Building a memory visualizer/profiler with mlua and luau

[Polanas]

Greetings!
I'm looking for any kind of hints/help with getting memory allocation data (ideally per table/function/thread/etc) from a lua/luau instance. Roblox have introduced this feature last year (announcement link). This is probably not the best place to ask this, but I haven't been able to find a better one.

I've managed to get some very general info (total memory used/freed, total allocations amount) via a custom allocator function. There also seems to be C api for retrieving total bytes per type (lua_setmemcat, lua_totalbytes). I'm totally stuck on how to proceed from here. How would one approach this?

If there's an open source implementation of something like this, please share it :) (the ones I've look at were quite bare-bones). Any help at all would be greatly appreciated!

[khvzak]

I don't think that open source version provides such detalization.

lua_setmemcat only sets a memory category (e.g. before executing a script) and lua_totalbytes can retrieve total memory for that category. And probably that's it.

Would be better to ask for some guidance in https://github.com/luau-lang/luau

[Polanas]

Thanks for the reply! That's a bit unfortunate, if it's indeed the case. Alright, I'll try my luck at luau

[qwitwa]

@khvzak is this not related to the heap-dump walking scripts, e.g. https://github.com/luau-lang/luau/blob/bb3956547affc1af7b7d196f96756895255dd05d/tools/heapgraph.py that rely on luaC_dump?

[khvzak]

I was not aware about this private api. Thanks for the link.
In that case it should be possible. I'll take a look to this api later next week