git.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jeff King <peff@peff.net>
To: Albretch Mueller <lbrtchx@gmail.com>
Cc: Nicolas Pitre <nico@fluxnic.net>, git@vger.kernel.org
Subject: Re: diff'ing files ...
Date: Tue, 7 Jun 2011 18:19:48 -0400	[thread overview]
Message-ID: <20110607221948.GA10104@sigill.intra.peff.net> (raw)
In-Reply-To: <BANLkTinwSembzVk4gSYSvsRdHhDfqizkyg@mail.gmail.com>

On Tue, Jun 07, 2011 at 10:12:35PM +0000, Albretch Mueller wrote:

> > ... binary diffs, though I don't know offhand the details of the algorithm.
> ~
>  this is the part that I need ;-)
> ~
>  Reading the source code without knowing the basic underlying
> ideas/algorithm (just an outline if possible) won't help much

You could read the comments in the source:

  $ head -n 7 diff-delta.c
  /*
   * diff-delta.c: generate a delta between two buffers
   *
   * This code was greatly inspired by parts of LibXDiff from Davide Libenzi
   * http://www.xmailserver.org/xdiff-lib.html
   *
   * Rewritten for GIT by Nicolas Pitre <nico@fluxnic.net>, (C) 2005-2007

According to the xdiff page linked:

  For binary files, LibXDiff implements both (with some modification)
  the algorithm described in File System Support for Delta Compression
  by Joshua P.  MacDonald, and the algorithm described in Fingerprinting
  By Random Polynomials by Michael O. Rabin.

Nicolas (cc'd) might be able to say what, if any, substantive changes
were made from those works.

-Peff

  reply	other threads:[~2011-06-07 22:20 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-06-06 18:49 diff'ing files Albretch Mueller
2011-06-06 22:43 ` Jeff King
2011-06-07 22:12   ` Albretch Mueller
2011-06-07 22:19     ` Jeff King [this message]
2011-06-10  2:19       ` Nicolas Pitre
2011-06-10 13:12         ` Jakub Narebski
2011-06-10 20:37           ` Nicolas Pitre
2011-06-12  1:02             ` Albretch Mueller

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20110607221948.GA10104@sigill.intra.peff.net \
    --to=peff@peff.net \
    --cc=git@vger.kernel.org \
    --cc=lbrtchx@gmail.com \
    --cc=nico@fluxnic.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).