Loading performance is very poor

[Rybadour]

Currently loading Foreman is extremely slow. It can take up to a minute for a large mod to load. A player with a few different (even disabled) mod packs can find themselves waiting a long time on both the load of Foreman and any time they change the enabled mods list.

Some suggestions for improvements:

• Avoid loading mods that aren't enabled when Foreman starts up.
• Cache the recipe and item data we collect from mods in a simplified format such as JSON. Hash the files based on the mod version or contents of the mod directory.
• Save mod data in memory to speed up changing the enabled mod list.
• Asynchronously load mod data rather than blocking.
• (Stretch goal) Come up with a stand-alone program that produces a JSON file that Foreman understands and ask mod authors to include it along side their mods. Parsing a single file per mod would be a huge speed up.

[Rybadour]

Most of the slowness is in unzipping mods. This is the first thing we do in order to parse info.json and understand the dependencies mods have on each other. Ultimately this is unnecessary for loading mod data. It's only necessary when selecting mods to enable (if we want to understand their dependencies). Initially we don't care so I'm going to try changing this just list the names of the mods first.

[Rybadour]

Fixed some loading performance by avoiding extracting mods that aren't enabled: https://github.com/Rybadour/Foreman/commit/b1e1d6b98c1770a60a88a2a1f45d8ac7d17e7ca6

[Rybadour]

Recent fixes to the Zip extraction code unlocked some new ways to boost performance. I'm closing this because I think the performance issues are mostly gone and the extra work mentioned here is probably unecessary.