Add system cache clearing action

webui/components/system_settings.py

@@ -4,8 +4,54 @@ import shutil
 from loguru import logger
 
 from app.config import config
+from app.services.llm.unified_service import UnifiedLLMService
 from app.utils import ffmpeg_detector, ffmpeg_utils
-from app.utils.utils import storage_dir
+from app.utils.utils import clear_keyframes_cache, storage_dir
+
+
+APPLICATION_CACHE_SESSION_KEYS = (
+    "fonts_cache",
+    "video_files_cache",
+    "songs_cache",
+    "ffmpeg_engine_report",
+)
+
+
+def _clear_streamlit_caches():
+    st.cache_data.clear()
+    cache_resource = getattr(st, "cache_resource", None)
+    if cache_resource is not None:
+        cache_resource.clear()
+
+
+def clear_application_cache(
+    session_state=None,
+    clear_streamlit_cache=None,
+    clear_llm_cache=None,
+    clear_keyframes_cache=None,
+    reset_ffmpeg_detection=None,
+):
+    """Clear runtime caches that can keep stale UI/model/media state."""
+    state = st.session_state if session_state is None else session_state
+    for key in APPLICATION_CACHE_SESSION_KEYS:
+        state.pop(key, None)
+
+    operations = (
+        ("streamlit", clear_streamlit_cache or _clear_streamlit_caches),
+        ("llm", clear_llm_cache or UnifiedLLMService.clear_cache),
+        ("keyframes", clear_keyframes_cache or globals()["clear_keyframes_cache"]),
+        ("ffmpeg", reset_ffmpeg_detection or ffmpeg_utils.reset_hwaccel_detection),
+    )
+
+    errors = []
+    for name, operation in operations:
+        try:
+            operation()
+        except Exception as exc:
+            errors.append(f"{name}: {exc}")
+            logger.error(f"Failed to clear {name} cache: {exc}")
+
+    return errors
 
 
 def clear_directory(dir_path, tr):
@@ -188,7 +234,7 @@ def render_ffmpeg_engine_settings(tr):
 def render_system_panel(tr):
     """渲染系统设置面板"""
     with st.expander(tr("System settings"), expanded=False):
-        col1, col2, col3 = st.columns(3)
+        col1, col2, col3, col4 = st.columns(4)
                 
         with col1:
             if st.button(tr("Clear frames"), use_container_width=True):
@@ -202,4 +248,12 @@ def render_system_panel(tr):
             if st.button(tr("Clear tasks"), use_container_width=True):
                 clear_directory(os.path.join(storage_dir(), "tasks"), tr)
 
+        with col4:
+            if st.button(tr("Clear Cache"), use_container_width=True):
+                errors = clear_application_cache()
+                if errors:
+                    st.error(f"{tr('Failed to clear cache')}: {'; '.join(errors)}")
+                else:
+                    st.success(tr("Cache cleared"))
+
         render_ffmpeg_engine_settings(tr)

webui/components/test_system_settings_unittest.py

@@ -0,0 +1,46 @@
+import unittest
+
+from webui.components.system_settings import clear_application_cache
+
+
+class SystemSettingsCacheTests(unittest.TestCase):
+    def test_clear_application_cache_clears_runtime_caches(self):
+        session_state = {
+            "fonts_cache": ["SimHei"],
+            "video_files_cache": ["a.mp4"],
+            "songs_cache": ["bgm.mp3"],
+            "ffmpeg_engine_report": {"ffmpeg_available": True},
+            "unrelated": "keep",
+        }
+        calls = []
+
+        errors = clear_application_cache(
+            session_state=session_state,
+            clear_streamlit_cache=lambda: calls.append("streamlit"),
+            clear_llm_cache=lambda: calls.append("llm"),
+            clear_keyframes_cache=lambda: calls.append("keyframes"),
+            reset_ffmpeg_detection=lambda: calls.append("ffmpeg"),
+        )
+
+        self.assertEqual([], errors)
+        self.assertEqual(["streamlit", "llm", "keyframes", "ffmpeg"], calls)
+        self.assertEqual({"unrelated": "keep"}, session_state)
+
+    def test_clear_application_cache_reports_clear_failures(self):
+        def fail():
+            raise RuntimeError("boom")
+
+        errors = clear_application_cache(
+            session_state={},
+            clear_streamlit_cache=fail,
+            clear_llm_cache=lambda: None,
+            clear_keyframes_cache=lambda: None,
+            reset_ffmpeg_detection=lambda: None,
+        )
+
+        self.assertEqual(1, len(errors))
+        self.assertIn("boom", errors[0])
+
+
+if __name__ == "__main__":
+    unittest.main()