progress callbacks

[Marcus Brinkmann]

Hi,

while Miguel and me worked on GPA/GPGME integration, Miguel pointed out to me
that for operations on long files it would be useful to have progress status
messages from GnuGP.  Things like encrypting very large files can take a
long time, sufficiently long for people to wonder about what's happening.

Currently, GnuPG only emits progress stati for key generation.

There are a couple of questions if we want to make progress status messages
work for other operations.

1. How can GnuPG determine the size of the file it operates on?  For normal
   files, this is easy enough.  If it works on a pipe, or another object of
   undetermined size, it could emit a progress based on the amount of data
   already processed.  In addition, it would be useful if an option could be
   provided which can be used to set the data length that can be expected over
   the pipe, so that programs like GPGME which provide memory backed data
   objects would not have to deal with the absolute -> percentage conversion
   themselves.

2. If the gpg-agent is used, the responsibility to emit progress status
   messages for long decryption or signing operations would have to be in
   gpg-agent, and forwarded by gpg.

Is that about correct?  If yes, would such a feature be ok with the GnuPG
maintainers?  Would it be difficult to implement?

Thanks,
Marcus

-- 
`Rhubarb is no Egyptian god.' GNU      http://www.gnu.org    marcus at gnu.org
Marcus Brinkmann              The Hurd http://www.gnu.org/software/hurd/
Marcus.Brinkmann at ruhr-uni-bochum.de
http://www.marcus-brinkmann.de/