Solipsism Gradient

We had a nice short vacation visiting friends in Campanha, in the interior of Minas Gerais, Brazil. This is a small town, almost equidistant from Rio de Janeiro, São Paulo and Belo Horizonte, and the main focus is coffee and tangerine plantations. I’ve posted 10 selected photos and maybe later I’ll post some more.

Meanwhile, I’m glad to report that XRay II is slowly getting back up to speed. I lost over 2 months doing premature optimization… yes, I should have known better, but it snuck up on me in the form of caching.

The file system browser in XRay 1.x was an afterthought, tacked on because I needed to check out many files to test. I used Apple’s SimpleBrowser sample code nearly as-is and only cached each item’s 16×16 icon. It worked amazingly well, but it didn’t react properly to events like volume mounting/unmounting and folders changing.

One of the first things I did for XRay II was to make a better browser. I also decided to use the same backend data structures for the browser and for the object that represented the file item being XRayed. Of course this meant that the icon had to be cached in each object, as well as the name, the FSRef, the pointer to the parent folder… then I thought, I’d also better cache catalog info results, metadata, etc. etc., as all this would be needed later. Soon this object grew like topsy, adding all sorts of interesting information about the file item, each added lazily whenever requested…

…but it turns out that it became increasingly complex to keep this back-end cache synchronized with the actual file system. In fact, everything I did to optimize the cache internally made it more difficult to do external synchronization.

So, over the last month I basically started out from scratch with the back-end and, as soon as possible, implemented mount/unmount modifications, and folder change notifications (using M. Uli Kusterer‘s excellent UKKQueue). It turns out that it’s basically unproductive to cache anything but the name and icon… except, of course, while an item is being XRayed.

More as it happens…

Yes, we have progress. We’re taking a few days off, visiting friends, to commemorate… expect a post on the evils of premature optimization when we get back on Sunday.

Keola Donaghy wrote:

Hau’oli la hanau ia ‘oe!

Mahalo a nui loa!

Posted by Keola Donaghy:
Hau’oli la hanau ia ‘oe! (Hawaiian for ‘Happy Birthday’) My sister was born on 6/6/66, the number plus one!

Aloha,

Keola

So, it’s 6-6-6 in whatever date ordering you prefer, and this is supposedly the Number of the Beast. Or perhaps not. Do I care? Not really…

…it’s my birthday, however. This specific birthday is my 37th (in hexadecimal of course )and it’s a rare one, in that I’m not away on a trip. Last year my birthday present was a surprise, all right: I was at the WWDC keynote and listened to Steve Jobs announce the Mac-Intel switch. Later in the day I tripped on a San Francisco sidewalk and, fortunately, suffered no serious harm.

Hopefully, today will bring no serious surprises either way, and I’m looking forward to the positive ones that this year’s WWDC will bring. More details in a month or so…

You may have noticed that this site has been down for about a day… seems that I inadvertently let the domain expire, because the e-mail at the registrar was pointing to a defunct address. A previously unnoticed side-effect of my switching to DreamHost 18 months ago.

All is being sorted out now, and I apologize for any inconvenience.

So, my new Intel Mac mini is in and working. I bought the basic version; Core Solo at 1.5GHz, 512MB. It fits nicely under my iSub woofer. My iMac G5 controls it over Ethernet for remote debugging, and after some initial setup it doesn’t need mouse, keyboard or display.

I’ve already restarted debugging XRay II as a Universal Binary and universal versions of some other stuff will be out soon. Stay tuned…

Maybe of the month. This is from Tricks of the Trade, by Matthew Baldwin (aka the Defective Yeti), my emphasis added:

Every year there seems to be a technical whatsit that management recognizes as the sexy-cool new thing but doesn’t really understand. This year, for instance, a programmer can always tack the phrase “and I’m thinking of incorporating some XML functionality” onto a project summary to explain why he’l need an extra week, account for a missed deadline, or impress a superior. In this respect, the gap between software engineers and birthday clowns is almost negligible.

Worth a read.