Cycle race track lap counter

Maybe I'll just switch back to RAM and just use binary, reserved data for now.

Is there a way to safely acquire memory without crashing the system?
Something like:

1. determine how much memory we have left process.memory().free
   
2. subtract some margin of memory left unallocated (how much would you suggest?)
   
3. calculate how big my ArrayBuffer can get (any clues here?)
   
   

Or I'll just do it via trial + error and put the hardcoded numbers in...