Re: Opera release Git-splitter, a sub-modularizing tool for Git

["Yngve Nysaeter Pettersen" <yngve@opera.com>]

On Fri, 21 Dec 2012 14:49:26 +0100, Michael J Gruber  
<git@drmicha.warpmail.net> wrote:

> Yngve Nysaeter Pettersen venit, vidit, dixit 21.12.2012 13:43:
>> Hi,
>>
>> On Fri, 21 Dec 2012 13:23:46 +0100, Michael J Gruber
>> <git@drmicha.warpmail.net> wrote:
>>
>>> Yngve N. Pettersen (Developer Opera Software ASA) venit, vidit, dixit
>>> 18.12.2012 15:51:
>>>> Hello all,
>>>>
>>>> Today Opera Software released the "Git-splitter", a small tool for
>>>> sub-modularizing code in a git repo, with complete commit history,  
>>>> under
>>>> the Apache 2.0 license.
>>>>
>>>> It's functionality is similar to "git-subtree", but also include a
>>>> command
>>>> for reversing the process.
>>>
>>> Is there something keeping you technically from adding a join command  
>>> to
>>> git-subtree?
>>
>> Probably not, but within the process I was working I did not want to  
>> merge
>> the branch with the recreated history for that path into the existing
>> codebase (I don't like duplicate histories) so I used rebasing to move  
>> the
>> new commits over, instead, and therefore did not need a join command.
>>
>> Feel free to add a join command, if you want one.
>
> Im sorry, but that was a total misunderstanding. You said git-splitter
> is like git-subtree but adds a command for reversing the process. My
> question was: What kept you from adding that to git-subtree (rather than
> redoing stiff that git-subtree does)?
>
> I just assumed that reversing the process of splitting must be joining.
>
> It may very well be that git-splitter does things differently, i.e. that
> there are more differences than just added functionality (compared to
> git-subtree), but that is not clear from the announcement.


The split command will create a new repository for all files foo in a  
folder (path/foo) and their commit history.

The replant command reverses that process, re-adding the path prefix for  
each file. It may be possible to extend that process into one that  
automatically reintegrates the new commits in the original history, but I  
never had time to complete that work.

I did originally add the "replant" functionality into my version of the  
git-subtree script, but given the number of commits in the original  
repository, git-subtree turned out to be inefficient, due to the use of  
temporary files (tens of thousands of files IIRC).

Those problems led to my development of git-splitter in Python (bypassing  
the problem of temporary files), but just including the functionality I  
needed, join was not one of those functions.

>>>> The code is hosted on GitHub:
>>>> <https://github.com/operasoftware/git-splitter>
>>>>
>>>> We have announced the release as part of another announcement of
>>>> released
>>>> code at the Opera Security Group home page:
>>>> <http://my.opera.com/securitygroup/blog/2012/12/18/tls-prober-source-released-under-apache-2-0-license>
>>>>
>>
>>


-- 
Sincerely,
Yngve N. Pettersen
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Opera Software ASA                   http://www.opera.com/
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