Support signatures of source files (enhancement)

[GoogleCodeExporter]

Here's the current scenario:

1) Create a base VM and export it to disk as base.xva
2) Upload it somewhere
3) Install some software and export that VM, new.xva
4) Run xdelta3 -e -s base.xva new.xva new.vcdiff
5) Upload new.vcdiff
6) Go back to #3 for any new software updates

The problem is that base.xva can be quite large. It would be good if I could 
instead pre-compute a signature file with the checksums of the blocks, and save 
that locally. Then I don't need base.xva any more to compute the diffs.

New scenario:

1) Create a base VM and export it to disk as base.xva
2) Run xdelta3 signature base.xva base.xva.signature
3) Upload both somewhere
4) Delete base.xva to save space
5) Install some software and export that VM, new.xva
6) Run xdelta3 -e -s base.xva.signature new.xva new.vcdiff
7) Upload new.vcdiff
8) Go back to #5 for any new software updates

Original issue reported on code.google.com by da...@coppit.org on 9 Sep 2014 at 3:25

[GoogleCodeExporter]

Oops. I just realized this is a dup of issue 185.

Original comment by da...@coppit.org on 9 Sep 2014 at 5:11

[GoogleCodeExporter]

Xdelta does not work this way -- it uses only a weak checksum and assumes it 
can access the original content for matching.

Original comment by josh.mac...@gmail.com on 12 Oct 2014 at 3:00

• Changed state: WillNotFix