Re: [Gnu-arch-users] GNU Arch 2.0 and binary files

[Jeremy Shaw]

At Fri, 21 Oct 2005 16:21:54 -0400,
Adrian Irving-Beer wrote:
> 
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> On Thu, Oct 20, 2005 at 05:25:07PM -0700, Andy Tai wrote:
> 
> > Previously there were discussions of how to efficiently store binary
> > files, like using xdelta or such.
> 
> I found "rzip" the other day:
> 
>    The principal advantage of rzip is that it has an effective
>    history buffer of 900 Mbyte.  This means it can find matching
>    pieces of the input file over huge distances compared to other
>    commonly used compression programs.  The gzip program by
>    comparison uses a history buffer of 32 kbyte and bzip2 uses a
>    history buffer of 900 kbyte.
> 
> Biggest disadvantage is that it isn't streamable; presumably, it has
> to work on seekable datasets.  But if one replaced zlib with rzip for
> compressing the tarballs, presumably one could get similar or even
> better performance to a binary delta without losing information or
> changing the format.

At one point in time it was also 50-60 times slower than bzip...

http://olstrans.sourceforge.net/release/OLS2000-rsync/OLS2000-rsync.html

Though this article claims it is now faster than gzip:

http://www.linuxjournal.com/article/8051

So... further testing is probably needed :p

Jeremy Shaw.