After watching the
following video from Linus Torvalds about Git and testing several versioning tools this week again (see my
previous post about all kinds of source versioning tools like TFS, VSS and SourceGear Vault), I decided to give Git a chance. A friend of mine is using
Mercurial for his personal projects by utilizing
VisualHg (Mercurial plugin for VS). Mercurial is very similar to Git (from my limited knowledge), both are
distributed revision control
systems, which means no central server and everyone has a peer-to-peer
like repository. This this involves much more merges, branches and
applying patches to many different repository versions, merging is much
more important than in a centralized versioning tool.
The only reason I even watched the following presentation about Git (it
does not really tell you much) is because Linus was bashing CVS,
Subversion and many other versioning tools so hard. Some true points,
but some people really disliked his style. I found it entertaining.
You can find more documentation and a second video with more technical details about Git on the
Git Documentation website.
Well, all this Linux crap can be interesting from time to time, but as
long as there is no Visual Studio integration, I'm not really ever
going to use it anytime soon. However, there is a pretty successful
GitExtensions project,
which includes a very good integration to Windows, the Explorer and
even Visual Studio 2005/2008. After installing this and trying it out
for a while I kinda liked how nicely everything integrates into this
tool-set. You got Putty or OpenSSH, KDiff3, all the command line
support for playing around and you can even integrate all kinds of
other merge tools from Subversion, Perforce or whatever you like
better. Using GitExtensions is definitively easy and I can see why it
would make sense in a highly distributed open source project, everyone
can work on his own version and changes or fixes are around at
different places. It can also be used for small teams, then everyone
trusts each other and can merge all the changes whenever they want.
Merging changes is pretty cool tool, there is no need to do it twice,
once a programmer has merged something, it is merged for everyone else
once he pulls the new version.
However, I will not be using Git for neither my personal projects nor
at work. First of all I do mainly game development and while source
files are important, there are many other file formats to consider and
Git does not store them in any useful way. Because of the distributed
model it is impossible to lock a file, which means any changes to any
binary file can result in loss of work (or worse: more work since
someone has to merge changes yourself by hand). I have read many
discussions about this yesterday and some people are just retarded to
not see the point. If you just put text files into Git, everything is
fine, but once you have binary files that might change (why else would
you even put them into a versioning tool), you can get into trouble.
I'm not saying tools like Subversion are better, but at least they
allow you to lock files, to announce to everyone in the team: "This
file is mine now, please wait until I'm done changing it". With more
than 3 people and with lots of un-merge-able binary files this is
currently the only way this can work efficiently. Sure we could use two
or three different kind of versioning tools (one for programmers, one
for content, and even specialized ones for artists, which integrate
into their tools, etc.), but what is the fun in that?
But that is not really the reason not to use Git for source code.
Merging works pretty good for text files and since you can do a lot
more merges and be much more efficient, it sounds really useful. Git
even tracks if you remove code from one file and put it into another
file, you can still see history of it, etc. The reason I really dislike
Git and many many other versioning tools is simply: It is freaking
annoying to use all the time. You may only waste 10-30 seconds for
pulling, committing local changes, pushing them to somewhere else,
selecting files that have changed, adding comments, doing a quick
merge, etc. every time, but if you do that many times a day, a lot of
time is used just for that. You don't believe me? Just watch the 5
video tutorials on the
GitExtensions homepage, or check out the
Git Documentation, its samples and video tutorials.
It is not hard to use these tools, but it costs a lot of time
constantly doing all this crap. I fully understand that this might be
very necessary for huge projects like the Linux Kernel or useful and
wanted for distributed open source projects, but that is not what I
want to do all day and that is not what I want my employees doing.
I like if the source control system is completely hidden and ALL actions are done automatically by just working on the project!
- You open Visual Studio to start working? All files are updated automatically!
- You edit a file? The file is checked out to you automatically, others
can still work on it, if it is a merge-able file, but they know that
you are already sitting on it (maybe both of you are trying to do the
same thing, check work tasks again). But even if both people are
required to change a file, there is usually never a problem if you
check-in often!
- You are done working? Just close Visual Studio and everything gets
checked in automatically with a nice comment (required). Or just commit
in the middle of the day as much as you want if you think your changes
are important or needed right now.
Easy as that. We pretty much worked that way in the last project,
except we used Subversion and we had HUGE amount of files (20+ GB just
binary content). On some slower PCs it took 10+ Minutes just to get the
latest files. Then we had to manually Update everything every morning
just to start working. Committing happened when done working or when
something important was finished. But many commits just fail in a big
team because you have to update again since someone else changed
something. Then there is the worst part: Merging. Sometime it works
fine. "Luckily" we only had a few developers working on the same files
so most changes could be merged, but from time to time there were
really bad merging conflicts. Empty lines could not be merged, comments
were slightly different (e.g. we had to disable automatic comment and
header generation just because of constant conflicts of really
unimportant stuff) and if you were really unlucky some changes were
merged into a uncompilable mess. Even worse, sometimes you could
compile it, but some game logic was now buggy or some config files were
messed up. What I also hated about Subversion was the fact that I could
never get a complete version of the repository at home, there was
always some stupid checksum error, network corruption, https not
working, etc. problem that prevented some 200MB file not being
downloadable.
Again, it all depends on what you are working on. For example our
artists had not much problems with Subversion except for the long
update times, annoying cleanup and rare mess-ups that happened from
time to time. But then again they never versioned their work data, they
just checked in the final files to be used in the game. That alone eat
up many 100 GB on the repository. I bet the Linux kernel team is happy
with Git and many years ago when I was using VSS for myself I was also
happy with it (not much can go wrong if you are by yourself ^^). For
our next project I also don't want to have the whole repository of
everything on my small SSD, e.g. subversion needs everything twice, git
would even need more than that since every version is in the .git
directory plus the actual working files, fine for text files, not fine
for huge binary files. Only give me the stuff I really need for
working, not sure how to do this for content yet, but I bet there is
some crazy setting in Perforce to do it or we just write some tools
ourselves that only get stuff that is required for execution (unit
tests, editor, etc.).
Still had not really time to dig into any of the new tools I wrote about in the last weeks, but for now I will stay with
SourceGear Vault and its painless integration to VS. It looks like our Artists disliked
AlienBrain
(mostly because of the fact that it does not even support the recent
3DS Max 2010 version for over 6 months now), for that reason they are
currently evaluating Perforce, which is kinda hard to get used to at
first, but it is fast for binary files and it integrates nicely into
everything (Photoshop, 3DS Max, Maya, etc.) and we can also use it for
our project management (
OnTime) and hopefully integrate all that together with our build tool (whatever it might be, I'm currently liking
Cruise Control).
I don't think I like Perforce for us coders since the VS addin is very
old school and might cause some pain. The server setup was also not
easy at all, there are no admin tools on the server, you have try to
use the stupid P4V program or even better the command line to fix up
stuff. Currently we got a delay of 5s for all operations and we have no
idea where it is coming from. Probably have to set it up again and try
all kinds of settings to get it into a usable state. That is something
I really liked about SourceGear Vault, installation took 2 minutes and
everything was working out of the box. It might be a more simplistic
tool, but that's what I'm looking for :)
Useful links:
