initial commit

Cheetah/ModelDownloader.swift

@@ -0,0 +1,71 @@
+import Foundation
+
+extension Bundle {
+    var displayName: String? {
+        return object(forInfoDictionaryKey: kCFBundleNameKey as String) as? String
+    }
+}
+
+var cacheDirectory: URL {
+    let parent = FileManager.default.urls(for: .cachesDirectory, in: .userDomainMask)[0]
+    return parent.appending(path: Bundle.main.bundleIdentifier!)
+}
+
+class ModelDownloader {
+    enum State {
+        case pending
+        case completed
+        case failed(Error?)
+    }
+    
+    @Published var state = State.pending
+    
+    let baseURL = URL(string: "https://huggingface.co/datasets/ggerganov/whisper.cpp/resolve/main")!
+    
+    let modelName: String
+    let session: URLSession
+    let filename: String
+    let modelURL: URL
+    
+    var task: URLSessionDownloadTask?
+    
+    init(modelName: String, configuration: URLSessionConfiguration = .default) {
+        self.modelName = modelName
+        session = URLSession(configuration: configuration)
+        filename = "\(modelName).bin"
+        modelURL = cacheDirectory.appending(path: filename)
+    }
+    
+    func resume() {
+        if !FileManager.default.fileExists(atPath: cacheDirectory.absoluteURL.path) {
+            try! FileManager.default.createDirectory(at: cacheDirectory, withIntermediateDirectories: false)
+        }
+        
+        let destination = modelURL.absoluteURL
+        if FileManager.default.fileExists(atPath: destination.path) {
+            state = .completed
+            return
+        }
+        
+        let request = URLRequest(url: baseURL.appending(path: filename))
+
+        let task = session.downloadTask(with: request) { [weak self] location, response, error in
+            if let error = error {
+                self?.state = .failed(error)
+                return
+            }
+            if let location = location {
+                do {
+                    try FileManager.default.moveItem(at: location, to: destination)
+                    self?.state = .completed
+                } catch {
+                    self?.state = .failed(error)
+                }
+            } else {
+                self?.state = .failed(nil)
+            }
+        }
+        task.resume()
+        self.task = task
+    }
+}