Add performance analysis tools

[DaKnig]

without them, we can speculate about performance all we want. adding flame graphs is the easy first step but it is not the whole solution. IMO we should also look at how the program behaves over time under heavy load.

[DaKnig]

this also means adding more (stress) tests

[evie-calico]

I'm not necessarily concerned about the performance of the program at the moment. Other than parallelization, which is important for stress-testing, I don't think anything can be reasonably improved.

[DaKnig]

the bottleneck is not the computation actually , it is the file opening and parsing. I think with the right changes we can make this run at one order of magnitude faster