Db Mysql implementation

[nivcoo]

Hello,

If you have any times maybe sunday with the new release to ADD db support for preferences, because actually i use multi servers instances and when players changes the server it will reset their preference. Also i use docker so the file isn't saved after restart, it could be very good to have an opti to set mariadb/mysql as stockage method. Thanks you, i will fork the plugin with your recent getHolder method to try to add it by myself but i will prefer if you can do it, it will be better, thanks you

[BenWoodworth]

Hey! I'm working on that release right now, though I haven't had much time recently so I'm not sure I'll be able to work on this.

That said, I could definitely give you some pointers! I just checked, and tomorrow it'll be half a decade to the day since I wrote the preferences code that's there now, so I'm definitely rusty with it, but I do have an idea how it all works! And if it's well-tested, I'm certainly open to merging it in too :)

[BenWoodworth]

Here's a rough idea of what needs to be done:

• Configuration option for SQL connection? Maybe like database: url: "jdbc:...:fastcraft.sqlite" (and driver, username/password`/etc.? not sure if/how plugins typically make it configurable)
  • In the FastCraftConfig class, add an inner class Database similar to the other inner classes
    • Add a property private val node: FcConfigNode get() = config["database"] (example)
    • In it, add a property something like var url: String = "some-connection-string:${fcPluginData.dataFolder.resolve("fastcraft.sqlite")}"
    • Add a load function that loads it with node["url"].loadString(...) (example)
• Rename the old preferences classes:
  • FastCraftPreferencesImpl -> RowStorageFileFastCraftPreferences
  • BukkitFastCraftPreferencesImpl -> RowStorageFileBukkitFastCraftPreferences
• Add new preferences classes for sqlite
  • SQLiteFastCraftPreferences and SQLiteBukkitFastCraftPreferences
  • Implemented similar to the old classes, except with databases
• Add setup logic to SQLiteFastCraftPreferences
  • If the database doesn't exist yet, then:
    • Create the database
    • Add a PlayerPreferences table
    • If the old preferences file exists, then get an instance of the RowStorageFileFastCraftPreferences, and copy all the old preferences to the new database
      • You can get an instance in the constructor with private val rowStorageFileFastCraftPreferencesProvider: Provider<RowStorageFileFastCraftPreferences>
      • You might also need to add a function like fun exportRows(): Sequence<ExportedRow>
        • Looping similar to getPlayerRow, implementing it as

          •     data class ExportedRow(val playerId: UUID, enabled: Boolean?)
                
                fun exportRows(): Sequence<ExportedRow> {
                    return sequence { 
                        for (row in 0L until file.rowCount) {
                            val rowBytes = ByteArray(ROW_LEN)
                            file.readRow(row, rowBytes)
            
                            val rowUuid = ByteArray(ROW_UUID_LEN)
                            file.readRow(row, rowUuid, ROW_UUID_LOC)
                            yield(rowUuid.toUuid())
                        }
                    }
                }

            • you'll also need to add a .toUuid() function, the opposite of UUID.toByteArray() in the same file
• Change the dependency injection in BukkitFastCraftModule to provide the new preferences classes instead
• Mark the RowStorageFile[Bukkit]FastCraftPreferences classes with @Deprecated("some message") with a message about using the new class instead
• Ideally, add unit tests for SQLiteFastCraftPreferences in fastcraft-core
  • Reading/writing preferences, initializing database, copying from the old preferences file, ...

(I'll update this if more things come to mind)