More informative "attic create -v" output

[jborg]

As suggested by Christian Neukirchen on the mailing list it would be great if Attic would show more detailed progress during archive creation. Like if a file was modified or not and perhaps also the deduplicated size (or ratio).

http://librelist.com/browser//attic/2014/3/16/a-few-questions-on-attic/

Christian's suggestion (like duplicity)

A /tmp/addedfile
M /tmp/changedfile
D /tmp/deletedfile
(I guess "D" is not detected by Attic.)

Another suggestion from Petros:

Changed: /path/to/some/file [original size: 50KB, compressed size: 20KB,
unique data: 2KB]
New: /path/to/another/file [original size: 1MB, compressed size: 600KB,
unique data: 30KB]

Jonas' suggestion:

/tmp
/tmp/addedfile  (2kB, 3%)
/tmp/changedfile  (23MB, 25%)
/dev/zero

[Ernest0x]

I think that it should be stated what the values in the parenthesis actually mean. Otherwise, new users would have to guess or refer to documentation. The same applies to using symbols instead of full words for file changes, though the symbols may look better to the eye. That said, appearance and readability could be improved for the more verbose format I suggested by having a prefix of fixed width and right-aligned text, like this:

Directory: /tmp
  Changed: /tmp/changedfile (original size: 50KB, compressed size: 20KB, unique data: 2KB)
    Added: /tmp/addedfile (original size: 1MB, compressed size: 600KB, unique data: 30KB)
  Symlink: /tmp/somesymlink
     Pipe: /tmp/somefifo
Directory: /dev
   Device: /dev/zero

Also, to maintain UI consistency, I would suggest that the same terminology is used for both individual file changes (with --verbose) and summary results (with --stats).

[ThomasWaldmann]

See PR #224 (needs feedback).

Note: I did not want to compute too much statistical stuff. Keep it simple.