Storing per-world data

[ClubPT]

So I have a collection of data that I want to change per-world.  It's a simple Map<ResourceLocation, int>.  But the ints should be calculated once and shared across the world (savegame).  I have all the code to create the ints for new ResourceLocations as I find them, my question is what would be the best place to store this data?  I thought of the following options:

1. Custom NBT data on Chunk 0,0,0
2. Custom file saved in the savegame directory (alongside level.dat)
3. Custom file, saved in the "data" directory in the savegame directory
4. Config file save in "serverconfig"

Option #1 has the bonus of being hard for the average player to see, as the data is akin to passcodes, but it feels kludgy to me. 

Is the a recommended place to store this type of data? Something that MC or forge has functions/serializers already written for?

Thanks

-pete

[ChampionAsh5357]

Use SavedData. If you want to store it per-world, only add it to the overworld level.