Consider exposing a custom file location for the iCloud metadatabase files?

[robfeldmann]

Hey there. This is a minor annoyance (for me, on iOS at least) but would you consider exposing a way to modify the location of the metadabase files? It is a bigger deal for me on macOS.

I like to store my database in Application Support/MyApp/Database/[db.sqlite|db.sqlite-shm|db.sqlite-wal] in order to group these files and make it easier to delete all of them during development, etc.

Using sharing-grdb-icloud, I now have Application Support/[*.sqlite-data-icloud|*.sqlite-data-icloud-shm|*.sqlite-data-icloud-wal] and this bugs me that I don't have these metadatabase files somewhere organized.

Actually, I just realized on macOS these files are in the root of my ~/Library/Application Support folder and not inside ~/Library/Application Support/MyApp like I'd expect.

So, perhaps a new field on the defaultSyncEngine dependency value?

  extension URL {
    package static func metadatabase(containerIdentifier: String?) throws -> Self {
      ...
      if context == .live {
        try FileManager.default.createDirectory(
          at: .applicationSupportDirectory,
          withIntermediateDirectories: true
        )
        base = .applicationSupportDirectory
      } else {
        ...

Thanks for considering this.

[mbrandonw]

Hi @robfeldmann, thanks for brining this up. We haven't given much thought to this so would want to get advice from the community.

What if we simply put the meta database file in the same directory that your database is stored?

[robfeldmann]

I actually had that same thought right after posting. That'd be great.

[mbrandonw]

Is this something you'd be interested in contributing? I can give you write access to the private alpha repo so that you can create a PR.

Otherwise I will add it to our list of todos to take on at some point.

[robfeldmann]

Hey @mbrandonw I started work on this, FYI. A few things came up if you could let me know what you prefer/think?

1. If the metadatabase is at Application Support/ but not where the userdatabase is, should it be moved, left where it is, or deleted and let the logic outlined below happen?

2. Going forward, if userdatabase's path is empty or == ":memory:", then the existing behavior will be used (Application Support/ for live, temporary for previews/tests).

3. Otherwise the metadatabase will be placed in the same directory as userdatabase.

I can also just submit a PR.

Thanks!

[stephencelis]

@robfeldmann Oops, sorry I didn't see this. I put up a PR for review here: https://github.com/pointfreeco/sharing-grdb-icloud/pull/41

But it could use some finesse given the points you brought up.

1. We're still in the alpha stage so I think we can just have a hard breakage here.
2. I think we probably shouldn't support in-memory databases at all, since they don't make sense to sync, so this should probably throw an error
3. 👍

Thoughts? Do you want to share what you've been working on and maybe we can combine our efforts?

[robfeldmann]

Your PR is terrific. I agree with your answers to the points I raised. I was traveling and much busier than expected to submit my own PR sooner. I don't think any more finesse is needed. Mine was basically the same with a couple exceptions I pointed out in my review. Thanks so much for this!