Straight array of structs. The complication was that there were several of them, they were stored in bus-attached MRAM which was accessed directly (e.g. mmap of /dev/ram) by several independent processes.

The idea came from previous generations of the product which generally ran on microcontrollers coupled with custom FPGA designs, so, not entirely unwarranted.. but completely incorrect for a newer product with much greater computing power than their previous devices.