Cache API in Coil 2

[yschimke]

Just wondering about the Cache API in Coil 2. It's implemented internally via Okio Filesystem, wondering whether it's useful to use that as the API also instead of java.io.File?

interface DiskCache {
    /** The directory where the cache stores its data. */
    val directory: File

Not critical, just easier when I'm using Okio on my side anyway, and for testing via Okio FakeFileSystem etc.

[colinrtwhite]

@yschimke I think this is a great idea! Open to a PR if you'd like to implement this otherwise I can give it a shot. I think we'd probably want to convert all File references in DiskCache and DiskLruCache to Paths. As you mentioned, we should also expose DiskCache.Builder.fileSystem.

[yschimke]

Happy to.

[yschimke]

#1115