Thursday, May 05, 2005

It's still hard to find time to write at the moment. Anne and I are getting married tomorrow, so hopefully I'll have a little more time next week.

In the meantime, we've had several public holidays recently (we get them all at one time of the year). Unfortunately I've only taken advantage of the most recent of them, which was last Monday.

Anyway, with the wedding tomorrow and a lot of work to get done, I won't be writing much today either. I just thought I'd better write something before I get too far out of the habit.

I did my confirmation last Friday. The internal web page with the administrative details of confirmation has been taken down, so it wasn't until the last moment that I discovered when the paper was due. It was sooner than I had thought, so I didn't have a lot of time for feedback on it. As a result, no one got back to me in time. It was frustrating, but at least the paper was accepted.

Again, with lack of time, I didn't get a lot of time to prepare for the presentation either. I'm normally good with presentations, so I was feeling a bit overconfident about it. But once I was in there I realised how out of practice and under prepared I was. Fortunately, confirmation is evaluated in relation to the quality expected of most students, so from that perspective I did well. All that matters is whether I was accepted or not, and I did that easily.

However, I was very disappointed with myself, as I can do a lot better. I've asked Bob for the opportunity to give several more presentations, to get some more practice.

I backed out some of the comparator changes, as I mentioned last time. However, I've kept them archived, as I still feel that they are more "correct". If I ever run into problems with the current method I'll have some code to fall back onto. This code is quite long, so I wouldn't want to write it again.

Debugging has gone slowly, with everything else I've been doing, but it's all looking good. The main problem I seem to have now is a need for a resolver that will also search along collection lists. I have to think about the consequences of this though, as this would remove duplicate entries. None of the use cases I have contain duplicates, but it would still be a problem in some circumstances. Maybe I should just document this as the required behaviour (which it is) and move on.

In my spare time (like I have any of that) I've also started work on another resolver. This time it's not related to my project, but I think it's going to be important...

Mac OS X.4 was supposed to arrive last Friday, but it didn't. If I'd realised it might be late (Apple guaranteed delivery on the release day) I wouldn't have pre-paid for it, and would have gone off to an Apple Centre to buy it instead. This is a toy I've been looking forward to. :-)

At least this gave me a chance to play with, and set up my new Neuston MC-500. Linux does not synchronize it's video output too well, so fast-action video scenes can tear a little. Also, MythTV hates sending output to the TV through my old MGA G400 card (I don't play games, so I haven't had a need to upgrade it). So now I have MythTV doing the recording, and the Neuston doing the playback. The user interface with the remote is easy for Anne to use, so she's been able to show Luc a lot of recorded "Wiggles". :-)

But I digress...

The real reason I've been waiting for OSX has been to use Spotlight. This is a hash-based index for meta-data of all the files on disk. For some time I've been thinking of implementing something like this for Linux or OSX, but now that Apple has done it for me I don't need to. :-) Longhorn will be doing something similar as well, so it should not be long before this becomes a common feature for modern file systems.

I was thinking about using Kowari (or a similar system written in C) to implement the filesystem index. Now that I don't have to, I've been thinking of inverting the whole thing, and using the filesystem index as a backend for Kowari. This just requires a resolver that wraps Apple's Spotlight interfaces. That's the resolver I've been writing.

For the moment, I've been using JNI to implement a set of Java classes which provide the meta-data interfaces from Apple's "Core Foundation". This has been a good way to learn Core Foundation. It's also good practice in JNI, as I'm trying to do everything "right". This means a lot of error checking, etc.

Eventually I expect to provide a set of metadata classes for Longhorn as well. However, I should see what functionality is provided there before I try to work out a common interface that will work across filesystems. In the long run, I'd like to have library that detects the OS, and automatically loads up the correct JNI library. I could even have a fallback class written in Java that returns basic meta data about files (filename, timestamp, owner, etc).

But at this stage I just have classes which work on Spotlight. Once I've wrapped them in a resolver I'll be adding them to Kowari.

If anyone is interested in this code, then just let me know. It's all being open-sourced, but I just haven't got around to publishing it yet. I'm been doing this Spotlight work in my own time (since I'm working on the rules engine in the day), and between the confirmation, the wedding, and last weekend's triathlon, I haven't had a lot of "spare time" at all. :-)

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