[libvirt] compressed stream support

[Vasiliy Tolstov]

I want to able to get VolumeUpload and VolumeUpload compressed on the
fly (for example to minimize network load)
Some times ago i ask this question in this list, and get some
suggestions from developers.
But as i see, May be not good to detect compressor from libvirt
config, but create new stream functions that have in flags somewhere
compressor type.
So when data uploaded/downloaded stream Recv/Send functions able to
compress/decompress on the fly.
But i'm not understand some things:
1) user run volumedownload with offset (uncompressed size) and length.
But when user recieve data - resulted len < requested len. How to deal
with this?
2) how to display progress when downloading/uploading data? in case of
uncompressed size thing very simple (i know all size and transfered),
but in case of compressed data how to determine progress ?

Thanks!

-- 
Vasiliy Tolstov,
e-mail: v.tolstov at selfip.ru