Upload New File

stbi/Lib/site-packages/asgiref/compatibility.py

+import asyncio
+import inspect
+
+
+def is_double_callable(application):
+    """
+    Tests to see if an application is a legacy-style (double-callable) application.
+    """
+    # Look for a hint on the object first
+    if getattr(application, "_asgi_single_callable", False):
+        return False
+    if getattr(application, "_asgi_double_callable", False):
+        return True
+    # Uninstanted classes are double-callable
+    if inspect.isclass(application):
+        return True
+    # Instanted classes depend on their __call__
+    if hasattr(application, "__call__"):
+        # We only check to see if its __call__ is a coroutine function -
+        # if it's not, it still might be a coroutine function itself.
+        if asyncio.iscoroutinefunction(application.__call__):
+            return False
+    # Non-classes we just check directly
+    return not asyncio.iscoroutinefunction(application)
+
+
+def double_to_single_callable(application):
+    """
+    Transforms a double-callable ASGI application into a single-callable one.
+    """
+
+    async def new_application(scope, receive, send):
+        instance = application(scope)
+        return await instance(receive, send)
+
+    return new_application
+
+
+def guarantee_single_callable(application):
+    """
+    Takes either a single- or double-callable application and always returns it
+    in single-callable style. Use this to add backwards compatibility for ASGI
+    2.0 applications to your server/test harness/etc.
+    """
+    if is_double_callable(application):
+        application = double_to_single_callable(application)
+    return application