Archive for October, 2007

Some thoughts on git

October 8, 2007

As I mentioned in a previous post, we started using git for managing Tagua source code. There’s currently a lot of controversy in the topic of distributed versus centralized VCS’s, and I feel like expressing my own ideas, too. 🙂
I’m no git guru (yet), so please don’t get offended if I missed something in my criticism. I hope to generate a fruitful discussion, because I really think that the VCS is an important element in the development of an open source project.

Why git rules

  • It’s decentralized. I fully agree with Linus on this point: the decentralized model is superior, for various reasons I won’t talk about in detail here.
  • It’s simple. I don’t understand why people keep complaining about git being overly complicated. The object model is fairly straightforward, as soon as you stop thinking about revisions the cvs/svn way, and branching/merging is trivial.
  • The object model is very well designed, flexible and useful.

Why git sucks

Well, git has a number of minor (?) defects, like portability issues, impossibility of doing partial checkouts (actually I think this is a problem with all the decentralized VCS’s) and stuff like that, but let me concentrate on those issues which are fundamental to git as an open source project, and are unlikely to be addressed in the future:

  • It is written in (unreadable) C. I don’t want to start a flame war (really!), but browsing through git’s code is a painful experience. Huge .c files with tons of big functions with no apparent structure and almost no comment. Ubiquitous micro-management stuff for handling manually allocated buffers. In other words… a mess.
  • It (ab)uses the UNIX philosophy. Do one thing, and do it well. Yeah, of course it’s a great idea, but maybe they shouldn’t have taken it too literally. I mean, if we talk about modularity and reusable components, I’m all for it, but it doesn’t mean you have to make a different executable for each task (even low level ones that should be invisible to the end user) and chain them together via text pipes and bash scripts!
  • It’s not reusable by third party applications, at least not in any efficient/convenient way. If you want to build a higher-level abstraction over git (a so-called porcelain), you need to fork out every now and then to get input from git, and then parse its textual output. Yes, I know about libgit.a, but that’s not really usable as a library (half of git functions call exit on failure) and has no API documentation at all.

That said, I have to admit that most of its defects aren’t that important if you are just going to use it, and not develop it. However, using something you have problems inspecting and modifying feels a bit like using a closed source product…