The repo sharing wishlist

[lineargraph]

It would be nice (for some definition thereof), if HSB mods could share the repo data. This issue is a meta thread for collecting ideas of how this should be done, what goals we are setting for ourselves, possibly implementation details, etc.

[lineargraph]

For me i see three tiers of repo sharing:

File sharing

Share the underlying files between mods, one download, multiple loads into memory of those same files. Even in this tier we probably want our own configuration in the repo parser that gets exposed in some way so downstream consumers can display this configuration in their own UIs. We want a downloader (that can potentially follow multiple branches, at least internally), we want an update check (that can be disabled), we want a system to notify consumers that they should reload their files from disk, that is about all we need in this tier. This could be done completely independent of any Minecraft code, and locks in with a very minimal ABI surface that we need to maintain.

We probably (for our windows users) want a system that makes sure no one mod locks file handles, since windows can be fuzzy about that kind of stuff. Someone who has more experience with windows stuf feel free to weigh in on this one. Close your file handles regardless, but especially for something like this it feels important.

JSON sharing

In addition to everything we did earlier, we additionally expose readily parsed datasets for all the JSON data we parse already. This locks our API surface down more, we need more backwards compat guarantees, but we also save a lot of CPU and disk IO, likely.

Item sharing

In addition to earlier tiers, we also depend on a specific MC version, and load ItemStack(Template)s that can then be used by consumers. This arguably frees up our API surface a bit, since we then have guaranteed version breaks whenever there is a new MC major version. We can emulate that in the earlier tiers by having major version breaks and then simply declaring which MC version ranges should use which of the major versions, so we don't gain much, but those version range declarations simply become enforced as a design decision.