Print allocation statistics in pools and arenas

[gavv]

core::SlabPool and core::HeapArena are two classes through which roc performs most allocations.

It would be convenient to see simple allocation statistics from them in logs:

• total currently allocated bytes
• total currently allocated objects
• average bytes per second during period
• average objects per second during period

We can compute and print this statistics, say, with period of one minute.

There is a class core::RateLimiter that allows to check if next period expired. We can do this check e.g. after every allocation.

[Napetrou]

Hello, i would love to help, i'm complete beginner in contributing to open source projects but i am familiar with c++, i think i can help, but if i come across any problems i might need some guidance, so may i contact if i have any issues? Thanks in advance and i apologize if this isn't the right way of communicating here.

[gavv]

You're welcome, thanks. Please take a look at this page: https://roc-streaming.org/toolkit/docs/development/contribution_guidelines.html and feel free to ask questions here or in matrix chats.

[gavv]

@Napetrou Hi, do you still plan to work on it?