A couple days ago, I set to work on what seemed like a fairly straightforward project: I wanted to build a reasonably fast factorization program in plain C. I didn't need it to be able to factor massive numbers, I just wanted to create it as an exercise. This seemingly basic concept led me into the strange world of number theory, a land I had never been formally introduced to, and ultimately resulted in me gaining quite a bit of knowledge.

I've written a lot in the past about the various systems that have powered this blog. It's gotten to the point now where the most popular topic on this site seems to be the site itself. However, I've made a major change to how it all works, and I think that it is important enough this time to justify yet another meta-post.

Mac OS X Lion introduced a new low-level system for managing relationships between physical disks and file systems. Currently, the primary use of CoreStorage is to enable FileVault 2, Lion's full disk encryption system. CoreStorage includes low-level support for AES-XTS encryption, allowing a filesystem to be used on an encrypted volume without any modifications of the filesystem software. Therefor, any applications running on an encrypted volume don't need to change any of their behaviors to support the new FileVault features.

Singletons are special classes which have only one valid instance in an entire application or context. They are similar to global variables in that anything that tries to access them will always find itself sending messages to the same actual object as anything else. Singletons are very common in apps that utilize Objective-C. Apple's often-used singletons include NSFileManager and NSUserDefaults.

Apple just released version 10.6.5 of OS X, and it updated Mail.app and the corresponding Message.framework. This means that if you are a user of the SpamSieve plugin for spam filtering in Mail.app, it will disable the bundle upon launch and tell you that it needs to be updated. Fortunately, the fix for this is simple: