Address Copilot review feedback

Author: github-actions[bot]

Sources/MLXInferenceCore/InferenceEngine.swift

@@ -528,11 +528,17 @@ public final class InferenceEngine: ObservableObject {
                     }
 
                     let mlxMessages = finalMessages
-                    var params = GenerateParameters(temperature: config.temperature)
-                    params.topP = config.topP
-                    params.topK = config.topK
-                    params.minP = config.minP
-                    params.repetitionPenalty = config.repetitionPenalty
+                    var params = GenerateParameters(
+                        maxTokens: config.maxTokens,
+                        kvBits: config.kvBits,
+                        kvGroupSize: config.kvGroupSize,
+                        temperature: config.temperature,
+                        topP: config.topP,
+                        topK: config.topK,
+                        minP: config.minP,
+                        repetitionPenalty: config.repetitionPenalty,
+                        prefillStepSize: config.prefillSize
+                    )
                     params.repetitionContextSize = 20
 
                     var thinkingActive = false
@@ -604,13 +610,7 @@ public final class InferenceEngine: ObservableObject {
                     continuation.yield(GenerationToken(text: "\n\n[Error: \(error.localizedDescription)]"))
                 }
 
-                // Also check the latch one final time (for errors that occurred during
-                // generation and caused the stream to end without throwing)
-                if let latchedError = SSDStreamingErrorLatch.shared.consume() {
-                    let msg = "Model weights are corrupted or incomplete. Please re-download the model."
-                    print("[InferenceEngine] Latched SSD error after generation: \(latchedError.localizedDescription)")
-                    self.markModelCorrupted(modelId: self.currentModelId, message: msg)
-                } else if case .error = self.state {
+                if case .error = self.state {
                     // Already in error state from catch block above
                 } else {
                     self.state = self.currentModelId.map { .ready(modelId: $0) } ?? .idle

Sources/MLXInferenceCore/ModelDownloadManager.swift

@@ -57,6 +57,8 @@ public final class ModelDownloadManager: ObservableObject {
     @Published public private(set) var totalDiskUsageBytes: Int64 = 0
     @Published public private(set) var networkStatus: NetworkStatus = .unknown
 
+    private var downloadedModelIDs: Set<String> = []
+
     // MARK: Persistence
     private let lastModelKey = "swiftlm.lastLoadedModelId"
     public var lastLoadedModelId: String? {
@@ -131,6 +133,7 @@ public final class ModelDownloadManager: ObservableObject {
                 modifiedDate: s.modifiedDate
             )
         }
+        downloadedModelIDs = Set(downloadedModels.map(\.id))
         totalDiskUsageBytes = downloadedModels.reduce(0) { $0 + $1.sizeBytes }
 
         // Scan for interrupted downloads that can be resumed
@@ -142,7 +145,7 @@ public final class ModelDownloadManager: ObservableObject {
     }
 
     public func isDownloaded(_ modelId: String) -> Bool {
-        ModelStorage.isDownloaded(modelId)
+        downloadedModelIDs.contains(modelId)
     }
 
     /// True if a model has a partial download that can be resumed.

Sources/MLXInferenceCore/ModelDownloader.swift

@@ -166,6 +166,16 @@ public final class DownloadSpeedTracker: @unchecked Sendable {
     }
 }
 
+private struct DownloadedFileSizeMismatchError: LocalizedError {
+    let fileName: String
+    let expectedSize: Int64
+    let actualSize: Int64
+
+    var errorDescription: String? {
+        "Downloaded file \(fileName) is incomplete (expected \(expectedSize) bytes, got \(actualSize))."
+    }
+}
+
 // MARK: — Downloader actor
 
 public actor ModelDownloader {
@@ -276,14 +286,20 @@ public actor ModelDownloader {
             guard let freshHttp = freshResponse as? HTTPURLResponse, (200..<300).contains(freshHttp.statusCode) else {
                 throw URLError(.badServerResponse)
             }
-            try await streamToFile(
+            let totalSize = freshHttp.expectedContentLength > 0 ? freshHttp.expectedContentLength : (expectedSize ?? 0)
+            let writtenSize = try await streamToFile(
                 asyncBytes: freshBytes,
                 destURL: incompleteURL,
                 resumeOffset: 0,
-                totalSize: freshHttp.expectedContentLength > 0 ? freshHttp.expectedContentLength : (expectedSize ?? 0),
+                totalSize: totalSize,
                 speedTracker: speedTracker,
                 onProgress: onProgress
             )
+            try validateCompletedDownloadSize(
+                fileName: fileName,
+                actualSize: writtenSize,
+                expectedSize: totalSize > 0 ? totalSize : expectedSize
+            )
         } else if (200..<300).contains(http.statusCode) {
             // 200 = full content (server ignored Range), 206 = partial content (resume worked)
             let isResume = (http.statusCode == 206)
@@ -299,14 +315,19 @@ public actor ModelDownloader {
             } else {
                 totalSize = http.expectedContentLength > 0 ? http.expectedContentLength : (expectedSize ?? 0)
             }
-            try await streamToFile(
+            let writtenSize = try await streamToFile(
                 asyncBytes: asyncBytes,
                 destURL: incompleteURL,
                 resumeOffset: isResume ? resumeOffset : 0,
                 totalSize: totalSize,
                 speedTracker: speedTracker,
                 onProgress: onProgress
             )
+            try validateCompletedDownloadSize(
+                fileName: fileName,
+                actualSize: writtenSize,
+                expectedSize: totalSize > 0 ? totalSize : expectedSize
+            )
         } else {
             throw URLError(.badServerResponse)
         }
@@ -325,7 +346,7 @@ public actor ModelDownloader {
         totalSize: Int64,
         speedTracker: DownloadSpeedTracker,
         onProgress: @Sendable (Double, Double?) -> Void
-    ) async throws {
+    ) async throws -> Int64 {
         let fileHandle: FileHandle
         if resumeOffset > 0, FileManager.default.fileExists(atPath: destURL.path) {
             fileHandle = try FileHandle(forWritingTo: destURL)
@@ -336,43 +357,57 @@ public actor ModelDownloader {
         }
         defer { try? fileHandle.close() }
 
-        var bytesWritten: Int64 = resumeOffset
-        var buffer = Data()
         let flushSize = 256 * 1024  // Flush every 256 KB
         var lastProgressUpdate = Date()
+        var bytesWritten: Int64 = resumeOffset
+        var iterator = asyncBytes.makeAsyncIterator()
+        var chunkBuffer = [UInt8](repeating: 0, count: flushSize)
 
-        for try await byte in asyncBytes {
+        while true {
             try Task.checkCancellation()
-            buffer.append(byte)
-
-            if buffer.count >= flushSize {
-                fileHandle.write(buffer)
-                bytesWritten += Int64(buffer.count)
-                buffer.removeAll(keepingCapacity: true)
 
-                speedTracker.record(totalBytes: bytesWritten)
+            var chunkCount = 0
+            while chunkCount < chunkBuffer.count,
+                  let byte = try await iterator.next() {
+                chunkBuffer[chunkCount] = byte
+                chunkCount += 1
+            }
 
-                // Throttle progress updates to ~10/sec
-                let now = Date()
-                if now.timeIntervalSince(lastProgressUpdate) >= 0.1 {
-                    lastProgressUpdate = now
-                    if totalSize > 0 {
-                        onProgress(Double(bytesWritten) / Double(totalSize), speedTracker.speedBytesPerSec)
-                    }
-                }
+            if chunkCount == 0 {
+                break
             }
-        }
 
-        // Flush remaining bytes
-        if !buffer.isEmpty {
-            fileHandle.write(buffer)
-            bytesWritten += Int64(buffer.count)
+            fileHandle.write(Data(chunkBuffer[0..<chunkCount]))
+            bytesWritten += Int64(chunkCount)
+
             speedTracker.record(totalBytes: bytesWritten)
+
+            let now = Date()
+            if now.timeIntervalSince(lastProgressUpdate) >= 0.1 {
+                lastProgressUpdate = now
+                if totalSize > 0 {
+                    onProgress(Double(bytesWritten) / Double(totalSize), speedTracker.speedBytesPerSec)
+                }
+            }
         }
 
         if totalSize > 0 {
             onProgress(Double(bytesWritten) / Double(totalSize), speedTracker.speedBytesPerSec)
         }
+        return bytesWritten
+    }
+
+    private func validateCompletedDownloadSize(
+        fileName: String,
+        actualSize: Int64,
+        expectedSize: Int64?
+    ) throws {
+        guard let expectedSize, expectedSize > 0, actualSize != expectedSize else { return }
+        throw DownloadedFileSizeMismatchError(
+            fileName: fileName,
+            expectedSize: expectedSize,
+            actualSize: actualSize
+        )
     }
 
     /// Download all model files to `ModelStorage.cacheRoot` in the Hugging Face

Sources/SwiftLM/Server.swift

@@ -1904,6 +1904,8 @@ func handleChatStreaming(
                     switch info.stopReason {
                     case .length:
                         reason = "length"
+                    case .error:
+                        reason = "error"
                     case .cancelled, .stop:
                         reason = hasToolCalls ? "tool_calls" : "stop"
                     }
@@ -2264,6 +2266,8 @@ func handleTextStreaming(
                     switch info.stopReason {
                     case .length:
                         reason = "length"
+                    case .error:
+                        reason = "error"
                     case .cancelled, .stop:
                         reason = "stop"
                     }

SwiftBuddy/SwiftBuddy/ViewModels/ServerManager.swift

@@ -48,7 +48,7 @@ private var swiftBuddyJSONHeaders: HTTPFields {
 private func swiftBuddyJSONString(_ value: String) -> String {
     guard let data = try? JSONEncoder().encode(value),
           let string = String(data: data, encoding: .utf8) else {
-        return #"""#
+        return "\"\""
     }
     return string
 }

SwiftBuddy/SwiftBuddy/Views/ModelsView.swift

@@ -12,6 +12,7 @@ struct ModelsView: View {
     @State private var showHFSearch = false
     @State private var showManagement = false
     @State private var device = DeviceProfile.current
+    @State private var deleteErrorMessage: String?
 
     private var dm: ModelDownloadManager { engine.downloadManager }
 
@@ -47,7 +48,7 @@ struct ModelsView: View {
                                 IncompleteDownloadRow(
                                     incomplete: incomplete,
                                     onResume: { dm.resumeDownload(modelId: incomplete.id) },
-                                    onDelete: { try? dm.delete(incomplete.id) }
+                                    onDelete: { deleteModel(incomplete.id) }
                                 )
                                 .padding(.horizontal)
                                 if incomplete.id != dm.incompleteDownloads.last?.id {
@@ -83,7 +84,7 @@ struct ModelsView: View {
                                     entry: entry,
                                     isActive: isActive,
                                     onLoad: { Task { await engine.load(modelId: downloaded.id) } },
-                                    onDelete: { try? dm.delete(downloaded.id) }
+                                    onDelete: { deleteModel(downloaded.id) }
                                 )
                                 .padding(.horizontal)
                                 if downloaded.id != dm.downloadedModels.last?.id {
@@ -207,6 +208,25 @@ struct ModelsView: View {
             ModelManagementView()
                 .environmentObject(engine)
         }
+        .alert(
+            "Delete Failed",
+            isPresented: Binding(
+                get: { deleteErrorMessage != nil },
+                set: { if !$0 { deleteErrorMessage = nil } }
+            )
+        ) {
+            Button("OK", role: .cancel) {}
+        } message: {
+            Text(deleteErrorMessage ?? "")
+        }
+    }
+
+    private func deleteModel(_ modelId: String) {
+        do {
+            try dm.delete(modelId)
+        } catch {
+            deleteErrorMessage = error.localizedDescription
+        }
     }
 
     // MARK: — Helpers

SwiftBuddy/SwiftBuddy/Views/RootView.swift

@@ -25,6 +25,7 @@ struct RootView: View {
     @State private var showMindPalace = false
     @State private var showTextIngestion = false
     @State private var showModelManagement = false
+    @State private var lastDownloadLogBucket: Int?
     enum Tab { case chat, models, palace, mindPalace, miner, settings }
 
     var body: some View {
@@ -51,6 +52,7 @@ struct RootView: View {
                 .sheet(isPresented: $showModelManagement) {
                     ModelManagementView()
                         .environmentObject(engine)
+                        .environmentObject(engine.downloadManager)
                 }
 
                 .onReceive(NotificationCenter.default.publisher(for: .showTextIngestion)) { _ in
@@ -69,18 +71,26 @@ struct RootView: View {
                 .onChange(of: engine.state) { oldState, newState in
                     switch newState {
                     case .idle:
+                        lastDownloadLogBucket = nil
                         ConsoleLog.shared.info("Engine idle — no model loaded")
                     case .loading:
+                        lastDownloadLogBucket = nil
                         ConsoleLog.shared.info("Loading model…")
                     case .downloading(let p, let speed):
-                        if Int(p * 100) % 25 == 0 {
-                            ConsoleLog.shared.debug("Downloading: \(Int(p * 100))% (\(speed))")
+                        let percent = Int(p * 100)
+                        let bucket = min((percent / 25) * 25, 100)
+                        if bucket != lastDownloadLogBucket, [0, 25, 50, 75, 100].contains(bucket) {
+                            lastDownloadLogBucket = bucket
+                            ConsoleLog.shared.debug("Downloading: \(percent)% (\(speed))")
                         }
                     case .ready(let modelId):
+                        lastDownloadLogBucket = nil
                         ConsoleLog.shared.info("✓ Model ready: \(modelId)")
                     case .generating:
+                        lastDownloadLogBucket = nil
                         ConsoleLog.shared.debug("Generating…")
                     case .error(let msg):
+                        lastDownloadLogBucket = nil
                         ConsoleLog.shared.error("Engine error: \(msg)")
                     }
                 }