From: Nicolas Pitre <nico@cam.org>
Date: Sat, 25 Feb 2006 03:53:09 GMT
Subject: Re: [PATCH] diff-delta: produce optimal pack data
Message-ID: <Pine.LNX.4.64.0602242242380.31162@localhost.localdomain>
In-Reply-To: <20060224225023.GA28538@hpsvcnb.fc.hp.com>

On Fri, 24 Feb 2006, Carl Baldwin wrote:

> > If you can add them into a single .tgz with instructions on how 
> > to reproduce the issue and provide me with an URL where I can fetch it 
> > that'd be perfect.
> 
> I will do this in an email off of the list because these files really
> shouldn't be available on a public list.

OK I have the files, and I can confirm that your problem is of the same 
combinatorial explosion type I already talked about, _even_ with the 
version using adler32.  This is really O(m*n) where m and n being the 
size of two consecutive versions of the files.  But since m and n are 
both _huge_ then the delta code really goes out to lunch.

I'm working on a patch to cap this to something like O(m+n).

Stay tuned.


Nicolas