misc: add a profiling middleware

src/ants_hub/middleware.py

@@ -0,0 +1,33 @@
+# ANTS-Hub - Copyright (C) Entr'ouvert
+
+import cProfile
+import pstats
+import time
+
+from django.conf import settings
+
+
+def profile_middleware(get_response):
+    if not settings.PROFILE_FILE:
+        return get_response
+
+    start = time.time()
+    pr = cProfile.Profile()
+
+    def middleware(request):
+        nonlocal start, pr
+
+        pr.enable()
+        try:
+            return get_response(request)
+        finally:
+            pr.disable()
+            # dump profile every 20 seconds
+            if time.time() - start > 20:
+                start = time.time()
+                with open(settings.PROFILE_FILE, 'w') as fd:
+                    sortby = pstats.SortKey.CUMULATIVE
+                    ps = pstats.Stats(pr, stream=fd).sort_stats(sortby)
+                    ps.print_stats()
+
+    return middleware

src/ants_hub/settings.py

@@ -20,8 +20,11 @@ INSTALLED_APPS = [
 ]
 
 MIDDLEWARE = [
+    'ants_hub.middleware.profile_middleware',
 ]
 
+PROFILE_FILE = None
+
 SILENCED_SYSTEM_CHECKS = [
     'admin.E408',
     'admin.E409',