this reduces the risk of OOM during conversion of large worlds
we probably ought to limit the size of region caches for regionized worlds, but that's a problem for another time.
instead, just ungate this and allow the provider to decide what to do.
Any chunk that contains entities or tiles is already always considered dirty, so the only thing the flags are good for is flagging chunks that previously had tiles and/or entities but no longer do.
In those cases, it's just removing keys from LevelDB anyway, so it's already very cheap.
Avoiding these redundant deletions is not worth the extra complexity and fragility of relying on flags to track this stuff.
WorldProviders now have the following requirements removed:
- __construct() is no longer required to have a specific signature
- static isValid() no longer needs to be implemented (you will still need it for registering, but it can be declared anywhere now)
- static generate() no longer needs to be implemented
This paves the way for more interesting types of world providers that use something other than local disk to store chunks (e.g. a mysql database).
WorldProviderManager no longer accepts class-string<WorldProvider>. Instead, WorldProviderManagerEntry is required, with 2 or 3 callbacks:
- ReadOnlyWorldProviderManager must provide a callback for isValid, and a callback for fromPath
- WritableWorldProviderManagerEntry must provide the same, and also a generate() callback
In practice, this requires zero changes to the WorldProviders themselves, since a WorldProviderManagerEntry can be created like this:
`new WritableWorldProviderManagerEntry(\Closure::fromCallable([LevelDB::class, 'isValid']), fn(string ) => new LevelDB(), \Closure::fromCallable([LevelDB::class, 'generate']))`
This provides identical functionality to before for the provider itself; only registration is changed.
this can fail if the backups directory points to a different drive than the original worlds location. In this case, we have to copy and delete the files instead, which is much slower, but works.
I REALLY advise against putting backups on a different mount point than worlds if you plan to convert large worlds.
