Purge from memoryCache (while leaving in composed diskCache)?

[jbmaxwell]

Just curious whether there's a simple way (that I haven't seen) to remove an item from a memoryCache, while leaving it in the diskCache (I have a disk+memory composition). I want to be able to free up memory (on iOS), but retain the option to quickly reload from diskCache.

Thanks in advance.

[dreymonde]

Hi! There was a very similar issue: #7
Check it out and ping me if you’ll still have any questions after it!

[jbmaxwell]

Ah, okay, didn't see that. Thanks.
So, if I wanted to clear a single item, I'm guessing it might be something like: memoryCache.storage[<myKey>] = nil
Yes?

[dreymonde]

@jbmaxwell yes, that’s right!

[jbmaxwell]

Perfect. Super simple. Thanks.

[jbmaxwell]

Hmm, has something changed? I can't seem to get .storage at all... I only see asStorage(), but that doesn't support subscripting. I'd actually like to add a function to delete items from both disk and memory storage (in a combined disk+memory storage). How would I do that?

[dreymonde]

storage exists only for MemoryStorage instances. For DiskStorage, I’m afraid, you’ll need to provide your own solution

[jbmaxwell]

Ah, okay. And I suppose a DiskStorage combined with a MemoryStorage is fundamentally a DiskStorage? (Because my combined MemoryStorage also doesn't have .storage.):

let myMemoryCache = MemoryStorage<Filename, Chord>()
        .combined(with: DiskStorage.main.folder("stuff", in: .cachesDirectory).mapJSONObject(Chord.self))

This also doesn't recognize .storage.

[dreymonde]

When you perform any kind of transformation (mapping, combining, etc.), the original type information is lost. When you combine MemoryStorage with DiskStorage, you get just abstract Storage<Key, Value>

[dreymonde]

Check #7 for how to deal with this in certain scenarios

[jbmaxwell]

Okay, I can see what you're doing in MemoryStorage, but I don't understand exactly how I'd do something similar for DiskStorage (or I suppose, for Storage)—your code is beautiful, but terse.
I'll figure out a workaround... Would it work to just remove the disk item, as in DiskStorage's clear() function?
UPDATE: Deleting using fileURL() works for the DiskStorage but, as I expected, the MemoryStorage still has the item... Is there a way to refresh the MemoryStorage, based on the DiskStorage? Or can I get a reference to the MemoryStorage only from a combined Storage? (Wouldn't it be reasonable to have a built-in function to remove items?)