(WIP) modernize the import hook

Implement a meta path loader instead
pythonnet · filmor · Jun 18, 2021 · Jan 15, 2021 · Jan 15, 2021 · Jan 15, 2021
commit a321daa0147a49984a1df027df9d3f6104e77950
diff --git a/src/runtime/assemblymanager.cs b/src/runtime/assemblymanager.cs
@@ -37,6 +37,9 @@ internal class AssemblyManager
         // modified from event handlers below, potentially triggered from different .NET threads
         private static ConcurrentQueue<Assembly> assemblies;
         internal static List<string> pypath;
+
+        // Triggered when a new namespace is added to the namespaces dictionary
+        public static event Action<string> namespaceAdded;
 
         private AssemblyManager()
         {
@@ -284,6 +287,17 @@ internal static void ScanAssembly(Assembly assembly)
                 if (ns != null)
                 {
                     namespaces[ns].TryAdd(assembly, string.Empty);
+                    try
+                    {
+                        namespaceAdded?.Invoke(ns);
+                    }
+                    catch (Exception e)
+                    {
+                        // For some reason, exceptions happening here does... nothing.
+                        // Even System.AccessViolationExceptions gets ignored.
+                        Console.WriteLine($"Namespace added callback failed with: {e}");
+                        throw;
+                    }
                 }
 
                 if (ns != null && t.IsGenericTypeDefinition)
@@ -312,6 +326,15 @@ public static bool IsValidNamespace(string name)
             return !string.IsNullOrEmpty(name) && namespaces.ContainsKey(name);
         }
 
+        /// <summary>
+        /// Returns an IEnumerable<string> containing the namepsaces exported
+        /// by loaded assemblies in the current app domain.
+        /// </summary>
+        public static IEnumerable<string> GetNamespaces ()
+        {
+            return namespaces.Keys;
+        }
+
         /// <summary>
         /// Returns list of assemblies that declare types in a given namespace
         /// </summary>

diff --git a/src/runtime/extensiontype.cs b/src/runtime/extensiontype.cs
@@ -83,7 +83,7 @@ public static int tp_setattro(IntPtr ob, IntPtr key, IntPtr val)
             {
                 message = "readonly attribute";
             }
-            Exceptions.SetError(Exceptions.TypeError, message);
+            Exceptions.SetError(Exceptions.AttributeError, message);
             return -1;
         }