Proof-of-concept revision file implementation

[John A Meinel]

Johan Rydberg wrote:

> Hi,
>
> I had a few hours over so I did a proof-of-concept implementation of
> "revision file with annotation" as described at [1].  The code isn't
> very pretty, mostly because my Python skills is rather limited.  I
> would like to spend a few more hours on it, but me going away on
> vacation for a month forbids me to do so.  There are still a few
> missing "features"; for example, additions is always made against the
> last revision and not a user specified one.

How does this compare to the "bzr.dev/bzrlib/revfile.py" implementation?
Did you know that that one even existed?
There is also another version available at:
http://bazaar-ng.org/bzr/bzr.revfile/

>
> I'm throwing it out there, maybe someone will find it useful, or at
> least give food for thoughts.
>
> The compression ratio is rather good; ~30x the currently used text
> store. This is for the 91 revisions of branch.py in bzr.dev.  The
> resulting files;
>
>   -rw-r--r--  1 jrydberg jrydberg  5824 2005-07-02 02:52 branch.py.idx
>   -rw-r--r--  1 jrydberg jrydberg 32234 2005-07-02 02:52 branch.py.revs
>
> On my P3 800MHz it takes roughly 0.128 seconds to extract the last
> revision.
>
>  [1] http://www.bazaar-ng.org/doc/revfile-annotation.html
>
Does this do all compressed? I know the revfile.py implementation
defaults to creating a full copy every 25 revisions or so.
Though probably the best implementation would do something like
"len(original) + len(all patches) > 2*len(full text)" so that if you
have a bunch of really small patches, it keeps going, but if you
essentially change the whole file it will create a full text version.

Thanks for your efforts, though. Hopefully there isn't too much overlap.

John
=:->

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