The last 5 years or so have provided a tremendous amount of hype about the capabilities of JavaScript. I think it really kicked off when Google announced their Chrome web browser in September, 2008 along with its V8 JS engine. This seemed to spark an arms race in JS engine performance along with much hyperbole that eventually all software could, would, and/or should be written in straight JavaScript for maximum portability and future-proofing, perhaps aided by Emscripten, a tool which magically transforms C and C++ code into JS. The latest round of rhetoric comes courtesy of something called asm.js which purports to narrow the gap between JS and native code performance.

I haven’t been a believer, to express it charitably. But I wanted to be certain, so I set out to devise my own experiment to test modern JS performance.

Up Front Summary
I was extremely surprised that my experiment demonstrated JS performance FAR beyond my expectations. There might be something to these claims of magnficent JS speed in numerical applications. Basically, here were my thoughts during the process:

• There’s no way that JavaScript can come anywhere close to C performance for a numerically intensive operation; a simple experiment should demonstrate this.
• Here’s a straightforward C program to perform a simple yet numerically intensive operation.
• Let’s compile the C program on gcc and get some baseline performance numbers.
• Let’s use Emscripten to convert the C program to JavaScript and run it under Chrome.
• Ha! Pitiful JS performance, just as I expected!
• Try the same program under Firefox, since Firefox is supposed to have some crazy optimization for asm.js code, allegedly emitted by Emscripten.
• LOL! Firefox performs even worse than Chrome!
• Wait a minute… the Emscripten documentation mentioned using optimization levels for generating higher performance JS, so try ‘-O1’.
• Umm… wow: Chrome’s performance increased dramatically! What about Firefox? Not only is Firefox faster than Chrome, it’s faster than the gcc-generated code!
• As my faith in C is suddenly shaken to its core, I remembered to compile the gcc version with an explicit optimization level. The native C version pulled ahead of Firefox again, but the Firefox code is still close.
• Aha! This is just desktop– but what about mobile? One of the leading arguments for converting everything to pure JavaScript is that such programs will magically run perfectly in mobile browsers. So I wager that this is where the experiment will fall over.
• I proceed to try the same converted program on a variety of mobile platforms.
• The mobile platforms perform rather admirably as well.
• I am surprised.

The Experiment
I wanted to run a simple yet numerically-intensive and relevant benchmark, and something I am familiar with. I settled on JPEG image decoding. Again, I wanted to keep this simple, ideally in a single file because I didn’t know how hard it might be to deal with Emscripten. I found NanoJPEG, which is a straightforward JPEG decoder contained in a single C file.
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What do I do? What I do? This library book is 42 years overdue!
I admit that it’s mine, yet I can’t pay the fine,
Should I turn it in or should I hide it again?
What do I do? What do I do?

I internalized the forgoing paean to the perils of procrastination by Shel Silverstein in my formative years. It’s probably why I’ve never paid a single cent in late fees in my entire life.

However, I have been woefully negligent as the steward of the MediaWiki software that drives the world famous MultimediaWiki, the internet’s central repository of obscure technical knowledge related to multimedia. It is currently running of version 1.6 software. The latest version is 1.22.

The Story So Far
According to my records, I first set up the wiki late in 2005. I don’t know which MediaWiki release I was using at the time. I probably conducted a few upgrades in the early days, but that went by the wayside perhaps in 2007. My web host stopped allowing shell access and the MediaWiki upgrade process pretty much requires running a PHP script from a command line. Upgrade time came around and I put off the project. Weeks turned into months turned into years until, according to some notes, the wiki abruptly stopped working in July, 2011. Suddenly, there were PHP errors about “Namespace” being a reserved word.

While I finally laid out a plan to upgrade the wiki after all these years, I eventually found that the problem had been caused when my webhost upgraded from PHP 5.2 -> 5.3. I also learned of a small number of code changes that caused the problem to go away, thus kicking the can down the road once more.

Then a new problem showed up last week. I think it might be related to a new version of PHP again. This time, a few other things on my site broke, and I learned that my webhost now allows me to select a PHP version to use (with the version then set to “auto”, which didn’t yield much information). Rolling back to an earlier version of PHP might have solved the problem easily.

But NO! I made the determination that this goes no further. I want this wiki upgraded.

The Arduous Upgrade Path
There are 2 general upgrade paths I can think of:
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