kai_mactane

This is largely a bug-fix release. Tom Clift, of PaperCut print management software, kindly informed me of a few installation issues that my own tests didn’t find. The profusion of configuration options in PHP can make testing everything on a single server quite difficult.

This would be a good time for me to mention that I have the utmost respect for QA people. They deal with all sorts of minutiae that I am really glad not to have to handle, and I’m really glad they’re around. That said, I am not a QA person… and so I occasionally miss the sorts of stuff they’d catch.

1. It turns out Hummingbird depends on the CLI version of PHP, and the CGI version will not suffice. This requirement is now listed in the appropriate section of the Hummingbird page.
2. Not all PHP installations have output buffering turned on by default. The latest version of Hummingbird takes account for this.
3. Various problems that can occur with the data cache file are also now reported more gracefully.

Again, my thanks to Tom Clift for some very useful patches!

You can get the latest version of Hummingbird from the Hummingbird page on my site.

Originally published at Coyote Tracks. You can comment here or there.

I’ve always questioned the wisdom of building a startup company based around someone else’s platform, like Facebook games or Gmail inbox add-ons. You’re totally at the mercy of the other company. (Many people have found out how silly it was to go up against Microsoft or Apple in just the same way.)

And yet, here I am with Hummingbird, which is totally dependent on Twitter’s bandwidth. (In my own defense, I can only point out that: a) I wrote it because I needed the functionality; and b) I’m not building a money-making company around Hummingbird. I’m just giving it away.)

In the past couple of weeks, I’ve noticed that Twitter can sometimes take an astonishingly long time to provide an update. Hummingbird works by requesting URLs like http://twitter.com/statuses/user_timeline/kmactane.xml?count=25, and (up until now) it worked on the assumption that Twitter couldn’t possibly take longer than 10 or 15 seconds to respond to such a request.

That turns out not to be the case.

In fact, my recent tests have shown that Twitter can sometimes take over 5 full minutes to finish responding to such a request. This is a problem, because the default installation of Hummingbird tries to update its cached data once every 5 minutes. And since I assumed the request would be fulfilled in, at most, 10% of that time, I didn’t bother building in any concurrency checking.

I’ve just completely reorganized most of Hummingbird’s architecture. The interface that a blog owner sees (in the sense of the configuration variables in hummingbird.php, and the calling syntax for blog pages and cron jobs) is still the same. However, all of the code for retrieving data from Twitter has been spun off into a new hummingbird-cache.php file, which can be launched into the background by the rest of Hummingbird, so that it can patiently take as long as it needs to in order to update the blog’s tweets cache.

The Major Change This Causes

In Hummingbird’s previous incarnations, it would freshen an out-of-date cache before displaying it. The assumption was that every once in a while, someone might have to wait a few more seconds before seeing your blog page. However, everyone would always see an up-to-date record of your tweets. (Where “up-to-date” means “no more than 5 minutes old, absolute tops”. If you tweet so relentlessly that that’s a problem, you probably don’t have enough time to keep up your blog…)

Now that we know that Twitter can take over 5 minutes to give you the data needed to freshen your tweets cache, that design is not acceptable. Instead, Hummingbird is now committed to showing the contents of your tweets cache as quickly as possible, and only then does it fork the cache-update process into the background.

This means that, if you’re not using cron or some other automatic job-scheduling facility to run Hummingbird every 5 minutes, visitors who arrive at your blog after a period of inactivity will see an out-of-date, stale listing of your tweets.

If you have a cron job set to keep Hummingbird fresh, you’ll be fine. (A page view will also trigger an update, so if you get so much traffic that there’s never a 5-minute period during which your page doesn’t get hit, you’ll also be fine.)

Originally published at Coyote Tracks. You can comment here or there.

I’ve actually made some progress on coding projects this weekend. My Palm Prē “Magic 8 Ball” application now responds to the Prē’s accelerometer: if you rotate the Prē, the app stays right-side up (including readjusting the position of the backdrop image). Even cooler, you no longer have to tap a button to trigger the fortune; now you shake the phone instead. (Last Saturday night, a friend expected to be able to shake the phone and have it “shake the magic 8-Ball”. But that wasn’t actually possible for third-party devs like me at the time; the accelerometer support only arrived in the webOS 1.1.0 update, which came out on Thursday.)

I’ve also got a reasonably good script for installing, updating, and uninstalling homebrew apps for the Prē. Instead of the annoying, six-step process for installing homebrew apps on a rooted Prē, I just shell in and type ./homebrew.sh my 8ball, and the homebrew.sh script does it all for me. I need to publish that thing, now that I’ve got it working fairly well.

Additionally, my Japanese sentence generator, called “J-Babble”, now does proper plain past tenses (the -ta and -nakatta forms), which will make it more useful for me as a tool to keep me from backsliding when I’m busy. I’d link to that, but it’s not really a general-use tool yet. It’s more just for me. Maybe some day, I’ll give it the option for people to customize what vocabulary and grammatical forms they know, so it can just generate stuff they have a chance of understanding. For now, though, its use is just for me: when my life gets too busy for me to read my Japanese textbook and try to make new progress, I can at least bring up J-Babble once a day and get 25 randomly-generated, but grammatically correct and semantically sensible, sentences in Japanese. It’s just enough to keep the neural pathways from atrophying; it allows me to hold my place instead of losing ground.

(I’ve gotten some housework done, too, but this isn’t the place to talk about that.)

Originally published at Coyote Tracks. You can comment here or there.

My latest project is something I call “LJ Content Sieve”: a Greasemonkey script to filter out content on one’s Livejournal views based on nearly any attribute of a post or comment.

However, Livejournal is very customizable. It has 31 different “layouts”, each of which can then be further “themed” by application of CSS. This means that a user viewing a given journal, community, or single post, at a given time, may receive an HTML document containing any of 31 different DOM structures.

This means that finding a post’s author, or title, or even just a single post or comment, is not a straightforward process. I’ve set myself up a Ruby script that downloaded my “friends” view, a representative entry with lots of comments, and my own journal view, thus giving me a set of 93 fixtures that I can test against. The Ruby script also tweaked each fixture in the process of spooling it to my hard drive, by adding the proper calls to JSUnit files.

At the end of each document’s <head> element, there’s a call to jsUnitCore.js. Then, at the end of each <body>, I add a call to the lj-content-sieve.user.js script itself, as well as a set of test files that depends on which fixture this is. Every fixture gets an ljcs-global-tests.js call added to it — that file contains tests that should work anywhere, regardless of what sort of page you’re on.

Then all the “friends” page fixtures get an ljcs-friends-tests.js file, which tests operations that should happen on every friends page. For example, determining which entries need to be deleted. (In contrast, single-entry pages get ljcs-entry-tests.js, and the page from my own journal — which stands in for a view of a community — gets ljcs-self-tests.js.)

Finally, each fixture page gets a test file based on its layout: the “3 Column” layout gets ljcs-3 Column-tests.js, while “Cuteness Attack” gets ljcs-Cuteness Attack-tests.js. (Hey, I didn’t write or name the layouts; I just have to make sure LJCS works with all of ‘em.) These files will test that the actual DOM manipulations work properly.

Without test-driven development and automated testing to ensure that each layout and page-type is being handled properly, I don’t think this project would be manageable at all.

Originally published at Coyote Tracks. You can comment here or there.

My latest software project is now available… where “latest” means “the latest thing I’ve launched, even if I actually wrote it over a year ago.”

The story is simple: I was tired of seeing “failed password” messages from sshd cluttering up my logs. I was also annoyed at the constant flow of dictionary attacks, even if I knew they’d never get in. So I whipped up a quick Perl script that acted as some glue between Swatch and iptables, and which would also give me some amount of reporting and history on who and what it was blocking.

Then I posted about it in my online journal, and a friend said it sounded useful. So I started getting it ready for release as a package that anyone could use…

And promptly realized that doing a decent, professional job of it would take more time than I had available. Fast-forward to now, when I’m unemployed and can only spend so many hours per day job-hunting — the result is that the world gets more software!

Originally published at Coyote Tracks. You can comment here or there.