fix #113 -- fall back to local files if offline (#133)

Author: davidkoski

Applications/StableDiffusionExample/ContentView.swift

@@ -146,12 +146,25 @@ actor ModelFactory {
         switch loadState {
         case .idle:
             let task = Task {
-                try await configuration.download { progress in
-                    if progress.fractionCompleted < 0.99 {
-                        reportProgress(
-                            .init(
-                                title: "Download", current: progress.fractionCompleted * 100,
-                                limit: 100))
+                do {
+                    try await configuration.download { progress in
+                        if progress.fractionCompleted < 0.99 {
+                            reportProgress(
+                                .init(
+                                    title: "Download", current: progress.fractionCompleted * 100,
+                                    limit: 100))
+                        }
+                    }
+                } catch {
+                    let nserror = error as NSError
+                    if nserror.domain == NSURLErrorDomain
+                        && nserror.code == NSURLErrorNotConnectedToInternet
+                    {
+                        // Internet connection appears to be offline -- fall back to loading from
+                        // the local directory
+                        reportProgress(.init(title: "Offline", current: 100, limit: 100))
+                    } else {
+                        throw error
                     }
                 }
 

Libraries/LLM/Load.swift

@@ -31,6 +31,15 @@ func prepareModelDirectory(
         // an authorizationRequired means (typically) that the named repo doesn't exist on
         // on the server so retry with local only configuration
         return configuration.modelDirectory(hub: hub)
+    } catch {
+        let nserror = error as NSError
+        if nserror.domain == NSURLErrorDomain && nserror.code == NSURLErrorNotConnectedToInternet {
+            // Error Domain=NSURLErrorDomain Code=-1009 "The Internet connection appears to be offline."
+            // fall back to the local directory
+            return configuration.modelDirectory(hub: hub)
+        } else {
+            throw error
+        }
     }
 }
 

Libraries/LLM/Tokenizer.swift

@@ -21,8 +21,25 @@ func loadTokenizerConfig(configuration: ModelConfiguration, hub: HubApi) async t
 
     switch configuration.id {
     case .id(let id):
-        config = LanguageModelConfigurationFromHub(
-            modelName: configuration.tokenizerId ?? id, hubApi: hub)
+        do {
+            // the load can fail (async when we try to use it)
+            let loaded = LanguageModelConfigurationFromHub(
+                modelName: configuration.tokenizerId ?? id, hubApi: hub)
+            _ = try await loaded.tokenizerConfig
+            config = loaded
+        } catch {
+            let nserror = error as NSError
+            if nserror.domain == NSURLErrorDomain
+                && nserror.code == NSURLErrorNotConnectedToInternet
+            {
+                // Internet connection appears to be offline -- fall back to loading from
+                // the local directory
+                config = LanguageModelConfigurationFromHub(
+                    modelFolder: configuration.modelDirectory(hub: hub), hubApi: hub)
+            } else {
+                throw error
+            }
+        }
     case .directory(let directory):
         config = LanguageModelConfigurationFromHub(modelFolder: directory, hubApi: hub)
     }

mlx-swift-examples.xcodeproj/xcshareddata/xcschemes/StableDiffusionExample.xcscheme

@@ -0,0 +1,78 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Scheme
+   LastUpgradeVersion = "1600"
+   version = "1.7">
+   <BuildAction
+      parallelizeBuildables = "YES"
+      buildImplicitDependencies = "YES"
+      buildArchitectures = "Automatic">
+      <BuildActionEntries>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "C36BF0002BC5CE55002D4AFE"
+               BuildableName = "StableDiffusionExample.app"
+               BlueprintName = "StableDiffusionExample"
+               ReferencedContainer = "container:mlx-swift-examples.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
+      </BuildActionEntries>
+   </BuildAction>
+   <TestAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      shouldAutocreateTestPlan = "YES">
+   </TestAction>
+   <LaunchAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      launchStyle = "0"
+      useCustomWorkingDirectory = "NO"
+      ignoresPersistentStateOnLaunch = "NO"
+      debugDocumentVersioning = "YES"
+      debugServiceExtension = "internal"
+      allowLocationSimulation = "YES">
+      <BuildableProductRunnable
+         runnableDebuggingMode = "0">
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "C36BF0002BC5CE55002D4AFE"
+            BuildableName = "StableDiffusionExample.app"
+            BlueprintName = "StableDiffusionExample"
+            ReferencedContainer = "container:mlx-swift-examples.xcodeproj">
+         </BuildableReference>
+      </BuildableProductRunnable>
+   </LaunchAction>
+   <ProfileAction
+      buildConfiguration = "Release"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      savedToolIdentifier = ""
+      useCustomWorkingDirectory = "NO"
+      debugDocumentVersioning = "YES">
+      <BuildableProductRunnable
+         runnableDebuggingMode = "0">
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "C36BF0002BC5CE55002D4AFE"
+            BuildableName = "StableDiffusionExample.app"
+            BlueprintName = "StableDiffusionExample"
+            ReferencedContainer = "container:mlx-swift-examples.xcodeproj">
+         </BuildableReference>
+      </BuildableProductRunnable>
+   </ProfileAction>
+   <AnalyzeAction
+      buildConfiguration = "Debug">
+   </AnalyzeAction>
+   <ArchiveAction
+      buildConfiguration = "Release"
+      revealArchiveInOrganizer = "YES">
+   </ArchiveAction>
+</Scheme>