add rate limiter

main.py

@@ -2,7 +2,9 @@ from typing import List, Dict, Any
 import os
 import shutil
 import uuid
-from fastapi import FastAPI, Request, UploadFile, File, HTTPException
+import time
+from functools import wraps
+from fastapi import FastAPI, Request, UploadFile, File, HTTPException, status
 from fastapi.responses import HTMLResponse, JSONResponse
 from fastapi.templating import Jinja2Templates
 from fastapi.staticfiles import StaticFiles
@@ -48,9 +50,8 @@ app.mount("/static", StaticFiles(directory="./static", html=True), name="static"
 app.add_middleware(SessionMiddleware, secret_key="audio-annotator-application")
 templates = Jinja2Templates(directory="./templates")
 
-# --- Utility Functions ---
-
 
+# --- Utility Functions ---
 def load_data_for_index(user_id: int, index: int) -> Dict[str, Any]:
     """Helper to safely fetch data for a given index."""
     if not ANNOTATION_DATA[user_id]:
@@ -88,11 +89,31 @@ def serve_index_html(request: Request):
     except FileNotFoundError:
         return HTMLResponse(content="<h1>Server Error: index.html not found.</h1>", status_code=500)
 
+def rate_limited(max_calls: int, time_frame:int):
+    """
+    :param max_calls: Maximum number of calls allowed in the specified time frame.
+    :param time_frame: The time frame (in seconds) for which the limit applies.
+    :return: Decorator function.
+    """
+    def decorator(func):
+        calls = []
+
+        @wraps(func)
+        async def wrapper(request: Request, *args, **kwargs):
+            now = time.time()
+            calls_in_time_frame = [call for call in calls if call > now - time_frame]
+            if len(calls_in_time_frame) > max_calls:
+                raise HTTPException(status_code=status.HTTP_429_TOO_MANY_REQUESTS, detail="Rate limit exceeded.")
+            calls.append(now)
+            return await func(request, *args, **kwargs)
+        return wrapper
+    return decorator
 
 # --- Routes ---
 
 
 @app.get("/")
+@rate_limited(max_calls=10, time_frame=60)
 async def index(request: Request):
     """Serves the main application page by reading index.html."""
     return serve_index_html(request)