[gdal-dev] VSIReadDir() and GDALOpenInfo

[Andrey Kiselev]

On Wed, Jan 30, 2008 at 12:00:16PM -0500, Frank Warmerdam wrote:
> But I'm wondering if there is a fundamentally better approach to
> scanning for the list of files in a directory, or if this is
> inherently quite an expensive operation.  Thoughts?  Other experiences
> on this?  Is this more of an issue with particular file systems?

Ulrich Drepper has some insights on the issue:

 http://udrepper.livejournal.com/18555.html

Based on his article I see few problems with our code:

 1. We are using readdir() instead of readdir64().
 2. We are not checking the file type: do we really need to add
    subdirectory names to the list?
 3. Directory entry names have a fixed length, so we can optimize a bit
    by removing CPLStrdup() call.

The only problem is that readdir64() could be not portable enougth, but
this is easy to fix using the same approach as with other *64() calls.

Other than above it seems to be nothing to optimize in our code.

Best regards,
Andrey

-- 
Andrey V. Kiselev
ICQ# 26871517