fix(space): avoid deleting Gradio cache and tmp_gradio paths still in UI

app.py

@@ -141,10 +141,25 @@ MAX_SEED = np.iinfo(np.int32).max
 # Session helpers
 # ---------------------------------------------------------------------------
 
+_SESSION_LAST_TOUCH: Dict[str, float] = {}
+_SESSION_TOUCH_LOCK = threading.Lock()
+
+
+def _session_touch(session_id: str) -> None:
+    with _SESSION_TOUCH_LOCK:
+        _SESSION_LAST_TOUCH[session_id] = time.time()
+
+
+def _session_forget(session_id: str) -> None:
+    with _SESSION_TOUCH_LOCK:
+        _SESSION_LAST_TOUCH.pop(session_id, None)
+
+
 def ensure_session_dir(req: Optional[gr.Request]) -> Path:
     session_id = getattr(req, "session_hash", None) or "shared"
     d = CACHE_DIR / str(session_id)
     d.mkdir(parents=True, exist_ok=True)
+    _session_touch(session_id)
     return d
 
 
@@ -159,8 +174,10 @@ def clear_session_dir(req: Optional[gr.Request]) -> str:
 
 
 def end_session(req: gr.Request):
-    d = ensure_session_dir(req)
+    session_id = getattr(req, "session_hash", None) or "shared"
+    d = CACHE_DIR / str(session_id)
     shutil.rmtree(d, ignore_errors=True)
+    _session_forget(session_id)
 
 
 def _session_dir_latest_mtime(path: Path) -> float:
@@ -183,12 +200,14 @@ def _session_dir_latest_mtime(path: Path) -> float:
 
 
 def prune_tmp_gradio_sessions(max_age_s: int) -> int:
-    """Delete CACHE_DIR/<session> trees with no nested file activity for max_age_s. Returns removed count."""
+    """Delete CACHE_DIR/<session> when both API idle and on-disk files are older than max_age_s."""
 
     if max_age_s <= 0 or not CACHE_DIR.is_dir():
         return 0
     now = time.time()
     removed = 0
+    with _SESSION_TOUCH_LOCK:
+        touch_snap = dict(_SESSION_LAST_TOUCH)
     try:
         entries = list(CACHE_DIR.iterdir())
     except OSError:
@@ -196,10 +215,15 @@ def prune_tmp_gradio_sessions(max_age_s: int) -> int:
     for p in entries:
         if not p.is_dir():
             continue
+        sid = p.name
         try:
-            if now - _session_dir_latest_mtime(p) < max_age_s:
+            last_api = touch_snap.get(sid)
+            latest_file = _session_dir_latest_mtime(p)
+            last_seen = max(last_api or 0.0, latest_file)
+            if now - last_seen < max_age_s:
                 continue
             shutil.rmtree(p, ignore_errors=True)
+            _session_forget(sid)
             removed += 1
         except OSError:
             continue
@@ -221,7 +245,7 @@ def start_tmp_gradio_pruner() -> None:
         if _tmp_pruner_started:
             return
         _tmp_pruner_started = True
-    max_age = int(os.environ.get("NEAR_TMP_GRADIO_MAX_AGE_S", str(6 * 3600)))
+    max_age = int(os.environ.get("NEAR_TMP_GRADIO_MAX_AGE_S", str(48 * 3600)))
 
     def _loop() -> None:
         while True:
@@ -848,7 +872,8 @@ def build_app() -> gr.Blocks:
         ),
         title="NeAR",
         css=CUSTOM_CSS,
-        delete_cache=(600, 600),
+        # (600, 600) deletes Gradio /tmp/gradio uploads in ~10m while the UI may still reference paths.
+        delete_cache=None,
         fill_width=True,
     ) as demo:
         asset_state = gr.State({})