Re: GSoC 2010: "Integrated Web Client for git" proposal

[Jakub Narebski <jnareb@gmail.com>]

On Mon, Apr 19, 2010, Petr Baudis wrote:
> On Mon, Apr 19, 2010 at 12:43:22PM +0200, Jakub Narebski wrote:
>> On Sun, Apr 18, 2010 at 21:56 +0200, Petr Baudis wrote:

>>> If the project is a success, I wanted to use it for mob branch editing
>>> on repo.or.cz. It could also be used as open-source Gist alternative.
>> 
>> For that you would need editing file / editing contents action, but
>> this is explicitely excluded in current version of Pavan's proposal :-(
> 
> Is it? I see it only being omitted.

At the end, in the section which describes what would be not included
in the project, there was editing files excluded from project.

Which is a bit strange because you need some kind of web editor (even
if it is simply textarea) for the commit message if this "Web Client"
is to implement [git commit]...
 
>>> But it needs to be coded so that it does not require an actual checked
>>> out copy (which shouldn't be too much hassle).
>> 
>> It would require using 'git hash-object -t blob -w --stdin' (from body
>> submitted via POST from textarea) plus 'git update-index --cacheinfo'.
> 
> Yes. Not a whole lot of effort, seems to me. A downside is that you
> cannot use the working tree - index dichotomy, but life isn't perfect.

What do you mean here by "working tree - index dichotomy"?
 
>> There is however complication that you would need to do open2/open3
>> because git-hash-object would require bidirectional communication unless
>> you would use temporary file (command_bidi_pipe in Git.pm, untested).
> 
> I think even just going through a temporary file is fine for initial
> implementation.

It is not that difficult.  You can use IPC::Open2 (which is in core)
and IO::Handle (for easier coding; using IO::Handle is not strictly
necessary), like that:

  use IPC::Open2 qw(open2);
  use IO::Handle;

  ...

  my $pid = open2($out, $in, git_cmd(), 'hash-object', '-w', '--stdin');
  $in->printflush($cgi->param('textarea'))
     or die...;
  my $sha1 = $out->getline();
  chomp $sha1;

  close $out;
  waitpid $pid, 0;

Then you would need:

  system(git_cmd(), 'update-index', '--cacheinfo',
         '100644', $sha1, $pretend_path)
    or die...;

Not tested!
-- 
Jakub Narebski
Poland