I'm finally doing some serious optimisation of ikiwiki tonight. It had been feeling a bit slow.

So far with one optimisation (making it into a two-pass compiler) I've sped it up about 8x in some cases, though it's probably more like 2x-4x in the general case of rebuilding a wiki from scratch. Incremental builds are also sped up somewhat, though generally much less.

Another optimisation changes backlinks calculation from O(N^3) to O(N^2) on the number of pages in the wiki. Of course N^2 still isn't very good, but this is still a serious improvement. Especially when you have thousands of pages.

Rebuilding my personal wiki with these optimisations, it builds 9 times faster than before, now taking just 1 minute. Ikiwiki's own wiki rebuilds in 7 seconds instead of 34.

Stunning!