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Re: Subversion for object code

From: Daniel Shahaf <danielsh_at_elego.de>
Date: Fri, 2 Mar 2012 11:50:09 +0200

Helmut Zeisel wrote on Fri, Mar 02, 2012 at 10:28:16 +0100:
>
> -------- Original-Nachricht --------
> > Datum: Thu, 1 Mar 2012 09:07:41 +0200
> > Von: Daniel Shahaf <danielsh_at_elego.de>
>
> > Representation sharing works only on complete files. (If two files are
> > not byte-for-byte identical, it never kicks in.) What you see would be
> > the xdelta binary-diff algorithm being efficient.
>
> OK.
>
> Does this mean that svn uses internally the same algorithm as xdelta (http://code.google.com/p/xdelta/)
>

I don't know offhand how close our implementation is to other
implementations or to research papers. There are some comments in
subversion/libsvn_delta/xdelta.c (lines 35 and 370) that suggest some
divergence from other sources.

CC'ing dev@ so people who know this code better can join the
conversation.

> This would mean that I could directly use
>
> xdelta3 -s SOURCE TARGET > OUT
>
> to estimate how big the differences between binary files are (without creating some svn test repository and measuring repostiory size)
>
> Helmut
>
> --
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Received on 2012-03-02 10:50:50 CET

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