feat(space): background prune stale tmp_gradio session dirs by age

app.py

@@ -34,6 +34,7 @@ print(
 
 import shutil
 import threading
+import time
 from pathlib import Path
 from typing import Any, Dict, Optional
 
@@ -162,6 +163,79 @@ def end_session(req: gr.Request):
     shutil.rmtree(d, ignore_errors=True)
 
 
+def _session_dir_latest_mtime(path: Path) -> float:
+    """Latest mtime among path and all nested files (best-effort for 'last activity')."""
+
+    try:
+        latest = path.stat().st_mtime
+    except OSError:
+        return 0.0
+    try:
+        for child in path.rglob("*"):
+            if child.is_file():
+                try:
+                    latest = max(latest, child.stat().st_mtime)
+                except OSError:
+                    pass
+    except OSError:
+        pass
+    return latest
+
+
+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."""
+
+    if max_age_s <= 0 or not CACHE_DIR.is_dir():
+        return 0
+    now = time.time()
+    removed = 0
+    try:
+        entries = list(CACHE_DIR.iterdir())
+    except OSError:
+        return 0
+    for p in entries:
+        if not p.is_dir():
+            continue
+        try:
+            if now - _session_dir_latest_mtime(p) < max_age_s:
+                continue
+            shutil.rmtree(p, ignore_errors=True)
+            removed += 1
+        except OSError:
+            continue
+    return removed
+
+
+_tmp_pruner_started = False
+_tmp_pruner_lock = threading.Lock()
+
+
+def start_tmp_gradio_pruner() -> None:
+    """Background prune of tmp_gradio session dirs (disk, not RAM). Configurable via env."""
+
+    global _tmp_pruner_started
+    interval = int(os.environ.get("NEAR_TMP_PRUNE_INTERVAL_S", "900"))
+    if interval <= 0:
+        return
+    with _tmp_pruner_lock:
+        if _tmp_pruner_started:
+            return
+        _tmp_pruner_started = True
+    max_age = int(os.environ.get("NEAR_TMP_GRADIO_MAX_AGE_S", str(6 * 3600)))
+
+    def _loop() -> None:
+        while True:
+            try:
+                n = prune_tmp_gradio_sessions(max_age)
+                if n:
+                    print(f"[NeAR] tmp_gradio prune: removed {n} stale session dir(s)", flush=True)
+            except Exception as exc:
+                print(f"[NeAR] tmp_gradio prune error: {exc}", flush=True)
+            time.sleep(interval)
+
+    threading.Thread(target=_loop, daemon=True, name="near-tmp-prune").start()
+
+
 def get_file_path(file_obj: Any) -> Optional[str]:
     if file_obj is None:
         return None
@@ -1110,6 +1184,7 @@ def build_app() -> gr.Blocks:
 
 demo = build_app()
 demo.queue(max_size=8)
+start_tmp_gradio_pruner()
 
 # ---------------------------------------------------------------------------
 # Entry point