Re: [Gnu-arch-users] Some issues

[Andrew Suffield]

On Thu, Jun 10, 2004 at 12:33:43AM +0800, Cameron Patrick wrote:
> Andrew Suffield wrote:
> 
> | > We could do better than we do now, though.  Something like rdiff or
> | > xdelta would be more efficient for some binary files.  We could grok
> | > gzip/zip/bzip2 files and store some kind of patch based on the
> | > compressed data.  Having said that, I'm not sure that any of this is
> | > worth the extra complexity.
> | 
> | And you're just talking compression - that's really not very
> | interesting. Absent a useful patch equivalent, there's no semantic
> | difference, so a smarter server or filesystem could do it in the
> | background without affecting the changeset format.
> 
> That's not quite true.  If arch looked inside zipped files, say, it
> could compute patches to the text data inside Openoffice documents.
> This /is/ a semantic difference.  While it isn't possible to write a
> clever diff+patch algorithm for arbitrary binary files, it is
> certainly possible to write diff/patch equivalents that understand
> /specific/ types of files.

Hmm, now that's an interesting idea.

> IIRC Subversion allows you to define external commands to run when
> applying patches (actually 3-way merging I suppose) to specific types
> of (non-text) files.  I don't know if anyone actually uses this
> functionality.

Doubtful. That really *is* a major archive format issue, because it
ties the archive format to the behaviour of a command on a client.

-- 
  .''`.  ** Debian GNU/Linux ** | Andrew Suffield
 : :' :  http://www.debian.org/ |
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