I used what little free time I had over the holidays to catch up on the recent developments in source control management systems, which have been quite interesting to follow. Especially the arrival of Distributed Version Control Systems has caused quite a buzz in the software development industry.
Somehow Eclipse as a whole totally missed the SVN boat. Only in the last year has there been any uptake of Subversion within the Eclipse Foundation itself. And although there are two separate plugins (and by my count at least 3 different adapter libraries) it still doesn’t feel quite as solid as the CVS counterpart. But the writing is on the wall: CVS does not fulfill all the needs we expect from a contemporary source code management system. And while I have been a long-time fan of Subversion (atomic-commits and rename tracking, yay!) I still feel that maybe the time of centralized source control is over, especially in an open source environment. Doug Schaefer seems to agree. Distributed source control makes it much easier for potential contributors to get started. Experimental and “investigative” branches are easier to manage, and things like feature branches are more easily merged again. While it’s not all roses either (partial checkouts and IP-taints anyone?), but it does make the the development process quite a bit better. And isn’t that one of the main goals of the Eclipse Foundation?
So over the holiday I checked out (quite literally) the latest egit sources and played around with it a little. I must say that I came away quite impressed. Although there are still some features missing, the core looks very solid and usable.
Because the source for egit is openly available, it was very easy for me to “grok” the innards of the git system. My C is getting a little rusty these days, so a Java implementation made a much better reading experience for me. Debugging and Ctrl-clicking as well for that matter. With the core jgit library in hand, I even tried to implement a versioned POJO persistence store, but that’s a story for another time. What struck me most about git was the raw and brutal simplicity and the resulting elegance of its design. Believe it or not, but git only knows four different types of objects. Java’s “hello world” uses about that many! Another neat thing is the hash value that is calculated for virtually everything you do. When I first readabout this feature, I was quite skeptical to be honest: For starters, I don’t want to type 40 letter strings anytime I want to reference a revision and secondly, what about collisions? Well I worked out the math on that one, and what it comes down to is this: by the time I will create my first collision I will have been struck by lightning three times over and have survived the sun going supernova. And as for typing in those hashes, well you need it less than you would think and even then you usually only need the first few letters to make it unambiguous.
So kudos to the egit team for the great and continued work on this project. There even is an egit project proposal up. Although git support was postponed in the last board meeting, I still think this a step in the right direction and I’m looking forward to future developments.