[PATCH 4 of 4] revlog: support writing generaldelta revlogs

[Benoit Boissinot]

On Fri, May 6, 2011 at 10:26 PM, Sune Foldager <cryo at cyanite.org> wrote:
> On Fri, May 06, 2011 at 02:19:12 +0200, Peter Arrenbrecht wrote:
>>
>> On May 6, 2011 2:11 PM, "Benoit Boissinot" <bboissin at gmail.com> wrote:
>
> [...snip...]
>
>>> I have some code on my laptop which depends on the dagutil module from
>>
>> Peter.
>>
>> Which is in main now.
>
> I think a somewhat simpler, greedy algorithm might work with a good result,
> before or after generaldelta:
>
> 1. While there are revs left to bundle:
> 2. Take the highest rev, and follow the deltachain backwards until we reach
>   a rev we expect the receiver to have, or one he does't have and we are
>   not going to bundle.
> 3. In the latter case, do a delta against something he has, e.g.
>   p1(lowest_rev_in_bundle).
> 4. Reverse the chain we built, and bundle it. All deltas can be taken
>   directly from the revlog.
> 5. Goto 1.
>
> That should be pretty optimal, I think. I'll implement a scheme like that.

I used a postorder, which works pretty nicely (similar to shrink-revlog):
http://paste.pocoo.org/show/384245/

Benoit