Bug: Use of pimpl pattern

[dimitry-ishenko]

Observed Behavior

Every time peek into the Server innards, it makes me cringe a little. 😄 I think I've asked this before, but I don't remember what the answer was...

Why do we use pimpl pattern for the Server?

I understand when you have a library and you want to (1) hide implementation details from users, and/or (2) keep the ABI constant. That's when pimpl design comes in handy. Well, also (3) it helps reduce compilation time.

Expected behaviour

Neither (1) nor (2) applies to the Server though. Looking at the amount of headers included in the implementation files, I am not so sure (3) does very much either. Plus, there are other ways to mitigate compilation times.

Downsides of pimpl are pretty substantial:

• Lots of boilerplate code.
• Dynamic allocation.
• Extra layer of indirection.
• Massive code pessimisation (compiler can't inline or elide function calls).

I would expect the Server to use the usual OO pattern with no pimples (pun).

Steps to reproduce

1. Open the Server code in your favorite editor.
2. Observe the pimpl pattern being used everywhere.
3. Cringe a little 😉

Environment

• Server version: v2.4.x
• Operating system: N/A