Coding Challenge - Invert Case Performance

This is a performance challenge. The task is simple, read some ASCII words from stdin, invert the case ('aBcDeF' => 'AbCdEf'), then push the result to stdout. The goal is to beat the performance of the baseline dotnet core implementation.

Rules

The only rule is you cannot modify the benchmarking application code. Any other extreme optimizations or 'creative' solutions are allowed. For those attempting 'creative' solutions, I'd also suggest providing a 'real' solution as well. I'm being intetionally vague here.

Protocol

There is a very simply protocol between the benchmarking app and the target application.

1. Recieve "#BEGIN\r\n"
   • Benchmarking application wishes to start a bencharmking pass.
2. Send "#READY\r\n"
   • Target application does whatever warmup and prep processing required before returning this signal
   • After the ready signal is recieved, the benchmarking timer begins
3. Send words (example: "AbCdEf\r\n")
   • Words are sent in 64kb chunks
   • Sends are asynchronous, the benchmarking application will consume results as they are returned
4. Recieve inverted case words (example: "aBcDeF\r\n")
   • Make sure you are appending \r\n with the results. This is not the default on most platforms.
5. Send "#END {n}\r\n"
   • n is the pass number (example: "#END 0\r\n")
   • The benchmarking application will now stop the benchmarking timer and verify the results
   • If the results are incorrect, errors will be returned
6. GOTO 1
   • Benchmarking application will run 10 passes
   • Slowest pass will be thrown out
   • Results are reported as a percentage of the baseline application

How?

First, Fork the repository.

Next, replace the CodeChallenge.Target implementation with your own version. You aren't limited to C# and dotnet for this. Anything that will execute in a docker container is eligable. Write your solution in javascript, go, rust, webassembly or any other language you want. Just update fixture.Dockerfile to include an appropriate build/runtime environment for your language of choice.

You can run docker-compose run debug to test your implementation. All stdout and stderr streams from your application will be echoed to the console. When you're ready to run for real just run docker-compose run benchmark. The benchmark will run the baseline first and your implementation next. You'll recieve a list of run times for each pass and a final score.

Questions

• It looks like the benchmark app is freezing, what's going on?
  • Most likely you've missed the \r\n characters after a message. These are required even on linux.
• Why did you do [x] like that?
  • I've set this up as an educational project, so the protocol design was done with a specific implementation in mind.
• How will submissions be ranked?
  • 'Creative' and real solutions are ranked independantly
  • Fast solution is the winner