SKA-224: Delete temporarily extracted FMUs

* If there is a folder with the extracted FMU in the same directory as the FMU, this extracted content will be used and remains there after the FMU Importer stops.
* Otherwise, the FMU is now extracted to a temporary directory. This directory and its contents are deleted after the simulation run.

CHANGELOG.md

@@ -9,6 +9,9 @@ The format is based on `Keep a Changelog (http://keepachangelog.com/en/1.0.0/) <
 ### Changed
 
 * If the value of an enumeration-typed variable is set, strings are now considered referring to an enumerator's name, whereas integers refer to an enumerators' value.
+* Temporarily extracted FMUs are now deleted by default
+    * If there is a folder with the extracted FMU in the same directory as the FMU, this extracted content will be used and remains there after the FMU Importer stops.
+    * Otherwise, the FMU is now extracted to a temporary directory. This directory and its contents are deleted after the simulation run.
 
 ## [1.2.0] - 2024-03-28
 

FmuImporter/FmiBridge/Binding/BindingFactory.cs

@@ -5,14 +5,15 @@ namespace Fmi.Binding;
 
 public static class BindingFactory
 {
-  public static IFmiBindingCommon CreateBinding(FmiVersions fmiVersion, string fmuPath)
+  public static IFmiBindingCommon CreateBinding(
+    FmiVersions fmiVersion, string fmuPath, Action<LogSeverity, string> logCallback)
   {
     switch (fmiVersion)
     {
       case FmiVersions.Fmi2:
-        return new Fmi2Binding(fmuPath);
+        return new Fmi2Binding(fmuPath, logCallback);
       case FmiVersions.Fmi3:
-        return new Fmi3Binding(fmuPath);
+        return new Fmi3Binding(fmuPath, logCallback);
       default:
         throw new ArgumentOutOfRangeException(nameof(fmiVersion), fmiVersion, null);
     }

FmuImporter/FmiBridge/Binding/Fmi2Binding.cs

@@ -114,7 +114,7 @@ private static string OsPath
 
   private static readonly AutoResetEvent WaitForDoStepEvent = new AutoResetEvent(false);
 
-  public Fmi2Binding(string fmuPath) : base(fmuPath, OsPath)
+  public Fmi2Binding(string fmuPath, Action<LogSeverity, string> logCallback) : base(fmuPath, OsPath, logCallback)
   {
     // Common Functions
     SetDelegate(out _fmi2SetDebugLogging);

FmuImporter/FmiBridge/Binding/Fmi3Binding.cs

@@ -48,7 +48,7 @@ private static string OsPath
     }
   }
 
-  public Fmi3Binding(string fmuPath) : base(fmuPath, OsPath)
+  public Fmi3Binding(string fmuPath, Action<LogSeverity, string> logCallback) : base(fmuPath, OsPath, logCallback)
   {
     // Common functions
     SetDelegate(out _fmi3InstantiateCoSimulation);

FmuImporter/FmiBridge/Binding/FmiBindingBase.cs

@@ -23,15 +23,43 @@ internal abstract class FmiBindingBase : IDisposable, IFmiBindingCommon
 
   public ModelDescription ModelDescription { get; }
 
-  public string ExtractedFolderPath { get; }
+  private readonly string _extractedFolderPath;
+
+  public string ExtractedFolderPath
+  {
+    get
+    {
+      return _extractedFolderPath;
+    }
+  }
+
   public string FullFmuLibPath { get; }
 
   private IntPtr DllPtr { set; get; }
 
+  private bool _isTemporary;
+
+  internal bool IsTemporary
+  {
+    get
+    {
+      return _isTemporary;
+    }
+    set
+    {
+      _isTemporary = value;
+    }
+  }
+
   // ctor
-  protected FmiBindingBase(string fmuPath, string osDependentPath)
+  protected FmiBindingBase(string fmuPath, string osDependentPath, Action<LogSeverity, string> logCallback)
   {
-    ExtractedFolderPath = ModelLoader.ExtractFmu(fmuPath);
+    _loggerAction = logCallback;
+    ModelLoader.ExtractFmu(fmuPath, out _extractedFolderPath, out _isTemporary);
+    if (IsTemporary)
+    {
+      Log(LogSeverity.Debug, $"Temporarily extracted the FMU to '{_extractedFolderPath}'.");
+    }
 
     ModelDescription = InitializeModelDescription(ExtractedFolderPath);
 
@@ -49,6 +77,32 @@ protected FmiBindingBase(string fmuPath, string osDependentPath)
 
   private void ReleaseUnmanagedResources()
   {
+    var failCounter = 10;
+    if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+    {
+      while (NativeMethods.FreeLibrary(DllPtr) && failCounter > 0)
+      {
+        --failCounter;
+      }
+    }
+    else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux) || RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
+    {
+      while (NativeMethods.dlclose(DllPtr) != 0 && failCounter > 0)
+      {
+        --failCounter;
+      }
+    }
+    else
+    {
+      throw new NotSupportedException();
+    }
+
+    // if DLL was freed successfully and FMU was extracted to temporary folder, delete that folder and its content
+    if (failCounter > 0 && IsTemporary)
+    {
+      var dir = Directory.GetParent(ExtractedFolderPath) ?? new DirectoryInfo(ExtractedFolderPath);
+      dir.Delete(true);
+    }
   }
 
   private bool _disposedValue;
@@ -235,10 +289,5 @@ protected void Log(LogSeverity severity, string message)
     _loggerAction?.Invoke(severity, message);
   }
 
-  private Action<LogSeverity, string>? _loggerAction;
-
-  public void SetLoggerCallback(Action<LogSeverity, string> callback)
-  {
-    _loggerAction = callback;
-  }
+  private readonly Action<LogSeverity, string>? _loggerAction;
 }

FmuImporter/FmiBridge/Binding/IFmiBindingCommon.cs

@@ -26,6 +26,4 @@ public void DoStep(
   public void FreeInstance();
 
   public FmiVersions GetFmiVersion();
-
-  public void SetLoggerCallback(Action<LogSeverity, string> callback);
 }

FmuImporter/FmiBridge/FmiModel/ModelLoader.cs

@@ -10,7 +10,7 @@ namespace Fmi.FmiModel;
 
 public class ModelLoader
 {
-  internal static string ExtractFmu(string fmuPath)
+  internal static void ExtractFmu(string fmuPath, out string extractedPath, out bool isTemporary)
   {
     // check if the directory exists
     var targetFolderPath =
@@ -21,23 +21,34 @@ internal static string ExtractFmu(string fmuPath)
     //  $"SilKitImporter_{Path.GetFileNameWithoutExtension(fmuPath)}");
     if (Directory.Exists(targetFolderPath) && Directory.EnumerateFileSystemEntries(targetFolderPath).Any())
     {
+      isTemporary = false;
+      extractedPath = targetFolderPath;
       // directory exists and has entries -> skip extraction
-      return targetFolderPath;
+      return;
     }
 
+    var tempDirectory = CreateTempDirectory();
+
     var dir = Directory.CreateDirectory(
-      $"{Path.GetDirectoryName(fmuPath)}/{Path.GetFileNameWithoutExtension(fmuPath)}");
+      $"{tempDirectory}/{Path.GetFileNameWithoutExtension(fmuPath)}");
 
     ZipFile.ExtractToDirectory(fmuPath, dir.FullName);
-    return dir.FullName;
+    isTemporary = true;
+    extractedPath = dir.FullName;
   }
 
-  internal static void RemoveExtractedFmu(string fmuPath)
+  private static string CreateTempDirectory()
   {
-    var dir = $"{Path.GetDirectoryName(fmuPath)}/{Path.GetFileNameWithoutExtension(fmuPath)}";
-    if (Directory.Exists(dir))
+    var tempDirectory = Path.Combine(Path.GetTempPath(), Path.GetRandomFileName());
+    if (File.Exists(tempDirectory))
+    {
+      // try again
+      return CreateTempDirectory();
+    }
+    else
     {
-      Directory.Delete(dir, true);
+      Directory.CreateDirectory(tempDirectory);
+      return tempDirectory;
     }
   }
 

FmuImporter/FmuImporter/Fmu/FmuEntity.cs

@@ -29,12 +29,12 @@ public enum FmuSuperStates
 
   public event FmiLog? OnFmuLog;
 
-  public FmuEntity(string fmuPath)
+  public FmuEntity(string fmuPath, FmiLog fmiLogCallback)
   {
     FmiVersion = ModelLoader.FindFmiVersion(fmuPath);
+    OnFmuLog = fmiLogCallback;
 
-    Binding = BindingFactory.CreateBinding(FmiVersion, fmuPath);
-    Binding.SetLoggerCallback(RaiseOnFmuLogEvent);
+    Binding = BindingFactory.CreateBinding(FmiVersion, fmuPath, RaiseOnFmuLogEvent);
     ModelDescription = Binding.ModelDescription;
   }
 

FmuImporter/FmuImporter/FmuImporter.cs

@@ -98,7 +98,7 @@ public FmuImporter(
       throw;
     }
 
-    FmuEntity = new FmuEntity(fmuPath);
+    FmuEntity = new FmuEntity(fmuPath, FmuEntity_OnFmuLog);
 
     try
     {
@@ -119,9 +119,6 @@ public FmuImporter(
         _configuredStructuralParameters.Add(myStructParam, param!);
       }
 
-      // Register logger callback
-      FmuEntity.OnFmuLog += FmuEntity_OnFmuLog;
-
       // Initialize FMU
       FmuEntity.PrepareFmu(ApplyParameterConfiguration, ApplyParameterConfiguration);