Is it possible to delete an entire instance?

[gabimoncha]

Is it possible to delete an entire instance?

[lingol]

Just call close(). Be careful though, once closed, you should never call any other methods on that instance.

[lingol]

Oh, if you want to delete the underlying storage as well, you should call OS's remove() or unlink() or something like that to delete the file & CRC file directly. MMKV doesn't provide methods to delete the storage.

[gabimoncha]

So if I want to completely wipe out the storage and mmkv instance, I would first have to remove keys and then close the instance?

I'm asking because in my react native app, I remove the keys from the encrypted storage, but I cannot initialise another instance with the same id, but different encryption key.

I first have to check if the instance was created before, in this case I empty and decrypt it on removal, then next time I instance it with the same id and encrypt it with a new key right after.

[gabimoncha]

I tried looking before in the source code but didn't manage to find those methods, that's why I asked here. Can you please link it for me?

[lingol]

In your scenario, you may be looking for reKey(). Here's how it's done right with reKey:

1. Open the existing instance with the old encryption key.
2. Delete existing keys by calling remove() or removeAll().
3. Call reKey() with the new encryption key.
4. Use the instance as if it's a new one.

[gabimoncha]

Thank you @lingol! But this still needs me to check if the I created an instance before this.
Can't I just remove it and then create a new one?
From what you've said, calling clear() would remove instance with keys all together?
Then next time, I can use the same code for creating an encrypted instance (even if it has the same id, but a different encryption key)

[lingol]

No. You can't do that. The file keeps its last encryption info even empty (after removeAll() or clear()). There are no methods inside MMKV for you to erase the underlying storage. Like I have mentioned before, you have to call the system's method to do it.

[lingol]

OS means operating system, by the way.

[gabimoncha]

Ok, thank you for your help.