I'm David Llewellyn-Jones and this is my homepage. I'm a software engineer at Jolla, who's also interested in programming, security, privacy and graphics. I occasionally crave adventure and a good thunderstorm. You might be interested in my software, my research or my random musings.

Want to know more about me? Here's a personality sketch written by a psychologist when I was in school.

“David is of high intelligence, although lacking in true creativity. He has a need for order and clarity, and for neat and tidy systems in which every detail finds its appropriate place. His writing is rather dull and mechanical, occasionally enlivened by somewhat corny puns and by flashes of imagination of the sci-fi type. He has a strong drive for competence. He seems to have little feel and little sympathy for other people and does not enjoy interacting with others. Self-centered, he nonetheless has a deep moral sense.”

Wow. Harsh. But disturbingly accurate.

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27 Mar 2021 : Waste data dump #
I've just uploaded the latest set of my waste data measurements. The most notable change this fortnight is that iron suddenly died. It caused me significant grief: I took it to an electrical repair store and was essentially told that it would be impossible to get it repaired (too cheap, no available parts) either by them or anywhere else. Eventually I resigned myself and bought a new one, returning the broken iron for recycling. It adds a whopping 805g to my general waste. But it raises broader issues. When I moved to Finland I essentially bought an entirely new life: new furniture, new appliances, new utensils. In some sense, my low waste output has been riding on that wave since then. Now as things start to break and decay, I'm going to begin having to dispose of some potentially heavy items. If my bed breaks, for example, that could double my annual output. That's one of the reasons I've enjoyed such low levels of waste output for the last two years. Maybe this signals an end to that. On a more practical level, I'm wondering if I should be distinguishing these larger items from my other general waste. I've decided against: it may be unpleasant to have to include the weight of these large items in my statistics, but it's a reality nonetheless that they contribute to my impact on the environment. I may yet decide to separate them out in future given the means of recycling is different than for other items, but right now I think it's fair to include my iron as part of my general waste. The good news for this fortnight at least is that an iron isn't as heavy as a bed, so my daily average of 225.15g/day is still below my 250g/day target.
14 Mar 2021 : Waste data dump #
The first waste data dump of the year. It's a bit of a strange one, since I've been out of the country since mid-December, a fact that's apparent in the figures and on the graph. My average of 21.34g/day is therefore pretty much irrelevant, but things should get back to a more normal situation with the next data dump. I've not yet posted a summary of my 2020 waste output, but it's on my list of tasks, so expect it soon.
16 Feb 2021 : Contrac 0.7.7 released #
A new version of Contrac is out, to coincide with the release of Sailfish OS 4.0.1 (since it needed an update for that anyway). This latest version fixes various issues, including the counters getting reset on unclean shutdown of the daemon, and you can also now (finally!) have diagnosis keys automatically download each day. Special note goes to Oskar Roesler, who contributed a bunch of great changes to the code, not least making the entire project more developer-friendly. The code is on github and binaries are on OpenRepos.
31 Jan 2021 : Contrac 0.7.6 released #
The latest version of Contrac is now up on OpenRepos and github. For some reason there was an interruption in the hourly diagnosis key archives being released and users noticed failed downloads. The hourly downloads are now working again, but since the daily archives worked throughout, I've switched the app to using those instead. Another nice improvement is that the download region can also now be chosen, so the Europe-wide keys can be requested instead of those just from Germany.
6 Jan 2021 : The lights come down #
It's epiphany and that means time to remove the decorations from the site. As it happens, we'd already moved on from Christmas snow to New Year fireworks. Now we're back to bog-standard-bokeh. As we plunge through the gloomy winter months (I actually like a bit of gloom), I reflect that the next scheduled site-styling isn't until Halloween. That's rather a long way away. I should think of some other things to celebrate in between and if you get bored of bokeh, don't forget you can always tweak the style yourself.