[RFC] Store all important data in KnitData

Robert Collins robertc at robertcollins.net
Sat Oct 27 06:47:12 BST 2007


On Fri, 2007-10-26 at 17:24 -0500, John Arbash Meinel wrote:
> 
> 
> This includes the ancestry graph parents,

I'm not entirely sure these should be there. I'm leaning towards 'should
not'.

>  and a separate field for delta
> parent.

This definately should.

>  And whether or not the final text has a newline, and whether the data
> itself is a delta or a fulltext.

As these too should.

> There are a couple pieces that I'm not happy with (the InterKnit needs
> a better
> way to detect that it needs to do the conversion). Also, as long as
> the Index
> has data redundantly stored, it should probably be compared against
> the other
> when extracting.

Well, a new knit subclass or flag or something? We can't change existing
repo's obviously.

> Data storage wise, the difference is actually pretty small. I
> converted all of
> bzr.dev and with normal packs it is 63MB, with this extra data it is
> 65MB. I
> attribute this to the gzip compression. I would expect even less
> effect if
> packs were annotated, since it is very likely that the parent string
> already
> exists in the knit data.

True.

> I don't know that we want to do this before we convert over to packs,
> but it
> would mean we don't need yet another 'bzr upgrade'.

Packs are now a fixed format IMO. --pack2-experimental is a good place
to hook this in. Lets keep the momentum rolling.

> I'll probably also play with switching from gzip to using straight
> zlib, which
> should be slightly faster and smaller.

-Rob
-- 
GPG key available at: <http://www.robertcollins.net/keys.txt>.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: This is a digitally signed message part
Url : https://lists.ubuntu.com/archives/bazaar/attachments/20071027/ca817225/attachment.pgp 


More information about the bazaar mailing list