enhance session management with error handling for session start and end

app.py

@@ -54,13 +54,24 @@ _trellis_pipeline = None
 
 
 def start_session(req: gr.Request):
-    user_dir = os.path.join(TMP_DIR, str(req.session_hash))
-    os.makedirs(user_dir, exist_ok=True)
+    """Create a temporary directory for the user session"""
+    try:
+        user_dir = os.path.join(TMP_DIR, str(req.session_hash))
+        os.makedirs(user_dir, exist_ok=True)
+        print(f"Session started: {req.session_hash}")
+    except Exception as e:
+        print(f"Error starting session: {str(e)}")
     
     
 def end_session(req: gr.Request):
-    user_dir = os.path.join(TMP_DIR, str(req.session_hash))
-    shutil.rmtree(user_dir)
+    """Clean up the temporary directory when the session ends"""
+    try:
+        user_dir = os.path.join(TMP_DIR, str(req.session_hash))
+        if os.path.exists(user_dir):
+            shutil.rmtree(user_dir)
+            print(f"Session ended: {req.session_hash}")
+    except Exception as e:
+        print(f"Error ending session: {str(e)}")
 
 
 @spaces.GPU()
@@ -585,8 +596,7 @@ def create_interface():
             outputs=[download_gs]
         )
 
-    return demo
-
+    return demo 
 
 if __name__ == "__main__":
     # Initialize models if PRELOAD_MODELS is True