[pacman-dev] xdelta status

[Xavier]

I was also wondering about the status of xdelta itself.

1)
 From http://code.google.com/p/xdelta/ :
> Xdelta is a tool and library for differential compression.
> Xdelta release version 3 supports VCDIFF encoding and decoding.
 > This is a BETA release, but almost stable.
 > Supports compressing 64 bit files on Windows, Linux, etc.
>
> Xdelta 1.1.4 is the last stable release. Xdelta 1.1.0 was released in 1999.


So, the arch package will be updated to xdelta 3 only when it is marked 
stable, right? Since it's almost stable, maybe this could happen in the 
near future. Will this cause any problems on pacman side?

2)
There was also a comparison of both there :
http://bbs.archlinux.org/viewtopic.php?pid=255687#p255687
"The only advantages of xdelta3 I see right now is its reduced 
disk-space usage during delta creation, and the possibility of 
completely closing the rather unimportant md5 hole without extra 
patching time/disc-space. That and it seems to be generally a bit 
quicker in patching."

This benchmark was made 8 months ago though, so xdelta3 might be even 
better now.

3)
Also when xdelta 3 is stable, we will have the alternative to use the 
API. It looks like we could simply do a copy / paste of the code() 
function there which is ~100 lines :
http://code.google.com/p/xdelta/source/browse/trunk/xdelta3/examples/encode_decode_test.c

Then it's just a matter of using fopen, calling that code function, and 
then fclose.

But while using the API looks cleaner, Dan had several arguments against 
doing it:
http://www.archlinux.org/pipermail/pacman-dev/2007-October/009627.html