Understandability of git, mercurial, bazaar source code bases

Question

I'd like to read the source code of one of the popular revision control tools to learn how revision control works. I'd like to read the one that is most readable.

I don't know of an objective, quantitative measure of this, so in the spirit of the WTFs/min comic, I'd like to ask those who have read the source codes of these tools, how many WTFs/min do you estimate each project has?

Answer 1

If you read C well (and some Perl and bash too), adymitruk is right. Git is a good choice.

However, if you're more comfortable with Python, read Mercurial's source. Many of the WTFs/min are going to come from your familiarity with the language and style that the DVCS is written in. Git is written in C, Perl, and Bourne shell, Mercurial is Python (with a bit of C IIRC), and Bzr is written in Python, Pyrex, and C.

You'll also want to take into account what your tool of choice is. If you use Git, you'll understand what each file is implementing. Likewise with Mercurial or Bzr.

Basically, when choosing what tool or language to use (or study), a good axiom is this: go with what you know. You're trying to learn how to implement a DVCS, not how to use a particular system or language :)

Answer 2

What can be much better than Python in the context of understandable and beautiful code?

Go for Mercurial. I have done it and It's absolutely lovely :)