[MERGE] BEncode Revision Serializer

[Ian Clatworthy]

John Arbash Meinel wrote:

> Right, so my proof of concept is about 2x faster (0.5s vs 1.0s). It is
> probably very close to mergeable if we care to put a strict test suite
> around it.

Hi John,

That's a pretty substantial gain. If I'm reading this thread correctly,
that's comparing against dev7-benc, and the starting point (today's dev6
in trunk) is 1.5 seconds.

So either way, really, really well done! It does seem worth going for a
custom format though given:

1. your numbers above

2. the whole Bazaar world will hopefully upgrade to 2.0 soon and we
   want to get the most bang-for-buck we can out of the data conversion

3. the closer we can get to git performance-wise the better, and
   git log is frequently held up as the poster child for its speed.

Having said that, I'm really pleased with what you've done already. As
well as the speed improvements, it will be nice to put the associated
xml encoding bugs to bed going forward. And we certainly don't need to
amplify risk - the pending 2.0 changes are already a huge change.

> Other nice bits... I checked the time to decode the 'most complex'
> per-file revision properties on the mysql code, and it is down to 4ms
> down from 41ms.

Sweet. Again, I'm assuming the 41ms figure refers to dev7-denc?

Ian C.