D is nice whats really wrong with gc??

[bomat]

On Friday, 22 December 2023 at 22:33:35 UTC, H. S. Teoh wrote:
> IMNSHO, if I had very large data files to load, I wouldn't use 
> JSON. Precompile the data into a more compact binary form 
> that's already ready to use, and just mmap() it at runtime.

I wondered about that decision as well, especially because this 
was internal game data that did not have to be user readable.
That's beside the point though; it was a ~10 MB JSON file that 
took them several minutes to parse. That's really just insane. 
Turns out it helps if you don't count the length of the entire 
document for every single value. It also helps if you don't 
iterate over your entire array of already written values every 
time you want to insert a new one. :)
In case you didn't know the story, here's a link:
https://nee.lv/2021/02/28/How-I-cut-GTA-Online-loading-times-by-70/

I think there are several great lessons in there. Rockstar must 
have noticed how slow the loading is, but apparently just 
accepted it as a given... for 7+ years. Who needs optimizations 
on today's great hardware, right? There couldn't possibly be 
algorithmic problems in something simple like a JSON parser, 
right?
Second, look at what people suspected as the root cause of the 
problem, like the P2P architecture. It's funny how speculations 
about performance problems are *always* wrong. Only measuring 
will tell you the truth.