.
> Case in point: I have observed this performance degradation with Java 7 on Windows 7.
A series of consecutive reads on a large file on disk that involved skips changed my performance
from 30 secs as my baseline to 10 minutes after starting to use

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