Option to Disable Extraction/Install Step on Each Run

[d10sfan]

Option to Disable Extraction/Install Step on Each Run

[dreamer]

I remember this issue existing since the very beginning, and one of the reason was: correctly handling package updates (which was non-trivial when some game engines decided to effectively avoid doing any versioning at all).

I considered several options, and ATM I think checking for hashes might be the best solution after all... Perhaps we don't need to store hashes in packages themselves - they could be calculated once after tarball is downloaded and kept in a file in the cache.

[d10sfan]

Yeah that's a good idea, hashing the downloads as they come in and storing the result in a file, then can check if there's any differences between the hashes found on disk and the ones generated at runtime.

The hash file could be a file with an array of hashes for each app id & choice combination. So then when the game launches again, a new array would be generated of all the hashes used, and if any of them don't match, extract the ones that don't match. So the hash file could be stored in ~/.cache/luxtorpeda/hashes/appid-choice.json. Choice would be there in cases for doom, where someone could pick between gzdoom and other engines for example.

It looks like there's some examples of hashing files in sha: https://github.com/RustCrypto/hashes#hashing-readable-objects.

It'll probably also be a good idea to make this configurable with the config.json file, to allow it to do what it does currently, to extract on each run, but then if enabled, it'd check the hash first and if so, skip the extraction step.

[d10sfan]

This is implemented in #206

The next release will have it.