Re: [PATCH setup 0/2] Detect filename collisions between packages

[Corinna Vinschen <corinna-cygwin@cygwin.com>]

Hi Jon,

On Apr 23 15:43, Jon Turney via Cygwin-apps wrote:
> This is a woefully underoptimized implementation of detecting filename
> collisions between packages, so it's hidden behind the command line option
> '--collisions' to enable it.
> 
> A good implementation probably (i) collects the filenames at the same time
> as checksumming the archive, or has them attached to it somehow by the
> packaging process, and (ii) uses a libsolv string pool to hold the filenames
> (so we only need to compute the intersection and unions of sets of integers,
> which is hopefully much faster)
> 
> Nevertheless, this labouriously identifies some obvious collisions which I
> might bring to the attention of package maintainers when I have some time to
> do so...

Theoretically, wouldn't this be better handled in the upload process, i.
e. by calm, rather than during the download process?

Calm could create a database containing all the files from the tar
archives it uploads, and compare that against the newly uploaded files
on the fly.  So it could just refuse to upload packages with files
already present in another package.  I don't think such a database would
take too much space on sware.  This may be much less time consuming and
it would prevent the collisions before they even occur.

There's probably another problem in terms of different file lists in
different package versions, though...


Corinna