Sometimes it can be useful to try to determine just how efficient a particular piece of code is, or to figure out if one could speed up things more than they are. There are many ways to test the performance of Python and the running server.
That is, don't start to try to optimize your code until you have actually identified a need to do so. This means your code must actually be working before you start to consider optimization. Optimization will also often make your code more complex and harder to read. Consider readability and maintainability and you may find that a small gain in speed is just not worth it.
The `setup` keyword is used to set up things that should not be included in the time measurement, like `a = []` in the first call.
By default the `timeit` function will re-run the given test 1000000 times and returns the *total time* to do so (so *not* the average per test). A hint is to not use this default for testing something that includes database writes - for that you may want to use a lower number of repeats (say 100 or 1000) using the `number=100` keyword.
Python comes with its own profiler, named cProfile (this is for cPython, no tests have been done with `pypy` at this point). Due to the way Evennia's processes are handled, there is no point in using the normal way to start the profiler (`python -m cProfile evennia.py`). Instead you start the profiler through the launcher:
This will start Evennia with the Server component running (in daemon mode) under cProfile. You could instead try `--profile` with the `portal` argument to profile the Portal (you would then need to [start the Server separately](../Setup/Running-Evennia.md)).
Please note that while the profiler is running, your process will use a lot more memory than usual. Memory usage is even likely to climb over time. So don't leave it running perpetually but monitor it carefully (for example using the `top` command on Linux or the Task Manager's memory display on Windows).
Once you have run the server for a while, you need to stop it so the profiler can give its report. Do *not* kill the program from your task manager or by sending it a kill signal - this will most likely also mess with the profiler. Instead either use `evennia.py stop` or (which may be even better), use `@shutdown` from inside the game.
Once the server has fully shut down (this may be a lot slower than usual) you will find that profiler has created a new file `mygame/server/logs/server.prof`.
The `server.prof` file is a binary file. There are many ways to analyze and display its contents, all of which has only been tested in Linux (If you are a Windows/Mac user, let us know what works).
You can look at the contents of the profile file with Python's in-built `pstats` module in the evennia shell (it's recommended you install `ipython` with `pip install ipython` in your virtualenv first, for prettier output):
How to analyze and interpret profiling data is not a trivial issue and depends on what you are profiling for. Evennia being an asynchronous server can also confuse profiling. Ask on the mailing list if you need help and be ready to be able to supply your `server.prof` file for comparison, along with the exact conditions under which it was obtained.
It is difficult to test "actual" game performance without having players in your game. For this reason Evennia comes with the *Dummyrunner* system. The Dummyrunner is a stress-testing system: a separate program that logs into your game with simulated players (aka "bots" or "dummies"). Once connected, these dummies will semi-randomly perform various tasks from a list of possible actions. Use `Ctrl-C` to stop the Dummyrunner.
This will override your settings and disable Evennia's rate limiters and DoS-protections, which would otherwise block mass-connecting clients from one IP. Notably, it will also change to a different (faster) password hasher.
The inputs/outputs from the dummy will then be printed. By default the runner uses the 'looker' profile, which just logs in and sends the 'look' command over and over. To change the settings, copy the file `evennia/server/profiling/dummyrunner_settings.py` to your `mygame/server/conf/` directory, then add this line to your settings file to use it in the new location:
The dummyrunner settings file is a python code module in its own right - it defines the actions available to the dummies. These are just tuples of command strings (like "look here") for the dummy to send to the server along with a probability of them happening. The dummyrunner looks for a global variable `ACTIONS`, a list of tuples, where the first two elements define the commands for logging in/out of the server.
