Re: [PATCH] add the ability to create and retrieve delta objects

[Chris Mason <mason@suse.com>]

On Tuesday 03 May 2005 04:06, Nicolas Pitre wrote:
> On Mon, 2 May 2005, Linus Torvalds wrote:
> > If you do something like this, you want such a delta-blob to be named by
> > the sha1 of the result, so that things that refer to it can transparently
> > see either the original blob _or_ the "deltified" one, and will never
> > care.
>
> Yep, that's what I've done last weekend (and just made it actually
> work since people are getting interested).
>
This looks much nicer than using zdelta, I'll try switching my packed item to 
your delta generator later this week.  Some quick and dirty space numbers to 
show why we need to pack the files together:

On the full import of all the bk->cvs changesets, the average file size 
in .git is 4074 bytes.  73% of the files are 4096 bytes or smaller.

This means that of the 2.5GB the .git directory consumes, about 1GB is taken 
up by files under 4k where deltas won't save space.  If the remaining files 
could be delta compressed down to less than 4k, they would still take up 
around 400MB on disk.

-chris