Fare Estimation script
The script can accept two parameters: farecalc paths.csv fares.csv (input csv and output csv). If you omit any of those,
the script will default to stdin or stdout respectively, which means you can also pipe data through it, eg:
cat paths.csv | farecalc >> out.csv
The main requirements for this script were: use of concurrency, be performant and the fact that it should be "a script", not an application that would ingest a kafka topic for eg... Thus, I chose to go with a very simple design for this script (could be even simpler), eg. no sub-packages, I was sparse with types, interfaces, decoupling, no use of decimal's etc...
The script basically has 3 components:
- csv source / ingester - reads csv lines, groups them by rideID and dispatches those groups of paths as work.
- pool of workers which consume the work (paths), parse segments and filter them, segment fare calculation and aggregation. (separation of concerns could be a lot better here, but as I said, due to performance requirements I did not want to do any more work or allocations than neccessary)
- an output sink which consumes fare estimations and writes them to output.
I also included some unit tests and a single integration test (golden file). (I was not exhaustive here)