Refs #36532 -- Optimized CSP decorator async checking.

The previous approach created both sync and async wrappers before
checking which one was needed. Checking first reduces about 1 microsecond
off each decorator application.

1 files changed, 9 insertions, 7 deletions

diff --git a/django/views/decorators/csp.py b/django/views/decorators/csp.py
index 1c537fe1f2..c6ee54fea4 100644
--- a/django/views/decorators/csp.py
+++ b/django/views/decorators/csp.py
@@ -9,11 +9,15 @@ def _make_csp_decorator(config_attr_name, config_attr_value):
         raise TypeError("CSP config should be a mapping.")
 
     def decorator(view_func):
-        @wraps(view_func)
-        async def _wrapped_async_view(request, *args, **kwargs):
-            response = await view_func(request, *args, **kwargs)
-            setattr(response, config_attr_name, config_attr_value)
-            return response
+        if iscoroutinefunction(view_func):
+
+            @wraps(view_func)
+            async def _wrapped_async_view(request, *args, **kwargs):
+                response = await view_func(request, *args, **kwargs)
+                setattr(response, config_attr_name, config_attr_value)
+                return response
+
+            return _wrapped_async_view
 
         @wraps(view_func)
         def _wrapped_sync_view(request, *args, **kwargs):
@@ -21,8 +25,6 @@ def _make_csp_decorator(config_attr_name, config_attr_value):
             setattr(response, config_attr_name, config_attr_value)
             return response
 
-        if iscoroutinefunction(view_func):
-            return _wrapped_async_view
         return _wrapped_sync_view
 
     return decorator