[Tilecache] make dir error

[Christopher Schmidt]

On Thu, Apr 10, 2008 at 05:32:33PM +0200, Fredrik Lundh wrote:
> >  Agreed. I keep thinking I've already done this, but never get around to
> >  it. I'll take a patch...
> 
> The patch below should work, I think (only briefly tested).
> 
> </F>

My concern with this path is that TileCache makes pretty deep
directories: imagining that you have:
 os.makedirs(
   /0/0/0/0/0/0/
 )

and:
 
 os.makedirs(
   /0/0/0/0/0/1/
 )

And they both get called at the same time, you could get a condition
where:

  1: /0 is created
  2: tries to make /0, bails
  1. Successfully makes /0/0/0/0/0/0 whatever
  2. Has no /1 directory, writing file fails

Am I wrong here, or is this a possibility? If it is a possibility, is it
worth trying to fix? Should the exception handler catch the exception,
and try again?

-- Chris

> --- Disk.py.bak Thu Apr 10 17:27:09 2008
> +++ Disk.py     Thu Apr 10 17:20:35 2008
> @@ -1,7 +1,7 @@
>  # BSD Licensed, Copyright (c) 2006-2007 MetaCarta, Inc.
> 
>  from TileCache.Cache import Cache
> -import sys, os, time
> +import sys, os, time, errno
> 
>  class Disk (Cache):
>     def __init__ (self, base = None, umask = '002', **kwargs):
> @@ -21,7 +21,11 @@
> 
>     def makedirs(self, path):
>         old_umask = os.umask(self.umask)
> -        os.makedirs(path)
> +        try:
> +            os.makedirs(path)
> +        except OSError, e:
> +            if e.errno != errno.EEXIST:
> +                raise
>         os.umask(old_umask)
> 
>     def access(self, path, type='read'):
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-- 
Christopher Schmidt
MetaCarta