very simple strong-cache on model list (#4969)

* very simple strong-cache on model list

* store the cache after validation too

* only cache object_info for now

* use a 'with' context

folder_paths.py

@@ -46,6 +46,36 @@ user_directory = os.path.join(os.path.dirname(os.path.realpath(__file__)), "user
 
 filename_list_cache: dict[str, tuple[list[str], dict[str, float], float]] = {}
 
+class CacheHelper:
+    """
+    Helper class for managing file list cache data.
+    """
+    def __init__(self):
+        self.cache: dict[str, tuple[list[str], dict[str, float], float]] = {}
+        self.active = False
+
+    def get(self, key: str, default=None) -> tuple[list[str], dict[str, float], float]:
+        if not self.active:
+            return default
+        return self.cache.get(key, default)
+    
+    def set(self, key: str, value: tuple[list[str], dict[str, float], float]) -> None:
+        if self.active:
+            self.cache[key] = value
+
+    def clear(self):
+        self.cache.clear()
+
+    def __enter__(self):
+        self.active = True
+        return self
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        self.active = False
+        self.clear()
+
+cache_helper = CacheHelper()
+
 extension_mimetypes_cache = {
     "webp" : "image",
 }
@@ -257,6 +287,10 @@ def get_filename_list_(folder_name: str) -> tuple[list[str], dict[str, float], f
     return sorted(list(output_list)), output_folders, time.perf_counter()
 
 def cached_filename_list_(folder_name: str) -> tuple[list[str], dict[str, float], float] | None:
+    strong_cache = cache_helper.get(folder_name)
+    if strong_cache is not None:
+        return strong_cache
+    
     global filename_list_cache
     global folder_names_and_paths
     folder_name = map_legacy(folder_name)
@@ -285,6 +319,7 @@ def get_filename_list(folder_name: str) -> list[str]:
         out = get_filename_list_(folder_name)
         global filename_list_cache
         filename_list_cache[folder_name] = out
+    cache_helper.set(folder_name, out)
     return list(out[0])
 
 def get_save_image_path(filename_prefix: str, output_dir: str, image_width=0, image_height=0) -> tuple[str, str, int, str, str]:

server.py

@@ -552,14 +552,15 @@ class PromptServer():
 
         @routes.get("/object_info")
         async def get_object_info(request):
-            out = {}
-            for x in nodes.NODE_CLASS_MAPPINGS:
-                try:
-                    out[x] = node_info(x)
-                except Exception as e:
-                    logging.error(f"[ERROR] An error occurred while retrieving information for the '{x}' node.")
-                    logging.error(traceback.format_exc())
-            return web.json_response(out)
+            with folder_paths.cache_helper:
+                out = {}
+                for x in nodes.NODE_CLASS_MAPPINGS:
+                    try:
+                        out[x] = node_info(x)
+                    except Exception as e:
+                        logging.error(f"[ERROR] An error occurred while retrieving information for the '{x}' node.")
+                        logging.error(traceback.format_exc())
+                return web.json_response(out)
 
         @routes.get("/object_info/{node_class}")
         async def get_object_info_node(request):