allow add middleware after app has started

this should completely fix "Cannot add middleware after an application has started" which can occur due to a race condition

.github/workflows/on_pull_request.yaml

@@ -22,7 +22,7 @@ jobs:
       - name: Install Ruff
         run: pip install ruff==0.3.3
       - name: Run Ruff
-        run: ruff .
+        run: ruff check .
   lint-js:
     name: eslint
     runs-on: ubuntu-latest

html/footer.html

@@ -1,5 +1,5 @@
 <div>
-        <a href="{api_docs}">API</a>
+        <a href="{api_docs}" target="_blank">API</a>
          • 
         <a href="https://github.com/AUTOMATIC1111/stable-diffusion-webui">GitHub</a>
          • 

modules/initialize.py

@@ -50,6 +50,7 @@ def check_versions():
 
 def initialize():
     from modules import initialize_util
+    initialize_util.allow_add_middleware_after_start()
     initialize_util.fix_torch_version()
     initialize_util.fix_pytorch_lightning()
     initialize_util.fix_asyncio_event_loop_policy()

modules/initialize_util.py

@@ -5,6 +5,8 @@ import sys
 import re
 
 from modules.timer import startup_timer
+from modules import patches
+from functools import wraps
 
 
 def gradio_server_name():
@@ -191,11 +193,8 @@ def configure_opts_onchange():
 
 def setup_middleware(app):
     from starlette.middleware.gzip import GZipMiddleware
-
-    app.middleware_stack = None  # reset current middleware to allow modifying user provided list
     app.add_middleware(GZipMiddleware, minimum_size=1000)
     configure_cors_middleware(app)
-    app.build_middleware_stack()  # rebuild middleware stack on-the-fly
 
 
 def configure_cors_middleware(app):
@@ -213,3 +212,38 @@ def configure_cors_middleware(app):
         cors_options["allow_origin_regex"] = cmd_opts.cors_allow_origins_regex
     app.add_middleware(CORSMiddleware, **cors_options)
 
+
+def allow_add_middleware_after_start():
+    from starlette.applications import Starlette
+
+    def add_middleware_wrapper(func):
+        """Patch Starlette.add_middleware to allow for middleware to be added after the app has started
+
+        Starlette.add_middleware raises RuntimeError("Cannot add middleware after an application has started") if middleware_stack is not None.
+        We can force add new middleware by first setting middleware_stack to None, then adding the middleware.
+        When middleware_stack is None, it will rebuild the middleware_stack on the next request (Lazily build middleware stack).
+
+        If packages are updated in the future, things may break, so we have two ways to add middleware after the app has started:
+        the first way is to just set middleware_stack to None and then retry
+        the second manually insert the middleware into the user_middleware list without calling add_middleware
+        """
+
+        @wraps(func)
+        def wrapper(self, *args, **kwargs):
+            res = None
+            try:
+                res = func(self, *args, **kwargs)
+            except RuntimeError as _:
+                try:
+                    self.middleware_stack = None
+                    res = func(self, *args, **kwargs)
+                except RuntimeError as e:
+                    print(f'Warning: "{e}", Retrying...')
+                    from starlette.middleware import Middleware
+                    self.user_middleware.insert(0, Middleware(*args, **kwargs))
+                self.middleware_stack = None  # ensure middleware_stack in the event of concurrent requests
+            return res
+
+        return wrapper
+
+    patches.patch(__name__, obj=Starlette, field="add_middleware", replacement=add_middleware_wrapper(Starlette.add_middleware))

modules/launch_utils.py

@@ -43,9 +43,7 @@ def check_python_version():
         supported_minors = [7, 8, 9, 10, 11]
 
     if not (major == 3 and minor in supported_minors):
-        import modules.errors
+        errors.print_error_explanation(f"""
-
-        modules.errors.print_error_explanation(f"""
 INCOMPATIBLE PYTHON VERSION
 
 This program is tested with 3.10.6 Python, but you have {major}.{minor}.{micro}.

modules/shared_items.py

@@ -125,7 +125,7 @@ def ui_reorder_categories():
 
 def callbacks_order_settings():
     options = {
-        "sd_vae_explanation": OptionHTML("""
+        "callbacks_order_explanation": OptionHTML("""
     For categories below, callbacks added to dropdowns happen before others, in order listed.
     """),
 

scripts/postprocessing_codeformer.py

@@ -29,6 +29,10 @@ class ScriptPostprocessingCodeFormer(scripts_postprocessing.ScriptPostprocessing
         res = Image.fromarray(restored_img)
 
         if codeformer_visibility < 1.0:
+            if pp.image.size != res.size:
+                res = res.resize(pp.image.size)
+            if pp.image.mode != res.mode:
+                res = res.convert(pp.image.mode)
             res = Image.blend(pp.image, res, codeformer_visibility)
 
         pp.image = res

scripts/postprocessing_gfpgan.py

@@ -26,6 +26,10 @@ class ScriptPostprocessingGfpGan(scripts_postprocessing.ScriptPostprocessing):
         res = Image.fromarray(restored_img)
 
         if gfpgan_visibility < 1.0:
+            if pp.image.size != res.size:
+                res = res.resize(pp.image.size)
+            if pp.image.mode != res.mode:
+                res = res.convert(pp.image.mode)
             res = Image.blend(pp.image, res, gfpgan_visibility)
 
         pp.image = res