Re: Google Summer of Code 2009: GIT

Hi all,

Sorry for replying so late as I was busy in my college's mid-semester exams :-|

On Thu, Mar 19, 2009 at 4:46 AM, Johannes Schindelin
[off-list ref] wrote:

Hi,

On Fri, 13 Mar 2009, saurabh gupta wrote:

quoted

On Fri, Mar 13, 2009 at 1:29 AM,  [off-list ref] wrote:

quoted

On Fri, 13 Mar 2009, saurabh gupta wrote:

quoted

Very well described, David. I agree with you and providing these
merge options to the user, merge drivers can do the work and mark the
conflicts according to the option. The work to do is to modify the
merge driver. I think in this way, even people who have only a
terminal can also gain from it. They can choose the apt option to see
the conflict markers in their way. So, the aim is to make merge
driver configurable and create the merged/conflicted file according
to the options.

for the GSOC I suspect that the right thing to do is the define one or
more merge drivers to create, and list what applications are going to
be used for testing these merges.

you and the mentor can decide what is a reasonable amount of work.

I will very glad to hear about this thing from the mentor (Johannes
Schindelin, according to wiki). I will try to plan out the things in a
proper way to carry out this project if I get a chance to work on this
for GSoC 2009.

Well, now that we have been accepted as an organization, we can move
forward with this idea!

Congrats for getting accepted in GSoC 2009.

My main concern is that we define early on what should be the user
interface, preferably with a quick sketch.

The technical details, we can hash them out later, I have no doubt that
with the help of the complete Git community, we can overcome almost every
problem handling XML data or some such.

quoted

quoted

it may be just doing an XML merge driver is a summer's worth of work,
or it may be that it's not really enough and you should try to do
another one or two.

it also may be that there is a lot of overlap between different merge
drivers, and once you have the XML driver the others become fairly
trivial to do. (I'm thinking the config file examples I posted earlier
in the thread)

with the options given to the user, one can handle the config files
also where order doesn't matter and also the whitespaces problem can
also be handled in the similar way.

In my humble opinion, we should focus on the data types we want to be
able to support at the end of the summer first.

For example, if we decide that OOXML is a must (as it is a proper
standard, and many people will benefit from it), we will most likely end
up in having to write a merge _driver_ (to handle those .zip files), _and_
a merge _helper_, although we can avoid writing our own GUI, as we can
create an OOXML that has its own version of conflict markers.

Well, for ODF type document, we can write a merge driver which will
change the xml file in an appropriate way that OO can understand it
and the user can see the merge result/conflict in a comfortable way.
As described by Junio, in this case, a dedicated merge helper is not
needed as OO can parse the markers made by merge-driver and provide
the user to resolve the conflict and register the changes to index.

If we decide that SVG is something we want to support by the end of the
summer, then we can probably avoid writing a merge _driver_, as plain text
is handled reasonably well in Git.  OTOH it could turn out that there are
_real_ conflicts in overlapping tag ids, and it would still be easier to
write a merge driver, too.

IOW the details are not as important as

- knowing what data types we want to support _at the least_, and what data
 types we keep for the free skate,

As of now, how about going for XML files. For this summer, we can go
for XML files and latex files can be handled later.

- a clear picture of the user interface we want to be able to provide,

In my opinion, we have following things to do:

=> while merging an ODF document, merge-driver will merge the file at
file level. If changes don't overlap, then it returns the result with
a success. For example, if the file is changed only on one side, then
the driver will simply add the new content.

=> If conflicts appear, then the merge driver will put the markers in
an appropriate manner which the end-user application (e.g. open
office) can understand and show the user. For example, the XML file of
that ODF document will be modified and OO can show it  to user in its
way. We will have to study about the OO style of version marking.
Another method is to implement the marker style in our own way. For
example, to show any marker, the XML file is modified so that user can
see markers like ">>>> " or "====" in openoffice....In this case, we
will have to just change the xml content in this way.

- a timeline (weekly milestones should be fine, I guess) what should be
 achieved when, and

Timeline can be decided once we reach some conclusion and the work
which needs to be done become clear to us.

- being flexible in how to support that (IOW if a merge driver appears
 unnecessary first, but necessary later, we should be able to fit that
 into both the design and the timeline).

How does that sound?

Ciao,
Dscho

-- 
Saurabh Gupta
Senior,
NSIT,New Delhi, India