February 4th, 2010
While I spend most of my time in front of a keyboard and monitor, my wife Eva Funderburgh spends her time sculpting amazing, imaginary ceramic creatures. Her beasts are assembled out of different clays and wood-fired. About a year ago she enlisted my help in building a new type of beast with egg-shaped domes on its back. The idea was to have the domes glow and pulse with an organic, bioluminescent light. (Note: This was way before we’d seen Avatar!) Eva had already built and fired the beast a few months earlier, using thin shells of translucent Southern Ice porcelain for the domes. She left a few of the domes unattached so we could get lights inside after the firing.
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January 31st, 2010
As an emacs user, I’ve found iswitchb (interactive-switch-buffers) to be a huge time saver. Basically, to switch files (buffers) you enter a typically byzantine key combination and then type to search through your open files – as less and less files match your search, the choices narrow down, and you can choose between them. This ends up being way faster than switching with a mouse even in tabbed editors, and I’ve managed to set up a similar thing in Eclipse/Aptana. But until recently I didn’t have the same functionality for switching tabs in Firefox.
The good news is that Firefox 3.6 has this feature built in, though it takes a bit of work to enable. Apparently they’ve been trying to get this feature into Firefox since 3.0, but there’s been a lot of different opinions, so even though they finally shipped it with 3.6, it isn’t on by default. You can turn it on by going to about:config (just type that right into your address bar), then searching for “ctrlTab”. Double-click browser.ctrlTab.previews to turn it to “true”. Now, when you hit Ctrl-Tab, you’ll get a tab switcher that looks a bit like the default Windows Alt-Tab window switcher (though with a much lighter glass effect that honestly looks pretty bad compared to Windows’ Alt-Tab). On other platforms you’ll get a similarly system-integrated look. Unfortunately this popup isn’t exactly what we’re looking for – it doesn’t show all your tabs and you can’t search! However, you can navigate down to “show all X tabs” at the bottom and you get a search box and a list of every tab. That’s a real pain to do every time you want to switch tabs, though. Fortunately, there’s a solution. Instead of hitting Ctrl-Tab, use Ctrl-Shift-Tab, and you’ll start out right at the big tab switcher with search. From here you can type to narrow down your selection and hit Enter to choose your tab. I wish there was a preference to make this full search show up when you hit Ctrl-Tab, but it doesn’t look like there is.
Switching between tabs (man, that glass effect is a mess)
Visual issues aside, I wish every program with a tab-oriented UI had a feature like this to make their app faster to use for keyboard users. While we’re at it, Windows and OSX should add search to their built-in window switchers – it could really help when I have a lot of windows open and don’t want to reach for the mouse.
Note: There are a couple extensions for Google Chrome that theoretically give a similar searchable tab switcher, but of the few I tried, none of them could appear with a keyboard shortcut – you had to click an icon on the toolbar, which seems to defeat the point. Apparently the Chrome Extensions API has known problems with keyboard shortcuts, so maybe things will get better soon.
January 30th, 2010
Ruby on Rails has some great caching support built right in, but it’s most useful when you have MemCacheD or DRb around to serve as a cache store. I don’t have access to those everywhere – Dreamhost and other shared hosting providers often prohibit running your own MemCacheD. There’s a default memory store, but it won’t share cached info between Rails server processes. That leaves the file store, which just writes cached objects to a file that gets shared between all your Rails processes on the same box. The main problem with the file store is that it doesn’t support time-based expiration – you have to set up a cron job to sweep out the cache files every once in a while to invalidate your cache.
To get around this, I wrote a tiny, obvious little module that gives a simple syntax for caching objects with the file store. The trick is that it stores the insert time whenever it caches a new object, and compares it with the current time every time it looks it up. If the cached object is too old (or the cache is empty), it throws it away and executes the provided block and caches the new value.
Be sure to use the same expiration whenever you fetch the same object, or things will expire differently depending on where they’re accessed. You can also do a bit of customization for more complex cache invalidations – I have a version of fetch that caches objects within one calendar day and recalculates them only when the date is different. I suppose I could made fetch take an optional Proc to control the caching strategy, but I didn’t really need that much customization. Anyway, this isn’t exactly brilliant new code, but it has made caching objects from my smaller Rails apps a bit easier.
January 23rd, 2010
In my previous post, “Investigating JavaScript Array Iteration Performance“, I found that among a selection of different array iteration methods, jQuery’s each function was the slowest. It’s worth mentioning again that these investigations are pretty academic – array iteration and looping speed is unlikely to be the source of performance problems compared to actual program logic, DOM manipulation, string manipulation, etc. I just found it interesting to poke into how things work in different browsers. That said, with the recent release of jQuery 1.4 emphasizing performance so much, I wanted to see what if anything could be done to speed up each (which is used inside jQuery all over the place), and whether it would made much of a difference.
Again, the details are after the jump.
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December 13th, 2009
The other day I was working on some JavaScript code that needed to iterate over huge arrays. I was using jQuery’s $.each function just because it was simple, but I had heard from a bunch of articles on the web that $.each was much slower than a normal for loop. That certainly made sense, and switching to a normal for loop sped up my code quite a bit in the sections that dealt with large arrays.
I’d also recently seen an article on Ajaxian about a new library, Underscore.js that claimed to include, among other nice Ruby-style functional building blocks, an each function that was powered by the JavaScript 1.5 Array.forEach when it was available (and degrading for IE). I wondered how much faster that was than jQuery’s $.each, and that got me to thinking about all the different ways to iterate over an array in JavaScript, so I decided to test them out and compare them in different browsers.
This gets pretty long so the rest is after the jump.
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