Modern Concurrency: Beyond the Basics
About this episode
See forum comments
Mark complete
Next episode: 20. Conclusion
Leave a rating/review
Heads up... You’re accessing parts of this content for free, with some sections shown as text.
Heads up... You’re accessing parts of this content for free, with some sections shown as text.
Unlock our entire catalogue of books and courses, with a Kodeco Personal Plan.
Unlock now
In this challenge, you’ll finish the debugging toolbar by connecting the second counter to display on-disk cache hits and making the last toolbar button clear the disk cache.
@MainActor private(set) var onDiskAccess: AsyncStream<Int>?
private var onDiskAccessCounter = 0 {
didSet { onDiskAcccessContinuation?.yield(onDiskAccessCounter) }
}
private var onDiskAcccessContinuation: AsyncStream<Int>.Continuation?
func setUp() async throws {
storage = await DiskStorage()
for fileURL in try await storage.persistedFiles() {
storedImagesIndex.insert(fileURL.lastPathComponent)
}
await imageLoader.setUp()
🟩
let accessStream = AsyncStream<Int> { continuation in
onDiskAcccessContinuation = continuation
}
await MainActor.run { onDiskAccess = accessStream }
🟥
}
deinit {
onDiskAcccessContinuation?.finish()
}
onDiskAccessCounter += 1
onDiskAccessCounter = 0
print("Cleared disk cache.")
.task {
guard let diskAccessSequence = ImageDatabase.shared.onDiskAccess else {
return
}
for await count in diskAccessSequence {
onDiskAccessCount = count
}
}
Button(action: {
// Clear on-disk cache
🟩
Task {
await ImageDatabase.shared.clear()
}
🟥
}, label: {
Image(systemName: "folder.badge.minus")
})