I was deep in a performance optimization flow when I stumbled upon this part in a ruby-prof graph:

- 17.59% (73.45%) SomeTable::GeneratedAttributeMethods#some_attribute [30263106 calls, 44665545 total]
  - 15.24% (86.62%) ActiveRecord::AttributeMethods::Read#_read_attribute [30263106 calls, 49437307 total]
    - 11.82% (77.58%) ActiveModel::AttributeSet#fetch_value [30263106 calls, 49068748 total]
      - 5.44% (46.06%) ActiveModel::AttributeSet#[] [30263106 calls, 49303667 total]
        - 2.32% (42.58%) Hash#[] [30263106 calls, 72892138 total]
      - 2.05% (17.36%) ActiveModel::Attribute#value [30263106 calls, 49274896 total]

ActiveRecord stores attributes internally in a hash, which is more expensive than I expected.

Here’s a small bug we recently encountered in production. Occasionally, PDF generation jobs would fail, and the cause turned out to be a small oversight when designing database tables.

The PDF metadata is stored in a table, and the column for file size was defined as integer, also known as int4.

Since this data type is signed in Postgres, those 4 bytes only allow for files up to 2.1 GB (2 147 483 647 bytes). You might think, 2^31 bytes ought to be enough for everybody … except apparently for our PDFs.

A work buddy challenged me to a bit of Ruby code golfing.

Write a program to print all leap years from 1800 up to and including 2400.

The website he got the challenge from (https://code.golf/leap-years#ruby) has a neat feature: it can run your code and verify whether the output matches the expected result.

I’m usually not much of a code golfer, I generally prefer writing code that’s performant and readable rather than short and cryptic, but this turned out to be a fun little challenge and even somewhat educational.

I got myself a Raspberry Pi 5 with the intent of using it for Amiga emulation. There are several images floating around on the internet that bundle Amiga software.

The most comprehensive page I found is https://amigang.com/software-pii/ on AmigaNG.

I tried the Pimiga 4 image (PIMIGA_ARM.7z, md5sum 34ff61d2fd58e70b8109312b1a9202a9) but it turned out that the bundled kernel is too old for this board. Running this image results in the following kernel panics:

Kernel panic - not syncing: Asynchronous SError Interrupt
CPU: 3 PID: 1 Comm: swapper/0 Not tainted 6.1.0-rpi8-rpi-2712 #1 Debian 1:6.1.73-1+rpt1
Hardware name: Raspberry Pi 5 Model B Rev 1.1 (DT)

I copied the files from a bookworm Raspberry Pi OS to the boot partition of the Pimiga image, only preserving the cmdline.txt for booting the correct partition.

While preparing to attach the electrical candles to the Christmas tree, a question popped into my mind.

There are electrical candles that simulate the flickering of real candles. How complex would an algorithm have to be to be convincing?

I wrote a quick proof of concept in Ruby for a script running in the terminal which just randomly chooses a grey value to display.