I may be 7 years late or so – but until last week, I didn’t realize that didSet property observers would fire when the observed property hasn’t actually changed. All you need is a mutating func that doesn’t even need to mutate. This can be illustrated with a simple piece of code:
I was profiling performance bottlenecks in the The Archive and noticed that no matter how much highlighting functionality I removed/commented-out, the apparent slowness was all due to … Touch Bar API?! I have been “pruning” the Touch Bar related calls from the profiling stack to focus on what I though would be the real bottlenecks. But, as often, it turns out this was stupid and the instruments did point out the true problem. Something indeed was causing trouble here, it turned out.
I code on a late 2011 Mac Mini with 8 GB RAM and a 256 GB SSD. This machine is a ton faster than my old MacBook Air was. Compilation still takes time, but it seems that iRamDisk helps a bit.
Lately I wondered if I could cut down the 30s compilation time (3mins with a clean build folder) if I had a Mac Pro, or MacBook Pro, or iMac, or whatever next tier device. Faster cores, more cores, doesn’t matter. But buying a Mac for $3k is out of question at the moment. So I’ve been looking for other tricks.
The only thing that’s faster than a SSD is RAM. That’s when I found the app iRamDisk. It offers an option to move the derived data folder to a virtual disk in RAM. It seems I can reduce the clean build time from 3mins to 2mins with that. Xcode needs about 1.5GB derived data for the Word Counter – at least that’s how big I had to make the RAM disk to not get filled quickly. The overall memory pressure is a bit higher, the Mac is using swap more, but compilation becomes faster at last.
There’s a downside, too: after every reboot the RAM disk is empty, so Xcode has to index the project again and compile fresh at least once a day. Depending on your usage this can be annoying or not be a problem at all.
You can download a trial from the website or buy it for $19.99 on the Mac App Store.